Water Conservation in the Mining Industry: Lessons for Zimbabwe

Water Conservation in the Mining Industry: Lessons for Zimbabwe

In Zimbabwe, the mining industry is at the heart of the socio-economic transformation agenda. However, mining-led growth without proper environmental management is not sustainable. This article focuses on water management developments in North America’s mining sector to raise public awareness on water management in Zimbabwe.

Mining has been a major industry in North America since the 19th century, although it has been present in one form or another from 1522 onward. Throughout that time, mining in the United States has exhibited a pattern of “rushes” as new minerals are discovered, with the most dramatic rushes happening at the discovery of gold deposits in the western half of the country.

The negative environmental impact of mining is widely accepted. Its aftereffects can include erosion, the formation of sinkholes, biodiversity loss, contaminated water and soil, and threats to human health.

Fortunately, the 21st century has seen an increased focus on sustainable mining practices in North America. In recent years, government regulation and cleaner production technology have worked in concert to reduce the environmental effects of mining, while still appeasing both business and governmental interests. It is important to note, however, that there is still a great deal of work to be done, and this is only a first step.

Water

Water is required at every stage of the mining process, and mining can result in water shortages when water is consumed, as well as the groundwater through acid rock drainage and heavy metal pollution (metals such as lead and cadmium in the mine dissolving into drinking water, making it undrinkable for humans). When water is diverted at mining sites, it can result in habitat loss for aquatic species, as well as water shortages for human and other industrial needs, especially in drier regions of North America.

In response to these issues, two mining companies in northern Canada have taken steps to put pollution controls in place. The two companies began a partnership with an independent environmental monitoring agency, CanNorth, that in regular water testing with the help of members of the community. In the last 20 years pollution from the mines has decreased, and the community and mining companies enjoy a mutually beneficial working relationship. (1)

Beyond this case study and across the country Canada leads the way in innovative water conservation practices. The mining industry accounts for the largest industrial use of water in that country. through Between 1996 and 2005, however, Canada reduced its water use in mining by 33%, at the same time as the value of production increased, leading to an overall decline in water intake per dollar of production. (2)

One of the most oft-cited recommendations for the reduction of water use is recycling and reusing water. Researchers from Columbia University’s Center on Sustainable Development in New York recommend that companies only consider disposal of water as a last resort, and promote waste water minimization through the below hierarchy. (3)
1. Avoidance
2. Reduction
3. Reuse
4. Recycling
5. Recovery of energy
6. Treatment
7. Containment
8. Disposal

Here in Zimbabwe, Zimplats is already engaged in water recycling, to the effect that they needed to abstract 9% less water in 2017 than 2016 from dams and underground. (For more information see Zimplats’ Annual Report, linked in “Other resources.”)

Case Study: mine in California, United States (4)

Old method: New method:
Huge amounts of freshwater pumped in. water used and up to 850 gallons of waste water produced per minute, had to be pumped miles away to evaporation ponds. Almost all initial freshwater brought in can be recycled. More than 120 acres of evaporation ponds can be eliminated and freshwater consumption reduced by 90%.

Conclusion: the need for government leadership
National governments can and should take leadership on water conservation in mining. Government regulation sets the stage for cleaner mining practice by mining companies. In recent decades, most countries have adopted environmental legislation prescribing limits on human impact on water.

The United States, for example, has implemented the following regulations. (5)
• Ground Water Rule: protects water against microbial pathogens in public water sources.
• Underground Injection Control Program: regulates wells that place liquids underground where they could pollute groundwater.
• Source Water Protection: ensures the quality of drinking water.

It is generally recognized that preventing contamination is more efficient and economically viable than reversing those effects later. With this in mind, government regulation leading to changes at the mining company is the most important thing that can be done to ensure clean, healthy water supplies for both human consumption and as a part of a healthy natural ecosystem.

Other resources
Zimplats Annual Report for Fiscal Year 2017: https://www.zimplats.com/data/2017/10/AR2017.pdf
The International Council on Mining and Minerals: https://w ww.icmm.com/en-gb
Image Sources
Image 1: 3 Paulina Szyplinska “CEO 360 Degree Perspective of the Global Mining Water and Wastewater Treatment Market,” Frost & Sullivan (May 11, 2012).
Image 2: Kauppila, Päivi & Räisänen, Marja & Myllyoja, S. (2011). Best environmental practices in metal ore mining. Finnish Environment. 29. 1-219.

1 Comment

  • Blessing tembani

    Government leadership definitely needed and also more engagement /awareness campaigns required. I simply seek to know whether Zimplats’ action was voluntary or as a matter of obligation.

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