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This article explores the possibilities of a cheap one-dollar microscope, the Foldscope, for enhancing out-of-school science education. Developed by Manu Prakash and Jim Cybulski from Stanford University, these origami-type paper microscopes make it possible to provide all students with their own microscopes, due to the low cost. This provides students the opportunity to engage in science outside of the classroom, as amateur sleuths engaged in environmental inquiries, e.g., determining the levels of pollution of local water resources. In this article the authors share two sets of research data: an activity where school students engaged in authentic problem-based learning using the Foldscopes, as well as student teachers' experiences of engaging with Foldscope microscopes. The outcomes of the first research project indicate that affective outcomes and cognitive gains were achieved. Responses in the second research project included five categories: preparation and presentation; potential of the Foldscope; use of slideshow; energy/complements; and limitations. The conclusion reached was that Foldscopes hold possibilities for enhancing STS (science-technology-society) approaches inside and outside the classroom. One recommendation is that such frugal-science approaches are emphasized more in both pre-and in-service teacher education.

The international Eco-Schools programme promotes Education for Sustainable Development (ESD) through introducing and stimulating pro-environmental initiatives by school learners and staff. This enabled learners in the Eco-Clubs at a resource-poor primary school to identify and undertake transformative pro-environmental initiatives in 2011 and 2014 through Self-Directed Education (SDE). An educative approach encouraging critical thinking at the school provided the foundation that made this possible. In discussing and working through their strategies to undertake research and challenge authorities about noncompliance in regard to municipal responsibilities that led to environmental degradation, Eco-Club members liaised freely with teachers and other learners. This process, together with local support for the eco-school initiatives, stimulated widespread interest and generated hope among learners by showing that another way of being is possible.

Manu Prakash, the developer of the foldscope microscope reported on in this paper, stated that it is important to use tools that can support open-ended inquiry in the classroom, without dumbing down those tools. Scientific equipment in the school laboratory is often very expensive and only available to those who can afford it. "Frugal science" is a trend in education that researches, develops and introduces economical and quality scientific resources to developing countries. In South Africa, many underprivileged schools lack quality practical and laboratory resources to perform simple tasks, such as microscopy. Furthermore, the absence of laboratory investigations could lead to learners not enjoying Life Sciences nor developing a more nuanced understanding of the nature (tenets) of science. As part of an indigenous knowledge intervention hosted by the North-West University, teachers were provided with $1 foldscopes (paper microscope) to use in their classrooms. This research reports on the views of Life Sciences learners and teachers on the use of foldscopes in the Life Sciences classroom during a practical lesson. The focus of the research is to illuminate how such problem-based approaches could enhance affective outcomes. This generic qualitative research study has elements of design-based research (DBR) as well as classroom action research (CAR), carried out by participating teachers to investigate the affordances of foldscopes. Data was collected using observations, teacher reflections, learner reflections, photographs and personal interviews. From an affective stance, this qualitative study used Engeström's third-generation Cultural-Historical Activity Theory (CHAT) as a research lens in order to identify factors that promote or inhibit the use of foldscopes in the Life Sciences classroom during a practical lesson.

This paper explores the use of systems theory to inform the mainstreaming of sustainability in a university's functions as it responds to sustainable development challenges in its local context. Offering a case study of Rhodes University, the paper shows how the use of systems models and concepts, underpinned by a critical realist ontology and an understanding of morphogenetic change processes, have the potential to enable universities to mobilise their operations to respond to local sustainability challenges. In this instance, the success of such an approach is shown to depend on commitments from the university community and the availability of enabling inputs, such as financial and human resources. The paper concludes with reflections and recommendations to inform further development of a newly emerging systems approach in sustainability mainstreaming at Rhodes University, and other institutions pursuing similar approaches and goals.

This article examines Umgeni Water's External Education Unit (EEU) to explore the potential of one approach to environmental education. The EEU uses a simple water quality monitoring kit to educate communities on the state of their rivers and catchment areas and warn them of potential dangers facing users of untreated water. (LZ)

Sustainable water security is critical for socio-economic development and livelihoods. It is in this context that a study was undertaken to examine sustainable water security in South Africa. Broadly, sustainable water security is sustainably having sufficient access to water without affecting the ecological balance of water resources and ecosystems. Sustainable water security is influenced by many factors that interact with and shape the availability, accessibility, and quality of water resources. This paper identifies and analyzes the factors influencing sustainable water security, focusing on one of the District Municipalities in the North West province in South Africa and making use of data collected from 384 households. We apply the logit regression model in analyzing the factors influencing sustainable water security among households. Our analysis is shaped by the Sustainable Livelihood Framework (SLF). Overall, there is an interplay of demographic, economic, and environmental factors which confirms the need for holistic and context-specific approaches to ensure sustainable access to clean and safe water for all. Therefore, targeted interventions and tailored policies are recommended to improve water security, particularly for vulnerable populations with larger households, lower education levels, and limited access to clean water sources. [ABSTRACT FROM AUTHOR]

This study analysed the water quality of 156 samples collected from 13 different points within the Chief Albert Luthuli Local Municipality between January and December 2021, focusing on compliance with the South African National Standard 241 (SANS 241). Microbiological assessments revealed widespread contamination, with heterotrophic plate counts (HPCs) exceeding the recommended range in nearly all samples. The median HPC levels were particularly concerning, with the untreated source (RE000) exhibiting a median of 2555 CFU/mL. Total coliforms and Escherichia coli were present at alarming levels, indicating significant faecal contamination; the highest total coliform count, 2420 CFU/100 mL, was recorded at RE000. Physically, while all samples complied with electrical conductivity standards (0–70 µS/cm), turbidity levels showed variability, with nine samples exceeding the acceptable threshold of 1 NTU. The highest turbidity, 7.55 NTU, was recorded at the untreated source (RE000). Chemically, pH levels fell within safe ranges (6.0–9.0), with all samples being compliant with standards. However, only one sample (E001) met the free chlorine standard of 0.3–0.6 mg/L, suggesting inadequate disinfection practices. The untreated source was classified as 'Unsuitable for drinking' (WQI = 207.27). These findings highlight the critical need for enhanced monitoring and remediation strategies to improve drinking water safety in the region. [ABSTRACT FROM AUTHOR]

