Winthrop, MA
MWRA Deer Island Wastewater Treatment Plant, Egg-Shaped Digesters
Scope/Solutions
The Deer Island Wastewater Treatment Plant, which is owned and operated by Massachusetts Water Resources Authority, removes pollutants from wastewater that originates in homes and businesses in the greater Boston area. Buchart-Horn, the Electric Boat Division (EBDiv) of General Dynamics, and Perini retained SGH to develop the seismic design for egg-shaped digester tanks and their supporting concrete structures.
SGH helped develop the seismic design for the eight 3-MG egg-shaped digesters and two 3-MG gas storage tanks. Highlights of our analyses include the following:
- Evaluated the structures of the digesters and storage tanks
- Designed the reinforced concrete ring walls that support the digesters and gas storage steel tanks, which included an innovative concept for the anchorage of the steel tank base plate to the ring wall used to transmit the large overturning moment.
- Performed finite element analyses that included fluid-structure interaction for horizontal and vertical ground motion
- Determined stresses in the tank wall from the impulsive components
- Computed the convective components of liquid accelerating within the steel shell
Project Summary
Solutions
New Construction
Services
Structures | Advanced Analysis
Markets
Infrastructure & Transportation
Client(s)
Buchart-Horn | General Dynamics
Specialized Capabilities
Seismic Engineering | Computational Mechanics
Key team members

Additional Projects
Northeast
MBTA Iron Horse Park Operations Control Center
In addition to serving as the prime consultant, SGH provided structural engineering, civil engineering, and building enclosure consulting services for the project.
Northeast
Riverside Park Pedestrian Bridge No. P34
The bridge carries a pathway over the Charles River in Riverside Park, which is operated and maintained by the Department of Conservation and Recreation (DCR). SGH assessed the condition of the circa 1915 pony-truss bridge and was the engineer of record for the rehabilitation.