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How to cite this thesis

Surname, Initial(s). (2012). Title of the thesis or dissertation (Doctoral Thesis / Master’s Dissertation). Johannesburg: University of Johannesburg. Available from: http://hdl.handle.net/102000/0002 (Accessed: 22 August 2017).

ASSESSMENT OF WATER AND SEDIMENT QUALITY IN THE KAALSPRUIT RIVER (SOUTH AFRICA) USING PHYSICO-CHEMICAL AND BIOLOGICAL MONITORING TECHNIQUES.

Submitted By

MALEBO SALOME MOROLE

Minor Dissertation submitted in partial fulfilment of the requirements for the degree

MAGISTER SCIENTAE

ENVIRONMENTAL MANAGEMENT

in the

FACULTY OF SCIENCE

at the

UNIVERSITY OF JOHANNESBURG

Supervisor: Dr. L. S. Modley

Co-Supervisor: Prof. I. T. Rampedi

Co-Supervisor: Prof. S. A. Bufo TABLE OF CONTENTS

Table of contents i

List of Figures iv

List of Tables vi

List of abbreviations viii

List of appendices ix

Acknowledgements x

Abstract xi

CHAPTER 1: INTRODUCTION

1.1. Background to the study 1 1.2. Problem statement and justification for the study 2 1.3. Aims and objectives of the study 4 1.4. Structure of the report 4 CHAPTER 2: LITERATURE REVIEW

2.1. Introduction 5 2.2. Water quality 6 2.2.1. Water pollution 6 a) Point sources 7 b) Non-point sources 7 2.2.2. Water quality status in South Africa 7 2.2.3. Water resources governance in South Africa 9 2.2.4. Water quality management plan 12 2.2.5. National water quality monitoring programmes 15 2.3. Water quality monitoring 16 2.3.1. The rationale for monitoring water resources 18 2.3.2. Water quality monitoring parameters 19 a) In-situ physico-chemical water quality parameters 20 b) Nutrients and biological components 23 c) Organic compounds 26 2.3.3. Biological monitoring 28 2.4. Water quality management 32 2.4.1. Integrated Water Resource Management 33 2.4.2. Community Based Water Resource Management (CBWRM) in IWRM 34 i

CHAPTER 3: STUDY AREA AND METHODOLOGY

3.1. Description of the study area 38 3.1.1. Climate 39 3.1.2. Geology and topography 40 3.1.3. Vegetation and land use 40 3.1.4. Population and settlement pattern 41 3.2. Methodology 42 3.2.1. Field survey and site location 42 3.2.2. Water quality analysis 43 3.2.3. Sediment assessment 46 3.2.4. Macroinvertebrate assessment 48 3.2.5. Habitat assessment 50 CHAPTER 4: RESULTS AND ANALYSIS

4.1. River site description 51 4.2. Water quality results 57 4.2.1. Physico-chemical analyses of water 57 4.2.2. Nutrients and microbial analysis 59 4.2.3. Metal analysis 61 4.2.4. Organic compounds analysis 63 4.3. Sediment characteristics 64 4.3.1. Moisture and organic content 64 4.3.2. Grain sizes 66 4.3.3. Metals in sediment 68 4.3.4. Organic compounds in sediment 72 4.4. Aquatic macroinvertebrate assessment 77 4.5. Habitat assessment 82 CHAPTER 5: DISCUSSION OF RESULTS

5.1. Water quality 84 5.1.1. In-situ physico-chemical water parameters 84 5.1.2. Nutrients and biological aspects 87 5.1.3. Metals in water 90 5.1.4. Organic compounds in water 92 5.2. Sediment characteristics 94 5.2.1. Physical characteristics of sediment 94 5.2.2. Metals in sediment 95

5.2.3. Organic compounds in sediment 97 5.3. Aquatic macroinvertebrates 100 5.4. Habitat assessment 102 CHAPTER 6: CONCLUSIONS AND RECOMMENDATIONS

6.1. Conclusion 105 6.2. Recommendations for a management plan 107 6.3. Recommendations for further studies in the Kaalspruit. 113 References 114

Appendices 128

iii

LIST OF FIGURES

Pg. no

Figure 2.1: Water Management Areas of South Africa. 11

Figure 2.2: Community-based water resource management framework. 14

Figure 2.3: The 12 Themes (outer circles) are integrated to inform the 4 Strategic 15 Goals of the Water Plan. Figure 2.4: Water monitoring cycle. 17

Figure 2.5: Three pillars concept for Integrated Water Resources Management by 34 Global Water Partnership.

Figure 3.1: Locality map of the Kaalspruit and the surrounding townships/suburbs. 38

Figure 3.2: Map showing the location of the Kaalspruit and Olifantspruit and the 39 surrounding land cover within the study area.

Figure 3.3: Map showing the study area and selected sampling points, and the 43 location of the study area in the context of Gauteng Province in South Africa.

Figure 3.4: Biological bands for SASS classification in the Upper Highlands. 49

Figure 4.1: Stream conditions at sampling site 1 of the Kaalspruit (Tembisa). 51

Figure 4.2: Stream conditions at sampling site 2 of the Kaalspruit (Ivory Park, 52 Freedom Drive).

Figure 4.3: Stream conditions and activities at sampling site 3 of the Kaalspruit 53 (Ivory Park, Riverside Street).

Figure 4.4: Stream conditions and riverbank activities at sampling site 4 of the 54 Kaalspruit (Clayville).

Figure 4.5: Stream conditions and riverbank activities at sampling site 5 of the 55 Olifantspruit (Olifantsfontein).

Figure 4.6: Grain size distribution of the Kaalspruit sediment during wet season 67 sampling (September 2018).

Figure 4.7: Grain size distribution of the Kaalspruit sediment during dry season 68 sampling (June 2019).

Figure 4.8: ASPT as a function of SASS score plotted within biological bands for 79 Kaalspruit (which falls within the Upper Highveld ecological zone) during wet season sampling (September 2018).

Figure 4.9: ASPT as a function of SASS score plotted within biological bands for 81 Kaalspruit (which falls within the Upper Highveld ecological zone) during dry season sampling (June 2019).

LIST OF TABLES

Pg. no

Table 2.1: Monitoring programmes in South Africa. 16

Table 3.1: Coordinates of the selected sampling points and the respective locations. 42

Table 3.2: In-situ water quality parameters measure in the field for all sampling sites. 44

Table 3.3: Water quality parameters measured in the lab for the respective sampling 44 sites.

Table 3.4: Classification of trophic status for aquatic ecosystems. 45

Table 3.5: Target Water Quality Guideline (TWQG) values with chronic (CEV) and 45 acute effect values (AEV).

Table 3.6: Reference criteria for Ideal, Tolerable, and Intolerable values for major 46 ions.

Table 3.7: Organic compounds measured in sediment samples for respective 47 sampling sites.

Table 3.8: Grain size categories (Cyrus et al., 2000). 47

Table 3.9: Reference criteria showing category ranges for chemical constituents in 48 sediment according to the Canadian Environmental Quality Guidelines for sediment.

Table 3.10: Ecological categories for SASS5 classification. 49

Table 3.11: IHAS classes as indicated by scores and description. 50

Table 4.1: Sampling sites description as assessed on the Kaalspruit. 56

Table 4.2: In-situ water quality parameters measured for the Kaalspruit during the 58 wet season (September 2018).

Table 4.3: In-situ water quality parameters measured for the Kaalspruit during the dry 58 season (June 2019).

Table 4.4: Nutrients and microbial organisms measured for the Kaalspruit during the 60 wet season sampling (September 2018).

Table 4.5: Nutrients and microbial organisms measured for the Kaalspruit during the 60 dry season sampling (June 2019).

Table 4.6: Metals measured in the Kaalspruit water during wet season sampling 62 (September 2018).

Table 4.7: Metals measured in the Kaalspruit water during dry season sampling 63 (June 2019).

Table 4.8: Percentage moisture content for the Kaalspruit sediment during wet 65 season sampling (September 2018) and dry season sampling (June 2019).

Table 4.9: Categories of sediment organic content (USEPA, 1991). 65

Table 4.10: Percentage organic content for the Kaalspruit during wet season 66 sampling (September 2018) and dry season sampling (June 2019).

Table 4.11: Chemical variables determined in sediment for the Kaalspruit during wet 70 season sampling (September 2018).

Table 4.12: Chemical variables determined in sediment for the Kaalspruit during dry 71 season sampling (June 2019).

Table 4.13: Organochlorine pesticides determined in sediment for the Kaalspruit 73 during wet season sampling (September 2018).

Table 4.14: Organochlorine pesticides determined in sediment for the Kaalspruit 73 during dry season sampling (June 2019).

Table 4.15: Semi-volatile organic compounds determined in sediment for the 74 Kaalspruit during wet season sampling (September 2018).

Table 4.16: Semi-volatile organic compounds determined in sediment for the 75 Kaalspruit during dry season sampling (June 2019).

Table 4.17: Phenolic compounds determined in sediment for the Kaalspruit during 76 wet season sampling (September 2018).

Table 4.18: SASS5 results for the Kaalspruit during wet season sampling 78 (September 2018).

Table 4.19: SASS5 results for the Kaalspruit during dry season sampling (June 80 2019).

Table 4.20: Integrated Habitat Assessment System (IHAS) results for the Kaalspruit 82 during wet season sampling (September 2018).

Table 4.21: Integrated Habitat Assessment System (IHAS) results for the Kaalspruit 83 during dry season sampling (June 2019).

vii

LIST OF ABBREVIATIONS

AEV: Acute Effect Value

ASPT: Average Score Per Taxa

CBWRM: Community-based Water Resource Management

CEV: Chronic Effect Value

CMA: Catchment Management Agency

CMS: Catchment Management Strategy

DDT: Dichlorodiphenyl Trichloroethane

DO: Dissolved Oxygen

EC: Electrical Conductivity

IHAS: Integrated Habitat Assessment System

ISO: International organisation for Standardization

ISQG: Interim Sediment Quality Guidelines

IWRM: Integrated Water Resources Management

NAEHMP: National Aquatic Ecosystem Health Monitoring Programme

NWMP: National Wetlands Monitoring Programme

NWRS: National Water Resource Strategy

OCPs: Organochlorine Pesticides

PAHs: Polycyclic Aromatic Hydrocarbons

PCBs: Polychlorinated biphenyls

PEL: Probable Effect Level

REMP: River Ecosystem Monitoring Programme

SASS5: South African Scoring System-version 5

SEMA: Specific Environmental Management Act

SVOCs: Semi-volatile organic compounds

TDS: Total Dissolved Solids

TWQR: Target Water Quality Range

WMA: Water Management Areas

viii

LIST OF APPENDICES

Pg. no

Appendix 1: Metals measured in the Kaalspruit water during wet season sampling 128 (September 2018). Values compared with the DWAF guidelines (1996).

Appendix 2: Metals measured in the Kaalspruit water during dry season sampling 130 (June 2019). Values compared with the DWAF guidelines (1996).

Appendix 3: Organochlorine pesticides measured in the Kaalspruit water for the wet 131 season sampling (September 2018).

Appendix 4: Organochlorine pesticides measured in the Kaalspruit water for the dry 131 season sampling (June 2019).

Appendix 5: Values for Polychlorinated Biphenyls (PCBs) determined from the wet 132 season sampling (September 2018).

Appendix 6: Values for Polychlorinated Biphenyls (PCBs) determined from the dry 133 season sampling (June 2019).

Appendix 7: Semi-volatile organic compounds measured in the Kaalspruit water for 134 the wet season sampling (September 2018).

Appendix 8: Semi-volatile organic compounds measured in the Kaalspruit water for 135 the dry season sampling (June 2019).

Appendix 9: Phenolic compounds measured in the Kaalspruit water for the wet 136 season sampling (September 2019).

Appendix 10: Phenolic compounds measured in the Kaalspruit water for the dry 136 season sampling (June 2019).

ACKNOWLEDGEMENTS

I would like to extend my gratitude to the following people who had a crucial role to play in the completion of my study:

• My supervisor Dr. L. S. Modley, thank you for your time, patience, support, valuable guidance and contribution throughout my study. • My Co-supervisors Prof. I. T. Rampedi and Prof. S. A. Bufo for the contribution and constructive feedback throughout my study. • The university of Johannesburg and NRF and Thuthuka for providing financial support. • The ecotoxicology laboratory at the University of Johannesburg for use of their equipment. • My friends and family for their continuous support, understanding, and all the words of encouragement throughout my study.

ABSTRACT

The Kaalspruit is situated in the Gauteng Province of South Africa and runs through the townships of Tembisa and Ivory Park including the suburbs and industrial areas of Clayville and Olifantsfontein, which are under the Ekurhuleni Metropolitan Municipality and City of Tshwane Metropolitan Municipality. The river forms a confluence with the Olifantspruit towards the north which flows further northward and into the Hennops River. The Kaalspruit has been plagued with water quality issues over the previous years with various concerns about the health risks posed by the level of pollution in the river to the surrounding communities. The aim of the study was to investigate the ecological status of the river through physico-chemical assessment of water and sediment in the river; biological and habitat assessment of macroinvertebrates; and finally, the development of recommendations for a management plan for rehabilitation. Field surveys were undertaken during the wet season (September 2018) and dry season (June 2019). In-situ water quality parameters were measured during field visits. Laboratory analyses were performed on nutrients, total phosphates, chlorophyll-a and faecal coliforms. The presence of metals and chemical compounds (OCPs, SVOCs, PCBs and Phenols) was also determined in both water and sediment through lab analyses. Macroinvertebrate assessment and habitat assessment was conducted through South African Scoring System version 5 (SASS) and Integrated Habitat Assessment System (IHAS) to determine the abundance and diversity of macroinvertebrate communities and the availability of habitat. The water quality results revealed generally poor conditions with minimal seasonal variations; showing low dissolved oxygen, and high faecal coliforms and nutrient concentrations. Metal concentrations showed variations with some metals present in intolerable amounts. Chemical compounds also showed higher concentrations for sediment, with OCPs such as DDT showing higher concentrations at sites close to agriculture fields. Finally, macroinvertebrate results showed poor diversity and abundance of macroinvertebrate taxa with low SASS scores and ASPT values; with all taxa identified being pollution tolerant. Habitat assessment results also generally showed poor availability in habitat quality and mostly supporting the poor diversity and abundance of macroinvertebrate communities. The general interpretation of the results is that the system is negatively impacted, and the ecological integrity is degraded. These results indicate that a strong management plan ought to be developed with stringent rehabilitative measures. As such, recommendations for a management plan which includes multi-departmental collaboration and community engagement, including water quality improvement measures are also provided in this study.

Key words: SVOCs, OCPs, PCBs, Biomonitoring, Management plan.

CHAPTER 1 INTRODUCTION

1.1. BACKGROUND TO THE STUDY

Water is one of the most essential natural resources in the world (Abbaspour, 2011; Hashim et al., 2018) and is also one of the essential ingredients for socio-economic development (Macatsha, 2005). Approximately 71% of the earth’s surface is covered by water, of which 96.5% is stored in the oceans (USGS, 2016). Freshwater accounts for only 0.01% of the earth’s water, with just 0.8% of it found on the earth’s surface (USGS, 2016). Unfortunately, these resources are one of the most endangered natural resources on the planet (Fierro et al., 2017). Although water quantity has been the leading factor contributing to the global water crisis, water quality is increasingly being recognised to be at the core of the water crisis and being as significant as water scarcity (Abbaspour, 2011). Water quality is a worldwide problem due to various factors and Abbaspour (2011) asserts that although not all countries experience water shortage, all countries do, however, experience the degradation of water quality at varying extents.

Water resources pollution is the leading cause of water quality problems around the world (Zhulidov et al., 2001; Palaniappa et al., 2010; UN, 2012; du Plessis, 2017). Pollution stems from various sources which contribute to water quality problems, and these generally include industrial effluent, run-off from urban and croplands, and sewage discharge (Abbaspour, 2011). Fierro et al. (2017) further added that land use changes largely contribute to the endangerment of fresh waters and that the problem has been augmented in the last decade. Land use conversion, mostly for agriculture, has a negative impact on the surrounding ecosystems for it leads to extensive modifications of agricultural land (UN, 2012; du Plessis, 2017; Fierro et al., 2017). In most cases, this can cause deforestation, which may extend to the river banks and consequently leads to increased temperature and quantity of light in river water (du Plessis, 2017; Fierro et al., 2017).

South Africa is not free from the water problems faced in the world. It is ranked as the 30th driest country in the world with an average rainfall of 450 mm per annum and an uneven distribution of water across the country (CSIR, 2010; DWA, 2013a; DWS, 2018). More so, some parts of the country, particularly the Western Cape, recently experienced water issues in the form of water shortages, which are drought-induced (Zaheer, 2018). Amid the drought problems faced by the country, most of the country’s freshwater resources are continuously threatened by human activities (Zamxaka et al., 2004; Turpie et al., 2008; UNEP-FI, 2009;

DWA, 2011; Bek et al., 2017). Rapid population growth coupled with increased development and urbanization has resulted in a major increase in municipal and industrial pollution of water (Fatoki et. al., 2001; Zamxaka et al., 2004; Mekonnen and Hoekstra, 2016). In areas that are less industrialized, pollution from human settlements, lack of proper sanitation, agricultural activities and leachate from poorly managed household waste are some of the main sources of pollution to surface water (Zamxaka et al., 2004; Rand Water, 2018). This not only leads to the degradation of water resources but to the shortage of freshwater (Barrington et al., 2013). Subsequently, freshwater shortages will further lead to more water problems, as South Africa is already deemed a water scarce country (DWS, 2018).

In order to resolve the country’s projected water problems, collaborative action is required from all affected parties, including the respective communities. Public participation in water management, also known as community-based water resource management (CBWRM) is an approach that embraces the principles of individual, household and community participation on issues that directly or indirectly affect their livelihoods and future (Tantoh and Simatele, 2017). Gruber (2011) has identified the involvement of communities in natural resources management as one of the effective approaches to the sustainable management of shared resources. Moreover, Stone and Stone (2013) view public participation in water resources management as one of the avenues to facilitate the relationship between the improvement of community livelihoods and natural resources conservation.

1.2. PROBLEM STATEMENT AND JUSTIFICATION FOR THE STUDY

As previously highlighted, South Africa is not exempt from water quality challenges. Major surface water resources in the country are faced with extreme degradation as a result of pollution (Fatoki, et al., 2001; Zamxaka, et al., 2004; CSIR, 2010; Neswiswi, 2014). The degradation of river systems can thus threaten the environment and the health of surrounding communities, particularly high-density and low-income communities (Owusu- Asante, 2008). These are problems experienced across the country, more so in less industrialised areas that lack proper sanitation facilities and waste removal services, thereby converting river to tap systems, toilet facilities and landfill sites (Zamxaka, et al., 2004). These factors not only lead to physical changes in the state of water, but to chemical changes, which may subsequently lead to outbreaks of water-borne diseases (Zamxaka et al., 2004).

The Kaalspruit has been plagued with water quality issues over the previous years with various concerns about the health risks posed by the level of pollution in the river to the surrounding communities (Batt, 2015). One of the major causes of extreme pollution in the 2 river is the sewage leak discharging into the river, which carries high concentrations of faecal coliforms (Quintal, 2015). The ecological integrity of the river is of high environmental concern and the level of degradation is not clearly documented from the several studies that looked at pollution issues within this system, which still leaves the biological aspect of the river poorly documented and under-researched. Additionally, the studies featured the Kaalspruit as part of the hydrographic systems studied and not as the main river system (Nawn, 2004; Neswiswi, 2014). Only one study by Walsh and Grobler (2016) was conducted to undertake a comprehensive assessment of the river and the three aspects (physico- chemical and biological aspects) of water quality in the area. However, the study only focused on a small segment of the river, and thus did not provide adequate scientific documentation of the ecological integrity of the entire river. The study is also based on a single investigation and sampling from one season and there is no comparison of seasonal variations of water quality. Therefore, a comprehensive study investigating all three aspects and covering a significant portion of the river is required to broadly capture the state of the river. This type of analysis is crucial for the development of a management plan for the water system.

Furthermore, stakeholder engagement in water management has been poorly performed in the area. A recent study by Mashazi et al. (2019) was conducted to evaluate stakeholder participation in the river system. The study revealed that surrounding industries have not been instrumental and involved in the management and rehabilitation action for the system. These are industrials that could potentially be greatly contributing to the poor conditions in the river. The surrounding communities have also not been engaged in order to discern the kind of impacts and their extent therein, posed by poor levels of water quality in the river.

The involvement of the above-mentioned affected parties could be beneficial for the study, as Pollard and du Toit (2008) ascertained that public participation can be crucial in providing some of the solutions for the management of water resources. On the contrary, the non- involvement and poor participation of local communities and other affected stakeholders in the management and conservation of the river indirectly contributes to the deteriorating state of the river as it leads to the careless attitudes by the communities towards water resources. Whereas, when communities believe they are included in the management of the watercourse, they will grow a sense of responsibility towards the river. This may result in the provision of better care and protection for the river and the condemnation of activities that would leave the river in dire conditions. The results will be positive perception and attitudes towards the river and therefore improved conditions in the river.

1.3. AIMS AND OBJECTIVES OF THE STUDY

The aim of the study was to determine the ecological status of the Kaalspruit in order to develop a management plan for the system. This was achieved through the following objectives:

• A physical and chemical assessment of the water quality at selected sites within the river; • A physical and chemical assessment of the sediment quality at selected sites within the river; • A habitat assessment and biological assessment of the macroinvertebrate communities within the river; • Development of a management plan for effective administration and conservation of the river.

1.4. STRUCTURE OF THE REPORT

Chapter 1 is the introduction to the study whereby water quality problems facing the country and the rest of the globe are identified. Research aims/objectives and justification for the study are also presented in this chapter.

Chapter 2 presents a literature review, which provides definitions to key concepts of water quality monitoring. The key aspects covered in this chapter are water quality definitions; water quality problems faced by the country; water quality monitoring and the parameters to be monitored; and finally, water quality management is addressed, including management plans.

Chapter 3 provides a description of the study area as well as the methodology adopted for this study.

Chapter 4 presents the results obtained for the current study from the measured physical and chemical parameters both on water and sediment.

Chapter 5 is a discussion of the obtained results, providing the significance and the implications of the reported results.

Chapter 6 provides a conclusion for the current study and presents recommendations for a management plan for rehabilitation of the Kaalspruit.

CHAPTER 2

LITERATURE REVIEW

2.1. INTRODUCTION

The current chapter serves to document existing literature on aspects relating to water quality and water quality monitoring. The first section covers water quality and concepts associated with water quality, and also provide a glimpse of water quality status of South Africa, including water quality governance. This section is followed by a discussion on water quality management plan which is an important tool in water quality management and monitoring. Water quality monitoring programmes are subsequently highlighted to engage on their importance in ensuring the success of environmental monitoring. Following this is the discussion of water quality monitoring, which provides definition of water quality monitoring as well as indicating the importance of water quality monitoring. Common water monitoring parameters that are often used as quality indicators, are also defined and presented and their significance in water quality monitoring indicated. Several studies that also included these parameters for their water quality assessments are also documented to highlight the wide usage of respective parameters across the globe and their effectiveness in such water quality studies.

Following this is a section that discusses biological monitoring (biomonitoring) as a component of water quality studies. In this section, different biomonitoring techniques are highlighted, but more light is shone on the South African Scoring System (SASS5), which is a widely used macroinvertebrate biomonitoring technique. Finally, water resources management is discussed, with special focus on Integrated Water Resources Management (IWRM). Under IWRM, an important element of this concept, that is community-based water resources management (CBWRM), is defined and discussed. Several studies conducted on CBWRM are also documented to depict the importance and effectiveness of this approach in solving water quality problems.

2.2. WATER QUALITY

There is no single, clear and correct definition for water quality and according to du Plessis (2017) the definition of water quality has evolved over time and has come to integrate the elements of water usage requirements and the measurement and interpretation of water properties. Davis and McCuen (2005) provided a definition for water quality based on the physico-chemical parameters that determine the usability of water for a particular purpose. The South African National Water Act (1998) provides a comprehensive definition of water resource quality and thus defines it as:

“the quality of all aspects of water resource including–

a) The quality, pattern, timing, water level and assurance of instream flow; b) Water quality, including physical, chemical and biological characteristics of the water; c) The character and condition of the instream and riparian habitat; and d) The characteristics, condition and distribution of the aquatic biota.”

Essentially, water quality determines the functionality of water for various or intended purposes (UN, 2012). This indicates that the suitability of water for use is dependent on the respective function of which the water is required to complete. Water quality is altered by both natural and anthropogenic factors such as dissolution and leachate of rock minerals, erosion and weathering, industrial development, wastewater discharge, agriculture, urbanization, mining and recreation, which alter the water use potential (Abbaspour, 2011). It is further stated by Namugize and Jewitt (2018) that although natural and anthropogenic factors can negatively alter the quality of water, human activities contribute more greatly to water quality problems than natural processes. The natural contribution is often minimal and often causes less to no harm to aquatic ecosystems and human life (Namugize and Jewitt, 2018).

2.2.1. Water pollution

Water pollution is one of the main factors affecting water quality and can pose significant dangers to the natural state of water (Zhulidov, 2001; CSIR, 2010; Abbaspour, 2011; du Plessis, 2017). Water pollution is defined by Davies and Day (1998) as water which is harmful to plant, animal and human life. Lui et al. (2011) further define water pollution as the introduction of substances into the water, either directly or indirectly, which leads to detrimental effects that can harm living organisms, natural environment and restrict certain activities. Water pollution is also defined by the World Wide Fund for Nature as a process whereby toxic substances, also known as pollutants, are introduced into water resources, dissolve in the water and wind up either suspended or deposited on the bed (WWF, 2019).

These pollutants alter the chemical and physical properties of water in its natural state rendering it unfit for use and for performing various intended functions, resulting in the particular water considered as polluted (du Plessis, 2017). The alteration of the characteristics of water is a result of the interaction of physical and ecological processes, which could potentially contribute positively or negatively to the overall health of the water body (du Plessis, 2017).

Each activity performed in the water, including waste discharges and abstraction of water have the potential to negatively affect water quality (du Plessis, 2017). Various human activities that lead to the derivation of organic matter are considered as large contributors to water pollution, which often results in oxygen reduction in the water, consequently killing aquatic organisms (Voutsa et al. 2001). Anthropogenic sources of water pollution can be considered as point or non-point/diffuse sources (du Plessis, 2017).

a) Point sources

A point source pollutant is defined by Spoolman and Miller (2012) as a pollutant whereby its point of entry into a water body is defined. Therefore, point sources can be easily identified and managed since their point of entry can be specified (du Plessis, 2017). Major point sources affecting the world’s water bodies are industrial effluent, as well as discharge from industries and mines (Zamxaka et al., 2004; Abbaspour, 2011; du Plessis, 2017).

b) Non-point sources

Non-point sources or diffuse sources of water pollution are defined as pollutants that are not attributed to a single point or activity (Spoolman and Miller, 2012). However, du Plessis (2017) states that diffuse sources might result from several point sources feeding the water body. Diffuse pollutants have become a growing problem to water resources as they have been associated with various water quality problems such as eutrophication and acidification (du Plessis, 2017). According to du Plessis (2017) major sources of diffuse pollutants are a) agricultural runoff, which constitutes high concentrations of nutrients such as nitrates, phosphates and sulphates; b) urban runoff which may contain industrial organic pollutants, and urban garden fertilizers and pesticides; and c) waste disposal sites.

