Springfield, Illinois, has long relied on the Spring Creek Wastewater Treatment Plant to protect public health and local waterways. Originally built in 1929, the manually operated facility had far exceeded its operational lifespan by the early 2000s. With aging equipment and increasing regulatory demands, the Sangamon County Water Reclamation District initiated plans to replace the plant with a modern, fully automated facility.
The new design had to accommodate Springfield’s combined sewer system, which handles both wastewater and stormwater. This presented a unique challenge: incoming flow could vary dramatically, especially during heavy rainfall. Pumps at the new facility would need to perform reliably under both normal and peak conditions, while supporting advanced biological treatment processes.
The solution
To meet these demands, the SCWRD specified several Pentair Fairbanks Nijhuis pumps, including 10 12-inch Vertical Close-Coupled Angleflow pumps dedicated to the return activated sludge function. These pumps are essential to the activated sludge process, which relies on a stable population of microorganisms to break down organic contaminants.
RAS pumps recirculate settled biomass from the secondary clarifier back into the aeration basin, maintaining microbial health and process efficiency.
The Angleflow pumps selected for Springfield are engineered to handle high-solids sludge with minimal shear, preserving the integrity of biological floc. Their large-passage impellers allow fibrous materials to pass through without clogging, while precision-cast components reduce turbulence and wear.
Additional features such as thick-walled volutes, heavy-duty bearings and corrosion-resistant shafts ensure long service life under demanding conditions. The pumps operate in a cascading control sequence, providing continuous flow and built-in redundancy for maintenance. This design supports uninterrupted biological treatment, even during peak storm events.
The results
Since opening in 2012, the new Spring Creek facility has consistently met its performance goals. The Fairbanks Nijhuis pumps manage a daily flow of 16 million gallons and can handle up to 120 million gallons during storms. Their reliability earns praise from SCWRD leadership and design firm Crawford, Murphy & Tilly.
Gregg Humphrey, executive director of SCWRD, highlights the ease of obtaining parts and the pumps’ U.S.-based manufacturing. Christy Crites, vice president at Crawford, Murphy & Tilly, emphasizes the long-term value of investing in high-quality equipment: “To go with a quality piece of equipment like a Pentair pump is going to pay for itself over and over again.”
As wastewater treatment evolves to address emerging contaminants and stricter standards, foundational systems like RAS pumps remain critical. The Springfield case demonstrates how thoughtful pump selection and robust design can ensure biological stability, operational resilience and environmental protection for decades to come.
Fairbanks Nijhuis is a division of Pentair that delivers tailored pumping solutions for municipal, industrial and commercial sectors. With over two centuries of expertise, the brand specializes in custom-engineered pumps like vertical turbine and split-case models, focusing on efficiency, innovation and sustainable water management worldwide.
