An environmental advocacy group claims hundreds of thousands of gallons of sewage flowed into rivers and streams in the state over several years, and it's blaming the city of Danbury.
In the filing, Connecticut Fund for the Environment details a number of sewage discharges it said violate the Clean Water Act. The cases go back to 2011, and there are many.
Jack Looney, CFE's lawyer, said heavy rainfall, poorly maintained sewers, and blocked pipes Danbury should have fixed are all to blame.
"If the system was working correctly, you would have the effluent going to the treatment plant where it would be treated and then legally discharged into a receiving water," Looney said.
"[But] because of lack of maintenance, you have breaks within the system because of blockages," Looney said, "which then causes raw sewage to emanate from those blockages and those breaks into receiving waters --- where it poses not only a threat to the environment, but a threat to public health and safety."
Many of the discharges in question are so-called "bypasses," situations where there's a lot of rain and a local treatment plant can't properly cleanse all the water.
Mark Boughton is Danbury's mayor. He said no one wants bypasses to happen, but in some parts of the city, Danbury's water systems are really old. Stormwater culverts dump into sewage pipes, making bypasses unavoidable.
"We've been on a very methodical mission to remove those pipes and separate storm water runoff from the actual effluent going through there," he said.
Boughton said he's hopeful in the next two to three years the city will have done enough upgrades to, "almost make it impossible to do a bypass."
In the lawsuit, CFE also said it isn't just concerned with sewage. The complaint alleges Danbury allowed unacceptable levels of lead, copper, and zinc to seep through the system, ultimately feeding into the Housatonic River and Long Island Sound.
Boughton said the city is prepared to defend itself against the allegations, which will play out in federal court.