MADISON, Wis. (AP) — A manure spill in west-central Wisconsin has resulted in a fish kill stretching more than a mile, state environmental regulators said Tuesday.

An angler reported the fish kill in Moore Creek in Monroe County on Saturday, state Department of Natural Resources officials said.

The DNR traced the kill to a manure spill at Spring Valley Holstein Inc., a dairy farm east of Norwalk. They said the farm’s manure transfer system failed but did not elaborate. They did not identify the farm, saying an investigation is ongoing.

The spill affected at least 1.2 miles (1.9 kilometers) of Moore Creek and an adjacent tributary. DNR officials said they didn’t have an estimate of how much manure has been spilled but drinking water supplies shouldn’t be affected.

The DNR, county officials and the farm are still working on ways to prevent additional runoff from reaching local waterways, the agency said.

Calls to two telephone listings for Spring Valley Holstein on Tuesday afternoon were met with recorded messages saying the numbers had been disconnected or were no longer in service.