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dc.contributor.advisorVermeulen, P. D.
dc.contributor.authorBester, Michael
dc.date.accessioned2015-10-09T09:14:18Z
dc.date.available2015-10-09T09:14:18Z
dc.date.copyright2009-11-30
dc.date.issued2011-11-18
dc.date.submitted2009-11-19
dc.identifier.urihttp://hdl.handle.net/11660/1341
dc.description.abstractEnglish: The Waterberg coalfields represent the last area in South Africa, which contain large quantities of coal resources. According to Dreyer (pers. comm. 2009) the Waterberg coalfields contain nearly 50% of the remaining coal resources of South Africa. Given the great demand for coal both local and abroad, primarily to be used as a fuel source for the power generation, the Waterberg coalfields have been targeted for large scale developments in order to exploit the coal. The primary method for exploiting coal is through mining. Mining, in any setting and any location has a diverse and often very serious impact on the environment. A scoping level study was under taken in order to determine the effect the mines will have on the groundwater resources and the pre-mining conditions of the aquifers and the quality of the groundwater. At present there is one operational colliery in the study area, the Grootegeluk mine. This mine has been in operation since the 1980’s and has had a well-planned and operated monitoring system in place since the beginning of mining operations. This mine was used as a model to determine the impact new mines will have on the area. From the investigations it became apparent that the coalfield is situated in the Karoo Supergroup geology with the Mokolian Supergroup being represented in the study area by the Waterberg group quartzites. The coalfield is delineated by three major geological structures, the Daarby-, Eezaamheid- and the Zoetfontein faults. With the Daarby- and Eenzaamheid faults being impermeable according to Dreyer (pers. comm. 2009), The Daarby fault serves to divide the study area into an area west of the fault with shallow coal and an area east of the fault with deeper coal. Only the shallow coal will be mined. According to Dreyer (pers. comm. 2009), all of the planned infrastructure for the new mines will be located on the Waterberg group rocks south of the Eenzaamheid fault or on the Karoo rocks east of the Daarby fault. To determine the impact the mines would have on the groundwater of the study area, aquifer parameter testing (pumping test and slug tests), water quality determinations (inductively coupled spectrometry), acid-base accounting and numerical modelling were conducted. The results of the aquifer testing indicated low yielding aquifers with the harmonic mean of the transmissivities indicating a low transmissivity of 0.4 m2/d. In addition the recharge for the study area was calculated by means of the Cl and E.A.R.T.H. methods, resulting a value of 1.5% for the area. The average water level for the area was found to be approximately 28 m. The water quality determinations for areas that had not been affected by mining, indicated waters that had high EC values, near neutral pH value and medium to high Cl and sulphate values. The areas that have been affected by activities such as power generation and mining, displayed higher EC, Cl, and sulphate values than the unaffected areas. To more accurately determine the impact the mines would have on the area, numerical modelling was done. Three scenarios were simulated using similar parameters to determine the expected inflow into the mines and whether the mines would ever decant. The results indicated that the worst possible scenario there was an influx varying between 755 m3/d and 1283 m3/d depending on the location of the pits. For the decant models, 50 years after mining had stopped there was a rise of 3 m in the pits themselves. With the pits being simulated being 110 m deep it is concluded that the mines in the area will never decant. The results of the project indicate that the addition of new mines to the area will have an effect on the groundwater quality and quantity and steps should be taken to minimise this as much as possible.en_ZA
