The experiments were performed using both batch and continuous column reactors. Batch biodegradation studies were performed under aerobic conditions to determine the biodegradable fraction of the natural organic matter (NOM) source. NOM source was evaluated for its biodegradability at three different UV irradiation conditions and compared to its biodegradability without UV irradiation. In continuous experiments, system operating parameters of empty bed contact time (EBCT), recycle ratio, and influent concentration affected the extent of biofiltration in the biofilters. The effluent UV254/DOC ratios fro the biologically active columns were consistently lower than the influent values, which indicated that the dissolved organic carbon (DOC) removed by biodegradation was not a significant part of the UV-absorbable material. The increase in UV254/DOC ratio was caused by the DOC decrease across the biofilter because there was essentially no difference between the feed and effluent UV254 absorbance values over time. The results of this research showed that biofiltration was an effective method for removing the biodegradable fraction of NOM from water supplies.