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DEQ conducts additional sampling at Payette Lake

August 27, 2021

VALLEY COUNTY — A second round of water quality sampling at Payette Lake confirmed normal levels of cyanobacteria consistent with high water quality.

Final lab results are expected soon following a comprehensive analysis at a national lab that specializes in identifying cyanobacteria and their cyanotoxins. The Idaho Department of Environmental Quality will share that information with the public as soon as it’s available.

DEQ collected samples at three Payette Lake locations, including the western edge of North Beach, a northwestern portion of the lake, and a section between Brown Park and Mile High Marina.

The additional samples were taken as a follow up to public concern regarding a dog that became ill after swimming in Payette Lake. Results from samples collected on August 17, 2021, near where the dog had been swimming did not indicate the presence of the most common types of cyanobacteria found in Idaho surface waters. Subsequent sampling efforts conducted on August 23, 2021, indicate that cyanobacteria were not present in concentrations that would indicate a health risk, and cyanotoxins are not present at that location.

August 23 sampling efforts revealed normal levels of cyanobacteria at North Beach and at the dog park betweenBrown Park and Mile High Arena.

Cyanobacteria are a natural component of biological communities found in water or growing at the bottom of lakes, ponds, rivers, and streams, according to the Interstate Technology and Regulatory Council’s Strategies for Preventing and Managing Harmful Cyanobacterial Blooms. Just because cyanobacteria are present in a portion of a water body does not mean they are present in high enough concentrations to present a threat to human or animal health.

While Payette Lake continues to have high water quality and normal cyanobacteria population numbers, cyanobacteria and the toxins they can produce continue to pose a serious health risk in many water bodies across Idaho. DEQ always recommends people use caution when recreating in and around water, especially during the hot summer months. Waterborne germs and parasites may be present in any lake or river. Water should always be purified before drinking, even from water bodies with very good water quality. Water that looks green or scummy should be avoided and purification may not make it safe to drink.

To learn more about drinking water from lakes and rivers, visit and

To learn more about current health advisories or report a suspected bloom, visit

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