Let the Digging Begin: New Calaveras Dam Breaks Ground

On September 16th, General Manager Ed Harrington joined local and state officials to break ground on the construction of the Calaveras Dam Replacement Project. The 4-year, $416 Million dam is one of only several major dams built in California in 30 years. Alameda County Supervisor Nadia Lockyer and Sharon Tapia from the California Department of Water Resources, Division of Safety of Dams were on hand along with neighbors and project supporters. The contractor cut the first notch into the existing dam since it was originally built in 1925.




The Calaveras Dam Replacement Project will replace the existing dam with a 220-feet high new seismically-designed earth and rock-fill dam that will be constructed right next to the existing one. The Calaveras Dam Replacement Project is part of the SFPUC’s $4.6 billion Water System Improvement Program (WSIP) to repair, replace, and seismically upgrade the aging pipelines, tunnels and reservoirs in the Hetch Hetchy Regional Water System.

Dedicated to Safety: Tunnel Rescue Team

Excavating a tunnel is dangerous business. Skilled miners put their lives at risk every time they go underground, in conditions that may expose them to grounds that cave in, flammable gasses and groundwater that might pour in and flood the tunnel. Protecting the safety of our workers is the top priority of the San Francisco Public Utilities Commission (SFPUC) and Southland Tutor Perini Joint Venture (STP). Should the unthinkable happen and miners need a rescue the Tunnel Rescue Team is ready at a moment’s notice.


Tunnel Rescue Team members are highly trained specialized tunnelers who put themselves directly in harm’s way to come to the aid of their colleagues. They are trained to enter a tunnel under hazardous conditions that would prohibit most people from entering to provide first aid, extract personnel, or put out fires.


At the New Irvington Tunnel (NIT), the Tunnel Rescue Team is a 13-member team on-call 24 hours-a-day 7 days-a-week. A back up tunnel rescue team from the Caldecott Tunnel Project is also available. First responders from CalFire and the Alameda County and Fremont Fire Departments support the Tunnel Rescue Team above ground.


The Tunnel Rescue Team practices and drills regularly to ensure their skills are ready when needed. We sincerely hope that their services will never be needed. But if they are, the NIT team invests time each day to be sure we are ready to protect the lives of the workers who are helping to ensure a reliable water supply for all of us.

Congratulations! It’s a… Killdeer!

The New Irvington Tunnel Project was home to the birth of four killdeer birds. Native to California, the killdeer nest on level surfaces of sand or stones. True to its natural behavior a female killdeer was found nesting on a dry streambed- within 100 feet of bridge that was about to be demolished!




Great care is taken to protect all wildlife our project teams come in contact with as they rebuild and seismically strengthen the Hetch Hetchy Water System. The killdeer are North American birds protected under the Migratory Bird Treaty Act and the New Irvington Tunnel’s Environmental Impact Report. While workers were preparing to demolish a temporary bridge and build a new one, environmental inspectors were busy devising measures to monitor and protect the mother killdeer and her unborn hatchlings.


Inspectors monitored the nest daily. Each time the inspectors made sure all the eggs were still in place and the mother was incubating. To further protect the killdeer, workers shifted the main construction road 25 feet and established a no disturbance buffer of 25 feet around the nest. The nest was then surrounded by a wildlife exclusion fence. Signs were posted around the fencing that read “Bid Nesting Area, Keep Out”.


After three weeks of daily monitoring the big day came when the mother killdeer hatched four eggs. Within the next couple of days the young killdeer fledged and were ready to explore their new world. As for the workers and the inspectors, they were delighted all four killdeer were healthy. Once the killdeer moved on and out of the project area everyone could get back to the vital construction of the New Irvington Tunnel.

A Different Kind of Tailgate Party

Early Monday morning the men and women responsible for building the New Irvington Tunnel have one thing in mind: SAFETY. Why? Because construction can be a dangerous profession and working underground adds to the risk. This is why safety is paramount for the San Francisco Public Utilities Commission (SFPUC), the Water System Improvement Program (WSIP) and Southland/Tutor Perini Joint Venture (STP).


Safety is important every day, however, Tailgate Meetings kick off every work week for all construction personnel working onsite. It gives safety managers and construction superintendents the opportunity to reinforce safe work practices. For example, when discussing fall protection, presenters demonstrate the proper use of personal protective equipment. Workers are also reminded to strap in when they are elevated over six feet. The presentations are designed so workers think safety before, during and after any activity. Other safety topics include first aid, emergency tunnel rescue and chemical handling.

