Airport ’99: As traffic increases, so do maintenance requirements

If there is one thing that can be said for certain about municipal airports, it is that maintaining them is anever-ending job. Ongoing maintenance — particularly involving runways, taxiways and lights — is needed to handle the nonstop traffic.

Aside from the routine duties — patching, painting, lubricating, replacing worn parts — maintenance involves such disparate responsibilities as keeping birds off the runway area; training and equipping emergency response crews for fires or accidents; formulating a coordinated snow storm response plan; monitoring runoff from deicing and cleaning solutions; and keeping runway lights functioning properly.

All of that must be accomplished while the planes — and people — come and go. “Airports are expensive places to maintain. There is such high-density usage,” says Ginger Evans, national director of aviation services for the Denver office of Carter & Burgess, Fort Worth, Texas.

According to projections from the Federal Aviation Administration (FAA), airport usage in the United States will double to more than 900 million people per year by 2010, making maintenance all the more critical. “If you look into the future, passenger traffic is only going in a straight line upward,” says Gerald Fitzgerald, president of Parsons Brinckerhoff Transportation in New York. He adds that, depending on a maintenance crew’s effectiveness, an airport can become a drain on resources or a vital cog in the wheel of economic activity.

Maintaining pavementIf aircraft do not have well-maintained surfaces for landing and takeoff, virtually every other aspect of maintenance becomes a moot point. Thus, tasks such as patching potholes, sealing cracks, repairing concrete joints and resurfacing with asphalt are of paramount importance — particularly from a safety standpoint. “You’ve got this tiny aircraft tire with this huge weight on it. Your psi (pounds per square inch) goes through the roof,” Evans says.

“Most airports, even big ones, use fairly low-tech paving,” says Richard Marchi of Airports Council International, a Washington, D.C.-based trade and lobbying organization. There are exceptions, such as a test strip at Chicago’s O’Hare Airport that features electrically conductive asphalt containing synthetic graphite made by Chicago-based Superior Graphite. Not only does the asphalt warm up to melt snow and ice (at a high cost for the electricity), but, by minimizing drastic temperature changes, it could reduce cracks and potholes. “Basically, the technique works, but the cost/benefit equation has not been resolved yet,” Marchi says.

Airports that handle major commercial airliners generally have runways made with reinforced concrete — in some cases 17 inches thick, says John MacMullen, professional development manager for the American Public Works Association (APWA), Kansas City, Mo. However, small airports outnumber the large ones, and asphalt is used more commonly at the small ones because it costs less than concrete and can support the relatively lightweight aircraft. More than 90 percent of the runways in FAA’s database are asphalt.

Although aviation officials recognize the importance of consistent pavement maintenance, some of them may not do much about it. A recent Government Accounting Office (GAO) study questioned the nation’s runway maintenance track record. The study found that about three-quarters of the runways in GAO’s database were in good to excellent shape, and 26 percent were rated from fair to poor. Unfortunately, runways in that 26 percent have reached or surpassed the point at which they can be rehabilitated economically, GAO says. Small airports, often those faced with severe budgetary constraints, may be most likely to struggle in keeping up their maintenance, Marchi says.

Computerized pavement management systems, which help ensure adherence to regular maintenance schedules, have become much more common at airport maintenance departments during the past three or four years, Evans says. Micro PAVER, public domain software offered by APWA, offers tools such as a database, a PCI (Pavement Condition Index) calculator, graphics, photo storage and a budget estimator. It is used at Tampa (Fla.) International Airport and at airports in Reno, Nev.; Memphis, Tenn.; and other cities.

Time crunchWith airports getting busier all the time, finding enough “down time” for crews to work can pose a challenge. “You’re always going to be restricted to a fairly narrow window of time,” Evans says. She notes that major hubs already have “maxed out” their peak hours for arrivals and departures, and, when they add flights, they must schedule them for the slower hours. That cuts into precious maintenance time.

Consequently, as is the case with highway maintenance, runway maintenance and repairs often are done in the middle of the night when air traffic is minimal. “Many airports start [runway maintenance] at 11:30 p.m. or midnight and stop at 4:30 a.m.,” Marchi says.Nighttime construction can be costly, because crews must move lights, construction equipment and portable generators on and off the runway in a few hours, sometimes for several consecutive nights. Additionally, factors such as weather and availability of nighttime personnel affect runway maintenance strategies.

