Federal regulators propose safety rules for small and mobile LNG plants

The Pipeline and Hazardous Materials Safety Administration on Tuesday proposed rewriting its safety rules for liquefied natural gas plants. The rules would include the first specific requirements for permanent small-scale plants and updated rules for mobile or temporary units.

The agency's LNG rules have not been updated since 2006. They rest largely on the National Fire Protection Association's 2001 industry standard, NFPA 59A, which PHMSA says is now seven editions out of date. The proposal would adopt the 2026 edition, using its chapter 17 for permanent small-scale plants and chapter 14 for mobile units. PHMSA says small-scale plants carry lower risks than larger ones and should be regulated accordingly. Congress ordered the agency to write small-scale rules in 2016.

Mobile and temporary LNG facilities grew from eight in 2004 to 43 last year, the agency said. Small-scale LNG increasingly serves niche markets such as off-grid power and oil and gas drilling equipment. Under the proposal, a mobile unit could operate up to six months before needing a special permit.

In Alaska, LNG is already trucked to Fairbanks. "We are seeing some small-scale sales of gas," Dan Stickel, the Department of Revenue's chief economist, told a legislative conference committee June 27.

The proposal would also write into the rules existing agency guidance that operators model a full rupture of truck transfer hoses, whatever the hose diameter. PHMSA cited a fatal September 2023 incident in Toppenish, Washington, where a transfer hose detached as a truck pulled away from an LNG facility.

PHMSA estimates the changes would save about $98 million a year, though it said many of the savings and some of the costs could not be quantified.

Comments are due Jan. 4, 2027, at the federal docket.