Third national assessment
- Executive Summary
- 1.0 Introduction
- 2.0 Methods
- 3.0 Presence or Absence of Effects
- 4.0 Effluent Quality
- 5.0 Biological Monitoring Studies Investigating Observed Effects
- 6.0 Key Findings
- 7.0 Glossary
- 8.0 References
- Appendix A: Metal Mines Subject to the Metal Mining Effluent Regulations in 2013
- Appendix B: Effect Indicators, Critical Effects Sizes and Studies Conducted
- Appendix C: Mine-by-Mine Results of Studies Assessing Potential Effects
- Appendix D: Fish Tissue Mean Total Mercury Concentrations per Mine
- Appendix E: Trends in Sublethal Toxicity
- Appendix F: Trends in Sublethal Toxicity for Ore Types
- Appendix G: Annual Mean Concentrations of Effluent Characterization Data
- Appendix H: Mine-by-Mine Summary of Investigation Studies
Appendix H: Mine-by-Mine Summary of Investigation Studies
Table H1. Mine-by-mine summary of investigation of cause (IOC) and magnitude and geographic extent (M&E) studies
na - assessment of far-field effects was not available because the M&E assessment was based on existing data or was not possible due to confounding factors in the receiving environment.
a - ongoing IOC study (first 3-year study of two-part study completed)
| Mine code | Components with confirmed effects | Causes determined As stated in Study Reports submitted to Environment and Climate Change Canada | M&E study results – at least 1 confirmed effect observed in far-field? |
|---|---|---|---|
| BM5, BM6, BM11 | fish habitat | Subtle effluent-related effect in 2 of 3 exposure areas; effluent-related effect not identified in 1 exposure area | na |
| BM10, BM27 | fish habitat and fish | Mine-related exposure to metals; most likely contaminants of concern are cadmium, copper, iron, selenium, and zinca | Yes (fish habitat and fish) |
| BM14 | fish habitat | Elevated cadmium, selenium, and zinc in water and sediment from effluent discharge | Yes |
| BM19 | fish habitat | Multiple stressors from both historical impacts and current activities in watershed; non-point sources downstream from effluent discharge are main source of metal loadings | Yes |
| PM2, PM11 | fish habitat and fish | Effects on benthic community likely related to high metal concentrations in water and sediments; further study needed to determine relative importance of current mine effluent vs. historical mine wastea | Yes (fish) |
| PM14 | fish habitat and fish | Effects on fish and fish habitat may be related to nitrogen compounds in effluenta | na |
| PM25 | fish | Effects may be related to nutrient enrichment caused by nitrogen compounds and total suspended solids in effluent | na |
| PM29 | fish | Potential causes: elevated copper level in water, differences in fish hatch times between sampling areas | na |
| PM30 | fish | Potential causes: ammonia and nitrate in mine effluent, mine-related copper in sediments, and/or hydrocarbons in sediment | na |
| PM36 | fish habitat and fish | Effluent-induced meromixis due to high total dissolved solids causing low dissolved oxygen and low productivity in exposure area | yes (fish habitat) |
| U1 | fish habitat | Effects may be related to trace elements in sediment and/or water; weight-of-evidence approach did not identify a single exposure route (current mine effluent or sediment) as the primary pathway for contaminant exposure in the benthic community | yes |
| FeTi1 | fish habitat and fish | Benthic effects attributed to smothering of habitat with Fe-rich colloidal material; fish effects related to reduced food availability resulting from impacts to benthic community | yes (fish habitat and fish) |
| O3 | fish habitat and fish | Exposure to elevated chloride, salinity, total Suspended solids, ammonia and nitrate in effluent | no |
| Mine code | Components with confirmed effects | Causes determined As stated in Study Reports submitted to Environment and Climate Change Canada | M&E study results – at least 1 confirmed effect observed in far-field? |
|---|---|---|---|
| BM3 | fish habitat and fish | Benthic effects associated with ongoing impacts of historical streambed/floodplain sediment contamination on pH and metal concentrations; some effects may be related to elevated major ions, strontium, and thallium in mine effluent | yes (fish habitat) |
