A $5.2 billion expansion of Philadelphia International Airport aimed at reducing flight delays and accommodating growth has received the final sign-off from the Federal Aviation Administration.

The FAA posted the approved "record of decision" today on its website. Construction is expected to take about 13 years and be completed in 2025.

Among the upgrades: lengthening two existing runways, and building a fifth new runway along the Delaware River. United Parcel Service would be relocated to the airport's west side, where 72 homes in neighboring Tinicum Township will be acquired by the city and demolished.

With FAA approval, the city-owned airport can begin engineering work and a final design, and seek permits.

The plan, which calls for closing Hog Island Road and the Sunoco Hog Island Wharf and relocating the Fort Mifflin Dredge Disposal Facility, is opposed by nearby neighbors in Delaware County and some environmental groups.

Philadelphia's two busiest airlines, US Airways Group and Southwest Airlines Co., have expressed concern about the cost.

Opponents, under the law, have 60 days to file litigation to try to stop the expansion. No lawsuits are pending.

The expansion will be financed by Philadelphia revenue bonds, passenger-facility charges, and federal FAA grants. Debt service on the bonds would be paid primarily by rates and charges to the airlines.

"Nobody has come up to me and said 'we are 100 percent against this,' " airport chief executive Mark Gale said, in a recent interview. "What they want to talk about is how are we going to pay for it, how are the projects going to be phased in, and what is the impact going to be for me, as an airline, on my rates and charges?"

Gale said the airport will work immediately to settle financials with the airlines. "We'll start to move out with very early project activities - bring on a program manager, begin the design work."

"There are 12 or 15 different projects that we will work on concurrently, and probably not do any heavy construction activity for at least two years," he said. "In order to put the runway in, we need to move UPS."

Gale said a lot of negotiation must still be done, and the airport is not looking to knock down homes soon.

"We do not have eminent domain power. We are going to try to voluntarily have a transaction with a willing seller. If that happens, and I have a place to put UPS, then all the other things will start to come into play. That could take years," Gale said.

"We could have an agreement with a homeowner that we will buy their home, but not take control of the property for another two or three years. We have that much work to get out of the gate. We are trying desperately to move UPS and keep them at Philadelphia airport. Those discussions are still ongoing."

The FAA says there is precedent for a major airport to acquire homes and businesses for expansion.

Chicago's O'Hare International Airport bought 2,500 homes and 150 businesses in recent years to build a new runway. Chicago area property owners were paid the "fair market value" of their homes based on appraisals, and were helped with moving expenses, and utility hookups.

The FAA, which conducted environmental studies and held public meetings in Philadelphia between 2003 and 2008, chose the proposal, dubbed "Alternative A," for several reasons, including the possibility of avoiding or minimizing "significant" environmental impact.

Still, enlarging the airport footprint will cause the loss of 81.7 acres of wetlands, including marshes and open water on the airport; 46.7 acres of wetlands within the former Philadelphia Water Department sludge lagoons; and 23.1 acres of waterways. The plan will require 24.5 acres of fill in the Delaware River to construct a new runway, the FAA said.

Noise levels will increase in some residential areas and decrease in others. Eighty businesses, or about 3,300 jobs, would be uprooted in Philadelphia north of the airport, and to the west in Delaware County. The Interboro School District would lose about $1.8 million in real estate taxes annually.

On the other hand, 2,880 new on-airport jobs would be created, along with 3,700 construction-related jobs annually during the project, the FAA said.

The plan requires that the airport put in place "mitigation" measures, including reducing noise from construction, routing construction vehicles to nonresidential streets, and installing sound insulation for affected neighbors.

The expansion must protect air and water quality, as well as habitats of wildlife species, such as red-bellied turtles.

The city sees expansion of the airport as important for the region. "If we don't do these improvements, we will be locking ourselves into continued delay problems," Gale said. "We will not be able to grow and gain the capacity that we need to handle the traffic that we believe is coming our way."

Flight delays in Philadelphia averaged 10.3 minutes per takeoff and landing in 2003, and are projected to increase to 19.3 minutes per flight by 2025, the FAA said.

With an expanded airfield and a new runway, delay time would be cut to 5.2 minutes in 2025, the agency said. Airports are considered severely congested when the average delay exceeds 10 minutes.

Philadelphia is the fourth most delayed airport in the nation, partly because of the configuration of the airfield. The close spacing of Philadelphia's two primary east-west runways means there cannot be simultaneous aircraft arrivals and departures in poor weather. In good weather, the FAA permits less separation between arriving and departing planes.

Philadelphia is situated in the nation's most congested airspace, shared with New York and Newark, N.J. The airport expansion does not change the use of airspace - the direction planes land or take off. Aircraft will continue to use current entry and exit points, the FAA said.

Studies show that the airport generates $14.4 billion in economic activity annually.

Constructing a new runway will affect the Delaware River, the FAA said. The west end of the runway would extend into the river 670 feet and be built on fill or piles. To reduce impacts to the river, the FAA said an area of flaked block concrete will be built as a cushion.

Under the plan, an automated people mover will be built and serve all existing and planned terminals, and eventually parking lots. Rental car centers will be consolidated in one 4,000-parking-space facility, which would house van services, shuttles and SEPTA.

Parking garages A, C, and D will be enlarged, with the addition of 3,500 spaces. The economy parking lot will add 100 spaces.

The record of decision can be found on the FAA web site at: http://phl-cep-eis.com/