Thesis (MSc Food Sc (Food Science))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Agriculture in the Western Cape is not only one of the most important economic sectors but also provides many job opportunities. Over the last few years the sustainability of this successful industry has become threatened by the faecal pollution of rivers used to irrigate produce that will be consumed raw or after minimal processing. This situation not only poses an enormous risk to the health of the consumer but also to farmers who stand to lose their export licenses. The purpose of this study was to determine the microbial types and loads in river water, irrigation water and on irrigated produce. A baseline study was done on four sites in two Western Cape rivers. These sites were chosen to allow for the sampling of river water, irrigation water and irrigated produce so as to determine whether a link between the use of contaminated irrigation water and the microbial population found on irrigated produce exists. The physico-chemical analyses used in the study consisted of: pH, alkalinity, water temperature, conductivity and chemical oxygen demand. The microbial monitoring included the aerobic colony counts (ACC) and the enumeration of the total coliforms, faecal coliforms, staphylococci, enterococci, and aerobic and anaerobic sporeformers present in the water samples. The presence or absence of the potential pathogens like E. coli, Listeria and Salmonella, was also determined. During the baseline study faecal coliform counts as high as 160 000 organisms.100 mL-1 were noted in the Plankenburg River, while counts as high as 460 000 organisms.100 mL-1 were found in the Mosselbank River. Apart from this, high numbers of staphylococci and intestinal enterococci were often found, while E. coli, Listeria and Salmonella were present in samples from both of these rivers. Based on the results of the baseline study on the two rivers it was decided to do a more intensive study on the microbial load of the river and irrigation water as well as irrigated produce from the Mosselbank site. Lettuce and cabbages from a commercial farmer’s fields were chosen as the irrigated produce. During the warmer summer months, ACC counts in the river samples peaked at 12 8000 000 cfu.mL-1, while faecal coliform counts of 1 600 000 organisms.100 mL-1 were found. The three potential pathogens (E. coli, Listeria and Salmonella) were present in all the river samples taken during this period. While the counts of indicator bacteria in the irrigation water was often lower, faecal coliform counts as high as 1 600 000 organisms.100 mL-1 and several other potential pathogens were found on the irrigated lettuce and cabbage. This could indicate a possible “build-up” of contamination on the produce with the repeated application of the tainted irrigation water. According to guidelines published by DWAF in 2008, water to be used for irrigation should not contain more than 4 000 organisms.100 mL-1 faecal coliforms if it is used for the irrigation of crops that are to be consumed raw or after a minimal processing step, as this would increase the health risk to the consumer. Guidelines published by the South African Department of Health are even stricter and state that raw vegetables and fruit should not contain more than 200 coliform organisms per gram, while E. coli and L. monocytogenes should be absent in one gram, and Salmonella spp. in 25 grams of the produce, respectively. From the data obtained during this study it was evident that the two rivers monitored regularly contained faecal indicators at levels much higher than those proposed in national and international guidelines for safe irrigation, making them unfit for the irrigation of MPF’s. It could be concluded that the rivers investigated during this study contained high levels of faecal contamination. Since some of the pathogens isolated from the river and irrigation water and the irrigated produce, it suggests a carry-over of microbial contamination from the river water to the irrigated produce. This was, however, only done using the traditional international methods and the presence of specific pathogens should in future be confirmed by means of molecular techniques. / AFRIKAANSE OPSOMMING: Landbou is nie net die een van die