FAIRFIELD — Overtime accounts for firefighters are 89 percent used up with 10 weeks to go in the fiscal year, and Paul Hiller, the town's chief fiscal officer, is worried.

"My big concern, if I had to look at one major concern, is fire overtime," Hiller told the Board of Finance Tuesday night. "It's the biggest one item you've got to take a hard look at. "I'm not going to sit here and say we're not going to need a significant amount of money.

"We budgeted less than the department requested, and we're going to go over what the department requested. It is probably the single most difficult deficit we face in the current year."

The Fire Department spent $1.85 million in its six overtime accounts in the 2003-04 fiscal year and had asked to have $1.72 million in the overtime accounts this fiscal year. Instead, the town budgeted $1.55 million.

As of Tuesday, the department had spent $1.37 million, or 89 percent, of the $1.55 million budgeted. The fiscal year ends June 30.

In the past, the regular payroll account for firefighters had "significant savings" that could be transferred into overtime accounts to cover deficits, Hiller said. But he doubted that would be the case this year.

The regular payroll account, budgeted at $5.8 million, was 99.75 percent used up as of Tuesday, but Hiller pointed out that this figure included projecting out salaries until the end of the fiscal year. The projected cash balance on June 30 in the regular payroll account was only $14,834.

Fire Chief Richard Felner said Wednesday that overtime money is nearly all spent according to a contract worked out between the firefighters' union and the town and that he has little control over it.

"It's not that we're spending anything foolishly," Felner said. "Ninety percent of it is contractual & and I follow the contract which was negotiated by the town."

Overtime results when firefighters are on vacation, injured, sick or attending training sessions. Felner said he didn't believe any one factor played a role in the overtime account being used up so quickly this fiscal year.

The two overtime accounts running the highest deficits are for vacancy relief and injury relief, at $77,091 and $32,249, respectively. Despite his concerns, Hiller said he believes the total town budget for the fiscal year would not end up in the red. "I'm certain it's going to net out on a positive basis," he said. "I think, overall, the budget is in exceedingly good condition on both the revenue and expenditure side."