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Cyanobacteria Harmful Algal Blooms

DEQ and the Idaho Department of Health and Welfare (DHW) each play a role in identifying, responding to, and monitoring cyanobacteria harmful algal blooms (HABs).

The health advisory map is available on DHW’s Recreational Water Health Advisories web page.

Our staff is responsible for sampling Idaho water bodies and analyzing water quality data. We provide the sample results to DHW and the public health district in the area where a citizen reported the HAB, and they decide if it warrants a health advisory.

Water Quality Test Results

As water quality sample results become available, you will see them in the table below. 

County Waterbody Sample Date *Threshold Level
Fremont Island Park Reservoir 6/13/2024 Below

*For more details on threshold values, please click on the “Idaho DEQ Cyanobacteria Harmful Algal Bloom Information” tab below.

Report a Potential Harmful Algal Bloom

Report a potential harmful algal bloom: 

Health Concerns

Idaho’s health agencies offer citizens education and advice on cyanobacteria exposures. Contact the Idaho Department of Health and Welfare or your local public health district for health concerns and cyanobacteria information.

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