NTSB Safety Recommendation P-18-009

NTSB safety recommendation P-18-009.

TO NISOURCE: Develop and implement control procedures during modifications to gas mains to mitigate the risks identified during management of change operations. Gas main pressures should be continually monitored during these modifications and assets should be placed at critical locations to immediately shut down the system if abnormal operations are detected. (Urgent)

Priority: CLASS I

Overall Status: Closed - Acceptable Action

Issued Date: 2018-11-15

Adopted Date: 2018-11-14

Overall Date Closed: 2019-07-22

Synopsis: On September 13, 2018, about 4:00 p.m. eastern daylight time, a series of explosions and fires occurred after high-pressure natural gas was released into a low-pressure gas distribution system in the northeast region of the Merrimack Valley, Massachusetts. The distribution system was owned and operated by Columbia Gas of Massachusetts (Columbia Gas), a subsidiary of NiSource, Inc. The system overpressure damaged 131 structures, including at least 5 homes that were destroyed in the city of Lawrence and the towns of Andover and North Andover. Most of the damage was a result of structure fires ignited by gas-fueled appliances. Several structures were destroyed by natural gas explosions. One person was killed and at least 21 individuals, including 2 firefighters, were transported to the hospital. Seven other firefighters received minor injuries.

Probable Cause: The National Transportation Safety Board determines that the probable cause of the overpressurization of the natural gas distribution system and the resulting fires and explosions was Columbia Gas of Massachusetts’ weak engineering management that did not adequately plan, review, sequence, and oversee the construction project that led to the abandonment of a cast iron main without first relocating regulator sensing lines to the new polyethylene main. Contributing to the accident was a low-pressure natural gas distribution system designed and operated without adequate overpressure protection.

Ntsbnumber: PLD18MR003

Report Number: PSR-18-02

Addressee Name: NiSource, Inc. (formerly Columbia Gas)

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 2019-07-22

Addressee Organization Type: P-Private Industry

Communication Date: 2018-11-15

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. On November 14, 2018, the National Transportation Safety Board (NTSB) adopted its safety recommendation report, Natural Gas Distribution System Project Development and Review PSR 18/02. The details of this safety recommendation report may be found at http://www.ntsb.gov. Among the safety recommendations are four urgent safety recommendations issued to NiSource, Inc., which can be found on page 7 of the report. The NTSB is vitally interested in these recommendations because they are designed to prevent accidents and save lives. We would appreciate a response within 30 days, detailing the actions you have taken or intend to take to implement these recommendations. When replying, please refer to the safety recommendations by number. We encourage you to submit your response to correspondence@ntsb.gov. If it exceeds 10 megabytes, including attachments, 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 Organization Type: P-Private Industry

Communication Date: 2018-12-14

Communication Type: Official Correspondence

Communication Contents: -Joe Hamrock, President and CEO: As previously announced, NiSource will be installing automatic pressure control equipment, referred to as “slam-shut” devices, on every low-pressure system across our seven-state operating area. These devices provide another level of control and protection, in that when they sense operating pressure that is too high or too low, they immediately shut down gas to the system. As an additional layer of protection, NiSource will install remote monitoring devices on all low-pressure systems so that our gas control center will see an alarm should the monitoring device indicate a high or low pressure alarm. In the event a system is shut down by the slam-shut devices described above, the remote monitors will enable us to respond more quickly to restore service to customers. NiSource will develop project-specific risk reviews and plans detailing accountability and responsibility for activities during the construction process. This will include individual responsibility for system operation, configuration and monitoring during the construction and “tie-in/gas up” process. The plans will identify the specific tasks (operating valves, monitoring pressure, notifying first responders) required to mitigate risk during critical steps. The plans will also identify follow up actions to be taken in an abnormal condition including identifying critical locations to place assets for immediate shut down if needed.

