Water Quality

Water Quality

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Water Quantity

Localized changes in water quality have been observed by some Indigenous communities and linked to land development and potential contamination. Monitoring data have shown little change. Trend analyses show that ionic strength in the Liard River has increased in the past 20 years, while some metals concentrations have decreased.

The following table summarizes the availability of information for each Water Quality indicator.

Signs and Signals

Indigenous Knowledge Information and Data

Indigenous Knowledge Availability in Public Sources1

Science Information and Data

Science Data Availability2

Water Quality

Local observations and oral histories of good water, poor water, seasonal differences, land-based consumption practices

Some observations from few locations.

Ambient surface and ground water concentrations

Data available from BC Ministry of the Environment (EMS), from NWT CBM Program, two ECCC sites analyzed for trends, few recent reports found.

Benthic Invertebrates

Not assigned a Sign or Signal

Not assessed.

Relative abundance of aquatic macroinvertebrates

Data available from CABIN* but no analysis conducted. Limited reports found.

Land Use Changes

Stories and oral histories of land use cover and practices

Some observations from few locations.

Map and statistics of current vs. past land cover and land use

Land Cover data available, but no data on changes

Effluent Discharge

Not assigned a Sign or Signal

Not assessed.

Volume of effluent discharges

Data available on Yukon Governments :”Waterline” website, Mackenzie Valley Water Board public registry, BC Ministry of the Environment (EMS), but not summarized

1 Qualifiers for the availability of local and Indigenous Knowledge observations in publicly available sources: Limited = 1-2 observations; Some = 3-4 observations; Many = 5 or more observations
2 Qualifiers for the availability of science data in publicly available sources: Low = Individual studies or locations; Many = Network of monitoring stations across the basin

*CABIN = Canadian aquatic biomonitoring network[14].

Water Quality

Indigenous communities are concerned about water contamination in some parts of the Liard sub-basin. There was potential evidence of local water quality impacts of upstream oil and gas activity in small watersheds during freshet in a study of the Horn River Basin. Some monitoring in the Liard River mainstem indicated increasing concentrations in ions, but these were not of concern for aquatic life.

Some Indigenous communities in the Liard sub-basin have observed an increase in contaminants in local water sources. Fort Nelson First Nation members avoid collecting drinking water from specific lakes and rivers, citing concerns for contamination from nearby industrial activity.[15] Findings of a survey conducted with members of Liard First Nation found that members had concerns for source water contamination, particularly from garbage dumps. Respondents also expressed concern for the recent effects of mine tailings, heavy metals,

Dissatisfaction with drinking water quality strongly relates to source water contamination concerns, shared by more than half of respondents [members of Liard First Nation], with garbage dumping as the primary concern,

Christensen, 2015
pesticides, and bacteria on source water quality in the Watson Lake area and flooding events in the upper Liard watershed in 2012.[16] Focused spatial sampling at microbasin drainage outlets in the Petitot River near oil and gas development from 2012 to 2015 show no indication of upstream contaminants in the mainstem of the Petitot River. Smaller watersheds showed some potential effects of upstream oil and gas activity, especially barium, which showed a relationship during freshet with variables associated with drill waste. Trace organic analyses showed undetectable or low background concentrations for all measured analytest.[17]

Samples collected from 2012-2016 by the GNWT Community Based Monitoring Program showed that several parameters exceeded CCME guidelines for the protection of aquatic life[18] in the Liard River near the mouth, including total aluminum, iron, lead and copper.  These exceedances were associated with the naturally occurring suspended sediments in the river, as indicated by the occurrence of exceedances at sites with elevated TSS levels. Hydrocarbons varied throughout the years but remained well below values that could affect aquatic life.[19]

Liard River at Allen’s Lookout, BC. Image source: Susan Drury via Flickr Creative Commons (copyright-free).

