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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]

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]

South African rivers generally receive waste from inadequate wastewater infrastructure, mines, and farming activities, among others. The uMsunduzi River in KwaZulu-Natal, South Africa, is among these recipients with recorded poor to very poor water quality. To identify parts of the uMsunduzi River that are polluted by Cryptosporidium and Escherichia coli (E. coli), this study mapped out pollutants emanating from point and non-point sources using the Soil and Water Assessment Tool (SWAT). Streamflow calibration in the upper and lower reaches of the catchment showed good performance with R² of 0.64 and 0.58, respectively. SWAT water quality output data were combined with a Quantitative Microbial Risk Assessment (QMRA) to understand the microbial health implications for people using river water for drinking, recreational swimming, and non-competitive canoeing. QMRA results for Cryptosporidium and pathogenic E. coli showed that the probability of infection for most users exceeds the acceptable level for drinking and recreation as outlined in the South African water quality guidelines, and by the World Health Organization (WHO). The results of this study can be used as a baseline to assess the economic and health implications of different management plans, resulting in better-informed, cost-effective, and impactful decision-making. [ABSTRACT FROM AUTHOR]

The Ga-Selati River is subjected to different forms of pollution from mining, industrial and agricultural activities, and human settlements. The objectives of the study were to assess heavy metal pollution and to determine possible sources of pollutants in the river. Water and sediment samples were collected and analysed for the following selected metals: arsenic (As), chromium (Cr), iron (Fe), manganese (Mn), nickel (Ni) and zinc (Zn) using sequential Inductively Coupled Plasma-optical emission spectrometry (ICP-OES). The enrichment factor (EF) and geo-accumulation index (Igeo) were used to determine the level of metal pollution in the sediment. The results indicated that Cr and Ni were the most accumulated elements in the sediments, and the midstream sites (S4 and S5) showed a much higher pollution level than the upstream and downstream sites. The main sources of pollutants were mining, wastewater/sewage and agricultural discharges. This may pose a serious threat to the river and health risk to the nearby rural communities, which rely on the river, especially for drinking water. Proper management strategies to reduce pollution is therefore necessary. [ABSTRACT FROM AUTHOR]

Anthropogenic activities in catchments used for drinking water production largely contaminates source waters, and this may impact the quality of the final drinking water product. These contaminants may also affect taxonomic and functional profiles of the bacterial communities in the drinking water. Here, we report an integrated insight into the microbiome and water quality of four water treatment plants (NWC, NWE, WCA and NWG) that supply portable water to communities in South Africa. A new scoring system based on combined significant changes of physicochemical parameters and microbial abundance from raw to treated water was used to evaluate the effectiveness of the treatment plants at water purification. Physicochemical parameters which include total soluble solids, turbidity, pH, nitrites and phosphorus among others, were measured in source, treated, and distributed water. There were general statistically significant (P ≤ 0.05) differences between raw and treated water, demonstrating the effectiveness of the purification process. Illumina sequencing of the 16S rRNA gene was used for taxonomic profiling of the microbial communities and this data was used to infer functional attributes of the communities. Structure and composition of the bacterial communities differed significantly (P < 0.05) among the treatment plants, only NWE and NWG showed no significant differences (P > 0.05), this correlated with the predicted functional profile of the microbial communities obtained from Phylogenetic Investigation of Communities by Reconstruction of Observed States (PICRUSt), as well as the likely pollutants of source water. Bacteroidetes, Chlorobi and Fibrobacteres significantly differed (P < 0.05) between raw and distributed water. PICRUSt inferred a number of pathways involved in the degradation of xenobiotics such as Dichlorodiphenyltrichloroethane, atrazine and polycyclic aromatic hydrocarbons. More worryingly, was the presence of pathways involved in beta-lactam resistance, potential pathogenic Escherichia coli infection, Vibrio cholerae infection, and Shigellosis. Also present in drinking and treated water were OTUs associated with a number of opportunistic pathogens. [ABSTRACT FROM AUTHOR]