Water treatment plants (WTPs) in developing countries play an important role in providing potable water to rural and urban areas. However, they often face many challenges, making them unable to produce quality water for consumers. We surveyed the performance of two rural WTPs from the Vhembe District Municipality, South Africa for eight months using secondary water quality data from each plant. Turbidity at the WTPs and most points of use (POU) exceeded the aesthetic (5 NTU) and operational (1 NTU) risk guidelines. Fluoride, iron, and manganese were within the regulated limits of < 1 mg/L, <3 mg/L and < 4 mg/L, respectively), but with signs of post-treatment change in the concentration of iron and manganese in the distribution system. At both WTPs, the free chlorine residual was below limits (<5 mg/L,), posing a risk of proliferation of pathogens in the distribution system. The results indicated problems with water disinfection at both WTPs. The study suggested the existence of challenges with the integrity, good operation, and maintenance of the water treatment system and distribution network. It is necessary to continuously monitor the performance of WTPs and POU to ensure public health and safety. [ABSTRACT FROM AUTHOR]

Artificial neural networks (ANNs) are powerful data-oriented "black-box" algorithms capable of assessing and delineating linear and multifaceted non-linear correlations between the dependent and explanatory variables. Through the years, neural networks have proven to be effective and robust analytical techniques for establishing artificial intelligence-based tools for modelling, estimating, and projecting spatial and temporal variations in water bodies. Accordingly, ANN-based algorithms gained increased attention and have emerged as practical alternatives to traditional approaches for hydro-chemical analysis. ANNs are among the widely used computer systems for modelling surface water quality. Considering their wide recognition, resilience, flexibility, and accuracy, the current study employs a neural network-based methodology to construct a novel water quality index (WQI) model suitable for analysing South African rivers. The feed-forward, back-propagated multilayered perceptron model has three parallel-distributed neuron layers interconnected with seventy weighted links orientated laterally from left to right. First, the input layer includes thirteen neuro-nodes symbolising thirteen explanatory variables, including NH3, Ca, Cl, Chl-a, EC, F, CaCO3, Mg, Mn, NO3, pH, SO4, and turbidity (NTU). Second, the hidden layer consists of eleven neuro-nodes accountable for computational tasks. Lastly, the output layer features one neuron responsible for conveying network outcomes using a single-digit WQI rating extending from zero to one hundred, where zero represents substandard water quality and one hundred denotes exceptional water quality. The AI-based model was developed using water quality data obtained from six monitoring locations within four drainage basins under the management of the Umgeni Water Board in the KwaZulu-Natal Province of South Africa. The dataset comprises 416 samples randomly divided into training, testing, and validation sets using a proportional split of 70:15:15%. The Broyden–Fletcher–Goldfarb–Shanno (BFGS) technique was utilised to conduct backpropagation training and adjust synapse weights. The dependent variables are the WQI scores from the universal water quality index (UWQI) model developed specifically for South African river basins. The ANN demonstrated enhanced efficiency through an overall correlation coefficient (R) of 0.985. Furthermore, the neural network attained R-values of 0.987, 0.992, and 0.977 for the training, testing, and validation intervals. The ANN model achieved a Nash–Sutcliffe efficiency (NSE) value of 0.974 and coefficient of determination (R2) of 0.970. Sensitivity analysis provided additional validation of the preparedness and computational competence of the ANN model. The typical target-to-output error tolerance for the ANN model is 0.242, demonstrating an adequate predictive ability to deliver results comparable with the target UWQI, having the lowest and highest index ratings of 75.995 and 94.420, respectively. Accordingly, the three-layer neural network is scientifically sound, with index values and water quality evaluations corresponding to the UWQI results. The current research project seeks to document the processes used and the outcomes obtained. [ABSTRACT FROM AUTHOR]

There is a rapid spread of antibiotic resistance in the environment. However, the impact of antibiotic resistance in drinking water is relatively underexplored. Thus, this study aimed to quantify antibiotic resistance genes (ARGs) and antibiotic residues in two drinking water production facilities (NW-E and NW-C) in North West Province, South Africa and link these parameters to bacterial communities. Physicochemical and ARG levels were determined using standard procedures. Residues (antibiotics and fluconazole) and ARGs were quantified using ultra-high performance liquid chromatography (UHPLC) chemical analysis and real-time PCR, respectively. Bacterial community compositions were determined by high-throughput 16S rRNA sequencing. Data were analysed using redundancy analysis and pairwise correlation. Although some physicochemical levels were higher in treated than in raw water, drinking water in NW-E and NW-C was safe for human consumption using the South African Water Quality Guideline (SAWQG). ARGs were detected in raw and treated water. In NW-E, the concentrations of ARGs (sul1, intl1, EBC, FOX, ACC and DHA) were higher in treated water than in raw water. Regarding antimicrobial agents, antibiotic and fluconazole concentrations were higher in raw than in treated water. However, in NW-C, trimethoprim concentrations were higher in raw than in treated water. Redundancy analysis showed that bacterial communities were not significantly correlated (Monte Carlo simulations, p-value >0.05) with environmental factors. However, pairwise correlation showed significant differences (p-value <0.05) for Armatimonas, CL500-29 marine group, Clade III, Dickeya and Zymomonas genera with environmental factors. The presence of ARGs and antibiotic residues in the current study indicated that antibiotic resistance is not only a clinical phenomenon but also in environmental settings, particularly in drinking water niches. Consumption of NW-E and NW-C treated water may facilitate the spread of antibiotic resistance among consumers. Thus, regulating and monitoring ARGs and antibiotic residues in drinking water production facilities should be regarded as paramount. [ABSTRACT FROM AUTHOR]

