OVERVIEW OF THE IMPACT OF MINING ON THE ... - IIED pubs

pH 8.5 8.3 8.8 8.7 8.8 8.9
TDS 439 721 566 1255 570 647
Ca 34 42 38 74 38 29
Mg 36 50 33 107 38 60
Na 18 29 74 145 63 60
K 0.3 1.6 2.5 2.8 2.5 2.7
Cl 7 20 88 101 55 55
F 0.1 0.1 0.2 0.2 0.1 0.1
SO4 11 8 28 544 53 53
Total Alkalinity 273 438 246 204 263 310
Cr 0.003 0.003 0.003 0.135 0.003 0.003
V 0.003 0.003 0.032 0.017 0.003 0.015
5.5.6 Implications for water quality and quantity management
The available evidence (Table 5.10) indicates that mining operations in the Steelpoort sub-catchment do have
adverse effects on water quality in the river systems. However, there does not appear to be a clear indication
(from these data) that the mines are contributing significant quantities of either chrome or vanadium to the
rivers. Instead, it is possible that there is “natural background contamination” by chrome and vanadium, as
reflected in the “upstream” samples.
The precise extent and nature of any contamination from mining activities in the Steelpoort sub-catchment
needs to be resolved unequivocally. There is considerable tension between farmers, irrigators and mine
operators in this region around allegations of various types of metal toxicity to crops and livestock and the
matter must be clarified as soon as possible. Concerted attention should be paid to a sampling and monitoring
campaign that must be designed to prove whether or not there is indeed any form of metal contamination and, if
so, the extent of such contamination and the precise source of such contamination. Only then can potential
management options be evaluated and implemented.
5.6 The Blyde sub-catchment
5.6.1 General description
5.6.1.1 Hydrology
This sub-catchment consists of the area drained by the Blyde River and its main tributary, the Ohrigstad River
(Figure 4.2). Both the Blyde and Ohrigstad rivers rise on the western slopes of the north-south trending
Drakensberg Mountains and flow northwards towards the escarpment edge where they join at the Blydepoort
Dam, which is located at the edge of the escarpment. From the Blydepoort dam, the Blyde River cascades
down a steep series of rapids to its lower reaches, where the river again flows northwards to join the Olifants
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