Releases of harmful substances to water

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The release of some substances to the environment can harm human health, wildlife and biological diversity. Toxic metals released to water can enter the food web and accumulate in the tissues of living organisms. Exposure to these substances, even in small amounts, can be hazardous to both humans and wildlife. Mercury and its compounds, lead, and inorganic cadmium compounds are listed as toxicFootnote 1  under the Canadian Environmental Protection Act, 1999. The Releases of harmful substances to water indicator reports facility-based releases of these substances to water.Footnote 2

Summary

Key results

  • Facility-based releases of mercury, lead and cadmium to water were 74%, 73% and 55% lower in 2021 than in 2003, respectively
  • In 2014, a significant spillFootnote 3  accounted for 92%, 92% and 59% of total releases of mercury, lead and cadmium, respectively

Facility-based releases of mercury, lead and cadmium to water, Canada, 2003 to 2021

Facility-based releases of mercury, lead and cadmium to water, Canada, 2003 to 2019 (see long description below)
Data table for the long description
Facility-based releases of mercury, lead and cadmium to water, Canada, 2003 to 2021
Year Mercury
(percentage change from 2003 level)
Lead
(percentage change from 2003 level)
Cadmium
(percentage change from 2003 level)
2003 0 0 0
2004 -11 -14 -6
2005 40 -13 -31
2006 -11 -21 -24
2007 -33 -41 -24
2008 -44 -14 -49
2009 -10 -32 -35
2010 -32 -22 -45
2011 -6 -29 -43
2012 -54 -42 -45
2013 -44 -47 -44
2014 508 499 28
2015 -71 -61 -55
2016 -63 -63 -50
2017 -68 -62 -45
2018 -71 -56 -46
2019 -72 -61 -41
2020 -76 -69 -53
2021 -74 -73 -55

Download data file (Excel/CSV; 1.34 kB)

How this indicator was calculated

Note: The indicator reports facility-based releases only. This chart accounts only for the releases to water reported in the National Pollutant Release Inventory based on the inventory reporting criteria for releases of mercury, lead and cadmium and their compounds. These amounts should not be interpreted as comprehensive totals of releases to water of these pollutants in Canada. In 2014, a significant spill at the Mount Polley mine in central British Columbia accounted for large releases of mercury, lead and cadmium to water.
Source: Environment and Climate Change Canada (2023) National Pollutant Release Inventory.

Mercury, lead and cadmium are naturally occurring elements. Most releases of mercury, lead and cadmium to water are contained in effluent from wastewater treatment facilities. Wastewater treatment facilities do not generate mercury, lead or cadmium. Mercury, lead and cadmium found in wastewater effluents usually comes from industrial discharges to sewers.

In 2021, releases from wastewater treatment facilities accounted for 57%, 53% and 47% of total releases of mercury, lead and cadmium, respectively. From 2003 to 2021, releases of mercury, lead, and cadmium from wastewater treatment facilities declined by 82%, 77% and 67%, respectively.

Mercury

Releases of mercury to water

Mercury is a naturally occurring metal that can be emitted by natural processes (like melting permafrost, volcanic activity and soil and rock erosion). Industrial activities such as the pulp and paper industry, mining operations and metal processing release mercury to water both directly to the environment and indirectly through wastewater treatment facilities. Improper disposal of mercury-containing products (such as fluorescent lamps, thermometers and waste dental amalgams) can also be a source.Footnote 4 Footnote

Mercury can have significant negative impacts on human health and the environment. It persists in the environment and accumulates in food chains over time, posing a particular risk to populations, like the northern and Indigenous communities, who rely heavily on the consumption of predatory fish, such as freshwater trout or Arctic char, and traditional food items, including marine mammals.

National mercury releases to water by source
Mercury releases to water by province and territory
Mercury releases to water from facilities

National mercury releases to water by source

Key results

  • Between 2003 and 2021, mercury releases to water have declined by 74% or 284 kilograms (kg)
  • In 2021, national releases totalled 98 kg
    • the largest pathway was wastewater treatment facilities, representing 57% (55 kg) of the total
  • A significant spillFootnote 3  in 2014 accounted for 92% (2 143 kg) of the 2 322 kg of mercury released in that year

Facility-based mercury releases to water by source, Canada, 2003 to 2021

Facility-based mercury releases to water by source, Canada, 2003 to 2019 (see long description below)
Data table for the long description
Facility-based mercury releases to water by source, Canada, 2003 to 2021
Year Wastewater treatment
(releases to water in kilograms)
Mining and rock quarrying
(releases to water in kilograms)
Non-ferrous smelting and refining
(releases to water in kilograms)
Pulp and paper industry
(releases to water in kilograms)
Other sources
(releases to water in kilograms)
Total
(releases to water in kilograms)
2003 306.7 1.5 14.1 24.1 35.3 381.6
2004 272.7 8.2 13.3 17.5 26.1 337.8
2005 435.2 1.0 53.4 14.0 29.1 532.6
2006 226.9 3.5 61.6 26.3 20.8 339.1
2007 169.4 4.1 31.2 25.6 24.0 254.3
2008 149.7 3.9 10.7 22.8 25.3 212.4
2009 167.5 17.7 9.4 83.6 66.6 344.9
2010 137.9 6.4 23.4 71.0 21.9 260.5
2011 173.6 90.2 9.3 68.2 13.5 358.9
2012 100.3 17.0 5.9 43.9 9.4 176.4
2013 123.6 38.6 8.5 34.6 6.5 211.8
2014 87.4 2 174.4 10.4 47.8 1.7 2 321.7
2015 77.9 5.1 5.5 21.7 1.6 111.8
2016 83.2 3.4 30.7 21.0 4.1 142.5
2017 81.4 6.9 12.0 19.3 0.7 120.3
2018 80.8 2.6 14.3 11.3 1.8 110.8
2019 59.9 18.5 14.7 11.8 0.8 105.7
2020 65.9 5.4 8.9 11.1 1.4 92.7
2021 55.4 12.9 12.9 15.5 1.2 98.1

Note: Totals may not add up due to rounding.

