GLWA CS-152 Route Study

Project Overview

The project team was retained to conduct a comprehensive pipeline  route analysis for a new finished water pipeline between Waterworks Park and the Northeast Station and ultimately prepare a preliminary design for the selected route. The comprehensive route analysis included consideration of a variety of route alternatives evaluated on both a cost and non-cost basis. The preliminary design was conducted to approximately the 30 percent level of completion and included the development of drawings, design criteria, cost estimates, schedules, and other information.

Project Scope

NTH, as the environmental specialist on the project team, prepared a preliminary environmental corridor study for each potential route under consideration. Following supplemental field investigation work, NTH was tasked with development of contamination mitigation measures.

NTH, as the geotechnical specialist on the project team, compiled geotechnical data from NTH archives and available public documents to develop geologic cross sections for potential routes under consideration. Technical memorandum were prepared to discuss anticipated geotechnical and groundwater conditions related to constructing and operating a pipeline along each alternative route.

GLWA ultimately elected to construct the project using a design build contract delivery system using the 30 percent deliverables to scope the project.

Client Benefit

NTH’s experience with the inspection, repair, and maintenance of the Raw Water Tunnel from WWP to NEWTP; and our knowledge of GLWA operations provided valuable insight to the project team during the evaluation of various routes for the new transmission main.