belangrikste ekonomiese sektore in die Wes-Kaap nie, maar verskaf ook vele werksgeleenthede. Oor die afgelope paar jaar word die volhoubaarheid van hierdie suksesvolle industrie egter bedreig deur die fekale kontaminasie van riviere wat gebruik word vir die besproeiing van voedsel wat rou of na ‘n minimale prosesserings stap ingeneem word. Hierdie situasie hou nie net ‘n groot gevaar vir die gesondheid van verbruikers in nie, maar ook vir boere wat hul uitvoerlisensies hierdeur kan verloor. Die doel van hierdie studie was om die ladings en tipes mikrobes in rivier water, besproeiingswater en op besproeide produkte vas te stel. ‘n Basiese studie van vier liggings in twee Wes-Kaapse riviere is gedoen. Hierdie liggings is só gekies dat dit moontlik was om die rivier water, besproeiingswater en die besproeide produkte te monitor, en daar sodoende vasgestel kon word of daar ‘n verhouding is tussen die gebruik van gekontamineerde besproeiingswater en die mikrobe populasie wat op die besproeide produkte aanwesig was. Die fisiko-chemiese analises wat gedurende die studie gedoen is, het pH, alkaliniteit, water temperatuur, geleidingsvermoë en die chemiese suurstof vereiste (COD) ingesluit. Die mikrobiese analises het die aërobe kolonie tellings (ACC) en die enumerasie van die totale kolivorme, fekale kolivorme, staphylococci, enterococci en die aërobe en anaërobe spoorvormers ingesluit. Daar is ook vir die aanwesigheid van potensiële patogene soos E. coli, Listeria en Salmonella getoets. Gedurende die basiese studie is fekale kolovorme tellings van so hoog as 160 000 organismes.100mL-1 in die Plankenburg Rivier aangeteken, terwyl tellings van so hoog as 460 000 organismes.100mL-1 in die Mosselbank Rivier gevind is. Hoë tellings stafielokokki en intestinale enterokokki is gereeld genoteer, terwyl E.coli, Listeria en Salmonella uit die waters van beide hierdie riviere geïsoleer is. Gebaseer op hierdie resultate is daar besluit om ‘n meer intensiewe studie van die rivier, besproeiingswater en die besproeide produkte van die Mosselbank Rivier te doen. Blaarslaai en kool van ‘n kommersiële boer se lande is vir hierdie doel gekies. Gedurende die warmer somer maande het die aërobe kolonie tellings in die rivier ‘n piek van 12 800 000 kve.mL-1 bereik, terwyl fekale kolivorme tellings van 1 600 000 organismes.100mL-1 genoteer is. Die drie potensiële patogene (E. coli, Listeria en Salmonella) was aanwesig in al die monsters wat gedurende hierdie tydperk van die rivierwater geneem is. Alhoewel die tellings indikator bakterieë in die besproeiingswater meestal laag was, is tellings fekale kolivorme van so hoog as 1 600 000 kve.100mL-1 en verskeie ander potensiële patogene op die besproeide blaarslaai en kool gevind. Dit kan dui op ‘n moontlike opbou van kontaminasie op die produkte met die herhaalde besproeiing met gekontamineerde besproeiingswater. Volgens die riglyne wat in 2008 deur DWAF gepubliseer is, mag water wat vir die besproeiing van minimaal geprosesseerdevoedsels gebruik word nie meer as 4 000 organismes.100mL-1 bevat nie, aangesien dit die gesondheid van die gebruiker in gevaar mag stel. Die riglyne van die Suid-Afrikaanse Departement van Gesondheid is selfs strenger en beveel aan dat rou vrugte en groente nie meer as 200 kolivorme en geen L. monocytogenes per gram, en geen Salmonella spp. in 25 g van die produk mag bevat nie. Vanuit die data wat tydens hierdie studie ingesamel is, is dit duidelik dat die twee riviere gereeld fekale indikators bevat het teen vlakke baie hoër as wat in die nasionale en internasionale riglyne aanbeveel word. Hierdie water is dus nie geskik vir die besproeiing van minimaal geprosesseerde produkte nie. Die afleiding kan gemaak word dat die riviere wat tydens hierdie studie gemonitor is, hoë vlakke van fekale kontaminasie bevat het. Aangesien sommige van die patogene vanuit beide die rivier- en besproeiingswater, en vanaf die besproeide produkte geïsoleer is, kan dit dui op ‘n moontlike oordrag van mikrobiese kontaminasie vanuit die rivierwater na die besproeide produkte. Tydens hierdie studie is daar egter net van die tradisionele internasionale metodes gebruik gemaak. Vir toekomstige navorsing word dit aanbeveel dat die aanwesigheid van die spesifieke patogene deur die gebruik van molekulêre metodes bevestig word.

