UMass in line for anaerobic digester plant
A facility that turns organic matter, including food waste and sludge from wastewater treatment plants, into both a source of renewable power and fertilizer could be built at the University of Massachusetts.
The state Department of Environmental Protection and the Patrick administration are pursuing construction of three anaerobic digester plants on state-owned land, with UMass property in Hadley, adjacent to both Amherst’s wastewater treatment plant and the cogeneration plant at UMass, one possible location.
Town Manager John Musante said Amherst is supporting conceptual plans that could lead to the development of this anaerobic digester.
“The environmental benefits are real, worthwhile and significant,” Musante said.
Edmund Coletta, spokesman for the state DEP, said anaerobic digestion is part of an effort to reduce the state’s waste stream by 2 million tons per year by 2020.
“A big part of this is making it so cities and towns and other generators of waste are able to pull food waste and other organics out of the waste system,” Coletta said.
The Patrick administration in November amended its solid waste and wastewater regulations so that food and other organic materials could more easily be turned into renewable energy production and composting.
Currently, organics make up about 25 percent of the waste stream, with about 100,000 tons composted annually. The state would like to increase this amount to 450,000 tons composted annually.
At the same time, the new rules provide incentives for anaerobic facilities to add organics to boost the generation of what is known as biogas. When the organics break down in a large tank, biogas can be drawn off and used for energy and electricity, with the remaining materials reused as fertilizer.
Kenneth Kimmell, commissioner of the DEP, said in a statement that organic materials take up valuable space in landfills and cause emission of greenhouse gases in incinerators.
“When we merely discard organics, we are wasting a great opportunity to capture the economic and environmental benefits from recycling and converting this material into clean renewable energy and valuable fertilizers,” Kimmell said.
While no sites have yet been selected or identified, recent meetings have suggested the UMass land in Hadley could be suitable.
Guilford Mooring, superintendent of the Department of Public Works in Amherst, said Amherst could benefit by disposing of its wastewater sludge there and composting it to create energy.
“Natural gas can be used to make energy on site or be shipped to the UMass plant,” Mooring said.
Mooring said this could also save money, as currently sludge is trucked from the site two to three times daily, at an annual cost of $400,000.
The anaerobic facility might also accept sludge from other nearby treatment plants, as well as leaves and other organic material.
Coletta said the new rules give encouragement to people interested in the technology.
“The hope is there will be more digesters built by private entities, with some built on state land,” Coletta said.
Across the state, six anaerobic digester facilities are at wastewater treatment plants and two are on farms, one in Rutland, the other in Sheffield.
One enticement is the 2014 ban on food waste and organics from the waste stream for large institutions. This should make more material available for these digesters, Coletta said.
Coletta said digesters are already widely used in Germany as a way to reduce waste and create energy.