No direct information exists on the role biofilm may play in the bacterial quality of water in
aircraft drinking water storage tanks (tanks). The primary objective of this study was to
investigate how biofilm impacts bacterial water quality in tanks. A secondary objective was to
assess how effective current tank disinfection was in minimizing biofilm. Bench-scale biofilm
reactors were utilized to model the draw-fill cycles encountered during aircraft operations. The
bacterial quality of stored water was evaluated utilizing two tap water source types (surface
water and groundwater) and three water quality conditions (un-amended tap water and tap water
amended with organic carbon or calcium hardness). Two plastic materials used to line aircraft
storage tanks (ABS- acrylonitrile butadiene styrene and PETG- glycolised polyester) were
evaluated. Heterotrophic plate counts for the stored water and biofilm were measured to
determine how the various parameters affect bacterial water quality. Includes 8 references, table, figures.