Reclamation of Abandoned Mining Sites: Some Examples
The MERN has invested $134 million since 2006 for reclamation, security, maintenance and monitoring of abandoned mining sites. In recent years, reclamation work has been done at some of these sites (Barvue, Eustis and Siscoe) in different regions of Québec. The MERN is currently inspecting these sites and performing environmental monitoring.Barvue (Abitibi-Témiscamingue)
Before:
- Zinc and silver deposit
- Open-pit and underground mining
- Operated from 1952 to 1957 and from 1985 to 1990
- 5 Mt of ore extracted
- 32-hectare acidogenic tailing site
- Major breach of the containment dike on the northern side of the tailings site in 1950
- 28-hectare tailing spill area on the banks of the Marcotte stream
Reclamation work:
- Work performed from 2012 to 2016
- Total cost of work: $35.5 M
- Stabilization and reshaping of the mine tailings site containment dike
- Partial diversion of the Marcotte stream for construction of a berm
- Excavation of 400,000 m3 of mine tailings from the banks of the Marcotte stream
- Creation of two multi-section retention ponds
- Installation of a multi-layer cover with geomembrane to limit water inflow and reduce oxidation of the tailings, thereby limiting contamination of the receiving environment
- Revegetation over the entire site, with use of fertilizing residuals
- Installation of instruments for post-closure environmental monitoring
Reclaimed site:
Eustis (Estrie)
Before:
- Copper deposit
- Hillside and underground mining
- Operated from 1865 to 1939
- 3 Mt of ore extracted
- Waste rock stack
- 3 acidogenic tailings sites covering a total area of 20 hectares
Reclamation work:
- Work performed from 2008 to 2010
- Total cost of work: $6.7 M
- Installation of a multi-layer cover with geomembrane to limit water inflow and reduce oxidation of the tailings, thereby limiting contamination of the receiving environment
- Experimental de-inking sludge cell (pulp and paper mill)
- Revegetation over the entire site
- Installation of instruments for post-closure environmental monitoring
Reclaimed site:
Siscoe (Abitibi-Témiscamingue)
Before:
- Gold deposit
- Underground and open pit mining
- Operated from 1926 to 1949
- Roughly 3.5 Mt of ore extracted
- Two mine tailings sites covering a total area of 30 hectares
Reclamation work:
- Work performed from 2014 to 2015
- Total cost of work: $2.1 M
- Levelling of tailings site
- Digging of ditches to improve surface drainage
- Installation of a single-layer granular covering
- Revegetation over the entire site
- Installation of instruments for post-closure environmental monitoring
