COVINGTON - The city of Covington has found a creative way to save more than $60,000 per year by hauling biosolids generated from the wastewater treatment plant to a local farm for land application.
Currently, the city hauls biosolids, also called sludge, to a landfill in Winder, at a cost of $40 per ton.
But now it will be hauled to agricultural land and spread to help crop production. As a result, the city will save abut $62,000 annually for the next three years, said David Croom, manager of the city's Water Reclamation Division.
Farmer Lewis Banks was the lowest of five bidders, charging the city $15 per ton to haul the matter to his property.
The City Council approved a contract with Banks at its Monday night meeting.
"We won't sign the contract until the EPD says, 'You're good to go,'" Croom said, adding that there are numerous requirements that must be met through the Georgia Environmental Protection Division before the biosolids can be spread.
Slope grade, type of crop, the amount of the material to be spread and whether there are cattle or animals on the property must all be addressed, he said.
The water reclamation facility off Bypass Road produces an estimated 3,000 wet tons of residual solids per year.
Biosolids are generated in the wastewater treatment process and are the organic byproduct of biodegradation. The organisms in the sludge are not disease-causing agents, but are the decomposer class of microorganisms that are able to biodegrade organic waste material.
In treatment, the sludge is separated from the wastewater in a clarifier. Most of the settled sludge is returned to the head of the treatment plant to be blended with more incoming sewage, but a small portion is pumped to the digestion tanks for further treatment and stabilization. Further treatment prepares the biosolids to be land applied as a liquid slurry or as a semisolid cake.
"It comes out in cake form and it is spread like farmers spread chicken litter," Croom said.
The material can be beneficial to agricultural land because it contains most of the essential plant micronutrients in a balanced, organically bound package.
Croom said the EPD is generally in favor of land application of biosolids.
"They try to encourage it because it is beneficial," he said. "Why put it in the landfill when it could be a beneficial nutrient?"
Crystal Tatum can be reached at firstname.lastname@example.org.