2.2.2. Water quality status in South Africa

The environment and most of its constituents (living organisms, non-living organisms and ecosystems) are all in need of safe and adequate water. Lack of this service can lead to the hindrance of socio-economic development in many countries (Namugize and Jewitt, 2018).

Therefore, the achievement of acceptable water quality is essential in order to realise the successful functioning of the environment and society. Globally, many countries experience water quality problems as most of their rivers have been altered (Yuan et al., 2005; Abbaspour, 2011; du Plessis, 2017; Mauerhofer et al., 2018; Zhao and Khan, 2019). South Africa is no exception, thus not immune to the said water quality problems.

The Council for Scientific and Industrial Research (CSIR) has revealed that the quality of the country’s freshwater resources has deteriorated as a result of increased industrial pollution, urbanization, mining, afforestation, and agriculture (CSIR, 2010). Other factors that aggravate the problem are worn out and aging infrastructure and operators that lack the necessary skills (Rietveld et al., 2009). These factors further pose a threat to human and ecosystem health. The country’s accelerated population growth rates have largely impacted on water resources through water use and waste discharge, to levels that pollutants will continue to cumulate even with no population growth (CSIR, 2010). Water quality is mostly affected by human activities. Oberholster et al. (2010) assert that since the locations of many of the country’s metropolitan areas are on watersheds; dams located downstream of these areas have shown increased contamination during recent decades. Many rivers in the country experience poor water quality and have high turbidity as a result of clay and silt soil types (CSIR, 2010) and this has been further compromised by the development of the country’s catchment systems (Namugize and Jewitt, 2018). This situation will therefore affect the quality of water supplied to consumers (Oberholster et al., 2010).

It is reported that a greater proportion of sewage in urban areas is improperly treated before it is discharged due treatment plants being damaged or improperly managed (CSIR, 2010). Moreover, effluent discharges from households, and mining contribute to the deterioration of water quality (du Plessis, 2017). du Plessis (2017) further states that industrial development has a significant role to play in degrading water resources quality as most industrial processes eliminate waste containing hazardous substances, and are discharged directly into water bodies. The state of rivers in South Africa is also a threat to the agriculture sector. A study conducted by the Water Research Commission revealed that the state of microbiological elements in the country’s rivers is cause of concern and therefore do not adhere to the international faecal requirements for safe irrigation water (WRC, 2016). The problem is ascribed to the issues of poor sewage treatment works and inadequate sanitation facilities across the country (WRC, 2016). Since farmers are dependent on rivers for irrigation, the contamination of rivers by microbial elements is a health hazard to the farm workers and consumers (Erasmus, 2017). These issues prove the necessity for efficient management of water resources and water quality monitoring. Moreover, they highlight the need for stringent environmental legislation, and where legislation is already in place, the 8 need for strong implementation. Proper implementation of legislation and stringent control activities will ensure that water resources are protected and conserved in a sustainable manner and thus not threatened.

2.2.3. Water resources governance in South Africa

Water is a basic need required for survival and an essential element of economic growth. Almost all sectors require water in order to have an output. Industrial, mining, agriculture, and the energy sectors are reliant on water in order for production to occur (CSIR, 2010). Water is also an essential aspect to human life as human beings and their functioning. It is therefore empirical to enact and enforce laws that would ensure the protection of water resources in order to support human life and other activities.

• The Constitution of the Republic of South Africa (Act No.108 of 1996)

The South African Constitution is the supreme law of the country and all laws must be consistent with the constitution (Kidd, 2011). Section 27 of the constitution stipulates the right for everyone to have sufficient food and water. Furthermore, section 24 states that everyone has the right to an environment that is not harmful to their health or well-being; and to have the environment protected, for the benefit of present and future generations, through reasonable legislative and other measures that prevent pollution, promote conservation; and secure ecologically sustainable development. These sections lay a foundation for all environmental legislation and that all laws enacted for the environment, such as water, waste, land and others are aligned with the constitution and promote sustainability in all natural resources.

• National Environmental Management Act (NEMA) (Act No. 107 of 1998)

NEMA (Act No. 107 of 1998) is the framework environmental legislation in South Africa. It gives effect to section 24 of the South African Constitution by providing constitution for environmental and promote an environment that is not harmful too human health and wellbeing (Bosman, 2009). The Act contains principles in section 2 to ensure quality environmental decisions and outlines procedures for improving decisions that may affect the environment (Republic of South Africa, 1998a). NEMA (Act No. 107 of 1998) contains a number of instruments to promote and give effect to the principle of co-operative governance and sets a framework for integrated environmental management in all development activities in the country (Bosman, 2009). The Act also calls for the enactment of Specific Environmental Management Acts (SEMAs) that are specific to each aspect of the environment and govern each aspect.

• National Water Services Act (Act No. 108 of 1997)

The National Water Services Act (NWSA) (Act No. 108 of 1997) holds local responsibility over water (Republic of South Africa, 1997). The management of water resources is the national government’s responsibility, while the local government is responsible for the management of water and sanitation services in the municipalities (De la Harpe, 1999). Therefore, the National Water Act is responsible for the sources of water while the NWSA is responsible for water services.

• National Water Act (Act No. 36 of 1998)

The South African National Water Act (NWA) (Act No. 36 of 1998) is one of the SEMAs of environmental legislation, and is the overarching legislation for the Management of South Africa’s water resources. The purpose of the National Water Act is to ensure that the nation’s water resources are protected, used, developed, controlled, conserved and managed in a sustainable and equitable manner for the benefit of all (Republic of South Africa, 1998b). The NWA (Act No. 36 of 1998) is important because it provides a constitution for the protection of water resources, acts against exploitation of water resources and promote water security for social and economic development (De la Harpe and Ramsden, 1999). The Act recognises the importance of human life and the environment and thus makes provision for sparing water for the basic human needs reserve and the ecological reserve. The basic human needs reserve is water reserved for basic human needs such as drinking; health and hygiene; and food preparation, while the ecological reserve is water reserved to the protection of water ecosystems of the country’s water resources (Republic of South Africa, 1998b). Water for these two aspects must always be safeguarded and this should be done before water is allocate to economic activities such as mining, industry and agriculture (De la Harpe and Ramsden, 1999). In essence, the NWA acts as a tool to protect water resources from threat and degradation.

The national government has divided the country into water management areas (WMA), which were previously 19 and are now merged to produce nine new WMAs (Figure 2.1). The NWA further recommends the development of a Catchment Management Strategy (CMS) for each WMA (Macatsha, 2005). This is the responsibility of a Catchment Management Agency (CMA).

Figure 2.1: Water Management Areas of South Africa (Source: DWS, 2016).

These WMAs need to be protected and their quality statuses monitored. Therefore, it is the responsibility of the department of water and sanitation to monitor water quality and report on the river’s statuses. Chapter 14 of the NWA (1998) requires the Minister to establish national monitoring systems for the collection of appropriate data and information that is adequate and responsive to the present and future challenges of efficient management of the country's water resources. The NWA (1998) further states that a status report should cover: inorganic chemical water quality; trophic status of water resources; microbial water quality, organic chemical water quality, aquatic ecosystem health, and radioactivity levels in water resources.

• National Water Resources Strategy

One other legislation which provides a legislative mandate specifically for the management of water resources is the National Water Resource Strategy (NWRS) (DWA, 2013b). The purpose of the strategy is to provide procedures that will bring the NWA (1998) to life and ensuring that the nation’s water resources are protected, used, developed, conserved, managed and controlled in an efficient and sustainable manner (DWA, 2013b). Chapter 13 of the strategy stipulates that the collection of data and interpretation of information on water and sanitation are critical to all aspects of water and sanitation management, as without accurate information the correct picture of the situation cannot be determined and policy formulation could be compromised (DWA, 2013b). One important thing to draw from the 11

NWRS is the recognition that water is a scarce commodity and thus requires cautious management to achieve equitable allocation of basic water services, while allowing economic growth and avoiding placing the integrity of aquatic ecosystems under threat (DWA, 2013b). The NWRS acknowledges that water is inadequate in many catchment areas and therefore the country has to explore other methods of recovering and conserving water such as desalination, groundwater use, rain water harvesting and other measures (DWA, 2013b).

• South African Water quality standards

The Department of Water Affairs and Forestry (DWAF) produced a series of eight volumes comprising the South African water quality guidelines which are used to set standards and acceptable limits for water quality constituents. The eight guidelines provide standards for different uses for water and are as follows: domestic water use; recreational water use; industrial water use; agricultural water use: irrigation; agricultural water use: livestock watering; agricultural water use: aquaculture; aquatic ecosystems; and field guide. Guidelines for domestic use apply to water used for domestic use despite the source (borehole, river, municipal supply (DWAF, 1996a). The guidelines for aquatic ecosystems protection were developed primarily for safeguarding freshwater ecosystems through the derivation of a set of water quality criteria (DWAF, 1996b). The guidelines stipulate, amongst others, criteria for chronic and acute effects for constituents that are toxic; criteria for the protection against changes in trophic statuses of aquatic ecosystems; and criteria for the protection of aquatic ecosystems functioning (DWAF, 1996b). The constituents represented in the guidelines were selected based on priorities distinguished by the Department of Environmental Affairs and Forestry (DWAF, 1996b). It is therefore essential to ensure that the constituents are within specified limits and that water resources are monitored with effective and sound monitoring programmes to ensure that they meet the water quality requirements.

2.2.4. Water quality management plan

Water resource management activities are borne from a water quality management plan and the effectiveness of such management is dependent on how well drafted the plan was. According to Water Prevention Pollution Organization (WPP) (2011) a water quality management plan (WQMP) is a guidance document that will assist in ensuring that water management projects comply with respective legislative requirements. DWAF (2001) define a WQMP as a draft which specifies the actions of management, tasks, resources and timeframes required to achieve the objectives set on the water quality management strategy. 12

DWA (2011) assert that the overall aim of the water management plan is to guide the sustainable management of water to ensure that growth and developmental needs of the water resource are met. In order to meet the needs, DWAF (2001) notes that the plans may: focus on point and non-point sources and be use-oriented; involve one or multiple water quality components; be based on statutory requirements, and cooperation and capacity building; and be based on a certain protocol’s specifications (DWAF, 2001).

Furthermore, DWAF (2001) identifies the three steps that the water quality management planning should follow and they are:

Step 1: Evaluate existing source directed controls:

The first step towards water quality management planning is understanding water authorisation conditions, as these conditions should be sufficient to support the water resource. Therefore, an evaluation of the impact of full compliance with the water use authorisation conditions should be undertaken.

Step 2: Identify and evaluate other possible options

Other management options should be explored in cases where the current authorisation conditions cannot meet the allocated load. This may include, inter alia, legislative water use controls, involving strict authorisation conditions; and the in-stream management through water resource rehabilitation.

Step 3: water quality management plan formulation

The above-mentioned elements should be arranged in a management plan. The plan should include the following: required management actions for achieving load allocations; tasks and responsibilities for the implementation of the actions; timeframes of implementation; specifications of the required resources; and finally, the monitoring and auditing requirements for implementation appraisal.

These phases will ensure a successful undertaking of the water resource management planning process. This is one of the approaches that can be considered for the process. Day (2009) also presents a framework for effective community-based water resources management which allows communities to participate in the management of water resources and assets. As opined by Day (2009), the approach will inspire communities to become partners in water quality management. This framework comprises of eight phases intended to be approaches that encourage the participation of people at grassroots levels from the start (Day, 2009). Figure 2.2 is a summary of the framework.

Figure 2.2: Community-based water resource management framework (Source: Day, 2009).

A South African case study of a water quality management plan is by the Department of Water Affairs, Western Cape provincial government in South Africa. The provincial government drafted a water management plan for the sustainable growth and development in the Western Cape Province (WCDWA, 2012). In order to achieve the plan, four key goals were identified and they are: to ensure co-operative governance in water management; to ensure the sustainable development of water resources; to uphold the integrity of socio- economic systems; and finally, to ensure transparency and awareness building of water resources management (WCDWA, 2012). As a way to inform the four core goals of the plan, twelve themes were integrated with the goals to present a holistic water plan. Figure 2.3 presents a visual representation of the integration of the themes and the goals.

Figure 2.3: The 12 Themes (outer circles) are integrated to inform the 4 Strategic Goals (inner rectangles) of the Water Plan (Source: WCDWA, 2012).

Water quality management plans stipulate management actions, responsibilities and resources (DWA, 2011). Subsequently, these plans should be complemented by programmes that will honour the execution of management plans and bring the management plans to life.

2.2.5. National water quality monitoring programmes

The obligation to report on the water quality status breeds the need for development of monitoring networks and programmes that will constantly monitor water resources and provide a review on their state. The following national monitoring programmes have been established by the South African government: National Chemical Monitoring Programme; National Microbial Monitoring Programme; National eutrophication Monitoring Programme; National Toxicity Monitoring Programme, National Radioactivity Monitoring Programme; and the National Aquatic Ecosystem Health Monitoring Programme (NAEHMP) (Table 2.1)

(Mogakabe, 2017). Furthermore, NAEHMP has three components namely: River Ecosystem Monitoring Programme (REMP), National Wetlands Monitoring Programme (NWMP), and National Estuaries Monitoring Programme (NESMP) (Mogakabe, 2017).

Table 2.1: Monitoring programmes in South Africa (Source: Mogakabe, 2017).

Programme Objective Parameters Reporting Chemical Assess status and trends Water quality On demand; bi-annual Monitoring of water chemistry samples

Microbial Assess status and trends Microbes (E. coli, Bi-monthly; annual Monitoring of faecal pollution Faecal coliform)

Eutrophication Assess status and trends in Phosphates, Nitrogenous On demand; annual Monitoring dams and lakes compounds, chlorophyll, algae, cyanobacteria Toxicity Status and trends of Toxicants and toxicity Regularly Monitoring toxicity and toxicants

Radioactivity Assess status and trends Concentrations of radio- Regularly of radiological water quality nuclides

NAEHMP Status and trends of Biological indicator (fish, Annually ecological state of rivers, vegetation, invertebrates) wetlands and estuaries Geohydrological Status and trends Rainfall depth and chemical Bi-annually monitoring character, conductivity and temperature

2.3. WATER QUALITY MONITORING

Strobl and Robillard (2008) define water quality monitoring as the practice of collecting quantitative data on the physical, chemical and biological characteristics of a water resource over a period of time and space using samples acquired from the water body being monitored. It can also be defined as a systematic, constant and on-going inspection and measurement in order to provide an account of the variations in water quality over time and location (Macatsha, 2005). Further, the International organisation for standardization (ISO) describes water quality monitoring as “the programmed process of sampling, measurement and subsequent recording or signalling, or both, of various water characteristics, often with the aim of assessing conformity to specified objective” (ISO, 2015). The definitions of water 16 quality monitoring all identify and share common key elements that form the monitoring process and those key elements are observation, measurement and recording of the parameters, which are done over a particular time and space in order to draw a conclusion of the overall status of water quality. This process allows for the determination of trends observed in a particular water body, over a particular period (Chabalala, 2017).

Water quality monitoring and water quality management are often used interchangeably, although they do not refer to the same process. Water quality management, as defined in the previous sections, is broad and includes the process of water quality monitoring. That is, water quality monitoring is a component of water quality management. Water quality monitoring can be simplest sense mean constant observation of water to ensure compliance with the laws (Macatsha, 2005). Subsequently, Zhulidov et al. (2001) deem water quality monitoring as a vital public service for managing water resources including planning, evaluation, control, and the protection of human health.

Water quality monitoring can be illustrated in a diagram which shows the core activities that act as the components of water quality monitoring (Figure 2.4). Macatsha (2005) opines that the primary principle of monitoring is that it should be perceived as a sequence of interrelated activities which begin with the description of the needed information and end with the use of information results.

Figure 2.4: Water monitoring cycle (Source: Chilundo et al., 2008).

The water monitoring cycle places emphasis on the fact that the primary objective of monitoring is to provide information, not just data (Macatsha, 2005). The aim is to shift away from the “data rich but poor information syndrome” from the monitoring programmes of the

17 past (Chilundo et al., 2008). Therefore, according to Macatsha (2005) the evaluation of water quality monitoring programmes must commence with the question “why do we monitor?”. This question alone will define the rationale for monitoring as it will influence the monitoring activities to be undertaken such as setting up the network, parameters to be measures, the use of information, data analysis and reporting (Macatsha, 2005).

2.3.1. The rationale for monitoring water resources

A myriad of complex problems arising from global environmental change such as nutrient enrichment, loss of biotic diversity, contaminants and land use conversion warrant for the environment to be monitored (Hale and Hollister, 2009). Over the years, water resources have been subjected to immense pollution that is proving to be harmful to human health and aquatic ecosystems (Han et al., 2008). Human and natural activities can threaten the quality of water resources and render it unfit for use (Han et al., 2008). Therefore, the constant monitoring of water resources is necessary in order to prevent and limit pollution on the water resources. Macatsha (2005) asserts that traditionally, the principal reason for monitoring water resources was to validate the suitability of water bodies for intended uses. However, he further adds that monitoring has evolved to impact monitoring, that is, being a process where trends are determined in the quality of aquatic environments and the potential impacts that the pollutants have on the environment are identified from the anthropogenic activities. This involves the practices of estimating nutrient or pollutant loads discharged by rivers or groundwater into the lakes and oceans (Macatsha, 2005). Antonopoulos et al. (2001) provides a summary of the grounds for performing water quality monitoring which include the following: • assessment of compliance with Water Quality Objectives; • trend assessment; • general surveillance; • to provide a system-wide synopsis of water quality; • to detect actual or potential water quality problems if such problems exist; • to determine specific causes; • to assess the effect of any corrective action.

Bartram and Balance (1996) argue that a monitoring programme should not be established before a thorough scrutiny of the real needs for water quality information. Moreover, for the monitoring programme to be effective, the data requirements of the affected water users should be reflected by the monitoring process (Bartram and Balance, 1996). Water quality monitoring programmes are helpful in providing an understanding of water quality processes,

18 and also provide decision makers with the relevant information for the general management of water resources, particularly water quality management (Khalil et al., 2010). Therefore, water quality monitoring can provide information that can be used as indicators of water pollution.

Macatsha (2005) argues that water quality monitoring should not be a fixed process and that it must be customized according to a region’s needs and water quality or pollution problems. Therefore, the methods and strategies of management will differ between different institutions with different problems, resources and priorities. Each region or country may have different goals in which they seek to achieve through the water quality monitoring programmes, and those goals may even differ between different regions in the same country (Macatsha, 2005). These differences result in varying approaches in the design and implementation of monitoring programmes, the choice of parameters to monitor, the location and the number of times measurements will be taken, and finally, data handling and reporting (Bartram and Balance, 1996). According to Macatsha (2005) South Africa had decided on their scope of water quality monitoring which involves the following components: hydrological monitoring, resource quality monitoring, water resources monitoring. Hydrological monitoring comprises of monitoring the quality and quantity of surface and groundwater; resource quality monitoring involves monitoring the quality and quantity of surface water and groundwater including their ecosystems; water resource monitoring comprises of managing water resources both in their natural and impacted states (Macatsha, 2005). All these aspects should be included in order to attain a successful water quality programme. Furthermore, the prevention of pollution to water resources warrants effective monitoring of physico-chemical and biological parameters and failure to do so would result in the difficulty in setting water rehabilitation targets associated with water quality (Neswiswi, 2014).

2.3.2. Water quality monitoring parameters

Olsen and Robertson (2003) assert that the choice of monitoring parameters will be influenced by the monitoring objectives. They believe that because majority of the parameters can be measured using various techniques, a simple definition of which parameters will be measured is not enough. A key element of a monitoring design is knowing which parameters will be measured, as well as the timing and the location of measurement (Olsen and Robertson, 2003). In order to assess water quality and other hydrological conditions, primary data must be collected during surveys (Strobl and Robillard, 2008). This serves the purpose of determining the extent of the catchment through surveys (Neswiswi, 2014). This will then allow for the consideration of whole ranges of parameters in 19 the river basin (Neswiswi, 2014). Therefore, as asserted by Neswiswi (2014), the correct choice of parameters to be sampled is dependent on the design and functioning of a monitoring network. Ultimately, water quality parameters to be measured have an influence on the location and number of times sampling is undertaken, and therefore, should be selected based on the specific monitoring objectives or a clearly defined information "need" (Strobl and Robillard, 2008). a) In-situ physic-chemical water parameters

• pH

The pH value gives a measure of hydrogen ion activity in a water sample (DWAF, 1996b). It can be defined as a measure of how basic or acidic a solution is (WHO, 1996). The pH of pure water is known to be 7.0 at 24°C, this is where the number of OH- and H+ are equal and water is considered as neutral (DWAF, 1996b). The pH of water is essential to the survival of many aquatic organisms, and majority of the aquatic organisms are sensitive to changes in pH values (EPA, 2001). The pH of water can have an effect on activities such respiration, reproduction and photosynthesis, including the rate of chemical reaction for organisms in the water (WHO, 1996). According to DWAF (1996b) the pH value of surface waters generally ranges between 4 and 11. However, it is worth noting that the pH value may differ daily and seasonally. The Department of Water Affairs and Forestry (DWAF) (1996b) indicate that daily variations in the values of pH occur when the rates of photosynthesis and respiration differ over a 24-hour period. The value of pH is mostly affected by industrial activities. Industrial activities mostly cause acidification of water resources rather than alkalization from the following types of pollution: industrial effluent with low pH; discharges from mines, acid rain stemming from atmospheric pollution (DWAF, 1996b). The pH of water can be affected by factors such as biological activity, temperature and the amount of organic and inorganic ions in the water (WHO, 1996). Measuring pH in the water is important when the corrosivity of water is being studied, because the lower the levels of pH the more corrosive water is (WHO, 1996). Therefore, measuring the pH of particular water resources provides an indication of whether the water is fit for aquatic life or direct consumption. Therefore, pH measurements should be within the Target Water Quality Range (TWQR) (DWAF, 1996b).

• Total Dissolved Solids and Electrical conductivity

Total Dissolved Solids (TDS) is a measure of the magnitude of all the compounds dissolved in water (DWAF, 1996b). It refers to the inorganic salts and small amounts of organic matter present in water (WHO, 1996). Major substances that usually make up TDS are calcium, sodium, magnesium, potassium cations, and carbonate, chloride, sulphate and nitrate

20 anions (WHO, 1996). The TDS have a direct relationship with electrical conductivity. Electrical Conductivity (EC) is capability of water to conduct electrical current (DWAF, 1996b). This capability exists as a result of the presence of the previously mentioned ions that make up TDS, as they all possess an electrical charge (DWAF, 1996b). Water resources usually contain TDS as a result of the dissolution of minerals from rocks, soils and the decay of plant material, which are the factors that determine the type of TDS present in particular water resources (DWAF, 1996b). TDS concentrations accrue as water travels downstream as salts are added along the way (WHO, 1996). Factors that contribute to the accumulation of salts as water moves downstream are surface runoff, as well as domestic and industrial discharges into the rivers (DWAF, 1996b). Electrical Conductivity is a measure of TDS content of waters with low organic content, and the factor should generally range between 5.5 and 7.5 when EC is measured in µS/cm and TDS in mg/L (DWAF, 1996b). Concentrations of both TDS and EC should be compared to the TWQR and changes in their levels will cause changes in the structure and functions of aquatic ecosystems (DWAF, 1996b).

• Temperature

Water temperature plays a significant role in the organisms that reside in water and it influences the chemical processes in the water, including biological activity (EPA, 2001). Temperature has an effect on the rate of plant photosynthesis, the timing of organisms’ reproduction, migration and metabolic rates (EPA, 2001). The inverse relation of water temperature and dissolved oxygen implies that as the water temperature decreases, dissolved oxygen will increase, thus warmer waters will have low levels of DO than colder waters. Since temperature has interaction with other variables such as DO, measuring temperature alone will not give an indication of water resource health, and therefore should be studied in tandem with other variables, particularly the ones having direct/inverse relationships with it (EPA, 2001).

• Dissolved Oxygen

Oxygen enters water through the atmosphere and can also be generated through aquatic plant photosynthesis (DWAF, 1996b). Dissolved oxygen (DO) is considered one of the best indicators of aquatic health (EPA, 2001). Water resources containing high levels of DO are considered healthy and are capable of supporting aquatic life as it is required for the respiration of all aerobic organisms (EPA, 2001). Oxygen is required for the decomposition of organic matter; therefore, the decomposition of organic matter in large quantities can lead to severe reduction of oxygen, thus making the water uninhabitable for many aquatic organisms (EPA, 2001). Therefore, DO provides important information about the state of the 21 water and acts as a useful measure of aquatic ecosystem health (DWAF, 1996b). It is critical to maintain sufficient levels of DO to ensure that aquatic life is adequately supported. It is for these reasons that in non-contaminated water resources, DO concentrations are considered high and near saturation levels (WHO, 2004). Therefore, investigating the level of DO in freshwater resources can provide an indication of the health of the water resource and its capacity to support life. Dissolved oxygen has an inverse relationship with temperature, when the water temperatures are higher, the DO will show low measurements, and these conditions can lead to stress effects on aquatic organisms (DWAF, 1996b). The DWAF guidelines report that normal saturation concentrations for DO are: 12.77 mg/L at 5 °C; 10.08 mg/L at 15 °C; 9.09 mg/L at 20 °C (DWAF, 1996b).

Previous studies have shown the effectiveness of physico-chemical parameters in studying the water quality of freshwater resources. In-situ physico-chemical parameters are measured worldwide in water quality studies and have proven to provide an indication of the levels of contamination for particular water resources. Hashim et al. (2018) conducted a study assessing water quality in the Langat River in Malaysia, which was deemed as one of the most polluted rivers in the country. Six sampling points were selected along the stretch of the river (upstream, midstream, and downstream) to measure in-situ physico-chemical parameters, as well as microbiological parameters. The physico-chemical parameters that were measured include dissolved oxygen (DO) and biological oxygen demand (BOD), temperature, pH, and Total Suspended Solids (TSS). The results revealed sampling spot labelled P20 (which is located midstream) was the most polluted site and recorded high concentrations for parameters DO, COD and BOD (Hashim et al., 2018). It is believed that P20 recorded the highest values as it is located near a sewage treatment plant. P1, which is located upstream, appeared to be the least polluted recording the lowest values for BOD and COD (Hashim et al., 2018). The results showed great improvement in water contamination from upstream to downstream, with some downstream values for parameters exceeding threshold limits.

A similar study was conducted by Barakat et al. (2016) whereby they investigated the spatial and seasonal water quality variation of Oum Er Rbia River, in Morocco. The aim of the study was to assess the state of water quality and also identify the main sources of contamination in the river and its main tributary, El Abid River (Barakat et al., 2016). Sampling was carried out seasonally; during high water seasons (December - April) and low water seasons (April - November). The following parameters were measured in situ: temperature, pH, EC, turbidity and DO and the rest of the parameters were measured in the lab (Barakat et al., 2016). The

22 results showed that temperature was high in summer and increases downstream ranging between 9.5 °C – 39.2 °C; the pH values ranged from 6.91 – 9.25 and were within the required Moroccan standards (Barakat et al., 2016). The TSS was high in summer between 1.4 to 37043 mg/L in areas closer to the confluence; EC was observed to be high in all stations (314-3500 µS/cm; Mean DO were generally low (7mg/L) (Barakat et al., 2016).

