Hinkley HCP Environmental Assessment

U.S. Fish and Wildlife Service
2017-08-17
Pacific Gas and Electric Company (PG&E)

Hinkley HCP Environmental Assessment

 

 

 

Prepared by

U.S. Fish and Wildlife Service

 

 

August 2017

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Contents

Section                                                                                                                                                                                        Page

 

Acronyms and Abbreviations............................................................................................................ vii

1                     Introduction/Purpose and Need.......................................................................................... 1-1

1.1               Background............................................................................................................. 1-1

1.2               Purpose and Need of the Federal Action................................................................... 1-2

1.3               Decisions to be Made.............................................................................................. 1-3

1.4               Public Involvement.................................................................................................. 1-3

2                     Proposed Action and Alternatives........................................................................................ 2-1

2.1               Proposed Action...................................................................................................... 2-1

2.2               Description of Alternatives....................................................................................... 2-2

2.2.1          Alternative 1: No Action............................................................................... 2-2

2.2.2          Alternative 2: PG&E’s Proposed Hinkley Groundwater Remedy HCP............... 2-8

2.3               Alternatives Considered but not Carried Forward.................................................... 2-27

2.3.1          Other Remediation Approaches Alternative................................................ 2-27

2.3.2          Phased Implementation Alternative............................................................ 2-27

2.3.3          Incidental Take Permit Term Alternative..................................................... 2-28

2.3.4          Additional Species Alternative.................................................................... 2-28

3                     Approach to the Analysis..................................................................................................... 3-1

3.1               Issues and Concerns................................................................................................. 3-1

3.1.1          Impacts Discussed in this EA......................................................................... 3-1

3.1.2          Impacts Not Discussed with Rationale........................................................... 3-2

3.2               Cumulative Impacts................................................................................................. 3-6

4                     Biological Resources............................................................................................................ 4-1

4.1               Regulatory Setting................................................................................................... 4-1

4.1.1          Federal Endangered Species Act................................................................... 4-1

4.1.2          Migratory Bird Treaty Act............................................................................. 4-2

4.1.3          Bald and Golden Eagle Protection Act........................................................... 4-2

4.1.4          California Endangered Species Act................................................................ 4-2

4.1.5          California Fish and Game Code..................................................................... 4-2

4.2               Affected Environment.............................................................................................. 4-3

4.2.1          Background................................................................................................. 4-3

4.2.2          Land Cover Types......................................................................................... 4-3

4.2.3          Wildlife....................................................................................................... 4-3

4.3               Environmental Consequences.................................................................................. 4-5

4.3.1          Alternative 1: No Action............................................................................... 4-6

4.3.2          Alternative 2: PG&E’s Proposed Hinkley Groundwater Remedy HCP............. 4-15

4.3.3          Cumulative Effects..................................................................................... 4-27

5                     Water Quality..................................................................................................................... 5-1

5.1               Regulatory Setting................................................................................................... 5-1

5.2               Affected Environment.............................................................................................. 5-2

5.2.1          Total Dissolved Solids................................................................................... 5-3

5.2.2          Uranium and Other Radionuclides................................................................ 5-3

5.2.3          Nitrate........................................................................................................ 5-4

5.2.4          Arsenic........................................................................................................ 5-5

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CONTENTS

Section                                                                                                                                                                                        Page

5.2.5          Iron............................................................................................................ 5-5

5.2.6          Manganese................................................................................................. 5-6

5.3               Environmental Consequences.................................................................................. 5-6

5.3.1          Alternative 1: No Action............................................................................... 5-6

5.3.2          Alternative 2: PG&E’s Proposed Hinkley Groundwater Remedy HCP............... 5-9

5.3.3          Cumulative Effects.................................................................................... 5-11

6                     Cultural Resources.............................................................................................................. 6-1

6.1               Regulatory Setting................................................................................................... 6-1

6.2               Affected Environment............................................................................................. 6-1

6.3               Environmental Consequences.................................................................................. 6-2

6.3.1          Alternative 1: No Action............................................................................... 6-2

6.3.2          Alternative 2: PG&E’s Proposed Hinkley Groundwater Remedy HCP.............. 6-3

6.3.3          Cumulative Effects...................................................................................... 6-4

7                     Environmental Justice......................................................................................................... 7-1

7.1               Regulatory Setting................................................................................................... 7-1

7.2               Affected Environment............................................................................................. 7-1

7.3               Environmental Consequences.................................................................................. 7-2

7.3.1          Alternative 1: No Action............................................................................... 7-2

7.3.2          Alternative 2: PG&E’s Proposed Hinkley Groundwater Remedy HCP.............. 7-2

7.3.3          Cumulative Effects...................................................................................... 7-2

8                     List of Preparers................................................................................................................. 8-1

8.1               U.S. Fish and Wildlife Service................................................................................... 8-1

8.2               CH2M HILL Engineers, Inc........................................................................................ 8-1

9                     References......................................................................................................................... 9-1

 

 

 

Appendix

 

A             Nesting Birds: Species-Specific Buffers for PG&E Activities

 

Tables

2-1               Remediation Facilities to be Developed, Operated, and Maintained under Alternative 1

(No Action)......................................................................................................................... 2-2

2-2               Remediation Facilities to be Developed, Operated, and Maintained under Alternative 2

(Hinkley HCP).................................................................................................................... 2-10

2-3               Emergency Facility Repairs Anticipated under Alternative 2................................................. 2-14

4-1          Temporary and Permanent Impacts (in acres) to Plan Area Desert Tortoise Suitable Habitat,

by Covered Activity and Remediation Phase....................................................................... 4-19

5-1               Maximum Contaminant Levels............................................................................................. 5-2

5-2               Groundwater Quality Objectives for Groundwater Basins in the Lahontan Region................... 5-2

 

 

 

 

 

 

 

 

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CONTENTS

 

Figures

1-1          Project Location

2-1               Plan Area

2-2               Monitoring Wells

2-3               Treatment Areas

2-4               In Situ and Ex Situ Treatment

2-5               Geographic Region Within the Plan Area Where Desert Tortoise Clearance Surveys May Be Performed by Biological Monitors Rather Than by Authorized Biologists

7-1          Minority Percentage by Census Block Group 7-2                Poverty Percentage by Census Tract

 

Acronyms and Abbreviations

°F                                        degrees Fahrenheit

ACEC                                 Areas of Critical Environmental Concern

AT                                       agricultural treatment

ATSDR                               U.S. Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry

ATU                                   Agricultural Treatment Unit

BGEPA                              Bald and Golden Eagle Protection Act

bgs                                     below ground surface

BLM                                   Bureau of Land Management

Caltrans                            California Department of Transportation

CAO                                   Cleanup and Abatement Order

CBG                                   Census Block Group

CDFW                                California Department of Fish and Wildlife

CEQ                                    Council on Environmental Quality

CEQA                                 California Environmental Quality Act

CESA                                  California Endangered Species Act

CFR                                    Code of Federal Regulations

CH2M                                CH2M HILL Engineers, Inc.

CHU                                   Critical Habitat Unit

CM                                     Conservation Measure

CNPS                                 California Native Plant Society

Cr(III)                                trivalent chromium

Cr(VI)                                hexavalent chromium

DRECP                               Desert Renewable Energy Conservation Plan

EA                                       Hinkley HCP Environmental Assessment

EO                                      Executive Order

EPA                                    U.S. Environmental Protection Agency

ESA                                    Endangered Species Act

FEIR                                   Final Environmental Impact Report

GHG                                  greenhouse gas

HCP                                    Habitat Conservation Plan

IPMP                                 Integrated Pest Management Plan

IRZ                                      in situ reactive zone

 

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ACRONYMS AND ABBREVIATIONS

 

ITP                                      Incidental Take Permit

KPC                                    Key Population Center

MBTA                                Migratory Bird Treaty Act

MCL                                   maximum contaminant level

MDAQMD                       Mojave Desert Air Quality Management District milligrams per liter                            (mg/L)

MGSWG                          Mohave Ground Squirrel Work Group

MM                                   mitigation measure

NA                                      none adopted

NEPA                                 National Environmental Policy Act

NFWF                                National Fish and Wildlife Foundation

NHPA                                National Historic Preservation Act

NMFS                                National Marine Fisheries Service

NOA                                  Notice of Availability

NRHP                                National Register of Historic Places

O&M                                 operation and maintenance

OU                                     operable unit

pCi/L                                  picocurie(s) per liter

PG&E                                Pacific Gas and Electric Company

ppb                                    parts per billion

RMP                                  Raven Management Plan

SDWA                               Safe Drinking Water Act

SR                                       State Route

SWRCB                             California State Water Resources Control Board

TDS                                    total dissolved solids

the Service                      U.S. Fish and Wildlife Service

U.S.C.                                United States Code

USFWS                             U.S. Fish and Wildlife Service

USGS                                 U.S. Geological Survey

Water Board                  California Regional Water Quality Control Board, Lahontan Region WDR                                            waste discharge requirement

WMRU                             West Mojave Recovery Unit

 

 

 

 

 

 

VIII                                                                                                                                                                               EN1010161105SAC

 

CHAPTER 1

Introduction/Purpose and Need

The U.S. Fish and Wildlife Service (Service or USFWS) is considering a permit application by Pacific Gas and Electric Company (PG&E) for incidental take of desert tortoise (Gopherus agassizii) and Mohave ground squirrel (Xerospermophilus mohavensis). Incidental take may occur from groundwater remediation activities that the California Regional Water Quality Control Board, Lahontan Region (Water Board) is requiring of PG&E in and around Hinkley, California. The Endangered Species Act (ESA) and its implementing regulations prohibit the take of fish or wildlife species that are federally listed as threatened or endangered without prior approval.1 ESA Section 10(a)(1)(B) and its implementing regulations allow the Service to issue a permit – a federal Incidental Take Permit (ITP) – if an applicant

prepares a habitat conservation plan and meets the issuance criteria described in Section 1.3 below. The Service and PG&E have determined that the Hinkley groundwater remediation activities may result in the incidental take of the federally listed (threatened) desert tortoise. Incidental take is defined by the ESA as “take that is incidental to, and not the purpose of, the carrying out of an otherwise lawful activity.” Based on this determination, PG&E prepared the Hinkley Groundwater Remediation Project Habitat Conservation Plan (HCP) and submitted an ITP application to the Service.

This Hinkley HCP Environmental Assessment (EA) evaluates the environmental impacts that have the potential to occur as a result of issuing the ITP and implementing the HCP. This EA has been prepared in accordance with the National Environmental Policy Act (NEPA), which provides an interdisciplinary framework for federal agencies to evaluate the environmental consequences of proposed actions over which they have discretionary authority by authorizing, funding, or carrying out the actions. The Service is the NEPA Lead Agency.

1.1      Background

PG&E’s natural gas distribution system includes more than 40,000 miles of distribution pipelines and more than 6,000 miles of transmission pipelines, collectively providing service to approximately

4.2 million customers from Bakersfield, California, to the Oregon border. Essential to the system are eight gas compressor stations that receive, store, and move natural gas through PG&E’s pipelines. The Hinkley Compressor Station is located in the community of Hinkley in San Bernardino County, approximately 4 miles west of Barstow along State Route (SR) 58 and north of the Mojave River (Figure 1-1).

One of the first compressor stations on the PG&E gas transmission lines, the Hinkley station began operating in the early 1950s. An additive containing hexavalent chromium (Cr[VI]) was used at this facility to prevent rust in cooling towers. Consistent with industry practices of the time, cooling water containing Cr(VI) was disposed of in unlined ponds adjacent to the compressor station. Over time, the discharged cooling water containing Cr(VI) mixed with the groundwater beneath the compressor site. Cr(VI) is now considered carcinogenic to humans. While the Hinkley compressor station is still in service, the use of the additive Cr(VI) has long since been discontinued.2

Using an array of monitoring wells, PG&E conducts groundwater monitoring and reporting to track and characterize groundwater beneath the Hinkley Valley. The groundwater plume contaminated by Cr(VI) is

 
   

1  The regulatory definition of “take” under the ESA is, “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct.” USFWS regulations, 50 Code of Federal Regulations (CFR) 17.3, further define the term “harm” to mean “…an act that kills or injures a federally listed fish or wildlife species, including significant habitat modification or degradation where it kills or injures such species by significantly impairing essential behavioral patterns, including breeding, feeding, or sheltering.”

2  PG&E stopped discharging Cr(VI) to unlined ponds in 1964. Cooling tower water, using a different corrosion inhibitor, continued to be discharged to unlined ponds from 1966 to 1972. In 1972, PG&E lined the Hinkley discharge ponds.

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CHAPTER 1 – INTRODUCTION/PURPOSE AND NEED

 

moving in a northerly direction, away from the Hinkley Compressor Station and may have moved towards the Harper Dry Lake Valley about 8 miles away. “Contamination” currently refers to those areas where groundwater samples exceed the interim background concentration of 3.1 parts per billion (ppb) of Cr(VI) or 3.2 ppb of total chromium attributable to the PG&E release. PG&E also delineates the extent of Cr(VI) greater than 10 ppb and total chromium of greater than 50 ppb. HCP Section 2.1.1 provides additional information on the extent of groundwater contamination.

PG&E has remediated Cr(VI) contaminated groundwater at the Hinkley project site since 1991. The goals of remediation are to contain the Cr(VI) plume and remove Cr(VI) from groundwater. To remove Cr(VI) from groundwater, it is reduced from the carcinogenic, soluble, and mobile Cr(VI) to the less toxic and less mobile trivalent chromium (Cr[III]). Primary remediation approaches include the following:

  • Freshwater Injection: Clean freshwater is injected within the aquifer along the plume’s leading margin to prevent or slow the spread of contamination by creating a hydraulic barrier. Groundwater extracted for agricultural treatment (see below) within the plume may also prevent or slow the spread of the contamination plume.
  • Agricultural Treatment: Extracted Cr(VI) groundwater is used to irrigate forage crops for livestock. During irrigation, Cr(VI) in the extracted groundwater is converted to Cr(III) by contact with organic matter as it infiltrates through the soil.
  • In Situ Treatment: Carbon substances (primarily ethanol) are injected or mixed into the groundwater aquifer to stimulate microbial activity, which creates a reducing environment that converts Cr(VI) into Cr(III).

The Water Board adopted a Cleanup and Abatement Order (CAO) in 2008, which required sitewide interim remediation of the contaminated groundwater. The Water Board also adopted waste discharge requirements for various projects implementing agricultural treatment, in situ treatment, and freshwater injection, before and after the 2008 CAO was adopted.

To consolidate multiple existing orders and to apply remedial timeframes, on November 4, 2015, the Water Board adopted a new CAO (No. R6V-2015-0068) directing PG&E to remediate contaminated groundwater at Hinkley. The CAO supersedes several previous Water Board orders and provides direction to define and characterize the contaminated groundwater plume. The new CAO also clarifies groundwater monitoring and reporting actions. Previous Water Board orders directing PG&E to conduct freshwater injection, agricultural treatment, and in situ treatment remediation activities remain active and have been revised subsequent to the 2015 CAO.

Current and proposed remediation techniques, consistent with the new CAO, are described in Chapter 2.

1.2                             Purpose and Need of the Federal Action

The purpose for the proposed federal action is to:

  • Protect and conserve the desert tortoise and the Mohave ground squirrel, and the habitats and ecosystems on which they depend within the remediation project area
  • Ensure their long-term survival in the permit area
    • Allow PG&E to implement its required groundwater remediation activities in the Hinkley area in compliance with Section 10 of the ESA

The proposed action is needed in response to PG&E’s application for an ITP to implement its required groundwater remediation activities because otherwise lawful groundwater remediation activities by

 

 

 

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CHAPTER 1 – INTRODUCTION/PURPOSE AND NEED

 

PG&E could result in take of federally listed species, and species that are currently unlisted but that could become listed in the future.

1.3                             Decisions to be Made

The Service has regulatory jurisdiction over the federally listed species proposed to be covered by the ITP. The Service will decide whether or not to issue an incidental take permit for the federally listed species that are under their jurisdiction and the unlisted covered species that would come under their jurisdiction if they were listed (Section 2.2.2.2, Covered Species).

Under Section 10 of the ESA, the Service may issue an ITP if an applicant prepares a conservation plan. Section 3 of the ESA defines “conservation” as using all methods and procedures necessary to bring an endangered or threatened species to the point at which measures provided in the ESA are no longer necessary (i.e., recovery). Thus, a conservation plan must contribute to the recovery of listed species that are covered in the ITP. In addition, the conservation plan must specify the following:

  • Impact that will likely result from such taking
    • Steps the applicant will take to minimize and mitigate such impacts, and the funding that will be available to implement such steps
    • Alternative actions to such taking the applicant considered and the reasons why such alternatives are not being utilized
    • Other measures that the Secretary of the Interior may require as being necessary or appropriate for purposes of the conservation plan

An ITP may be granted if the permit application and conservation plan demonstrate the following:

  • The taking would be incidental to the implementation of otherwise lawful activities
    • The applicant will, to the maximum extent practicable, minimize and mitigate the impacts of the such taking
    • The applicant will ensure that adequate funding for the HCP and procedures to handle changed circumstances will be provided
    • The taking will not appreciably reduce the likelihood of survival and recovery of the species in the wild
    • The applicant will ensure that other measures that the Service may require as being necessary or appropriate will be provided
    • The Service has received such other assurance as may be required that the HCP will be implemented

In addition to its decision making under the ESA, the Service will take an action under the NEPA based on the analysis contained in this EA. Issuance of an ITP is a federal action subject to the NEPA, and it is anticipated that the Service will issue a Finding of No Significant Impact concurrent with its action on the ITP.

1.4                             Public Involvement

In accordance with the Service’s Outreach Plan, a Notice of Availability (NOA) of the Service’s proposed action was issued, addressing both the Draft HCP and the Draft EA. The NOA was distributed to agencies, officials, and individuals on a distribution list compiled by the Service and PG&E. The NOA also was published in the Federal Register and in the Barstow Desert Dispatch. Copies of the Draft HCP and Draft EA have been made available for review online, and at the following locations in the local area – the Barstow Library, PG&E’s Outreach Office, and at the Independent Review Panel Manager’s office.

 

CHAPTER 2

Proposed Action and Alternatives

This chapter describes the Service’s proposed action. One alternative would be the No Action Alternative, where the Service would not issue a permit, while the only action alternative (implementation of the HCP) would require an ITP. This chapter also includes a summary of alternatives considered but not carried forward for detailed analysis in this EA.

2.1      Proposed Action

The proposed action is the issuance of an ITP by the Service to PG&E for the incidental take of listed species from covered activities, including the avoidance, minimization, and mitigation of impacts to covered species within the proposed plan area for 50 years. The plan area is approximately 30,000 acres in size, and includes all areas within which PG&E is proposing to conduct groundwater remediation activities (Figure 2-1).

The approximately 30,000-acre remediation project area is common to all alternatives, and represents the surface area above the projected maximum spatial extent of the Cr(VI) groundwater plume. The project area also defines the maximum spatial extent of surface areas within which PG&E may implement groundwater remediation activities, and the maximum spatial extent of potential groundwater effects such as drawdown or accumulation of remediation byproducts.

Three operable units (OUs) have been defined within the remediation project area to represent areas in which different types of remedial activities would occur (Figure 2-1). The OUs are defined in relation to the various groundwater contamination levels represented by the plume area.

  • OU1 extends northward approximately 1.5 miles from Highcrest Road to approximately Ashwood Road. OU1 is bounded on the west roughly by Serra Road and extends east of Summerset Road by approximately 0.25 mile. This 1,378 acre OU contains the Hinkley Compressor Station and generally overlays the contour of the 50 ppb Cr(VI) plume. The existing in situ reactive zone (IRZ) (described later in this chapter) is located in OU1. Two existing Agricultural Treatment Units (ATUs) are in OU1, and one existing ATU is located in both OU1 and OU2, with most of its acreage in OU1.
  • OU2 is 1,715 acres and adjacent to and north of OU1, extending northward from Ashwood Road approximately 1.75 miles to Salinas Road. OU2 is bounded to the west by Serra Road and extends east of Summerset Road by approximately 0.25 mile. OU2 contains most of the contour of the

10 ppb Cr(VI) plume (that is outside the 50 ppb contour). Six existing ATUs are in OU2.3

  • OU3 circumscribes OU1 and OU2 and is the surface area that fully contains the known extent of the

3.1 ppb Cr(VI) contour.4 OU3 is sufficiently large to include areas where the future plume may be detected and where future remedial actions, monitoring activities, and direct and indirect effects of remedial actions may occur in the future. The current OU3 area encompasses approximately 26,825 acres. OU3 is bounded to the south by the north bank of the Mojave River, to the north by a location approximately 2 miles north of BN Ranch Road, to the west by Valley Wells Road, and to the east by Mount General about 1 mile east of Lenwood Road. The northern boundary of OU3 was set at a location approximately 1 mile northward of the northern-most PG&E groundwater monitoring well.

 
   

3  ATUs are areas used for active remediation where soil microbial action in the presence of iron reduces dissolved Cr(VI) to solid Cr(III). This process is described in greater detail under the discussion of agricultural treatment, later in this chapter.

4  An original background study completed by PG&E in 2006 reported a range of 0.2 to 2.69 ppb Cr(VI) (mean = 1.19 ppb) among 48 sampled wells; the calculated 95 percent upper tolerance limit was 3.09 ppb. The Water Board Executive Officer amended CAO No. R6V-2008-0002 on November 12, 2008, to set 3.1 ppb as the maximum background level of Cr(VI) to guide remediation.

 

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This buffer was established to anticipate where the plume may be detected in the future (due to migration and/or additional detection), where monitoring activities may be implemented, and areas of groundwater drawdown effects.

2.2                             Description of Alternatives

2.2.1                       Alternative 1: No Action

Alternative 1 is based on PG&E’s implementation of groundwater remediation activities in areas where take of listed species would be avoided; we would not issue an ITP. Under Alternative 1, PG&E would implement various types of groundwater remediation activities, consistent with current laws and regulations, in a manner that does not result in take of federally listed species. The timeframe for Alternative 1 is 50 years, to match the proposed timeframe of the action alternatives described later in this chapter.

2.2.1.1         Monitoring and Remediation Activities

Monitoring and remediation activities would occur at facilities that are currently developed and at new locations with prior authorizations. Outside of these previously authorized areas, development of new facilities would occur only in previously disturbed areas or barren areas that do not provide suitable habitat for federally listed species.

Full development of the remediation program would not occur, as many of the new facilities (including ATUs) must be constructed within areas of suitable habitat. PG&E is likely to experience delays in meeting its regulatory obligations without the ability to develop new facilities in areas of suitable habitat. Groundwater monitoring and remediation activities to be implemented under Alternative 1 are summarized in Table 2-1, and are described in detail in the following paragraphs.

 

Table 2-1. Remediation Facilities to be Developed, Operated, and Maintained under Alternative 1 (No Action)

 


Covered Activity                                 Existinga                                Future                                         Total

Groundwater Monitoring

 

Groundwater Monitoring Wells (units)

756

20

776

Investigative Borings (sites)

Not Applicable

2

2

Domestic Supply Wells (units)

Unknown

Remove 10 to 20 per year

Undefined

Freshwater Injection System

 

 

 

Extraction Wells (units)

4

0

4

Injection Wells (units)

7

0

7

Pipelines/Trenches (feet)

39,000

0

39,000

Agricultural Treatment

 

 

 

ATUs (field acres)

306

0

306

Extraction Wells (units)

59

30

89

Pipelines/Trenches (feet)

43,565

0

43,565

In Situ Treatment

 

 

 

Extraction Wells (units)

25

0

25

Injection Wells (units)

100

5

105

Well Vaults/Enclosures (units)

125

0

125

Ethanol Dosing Facilities (units)

2

0

2

Pipelines/Trenches (feet)

30,566

0

30,566

 

 

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  Table 2-1. Remediation Facilities to be Developed, Operated, and Maintained under Alternative 1 (No Action)               


Covered Activity                                 Existinga                                Future                                         Total

Other

 

Access Roads (miles)

54

0.5

54.5

Structure Demolitions (units)

Not Applicable

100

100

a Existing conditions updated through December 31, 2016.

 

Groundwater Monitoring

As of December 31, 2016, 756 groundwater monitoring wells and an unknown number of domestic water supply wells were installed or already located in the remediation project area (Table 2-1). During the fourth quarter of 2016, PG&E conducted groundwater sampling at 424 groundwater monitoring wells and at 50 domestic water supply wells to track the spatial and temporal configuration of Cr(VI) and other analytes in the groundwater of the remediation project area (Figure 2-2). The number of wells in the project area and the subset of wells that is sampled during a given interval varies over time, reflecting well installations and removals (decommissioning), the operating condition of wells when they are scheduled for sampling and the sampling frequency decision trees outlined in the CAO. The total number of sampled wells (groundwater monitoring and domestic water supply wells) has decreased through time, reflecting PG&E’s conditionally approved systematic decommissioning of inactive former domestic wells and generally stable or decreasing Cr(VI) groundwater trends over time.5

Monitoring well locations are distributed densely in OU1 and OU2 to track higher groundwater concentrations of Cr(VI). Groundwater monitoring well locations in OU3 are more spread out, and detect and delineate the lower-concentration Cr(VI) in groundwater and areas with no currently detectable Cr(VI) contamination. Many groundwater monitoring wells are installed near and in the designated IRZ to detect the presence, concentration, and movement of in situ treatment by-products including iron, arsenic, and manganese (termed “sentry” wells when used for this purpose).

Construction: Groundwater monitoring well installation would take place within areas that have been previously disturbed (e.g., roadsides) to avoid disturbance to vegetation. Prior to well installation (whether vegetation clearing is necessary or not), qualified biologists will inspect the installation location for sensitive resources. If sensitive resources are present, the biologist will document the occurrence(s) and the well location would be moved to avoid these resources. If necessary, vegetation would be cleared by hand to allow a truck-mounted drill rig access to the well site. Well holes at Hinkley are typically drilled using hollow-stem auger and sonic drilling methods (most boreholes are drilled through alluvial material); a mud rotary or air rotary rig is required to drill through bedrock. Soil from an investigative boring would be described in the field according to the Unified Soil Classification System, by or under the direct supervision of a California Professional Geologist, and presented on a borehole log. If, following this investigative boring process, the geology is determined to be suitable, a groundwater monitoring well location would be established. In approximately 10 percent of cases, investigative boring proves the location to be unsuitable. In these cases, the borehole would be grouted and backfilled. The disturbance area (construction zone) associated with each unproductive investigative boring location is 2,500 square feet (50- by 50-foot work area).

For approximately 90 percent of investigative boring locations, the geology proves to be suitable to install a groundwater monitoring well. In these cases, a well casing would be driven/drilled into the borehole by a truck-mounted rig to the desired depth, the well capped, and a concrete pad formed and

 
   

5  On March 6, 2013, PG&E submitted to the Water Board its Plan for Removal of Inactive Domestic Wells from the Domestic Well Sampling Program, Hinkley, California, which outlined a plan for removing and managing supply wells. On PG&E-owned properties, PG&E may decommission existing domestic water supply wells if the well meets certain criteria approved by the Water Board. The Water Board has approved two specific PG&E requests to abandon inactive wells in letters dated April 17, 2017 and June 30, 2017.

 

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CHAPTER 2 – PROPOSED ACTION AND ALTERNATIVES

 

poured around the well for structural stability. Soil removed during drilling is either transported off site for disposal at an appropriately permitted facility or placed at an ATU. Each well site requires a construction zone of up to 10,000 square feet (100- by 100-foot work area) for installation.

Groundwater monitoring wells are typically set at ground level and occupy less than 10 square feet (may or may not be set within a 3-foot by 3-foot concrete foundation pad) when finished. Following installation, groundwater monitoring wells do not routinely require maintenance because they are passively operated and are not generally powered with pumps.

Operations and Maintenance: Under Alternative 1, PG&E would continue to operate and maintain the existing array of groundwater monitoring wells and those constructed in nonhabitat areas during remediation activities. During groundwater monitoring well operation, a crew member drives to a well site, removes the well cap, and records a static water level. Well casings are purged prior to collecting a water sample, and purged water is containerized, transported, and disposed of at in situ treatment holding tanks (further described in subsection In Situ Treatment) or is applied to ATUs in OU1 or OU2. Purge water from domestic water supply wells is typically discharged to the ground at the well site or, in some cases, is containerized in the same manner as groundwater monitoring well purge water and disposed of at the two locations noted above. Wells may be monitored biennially, annually, semi- annually, or quarterly. Wells are typically monitored more frequently when they are newly installed.

Decommissioning: Groundwater monitoring wells and domestic water supply wells used for groundwater monitoring may be decommissioned if they are no longer needed for testing or remediation activities, or if they become nonoperational and cannot be returned to service. A truck- mounted drill rig is used to remove debris in the well. In accordance with local permits, the well casing is filled with gravel or a cement slurry is pumped inside the well casing to permanently seal it. The well casing is cut off approximately 5 feet below grade, and a concrete cap is placed over the casing. The area is backfilled with the soil that was excavated to expose the well pipe to approximately 5 feet below grade. Well decommissioning, like well installation, requires a work area of approximately 10,000 square feet for each well. Existing access routes are used during decommissioning, and no new access roads are required for this task. Well decommissioning requires similar equipment and vehicles as those used for well installation. Work areas for decommissioning wells would be the same areas used during well installations. At the completion of all remediation activities, all groundwater monitoring wells in service would be decommissioned.

Freshwater Injection System

Freshwater injection system operation or hydraulic control, limits the movement of groundwater contamination by injecting fresh water outside the leading edges of a groundwater plume. Injected freshwater also flushes the plume toward remedial extraction wells.

As of December 31, 2016, PG&E operated and maintained four freshwater extraction wells and seven freshwater injection wells to accomplish freshwater injection (Figure 2-3). The freshwater extraction wells are located south of the Hinkley Compressor Station in OU3 and are not exposed to Cr(VI) contamination. Water pumped from these extraction wells is conveyed through a common underground pipeline to the western boundary of OU1 and OU2 and injected to the groundwater to create a hydraulic mound to prevent the further spread of contaminated groundwater. Approximately 39,000 linear feet of underground water pipelines are associated with existing freshwater injection system facilities

(Table 2-1). As remediation progresses, the need for continued freshwater injection will be evaluated.

Construction: No additional freshwater injection system facilities (i.e., extraction wells, injection wells, and conveyance pipeline) would be constructed under Alternative 1.

Operations and Maintenance: Existing freshwater injection system facilities may be operated and maintained during the 50-year remediation period. Freshwater extraction and injection wells are inspected daily, and pumps are adjusted as needed to maintain optimal extraction and injection flow

 

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rates for hydraulic control. Freshwater injection system wells may be back-flushed periodically to maintain flow rates. Back-flush water on injection wells is collected and disposed. For backwashing, water is pumped from the wells and collected in an adjacent tank. When backwashing is done, the water is run through bag filters and then injected back into the injection wells. No chemicals are used in the backwashing process. Freshwater injection wells may also be chemically (with antifouling agents) or mechanically (i.e., scrubbed) cleaned to maintain function.6 Manual rehabilitation includes brushing and jetting the inside of the well. Chemical rehabilitation involves pouring treatment chemicals into the well and letting the chemicals remain in the well for a period of time until the pH stabilizes which is usually followed by mechanical scrubbing to remove built up solids. When chemical or mechanical rehabilitation is conducted, water and solids are removed from the well and placed into drums once the pH has stabilized. The solids are allowed to settle out in the drums and the water is decanted from the drums and injected back into the ground. The solids are transported offsite for disposal at an appropriate facility. Water elevations and water chemistry samples are recorded and collected from freshwater injection wells as described above under groundwater monitoring.

Underground pipelines are only anticipated to require maintenance in the event of a catastrophic or unanticipated failure (Emergency Repairs paragraph, later in this section). For planning purposes, PG&E estimates that up to 10 percent of plume containment conveyance pipelines (approximately 3,900 linear feet) may require repair during the 50-year period. Repair of a failed or damaged pipeline requires disturbance of a 50-foot-wide corridor parallel with the alignment of the pipe to allow space for equipment (typically an excavator) to excavate and uncover the damaged/failed section of pipe.

Following repair, stockpiled soil is replaced in the excavated corridor.

Decommissioning: Freshwater extraction and freshwater injection wells would be decommissioned similar to the process described for groundwater monitoring wells. Buried conveyance pipelines would be left in place and not removed at the completion of remediation activities.

Agricultural Treatment

Agricultural treatment (AT) involves the extraction of Cr(VI) contaminated groundwater and its application to ATUs where soil microbial action in the presence of iron reduces dissolved Cr(VI) to solid Cr(III) and deposits it at the surface. Cr(III) is a trace element essential in human diets (ATSDR, 2016).

Agricultural treatment has been shown by PG&E to be 95 percent effective at removing Cr(VI) from extracted groundwater (Water Board, 2014).

Extracted groundwater is conveyed to ATUs via underground pipelines and applied via drag-drip irrigation systems to avoid misting or over-spraying. Regulatory restrictions state that surface ponding of groundwater applied to ATUs may not persist for more than 24 hours (Water Board, 2014). The configuration of the drag-drip irrigation system selected for each site depends on the size and shape of the parcel. The shoots of plants do not accomplish the reduction process. Instead, the reduction of Cr(VI) to Cr(III) is accomplished in the plant root zone by microbes in the soil.7

As of December 31, 2016, eight ATUs totaling approximately 306 acres were operational in the remediation project area (Table 2-1). The Desert View Dairy ATU is a former dairy located in OU2. Seven other ATUs are in the project area. The Community East ATU, Fairview ATU, and most of the Ranch ATU are located in OU1. Four additional ATUs (North Gorman, South Gorman, Cottrell, and Yang) and a portion of the Ranch ATU are located in OU2 (Figure 2-3).

Current ATU crops typically include alfalfa, Bermuda grass, Italian ryegrass, Sudan grass, winter barley and winter wheat (Arcadis, 2014a) that are grown year-round. As of December 31, 2016, PG&E operated 59 AT extraction wells in OU1 and OU2 (Figure 2-3), with extracted water conveyed to ATUs though

 
   

6  This includes all well types (i.e., monitoring, extraction, injection).

7  Reduction as used here refers to a chemical reaction that adds three electrons (reduces) to Cr(VI) and converts it to Cr(III).

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approximately 43,565 linear feet of underground conveyance pipelines (Table 2-1). ATUs are fenced to exclude desert tortoise from accessing irrigated fields. The specifications for desert tortoise exclusion fencing follow the current direction established by the Service. ATUs are harvested by cutting, drying, and baling their crops. Individual ATUs can be shut down entirely for harvest, or sequentially harvested. Herbicides may be used for weed management during operation of ATUs. Weed management on ATUs is managed pursuant to an Integrated Pest Management Plan (IPMP) (Arcadis, 2014a).8

Construction: Under Alternative 1, no additional ATUs or associated AT facilities would be constructed over the next 50 years.

Operations and Maintenance: Operation and maintenance of existing AT extraction wells and conveyance pipelines would be the same as described above for freshwater injection system wells. Exclusion fences and irrigation/pumping equipment would be inspected regularly and repaired as needed. Underground pipelines are only anticipated to require maintenance in the event of a catastrophic or unanticipated failure (Emergency Repairs paragraph later in this section). Pipeline repairs would occur as described above for freshwater injection system. For planning purposes, PG&E estimates that approximately 4,356 linear feet (10 percent) of conveyance pipeline is expected to require repair over the next 50 years.

Decommissioning: AT wells would be decommissioned as described for groundwater monitoring well decommissioning. AT conveyance pipelines would be left in place. ATUs may be decommissioned upon project completion, or may be left in place for commercial agricultural business. Some extraction wells may be left in place to support irrigation of commercial agriculture.

In Situ Treatment

In situ treatment includes mixing biological and chemical reducing agents (food-grade carbon sources such as ethanol or lactate) with contaminated groundwater to promote microbial reduction of Cr(VI) to Cr(III) within a contaminated aquifer. In situ treatment is currently implemented only in the South and Central areas of OU1 to treat groundwater with the highest levels (generally, greater than 10 ppb) of detected Cr(VI) contamination (Figure 2-4). In situ treatment is accomplished in two ways.

Contaminated groundwater is pumped to the surface using extraction wells, reducing agents are mixed with the extracted groundwater in surface tanks or conveyance pipework and the amended groundwater is re-injected to the aquifer.

An approximately 342-acre IRZ is located within OU1 (Figure 2-4). Existing in situ treatment wells are protected within fenced (chain-link) surface enclosures or within subsurface (at-grade) concrete vaults, typically with only one well located within an enclosure/vault. As of December 31, 2016, PG&E operated and maintained 125 such enclosures (approximately 16 square feet each). Two large ethanol dosing facilities, each about 20,000 square feet, are located within the IRZ. In addition to ethanol holding tanks, these facilities contain mixing tanks, conveyance pipework, and electrical power subpanels. Existing underground pipelines (approximately 30,566 linear feet) move water among these in situ treatment facilities (Table 2-1).

Construction: No additional in situ treatment facilities are proposed for construction under Alternative 1.

Operations and Maintenance: PG&E would continue to operate and maintain existing in situ facilities during the next 50 years. Daily system checks are conducted to inspect equipment and enclosures to ensure that they are in good condition and that pipelines (exposed and buried) are not leaking. System checks include visual inspection of the operating systems and confirmation that the various components are operating correctly. If issues are noted, periodic repairs of the various system components are

 

8  Integrated Pest Management is the coordinated use of pest and environmental information with available control methods to prevent unacceptable levels of damage by the most economical means and with the least possible hazard to people, property, and the environment.

 

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completed. Existing in situ extraction and injection wells may periodically be backwashed to maintain their function. Backwash water is extracted from a well, filtered in the vicinity of the well with a vehicle- mounted filter to remove bacteria, and re-injected back into the well. In situ wells may be periodically rehabilitated using the same process as described previously for freshwater injection system wells.

Living organisms (commonly algal and bacterial film) may coat the inner surface of wells, constricting capacity and increasing surface roughness and friction, thereby decreasing the effective flow capacity and flow rate within an injection well beyond the efficacy of backwashing. In these circumstances, wells may be replaced rather than rehabilitated. The proportion of in situ treatment wells that may require replacement rather than rehabilitation is uncertain but estimated to be 20. Underground pipelines are only anticipated to require maintenance in the event of a catastrophic or unanticipated failure (Emergency Repairs paragraph later in this section). Pipeline repairs would occur as described above for freshwater injection system. For planning purposes, PG&E estimates that approximately 3,056 linear feet (10 percent) of conveyance pipeline are assumed to require repair during the next 50 years.

Decommissioning: Decommissioning of in situ wells following completion of remediation would be as described for decommissioning of groundwater monitoring wells. Conveyance pipelines would be left in place. Removal of enclosures, both surface and at-grade, would be conducted within areas previously disturbed by construction of in situ enclosures.

Other Activities

In addition to groundwater monitoring and continued implementation of the active groundwater remediation approaches described above, PG&E would continue to conduct the following related activities under Alternative 1:

  • Access road construction, use, and maintenance of roads that are responsibility of PG&E
  • Structure demolition
  • Emergency repair

Access Roads PG&E currently uses and maintains about 54 miles of unpaved access roadways in the remediation project area. With an average road width of 10 feet and 3-foot shoulders on each side, access roads occupy a total of about 105 acres of the remediation project area. PG&E also uses dirt or paved roads owned and maintained by San Bernardino County to access remediation facilities. Under Alternative 1, PG&E could construct new access roads to support remediation. Future access roads would likely have the same dimensions as current access roads (i.e., 10-foot road width and 3-foot shoulders on each side). Road construction includes conducting biological surveys in advance of construction to avoid sensitive resources, including species and habitats, hand-removal of vegetation if alignments cannot feasibly avoid vegetated areas, roadbed grading and compaction, and road surfacing with gravel and/or application of a commercially available emulsifier product such as SOILTAC® or DirtGlue to temporarily stabilize the soil for dust control. Existing and new access roads would be used, and would be maintained by grading, compacting, graveling, and abating dust by application of water, lignin (natural, plant-based polymer), and emulsifiers. Roadbeds are kept clear of vegetation to facilitate their regular use, while vegetation may be allowed to restore on shoulder berms. Road grading results in the creation of interspersed soil berms at the shoulders of graded roads that can be 0.5 to 3 feet tall depending on the type and quantify of soil moved by the grading equipment. Roadside berms formed by road grading are left in place.

Structure Demolition PG&E has acquired, and will likely continue to acquire, private properties within the project area as part of its activities. Many of these private properties include surface structures such as houses, outbuildings, and other constructed spaces previously used by property owners, as well as septic systems, domestic wells, driveways, and other ancillary structures. Once purchased, these structures are commonly demolished to prevent onsite vandalism and vagrancy or to facilitate construction of remediation facilities such as wells or ATUs. As of December 31, 2016, PG&E has demolished approximately 210 structures, and anticipates that up to 100 additional structures could be

 

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demolished under Alternative 1 (Table 2-1). Specific locations for future structure demolitions are unknown, but locations could be anywhere within the vicinity of the 3.1 ppb Cr(VI) groundwater contour.

Prior to demolition activities, a site assessment is conducted and the structures on the site are tested for hazardous materials (e.g., asbestos, lead-based paint), which if present are removed and properly disposed of at an approved facility in compliance with state and federal regulations. The site is fenced to prohibit public and wildlife access to the site, and existing utilities are identified and marked. Remaining structures are demolished, and materials are removed from the site. Septic systems are exposed, pumped, cleaned, inspected, removed from service, and backfilled. Domestic water supply wells are decommissioned (i.e., left in place) as described previously for decommissioning of groundwater monitoring wells. After site structures are removed or otherwise decommissioned, the site is re-graded to match existing topography and stabilize the disturbed soils. Stabilization of the site is implemented if no new facilities are to be built at the site. Existing driveways and roadways are generally used for access to structures to be demolished, and these are also often removed (if surfaced with concrete or asphalt) as part of the structure demolition process. Fencing is often removed after site work is complete, generally in 2 to 3 weeks.

Emergency Repairs In the event of an emergency situation, wells, pipelines, or other related structures may need repair. These activities would be in response to vehicle accidents, vandalism, small fires, material failure or other similar occurrences where facilities are unexpectedly damaged or present an emergency. The precise locations and quantities of facilities to be repaired during the next 50 years are unknown. For planning purposes, PG&E anticipates that up to 10 percent of the number of remediation facilities would require emergency repair. These emergency repairs are in addition to typical facility maintenance tasks previously described. While emergency repairs would thereby nominally increase the frequency of maintenance activities described previously, tasks required to make failed facilities operational would be as described previously for facility installation, operation, maintenance, and decommissioning. Emergency repair work would be performed in areas previously disturbed during the initial installation of facilities. These emergency repairs are in addition to typical facility maintenance tasks previously described. Tasks required to make failed facilities operational would be as described previously for facility installation, operation, maintenance, and decommissioning. Emergency repair work would be performed in areas previously disturbed during the initial installation of facilities.

2.2.2                       Alternative 2: PG&E’s Proposed Hinkley Groundwater Remedy HCP

Under Alternative 2, the Service would issue an ITP to PG&E to implement their proposed HCP for remediation activities. Covered activities include those future actions proposed by PG&E that, when permitted and implemented, may result in legal incidental take of one federally listed species and one nonfederally listed species (collectively referred to as covered species) within the plan area during the term of the ITP. Therefore, Alternative 2 includes a conservation program for the avoidance, minimization, and mitigation of these impacts.

As described in Section 2.2.4 of the Hinkley HCP, PG&E would use a phased approach in implementing covered activities over the 50-year permit term. This section summarizes the proposed covered activities and other provisions relevant to all phases of remediation.

The Phase 1 remediation approach will focus on intensively treating that portion of the groundwater plume with the highest concentration of Cr(VI). In situ treatment facilities constructed in Phase 1 would include groundwater extraction and injection wells, both of which would be housed in subsurface vaults or surface enclosures. By-product treatment facilities and electrical substations could be developed.

Groundwater monitoring wells would be installed. Additional access roads would be constructed to access these new facilities. Some acquired residences could be demolished, some facilities decommissioned and some sites regraded and stabilized. All operable facilities, including those

 

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constructed in Phase 1, would be operated and maintained during Phase 1. PG&E estimates that Phase 1 construction activities would be conducted during the first year of HCP implementation (anticipated to be 2018).

