The deputy director of the Ohio Department of Natural Resources Saturday morning gave members of a local lake group an update regarding an alum treatment for Grand Lake St. Marys.

Glen Cobb, who served as park manager of Grand Lake St. Marys State Park from 1991 to 1999, spoke to members of the Lake Improvement Association about a modification of the large-scale alum treatment initially slated to take place next week. Cobb said a variety of issues, mainly Mother Nature, caused officials to re-assess the plan. The initial large-scale treatment was to include a light alum dose to approximately 12,250 acres of the lake. A second, higher dose of alum was to be applied to 4,900 acres of the lake within the original 12,250 acres. Now, officials plan to treat the 4,900 acres of the lake with the higher dose because of its elevated levels of phosphorus.

“The top priority for me is Grand Lake St. Marys,” Cobb said, noting the plan to heal the lake includes dredging, alum, rough fish removal and other avenues of water purification.

Cobb said the modification of the alum is a result of an increase in biomass within the lake. Heavy rains during late winter and early spring also caused lake levels to increase.

“We’ve been paying attention to what’s going in the lake,” Cobb said. “So instead of doing the entire lake in the shallow areas with a light treatment, we are going to hold off on that. The reason is the consultant we have on board has told us, based on what he’s seen presently, the concern is if we apply that alum now in the shallower water and when it binds up that phosphorus, and starves that algae and that algae starts to decay and eats up that dissolves oxygen — he’s concerns about a massive fish kill.”

The altered plan has an estimated cost of $3.7 million — compared to the $5 million of the initially proposed plan. Cobb said the leftover money could be rolled over to next year for a treatment in the spring.

“That is when the best time is to apply alum,” Cobb said. “Now, it will be the mid-lake section and that will be at a higher dose.”

Cobb said he could not promise the absence of a fish kill with the altered project. However, he said he believes it’s the best course of action to heal the lake.

Cobb also mentioned the possibility of re-examining the spillway. He held off on specifics because of pending litigation with property owners.

“We will look at this,” Cobb said. “We know this is something that you want. This is not falling on deaf ears.”

In terms of dredging, Cobb noted there are now three dredges pulling material from the bottom of Grand Lake St. Marys. A new dredge also will soon be ordered and is expected to be delivered in the fall.

“We will be dredging longer into the season,” Cobb said. “We are certainly out there earlier than in years past and we are working more days. We are looking to continue our efforts in dredging.”

Cobb said he would like to increase dredging hours as well as the creation of inlake dredge material relocation areas (DMRAs). Additional shoreline protection projects also will be in the future.  

Cobb also touted the rough fish removal project currently going on at the lake. The state unsuccessfully put the project out for bids. However workers have been dedicated solely to the task of removing the rough fish.

“Right now, we have four nets,” Cobb said. “We are looking at way to increase that. We are looking at ways to increase the rough fish we are bringing out.”


By Mike Burkholder, The Evening Leader