Officials at Phoenix Sky Harbor International Airport estimate that this month's terrorism threat already has cost more than $200,000 in unanticipated Homeland Security costs.

Most of the money has gone for overtime and related expenses for police officers, contracted on-site security and additional staffing.

And while city officials are hopeful that they will be reimbursed for most or all of the costs, they fear there won't be money to repay them for future expenses, especially now that the federal government has dropped Phoenix to the bottom of its Homeland Security funding lists.

The added costs started accruing Aug. 10, when British officials announced they had foiled a plot to use liquid explosives to blow up airliners flying from the United Kingdom to the United States.

In response, the U.S. Department of Homeland Security banned all liquids and gels from carry-on luggage and immediately raised the national threat level.

It was upgraded to orange, or "high" risk for terrorism attacks, on all domestic flights, and to red, or "severe" risk, for flights arriving from the United Kingdom, although that level has since been reduced to orange as well.

That action forced Sky Harbor to immediately begin implementing new security measures, and these are costing the airport $15,000 to $20,000 a day, officials estimate.

The costs are expected to continue until the federal government lowers the threat level back to yellow, or "elevated."

Transportation Security Administration spokesman Nico Melendez said his agency couldn't speculate on the length of the heightened alert, but most industry officials believe it's likely to be at least through next month's anniversary of the Sept. 11, 2001, attacks.By then, the local tab could exceed $500,000.

Phoenix officials say they can seek reimbursement from a variety of federal funds and grants. But the longer the threat level is elevated, the less likely it will be that they are fully repaid.

According to Marcus Aurelius, the city's emergency management coordinator, one of the primary sources of funding is the Urban Area Security Initiative. But the money is allocated to the entire Maricopa County region on a two-year cycle by the federal government, meaning that as many as 20 communities have to share it.

Aurelius estimates there is just under $700,000 available for use in this situation.

"We are watching the math pretty closely," Aurelius said. "It's not going to take us but a couple of weeks to go through that amount of money. If another episode provokes us to going back to a higher level . . . then we won't have money to reimburse what we spend."

An even bigger problem looms, local officials say.

The federal government announced in June that it was dropping the Phoenix area to the bottom of the funding list and doling out $3.9 million in Urban Area Security Initiative grants, instead of the previous $10 million.

That means there will be virtually no contingency funds to reimburse Sky Harbor should the threat level be elevated again in the coming years, Aurelius said.

Phoenix officials say that if they don't get fully reimbursed, they probably would cover the shortfall with operating funds or ask the City Council to allocate contingency dollars for the expenses.

The airport is one of only a few city departments that is self-funding; Sky Harbor gets money from the fees it charges to airlines and to passengers who fly there, so it's unlikely that using operating monies will result in service cutbacks elsewhere.

Still, officials said, something needs to be done about a system that often leaves cities in the lurch when it comes to paying for items related to Homeland Security.

"It's something that really needs to be revisited," Assistant Aviation Director Carl Newman said of the repayment process. "We react very quickly, but it's a federal issue, and they do need to come up with a better system."

Reach the reporter at ginger.richardson@arizonarepublic.com or (602) 444-2474.