The objective of this research was to investigate the effect of water quality on Henry's law constants for compounds of different physical-chemical properties. Dimensionless Henry's law constants (m) of geosmin and chloroform were measured with varying total dissolved solids (TDS) (0-450 mg/L), total organic carbon (TOC) (0-5 mg/L), temperature (25 ºC, 40 ºC and 60ºC), and concentration (ng/L and µg/L levels) to investigate the effect of water quality on Henry's law constants. Considering increasing consumers' desire for a safe and palatable drinking water (McGuire 1995; Mackey, Davis et al. 2003; Dietrich 2006; Burlingame, Dietrich et al. 2007), this type of research is necessary for assessing human exposure to contaminants in drinking water. Includes 13 references, figures.