3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item Impacts of a defunct colliery on water quality of the Wasbank river, UMzinyathi Municipality, KwaZulu-Natal(2019) Nyath, Linah ThobekileThe inefficiency of South Africa’s previous legislation that regulated the operation and closure of mining activities, has resulted in too many mines being abandoned without adequate rehabilitation (Naidoo, 2017). Therefore, currently, the State has taken a responsibility to identify all these abandoned mines, assess and rehabilitate them in order to mitigate their environmental impacts, mainly the acid mine drainage (AMD) impacts. A defunct colliery in Glencoe, which ceased its operation in 1973, is one of the mines that was identified as an abandoned mine. This mine is located on the upper Wasbank catchment area in KwaZulu-Natal and study was conducted in order to determine whether this defunct colliery has any negative effects on the water quality of this catchment area. A zone above the mine shaft of the defunct colliery was identified and considered as a pristine zone, which was then used as a reference zone, and three more zones were identified, adjacent and below the mine shaft, named sampling zone B, C and D in order to assess the trend of water quality indicators and therefore to determine whether the defunct colliery is contaminating this catchment area or not. Each zone had distinct sampling points within the zone, ranging from one to four sample points per zone. Water quality of this catchment area was tested on a monthly basis during the wet season (December 2017 to March 2018) and the dry season (April 2018 to July 2018). The parameters that were tested in the field were pH, electrical conductivity, and temperature. Furthermore, once a season, water samples were collected from each sampling point in order to determine the concentration of dissolved ions. All results were analyzed against the results of the reference zone and furthermore, against the South African Water Quality Guidelines for livestock farming and domestic use. The conclusion drawn from these results is that this catchment area is altered by mine drainage from the defunct colliery. However, it seems that mitigation measures designed by previous miners are effectively treating the AMD generated which has resulted in the neutralization of this acidity such that any decant from old mine works into the Wasbank River is slightly alkaline. Furthermore, based on SAWQG, the study concluded that this catchment is within the water quality standards for livestock farming and domestic use. However, there are minor restrictions to certain specific uses because of its salty state. Subsequent to the findings of this study, the defunct colliery can be considered as low priority of future rehabilitation efforts due to the state of water quality of the surrounding drainageItem Water management in the South African mining sector: the role of climate stress(2017) Lugalya, Marie MinayoWater including both abundance and scarcity are critical issues worldwide. Concerns are escalating across the globe as many nations are struggling to secure sufficient water (CDP, 2013). Water shortages and periods of abundance could be triggered by several factors either due to physical conditions (rainfall patterns, evaporation, and temperature) or management capacities (policies, regulation, maintenance and monitoring) (Faramarzi et al., 2013). Furthermore the rate at which environmental, social, economic and political systems are continuously shifting has further complicated this issue. Factors, such as overpopulation, inadequate governance, rapid industrial development, intensive agricultural farming and extreme weather conditions all have the potential to adversely influence existing water scarcity (Faramarzi et al., 2013). Similar to many developing countries, South Africa faces the predicament of sustaining growing populations and industrial developments whilst preserving the ecosystem (DEA, 2013). The country is particularly vulnerable to periods of excess and water scarcity due to its distinctive climatic conditions. South Africa is characterised by exceedingly variable to low rainfall patterns, decreased humidity and high air temperatures (Ziervogel et al., 2014). The combination of these climatic conditions causes high levels of evaporation resulting in reduced water availability (Ziervogel et al., 2014). Climate alone does not influence water supply, as water conditions are impeded by various socioeconomic challenges. The severity of water scarcity, for example, is further compounded by rising water demands and declining water quality within the country (DEA, 2013). Water is essential for several processes across various industries (including health care, pharmaceuticals, energy, retail, construction agriculture, manufacturing, food and beverages) all of which contribute towards a thriving economy (DEA, 2013). Therefore the impacts of water scarcity and abundance (for example, extreme flooding) could likely threaten all water-dependent industries, the consequence of which would be devastating throughout the country. [No abstract provided. Information taken from introduction]Item Hydrogeological characteristics of Hartbeespoort Dam(2017) Davis, AqueelahHartbeespoort Dam, the source of irrigation and potable water for the local community of Hartbeespoort area is a vulnerable water resource. The aim of this research was to evaluate the interaction between dam water and groundwater as well as characterise the hydrochemical data from metals and tritium. The former was done through the application of environmental isotopes and the implementation of a long term water balance, while the latter used hydrochemical data to define the spatial distribution of metals and tritium. The results indicated that the dam water is separated from the groundwater in winter. Two sources of mixing were recognized to have occurred downstream of the dam in 2015 but not in the Hartbeespoort dam area. These were identified as artificial through the runoff of agricultural water that was abstracted from the dam and through the pumping of water near the fault. Higher than normal tritium concentration indicated that contamination comes through the Crocodile River after the fault connecting the river to Pelindaba, the nuclear power generation plant south of Hartbeespoort Dam in the Broederstroom area. The Crocodile River showed that the contamination of water by lead, 22.11ppb in summer and 3.8 ppb in winter, and cadmium,2.2 ppb in winter. The Magalies River feeds the dam with copper. All metals accumulate at the dam wall and settles in the sediment, diluting the downstream water. Boreholes near the dam and spring along the fault are vulnerable to contamination. The water balance estimation resulted 18 345 472m3, with a 3.9% error, gain of water to the dam from the groundwater greater than the amount exiting the dam to through groundwater. The groundwater entering the dam is estimated to be 32 517 704m3. The groundwater exiting the dam is estimated at 14 172 232m3. The difference in groundwater showed a decrease of 10 000 000m3 over the 15 year period from 1st October 2000 until the 30th September 2015. Consequently, these results show an increased stress placed on the groundwater presumably due to an increase in groundwater abstraction from agriculture and the expanding mining area.