INITIAL STUDY/MITIGATED NEGATIVE DECLARATION PACIFIC GAS & ELECTRIC COMPANY LINE 057A-1 MCDONALD ISLAND TO PALM TRACT PIPELINE DECOMMISSIONING PROJECT May 2021 Lead Agency: California State Lands Commission 100 Howe Avenue, Suite 100 South Sacramento, California 95825 Applicant: Pacific Gas & Electric Company 5555 Florin Perkins Road, Room 128D Sacramento, CA 95826 MISSION STATEMENT The California State Lands Commission provides the people of California with effective stewardship of the lands, waterways, and resources entrusted to its care based on the principles of equity, sustainability, and resiliency, through preservation, restoration, enhancement, responsible economic development, and the promotion of public access. CEQA DOCUMENT WEBSITE www.slc.ca.gov/ceqa/ Geographic Location (Western Bank) Latitude: 37°58’6” N Longitude: 121°34’25” W WGS84 Datum Cover Photo: (Photo courtesy of Google Earth) Table of Contents TABLE OF CONTENTS LIST OF TABLES ......................................................................................................... v LIST OF FIGURES....................................................................................................... vi LIST OF ABBREVIATIONS AND ACRONYMS ......................................................... vii EXECUTIVE SUMMARY ........................................................................................ ES-1 1.0 PROJECT AND AGENCY INFORMATION ................................................... 1-1 1.1 PROJECT TITLE ............................................................................................ 1-1 1.2 LEAD AGENCY AND PROJECT SPONSOR ................................................. 1-1 1.3 PROJECT LOCATION ................................................................................... 1-1 1.4 ORGANIZATION OF THE MITIGATED NEGATIVE DECLARATION ............ 1-1 1.5 PROJECT BACKGROUND AND OBJECTIVES ............................................ 1-5 1.6 PUBLIC REVIEW AND COMMENT ............................................................... 1-6 1.7 APPROVALS AND REGULATORY REQUIREMENTS .................................. 1-6 1.7.1 California State Lands Commission .............................................. 1-6 1.7.2 Other Agencies ............................................................................. 1-7 2.0 PROJECT DESCRIPTION ............................................................................. 2-1 2.1 PIPELINE SEGMENTS PROPOSED FOR DECOMMISSIONING ................. 2-1 2.1.1 Segment 1 – Latham Slough Submarine Pipeline Crossing .......... 2-1 2.1.2 Segment 2 – Mildred Island Submerged (Originally Terrestrial) Pipeline Segment .......................................................................... 2-4 2.1.3 Segment 3 – Middle River Submarine Pipeline Crossing .............. 2-7 2.1.4 Segment 4 – Old River Submarine Pipeline Crossing ................. 2-10 2.2 Pipeline Decommissioning Methodology ...................................................... 2-13 2.2.1 Pre-Project Plans and Surveys ................................................... 2-13 2.2.2 Pipeline Pigging and Flushing ..................................................... 2-13 2.2.3 Cementing (Slurry and Abandonment In-Place as Applicable) ... 2-16 2.2.4 Pipeline Removal ........................................................................ 2-17 2.2.5 Site Restoration and Demobilization ........................................... 2-19 2.2.6 Post-Project Surveys and Reporting ........................................... 2-20 2.3 Equipment Requirements ............................................................................. 2-20 2.4 Schedule ................................................................................................... 2-22 2.5 PRE-PROJECT PREPARATION ACTIVITIES AND SURVEYS................... 2-22 2.5.1 Project APMs .............................................................................. 2-22 3.0 ENVIRONMENTAL CHECKLIST AND ANALYSIS ....................................... 3-1 3.1 AESTHETICS ................................................................................................. 3-3 May 2021 i PG&E L-057A-1 McDonald Island to Palm Tract Pipeline Decommissioning Project MND Table of Contents 3.1.1 Environmental Setting ................................................................... 3-3 3.1.2 Regulatory Setting ......................................................................... 3-3 3.1.3 Impact Analysis ............................................................................. 3-4 3.1.4 Mitigation Summary ...................................................................... 3-6 3.2 AGRICULTURE AND FORESTRY RESOURCES ......................................... 3-7 3.2.1 Environmental Setting ................................................................... 3-7 3.2.2 Regulatory Setting ......................................................................... 3-9 3.2.3 Impact Analysis ........................................................................... 3-10 3.2.4 Mitigation Summary .................................................................... 3-12 3.3 AIR QUALITY ............................................................................................... 3-13 3.3.1 Environmental Setting ................................................................. 3-13 3.3.2 Regulatory Setting ....................................................................... 3-19 3.3.3 Impact Analysis ........................................................................... 3-20 3.3.4 Mitigation Summary .................................................................... 3-22 3.4 BIOLOGICAL RESOURCES ........................................................................ 3-23 3.4.1 Environmental Setting ................................................................. 3-23 3.4.2 Regulatory Setting ....................................................................... 3-43 3.4.3 Impact Analysis ........................................................................... 3-45 3.4.4 Mitigation Summary .................................................................... 3-53 3.5 CULTURAL RESOURCES ........................................................................... 3-54 3.5.1 Environmental Setting ................................................................. 3-54 3.5.2 Regulatory Setting ....................................................................... 3-63 3.5.3 Impact Analysis ........................................................................... 3-64 3.5.4 Mitigation Summary .................................................................... 3-67 3.6 CULTURAL RESOURCES – TRIBAL .......................................................... 3-68 3.6.1 Environmental Setting ................................................................. 3-68 3.6.2 Regulatory Setting ....................................................................... 3-72 3.6.3 Impact Analysis ........................................................................... 3-72 3.6.4 Mitigation Summary .................................................................... 3-73 3.7 ENERGY ................................................................................................... 3-74 3.7.1 Environmental Setting ................................................................. 3-74 3.7.2 Regulatory Setting ....................................................................... 3-74 3.7.3 Impact Analysis ........................................................................... 3-74 3.7.4 Mitigation Summary .................................................................... 3-75 3.8 GEOLOGY, SOILS, AND PALEONTOLOGICAL RESOURCES .................. 3-76 3.8.1 Environmental Setting ................................................................. 3-76 3.8.2 Regulatory Setting ....................................................................... 3-78 3.8.3 Impact Analysis ........................................................................... 3-79 PG&E L-057A-1 McDonald Island to Palm Tract ii May 2021 Pipeline Decommissioning Project MND Table of Contents 3.8.4 Mitigation Summary .................................................................... 3-82 3.9 GREENHOUSE GAS EMISSIONS ............................................................... 3-83 3.9.1 Environmental Setting ................................................................. 3-83 3.9.2 Regulatory Setting ....................................................................... 3-84 3.9.3 Impact Analysis ........................................................................... 3-86 3.9.4 Mitigation Summary .................................................................... 3-87 3.10 HAZARDS AND HAZARDOUS MATERIALS ............................................... 3-88 3.10.1 Environmental Setting ................................................................. 3-88 3.10.2 Regulatory Setting ....................................................................... 3-89 3.10.3 Impact Analysis ........................................................................... 3-90 3.10.4 Mitigation Summary .................................................................... 3-94 3.11 HYDROLOGY AND WATER QUALITY ........................................................ 3-95 3.11.1 Environmental Setting ................................................................. 3-95 3.11.2 Regulatory Setting ......................................................................