JEFFERSON CITY, Mo. (AP) -- The Missouri Department of Natural Resources is investigating the release of about 1,000 gallons of untreated sewage into Weatherby Lake outside Kansas City.

The agency says the release happened late Wednesday when a power failure caused a lift station to go off-line. While the pumps were off, sewage overflowed from a manhole into Weatherby Lake.

DNR took samples from the lake Thursday, but said Friday that recent heavy rain will affect the sampling results. Residents were advised to avoid contact with the lake water for now.