Effluent Disc Filter Project

Meeting TMDL Discharge Limitations & Protecting the Environment:

HOVMSD has determined that additional treatment will be necessary to achieve compliance with its phosphorus and suspended solids Total Maximum Daily Load (TMDL) allocations. The District conducted a pilot study that validated its effluent would meet all requirements using chemically enhanced flocculation and disc filter effluent filtration technology. The effluent disc filters are being installed in an existing building and can provide filtration capacity to match the existing Biostyr maximum capacity of 26 MGD.

The District has an NPDES discharge permit that sets limits on the amount of both suspended solids and phosphorus that can be discharged to the Fox River. It is determined that tertiary treatment of the effluent is needed in order to meet the required limits.

  • Water Quality Based Effluent Limits for TSS and Phosphorus

Workflow and Schedule

  • Project out to Bid – February 16, 2022
  • Bid Opening – March 24, 2022
  • Substantial Completion – July 16, 2024
  • Final Completion – October 29, 2024
  • Low-P Limit Effective – December 31, 2025


  • Clean Water Fund Loan = $19M▪ Includes: Facility Plan, Design, Project/Construction, Required Contingency, Engineering/CRS, and Closing Costs
  • Project Enhancements
    • Chlorination/Hydraulic Improvements
    • Locker Room/Lactation Room
    • New Roof
    • NFPA 820