Water quality in Canadian rivers

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Along the east coast of Canada, all rivers drain into the Atlantic Ocean. This region includes Nova Scotia, New Brunswick, Prince Edward Island, Newfoundland and Labrador, along with part of eastern Quebec.

Key results

For the 2020 to 2022 period:

• most sites in the Atlantic Ocean region:
  • are in areas with forestry or in undeveloped areas
  • have fair to good water quality
• monitoring sites in high population density areas and with agriculture or forestry (mixed pressures) usually have worse water quality

For the 2002 to 2022 trend period:

• nearly half of the sites (46%) had a water quality deteriorating trend
• there was no change in water quality trend for 42% of sites
• only 11% of sites has improved their water quality

Water quality by land use category, Atlantic Ocean region, 2020 to 2022 period

Navigate data using the interactive map
How is this indicator calculated

Note: Water quality was assessed at 46 sites on rivers draining into the Atlantic Ocean using the Canadian Council of Ministers of the Environment's water quality index. For more information on land use classification, consult the Data sources and methods section.
Source: Water quality data were assembled by Environment and Climate Change Canada from existing federal, provincial and joint water quality monitoring programs. Population, forestry, mining and land cover statistics for each site's drainage area were provided by Statistics Canada, Natural Resources Canada, Environment and Climate Change Canada, Agriculture and Agri-Food Canada, the Government of Alberta and the University of Maryland.

Rivers in this region drain into the Great Lakes and the St. Lawrence River. It includes western Quebec, southern Ontario and the section of northern Ontario that boarders Lake Superior.

Key results

For the 2020 to 2022 period:

• water quality in rivers in the Great Lakes and St. Lawrence River region is generally:
  • fair to poor in southwestern Ontario and along the St. Lawrence River between Montreal and Quebec City
  • good in eastern Ontario
• monitoring sites in areas where there are mixed pressures tend to have worse water quality

For the 2002 to 2022 trend period:

• water quality has deteriorated at 67% of all sites
• the rest of the sites (33%) showed no change (stable)

Figure 5. Water quality by land use category, Great Lakes and St. Lawrence River region, 2020 to 2022 period

Navigate data using the interactive map
How is this indicator calculated

Note: Water quality was assessed at 49 sites on rivers draining into the Great Lakes or St. Lawrence River using the Canadian Council of Ministers of the Environment's water quality index. For more information on land use classification, consult the Data sources and methods section.
Source: Water quality data were assembled by Environment and Climate Change Canada from existing federal, provincial and joint water quality monitoring programs. Population, forestry, mining and land cover statistics for each site's drainage area were provided by Statistics Canada, Natural Resources Canada, Environment and Climate Change Canada, Agriculture and Agri-Food Canada, the Government of Alberta and the University of Maryland.

The Nelson River, the largest in this region, originates at the northern tip of Lake Winnipeg and flows into the south-western corner of the Hudson Bay. Its tributaries drain over 1 million km² of land starting in the Rocky Mountains running through the Prairies and into Lake Winnipeg. This region covers most of Manitoba, Saskatchewan, the southern half of Alberta and parts of northwestern Ontario.

Key results

For the 2020 to 2022 period:

• water quality in rivers close to the Rocky Mountains, in Saskatchewan, and north of Lake Winnipeg in the Hudson Bay region tends to be good or excellent
• water quality is rated fair to marginal in areas where there is agriculture, or a mixture of agriculture and mining

For the 2002 to 2022 trend period:

• very few sites (7%) showed a deteriorating trend
• 20% of sites show improvement while 73% of sites have stable trend

Water quality by land use category, Hudson Bay region, 2020 to 2022 period

Navigate data using the interactive map
How is this indicator calculated

Note: Water quality was assessed at 44 sites on rivers draining into the Hudson Bay using the Canadian Council of Ministers of the Environment's water quality index. For more information on land use classification, consult the Data sources and methods section.
Source: Water quality data were assembled by Environment and Climate Change Canada from existing federal, provincial and joint water quality monitoring programs. Population, forestry, mining and land cover statistics for each site's drainage area were provided by Statistics Canada, Natural Resources Canada, Environment and Climate Change Canada, Agriculture and Agri-Food Canada, the Government of Alberta and the University of Maryland.

The Mackenzie River watershed is the largest in Canada, covering nearly 20% of the country and is one of the least developed. Its 2 largest tributaries, the Peace River and the Athabasca River, drain much of north-central Alberta and the Rocky Mountains in northern British Columbia.

