Wednesday, December 28, 2011

Not your ordinary Holiday Mixing

Here at Calaveras Dam, we are not mixing your typical holiday cookie dough. For 24 hours a day and 5 days a week, our project teams have been mixing soils for site stabilization. This process is necessary to stabilize the foundation of our disposal area for excavated materials in order to construct the dam.

Deep Soil Mixing is a soil treatment where soil is blended with cement and existing materials. In deep soil mixing, powerful augers are used to mix slurry, thereby stabilizing it for construction purposes. Below are photos of our work, day and night.




For more project info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Tuesday, December 6, 2011

The SFPUC and the Town of Sunol Celebrate the Holidays

Pizza, cider and rock samples! The SFPUC’s Holiday Open House at the Sunol Event Center was the place to be last Thursday night!

Sunol residents mingled with their neighbors and engaged in lively conversations about the history of the valley with SFPUC staff. Guests played with rock samples from the Calaveras Dam, marveled at construction photos of the New Irvington Tunnel and enthusiastically shared their vision for the proposed Alameda Creek Watershed Center.


Residents also had the opportunity to learn about other ongoing projects in the area including: the San Antonio Backup Pipeline; San Antonio Pump Station; Alameda Siphon #4; Sunol Valley Water Treatment Plant; Town of Sunol Fire Suppression System; and the Watershed and Environmental Improvement Program and Bioregional Habitat Restoration Program.


The smell of homemade banana bread and hot apple cider filled the air as guests enjoyed freshly baked artisan pizzas topped with locally grown vegetables from Fred Hemple and Jill Shepard’s Baia Nicchia Organic Farm. Our youngest guests decorated their own ornaments and bookmarks.

Thank you to those who were able to attend our holiday event.

To all of our neighbors in the Sunol Valley and folks we’ve had the pleasure of working with this year, we want to wish everyone a very happy holiday season!

Monday, November 28, 2011

Sunol Region Holiday Open House

Drop into the SFPUC’s Sunol Region Holiday Open House for a celebration of the holiday season and the coming New Year! Come meet representatives from all of our projects in Sunol Valley. They look forward to chatting with you about all the work we are doing.

Light refreshments and activities for kids will be provided.

Thursday December 1, 2011
6:00 p.m. to 8:00 p.m.
Sunol Event Center
11684 Main Street

Monday, November 21, 2011

Ready for Rains

It’s been wet out there, lately. As the Calaveras Dam Replacement Project begins construction, the team is ready for winter rains. The contractors must be prepared to treat storm water runoff to protect the local creeks. Large areas of exposed ground created as part of construction have the potential to erode soils and impact the water quality downstream. The project has installed a treatment system to protect the local creeks. The treatment consists of removing any silts and clays that may be eroded from exposed excavation surfaces. The contractor has installed an active treatment system that consists of retention ponds and sand filters to clean turbid waters prior to discharging back to the Calaveras Reservoir. The treatment system is designed to manage a flow up to 2,400 gallons per minute, equivalent to approximately 57 bath tubs filled with water.


The treatment system is prepared to operate around-the-clock for the duration of the four year project. We currently anticipate treating approximately 270 million gallons water. As the project prepares to move over 7 million cubic yards of earth over the next four years, the treatment system and other erosion control features will help maintain the water quality in the Alameda Watershed.


For more info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Tuesday, November 15, 2011

New Irvington Tunnel: A Year in Construction

The New Irvington Tunnel Project celebrated its first year of construction this past September. When complete 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. Take a look at the important work taking place above and below ground:



Year One by Numbers:

1 Tunnel Shaft: At 115-feet deep and 41-feet diameter, the Vargas Shaft is the starting point for two of the tunnel headings.

2 Tunnel Portals: Carved into hillsides between Sunol and Fremont the Alameda West and Irvington Portals are access and exit points for the new tunnel.

3 Road Headers: Weighing in at a combined 127 tons these mechanical tunneling machines are grinding their way through 3.5 miles of rock.

76 Secant Piles: Drilled and poured 115-feet into the ground this interlocking circle of piles form the support for the Vargas Shaft.

3057 Feet to Date: Miners have excavated this total from 4 tunnel headings.

Thursday, November 10, 2011

Welcome to our Headquarters


Frequent cyclists and commuters along Calaveras Road may notice new office trailers, nestled in the hills, approximately 7 miles from Highway Interstate 680. This is the official new home to the Calaveras Dam Replacement Project Team. The team has been working at the site months before the official trailers were completed in early November. Over 40 employees work daily out of the Calaveras trailers.