Download data file (Excel/CSV; 2.55 kB)

How this indicator was calculated

Note: The indicator reports facility-based releases only. The indicator includes the amount of elemental mercury and mercury in any compound, alloy or mixture reported in the National Pollutant Release Inventory based on the inventory reporting criteria. As a result, the reported mercury releases to water account for only a portion of the releases of this toxic pollutant to water in Canada. Other sources include electric utilities, manufacturing (except the pulp and paper industry), the oil and gas industry, ore and mineral industries (except non-ferrous smelting and refining), solid waste management, transportation (road, rail, air and marine) and other miscellaneous sources. For more details on sources, please consult the Data sources and methods.
Source: Environment and Climate Change Canada (2023) National Pollutant Release Inventory.

In 2021, 4 sectors contributed 98.8% (96.7 kg) of total national releases of mercury to water: wastewater treatment, mining and rock quarrying, non-ferrous smelting and refining, and the pulp and paper industry.

The largest reduction in mercury releases to water between 2003 and 2021 was in wastewater treatment, with a reduction of 251 kg (-82%). This decline contributed to 89% of the total decline in mercury releases to water. 

Releases of mercury to water by province and territory

Key results

  • In 2021, British Columbia, Ontario and Quebec made up 93% (91 kg) of national mercury releases to water
  • Between 2003 and 2021
    • the largest reduction in releases of mercury to water was from Ontario, which reduced its releases by 100 kg (-73%)
    • slight increases were reported for Newfoundland and Labrador, and New Brunswick

Facility-based mercury releases to water by province and territory, Canada, 2003, 2011 and 2021

Facility-based mercury releases to water by province and territory, Canada, 2003, 2009 and 2019 (see long description below)
Data table for the long description
Facility-based mercury releases to water by province and territory, Canada, 2003, 2011 and 2021
Province or territory 2003
(releases to water in kilograms)
2011
(releases to water in kilograms)
2021
(releases to water in kilograms)
Newfoundland and Labrador < 0.1 <0.1 1.6
Prince Edward Island n/a n/a n/a
Nova Scotia 0.6 0.7 0.2
New Brunswick 2.0 5.6 2.5
Quebec 122.2 100.1 25.6
Ontario 137.2 121.3 37.6
Manitoba n/a 0.5 0.4
Saskatchewan 0.9 0.2 n/a
Alberta 69.7 88.9 2.0
British Columbia 48.9 37.4 28.0
Yukon n/a n/a n/a
Northwest Territories n/a <0.1 <0.1
Nunavut n/a 4.1 0.4
Canada 381.6 358.9 98.1

Note: n/a = not available, it indicates that the province or territory has no reported releases. Totals may not add up due to rounding.   

Download data file (Excel/CSV; 1.85 kB)

How this indicator was calculated

Note: The indicator reports facility-based releases only. The indicator includes the amount of elemental mercury and mercury in any compound, alloy or mixture reported in the National Pollutant Release Inventory based on the inventory reporting criteria. As a result, the reported mercury releases to water represent only a portion of the releases of this toxic pollutant to water in Canada. Some reported releases from Newfoundland and Labrador, Nova Scotia, Manitoba, Saskatchewan and the Northwest Territories and are too small to see in the figure. The figure provides a snapshot of mercury releases by province and territory. To access all available years data please refer to the indicator’s interactive figures or, for the full dataset, to the National Pollutant Release Inventory.
Source: Environment and Climate Change Canada (2023) National Pollutant Release Inventory.

In 2021, mercury releases to water were highest in Ontario, accounting for 38% (38 kg) of the national total. Wastewater treatment facilities were the primary pathway of releases in the province.

Ontario had the largest decline in mercury releases between 2003 and 2021, while Quebec had the second largest. The declines in these provinces were mostly due to large mercury reductions in releases from wastewater treatment facilities as a result of reduced industrial and residential discharges to wastewater systems.

In 2021, the largest source of mercury releases to water within each province and territory was:

  • wastewater treatment in Nova Scotia, British Columbia, Ontario, and Alberta
  • the pulp and paper industry in New Brunswick and Quebec
  • mining and rock quarrying in Manitoba, Newfoundland and Labrador, and the Northwest Territories

Alberta, New Brunswick and Nova Scotia had higher mercury releases in 2011 compared to 2003. Mercury releases in Alberta peaked in 2009 at 149 kg as a result of reported releases from a pulp and paper mill, an oil and gas extraction facility and a wastewater treatment facility. Although not shown in the figure above, releases to water in Alberta remained above 2003 levels for 2 additional years (2010 and 2011) before declining. Mercury releases to water in New Brunswick were above 2003 levels annually from 2004 to 2021. Releases in New Brunswick fluctuated from 2003 to 2014 before declining sharply. British Columbia, Ontario and Quebec all have significantly lower mercury releases in 2021 compared to 2003. Between 2011 and 2021 reported mercury releases declined in Alberta (-98%), Quebec (-74%), Nova Scotia (-73%), Ontario (-69%), New Brunswick (-55%), British Columbia (-25%), and Manitoba (-20%).

Prince Edward Island, Yukon and Nunavut have never reported releases to the National Pollutant Release Inventory of mercury to water. Manitoba had no reported releases in 2003, the Northwest Territories had no reported releases from 2003 to 2012. Saskatchewan did not report any releases of mercury to water in 2021.

