Shenandoah Wastewater Treatment Facility Improvements

Krebs was engaged by Coweta County Water and Sewerage Authority (CCWSA) to design the upgrades and expansions of their Shenandoah Wastewater Treatment Facility (WWTF). The project increases treatment capacity from 2 MGD (average) to 6 MGD (average) and 12 MGD (peak). The improvements consist of new headworks with screening and grit removal systems, influent pumping, retrofitted existing aeration basin and new aeration basin with BNR treatment, blower building, final clarifiers, U.V. disinfection, tertiary filters, RAS/WAS pump station, solids dewatering and Class A biosolids drying facility, standby power generation, new power distribution, SCADA and instrumentation, and control improvements. The project construction is scheduled to begin in the summer of 2023.

The detailed design included careful consideration of project construction sequencing measures necessary to provide the existing wastewater treatment capacity of 2 MGD throughout project construction activities while retrofitting the existing WWTF. The existing project site of the Shenandoah WWTF is limited by property boundary constraints and therefore requires that the proposed project site plan reuse the existing structures onsite to minimize the expansion of the site’s footprint. These project boundary limitations required creative site planning while reusing and retrofitting the existing structures allowed for a reduced project footprint, resulting in construction cost savings.

During the design process, four major process equipment items were preselected for the improvements project, including U.V. disinfection equipment, biological nutrient removal system, solids dewatering equipment, and biosolids drying equipment. This preselection process included evaluating competitive equipment proposals to determine the most efficient alternative for each process.