Amendments to the Metal and Diamond Mining Effluent Regulations

1. What is the purpose of these amendments

The purpose of the amendments to the Metal Mining Effluent Regulations (MMER) is to reduce threats to fish and their habitat by improving the management of harmful substances in metal and diamond mining effluent.

2. What are the key elements of these amendments

The main changes include lower limits for the harmful substances listed in Schedule 4. The changes also add a new substance to this list and new rules for acute toxicity. Additional changes improve the efficiency and efficacy of the Environmental Effects Monitoring, and expand the scope of the Regulations to include diamond mines.

3. How do these amendments affect Canadian businesses

These amendments add new requirements on diamond mining operations, such as:

  • possible installation of new treatment equipment or modified techniques to meet the new limits;
  • maintaining and calibrating treatment and monitoring equipment and keeping maintenance records;
  • conducting weekly effluent testing and monthly acute lethality testing;
  • submitting quarterly and annual reports containing effluent data and monitoring results;
  • notifying an inspector if a test result indicates non-compliance with the regulations;
  • submitting details on final discharge points and design-rated capacity;
  • preparing an emergency response plan and making it available on-site to those who would implement the plan;
  • complying with requirements for environmental effects monitoring studies; and
  • keeping records available for inspection.

The amendments contain changes for metal mining operations, including:

  • additional requirements for acute toxicity testing;
  • possible installation of new treatment equipment or modified techniques to meet the new limits;
  • weekly testing of a new substance and reporting of results;
  • submitting additional information on mine operations, including the design-rated capacity; and
  • complying with the new and modified components of the environmental effects monitoring requirements.

4. When will these changes be implemented

Some amendments to the Metal Mining Effluent Regulations will be implemented when it is published in Canada Gazette II. Other changes will be phased in over several years, and some will apply only to mines beginning or re-starting operation after a date specified in the amendments.

5. Where can I get more information

Mining and Processing Division
Environmental Protection Branch
Environment and Climate Change Canada

351 St. Joseph Boulevard, 18th Floor
Gatineau QC K1A 0H3


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