Southerly Wastewater Treatment Plant (S71) New Effluent Pump Station & Effluent Conduit

Overview

Ribway served as the prime consultant for the City of Columbus, Ohio, on a $49.5 million project involving the construction of an effluent pump station, flushing water pump station, and effluent conduit at the Southerly Wastewater Treatment Plant (S71). These upgrades were designed to enhance the plant’s capacity, efficiency, and resilience under varying flow and river conditions.

Project Scope

This project included the following key components:

• Effluent Pump Station:
  • Firm capacity of 330 MGD.
  • Six (6) 66 MGD submersible pumps.
  • A 3,500-square-foot wet well.
• Flushing Water Pump Station:
  • Capacity of 15 MGD.
  • Four (4) 4 MGD vertical turbine pumps with automatic backflush strainers.
  • Surge relief valves for operational safety.
• Effluent Conduit and Discharge Structure:
  • A 600 MGD conduit measuring 16 feet wide by 8 feet deep and 2,000 feet long.
  • Final effluent gravity channel, metering station, and discharge structure to dissipate energy and reduce flow velocities before entry into the Scioto River.
  • Capability to utilize effluent pumps during high river levels for treated sewage discharge.
• Supporting Infrastructure:
  • New buildings, including:
    • 3,000-square-foot Effluent Control Building.
    • 400-square-foot Metering Building.
    • 2,500-square-foot Electrical Building.
    • 1,000-square-foot Sampling Building.
  • Dechlorination Chamber with Sodium Bisulfite induction units to meet water quality standards.

Electrical Design Highlights

The electrical system was designed to power and automate the various pumping and treatment systems:

• Electrical Power Distribution:
  • Six (6) 350 HP effluent submersible pumps with VFD motor controllers.
  • Four (4) 250 HP vertical flushing water pumps with VFD motor controllers.
  • Two (2) 15 HP disinfection induction units and two (2) 5 HP sample pumps.
  • PLC control system for automated operation.
  • Interior and exterior area lighting for all buildings.
• Power Supply Infrastructure:
  • Power sourced from the plant’s 14.4 KV switching station.
  • A new dual-ended 3,750 KVA substation with primary switches and oil-filled transformers.
  • 5,000 AMP Switch Gear housed in the Electrical Building, alongside VFD controllers and main PLCs.

Project Achievements

• Design Completion: October 2007
• Construction Completion: October 2009

In addition to engineering design, Ribway provided construction management, inspection, commissioning, and PLC programming services to ensure project execution and functionality.

Results and Impact

The new effluent pump station and associated infrastructure improved the Southerly Wastewater Treatment Plant’s capacity to handle peak flows and maintain compliance with environmental standards. The system’s automation and robust design provide reliable performance during both normal and high river level conditions, safeguarding public health and the environment.