Riverbank Filtration Case Study at Louisville, Kentucky

The results of NOM and disinfection byproduct precursor removal indicate that more than a 50-percent reduction in disinfection byproduct precursors can be achieved through the RBF process at Louisville with a filtration depth of 15 m. Biodegradation and the physical removal of particulate matter at the river/aquifer interface are the primary mechanisms for NOM and disinfection byproduct precursor removal. Adsorption may also play a role in further NOM reduction as the filtration depth increases. The results of turbidity, total coliform, HPC, total aerobic spores, and microscopic particulate analysis show that the RBF process is very effective in removing particles in surface water, suggesting that it is an effective water-treatment process for reducing the potential of microbial contamination in drinking water. The results also show that the removal efficiency increases with the filtration depth, with most of the removal occurring within the firstmeter of filtration. Data from total coliform, total aerobic spores, and microscopic particulate analysis suggest that a >2.5-log removal credit can be given to this RBF system.