The design-build team of Ulliman Schutte and Brown and Caldwell has been awarded a contract by DC Water to provide design, engineering and construction services for the rehabilitation of a deteriorating segment of the Potomac Interceptor.
The Potomac Interceptor (PI) is a critical component of DC Water’s sewer network, conveying an average daily wastewater flow of 60 million gallons per day (MGD). Its 50-mile service area extends from the Washington Dulles International Airport through multiple northern Virginia and Maryland counties to the Blue Plains Advanced Wastewater Treatment Plant, where flows are treated before safe discharge into the Potomac River.
Following its inspection of the entire PI, DC Water is performing numerous sewer rehabilitation projects as part of a Capital Improvement Program to improve the District’s sewer infrastructure. For this effort, a buried section of the PI along the historic Potomac Heritage Trail, which accepts flows from Virginia’s Fairfax and Loudoun Counties, and Maryland’s Montgomery County, will be rehabilitated and renewed to prolong the life of the 60-year-old system and provide continued long-lasting resiliency.
The project will use the progressive design-build collaborative delivery approach, a first for a DC Water pipeline project. This method allows the contractor to be fully engaged during the design phase of the project.
The reputable and highly experienced Ulliman Schutte/Brown and Caldwell design-build team will design the repair and renewal of 600 lf of 54- to 78-in. diameter pipe as deep as 65 ft below grade. Using corrosion-resistant lining while incorporating energy-dissipating measures will help quell turbulence and control corrosive sewer gas. A key aspect of the project involves the design of a temporary pump and flow control system or permanent diversion structures to bypass segments of the PI during construction and maintain uninterrupted service. Additionally, the team will coordinate with DC Water to develop a stakeholder outreach program to proactively engage the community to help shape the project’s path forward.
The Ulliman Schutte/Brown and Caldwell team have a proven history of delivering award-winning infrastructure projects. Recent partnerships include repairing deteriorated sewer tunnels below downtown Louisville, Kentucky, and the $78 million Southwestern Parkway Combined Sewer Overflow Basin project, hailed by the Design-Build Institute of America as 2019’s best engineering design feat.
“In the true spirit of collaboration, the team is honored to have the opportunity to contribute to the success of DC Water’s long-term asset resiliency planning,” said Brown and Caldwell Senior Vice President Carey Allen.
Design phase activities are expected to be completed in 2021. Upon design finalization, construction activities will be methodically scheduled to reduce impacts on neighboring communities and a popular regional park.