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

Water quality data for three sites along the Mogalakwena River (upper, middle and lower reaches of the subcatchment)
were obtained from the Department of water Affairs and Forestry. These data are presented in
Table 4.20, below.
Table 4.20: Average values for selected water quality constituents in the upper, middle and lower reaches of
the Mogalakwena River. (All data presented as mg/litre, except electrical conductivity (milliSiemens/metre) and
pH values).
River Reach
Parameter
Upper Middle Lower
Electrical Conductivity 34.5 26.3 32.0
pH 7.5 7.6 7.9
Total Dissolved Salts 266 216 261
Ca 23 28 25.1
Na 33 14 32.1
K 5.8 2.6 6.4
F 0.3 0.3 0.3
Cl 30 9.6 48.4
SO4 8.7 4.0 3.4
4.18.6 Implications for water quality and quantity management
The available evidence suggests that the only likely source of any impact on local water resources and water
quality would be the Potgietersrus Platinum Mine and its associated processing plants and tailings dams.
These impacts would most likely consist of localized acid mine drainage linked to the oxidation of sulphide
minerals. In addition, the Rustenburg Platinum Mine and the other operating and closed or abandoned mining
operations can be expected to contribute increased quantities of suspended solids to local streams and rivers
during and after rainfalls.
4.19 The Setoka-Soutsloot sub-catchment
4.19.1 General description
4.19.1.1 Hydrology
This sub-catchment consists of the area drained by several small seasonal and episodic streams, and is located
between the Mogalakwena and Sand sub-catchments (Figures 4.2 and 4.3). These stream systems all flow
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