An analysis of the microbial quality of water in a milk production plant

- Microbiological quality of dairy water use over a two year period.
- Quality issues were observed for the chill water tower.
- A temporal trend in water quality was observed.
- Analysis provided recommendations for sampling prioritisation.

This study analysed microbiological and chemical sampling quality results of the water supply used in a milk production plant over a two-year period. Four sampling points were tested six days a week (n = 2032) and results were compiled for total coliforms, Escherichia coli, Enterococcus and total bacterial counts (TBC) at 21 °C, 30 °C and 37 °C as well as total and free chlorine. A significant difference in microbiological quality was found to exist between the cooling tower and the other sampling locations (F = 45.860, P < 0.001), with post-hoc analysis indicating a particularly significant difference for TBCs at 30 °C (P < 0.001). The results of this study identified contamination issues associated with the cooling water in terms of the heterogeneity of both microbiological and chemical concentrations and recommended the inclusion of further sampling parameters to further identify causation factors. For the non-cooled water sampling locations, homogeneity in quality suggested that reduced sampling frequency could be implemented, thus reducing cost. The results of this study propose that in-depth analysis of both microbiological and chemical sampling results within a dairy plant can facilitate in the more cost effective sampling procedures and offer valuable insight into the development of site specific protocols.