YAKIMA (AP) — An environmental group based on the Yakama Indian Reservation has filed a federal lawsuit against the Indian Health Service for failing to respond to records requests about groundwater nitrate pollution.

Friends of Toppenish Creek requested records from the Indian Health Service last May, but says it met with delays and vague answers that violate the Freedom of Information Act.

That's according to the complaint filed in U.S. District Court of Eastern Washington on Tuesday.

The Yakima Herald-Republic says a call to the Indian Health Service public affairs office was not immediately returned Tuesday.

Friends of Toppenish Creek is asking the court to order the Indian Health Service to provide the documents and cover the group's legal fees in pursuing this case.