PHMSA Issues Proposed Rule Seeking to Impose Enhanced Safety and Operational Requirements on Carbon Dioxide Pipelines
By Jones Day
On January 10, 2025, the Pipeline and Hazardous Materials Safety Administration(“ PHMSA”) issued a proposed rule setting forth revisions to the federal Pipeline Safety Regulations(“ PSR”)( 49 C. F. R. Parts 190-99) to include safety standards and reporting requirements for all phases of carbon dioxide pipelines. PHMSA states that the revisions are in response to multiple events, including congressional mandates directing PHMSA to regulate both carbon dioxide in gas as well as( sub-critical) liquid phases, anticipated expansions of pipeline infrastructure transporting carbon dioxide in all phases based on initiatives to address climate change( e. g., in conjunction with carbon capture, sequestration, and storage activities), and lessons learned from the February 22, 2020, rupture of a supercriticalphase carbon dioxide pipeline near Satartia, Mississippi.
The rule describes 18 proposed changes to the PSR. PHMSA first proposes to expand the scope of the regulations“ to ensure more carbon dioxide pipelines are subject to meaningful safety and reporting requirements” set forth in Part 195 of the PSR. The revisions would accomplish this by first extending the PSR to regulate not only supercritical-phase carbon dioxide, but carbon dioxide in the gas and liquid phases as well. PHMSA also proposes to lower the threshold of carbon dioxide molecules needed to be present in the product stream in order to qualify as a“ carbon dioxide” pipeline. The new threshold would include pipelines that have greater than
14 DITCHMEN • MARCH / APRIL 2025