Background
Many Inuit in Nunavut still prefer to collect their drinking water directly from rivers, lakes, ponds, streams, and even from ice bergs and sea ice. Water from these traditional sources is considered by many to be better tasting, cleaner, and superior in quality to treated tap water. A wide variety of microorganisms can exist in surface waters and the microbial diversity of Arctic water bodies could change in the future as new species move northward. Treated water distributed through Nunavut’s community drinking water systems is tested regularly but very little is known about microbial condition of the many lakes, rivers and streams that are used as sources of untreated drinking water.
Most microorganism pathogens in surface water are very difficult, costly, and time consuming to measure. Defined substrate technology (DST) kits allows for rapid detection and enumeration of indicator bacteria in surface water without the requirement to culture bacteria. DST testing is widely utilized by accredited laboratories across North America and has been recommended as a tool for water quality monitoring in Inuit communities.
The Nunavut Research Institute received funding under Health Canada’s Climate and Health Adaptation in Northern First Nations and Inuit Communities Program in 2009 to use DST kits to monitor surface water quality of two rivers; the Apex (Niaqungut) and the Sylvia Grinnel). Iqaluit residents collect drinking water from both rivers throughout the ice free period.
Our project had 2 goals:
- To determine whether the Nunavut Research Institute staff and local college students could carry out DST tests reliably and effectively; and
- To describe the trend in bacteria levels and water temperature over the course of the open water period in both rivers and identify the timing of peak bacteria levels.
Collecting and Testing the Water Samples
Leia Sowdloapik-Cunningham holding Colisure Tray and UV light used for E coli detection
Arctic College Environmental Technology Program Student David Nakasuk records field data at Apex River
Water samples were collected regularly from Apex and Sylvia Grinnel rivers from June 17 to October 13, 2009 at sites where residents typically collect drinking water. Samples were tested at the NRI water quality laboratory in Iqaluit using the DST test kits Colisure™ (for Total Coliforms and E. coli), and Enterolert™ (for Enterococci). NRI summer student Leia Sowdloapik Cunningham (now Nunavut’s first Inuk veterinarian) participated in, and eventually led, the sample collection and testing. The DST testing procedure (inoculating, incubating samples) was very straightforward, and the test results were clear and easy to interpret. No Total Coliforms, E. coli or Enterococci were detected in any of the field and lab blanks tested.
What We Learned
Total Coliforms were detected in all 38 samples tested from Apex River, and in all 23 samples tested from Sylvia Grinnell. The average Total Coliforms in the smaller Apex River (catchment size = 60km²) was 208 colony forming units (cfu) per 100ml (n=38, Standard error = 26 cfu/100ml) while the average in larger Sylvia Grinnell River (catchment size = 3000km²) was 101.7 cfu/100ml (n=23, Standard error=13 cfu/100ml). The range of Total Coliform concentrations in Apex River (16 to 547 cfu/100ml) was greater than in Sylvia Grinnel (19.9 to 189.2 cfu/100ml).
Peak concentrations of Total Coliform concentrations in both rivers were observed in late July when water temperatures were highest. The range and variability of Total Coliform concentrations was also greatest in late July in both rivers; greater sample frequency might be required for monitoring during the peak summer period. Total Coliform concentrations were lower in the early summer (mid June to mid July) and in the early fall (late August to early October) compared to mid summer (July). The lowest Total Coliform concentration in both rivers was observed on the last day of sampling (October 13) when water temperature was also lowest in both rivers.
Only two samples (8%) from Sylvia Grinnell tested positive for Eshcerichia coli; both samples had only 1 CFU/100ml of E. coli. E. coli was detected in 6 (16%) of samples from Apex river at levels ranging from 1 to 5.2 CFU/100ml; the highest E coli level in Apex was detected on July 28.
No Enterococci were detected in any of the samples from Apex or Sylvia Grinnell.
Figure 1. This graph shows the concentrations of total coliforms in relation to water temperature at the time of sampling (red dots indicate the coliform concentration of individual samples); coliform concentrations were positively correlated with water temperature in both rivers, meaning thatr coliform concentrations increased as water temperature increased. The relationship between coliform levels and water temperature was slightly stronger in Apex river than in Sylvia Grinnel River.
Figure 2. This graph tracks concentrations of total coliforms in both rivers over the course of the sampling period, June to October (red dots indicate the concentrations in individual samples tested). Note that in both rivers coliform concentrations started low, then steadily increased to a peak in late July (when water temperatures were highest). The concentrations then began to decline; lowest concentrations in both rivers were measured at the end of the sampling period.
Figure 3. This graph shows the range of coliform concentrations in samples from Apex and Sylvia Grinnel rivers. A wider range of coliform concentrations was detect in Apex River than in Sylvia Grinnel River.
Communications and Follow Up
An information bulletin in English and Inuktitut with photographs and a description of the project methods was featured on the Nunavut Arctic College website in August 2009. The print edition of Nunavut News North also ran a short story on the project in July 2009. We also periodically reported our test results to the Nunavut Department of Health (Environmental Health Division) and to the City of Iqaluit (Public Works and Planning and Lands Divisions). The City of Iqaluit’s Public Works Division used our study results in their application to the Nunavut Water Board for renewal of Iqaluit’s municipal water license for 2011. The final project report was circulated to the other agencies that provided support letters for the project. Results will be presented in person to the Iqaluit municipal council in 2012.
We continued to monitor E coli and Total Coliform concentrations in Apex River in 2010 and 2011 to further track seasonal variations and to better understand how bacteria levels relate to water temperature during the ice free period. Our experience to date suggests that with basic training and the necessary equipment, community members are able to conduct reliable, accurate, consistent monitoring of microbial water quality using DST test kits. We hope to continue annual monitoring at Apex River with participation of Arctic College students, and to examine other complex environmental factors (e.g. turbidity, precipitation, pH, conductivity, and substrate) that might influence microbial water quality.
