DOI: 10.25976/5dfl-rw63
title: GNWT ECC NWT-Wide Community Based Monitoring Program_Continual Sonde (YSI) 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 centers 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 YSI EXO 2 sondes. These devices collect continuous data, including:  water temperature, conductivity, dissolved oxygen, turbidity, chlorophyll, pH, and ORP every 2-hours for the duration of the open-water season. Data collected by the sondes is interpreted by ECC staff. 

This dataset is linked to the grab sample data found here: https://doi.org/10.25976/4der-gd31
description: YSI Sondes and EXO 2 Sondes – Sondes measure temperature, conductivity, dissolved oxygen, turbidity, chlorophyll, pH, and ORP every 2-hours for the duration of the open-water season. Data collected by the sondes is interpreted by ECC staff.
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.