Massachusetts Water Resources Authority’s Path to Full Resource Recovery

On behalf of the Massachusetts Water Resources Authority (MWRA), CDM Smith Inc. (CDM Smith) recently completed an evaluation of all currently available options for treating and managing the wastewater solids from their Deer Island Treatment Plant (DITP) and determined which would be useful in enhancing existing operations. One impetus for the study is the emergence of new or innovative technologies that may lead to more efficient operation that were not available when the plant was put in operation in 1995. MWRA also desired to explore developments in the industry and residuals management practices of their peer utilities prior to making any major equipment replacement decisions.In addition to assessment of technologies, the MWRA also needed an evaluation of emerging trends in operating practices, in areas such as co-digestion of alternative feed stocks. This latter concept was very timely since the Massachusetts Department of Environmental Protection intends to ban the landfilling or incineration of some source-separate organics such as food wastes from supermarkets and food-producing industries.The overarching goal of the study was to optimize MWRA’s existing residuals processing operations and identify capital projects that would extend the useful life of these facilities by 20 years. The study recommended improvements which will assist MWRA on a path to full resource recovery. Specific initiatives include co-digestion, modification and expansion of the existing combined heat and power plant, struvite mitigation via nutrient harvesting and other improvements designed to optimize existing thickening, anaerobic digestion, dewatering and thermal drying facilities.