| BM4 | fish habitat and fish | Benthic effects likely caused by waterborne exposure to metals in effluent, most notably zinc; further study required to assess cause of fish effects; natural variability may be a more likely cause than metal exposurea | yes (fish) |
| Mine code | Components with confirmed effects | Causes determined As stated in Study Reports submitted to Environment and Climate Change Canada | M&E study results – at least 1 confirmed effect observed in far-field? |
|---|---|---|---|
| PM35 | fish habitat and fish | Potential causes: major ions, nutrient enrichment, trace metals, natural variabilitya | yes (fish habitat) |
| Mine code | Components with confirmed effects | Causes determined As stated in Study Reports submitted to Environment and Climate Change Canada | M&E study results – at least 1 confirmed effect observed in far-field? |
|---|---|---|---|
| BM1 | fish habitat and fish | No evidence that current effluent causes effects; fish effects indicative of natural variability between exposure and reference areas | yes (fish) |
| BM20 | fish habitat | Effects may be related to major ions (chloride, sulphate, sodium, calcium) in mine effluent and current or historical sediment contamination (nickel) | na |
| PM3 | fish | Major ions (chloride, sulphate) and/or nutrients (nitrate, ammonia) in mine effluent | na |
| U3 | fish habitat | Natural variability in habitat between sites; possible influence of natural or mine-related nutrient enrichment and mine-related contaminants | yes |
| U4 | fish | Elevated concentrations of major ions in mine effluent and slightly elevated water temperatures in exposure area may have contributed to stimulatory response | yes |
| U5 | fish habitat and fish | Benthic effects related to increased concentrations of major ions (calcium, sodium, potassium, sulphate, chlorine) in exposure area; fish effects most likely related to differences in habitat quality and prey availability (non-effluent related) | yes (fish habitat) |
| O4 | fish habitat | Nutrient enrichment (phosphorus) from mine effluent | yes |
| Mine code | Components with confirmed effects | Causes determined As stated in Study Reports submitted to Environment and Climate Change Canada | M&E study results – at least 1 confirmed effect observed in far-field? |
|---|---|---|---|
| PM1 | fish habitat and fish | No strong indication of eutrophication or toxic substances causing effects in exposure area | yes (fish habitat) |
| PM21 | fish habitat and fish | Effects likely caused by nitrate and ammonia in mine effluent | yes (fish habitat) |
| Mine code | Components with confirmed effects | Causes determined As stated in Study Reports submitted to Environment and Climate Change Canada | M&E study results – at least 1 confirmed effect observed in far-field? |
|---|---|---|---|
| PM28 | fish habitat and fish | Cause not yet determined; effects may be related to nutrient enrichment caused by nitrogen compounds in effluenta | no |
| Mine code | Components with confirmed effects | Causes determined As stated in Study Reports submitted to Environment and Climate Change Canada | M&E study results – at least 1 confirmed effect observed in far-field? |
|---|---|---|---|
| U2 | fish habitat and fish | Combined influence of nutrients and major ions may be related to increased fish growth | yes (fish habitat) |
| FeTi2 | fish habitat and fish | Cause not yet determined; iron and nitrogen compounds identified as potential causes to be further investigateda | na |
| Mine code | Components with confirmed effects | Causes determined As stated in Study Reports submitted to Environment and Climate Change Canada | M&E study results – at least 1 confirmed effect observed in far-field? |
|---|---|---|---|
| BM2 | fish habitat | Effects may be related to major ions (e.g., chloride, sulphate, sodium) and nitrogen in mine effluent, and trace metals (nickel) in mine effluent and sediments | na |
| BM18 | fish habitat | Phosphate in mine effluent | na |
| PM4 | fish habitat | Effect likely caused by mine activities, including elevated major ions in mine effluent and trace metals in sediment; some variation in benthic communities may be related to natural habitat differences | na |
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