An investigation into the quality of surface water and ground water was conducted during 1988 in the 38,8 km² Hout Bay River catchment near Cape Town. The main objective of the study was to determine those areas and activities which constitute a pollution source and to ascertain the relative proportion which each contributes to the pollution problem and health risk of the surf zone of the beach at Hout Ba . The objective was achieved by monitoring the chemical and microbiological attributes of the Hout Bay River, its tributaries and stormdrains in wet and dry conditions on a routine basis and during storm events. Hout Bay is a rapidly developing residential area in which sewage disposal occurs by means of septic tank soakaway systems. Ground water quality was monitored to investigate the contribution to contamination by septic tank effluent. Results showed that stormdrain effluent in dry and wet conditions and surface runoff during rainfall were the main vectors of pollution. Although the pollution concentration was high during dry conditions the greatest pollution discharge to the surf zone of Hout Bay occurred during storm events. In view of the proposed residential development it is imperative that pollution control measures be undertaken so as to secure the future recreational and aesthetic value of Hout Bay

MESC / Department of Hydrology and Water Resources / Wetlands are known of their pollution reduction characteristics due to their flat topography and dense vegetation which capture pollutants on the settling sediments. Three processes take place on the captured pollutants in the sediments, the physical, chemical and biological processes, which facilitate the removal of pollutants from the wetlands. This research was carried out in order to assess the Water Quality of wetland downstream of Makhado oxidation ponds and its potential effects on Irrigation Waters by determining the Physical-chemical parameters (pH, Dissolved Oxygen, temperature, electrical conductivity and turbidity); the nutrient levels (Nitrates, phosphates, nitrites, bromide) and heavy metals. The water samples were collected from the effluent discharge of Makhado oxidation ponds (upstream), the middle section of the wetland (midstream) and downstream of the wetland. The climate data for the study was also used assess the contribution to variation in the physical-chemical parameters during their passage through the wetland. The use of waters in the wetland by subsistence farmer’s was also assessed to determine their farmer’s perception on wastewater reuse, sustainability, water quality, health hazards and crop yield. At the discharge and midstream point, the physical parameters tested were found to be mostly outside the target water quality range of irrigation water set out by DWAF but are within the DWAF guidelines for discharge of wastewater. The exceptions were with total dissolved solids which were higher than 25 mg/l guideline value of the said standards. The anions were analysed by Ion chromatography and showed spatial variation in content and seasonality. The nutrients (nitrates, nitrites and phosphates) and chloride were higher than the DWAF guidelines for discharge of wastewater. The heavy metal content in the wetland was analysed by ICP-OES and varied throughout the wetland. The following metals were reduced during their passage in wetland and were within DWAF guidelines: zinc, lead, cadmium and total chromium. Iron and manganese were reduced during the drier season but were above the DWAF guideline values during the wet season. Also the metal contents in the wetland are out of the target water quality range of the same standards bringing forth the risks of toxicity in the wetland. The anion analysis also suggests that the wetland is becoming a nutrient rich environment bringing forth risks of eutrophication. Nitrite concentrations did not conform to the South African viii Water Guidelines on target water quality ranges for irrigation water. Farmers have expressed a positive opinion on wastewater use for irrigation since there are loads of nutrients. The presence of nutrients in wetland may contribute to development of harmful algal blooms.

