The Rewards of Renting
Large sewer bypass projects can challenge municipality resources. Renting pumps can lead to cost savings and leading edge solutions.
By Hunter Powell
It’s not every day that cities and municipalities need to undertake large-scale bypass projects within their district. But when they do - whether it’s to address repairs or renovations - it’s critical to assess and identify the challenges early on in the planning stages of the project. And equally critical, as the city of Raleigh found out with a recent project, is to bring in the experts that specialize in this type of work when it comes time to get the job done. Whether it’s an engineering firm, a contractor, or an equipment manufacturer, all can play a part in the execution of a successful project.
BRING IN THE EXPERTS
The city of Raleigh, N.C., needed to replace a major 42-inch outfall line that feeds one of the city’s three wastewater treatment plants. To oversee the work on the facility, the city brought in Park Construction Corp of North Carolina, a local company recognized as one of the leading contractors for waterlines, bypass pumping, and sanitary sewer main projects.
|In order to maintain treatment operations while the outfall was replaced, Park Construction needed to set up a temporary sewer bypass system.|
In order to maintain treatment operations while the outfall was replaced, Park Construction needed to set up a temporary sewer bypass system. The project included 1,800 feet of 18-inch HDPE discharge pipe and a short, 12-inch HDPE discharge line into an 18-inch manifold. On any given day, the flow in the outfall line ranged from less than 1,000 gallons per minute (GPM) to more than 5,300 GPM. Circumventing the line and handling this broad range of flow would require specific pump technology that neither Park Construction nor the city of Raleigh had on hand.
As is often the case for specific construction projects that call for a temporary solution, it didn’t make sense to purchase the necessary pumps for the short term. So Ken Malonson, vice president at Park Construction, contacted a local pump rental provider that recommended two different pumps to address the needs of the bypass project. Unfortunately for Park and the city of Raleigh, the rental company’s North Carolina division closed before the job could be completed. This caused some short-term panic for the project team, but then Malonson turned to Xylem and their pump rental and sales branch in downtown Raleigh.
EXPERTS BRINGING IN EXPERTS
When Malonson contacted Xylem to discuss the project challenges with the flow and the urgency, Xylem engineers were able to assess the bypass project and recommend the ideal solution for the job. Park Construction ended up renting one of Godwin’s Dri-Prime NC350 pumps. The NC350 is a powerful yet portable high-efficiency pump with flow capabilities to 6,530 GPM, which is ideal for sewage, fibrous material, and general dewatering applications. The 16-inch pump was available immediately and became the primary pump of the bypass system, which handled the project’s incredibly varied flow. The sewer bypass project took one month, and the NC350 ran nearly 24/7 while installed onsite. With its wide range of flows, the NC350 was able to handle low flows at night as well as higher flows during the day by increasing and decreasing speed. “Xylem was right there for us,” Malonson said. “They took over the job and replaced the pumps. We never missed a beat.”
SAVING TIME AND MONEY
The rental of the Godwin Dri-Prime NC350 pump turned out to be an ideal solution for Park Construction and the city of Raleigh. What they didn’t expect were the cost savings achieved by using the Godwin pump.
|The city of Raleigh, N.C., undertook a major project to replace a 42-inch outfall line that feeds one of the city’s three wastewater treatment plants.|
The NC350 features Flygt N-technology - a self-cleaning impeller that prevents the pump from becoming clogged by stringy solids. A relief groove in the wearplate allows stringy material to pass through the pump. The Dri-Prime NC350 outperformed the two pumps initially rented for the bypass, Malonson said. There was no need to break down the pump and clean out anything that got stuck in it because the NC350 never had to be back-flushed or cleaned - saving Park Construction time, manpower, and money.
Traditionally, a large bypass project also requires people to monitor the process and the pump system to ensure effective operation and that everything is running smoothly. The NC350 that Park Construction rented from Xylem also came with Godwin’s Field Smart Technology (FST), which provided remote monitoring and control of the pump from any device (computer, tablet, or smartphone) from any location with an Internet connection. A level transducer in conjunction with FST also enabled control of pump engine speed, including stopping and starting. Instead of paying someone to stand watch over the pump system, Park Construction personnel were able to set parameters and alarms for minor issues, which helped to address any potential problems before they caused a major shutdown, optimizing manpower throughout the project.
|Park Construction rented a powerful yet portable Godwin Dri-Prime NC350 pump. With flow capabilities to 6,530 GPM, the pump is ideal for sewage, fibrous material, and general dewatering applications.|
RENTING VERSUS OWNING
In addition to the cost savings provided by the impeller technology and the remote monitoring, some of the most significant savings to the city of Raleigh were realized by renting the pump technology equipment versus the capital expense of having to buy it outright. “A bypass of this size is not something that you do every day,” said Dave Donahue, North Carolina branch manager for Xylem. “For larger projects, end users don’t have justification for the cost of the pumps. It’s a lot smarter to rent the pump and turn it back in when the project is completed.” Xylem’s rental options provided the contractor flexibility with a wide fleet of pumps to choose from, and Malonson was able to reap the benefits of Xylem’s expertise. “They’re very professional, and they know their pumps,” Malonson said. “It’s a joy to work with them.”
About the Author: Hunter Powell is the senior applications engineer for the Southeast region for Xylem Dewatering. He can be reached at firstname.lastname@example.org.