A growing human population accompanied by urbanisation and industrialisation have led to over exploitation and pollution of freshwater resources and have consequently impacted on aquatic ecosystem health. The Swartkops River in the Eastern Cape of South Africa is no exception. It drains a heavily industrialised catchment which has led to deterioration of its water quality due to pollution. Integrated water resources management (IWRM) requires the concurrent sustainable use of water resources and the protection of aquatic ecosystem health. Macroinvertebrates are well known for their ability to reflect the health of the environment in which they live, thus they were used to assess anthropogenic impacts in the Swartkops River for this study. Macroinvertebrate based biomonitoring approaches, including the South African Scoring System version 5 (SASS5); a multimetric approach involving 19 metrics; Chironomidae community assessments and screening of morphological deformities in Chironomidae larvae, were applied at four selected sampling sites to assess environmental water quality in the Swartkops River. Macroinvertebrates were sampled us ing the SASS5 protocols. Chironomidae were mounted and identified as far as practically possible using available keys. Mentum, ligula, mandible, paraligula and antenna in Chironomidae larvae were screened for deformities. Physical and chemical water quality variables were measured at each of the selected sampling sites. All data were subjected to relevant statistical analyses. Of the four sites sampled during the study period, results revealed that water quality at site 1 was the least impacted with highest SASS5 scores, average score per taxa (ASPT) values, richness, diversity, equitability and Ephemeroptera –Plecoptera-Trichoptera (EPT) richness, as well as least incidences of chironomid deformities. Water quality at site 2 was considered the next least impacted with higher SASS5 scores, A SPT values, richness, diversity and equitability, and lower incidences of deformities compared to sites 3 and 4. SASS5 scores and ASPT values revealed that both sites 3 and 4 were critically modified but the multimetric analysis, Chironomidae community assessment and incidences of deformities in Chironomidae larvae indicated that site 3 is the most impacted of the four sampling sites, with least species diversity, richness, equitability and highest incidences of deformities. The study revealed the importance of multicriteria approach to environmental biomonitoring as an integrated water resources management tool, and based on the results, site 3, as the most impacted, could be prioritised for restoration intervention.

This study assesses the presence of selected trace metals and pops in the Baynespruit River, Sobantu, KwaZulu-Natal. Sediments, plants and water samples were collected along the river during dry and wet season. For metal analysis, the extraction was done using acid digestion and then determined on the inductively coupled plasma atomic emission spectroscopy, for total metals in sediments, plants and water. Bio-available metals in sediments were analysed using atomic absorption spectroscopy. POPs were extracted in sediments using soxhlet extraction, which was followed up by evaporation on the rotary evaporator, sample clean up on a GPC column, further sample concentration on the rotary evaporator and later analysed on GC/MS instrument. Metals of concern in both seasons were Cu, Cr, Pb and Zn which exceeded maximum permissible limits for South African soil, Cr was just about the maximum permissible limit. The targeted POPs were not detected on any site during this work. / Environmental Sciences / M. Sc. (Environmental Science)

Surface water pollution is prevalent in numerous areas of central Roodepoort mainly due to gold mining activities. The surface water quality for the Bosmontspruit, Russell’s Stream and the New Canada Dam was assessed from October 2010 to March 2011. Physical, chemical and biological characteristics of the water were determined for 8 monitoring points and the results obtained were compared with the In-stream water quality guidelines for the Klip River catchment and the South African Water Quality Guidelines. A trend noticed throughout the sampling period was the non-compliance in the levels of total dissolved solids (TDS) and dissolved oxygen. The results indicated that concentrations of iron, aluminium, nickel, manganese and potassium were above the limit across the Bosmontspruit and Russell’s stream. There was also significant evidence of excessive faecal coliform and ammonium pollution in the Bosmontspruit. During the monitoring period it was noted that water from these streams were utilised for crop irrigation, bathing, livestock and human consumption and may pose a health hazard due to poor water quality. / Environmental Sciences / M.Sc. (Environmental Science)