MSc (Microbiology) / Department of Microbiology / See the attached abstract below

MSc (Microbiology) / See the attached abstract below

Freshwater resources and supplies in South Africa are experiencing severe stress from rising population growth, drought and high urbanization. The stress factors have also exerted pressure on wastewater treatment works leading to the release of partially treated effluent. The study assessed and compared the impact of the two wastewater treatment works effluent discharged into the Roodeplaat Dam. Selected physical parameters (pH, conductivity), chemical parameters (total oxidised nitrogen, phosphate, chemical oxygen demand, chloride, sulphate, sodium) and microbiological parameter (Escherichia coli) were evaluated and compared with South African standards. Secondary data (from January 2012 to December 2017) was used to identify parameters that were above or below regulatory standards. The t-test (p < 0.05) was used to compare changes between 2012 and 2018 over the same months.The results indicated that aquatic ecosystem quality has not improved, degradation continues as well as a lack of intervention from authorities. The leading parameters in causing stress to Roodeplaat water quality in descending order were Escherichia coli (E. coli), Phosphate (PO43-), Total Oxidized Nitrogen (TON), Chemical Oxygen Demand (COD), Chlorophyll a (Chl a), Ammonia (NH3), Electrical Conductivity (EC) and Sodium (Na). One of the main reasons why poor effluent was released is limited financial investment to upgrade the treatment facilities. This research provided highlights on the need to enforce extra measures to guarantee compliance of treated effluent quality to the existing guidelines. Moreover it highlights the need for concerned department’s authorities to invest in water by allocating enough budget to address the challenge of wastewater treatment works upgrades. / Environmental Sciences / M. Sc. (Environmental Sciences)

Thesis (M.Sc.(Chemistry)) -- University of Limpopo, 2022 / Water contamination caused by toxic elements has serious human health and ecological implications. The increasing quantity of toxic elements in surface and groundwater is currently an area of greater concern, especially since many industries are discharging their metal containing effluents into freshwater without any adequate treatment. The mineral dissolution in mining regions is highly enhanced by mining and smelting activities. The mine waste and drainage in areas surrounding mines have high levels of toxic element contamination above the permissible limits. Contamination of groundwater by toxic elements such as As, Fe, Mn, Al, Cr, Zn and Co due to operational activities of surrounding mines in the Sekhukhune district was reported by several researchers. Removal of toxic elements from contaminated water is a big challenge. The affected communities need to attain a safe water supply source for daily usage, hence there is an urgent need of technologies for the treatment of water supplies contaminated with these toxic elements to ensure the safety of potable water. The study was undertaken by modifying nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) and investigating the removal of chromium, nickel and lead from anthropogenic contaminated groundwater in the Sekhukhune area, in Limpopo. The as-prepared N-MWCNTs functionalised with metal oxide, thiol and amino functional groups are expected to increase the surface area of the nanocomposite, which can facilitate high adsorption of contaminants from water samples. The adsorption capabilities for the removal of these toxic elements by modified N MWCNTs nanocomposites were investigated in batch studies as a function of different parameters. The parameters studied included pH, contact time, adsorbent dosage, initial concentration, temperature, competing ions and reusability. The optimum condition was then acquired for removal of selected toxic elements from real water studies. The removal efficiencies of the as-prepared nanocomposites were pH dependent and the optimal pH values for adsorption was 5.5, 1.5, 11 and 6 at optimum contact time of 10, 80, 60 and 120 min and dosage of 0.30, 0.35, 0.05 and 0.6 g/L for Cr(III), Cr(VI), Ni(II) and Pb(II), respectively. The prepared nanocomposites were characterised using various techniques such as Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmet-Teller (BET) and thermogravimetric analysis (TGA). The FTIR analysis confirmed the presence of Fe3O4, -SH and -NH2 groups on the functionalised MWCNTs. The PXRD analysis further supported that the synthesized nanocomposites consisted of hexagonal graphite structure of MWCNTs. Furthermore, SEM and TEM results showed that the introduced