Oconee County reported a major spill at its Calls Creek wastewater treatment plant early Tuesday.
The spill sent an estimated 24,000 gallons of partially treated wastewater into the creek, a tributary of the Middle Oconee River, according to a public notice the county posted on its website.
An Oconee Water Resources Department worker discovered the spill at about 12:30 a.m. Tuesday. Following testing, county officials notified the state Environmental Protection Division and the Oconee County Environmental Health Department.
The cause isn’t yet determined, said Oconee County Commission Chairman John Daniell.
Oconee County Water Resources Director Wayne Haynie and other workers are conducting a forensic review to find out the cause, Daniell said.
“They’re going back and trying to figure it out,” Daniell said.
An “episode of peak flow” apparently washed solids out of one of the plant’s clarifiers, Haynie said. The flow was disinfected as usual by an ultraviolet light system, and the spill only added about five pounds of solids above the normal mass contained in 1 million gallons of wastewater flow, according to Haynie.
The recent cold spell has also affected plant operations, he said.
Workers have ampled waters downstream from the spill to test for pollutants.
The plant has been responsible for a number of spills in recent years. A series of major spills occurred in 2015, some estimated at more than 100,000 gallons of wastewater released into Calls Creek.
A consultant hired by the Oconee County Commission following the 2015 spills found numerous problems at the plant and at a smaller land application treatment plant. Commissioners replaced the plant’s operators, including the director of its utility department, now called the Water Resources Department..
The 2015 spills spurred county officials to begin planning an expansion of the Calls Creek plant, which was nearing its operating capacity. In the meantime, the county commission approved money to repair malfunctioning equipment at both the Calls Creek and Rocky Branch treatment plants.
Since then, spills large enough to require reporting to the state Environmental Protection Dvision have been fewer and smaller - one in 2016, one in 2017 before this week’s, Haynie said.
In February, the Oconee County Commission approved a $13.4 million expansion and upgrade of the plant, designed to bring its operating capacity from its current 667,000 gallons a day to 1.5 million gallons — enough to meet demand for wastewater treatment in the growing county until sometime in the 2020s, Haynie said at the time.
The spill is another demonstration of the need for the upgraded plant, Daniell said.
“Once we get the new plant, (the wastewater is) going to be a lot cleaner than it’s ever been,” he said.
The renovation and expansion project is scheduled to conclude this year.
County commissioners also approved a program of buying back wastewater allocations county officials sold developers before the recession of 2008, after Haynie discovered the county had sold more allocation reservations than it had capacity to fill.
Oconee government officials will sponsor an open house from 6 to 8 p.m. Tuesday on county water resources in the Oconee County Civic Center.