The San Francisco Public Utilities Commission (SFPUC) proposes to construct a new water transmission tunnel parallel to the existing Irvington Tunnel between the Sunol Valley and the Mission District of Fremont.  The proposed tunnel would be about 3.5 miles long, with a finished internal diameter of about 9 feet, and would range in depth from 150 to 700 feet underground.

The SFPUC held a public meeting in Fremont in June 2006 to discuss the proposed project. Since then, the project team has been doing geotechnical investigations in the area of the proposed tunnel alignment.  In essence, crews drilled core samples of the ground through the proposed tunnel alignment and analyzed them to learn more about the ground conditions. 

The project team has made design changes to the proposed tunnel in response to the preliminary results of these investigations. The attached fact sheet explains what those proposed changes are.

Questions/ Comments?
Betsy Lauppe Rhodes
415-554-3240
blauppe@sfwater.org