Stonington — Water Pollution Control Authority members agreed Tuesday night to continue discussions with North Stonington officials about sending some of its sewage to the Pawcatuck treatment plant but indicated the buy-in fee will have to be much more than the $1 million being offered.

Members also expressed frustration that in previous discussions over the years, North Stonington had not responded to counter offers. Still, they said they would be willing to try to come to an agreement.

North Stonington First Selectmen Michael Urgo sent a letter earlier this month to First Selectman Rob Simmons, saying his town was willing to pay Stonington $1 million to send 100,000 gallons a day of sewage to the plant, half of what he said his town was promised when Stonington extended sewers to the town line about 30 years ago.

Urgo requested a response by the end of the month. If Stonington is not interested in taking half of the flow, he wrote that North Stonington would have to move forward in another direction, as providing infrastructure to its prime commercial zone is a high priority budget item this fiscal year. There were no North Stonington officials at Tuesday night’s WPCA meeting.

Authority Chairman Richard Cody, an attorney who negotiates such intermunicipal agreements, said that coming to an agreement is much more complicated than saying give us a million dollars and you can connect. He said the two sides will have to discuss not only the initial buy-in fee, but issues such as a premium surcharge on North Stonington sewer users and how to have North Stonington help offset the cost of future repairs to the system.

Authority member Lynn Young said that it has cost Stonington taxpayers $3.6 million to build the infrastructure for the 200,000 gallons that North Stonington had been offered but never took advantage of. With North Stonington now wanting to use 100,000 gallons, she and other authority members said the buy-in fee should be more like $1.8 million.

“If they can improve their offer substantially, then I’m interested,” said Young, who is also on the Stonington Board of Finance.

She was also concerned about allowing North Stonington to tie in to the system because its properties along Route 2 are more desirable to developers than those in Stonington, if they have sewer service. If development occurs in North Stonington and not Stonington, Stonington taxpayers would lose out on tax revenue, she said. Some of the Stonington land in question has sat vacant for years, though, in part because it contains ledge and power lines.

WPCA Director Douglas Nettleton said that he recently has received two calls from developers planning large projects in North Stonington but who need sewer treatment to build them.

“It won’t take them long to get to 100,000 gallons, based on the calls I’m getting,” he said.

Earlier in the meeting, authority members discussed the need for more revenue to make needed repairs to the town’s existing sewer system and treatment plants and the possibility of raising rates for customers.

Cody pointed out that by coming to a deal with North Stonington, the town would not only receive the buy-in fee but also sewer use fees from North Stonington would provide much-needed revenue over the long term.

“If no development occurs (in Stonington) — over the next 10 years, we could have had that money" from North Stonington, Nettleton said.

j.wojtas@theday.com