Nansemond SWIFT Facility and Nansemond Recharge Wells

Garney, in partnership with Tetra Tech and Carollo Engineers, is leading the design and construction of the greenfield Nansemond SWIFT Facility and Nansemond Recharge Wells in Suffolk, Virginia. The facility is designed to ultimately recharge up to 34 MGD of SWIFT Water® into the Potomac Aquifer. Built-in design flexibility allows HRSD to adjust or enhance treatment processes as the program grows. This work is part of the Hampton Roads Sanitation District’s Sustainable Water Initiative for Tomorrow (SWIFT), a program focused on restoring and protecting Eastern Virginia’s primary groundwater source.

The facility will receive treated effluent from the Nansemond Treatment Plant, further purify it to match natural groundwater chemistry, and deliver it through up to 19 MAR wells. This effort will help restore declining groundwater levels, reduce nutrient loading to the Chesapeake Bay, and may lessen risks associated with saltwater intrusion and land subsidence. Once complete, the program will strengthen regional water sustainability and advance HRSD’s mission to protect public health and the environment for future generations.

Solutions

Advanced Treatment and Water Quality: The project includes construction of a greenfield tertiary and advanced water treatment (AWT) facility featuring rapid mix, flocculation, sedimentation, ozonation, biofiltration, granular activated carbon (GAC) adsorption, ion exchange, ultraviolet disinfection, chlorination, and pH adjustment. These systems work together to produce SWIFT Water that matches natural groundwater chemistry and meets program standards for recharge.

Recharge and Conveyance: A new pumping and conveyance system delivers treated SWIFT Water to up to 19 MAR wells for injection into the Potomac Aquifer. The wells will reach depths of roughly 1,500 feet, intersecting with the aquifer beginning around 500 feet below ground. This system supports sustainable groundwater supply and regional environmental needs including Chesapeake Bay restoration, sea level rise resiliency, and saltwater intrusion mitigation.

Design Innovation and Collaboration: Garney worked with AM-Team, a Belgium-based firm specializing in CFD and kinetic modeling, to evaluate ozone contactor performance. Their modeling showed improved reaction kinetics and lower bromate formation when using a co-current injection approach. This led to a flexible contactor design that allows the system to operate in either co-current or counter-current mode with minimal added cost. The result is a more adaptable and efficient facility.

Project Status

Construction is underway, with substantial completion expected in 2029. Site clearing is complete; erosion and sediment controls are in place, and foundation work for the SWIFT Influent Pump Station and Recharge Well Backflush Equalization Tank has begun. Supply and backflush piping is complete at Recharge Wells 8 and 10 and progressing at Wells 7 and 9. Stormwater improvements remain ongoing at Pond 1 and Pond 2.