In the spring of 2016, the Dallas/Fort Worth (DFW) International Airport opened a bid for an aircraft hardstand ramp expansion. Part of these improvements included several new aircraft fueling locations as well as additional hardstand space for deicing planes prior to take off, driving the need for a new storm drain and collection system.
Consequently, the DFW International Airport needed a cost-effective solution to properly store storm water contaminated with deicing fluid prior to being treated. The system needed to have a small footprint that would allow them to maximize the available land space. It must also meet the heavy live-loading design specification to accommodate an Airbus A380 - the world's largest passenger airliner. The airports at which the A380 operates must have upgraded facilities to accommodate it.
DFW International Airport worked closely with their consulting engineer, ATKINS, to choose an optimum collection, storage and treatment system. Ultimately, they selected a solution by Contech Engineered Solutions LLC which utilized DuroMaxx® steel reinforced polyethylene (SRPE) pipe and met AASHTO MP20 standard specification. This system would serve as an underground storage chamber from which the runoff would be pumped to a treatment system constructed above. The complete system consisted of 268 LF of 96-inch diameter pipe resulting in 13,053 CF storage volume. DuroMaxx is a reinforced polyethylene pipe with a smooth waterway wall and exterior profile that is reinforced with high strength galvanized steel ribs. While DuroMaxx provides a completely structural solution, it is also lightweight and installation was quick, which meant less expense and fewer dewatering issues. Given the sensitivity of the chemicals being stored here, it was also crucial that the joints be leak-free. The DuroMaxx system was designed with welded coupler (WC) joints capable of a 30 psi, watertight connection conforming with the ASTM D3212 joint requirements. Lastly, both bulkheads and risers for the DuroMaxx SRPE glycol storage system were custom-designed to handle the heavy live-loading from an Airbus A380.
There was some concern on the ease of maintaining a glycol storage system after installation. Fortunately, DuroMaxx SRPE glycol storage systems include manhole risers allowing easy access and maintenance. Because the pipe is round (as opposed to a concrete vault or box) and the polyethylene material is smooth and has a very low coefficient of friction, it is much easier to flush silt and debris from one end of the system to the other where, once accumulated, it can be removed with a vacuum truck from that one end of the system.
Chad Richards, P.E., Senior Project Manager at ATKINS, commented, "We were challenged to provide storage from pretreatment runoff from airfield operations and required a product that was cost-effective but met the stringent loading and life cycle design requirements required by the airport. Under a strict timeline, Contech provided a solution that satisfied our Engineering team, addressed client concerns, and provided responsive, technically capable staff to assist with a fully integrated final product."
DFW International Airport was extremely satisfied with the selected DuroMaxx SRPE system which exceeded the design requirements, was easy to install and easy to maintain.