DEVELOPMENT OF A MEMBRANE FOULING INDEX BASED ON PILOT STUDIES WITH LOW PRESSURE MEMBRANES OPERATED UNDER VARYING CONDITIONS AND WATER QUALITIES.The primary goal of this WRF funded research was to (i) contrast NOM-related fouling potential for different types of waters (allochthonous versus autochthonous); (ii) develop a predictive tool(s), either a surrogate parameter(s) or a fouling index, to estimate fouling potential. Interactions between water quality, pre-treatment chemicals, membrane materials, and membrane configurations were tested at pilot-scale under various operating conditions.