Universal Pump Station Receives Major Upgrades
Equipment and technology upgrades at the station were aimed at increasing efficiency while reinforcing the reliability of this critical piece of storm water management infrastructure in Saginaw County
City of Zilwaukee – Originally constructed in 1968 to help reduce flooding along the Universal Drain, the Universal Pump Station has done an excellent job of minimizing flood damage to the surrounding communities of Saginaw Charter Township, Carrollton Township, and the City of Zilwaukee.
The station was constructed at the downstream end of the Universal Drain where it outlets into the Saginaw River. The drain provides drainage to 4,148 acres of heavily populated land with a relatively flat topography that tends to make the drain very flashy during heavy storm water runoff events.
“The original station was constructed with three axial-flow pumps with 150hp motors and rated for 30,000 gallons per minute each,” Spicer Group Project Manager Nick Czerwinski, P.E. said. “Later upgrades included the addition of two more pumps, a self-cleaning trash rack to replace the bar screen, reconfiguration of pumps, outlets, and the addition of a gravity outlet that could pass water during periods of low water in the Saginaw River.”
In an effort to upgrade the station’s reliability, Saginaw County Public Works Commissioner Brian Wendling hired Spicer Group to complete an engineering study that took a close look at the station’s components including the power source, pumps, trash rack, controls/sluice gate, monitoring capabilities, site lighting and safety, and general facility conditions. Spicer Group identified many areas that were in need of replacement, upgrades, and improvements.
“We wanted to take a good look at this station since it’s such a key asset in the county’s storm water management infrastructure,” Wendling said. “Any type of failure at the station could pose a serious flood risk to local residents and businesses during times of heavy runoff.”
All improvements identified in the study were deemed necessary and Spicer Group put together a design that significantly upgraded the station to a state that allows Wendling and his crews to manage the County’s storm water infrastructure more efficiently.
“Any type of failure at the station could pose a serious flood risk to local residents and businesses during times of heavy runoff.”
“The Saginaw County Public Works Commissioner is responsible for maintaining all county drains in Saginaw County, which is a complex task considering the high number of drains, relatively flat topography of surrounding lands, and the fact that Saginaw County lies along the downstream end of one of Michigan’s largest watersheds,” Czerwinski said. “This role is also further complicated by the current high levels of the Great Lakes and connecting waterways such as the Saginaw River.”
Czerwinski explained that flows from the Universal Drain first enter a massive mechanized self-cleaning trash rack complete with large steel sheet pile and concrete wing walls and a debris collection area. The team incorporated new radar water-level sensors both upstream and downstream of the trash rack to measure the headloss through the rack. If it is above the threshold in the control system, indicating the trash rack is full of debris, the control system automatically signals the trash rack to cycle and remove the debris, therefore allowing storm water to flow to the pumps.
Exterior of pump station featuring complete building refurbishment and enhanced safety features.
Prior to this upgrade to the pump station, operators had to physically be on-site and keep an eye on the build-up of debris and water levels and then turn on the trash rack to cycle the debris out. Prior to that, they had to manually remove the debris from the original bar screen that was once in place.
New Duperon® self-cleaning trash rack being installed.
New trash rack.
“The new trash rack is fully automated, and all equipment can be viewed from a mobile device or computer at any time, including water levels, number of cycles of the trash rack, and the amount of debris piling up in the receptacle area,” Czerwinski said.
After flowing through the trash rack, storm water either passes through a sluice gate and then discharges to the Saginaw River, or it is diverted to the Universal Pump Station wet well. The deciding factor of which way the storm water is directed is determined by a radar sensor at the pump station discharge into the Saginaw River and a radar sensor at the sluice gate. If water levels at the Saginaw River are higher than the level at the sluice gate, that signals the gate to automatically close, which then diverts flows to the pump station wet well. If water levels at the Saginaw River are lower or equal to the level at the sluice gate, then it remains open, and flows exit to the Saginaw River via gravity.
This process is now fully automated and allows Mr. Wendling to monitor this operation from a mobile device or computer. Originally, crews had to physically monitor the levels and manually open or close the gate despite the weather or time of day.
If flows are diverted to the pump station, three new 200-hp and two 100-hp pumps—all 36” diameter axial flow pumps—have the combined capacity to pump 121,600 gallons per minute through the building and out into the Saginaw River. These pumps were optimized with VFDs to minimize start/stop cycles and significantly increase the efficiency and lifespan of the equipment.
“Unlike the old pumps that simply turned on at full speed or off despite what the flows were, the new pumps power up one-by-one and vary their speed based on the rate of flow,” Czerwinski said. “Like the trash rack and sluice gate, all mechanicals in the pump station including the pumps, water levels, and flows can be monitored on a mobile device or computer.”
Czerwinski said that when tasked with developing solutions for the Universal Pump Station, Spicer Group could have easily incorporated a baseline design that would have maintained the original rate of efficiency of the old pump station and equipment, but instead enhanced that effort by proposing to include the advanced technologies of SCADA-based automation and digital monitoring capabilities.
“We also made sure Brian could remotely monitor the fuel levels of the new generators that were installed, therefore depending on the amount of expected time power may be out, he can schedule fuel trucks in advance to keep the generators running,” Czerwinski said. “The generators are a duplex generator system that can power the entire station with both generators running and provide a redundant backup power system to guarantee at least three pumps can run at all times.”
New main control panel featuring Kennedy KISM SCADA system and new security system.
Additional unique features that were incorporated into the design included security camera systems that can be used to visually observe conditions at the site and a weather station that was integrated into the control system. The weather station can help monitor how levels in the pump station react during rain events, which can then be used to help predict measures needed in reacting to a storm larger than the pump station is designed for, or during a rain event during scheduled maintenance or repairs in the future.
“I am excited to have this project complete. The design allows me to now monitor the pump station and all key assets and equipment remotely, assign crews when necessary, and focus on county-wide issues when we are impacted by large runoff and storm events,” Wendling said. “The pump station and trash rack performed flawlessly during the major flood event our region experienced in May 2020 when we were hit with several inches of rain and several dams broke upstream. I was able to keep a close eye on other flood-prone areas of the County while remotely monitoring the Universal Pump Station.”
The riverbank was stabilized on the discharge side of the pump station to minimize erosion.