ODNR issues water quality warnings at Grand Lake St. Marys

·2 min read

May 19—ST. MARYS — Public health advisories have been issued by the Ohio Department of Natural Resources for various beaches at Grand Lake St. Marys due to algal bloom toxins that have plagued the lake in recent years.

Advisories were issued May 15 for beaches identified as "Main West," "Windy Point," "Main East" and "Camp." All four beaches have been posted with warnings urging the public to avoid all contact with the water and that swimming and wading are not recommended. Pets should be kept away from the water, signs say.

Donna Grube, executive director of the Grand Lake Region Visitors Center, said the beaches are not "closed" in the truest sense of the word.

"People can do whatever they're comfortable with," Grube said. "But we don't beat around the bush and we tell visitors these (warnings) are what the state says."

After a couple of years of reduced toxin levels, Grube said a lack of significant ice cover this winter is believed to have contributed to higher-than-expected readings.

"The ice kills the algae over the winter but this year there was not a sustained cover of ice for weeks and weeks," she said. "It's disappointing, but Mother Nature is pretty much in charge."

The state's recreational advisory threshold for microcystin is 8 parts per billion. The levels reported at beaches earlier this week were 21.9 ppb at Windy Point, 16.1 ppb at main west, 22.7 ppb at Main East and 17.6 ppb at the state park campground, according to ODH's Ohio's Beach Water Quality & Advisories website.

It was almost exactly this time last year when similar advisories were posted at the lake that spans Auglaize and Mercer counties when toxin levels caused by green algae rose above the 8-parts-per-billion threshold.

For water-related activities such as swimming and jet-skiing, Grube suggested that visitors to the lake simply wash themselves off after exiting the water. Fishing is safe, she said, and there is no advisory against eating fish from the lake.

Algae problems in Grand Lake St. Marys first arose in 2010 "and we've been dealing with it on and off for the last 13 years," Grube said.