In South Africa, Nawn (2004) investigated the water quality and hydrological status of the Hennops River and its tributaries (Kaalspruit and Olifantspruit). In order to conduct the study, water quality data of the river covering a period of two years (January 2002 – December 2003) was obtained from the Department of Water Affairs and Forestry (DWAF) and the City of Tshwane Metropolitan Municipality (CTMM) (Nawn, 2004). For measurements of parameters, twelve sampling sites were considered for the study and all the points were sampled 32 times over the two-year period (Nawn, 2004). The parameters analysed in the study were electrical conductivity, TDS, TSS, COD, pH and other nutrients. According to Nawn (2004) the results revealed that 50% of the studied constituents do not comply with the water quality guidelines. Generally, it was noted that upstream sections of the study area recorded higher average constituent values, where fish species have become extinct. This is due to the discharge of the Kaalspruit into the Hennops River further upstream, and with the Kaalspruit believed to be highly polluted (Nawn, 2004).

Walsh and Grobler (2016) also conducted a wide-ranging study in South Africa. The study was directed to assess the river health of the Kaalspruit, South Africa. The aim of the study was to ascertain the Ecological State (ES) and Environmental Importance and Sensitivity (EIS) of the aquatic ecosystem (Walsh and Grobler, 2016). The study focused on the Kaalspruit and the surrounding wetlands in the area. Unlike the previously highlighted studies, only three sampling points were selected for this study where the physico-chemical parameters measured included temperature, pH, EC, DO as well as other chemical parameters and nutrients. According to Walsh and Grobler (2016), the results showed intolerable levels of DO and high but tolerable levels of EC. pH values were high but fairly alkaline, which was within the limits of aquatic ecosystems. All three sites revealed to be oxygen deficient. b) Nutrients and biological components • Nitrate and nitrite

Nitrates and nitrites are ions which are naturally occurring and are constituents of the nitrogen cycle (WHO, 1996). Nitrite is the inorganic intermediate and nitrate is the by-product of nitrogen and ammonia oxidation (DWAF, 1996b). Nitrate is more abundant in aquatic

23 ecosystems than nitrite and thus more stable (DWAF, 1996b). Additionally, nitrate is not directly toxic but its conversion to nitrite renders it a hazard (DWAF, 1996b). Although nitrate can naturally occur in water from the dissolution of minerals in rocks and soils, anthropogenic factors such as agricultural run-off containing fertilizers, waste run-off, or human and animal wastes contribute to the high levels of nitrates in water (WHO, 1996). The EPA (2001) points that rivers that show high levels of nitrate provides the implication of significant run-off from agricultural fields than any other factors. Nitrate concentrations thus have dire impacts in water resources and can result in eutrophication problems in affected watercourses (DWAF, 1996b). Nitrate concentrations in water have important relationships with variables such as DO and pH. In waters where nitrate levels are spiked, DO levels decreases and pH levels rise becoming more acidic (DWAF, 1996b).

• Phosphates

Phosphorus exists naturally in plants, micro-organisms, and animal wastes and may also be found in waters as dissolved particles (EPA, 2001). Elemental phosphorus is not found in the natural environment, but can occur as orthophosphates, polyphosphates, metaphosphates, pyrophosphates which are mostly found in water (DWAF, 1996b). From the group of phosphates, orthophosphates are the only forms of inorganic phosphorus used by organisms in water (DWAF, 1996b). Phosphorus is naturally a product of rock weathering and the leaching of phosphate salts into the waters (DWAF, 1996b). Phosphorus can also be found in agricultural fertilizers domestic detergents (EPA, 2001). Run-off and sewage discharges are therefore considered as major contributors to surface waters (EPA, 201). Natural and insignificant amounts of phosphates into water bodies are acceptable; problems only begin to occur when the salts are deposited in abundance into the water. Therefore, phosphates reaching surface water in large amounts, and further interacting with nitrates can promote the overgrowth of algae, which are the major the causes of eutrophication (EPA, 2001). This indicates increased levels of minerals and organic nutrients and thus a decrease in dissolved oxygen (EPA, 2001). It is therefore empirical to control phosphates levels to avoid algal overgrowth to further avoid the depletion of oxygen which results in the deaths of aquatic organisms.

• Chlorophyll

Cyanobacteria are bacteria that share some of the properties with algae and they contain chlorophyll-a (WHO, 2004). According to the EPA (2001) chlorophyll is considered as one of the significant parameters in water quality assessment, particularly for lakes, as they provide an indication of whether or not water bodies are enriched with nutrients such as phosphorus,

24 nitrates and nitrites (EPA, 2001). The presence of these nutrients in abundance can lead to eutrophication and subsequently algal blooms (WHO, 2004). These are surface accumulation of algae which have dire impacts on dissolved oxygen (WHO, 2004). One of the primary indicators of the presence of algae is musty taste or odour (WHO, 2004). Therefore, in cases where water is directly used for drinking, consumers may be subjected to taste and odour problems. It is therefore necessary to test water for chlorophyll presence in order to determine its fitness for use.

• Thermotolerant (faecal) coliform bacteria

Thermotolerant (faecal) coliform bacteria are regarded as organisms that are able to ferment lactose at 44-45 °C (WHO, 1996). E. coli is one of the organisms in this group, and it is the only organism of strictly faecal origin (WHO, 1996). Thermotolerant coliforms, excluding E. coli, may also come from industrial discharges rich in organic matter or from decomposing plant matter and soils (WHO, 2004). Thermotolerant coliforms are therefore the second-best choice, after E. coli, for microbial contamination investigations. For many investigations/studies that aim to investigate water quality in rivers, the two coliforms (E. coli and thermotolerant coliforms) should be measured in order to determine the level of coliform contamination, particularly in waters that are surrounded by potential coliform sources.

• Escherichia coli

Escherichia coli (E. coli) is one of the indicators of faecal contamination. It is bacteria that is found in the normal intestines of humans and animals, and therefore transcends to the respective organisms’ faeces (WHO, 2004). E. coli can therefore be found in sewage, treated effluents and other water and soils that were subjected to faecal contamination (WHO, 1996). Therefore, the presence of E. coli in water is an indication of potential serious contamination for a particular water resource. E. coli is the faecal contamination indicator of choice than other bacteria because they usually meet most of the elements in the criteria for determining faecal contamination, and therefore normally used when microbial examination resources are limited (WHO, 1996). Therefore, in water quality investigations, water is tested for the presence of E. coli in order to detect the possible presence of faecal components. This is a common variable to be measured, particularly in watercourses straddled by industries, waste water treatment plants, agriculture fields and communities with poor sanitation facilities.

It is often inadequate to measure physico-chemical parameters alone when conducting a water quality assessment because it is not only the physical and chemical components that contribute to water pollution. Therefore, in order to acquire a comprehensive indication of the

25 all the contaminants in water, all elements should be investigated. It is for this reason that many studies conducted on water quality assessment investigates all components. On that basis thereof, the above-mentioned study by Barakat et al. (2016) in the Oum Er Rbia River, Morocco, also incorporated nitrates, phosphates and faecal coliforms as water quality indicators for their study. Their results revealed that nitrate ranged between 0 to 24.2 mg/L, which showed positive correlation with temperature implying that the nitrate concentrations are likely due to agriculture run-off (Barakat et al. 2016). Moreover, total phosphate range between 0.01 to 8.85 mg/L, with the highest values recorded upstream close to discharge points (Barakat et al. 2016). The values correlated with E. coli and TSS which indicates that the pollutants are from anthropogenic sources (Barakat et al. 2016). Finally, E. coli concentrations ranged between 0 and 120 000 CFU/100ml and were mostly recorded downstream.

Another study was conducted by Dunca (2018) to assess the water quality of major transboundary rivers (Timis and Bega rivers) in Banat, Romania. On this study, nitrates and phosphates were measured in order to determine their concentrations and relate them to the surrounding land uses (Dunca, 2018). The study was carried out through the calculation of Water Quality Index (WQI) from the water quality parameters values obtained for 10 sections of the Timis and Bega rivers. The nitrate values for all sampling sites range between 0.001 and 0.08 mg/L which are very low compared to the values calculated by Barakat et al. (2016). Moreover, total phosphates range between 0.0161 and 0.4 mg/L, and this reported to be attributed to agriculture run-off and industrial discharges (Dunca, 2018).

c) Organic compounds

• Organochlorine pesticides

Organochlorine pesticides (OCPs) are chlorinated hydrocarbons that were widely used in the agriculture sector as pesticides, and for mosquito control (WHO, 1996). Compounds that are found in the OCP group include methoxychlor; dieldrin; chlordane; toxaphene; mirex; kepone; lindane; hexachloride, and dichlorodiphenyl trichloroethane (DDT) which is the most common amongst the group (WHO, 1996). Most Organochlorine Pesticides are banned in several countries following the discovery of their harmful effects on the environment, in order to protect the environment and human health (Blus, 1997). DDT, including its derivatives, is persistent in the environment, is not degraded easily and because of these characteristics, it attaches firmly to soil particles in water upon entry (WHO, 1996). This has dire impacts on the chemical composition of water and aquatic organisms as they are likely to ingest the 26 compounds, which can lead to death (Blus, 1997). Organochlorine pesticides can therefore, be found in both water and sediment, and both matrices should be tested for the presence of these compounds during water quality investigations (Blus, 1997).

• Polychlorinated Biphenyls

Polychlorinated biphenyls (PCBs) are a group of organic chemicals comprised of carbon, hydrogen, chlorine atoms (USEPA, 2019). These compounds are known to be odourless and tasteless, and may range in consistency from oil to a waxy solid (USEPA, 2019). Polychlorinated biphenyls belong to a family of chlorinated hydrocarbons and their manufacturing was banned in 1979 for ecological considerations (EPA, 2001). Polychlorinated biphenyls were widely used in industrial and commercial applications such as electrical equipment; pigments, dyes and carbonless paper (USEPA, 2019). These compounds are ubiquitous and can therefore be found in water, air, sediments, and food (USEPA, 2019). They are toxic and can cause genetic defects and deaths in fauna and can travel through the food chain (USEPA, 2019). Investigating the levels of these compounds in water and sediment can therefore provide an indication of the type of pollution sources in particular water resources.

• Semi-volatile Organic Compounds

Semi-volatile organic compounds (SVOCs) are a subgroup of volatile organic compounds (VOCs) and that have higher boiling points than temperature (Xu and Zhang, 2011). These compounds are significant indoor pollutants are associated with various health risks such as cancer and dire impacts on the environment. Most of these SVOCs are chemicals used in the production of plastics, furniture, detergents and building materials (Xu and Zhang, 2011). Polycyclic Aromatic Hydrocarbons (PAHs) are examples of SVOCs and are found in soot, tar, car, and automobile exhausts (EPA, 2001). The major contributor of PAHs is the combustion of hydrocarbon fuels as by-products (Xu and Zhang, 2011). Exposure to/consumption of waters containing PAHs poses a threat to human, animal and ecosystem health and can lead to several health risks of cancer (lung, bladder and gastrointestinal); kidney and liver damage in humans (Xu and Zhang, 2011).

• Phenolic compounds

Phenol includes various related compounds including other phenolic types which are naturally occurring and normally do not cause problems (EPA, 2001). Problems associated with problem-causing phenols are mostly the taste and the odour which are augmented particularly when water is chlorinated (EPA, 2001). These compounds originate from 27 industrial process and are introduced into the water as industrial effluents or they can be leached materials covering the roads (EPA, 2001). Phenols can also be trapped by sediments; thus, water quality studies should also test sediments for such compounds.

Some studies were conducted previously in order to investigate the levels of SVOCs compounds in water. Some of these studies include one conducted by Samara et al. (2006) in order to determine the levels and the potential sources of PCBs and PBDEs in the sediments of the Niagara River in USA. Sediment samples were then taken from several sites along the River and sent to the lab (Samara et al., 2006). The results showed that all sampled sediments contained PBCs at detectable levels (Samara et al., 2006). The highest concentration of PCBs was observed at a site near a waste water treatment plant and several industries. The PBDEs results show the presence of PBDEs in their various forms at all sites, except one (Samara et al., 2006). The total PBDEs ranged from 0.72 to 148 ng/g, with the highest concentration observed at a site with close proximity to industrial areas (Samara et al., 2006). The authors indicate that the mostly found compounds are PCBs 138 and 153, and PBDEs 47 and 99, which are the forms mostly found in fish, therefore the presence of these in water pose significant threats to aquatic fauna (Samara et al., 2006).

Another study was conducted by Wu et al. (2009) to determine the presence of SVOCs in the waters of Yangtze River, China. The study revealed that the total concentrations of SVOCs ranged from 1950.81 to 11097.78 ng/L and there were no significant seasonal variations in their concentrations (Wu et al., 2009). The study also conducted a health risk assessment from the results and some of the potential risks include carcinogenic effects (Wu et al., 2009).

2.3.3. Biological monitoring

Pollutants do not only have an impact on the quality of water, they also have the potential to influence the ecological integrity and biodiversity of water resources (Chikodzi et al., 2017). It is for this reason that the biological diversity of water resources is also studied to ensure that the ecological integrity of a system is upheld and maintained. This can be done through biological monitoring (or biomonitoring). Biomonitoring is a process which studies the changes in biological communities, or individual organisms in water resources and how the ecosystem has been affected (Bodenstein et al., 2005). According to Chikodzi et al. (2017) biomonitoring was conceived from the realisation that physical and chemical water assessments had shortcomings, and thus the need to include biological organisms in water quality assessments was realised. Biomonitoring embodies the principle that the best indicators of the health of the environment are organisms (Kleynhans, 1999). This monitoring 28 procedure on biota is based on measuring the health of the river instead of only measuring the physico-chemical components of the system (Harding, 2005). Therefore, proper biological monitoring can result in good and acceptable biological integrity of water resources.

Biotic integrity is one of the most imperative indicators of river health (Kleynhans, 1999). It is defined as “the ability to support and maintain a balanced, integrated, adaptive community of organisms having a full range of elements (genes, species and assemblages) and processes (mutation, demography, biotic interactions, nutrient and energy dynamics, and metapopulation processes) expected in the natural habitat of the region” (Karr, 1996). Biotic integrity provides an indication of the functionality of a freshwater body and is interlinked with and/or dependent on the physical and chemical conditions of that freshwater body (Bodenstein et al., 2005). Therefore, a river can be declared healthy when all three aspects are functional and stable. It is therefore imperative to study the biotic integrity (or status) of a certain water resource in conjunction with its physico-chemical status as these concepts are not entirely exclusive and therefore should not be studied in isolation (Bodenstein et al., 2005).

Subsequently, Lucadamo et al. (2008) argue that in order to successfully incorporate biotic integrity in water resource management, there must be cost-effective procedures that measure the degradation of biota, and that can be achieved through the use of indices of biotic integrity. Different indices can be used for different aquatic species. Fish and macroinvertebrate species are amongst the widely used indicators of biotic integrity through the application/ calculation of fish indices and macroinvertebrate indices, particularly for rivers (Chikodzi et al., 2017). These indices and the other available ones in the world have an important role to play because they evaluate the impacts of aquatic ecosystem stresses caused by human activities (Chikodzi et al., 2017). This will aid in generating remedial action plans for the stressed aquatic environments.

Macroinvertebrates are spineless organisms that can be seen with the naked eye (ES, 2019). Examples of macroinvertebrates include flies, flatworms, bugs, dragonflies and other insects (ES, 2019). Many aquatic insects live as larvae in water and proceed to be flying insects in their adult phase (Hauer and Resh, 2017). These species form a major component of aquatic ecosystems biota and are associated with various aquatic ecosystems such as stony beds, marginal and aquatic vegetation as well as sediments (Chikodzi et al., 2017). Chikodzi et al. (2017) further assert that their multi-habitat nature makes them a ubiquitous and diverse group of aquatic organisms, which enhances their ecological role in nutrient cycling in aquatic ecosystems. It is for this reason that macroinvertebrates are considered as

29 ideal organisms in freshwater biomonitoring studies (Chikodzi et al., 2017). Macroinvertebrates have different characteristics and react differently to water pollution; some are pollution tolerant; some are slightly tolerant to pollution and some are sensitive to pollution (Merrit et al., 2008). These species are considered as excellent indicators of water quality for various reasons. Begum et al. (2014) indicate that they react differently to different types and degrees of pollution, including heavy metal contamination. Moreover, they are easy to collect and identify than micro-organisms (Begum et al., 2014). Lucadamo et al. (2008) further add that macroinvertebrates have relatively longer life cycles and are immobile than other groups. Since they possess wide range of sensitivity to pollution, using them for water quality investigations will provide an indication of the levels of pollution in a particular water resource based on the presence or absence of certain macroinvertebrates (Chikodzi et al., 2017).

• South African Scoring System (SASS)

South African Scoring System (SASS) is a biotic index developed by Chutter in 1998 (Dickens and Graham, 2002). This index is based on the presence of selected macroinvertebrates and their observed sensitivities to water quality variations (Chutter, 1998). SASS is modified from the Biological Monitoring Working Party (BMWP) scoring system, and has been subjected to several modifications over time resulting in the current South African Scoring System Version 5 (SASS5) (Chikodzi et al., 2017). SASS is an example of bio-assessment methods widely used across the world, with the United Kingdom being the first country to apply rapid biomonitoring method for river health assessment (Mbaruku, 2016). Several bio-assessment methods in the Southern African region were later developed based on the SASS and they were modified to include additional taxa found in the respective countries (Mbaruku, 2016). These methods are the Namibian Scoring System (NASS) in Namibia; the Okavango Assessment System (OKAS) in the Okavango Delta; the Zambia Invertebrate Scoring System (ZISS) in Zambia; and the Tanzanian Rivers Scoring System (TARISS) in Tanzania (Mbaruku, 2016).

Previous studies have adopted SASS and the above-mentioned country-specific scoring systems as part of their water quality assessments to investigate aquatic health. These methods are normally incorporated in water quality studies, in addition to physico-chemical methods, in order to conduct a comprehensive assessment and provide a better understanding the water’s aquatic health. For example, Palmer and Taylor (2004) investigated the macroinvertebrate communities using the Namibian Scoring System (NASS) in the Zambezi River, near Katima Mulilo, Namibia. NASS was modified from SASS to account for additional Namibian taxa that is not included in SASS (Palmer and Taylor, 2004).

Sampling was conducted in the upstream of Katima Mulilo. The results for this study showed that the scores are season-dependent, showing high scores during glow flow periods and low scores during high-flow periods (Palmer and Taylor, 2004). The sampling site also showed a high diversity in invertebrate taxa, with a total of 30 taxa (Palmer and Taylor, 2004). The average score per taxa (ASPT) was found to be 6.6—which indicated the abundance of sensitive taxa (Palmer and Taylor, 2004).

Similarly, in Tanzania, Mbaruku (2016) adopted the Tanzanian Rivers Scoring System (TARISS) to assess the health of Mugonya River, Kigoma. The study incorporated bioassessment of macroinvertebrates in addition to physico-chemical parameters assessment. Macroinvertebrates were collected through the method of kicking biotopes in the opposite direction of water flow to capture macroinvertebrates with the use of a net (mesh size 250 µm). The collected macroinvertebrates were then analysed using the TARISS method. The results based on the TARISS show that the highest average score per taxa (ASPT) of 5.1 was recorded at a site that is located midstream (S4), and the lowest ASPT of 0 was recorded at site S5 (also midstream). The TARISS results revealed that only S4 had fair water quality while the rest of the sampling sites depicted poor water quality (Mbaruku, 2016).

For SASS applications in water quality assessments, Chikodzi et al. (2017) conducted a study in Zimbabwe where they evaluate the health of Mucheke and Shagashe Rivers using SASS5. However, the study put more focus on biomonitoring (macroinvertebrates study) and used it as a primary determinant of water quality in the rivers. The results of biomonitoring were validated by comparing them with the tested physical, chemical and biological parameters. SASS5 techniques were used to sample and identify the biological communities in the river. For the upstream sites of Mucheke and Shagashe Rivers, SASS5 results indicated moderate pollution as a result of the observed presence of species moderately tolerant to pollution, and high pollution downstream due to the presence of pollution tolerant organisms (Chikodzi, et al., 2017).

Similarly, Walsh and Grobler (2016) also undertook SASS5 biomonitoring in their study on the Kaalspruit, where they sampled two locations along the Kaalspruit and on a tributary. The SASS 5 results indicate that the Kaalspruit and its one tributary are in poor conditions with the highest average score per taxa (ASPT) being 2 (Walsh and Grobler, 2016). It is further stated that all sites fell into the F ecological categories indicating that the river system is critically modified (Walsh and Grobler, 2016).

Finally, Fourie et al. (2014) aimed to investigate the effects of seasons on the abundance of macroinvertebrates and thus SASS5 scores in a study conducted in Skeerpoort River, South 31

Africa. Three sites were selected to conduct sampling during all four seasons (autumn, winter, spring and summer) (Fourie et al., 2014). Two-way analysis of variance (ANOVA) was used to for the comparison of SASS indices with the sites and seasons, and a one-way ANOVA was used to determine the effect of seasons on taxa (Fourie et al., 2014). The results on the effect of season on SASS scores revealed that there is no notable difference on the values of SASS scores between the seasons, but there is a notable difference between the three sites (Fourie et al., 2014). Therefore, the number of taxa was mostly affected by site location than by season (Fourie et al., 2014). The macroinvertebrate assemblages’ results, however, showed a relationship with both seasons and site. The results revealed that some taxa ware found at some sites or seasons than others (Fourie et al., 2014).

All the above-mentioned water quality assessment and monitoring techniques, including parameters to be monitored, should form part of a broader water quality management practice. The Australian Department of Water and Environmental Regulation (DWER) (2017) indicate that water quality assessment and monitoring are important aspects of water quality management, as information acquired from these assessments helps the country to manage water resources for the present and future (DWER, 2017).

2.4. WATER QUALITY MANAGEMENT

Water quality problems facing many countries, including South Africa, require an effective solution that will alleviate the adverse impacts likely to occur as a result of the problems not being addressed. Abbaspour (2011) is of the opinion that in order to achieve sustainable water resources, the quality of water resources must be suitable for their intended use while also giving allowance for them to be used and developed. This can be achieved through effective management, states Abbaspour (2011). Therefore, water quality management seeks to attain a balance between socio-economic development and environmental conservation through maintaining the fitness of water for use in a sustainable manner (Abbaspour, 2011). Practically, this management would include the following activities: pollution prevention, water treatment and restoration of ecosystems (Namugize and Jewitt, 2018). From a regulatory perspective, water quality management constitute the process of policy planning, development and administration as well as water use authorizations to activities that are likely to have adverse impacts on water quality (Neswiswi, 2014). Owing to the fact that most water quality impacts are from anthropogenic sources, water quality management involves controlling and managing various human activities that cause pollution and thus the degradation of water resources, both surface and groundwater (Neswiswi, 2014).

2.4.1. Integrated Water Resource Management

Integrated Water Resource Management (IWRM) is defined in the World Water Development Report as “a process that promotes the coordinated development and management of water, land and related resources in order to maximize the resultant economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems” (GWP, 2002). This implies that all the different uses of water resources are considered jointly. Duda and El-Ashry (2000) view IWRM as a shift from single-purpose to multi-purpose water projects. They opine that IWRM only focused on one purpose in the past and suggest a shift towards multi-purposes. According to the Global Water Partnership (2002) IWRM is generally concerned with water resource management, demand and supply, and further argue that the aim is to adopt multi-disciplinary and inter-disciplinary approaches to achieve sustainability in water usage. Dungumaro and Madulu (2003) argue that however IWRM is defined, there are key elements that cannot be missed from each of the definitions, and those elements are environmentally sound, equitable and sustainable way of using and developing water resources. The Dublin Conference on Water and Environment in 1992 identified six areas in which direct attention should be given in order to achieve effective IWRM. The six areas are as follows (UN, 1992):

• integrated water resources development and management, • water resources assessment, • protection of water resources, water quality, and aquatic ecosystems, • drinking water supply and sanitation, • water and sustainable urban development, and • water for sustainable food production and rural development.

The four Dublin principles on the management and sustainable use of water are also notable products of the conference (Day, 2009). Principle two in particular, promotes the need to adopt a participatory approach to water management; an approach that involves users, planners, and policy-makers at all levels (GWP, 2002). The Global Water Partnership (GWP) then adapted and expanded on these principles to show an international understanding of the equitable and efficient management and sustainable use of water (GWP, 2002). The GWP (2002) further proposed a three-pillar model for IWRM in order to achieve effective water resources management (Figure 2.5). This model promotes the following:

• moving towards an enabling environment of appropriate strategies; • policies for sustainable water resource development and management; • putting in place the institutional framework through which strategies, policies and legislation can be implemented; 33

• setting up the management instruments required by the institutions to do their job.

Figure 2.5: Three pillars concept for Integrated Water Resources Management by Global Water Partnership (redrawn by Day, 2009).

2.4.2. Community Based Water Resource Management (CBWRM) in IWRM

According to Chabalala (2017), the word “integrated” in integrated water resource management permits for the participation of various stakeholders which should have a common understanding and end goal of IWRM for the promotion of information interchange and assist in paralleling solutions to water problems with the available tools and resources. Local communities should also form part of the mentioned stakeholders permitted to participate in the management of water resources. Community-based water resource management (CBWRM) is an approach that embraces the principles of individual, household and community participation on issues that directly or indirectly affect their livelihoods and future (Tantoh and Simatele, 2017). This approach has shown to be a strategy that has taken many formats aimed at creating opportunities for communities to customize their processes of development (Tantoh and Simatele, 2017).

IWRM practices encourage water resource management practices to be decentralized and this process has been viewed as a medium for the reformation of management of land and water resources (Day, 2009). Moreover, amongst the principles of the Dublin conversion is the adoption of participatory approaches (Dungumaro and Madulu, 2003). Day (2009) asserts that although the importance of local community involvement is acknowledged by many scholars, the element of community-based management in IWRM is still lacking, particularly in developing countries (Day, 2009). Day (2009) further argues that water 34 reformers have disregarded community-based water management and customary water law because of their attempts to enforce broad ad vague concepts, which they often struggle to implement and manage. The traditional approach of IWRM often lacks decentralization and fails to involve stakeholders at local district levels for better water management (Day, 2009). For IWRM to be effective it needs to be compartmentalised and achieve a shift away from policies at national level to policies at regional or state level in order to achieve effective decentralization (Dungumaro and Madulu, 2003). This approach will therefore minimize certain challenges during the implementation stage and thus simplifying the complexity of the framework (Day, 2009).

The compartmentalization of the IWRM process will enable participating stakeholders to identify areas where their skills and resources can be utilized. This includes the local communities. Dungumaro and Madulu (2003) are in support of community engagement and are of the opinion that it is imperative to strengthen local community involvement for the identification of challenges they face and solutions to the problems. Therefore, the community’s full participation should be reiterated for effective water resources management to be realised.