About the Team
Dragados USA, Inc./ Flatiron West, Inc./Sukut Construction, Inc. Joint Venture, combines international experience building dams around the world. Black and Veatch serves as the construction management firm for the project. Together with the SFPUC, the firms integrate a team committed to the sustainable development of California’s water projects.

As the largest project in the Water System Improvement Program, the Calaveras Dam Replacement Project team will replace the existing dam with a 220-feet high new seismically-designed, earth and rock-fill dam directly adjacent to the existing structure, restoring the reservoir to its historic water storage levels. All construction activities are expected to be complete in late 2015, and the project will reach final completion in 2016.

For more info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Wednesday, November 2, 2011

Four Steps to Protecting Water

A hydrogeologist collects groundwater data

In the hills between Sunol Valley and Fremont, the water that flows between the cracks and faults underground is worth more than gold. For nearly every property owner, it is their only source of water for drinking, agriculture and fire protection. It goes without saying that residents are very protective of their only water supply.

In the late 1920s, the construction of the existing Irvington Tunnel caused water levels in many wells, ponds and springs to drop. Fast forward to the present day and now you have an aging water system in serious need of a seismic upgrade. How did the New Irvington Tunnel project team come up with plan to protect water supplies? Here are the 4 steps:

1. Understand the problem“We understand the problem” said the project manager and engineers. Hydrogeologic experts were hired to study the groundwater table, and quantify and forecast the problem with a sophisticated groundwater model. Using the model the project team has identified which residents may be affected and developed measures to offset any possible water supply interruption for each resident. "We are concerned about the loss of groundwater too!”

2. Share your knowledge “Tunneling techniques have greatly improved over the past 80 years” said mining engineers and tunnel designers. Our team of experts described to the public how probe drills bore ahead of tunnel excavation to find pockets of water. If water is found, these holes are filled with grout keep the water from flowing into the tunnel.

3. Come up with a plan“What if I still lose water?” asked many property owners. A groundwater management program was developed by the project team. In addition to water monitoring, each property owner received a site specific plan detailing the steps the project team will take to prevent an interruption in water supply.

4. Keep your commitments – No matter how well the first three steps were received this last step is what people will remember. Did we do what we said we were going to do? The jury is still out, however, since we started the program hydrogeologists have monitored water levels and shared the information with property owners. Regardless of the time of day or day of the week the project team responds when a property owner thinks there is an issue with their water supply. This week, construction crews are installing measures designed to prevent an interruption in water supply.

The project team’s work is far from complete, however, the groundwork has be laid to protect local water supplies. As tunneling progresses, groundwater monitoring will intensify and the team will continue to be ready to respond.

Tuesday, November 1, 2011

Tarantula Crossing

Fall is tarantula time at the Calaveras Dam project site. The annual ‘tarantula migration’, which, begins in September through end of fall, is underway. Normally shy, living underground in burrows, and nocturnal, these hairy spiders are making their yearly journey above ground. The male tarantulas are migrating across our lands in search of female tarantulas to breed, and then the males scurry home in fear of being eaten by their new female companions. As part of our continuing efforts to protect wildlife, you will see many of our workers driving slow enough to stop and let the hairy critters cross the road, evident in this photo taken by our staff.

These hairy, eight-legged creatures have been feared by many. In reality, tarantulas have never caused any human deaths and are only dangerous to small insects. Tarantulas have very small venom glands and the bite of our tarantula is compared to a bee sting. Harmful spider bites generally come from poisonous spiders of other species. Although we wouldn’t want to find them inside the office trailers, we’re glad to yield to them on the roads outside.


For more info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Photo courtesy of Bill Stagnaro, Environmental Inspector & Biologist

Monday, October 24, 2011

Holy Cow! It’s Cattle Fencing.

If you ever had the opportunity to drive along Calaveras Road in Alameda County, you may have noticed a number of cows and calves along the hillside. In preparation for work on the Calaveras Dam Replacement Project, the project included the installation of additional cattle fencing to harbor and protect the cattle, which was completed in September 2011. In addition to cattle, the fencing protects other wildlife species from entering the construction site.


The Calaveras Dam Replacement Project, as well as other Water System Improvement projects in Sunol Valley, work side by side with these animals. These lands have been grazed by cattle for over a century. The SFPUC is on the leading edge of research into the benefits of responsible cattle grazing to watershed lands.


Properly managed livestock grazing has many benefits: reduces fire hazards by controlling the amount and distribution of grasses, benefits plant life by controlling non-native species growth, benefits wildlife by diversifying various species’ habitats while providing natural vegetation management.


