- Hampton Roads Sanitation District
- Norfolk, Virginia
- Our Role
- Design, Construction Services, Public Involvement
- 10.8 mgd
- Construction Cost:
- $7.1 million
- New Construction
- 2 years, 6 months
- Innovative pump design improves the ability to manage wet weather flows
- Increased capacity reduces the risk of overflow into nearby waterways
- Preventing the collapse of a failing wet well immediately improved public safety
- Sensitive design and construction approaches highlight best practices for building in a neighborhood.
The Norchester Pump Station was built in the 1940s as a wet well/dry well facility. As the area’s population grew during the last 70-plus years, so too did the wastewater flows processed by the pump station. In addition, extreme microbial corrosion of the station’s concrete and piping had taken its toll, rendering the facility in danger of wet well collapse. The facility’s increased customer demand, combined with significant microbial corrosion, signaled to HRSD that a new pump station was necessary.
HRSD and Gannett Fleming embarked on a journey to optimize the design of a new pump station for both average day and projected wet weather peak conditions.
The Gannett Fleming design team replaced the existing system with a self-cleaning, trench-type wet well, in accordance with the standards set by the Hydraulic Institute (HI), the global authority on pumps and pumping systems. This type of facility creates optimum hydraulic conditions for the pumps, reducing maintenance and extending their life. A permanent bypass pump located outside the station helps to manage a peak flow of 10.8 mgd and offers the ability to respond automatically to high wet well levels. It also saves power and fuel.
Because the Norchester Pump Station is nestled in the heart of a residential neighborhood, the construction team was careful to minimize disruption. Vibration monitoring technology and temporary stoppages of vibratory sheet pilings reduced the impact on nearby properties, some as close as 7 feet from the project site. As well, a high-strength odor control system, including a biological trickling filter and secondary carbon scrubber, effectively addressed community concerns.
- Self-cleaning, trench-type wet well is the first-of-its-kind in the HRSD collection system
- Permanent bypass pump outside the station offers automated ability to respond to high wet well levels, and saves power and fuel
- Biological trickling filter and secondary carbon scrubber provide advanced odor control
- Architectural details and landscaping create curb appeal and complement the surrounding residences.