Colorado PUC's Notice of Proposed Rulemaking
The following applies to pipelines subject to the jurisdiction of the Colorado Public Utilities Commission (COPUC).
The COPUC issued a Notice of Proposed Rulemaking (NOPR) on July 1st to require operators to conduct more frequent leak surveys using Advanced Leak Detection Technologies (ALDT) and to address identified leaks in a timely manner.
The COPUC had previously indicated it would be premature to release rules and definitions regarding ALDT while PHMSA was undertaking a similar rulemaking process. However, PHMSA’s process has not resulted in final, updated, and published rules. Colorado House Bill 25-1280 requires COPUC to adopt rules regarding pipeline repair and the use of ADLT on or before November 1, 2025. Given the uncertainty with the current PHMSA process and the state mandated timeline, the COPUC is proposing these new rules now.
PHMSA’s rulemaking process highlighted that federal standards for leak detection have been unchanged since the 1970s despite improvements in technology and operator practices, leading to leaks being undetected and potentially developing into incidents. Existing federal standards only required the repair of leaks if they presented a hazard to people or property and for most of those leaks there were no repair timeframes. Environmental risks from gas pipeline leaks were largely unaddressed.
The proposed rules from the COPUC continue to prioritize public safety while also acknowledging state law that recognizes improved environmental protection through advanced leak detection and repair. The proposed rules also place new importance on establishing criteria surrounding leak classification, leak survey intervals, repair timelines, and accountability for meeting criteria.
Environmental protection through leak detection and repair is also consistent with multiple pieces of state legislation that call for a reduction in greenhouse gas (GHG) emissions. COPUC acknowledges that utility emission reduction requirements are separate from gas pipeline safety requirements. The new proposed rules do not have emission reduction requirements or targets but were still considered within the broader context of the state legislation encouraging environmental protection and limiting GHG emissions.
Rule Updates
General – Updates were made to grammar/spelling, as well as to definitions and federal standards incorporated by reference.
More Stringent Standards – Proposed updates clarify when the COPUC has a more stringent rule than federal standards the COPUC rule applies.
Submission of Reports and Notices – Minor updates to reflect how Geographic Information Systems must be filed, as well as some additional data requirements such as wall thickness and identification of class location.
Additionally, more information regarding leak surveys and evaluation is now required for annual leak reports.
Submission of Annual Reports – As part of the annual reporting process, by March 31 of each year, operators must submit a list of leak detection tools, techniques, methods, and processes including any ADLT being used and the extent of their use.
Pipeline Excavation Damage Prevention – The proposed updates delete exemptions from rules that were granted to gathering systems within the regulatory jurisdiction of the COPUC.
Small Operator Systems – Language update from “hazardous” to “an existing or probably hazard to persons or property” to provide consistency with the language in the new rules. This update is not expected to have a substantive effect on small operator’s leak classification or repair protocols.
Advanced Leak Detection Survey Requirements – New language requiring periodic leak surveys using ALDT and imposing different leak survey intervals on transmission, distribution, and gathering pipelines.
Operators have the flexibility to choose any ALDT for a leak survey, but must consider in their selection:
Commercially available leak detection technologies and practices.
The ability of specific ALDTs to estimate the leak rate.
The size and configuration of the pipeline system.
The system’s operating parameters and environment.
Leak survey intervals:
Transmission pipelines in Cass 1, 2, 3, or an HCA must perform leak detection surveys at least 2x/year not to exceed 7.5 months.
Transmission pipelines in Class 4 areas must perform leak detection surveys at least 4x/year, not to exceed 4.5 months.
Distribution pipelines inside business districts follow 49 CFR 192.723.
Distribution pipelines outside of business districts, but with higher risk factors require leak detection surveys annually, not to exceed 15 months. Note: This provision is to provide flexibility in case of adverse environmental conditions. COPUC is seeking comment on whether this flexibility is necessary or whether it should be applicable to other types of pipelines as well.
Other distribution pipelines outside of business districts require leak detection surveys once every 3 years, not to exceed 39 months.
Small Operator Systems are exempt from this section.
Gathering pipelines in Class 1, 2, and 3 areas require leak detection surveys at least 2x/year, not to exceed 7.5 months.
Gathering pipelines in Class 4 areas require leak detection surveys 4x/year, not to exceed 4.5 months.
Leak Classification and Repair Requirements – The proposed rules require the classification of discovered leaks and sets timeframes for operators to address the through repair, replacement, abandonment, or in limited circumstances, periodic monitoring. This portion of the proposed rules has an effective date of January 1, 2027, to allow operators time to bring their leak classification and response processes into compliance.
The proposed rules require each operator to inspect and classify reports of gas leaks within two hours of confirmed discovery and operators must estimate the leakage rate of a gas leak within 48 hours to confirm the initial classification. The 48-hour timeframe after discovery allows focus on leak repair and should rely on information operators would reasonably know within hours of leak discovery.
Leak Classifications and repair timelines are now defined with specific details assigned to each type. Generally, the Leak Classifications are as follows:
Grade 1 – A leak that represents an existing or probable hazard to persons or property, requires immediate repair or continuous action until the conditions are no longer hazardous.
Grade 2 – A leak that is recognized as being non-hazardous at the time of detection but justifies scheduled repair within six months of discovery.
Grade 3 – A leak that is non-hazardous at the time of detection and justifies scheduled repair within 24 months of discovery.
Repair can include repair, replacement, or abandonment. Small operators shall classify all leaks as Grade 1 and repair immediately.
A remote hearing is scheduled for August 5, details can be found on the Commission's website. Contact Lauren.Tipton@ElementalCompliance.com for a copy of the rule language, questions on state regulations, and to keep your pipeline safety programs up to speed with the rapidly changing regulatory landscape. Also consider signing up for our Regulatory Compliance Newsletter on our website where we provide real time updates on PHMSA and state pipeline safety activities straight to your email. Sign up at https://www.elementalcompliance.com/about.