The primary objectives of this study were to determine the relative effectiveness of the MIEX®, coagulation and enhanced coagulation treatment processes for the removal of dissolved organic carbon (DOC) from the water, and their effects on the biological stability, chlorine demand and trihalomethane formation potential (THMFP) of the treated water. The proportions of various sub-fractions of DOC (i.e., assimilable organic carbon (AOC) and UV₂₅₄-active DOC) that were removed at each step of the treatment process were determined. The change in the molecular weight distribution of the UV₂₅₄-active DOC at each step during the treatment process was determined using high performance size exclusion chromatography (HPSEC). Includes 10 references, figures.