This study reviews worldwide wetland park research from 1996 to 2022. A bibliometric analysis is conducted on 591 wetland park studies indexed in the Web of Science and Scopus databases. The study utilizes CiteSpace and VOSviewer tools to visualize and explore influential research focuses, themes, directions, and countries. The citation burst indicates that from 1996 to 2022, research on wetland parks transited from exploring basic community structures to complex ecosystem service assessments and the formulation of management strategies. Furthermore, over the past three years, wetland park research has seen a significant surge in studies investigating water quality, ecosystem services, and spatiotemporal analysis. Notably, the three most frequent keywords in research on wetland parks were China, South Africa, and biodiversity. These keywords reflect regions that enhance biodiversity via wetland parks. The spectral-clustering algorithm identifies carbon sequestration as a research focus, highlighting the vital role of wetlands in the carbon cycle. Most authors work in developed countries' institutions, but some are from developing countries like China, South Africa, and India. The findings suggest that economic development is crucial in wetland park construction and significantly influences related research. Developed countries may offer more PhD positions to developing countries' researchers in the field and raise their awareness about wetland conservation. Given the holistic requirements of wetlands, this research recommends that educators should adopt an interdisciplinary approach in the future when nurturing wetland staff. Additionally, the study maps out the primary areas of interest in wetland park research, including environmental science, ecological economics, forestry, wetlands, tourism, and management. New artificial intelligence and digital technologies should be developed for wetland park research. This study fills a research gap: quantitative and visualized knowledge-mapping and bibliometrics on wetland parks are scarce. Additionally, no previous study has explored the relationship between wetland park research and the economic development of countries. [ABSTRACT FROM AUTHOR]

Nutrient enrichment is considered to be one of the most serious threats to freshwater ecosystems. The increasing agricultural and other human activities in the Steelpoort sub-catchment of the Olifants River Basin has led to serious impacts on water quality. The spatial and seasonal variability of nutrient concentrations in the Dwars, Spekboom and Steelpoort rivers in South Africa were analyzed. Four monitoring sites per each river were selected to assess the impact of human activities on nutrient levels in the rivers during the wet and dry seasons. The samples were analyzed to determine the concentrations of nitrates, nitrites, ammonia and ortho-phosphates. Trends in nutrient concentrations varied among the sites and rivers, and there were significantly higher levels of nutrients detected at sites with high human activities. Generally, higher concentrations of nutrients were recorded during the wet season in the Dwars and Steelpoort rivers and higher concentrations of nutrients were recorded in the Spekboom River during the dry season. The most likely cause of increasing nutrient enrichment are effluent from agricultural fields, partially treated and untreated sewage. Though nutrient levels recorded were low, some sites had concentrations that exceeded the recommended limits. It is therefore important that proper management measures should be implemented to reduce wastes discharged into the rivers. [ABSTRACT FROM AUTHOR]

River water quality modelling relies on a good dataset for model input, calibration and validation to develop a reliable model. Determination of data requirements, and data sourcing towards this purpose in South Africa, are not elementary. Data availability is key throughout the modelling processes, making the sourcing of good data equally imperative. This paper provides starting considerations, and compiles a list of available data sources applicable to river water quality modelling in South Africa. It also provides a background on the included data sources and a general overview of the extent of the databases. [ABSTRACT FROM AUTHOR]

The Vaal Dam catchment, which is the source of potable water for Gauteng province, is characterized by diverse human activities, and the dam encounters significant nutrient input from multiple sources within its catchment. As a result, there has been a rise in Harmful Algal Blooms (HABs) within the reservoir of the dam. In this study, we employed time series analysis on nutrient data to explore the relationship between HABs, using chlorophyll-a (Chl−a) as a proxy, and nutrient levels. Additionally, Chl−a data extracted from Landsat-8 satellite images was utilized to visualize the spatial distribution of HABs in the reservoir. Our findings revealed that HAB productivity in the Vaal Dam is influenced by the levels of total phosphorus (TP) and organic nitrogen (KJEL_N), which exhibited a positive correlation with chlorophyll-a (Chl−a) concentration. Long-term analysis of Chl−a in-situ data (1986–2022) collected at a specific point within the reservoir showed an average concentration of 11.25 μg/L. However, on certain stochastic dates, Chl−a concentration spiked to very high values, reaching a maximum of 452.8 μg/L, coinciding with elevated records of TP and KJEL_N concentrations on those dates, indicating their effect on productivity levels. The decadal time series and trend analysis demonstrated an increasing trend in Chl−a productivity over the studied period, rising from 4.75 μg/L in the first decade (1990–2000) to 10.51 μg/L in the second decade (2000–2010), and reaching 16.7 μg/L in the last decade (2010–2020). The rising averages of the decadal values were associated with increasing decadal averages of its driving factors, TP from 0.1043 to 0.1096 to 0.1119 mg/L for the three decades, respectively, and KJEL_N from 0.80 mg/L in the first decade to 1.14 mg/L in the last decade. Satellite data analysis during the last decade revealed that the spatial dynamics of HABs are influenced by the dam's geometry and the levels of discharge from its two feeding rivers, with higher concentrations observed in meandering areas of the reservoir and within zones of restricted water circulation. [ABSTRACT FROM AUTHOR]

Rivers in Africa have experienced dire pollution as a result of the poor management of wastewater effluent emanating from water resource recovery facilities (WRRFs). An integrated wastewater resource recovery model was developed and applied to identify ideal wastewater resource recovery technologies that can be used to recover valuable resources from a mixture of wastewater effluents in a case study in the Burgersfort WRRF in the Limpopo province, South Africa. This novel model incorporates the process of biological nutrient removal (BNR) with an extension of conventional methods of resource recovery applicable to wastewater. The assessment of results of effluent quality from 2016 to 2022 revealed that ammonia, chemical oxygen demand, total coliform, fecal coliform, and Escherichia coli levels were critically non-compliant with the permissible effluent guidelines, indicating a stable upward trend in terms of concentrations, and scored a very bad wastewater quality index rating. All variables assessed showed a significant loading, except for orthophosphates, and significant correlations were observed among the variables. The results of the integrated wastewater resource recovery model revealed a high probability of reclaiming recoverable resources such as nutrients, sludge, bioplastics, biofuel, metals, and water from wastewater, which have economic, environmental, and social benefits, thereby improving the effluent quality of a WRRF. [ABSTRACT FROM AUTHOR]