Previous studies have documented case studies of community-based water resource management in order to present the role that it can potentially play in water resource management. Sirisena (2006) presents the case of the Kirindi Oya community-based irrigation settlement project (KOISP), Southern Sri Lanka. The Kirindi River has experienced drastic transforming since the erection of a dam in 1986 along the river (Sirisena, 2006). The system began to experience problems when the migration settlers inhabited the upstream portion of the river. The changes in demographics and land use negatively impacted the river and resulted in the decline of annual flow into the river and the dam (Sirisena, 2006). In the quest to find a resolution to the problem, the officials and the communities made a decision to collaborate, and a Project Management Committee (PMC) was formed; comprising of engineers, economists, sociologists, and senior community members with extensive experience in water issues (Sirisena, 2006). The aim of the committee was to formulate appropriate methodologies for the long-term improvement of the development plan, to be presented to governmental institutions. This committee was responsible for decision making, which involved the co-management of resources through sharing responsibility and authority between all stakeholders (Sirisena, 2006). The decisions made and included in the management plan included exploring rain water options for land preparation instead of using tap water; prioritise allocation of water and sanitation first, and other uses such as cultivation later (Sirisena, 2006). Another notable strategy that came from the plan is the “on and off mode” that allowed rotational supply of water between communities downstream and 35 upstream. On top of all the strategies and plans developed for the communities, training programmes were also conducted by non-governmental organizations (national and international) and these interventions changed the public’s perceptions and attitudes and encouraged them to be more disciplined and water efficient (Sirisena, 2006). The end results of this collaboration were positive which resulted stress relief for the water resources and ensured that water is used sustainably.

The water management project in the city of Cuttack in Orissa, India is another case depicting the management and protection of water resources by communities. Poricha and Dasgupta (2011) discuss the role that the community played in the water and sanitation project in Cuttack. The main goal of the project was to improve the livelihoods of the four, mainly impoverished, wards in the city of Cuttack (Poricha and Dasgupta, 2001). The communities had no access to formal water and sanitation systems and services, and the project was aimed at providing the communities with such services, and while doing so, empower women and the youth and achieve a cleaner environment. The participation of women was central to the project, and this is in line with principle 3 of the Dublin principles which assert that women should play a central role in the provision and management of water. Therefore, the community was organized into groups and the project plan was designed in a consensual manner with the aim of facilitating community participation in managing their own needs and strengthen self-governance (Poricha and Dasgupta, 2011). Project activities included digging new wells and improving existing ones through the introduction of low-cost technology which was effective in reducing iron content in the water and making it potable, as opposed to the water provided by government (Poricha and Dasgupta, 2011). Water filters were also designed and they are managed by the youth, and this also creates awareness and responsibility towards water structures by the communities. Finally, the wells were covered and paved on the sides to prevent immobility of overflow water. This framework was effective such that it empowered the community (including women and the youth) to pursue their own development and take responsibility and ownership of their own water resources (Poricha and Dasgupta, 2011). This created and solidified the relationship between the people and water resources, which leads to better management and maintenance of water resources.

In South Africa, Pollard and Cousins (2008) present the case of the Tsonga community managing the Baleni spring in Limpopo province, South Africa. The Baleni spring is a hot spring located near the Letaba River in Limpopo (Pollard and Cousins, 2008). Salt making activities take place during spring season, through filtering of salt from river water, and the placement of that salt on the fire to further remove water (Pollard and Cousins, 2008). The Tsonga community had a different and indirect way of managing and conserving the spring 36 and this is through the spiritual and cultural significance that the spring was given. Pollard and Cousins (2008) discuss that the Baleni area was considered a scared place, whereby cultural and religious worship activities took place. Spiritual practices and cultural and religious rituals were performed around the natural resource (Pollard and Cousins, 2008). Also, the salt-producing process was the responsibility of the women and the area was considered to have feminine energies, which limited access to and the use of the resources (Pollard and Cousins, 2008). This resulted in the spring being respected and due to the community’s beliefs, the resources were protected and not exploited. This further implies that the area was well managed and conserved.

These case studies have depicted how effective community-based water resources management can be when adopted appropriately. One of the main traits found to be common amongst the presented is that community-based water management is prevalent in rural areas and not in urban areas. This could largely owe to the fact that communities in urban areas do not obtain their water services directly from watercourse but from well- established and erected municipal water systems. On the contrary, many rural communities do not have established water supply systems and therefore obtain water directly from water resources such as rivers or underground water through wells. This notion is also supported by Day (2009) who notes that community-based water management widely involves management of water assets such as boreholes, handpumps as well as well as financial assets used to pay for water supply services. There is a dearth of literature based on urban community-based water management, which may be a signal indicating that such practices are rarely undertaken in urban areas. The documented case studies also highlight the importance of women and the youth in community-based water resource management, which honours the third Dublin Principle. The inclusion of professionals to form the management committee in addition to the community is imperative as it provides the element of professional advice to complement local and indigenous knowledge. This kind of professional personnel inclusion is what distinguishes the Kirindi Oya community of Sri Lanka from the Baleni community in Limpopo and the Indian Orissa community which solely relied on local personnel.

Although the documented case studies highlight the importance of community-based water resource management, is it however, imperative to note that this type of management, as with any management, is a manifestation of a solid management plan. Therefore, for the successful undertaking of such projects, an inclusive and comprehensive management plan should be developed and efficiently implemented.

CHAPTER 3

STUDY AREA AND METHODOLOGY

3.1. DESCRIPTION OF THE STUDY AREA

The study area is located in Gauteng, South Africa. The Kaalspruit flows through the township of Tembisa, as well as through the neighbourhoods of Olifantsfontein, Clayville and Ivory Park (Figure 3.1). A portion of the Kaalspruit is under the jurisdiction of Johannesburg Metropolitan Municipality (Ivory Park), and the rest of the study area lies within Ekurhuleni Metropolitan Municipality (Tembisa, Olifantsfontein and Clayville). The Kaalspruit forms part of the Quaternary Catchment A21B (Hennops catchment) (Walsh and Grobler, 2016). Following the merge of old Water Management Areas (WMAs) reducing the number from 16 WMAs to nine WMAs; the study area is now located in the Limpopo WMA, while it was previously found under the Crocodile (West) Marico WMA (Walsh and Grobler, 2016). The Kaalspruit flows from the south (running through the above-mentioned areas) to the north and forms a confluence with the Olifantspruit which further flows northward. Figure 3.2 shows the location of the Kaalspruit and the different land use activities surrounding the river.

Figure 3.1: Locality map of the Kaalspruit and the surrounding townships/suburbs. 38

Figure 3.2: Map showing the location of the Kaalspruit and Olifantspruit and the surrounding land cover within the study area.

3.1.1. Climate

The area is one of the regions in the country that have summer rainfall and experiences hot wet summers and cool dry winters (Ekurhuleni, 2004). Most of the rainfall in the region; about 80% to 90% of it, is characterized by heavy thunderstorms between the months of October and April (Ekurhuleni, 2004). The mean annual precipitation for the area ranges between 715 mm and 735 mm (Ekurhuleni, 2007). The area has also proven to have prevalent incidences of frost, which is mostly experienced for longer periods at areas of higher elevation (Ekurhuleni, 2004).

The warm season spans over a period of 6 months (from the 21st of September to the 21st of March), while the cool season lasts for 2.2 months (from the 30th of May to the 4th of August) 39

(Weather Spark, 2019). The mean average temperatures for the area ranges between 18°C and 20°C, with the minimum temperatures evident in July and maximum temperatures evident in January (Neswiswi, 2014). Average temperatures for the warm season are approximately 25.76°C with minimum temperatures averaging to 16.83°C; and winter temperatures averaging to 13°C with occasional visits to below freezing temperatures, and with minimum average temperatures of 5°C (Neswiswi, 2014). The area experiences northerly and north-westerly winds blowing during winter and spring seasons and during summer seasons it experiences north-easterly winds (Ekurhuleni, 2007).

3.1.2. Geology and Topography

Three main geological formations dominate the study area. Areas of granite-gneiss are located in Tembisa to the west of Clayville (Ekurhuleni, 2007). Quartzites of the Transvaal Supergroup dominate large areas of Tembisa, with granite also covering notable portions of the west of Tembisa (including Ivory Park), through to the west of Clayville. Olifantsfontein and Clayville are dominated by dolomite formations which cover approximately 90% of the area (Ekurhuleni, 2007). Dolomitic areas are susceptible to sinkhole formations, particularly in areas where there exist high levels of underground extraction from mining activities (Ekurhuleni, 2007). Clayville and Olifantsfontein are underlain by similar dolomitic formations as Centurion, which is close in location to these areas and has experienced sinkhole problems for many years. Therefore, there may be a likelihood that these areas may experience sinkhole problems.

The study area can generally be regarded as flat but contains a small number of outstanding topographical features (Ekurhuleni, 2007). The study area and the surrounding townships specifically, are characterised by undulating plains with pans (Ekurhuleni, 2007). The study area has an elevation that ranges between 1471 masl to 1627 masl (Floodmap, 2018).

3.1.3. Vegetation and land use

The vegetation type in which the study area falls within is the Grassland Biome, with a large dominance of grass and great abundance of geophytes (Ekurhuleni, 2007). Trees are not found in abundance as their establishment is normally restricted by veld fires and grazing, and their occurrence is mostly in scattered clusters. The two main vegetation sub-types found in the area are the Carletonville Dolomite Grassland and the Egoli Granite Grassland (Ekurhuleni, 2007). The remaining part of the study area, which constitutes a greater portion of the area, is altered or urban as result of cultivation or settlements.

The study area has undergone immense development. It is characterised by urbanized suburban areas and townships as well as industrial areas (Ekurhuleni, 2004). The southern part of the area is densely populated with the presence of formal and informal settlements, while the northern part of the area is heavily industrialised with the presence of formal houses. Tembisa and Ivory townships are mostly characterised by residential areas and businesses/commercial/services spaces (Ekurhuleni, 2014). On the other hand, Clayville and Olifantsfontein areas are dominated by industrial spaces located close to residential areas (Ekurhuleni, 2014). Additionally, there is a notable presence of open spaces and agriculture land used for subsistence and commercial farming (particularly in the northern part of the study area–Clayville and Olifantsfontein), and the areas are considered to have high agriculture potential (Ekurhuleni, 2007). These mentioned land use activities such as settlements, industries and agriculture are reported to be the major contributors of pollution in the Kaalspruit and Olifantspruit (Nawn, 2004; Batt, 2015; Walsh and Grobler, 2016).

3.1.4. Population and settlement pattern

The total population of the study area, combining the populations of Ivory Park, Tembisa, Clayville and Olifantsfontein is approximately 661, 117 inhabitants (StatsSA, 2011). The dominant population group in all the areas is the black population with an average of 98.9% in Ivory Park, Tembisa and Clayville and approximately 64.5% in Olifantsfontein (StatsSA, 2011). The remainder of the population is comprised of white people, Indians and coloureds. In terms of population density: Tembisa has a population density of 11, 000 per km2 (total area of 42.80 Km2; Ivory with 20, 000 per Km2 (total area of 9.21 Km2); Clayville with 1 034 per Km2 (total area of 14.05 Km2); and Olifantsfontein with 354.39 Km2 (total area of 0.28 Km2) (StatsSA, 2011).

The study area is generally characterized by dense settlements. Tembisa and Ivory Park are classified as townships mostly dominated by low-income settlements (Ekurhuleni, 2007). The types of settlements present in the two townships are both formal and informal. There are currently over ten informal settlements that can be located in Tembisa and Ivory Park combined. The townships are largely dominated by government-provided stands and houses from the Reconstruction and Development Programme (RDP). There is also a notable proportion of bond-housing in the areas. Tembisa and Ivory Park are generally poorly serviced, particularly in informal settlements, which create major environmental challenges and also contribute to the poor state of the river (Neswiswi, 2014). Clayville and Olifantsfontein are different from the two townships in that they are comprised of middle- income to high-income settlements, with Olifantsfontein possessing more of high-end

41 settlements that Clayville. Moreover, the settlement pattern is also less dense than in Tembisa and Ivory Park (Ekurhuleni, 2007).

3.2. METHODOLOGY

3.2.1. Field survey and site location

A site visit was conducted on the 6th of April 2018 to select sites based on accessibility, safety, and representative sample points. Following the field survey, five sites were selected for sampling (S1, S2, S3, S3, S4, S5) (Table 3.1 and Figure 3.3). The sites were selected from upstream of the river course to downstream, with site one located upstream and site five located downstream. However, site 5 (S5) is not part of the Kaalspruit but part of the Olifantspruit which is located following the confluence between of the Kaalspruit and the northern Olifantspruit. This site was selected in order to discern the impacts of the upstream sites to downstream locations. Moreover, there exists a tributary between site 1 and site 3 which forms a confluence with the Kaalspruit (Figure 3.3). Two sampling trips were later undertaken for high flow season (September 2018) and low flow season (June 2019).

The selected sampling sites displayed varying levels of stream flows. Sites 1 and 2 had stagnant to very slow-flowing waters, while site 3 was characterised by slow-flowing waters. Finally, sites 4 and 5 had medium-flowing waters.

Table 3.1: Coordinates of the selected sampling points and the respective locations.

Site Location Coordinates Y X Site 1 Tembisa township, upstream -26.011694 28.200107

Site 2 Ivory Park township, Freedom Drive -25.99828 28.195047

Site 3 Ivory Park township, Riverside Street -25.984798 28.195355

Site 4 Clayville, Porcelain Rd. -25.951698 28.207383

Site 5 Olifantsfontein, downstream -25.922468 28.227421

Figure 3.3: Map showing the study area and selected sampling points, and the location of the study area in the context of Gauteng Province in South Africa.

3.2.2. Water quality analysis

The temperature, pH, total dissolved solids (TDS), electrical conductivity (EC), and dissolved oxygen (DO) were measured in-situ using a pre-calibrated Eutech ECPHWP45002K multi- parameter water quality meter (Table 3.2). The other parameters, namely nitrate, nitrite, total phosphates, chlorophyll-a, faecal coliform bacteria, E. coli, various metals, and organic compounds (SVOCs, OCPs, PCBs and phenols) (Table 3.3) were analysed at Waterlab and UIS Organic laboratories which are accredited by the South African National Accreditation System (SANAS). The concentrations of the metals were determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) following US EPA methods. Water collection methods

43 included the collection of water samples in 1.5 L sterile plastic bottles. The bottles were rinsed with river water before sampling and sampling was undertaken with the bottles facing upstream, with care taken to avoid collecting any sediment. The water bottles were labelled according to site numbers and some of them were wrapped in aluminium foil to protect them from light. The samples were stored in a cooler box filled with ice to keep them cool during transportation and were transferred to the laboratory after sampling. According to DWAF (1996b), dissolved oxygen concentration must be measured as the instantaneous concentration at 06h00 in the morning. However, due to the questionable safety of the area, the measurements of in-situ parameters (including DO) and the collection of water and sediment samples for all sites commenced in the morning at 9h00 and were concluded after noon, beginning at site 1 and finishing at site 5.

Table 3.2: In-situ water quality parameters measure in the field for all sampling sites.

In situ parameters Abbreviation Unit pH pH

Total Dissolved Solids (TDS) TDS Mg/L

Electrical Conductivity EC µS/cm

Temperature T °C

Dissolved Oxygen DO %

Table 3.3: Water quality parameters measured in the lab for the respective sampling sites.

Parameter Abbreviation/Symbol Unit

Inorganic

Nitrate and nitrite N mg/L

Total Phosphates P mg/L

Organic

Phenols Phenol µg/L

Organochlorine Pesticides OCPs µg/L

Polychlorinated Pesticides PCBs µg/L

Semi-Volatile Organic Compounds SVOCs µg/L

Chlorophyll-a µg/L

Microbiological

Escherichia coli E. coli CFU/100 mL

Faecal coliform Faecal coliform CFU/100 mL 44

Parameter Abbreviation/symbol Unit

Metals

Various metals Al, Ba, Cr, Ca, Cu, Fe, K, Mg, Mn, Na, mg/L P, Si, Zn.

The obtained water quality results (including physico-chemical parameters, nutrient concentrations and metals) were compared to Target Water Quality Ranges (TWQRs) for freshwater ecosystems (DWAF, 1996b) and benchmark criteria assembled by Kotze (2002) developed from the TWQRs (DWAF, 1996b) and water quality guidelines by Rand Water (1998) (Table 3.4, 3.5 and 3.6).

Table 3.4: Classification of trophic status for aquatic ecosystems (DWAF, 1996b).

Parameter Unit Oligotrophic Mesotrophic Eutrophic Hypertrophic

N (inorganic) mg/L <0.5 0.5 - 2.5 2.5 - 10 >10

N:P 40 25 20 10

PO4 mg/L <5 5.0 – 25.0 25 - 250 >250 (inorganic)

Table 3.5: Target Water Quality Range (TWQR) values with chronic (CEV) and acute effect values (AEV) (DWAF, 1996b).

Parameter Unit Criteria TWQR CEV1 AEV2

Al mg/L pH<6.5 0.005 0.01 0.1

pH>6.5 0.01 0.02 0.15

As mg/L - 0.01 0.02 0.13

Cd mg/L CaCO3<60mg/L 0.00015 0.0003 0.003

Cr (3) mg/L - 0.012 0.024 0.34

Cr (6) mg/L - 0.007 0.014 0.2

Cu mg/L CaCO3<60mg/L 0.0003 0.00053 0.0016

Fe mg/L The Iron concentration should not be allowed to vary by more than 10% of the background dissolved iron concentration for a particular site or case, at a specific time. Mn mg/L - 0.18 0.31 1.3

Se mg/L - 0.002 0.005 0.03

Hg mg/L - 0.00004 0.00008 0.0017

Zn mg/L 0.002 0.0036 0.036

1CEV = is defined as “that concentration or level of a constituent at which there is expected to be a significant probability of measurable chronic effects to up to 5 % of the species in the aquatic community” (DWAF, 1996). 2AEV= is defined as “that concentration or level of a constituent above which there is expected to be a significant probability of acute toxic effects to up to 5 % of the species in the aquatic community” (DWAF, 1996).

Table 3.6: Reference criteria for Ideal, Tolerable, and Intolerable values for major ions (Kotze, 2002).

Parameters Unit Ideal mg/L Tolerable mg/L Intolerable mg/L pH 6.5 - 8.5 5 - 6.5 and 8.5 - 9 <5 - >9

EC µS/cm 450* 1000* >1000*

DO mg/L 80 - 120 % 60 – 80 % >40 %

Ca mg/L 150 >150

Cl mg/L 50 150 >150

Mg mg/L 70 >70

K mg/L 50 400 >400

Na mg/L 50 100 >100

3.2.3. Sediment assessment

In-stream sediment sampling was conducted the same time as water sampling (September 2018 and June 2019). Sediment samples for each site were collected using glass jars, which were labelled according to site numbers post-sampling, and then wrapped in aluminium foil so as to protect them from light. Some of the jar samples were sent to SANAS accredited Waterlab laboratory to for metal analysis, while other samples were sent to SANAS accredited UIS organic laboratory for analysis of organic compounds (PCBs, OCPs, Phenols and SVOCs) (Table 3.7). The sediment samples were analysed at the laboratory by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Other sediment samples were collected in Ziplock plastic bags, labelled accordingly and kept in the freezer at -18 °C so as to be used for physical analysis (moisture and organic content determination).

Table 3.7: Organic compounds measured in sediment samples for respective sampling sites.

Parameters Abbreviation/Symbol Unit

Organic compounds

Phenols Phenol μg/kg

Organochlorine Pesticides OCPs μg/kg

Polychlorinated Pesticides PCBs μg/kg

Semi-Volatile Organic Compounds SVOCs μg/kg

The ASTM (2001) standard method for sediment analysis was followed for the determination of moisture and organic content in the sampled sediment. Moisture and organic content analyses were conducted in the Ecotoxicology lab at the University of Johannesburg. The sediment was kept frozen before analysis and was thawed one day before. For the determination of moisture content for each site; approximately 300 g of sediment was dried in the oven at a temperature of 60°C for four (4) days. The weight of dry sediment was measured and the difference between the weight of dry sediment and wet sediment was calculated to work out the percentage moisture.

A specified amount of dry sediment for each site was later incinerated to determine the organic content in the sediment. The dry sediment was put into the incinerator and left overnight at a temperature of 600°C. The burnt sediment was weighed and the difference in weight between dry sediment and burnt sediment was calculated in order to determine the amount and therefore percentage of organic content in the sediment. The remainder of dry sediment (100 g each) was placed in the Star Screens test sieve in order to determine the grain sizes of the samples. The sieve was comprised of five compartments representing grain sizes ranging from 53 µm – 4000 µm. The sieve grain size categories are the ones widely used to categorize sediment grain sizes (Table 3.8).

Table 3.8: Grain size categories (Cyrus et al., 2000)

Category Size Gravel >4 000 µm Very coarse sand 4 000 – 2 000 µm Coarse sand 2 000 – 500 µm Medium sand 500 µm – 212 µm Very fine sand 212 µm – 53 µm Mud <53 µm

The physical characteristics of sediments were compared to USEPA (1991) and the sediment grain sizes was analysed using grain size categories by Cyrus et al. (2000) (Table 3.7). Metals and chemical compounds results were compared to the Canadian Environmental Quality Guidelines for sediment (2001) (Table 3.9). The Canadian guidelines were used as there are currently no sediment quality guidelines in South Africa.

Table 3.9: Reference criteria showing category ranges for chemical constituents in sediment according to the Canadian Environmental Quality Guidelines for sediment (2001).

Range/category Description A Ideal/below ISQGs Minimal effect range where adverse effects rarely occur. B Above ISQG and below PELs Possible effect range where adverse effects occasionally occur. C Above PELs Probable effect range where adverse effects frequently occur. *ISQG = Interim sediment quality guidelines

*PEL = Probable effect level.

3.2.4. Macroinvertebrate assessment

South African Scoring System version 5 (SASS5)

SASS5 sampling method (Dickens and Graham, 2002) was adopted for the collection of macroinvertebrate assemblages. Macroinvertebrate sampling was conducted in tandem with water and sediment sampling (September 2018 and June 2019). However, SASS5 was only conducted at sites one, two and three (S1, S2, and S3) as water was flowing in the specified three sites, whereas, in sites four and five water was stagnant and SASS5 is not applicable to stagnant waters (Dickens and Graham, 2002). Macroinvertebrate assemblages were collected in three habitats (also known as biotopes) per site as per the SASS5 protocol: Vegetation (marginal or in-stream); Stones in current (SIC) or bedrock; and gravel, sand, and mud (GSM). A net of 1 mm mesh and 30 cm by 30 cm frame was used to capture the sampled macroinvertebrates. Sampling was conducted by kicking SIC for approximately two minutes and using the net to collect the released macroinvertebrates from the SIC biotope. Collection in the GSM biotope was also conducted by kicking the respective areas for approximately one minute to also allow for the capturing of macroinvertebrates. Finally, macroinvertebrates in the vegetation biotope were sampled by pushing the net vigorously into the vegetation with a length of approximately two metres for order to capture the released macroinvertebrates into the net.

The captured assemblages were placed in a tray and were identified in the field to family level using the scoring sheet. The SASS score and average score per taxa (ASPT) were calculated by use of the sensitivity scores for each sampled site. The macroinvertebrates were released back into the water upon completion of identification for each biotope.

The SASS scores and ASPT were used to determine the Highveld biological bands for the sites as provided by Dallas (2007) (Figure 3.4), and a class for each site was established. Moreover, the results were used to place each site in the respective ecological categories (Table 3.10).

Figure 3.4: Biological bands for SASS5 classification in the Upper Highlands (Dallas, 2007).

Table 3.10: Ecological categories for SASS5 classification (Dallas, 2007).

Category Description A Natural Unmodified natural B Good Largely natural with few modifications C Fair Moderately modified D Poor Largely modified E Seriously modified Seriously modified F Critically modified Critically or extremely modified

3.2.5. Habitat assessment

Integrated Habitat Assessment System

The Integrated Habitat Assessment System (IHAS) method (McMillan, 1998) was adopted in order to conduct a habitat assessment for the selected sites. IHAS was designed to complement the bioassessment studies (such as SASS) by providing information on the physical habitat of a site that would possibly provide an explanation to the biological assessment results attained for that particular site (Ollis et al., 2006). IHAS was conceived with the understanding that the availability and quality of macroinvertebrate habitat available at a site can greatly affect the SASS results, which implies the need for a supplementary macroinvertebrate habitat assessment (Chutter, 1998). Therefore, IHAS aims to abstract the quality and quantity of habitats available tom macroinvertebrates at a sampling site (McMillan, 1998).

Site habitat assessment was undertaken in accordance with IHAS protocol in order to complete information on sampling habitat (stones in current, vegetation, and other habitat including gravel, sand, and mud and stones out of current) and stream condition sections. Stream conditions assessment comprised of a site evaluation in terms of physical characteristics and the level of destruction to the site. The IHAS score sheet was completed with the necessary information. The total IHAS score is 100 which is a sum of habitat total (55 points) and stream condition total (45 points).

The total IHAS scores for each site were calculated and classified according to habitat conditions categories as presented by McMillan (1998). A percentage is given according to the rating given to each biotope. Percentage categories are presented in Table 3.11.

Table 3.11: IHAS classes as indicated by scores and description (McMillan, 1998).

IHAS score Description Class >75 Very good A 65 – 74 Good B 55 – 64 Fair/Adequate C <55 Poor D

CHAPTER 4 RESULTS AND ANALYSIS

4.1. River site description

This section presents information about the condition of the river with respect to the sampling sites. Information on the channel conditions, flow characteristics and general site conditions is provided for each site.

Site 1

Site 1 is the upstream site of the study area and is located within the township of Tembisa. This site was selected in order show water quality conditions upstream of the river in comparison to midstream and downstream sites. Water is stagnant and the riparian vegetation is grass and is not in abundance. There is a bridge present that is crossing the river at this site. The bridge is being reconstructed, which resulted in a deposition of sand into the river to direct water flow according to construction requirements (Figure 4.1). Commercial brickmaking and sand gathering activities by individuals are taking place on the side of the river in order to be sold to the communities.

B A

Figure 4.1: Stream conditions at sampling site 1 of the Kaalspruit (Tembisa).

Site 2

Site 2 is situated downstream of site 1. The water is stagnant and opaque with a brownish/greenish colour and there is also a poor abundance of riparian vegetation. Waste (household, building, and general waste) is disposed of inside the water as well as on the sides of the river. There is bridge that crosses the river (North of the river) with some parts of the bridge’s support erected in-stream. There are also a number of informal settlements located on the sides of the river (Figure 4.2).

B C

Figure 4.2: Stream conditions at sampling site 2 of the Kaalspruit (Ivory Park, Freedom Drive).

Site 3

Site 3 is situated downstream of site 2 and is considered as the study’s midstream site. The water is shallow and opaque, with in-stream boulders as well as boulders located on the sides of the river. Waste was observed disposed inside the river and on the river bed. A road crosses the river creating a bridge with in-stream support. There is a presence of informal settlements located on the banks. A toilet drainage pipe was observed coming from the informal settlements and draining sewage into the river (Figure 4.3).

B C

Figure 4.3: Stream conditions and activities at sampling site 3 of the Kaalspruit (Ivory Park, Riverside Street).

