Atlantic Treatment Plant Thermal Hydrolysis Process and FOG Receiving Station
Virginia Beach, Va.
BEST PROJECT
Sent by: Crowder Construction Co.
Owner: Hampton Roads Sanitation District
Lead Designer: HDR
Construction Manager at Risk: Crowder Construction Co.
THP Process Manager: Brown and Caldwell
The Hampton Roads Sanitation District’s Atlantic Treatment Plant, which has an allowable design capacity of 54 million gallons per day, operates as a high-rate activated sludge plant that is capable of meeting demand biological oxygen and the total removal of suspended solids. With this project, the team aimed to produce a Class A biosolids product and provide future increases in solids handling capacity. All this had to be achieved without increasing the capacity of the digester. It was also necessary to integrate a new fat, oil and fat receiving station in the treatment process of the thermal hydrolysis process.
As a construction manager at risk, Crowder was integrated into the pre-construction phase as well as construction management. The project underwent significant value engineering, with innovative ideas for using existing real estate that proved key to cost savings and reducing the overall footprint of the project. This effort included repurposing the plant’s abandoned dissolved air flotation thickening room into a multi-purpose space that would house non-potable water filtration, solids screening and transport, solids bypass piping and a new electrical room. In addition, the existing double hot water boiler room was converted to house a new steam boiler, deaeration system, steam distribution and heated non-potable water system.
Photo courtesy of Crowder Construction Co.
A new predewatering building was also added, which mitigated constructability issues by placing centrifuges inside the existing gravity belt thickener room. The placement of the building posed a significant challenge on a compact site with limitations created by previously overburdened floors. The team brainstormed with the client on how to fit the large installation into a compact space to eliminate stacks and reduce costs.
Additionally, Crowder reviewed the owner’s planned approach to digester cleaning, offering an alternate and improved sequence. As a result, the overall project schedule was reduced by nearly six months, allowing earlier access to more critical digester facilities and reducing the number of times a particular digester in the sequence had to be temporarily removed from service The six-year project was completed on budget in December 2023.
