Scientists have unveiled rapid fluctuations in river water temperature across the United States (US) with rivers controlled by dams showing more frequent and volatile thermal changes.

The justices ruled that the agency cannot impose generic prohibitions against violating water quality standards.

The 5-to-4 decision is the latest setback for the agency and could have sweeping implications for curtailing water pollution offshore. By Abbie VanSickle and Adam Liptak Reporting from Washington ...