Greater New Bedford Refuse District pursues waste-to-energy project

Mass Innovations, From The Beacon, June 2013

The Greater New Bedford Refuse District and a local energy company, backed by $400,000 in state grants, are planning to set up a large-scale program that will divert food waste and other organic matter from the local landfill and convert it to energy.

The food and other organic waste, such as sewer sludge, will be converted to energy using a process called anaerobic digestion.

The Clean Energy Results Program grants were obtained a few months before the Department of Environmental Protection issued a solid waste master plan that aims to reduce the waste stream in Massachusetts by 30 percent by 2020. To achieve that goal, state officials are counting on the diversion of sizable amounts of food waste to anaerobic digestion and other options.

The Crapo Hill landfill, which has been in operation since 1995, receives waste from New Bedford and neighboring Dartmouth as well as commercial solid waste brought in by various haulers. Commonwealth Resources Management, which already manages a small landfill-to-gas plant at the landfill, would significantly expand its gasification process, according to Scott Alfonse, executive director of the Greater New Bedford Refuse District.

The waste stream that would be converted to energy would include fats, oils, grease and other food wastes as well as sludge from wastewater treatment plants, according to Alfonse. Those materials would be delivered to the plant in a liquefied form and placed in a storage tank before entering the digester.

“With a heat source, it is digested, and as it is digested, that gas builds up,” eventually being used as a power source, Alfonse said.

The remaining waste product, known as digestate, could be introduced into the portion of the landfill that is already capped, as a means of speeding up the process by which methane gas is produced, Alfonse said.

The pilot phase of the project, which will be reviewed by the Department of Environmental Protection, is expected to get under way at some point next year, according to Alfonse.

“The goal is to keep the capacity we have for as long as we can for those wastes that have no other way of being managed – they can’t be recycled, they can’t be composted, they can’t be digested,” Alfonse said.

Dartmouth Executive Administrator David Cressman also emphasized the importance of extending the landfill’s life. He noted that Dartmouth is home to several large institutions, including a campus of the University of Massachusetts and the Bristol County House of Corrections, that generate large amounts of food waste.

For more information, contact Scott Alfonse at (508) 763-5924.