VERGENNES — Unseasonable rain that fell in Vermont during the weekend before Christmas led to the release of more than 2 million gallons of untreated and partially treated wastewater into rivers around the state.
Brandon, Montpelier, Rutland, St. Albans and Vergennes all reported combined sewer overflows to the state’s Department of Environmental Conservation. St. Albans also released more than a half million gallons of partially treated wastewater and stormwater. By law, Vermont municipalities are now required to submit public alerts of untreated releases.
State officials could not be reached for comment on the discharges.
In Vermont, 14 cities and towns have combined sewer systems that treat both wastewater and stormwater. Combined sewer systems have relief valves that open during periods of high rain to prevent wastewater from backing up into homes and streets.
The untreated water, which is 95 percent stormwater, spews out from outfall pipes into rivers and lakes, leading to levels of bacteria in nearby waters that stay elevated for 48 hours. Those releases, called “combined sewer overflows,” are not a large source of phosphorus pollution.
Wastewater treatment systems around the country are required to have permits that regulate their releases into streams or lakes. The state has been working with municipalities to reduce combined sewer overflows, and the total number of outfall points around the state has been reduced from 178 to 53. Vermont adopted a new combined sewer overflow rule in 2016 that said regulators must require municipalities to submit plans to eliminate or treat overflows when they issue new permits.
The wastewater treatment upgrades needed to reduce combined sewer overflows and meet other water quality requirements are expensive and will take years to complete. During a legislative committee meeting this September, public works directors from Burlington and Rutland said that completely eliminating the combined sewer overflows is financially impossible.