Virginia Initiative Plant Nutrient Reduction Improvements

Virginia Initiative Plant Nutrient Reduction Improvements

Virginia Initiative Plant Nutrient Reduction Improvements

With sanitary sewer overflow (SSO) consent decree negotiations in progress, Hampton Roads Sanitation District (HRSD) had to start planning for nutrient removal upgrades at its Virginia Initiative Plant with a capacity of 40 million gallons per day. We worked with HRSD to develop a plan that tackled multiple challenges head-on.

Nutrient removal targets required effluent quality of 5 mg/l total nitrogen and 1 mg/l total phosphorus. Concurrently, our team needed to address uncertain plant hydraulic capacity requirements from developing SSO reduction goals. Together we analyzed the trade-offs between each level of increased plant hydraulic capacity and developed a cost-effective approach. Other challenges included a tight site located over a closed municipal landfill and an aggressive completion schedule.

Our phased delivery approach over the project life cycle met the regulatory requirements and fast-tracked the construction schedule. Building information modeling (BIM) and interactive workshops facilitated informed decision making, and enabled development of an innovative design concept. The design includes a new preliminary treatment facility with an influent pump station that is capable of discharging a portion of the peak flow to a new equalization tank and a new Versatile Bioreactor (VBR).

With flexibility built into the design, these new facilities can operate in series or in parallel with the existing 3-stage nutrient removal processes, depending on the priority of nutrient removal or hydraulic constraints.

Virginia Initiative Plant Nutrient Reduction Improvements
Hampton Roads Sanitation District

Norfolk, VA
United States

40 mgd plant