Progressive Design Build: How DC Water Used Collaborative Delivery to Make Large Diameter Sewer Rehabilitation Possible

The Potomac Interceptor (PI) is a 48-mi-long multijurisdictional large diameter sewer operated by DC Water. It conveys flow from surrounding counties to the Blue Plains Advanced Wastewater Treatment Plant. The PI is one of the DC Water’s most critical sewers with a peak flow of 90 million gallons per day (mgd) with no redundancy. Rehabilitation of this section is particularly challenging, because it is directly adjacent to the Potomac River, within a Northern Virginia (NOVA) Park, on federally funded land, and only accessible through private roads. This intersection of state, federal, and private land presented challenges that spanned the technical, political, and public spheres. The presentation will focus on why Progressive Design Build (PDB) was chosen for this high-risk and complex linear pipe rehabilitation. It will highlight how an experienced Design–Build Institute of America (DBIA)-certified Owner’s Advisor guided DC Water in Design–Build Best Practices, leading to the successful planning, procurement, and contracting of the project. The presentation also includes drivers for choosing of PDB, critical stakeholder engagement, building a high-performing team, risk allocation and mitigation during design development (integral to price negotiation), “in-the-dry” concept to maintain flow throughout construction without bypass pumping, flow conversion and final commissioning, utility owner’s experience during the PDB, lessons learned, as well as cost and time efficiencies using PDB.