P-21-014 - NTSB Safety Recommendation P-21-014 | Regulus

NTSB safety recommendation P-21-014.

TO THE GAS PIPING TECHNOLOGY COMMITTEE: Develop guidance that identifies steps that gas distribution operators can take to ensure that their gas distribution integrity management program, at a minimum, appropriately considers: (1) threats that degrade a system over time, and (2) the increased risk that can result from factors that simultaneously increase the likelihood and consequence of failure.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 2021-02-08

Adopted Date: 2021-01-12

Overall Date Closed: 2023-07-03

Synopsis: On February 23, 2018, at 6:38 a.m. local time, a natural gas–fueled explosion occurred at 3534 Espanola Drive, Dallas, Texas. The residence sustained major structural damage, but when first responders arrived on scene at 6:44 a.m., they observed no smoke or fire. Four family members were injured, and one was killed in the explosion. Following the explosion, National Transportation Safety Board (NTSB) investigators located a through-wall crack in the 71 year old natural gas main that served the residence. In the 2 days before this explosion, two gas-related incidents occurred on the same block at houses that were served by the same natural gas main, each resulting in significant structural damage and burn injuries to one occupant. The first occurred on February 21, 2018, at 5:49 a.m., and resulted in one injury involving second-degree burns and significant structural damage to 3527 Durango Drive. The second incident occurred on February 22, 2018, at 10:21 a.m., and resulted in one injury involving second-degree burns and significant structural damage to 3515 Durango Drive. As a result of this investigation, the NTSB issued new safety recommendations to the Pipeline and Hazardous Materials Safety Administration, the Railroad Commission of Texas, the Dallas Fire-Rescue Department, Atmos Energy Corporation, and the Gas Piping Technology Committee. The NTSB is also reiterating safety recommendations to the International Code Council, the National Fire Protection Association, and the Gas Technology Institute

Probable Cause: The National Transportation Safety Board determines that the probable cause of the explosion at 3534 Espanola Drive was the ignition of an accumulation of natural gas that leaked from the gas main that was damaged during a sewer replacement project 23 years earlier and was undetected by Atmos Energy Corporation’s investigation of two related natural gas incidents on the 2 days prior to the explosion. Contributing to the explosion was Atmos Energy Corporation’s insufficient wet weather leak investigation procedures. Contributing to the severity of the explosion was Atmos Energy Corporation’s inaction to isolate the affected main and evacuate the houses. Contributing to the degradation of the pipeline system was Atmos Energy Corporation’s inadequate integrity management program.

Ntsbnumber: PLD18FR002

Report Number: PAR-21-01

Addressee Name: American Gas Association, Gas Piping Technology Committee

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 2023-07-03

Addressee Acronym: GPTC

Addressee Organization Type: A-Associations

Communication Date: 2021-02-08

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 January 12, 2021, report Atmos Energy Corporation Natural Gas-Fueled Explosion, Dallas, Texas, February 23, 2018, PAR-21/01. 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-21-13 and -14). 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 Gas Piping Technology Committee (GPTC) to act on the safety recommendation 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 the National Transportation Safety Board’s (NTSB) January 12, 2021, report Atmos Energy Corporation Natural Gas-Fueled Explosion, Dallas, Texas, February 23, 2018, PAR-21/01. The details of this accident investigation and the resulting safety recommendations may 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: • Incident investigation. Neither Dallas Fire-Rescue Department (DFR) nor Atmos Energy Corporation (Atmos) identified the causes of the two incidents that occurred in the days immediately preceding the explosion. DFR arson investigators and Atmos technicians did not effectively investigate, communicate, or collaborate to determine the cause of either incident. Further, Atmos did not gather enough evidence to determine if gas migrated from their piping and fueled the first two incidents. • Leak investigations and repairs. Atmos dedicated significant resources to its response following the second incident, finding 13 leaks determined to present an existing or probable future hazard. However, none of its employees questioned the integrity of the system. As a result, Atmos did not take appropriate action to secure the safety of the area and its residents. This was attributed, in part, to inadequate procedures for performing leak investigations in wet weather conditions. • Methane detection. Although Atmos added odorant to its gas distribution system in a manner consistent with Pipeline and Hazardous Materials Safety Administration (PHMSA) regulations, none of the residents at any of the affected homes smelled gas. Although odorant can act as an early warning of a gas release to prevent an explosion and fire, it is known to become depleted if it travels through soil. • Incident reporting. Incident reporting requirements mandated by the PHMSA rely on the judgement of the operator to determine whether an incident resulted from a leak in their system and do not specify the level of investigation necessary to make the determination. While operators have an option to report events that may have been caused by their system, Atmos relied on an incomplete investigation to support its position not to report the first two incidents. Accordingly, the NTSB makes the following safety recommendations to the GPTC. Additional information regarding these recommendations can be found in the noted sections of the report. • Develop additional guidance that identifies steps gas distribution operators can take to safely respond to leaks, fires, explosions, and emergency calls, considering the limitations due to wet weather conditions, that includes: (1) criteria for when to shut down or isolate gas distribution systems, pressure test main and service lines, and begin evacuations; (2) leak investigation methods that are reliable in wet weather, (3)require an alternate safe response, such as an evacuation when reliable leak investigations are not possible due to wet weather, and (4) leak investigations that assess all viable gas migration paths, including granular backfill and crawlspaces. (P-21-13) (See section 2.4.) • Develop guidance that identifies steps that gas distribution operators can take to ensure that their gas distribution integrity management program, at a minimum, appropriately considers (1) threats that degrade a system over time, and (2) the increased risk that can result from factors that simultaneously increase the likelihood and consequence of failure. (P 21 14) (See section 2.7.) 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(s) by number (Safety Recommendation(s) P 21 13 and -14). 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. Please do not submit both an electronic copy and a hard copy of the same response.

