BANGOR (AP) — The state of Maine is suing the Environmental Protection Agency, saying the federal agency has failed to approve the state’s water quality standards under the Clean Water Act.

The state filed its lawsuit in U.S. District Court in Bangor. The suit says EPA is responsible for approving Maine’s revisions to its water quality standards or identifying changes needed for federal approval.

The suit says the EPA has not taken action about unspecified Maine waters it believes are within Indian territories. The state wants the agency to identify the waters. Attorney General Janet Mills says in a statement that EPA’s lack of action leaves Mainers unaware of where the waters are and water the standards are.

An EPA spokesman didn’t immediately return a call from The Associated Press.