With more people using the Charlotte Douglas International Airport (CLT Airport) every year, plans are underway for a main terminal lobby expansion, 24-gate concourse addition, and other future expansions. To support this program, STV designed approximately 2,300 linear feet of new sanitary gravity sewers to convey sewage to the existing Charlotte Water (CLTWater) Coffey Creek sewer interceptor. The firm’s design integrated seven trenchless crossings through existing roadways, parking lots, and the new passenger access deck in the airport’s main terminal, including a 300 feet 48 inch diameter steel casing located 35 feet deep to link to the existing interceptor, and a bored casing threaded between piles of an existing retaining wall. Each of these complex installations were completed without disrupting airfield or aircraft activity.

STV also worked alongside CLT Airport and CLTWater personnel on providing sewer modeling, design, permitting, and construction administration while navigating the need for continuous traffic control and terminal maintenance access along Rental Card Road and access to FAA control tower, and the challenge of limited workspace in high traffic zones. As this project portion involved working with partially weathered rock, geophysical probing and analyses were completed to determine its condition.