functional groups were uniformly attached on the surface of the MWCNTs. The BET analysis indicated that the surface area of the modified MWCNTs nanocomposites increased significantly as compared to the acid treated MWCNTs. In addition, TGA showed that the M-MWCNTs (M = modified) nanocomposites possess high thermal stability. Raw N-MWCNTs showed higher stability as compared to oxidised N-MWCNTs, which decomposes at lower temperatures of 200 °C. No weight loss was observed below 800 °C for the hydrazine functionalised nanocomposites as compared to the triethylenetetramine (TETA)- substituted nanocomposites, which showed weight loss at 300 °C. Toxic elements in solutions before and after treatment were quantified using flame atomic absorption spectrometry (F-AAS). The adsorption isotherms of the as-prepared nanocomposites for chromium, nickel and lead removal fitted both the Langmuir and Freundlich model depending on the adsorbent used, which suggest that the adsorption process met both monolayer and heterogeneous adsorption. Thermodynamic analysis showed that the adsorption of Cr(III), Cr(VI), Ni(II) and Pb(II) ions are spontaneous and endothermic. The as-prepared nanocomposites showed an outstanding regeneration performance retaining over 50% toxic elements removal. Thus, the as prepared nanocomposites are promising for practical application in toxic element treatment. Analysis of the collected river and borehole water in Sekhukhune indicated that the concentration of total chromium, nickel and lead before treatment varied from (0.207 to 0.286 mg/L), (0.226 to 0.380 mg/L) and (3.301 to 8.017 mg/L), respectively which were above acceptable levels recommended by the South African National Standards (SANS), United States Environmental Protection Agency (USEPA) and World Health Organisation (WHO), i.e., 0.05 mg/L, 0.07 mg/L and 0.01 mg/L. After treatment, the nanocomposites were able to remove 100% of the metal ions from the water. TETA-functionalised nanocomposites showed greater removal efficiencies in comparison to the hydrazine-functionalised nanocomposites for all the studies done. / Water Research Commission (WRC)

Thesis (MSc)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Water quality analysis forms the basis in assessing and monitoring catchments. As urban development continuously increase, pollution sources increase in either point source (wastewater treatment works, industrial effluents) and/or non-point source origin (storm water discharge, domestic pollutants), accumulating pollutants in the environment. It was only recently discovered that certain pollutants have subtle disrupting effects on the endocrine system resulting in health related problems associated with the reproductive system and thyroid system (growth and development) of animals and potentially humans. Natural water resource management proves to include limited biological assays measuring endpoints for cytoxicity, inflammatory activity and endocrine disruption. The broad objective of this study was therefore to include several bioassays, not normally used in municipal (City of Cape Town) monitoring programmes, along with water quality data collected by the City of Cape Town. The Eerste/Kuils River catchment system, Western Cape, under the auspices of the City of Cape Town was chosen, and although this catchment does not contribute to drinking water resources, is subjected to a range of anthropogenic influences (industrial effluents, household wastewater, agricultural runoff). Within the short time-frame available for this study (six months) two months, July (following a dry summer and autumn season) and October (following a wet winter and early spring season) were selected for water quality monitoring. Spatial variation (with relevance to specific point and non-point contamination) among sampling sites were also obtained by choosing several (n=10) along the catchment. Specific aim of the study therefore included: Firstly (Chapter 2), the use of in vitro bioassays, lactate-dehydrolises assay (LDH) for cytotoxic activity, pro-inflammatory hormone Interleukin-6 (IL-6) secretion by human blood cells and a specific Salmonella ELISA for faecal contamination, in conjunction with routine chemical and biological (mostly microbiological) monitoring activities. The study indicated significant variation among sites in all microbiological measures as well in IL-6 secretion and Salmonella presence. Between months, variations were also evident in certain variables. Secondly (Chapter 3), two bioassays using the yolk precursor protein, vitellogenin (Vtg) as endpoint was implemented in a) an in vitro Xenopus laevis liver slice assay (five day exposure) and b) an in vivo Zebrafish (Danio rerio) bioassay (seven