This paper presents the levels of detection of selected agricultural pesticides in river and tap water in the Letsitele, Lomati and Vals–Renoster catchments, South Africa. Agriculture plays a major role in the development of communities through job creation and poverty eradication. However, exposure to agricultural pesticides can result in serious human health and environmental effects. This study, therefore, identified critical areas where specific pesticides might result in high environmental and human health risks. Three water catchment areas, namely, Letsitele, Lomati and Vals–Renoster, were identified for raw and tap water analysis. The results confirmed the presence of selected agricultural pesticides: atrazine, terbuthylazine, imidacloprid, metolachlor, simazine and alachlor. Although low concentrations of most of these pesticides were detected, pesticides such as atrazine, alachlor and simazine are known for endocrine disruption. A critical finding of this study is the detection of these pesticides in tap water (drinking water) of a primary school in the Lomati catchment. This reveals a high exposure potential for human health. It is thus recommended that further research be conducted to determine the potential health risks associated with these pesticides among vulnerable communities, through epidemiological studies. [ABSTRACT FROM AUTHOR]

When purifying water for potable use, wastewater is generated, due to the class of the water treatment plant and the quality of the source water. Midvaal Water Company recycled wastewater that included residue from the dissolved air flotation (DAF), sedimentation and filtration processes in an attempt to save water and reduce costs. The aim of this study was to determine functionality and water quality of such a wastewater recycling system. Samples were collected for analysis, at the sections that contributed to the total wastewater system as well as after various treatment processes. The water quality of these samples was determined, as well as the incidences of water quality failures of the final water, to establish whether the recycle stream that enters the plant together with the source water had any impact on the water quality after the different treatment processes. Data were grouped into periods prior to, during and after recycling to enable comparisons. The water quality of the recycle stream was poorer than that of the source water from the Vaal River with regard to the mean values for total chlorophyll, suspended solids, turbidity and dissolved organic carbon, but the sedimentation process of the wastewater system improved the wastewater quality by drastically reducing total chlorophyll, suspended solids and turbidity. The risk-defined compliance for the final water was excellent (≥95%), despite aluminium, turbidity and total chlorophyll failures of the final water quality during the recycling period. Total chlorophyll was identified as the largest risk during wastewater recycling, especially after the filtration process. It is evident from the data that wastewater recycling, which included wastewater from the DAF, into the main inlet stream of the water treatment plant proved to be effective, based on compliance with national legislation, and had no detrimental impact on overall treatment processes or final water quality. [ABSTRACT FROM AUTHOR]

Access to safe drinking water is a basic human right in South Africa. Therefore, the accurate measurement of water quality is critical in ensuring the safety of water prior to its intended use. Proficiency testing schemes (PTSs) are a recognised form of assessing the technical competence of laboratories performing these analyses. There are over 200 water testing laboratories in South Africa, with only 51 being accredited for testing some or all parameters (physical, chemical and microbiological content) prescribed in SANS 241. Only a limited number of laboratories test for organic contaminants, as this requires advanced, costly analytical instrumentation, such as GC-FID/ECD/MS and LC-UV/MS, as well as skilled staff. These laboratories are either looking at selected organic contaminants listed in the World Health Organisation (WHO) drinking water guidelines or performing the minimum requirements, as stipulated in SANS 241, for phenols, atrazine, trihalomethanes and total dissolved organic content. Whereas several local PTS providers are addressing the competent assessment of microbiological, physical and inorganic chemical testing of water, a clear need for a South African PTS provider for organic contaminant analysis in water was identified by NMISA (National Metrology Institute of South Africa) in 2012. The key drivers for the coordination of a local PTS stem mainly from the limited stability of analytes in the samples for analysis and the high cost and logistics of international PTS participation. During 2012 and 2013, NMISA conducted a PTS trial round, a workshop and 2 additional PTS rounds for organochlorine pesticides in water, for South African laboratories, and also several international participants from other countries in Africa. This paper will highlight some of the challenges faced by laboratories when analysing organochlorine pesticides at the ng/l concentration level. Issues surrounding the comparability of measurement results, traceability, method validation and measurement uncertainty are also discussed. [ABSTRACT FROM AUTHOR]

