VERGENNES — Weather extremes late last week — heavy rains, warm temperatures that melted existing snow, and then a hard freeze — triggered overflows to municipal sewer systems around Vermont, notably in Vergennes, St. Albans and Rutland.
All plant operators are required to report combined sewer system overflows to the Vermont Department of Environmental Conservation (DEC). That’s because the overflows are mostly storm water after weather events such as those last week, but also contain septic waste.
According to the DEC website, seven systems reported overflows between 9:05 a.m. and 10:33 p.m. on Friday or between 2 a.m. and 12:54 p.m. and Saturday.
St. Albans and Vergennes experienced the largest overflows. DEC officials had yet to verify as of Wednesday morning the exact size of the St. Albans overflow, but it was listed as more than a million gallons at 9:15 a.m. on Jan. 12.
The Vergennes plant reported 743,600 gallons running into Otter Creek at 9:59 a.m. on Jan. 12.
Rutland’s system reported the greatest amount overall, 753,000 gallons in a half-dozen separate incidents on Friday and Saturday.
Middlebury experienced two smaller overflows, both between 1,000 and 10,000 gallons, both on that Friday morning. Also reporting overflows were Montpelier, Wallingford and Lunenberg.
Vergennes has been operating for decades under state orders to work on its overflow problem. The city has taken steps, including creating a monitoring system to determine the extent of the problem and to report it accurately.
City officials believe replacing clay lines that make up a yet-to-be determined percentage of the city’s collection system will go a long way toward solving the problem. An ongoing study is mapping the system, with the results due early this spring, and should allow to start planning for a fix.
Officials also are continuing to work to make a pump station on the far side of Otter Creek from the wastewater treatment plant more efficient. That station backs up during severe weather and causes the overflows.
Officials say a variety of wipes that consumers flush into the system also clog the station, which serves a large portion of they city’s population, and the clogging problem becomes worse during major weather events, just when the station must operate at full capacity.
Vergennes City Manager Mel Hawley has said a bond to pay for a major project probably lies in the city’s future, but that it is too early to say how much such a project might cost.