day exposure) assessing estrogenic activity in the Eerste/Kuils River catchment. Although estrogen spiked positive control water samples stimulated Vtg production in vitro as well as in vivo, no dramatic estrogenic activity was measured at any of the selected sites. Thirdly (Chapter 4), a bioassay using the thyroid controlled metamorphosis in Xenopus laevis tadpoles to assess effects on the thyroid hormonal system was implemented. Thyroid stimulatory activity, compared with a negative control sample, was measured at two sites along the catchment. Although the practical implementation of the tadpole semi-static exposure protocol (water replacement) proved to be labour intensive, all the added bioassays proved to be valuable tools to add valuable information regarding water quality. It is clear that more research related to anthropogenic influences along the Eerste/Kuils River catchment system are needed, specifically in monitoring monthly variations to better understand annual variation in several of the endpoints studied. / AFRIKAANSE OPSOMMING: Waterkwaliteit vorm die basis vir die evaluering en monitering van opvangsgebiede. Voortdurende stedelike ontwikkeling gee aanleiding tot ‘n toename in die voorkoms van besoedelstowwe in die natuurlike omgewing deur gelokaliseerde (punt) bronne (rioolwerke/industriële uitvloeisel) en/of nie gelokaliseerde (nie punt) bronne (vloed uitlaat/huishoudelike uitvloeisels) van besoedeling. Dit het onlangs aan die lig gekom dat van hierdie chemise besoedelstowwe subtiel die endokriene sisteem versteur en so aanleiding gee tot gesondheidsprobleme in terme van die voortplantingsisteem en tiroied sisteem (groei en ontwikkeling) by diere en moontlik ook die mens. Daar is beperkte gebruik van biologiese toetse wat inligting verskaf oor sitotoksiteit, inflammatoriese aktiwiteit en endokriene versteuring. Die doel van hierdie studie was dus om van hierdie biologiese toetse, wat normaalweg nie deel uitmaak van die roetine munisipale (Stad van Kaapstad) opvangsgebied monitering nie, gebruik te maak. Die Eerste-, Kuilsrivier, Wes Kaap, onder beheer van Stad Kaapstad is gekies en alhoewel die opvangsgebied nie water bydra tot drinkwaterbronne nie, word die opvangsgebied beïnvloed deur verskeie mensgemaakte bronne van besoedeling (afloop vanuit omliggende lanbougebiede). Binne die kort tydsraamwerk van die projek (ses maande) is besluit om twee maande, Julie (volg ‘n droë somer en herfs seisoen) en Oktober (volg ‘n nat winter en vroeë lente seisoen) vir water kwaliteit monitering te kies. Ruimtelike variasie langs die loop van die opvangsgebied is ingesluit deur moniteringspunte (n=10), met in ag name van die potensiële besoedelingsbronne. Spesifieke doelwitte van die projek sluit in: Eerstens (Hoofstuk 2), om die in vitro biotoetse, laktaat hidrolise (LDH) vir sitotoksisiteit, proinflammatoriese hormoon Interleuikin-6 (IL-6) vir inflammatoriese aktiwiteit, vrygestel deur menslike bloedselle en ‘n Salmonella ELISA vir ontlasting besoedeling saam met bestaande chemise en biologiese (hoofsaaklik migrobiologiese) veranderlikes te gebruik. Die studie het getoon dat beduidende variasie in alle mikrobiologiese toetse asook IL-6 vrystelling en Salmonella voorkoms bestaan het tussen versamelpunte. Maandelikse variasie in sekere van die veranderlikes het ook voorgekom. Tweedens (Hoofstuk 3), is twee biotoetse wat die dooiervoorloperproteïen, vitellogeen (Vtg) as eindpunt gebruik geimplimenteer in a) ‘n in vitro Xenopus laevis lewersnit biotoets (vyf dag blootstelling) en b) ‘n in vivo Zebravis (Danio rerio) biotoets (sewe dag blootstelling) om estrogenisiteit in die Eerste-, Kuilsrivier opvangsgebied te evalueer. Alhoewel, die estrogeen behandelde positiewe kontrole water monsters Vtg produksie veroorsaak het in beide die in vitro lewer-kulture en in vivo vistoets, is geen dramatiess estrogeniese aktiwiteit by enige van die moniteringspunte gevind nie. Derdens (Hoofstuk 4), is ‘n biotoets wat die tiroïedbeheerde metamorfose in Xenopus laevis paddavisse gebruik om effekte op die tiroïedsisteem te evalueer. Die differensiële stimulering (versnelling), in vergelyking met ‘n negatiewe kontrole watermonster, van die tiroied sisteem is by twee moniteringspunte in die opvangsgebied waargeneem. Alhoewel die praktiese implementering van die paddavis semi-statiese (water word gereeld vervang) biotoets arbeidsintensief is, het alle bykomstige biotoetse waardevolle bykomstige inligting oor water kwaliteit verskaf wat ‘n belangrike bydrae tot ingeligte bestuursbesluite kan verleen. Dit is duidelik dat meer navorsing int verband met die menslike invloed langs die Eerste-, Kuilsrivier opvangsgebied nodig is, veral met maandlikse monitering vir seisoenale veranderinge.

