NTSB Safety Recommendation P-15-034

NTSB safety recommendation P-15-034.

TO CONSOLIDATED EDISON COMPANY OF NEW YORK, INC.: Revise your plastic pipe fusion welding procedure to require cleaning of the surfaces to be welded with suitable solvents to remove all dirt, water, oil, paint, and other contaminants as recommended in ASTM F2620, Standard Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 2015-06-29

Adopted Date: 2015-06-09

Overall Date Closed: 2020-01-28

Synopsis: On March 12, 2014, about 9:30 a.m. eastern daylight time, two adjacent multiuse five-story buildings were destroyed by a natural gas-fueled explosion and resulting fire. The buildings were situated on the west side of Park Avenue between East 116th Street and East117th Street in the East Harlem district of the Borough of Manhattan in New York City. The violent explosion damaged buildings on the east and west sides of Park Avenue and along East116th and East 117th Streets. The Metro-North Railroad suspended rail service for about 71/2 hours on the elevated railway along Park Avenue because of debris from the explosion on the track. Eight people died, more than 50 people were injured, and more than 100 families were displaced from their homes as a result of this accident. The cost to Consolidated Edison Company of New York, Inc. (ConEdison), of equipment damages, emergency response activities, remediation, and replacement exceeded $1.9 million.

Probable Cause: The National Transportation Safety Board determines that the probable cause of the accident was (1) the failure of the defective fusion joint at the service tee, installed by Consolidated Edison Company of New York, Inc., in 2011, that allowed natural gas to leak from the gas main and migrate into the building where it ignited and (2) a breach in the sewer line that went unrepaired by the New York City Department of Environmental Protection since at least 2006 that allowed groundwater and soil to flow into the sewer, resulting in a loss of support for the gas main, which caused the line to sag and overstressed the defective fusion joint.

Ntsbnumber: DCA14MP002

Report Number: PAR-15-01

Addressee Name: Consolidated Edison (Con Ed)

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 2020-01-28

Addressee Acronym: Con Ed

Addressee Organization Type: P-Private Industry

Communication Date: 2017-04-07

Communication Type: Official Correspondence

Communication Contents: On December 21, 2015, based on information provided in your September 25, 2015, letter, Safety Recommendations P-15-34 and -37 were classified OPEN--ACCEPTABLE RESPONSE. To date, we have not received any further updates regarding your actions to address these recommendations.

Addressee Acronym: Con Ed

Addressee Organization Type: P-Private Industry

Communication Date: 2017-12-01

Communication Type: Official Correspondence

Communication Contents: We note that your plastic fusion welding procedure (as documented in your specification G-8123 Rev. 17, effective 12/3/15) was updated to require PE pipe/tubing to be cleaned with alcohol wipes for all heat fusions, regardless of whether any contaminant is visible on the fusion surfaces, prior to the pipe being placed in the fusion machine. This specification complies with ASTM standard F2620. We also note that you are sponsoring a project with the Gas Technology Institute (GTI) to evaluate solvent cleaning and PE joining procedures. The goals of this project, which you expect to finish shortly, are to gain knowledge about the use of liquid cleaning solvents and to develop solvent cleaning and surface preparation best practices. You plan to evaluate and implement the guidelines during 2018, after the GTI project concludes. Please inform us when the GTI study is completed and you have incorporated the resulting best practices and standards into the procedures and specifications you use for heat fusion joining of PE pipe and fittings. Pending those actions, Safety Recommendation P-15-34 remains classified OPEN--ACCEPTABLE RESPONSE.

Addressee Acronym: Con Ed

Addressee Organization Type: P-Private Industry

Communication Date: 2020-01-28

Communication Type: Official Correspondence

Communication Contents: You previously told us that, in response to this recommendation, you updated your plastic fusion welding procedure (as documented in your specification G-8123 Rev. 17, effective December 3, 2015) to require PE pipes and tubing to be cleaned with alcohol wipes for all heat fusions, regardless of whether any contaminant is visible on the fusion surfaces, prior to the pipe being placed in the fusion machine. This specification complies with ASTM standard F2620. You also told us that you were sponsoring a project with the Gas Technology Institute (GTI) to evaluate solvent cleaning and PE joining procedures. We note that the GTI study, Solvent Cleaning and PE Joining Procedures, was published on June 27, 2019. We further note that you reviewed the study’s results, and concluded that no additional change to your heat fusion procedure is required. The update that you made to specification G-8123 Rev. 17 satisfies Safety Recommendation P-15-34. Further, we commend your proactive sponsorship of the GTI study. Consequently, Safety Recommendation P-15-34 is classified CLOSED--ACCEPTABLE ACTION.

