NTSB Safety Recommendation P-21-017

NTSB safety recommendation P-21-017.

TO PACIFIC GAS & ELECTRIC: Complete the integration of detailed location data into your hydraulic modeling software so that this information is readily available for all system assets when developing a valve isolation plan.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 2021-08-10

Adopted Date: 2021-07-26

Overall Date Closed: 2022-04-21

Synopsis: On February 6, 2019, at 1:07 p.m. local time, the excavator operator for a third-party contractor, Kilford Engineering Inc., impacted a Pacific Gas & Electric Company (PG&E) branch connection with a mini excavator trenching bucket attachment during mechanical excavation for fiberoptic conduit installation, which resulted in the release and ignition of natural gas. The accident occurred in the Richmond District of San Francisco, California. A nearby restaurant with a rental unit above caught fire. There were no injuries. Estimated damages to nearby buildings and the pipeline system exceeded $10 million. The National Transportation Safety Board (NTSB) determined that the probable cause of the accident was the failure of the Kilford operator and spotter to follow safe excavation practices within the tolerance zone, which resulted in the mini excavator trenching bucket attachment impacting the pipeline’s branch connection. The investigators focused on the safety issues of third-party excavation damage to buried natural gas pipelines, enforcement challenges of California’s damage prevention law, PG&E’s data integration gaps during the development of the valve isolation plan, and insufficient joint emergency response planning between PG&E and San Francisco emergency response agencies. As a result of the investigation, the NTSB makes one recommendation each to the San Francisco Police Department, Fire Department, and Department of Emergency Management and two recommendations to PG&E.

Probable Cause: The National Transportation Safety Board determines that the probable cause of the February 6, 2019, release of natural gas from the Pacific Gas & Electric Company distribution pipeline and the subsequent fire was the failure of the Kilford Engineering Inc. operator and spotter to follow safe excavation practices within the tolerance zone, which resulted in the mini excavator trenching bucket attachment impacting the pipeline’s branch connection.

Ntsbnumber: PLD19MR001

Report Number: PAR-21-02

Addressee Name: Pacific Gas and Electric Company

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 2022-04-21

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 2021-08-10

Communication Type: Transmittal Letter

Communication Contents: The National Transportation Safety Board (NTSB) is an independent federal agency charged by Congress with investigating every civil aviation accident in the United States and significant accidents in other modes of transportation—railroad, highway, marine, and pipeline. We determine the probable cause of the accidents and issue safety recommendations aimed at preventing future accidents. In addition, we carry out special studies concerning transportation safety and coordinate the resources of the federal government and other organizations to provide assistance to victims and their family members affected by major transportation disasters. The attached letter from the NTSB Chairman provides information about the NTSB’s July 27, 2021, report, Pacific Gas & Electric Third-Party Line Strike and Fire, San Francisco, California, February 6, 2019. The details of this accident investigation and the resulting safety recommendation may be found in the attached report, which can also be accessed at http://www.ntsb.gov. For more information about NTSB and our recommendation process, please see the attached one-page summary. The NTSB is vitally interested in these recommendations because they are designed to prevent accidents and save lives. We would appreciate a response within 90 days of the date of this letter, detailing the actions you have taken or intend to take to implement these recommendations. When replying, please refer to the safety recommendation by number (for example, P-21-16 and P-21-17). We encourage you to submit your response to ExecutiveSecretariat@ntsb.gov. If your reply exceeds 20 megabytes, including attachments, please e mail us at the same address for instructions on how to send larger documents. Please do not submit both an electronic copy and a hard copy of the same response. All communications regarding safety recommendations will be stored by the NTSB and viewable by the public. Please do not send privileged or confidential communications in response to this recommendation. Responses marked as confidential or privileged (or similar designations) will be considered nonresponsive. If you have concerns about this protocol, please contact us at ExecutiveSecretariat@ntsb.gov. The National Transportation Safety Board (NTSB) is an independent federal agency charged by Congress with investigating every civil aviation accident in the United States and significant accidents in other modes of transportation—railroad, highway, marine, and pipeline. We determine the probable cause of the accidents and issue safety recommendations aimed at preventing future accidents. In addition, we carry out special studies concerning transportation safety and coordinate the resources of the federal government and other organizations to assist victims and their family members affected by major transportation disasters. We are providing the following information to urge the Pacific Gas & Electric Company (PG&E) to act on the safety recommendations in this letter because we believe your organization can help reduce the risk of future accidents. For more information about the NTSB and our recommendation process, please see the attached one-page summary. This letter provides information about our July 27, 2021, report, Pacific Gas & Electric Third-Party Line Strike and Fire, San Francisco, California, February 6, 2019. The details of this accident investigation and the resulting safety recommendations can be found in the attached report, which can also be accessed at http://www.ntsb.gov. As a result of this investigation, we identified the following safety issues: • Third-party excavation damage to buried natural gas pipelines. • Enforcement challenges of California’s damage prevention law. • PG&E’s data integration gaps during the development of the valve isolation plan. • Insufficient joint emergency response planning between PG&E and San Francisco, California, emergency response agencies. Accordingly, the NTSB makes the following safety recommendations to PG&E. Additional information regarding these recommendations can be found in the noted sections of the report. • In collaboration with the San Francisco Police Department, San Francisco Fire Department, and the San Francisco Department of Emergency Management, establish an agreement to provide a coordinated response and reduce response times for your crews to arrive at the scene of a pipeline accident. (P-21-16) (See section 2.5.) • Complete the integration of detailed location data into your hydraulic modeling software so that this information is readily available for all system assets when developing a valve isolation plan. (P-21-17) (See section 2.4) The NTSB is vitally interested in these recommendations because they are designed to prevent accidents and save lives. We would appreciate a response within 90 days of the date of this letter, detailing the actions you have taken or intend to take to implement these recommendations. When replying, please refer to the safety recommendations by number R-21-16 or R-21-17. We encourage you to submit your response to ExecutiveSecretariat@ntsb.gov. If your reply, including attachments, exceeds 20 megabytes, please e mail us at the same address for instructions on how to send larger documents. Please do not submit both an electronic copy and a hard copy of the same response.

