Coppermine: tailings disposal facility leakage problem 1

[pimheinkool]

An old tailings dump is reclaimed using high pressure hydraulic monitoring. After being processed in an acid leaching plant the remaining tailings are pumped to a newly constructed tailings disposal facility (new tailings dam). Preliminary hydrogeological studies indicate a possible leakage of 2,000 m3/day at the facility. To me, this seems quite a lot. What do you think? Many thanks in advance!
Pimhein Kool

 

[cjohnson]

Depending upon many variables, yes this does sound like quite a lot of leakage. The size of impoundment, evaporation rates, type of bedrock, etc. will all affect the significance of such a leak. Regardless, this is still a good deal of water, and represents a potential loss of recoverable assests, and also a potential environmental threat. Furthermore, depending upon the nature of the leak, it may also pose a structural threat to the new tailings dam.

 

[knownot]

Potential environmental issues associated with leakage from an acidic tailings pond include depressed pH, elevated metals, although also possibly suspended solids in surface water.
Some possible ways to address this question include:
1. a site-specific evaluation of the potential environmental receptors, and likely impacts
2. an engineered solution to decrease permeability of the tailings pond bottom, buffer acidity in-place, capture leakage for treatment, or some combination of two or three of these.
Would need to know more about the site to be more helpful. Feel free to contact:
Ryan Legary (not necessarily endorsed by
Komex International Ltd.
Environmental and Engineering Consultants)
rlegary@calgary.komex.com