Resource-limited communities throughout the developing world face significant environmental health problems related to the myriad of coliform sources within those communities. This study comprehensively investigated contamination sources and the biological and chemical mechanisms sustaining them in two adjacent communities in rural Limpopo, South Africa. An 8-month study was conducted of household () and source water quality, measurements of biofilm layers on the inside of household water storage containers and water transfer devices, and also hand-based coliforms and hand-washing effectiveness. A 7-day water container incubation experiment was also performed to determine the biological and chemical changes that occur in a household water storage container independent of human interference. Results indicate that household drinking water frequently becomes contaminated after collection but before consumption (197 versus 1,046 colony-forming ; ; ). The most important contamination sources include biofilm layers on the inside of storage containers ( colony-forming ; ), hands ( colony-forming ; ), and coliform regrowth resulting from high assimilable organic carbon (AOC) levels during storage. A maximum specific growth rate, , of was determined for total coliform bacteria on AOC, and a high correlation between AOC concentrations and the growth potential of total coliform bacteria was observed. These results support the implementation of point-of-use water treatment and other interventions aimed at maintaining the safe water chain and preventing biological regrowth. [ABSTRACT FROM AUTHOR]

Background: In low and middle income countries, public perceptions of drinking water safety are relevant to promotion of household water treatment and to household choices over drinking water sources. However, most studies of this topic have been cross-sectional and not considered temporal variation in drinking water safety perceptions. The objective of this study is to explore trends in perceived drinking water safety in South Africa and its association with disease outbreaks, water supply and household characteristics. Methods: This repeated cross-sectional study draws on General Household Surveys from 2002-2009, a series of annual nationally representative surveys of South African households, which include a question about perceived drinking water safety. Trends in responses to this question were examined from 2002-2009 in relation to reported cholera cases. The relationship between perceived drinking water safety and organoleptic qualities of drinking water, supply characteristics, and socio-economic and demographic household characteristics was explored in 2002 and 2008 using hierarchical stepwise logistic regression. Results: The results suggest that perceived drinking water safety has remained relatively stable over time in South Africa, once the expansion of improved supplies is controlled for. A large cholera outbreak in 2000-02 had no apparent effect on public perception of drinking water safety in 2002. Perceived drinking water safety is primarily related to water taste, odour, and clarity rather than socio-economic or demographic characteristics. Conclusion: This suggests that household perceptions of drinking water safety in South Africa follow similar patterns to those observed in studies in developed countries. The stability over time in public perception of drinking water safety is particularly surprising, given the large cholera outbreak that took place at the start of this period. [ABSTRACT FROM AUTHOR]

South Africa is a country of contrasts with far ranging variations in climate, precipitation rates, cultures, demographics, housing levels, education, wealth and skills levels. These differences have an impact on water services delivery as do expectations, affordability and available resources. Although South Africa has made much progress in supplying drinking water, the same cannot be said regarding water quality throughout the country. A concerted effort is currently underway to correct this situation and as part of this drive, water safety plans (WSP) are promoted. Rand Water, the largest water services provider in South Africa, used the World Health Organization (WHO) WSP framework as a guide for the development of its own WSP which was implemented in 2003. Through the process of implementation, Rand Water found the WHO WSP to be much more than just another integrated quality system. [ABSTRACT FROM AUTHOR]

South Africa is a water constrained country with a large mining industry. Effluents from the mining industry, which is rich in calcium sulphate, resulted in salination of the limited amount of surface water. South Africa is also a large importer of sulphur because it is required for the manufacture of sulphuric acid. It is argued that importation of sulphur can be replaced by recovering it as a by-product during treatment of sulphate-rich effluents. The removal of acid, metals and sulphate from mine water was assessed using the CSIR ABC (Alkali-Barium-Calcium) Desalination process. The CSIR ABC Desalination process was used for neutralization and removal of the total dissolved solids content from 7600 to 400 mg/l. Metals were removed effectively through precipitation with CaS or Ca(HS)2. The latter compound had a high solubility with higher metal removal rates compared to CaS. Sulphate remained in solution during metals precipitation with sulphide. The rate of sulphate removal during gypsum crystallization was influenced by the gypsum seed crystal content. The rate of sulphate removal during BaCO3 treatment was influenced by pH, CaCO3 solids and BaCO3 solid concentration. Ca(HS)2 was produced from CaS by passing CO2 through a CaS slurry. Further CO2 additions resulted in H2S-stripping. BaSO4 and CaCO3 were converted simultaneously to BaS and CaO, respectively. The optimum temperature was 1050°C. The cost of raw materials for the treatment of water with a TDS content of 7 600 mg/l amounted to R2.21/cubic metre (m3). The potential value of the water and by-products amounted to R11.10/m3 (US$1.00 = ZAR7.60). [ABSTRACT FROM AUTHOR]