Key results

For the 2020 to 2022 period:

• water quality in the Mackenzie River region is generally good to excellent in areas where there is little development
• water quality tends to be lower where there are multiple pressures, such as agriculture, mining and forestry

For the 2002 to 2022 trend period:

• there were 2 sites with stable trends and 2 sites with deteriorating trends

Water quality by land use category, Mackenzie River region, 2020 to 2022 period

Navigate data using the interactive map
How is this indicator calculated

Note: Water quality was assessed at 18 sites on rivers draining into the Mackenzie River using the Canadian Council of Ministers of the Environment's water quality index. For more information on land use classification, consult the Data sources and methods section.
Source: Water quality data were assembled by Environment and Climate Change Canada from existing federal, provincial, territorial and joint water quality monitoring programs. Population, forestry, mining and land cover statistics for each site's drainage area were provided by Statistics Canada, Natural Resources Canada, Environment and Climate Change Canada, Agriculture and Agri-Food Canada, the Government of Alberta and the University of Maryland.

Along the west coast of Canada, rivers draining into the Pacific Ocean flow through varied landscapes, from large areas with little development to one of Canada's largest cities: Vancouver.

Key results

For the 2020 to 2022 period:

• water quality in the Pacific Ocean region is generally fair to good
• marginal or poor water quality is found where there is mining or a combination of mining, forestry activities and high population density

For the 2002 to 2022 trend period:

• of 20 sites monitored, 8 had a stable trend in water quality
• water quality at 4 sites has improved and it has deteriorated at 6 sites

Water quality by land use category, Pacific Ocean region, 2020 to 2022 period

Navigate data using the interactive map
How is this indicator calculated

Note: Water quality was assessed at 20 sites on rivers draining into the Pacific Ocean using the Canadian Council of Ministers of the Environment's water quality index. For more information on land use classification, consult the Data sources and methods section.
Source: Water quality data were assembled by Environment and Climate Change Canada from existing federal, provincial, territorial and joint water quality monitoring programs. Population, forestry, mining and land cover statistics for each site's drainage area were provided by Statistics Canada, Natural Resources Canada, Environment and Climate Change Canada, Agriculture and Agri-Food Canada, the Government of Alberta and the University of Maryland.

For the 2020 to 2022 period, water quality data from 163 sites were used to compile the national indicator. These data were drawn from monitoring sites in Canada's 16 southernmost drainage regions. The 16 regions were selected based on population and land use to create the water quality indicator core network for national water quality reporting.

Geographic extent of the 16 drainage regions selected for the national water quality indicator

The regional indicator groups these 16 drainage regions to 5 larger drainage regions, based on the water body in which rivers ultimately drain into:

• Atlantic Ocean region (22, 23, 24, 25)
• Great Lakes and St. Lawrence River region (19, 20, 21)
• Hudson Bay region (10, 11, 12, 13, 14, 15)
• Mackenzie River region (6, 7)
• Pacific Ocean region (1, 2, 3, 4, 5)

Parts of the Mackenzie River region fall outside of the 16 drainage regions (Figure 9). In order to ensure proper coverage of this region in the regional indicator, 14 additional sites were considered: 4 sites in Alberta, 1 site in Saskatchewan and 9 sites in the Northwest Territories. These additional sites were not included in the national indicator nor the trend analysis. In the Atlantic Ocean region, the North Shore-Gaspé drainage region is not included in the Freshwater Quality Monitoring and Surveillance program.

Water quality is evaluated at an additional 152 monitoring sites across Canada. However, these additional sites are not included in the calculations because they do not meet the minimum data requirements detailed in the section below, or because including them would over represent the region. Although water quality results for all 315 sites can be explored using the interactive water quality map. 

Data used to calculate the indicator includes a selection from a total of around 40 water quality parameters, such as major ions, physical parameters, trace metals, nutrients and pesticides, as well as pH, temperature and hardness, required to calculate certain guidelines. Sample timing and frequency are set by monitoring programs and vary among sites.

Each data record is tagged with the site name, the date the sample was collected, the name and the chemical form of the parameter. Land use and ecological information are also collected for each site. Water quality data, along with water quality indicator scores and site information from the monitoring programs, are stored in a central water quality indicator dictionary housed within a larger database at Environment and Climate Change Canada.