Addressee Acronym: GPTC

Addressee Organization Type: A-Associations

Communication Date: 2021-04-21

Communication Type: Official Correspondence

Communication Contents: -From Leticia (Letty) Quezada, Chairman of GPTC: The Gas Piping Technology Committee (GPTC) consists of approximately 100 members with technical expertise in natural gas distribution, transmission, and gathering systems. GPTC is an independent technical committee by the American National Standards Institute (ANSI) as ANSI/GPTC Z380. The GPTC has been providing guidance to operators of natural gas systems to help comply with the federal regulations since their inception in 1970. Guidance is published in the GPTC Guide for Gas Transmission and Distribution Piping Systems. Thank you for your letter, dated February 8, 2021, regarding the National Transportation Safety Board’s (NTSB) Safety Recommendations P-21-13 and P-21-14, which both arose from the NTSB investigation of the February 23, 2018 Atmos Energy Corporation natural gas-fueled explosion in Dallas Texas. We appreciate the NTSB’s recognition that GPTC is a committee that can make or influence change to help reduce the risk of accidents. The two recommendations to the GPTC are as follows: P-21-13: Develop additional guidance that identifies steps gas distribution operators can take to safely respond to leak, fires, explosions, and emergency calls, considering the limitations due to wet weather conditions, that includes: (1) criteria for when to shut down or isolate gas distributions systems, pressure test main and service lines and begin evacuations; (2) leak investigation methods that are reliable in wet weather, (3) require an alternate safe response, such as evacuation when reliable leak investigations are not possible due to wet weather, and (4) leak investigations that assess all viable gas migration paths, including granular backfill and crawlspaces. P-21-14: Develop guidance that identifies steps that gas distribution operators can take to ensure that their gas distribution integrity management program, at a minimum, appropriately considers (1) threats that degrade a system over time, and (2) the increased risk that can results from factors that simultaneously increase the likelihood and consequence of failure. In response to the recommendations, at the last GPTC meeting held in March 2021, we have created four transactions in accordance with our committee’s Operating Procedures. The transactions have been assigned to various task groups within GPTC While the assigned task groups are actively working the recommendations, we expect to see progress on the transactions at our next meeting in July 2021, click here. All transactions are worked to completion and can achieve outcomes that could include edited or new guide material, closed with the determination that our guide material is adequate and no changes are needed, and/or closed because the transaction is not in line with the committee’s primary purpose, which is: The primary purpose of GPTC Z380.1 "Guide for Gas Transmission, Distribution, and Gathering Piping Systems" (Guide) is to provide assistance to the operator in complying with the intent of the Code of Federal Regulations (CFR) in the performance requirements contained in the Transportation of Natural and Other Gas by Pipelines, Title 49 Subchapter D-Pipeline Safety: Part 191 - Annual Reports, Incident Reports, and Safety-Related Condition Reports; and Part 192 - Minimum Federal Safety Standards (typically referred to hereinafter as the "Regulations"). The Guide includes the Minimum Federal Safety Standards together with the design recommendations, material reference, and recommended practices of the GPTC. The function of the GPTC's guide material is to provide "how to" supplementary recommendations related to the Minimum Federal Safety Standards. The Committee continuously works to pinpoint areas where more guide material could be provided in support of the Minimum Federal Safety Standards and related Regulations. We are aware of the importance of the recommendations and we are tracking the transaction progress closely. Transactions that include edited and new guide material can require several meetings to complete, and as an ANSI committee, we must follow the ANSI process for approval of the new guide material. The GPTC committee meets three times per year, click here to our meeting schedule. Attached is addendum 1. Addendum 1 includes the transactions in their beginning stage of assignment. We will provide the updates to the NTSB on the progress of the four transactions after each GPTC committee meeting. Thank you for the opportunity to respond to the NTSB’s recommendations. If I can provide further information or assistance, feel free to contact me.