Releases of mercury to water from facilities

The National Pollutant Release Inventory provides detailed information on emissions and releases from industrial and commercial facilities that meet its reporting criteria.

The Canadian Environmental Sustainability Indicators provide access to this information through an interactive map. The map allows you to explore releases of mercury to water from individual facilities.

In 2021, 96 facilities across Canada reported mercury releases. Of these facilities:

  • 28 facilities reported releases under 0.01 kilograms (kg)
  • 62 facilities reported releases between 0.01 to 5 kg
  • 6 facilities reported releases over 5 kg, which were located in Ontario (2), British Columbia (3) and Quebec (1)

Releases of mercury to water by facility, Canada, 2021

Releases of mercury to water by facility, Canada, 2019
Long description

The map of Canada shows the amount of mercury in kilograms released to water in 2021 by facility. Facilities are categorized by the amount of mercury released. The categories are: less than 0.01 kilograms, 0.01 to less than 0.25 kilograms, 0.25 to less than 1 kilogram, 1 to less than 2.5 kilograms, 2.5 to less than 5 kilograms and 5 to 9 kilograms.

Data for the map

Navigate data using the interactive map

How this indicator was calculated

Source: Environment and Climate Change Canada (2023) National Pollutant Release Inventory.

Lead

Releases of lead to water

Lead is a naturally occurring metal found in the Earth's crust and can be released during natural processes, such as rock and soil erosion. Lead is also released directly to the environment from sources such as the pulp and paper industry, metal processing, mining and rock quarrying, and indirectly through wastewater treatment facilities. Lead found in wastewater effluents usually comes from industrial discharges to sewers and the use of lead pipes. Lead emitted to air can be deposited on land or water surfaces and then build up in soils, sediments, humans and wildlife.

Lead is a highly toxic metal. Exposure to lead, even in small amounts, can be hazardous to both humans and wildlife. In humans, chronic exposure to relatively low levels may affect the central and peripheral nervous systems, blood pressure, and renal function and may result in reproductive problems and developmental neurotoxicity.

National lead releases to water by source
Lead releases to water by province and territory
Lead releases to water from facilities
Other sources of lead releases to the environment

National lead releases to water by source

Key results

  •  Between 2003 and 2021, lead releases to water have decreased by 73% or 17 736 kilograms (kg)
  • In 2021, national releases totalled 6 603 kg
    • the largest pathway was wastewater treatment facilities, representing 53% (3 483 kg) of the total
  • A significant spill in 2014 generated 92% (134 235 kg) of the 145 709 kg of lead releasedFootnote 3  in that year

Facility-based lead releases to water by source, Canada, 2003 to 2021

Facility-based lead releases to water by source, Canada, 2003 to 2019 (see long description below)
Data table for the long description
Facility-based lead releases to water by source, Canada, 2003 to 2021
Year Wastewater treatment
(releases to water in kilograms)
Pulp and paper industry
(releases to water in kilograms)
Other sources
(releases to water in kilograms)
Non-ferrous smelting and refining
(releases to water in kilograms)
Mining and rock quarrying
(releases to water in kilograms)
Total
(releases to water in kilograms)
2003 15 487.1 2 583.0 1 901.8 2 253.9 2 112.9 24 338.7
2004 11 526.4 2 886.4 1 631.8 2 881.5 1 925.5 20 851.7
2005 9 472.5 3 340.5 1 964.5 2 778.4 3 713.5 21 269.4
2006 9 899.8 2 365.9 1 569.5 1 874.6 3 429.6 19 139.3
2007 6 417.4 2 370.8 1 396.1 1 819.4 2 252.4 14 256.2
2008 11 582.8 2 424.6 1 493.6 2 194.1 3 274.9 20 970.0
2009 8 475.9 2 252.7 1 971.6 2 148.8 1 611.5 16 460.4
2010 11 973.3 2 117.4 1 938.8 1 526.6 1 341.9 18 898.0
2011 8 990.8 2 908.8 1 886.3 1 518.9 1 876.0 17 180.8
2012 4 698.6 2 864.8 1 642.4 1 773.6 3 074.4 14 053.8
2013 4 660.3 2 423.3 1 905.9 1 483.6 2 388.7 12 861.9
2014 5 114.7 1 849.4 1 417.6 1 768.1 135 559.6 145 709.4
2015 4 395.9 1 459.9 1 236.7 1 338.7 994.7 9 426.0
2016 3 880.0 1 576.9 855.7 1 527.6 1 042.0 8 882.2
2017 4 375.8 1 444.0 1 131.3 1 111.4 1 078.4 9 140.9
2018 4 596.9 3013.7 1 343.5 1 117.8 620.5 10 692.4
2019 4 717.7 2 135.2 1 329.5 1 136.9 270.9 9 590.3
2020 4 191.6 1 122.5 1 004.1 1 085.7 240.3 7 644.2
2021 3 482.6 940.5 1 081.9 790.3 307.7 6 603.1

Note: Totals may not add up due to rounding.

Download data file (Excel/CSV; 2.73 kB)

How this indicator was calculated

Note: The indicator reports facility-based releases only. The indicator includes the amount of elemental lead and lead in any compound, alloy or mixture reported in the National Pollutant Release Inventory based on the inventory reporting criteria. As a result, the reported lead releases to water account for only a portion of the releases of this toxic pollutant to water in Canada. Other sources include electric utilities, manufacturing (except the pulp and paper industry), the oil and gas industry, ore and mineral industries (except non-ferrous smelting and refining), solid waste management, transportation (road, rail, air and marine) and other miscellaneous sources. For more details on sources, please consult the Data sources and methods.
Source: Environment and Climate Change Canada (2023) National Pollutant Release Inventory.

