NTSB Safety Recommendation P-06-001

NTSB safety recommendation P-06-001.

TO THE PENNSYLVANIA PUBLIC UTILITY COMMISSION: Require an analysis of the integrity of butt-fusion joints in National Fuel Gas Distribution Corporation’s gas distribution system and replacement of those joints that are determined to have unacceptable characteristics.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 2006-06-08

Adopted Date: 2006-05-31

Overall Date Closed: 2010-04-06

Synopsis: On August 21, 2004, about 8:54 a.m., a natural gas explosion destroyed a residence located at 48 Woodland Lane in DuBois, Pennsylvania. Two residents were killed in this accident. The Safety Board determined that the probable cause of the leak, explosion, and fire in DuBois, Pennsylvania, on August 21, 2004, was the fracture of a defective butt-fusion joint and the failure of National Fuel to have an adequate program to inspect butt-fusion joints and replace those joints not meeting its inspection criteria.

Probable Cause: The National Transportation Safety Board determines that the probable cause of the leak, explosion, and fire in DuBois, Pennsylvania, on August 21, 2004, was the fracture of a defective butt-fusion joint and the failure of the National Fuel Gas Distribution Corporation to have an adequate program to inspect butt-fusion joints and replace those joints not meeting its inspection criteria.

Ntsbnumber: DCA04MP006

Report Number: PAB-06-01

Addressee Name: Commonwealth of Pennsylvania, Public Utility Commission

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 2010-04-06

Addressee Acronym: PA PUC

Addressee Organization Type: S-State Government

Communication Date: 2009-12-03

Communication Type: Official Correspondence

Communication Contents: Letter Mail Controlled 1/7/2010 3:45:31 PM MC# 2100008 - From Paul J. Metro, Chief, Gas Safety Division: In 2006, Mr. Metro advised that PUC’s gas safety prosecutory staff (GSPS) and the National Fuel Gas Distribution Corporation (NFG) had developed a preliminary inspection protocol for butt-fusion joints; that the GSPS had directed the NFG to conduct a limited number of excavations in NFG’s service territory to identify butt joints; and, that during regular system operations, the NFG and the GSPS were to identify and inspect excavated butt-fusion joints, and visually unacceptable joints were to be replaced and retained for future analysis. Mr. Metro now advises that the PUC’s Gas Safety Division has established a long-term program to monitor the plastic fusion inspection statistics on a quarterly basis and is meeting with the NFG on a regular basis to review the collected data. The switch from monthly to quarterly data review will provide more field inspection time, and that as part of a legal settlement related to the DuBois, Pennsylvania incident, the NFG will be examining all plastic pipe fusion joints indefinitely. Further, given the miles of plastic pipe installed, it is expected that the plastic pipe fusion inspection program will continue at least for at least the next 30 years, and that the PUC Gas Safety Division will continue to monitor the results of the plastic fusion inspection program until the program is no longer required. The following summarizes the plastic pipe fusion inspection program: National Fuel construction crews document ALL fusions discovered during the course of normal business. Inspection forms and photographs or fusion samples are forwarded to the Engineering Services Department for analysis. Where visually questionable fusions are discovered Engineering recommends targeted excavations on the original project to evaluate the integrity of the pipe segment. Based on the targeted inspection results and the consequences of a future failure, engineering recommends one of the following remedial actions: Replacement of the pipe installed on the original project. Replacement of remaining known fusions Annual Leak Survey Status of targeted excavation and replacement projects are tracked and reported quarterly. Projects identified for replacement are leak surveyed quarterly until replacement is complete. Finally, the PUC records provided indicate that since inception of the inspection program, there have been no leaks detected. Because the plastic pipe fusion inspection program satisfies the recommendation, I recommend that Safety Recommendation P 06-1 be classified Closed Acceptable Action.