For more info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Friday, October 21, 2011

The Modern Day Canary: A Handheld Gas Detector

When the existing Irvington Tunnel was constructed miners might have used canaries to warn them of dangerous gases.


Meet the modern day canary. Like its feathered forbearer it alerts miners to presence of dangerous gasses underground. However, instead of wings and a beak, today’s canary- a handheld gas detector is encased in rugged rubberized armor and has ultra-bright LED alarms.


Handheld gas detectors are operated by a certified gas tester that accompanies each tunnel crew underground. The modern canary tests for oxygen content, hydrogen sulfide, carbon monoxide, carbon dioxide, nitrogen dioxide and explosive gases like methane. If certain levels explosive or hazardous gases are detected then LED lights flash and an audible alarm is sounded.

Gas levels dictate the strict safety procedures the crews follow. If gas levels are detected at 10% LEL or Lower Explosive Limit, then steps are taken to increase ventilation in the tunnel. Work can continue but must be performed with extra care. If gas levels reach 20% LEL then electric power is shutdown and miners must evacuate the tunnel.

Safety comes first inside of the New Irvington Tunnel. Miners take great care to check their surroundings when operating hundreds of feet below ground. For the risks they can’t see with the naked eye, the modern canary- a handheld gas detector has their back.

Monday, October 17, 2011

Calaveras Critters: Nurturing Nature at the Calaveras Dam

Major construction is complicated in any setting, as well as in watershed lands that harbor rare and endangered species, it is doubly so. Members of the Calaveras Dam Replacement Project Environmental Team are on site every minute of every day to ensure that our construction activities do not harm these precious plants and animals. Case in point – last week monitors on site found a juvenile threatened Alameda Whipsnake. It took four specially-trained personnel a long time to carefully capture and move the animal to a safe pre-determined release location far away from construction.


The SFPUC owns and manages approximately 36,000 acres of the Alameda Creek Watershed. The Watershed contains grassland and oak woodland communities that support a wide range of animals including Special Status Species.

Environmental Compliance Manager Cullen Wilkerson, a U.S. Fish and Wildlife Service and California Dept. of Fish & Game approved Biologist, handled the Alameda Whipsnake and relocated it safely to a new habitat nearby.


Alameda Whipsnake (Masticophis lateralis euryxanthus)
Federal Status: Threatened
State Status: Threatened

Description: A slender, fast-moving snake 3 to 4 feet in length with a slender neck, broad head and large eyes. Back is colored sooty black with a distinct yellow-orange stripe down each side.

Habitat: An active daytime predator, adult snakes peak in surface activity during the spring mating season with a smaller peak during late summer and early fall. Rock outcrops are important for retreat opportunities. Generally retreats in November into a small mammal burrow or other shelter, and emerges in March.

For more info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Friday, October 14, 2011

Grinding Forward


Tunnel crews are grinding their way forward on the New Irvington Tunnel Project. Miners excavate in four directions using road headers (tracked tunneling machines) and controlled detonations when necessary to dig out the 18,600-foot (3.5 mile) tunnel.

Over 2000 feet of tunnel has been excavated with approximately 16,600 feet remaining. Last Friday tunnel crews dug out a new daily record of 50 feet for the project. As the crews become more familiar with and how to deal with the variable ground conditions, the mining production has steadily improved each week. Tunnel excavation is estimated for completion in mid-2013 with project completion in mid-2014. Check out www.sfwater.org/nit for weekly updates of tunnel progress.

The New Irvington 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. The new tunnel will lay parallel to the existing tunnel between the Sunol Valley south of Highway I-680 and Fremont, California.

Monday, October 10, 2011

Calaveras Dam Replacement Project Update



Road Closure Update
We have received permission from Alameda County to temporarily close Calaveras Road south of Geary to the Alameda/ Santa Clara County Line for two separate periods
- The first two-month road closure, initially planned for fall 2011 is now planned for early 2012.
- The second road closure is expected in late 2012/early 2013 for a period of 18 months.
- Calaveras Road will remain open on weekends, but will be closed Monday-Friday during these periods.
- Access to the Sunol Wilderness will remain open
from the north at all times and from both the north and south on weekends.
- Emergency vehicles will have access to the road at all times.
- The roads will be swept clean of debris prior to weekend openings.

