Waterford — The Utility Commission neglected to charge meters at four properties, including Crystal Mall, for sewer service as far back as 2009, resulting in $128,000 in back charges.

Chief Engineer Neftali Soto said Wednesday that the mishap may have stemmed from a 2009 change in the billing system from a flat rate to bills based on meter size and consumption of water.

"It was missed. Somehow, it was missed," he said.

He said the commission is still looking for unbilled meters.

Crystal Mall owes the commission $85,000; Our Lady of Perpetual Health church owes $4,800; a residence at 15 Oil Mill Road owes $60; and property at 48 Boston Post Road owes $38,000, according to a memo Soto released to commissioners during a public meeting Tuesday.

The mall and the Boston Post Road property haven't been billed since 2009, according to Water Pollution Control Authority Survey Party Chief Fred Lathrop.

Commissioners said the Boston Post Road property is a shopping center, and Google Earth shows the address as being located in the Waterfall Shopping Center owned by Silverman Realty. The website for the realty company, however, lists the address of the center as 40 Boston Post Road.

At each location, only a portion of meters did not get billed. For example, the commission still billed the mall for eight meters.

"Somebody who's paying eight out of 11 meters, they think that they're paying their bill," Commissioner Rodney Pinkham said at the meeting Tuesday.

Soto was informing properties about the charges Wednesday, according to Town Attorney Nick Kepple.

Property owners and residents did not return calls for comment. A man who identified himself as an employee of the owner of the shopping center said, "All I was told to say is, they don't have a response because they have no idea what's going on."

Lathrop discovered that there were unbilled meters in January while conducting a quality assurance and quality control evaluation of Waterford properties that receive water from the Water and Water Pollution Control Authority in New London. The meters are also used to measure water use.

Nine thousand properties in Waterford receive water service from New London, according to Lathrop. Waterford covers sewer service for the properties. The commission has 7,000 sewage customers, according to Soto.

Lathrop said that to conduct his evaluation, he manually matched data from the WWPCA's database for water users with Waterford's database for sewage users.

Soto said that in 2009, when Waterford changed its sewage billing system, it created a new database. Lathrop said he did not have log-in information for Waterford's old database, in part because he didn't begin helping the commission with billing until 2009.

The switch could have caused some meters to fall off the map, said Soto. He said another possibility is that new meters were added and no one informed the Utility Commission.

Lathrop said that he learns of new meters through the town's Building Department.

Soto said at the meeting Tuesday that New London is not at fault for the commission not billing the meters.

The customers who owe back charges have the option of selecting a payment plan.

"We're humans. We're not going to say, you owe us that and it's due tomorrow," said Soto.

Kepple and the commission discussed on Tuesday how legal recourse might work in the case of a dispute between the customers and the commission. One factor that may require negotiation is interest rates should customers request to pay the debts over time.

"Litigation can sometimes afford more flexibility in how the debts are paid," Kepple said Wednesday.

t.townsend@theday.com