Mission Trails Pipeline Tunnel & Vent Demolition

Project Description

The scope of this estimate covers cost of construction and demolition of the San Diego County Water Authority (SDCWA) Mission Trails Pipeline Tunnel and Vent Demolition Project. This project will provide for future increased untreated water demands and storage capacity for Central and South San Diego County. Construction of the pipeline will relieve a "hydraulic bottleneck" in the system by combining the existing Pipelines 3 and 4 into a single pipeline to transmit untreated water through the proposed Mission Trails Flow Regulatory Structure II. The pipeline is designed as a pressure pipeline with an impermeable lining in two separate tunnel.

Project Highlights

• Construction of approximately 4,825 lineal feet in two separate tunnels to install 92" welded steel pipe or 96" reinforced concrete cylinder pipe, at the Contractor's option.
• Construction of two shafts totaling approximately 212 lineal feet with a vertical riser from the tunnel grade to a point below the ground surface.
• Construction of approximately 305 lineal feet in two separate pipelines comprising 92" welded steel pipe, each from a tunnel portal to a point where a connection to the P3 pipeline is to be made under separate contract.
• Demolition of Elliott Vents 1 through 5 on existing pipelines P3 and P4.