In 2021, 84% (5 521 kg) of national releases of lead to water came from wastewater treatment facilities, the pulp and paper industry, non-ferrous smelting and refining and mining and rock quarrying.

Wastewater treatment contributed to 68% (12 005 kg) of the total reduction in lead releases to water since 2003. This was largely due to decreases in upstream discharges to wastewater effluent. Mining and rock quarrying, the pulp and paper industry and non-ferrous smelting and refining contributed a further 10% (1 805 kg), 9% (1 643 kg) and 8% (1464 kg), respectively, to the decrease in releases.

Releases of lead to water by province and territory

Key results

  • In 2021, Quebec, Ontario and British Columbia made up 87% (5 734 kg) of national lead releases to water
  • Between 2003 and 2021
    • the largest reduction in releases of lead to water was from Ontario, which reduced its releases by 5 993 kg (-72%)
    • Nova Scotia is the only province that reported an increase in lead releases to water, with an increase of 117 kg

Facility-based lead releases to water by province and territory, Canada, 2003, 2011 and 2021

Facility-based lead releases to water by province and territory, Canada, 2003, 2009 and 2019 (see long description below)
Data table for the long description
Facility-based lead releases to water by province and territory, Canada, 2003, 2011 and 2021
Province or territory 2003
(releases to water in kilograms)
2011
(releases to water in kilograms)
2021
(releases to water in kilograms)
Newfoundland and Labrador 1 670.0 648.5 68.5
Prince Edward Island n/a 5.6 7.2
Nova Scotia 3.9 732.3 121.0
New Brunswick 724.9 1 314.1 313.8
Quebec 6 296.2 3 516.9 1 826.2
Ontario 8 321.2 6 929.0 2 328.1
Manitoba 1 385.0 182.4 65.7
Saskatchewan 217.1 27.2 24.8
Alberta 1 141.5 942.4 267.9
British Columbia 4 563.9 2 887.4 1 579.4
Yukon n/a n/a n/a
Northwest Territories n/a <0.1 0.3
Nunavut 15.0 4.1 0.4
Canada 24 338.7 17 180.8 6 603.1

Note: n/a = not available, it indicates that the province or territory has no reported releases. Totals may not add up due to rounding.

Download data file (Excel/CSV; 1.88 kB)

How this indicator was calculated

Note: The indicator reports facility-based releases only. The indicator includes the amount of elemental lead and lead in any compound, alloy or mixture reported in the National Pollutant Release Inventory based on the inventory reporting criteria. As a result, the reported lead releases to water represent only a portion of the releases of this toxic pollutant to water in Canada. Some reported releases from Prince Edward Island, Nova Scotia, Saskatchewan, the Northwest Territories and Nunavut are too small to see in the figure. The figure provides a snapshot of lead releases by province and territory, to access all available years data please refer to the indicator’s interactive figures or, for the full dataset, to the National Pollutant Release Inventory.
Source: Environment and Climate Change Canada (2023) National Pollutant Release Inventory.

In 2021, lead releases to water were highest in Ontario, accounting for 35% (2 328 kg) of the national total.

Ontario had the largest decline in lead releases between 2003 and 2021. This decline was mostly due to reductions in releases from wastewater treatment facilities. Nova Scotia had the largest increase in releases over this period, although actual releases in 2021 represented 2% of the national total. The results in Nova Scotia were mostly due to releases from a single wastewater treatment facility.

In 2021, the largest source of lead releases to water within each province and territory was:

  • wastewater treatment in Ontario, Quebec, Alberta, Nova Scotia, Manitoba, Saskatchewan and Prince Edward Island
  • the pulp and paper industry in New Brunswick and Newfoundland and Labrador
  • mining and rock quarrying in Nunavut and the Northwest Territories
  • non-ferrous smelting and refining in British Columbia

Nova Scotia had higher lead releases in 2011 (723 kg) compared to 2003 (3.9 kg). While not shown in the figure above, lead releases in Nova Scotia peaked in 2011 at 723 kg as a result of 2 wastewater treatment facilities reporting high releases due to influxes of upstream influent. Provincially-reported releases from the wastewater treatment sector fluctuated from 2012 to 2016 as releases from facilities exceeded or remained below the minimum reporting threshold. Reported releases from a single wastewater treatment facility accounted for 99.9% of the total lead releases for Nova Scotia from 2017 to 2021.

In 2003, there were no reported releases to the National Pollutant Release Inventory of lead in Prince Edward Island, Yukon and the Northwest Territories. In 2011 and 2021, all provinces and territories reported releases, except for Yukon.

Releases of lead to water from facilities

The National Pollutant Release Inventory provides detailed information on emissions and releases from industrial and commercial facilities that meet its reporting criteria.

The Canadian Environmental Sustainability Indicators provide access to this information through an interactive map. The map allows you to explore releases of lead to water from individual facilities.

In 2021, 199 facilities across Canada reported lead releases. Of these facilities:

  • 58 facilities reported releases under 0.5 kilograms (kg)
  • 126 facilities reported releases between 0.5 to 100 kg
  • 15 facilities reported releases over 100 kg, which were located in Ontario (7), Quebec (4), British Columbia (2), Alberta (1) and Nova Scotia (1)

Releases of lead to water by facility, Canada, 2021

Releases of lead to water by facility, Canada, 2019
Long description

The map of Canada shows the amount of lead in kilograms released to water in 2021 by facility. Facilities are categorized by the amount of lead released. The categories are: less than 0.5 kilograms, 0.5 to less than 5 kilograms, 5 to less than 20 kilograms, 20 to less than 50 kilograms, 50 to less than 100 kilograms and 100 to 639 kilograms.

Data for the map

Navigate data using the interactive map

How this indicator was calculated

Source: Environment and Climate Change Canada (2023) National Pollutant Release Inventory.

