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Anaerobic Digestion: Massachusetts’ New Clean Energy Resource

May 21, 2014

On January 31, 2013, the Commonwealth of Massachusetts Executive Office of Energy and Environmental Affairs (EEA) announced that the Patrick Administration had finalized a new ban on commercial food waste disposal. The ban requires generators of over one ton of food waste per week, such as supermarkets and restaurants, to divert their food scraps from landfills.

A number of incentives, such as grants from the Department of Energy Resources (DOER) and low-interest loans through a Massachusetts Department of Environmental Protection (DEP) fund, are already in place for the construction of anaerobic digestion facilities. Anaerobic digestion (AD) is a process by which organic waste is sealed in a container without oxygen, and broken down by microbes into a number of byproducts, including fibrous solids, nutrient-rich liquid, and biogas such as methane and carbon dioxide. The biogas can then be used to generate electrical power. This process turns organic waste, which makes up as much as 25% of the waste stream to landfills and incinerators, into usable, clean energy.

A number of wastewater treatment facilities in Massachusetts, including the Massachusetts Water Resources Authority (MWRA), are already using anaerobic digestion to treat sewage. Starting in June 2014, the MWRA, which provides sewer service to 43 Massachusetts municipalities, will begin a pilot program to measure changes in biogas yields from introducing food waste into an AD chamber at the Deer Island Sewage Treatment Plant.  DEP has indicated that 70% of the Deer Island plant’s energy needs may be derived from food waste. A Freetown Stop & Shop is also incorporating an AD facility, which DEP indicates is anticipated to power approximately 50% of the store’s energy needs.  DEP has also indicated during past presentations that the Commonwealth will issue requests for three additional AD sites to be built on state-owned land to serve as models. However, the EEA anticipates that even more AD facilities, constructed on private land, will be necessary to accommodate the demand generated by the food waste ban.

Construction of AD facilities presents unique permitting challenges.  For example, development of an AD facility at Jordan Dairy Farm in Rutland, which began operation in 2011, took five years to bring the project from inception through completion. Since that time, the DEP has amended its regulations for solid waste management to include a general permit for anaerobic digesting facilities that receive a monthly average of 100 tons of waste per day or less. Facilities will apply for coverage under this general permit by adhering to the standards established by the DEP, streamlining the permitting process. But even the general permitting process does not anticipate all potential considerations, such as the siting of AD facilities and compliance with existing zoning. As Massachusetts strives to meet its goal of 30% waste stream reduction by 2020, both owners and regulators must be prepared to adjust to new challenges facing this rapidly growing technology.

In June, Beals and Thomas will be attending the Massachusetts Commercial Food Waste Vendor Fair: “Everything you need to divert food waste from your waste stream,” sponsored by DEP, U.S. EPA Region 1, and RecyclingWorks in Foxborough, Massachusetts. The fair will be the marquee event for businesses and institutions looking to comply with the ban and divert food waste.

Eric Las is a Principal at Beals and Thomas, Inc. in Southborough, MA.