An evaluation of southeastern Ontario recreational water quality.

Fecal contamination in recreational waters causes adverse health outcomes in humans; yet, surprisingly, a paucity of literature addresses recreational water quality in North America. The authors addressed this gap by evaluating E. coli contamination of southeastern Ontario, Canada, recreational beach waters between the years 2008-2011. They tested water samples for microbial contamination by the membrane filtration method. They used Friedman's and repeated measures analyses of variance and descriptive statistics to assess annual and monthly E. coli levels as well as noncompliance to the Ontario bathing beach standard. Seven waters showed high noncompliance to the Ontario standard, which could negatively affect the health of local recreational beach users. The authors' study provides much needed baseline information on beach water quality. They call for greater recreational water sampling and reporting standardization across North American jurisdictions.

Microbial source tracking and spatial analysis of E. coli contaminated private well waters in southeastern Ontario.

Private water supplies, which are the primary source of drinking water for rural communities in developed countries, are at risk of becoming fecally contaminated. It is important to identify the source of contamination in order to better understand and address this human health risk. Microbial source tracking methods using human, bovine and general Bacteroidales markers were performed on 716 well water samples from southeastern Ontario, which had previously tested positive for Escherichia coli. The results were then geospatially analyzed in order to elucidate contamination patterns. Markers for human feces were found in nearly half (49%) of all samples tested, and a statistically significant spatial cluster was observed. A quarter of the samples tested positive for only general Bacteroidales markers (25.7%) and relatively few bovine specific marker positives (12.6%) were found. These findings are fundamental to the understanding of pathogen dynamics and risk in the context of drinking well water and will inform future research regarding host-specific pathogens in private well water samples.

A spatial analysis of private well water Escherichia coli contamination in southern Ontario.

Research to date has provided limited insight into the complexity of water-borne pathogen transmission. Private well water supplies have been identified as a significant pathway in infectious disease transmission in both the industrialised and the developing world. Using over 90,000 private well water submission records representing approximately 30,000 unique well locations in south-eastern Ontario, Canada, a spatial analysis was performed in order to delineate clusters with elevated risk of E. coli contamination using 5 years of data (2008-2012). Analyses were performed for all years independently and subsequently compared to each other. Numerous statistically significant clusters were identified and both geographic stability and variation over time were examined. Through the identification of spatial and temporal patterns, this study provides the basis for future investigations into the underlying causes of bacterial groundwater contamination, while identifying geographic regions that merit particular attention to public health interventions and improvement of water quality.