Though EPA involvement is improving polluted waterways like Chesapeake Bay, proposed legislation would limit the agency's ability to override state decisions regarding water quality. Photo: John J. Young

Claiming it would undo Clean Water Act provisions “that have been the underpinning of 40 years of progress in making the nation's waters fishable, swimmable, and drinkable,” President Barack Obama says he'd veto proposed legislation limiting U.S. EPA's ability to overrule state decisions regarding water quality.

States are responsible for protecting waterways once EPA signs off on their plans, but the agency can step in if it thinks resources aren't being adequately protected. A bill recently passed by the U.S. House of Representatives strips EPA of its oversight authority in an effort to enhance cooperation between the federal and state levels of government.

“By not taking action, Congress is tacitly giving EPA authority to do what it thinks is politically necessary,” says Rep. Nick Rahall (D-W.Va.), the bill's sponsor. “This isn't about whether we support EPA's ends. It's about whether we should use any means to reach those ends.”

Critics say the legislation impedes the federal government in protecting public health and the environment. For example, in January EPA revoked a water permit for a large mountaintop-removal mine in West Virginia; and the agency also has been instrumental in stemming algae blooms in Florida by limiting nutrient-rich runoff.

An effort to exempt multistate watersheds from the bill failed.