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 2022-01-05

Communication Type: Official Correspondence

Communication Contents: We note that you have added a geographic information system (GIS) layer in your gas distribution mapping application (GDGIS) that provides detailed location information so field crews can create isolation plans in the event of a gas dig-in. We further note that you are currently in the process of integrating emergency shutdown zone (ESZ) information into the GDGIS application, which will further improve your ability to provide detailed location information for valve isolation plans that require a full ESZ or multiple zones. We understand that you anticipate completing this project in 2022. We believe that your planned actions, once completed, will satisfy our recommendation. Pending the integration of detailed location data for all system assets into your hydraulic modeling software, Safety Recommendation P-21-17 is classified OPEN-- ACCEPTABLE RESPONSE.

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 2022-04-21

Communication Type: Official Correspondence

Communication Contents: We note that you have fully integrated emergency shutdown zone (ESZ) information into your gas distribution mapping (GDGIS) application, which will further improve your ability to provide detailed location information for valve isolation plans that require a full ESZ or encompass multiple zones. We note that all your field personnel have access to the GDGIS application via their mobile tablets, and that your Operations and Maintenance Manual provides instruction on how to operate the valves. We further note that you communicated these changes and provided guidance to all your affected work groups. These actions satisfy Safety Recommendation P-21-17, which is classified CLOSED-- ACCEPTABLE ACTION.