At Tampa International Airport, individual runways are closed each month for visual inspections lasting an hour or two, says Larry Smith, director of facilities for the Hillsborough County (Fla.) Aviation Authority. Staying on top of maintenance needs enables the airport to avoid costly concrete rehabilitation, he notes.

Like many other airports, Tampa International uses the PCI rating system to evaluate sections of pavement. The PCI, which is used by the GAO but not the FAA, consists of a rigorous visual inspection of pavement surfaces for signs of deterioration. It is based on a scale of 0 to 100, and the numeric rankings are clustered into seven categories: excellent, very good, good, fair, poor, very poor and failed.

Employing a far different strategy than that used by Tampa International, Dallas-Fort Worth Airport took the unusual step of shutting down a runway for a 12-day rehabilitation. But, before the project could get under way, it took nine months for 15 parties (airlines, maintenance crew, fire department and others) to reach a consensus on when to close the runway and what the project’s time frame would be.

Other maintenanceAside from pavement, airports have many other components — both inside and outside the terminal buildings — that require maintenance. Many are electrical, such as gate display monitors, baggage location displays and lighting systems.

“Airfield lighting is an area that requires constant vigilance and maintenance,” Evans says. Fortunately, that job is made easier by monitoring software, which keeps track of replacement schedules and alerts maintenance personnel to interim problems.Some types of maintenance, such as snow and ice control on the runways, taxiways and gate areas, are seasonal and regional. Last month, officials at Detroit Metro Airport learned the hard way what can happen when a snowstorm hits a major airport that is unprepared. After a foot of snow blanketed southeastern Michigan on Jan. 2, the nation’s 10th busiest airport remained in a state of chaos for several days.

Some 64 pieces of equipment were used to remove the snow from more than 2 million square feet of pavement, according to The Detroit News. And, despite keeping two runways open during the storm, crews failed to clear snow and ice from many gates. Some of the passengers, who were stranded in aircraft parked on the tarmac for up to 10 hours in subzero conditions, have filed suit against the airport, Wayne County and Northwest Airlines.

In addition to plowing and hauling away snow, maintenance crews at northern airports must incorporate anti-icing (before-the-fact prevention) and deicing (after the fact) into their ice control programs. Anti-icing materials — solutions such as sodium acetate used for runways, sidewalks and roadways — must be certified by the FAA for flashpoint, storage stability and corrosive effects to aircraft and pavement.

Anti-icing and wing deicing materials (such as propylene and ethylene glycol) create runoff, another maintenance concern. In most cases, National Pollutant Discharge Elimination System stormwater permits are needed for such runoff, particularly if it discharges directly into a waterway. When the discharge goes to a municipal wastewater treatment plant, a local permit may also be necessary.

Additionally, EPA should conclude a study of effluent guidelines by the end of the year. If adopted, such guidelines could drive investments in additional types of maintenance equipment such as deicing pads, says Dan Viscardi, a vice president in the Atlanta office of Cambridge, Mass.-based Camp, Dresser & McKee.

Just as concerns about snow and ice control vary depending on an airport’s geographical location, so does the threat of birds. Although runways are for planes, birds like them, too. Unfortunately, they pose a danger as they often are sucked into aircraft engines. “Seagulls are a big pain in the neck,” APWA’s MacMullen says. He says several airports fire carbide cannons into the air to scare the birds away.

“It’s an issue that the FAA has all of a sudden decided to make a higher priority,” Evans says. In fact, the agency requires each airport to conduct an ecological study, called a “wildlife hazard assessment,” to determine how severe the problem is, what types of birds are involved and what contributing factors (e.g., ponds, nests, food sources and trees) exist. Following completion of the study, each airport is required to come up with an F AA-approved plan to solve the bird problem, Evans says.

Integration and innovationWhile outside maintenance may be more visible than terminal maintenance — and more critical, as far as passenger safety is concerned — maintenance inside the terminal also is important. Components such as escalators, fire alarms, voice mail, automated doors and automatic sprinkler systems exemplify how terminals are becoming increasingly reliant on technology.

Moreover, many airports are integrating their maintenance systems, which worsens the potential damage that the Y2K problem could cause. The FAA’s Year 2000 Program Office, established to ensure that the safety of the National Airspace System is not compromised by the computer problem, claims it will have all FAA systems Year 2000-compliant by June 30. Nevertheless, individual airports must check their own systems for vulnerability to the Y2K bug.

