Reduction in Disinfection Byproduct Precursors and Pathogens During Riverbank Filtration at Three Midwestern United States Drinking-Water Utilities

The three sites investigated during this project demonstrated the ability of RBF to effectively reduce a variety of microbial contaminants, TOC, DOC, disinfection byproduct precursor material, and total theoretical THM cancer risk. TOC and DOC reductions ranged from 35 to 67 percent for the closest wells at the three sites. Total THM FP and HAA FP reductions ranged from 57 to 73 percent and 50 to 78 percent, respectively. The higher reduction in disinfection byproduct precursor concentrations compared to TOC or DOC suggests a preferential removal of precursor material. In addition, a shift was observed upon RBF from the chlorinated to the more brominated disinfection byproduct species.