Ohio lake cleanup calls for alum treatment

St. Marys, Ohio-Alum treatment has been given the go-ahead, along with efforts to reduce phosphorus runoff from agriculture and other sources, to eliminate infestation of blue-green algae that has closed popular Grand Lake St. Marys to swimming and boating. Gov. Ted Strickland announced that the state is acting on the recommendations contained in a study report by Tetra Tech Inc. that found the lake can be successfully treated with alum, which has been used and documented to inactivate sediment phosphorus in at least 150 lakes in the world. The report, commissioned by the Ohio EPA, suggests closing off two lagoons to test the effectiveness of the chemical compound, which would bond with phosphorous and sink it to the bottom of the lake. In addition, the state will require changes in manure hauling practices, limit phosphorus discharges from wastewater treatment plants within the watershed, and educate local homeowners on septic systems and lawn management practices. The Ohio Department of Natural Resources will seek legislative support for additional state regulatory authority that would restrict manure application during the winter and require farms with more than 350 tons of manure annually to develop a nutrient management plan. “The department understands the seriousness of this problem and stands ready to help the local community in any way possible,” said Ohio Department of Agriculture Director Robert Boggs. “We are hopeful that the algae pilot project, funded by the department, will provide positive impacts to the region.” The alum demonstration sites will be chosen this month, with actual treatment targeted to begin in September. Whole-lake application will only be considered following the completion of the demonstration projects. The plan also recommends reviewing the current small-scale algae flipping pilot project currently underway at the lake to determine if a larger-scale project is possible. The term “flipping” refers to the use of silica to reduce harmful blue-green algae by providing preferential growth environment for diatoms or another type algae by dosing the water column with non-toxic, benign silica (SiO2), which theoretically permits the diatoms to outcompete the blue-green algae.