Health advisories up, but St. Marys holding its own
St. Marys, Ohio — Things are returning to normal at Grand Lake St. Marys despite the health advisory warnings posted on May 24. The advisory was not a “no-contact” advisory, as was posted in 2010. It did not affect fishing or boating.
Fish must be washed but are safe to eat and the fishing has been great, say DNR officials.
“The first water quality tests came back and because of those tests we are posting an advisory that seniors, children, and folks with compromised immune systems should stay out of the water,” said Mark Bruce, a DNR spokesman.
In addition to the great fishing, this has been an active boating season and businesses are saying that things are improving, Bruce said. State, federal, and local agencies have worked together to improve water quality. Yet public health is paramount and the warnings must be posted, Bruce said.
More serious “no-contact” warnings were posted when the lake was hit with a massive blue-green algae explosion in 2010. Unfortunately, the problem superseded the science, said Milt Miller, chairman of the GLSM Restoration
Commission. For all practical purposes, “they shut down our lake,” he said.
The World Health Organization said that there should be no more than 20 parts per million of the toxins in the water, Miller said. The next spring the Ohio Environmental Pollution Agency (EPA) dropped that to six parts per million.
“They really dropped it,” Miller said recently. “Our contention is that six parts per million is so small that we speculate if other lakes were measured, they’re probably there already too, but nobody knows it.”
After that 2010 algae explosion, Miller and others formed the Grand Lake Restoration Commission. They raised $660,000 in one year, Miller said. Part of the funds went to professional scientists at Battelle Institute and several think tanks to figure out how to solve the problem. Many steps have been taken.
The DNR instituted a nutrient management plan in the watershed, Bruce said. One hundred fifty-eight farms in the watershed met the criteria to have nutrient management plans; 156 have complied and the DNR is working with the remaining two farms.
Dredging, which removes nutrient runoffs from decades past, has been drastically increased, Bruce said. Last year a record 289,000 cubic yards of dirt were removed from the lake. In 2013 the goal is 300,000 cubic yards. By comparison, in 2007 and 2008, 65,000 cubic yards were removed a year.
Since 2011, 44 tons of rough fish have been removed from the lake, Bruce said. The rough fish are big and they stir up the lake sediment, which then stirs up the nutrients and that’s what the algae feed on.
“When we first came up with this idea we were laughed at by the public because they did not see its merit but the reality is, that concept came to us from the Battelle Institute based on their studies of other lakes,” Miller said. “Our lake is heavily lopsided toward the rough fish, carp, sheepshead, and shad, because of the degraded water conditions.”
Those fish are rooters, he said. They go along the lake bottom, fluffing the phosphorous back up into the water column. They uproot the needed aquatic vegetation. Plus they’re scavengers by nature; their excrement contains a lot of phosphorous and, finally, when they die, their body mass is heavily laced with phosphorous. The commission is seeking companies that would harvest these fish commercially.
The Prairie Creek Treatment Train is a concept developed by the GLSM commission. It works like a kidney for the lake, Bruce said. A lift station pumps water from Prairie Creek, one of the lake’s eight tributaries. It goes through an alum dosing and into 40-acre constructed wetlands. The treatment train is a pilot project. If successful, the commission hopes to receive grants to build one on every tributary.
“The folks at the lake are telling me that water is coming into the treatment train chocolate brown and when it is getting put back into the lake it is crystal clear,” Bruce said. “It is filtering out all of the sediment, all of the nutrients, and that is keeping it from getting into the lake.”
Added Miller: “The thing is, when strangers come to our lake they are expecting to see this foul smelling polluted lake and it is simply not that. It is a wonderful asset.”