ST. PAULS — Robeson County’s retiring director of Solid Waste estimates that a new system to treat and dispose of leachate generated at the county’s landfill in St. Pauls will save Robeson County as much as $430,000 a year.
Edge said that leachate, which is defined as any water that comes in contact with waste, is currently being transported and disposed of at the waste water treatment plant in Lumberton at a cost of $500,000 a year. About 7.5 million gallons of leachate is generated at the landfill annually, Edge said.
The Robeson County Board of Commissioners last week authorized $305,000 to purchase, construct and operate an aerosolization system that will allow the watery leachate and any solids it may contain to be treated and disposed of at the landfill.
Edge said that there are two similar systems that the county is considering to purchase and install at the landfill. He said the $305,000 is the overall cost of a system purchased and installed from American Evaporation and Irrigation, a company located in Cornelius. According to Edge, the breakdown of the cost is $65,000 for equipment purchase; $120,000 for installation of related infrastructure; and a $120,000 fee the company charges annually for the use of the system.
Edge described the aerosolization system as “simple and easy” to operate and maintain. He said the leachate that has gathered at the bottom of the landfill is pumped by two 150-gallon-per-minute pumps to a set of nozzles. It passes through the nozzles, where it turns into a mist and evaporates.
“Any solids will fall out onto the ground and can be placed back into the landfill,” said Edge.
Edge called the purchase and use of an aerosolization system a “significant cost savings” over a reverse osmosis system. A reverse osmosis system, which pushes water through a high pressure filtration system resulting in a sterile water discharge, had been discussed by county officials earlier this year.
“The purchase and installation of a reverse osmosis system would have been about $2.1 million, plus ongoing maintenance charges,” Edge said.
Edge said that the county is currently paying almost 8 cents per gallon to transport and dispose of leachate at the waste water treatment plant in Lumberton.
“If we use an aerosolization system the cost of equipment purchase, installation and operation cost will be about 1.5 cents per gallon.” said Edge. “…I believe that is a good cost savings for the county. We want the best investment for our future operational costs.”
Edge’s last day as director of Solid Waste for the county is Wednesday.
Bob Shiles can be reached at 910-416-5165.