A Victory for Potable Water

Potable Water

When the final decision was made to build a new potable water pipeline in this part of Utah, just southeast of Salt Lake City, the engineering firm of Jones & DeMille Engineering, Inc. (St. George, Utah) knew that it was faced with some unusual circumstances. The terrain ranged from foothills to desert to rivers and canals; plus, the pipe would also be installed under roads. Physically, the pipe would have to handle pressures up to 260 psi, be able to stand up to the corrosive soil, require minimal maintenance and be leak-free. It also had to provide the owner with a reliable and durable water distribution and transmission system.

Jones & DeMille designed the Victory Pipeline so that communities could take advantage of the Starvation Treatment Plant?s ability to process 8 million gallons of water a day. The plant?s capacity was recently doubled to meet demand for the county?s population and economic growth, which is based mainly on livestock, but it is also an area rich in oil and natural gas.

The new pipeline is being constructed in two phases and will bring water from the Starvation Reservoir in Duchesne County, Utah to serve a number of water districts and municipalities.?

?The need of the project was based on recent demand in the area,? explained Ted Mickelsen, senior project manager of Jones & DeMille. ?This county is probably the largest energy producing county in the state of Utah when it comes to oil production. There are hundreds and hundreds of oil wells in this area. The oil industry out there uses a good chunk of water especially during those times when oil demands are high. It was getting to the point that a number of agencies that supply water to these oil fields were really struggling to keep up with demand. Plus, these systems were built in kind of a piecemeal basis over the years, and the capacity of their systems was just really undersized ? they ran 8-in. pipes wherever they needed water and didn?t have one main reliable system out there. Victory is actually going to become the backbone system water system for the community.? The full system is scheduled to be completed and operational by the fall of 2016.

The Duchesne County Water Conservancy District, the owner of the Victory Pipeline, is a water wholesaler that supplies water to cities and other water agencies which in turn provide the water to the homes and businesses. The Victory project was designed and funded in 2013, and will take water from the Starvation Treatment Plant across 27.5 miles of the county and convey it to seven different water agencies, serving approximately 85 percent of the county. To build this system, pipe was, and will continue to be, installed using cut and cover, jack and bore plus horizontal directional drilling (HDD).? While developing the plan, Jones & DeMille considered all types of pipe.?

?In the course of designing the project, we had a geotechnical report completed that essentially said we had anywhere from mildly corrosive to highly corrosive soils in the pipeline path, which told us we would hit every type of soil you can,? Mickelsen said.

?We looked at the different pipe alternatives. Steel, ductile iron, PVC and high-density polyethylene ? HDPE ? were the four we looked at. Steel pipe and ductile were really not conducive to be in the soil without cathodic protection, and that would have added another layer of maintenance that the owner didn?t want to have to deal with. So that led us to looking at the plastic pipes HDPE and PVC. Because of the ground we were installing in ? open country, foothill areas, undulating ground, up and down hills ? the fused pipe became very attractive just because of production. Plus, the fused joints would give the owner another level of protection in operation and maintenance because there?s zero-leakage; that?s different than when you use bell and spigot pipelines. The key for the Duchesne County Water Conservancy District was to make the pipeline as maintenance-friendly as we could with a long projected life.

A Victory for Potable Water?The district general manager, Scott Wilson, was really interested in a fused pipeline,? he continued, ?it came down to HDPE or PVC and price wasn?t really an issue between those two options. There?s just more of a track record with HDPE having fused joints with established performance; and that ultimately determined our final selection of HDPE pipe.?

The gravity-fed water project includes installation of 27.5 miles of PE4710 HDPE pipe from WL Plastics, Inc. (Fort Worth, Texas) in diameters from 12 to 42 in. with DR?s ranging from 7 to 32.5.

?In addition to specifying the HDPE pipe, we also requested PE4710 be used,? stated Mickelsen. ?We understand PE4710 is the most advanced PE pipe material formulation, and with the pressure fluctuations we have in this project, we need good quality pipe. We didn?t allow any options.?

?This project, with its stringent requirements, identified HDPE PE4710 pipe as the best solution for multiple reasons,? explained Camille Rubeiz, P.E., director of engineering for the Plastics Pipe Institute (PPI), the major trade association representing all segments of the plastic pipe industry.?

?Several different pipe materials were considered, but all the factors and variables in this case clearly pointed to HDPE PE4710 being the right choice that could meet all the owner?s requirements. In particular, the zero-leakage capability of the pipeline was extremely important, because conserving water in this drought stricken region is imperative. The ability to fuse together long pipe strings, which can be installed in trench as well as trenchless methods, further confirmed HDPE PE4710 pipe as the optimum material to use because of the versatility of the product which can be installed in these various applications,? he continued. ?Using HDPE PE4710 pipe eliminated the need for costly fittings, and cut down on installation time because narrower trench widths than those required for other pipe materials could be utilized.?

According to PPI, the recently updated American Water Works Association?s (AWWA) C906-15 specification was modified to include the enhanced performance of HDPE PE4710 resin.

Ted Michelsen?The demands for installation of new pipelines, and revitalization of the deteriorating water pipe infrastructure are urgent and critical,? stated Tony Radoszewski, president of PPI.

?Federal and industry sources estimate that approximately 2.5 billion gallons of drinking water are lost every day because of dilapidated pipes. HDPE PE4710 pipes provide a premier alternative that eliminates any need to consider ?allowable leak rate,? conserves water and prevents raw sewage from entering into waterways or watersheds. We project that this fully-fused Victory pipeline system will deliver 30 percent more water because there will be no loss through leaking couplings, evaporation or seepage.??

The pipe was supplied by ISCO Industries, Inc. (Louisville, Ky.). The company also provided the fusion equipment and crews. On Phase I, there were two fusing crews utilizing McElroy units and installing 1,000 to 2,000 ft a day. For trenches, the excavated native soil was screened and reused for bedding. ISCO, McElroy and WL Plastics are member companies of PPI.

?The owner said he doesn?t have the time to look at the pipe and make sure there are no leaks,? Mickelsen stated. ?He wanted a pipe he was comfortable with that could meet all the challenges and would provide reliable, proven performance. And we?ll continue to use it on Phase II, where we?ll also be employing just about every technology you can use for pipe installation.?

For additional information, please go to the Plastics Pipe Institute?s website, www.plasticpipe.org.

Steve Cooper has reported on a variety of water, conduit and gas pipeline projects for several decades. Based in New York, he has travelled extensively to conduct on-site news interviews with professional engineers, contractors, government officials and representatives of major companies supplying the industry.

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