Upper Trinity Regional Water District Stone Hill Parallel 72-inch Pipeline

Plummer designed a 3.8-mile, 72-inch diameter parallel pipeline, which included 10 trenchless crossings below Dallas Area Rapid Transit Rail tracks, Kansas City Southern Railroad tracks, Denton County Transportation Authority Rail tracks, Texas Department of Transportation highways, and City of Lewisville major roads. The tunnels were unique, because one passed beneath the rail tracks at a 39-degree angle and one tunneled underneath I-35, including two 30-foot vertical shafts to avoid risk to the adjacent parallel 48-inch diameter line. The alignment was congested and bound by housing developments, apartment complexes, railroad property, and the existing 48-inch pipeline. Plummer was successful in utilizing the existing easements and minimizing easement acquisition.

The project was completed using a Construction Manager At-Risk (CMAR) delivery method and was broken into 10 different bid packages to allow three pipe segments and three different tunneling packages to be constructed simultaneously to meet the demanding 14-month schedule.