About 150,000 gallons of untreated wastewater has discharged into the Naugatuck River in Seymour from a broken manhole.
The manhole collapsed on Christmas Day.
Emergency responders from Veolia Environment North America arrived on the scene at 1 p.m. Wednesday and found the manhole structure had partly collapsed, sending debris to the bottom of the manhole and blocking the flow of untreated wastewater to the Seymour Wastewater Treatment Plant. The company is contracted by Seymour for the town's water treatment plant.
The manhole provides access to an underground pipe that carries wastewater underneath the Naugatuck River. The treatment plant has not been affected and continues to treat wastewater.
According to the Department of Energy and Environmental Protection, the spill is significant, but it had been slowed to just 4-5 gallons per hour on Friday.
Margaret Miner, executive director of the advocacy group Rivers Alliance of Connecticut, says the sewage is toxic and could harm the river.