The city planners of Roseville, California were looking forward to an economically prosperous future. Their city's population was expected to reach 103,000 by the year 2010. This repre-sents an increase of nearly 90 percent. New residents are drawn to the area by its clean air, lifestyle, and convenient location in the rolling foothills of the Sierra Nevada mountains, about 20 miles northeast of the state capital, Sacramento.

Not content to simply "let" progress happen, Roseville had initiated a master plan for putting necessary infrastructure in place to accommodate surging population growth and the changing nature of the businesses that contribute to its tax base. The city expects to spend over $100 million on water facility improvements alone from 1990 to 2010.

Its high technology firms are major water users. The city's two largest employers are Hewlett-Packard, which built its first computer products plant located outside California's Silicon Valley in 1979, and NEC Electronics which makes microchips in a 650,000 sq. ft. facility opened in 1986. Together these two companies employ more than 5,400 people. Both have plans to add more jobs and manufacturing space in Roseville.

NEC, in particular, requires extremely clean, particulate-free water for semiconductor fabrication. The company uses more than one million gallons of water a day in its chip man-ufacturing facility. Other companies are coming as well, with AT&T being the latest high technology firm to move into the area.

Planning for Growth

Roseville's water needs required that a new 66" diameter pipeline supplement the existing 42" AWWA Standard, C303 Bar Wrapped Concrete Cylinder Pipe (CCP), supplied by Ameron in 1969. Helmick & Lerner of Sacramento was retained by the City to design a system with 11,490 LF of 66" AWWA Standard, C301 Prestressed Concrete Cylinder Pipe (PCCP) to bring water from Roseville's Water Treatment Plant (WTP). Paralleling the existing line and sharing the same easement, the new pipeline will serve as a backup for the existing pipe and supply water from the WTP that was expanded from 24 to 48 MGD.

On January 31, 1994, T & S Construction Company, the successful bidder selected Ameron, to supply the specified PCCP. T & S Construction is a local family-owned and operated company that specializes in pipelaying jobs throughout the region. When the project was completed in the summer of 1995, the pipelines now have a capacity of 96 MGD. Roseville estimates peak daily water demands for 2010 will be a maximum of 62 MGD.

Prestressed Concrete Cylinder Pipe chosen for its Strength

The City's facilities engineer characterized the pipeline project as fairly straightforward, except for its proximity to the existing 42" CCP carrying the city's only water supply. Giant underground granite boulders had to be excavated and blasted without disturbing the old system, which is only 10 feet away.

Those circumstances, plus the pipeline's location just outside the city limits and travel-ing through pasture lands that were yielding to housing development, led project engineers to choose PCCP for both its rigidity and its strength. The 66-inch pipe, in standard 24-ft lengths was tested to 150 psi after the installation was completed. The pipe was bedded in crushed rock and the contractor backfilled with a minimum three-foot cover. A PCCP section after joint assembly.

The line made one creek crossing that required restoration of plant life. There were four tie-ins - one at each end of the line and two more located at approximately the halfway point. Because the tie-ins were with pipe that had already been in the ground up to 25 years, T & S Construction paid special attention to testing their integrity.

The excavation skirted a new residential neighborhood adjacent to the site where a new high school was built. To accommodate the developer of an upscale housing tract, the pipeline contractor started digging in the middle of the project. Trenching and pipelaying moved toward the city. When that phase was completed, the contractor returned to the middle point and moved toward the treatment plant.

T & S Construction's founder, the late Tom Spinella, showed his willingness to approach the project in this way, which reflected his strong sense of community, and confidence in the suitability of PCCP for the job. Tom had worked with many types of pipe since he start-ed in business 44 years ago. "Concrete pipe is tough," he said. "It's easy to join and seal, and its longer lengths make the job go quicker. Besides, those people in their new houses wouldn't want us tearing up their brand new streets if we don't have to!"

The protective characteristics of the pipe's mortar coating were another factor in the choice of PCCP. Its manufacture and design, including its standard single O-ring Carnegie joints, complied with the standards approved by the American Water Works Association (AWWA C301-92 and C304-92) for Prestressed Concrete Cylinder Pipe.

When their new PCCP pipeline was placed in service, Roseville expected to be well prepared for the demands of the next century. Roseville residents are living the old adage of the West - prosperity and a plentiful supply of water go hand-in-hand. A 24-ft pipe section being prepared for joint assembly

top