ST. LOUIS (AP) – President Joe Biden’s administration has finalized regulations that protect hundreds of thousands of small streams, wetlands and other waterways, repealing a Trump-era rule that federal courts had thrown out and that environmentalists said left waterways vulnerable to pollution.

The rule announced Friday defines which “waters of the United States” are protected by the Clean Water Act. For decades, the term has been a flashpoint between environmental groups that want to broaden limits on pollution and farmers, builders and industry groups that say extending regulations too far is onerous for business.

The EPA and the Department of the Army say the rule is based on definitions in place prior to 2015, and that they wrote a “durable definition” of waterways to reduce uncertainty.