While natural floods play a crucial role in shaping the composition of aquatic communities, the most rivers worldwide are regulated or dammed for anthropogenic purposes, resulting in alterations to the biological and chemical composition of these ecosystems. Studies have demonstrated various negative effects of river regulation on aquatic invertebrate communities globally. However, there is a scarcity of research in Africa, despite its vulnerability to anthropogenic impacts. This study aimed to compare aquatic invertebrate communities in the Phongolo River, an impacted regulated river, and the Usuthu River, a less impacted unregulated river, in South Africa. It further aimed to ascertain whether Lake Nyamithi, a naturally saline lake receiving water from both of the aforementioned systems, exhibited a stronger similarity to one of the two rivers in terms of its aquatic invertebrate composition. Aquatic invertebrate and water samples were collected from 2012 to 2018 over several surveys. The Usuthu River demonstrated a diverse and sensitive aquatic invertebrate community, emphasising its high conservation value. The Phongolo River demonstrated effects of anthropogenic impact, with taxa more resilient to changes in water quality and flow compared to the Usuthu River. Mismanagement and excessive water use may lead to the loss of any remaining sensitive aquatic invertebrate communities in this river. The presence of invasive molluscan in the Phongolo River and Lake Nyamithi also poses a threat to the native aquatic invertebrate communities. These invasive species are currently absent from the Usuthu River although other invasive species, such as the Australian redclaw crayfish, are found in both river systems. Lake Nyamithi displayed a unique aquatic invertebrate community, distinct from both rivers and their floodplains. This study provides important baseline information on the Usuthu River's aquatic invertebrates and emphasises the need to maintain adequate water flow in rivers and floodplains to protect biodiversity and sensitive species. [ABSTRACT FROM AUTHOR]

Mine closure in the Witwatersrand Goldfields of South Africa has resulted in an acid mine drainage (AMD) legacy that is difficult to manage and costly to address. As a short-term measure, three large high-density sludge (HDS) plants were erected that treat 185 megalitres of AMD per day (ML/day), at great cost to taxpayers. Longer-term solutions are sought, as the salt load to the Vaal River System is unacceptable. Long-term modelling was used to assess whether the untreated and HDS-treated AMD could be used for irrigation and to determine the scale of the potential opportunity. The Goldfields waters are not very acidic, and simulations indicate it should be feasible to utilise even the untreated water for irrigation, especially if growers commit to applying limestone to their fields. HDS treatment lowers the corrosivity and trace element concentrations, and because the water is gypsiferous, double cropping will precipitate more than a third of the salts in solution as gypsum in the soil profile, thereby reducing salt load to the water environment. The potential irrigated area depends on the cropping system; it is about 9000 ha for rotational cropping and 30,000 ha for supplemental maize irrigation. It is prudent to seriously consider irrigation as a potential long-term water management option for the Goldfields AMD. [ABSTRACT FROM AUTHOR]

The water quality of the Kaalspruit River, situated in the Gauteng province, South Africa, has been in question over previous years with concerns about the health risks potentially posed by the level of pollution to the surrounding communities. The study aimed to conduct a physico-chemical assessment of water and sediment in the river. In-situ water quality parameters were measured in the field using a multi-parameter water quality meter, while other parameters, such as organic and inorganic constituents were analysed at SANAS accredited laboratories. Water quality results revealed generally poor conditions with minimal seasonal variations, showing low dissolved oxygen and some metal concentrations present in toxic levels. Furthermore, the levels of faecal coliforms and E. coli were beyond the detectable levels in sampling areas of close proximity to informal settlements. Overall, this study revealed that the river system is of poor quality as a result of anthropogenic activities surrounding the Kaalspruit. [ABSTRACT FROM AUTHOR]

Intermittent Water Supply (IWS) is characterised as drinking water distribution systems that are supplied with water for less than 24 hours/day on average. The filling transition from non-supply to pressurised supply is a period of hydraulic instability that negatively impacts water quality, deteriorates infrastructure integrity and intensifies social inequalities. Understanding the factors contributing to the severity of impact from filling is vital to develop effective management strategies. This paper investigates the hydraulic phenomena induced during the short-term IWS filling period and how this behaviour can be exacerbated by elevation and other hydraulic system factors, such as velocity and pressure. Controlled laboratory experiments conducted in the UK and field studies performed in operational networks across South Africa are presented. Results demonstrate the crucial role elevation plays in the network response during the filling transition, emphasising the need for greater consideration of elevation in IWS and well-maintained air relief valves in strategic locations. [ABSTRACT FROM AUTHOR]

The study aimed to assess the impacts on four township areas under Emfuleni Local Municipality of poor water quality from inadequate wastewater management. The failure of the municipality to upgrade and maintain the wastewater treatment facilities has been ongoing for many years and raw sewage spills have been observed on the streets. The objectives of the study were addressed through questionnaires directed at obtaining feedback from household and small business participants. In total, 260 respondents participated, and the results showed differences in the perceptions of impacts due to poor water quality per area of residence; these were significant at 99% confidence interval. Results showed concerns about the impact of wastewater and poor infrastructure on the livelihoods of both residents and business owners. In conclusion, the infrastructural problems resulting in water quality issues have caused severe socio-economic strain on residents and businesses alike. [ABSTRACT FROM AUTHOR]

