A notice of proposed rulemaking (NPRM)1 issued by the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) (Washington, DC) outlines significant changes to the Pipeline Safety Regulations that are intended to increase the safety of onshore natural gas transmission and gathering pipelines across the country. The proposed rule, “Pipeline Safety: Safety of Gas Transmission and Gathering Pipelines” (RIN 2137-AE71), would broaden the scope of safety coverage by adding new assessment and repair criteria for gas transmission pipelines, and by expanding these protocols to include pipelines located in areas of medium population density—moderate consequence areas (MCAs)—where an incident would pose risk to human life.
“The significant growth in the nation's production, usage, and commercialization of natural gas is placing unprecedented demands on the nation's pipeline system,” said former U.S. Transportation Secretary Anthony Foxx. “This proposal includes a number of commonsense measures that will better ensure the safety of communities living alongside pipeline infrastructure and protect our environment.”
According to PHMSA, the proposed regulations address four congressional mandates from the Pipeline Safety, Regulatory Certainty, and Job Creation Act of 2011; one recommendation from the U.S. Government Accountability Office (GAO); and six National Transportation Safety Board (NTSB) (Washington, DC) recommendations, including the recommendation that pipelines built before 1970 be tested, which was adopted in the wake of the San Bruno, California explosion. Currently, these older pipelines are exempt from certain pipeline safety regulations because they were constructed and placed into operation before pipeline safety regulations were developed. In its investigation of Pacific Gas & Electric’s natural gas pipeline failure and explosion on September 9, 2010, in San Bruno, the NTSB concluded that hydrostatic testing of grandfathered pipelines would likely have exposed the defective pipe that led to the pipeline failure.
“Following significant pipeline incidents such as the 2010 San Bruno, California tragedy, there was a pressing need to enhance public safety and the integrity of the nation's pipeline system,” said former PHMSA Administrator Marie Therese Dominguez. “The proposal's components address the emerging needs of America's natural gas pipeline system and adapt and expand risk-based safety practices to pipelines located in areas where incidents could have serious consequences.”
Changes to IM, non-IM Requirements
PHMSA proposes changes to the integrity management (IM) requirements as well as changes to address issues related to non-IM requirements. This NPRM also proposes modifying the regulation of onshore gas gathering lines. In the notice, PHMSA states that current regulatory requirements applicable to gas pipeline systems have increased the level of safety associated with the transportation of gas. Still, incidents with various causes and significant consequences continue to occur on gas pipeline systems. PHMSA also has identified concerns during inspections of gas pipeline operator programs that indicate a potential need to clarify and enhance some requirements. Based on this experience, this NPRM proposes additional safety measures to increase the level of safety for those pipelines that are not in high consequence areas (HCAs), as well as clarifications and selected enhancements to IM requirements to improve safety in HCAs.
The proposed rule addresses several IM topics that include, among other things, revising IM repair criteria for pipeline segments in HCAs to address cracking defects, non-immediate corrosion metal loss anomalies, and other defects; adding requirements for monitoring gas quality and mitigating internal corrosion; adding requirements for external corrosion management programs including aboveground surveys, close interval surveys, and electrical interference surveys; and explicitly including requirements for management of change currently invoked by compliance to industry standards.
With respect to non-IM requirements, the NPRM adds requirements for monitoring gas quality and mitigating internal corrosion; adds requirements for external corrosion management programs including aboveground surveys, close interval surveys, and electrical interference surveys; adds additional requirements for management of change; establishes repair criteria for pipeline segments located in areas not in an HCA; and adds requirements for verification of maximum allowable operating pressure (MAOP) in accordance with new Code of Federal Regulations (CFR) section §192.624, and for verification of pipeline material in accordance with new CFR section §192.607 for certain onshore, steel, gas transmission pipelines. Requirements that would apply to previously unregulated pipelines meeting these criteria would be limited to damage prevention, corrosion control (for metallic pipe), a public education program, MAOP limits, line markers, and emergency planning.
