BEAM Engineering has been hired through the MassCEC Organics-to-Energy Program and the Town of Greenfield to conduct a feasibility study on the implementation of an Anaerobic Digester in the town of Greenfield.  
 
The overall aim of the study is to find a long-term, economically viable, “green” solution to the disposal of the town's Waste Water Treatment Sludge, as well as other locally generated organic wastes.  More specifically BEAM will assess the feasibility of establishing an Anaerobic Digester and Combined Heat and Power facility to be located at the Greenfield Transfer Station with the purpose of renewable energy generation, the creation of organics recycling and agricultural capacity, with the ultimate goal of reducing costs.
 
The proposed site of the anaerobic digester is the Greenfield Transfer Station, located 86 Cumberland Road in Greenfield, Massachusetts.  The Solid Waste and Recycling Division of the Department of Public Works operates the Transfer Station, as well as performing curbside collection of rubbish and recyclables which is transported daily to their disposal/processing centers in Springfield.  The material of interest for anaerobic digestion is pre-consumer organic waste (local generators such as supermarkets and restaurants), industrial food processing waste, green waste (grass clippings), and post-consumer organic waste.

 
The central organic feedstock for the proposed digester is the sludge from the Greenfield Wastewater Treatment Plant (WWTP) located at 384 Deerfield Street, Greenfield, MA, only 1.3 miles from the Transfer Station.  The WWTP is a publicly-owned treatment works (POTW) operated by the Sewer/Drainage/Wastewater Division of the Greenfield Department of Public Works and was selected for the EPA’s 2011 Regional Wastewater Treatment Plant Excellence Award.  Currently the sludge is being hauled off-site to the Montague WWTP to be thickened, after which it is landfilled in Vermont or sent to Upper Blackstone Water Pollution Abatement District, costing the town approximately $200,000 annually.   While the Greenfield WWTP is not an ideal location for the anaerobic digester because of flooding issues (the facility sustained approximately $600,000 in damages from Hurricane Irene), the Greenfield Transfer Station provides an excellent location because of the space available and abutting land use.  The Greenfield WWTP will provide nearly 2 million gallons of sludge to the digester per year. 
 
BEAM Engineering intends to explore how these different feedstocks and operating conditions—such as loading rates, temperature, nutrient composition, alkalinity, pH, or toxicity—could potentially upset or optimize the anaerobic digestion process to produce methane in a CHP system.
 
The waste heat generated at the CHP plant will be used to meet digester heating requirements, as well as sludge processing, operational heating needs, and on-site building heat.