Rainfall from Hurricane Sally causes treatment plant backup, 2 million gallon sewer spills

Heavy rainfall from Hurricane Sally on Sept. 17 caused a total of 2.87 million gallons of sewer to spill in DeKalb County at 19 locations, county officials said.

The remnants of Hurricane Sally resulted in severe rainfall throughout DeKalb County with 24-hour rainfall totals of between four and six inches recorded throughout much of the county. The intense storm event caused flooding and severe stormwater runoff and ranks among the largest events of the past 10 years.

The spills, including a 2.1-million-gallon spill on Meadow Creek Path, was caused by stormwater intrusion into the wastewater system, county officials said.

A preliminary engineering analysis indicates that the Meadow Creek Path sewer spill was caused when the plant reached its treatment and storage capacity, which has been temporarily reduced by the ongoing construction of a new $300 million plant.

The new treatment plant will have an increased capacity of 18 million gallons per day, from the current 36 million gallons per day to 54 million gallons per day. The project is 72 percent complete with an anticipated completion date of 2022.

In 2010, a decision was made to demolish a component of the current plant to make room for the new plant’s footprint.  While the current plant functions effectively during normal operations, the elimination of a redundant clarifier reduces the plant’s ability to manage