APPENDIX K PIPELINE RISK ANALYSIS Pipeline Risk Analysis Mountain House Specific Plan III San Joaquin County, California June 2004 J House Environmental Site Assessment (cid:151) Soil & Water Remediation (cid:151) Safety Risk Analysis Pipeline Risk Analysis Mountain House Specific Plan III San Joaquin County, California June 4, 2004 Prepared for: EDAW, Inc. 2022 J Street Sacramento, California 95814 Prepared by: J House Environmental 220 Hidden Creek Drive Auburn, California 95603 TABLE OF CONTENTS Page INTRODUCTION..........................................................................................................................1 Purpose and Scope...................................................................................................................1 Report Organization...................................................................................................................1 SETTING......................................................................................................................................3 Study Area Development Plans.................................................................................................3 Pipeline Construction Specifications and Operating Parameters..............................................3 Pipeline Operation, Maintenance, and Safety Procedures........................................................4 Historic Pipeline Incidents..........................................................................................................5 RISK ANALYSIS...........................................................................................................................7 Event Identification....................................................................................................................7 Probability/Frequency Analysis..................................................................................................8 Consequence Analysis............................................................................................................10 Estimated Individual Risk.........................................................................................................12 RISK MANAGEMENT.................................................................................................................14 ACCEPTABLE LEVEL OF INDIVIDUAL RISK...........................................................................17 CONCLUSIONS AND RECOMMENDATIONS...........................................................................19 REFERENCES...........................................................................................................................21 FIGURES Figure 1..............................................................................................................Site Location Map Figure 2............................................................................................................................Site Plan Figure 3 ..........................................................................................................Pipeline Risk Zones TABLES Table 1........................................................................................................Pipeline Specifications Table 2.................................................. Estimated Individual Risk for Land Uses Along Pipelines Table 3........................................................................Individual Risk Values for Various Hazards Table 4.................................................. Recommended Setbacks for Land Uses Along Pipelines APPENDICES APPENDIX A.....................................Information Provided by Pacific Gas and Electric Company APPENDIX B .................................................Information Provided by Coates Field Service, Inc. APPENDIX C............................................ Information Provided by California State Fire Marshall APPENDIX D ..........................Quantitative Risk Analysis Performed by Quest Consultants, Inc. INTRODUCTION This report presents the results of the pipeline risk analysis performed by J House Environmental for Mountain House Specific Plan III (SP III). The study area consists of approximately 900 acres located within the Mountain House Master Plan area in southwest San Joaquin County, California (Figure 1). The study area includes approximately 758 of the 812 acres that comprise Specific Plan III, and an approximately 142-acre parcel located adjacent to the southeast boundaries of SP III. The existing Grant Line Village residential neighborhood, located in the northwest portion of SP III, is not included in the study area (Figure 2). Two natural gas pipelines and a crude oil pipeline are located in a utility corridor that traverses the study area (Figure 2). Natural gas pipelines are also located within the Mountain House Parkway and Von Sosten Road right-of-ways, immediately east of the study area (Figure 2). The natural gas pipelines are owned and operated by Pacific Gas and Electric Company (PG&E). The crude oil pipeline is owned and operated by Chevron Pipe Line Company (CPL). Purpose and Scope The purpose of the risk analysis is to identify potential safety hazards associated with the natural gas pipelines and crude oil pipeline and to estimate risks associated with development in proximity to the pipelines. Recommendations for development setbacks for land uses planned along the pipeline alignments are provided based on the risk analysis. The risk analysis is based on information obtained from PG&E, CPL, and the California State Fire Marshall, Pipeline Safety Program (CSFM) regarding construction specifications, operating parameters, and inspection and maintenance procedures for the subject pipelines. Potential risks associated with pipeline leak and rupture incidents are estimated based on: 1) an identification of events that could lead to pipeline failure; 2) an assessment of the probability or frequency of these events occurring; and 3) an evaluation of the consequences that could result from a pipeline failure. Industry literature and statistics provide a basis for the event identification and probability analyses. Computer modeling and engineering calculations are used to complete the consequence analysis and to estimate the annual individual risk of fatality at varying distances from the subject pipelines. Report Organization The remainder of this report is organized into the following sections: • Setting; • Risk Analysis; • Risk Management; • Acceptable Level of Individual Risk; 1 • Conclusions and Recommendations; and • References. Supporting documentation is included in attached appendices. 