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The health advisory map has moved from our website to the Department of Health and Welfare’s (DHW) website. Please see the DHW’s Recreational Water Health Advisories web page for more information about possible health effects and symptoms associated with cyanobacteria and the map showing the locations of Recreation Water Health Advisories.
The Idaho Department of Environmental Quality and the DHW each play a role in identifying, responding to, and monitoring cyanobacteria harmful algal blooms (HABs).
Our staff is responsible for sampling Idaho water bodies and analyzing water quality data to identify potential threats to people and pets, and we provide the sample results to DHW.
Visit the Idaho Department of Health and Welfare Recreational Water Health Advisories web page for information on active blooms, health advisories, and health information.
Potenial Bloom and Water Quality Sample Map
The map below displays the estimated abundance or number of cyanobacteria cells in large water bodies, based on calculations from the satellites. The map is a screening-level analysis tool. The Idaho Department of Health and Welfare will make health advisory decisions based on results from water quality samples. No regulatory decisions, or signage postings, should occur based solely on information from the map.
Satellite data allows our staff to monitor Idaho’s lakes and reservoirs remotely and see an estimate of how many cyanobacteria are in the water. The data comes from NASA and European Space Agency satellites, and updates are usually received every 3 -4 days.
The black dots represent our water quality sample results. Click on the black dots to reveal the data.
Cyanobacteria Fact Sheets
- Cyanobacterial Blooms: Frequently Asked Questions
- Cyanotoxin Removal
- Treatment Considerations for Cyanobacterial Cell Removal
- What are cyanobacteria harmful algal blooms (CyanoHABs)?
- Monitoring Methods for Harmful Algal Blooms in Source Water
- What is a cyanotoxin and how can it be released into the water?
- CyanoHABs and Public Drinking Water Systems
- How do I prepare my public drinking water system in case a bloom occurs in my source water?
- Communicating Cyanotoxin Risk with the Public
- Cyanotoxin Sample Collection Considerations
- Potential Indicators of Cyanobacteria Presence in Source Water
Report a Health Concern
Idaho’s health agencies are responsible for educating and advising the public on cyanobacteria exposures.
Idaho’s seven public health districts develop public health advisories, in consultation with DEQ, based on lab result analysis. The Idaho Department of Health and Welfare maintains a Harmful Algal Blooms FAQ page and Waterborne Illness page, which contain educational material and general information about potential illnesses from recreational waters and drinking water.
For information on health concerns and cyanobacteria, please contact the Idaho Department of Health and Welfare or your local public health district.
Report a Potential Cyanobacteria Harmful Algal Bloom
Use the link below to provide information about a potential cyanobacteria harmful algal bloom.
Cyanotoxins present a real health threat to people and animals. Toxin exposure primarily occurs from ingesting the cyanobacteria and the water they live in but it also occurs with skin contact. Ingesting cyanotoxins, which can remain after a visible bloom subsides, can result in a range of health effects, many of which are easily misdiagnosed. Symptoms include:
- Skin irritation
- Upset stomach
- Hay fever or allergies
- Neurotoxic effects, which includes trouble breathing
- At very high levels, death.
Anyone with symptoms should seek medical attention.
For more information on health-related questions, please contact the Idaho Department of Health and Welfare or your local public health district:
What are Cyanobacteria?
Cyanobacteria are photosynthetic bacteria that occur naturally in Idaho’s lakes and rivers. Many of us learned about “blue-green algae” in school, but these algae are actually bacteria that photosynthesize like plants. The photosynthetic structures within the bacterial cell contain the blue-green pigments that give cyanobacteria their color and their name.
Where And When Do Cyanobacteria Blooms Occur?
Cyanobacteria are present in nearly all water bodies but typically exist in numbers too small to cause problems (sight, smell, and cyanotoxins). However, a variety of environmental conditions influence cyanobacteria population growth. Summertime conditions can allow cyanobacteria populations to “bloom” to high enough numbers that a variety of toxins, known as cyanotoxins, are produced in quantities that can be harmful to people and animals. These ideal conditions include warm temperatures, low or slow water flow, high nutrient levels, strong light, and calm weather.
What Do They Look Like?
Cyanobacteria harmful algal blooms (blooms) in Idaho can vary in appearance, often looking like bright green water or pea soup, pollen, grass clippings, spilled paint, mats, green or blue-green foam, or dense surface scum. Blooms can range in color from blue and bright green to brown, red, and even white. Some blooms may produce a foul odor.
What Should I Do If A Health Advisory Is Issued?
- Avoid exposure to water experiencing a HAB. Take extra precautions to ensure children, pets, and livestock are not exposed to the water.
- Do not consume water with a HAB. Neither boiling nor disinfecting water removes cyanotoxins from water.
- Consume only the fillet portion of fish exposed to a HAB. Cyanotoxins can accumulate in fish. Removing the fat, organs, and skin minimizes the exposure. Wash hands after handling. The risk associated with consuming fish caught in waters with a HAB is unknown and under research.
- Enjoy the other recreation opportunities in the area!
*Health advisories are intended to advise the public about a potential health risk. Health advisories are not water body closures.
Can a Bloom Affect My Drinking Water?
Cyanobacteria and cyanotoxins can present dangers if you receive your drinking water from surface water (or influenced by surface water). However, the toxins can be removed safely before reaching the distribution system through specific treatment methods. Learn about drinking water and cyanobacterial harmful algal blooms on our Contaminants in Drinking Water web page.
Resources
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Water Quality Standards Analyst