Status report on the performance of mines subject to the Metal and Diamond Mining Effluent Regulations in 2019: Executive summary

This report presents a summary of the performance of Canadian mines in 2019 with respect to the prescribed limits and requirements of the Metal and Diamond Mining Effluent Regulations (Regulations). The annual report provides information on mines subject to the Regulations, effluent data, compliance performance and water bodies designated as tailing impoundment areas.

The statistics contained in this report are provided to Environment and Climate Change Canada by owners and operators of mines. The Regulations require that owners or operators report information to Environment and Climate Change Canada, including:

• concentrations for deleterious substances including metals, cyanide and total suspended solids
• pH of effluent
• effluent volume and
• summary results of fish acute lethality tests and Daphnia magna monitoring tests

In 2019, 5 diamond mines and 143 metal mines in Canada were subject to the Regulations. During the year, 4 mines became subject to the Regulations and 5 mines became a recognized closed mine. It was determined that 10 mines subject to the Regulations did not provide one or more monitoring reports. Compliance with prescribed monthly mean limits for metals, cyanide, total suspended solids, and the authorized pH range is reported in the Metal and diamond mining effluent quality indicator. The total number of exceedances for deleterious substances and pH reported by mines was 240. Mines reported 41 acute lethality test failures for fish and 95 Daphnia magna monitoring test failures.

Schedule 2 of the Regulations lists water bodies designated as tailings impoundment areas. In 2019, two water bodies frequented by fish were listed in Schedule 2 of the Regulations as tailings impoundment areas.

The Regulations are enforced by Environment and Climate Change Canada in accordance with the Compliance and Enforcement Policy for the Habitat Protection and Pollution Prevention Provisions of the Fisheries Act.

The complete electronic version of this status report is available through Environment and Climate Change Canada’s online publications catalogue at Government of Canada Publications website. For the complete dataset, visit the Metal and Diamond Mining Effluent Regulations compliance data webpage.

More information on the Regulations is available on the Metal and diamond mining effluent webpage.