Other sources of lead releases to the environment

Other sources of lead releases correspond to non-industrial releases that are not included in the National Pollutant Release Inventory. Releases from these sources are therefore not considered in the analysis of the indicators. 

Lead releases to water

Fishing tackle containing lead can pose a serious threat to birds if ingested. Ingestion can lead to blindness, muscle paralysis, reduced reproductive ability, seizures and death. A single sinker or jig containing several grams of lead is enough to kill a bird. It is estimated every year approximately 460 tonnes of lead sinkers and jigs are lost into Canada's lakes and waterways.Footnote 5  This represents the most significant annual source of lead releases to water in Canada.

Lead releases to land

In Canada, the largest source of lead releases onto land is ammunition. Lead ammunition releases can eventually end up in water through leaching into soils and groundwater and by hunting over or near water bodies. Annually, ammunition used for recreational shooting, hunting and enforcement releases an estimated 5 200 tonnes of lead into the environment.Footnote 6  Migratory bird hunters are required by law to use non-toxic shot. However, recreational shooting and other game hunting remain a significant source of lead releases. The use of lead-free ammunition would help prevent contamination of soil, water and game meat that may be consumed by Canadians or by scavenging animals.

Cadmium

Releases of cadmium to water

Cadmium is a naturally occurring metal found in the Earth's crust and can be released during natural processes, such as rock and soil erosion. It can also be released directly to the environment from human activities such as non-ferrous smelting and refining, and fuel consumption for electricity or heating, and indirectly through wastewater treatment facilities. Cadmium found in wastewater effluents usually comes from industrial discharges to sewers. Cadmium is used in batteries and in electroplating to protect other metals from corrosion.

Exposure to cadmium can be hazardous to both humans and wildlife since it accumulates in the food chain over time. The Government of Canada concluded cadmium compounds may be harmful to the environment and may constitute a danger based on their carcinogenic potential. Exposure to cadmium has been associated with gastrointestinal irritation and harmful effects to the kidneys and bones.

National cadmium releases to water by source
Cadmium releases to water by province and territory
Cadmium releases to water from facilities

National cadmium releases to water by source

Key results

  • Between 2003 and 2021, cadmium releases to water have declined by 55% or 2 711 kilograms (kg)
  • In 2021, national releases totalled 2 233 kg
    • the largest pathway was wastewater treatment facilities, representing about 47% (1 059 kg) of national releases
  • A significant spill in 2014 accounted for 59% (3 768 kg) of the 6 339 kg of cadmium releasedFootnote 3  that year

Facility-based cadmium releases to water by source, Canada, 2003 to 2021

Facility-based cadmium releases to water by source, Canada, 2003 to 2019 (see long description below)
Data table for the long description
Facility-based cadmium releases to water by source, Canada, 2003 to 2021
Year Wastewater treatment
(releases to water in kilograms)
Pulp and paper industry
(releases to water in kilograms)
Non-ferrous smelting and refining
(releases to water in kilograms)
Other sources
(releases to water in kilograms)
Mining and rock quarrying
(releases to water in kilograms)
Total
(releases to water in kilograms)
2003 3 195.1 1 012.2 426.4 129.7 181.2 4 944.6
2004 2 258.8 957.7 867.8 136.5 423.8 4 644.6
2005 1 391.2 931.6 454.0 229.4 402.1 3 408.3
2006 1 452.3 1 076.4 435.3 267.6 514.9 3 746.5
2007 1 115.0 1 104.2 877.7 264.2 396.6 3 757.7
2008 979.1 766.1 394.8 348.1 54.2 2 542.2
2009 1 260.1 710.4 365.4 511.6 368.9 3 216.4
2010 1 212.8 704.5 289.0 345.6 189.0 2 741.0
2011 1 356.3 777.4 321.5 201.8 134.5 2 791.5
2012 1 233.2 809.4 327.0 200.9 158.9 2 729.3
2013 902.2 1 095.6 352.2 145.9 268.0 2 763.8
2014 968.0 941.5 319.5 107.9 4 001.7 6 338.6
2015 976.7 783.0 287.3 83.8 114.7 2 245.5
2016 1 117.7 838.6 314.1 103.5 110.5 2 484.5
2017 1 234.6 866.5 282.2 116.5 237.7 2 737.4
2018 1 199.3 814.3 229.6 130.0 301.6 2 674.9
2019 1 645.8 796.5 311.9 54.1 128.7 2 937.0
2020 1 194.5 704.7 281.4 31.4 131.9 2 343.9
2021 1 059.1 647.8 210.4 211.0 105.2 2 233.4

Note: Totals may not add up due to rounding.

Download data file (Excel/CSV; 2.66 kB)

How this indicator was calculated

Note: The indicator reports facility-based releases only. The indicator includes the amount of elemental cadmium and cadmium in any compound, alloy or mixture reported in the National Pollutant Release Inventory based on the inventory reporting criteria. As a result, the reported cadmium releases to water account for only a portion of the releases of this toxic pollutant to water in Canada. Other sources include electric utilities, manufacturing (except the pulp and paper industry), the oil and gas industry, ore and mineral industries (except non-ferrous smelting and refining), solid waste management, transportation (road, rail, air and marine) and other miscellaneous sources. For more details on sources, please consult the Data sources and methods.
Source: Environment and Climate Change Canada (2023) National Pollutant Release Inventory.

In 2021, 76% (1 707 kg) of cadmium released to water came from wastewater treatment facilities and the pulp and paper industry.

Wastewater treatment contributed to 79% (2 136 kg) of the total reduction in cadmium releases to water since 2003. This was largely due to decreases in upstream discharges to wastewater effluent. The pulp and paper and non-ferrous smelting and refining industries together contributed an additional 21% (364 kg and 216 kg, respectively) to the total reduction in cadmium releases from 2003 to 2021.