Two main water quality trend patterns were found in data collected by Environment and Climate Change Canada in the Liard River at Fort Liard and near the mouth, i.e., upstream of the confluence with the Mackenzie River, between 2000 and 2018. Parameters associated with ionic strength, such as hardness, total dissolved solids, conductivity and sulphate and nitrogen compounds showed increasing trends at both sites, but only in monthly datasets between January and September. For example, June specific conductance concentrations in the Liard River at Ford Liard increased by 6.8 µS.cm (3.5%) per year during that time (this study). None of the parameters have a CCME guideline for the protection of aquatic life, but sulphate does in BC[20], and remained well below that provincial guideline of 128 mg/L, with values mostly around 50 mg/L (this study). Similar increasing trends were found in 5 years of data from the NWT community-based monitoring program in Liard River near the mouth.[21] Decreasing trends in total and dissolved vanadium, total and dissolved zinc, total cadmium and total aluminum were found at both sites as well while decreasing trends in total arsenic were only found near the mouth (this study). Data collected in the 1990s in the Liard River indicated that water quality was good with no water quality trends or concerns at that time.[22]  Routine monitoring in the Petitot River from 2012 to 2015 resulted in similar conclusions.[23]

Trend in June specific conductance in Liard River at Fort Liard (2000-20018). Data from Environment and Climate Change Canada. Significance and slope of the trend were estimated using the Mann Kendall Trend Test. The Sen Slope (change in µS/cm per year) and % change per year are displayed on the chart.

Benthic Invertebrates

Analyzed information on benthic invertebrates was limited in the Liard sub-basin; available raw data were not analyzed.

Benthic invertebrate monitoring was conducted from 2012 to 2015 to establish baseline reference conditions for benthic macroinvertebrate communities, and develop a predictive bioassessment model to assess the ecosystem health of streams in the Liard, Fort Nelson, and Petitot River basins. Nearly two thirds of benthic data collected at thirty-five test sites near oil and gas activity were different from reference conditions, but community response was not correlated with geospatial stressor variables related oil and gas development. Overall, the study period was too short to identify the underlying causes.[24]

Land Use

Contamination of aquatic ecosystems and resource development are leading to changes in Indigenous land use practices in the Liard sub-basin. Conversely, available land cover data show negligible human footprint.

The potential for contamination of aquatic ecosystems and downstream effects of resource development activities are impacting Indigenous land use practices in the Liard sub-basin.[25] Fort Nelson First Nation has identified concerns with the risks of contamination to water and wildlife from hydraulic fracturing, which has become the main industry in their traditional territory in the past 10-15 years.[26] Suspected contamination of the land and water from hydraulic fracturing, mining and other industrial developments deters Fort Nelson First Nation members from engaging in traditional practices like hunting and fishing.[27] Members of Liard First Nation and the Kaska Dena have similarly observed the persistent and intensifying effects of industrial activity in the middle

Mining continues to be a catalyst for change in the land, altering water ways, disrupting fisheries and animal migration, and raising concerns about food contaminants [in Kaska Dena territory],

Johnson, 2012
and upper Liard watersheds, particularly mining near Watson Lake and Ross River. Members from both communities have witnessed the effects of contaminants to local water, fish and wildlife, including poor water quality and fish and wildlife with an unhealthy appearance. As a result, many members of the Liard First Nation and Kaska Dena indicate they are less willing to engage in traditional land use pursuits.[28],[29]


Research conducted by the Liard First Nation assessed the water quality of 40 private drinking water wells. The results indicated the water quality of these wells was good overall. A few of the wells showed very low levels of the chemical Tributylin, but levels were below the World Health Organization’s guidelines for acceptable levels. No compounds related to the landfill, cemetery, military wastes, oil pipes or septic systems were found in the wells and the project results suggest the Liard First Nation residents do not need to worry about the quality of their tap water.

Land cover in the Liard sub-basin is dominated by forest (69%) which is primarily comprised of temperate or sub-polar needleleaf forest. 11% of land cover is shrubland and 9% is barren.


% Land Cover

















Map of land cover in the Liard sub-basin (2015)

There is limited forest harvest activity in the southwest and southern portions of the Liard sub-basin, as much of the timber is not ideal for harvest. The southern region of the Liard has seen metallic mineral exploration, but as of 2008 there were no mines in operation. The Prairie Creek Mine in the South Nahanni River watershed is planned to start operations in the near future, with an all-season access road already approved.[30] Oil and gas exploration and operations, including hydraulic fracturing, have also increased towards the eastern regions of the Liard sub-basin and are prevalent in the region around and north of Fort Nelson.[31]

Effluent Discharges

The volume of effluent discharges by municipalities into lakes and rivers in the Liard sub-basin remains minor.

Municipalities that discharge municipal wastewater into the receiving environment in the Liard sub-basin are Fort Nelson, Fort Liard and Watson Lake.

Hydraulic fracturing wastewater is not discharged to surface water environments, instead it is injected into produced water disposal wells.[32]

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