The U.S. Geological Survey admits the release of water from a federal reservoir in northeastern Kansas last month sent algal toxins into the Kansas River.
The agency says the controlled release from Milford Lake occurred Aug. 31, two days after the lake was closed for recreation because of a large bloom of blue-green algae. The release sent the tainted water into the Kansas River, a main drinking water source for more than 600,000 residents in eastern Kansas.
The USGS said Tuesday no traces of algal toxins were found in samples of treated drinking water.
Several other Kansas lakes have experienced algae blooms this year. Algal toxins can be poisonous to people, aquatic life, pets and livestock.