Calaveras Dam – Controlled Detonation
The contractor will be using controlled detonation to produce the hard rock required for construction of the dam. To excavate the foundation of the dam, we may encounter rock that is too hard for our machinery, in which case we may also use controlled detonation. You may hear the detonation or feel minor vibrations from the activity. If you would like to receive an email notification beforehand, please contact Maria Le at mle@sfwater.org.

If you have any additional questions or concerns, call our 24-hour answer line at (866) 973-1476.

Wednesday, October 5, 2011

Share the Road: One Road, Many Users


Construction activity is now underway for the Calaveras Dam Replacement Project. Safety is our #1 priority.

Please be cautious of the large trucks and increased traffic along Calaveras Road, specifically south of I-680. Due to the narrow road conditions, please remember to ride and drive safely through the blind curves. The speed limit is 25 mph in construction zones.

We understand this is a popular route for bicycling enthusiasts and we hope we can all share the road safely. Please note that Calaveras Road will be closed for 2 periods. The first closure has been postponed until early 2012. Please check back here for updated road closure info.

Feel free to contact us at any time at 24 hour answer line at (866) 973-1476, or mle@sfwater.org. Thank you for sharing the road!

Tuesday, October 4, 2011

Then and Now

The existing Irvington Tunnel was built in the early 20th century and can no longer be taken out of service for repairs or maintenance without impacting the water supply to customers. The New Irvington Tunnel is designed to provide a seismically-strengthened or reinforced connection between water supplies from the Alameda Watershed to Bay Area customers.



The Alameda West Portal in August of 1929. Miners excavated the existing Irvington Tunnel between 1928 and 1931 primarily using drill and blast techniques.


The Alameda West Portal in April of 2011. Miners are using road headers (conventional tunneling machines) and limited controlled detonations to excavate the tunnel. The project is expected to be completed by mid-2014.

Tuesday, September 27, 2011

NIT: Extended Construction Hours

Update
Beginning on October 3, 2011 through May 9, 2012, the contractor is authorized to conduct construction activities 24-hours per day 7-days per week at the Irvington Portal in Fremont, as may be necessary to complete time critical work for the New Irvington Tunnel connections to the existing Bay Division Pipelines.

What Can I Expect?
On weekdays from 7AM to 7PM and weekends from 8AM to 5PM construction activities will focus on the crane placement of new pipe and be similar to what is currently being experienced. Outside of those hours the contractor will work on connecting and welding of pipe at the new tunnel. The operation of construction equipment (loaders, excavators and cranes) is necessary to complete this work. Worker trips to and from the site at shift changes will also take place. Tunneling is not allowed after 7PM on weekdays and 5PM on weekends. An effort will be made to complete all the work during daylight hours, and minimize work during the evenings and nights.

Will Work Take Place During the Holidays?
The contractor does not currently plan to work on Thanksgiving, Christmas or New Years Day. However, they have the ability to work on those days in order to complete their work within the extended work hour period. Residents will receive advanced notice if it becomes necessary to work on those days.

Why are Extended Hours Necessary?
This work can only be completed during the winter seasons when water demand is at its lowest. It is imperative for the contractor to finish his work and re-establish full capacity water service before water demand increases in the warmer months of Spring. In order to do this, the existing waterlines are cut out for the tunnel connections only one at a time, leaving other waterlines in service. The waterlines are drained and cut out and new connection waterlines are installed. Water service will not be impacted because there is redundant capacity in the pipelines during the winter seasons.

Questions?
Please call our 24-Hour Answer Line at 866.973.1476 or visit sfwater.org/nit if you have questions or comments.

Monday, September 26, 2011

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.

Monday, September 19, 2011

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.

Tuesday, September 13, 2011

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.

Thursday, September 1, 2011

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.


Wednesday, August 24, 2011

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

Friday, August 12, 2011

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!

Wednesday, July 27, 2011

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!

Thursday, June 30, 2011

New Irvington Tunnel in the News!

In print and on camera, everyone wants to know more about the New Irvington Tunnel. Check out the amazing photos of the past and present day construction and detailed exhibits in June 2011 issue of Tunnels and Tunneling International. READ ARTICLE

Next take a tour with Tunnel Talk and watch their coverage of the Rapid Excavation and Tunneling Conference’s (RETC) up close look at the New Irvington Tunnel. WATCH VIDEO.

Wednesday, June 29, 2011

Tunneling at Irvington Portal has Started

Update
On June 20, Southland/Tutor Perini JV began tunnel excavation from the Irvington Portal in Fremont. The contractor will advance the tunnel using a road header (a tracked tunnel excavator) and controlled detonation if necessary depending on the rock conditions. Other construction support equipment will load and haul the excavation spoils from the site to a disposal area on Calaveras Road in the Sunol Valley.