In recent years (from 2015 to 2019), releases of cadmium to water have increased before decreasing again in 2020 and 2021. This increase was mainly due to reported increases from wastewater treatment facilities, and ore and mineral industries (except non-ferrous smelting and refining). 

Releases of cadmium to water by province and territory

Key results

  • In 2021, Ontario, Quebec and British Columbia made up 80% (1 784 kg) of national cadmium releases to water
  • Between 2003 and 2021,
    • the largest reduction in releases of cadmium to water was from Quebec, which reduced its releases by 2 137 kg (-84%)
    • the largest increase in cadmium releases to water was from Ontario, which had a 47 kg (+6%) increase in releases

Facility-based cadmium releases to water by province and territory, Canada, 2003, 2011 and 2021

Facility-based cadmium releases to water by province and territory, Canada, 2003, 2009 and 2019 (see long description below)
Data table for the long description
Facility-based cadmium releases to water by province and territory, Canada, 2003, 2011 and 2021
Province or territory 2003
(releases to water in kilograms)
2011
(releases to water in kilograms)
2021
(releases to water in kilograms)
Newfoundland and Labrador 8.4 2.9 5.5
Prince Edward Island n/a 0.9 15.7
Nova Scotia 12.1 53.8 1.7
New Brunswick 184.8 144.8 92.5
Quebec 2 544.8 584.0 407.4
Ontario 843.6 945.2 890.7
Manitoba 360.3 44.8 27.2
Saskatchewan 31.8 2.2 1.9
Alberta 258.3 303.2 304.4
British Columbia 700.3 709.5 486.2
Yukon n/a n/a n/a
Northwest Territories n/a n/a 0.2
Nunavut 0.2 0.3 <0.1
Canada 4 944.6 2 791.5 2 233.4

Note: n/a = not available, it indicates that the province or territory has no reported releases. Totals may not add up due to rounding.

Download data file (Excel/CSV; 1.87 kB)

How this indicator was calculated

Note: The indicator reports facility-based releases only. The indicator includes the amount of elemental cadmium and cadmium in any compound, alloy or mixture reported in the National Pollutant Release Inventory based on the inventory reporting criteria. As a result, the reported cadmium releases to water represent only a portion of the releases of this toxic pollutant to water in Canada. Some reported releases from Newfoundland and Labrador, Prince Edward Island, Nova Scotia, Saskatchewan, the Northwest Territories and Nunavut are too small to see in the figure. The figure provides a snapshot of cadmium releases by province and territory, to access all available years data please refer to the indicator’s interactive figures or, for the full dataset, to the National Pollutant Release Inventory.
Source: Environment and Climate Change Canada (2023) National Pollutant Release Inventory.

In 2021, cadmium releases to water were highest in Ontario, accounting for 40% (891 kg) of the national total. Wastewater treatment was the main source of these releases.

In 2021, the largest source of cadmium releases to water within each province and territory was:

  • wastewater treatment in Ontario, Prince Edward Island and Saskatchewan
  • the pulp and paper industry in Quebec, British Columbia, New Brunswick, and Newfoundland and Labrador
  • mining and rock quarrying in Manitoba, Nunavut and the Northwest Territories
  • other sources in Alberta and Nova Scotia

Between 2003 and 2021, reported cadmium releases decreased in all provinces and territories, except Ontario and Alberta. However, British Columbia, Nova Scotia, and Nunavut had higher cadmium releases in 2011 compared to 2003. Following that increase, reported releases between 2011 and 2021 declined by 31%, 97%, and 79%, respectively.

Although not shown in the figure above, reported releases of cadmium to water in New Brunswick peaked in 2007 at 966 kg. Releases within the province were above 2003 levels from 2004 to 2009 and again in 2013. In Alberta, releases exceeded 2003 levels in 2009 and from 2011 to 2014, peaking at 353 kg in 2012. Reported releases of cadmium to water in British Columbia exceeded 2003 levels from 2009 to 2015 and again in 2017. Releases peaked in 2014 at 4 646 kg, primarily as a result of the significant tailings pond spill at the Mount Polley mine.

Yukon has never reported releases to the National Pollutant Release Inventory of cadmium to water. In 2003 and 2011, there were no reported releases of cadmium in the Northwest Territories.

Releases of cadmium to water from facilities

The National Pollutant Release Inventory provides detailed information on emissions and releases from industrial and commercial facilities that meet its reporting criteria.

The Canadian Environmental Sustainability Indicators provide access to this information through an interactive map. The map allows you to explore releases of cadmium to water from individual facilities.

In 2021, 168 facilities across Canada reported cadmium releases. Of these facilities:

  • 75 facilities reported releases under 0.5 kilograms (kg)
  • 81 facilities reported releases between 0.5 to 40 kg
  • 12 facilities reported releases over 40 kg, which were located in British Columbia (5), Ontario (4), Quebec (2) and Alberta (1)

Releases of cadmium to water by facility, Canada, 2021

Releases of cadmium to water by facility, Canada, 2019 (see long description below)
Long description

The map of Canada shows the amount of cadmium in kilograms released to water in 2021 by facility. Facilities are categorized by the amount of cadmium released. The categories are: less than 0.5 kilograms, 0.5 to less than 5 kilograms, 5 to less than 10 kilograms, 10 to less than 20 kilograms, 20 to less than 40 kilograms and 40 to 375 kilograms.

Data for the map

Navigate data using the interactive map

How this indicator was calculated

Source: Environment and Climate Change Canada (2023) National Pollutant Release Inventory.

