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 79%, 71% and 56% lower in 2022 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
- 2022 represented the lowest year on record for releases to water of mercury and cadmium, and the second lowest for lead
Facility-based releases of mercury, lead and cadmium to water, Canada, 2003 to 2022

Data table for the long description
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 | -45 |
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 |
2022 | -79 | -71 | -56 |
Download data file (Excel/CSV; 1.36 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. The amounts presented in this indicator 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 (2024) 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 themselves generate these 3 contaminants. Mercury, lead and cadmium found in wastewater effluents usually comes from industrial discharges to sewers.
In 2022, releases from wastewater treatment facilities accounted for 59%, 54% and 54% of total releases of mercury, lead and cadmium, respectively. From 2003 to 2022, releases of mercury, lead and cadmium from wastewater treatment facilities declined by 84%, 76% and 63%, 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 pulp and paper production, mining operations and metal processing release mercury, both directly to water in 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 of releases to water.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 other 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 2022, mercury releases to water have declined by 79% or 300 kilograms (kg)
- In 2022, national releases totalled 82 kg
- the largest source was wastewater treatment facilities, representing 59% (49 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 2022

Data table for the long description
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 | 354.8 |
2012 | 100.1 | 17.0 | 5.9 | 43.4 | 9.4 | 175.7 |
2013 | 123.5 | 38.6 | 8.5 | 34.3 | 6.5 | 211.4 |
2014 | 87.4 | 2 174.4 | 10.4 | 47.8 | 1.7 | 2 321.7 |
2015 | 77.9 | 5.0 | 5.5 | 21.0 | 1.6 | 111.1 |
2016 | 83.2 | 3.4 | 30.7 | 21.0 | 4.4 | 142.7 |
2017 | 81.4 | 6.9 | 12.0 | 19.3 | 0.7 | 120.3 |
2018 | 80.8 | 2.6 | 14.3 | 11.1 | 1.8 | 110.7 |
2019 | 59.8 | 18.4 | 14.7 | 11.6 | 0.8 | 105.4 |
2020 | 65.9 | 5.4 | 8.9 | 11.1 | 1.4 | 92.7 |
2021 | 55.4 | 12.9 | 12.9 | 15.5 | 1.2 | 97.8 |
2022 | 48.6 | 6.0 | 10.4 | 14.5 | 2.4 | 81.9 |
Note: Totals may not add up due to rounding.
Download data file (Excel/CSV; 2.29 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 (2024) National Pollutant Release Inventory.
In 2022, 4 sectors contributed 97.1% (79.6 kg) of total national releases of mercury to water: wastewater treatment, the pulp and paper industry, non-ferrous smelting and refining, and mining and rock quarrying.
The largest reduction in releases of mercury to water between 2003 and 2022 was in wastewater treatment, with a reduction of 258 kg (-84%). This decline contributed to 86% of the total decline in mercury releases to water.
Releases of mercury to water by province and territory
Key results
- In 2022, Quebec, Ontario and British Columbia made up 93% (76 kg) of national mercury releases to water
- Between 2003 and 2022
- the largest reduction in releases of mercury to water was from Ontario, which reduced its releases by 107 kg (-78%)
- slight increases were reported for Newfoundland and Labrador, and New Brunswick
Facility-based mercury releases to water by province and territory, Canada, 2003, 2012 and 2022

