The Supreme Court's decision is the latest in which conservative justices have reined in pollution control efforts.

The justices found that the EPA cannot impose generic prohibitions against violating water quality standards. The ruling could affect businesses and other cities that sit on bodies of water, including Boston.

By a 5-4 vote, the court's conservative majority ruled that the Environmental Protection Agency overstepped its authority under the Clean Water Act with water pollution permits that contain vague requirements for maintaining water quality. The decision is the latest in which conservative justices have reined in pollution control efforts.