The U.S. Supreme Court appeared receptive to upholding the U.S. Environmental Protection Agency's right to place generic limits on ocean sewage discharge as San Francisco took its contentious battle to the high court.

San Francisco may have just handed the right-wing judges the ability to undermine decades of environmental law.

The justices heard arguments on Wednesday in a long-simmering dispute between San Francisco and the E.P.A. over regulation of water pollution.

In a case that could set new standards for pollution of offshore waters, the Supreme Court appeared sympathetic Wednesday to San Francisco’s argument that it should be held responsible only for the amount of pollutants discharged from its sewage systems and not for any decline in water quality in the ocean or San Francisco Bay.

The Supreme Court appeared ready in oral arguments Wednesday to restrict the EPA’s ability to set broad water quality standards for sewage and other systems as part of a challenge from San Francisco to the agency’s powers under the Clean Water Act.