Algal bloom at Elm Lake not affecting Aberdeen water supply

An algal bloom at Elm Lake, one of Aberdeen’s main sources of water, was identified Aug. 5 by the South Dakota Department of Environment and Natural Resources.

It’s along the face of the dam at Elm Lake, according to a department report.

However, Aberdeen residents don’t have to worry, according to Bob Braun, Aberdeen water superintendent.

Not only is Aberdeen not currently getting a supply of drinking water from Elm Lake, but there are purification and testing efforts that would alarm officials of danger even if it was.

“There definitely was some algal there on the face of the dam,” Braun said. “But we do testing here at the plant to ensure there are no toxins in the water, and by the time what was in the dam would come down, it would be changed.”

Aberdeen also taps drinking water from wells.

Harmful algal blooms are common during warm months, and occur “when toxin producing algae grows excessively in nutrient enriched lakes and ponds,” according to a news release from the South Dakota Department of Environment and Natural Resources.

“The conditions are right for harmful algal blooms, so please use caution if you suspect a bloom is occurring,” Hunter Roberts, secretary for the department, said in the news release. “When in doubt, stay out.”

Last year, toxic algal was found in Lake Cottonwood, which is 12 miles south of Redfield, but was well below what the World Health Organization classifies as “low risk algal bloom,” which is 20,000 cells per milliliter. At Lake Cottonwood, the highest recorded result was 2,932 per milliliter, according to the state.

Those details are not yet available for the Elm Lake bloom.

An interactive map showing algal blooms throughout the state of South Dakota can be found at denr.sd.gov. The map will be continuously updated with reports of algal toxins when made available.