Moon supervisors may decide tonight if they want to replace an engineering firm that township officials have accused of overcharging for work they say hasn't been completed.

The questionable bills, along with what several officials characterize as supervisors' unwillingness to hold the engineering firm accountable, prompted most of the township's top administrators to resign this year. Four, including the township manager, assistant manager, planning director and parks and recreation director, have given notice in just the past two months.

But while those administrators say the three supervisors who hired the engineer, Remington, Vernick & Beach of Haddonfield, N.J., have turned a blind eye to its questionable practices, two of the three say they will replace the firm if it doesn't live up to expectations.

"I owe that to the residents," said Moon Board of Supervisors Chairman Tim McLaughlin, who voted in January to replace longtime Moon engineer Lennon Smith Souleret Engineering Inc. of Coraopolis with the New Jersey firm. "Costs are going to be in line to get the best value for the taxpayers and the township."

Supervisors voted 3-2 to hire Remington, Vernick & Beach because its rates were lower and it waived a retainer fee. The contract, for professional services, was not put out for bid, although the township's past practice was to do so, according to outgoing township Manager Greg Smith.

Mr. Smith, who has worked as township manager for 24 years, resigned Oct. 1. Assistant township manager Jodi Noble, an 11-year veteran of the township who had been considered a top candidate to replace Mr. Smith, resigned Oct. 29. Both cited differences with supervisors over the engineering firm as reasons for their resignations, which are effective at the end of the year.

Instead of saving the township money, Remington, Vernick & Beach has cost taxpayers two to three times as much for comparable projects, and in many cases has not completed work on time for those projects, Mr. Smith and Ms. Noble said.

In a letter dated Sept. 24, Mr. Smith, Ms. Noble and planning director Scott Brilhart said engineering costs from January through August totaled $221,378 -- a 69 percent increase over the $131,332 charged by Lennon Smith Souleret for comparable work completed during the same period in 2007.

Michael Meyer, director of operations for the company's Pittsburgh office, said the managers are comparing dissimilar projects and work.

"I wouldn't agree that we aren't cheaper -- I believe we are less expensive," he said, before declining to elaborate.

Among the engineering firm's charges were inspection fees charged to developers for roads in private housing developments. Typically, developers give about $5,000 to townships to hold in escrow for them; after the township's engineering firm completes inspections of a development's public roads, it bills the township. The township then pays the fees out of escrow.

In the case of Remington, Vernick & Beach, however, the company charged for so many hours of inspections that the escrow accounts were immediately drained, township officials said. Moon officials, worried about paying the engineers' inspection fees but not getting reimbursed by frustrated developers, began sending the bills directly to the developers, according to Mr. Smith.

"Red flags went up," Mr. Smith said, when he saw that Remington, Vernick & Beach had billed the 17-lot Springer Manor development for 181 hours of inspection for the month of July. A similar 20-lot development inspected by the previous engineers, he said, incurred 106.5 hours of inspection over three years.

Mr. Smith, Ms. Noble and Mr. Brilhart, who also resigned Oct. 1, laid out their concerns in memos to the engineering firm and board of supervisors on June 19, Aug. 21 and Sept. 24. In those memos, they asked the engineers to provide documentation of the work for which the township was being billed.

The company replied in a memo that the charges were within an appropriate range for engineering work but did not provide the additional documentation.

Because of the concerns raised over engineering costs, township supervisors have sought proposals from other engineering firms.Remington, Vernick & Beach might be retained, but only if it can complete its work under budget, said Supervisor Jim Vitale, who voted in January to hire the firm.