Data table for the long description
Province or territory | 2003 (releases to water in kilograms) |
2012 (releases to water in kilograms) |
2022 (releases to water in kilograms) |
---|---|---|---|
Newfoundland and Labrador | <0.1 | 13.2 | <0.1 |
Prince Edward Island | n/a | n/a | n/a |
Nova Scotia | 0.6 | 0.6 | 0.2 |
New Brunswick | 2.0 | 12.0 | 2.5 |
Quebec | 122.2 | 20.3 | 26.6 |
Ontario | 137.2 | 42.7 | 30.1 |
Manitoba | n/a | 0.4 | 0.4 |
Saskatchewan | 0.9 | 0.3 | n/a |
Alberta | 69.7 | 58.1 | 2.4 |
British Columbia | 48.9 | 28.0 | 19.7 |
Yukon | n/a | n/a | n/a |
Northwest Territories | n/a | 0.1 | <0.1 |
Nunavut | n/a | n/a | <0.1 |
Canada | 381.6 | 175.7 | 81.9 |
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, the Northwest Territories and Nunavut are too small to see in the figure. To access individual provincial data for all years, 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 (2024) National Pollutant Release Inventory.
In 2022, mercury releases to water were highest in Ontario, accounting for 37% (30 kg) of the national total. Wastewater treatment facilities were the primary source of releases in the province. Ontario, Quebec and British Columbia accounted for 93% of national releases of mercury to water.
Ontario had the largest decline in mercury releases between 2003 and 2022, 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 2022, the largest source of mercury releases to water by province and territory was:
- wastewater treatment in Nova Scotia, Ontario, Manitoba, Alberta and British Columbia
- the pulp and paper industry in New Brunswick and Quebec
- mining and rock quarrying in Newfoundland and Labrador, the Northwest Territories, and Nunavut.
Between 2003 and 2022, reported mercury releases decreased in Nova Scotia, Quebec, Ontario, Saskatchewan, Alberta and British Columbia. However, Quebec had a 31% (6.3 kg) increase in mercury releases between 2012 and 2022.
Between 2003 and 2022, reported mercury releases increased in Newfoundland and Labrador, New Brunswick, Manitoba, the Northwest Territories and Nunavut. However, these provinces and territories made up only 3.5% of national releases of mercury in 2022.
Prince Edward Island and Yukon 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, and Saskatchewan did not report any releases of mercury to water in 2022.
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.
Key results
- In 2022, 89 facilities across Canada reported mercury releases. Of these facilities:
- 26 facilities reported releases under 0.01 kilograms (kg)
- 59 facilities reported releases between 0.01 to 5 kg
- 4 facilities reported releases between 5 and 9.36 kg, which were located in Quebec (2), Ontario (1) and British Columbia (1), accounting for 36% of total mercury releases to water
Releases of mercury to water by facility, Canada, 2022

Long description
The map of Canada shows the amount of mercury in kilograms released to water in 2022 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 9.36 kilograms.
Navigate data using the interactive map
How this indicator was calculated
Source: Environment and Climate Change Canada (2024) 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 2022, lead releases to water have decreased by 71% or 17 387 kilograms (kg)
- In 2022, national releases totalled 6 952 kg
- the largest pathway was wastewater treatment facilities, representing 54% (3 783 kg) of the total
- A significant spillFootnote 3 in 2014 generated 92% (134 235 kg) of the 145 709 kg of lead released in that year
Facility-based lead releases to water by source, Canada, 2003 to 2022

Data table for the long description
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 | 2 888.1 | 1 886.3 | 1 518.9 | 1 876.0 | 17 160.1 |
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 | 1 848.3 | 1 417.6 | 1 768.1 | 135 559.6 | 145 708.3 |
2015 | 4 395.9 | 1 459.9 | 1 196.2 | 1 338.7 | 991.3 | 9 382.0 |
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 | 3 013.2 | 1 387.7 | 1 117.8 | 620.5 | 10 736.1 |
2019 | 4 707.7 | 2 134.7 | 1 329.3 | 1 136.9 | 266.3 | 9 574.9 |
2020 | 4 191.6 | 1 122.5 | 1 004.1 | 1 085.7 | 240.3 | 7 644.2 |
2021 | 3 482.6 | 972.1 | 1 081.9 | 790.3 | 304.6 | 6 631.5 |
2022 | 3 782.6 | 993.9 | 1 410.2 | 627.9 | 137.4 | 6 952.0 |
Note: Totals may not add up due to rounding.
Download data file (Excel/CSV; 2.47 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 (2024) National Pollutant Release Inventory.
In 2022, 80% (5 542 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 67% (11 705 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 11% (1 975 kg), 9% (1 589 kg) and 9% (1 626 kg), respectively, to the decrease in releases.
Releases of lead to water by province and territory
Key results
- In 2022, Quebec, Ontario and British Columbia made up 87% (6 022 kg) of national lead releases to water
- Between 2003 and 2022
- the largest reduction in releases of lead to water was from Ontario, which reduced its releases by 5 736 kg (-69%)
- the largest increase in releases of lead to water was from Nova Scotia, which increases its releases by 133 kg (3 426%)
Facility-based lead releases to water by province and territory, Canada, 2003, 2012 and 2022

