Drinking water in the vast Arctic Canadian territory of Nunavut is sourced from surface water lakes or rivers and transferred to man-made or natural reservoirs. The raw water is at a minimum treated by chlorination and distributed to customers either by trucks delivering to a water storage tank inside buildings or through a piped distribution system. The objective of this study was to characterize the chemical and microbial drinking water quality from source to tap in three hamlets (Coral Harbour, Pond Inlet and Pangnirtung-each has a population of <2000) on trucked service, and in Iqaluit (population ~6700), which uses a combination of trucked and piped water conveyance. Generally, the source and drinking water was of satisfactory microbial quality, containing Escherichia coli levels of <1 MPN/100 mL with a few exceptions, and selected pathogenic bacteria and parasites were below detection limits using quantitative polymerase chain reaction (qPCR) methods. Tap water in households receiving trucked water contained less than the recommended 0.2 mg/L of free chlorine, while piped drinking water in Iqaluit complied with Health Canada guidelines for residual chlorine (i.e. >0.2 mg/L free chlorine). Some buildings in the four communities contained manganese (Mn), copper (Cu), iron (Fe) and/or lead (Pb) concentrations above Health Canada guideline values for the aesthetic (Mn, Cu and Fe) and health (Pb) objectives. Corrosion of components of the drinking water distribution system (household storage tanks, premise plumbing) could be contributing to Pb, Cu and Fe levels, as the source water in three of the four communities had low alkalinity. The results point to the need for robust disinfection, which may include secondary disinfection or point-of-use disinfection, to prevent microbial risks in drinking water tanks in buildings and ultimately at the tap.
The increasing prevalence of antibiotic resistance genes (ARGs) in the environment is problematic due to the risk of horizontal gene transfer and development of antibiotic resistant pathogenic bacteria. Using a suite of monitoring tools, this study aimed to investigate the sources of ARGs in a rural river system in Nova Scotia, Canada. The monitoring program specifically focused on the relative contribution of ARGs from a single tertiary‐level wastewater treatment plant (WWTP) in comparison to contributions from the upgradient rural, sparsely developed, watershed. The overall gene concentration significantly (p < 0.05) increased downstream from the WWTP, suggesting that tertiary‐level treatment still contributes ARGs to the environment. As a general trend, ARG concentrations upstream were found to decrease as proximity to human‐impacted areas decreased; however, many ARGs remained above detection limits in headwater river samples, which suggested their ubiquitous presence in this watershed in the absence of obvious pollution sources. Significant correlations with ARGs were found for HF183 human fecal marker, Escherichia coli, and some antibiotics, suggesting that these markers may be useful for prediction and understanding of ARG levels and sources in rural rivers. Core Ideas Tertiary wastewater treatment contributed antibiotic resistance genes (ARGs) to the river. ARG levels decreased as proximity to anthropogenic influence decreased. ARGs were observed at detectable levels even in undeveloped headwaters. High flow conditions correlated to high ARG loading in the river. Positive correlations were found between ARGs and fecal indicators.
In the Canadian Arctic, the availability of sustainable drinking water supplies is threatened by pressures such as increasing populations, climate change, and the remote geographic nature of the communities. The objective of this study was to conduct a screening level vulnerability assessment of municipal drinking water supplies in the Canadian territory of Nunavut with consideration for climate change, population growth, and infrastructure changes. A hydrological analysis of primary drinking water supply watersheds was performed to evaluate the relative vulnerability level in 24 Nunavut communities. We used a water balance model to predict annual water yield from each watershed using historical and projected future climate data. Approximately 25% of the study communities were projected to experience high vulnerability to water shortages by 2070, defined as using greater than 40% of available water from their source watershed on an annual basis. A medium level of vulnerability (using 20% – 40% of annual available water) was determined for 8% of the study communities and a moderate level for 12% (using 10% – 20% of annual available water). A low vulnerability level to 2070 (using less than 10% of annual available water) was determined for 55% of the communities. The vulnerability level was primarily influenced by source watershed size. The results of this study could be used as a component of a proactive strategy to help address water security issues in Nunavut.
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