Water Quality

Water Quality

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Water Quantity

Changes in water quality in some waterbodies have been observed by Indigenous communities and through scientific studies in the Peace sub-basin. Some Indigenous communities have observed an increase in contaminants and changes in the colour and smell of the water, which they associate with increased mining, forestry, and intensive agriculture. Trends in water quality parameters varied spatially, including increases in dissolved metals observed in the Wapiti, Smoky and Peace Rivers and localized decreases in phosphorus in the lower Wapiti River from treatment improvements at a municipal wastewater treatment plant and a pulp and paper mill. Although there is a lack of historic baseline information for water quality in the sub-basin, recent analyses rank water quality as “good” or “excellent” in the Peace River. Human footprint has increased over time and there are significant concerns for how water contamination from land development and settlement will continue to affect water quality and ecosystem health.

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

Signs and Signals

Indigenous Knowledge Information and Data

Indigenous Knowledge Availability

Science Information and Data

Science Data Availability

Water Quality

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

Many observations from several locations.

Ambient surface and ground water concentrations

Data available from Alberta Environment and Parks, BC Ministry of the Environment and Climate Change Strategy (EMS) and CABIN*. Analyses available in many reports.

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

Many observations from several locations.

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

Data and analyses available

Effluent Discharge

Not assigned a Sign or Signal

Not assessed.

Volume of effluent discharges

Information available

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[27].

Water Quality

An increase in contaminants in many waterbodies in the Peace sub-basin has been documented by Indigenous communities and through scientific studies, in particular the smaller rivers and streams. Water quality in larger rivers is considered good and a reversal of some impacts has been achieved through improved wastewater treatment in the pulp and paper and municipal sectors.

In a study with Treaty 8 First Nations in BC, all communities[28] noted an increase in contaminants in local waterbodies that were formerly reliable sources of drinking water, including Halfway River and Doig River. The contaminants are associated with herbicide and pesticide use by nearby mining, forestry and intensive agriculture operations as well as more frequent oil and gas spills.[29] According to the Kelly Lake Métis, water quality in Kelly Lake has deteriorated in recent years due to contamination from nearby settlements and industrial activity along its banks. Water in the lake was formerly of high quality and is now considered unsafe for drinking or swimming.[30]

A summary of scientific water quality data describes that agricultural streams in the Peace sub-basin are enriched with nutrients, an effect that increases in severity with increased agricultural intensity. Phosphorus in lakes in the watershed was considered ‘high’ (most lakes were “eutrophic”, which means high level of biological productivity, such as algae) and increased in some lakes from the 1980s to 2010. Typically, phosphorus was higher downstream of anthropogenic disturbances.[31] One example is the increased abundance of green algae and cyanobacteria in Charlie Lake, B.C. in response to agricultural activity in the watershed, as indicated by anecdotal information and sediment core studies.[32]

One of the key complaints by a number of people was the use of herbicides and pesticides in mining and forestry. Agricultural contamination from intensive farming practices was a concern heard often,

Treaty 8 First Nations and the Firelight Group, 2012
In the Peace River, many Indigenous communities have observed a decline in water quality in the past five decades, including changes in colour, smell, algal growth, and silty or muddy water, which are often linked to perceived contamination by industrial development.[33] These observations contrast the scoring of the Peace River as “Good” or “Excellent” using the Alberta Water Quality Index from 2003 to 2013, based on frequency and degree of guideline exceedances. Excellent rating indicates that guidelines are almost always met and a Good rating signifies that guidelines are occasionally exceeded but usually by small amounts and the threat to water quality is minimal.[34]

Changes in the appearance of water, such as colour and smell, in the past several decades have been reported by Indigenous communities in the Peace sub-basin.[35] The Kelly Lake Métis have observed that water in local waterbodies has an oil-like scent and combustible gas has been observed in water pipes.[36]


The Halfway River near its confluence with the Peace River. Image source: jmmcbeth via Flickr Creative Commons (copyright-free).

In the Peace River Regional District in BC, there has been an increasing presence of sodium and sulfate in surface water (after 2000), in groundwater (after 2000), and in spring water (after 2011). There has also been an observed increasing presence of chloride in surface water after 2000.[37] These trends were not observed in the Peace River above Alces River. Water Quality Objectives (WQOs) were established for the Peace and Beatton Rivers in B.C. in the 1980s to inform management of current and anticipated pressures on water quality in the Upper Peace River[38]. The WQOs were met during a water quality survey in 2006[39], but an update of these WQOs may be warranted.

The lack of information on water, both on quality and quantity prior to the 1970s, has prevented the establishment of what baseline conditions were before human activities started having a footprint. Both at the surface and in the subsurface, the Alberta Water Quality Index signifies a general worsening of water quality over time.[40]

Trend analysis conducted with two ECCC sites on the Peace River mainstem showed increasing trends in several dissolved metals, such as aluminum, chromium, selenium and uranium, for several months at Peace River at Peace Point from 2000 to 2018. For example, September dissolved selenium in the Slave River at Fitzgerald increased by 0.006 µg/L (2%) per year from 2001 to 2018 (this study). Most of these trends were observed in the open-water season and dissolved aluminum concentrations exceeded the Alberta surface water quality guideline on several occasions during spring and summer (this study). In the Smoky River, there were statistically significant increasing trends for dissolved and total selenium, dissolved uranium, dissolved boron, and dissolved lithium from 1989 to 2018. Dissolved nickel, boron and barium increased from 1989 to 2018 in the Wapiti River upstream of Grande Prairie. Most parameters with increasing trends did not exceed guidelines. An exception to that was total selenium, which exceeded the guideline for protection of aquatic life in 3% of the data points collected under ice.[41] One known source of selenium in this sub-watershed is coal mining, but further study is required to evaluate if the trend is related to human activity in the watershed.