About the indicators

About the indicators

What the indicators measure

These indicators track facility-based releases to water of 3 substances that are defined as toxic under the Canadian Environmental Protection Act, 1999: mercury, lead and cadmium and their compounds. For each substance, data are provided at the national, regional (provincial and territorial) and facility level and by source.

Why these indicators are important

Mercury and its compounds, lead and inorganic cadmium compounds are on the Toxic substances list under Schedule 1 of the Canadian Environmental Protection Act, 1999. This means that these substances are "entering or may enter the environment in a quantity or concentration or under conditions that (a) have or may have an immediate or long-term harmful effect on the environment or its biological diversity; (b) constitute or may constitute a danger to the environment on which life depends; or (c) constitute or may constitute a danger in Canada to human life or health."

The indicators inform Canadians about releases to water of these 3 substances from facilities in Canada. The Releases of harmful substances to water indicators also help the government to identify priorities and develop or revise strategies to inform further risk management and to track progress on policies put in place to reduce or control these 3 substances and water pollution in general.

Related initiatives

These indicators support the measurement of progress towards the following 2022 to 2026 Federal Sustainable Development Strategy Goal 12: Reduce waste and transition to zero-emission vehicles and Goal 6: Ensure clean and safe water for all Canadians.

In addition, the indicators contribute to the Sustainable Development Goals of the 2030 Agenda for Sustainable Development. They are linked to the 2030 Agenda's Goal 12, Responsible consumption and production and Target 12.4, "By 2020, achieve the environmentally sound management of chemicals and all wastes throughout their life cycle, in accordance with agreed international frameworks, and significantly reduce their release to air, water and soil in order to minimize their adverse impacts on human health and the environment." 

Related indicators

The Emissions of harmful substances to air indicators track human-related emissions to air of 3 toxic substances, namely mercury, lead and cadmium, and their compounds. For each substance, data are provided at the national, provincial/territorial and facility level and by source. Global emissions to air are also provided for mercury.

The Human exposure to harmful substances indicators track the concentrations of 4 substances (mercury, lead, cadmium and bisphenol A) in Canadians.

Data sources and methods

Data sources and methods

Data sources

Data for the indicators and the interactive maps are taken from the National Pollutant Release Inventory (the inventory). These indicators include the amount of elemental mercury, lead and cadmium in any compound, alloy or mixture released to water as reported to the inventory based on its reporting criteria as listed in section 5.3 of the 2022-2024 Guide for Reporting to the National Pollutant Release Inventory (PDF; 3.35 MB).

More information

The inventory is compiled by Environment and Climate Change Canada (the department), and includes releases reported by industrial, commercial and institutional facilities. It is Canada's legislated, publicly accessible inventory of pollutant releases (to air, water and land), disposals and transfers for recycling. It consists of information reported by facilities to the department under the Canadian Environmental Protection Act, 1999 (the act). Under the act, owners or operators of facilities that manufacture, process or otherwise use or release one or more of the substances tracked by the inventory and that meet reporting thresholds and other requirements must report their pollutant releases annually. For mercury, lead, and cadmium, the reporting thresholds are 5 kg, 50 kg, and 5 kg, respectively.

Estimation of releases to water

Releases to water are estimated or measured through one of the following methods:

  • continuous emission monitoring systems
  • predictive emission monitoring
  • source testing
  • mass balance
  • site-specific emission factors
  • published emission factors
  • engineering estimates

These measurement methods and estimation techniques are used by the facilities to report their releases (point sources) to the inventory. The Report to the National Pollutant Release Inventory program web page provides information to owners or operators of facilities required to report to the inventory, as well as details on the program's calculation methods.

Data completeness

Because the indicators are derived solely from the inventory's database, they reflect only releases from facilities that met the reporting criteria. As a result, the indicators do not include all releases in Canada. They are limited to the main point sources for each selected toxic substance.

Data timeliness

The data are current up to 2021. The indicators are reported approximately 1.5 years after data collection because of the time required for data validation, analysis and interpretation.

Methods

The indicators are produced by grouping data from the inventory to report on the key sources that contribute to the majority of mercury, lead and cadmium releases to water.

More information

Indicator coverage

Historical data are provided at the national level and by source for the period from 2003 to 2021. The year 2003 was selected as the first year for releases to water because it was the year the inventory updated its reporting criteria for mercury, lead and cadmium. For the provincial/territorial charts, releases to water are provided for 2003, 2011 and 2021. Releases of mercury, lead and cadmium to water by facility are displayed on the Canadian Environmental Sustainability Indicators' interactive maps.

Sources classification

Source descriptions for the indicators were taken from Statistics Canada's North American Industry Classification System. The 4-digit code of the classification system, as reported by the facilities, was used for source classification for the data reported by the inventory. These sources were then classified into the following sources for reporting in the indicators: :

  • electric utilities
  • manufacturing (except pulp and paper)
  • mining and rock quarrying
  • miscellaneous
  • non-ferrous smelting and refining
  • oil and gas industry
  • ore and mineral industries (except non-ferrous smelting and refining)
  • pulp and paper industry
  • solid waste management
  • transportation (road, rail, air and marine)
  • wastewater treatment

Table 1 shows the allocation of sources of harmful substances reported in the indicators compared with those reported by the inventory.

