Releases of Lead to Water
Lead (Pb) is a metal that occurs naturally in the Earth’s crust and is used in industrial manufacturing. Lead can be released directly to water from human activities like production of pulp and paper and processing of metals, and from wastewater treatment plants.
Exposure to Pb, even in small amounts, can be hazardous to both humans and wildlife. Lead is listed as toxic[1] according to the Canadian Environmental Protection Act, 1999 (CEPA 1999).
In 2011, 17 027 kilograms (kg) of Pb were released to water. This represents a decrease of 10%, or 1860 kg, below the 2010 release level and 30%, or 7312 kg, lower than in 2003, the baseline year of our time series.
The decrease in the amount of lead released to water between 2010 and 2011 is mostly attributable to lower lead releases from wastewater treatment plants in Ontario and British Columbia. The long-term decline between 2003 and 2011 can be explained mostly by reductions in the releases in the sectors of wastewater treatment and metal ore mining.
Releases of lead to water, Canada, 2003 to 2011
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How this indicator was calculated
Note: The indicator only includes the kilograms of Pb, including that released in substances containing Pb, reported in the National Pollutant Release Inventory (NPRI) based on the NPRI reporting criteria for releases of Pb and its compounds. As a result, the Pb releases represent only a portion of the releases of this toxic pollutant to water in Canada.
Source: Environment Canada (2013) National Pollutant Release Inventory Online Data Search - Facility Reported Data.
Sources of releases of lead to water
Water, sewage and other systems account for 53% (8975 kg) of the total Pb released nationally in 2011. The second-largest amount of Pb came from waste effluents from pulp, paper and paperboard mills, representing 17% (2883 kg) of the national total. The metal ore mining industry released the third-largest amount to water, with 11% (1818 kg) of the national total.
Releases of lead to water by source, Canada, 2011
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How this indicator was calculated
Note: The indicator only includes the kilograms of Pb, including that released in substances containing Pb, reported in the National Pollutant Release Inventory (NPRI) based on the NPRI reporting criteria for releases of Pb and its compounds. As a result, the Pb releases represent only a portion of the releases of this toxic pollutant to water in Canada.Categories follow the North American Industry Classification System (NAICS), except “Other Sources,” which represents a group of sources for which releases are not individually mentioned in this chart.
Source: Environment Canada (2013) National Pollutant Release Inventory Online Data Search - Facility Reported Data.
Releases of lead to water by province and territory
Ontario facilities contributed the most to national releases of lead in 2011, with 41% (6901 kg) of the national total. Wastewater treatment plants and metal ore mining facilities were among the biggest sources in Ontario. Quebec facilities came second, contributing 20% (3422 kg) of the national total. The releases in Quebec originated mainly from a wastewater treatment plant, pulp and paper mills, and a ferro-alloy manufacturing plant. British Columbia ranked third, with 17% (2872 kg) of the national total. More than 70% of British Columbia’s releases came from a non-ferrous production and processing plant and two wastewater treatment plants.
Releases of lead to water by province and territory*, Canada, 2011
View data for this chart
How this indicator was calculated
Note: The indicator only includes the kilograms of Pb, including that released in substances containing Pb, reported in the National Pollutant Release Inventory (NPRI) based on the NPRI reporting criteria for releases of Pb and its compounds. As a result, the Pb releases represent only a portion of the releases of this toxic pollutant to water in Canada.
* No facilities in Yukon reported Pb releases to the NPRI in 2011.
Source: Environment Canada (2013) National Pollutant Release Inventory Online Data Search - Facility Reported Data.
Related indicators
Other information
[1] Section 64 of CEPA 1999 defines a substance as toxic if it is 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.
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