| Work Performed: |
The Alameda Siphon No. 4 project extends approximately 3,000 feet
from the Alameda East portal across both the Calaveras Fault and Alameda
Creek to the Alameda West Portal. The three existing pipelines transmit
water from both Hetch Hetchy and Sunol Valley Water Treatment Plants
to the Bay Area. The project consists of installing a 66-inch welded
steel pipe with 310 feet of a seismically-designed thicker-walled
pipe in the fault rupture zone, 66-inch overflow pipes and San Antonio
backup pipeline. This structure will blend with Sunol Valley water
and Hetch Hetchy water so that the existing and new Irvington Tunnels
will receive a uniform quality of water. |
Alameda
Siphon No. 4