Harmful Algal Blooms (HABs)

Know it.

Blue-green algae can look like a crust on the water, grass clippings, green cottage cheese, scum or like spilled green paint or green pea soup.

Avoid it.

  • Respect advisories and warnings announced by the NDDEQ. All water advisories and warnings are posted on this page.
  • Do not swim, water ski, or boat in areas where the water is discolored or where you see foam, scum or mats of green or blue-green algae on the water; or let pets swim in or drink from affected waters.
  • If you or your pet accidentally swims in water that might have a cyanobacteria bloom, rinse off with fresh water as soon as possible.
  • Do not irrigate lawns with pond or lake water that looks scummy or has an awful odor.

Report it.

Report suspected blue-green algae blooms to the NDDEQ by using the online form linked above, calling 701-328-5210 or emailing DEQ-HAB@nd.gov. Because it can take time to receive laboratory test results, we urge people to be cautious and avoid waters that look discolored, scummy, or have a foul odor.

Active Harmful Algal Bloom Advisories/Warnings:

The NDDEQ responds to reported blooms across the state and tests water for toxins. If toxins are at an unsafe level, the NDDEQ issues advisories and warnings to the public.

An Advisory means a blue-green algae bloom is present in portions of the waterbody. The blue-green algae may be harmful to humans and pets. To reduce the risk of illness:

  • Do not swim, waterski, or tube if the water looks like spilled green paint or pea soup.
  • Avoid swallowing water and watch small children and pets who may ingest water.
  • Rinse off with clean water after swimming.
  • Stay away from areas of scum when boating.

A Warning means a blue-green algae bloom is present over a significant portion of the lake and excessive microcystin levels have been measured.

  • Avoid contact with the water.
  • Individuals should not take part in contact recreational activities (e.g., swimming, water skiing, kayaking and paddle boarding).
  • Do not allow pets in the water.

Current List of Lakes in Table Format

Current Harmful Algal Bloom Map

The Harmful in Harmful Algal Bloom

A HAB is an overgrowth of, cyanobacteria (blue-green algae) in surface water. Cyanobacteria are microscopic organisms found in all types of water. They are more like bacteria than plants, but because they live in water and use sunlight to create food (photosynthesis) they are often called "blue-green algae." Cyanobacteria are important to freshwater ecosystems because they make oxygen as a by-product of photosynthesis, and they are a food source for other organisms.

Under certain environmental conditions, cyanobacteria (blue-gren algae) can multiply quickly and form a bloom. Some species of cyanobacteria produce cyanotoxins that are released when the cells die and rupture. The toxins can cause harm to people, wildlife, livestock, pets and aquatic life. Almost every year in North Dakota, a few cases of pet and livestock deaths occur due to drinking water with HABs.


Specific human health effects are:

  • Allergic-like reactions
  • Skin rashes
  • Eye irritation
  • Gastroenteritis
  • Respiratory irritation
  • Neurological effects

What Grows Algae?

  • Excess nutrients (phosphorus and nitrogen)
  • Warm water temperatures
  • Slow-moving water
  • Sunlight

The major source of food for algae is nutrients that enter North Dakota lakes from:

  • Fertilizers (fields and yards)
  • Livestock and pet waste
  • Septic systems

The Source of the Problem

Once a waterbody has an excess of nutrients, the problem cannot be fixed overnight. Nutrients must be removed mechanically and/or allowed to be reduced naturally through internal cycling, while limiting the sources of nutrients in the watershed. Several North Dakota lakes have hypolimnetic drawdown systems that remove nutrient-rich water from the bottom of the lake. These systems can be effective at removing nutrients, but they do not address the nutrient sources.

What Can You Do?

Everyone plays a part in feeding the algae, from how you fertilize your lawn to the timing of fertilizing a 160-acre field, to whether or not you pick up your pet's waste, to the proper management of livestock waste. Tips to reduce nutrients from entering runoff to our surface waters:

  • Sample the soil in your yard before you fertilize.
  • Leave your grass clippings on the lawn - they give nitrogen back to the lawn.
  • If you do need to fertilize, use only the recommended amount of product and keep it off sidewalks and other hard surfaces.
  • Use field soil samples to calculate a nutrient budget for your crops.
  • Complete a comprehensive nutrient management plan for your farm.
  • Sample manure before applying it to the soil to ensure it is applied at the correct agronomic rate.

