Most of the pollutants caused by extractive phase mining are exempt from the National Pollutant Release Inventory (NPRI).
The exemption for mining is for activities related to the actual removal of ore, rock or overburden, up to and including primary crushing. Releases and transfers of NPRI substances produced in the processing of rock ore, such as milling, concentrating, smelting and refining, are reportable.
In Canada, the NPRI is the means by which Canadians can access information about the pollutants released to the environment and transferred by companies in the their communities. It assists governments and other groups by identifying priorities for action to protect health and the environment in Canada.
In the United States, the Toxics Release Inventory or TRI, plays the same role. Since mining was added to the TRI in 1997, the mining industry has topped 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.
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 water and air. We say that their effects are cumulative and toxic, and the public has the right to know about them.
In the USA, Canadian-owned Barrick Goldstrike took the Environmental Protection Agency to court over this issue, and in April 2003 won a ruling that mine operators do not have to report trace minerals in waste rocks to TRI. The decision was based on a legal principle called de minimus – that the court should not be concerned with a triviality. The mining industry and its allies argue that the same ruling should apply in Canada.
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 to water. Under the regulations, a mine effluent that kills half the fish placed in it gets a passing grade, and some highly toxic substances such as cadmium are not on the list of regulated substances.
Some provinces have acts that regulate mining pollutant releases, but they cannot take the place of federal legislation.