Land use characterization for all monitoring sites was updated in 2019. Land use at each site was determined using:

• population density from Statistics Canada, Population 2016 by dissemination block level
• mine locations using Natural Resources Canada's 2018 Map 900A: Principal Mineral Areas, Producing Mines, and Oil and Gas fields in Canada, Sixty-Eight Edition
• advanced mineral projects locations using Natural Resources Canada’s Advances mineral projects inventory released in February 2019
• oil sands locations using data provided by Alberta Energy, Government of Alberta 2011
• pulp and paper locations using the Environment and Climate Change Canada's National Pollutant Release Inventory (NPRI): Geographic Distribution of NPRI-Reporting Facilities
• forest loss estimated by time-series analysis of 654 178 Landsat 7 ETM+ images in characterizing global forest extent and change from Global Forest Change 2000 to 2012
• agricultural activity locations using Natural Resources Canada's Land Cover 2010, Cropland class
• estimation of livestock using the "Agri-Environmental Indicator (AEI): Livestock Emissions from Agriculture" dataset estimating net emissions produced by livestock from Soil Landscapes of Canada agricultural areas for census years from 1981 to 2011
• land cover using Natural Resources Canada's Land Cover 2010

Data quality assurance and quality control

Data quality assurance/quality control is performed by the monitoring program providing data for the water quality indicators. Each monitoring program follows standardized methods for sample collection in the field. Chemical analyses are performed in Canadian laboratories accredited by the Canadian Association for Laboratory Accreditation or the Standards Council of Canada.

Environment and Climate Change Canada performs further quality assurance/quality control to ensure datasets meet minimum data requirements for the analysis and that calculation standards are respected. This process verifies the number of samples, sample timing, location of monitoring sites and calculations. It can lead to the removal of water quality data due to low sampling frequencies, erroneous measurements or where analytical detection limits are higher than the guidelines used in the calculation. Unusually high or low values in the monitoring datasets are double-checked and confirmed through consultation with the data provider.

Minimum data requirements

Calculating the water quality status for most sites requires a minimum of 4 samples per year collected over 3 years. A minimum of 3 samples per year is permitted for northern and remote sites, as access during winter months can be difficult, dangerous and costly. A sensitivity analysis found that there was no significant difference in the water quality index score when mid-winter samples were excluded.^{Footnote 12} Footnote

COVID-19 impact on the calculation of the indicators

Due to health measures related to the COVID-19 pandemic, some sampling activities and laboratory analysis were cancelled in 2020. The method for calculating the water quality status for the 2020-2022 period was adjusted to account for this lack of available data at some sites. Therefore, the scores reported were calculated using 2021 and 2022 data, as well as 2020 data when they were available (totally or partially). Where 2020 data were unavailable, the scores were calculated using 2021 and 2022 data only. Because of this, the comparison of results, between years and stations, should be interpreted as indicative.

Parameter selection

Federal, provincial and territorial water quality experts select the parameters to be assessed at each site based on their knowledge of local water quality stressors. Selected parameters typically include at least one form of the following parameter groups: nutrients (for example, phosphorus, nitrate, nitrite, total nitrogen), metals (for example, zinc, copper, lead), and physico-chemical parameters (for example, pH, turbidity), as well as 2 to 4 regionally-specific parameters (for example, chloride, ammonia, dissolved oxygen, pesticides). The water quality index score is based on these selected parameters.

Water quality guideline selection

Water quality guidelines for the protection of aquatic life are recommended limits or statements for a variety of chemical substances and physical parameters, which, if exceeded, may impair aquatic life. These guidelines are based on existing knowledge of a substance's environmental fate, behaviour and chronic or, in a few cases, acute toxicity.

Federal, provincial or territorial water quality experts select the guidelines to use in the calculation of the water quality indicator based on their local relevance. The Canadian Freshwater Quality Guidelines for the Protection of Aquatic Life are recommended if locally relevant. Annex B provides a complete list of guidelines used by provinces and territories and their source.

