Evaluating Fouling Characteristics and Cleaning Methods After Lime Softened

Water District No. 1 of Johnson County, Kansas (WaterOne) is a large utility that supplies water to approximately 340,000 people in the Kansas City metropolitan area. Currently, WaterOne is planning a new 30 mgd treatment facility that will treat Missouri River water withdrawn through horizontal collector wells. One proposed treatment process would include lime softening and filtration by MF/UF membranes. WaterOne and Black & Veatch performed a 6 month pilot study to evaluate the potential effects of limesoftened water, specifically water with pH of 9.5 and calcium carbonate precipitation potential greater than 20 mg/L as CaCO3, on the MF/UF membranes. The pilot testing extended over several seasons, so the impact of water temperature, TOC increases with spring runoff, and process changes upstream of the membrane systems were investigated.