Phase 2 remediation will focus on expanding agricultural treatment by constructing new ATUs in OU1 and OU2. The focus of Phase 2 remediation will be to treat those groundwater areas in the north with low concentrations of Cr(VI), should ongoing studies determine that elevated levels of Cr(VI) are from PG&E’s past activities. New facilities would include development of ATUs, installation of groundwater extraction wells, installation of conveyance piping, and construction of surface enclosures to house electrical and support facilities. Some in situ treatment facilities may be developed in the IRZ of OU1. Groundwater monitoring wells would be installed. Additional access roads would be constructed to access new facilities. Some acquired residences would be demolished, and some sites regraded and stabilized. All operable facilities, including those constructed in Phase 2, would be operated and maintained. PG&E estimates that Phase 2 construction activities would be conducted during years 2 and 3 of HCP implementation (anticipated to be 2019-2020).

Phase 3 remediation will further expand agricultural treatment in OU1 and OU2, and may develop some AT facilities in OU3. The focus of Phase 3 remediation (as in Phase 2) will be to treat those groundwater areas with low concentrations of Cr(VI). New facilities would include development of ATUs and installation of groundwater extraction wells. Development of additional conveyance piping and surface enclosures is not anticipated in Phase 3. Some in situ treatment facilities may be developed in the IRZ of OU1. Groundwater monitoring wells would be installed, and access roads would be created. Some acquired residences would be demolished, and some sites regraded and stabilized. All operable facilities, including those constructed in Phase 3, would be operated and maintained. PG&E estimates that

Phase 3 construction activities would be completed during years 4 through 7 of HCP implementation (anticipated to be 2021-2024).

Phase 4 remediation would encompass developing covered activities to the maximum extent. Additional in situ treatment facilities could be developed in the IRZ to treat high-concentration Cr(VI) groundwater. Additional ATUs and associated infrastructure could be developed in all OUs. Ex situ Treatment facilities and associated infrastructure could be developed in OU1 and OU2. Groundwater monitoring wells would be installed in all OUs. Additional access roads would be constructed in all OUs to access new facilities in all OUs. Some acquired residences could be demolished, and some sites re-graded and stabilized. All operable facilities constructed to date, including those constructed in Phase 4, would be operated and maintained. As described earlier in this chapter, conveyance piping, roads, and ATU fields would be left in place, and abandoned or used for purposes other than groundwater remediation, at the completion of the permit term. Wells (groundwater extraction, injection, and monitoring) would be decommissioned and removed as described previously. Facility enclosures would be demolished as described previously. PG&E estimates that Phase 4 construction activities would occur during years 8 through 50 of HCP implementation (anticipated to be 2025-2068).

2.2.2.1         Covered Activities in the Remediation Area

Covered activities under Alternative 2 would be similar to those described for Alternative 1, but would add ex situ treatment during Phase 4, and infiltration gallery operation during Phases 2, 3, and 4. The remediation activities and quantities of associated facilities that would be constructed, operated, and maintained during the proposed permit term are summarized in Table 2-2, and are described in detail in the following paragraphs. Implementation of the conservation program would be a covered activity.

Avoidance and minimization measures would be implemented during remediation and other covered activities. The conservation program also includes the acquisition and management of lands within the offsite conservation area for the benefit of covered species and, potentially, other sensitive resources.

 

 

 

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Table 2-2. Remediation Facilities to be Developed, Operated, and Maintained under Alternative 2 (Hinkley HCP)

 
   


Covered Activity                                 Existinga                             Future                                         Total

Groundwater Monitoring

 

Groundwater Monitoring Wells (units)

756

95

851

Investigative Borings (sites)

Not Applicable

10

10

Domestic Supply Wells (units)

Unknown

Remove 10 to 20 per year

Undefined

Freshwater Injection System

 

 

 

Extraction Wells (units)

4

0

4

Injection Wells (units)

7

0

7

Pipelines/Trenches (feet)

39,000

0

39,000

Agricultural Treatment

 

 

 

ATUs (field acres)

306

1,088b

1,394

Extraction Wells (units)

59

135

194

Pipelines/Trenches (feet)

43,565

103,809

147,374

Enclosures

0

12

12

In Situ Treatment

 

 

 

Extraction Wells (unit)

25

10

35

Injection Wells (unit)

100

50

150

Well Vaults/Enclosures (units)

125

60

185

Ethanol Dosing Facilities (units)

2

0

2

By-Project Facilities

0

2

2

Electrical Substations (units)

0

2

2

Pipelines/Trenches (feet)

30,566

11,799

42,365

Ex Situ Treatment

 

 

 

Extraction Wells (units)

 

Use AT Extraction Wells

 

Injection Wells (units)

0

31

31

Pipelines/Trenches (feet)

0

41,816

41,816

Process Facilities

0

2

2

Other

 

 

 

Access Roads (miles)

54

15

69

Structure Demolitions (units)

Not Applicable

up to 100

up to 100

a Existing conditions updated through December 31, 2016

b Up to 200 acres of infiltration galleries could be substituted for an equivalent acreage of ATUs as described in text.

 

Groundwater Monitoring

Construction: As described for Alternative 1, 756 groundwater monitoring wells were installed as of December 31, 2016. Under Alternative 2, 95 additional groundwater monitoring wells could be installed during the permit term (Table 2-2). The procedures used to install new groundwater monitoring wells are the same as described for Alternative 1. Precise locations for future investigative borings and groundwater monitoring wells are not known. However, future groundwater wells are anticipated to be installed and operated at locations away from existing wells to track potential plume movement and remediation success beyond the locations currently covered by the existing array of monitoring wells.

New wells also may be installed when existing wells fail and cannot be repaired to remain in service.

 

 

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Investigative borings and installation of groundwater monitoring wells would be as described under Alternative 1.

Operations and Maintenance: Up to 851 wells are anticipated to be monitored and maintained annually during the permit term (Table 2-2). Operation and maintenance of new and existing wells would be as described above under Alternative 1. Following installation, groundwater monitoring wells do not routinely require maintenance because they are passively operated and are not generally powered with pumps.

Decommissioning: Up to 851 groundwater monitoring wells could be decommissioned during the 50-year permit term using the same procedure described under Alternative 1.

Freshwater Injection System

There is no difference between Alternative 1 and Alternative 2 for Freshwater Injection System. Under Alternative 2, no additional freshwater injection system facilities are anticipated to be constructed in the permit term. Operation, maintenance, and decommissioning of existing facilities would occur as described under Alternative 1.

Agricultural Treatment

Construction: Under Alternative 2, PG&E may expand existing agricultural treatment and develop up to 1,088 additional acres of ATUs (to 1,394 acres total), install up to 135 new groundwater extraction wells (to 194 total), and excavate up to 103,809 feet of new trenches (to 147,374 feet total) for conveyance pipelines to link new agricultural treatment extraction wells to new ATU fields. Development of new ATUs involves clearing land, amending soils with mulch, planting crops, and installing irrigation systems (including extraction wells and conveyance pipelines) and tortoise exclusion fencing as described for Alternative 1. To support the core infrastructure, up to 12 equipment enclosures (small buildings) will be constructed in the plan area. These would include up to eight electrical enclosures (i.e., power drops and control panels), up to two extraction valve manifold enclosures, and up to two booster pump enclosures. Six support enclosures are expected to be constructed in OU1, with six constructed in OU2. Each of the 12 enclosures will permanently occupy 225-square-foot pads (15 feet by 15 feet) and require construction areas of 75 feet by 75 feet (Table 2-2).

The exact locations of future agricultural treatment facilities are unknown, but most (about 90 percent) of the acreage occupied by future agricultural treatment facilities (ATUs, wells, pipes) is likely to be developed in OU1 and OU2 to treat low to moderate concentration (generally, less than 10 ppb) areas of the Cr(VI) plume (Figure 2-3). Up to 10 percent of the acreage occupied by future agricultural treatment facilities could be located in OU3. Future AT extraction wells will likely be developed outside of the ATU they irrigate.

Up to 200 acres of infiltration galleries may be developed and used to supplement agricultural treatment to accomplish groundwater remediation goals. Infiltration galleries reduce Cr(VI) to Cr(III) by adding carbon substances such as ethanol to extracted groundwater, with the treated water percolated through the soil using perforated pipes. This reduction process is similar to the in situ treatment process. Alternative 2 assumes that all infiltration galleries would be built and operated. The total acreage of infiltration galleries constructed (200 acres) will be debited from the total acreage of ATUs that could be constructed (1,088 acres) during the permit term. Thus, the combined acreage of ATUs and infiltration galleries that could be developed during the permit term is 1,088 acres. Extraction wells and conveyance pipelines that would deliver groundwater to ATUs would provide groundwater to infiltration galleries (collectively, the construction and operation of AT and infiltration gallery facilities are described as AT operation).

Operations and Maintenance: Operation and maintenance of AT facilities under Alternative 2 will be very similar to under Alternative 1. However, more facilities would be operated and maintained during

 

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the permit term under Alternative 2. Weed management at ATUs would be the same under both alternatives, as PG&E would continue to implement the approved IPMP (Arcadis, 2014a).

Not all ATUs proposed at full build-out (1,394 acres total) will be operable at any given time. That is, some ATUs may be operated only in the event that an array of operational ATUs is not functioning properly. For example, during prolonged storm events, optimal infiltration rates within an array of ATUs may be constrained because of saturated soils. In this circumstance, the application rate within the array of operable ATUs may be reduced, and additional ATUs may be activated at reduced application rates to achieve an overall target infiltration rate. Alternative 2 assumes that all 1,394 acres of ATUs will be built- out to accommodate this operational flexibility. As described above, infiltration galleries could also be operated to assist under-performing ATUs.

PG&E estimates that up to 14,737 feet (10 percent of total pipe extent) of conveyance pipeline could require emergency repair during the 50-year permit term. Pipeline repair would be as described under Alternative 1.

Decommissioning: Under Alternative 2, agricultural treatment facilities would be decommissioned using the same processes described for Alternative 1. However, more facilities (number and area coverage) would be decommissioned under Alternative 2. Infiltration gallery percolation pipes would be left in place and not removed following remediation completion. As described under Alternative 1, agricultural treatment extraction wells removed during the permit term would be removed from previously disturbed areas, and no new habitat disturbances are anticipated with this activity.

In Situ Treatment

Construction: Under Alternative 2, up to 40 additional in situ well vaults (each up to 16 square feet in area) housing up to 10 new extraction wells and up to 30 new injection wells (one well per vault) could be developed in the IRZ of OU1 during the permit term (Figure 2-4). Up to two new electrical substations (each building/structure approximately 144 square feet in area) could be constructed and operated in the IRZ of OU1 during the permit term. Up to 11,799 linear feet of new pipeline trenching would be associated with expanded in situ treatment at full build-out. Construction of a new in situ treatment vault requires a temporary work area of up to 10,000 square feet (100 feet by 100 feet), similar to the work area of a groundwater monitoring well.

Operations and Maintenance: Under Alternative 2, more facilities would be operated and maintained than under Alternative 1, but the operation and maintenance (O&M) procedures would be the same. New byproduct treatment facilities (n=2) and electrical substations (n=2) could be operated and maintained in Alternative 2.

The in situ treatment process could temporarily and locally increase concentrations of byproduct metals such as dissolved arsenic, iron, and manganese in the groundwater. Slowing the rate of reductant injections could mitigate this secondary contamination. However, if reducing the rate of in situ treatment injections does not effectively curb the production of byproduct metals, or should slowing injection rates not be otherwise feasible, more groundwater extraction wells could be installed and operated to intercept these groundwater byproducts. The number and location of additional groundwater extraction wells for this purpose are not known.

By-product treatment facilities may be used to precipitate the metals out through oxidation or like PG&E’s previous system where water is injected in to dry wells where the metals are oxidized and precipitated out of the water. Up to two by-product treatment facilities could be constructed over the permit term. The footprint of each facility would be approximately 400 square feet (20 feet by 20 feet). The precise locations of future by-product treatment facilities are not known at this time. However, the Water Board’s Final Environmental Impact Report (FEIR) (2013) noted that by-product mitigations would be located down-gradient (north) of the IRZ treatment boundary to intercept or reduce reagent concentrations and secondary by-products to prevent impacts to domestic supply wells. Future

 

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byproduct treatment facilities could be constructed and operated in the north portion of OU1, or the southern portion of OU2 immediately north of and adjacent to OU1. As described for Alternative 1, PG&E operated 94 sentry wells (subset of groundwater monitoring wells) in the fourth quarter of 2014 to assess the effectiveness of in situ treatment, and to assess the presence, concentration, and movement of by-product metals in groundwater.

PG&E estimates that up to 4,237 linear feet (10 percent of total pipe extent) of in situ treatment conveyance pipeline could require emergency repair during the permit term. Pipeline repair would be as described under Alternative 1.

Decommissioning: Decommissioning of in situ treatment facilities would be within areas previously disturbed by construction as described above for the Alternative 1. More facilities would be decommissioned under Alternative 2 than under Alternative 1.

Ex Situ Treatment

Ex situ (aboveground) treatment is intended to supplement agricultural treatment, particularly during winter months when the demand for crop irrigation water is much less than during warmer growing months, resulting in a relative excess of extracted groundwater that cannot be treated by ATUs. During ex situ treatment, contaminated groundwater would be extracted at AT extraction well sites and piped to ex situ treatment facilities, Cr(VI) would be chemically precipitated and filtered from the extracted groundwater, and treated groundwater would be re-injected to the aquifer. The solid chromium residue generated during ex situ treatment would be containerized and transported to a Class I landfill that is permitted to accept hazardous wastes (e.g., Waste Management Kettleman Hills Facility in Kings County). Ex situ treatment has not been implemented to date in the project area, but may be implemented in OU1 and OU2 under Alternative 2 to remediate Cr(VI) plume concentrations of greater than 10 ppb. Ex situ treatment equipment will likely be housed in a facility or enclosure.

Construction: Up to two ex situ treatment facilities may be constructed, operated, and maintained in the plan area throughout the permit term. Exact locations for ex situ treatment facilities have not been identified, but one may be located near the Hinkley Compressor Station in OU1, and a second facility may be located near the Desert View Dairy ATU adjacent to the northwestern boundary of OU2.

Each ex situ treatment facility would permanently occupy an area of up to 40,500 square feet (on average, 200- by 200-foot footprint) and be up to 35 feet high. Facilities would contain up to 31 new injection wells (total), conveyance pipelines, a process building and an office/laboratory, and security fencing. The process building would house equipment to treat contaminated groundwater. The area within the fenced facility would be paved. Contaminated groundwater would be extracted via existing agricultural treatment extraction wells, conveyed to new ex situ treatment facilities with up to 41,816 linear feet of new buried pipeline, treated, and reinjected to the aquifer. A construction area of 500 feet by 500 feet would be required for each ex situ treatment facility.

Construction of the ex situ treatment facilities would involve site preparation through grading and excavation, paving and concrete pouring for building foundations, and construction of the treatment facility building and other structures. New utilities including power connections (including backup diesel generators), septic systems (for nonprocess and nonlaboratory wastewater [staff bathrooms]), and telecommunications connections also would be installed. Construction equipment may include excavators, backhoes, water trucks, small equipment (compactor, welder, trencher, etc.), and support trucks. Construction of conveyance pipelines would be as described previously and would require an approximately 50-foot-wide work area.

Operations and Maintenance: With the exception of conveyance pipelines and repurposed agricultural treatment extraction wells, operation and maintenance of the two future ex situ treatment facilities would be fully contained within the new enclosures. Operational activities would include daily staff transportation to and from the facilities, monitoring and controlling groundwater extraction and

 

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conveyance rates, analyzing groundwater chemistry, and scheduling and managing materials deliveries and facility waste pickup. Periodic inspections and maintenance would be conducted as needed.

Underground conveyance pipelines are anticipated to require maintenance only in the event of a catastrophic or unanticipated failure. PG&E estimates that up to 4,182 linear feet (10 percent of total pipe extent) of ex situ treatment conveyance pipeline could require repair during the permit term.

Pipeline repair would be as described previously for agricultural treatment and in situ treatment pipelines under Alternative 1.

Decommissioning: PG&E would likely decommission and remove ex situ enclosures and associated facilities at completion of remediation. Decommissioning of ex situ facilities would be as described above for decommissioning of in situ facilities under Alternative 1.

Other Covered Activities

In addition to the monitoring and remediation activities described above, Alternative 2 also includes the following activities.

Access Roads: Under Alternative 2, PG&E may construct up to 15 additional miles of unpaved access roads to access remediation facilities in the permit term. PG&E would use and maintain up to 69 total miles of unpaved access roadways in the plan area. Future access roads would likely have the same width as current access roads (i.e., 10 feet wide with 3-foot shoulders). Road construction includes vegetation grubbing (clearing), roadbed grading and compaction, and road surfacing with gravel as described for Alternative 1. Maintenance of access roads would be as described under Alternative 1. Under Alternative 2, PG&E will render unpaved remediation access road inaccessible at the end of the permit term by creating unpassable barriers (graded berms) at their origins.

Structure Demolition: Structure demolitions under Alterative 2 would be identical to those completed under Alternative 1. Areas disturbed as a result of structure demolitions would continue to be graded and stabilized to prevent site erosion, similar to Alternative 1.

Emergency Repairs Emergency repairs of remediation facilities, pipelines, and structures would proceed as described under Alternative 1, but more facilities would be present under Alternative 2 compared to Alternative 1. The magnitude of emergency repairs anticipated during the permit term is summarized in Table 2-3.

 

  Table2-3. Emergency Facility Repairs Anticipated under Alternative 2                                                                                    

 
   


Facility                                                           Anticipated Emergency Repairs in Permit Term

Groundwater Wells (monitoring, extraction, injection)                     Up to 124 wells

Conveyance Pipelines                                                                         Up to 26,922 linear feet

ATUs and Infiltration Galleries combined                                          Up to 139 acres

Vaults/Surface Enclosures (in situ, ex situ)                                        Up to 5

 
   


Access Roads                                                                                      Up to 7 miles

 

2.2.2.2         Covered Species

Under Alternative 2, PG&E is requesting coverage for incidental take of Gopherus agassizii, a federally listed threatened and state-listed threatened species. Common names for this species have varied through time and have included Agassiz’s desert tortoise, Mojave desert tortoise, and Mojave population of desert tortoise. Within this document, we have used “desert tortoise” to refer to the listed taxon G. agassizii. PG&E is also requesting coverage for incidental take of Mohave ground squirrel (Xerospermophilus mohavensis), a California-listed threatened species.

 

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The plan area is within the geographic range of the desert tortoise and Mohave ground squirrel. Desert tortoise have been detected and suitable habitat for this species occurs in the plan area. Mohave ground squirrel may be present and suitable habitat for this species occurs in the plan area. The plan area is located within a portion of the Superior-Cronese Area of Critical Environmental Concern (public land portion is managed by the Bureau of Land Management [BLM]), one of eight desert tortoise Critical Habitat Units (CHUs) designated in California.

2.2.2.3         Conservation Program

This section describes the conservation program that PG&E would implement to achieve the HCP’s biological goals and objectives. The conservation program was designed to meet the regulatory requirements of the ESA and California Endangered Species Act (CESA), and to streamline compliance with NEPA, the California Environmental Quality Act (CEQA), and other applicable environmental regulations. The conservation program seeks to avoid, minimize, and mitigate adverse effects to covered species and their habitats and to contribute to their conservation. The following describes the suite of Conservation Measures (CMs) that PG&E will commit to implement to achieve the HCP’s biological goals and objectives.

CM-1:        Designate HCP Administrator, Authorized Biologist(s), and Biological Monitors.Following issuance of the ITP and prior to implementing the HCP, PG&E will designate an HCP Administrator to oversee implementation of the Hinkley HCP Program, and will nominate biologists to work under the direction of the HCP Administrator. The HCP Administrator and biologists shall have experience surveying for desert tortoise and Mohave ground squirrel and have knowledge and field experience regarding the biological and ecological needs of the covered species. The nominated biologist(s) will complete and sign the Desert Tortoise Authorized Biologist Request Form and submit it to the agencies for their approval at least 30 days prior to initiation of activities (USFWS, 2009). The duties of and authorization process for a Desert Tortoise Authorized Biologist (Authorized Biologist) are located in Chapter 3 of the Desert Tortoise Field Manual Service (USFWS, 2009). Desert Tortoise Monitors (Biological Monitors) will be approved by the Authorized Biologist(s).

The Biological Monitors will work under the direction of the Authorized Biologist except as discussed below in some situations. Only Authorized Biologists would be able to handle (unless it is to move a tortoise from harm’s-way when a desert tortoise enters a project site as noted in the Service’s Field Manual), temporarily hold, translocate, or excavate burrows of desert tortoise or desert tortoise eggs and these tasks would not be administered by the Biological Monitor.

The Authorized Biologist may approve Biological Monitors to complete clearance surveys for activities without the presence of an Authorized Biologist when all the following criteria are met:

  • Surveys are completed within the region delineated on Figure 2-5, which generally identifies low-value habitat and nonhabitat areas
  • Surveys are completed within Disturbed and Urban/Agricultural land cover types as described in the HCP
  • Less than 1 acre will be disturbed from an activity

The Service and CDFW will allow the Biological Monitor to work with these added responsibilities as an exception to the Service’s Field Manual (which limits clearance surveys to an Authorized Biologist only) because the permit term for this project is 50 years and because numerous, frequent, and minor new construction activities are anticipated to occur

 

 

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over the permit term in disturbed areas (as described in HCP Section 3.4.2) requiring pre- activity clearance surveys under this permit.

Figure 2-5 shows the geographic region within which Biological Monitors may conditionally perform desert tortoise clearance surveys (generally, limited to developed and disturbed areas in and near OU1 and OU2). Non-habitat and low-value habitat areas within the plan area were identified by SBI (2013) field efforts, and modeled remotely by Nussear et al. (2009).

CM-2:        Conduct Environmental Awareness Training.PG&E will ensure that all employees, subcontractors, and others who work in or visit the plan area on PG&E business, complete an Environmental Awareness Training Program approved by an Authorized Biologist prior to initiation of their duties in the plan area. PG&E is responsible for ensuring that the awareness program is presented prior to conducting work activities. Hard hat stickers and wallet-sized cards listing key best management practices will be distributed to identify personnel who have attended training sessions. At a minimum, the awareness program will emphasize the following information:

  • General behavior and ecology of covered species
  • Sensitivity of covered species to human activities
  • Legal protections for covered species
  • Penalties for violating state or federal laws
  • Reporting requirements
  • Worker prohibitions
  • HCP avoidance and minimization measures

The Authorized Biologist and/or Biological Monitor will ensure that all workers have completed the Environmental Awareness Training and that they understand the objectives of the training program.

CM-3:        Worker Prohibitions.Workers will be prohibited from bringing pets or firearms to the plan area and will be prohibited from feeding wildlife and littering. Smoking shall be strictly controlled to prevent accidental ignition of wildfires. PG&E will designate smoking areas within the plan area and will restrict smoking to these areas only.

CM-4:        Identify and Delineate Planned Work Areas. In areas where it is not practical for PG&E to install desert tortoise exclusion fencing (CM-14), work area boundaries and access roads will be delineated with flagging or other marking to minimize surface impacts. All impact limits need to be confirmed by the Biological Monitor. Special habitat features, such as burrows identified by the Biological Monitor, will be avoided to the extent possible. The work area will be monitored by the Biological Monitor during surface disturbing activities.

CM-5         Avoid Activities in Designated Conservation Lands.PG&E will design and locate facilities and activities to avoid impacts within mapped Superior-Cronese CHU lands, and within BLM- designated and managed conservation lands, where possible.

CM-6:        Limit Disturbances within Covered Species Habitats.The area of impact will be confined to the smallest practical area, considering topography, placement of facilities, location of occupied desert tortoise and Mohave ground squirrel habitat, public health and safety, and other limiting factors, and will be located in previously disturbed areas to the extent possible.

When avoidance of suitable habitat for covered species is not practical, PG&E will locate, construct, operate, and maintain facilities, and implement other covered activities, in lower quality habitat areas and will avoid impacts within higher quality habitat areas, to the extent possible. As described in Chapter 3, lower quality habitat areas are those portions of the plan area that have been historically impacted, but are recovering.

 

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The Authorized Biologist and/or Biological Monitor will assist in locating such areas to avoid desert tortoise and Mohave ground squirrel mortality/injury, minimize impacts to habitats, and ensure compliance with this measure. PG&E will document habitat avoidance and minimization efforts and will include these records in annual reports to the agencies.

CM-7:        Use Established Travel Routes and Enforce Road Speeds. To minimize the potential for impacts to covered species’ habitats and individuals, project personnel will use established road (paved or unpaved) to travel to and from work areas. Cross-country vehicle and equipment use outside designated access roads and designated work areas will be prohibited. Except on paved roads with posted speed limits, vehicle speeds will not exceed 10 miles per hour through/adjacent to covered species’ habitats during travel associated with covered activities.

CM-8:        Control Dust and Avoid Ponding/Pooling of Water.Dust associated with implementation of covered activities will be controlled to minimize indirect impacts to covered species habitat. If water is applied to roads or project sites to control dust, pooling of water will be avoided to minimize the potential to attract common ravens or other covered species’ predators.

CM-9:        Reduce Night Light Spillover.Exterior light fixtures and standards will be designed to be fully shielded, directing light downward below the horizontal plane of the fixture height. The biologist will confirm that the lighting plans have been reviewed and that night lighting spillover has been minimized and is not expected to result in indirect impacts to covered species.

CM-10:     Control Predator Food Subsidies. Litter control measures will be implemented. Trash and food items will be contained in closed containers and removed daily to reduce the attractiveness of the area to opportunistic predators such as common ravens, coyotes, and feral dogs.

CM-11:     Avoid Introduction and Spread of Invasive Plants.PG&E will ensure that when it is reseeding disturbed areas the proposed seed palette will be reviewed by the HCP Administrator to verify the seed mix does not contain non-native plants or plants that are considered invasive in California (based on the California Invasive Plant Inventory Database). To reduce the introduction and spread of noxious weeds in the plan area, off-road equipment that is not local to the plan area will be clean and free of mud or other debris that may contain invasive plants and/or seeds before entering the plan Area. The Service and CDFW will review and approve seed mixes prior to their HCP-use in the plan area.

CM-12:     Pre-Activity Clearance Surveys.Prior to implementation of a ground-disturbing covered activity at a project site (including installation of desert tortoise exclusion fencing), PG&E will ensure that the Authorized Biologist and/or Biological Monitor completes a pre-activity survey for covered species within each work area to ensure that covered species are absent. Desert tortoises found within the work areas will be either allowed to move passively away or be physically relocated by an Authorized Biologist to a location out of harm’s way, but within their home range (defined as less than 1,000 feet [USFWS, 2009]). Work shall not commence at a project site until covered species have been cleared from the site. A Biological Monitor will be present during installation of exclusion fencing. Once fencing is installed, an Authorized Biologist and/or Biological Monitor will complete clearance surveys for desert tortoises. All survey methods, fence design, and qualifications will comply with standards/ recommendations by the agencies.

CM-13:     Monitoring of Covered Species During Construction. Following pre-activity surveys, installation of exclusion fencing, and completion of clearance surveys by the Authorized Biologist and/or Biological Monitor, a Biological Monitor will conduct daily monitoring of the

 

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exclusion fencing, and all work areas within the fenced area during clearing and grubbing (initial ground disturbance). Once clearing and grubbing is complete, a Biological Monitor will conduct, at minimum, weekly spot checks to document compliance with the conservation measures presented in this HCP. An on-call, Authorized Biologist will be available should a desert tortoise be encountered during construction activities. Ongoing construction monitoring will also ensure that desert tortoises observed within 100 feet of construction are actively monitored for a negative response from work activities. PG&E will conduct biological monitoring for facility O&M and decommissioning when these activities involve ground- disturbing actions outside of desert tortoise exclusion fenced areas. See also CM-14.

CM-14:     Desert Tortoise Exclusion Fence Installation and Maintenance. Where possible, desert tortoise exclusion fencing will be placed along the perimeter of the proposed work areas prior to surface disturbance to prevent encounters with desert tortoise during construction, operation and maintenance, and decommissioning activities. The specifications of the desert tortoise exclusion fencing will follow the most recent specification established by the Service. Immediately after exclusion fence construction, and prior to ground disturbing activities within the fenced area, the Authorized Biologist and/or Biological Monitor will conduct a clearance survey following the Service’s protocol to ensure that desert tortoises are absent from the work area. Permanent desert tortoise exclusion fencing will also be installed and maintained around all permanent buildings and structures where entrapment or negative interactions with tortoises could occur. All ATUs will have permanent desert tortoise exclusion fencing. Exclusion fence damage will be repaired within two days of observing the damage.

Desert tortoise-proof gates will be installed at all entry points to ATUs and other permanently fenced facilities requiring frequent human ingress and egress. Single-slot tortoise guards may be installed in lieu of tortoise-proof gates for access to permanently fenced facilities when exclusion fencing is installed within the area delineated on Figure 2-5.

Temporary fencing may be used for smaller, isolated construction activities where routine postconstruction operations are not anticipated. Temporary fencing will be constructed of material satisfactory to the agencies and consistent with current Service specifications.

Fulltime biological monitoring may be implemented instead of installation of exclusionary fencing for short duration activities, at the discretion of the Authorized Biologist and/or Biological Monitor. Short duration activities would be activities lasting less than a week, where it is more feasible and practical to have Authorized Biologist and/or Biological Monitor onsite full time than to construct temporary tortoise fencing around an activity.

CM-15:     Equipment Inspections. Desert tortoises commonly seek shade or cover during the day. During implementation of covered activities, workers will be required to visually inspect beneath vehicles, equipment, and stockpiled materials (e.g., pipes, etc.) prior to moving them if parked outside of fenced work areas. If a desert tortoise is discovered, the vehicle or equipment shall not be moved until the tortoise has moved a safe distance on its own, or is relocated by an Authorized Biologist. Open-ended pipes will be capped to ensure that covered species do not use them for cover when activities occur in open desert without the use of desert tortoise exclusion fencing. Excavations, including trenches, will be similarly covered when not active to prevent covered species entrapment if areas of activity in the open desert are not protected by desert tortoise exclusion fencing.

CM-16:     Desert Tortoise Translocation Plan.Prior to moving desert tortoises, PG&E shall document agency review and approval of the Desert Tortoise Translocation Plan. PG&E shall implement the plan as revised through incorporating any/all changes required for agency approval. An accounting of desert tortoises relocated will be included in the annual report to the agencies. The current Translocation Plan is attached to the HCP as Appendix J.

 

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CM-17:     Raven Management. PG&E is implementing a Common Raven Management Plan (RMP) to reduce raven predation on desert tortoises (Arcadis, 2017a). The RMP includes an approach to document the common raven pre-project population reference level (baseline); methods for ongoing and postconstruction monitoring of common raven populations, and triggers for adaptive management. Measures are proposed in the RMP to limit food and water resources, and to limit nesting and perching opportunities, for common ravens in the plan area. Should raven monitoring during the permit term indicate that ravens are increasing in abundance in the plan area, the RMP notes that additional raven management measures would be implemented to manage common ravens. Implementation of the RMP is incorporated to the HCP as a Conservation Measure commitment. The RMP is attached to the HCP as Appendix K.

PG&E will also manage raven effects to desert tortoises on a regional scale by participating in a raven management program administered the National Fish and Wildlife Foundation (NFWF). The NFWF is a 501(c)(3) nonprofit organization that administers funding from an Impact-Directed Environmental Account. NFWF funding will be used to implement raven management measures consistent with the Service’s Environmental Assessment to Implement a Desert Tortoise Recovery Plan Task: Reduce Common Raven Predation on the Desert Tortoise (USFWS, 2008b). PG&E will work with the Service to establish a per-acre impact fee to be deposited with the NFWF for the purpose of managing ravens on a regional scale for the benefit of desert tortoise (and Mohave ground squirrel).

CM-18:     Covered Species Observations.All covered species observed at a project area must be immediately reported to the Biological Monitor, and any activity putting the covered species at risk must be halted until an Authorized Biologist is able to relocate the desert tortoise from harms-way, or the animal passively moves from the work site on its own. Halted work shall not resume without the approval of the Authorized Biologist and/or Biological Monitor. The Authorized Biologist and/or Biological Monitor will immediately notify the HCP Administrator. All covered species observations, whether they result in work stoppages or not, will be recorded by the HCP Administrator and included in HCP reporting.

CM-19:     Mortality or Injury of Covered Species.If a desert tortoise or Mohave ground squirrel is injured or killed in the plan area while conducting covered activities, the Authorized Biologist, Biological Monitor, and HCP Administrator must be immediately notified. If the mortality or injury is at a project site, work shall be stopped until the Authorized Biologist and HCP Administrator assesses the situation. The HCP Administrator shall immediately contact the agencies to report and document the injury or death, and to receive instruction on the disposition of the dead or injured animal, which may include transporting injured individuals to a qualified veterinarian. Work shall not resume at the work site without approval of the HCP Administrator. PG&E shall keep an updated list of nearby veterinarians on hand.

CM-20:     Secure and Manage Conservation Lands.PG&E will acquire in fee title, secure a conservation easement, purchase mitigation bank credits, or work with a third-party entity to identify, secure, and manage in-perpetuity up to 1,798 acres of suitable covered species habitat at a location or locations approved by the agencies. Mitigation lands shall be secured prior to incurring plan area impacts. Detailed information is provided in HCP Section 5.3.3, and in the following paragraphs (PG&E’s Compensatory Mitigation).

Conservation Approach for Avoiding and Minimizing Direct and Indirect Impacts to Covered Species Habitat

The conservation approach for avoiding and minimizing impacts to covered species habitat relies on maintaining an accurate accounting and location of land cover types and land uses (both PG&E and non- PG&E lands) in the plan area, avoiding impacts to suitable habitat areas when possible, and minimizing and tracking the nature and extent of habitat impacts that cannot be avoided.

 

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PG&E will ensure that qualified persons administer and implement the HCP (CM-1), and that all PG&E employees and contractors completing or participating in covered activities have been adequately trained to avoid and minimize impacts to suitable Covered Species habitats (CM-2).

Impacts to desert tortoise habitat will be avoided by ensuring that remediation staff (PG&E employees and contractors) work closely with the Biological Monitor to, for example, plan work activities and locate facilities within nonhabitat areas, when possible, and within lower-quality habitat areas when avoidance of suitable covered species habitat cannot be accomplished. Higher quality habitat areas will only be disturbed when there are no feasible options (CM-6). Designated conservation lands (i.e., Critical Habitat and BLM-managed, Desert Renewable Energy Conservation Plan [DRECP]-designated conservation lands) shall be similarly avoided, if feasible (CM-5).

When work areas for covered activities have been identified, PG&E will ensure that limits of work areas are delineated in the field (CM-4). Vehicular travel will be limited to established access roads and off- road travel will be prohibited (CM-7). Speed limits on unpaved access roads shall not exceed 10 miles per hour (CM-7) to minimize dust impacts to habitat areas (CM-8) and to avoid and minimize the potential for vehicle strikes to covered species individuals. Invasive plant species shall not be used for site stabilization efforts (CM-11).

Conservation Approach for Avoiding and Minimizing Direct and Indirect Impacts to Covered Species

The conservation approach for avoiding mortality and injury to covered species individuals begins with avoiding impacts to habitat (and thus, avoiding harm and harassment of covered species), but is heavily reliant on focused species surveys before and during initial land disturbing activities and facility construction, and the ability to control the location, flow, and pace of construction activities.

After designating and obtaining approval from the wildlife agencies of qualified persons to administer and implement the HCP (CM-1), and after conducting Environmental Awareness Training (CM-2), PG&E will impose and enforce limitations on covered activities that could take covered species. These include identifying and clearing delineated work areas (CM-4 through CM-6), and regulating vehicular traffic in the plan area while completing covered activities (CM-7 and CM-8). Site workers will be prohibited from bringing firearms and pets to project locations, prohibited from smoking except in designated smoking areas, and will be prohibited from feeding all wildlife (CM-3).

Pre-activity surveys will be conducted at all project sites in advance of ground-clearing/ground- disturbing activities (CM-12). If available, approved survey protocols will be used for such clearance surveys. Desert tortoises detected during pre-activity surveys will be allowed to move from harm’s way on their own, or will be moved from harm’s way by an Authorized Biologist implementing measures in the agency-approved Desert Tortoise Translocation Plan (CM-16).

Once activity sites are considered clear of desert tortoises, PG&E will install temporary exclusion fencing around the perimeters of work areas to prevent encounters with desert tortoises during work activities (CM-14). Exclusion fencing will be installed under the direction of the Biological Monitor (CM-14), and fencing will be inspected daily to ensure its structural integrity (CM-13). Exclusion fence damage will be repaired within two days of observing the damage, followed by repeating clearance surveys (CM-12).

Biological Monitors will conduct daily monitoring clearance surveys of work areas during initial ground disturbance (fenced and unfenced) to ensure that covered species individuals are not present at work areas (CM-13). PG&E will ensure that areas that are stabilized (e.g., construction work areas, cleared residential structures) use native plant species that provide food and/or cover value to desert tortoises, and do not contain non-native or invasive species. Off-road construction equipment will be verified to be free and clear of weed propagules prior to their use in the plan area (CM-11).

Specific conservation measures will be implemented to avoid and minimize the potential for killing or injuring desert tortoises during construction or decommissioning activities. Workers shall be required to visually inspect beneath vehicles, equipment, and stockpiled materials prior to moving them if located

 

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outside of desert tortoise exclusion fenced work areas (CM-15). Desert tortoises observed during vehicle or material inspections shall be allowed to move from harm’s way on their own, or will be moved to a safe location by an Authorized Biologist according to the agency-approved Desert Tortoise Translocation Plan (CM-16).

Covered species observed within the plan area must be immediately reported to the Biological Monitor (CM-18). If the Biological Monitor determines that work being conducted potentially would result in injury to the tortoise, work will be immediately halted and shall not resume without approval of the Biological Monitor. Individual desert tortoises at risk may be allowed to leave the work area on their own, or may be moved from harm’s way by an Authorized Biologist according to the Desert Tortoise Translocation Plan (CM-16). If a desert tortoise is injured or killed by covered activities, or is observed injured or killed by unknown causes, the Authorized Biologist and HCP Administrator shall be immediately notified. If the mortality or injury is a result of the activity, the activity will be stopped. The HCP Administrator shall immediately contact the agencies to report the injury/mortality, and will receive direction on how to proceed. Work shall not resume at that location without approval of the HCP Administrator (CM-19).

PG&E has prepared an RMP to ensure that covered activities do not expose desert tortoise to elevated, project-related predation risks from common ravens (CM-17). The RMP proposes to manage food, water, nesting/roosting, and perching resources in the plan area to reduce raven abundance and potential predation on tortoises. Under the RMP, PG&E would monitor ravens to estimate the baseline (or pre-HCP abundance) of ravens in the plan area, and would monitor during HCP implementation to detect changes in raven abundance through time that may be attributed to HCP implementation. Should such monitoring indicate that ravens are increasing in abundance in the plan area due to HCP implementation, PG&E may propose additional measures to manage the abundance of common ravens. PG&E will also contribute to management of ravens at a regional scale for the benefit of desert tortoises and Mohave ground squirrels through an NFWF-administered program (CM-17).

PG&E will manage the indirect, potentially adverse effects of nighttime lighting on desert tortoise by ensuring that nighttime lighting is minimized, and that light fixtures are shielded to direct light downward from the horizontal plane of the fixture (CM-9). Tortoises located within 100 feet of active construction sites will be monitored to ensure that they do not display negative reactions from work activities (CM-13).

PG&E’s Compensatory Mitigation

While implementation of the conservation measures described above is expected to avoid or substantially minimize take of covered species and loss/degradation of suitable habitat, PG&E recognizes that some level of incidental take may occur during implementation of the covered activities. There could be both permanent and temporary disturbance/loss of high-value habitat areas and lower- value habitat areas for the covered species. To compensate for impacts to covered species habitats resulting from implementation of covered activities, PG&E would acquire in fee title, secure a conservation easement, secure purchase of mitigation bank credits, or work with a third party entity to identify, secure, and manage in-perpetuity up to 1,798 acres of suitable covered species habitat (CM-20) according to the following ratios:

  • 3:1 (mitigation to impact ratio) for permanent impacts to high–value habitat areas with no special designation (natural/undisturbed land cover types)
  • 3:1 for temporary impacts to high-value habitat areas with no special designation due to the slow recovery time of habitats in desert ecosystems
  • 1:1 for permanent impacts to lower-value habitat areas with no special designation (denuded/recovering areas)

 

 

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  • 1:1 for temporary impacts to lower-value habitat areas with no special designation due to the slow recovery time of habitats in desert ecosystems
    • 5:1 for permanent or temporary impacts to suitable habitat within designated Superior-Cronese CHU lands and DRECP-designated Areas of Critical Environmental Concern (ACECs)/Tortoise Conservation Areas (TCAs) on BLM-managed lands or non-BLM-managed lands.
    • 3:1 for permanent or temporary impacts to high-value suitable habitat and 2:1 for permanent or temporary impacts to low-value habitat within the DRECP-designated Fremont-Kramer TCA to Ord- Rodman TCA Linkage if located on BLM-managed lands.
    • 3:1 for permanent or temporary impacts to high-value suitable habitat and 1:1 for permanent or temporary impacts to low-value habitat within the DRECP-designated Fremont-Kramer TCA to Ord- Rodman TCA Linkage if located on non-BLM-managed lands.
    • 3:1 for permanent or temporary impacts to high-value suitable habitat and 1:1 for permanent or temporary impacts to low-value habitat within the DRECP-designated Harper Lake Mohave Ground Squirrel Key Population Center (KPC) Expansion Area or DRECP-designated Harper Lake KPC to Coolgardie Mesa-Superior Valley KPC Linkage, on BLM-managed lands or non-BLM-managed lands.
    • No compensatory mitigation for impacts (permanent or temporary) to nonhabitat areas (denuded/total, active agricultural, or residential/urban areas) anywhere in the plan area

Mitigation lands shall be secured prior to incurring plan area impacts.

PG&E has identified prospective areas for establishing the conservation lands. In identifying locations for conservation lands, the Service and National Marine Fisheries Service (NMFS) (1996) note that,

“Generally, the location of replacement habitats should be as close as possible to the area of impact; it must also include similar habitat types and support the same species affected by the HCP. However, there may be good reason to accept mitigation lands that are distant from the impact area— e.g., if a large habitat block, as opposed to fragmented blocks, can be protected or if the mitigation lands are obtained through a mitigation fund. Ultimately, the location of mitigation habitat must be based on individual circumstances and good judgment.”

The following characteristics may be used as guidance in selecting and securing conservation lands:

  • Located in the West Mojave Recovery Unit (WMRU)
  • Connectivity with other preserves
  • Located within or near TCA/ACEC or tortoise linkage
  • Habitat connectivity
  • Habitat intactness
  • Likelihood of covered species occupancy
  • Regional conservation
  • Likelihood of providing habitat in perpetuity

The general boundaries where conservation lands will likely be secured would be east of SR 395, south of Cuddeback Lake, west of Fort Irwin Road and north of SR 58. Elevations within this area generally range from 2,000 to 3,700 feet above sea level.

The conservation lands will be protected in perpetuity with a conservation easement that provides third party beneficiary rights to the Service. A management plan will be drafted for conservation lands, and an endowment will be established to fund the management and monitoring of these lands in perpetuity. A mitigation agreement will be drafted to identify responsibilities and obligations for management and

 

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monitoring of lands by involved parties. The fee title may be held by a private land owner, a nonprofit land trust or the State of California, or by PG&E. The conservation easement would be held by the State of California or a nonprofit land trust who is authorized to hold conservation easements, per California Civil Code 815.

