Farmers may bear the brunt of an Ohio EPA “impaired” designation for the western basin of Lake Erie under the Clean Water Act, which could put restrictions on fertilizer and manure that lead to annual algal blooms.

The agency announced the designation March 22 in a draft report that for the first time lists the lake’s western waters as falling short of federal and state water quality goals. Once the U.S. Environmental Protection Agency makes such a designation, the Clean Water Act requires a state to reduce pollution.

The move could pave the way for further regulation of farming operations in northern Ohio.

Environmentalists have long sought stricter limits on fertilizer and manure as well as other ways to reduce phosphorus from agriculture reaching Lake Erie. Due in part to phosphorus pollution, the lake has experienced large blue-green algal blooms, which occasionally have made water undrinkable for 500,000 Toledo-area citizens.

“The impairment finding is the key first step, but it’s not the end,” Howard Learner, executive director of the Environmental Law & Policy Center, told Bloomberg Environment March 22. “The necessary next steps under the Clean Water Act and common sense are for the Ohio EPA to set forth enforceable standards and protections that will result in less agricultural runoff.”

The center is suing the federal EPA to designate the lake’s western basin as “impaired” without state input. The suit will go forward despite Ohio’s announcement, Learner said.

“Our biggest worry is that the public may get the impression that this is the silver bullet that will eliminate harmful algal blooms. It won’t,” Adam Sharp, executive vice president of Ohio Farm Bureau said in a March 22 statement. The group estimates reduction steps will take between five and seven years.

The Ohio Farm Bureau has been a proponent of voluntary methods for reducing runoff, which was largely the stance taken by Ohio until now. The bureau works with several other organizations to create nutrient management plans to help farms curtail runoff.

“We firmly believe that productive farming and clean water are not mutually exclusive,” Sharp said.