Addressee Acronym: GPTC

Addressee Organization Type: A-Associations

Communication Date: 2021-08-23

Communication Type: Official Correspondence

Communication Contents: -From Leticia Quezada, Chairman, Gas Piping Technology Committee: As Chairman of the Gas Piping Technology Committee, (GPTC), I am writing to provide an update on the progress the GPTC has made in response to the NTSB Safety Recommendations P-21-13 and P-21-14, which both arose from the NTSB investigation of the February 23, 2018 Atmos Energy Corporation natural gas-fueled explosion in Dallas Texas. In the original response to the NTSB, the GPTC reported it had created and assigned four transactions (TR 21-21, TR 21-22, TR 21-23, and TR 21-24) to address the NTSB recommendations. We also reported that transactions can require several meetings to complete. The GPTC meets three times per year. As an ANSI Accredited Standards Committee, we must follow ANSI processes and procedures for new guide material. We recognize the importance of the recommendations and we are committed to providing updates to the NTSB after each GPTC committee meeting. The last GPTC meeting took place on July 12 - 142021. At the request of the assigned task groups, during that meeting the GPTC Executive Section voted to combine TR 21-21 and TR 21-22 into TR 21-23. The Origin/Rationale for TR 21-23 was revised to include information from TR 21-21 and TR 21-22. TR 21-23 has been assigned to the Damage Prevention/Emergency Response task group, while TR 21-24 has been assigned to the Operations and Maintenance/Operator Qualification (O&M/OQ) task group. TR 21-21 and TR 21-22 have been closed. Please know that the task groups are actively working the transactions. Based on the work to date, GPTC would like to request an “Open – Acceptable Response” for recommendations P-21-13 and P-21-14. If you have any questions regarding this update or if I can provide further information or assistance, feel free to contact me.

Addressee Acronym: GPTC

Addressee Organization Type: A-Associations

Communication Date: 2022-02-18

Communication Type: Official Correspondence

Addressee Acronym: GPTC

Addressee Organization Type: A-Associations

Communication Date: 2022-06-13

Communication Type: Official Correspondence

Communication Contents: -From Leticia Quezada, Chairman, Gas Piping Technology Committee: As Chairman of the Gas Piping Technology Committee, (GPTC), I am writing to provide an update on the progress the GPTC is making in response to the NTSB Safety Recommendations P-21-13 and P-21-14, which both arose from the NTSB investigation of the February 23, 2018, Atmos Energy Corporation natural gas-fueled explosion in Dallas Texas. The last GPTC meeting took place February 28, 2022, through March 2, 2022. As stated in the previous update, the GPTC has two transactions (TRs) to address the NTSB recommendations. TR 21-23 (Leak Patrols During Inclement Weather) addresses Recommendation P-21-13 and TR 21-24 (Threats that Degrade Systems) addresses Recommendation P-21-14. As an ANSI Accredited Standards Committee, we must follow ANSI processes and procedures for new guide material. At the last meeting, the content for TR 21-23 was reviewed and approved by the Main Body to proceed to letter ballot. TR 21-24 had previously balloted and was being recirculated to address disapprovals from the first ballot. Both TRs were balloted under LB5-2022. TR 21-23 received 4 disapproved votes, while TR 21-24 received 1 disapproved vote. Discussion and attempts at resolving the disapprovals will take place during the upcoming GPTC meeting. Once the disapprovals are resolved, the TRs will be recirculated to the membership for approval of any revised language. We recognize the importance of the recommendations, and we are committed to providing updates to the NTSB after each GPTC committee meeting. The next meeting is scheduled for June 20-22, 2022. Based on the work to date, GPTC would like to request an “Open – Acceptable Response” for recommendations P-21-13 and P-21-14. If you have any questions regarding this update or if I can provide further information or assistance, feel free to contact me.