Thesis (MSc)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: The River Health Programme (RHP) is an assessment tool for monitoring the ecological state of rivers to ensure that they remain fit for use by present and future generations. This study, forming part of a RHP assessment conducted on the south-western Cape Hout Bay, Lourens and Palmiet Rivers, has the aim to (1) zone the rivers for representative site selection, (2) assess their habitat integrity (HI), (3) determine the influence of land use on riverine HI and (4) assess the river water quality at the time of the RHP assessments. (1) The desktop geomorphological zonation method used in RHP assessments has not been sufficiently previously tested on short rivers draining the Western Cape Mountains. The Lowland River Zone of the rivers studied, as well as the Hout Bay River’s Upper Foothill Zone, were found to have steeper gradients than expected, probably due to these rivers being shorter and consequently steeper than any on which the method was previously tested. The notion of one gradient river classification system being applicable throughout South Africa, with its diverse geology and climate, is unlikely. Rather a classification system modified for various physiographic features regions or by a factor based on river length is more realistic. (2) Although there is a general longitudinal decrease in HI downstream along the Hout Bay and Lourens Rivers, coinciding with increased anthropogenic activities, HI improves in the Palmiet River’s lower reaches through the Kogelberg Nature Reserve. Surrounding land use thus seems to be a major determinant of HI. Although the Index of Habitat Integrity (IHI) used appears to achieve its aim, it was found to be subjective. Categorisation of the IHI scoring is suggested. (3) The amount of natural versus disturbed land use occurring upstream of a site at a regional and local scale, is a good predictor of riverine HI. Regional alien forestry and local urbanisation have significantly strong negative effects on instream (r2 = -0.80, r2 = 0.80, p<0.05) and riparian (r2 = -0.81, r2 = -0.83, p<0.05) HI. Different land use types therefore appear to affect riverine HI at differing scales and thus managers must not only think on a local but also a catchment scale. (4) In the Hout Bay River, a filtering system (e.g. wetland) appears to improve the water quality between the middle and lower reaches. Along the Lourens River, high total dissolved salts, conductivity and inorganic nitrogen concentrations in the middle reaches are cause for concern. Along the Palmiet River there appeared to be insufficient oxygen to support most aquatic life forms at Grabouw. Impoundments in the middle reaches act as sinks for nutrients and salts, but the Huis and Krom tributaries downstream then appear to degrade the water quality of the Palmiet River’s lower reaches within the Kogelberg Nature Reserve. Together with the results of simultaneous biotic assessments, these results should be used to develop management actions to improve the ecological health of these rivers. The results have been used in a State-of-Rivers Report for the south-western Cape. / AFRIKAANSE OPSOMMING: Die Riviergesondheidsprogram (RGP) is 'n asseseringsinstrument wat die ekologiese stand van riviere monitor om te verseker dat hulle steeds bruikbaar bly vir huidige en toekomstige geslagte. Hierdie studie maak deel uit van 'n RGP-assessering van die Lourens-, Houtbaai- en Palmietrivier in die Suidwes-Kaap en het ten doel om (1) die riviere te soneer vir verteenwoordigende terreinseleksie, (2) die habitat-integriteit (HI) te assesseer, (3) die invloed van grondgebruik op rivier-HI te bepaal en (4) die kwaliteit van rivierwater tydens die RGP-assesserings te bepaal. (1) Die geomorfologiese-soneringsmetode wat in RGP-assesserings gebruik word, is nog nie voorheen genoegsaam vir die kort riviere wat die Wes-Kaapse berge dreineer, getoets nie. Daar is bevind dat die studiegebied riviere in die laagland-sones skerper gradiënte het as verwag, gehad het. Dit kan moontlik toegeskryf word aan die riviere wat korter en dus steiler is as enige van dié wat voorheen met die metode getoets is. Die moontlikheid dat een gradiëntklassifikasiestelsel vir riviere regdeur Suid-Afrika met sy diverse geologie en klimaat toegepas kan word, is onwaarskynlik. 