AWWA JAW65525

This study set out to quantify the contributions of subsurface filtration (or underground passage) and groundwater dilution to overall reductions/removals by riverbank filtration (RBF). Samples were collected from four RBF study sites that varied in terms of distance between river sources and extraction wells, river water quality, hydrology, well construction and pumping rate, and subsurface material. Samples were analyzed for removal of dissolved organic carbon, total coliforms, aerobic spore-forming bacteria, and virus indicators. Results indicated that the relative contribution of each removal mechanism was site-specific. Both groundwater dilution and subsurface filtration appeared to be important reduction/removal processes. Within the United States, RBF is a relatively unfamiliar drinking water treatment. The findings presented here indicate that RBF can be effective as both a primary treatment and a pretreatment process and can significantly improve the quality of river water in terms of particulates, organic precursors, and microbial removals. Includes 24 references, tables, figures.