Site 4

Site 4 is situated further downstream from site 3. The water is opaque and greenish- brownish in colour. There is a bridge erected which crosses the river and is also used as a road, and the presence of gabions adjacent to the bridge. There was a disposal of waste (mostly clothes) observed within the river and on the sides of the river. Other activities observed on-site include farming, sand collection within the river and the burning of vegetation on the banks of the river (Figure 4.4).

A B

Figure 4.4: Stream conditions and riverbank activities at sampling site 4 of the Kaalspruit (Clayville).

Site 5

Site 5 is situated on the northern Olifantspruit following the confluence between the Olifantspruit and the Kaalspruit. This site was selected in order to investigate pollutants discovered in the Olifantspruit in comparison to the pollutants observed in the Kaalspruit. This is due to the fact that the Kaalspruit joins the Olifantspruit, therefore an investigation on how the Kaalspruit impacts the Olifantspruit was necessary. The flow of water at site 5 was medium with the river floor dominated by bedrock. The water was discoloured. Waste was observed on the sides of the river. Farming is the dominant activity taking place on the river banks. There was also burning of vegetation observed on the site (Figure 4.5).

B C

Figure 4.5: Stream conditions and riverbank activities at sampling site 5 of the Olifantspruit (Olifantsfontein).

Table 4.1 provides further details on the previously discussed sampling sites in order to provide further understanding of the respective sampling sites.

Table 4.1: Sampling sites description as assessed on the Kaalspruit.

Variable Site 1 Site 2 Site 3 Site 4 Site 5 Hydrological type Perennial Perennial Perennial Perennial Perennial

Channel morphology Alluvial, containing Alluvial, containing Alluvial, containing Alluvial, containing sand Alluvial, containing mostly mud. gravel, sand, mud and gravel, sand, mud and gravel and mud. bedrock with gravel, sand bedrock. bedrock. and mud in limited amounts. Canopy cover Open Open Open Open Open

Substrate composition Dominated by mud Dominated by gravel Dominated by gravel Dominated by gravel and Dominated by bedrock, and sand. and sand with mud and sand with mud and sand, with mud available. with gravel, sand and mud and bedrock present. bedrock present in limited amounts.

Flow characterisation Stagnant to very slow Stagnant to very slow Slow velocity flow with Medium velocity flow and Medium velocity flow and flow velocity flow velocity. medium depth. medium depth. medium depth.

4.2. WATER QUALITY RESULTS

4.2.1. Physico-chemical water analyses

Water quality results for the Kaalspruit for wet and dry seasons are presented in this chapter. This section presents results for in-situ water quality parameters and laboratory analysis. pH values for both wet and dry seasons (September 2018 and June 2019 respectively) indicated both acidity and alkalinity. For the wet season, the lowest pH value measured is 5.75 which was measured at site 5 while the highest pH value recorded is 7.89 measured at site 3 (Table 4.2). For the dry season, the pH values indicated both acidity and alkalinity; however, the results showed to be less acidic and alkaline than the wet season results (Table 4.3). The lowest pH value was measured at site 2 with the value of 6.85 while the highest value was measured at site 4 with the value of 7.51. pH values for both wet and dry seasons all fell within tolerable limits.

Electrical Conductivity (EC) values for both seasons all appeared to be within tolerable limits. Values for the wet season ranged widely between 662.2 µS/cm and 912.9 µS/cm with the lowest value observed at site 4 and the highest value observed at site 2. For the dry season the EC values ranged widely between 627.0 µS/cm and 734 µS/cm with the lowest reading observed at site 1 and the highest reading observed at site 5. Total Dissolved Solids (TDS) values for the wet season ranged between 330 mg/L to 439.4 mg/L. Site 4 showed the lowest TDS value while site 2 showed the highest value for TDS. For the dry season, the lowest TDS value recorded was 312.8 mg/L measured at site 1 while the highest TDS value is 372.8 mg/L observed at site 5.

Temperature readings for the wet season ranged between 8.03°C and 22.8°C with the lowest reading observed at site 4 and the highest reading observed at site 2. Site 2 showed great variation from the rest of the sites as all the other sites were over 20°C while site 2 showed a reading of 8.09°C. For the dry season, the temperature results were notably lower than the wet season whereby all were below 20°C. The lowest reading was observed at site 1 with 12.2°C and the highest value was observed at site 2 with 16.6°C. Dissolved oxygen (DO) results have shown intolerable levels and all of the readings were below the minimum allowable values. Site 1 revealed to have the lowest DO concentration and percentage saturation (2.1 mg/L and 22%) while site 3 revealed to have the highest (5.84 mg/L and 59%) for the wet season. Similarly, DO readings and percentage saturation appeared to be low at site 1 (1.15 mg/L and 12.3%) and high at site 3 (6.59 mg/L and 67.5%). Site 3

however, has recorded values which are slightly beyond the minimum target values for DO limits.

Table 4.2: In-situ water quality parameters measured for the Kaalspruit during the wet season (September 2018). Parameter values were compared to benchmark criteria by Kotze (2002).

Parameter

Sampling TDS EC Temperature DO Oxygen pH site (mg/L) (µS/cm) (°C) (mg/L) saturation (%) Site 1 7.84 420.1* 838.4 21.5* 0.7 8 Site 2 6.41 439.4* 912.9 22.8* 2.1 22 Site 3 7.89 380.4* 761.5 21.8* 5.84 59 Site 4 6.53 330.1* 662.2 8.03* 2.0 21 Site 5 5.75 438.7* 884.8 20.07* 5.75 58 Ideal/within TWQR Tolerable Intolerable * Not classified

Table 4.3: In-situ water quality parameters measured for the Kaalspruit during the dry season (June 2019). Parameter values were compared to benchmark criteria by Kotze (2002).

Parameter

Sampling TDS EC Temperature DO Oxygen pH site (mg/L) (µS/cm) (°C) (mg/L) saturation (%) Site 1 6.99 312.8* 627 12.2* 1.15 12.3 Site 2 6.85 318.7* 637.2 16.6* 2.91 29.9 Site 3 7.23 364.6* 723.3 15.5* 6.59 67.5 Site 4 7.51 346.4* 692 14.4* 2.57 29.3 Site 5 7.14 372.8* 734 15.4* 6.45 65.01 Ideal/within TWQR Tolerable

Intolerable * Not classified

4.2.2. Nutrients and microbial analyses

Results for the wet season (Table 4.4) indicated that nitrate levels ranged between 0.1 mg/L (measured at sites 1, 2, 3 and 4) and 0.5 mg/L measured at site 5. Nitrite levels for sites 1, 2, 3 and 4 were below detectable levels of <0.05 mg/L while at site 5 they were at 0.2 mg/L. For the dry season, the results revealed that nitrate values for all sites were below detectable limits all at <0.1 mg/L (Table 4.5). While nitrite results showed that the lowest values were measured at sites 2 and 3 at values below detectable levels (<0.05 mg/L) and the highest values measured at sites 1, 4, and 5 all at 0.06 mg/L. Total Phosphate values for the wet season were the lowest at site 4 with the value of 2.3 mg/L and the highest at site 2 with the recorded value of 4.2 mg/L. While for the dry season total phosphate values ranged between 1.3 mg/L measured at site 1 and 3.0 mg/L measured at site 3. The nitrogen:phosphate (N:P) ratio for all the sites from both wet and dry seasons revealed that all sites were hypertrophic. The highest calculated N:P ratio was identified at site 5 (0.2) during the dry season, and the rest of the values are below 0.1 for all sites and both seasons.

Chlorophyll-a results for the wet season sampling revealed that site 5 measured below detectable levels with <1 µg/L while site 3 was the highest with the recorded levels of 55 µg/L. For the dry season, Chlorophyll-a results were the lowest with below detectable values (<1 µg/L) at sites 2 and 4 and were the highest at site 5 (17 µg/L). Moreover, faecal coliform bacteria values for the wet season ranged between 5600 CFU/100 mL recorded at site 5 to above detectable limits of >100 000 CFU/100 mL recorded at sites 2 and 3. While for the dry season, faecal coliform bacteria was the lowest at site 1 (3 400 CFU/100 mL) and the highest with beyond detectable limits at sites 2, 4 and 5 (>100 000 CFU/100 mL). The wet season values for E. coli showed a similar trend to faecal coliform bacteria by registering the lowest value (5 500 CFU/100 mL) at site 5 and the highest values that are beyond detectable limits (>100 000 CFU/100 mL) at sites 2 and 3. While for the dry season, E. coli results have shown the lowest value at site 1 (2 200 CFU/100 mL) and recorded the highest values beyond detectable limits at sites 2 and 4 (>100 000 CFU/100 mL).

Table 4.4: Nutrients and microbial organisms measured for the Kaalspruit during the wet season sampling (September 2018). N:P ratio was compared with the DWAF (1996b) Guidelines.

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Nitrate mg/L 0.1 0.1 0.1 0.1 0.5 Nitrite mg/L <0.05 <0.05 <0.05 <0.05 0.2 Total Phosphate mg/L 3.5 4.2 3.4 2.3 3.2 N:P Ratio 0.04 0.04 0.04 0.06 0.2 Chlorophyll-a µg/L 29 42 55 2 <1 Faecal Coliform CFU/100 mL 73 000 >100 000 >100 000 73 000 5 600 Bacteria Escherichia coli CFU/100 mL 69 000 >100 000 >100 000 61 000 5 500 Hypertrophic

Table 4.5: Nutrients and microbial organisms measured for the Kaalspruit during the dry season sampling (June 2019). N:P ratio was compared with the DWAF (1996b) Guidelines.

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Nitrate mg/L <0.1 <0.1 <0.1 <0.1 <0.1 Nitrite mg/L 0.06 <0.05 <0.05 0.06 0.06 Total Phosphate mg/L 1.3 1.9 3.0 2.0 2.7 N:P Ratio 0.1 0.07 0.05 0.08 0.06 Chlorophyll-a µg/L 11 <1 3 <1 17 Faecal Coliform CFU/100 mL 3 400 >100 000 28 000 >100 000 >100 000 Bacteria Escherichia coli CFU/100 mL 2 200 >100 000 20 000 >100 000 92 000 Hypertrophic

4.2.3. Metal analyses

Results for metals in the wet season (Table 4.6) have shown that Calcium (Ca) levels were relatively low and largely below ideal target water quality range (TWQR), with the lowest at 35 mg/L measured at site 5 and the highest being 48 mg/L measured at site 2. Potassium (K) values ranged between 7.9 mg/L measured at site 4 and 16.6 mg/L measured at site 5, which are both greatly lower than Ideal TWQR. For Magnesium (Mg), the lowest recorded value was at site 1 at 12 mg/L and the highest was measured at site 4 at 22mg/L, which are largely below TWQRs. Sodium (Na) values were relatively higher and ranged between 42 mg/L measured at site 4 and 89 mg/L measured at site 2 which falls between ideal and tolerable TWQRs. Aluminium (Al) levels were the lowest at site 1 with 0.109 mg/L and the highest at site 4 with 0.374 mg/L, and they were classified to fall between chronic effect values and acute effect values. Iron (Fe) values ranged between 0.695 mg/L (site 5) and 2.21 mg/L (site 3). The lowest Manganese (Mn) value recorded was 0.322 mg/L (site 5) and the highest recorded value was 0.759 mg/L at site 3. Moreover, the lowest values for Phosphorus (P) was measured at site 4 (1.19 mg/L) and the highest was measured at site 2 (2.78 mg/L). Silicon (Si) values ranged between 8.1 mg/L (site 5) and 11.4 mg/L (site 4). Finally, the lowest value for Zinc (Zn) was measured at site 1 (0.024 mg/L) and the highest value was measured at site 4 (0.04 mg/L). All the other remaining ions and metals that were measured including Copper, Lead, Cadmium, and Chromium possessed values below detectable levels (< 0.010 mg/L).

The dry season results (Table 4.7) also showed Calcium (Ca) levels to be largely lower than ideal TWQR, and the lowest Calcium levels were slightly lower than in the wet season with recorded measurements of 33 mg/L (site 3) and the highest was similar to the wet season at 48 mg/L (site 4). Potassium (K) levels ranged between 8.4 mg/L (site 1) and 17.7 mg/L (site 5), which were largely below ideal TWQR. Magnesium (Mg) levels were also largely below TWQR and they ranged between 10 mg/L (site 3) and 20 mg/L (site 4). Moreover, the lowest value for Sodium (Na) was recorded at site 3 (44 mg/L) and the highest recorded at site 5 (88 mg/L) which fall between tolerable and ideal TWQRs. Aluminium levels were high and fell between chronic effect values and acute effect values, with values that ranged between 0.120 mg/L (site 1) and 0.281 mg/L (site 5). For Iron (Fe), the lowest recorded value was 0.419 mg/L (site 5) and the highest value was 0.990 mg/L (site 2). Manganese (Mn) values showed a range of 0.277 mg/L measured at site 5 and 0.518 mg/L measured at site 4, with all the values being in the chronic effect values range. For Phosphorus (P), the lowest value recorded was 0.621 mg/L measured at site 1 and the highest value was 2.49 mg/L measured at site 3. Silicon values ranged between 6.5 mg/L at site 3 and 14.1 mg/L measured at site 4. Finally, Zinc (Zn) values ranged between 0.022 mg/L (site 1) and 0.088 61

mg/L (site 5) and were between chronic effect values and acute effect values. All the other remaining ions and metals that were measured including Copper (Cu), Lead (Pb), Cadmium (Cd), and Chromium (Cr) possessed values below detectable levels (< 0.010 mg/L).

Table 4.6: Metals measured in the Kaalspruit water during wet season sampling (September 2018). Values were compared with Target Water Quality Guidelines by DWAF (1996b).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Al mg/L 0.109 0.263 0.197 0.374 0.263 Ba mg/L 0.133 0.137 0.132 0.072 0.058 Ca mg/L 43 48 45 47 35 Fe mg/L 1.54 1.96 2.21 0.719 0.695 K mg/L 15.5 16.8 14.8 7.9 16.6 Mg mg/L 12 14 13 22 13 Mn mg/L 0.610 0.740 0.759 0.601 0.322 Na mg/L 86 89 73 42 84 P mg/L 1.72 2.78 1.61 1.19 1.20 Si mg/L 10.5 10.5 9.8 11.4 8.1 Sr mg/L 0.093 0.086 0.099 0.066 0.062 Ti mg/L 0.042 0.036 0.037 0.022 0.026 Zn mg/L 0.024 0.211 0.038 0.041 0.039 Unclassified Ideal/TWQR Tolerable

Intolerable/CEV Above AEV

Table 4.7: Metals measured in the Kaalspruit water during dry season sampling (June 2019). Values were compared with Target Water Quality Guidelines by DWAF (1996b).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Al mg/L 0.120 0.168 0.143 0.197 0.281 B mg/L 0.011 0.014 0.021 <0.010 <0.010 Ba mg/L 0.075 0.072 0.052 0.049 0.049 Ca mg/L 41 40 33 48 41 Fe mg/L 1.00 0.990 0.709 0.618 0.419 K mg/L 8.4 9.8 10.6 9.8 17.7 Mg mg/L 11 11 10 20 14 Mn mg/L 0.506 0.497 0.389 0.518 0.277 Na mg/L 52 55 44 56 88 P mg/L 0.621 0.998 2.49 0.973 1.53 Si mg/L 11.1 10.7 6.5 14.1 12.2 Sr mg/L 0.132 0.124 0.125 0.085 0.074 Zn mg/L 0.022 0.038 0.042 0.038 0.088 Unclassified Ideal/TWQR Tolerable Intolerable/Above CEV Above AEV

4.2.4. Organic compounds analyses

Wet season results for the tested organic compounds revealed the presence of such compounds in minimal amounts, with majority of the compounds measuring below detectable levels.

Dichlorodiphenyl trichloroethane (DDT) and its metabolites (DDD and DDE) as examples of Organochlorine pesticides (OCPs) have shown to be present in levels that are below detectable limits (<0.1 µg/L) at all sampled sites (Appendix 3). Similarly, from the same group as DDT, Aldrin was below detectable limits (<0.1 µg/L) from all sites. Dieldrin revealed to have slightly higher concentrations than DDT and Aldrin, and was measured to be <0.2 µg/L at all sites. For the dry season, DDT showed similar results as the wet season readings with values of <0.1µg/L from all the sites (Appendix 4). Aldrin was also <0.1 µg/L for all sites while Dieldrin was measured to be <0.2 µg/L for all the sampling sites.

Polychlorinated Biphenyls (PCBs) were measured in all their forms, and the wet season results showed only two different values: <0.1 µg/L and <1 µg/L, whereby all the measured PCBs at sites 3, 4, 5 measured concentrations of <0.1 µg/L while the values measured at sites 1, and 2 were <1 µg/L (Appendix 5). For the dry season results, all measured PCBs have recorded values of <0.01 µg/L for all the sampling sites (Appendix 6).

The Semi-Volatile Organic Compounds (SVOCs) wet season results for sites 1, 2, and 3 ranged between <0.1 µg/L and <10 µg/l and between <10 µg/L and <100 µg/L for sites 4 and 5 (Appendix 7). While for the dry season, all the measured SVOCs showed concentrations that ranged between <0.1 µg/L and <10 µg/L which were recorded from site 1 through to site 5 (Appendix 8).

Finally, wet season results for Phenolic compounds showed a range of between <1 µg/L and <160 µg/L (Appendix 9). Simple phenol and 3- and 4-Methylphenol (m+p-cresol) are the only two phenolic compounds that had varying amounts with phenol ranging from <20 µg/L to 50 µg/l while 3- and 4-Methylphenol (m+p-cresol) ranged between <1 µg/L and 160 µg/L. Phenol concentrations were the highest at sites 4 and 5 for both wet and dry seasons. The dry season results (Appendix 10) showed all members of the phenols family to have concentrations of <1 µg/L except for phenol with concentrations of 20 µg/L (sites 1–3) and <20 µg/L (sites 4–5).

4.3. SEDIMENT CHARACTERISTICS

Sediment samples were collected during the wet season (September 2018) and the dry season (June 2019) in order to determine physical and chemical sediment characteristics such as grain sizes, moisture content, and organic content. This section presents the results obtained from the analysis of collected sediment samples.

4.3.1. Moisture and Organic content

Percentage moisture content for the wet season ranged between 17.7% and 22% across the sampled sites (Table 4.8). The lowest percentage (17.7%) was recorded at site 4 while the highest percentage was recorded at site 5. The dry season moisture content results were notably lower than the wet season results, except for the value at site 1 which varied significantly from the other dry season values, and was also higher than the highest wet season value. The range of the dry season moisture content was 6% to 24.5% with the latter value being the one that greatly varied from the rest (Table 4.8). The lowest moisture content

(6%) was measured at site 5 and the highest moisture content (24.5%) was measured at site 1.

Table 4.8: Percentage moisture content for the Kaalspruit sediment during wet season sampling (September 2018) and dry season sampling (June 2019).

Wet season Dry season

Site Moisture content (%) Site Moisture content (%)

Site 1 19.5 Site 1 24.5

Site 2 19 Site 2 12

Site 3 21.6 Site 3 8.7

Site 4 17.7 Site 4 9.1

Site 5 22 Site 5 6

Moreover, organic content for the wet season fell within the medium range for the wet season; this is according to USEPA (1991) (Table 4.9). The lowest measured organic content was found at site 3 with 1% organic content, and the highest content was recorded at site 5 with 2% organic content (Table 4.10). Organic content values for the dry season ranged between moderately low to slightly high, with the range in values being 1% – 4.4% (Table 4.10). The content was recorded at sites 4 and 5 while the highest was recorded at site 1.

Table 4.9: Categories of sediment organic content (USEPA, 1991).

Category Percentage organic content

Very low <0.05%

Low 0.05% – 1%

Moderately low 1% - 2%

Medium 2% - 4%

High >4%

Table 4.10: Percentage organic content for the Kaalspruit during wet season sampling (September 2018) and dry season sampling (June 2019).

Wet season Dry season

Site Organic content (%) Site Organic content (%)

Site 1 1.5 Site 1 4.4

Site 2 1.5 Site 2 1.5

Site 3 1 Site 3 4

Site 4 2 Site 4 1

Site 5 1.5 Site 5 1

4.3.2. Grain sizes

Grain sizes for the collected wet season sediment and dry season sediment were determined by use of the Star screens test sieve. The grain sizes results are presented according to the categorization of Cyrus et al. (2000). The results are presented as percentages from each sampled site.

The wet season results revealed that coarse sand category (500 µm – 2000 µm) make up the largest portion, with the highest percentage of the sampled sediment from all sites (Figure 4.6). The lowest percentage was observed at the mud category (<53 µm). The second lowest percentage was very fine sand (53 µm – 212 µm), while the second highest percentage was medium sand (212 µm– 500 µm).

120

100

80 >4000 2000-4000 60 500-2000

Grain (%) size 212-500 40 53-212

20 0-53

0 Site 1 Site 2 Site 3 Site 4 Site 5 Sampling site

Figure 4.6: Grain size distribution of the Kaalspruit sediment during wet season sampling (September 2018).

Similar to the wet season results, the dry season results revealed the category with the highest percentage to be coarse sand (500 µm – 2000 µm), and the category with the lowest percentage to be mud (<53 µm) (Figure 4.7). The second lowest category was very fine sand (53 µm – 212 µm) and the second highest category was very coarse sand (2 000 µm – 4 000 µm).

120

100

80 >4000 2000-4000 60 500-2000

Grain (%) size 212-500 40 53-212

20 <53

0 Site 1 Site 2 Site 3 Site 4 Site 5 Sampling site

Figure 4.7: Grain size distribution of the Kaalspruit sediment during dry season sampling (June 2019).

4.3.3. Metals in sediment

Sediment samples were sent to the UIS Organic laboratory in order to determine the presence of chemical variables such as metals and chemical compounds. This section presents the chemical results for the samples sediments as tested in the laboratory.

Sediment chemical results for the wet season have shown the Aluminium (Al) values to range between 10 368 mg/kg and 26 747 mg/kg with the lowest observed at site 2 and the highest observed at site 4 (Table 4.11). Calcium (Ca) values appeared to range between 280 mg/kg and 5 252 mg/kg with the lowest observed at site 1 and the highest observed at site 2. Chromium (Cr) results showed that all sites had concentrations that fell above probable effect levels (PELs) according to the Canadian Sediment Quality Guidelines (CSQG) (2001). The lowest Cr concentration was observed at site 2 (276 mg/kg) and the highest value observed at site 4 (544 mg/kg). Values for Copper (Cu) ranged between 12 mg/kg and 24 mg/kg with the lowest values observed at site 1 and the highest value observed at site 5 and these concentrations were within Interim Sediment Quality Guidelines (ISQGs) as per CSQG Guidelines (2001). For Iron (Fe) the measured values ranged

68 between 7 226 mg/kg and 19 673 mg/kg with the lowest measure recorded at site 1 and the highest measured at site 5. Potassium (K) values appeared relatively high with the lowest value being 9 623 (site 5) and the highest value being 24 865 mg/kg (site 1). Values for Magnesium (Mg) ranged between 0 mg/kg (site 1) and 2 395 mg/kg which was recorded at site 4. Manganese (Mn) values were relatively low and showed a range of 123 mg/kg to 1 229 mg/kg, with the lowest recorded at site 1 and the highest at site 4. The lowest value recorded for Sodium (Na) was 3 178 mg/kg measured at site 5 and the highest recorded value was 5 123 mg/kg measured at site 1. Phosphorus (P) values were relatively low from all sites with the lowest value being 183 mg/kg measured at site 4 and the highest value being 471 mg/kg measured at site 2. Lead (Pb) values were also fairly low and fell within ISQGs with the lowest values recorded at site 5 (5.59 mg/kg) and the highest recorded at site 1 (19 mg/kg). Values for Silicon (Si) were significantly high with the lowest recorded value being 228 897 mg/kg which was measured at site 2 and the highest value being 285 200 mg/kg which was recorded at site 5.

For the dry season, values for Al ranged between 14 562 mg/kg measured at site 2 and 35 245 mg/kg measured at site 4 (Table 4.12). Ca values ranged between 2 506 mg/kg measured at site 4 and 5 146 mg/kg measured at site 3. Chromium concentrations for the dry season also fell above PELs with values that ranged between 110 mg/kg and 148 mg/kg measured at site 2 and site 4 respectively. Moreover, Cu still depicted concentrations that fell within ISQGs for the dry season with values that ranged between 0 mg/kg and 4.08 mg/kg measured at site 2 and site 1 respectively. Values for Fe ranged between 13 152 mg/kg and 44 577 mg/kg with the lowest value recorded at site 3 and the highest value recorded at site 5. Results for K are relatively higher with the lowest value being 9 222 mg/kg (site 5) and the highest being 18 024 mg/kg (site 3). For the Mg results, the lowest recorded value was 1 202 mg/kg recorded at site 4 and the highest value was 2 193 mg/kg recorded at site 3. Moreover, Mn values ranged between 275 mg/kg (site 2) and 2 821 mg/kg (site 1). Values for Na ranged between 2 743 mg/kg measured at site 1 and 5 738 mg/kg measured at site 3. Phosphorus values ranged between 685 mg/kg (site 4) and 1 156 mg/kg (site 1). For Pb, the lowest recorded value was 7.50 mg/kg measured at site 5 and the highest recorded value was 34 mg/kg which was measured at site 1, which all fell within ISQGs. Finally, Si values are also significantly higher than the rest of the variables and also higher than wet season Si values. The lowest recorded value for Si is 289 113 mg/kg recorded at site 1 and the highest value 376 494 mg/kg recorded at site 5.

Table 4.11: Chemical variables determined in sediment for the Kaalspruit during wet season sampling (September 2018). Values were compared with the Canadian Environmental Quality Guidelines for sediment (2001).

Detection Parameter limit Unit Site 1 Site 2 Site 3 Site 4 Site 5 Al <0.001 mg/kg 12 595 10 368 19 354 26 747 24 454 Ba <0.001 mg/kg 68 231 130 197 130 Be <0.001 mg/kg 0.961 1.53 1.01 1.09 0.497 Ca <1 mg/kg 280 5 252 2 161 4 790 1 876 Ce <0.001 mg/kg 0 6.71 0.624 4.59 2.16 Co <0.001 mg/kg 3.91 9.27 5.34 8.25 5.12 Cr <0.001 mg/kg 379 276 442 544 457 Cs <0.001 mg/kg 7.43 2.23 0.730 1.14 0.749 Cu <0.001 mg/kg 12 15 16 24 13 Fe <0.025 mg/kg 7 226 8 965 15 330 15 170 19 673 Ga <0.001 mg/kg 7.84 13 8.80 12 7.06 Ge <0.001 mg/kg 0.791 0.773 0.686 0.868 0.678 Hf <0.001 mg/kg 73 7.53 5.60 6.82 4.51 K <0.5 mg/kg 24 865 17 325 15 437 13 972 9 623 Li <0.001 mg/kg 6.39 13 7.13 13 4.17 Mg <1 mg/kg 0 784 770 2 395 958 Mn <0.025 mg/kg 123 285 160 1 229 537 Mo <0.001 mg/kg 27 29 19 14 24 Na <1 mg/kg 5 123 4 818 5 000 4 391 3 178 P <0.001 mg/kg 159 471 247 183 260 Pb <0.001 mg/kg 19 18 15 14 5.59 Rb <0.001 mg/kg 80 33 32 32 30 Sc <0.001 mg/kg 52 59 60 56 60 Si <0.2 mg/kg 251 418 228 897 277 148 255 090 285 200 Sr <0.001 mg/kg 4.60 63 17 30 24 Th <0.001 mg/kg 19 3.94 0.884 2.24 1.43 Ti <0.001 mg/kg 1 036 1 144 770 1 929 564 U <0.001 mg/kg 1.50 1.89 1.56 1.35 0.895 V <0.001 mg/kg 47 76 54 52 45 Zr <0.001 mg/kg 73 82 67 83 53 Within ISQGs Above PELs

Table 4.12: Chemical variables determined in sediment for the Kaalspruit during dry season sampling (June 2019). Values were compared with the Canadian Environmental Quality Guidelines for sediment (2001).

