The Navajo Tribal Utility Authority has agreed to bring six wastewater treatment facilities into compliance with the federal and Navajo laws in...
In the rugged terrain of Wilson, Wyo., where temperatures can range from subzero to 100° F in the span of six months, managing the city’s sewer system can be challenging, to say the least.
To be successful, the engineering team at the Wilson Sewer District (WSD) carefully studies current operations as well as changes on the horizon, including the consideration of how vacant land will be developed for short-term and long-term planning.
WSD is responsible for overseeing the sewer and water needs of the local residents, and it is this team of engineers who are responsible for keeping things flowing in the right direction.
Teton Pass, near Wilson, Wyo., is an example of the area’s rugged terrain.
A Package Deal
With the assistance of Nelson Engineering and Water Works Industries, Inc., the area waste management distributor that serves and consults with the WSD regarding strategic design, WSD erected five lift stations, spanning thirteen miles of pipeline, to service the area.
Gorman-Rupp lift stations were selected for the project based on their reputation for excellence and their ability to set large 6-, 8- and 10-ft-diameter wet wells with completely integrated, packaged lift stations. In addition to these stations, two more lift stations were also installed in the heart of Wyoming’s ski district, Teton Village.
Another lift station is being planned to accommodate the area’s unprecedented growth—all of which are pumping into the same force main. From there, waste is pumped to a larger lift station, which moves the waste across the Snake River, encompassing yet another 13,000 ft of force main.
When deciding on an effective waste management strategy, selecting pumps that could withstand constant use and harsh weather conditions was of the utmost importance. Gorman-Rupp JSV-Series-equipped lift stations were selected for their durability, as the pumps are constructed of cast iron and engineered to last.
“We’re using these lift stations to pump sewage and wastewater to our central systems,” said Jon Wagner, an operator with WSD. “To serve a community as diverse as ours requires a lot of additional equipment …and a lot of safety issues.”
The climate and elevation also had a significant influence on equipment decisions. In the planning stages of the operation, the team knew they weren't dealing with a standard platform and a typical waste management challenge.
Specifically, as high groundwaters plaque the area, a pumping solution that was easy to install—and easy to maintain—became imperative. In the end, installation of the lift station was complete in just a half-day’s time. “We pulled them off the truck, set them and we were done,” said Wagner. “The reliability of this technology just speaks for itself. The entire lift station is a very reliable piece of equipment. They take very little maintenance.”
Double the Power, Double the Confidence
Even though a single submersible pump could do the job, WSD employs a duplex pump system to prevent unnecessary emergencies and to assist in effective planning for the continued flow of the system. Per the plan, each pump is strategically alternated. In doing so, the authority has the ability to pull a pump that goes down without disrupting the overall service of the area while the necessary repairs are being made.
The district can also run on “lead and lag” option with the pump stations—an effective and beneficial strategy for situations similar to Wilson’s where the amount and level of the wastewater can often become unpredictable. But even with two pumps running concurrently, depending on the amount of water to be pumped, the volume of water may become unmanageable. In these cases, the pump station automatically shifts to an alarm mode, notifying the operator that the standby pump is operating. The operator can easily adjust the on/off-alarm settings.
Additionally, the 12V DC level controls and a standby generator that drive the pump in the event of a power failure further enhance the auto-start feature. When power is restored, the electric motor operation resumes automatically. WSD particularly likes the idea of “a single source of responsibility” for all the parts of the station. Gorman-Rupp lift stations encompass a total, single source pumping solution, including not only pumps, but electronics, controls and pressure switches to keep the city of Wilson up and running.