Controlled Detonations
If the road header encounters harder than anticipated rock conditions underground, the use of controlled detonations may be necessary. This involves the use of small amounts of explosives to fracture the rock material so that it can be removed by the tunnel machinery. Safety horns would be sounded a set period of time before each event. We will monitor to ensure that controlled detonations comply with all local, state and federal safety, noise, and vibration requirements. Controlled detonations are only allowed to occur Monday through Friday between 7:00 AM and 7:00PM and on Saturday between 8:00 AM and 5:00 PM. No more than two controlled detonations are anticipated per day on the days that controlled detonations are needed. But most of the excavation is anticipated to be successful by the road header alone.

Notification
Due to the nature of tunneling, it is challenging to predict far in advance when controlled detonations would be necessary. The SFPUC will provide residents with advanced e-mail notification of controlled detonations as early as possible (24 hours minimum). To receive e-mail notifications of controlled detonations, please send a message to fzamora@sfwater.org.

Residential Construction Surveys
Many residents exercised their option to have photographic and video surveys of their property prior to construction. These surveys document existing cosmetic and structural cracks for each property and are used as basis for evaluating claims of new damage caused by construction activities. If you have not had a survey conducted please contact the SFPUC as soon as possible, we may conduct surveys until July 6, 2011. Please call 866.973.1476 and reference the New Irvington Tunnel Project or e-mail fzamora@sfwater.org to schedule a photographic and video survey.

Questions?
Please call our 24-Hour Answer Line at 866.973.1476.

Thursday, June 2, 2011

Calaveras Dam Replacement Project Construction Contract Awarded

The construction contract for Calaveras Dam Replacement project was awarded on May 24, 2011 to Dragados, USA/Sukut Construction, Inc./Flatiron West Inc. joint venture for approximately $259 million.

Thursday, May 19, 2011

KTVU Video: New Irvington Tunnel Project Underway

Want to take an exclusive look at the New Irvington Tunnel? Check out KTVU Channel 2's sneak peak at the construction taking place to seismically upgrade the aging Hetch Hetchy Water System.

http://www.ktvu.com/video/27877116/index.html

Friday, April 15, 2011

Construction Moves Forward for Improvements at the Sunol Valley Water Treatment Plant

Construction is moving forward for the Sunol Valley Water Treatment Plant Expansion and Treated Water Reservoir Project. As of April 2011, construction for the overall project is 25 percent complete. Recently the contractor, Shimmick Construction Company, Inc., completed the extensive earthwork and soil nail wall required to build the new treated water reservoir, which included the removal of over 400,000 cubic yards of material. This work is part of various improvements that will enable the treatment plant to treat enough water to meet basic customer demands alone for up to 60 days after a major earthquake as well as improve water quality at the plant. All these improvements are expected to be completed in summer 2013.


Workers finish securing the soil nail wall, which will help stabilize the treated water reservoir. Photo courtesy of Robin Scheswohl.

The excavation work for the treated water reservoir included the removal of over 400,000 cubic yards of material. Photo courtesy of Robin Scheswohl.

Thursday, March 17, 2011

Tunneling Begins

On Friday, March 11, the AQM 150-HR Roadheader began grinding its way west and has reached a distance of 25 feet. Tunneling will pause for approximately a week to complete the installation of the portal yard, ventilation and permanent power. Railroad tracks will also be installed behind the road header. The tracks are needed because as spoils generated they are collected on a conveyor belt and loaded onto rail cars for transport outside of the tunnel.

When tunneling resumes the roadheader will travel an average of 22 feet per day until it reaches the Vargas Shaft (14,300 feet away). A sister roadheader headed in the opposite direction will rendezvous with the machine sometime in 2013.

The roadheader’s boom-mounted cutting head that hacks away at rock face.

The boom-mounted cutting head is capable of excavating the 13-foot horseshoe shaped dimensions of the tunnel.

The Roadheader starts its journey from the Alameda West Portal

Spoils generated are collected on a conveyor belt attached to the roadheader and loaded onto rail cars for transport outside of the tunnel.

Thursday, March 10, 2011

@ Work: Deeper at Vargas

The Vargas Shaft gets deeper everyday and will soon reach its final depth of 120 feet. Here are some photos of the shaft at various stages. Feel free to guess the depth of the shaft and post your answers in the comment section. Sign up for the blog and we will send you the answers.

February 22, 2011: __ feet


Both photos on March 4, 2011: ___ feet

March 10, 2011: __ feet