Anthropogenic nutrient loading from urbanised coastal watersheds can negatively impact downstream estuarine ecosystems. The urbanised and low-inflow Swartkops Estuary in South Africa is one such example of an ecosystem suffering severe anthropogenic water quality alterations. Substantial inorganic nutrient loads (209 kg DIN d−1; 127 kg DIP d−1) are discharged into the estuary from three upstream wastewater treatment works and an adjacent stormwater canal. As a result, previous studies have indicated an increasing frequency and magnitude of phytoplankton bloom conditions (> 20 µg Chl-a l−1), yet the determinants of this are not fully understood. As such, the drivers of phytoplankton community dynamics–including harmful algal blooms (HABs)–in the Swartkops Estuary were evaluated by investigating seasonal and twice-weekly data collected over a two-and-a-half-year period. Eutrophic levels of dissolved inorganic nitrogen (DIN: > 100 µM) and phosphorus (DIP: > 85 µM) entered the estuary throughout the study period. Despite low DIN:DIP ratios (< 1:1), high-biomass HABs of Heterosigma akashiwo (max. 2120 µg Chl-a l−1) and Cyclotella sp. (max. 687 µg Chl-a l−1) were frequently recorded in the meso- to polyhaline (salinity: 5–23) middle and upper reaches. These events facilitate extreme dissolved oxygen conditions (supersaturated to hypoxic), increased turbidity, and occasional mass fish mortality events. This shift to an undesirable alternate stable state is attributed to the synergistic interaction between drought conditions, altered hydrodynamics, and anthropogenic nutrient loading. Innovative management interventions (e.g. wastewater reclamation, constructed wetlands, dual nutrient reduction strategies) are required to reduce the severity of these eutrophic symptoms. [ABSTRACT FROM AUTHOR]

Landscape fragmentation impacts freshwater habitats and their quality, affecting aquatic insect assemblages. Adjacent terrestrial areas are important secondary habitats where amphibiotic insects mature, feed, find mates, and move to locate aquatic breeding habitats. Using a factorial design with 27 small and large ponds within small and large natural patches in an exotic tree plantation-fragmented landscape of South Africa, and odonates as model organisms, we investigated (1) how pond size/natural terrestrial patch size interaction affects odonate diversity patterns versus habitat quality variables, and (2) determined whether anisopterans and zygopterans respond differently to landscape fragmentation. Species richness was similar among ponds. However, odonate abundance was highest in large ponds regardless of natural terrestrial patch size. Zygopteran functional richness and diversity was driven by pond and natural patch size, suggesting that zygopterans are sensitive to landscape fragmentation. In contrast, anisopterans were more resilient to fragmentation and more likely to select suitable habitats following water chemistry and vegetation characteristics. Overall, large ponds were occupied by different odonate assemblages compared to small ponds, and occupancy was strongly associated with mobility traits. These findings emphasize that ponds in both small and large natural terrestrial patches have conservation value. A pondscape that represents various pond sizes is important for maintaining regional odonate diversity. Pond conservation needs to be considered in the wider terrestrial context, which host a range of important secondary habitats. Adjacent natural terrestrial habitats also connect nearby aquatic habitats, which enable insects to move across the landscape in response to natural and artificial drivers. [ABSTRACT FROM AUTHOR]

The quality of surface water has a significant impact on human health and the entire ecological system. Sewer spillages from the surrounding informal settlements discharging into the river, carrying high concentrations of fecal coliforms, are one of the major causes of extreme pollution in the rivers of South Africa. These informal settlements are common in many developing countries, and they are usually located near waterways to compensate for basic demands for water, sanitation, and recreational space, where municipal infrastructure lags behind urban growth. One major problem has been poor sanitation and poor waste disposal practices in the informal settlements, which has led to the contamination of water resources. This study aims to assess the extent to which poor sanitation in informal settlements impacts the water quality of South African rivers, given the rapid rise in population and unemployment rate. The study also highlights health and environmental issues in the local regions caused by poor sanitation. Contamination of water bodies is associated with serious health problems and fatalities. Therefore, there is a need for frequent monitoring and management of waste products discharged into the neighboring aquatic environments. [ABSTRACT FROM AUTHOR]

This study focuses on the evaluation of trace metals as well as microbial contamination of groundwater. Groundwater samples were collected from 17 boreholes. The microbial quality was tested using membrane filtration method. Higher levels of contamination for both E. coli and total coliform was recorded in the wet season. Majority of the boreholes had nitrate levels above the regulatory guideline value of the World health Organisation and the South African National Standards. The water type was established by Piper plot which showed the predominance of a magnesium bicarbonate water type, with alkaline earth metals dominating the alkali metals, as well as the weaker acids (bicarbonates) dominating the stronger ones (Sulphates and chlorides). Most of the trace metals detected were in compliance with the regulatory standard except for aluminium (0.41–0.88 mg/L). The hazard quotient and Hazard indice exceeded 1 mostly for children in both season which implies a possible non-carcinogenic health risk is associated with the continuous consumption of the water resource. The estimations of carcinogenic risk (CRing) for Cr and Pb exceeded the carcinogenic indices of 10−6 and 10−4 which could pose adverse effects on human health for both children and adults. Therefore, it is recommended that measures should be implemented to reduce the risk. [ABSTRACT FROM AUTHOR]

The uMgeni River is one of the most polluted freshwater ecosystems in KwaZulu-Natal. The study aims to assess the response of Clarias gariepinus to water contamination at the Nagle and Inanda dams using selected biomarkers. Samples were collected and preserved as per the analyses to be carried out. Generally, Nagle Dam showed good quality water compared to Inanda Dam. The Inanda Dam population showed a relatively higher prevalence of alterations in the gills and liver than that from Nagle Dam. The degree of alterations showed some variability within each population, however, there was no significant difference (p>0.05) between the two populations. Organ indices of 20 denoting moderate alterations were observed for both populations. Although the mean AChE activity and VtG induction showed no significant difference between the two populations (p>0.05); the lowest AChE activity and the highest VtG level, were observed in the Inanda Dam populations. Both histopathologic and biochemical biomarkers show signs of severely compromised fish health in the Inanda Dam compared to those from Nagle Dam. It is thus, evident that the tributaries feeding the uMgeni River downstream of Nagle Dam are resulting in the increase of pollution level in the Inanda Dam. [ABSTRACT FROM AUTHOR]

