The rapidly changing climatic conditions at global, national and regional scales are causing significant changes in water quality. In this topical session we will focus on studies that investigate how factors such as ecosystem alterations including forests and soils, chemical signatures such as dissolved organic matter and nutrients, and biological alterations such as algal growth have impacted the quality of surface and potable water. Studies that discuss links between the factors above and disinfection byproduct (DBP) formation in drinking water treatment processes as well as characterization methods (including but not limited to FT-ICR-MS, NMR, nano-SIMS and STXM) used for organic matter in soil and water, and organic-mineral interactions and DBPs are especially encouraged.