The U.S. Environmental Protection Agency announced a sweeping deregulatory action on February 12, rescinding the 2009 greenhouse gas (GHG) Endangerment Finding and eliminating related federal GHG vehicle emission standards for light-, medium-, and heavy-duty vehicles.
The action, unveiled by President Donald Trump and EPA Administrator Lee Zeldin, was described by the Agency as the largest deregulatory move in U.S. history.
Under the previous rule, greenhouse gas regulations for heavy-duty trucks were based on federal Phase 1 and Phase 2 Clean Air Act standards. These rules set carbon dioxide emission and fuel efficiency requirements for many types of vehicles — including semi-trucks and water well drilling rigs — with the goal of reducing greenhouse gas emissions and encouraging greater use of fuel-efficient and electric vehicle technologies.
EPA leadership stated that removing the related rules will lower vehicle costs, reduce regulatory burdens, and allow consumers more freedom to purchase vehicles.
“The Endangerment Finding has been the source of 16 years of consumer choice restrictions and trillions of dollars in hidden costs for Americans,” Zeldin said.
As is often the case with major deregulatory actions, the rescinding of the rule is expected to prompt legal challenges from states and environmental organizations. It is also anticipated that some states may seek to fill the regulatory gap by advancing or strengthening their own vehicle emissions requirements.
NGWA previously submitted comments supporting the EPA’s reconsideration of GHG regulations affecting trucks and work vehicles commonly used by groundwater professionals. In its comments sent on September 4, 2025, NGWA emphasized that most well drilling and groundwater service operations rely on vehicles that typically travel short distances and accumulate relatively low annual mileage, meaning regulatory compliance costs could outweigh potential emissions benefits.
Click here to read NGWA’s comments from September 2025.
Click here to read more from the EPA’s announcement.