Arlington County is taking a bold step towards environmental sustainability with the launch of its Re-Gen project – a comprehensive upgrade to the Water Pollution Control Plant (WPCP) focused on turning wastewater into renewable energy and nutrient-rich soil amendments. This progressive design-build project will revolutionize solids handling facilities using state-of-the-art technology, all while supporting a cleaner, greener community.
In partnership with PC Construction as the design-builder, Stantec as the engineer, and HDR as the program manager, the County will incorporate advanced systems – including thermal hydrolysis process (THP) – pre- and final-dewatering facilities, primary and secondary anaerobic digesters, odor control, biogas treatment, and steam generation. The THP will allow the WPCP to produce Class A biosolids suitable for use as fertilizer, while capturing and treating biogas for use as a renewable energy source.
These improvements align with Arlington County’s Solids Master Plan and are geared toward reducing greenhouse gas emissions and achieving negative net energy usage, supporting the County’s vision for Envision Gold verification.
The Early Work Package is now underway and sets the stage for this multi-year modernization effort, beginning with crucial site preparation activities such as grading, building demolitions, utility relocations, and foundation work for future treatment systems—all while maintaining uninterrupted operations at the facility. Major construction activities are scheduled to commence late 2026, with completion projected in 2031.
The heart of the Re-Gen program lies in its innovative solids-handling systems, which will include thermal hydrolysis and anaerobic digestion to produce renewable resources, modern dewatering and screening equipment, enhanced truck loading, and sophisticated odor control. These upgrades will enable Arlington County to transform biosolids generated during wastewater cleaning into reusable Class A biosolids and renewable natural gas, substantially lowering the Plant’s carbon footprint.
With the Water Pollution Control Plant currently treating 23 million gallons of wastewater each day from homes and businesses, the Re-Gen project represents a transformative investment in the region’s environmental health and resource recovery capabilities.