Clean Water Act leaves about 55% of water flowing out of rivers vulnerable to pollution, study suggests

The Supreme Court ruled in 2023 that rivers that only flow in response to weather events—called ephemeral streams—do not fall under the protection of the Clean Water Act. Research published in the journal Science, led by University of Massachusetts Amherst recent doctoral graduate Craig Brinkerhoff and co-authored by colleagues at Yale University, suggests that this now leaves many U.S. waterways vulnerable to pollution.