Mining and Environment Management
Zimbabwe is endowed with rich mineral deposits, dominated by two prominent geological features namely the great dyke and ancient Greenstone Belts also known as Gold Belts. The nation has seen an increase in the number of mining activities in recent years, both small and large scale. On a positive note, mining activities are coupled with employment creation, revenue generation and community projects. However, mining inevitably impacts negatively on the environment disturbing the landscapes and ecosystems thereon.
Can Mining become environmentally sustainable?
Mining can become more environmentally friendly through developing and integrating practices that reduce the adverse environmental impact of mining operations. Such good practices include; reducing inputs that include water and energy consumption, minimizing land disturbance, and waste production, preventing soil, water, and air pollution at mine sites, and conducting successful mine closure and reclamation activities.
Water is used in a number of applications at mine sites. By diverting surface water and pumping groundwater, mining operations can reduce both the quantity and quality of water available downstream for aquatic ecosystems and other industrial and municipal water users, especially in areas with arid climates. Closed water system whereby effluent water is drained, collected and reused or recycled reduces demand for fresh water and minimizes
Mining and metal processing can be hyper energy-intensive. Some examples of ways mining companies are reducing their energy consumption include reliance on renewable and clean energy sources such as solar and wind.
Mining activities use land at every stage of its cycle; exploration, construction, operation, closure, and post-closure. Vegetation is cleared for the construction of buildings, roads, and power lines, open pits or tunnels are dug to gain access to the ore, and waste storage facilities such as tailings ponds are expanded over the life of the mine, potentially leading to habitat loss and deforestation.
To reduce the land-use impacts of mining, miners can reduce, the overall footprint of the mining area, minimize the amount of waste produced and stored, maintain biodiversity by transplanting or culturing any endangered plants found on site, and plan mines processing plants around existing infrastructure wherever possible.
Mine waste includes solid waste, mine water, and air particles, which can vary significantly in their composition and potential for environmental contamination. In addition to preventing soil, water, and air pollution, waste management plans are required in order to select and design appropriate storage facilities for the large volumes of waste produced at most mine sites.
It is generally recognized that preventing pollution is more effective at reducing environmental impacts and economic than cleaning it up later on. Methods for minimizing and eliminating wastes in the production of minerals and metal commodities include:
Using cleaner production techniques
Using waste as raw material, and
Reducing the amount of waste produced through process re-engineering.
Water management strategies are used to reduce the volume of waste water produced, and if necessary, to treat it to an acceptable quality before it is released.
What legislation promotes environmentally sustainable mining?
In Zimbabwe, the Environmental Management Act (CAP 20:27) of 2002 is the legal framework for environmental management and mining is prescribed as an activity where an environmental impact assessment is mandatory before such a project commences implementation. All miners should go through the Environmental Impact Assessment (EIA) process which is an assessment for the purposes of identifying, predicting, evaluating and mitigating the biophysical, social, and other relevant effects of mining development proposals prior to major decisions being taken and commitments made. In addition, the same law regulates mine waste disposal; solid, liquid and gas, controlling how waste can be discharged into the environment.