Speaking to a room of producers facing tight margins and regulatory bottlenecks, Environmental Protection Agency (EPA) Administrator Lee Zeldin vowed to dismantle standard federal mandates on Diesel Exhaust Fluid (DEF) systems. Zeldin made the remarks during a focused agricultural roundtable with Oklahoma farmers and ranchers on Saturday, May 30, emphasizing that current mitigation protocols are actively threatening farm survival during peak operating windows. Zeldin was hosted by Oklahoma Farm Bureau President Stacy Simunek on the ranch operation of John Pfeiffer, Jr in Logan County.
“When a tractor goes down in the middle of a harvest, it results in lost time and lost money, great frustration,” Zeldin stated following the meeting in comments provided to Oklahoma Farm Bureau’s Communications team. He acknowledged the precarious economic reality gripping the sector, noting that many producers are currently working to survive on “extremely low margins”—frequently lower than the non-farming public realizes—while bad years leave many operators unable to pay themselves at all.
“When it’s time for harvest, and on particular crops, they need their equipment to work,” Zeldin added. “They definitely don’t need a federal regulation to prevent them from being able to do their job.”
Timeline of Federal Action on DEF Requirements
Zeldin outlined a multi-phase strategy executed by the EPA and the Trump administration over the last ten months designed to systematically scale back equipment restrictions:
- August 2025 (Iowa State Fair): Alongside Agriculture Secretary Rollins, Senator Joni Ernst, and Small Business Administration (SBA) Administrator Kelly Loeffler, the EPA announced an initial reversal to DEF deratements, launching direct initiatives with manufacturers to update software and assist equipment owners.
- February 2, 2026 (Right to Repair Guidance): The EPA issued formal guidance clarifying that producers possess the right to repair their own tractors and non-farm machinery, or utilize trusted independent mechanics rather than being forced to rely on costly, geographically distant authorized dealerships.
- February 2026 (Manufacturer Demand Letters): The agency issued formal demand letters to 14 major engine manufacturers—representing 80 percent of the market share—compelling them to surrender internal data regarding DEF system failures.
- March 2026 (White House Actions): President Trump announced new administrative guidance on the South Lawn targeting the total elimination of DEF sensor requirements.
The Push for Permanent Eliminating of Deratements
According to Zeldin, the agency is leveraging data secured from the 14 engine manufacturers to push through a permanent regulatory overhaul. The EPA’s proposed 2027 nitrous oxide rules—currently under interagency review at the Office of Management and Budget (OMB)—look to completely and permanently eliminate DEF deratements altogether.
Concurrently, a permanent legislative remedy is advancing through Capitol Hill. Zeldin highlighted a last-minute amendment added to the House version of the pending Farm Bill that targets DEF mandates and broader tractor emissions requirements. That legislation is now awaiting action in the Senate.
Zeldin noted that internal shifts within the EPA’s Office of Enforcement and Compliance Assurance reflect this deregulation policy, citing President Trump’s recent pardon of Wyoming operator Troy Lake as a benchmark for the administration’s intent.
“We have heard the calls loud and clear from across the country, including right here in Oklahoma,” Zeldin concluded. “It is our full intention, desire, [and] intent to do the maximum amount possible decommissioning these restrictions pursuant to the law.”
Audio and pictures courtesy of Oklahoma Farm Bureau
