Project No. 25502

Project Start Date: Fall 2023

Estimated Completion Date: TBD

Project Manager: Brian Stone 703-737-7120

Project Description:  During the last two decades the solids treatment process has remained relatively unchanged. However, water usage has been declining due to conservation and low-flow fixtures which causes an increase in solids concentrations of sanitary sewer flow. The Town's solids processing facilities have been impacted and a biosolids capacity analysis is underway to evaluate current system treatment capacities.

The study will recommend near- and long-term process expansions and technology upgrades. This multi-year project includes engineering design and construction for replacement or upgrade of existing infrastructure (four anaerobic digester domes - two constructed in 1970, one in 1987, and one in 1994), solids capacities expansions, odor control, electrical substation B upgrades and other treatment technology enhancements identified to ensure regulatory requirements are met. The Water Pollution Control Facility Odor Control & Biofilter Media Replacement (25504) and the remaining phases of the Water Pollution Control Facility Storage Tanks - Re-coating & Rehabilitation (18002) were consolidated into this project.

Project Updates:  On August 8, 2023, Town Council approved the issuance of a task order for Hazen to prepare a preliminary engineering report (PER) for solids processing and nutrient removal improvements at the WPCF.  As of July 2024, Town Council approved a design task order to Hazen based on the PER as it related to the solids processing improvements. The design phase will be approximately a year with construction documents for bid posting estimated for summer 2026.