Our team developed design and bid documents for conversion of fire suppression systems at existing United Airlines facilities at the airline’s Denver International Airport (DEN) Maintenance Operations Center (MOC) from PFAS-containing aqueous film-forming foam (AFFF) concentrate to fluorine-free foam (F3).

Because the MOC is an active facility with ongoing maintenance work, we were challenged to minimize downtime to operations. The project — covering three MOC hangars — was initially driven by pending state regulations requiring the removal of per- and polyfluoroalkyl substances (PFAS)-containing AFFF from the fire suppression systems.

We used the combination of a parallel pumped concentrate system and a multiphase approach to address these challenges. Because of the longer piping runs of concentrate and the higher viscosity of the F3 product, innovative methods were required to balance the system. During commissioning, we worked closely with the contractor to solve challenges and obtain fire marshal approval.

Because the existing system did not meet current code, we worked with the fire marshal to develop engineering equivalencies that would allow for a shorter construction schedule and reduce intrusion into active hangar areas. Beyond the fire suppression system, we also added foam monitors, releasing panels, and upgrades to the fire alarm system and firewater supply.