St. Marys, Ohio-Technical experts are advising that Grand Lake St. Marys in western Ohio, which has serious algae growth and associated toxins and has been declared unsafe for swimming, can be successfully treated with alum. According to the technical report compiled for the state by Tetra Tech Inc., alum, which is popularly known as an aftershave or for treating small shaving cuts, has been used and documented to inactivate sediment phosphorus in at least 150 lakes in the world. Tetra Tech reported that most of the lakes treated have been in Minnesota, Florida, Washington, and Wisconsin. The majority were smaller than Grand Lake, but most treatments were successful if dosed properly. Dina Pierce, spokeswoman for the Ohio Environmental Protection Agency, which commissioned the Tetra Tech evaluation, said no decision has been made as yet to proceed with an alum demonstration. The report 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. Tetra Tech estimates the cost of the demonstration at between $150,000-$300,000, plus another $120,000 for a barrier to separate the treatment area from the main lake. If the tests work the entire lake could be treated in the next year, with treatments beginning as early as this fall, according to the report.
Transparency Across the Fertilizer Value-Chain