COLUMBUS, Ohio — An alum treatment will be applied this spring over the entire area of Grand Lake St. Marys.

The alum binds phosphorous – which contributes to harmful algal blooms – to improve water quality, said Ohio Department of Natural Resources (ODNR) spokeswoman Bethany McCorkle.

Grand Lake St. Marys is a 13,500-acre lake in western Ohio.

Last year’s alum treatment was applied in June to more than 4,900 acres in the center of the lake and removed 56 percent of the phosphorous from the treated area, McCorkle said. The lake is already showing signs of improvement after this light application.

“It is our hope that since the treatment is being applied two months sooner than last year, that the phosphorous will bind to the alum more effectively and improve the water quality,” McCorkle said.

“This is just one way we are working to improve water quality at (Grand Lake St. Marys).”

The 2012 funding for the alum treatments will total $5 million and includes funding from the Water Pollution Control Loan Fund administered through the Ohio Environmental Protection Agency (EPA), and the Distressed Watershed Loan Program administered through the Ohio Water Development Authority, McCorkle said.

The ODNR is working collaboratively with the Ohio EPA to improve the water quality at the lake.

Through dredging in 2011, approximately 272,000 cubic yards of sediment were removed from the lake, McCorkle said.

This quadrupled the amount of cubic yards removed, compared to the last two years.

ODNR’s State Parks and Division of Wildlife also removed nearly 14 tons of rough fish from Grand Lake St. Marys last year, she said.

An additional four tons were removed during a carp derby planned by the Lake Restoration Commission. Rough fish stir up sediment and contribute to phosphorous-related problems.

 “We are committed to improving the water quality at (Grand Lake St. Marys),” said ODNR Director James Zehringer.

“A healthy and thriving lake will not only benefit the residents of Mercer and Auglaize counties, but this improvement will benefit all Ohioans.”