10 airport water conservation strategies
Airports rely on available potable and reclaimed water during construction and in daily operations, on the airfield and in the terminals. Ways to conserve that water are as varied as the properties and facilities involved.
Some of these strategies may seem familiar. Other strategies are innovative and were developed with critical thinking on how to conserve natural resources.
U.S. airports are conserving water in a variety of ways:
Reclaimed water use
Airports from coast-to-coast are reclaiming their water resources.
In Central Florida, Orlando International Airport (MCO) recently opened an Automated People Mover/Intermodal Transit Facility (APM/ITF). Thanks to native plants and reclaimed water usage there is no potable water used for irrigation.
To the west at Dallas/Fort Worth (DFW), the airport partnered with nearby cities to create a reclaimed water delivery system.
The rental car wash bay at Salt Lake City International Airport (SLC) recycles 85% of its water.
In drought-challenged California, Los Angeles International Airport (LAX) now uses recycled water for street sweeping, construction dust control, and car washing. Since 2015, reclaimed water use for landscaping has increased by more than 20%. Purple pipe, indicating recycled water, is seen at the Bradley West Terminal as well as the Central Utility Plant.
Advanced water purification
Beginning in 2019, an Advanced Water Purification Facility (AWPF) at LAX will treat 1.5 million gallons of sewage each day. The AWPF will produce one million gallons of high quality recycled water for use at the airport’s Central Utility Plant, Midfield Satellite Concourse, and the Consolidated Rent-A-Car facility.
The 43-acre Hoover rock quarry, east of Nashville International Airport (BNA) runway 2R/20L, is the largest geothermal lake plate cooling system in North America. With an average depth of 150 feet, the quarry contains approximately 1.5 billion gallons of water.
At a 50-foot depth, water remains 50 degrees Fahrenheit year-round. Circulated through the quarry’s submerged geothermal heat exchangers, that water cools the air for the entire terminal.
Use of air conditioning condensate
The Air Conditioning Condensate Recycling Program collects condensate water at 14 San Diego International Airport (SAN) passenger boarding bridges. Hoses route the water to a 55-gallon barrel. That is later placed in a 500-gallon storage tank, to be taken by trailer to a to a power washer.
Power washers are mainly used on curb fronts and arrival and departure roadways. At other times, the condensate may be used to wash down the airfield or service vehicles.
Low-flow fixtures have been installed in restrooms at MCO, LAX, and Hartsfield-Jackson Atlanta International Airport (ATL). Ultra low-flow systems will conserve up to 1.25 gallons per flush.
After an update to the Plane Train system at ATL, groundwater collected from the system tunnels for use in terminal boilers.
Among the infrastructure upgrades at MCO, two cooling towers were replaced.
Responding to severe drought conditions, two airports in California irrigate to conserve water. At SAN, landscaping near Terminal 1 which once received fresh water is now irrigated. LAX allows irrigation only two days per week.
The quarry lake which BNA uses for geothermal cooling also supplies water for its landscape irrigation.
A high-efficiency system at SLC connects all irrigated landscapes to a central location. There, a weather station controls irrigation to specific landscapes, based on current wind, rain, humidity, and temperature measurements.
In 2001, SLC began converting to low-water landscaping, planting drought-tolerant species and designing efficient irrigation systems.
SAN implemented water-efficient landscaping at its Terminal 2 expansion.
A hardscape palette requiring low irrigation is also seen at LAX, where traditional landscapes have been converted to xeriscapes and, at some locations, artificial turf. Turfgrass in the Central Terminal Area has been replaced with bark and stone landscaping, requiring little or no irrigation.
At MCO, native and drought-tolerant landscaping surrounds the APM/ITF expansion, where reclaimed water is used.
Cecil Airport (VQQ) has dedicated 283 acres of Jacksonville, Florida land as a wetland preserve and has created wetland along 28 acres of existing streams and drainage. Beyond the beauty and open space provided, wetlands act as natural filters to remove fertilizers and other chemicals from freshwater supplies.
Options for stormwater management can be as natural as subsoil filtration and retention ponds, or leverage the technology of monitoring equipment and controls.
Over 503 acres of ponds retain stormwater at VQQ.
The Green Stormwater Infrastructure Plan for ATL project development places emphasis on infiltration, allowing runoff to percolate into the subsoil. This filtering through the subsoil can limit water table reduction.
A two-phase project at BNA targets $7 million in improvements to stormwater collection and treatment systems. State-of-the-art controls will monitor treatment system effectiveness and efficiency.
Individually and combined, the ten water conservation strategies are bringing significant benefits to airport operations.
Reduced water use per passenger
Looking year-to-year, airports that have implemented water conservation strategies have achieved a significant reduction in water use per passenger. Between 2011 and 2016, DFW trimmed water use per passenger by 24.3%. LAX achieved a 6.3% reduction during a single year of record-breaking passenger travel, 2015 to 2016. At MCO, per passenger water use was reduced 11.5% between 2010-2016.
Potable water conservation
Several airports have aimed for or already achieved significant percentage decreases in potable water consumption. In 2016, DFW saw 16% less potable water use than in 2011. ATL seeks a 20% reduction in potable water use from a 2008 baseline to 2020. The 2015 record decrease in LAX’s potable water use per passenger led to a two-year cumulative decrease of 26%. Much of that is attributed to new restroom fixtures which reduced potable water use by 22%.
Success can also be measured by the gallon. LAX conserves an estimated 396,625 gallons of water every day. That volume might equate to 1.5 Boeing 777 airplanes. BNA’s geothermal cooling project is designed to save 30 million gallons of potable water per year. The DFW water delivery system design would reduce consumption by over 100 million gallons per year.
Irrigation needs met
Average annual irrigation water use at SLC dropped 74% within 10 years, beginning in 2002.
Condensate water for pressure-washing
SAN recorded 103,000 gallons of condensate water reuse in 2016. That was a 46% increase over the previous year.
Reclaimed water for irrigation
In 2016, the volume of reclaimed water used at DFW exceeded 106 million gallons. Half of the landscaped areas at LAX are irrigated with reclaimed water. That reclaimed water use has increased more than 20% since 2015.
Water conservation strategies can result in six-figure utility expense savings.
Estimated utility savings from the BNA geothermal cooling project exceed $430,000 per year. This involves reducing electricity usage by 6,000 kilowatts of peak demand, an annual savings of 1.3 million kilowatt-hours.
Recycled water use at LAX has saved the airport $200,000.