The IAD E-Line Sanitary Sewer System Improvements Project at Washington Dulles International Airport upgraded a critical portion of the airport's sanitary sewer system for the Metropolitan Washington Airports Authority (MWAA). The project delivered 4,900 linear feet of new 36-inch PVC sanitary sewer and 3,800 linear feet of rehabilitation, improving the reliability and capacity of essential utility infrastructure at one of the region's busiest airports.
As part of its scope, Dulles Engineering provided comprehensive engineering and geotechnical services on the project. This included geotechnical investigation through SPT borings, seismic surveys, and laboratory testing to characterize subsurface conditions, along with the design of excavation support and trench protection systems to depths of 23.25 feet. DE also developed utility protection standard operating procedures to safeguard existing infrastructure during construction.
All designs were completed in accordance with AASHTO LRFD, OSHA 1926, and NDS standards, ensuring safe construction practices, structural stability, and reliable protection of the critical utilities surrounding the work. Through its engineering and geotechnical expertise, Dulles Engineering supported the safe, code-compliant delivery of vital utility improvements at Washington Dulles International Airport.
Metropolitan Washington Airports Authority (MWAA)
Stacy Witbeck / Anchor Construction JV
Washington Dulles International Airport (IAD)
February 2025 - May 2026
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