Eureka, UT — Located 70 miles south of Salt Lake City , the town of Eureka is part of Utah ‘s historic Tintic Mining District. For more than 100 years, miners took lead, silver, zinc and copper from some of the most bountiful mines in the country. This prosperity has come at a price and the area is now a superfund site. The fast paced cleanup involves the construction of a high-density polyethylene (HDPE) pipeline to carry vast amounts of water to the restoration areas for dust suppression.
The supply line for the project will consist of approximately 22,000 feet of six-inch and eight-inch HDPE and a large portion of the project will utilize HDPE classified as PE 100. PE 100 is a resin developed and heavily used in Europe that enables the pipe to operate under higher pressure with the same wall thickness.
The pipeline is a major part of the cleanup effort that was spawned after high levels of lead and arsenic were found in soil samples in and around the town of Eureka . Environmental Protection Agency (EPA) performed blood tests on residents of the city and found unacceptable levels of lead in 50 people, mainly children. The EPA immediately proposed the Eureka Mills site for its National Priorities List (NPL).
Designating the site as a national priority makes it eligible for federal funding. EPA moved quickly in responding to the human health risks at the site and began emergency cleanup of lead in residential yards one month after proposing the site for the NPL.
The State and EPA also sampled mine-waste piles surrounding the town. Lead concentrations in the mine dumps and adjacent areas were also high, ranging from 2,000 parts per million (ppm) to over 51,000 ppm.
The cleanup includes removing contaminated soil from residential yards and replacing it with clean soil and vegetation. Remediation of the mine waste areas involves re-grading to stabilize the slopes of the land and capping them with clean sub-base material and rock to prevent direct human contact. Erosion by wind and water must also be taken into account when creating a design for ground water runoff.
There is simply no other piping material that could have handled all of the demands of this system
The entire construction site presents a major challenge to the project. The dust caused by the earthwork will increase contact between the citizens of Eureka and the contaminated soil.
To control the contaminated dust, water will be pumped to the locations where the earthwork is being performed. The water will be sprayed over the landscape to prevent dirt from rising into the air.
The construction of the pipeline was a fast paced project and was only allowed a 12-day window in which to complete the entire 22,000 feet.
“The speed of construction and requirements that would be placed on the pipeline once installed, left little choice in what kind of pipe could be used,” said Golden Hatfield of Maskell-Robbins (MR).
MR supplied the HDPE, fittings, fusion equipment and technical assistance for the project to Rain for Rent who installed the pipe. “There is simply no other piping material that could have handled all of the demands of this system,” said Hatfield.
One distinctive aspect of the pipeline is that it will not be buried and will be exposed and laying on the ground. This will benefit the project in two ways. First, not having to excavate a ditch will prevent more dust from rising into the air. Also, the lack of a ditch will lower the cost of the project.
Since the pipeline will be exposed to the elements and operated year round, HDPE is well matched for this application in several ways. It is resistant to ultraviolet degradation, has the ability to flow over the contours of the land and can expand diametrically and longitudinally to prevent a rupture. If the water in the pipe freezes, the pipe will expand to relieve the stress and will not rupture. Its flexibility also decreases the echo of a water hammer and can handle surges up to double its working pressure.
Perhaps the strongest advantage of HDPE is how it is joined together. The pipe is heat fused together creating a joint that is stronger than the pipe itself. With no joints, the pipeline becomes a true monolithic structure that has no weak link. The life cycle of the system is then based on the material and not the connecting points. The only chance for leakage comes from third party damage. The pipe is being fused together with two McElroy fusion machines.
Rain for Rent chose to use two fusion machines in the same staging area so that more pipe could be fused together in the same amount of time. The process of running additional fusion equipment at the same location is called ‘piggy backing.’ The advantage is that one fusion technician can operate additional fusion equipment in the same amount of time it takes to run one. While the fusion joint is cooling on the first fusion procedure, there is time to start a second or even third fusion joint in additional machines. While the second joint is cooling, the first is ready to be moved and the process rotates accordingly.
A new piece of equipment from McElroy was also involved with the project and proved to not only save time but prevented wear and tear on the backs of the workers. The PolyPorter is designed to aid in the lifting and moving of polyethylene pipe in the field. It is a hand-operated tool used much like a dolly and is intended for pipe up to eight inches in diameter. The new tool also replaces the pipe stand.
“We moved a lot of pipe in a short amount of time,” said Hugh Lambert of Rain for Rent. “This simple little tool made it possible for two men to load and operate two fusion machines at the same time without having another worker or separate piece of equipment to load the pipe into the machine.”
To date, the cost of investigations, the feasibility study, and removal action has been approximately 10 million dollars. Building ordinances, a health education program, and on-going blood lead testing will be implemented to protect Eureka residents. Fact sheets, monthly briefings of the City Council, and informal discussions, are informing the community during the construction season. The EPA continues to monitor the site to ensure there is no immediate threat to human health or the environment pending the start of long-term cleanup work.