WATER MANAGEMENT
> By Monique Simair
ten BEST
PRACTICES
for mine water treatment
C
anada’s mining industry is held to some of the world’s highest standards when it comes to protecting the environment. As a result, there is an ever-evolving desire to improve and implement best practices. Mine water treatment is a complex subject and selecting water treatment approaches requires consideration of many aspects. However, there are several current best practices that should be applied to all projects. Some of these have been used for decades, while others are emerging and aspirational. With decades of experience in mine water treatment and hundreds of discussions with proponents, consultants, regulators, and stakeholders, we have created a list of best practices that will be useful for everyone in the mining sector, regardless of your role.
one
Keep clean water clean, prevent contamination
While this may seem like common sense, it can be di cult to implement. ell known applications include diversion structures
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and contouring. It can also take the form of implementing covers and revegetation progressively during operations. The aspect of “prevent rather than treat” is a more recent addition to this best practice and involves application of in situ (in place) source control measures. Examples of well-known applications of this principal include adding pH buffering materials (such as lime) and using water covers to prevent oxygen from reaching tailings or waste rock and maintain neutral conditions. A more modern example is to implement redox buffering, using biological processes and biogeochemical interactions to buffer oxidation in pit lakes, tailings ponds, and underground mine pools. While these applications can also help to treat contaminated water, their application can also maintain conditions that prevent the contamination of water.
two
Use a site-specific approach
Gone are the days of out of the box ‘cookie-cutter’ type water treatment systems. We now know that each mine is totally
unique in its water quality and needs, and therefore requires a customized and site specific approach to water treatment. While traditional turnkey water treatment systems still have a role in the overall water treatment and water management strategy, it is now recognized that they work best as part of a bigger strategy. Some other considerations of a site specific approach include > End use of water > Water chemistry and constituents targeted for treatment > Lifespan of treatment system > Lead time for system operation > Constructable land area > Climate > Periodicity of treatment > Site infrastructure that can be repurposed (e.g., pit lakes, mine pools, tailings ponds) > Availability of local materials
three
Appreciate that water treatment changes with the mine life cycle
Water quality and volumes will change
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