New Irvington Tunnel Neighbors compete in the Final Tunnel Hole-Through Challenge at Open House

Last week, neighbors of the New Irvington Tunnel project stopped in for a cup of coffee and to hear the latest updates on tunnel progress at Mission Coffee House in Fremont.  Attendees were able to discuss construction progress, see new project photos, handle some rock samples collected from tunneling, and participate in the final "hole-through" challenge. 

 Residents participate in the Tunnel Hole-Through Challenge

We are still anticipating the exciting moment when the miners will meet underground between the tunnel segment from Vargas East to Alameda West Portal.  The winner will be notified to receive their gift basket of local goodies as soon as the day comes.  Thank you to all who have participated in the New Irvington Tunnel Hole-Through Challenge!  

Our final guesses are shown here:

For more project info, please email mle@sfwater.org or call our 24 hour answer line 866-973-1476.

One more week to play! New Irvington Tunnel Challenge

Sometime in the next few weeks, two teams of miners will meet hundreds of feet underground. One is excavating the New Irvington Tunnel eastward from the Vargas Shaft near I-680; the other is working its way west from the Alameda West Portal in Sunol Valley.

When will they meet?

Guess correctly and you could win a wonderful prize pack featuring gift certificates to local businesses!

Need a little help?

As of September 14, 2013, our miners have tunneled 5,044 feet east from Vargas and 8,758 feet west from Alameda West. In ideal ground conditions, crews have tunneled an average of 130 feet per week. When ground conditions are poor they excavate less than 20 feet. We have 405 feet left to go to hole-through as of September 14, 2013.

How to Play

The chart squares shown below correspond to a possible date and timeframe when the tunneling teams will meet. Selections already submitted by contestants are indicated by a “star “.

1. Choose three squares and e-mail your choices to: mle@sfwater.org
2. If your first choice is available, then you will be assigned that square. If the square is unavailable, then the next available choice is assigned. You will receive an email confirmation with your selection.
3. Include the date and time you think the hole-through will take place. Squares will be assigned on a first come, first serve. Only one square is allowed per person
4. Please include your name, phone number and e-mail address so we can contact you if you make the winning selection.
5. Submissions will be accepted through September 29, 2013.  GOOD LUCK!

New Irvington Tunnel Project Background

The SFPUC is constructing a new 3.5 mile long tunnel to transmit water between the Sunol Valley and Fremont. The New Irvington Tunnel has been excavated from four different tunnel headings. The first two headings met each other in June 2012. This second and final ‘hole-through’ will mark the completion of excavation of the entire 18,660 ft tunnel. Following the hole-through, miners will prepare the tunnel for the installation of 8.5 ft diameter steel pipe, installed in 50-foot sections and welded together inside of the tunnel. This is a major milestone as the final project completion is near!

Your Challenge - When will our Tunnels Meet?

Sometime in the next few weeks, two teams of miners will meet hundreds of feet underground. One is excavating the New Irvington Tunnel eastward from the Vargas Shaft near I-680; the other is working its way west from the Alameda West Portal in Sunol Valley.

When will they meet?
Guess correctly and you could win a wonderful prize pack featuring gift certificates to local businesses!

Need a little help?
As of September 14, 2013, our miners have tunneled 5,044 feet east from Vargas and 8,758 feet west from Alameda West. In ideal ground conditions, crews have tunneled an average of 130 feet per week. When ground conditions are poor they excavate less than 20 feet. We have 405 feet left to go to hole-through as of September 14, 2013.

How to Play

The chart squares shown below correspond to a possible date and timeframe when the tunneling teams will meet. Selections already submitted by contestants are indicated by a “star “.

1. Choose three squares and e-mail your choices to: mle@sfwater.org
2. If your first choice is available, then you will be assigned that square. If the square is unavailable, then the next available choice is assigned. You will receive an email confirmation with your selection.
3. Include the date and time you think the hole-through will take place. Squares will be assigned on a first come, first serve. Only one square is allowed per person
4. Please include your name, phone number and e-mail address so we can contact you if you make the winning selection.
5. Submissions will be accepted through September 29, 2013.  GOOD LUCK!

New Irvington Tunnel Project Background

The SFPUC is constructing a new 3.5 mile long tunnel to transmit water between the Sunol Valley and Fremont. The New Irvington Tunnel has been excavated from four different tunnel headings. The first two headings met each other in June 2012. This second and final ‘hole-through’ will mark the completion of excavation of the entire 18,660 ft tunnel. Following the hole-through, miners will prepare the tunnel for the installation of 8.5 ft diameter steel pipe, installed in 50-foot sections and welded together inside of the tunnel. This is a major milestone as the final project completion is near!

Feeling Steamy at Calaveras Dam

Among many other fascinating geological features present at the Calaveras Dam project site, a geothermal steam vent has recently been exposed during construction. Although typically associated with volcanic activity, steam/gas vents are also frequently found near large active faults, like the Calaveras fault, which is within 1/4 mile of the project site. There is also evidence of past geothermal activity in the vicinity of this vent. As seen in this photograph, there are areas of hydrothermally-altered bedrock (gray sandstone stained yellow) and holes where former vents, now dormant, were once active.

The construction team continues to monitor the temperature and the gaseous emissions of the present feature, and has created a cautionary exclusion area around it, but, as seen in this video, there has been no adverse effect to construction activity. We will keep you posted on our findings!