Car washing consumes large quantities of water and results in large amounts of wastewater effluent being generated, but has received little attention as a potential source of water pollution globally. The study investigated the water use, wastewater effluent quality and toxicity of selected carwashes in City of Tshwane. Ten carwashes in the City of Tshwane were purposively selected and analysis done on a variety of water quality aspects including microbiological, toxicity, BOD,COD, oil and grease, anionic surfactants, sulphates, phosphates and heavy metals. The results obtained show that oil and grease exceeded the WHO and National Water Act standards of 2.5mg/L in all sites except CW2 and Diesel range organics were significantly high in some sites (CW4, 7 & 8) at 60.5, 40 and 48.8mg/L. COD and BOD of the waste water exceeded the WHO standards of 30mg/L and 60mg/L in all sites except CW2. Bacteria contamination was very high in all wastewater samples and all samples exhibited (mild to high) toxicity to Vibrio fischeri and high toxicity to Daphnia pulex except CW2. These results suggest that wastewater from carwashes is high in some pollutants that may interfere with the receiving environment and municipal treatment systems and there is a need for responsible authorities to regulate the quality of effluent discharged into the environment / Environmental Sciences / M.Sc. (Environmental Science)

Ph.D. / The Crocodile River catchment, in Mpumalanga, is one the most intensively used catchments in South Africa. The large number of intensively cultivated crops grown in the middle and lower subcatchments; industrial discharges; highly intensive irrigation; and extensive areas of exotic afforestation in the upper and middle sub-catchments has dramatically changed land use patterns within the catchment. The Middle Crocodile River sub-catchment is also impacted by intensive urbanisation; around Nelspruit, KaNyamazane and Matsulu. The Kaap River sub-catchment has been intensively mined for minerals and the impacts of these mining operations are still reflected in the water quality of streams and rivers in this sub-catchment. The downstream uses of the Crocodile River's water quality are the aquatic ecosystem, the Kruger National Park (as the river is the southern boundary of the park) and Mozambique (international obligations). The Crocodile River catchment supports one of the richest fish species diversities in South Africa. It is therefore important to determine the impacts of these land use activities on the fish populations and the potential human health risks if fish are consumed. In the present study data from five gauging stations for each of the main tributaries draining the five sub-catchments (the Upper, Middle and Lower Crocodile River, Kaap and Elands Rivers) were used. The water quality and quantity was determined from Department of Water Affairs and Forestry's (DWAF) National Hydrological Chemical Data Bank. Assessments of water quality (chemical, physical), sediment characteristics, and fish biological characteristics were undertaken at each of the chosen sampling sites. Water and fish samples were collected seasonally on ten sampling trips during the study period, June 1989 to September 1992. Eleven species of fish were collected, by means of gill and seine nets, at eight sites. The biological characteristics of the larger fish captured were measured and tissue (gills, liver, muscle, intestine, ovaries, testes and abdominal fat) samples were collected. These samples were analysed for eleven metals and Pyrethroid, Carbamate, Organochlorine, Organophosphate and Triazine pesticides. Sediment core samples were collected and determinations made of particle size, percentage organics, metals and pesticides. Standard methods were used for the determination of .the metal and pesticide concentrations in the water, sediment and fish tissues. The pesticide use per crop for South Africa was determined from a data-base. This data was used to determine the potential pesticide runoff from the different crops in the sub-catchments and to compare with the sediment and fish tissue levels recorded. The water quality status of the Crocodile River catchment is impacted by a variety of diffuse and point sources of pollution. The water quality indicated that diffuse sources of pollution originated from afforestation in the Upper, Middle and Kaap River sub-catchments; current and abandoned mining activities in the Kaap River sub-catchment; runoff from irrigated lands in the Middle, Lower and Kaap River sub-catchments; and wastes from industrial activities in the Elands and Middle sub-catchments. Point sources of pollution in the Crocodile River include ndustrial and waste water treatment works discharges mainly in the Middle sub-catchment.

