# Virginia's eProcurement Marketplace #IFB 127897

UOSA GAC Treatment Optimization Project for PFAS Mitigation and Carbon Contactor Retrofits

**Posted:** September 15, 2026
**Respond By:** October 06, 2026
**Identifier:** IFB 127897
**NAICS:** 237110, 562910

The Upper Occoquan Service Authority (UOSA) is seeking bids for a GAC Treatment Optimization project focused on PFAS mitigation at its Centreville, Virginia facility.
- Government Buyer:
  - Upper Occoquan Service Authority (UOSA), Centreville, VA
- Project Scope:
  - Phase 1: Retrofit one L/2 Building carbon contactor (two cells) for PFAS pilot study
    - Includes restoring upflow and downflow capability via underdrain nozzle modifications
    - Proof-of-concept evaluation for carbon transfer improvements
  - Phase 2 (if authorized): Retrofit remaining seven carbon contactors (fourteen cells) based on Phase 1 results
- Products/Services Requested:
  - Construction and modification of water treatment systems
  - Pilot study implementation for PFAS removal
  - Evaluation and improvement of carbon transfer processes
- Unique Requirements:
  - Phased retrofit approach with expansion contingent on pilot study outcomes
  - Emphasis on PFAS mitigation and water treatment optimization
- OEMs and Vendors:
  - No specific OEMs or vendors are named in the solicitation
- Technical Focus:
  - Upgrades to carbon contactors and underdrain nozzle systems
  - Water treatment system enhancements for PFAS removal

### Description

This solicitation is an Invitation for Bids (IFB) issued by the Upper Occoquan Service Authority for the GAC Treatment Optimization project. The project involves retrofitting one L/2 Building carbon contactor, consisting of two cells, to serve as the PFAS pilot study system, restoring upflow and downflow operating capability, and implementing a proof-of-concept evaluation for carbon transfer improvements. If authorized, Phase 2 will include retrofitting the remaining seven carbon contactors with selected improvements based on Phase 1 results. The work location is 14631 Compton Rd., Centreville, VA.

[View original listing](https://mvendor.cgieva.com/Vendor/public/IVDetailsPrint.jsp?rfp_id_lot=127897&rfp_id_round=1)