This study focused on assessing the extent of pollution in both flowing and non-flowing surface water within the Matjhabeng mining area of South Africa, with particular emphasis on the substantial impact of gold mine tailings. A comprehensive analysis of physical water-quality attributes, including potentially toxic elements (PTEs), and relevant pollution risk indices was undertaken. To comprehensively elucidate the potential risks to aquatic organisms and human health, a risk assessment framework predicated upon the source–pathway–receptor model was developed. Principal Component Analysis (PCA) was employed as a multivariate statistical tool to discern the potential origins of PTE contamination within the environment. The results substantiate pronounced pollution manifestations within the surface water milieu of the Matjhabeng mining area. Specifically, concentrations of critical PTEs, such as arsenic, cobalt, copper, iron, selenium, and zinc, exhibited transgressions of the regulatory thresholds stipulated by both the South African Department of Water Affairs and Forestry (DWAF) and the Canadian Council of the Ministers of the Environment (CCME). Additionally, concentrations of the aforementioned elements exceeded the stipulated DWAF guidelines for irrigation water usage. Pollution indices, encompassing the Single-Factor Pollution Index and the Nemerow Integrated Pollution Index, discerned moderate contamination stemming from As, while remarkably elevated pollution levels were identified for selenium. PCA elucidated 94.5% of the aggregate variance, revealing cobalt, copper, nickel, and zinc as coalescing within PC1, indicative of a common anthropogenic provenance that is conceivably linked to historical gold mine tailings. PC2 exhibited an aggregation of chromium, iron, and lead, reaffirming this shared anthropogenic etiology. The third PCA component was characterized by selenium, followed by arsenic and magnesium in the fourth. The resultant PTE contamination underscores a profound ecological and public health risk, impacting both the aquatic ecosystems and the local community within the precincts of the Matjhabeng Local Municipality (MLM) area, with consequential amplification of susceptibilities to deleterious health consequences. Urgent and concerted interventions are imperative to ameliorate the emergent decline in surface-water quality within the MLM locale. The adoption of nature-based remediation paradigms holds promise for efficaciously elevating water quality, ameliorating community health, and underpinning the long-term economic viability of the region. [ABSTRACT FROM AUTHOR]

A survey of the quality of water flowing from micro-system types to the ocean, along the subtropical east coast of South Africa, showed a wide variation in the concentrations of total nitrogen, phosphorus and phytoplankton biomass in the different systems located, in many cases, only a short distance from each other along the coastline. The origins of the high phytoplankton growth indicate pollutants caused by the land-use in this highly populated coastal region. The main agricultural activities in the area are sugarcane, permanent orchards, and forestry. The levels of N and P in the water varied from ‘good’ to ‘poor’, i.e., TN 0.15–3.99 mg·L−1, TP 0.02–0.33 mg·L−1 and chlorophyll-a from 0 to almost 45 µg·L−1. Rapid coastal population densification appears to have been the cause of the pollution levels measured for total nitrogen, phosphorus, and phytoplankton biomass. Most of the micro-systems with a total modified peri-catchment above 80% were enriched by both TN and TP. While the hypothesis tested was that the main cause was residential development (e.g., septic tank effluent), it was not possible to show any statistical significance to support such a specific conclusion. Although these systems are small individually, the great number along the coastline warrants recognition as important sources of freshwater inflow and nutrients to the marine environment. [ABSTRACT FROM AUTHOR]

With water quality deteriorating rapidly at a global scale, river sections suited to serve as reference sites are being increasingly lost. It thus becomes critical to develop rapid methods to confirm that previously monitored sites continue meet the requirements of reliable reference sites. In the absence of pristine sites, 9 near-natural sites, as defined by the Kleynhans (1996) classification, were used as reference sites for the Luvuvhu River catchment to compare the quality of physico-chemical factors against a biological metric. Baetid mayfly community structure at a site was chosen as an index of water quality, since this family is common in all types of freshwaters, highly diverse and adapted to unpolluted running water. Baetid larvae were sampled monthly from stones-in-current biotopes across 9 sites for over 1 year, between December 2016 and January 2018. A Spearman’s correlation test was used to evaluate the relationship between physicochemical factors and identify redundant variables. Water quality standards were measured against the national water quality guidelines for aquatic ecosystems. We used a generalized linear model to determine the effect of physico-chemical variables on baetid species, and canonical correspondence analysis to show the relationships between baetid species, sites, and physico-chemical variables. A total of 3 039 individuals belonging to 12 mayfly species were recorded. Our findings indicated that while the physico-chemical factors were highly variable, they were within favourable ranges to reflect reference site conditions. While water temperature was the most important driver of baetid community structure in general, as it negatively affected their abundances, a subset of species (Pseudoponnota sp., Pseudocloeon sp., Acanthiops varius and Demoulinia crassi) showed clear responses to changes in TDS and stream width. We conclude that specific baetid species show good potential as biological indicators of reference sites and chronic water temperature stress, making assessment of reference sites easier. [ABSTRACT FROM AUTHOR]

The operationalization of water resource protection initiatives for surface water resource quality and equitable water quality allocation is critical for sustainable socio-economic development. This paper assessed Blesbokspruit River Catchment's water quality status, using the South African Water Quality standards and Water Quality Index (WQI). Protection levels for quality, and waste discharge for point sources were set and evaluated using the total maximum daily loads (TMDLs) and chemical mass balance (CMB) techniques, respectively. The study found that the water quality results for the analysed physico-chemical parameters (Na+, Ca2+, Mg2+, Cl−, F−, pH, EC, SO42−) of the data collected from 2015 to 2022 were within the limits of the water quality standards, except for NO3− and PO42−. The water quality from the study area was categorized as acceptable for drinking purposes with the WQI of 54.80. The application of the TMDL approach resulted in the 77.96 mS/m for electrical conductivity (EC), 9.92 mg/L for phosphate (PO42−), and 15.16 mg/L for nitrate NO3− being set as the protection levels for the catchment. The CMB was found to be a useful tool for the evaluation of point source discharges into water resources. The study recommends the application of TMDL and CMB techniques in water resource protection practice. [ABSTRACT FROM AUTHOR]

