- Title
- Hydrochemical assessment of mine water discharging into the surface and groundwater systems that flow through the Cradle of Humankind World Heritage Site, South Africa
- Creator
- Long, Chazanne Anita
- Subject
- Cradle of Humankind World Heritage Site (South Africa)
- Subject
- Environmental chemistry Mine water -- South Africa Acid mine drainage -- South Africa Geochemistry
- Date Issued
- 2018
- Date
- 2018
- Type
- Thesis
- Type
- Masters
- Type
- MSc
- Identifier
- http://hdl.handle.net/10948/30928
- Identifier
- vital:31225
- Description
- The UNESCO site known as the Cradle of Humankind World Heritage Site (COH WHS) is a globally important cultural heritage area that hosts some of the oldest discovered hominid fossils and is a major contributor to our understanding of the evolution of modern hominids over the past 3.5 million years. The area is locally referred to as the Cradle of Humankind that flanks a densely populated region in South Africa, and which hosts a large sector of the Witwatersrand Basin, known as the West Rand. The Witwatersrand Basin contains the world’s largest gold deposits, some of which have been mined for more than 130 years. This study characterises the West Rand mine drainage to determine the extent of the hydrochemical interaction within the COH WHS and beyond. The hydrochemistry of surface waters was analysed across a sub-catchment draining the West Rand, using standard q-ICPMS and IC techniques. A total of 32 samples were collected quarterly for an annual cycle during 2011 to 2012. The median data were used for standard hydrochemical classifications for surface waters and two mine water classification systems. This is the first time this type of quantitative and comparative study has been performed in South Africa. The results of these classifications show that the mine drainage generated from the West Rand Goldfield can be described as an acidic (pH = 3.19 to 3.36), highly metalliferous (ΣMetals = 2564 to 3 141 μg/L) mine drainage, and with (SO42- = 3217 to 3532 mg/L) and (TDScalc = 3217 to 3536 mg/L). This mine drainage has been allowed to discharge continuously into the environment for fifteen years following the flooding of the mine voids in 2002. The extent of the mine drainage signature was determined to flow through the southern portion of the COH WHS and into the Crocodile River up to 54.2 km (CA24) downstream of the point source from Randfontein Estates mine property in the West Goldfield. In addition to the surficial contamination, there is evidence of groundwater – surface water interactions within the karstic terrain of the COH WHS. The findings highlight the need for on-going monitoring and further research to determine the possible consequences that acidic mine drainage discharge has on the environment and on the yet undiscovered fossils within the cave systems of the COH WHS. The GARD and Ficklin mine water classifications are used and compared in this thesis. A single universal hydrochemical classification system, capable of becoming a globally robust and standardised approach for mine waters is a valuable contribution that is needed within this field of study, along with the inclusion of uncertainty presented graphically in a clear and unambiguous way. Research is needed to provide realistic solutions that can be implemented to mitigate potential negative outcomes identified and that are in-line with national and global legislation to preserve and protect this world heritage area. The study has implications for mine water legislation and monitoring in areas of active and historic mining, and for water resource management.
- Format
- xxii, 157 leaves
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Chazanne Anita Long.pdf | 41 MB | Adobe Acrobat PDF | View Details Download |