Rapid determination of bacteria in pools

If a method for rapid determination of bacterial levels in swimming pools and whirlpools were available, bacterial health risks could be avoided before exposure occurred. Such a method would enable public-health authorities to make timely decisions about closing or reopening pools and to adjust disinfectant doses. The purpose of this study was to determine if a rapid adenosine triphosphate (ATP) bioluminescence method would serve this purpose. Bacteriological analyses were completed on samples from swimming pools and whirlpools in Washtenaw County, Michigan. The results from the ATP assay were compared with those from the conventional plate count method and were found to be highly correlated (r = .92). To assess whether a prefiltration step was necessary to delete nonbacterial ATP--which might originate from bathers' skin cells or other debris--two procedures were tested: one with prefiltration and one without prefiltration. The results for prefiltered samples were not statistically different from the results for non-prefiltered samples (p > .05), for both the heterotrophic plate counts and the ATP bioluminescence method. This study indicates that the ATP assay can estimate bacterial levels in pools within minutes and without prefiltration.