Addressee Organization Type: P-Private Industry

Communication Date: 2019-03-15

Communication Type: Official Correspondence

Communication Contents: -From Joe Hamrock, President and CEO: NiSource Response: As previously announced, NiSource will be installing automatic pressure control equipment, referred to as "slam-shut" devices, on every low-pressure system across our seven-state operating area. These devices provide another level of control and protection, in that when they sense operating pressure that is too high or too low, they immediately shut down gas to the system. As an additional layer of protection, NiSource will install remote monitoring devices on all low-pressure systems so that our gas control center will see an alarm should the monitoring device indicate a high or low pressure alarm. In the event a system is shut down by the slam-shut devices described above, the remote monitors will enable us to respond more quickly to restore service to customers. NiSource will develop project-specific risk reviews and plans detailing accountability and responsibility for activities during the construction process. This will include individual responsibility for system operation, configuration and monitoring during the construction and "tie-in/gas up" process. The plans will identify the specific tasks (operating valves, monitoring pressure, notifying first responders) required to mitigate risk during critical steps. The plans will also identify follow up actions to be taken in an abnormal condition including identifying critical locations to place assets for immediate shut down if needed. Progress to Date: The project is underway to install automatic pressure control equipment and remote monitoring devices on low-pressure systems. Enhanced tapping and tie-in procedures detailing stakeholder engagement, risk identification, roles and responsibilities and MOC principles provide project-specific risk review for all mainline projects. Next Steps: Continue planning and executing projects to install automatic pressure control equipment and remote monitoring devices on low-pressure systems across NiSource. Develop additional risk reviews and plans for critical steps during a construction project. Implement enhanced tapping and tie-in procedures.

Addressee Organization Type: P-Private Industry

Communication Date: 2019-05-10

Communication Type: Official Correspondence

Communication Contents: -From Joe Hamrock, President and CEO: NiSource has made significant enhancements to its tie-in and tapping procedures, including updates to Gas Standard 1680.010 Tie-Ins and Tapping Pressurized Pipelines, effective February 28, 2019, and the written tie-in plan template, which is required for all design capital mainline projects. We provided copies of both documents to the NTSB during a meeting on April 18. The updates include: •?New tie-in procedure risk assessments, completed through checklists requiring key stakeholder engagement and reviews of the tie-in plan by Engineering, the project execution crew, and Measurement & Regulation. •?A new contingency plan that provides field crews the system knowledge required to perform emergency shut down of the impacted pipeline segments in the event of a hazardous situation. •?Identification of regulator stations impacted by the tie-in procedure and monitoring requirements. •?Enhanced station monitoring requirements for identified MOC activities. •?Clear roles and responsibilities for tasks during the tie-in procedure. •?Sign-off at each significant step of the tie-in procedure signifying completion of steps by the “person in charge.” •?Documentation of pressure gauge readings during the procedure. NiSource has promulgated enhanced procedures encompassing these updates and trained appropriate Engineering, Construction and Operations personnel on these procedures. The Gas Standard and written tie-in plan template provide strength in management of change procedures with respect to changes in the control of energy. Above and beyond the scope of this recommendation, NiSource continues to install automatic shutoff and pressure control devices on low-pressure systems across its footprint. This project also includes installing remote monitoring devices on its low pressure systems to ensure quick response to abnormal system conditions.

Addressee Organization Type: P-Private Industry

Communication Date: 2019-02-19

Communication Type: Official Correspondence

Communication Contents: We note that you plan to install automatic pressure-control equipment, referred to as “slam shut” devices, and remote monitoring devices on every low-pressure gas distribution system across your operating area. We further note that you plan to develop project-specific risk reviews and plans detailing accountability and responsibility during your gas distribution system construction projects. Pending completion of these activities, Safety Recommendation P-18-9 is classified OPEN--ACCEPTABLE RESPONSE.

Addressee Organization Type: P-Private Industry

Communication Date: 2019-07-22

Communication Type: Official Correspondence

Communication Contents: You previously told us that you were installing automatic pressure-control equipment, referred to as “slam shut” devices, and remote monitoring devices on every low-pressure gas distribution system across your operating area. We note that, as mentioned, effective February 28, 2019, you updated to Gas Standard 1680.010, “Tie-Ins and Tapping Pressurized Pipelines,” and now require the use of a written tie-in plan template. These revisions satisfy Safety Recommendation P-18-9, which is classified CLOSED--ACCEPTABLE ACTION.