Microbiological quality of bottled water brands sold in retail outlets in New Zealand

The microbiological quality of bottled water has been studied over the past 30 years as bottled water can contain pathogens. The aim of this study was to determine if retailed bottled water in New Zealand complied with the Australia and New Zealand Food Standards (ANZFS) Code (2002) and the New Zealand Microbiological Reference Criteria (1995). Thirty-eight domestic and imported bottled water brands were tested for Total Coliforms, Escherichia coli, Pseudomonas aeruginosa, Enterococci, HPC, Yeasts and Moulds. Three brands did not comply with both of the above criteria for Total Coliforms. Seventeen brands did not comply with HPC criteria and 21 brands displayed mould growth. A questionnaire was used to assess the impact of manufacturing procedures on bottled water quality. Four responding manufacturers, which represented 11 bottled water brands, bottled at least one brand that did not comply with the ANZFS Code for HPC. Our study demonstrated that even 10 years after the initial study in New Zealand microbiological contamination in bottled waters was still being detected. We further demonstrated that monitoring of bottled water microbiological quality was essential and that the presence of manufacturers' procedures for ensuring satisfactory bottled water microbiological quality did not always guarantee it.