Addressee Acronym: GPTC

Addressee Organization Type: A-Associations

Communication Date: 2023-04-11

Communication Type: Official Correspondence

Communication Contents: -From Leticia Quezada, Chairman, Gas Piping Technology Committee: As Chairman of the Gas Piping Technology Committee, (GPTC), I am writing to provide an update on the progress the GPTC is making in response to the NTSB Safety Recommendations P-21-13 and P-21-14, which both arose from the NTSB investigation of the February 23, 2018, Atmos Energy Corporation natural gas-fueled explosion in Dallas Texas. The most recent GPTC meeting took place March 6, 2023 – March 9, 2023. As stated in the previous update, the GPTC has two transactions (TRs) to address the NTSB recommendations. TR 21-23 (Leak Patrols During Inclement Weather) addresses Recommendation P-21-13 and TR 21-24 (Threats that Degrade Systems) addresses Recommendation P-21-14. As an ANSI Accredited Standards Committee, we must follow ANSI processes and procedures for new guide material. Following the November 2022 meeting, TR 21-23 was recirculated for a second ballot and received one disapproved vote. To address the disapproval, the ad-hoc task group presented proposed revised language at the March 2023 meeting. At this meeting, the proposed revisions to TR 21-23 were approved to move to another recirculated vote. The ballot was issued on April 3, 2023, and closes on April 24, 2023. Following the November 2022 meeting, TR 21-24 was approved via letter ballot and the content was published in the ANSI/GPTC Z380.1, Guide for Gas Transmission, Distribution, and Gathering Piping Systems, 2022 Edition, Addendum 2, dated February 2023. The revisions made to Guide Material Appendix G-192-8 Distribution Integrity Management Program (DIMP) are contained in sections 3.3 (Additional Information), 4.1 (Primary Threats) and 4.4 (Handling Interactive Threats). See attachment for details of the revisions. We recognize the importance of the recommendations, and we are committed to providing updates to the NTSB after each GPTC committee meeting until the actions are completed. The next meeting is scheduled for July 10, 2023 – July 13, 2023. Based on the work to date, GPTC would like to request an “Open – Acceptable Response” for recommendation P-21-13 and “Closed – Acceptable Action” for recommendation P-21-14. If you have any questions regarding this update or if I can provide further information or assistance, feel free to contact me.

Addressee Acronym: GPTC

Addressee Organization Type: A-Associations

Communication Date: 2024-01-29

Communication Type: Official Correspondence

Communication Contents: -From Leticia Quezada, Chairman, Gas Piping Technology Committee: As Chairman of the Gas Piping Technology Committee, (GPTC), I am writing to provide an update on the progress the GPTC is making in response to the NTSB Safety Recommendations P-21-13 and P-21-14, which arose from the NTSB investigation of the February 23, 2018, Atmos Energy Corporation natural gas-fueled explosion in Dallas Texas (NTSB/PAR-21/01). From your letter of July 3, 2023, the GPTC is pleased to learn that the NTSB has classified recommendation P-21-14 as Closed–Acceptable Action. Following the July 2023 GPTC meeting, the guide material for GPTC TR 21-23 (corresponding to NTSB recommendation P-21-13) was ready for ANSI Public Review. Revisions made to Guide Material are the following and are detailed in the attached file. • GM 192.615, Section 1.3 • GM 192.723, Section 1.4 • GM 192.803, Section 1.2 • Appendices GMA-192-11 and GMA 192-11A, Sections 5.1, 5.2, 5.4, and new section 5.5. The GPTC is an American National Standards Institute (ANSI) committee, must abide by ANSI procedures. As such, on October 6, 2023, ANSI announced the 45-day Public Review of TR 21-23. The ANSI Public Review closed on November 20, 2023, without any comments; therefore, the guide material under TR 21-23 will be incorporated into Addendum 4 to the 2022 Edition of the GPTC Guide. ANSI formally approved Addendum 4 on January 24, 2024 and publication is expected February of 2024. Based on the work to date, the GPTC would like to request a classification of “Closed – Acceptable Action” for recommendation P-21-13. If you have any questions regarding this update or if I can provide further information or assistance, feel free to contact me.

