The SFPUC took an important step forward towards the construction of the New Irvington Tunnel. The Southland/Tutor Perini Joint Venture and their subcontractor Malcolm Drilling drilled the first of 76 secant piles for the 120-ft deep Vargas Shaft. Secant piles are 39-inch concrete filled piles that provide support for the excavation of the shaft. When complete, the 41-ft diameter Vargas Shaft will be a starting point for tunneling activities.
The New Irvington Tunnel will run 3.5 miles and have an internal diameter of approximately 8.5 to 10.5 feet. The new tunnel will provide a seismically-designed connection between water supplies from the Sierra Nevada Mountains and the Alameda Watershed to Bay Area water distribution systems.