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

Vibrio infections remain a serious threat to public health. In the last decade, Vibrio disease outbreaks have created a painful awareness of the personal, economic, societal, and public health costs associated with the impact of contaminated water in the aquatic milieu. This study was therefore designed to assess the prevalence of Vibrio pathogens in the final effluents of wastewater treatment plants (WWTPs) in the Eastern Cape Province, as well as their abilities to survive the treatment processes of the activated sludge system either as free cells or as plankton-associated entities in relation to the physicochemical qualities of the effluents. Three wastewater treatment facilities were selected to represent typical urban, sub-urban and rural communities, and samples were collected monthly from August 2007 to July 2008 from the final effluent, discharge point, 500 meter upstream and downstream of the discharge points and analysed for physicochemical parameters, Vibrio pathogens prevalence and their antibiogram characteristics using both culture based and molecular techniques. Physicochemical parameters measured include pH, temperature, electrical conductivity, salinity, turbidity, total dissolved solid (TDS), dissolved oxygen (DO), chemical oxygen demand (COD), nitrate, nitrite and orthophosphate levels. Unacceptably high levels of the assayed parameters were observed in many cases for COD (<10 - 1180 mg/l), nitrate (0.08 - 13.14 mg NO3- as N/l), nitrite (0.06 - 6.78 mg NO2- as N/l), orthophosphate (0.07-4.81 mg PO43- as P/l), DO (1.24 - 11.22 mg/l) and turbidity (2.04 -159.06 NTU). Temperature, COD and nitrite varied significantly with season (P < 0.05), while pH, EC, salinity, TDS, COD, and nitrate all varied significantly with sampling site (P < 0.01; P < 0.05). In the rural wastewater treatment facility, free-living Vibrio densities varied from 0 to 3.45 × 101 cfu ml-1, while the plankton-associated Vibrio densities vary with plankton sizes as follows: 180 μm (0 – 4.50 × 103 cfu ml-1); 60 μm (0 – 4.86 × 103 cfu ml-1); 20 μm (0 – 1.9 × 105 cfu ml-1). The seasonal variations in the Vibrio densities in the 180 and 60 μm plankton size samples were significant (P < 0.05), while the 20 μm plankton size and free-living vibrios densities were not. Molecular confirmation of the presumptive vibrios isolates revealed V. fluvialis (36.5 percent), as the predominant species, followed by V. vulnificus (34.6 percent), and V. parahaemolyticus (23.1 percent), and V. metschnikovii (5.8 percent) (detected using only API 20 NE), suggesting high incidence of pathogenic Vibrio species in the final effluent of the wastewater facility. Correlation analysis suggested that the concentration of Vibrio species correlated negatively with salinity and temperature (P < 0.001 and P < 0.002 respectively) as well as with pH and turbidity (P < 0.001), in the final effluent. Population density of total Vibrio ranged from 2.1 × 101 to 4.36 × 104 cfu ml-1 and from 2.80 ×101 to 1.80 × 105 cfu ml-1 for the sub-urban and urban communities treatment facilities respectively. Vibrio species associated with 180 μm, 60 μm, and 20 μm plankton sizes, were observed at densities of 0 - 1.36 × 103 cfu ml-1, 0 - 8.40 × 102 cfu ml-1 and 0 - 6.80 × 102 cfu ml-1 respectively at the sub-urban community‘s WWTP. In the urban community, counts of culturable vibrios ranged from 0 - 2.80 × 102 cfu ml-1 (180 μm); 0 - 6.60 × 102 cfu ml-1 (60 μm) and 0 -1.80 × 103 cfu ml-1 (20 μm). Abundance of free-living Vibrio species varied between 0 and the orders of 102 and 103 cfu ml-1 in the sub-urban and urban communities WWTPs respectively. Molecular confirmation of the presumptive vibrios isolates revealed the presence of V. fluvialis (41.38 percent), V. vulnificus (34.48 percent), and V. parahaemolyticus (24.14 percent) in the sub-urban community effluents. In the urban community V. fluvialis (40 percent), V. vulnificus (36 percent), and V. parahaemolyticus (24 percent) were detected. There was no significant correlation between Vibrio abundance and season, either as free-living or plankton-associated entities, while Vibrio species abundance correlated positively with temperature (r = 0.565; P < 0.01), salinity and dissolved oxygen (P < 0.05). Turbidity and pH showed significant seasonal variation (P < 0.05) in both locations. The Vibrio strains showed the typical multi-antibiotic-resistance of an SXT element. They were resistant to sulfamethoxazole (Sul), trimethoprim (Tmp), cotrimoxazole (Cot), chloramphenicol (Chl) and streptomycin (Str), as well as other antibiotics such as ampicillin (Amp), penicillin (Pen), erythromycin (Ery), tetracycline (Tet), nalidixic acid (Nal), and gentamicin (Gen). The antibiotic resistance genes detected includes dfr18 and dfrA1 for trimethoprim; tetA, strB, floR, sul2 blaP1, for tetracycline, streptomycin, chloramphenicol, sulfamethoxazole and β-lactams respectively. A number of these genes were only recently described from clinical isolates, demonstrating genetic exchange between clinical and environmental Vibrio species. This study revealed that there was an adverse impact on the physicochemical characteristics of the receiving watershed as a result of the discharge of inadequately treated effluents from the wastewater treatment facilities. The occurrence of Vibrio species as plankton-associated entities confirms the role of plankton as potential reservoir for this pathogen. Also the treated final effluents are reservoirs of various antibiotics resistance genes. This could pose significant health and environmental risk to the biotic component of the environment including communities that rely on the receiving water for domestic purposes and may also affect the health status of the aquatic milieu in the receiving water. There is need for consistent monitoring programme by appropriate regulatory agencies to ensure compliance of the wastewater treatment facilities to regulatory effluent quality standards.