Data table for the long description
Province or territory | 2003 (releases to water in kilograms) |
2012 (releases to water in kilograms) |
2022 (releases to water in kilograms) |
---|---|---|---|
Newfoundland and Labrador | 1 670.0 | 522.2 | 73.5 |
Prince Edward Island | n/a | 3.3 | 7.8 |
Nova Scotia | 3.9 | 36.5 | 137.1 |
New Brunswick | 724.9 | 1 400.9 | 218.0 |
Quebec | 6 296.2 | 4 988.9 | 2 097.0 |
Ontario | 8 321.2 | 3 230.4 | 2 585.0 |
Manitoba | 1 385.0 | 162.9 | 124.3 |
Saskatchewan | 217.1 | 17.3 | 46.6 |
Alberta | 1 141.5 | 704.9 | 321.2 |
British Columbia | 4 563.9 | 2 979.4 | 1 340.0 |
Yukon | n/a | n/a | n/a |
Northwest Territories | n/a | 1.6 | 0.1 |
Nunavut | 15.0 | 5.5 | 1.5 |
Canada | 24 338.7 | 14 053.8 | 6 952.0 |
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 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. To access individual provincial data for all years 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 (2024) National Pollutant Release Inventory.
In 2022, lead releases to water were highest in Ontario, accounting for 37% (2 585 kg) of the national total. Ontario, Quebec and British Columbia accounted for 87% of national lead releases. However, these three provinces all had significantly lower lead releases in 2022 compared to 2003.
Ontario had the largest decline in lead releases between 2003 and 2022. 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 releases in 2022 represented 2% of the national total. The results in Nova Scotia were mostly due to releases from a single wastewater treatment facility.
In 2022, the largest source of lead releases to water by province and territory was:
- wastewater treatment in Nova Scotia, Prince Edward Island, Ontario, Manitoba, Saskatchewan, Alberta and British Columbia
- the pulp and paper industry in Newfoundland and Labrador, and New Brunswick
- mining and rock quarrying in the Northwest Territories and Nunavut
- other sources in Quebec
Between 2003 and 2022, reported releases of lead decreased in all provinces and territories, except Nova Scotia, Prince Edward Island and the Northwest Territories, the latter two of which had no reported releases of lead in 2003. However, New Brunswick had higher lead releases in 2012 compared to 2003. Following that increase, reported releases between 2012 and 2022 declined by 84%.
In 2003, there were no reported releases to the National Pollutant Release Inventory of lead in Prince Edward Island, Yukon nor the Northwest Territories. In 2012 and 2022, 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.
Key results
- In 2022, 190 facilities across Canada reported lead releases. Of these facilities:
- 54 facilities reported releases under 0.5 kilograms (kg)
- 122 facilities reported releases between 0.5 to 100 kg
- 14 facilities reported releases between 100 and 699 kg, which were located in Nova Scotia (1), Quebec (3), Ontario (7), Alberta (1) and British Columbia (2), accounting for 64% of total lead releases to water
Releases of lead to water by facility, Canada, 2022

Long description
The map of Canada shows the amount of lead in kilograms released to water in 2022 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 699 kilograms.
Navigate data using the interactive map
How this indicator was calculated
Source: Environment and Climate Change Canada (2024) 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.
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.
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.
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 2022, cadmium releases to water have declined by 56% or 2 756 kilograms (kg)
- In 2022, national releases totalled 2 188 kg
- the largest pathway was wastewater treatment facilities, representing about 54% (1 190 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 2022

Data table for the long description
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 | 2 935.8 |
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 |
2022 | 1 190.4 | 640.0 | 228.9 | 37.9 | 91.2 | 2 188.3 |
Note: Totals may not add up due to rounding.
Download data file (Excel/CSV; 2.38 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 (2024) National Pollutant Release Inventory.
In 2022, 84% (1 830 kg) of cadmium released to water came from wastewater treatment facilities and the pulp and paper industry.
Wastewater treatment contributed to 73% (2 005 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% (372 kg and 198 kg, respectively) to the total reduction in cadmium releases from 2003 to 2022.
The increase in releases of cadmium to water between 2015 to 2019 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 2022, Ontario, Quebec and British Columbia made up 86% (1 883 kg) of national cadmium releases to water
- Between 2003 and 2022,
- the largest reduction in releases of cadmium to water was from Quebec, which reduced its releases by 2 097 kg (-82%)
- the largest increase in cadmium releases to water was from Ontario, which had a 186 kg (22%) increase in releases
Facility-based cadmium releases to water by province and territory, Canada, 2003, 2012 and 2022

