Tighe & Bond managed the original conceptual planning, permitting, design, and construction of this facility, which has received sludge from the Deer Island and Nut Island wastewater treatment facilities in Greater Boston since 1991. The project was a major step forward in the clean-up of Boston Harbor. Since that time, our team has overseen several expansion projects, including a $44 million expansion to increase capacity from 140 dry tons per day to 280, and generate 95% solids, with the resultant heat-dried product used as a fertilizer. This multi-phase project required a full-scale pilot test to confirm process gas recirculation would reduce energy requirements and venturi scrubbers and packed towers would remove particulates.
With the pilot test complete, Tighe & Bond oversaw building demolition, and the installation of new storage silos, expansion of the dewatered sludge cake loading garage, installation of new railroad track, utility modifications, and pier reconstruction work. To power the facility Tighe & Bond also designed new, twin high-pressure gas mains stretching almost 2,700 linear feet under the Fore River. Inside the facility, our team oversaw the installation of 12 dewatering centrifuges and additional sludge drying trains to increase throughput and allow process gas recirculation. Improvements to the sludge drying system included product cooling, enhancement of product fertilizer value via chemical addition, improved particulate control, improved sludge mixing, and fugitive dust collection.
Tighe & Bond is currently managing on-going capital improvements at the facility, including painting of sludge storage tanks and dried pellet storage silos, gas train improvements, conveyor replacements and improvements, dust collector replacements, motor control center replacements, and mechanical and electrical work.