Cobb County Water System spilled 3.9 million gallons of treated wastewater that did not meet quality standards into Lake Allatoona this week.

The spill was discovered Thursday after routine water sampling found the wastewater had not been fully treated to the Georgia Environmental Protection Division standards. The water was disinfected and will not impact the drinking water supply, according to county officials.

Just before Memorial Day weekend in May, 12 million gallons of treated wastewater that also did not meet standards spilled into the lake.

The Northwest Water Reclamation Facility processes and releases 12 million gallons of water per day into Lake Allatoona, according to county officials.

Water system employees will continue water testing upstream and downstream and are “investigating the cause and working to ensure that the plant is operating normally,” according to a news release.

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