PHMSA’s New Rule for Gas Transmission Lines


(By Brianne Kurdock and Keith Coyle)

On August 24, 2022, the Pipeline and Hazardous Materials Safety Administration (PHMSA) published a new final rule for onshore gas transmission pipelines (the Rule).  The Rule marks the completion of a three-phase rulemaking process, commonly referred to as the Gas Mega Rule, that began more than a decade ago.  The Rule focuses mainly on transmission pipelines and amends or adds various provisions to 49 C.F.R. Part 192.  The Rule will become effective on May 24, 2023.  There are six key areas that owners and operators of gas transmission pipelines should be aware of:

Definitions and Standards Incorporated by Reference

PHMSA added new definitions for terms referenced in the regulations, including close interval survey, distribution center, dry gas or dry natural gas, hard spot, in-line inspection (ILI), in-line inspection tool or instrumented internal inspection device, and wrinkle bend. The definition of transmission pipelines was revised to include a “connected series” of pipelines to clarify that transmission pipeline can be downstream of other transmission pipelines, and to allow operators to voluntarily designate their pipelines as transmission lines.

Management of Change

Operators of all onshore gas transmission pipelines must now evaluate and mitigate any significant changes that pose a risk to safety or the environment through a management of change process.  The process must include the reasons for the change, the authority for approving changes, an analysis of the implications, the acquisition of required work permits, and evidence documenting communication of the change to affected parties, time limitations, and the qualification of staff.    For pipeline segments not covered by Subpart O, operators must implement this management of change process by February 26, 2024. Operators may seek a technically justified extension of this deadline of up to one year through the section 192.18 notification process.  PHMSA specifically noted that these changes do not apply retroactively and do not cover gathering or distribution pipelines.

Corrosion Control and Related Construction Requirements

The Rule amends numerous corrosion control requirements for onshore gas transmission pipelines, addressing the monitoring and remediation, if needed, of both external and internal corrosion.  The Agency issued new requirements to conduct pipe coating assessments soon after construction, determine protective coating strength, survey for interference currents, and monitor gas streams for internal corrosivity. In conjunction with the enhanced corrosion monitoring for internal and external corrosion, PHMSA established new corrosion control remediation criteria and timelines to correct discovered deficiencies. PHMSA acknowledged that these new construction and corrosion control requirements do not apply to gathering or distribution pipelines.

Inspections and Remedial Action Following Extreme Weather Events

Similar to the requirements for hazardous liquid pipeline operators, PHMSA is now requiring gas operators to perform an initial inspection following extreme weather events such as earthquakes, river channel migration, and landslides.  The operator must conduct the inspection 72 hours after it reasonably determines that the affected area can be safely accessed by personnel and equipment and the equipment and personnel are available.  The operator must take prompt remedial action to ensure the safe operation of a pipeline based on the information obtained from the inspection.  PHMSA explains that such remedial actions may include reducing the operating pressure, shutting down the pipeline, modifying, repairing, or replacing any damaged pipeline facilities, or performing additional patrols, surveys, tests, or inspections.

Integrity Management 

A significant portion of the Rule focuses on the integrity management (IM) program requirements in 49 C.F.R. 192 Subpart O.  The Rule prescribes new or amended requirements for identifying and analyzing threats, performing direct assessments, repairing pipelines, and implementing preventive and mitigative measures (P&MM).

Threat Identification and Data Integration

PHMSA has added certain pipeline attributes from ASME/ANSI B31.8S directly into the pipeline safety regulations.  Current IM regulations require operators to conduct a risk assessment using the identified threats to determine what additional P&MM are needed to ensure the safe operation of the pipeline.  Operators must begin to integrate all pertinent data elements starting on May 24, 2023, with all available attributes integrated by February 26, 2024. An operator may request an extension of up to one year by submitting a notification to PHMSA at least 90 days before February 26, 2024, in accordance with § 192.18.

Internal Corrosion Direct Assessment and Stress Corrosion Cracking Direct Assessment

The rule addresses direct assessments by incorporating NACE SP0204-2008 and NACE SP0206-2006 by reference.  These standards concern stress corrosion cracking direct assessment and internal corrosion direct assessment, respectively.

Repair Criteria

Finally, the Rule provides a robust overhaul of current repair criteria regulations.  The Rule applies integrity-related repair criteria to pipelines not subject to the integrity management requirements in Subpart O.  Repair criteria for immediate conditions, which include certain crack, dent, and corrosion anomalies, are now identical to those in Subpart O.  Operators of non-Subpart O pipelines have two years to repair “one-year conditions,” which vary slightly from those in Subpart O, and must monitor certain conditions.  The Rule requires operators to use these repair criteria when making permanent repairs on transmission lines located outside of HCAs.

Other Considerations

On September 23, 2022, the Interstate Natural Gas Association of America, the American Petroleum Institute, and the American Gas Association submitted petitions for reconsideration on this rule.

If you have any questions about PHMSA’s new final rule, contact Brianne Kurdock at 202-853-3462 or or Keith Coyle at 202-853-3460 or

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Reprinted with permission from the October 2022 issue of The PIOGA Press. All rights reserved.