DOI: 10.25976/4der-gd31
title: GNWT ECC NWT-Wide Community Based Monitoring Program_Water Quality Data

description: The Northwest Territories Community-Based Monitoring (CBM) Program was established in 2012 under the Northern Voices, Northern Waters strategy to support Indigenous-led water stewardship across the territory. Co-developed by the Government of the Northwest Territories (GNWT–Environment and Climate Change) and more than 21 Indigenous communities organization, government and land guardian programs, the program centres on a shared question: What’s in our water, and how is it changing? Today, community monitors collect water samples at 63 sites across the NWT, while the GNWT provides training, equipment, and laboratory analysis to support consistent, high-quality data collection.

Water quality data are collected primarily during the open-water season, typically from June to October. Monitoring includes surface grab sampling for over 90 water quality parameters; continuous two-hour interval measurements of temperature, conductivity, dissolved oxygen, turbidity, chlorophyll, pH, and ORP using YSI EXO2 sondes; and the deployment of polyethylene membrane devices to capture hydrocarbons.

The CBM program is part of a broader territorial Partnership Aquatic Quality Monitoring network, encompassing approximately 90+ sites across the North Slave, South Slave, Beaufort Delta, Sahtu, Great Slave Lake, and transboundary river regions. Together, these collaborative monitoring efforts provide long-term data needed to track water quality trends, support community priorities, and strengthen understanding of how waters across the Northwest Territories are changing over time.
This dataset is specific to the surface water quality grab sample data and the polyethylene membrane devices (PMDs) data.

This dataset is linked to the continuous Sonde (YSI) Data found here: https://doi.org/10.25976/5dfl-rw63
description: The CBM program collected data for a wide range of parameters using up to four types of water quality sampling
techniques/monitoring equipment:

• Polyethylene Membrane Devices (PMDs) – PMDs passively sample for a suite of parent and alkylated dissolved polycyclic aromatic hydrocarbons (PAHs) over a 15 - 30 day period. Analyses of these passive samplers were completed by Dr. Mingsheng Ma and his team at the Biogeochemical Analytical Service Laboratory at the University of Alberta.

• Surface grab water samples – each suite of surface grab water samples are analyzed for over 90+ parameters. This includes basic parameters (such as turbidity, specific conductivity, pH and alkalinity), nutrients, major ions, organics, and dissolved and total trace elements. In 2016, where feasible, bacteriological sampling was added to the suite, and continued to be sampled in subsequent years. Surface grab water samples were collected from all sites monthly during the field season (June – October), which resulted in 3-5 samples per year depending on the location of the sample site. The surface grab water samples were analyzed at the Taiga Laboratory in Yellowknife, NT.
description: All water quality data underwent a multi-step quality assurance and quality control (QA/QC) review prior to interpretation. Laboratory analyses were assessed to ensure that all parameters met required holding times; any samples exceeding holding time requirements were removed from the dataset unless otherwise justified. Detection limits (DLs) were pre-established in consultation with the laboratory to ensure they were as low as reasonably achievable. When parameters were reported above the agreed-upon DLs, re-analysis at lower detection limits was requested where feasible.
Field and travel blanks were evaluated for potential contamination. Any parameter detected above the DL in a blank was flagged, along with the same parameter in associated grab samples. In most cases, both blanks and affected samples were re-analyzed. Some exceptions were made for parameters such as total and dissolved aluminum and zinc, which the laboratory routinely reports near the DL; if blank concentrations were close to the detection limit, re-analysis was not automatically required.

Replicate samples were compared to assess analytical precision. Replicates showing a relative percent difference (RPD) greater than 15% were flagged for review. If replicate values were near the detection limit (e.g., 0.2 vs. 0.3 µg/L for copper), re-analysis was generally not pursued due to expected variability at low concentrations. For higher-level discrepancies, both replicates were submitted for re-analysis.

Total and dissolved metal concentrations were also cross-checked for consistency. Dissolved concentrations should always be lower than total concentrations; therefore, any dissolved value exceeding the total value by more than 20% (i.e., 1.2 times higher) was flagged, and both total and dissolved fractions were re-analyzed. Similar to replicate review, professional judgment was applied when values were near detection limits.

This QA/QC process ensures that final datasets represent reliable, defensible water quality information that can be confidently used to support community and territorial decision-making.