A huge segment of the $4.6-billion Hetch Hetchy Water System Improvement Program (WSIP) is about to head in a downhill direction.
The San Joaquin Pipeline System (SJPS), part of the San Francisco Public Utilities Commission’s WSIP to repair, replace and seismically upgrade the aging Hetch Hetchy Water System, has reached several major milestones over the last several months.
According to officials at the San Francisco Public Utilities Commission (SFPUC), notices to proceed were issued this quarter for the eastern segment contract, which involves the construction of a new pipeline from the Oakdale Portal to a new connection point 6.7 miles from the San Joaquin Pipeline No. 3, as well as associated structures. The project was awarded to Contri Construction in June.
This is the third and final contract of the SJPS system, meaning all of the water system improvement projects are now in construction.
“We have the entire project contracted so the issue now is managing these contracts so we don’t have too great of an impact on our neighbors or system operations,” said Chris Nelson, project manager, SFPUC. “This system delivers 85% of the water to SFPUC’s customers, and we have restricted opportunities to coordinate shutdowns to tie new facilities into the old ones. It all has to run like clockwork.”
In addition, the Tesla Treatment Facility Project is now complete. The project involved the installation of a new 78-inch diameter pipeline from the San Joaquin River to the Tesla Portal. The 10.3-mile pipeline had to cross several irrigation districts, highways, a railroad crossing, an irrigation canal and the California Aqueduct.
The Tesla Treatment Facility Project also involved the construction of a new ultraviolet water treatment facility and a new chemical water treatment building, an operations building, tanks and other support structures. The new water treatment facility is the third largest in the U.S. with a capacity of 315 million gallons per day. The new facilities replaced 75-year-old structures, which did not meet earthquake standards.
The $70-million SJPS is just one part of SFPUC’s Water System Improvement Program (WSIP), which in total includes more than 80 projects across six counties from the Central Valley to downtown San Francisco. The SJPS consists of three large pipelines and one crossover facility that convey Hetch Hetchy water from the Foothill Tunnel near Oakdale on the east, 47.5 miles across the San Joaquin Valley to the Coast Range Tunnel on the west. Over the years, the delivery capacity of these pipelines has been reduced from their original capacity of 300 million gallons per day due to deteriorating linings, according to Nelson.
“The project will improve water delivery reliability and maintain water supply by reducing the amount of time any part of the system is shut down for maintenance and by improving the system’s water supply capacity,” Nelson said.
Naturally, a project of this scale has produced numerous challenges. Crossing the irrigation districts has been a significant test, according to Bruce Stephan, regional construction manager, PMA Consultants LLC, as well as the fact that the San Joaquin Valley is an enormous agricultural area.
“In contrast to most other WSIP projects in highly-populated, urban centers, the location of this project means working in sparsely populated, agricultural land,” Stephan said. “The team is working with farm owners and irrigation districts to coordinate construction activities with farm irrigation needs.