“All terminals, all over the country, are really constantly in need of improvement,” says Jack Driscoll, executive director of Los Angeles World Airports, a city agency that oversees Los Angeles International and several other airports. Often, that improvement involves upgrading technology.

The new terminal at T.F. Green Airport in Warwick, R.I., was built with technological progress in mind. Believing that new types of equipment and infrastructure will be needed in the future, designers there installed a generous network of cable trays above the ceiling panels for future additions or replacements of cables. The Cincinnati and Seattle airport terminals, in which cubicles offer passengers Internet access, a printer, a fax machine and a PC, may provide a glimpse into the future of terminal design.

Because it must be done constantly on a broad array of equipment and infrastructure, airport maintenance can be costly. In some cases, lack of money can be a problem. But, because the safety issues are so evident, airports generally are maintained better than streets and highways.

“I think from an infrastructure standpoint, you are not going to find airports deteriorating,” Driscoll says. He notes that the money from ticket taxes, terminal lease fees and landing rights paid by airlines to airports, usually is sufficient to fund maintenance. Further, the FAA’s periodic inspections, which are required for certification, serve as a strong incentive for airports to come up with the necessary funds.Still, costs are bound to rise. “Maintenance” as a concept will broaden, in large part because of the way technology is reshaping transportation, communications and other aspects of daily life.

“Ten years ago, maintenance was keeping the place clean. Today, it involves dealing with very sophisticated computer controls and mechanical equipment,” Evans says. Those airports that continue to explore the growing scope of maintenance, and devote adequate resources toward it, will be best equipped to keep up with tomorrow’s increasingly mobile population.

If there is one thing that can be said for certain about municipal airports, it is that maintaining them is a never-ending job. Ongoing maintenance — particularly involving runways, taxiways and lights — is needed to handle the nonstop traffic.

Aside from the routine duties — patching, painting, lubricating, replacing worn parts — maintenance involves such disparate responsibilities as keeping birds off the runway area; training and equipping emergency response crews for fires or accidents; formulating a coordinated snow storm response plan; monitoring runoff from deicing and cleaning solutions; and keeping runway lights functioning properly.

All of that must be accomplished while the planes — and people — come and go. “Airports are expensive places to maintain. There is such high-density usage,” says Ginger Evans, national director of aviation services for the Denver office of Carter & Burgess, Fort Worth, Texas.

According to projections from the Federal Aviation Administration (FAA), airport usage in the United States will double to more than 900 million people per year by 2010, making maintenance all the more critical. “If you look into the future, passenger traffic is only going in a straight line upward,” says Gerald Fitzgerald, president of Parsons Brinckerhoff Transportation in New York. He adds that, depending on a maintenance crew’s effectiveness, an airport can become a drain on resources or a vital cog in the wheel of economic activity.

Maintaining pavementIf aircraft do not have well-maintained surfaces for landing and takeoff, virtually every other aspect of maintenance becomes a moot point. Thus, tasks such as patching potholes, sealing cracks, repairing concrete joints and resurfacing with asphalt are of paramount importance — particularly from a safety standpoint. “You’ve got this tiny aircraft tire with this huge weight on it. Your psi (pounds per square inch) goes through the roof,” Evans says.

“Most airports, even big ones, use fairly low-tech paving,” says Richard Marchi of Airports Council International, a Washington, D.C.-based trade and lobbying organization. There are exceptions, such as a test strip at Chicago’s O’Hare Airport that features electrically conductive asphalt containing synthetic graphite made by Chicago-based Superior Graphite. Not only does the asphalt warm up to melt snow and ice (at a high cost for the electricity), but, by minimizing drastic temperature changes, it could reduce cracks and potholes. “Basically, the technique works, but the cost/benefit equation has not been resolved yet,” Marchi says.

Airports that handle major commercial airliners generally have runways made with reinforced concrete — in some cases 17 inches thick, says John MacMullen, professional development manager for the American Public Works Association (APWA), Kansas City, Mo. However, small airports outnumber the large ones, and asphalt is used more commonly at the small ones because it costs less than concrete and can support the relatively lightweight aircraft. More than 90 percent of the runways in FAA’s database are asphalt.