This study examined the impact of community participation on water and sanitation services in the Mantsopa Municipality. Qualitative methods, including interviews with community representatives and municipal officials, were used to gather and analyze data thematically. The results indicated that community involvement can enhance service delivery and improve resident satisfaction. However, the quality of water and sanitation facilities remains a concern due to long-standing maintenance and population growth issues. Barriers to decision-making were identified, including limited funding, public awareness and education, socio-cultural, political and economic constraints which discouraged participation. Collaboration among government agencies, civil society organizations, and local communities is necessary to overcome these systemic barriers. Municipal authorities should consider the cultural, social, political, and economic factors and drivers at play in redesigning the water supply and sanitation systems to accommodate population growth. [ABSTRACT FROM AUTHOR]

The present study aims at evaluating the quality of shallow groundwater (SGW) and its suitability for irrigation purpose in the most urbanised part of Johannesburg city, South Africa. The SGW samples were collected in three consecutive years and analysed for 20 selected physicochemical parameters, and heavy metals. The results were compared with the South African water quality, and Food and Agricultural Organization irrigation water quality guidelines, and standard indices derived from laboratory outputs. The results of the study show that all physiochemical parameters and heavy metals were within the limits set by both guidelines for irrigation purposes, except for potassium (3.58 mg·dm-3) and manganese levels (3.152 mg·dm-3). The calculated irrigation parameter values of sodium adsorption ratio (SAR), sodium percentage (Na%), residual sodium carbonate (RSC), magnesium hazard (MH), Kelly's ratio (KR) and permeability index (PI) were within the permissible range of irrigation water quality standards. The findings of this study provide helpful information for decision-makers such as utilisation of the studied groundwater for irrigation uses. [ABSTRACT FROM AUTHOR]

Eutrophication-driven harmful algal blooms (HABs) can have secondary effects on larval fishes that rely on estuaries as nurseries. However, few studies worldwide have quantified these effects despite the global rise in eutrophication. This study presents a novel approach using biochemical body condition analyses to evaluate the impact of HABs on the growth and body condition of the larvae of an estuarine resident fish. Recurrent phytoplankton blooms of Heterosigma akashiwo occur in the warm-temperate Sundays Estuary on the southeast coast of South Africa. The response in body condition and assemblage structure on larval estuarine roundherring (Gilchristella aestuaria) was measured in conjunction with bloom conditions, water quality and zooplanktonic prey and predators. Larvae and early juveniles were sampled during varying intensity levels, duration and frequency of hypereutrophic blooms. This study demonstrated that extensive HABs could significantly impact larval roundherring, G. aestuaria , by decreasing larval nutritional condition and limiting their growth, resulting in poor grow-out into the juvenile phase. Poor condition and growth may likely affect recruitment success to adult populations, and since G. aestuaria is an important forage fish and zooplanktivore, poor recruitment will hold consequences for estuarine food webs. [ABSTRACT FROM AUTHOR]

There are growing concerns on contribution of vegetation dynamics to atmospheric turbidity and quality of regional water towers. The study sought to determine the trends in the MODIS/TERRA-derived normalized difference vegetation index (NDVI) and aerosol optical depth (AOD) for Lesotho Highland over 2000–2020. The predictive relationship between the two variables was also examined using regression analysis. Irrespective of yearly AOD patterns, the AOD showed biphasic patterns peaking between mid-winter to early spring (July–October) (highest) and autumn (Feb–April) (next highest), and lowest in the summer (Nov–January). The monthly NDVI was largest in January–March (summer–early fall) with smaller values in winter and spring. This seasonality can be related to the peak of anthropogenic biomass combustion during the winter and strong winds during the spring and early summer. The AOD relationship with NDVI showed quadratic patterns peaking and plunging with changes in season. About 30–80% (R2 = 0.3–0.8%) changes in annual AOD from 2000 to 2020 were explainable by the dynamics of NDVI indicating that increased NDVI contributes to about a 50% decrease in AOD in the Lesotho Highlands. However, an outlier trend was observed in 2007 (R2 = 13%). Incidences of high AOD in months of high NDVI may be indicative of traveling aerosols, i.e., aerosols from non-local sources/activity. On the other hand, high AOD in months of low NDVI implicates local aerosol sources. Trend relationship studies on vegetation loss and AOD in mountain areas of other regions could improve knowledge of contaminant dynamics and risk implications for downstream populations. [ABSTRACT FROM AUTHOR]

The Groot Letaba River catchment in South Africa, is known for agricultural activities, such as citrus and avocado farming. These activities are causing degradation of the river, especially near areas of commercial farming and human settlements. Benthic macroinvertebrates are good water quality bioindicators and are used to assess the health of aquatic ecosystems. The current study assessed river health of the river using macroinvertebrate community structure in relation to environmental variables. The macroinvertebrates were distributed among 42 families and 13 orders. The results revealed distinct spatial variation among the sampling sites and their associated macroinvertebrate communities, with the downstream having the least taxa richness and most of the tolerant taxa. The family richness and diversity were higher in the upstream and midstream sites. The changes in macroinvertebrate assemblages were primarily due to changes in water quality as a result of environmental factors, such as total dissolved solids (TDS), conductivity, dissolved oxygen and total nitrogen, and organic matter from agricultural activities. [ABSTRACT FROM AUTHOR]

Preserving water quality, which has at least four of the ten characteristics of a "wicked problem", is fundamental for economic development, ecosystems function, and human wellbeing. Consequently, identifying suitable public policies or technological solutions that can maintain or restore affected ecosystems, especially in river catchments, is a huge challenge. Understanding diverse stakeholder perspectives on important aquatic ecosystem services is critical to improving water governance and quality. This study uses the Q-methodology to identify and analyze perspectives about aquatic ecosystem services in the Olifants River catchment, one of the most important and polluted in South Africa, across six diverse stakeholder groups competing for its limited water resources. The Q methodology is a semi-qualitative methodology that can systematically recover detailed views of the subjective perceptions diverse stakeholder groups hold on a given topic. Our results suggest existence of three significant and conflicting perspectives. The "conservationists" prioritize regulation and supporting services, the "water users" give highest priority to water for domestic and other private uses, while the "planners" rank mastering the environment for societal benefits highest. Equally importantly, our results suggest the possibility of solutions that can deliver services ranked highly by some stakeholders without compromising the welfare of others who hold neutral perspectives towards them. [ABSTRACT FROM AUTHOR]