Addressee Acronym: PA PUC

Addressee Organization Type: S-State Government

Communication Date: 2006-10-27

Communication Type: Official Correspondence

Communication Contents: Letter Mail Controlled 11/13/2006 8:26:29 AM MC# 2060549 - From Paul J. Metro, Chief, Gas Safety Division: In July, the Gas Safety Prosecutory Staff and NFG developed a preliminary inspection-protocol for butt-fusion joints. First the Gas Safety Prosecutory Staff has directed NFG to conduct a limited number of excavations in NFG’s service territory to identify butt joints. Second, NFG and the Gas Safety Prosecutory Staff will also identify and inspect butt-fusion joints uncovered during regular system operations. In each part, visually unacceptable joints are replaced and retained for future analysis. The Gas Safety Prosecutory Staff and NFG are meeting at least monthly to monitor the progress of both aspects of the inspection protocol. Please contact me if you need additional information. The Gas Safety Prosecutory Staff will continue to investigate and monitor the butt-fusion joining problem and determine whether further action is necessary, which could include the filing of a formal complaint with the Commission if staff is unable to satisfactorily resolve the problem. Sincerely, Paul J. Metro, Supervisor, Gas Safety Division, Bureau of Transportation and Safety

Addressee Acronym: PA PUC

Addressee Organization Type: S-State Government

Communication Date: 2010-04-06

Communication Type: Official Correspondence

Communication Contents: In 2006, Mr. Metro advised the NTSB that the PUC’s gas safety prosecutory staff (GSPS) and the National Fuel Gas Distribution Corporation (NFG) had developed a preliminary inspection protocol for butt-fusion joints and that the GSPS had directed the NFG to conduct a limited number of excavations in NFG’s service territory to identify butt joints. Mr. Metro also indicated that, during regular system operations, the NFG and the GSPS were to identify and inspect excavated butt-fusion joints and visually unacceptable joints were to be replaced and retained for future analysis. The NTSB is pleased to learn that the PUC’s Gas Safety Division has established a long-term program to monitor the plastic fusion inspection statistics on a quarterly basis and is meeting with the NFG on a regular basis to review the collected data. The NTSB understands that the switch from monthly to quarterly data review will provide more field inspection time and that, as part of a legal settlement related to the DuBois, Pennsylvania, incident, the NFG will be examining all plastic pipe fusion joints indefinitely. Further, given the miles of plastic pipe installed, it is expected that the plastic pipe fusion inspection program will continue for at least the next 30 years and that the PUC Gas Safety Division will continue to monitor the results of the plastic fusion inspection program until the program is no longer required. The following summarizes the plastic pipe fusion inspection program: National Fuel construction crews document ALL fusions discovered during the course of normal business. Inspection forms and photographs or fusion samples are forwarded to the Engineering Services Department for analysis. Where visually questionable fusions are discovered, Engineering recommends targeted excavations on the original project to evaluate the integrity of the pipe segment. Based on the targeted inspection results and the consequences of a future failure, Engineering recommends one of the following remedial actions: Replacement of the pipe installed on the original project Replacement of remaining known fusions Annual Leak Survey Status of targeted excavation and replacement projects are tracked and reported quarterly. Projects identified for replacement are leak surveyed quarterly until replacement is complete. The NTSB is particularly pleased to note that, since the inspection program was initiated, there have been no leaks detected. Because the implementation of the plastic pipe fusion inspection program satisfies the recommendation, Safety Recommendation P 06-1 is classified CLOSED -- ACCEPTABLE ACTION.

Addressee Acronym: PA PUC

Addressee Organization Type: S-State Government

Communication Date: 2007-02-22

Communication Type: Official Correspondence

Communication Contents: The Safety Board notes that in July 2006, the PUC’s gas safety prosecutory staff (GSPS) and the National Fuel Gas Distribution Corporation (NFG) developed a preliminary inspection protocol for butt-fusion joints. In addition, the GSPS has directed the NFG to conduct a limited number of excavations in NFG’s service territory to identify butt joints. During regular system operations, the NFG and the GSPS will identify and inspect excavated butt-fusion joints, and visually unacceptable joints will be replaced and retained for future analysis. The Safety Board notes (1) that the GSPS and the NFG will meet at least monthly to monitor the progress of both aspects of the inspection protocol and (2) that the GSPS will continue to investigate and monitor the butt-fusion joining problem. Accordingly, Safety Recommendation P-06-1 is classified OPEN -- ACCEPTABLE RESPONSE pending completion of this effort. Thank you for your prompt action on this safety recommendation and continued commitment to pipeline safety. The Safety Board would appreciate receiving periodic updates on the status of this action and notification of the final results, including details of the NFG and associated construction standard analysis, and records of joints inspected and replaced.