2 SETTING This section presents a description of the study area, construction specifications and operating parameters for the subject pipelines, and information regarding PG&E’s and CPL’s operation, maintenance, and safety procedures. Results of a records search for historic pipeline incidents in the vicinity of the study area are also presented in this section. Study Area Development Plans The SP III Initial Study (EDAW, 2003) and the SP III Land Use Plan (EDAW, 2004) present a concept plan that includes residential, office/commercial/light industrial, elementary school/community facility, Delta Community College, and open space/recreational development within the study area (Figure 2). The specific development layout for each use area has not yet been determined, and drainage and grading plans for the study area have not been finalized. Pipeline Construction Specifications and Operating Parameters Two utility corridors that contain underground pipelines are located in and around the study area. For purposes of discussion in this report, the utility corridors are identified as follows (Figure 2): • Corridor #1: Combined PG&E/CPL corridor that contains two natural gas pipelines (L401 and L002) and one crude oil pipeline (CSFM 0499). • Corridor #2: PG&E corridor along Mountain House Parkway and Von Sosten Road. Contains natural gas pipeline L162A, which is fed by L401 from a point south of I-205, and continues east along Von Sosten Road. Contains natural gas pipeline L176, which is fed by L162A and extends along Mountain House Parkway north of Von Sosten Road. Table 1 presents a summary of available information on construction specifications and operating parameters for the subject pipelines. According to Mr. Greg Parker, Risk Management Technical Specialist with PG&E, pipeline L401 is a main natural gas transmission line for California. This 36-inch diameter line operates at a pressure of 1040 pounds per square inch gage (psig), which represents a hoop stress of 59.96 percent (%) of the specified minimum yield strength (SMYS). L401 is part of the PG&E Backbone Gas Transmission System that runs from Oregon to Arizona (California Energy Commission, 2001). Pipeline L401 currently has a Class 2 location designation. A Class 2 location is: 1) any class location unit (an area that extends 220 yards on either side of the centerline of any continuous one mile length of pipeline) that has more than 10 but fewer than 46 buildings intended for human occupancy (Code of Federal Regulations, Title 49 [CFR 49] Part 192.5). 3 Pipelines L002, L162A, and L176 are also part of PG&E’s California natural gas transmission system. L002 is a 26-inch diameter line that operates at 890 psig, which represents a hoop stress of 59.96% SMYS. L162A is a 10.75-inch line that operates at 365 psig (24.85% SMYS) and L176 is a 6.625-inch diameter line that operates at 365 psig (21.44% SMYS). Line L162A currently has a Class 2 location designation, as described above for L401. Lines L002 and L176 currently have a Class 1 location designation. A Class 1 location is: 1) an offshore area; or 2) any class location unit that has 10 or fewer buildings intended for human occupancy (CFR 49 Part 192.5). According to Mr. Parker, L401, L002, L162A, and L176 are constructed of welded steel and have cathodic protection systems. A facsimile from Mr. Parker that presents information on the subject pipelines is presented in Appendix A. Mr. Larry Whitehead and Mr. Ernie Browning of CPL were contacted to obtain details regarding the crude oil pipeline that traverses the study area. The request for information was forwarded to Mr. Mark Zahn of Coates Field Service, Inc. (Coates), contract right of way agent for CPL. According to Coates, the KLM (Kettleman-Los Medanos) crude oil pipeline was installed in 1945 and has a diameter of 18-inches. The pipeline is constructed of welded carbon steel. Coates has indicated that additional details regarding construction and operation of the CPL crude oil pipeline are company confidential and are not available for release to the public. The information provided by Coates is presented in Appendix B. Mr. Bob Gorham, Supervising Pipeline Safety Engineer with CSFM, was contacted for additional public information on the CPL pipeline. CSFM regulates the safety of intrastate hazardous liquid transportation pipelines and acts as an agent of the Federal Department of Transportation, Office of Pipeline Safety (OPS) concerning the inspection of interstate pipelines. According to CSFM, the subject pipeline, CSFM# 0499 KLMR, was installed between 1942 and 1946 and extends from Los Banos to Los Medanos. The 18-inch diameter pipeline has an impressed current cathodic protection system. The maximum operating pressure for this pipeline is reported as 920 psig. Information provided by Mr. Gorham is presented in Appendix C. Pipeline Operation, Maintenance, and Safety Procedures The PG&E natural gas pipelines and the CPL crude oil pipeline are constructed, operated, and maintained in accordance with state and federal regulations set forth in CFR 49 Parts 190, 191, 192, and 195; California Public Utilities Commission General Order No. 112-E; and the California Pipeline Safety Act of 1981 (California Government Code). Requirements and procedures established in these regulations to safeguard health, property, and public welfare include the following: • Procedural manuals for operation, maintenance, and emergencies, including an emergency contingency plan, are maintained; 4