Data table for the long description
Province or territory | 2003 (releases to water in kilograms) |
2012 (releases to water in kilograms) |
2022 (releases to water in kilograms) |
---|---|---|---|
Newfoundland and Labrador | 8.4 | 2.5 | 9.9 |
Prince Edward Island | n/a | 0.3 | 3.2 |
Nova Scotia | 12.1 | 60.0 | 1.6 |
New Brunswick | 184.8 | 122.9 | 106.2 |
Quebec | 2 544.8 | 436.3 | 447.4 |
Ontario | 843.6 | 669.2 | 1030.0 |
Manitoba | 360.3 | 21.6 | 13.5 |
Saskatchewan | 31.8 | 0.9 | 0.9 |
Alberta | 258.3 | 351.6 | 170.0 |
British Columbia | 700.3 | 1 062.8 | 405.5 |
Yukon | n/a | n/a | n/a |
Northwest Territories | n/a | 0.2 | <0.1 |
Nunavut | 0.2 | 0.3 | 0.1 |
Canada | 4 944.6 | 2 728.4 | 2 188.3 |
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 (2024) National Pollutant Release Inventory.
In 2022, cadmium releases to water were highest in Ontario, accounting for 47% (1 030 kg) of the national total. Wastewater treatment was the main source of these releases.
Quebec had the largest decline in cadmium releases between 2003 and 2022 (-82%). This decline was mostly due to reductions in releases from wastewater treatment facilities. Ontario had the largest increase in releases over this period (22%).
In 2022, the largest source of cadmium releases to water by province and territory was:
- wastewater treatment in Prince Edward Island, Ontario and Saskatchewan
- the pulp and paper industry in Newfoundland and Labrador, New Brunswick, Quebec, Alberta and British Columbia
- mining and rock quarrying in Manitoba, the Northwest Territories and Nunavut
- other sources in Nova Scotia
Between 2003 and 2022, reported cadmium releases decreased in all provinces and territories, except Prince Edward Island, the Northwest Territories, Newfoundland and Labrador, and Ontario. The former two had no reported releases in 2003, and the latter two reported increases of 18% and 22%, respectively. Nova Scotia, Alberta and British Columbia had higher cadmium releases in 2012 compared to 2003. Following that increase, reported releases between 2012 and 2022 declined by 97%, 52% and 62%, respectively.
Yukon has never reported releases to the National Pollutant Release Inventory of cadmium to water. There were no reported releases of cadmium to water in Prince Edward Island or the Northwest Territories in 2003.
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.
Key results
- In 2022, 170 facilities across Canada reported cadmium releases. Of these facilities:
- 78 facilities reported releases under 0.5 kilograms (kg)
- 80 facilities reported releases between 0.5 to 40 kg
- 12 facilities reported releases over 40 kg, which were located in Quebec (3), Ontario (5), Alberta (1) and British Columbia (3), accounting for 62% of total cadmium releases to water.
Releases of cadmium to water by facility, Canada, 2022

Long description
The map of Canada shows the amount of cadmium in kilograms released to water in 2022 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.
Navigate data using the interactive map
How this indicator was calculated
Source: Environment and Climate Change Canada (2024) 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, as well as 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
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 2022. 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 2022. 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, 2012 and 2022, with 2022 being the most recent year with avaliable data and 2012 serving as a 10 year comparison. 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.
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 specialty 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 product manufacturing |
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 |
Oil and gas industry | Support activities for mining, and 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 2022, the latest year data was available and a 10-year comparison to the latest year, 2012.
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 years 2020 and 2021 were marked by the COVID-19 pandemic which had an impact ona wide range of economic sectors, especially the energy and transport sectors. The emissions change 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 20, 2024.
Environment and Climate Change Canada (2018) Moving toward using lead-free fishing tackle. Retrieved on June 18, 2024.
Environment and Climate Change Canada (2023) Using and interpreting data from the National Pollutant Release Inventory. Retrieved on June 18, 2024.
Environment and Climate Change Canada (2024) Bulk data files for all years – releases, disposals, transfers and facility locations. Retrieved on June 18, 2024.
Related information
NPRI sector overview: Aluminium
NPRI sector overview: Electricity
NPRI sector overview: Metal ore mining
Interactive figures
Updated August 2024
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 (2024) National Pollutant Release Inventory.
Download data file from the National Pollutant Release Inventory (Excel/CSV; 254 MB)
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