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Safety Recommendation Details

Safety Recommendation P-17-001
Synopsis: On September 21, 2015, at 12:03 p.m., an employee of Bonefish Grill in Centreville, Virginia, called the Fairfax County 911 Center to report a gasoline odor.1 The Fairfax County Fire and Rescue Department (FCFRD) immediately dispatched units to the restaurant in the Centre Ridge Marketplace shopping center. (See figure 1.) After arriving at the scene, firefighters confirmed everyone had left the restaurant; they established an incident command center, and they began the investigation. They did not detect the presence of flammable vapor inside Bonefish Grill and ruled out a natural gas leak; however, they noted a gasoline odor coming from the storm drains at the shopping center. Firefighters detected the presence of flammable vapor in most of the storm drains behind Bonefish Grill and Chipotle. Flammable vapor in some storm drains in front of Bonefish Grill was as high as 100 percent of the lower explosive limit (LEL); however, no liquid was visible in the storm drains. After establishing that the gasoline did not come from the gas station that was located about 400 feet west of Bonefish Grill and that gasoline was not illegally dumped into a storm drain, firefighters considered that the odor could be coming from a leak in a nearby, buried Colonial Pipeline Company pipeline. Colonial confirmed the pipeline leak 2 days later.
Recommendation: TO THE PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION: Work with pipeline trade and standards organizations to modify the pipeline dent acceptance criteria to account for all the factors that lead to pipe failures caused by dents, and promulgate regulations to require the new criteria be incorporated into integrity management programs.
Original recommendation transmittal letter: PDF
Overall Status: Open - Acceptable Response
Mode: Pipeline
Location: Centreville, VA, United States
Is Reiterated: No
Is Hazmat: No
Accident #: DCA15MP002
Accident Reports: Pipeline Accident Brief: Colonial Pipeline Company Petroleum Product Leak, Centreville, Virginia
Report #: PAB-17-01
Accident Date: 9/21/2015
Issue Date: 6/15/2017
Date Closed:
Addressee(s) and Addressee Status: PHMSA (Open - Acceptable Response)

Safety Recommendation History
Date: 4/1/2019
Response: -From Howard R. Elliott, Administrator: Per PHMSA' s letter to the NTSB on September 29, 2017, PHMSA is working with the API Recommended Practice (RP) 1183 workgroup on the development of an RP for the assessment and management of dents/deformations in pipelines. Part of this effort will be to identify whether there are pipeline-specific factors that correlate to the occurrence of pipeline failures due to dents that are smaller than the PHMSA-mandated acceptance criteria. The RP 1183 workgroup kick-off meeting was held on April 18, 2018. Several meetings have been held since. PHMSA anticipates that the standard will be completed by Fall 2019. PHMSA notes that the NTSB emphasized that 49 CFR § 195.452 must be revised to satisfy the recommendation. PHMSA plans to assess the final standard before planning our next steps.

From: NTSB
Date: 2/21/2018
Response: We classified Safety Recommendation P-17-1 OPEN--ACCEPTABLE RESPONSE in our January 2, 2018, letter responding to your September 29, 2017, letter.

From: NTSB
Date: 1/2/2018
Response: We note that you plan to work with the standards organizations to identify pipeline-specific factors that correlate with pipeline failures for dent sizes less than the current PHMSA-mandated acceptance criteria, and that you will then identify revisions to assure that safety risks from dent related threats are appropriately mitigated. In our report on the accident in Centreville, Virginia, we found that the depth of the dent at the leak location was about 1.6 percent of the outer pipe diameter. Your pipeline regulations (Title 49 Code of Federal Regulations [CFR] 195.452, “Pipeline Integrity Management in High Consequence Areas”) do not require that dents having depths less than 6 percent of the pipeline diameter be repaired unless there is indication of metal loss, cracking, or a stress riser, or unless the dent affects pipe curvature at a girth weld or a longitudinal seam weld. We said that these requirements were similar to the relevant industry standard contained in American Society of Mechanical Engineers (ASME) standard B31.4, “Pipeline Transportation Systems for Liquid and Slurries.” We issued Safety Recommendation P 17-1 because neither section 195.452 of your regulations nor ASME B31.4 required the dent that caused the leak in Centreville to be repaired before it began leaking. We emphasize that, to satisfy this recommendation, 49 CFR 195.452 must be revised. Pending that revision, Safety Recommendation P 17-1 is classified OPEN--ACCEPTABLE RESPONSE.