Once conservation lands are identified for acquisition, and PG&E has received approval from the Service on the conservation land parcels, PG&E, its contractor, or a third-party entity, will prepare an agency- approved management plan describing how the lands will be managed and monitored. The management plan and conservation easement will be used to calculate the endowment to cover costs of management and monitoring in perpetuity through the use of PG&E’s endowment calculation tool. The endowment calculation shall include a 10 percent contingency factor to cover adaptive management, changed circumstances, and inflation. Supporting documentation for endowment calculations will be provided to ensure that funding is adequate. The agencies will review and approve the management plan, conservation easement, and endowment funding proposal, and mitigation agreement. Any potential enhancement activities to conservation lands would not be a requirement of the permit, although enhancement activities may be a component of the management plan.

PG&E will phase or sequence its remediation activities through time. Remediation techniques and strategies to be employed, and the specific locations and intensities of the activities will be dependent upon the successes of prior remediation. Should early remediation tactics successfully achieve groundwater cleanup objectives, some of the covered activities may not need to be implemented, or may only need to be implemented at reduced intensities and areas. With phased implementation of the covered activities, PG&E will ensure that compensatory mitigation commitments meet the timing and amount required during each phase. For timing, the appropriate amount of compensatory mitigation will be implemented prior to initiation of a covered activity. For amount, PG&E will ensure that the amount meets the ESA requirement to minimize and mitigate to the maximum extent practicable, and the CESA requirement to fully mitigate the impacts at any point in time during the permit term.

Implementation of the Conservation Program

PG&E will be responsible for the overall management and implementation of the HCP through a dedicated team of individuals that will implement the HCP. The HCP team will be overseen by a PG&E administrator (HCP Administrator) who will be responsible for ensuring successful implementation of the HCP. The Authorized Biologist, Biological Monitors and field crews will have responsibilities for implementing and following the CMs of the conservation program in the field.

The HCP Administrator will be a PG&E biologist, who will manage the implementation, monitoring, and reporting activities described in the HCP. The HCP Administrator will have the following primary responsibilities:

  • Serving as the point of contact between the agencies and the HCP team to resolve any issues about implementation of the HCP, including responses to Changed Circumstances
  • Developing performance metrics and reports to illustrate the status of HCP implementation
  • Working with the HCP team to identify, document, and resolve compliance issues
    • Overseeing the development and delivery of training materials for PG&E staff and contractors to effectively implement this HCP
    • Tracking and recording data to implement the conservation strategy
    • Tracking and recording incidental take information
    • Tracking and recording land acquisitions
    • Maintaining compliance, effects, and effectiveness monitoring and survey data reports

 

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  • Preparing required reports including annual reports
  • Evaluating the effectiveness of the program, including the effectiveness of CMs

Authorized Biologists and Biological Monitors will conduct biological surveys and monitoring when necessary pursuant to the CMs. Biological evaluation, including possible surveys and monitoring, may be necessary for activities where take could occur. As part of the annual report, PG&E will report to the Service all survey results and monitoring detections and provide information on the number and location of covered species it detects during surveys and monitoring activities.

PG&E’s field crews (remediation implementation personnel), including contractor field personnel, will follow the pertinent CMs as directed by Authorized Biologists, Biological Monitors, or the HCP Administrator. Field crews at a covered activity location will work closely with Authorized Biologists and/or Biological Monitors to ensure compliance with CMs during their day-to-day work activities.

2.2.2.4         Monitoring

PG&E will conduct monitoring activities to document compliance with the requirements specified in the HCP and permit (compliance monitoring), track the impacts of the covered activities on the covered species (effects monitoring), and, track the progress of the conservation strategy in meeting the HCP’s biological goals and objectives (effectiveness monitoring).

Compliance Monitoring

Compliance monitoring will address implementation of conservation measures and implementation of compensatory mitigation actions. PG&E will collect information that:

  • Confirms education and training is conducted
  • Shows biological surveys and monitoring are conducted, when necessary
  • Confirms CMs are being implemented
  • Provides an accounting of impacts, including take, and mitigation

Compliance monitoring information will be provided to the Service in the annual report as described on the following paragraphs.

Effects Monitoring

PG&E will verify its impacts, including take, are consistent with the assumptions and impact estimates used in developing the HCP. Impacts resulting from HCP implementation over the permit term will vary from year to year and among phases. PG&E will compare these results with the impact estimates used during HCP development and described in Chapter 4 of this EA. PG&E will use a mitigation accounting reporting system to keep track of all annual impacts, the mitigation required, and the mitigation implemented as part of the conservation strategy. The system will track and deduct “species acre credits” from approved conservation lands. PG&E will use the mitigation tracking system to track all mitigation to ensure that mitigation is completed in advance of covered activity impacts. This effort will help ensure the impacts are accounted for correctly. Effects monitoring information will be summarized in annual reports submitted to the Service.

Effectiveness Monitoring

Effectiveness monitoring is independent of other surveys implemented as conservation measures prior to and during construction, and will be used to determine whether the conservation measures in the HCP are protective of covered species. PG&E will collect, compile, and summarize data from completed covered activities, biological surveys, conservation actions, monitoring reports, and other information to evaluate overall effectiveness of the conservation strategy. Information gathered from these actions will be used to identify problems associated with implementation of species-specific measures and subsequently help the HCP Administrator to develop modifications to existing measures for the purpose

 

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of minimizing habitat disturbance and take of covered species or other ways to make measures more effective and efficient.

The HCP Administrator will also ensure the compensatory mitigation program is effective. The HCP Administrator will ensure that PG&E’s mitigation benefits the covered species. Mitigation actions will include regular management, monitoring, and reporting, and the results of these efforts will be summarized in annual reports submitted to the Service.

2.2.2.5         Reporting

PG&E will meet annually or more frequently with the Service to review progress in implementing the HCP and review the needs for modifications to the HCP due to changed circumstances. PG&E will prepare annual reports to document permit compliance and implementation (effects and effectiveness) of the HCP. Each annual report will summarize the previous calendar year’s activities and will be completed by March 31 of the following year. Annual reports will be submitted to designated representatives of the Service.

The annual report will provide the following information:

  • Provide the necessary information to demonstrate PG&E is implementing the HCP successfully and in compliance with the ITP
  • Document problems with plan implementation that occurred during the reporting year and the steps taken to resolve the problems.
  • Document foreseeable issues with implementation that may require coordination with the Service
  • Provide a summary of the annual training provided to staff and contractors
  • Provide a summary of the CMs implemented and their locations
  • Describe and quantify the covered activities completed and map their locations
  • Quantify and map the land cover types impacted by the covered activity

–         Area of temporary impact by land cover type and quality

–         Area of permanent impact by land cover type and quality

–         Areas of critical habitat, ACEC/TCA lands, tortoise linkage, Mohave ground squirrel linkage, and Mohave ground squirrel expansion area impacted

  • Provide a summary of all take (mortality, injury, translocation, etc.) that occurred during the reporting year, including a description of each incident and location, and an accounting of remaining take authorized, by covered species.
  • Provide a summary of all sightings of covered species and their locations.
  • Document compliance with compensatory mitigation commitments.

–         Total amount of mitigation acreage required from impacts

–         Total acreage of mitigation purchased or otherwise acquired and location where acquired

–         Acreage of mitigation applied to offset covered species impacts during the year

–         End-of-year acreage balance of mitigation remaining

–         Description of PG&E mitigation land-area monitoring completed in reporting year

–         Summary of monitoring and management reports for PG&E habitat acquisitions.

  • Describe any adaptive management measures proposed for the following year for conservation lands.
  • List all amendments or other important decisions made to date, starting with the permit issuance

 

 

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  • Include additional information as agreed to by PG&E and the Service

In addition to the annual compliance and implementation (effects and effectiveness) reporting, annual reports will compile and summarize the following information from previous years, starting from the date the Service approves the HCP and issues the permit. This retrospective analysis will provide a basis for understanding any trends in results using a longer temporal scale. Retrospective information may include the following:

  • Total of temporary impact acreages by habitat quality (high, moderate, or low)
    • Total of permanent impact acreages by habitat quality
  • Total acreages of impacts to critical habitat, ACEC/TCA lands, tortoise linkage, Mohave ground squirrel linkage, and Mohave ground squirrel expansion area lands
  • Total impact acreages combined (temporary and permanent)
  • Overall acreage balance of mitigation remaining
  • Overall remaining take authorization

2.2.2.6         Adaptive Management

The Five-Point Policy (USFWS and NOAA, 2000) describes adaptive management as an integrated method for addressing uncertainty in natural resource management. Adaptive management is necessary because of the degree of uncertainty and natural variability associated with ecosystems and communities and their responses to management during a 50-year permit term. Results of monitoring may also indicate that some management actions are less effective than anticipated. To address these uncertainties, an adaptive management approach will be used to inform PG&E and the Service of changes that may be needed in the management of conservation lands.

Adaptive management measures may be implemented when species or natural-community trends decrease on the conservation lands. In these cases, new or modified measures would be implemented to try and improve the outcome for species and communities. Such measures may could include, but are not limited to, the following:

  • Reduce, increase or otherwise change the pattern of management action
  • Modify approaches to noxious weed and/or predator management
  • Modify species-specific conservation actions based on monitoring results

For the management plan that is prepared for the conservation lands, PG&E will include a contingency of approximately 10 percent of the total endowment to allow the conservation lands manager to complete the following actions:

  • Identify uncertainties and the questions that need to be addressed to resolve uncertainties
  • Develop/implement alternative and experimental management
    • Integrate a monitoring program that can detect the necessary information for conservation strategy evaluation
    • Incorporate feedback loops that link implementation and monitoring to a decision-making process
    • Respond to changed circumstances

Adaptive management actions will likely take place in response to the following:

  • Downward trends in the status of covered species or key natural-community attributes
    • When new information from the literature or other relevant research indicates that a feasible and superior alternative method for achieving the biological goals and objectives exists

 

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  • When monitoring indicates that the expected or desired result of a management action did not occur
  • Change in land use such as evidence of human trespass

2.3                             Alternatives Considered but not Carried Forward

2.3.1                       Other Remediation Approaches Alternative

PG&E’s proposed covered activities are consistent with the Water Board’s CAO (No. R6V-2015-0068), which was adopted on November 4, 2015, for PG&E “to cleanup and abate the effects of the discharge of chromium waste.” The CAO requires PG&E to implement ongoing corrective action, including but not limited agricultural treatment, in situ remediation, and freshwater injection consistent with a series of work plans mutually agreed to by the Water Board and PG&E. These work plans are documented in seven active Water Board orders and notices, which are listed in Attachment 4 of the CAO.

The Service considered expanding the range of alternatives to encompass different remediation approaches – in other words, a changed set of covered activities – but has determined that such alternatives would be infeasible for PG&E given the constraints associated with the CAO. There is an extensive history leading to adoption of the CAO, including a high level of public review, and the Service is recommending that other remediation approaches should not be carried forward for additional study in this document.

2.3.2                       Phased Implementation Alternative

PG&E’s proposed covered activities are consistent with the CAO, which is based in part on monitoring the 3.1 ppb Cr(VI) contour and chromium remediation to 50 ppb and 10 ppb CR(VI) as measured in a subset of monitoring wells. The HCP describes the phased implementation of the covered activities as follows (see HCP Section 2.2.4, for more information):

  • Phase 1 includes construction of new in situ treatment facilities in the in situ reactive zone of OU1
  • Phase 2 includes construction of AT facilities in OU1 and OU2
  • Phase 3 includes construction of additional AT facilities in OU1 and OU2
  • Phase 4 includes full buildout of all facilities in all operable units

At this time, compliance with the CAO may involve buildout of all covered activities through Phase 4. However, the HCP describes the phased approach in part to account for changing site and regulatory conditions. For example, the U.S. Geological Survey (USGS) is conducting a background study of hexavalent chromium concentrations, and it is possible that the results of this study could change the remediation targets in the CAO such that Phases 2 to 4 are not needed. Based on this possibility, the Service considered alternatives using this phased implementation approach – each phase would be identified as a unique NEPA alternative. This approach could allow greater flexibility to adopt the alternative that most accurately reflects the covered activities at the time the Service makes its final permit issuance decision.

Upon further consideration, the Service is no longer considering this approach. At this time, USGS’s background study is expected to be completed after the Service’s permit decision. In that case, adoption of an alternative that does not include all (i.e., Phases 1 through 4) covered activities could be inconsistent with the CAO requirements. For this reason, the Service has determined that phased implementation alternatives should not be carried forward for additional study in this document.

 

 

 

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2.3.3                       Incidental Take Permit Term Alternative

The Service commonly considers variations on the permit term (longer or shorter than proposed) as feasible alternatives, provided there is a good reason. The proposed action includes PG&E’s request for a 50-year incidental take permit. As explained in the HCP (Section 1.6), PG&E and the Water Board estimate that monitoring and remediation of contaminated groundwater at Hinkley will require up to 50 years. A 50-year permit term is proposed to allow sufficient time to implement all the anticipated work plan items required by the CAO. For this reason, a shorter permit term does not appear to be a feasible option as it may result in PG&E not being able to meet the requirements of the CAO, and a longer permit term is not necessary given those same requirements. The Service has determined that a permit term alternative should not be carried forward for additional study in this document.

2.3.4                       Additional Species Alternative

The Service is considering an ITP application covering desert tortoise and Mohave ground squirrel, but other special-status species occur in the project area and could be considered for coverage. Although it is the applicant’s responsibility to select species for coverage in an ITP application, the Service considers the addition (or, in some cases, subtraction) of species in developing a range of alternatives. Whether or not to carry forward an additional species alternative depends on several factors including the rarity of the other species, the sufficiency of available information, and the possibility that the other species may benefit from coverage.

The HCP explains PG&E’s reasons for selecting the desert tortoise and Mohave ground squirrel for coverage (Section 3.7) and also describes why PG&E did not select other species for coverage (Section 3.8). The Service further reviewed the potential for the covered activities to cause adverse or beneficial effects on other species, and determined that either there is little to no effect or that any

potential effects are adequately addressed through other regulatory mechanisms. For example, PG&E implements a Burrowing Owl Management Plan consistent with mitigation measure BIO-MM-1l of the Water Board’s FEIR (2013). Covered activity impacts to biological resources are discussed in Section 4.3 of this EA.

Additional information about special-status species impacts is presented in this document in Section 3.1, Issues and Concerns, and throughout Chapter 4, Biological Resources. Because of the limited potential for additional adverse impacts and the benefits from other, existing regulatory mechanisms, the Service has determined that an additional species alternative does not need to be carried forward for additional study in this document.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Approach to the Analysis

3.1                             Issues and Concerns

The following listed issues were identified using federal laws, regulations, executive orders, agency management policies, and our knowledge of limited or easily impacted resources. In particular, NEPA calls for an examination of potential impacts on all components of the human environment. Based on a review of the potential impacts of the proposed action on the human environment, the Service determined that several issues should be analyzed in detail in the decision-making process for this EA to help compare the impacts of the alternatives. Other issues were evaluated, but based on review by the Service do not require detailed analysis. The following is a brief discussion of why certain issues were selected for further analysis and why others were dismissed from further consideration.

3.1.1                       Impacts Discussed in this EA

Environmental resources of concern that are addressed in this EA are briefly discussed in the following paragraphs, and analyzed in detail in the following chapters.

Impacts on Vegetation Communities. The alternatives are expected to result in changes to land cover, including some changes that could affect natural vegetation communities such as conversion of desert scrub into an ATU. The Service seeks to protect the natural abundance and diversity of natural communities, and therefore impacts on vegetation communities are addressed as an impact topic in this document. Furthermore, understanding changes in vegetation communities helps to determine the potential for impacts to the covered species, and to other plant and animal species.

Impacts on Covered Species: Desert Tortoise and Mohave Ground Squirrel. The alternatives include issuance of an ITP for desert tortoise and Mohave ground squirrel, and therefore impacts to these species are addressed as an impact topic in this document. All potential impact mechanisms are considered, including mortality, habitat loss (including critical habitat), changes in movement patterns, environmental toxicity, pesticide use, predation, and invasive species.

Impacts on Other Species. Implementation of the proposed action may have unintended consequences (adverse and beneficial impacts) to other species. The impact mechanisms by which other species could be affected are addressed in this document. Based on Service review, the other species that could be affected are migratory birds, including burrowing owls, bald and golden eagles, and potentially other migratory bird species. Because no impact mechanisms are apparent that would adversely affect other species, the Service will limit its analysis to migratory birds. Additional discussion of species not considered in detail is provided below.

Impacts on Water Quality. The alternatives would reduce chromium contamination in the groundwater aquifer relative to existing conditions, which would be a beneficial effect on the environment. The Water Board studied several potential adverse water quality impacts that could result from chromium remediation. In many cases, the Water Board determined that other potential types of groundwater quality impacts would be less than significant. The Water Board did, however, determine that there may be temporary, localized impacts associated with chromium plume spreading (or “bulging”) that would occur during remediation. The Water Board also studied water quality changes associated with remediation activities, and determined that there could be increased concentrations of other constituents such as total dissolved solids, uranium, and secondary byproducts of remediation. For these reasons, the potential for the alternatives to affect water quality is addressed as an impact topic in this document.

 

 

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Impacts on Archaeological and Historic Architectural Resources. The alternatives include various demolition and land-disturbing activities, which may affect historic properties, and surficial or subsurface archaeological resources or human remains. Therefore, impacts on cultural resources are addressed as an impact topic in this document.

Impacts on Minority and Low-Income Communities. The alternatives would affect the amount of money that would be spent in the area, thereby adding to or subtracting from the plan area economy. In addition, the alternatives involve the direct purchase of residences and business within the plan area.

The potential for these activities to affect minority and low-income communities is addressed as an impact topic in this document.

3.1.2                       Impacts Not Discussed with Rationale

The issues that were not analyzed were identified, and a discussion on why their analysis is not necessary is provided below. In many cases, the discussion references the analysis and mitigation measures (MMs) found in the Water Board’s FEIR (2013).

Impacts on Aesthetics and Visual Resources. Under both alternatives, potential visual impacts to sensitive receptors – primarily nearby residents – would be minor and temporary during all covered activity construction. Most long-term impacts would not be significant. For example, ATUs would be at- grade agricultural fields consistent with existing local farmland areas, and aboveground facilities such as in situ remediation and agricultural treatment wells would be very small and widely distributed throughout the area. Ex situ treatment facilities would be constructed under Alternative 2, and these larger structures have a greater potential for visual impacts. In implementing the covered activities consistent with the Water Board’s FEIR (2013), PG&E has committed to three MMs to reduce the potential for visual impacts associated with ex situ treatment facilities: MM MAES-MM-1 (landscaping and/or visual screening), MM AES-MM-2 (low-sheen and nonreflective surfaces), and MM AES-MM-3 (light reduction measures). Implementation of the covered activities as directed by the Water Board would ensure that aesthetic and visual resource impacts are not significant, and no further analysis is needed.

Impacts on Agricultural Lands. All alternatives would maintain or increase agricultural activity with the use of ATUs, including up to 1,088 acres of new agricultural areas in addition to existing farmland and grazing land. The alternatives would support continued agricultural uses in the Hinkley area, including new areas of feed crop (e.g., alfalfa) production under Alternative 2. Some localized farmland impacts would occur under all alternatives, for example from construction in situ remediation and agricultural treatment wells. Although the overall net change in agricultural acreage would likely be positive, the covered activities may contribute to groundwater drawdown or changes in groundwater quality. These activities may contribute to the indirect loss of farmlands in the area. PG&E has committed to mitigating groundwater drawdown impacts by securing alternative water supplies if groundwater drawdown were to affect agricultural wells. This commitment (MM WTR-MM-2) would prevent substantial disruption to existing agricultural activities. Similarly, MM LU-MM-2 requires that PG&E either avoid acquiring water rights from existing agricultural users or acquire and record an agricultural conservation easement on farmlands from which it acquires water rights for remedial purposes (Water Board, 2013). This would mitigate the potential adverse farmland impacts associated with PG&E’s required acquisition of water rights from existing agricultural landowners. Implementation of the covered activities as directed by the Water Board would ensure that agricultural land impacts are not significant, and no further analysis is needed.

Impacts on Air Quality and Climate Change. The covered activities would be consistent with air quality and greenhouse gas reduction strategies including the Federal 8-Hour Ozone Attainment Plan for the Western Mojave Planning Area (MDAQMD, 2008), the Mojave Desert Planning Area Federal Particulate Matter (PM10) Attainment Plan (MDAQMD, 1995), and the San Bernardino County Greenhouse Gas

 

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Reduction Plan (ICF International, 2014). Implementation of the covered activities under all alternatives would result in a temporary increase in criteria pollutant and greenhouses gas emissions during construction. All construction activities would employ routine pollution control measures pursuant to Mojave Desert Air Quality Management District (MDAQMD) Rule 403.2, Fugitive Dust Control, and similar rules. PG&E also would implement MMs AIR-MM-1 (clean diesel construction equipment), AIR- MM-2 (delivery and haul truck fleet modernization), and AIR-MM-3 (construction emission reduction measures). Potential risks from toxic air contaminants would not be significant because of the highly dispersed nature and short duration of construction activities, as well as through use of vehicle emissions reduction measures prescribed in the Water Board’s FEIR (2013). In addition, PG&E would implement measures pursuant to the San Bernardino County Greenhouse Gas Reduction Plan including standard for construction (MM AIR-MM-6), facilities operation (MM AIR-MM-7), and for facility design (MM AIR-MM-8). Implementation of the covered activities pursuant to regulatory standards and as directed by the Water Board would not result in a significant impact to air quality or greenhouse gases, and no further analysis is needed.

Impacts on Biological Resources. Impacts to key biological resources – vegetation communities, covered species, and certain other species – are considered in detail in this EA as described above. In deciding to focus on those resources, the Service also considered other subcategories of biological resources and determined that detailed analysis was not needed. These other biological resources include the following.

  • Impacts to waters of the United States, including wetlands, are unlikely to occur due to the general lack of wetlands and other waters in the plan area. If it is determined that impacts would occur in some areas, the Water Board is requiring PG&E to mitigate these impacts (both temporary and permanent) at a 3:1 ratio and to the satisfaction of CDFW.
  • There are no sensitive riparian habitats that would be affected by the project.
    • A database search for special-status plant species showed the potential for 34 species to occur in the plan area. Of these, 17 species were considered to have moderate to high potential to occur in the plan area; none of these species is federally or state-listed. Further analysis showed that these species are not likely to be present, not likely to be adversely affected, or have uncertain status and/or rarity. In addition, the Water Board has required that PG&E conduct pre-activity plant surveys (MM BIO-MM-1o), which helps to avoid or minimize the potential for impacts to these species. Additional information about these species is presented in the HCP (Section 3.7.3).
    • Similarly, a database search for special-status wildlife species showed the potential for the following species to occur in the plan area. Additional information about these species is presented in the HCP (Section 3.7.3).

-        Mojave fringe-toed lizards are known to occur near the Mojave River in the southern portion of the plan area, where sand dunes are present. Under all alternatives, the covered activities would not affect sand dunes, and therefore there would be no impacts to Mojave fringe-toed lizards.

-        Mojave River voles are found within moist habitats near the Mojave River. The Water Board determined that an increase in ATUs in the southern portion of the project area could benefit this species, and would not have significant adverse impacts.

-        American badgers and desert kit foxes have a moderate to high potential to occur within the plan area. The Water Board evaluated potential impacts to these species, and determined that impacts would be less than significant with implementation of mitigation measures (MMs BIO- MM-1b through 1e, BIO-MM-1i through 1j, and BIO-MM-1m).

 

 

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  • Some protected trees – primarily Joshua trees – could be removed during construction. If construction requires the removal of Joshua trees or other protected trees, PG&E would be required to comply with the San Bernardino County Plant Protection and Management Ordinance. This would help to avoid or minimize the potential impacts to these species.

For these reasons, implementation of the covered activities would not result in significant impacts to these other subcategories of biological resources, and no further analysis is needed.

Impacts on Geology and Soils. Construction associated with the covered activities could result in the potential for erosion and the loss of topsoil, but PG&E would undertake all activities pursuant to the San Bernardino County Revised Erosion and Sediment Control Ordinance as well as MDAQMD dust control regulations. In addition, installation of ATUs is expected to provide cover crops with subsurface root complexes that provide for soil stabilization. Studies by the Water Board indicate limited potential for ground subsidence from groundwater pumping, and limited potential for impact from seismic activity. For these reasons, implementation of the covered activities would not result in significant geology and soils impacts, and no further analysis is needed.

Impacts on Hazards and Hazardous Materials. During the construction and operation of the covered activities under all alternatives, there is a potential for disturbance of soils that could contain existing hazardous substances. This disturbance could result in the exposure of hazardous substances to construction workers, nearby residents, and the environment in general. PG&E would undertake all activities consistent with existing federal, state, and local requirements including federal and Division of Occupational Safety and Health of California worker safety protections, and California Environmental Protection Agency and local business plan requirements for use and storage of hazardous materials (Unified Program). In addition, PG&E has committed to implementing Water Board MMs HAZ-MM-1 (onsite inspections during soil excavation), HAZ-MM-2 (Spill Prevention, Control, and Countermeasure Plan), and HAZ-MM-3 (hazardous building materials survey). For these reasons, the potential impacts from hazards and hazardous materials would not be significant, and no further analysis is needed.

Impacts on Hydrology and Floodplains. The plan area is flat, and not generally subject to surface drainage and floodplain impacts. Covered activity facilities constructed under all alternatives would be very small and widely distributed throughout the area, with no potential for large areas of new impervious surfaces and with only minor, localized changes in surface drainage. None of these areas are designated by the Federal Emergency Management Agency as special flood hazard areas.

All alternatives include use of groundwater. Covered activities such as operation of ATUs could result in groundwater drawdown, with associated impacts on water supplies. The local groundwater basin has been adjudicated, meaning that water users are allocated a fixed amount of water per year. As an existing groundwater water user, PG&E has an annual allocation currently totaling 2,526 acre-feet per year. Total groundwater pumping with implementation of the covered activities may exceed the current allocation. The Water Board recognized this potential impact in its FEIR, and is requiring PG&E to demonstrate that it has acquired the necessary water rights before fully implementing its remediation activities (MM WTR-MM-1). The Water Board also studied the potential for local groundwater drawdown to affect small domestic groundwater users. Although there is some uncertainty regarding the extent and duration of potential impacts, the Water Board required PG&E to provide alternative water supplies for users who are substantially affected (MM WTR-MM-2). The Water Board examined the availability of nearby water sources and determined that implementing MMs WTR-MM-1 and WTR- MM-2 was feasible, and the impacts would be less than significant.

Implementation of the covered activities as directed by the Water Board would ensure that hydrology and floodplain impacts are not significant, and no further analysis is needed.

Impacts on Land Uses and Land Use Compatibility. The primary land use change associated with the proposed action is the development of additional ATUs (up to an additional 1,088 acres). Because of the

 

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agricultural history of the plan area, the increase in ATUs would be a normal and expected land use activity and would not introduce new land uses that would be incompatible with the Hinkley area. Other covered activities, such as the installation of new in situ remediation and agricultural treatment wells, would be small, self-contained, and widely distributed throughout the area. Covered activities may contribute to groundwater drawdown, which could disrupt domestic water supplies. PG&E has committed to mitigating groundwater drawdown impacts by securing alternative water supplies (FEIR MM WTR-MM-2), which would mitigate potential land use disruptions.

Land use compatibility also could be affected by covered activities that increase traffic, noise, and similar actions that may be perceived as nuisances. These types of issues have been addressed in the Water Board’s FEIR (2013), and as a result PG&E has committed to implementing requirements such as preparing and following a noise control plan and using construction practices that reduce noise levels (MM NOI-MM-1), and reducing the potential for traffic congestion and roadway hazards by implementing traffic control measures during construction (MM TRA-MM-1).

Implementation of the covered activities as directed by the Water Board would ensure that land use impacts are not significant, and no further analysis is needed.

Impacts on Land Use Plans and Policies. Implementation of the covered activities under all alternatives would be consistent with the San Bernardino County General Plan and zoning ordinance. Most activities would occur on lands designated as Agricultural or as Rural Living. ATUs, in situ treatment facilities, and ancillary uses (e.g., access roads) are consistent with both the Agricultural and Rural Living districts. Ex situ treatment facilities, which would be constructed under Alternative 2, may be considered industrial facilities, and therefore not compatible with the Agricultural or Rural Living zones. If these facilities are proposed for development, then PG&E would work with San Bernardino County to adopt a conditional or special use permit or, if necessary, to process a General Plan Amendment. Given the processes available to bring the ex situ treatment facilities into compliance with San Bernardino County requirements, the potential inconsistency would not be a significant impact, and no further analysis is needed.

Growth Inducement. NEPA requires consideration of indirect impacts of an action, including growth- inducement impacts. The proposed action would not have any direct growth-inducing impacts because no development would be specifically authorized in the plan area. The covered activities would remediate contaminated groundwater in the plan area to meet public health goals.

Irreversible and Irretrievable Commitment of Resources. Construction and operation of the various facilities planned to be implemented under all alternatives would result in an irreversible and irretrievable commitment of natural resources through the use of power supply and construction materials. The covered activities will require the use of petroleum products, primarily in the form of gasoline, diesel, and motor oil, for a variety of construction activities including excavation, grading, and vehicle travel onsite and between sites. Construction of wells and aboveground treatment facilities would commit resources such as concrete and steel. Covered activity operation would require additional energy consumption provided by Southern California Edison and generated in large part by fossil fuels. This proposed commitment of natural resources is typical of the types of activities under consideration, necessary to implement the required remediation activities, and therefore would not be a significant impact. No further analysis is needed.

Short-Term Uses of the Environment versus Maintenance and Enhancement of Long-Term Productivity. In accordance with NEPA, Section 102 (40 United States Code [U.S.C.] 4332), an EA must include a discussion between the short-term uses of the environment with the maintenance and enhancement of long-term productivity. Short-term impacts of the alternatives are associated with construction and remediation activities, and are described in Chapters 4 through 7. Specific resources that could be affected by construction and remediation activities include biological resources, water quality, and cultural resources.

 

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The action alternatives would not detract from long-term environmental productivity. Although some activities from the HCP under Alternative 2 would result some temporary and permanent loss of habitat as well as incidental take of some sensitive species, these activities would be undertaken in accordance with a comprehensive mechanism to avoid, minimize, and mitigate for impacts to covered species and their habitats.

3.2                             Cumulative Impacts

This section of this EA lists projects that may contribute to cumulative impacts of the proposed action in the context of other “past, present, and reasonably foreseeable” actions in the Hinkley area. Cumulative impacts can result from individually minor but collectively significant actions taking place over a period of time. For this EA, the cumulative impact analysis considers reasonably foreseeable actions within an assessment area defined as the plan area and a 20-mile buffer around the plan area. This assessment area is sufficiently sized to contain all potential indirect effects to desert tortoise and Mohave ground squirrel. Past, present, and reasonably foreseeable future projects that could result in environmental impacts that could combine with impacts from the alternatives to result in cumulative impacts are identified below.

  • State Route 58 Hinkley Expressway Project. The California Department of Transportation (Caltrans) SR 58 Hinkley Expressway Project widened and realigned an existing 9.3-mile segment of SR 58 from two lanes to four lanes. The new roadway no longer has at-grade intersections with local roads, and includes new interchanges at Hinkley Road and Lenwood Road. Most of the project is within the plan area, and all the project is within the cumulative impacts assessment area. The project’s Environmental Impact Report/Environmental Impact Statement (Caltrans, 2013) was approved by Caltrans on June 27, 2013, and was completed in early 2017.
  • Solar Projects. There are three pending solar development projects within the cumulative impacts assessment area (none are within the plan area).

-        Boulevard Associates has proposed a 20-megawatt facility on 191 acres on the west side of SR 395, about 2.5 miles north of SR 58. This project has been conditionally approved by San

Bernardino County. No permits have been issued, but an extension of time has been approved (San Bernardino County, 2016).

-        Lightsource Renewables has proposed a 40-megawatt facility on 350 acres on the south side of SR 58, about 1.5 miles west of SR 395. This project has been conditionally approved by San Bernardino County. However, no permits have been issued and the application has expired (San Bernardino County, 2016).

-        The Longboat Solar project is a 20-megawatt facility on 233 acres located to the northwest of the City of Barstow and bound by SR 58 to the east and north. Construction is complete (San Bernardino County, 2016).

  • San Bernardino County General Plan Buildout. Hinkley is located within unincorporated San Bernardino County, and subject to the land use restrictions of the San Bernardino County General Plan (San Bernardino County, 2007). The General Plan contains the goals, policies, and implementing actions for a variety of issues and sets the framework for decision-making regarding the County’s long-term development and use of resources. The General Plan allows for long-term growth within the unincorporated county areas as allowed by the plan designations, zoning and requirement. Most of the cumulative impact assessment area is designated as Rural Living, Agriculture, or Resource Conservation.

-        Rural Living zones are generally limited to very low density single family residential development, with lot size limitations ranging from 5 to 40 acres.

 

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-        Agriculture zones are intended to protect and support commercial agricultural uses, with minimum lot sizes ranging from 20 to 160 acres.

-        Resource Conservation zones focus on preserving open space, watershed, and wildlife habitat areas with very limited rural development.

  • Barstow General Plan Buildout. The Barstow General Plan is the overarching guide in implementing the city’s development code, which defines development regulations and establishes zoning districts throughout the incorporated City of Barstow (City of Barstow, 2016). Goals and policies included in the Barstow General Plan serve as guidelines for future development of the city, allocation of public services, and other factors of importance to the city. Although most of Barstow is located several miles west of the plan area, the cumulative impact assessment area includes most of the incorporated city.

The analysis of cumulative impacts occurs in the individual resource sections of this document (Chapters 4 through 7). Cumulative impacts were analyzed in accordance with the NEPA (42 U.S.C. 4321–4347), Council on Environmental Quality (CEQ) regulations (40 CFR Parts 1500–1508), and CEQ Guidelines for conducting cumulative impact analysis.

 

CHAPTER 4

Biological Resources

4.1                             Regulatory Setting

4.1.1                       Federal Endangered Species Act

The ESA was enacted in 1973 to protect and recover imperiled species and their ecosystems. The following three sections of the ESA are relevant to the HCP:

  • Section 7 requires that federal agencies consult with the Service or NMFS to ensure that their actions are not likely to jeopardize the continued existence of listed species and are not likely to result in the destruction or adverse modification of designated critical habitat for listed species.
  • Section 9 prohibits, among other things, the take of listed fish and wildlife species.
    • Section 10(a)(1)(B) permits the take of listed fish and wildlife species incidental to otherwise lawful activities.

Section 10(a)(1)(B) of the ESA establishes a process for obtaining an ITP, which authorizes nonfederal entities to incidentally take federally listed wildlife or fish subject to certain conditions. Incidental take is defined by the ESA as “take that is incidental to, and not the purpose of, the carrying out of an otherwise lawful activity.” Preparation of a habitat conservation plan, generally referred to as an HCP, is required for all Section 10(a)(1)(B) permit applications. The Service has authority under the ESA for administering HCPs and ITPs for federally listed species and unlisted covered species.

An HCP submitted in support of an ITP application must include the following information:

  • Impacts likely to result from the proposed taking of the species for which permit coverage is requested
  • Measures that will be implemented to monitor, minimize, and mitigate impacts and funding assurances to undertake such measures
  • Alternative actions considered that will reduce or avoid take
    • Additional measures that the Service may require as necessary or appropriate for purposes of the HCP

A Section 10 ITP is issued upon a determination by the Service that all permit requirements have been met. In making an affirmative determination, the Service must meet statutory criteria for issuing an ITP, which require preparation of an HCP that specifies the following:

  • Take will be incidental
  • Impacts of incidental take will be minimized and mitigated to the maximum extent practicable
  • The applicant will ensure that adequate funding for the HCP will be provided
  • Take will not appreciably reduce the likelihood of survival and recovery of the species in the wild
    • The applicant will provide additional measures that the Service requires as being necessary or appropriate
    • The Service has received assurances, as may be required, that the HCP will be implemented

The No Surprises Rule (63 CFR 8859) provides regulatory assurances to the holder of an ITP issued under the ESA that no additional restrictions or compensation will be required with respect to covered species

 

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beyond the requirements in the ITP. That is, if unforeseen circumstances indicate the need for additional mitigation, the Service cannot change the terms of the HCP if the permit holder is implementing the HCP properly and in good faith.

4.1.2                       Migratory Bird Treaty Act

The Migratory Bird Treaty Act (MBTA) implements a series of international treaties that provides migratory bird protection. The MBTA authorizes the Secretary of the Interior to regulate the taking of migratory birds, and the act provides that it is unlawful, except as permitted by regulations, “to pursue, take, or kill any migratory bird, or any part, nest or egg of any such bird” (16 U.S.C. Section 703). PG&E has provided species-specific buffers to avoid and minimize impacts to nesting bird species protected under the MBTA in the plan area (Appendix A).

4.1.3                       Bald and Golden Eagle Protection Act

This law prohibits, except under specified conditions, the taking, possession, and commerce of bald and golden eagles. The Bald and Golden Eagle Protection Act (BGEPA) defines take as to “pursue, shoot, shoot at, poison, wound, kill, capture, trap, collect, molest or disturb” (16 U.S.C. 668–668d). “Disturb” is defined in 50 CFR 22.3 as: “to agitate or bother a bald or golden eagle to a degree that causes, or is likely to cause, based on the best scientific information available, 1) injury to an eagle, 2) a decrease in its productivity, by substantially interfering with normal breeding, feeding, or sheltering behavior, or 3) nest abandonment, by substantially interfering with normal breeding, feeding, or sheltering behavior.” In addition to immediate impacts, this definition also covers impacts that result from human-caused alterations initiated around a previously used nest site during a time when eagles are not present, if, upon the eagle’s return, such alterations agitate or bother an eagle to a degree that injures an eagle or substantially interferes with normal breeding, feeding, or sheltering habits and causes, or is likely to cause, a loss of productivity or nest abandonment.

The Service finalized regulations to authorize the take of bald and golden eagles under the BGEPA, when the take to be authorized is associated with otherwise lawful activities (USFWS, 2008a). PG&E has provided species-specific buffers to avoid and minimize impacts to nesting bird species protected under the BGEPA in the plan area (Appendix A).

4.1.4                       California Endangered Species Act

Section 2080 of the California Endangered Species Act (CESA) prohibits the take of any species that the California Fish and Game Commission determines to be a candidate species, endangered species or a threatened species. Take is defined in Section 86 of the Fish and Game Code as to “hunt, pursue, catch, capture, or kill, or attempt to hunt, pursue, catch, capture, or kill.” CESA authorizes CDFW to issue permits to allow for take incidental to otherwise lawful activities. Desert tortoise and Mohave ground squirrel are subject to the provisions of CESA.

4.1.5                       California Fish and Game Code

Sections 3505, 3511, 3513, 3800, 4700, 5050, and 5515 of the California Fish and Game Code pertain to fully protected wildlife species and strictly prohibit the take of fully protected species. With certain exceptions, CDFW cannot issue a take permit for fully protected species and avoidance measures are typically implemented to avoid take. Of the 37 recognized fully protected species, only the golden eagle has the potential to occur within the plan area.

Section 3503 of the California Fish and Code protects nesting birds and their active nests, and overlaps with several provisions of the MBTA. This section makes it “unlawful to take, possess, or needlessly destroy the nest or eggs of any bird…” Section 3503.5 specifically focuses this restriction on birds of prey, although all nesting bird species (native or non-native) are covered by Section 3503.

 

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4.2                             Affected Environment

4.2.1                       Background

As described in Chapter 2, the plan area consists of the approximately 30,000 acres within which PG&E is proposing to conduct groundwater remediation activities (Figure 2-1). The Hinkley Valley is bounded generally by Lynx Cat Mountain to the west and northwest, by Mount General to the east, by Iron Mountain to the southwest, and by Black Mountain and Opal Mountain to the north. Because of its valley location, the plan area is relatively flat, ranging in elevation from 2,100 to 2,300 feet above sea level. Mount General and Iron Mountain rise to 2,925 feet and 3,065 feet above sea level, respectively. The Mojave River is along the southern boundary of the plan area, flowing northeasterly from the San Bernardino Mountains. Surface flow within the Mojave River is typically ephemeral and associated with heavy seasonal rainfall events. However, the region is considered arid, with nearby Barstow averaging just over 4 inches of rainfall annually. Maximum air temperatures in Barstow (averaged by month) range from around 60.5 degrees Fahrenheit (°F) in January to 102°F in July, with minimum temperatures ranging from 33.5°F in December to 69.3°F in July (Western Regional Climate Center, 2017). Soils within the plan area are variable, but generally include sands, loamy sands, and loams (Water Board, 2013).

Small areas of rock outcrop are also present in the northern portion of the plan area.

4.2.2                       Land Cover Types

PG&E identified and quantified undeveloped and developed land cover types within the plan area by delineating land covers using satellite imagery and ground-truthing during site survey efforts targeting desert tortoise (SBI, 2013). Approximately 73 percent of the plan area is undeveloped and vegetated with natural plant communities, with the remaining 27 percent of the plan area developed or showing signs of past development. Undeveloped land cover types include creosote-bursage desert scrub, desert dunes, desert wash, alkali playa and edge, grasslands, and saltbush desert scrub land cover types.

Developed land cover types include active agriculture, urban/developed, and disturbed areas. Detailed descriptions of these land cover types and vegetation associations are in Chapter 3 of the HCP.

4.2.3                       Wildlife

Wildlife in the plan area are representative of a typical Mojave Desert faunal community influenced by adjacent residential and agricultural development. Appendix D of the HCP includes a list of wildlife species observed by biologists who have monitored PG&E remediation activities in the plan area.

Sensitive species potentially affected by the proposed action are desert tortoise, Mohave ground squirrel, burrowing owl, bald and golden eagles, and other migratory birds. These species are described below and additional information can be found in the Chapter 3 of the HCP.

4.2.3.1         Desert Tortoise

Management of desert tortoises under the authority of the ESA is performed at several spatial scales. The following summary is provided to assist readers in understanding these scales.

  • Species-level Scale.Tortoises found within the Hinkley project site are classified asGopherus agassizii. Common names for this species have varied through time and have included Agassiz’s desert tortoise, desert tortoise, and Mojave population of desert tortoise. Within this document, we have used “desert tortoise” to refer to the listed taxonG. agassizii.
    • Recovery Unit-level Scale. Five recovery units are established for the desert tortoise. The plan area is located entirely within the WMRU.
    • Critical Habitat Unit-level Scale: Sixteen CHUs are established for desert tortoise, with three of these intersecting the WMRU. The plan area covers approximately 2,315 acres of the Superior-

 

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Cronese CHU, which is also designated as the Superior-Cronese ACEC by the BLM. ACECs are public lands where special management is required to protect an area’s natural or historic values, or to protect the public from hazards that may pose a threat to human life or safety, or to property

(43 CFR 1610.7-2).

Information on desert tortoise presence within the plan area is based on recent protocol-level surveys (SBI, 2013). The surveys found that live desert tortoises were more abundant within natural areas (0.0018 tortoise/acre) than disturbed areas (0.0005 tortoise/acre), and live desert tortoises were more abundant within disturbed areas than within urban or agricultural areas (no tortoises). This pattern of tortoise density was evident within OU2 and OU3. No desert tortoises were detected in OU1 (SBI 2013).

Based on these investigations, PG&E estimates that the plan area supports 860 desert tortoises (HCP Table 3-4).

In natural areas, live desert tortoises were more commonly associated with the following land cover types: desert wash (0.0032 tortoise/acre), creosote-bursage desert scrub (0.0021 tortoise/acre), saltbush desert scrub (0.0019 tortoise/acre), and alkali playa and edge (0.0013 tortoise/acre). Live tortoises were not detected in association with desert dunes or grasslands habitats (SBI, 2013).

Like live desert tortoises, tortoise burrows were more abundant within natural areas

(0.0058 burrow/acre) than disturbed areas (0.0010 burrow/acre), and burrows were more abundant within disturbed areas than within urban or agricultural areas (0.0007 burrow/acre). Tortoise burrows were distributed somewhat differently than live tortoises in natural areas: burrows were found mostly in association with grasslands (0.0153 tortoise/acre), creosote-bursage desert scrub (0.0080 tortoise/acre), saltbush desert scrub (0.0052 tortoise/acre), desert wash (0.0048 tortoise/acre), desert dunes

(0.0023 tortoise/acre), and alkali playa and edge (0.0007 tortoise/acre). Desert tortoise burrows were detected in OU2 and OU3, but not in OU1 (SBI, 2013).

