WC-1023 60-Inch Water Main Relocation

As a result of Tinker Air Force Base (TAFB) in Oklahoma City expanding eastward and closing public road access, the existing 60-inch potable water transmission main needs to be relocated. This pipeline is crucial for the City’s water supply, necessitating continuity and reliability. Plummer conducted a holistic pipeline alignment study including an Engineer’s Opinion of Probable Construction Cost (OPCC) using AACE Class IV methodology. We also evaluated stormwater runoff from adjacent industrial sites, and environmental concerns. Due to significant sandstone presence, we expedited drilling 14 preliminary bore holes to understand subsurface conditions and mitigate excavation issues.

Plummer designed four miles of a 60-inch steel transmission water main to meet current and future demands and support TAFB’s growth, with work being completed in two phases. Recognizing the lack of storage and the necessity to maintain a continuous water supply to the community, we developed a plan to complete the tie-in during the winter of 2025/2026. This work will be performed live during low demand periods to minimize disruption. A bypass will be used to maintain critical flow to local hospitals and to the downtown business district. Managing risk during this task is vital and requires that the selected contractor has the proper equipment and experience installing large diameter pipe while operating under a by-pass. To do this, Plummer collaborated with the City to develop two questionnaires to pre-qualify contractors to bid on Phase 2 work. Coordination with the roadway contractor is essential, as both projects occur simultaneously, requiring careful scheduling.

Due to the project’s complexity, costs exceeded the City’s original internal budget. Plummer performed value engineering to manage costs without increasing future maintenance expenses and is providing a full-time Resident Project Representative for pipeline installation.