Although aviation officials recognize the importance of consistent pavement maintenance, some of them may not do much about it. A recent Government Accounting Office (GAO) study questioned the nation’s runway maintenance track record. The study found that about three-quarters of the runways in GAO’s database were in good to excellent shape, and 26 percent were rated from fair to poor. Unfortunately, runways in that 26 percent have reached or surpassed the point at which they can be rehabilitated economically, GAO says. Small airports, often those faced with severe budgetary constraints, may be most likely to struggle in keeping up their maintenance, Marchi says.

Computerized pavement management systems, which help ensure adherence to regular maintenance schedules, have become much more common at airport maintenance departments during the past three or four years, Evans says. Micro PAVER, public domain software offered by APWA, offers tools such as a database, a PCI (Pavement Condition Index) calculator, graphics, photo storage and a budget estimator. It is used at Tampa (Fla.) International Airport and at airports in Reno, Nev.; Memphis, Tenn.; and other cities.

Time crunchWith airports getting busier all the time, finding enough “down time” for crews to work can pose a challenge. “You’re always going to be restricted to a fairly narrow window of time,” Evans says. She notes that major hubs already have “maxed out” their peak hours for arrivals and departures, and, when they add flights, they must schedule them for the slower hours. That cuts into precious maintenance time.

Consequently, as is the case with highway maintenance, runway maintenance and repairs often are done in the middle of the night when air traffic is minimal. “Many airports start [runway maintenance] at 11:30 p.m. or midnight and stop at 4:30 a.m.,” Marchi says.Nighttime construction can be costly, because crews must move lights, construction equipment and portable generators on and off the runway in a few hours, sometimes for several consecutive nights. Additionally, factors such as weather and availability of nighttime personnel affect runway maintenance strategies.

At Tampa International Airport, individual runways are closed each month for visual inspections lasting an hour or two, says Larry Smith, director of facilities for the Hillsborough County (Fla.) Aviation Authority. Staying on top of maintenance needs enables the airport to avoid costly concrete rehabilitation, he notes.

Like many other airports, Tampa International uses the PCI rating system to evaluate sections of pavement. The PCI, which is used by the GAO but not the FAA, consists of a rigorous visual inspection of pavement surfaces for signs of deterioration. It is based on a scale of 0 to 100, and the numeric rankings are clustered into seven categories: excellent, very good, good, fair, poor, very poor and failed.

Employing a far different strategy than that used by Tampa International, Dallas-Fort Worth Airport took the unusual step of shutting down a runway for a 12-day rehabilitation. But, before the project could get under way, it took nine months for 15 parties (airlines, maintenance crew, fire department and others) to reach a consensus on when to close the runway and what the project’s time frame would be.

Other maintenanceAside from pavement, airports have many other components — both inside and outside the terminal buildings — that require maintenance. Many are electrical, such as gate display monitors, baggage location displays and lighting systems.

“Airfield lighting is an area that requires constant vigilance and maintenance,” Evans says. Fortunately, that job is made easier by monitoring software, which keeps track of replacement schedules and alerts maintenance personnel to interim problems.

Some types of maintenance, such as snow and ice control on the runways, taxiways and gate areas, are seasonal and regional. Last month, officials at Detroit Metro Airport learned the hard way what can happen when a snowstorm hits a major airport that is unprepared. After a foot of snow blanketed southeastern Michigan on Jan. 2, the nation’s 10th busiest airport remained in a state of chaos for several days.

Some 64 pieces of equipment were used to remove the snow from more than 2 million square feet of pavement, according to The Detroit News. And, despite keeping two runways open during the storm, crews failed to clear snow and ice from many gates. Some of the passengers, who were stranded in aircraft parked on the tarmac for up to 10 hours in subzero conditions, have filed suit against the airport, Wayne County and Northwest Airlines.

In addition to plowing and hauling away snow, maintenance crews at northern airports must incorporate anti-icing (before-the-fact prevention) and deicing (after the fact) into their ice control programs. Anti-icing materials — solutions such as sodium acetate used for runways, sidewalks and roadways — must be certified by the FAA for flashpoint, storage stability and corrosive effects to aircraft and pavement.

Anti-icing and wing deicing materials (such as propylene and ethylene glycol) create runoff, another maintenance concern. In most cases, National Pollutant Discharge Elimination System stormwater permits are needed for such runoff, particularly if it discharges directly into a waterway. When the discharge goes to a municipal wastewater treatment plant, a local permit may also be necessary.

Additionally, EPA should conclude a study of effluent guidelines by the end of the year. If adopted, such guidelines could drive investments in additional types of maintenance equipment such as deicing pads, says Dan Viscardi, a vice president in the Atlanta office of Cambridge, Mass.-based Camp, Dresser & McKee.