In addition to its comprehensive survey of the plan area, PG&E has conducted pre-activity surveys and biological monitoring for desert tortoises in advance of and during ground-disturbing activities. As of January 1, 2016, 46 live desert tortoises, 14 desert tortoise burrows, and 10 desert tortoise carcasses were recorded in association with this monitoring effort (HCP Appendix E; Shrum, 2016; Breakiron, 2016). Live desert tortoises were observed in OU3 (n=35), OU2 (n=6), and OU1 (n=5), but live desert tortoises were only detected in OU1 in 2011. Some desert tortoises observed through time may have been the same individuals, so observations cannot be interpreted as absolute or relative abundances. Rather, these results are intended to supplement the distribution and abundance results from protocol survey efforts (SBI, 2013), and indicate that live desert tortoises occur throughout the plan area.

4.2.3.2         Mohave Ground Squirrel

Information on Mohave ground squirrel presence within the plan area is based on recent protocol-level surveys (Vanherweg, 2012, 2013). However, presence information in the plan area is complicated by the co-occurrence of another closely related species of ground squirrel, the round-tailed ground squirrel (Xerospermophilus tereticaudus), which can be difficult to distinguish from the Mohave ground squirrel. These two species can hybridize, further complicating definitive identification. In 2012, 4 Xerospermophilus spp., a term denoting uncertainty regarding identification, were captured at 4 of the 11 trapping grids. All four appeared to be typical of round-tailed ground squirrel. In 2013, 11 Xerospermophilus spp. were captured at 5 of the 15 trapping grids. None of the Xerospermophilus spp. trapped in 2013 displayed characteristics typical of Mohave ground squirrel. All weights of captured Xerospermophilus spp. were consistent with those expected of round-tailed ground squirrel, and all trapped Xerospermophilus spp. exhibited round-tailed ground squirrel vocalizations while in traps.

However, 4 of the 11 Xerospermophilus spp. trapped in 2013 displayed phenotypes (external appearances) suggesting potential hybridization between Mohave ground squirrel and round-tailed ground squirrel.

 

 

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In addition to the protocol surveys, tissue samples were collected and analyzed from the 15 Xerospermophilus spp. individuals trapped in the plan area in 2012 and 2013 to determine their genetic identifications (i.e., Mohave ground squirrel, round-tailed ground squirrel, or hybrid). While no genetically pure Mohave ground squirrels were identified among the samples tested, two round- tailed/Mohave ground squirrel hybrids were identified. The other 13 individuals analyzed from the trapped portion of the plan area were shown to be genetically pure round-tailed ground squirrels (Leitner and Matocq, 2015).

Leitner and Matocq (2015) also discussed that genetically pure Mohave ground squirrels were most frequently associated with undisturbed desert land cover types, while round-tailed ground squirrels were most frequently associated with developed land cover types such as agricultural fields. They suggested that the relative abundance of agricultural fields in the southern portions of the plan area likely explained the absence of Mohave ground squirrels and presence of round-tailed ground squirrels in this region. Leitner and Matocq (2015) concluded that the occurrence of Mohave ground squirrel/round-tailed ground squirrel hybrids in the plan area suggests the presence of genetically pure Mohave ground squirrels in portions of the plan area not dominated by agricultural land use.

4.2.3.3         Burrowing Owl

Burrowing owls have the potential to use the plan area for foraging and nesting, and to use existing burrows excavated by ground squirrels, badgers and desert tortoises. Burrowing owls may also nest within or immediately adjacent to the agricultural areas. Burrowing owls are found year-round in old piping at long-abandoned agricultural units. Burrowing owls are also found scattered throughout the plan area near active agriculture, on residential properties, and in desert areas (Transcon, 2013). The California Natural Diversity Database (CDFW, 2016) also reports occurrences of this species in the vicinity of the plan area.

4.2.3.4         BGEPA-Protected Species

Golden eagles have been observed on occasion in the plan area and were recorded during biological surveys associated with the HCP (SBI, 2013), and during biological monitoring associated with PG&E remediation activities (Transcon, 2013). Suitable nesting habitat for golden eagles does not occur in most of the plan area, but may occur in association with the rocky slopes of Mount General near the eastern margin of the plan area. Currently there are no records of nesting golden eagles in the plan area. Golden eagles may forage in the plan area, but foraging has not been observed.

Bald eagles are known to occur at the Harper Dry Lake Marsh, northwest of the plan area (BLM, 2014), but have not been recorded in the plan area (Transcon, 2013). Bald eagles typically nest in tall trees within 2 kilometers of water, and forage on fish (Buehler, 2000). Suitable nesting and foraging habitat for bald eagles does not occur in the plan area.

4.2.3.5         MBTA-Protected Species

The current list of species protected by the MBTA was published in the November 1, 2013, edition of the CFR (USFWS, 2013a). This most recent listing includes 1,026 native (to the U.S. or its territories) species of birds whose take, possession, transportation, sale, purchase, barter, exportation, and importation is regulated by the MBTA. Of the 84 bird species observed within the plan area by Transcon (2013), all but five species (i.e., Gambel’s quail, rock pigeon, house sparrow, Eurasian collared-dove, and European starling) are included in the current list and are therefore afforded protection under the MBTA.

4.3                             Environmental Consequences

This section describes potential direct, indirect, and cumulative impacts that may result from implementation of remediation alternatives over the planned remediation period (50 years, generally through 2068). Potential impacts include injury or mortality through a variety of mechanisms including

 

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land clearing; excavation and drilling; facility construction, O&M, and decommissioning activities during remediation; harm or harassment through loss or disturbance of suitable habitats; and injury, mortality, harm, or harassment through a number of other impact pathways.

For purposes of analysis in this EA, the direct and indirect impacts are defined as those actions affecting biological resources in the plan area; specifically, individuals of listed species, suitable habitat for listed species, and sensitive species individuals and life-stages. Several different types of facilities could be constructed during the next 50 years, potentially affecting wildlife habitat areas. Habitat values prior to construction are assumed to be permanently lost following construction of surface facilities. As such, these areas are considered permanently impacted and would offer little habitat value for wildlife species following construction. Other lands could be disturbed during construction of subsurface facilities (e.g., conveyance pipelines). No permanent surface structures would occupy these areas following construction, and these areas are therefore considered temporarily impacted.

4.3.1                       Alternative 1: No Action

4.3.1.1         Desert Tortoise

Impacts to Individuals from Facility Construction

Desert tortoises are not expected to be directly killed or injured by facility construction under Alternative 1 during the remediation period because very little new construction would occur. New groundwater monitoring wells and access roads that could be constructed under Alternative 1 would be located within areas that have been previously disturbed (e.g., roadsides and previously cleared areas) and do not provide suitable habitat for desert tortoise. In addition, PG&E would continue to implement the following MMs identified in the Water Board’s FEIR (2013) to ensure that desert tortoises are not directly killed or injured during construction activities:

  • PG&E will continue to ensure that all employees, subcontractors, and others who work onsite have been adequately trained to avoid and minimize impacts to desert tortoise and their suitable habitat through participation in a desert tortoise awareness program prior to initiation of construction activities (MM BIO-MM-1c). Among other requirements, remediation project workers are not allowed to bring firearms or pets to work areas (MM BIO-MM-1e).
  • Pre-construction clearance surveys for desert tortoise will continue to be completed by an experienced desert tortoise biologist to ensure that desert tortoises are not present at a project work area (MM BIO-MM-1a). All desert tortoises sighted within a project work area will continue to be immediately reported and construction activity jeopardizing the tortoise halted immediately until an authorized biologist is notified to assess the situation. Work will not be resumed until authorized by the biologist and the tortoise has passively moved from the work area or has been physically relocated by an authorized handler to a location out of harm’s way. Only agency-authorized biologists are allowed to physically and actively move tortoises from harms-way (MM BIO-MM-1a).
  • PG&E will continue to install desert tortoise exclusion fencing around the perimeters of work areas prior to ground disturbing activities to prevent encounters with desert tortoises during construction. Exclusion fencing will also continue to be installed around permanent buildings and structures to prevent tortoise entrapment or negative interactions with tortoises. Daily preconstruction sweeps within the proposed project area will be conducted before construction to ensure that desert tortoises are absent from the project area (MM BIO-MM-1a).
  • Biological monitors approved by CDFW (MM BIO-MM-1a) will continue to inspect the exclusion fencing during construction and ground-clearing activities within the fenced areas (MM BIO-MM- 1d). Construction monitoring will continue to be implemented to document if desert tortoises observed within 100 feet of construction locations display negative qualitative responses from vibration (MM BIO-MM-1a).

 

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  • Potential hazards to desert tortoise such as open trenches and holes will continue to be fenced or covered overnight (MM BIO-MM-1e).
    • Vehicle speeds would not exceed 10 miles per hour through desert tortoise habitat during travel associated with the remediation activities except on paved roads with posted speed limits (MM BIO- MM-1e).

In addition to these avoidance measures prior to and during construction activities, project personnel would be required to use established roadways (paved or unpaved) to minimize the potential for mortality of desert tortoise individuals during travel to and from work areas. Cross-country vehicle and equipment use outside designated access roads and work areas would continue to be prohibited.

Employees would continue to be required to visually inspect beneath vehicles, equipment, and stockpiled materials prior to moving them if parked outside of desert tortoise-fenced enclosures. If a desert tortoise is discovered, the vehicle or equipment will not be moved until the tortoise has moved a safe distance away on its own.

Impacts to Individuals from Facility O&M

The greatest risk to desert tortoises during facility O&M is vehicle strikes from remediation-related vehicular traffic. Desert tortoises in burrows could also be crushed by vehicles or excavation equipment during facility O&M. Because remediation facilities are visited and operated frequently, and because desert tortoise habitat is not present at existing facility locations, the potential for desert tortoises to establish an active burrow site at an existing facility location is very low. Implementation of the avoidance measures listed above (for construction activities) would avoid tortoise death or injury from remediation O&M activities. Similarly, continued implementation of restrictions on vehicular use would avoid desert tortoise fatalities or injuries from vehicle strikes on established access roads.

It is possible that desert tortoises could be trapped within existing fenced ATUs after they are constructed if tortoise fencing and ATU entry gates are not maintained as an impermeable barrier. PG&E conducts daily inspections of tortoise exclusion fencing during ground-clearing and construction activities, and no less than weekly thereafter (MM BIO-MM-1d), and completes inspections of exclusion fencing as a condition of implementing its IPMP at ATUs (MM BIO-MM-1i).

Impacts to Individuals from Facility Decommissioning

Remediation facilities are visited and operated frequently. Therefore, the potential for desert tortoises to establish an active burrow site at an existing facility location, and therefore be affected by decommissioning, is very low. Implementation of the avoidance measures listed above (for construction activities) would avoid tortoise death or injury from decommissioning activities. Similarly, continued implementation of restrictions on vehicular use would avoid tortoise mortality or injury from vehicle strikes on established access roads, or at facility decommissioning sites.

Other Impact Pathways

Edge Effects. Noise, vibration, and light associated with facility construction, O&M, and decommissioning could indirectly impact desert tortoises adjacent to permanent and temporary impact areas by “spilling out” to areas adjacent to facilities and influencing essential tortoise functions such as feeding, sheltering, movement, and reproducing. PG&E will continue to implement noise and vibration control measures (MM NOI-MM-1) to ensure that noise and vibration levels comply with San Bernardino County noise standards, and will continue to monitor observed tortoises near construction sites to document if they display negative behaviors as a result of project vibration (MM BIO-MM-1a). The Water Board’s FEIR does not provide direction on what actions PG&E would take if a negative reaction is observed. Similarly, the lead biologist would confirm that lighting plans have been reviewed and that night lighting spillover has been minimized to avoid or reduce indirect impacts to sensitive species

 

 

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(MM BIO-MM-1j). With continued implementation of these measures under Alternative 1, desert tortoises will not be substantially impacted by edge effect stressors.

Groundwater Contaminants. PG&E maintains tortoise-proof fencing around all ATUs, which avoids tortoise exposure to groundwater contaminants such as chromium (all forms), arsenic, manganese, and uranium. The Ecological Risk Assessment Update prepared for PG&E (CH2M, 2016) evaluated the potential risks of contaminant exposure to wildlife species in the plan area. Current and future condition hazard quotients for the desert tortoise in both the initial and refined screening were less than one, indicating no contaminant risk to desert tortoises, should they somehow enter fenced ATUs.

Pesticides. Desert tortoises exposed to pesticides (herbicides, rodenticides, fungicides) applied to ATUs could be at risk of mortality or injury should they be present in ATUs during or shortly after pesticide application. Consistent with the Water Board’s FEIR (MM BIO-MM-1i), PG&E has prepared and is currently implementing an IPMP for all ATUs (Arcadis, 2014a). The IPMP contains a suite of biological, mechanical, and chemical approaches to pest management at operating ATUs. Desert tortoise are excluded from ATUs by tortoise fencing to prevent their exposure to agricultural pesticides used at ATUs. Desert tortoises could therefore be exposed to pesticides used at ATUs under Alternative 1 if unmaintained fencing allowed access to ATUs.

Altered Predation Pressure. The Revised Desert Tortoise Recovery Plan (USFWS, 2011a) identifies common ravens, coyotes, and free-roaming domestic dogs as important predators of tortoises. Road- killed animals and trash may attract common ravens to an area, thereby increasing predation vulnerability of desert tortoises adjacent to roads and in the plan area where trash may accumulate. Ponded surface water may also attract predators of desert tortoises.

As required by the Water Board’s FEIR (MM BIO-MM-1f), PG&E has developed and is implementing a RMP to reduce raven predation on desert tortoises (Arcadis, 2017). The purpose of this plan is to provide management guidelines to prevent the attraction of ravens to remediation areas and to ensure that the current raven population does not significantly increase as a result of project activities associated with remediation. With implementation of the RMP, trash and food items are contained in closed containers and removed from construction sites daily to reduce food subsidies for opportunistic predators such as ravens, coyotes, and feral dogs. Biological monitors are required to contact county animal control services to request removal of carcasses when road kill of large animals such as feral dogs and cats, coyotes, foxes, and other animals is observed in the plan area. Removing carcasses from the project site whenever feasible assists in eliminating this common raven food source. Project water trucks also avoid watering rates that create surface ponding and predator water subsidies (MM BIO- MM-1f).

PG&E’s RMP (Arcadis, 2017) and IPMP (Arcadis, 2014a) also require ATUs to be operated to avoid significant (defined as greater than 24 hours’ duration) surface water ponding that may attract common ravens or other potential desert tortoise predators. To minimize nesting and roosting opportunities for ravens, utility poles, fencing, irrigation equipment, and other elevated project infrastructure are limited to those features required for a project. Existing and proposed above-grade infrastructure that provides potentially suitable conditions for ravens is considered for removal from a site or from future project designs. Old and inactive raven nests are removed by the project biologists whenever it is safe and practical to do so. Raven nest construction is discouraged only in the early stages, prior to egg laying, to ensure consistency with MBTA restrictions. With continued implementation of the RMP, the potential for raven predation on desert tortoises would be managed under Alternative 1 and would likely result in decreased predation pressure by ravens on desert tortoises. The benefits of decreased predation by the common raven on the desert tortoise population would likely take time before producing measurable results. Therefore, the magnitude of the benefit achieved by this effort to reduce predation is uncertain.

Invasive Plants. The Revised Desert Tortoise Recovery Plan (USFWS, 2011a) notes that invasive plants represent “…a significant threat to desert tortoise habitat and populations across the species’ range,”

 

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but acknowledges that work remains to determine how to implement weed suppression and eradication effectively. The expansion of non-native plant communities may adversely affect desert tortoise by increasing the frequency of wildfires, and by altering habitat structure and availability of nutritious forage. Under Alternative 1, PG&E will continue to ensure that if reseeding or revegetation is proposed, the proposed seed palette is reviewed by a biologist to ensure it does not contain plants that are considered non-native or invasive in California (MM BIO-MM-1g).

Non-native species grown at ATUs (e.g., rye grass, alfalfa) for remediation of Cr(VI) are largely contained at ATU locations by the application of irrigation water. Weeds are monitored under PG&E’s IPMP, and therefore spread of these species to unirrigated portions of the plan area is unlikely. While non-native, crops grown at ATUs are not considered noxious or highly invasive.

Remediation vehicles and other equipment recently used at other project sites could transport invasive plants or their propagules (seeds, shoots, etc.) to the plan area if machinery is not cleaned/decontaminated prior to use. Under Alternative 1, the likelihood and significance of this impact mechanism is uncertain.

Climate Change. A species status review completed by the Service in 2010 stated that climate change (increased ambient temperatures and altered precipitation patterns) and drought “may become significant factors in the long-term persistence of [desert tortoise],” and added that the rate of warming during the last 30 years is generally higher than at any other time during the last 1,000 years (USFWS, 2010). Modeling efforts suggest that suitable habitat for desert tortoise in the western Sonoran Desert (Colorado Desert in California) will decline substantially as a result of future climate change (Barrows, 2011). Results from a long-term study completed in Joshua Tree National Park from 1978 to 2012 (about

1.5 tortoise generations) suggest that desert tortoise subpopulations may not fare well with increases in drought frequency and duration modeled under future climate change scenarios (Lovich et al., 2014).

To mitigate greenhouse gas emissions associated with remediation activities, PG&E will continue to implement MMs AIR-MM-1 through AIR-MM-8 identified in the Water Board’s FEIR (2013) through the following actions:

  • Utilize clean diesel-powered equipment during construction
  • Ensure fleet modernization for onroad material delivery and haul trucks during construction
  • Implement emission-reduction measures during construction
  • Implement dust control measures during construction and operations
  • Utilize clean diesel-powered equipment for operation of AT and aboveground treatment facilities
    • Implement San Bernardino County greenhouse gas (GHG) construction standards during construction
    • Implement San Bernardino County GHG operational standards for operations
    • Implement San Bernardino County GHG design standards

With implementation of these measures, the remediation activities under Alternative 1 would not substantially contribute to climate change effects and related long-term impacts to desert tortoise.

Summary

By avoiding mortality or injury during facility construction, operation, maintenance, and decommissioning, and by minimizing the potential for adverse effects due to other impact pathways, Alternative 1 would not result in substantial adverse effects to desert tortoise.

 

 

 

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4.3.1.2         Mohave Ground Squirrel

Impacts to Individuals from Facility Construction

No mortality or injury of Mohave ground squirrel is anticipated under Alternative 1 because very little new construction will be completed, and construction would occur within areas that have been previously disturbed (e.g., roadsides) and do not provide suitable habitat for this species. Consistent with the Water Board’s FEIR (MM BIO-MM-1k), focused surveys (Vanherweg, 2012, 2013) and genetic analyses (Leitner and Matocq, 2015) were completed for Mohave ground squirrel and indicated that round-tailed ground squirrels commonly associate with disturbed habitats, while Mohave ground squirrels do not appear to associate with disturbed habitat areas. Further, no genetically pure Mohave ground squirrels were detected during these focused investigations. For these reasons, Mohave ground squirrels are unlikely to be killed or injured from construction activities.

Impacts to Individuals from Facility O&M

Similar to desert tortoise, the potential for injury or mortality of Mohave ground squirrel individuals during travel to and from facility O&M areas will be minimized through PG&E’s use of existing roads and by limiting travel speeds. Existing facilities are visited routinely for O&M, and the potential for Mohave ground squirrels to establish active burrow sites at these locations is therefore low. No genetically pure Mohave ground squirrels have been detected in the plan area, with round-tailed ground squirrels commonly found in the developed portions of the plan area where most O&M work would be completed (i.e., in OU1 and OU2). For these reasons, it is very unlikely that Mohave ground squirrels would be killed or injured by facility O&M activities under Alternative 1.

Impacts to Individuals from Facility Decommissioning

Similar to desert tortoise, the potential for injury or mortality of Mohave ground squirrel individuals from facility decommissioning is very low. Decommissioning activities will occur within regularly visited, disturbed areas that are unlikely to support Mohave ground squirrels. As such, it is unlikely that Mohave ground squirrels would establish active burrows at facility locations planned for decommissioning.

PG&E’s continued implementation of restrictions on vehicular use would avoid Mohave ground squirrel mortality or injury from vehicle strikes on established access roads, or at facility decommissioning sites while completing facility decommissioning.

Other Impact Pathways

Edge Effects. As described above for desert tortoise, remediation activities would increase noise, vibration, and lighting in areas adjacent to project sites. Such increases may preclude Mohave ground squirrels from using otherwise suitable habitat. Consistent with the Water Board’s FEIR (MM NOI- MM-1), PG&E will continue to implement noise and vibration control measures to reduce noise and vibration. Similarly, the lead biologist would confirm that lighting plans have been reviewed and that night lighting spillover has been minimized to avoid or reduce indirect impacts to sensitive species

(MM BIO-MM-1j). With continued implementation of these measures, Mohave ground squirrels will not be substantially impacted by edge effect stressors.

Groundwater Contaminants. The Ecological Risk Assessment Update prepared for PG&E (CH2M, 2016) evaluated the potential risks of contaminants exposure to wildlife species in the plan area. Exposure estimates for the Mohave ground squirrel at two depth intervals (less than 2 feet below ground surface [bgs] and 0 to 6 feet bgs) were less than the mammalian Low Toxicity Reference Value for arsenic, total chromium, manganese, and uranium under current and future conditions. Therefore, no adverse effects are predicted for Mohave ground squirrels.

Pesticides. The Service (USFWS, 2011b) could find no information regarding the relationship between pesticide use and Mohave ground squirrel effects from direct exposure, reduction of forage, or bioaccumulation from eating treated plants or insects. PG&E has prepared an IPMP to ensure that that

 

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any proposed use of pesticides at ATUs will pose a negligible risk to wildlife species (Arcadis, 2014a). With implementation of the IPMP, and application of pesticides following product labeling, it is anticipated that Mohave ground squirrels will not be affected by project-related pesticide use.

Altered Predation Pressure. The increase in the abundance of common raven in the Mojave Desert represents a predation risk to Mohave ground squirrels (USFWS, 2011b). Road-killed animals and trash may attract common ravens to an area, thereby increasing predation vulnerability to squirrels adjacent to roads. This “road-effect zone” can effectively be up to three times the size of the footprint of the road itself (USFWS, 2011b). Harris and Leitner (2005) reported that dispersing juveniles suffered apparently high predation rates (nine of 29 study animals, or 31 percent), but their study did not report species responsible for apparent predation losses. While common raven predation on Mohave ground squirrels occurs (MGSWG, 2006), the Service (USFWS, 2011b) did not consider this a significant threat to the species.

Invasive Plants. The proliferation of non-native plants is not included in the list of stressors that the Service (USFWS, 2011b) considered in its analysis of listing eligibility for the Mohave ground squirrel. However, the associated risk of increased wildfire recurrence in non-native vegetation types noted above for the desert tortoise is also applicable to Mohave ground squirrel.

Under Alternative 1, PG&E will continue to ensure that if reseeding or revegetation is proposed, the proposed seed palette is reviewed by a biologist to ensure it does not contain plants that are considered non-native or invasive in California (MM BIO-MM-1g). As described above for desert tortoise, the spread of non-native species grown at ATUs (e.g., rye grass, alfalfa) to unirrigated portions of the plan area is unlikely, and are therefore not expected to affect impact Mohave ground squirrel by competing with native forage plant species or by increasing the risk of wildfire.

Remediation vehicles and other equipment recently used at other project sites could transport invasive plants or their propagules (seeds, shoots, etc.) to the plan area if machinery is not cleaned/decontaminated prior to use. Under Alternative 1, the likelihood and significance of this impact mechanism is uncertain.

Climate Change. The Service (USFWS, 2011b) evaluated the potential influence of climate change on Mohave ground squirrels at length, noting that its primary impact is likely to be changes in the availability and distribution of suitable habitat. In summary, a warming climate in the Mojave Desert is predicted to elicit one or more of three potential responses for Mohave ground squirrel: constrict its range, transpose its range farther north, and/or move its distribution to higher elevations. The Service (USFWS, 2011b) notes that quantifying or describing how these responses will ultimately influence Mohave ground squirrel survival and condition is speculative. A report recently made available by the California Energy Commission (Esque et al., 2013) reports the results of climate change modeling for Mohave ground squirrel. In summary, modeling predicted that by 2030 losses of suitable habitat will be 52 to 57 percent of the currently mapped geographic range of Mohave ground squirrel. These losses are predicted to increase to approximately 84 percent by 2080.

To mitigate greenhouse gas emissions associated with remediation activities, and consistent with the Water Board’s FEIR (2013), PG&E will continue to implement MMs AIR-MM-1 through AIR-MM-8 as summarized above for desert tortoise. With implementation of these measures, the remediation activities under Alternative 1 would not substantially contribute to climate change effects and related long-term impacts to Mohave ground squirrels.

Summary

By avoiding mortality or injury during facility construction, operation, maintenance, and decommissioning, and by minimizing the potential for adverse effects due to other impact pathways, Alternative 1 would not result in substantial adverse effects to Mohave ground squirrel.

 

 

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4.3.1.3         Burrowing Owl

Impacts to Individuals

To avoid direct impacts on burrowing owl, PG&E has prepared and is implementing a Burrowing Owl Protection Plan (Arcadis, 2014b) that includes measures to ensure the protection of burrowing owls prior to and during construction and remediation activities. Whenever possible, ground-clearing and construction activity is scheduled to occur in the nonbreeding season (September 1 through January 31). In addition, new remediation facilities would be located to avoid historical burrowing owl burrow locations and suitable burrowing owl habitat within the plan area whenever possible.

By implementing the Burrowing Owl Protection Plan, PG&E would continue to ensure that all employees, subcontractors, and others who work onsite have been adequately trained to avoid and minimize impacts to burrowing owl and their habitat through participation in an environmental training and awareness program prior to initiation of construction activities (MM BIO-MM-1c). At a minimum, the training will provide the following burrowing owl information:

  • Distribution of sensitive species including burrowing owl on the job site
  • General burrowing owl behavior and ecology
  • Sensitivity to human activities
  • Legal protection
  • Penalties for violating state or federal laws
  • Reporting requirements
  • Project protective MMs

As described in the Burrowing Owl Protection Plan (Arcadis, 2014b), PG&E would conduct focused nesting season surveys for burrowing owls prior to any ground-clearing activity including a 400-foot buffer surrounding the project work area (MM-BIO-MM-1l). Nesting season surveys would follow the most recent CDFW survey protocol (including any variations in the protocol that may be approved by CDFW for the survey). Prior to ground disturbance, preconstruction reconnaissance surveys focusing on burrowing owls would be conducted no earlier than 14 days prior to scheduled clearing. In addition, final preconstruction reconnaissance surveys would be conducted 24 hours prior to start of ground clearing or other activity that may disturb burrowing owls.

If an occupied burrowing owl burrow is identified during preconstruction or focused nesting season surveys within the proposed project footprint or within the 400-foot buffer area, the following avoidance measures, consistent with the Water Board’s FEIR (MM BIO-MM-1l), would be implemented:

  • Any burrow determined to be occupied due to either the observation of burrowing owls at the burrow or due to the presence of owl sign at the burrow entrance will be provided an appropriate no-disturbance buffer (160 feet during the nonbreeding season, and 250 feet during breeding season unless otherwise approved by CDFW).
  • The no-disturbance buffer zone surrounding active burrows would be delineated in the field. Biological monitors setting up buffer zones around occupied burrows would use discretion when considering use of colored flags, ribbons, hay bales, fencing, or screens, as these may be attractants and/or used as perches by common ravens or raptors that could pose a potential threat to burrowing owls or other sensitive wildlife potentially present in the area.
  • Biological monitors would inform construction personnel of the location of the designated sensitive resource buffer zone and reiterate the requirement to remain outside of this zone.

 

 

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  • A biological monitor would be present during construction activities that have the potential to disturb known burrowing owl individuals or nests. Fulltime biological monitoring may be reduced following a determination by the biological monitor and senior biologist that the burrowing owls are no longer attempting to use the remedial work area, or that ongoing work activities are not disturbing owls located in an exclusion zone.
    • Work within a buffer zone around a confirmed burrowing owl nest location would only commence when it is determined that juvenile owls from the burrow are foraging independently and capable of independent survival and the occupants have left the burrow. If construction work must occur within a buffer zone, an experienced biologist will monitor the burrowing owls for disturbance and will guide work to minimize disturbance. The monitor shall stop work if removal or disturbance of an active nest or individual burrowing owl is anticipated.
    • To the extent feasible, construction activities will be started as far as possible from occupied burrows to allow the owls to become acclimated as work progresses towards occupied burrows.

As described in the Burrowing Owl Protection Plan (Arcadis, 2014b), the potential for direct injury or mortality of burrowing owl individuals during travel to and from work areas would be minimized through use of existing roads and speed limits. Except on paved roads with posted speed limits, vehicle speeds would not exceed 10 miles per hour during travel, especially in the vicinity of any occupied burrows and associated buffer zones. Work areas would be kept free of debris and all openings in structures and equipment would be sealed the open ends to prevent burrowing owls from using them as refuge sites. If water is applied to roads or project sites to control dust, pooling of water will be avoided to minimize the potential to attract burrowing owls and common ravens or other predators. Trash and food items would be contained in closed containers and removed from the site daily to reduce attractiveness to opportunistic predators such as ravens, coyotes, and feral dogs. The job site would be inspected daily prior to construction activity and throughout the day to assess changing conditions from clearing and construction that may attract burrowing owls into work areas. Construction personnel would be prohibited from bringing domestic dogs to the work site because domestic dogs may flush burrowing owls from occupied burrows, exposing them to raptor predators such as prairie falcons or Cooper’s hawks. These measures would be covered in the Environmental Awareness Training Program. Implementation of the Burrowing Owl Protection Plan is anticipated to avoid direct harm and mortality of burrowing owls during construction and remediation activities under Alternative 1.

Habitat Loss

Over time, development of facilities under Alternative 1 is expected to result in the temporary disturbance of approximately 13 acres of land, with a permanent footprint of less than 1 acre. No activities would occur in suitable desert tortoise habitat, but could occur in areas used by burrowing owls. As described in the Burrowing Owl Protection Plan, proposed placement of project infrastructure during the planning phase will avoid historical burrowing owl burrow locations and suitable burrowing habitat within the project area whenever possible. ATUs attract and support populations of invertebrates and small mammals, which in turn may create high quality burrowing owl foraging habitat that could have a long-term beneficial impact. In addition, areas disturbed as a result of project-related activities would be stabilized and revegetated, consistent with Water Board permit requirements (Water Board, 2013). Emergency repair work would be performed in areas previously disturbed during the initial installation of facilities. Implementation of the Burrowing Owl Protection Plan as described above would avoid indirect impacts to burrowing owl through disturbance or removal of their habitat (i.e., burrows) during construction and remediation activities.

Other Impact Pathways

Edge Effects. Noise, vibration, and light associated with facility construction, O&M, and decommissioning could indirectly impact burrowing owls. Similar to the desert tortoise and Mohave

 

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ground squirrel, the sensitivity of burrowing owl to noise (and vibration) is not well documented, but the male (who is largely aboveground during the nesting cycle) could exhibit negative reactions to increases in noise and vibration levels above existing conditions that could cause nest abandonment and death of young or loss of reproductive potential at active nests. Burrowing owls are also known to be active during both the daytime and nighttime and therefore may be disrupted in the event they are affected by night lighting of facilities or emergency operations and maintenance activities. PG&E will continue to implement noise and vibration control measures (MM NOI-MM-1) to reduce noise and vibration.

Similarly, the lead biologist would confirm that lighting plans have been reviewed and that night lighting spillover has been minimized to avoid or reduce indirect impacts to sensitive species (MM BIO-MM-1j). With continued implementation of these measures, burrowing owls will not be substantially impacted by edge effect stressors.

Groundwater Contaminants. The Ecological Risk Assessment Update prepared for PG&E (CH2M, 2016) evaluated the potential risks of contaminants exposure to wildlife species in the plan area. Exposure estimates for the burrowing owl at both depth intervals (less than 2 feet bgs and 0 to 6 feet bgs) were less than the avian Low toxicity reference value for arsenic, manganese, and uranium under current and future conditions. Therefore, no adverse effects are predicted for burrowing owl exposed to these analytes under Alternative 1.

Pesticides. As described above for desert tortoise and other species, PG&E has prepared an IPMP to be implemented for all new and existing ATUs (Arcadis, 2014a). The IPMP explicitly details an approach to ensure that operation of ATUs, and risks of any proposed use of herbicides, pesticides, or rodenticides will pose a negligible risk to wildlife species.

Summary

By avoiding mortality or injury during facility construction, O&M, and decommissioning, and by minimizing the potential for adverse effects due to other impact pathways, activities implemented under Alternative 1 would not result in substantial adverse effects to burrowing owls.

4.3.1.4         Bald and Golden Eagle

Suitable nesting habitat for golden eagles does not occur in the majority of the plan area, but golden eagles may forage in the plan area. Suitable nesting and foraging habitat for bald eagle does not occur in the plan area. However, PG&E has prepared and would implement species-specific buffers to ensure the protection of special-status migratory birds (including bald and golden eagles) prior to and during construction and remediation activities (Appendix A).

With implementation of species-specific buffers under Alternative 1, a qualified biologist would conduct a preconstruction survey in areas of potentially suitable habitat for nests and nesting bird behavior prior to the initiation of any ground disturbing or noise generating project activities between February 1 and August 31. If an active golden eagle nest is identified during the preconstruction surveys within the proposed project footprint, a standard buffer of 2,640 feet will be established around identified active golden eagle nests. Consultation with the Service would be required to work within the buffer (Appendix A).

The Ecological Risk Assessment Update prepared for PG&E (CH2M, 2016) evaluated the potential risks of contaminants exposure to wildlife species in the plan area. Exposure estimates for the American kestrel were less than the avian Low toxicity reference value for arsenic, manganese, and uranium (i.e., hazard quotients less than 1) under current conditions and future conditions. The American kestrel was selected as a surrogate for the golden eagle, a special-status species. The golden eagle has a very large home range compared to the kestrel. Considering the larger home range size, exposure estimates for golden eagles would be much lower than those estimated for kestrels (CH2M, 2016). Therefore, there are no adverse effects predicted for golden eagles exposed to these analytes under Alternative 1.

 

 

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PG&E has prepared an IPMP to be implemented for all new (and existing) ATUs. The IPMP explicitly details an approach to ensure that operation of ATUs, and risks of any proposed use of herbicides, pesticides, or rodenticides will pose a negligible risk to wildlife species (Arcadis, 2014a).

With implementation of the species-specific buffer, mortality or injury of bald and golden eagles during facility construction, operation, and decommissioning would be avoided. Implementation of the IPMP will minimize the potential for adverse effects due to use of herbicides, pesticides, or rodenticides.

Therefore, Alternative 1 would not result in substantial adverse effects to bald and golden eagles.

4.3.1.5         Other Migratory Birds

PG&E has prepared and would implement species-specific buffers to ensure the protection of birds covered by the MBTA prior to and during construction and remediation activities (Appendix A).

Implementation of the species-specific buffers is anticipated to avoid direct harm and mortality of nesting migratory birds during construction and remediation activities under Alternative 1.

4.3.2                       Alternative 2: PG&E’s Proposed Hinkley Groundwater Remedy HCP

4.3.2.1         Desert Tortoise

Impacts to Individuals from Facility Construction

Desert tortoise could be killed or injured by being crushed, struck, or buried by cars or equipment during land clearing activities, site excavations, and facility construction (including ATUs). Land clearing and major land-disturbing activities would typically be conducted prior to or during construction of facilities. Similar to Alternative 1, prior to implementing any ground-disturbing activity at a project site (including installation of desert tortoise exclusion fencing), PG&E will ensure that the Authorized Biologist and/or Biological Monitor has completed a pre-activity survey for covered species within each work area to ensure that covered species are absent. The number of desert tortoises that could be killed or injured by land-clearing/disturbing activities is uncertain, but is expected to be very low. The highest density of desert tortoises estimated by SBI (2013) in the plan area was 0.005-tortoise per acre.9 Applying this estimate to the total acreage of suitable habitat potentially affected in the plan area (867 acres)

(Table 3-1) results in an estimate of 4.2 tortoises potentially exposed to land clearing activities that may result in injury or mortality. Most tortoises would be moved from harms-way prior to land-clearing/land- disturbing activities. Therefore, the Service estimates that no more than two desert tortoises could be killed or injured as a result of initial land clearing/disturbing activities during the permit term. The actual number of desert tortoises potentially taken in this manner is expected to be even lower with implementation of HCP conservation measures.

Direct injury or mortality of desert tortoises at construction sites and during construction activities could occur by vehicle or equipment strikes, by vehicles crushing individuals located in or outside of burrows, or by tortoises becoming trapped in pits, trenches, or open pipes. Injury to or mortality of desert tortoises could also occur during excavation if individuals in burrows are present at a construction location. Similar to Alternative 1, PG&E would implement a number of avoidance measures under Alternative 2 to minimize the potential for desert tortoise to be directly harmed or killed during construction activities. The avoidance measures include employee training, pre-construction surveys, biological monitoring, and covering of open trenches and holes within the work area as described above for Alternative 1. Permanent desert tortoise exclusion fencing will also be installed and maintained around all permanent buildings and structures where entrapment or negative interactions with tortoises could occur. All ATUs will have permanent desert tortoise exclusion fencing. Exclusion fence damage will be repaired within two days of observing the damage under Alternative 2. The Service estimates that up

 

9  As discussed in Chapter 3 of the HCP, this estimate is likely inflated and a result of a very small sample size. A more representative estimate is likely 0.002-tortoise per acre, which is the density of tortoises estimated by SBI (2013) in high-value habitat in OU3.

 

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to two tortoises could be killed or injured as a result of facility construction during the permit term. Impacts will likely be less than these estimates as the original ground disturbing activities will have already been completed when facilities are constructed.

Impacts to Individuals from Facility O&M

Existing facilities, and facilities that would be constructed under Alternative 2, would be operated and maintained during the permit term. Conveyance pipelines are flushed, jetted, and cleaned every 3 to 5 years to maintain performance. Access roads require periodic maintenance, and are used (operated) frequently to access facilities for their operation and maintenance. Desert tortoises could be injured or killed by vehicle strikes on plan area roads or at pipeline maintenance work sites. Any road maintenance that removes or adds material to berms could impact desert tortoise burrows and any tortoise occupying them by direct injury or mortality from the equipment or by burying them. Monitoring of wells is not expected to substantially expose desert tortoise to mortality or injury because most wells are installed at cleared roadside areas, or at locations cleared during the installation process. However, some monitoring wells are located in remote areas and require travel on narrow, single-lane dirt roads immediately adjacent to or through habitat. In these circumstances, vehicular travel may have a higher chance of exposing desert tortoise to injury or death by vehicle strike. Desert tortoises present at an active ATU could be injured or killed by crushing from ATU equipment and/or personnel during O&M activities. ATU crops are harvested periodically but somewhat regularly, which could further expose desert tortoises to injury or mortality by harvesting equipment and personnel. Desert tortoise-proof gates will be installed at all entry points to ATUs and other permanently fenced facilities requiring frequent human ingress and egress. Single-slot tortoise guards may be installed in lieu of tortoise-proof gates for access to permanently fenced facilities when exclusion fencing is installed within a limited area within which Biological Monitors may conduct desert tortoise clearance surveys (Figure 2-5). However, exclusion fencing around ATUs will effectively isolate desert tortoises from the ATU and minimize the potential for injury or mortality during O&M activities.

As described for Alternative 1, project personnel would use established roadways (paved or unpaved) to travel to and from work areas to minimize the potential for mortality of desert tortoise individuals.

Cross-country vehicle and equipment use outside designated access roads and work areas would be prohibited. Except on paved roads with posted speed limits, vehicle speeds on dirt access roads would not exceed 10 miles per hour. Implementation of the HCP conservation program would avoid or minimize the potential for direct harm or mortality of desert tortoise to the maximum extent practicable. The Service anticipates that no more than two desert tortoises would be killed or injured by vehicle strikes on access roads or from ATU operations and maintenance during the permit term.

Desert tortoises could be trapped within fenced ATUs. This could occur if desert tortoises are not completely relocated from within fenced areas prior to completion of exclusion fencing, and/or tortoises gain entry to fenced areas after installation of fencing during construction and O&M. The likelihood of either of these scenarios is very small with the CMs PG&E will implement in its HCP. The Service estimates that up to one desert tortoise could be trapped within an enclosed facility, such as a fenced ATU, during the permit term.

Impacts to Individuals from Facility Decommissioning

Following the end of their useful terms, remediation facilities may be removed and/or rendered inoperable (decommissioned) during the permit term. Desert tortoises could be injured or killed during facility removal similar to the potential impacts for facility construction. Equipment and personnel could crush or otherwise kill or injure tortoises at the facility removal site, or could crush or bury individual tortoises within burrows at a removal site. However, because facility removal would occur at previously disturbed locations, the potential presence of desert tortoises is expected to be lower than the potential that would exist at a site initially being cleared prior to construction. As described in Chapter 2, PG&E on occasion will demolish plan area structures following property acquisitions. Desert tortoise may be

 

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injured or killed during structure demolitions conducted by PG&E in the plan area. Desert tortoises have been observed in association with some of these properties. In some cases, these occurrences may represent captive desert tortoises that have been released, or may be wild desert tortoises that occur or maintain burrows at these locations (e.g., burrows beneath foundations or lumber scraps). With implementation of the Alternative 2 conservation strategy, the Service does not anticipate killing or injuring desert tortoise from decommissioning of facilities.

Impacts to Individuals from Handling During Translocations

Unlike under Alternative 1, desert tortoises may be captured and moved from harm’s way (translocated) prior to and during construction, O&M, and decommissioning of facilities under Alternative 2. Desert tortoises found at a facility construction or decommissioning site may be moved from harm’s way by an approved biologist, or may be left to move from harm’s way on their own. Desert tortoises to be moved would be handled following a translocation protocol prepared by PG&E and approved by the agencies (Chapter 5 of the HCP). The Service expects that most desert tortoises found at an active construction or decommissioning site will be allowed to move from harms-way on their own. Regardless, the Service estimates that up to five tortoises may be captured and moved from harms-way over the permit term in association with facility construction or decommissioning. Tortoises encountered during O&M activities will in most cases be allowed to leave the site on their own. However, after a period of time if a tortoise does not willingly exit an enclosed area it may need to be physically moved by an authorized biologist.

The Service estimates that up to ten desert tortoises may need to be translocated during the permit Term while completing facility O&M.

Habitat Loss and Effects on Individuals

Desert tortoise may be impacted if removal or degradation of suitable habitat impairs or disrupts their behavioral patterns. Disturbance or degradation of suitable habitat could negatively influence desert tortoise foraging, sheltering, movement, and reproductive behaviors. Similar to Alternative 1, under Alternative 2 suitable habitat for covered species will be avoided wherever practical and areas of disturbance will be confined to the smallest practical area, considering topography, placement of facilities, location of occupied desert tortoise habitat, public health and safety, and other limiting factors, and will be located in previously disturbed areas to the extent possible. Under Alternative 2, when avoidance of suitable habitat for desert tortoise is not practical, PG&E would locate facilities and implement remediation activities in lower quality habitat areas and would avoid disturbances within higher quality habitat areas, where possible (Alternative 1 would avoid all impacts to desert tortoise habitat).

While implementation of the conservation measures described above and in Chapter 5 of the HCP is expected to avoid or substantially minimize the loss/degradation of suitable habitat, there would be both permanent and temporary disturbance/loss of suitable habitat for covered species, including desert tortoise (no desert tortoise habitat would be impacted under Alterative 1). For purposes of quantifying suitable habitat for desert tortoise, and based on their associations with plan area cover types described above, the Service assumes the following:

  • All Natural/Undisturbed land cover types provide higher-value habitat (here forward referred to as “high-value habitat”) for covered species than previously disturbed or developed areas.
  • Disturbed but recovering land areas (denuded/recovering category of SBI, 2013a) provide lower- quality habitat (here forward referred to as “low-value habitat”) for covered species (relative to Natural/Undisturbed areas).

