Town looks at way to dispose of its sludge
Citizens petition could derail initiative
GREENFIELD — The town is looking at how it might dispose of its own sludge in the future to save about $200,000 a year, but a citizens petition to stop biomass-burning plants and “all waste-to-energy facilities” could put an end to any plans before they begin.
Carole Collins, the town’s energy and sustainability coordinator, said the town has received a Massachusetts Clean Energy Center grant of $40,000, which has allowed it to study what type of facility would save the town money, while allowing it to take responsibility for its own waste and heat its transfer station.
The catch is, if the Town Council votes for the moratorium petition as it is written, the town wouldn’t be able to move forward with design or construction of such a digester until September 2014.
Currently, the town ships its heavy, wet sludge, the solids left after wastewater treatment, to plants in New Haven, Conn. and Millbury.
Town officials believe an anaerobic digester and combined heat and power facility would eliminate the costs associated with shipping the wet solids, as well as the cost to heat and provide electricity to the transfer station.
“This is not just a matter of saving money, though,” said Collins. “It is also a social justice issue. A lot of these plants, like the ones we transport to, are closing down. We really need to be dealing with our own sludge, not sending it off into other communities.”
Collins said engineering consultants will come back to the town with several options, including a small plant that would take care of only the town’s sludge and transfer station.
She said it will also come back with ideas for a large, regional facility, which would electricity into the grid and allow the town to take sludge from other communities.
“And it will also be looking at everything in between,” she said. “There are going to be lots of options.”
Collins said the goal is to find a long-term, economically viable, “green” solution to the disposal of the town’s waste water treatment sludge.
Greenfield generates 1.7 million gallons of sludge per year, which is trucked more than 100 miles away for incineration.
Collins said there is an impending state ban on commercial organic waste from landfills, which presents an opportunity to add those organics, from restaurants, supermarkets, farms and schools, as a fuel source, while mitigating harmful methane emissions from landfills.
She said an anaerobic digester would take methane and burn it to supply heat to the transfer station.
Collins said anaerobic digestion is a natural process where sludge (plant and animal waste) is broken down by micro organisms, which release the methane, or biogas, that can be used to generate heat and electricity.
“This helps cut fossil fuel use and reduce greenhouse gas emissions,” she said. “The remaining material is rich in nutrients and can be used as fertilizer.”
Collins said there is potential for the town to save a lot of money, but those figures have not been determined yet.
The feasibility study will evaluate the impacts and benefits of a proposed anaerobic digester and combined heat and power facility. While doing the study, the consultants will keep in mind the environment and the economics of such a project. She said she will have many more details when the study is complete.
Some town officials are concerned because the moratorium petition being presented to the council for a vote next month would prohibit the town from pursuing the project until late next year.
The moratorium petition says it shall apply to any biomass facility that has a capacity of more than 1 million Btus per hours, as well as all waste-to-energy facilities.