Background concentrations of naturally-occurring substances and other local river characteristics can impact the measured concentration and toxicity of some substances. In these cases, site-specific guidelines may be developed using procedures based on background concentrations^{Footnote 15}  or a rapid assessment approach. The rapid assessment approach uses long-term monitoring data and adjusts for natural events, such as high flows, that may influence results. ^{Footnote 16}   Footnote

Selection of national core sites for the development of the national indicator

Among Canada's 25 drainage regions (Figure 9), 16 were selected based on population and land use to create the water quality indicator core network for national water quality reporting. Within the 16 selected drainage regions, core sites were selected to ensure site drainage areas do not overlap and are independent of one another. The upstream drainage area of each monitoring site was delineated by Statistics Canada using the National Hydro Network.^{Footnote 17}  Where the upstream drainage areas of monitoring sites overlapped, the site furthest downstream was retained for the core network, as the downstream site is impacted by the maximum area in the river basin and, to some degree, reflects the cumulative impact of all upstream stresses. For 14 large rivers, core sites were chosen in the upper, mid and lower portions of the main river and at the most downstream sites on each tributary, when available. Additional core sites were included on these rivers, because water travels thousands of kilometres from the source to the mouth of these rivers. Water quality changes along the way and cannot be summarized by a unique downstream monitoring site. The final selection of core sites ensures monitoring sites are well distributed among provinces and drainage regions.

The number of core sites changes from year to year due to samples being missed or lost, which can lead to the site not having the minimum data required to be reported.

Classification of sites

Land use was assessed in the drainage area of core sites and classified according to the criteria presented in Table 1 using the drainage area of each monitoring site.^{Footnote 18}  Even if a site’s land use classification is Agriculture, Forestry, Mining or Populated, it does not mean that these are the only activities taking place at that site. These land use classifications were determined to be the most representative of the environmental pressures on each site's drainage area based on the data available at the time the analysis was done.

Note: ^[A]Either criteria must be met. ^[B]Livestock intensity was calculated by dividing the total estimated emissions of greenhouse gas by the basin area. The lower value was attributed an intensity value of 0 and the highest value, an intensity value of 1. ^[C]Mines includes metal mines and mills, non-metal mines, quarries, coal mines, and oil sands mines.

Calculating water quality status

The water quality indicators are calculated using the water quality index, as endorsed by the Canadian Council of Ministers of the Environment. The water quality index calculation considers 3 factors to summarize water quality at a site: scope, frequency and amplitude (Equation 1).

• Scope (F₁) is the percentage of parameters for which the water quality guidelines are not met.
• Frequency (F₂) is the percentage of samples for which the water quality guidelines are not met.
• Amplitude (F₃) refers to the amount by which the water quality guidelines are not met.

The score is normalized to yield a score between 1 and 100. The full set of equations for the water quality index is described in the Canadian Council of Ministers of the Environment (2017) CCME Water Quality Index 2.0 User’s Manual (PDF; 1.60 MB).

Equation 1.

Water quality scores are grouped into 5 categories following the Canadian Council of Ministers of the Environment's water quality index (Table 2).

Except where 2020 data was not available, 3 years of data are used to calculate the indicator. This is to dampen temporal variability in the results caused by annual fluctuations in weather and hydrology, to make the water quality indicators more representative of how humans are impacting water quality in rivers.^{Footnote 19} 

Calculation of trends in the water quality

The water quality index formulation can only detect change once parameter values exceed their guidelines, making it a metric that is much less sensitive to change over time. In order to increase trend detection sensitivity, a separate set of calculations and metrics were carried out. This trend analysis allows for the detection of improving or deteriorating trends in water quality status at a site, whether they occur above or below guideline values.

For each year a guideline deviation ratio was calculated by dividing each parameter concentration by its guideline value for each sampling date. The logarithm of the ratios was calculated and averaged for each year to produce a mean annual value (Equation 2). The ratios were multiplied by -1 to invert the values so that improving water quality will show a positive slope to match how water quality is portrayed with the water quality index. 

Equation 2.

For each year:

where,

i = parameters

j = samples

n = total number of samples

p = total number of parameters

C = measured concentration

G = guideline value

T = total number of samples per year

As the parameter concentrations get closer to their guidelines, the guideline deviation ratio gets closer to zero. A guideline deviation ratio below zero means the parameter concentrations are above their recommended guidelines. When parameter concentrations are well below the guidelines, the ratio is above 1.

3 parameters were exceptions:

• Dissolved oxygen and total alkalinity have guidelines for which measurements must be above, rather than below like the majority of parameters. The ratio for dissolved oxygen was calculated by dividing the guideline by the concentration.
• pH measurements must lie within a range of generally 6.5 and 9. The ratio for pH values less than 6.5 was calculated by dividing the lower guideline (6.5) by the concentration (measured pH). For pH values greater than 9, the ratio was calculated by dividing the concentration by the upper guideline (9).
• Where temperature was used as a parameter, the negative value was replaced by zero.