 

 

 

 

 

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  • Active Urban and Agricultural areas, and previously disturbed areas not showing recovery (denuded/total category [SBI, 2013]), provide no habitat value for covered species.10

Full build-out of remediation facilities under Alternative 2 is anticipated to result in the temporary disturbance of 173 acres and permanently impact 699 acres of suitable desert tortoise habitat in the plan area (Table 4-1). There would be a permanent impact on 366 acres of high-value habitat of and temporary disturbance of up to 95 acres of high-value habitats for desert tortoise. Up to 76 acres of low- value habitat would be temporarily disturbed and approximately 334 acres of low-value habitat would be permanently impacted (Table 4-1).

To compensate for impacts to covered species habitats resulting from implementation of remediation activities, PG&E will acquire in fee title, secure a conservation easement, secure purchase mitigation bank credits, or work with a third-party entity to identify, secure, and manage in-perpetuity up to 1,798 acres of suitable covered species habitat at a location or locations approved by the agencies (i.e., the conservation lands [CM-20]).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10 While active Urban and active agriculture land cover types lands are not considered suitable habitat for Covered Species, Covered Species individuals may on occasion be found in association with these land cover types. In these circumstances, PG&E will implement measures to avoid take of individuals while implementing remediation activities.

 

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Table 4-1. Temporary and Permanent Impacts (in acres) to Plan Area Suitable Desert Tortoise Habitat, by Covered Activity and Remediation Phase

 

 

 

Covered Activity

Phase 1

(2018)

Phase 2

(2019-2020)

Phase 3

(2021-2024)

Phase 4

(2025-2068)

All Phases (2018-2068)

Temporary

Permanent

Temporary

Permanent

Temporary

Permanent

Temporary

Permanent

Temporary

Permanent

Groundwater Monitoring

1

<0.1

8

<0.1

0.9

<0.1

8

<0.1

18

<0.1

FreshwaterInjection System                                                    ------------------------------No Freshwater Injection Facilities Constructed------------------------------

AT                                                                        —b                —                  21                 76                  21                76                52                532                                                                             95                 683

 

In Situ Treatment

6

<0.1

0.6

<0.1

2

<0.1

7

<0.1

15

<0.1

Ex Situ Treatment

36

1

36

1

Access Roads

<0.1

<0.1

3

6

0.4

0.6

5

9

9

15

StructureDemolition                                                                                    ------------------------------No Habitat Impacted------------------------------

 

Total Suitable Habitat

7

0.1

34

82

24

76

109

541

173

699

Total for High-value Habitat Only

3

<0.1

20

40

13

40

60

286

97

366

Total for Low-value Habitat Only

4

<0.1

13

42

11

36

48

256

76

334

a All areas rounded to nearest whole acre if at least 1 acre in size, or rounded to nearest 0.1 acre if less than 1 acre is size. Construction areas are in addition to facility footprints.

b Dashes (—) indicate that activity is not anticipated to be implemented.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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As described in Chapter 2 of this EA and in Chapter 5 of the HCP, conservation lands acquired in fee title will be protected in perpetuity with a conservation easement that provides third party beneficiary rights to the Service. A management plan will be drafted for the conservation lands, and an endowment will be established to fund the management, improvement, and monitoring of these lands in perpetuity. The fee title may be held by a private land owner, a nonprofit land trust or the State of California, or by PG&E. The conservation easement would be held by the State of California or a nonprofit land trust who is authorized to hold conservation easements, per California Civil Code 815. A mitigation agreement will be drafted to identify responsibilities and obligations for management and monitoring of lands by involved parties.

Once conservation lands for fee title are identified for acquisition, and PG&E has received approval from the Service on the conservation land parcels, PG&E, its contractor, or a third-party entity will prepare an agency-approved management plan describing how the lands will be managed and monitored. The management plan and conservation easement will be used to calculate the endowment to cover costs of management and monitoring in perpetuity. The endowment calculation shall include a 10 percent contingency factor to cover Adaptive Management, Changed Circumstances, and inflation. The agencies will review and approve the management plan, conservation easement, endowment funding proposal, and mitigation agreement.

Other Impact Pathways

Edge Effects. As described for Alternative 1, facility construction, O&M, and decommissioning would increase noise, vibration, and lighting in areas adjacent to project sites. Such increases may preclude desert tortoises from using otherwise suitable habitat that is not directly affected by remediation activities. The Service reports that ground vibrations can cause desert tortoises to emerge from burrows (USFWS, 1994). The Water Board’s FEIR (2013) noted that plan area construction equipment would create new sources of noise and/or vibration above existing conditions, but concluded that these effects are likely insignificant (noise) or little understood (vibration).

Nighttime lighting associated with in situ and ex situ treatment, and ATU facilities could adversely influence desert tortoise behavior distant from a facility but the exact nature of these impacts to behavior and their severity are unknown. Under Alternative 2, exterior light fixtures and standards would be designed to be fully shielded, directing light downward below the horizontal plane of the fixture height. The lead biologist would confirm that lighting plans have been reviewed and that night lighting spillover has been minimized. Therefore, it is anticipated that night lighting will not result in indirect impacts to covered species.

Because most construction or installation of new facilities would take place within areas that have been previously disturbed and most new facilities would be located in areas that do not provide suitable habitat for desert tortoise, impacts from these “edge effects” would be minimized under Alternative 2. Nevertheless, the potential for edge effect impacts under Alternative 2 would likely be greater than those under Alternative 1 based on the greater magnitude and more extensive locations of remediation activities under Alternative 2. The Service expects very few desert tortoises will be adversely impacted by edge effects.

Groundwater Contaminants. CH2M (2016) prepared an Ecological Risk Assessment Update for PG&E evaluating the risks of groundwater contaminant exposure via application to ATUs to listed and unlisted species (Appendix I of the HCP). Current conditions (in 2015), as well as future conditions under three scenarios (20 years in the IRZ, 75 years for shortest-time remedial alternative, and 95 years for longest- time remedial alternative), were evaluated. No risks were identified for any receptor under current conditions and for the 20-year future scenario. Low-level risks to insectivorous avian and reptilian receptors were predicted under the shortest- and longest-timeframe future scenarios, but these risks are not significant due to low exceedance of the no observed adverse effect level and conservative assumptions used in the exposure and risk models. No risks to desert tortoise were predicted under

 

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current conditions and all future scenarios. In addition, exclusion fencing around ATUs will effectively isolate desert tortoises from exposure to contaminants at ATUs. As such, desert tortoises are not likely to be exposed to groundwater contaminants and will therefore not be adversely affected by these contaminants (i.e., chromium [all forms], arsenic, manganese, uranium) under Alternative 2 (same as under Alternative 1).

Pesticides. Desert tortoises exposed to pesticides (herbicides, rodenticides, fungicides) applied to ATUs could be at risk of mortality or injury should they be present in ATUs during or shortly after pesticide application. PG&E has prepared an IPMP (Arcadis, 2014a) to be implemented for all new (and existing) ATUs. The IPMP contains a suite of biological, mechanical, and chemical approaches to pest management at operating ATUs. Desert tortoise will be excluded from ATUs by tortoise fencing to prevent potential exposure to agricultural pesticides used at ATUs. As such, desert tortoise would not be exposed to pesticides used at ATUs and no adverse effects to this species are anticipated (same as under Alternative 1).

Altered Predation Pressure. The Revised Desert Tortoise Recovery Plan (USFWS, 2011a) identifies common ravens, coyotes, and free-roaming domestic dogs as important predators of tortoises. Road- killed animals and trash may attract common ravens to an area, thereby increasing predation vulnerability of desert tortoises adjacent to roads. Ponded surface water may also attract predators of desert tortoises. As described above for Alternative 1, PG&E is implementing a Common Raven Management Plan (RMP) to reduce raven predation on desert tortoise (Arcadis, 2017). With implementation of the RMP, the potential for raven predation on desert tortoises would be reduced over the 50-year permit term of the ITP. In addition, many of the facilities that PG&E will construct/install in the plan area during the permit term will be buried. These include conveyance pipelines and utility and well vaults. These facilities will not impede surface movement opportunities for desert tortoise, and will not provide perching, roosting, or nesting opportunities for common ravens.

Other facilities will be constructed at or only slightly above surface grade (ATUs, wells) and, as such, will not afford common ravens perching, roosting, or nesting opportunities. The RMP also commits PG&E to ensure that irrigation water applied to ATUs, and water from other remediation activities does not pond on the ground surface for extended periods to minimize supplementing water sources for common ravens.

PG&E has also committed to participating in a regional raven management program administered by the National Fish and Wildlife Foundation (NFWF). Participation in this program will contribute to tortoise conservation in the broader western Mojave Desert. With implementation of these measures under Alternative 2, the Service anticipates that impacts from altered predation pressure will be reduced and may be less than impacts under Alternative 1.

Invasive Plants. As described above for Alternative 1, expansion of non-native plant communities may adversely affect desert tortoise by increasing the frequency of wildfires, and by altering habitat structure and availability of nutritious forage. Similar to Alternative 1, under Alternative 2 PG&E would ensure that any seed mixes used at restoration sites do not contain non-native species. However, under Alternative 2, the Service and CDFW will review and approve seed mixes prior to their use in the plan area, providing additional protection against the expansion of non-native plant communities.

Non-native species grown at ATUs (e.g., rye grass, alfalfa) are largely contained at ATU locations by the application of irrigation water. Weeds are monitored under PG&E’s IPMP, and therefore spread of these species to unirrigated portions of the plan area is unlikely even with expansion of the ATU acreage anticipated under Alternative 2. While non-native, species grown at ATUs are not considered noxious or highly invasive, and plant escapees from ATUs are therefore not expected to affect impact tortoises by competing with native forage plant species or by increasing the risk of wildfire.

Remediation vehicles and other equipment used at other (non-Hinkley) project sites could transport invasive plants or their propagules (seeds, shoots, etc.) to the plan area. PG&E has committed under

 

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Alternative 2 to ensure that offroad vehicles used for remediation activities are free and clear of weed propagules prior to their use in the plan area. With implementation of these measures, the Service anticipates that impacts from invasive plants will be substantially reduced and may be less than impacts under Alternative 1.

Climate Change. As described for Alternative 1, the Service anticipates that climate change (increased ambient temperatures and altered precipitation patterns) and drought “may become significant factors in the long-term persistence of [desert tortoise].” Under Alternative 2, the Water Board’s FEIR (2013) commits PG&E to implement several MMs (AIR-MM-1 through AIR-MM-8) to mitigate greenhouse gas emissions associated with the construction, O&M, and decommissioning of the proposed project and their potential incremental contributions to climate change. With implementation of these measures, the Service does not expect that remediation activities under Alternative 2 (as under Alternative 1) will contribute to climate change effects and related long-term impacts to desert tortoise.

Summary

Under Alternative 2, the Service estimates that up to 15 desert tortoises may be captured and moved from harm’s way over the permit term in association with land clearing activities, facility construction, O&M, and decommissioning (none would be moved under Alternative 1). Up to eight desert tortoises may be killed or injured during land-clearing, facility construction, and/or facility O&M activities during the permit term (none would be killed or injured under Alternative 1). With implementation of conservation measures, the Service estimates that very few to no desert tortoises would be indirectly impacted under Alternative 2 (same as under Alternative 1).

Full build-out of remediation facilities under Alternative 2 is anticipated to temporarily disturb 170 acres and permanently impact 697 acres of suitable desert tortoise habitat in the plan area. To compensate for impacts to desert tortoise habitat resulting from implementation of remediation activities, PG&E will identify, secure, and manage in-perpetuity up to 1,798 acres of suitable desert tortoise habitat at a location or locations approved by the Service. In addition, through implementation of the HCP and associated plans (RMP, IPMP [Arcadis, 2017a, 2014a]), the Service does not anticipate adverse effects on desert tortoises through other impact pathways.

4.3.2.2         Mohave Ground Squirrel

Impacts to Individuals from Facility Construction

Mohave ground squirrels may be killed or injured by being crushed, struck, or buried by cars or equipment during land clearing activities and site excavations. Land clearing and major land-disturbing activities would typically be conducted prior to or during construction of facilities, and are not anticipated to be conducted in association with facility O&M or facility decommissioning. The number of Mohave ground squirrels that could be killed or injured in association with site preparation work is uncertain. The Service anticipates that the potential for death or injury to Mohave ground squirrels would be very low, given the apparent scarcity of this species in the plan area (Vanherweg, 2012, 2013; Leitner and Matocq, 2015). In addition, Alternative 2 provides measures to avoid and minimize potential impacts to Mohave ground squirrels. The Service therefore estimates that no more than two Mohave ground squirrels could be killed or injured as a result of initial land clearing/land disturbing activities during the permit term.

Mohave ground squirrels that are present at a construction site and are not detected during pre-activity surveys (e.g., those in burrows) could be harmed or killed by site grubbing, grading, or excavation. The greatest risk of mortality or injury to Mohave ground squirrels is anticipated to be associated with initial ground-clearing/disturbing activities (see above). During construction, avoidance measures similar to those for desert tortoise would be implemented to avoid direct impacts on Mohave ground squirrel including pre-construction surveys, fencing of project work areas, and biological monitoring. The Service estimates that up to one Mohave ground squirrel (half of the number associated with initial ground

 

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disturbance) could be killed or injured as a result of facility construction during the permit term. Impacts will likely be less than these estimates as the original ground disturbing activities will have already been completed when facilities are constructed, operated, maintained, and decommissioned.

Impacts to Individuals from Facility O&M

Mohave ground squirrels present at an active ATU could be injured or killed by crushing from ATU equipment and/or personnel during O&M activities. ATU crops are harvested periodically but somewhat regularly, which could further expose ground squirrels to injury or mortality by harvesting equipment and personnel. Fencing is unlikely to successfully exclude Mohave ground squirrels from accessing ATUs since they are adept climbers. Mohave ground squirrels also could be killed or injured by vehicle strikes on access roads during O&M activities during the permit term. As under Alternative 1, the potential for killing or injuring Mohave ground squirrels during travel to and from work areas would continue to be minimized by avoiding offroad travel and by adhering to road speed limits. The Service anticipates that impacts to Mohave ground squirrel individuals would be minimal with implementation of the conservation strategy, and anticipates no more than one Mohave ground squirrel would be killed or injured by vehicle strikes on access roads or from ATU operations and maintenance during the permit term.

Impacts to Individuals from Facility Decommissioning

As described for desert tortoise, remediation facilities may be removed and/or rendered inoperable during the permit term. Mohave ground squirrels could be injured or killed during facility decommissioning similar to the potential impacts from facility construction. Equipment and personnel could crush or otherwise kill or injure squirrels at the facility removal site, or could crush or bury individual squirrels within burrows at a removal site. However, because facility removal would occur at previously disturbed and active remediation locations, the potential for presence of Mohave ground squirrels is expected to be lower than the potential that would exist at a site initially being cleared prior to construction. With implementation of the Alternative 2 conservation strategy, the Service does not anticipate killing or injuring Mohave ground squirrels during decommissioning of facilities.

Habitat Loss and Effects on Individuals

As described for Alternative 1, Mohave ground squirrel may be indirectly impacted by removal or degradation of suitable habitat. Habitat effects could negatively influence ground squirrel foraging, sheltering, movement, and reproductive behaviors. Similar to Alternative 1, suitable habitat for covered species will be avoided wherever practical under Alternative 2 and areas of disturbance will be confined to the smallest practical area, considering topography, placement of facilities, location of occupied desert tortoise or Mohave ground squirrel habitat, public health and safety, and other limiting factors, and will be located in previously disturbed areas to the extent possible. When avoidance of suitable habitat for Mohave ground squirrel is not practical, under Alternative 2 PG&E would locate facilities and implement remediation activities in lower quality habitat areas and would avoid disturbances within higher quality habitat areas, where possible (there would be no impacts to suitable Mohave ground squirrel habitat under Alternative 1).

While implementation of the conservation measures described above and in Chapter 5 of the HCP is expected to avoid or substantially minimize the loss/degradation of suitable habitat, there would be both permanent and temporary disturbance/loss of suitable habitat for covered species, including Mohave ground squirrel. The amount of landscape disturbance and alteration as a result of remediation activities, construction, maintenance, and emergency repair would be the same as described above for desert tortoise. To compensate for impacts to covered species habitats resulting from implementation of remediation activities, PG&E would acquire in fee title, secure a conservation easement, purchase mitigation bank credits, or work with a third-party entity to identify, secure, and manage in-perpetuity up to 1,798 acres of suitable covered species habitat at a location or locations approved by the agencies.

 

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Other Impact Pathways

Edge Effects. As described above for desert tortoise, facility construction, O&M, and decommissioning would increase noise, vibration, and lighting in areas adjacent to project sites. Such increases may preclude Mohave ground squirrels from using otherwise suitable habitat that is not directly affected by remediation activities. The Water Board’s FEIR (2013) noted that plan area construction equipment would create new sources of noise and/or vibration above existing conditions, but concluded that these effects are likely insignificant (noise) or little understood (vibration). Nighttime lighting associated with in situ, ex situ, and ATU treatment facilities could also adversely influence Mohave ground squirrel behavior distant from a facility but the exact nature of these impacts to behavior and their severity are unknown. Under Alternative 2, exterior light fixtures and standards would continue to be designed to be fully shielded, directing light downward below the horizontal plane of the fixture height. The lead biologist would confirm that lighting plans have been reviewed and that night lighting spillover has been minimized. Therefore, it is anticipated that night lighting will not result in indirect impacts to Mohave ground squirrels (same as under Alternative 1).

Groundwater Contaminants. CH2M (2016) prepared an update of the Ecological Risk Assessment for PG&E evaluating the risks of groundwater contaminant exposure via application to ATUs to listed and unlisted species (Appendix I of the HCP). No risks were identified for any receptor under current conditions and for the 20-year future scenario. Low-level risks to insectivorous avian and reptilian receptors were predicted under the shortest- and longest-timeframe future scenarios, but these risks are not significant due to low exceedance of the no observed adverse effect level and conservative assumptions used in the exposure and risk models. No risks to Mohave ground squirrels were predicted under current conditions and all future scenarios. Therefore, no adverse effects are predicted for ground squirrels exposed to these analytes under Alternative 2 (same as under Alternative 1).

Pesticides. As described for Alternative 1, PG&E has prepared an IPMP (Arcadis, 2014a) to ensure that that any proposed use of pesticides at ATUs will pose a negligible risk to wildlife species. With implementation of IPMP, it is anticipated that Mohave ground squirrel will not be impacted by project- related pesticide use under Alternative 2 (same as under Alternative 1).

Altered Predation Pressure. As described above for the desert tortoise, the increase in the abundance of common raven in the Mojave Desert also represents a predation risk to Mohave ground squirrels (USFWS, 2011b). Road-killed animals and trash may attract common ravens to an area, thereby increasing predation vulnerability to squirrels adjacent to roads. This “road-effect zone” can effectively be up to three times the size of the footprint of the road itself (USFWS, 2011b). Harris and Leitner (2005) reported that dispersing juveniles suffered apparently high predation rates (9 of 29 study animals, or 31 percent), but their study did not report species responsible for apparent predation losses. While common raven predation on Mohave ground squirrels occurs (MGSWG, 2006), the Service did not consider this a significant threat to the species (USFWS, 2011b).

As described for Alternative 1, PG&E has developed and will implement a Common Raven Management Plan to avoid and minimize potential project-related increases in predation risk to sensitive species in the plan area, including Mohave ground squirrel. PG&E will implement measures to minimize and prevent attracting predators during construction and operation and decommissioning of remediation facilities. With implementation of the approved RMP, the adverse effects of common raven predation on Mohave ground squirrel would be reduced over the 50-year permit term of the ITP. The Service also expects that management of ponded surface water, trash, debris, and other food sources (as well as measures within the RMP) will limit food subsidies to dogs and coyotes that could potentially harm or kill Mohave ground squirrels.

PG&E has also committed to participating in a regional raven management program administered by the NFWF. Participation in this program will contribute to tortoise conservation in the broader western Mojave Desert, and may provide benefits to Mohave ground squirrel which are also preyed upon by

 

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common ravens. With implementation of these measures under Alternative 2, the Service anticipates that impacts from altered predation pressure will be reduced and may be less than impacts under Alternative 1.

Invasive Plants. The proliferation of non-native plants is not included in the list of stressors that the Service (USFWS, 2011b) considered in its analysis of listing eligibility for Mohave ground squirrel.

However, the associated risk of increased wildfire recurrence in non-native vegetation types noted above for desert tortoise is also applicable to Mohave ground squirrel. Similar to Alternative 1, under Alternative 2 PG&E will ensure that any seed mixes used at restoration sites do not contain non-native species. However, under Alternative 2, the Service and CDFW will review and approve seed mixes prior to their use in the plan area, providing additional protection against the expansion of non-native plant communities. Alternative 2 also commits PG&E to ensuring that all off-road vehicles and equipment used for remediation is free and clear of weed propagules prior to their use in the plan area. With implementation of these measures, the Service expects that indirect impacts to Mohave ground squirrels from invasive plants may be reduced under Alternative 2, as compared to Alternative 1.

Climate Change. As described for Alternative 1, a warming climate in the Mojave Desert is predicted to elicit one or more of three potential responses for Mohave ground squirrel: constrict its range, transpose its range farther north, and/or move its distribution to higher elevations. Similar to Alternative 1, under Alternative 2, the Water Board’s FEIR (2013) commits PG&E to implement several MMs (AIR-MM-1 through AIR-MM-8) to mitigate greenhouse gas emissions associated with the construction, O&M, and decommissioning of the proposed project and their potential incremental contributions to climate change. With implementation of these measures, the Service does not expect that remediation activities under Alternative 2 will contribute to climate change effects and related long-term impacts to Mohave ground squirrels.

Summary

Under Alternative 2, the Service estimates that up to three Mohave ground squirrels could be killed or injured as a result of facility construction during the permit term. Additionally, it is anticipated that no more than one Mohave ground squirrel would be killed or injured by vehicle strikes on access roads or from ATU operations and maintenance during the permit term (none would be killed or injured under Alternative 1). No Mohave ground squirrels are anticipated to be killed or injured during decommissioning of facilities (same as under Alternative 1).

As described above for desert tortoise, full build-out of remediation facilities under Alternative 2 is anticipated to temporarily disturb 170 acres and permanently impact 697 acres of suitable Mohave ground squirrel habitat in the plan area. To compensate for impacts to Mohave ground squirrel habitat resulting from implementation of remediation activities, PG&E will identify, secure, and manage in- perpetuity up to 1,798 acres of suitable desert habitat at a location or locations approved by the agencies.

In addition, through implementation of the HCP and associated plans (RMP, IPMP [Arcadis. 2017a, 2041a]), the Service does not anticipate adverse effects on Mohave ground squirrels through other impact pathways.

4.3.2.3         Burrowing Owl

Impacts to Individuals

Under Alternative 2, PG&E would continue to implement its Burrowing Owl Protection Plan (Arcadis, 2014b) that includes measures to ensure the protection of burrowing owls prior to and during construction and remediation activities (same as Alternative 1). Restrictions and commitments in the Burrowing Owl Protection Plan that would be implemented under Alternative 2 are identical to those in Alternative 1. While the magnitude and locations of remediation activities under Alternative 2 are

 

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greater than those of Alternative 1, the Service anticipates that impacts to burrowing owls under Alternative 2 will be avoided through implementation of the Burrowing Owl Protection Plan (similar to Alternative 1).

Habitat Loss

Over time, development of facilities under Alternative 2 is expected to result in the temporary disturbance of approximately 268 acres of land, with a permanent footprint of 3.1 acre not including new ATUs. As described in the Burrowing Owl Protection Plan, proposed placement of project infrastructure during the planning phase will avoid historical burrowing owl burrow locations and suitable burrowing habitat within the project area whenever possible. Development of new ATUs (totaling 1,088 acres) may attract and support populations of invertebrates and small mammals, which in turn may create high quality burrowing owl foraging habitat, resulting in a long-term beneficial impact. Implementation of the Burrowing Owl Protection Plan would avoid indirect impacts to burrowing owl through disturbance or removal of their habitat (i.e., burrows) during construction and remediation activities (same as Alternative 1).

Other Impact Pathways

Edge Effects. As described for Alternative 1, facility construction, O&M, and decommissioning would increase noise, vibration, and lighting in areas adjacent to project sites. Such increases could indirectly impact burrowing owls. PG&E will continue to implement noise and vibration control measures (MM NOI-MM-1) to reduce noise and vibration. Nighttime lighting associated with new in situ, ex situ, and ATU treatment facilities could also adversely influence burrowing owl behavior distant from a facility but the exact nature of these impacts to behavior and their severity are unknown. Under Alternative 2, exterior light fixtures and standards would be designed to be fully shielded, directing light downward below the horizontal plane of the fixture height. The lead biologist would confirm that lighting plans have been reviewed and that night lighting spillover has been minimized. Therefore, it is anticipated that night lighting will not result in indirect impacts to burrowing owls (same as Alternative 1).

Groundwater Contaminants. CH2M prepared an Ecological Risk Assessment Update for PG&E (2016) evaluating the risks of groundwater contaminant exposure via application to ATUs to listed and unlisted species (Appendix I of the HCP). No risks to burrowing owls were predicted under current conditions and all future scenarios. Therefore, no adverse effects are predicted for burrowing owls exposed to these analytes under Alternative 2 (same as Alternative 1).

Pesticides. As described for Alternative 1, PG&E has prepared an IPMP (Arcadis, 2014a) to ensure that that any proposed use of pesticides at ATUs will pose a negligible risk to wildlife species. With implementation of IPMP, it is anticipated that burrowing owls will not be harmed or killed by project- related pesticide use under Alternative 2 (same as Alternative 1).

Summary

By avoiding mortality or injury during facility construction, operation, and decommissioning and minimizing the potential for adverse effects due to other impact pathways, Alternative 2 would not result in substantial adverse effects to burrowing owls. Through implementing the HCP and associated plans (Burrowing Owl Protection Plan, IPMP), it is anticipated that adverse effects on burrowing owls would be similar to those anticipated under Alternative 1.

4.3.2.4         Bald and Golden Eagle

As described for Alternative 1, suitable nesting habitat for golden eagle does not occur in the majority of the plan area, but golden eagles may forage in the plan area. Suitable nesting and foraging habitat for bald eagle does not occur in the plan area. PG&E has would implement species-specific buffers to ensure the protection of special-status migratory birds (including bald and golden eagles) prior to and during construction and remediation activities (Appendix A).

 

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With implementation of the species-specific buffers under Alternative 1, a qualified biologist would conduct a preconstruction survey in areas of potentially suitable habitat for nests and nesting bird behavior prior to the initiation of any ground disturbing or noise generating project activities between February 1 and August 31. If an active golden eagle nest is identified during the pre-construction surveys within the proposed project footprint, a standard buffer of 2,640 feet will be established around identified active golden eagle nests. Consultation with the Service would be required to work within the buffer.

Based on the Ecological Risk Assessment Update prepared for PG&E (CH2M, 2016), there are no adverse effects predicted for golden eagles exposed to arsenic, manganese, and uranium under Alternative 2.

PG&E has prepared an IPMP to be implemented for all new (and existing) ATUs (Arcadis, 2014a). The IPMP explicitly details an approach to ensure that operation of ATUs, and risks of any proposed use of herbicides, pesticides, or rodenticides will pose a negligible risk to wildlife species.

By avoiding mortality or injury during facility construction, operation, and decommissioning and minimizing the potential for adverse effects due to other impact pathways, Alternative 2 would not result in substantial adverse effects to bald and golden eagles. Through implementing the HCP and associated plans (species-specific buffers, IPMP [Arcadis, 2014a]), it is anticipated that adverse effects on bald and golden eagles would be similar to those anticipated under Alternative 1.

4.3.2.5         Other Migratory Birds

PG&E has prepared and would implement species-specific buffers to ensure the protection of nesting birds covered by the MBTA prior to and during construction and remediation activities (described above for Alternative 1).

Any intentional harassment, killing or collection of migratory birds at construction sites and surrounding areas would be prohibited.

As under Alternative 1, implementation of the species-specific buffers would avoid indirect impacts to species covered by the MBTA through disturbance or removal of their nests during construction and remediation activities.

4.3.3                        Cumulative Effects

Past, present, and reasonably foreseeable future projects that could affect biological resources in the cumulative impact assessment area are as follows:

  • SR 58 Hinkley Expressway Project— Construction of this project began in June 2015 and was completed in early 2017. Construction, operation, and maintenance of this project would result in direct and indirect impacts on special-status wildlife species within the plan area. These impacts include direct impacts from construction activities and indirect impacts from habitat fragmentation, habitat loss, and the introduction of invasive species. Measures have been incorporated into the project to avoid and/or minimize impacts to special-status wildlife species to less than significant levels.
  • Solar Projects—Construction, operation, and maintenance of these projects would cause potential special status wildlife disturbance, displacement, injury, and mortality. Indirect impacts could occur from loss and fragmentation of habitat, and the potential for increased predation on desert tortoise due to the introduction of new, elevated perching sites in the project area that might attract ravens. Where there are existing elevated perching sites for ravens, such as transmission lines and associated structures, previous studies have shown that the addition of similar elevated perching sites is not likely to result in a further increase in ravens. In addition, perching sites currently in place due to agricultural activities may be eliminated by installation of the projects, and potential impacts to desert tortoise from ravens could be avoided or minimized by implementation of a raven

 

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monitoring and control plan. These projects would not affect special status species in the same location as the PG&E proposed project, but since the population of these species extends across the western Mojave Desert, there is a potential for cumulative impacts.

  • San Bernardino County General Plan Buildout—Construction of residences and other structures associated with buildout of the County General Plan could result in direct impacts as well as loss of special-status wildlife species habitat.
  • Barstow General Plan Buildout—Construction of residences and other structures associated with buildout of the Barstow General Plan could result in direct impacts as well as loss of special-status wildlife species habitat.

Under Alternative 2, PG&E would develop and implement an HCP and the Service would issue an ITP to implement the remediation activities. The conservation program in the HCP includes approaches for avoiding and minimizing direct and indirect impacts to sensitive wildlife (covered species). The conservation program also provides for the acquisition and management of lands at an offsite conservation area for the benefit of covered species and, potentially, other sensitive resources as mitigation for unavoidable impacts to habitat for the covered species. With implementation of the conservation program, the Service believes that impacts to biological resources in the project area would not be substantial under Alternative 2. Potential impacts to biological resources are discussed below in the context of their contribution to cumulative impacts on the covered species and other wildlife species.

As described previously, under Alternative 2, PG&E will use a phased approach in implementing remediation activities over a 50-year period between 2018 and 2068. The proposed remediation activities would infringe on habitat that supports the federally protected desert tortoise and the state protected Mohave ground squirrel and could also affect several other special-status wildlife species (see Section 4.2.3, Wildlife). Some of these species would also be affected by other cumulative development.

The SR 58 Hinkley Expressway Project, which widened (from two lanes to four lanes) and rerouted an 8.9-mile section of SR 58 through the plan area (i.e., OU3 and OU1), is a joint Caltrans, FHWA, and BLM effort (Caltrans, 2013). As such, the lead cooperating federal agencies consulted with the Service for impacts to desert tortoise under Section 7 of the ESA. The non-jeopardy Biological Opinion prepared for the SR 58 project (USFWS, 2013b) estimated that up to 16 adults, 108 juveniles, and 46 eggs of desert tortoises could occur within the action area, and that up to 502 acres of suitable desert tortoise habitat could be permanently disturbed during construction of the road expansion project.

The Service concluded that the number of adults, sub adults, juveniles, and eggs that are likely to be lost comprises a small portion of the overall population in the Western Mohave Recovery Unit and that the loss would not appreciably reduce the number of desert tortoises in the recovery unit. In addition, the Service concluded that the permanent loss of approximately 502 acres of suitable habitat would not substantially reduce the reproduction, numbers, or distribution of desert tortoise in the wild and that Caltrans’ proposal to acquire 2,273 acres of habitat to manage for the conservation of the desert tortoise should contribute to its recovery (USFWS, 2013b).

For the SR 58 Hinkley Expressway Project, the Service estimated that 273 acres of suitable Mohave ground squirrel habitat could be directly affected by the SR 58 project, and that a total area of 819 acres could be affected in a “road-effect zone” (USFWS, 2011b). These acreages represent 0.01 and 0.03 percent of the range (in 2011) of the Mohave ground squirrel. A single Mohave ground squirrel individual was trapped during protocol survey efforts for this species in 2007. In total, the Service concluded that this transportation project, even when burdened with the road-effect zone, did not represent a significant threat to Mohave ground squirrel habitat or range (USFWS, 2011b).

The project environmental impact report for the SR 58 Hinkley Expressway Project (Caltrans, 2013) proposed several MMs and concluded that with their implementation, and with compensatory

 

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mitigation for unavoidable impacts to suitable habitat, incremental impacts to Mohave ground squirrel would be offset, and therefore the project would not contribute cumulatively to species effects.

It is assumed that all future projects in the project vicinity, including solar projects and new land uses from buildout of the San Bernardino County and Barstow general plans, would implement similar mitigation, thereby minimizing the severity of each respective project’s impacts on special status species. In addition, continued use of existing rural roads will contribute to a cumulative impact on desert tortoise and Mohave ground squirrel through continued mortality and injury. Road kills also supplement food sources for common ravens, which may alter predation pressure on the covered species. Vehicles using roads may transport non-native plants which, if established, may reduce food and cover resources for covered species. The magnitude of this cumulative impact is unknown.

Implementing the HCP will contribute incremental impacts to desert tortoise, Mohave ground squirrel and other special-status wildlife species, in addition to impacts related to the projects noted above.

However, the portions of the plan area where intensive remediation activities are to be implemented (i.e., OU1 and OU2) are already relatively developed and degraded. Other portions of the plan area (i.e., OU3) that include high-value desert tortoise habitat will not be substantially affected by PG&E’s remediation activities. As part of the overall conservation strategy (Chapter 5 of the HCP), PG&E will

acquire and manage in perpetuity compensatory mitigation lands at a location to be determined. Future actions on these compensatory mitigation lands will be directed to promote the conservation of desert tortoise and will benefit other wildlife species, including Mohave ground squirrel. For these reasons, it is unlikely that the incremental effects of the covered activities and conservation strategy would substantially add to cumulative impacts to special status wildlife species in the Western Mojave Desert.

 

CHAPTER 5

Water Quality

This chapter describes the regulatory setting, the affected environment for water quality, and the environmental consequences of implementing the alternatives. As described in Chapter 3, the discussion focuses on water quality impacts that may occur as a secondary consequence of the Cr(VI) remediation project.

5.1                              Regulatory Setting

The California State Water Resources Control Board (SWRCB) is the state agency with primary responsibility for implementation of state and federally established water quality regulations. In the Lahontan Region, these regulatory requirements are implemented by the Water Board. The Water Board regulates water quality in the Mojave River watershed and the Mojave River Groundwater Basin.

The federal Safe Drinking Water Act (SDWA) was passed in 1974 to protect drinking water quality. The

U.S. Environmental Protection Agency (EPA) establishes the national standards for drinking water quality. Maximum contaminant levels (MCLs) are the federal enforceable limits for contaminants in drinking water. In addition, Secondary MCLs are established to protect the public welfare and apply to contaminants in drinking water that adversely affect its odor, taste or appearance. Similar to federal requirements, the California Safe Drinking Water Act of 1996 (Health and Safety Code, Section 116365) requires the SWRCB to establish state-specific MCLs and Secondary MCLs. Federal and state MCLs and Secondary MCLs relevant to the impact analysis are listed in Table 5.1-1. The MCLs apply to PG&E’s requirement to provide replacement water supplies pursuant to Mitigation Measure WTR-MM-2 in the Water Board’s FEIR (2013).

The Porter-Cologne Water Quality Control Act (1967) is the primary law governing California’s water quality regulations. Under this act, the state is required to adopt a water quality control policy to be implemented by the SWRCB and nine regional boards. The SWRCB also approves water quality control plans (basin plans) prepared by the regional boards. Basin plans designate beneficial uses for specific surface water and groundwater resources and establish water quality objectives to protect those uses. Some objectives are narrative, but many are quantitative with specific limits for constituents in various surface streams or specified groundwater basins.

The Basin Plan for the Lahontan Region is the basis for the regional board’s regulatory program. It sets forth water quality standards for the surface and groundwater of the region, which include both designated beneficial uses of water and the narrative and numerical objectives that must be maintained to protect those uses. The 1995 Lahontan Basin Plan includes beneficial uses and water quality objectives for groundwater (Water Board, 1995). The plan area is located in the middle reach of the Mojave River Groundwater Basin. The beneficial uses for this basin are:

  • Municipal and domestic supply (MUN)
  • Agricultural supply (AGR)
  • Industrial service supply (IND)
  • Freshwater replenishment (FRSH)
  • Aquaculture (AQUA)

Narrative and numerical water quality standards have been established for protection of these uses. The most sensitive use is municipal and domestic supply.

 

 

 

 

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Table 5-1. Maximum Contaminant Levels

 

Constituent

 

Primary MCL Federal

 

Primary MCL State

Secondary MCL Federal

 

Secondary MCL State

Arsenic

0.010 ppm

0.010 ppm

NA

NA

Iron

NA

NA

0.3 ppm

0.3 ppm

Manganese

NA

NA

0.05 ppm

0.05 ppm

Uranium

30 ppb

20 pCi/L

NA

NA

Gross Alpha

15 pCi/L

15 pCi/L

NA

NA

Gross Beta

4 pCi/L

4 pCi/L

NA

NA

TDS

NA

NA

500 ppm

500 ppm recommended

1,000 ppm upper limit

1,500 ppm

short-term upper limit

Nitrate (as nitrogen)

10 ppm

10 ppm

NA

NA

Source: CCR Title 22, Chapter 15, Article 16; EPA, 2017; SWRCB, 2016. Notes:

NA = none adopted ppm = parts per million

pCi/L = picocuries per liter TDS = total dissolved solids

There are no groundwater quality objectives established specifically for the Mojave River Groundwater Basin. Water quality objectives that apply to all the Lahontan Region’s groundwater basins, as specified in the Lahontan Basin Plan (Water Board, 1995), are shown in Table 5-2.

 

Table 5-2. Groundwater Quality Objectives for Groundwater Basins in the Lahontan Region

Constituent

Concentration

Bacteria, Coliform

In groundwater designated as MUN, the median concentration of coliform organisms over any 7-day period shall be less than 1.1 per 100 milliliters.

Chemical Constituents

Groundwater designated as MUN shall not contain concentrations of chemical constituents in excess of the MCL or Secondary MCL. Groundwater designated as AGR shall not contain concentrations of chemical constituents in amounts that adversely affect the water for beneficial uses (i.e., agricultural purposes).

Radioactivity

Groundwater designated as MUN shall not contain concentrations of radionuclides in excess of the limits specified in Table 4 of Section 64443 (Radioactivity) of CCR Title 22.

Taste and Odor

Groundwater shall not contain taste- or odor-producing substances in concentrations that cause nuisance or that adversely affect beneficial uses. For groundwater designated as MUN, concentrations shall not exceed Secondary MCLs.

 

 

5.2                              Affected Environment

Information on chemical constituents is from the Water Board’s FEIR (2013).

 

 

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5.2.1                        Total Dissolved Solids


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“Total dissolved solids” is the term used to describe the inorganic salts and small amounts of organic matter present in solution in water. The principal constituents are calcium, magnesium, sodium, potassium, carbonate, hydrogen carbonate, chloride, sulfate, and nitrate. Historical agricultural land uses have increased the salt (TDS) concentrations in the groundwater below irrigated and agricultural lands in the Hinkley Valley. While natural dissolution of salts from geologic materials (i.e., aquifer sediments) does occur as the water moves from the Mojave River toward the north, such concentrations are significantly less than that contributed by irrigated lands, dairy and other animal operations.

TDS data was collected in the initial two years of the current ATU project under the WDRs as part of an investigation required by mitigation measure WTR-MM-5. The TDS data from the investigation indicate that along the chromium plume, TDS concentrations range from less than 400 ppm to 7,900 ppm roughly on a south to north gradient (PG&E, 2011; CH2M, 2015). TDS concentrations increase starting at the Compressor Station in the south to Salinas Road in the north. The increasing concentrations are due to agricultural activities and other animal operations (Water Board, 2013). Some of the greatest nitrate and TDS concentrations in the Hinkley Valley are present in the currently farmed Northern ATU areas, because of decades of consistent previous agricultural land use and livestock operations (CH2M 2015). Outside of the chromium plume within the Hinkley Valley, TDS concentrations are above recommended secondary MCL of 500 milligrams per liter (mg/L) for TDS and closely associated with areas that have undergone historical or recent agricultural and/or dairy/livestock operation (CH2M, 2015).

5.2.2                        Uranium and Other Radionuclides

Uranium, a radionuclide, is a naturally occurring radioactive element in rocks, soil, water, plants, animals and humans. Uranium is typically measured in pCi/L. A curie is a standard unit of radioactivity, where 1 curie is the radioactivity associated with 1 gram of radium. A picocurie is one trillionth (10-12) of a curie. However, uranium is also expressed in ppm, and thus both units may be used in discussing uranium concentrations. The average concentration of uranium is on the order of 2.7 ppm in the Earth’s crust (Skeppstrom and Olofsson, 2007).

Naturally occurring uranium (approximately 4 ppm) has been found in rocks in a number of locations in the Mojave Desert (USGS, 2008). Uranium and other naturally occurring radioactive materials have been detected in Mojave River Groundwater Basin and are likely attributed to the mineralogy of the granitic rocks observed in the lower regional aquifer (Churchill, 1991). Uranium in sediments leaches into groundwater in oxidizing environments, but is more strongly adsorbed in mineral complexes under anaerobic (oxygen-poor) conditions.

Besides uranium, gross alpha has also been detected in Hinkley Valley groundwater. Gross alpha refers to a group of radionuclides, in which radium is usually a main constituent. The alpha radiation in drinking water can be in the form of dissolved minerals, or in the case of radon, as a gas. Like uranium, gross alpha is measured in pCi/L. Alpha radiation is a type of energy released when certain radioactive elements (such as uranium or radon) decay or break down. Alpha radiation normally exists everywhere: in soil, in the air, and in water. Gross beta is another group of radionuclides that has been detected in Hinkley Valley groundwater. Like alpha particles, beta particles are naturally occurring products associated with the decay of certain radioactive elements.

In response to Water Board orders, PG&E submitted several reports summarizing the presence of uranium and gross alpha and gross beta in groundwater prior to PG&E operation of ATUs:

  • Radionuclide Data Summary Report on November 30, 2012
  • Southern Agricultural Treatment Unit Water Quality submitted on February 25, 2015 (Arcadis 2015).

 

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  • Agricultural Treatment Byproducts Investigation Report for Environment Impact Report Mitigation Measure WTR-MM-5 (WTR-MM-5 Report) submitted on June 30, 2015 (CH2M, 2015)

The data summarized in these reports indicated that uranium and gross alpha are present in groundwater at concentrations above drinking water standards throughout much of the Hinkley Valley. Gross beta is present, but at concentrations that are well below drinking water standards. The WTR- MM-5 Report contained data collected from an investigation required by mitigation measure WTR-MM- 5 during the first two years of the project. Specifically, the Upper Aquifer uranium data was summarized, as follows:

  • Concentrations as high as 100 pCi/L have been reported at one well in the eastern Hinkley Valley. Other wells have levels above the state MCL of 20 pCi/L in eastern Hinkley Valley, with a few wells containing concentrations above 50 pCi/L.
  • In the Southern ATU areas, most wells contain uranium above the state MCL, with a maximum of 43 pCi/L.
  • Concentrations above 100 pCi/L were reported for numerous wells in the Northern ATUs, with a maximum concentration of 150 pCi/L. Almost all wells in this area contained concentrations above the state MCL of 20 pCi/L. Concentrations decrease north of Thompson Road.
  • The presence of generally low dissolved uranium concentrations was found in western Hinkley Valley and north of Thompson Road, compared with central and eastern Hinkley Valley.
  • Dissolved uranium was detected above the 20 pCi/L MCL in at least one sampling event in nine domestic wells.

