EPA Acts to Recognize State Authority to Reduce Pollution from Older Diesel Locomotives

(Washington, D.C. – November 1, 2023) – The Environmental Protection Agency took important action today to more fully recognize states’ authority to reduce the harmful pollution emitted by America’s older diesel trains.

EPA unveiled its final amendments to the rules that address federal preemption of state air pollution standards for new diesel locomotives. The amendments recognize state and local authority under the Clean Air Act to regulate pollution emitted by diesel locomotives that are not new.

“Diesel trains contribute significantly to unhealthy air quality and climate change,” said Alice Henderson, Director of Transportation and Clean Air Policy for Environmental Defense Fund. “Train cargo volume and rail traffic have increased in recent decades and are expected to continue to grow, and most trains that operate today are not subject to EPA’s modern pollution controls for new locomotives. EPA’s action today will help ensure states can take common-sense and urgently needed actions to clean up the pollution from these older, high-polluting diesel engines, and that will protect people’s health and save lives.”

Diesel locomotives emit climate pollution, smog-forming pollution, and other dangerous air pollutants including particulate matter, sulfur dioxide, and carbon monoxide. Recent data shows that the U.S. diesel locomotive fleet currently in use is dominated by older, dirtier trains that are subject to EPA’s less protective emissions standards. Less than a quarter of the locomotives in today’s fleet meet the most protective Tier 3 or Tier 4 standards that were adopted in 2008.

EPA’s action today revises regulations that were adopted a quarter-century ago, in 1998. As EPA states in its final rule, the revisions finalized today will align EPA’s regulations with the plain text of the Clean Air Act, “better achieving the legislative intent” of the statute to preserve states’ ability to adopt protections for non-new locomotives and engines.

EDF submitted comments to EPA supporting today’s updates after they were proposed in April of this year, and also submitted joint comments with the Moving Forward Network and other organizations.