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Thank a Farmer—Eight SD Lakes Draw Poison Algae Warnings

The Department of Agriculture (and Natural Resources) and Game Fish and Parks put out a reminder last week of Harmful Algal Blooms in several South Dakota lakes. Algae on lakes doesn’t just smell bad; it can produce microcystin, toxins from the decay of blue-green algae that can mess up your liver and kill your dog.

DA(NR) says algae bloom usually in July through September in “nutrient-enriched” lakes. Such is the term we use for ag-industrial pollution in the form of poorly applied chemical fertilizer and uncontained cow poop as “nutrients” that “enrich” our public waters.

The green-and-gold medal for nutrient enrichment so far this year goes to Lake Mitchell, where, according to the state’s supercool interactive map of Harmful Algal Blooms, a July 11 water quality test found 365 micrograms per liter of microcystin. The maximum allowable level of microcystin is 8 micrograms per liter.

Lake Madison gets silver with 115 µg/L on 7/14, just edging out bronze-medalist Mina Lake, which posted 114 µg/L on 6/30.

Eight lakes have blown hot for microcystin this summer and earned Harmful Algal Bloom notices. Here’s the full list with test dates and date of HAB notice:

  1. Lake Mitchell: 365 µg/L (tested 7/11, notified 7/25)
  2. Lake Madison: 115 µg/L (7/14, 8/17)
  3. Mina Lake: 114 µg/L (6/30, 7/25)
  4. Lake Hendricks: 86 µg/L (7/15, 8/17)
  5. Lake Herman: 66.8 µg/L (8/18, 8/27)
  6. Beaver Lake: 18.7 µg/L (7/29, 8/9)
  7. Lake Traverse: 16.3 µg/L (7/15, 8/17)
  8. Lake Poinsett: 9.9 µg/L (8/22, 8/30)

Congratulations to Lake County on being the only county to win two Harmful Algal Bloom notices this summer! Be sure to thank your local providers of all that nutrient enrichment for making these special notices possible.


  1. kurtz 2021-09-14

    Throughout its history the US Army Corps of Engineers has had purview over water that flows into bodies that can support navigation and in 2014, through the US Environmental Protection Agency, the Obama White House moved to more closely identify the sources of non-point pollution. Despite a judge’s ruling EPA went forward with a new federal rule protecting small streams, tributaries and wetlands. The Waters of the United States legislation sought to give authority to the EPA to use some teeth to enforce the rights of people downstream to have clean water even from some sources that the US Geological Survey has already identified as impaired.

    In 2018 New Mexico’s Hector Balderas joined a bipartisan group of mostly western attorneys general that included Republicans Tim Fox of Montana and former South Dakota AG Marty Jackley in a lawsuit against the Trump Organization’s EPA. They argued EPA failed to promote a rule that would have forced hard rock mines to meet federal financial bond rules passed during the Obama years.

    Republican welfare ranchers and farmers are the real ecoterrorists who hate socialism unless they benefit from subsidies so desertification driven by livestock grazing and industrial agriculture has turned parts of the high plains and much of my home state of South Dakota into scorched earth.

    Columnist Alan Guebert says ethanol has plateaued: Farm Forum.

  2. ArloBlundt 2021-09-14

    Well…I’m surprised Poinsett was only 9.9 in August. I grew up around that Lake as my Grandpa had a cabin over by Stone Bridge and it bloomed every year with blue green algae. There is a diversion canal going into it which brings water in from the Big Sioux over in the northeast corner. Water quality has been a problem since the 50’s. In the 80’s, South Dakota and Minnesota joined in a project to identify non point farm pollution in the watershed (mostly farmers piling manure and other barnyard waste in “dry creeks” and draws.). A friend of mine worked a grunt job in Natural Resources and was assigned to “find sources of non point pollution and inform the landowner of possible legal action”. It was a hopeless task, he said. Some farmers were compliant and promised to adjust their practices, most ignored him, a few brought out shotguns. Obviously not much has happened in the last 40 years to address the problem.

  3. Black Hills Hermit 2021-09-14

    Seems like Madison might need that Missouri River water even sooner than thought. Build a new lake with a water-impermeable berm around it. Oh, that’s right! The municipal swimming pool, but it’s too small for boating and no fish.

