Friday, January 24, 2014

A Day in a Life of a Driller

A crucial job that is integral to the design and construction of the Calaveras Dam Replacement Project might surprise some: the driller. During the design phase of the project we drilled more than 11,000 linear feet of core samples to characterize the subsurface ground conditions in and around the location of the replacement dam.

And we didn’t stop there. We are still drilling on the project to clarify the geologic conditions specifically on the left abutment (or adjoining wall) of the future new dam. Skill is key in exploratory drilling. We are lucky to have incredible personnel on site. We’d like to introduce you to one now - one of our lead drillers - Bay Area resident Will Halai.  He has been performing this type of work on construction projects for more than six years.

Will immigrated to the United States in 1992 from Tonga, a country in the South Pacific, to make a better life here for his family.  He works daily with his assistant Fine Taufatofua, also of Tongan descent, who has been drilling for the last four years of his career.  Both are members of the Operating Engineers Local 3, the union which represents heavy equipment operators and construction workers.

Typically, each drill advances a bore hole 40 to 60 feet per day.  The 4-inch diameter drill holes average about 100 feet in depth, while the rock core they extract is 2.5 inches in diameter.  After the borings are drilled, many are logged with a televiewer, which provides a continuous image of the inside of the borehole to allow the identification (and orientation) of important geologic features.  On average, five to six core borings are completed per week.  All of this information helps to ensure that the new Calaveras Dam, when built, will sustain a maximum credible earthquake on the nearby Calaveras Fault.

Will works with Bill Henrich of Norcal Geophysical during televiewer logging,
which is used to obtain important data from the core boring

Union Local 3 Operating Engineers Will Halai & Fine Taufatofua
from drilling work at Calaveras Dam 

Tuesday, January 14, 2014

What’s on Tap for the Sunol Valley in 2014?

A few weeks into the New Year, our Sunol Valley Project teams are already very busy with the important work to seismically upgrade facilities which deliver drinking water to 2.6 million Bay Area customers as part of the Water System Improvement Program (WSIP) and other ongoing projects. Here’s a quick snapshot of the anticipated activities of the year to come. Please visit us often on our blog to stay up to date and learn more!

New Irvington Tunnel
In October 2013, we completed excavation of the new tunnel.  Recently, the project team began installing the inner lining for the tunnel. These are 50-foot-long, 8½ foot in diameter steel pipes that are inserted into the tunnel on a special train. Once in place, these pipe segments are welded together from the inside.  On average, seven pipe sections are installed daily.  Project completion is anticipated for 2015.

50 ft. pipe being prepared for installation at New Irvington Tunnel

Calaveras Dam Replacement Project
The largest project in the Sunol Valley continues with ongoing major excavation as well as drill and blast activities to stockpile materials in preparation for the construction of the replacement dam.  We are still clearing out loose soil and rock materials in the area to make room for the new dam. In the coming weeks, the project will begin construction of the new 1,550-foot-longspillway, all the while dealing with the continuing challenges of the site’s complex geology. Grouting work on the left abutment of the new dam will also begin soon.  As construction progresses, the environmental team continues to find and catalogue interesting fossils at the site. Projected completion is anticipated in 2017.
Aerial view of upper Left Abutment for Replacement Dam
(left side of valley when looking downstream)

San Antonio Backup Pipeline
Construction of the San Antonio Backup Pipeline, which will add operational flexibility to our Sunol Valley Water transmission system, has been moving forward towards completion in March of 2015.  The majority of the new pipeline has been installed and is in the ground.  The new slurry wall was also completed last year.  This year the project team will focus on construction of the small above-ground structures and discharge pumps at the quarry storage pond at the north end of the site.

Workers excavating and shaping the hillside in preparation
for the outfall structure that will be going into Pond F3-east

Town of Sunol Fire Suppression System Project
2014 will see the start of construction of this important public safety project in the Town of Sunol.  The SFPUC will upgrade the water distribution system for the Town of Sunol since the current system is inadequate.  The SFPUC will add additional fire hydrants in commercial and residential areas of the Town of Sunol, replace pipelines on County roads to improve the flows from the fire hydrants, and also replace two to four of the Town's existing water storage tanks on the hill.  Construction for this project is anticipated to start spring/summer of this year.

Alameda Creek Watershed Center and Sunol Yard Upgrade
Plans are underway to design and construct the Alameda Creek Watershed Center located near the Sunol Water Temple, as part of its efforts to improve the existing facilities in the Sunol Yard. The proposed Watershed Center would provide a place for people to gather and learn about the Alameda Creek Watershed, its natural resources and its role as part of the SFPUC water supply system as well as connect with the history of the Sunol Valley.  This project is in its early planning and design stages with construction anticipated to begin in 2015. 

Bioregional Habitat Restoration
Construction activities for the Bioregional Habitat Restoration (BHR) program will start winding down this year. We will, however, continue to monitor the success of these projects through 2024. The projects that are nearly completed within the Sunol Valley  -- Goldfish Pond Restoration at the southern end of Calaveras Road, San Antonio Creek Restoration, Sheep Camp Creek and Goat Rock – have restored or enhanced a combined total greater than 1,500 acres of sycamore and oak riparian woodland, oak woodland and savannah, and serpentine and annual grasslands.

This project includes restoring 5,000 feet of the existing Sheep Camp Creek.

Completed Projects
As we start 2014, we can also continue to celebrate the completion of the Sunol Valley Water Treatment Plant Expansion and Treated Water Reservoir project in September 2013. This water treatment plant now enables us to filter and provide 160 million gallons of water per day to our Bay Area customers for up to two months should our Hetch Hetchy Reservoir supplies become unavailable due to an earthquake or other emergency.

We look forward to working with you this year and all the good things to come to Sunol Valley!