The overpopulation of urban centres accelerates land use patterns, slum creation and generation of contaminants. As such, this study seeks to investigate the impact of rapid urbanisation on climate variability and surface water quality around Mangaung metropolis. Remote sensing was employed to analyse land use land cover (LULC), normalized differential vegetation index (NDVI) and normalized differential water index (NDWI) changes for a period of 30 years in the Mangaung metropolis. Furthermore, the historical water quality of important rivers and dams were studied in respect of urban contamination. LULC revealed that the urban areas increased exponentially which led to increased loss of vegetation cover and shortage of water availability. The rainfall and water type evolution suggests the influence of urbanisation. This suggests urbanisation accelerates the loss of vegetation cover, thus causing an increase in temperature and reduction in the amount of rainfall, thereby reducing the surface water quantity in the study area. [ABSTRACT FROM AUTHOR]

Water loss due to onsite leakage is a problem in the effective management of potable water mostly in semi-arid and arid countries of the world whose quantity of freshwater is depleted, and recharge is highly variable. This study assessed the quality and quantity of water loss in an academic institution due to onsite leakage resulting from various drivers such as leaks, corrosion, pressure, ageing infrastructure, and student attitude. An observational approach was used for water loss analysis. Samples were collected from each point from which water is lost and analyzed for physicochemical parameters, indicator microbes, and trace metals using standard procedures. It was observed that a high amount of water is lost in the study area which was partly influenced by high water pressure, the corrosion of taps and faucets, tap faults, and leaks. A total water loss of 9013.56 L/day in three selected residences of the institution was recorded. The wasted water was found to be of good quality with no harmful contamination. The Metal Pollution Index (MPI) showed that the water poses no threat from trace metals with a maximum MPI value of 7.76. The sampled water quality complied to the South African National Standard and World Health Organization standards for drinking water. The hazard quotient and hazard index both showed a level less than one, implying no possible non-carcinogenic risk associated with the consumption of the water. The wasted water from the institution's residences is therefore of a very high quality and needs to be conserved for better usage. [ABSTRACT FROM AUTHOR]

Freshwater ecosystems are facing degradation from human activities in the form of alterations of flow regimes, changes in land-use, and intensive water abstraction, in turn generating adverse effects on biodiversity and ecological functionality. Efficient assessment of river/stream ecosystem response to such anthropogenic changes is urgently needed. Many human activities that have an effect on water quality and river health are increasing along the Mohlapitsi River, which used to be one of the rivers with good water quality in South Africa. The aim of the study was to assess spatial variation in macroinvertebrate assemblages in relation to water quality of the Mohlapitsi River. A combination of canonical correspondence analysis and univariate analyses were used to examine the macroinvertebrate assemblages at six different sites of the Mohlapitsi River. The spatial difference in macroinvertebrate abundance was mostly related to changes in water quality. The number of taxa and the diversity of macroinvertebrates remained relatively high across the river as compared to other rivers in the Olifants River System. The midstream and downstream sites were mostly dominated by macroinvertebrates tolerant to disturbance/pollution. The most abundant family was the Thiaridae (about 60%) and mainly occurred in the midstream and downstream sites of the river (more disturbed sites). The study showed a higher evenness index in the upstream than the midstream and downstream sites which is an indication of good water quality at the upstream sites of the river. The results suggest that the river is being subjected to a moderate environmental pollution, which requires continuous assessment and monitoring to determine causes and initiate remedial measures. [ABSTRACT FROM AUTHOR]

Water is an important resource, and it is a worldwide struggle to provide water of good quality to the whole population. Despite good governing laws and guidelines set in place to help protect the water resources and ensure it is of good quality for various consumers, the water quality in South Africa is worsening due to lack of management. The deteriorating infrastructure is becoming progressively worse, due to corruption and insufficient funds. The ever-increasing number of toxicants, as well as the identification of emerging chemicals of concern, are also challenges South Africa is facing. Chemical analysis cannot determine the total biological effect of a mixture of chemical compounds, but this shortcoming can be addressed by adding effect-based methods (EBMs) to water quality monitoring programmes. In this paper, the current status of water quality monitoring in South Africa is discussed, as well as the capacity of the country to add EBMs to its water quality monitoring programmes to protect and improve human and animal life. Created in Biorender.com [ABSTRACT FROM AUTHOR]

Uneven distribution of precipitation and climate change have led to water shortages, adversely impacting numerous countries worldwide. Rooftop rainwater harvesting (RWH) has emerged as a crucial method for providing water for domestic uses. However, there are concerns about the quality of rainwater collected from roofs, as it may be contaminated with pollutants such as metals and microbiological pathogens. This study investigates the common roof types used as catchments for rainwater harvesting with the aim of establishing the quality and usefulness of the harvested water resource. Compliant levels of major and trace metals were recorded across various roof types in the three study areas. Metals of concern, such as lead (below detection limit to 0.69 μg/l), arsenic (0.06-0.13 μg/l), and cadmium (0.02-0.13 μg/l), were also within acceptable limits at all study sites. However, the average levels of E. coli detected ranged from 4.32 to 27.97 cfu/100 ml, exceeding the recommended limits set by both the World Health Organization and the South African National Standards. The trace metal levels in water collected from slate roofs were slightly higher than those from other roof types for most of the metals studied. The quality of the water obtained from various roof types indicates it is suitable for all domestic purposes, including drinking after disinfection. No significant differences were observed in the water quality across the different rooftops in the study areas. PRACTITIONER POINTS: Different roofing materials did not significantly affect the quality of the harvested rainwater. Water quality of the harvested rainwater complied with regulatory standards except for microbial water quality parameters. Rainwater can be used for several domestic purposes without treatment except for drinking purposes where it should be treated with a simple point-of-use water treatment system. First flush should be discarded as it impacts greatly on the water quality parameters determined. Rainwater harvesting offers an alternative and supplementary form of water supply in the semi-arid region of South Africa., (© 2025 The Author(s). Water Environment Research published by Wiley Periodicals LLC on behalf of Water Environment Federation.)