Table 1. Alignment of sources reported in the Canadian Environmental Sustainability Indicators and the National Pollutant Release Inventory
Sources in the Canadian Environmental Sustainability Indicators Sources in the National Pollutant Release Inventory
(based on the NorthAmerican Industry Classification System)
Electric utilities Electric power generation, transmission and distribution
Manufacturing (except pulp and paper) Aerospace product and parts manufacturing
Manufacturing (except pulp and paper) Basic chemical manufacturing
Manufacturing (except pulp and paper) Cement and concrete product manufacturing
Manufacturing (except pulp and paper) Coating, engraving, cold and heat treating and allied activities
Manufacturing (except pulp and paper) Electrical equipment manufacturing
Manufacturing (except pulp and paper) Electric lighting equipment manufacturing
Manufacturing (except pulp and paper) Engine, turbine and power transmission equipment manufacturing
Manufacturing (except pulp and paper) Forging and stamping
Manufacturing (except pulp and paper) Fruit and vegetable preserving and speciality food manufacturing
Manufacturing (except pulp and paper) Motor vehicle parts manufacturing
Manufacturing (except pulp and paper) Other chemical product manufacturing
Manufacturing (except pulp and paper) Other electrical equipment and component manufacturing
Manufacturing (except pulp and paper) Other fabricated metal product manufacturing
Manufacturing (except pulp and paper) Other food manufacturing
Manufacturing (except pulp and paper) Other miscellaneous manufacturing
Manufacturing (except pulp and paper) Paint, coating and adhesive manufacturing
Manufacturing (except pulp and paper) Pesticide, fertilizer and other agricultural chemical manufacturing
Manufacturing (except pulp and paper) Petroleum and coal productmanufacturing
Manufacturing (except pulp and paper) Pharmaceutical and medicine manufacturing
Manufacturing (except pulp and paper) Rubber product manufacturing
Manufacturing (except pulp and paper) Semiconductor and other electronic component manufacturing
Manufacturing (except pulp and paper) Ship and boat building
Manufacturing (except pulp and paper) Spring and wire product manufacturing
Manufacturing (except pulp and paper) Veneer, plywood and engineered wood product manufacturing
Mining and rock quarrying Coal mining
Mining and rock quarrying Metal ore mining
Mining and rock quarrying Non-metallic mineral mining and quarrying
Miscellaneous Defence service
Miscellaneous Support activities for water transportation
Miscellaneous General medical and surgical hospitals
Miscellaneous Other professional, scientific and technical services
Miscellaneous Recyclable material merchant wholesalers
Non-ferrous metal production and processing Non-ferrous metal (except aluminum) production and processing
Oil and gas industry Oil and gas extraction
Ore and mineral industries (except non-ferrous metal production and processing) Alumina and aluminum production and processing
Ore and mineral industries (exceptnon-ferrous metal production and processing) Foundries
Ore and mineral industries (exceptnon-ferrous metal production and processing) Iron and steel mills and ferro-alloy manufacturing
Ore and mineral industries (exceptnon-ferrous metal production and processing) Steel product manufacturing from purchased steel
Pulp and paper industry Converted paper product manufacturing
Pulp and paper industry Pulp, paper and paperboard mills
Solid waste management Remediation and other waste management services
Solid waste management Waste collection
Solid waste management Waste treatment and disposal
Transportation (road, rail, air and marine) Rail transportation
Wastewater treatment Water, sewage and other systems

For display purposes, sources with smaller releases are sometimes grouped together under the category "Other sources" in the figures and corresponding data tables of releases by source. The grouped sources may differ by substance and are listed in the notes of each figure and data table.

Recent changes

The wastewater and waste management source in the Canadian Environmental Sustainability Indicators was split into 2 separate sources, wastewater treatment and solid waste management. These sources are listed under 2 different North American Industry Classification System codes.

The provincial/territorial comparison of releases to water was expanded to include 2003, the first year data was available. Also included are 2021, the latest year data was available and a 10-year comparison to the latest year, 2011.

Caveats and limitations

The indicators reflect only facility-based releases to water as reported to the inventory. They do not include estimates of releases from other sources, such as runoff from cities, transboundary pollution or from consumer products in Canada.

Occasional updates and data quality checking can be done after initial release of the inventory.

The number and composition of facilities that report releases to water to the inventory vary each year. This variation is due to the fact that only facilities that meet or exceed the reporting threshold are required to report. An analysis of how this might affect the apparent trends has not been undertaken.

Facilities reporting to the inventory may use different methods to calculate releases. These methods vary depending on the substance and/or facility, and may also change from year to year.

The latest year reported (2021) coincides with the second year of the COVID-19 pandemic which had an impact on a wide range of economic sectors, especially the energy and transport sectors. The emissions change for the periods from 2003 to 2021 must be interpreted with caution as the impact of the pandemic on the emissions is not discussed in detail.

Resources

Resources

References

Environment and Climate Change Canada (2018) Moving towards using more lead-free ammunition. Retrieved on June 5, 2023.

Environment and Climate Change Canada (2018) Moving toward using lead-free fishing tackle. Retrieved on June 5, 2023.

Environment and Climate Change Canada (2023) Bulk data files for all years – releases, disposals, transfers and facility locations. Retrieved on June 5, 2023.

Environment and Climate Change Canada (2023) Using and interpreting data from the National Pollutant Release Inventory. Retrieved on June 5, 2023.

Related information

NPRI sector overview: Aluminium

NPRI sector overview: Electricity

NPRI sector overview: Metal ore mining

NPRI sector overview: Oil sands extraction

NPRI sector overview: Wastewater

Interactive figures
Updated July 2023

These interactive figures support the Releases of harmful substances to water indicators. Use them to explore the latest releases emissions data for the 3 harmful substances (mercury, lead and cadmium) in a dynamic and customizable format.

Select data by using the drop-down menu above each figure and clear your selections by clicking the "Reset figures" button on the right-hand side of the dashboard.  All values in the figures will automatically update based on your selections.

You can also choose to use your keyboard to navigate the figures.

Source: Environment and Climate Change Canada (2023) National Pollutant Release Inventory.

Download data file from the National Pollutant Release Inventory (Excel/CSV; 254 MB)

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