Detection Parameter limit Unit Site 1 Site 2 Site 3 Site 4 Site 5 Al <0.001 mg/kg 16 750 14 562 26 990 35 245 27 790 Ba <0.001 mg/kg 149 184 151 146 118 Be <0.001 mg/kg 2.42 0.962 0.378 0.406 0.570 Ca <1 mg/kg 5 204 5 082 5 146 2 506 3 734 Ce <0.001 mg/kg 1.89 5.77 12 4.03 5.50 Co <0.001 mg/kg 3.65 0.673 0.927 0.668 0.803 Cr <0.001 mg/kg 121 110 125 148 126 Cs <0.001 mg/kg 0.390 0.887 0.810 0.615 0.567 Cu <0.001 mg/kg 4.08 0 0.201 0.521 0.278 Fe <0.025 mg/kg 14 673 19 481 13 152 23 619 44 577 Ga <0.001 mg/kg 6.43 3.49 3.23 2.45 1.85 Hf <0.001 mg/kg 8.07 3.98 3.79 3.42 2.99 K <0.5 mg/kg 11 726 17 250 18 024 10 385 9 222 Li <0.001 mg/kg 20 9.48 7.93 5.15 5.12 Mg <1 mg/kg 1 281 2 044 2 193 1 202 1 804 Mn <0.025 mg/kg 2 821 275 319 789 957 Mo <0.001 mg/kg 1.23 2.77 3.17 5.12 4.52 Na <1 mg/kg 2 743 5 493 5 738 3 046 3 282 P <0.001 mg/kg 1 156 881 746 685 832 Pb <0.001 mg/kg 34 19 18 10 7.50 Rb <0.001 mg/kg 3.46 12 12 8.64 9.30 Sc <0.001 mg/kg 2.55 1.38 2.45 1.58 1.56 Si <0.2 mg/kg 289 113 346 917 354 688 366 349 376 494 Sr <0.001 mg/kg 7.80 15 13 11 11 Th <0.001 mg/kg 2.77 3.14 2.93 1.51 1.93 Ti <0.001 mg/kg 2 152 568 508 474 362 U <0.001 mg/kg 3.22 2.26 2.28 1.08 1.20 V <0.001 mg/kg 55 23 28 18 20 Zr <0.001 mg/kg 21 10 7.78 12 8.76 Within ISQGs Above PELs

4.3.4. Organic compounds in sediment

The chemical compounds results for sediment in the wet season has revealed the presence of Organochlorine Pesticides (OCPs) in fair amounts. Dichlorodiphenyl trichloroethane (DDT) and its metabolites (DDE and DDD) showed to be present in all sites. DDT depicted concentrations of <2 µg/kg at four sites (site 1, 2, 3, 4) and the highest value was recorded at site 5 with concentrations of 19 µg/kg (Table 4.13). The four sites showed to be above interim sediment quality guidelines (ISQGs) but below probable effect levels (PELs) while site 5 concentration was above (PELs). DDE showed concentrations above ISQGs but below PELs for all sites. While concentrations for DDD were above PELs for sites 4 and 5 and above ISQGs but below PELs for the remaining sites. Dieldrin and endrin both showed concentrations of above ISQGs and below PELs for all sites. Moreover, gamma-HCH showed concentrations above PELs with values of <20 µg/kg for all sites. Delta-HCH and beta-HCH have shown to have the highest values both scoring <40 µg/kg for all the sites.

Dry season results have shown a similar trend to wet season results with slight variations on DDT. For the dry season, DDT was the highest at site 4 with 16 µg/kg and the lowest at sites 1 and 3 with values of <2 µg/kg (Table 4.14). Sites 4 and 5 fell above PELs while the rest of the sites were above ISQG but below PELs. All DDE sites fell above ISQGs but below PELs while DDD concentrations fell above PELs at sites 4 and 5 with the rest of the sites falling above ISQG but below PELs. Diedrin and Endrin still fell above ISQGs but below PELs for all sites. While gamma-HCH still showed concentrations of <20 µg/kg and fell above PELs. Finally, beta-HCH and delta-HCH have also scored high values for the dry season with recorded values of <40 µg/kg for all sites as similar to the wet season.

Table 4.13: Organochlorine pesticides determined in sediment for the Kaalspruit during wet season sampling (September 2018). Values were compared with the Canadian Environmental Quality Guidelines for sediment (2001).

Site unit Alpha- Beta- Gamma Delta- Alpha- Gamma- Aldrin Dieldrin Endrin Heptachlor Heptachlor Methoxy- 4-4'- 4-4'- 4-4'- number HCH HCH -HCH HCH Chlordane Chlordane Epoxide chlor DDD DDE DDT Isomer B Site 1 µg/kg <2 <40 <20 <40 <2 <2 <2 <4 <20 <2 <2 <2 <2 2 <2 Site 2 µg/kg <2 <40 <20 <40 <2 <2 <2 <4 <20 <2 <2 <2 <2 2.8 <2 Site 3 µg/kg <2 <40 <20 <40 <2 <2 <2 <4 <20 <2 <2 <2 <2 <2 <2 Site 4 µg/kg <2 <40 <20 <40 <2 <2 <2 <4 <20 <2 <2 <2 37 <2 <2 Site 5 µg/kg <2 <40 <20 <40 <2 <2 <2 <4 <20 <2 <2 <2 60 <2 19 above ISQGs and below PELs Above PELs

Table 4.14: Organochlorine pesticides determined in sediment for the Kaalspruit during dry season sampling (June 2019).

Site Heptachlor Alpha- Beta- Gamma Delta- Alpha- Gamma- Methoxy- 4-4'- 4-4'- 4-4'- number Unit Aldrin Dieldrin Endrin Heptachlor Epoxide HCH HCH -HCH HCH Chlordane Chlordane chlor DDD DDE DDT Isomer B Site 1 µg/kg <2 <40 <20 <40 <2 <2 <2 <4 <20 <2 <2 <2 2.5 5.6 <2 Site 2 µg/kg <2 <40 <20 <40 <2 <2 <2 <4 <20 <2 <2 <2 <2 2.3 2.2 Site 3 µg/kg <2 <40 <20 <40 <2 <2 <2 <4 <20 <2 <2 <2 7.6 <2 <2 Site 4 µg/kg <2 <40 <20 <40 <2 <2 <2 <4 <20 <2 <2 <2 33 <2 16 Site 5 µg/kg <2 <40 <20 <40 <2 <2 <2 <4 <20 <2 <2 <2 24 <2 5

Polychlorinated Biphenyls (PCBs) in all its tested forms was present in sediment and all the PCBs recorded concentrations of <11.7 µg/kg for both wet and dry seasons. These sediment concentrations for PCBs are notably higher than the PCBs concentrations in the water quality results. Furthermore, wet season results for the Semi-Volatile Organic Compounds (SVOCs) showed their range to be between <2 µg/kg and <200 µg/kg for all sampling sites (Table 4.15). Similarly, in the dry season, SVOCs showed the same range as the wet season of between <2 µg/kg and <200 µg/kg (Table 4.16).

Table 4.15: Semi-volatile organic compounds determined in sediment for the Kaalspruit during wet season sampling (September 2018).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Naphthalene µg/kg 3.9 7.4 3 <2 2 Acenaphthene µg/kg <2 <2 <2 <2 <2 Fluorene µg/kg 2.7 <2 <2 <2 <2 Phenanthrene µg/kg 24 30 8.2 6.6 13 Anthracene µg/kg 5.4 6.9 <2 <2 <2 Fluoranthene µg/kg 38 23 6.5 4.3 6.8 Pyrene µg/kg 29 18 4.7 3.2 5.6 Polycyclic Aromatic Benzo(a)anthracene µg/kg 15 7.8 2.1 <2 3.7 Hydrocarbons Chrysene µg/kg 15 9.4 2.6 <2 4.2 Benzo(b+k)fluoranthene µg/kg 37 20 5.8 2.5 7.3 Benzo(a)pyrene µg/kg 18 7.7 2.2 <2 3.1

Benzo(g,h,i)perylene µg/kg <20 <20 <20 <20 <20

Dibenz(a,h)anthracene µg/kg <100 <100 <100 <100 <100 Indeno(123-cd)pyrene µg/kg <20 <20 <20 <20 <20 1,2-Dichlorobenzene µg/kg <20 <20 <20 <20 <20 1,4-Dichlorobenzene µg/kg <20 <20 <20 <20 <20 2-Chloronaphthalene µg/kg <20 <20 <20 <20 <20 Hexachlorobenzene µg/kg <20 <20 <20 <20 <20 Hexachloroethane µg/kg <20 <20 <20 <20 <20 Chlorinated 4-Chlorophenylphenyl µg/kg <20 <20 <20 <20 <20 Compounds ether* 4-Bromophenylphenyl µg/kg <20 <20 <20 <20 <20 ether Di-n-butyl phthalate µg/kg <200 <200 <200 <200 <200 Phthalates Butyl benzyl phthalate µg/kg <200 <200 <200 <200 <200 Bis(2-ethylhexyl) µg/kg <200 <200 <200 <200 <200 phthalate

Table 4.16: Semi-volatile organic compounds determined in sediment for the Kaalspruit during dry season sampling (June 2019).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Naphthalene µg/kg 3 7 2.5 <2 2 Acenaphthene µg/kg <2 <2 <2 <2 <2 Fluorene µg/kg 2 <2 <2 <2 <2 Phenanthrene µg/kg 20 25 7.2 5.5 10 Anthracene µg/kg 5.4 6.9 <2 <2 <2 Fluoranthene µg/kg 30 20 5.5 4 5.8 Pyrene µg/kg 20 15 4 3 5 Polycyclic Aromatic Benzo(a)anthracene µg/kg 12 7.1 2.1 <2 3.1 Hydrocarbons Chrysene µg/kg 11 9 1.6 <2 4.2 Benzo(b+k)fluoranthene µg/kg 31 18 5.1 2.1 6.3 Benzo(a)pyrene µg/kg 14 7 1.2 <2 2.1

Benzo(g,h,i)perylene µg/kg <20 <20 <20 <20 <20

Wet season results for the phenolic compounds showed phenol in its simplest form to have the highest concentrations with measured values of <400 µg/kg for all sites, while 3- and 4- Methylphenol (m+p-cresol) was second highest with varying values that ranged between <20 µg/kg and 190 µg/kg (Table 4.17). The rest of the phenols showed concentrations of <20 µg/kg from all the sampled sites. Dry season results showed phenol to still have the highest concentrations with values for all the sites being <400 µg/kg and the rest of the phenols for all the sites having had concentrations of <20 µg/kg.

Table 4.17: Phenolic determined in sediment for the Kaalspruit during wet season sampling (September 2018).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Phenol µg/kg <400 <400 <400 <400 <400 2-Chlorophenol µg/kg <20 <20 <20 <20 <20 2,4-Dichlorophenol µg/kg <20 <20 <20 <20 <20 2,6-Dichlorophenol µg/kg <20 <20 <20 <0 <20 2-Methylphenol (o-cresol) µg/kg <20 <20 <20 <20 <20 3- and 4-Methylphenol µg/kg <20 190 46 <100 <20 (m+p-cresol) 2,4-Dimethylphenol µg/kg <20 <20 <20 <20 <20 2,4,5-Trichlorophenol µg/kg <20 <20 <20 <20 <20 2,4,6-Trichlorophenol µg/kg <20 <20 <20 <20 <20 4-Chloro-3-methylphenol µg/kg <20 <20 <20 <20 <20 2,3,4,6-Tetrachlorophenol µg/kg <20 <20 <20 <20 <20 Pentachlorophenol µg/kg <20 <20 <20 <20 <20

4.4. AQUATIC MACROINVERTEBRATE ASSESSMENT

South African Scoring System-Version 5 (SASS5) biomonitoring technique was applied to determine the presence and abundance of macroinvertebrate taxa at family level. This technique was undetaken in conjunction with the water and sediment collection during the two sampling periods (September 2018 and June 2019). It is important to note that SASS5 was only undertaken at three sites (sites 3, 4, and 5) due to the stagnant nature of the water at the other two sites (sites 1 and 2) which disqualifies them from the undertaking of SASS5, as SASS5 is only applicable to flowing waters (Dickens & Graham, 2002).

SASS5 results for the wet season revealed poor presence of macroinvertebrate taxa from the sampled sites with fairly low scores and abundance. Results showed that one family was discovered at site 3; three families at site 4; and five families at site 5 (Table 4.18). In total, seven families were discovered during the wet season sampling with one family appearing at more than one site. The identified families have relatively low quality values which indicate tolerance to pollution. The lowest SASS score observed was 2 identified at site 3 and highest score was 12 which was identified at site 5. Sites 3 and 4 shared the lowest observed average score per taxa (ASPT) at the value of 2, while the highest ASPT was 2.4 observed at site 5 (Table 4.18). In general, most of the identified species were sampled from the vegetation biotope, with few coming from the gravel, sand and mud biotope and none came from the stones biotope.

The obtained SASS5 results for the wet season have indicated poor ecological state of the sampled sites when compared to the Highveld ecological bands as well as ecological categories (Figure 4.8). The SASS scores and ASPT for the sites place all the sites at category E/F which indicates that the system is in a seriously/critically modified state.

Table 4.18: SASS5 results for the Kaalspruit during wet season sampling (September 2018).

Sensitivity score (Dickens and Taxon Site 3 Site 4 Site 5 Graham, 2002) Chironomidae (Midges) 2 ✓ ✓ ✓ Culicidae (Mosquitoes) 1 ✓ Ephydridae (Shore flies) 3 ✓ Oligochaeta (Earthworms) 1 ✓ Physidae (Pouch snails) 3 ✓ Simuliidae (Black flies) 5 ✓ Syrphidae (Rat tailed maggots) 1 ✓ SASS score 2 6 12 Number of taxa 1 3 5 ASPT 2 2 2.4 Class E/F E/F E/F

Kaalspruit Biomonitoring: Upper Highveld Ecological Zone 8,0

7,0

6,0

A 5,0 S 4,0 P T 3,0 S5 2,0 S3 S4 E/F D C B A 1,0

0,0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 SASS Score

Figure 4.8: ASPT as a function of SASS score plotted within biological bands for Kaalspruit (which falls within the Upper Highveld ecological zone) during wet season sampling (September 2018).

The dry season SASS5 results have indicated a decline in identified families compared to the wet season, coupled with poor abundance. The results showed that two families were identified at site 3, three families at site 4, and one family at site 5 (Table 4.19). A total of four families were identified from the three sampled sites with two families discovered at more than one site. The lowest SASS score was 2 measured at sites 3 and 5, while the highest score was 8 measured at site 4. The lowest ASPT was 1, obtained at site 3, while the highest ASPT was 2.7 obtained at site 4 (Table 4.19). The vegetation biotope is the one where most of the species were identified with few coming from the stones biotope and the gravel, sand and mud biotope.

These results indicate that all the sampled sites for the dry season fell within ecological class E/F (Figure 4.9) which indicates that there is low species diversity as the system is seriously/critically modified.

Table 4.19: SASS5 results for the Kaalspruit during dry season sampling (June 2019).

Sensitivity score (Dickens and Taxon Site 3 Site 4 Site 5 Graham, 2002) Chironomidae (Midges) 2 ✓ ✓ Hydrophilidae (Water scavenger beetles) 5 ✓ Oligochaeta (Earthworms) 1 ✓ Syrphidae (Rat tailed maggots) 1 ✓ ✓ SASS Score 2 8 2 Number of taxa 1 3 2 ASPT 2 2.7 1 Class E/F E/F E/F

Kaalspruit Biomonitoring: Upper Highveld Ecological Zone 8,0

7,0

6,0

A 5,0 S 4,0 P T 3,0 S4

2,0 S3 E/F D C B A 1,0 S5

0,0 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 SASS Score

Figure 4.9: ASPT as a function of SASS score plotted within biological bands for Kaalspruit (which falls within the Upper Highveld ecological zone) during dry season sampling (June 2019).

4.5. HABITAT ASSESSMENT

Integrated Habitat Assessment System (IHAS) technique was undertaken in order to determine and understand the quality and diversity of macroinvertebrate habitats available. IHAS method was conducted on all sampling sites in order to determine possible habitat quality even for sites where SASS 5 was not conducted.

IHAS results showed a similar trend such that all IHAS values for the wet season are higher than IHAS values for the dry season. Three of the sampled sites (site 1, 2 and 5) fell under IHAS class D indicating that they are in a poor state. While sample sites 3 and 4 fell under IHAS class C indicating that they are in fair/adequate states with some modification. The lowest IHAS scores were observed at site 1 for both wet and dry season, with values of 34 for the wet season and 31 for the dry season, which places the site under class D (Tables 4.20 and 4.21). Site 1 appeared to have poor habitat diversity with close to absent stones-in- current. Vegetation was mostly grass which also sparsely distributed and some areas having no bank cover. Moreover, stream conditions showed pool and still waters. On the contrary, the highest IHAS scores were recorded at site 4 for both wet and dry season with scores of 59 for wet season and 56 for dry season, which places the site under category C as previously mentioned (Tables 4.20 and 4.21). This site showed better habitat conditions than all sites with better habitat diversity. Stones in current were fairly present for sampling where a total length of 5-10 m2 was sampled. Marginal vegetation was also present for sampling which were mostly grass/reeds. With stream conditions, the flow of water showed medium flow with fair bank cover.

Table 4.20: Integrated Habitat Assessment System (IHAS) results for the Kaalspruit during wet season sampling (September 2018).

IHAS biotopes Site 1 Site 2 Site 3 Site 4 Site 5 Sampling habitat Stones 2 7 16 15 7 Vegetation 10 9 8 9 10 Gravel, sand and mud 12 12 9 13 10 Habitat score 24 28 33 37 27 Stream conditions 10 13 24 22 27 Total IHAS score 34 41 57 59 54 IHAS class D D C C D

Table 4.21: Integrated Habitat Assessment System (IHAS) results for the Kaalspruit during dry season sampling (June 2019).

IHAS biotopes Site 1 Site 2 Site 3 Site 4 Site 5 Sampling habitat Stones 2 7 16 15 7 Vegetation 8 9 7 8 9 Gravel, sand and mud 11 9 9 13 11 Habitat score 21 25 32 36 27 Stream conditions 10 13 23 20 26 Total IHAS score 31 38 55 56 53 IHAS class D D C C D

CHAPTER 5

DISCUSSION OF RESULTS

This chapter provides interpretation of the results presented in chapter 4, as well as supporting literature to compare the results and substantiate some of the findings. The first section of the chapter discusses water quality results which include in-situ physico-chemical parameters, nutrients, metals and chemical compounds and a discussion of the concentrations in relation to water quality guidelines. The second section discusses sediment results, including metals and chemical compounds observed in sediment which are related to sediment quality guidelines. Finally, macroinvertebrate and habitat assessment results are discussed in the last section including the identified taxa and related habitat diversity.

5.1. WATER QUALITY

5.1.1. In-situ physico-chemical water parameters pH results for both wet and dry seasons of sampling for the study indicated slight acidity and slight alkalinity with some sites showing values closer to neutrality. Levels found have shown to be between ideal and tolerable limits for pH values according to the benchmark criteria compiled by Kotze (2002) from Target Water Quality Ranges (TWQRs) by DWAF (1996b), and water quality guidelines by Rand Water (1998). These findings were found to be similar to the pH values found by Walsh and Grobler (2016), who conducted a study on the upstream and midstream sites of the current study along the Kaalspruit. Their study revealed that pH values for the said sites were within ideal limits according to DWAF (1996b) Guidelines. Similar results were also observed from a study conducted by Nawn (2004), who focused on the two downstream sites of the current study area (one in Kaalspruit and one in Olifantspruit). The study found pH values to be within tolerable limits and favourable for aquatic ecosystems. It is important, however, to note that pH alone does not provide a concrete representation of suitability for aquatic ecosystems, its interaction with other water constituents and their levels can alter the favourability of aquatic ecosystems (DWAF, 1996b).

Electrical Conductivity (EC) is a measure of the capability of water to conduct electric current due to the presence of ions such as chloride, sulphate, nitrate, sodium, calcium that carry electrical charge (DWAF, 1996b). Therefore, EC is directly proportional to Total Dissolved Solids (TDS) because as the size of solids/salts dissolved in water increases, so does the ability for the particular water to conduct electricity (DWAF, 1996b). The values for electrical 84 conductivity ranged between 662.2 µS/cm and 912.9 µS/cm for the wet season and between 627 µS/cm and 734 µS/cm for the dry season. These values fell under the tolerable category according to the benchmark criteria compiled by Kotze (2002). The TDS results indeed showed direct proportionality to the EC results, also with minimal variations between the wet and dry seasons. It was noted that EC and TDS results for the wet season generally showed higher concentrations than dry season results, and this can be ascribed to wet season rains that overflow to the river during rainy seasons (FAO, 2019). Although site 2 (Ivory Park- Freedom Drive) and site 5 (Olifantsfontein) generally attained higher EC and TDS values, overall, there were minor variations in EC and TDS concentrations across the sites except at Site 4 (Clayville) which showed relatively lower concentrations for both seasons. The relatively high concentrations at sites 1, 2, and 3 which are located in the townships of Tembisa and Ivory Park could be ascribed to run-off from the townships, where open spaces, informal settlements and some roads which are not tarred are present. The also generally high values of EC and TDS from site 5 (Olifantsfontein) can possibly be a result of run-off passing through agriculture fields surrounding the area, transporting dissolved substances into the river.

These findings are supported by Nawn (2004) who conducted a study on the Kaalspruit and Olifantspruit and their impacts on the Hennops River. Nawn (2004) similarly found that the Kaalspruit and Olifantspruit sites showed EC and TDS levels to be higher than other sampling sites. According to Nawn (2004), these results were attributed to run-off from the townships and loss of vegetation which causes erosional activity. While the Olifantspruit results were ascribed to run-off emanating from agricultural holdings in the area (Nawn, 2004). In a broad sense, high EC and TDS reflect the pollution burden of aquatic systems (Mero, 2011). However, all EC values for the current study were within TWQRs.

Temperature is one of the most important water parameters as it is one of the factors that contribute to the distribution of aquatic organisms (DWAF, 1996b). Temperature results for the current study revealed that wet season results were generally higher than the dry season results with the exception of site 4 that recorded a notably lower value, a value even lower than all dry season values. Higher values for the wet season (warm season) over the dry season can be attributed to the generally warmer weather conditions as opposed to the dry season (cold season). This phenomenon was also observed from a study by Roos and Pieterse (1994) who reported on the seasonal variations of temperature in the Vaal River marked by warm water during warm season (September, October and November) and rapid cooling during colder seasons (April, May, June). Moreover, a study conducted by Walsh and Grobler (2016) on the Kaalspruit was undertaken during the warm season (December 2016) and the study shows similar values to the warm season results for the current study 85 with temperature values ranging between 25°C and 29.4°C. Additionally, a study conducted by Barakat et al. (2016) on the Oum Er Rbia River in Morocco revealed that the temperature results for the sampling sites were higher during warm weather season with the highest value being 39°C. Temperature values recorded for the Kaalspruit are within the range stipulated by DWAF (1996b) for inland waters, which is 5°C – 30°C. The Department of Water Affairs and Forestry DWAF (1996b) indicated that thermal characteristics of waters depend on geographical features including:

• Altitude and latitude of the river, • Factors relating to the hydrology of the river such as groundwater contribution and flow rate, • Climatic factors like wind speed, cloud cover, air temperature and rain, • Structural characteristics of the river such as vegetation cover, water depth and turbidity, water volume and channel form. The significant variation in the temperature readings between site 4 and the other sites during the warm season could be ascribed to structural characteristics of the site. This site is also among the bottom two lowest values for the cold season. Temperature effects on aquatic organisms may be observed at an individual level or community level by favouring organisms that are temperature tolerant than ones which are temperature intolerant (Dallas, 2009). In South Africa, freshwater fish are classed into temperate and tropical fauna; with the former surviving in maximum water temperatures of generally below 25°C to 28°C, and the latter surviving in water temperatures of 15°C to 18°C (Skelton, 1993). Although most of the sites showed temperature values favourable to both tropical and temperate fauna, no fish species were observed in any of the sites. The absence of fish species may be ascribed to the presence of other pollutants and low dissolved oxygen in the water.

Dissolved oxygen (DO) is the amount of oxygen available for the support of aquatic life and is measured as concentration or percentage saturation of the concentration (DWAF, 1996b). The Department of Environmental Affairs and Forestry (DWAF, 1996b) does not prescribe TWQRs for DO as concentrations but present them as percentage saturation. Therefore, only the percentage saturation results will be discussed so they can be compared to the TWQRs by DWAF (1996b). Percentage saturation for all sites during the wet season ranged between 8% - 59% with the lowest percentage at site 1 (Tembisa) and the highest at site 3 (Ivory Park-Freedom Drive). These values fall within intolerable limits and indicate poor oxygen concentration. However, site 3 (Ivory Park-Freedom Drive) and site 5 (Olifantsfontein) are at the borderline of intolerable category and close to tolerable category. These results imply lethal conditions which cannot support aquatic biota as they cause acute

86 effects on aquatic biota (DWAF, 1996b). Moreover, the sensitivity of invertebrates and fish to DO concentrations variations is dependent on species and life stages and any organisms in their early life stages depict more sensitivity to physiological stress stemming from the depletion of oxygen (Walsh and Grobler, 2016).

The dry season results generally show higher values than the wet season results, however, three sites (site 1, 2, and 4) still show intolerable limits but sites 3 and 5 fall within the tolerable limit category. The percentage saturation ranges between 12.3% and 67.5%. Site 3 (67.5%) and site 5 (65.1%) are the top two highest percentages and indicate tolerable conditions to aquatic biota. These seasonal variations in DO percentage saturation can be ascribed to the variations in temperature between wet season (warm season) and the dry season (cold season), as temperature has an influence on DO concentrations. Elevated temperatures reduce the solubility of DO and therefore decrease its concentration. Higher water temperatures increase the rates of organisms’ respiration, thereby increasing oxygen demand of aquatic organisms, whereby the further increase of oxygen demand leads to a decrease in dissolved oxygen (DWAF, 1996b). Therefore, changes in water temperature can be considered to be the cause of seasonal variations in DO for the current study. When comparing the DO percentage saturation results between the current study and the study conducted by Walsh and Grobler (2016), slight variations exist in the results. Walsh and Grobler (2016) reported percentages of 32% and 39% for sites 2 and 3 respectively while the current study recorded 22% and 59% for the respective sites. While both their percentage concentration has shown intolerable limits for both sites, the current study has found site 3 to be within tolerable limits. This could imply an improvement in DO concentrations from their 2016 study. These variations may be a result of temperature changes between the two studies, where temperatures attained by Walsh and Grobler (2016) were generally higher than observed ones for the current study. However, it is worth noting that from observations made during water sample collection and in-stream macroinvertebrate collection, there was no identification of aquatic biota such as fish or frogs from all the sampled sites, including the sites that fell within tolerable limits which may be a consequence of the low dissolved oxygen levels.

