Earl Duck, an AEP supervisor, left, and Warren Dick, an Ohio State University soil scientist, with gypsum.
Some of the dried sludge is used to make drywall for construction projects, but most of it gets dumped into landfills.
Gypsum is a mineral commonly used in plaster of Paris.Warren Dick, an Ohio State University soil scientist, says he has found another use for the gypsum — spreading it on farm fields to reduce the phosphorus that washes into waterways and feeds toxic algae.
“(Gypsum) binds with the phosphate in the soil,” Dick said. “It keeps phosphorus where you want it — in the field, where the plants can take it up and use it.”
It seems an unlikely solution. Power-plant emissions include arsenic, cadmium and other toxic metals. But power-plant officials say nearly all of those poisons are removed from smoke before scrubbers kick in.
“The gypsum is 95 percent pure,” said Mark Durbin, a spokesman for Akron-based FirstEnergy, which uses scrubbers at its W.H. Sammis plant along the Ohio River.Dick said he plans to test gypsum this year on about 30 farms in areas that drain into the Maumee River, the main conduit for phosphorus to reach Lake Erie.
Penn State University researchers found in 1999 that gypsum could cut farm-field phosphorus runoff in half.Eric Schaeffer of the Environmental Integrity Project, a group critical of power plants that is based in Washington, D.C., gave the process a conditional OK.
“The test data on gypsum is pretty good in terms of its being something that would have a low probability of harm,” said Schaeffer, who added that tests should be performed routinely to make sure toxin levels in gypsum remain low.
Lake Erie researchers say steep reductions in farm-field phosphorus runoff are needed to reduce toxic algae blooms and ensure the lake’s survival. State officials now promote voluntary measures to reduce farm runoff, but the Ohio Farm Bureau Federation recently sent Ohio farmers a letter warning them that state and federal regulations might come if voluntary measures aren’t embraced.
Also called cyanobacteria, the algae produce liver and nerve toxins that can sicken people and kill pets.
The algae also create an oxygen-depleted dead zone near the center of the lake where fish cannot survive.In 2011, the algae spread from Toledo to Cleveland, threatening the lake’s $10 billion-a-year tourism industry. Drought conditions kept last year’s bloom much smaller.
Melissa McHenry, spokeswoman for Columbus-based American Electric Power, said spreading gypsum on farm fields sounds intriguing. About 80 percent of the gypsum from AEP’s Cardinal plant on the Ohio River is shipped downriver to a West Virginia wallboard plant, she said. The rest goes to a company-owned landfill. The plant produced nearly 360,000 tons of the stuff in 2011.
One company, Chicago-based Gypsoil, already sells gypsum to western Ohio farms. The gypsum, trucked from Indiana power plants, contains sulfur and calcium, nutrients that can help grow crops and also encourage root growth, said Dave Schuurman, the chairman of Gypsoil’s parent company, Beneficial Reuse Management.
Dick said he hopes this year’s tests will show that gypsum can help Lake Erie
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