Impact of bottled water storage duration and location on bacteriological quality

An investigation studying the effects of storage duration and location on the persistence of heterotrophic microorganisms in oligotrophic bottled water environments has been completed. One-gallon high-density polyethylene water containers stored for up to 16 weeks at temperatures ranging from 2 degrees C to >49 degrees C in a refrigerator, indoor cabinet, covered porch, and car trunk were evaluated for microbiological quality. Heterotrophic plate counts (HPCs) of up to 4 x 10(3) cfu/mL were detected in containers stored on a porch and car trunk; whereas, HPCs were found not to exceed 400 cfu/mL and 100 cfu/mL for bottles stored in indoor cabinets and refrigerators, respectively. Containers stored on an enclosed porch for up to seven years contained HPC of up to 4 x 10(4) cfu/mL. Logistic and Gompertz growth models predicted microbial growth rates for bottled water stored on a protected porch environment for long (R-2 0.99) and short-term (R-2 0.86) durations.