Cumming Advanced Water Reclamation Facility

City of Cumming’s 8.0 MGD Advanced Water Reclamation Facility (AWRF) included a 6.0 MGD upgrade from the original 2.0 MGD facility. (Filtration added in 2000 expanded the facility to 3.0 MGD, but was removed in this expansion.) The final construction cost was just under $30 million (or $5 per gallon) and was completed by Skanska in the summer of 2008.

The only original components to remain included one oxidation ditch and two clarifiers (shown on the right side of the photo). This facility was designed and managed in-house by CEC personnel, with the exception of an electrical and HVAC design subcontract.

The upgrade included abandoning the existing influent pump station and the existing headworks and providing a new, similar influent pump station and screening and grit and grease removal facility. The biological treatment process included an expansion and upgrade of the existing oxidation ditch aeration process followed by peripheral feed clarifiers. Additional tertiary treatment was added in the form of a flocculation and inclined plate settling system for phosphorus removal and effluent sand filtration. The previous disinfection process, using gas chlorination and sulfur dioxide dechlorination, was replaced by ultraviolet light disinfection.

Also, the Envirex Cannibal process was included to handle the biological solids. Inerts and digested sludge is dewatered by the existing centrifuge. Phosphorus is removed chemically in a two-step P-scalping process. Chemical sludge is dewatered with a second (new) centrifuge.

Civil Engineering Consultants presented a paper at the 2008 Fall Conference of the Georgia Association of Water Professionals, which provided an overview of the newly completed facility. A copy of CEC’s presentation can be found here (PDF 3.6MB)