Local biosolids plant updates to meet demand, control smell
A $950,000 upgrade at the West Central Wisconsin Biosolids Facility will mean three things: Less breakdowns, more capacity and less odor, says plant Superintendent Sam Warp.
A search that took WCWBF commissioners to many plants in the United States and Europe ended ironically when they found the equipment they were looking for next door in St. Croix County, said Warp.
The major pieces of equipment, made by Schwing Bioset of Somerset, have been installed and are in operation.
"The equipment is built heavy duty for pumping sand and gravel," said Warp. "To pump something like this (sludge), it pumps it with ease."
The new equipment already has cut the ammonia odor released by the plant. Commissioners will now move to the task of adding an additional system to further reduce the smell, said Warp.
In 1996, 11 area communities banded together to build one plant to process the sludge from their wastewater treatment plants. Now, 23 cities and villages bring their sludge to the plant, located on the southeast side of Ellsworth.
Three employees operate the plant.
"That's kind of where the money saving comes in for the communities," said Warp.
"Everything that settles out is the sludge, and that's what they bring here," he said. The plant processes sludge from an area with a population of just over 75,000 residents.
As tanker trucks haul sludge to the plant, the heavy material is run through a centrifuge to remove even more of the water. At the plant, the material is then mixed with quick lime and held in a huge stainless steel tube at a temperature of 150 degrees for nearly two hours to destroy any pathogens.
Most of the resulting material is sold to Precision Ag Services for use on farm fields.
"They actually pay us for the product," said Warp. In turn, farmers pay Precision to spread the material on their fields.
"It's kind of a slow-release nitrogen," said Warp. Most of the farmers want the lime, but get the added benefit of a fertilizer, he said.
A lot of homeowners also come with trucks to lug out the material, he said.
The plant processes 9,000 tons a year.
"So if somebody wants a pickup load, that's not even a dent in it," said Warp.
For the complete story, see the May 27, 2009, print edition of the Pierce County Herald.