Current parameters and guidelines at each site were used through the entire record to avoid mistaking methodological changes in the water quality indicator for water quality change. When historical data were missing for a parameter, the parameter was dropped from the trend analysis. Where there was a change in the analytical form of a parameter, and there was no way of converting to the new form, the old dataset was used.

A Mann-Kendall test using the zyp (version 0.10-1.1, 2019) and Kendall packages (version 2.2, 2011) of the statistical software R (version 3.5.2, 2018) was used to detect the presence of statistically-significant trends in the guideline deviation ratios. A count of sites with increasing, declining and no trends in the water quality indicator was compiled for the indicator of change through time, from 2002 (or after 2002 for certain sites) to 2022.

Water quality guidelines are derived from laboratory studies that do not consider, among other things, the impact of flow on sediment loads in a river. Although site-specific guidelines try to take into account the impact of elevated flows on parameter concentrations, elevated levels of naturally-occurring substances, such as minerals, nutrients, glacier deposits and soils, can lower water quality ratings.

The water quality indicators do not directly measure biological integrity; it measures whether physical and chemical characteristics of freshwater bodies are acceptable for aquatic life. Although physical and chemical measurements provide good proxies for biological integrity, only biological information provides a direct measurement of conditions for aquatic life.

The water quality indicators only assess the quality of surface waters. Groundwater is not considered in these indicators.

It can be difficult to compare water quality index scores among sites due to flexibility in the selection of parameters and guidelines to reflect local and regional water quality concerns. The water quality categories assigned based on the scores, however, are comparable. A site classified as marginal has water quality guidelines that are being exceeded frequently and/or by a considerable margin, even if the parameters and guidelines used to make that classification are not exactly the same at all sites.

Only parameters for which water quality guidelines exist can be included in the indicators. The absence of a water quality guideline for a parameter does not mean the parameter is unimportant.

The water quality indicator scores are sensitive to the number of parameters and samples used in their calculation. The number of parameters used in the indicators varies from 5 to 15 depending on the monitoring site, and between 9 and 36 samples can be used for a given parameter. In general, as the number of parameters, or samples, used to calculate the index increases, the score decreases because there is a greater chance of a guideline exceedance.^{Footnote 20}    

Water quality varies naturally with weather and hydrological cycles. Although the Water quality in Canadian rivers indicators use a 3-year average to dampen the influence of specific rain fall and snow melt events on the water quality scores, care must be taken in comparing one period to another.

Note: n/a = not applicable.
^[A] Applies to sites monitored under provincial monitoring programs.
^[B] Applies to sites monitored under federal monitoring programs, including the Prairie Provinces Water Board.
SSG denotes that different site-specific guidelines or formulas were used at sites. Specific site information is available upon request.

Alberta water quality guideline sources:

1. Canadian Council of Ministers of the Environment (2023) Canadian Water Quality Guidelines for the Protection of Aquatic Life. Summary Table. Retrieved on December 20, 2023. 
2. United States Environmental Protection Agency (2001) 2001 Update of Ambient Water Quality Criteria for Cadmium. Document EPA 822-R-01-001. Retrieved on December 20, 2023. 
3. Alberta Environment (2018) Environmental Quality Guidelines for Alberta Surface Waters (PDF; 704 kB). Retrieved on December 20, 2023. 
4. Government of Canada (2008) Technical Guidance Document for Water Quality Index Practitioners Reporting Under the Canadian Environmental Sustainability Indicators (CESI) Initiative 2008. Environment and Climate Change Canada and Statistics Canada. Retrieved on December 20, 2023. 
5. Prairie Provinces Water Board (1992) Master Agreement on Apportionment. Schedule E: Agreement on Water Quality. Retrieved on December 20, 2023. 

Note: n/a = not applicable.
SSG denotes that different site-specific guidelines or formulas were used at sites. For details on the derivation of site-specific guidelines, consult BCMOE (1997).