Gross alpha data showed the following in comparison to the 15 pCi/L MCL:

  • Concentrations as high as 106 pCi/L have been reported in eastern Hinkley Valley.
  • In the Southern ATU areas, a concentration of 52.1 pCi/L was detected.
  • Concentrations above 50 pCi/L were reported for numerous wells in the Northern ATUs, with a maximum concentration of 226 pCi/L.

PG&E data on freshwater supply wells located upgradient (south) of the chromium plume and of the IRZ and ATUs had total uranium levels up to 4.1 pCi/L, up to 8.5 pCi/L for gross alpha, and up to 23.3 pCi/L for gross beta. These concentrations are less than the corresponding MCLs. Lower aquifer monitoring wells had dissolved uranium levels from 1 to 2 pCi/L, 3 to 4 pCi/L for gross alpha, and less than 4 to 5 pCi/L for gross beta (PG&E, 2012a). In addition, the USGS sampled domestic wells as part of the background Study in January of 2016 and reported that uranium concentrations exceeded the EPA MCL of 30 ppb in 6 of 72 wells in the Hinkley Valley, with a maximum concentration of 62 ppb (USGS, 2016).

5.2.3                        Nitrate

Nitrates and nitrites are formed through the decomposition of organic materials in soil, which release ammonia. This ammonia oxidizes to form nitrate and nitrite; nitrate is more common. The primary beneficial use of nitrates is as a fertilizer used to add nutrients to crops. Often, excess nitrate resides in the soil of agricultural fields following fertilizer application. Nitrate can percolate with irrigation water or precipitation to reach groundwater. Irrigation with high nitrate water pumped from agricultural wells provides nutrients for crops, and therefore helps remove nitrate from the water supply. However, since crop irrigation is typically seasonal, nitrate plumes will migrate with natural groundwater flow during periods of non-irrigation and affect other beneficial uses, such as domestic and municipal wells and agricultural wells for confined animals.

 

 

 

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The background nitrate concentrations in groundwater in the Hinkley Valley are generally less than a few ppm. Outside of the chromium plume, large portions of the east Hinkley Valley (east of Summerset Road) are above the state MCL of 10 mg/L as nitrogen, with a maximum concentration of 34 ppm as nitrogen (CH2M, 2015). The distribution of nitrate exceeding the state is closely associated with areas that have undergone historical or recent agricultural and/or dairy/livestock operations.

Around the chromium plume, nitrate concentration in groundwater, like TDS, is highest between SR 58 and Salinas Road. Nitrate in this area has been detected up to 201 ppm as nitrogen, greatly exceeding the 10 ppm MCL (CH2M, 2015). Nitrate pollution has been detected in residential wells at and north of the Desert View Dairy. In addition, USGS sampled domestic wells as part of the Background Study in January of 2016 and reported that nitrate concentrations exceeded the EPA MCL of 10 mg/L ppm as nitrogen (USGS, 2016).

5.2.4                        Arsenic

Arsenic is a naturally occurring element in the Earth's crust and is widely distributed in the environment. USGS conducted sampling for various constituents in wells in the Mojave Water Agency management area from 1991 to 1997, including wells in the Hinkley area (Christensen, 2001). Naturally occurring arsenic concentrations in water from wells in the western Mojave Desert commonly exceed 10 ppb and a few exceed 100 ppb. Along the Mojave River upgradient of the PG&E Compressor Station, the study found arsenic in wells (up to 200 feet in depth) ranging from less than 1 ppb to 12 ppb with most concentrations under 10 ppb. In the Hinkley area, within approximately 0.5 mile of SR 58, the study found concentrations of arsenic in three wells ranging from 3 ppb to 12 ppb. Approximately 1 to 2 miles north of SR 58, the study found arsenic in two wells ranging from less than 1 ppb to 2 ppb.

Approximately 4 miles north of SR 58, the study found arsenic in one well at a concentration of 52 ppb. While the USGS study was conducted after the release of chromium from the Hinkley Compressor Station, sampling occurred before the use of carbon-amendment injections to groundwater, and thus reflects levels prior to in situ treatment.

As described in the 2010 Feasibility Study (PG&E, 2010), pilot and extended-scale in situ remediation of the chromium plume has resulted in temporary and localized increase of arsenic concentrations in parts of the plume area. Based on experience with in situ treatment, arsenic (and other byproducts) concentration increases in correlation to the amount of injected organic carbon and then decreases in time as the organic carbon is consumed by microbial action. Elevated arsenic (up to 290 ppb) due to IRZ operations is found in the immediate vicinity of IRZ carbon injection locations (Arcadis, 2017b).

Downgradient of the IRZ area, arsenic concentrations above the regulatory reference level of 13 ppb are generally limited to within 200 feet and attenuate with distance, although arsenic above 13 ppb was detected between 400 and 800 feet downgradient in two cases. In all cases, wells further away from the injection locations show much lower concentrations (typically below 1 ppb) (Arcadis, 2017b). Wells upgradient of the PG&E Compressor Station that are outside the zone of influence of IRZ operations have yielded arsenic levels between 1 and 61 ppb (CH2M and Arcadis, 2011). In addition, the USGS sampled domestic wells as part of the Background Study in January of 2016 and reported that arsenic concentrations exceeded the EPA MCL of 10 ppb in 28 of 72 wells in the Hinkley Valley with a maximum concentration of 300 ppb (USGS, 2016). It can be shown that arsenic levels in the IRZ area are declining back to pre-IRZ reference levels within the IRZ treatment area within the chromium plume area.

5.2.5                        Iron

Iron is the second most abundant metal in the Earth’s crust, and accounts for about 5 percent of the mass of the Earth’s crust. The 2007 Background Study Report (PG&E, 2007) found dissolved iron levels in 47 wells at less than 500 ppb (the method detection level was 500 ppb).

 

 

 

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Elevated iron (up to 42.9 mg/L) due to IRZ operations is found in the immediate vicinity of IRZ carbon injection locations (Arcadis, 2017b). Downgradient of the IRZ area, iron concentrations above the regulatory reference level of 471 ppb are generally limited to within 800 feet of the injection area and attenuate with distance, although iron was detected up to 1,600 feet downgradient in a few instances (Arcadis, 2017b). In all cases, wells further away from the injection locations show much lower concentrations (typically below the detection limit of 20 ppb) (Arcadis, 2017b). Current data shows iron as by product only within the 3.1 ppb chromium plume contour south of SR 58 and not beyond the plume boundaries.

5.2.6                        Manganese

Manganese is a naturally occurring element that is common in the air, soil, and water. In addition to natural sources, manganese levels can also be influenced by anthropogenic sources, such as dairy runoff, leaking septic tanks, or individual well fouling. The 2007 Background Study Report (PG&E, 2007) found dissolved manganese levels in areas outside the defined chromium plume to range from less than 1 ppb (method detection level of 1 ppb) up to 48 ppb. Five out of 47 wells sampled had one or more detections of manganese greater than 10 ppb.

PG&E tested manganese levels in the IRZ area prior to initiating IRZ testing and operations and found manganese levels to range up to a maximum of 210 ppb in the Central Area of IRZ operations (PG&E, 2012b). Elevated manganese (up to 13.8 mg/L) due to IRZ operations is found in the immediate vicinity of IRZ carbon injection locations (Arcadis, 2017b). Downgradient of the IRZ area, manganese concentrations above the regulatory reference level of 260 ppb are generally limited to within 800 feet of the injection area and attenuate with distance, although manganese was detected 1,600 feet downgradient in one area (Arcadis, 2017b). In all cases, wells further away from the injection locations show much lower concentrations (typically below the detection limit of 0.5 ppb) (Arcadis, 2017b).

Concentration trend data demonstrate that manganese attenuates with time when carbon amendments cease (PG&E 2010).

Manganese was detected in domestic wells located west of the chromium plume in samples collected by the Water Board at concentrations up to 789 ppb (Water Board, 2013; Arcadis, 2013).

5.3                              Environmental Consequences

This section describes potential direct, indirect, and cumulative impacts to water quality that may result from implementation of remediation alternatives over the planned remediation period (50 years, generally through 2068). As described in Chapter 3, both alternatives would reduce chromium contamination in the groundwater aquifer relative to existing conditions, which would be a beneficial effect on the environment, although the scale and time to full remediation are different for each alternative.

5.3.1                        Alternative 1: No Action

The Water Board studied several potential adverse water quality impacts that could result from chromium remediation (Water Board, 2013). In many cases, the Water Board determined that other potential types of groundwater quality impacts would be less than significant. The Water Board did, however, determine that there may be temporary, localized impacts associated with chromium plume spreading (or “bulging”) that would occur during remediation. The Water Board also investigated water quality changes associated with remediation activities, and determined that there could be increased concentrations of other constituents such as total dissolved solids, secondary byproducts of remediation (e.g., arsenic, iron, manganese), nitrate, and uranium. Specifically, the following potentially significant impacts were identified:

 

 

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  • Impact WTR-2d: temporary localized chromium plume expansion due to remedial actions (i.e., plume "bulging")
  • Impact WTR-2e: Increase in Total Dissolved Solids, Uranium, and Other Radionuclides due to Agricultural Treatment
  • Impact WTR-2f: Changes in Nitrate Levels due to Agricultural Treatment
  • Impact WTR-2g: Increase in Other Secondary Byproducts (Dissolved Arsenic, Iron and Manganese) due to In-Situ Remediation

5.3.1.1         Plume Expansion

Remediation activities are intended to stop the spreading of the chromium plume and reduce concentrations in the drinking water aquifer. The long-term benefit of remediation would be a reduction of the chromium plume to background levels and restoration of beneficial uses. However, remedial activities could cause the temporary spreading (referred to as “bulging”) of the chromium beyond existing plume boundaries through freshwater injection and in situ treatment. The CAO allows for the lateral migration of the 4 ppb Cr(VI) eastern plume boundary in the southern plume to no more than 1,000 feet, provided PG&E contains chromium from migrating to the north.

With continued operation of the in situ treatment systems, temporary localized chromium plume bulging in the upper aquifer is expected occur in limited areas. Groundwater modeling of injection and extraction rates did not indicate increased potential for plume bulging with remediation, given the balance of injection and extraction rates. However, as operations are adapted over time to accomplish remediation, greater injection rates than extraction rates may occur within localized areas, and potentially create conditions for localized plume bulging. Any potential for plume bulging, however, would remain within the limits established by the CAO.

It is unlikely that water supply wells would be substantially impacted through plume expansion as a result of remediation activities under Alternative 1. In addition to following the CAO limits, PG&E would continue to implement avoidance measures (mitigation measures) identified in the Water Board’s FEIR (2013). Continued implementation of MM WTR-MM-2: provision of alternative water supply to affected wells, as necessary and MM WTR-MM-3: enhancement and maintenance of hydraulic control and plume water balance, would ensure that Alternative 1 would not result in substantial adverse effects to water quality in the plan area.

5.3.1.2         Total Dissolved Solids, Uranium, and Other Radionuclides

The continued use of AT could result in increased TDS in the water that infiltrates back to the aquifer below the irrigated land as a result of increased concentrations of TDS in the root zone due to evaporation. This would worsen existing high TDS levels, which are a result of agricultural land uses in the plan area including farmland irrigation and confined animal operations. MM WTR-MM-5 in the Water Board’s FEIR required investigation and monitoring of TDS levels to identify pre-remedial reference conditions and where and when remedial actions result in significant impacts for determining when replacement water and/or aquifer restoration are warranted. The initial investigation pursuant to MM WTR-MM-5 is complete, and preliminary information shows that AT is not contributing to increased TDS levels (CH2M, 2015). MM WTR-MM-2 requires alternative water supplies for all affected or potentially affected wells, and MM WTR-MM-4 requires restoration of the drinking water aquifer from all substantial water quality impairments resulting from remedial activity in a timely manner. These monitoring requirements have been incorporated into the waste discharge requirements (WDRs) for the ATUs (Order No. R6V-2014-0023). In addition, Order No. R6V-2014-0023 requires that PG&E develop and implement an action plan for TDS control if monitoring shows that TDS concentrations increase by 20 percent above background levels. With implementation of these measures, water quality impacts would not be significant.

 

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Uranium and other radionuclides are naturally occurring in Mojave Desert soils and rocks. PG&E’s AT operations could further mobilize uranium and other radionuclides, but the possibility of uranium and other radionuclide contact with the human environment appears to be minimal. The monitoring requirements of the Water Board’s FEIR (2013) have been incorporated into Order No. R6V-2014-0023, which also requires that PG&E implement an action plan if statistically significant concentrations of uranium are detected. PG&E has been implementing its monitoring program with no detection of uranium or other radionuclides in existing domestic wells attributable to the remediation project.

Although there are no institutional controls that prohibit the drilling of new privately owned drinking water wells, PG&E owns the vast majority of the property within the vicinity of the remedial systems where remediation byproduct generation and migration is anticipated. PG&E will not install any drinking water wells on the properties that they own where there is any potential to encounter uranium or other radionuclides. Additionally, if any new drinking water wells are drilled on non-PG&E-owned property, they would be subject to all of the mitigation measures described above and therefore there is a minimal chance of contact with uranium or other radionuclides. With implementation of these mitigation measures, water quality impacts would not be significant.

5.3.1.3         Nitrate

AT has the potential to reduce the nitrate concentration in the aquifer when the applied water is taken up by crops as nutrients. This would improve the existing high nitrate levels in the plan area, which are a result of agricultural land uses (primarily dairy operations).

There is, however, potential for localized nitrate increases to occur due to movement of water during remediation. MM WTR-MM-6 in the Water Board’s FEIR requires investigation and monitoring of nitrate levels to identify reference conditions and current nitrate levels. This will continue under Alternative 1. MM WTR-MM-2 requires alternative water supplies for all affected or potentially affected wells, and MM WTR-MM-4 requires restoration of the drinking water aquifer from all substantial water quality impairments resulting from remedial activity in a timely manner. In addition, Order No. R6V-2014-0023 requires that PG&E develop and implement a contingency plan if monitoring shows that nitrate concentrations increase above background levels, including incorporation of MM WTR-MM-6. Given the expected benefit, and with continued implementation of these measures, water quality impacts would not be significant.

5.3.1.4         Byproduct Metals

In situ treatment may result in temporary mobilization of byproduct metals – arsenic, manganese, and iron – naturally present in aquifer soils, resulting in a localized increase in the concentration of dissolved arsenic, manganese, and iron in groundwater. Temporary and localized degradation of the aquifer near carbon amendment injection points is unavoidable where in situ remediation is employed.

Eight years of data demonstrates that these byproduct metals are being mobilized within the IRZ, but they are attenuated downgradient of the facilities. Manganese has been shown to travel the furthest, while iron and arsenic migration is much more limited. In situ treatment byproducts are found only within the footprint of treated water and on PG&E property. Monitoring has shown that concentrations of remedial byproducts return to pre-injection levels as the injected carbon is consumed by microbial processes or is attenuated through oxidation and sorption downgradient of the IRZ.

In situ treatment byproducts are tracked by intensive monitoring conducted by PG&E required under the in situ permit. Groundwater monitoring is required quarterly to ensure that the byproducts are not migrating outside the boundaries established in the permit. If concentrations are found to be migrating past a network of sentry wells, rapid implementation of an action plan to ensure capture of the byproducts is required. To date, groundwater monitoring has shown that these byproducts generated by the remediation project have been contained within the current network of sentry wells.

 

 

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Additional groundwater monitoring of byproducts is required specifically to ensure that byproducts are not migrating toward domestic wells under MM WTR-MM-2. In the event that increasing byproduct concentrations above significance criteria are detected within 0.5 mile upgradient or 0.25 mile cross gradient of a domestic well, PG&E will alter the remediation to ensure that the byproducts will not migrate to the domestic well, or replacement water will be provided. To date no domestic wells have been found to be affected by byproducts resulting from the remediation.

As described above for uranium, the possibility of contact of in situ byproducts such as arsenic and manganese with the human environment is minimal. The mitigation measures and monitoring requirements of the Water Board’s FEIR (2013) reduces the potential for exposure to groundwater constituents. With PG&E’s continued implementation of these requirements, water quality impacts associated with in situ byproducts would not be substantial.

5.3.2                        Alternative 2: PG&E’s Proposed Hinkley Groundwater Remedy HCP

5.3.2.1         Plume Expansion

Remediation activities are intended to stop the spreading of the chromium plume and reduce concentrations in the drinking water aquifer. The long-term benefit of remediation would be a reduction of the chromium plume to background levels and restoration of beneficial uses. Under Alternative 2, the time period to full remediation of the chromium plume would be shorter. However, as described above for Alternative 1, remedial activities could cause temporary “bulging” of the chromium plume beyond existing plume boundaries through freshwater injection and in situ treatment.

With the proposed expansion of in situ treatment, additional chromium plume bulging in the upper aquifer could occur in limited areas compared to Alternative 1. However, this effect would be temporary and localized. Remediation activities under Alternative 2 would continue to be controlled by the CAO, which allows for limited plume expansion as described under Alternative 1. In addition, PG&E would continue to implement avoidance measures (mitigation measures) identified in the Water Board’s FEIR (2013). As under Alternative 1, provision of alternative water supply to affected wells, as necessary (MM WTR-MM-2) and enhancement and maintenance of hydraulic control and plume water balance (MM WTR-MM-3) would ensure that Alternative 2 would not result in substantial adverse effects to water supply wells. As under Alternative 1, this impact would be temporary as all areas with chromium above background levels, whether due to the original chromium plume or due to remedial actions, would be remediated to background levels. Therefore, this impact would not be significant.

5.3.2.2         Total Dissolved Solids, Uranium, and Other Radionuclides

Expanded AT under Alternative 2 could lead to increased TDS in the water that infiltrates back to the aquifer. As under Alternative 1, PG&E would continue to monitor TDS levels to determine where and when remedial actions result in significant impacts to water supply wells or the aquifer (MM WTR-

MM-5). MM WTR-MM-2 requires alternative water supplies for all affected or potentially affected wells and control of byproduct plumes where feasible. MM WTR-MM-4 requires restoration of the drinking water aquifer from all substantial water quality impairments resulting from remedial activity in a timely manner. In addition, the CAO requirements for TDS monitoring and action plan implementation would apply under Alternative 2. With implementation of these mitigation measures, water quality impacts would not be significant (same as Alternative 1).

Expanded AT under Alternative 2 could lead to increased mobilization of uranium or other radionuclides. Under Alternative 2, PG&E would continue to monitor concentrations of uranium and other radionuclides in local wells and the water applied to ATUs, and if necessary implement an action plan to limit uranium increases.

The possibility of contact of uranium and other radionuclides with the human environment is minimal. The monitoring requirements of the Water Board’s FEIR (2013) and Order No. R6V-2014-0023 (also

 

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under Alternative 1) serve to protect domestic wells and reduce the potential for exposure to groundwater constituents. PG&E has been successfully implementing these measures with no detection of uranium or other radionuclides in existing domestic wells attributable to the remediation project.

Therefore, implementation of Alternative 2 will not have a significant effect on water quality (same as Alternative 1).

Under Alternative 2, PG&E will not install any drinking water wells on the properties that they own where there is any potential to encounter uranium or other radionuclides. Additionally, if any new drinking water wells are drilled on non-PG&E-owned property, they would be subject to all of the mitigation measures described above and therefore there is a minimal chance that humans will come into contact with uranium or other radionuclides. With implementation of these measures, water quality impacts would not be significant (same as Alternative 1).

5.3.2.3         Nitrate

As described above for Alternative 1, AT has the potential to reduce the nitrate concentration in the aquifer when the applied water is taken up by crops as nutrients. The expansion of AT under

Alternative 2 is anticipated to further support a reduction in nitrate concentrations in the plan area over time. The overall effect of AT will be removal of nitrate from groundwater, which will be a beneficial effect for the aquifer as a whole.

There is, however, potential for localized nitrate increases to occur due to movement of water during remediation. This potential impact to local parts of the aquifer will be addressed through continued implementation of mitigation measures that involve monitoring nitrate levels and managing AT to avoid significant increases, as prescribed in the Water Board’s FEIR and in Order No. R6V-2014-023. Given the expected benefit, and with continued implementation of these measures, water quality impacts would not be significant (similar to Alternative 1).

5.3.2.4         Byproduct Metals

As described above for Alternative 1, in situ treatment may result in a short-term increase in the concentration of dissolved arsenic, manganese, and iron in groundwater. Temporary and localized degradation of the aquifer near carbon amendment injection points is unavoidable where in situ treatment is employed. As described for Alternative 1, byproducts metals are tracked by intensive monitoring conducted by PG&E and eight years of data demonstrates the generation of byproduct metals within the IRZ and attenuation downgradient of the facilities.

Order No. R6V-2008-0014 specifies that groundwater concentrations of byproducts outside the chromium plume area shall not exceed water quality standards due to remedial operations. Order No. R6V-2008-0014 and the IRZ Notice of Applicability dated April 20, 2014 specify the contingency plan for IRZ byproducts and require implementation of mitigation measure WTR-MM-2 to protect domestic wells and reduce the potential for exposure to groundwater constituents.

As described above for uranium, the possibility of contact of in situ treatment byproducts such as arsenic and manganese with the human environment is minimal. The mitigation measures and monitoring requirements of the Water Board’s FEIR (2013) (also under Alternative 1) serve to protect domestic wells and reduce the potential for exposure to groundwater constituents. PG&E has been successfully implementing these measures since their adoption into existing permits with no detection of byproducts in existing domestic wells attributable to the remediation project. With PG&E’s continued implementation of these requirements, water quality impacts associated with in situ treatment byproducts would not be significant (same as Alternative 1).

 

 

 

 

 

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5.3.3                        Cumulative Effects


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Past, present, and reasonably foreseeable future projects that could affect local water quality in the Hinkley Valley and northeast part of Harper Valley are as follows:

  • San Bernardino County General Plan Buildout
  • Barstow General Plan Buildout

The remedial actions under Alternative 2 would reduce chromium contamination in the groundwater aquifer relative to existing conditions, which would be a beneficial effect on the environment. While the remediation project would reduce chromium contamination, certain remediation activities have the potential to adversely impact water quality. However, with implementation of mitigation measures, water quality impacts to water supply wells and the long-term beneficial uses of the aquifer would not be substantial. Potential changes in water quality are discussed below in the context of their contribution to cumulative water quality impacts.

5.3.3.1         Total Dissolved Solids, Uranium, and Other Radionuclides

Dairy operations and irrigated agriculture are the major cause of increased TDS in the Hinkley Valley groundwater, although natural dissolution of salts from the geologic materials (i.e., aquifer sediments) does occur as water moves from the Mojave River toward the north. Expanded AT under Alternative 2 could lead to increased TDS in the water that infiltrates back to the aquifer below the irrigated land as a result of increased concentrations of TDS in the root zone due to evaporation. Buildout under the San Bernardino County and Barstow general plans could have an effect on TDS concentrations in the aquifer if new dairies or irrigated agriculture were to result in contributions of TDS to the groundwater. Thus, there is a potential for a cumulative impact related to TDS concentrations.

As described in above, MM WTR-MM-2 would require alternative water supplies for all significantly affected wells, and MM WTR-MM-4 would require long-term remediation of increased TDS levels due to remediation actions that exceed preremedial reference levels. Implementation of Alternative 2 will not result in substantial impacts to water supply wells and the long-term beneficial uses of the aquifer would not be substantial. Therefore, Alternative 2 would not contribute to a substantial cumulative water quality impact due to changes in TDS concentrations.

Expanded AT under Alternative 2 could lead to increased concentrations of uranium or other radionuclides in the water that infiltrates back to the aquifer below the irrigated land. Together with other, non-PG&E pumping for agricultural irrigation or buildout of the San Bernardino County and/or Barstow general plans, there is a potential for cumulative changes in groundwater concentrations of uranium and other radionuclides.

Under Alternative 2, PG&E would continue to monitor concentrations of uranium and other radionuclides in local wells and the water applied to ATUs. The mitigation measures and monitoring requirements of the Water Board’s FEIR (2013) would continue to be implemented. Therefore, implementation of Alternative 2 would not contribute to a substantial cumulative water quality impact due to changes in groundwater concentrations of uranium and other radionuclides.

5.3.3.2         Nitrate

Agricultural treatment has the potential to reduce the nitrate concentration in the aquifer when the applied nitrate water is taken up by crops as nutrients. The expansion of AT under Alternative 2 is anticipated to reduce nitrate concentrations in the expanded area over time. The overall effect of AT will be removal of nitrate from groundwater, which will be a beneficial effect for the aquifer as a whole.

Buildout under the San Bernardino County and Barstow general plans could have an effect on nitrate concentrations in the aquifer if new dairies were to result in contributions of nitrate to the groundwater. Thus, there is a potential for a cumulative impact related to TDS concentrations. However, the expected

 

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reduction in nitrate ensures that Alternative 2 would not have a substantial cumulative water quality impact.

5.3.3.3         Byproduct Metals

None of the cumulative projects are likely to result in increased concentrations of iron, manganese or arsenic in groundwater. Additional growth pursuant to the San Bernardino County and Barstow general plans (including residential, agricultural, and other uses) is not likely to result in new uses that would result in groundwater contamination by iron, manganese and arsenic. However, as described above, in situ treatment may result in a short-term increase in the concentration of dissolved arsenic, manganese, and iron in groundwater. Temporary and localized degradation of the aquifer near carbon amendment injection points is unavoidable where in situ treatment is used.

As described above, impacts to water supply associated with dissolved iron, manganese and arsenic can be mitigated through MMs WTR-MM-2 (alternative water supply) and WTR-MM-4 (remediation of byproduct plumes). As described above for uranium, the mitigation measures and monitoring requirements of the Water Board’s FEIR (2013) are incorporated into the WDRs for the ATUs (R6V-2014- 0023) and the Notice of Applicability for the IRZs and the Freshwater Injection System (under R6V-2008- 2014). With PG&E’s continued implementation of these requirements, water quality impacts associated with in situ treatment byproducts would not be substantial. Therefore, implementation of Alternative 2 would not contribute to a substantial cumulative water quality impact.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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CHAPTER 6

Cultural Resources

This chapter describes the existing cultural resources within the plan area, including archaeological and historical resources, and evaluates environmental consequences of implementing the proposed action. Information in this chapter is based heavily on the Water Board’s FEIR (2013).

6.1                              Regulatory Setting

The National Historic Preservation Act (NHPA) was enacted in 1966 to encourage the preservation and wise use of the country’s historic resources. As amended, the NHPA sets forth national policy and procedures for historic properties, defined to include “the protection, rehabilitation, restoration, and reconstruction of districts, sites, buildings, structures, and objects significant in American history, architecture, archaeology, or culture” included in or eligible for listing in the National Register of Historic Places (NRHP). The eligibility criteria for the NRHP are quoted in full as follows:

The quality of significant in American history, architecture, archeology, engineering, and culture is present in districts, sites, buildings, structures, and objects that possess integrity of location, design, setting, materials, workmanship, feeling, and association, and:

  1. That are associated with events that have made a significant contribution to the broad patterns of our history
  2. That are associated with the lives of significant persons in our past
  3. That embody the distinctive characteristics of a type, period, or methods of construction, or that represent the work of a master, or that possess high artistic values, or that represent a significant and distinguishable entity whose components may lack individual distinction
  4. That have yielded or may be likely to yield, information important in history or prehistory

Resources that meet the criteria and are either listed or have been determined eligible for NRHP listing are also considered under Section 106 of the NHPA. Section 106 of the NHPA requires federal agencies to consider the effects of their undertakings on historic properties following regulations issued by the Advisory Council on Historic Preservation (36 CFR 800).

6.2                              Affected Environment

The Hinkley Valley was inhabited by the Vanyume, one of two large divisions of the Serrano tribe that inhabited the surrounding central Mojave Desert region, the San Bernardino Mountains, and other surrounding areas during the late eighteenth and nineteenth century (Water Board, 2013; Applied Earthworks, 2014). The majority of Vanyume settlements were along the Mojave River, and they seasonally traveled to collect food, hunt, and trade products with the Serrano (Water Board, 2013). In addition to the Vanyume, other groups like the Mountain Serrano, Chemehuevi, Desert Kawaiisu, and the Mojave would interact near the lower Mojave River Valley and adjacent areas. Two ethnohistoric village sites were also identified in the vicinity of Hinkley Valley, at Newberry Springs and in the Barstow- Daggett area (Applied Earthworks, 2014).

Studies for the remediation project identified one site with extensive surface and subsurface features that was determined eligible for listing on the NRHP – a Native American village site adjacent to the

 

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Mojave River (Water Board, 2013). The site is within the plan area, but at the far southern end and not in an area expected to be subject to remediation activities.

The decade of the 1880s marked the first period of rapid population growth in the Mojave River Valley, driven mostly by the expansion of railroad service. Settlement of the Hinkley Valley began in the early 20th century, including farmers, railroad workers, miners, and ranchers (Water Board, 2013). The Hinkley Valley area went through stages of settlement, growth, and expansion as an established farming community, with a decline in population from the 1990s to the present. In the 1950s, PG&E began developing its large compressor station in southeastern Hinkley Valley – the largest of three facilities along PG&E’s “Super Inch” California pipeline, which was designed to bring natural gas from Texas to California (Water Board, 2013).

Studies for the remediation project identified one historic architectural resource that was determined eligible for listing on the NRHP – a segment of the Atchison, Topeka & Santa Fe Railroad (Water Board, 2013). This active railroad line (now part of the BNSF Railway railroad system) is within the plan area, but would not be affected by remediation activities.

A cultural resources survey report was prepared by Applied Earthworks in 2014 summarizing the methods and results of the cultural resources investigation prepared for PG&E in the plan area. The study investigated a total of 1,369 acres of both PG&E and privately owned land within the plan area (Applied Earthworks, 2014). The survey of various parcels in the plan area identified 76 cultural resources; of the 76 cultural resources, 64 are archaeological sites and 12 are isolated localities of prehistoric artifacts (Applied Earthworks, 2014). Within the 64 archaeological sites are 40 historical sites, 17 prehistoric sites, and 7 sites that contain both prehistoric and historical components (Applied Earthworks, 2014). While each site was evaluated for significance, only five sites were recommended as potentially significant and therefore eligible for listing in the California Register of Historic Resources.

The five identified sites are listed as follows:

  • CA-SBR-16138. A prehistoric lithic scatter with debitage, a quartzite mano fragment, and fire- affected rocks.
  • CA-SBR-16802. A prehistoric site containing the remains of two hearths or roasting features, one milling slab, and scattered fire-affected rocks.
  • CA-SBR-16811. A prehistoric site containing three scatters of fire-affected rocks and one hearth or roasting feature.
  • CA-SBR-17245. A prehistoric artifact scatter with 49 lithic debitage pieces, seven ground stone tools, two flaked stone tools, and one roasting pit.
  • CA-SBR-17246. A prehistoric habitation with three intact roasting pits and four rhyolite boulders with milling slick surfaces.

The remaining 59 archaeological sites and 12 isolated artifact localities were determined to not be potentially significant or eligible for California Register of Historic Resources listing.

6.3                              Environmental Consequences

6.3.1                        Alternative 1: No Action

PG&E is obligated to conduct remediation activities under a CAO from the Water Board, and all remediation actions would adhere to the strict CMs from the Water Board’s FEIR. The following summarizes MMs and activities that would be implemented under Alternative 1 that would reduce impacts to cultural resources (Water Board, 2013).

  • MM CUL-MM-1: Determine Presence of Historical Resources as Defined by CEQA

 

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  • MM CUL-MM-2: Avoid Damage to Historical Resources Located in Project Areas through Project Modification
  • MM CUL-MM-3: Record Historical Resources
  • MM CUL-MM-4: Conduct an Archaeological Resources Survey to Determine if Historical Resources under CEQA or Unique Archaeological Resources under Public Resources Code Section 21083.2 are Present in Proposed Areas of Disturbance
  • MM CUL-MM-5: Avoid Damaging Archaeological Resources through Redesign of Specific Project Elements or Project Modification
  • MM CUL-MM-6: Evaluate Archaeological Resources and, if Necessary, Develop and Implement a Recovery Plan
  • MM CUL-MM-7: Comply with State and County Procedures for the Treatment of Human Remains Discoveries

Site-specific preconstruction cultural resources studies are required for all remediation projects to determine the potential presence of historical resources (MM CUL-MM-1) or archaeological resources (MM CUL-MM-4). Avoidance measures CUL-MM-2 and CUL-MM-5 require the submittal of documentation to the Water Board prior to construction (and to BLM for federal lands). MMMs CUL- MM-3 and CUL-MM-6 require more extensive coordination with the Water Board to demonstrate compliance, and both measures prescribe specific protocols to document and record cultural resources prior to construction.

Under Alternative 1, PG&E would continue to implement these MMs in the areas where remediation activities occur.

6.3.2                        Alternative 2: PG&E’s Proposed Hinkley Groundwater Remedy HCP

Under Alternative 2, the Service would issue an ITP to implement the Covered Activities, and PG&E would implement its proposed HCP. Pursuant to the Water Board’s FEIR, PG&E would continue its existing program for avoiding and minimizing cultural resources impacts consistent with the seven MMs listed under Alternative 1.

Issuing an ITP would allow PG&E to access additional areas to construct and operate remediation projects. This expanded remediation area is primarily Natural/Undisturbed and Disturbed lands that contain desert tortoise habitat, and that also may contain cultural resource sites. Site-specific cultural resources studies continue to be required prior to any remediation project construction, as required by MMs CUL-MM-1 and CUL-MM-4.

As described previously, Applied EarthWorks (2014) studied portions of this area and determined that five out of the 76 sites examined were potentially significant and therefore eligible for listing. By following the Water Board’s FEIR MMs, these five sites could be avoided (MMs CUL-MM-2 and CUL- MM-5), or could be developed for remediation if avoidance is determined to be infeasible (MMs CUL- MM-3 and CUL-MM-6).

As a result of the NHPA Section 106 consultation process, PG&E has committed to avoid significant cultural sites (potential historic properties) consistent with MMs CUL-MM-2 and CUL-MM-5. So although Alternative 2 would allow access to a larger area for remediation, Alternative 2 would not result in greater impacts to significant cultural sites and there would be no effect to significant cultural sites in the expanded remediation area.

 

 

 

 

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6.3.3                        Cumulative Effects

Potential cultural resource impacts will be evaluated on a site by site basis, with CMs consistent with MMs CUL-MM-1 through CUL-MM-7 from the Water Board’s FEIR (2013). In addition, under Alternative 2 there would be no increase in impacts to significant cultural sites compared to Alternative 1. Because of the site-specific nature of review, there would be no cumulative impacts.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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CHAPTER 7

Environmental Justice

7.1                              Regulatory Setting

Executive Order (EO) 12898, issued by President Clinton in 1994, states “…each Federal agency shall make achieving environmental justice part of its mission by identifying and addressing, as appropriate, disproportionately high and adverse human health or environmental effects of its programs, policies, and activities on minority and low-income populations….” In his memorandum transmitting EO 12898 to federal agencies, President Clinton further specified that “…each Federal agency shall analyze the environmental effects, including human health, economic and social effects, of Federal actions, including effects on minority communities and low-income communities, when such analysis is required by the National Environmental Policy Act of 1969” (Federal Register, 1994). Guidance on how to implement

EO 12898 and conduct an environmental justice analysis was issued by the CEQ in 1997. Additional considerations in environmental justice analysis have been developed by the EPA’s Environmental Justice program.

7.2                              Affected Environment

The presence of a minority and low income population in the plan area was determined using the 2010 Census data (U.S. Census Bureau, 2016) and the 2011-2015 American Community Survey (ACS) 5-year data (U.S. Census Bureau, 2017a). Minority and income data were reviewed at the finest level available from the Census: Census Block Group for minority and Census Tract for income. A demographic analysis was conducted to determine whether an environmental justice population exists within the plan area.

The minority populations addressed by EO 12898 are individuals who are members of the following population groups: American Indian or Alaskan Native; Asian or Pacific Islander; Black, not of Hispanic Origin; or Hispanic. According to the CEQ’s Environmental Justice Guidance under the NEPA, “minority populations should be identified where either (a) the minority population of the affected area exceeds 50 percent or (b) the minority population percentage of the affected area is meaningfully greater than the minority population percentage in the general population or other appropriate unit of geographical analysis.” Based on part (a) of the CEQ guidance, the population just south of the plan area meets this definition: it is 57 percent minority (Figure 7-1) with a majority of this population identifying as Hispanic/Latino (U.S. Census Bureau, 2016).

EPA defines “low income” as the percent of a Census Block Group’s population in households where the household income is less than or equal to twice the federal poverty level (EPA, 2016). The current federal poverty level for a household of four people is $24,339 (U.S. Census Bureau, 2017b). Therefore, using the EPA definition, a low-income population may exist based on the percentage of the population in households with income of less than approximately $50,000. In the plan area, the American Community Survey 5-year estimates for 2011-2015 showed between 43 and 65 percent of the population in households with income of less than $50,000 (Figure 7-2) (U.S. Census Bureau, 2017a).

This is higher than the regional and statewide average of 36 percent (EPA, 2015).

Based on this analysis of demographic indicators, an environmental justice community exists within the plan area.

 

 

 

 

 

 

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7.3                              Environmental Consequences

This section describes potential direct, indirect, and cumulative impacts to the environmental justice community. The federal guidelines set forth the following three-step screening process to evaluate environmental justice impacts:

  • Identify which impacts of the project, if any, are high and adverse. High and adverse impacts are the same as significant impacts.
  • Determine whether an environmental justice community exists within the high and adverse impact zones.
  • Examine the spatial distribution of high and adverse impact areas to determine whether these impacts are likely to fall disproportionately on the minority and/or low-income population

7.3.1                        Alternative 1: No Action

Based on environmental analysis in the Water Board’s FEIR (2013) and in this EA, there are no significant impacts remaining after mitigation measures are implemented. Because there are no significant impacts, there are no high and adverse human health and environmental impacts that are likely to fall disproportionately on the environmental justice community. Therefore, there would be no impact.

7.3.2                        Alternative 2: PG&E’s Proposed Hinkley Groundwater Remedy HCP

Under Alternative 2, PG&E would implement its remediation program in the same manner and within the same area as Alternative 1. Based on environmental analysis in the Water Board’s FEIR (2013) and in this EA, there are no significant impacts remaining after mitigation measures are implemented. Because there are no significant impacts, there are no high and adverse human health and environmental impacts that are likely to fall disproportionately on the environmental justice community. Therefore, there would be no impact.

7.3.3                        Cumulative Effects

Because there are no significant impacts remaining after mitigation measures are implemented that could potentially fall disproportionately on the environmental justice community, there are no cumulative environmental justice impacts.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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CHAPTER 8

List of Preparers

8.1                              U.S. Fish and Wildlife Service

Scott Hoffman, Project Manager Carol Roberts, Senior Biologist

John Robles, NEPA and Section 106 Compliance

8.2                              CH2M HILL Engineers, Inc.

Catherine Burrell, Environmental Planner

David Christophel, Quality Assurance/Quality Control Review Matt Franck, Project Manager

Neil Nikirk, Environmental Scientist Yassaman Sarvian, Environmental Planner Katie Schwartz, Technical Editor

 

CHAPTER 9

References

Applied Earthworks. 2014. Cultural and paleontological resource studies for the Pacific Gas & Electric Groundwater Remediation Project, Hinkley Compressor Station, San Bernardino County, California. Volume 1: Cultural resources survey of portions of operable units (OUs) 1, 2, and 3.

Arcadis U.S., Inc. (Arcadis). 2013. Manganese Investigation Technical Report Response to Board Orders No. R6V-2012-0060 and R6V-2013-0026. Pacific Gas & Electric, Hinkley Compressor Station. November 19.

Arcadis U.S., Inc. (Arcadis). 2014a. Integrated Pest Management and Adaptive Management Plan. Hinkley Compressor Station, San Bernardino County, California. Prepared for Pacific Gas & Electric Company. April.

Arcadis U.S., Inc. (Arcadis). 2014b. Burrowing Owl Protection Plan. Hinkley Compressor Station, San Bernardino County, California. Prepared for Pacific Gas & Electric Company. April.

Arcadis U.S., Inc. (Arcadis). 2015. Southern Agricultural Treatment Unit Water Quality. Hinkley Compressor Station, Hinkley, California. Prepared for Pacific Gas &Electric Company. February.

Arcadis U.S., Inc. (Arcadis). 2017a. Common Raven Management Plan – Revision 1. Hinkley Compressor Station, San Bernardino County, California. Prepared for Pacific Gas & Electric Company. January 2017.

Arcadis U.S., Inc. (Arcadis). 2017b. First Quarter 2017 Monitoring Report for the In Situ Reactive Zone and Northwest Freshwater Injection Projects. Hinkley Compressor Station, Hinkley, California. April.

Barrows, C.W. 2011. “Sensitivity to climate change for two reptiles at the Mojave-Sonoran Desert interface.” Journal of Arid Environments. 75: 629-635.

Breakiron, Heather, Environmental biologist, Transcon. 2016. Personal communication (email) to Jeff Tupen, CH2M. February 10.

Buehler, David A. (2000). “Bald Eagle (Haliaeetus leucocephalus), The Birds of North America” (P. G. Rodewald, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America: https://birdsna.org/Species-Account/bna/species/baleag. DOI: 10.2173/bna.506

California Department of Transportation (Caltrans). 2013. Final Environmental Impact Report/Environmental Impact Statement for the State Route 58 (SR-58) Hinkley Expressway Project. San Bernardino County, California. Caltrans District 8-SBD-SR-58 (PM 22.2/31.1). EA 08-043510. PN 0800000010.

California Department of Fish and Wildlife (CDFW). 2016. California Natural Diversity Database. October 1. Accessed October 21, 2016. https://www.wildlife.ca.gov/Data/CNDDB.

California Regional Water Quality Control Board, Lahontan Region (Water Board). 1995. Water Quality Control Plan for the Lahontan Region. Plan effective March 31, 1995, with amendments effective August 1995 through September 10, 2015. http://www.waterboards.ca.gov/lahontan/water_issues/programs/basin_plan/references.shtml.

California Regional Water Quality Control Board, Lahontan Region (Water Board). 2013. Final Environmental Impact Report. Comprehensive Groundwater Cleanup Strategy for Historical Chromium Discharges from PG&E's Hinkley Compressor Station, San Bernardino County. May. http://www.swrcb.ca.gov/rwqcb6/water_issues/projects/pge/index.shtml.

California Regional Water Quality Control Board, Lahontan Region (Water Board). 2014. Waste Discharge Requirements for Pacific Gas and Electric Company Groundwater Remediation Project

 

EN1010161105SAC                                                                                                                                                                               9-1

 

CHAPTER 9 REFERENCES

 

Agricultural Treatment Units, WDID No. 6B361403002. Board Order No. R6V-2014-0023. California Water Board, Lahontan Region. March 12.

California State Water Resources Control Board (SWRCB). 2016. MCLs, DLRs, and PHGs for Regulated Drinking Water Contaminants. Updated September 29, 2016. Downloaded from Comparison of MCLs and PHGs for Regulated Contaminants in Drinking Water web page. Accessed March 22, 2017. http://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/MCLsandPHGs.shtml.

Council on Environmental Quality (CEQ). 1997. Environmental Justice Guidance Under the National Environmental Policy Act. Council on Environmental Quality, Executive Office of the President, Washington, DC. December 10. Released July 1998.

CH2M HILL Engineers, Inc. (CH2M) and Arcadis U.S., Inc. (Arcadis). 2011. Fourth Quarter 2010 Monitoring Report for the In-Situ Reactive Zone and Northwest Freshwater Injection Projects. PG&E Hinkley Compressor Station. Hinkley, California. January 14.

CH2M HILL Engineers, Inc. (CH2M). 2015. Agricultural Treatment Byproducts Investigation Report for Environment Impact Report Mitigation Measure WTR-MM-5, Pacific Gas and Electric Company, Hinkley Compressor Station, Hinkley, California. 2015.

CH2M HILL Engineers, Inc. (CH2M). 2016. Technical Memorandum: Pacific Gas & Electric Hinkley Site - Update of the 1988 Ecological Risk Assessment. January. Prepared by Christine Arenal and Harry Ohlendorf.

