New Acartia tonsa test for marine effluent

Summary#

These are final regulations that amend the Metal and Diamond Mining Effluent Regulations (MDMER). They add a new test method using the marine invertebrate Acartia tonsa (the Reference Method STB 1/RM/60) to check whether salty mine effluent put into the ocean is acutely lethal. Most of the changes take effect on December 1, 2021 (some small parts came into force on registration day, June 10, 2021).

What it does#

• Requires owners/operators to test monthly grab samples of effluent for acute lethality (kills more than 50% of test organisms) using fish and an invertebrate, following the prescribed reference methods.
• Adds a specific rule that if effluent salinity is greater than 4 parts per thousand and it is discharged to marine waters, the invertebrate test must use Acartia tonsa and the procedures in Reference Method STB 1/RM/60.
• Keeps existing fish test rules (rainbow trout or threespine stickleback) depending on salinity and receiving waters.
• Adds or updates record-keeping and reporting requirements, including reporting the date, location and the percentage mortality found in each 100% effluent test. Annual reports must be submitted by March 31 each year.
• Makes a few technical fixes: aligns thresholds with reference methods, corrects place names in schedules (e.g., “Hamlet of Cambridge Bay”), and cleans up French wording.

Who's affected#

• Mine owners and operators who discharge effluent into marine waters, especially those whose effluent has salinity above 4 parts per thousand. The government says this currently applies to two mines in Nunavut (both owned by the same company).
• Laboratories that perform acute lethality testing will need to offer the Acartia tonsa test and may see new business from it.
• Environment and Climate Change Canada will collect and manage the additional test data and do compliance work.

Why it matters#

• The new test targets marine invertebrates. These organisms are a key part of the food web and are important for local fisheries and communities that rely on marine food sources.
• It gives regulators a clearer, science-based way to check whether salty mine effluent harms marine life before allowing deposits to continue.
• The government estimates the present-value cost of these changes at about $357,500 over 10 years (roughly $190,600 to industry and $166,900 to the federal government). Laboratories charge about $880 per test (shipping extra).
• The main change is practical: if your mine discharges saline effluent to the ocean, you will need to run the Acartia tonsa test and report results starting December 1, 2021.