Addressee Acronym: Con Ed

Addressee Organization Type: P-Private Industry

Communication Date: 2015-12-21

Communication Type: Official Correspondence

Communication Contents: We understand that you will amend your plastic fusion procedures to comply with ASTM F2620, Standard Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings, and that you are sponsoring a study by the Gas Technology Institute to evaluate solvent cleaning and polyethylene joining procedures, which you expect will be completed within 18 months. We note that your goal is to gain knowledge of the issues related to the use of liquid cleaning solvents, to develop a data driven consensus on solvent cleaning best practices, and to optimize the surface preparation process for plastic fusion. We further note that, upon completion of the study, you will adopt the resultant applicable guidelines and best practices. When completed, the actions you described will satisfy Safety Recommendation P-15-34; accordingly, it is classified OPEN—ACCEPTABLE RESPONSE pending your adoption of the guidelines and best practices. Please send us a copy of your revised fusion procedures once they become available.

Addressee Acronym: Con Ed

Addressee Organization Type: P-Private Industry

Communication Date: 2017-05-01

Communication Type: Official Correspondence

Communication Contents: Marc E. Huestis, Senior Vice President: The plastic fusion welding procedure {G-8123 Rev. 17, effective 12/3/15) was updated to require the cleaning of PE pipe/tubing with alcohol wipes for all heat fusions, regardless of whether any contaminant is visible on the fusion surfaces, prior to the pipe being placed in the fusion machine. Please reference the attached Gas Specification G-8123-17, entitled, "Heat Fusion Joining of Polyethylene {PE} Plastic Pipe/Tubing and Fittings for Gas Mains and Services for further clarification. Also, Con Edison is sponsoring a project with the Gas Technology Institute that is evaluating solvent cleaning and polyethylene joining procedures. The project's goals are to gain knowledge of the issues related to the use of liquid cleaning solvents, to develop a data driven consensus on solvent cleaning best practices and to optimize the surface preparation process. Once the project is concluded, we will evaluate and implement the guidelines that are improvements to Con Edison's current preparation process for plastic fusion. We anticipate this project will conclude by the end of 2017, which would allow for evaluation and potential implementation of any proposed process changes in 2018.

Addressee Acronym: Con Ed

Addressee Organization Type: P-Private Industry

Communication Date: 2019-10-09

Communication Type: Official Correspondence

Communication Contents: -From Marc Huestis, Senior Vice President, Gas Operations: In Con Edison's initial response to this recommendation, it reported that it updated its plastic fusion welding procedure (G-8123 Rev. 17, effective 12/3/15) to require the cleaning of PE pipe/tubing with alcohol wipes for all heat fusions, regardless of whether any contaminant is visible on the fusion surfaces, prior to the pipe being placed in the fusion machine. Also, the Company reported that it was sponsoring a project with the Gas Technology Institute (GTI) to evaluate solvent cleaning and polyethylene joining procedures. The project's goals were to gain knowledge of the issues related to the use of liquid cleaning solvents, to develop a data driven consensus on solvent cleaning best practices and to optimize the surface preparation process. The NTSB noted both of these items in its response. The NTSB's response also requested that Con Edison inform the NTSB when the GTI study is completed and Con Edison has incorporated the resulting best practices and standards into the Company's procedures and specifications for heat fusion joining of PE pipe and fittings. Pending these actions, the NTSB classified Safety Recommendation P-15-34 as "OPEN--ACCEPTABLE RESPONSE." The GTI Study titled Solvent Cleaning and PE Joining Procedures was published on June 27, 2019. After analyzing the study's results, no additional changes are required of Con Edison's heat fusion procedure. As previously submitted, Con Edison updated its specification G-8123 Rev. 17, effective 12/3/15, as described above. Therefore, we request this recommendation's status be updated to "CLOSED - ACCEPTABLE ACTION." A summary of the GTI study can be found here: http://www.otdco.org/repo rts/Documents/516a-OTD-18-0001-Solvent-Cleaning-and-PE-Pipe-Joini ngSummaryReport May2018.pdf If you have any questions, please contact me.

