Originally published Jan. 5, 2011: A $5.2 billion expansion of Philadelphia International Airport aimed at reducing chronic delays and accommodating growth 50 years from now has received the final sign-off from the Federal Aviation Administration.

Philadelphia is in the most heavily traveled airspace in the nation, and the airport's airfield configuration, with closely spaced runways, has led to delays in poor weather.

Among the upgrades: lengthening two runways, building a fifth runway along the Delaware River, a new commuter terminal, more gates, additional parking, an automated "people mover," and a ground-transportation hub for rental cars.

United Parcel Service would be relocated to the airport's west side, where 72 houses in neighboring Tinicum Township would be acquired by the City of Philadelphia and demolished.

With the FAA's approval, the city-owned airport can now begin a two-year process of engineering work and a final design, getting permits and acquiring land.

Situated on 2,300 acres just seven miles from downtown, Philadelphia airport has limited options for growth, sandwiched between rivers, highways, and a national wildlife refuge.

The expansion will not solve the gridlock of congested East Coast airspace, but it will provide passengers with the "comforts and amenities they find at other airports today, and the ability to move in and out of Philadelphia more efficiently and without major delay," said airport chief executive officer Mark Gale. "This has been long awaited."

After a decade of planning and study, and seven years of environmental review, the FAA posted a "record of decision" on its website Tuesday. Construction is expected to take about 13 years and to be complete in 2025.

Not everyone likes it, including neighbors whose houses are to be acquired and demolished, and some environmental groups.

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

"We continue to meet with our airlines and talk about the path forward," Gale said. "While the airlines may be concerned about some costs, I don't have anybody who has come to me and said they are standing in opposition."

In 2009, Philadelphia International handled 472,668 takeoffs and landings and about 30 million passengers. That is projected to increase to 60 million by 2030. Philadelphia is the ninth-busiest U.S. airport but the seventh-most delayed.

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

Gale said the airport would work immediately on financial details with the airlines. Discussions are also ongoing with UPS, he said. "We do not have eminent-domain power in Delaware County. We will try to voluntarily have a transaction with a willing seller," he said.

Once agreements are reached with homeowners, the airport may not take control of the property for two or three years, Gale said. "We have that much work to get out of the gate. We are trying desperately to move UPS and keep them at Philadelphia airport."

Opponents have 60 days to file litigation to try to stop the expansion. Tinicum Township recently lost a federal lawsuit to prevent the airport from buying property in Tinicum without the township's consent.

There is precedent for an airport to acquire residential and commercial property to expand.

Chicago's O'Hare International Airport bought about 500 houses and apartments and 100 businesses from 2002 thorough 2010 as part of an airport modernization that included a new runway and improvements to existing runways.

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 plan, 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 airport property. An additional 46.7 acres of wetlands in the former Philadelphia Water Department sludge lagoons will be altered to relocate part of the Fort Mifflin Dredge Disposal facility. Also affected will be 23.1 acres of waterways, the FAA said.

The plan will place 24.5 acres of fill in the Delaware River to construct the new runway. The runway's west end would extend 670 feet into the river and be built on fill or piles.

"It's bad precedent," Delaware Riverkeeper Maya van Rossum said, noting that part of the river is used by important species, including the Atlantic sturgeon. The runway would be near a proposed Southport marine terminal and not far from the main navigation channel, which is being deepened 5 feet to accommodate larger ships. "You are hitting the same ecosystems, the same reach of the river, over and over again, exacerbating the harms of each one of the projects," van Rossum said.

The FAA acknowledged that noise would increase in some residential areas and decrease in others.

Eighty businesses, which employ about 3,300 people, would be uprooted in Philadelphia north of the airport and in Tinicum Township. The FAA said many of the businesses, which depend on the airport, would likely relocate. The Interboro School District will lose $1.8 million annually in real estate taxes because of property acquisitions.

The FAA said 2,880 on-airport jobs would be created, along with 3,700 construction-related jobs a year during the project.

The plan requires the airport to implement "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 such as the red-bellied turtle.

"From what we've seen and discussed, plans were to create other wetlands, or protect other areas, outside of the airport that would mitigate," said Gary Stolz, manager of the John Heinz National Wildlife Refuge near the airport.

"There are potential good things that could come out of this for wildlife," Stolz said. "There are some open spaces - a 100-acre piece of property in the Eastwick area - that has the potential to be protected and restored. Maybe there's a positive thing that can come out to make up for some losses."

Mayor Nutter said the expansion was "critical" to the economic health and growth of the region and "will create thousands of jobs. Philadelphia International Airport is the economic engine for all of Southeastern Pennsylvania," Nutter said.

"The fact that this entire process took a decade to complete underscores its thoroughness in carefully exploring all the alternatives."

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

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

Philadelphia is the nation's seventh-most delayed airport, in part because of the close spacing of the two primary east-west runways - and the limited number and length of other runways - which preclude simultaneous aircraft arrivals and departures in poor weather. In good weather, the FAA permits less separation between arriving and departing planes.

Under the plan, which calls for closing Hog Island Road and the Sunoco Hog Island Wharf and relocating the Fort Mifflin Dredge Disposal Facility, an automated people mover would transport people between terminals and parking lots. Rental-car facilities would be consolidated in one 4,000-parking-space transportation center.

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