  4. Porter Lansing 2021-09-14

    The Madison pool always had a brown ring around it.

    The girls on their team were very friendly and the guys were always joking around and fun, too.

    Watertown swim team swam against Madison more than any other team, due to proximity.

    Great memories of Madison.

    Kampeska’s better since the cattle don’t cool off, near Sandy Shores, anymore.

  5. Cory Allen Heidelberger Post author | 2021-09-14

    I never swam in the Madison pool. All my aquatic activities took place in good green Lake Herman. I think my liver is still OK.

    Maybe we should run the Lewis and Clark pipeline out to the Madison country club, open the spigot to full, and flush out the whole Herman-Madison watershed!

  6. grudznick 2021-09-14

    You, Mr. H, are a lilly-pad moss-beast.

  7. R. Kolbe 2021-09-14

    Note lakes are
    Near population centers
    Have housing around shore

    Both these entities like good green lawns.

    Would farmers fertilize crops to the extent
    Homeowners fertilize lawns???

  8. kurtz 2021-09-14

    The Lewis and Clark water system enables ecocide. Instead of empowering communities to harvest snowmelt and rainwater rural communities continue to be dependent on politicians who exploit need.

    For every 1” of rain and 1,000 square feet of surface (roof, driveway, etc), about 620 gallons of fresh water are generated.

  9. grudznick 2021-09-14

    Indeed, Lar. That’s why I follow your teachings of putting ice cream buckets under the downspouts.

  10. kurtz 2021-09-14

    Lake Kampeska, Lake Poinsett, Lake Mitchell, Lake Thompson and other non-meandered bodies of water will continue to suffer the effects of human-caused climate distortions but disaster declarations are how Republicans who preach small gubmint fund crumbling infrastructure in red states. Recall Rep. Kristi Noem repeatedly voted against disaster aid after Hurricane Sandy and other climate related catastrophes but she doesn’t respect self-reliance because she’s wedded to moral hazard.

  11. O 2021-09-14

    It is stories like this that make me sneer at the “America’s conservationists” commercials applauding SD farmers.

  12. Cory Allen Heidelberger Post author | 2021-09-14

    When I was in Lake County, I recall hearing from a well-connected expert on water quality in the area that in Lake Madison, residential sources like lawn fertilizer accounted for maybe 15% of the pollution in the lake. Agricultural sources counted for 80+ percent. The total acreage that homeowners occupy and fertilize alongside the lakes is minuscule compared to the tens of thousands of acres all throughout the watershed that farmers own and fertilize and run cattle on. I welcome more accurate calculations and data from the Lake County Equalization Office, but I’m going to take a wild guess and say that the total residential acreage around Lake Madison and Lake Herman put together would still be smaller than some of the individual farms in Lake County. I would also welcome landowners to tell us the actual amount of lawn fertilizer they buy versus the actual amount of farm fertilizer sold in the county and the amount of fertilizer applied per acre for each use. I can tell you that, as far as I know, my dad, who has owned a fair chunk of residential land alongside Lake Herman for 45 years, has never put a drop of fertilizer on his yard.

  13. ArloBlundt 2021-09-14

    Well…I’m a little puzzled by the high numbers at Lake Mitchell…while farm runoff is probably a contributor I suspect leaking septic systems or lack of septic system in residential developments around the lake. Lake Mitchell is a damming of Firesteel Creek which rises high on the Wessington Hills plateau just north of Wessington Springs. It flows south by southwest through Aurora County before turning to the east to join the James River above Mitchell. It is dammed not far from its mouth. It flows through corn and cattle country and is dammed in a couple places before Lake Mitchell which should allow some fall out of accumulated run off. While certainly not a pristine ag area it is not as intensively farmed as other areas of eastern South Dakota. While we like to blame cows and farmers I think the remarkably high numbers in Lake Mitchell might be traceable to good old human sewage.

