Drinking Water in the NWT

Monitoring and Testing – Proving Water is Safe

Community governments are responsible for regular testing of drinking water. This process includes taking samples, submitting them to a lab, and then examining the results to ensure the safety of the community water supply.

Testing and Monitoring of Treated Water Quality Data

  • Verifies the quality of drinking water and allows for quick intervention as required.

Testing occurs at the following intervals:

  • E. coli and Total Coliforms: For treated water delivered through a piped system, a minimum of four samples are required each month (additional samples are done for populations over 4000), and they are normally taken weekly. For treated water delivered by truck, at least one sample is required from each truck in use each month, plus samples from public buildings. For all systems, one raw water sample per month is required.
  • Chlorine: Treated water samples are taken every day to check chlorine levels in the plant’s storage tank and in delivery trucks. Many plants also have continuous monitoring by inline meters in the treatment system. Raw water samples are not done for chlorine, as it is added during treatment.
  • Turbidity: One raw water sample is taken per day. Where practical, plants have continuous monitoring of treated water turbidity by inline meters in the treatment system. Where this is not practical, at least one treated water sample is taken each delivery day, with an additional sample taken for every four hours of plant operation.
  • Trihalomethanes (THMs): Treated water samples are taken quarterly, with a minimum of four per year. Raw water samples are not needed.
  • Chemical and Physical Parameters: One treated water sample is done every year to check a suite of 28 parameters, which are listed in the left menu.  Raw water samples for the same 28 parameters are taken if the treatment process includes any technologies other than chlorine or UV disinfection; disinfection alone does not alter these parameters, so no raw water sample is required for disinfection-only systems

Environmental Health Officers with the Department of Health and Social Services are responsible for reviewing test data and taking action if any test results exceed the Guidelines for Canadian Drinking Water Quality.

Public Access to Water Quality Data

  • Keeps the public informed, allowing them to make informed decisions about drinking water usage. 
  • Water quality data for 2018 can be found here 
  • Water quality data for 2019 can be found here
  • Water quality data for 2020 can be found here
  • Water quality data for 2021 can be found here
  • Water quality data for 2022 can be found here
  • Water quality data for 2023 can be found here

Public Notifications (Boil Water Advisories)

  • Lets the public know if there is a problem and what actions are required to correct it.
  • Holds officials accountable to the public, building confidence in the system, and provides an opportunity for public education.

Public Reporting On NWT Drinking Water Quality

  • Provides annual public account of drinking water status in the NWT.
  • Provides an opportunity for highlighting trends and discussion of major issues.

Assessment of Water Treatment Infrastructure and Operations

  • Helps ensure that Water Treatment Plant infrastructure is in good condition, and is being operated and maintained safely.

Public Education

  • Assuring the public that the water supply is safe and reliable by informing them about tests and testing results, and who is responsible.