Lead Releases 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 in wastewater from human activities like sewage treatment, production of pulp and paper, and processing of metals.
Exposure to lead, 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 2010, 18 886 kilograms (kg) of Pb was released to water, an increase of 15%, or 2 424 kg, above the 2009 release level and 22% or 5 453 kg lower than in 2003, the baseline year of our time series.
The increase in the amount of lead released to water between 2009 and 2010 is mostly attributable to higher lead releases from wastewater treatment plants in Ontario. The long-term decline between 2003 and 2010 can be explained mostly by reductions in the sectors of wastewater treatment, metal ore mining, and non-ferrous production and processing.
Lead release to water, Canada, 2003 to 2010
Note: The indicator includes releases only from the facilities that reported to the National Pollutant Release Inventory (NPRI).
Source: Environment Canada (2012) National Pollutant Release Inventory.
Sources of lead releases to water
Water, sewage and other systems released 63% (11 973 kg) of the total Pb released nationally in 2010. The second-largest amount of Pb came from pulp, paper and paperboard mills, representing 11% (2 117 kg) of the national total. The non-ferrous production and processing (excluding aluminum) industry released the third-largest amount to water with 8% (1 552 kg) of the national total.
Lead release to water by source, Canada, 2010
Note: The indicator is calculated using data from the National Pollutant Release Inventory (NPRI) from facilities that are required to report based on the NPRI reporting criteria for Pb to water. 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 (2012) National Pollutant Release Inventory.
Lead releases to water by province and territory
Ontario facilities contributed the most to national releases of lead in 2010, with 52% (9 901 kg) of the national total. Wastewater treatment plants and some non-ferrous foundries were among the biggest sources in Ontario. British Columbia facilities came second, contributing 19% (3 543 kg) of the national total, more than 70% of which came from a non-ferrous production and processing plant and two wastewater treatment plants. Quebec ranked third, with 18% (3 385 kg) of the national total. The releases in Quebec originated mainly from a wastewater treatment plant and a ferroalloy manufacturing plant.
Lead release to water by province and territory, Canada, 2010
Note: The indicator includes only the releases reported to the National Pollutant Release Inventory (NPRI) from facilities that are required to report based on the NPRI reporting criteria for Pb to water. No facilities in Prince Edward Island or Yukon Territory reported Pb releases to the NPRI in 2010.
Source: Environment Canada (2012) National Pollutant Release Inventory.
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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