The Public Has a Right to Know the Toxins Produced by Mining

Jamie Kneen

National Program Co-Lead

Most of the pollutants released by the creation of tailings and waste rock during mining are exempt from the National Pollutant Release Inventory, the NPRI.

Digging up metals generates enormous piles of rock, which contain trace amounts of potentially harmful substances. As an example, one gold wedding ring produces anywhere from 6-20 tonnes of waste rock and tailings. Waste rock is unprocessed rock that has been broken into pieces to facilitate its removal; tailings are the processed finely ground rock created by extracting ore. In Canada, they are usually highly acidic, leaching sulphuric acid into waters and aquifers. They can contain arsenic, mercury, copper, nickel, selenium and other toxic substances. Tailings (also called slimes) are usually kept in impoundments of immense size, which have to be monitored in perpetuity. In Canada, mining creates almost 2 million tons of waste rock and tailings a day.

In Canada, the NPRI is the means by which Canadians can find information about the pollutants transferred by companies and released to the environment in their communities. It helps government and other groups by identifying priorities for action to protect health and the environment in Canada. It is part of the Canadian Environmental Protection Act.

In the United States, the Toxics Release Inventory, or TRI, plays the same role. When mining was added to the TRI in 1997, the mining industry suddenly moved to the top of the list of polluters, contributing over half the 7.77 billion pounds of toxic chemicals released to the environment. Most of the pollutants came from the waste rock and tailings that are created at the mine site.

However, in 2002, because of lawsuits by Barrick Gold and the National Mining Association, most of the pollutants from waste rock were removed from the inventory. A US federal court ruled that many substances need not be reported if they make up less than 1 percent of the weight of the waste rock pile. But those trace amounts add up to 1.5 billion pounds in the United States.

For a number of years now, a struggle has been taking place in Canada between the mining industry and organizations that care about public health to get mining wastes and tailings included in the NPRI. The mining industry argues that low concentrations of toxins in waste rock and tailings occur in nature and are therefore not “releases to the environment”. MiningWatch and other groups argue that removing the rock from the ground and crushing it exposes more chemicals to air and water and releases them into the environment. We say that their effects are cumulative and toxic, and the public has the right to know about them.

The industry also argues that the new Metal Mining Effluent Regulation captures releases from mine sites. In reality, the MMER reports releases of only a limited number of substances, only to water, and only after they have left the company property.

For more information: call MiningWatch Canada at (613) 569-3439 or e-mail joan(at)

Include all mining toxins in the National Pollutant Release Inventory.
The public has a right to know.

Write or call your Member of Parliament and let him/her know what you think.
Submit your comments to the CEPA review by e-mail: [email protected]