The concept of safe water is defined by three principles: the health-related quality must be suitable, the supply/source must be accessible and the water must constantly be available in quantities sufficient for the intended use. If any one (or more) of these three elements is missing from a water services improvement programme, providing safe water is not successfully achieved. A study in a deep rural area in South Africa showed that providing small communities, using untreated river water as their only water source, with good quality water through a piped distribution system and accessible at communal taps did not fall within our parameters of safe water. The parameters for measuring the three principles were: absence of Escherichia coli in drinking water samples; accessibility by improving tap distances to within 200 m from each household; availability by assessing whether households have at least 25 L per person per day. Results show that although E. coli levels were reduced significantly, households were still consuming water with E. coli numbers at non-compliant levels. Access (distance) was improved from an average of 750 m from households to river source to an average of 120 m to new on-tap source points. This did not result in significant increases in household quantities, which on average remained around 18 L per person per day. [ABSTRACT FROM AUTHOR]

To investigate the effect of long storage and household containers on the microbiological quality of water in a rural community, borehole water from the reservoir and seven standpipes was used. Borehole water was stored for a period of 72 h in household containers (polyethylene-PE and galvanised steel-GS), which are commonly used by the rural community of Mgquba village. Heterotrophic plate count (HPC) and faecal coliform bacteria were used as the main parameters. Standard spread plate procedure and membrane filtration method were used to enumerate HPC and faecal coliform bacteria respectively. The results of this study revealed three factors that affected the microbiological quality of drinking groundwater used by the rural community of Mgquba village: the intake water, the duration of storage and the household container. The initial levels of faecal coliform (range of faecal coliforms: 0.1–2 cfu · 100 m-1 in the reservoir water, 0–57 cfu · 100 ml-1 in the standpipe water) and HPC bacteria (average counts: 5 log cfu · ml-1 in the reservoir water, 7 log cfu · ml-1 in the standpipe water) in both reservoir and standpipe waters far exceeded the limit allowed by the South African Water Quality Guidelines for Domestic Use (no risk target water quality range: 0 count · 100 ml-1 for faecal coliforms, 0–100 counts · ml -1 for HPC bacteria). The persistence of faecal coliforms in polyethylene-stored water was observed after 72 h of storage while their complete elimination in the galvanized steel-stored water occurred after 48 h of storage. Escherichia coli was the most dominant faecal coliform found in the initial and stored waters. Although the yield of HPC bacteria increased in water samples during storage in both polyethylene and galvanised steel containers, the microbiological quality of drinking groundwater deteriorated consistently with the length of the storage. Water stored for 72 h displayed a higher yield of HPC (average counts: 7 log-8 log cfu · ml-1 in PE-stored water, 6 log-8 log cfu · ml-1 in GS-stored water) than the water stored for 48 h or 24 h (average counts: S log-8 log cfu · ml-1 in PE-stored water, 5 log-7 log cfu · ml-1 in GS-stored water). Statistical analysis indicated a significantly higher number of HPC bacteria in the water stored in polyethylene than in the water stored in galvanised steel (P=0.02). Significant differences in HPC bacteria were also noted within household container-stored water from standpipes (P=0.0001 for PE, P=0.0002 for GS). [ABSTRACT FROM AUTHOR]

Enteric infections and water-related illnesses are more frequent during times of relative water abundance, especially in regions that experience bimodal rainfall patterns. However, it is unclear how seasonal changes in water availability and drinking water source types affect enteric infections in young children. This study investigated seasonal shifts in primary drinking water source type and the effect of water source type on enteric pathogen prevalence in stool samples from 404 children below age 5 in rural communities in Limpopo Province, South Africa. From wet to dry season, 4.6% (n = 16) of households switched from a source with a higher risk of contamination to a source with lower risk, with the majority switching to municipal water during the dry season. In contrast, 2.6% (n = 9) of households switched from a source with a lower risk of contamination to a source with higher risk. 74.5% (n = 301) of the total households experienced interruptions in their water supply, regardless of source type. There were no significant differences in enteric pathogen prevalence between drinking water sources. Intermittent municipal water distribution and household water use and storage practices may have a larger impact on enteric infections than water source type. The limited differences in enteric pathogen prevalence in children by water source could also be due to other exposure pathways in addition to drinking water, for example through direct contact and food-borne transmission. [ABSTRACT FROM AUTHOR]

