What’s in Your Pipe? Quality Management for 100-Year Life Raw Water Pipeline

The Tarrant Regional Water District (TRWD) with the City of Dallas Water Utilities (DWU), are currently engaged in the planning, design, and implementation of a 350 MGD raw water transmission system, which will run across north central Texas from Lake Palestine to Lake Benbrook, with connections to Cedar Creek Reservoir, Richland Chambers Reservoir, and a Dallas delivery point. Collectively, the system consists of approximately 145 mi of 84- to 108-in. pipeline, a 5-mi 120-in. diameter tunnel, six 100-350 MGD pump stations, one 450 MG balancing reservoir, and ancillary facilities. The program developed by TRWD to accomplish these improvements is called the integrated pipeline project (IPL). The IPL program consists of dozens of projects from design phase to equipment pre-purchases and construction. To manage these myriad projects, a standard Quality Management approach was adopted to ensure individual projects meet overall program goals. Starting in 2013 and continuing to present, Phases 1 and 2 of IPL Construction consist of 17 construction contracts (80 mi of 84”–108” pipeline, three pressure reducing stations, two pump stations, a balancing reservoir, etc.) and nine equipment pre-purchase packages. This includes nine different contractors, 13 pipe and equipment suppliers and numerous subcontractors, design engineers, and consultants. To provide consistent, high quality finished product to the Owner, significant quality management measures were essential for this project. This paper will discuss quality management processes, decisions, and lessons learned focused on pipe design, manufacturing, and installation for this interesting project.