Wastewater discharges may contain health compromising pathogens and carcinogenic and/or chemical substances that could compromise the public health and impact negatively on the environment. The present study was conducted between August 2007 and July 2008 to evaluate the Listeria abundance (as free-living and plankton associated species) and physicochemical qualities of the final effluents of three wastewater treatment facilities in the Eastern Cape Province of South Africa selected to represent typical urban, peri-urban and rural communities and the impact of the discharged final effluents on their respective receiving watershed, as well as to elucidated the in vitro antibiotic susceptibilities and resistance genes profile of Listeria species isolated from the final effluents. The suitability of the secondary effluent of the urban treatment facility (as a case study) for use in agriculture and aquaculture with reference to recommended standards was also determined. Wastewater samples were collected from the raw sewage, secondary effluent, final treated effluent, discharge point, 500 m upstream discharge point, and 500 m downstream discharge point from all three locations on a monthly basis throughout the study period. Listeria abundance in the final effluents and the receiving watersheds varied between 2.9× 100 and 3.52 × 105cfu/ml across the sampled locations. Free-living listerial density across the sampled locations ranged between 0 and 3.2 × 103cfu/ml while counts of Listeria species attached to large (180 μm) planktons varied from 0 to 1.58 × 105 cfu/ml and those of the 60 and 20 μm categories were in the range of 0 to 1.32 × 103 cfu/ml and 0 to 2.82 × 105 cfu/ml respectively. Listeria abundance did not vary significantly with location and season; there was however, significant (P < 0.05; P < 0.01) variance in Listeria abundance with plankton sizes across the locations. Free-living Listeria species were more abundant in the rural and urban xii communities than plankton attached Listeria species; whereas the reverse was the case in the peri-urban community. Prevalence of Listeria in terms of total counts was 100 percent across all sampled locations. Free-living Listeria species showed prevalence ranging from 84-96 percent across the sampling locations; while Listeria species attached to large (180 μm) planktons exhibited prevalence ranging from 75 percent to 90 percent. The prevalence of medium-sized (60 μm) plankton associated Listeria species varied between 58 percent and 92.5 percent; whereas those of Listeria species attached to small (20 μm) planktons ranged from 65-100 percent across all three communities. Listeria prevalence was generally a reflection of the turbidity of the water system, with free-living Listeria species being more prevalent than plankton associated cells in the relatively less turbid rural and urban waters compared to the more turbid peri-urban waters where plankton attached cells were more prevalent in comparison with their free living counterparts The final treated effluent quality fell short of recommended standards for turbidity, chemical oxygen demand and phosphate across all three communities. In addition, the final effluent of the rural treatment plant also fell short of recommended standard for NO3, while that of the urban treatment plant did not comply with acceptable limits for dissolved oxygen and nitrite. Other physicochemical parameters were compliant with set standards after treatment. An inverse relationship was observed between chlorine residual and listerial density across the sampled facilities; the effect of chlorine was however not enough to eliminate the pathogen from the water systems. At the urban treatment plant and its receiving watershed, pH, temperature, EC, turbidity, TDS, DO, and nitrate varied significantly with season and sampling point (P < 0.05; P < 0.01). Salinity also varied significantly with sampling point (P < 0.01), while COD and nitrite varied significantly with season (P < 0.05). Although, the treated effluent fell within recommended water quality standard for pH, TDS, nitrate and nitrite, it fell short of stipulated standards for other parameters. Whereas the microbial quality of the secondary treated effluent at this (urban) facility fell short of recommended standard after secondary treatment, its physicochemical quality were generally compliant