Grand Lake Sign

Grand Lake St. Marys officials were given the go-ahead to remove water quality advisory signs around the lake on Wednesday. The signs have been in place since 2009.

In 2009, signs went up on Grand Lake St. Marys that signaled toxic algae blooming in the lake and warned against coming in contact with the water.

On Wednesday, those signs were removed by the state as Grand Lake is no longer under a state water advisory.

“It’s just a complete effort,” said Lake Improvement Association President Keith Westrick. “The numbers have been super this year.”

The numbers Westrick is referring to are the microcystin levels, which have been below 0.3 milligrams per liter all year, similar to levels at Indian Lake and other Ohio waterways.

Back in 2009 when the Ohio Environmental Protection Agency began testing the water in Grand Lake, the microcystin levels were between the ranges of 55 to 73 mg/L.

The microcystin toxins, causes by blue-green algae, can cause health problems for individuals including diarrhea and vomiting if ingested and skin rashes, sore throats, runny noses and allergic reactions.

The World Health Organization has set the human contact threshold level at 20 mg/L.

Efforts from lake officials have been ongoing for the last 12 years, constantly running tests and implementing other things like new wetlands, treatment trains and dredging.

Theresa Dirksen, the agriculture and natural resources director for Mercer County, said constant efforts and other factors have attributed to the lake seeing such low toxin levels currently.

To read the full story, pick up a copy of Friday's edition of The Evening Leader.

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