Just as concerns about snow and ice control vary depending on an airport’s geographical location, so does the threat of birds. Although runways are for planes, birds like them, too. Unfortunately, they pose a danger as they often are sucked into aircraft engines. “Seagulls are a big pain in the neck,” APWA’s MacMullen says. He says several airports fire carbide cannons into the air to scare the birds away.

“It’s an issue that the FAA has all of a sudden decided to make a higher priority,” Evans says. In fact, the agency requires each airport to conduct an ecological study, called a “wildlife hazard assessment,” to determine how severe the problem is, what types of birds are involved and what contributing factors (e.g., ponds, nests, food sources and trees) exist. Following completion of the study, each airport is required to come up with an FAA-approved plan to solve the bird problem, Evans says.

Integration and innovationWhile outside maintenance may be more visible than terminal maintenance — and more critical, as far as passenger safety is concerned — maintenance inside the terminal also is important. Components such as escalators, fire alarms, voice mail, automated doors and automatic sprinkler systems exemplify how terminals are becoming increasingly reliant on technology.

Moreover, many airports are integrating their maintenance systems, which worsens the potential damage that the Y2K problem could cause. The FAA’s Year 2000 Program Office, established to ensure that the safety of the National Airspace System is not compromised by the computer problem, claims it will have all FAA systems Year 2000-compliant by June 30. Nevertheless, individual airports must check their own systems for vulnerability to the Y2K bug.

“All terminals, all over the country, are really constantly in need of improvement,” says Jack Driscoll, executive director of Los Angeles World Airports, a city agency that oversees Los Angeles International and several otherairports. Often, that improvement involves upgradingtechnology.

The new terminal at T.F. Green Airport in Warwick, R.I., was built with technological progress in mind. Believing that new types of equipment and infrastructure will be needed in the future, designers there installed a generous network of cable trays above the ceiling panels for future additions or replacements of cables. The Cincinnati and Seattle airport terminals, in which cubicles offer passengers Internet access, a printer, a fax machine and a PC, may provide a glimpse into the future of terminal design.

Because it must be done constantly on a broad array of equipment and infrastructure, airport maintenance can be costly. In some cases, lack of money can be a problem. But, because the safety issues are so evident, airports generally are maintained better than streets and highways.

“I think from an infrastructure standpoint, you are not going to find airports deteriorating,” Driscoll says. He notes that the money from ticket taxes, terminal lease fees and landing rights paid by airlines to airports, usually is sufficient to fund maintenance. Further, the FAA’s periodic inspections, which are required for certification, serve as a strong incentive for airports to come up with the necessary funds.Still, costs are bound to rise. “Maintenance” as a concept will broaden, in large part because of the way technology is reshaping transportation, communications and other aspects of daily life.

“Ten years ago, maintenance was keeping the place clean. Today, it involves dealing with very sophisticated computer controls and mechanical equipment,” Evans says. Those airports that continue to explore the growing scope of maintenance, and devote adequate resources toward it, will be best equipped to keep up with tomorrow’s increasingly mobile population.

Ontario (Calif.) International Airport has opened a $270 million twin terminal complex in an effort to better serve its steadily increasing number of air passengers. The airport began the project in Fall 1995 and opened the complex in September 1998 — more than four months ahead of schedule and $26 million under budget. “This is a model for how the region’s airports can grow in harmony with the needs of the region and environment,” says Los Angeles Mayor Richard Riordan.

According to the Torrance-based Southern California Association of Governments, a 100 percent increase in air passenger demand is projected for the five-county Southern California region, from today’s 80 million passengers per year to 160 million in 2020. Ontario International’s two new terminals represent an eightfold increase in the airport’s size.

The Los Angeles-based architectural firm of Daniel, Mann, Johnson & Mendenhall designed the terminals to reflect the history of flight and to provide a panoramic view of the mountains north of Ontario. The glass-enclosed structures total about 530,000 square feet, have 26 gates, and can accommodate up to 10 million passengers a year. That is a 58.7 percent increase from the current 6.3 million passengers using the airport every year.In addition to their aesthetic appeal, the terminals are energy efficient. Both buildings face north, enabling the windows and ceiling to distribute maximum light without radiating heat throughout the building.