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 2021-11-04

Communication Type: Official Correspondence

Communication Contents: -From Adam Wright, Executive Vice President, Operations and Chief Operating Officer, Pacific Gas and Electronic Company: Thank you for the opportunity to respond to the National Transportation Safety Board’s (NTSB) safety recommendations of August 10, 2021 resulting from its investigation of the February 6, 2019 gas dig-in incident at Parker and Geary Streets in San Francisco, California, and for providing the NTSB’s July 27, 2021 report. 1 There is nothing more important at Pacific Gas and Electric Company (PG&E) than the safety of the public and our employees, and these safety recommendations will help us continue to make improvements in these vital areas. As a result of the After-Action Review PG&E performed following the event, we have made improvements to our Damage Prevention program within San Francisco and across the State of California to reduce the risk of future accidents. One of these efforts was to reach out to the primary contractors from that event, Verizon and Mastec, as well as their sub-contractors, to hold safe digging awareness and 811 workshops. PG&E’s Damage Prevention team held meetings with Verizon, Mastec, and their sub-contractors on 8 occasions between 10/04/2019 and 06/25/2020 for 811 dig safe training. In addition, we have also conducted 811 training with Mastec an additional 5 times in 2021 emphasizing the 811 process, California excavation laws, high priority facilities, and safe excavation best practices. The following responses provide a detailed summary of the progress PG&E has made towards implementing the NTSB’s two safety recommendations (P-21-016 and P-21-017). PG&E’s Response to NTSB Recommendation P-21-17, dated August 10, 2021 PG&E’s Gas Distribution Geographic Information System (GDGIS) mapping application contains our system asset information and the associated detailed location data. PG&E has incorporated the use of a GDGIS layer with detailed location information for the field crews in creating isolation plans in the event of a gas dig-in. To further enhance GDGIS and to accomplish the intent of the NTSB’s Recommendation, PG&E is currently integrating the Emergency Shutdown Zone (ESZ) information into the GDGIS application. ESZs are pre-designed isolation plans for a gas distribution system or portion of a distribution system that can be shut off with minor or minimal hydraulic impacts to surrounding gas systems. Integrating our ESZ information into GDGIS will improve our ability to provide this detailed location information for valve isolation plans requiring the use of a full ESZ or multiple zones. This project is expected to be completed by the first quarter of 2022.

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 2022-03-18

Communication Type: Official Correspondence

Communication Contents: -From Adam L Wright, Executive Vice President, Operations and Chief Operating Officer, Pacific Gas and Electric Company: Pacific Gas and Electric Company (PG&E) respectfully provides the attached update on its implementation of the National Transportation Safety Board’s (NTSB) Safety Recommendation P-21-017, resulting from the NTSB’s investigation of the February 6, 2019, gas dig-in incident at Parker and Geary Streets in San Francisco, California. PG&E provided its initial response to the NTSB’s Safety Recommendations P-21-016 and P-21-017 on August 10, 2021. On January 5, 2022, the NTSB responded to PG&E’s initial response classifying P-21- 016 as “Closed-Acceptable Action”, and P-21-017 as “Open-Acceptable Response.” The attached update summarizes our actions to integrate Emergency Shutdown Zones (ESZ) into our gas distribution mapping application (GDGIS), completing P-21-017. We welcome any questions or requests for additional information the NTSB may have on PG&E’s implementation of Recommendation P-21-017. Safety Recommendation P-21-017 Complete the integration of detailed location data into your hydraulic Modeling software so that this information is readily available for all system assets when developing a valve isolation plan. PG&E’s Initial Response to NTSB Recommendation P-21-017, dated August 10, 2021 PG&E’s Gas Distribution Geographic Information System (GDGIS) mapping application contains our system asset information and the associated detailed location data. PG&E has incorporated the use of a GDGIS layer with detailed location information for the field crews in creating isolation plans in the event of a gas dig-in. To further enhance GDGIS and to accomplish the intent of the NTSB’s Recommendation, PG&E is currently integrating the Emergency Shutdown Zone (ESZ) information into the GDGIS application. ESZs are pre-designed isolation plans for a gas distribution system or portion of a distribution system that can be shut off with minor or minimal hydraulic impacts to surrounding gas systems. Integrating our ESZ information into GDGIS will improve our ability to provide this detailed location information for valve isolation plans requiring the use of a full ESZ or multiple zones. This project is expected to be completed by the first quarter of 2022. PG&E’s Update on Completion of NTSB Recommendation P-21-017 As of December 6, 2021, PG&E fully completed integrating the Emergency Shutdown Zone (ESZ) information into the GDGIS application, which will further improve our ability to provide detailed location information for valve isolation plans that require a full ESZ or multiple zones. Shutdown strategies are developed in the hydraulic modeling software with an overlay on the GDGIS system for confirmation. Once isolation points are confirmed in the hydraulic software, these are imported into a layer in GDGIS to communicate the real-world physical location of the isolation point to field personnel. All field personnel have access to our GDGIS application via their mobile tablet and as part of our O&M manual they have instruction on how to operate the valves. The annual distribution model maintenance includes comparing the hydraulic model against GDGIS which is our system of record, to ensure alignment. These changes and guidance were communicated to all affected work groups on December 6, 2021