Utah’s Washington County, also known as “Dixie”, has become a haven for retirees and recreational sports fanatics. Who could blame them? The beautiful red sandstone landscape, easy drive to Las Vegas, and moderate winter temperatures all work together to make the region one of the United States’ fastest growing communities.

However, extra population equates to more demand on water in an area that receives little to no snowfall and very little precipitation. With such a premium on water, the Washington County Water Conservancy District has turned to high-density polyethylene pipe, for its leak-free characteristics, durability, strength, flexibility and easy installation.

“We have been nothing but successful with HDPE pipe,” said Chuck Carney, operations manager for the Washington County Water Conversation District. “We’ve been using it since 1986 and we’ve got it in all sizes from 1 inch to 63 inches.”



Recently, a new 1,400-foot, 63-inch IPS SDR 17 pipeline installation was required to get more water to a treatment plant that provides St. George and the suburban areas of Washington, Ivins, Hurricane, and Santa Clara with water services. The large sticks of PolyPipe were provided by High Country Fusion, while the MegaMc® 1600 four-jaw fusion machine used in joining the pipe was provided by ISCO Industries.

To understand how the Washington County Water Conservancy District would benefit from the new secondary water line, one must understand their water situation.

Two reservoirs provide the water to sustain life in Washington County – Quail Creek Reservoir and Sand Hollow Reservoir. The two bodies of water are separated by the Virgin River, requiring any pipelining created between the two reservoirs to be located under the river bottom. Before construction began on the 63-inch line, a steel pipeline ran from Sand Hollow to a hydroelectric plant. From the plant, another water line ran into Quail Lake with a by-pass line tied in just before the pipes entrance to Quail Lake. That by-pass line supplies water to the water treatment plant that makes it suitable to the public.



“We chose HDPE because we had to go under the river. We have a 54-inch steel line that forces us to sleep with one eye open,” said Carney. “We wanted to put HDPE in and not worry about a leak or corrosion.”

The goal of the new HDPE line is to get the water from Sand Hollow directly to the water treatment plant without taking a longer route to the hydro plant and then to Quail Lake. This circumvention of the line allows the water district to perform both actions (running water from the hydro plant to Quail Lake and running water from Sand Hollow to the water treatment plant) at the same time. The ability to get increased water resources to the water treatment plant is critical as the 40 million gallons-a-day plant looks to double output over the coming years.

The McElroy MegaMc® 1600 four-jaw was on site to perform the fusions for the pipeline. With such heavy pipe, the 30,000 pounds of clamping force per jaw and 88,000 pounds of available fusion force came in useful in maneuvering the pipe into place for butt fusion. Without the power of the four-jaw machine, it is unforeseen whether the pipe could have been fused together with any other machine. The drag forces and nature of the pipe required McElroy’s largest fusion machine to perform the operations.

The installation of the pipe required contractor Interstate Rock to divert the Virgin River in order to lay the pipe underneath the bed. After laying the pipe, the river was allowed to flow along its natural boundaries once more. The entire length of pipe was installed with open trench methods. Washington County’s Water Conservancy District is no stranger the HDPE. Other previous HDPE experience includes a 12 mile 52 inch and 63 inch pipeline for irrigation and a 12-mile 36-inch line for gathering snow melt.

Carney advises municipalities that there is some trade off when you use HDPE. He believes the confusion between inner and outer diameters of HDPE compared to other materials frustrated municipalities that don’t fully understand all the benefits.

“A lot of communities don’t want to spend more to upsize to get the same size inner diameter they would with PVC or ductile iron. I tell them, ‘when you’re up at midnight digging that up and fixing it, I’m at home sleeping easy.”

Sincerely,

Tyler Henning

P.S. – Do you have an interesting job site that you would like to share? McElroy is always looking for fusion job sites where HDPE is being used and fused to solve an infrastructure problem. Contact Tyler Henning, public relations specialist at (918) 831-9286 or by email at thenning@mcelroy.com