Southwest Airlines Maintenance Hangar at William P. Hobby International Airport (HOU)

Southwest Airlines officially added a new 240,000-square-foot maintenance complex to its facilities at William P. Hobby International Airport (HOU) on January 8, 2020 in Houston, Texas. The maintenance facility, Southwest’s largest maintenance facility to-date, will service the airline’s growing operation at Hobby Airport, which includes almost 200 departures per day during peak seasons to nearly 70 destinations across the United States, Latin America and the Caribbean.

As a part of this expansion, underground watertight tanks were needed to capture contaminated runoff from the Southwest Airlines maintenance facility. In the event of a fire, the chemical used in the suppression system to retard and put out the fire is not permitted to drain into standard storm drain systems. Therefore, the rainwater runoff after such an event (and drainage during clean up) must be contained in a watertight system, pumped out, and sent to a proper treatment facility.

In addition to the need for containment of aqueous film forming foam (AFFF) runoff, the tank system would also need to be aircraft load rated. DuroMaxx® steel reinforced PE (SRPE), manufactured by Contech Engineered Solutions LLC, provided a solution. The final storage system design included four (4), large 120-inch diameter tanks, each 98 LF and welded joints that provided the strength to handle the necessary loading requirements as well as the desired storage, providing 54,572 gallons of storage.

Alternative solutions were considered, but a cast-in-place concrete vault system would have required more time to construct, requiring the assembly of forms, steel rebar, pouring, curing, striping, and water proofing. The DuroMaxx SRPE system was more cost-effective and also saved valuable construction time. Ferguson Waterworks worked directly with the contractor, McCarthy Building Company, to supply the final solution.