Columbus, OH – Southerly CEPT S88/S89 Clarification & Disinfection

The City of Columbus Southerly CEPT S88/S89 Clarification and Disinfection Projects increased wet-weather treatment capacity at the Southerly Wastewater Treatment Plant to support regulatory compliance and improve performance during peak flow events. To meet the required capacity of approximately 130 MGD, the City implemented Chemically Enhanced Primary Treatment (CEPT) with high-rate disinfection. Shook Construction was awarded two of the three major CEPT construction contracts: Clarification and Disinfection.

Shook’s work included:

• New CEPT influent, flow control, metering, and splitter structures
• Two 180-foot-diameter CEPT clarifiers 
• Large-diameter influent and effluent conduits
• CEPT chemical building
• Ferric chloride and polymer storage/feed systems
• Sludge pumps and flushing water systems
• New disinfection and dechlorination infrastructure
• 96-inch CEPT effluent conduit
• Flow metering improvements
• Equipment and piping upgrades at the CEPT Disinfection Chamber
• Modifications to the existing Chlorine Control Building for sodium hypochlorite service
• New Dechlorination Control Building for the sodium bisulfite system

Both projects included associated mechanical, plumbing, electrical, instrumentation, controls, and integration work. Through careful coordination and execution, Shook helped deliver critical wet-weather treatment improvements that strengthen Columbus’ wastewater infrastructure, support regulatory compliance, and enhance long-term plant reliability.