More Information

NDSU Extension Ag Article - June 2016

Livestock Water Testing Guidelines

ND Game & Fish Department

Centers for Disease Control

Water Quality Division Employee Email List (click to expand)

Last Name First Name E-Mail Address Program Phone
Anderson Carl cjanders@nd.gov WQ Ground Water Monitoring 701-328-5213
Becker Sarah WQ Spill Investigation 701-328-9151
Brazil Emily ebrazil@nd.gov WQ Watershed Management 701-328-5296
Delzer Alexis adelzer@nd.gov WQ NDPDES Permitting 701-328-5282
Espe Brady bespe@nd.gov WQ NDPDES Permitting 701-328-5228
Gilley Cameron cgilley@nd.gov WQ NDPDES Permitting 701-328-5210
Gleich Casey ctGleich@nd.gov WQ Ground Water Monitoring 701-328-4164
Gross Joe jlgross@nd.gov WQ Watershed Management 701-328-5292
Grossman Dallas dgrossma@nd.gov WQ NDPDES Permitting 701-328-5242
Hanson Lawrence lawrence.hanson@nd.gov WQ NDPDES Permitting 701-328-5291
Haroldson Marty mharolds@nd.gov WQ NDPDES Permitting 701-328-5234
Harrison Kylee kharrison@nd.gov WQ NDPDES Permitting 701-328-5187
Hite Nicole nhite@nd.gov WQ Spill Investigation 701-328-1676
Houle Brian bHoule@nd.gov WQ Watershed Management 701-328-5193
Hulst Annelise ahulst@nd.gov WQ Watershed Management 701-328-1377
Joynt Emily eJoynt@nd.gov WQ Watershed Management 701-328-5239
Kaiser Don dkaiser@nd.gov WQ Spill Investigation 701-328-5151
Kritzberger Ryan rKritzberger@nd.gov WQ Ground Water Monitoring 701-328-9035
Kruske Montana mkruske@nd.gov WQ NDPDES Permitting 701-328-5172
McCauley Jenna Jenna.McCauley@nd.gov WQ Watershed Management
McGee Julia jmcgee@nd.gov WQ Watershed Management 701-328-1380
Miller Meridith meridith.miller@nd.gov WQ Watershed Management 701-328-5166
Nelson Amber amjnelson@nd.gov Water Quality Division 701-328-5210
Novak Emilee ejnovak@nd.gov WQ Watershed Management 701-328-5240
Olson Jaxsyn jaxsyn.olson@nd.gov WQ Watershed Management 701-328-1382
Rockeman Karl krockema@nd.gov Water Quality Division 701-328-5225
Schick McKenzie mschick@nd.gov WQ Watershed Management 701-328-5288
Schiwal Alyssa aschiwal@nd.gov WQ Ground Water Monitoring 701-328-5159
Schuett Patrick pschuett@nd.gov WQ NDPDES Permitting 701-328-5235
Stockdill Scott sjstockdill@nd.gov WQ Spill Investigation 701-328-5241
Strommen Rachel rstrommen@nd.gov WQ NDPDES Permitting 701-328-5244
Suess Bill bsuess@nd.gov WQ Spill Investigation 701-328-5216
Suggs Shannon ssuggs@nd.gov WQ Ground Water Monitoring 701-328-6409
Waldron Feld Sarah sfeld@nd.gov WQ NDPDES Permitting 701-328-5237
Wallery Paige pWallery@nd.gov WQ Spill Investigation 701-328-5243
Wax Peter pwax@nd.gov WQ Special Projects 701-328-5268
Wert Joshua jewert@nd.gov WQ Watershed Management 701-328-5214
Wirth Cherreka cwirth@nd.gov WQ Watershed Management 701-328-9166
Woutat Tanner twoutat@nd.gov WQ Ground Water Monitoring 701-328-5233