E-Line Sanitary Sewer

The E-Line Sanitary Sewer System Improvement Project is an infrastructure project for the Metropolitan Washington Airports Authority (MWAA) located at Washington Dulles International Airport (IAD) in Dulles, Virginia. The project involves rehabilitating and expanding the existing E-Line sanitary sewer network located primarily within the airport's active Aircraft Operations Area (AOA).  

As a critical utility link, the E-Line system meters and conveys wastewater flow to the Potomac Interceptor. In addition to extensive pipeline installation and rehabilitation, the project encompasses system upgrades to the Cub Run Pump Station as well as comprehensive airfield and roadway pavement restoration.  

Need 

The existing E-Line sanitary sewer infrastructure required significant rehabilitation to address aging and deteriorating pipelines and manholes while improving system capacity for future growth. With increasing wastewater demands from current airport operations and planned expansions, including the Tier-2 Concourse, the project was needed to ensure the sanitary sewer system could reliably support both existing and future airport development. 

The improvements modernized critical infrastructure, reducing the risk of structural failures and sanitary sewer overflows while providing a more resilient and dependable system. By upgrading the network ahead of long-term growth, the project helps protect the environment, maintain regulatory compliance, and ensure continuous wastewater service throughout the airport. 

Work

Pipeline Construction, Removal & Abandonment

• Demolition and removal of approximately 3,800 linear feet (LF) of existing sanitary sewer pipe and associated manholes. 
• Construction of approximately 3,800 LF of new 36-inch diameter PVC sanitary sewer pipe within the same trench alignment. 
• Construction of approximately 5,000 LF of new 36-inch diameter PVC sanitary sewer pipe along a new alignment. 
• Construction of approximately 495 LF of 3-inch diameter PVC sanitary sewer force main, along with relocation and abandonment of sections of existing force main. 
• Grouting and abandonment of approximately 3,600 LF of existing sewer pipe and manholes, with manholes removed to 3 feet below grade followed by site restoration. 

Trenchless Rehabilitation (CIPP)

• Installation of approximately 7,550 LF of Cured-In-Place Pipe (CIPP) lining across multiple pipe diameters.  

Cub Run Pump Station & Facility Upgrades

• Removal of an existing 35-foot by 35-foot concrete dump pad and perimeter walls, and construction of a new 30-foot by 30-foot sanitary sewer concrete dump pad and walls. 
• Replacement and installation of ultrasonic flow meters, venturi flumes, new wiring, wireless transmitters/receivers, and solar power modules for remote meter operations. 

Airfield, Pavement & Civil Restoration

• Full-depth saw cutting, selective removal, and reconstruction of concrete airfield taxiway pavements, asphalt shoulders, and markings over utility trenches. 
• Reconstruction of asphalt roadways and gravel service roads over utility trenches. 
• Deep excavations and trench rock blasting within the Aircraft Operations Area. 
• Airfield security fencing removal, replacement, and full site restoration. 
• Implementation of temporary sewage bypass pumping systems and Stormwater Pollution Prevention Plan (SWPPP) Best Management Practices (BMPs). 

Innovations  

• CIPP Trenchless Technology: Employed CIPP lining as am innovative trenchless rehabilitation technique for approximately 7,550 linear feet of existing sewer lines, minimizing open-trench excavations and lowered disruption across the active airfield.  
• Phased Construction Sequencing: Executed construction across eight distinct, sequential phases to maintain continuous taxiway and taxilane cargo apron operations throughout the project, coordinating closures within strict time windows to protect airport operations.  

Collaboration 

Extensive collaboration with MWAA operations, airport traffic control, COTR, the Airport Communications System, Virginia Department of Environmental Quality, and coordination with regional stakeholders such as DC Water and the National Park Service regarding flows into the Potomac Interceptor network.