When a pipeline operator has a question about how federal safety regulations apply to its operations, it can submit a request to the Pipeline and Hazardous Materials Safety Administration (PHMSA)’s Office of Pipeline Safety asking for an official interpretation. It’s a sensible system: operators get clarity, the agency creates a record of its reasoning, and the public can see how the rules are being applied in the real world. The answers can determine whether a pipeline is subject to stringent federal safety requirements or more limited oversight, meaning there are real consequences for the communities and the environment near those pipelines.
In April 2025, PHMSA took that a step further, announcing an update to its interpretations process that, for the first time, would allow stakeholders to review and comment on interpretation requests before the agency issues its final response. PHMSA described this as an opportunity for “peer-to-peer guidance” on regulatory compliance and promised greater transparency. That is good policy. Pipeline safety isn’t just a technical matter between regulators and industry; it affects people who live and work near pipelines and who deserve a voice in how the rules are interpreted and applied.
But transparency requires follow-through, and that’s where things break down.
The Gaps Tell a Story
One of the simplest ways to assess whether an agency is keeping up with its workload is to look at whether its published record is complete. For PHMSA’s interpretation process, it is not.
Interpretation requests are assigned sequential identification numbers, e.g. PI-22-0001, PI-22-0002, and so on. By comparing the numbers of requests received against the numbers of published responses, PST has identified gaps: places where a request appears to have been received but no response has been published. For example, PHMSA’s Letters of Interpretation page provides response documents for PI-24-0007 and PI-24-0009, but not for PI-24-0008. Based on that analysis, there appear to be at least 17 missing or unaddressed interpretations spanning requests received in 2022, 2023, and 2024. That’s more than a third of the interpretations received during that period with no visible resolution.
To be clear, there may be explanations for some of these gaps. Requests may have been withdrawn, consolidated, or handled through other channels. But those explanations should be visible. The public shouldn’t have to speculate about whether an interpretation was issued, ignored, or quietly resolved in a way that never made it into the public record. The infrastructure for increased transparency exists, but PHMSA is deliberately choosing against it.
The problem has only grown more acute in 2025. The current administration has yet to publish a single interpretation response for any request submitted after January 20, 2025. Since October 2025 alone, 15 new requests have been submitted (one of which was withdrawn, one of which was rescinded), and only one has received a response. (One comment period only closed just last week) Agency policy asks operators to submit requests at least 120 days before they need a response, but the backlog keeps growing.
Making matters worse, there are signs that some operators may be finding ways around the formal process entirely. Consider the case of Sable Offshore. In November 2025, Sable wrote to federal pipeline authorities declaring that the Santa Ynez pipeline—shut down following a 2015 ExxonMobil oil spill that sent 100,000 gallons of crude oil across the California coast—should be reclassified as an interstate pipeline and therefore subject to federal rather than state jurisdiction. Within a month, the Trump administration agreed.
Whatever the merits of the underlying jurisdictional question, the process by which that determination was made is striking. Despite the fact that this was clearly a request for a written regulatory interpretation, question, or opinion concerning a pipeline safety issue, Sable and PHMSA operated outside of the regulatory code and PHMSA’s stated policy of transparency. There was no public comment period. There was no queue to wait in. Sable wrote a letter with a declaration and request for concurrence, and within weeks received a favorable regulatory determination that could reshape its entire business model, one that, notably, hinges on overcoming state-level resistance to reopening a pipeline that was shut down since the 2015 spill. Meanwhile, other operators wait months or years for responses to requests submitted through the formal process. That disparity deserves scrutiny.
When Public Participation Goes Nowhere
Even when the public does engage with the process, there’s little evidence it matters. PST has submitted comments on interpretation requests, but those comments are not made publicly available. There is no indication of whether they are considered, and there is no follow-up. Meaningful participation requires more than an open comment period. It requires that public comments are visible to all, and that the agency’s reasoning, including how it weighed outside input, is reflected in its published response. Right now, none of that is reliably happening.
What We’re Still Waiting For
A year after PHMSA’s commitment, PST is asking for follow-through. Specifically, PST calls on PHMSA to:
Publish complete information with each request. In a few interpretation requests, PST has observed that the information provided does not seem complete. A submission that is missing information material to the interpretation at hand, PHMSA should obtain that information and make it publicly available. The public cannot comment meaningfully on an incomplete record.
Post the status of pending requests and account for gaps. Operators, the public, and safety advocates should not have to guess whether a request is under review, awaiting additional information, or simply sitting in a queue. A regularly updated status tracker would cost little and add significant accountability, and PHMSA could simply maintain this information on its existing Letters of Interpretation page.
Make public comments visible. When members of the public take the time to comment on an interpretation request, those comments should be accessible to anyone who wants to see them, not filed away where no one will see or learn from public input.
Publish timely responses. The regulations state that requests should be submitted at least 120 days before the requestor needs a response. From the public’s perspective there appear to be requests that are years outstanding. PHMSA should publish responses in a timely manner, and when responses will be delayed, the agency should say so publicly and explain why.
Why This Matters
Pipeline safety requires transparency. Operators need clear guidance to make compliance decisions. The public needs visibility into how rules are being interpreted and applied near their homes and communities. Advocates and researchers need access to PHMSA’s reasoning to evaluate whether the regulatory framework is working as intended.
An interpretation process that operates as a black box where requests pile up, responses go unpublished, and public participation has no visible effect undermines all of that. It doesn’t serve operators, who need timely answers. It doesn’t serve the public, who deserve to know how safety rules are being applied. And it doesn’t serve PHMSA’s own stated goals of transparency and peer-to-peer learning.
PHMSA has the tools to fix this. It has made a commitment to do better. We’re asking the agency to follow through because the communities that live alongside the nation’s pipeline infrastructure are counting on it.
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