British Columbia water quality guideline sources:

1. British Columbia Ministry of Environment (2021) British Columbia Working Water Quality Guidelines: Aquatic Life, Wildlife & Agriculture . (PDF; 745 kB) Retrieved on December 20, 2023.
2. Canadian Council of Ministers of the Environment (2023) Canadian Water Quality Guidelines for the Protection of Aquatic Life Summary Table. Retrieved on December 20, 2023.
3. Butcher, GA. (1992) Lower Columbia River, Hugh Keeleyside dam to Birchbank water quality assessment and objectives: Technical appendix (PDF; 9.9 MB). British Columbia Ministry of the Environment, Lands and Parks. Retrieved on December 20, 2023.
4. British Columbia Ministry of Environment and Climate Change Strategy (2000) Ambient Water Quality Assessment and Objectives for the Lower Columbia River Birchbank to the US border (PDF; 231 kB). Retrieved on December 20, 2023.
5. Environment and Climate Change Canada (2005) Site-specific Water Quality Guidelines for the Liard River at Upper Crossing for the Purpose of National Reporting. Tri-Star Environmental Consulting.
6. Environment and Climate Change Canada (2005) Site-specific Water Quality Guidelines for the Skeena River at Usk for the Purpose of National Reporting. Tri-Star Environmental Consulting.
7. Environment and Climate Change Canada (2005) Site-specific Water Quality Guidelines for the Kootenay River at Kootenay Crossing for the Purpose of National Reporting. Tri-Star Environmental Consulting.
8. British Columbia Ministry of Environment (2019) Copper Water Quality Guideline for the Protection of Marine Aquatic Life (PDF; 592 kB). Retrieved on December 20, 2023.
9. Government of Canada (2013) Technical Guidance Document for Water Quality Index Practitioners Reporting Under the Canadian Environmental Sustainability Indicators (CESI) Initiative 2008. Environment and Climate Change Canada and Statistics Canada. Retrieved on December 20, 2023.
10. Obee, N. (2011) Water Quality Assessment and Objectives for the Cowichan and Koksilah Rivers: First Update. British Columbia Ministry of Environment, Environmental Protection Division and Environmental Sustainability and Strategic Policy Division. Victoria, BC. (PDF; 4.64 MB). Retrieved on December 20, 2023.
11. British Columbia Ministry of Environment and Climate Change Strategy (2023) British Columbia Approved Water Quality Guidelines: Aquatic Life, Wildlife & Agriculture Summary Report (PDF; 1.13 MB). Retrieved on December 20, 2023.
12. Swain, LG. (1990) Ambient Water Quality Objectives for the Similkameen River Okanagan Area Overview Report. British Columbia Ministry of Environment. Retrieved on December 20, 2023.
13. Nordin, RN. and Pommen, LW. (2009) Water Quality Criteria for Nitrogen (Nitrate, Nitrite, and Ammonia): Overview Report. British Columbia Ministry of Environment (PDF; 565 kB). Retrieved on December 20, 2023.
14. British Columbia Ministry of Water, Land and Air Protection (1998) Water Quality Assessment and Recommended Objectives for the Salmon River (PDF; 275 kB). Retrieved on December 20, 2023.
15. Swain, LG. (1987) Takla-Nechako Areas, Nechako River Water Quality Assessment and Objectives. British Columbia Ministry of Environment and Parks. (PDF; 1.15 MB) Retrieved on December 20, 2023.
16. Environment and Climate Change Canada (2005) Site-specific Water Quality Guidelines for the Sumas River at the International Boundary for the Purpose of National Reporting. Tri-Star Environmental Consulting.
17. Ontario Ministry of the Environment and Energy (1994) Water Management Policies, Guidelines, Provincial Water Quality Objectives. Retrieved on December 20, 2023.
18. British Columbia Ministry of Environment (2001) Water Quality Guidelines for Temperature: Overview Report (PDF; 221 kB). Retrieved on December 20, 2023.

Note: n/a = not applicable.
^[A] Applies to sites monitored under provincial monitoring programs.
^[B] Applies to sites monitored under federal monitoring programs (Prairie Provinces Water Board).
SSG denotes that different site-specific guidelines or formulas were used at sites. Specific site information is available upon request.