The Rim Fire in Yosemite and a Sunol Valley Update

The Rim Fire, which started in the Stanislaus National Forest on Saturday, August 17th, has been widely reported during the past week. The fire has spread to 179,481 acres as of this writing, and more than 3,000 personnel have been dispatched to combat the fire. As of this writing, the fire is 20% contained.

The fire has since spread into the Tuolumne Watershed, and the environs of the Hetch Hetchy Reservoir, which is the source of 85% of the drinking water we provide our 2.6 million customers. There continues to be no change or impact to water quality or delivery from the Hetch Hetchy Reservoir. We continue serving high quality water to our customers.

The water delivery system and the recent upgrades completed in the Sunol Valley as part of our multi-billion dollar Water System Improvement Program have increased our ability to continue to serve our customers even during such an event as this. Why?

• Hetch Hetchy water is being pumped to San Antonio Reservoir in the Sunol Valley as we speak to ensure we have as much water here in the Bay Area as possible, in case Hetchy supplies should become unavailable to us.
• The pumps that send Hetchy water to San Antonio and to the Sunol Valley Water Treatment Plant were recently upgraded as part of the San Antonio Pump Station Upgrade.
• The Sunol Valley Water Treatment Plant Expansion and Treated Water Reservoir upgraded filters and outlet works at the plant, and recently finished construction of a new treatment basin.

In short, should Hetchy supplies become unavailable to us because of the Rim Fire, or need to be treated, we have completed enough infrastructure upgrades in the Sunol Valley to filter and provide 160 million gallons of water a day to our Bay Area Customers for up to 2 months.

This incident underscores the urgency to complete the remaining water system upgrades in the Valley: New Irvington Tunnel, San Antonio Backup Pipeline, and a replacement Calaveras Dam.

So, when the next large incident occurs -- we will still be ready!

For up to date information on the rim fire, please visit sfwater.org/RimFire.

San Antonio Pump Station









Water being filtered at the Sunol Valley Water Treatment Plant

Less than 1,000 feet to go!

It’s an exciting time here for the New Irvington Tunnel Project team.  As of August 14th, we have 886 feet of mining left to go!  The hole-through of the entire 18,860 ft tunnel is expected sometime this Fall 2013.  After we hole-through, construction is not quite done yet.  Miners will start preparing the tunnel for the installation of 8.5 ft diameter steel pipe, installed in 50-foot sections and welded together inside of the tunnel. We anticipate final completion of the New Irvington Tunnel at the end of 2014. Upon completion of the seismically-upgraded New Irvington Tunnel, the SFPUC will take the existing tunnel out of service for an inspection to assess the need for future maintenance and repairs.

We plan on hosting an Open House for the project on September 25, 2013.  All are invited to see our tunnel progress and project updates. Stay tuned for the invite!

For more information on the New Irvington Tunnel Project, subscribe to our blog, or call our 24 hour answer line at 866-973-1476 or email mle@sfwater.org

Tunnel workers pouring invert concrete

Vargas East Final Steel Liner looking west

Did you feel that shake?

We sure did here out in Sunol Valley at our construction sites!  A small earthquake struck on July 15, 2013 at 12:02 p.m., which measured at a 3.4 magnitude, according to the U.S. Geological Survey (USGS).

According to the USGS, the epicenter was located 7 miles east of Milpitas and 9 miles northeast of San Jose, at a depth of 5.3 miles below ground.  The earthquake was triggered by the Calaveras Fault. This active fault is located near to, or in some cases underneath, crucial water infrastructure in the Sunol Valley, including: the  existing Calaveras Dam,  the treatment plant that filters water from the valley for our customers, the pump station that transmits water to and from the plant, and the major pipelines that transmit water from the Sierra Nevada and the Alameda Watershed to our Bay Area customers.

Why does this matter?

This is a reminder to us why our work to seismically upgrade these crucial water transmission facilities through the Water System Improvement Program is so important.  We work every day to ensure that we can provide water to our customers within 24 hours after an earthquake.

·         We recently constructed a fourth seismically-designed pipeline that crosses the Calaveras Fault to survive after an earthquake

·         We completed seismic upgrades to the nearby San Antonio Pump Station

·         Upgrades to the Sunol Valley Water Treatment Plant are nearly complete.

·         Construction of the New Irvington Tunnel and a replacement Calaveras Dam are underway.

Our system is more reliable today than it was 10 years ago. And it will be much more reliable, still, 10 years from now.

We hope that the earthquake we are planning for never happens. But if it does, we will be ready!  To learn how to make yourself and your family ready, visit 72hours.org

Crews completed work on the Alameda Siphon #4 Project in 2010, which crosses directly over traces of the Calaveras Fault.

The New Irvington Tunnel will provide us a new 3.5 mile seismically upgraded tunnel.  Workers are seen here standing a set in the new tunnel and expect final tunnel hole-thru this Fall 2013 with completion at the end of 2014.

Calaveras Dam is being replaced to provide a new earth and rock fill dam restoring the historic storage capacity of the dam to 96,850 acre feet (31 billion gallons of water) and will withstand a credible earthquake from the Calaveras fault. 

 

During construction at the Sunol Valley Water Treatment Plant, crews drilled almost 1,200 piers underneath the new treated water reservoir to anchor it into the hillside in case of an earthquake on the nearby Calaveras fault.