ATTLEBORO - A move to review, and possibly change, the amount the city charges to the independent water and wastewater departments for various services has generated some false information, an administration official says.

Barry LaCasse, the city's director of budget and administration, said talks under way in the council's committee on budget and appropriations to review what is known as "the indirect rate" has prompted some residents to believe the city is "double-dipping" when it charges the two departments about $500,000 each or almost $1 million in total for services they can't provide for themselves.

"That's a serious misconception," said LaCasse, who said he was speaking for Mayor Kevin Dumas.

"Double-dipping" would occur only if the city charged the two departments for services that it had already raised tax money to cover, he said.

LaCasse said money raised by taxation under the state's Proposition 2 1/2 tax-limiting law does not cover water and wastewater expenses when they are independent departments. Those expenses come as an addition to the city's yearly budget and do not drive up the amount the city is allowed to raise, so the city has to charge for them, he said.

The water and wastewater departments are enterprise departments, meaning they support themselves with water and sewer fees and have budgets separate from the city's main budget.

The system by which money is paid to the city is authorized and governed by the state's Department of Revenue and is required to meet certain standards, LaCasse said.

"DOR requires every municipality to have a written policy and a reasonable calculation," he said.

In the city's case, the calculation is formulated periodically by a firm that specializes in that work.

The percentages to be charged were last calculated in 2005 by Maximus Inc. in a 147-page study.

It was at least the second time the city has used the firm, and was first hired by former Mayor Judith Robbins, LaCasse said.

"There's absolutely no guessing on amounts," LaCasse said. "It's the result of a comprehensive evaluation and study by professionals who do this on a day-to-day basis."

Meanwhile, the mayor is willing to go along with another study, if it's the desire of the council, LaCasse said.

"We absolutely stand committed to work with the council to re-examine the indirect rate, and if they want to commission Maximus or another company that does this kind of work, that's fine," he said. City Councilor Bill Bowles, the Democratic candidate for state representative in Attleboro, has suggested the "incremental cost method" be used, and LaCasse said the administration is willing to try it "if it's reasonable and meets DOR criteria."

While Bowles has said the indirect rate may be too high, he'll abide by whatever the accounting evidence shows.