Key Takeaways
- PHMSA proposes replacing rigid, prescriptive repair timelines with risk-informed, engineering-based response criteria.
- The rule would establish a simplified three-tier response framework: immediate, near-term and other conditions.
- PHMSA estimates annual cost savings of approximately $390 million for the pipeline industry.
- Comments are due Sept. 8, 2026.
On July 8, 2026, the Pipeline and Hazardous Materials Safety Administration (PHMSA) published a notice of proposed rulemaking that would substantially modernize anomaly response criteria for gas transmission and hazardous liquid pipelines. The proposed rule would replace prescriptive but rigid repair timelines that have been in place since the early 2000s with engineering-based, risk-informed response criteria that leverage the dramatic advances in inline inspection (ILI) technology over the past two decades.
PHMSA has high hopes for its proposed rule. According to Administrator Paul Roberti, the agency is “modernizing [its] safety regulations to match this new landscape” and that “[p]rioritizing repairs to target actual threats — rather than sticking to prescriptive, one-size-fits-all timelines — will improve safety and unleash American energy.” If finalized, PHMSA expects the rule to save the pipeline industry approximately $390 million annually while simultaneously improving pipeline safety. Comments on the proposed rule are due Sept. 8, 2026.
Background
Congress calls on the U.S. Department of Transportation (DOT) to set minimum safety standards for the transportation of gas and hazardous liquids by pipeline. Acting through PHMSA, DOT promulgated integrity management (IM) program regulations for hazardous liquid pipelines in 2000 and for gas transmission pipelines in 2003, pursuant to congressional mandates in the Pipeline Safety Improvement Act of 2002 and related legislation. These IM programs require pipeline operators to assess the condition of their pipelines and respond to anomalies discovered through those assessments.
When the original IM regulations were adopted, the response criteria relied on generic depth-based measurements that do not account for the specific characteristics of a given anomaly or the operating parameters of the pipeline. In the decades since, ILI technology advanced dramatically. Modern ILI tools can detect and characterize a wider range of anomalies — including cracks, dents and various forms of corrosion — with far greater precision than was possible when the original response criteria were established. Generic measurements are thus rigid in the wake of two decades of technological advancements.
In 2022, PHMSA took a first step toward modernization by amending the gas transmission pipeline response criteria to incorporate engineering-based concepts through the Safety of Gas Transmission Pipelines Rule. But in 2024, the U.S. Court of Appeals for the D.C. Circuit vacated portions of that rule in Interstate Natural Gas Association of America v. PHMSA (INGAA), finding that PHMSA had not adequately justified its selection of a 1.25 failure pressure ratio (FPR) threshold for crack-like anomalies as an immediate response criterion. In May 2025, PHMSA issued an advance notice of proposed rulemaking soliciting public input on modernizing repair criteria for gas and hazardous liquid pipelines. Commenters overwhelmingly favored modernizing the response criteria to reflect current engineering knowledge and ILI capabilities.
Proposed Unified Three-Tiered Response Schedule
The proposed rule would establish a simplified, three-tiered response schedule for anomalies discovered through integrity assessments. Currently, hazardous liquid operators face a complex set of response deadlines — immediate, 60-day, 180-day and other conditions — while gas transmission operators work under immediate, scheduled, monitored and other categories. PHMSA’s modernized rule would replace these regimes with a unified framework consisting of three tiers: (1) immediate response conditions, (2) near-term response conditions and (3) other conditions.
Under the proposed framework, “immediate” conditions require remediation immediately upon discovery. “Near-term” conditions must be addressed within one year in high-consequence areas and within two years for gas transmission pipelines, or within one year for hazardous liquid pipelines regardless of location. “Other” conditions must be addressed prior to the next scheduled reassessment or monitored using appropriate methods. This consolidation is intended to reduce complexity, align the two regulatory programs and focus operator resources on the anomalies that pose the greatest risk to pipeline integrity.
Key Proposed Changes for Gas Transmission Pipelines
For gas transmission pipelines, the proposed rule would amend 49 C.F.R. § 192.714 to refine several immediate response criteria. Most significantly, in what appears to be a response to the D.C. Circuit’s INGAA decision, PHMSA proposes to add an immediate response criterion for cracks and crack-like anomalies with an FPR of 1.1 or below. By selecting a threshold of 1.1 FPR — supported by additional technical analysis — PHMSA aims to satisfy the court’s requirement for a reasoned explanation while still capturing the highest-risk crack conditions.
The proposed rule would also raise the immediate response threshold for crack depth from 50% of the pipe wall thickness to 70%, reflecting engineering analysis showing that shallower cracks in many pipeline configurations do not pose an imminent threat. Additionally, PHMSA proposes to revise the immediate response criterion for preferential seam corrosion from 1.25 FPR to 1.1 FPR, and to refine the interacting dent criterion to include dents interacting with gouging but to exclude non-mechanical metal loss of up to 10% of wall thickness.
Proposed Response Criteria for Hazardous Liquid Pipelines
The existing hazardous liquid response criteria have remained largely unchanged since the early 2000s and rely heavily on generic depth-based thresholds that do not reflect modern engineering capabilities. PHMSA’s proposed new criteria do.
Under the proposed criteria, metal loss anomalies with an FPR of 1.1 or below would require immediate response, while those with an FPR of 1.39 or below would trigger near-term response. For cracks, an FPR of 1.1 or below — or depth exceeding 70% of wall thickness — would require immediate response; an FPR of 1.39 or below — or depth exceeding 50% — would trigger a near-term response. For dents, any dent with interacting mechanical damage would require immediate response regardless of orientation, and the existing 180-day response conditions would become near-term conditions. The rule would eliminate the existing 60-day and 180-day timelines, consolidating near-term response to a single one-year deadline.
Estimated Cost Savings
PHMSA estimates that the proposed rule, if finalized, would generate approximately $390 million in annual cost savings for the pipeline industry. For gas transmission pipelines, the estimated savings range from $214.6 to $241.7 million annually. For hazardous liquid and carbon dioxide pipelines, savings are estimated at $148.5 million annually. These savings derive primarily from the ability to prioritize repairs based on actual risk — allowing operators to defer or reclassify anomalies that prescriptive criteria would currently require them to address on expedited timelines. PHMSA has designated the proposed rule as both an economically significant regulatory action under Executive Order 12866 and a deregulatory action.
McGuireWoods continues to monitor developments in the area. For questions concerning this alert, contact the authors or a member of the Environmental Enforcement & Regulatory Counseling Practice Group.