Manitoba water quality guideline sources:

1. Canadian Council of Ministers of the Environment (2018) Canadian Water Quality Guidelines for the Protection of Aquatic Life. Summary Table. Retrieved on December 20, 2023.
2. Manitoba Water Stewardship (2011) Manitoba Water Quality Standards, Objectives, and Guidelines (PDF; 912 kB). Retrieved on December 20, 2023.
3. United States Environmental Protection Agency (1999) Update of Ambient Water Quality Criteria for Ammonia. Document EPA 822-R-99-014. Retrieved on December 20, 2023.
4. Government of Canada (2008) Technical Guidance Document for Water Quality Index Practitioners Reporting Under the Canadian Environmental Sustainability Indicators (CESI) Initiative 2008. Environment and Climate Change Canada and Statistics Canada. Retrieved on December 20, 2023.
5. United States Environmental Protection Agency (2023) National Recommended Water Quality Criteria – Aquatic Life Criteria Table. Retrieved on December 20, 2023.
6. United States Environmental Protection Agency (2001) 2001 Update of Ambient Water Quality Criteria for Cadmium. Document EPA 822-R-01-001 (PDF; 10.7 MB). Retrieved on December 20, 2023.
7. Prairie Provinces Water Board (1992) Master Agreement on Apportionment. Schedule E: Agreement on Water Quality. Retrieved on December 20, 2023.

Note: n/a = not applicable.
^[A] In New Brunswick, the CCME guideline recommended by Environment and Climate Change Canada is adjusted to address the ammonia form measured by the provincial laboratories, which differs from the form used by the CCME.

New Brunswick water quality guideline sources:

1. Government of Canada (2008) Technical Guidance Document for Water Quality Index Practitioners Reporting Under the Canadian Environmental Sustainability Indicators (CESI) Initiative 2008. Environment and Climate Change Canada and Statistics Canada. Retrieved on December 20, 2023.
2. Canadian Council of Ministers of the Environment (2018) Canadian Water Quality Guidelines for the Protection of Aquatic Life. Summary Table. Retrieved on December 20, 2023.

Note: n/a = not applicable.
SSG denotes that different site-specific guidelines or formulas were used at sites. Specific site information is available upon request.

Newfoundland and Labrador water quality guideline sources:

1. Canadian Council of Ministers of the Environment (2018) Canadian Water Quality Guidelines for the Protection of Aquatic Life Summary Table. Retrieved on December 20, 2023.
2. Government of Canada (2008) Technical Guidance Document for Water Quality Index Practitioners Reporting Under the Canadian Environmental Sustainability Indicators (CESI) Initiative 2008. Environment and Climate Change Canada and Statistics Canada. December 20, 2023.
3. Khan, AA. et al. (2005) Application of CCME Procedures for Deriving Site-specific Water Quality Guidelines for the CCME Water Quality Index (PDF; 288 kB). Water Quality Research Journal 40(4):448-456. Retrieved on December 20, 2023.

Note: n/a = not applicable.
SSG denotes that different site-specific guidelines or formulas were used at sites. Specific site information is available upon request.

Northwest Territories water quality guideline sources:

1. Lumb, A. et al. (2006) Application of CCME Water Quality Index to Monitor Water Quality: A Case Study of the Mackenzie River Basin, Canada. Environmental Monitoring and Assessment 113:411-429 (PDF; 287 kB). Retrieved on December 20, 2023.
   
2. Canadian Council of Ministers of the Environment (2018) Canadian Water Quality Guidelines for the Protection of Aquatic Life Summary Table. Retrieved on December 20, 2023.
3. Government of Canada (2008) Technical Guidance Document for Water Quality Index Practitioners Reporting Under the Canadian Environmental Sustainability Indicators (CESI) Initiative 2008. Environment and Climate Change Canada and Statistics Canada. Retrieved on December 20, 2023.

Note: n/a = not applicable.

Nova Scotia water quality guideline sources:

1. Canadian Council of Ministers of the Environment (2018) Canadian Water Quality Guidelines for the Protection of Aquatic Life Summary Table. Retrieved on December 20, 2023.
2. Government of Canada (2008) Technical Guidance Document for Water Quality Index Practitioners Reporting Under the Canadian Environmental Sustainability Indicators (CESI) Initiative 2008. Environment and Climate Change Canada and Statistics Canada. Retrieved on December 20, 2023.

Ontario water quality guideline sources:

1. Canadian Council of Ministers of the Environment (2018) Canadian Water Quality Guidelines for the Protection of Aquatic Life Summary Table. Retrieved on December 20, 2023.
2. Government of Canada (2008) Technical Guidance Document for Water Quality Index Practitioners Reporting Under the Canadian Environmental Sustainability Indicators (CESI) Initiative 2008. Environment and Climate Change Canada and Statistics Canada. Retrieved on December 20, 2023.
3. Ontario Ministry of the Environment and Energy (1994) Water Management Policies, Guidelines, Provincial Water Quality Objectives. Retrieved on December 20, 2023.

