Government battling to comply with its own legislation at derelict mine sites - 18 January 2008
These days ‘hazard’ signs could well be erected alongside rivers and dams that were once the play places of children and the survival mechanism for many fauna and flora species.
Unlike the days when river water was crystal clear and river sand snow white, green sludge and discoloration are currently the order of the day.
In several water ways, fish are no longer able to survive and even mammals and predators are succumbing to pollution. Nico Bezuidenhout, who chairs the Water Institute of Southern Africa mine water division and who is also business leader of the environmental technology unit at Golder Associates Africa, says that South African water preservation legislation has reached a point where appropriate guidelines and laws are in place to protect the water resource.
The problem is that the State enforcement of water legislation is limited, owing to a lack of capacity in regulatory institutions to manage and control what is taking place at the mines, he tells Mining Weekly.
Bezuidenhout, who is also an associate geochemist, specialising in acid-rock drainage (ARD) and industrial waste work at Golder Associates, adds that most large mining companies are reverting to self-regulation, while others, often smaller operators, see lack of enforcement as a noncompliance gap.
Many defunct mines, which have become the responsibility of the government, are significant contributors to waste loads flowing into South African river systems.
“After many years of mining practitioners not practicing environmentally safe mining, we today live with the consequence, and all the waste sites related to the historical mining of sulphide orebodies will cause pollution from ARD processes, ceaselessly,” he says.
He adds that government resource limitations are playing a major role in its inability to manage defunct mines. The mine sites are often large, and a substantial amount of money is needed to mitigate ARD at these sites.
“Government is in the position where it enforces legislation at operating mines and finds it difficult to comply with the legislation at the derelict mine sites, for which it is responsible,” he states.
In Africa, there is a perception that different water-treatment standards are being applied to local mining operations than to internationally linked mining operations. International com- panies are applying stricter standards, but, because these operational standards cost more, smaller local mining operators have substandard water management.
ARD and metal leaching (ML) can be found at mining wastelands, which include waste rock and processed ore, and at mining workings, such as openpits and underground workings.
The large volumes of water that operating mines use to process and extract ore are prone to coming into contact with ARD processes and the chemicals used for ore extraction. Water is also imported when rain falls onto mine sites.
Water quality is also impacted at the intersection of mining operations with ground- water systems.
“Mine water chemistry is influenced by a number of processes, of which ARD and ML processes are arguably the biggest.
“A large challenge is that a lot of the mining industry is concentrated in particular catchments, which makes the cumulative effects on the water resource substantial,” Bezuidenhout says.