'n Klassifikasiestelsel aangepas vir verskillende fisiografiese streke of met 'n faktor gebaseer op rivierlengte, is meer realisties. (2) Alhoewel HI stroomaf langs die Lourens- en Houtbaairivier in die algemeen longitudinaal saam met die toename in antropogeniese aktiwiteite afneem, verbeter die Palmietrivier se HI waar dit laer af deur die Kogelbergnatuurreservaat vloei. Die gebruike van aanliggende grond blyk dus 'n belangrike bepaler van HI te wees. Die Indeks van Habitatintegriteit (IHI) bereik klaarblyklik die vereiste doel, maar is te subjektief. Kategorisering van die IHI-waardes word voorgestel. (3) 'n Goeie voorspeller van rivier-HI is die hoeveelheid natuurlike teenoor versteurde grondgebruik stroomop van 'n terrein op 'n streeks- en lokale skaal. Die sterk negatiewe effek van uitheemse plantegroei in die omgewing en lokale verstedeliking op stroom- (r² = -0.80, r² = 0.80, p<0.05 ) en oewer-HI (r² = -0.81, r² = -0.83, p<0.05) is beduidend. Verskille in tipe grondgebruik beïnvloed rivier-HI op verskillende vlakke; bestuurders moet dus plaaslik en aan die opvanggebied dink. (4) In die Houtbaairivier lyk dit asof 'n filtreringstelsel (bv. vleigrond) die waterkwaliteit tussen die middel- en lae gedeeltes verbeter. In die loop van die Lourensrivier is hoë totale opgeloste soute, geleidingsvermoë en anorganiese stikstofkonsentrasies in die middelgedeelte 'n rede tot kommer. In die Palmietrivier by Grabouw was die suurstof te min om die meeste akwatiese lewensvorme te onderhou. Opgedamde water in die middel gedeeltes dien as 'n sink vir voedingstowwe en soute, maar dit lyk asof die Huis- en Kromrivier die waterkwaliteit van die Palmietrivier stroomaf in die Kogelbergnatuurreservaat degradeer. Saam met die resultate van gelyktydige biotiese assesserings, kan hierdie resultate gebruik word vir die ontwikkeling van bestuursaksies om die ekologiese toestand van hierdie riviere te verbeter. Die resultate is gebruik in 'n toestand-van-riviere-verslag vir die Suidwes-Kaap.

Industrial effluents with high concentrations of heavy metals are widespread pollutants of great concerns as they are known to be persistent and non-degradable. Continuous monitoring and treatment of the effluents become pertinent because of their impacts on wastewater treatment plants. The aim of this study is to determine the correlation between heavy metal pollution in water and the location of industries in order to ascertain the effectiveness of the municipal waste water treatment plant. Heavy metal identification and physico-chemical analysis were done using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and multi-parameter probe respectively. Correlation coefficients of the measured values were done to investigate the effect of the industrial effluents on the treatment plants. Heavy metal resistant bacteria were identified and characterised by polymerase chain reaction and sequencing. Leeuwkuil wastewater treatment plants were effective in maintaining temperature, pH, and chemical oxygen demand within South Africa green drop and SAGG Standards whereas the purification plant was effective in maintaining the values of Cu, Zn, Al, temperature, BOD, COD, and TDS within the SANS and WHO standard for potable water. This findings indicated the need for the treatment plants to be reviewed.The industrial wastewater were identified as a point source of heavy metal pollution that influenced Leeuwkuil wastewater treatment plants and the purification plants in Vaal, Vereenining South Africa. Pseudomonas aeruginosa, Serratia marcescens, Bacillus sp. strain and Bacillus toyonensis that showed 100% similarity were found to be resistant to Al, Cu, Pb and Zn. These identified bacteria can be considered for further study in bioremediation. / Environmental Sciences / M. Sc. (Environmental Science)

Water quality deterioration is reaching crisis proportions in South Africa. Many South African catchments are over-allocated, and decreasing volumes of source water mean increasing concentrations of pollutants. The Crocodile River Catchment in the Mpumalanga province in South Africa was identified through previous research, as a catchment faced with deteriorating source water quality for water users in the catchment. Poor source water quality has become a sufficiently acute concern for the stakeholders in this catchment to co-operate in developing a process that assists with compliance control of their water use and waste disposal to reduce costs, decrease industrial risks as water quality compliance increases, and improve source water quality. The sugar industry is downstream within the Crocodile River Catchment, and is affected by the activities of all upstream water users; the industry is thus dependent on the stakeholders upstream participating in the effective management of the resource. However, the sugar industry is also located just before the confluence of the Crocodile River and Komati River upstream of the Mozambique border, and thus the water quality of the sugar industry effluent will affect the quality of the water that flows into Mozambique. The sugar industry is on the opposite