  14. Porter Lansing 2021-09-14

    Funny you should bring up what disease Lake Herman causes to a human liver.
    I know the amount of alcohol consumed at Schoenbeck’s lake cabin would take out a dozen Irishmen’s organs.
    My family would stay at Kampeska in the summer and being on the swim team I would practice flip turns against a board on the legs of the dock.
    Every summer, about the time of the state meet in Aberdeen, I’d come down with a severely debilitating ear infection. Sometimes, both ears.
    After several years, Mom took me to a different Doctor, who lived out at the lake.
    He immediately recognized the problem, as his kids had the same infection.
    Dirty, algae infested, water twisted deep into my ear canal from flipping under the surface.
    I’ve not gotten into Kampeska in fifty five years and won’t unless the beach is on fire.

  15. John 2021-09-15

    Outstanding note and comments. Thanks all.
    -consider that lakeside residents plant native buffalo grass. It requires no fertilizer, no water, no mowing. Lakeside HOAs, etc., should mandate it, or at least mandate no fertilizer ordinances.

    -consider that Arlo is likely correct concerning Lake Mitchell’s problem is exacerbated by lake residences and upstream residences with no and/or faulty septic systems. Modern tracking can easily link pollution back to specific residences. Consider that about a decade, or more ago, the Minnesota Pollution Control Agency began exhaustive work to clean up Minnesota lakes and rivers. The MPCA was shocked at the number of rural, lakeside, and river side residences directly discharged into the waters of the state. When SD’s Pennington County tried to begin septic system inspections upstream of the Rapid City water supply – the ‘right to polluters’ whining set off the Richter scale. Point being, the selfish, anti-social polluters know who they are.
    From 2005:
    From 2019:

    -SD will rue the day when it combined DENR with the pollution-friendly Ag department. Perhaps it may require the feds to re-assume regulatory control of managing SD waters and watersheds – to save South Dakota from itself.

  16. ArloBlundt 2021-09-15

    John-I have no evidence that the extremely high count of mycrocystin in Lake Mitchell is contributed to by faulty septic systems but that was the scenario at a 1,000 acre lake in northern Wisconsin where we have a home. The lake had been polluted by logging and a cheese factory that dumped whey directly into the lake back in the 20’s. It had been developed residentially in the years after WWII with first seasonal cabins and then, as time went on the cabins were torn down and rather elaborate houses were built on the lots.The village next to the lake put in a sewer system and it extended it partially around the lake. the Lake remained murky, though water quality improved noticably, and it still developed algae and turned over during the summer months. The DNR identified septic pollution as a primary cause as well as heavy use of lawn fertilizer and a lack of buffer zones in residential portions of the Lake. The village offered to extend the sewer around the lake. The lake property owners on the two thirds of the lake without the sewer had a fit about this, citing high costs for sewer hookup and invasion of their freedom and landower rights as in the Black Hills/Rapid City controversy. After intervention through the courts, the DNR conducted dye tests on all the non compliant residences. Over 40% of the residences had sewage leaking into the lake. On further investigation, it was found that the septic systems of these home were comprised of 55 gallon drums, mostly rotted out, buried in the sand, a common practice by cabin owners in the 40’s and 50’s. The cabins had now become multi bedroom and bath year round houses. The septics had never been replaced.By this time, the grant the village had been granted to extend the sewer had expired and by order of the court the homeowners had to put in very expensive, high end, septic systems at much greater cost. The water in the lake is now exceptionally clear all summer long.

  17. kurtz 2021-09-15

    It’s not just Lake Mitchell.

    By the most recent data, with the highest number in the US, 29 lakes in South Dakota are at risk mostly because of poor agricultural practices.

    And where is Mitchell native Howdy Doody Dusty Johnson? Raising money for his own self-gratification, of course.

  18. kurtz 2021-09-15

    According to Bill Janklow’s idea of public radio South Dakota needs the millions in the Democratic infrastructure bill that no Republicans in the congressional delegation even support. Bridges are decrepit, clean water is at risk and GOP timidity is on display! But expect all of it to dissolve and they all crash back into the center after the election.


  19. John 2021-09-15

    Arlo, yep. Thanks for anecdotally supporting my hunch.

    kutz: excellent point – Howdy Doody Dusty Johnson is unable, unwilling to clean-up his back yard. He’s such a tool.

  20. grudznick 2021-09-15

    Drain Lake of Mitchell. Cut the number of counties down to 35. And by the golly of all gollies, stomp out “public radio” for once and for all. I predict law bills coming this year to defund them entirely.

  21. grudznick 2021-09-15

    Plus we need to get back to rewilding the west.

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