Microbial contamination in drinking water at public outdoor recreation facilities in New Zealand

The aim of our study was to assess the presence and risk of waterborne pathogens in the drinking water of outdoor facilities in New Zealand and track potential sources of microbial contamination in water sources.

A serial cross-sectional study with a risk-based sample collection strategy was conducted at 15 public campgrounds over two summer seasons (2011-2012 and 2012-2013). Drinking water supplied to these campgrounds was not compliant with national standards, based on Escherichia coli as an indicator organism, in more than half of the sampling occasions. Campylobacter contamination of drinking water at the campgrounds was likely to be of wild bird origin. Faecal samples from rails (pukeko and weka) were 35 times more likely to return a Campylobacter-positive result compared to passerines. Water treatment using ultraviolet (UV) irradiation or a combination of filtration and UV irradiation or chemicals was more likely to result in water that was compliant with the national standards than water from a tap without any treatment. The use of filters alone was not associated with the likelihood of compliance.

Providing microbiologically safe drinking water at outdoor recreational facilities is imperative to avoid gastroenteritis outbreaks. This requires an in-depth understanding of potential sources of contamination in drinking water sources and the installation of adequate water treatment facilities.

Our study provides evidence that drinking water without treatment or filter-only treatment in public campgrounds is unlikely to comply with national standards for human consumption and extra water treatment measures such as UV irradiation or chemical treatment are needed.