with recommended standards for reuse wastewater in agriculture and aquaculture. Listeria pathogens isolated from effluents of the rural wastewater facility were sensitive to 11 (55 percent) of the 20 test antibiotics, and showed varying (7-71 percent) levels of resistance to 8 antibiotics; whereas those isolated from the peri-urban community showed sensitivity to 6 (30 percent) of the 20 test antibiotics, and varying (6-94 percent) levels of resistance to 12 antibiotics; while the urban effluent isolates were sensitive to 3 (15 percent) of the 20 test antibiotics, and showed varying (4.5-91 percent) levels of resistance to 17 antibiotics. Multiple antibiotic resistances involving 78.5-100 percent of isolates and antibiotics combination ranging from 2-10 antibiotics was observed across the sampled locations. Penicillin G and ampicillin showed remarkably high (64-91 percent) phenotypic resistance across the three sampled facilities. Other antibiotics, to which isolates showed significant resistance, were linezolid (22-88 percent); erythromycin (43-94 percent) and sulphamethoxazole (7-94 percent). Two of the 14 Listeria strains isolated from the rural effluents were positive for ereA and sul1 antibiotic resistance genes; while sulII genes were detected in five of the 23 Listeria isolates from the urban effluent and none was detected in isolates from the peri-urban community. The presence of antimicrobial resistance genes in the isolates did not correlate with phenotypic antibiotic resistance. The current study demonstrated that Listeria pathogens easily survived the activated sludge treatment process as free-living and plankton attached entities and suggests that municipal wastewater treatment plants are a significant source of multiple resistant Listeria pathogens in the South African aquatic milieu. While the physicochemical quality of the urban final effluent suggests that it is a major source of pollution to the receiving watershed, the secondary effluent quality demonstrated a great potential for use in agriculture and aquaculture.

Chemical (gaseous) emissions from wastewater treatment plants (WWTP) are perceived as odour and can generate undesirable health reactions. These could affect the quality of life to those regularly albeit intermittently exposed, although regular exposure may result in tolerance and loss of recognition of the odour. Consequently, research is necessary to establish the role of Environmental Impact Assessment (EIA) in ensuring that facilities such as WWTP do not pose a threat to local communities, particularly in relation to housing developments for poor communities. The aim of this study was to investigate if the EIA regulations were effectively implemented before building of the Residential Development Proiect (RDP) houses at KwaMathukuza, in Newcastle South Africa. Furthermore, the study intended to determine the impact the (WWTP) has on the health of people who reside close to the site and to establish if the families staying close to the WWTP have any common ailments such as handicapped babies, early deaths within families. Findings would also indicate if RDP houses should be built in close proximity to such sites. Data was collected through a survey of 85 residents living within five kilometers and ten residing beyond five kilometers from the WWTP. The participants were selected randomly. Municipality employees who worked with the WWTP were also sampled together with healthcare givers. Data included information about health of the community, their perception of the gases released from the WWTP as well as EIA meetings and processes related to the construction of the RDP houses. The outcome of this study revealed that EIA regulations were not adequately implemented and that this residential site was unsuitable for the construction of RDP houses. It emerged that the residence regularly experience unpleasant odours released from the WWTP. These could be associated with ill-health of the residents as well as v degradation the environment in general. The study also found that the effect of the WWTP affects even those communities who reside beyond five kilometers from the WWTP. The researcher argues for more stringent mechanisms to ensure that EIA regulations are properly implemented to prevent adverse effects on the communities. / Environmental Sciences / M. Sc. (Environmental Management)