PROJECT EXPERIENCE
MASSACHUESTTS WATER RESOURCE AUTHORITY
DEER ISLAND WASTEWATER RESIDUALS TREATMENT
FACILITIES
Boston, Massachusetts
The Massachusetts Water Resources Authority (MWRA)
engaged Black & Veatch to provide design engineering services
for the residuals treatment facilities at the 480 mgd Deer Island
Wastewater Treatment Plant. The residuals management design
project was a major component in the Boston Harbor Cleanup
Project. The $230 million on-island sludge facilities designed
by Black & Veatch included:
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Eight 90-foot diameter (3 MG) egg-shaped digesters
Two 90-foot diameter (3 MG) digested sludge and gas
storage tanks
Project Elements
Centrifuge thickening
Digestion
Odor Control
Sludge storage
Key Team Members
John McNitt,
Project Manager
Gary Shimp,
Project Manager
Mario Francucci,
Project Engineer
Services
Predesign, conceptual
design, detailed design
Pursuit number or
Updated mm/dd/yy
Period of Services
06/1989 to 07/1996
Cost
Project Budget - $225 Million
Final Cost - $213.7 million
Owner’s Schedule - Eg. 36
months
Actual Completion - Eg. 34
months
Client Reference
Anandan Navanandan
(NAVA), Program
Management Unit
Massachusetts Water
Resources Authority
Charlestown Navy Yard
100 First Avenue
Boston, MA 02129
617- 242-6000
BLACK & VEATCH
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Gravity thickener facilities
Operations center
Odor control facilities
Digester gas handling and utilization facilities, and conveyance facilities for sludge
dewatering, drying and pelletizing

Six covered gravity thickeners to handle an average of 180 dry tons/day of scum and
primary sludge. Before thickening, primary scum is screened to remove floatable
materials. The screenings are stabilized by the addition of lime prior to transport to an
off-island landfill. The thickened primary sludge is mixed with waste activated sludge
(WAS) and pumped to the 3 MG egg-shaped digesters.
The digested sludge and digester gas is stored in a common tank using a flexible
membrane cover. A compressor facility provides boosted digester gas pressure for use
in the central power plant. A single building houses residuals operations and air
emissions control facilities, which consist of six two-stage chemical scrubbers followed
by five activated carbon absorbers with thermal regeneration capability. Special features
of the anaerobic digester facilities include:

Dual use of two 90-foot diameter sludge storage tanks for gas storage with gas
membrane (Dystor) covers

Use of particulate scrubbers for digester gas to reduce particulates and moisture in
digester gas prior to transfer to gas utilizations with centrifugal blowers

Use of high-efficiency waste gas burners to reduce emissions when flaring digester
gas
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Egg-shaped digesters constructed of steel
Modular design of the digester complex
This project won the Grand Honor Award from the Associated General Contractors of
Massachusetts, Inc. as part of its Build Massachusetts Awards Program VIII.
Pursuit Name • 1