Yet by easing the public’s concerns about water quality, the visible improvements made possible by the Clean Water Act have ironically paved the way for the new rule that will further increase pollution.

“The Clean Water Act succeeded just enough to doom itself,” said Estrin, whose organization helps people across the country contend with coal ash leaks, chemical spills, algal blooms, drinking water contamination, and all matter of water crises. “The rollback will take us backward. And most people don’t remember just how bad that was.”