river bank to the Kruger National Park, which has high water resource protection goals. Therefore, the sugar industry has a national role to play in the management of water resources in the Crocodile River Catchment. This study provides a focused view of the role of the sugar industry in the development of a co-operative, integrated water quality management process (IWQMP) in the Crocodile River Catchment. In order to address the objectives of this study, this research drew from an understanding of the social processes that influence water management practices within the sugar industry as well as social processes that influence the role of the Inkomati-Usuthu Catchment Management Agency as the main governing institution in water resource management in the Inkomati Water Management Area. The study also drew from an understanding of scientific knowledge in terms of a water chemistry which describes the upstream and downstream water quality impacts related to the sugar industry. The water quality analysis for the Lower Crocodile River Catchment shows a decline in water quality in terms of Total Dissolved Solids (TDS) loads when moving from below Mbombela to the Mozambique border. The major sources of TDS in the Lower Crocodile River are point source dominated, which may be attributed to the extensive mining, industrial and municipal activities that occur across the catchment. When observing Total Alkalinity (TAL) and pH values from below Mbombela to the furthest monitoring point, there is deterioration in the quality of the water in the Lower Crocodile River, with the Kaap River contributing a negative effect that is diluted by the Crocodile main stem. The Hectorspruit Waste Water Treatment Works (WWTWs) (located in the Lower Crocodile River Catchment) contributes high concentrations of TDS and TAL into the Crocodile River. Total Inorganic Nitrogen and Soluble Reactive Phosphorus concentrations decrease in the lower reaches of the Crocodile River compared with the river below Mbombela, which can be attributed to the extensive sugar cane plantations located in the Lower Crocodile River Catchment acting as an “agricultural wetland” that serves a function of bioremediation resulting in large scale absorption of nutrients. This is an interesting result as earlier assumptions were that fertiliser application would result in an overall increase in nutrient loads and concentrations. Biomonitoring data show no substantial change in aquatic health in the LowerCrocodile River Catchment. For a catchment that has an extensive agricultural land use in terms of sugarcane and citrus production, the Crocodile River is unexpectedly not in a toxic state in terms of aquatic health. This is a positive result and it suggests that pesticide use is strictly controlled in the sugar and citrus industry in the Crocodile River Catchment. For long term sustainability, it is essential for the sugar industry to maintain (and possibly improve) this pesticide management. The social component of this study aimed to provide an analysis of the management practices of the sugar mill as well as examining agricultural practices in the sugar cane fields in relation to water quality management through the use of Cultural Historical Activity System Theory (CHAT). This component showed that there are contradictions within the sugar industry activity system that are considered to be areas of “tension” that can be loosened or focused on to improve the contribution the sugar industry can make to the IWQMP. Surfacing contradictions within the sugar industry activity system and the Inkomati-Usuthu Catchment Management Agency activity systems highlighted areas of potential for learning and change. While an understanding of biophysical processes through scientific knowledge is critical in water management decision making, it is evident that an understanding of other actors, institutions and networks that inform water quality management decision-making also plays a significant role. The notion of improving the role of scientific or biophysical knowledge in contributing to socio-ecologically robust knowledge co-creation, decisions and actions towards resolving water quality problems is emphasised. Specifically, moving towards improving interactions between scientists and other actors (water users in the Crocodile Catchment in this case), so that scientific practices become more orientated towards societal platforms where water quality management is tackled to enable improved water quality management practices. Therefore, linking the social and biophysical components in this study provides a holistic understanding of how the sugar industry can contribute to the development of an IWQMP for the Crocodile River catchment.