Senate Western Caucus Members Push for Commonsense Cold Weather Diesel Reliability Act

March 12, 2026

Washington, D.C.-Senate Western Caucus Chair Cynthia Lummis (R-WY) and Vice Chair Dan Sullivan (R-AK) today called on the Environment and Public Works (EPW) Committee to pass the Cold Weather Diesel Reliability Act with bipartisan support. They were joined by fellow Caucus and Committee member Senator Pete Ricketts (R-NE).

The Cold Weather Diesel Reliability Act would update current Environmental Protection Agency (EPA) regulations that cause diesel exhaust fluid (DEF) system malfunctions that can force diesel engines to shut down in extreme cold. These malfunctions cause critical delays that impact emergency vehicle response times and cause agriculture supply chain problems.

Witnesses included Todd Fornstrom, a fourth-generation farmer who served nine terms as president of the Wyoming Farm Bureau, and Ryan Anderson, commissioner of the Alaska Department of Transportation and Public Facilities (DOT&PF). Anderson testified that 70%-80% of diesel equipment issues in Alaska are related to DEF.

Here's what the Senate Western Caucus members said:

"The EPA under Biden knew the DEF systems didn't work well and posed a risk to public safety, and they mandated them anyway," said Lummis. "What we need to do, in some ways, is what Mr. Whitehouse described. We do need to remediate NOx emissions, we need to reduce them, but there are ways to reduce them and still keep diesel engines running. That's what this bill is about."

"None of us are saying we shouldn't do anything about NOx and SOx, but we do need to have regulations that are not a one-size-fits-all that really, really penalizes states like mine in a huge way," said Sullivan. "You know, a reg [sic] written by lawyers in D.C. that don't have a clue about any of this stuff, not a clue, that's not right. That's not the way the federal government is supposed to work, and we're going to fix it.

"Nebraska agricultural producers report that emissions related issues, particularly with the DEF systems account for a majority for their machinery repairs, sort of what my colleague from Alaska was just saying," said Ricketts. "A major grievance is that when a DEF censor fails or a system malfunction, it often triggers limp mode, where a tractor or combine loses power and speed, causing critical delays during planting and harvesting."

"Legislative reform that increases public safety is just commonsense, and I look forward to working with the committee on this," said Ricketts.

Watch the full EPW Committee hearing here.

Read the full bill text for the Cold Weather Diesel Reliability Act here.

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