This paper describes how a bench-scale cross-flow unit was used to evaluate cleaning strategies with a sulfonated polyethersulfone ultrafiltration (NTR7410) membrane, which is relatively hydrophobic, based on contact angle, and exhibits a negatively-charged surface, based on zeta potential and FTIR spectrum. Cleaning strategy tests were performed with Horsetooth Reservoir surface water and Orange County groundwater reflecting relatively hydrophilic and hydrophobic natural organic matter sources, respectively, based on their SUVA and humic-content values. Includes reference, tables, figures.