5.1.2. Nutrients and biological aspects

DWAF (1996b) does not indicate the TWQRs for nitrate and nitrite; however, it does state that inorganic nitrogen must not be changed by more than 15% of a water body. The nitrate and nitrite concentrations for the current study showed slight variations with most sites recording the same values. These nutrients showed the highest concentrations at site 5 for both wet and dry seasons. The high nutrient concentrations for Site 5 (Olifantsfontein) can

87 be ascribed to the run-off from the surrounding agricultural fields. These conclusions were also drawn by Nawn (2004) whose study also revealed nitrate and nitrite levels to be the highest at the Olifantsfontein site. In fact, the nutrient concentrations attained by Nawn (2004) were observed to be higher than concentrations observed in the current study as they ranged between 3.8 mg/L and 4.5 mg/L, and the author attributed the high concentrations to agriculture fields surrounding the site. Another study that found elevated nutrient levels at sites situated next to agricultural fields include a study by Barakat et al. (2016) conducted to assess the water quality variations of Oum Er Rbia River (Morocco). Leaching of agriculture land was concluded to be the cause of higher nitrate concentrations than in other sites (Barakat et al., 2016). Moreover, site 5 is located after the discharge point of a waste water treatment plant (WWTP) in Olifantsfontein; therefore, these high concentrations may be due to that inflow of wastewater (Nawn, 2004). The contribution of a WWTP to nutrient concentrations in water was also reported by Dunca (2018) when assessing water pollution of major transboundary rivers from Banat (Romania). High values of nitrogen compounds were identified at a site situated downstream of the wastewater discharge (Dunca, 2018). Riskin et al. (2003) also attributed the higher levels of nutrient loading in the Matfield River to the WWTP located upstream of the river site.

Total phosphates showed less variation for each season with the wet season values being the highest at site 2 (Ivory Park-Freedom Drive) and the dry season concentrations being the highest at site 3 (Ivory Park-Riverside Street). There are no specific TWQRs for phosphates but DWAF (1996b) states that they should not be changed by more than 15% from the condition of the water under non-impacted conditions. However, DWAF (1996b) indicates that the concentration of phosphorus for a certain system should be based on the known trophic status of that system. Therefore, any assessment to determine the concentrations of phosphorus should be complemented by determination of inorganic nitrogen to inorganic phosphorus ratio (N:P ratio), and any assessment to determine nitrogen concentrations should be complemented by the N:P ratio calculation. Although nitrogen (nitrate and nitrite) concentrations were fairly low and not cause for concern in the current study, the presence and concentration of phosphorus has affected the trophic status of the sampled sites. As stated by DWAF (1996b), the presence of phosphorus is an important factor in changing the influence of nitrogen on eutrophication. In the presence of adequate phosphorus, nitrogen- fixing organisms will make up for any shortages caused by low nitrogen concentrations by fixing atmospheric nitrogen (USGS, 2019). As such, N:P ratio for all the sites was calculated and all of them indicated hypertrophic conditions. These water conditions may be as a result of the sewage inputs and the surrounding agriculture fields to the sampling sites. Nawn (2004) reported on the high nutrient accumulation in the area and indicated the source of the

88 problem to be the surrounding agriculture fields. The land use map generated for the current study (Figure 3.2) has revealed that agriculture fields are still present close to the site, and therefore most likely to still be contributing to high loads of nutrients in the area as concluded by Nawn (2004). Furthermore, these conditions could also relate to the intolerable levels of DO from the sampled sites as all sites except two of them (sites 3 and 5) recorded intolerable levels of DO. This relation is made because systems struck by eutrophication generally have lower levels of DO (USGS, 2019). High organic loading accelerates oxygen depletion due to higher microbial activity (Dallas, 2009). Dallas (2009) investigated the cause of fish kills in Rietvlei, Western Cape, and concluded that the combination of high temperatures (>27°C) and organic loads, and therefore low concentrations of dissolved oxygen are responsible for the deaths of fish in the Rietvlei.

Chlorophyll results have shown great variations between wet season sampling and dry season sampling. Site 3 showed the highest concentrations for the wet season while site 5 showed the highest concentrations for the dry season. The TWQRs are not stipulated for chlorophyll. However, it is known that chlorophyll is a measure of the amount of algae found in water, and thus higher amounts of chlorophyll indicate higher amounts of algae in the water (DWAF, 1996b). Nitrogen results for the current study were higher during the wet season than during the dry season and this is seen to correspond with the chlorophyll results which were also higher during the wet season than the dry season. According to USGS (2019) excess nitrogen can cause overstimulation of growth of algae which further leads to decreased DO upon decomposition. Therefore, there exists a positive relationship between the presence of nitrogen and chlorophyll. Riskin et al. (2003) investigated nutrient and chlorophyll relations in selected streams in Massachusetts and New Hampshire and similar trends to the current study were observed. Their study revealed a positive correlation between chlorophyll-a and total nitrogen and phosphorus at open and closed canopy sites (Riskin et al., 2003).

Faecal coliform bacteria and E. coli are bacteria found in intestines of humans and organisms and are therefore indicators of faecal contamination (WHO, 1996). Therefore, the presence and levels of these bacteria in the river can be an indication of sewage discharges into the river (Chikodzi et al., 2017). Other sources of faecal coliforms can be animal waste, agriculture activities, and wastewater treatment plants (City of Boulders, 2007). Faecal coliforms alone are not normally pathogenic; however, they are considered as indicator organisms and therefore may indicate the presence of other pathogenic bacteria (Chikodzi et al., 2017). Moreover, coliform bacteria form colonies as they multiply and therefore their presence can be determined by counting colonies present in water (Murphy, 2007). According to Murphy (2007) over 200 colonies per 100 mL of coliform bacteria are an 89 indicator of pathogenic organisms in the water. For the current study, coliform bacteria results for all sites showed high concentrations which indicate faecal contamination. What can be depicted from the results is that sites 2, 3 and 4 appeared to generally have high concentrations of faecal coliforms. Two of the sites are located in Tembisa and Ivory Park townships (sites 2 and 3) and the high levels of faecal contamination could be ascribed to poor or lack of sanitation services in the surrounding informal settlements. In chapter 4 it was discussed about the sewage pipe discharging human waste from the pit toilets built in the informal settlements situated next to the river as site 3. The elevated concentrations of faecal coliforms in areas with poor sanitation were also observed by Chikodzi et al. (2017) in Mucheke and Shangase Rivers. The study established that the sites that showed high pollution levels and faecal coliform concentrations were surrounded by areas with rapid increases of unplanned settlements with no proper sanitation facilities (Chikodzi et al., 2017). Moreover, site 4 (located in Clayville where there are sanitation services) have indicated high levels of faecal coliform, this is most likely due to the fact that it is situated closely downstream of sites 2 and 3, which could imply the transportation of the coliforms from the upstream sites to downstream sites. The negative impacts of upstream sites to downstream sites, particularly nearby sites have been widely reported (Riskin et al., 2003; Barakat et al., 2016; Mbaruku, 2016; Chikodzi et al., 2017).

5.1.3. Metals in water

Metals that fell within the TWQRs for both wet and dry seasons and are considered to have ideal concentrations include calcium, potassium, and magnesium. Seasonal variations were noted for the mentioned ions; however, they were minimal. Sodium was considered to fall within tolerable limits of TQWR for the wet and dry seasons and also showed seasonal variations with wet season concentrations depicting to be generally higher than dry season concentrations. Calcium, potassium and magnesium are natural components of surface water and can be found in water through the dissolution of rocks as a result of weathering processes (Potasznik and Szymczyk, 2015). The presence of these metals is essential in water in concentrations that are tolerable. For example, calcium and magnesium are responsible for water hardness and may negatively influence toxicity of other metals (Lenntech, 2019). Therefore, the levels of these metals in the study area are not cause for concern.

Manganese revealed to be in the intolerable limit category with concentrations above the Chronic Effect Value. Chronic Effect Value (CEV) according to DWAF (1996b) is a concentration at which significant chronic effects are expected on up to 5% of aquatic biota. Manganese naturally occurs in rocks and soil and may sometimes be present due to

90 underground pollution sources (Lenntech, 2019). Manganese is one of the essential elements found in living organisms, which means it is essential for other organisms, including humans, to survive, but can be toxic upon exposure to high concentrations (Hermes et al., 2013). A study was conducted by Hermes et al. (2013) to investigate manganese concentrations in the Pardinho River (Southern Brazil) and further determine the pathways and human exposure to manganese. The study showed no direct relationship between high concentrations of manganese to anthropogenic activities/land uses, whereby manganese values indicated very minimal differences across different anthropogenic activities. It was concluded that the observed manganese concentrations might be of natural origin (Hermes et al., 2013). The same trend was observed in the current study area whereby manganese concentrations are similar through different land uses, settlement types and anthropogenic activities. It is therefore concluded that these concentrations could be of natural origin, possibly from the surrounding soils or rocks.

Aluminium concentrations for all sites and for both seasons fell within the intolerable category with concentrations exceeding Acute Effect Value (AEV) according to DWAF (1996b). Acute Effect Value (AEV) is considered as a concentration at which significant toxic effects are endured by up to 5% of aquatic biota (DWAF, 1996b). Aluminium results showed slight variations in concentrations across all sites, and generally showing higher concentrations at sites 4 (Clayville) and 5 (Olifantsfontein). Aluminium is the most abundant metal and the third most abundant element on the earth’s crust and can be introduced into the water through the weathering of rocks and minerals (DWAF, 1996b). Industries associated with aluminium include the paper industry, metal manufacturing industry, and the textile industry (DWAF, 1996b). There is an aluminium extrusion plant which deals with the transformation of aluminium into items with a specific cross-sectional outline; this plant is located approximately 3.5 km from site 4. There is also a steel manufacturing and distribution company about 3 km from site 4. The presence of these industries may explain concentrations of aluminium at sites 4 and 5 which are in close proximity to each other. However, according to DWAF (1996b), the toxicity of aluminium is dependent on pH levels as pH affects the chemistry of aluminium and also determines the response of organisms to dissolved aluminium. In acidic waters with pH ranges of 4.4 – 5.4 aluminium is toxic, with maximum toxicity occurring at pH levels of 5.0 – 5.2. For the current study, pH values were higher than these ranges indicating low toxicity.

Zinc (Zn) concentrations have also showed to be within intolerable limits showing concentrations that are above Chronic Effect Values (CEV) and Acute Effect Values (AEV). Zinc concentrations showed to be generally high at sites 4 and 5 (Clayville and Olifantsfontein). Zinc is an essential micronutrient for all organisms and can be introduced to 91 aquatic ecosystems through weathering and erosion and through industrial activity (DWAF, 1996b). Industrial activities normally associated with zinc and its compounds include metal galvanising, dye manufacture and processing, paints, pharmaceuticals and fertilisers (DWAF, 1996b). Several industries of this nature are present around sites 4 and 5. There are two well-known pharmaceutical companies located approximately 2 km away from site 4 (Clayville). There is also a hardware warehouse situated about 2.5 km from site 4 and a steel and galvanised roofing manufacturer located 2.5 km from site 5. These industries could most likely be responsible for high concentrations of this metal at the two sites.

5.1.4. Organic compounds in water

Persistent Organic Pollutants (POPs) are chemical compounds considered to be persistent in the environment as they are resistant to degradation either by physical, chemical or biological processes (Naidoo and Buckley, 2003). Worldwide, there is a list of 12 POPs which are considered as the ‘dirty dozen’ and they include furans; dioxins; Polychlorinated Biphenyls (PCBs), Organochlorine Pesticides (OCPs) such as DDT, chlordane, heptachlor, aldrin, dieldrin, and dendrin; SVOCs such as Hexachlorobenzene (HCB); as well as toxaphene and mirex (Naidoo and Buckley, 2003). Results for the current study show the presence of OCPs in minimal amounts. Organochlorine Pesticides like DDT and its metabolites (DDD and DDE), aldrin, dieldrin, and chlordane, all depicted concentrations <0.1 µg/L for both seasons, and with Heptachlor depicting concentrations <0.2 µg/L for both seasons. The focus was placed on these specific pesticides as they are currently banned in South Africa (Naidoo and Buckley, 2003), therefore their presence and abundance on the environment is important and worth noting. Pesticides are used in agriculture by large-scale or small-scale framers, and the sector is considered the major user of pesticides (Naidoo and Buckley, 2003). Pesticides are also used by government for the control of pests at public amenities; by industries for sterilization and pest control; and by the public for use in their homes and gardens (Quinn et al., 2011). The study area is situated around residential areas of different settlement types, therefore pesticides concentrations, although at very low and non-detectable concentrations can be attributed to the use in homes and gardens.

Polychlorinated Biphenyls (PCBs) results have shown the highest concentrations at sites 1 (Tembisa) and 2 (Ivory Park-Riverside Street) at values <1 µg/L. Polychlorinated Biphenyls are used in a numerous industrial and commercial applications including, electrical; hydraulic equipment such as plasticizers in paints, and plastics; and in pigments dyes, and carbonless copy paper. None of these industries/activities were observed near site 2, however, the disposal of old equipment containing PCBs may lead to environmental contamination through release into the air or transported into streams by run-off (EPA, 2019). Therefore,

92 the presence of these chemicals in water may emanate from PCBs containing products in the area. Although PCBs are considered as part of the dirty dozen, there are companies who still produce them and use them in their products to be used by the public or industries (Quinn et al., 2011). Machete and Shadung (2019) state that some of the chemicals such as OCPs are still manufactured in South Africa even after being considered toxic or banned. The continual use of banned pesticides was asserted by Quinn et al. (2011) to be due to challenges in regulating small companies as they are not registered under the chemical association; therefore, monitoring their compliance to the law is near impossible.

Semi-Volatile Organic Compounds (SVOCs) concentrations showed considerably low values than the wet season. Wet season results showed considerably high amounts of SVOCs at sites 4 (Clayville) and 5 (Olifantsfontein) with sites 1 – 3 (Tembisa and Ivory Park) depicting values below detectable levels. Semi-volatile Organic Compounds (SVOCs) are associated with pesticides and herbicides in agricultural activities, and industrial activity such as the production of rubber, dyes, cleaning agents, pharmaceuticals and chemicals used in textile and electronic manufacturing (Sun et al., 2014). Therefore, these chemicals are normally linked to agriculture residual and industrial effluent (Chen et al., 2012). As such, SVOCs concentrations show elevated concentrations at sites 4 and 5 which are sites surrounded by extensive industrial activity. As mentioned previously, there are two pharmaceutical companies located about 2 km east of site 4 (Clayville). There are also agriculture fields located to the west of site 4 and next to site 5 (Olifantsfontein). Wu et al. (2013) investigated the presence of SVOCs along the Yangtze River and Huaihe River (China) and found variations in the results between sampling sites with different anthropogenic activities. The results showed high values of SVOCs to be associated with areas of agricultural activity and chemical industries (Wu et al., 2013).

All phenolic compounds generally showed low concentrations for both season except for the compound phenol which depicted considerably high concentrations across all sites and with most sites showing similar values for both seasons. Sites 4 and 5 have indicated to have the highest concentrations of phenols for both seasons. Phenols can emanate from an array of sources which include industrial, domestic and agricultural sectors (Anku et al., 2017). Phenols are constituents of some pesticides and are also present in human and animal wastes (DWAF, 1996b). Phenols are used in the chemical industries, water treatment as well as wood and construction companies (Anku et al., 2017). Sites 4 and 5 are dominated by various industries which include construction and wood manufacturing companies near site 4. There is also the presence of a waste water treatment plant upstream of site 5. The mentioned industrial activities could probably be resulting to the heightened concentrations of phenols at these sites. Moreover, industrial activity appears to be a large contributor of 93 phenols from industrial effluents (Anku et al., 2017). As such, many studies were conducted in order to investigate and propose different methods of removing phenolic compounds in industrial wastewater (Ruixue et al., 2013; Villegas et al., 2016; Mu’azu et al., 2017).

5.2. SEDIMENT CHARACTERISTSICS

5.2.1. Physical characteristics of sediment

Sediment moisture percentage for the wet season showed to be generally higher than dry season moisture. The highest percentage was observed at site 3 for the wet season (21.6%) and site 1 for the dry season (24.5%). Moisture content can be defined as the quantity of water contained in soil (Marshak, 2008). Water content and porosity are important properties of sediments and there exists an intrinsic dependence between water content and porosity (Marshak, 2008). Porosity is the gap between soil particles which contains water and thus porosity can be a measure of water in the sediment (Nimmo, 2005). The relationship between porosity and water content can demonstrated by site 1 results. During the wet season, site 1 depicted fairly high water content (24%) compared to other sites due to the site’s dominance of high to medium sand which has higher ability to hold water than coarser sediments. During the wet season, site 1 was also amongst the top two highest with water content (19.5%) also due to the dominance in fine to medium sediments. Site 2 also depicted high water content for both seasons due to the grain sizes, although it contained bigger grain sizes that site 1. In chapter 3 and 4 it was indicated that South African Scoring System version 5 (SASS5) biomonitoring was not undertaken at sites 1 and 2 due to the stagnant nature of the water which allowed for the accumulation of finer sediments. Percentage organic content for the wet season showed minimal variations with a range of 1% - 2%. For the wet season, there were slight variations observed with a range of 1% - 4.4%. There appears to be no direct relationship between water content and organic content concentrations for the dry season, however, the wet season has shown a slightly direct and positive relationship between water content and organic content. Sites containing high water content also contained high organic content. A positive relationship between moisture content and organic content was also established by Tong et al. (2005). The study was conducted to analyse the characteristics of and the relationship between organic carbon and moisture content and the results illustrated a strong positive correlation between these two properties.

Grain sizes of sediment particles for the sites during wet and dry seasons sampling were sparsely distributed, however, they showed a large dominance of coarse sand particles (500 µm – 2 000 µm), except at site 1 which showed a general dominance of fine to medium sediments. Slow-moving or standing water are known for sediment deposition and settling of 94 sediment including fine sediment (Marsh and Fairbridge, 1999). Site 1 is therefore characterised by such sediments. Yang and Shi (2019) has opined that understanding sediment properties in the study of rivers is important and can shed a light on the processes of soil erosion and deposition. Among other sediment properties, grain size is one of the most important factors controlling river morphology and hydrodynamic conditions, as it provides important information on sediment transport and river ecology (Yang and Shi, 2019).

Sediment particle sizes have an important role to play in the level of entrapment of contaminants found in water. Porosity as a factor in grain sizes can affect the dissolution and the transfer of dissolved substances between sediment and water (Avnimelech et al., 2001). Finer sediments are more likely to absorb contaminants when compared to coarser sediments, and are therefore some of the major contributors to ecological degradation (FAO, 2019). Such contamination can have dire impacts of aquatic biota, particularly invertebrates that reside on the substrate. This can affect their feeding and respiratory processes due to unsuitable conditions and may lead to fatalities of such taxa (FAO, 2019).

5.2.2. Metals in sediment

Chemical analyses of sediment revealed the presence of metals in various concentrations with slight seasonal variations. Sediments are known for their ability to trap contaminants due to the presence of chemically active fractions of sediment associated with certain particle sizes (FAO, 2019). As such, many of the metals and persistent toxic organic contaminants are associated with sediments (FAO, 2019). Metals that appeared to be present in considerable amounts include aluminium, chromium, iron, and silicon. Copper and lead were also present in considerable amounts but their concentrations showed to be within Interim Sediment Quality Guidelines of the Canadian Environmental Quality Guidelines for sediment (2001), which means they were present in tolerable amounts. Aluminium showed concentrations above acute effect levels for the water results and also appeared to have heightened concentrations for the sediment results. Similar to the water results, site 4 appeared to have higher concentrations of aluminium for both seasons and these heightened levels are most likely attributed to the aluminium extrusion plant and steel manufacturing and distribution plant near site 4 which use aluminium.

Chromium showed high concentrations and revealed values that fell above probable effect levels (PELs) when compared to the Canadian Environmental Quality Guidelines for sediment (2001). Probable effect levels indicate the range within which adverse effects frequently occur (more than 50% adverse effects). Chromium concentrations were the highest at sites 4 for both wet and dry seasons. Chromium is a relatively scarce metal and 95 can be introduced into the environment through natural processes but mostly due to industrial activity (DWAF, 1996b). Chromium can be found in many forms with its ions taking various forms and also found as chromium salts (ATSDR, 2019). Various industries associated with chromium include electroplating, paint and dye manufacturing, as well as ceramics and glass industry (DWAF, 1996b). Various industries located to the west of site 4 are associated with the mentioned activities. There is tile manufacturing and distribution company and a tile wholesaler and distributor located 4 km and 2 km respectively, away from site 4. Relatively closely located to site 4 (about 1.5 km), there is also a thermal spraying company which applies metal alloy coating to various materials. These industries are probable contributors to the amounts of chromium at this site.

Iron concentrations were fairly high revealing to be higher in the dry season. Iron concentrations were generally the highest at site 5 (Olifantsfontein). Iron is considered an important micronutrient for all organisms as it is required in the respiratory enzymes for organisms, however, at high concentrations iron has toxic properties disturbing various enzymes (DWAF, 1996b). Iron may occur naturally in varying quantities in water depending on the geology of the rocks in the waters, however, it can also be introduced into the environment through various anthropogenic activities (WHO, 1996). Human activities that lead to the release of iron into the environment include mineral processing, sewage, the burning of coal and the corrosion of iron and steel (DWAF, 1996b). Iron is also used in the production of water pipes, steel manufacturing and petro-chemical industry (DWAF, 1996b). There is a roofing manufacturer located between site 4 and site 5. There is also a pipe manufacturer that supplies pipes, fittings, tanks and irrigation products nearby site 5. Various other industries around the site appeared be associated to the use of iron. All these activities are most likely responsible for the presence of iron in water.

Silicon concentrations were found to be the highest from all measured ions across all sites and for both seasons. These concentrations appeared to be the highest during the dry season than the wet season; however, there were slight variations between seasons. Site 5 appeared to generally have the highest concentrations of silicon for both seasons. Silicon is the most abundant element on the earth’s crust following oxygen and is largely found naturally in water through weathering processes (Lenntech, 2019). Silicon is however rare to find on its own, and is normally found on the earth’s surface as silica/silicon dioxide (SiO2) as it normally pairs with oxygen (EPA, 2001). Silica emanates from many sources including rocks and sand, construction materials and ceramics (EPA, 2001). The existence of several construction companies was noted upstream of site 5. There are also two tile manufacturing companies noted in the vicinity of site 5. These activities are most likely to be contributing to the heightened concentrations of this element. 96

5.2.3. Organic compounds in sediment

Organochlorine Pesticides (OCPs) were revealed to be present in considerable amounts with minimal seasonal variations. As stated previously, OCPs are among the persistent chemical compounds and resistant to degradation (Naidoo and Buckley, 2003). Therefore, they can be trapped and accumulate preferably in sediments than in water, as changes in the volume of water and its mobile nature can result in changes in concentrations of Persistent Organic Compounds (POPs) (USDHH, 2005). Aldrin, dieldrin, heptachlor, and chlordane were amongst the lowest concentrations at <2 µg/kg for both wet and dry seasons. DDT and its metabolites (DDE and DDD) were present in notable concentrations and generally showed to have high concentrations at sites 4 (Clayville) and 5 (Olifantsfontein). As previously stated, DDT is banned in South Africa, and its use is restricted only to the government for the control of pests like Malaria, lice and rats (Naidoo and Buckley, 2003). However, the use of DDT and other organochlorine pesticides still continues by industries, farmers (large scale and small scale) and the public (Machete and Shadung, 2019). These compounds were found in concentrations that were above probable effect levels (PELs) according to the Canadian Environmental Quality Guidelines (CEQG) (2001) for sediment. Probable effect levels (PELs) is a range within which adverse effects frequently occur (CEQG, 2001). The presence of agriculture fields to the west of site 4 and near site 5 has already been discussed in the previous sections. The presence of these agriculture activities could possibly result to the high concentration of these pesticides in sediment.

One notable OCP which showed higher concentrations (<20 µg/kg) across all sites and both seasons is gamma-hexachloro cyclohexane better known as lindane. Concentrations of lindane for all sites and both seasons appeared to fall above the PEL limit according to CEQG (2001). Lindane is not banned in South Africa and is currently registered and used as a common insecticide in agriculture as well as in domestic gardens (Quinn et al., 2011). Therefore, the high concentrations of these chemicals may be as a result of run-off from formal residential areas due to domestic use. A study conducted by Quinn et al. (2011) to investigate the levels of pesticides including lindane and DDT in sediments of the Vaal River and its tributaries revealed concentration notably lower than in the current study. The results showed lindane concentrations to range between 0.17 – 1.86 µg/kg, which is notably lower than the current study that recorded <20 µg/kg. DDT concentrations were also generally lower than the current study showing a range of 0.3 – 6.9 µg/kg, while the current study ranged between <2 – 19 µg/kg, with the highest recorded at sites near agriculture fields.

All sites for the wet and dry seasons showed PCB concentrations <11.7 µg/kg. These PCBs are considered as one of the dirty dozen and therefore their presence in the river’s sediment is cause for concern. A study undertaken by Samara et al. (2006) to determine the levels of PCBs in sediments of the Niagara River, New York, revealed that all sediments contained detectable amounts of PCBs ranging between 1.7 µg/kg and 124.6 µg/kg. The study revealed that the highest concentrations of PCBs were observed at a site located near a waste water treatment plant (WWTP) and a number of industries (Samara et al., 2006) with the rest of the sites showing varying concentrations. These results are in contrast with the current study’s results as all the sites showed constant concentrations <11.7 µg/kg despite differences in land-use activities and anthropogenic activities.

Semi Volatile Organic Compounds (SVOCs) were also noted to be present in mostly constant but in some instances varying amounts and with minimal variations between seasons. Polycyclic Aromatic Hydrocarbons (a group of SVOCs) were also present in significantly higher amounts than in the water. This is because Polycyclic Aromatic Hydrocarbons (PAHs) are immobile and inhibited from dissolving in water by their non-polar structures (Abdel-Shafy and Mansour, 2015). Polycyclic Aromatic Hydrocarbons generally showed of pattern of high concentration at sites 1–3 (Tembisa and Ivory Park townships). Although PAHs can occur naturally in the environment from natural burning or seepage of coal of oil deposits, anthropogenic factors such as the combustion of coal, oil, petrol and wood can lead to the generation of these compounds (Abdel-Shafy and Mansour, 2015). Therefore, activities such as industrial processes, automobile emissions, wood-burning stoves and other activities can lead to the introduction of PAHs into the environment (Nasher et al., 2013). As already mentioned, Tembisa and Ivory Park are townships densely populated, with urban/township activities taking place and have informal settlements. The high number of local taxis travelling within the township all day and daily transporting people in and around the township and outside the township could possibly be the result of high PAHs through exhaust emissions. There are a large number of informal settlements found within the townships whereby families use coal and paraffin stoves and the burning of wood for cooking and other heat requiring activities due to lack of electricity. All these mentioned activities could possibly result in the high concentrations of PAHs at these sites.

