Oconee County late Tuesday reported its second major spill in less than a month from its Calls Creek wastewater treatment plant outside Watkinsville.
According to the county, an estimated 72,000 gallons of partially treated wastewater was released on Monday and Tuesday (Feb. 5 and 6) into Calls Creek from the plant, which is located at 1100 Durhams Mill Way, on the north side of Watkisville.
The county said it notified the Georgia EPD, which classifies the discharge as a major spill, and the Oconee County Environmental Health Department.
On Jan. 9, the county reported a major spill of an estimated 24,000 gallons of wastewater that exceeded permit limits for total suspended solids from the Calls Creek plant.
Excess Inflow Possible Explanation
The problem at the Calls Creek plant was identified by plant operators after lab analyses of effluent samples, according to the county’s Public Notice of the permit violation.
The excess releases were between 8 p.m. on Monday and 1 a.m. yesterday, according to the Notice.
The plant “appears” to have had peak flow rates of 1 million gallons per day or greater, exceeding the plant’s design hydraulic capacity, and upsetting sludge blankets in the clarifiers, which are used to treated the sewage water, according to the announcement.
“Extraordinary influent flowrates resulting from inflow and infiltration into the collection system can push the hydraulic capacity of plant structures, upsetting our regular operating volume of sludge,” the Public Notice said.
The county blamed operational problems for the Jan. 9 spill.
Justin Kirouac, county administrator, sent an email to the The Oconee Enterprise and the Athens Banner-Herald and me about the spill at 8:32 p.m. last night.
The report references heavy rain as an explanation for the problem.
“In anticipation of further winter rains and to lessen the chance of future events, we are taking steps to further reduce solids inventory, improve settling, and maximize our discharge to remove stored wastewater from the plant structures,” the Notice said.
“Also, we continue our infiltration and inflow monitoring of the collection system begun in 2015 to remove ground water and storm water inflow from the system,” the announcement read.
The discharged wastewater that exceeded Total Suspended Solids limits did receive “biological treatment, partial settling, U.V. disinfection, and final aeration before entering the stream,” the county said.
Water quality sampling is being performed in Calls Creek upstream and downstream from the spill, the county said.
The Calls Creek plant is permitted for only .667 million gallons per day of discharge.
A new plant next to the existing plant, expected to be operating in August, will have a capacity of 1.5 million gallons per day of discharge.