Regional Wastewater Treatment Facility Biological Nutrient Removal (BNR) Upgrade

Client: Clearfield Municipal Authority, Clearfield County, PA

Project Cost: $37,000,000

Year: 2017

Gwin, Dobson & Foreman designed one of the state’s largest and most technologically advanced BNR wastewater projects for the Clearfield Water Authority. This $35 million project employs a unique step-feed process for treatment of wet-weather flows while preserving BNR bio-mass. The Clearfield wastewater treatment plant was upgraded and expanded under the following criteria:

Capacity & Process Parameters

  • Capacity: 4.5 MGD (ADF); 16.0 MGD (Maximum Month); 25 MGD (Peak)
  • Permitted Nutrient Discharge Concentrations- 6.0 mg/l (TN) and 0.80 mg/l (TP)

Treatment Goals

  • Permitted Annual Mass Loading Limits: 82,191 Ibs. (TN)/10,959 Ibs. (TP)
  • Capacity Expansion for Previously Bypassed Wet-Weather Flows (6 MGD to 25 MGD)

Unit Operations and Process Systems

  • Headworks Building with Fine Screens and Vortex Grit Separators
  • Suspended Growth Nutrient Removal Technology configured for Hybrid Stage 5-Bardenpho, Virginia Initiative Plant (VIP) and Ludzack- Ettinger Processes
  • Oxic Zone Aeration System (Turbo Blowers)/Anoxic- Anaerobic Zones Mixing System (submersible pumps)
  • Fine Bubble Membrane Diffuser System and Submersible Mixers
  • Reactor Feed Distribution Box with Gravity Step Feed System for Wet Weather Flows
  • Final Clarification using Spiral-Blade Collection Mechanism and Stamford Baffles
  • Return Pumping for Return Activated Sludge, Mixed Liquor Suspended Solids and Nitrate Flow
  • Ultraviolet Disinfection and Cascade Aeration Channel
  • Solids Handling- Conversion of Anaerobic Sludge Digesters to Aerobic Digestion with Sludge Storage, Belt Thickener, Centrifuge Dewatering, Biosolids using Agricultural Land Application