Proposed Rules for New Topics
This NPRM also proposes requirements for additional topics that have arisen since issuance of the Advance Notice of Proposed Rulemaking (ANPRM). Among these are adding regulations to require safety features on launchers and receivers for inline inspection, scraper, and sphere facilities, and incorporating consensus standards into the regulations for assessing the physical condition of in-service pipelines using inline inspection, internal corrosion direct assessment, and stress corrosion cracking direct assessment. The overall goal of this proposed rule is to increase the level of safety associated with the transportation of gas by proposing requirements to address the causes of recent incidents with significant consequences, clarify and enhance some existing requirements, and address certain statutory mandates of the Act and NTSB recommendations.
Daniel Thayer, team leader of integrity management with engineering, surveying, and construction firm Shafer, Kline & Warren (Lenexa, Kansas), explains that understanding the forthcoming changes and how to address them proactively should be an essential part of operations and maintenance plans moving forward. One of the most significant areas of change that will have far-reaching impacts on owners and operators focuses on MAOP and pipeline material verification.
When approaching MAOP validation, Thayer breaks it into a two-part process. The first step is materials validation as part of 49 CFR Part 192.2 For this, a design formula is used that accounts for the pipeline’s specified minimum yield strength (SMYS), wall thickness, and diameter multiplied by the class location factor, which is based on population density and the number of residents living within close proximity of the pipeline. Operators need to verify their records are traceable, verifiable, and complete. For the second step, hydrostatic testing or other approved methods must be used to validate the lengths of pipe that have missing information.
“During the first step we go through the records to identify gaps, and show that the parameters used in the design formula were accurate and support the pipeline’s current MAOP,” says Thayer. “The second step is really about proving the pipe through a PHMSA-approved method, the most common of which is hydrostatic testing.”
Currently, pipelines that were installed before 1970 can rely upon a grandfather clause that allows operation of the pipeline at the highest pressure in the five years prior to 1970 without hydrostatic test records. In the NPRM, it is recommended that the grandfather clause be eliminated. According to PHMSA, about 60% of natural gas transmission pipeline mileage was installed prior to 1970.
“The operating pressures that these pipelines are operating at under the grandfather clause may not have ever been substantiated,” says Thayer. “If that clause disappears, as PHMSA is recommending, it will affect a large number of owners and operators who are going to need to prove these pipelines through hydrostatic testing or other methods approved by PHMSA.”
Other Recommended Changes
Another change recommended is the definition of MCAs. Pipelines in the newly defined MCAs would be required to have complete integrity assessments in addition to those for HCAs, which are currently subject to comprehensive IM regulations, and are defined as pipeline segments with 20 or more buildings intended for occupancy within the impact radius of the pipeline (which is calculated based on the pipeline’s diameter and MAOP). MCAs would be calculated using the same formula except the threshold would be five buildings rather than 20.
According to the NPRM, the intention is that any pipeline location where people are normally expected to be located would be afforded extra safety protections. This would include periodic integrity assessment; reliable, traceable, verifiable, and complete materials documentation; and MAOP verification.
“We always begin the process with a comprehensive review of construction job books to verify that they have the documentation to substantiate the pressure at which the pipeline is operating,” says Thayer. “We then perform a gap analysis to determine what documents are missing, and come up with a strategic plan to bring the pipelines into compliance, prioritized based on risk level.”
The final two areas of regulatory expansion related to MAOP are the recommended addition of a spike test as part of the hydrostatic testing requirement and the application of transmission line MAOP regulations to certain gathering lines.
“The impacts of these regulations are far reaching, and, if enacted, may tax the capabilities of the integrity management industry as we work to meet the needs of pipeline operators,” says Thayer. “There will likely be a cost to waiting. As the demand for hydrotests and records validation increases, so may the cost of these services. By taking a proactive approach to these proposed changes, operators will avoid these market pressures while protecting themselves against regulatory enforcement as well as dangerous, costly pipeline incidents.”
The complete NPRM can be viewed in the Federal Register.1
Sources: Pipeline and Hazardous Materials Safety Administration, phmsa.dot.gov; and Shafer, Kline & Warren, skw-inc.com.
References
1 Department of Transportation, Pipeline and Hazardous Materials Safety Administration, “Pipeline Safety: Safety of Gas Transmission and Gathering Pipelines; Proposed Rule,” Federal Register 81, 68 (2016): pp. 20722-20856.
2 U.S. Code of Federal Regulations (CFR) Title 49, Part 192, “Transportation of Natural and Other Gas by Pipeline: Minimum Federal Safety Standards” (Washington, DC: Office of Federal Register, 2016).