“The new airport represents a major advance in our efforts to bring regional solutions to meet Southern California’s ever-growing future air transportation needs,” says John Driscoll, executive director of Los Angeles World Airports (LAWA), the Los Angeles city department that operates Ontario International, Los Angeles International, Van Nuys and Palmdale Regional airports. Ontario International currently has 10 passenger and commuter carriers and eight cargo carriers that serve virtually every major U.S. city. In addition to handling growth in scheduled airline service, the new complex will be able to accommodate increased air charter service.

The new terminals will feature a $1.6 million public art program that includes a permanent installation of works from world-class artists. Integrated throughout the ticketing, baggage claim and concourse areas, the pieces are composed of a number of different materials, including glass, mosaic, tile, bronze and etched stone. All the artists represented in the permanent collection were selected through outreach with public museums and nonprofit art centers throughout California.

On-site restaurants and retail shops will serve travelers and the surrounding community. Concessionaires have agreed to charge their normal street prices.

Aside from the building improvements, infrastructure components were upgraded to handle future growth. For example, an advanced telecommunications and fiber optic network was incorporated into the terminals. Additionally, a new roadway system linked the terminals and three new parking areas with 4,900 parking spaces — bringing the airport’s total parking capacity to more than 13,400 spaces. A new ground transportation center, which opened in January, accommodates six major rental car companies.

Facilities also are planned to handle the expected growth in air cargo moving through Ontario. Since 1992, air cargo flowing through the airport has increased 50 percent to more than 460,000 tons. The growth is expected to continue as the population and economic importance of the Inland Empire steadily rises.

Funding for the terminal expansion came from a variety of sources, including $148.3 million from the passenger facilities charge collected from users of LAWA airports; $94.2 million from airport revenue bonds issued by LAWA; and $27.3 million from the Federal Aviation Administration.

An additional $160 million in local infrastructure improvements — including construction of new airport access roads and expansion of Interstate 10 — was jointlyfunded by LAWA, the city of Ontario and the California Department of Transportation. The old terminals will be converted to commercial uses.

Ontario International already supports about 60,000 direct and indirect jobs in the area, with a total economic impact approaching $6 billion. The new terminal complex is expected to enhance that impact.

Hartsfield Atlanta International Airport is the world’s busiest airport, handling 67 million passengers per year. Despite its location in a relatively mild climate, the airport does face the threat that freezing rain can pose t o aircraft during the winter months.

Last December, construction was completed on the airport’s first deicing pads, holding areas located near the runway where aircraft are treated with ethylene glycol and othersolutions prior to takeoff in cold weather. Before the pads were installed, aircraft treatment occurred at the gates, which delayed airport traffic and caused concerns about runoff of deicing solutions.

Eight workers took three weeks to complete a four-pad deicing station, with most of the time spent digging the holes. The airport chose ProLink high-density polyethylene (HDPE) pipe from Columbus, Ohio-based Advanced Drainage Systems for the retention/detention systems under the deicing station. Sharpsburg, Ga.-based SDL Environmental helped build the deicing pads, and Cambridge, Mass.-based Camp, Dresser & McKee provided engineering services.

The new facility features four glycol retention/detention systems underneath the deicing areas. The systems capture deicing fluid and/or stormwater runoff, serve as a holding pen and slowing dispersement to the allowable outflow rate. Four 100-by-100-foot holes each contain three rows of HDPE pipe buried 22 to 25 feet deep.

Each containment system has been dubbed by contractors as a “tuning fork” because of its three-pronged appearance. Its layout consists of three rows of 48-inch diameter pipes that are sealed on one end. The open ends feed into 15-inch tees of corrugated pipe. The smaller pipe provides the path to the city’s sanitary sewer system for deicing fluid runoff, and to the airport’s existing drainage system for stormwater runoff.

Hartsfield’s four containment systems were built underneath the international concourse’s ramp area and are subject to the weight of a Boeing 747 — nearly 400,000 pounds when empty. Airport officials determined that HDPE pipe is strong enough to withstand that weight and the corrosive nature of the deicing solutions.

After installation, the tuning forks were covered with gravel and about 3,500 yards of dirt. In addition to the deicing pad containment system, sanitary sewer and storm piping were installed.

The deicing facility is part of a 20-year master plan for airport expansion and improvements designed to handle a projected 90 million passengers per year in 2005. A $300 million international terminal was completed in 1994, and a three-story atrium in 1996. Future projects include wetlands permitting and evaluations of construction impacts on historic and archaeological features.