Christensen, A. H. 2001. Concentrations for Total Dissolved Solids, Arsenic, Boron, Fluoride, and Nitrite- Nitrate for Wells Sampled in the Mojave Water Agency Management Area, California, 1991–97. U.S. Geological Survey. Open-File Report 01-084.

Churchill, R. 1991. “Geologic controls on the distribution of radon in California.” California Department of Health Services. 41 p.

City of Barstow. 2016. Planning. Accessed October 20, 2016. http://www.barstowca.org/city-hall/city- departments/planning.

Esque, T.C., K.E. Nussear, R.D. Inman, M.D. Matocq, P.J. Weisberg, T.E. Dilts, and P. Leitner. 2013. Habitat Modeling, Landscape Genetics and Habitat Connectivity for the Mohave Ground Squirrel to Guide Renewable Energy Development. California Energy Commission. Publication Number: CEC-500- 2014-003. 165 pp.

Harris, J.H. and P. Leitner. 2005. Long-distance movements of juvenile Mohave ground squirrels, Spermophilus mohavensis. The Southwestern Naturalist 50: 188-196.

ICF International. 2014. San Bernardino County Regional Greenhouse Gas Reduction Plan. Final. March. (ICF 00543.12.) San Francisco, CA. Prepared for San Bernardino Associated Governments, San Bernardino, California.

Leitner, P. and M.D. Matocq. 2015. Status of the Mohave ground squirrel in the Hinkley area, San Bernardino County, California. Final Report. Prepared for CH2M. November 10, 2015.

Lovich, J.E., C.B. Yackulic, J. Freilich, M. Agha, M. Austin, K.P. Meyer, T.R. Arundel, J. Hansen, M.S. Vamstad, and S.A. Root. 2014. “Climate variation and tortoise survival: Has a desert species met its match?” Biological Conservation. 169: 214-224.

Mohave Desert Air Quality Management District (MDAQMD). 1995. Final Mojave Desert Planning Area Federal Particulate Matter (PM10) Attainment Plan. July 31, 1995.

Mohave Desert Air Quality Management District (MDAQMD). 2008. Federal 8-Hour Ozone Attainment Plan (Western Mojave Desert Non-attainment Area). Adopted June 9, 2008.

 

 

9-2                                                                                                                                                                                EN1010161105SAC

 

CHAPTER 9 REFERENCES

 

Mohave Ground Squirrel Work Group (MGSWG). 2006. Draft Mohave ground squirrel conservation strategy. Unpublished report. August 29.

Nussear, K.E., T.C. Esque, R.D. Inman, L. Gass, K.A. Thomas, C.S.A. Wallace, J.B. Blainey, D.M. Miller, and

R.H. Webb. 2009. Modeling habitat of the desert tortoise (Gopherus agassizii) in the Mojave and parts of the Sonoran deserts of California, Nevada, Utah, and Arizona: U.S. Geological Survey Open-File Report 2009-1102. 18 p.

Pacific Gas and Electric Company (PG&E). 2007. Groundwater Background Study Report, Hinkley Compressor Station, Hinkley California. Prepared by CH2M HILL. February 28.

Pacific Gas and Electric Company (PG&E). 2010. Feasibility Study, Pacific Gas and Electric Company Hinkley Compressor Station, Hinkley, California. August 1. Main report prepared by Haley & Aldrich. Appendices prepared by Haley & Aldrich, CH2M HILL, and Arcadis. http://www.swrcb.ca.gov/rwqcb6/water_issues/projects/pge/index.shtml.

Pacific Gas and Electric Company (PG&E). 2011. Fourth Quarter 2011 (1) Monitoring Report for the In- Situ Reactive Zone and Northwest Freshwater Injection Projects; (2) (October 1 to December 31) Monitoring Report for Desert View Dairy Land Treatment Unit; (3) Groundwater Monitoring Report and Domestic Well Sampling Results Site-Wide Groundwater Monitoring Program; (4) Agricultural Units Monitoring Report; PG&E Hinkley Compressor Station, Hinkley, California. Prepared by CH2M HILL and Arcadis. Accessed in 2012. http://geotracker.waterboards.ca.gov/profile_report.asp?global_id=SL0607111288&mytab=esidata.

Pacific Gas and Electric Company (PG&E). 2012a. Response to Investigation Order No. R6V-2012-0057, Request for Uranium and Gross Alpha Beta Radiation Data, Pacific Gas and Electric Company, Hinkley Compressor Station, Hinkley, California. November 30.

Pacific Gas and Electric Company (PG&E). 2012b. Response to November 1 5, 2012 California Regional Water Quality Control Board, Lahontan Region Request for Data and Information on Metals in Hinkley, CA Wells. November 26. Prepared by CH2M HILL.

San Bernardino County. 2007. San Bernardino County General Plan. Prepared for the County of San Bernardino Land Use Services Division. Final draft. Prepared by URS Corporation. Adopted March 2007.

San Bernardino County. 2016. Solar Projects List. Renewable Energy Projects as of December 15, 2016. Land Use Services/Planning Division

Shrum, Mike, Environmental Biologist, Transon. 2016. Personal communication (email). Jeff Tupen (CH2M). February 8.

Skeppstrom, K. and Olofsson, B. 2007. “Uranium and Radon in Groundwater; An overview of the problem.” European Water 17/18: 51-62. Department of Land and Water Resources Engineering. Royal Institute of Technology. Stockholm, Sweden.

Sundance Biology, Inc. (SBI). 2013. Presence/absence survey for the desert tortoise (Gopherus agassizii) and other sensitive wildlife on the Comprehensive Groundwater Cleanup Strategy for Historical Chromium Discharges from Pacific Gas and Electric (PG&E)’s Hinkley Compressor Station Project, San Bernardino County, California. June 30.

Transcon Environmental, Inc. (Transcon). 2013. Personal Communication (email) to Marjorie Eisert, CH2M. December 13.

U.S. Bureau of Land Management (BLM). 2014. Harper Dry Lake fact sheet. Accessed on May 14, 2014. http://www.blm.gov/ca/st/en/fo/barstow/harper.print.html.

U.S. Census Bureau. 2016. 2010 Redistricting Data SF (PL 94-171) – Hispanic or Latino, and Not Hispanic or Latino By Race. Accessed November 2. Internet site: https://factfinders.census.gov.

 

9-3

 

CHAPTER 9 REFERENCES

 

U.S. Census Bureau. 2017a. 2011-2015 American Community Survey (ACS) 5-Year Estimates – Household Income in the Past 12 Months. Accessed June 23. https://factfinder.census.gov.

U.S. Census Bureau. 2017b. Preliminary Estimates of Weighted Average Poverty Levels for 2016. Accessed June 26. https://www.census.gov/topics/income-poverty/poverty.

U.S. Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry (ATSDR). 2016. Toxic substances portal: chromium. Accessed May 5, 2016. http://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=17.

U.S. Environmental Protection Agency (EPA). 2015. EJSCREEN. Accessed June 23, 2017. https://www.epa.gov/ejscreen.

U.S. Environmental Protection Agency (EPA). 2016. EJSCREEN Technical Documentation.

U.S. Environmental Protection Agency (EPA). 2017. Secondary Drinking Water Standards: Guidance for Nuisance Chemicals. Accessed March 22, 2017. https://www.epa.gov/dwstandardsregulations/secondary-drinking-water-standards-guidance-nuisance- chemicals.

U.S. Fish and Wildlife Service (USFWS). 1994. Desert Tortoise (Mojave Population) Recovery Plan. Prepared for Regions 1, 2 and 6 of the Fish and Wildlife Service, Portland, OR. 63 pp. plus appendices. June.

U.S. Fish and Wildlife Service (USFWS). 2008a. Authorizations under the Bald and Golden Eagle Protection Act for Take of Eagles. Federal Register 73:29075-29084. Department of the Interior, Fish and Wildlife Service, 50 CFR parts 13 and 22. Final Rule.

U.S. Fish and Wildlife Service (USFWS). 2008b. Final Environmental Assessment to Implement a Desert Tortoise Recovery Plan Task: Reduce common raven predation on the desert tortoise. U.S. Department of the Interior, Fish and Wildlife Service. Ventura, California. March.

U.S. Fish and Wildlife Service (USFWS). 2009. Desert Tortoise Field Manual. December. https://www.fws.gov/nevada/desert_tortoise/documents/field_manual/Desert-Tortoise-Field- Manual.pdf.

U.S. Fish and Wildlife Service (USFWS). 2010. Mojave population of the Desert Tortoise (Gopherus agassizii) 5-year review: summary and evaluation. U.S. Fish and Wildlife Service, Pacific Southwest Region. Sacramento, California. September 30.

U.S. Fish and Wildlife Service (USFWS). 2011a. Revised recovery plan for the Mojave population of the desert tortoise (Gopherus agassizii). Region 8, Pacific Southwest Region. U.S. Fish and Wildlife Service, Sacramento, California. May 6.

U.S. Fish and Wildlife Service (USFWS). 2011b. Endangered and threatened wildlife and plants; 12-month finding on a petition to list the Mohave ground squirrel as endangered or threatened. Federal Register 76: 62214-62258. Department of the Interior, Fish and Wildlife Service, 50 CFR Part 17. Proposed Rule.

U.S. Fish and Wildlife Service (USFWS). 2013a. General provisions; Revised list of migratory birds. Federal Register 78: 65844-65864. Department of the Interior, Fish and Wildlife Service, 50 CFR parts 10 and 21. Final Rule.

U.S. Fish and Wildlife Service (USFWS). 2013b. Biological Opinion for the SR-58 Realignment and Widening Project, San Bernardino County, California (8-8-13-F-15). Ventura Fish and Wildlife Office. March 29, 2013.

U.S. Fish and Wildlife Service (USFWS) and National Marine Fisheries Service (NMFS). 1996. Habitat Conservation Planning and Incidental Take Permit Processing Handbook. November 4.

 

 

9-4                                                                                                                                                                                EN1010161105SAC

 

CHAPTER 9 REFERENCES

 

U.S. Geological Survey (USGS). 2008. Chromium, Chromium Isotopes and Selected Trace Elements, Western Mojave Desert, USA.

U.S. Geological Survey (USGS). 2016. Letter from Dr. John Izbicki to the Hinkley Independent Review Panel Manager. September 15.

Vanherweg, W.J. 2012. Pacific Gas & Electric Hinkley groundwater remediation project. Mohave/round- tailed ground squirrel trapping results. Prepared for CH2M. August.

Vanherweg, W.J. 2013. 2013 Pacific Gas & Electric Hinkley groundwater remediation project. Protocol Mohave/round-tailed ground squirrel trapping results. Prepared for CH2M. August.

Western Regional Climate Center. 2017. Climate summary for Barstow, California from 1980-2016.

Accessed February 21, 2017. www.wrcc.dri.edu

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

9-5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figures

 

 

 

 

 

 

 

Black Mountain

#

 

 

 

 

 

 

HCP Plan Area

 

 

 

 

 

Lynx Cat Mountain#                     #Red Hill

 

 

 

 

UV58


 

Hinkley


Mount General

#

 

 

 

 

 

 

Iron Mountain

#


 

Community Blvd


 

58

 

 

 

UV58


 

 

Barstow

Rimrock Rd


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Santa Ana


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110


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UV74

 

±

0            2            4

 

 

Miles


 

FIGURE 1-1 PROJECT LOCATION

U.S. FISH AND WILDLIFE SERVICE

HINKLEY HCP ENVIRONMENTAL ASSESSMENT HINKLEY, CALIFORNIA

 

 

 

 

 

Legend

Operable Unit 1 (OU1)

 

Operable Unit 2 (OU2)

 

Operable Unit 3 (OU3)

Cr[VI] Plume (Dashed where inferred)

4th Quarter, 2016, 3.1 ppb

 

 

 

 

rass Hopper

BN Ranch


 

4th Quarter, 2016, 10 ppb

 

4th Quarter, 2016, 50 ppb

 

 

 

Halsted Rd

 

 

Sunset Rd

 

Roy Rd                                                                                             Mountain General Rd

 

 

 

 

Red Hill

 

 

 

Mountain

 

 

Salinas Rd

Palma Rd

 

Sonoma St Tindall Rd


 

 

 

 

Mount General

 

 

 

 

Alcudia Rd

Park Ave

 

Acacia St

 

Acacia St

 

State Highway 58

Kinski Rd

 

Carson Rd Granada Rd

 

Frontier Rd

 
   

PG&E Hinkley Compressor Station

s Rd

Highcres

 

Riverview Rd

 

Agate Rd

 

La Mour Rd

 

 

±

0                   1                   2

 

 

Miles


Ave


 

 

 

 

FIGURE 2-1 PLAN AREA

U.S. FISH AND WILDLIFE SERVICE

HINKLEY HCP ENVIRONMENTAL ASSESSMENT HINKLEY, CALIFORNIA

 

 

 

Legend

!(        Groundwater Monitoring Well

")

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rass H           !(!(!(

 

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Hinkley


Agate Rd

 

 

La Mour Rd


Compressor Station

 

±

0                   1                   2

 

 

Miles


 

 Ave                        


 

 

 

 

 

FIGURE 2-2 MONITORING WELLS

U.S. FISH AND WILDLIFE SERVICE

HINKLEY HCP ENVIRONMENTAL ASSESSMENT HINKLEY, CALIFORNIA

 

 

 

 

Tindall Rd


 

Legend

 

n

y  o n

R

d

 

"/    Existing ATU Extraction Well

Salinas Rd

 

!(    Existing Freshwater Extraction Well

 

 

 

 

 

"/

 

 

 

 

Gorman-"/ North


A@    Existing Freshwater Injection Well Operable Unit 1 (OU1)

Operable Unit 2 (OU2) Operable Unit 3 (OU3)

Thompson Rd

 

Existing Agricultural Treatment Units (ATU)

Estimated Future ATU Area

 

 

Hinkley Elementary School


/"/

Gorman- South / /

Alcudia  Rd "/   /         /

 

/

 

DVD West /


"/

/

Cottrell "/

/              /"

 

Field


 

/     / /


"/    /"

"/

 

Acacia St

 

"/

 

A@         "/

/

 

A@                    /"

A@


West DVD

"/    Pivot

/"

/"

"/


 

/

East DVD Pivot

/"


Yang   "/


 

Acacia St

 

 

/

"/                A@

A@A@              /

A@            "/


"/

 

Ranch


 

 

 

 

State Highway 58

 

 

 

 

 

 

      

 

Granada Rd

 

/

/ /

Fairview

 

 

 

Area ofInterest


/"

"/ "/ "/ "/ "/

Community

/"     East

Community Blv

 

 

Aquarius Rd

 

 

 

Highcrest Rd

 

/  "//"/"//" /"   "/

 

/       "/  /"


PG&E Hinkley Compressor Station

 

 

 

 

 

 

 

 

(! (!

 

 

 

±


 

 

 

 

 

 

Riverview Rd

 

FIGURE 2-3 TREATMENT AREAS


(!((!(

 

0           0.25          0.5

 

Miles


U.S. FISH AND WILDLIFE SERVICE

HINKLEY HCP ENVIRONMENTAL ASSESSMENT HINKLEY, CALIFORNIA

 

 

 

 

Tindall Rd

 

 
   

 

 
   

Legend

X Existing In Situ Treatment Well Access Routes

Operable Unit 1 (OU1) Operable Unit 2 (OU2)

Operable Unit 3 (OU3)

Potential Future Ex Situ Treatment Facility

Thompson Rd

 

In Situ Reactive Zone (IRZ)

 

 

 

 

 

 

Alcudia Rd

 

 

 

 

 

Acacia St

 

Acacia St

 

 

 

 

 

State Highway 58

 

 

 

 

 

Carson Rd

 

Frontier Rd

 

XXXXXXXXXXXXXXXXX

 

Granada Rd

 

X      X X XXXXXX

XXX XXXXX X X X X

Aquarius Rd

 

XXXXXXXX XXX

Riverview Rd

 

X

 

XXXXX


 

 

 

Area ofInterest

 

 

 

 

 

PG&E Hinkley Compressor Station

 

±

0           0.25          0.5

 

 

Miles


 

 

 

 

 

FIGURE 2-4

IN SITU AND EX SITU TREATMENT

U.S. FISH AND WILDLIFE SERVICE

HINKLEY HCP ENVIRONMENTAL ASSESSMENT HINKLEY, CALIFORNIA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

r a s s   H o p p e r

 

 

BN Ra n ch


Legend

Operable Unit 1 (OU1) Operable Unit 2 (OU2) Operable Unit 3 (OU3)

HCP Plan Area region

within which Biological Monitors may conduct desert tortoise clearance surveys

Land Cover Category

Natural/Undisturbed Disturbed Urban/Agriculture

 

 

Ha lsted R d


Data source:

SBI (2013) and Nussear et al. (2009).

 

 

 

Su n se t R d

 

 

Ro y Rd                                                                                                                                                        Mo un ta in Ge n era l R d

 

 

 

 

Re d Hill

 

 

 

 

Mo un ta in Ge n era l R d

 

 

Sonom a S t

 

Tindall R d

 

 

Salinas R d

 

Mo un t Ge n er al

 

 

 

 

 

Alcudi a R d

 

Pa rk Av e

 

 

Acacia S t

 

Acacia S t

 

 

State  Highway 58

 

 

 

 

 

r Rd

 

 

 

 

 

n t ie

 

 

 

 

 

Fro

 

Community B lvd

 

    Kinski Rd

 
   

 

 

 

 

 

 

s R d

 

Highcrest R d

 

Rivervi ew Rd

 

Ag a te R d

 

 

 

 

 

La Mour Rd


PG&E Hinkley Compressor Station

 

 

 

 

 

±

 

FIGURE 2-5

GEOGRAPHIC REGION WITHIN THE PLAN AREA WHERE


Copyright:© 2014 Esri

 

 

 

0                   1                   2

 

 

Miles


DESERT TORTOISE CLEARANCE SURVEYS MAY BE PERFORMED

BY BIOLOGICAL MONITORS RATHER THAN BY AUTHORIZED BIOLOGISTS

U.S. FISH AND WILDLIFE SERVICE

HINKLEY HCP ENVIRONMENTAL ASSESSMENT HINKLEY, CALIFORNIA

 

 

 

Legend

Study Area

Census Block Group Boundary

Minority Percentage

0-25%

 

25-50%

 

50-75%

 

 

 

060710116001

34.32%


 

75-100%

 

Census Data:

2010 ACS 5 Year Estimates, DEC_2010_PL_P2

 

 

 

 

 

 

 

 

 

 

 

Red Hill


 

060710119003

45.18%

 

 

 

 

 

 

 

060710119001

45.24%


 

 

 

Mount General

 

 

 

 

 

 

 

 

 

 

 

 

 

PG&E Hinkley Compressor Station

 

 

060710119002

47.62%

 

 

 

 

±           FIGURE 7-1


 

 

060710118001

57.48%

 

0                   1                   2

 

 

Miles


MINORITY PERCENTAGE BY CENSUS BLOCK GROUP

U.S. FISH AND WILDLIFE SERVICE

HINKLEY HCP ENVIRONMENTAL ASSESSMENT HINKLEY, CALIFORNIA

 

 

 

 

 

Legend

Study Area

Census Block Group Boundary

Low Income Percentage

0-25%

 

25-50%

 

50-75%

 

 

 

060710116001

46%


 

75-100%

 

Census Data:

2015 ACS 5 Year Estimates B19001

 

 

 

 

 

 

 

 

 

 

 

Red Hill


 

060710119003

43%

 

 

 

 

 

 

 

060710119001

66%


 

 

 

Mount General

 

 

 

 

 

 

 

 

 

 

 

 

 

PG&E Hinkley Compressor Station

 

 

 

±         FIGURE 7-2


060710119002

48%


 

 

060710118001

57%

 

0                   1                   2

 

 

Miles


LOW INCOME PERCENTAGE BY CENSUS BLOCK GROUP

U.S. FISH AND WILDLIFE SERVICE

HINKLEY HCP ENVIRONMENTAL ASSESSMENT HINKLEY, CALIFORNIA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Appendix A

Nesting Birds: Species-Specific Buffers

for PG&E Activities

 

Nesting Birds:  Species-Specific Buffers

for PG&E Activities

 

 

Within PG&E’s Avian Program, standard nest buffers were developed for all common and

special-status birds present within its Service Territory.  There are no standard nest buffers specified in the Migratory Bird Treaty Act (MBTA) or within California Fish and Game Code. Table 1 provides nest buffers based on the best available information, including relevant literature review and avian biology. Disturbance factors including nest location, human activity, activity duration, and noise level may influence nesting behavior and reproductive success, and were each considered in establishing standard buffer distances for individual species. Where regulatory agencies have provided information on nest buffer distances for special-status species, those buffer distances are primarily used as standard buffers in Table 1. Standard buffers are species-specific buffer distances between occupied nest sites and work activities where work will not occur while the nest is active (containing eggs or young). These standard buffers are intended to be applied to nests located in proximity to PG&E activities at a sufficient distance to provide suitable nest protection. For example, a nesting black-crowned night heron has a standard buffer distance of 400 feet (Table 1).

 

Because it is not always possible to apply the standard buffer, non-standard species- specific buffer distances have also been established. As part of the determination of these non-standard buffers, PG&E activities are assigned disturbance rankings (Low, Medium, or High) for each factor identified above. Evaluation of all disturbance factors combined produces an overall disturbance category by assessing each disturbance factor for one or more PG&E activities. If the overall disturbance category is high, the standard buffer will generally apply. If the evaluation results in low or medium overall disturbance categories, the standard buffer is applied as feasible or reduced buffers may be appropriate. For example, in some circumstances it may be necessary to perform certain types of work within the standard buffer. In these cases, biologists consider all relevant site-specific conditions, including the species’ tolerance for disturbance, work activity type, noise levels, and distance to nest to determine if reducing the standard buffer is appropriate.

Alternatively, the buffer may be increased beyond the standard buffer for certain exceptions. Helicopters are the main exception that may require increased buffers.

 

Pacific Gas and Electric Company                                                                                                  Species-specific Buffers for PG&E Activities

 

Table 1 lists the standard buffers and non-standard buffer ranges for activities with low- medium and medium-high disturbances. Nest buffers will be implemented and adjusted by the biologist1.

 

 

The following site-specific conditions are considered in determining if a reduced or increased buffer is appropriate:

l  Disturbance. Evaluate nest disturbance, including consideration of activity intensity and duration, construction type, amount of habitat disturbance, level of human disturbance or acclimation, activity length, and the amount of noise generated by the activity.

l  Existing Conditions. Assess site conditions to determine if there is acclimation to human disturbance.

l  Nest Concealment. Evaluate surrounding habitat for its ability to provide visual and/or acoustic barriers between the nest and construction.

l  Species Natural History. Consider individual species’ natural history, nest stage (incubation, rearing, fledging), and known tolerances to disturbance.

l  Habituation. Consider species habituation to new or ongoing activities.

l  Environmental Conditions. Consider weather and other related factors.

l  Helicopter Use. Consider helicopter type, flight plans, and duration.

 

 

Nest Buffer Implementation Guidelines

 

Step/Task/Responsible

Outcome and Components

1. Desktop review

Biologist

l  Assess habitat types and potential nesting bird species

l  Identify potentially appropriate buffers for the species that may nest

2. Preconstruction nesting bird surveys

Biologist

  • Conduct preconstruction surveys within the standard buffers
  • Document species detections including nests and active nests

3. Assign Buffers

Biologist

l  Assess intensity/duration of activity

l  Assess acclimation to human disturbance

l  Assess site-specific conditions

l  Consider species’ natural history, reproductive stage, tolerances to disturbance, and observed behavior

l  Evaluate and assign standard, reduced, or increased buffers

4. Implement Buffers

Biologist/Biological Monitor

  • Implement buffers when work activities are occurring
  • Conduct periodic biological monitoring where needed
  • Adjust buffers as appropriate

 

 

 

 

1 Biologist refers to an individual with a bachelor’s degree or above in a field related to biological sciences and demonstrated field expertise in ornithology, in particular, nesting behavior; these qualified biologists may be PG&E employees or contractors.

 

Pacific Gas and Electric Company                                                                                                  Species-specific Buffers for PG&E Activities

 

 

Species-Specific Buffers for


PG&E Activities

 

Buffer Assignment Process – Quick Reference

 
   

 

Yes                                                                                             No

 

 

Determine overall activity disturbance category for the planned work

 

Yes

 

 

Apply standard buffer(s) around active nests (Table 1)

 

No

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Are reduced or increased (e.g., helicopter use) buffers warranted?

Consider Site-specific Conditions:

  • Disturbance
  • Existing Conditions
  • Nest Concealment
  • Species Natural History
  • Habituation
  • Environmental Conditions
  • Helicopter Use
 

Conduct biological monitoring of nest(s) during work as needed

 

Yes                                                                         No

 

       
       

 

 

 

 
   

 

Pacific Gas and Electric Company                                                                                                  Species-specific Buffers for PG&E Activities

 

 

 

Other Biological Considerations in Determining Buffers

  • Provisioning frequency of hatchlings or older young
  • Egg turning
  • Egg incubation (female or male or combination)
  • Egg hardiness
    • Ambient Temperatures
    • Heat tolerance (eggs or nestlings)
    • Cold tolerance (eggs or nestlings)
    • Unsheltered nest risk
    • Premature fledging risk
    • Unattended nests and predation risk

 

 

 

 
   

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

Table 1. Species-specific Nest Buffers for PG&E Work Activities

 

*Atypically high-intensity activities, such as helicopter use usually require increased buffers beyond the standard buffer

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Mallard

Anas platyrhynchos

Scrapes under overhanging cover or in dense vegetation in uplands near water.

Ground

March through June; single brood.

Clutch incubated for 26–29 days by female; young are precocial.

100

30–100

15–30

Cinnamon Teal

Anas cyanoptera

Scrapes under overhanging cover or in dense vegetation in uplands near water.

Ground

April through August; single brood.

Clutch incubated for 24–25 days by female; young are precocial.

100

30–100

15–30

Canada Goose

Branta canadensis

Scrapes on slightly elevated, firm ground in uplands near water.

Ground

February through June; single brood.

Clutch incubated for 27–28 days by female; young are precocial.

100

30–100

15–30

Wood Duck

Aix sponsa

Cavities in riparian woodlands and other woodland habitats near water.

Up to 60 feet

April through August; single or double brood.

Clutch incubated for 27–35 days by female; young are precocial.

100

30–100

15–30

Blue-winged Teal

Anas discors

Scrapes in dense grass or forbs in wetlands or grasslands near water.

Ground

June through July; single brood

Clutch incubated for 23–24 days by female; young are precocial.

100

30–100

15–30

Northern Shoveler

Anas clypeata

Scrapes in low grasses or forbs in uplands near water.

Ground

March through July; single brood.

Clutch incubated for 25–27 days by female; young are precocial.

100

30–100

15–30

Gadwall

Anas strepera

Scrapes in dense, low emergent vegetation or grasses in uplands near water.

Ground

April through July; single brood.

Clutch incubated for 22–29 days by female; young are precocial.

100

30–100

15–30

American Wigeon

Anas americana

Scrapes in dense vegetation cover in uplands near water.

Ground

May through July; single brood.

Clutch incubated for 24–25 days by female; young are precocial.

100

30–100

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Redhead

Aythya americana

Platform nests over water in dense vegetation; occasionally nests in uplands near water.

Ground

April through June; single brood.

Clutch incubated for 24–26 days by both sexes; young are precocial.

100

30–100

15–30

Ring-necked Duck

Aythya collaris

Platform nests over water in dense emergent vegetation in wetlands.

Ground

May through August; single brood.

Clutch incubated for approximately 26 days by female; young are precocial.

100

30–100

15–30

Common Merganser

Mergus merganser

Cavities in trees, snags and stumps in riparian woodlands.

Up to 200 feet

March through September; single brood.

Clutch incubated for 28–32 days by female; young are precocial.

100

30–100

15–30

Ruddy Duck

Oxyura jamaicensis

Platform nests constructed on shallow water in dense, tall emergent vegetation.

Ground

April through October; single or double brood.

Clutch incubated for approximately 23 days by female; young are precocial.

100

30–100

15–30

Pied-billed Grebe

Podilymbus podiceps

Platform nests constructed in emergent vegetation bordering open water.

Ground

March through July; double brood.

Clutch incubated for approximately 23 days by both sexes; young are precocial.

100

30–100

15–30

Eared Grebe

Podiceps nigricollis

Platform nests in water on emergent wetland vegetation.

Ground

April through July; single brood.

Clutch incubated for approximately 21 days by both sexes by both sexes; young are precocial.

100

30–100

15–30

Western Grebe

Aechmophorus occidentalis

Platform nests in emergent vegetation or open water or, less frequently, on dry land near water.

Ground

May through August; single brood.

Clutch incubated for approximately 23 days by both sexes; young are precocial.

100

30–100

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Clark’s Grebe

Aechmophorus clarkii

Platform nests constructed in emergent vegetation or open water or, less frequently, on dry land near water.

Ground

May through August; single brood.

Clutch incubated for approximately 23 days by both sexes; young are precocial.

100

30–100

15–30

Double- crested Cormorant

Phalacrocorax auritus

Platform nests on islands, on the ground or in trees; also in power poles and other artificial structures.

Colonial nester.

Ground

March through August; single brood.

Clutch incubated for 25–29 days by both sexes; altricial young fledge at 37–44 days.

400

75–400

50–75

Pelagic Cormorant

Phalacrocorax pelagicus

Platform nests on steep cliffs along rocky and exposed shorelines along outer coasts, bays, inlets, estuaries, rapids, coves, surge narrows, harbors, lagoons, and coastal

log-storage sites. Colonial nester.

Ground

April through August; single or double brood

Clutch incubated for 28–32 days by both sexes; altricial young fledge at approximately 47 days

400

75–400

50–75

American Bittern

Botaurus lentiginosus

Platform nests in shallow water or on ground near water.

Ground

April through July; single brood.

Clutch incubated for approximately 24 days by female; altricial young fledge at approximately 14 days.

100

50–100

25–50

Least Bittern

Ixobrychus exilis

Platform nests about a foot above the water in freshwater marshes.

Ground

March through July; double brood.

Clutch incubated for 16–19 days by both sexes; altricial young fledge at

13–15 days.

100

50–100

25–50

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Great Blue Heron

Ardea herodias

Platform nests in tall trees or other types of vegetation near water. Colonial nester.

Up to 130 feet

January through July; single brood.

Clutch incubated for 25–29 days by both sexes; altricial young fledge at approximately 60 days.

400

75–400

50–75

Great Egret

Ardea alba

Platform nests in tall trees or other types of vegetation near water. Colonial nester.

10–80 feet

March through July; single brood.

Clutch incubated for approximately 26 days; semi-altricial young fledge at approximately 35–42 days.

400

75–400

50–75

Snowy Egret

Egretta thula

Platform nests in tall trees or other types of vegetation near water. Colonial nester.

Up to 30 feet but usually 10–15 feet

March through July; single brood.

Clutch incubated for 20–24 days by both sexes; semi-altricial young fledge at 21–28 days.

400

75–400

50–75

Cattle Egret

Bubulcus ibis

Platform nests in tall shrubs and trees near water.

Up to 30 feet but usually 5–

15 feet

April to July; single brood.

Clutch incubated for 23–25 days; semi- altricial young fledge at about 40 days.

400

75–400

50–75

Green Heron

Butorides striatus

Platform nests in shrubs, trees, thickets, or other vegetation near water.

10–30 feet, sometimes higher

March through July; single or double brood.

Clutch incubated for 19–21 days by both sexes; semi-altricial young fledge at 21–23 days.

100

50–100

25–50

Black- crowned Night-Heron

Nycticorax

Platform nests in shrubs, trees, thickets, or other vegetation near water. Colonial nester.

Up to 150 feet

January through June; double brood.

Clutch incubated for approximately 24 days by female; semi- altricial young fledge at 42–49 days.

400

75–400

50–75

White-faced Ibis

Plegadis chihi

Platform nests of emergent wetland vegetation in extensive wetlands. Colonial nester.

Ground

May to July; single brood.

Clutch incubated for 20–26 days by both sexes; altricial young fledge at

10–12 days.

400

75–400

50–75

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Turkey Vulture

Cathartes aura

Caves, rock crevices, possibly abandoned buildings, or other dark, secluded sites.

Up to 20 feet

March through June; single brood.

Clutch incubated for 37–41 days by both sexes; semi-altricial young fledge at approximately 77 days.

300

100–300

50–100

California Condor

Gymnogyps californianus

Caves on high, remote cliff-faces or in hollow in large redwood snag.

Cliff

Year-round, with egg-laying usually occurring in January or February; single brood.

Clutch incubated for 42–50 days by both sexes; semi-altricial young fledge at 35–49 days.

3,960

CRa

CR

White-tailed Kite

Elanus caeruleus

Platform nests in tall trees near grasslands, oak savannah, or other open habitats.

12–60 feet

February through July; sometimes double brood.

Clutch incubated for 28–30 days by both sexes; semi-altricial young fledge at 34–40 days.

300

200–300

100–200

Osprey

Pandion haliaetus

Platform nests on treetops, rocky outcrops, or utility poles near water.

Up to 60 feet

Mid-March through August; single brood.

Clutch incubated for 32–33 days by both sexes; semi-altricial young fledge at 51–59 days.

300

100–300

50–100

Bald Eagle

Haliaeetus leucocephalus

Platform nests in large trees or rocky outcrops close to lakes and large rivers.

50–180 feet

January to August; single brood.

Clutch incubated for 35–46 days by both sexes; semi-altricial young fledge at 70–77 days.

2,640

CR

CR

Northern Harrier

Circus cyaneus

Platform nests on ground in grasslands and open marshland with vegetative cover.

Ground

March through August; single brood.

Clutch incubated for 29–39 days by both sexes; altricial young fledge at 37 days.

300

200–300

100–200

Sharp-shinned Hawk

Accipiter striatus

Platform nests in trees in riparian woodland or other forested habitat with thick cover.

10–60 feet

April through August; single brood.

Clutch incubated for 30–35 days by both sexes; semi-altricial young fledge at approximately 23 days.

300

100–300

50–100

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Cooper's Hawk

Accipiter cooperii

Platform nests in trees in riparian woodlands or other forested habitat.

20–60 feet

March through July; single brood.

Clutch incubated for 36 days by female while male provisions her; semi-altricial young fledge at 30–34 days.

300

100–300

50–100

Northern Goshawk

Accipiter gentilis

Platform nests in top of tall coniferous or deciduous trees in mature forest.

Up to 75 feet

April through August; single brood.

Clutch incubated for 36–41 days by female while male provisions her; semi-altricial young fledge at 45 days old

1,320

200–1,320

100–200

Red- shouldered Hawk

Buteo lineatus

Platform nests below canopy in a variety of tree species.

20–60 feet

March through June; single brood.

Clutch incubated for 23–25 days by both sexes; semi-altricial young fledge at 35–42 days.

300

100–300

50–100

Swainson's Hawk

Buteo swainsoni

Platform nests in isolated trees in grasslands and agricultural areas.

5–30 feet

April through late June; single brood.

Clutch incubated for approximately 28 days by both sexes; semi- altricial young fledge at 28–35 days.

1,320–2,640

CR

CR

Red-tailed Hawk

Buteo jamaicensis

Platform nests in tall trees and other structures in a variety of open habitats.

35–90 feet

February through September; single brood.

Clutch incubated for 28–32 days by both sexes; semi-altricial young fledge at approximately 42 days.

250

100–300

50–100

Ferruginous Hawk

Buteo regalis

Nest in substrates ranging from cliffs, trees, utility structures, and farm buildings to haystacks and relatively level ground.

Up to 70 feet

Early March through May; single brood

Clutch incubated for 32–33 days by both sexes; altricial and nidicolous young fledge at 38–50 days.

300

100–300

50–100

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Golden Eagle

Aquila chrysaetos

Platform nests on rock ledges of outcrops or cliffs, and occasionally trees, in proximity to grassland, farmland, oak savannah, and other foraging grounds.

10–100 feet or higher on cliffs

February through July; single brood.

Clutch incubated for 43–45 days by female and occasionally male; semi-altricial young fledge at 63–70 days.

2,640

CR

CR

American Kestrel

Falco sparverius

Cavities in trees or other structures near grasslands, agricultural areas, oak savannah, or other open areas.

7–80 feet

March through July; may double brood.

Clutch incubated for 29–30 days by female while male provisions her; semi-altricial young fledge at approximately 30 days.

200

50–200

25–50

Prairie Falcon

Falco mexicanus

Ledges under overhangs on rock outcrops or cliffs near grassland, farmland, oak savannah, or other foraging habitat.

30–40 feet

March to May; single brood.

Clutch incubated for 29–31 days by female while male provisions her; semi-altricial young fledge at 40 days.

300

100–300

50–100

American Peregrine Falcon

Falco peregrinus

Cliff ledges, tall buildings, high bridges, and other high locations near open habitats.

High on cliffs or tall structures

March through June; single brood.

Clutch incubated for 28–29 days by both sexes; semi-altricial young fledge at 35–42 days.

500

CR

CR

Mount Pinos Sooty Grouse

Dendragapus fuliginosus

Scrapes near logs, shrubs, or other cover in coniferous forests, shrub-steppe habitat, and subalpine forests.

Ground

April through August; single brood.

Clutch incubated for 26–28 days by female; young are precocial.

100

50–100

25–50

Ruffed Grouse

Bonasa umbellus

Scrapes near the base of stumps, trees, or logs in forested habitat.

Ground

February through August; single brood.

Clutch incubated for approximately 24 days by female; young are precocial.

100

50–100

25–50

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Wild Turkey

Meleagris gallopavo

Scrapes in thick, low vegetation in oak woodlands and forest edges and clearings.

Ground

March through August; single brood.

Clutch incubated for approximately 28 days by female; young are precocial.

100

30–100

15–30

Gambel’s Quail

Callipepla gambellii

Scrapes under shrubs in desert habitats.

Ground

April through June; single or (rarely) double brood

Clutch incubated for 21–23 days by female while male guards; young are precocial.

100

50–100

25–50

California Quail

Callipepla californica

Scrapes under shrubs in riparian woodland, coastal scrub, chaparral, shrub- steppe, and mixed- hardwood forest.

Ground

March through July; single or double brood.

Clutch incubated for 21–23 days by female; young are precocial.

100

50–100

25–50

Mountain Quail

Oreortyx pictus

Scrapes under shrubs in mountain woodland and scrub habitats, usually near water.

Ground

April through June; single brood.

Clutch incubated for 24–25 days by female; young are precocial.

100

50–100

25–50

California Black Rail

Laterallus jamaicensis coturniculus

Cup nests on or near ground at upper edges of tidal marshes.

0–1 foot

March through July; single brood.

Clutch incubated for 17–20 days by both sexes; young are semi- precocial.

300–600

CR

CR

Clapper Rail (California, Yuma, Light- footed)

Rallus longirostris obscurus/yuman ensis/levipes

Platform nests in dense tidal marsh vegetation dominated by cordgrass or gumplant.

0–1 foot

February through August; single or double brood.

Clutch incubated for 23–29 days by both sexes; young are semi- precocial.

700

CR

CR

Virginia Rail

Rallus limicola

Platform nests in dense emergent vegetation in freshwater or estuarine marshes.

0–1 foot

April through June; single or double brood.

Clutch incubated for 14–16 days by both sexes; young are precocial.

100

50–100

25–50

Sora

Porzana carolina

Cup nests secured to reeds and rushes in freshwater or estuarine marshes.

0–1 foot

April through August; single brood.

Clutch incubated for approximately 14 days by both sexes; young are precocial.

100

50–100

25–50

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Common Gallinule

Gallinula galeata

Platform nests in dense vegetation at edge of marshes and other freshwater habitats.

Ground or water level

April through June; single or double brood.

Clutch incubated for 19–22 days by both sexes; young are precocial.

100

50–100

25–50

American Coot

Fulica americana

Platform nests in dense vegetation at edge of marshes and other freshwater habitats.

Ground or water level

March through July; single or double brood.

Clutch incubated for 21–24 days by both sexes; young are precocial.

100

30–100

15–30

Greater Sandhill Crane

Grus canadensis tabida

Platform nests in wetland vegetation on dry ground or shallow water in extensive marsh systems or grasslands.

Ground

April through August; single brood.

Clutch incubated for approximately 30 days by both sexes; young are precocial.

500

CR

CR

Western Snowy Plover

Charadrius alexandrinus nivosus

Scrapes on sand beaches/bars, salt pannes, or dry river beds.

Ground

April through August; double or triple brood.

Clutch incubated for approximately 24 days by both sexes; young are precocial.

600

(coastal)

 

300

(interior)

CR (coastal)

 

200–300

(interior)

CR (coastal)

 

100–200

(interior)

Killdeer

Charadrius vociferus

Scrapes in open places usually in areas with short grass, sand, or gravel.

Ground

March through June; sometimes double brood.

Clutch incubated for 24–26 days by both sexes; young are precocial.

75

30–75

15–30

Black-necked Stilt

Himantopus mexicanus

Scrapes or plant tufts/ tussocks in fresh, brackish, or salt marshes.

Ground

April through June; single brood.

Clutch incubated for 25–26 days by both sexes; young are precocial.

150

50–150

25–50

American Avocet

Recurvirostra americana

Scrapes on salt pannes, dikes, levees, and bare islands.

Ground

April through June; single brood.

Clutch incubated for 22–24 days by both sexes; young are precocial.

150

50–150

25–50

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Spotted Sandpiper

Actitis macularia

Scrapes in grasses among rocks, wrack, or driftwood.

Ground

April through August; single brood.

Clutch incubated for approximately 21 days by male; young are precocial.

75

30–75

15–30

Wilson’s Snipe

Gallinago gallinago

Scrapes in dense, medium to tall marshy or wet meadow vegetation.

Ground

April to August; single brood.

Clutch incubated for 17–20 days by female; young are precocial.

75

30–75

15–30

Lesser Yellowlegs

Tringa flavipes

Scrapes on shallow wetlands, trees or shrubs, and open areas.

Ground

Late April to mid- May; single brood.

Clutch incubated for 22–23 days by both sexes; young are precocial.

75

30–75

15–30

Whimbrel

Numenius phaeopus

Hummocks or mounds near dwarfed shrub, flat heath tundra, in grass or sedge tussocks, and on gravel.

Ground

Early June to early July; single brood.

Clutch incubated 22– 28 days by both sexes; young are precocial.

75

30–75

15–30

Black Skimmer

Rynchops niger

Saucer-shaped depressions on beaches, bars, dredge deposition, salt marsh.

Ground

May through August; single brood.

Clutch incubated 21– 23 days by both sexes; young are semi- precocial.

300

100–300

50–100

Long-billed Curlew

Numenius americanus

Scrapes in short-grass or mixed-prairie habitat with flat to rolling topography.

Ground

Mid-late March to early July; single brood.

Clutch incubated for 27–29 days by both sexes; young are precocial.

75

30–75

15-30

Marbled Godwit

Limosa fedoa

Scrapes in short, sparsely to moderately vegetated landscapes that include native grassland and wetland complexes with a variety of wetland classes (ephemeral to semipermanent).

Ground

Mid-May to late June; single brood.

Clutch incubated for 23–26 days by both sexes; young are precocial

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

California Gull

Larus californicus

Scrapes on islands in alkali or freshwater lakes and ponds or salt ponds.

Ground

April through August; single brood.

Clutch incubated for 23–27 days by both sexes; young are precocial.

150

50–150

25–50

Western Gull

Larus occidentalis

Ledges on cliffs, bluffs, bridges, buildings, and other areas inaccessible to nest predators.

Ground/cliff

April through August; single brood.

Clutch incubated for 30–32 days by both sexes; young are semi- precocial.

150

50–150

25–50

Caspian Tern

Sterna caspia

Scrapes on islands, beaches, and levees.

Ground

April through August; single brood.

Clutch incubated for approximately 20 days by both sexes; semi- precocial young fledge at approximately 14 days.

300

100–300

50–100

Forster’s Tern

Sterna forsteri

Scrapes on open levees, islands, and occasionally reed beds.

Ground

April through September; single brood.

