Check out Nancy Allen's article published in The Daily Standard, which discusses the current toxin levels in Grand Lake St. Marys. Article highlights include:

  • Average monthly algae toxin levels between Memorial Day and Labor Day in 2011, 2012 and 2013 show an increase every month except July, when the level fell slightly. 
  • Despite the readings, a state official said the lake is getting better.
  • This is the fifth consecutive year the state has placed a water advisory on Grand Lake due to unsafe levels of toxins produced by blue-green algae, also known as cyanobacteria. The advisory is posted when microcystin toxins exceed 6 parts per billion. The elderly, very young and people with compromised immune systems are told not to swim or wade in the water.
  • Between 2011 and 2013, average toxin levels ranged from a low of 11 ppb in May 2011 to a high of 90.3 ppb in May 2013. The only month the average monthly toxin level dropped was in July 2012 and July 2013 when it went from 36.2 ppb to 29.1 ppb.
  • Tests done on water leaving a treatment train on Prairie Creek showed significant reductions in nitrogen and phosphorous, nutrients that feed the blue-green algae. The treatment train diverts a small amount of water from the creek, funnels it through a series of manmade wetlands and treats it with alum, a chemical that deactivates phosphorous – the algae's favorite food source – before emptying into the lake.
  • Milt Miller, manager of the Lake Restoration Commission, said the lake looked good this summer because there were fewer algae blooms that produced surface scums.
  • Algae toxin levels and state water bodies with advisories due to algae toxins can be viewed on Ohio EPA's website at