Tailgate Meetings are just one tool (incidentally they are also called Toolbox Meetings) used to promote STP’s proactive safety culture. Signs posted through out the site are another way of encouraging workers to think and practice safety. Future blog posts will go into more detail about a number of safety related topics such as emergency tunnel rescue and gas testing and training.

Construction Progress: What a Difference a Year Makes!

Construction for the Sunol Valley Water Treatment Plant Expansion Project is moving forward rapidly and is now 44 percent complete. This summer the contractor has made significant progress. The contractor has finished all preparations and started micro-tunneling underneath Alameda Creek to build a new pipeline that will connect to the treatment plant. Also crews have made significant progress with the new 17.5 million-gallon circular treated water reservoir, including completing the installation of the concrete floor slab. Inside the treatment plant, a new treatment train is beginning to take shape. All of these elements together will help boost the overall efficiency of the treatment process at the facility, improving reliability and water quality.

See the photos below that show progress on the treated water reservoir that will act as a balancing reservoir for water as it leaves the plant:

September 2010

The early stages of excavation for the treated water reservoir

August 2011

The treated water reservoir takes its circular shape

Treated Water Reservoir Construction By the Numbers:
• 400,000 cubic yards of soil removed to construct it
• 40,000 cubic yards of concrete to build it
• 1,482 soil nails to secure it
• 1,160 piers drilled underneath it for seismic safety
• 2-3 feet thick floor slab installed

Sustaining the Environment at the New Irvington Tunnel

The seismic upgrade and expedited delivery of the New Irvington Tunnel is crucial to maintaining a consistently reliable, high-quality water supply for 2.5 million Bay Area residents. Engineers and construction and mining professionals work daily to achieve this goal. The San Francisco Public Utilities Commission (SFPUC) is equally committed to remaining environmentally responsible, and is working in collaboration with environmental scientists to ensure the work is done in a timely manner and environmentally sustainable manner.

Before construction could begin at any of the three tunneling sites, the SFPUC took numerous measures to ensure that environmental impacts are kept to a minimum on the project sites. One measure used to protect wildlife is to install wildlife exclusion fencing around each of the work sites. The black 4-foot high fabric fencing deters wildlife from entering the construction sites and is monitored for its integrity on a weekly basis.


The fence won’t discourage all wildlife. For our winged neighbors, an environmental monitor scours work sites for any signs of nesting birds. Initially, monitors try to discourage birds from establishing nests on site. However, if they encounter a completed nest, construction zones are altered or activities are postponed in that area until all the nesting birds have fledged or left the nest.

Protections against erosion and storm water run-off are also required. On the exposed slopes at all three tunneling sites, workers laid down wattles ( which are woven netted tubes filled with straw) to help prevent soil erosion. Wattles are laid down perpendicular to the slope, and when combined with other practices (such as mulching), prevent or slow down the effects of stormwater runoff.

Mulch is also applied to the hillsides to prevent erosion, through both a process called hydro-mulching and by manual methods. Hydro-mulch, which consists of recycled natural fibers combined with a tackifying agent, is sprayed onto the hillside and coats the soil. Straw is also manually laid down onto the slope. To help the vegetation grow, seed is added to the mulch mixture and applied to the slope through a process called hydro-seeding. As the vegetation grows, the mulch decomposes into the soil and the vegetation itself stabilizes the slope and prevents rain from directly falling on the soil and producing erosion.


Finally, all three of the tunneling sites are monitored daily by SFPUC environmental inspectors and specialty monitors. They verify that workers are in compliance with the environmental standards set by the SFPUC and environmental permitting agencies to maintain a healthy environment!

Where Are We Now? New Irvington Tunnel Update

At the largest work site, Alameda West Portal, workers are maintaining steady progress. They began last week at a distance of 607 feet, but with the help of the robust roadheader and the highly efficient locomotive removing spoils from inside the tunnel, they were able to increase their distance by 48 feet and end the week strongly at 655 feet.



Tunneling began just over a month ago at Irvington Portal off of Mission Blvd. and work is rapidly progressing. On Monday of last week, workers continued from the previous week at a distance of 82 feet. With lots of hard work and the help of the roadheader grinding away, they ended on Friday at 146 feet. That’s an additional 64 feet in just one week!



Just off the 680 freeway lies the Vargas Shaft, where work began in early 2011. Tunneling has stopped for the moment as workers are busy drilling drain holes to discharge excess water from the tunnel, which will allow for easier tunneling. Tunneling will hopefully resume this week after which workers will be headed westward!