Clutch incubated for approximately 23 days by both sexes; semi- altricial young fledge after approximately 7 days.

300

100–300

50–100

California Least Tern

Sterna antillarum

Scrapes on bare sandy or gravelly substrates in undisturbed areas.

Ground

May through June; single brood.

Clutch incubated for 20–25 days by both sexes; young are semi- precocial.

600

CR

CR

Black Tern

Chlidonias niger

Platform nests constructed of dead plant stems in freshwater wetlands and flooded rice fields.

Ground

May through August; single brood.

Clutch incubated for 20–22 days by both sexes; semi-precocial young fledge at approximately 14 days.

300

100–300

50–100

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Marbled Murrelet

Brachyramphus marmoratus

Horizontal limbs of large, old-growth conifers.

20–250 feet

March through September; likely a single brood.

Clutch incubated for approximately 30 days by both sexes; semi- precocial young fledge at approximately 21 days.

1,320 (high disturbance

)b

CR

CR

Cassin’s Auklet

Ptychoramphus aleuticus

Excavates burrows in soft soil, sod or natural cavities such as rock crevices and under trees, cacti or logs.

Colonial nester.

Ground/cliff

Varies within November through May; single and double brood.

Clutch incubated 37– 42 days by both sexes; altricial young confined to nest for 30 days.

400

75–400

50–75

Band-tailed Pigeon

Columba fasciata

Platform nests in trees or shrubs in oak woodlands, mixed hardwood forests, and mixed coniferous forests, usually in areas with oak trees.

5–180 feet

March through November; double or triple brood.

Clutch incubated for 18–20 days by both sexes; altricial young fledge at 25–30 days.

75

50–75

25–50

Mourning Dove

Zenaida macroura

Platform nests in a tree or shrub, but also on buildings or on ground, in a variety of habitats.

0–25 feet

February through September; several broods.

Clutch incubated for 14–15 days by both sexes; altricial young fledge at 13–15 days.

50

20–50

10–20

Western Yellow-billed Cuckoo

Coccyzus americanus

Platform nests in bushes or trees in dense, wide riparian woodlands.

2–20 feet

June through July; single brood.

Clutch incubated for 9– 11 days by both sexes; altricial young fledge at 21 days.

500

CR

CR

Greater Roadrunner

Geococcyx californianus

Cup nests in dense, brushy habitats in desert, sagebrush, and chaparral habitats.

3–15 feet

April through June; double brood.

Clutch incubated for 16–20 days by male; altricial young fledge at 18–30 days.

100

50–100

25–50

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Barn Owl

Tyto alba

Cavities in trees, buildings, crevices in rocks, outcrops, cliffs and quarries.

1–400 feet

January through May; often double broods.

Clutch incubated for 32–34 days by female while male provisions her; altricial young fledge at 60 days.

150

100–150

50–100

Flammulated Owl

Otus flammeolus

Cavities in trees, including aspens, oaks, pines, or other trees in forested areas.

10–40 feet

May through October; single brood.

Clutch incubated for 21–24 days by female while male provisions her; altricial young fledge at 20–26 days

200

100–200

50–100

Western Screech Owl

Otus kennicottii

Cavities in trees, particularly cottonwoods, in open woodlands.

10–30 feet

March through June; single brood.

Clutch incubated for 21–30 days by female while male provisions her; altricial young fledge at approximately 28 days.

200

100–200

50–100

Great Gray Owl

Strix nebulosa

Near high elevation meadows, on broken top trees or stick nests of other species.

30-50 feet

Late March through early July; single brood

Average clutch incubated for 29.7 days by female, with male provisioning her; semi- precocial young fledge at 21-28 days but can be dependent on nest site and male parent until fall.

1,320

CR

CR

Great Horned Owl

Bubo virginianus

Cavities or large nest platforms of other species in trees, rock ledges, or caves.

Uses existing platforms at various heights

January through May; single brood.

Clutch incubated for 26–35 days by female while male provisions her; altricial young fledge at 28–35 days.

300

100–300

50–100

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Northern Pygmy Owl

Glaucidium gnoma

Cavities in trees in oak woodlands and coniferous forests.

8–20 feet

April through August; number of broods unknown.

Clutch incubated for 25–30 days by female while male provisions her; semi-altricial young fledge at approximately 23 days.

200

50–200

25–50

Spotted Owl (Northern/Cal ifornia)

Strix occidentalis caurina/occident alis

Cavities or platforms (natural or old nests of other species) in coniferous or mixed hardwood forests.

30–165 feet

March through August; single brood.

Clutch incubated for 29–30 days by female while male provisions her; altricial young fledge at 34–36 days.

1,320 (high disturbance

)b

CR

CR

Burrowing Owl

Athene cunicularia

Small mammal burrows in open grasslands or at the edge of agricultural areas.

Ground

February through August; single brood.

Clutch incubated for 27–30 days by female while male provisions her; altricial young fledge at 40–45 days.

250

CR

CR

Long-eared Owl

Asio otus

Platform nests built by other species high in trees in coniferous forests or mixed woodlands.

10–30 feet

February through May; single brood.

Clutch incubated for 25–30 days by female while male provisions her; altricial young fledge at 23–24 days.

300

100–300

50–100

Short-eared Owl

Asio flammeus

Scrapes in tall, dense vegetation in grasslands and freshwater or brackish marshes.

Ground

March through July; single or possibly double brood.

Clutch incubated for 21–28 days by female while male provisions her; semi-altricial young leave nest at 31– 36 days.

300

100–300

50–100

Northern Saw- whet Owl

Aegolius acadicus

Cavities in trees in forested areas.

5–50 feet

March through August; single or double brood.

Clutch incubated for 21–28 days by female; semi-altricial young fledge at approximately 30 days.

200

100–200

50–100

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Lesser Nighthawk

Chordeiles acutipennis

Scrapes on bare gravelly or sandy ground in desert and sparsely vegetated habitats.

Ground

April through July; single or double brood.

Clutch incubated for 18–19 days by female; semi-precocial young fledge after 3 weeks.

75

30–75

20–30

Common Nighthawk

Chordeiles minor

Scrapes on bare gravelly or sandy ground in open areas within chaparral, grasslands, and forest openings.

Ground

June through July; double brood.

Clutch incubated for 18–20 days by female; semi-precocial young fledge after about 21 days.

75

30–75

20–30

Common Poorwill

Phalaenoptilus nuttallii

Scrapes on bare gravelly, sandy, or leaf- litter-covered ground in grasslands and desert habitats.

Ground

March through August; double brood.

Clutch incubated for 20–21 days by both sexes; young are precocial.

75

30–75

20–30

Black Swift

Cypseloides niger

Sheltered crevices or ledges on cliff faces on coast or under waterfall.

20–45 feet

May through September; single brood.

Clutch incubated for 21–27 days by both sexes; altricial young fledge at 45–49 days.

75

30–75

15–30

Vaux’s Swift

Chaetura vauxi

Cavities in redwoods, other conifers, and occasionally sycamores, chimneys, and buildings.

Up to 50 feet

May through August; single brood.

Clutch incubated for 18–20 days; altricial young fledge at approximately 28 days.

75

30–75

15–30

White- throated Swift

Aeronautes saxatalis

Rock cracks and crevices on cliffs and tall bridges.

10–195 feet

May through July; single brood.

Clutch incubated for 20–27 days; altricial young fledge at 40–46 days.

75

30–75

15–30

Black-chinned Hummingbird

Arcgilochus alexandri

Cup nests in trees and shrubs in woodlands, urban areas, and other habitats with nectar sources.

4–10 feet

April through June; two or three broods.

Clutch incubated for 13–16 days by female; altricial young fledge at approximately 21 days.

50

20–50

15–20

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Anna's Hummingbird

Calypte anna

Cup nests in trees and shrubs in woodlands, urban areas, and other habitats with nectar sources.

1–30 feet

December through June; two or three broods.

Clutch incubated for 16–17 days by female; altricial young fledge at 25–26 days.

50

20–50

15–20

Costa's Hummingbird

Calypte costae

Cup nests in trees and shrubs in riparian scrub, urban areas, and other habitats with nectar sources.

4–5 feet

April through July; single or occasionally double brood.

Clutch incubated for 15–18 days by female; altricial young fledge at 20–23 days.

50

20–50

15–20

Calliope Hummingbird

Stellula calliope

Cup nests in montane or riparian woodlands.

2–70 feet

May through August; single brood.

Clutch incubated for 15–16 days by female; altricial young fledge at 21–23 days.

50

20–50

15–20

Allen’s Hummingbird

Selasphorus sasin

Cup nests in shrubs, trees, or vines in a variety of forest and woodland types, as well as coastal scrub.

1–10 feet; occasionally as high as 90 feet

February through August; double brood.

Clutch incubated for 16–22 days by female; altricial young fledge at approximately 22 days.

50

20–50

15–20

Belted Kingfisher

Ceryle alcyon

Burrow in banks near fresh water.

Ground

April through July; single brood.

Clutch incubated for 23–24 days by both sexes; altricial young fledge at 30–35 days.

100

50–100

25–50

Lewis’s Woodpecker

Melanerpes lewis

Cavities in snags or dead branches in oak woodlands and mixed hardwood forests.

5–80 feet

May through July; single brood.

Clutch incubated for 13–14 days by both sexes; altricial young fledge at 28–34 days.

50

15–50

10–15

Acorn Woodpecker

Melanerpes formicivorous

Cavities in trees or snags in open woodlands, partly wooded areas, or utility poles near a source of acorns.

5–25 feet

April through July; two or three broods.

Clutch incubated for approximately 11 days by both sexes; altricial young fledge at approximately 31 days.

50

15–50

10–15

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Red-breasted Sapsucker

Sphyrapicus ruber

Cavities in trees or snags in coniferous or mixed forest.

5–45 feet

May through June; single brood.

Clutch incubated for 12–14 days by both sexes; altricial young fledge at 23–28 days.

50

15–50

10–15

Williamson’s Sapsucker

Sphyrapicus thyroideus

Tree cavities in conifer and mixed conifer- deciduous forests.

8–52 feet

Late April through late July; single brood.

Clutch incubated 12– 14 days by both sexes; altricial young fledge at 31–32 days.

50

15–50

10–15

Ladder- backed Woodpecker

Picoides scalaris

Cavities in trees and cactus.

4-20 feet

Unknown in CA; single brood.

Clutch incubated 14 days by both sexes; altricial young with unknown fledging period.

50

15–50

10–15

Nuttall's Woodpecker

Picoides nuttallii

Cavities in trees or snags in oak woodlands, or less frequently riparian or other woodlands.

2–60 feet

April through June; single brood.

Clutch incubated for approximately 14 days by both sexes; altricial young fledge at approximately 29 days.

50

15–50

10–15

Downy Woodpecker

Picoides pubescens

Cavities in trees or snags in riparian or other deciduous woodlands, or less frequently in coniferous forests.

3–44 feet

April through May; double brood.

Clutch incubated for approximately 12 days by both sexes; altricial young fledge at 20–22 days.

50

15–50

10–15

Hairy Woodpecker

Picoides villosus

Cavities in snags or dead branches in woodlands and coniferous forests.

3–102 feet

March through August; single brood.

Clutch incubated for 11–15 days by both sexes; altricial young fledge at 28–30 days.

50

15–50

10–15

White-headed Woodpecker

Picoides albolarvatus

Cavities in snags or stumps at least 2 feet in diameter in pine forests.

6–50 feet

April through August; single brood.

Both sexes incubate clutch for 13–15 days; altricial young fledge at approximately 26 days.

50

15–50

10–15

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Northern Flicker

Colaptes auratus

Cavities in tree trunks or snags in open or sparsely wooded areas; more often in live wood.

8–45 feet

April through June; single brood.

Clutch incubated for 11–13 days by both sexes; altricial young fledge at 25–28 days.

50

15–50

10–15

Pileated Woodpecker

Dryocopus pileatus

Cavities in snags or dead branches in mature forests.

15–70 feet

March to July; single brood

Clutch incubated for approximately 18 days by both sexes; altricial young fledge at 26–28 days.

50

15–50

10–15

Olive-sided Flycatcher

Contopus cooperi

Cup nest in trees in open conifer forest or mixed woodland.

5–70 feet

June through July; single brood.

Clutch incubated for 16–17 days by female; altricial young fledge at 15–19 days.

75

30–75

15–30

Western Wood-Pewee

Contopus sordidulus

Cup nests in trees, mainly coniferous but sometimes deciduous woodlands near watercourses.

15–30 feet

May through July; single brood.

Clutch incubated for approximately 12 days by female; altricial young fledge at 14–18 days.

75

30–75

15–30

Willow Flycatcher (Southwester n, Little, adastus)

Empidonax traillii extimus/brewste ri/adastus

Cup nests in densely vegetated riparian associations of cottonwoods and willows.

5–20 feet

May through July; single brood.

Clutch incubated for 12–13 days by female; altricial young fledge at 14 days.

300

CR

CR

Vermilion Flycatcher

Pyrocephalus rubinus

Loosely constructed nest in wooded riparian areas.

8-55 feet

Mid-March through mid-July; single or double brood.

Clutch incubated for 14-15 days by female;

altricial young fledge at 14-16 days.

75

30–75

15–30

Hammond’s Flycatcher

Empidonax hammondii

Cup nests in trees in forests and woodlands.

6–65 feet

May through July; single brood.

Clutch incubated for 12–15 days by female; altricial young fledge at 17–18 days .

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Dusky Flycatcher

Empidonax oberholseri

Cup nests in small trees or shrubs pine forests

3–20 feet

May through July; single brood.

Clutch incubated for 12–15 days by female; altricial young fledge at approximately 18 days.

75

30–75

15–30

Western (Pacific-slope and Cordilleran) Flycatcher

Empidonax difficilis/occident alis

Cup nests in cavities or tree stumps or on ledges or crevices in woodlands and forests often in riparian areas.

0–30 feet

April through July; sometimes double brood.

Clutch incubated for 14–15 days by female; altricial young fledge at 15–18 days.

75

30–75

15–30

Black Phoebe

Sayornis nigricans

Cup nests of mud cemented to vertical structures, often under an overhang.

3–10 feet

March through June; double brood.

Clutch incubated for 15–18 days by female; altricial young fledge at approximately 21 days.

75

30–75

15–30

Say's Phoebe

Sayornis saya

Cup nests on ledges with overhang or under a bridge; nest not made of mud like black phoebe.

0–79 feet

March through June; double brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 14–18 days.

75

30–75

15–30

Ash-throated Flycatcher

Myiarchus cinerascens

Cavities in trees and other structures in open deciduous woodland.

2–70 feet

May through July; single brood.

Clutch incubated for approximately 15 days by female; altricial young fledge at 16–17 days.

50

15–50

10–15

Cassin's Kingbird

Tyrannus vociferans

Cup nests in trees in savannahs and other open habitats.

25–74 feet

April through June; double brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 14 days.

75

30–75

15–30

Western Kingbird

Tyrannus verticalis

Cup nests in trees and artificial structures (e.g., power poles) in variety of open habitats.

13–55 feet

April through June; double brood.

Clutch incubated for 12–14 days by both sexes; altricial young fledge at 13–19 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Loggerhead Shrike

Lanius ludovicianus

Cup nests in dense shrubs near grasslands and other open habitats.

3–8 feet

February through June; two or three broods.

Clutch incubated for 14–16 days by female while male provisions her; altricial young fledge at 17–21 days.

75

30–75

15–30

Least Bell's Vireo

Vireo bellii pusillus

Cup nests in dense shrubs and small trees in dense riparian areas.

1–3 feet

April through August; double brood.

Clutch incubated for approximately 14 days by both sexes; altricial young fledge at 10–12 days.

500

CR

CR

Arizona Bell’s Vireo

Vireo bellii arizonae

Cup nests in dense shrubs and small trees in dense riparian areas.

1–3 feet

April through August; double brood.

Clutch incubated for approximately 14 days by both sexes; altricial young fledge at 10–12 days.

500

CR

CR

Cassin’s Vireo

Vireo cassinii

Cup nests in a trees or shrubs in oak or oak- coniferous or mixed riparian woodland.

5–35 feet

April through July; single brood.

Clutch incubated for approximately 15 days by both sexes; altricial young fledge at 13 days.

75

30–75

15–30

Hutton's Vireo

Vireo huttoni

Cup nests on a twig forks in oaks and other trees along streams and canyons.

3–45 feet

March thorugh June; single or double brood.

Clutch incubated for 14–16 days by both sexes; altricial young fledge at approximately 14 days.

75

30–75

15–30

Warbling Vireo

Vireo gilvus

Cut nests high in trees in mature oak woodlands and mixed deciduous forests.

20–60 feet

May through July; double brood.

Clutch incubated for 12–13 days by both sexes; altricial young fledge at approximately 14 days.

75

30–75

15–30

Gray Vireo

Vireo vicinior

Nests in thorn scrub or pinyon-juniper woodland, low in thorny or twiggy shrub or tree.

2–8 feet

Mid-April through mid-August

Clutch incubated 13-14 days by both sexes; altricial young fledge at 13-14 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Gray Jay

Perisoreus canadensis

Cup nests in shrubs or trees in coniferous forests and sometimes oak woodlands.

5–30 feet

March through July; single brood.

Clutch is incubated for 16–18 days; altricial young fledge at approximately 15 days.

75

30–75

15–30

Steller's Jay

Cyanocitta stelleri

Cup nests in trees or shrubs in coniferous or mixed hardwood forests or other woodlands.

7–16 feet

April through June; likely single brood.

Clutch incubated for approximately 16 days by female while male provisions her; altricial young fledge at 18 days.

75

30–75

15–30

Western Scrub-jay

Aphelocoma californica

Platform nests in shrubs, trees, bushes or vine tangles in a wide variety of habitats, including oak woodlands, savannah, agricultural, and suburban.

2–50 feet

March through June; single brood.

Clutch incubated for 15–17 days by female while male provisions her; altricial young fledge at 18 days.

75

30–75

15–30

Pinyon Jay

Gymnorhinus cyanocephalus

Cup nests in trees in ponderosa-pine forest.

3–115 feet

Mid-March through late June; single brood.

Clutch incubated 17 days by female, male provisions female; altricial young fledge at 21–22 days.

75

30–75

15–30

Clark’s Nutcracker

Nucifraga columbiana

Cup nests in pines, junipers, and firs in mountain coniferous forests.

8–45 feet

February through August; single brood.

Clutch incubated for 16–18 days by both sexes; altricial young fledge at approximately 22 days.

75

30–75

15–30

Yellow-billed Magpie

Pica nuttallii

Platform nests in oak trees and occasionally other trees in savannah.

30–80 feet

February through July; single brood.

Clutch incubated for 16–18 days by female while male provisions her; altricial young fledge at approximately 30 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

American Crow

Corvus brachyrhynchos

Platform nests in variety of large trees, usually near the trunk, and artificial structures in a wide variety of habitats.

10–70 feet

February through July; single brood.

Clutch incubated for approximately 18 days by female and possibly helpers; altricial young fledge at 35 days.

50

30–50

15–30

Common Raven

Corvus corax

Platform nests on sheltered rock ledges or in forks of large trees and artificial structures in a wide variety of habitats.

45–80 feet

February through July; single brood.

Clutch incubated for 20–21 days by female while male provisions her; altricial young fledge at 35–42 days.

50

30–50

15–30

Western Bluebird

Sialia mexicana

Cavities in woodland clearings, savannahs, and other open habitats.

4–48 feet

April through June; double brood.

Clutch incubated for 13–14 days by female; altricial young fledge at approximately 20 days.

50

15–50

10–15

Townsend’s Solitaire

Myadestes townsendi

Cup nests on ground usually on cutbanks and other slopes in mountain coniferous forests.

0–12 feet

April through June; single or double brood.

Clutch incubated for 11–14 days by female; altricial young fledge at 10–14 days.

75

30–75

15–30

Swainson’s Thrush

Catharus ustulatus

Cup nests in dense shrubs, often in riparian woodlands and mixed coniferous forests.

2–20 feet

April through August; single or (rarely) double brood.

Clutch incubated for 10–13 days by female; altricial young fledge after 10–12 days.

75

30–75

15–30

Hermit Thrush

Catharus guttatus

Cup nests in dense shrubs variety of forests and woodlands.

2–10 feet

June through July; single or double brood.

Clutch incubated for 12–13 days by female; altricial young fledge at 12–13 days.

75

30–75

15–30

American Robin

Turdus migratorius

Cup nests in trees or shrubs, ledges of buildings, or in a tree forks in variety of open habitats.

3–25 feet

May through July; two or three broods.

Clutch incubated for 11–14 days by female; altricial young fledge at 14–16 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Varied Thrush

Ixoreus maevius

Cup nests on horizontal branches of trees in moist coniferous forests.

5–20 feet

April through August; double brood.

Clutch incubated for approximately 14 days by female; altricial young fledge at 13–15 days.

75

30–75

15–30

Horned Lark

Eremophila alpestris

Scrapes in a small hollow usually sheltered by plant tufts in grasslands and other open habitats.

Ground

February through August; two or three broods.

Clutch incubated for 10–14 days by female; altricial young fledge at 9–12 days.

75

30–75

15–30

Purple Martin

Progne subis

Cavities in trees in mountain forests, particularly burned areas with snags.

10–34 feet

April through August; single brood

Clutch incubated for 15–18 days by the female; altricial young fledge at 24–31 days.

75

30–75

15–30

Tree Swallow

Tachycineta bicolor

Cavities in open habitats, such as grasslands or wetlands with dead standing trees; usually near water.

10–16 feet

April through August; double brood.

Clutch is incubated for 13–16 days; altricial young fledge at 16–20 days.

50

30–50

15–30

Violet-green Swallow

Tachycineta thalassina

Cavities or occasionally on cliffs or banks in deciduous, coniferous, and mixed woodlands.

9–17 feet

April through August; single brood.

Clutch is incubated for 13–15 days; altricial young fledge at 16–24 days.

50

30–50

15–30

Northern Rough-winged Swallow

Stelgidopteryx serripennis

Cavities on a steep slope or use crevices and holes in bridges and buildings.

Ground/cliff

April through June; single brood.

Clutch incubated for 15–16 days by female; altricial young fledge at 18–21 days.

75

30–75

15–30

Bank Swallow

Riparia riparia

Cavities in sandy banks or cliffs along rivers.

Ground/cliff

May through July; single brood.

Clutch incubated for 12–16 days by both sexes; altricial young fledge at 18–24 days.

100

CR

CR

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Barn Swallow

Hirundo rustica

Cup nests often on buildings and bridges in open habitats near water.

6–40 feet

April through July; double brood.

Clutch incubated for 14–16 days by both sexes; altricial young fledge at 17–24 days.

50

30–50

15–30

Cliff Swallow

Petrochelidon pyrrhonota

Closed mud nests often on cliff faces, buildings, or bridges in open habitats near water.

5 feet and higher

April through June; double brood.

Clutch incubated for 12–14 days by both sexes; altricial young fledge at approximately 23 days.

50

30–50

15–30

Mountain Chickadee

Poecile gambeli

Cavities in trees in coniferous mountain forests.

16–50 feet

April through August; single or double brood.

Clutch is incubated for 14 days; altricial young fledge at 20 days.

50

15–50

10–15

Chestnut- backed Chickadee

Poecile rufescens

Cavities trees in coniferous forests and deciduous woodlands.

0–80 feet

March through July; single or (rarely) double brood.

Clutch is incubated for 12–14 days by female; altricial young fledge at 18–21 days.

50

15–50

10–15

Oak Titmouse

Baeolophus inornatus

Cavities in trees in oak woodlands.

2–40 feet

March through June; single brood.

Clutch incubated for 14–16 days by female; altricial young fledge at 17 days.

50

15–50

10–15

Bushtit

Psaltriparus minimus

Pendulous nests in trees and shrubs in a variety of habitats.

3–98 feet

February through June; double brood.

Clutch incubated for 12–13 days by both sexes; altricial young fledge at 14–15 days.

50

30–50

15–30

Red-breasted Nuthatch

Sitta canadensis

Cavities in trees in coniferous forests and mixed woodlands.

5–40 feet

April through July; single or (rarely) double brood.

Clutch incubated for approximately 12 days by female while male provisions her; altricial young fledge at 18–21 days.

75

30–75

15–30

White- breasted Nuthatch

Sitta carolinensis

Cavities in trees in deciduous woodlands and mixed coniferous forests.

1–50 feet

March through June; single brood.

Clutch incubated for 12–14 days by female while male provisions her; altricial young fledge at 14–16 days.

50

15–50

10–15

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Pygmy Nuthatch

Sitta pygmaea

Cavities in dead trees or dead portions of trees in long-needled pine forests.

20–70 feet

May through July; single or double brood.

Clutch incubated for 15–16 days by female while male provisions her; altricial young fledge at 20–21 days.

75

30–75

15–30

Brown Creeper

Certhia americana

Cup nests concealed behind loose bark, in crevices on a trees in coniferous forests and mixed coniferous forests..

5–15 feet

May through July; single brood.

Clutch incubated for 15–18 days by female while male provisions her; altricial young fledge at 21 days.

75

30–75

15–30

Rock Wren

Salpinctes obsoletus

Cavities on rocky slopes

Ground/cliff

March through June; double or triple brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 14–16 days.

75

30–75

15–30

Canyon Wren

Catherpes mexicanus

Cup nests in rock crevices or ledges in rocy habitats.

Ground/cliff

March through July; double brood.

Clutch incubated for 12–18 days by female; altricial young fledge at approximately 15 days.

75

30–75

15–30

Bewick’s Wren

Thryomanes bewickii

Cavities in trees, brush, or between rocks in open woodlands and shrubby areas.

0–20 feet

March through July; double or triple brood.

Clutch incubated for approximately 14 days by female while male provisions her; altricial young fledge at approximately 14 days.

75

30–75

15–30

House Wren

Troglodytes aedon

Cavities in shrubby cover and thickets in open woodlands and hedgerows.

0–20 feet

April through July; double brood.

Clutch incubated for 13–15 days by female; altricial young fledge at 12–18 days.

50

30–50

15–30

Pacific Wren

Troglodytes pacificus

Cavities or crevices in logs, stumps, root balls, or trees in variety of forests.

0–10 feet

March through August; single or double brood.

Clutch is incubated for 14–17 days by female; altricial young fledge at approximately 19 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Marsh Wren

Cistothorus palustris

Domed nests over the water in tall rushes and marsh grasses in wetland habitats.

1–5 feet

March through July; double or triple brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 13–15 days.

75

30–75

15–30

American Dipper

Cinclus mexicanus

Domed nests in crevices in rocks, logs, bridges, or other protected areas immediately adjacent to water.

0–30 feet

March through August; single or double brood.

Clutch is incubated for approximately 16 days by female; altricial young fledge at 18–25 days.

75

30–75

15–30

Golden- crowned Kinglet

Regulus satrapa

Hanging nests woven onto conifer twigs in coniferous forests and mixed woodlands.

6–50 feet

May through August; single or double brood.

Clutch is incubated for 14–15 days by female; altricial young fledge at 16–19 days.

75

30–75

15–30

Ruby-crowned Kinglet

Regulus calendula

Cup nests in trees in coniferous woodlands.

4–100 feet

May through July; single brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 16 days.

75

30–75

15–30

Blue-gray Gnatcatcher

Polioptila caerulea

Cup nests in trees or shrubs in a variety of habitats from shrublands to mature forests.

3–80 feet

April through July; double brood.

Clutch incubated for approximately 15 days by both sexes; altricial young fledge at 12–13 days.

75

30–75

15–30

Coastal California Gnatcatcher

Polioptila californica californica

Cup nests in coastal sage scrub and chaparral.

2–3 feet

February through August; double brood.

Clutch incubated for approximately 14 days by both sexes; altricial young fledge at 15–16 days.

500

CR

CR

Wrentit

Chamaea fasciata

Cup nests in coastal sage scrub and chaparral.

1–4 feet

March through July; double brood.

Clutch incubated for 15–16 days by both sexes; altricial young fledge at 15–16 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Northern Mockingbird

Mimus polyglottos

Cup nests in shrubs and trees in variety of habitats, including woodlands and in developed areas.

3–10 feet

March through July; double or triple brood.

Clutch incubated for 11–14 days by female; altricial young fledge at 12–14 days.

75

30–75

15–30

Sage Thrasher

Oreoscoptes montanus

Cup nests in low shrubs in sagebrush habitat.

2–3 feet

April through August; single or double brood.

Clutch is incubated for 13–17 days; altricial young fledge at approximately 11 days.

75

30–75

15–30

Le Conte's Thrasher

Toxostoma lecontei

Cup nests in cholla or a low tree, in desert areas with shrubby growth.

2–8 feet

February through June; double or triple brood.

Clutch incubated for 14–20 days by both sexes; altricial young fledge at 14–17 days.

75

30–75

15–30

California Thrasher

Toxostoma redivivum

Cup nests in low trees or shrubs in sage scrub and chaparral.

2–4 feet

February through July; double brood.

Clutch incubated for approximately 14 days by both sexes; altricial young fledge at 12–14 days.

75

30–75

15–30

Bendire’s Thrasher

Toxostoma bendirei

Cup nests in shrubs, cacti, or trees.

2–5 feet

Late February through April; single, double, or triple brood.

Clutch incubated 12– 14 days by both parents; altricial young fledge at 12–13 days.

75

30–75

15–30

Cedar Waxwing

Bombycilla cedrorum

Cup nests in forks of trees in riparian or redwood forests.

5–50 feet

June through August; single or double brood.

Clutch is incubated for 12–14 days; altricial young fledge at 16–18 days

75

30–75

15–30

Phainopepla

Phainopepla nitens

Cup nests in trees in desert scrub and coastal chaparral.

6–11 feet

Late February— desert; April through June— coastal; double brood.

Clutch incubated for 14–15 days by both sexes; altricial young fledge at 18–19 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Orange- crowned Warbler

Oreothlypis celata

Cup nests on the ground or in crevices near ground in a variety of habitats, often where woodland and chaparral habitats meet.

Ground

April through July; single or double brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 12–13 days.

75

30–75

15–30

Nashville Warbler

Oreothlypis ruficapilla

Cup nests on ground concealed in bushes or small trees in woodland edges or shrubby areas.

Ground

May through July; single brood.

Clutch incubated for 11–12 days by female; altricial young fledge at 11 days.

75

30–75

15–30

Yellow Warbler

Setophaga petechia

Cup nests in trees or shrubs in shrubby growth in riparian areas.

2–12 feet

April through July; single brood.

Clutch incubated for 11–12 days by female; altricial young fledge at days.

75

30–75

15–30

Yellow- rumped Warbler

Setophaga coronata

Cup nests in trees in coniferous woodlands.

4–50 feet

April through July; single or (rarely) double brood.

Clutch incubated for 12–13 days by female; altricial young fledge at 12–14 days.

75

30–75

15–30

Black- throated Gray Warbler

Setophaga nigrescens

Cup nests in trees or shrubs in open woodlands in mountainous areas.

8–35 feet

May through July; single or double brood.

Clutch incubated by female; young are altricial. Length of incubation period and age at fledging undocumented.

75

30–75

15–30

Hermit Warbler

Setophaga occidentalis

Cup nests high in trees in coniferous forests

20–40 feet

May through July; single brood.

Clutch incubated for approximately 12 days by both sexes; altricial young fledge at 8–10 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

MacGillivray's Warbler

Geothlypis tolmiei

Cup nests in low thick shrub in riparian woodlands and coniferous or mixed forests.

1–5 feet

May through July; single brood.

Clutch incubated for 11–13 days by female; altricial young fledge at 8–10 days.

75

30–75

15–30

Common Yellowthroat

Geothlypis trichas

Cup nests in reeds and other wetland vegetation over water or near water.

1–3 feet

April through July; single brood.

Clutch incubated for approximately 12 days by female; altricial young fledge at 9–10 days.

75

30–75

15–30

Wilson's Warbler

Cardellina pusilla

Cup nests on ground, hidden by vegetation in shrub habitats in forests and chaparral.

Ground

April through June; single or (rarely) double brood.

Clutch incubated for 11–13 days by female; altricial young fledge at 10–11 days.

75

30–75

15–30

Yellow- breasted Chat

Icteria virens

Cup nests in a dense shrub or tangle in thick riparian vegetation.

1–8 feet

April through July; single or (rarely) brood.

Clutch incubated for 11–12 days by female; altricial young fledge at 8–11 days.

75

30–75

15–30

Western Tanager

Piranga ludoviciana

Cup nests high in trees on outer branches in coniferous and mixed hardwood forests.

8–75 feet

May through July; single brood.

Clutch incubated for approximately 13 days by female; altricial young fledge at 10–11 days.

75

30–75

15–30

Green-tailed Towhee

Pipilo chlorulus

Cup nests in or at base of low shrubs in chaparral and disturbed (low growth) forest habitats.

0–2 feet

April through August; single or double brood.

Clutch incubated for 11–13 days by female; altricial young fledge at 11–14 days.

75

30–75

15–30

Spotted Towhee

Pipilo maculatus

Cup nests usually on the ground or very low in bushes shrubby habitats.

2–12 feet

April through July; single or double brood.

Clutch incubated for 12–13 days by female; altricial young fledge at approximately 9 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

California Towhee

Melozone crissalis

Cup nests in shrubs or small trees in brushy habitats.

4–12 feet

March through July; double or triple brood.

Clutch incubated for approximately 14 days by female; altricial young fledge at approximately 10 days.

75

30–75

15–30

Rufous- crowned Sparrow

Aimophila ruficeps

Cup nests at the base of a grass clumps, in dry rocky areas with sparse undergrowth.

0–2 feet

April through June; single or double brood.

Clutch incubated for 11–13 days by female; altricial young fledge at 9 days.

75

30–75

15–30

Chipping Sparrow

Spizella passerina

Cup nests in trees or shrubs in open woodlands.

3–20 feet

April through July; double brood.

Clutch incubated for 11–14 days by female; altricial young fledge at 9–12 days.

75

30–75

15–30

Black-chinned Sparrow

Spizella atrogularis

Cup nests in shrubs in chaparral habitat.

1–3 feet

April through August; single brood.

Clutch incubated for 12–13 days by female; altricial young fledge at approximately 10 days.

75

30–75

15–30

Lark Sparrow

Chondestes grammacus

Cup nests usually in scrapes on ground in open grasslands, or cup nests in herbaceous or woody shrubs.

0–9 feet

April through July; double brood.

Clutch incubated for 11–13 days by female; altricial young fledge at 9–10 days.

75

30–75

15–30

Black- throated Sparrow

Amphispiza bilineata

Cup nests in thorny shrubs or cactus in chaparral or desert habitats.

1 foot

April through June; single or double brood.

Clutch incubated for 12–13 days by female; altricial young fledge at approximately 9.5 days.

75

30–75

15–30

Sage Sparrow

Artemisiospiza belli

Cup nests in thick bushes in chaparral and desert habitats.

1 foot

March through June; double brood.

Clutch incubated for 10–16 days by female; altricial young fledge at 9–10 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Bryant’s Savannah Sparrow

Passerculus sandwichensis alaudinus

Cup nests on ground in dense, moist grasslands, ruderal vegetation, or saltmarsh vegetation.

Ground

April through July; single or double brood.

Clutch incubated for 10–13 days; altricial young fledge at 7–14 days.

75

30–75

15–30

Belding’s Savannah Sparrow

Passerculus sandwichensis beldingi

Cup nests on ground in dense, moist grasslands, ruderal vegetation, or saltmarsh vegetation.

Ground

April through July; single or double brood.

Clutch incubated for 10–13 days; altricial young fledge at 7–14 days.

75

CR

CR

Grasshopper Sparrow

Ammodramus savannarum

Ground nest at the base of bunchgrass or other vegetation in grasslands.

Ground

April through July; double or triple brood.

Clutch incubated for 11–12 days by female; altricial young fledge after 9 days.

75

30–75

15–30

Song Sparrow

Melospiza melodia

Cup nests in low grass and shrubs or thickets in a variety of forest, shrub, grassland, marsh, and riparian habitats.

1–3 feet

March through July; double, triple, or quadruple brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 10 days.

75

30–75

15–30

Suisun Song Sparrow

Melospiza melodia maxillaris

Cup nests in low grass and shrubs or thickets in a variety of forest, shrub, grassland, marsh, and riparian habitats.

1–3 feet

March through July; double, triple, or quadruple brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 10 days.

75

30–75

15–30

Alameda Song Sparrow

Melospiza melodia pusillula

Cup nests in low grass and shrubs or thickets in a variety of forest, shrub, grassland, marsh, and riparian habitats.

1–3 feet

March through July; double, triple, or quadruple brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 10 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

San Pablo Song Sparrow

Melospiza melodia samuelis

Cup nests in low grass and shrubs or thickets in a variety of forest, shrub, grassland, marsh, and riparian habitats.

1–3 feet

March through July; double, triple, or quadruple brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 10 days.

75

30–75

15–30

Lincoln's Sparrow

Melospiza lincolnii

Cup nests in depressions on the ground in shrubby growth at forest edges, clearings; often near wet areas

Ground

May through July; double brood.

Clutch incubated for 13–14 days by female; altricial young fledge at 10–12 days.

75

30–75

15–30

White- crowned Sparrow

Zonotrichia leucophrys

Cup nests on ground or in shrubs or small trees in coastal or mountain chaparral and mountain forests.

0–5 feet

May through September; double or triple brood.

Clutch incubated for 9– 15 days; altricial young fledge at 9–11 days

50

30–50

15–30

Dark-eyed Junco

Junco hyemalis

Cup nests in depressions on the ground among tree roots or brush in variety of woodland habitats; also on building ledges or in trees.

Ground, but up to 8 feet on ledges or trees

April through July; double or triple brood.

Clutch incubated for 12–13 days by female; altricial young fledge at 10–13 days.

50

30–50

15–30

Black-headed Grosbeak

Pheucticus melanocephalus

Cup nests in trees or shrubs in thickets, under trees along streams in riparian woodlands or coniferous or mixed forests near edges.

6–12 feet

April through July; single brood.

Clutch incubated for 12–13 days by both sexes; altricial young fledge at 12 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Blue Grosbeak

Guiraca caerulea

Cup nests small trees, shrubs, or other low vegetation, usually near open areas in desert, chaparral, savannah, and forest edge habitats.

<1–16 feet

April through August; single or double brood.

Clutch incubated for 11–12 days by female; altricial young fledge at 9–13 days.

75

30–75

15–30

Lazuli Bunting

Passerina amoena

Cup nests in low thick shrubby riparian or chaparral habitat.

1–10 feet

May through July; double brood.

Clutch incubated for approximately 12 days by female; altricial young fledge at 10–15 days.

75

30–75

15–30

Red-winged Blackbird

Agelaius phoeniceus

Cup nests in cattails, bulrushes, and other marsh vegetation or in shrubs in grasslands and shrubby habitats.

1–13 feet

March through June; double brood.

Clutch incubated for 10–12 days by female; altricial young fledge at 10–11 days.

75

350 (Kern Red-winged Blackbird)

30–75

200–350 (Kern

Red-winged Blackbird)

15–30

100–200 (Kern

Red-winged Blackbird)

Tricolored Blackbird

Agelaius tricolor

Cup nests in cattails and bulrushes in marshes and shrubby areas in uplands and agricultural areas.

Colonial nester.

1–5 feet

April through June; double brood.

Clutch incubated for approximately 11 days by female; altricial young fledge at 13 days.

350

CR

CR

Yellow- headed Blackbird

Xanthocephalus xanthocephalus

Cup nests cattails or other emergent vegetation over water in marshes with thick vegetative growth.

Colonial nester.

2–3 feet

May through June; single brood.

Clutch incubated for 10–13 days by female; altricial young fledge at 9–12 days old

350

200–350

100–200

Brewer's Blackbird

Euphagus cyanocephalus

Cup nests high in trees or shrubs near water in agricultural or suburban/urban areas.

8–43 feet

March through July; single or double brood.

Clutch incubated for 12–13 days by female; altricial young fledge at approximately 13 days.

50

30–50

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Western Meadowlark

Sturnella neglecta

Domed nests on ground in open grasslands.

Ground

March through June; double brood.

Clutch incubated for 13–15 days by female; altricial young fledge at 10–12 days.

75

30–75

15–30

Hooded Oriole

Icterus cucullatus

Closed cup nests high in trees (often palm treets) or shrubs, often in riparian habitat and in suburban areas.

10–45 feet

April through August; double or triple brood.

Clutch incubated for 12–14 days by female; altricial young fledge at approximately 14 days.

75

30–75

15–30

Bullock’s Oriole

Icterus bullockii

Pensile cup nests in twig fork of trees in riparian and oak woodlands.

6–15 feet

April through July; single brood.

Clutch incubated for approximately 14 days by female; altricial young fledge at approximately 14 days.

75

30–75

15–30

Pine Grosbeak

Pinicola enucleator

Cup nests near the end of horizontal tree branches in coniferous forests.

16–35 feet

May through August; single brood.

Clutch incubated for 13–14 days by female; altricial young fledge at approximately 14 days.

75

30–75

15–30

Purple Finch

Haemorhous purpureus

Cup nests high in trees well hidden by foliage, in coniferous forests and woodlands.

5–60 feet

April through June; double brood.

Clutch incubated for approximately 13 days by female; altricial young fledge at approximately 14 days.

75

30–75

15–30

House Finch

Haemorhous mexicanus

Cup nests in trees, building ledges, and other locations in urban/suburban, agriculture, woodlands, desert, and chaparral habitats.

5–7 feet

March through July; double or triple brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 14–16 days.

50

15–30

10–15

Red Crossbill

Loxia curvirostra

Loose cup constructed near the end of horizontal branch in coniferous forests.

6–60 feet

February through June; single brood.

Clutch incubated for 12–16 days by female; altricial young fledge at 17–22 days.

75

30–75

15–30

 

Pacific Gas and Electric Company                                                                                                                                                                                                                             Species-specific Buffers for PG&E Activities

 

 

 

Common Name

 

 

Scientific Name

 

Nest Location, Substrate, and Habitat

 

 

Vertical Height

Peak Breeding Season/Number of Broods per Season

 

Incubation Duration/Chick- rearing Duration

 

Standard Buffer* (feet)

Medium to High Disturbance Category Buffer (feet)

Low to Medium Disturbance Category Buffer (feet)

Pine Siskin

Spinus pinus

Cup nest constructed on conifer or hardwood in coniferous or mixed hardwood forests.

3–50 feet

April through July; single or double brood.

Clutch incubated for approximately 13 days; altricial young fledge at 14–15 days.

75

30–75

15–30

Lesser Goldfinch

Spinus psaltria

Cup nests in trees and shrubs in a variety of open habitats including oak woodlands, mixed coniferous forests, riparian woodlands, chaparral, agricultural and suburban habitats.

3–36 feet

April through July; single or double brood.

Clutch incubated for approximately 12 days by female; altricial young fledge at 11 days.

75

30–75

15–30

Lawrence's Goldfinch

Spinus lawrencei

Cup nests in scattered trees in oak woodlands and savannahs.

3–40 feet

April through July; single or (rarely) double brood

Clutch incubated for 12–13 days by female; altricial young fledge at approximately 11 days.

75

30–75

15–30

American Goldfinch

Spinus tristis

Cup nests in a variety of shrubs in variety of open habitats including ruderal fields and grasslands with shrub component nearby.

3–10 feet

April through August; single or double brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 11–17 days.

75

30–75

15–30

Evening Grosbeak

Coccothraustes vespertinus

Cup nests in fir or other conifers in coniferous forests.

30–60 feet

June through August; single or (rarely) double brood.

Clutch incubated for 12–14 days by female; altricial young fledge at 13–14 days.

75

30–75

15–30

a Consultation recommended to perform work within the standard buffer. Confer internally on avoidance and minimization approach.

b The 1,320-foot (0.25-mile) buffer applies to the highest noise level category (90 dB or greater measured at 50 feet). Smaller buffers may be appropriate based on the noise levels of the project. Biologists should follow the methodology found in Estimating the Effects of Auditory and Visual Disturbance to Northern Spotted Owls and Marbled Murrelets in Northwestern California (U.S. Fish and Wildlife Service 2006) to determine the noise level and appropriate buffer for their specific project.

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