The Southern Iowa Rural Water Association (SIRWA) provides quality drinking water to the residents of southwest Iowa. Included in its 4,000 miles of pipeline is a 16-mile, 12-inch line that runs from the cities of Creston to Corning. A pump station maintains pressure in that line. A second pump station is used to pump water through a 16-inch line to counties south of Creston.
Flooding was an ongoing issue at the second pump station, but when a severe storm shut down both pump stations, local authorities scrambled to move water to customers in Creston and Corning, bringing the issue to a head.
Following this event, SIRWA began exploring options to minimize the impact of another flooding event and ensure it was better prepared for emergencies into the future. Implementing permanent and redundant backup pump systems at each of their 40-plus stations would prove too costly for SIRWA to install and maintain. Instead, a more economical, yet robust and reliable solution was required. To address this issue, SIRWA engaged a pump distributor to develop a reliable and cost-effective solution that would support the entire water network in the event of flooding.
Identifying the Right Backup Pumping Solution
SIRWA began by identifying the specific pumping requirements necessary to support all the pumping stations across their network in instances of severe flooding. The pumps needed to be portable, allowing SIRWA to deploy the back-up systems to any station within the network any time.
The solution also needed to facilitate a flow rate of 900 gallons per minute (gpm) with 240 feet of total dynamic head (TDH). The portable pumps would need to be equipped to run dry and include a self-contained power source.
Image 1. One of the two final customized trailers and pump sets delivered to SIRWA (Images courtesy of Xylem)It was also important that the pumps had the ability to integrate with the SIRWA supervisory control and data acquisition (SCADA) network. The solution needed to meet National Safety Foundation (NSF)-61 requirements.
Delivering a Customized Portable Solution
SIRWA teamed with a longtime pump and industrial equipment partner. The distributor designed a customized engineered-to-order solution for SIRWA. The manufacturer supplied two diesel-driven pumps equipped with liquid bath mechanical seals to address dry-running requirements.
The pumps offer flow rates up to 1,320 gpm—more than enough to meet the 900 gpm flow capacity needed to support the pumping stations within the SIRWA coverage area. The pumps were also equipped with 375 gallon fuel tanks, more than twice the size of a standard tank, allowing the pumps to run approximately 70 to 80 hours at full load on one tank of diesel should there be a long-term power outage.
The solution was customized to meet NSF-61 certification requirements. A number of pump components were treated with a certified NSF-61 coating and the pumps were connected to the SIRWA network with 6-inch food-grade hoses approved by the NSF. Additional safety customization included work lights and roadside hazard lights to support night and emergency work.
Image 2. The controller was customized for each pump, allowing SIRWA to monitor and control the pump activity remotelyTo ensure portability, the pumps were each installed on customized trailers and accessories, including a toolbox, spare tire, night work lights and an 8 kilowatt (kW) generator. Each pump trailer was outfitted with a hose rack and 100 feet of the NSF-approved 6-inch hose. The trailers were equipped with a gooseneck hitch to accommodate easy connections with the trucks that would be called on to tow the pumps within SIRWA’s coverage area.
The distributor and manufacturer team recommended that the trailer also carry a state-of-the-art controller, powered by the pump battery that would allow the pump to tie into SIRWA’s SCADA system. The controller enabled SIRWA to monitor and control pump activity remotely, and could plug into the SCADA system at any pump station across the SIRWA network.