dc.description.abstractAfrikaans: Die Watergberg se steenkoolvelde verteenwoordig die laaste gebied in Suid Afrika wat oor groot steenkoolbronne beskik. Volgens Dreyer (pers. comm. 2009) bevat hierdie steenkoolvelde soveel as 50% van die oorblywende steenkool van Suid Afrika. As gevolg van die groot aanvraag na steenkool, hoofsaaklik as ‘n brandstof vir kragopwekking, word die area (Waterberg se steenkoolvelde) geteiken vir grootskaalse ontwikkeling, hoofsaaklik met die oog op die eksploitering van die steenkoolbronne. Die mees ekonomiese vorm van steenkool-eksploitering is deur middel van mynbou. Daar is verskillende vorms van mynbou wat toe-gepas word om steenkool te ontgin, elkeen van hierdie metodes het sy eie afsonderlike impak op die omgewing. ‘n Oorsigvlak assessering is geloods om vastestel wat die effek van die myne op die grondwater sal wees en ook wat die huidige staat van akwifere en die kwaliteit van die grondwater is. Huidiglik is een steenkoolmyn in werking in die studiegebied naamlik, Grootegeluk. Die myn is vanaf 1980 in werking en beskik oor ‘n goed beplande en goed instand gehoude moniteringstelsel vir grondwater in en om die myn. Die myn is as ‘n model gebruik om te bepaal wat die impak van die nuwe myne op die omgewing sal wees. Dit het vroeg in die verloop van die ondersoek bekend geword dat die Waterbergse steenkoolvelde in die Karoo Supergroep geleë is met ‘n bykomende Supergroep, die Mokolian Supergroep ook teenwoordig in die studiegebied. Die Mokolian Supergroep word in die studiearea verteenwoordig deur die Waterberggroep kwartsiete. Die steenkoolveld word begrens deur drie groot verskuiwings, naamlik die Daarby-, die Eenzaamheid- en die Zoetfonteiverskuiwings. Volgens Dreyer (pers. comm. 2009) is die Daarby- en Eenzaamheidsverskuiwings ondeurdringbaar en verdeel die Daarbyverskuiwing die studie- gebied in twee areas, naamlik ‘n area met vlak steenkool, wes van die verskuiwing en ‘n area met dieper steenkool, oos van die verskuiwing. Volgens Dreyer (pers. comm. 2009) sal al die beplande infrastruktuur vir die nuwe myne of op die Waterberggesteentes, suid van die Eenzaamheid verskuiwing, of op die Karoogesteentes, oos van die Daarbyverskuiwing, gebou word. Om vastestel wat die impak van die nuwe myne op die grondwater sal wees, is akwifeer- toetse (pomptoetse), watergehalte bepalings, suur-basis bepalings (op die gesteentes) asook numeriese modellering, gedoen. Die akwifeertoetse het aangedui dat die gesteentes ‘n lae lewering het met ‘n lae transmisifiteit van 0.4 m2/d. Bykomend tot die akwifeertoetse is aanvullingberekenings gedoen met behulp van twee metodes (Cl en E.A.R.T.H. metode) wat ‘n aanvulling van 1.5% aangedui het. Die gemiddelde watervlak in die area is 28 m. Die watergehalte bepalings vir areas wat nie deur aktiwiteite soos mynbiou beïnvloed is nie, het aangedui dat die water ‘n hoë EC het, byna neutraal pH met medium tot hoë hoeveelhede chloor en sulfaat. Die bepalings vir areas wat wel beïnvloed is deur aktiwiteite toon hoër EC, Cl en sulfaat waardes as die areas wat nie beïnvloed is nie. Om te bepaal wat die impak van die myne op die grondwater sal wees, is numeriese modellering gedoen. Drie moontlikhede is gemodelleer met soortgelyke parameters. Die doel was om te bepaal wat die invloei in die myne sal wees asook of die watervlakke in die myne ooit op die oppervlak sou uitloop. Die resultate het n invloei wat wissel tussen 755 m3/d en 1283 m3/d aangedui, afhangende van die ligging van die myn. Die opvullingsmodelle het aangedui dat die watervlakke in die myne nooit op die oppervlak sal uit loop nie. Met ‘n maksimum styging van 3 m in watervlak 50 jaar nadat mynbou gestaak is. Die bevindinge van die projek is dat die myne ‘n negatiewe impak op die grondwater hoeveelhede en gehalte sal hê. Dit word aanbeveel dat die mynmaatskappye stappe neem om die impak te verminder.af
dc.description.sponsorshipWater Research Commissionen_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectDissertation (M.Sc. (Institute for Groundwater Studies))--University of the Free State, 2009en_ZA
dc.subjectGroundwater -- Quality -- South Africaen_ZA
dc.subjectCoal mines and mining -- Environmental aspects -- South Africaen_ZA
dc.subjectCoalfields -- South Africaen_ZA
dc.titleGroundwater resource assessment of the Waterberg coal reservesen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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