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
Charlestown Bus Facility Shoreline Stabilization and Yard Improvements
The existing steel sheet pile seawall, which protects the facility from flooding and river erosion, was severely deteriorated. SGH investigated the failing seawall, including the pavement and soil loss behind it, and designed new shoreline stabilization and drainage systems.
Northeast
99 Summer Street Parking Garage
The parking garage, constructed with concrete slabs on metal deck supported by steel beams and columns, includes two below-grade levels under a twenty-story office building. SGH performed a condition assessment and designed repairs to extend the useful life of the parking structure.