Some total metals have decreased in Wapiti and Smoky Rivers. Flow-corrected data identified significant decreasing trends in turbidity and some total metals in the Wapiti River from 1989 to 2018 and similar declines in some total metals in the Smoky River, which may be the result of trends in suspended materials and particle-associated metals.

Trend in September dissolved selenium concentrations in Peace River at Peace Point (2001-20018). 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 µg/L per year) and % change per year are displayed on the chart.

 Phosphorus concentrations in the lower Wapiti River have declined from 1989 to 2018 by 4 ng per year (flow-corrected, full time series, n=301, p<0.001), possibly due to improved phosphorus treatment in point source discharges. Chlorophyll-a in open water, however, increased consistently throughout monitoring years by 0.2 ug/L per year (open-water, n=150, p=0.047). Dissolved phosphorus increased at the Wapiti site upstream of major point sources by 0.2 ng per year (flow corrected, full time series, n=284, p=0.041).[41]

Benthic Invertebrates

There is evidence of local impacts to benthic invertebrate communities due to point source discharges in the lower Wapiti River, but analyzed data and reports are not readily available across the remainder of the sub-basin.

Elevated nutrient levels from point source discharges into the lower Wapiti River have resulted in increased benthic invertebrate productivity and lower benthic invertebrate diversity. These effects occurred to a certain degree downstream of the wastewater treatment plant servicing Grande Prairie and were enhanced downstream of a pulp and paper mill.[42]


Land Use

Contamination of aquatic ecosystems and the ongoing loss of land are leading to changes in Indigenous land use practices in the Peace sub-basin. The human footprint of forestry and oil and gas operations in the Peace sub-basin is widespread and significant land cover modification has occurred in the agricultural areas in the upper Peace.

The contamination of aquatic ecosystems and loss of extensive parts of the land base to settlement and development are impacting Indigenous land use practices in the Peace sub-basin.[43] Members of Treaty 8 First Nations in BC and Alberta have identified the loss of access to preferred traditional use areas within the upper Peace to agriculture, forestry, and oil and gas mining. Some Treaty 8 community members also report there are widely-recognized ”avoidance zones” that they no longer use for traditional practices due to safety concerns for the presence of contaminants in the air and water.[44] In the lower Peace, members from Mikisew Cree First Nation and Athabasca Chipewyan First Nation have expressed concerns for how contaminants from nearby oil and gas plants have accumulated in the Peace-Athabasca Delta. As a result, fish and wildlife in the Delta are less healthy, which deters members from hunting and fishing.[45],[46]

Bridge over the Peace River near Taylor, BC. Image source: Jason Woodhead via Flickr Creative Commons (copyright-free).

Land cover in the Peace sub-basin is largely forested (66%) comprised primarily of temperate or sub-polar needleleaf forest, which includes areas of active forestry operations. Other land uses in the region include shrubland (13%) and cropland (8%). The sub-watersheds with the largest agricultural footprints in the Alberta portion of the sub-basin are the upper Peace (37%) and Smoky Wapiti (17%).[47]


% Land Cover

















Land Cover Type

Area 1990 (km2)
Area 2010 (km2)
Change (km2)

% change

1990 % cover

2010 % cover






















Forest/Trees + Forest/Treed wetland



































The total area of human footprint in the Lower Peace Region increased by 3.0 percentage points, from 5.6% in 1999 to 8.6% in 2017. This increase was driven by the expansion of forestry footprint, which more than doubled in size during this time from 1.5% to 3.6%. However, the increase in forestry footprint is lower (1.8%, from 0.8% to 2.6%) when recovery of regenerating forest is included. The remaining human footprint categories each had small increases of < 1.0 percentage point between 1999-2017.

The total area of human footprint in the Upper Peace Region increased by 7.1 percentage points, from 27.3% to 34.4%. This increase was driven by the expansion of forestry footprint, which more than doubled in size during this time from 4.7% to 10.2%. However, this increase in forestry footprint is lower (4.9%, from 2.8% to 7.7%) when recovery of regenerating forest is included. The remaining human footprint categories each had small increases, < 1.0 percentage point between 1999-2017, with energy footprint showing the next largest increase from 1.3% to 2.0%.

Trend in the percentage area of total human footprint, and by human footprint category in the Upper (left panel) and Lower (right panel) Peace Regions between 1999 and 2017. Reproduced with permission from Alberta Biodiversity Monitoring Institute.


Effluent Discharges

Water quality in tributaries of the Peace River and smaller streams in the sub-basin is locally and regionally impacted by effluent discharges, but there have been improvements in wastewater treatment.

There are 11 major sources of effluent in the Peace sub-basin. These include mill and municipal effluent into the Wapiti River, municipal and industrial surface runoff into the Smoky River, mill, municipal and oil and gas industrial process effluent into the Peace River and municipal effluent into the Notikewin River and North Wabasca Lake.

The Grande Prairie wastewater facility is the only tertiary wastewater treatment plant in the sub-basin. The remainder are secondary or primary treatment.[49]

Historically there have been water quality issues in the Peace sub-basin due to industrial and wastewater effluents. Biological Oxygen Demand loadings, however, decreased from 9,700 kg/day to 3,800 kg/day from 1990 to 2001.[50] Studies have shown that water quality downstream of pulp mill effluents has improved following implementation of the Canadian Pulp and Paper Effluent Regulations in 1992.[51] Municipal wastewater treatment plants also have recently implemented improved treatment processes, such as Grande Prairie in 2013-2015.[52]

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