MONTPELIER — Officials estimate that the second phase of an upgrade to Montpelier’s wastewater treatment plant will reduce the plant’s greenhouse gas emissions by around 2,000 metric tons per year by using methane from the solid waste to power the plant’s operations.
The project’s first phase, which took place in January 2020 and cost $14.4 million, allowed plant operators to filter out solids from organic waste and process them in an anaerobic digester, which uses bacteria to generate power from organic waste.
Wastewater treatment facilities have long struggled to dispose of the solid wastes that they filter out during the treatment process. Some of the sludge contains chemicals that pose a challenge to using the material as a fertilizer or in other ways.
Since the most recent upgrade, the plant has been “accepting high-strength organic waste, which can include brewery waste, dairy waste, Cabot, Ben and Jerry’s fats, oils and greases from restaurants, glycol,” said Chris Cox, chief operator at Montpelier’s Water Resource Recovery Facility. “Anything that’s very high in organics, we want.”
A final product, which looks like wet, black dust, is transported to Vermont’s only landfill in Coventry and treated as waste.
In phase two, officials plan to further refine those solids to create a drier product that could, theoretically, be used as fertilizer or for other purposes, according to Cox. The process of further refining the solids would reduce the amount of sludge by 65% and produce more energy, Cox said.
The goal of the project is “capturing more energy from the organics that we take out of the wastewater stream,” he said.
Cox said city officials are still in the planning stages for the project, and will soon sign the final design contract. The design process will take around one year, and officials expect the implementation process to take at least 18 months after that.
Phase two will be funded by a $16 million loan from the U.S. Department of Agriculture — which Montpelier voters have already approved — along with a $3.5 million grant from the department and a $3.2 million grant from the state’s Department of Environmental Conservation.
The funding also includes $7.2 million for work on East State Street in Montpelier, where new water and sewer mains will be installed. The upgrades are designed to help reduce combined sewer overflows, which occur in systems that handle both sewage and stormwater when heavy rains cause the untreated effluent to overflow into local waterways.
“The city spent 20 years separating the storm out of the sewer to reduce the frequency of those events,” said Kurt Motyka, head of Montpelier’s Department of Public Works. “And this is one of the last really big drainage areas that contribute to the sewer main, so we do expect a very significant reduction in the frequency of overflow events.”
Nationally, USDA Secretary Tom Vilsack announced more than $285 million in critical infrastructure funding has already been dedicated to combat climate change and expand access to clean energy. The project is one of 844 projects across 46 states to be funded by the Rural Energy for America Program.
In fiscal year 2023, $300 million will be available from the program funding, $250 million of which was made possible by President Biden’s historic Inflation Reduction Act.
In Montpelier, officials gathered on Tuesday to celebrate the project, which City Manager Bill Fraser said was approved by voters by a wide margin.
Neil Kamman, director of the state’s Water Investment Division, said officials at the USDA and at the state are ready to help other municipal officials who may feel daunted by a project that costs tens of millions of dollars.
“It benefits everybody all the way through, ultimately — the ratepayers that have lower rates in order to have higher quality infrastructure, back to a better functioning facility, which supports climate goals and clean water goals, back to the people that are actually building the amazing pipes and valves,” he said. “It’s just super important work.”
