Friday, May 31, 2013

What on Earth is That?

Anyone notice the arrival of a large, red machine at the San Antonio Backup Pipeline work site this week along Calaveras road (south of I-680)? 


It is actually an excavator with a 100-foot long digging arm. Why, you might ask, would we need a 100-foot long digging arm to build a pipeline?

Good question! It will be used by one of the subcontractors on this project, Magnus Pacific/Inquip, a Joint Venture, to construct the cement slurry wall around an unused quarry pit in the Valley. When the project is complete, the pit will temporarily store occasional discharges from the Hetch Hetchy Regional Water System. To that end, we need to construct a deep cutoff wall to prevent groundwater from seeping into the pit in the future.

The large excavator will dig a deep trench while the contractor fills the trench with cement slurry. The slurry will keep the trench from collapsing, and it will harden over time to create the barrier that will keep groundwater out. The trench is deep, the ground is wet, and the work is difficult - perfect for the new machine out there.

Once complete in 2015, the San Antonio Backup Pipeline will add operational flexibility to the water system that currently serves 2.6 million customers.

See you around the Sunol Valley!

Wednesday, May 22, 2013

Do you know your Tap Water? Series #1

It’s likely that few of our 2.6 million Bay Area customers think about how we make sure that high quality water reaches their taps each day. We’d like to change that…. In a series we’re calling, ‘Do you Know Your Tap Water’?



#1 Hetch Hetchy


 
More than 85% of the water we provide to you, our customers, comes from Hetch Hetchy Reservoir. It has to travel the width of the State of California in order to reach your taps. Here are a few facts about the system that serves you that you may not know.
 

      Hetch Hetchy Reservoir



  •  The Hetch Hetchy Regional Water System was constructed in the 1920’s and 1930’s.



    • The Mitchell Shaft Crew pauses for a photo in 1934.






    • As water tumbles out of the Sierra Nevada Mountains, it generates hydropower to power services in the City of San Francisco, such as S.F. International Airport, MUNI and City Buildings. 

    • Water moving downhill rotates 8 individual  turbines to generate hydropwer, such as the one pictured here in 1927.





    • This water travels all the way to the Bay Area using only the power of gravity.

      • The source of this water is so outstanding – melted glaciers sitting on a granite basin – that we that we do not have to filter water from Hetch Hetchy Reservoir.



      • Did you know that the SFPUC worked out of a Livermore office during construction of the Hetch Hetchy Regional Water System?

         


        Wednesday, May 15, 2013

        Calaveras Dam Completes Major Work on New Intake Structure

        Our contractor recently completed the final concrete pour for the new intake structure, which is a key component of the Calaveras Dam Replacement Project.  This tower is the connection point for the water pipelines that draw water from the reservoir, before it is treated at the Sunol Valley Water Treatment Plant and then sent on to our 2.6 million customers.

        The contractor used 1,400 yards of concrete to build the new intake structure.  That is the equivalent to the weight of more than 12 cable cars!  At 214 feet tall, the structure is almost as tall as the height of the new Calaveras Dam (220-feet-tall). It took our crews more than 29,000 hours to construct the tower.

        Crews still need to finish the exterior work on the structure, which will replicate the architectural style of the original tower that was built in 1925. The final external touches are expected to be finished in a few years’ time. 

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


        Original Intake Structure built in 1925

        New Intake Structure in progress today

        The Calaveras Dam team gathered to celebrate this milestone at the site

        Thursday, May 9, 2013

        What are We Building along Calaveras Road?

        Those who frequently travel on Calaveras Road in the Sunol Valley will likely notice increased activity along the west side of Calaveras Road, south of Interstate 680 (I-680). It is, in fact, the latest Water System Improvement Program Project to begin construction in the Sunol Valley - the San Antonio Backup Pipeline Project. Construction officially began in April, and the contractor, Ranger Pipelines Inc., has begun mobilization activities.

        What are we building?
        • Approximately 1.3 miles of 5 ½ foot diameter pipeline
        • New chemical storage, feed, and equipment facilities
        • A new cut-off wall around one of the quarry pits located just south of I-680.
        • The contractor will also complete upgrades to the water delivery pipeline that serves the Town of Sunol.
        What to Expect
        • Trucks entering and exiting the project driveway site, along Calaveras Road approximately 1/3 of a mile south of I-680 along Calaveras Road.
        • Intermittent delays are possible during construction on Calaveras Road.
        • Please proceed with caution when travelling through construction zones.
        • Additional construction activity on the west side of Calaveras Road.
        • All construction activities will occur on SFPUC-owned property.

        Project Location Map
        Alignment for San Antonio Backup Pipeline is in red.
        Work Hours
        • Monday – Friday: 7:00 a.m. to 5:00 p.m.
        • No planned work on weekends or holidays.
        Why are we building this?
        Two-way traffic is better, at least in the case of the San Francisco Public Utilities Commission’s (SFPUC) San Antonio Pipeline. The existing San Antonio Pipeline acts as a water transmission pathway in the Sunol Valley. This pipeline allows us to discharge Hetch Hetchy water to San Antonio Reservoir for storage and send reservoir water to the Sunol Valley Water Treatment Plant for treatment before distribution to customers. The problem is that there is currently only one pipeline, so water can only move in one direction at a time.

        When complete in 2015, the San Antonio Backup Pipeline will enable the SFPUC to discharge Hetch Hetchy water to a nearby quarry pit during emergency events while at the same transporting San Antonio Reservoir Water to the Treatment Plant at the same time. This adds operational flexibility to the system and minimizes the risk of service disruption to 2.6 million customers.

        See you around the Sunol Valley!

        Wednesday, May 1, 2013

        Construction Work Starts This Week for Bridge Replacement Project inside Sunol Ohlone Regional Wilderness Park


        What:
        The SFPUC is constructing a new bridge to replace the existing unreliable Geary Road Bridge with a new concrete and steel bridge. The new bridge will protect Alameda Creek at this location by eliminating the need for vehicles to drive through Alameda Creek at the low-water crossing. The area will be restored after construction.

        Where:
        The project area is located inside the Sunol Ohlone Regional Wilderness Park, just south of Leyden Flats before it connects to McCorkle Trail and Camp Ohlone Road, where it crosses Alameda Creek. (See map below).

        When: May 1, 2013 through December 31, 2013

        What to Expect:
        • The area will be closed to the public during construction, Monday through Friday, for safety reasons.
        • Park users should use the Canyon View Trail footbridge to cross Alameda Creek. Please pay attention to posted trail closure signs!
        • The area will be open to park users on Saturdays, Sundays and holidays. Please proceed with caution.

        Work hours:
        • Monday – Friday, 7:00 a.m. to 5:00 p.m.
        • No work on weekends or holidays

        For additional questions or concerns, call our 24 hour toll-free line at (866) 973-1476 or visit www.sfwater.org/sunolvalley.