Efforts to provide water to developing communities in South Africa have resulted in various types of water supplies being used. This study examined the relationship between the type of water supply and the quality of water used. Source (communal taps, private outdoor and indoor taps) and point-of-use water samples were examined for heterotrophic plate counts (HPC), total and faecal coliforms, E. coli, and coliphages. Ten percent of samples were also analysed for enteric viruses, Giardia and Cryptosporidium. Approximately 320 households were included in a case-control study. In addition, a cross-sectional study was conducted. Both studies examined the relationship between different types of water facilities and diarrhoea among pre-school children. The source water was of good microbial quality, but water quality was found to have deteriorated significantly after handling and storage in both case and control households, exceeding drinking water quality guideline values by 1-6 orders of magnitude. Coliphage counts were low for all water samples tested. Enteric viruses and Cryptosporidium oocysts were not detected. Giardia cysts were detected on one occasion in case and control in-house samples. Comparisons of whether in-house water, after handling and storage, complied with water quality guideline values demonstrated households using communal taps to have significantly poorer quality than households using private outdoor or indoor taps for HPC and E. coli (χ² = 14.9, P = 0.001 χ² = 6.6, P = 0.04 respectively). A similar trend (although not statistically significant) was observed for the other microbial indicators. The cross-sectional study demonstrated an apparent decrease in health risk associated with private outdoor taps in comparison to communal taps. This study suggests that a private outdoor tap is the minimum level of water supply in order to ensure the supply of safe water to developing communities. [ABSTRACT FROM AUTHOR]

South Africa is facing population and climate-related challenges such as pressure on arable land, provision of clean and safe drinking water, and water-borne health problems. The devastating drought during 2014-2018 further amplified those problems and put additional pressure on already stressed water resources in the uMngeni River basin in the KwaZulu-Natal province. Even today, additional water is being transferred from the neighbouring basins to satisfy the needs of the rapidly increasing urban population. Understanding the impact of changing climate can lead to an increase in the region's resilience by providing direction for adaptation strategies. The uMngeni River basin supports two large urban centres, subsistence and intensive commercial agriculture, forestry, and dairy farming. Apart from the limited amount of water available in the catchment itself to support these activities, the usability of its waters is threatened by decreasing water quality, in particular nutrient enrichment and eutrophication due to the farming, old infrastructure, and improper solid waste management. A set of scientific tools (e.g. http://hypeweb.smhi.se/) helps the decision makers to understand how the water availability and nutrient loads might change in the future and to plan appropriate adaptation strategies. We present here climate impact indicators (CIIs) produced from the outputs of the HYPE model (Lindström et al., 2010) that quantify the changes in the simulated discharge and nutrients in the greater uMngeni River area projected due to climate change. We used climate data from 18 Global Climate Models (GCM's) developed at various institutions with different initial conditions (https://climate.copernicus.eu/) and emission scenarios (RCP4.5 and RCP8.5) to force the HYPE model. From these 18 GCM's, the six that adequately described the current local climate in the study area were used to quantify the CIIs. The period 2011-2100, broken into three 30-year segments was used to evaluate the impacts in the near future, mid-century, and far future as compared to the current period (1971-2000). Four out of the six models predicted deterioration in water quality, which might amplify the eutrophication problem. Eutrophication would impact human health, increase treatment costs, algal blooms; and possibly reduce agricultural land productivity. The change in total nitrogen concentrations was projected between -5 and 20% across all future periods but the percentage changes for phosphorus were generally higher than for nitrogen. The total phosphorus concentration is projected to change by -2 to 35%. The models also predicted a decrease in the water discharge of up to 40%, which would reduce drinking water availability and increase infrastructural costs. The decision makers need to identify the spatial patterns in order to implement mitigative measures like improvement of land management to reduce fertiliser demand, undertake solid waste management but also invest in water efficient technologies e.g., drip irrigation. Lindström G. et al. (2010). Development and test of the HYPE (Hydrological Predictions for the Environment) model – A water quality model for different spatial scales. Hydrology Research 41.3-4:295-319. [ABSTRACT FROM AUTHOR]