Addressee Acronym: GPTC

Addressee Organization Type: A-Associations

Communication Date: 2021-05-14

Communication Type: Official Correspondence

Communication Contents: We note that, in response to these safety recommendations, at your March 2021 meeting, you created four work items that you assigned to various task groups within the GPTC. These items may result in edited or new guide material, a determination that your guide material is adequate and no changes are needed, or a decision to close the item. We understand that the GPTC meets three times per year, and that you intend to update us on the task groups’ progress after each meeting. Pending the development of the recommended additional guidance, Safety Recommendations P-21-13 and -14 are classified OPEN-- ACCEPTABLE RESPONSE.

Addressee Acronym: GPTC

Addressee Organization Type: A-Associations

Communication Date: 2021-10-04

Communication Type: Official Correspondence

Communication Contents: We note that, in response to these safety recommendations, at your July 12–14, 2021, meeting, you consolidated Transaction (TR) 21-21 through -23 and assigned revised TR 21-23 to your Damage Prevention/Emergency Response Task Group. TR 21-24 remains assigned to your Operations and Maintenance/Operator Qualification Task Group. We are aware that your task groups meet three times each year and follow ANSI processes and procedures. Consolidating and revising the original transactions, as well as your task groups’ continuing work, is responsive to our recommendations. Pending the GPTC’s completion of transactions TR 21-23 and TR 21-24, Safety Recommendations P-21-13 and -14 remain classified OPEN-- ACCEPTABLE RESPONSE. Please update us at ExecutiveSecretariat@ntsb.gov on your progress toward implementing these recommendations, and do not send both an electronic and a hard copy of the same response.

Addressee Acronym: GPTC

Addressee Organization Type: A-Associations

Communication Date: 2022-03-24

Communication Type: Official Correspondence

Communication Contents: We note that at the last GPTC meeting on November 1–3, 2021, the draft content for TR 21-23 (addressing Safety Recommendation P-21-13) was circulated to your membership for their review and comment, and the draft content for TR 21-24 (addressing Safety Recommendation P-21-14) was reviewed and approved by the main body to proceed to letter ballot. We appreciate your regular updates. Pending the GPTC’s completion of TR 21-23 and TR 21-24, Safety Recommendations P-21-13 and -14 remain classified OPEN-- ACCEPTABLE RESPONSE.

Addressee Acronym: GPTC

Addressee Organization Type: A-Associations

Communication Date: 2022-08-23

Communication Type: Official Correspondence

Communication Contents: We note that, at the GPTC meeting held February 28 through March 2, 2022, the content for Transaction (TR) 21-23 (addressing Safety Recommendation P-21-13) was reviewed and approved by the main body to proceed to letter ballot. TR 21-24 (addressing Safety Recommendation P-21-14) had previously been balloted and was being recirculated to address disapprovals from the first ballot. Both TRs were balloted under LB5-2022. TR 21-23 received four disapproved votes, while TR 21-24 received one disapproved vote. We further note that discussion to resolve the disapprovals took place during your June 20 through June 22, 2022, meeting, and revised TRs have been circulated to the membership for approval. We appreciate your regular updates and look forward to receiving the results of your next round of balloting. Pending the GPTC’s completion of TR 21-23 and TR 21-24, Safety Recommendations P-21-13 and -14 remain classified OPEN-- ACCEPTABLE RESPONSE.

Addressee Acronym: GPTC

Addressee Organization Type: A-Associations

Communication Date: 2023-07-03

Communication Type: Official Correspondence

Communication Contents: We note that TR 21-24 (responding to Safety Recommendation P-21-14) was approved via letter ballot and the content has been published in the ANSI/GPTC Z380.1, Guide for Gas Transmission, Distribution, and Gathering Piping Systems, 2022 Edition, Addendum 2, dated February 2023. We note that your revised guidance specifically addresses the need for gas distribution operators to ensure that their integrity management programs consider threats that degrade a system over time as well as handling interactive threats. Accordingly, Safety Recommendation P-21-14 is classified CLOSED-- ACCEPTABLE ACTION.