Date: 11/13/2017
Response: -From Howard R. Elliott, Administrator: PHMSA sent NTSB a response to this recommendation on September 29, 2017. PHMSA looks forward to NTSB' s response.

Date: 9/29/2017
Response: -From Drue Pearce, Acting Administrator: I am writing to update you on the status of actions taken to-date by the Pipeline and Hazardous Materials Safety Administration (PHMSA) and our intended actions to address the recommendations following the National Transportation Safety Board's (NTSB) accident report, Colonial Pipeline Company Petroleum Product Leak, following the September 21, 2015, Centreville, Virginia, incident. The mission of PHMSA is to protect people and the environment by advancing the safe transportation of energy and other hazardous materials that are essential to our daily lives. PHMSA shares the NTSB's commitment to preventing accidents and saving lives. PHMSA has a long history of cooperating and collaborating with the NTSB, and we take seriously our responsibility to address all of the Board's recommendations. The NTSB accident report on the Centreville, Virginia, petroleum leak identified "the probable cause of the release [ ... ] was a through-wall corrosion fatigue crack that developed at a dent in the pipeline due to residual and operational stress and exposure to the underground environment." Colonial had previously examined the dent and did not find any cracks. Although this dent did not exceed the prescriptive repair criteria in 49 CFR Part 195, PHMSA's performance-based Integrity Management (IM) regulations supplement prescriptive safety requirements and set systemic performance requirements for operators. IM is based on practices employed by many safety-oriented organizations, whereby safety is continually improved through an iterative process of collecting data, identifying and prioritizing risks, undertaking corrective actions, and assessing performance. PHMSA requires operators to address risks to pipeline safety based on risk assessment of their own unique operating characteristics that extend beyond PHMSA's prescriptive minimum requirements. PHMSA notes that dent-related failures are relatively rare, with the majority of these spill volumes below 100 barrels and from a small number of pipeline systems. Since the Pipeline Safety Regulations ( 49 CFR Parts 192 and 195) already address risks to pipeline integrity, we believe that new regulations would not efficiently address this issue and that there are not enough dent-related incidents to justify a rulemaking. From 2001to2017, PHMSA's accident/incident reports show that dents were a contributing factor in, on average, only two hazardous liquid accidents and one gas transmission incident per year, out of an average of over 600 accidents/incidents total among all pipeline system types.1 The dent-related accident/incidents have been caused in most cases by poor pipeline construction techniques, operational or third party damage events, and improper past remediation associated with other pipeline-specific factors such as pipe materials, wall thickness, and diameter. Additionally, the majority of these hazardous liquid accidents are confined to a small number of operators' particular pipeline systems, so wider regulations may not be necessary for the majority of other pipeline systems. When an operator has a pipeline with a leak or rupture, whether caused by a dent or another pipeline-defect factor, PHMSA reviews the causes of the accident/incident and determines if an order is required to mandate that the operator conduct corrective actions to identify and mitigate integrity issues. Sometimes, these actions include additional pipeline system-specific inspections, different integrity assessment methods, procedural or process changes, training and any other needed remediation techniques to eliminate recurrence of a similar release. In summary, pipeline operators are required to know and understand the unique operating environments and inherent risks of each of their pipeline systems. PHMSA challenges operators to focus on performance and aim beyond the minimum compliance standards established through pipeline safety regulations, to ensure the safety of the public that lives and works around pipelines. Response: Concur. PHMSA agrees that working with industry and standards organizations to ensure that dent acceptance criteria accounts for all pipeline failure dent factors is an important step. Other dent factors include information such as steel properties, wall thickness, orientation, pipe diameter, and operating pressure and pressure cycles. PHMSA will work with the standards organizations to identify if there are pipeline-specific factors that correlate to the occurrence of pipeline failures for dent sizes less than the PHMSA-mandated acceptance criteria. Based on the information, we will identify next steps in assuring dents, and dent related threats are appropriately mitigated to assure safety. We anticipate completing this action by August 2019.

From: NTSB
Date: 3/15/2017
Response: On June 5, 2017, the National Transportation Safety Board (NTSB) adopted its report on the September 21, 2015, pipeline leak at a shopping center in Centreville, Virginia.1 The details of this accident and the resulting safety recommendations may be found in the investigative report, which can be accessed at under report number PAB-17/1. As a result of this investigation, the NTSB is issuing four new recommendations, including one to the Association of Oil Pipe Lines and the American Petroleum Institute, one to Colonial Pipeline Company, and the following two recommendations the Pipeline and Hazardous Materials Safety Administration: P-17-001 and P-17-002.