Mapping Drinking Water Systems for Population Exposure Assessment

Drinking water is a recognized pathway through which populations can be exposed to biological and chemical hazards. We mapped Ontario Municipal Drinking Water Distribution systems (DWDS) by matching census areas to images of drinking water pipe networks. The new maps enable ongoing epidemiological research and surveillance by allowing linkage of both drinking water monitoring data and administrative health data sets to the residence of the population served.The location of drinking water distribution pipes for systems serving a population of 5,000, or more, were obtained from the Ontario Ministry of Environment and Climate Change (MOECC). Images of pipe networks varied widely in resolution and detail, and were scaled and aligned by a GIS analyst using Google Earth and ArcMap v10.3. The smallest geographic areas for which Canadian census includes population, age and sex data i.e. “dissemination areas” (DAs) were used to approximate the boundaries of water systems.The selected DAs were spatially...