Saturday, April 9th, 2011
By Nancy Allen
All alum test sites treated
Areas will be monitored 30 days; results will determine future treatments
GRAND LAKE - The water in the lagoon at Grand Lake St. Marys State Park campground was strikingly clear Friday afternoon - just days after it received a concoction of granular hydrogen peroxide, liquid alum and sodium aluminate.
The lagoon is one of three sites on Grand Lake the state is testing the use of alum to help lessen toxic algae blooms. Clear water also was reported at a Windy Point test site.
Aluminum sulfate (alum) applications were finished Friday. Ohio EPA officials now will monitor the sites for 30 days, taking water and sediment samples to determine levels of total phosphorous, nitrogen, dissolved oxygen and ph.
"We're pretty pleased and happy with how the contractor made the application," Scott Fletcher, spokesman with the Ohio Department of Natural Resources (ODNR), said Friday. "It was very meticulous and focused."
Alum deactivates phosphorous, the main food source of the lake's toxic blue-green algae that caused massive blooms on the lake and almost shut it down last summer. Hydrogen peroxide strips phosphorous from organic matter, sediment and algae, allowing the alum to bind to more of the phosphorous.
On Tuesday, a channel at Kozy Marina received 1,850 pounds of granular aluminum, which also contained a buffering agent meant to reduce ph fluctuations that could stress fish. The state wanted to test granular alum's effectiveness in areas with little water movement.
On Wednesday, 1,400 pounds of granular hydrogen peroxide was applied to the state park campground lagoon, followed the next day by 6,800 gallons of liquid alum and 3,400 gallons of sodium aluminate, a ph buffer.
On Friday, the east channel at Windy Point was treated with 5,200 gallons of alum and 2,600 gallons of sodium aluminate.
State officials said a large die off of shad at the Windy Point site was expected. Shad are an abundant rough fish in the lake that are sensitive to temperature fluctuations and environmental changes, Fletcher said.
"We were watching it really closely, and there was about 1,000 fish, all shad, that died," he said. "I don't think people will be concerned. It's nowhere the number you would see (dead) with a large algae-related fish kill."
Fletcher said the shad likely were more susceptible to stress from the treatments because shad stay on the water bottom, where the alum-treated phosphorous clumps together and drops.
Results from the three test sites will be used to determine dosage amounts for future, large-scale treatments on the lake. The state-funded test cost $51,521, well below the $95,000 estimate.
Officials are hoping for better results than the first alum tests done last summer. Only liquid alum was used, which produced some phosphorous reductions, but not as much as state officials had hoped. Those analyzing the results recommended a second test be done during cooler temperatures with a hydrogen peroxide pretreatment to better help the alum work.
A whole-lake treatment is set for May 16. Due to limited funding, the state will only apply about 18 percent of the alum needed to effectively treat the 13,500-acre lake. Officials hope it will be enough to limit algae blooms to the point that no advisories are issued or at least so people can boat safely.
The state is planning to pay for the treatment with a $5 million loan, which would not need to be repaid, from the Ohio EPA Water Pollution Control Loan Fund.
Ongoing, small-dosed alum treatments will be needed in the lake for some years until conservation fixes on the land start reducing phosphorous runoff into the lake. Alum is being used as a short-term solution.
"I think we are all very excited and hopeful," Milt Miller, a member of the local volunteer Lake Restoration Commission, said Friday. "We're hopeful that the $5 million will be enough to keep the algae and toxins down to a level that the lake can be enjoyed by everyone."
To see photos of the water and find directions to the test sites go to www.lakeimprovement.com/alum-tests-clear-water.
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