Tetra Tech partnered with Hampton Roads Sanitation District (HRSD) to expand the Nansemond Treatment Plant’s capacity, implementing innovative nutrient removal technologies to support HRSD’s SWIFT initiative and protect Virginia’s water resources.
HRSD is implementing an innovative approach to address Chesapeake Bay restoration, relative sea level rise, saltwater intrusion, and aquifer depletion in eastern Virginia. Through the Sustainable Water Initiative for Tomorrow (SWIFT), HRSD is recharging the Potomac aquifer with highly treated SWIFT Water® that meets drinking water quality standards and matches the aquifer’s geochemistry. Central to this effort is the Nansemond Treatment Plant Advanced Nutrient Reduction Improvements (ANRI) Phase II project, a $308 million design-build initiative.
Benefits
- Expanded capacity from 30 to 50 MGD to support consolidation of wastewater treatment
- $308M design-build upgrades for advanced nutrient reduction
- PdNA technology enhances nitrogen removal efficiency and increased capacity in existing infrastructure
- Upgraded electrical and instrumentation systems for operational resilience
As the lead engineer, Tetra Tech is expanding the plant’s permitted capacity from 30 to 50 million gallons per day (MGD), while enhancing nutrient removal and operational efficiency. Our team is integrating partial denitrification-anammox (PdNA), an advanced nitrogen removal technology that reduces methanol use, lowers energy demand, and minimizes the facility’s carbon footprint. We are designing additional upgrades and process improvements, including AvN® control, primary solids fermentation, electrical and instrumentation enhancements, and odor control. Services provided include process design, electrical, mechanical, structural, architectural, instrumentation, civil, and permitting, as well as assistance with grant fund applications, permitting, construction, testing, start-up, and training services.
Tetra Tech experts leverage our Leading with Science® approach to deliver forward-thinking solutions to help HRSD improve water quality, protect the Chesapeake Bay, and secure a resilient groundwater supply for future generations.