AWWA ACE54394

Clayton County Water Authority (CCWA) owns and operates three surface water production plants (WPP) that supply drinking water to Clayton County, Georgia. CH2M HILL and CCWA are currently developing a strategy to combine optimized coagulation and pretreatment conditions and the use of ultraviolet (UV) advanced disinfection to comply with Disinfection Byproducts Rules, Interim Enhanced Surface Water Treatment Rule (IESWTR) and anticipated Long Term 2 ESWTR requirements. The Plants' capacities are 12 mgd at J.W. Smith, 20 mgd at W.J.Hooper, and 10 mgd at the Freeman Rd. Raw water quality is typical for reservoirs in the Southeast except for the Hooper Plant which is subject to wide variations in raw water turbidities. The primary objective of this project is the use of UV advanced disinfection and optimized pretreatment conditions to meet the current and future water quality regulations. Modifications to the pretreatment facilities and the addition of UV disinfection will be based on the following approach: conducting enhanced coagulation jar test studies to determine optimum pH and coagulant type and doses needed to maximize total organic carbon (TOC) reduction; screening pretreatment conditions (mixing and loading rates) to maximize pretreatment performance; evaluating the use of powdered activated carbon (PAC) for TOC removal; developing schematic design and regulatory coordination for UV disinfection; and, completing detailed design, construction and validation of UV facilities based on the selected equipment. Includes tables.