Acid Mine Drainage(AMD) is the second biggest environmental threat in the world. It occurs when water flows over or through sulphur bearing materials forming solutions of net acidity. It mainly comes from abandoned mines and currently active mining.
AMD is formed when Pyrite, an iron sulfide is exposed and reacts with air and water to form sulphuric acid and dissolved iron. The iron can precipitate to form the red, orange or yellow sediments in the bottom of streams containing mine drainage. The acid runoff further dissolves heavy materials such as copper, lead, mercury into the ground waters.
Speaking to John Jagero, an expert in water and environmental matters said “With all these metals contaminating water, it makes it unsafe for human consumption and also disrupts growth and reproduction of aquatic plants and animals.” He also added that AMD has corroding effect of acid on parts of infrastructure such as bridges.
Following the Kenya Mining Bill that is currently being drafted to conform to the new constitution, adequate measures are expected to be developed to avoid AMD occurrence. Coal mining in Kenya is a key component of the country’s development of the blueprint Vision 2030, when Kenya is expected to join the countries with middle economies. However, before these mining activities are put to effect, the government is expected to carry out proper environmental impact assessment to avoid conflicting with the community and putting them at risk of using contaminated water.
Question is, does this conform with the current award to a Chinese company to mine coal in Kitui? With the knowledge of scarcity of water in Ukambani, how will the company avoid AMD since mines are supposed to be developed in a manner which utilizes gravity drainage to avoid excessive water accumulation in the mines.
From a global outlook, it has been confirmed that after more than a century of intense mining activities in South Africa, parts of Witwatersrand basin already has risks of spillage flows into Wonderfonteinspruit and Tweelowpiespruit, which will threaten the Krugersdrop game reserve and the cradle of human kind. The Robinson dam is now said to be radioactive with uranium levels 40,000times higher than normal levels and is said to glow in the dark.
On the same, at the central basin, the ERPM Company ceased pumping water in 2008. As of September 2010 the water level was 545m below the surface with an average daily rise over the past year. The danger is that millions of liters could be seen of highly acidic mine water rising up under Johannesburg, and if left unchecked, it could spill out into the streets as early as this year (2012)
Given the foregoing, it is imperative for the companies charged with mining to apply mining methods which are eco-friendly to neutralize acidity and remove heavy metals to reduce AMD, however on affected mining sites, long term solutions are to be adopted like treating water for indirect use. If mining activities are left unchecked, the result could be hazardous.
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