Supreme Court weakens EPA's authority on water pollution regulation.

The US Supreme Court has ruled in favor of an Idaho couple who challenged the Environmental Protection Agency's (EPA) determination that their property contained wetlands protected by the Clean Water Act of 1972. The court embraced a new test for determining if adjacent wetlands are covered by the Act, which could undermine water quality and flood control, according to four justices. The ruling marks the latest instance of the court backing a challenge to the scope of the EPA's ability to regulate in the environmental arena under existing law. The decision could cast doubt on the lawfulness of some parts of the EPA's new regulation expanding the definition of waterways that are protected under the Clean Water Act.