Addressee Acronym: Con Ed

Addressee Organization Type: P-Private Industry

Communication Date: 2019-10-09

Communication Type: Official Correspondence

Communication Contents: -From Marc Huestis, Senior Vice President, Gas Operations: This letter provides Consolidated Edison of New York, lnc.'s (Con Edison or the Company) update to its response to the National Transportation Safety Board (NTSB) recommendation P-15-34 issued to Con Edison after the March 12, 2014 incident in East Harlem. The Company notes the NTSB accepted Con Edison's responses to NTSB recommendations P-15-35 through P-15-37 and the status of these three recommendations is "CLOSED - ACCEPTABLE ACTION." NTSB Recommendation P-15-34 states: Revise your plastic pipe fusion welding procedure to require cleaning of the surfaces to be welded with suitable solvents to remove all dirt, water, oil, paint, and other contaminants as recommended in ASTM F2620, Standard Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings. In Con Edison's initial response to this recommendation, it reported that it updated its plastic fusion welding procedure (G-8123 Rev. 17, effective 12/3/15) to require the cleaning of PE pipe/ tubing with alcohol wipes for all heat fusions, regardless of whether any contaminant is visible on the fusion surfaces, prior to the pipe being placed in the fusion machine. Also, the Company reported that it was sponsoring a project with the Gas Technology Institute (GTI) to evaluate solvent cleaning and polyethylene joining procedures. The project's goals were to gain knowledge of the issues related to the use of liquid cleaning solvents, to develop a data driven consensus on solvent cleaning best practices and to optimize the surface preparation process. The NTSB noted both of these items in its response. The NTSB's response also requested that Con Edison inform the NTSB when the GTI study is completed and Con Edison has incorporated the resulting best practices and standards into the Company's procedures and specifications for heat fusion joining of PE pipe and fittings. Pending these actions, the NTSB classified Safety Recommendation P-15-34 as "OPEN--ACCEPTABLE RESPONSE." The GTI Study titled Solvent Cleaning and PE Joining Procedures was published on June 27, 2019. After analyzing the study's results, no additional changes are required of Con Edison's heat fusion procedure. As previously submitted, Con Edison updated its specification G-8123 Rev. 17, effective 12/3/15, as described above. Therefore, we request this recommendation's status be updated to "CLOSED - ACCEPTABLE ACTION." A summary of the GTI study can be found here: http://www.otdco.org/reports/Documents/516a-OTD-18-0001-Solvent-Cleaning-and-PE-Pipe-JoiningSummaryReportMay2018.pdf If you have any questions, please contact me.

Addressee Acronym: Con Ed

Addressee Organization Type: P-Private Industry

Communication Date: 2015-09-25

Communication Type: Official Correspondence

Communication Contents: -From Craig S. Ivey, President: Con Edison's heat fusion joining procedure was qualified in accordance with PPI TR-33 and our pipe manufacturers' (JM Eagle and Performance Pipe) plastic fusion procedures. In general, the natural gas industry promotes the use of a dry, lint-free non-synthetic cloth to clean polyethylene (PE) plastic pipe prior to heat fusion (butt, sidewall, and branch). Consistent with ASTM F2620, Standard Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings, Performance Pipe recently amended its fusion procedure PP750 to require the use of 90% or greater isopropyl alcohol (alcohol) to clean extremely dirty pipe, with the additional requirement that alcohol be applied before facing, but never after facing. Given that ASTM F2620 cites alcohol as the preferred method to clean extremely dirty pipe, Con Edison will amend its plastic fusion procedures to require the use of alcohol for all methods of heat fusion, regardless of whether any contaminant is visible on the fusion surfaces. For butt fusion we will only permit the use of alcohol before facing. This procedural change exceeds the current ASTM standard and eliminates operator discretion with respect to determining whether the pipe surfaces are visibly contaminated. Con Edison will amend its plastic fusion procedure (G-8123-16, Heat Fusion Joining of Polyethylene Plastic Pipe/Tubing and Fittings for Gas Mains and Services) to reflect this change and submit the amended procedure to the New York State Department of Public Service (NYSDPS) Staff for its 30-day review period. To drive standardization in the industry, the Company will sponsor an Operations Technology Development Study by the Gas Technology Institute, (a leading gas research, development and training organization), to evaluate Solvent Cleaning and Polyethylene Joining Procedures. The goal of the study is to gain knowledge of the issues related to the use of liquid cleaning solvents, develop a data driven consensus on solvent cleaning best practices, and to optimize the surface preparation process for plastic fusion. The study is anticipated to take approximately 18 months. Con Edison will adopt the applicable guidelines and best practices which result from the study.