Note: n/a = not applicable.
SSG denotes that different site-specific guidelines or formulas were used at sites. Specific site information is available upon request.

Prince Edward Island water quality guideline sources:

1. Canadian Council of Ministers of the Environment (2018) Canadian Water Quality Guidelines for the Protection of Aquatic Life Summary Table. Retrieved on December 20, 2023.
2. Bugden, G., Jiang, Y., van den Heuvel, MR., Vandermeulen, H., MacQuarrie, KTB., Crane, CJ. and Raymond, BG. (2014) Nitrogen Loading Criteria For Estuaries In Prince Edward Island. Canadian Technical Report of Fisheries and Aquatic Sciences (PDF; 1.10 MB). Retrieved on December 20, 2023.
3. Van den Heuvel, MR. (2009) Site Specific Guidelines for Phosphorus in relation to the Water Quality Index Calculations for Prince Edward Island (PDF; 1.49 MB). Canadian Rivers Institute, University of Prince Edward Island. 35pp. Retrieved on December 20, 2023.

Note: n/a = not applicable.
^[A] Only applies to sites monitored under federal monitoring programs.

Quebec water quality guideline sources:

1. Canadian Council of Ministers of the Environment (2018) Canadian Water Quality Guidelines for the Protection of Aquatic Life Summary Table. Retrieved on December 20, 2023.
2. Ministère de l'Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (2023) Critères de la qualité de l'eau de surface (in French only). Retrieved on December 20, 2023.
3. Government of Canada (2008) Technical Guidance Document for Water Quality Index Practitioners Reporting Under the Canadian Environmental Sustainability Indicators (CESI) Initiative 2008. Environment and Climate Change Canada and Statistics Canada. Retrieved on December 20, 2023.

Note: n/a = not applicable.

[A] Applies to sites monitored under provincial monitoring programs.
[B] Applies to sites monitored under federal monitoring programs (Prairie Provinces Water Board).
SSG denotes that different site-specific guidelines or formulas were used at sites. Specific site information is available upon request.

Saskatchewan water quality guideline sources:

1. Canadian Council of Ministers of the Environment (2018) Canadian Water Quality Guidelines for the Protection of Aquatic Life Summary Table. Retrieved on December 20, 2023.
2. Government of Canada (2008) Technical Guidance Document for Water Quality Index Practitioners Reporting Under the Canadian Environmental Sustainability Indicators (CESI) Initiative 2008. Environment and Climate Change Canada and Statistics Canada. Retrieved on December 20, 2023.
3. Prairie Provinces Water Board (2015). Review of the 1992 Interprovincial Water Quality Objectives and Recommendations for Change. Technical Report to the PPWB Committee on Water Quality, Report #174, Regina.
4. Canadian Council of Ministers of the Environment (2004). Canadian Water Quality Guidelines for the Protection of Aquatic Life: Phosphorus: Canadian Guidance Framework for the Management of Freshwater Systems (PDF; 542 kB). Retrieved on December 20, 2023.

    

Note: n/a = not applicable.
SSG denotes that different site-specific guidelines or formulas were used at sites. Specific site information is available upon request.

Yukon water quality guideline sources:

1. Canadian Council of Ministers of the Environment (2018) Canadian Water Quality Guidelines for the Protection of Aquatic Life Summary Table. Retrieved on December 20, 2023.
2. Environment and Climate Change Canada (2005) Site-specific Water Quality Guidelines for the Liard River at Upper Crossing for the Purpose of National Reporting. Tri-Star Environmental Consulting.
3. Government of Canada (2008) Technical Guidance Document for Water Quality Index Practitioners Reporting Under the Canadian Environmental Sustainability Indicators (CESI) Initiative 2008. Environment and Climate Change Canada and Statistics Canada. Retrieved on December 20, 2023.
4. Nordin, RN. and Pommen, LW. (2009) Water Quality Criteria for Nitrogen (Nitrate, Nitrite, and Ammonia): Overview Report (PDF; 565 kB). Retrieved on December 20, 2023.
5. British Columbia Ministry of Environment (1997) Ambient Water Quality Criteria for Dissolved Oxygen (PDF; 126 kB). Retrieved on December 20, 2023.
6. British Columbia Ministry of Environment (2021) British Columbia Working Water Quality Guidelines: Aquatic Life, Wildlife & Agriculture (PDF; 745 kB). Retrieved on December 20, 2023.