New London ― In 2004, the city began sending letters to residents asking them to disconnect any illegal sump pump connections out of concerns that discharge from such hook-ups could overwhelm and harm the municipal sewer system.

“We were getting a lot of rain ― a crazy amount ― and all the added flow from sump pumps to outflow lines and street mains were leading to back-ups and flooding,” Barry Weiner, chairman of the Water and Water Pollution Control Authority said on Friday. “And here we are, 20 years later, and we’re getting even more rain and the flows are off the charts.”

To combat the issue, the WWPCA on Thursday ― three months after an overwhelmed by-pass line created several residential sewage back-ups ― formed a new subcommittee to brainstorm ways to educate residents on the danger of incorrectly installed sump pumps.

Sump pumps are the home version of a ship’s bilge pump, preventing rising water from flooding basements. When installed correctly, the pumps divert rainwater into a yard.

But problems arise when homeowners connect those sump pump hoses into residential outflow lines that dump into the main street sewer pipes and eventually discharge into a wastewater treatment plant.

Keeping treatment “bugs” fed and prolific

One problem is the amount of increased strain such incorrect connections put on infrastructure.

“In a normal situation, our system handles up to nine million gallons of flow per day,” Weiner said. “Heavy rains ― and sump pump ground water ― can increase that up to 18 million gallons.”

And it’s not just the amount, but also the type of water making its way through sewage pipes that’s concerning, said Public Utilities Director Joseph Lanzafame. He said a city treatment plant is a finely-tuned biological system in which microbes “eat” and break down wastewater components.

“But if that water coming in is mixed with rain and sump pump water, it dilutes the flow,” Lanzafame said. “And the bugs that aren’t washed out can’t get enough food to do their job and die off.”

Two decades ago, the city used $20,000 in grant money to convince 99 residents to reverse their illegal sump pump connections. Homeowners alerted to the incorrect installations paid plumbers or contractors to fix the issues, submitted the work bills and were reimbursed, Weiner said.

It’s unclear how many illegal sump pump connections remain in the city.

“Our subcommittee this time is going to take a multi-pronged approach that will again include educating the public of the issue and enlist their cooperation in fixing the problems,” he said. “We’ll also look to see if there’s another incentive program we can offer. We can’t stop the rain, but we can work on the sump pumps.”

A March 4 letter to WWPCA members included an opinion from city attorney Brian Estep, who stated he believed the city had the right to inspect the properties of owners who availed themselves of the original sump pump reimbursement program to ensure the disconnections are still intact.

Lanzafame noted improper sump pump connections are not a New London-centric issue, but one that plagues municipalities across the country.

“That education piece is very important,” he said. “I don’t think people really understand how damaging that sump pump water is to a treatment system.”

j.penney@theday.com