Engineer: AECOM
Contractor: Shook
IX Resin: CalRes 2301
In late 2020 Warren County Water started construction on a new nanofiltration membrane softening facility. The facility was designed to blend a mixture of softened water & bypass water that was not treated by the membrane filtration system. This allows the plant operations staff to target a desirable level of hardness before distribution to their customers.
After construction of the new softening plant had because PFAs (Perfluoroalkyl compounds) were found in the plant’s source water. The NF membranes would remove these compounds from the water being processed by the membranes. However, only a portion of the water is softened, and the PFAS levels in the blend water would cause regulatory issues for the utility.
Warren County began evaluating PFAS treatment technologies to treat the membrane-bypass water, ensure compliance, and provide customers with safe drinking water. Warren County and their engineering group evaluated the initial capital cost, operational cost, and required footprint for both granular activated carbon and ion exchange resins.
Both types of media were found to effectively remove the contaminants. The primary issue for Warren County was the limited area they had to accommodate the new treatment process. They had just built a brand-new softening facility that they did not want to expand. The IX resins had much faster reaction kinetics that allow the use of fewer & smaller vessels. Based on the column testing results it was found that Calgon’s CalRes 2301 was the best performing IX resin. It was determined that (3) 10’ diameter systems would be suitable for treatment and fit in the newly built softening building.
Warren County procured the vessels in late 2024, bid out installation services in early 2025, and brought the system online in November of 2025.