Sun et al., (2014) conducted a study to investigate the distribution and possible sources of SVOCs in small streams in Pearl River Delta, China. Concentrations of PAHs in sediment were generally high than found in the current study with minimal variations during wet season and dry season, showing a range of 29–1 300 µg/kg. The study established that the major sources of PAHs in sediment were vehicle emissions as well as the combustion of coal, grass and wood from the surrounding communities (Sun et al., 2014). 98

As has been the trend between water and sediment results, concentrations of phenolic compounds in sediment samples were notably higher than concentrations found in water. Phenol is readily adsorbed by soil and the adsorption reduces the rate of Phenol biodegradation in soil (CEQG, 2001). Phenolic compounds showed constant concentrations for the wet and dry seasons including phenol, which had the highest constant concentrations for all sites and both seasons (<400 µg/kg). When compared to the Canadian Environmental Quality Guidelines for sediment (2001), phenol concentrations were notably higher and surpassing the threshold effect concentrations set for this compound. These concentrations were similar throughout the different sampling sites with different surrounding land-use activities. As previously mentioned, phenol is a compound emanating from an array of sources. It is found in human and animal wastes, fertilizers, wood preservatives, paints and paint removers, textiles, pharmaceuticals (ointments, cold sore lotions and antiseptic lotions), perfumes and other plastics (CEQG, 2001). Additionally, Phenol is generally used as a disinfectant and antiseptic (CEQG, 2001).

The Kaalspruit runs through townships, suburbs, and industrial areas, thus these indicate the different land-use activities associated with the Kaalspruit at each location. The high concentrations of phenol from sites 1–3 (Tembisa and Ivory Park townships) could possibly be as a result of the use of pharmaceutical products, paints and dyes by communities in their homes. Also, phenol is also found in the gut of mammals and therefore excreted by humans and animals (DWAF, 1996b). Sewage discharges into the river from lack of sanitation in informal settlements located near sites 2 and 3 could also contribute to the concentrations of this compound at these sites. For sites 4 (Clayville) and 5 (Olifantsfontein), possible industrials that may contribute to the presence of phenols at these sites were already mentioned in the phenol section for water results and they include a construction and wood company near site 4; agriculture fields to the west of site 4 and near site 5; and a waste water treatment plant located upstream of site 5.

Phenol presence in intolerable amounts is cause for concern as these chemicals are toxic and have severe short-term and long-term effects on humans, animals and aquatic ecosystems in general (Anku et al., 2017). Phenols are persistent and bioaccumulative and are readily absorbed by animals and oxidized with other acids, where the absorption can lead to respiratory failure causing death (CEQG, 2001). Zhong et al. (2018) investigated the distribution potential of Phenols from Dagu Drainage River, Beitang Drainage River, and Yong-dingxin River in Tianjin, China. The results showed higher phenols concentrations from the Dagu Drainage River than the other two rivers. The high concentrations at the sites in the Dagu Drainage River were associated with a pesticide factory nearby one site along the river as well as domestic sewage and industrial discharges into the river as opposed to the 99 other two rivers. The study was concluded by establishing a higher ecological risk in the Dagu Drainage River as phenolic concentrations at toxic levels.

5.3. AQUATIC MACROINVERTEBRATES

The assessment of living organisms in fluvial environments is a widely known method for determining the condition or the health of rivers (Dickens and Graham, 2002). Macroinvertebrates are widely considered important organisms for bio-assessments due to their short life cycles largely reliant on seasons, their sedentary nature, ease of identification and visibility to the naked eye (Dickens and Graham, 2002). Therefore, macroinvertebrates are indicators of the health because they each have unique characteristics; some are sensitive to pollution and some are pollution tolerant (Chikodzi et al., 2017). Consequently, their presence in water can provide an indication as to whether the river is polluted or in good condition. Thus, the presence of pollution tolerant macroinvertebrates such as Oligochaeta, Culicidae, Chironomidae, Psychodidae, and Syrphidae, amongst others, can indicate that the water quality of that particular river is poor. Similarly, the presence of pollution sensitive macroinvertebrates such as Perlidae, Ephemeridae, Oligoneuridae, and Heptageniidae, amongst others, is considered as an indication of a less impacted river. However, it is important to note that pollution tolerant taxa can also be found in less polluted rivers (Chikodzi et al., 2017). Temperature, amongst other things, has been associated with seasonal variations in aquatic biota (Dallas, 2009). All organisms have a temperature range within which growth, reproduction and fitness are acquired (Vannote and Sweeney, 1980). Therefore, temperature outside the range of “optimum thermal regime” can affect various processes for aquatic organisms such as growth and geographical distribution, behaviour, tolerance to parasites and diseases and pollution (Dallas, 2009).

Water temperature is considered as an important factor in season patterns in the structure and function of aquatic biota including macroinvertebrates (Eady et al., 2013). Several studies conducted to investigate the effects of changing temperatures on macroinvertebrates assemblages found that macroinvertebrate communities generally decrease with increasing temperature (Hawkins et al., 1997; Durance and Ormerod, 2007; Chessman, 2009; Brucet et al., 2012; Floury et al., 2013). This is possibly due to a decline in families that favour colder waters (Chessman, 2009). These studies have however, reflected contrasting observations from the current study, whereby there was a perceived abundance of species in the warmer season when compared to the colder season. Therefore, factors such as changes in river flow may have contributed to the perceived seasonal variations in number of taxa observed.

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At site 3 (Ivory Park-Riverside street) there were three families sampled for both seasons, with more taxa sampled during wet season than dry season. The identified families at this site are species that are tolerant to pollution as they all have low sensitivity (Chikodzi et al., 2017). Chironomidae can be found in a range of environments; from pristine environments to polluted waters, as well as flowing or still waters (Gerhardt and Hribar, 2019). Although functional feeding groups (FFGs) were not part of the objectives of the study, it was interesting to observe the FFGs associated with the identified taxa. These are known as a classification based on food acquisition (Henriques-Oliveira et al., 2003). With that said, Chironomidae species fall within various functional feeding groups including gatherers, scrapers, shredders and predators (Gerhardt and Hribar, 2019). Oligochaeta species are collector-gatherers and are most them move over small spaces of substrata although a few are known to be swimmers (Benbow, 2009). High abundance of Oligochaeta is normally associated with eutrophic environments with low dissolved oxygen as many of them can withstand long periods under anoxic conditions (Benbow, 2009). Which was the case with site 3, as it was established to be hypertrophic together with all the sites. Syrphidae species are also collector-gatherers like Oligocheata and some Chironomidae species are commonly found in sediment of shallow waters in highly polluted and low oxygen water (Benbow, 2009). The dry season saw a dominance of collectors than the wet season. This is similar to what Masese et al. (2014) found on a study comparing functional feeding groups in Kenyan highland streams.

Site 4 (Clayville) have indicated to have more taxa sampled than sites 3. Although the same number of families was identified from both seasons, the wet season however, had a lower ASPT compared to the dry season because the wet season had more pollution tolerant taxa than the dry season. Average score per taxa (ASPT) can be a reflection of taxa sensitivity and therefore reveal the pollution status of the river (Chikodzi et al., 2017). Therefore, even if low number of taxa was sampled from a site, ASPT may not be affected if the sampled taxa have appropriate sensitivity (Dickens and Graham, 2002). Moreover, according to Chutter (1998), ASPT is a better indicator of the health of good rivers than SASS score. There was no dominant functional feeding group (FFG) during the wet season with the observed FFGs being scrapers, collectors and possibly shredders and predators from Chironomidae as they are associated with several feeding groups. For the dry season, predators were the dominant FFG with the decrease of other FFG species. This observation was also made by Masese et al. (2014) where it was noted that dominance in predators leads to the decrease of other taxa. This is largely because predators feed on other macroinvertebrates which further leads to the decreased number of taxa (Henriques-Oliveira et al., 2003). Masese et

101 al. (2014) further assert that predator overabundance indicates strong top-down control in streams.

Site 5 (Olifantsfontein) generally revealed more taxa than all the sites with only two families (Oligochaeta and Chironomidae) identified from the preceding sites, and with many of the taxa identified during wet season than dry season. However, the identified taxa at this site are pollution tolerant with low sensitivity, and with similar sensitivity values to taxa identified at the other sites, hence the ASPT score varied slightly from the other ASTPs (2.7 for the wet season with higher number or taxa, and 1 for the dry season). This site showed dominance of the FFG of collectors. Masese et al. (2014) made an observation of an overabundance of collectors from sites that generally showed higher conductivity and turbidity, and which are located next to agricultural fields. Similarly, with the current study, site 5 generally depicted high values for Electrical Conductivity (EC) and the contribution of the surrounding agriculture activities to the high levels of EC and Total Dissolved Solids (TDS), and nutrients has already been discussed. Other studies have also illustrated the direct relationship between water quality parameters such as EC-TDS and nutrients (Jun et al., 2011; Camargo, 2019).

5.4. HABITAT ASSESSMENT

According to Dickens and Graham (2002) various factors such as habitat quality, quantity and diversity are important and should be incorporated with SASS results in order to make SASS results meaningful, because these factors can influence SASS results. Less biotic diversity and therefore lower SASS scores can be as a result of poor habitat diversity. Integrated Habitat Assessment System (IHAS) is a commonly-used macroinvertebrate habitat assessment technique in South Africa (Oliis et al., 2004). Integrated Habitat Assessment System is based on the sensitive nature of SASS to the availability of macroinvertebrate habitats, also known as biotopes, and therefore, a positive relationship is always expected between SASS results and IHAS results. The need for invertebrate habitat assessment was eminent following the identification of physical habitat structure as one of the factors affecting ecological integrity and that bioassessment studies should include some form of habitat assessment (Oliis et al., 2004). Moreover, this assessment is required in order to draw a conclusion as to whether biological degradation is caused by physical habitat or water quality.

As a result, habitat assessment was undertaken on the sites where SASS5 was undertaken in order to understand the possible effects of habitat availability on SASS results. However, IHAS was also undertaken at sites where SASS5 was not conducted in order to understand the potential habitat quality of the all sites. Therefore, habitat results for site 1 and 2 showed 102 that these sites received an IHAS class of D depicting poor habitat availability. These sites were dominated by gravel, sand and mud (GSM) biotope for both seasons, with sand being the dominant one in both sites. The dominance of sand at these sites was established to the stagnant nature of the water allows for the accumulation of sediment (FAO, 2019).

Site 3 and appeared to fall under IHAS class C (fair/adequate) which indicates moderate modification of habitat. However, this site revealed to have the lowest number of taxa when compared to the other sites. It has been shown that good habitat diversity generally leads to good biotic diversity and consequently, good SASS score (Dickens and Graham, 2002). However, the current study showed contrasting results to that. This may suggest that other factors such as flow dynamics and water quality may have contributed to the poor diversity and abundance of identified taxa at this site. Maul et al. (2004) investigated the influence of river habitat and water quality on macroinvertebrates at the streams of Mississippi and the results showed relatively similar abundance of macroinvertebrates even between sites of different habitat diversity. Results of the study suggested that other water quality parameters such as TDS, phosphorus, and conductivity were important variables in structuring macroinvertebrate communities (Maul et al., 2004). Therefore, water quality is suggested to be a determinant factor in the poor abundance of macroinvertebrates for this site, as water quality results have already indicated that the site is polluted.

Site 4 also fell within IHAS class C (fair/adequate) class indicating moderate modification in habitat quality. SASS score for this site was relatively low, although higher than sites 3, indicating poor macroinvertebrates diversity and consequently low SASS scores. This site shares the same conditions as site 3 whereby the habitat score appeared to be better than the actual identified macroinvertebrate communities which was also reported in other studies (Maul et al, 2004). IHAS results has showed site 4 to be characterised by the dominance of the stones habitat. Stones habitat is commonly associated with predators and the SASS results have also revealed the dominance of predators from site 4.

Finally, site 5 fell within IHAS class D (Poor) which denotes notable modifications to habitat. Site 5 has shown a general dominance of GSM biotope. SASS has also revealed the general dominance of collectors identified at site 5 which are commonly associated with GSM as they are known for collecting food on stream bottom, mostly sediment. Interestingly, site 5 revealed to have the highest number of identified taxa even though the habitat quality showed a poor class. The high number of taxa can be attributed to the high abundance of collectors at this site as a result of high EC, TDS and nutrients as established by Masese et al. (2014). This misalignment between SASS5 and IHAS results proves the need for

103 conducting other assessments such as water quality when investigating macroinvertebrate assemblages and their possible impacts.

This discussion has indicated how the investigated pollutants are mostly present throughout the whole segment of the Kaalspruit and that some contaminants are concentrated at and higher at various sites as a result of associated land-use activities. The surge of chemical pollutants in sediment was also observed with most pollutants of concern concentrated around the industrial areas. SASS5 results also revealed poor diversity and abundance of present taxa that are all tolerant to pollution indicating that the system is polluted. Subsequently, IHAS assessment has also revealed habitat conditions that are poor for most of the sites with the rest of the sites in fair conditions, but still modified, which supports the poor abundance of macroinvertebrates in the river. The observed results from all components are cause for concern as they indicate that the stream is negatively impacted as a result of the surrounding activities.

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CHAPTER 6

CONCLUSIONS AND RECOMMENDATIONS

6.1. CONCLUSION

The obtained water quality, sediment quality, and macroinvertebrate and habitat results have revealed a multitude of findings and observations which provides a demonstration of the overall health of the Kaalspruit. Water quality results have indicated intolerable and thus toxic concentrations for many of the water quality parameters. Although pH and electrical conductivity were within acceptable and tolerable ranges, other parameters such as DO were very low and fell within intolerable ranges indicating unsuitable conditions for aquatic life. This provides a valid justification to the absence of common aquatic organisms such as fish which rely on dissolved oxygen to live. The system also showed hypertrophic conditions from all the sites with high nutrient loading present at sites near agriculture fields and a WWTP. Faecal coliform concentrations were also observed and appeared to be heightened next to informal settlements. This has been commonly seen in sites situated near or close informal settlements (Gerhardt, 2000; Munyika et al., 2014; Chikodzi et al., 2017).

Metal concentrations were found both in water and in sediment, with sediment results showing notably high concentrations. The higher concentrations of metals in sediment are attributed to the capability of sediment to absorb contaminants (FAO, 2019). Metal concentrations in water were mostly observed in minimal amounts with most of them falling below detectable limits and some of them falling within tolerable limits for aquatic ecosystems according to guidelines stipulated by DWAF (1996b). However, a few exceptions such as iron and zinc showed concentrations above tolerable limits with potentiality to have chronic and acute effects to aquatic ecosystems. According to DWAF (1996b), iron tends to be toxic at high concentrations and thus its concentrations should not be allowed to reach toxic levels. Metals in sediment showed considerably higher amounts with wet season concentrations generally higher than dry season concentrations. Aluminium, chromium, iron and silicon had notably high concentrations for all seasons with dry season increases. For both water and sediment results, sites that revealed generally higher concentrations of these metals are sites 4 and 5 which are surrounded by industrial areas. Elevated concentrations of aluminium and chromium are toxic to a wide range of organisms (DWAF, 1996b).

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Organic compounds investigated also showed a similar trend as metals by mostly being heightened in sediment than in water with slight to no seasonal variations perceived. Organochlorine pesticides (OCPs), phenolic compounds and polychlorinated biphenyls (PCBs) were present in considerable amounts, particularly in sediments. High concentrations of OCPs, particularly DDT were generally observed at sites 4 and 5, which were attributed to the agriculture fields that are found close to these particular sites, as these pesticides are normally associated with these areas (Naidoo and Buckley, 2003; Quinn et al., 2011). Semi-volatile Organic Compounds (SVOCs) were also present in considerable amounts with minimal seasonal variations. Semi-volatile Organic Compounds (SVOCs) are commonly associated with coal, petroleum and wood combustion (Abdel-Shafy and Mansour, 2015), and their enhanced concentrations at sites 1-3 were linked to vehicle emissions, coal and paraffin stove stoves from communities in Tembisa and Ivory Park townships.

SASS5 results showed poor species diversity from all the sampled sites, with a notable trend of high number of taxa discovered during the wet season than the dry season. All the discovered taxa were pollution tolerant with low sensitivity, which generally led to low SASS scores and ASTP values for all the sites sampled in both seasons, indicating that the system is polluted. The complementing IHAS results indicated poor habitat quality for most of the sites with only two sites showing fair/adequate conditions, which also denotes some modification to existing habitats.

The attained results have provided an illustration of the poor state that the Kaalspruit is in. The results have shown that the ecological health of the Kaalspruit is compromised, and the aquatic environment is highly impacted. Key illustrators of that include water quality parameters that are mostly within intolerable limits indicating toxicity, most contaminants in sediments showing toxic levels, and the SASS5 results only showing pollution tolerant taxa indicating that the system is highly polluted. This provides justification of the need for rehabilitative action of the system and the development of a suitable management plan that will address the identified problems of water quality and poor habitat. The plan should also address socio-economic factors in the surrounding areas such as poor infrastructure and poor service delivery that are directly and indirectly leading to the deteriorating state of the river. The key focus of the plan should be the improvement of water quality, not only for ecosystem health but also for the health of the surrounding communities since the current state of the river has the potential to have dire health impacts on the local community. The involvement of the community, industry management and other stakeholders should also be enforced in order for rehabilitation to be successful.

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6.2. RECOMMENDATIONS FOR A MANAGEMENT PLAN

The influx of different types of pollution into the Kaalspruit has indicated the need for effective rehabilitation and future management of the watercourse. The National Water Act (1998) has placed priority to the water reserve which includes the ecological reserve for the protection of aquatic ecosystems; however, the poor ecological state of the river does not appear to be performing its basic ecological function of supporting aquatic life and ecosystems in general. Rehabilitation is a means of attempting to return the current conditions of a stream to historic conditions or better quality (Nawn, 2004). The water quality results provided an understanding of the current stream conditions and a clear indication of the need for rehabilitation and management planning. Therefore, the water quality results obtained for the current study were the first step in the development of the management plan. Subsequently, for a water resource management plan to be effective it should honour the principles of Integrated Water Resources Management (IWRM) which recognises the importance of stakeholder and community involvement in water management (Plummer and Stacey, 2000). Therefore, rehabilitation and management that embodies the elements of IWRM is necessary for the Kaalspruit and will be proposed in this section.

These recommendations for management include various aspects and possible phases for rehabilitation and management of the Kaalspruit in an attempt to improve the overall health of the stream. The plan includes the following components:

1. Phase 1: Institutional arrangements 2. Phase 2: Stakeholder engagement 3. Phase 3: Rehabilitative measures/action a) Improvement of water quality b) River banks stabilization 4. Phase 4: Education and awareness programmes and restoration projects 5. Phase 5: Monitoring

Phase 1: Institutional arrangements

Kaalspruit falls under the jurisdiction of two municipalities; that is, Ekurhuleni Metropolitan Municipality (EMM) and City of Tshwane Metropolitan Municipality (CTMM), therefore there has to be collaboration between the two municipalities to share development and management responsibilities. The Environmental Resources and Waste Management department from the EMM and CTMM should spearhead the management programme for the Kaalspruit as these departments are responsible for issues that affect the environment (Ekurhuleni, 2019). The Waste Management division will also have a role to play as they will 107 address the waste problem associated with the river and largely contributing to the deteriorating state of the water quality. Subsequently, water quality problems of the Kaalspruit stem from multiple factors and therefore inter-department collaboration will prove to be vital. Therefore, there will have to be collaboration also with the Department of Human Settlement and the Department of Water and Sanitation. This collaboration will address the problems of sewage waste coming from informal settlements.

Phase 2: Stakeholder engagement

As already stated, stakeholder engagement is an integral part of Integrated Water Resources Management (IWRM). The inclusion of interested and affected parties in the management of a natural resource is widely practiced and often considered necessary for successful water resources management (Plummer and Stacey, 2000; van Koppen et al., 2007; Day, 2009; Carr et al., 2012; Megdal, et al., 2017; Tantoh and Simatele, 2017). Community consultation, inclusiveness, communication and transparency are the most important elements in ensuring the success undertaking of the management programme (Plummer and Stacey, 2000). The importance of inclusivity in water resources management was also documented by Poricha and Dasgupta (2011) in Cuttack, India. In order to improve their water and sanitation problems in the area, communities were grouped and a project plan was designed in a consensual manner with the aim of facilitating public participation (Poricha and Dasgupta, 2011). This created and solidified the relationship between the people and water resources, which leads to better management and maintenance of water resources. Communities possess local knowledge on many natural resources in their areas, which denotes that their input is invaluable as they will provide information and knowledge that is not known to government officials or even experts (Carr et al., 2012). A study conducted by Mashazi et al. (2019) on evaluating perceptions, attitudes and the community’s willingness to participate in the management of the Kaalspruit has revealed that the communities surrounding the Kaalspruit are aware of the poor state of the river and they are willing to participate in rehabilitative actions for the river.

Objectives and activities of the stakeholder engagement should include:

➢ Initial communication • Initial consultation with community leaders (ward councillors) of surrounding areas. • Meetings between ward councillors and their respective communities. • Advertisement of stakeholder meetings through local radio station, local newspaper, and placement of advertisements at local places such as libraries and schools. • Meetings with communities at large and approach of industry management.

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➢ Actions • Establishment of a water management committee comprised of representatives from government, community, industry, and local NGOs. • Assignment of roles and responsibilities to committee members. • Generation of a management programme to be implemented.

Phase 3: Rehabilitative measures/action

a) Improvement of water quality The results of the current study have already indicated that the water quality of the Kaalspruit is in an unacceptable state, thus improving water quality should be top priority of the project. Improving water quality will lead to improved ecological health and possibly alleviate diseases that may be associated with poor water quality. Moreover, improving water quality also means improving other service deliver shortfalls that lead to the discharge of sewage and disposal of waste into the river. Also, collaboration with industries to ensure industrial waste is treated before discharged into the river will be necessary. Addressing these issues will lead to improved water quality and decrease of a wide range of contaminants in the river and possibly aim to improve it to mesotrophic levels (moderate levels of nutrients). The following actions should form part of improving water quality:

• Placement of litter traps along the Kaalspruit: Waste from the townships of Tembisa and Ivory Park are one of the leading causes of poor water quality in the Kaalspruit. Large amounts of litter in the water and on the banks were observed during site visits for both wet season (September 2018) and dry season (June 2019). The placement of such structures will reduce the amount of litter that ends up into the water. Maintenance and cleaning of these structures should be given priority to ensure their efficient functioning. • Placement of sediment traps: The Kaalspruit receives large amounts of sediment from erosion and soil run-off which leads to sediment loading into the river. Therefore, the installations of such structures will prohibit large amounts of sediment from entering the river. • Improve sanitation services: Sewage discharges into the river from lack of sanitation services, particularly from informal settlements, has contributed immensely to the poor state of the river and high levels of faecal coliforms found in the river. The local departments of Water and Sanitation can work together to address sanitation problems associated with the river through the development of a plan to assist the said communities and set short-term and long-term goals as follows:

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o Short term goals: Provide temporary sanitation facilities including mobile toilets to informal settlements in the area and also develop proper strategies to collect sewer from the supplied toilets. o Long term goals: Place informal settlers on a government housing list or programme which will place them in line to being beneficiaries of the Reconstruction and Development Programme (RDP) to receive government houses in the near future. • Improve waste management services: One of the contributing factors to large amounts of waste in the river and river banks is inadequate waste collection services in the townships, including lack of formal dumpsites or large skip bins that can be placed strategically at street corners. Such services should be included in the waste management plans. Poor solid waste removal and illegal waste sites in Tembisa and Ivory Park townships has been reported as some of the contributing factors to solid waste (litter) pollution in the Kaalspruit and also causing solid waste problems in downstream rivers such as the Hennops River (Tembisan, 2017; Hennops Blue, 2018) • Proper treatment of industrial effluent: The industrial area of Clayville and Olifantsfontein, and the WWTP in Olifantsfontein have shown to be large contributors of nutrients, metals and chemical compounds from their operations. Proper wastewater treatment from the WWTP and industrials should be ensured; companies without proper treatment processes should be required to develop and implement them. The Ganga River in India is a good case study which provides a documentation of the success of several of the above-mentioned measures for improving water quality (Sharma, 1997). This river was plagued by pollution stemming from sedimentation, erosion, urban waste discharges (including sewage) and solid waste litter into the river (Sharma, 1997). In order to rehabilitate the river; a plan was developed and multiple projects were established which include the provision of low-cost sanitation and solid waste facilities and the instalment of litter traps to prevent future litter in the river (Sharma, 1997). These projects led to the perceived improvements in water quality of the Ganga River. Another study conducted by Rietveld et al. (2014) has demonstrated how urban water management can be achieved through systems approaches. The study presents the case of Surat city in India which was known as the least hygienic cities in the country with inadequate waste disposal and sanitation, and the general environment in a poor state including water quality of surface waters. The city took an inter-sectoral approach to these problems and some of the actions taken include improving sanitation and drainage infrastructure (Rietveld et al., 2014). Amongst many of the outcomes of these interventions, there was a perceived reduction in 110 waterborne diseases (Rietveld et al., 2014). Moreover, there were improvements in methods used to treat effluent from sewage treatment plants. This resulted in less polluted waste water being discharged into the river (Rietveld et al., 2014). The installation of sediment traps was also documented to be effective in reducing sediment input into the Western Rother catchment and preserving topsoil (Wright, 2014). Moreover, Armitage and Rooseboom (2000) have also proclaimed the usefulness of litter traps in removing waste from streams and storm water conduits. The study presented a case of the Robinson Canal in Johannesburg and its effectiveness in trapping litter. The structure has proven to have high efficiency and traps all kinds of litter including sediment such as stones and bricks (Armitage and Rooseboom, 2000). This has proven to reduce sediment load in water that enters the Klipspruit (Armitage and Rooseboom, 2000).

b) River banks stabilization Stream bank erosion can be avoided by the placement of vegetation (traditional method) which has the ability to stabilize stream banks (Admiraal, 2007). However, stream bank stabilization has evolved to become an engineering focus which led to different methods being used in addition to the traditional vegetation method (Admiraal, 2007). The following are proposed stream banks stabilization methods for the Kaalspruit:

• Grass buffers: Buffers are structures that help to control erosion by obstructing sediment as well as stabilizing stream flow (Admiraal, 2007). This will assist in dealing with the sedimentation problems experienced in the Kaalspruit. • Mattresses: Mattresses made of fibre are created to protect in-situ soil by keeping it intact and trapping sediment while allowing water to permeate through (Hayes et al., 2000). • Gabions (rip rap): These are blankets consisting of rock material placed at stream banks in order to protect them against erosion. The installation of such structures normally requires grading of the bank to appropriate slope and then the bed is lined (Admiraal, 2007). • Brush fences live cutting: These are made lacing vegetation through the spaces of a wire fence in order to stabilize the river banks (Byram, 2002). The branches can also be used inside the fences in order to reduce run-off and trap sediment (Byram, 2002). • Fibre bags: Fibre bags are cost-effective and can be placed in low velocity interventions and over large surface areas (Hayes et al., 2000).

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Phase 4: Community initiatives

a) Environmental education and awareness programmes An environmental education and awareness programme should be developed and run by the water management committee that represents the community and allow for the participation of other community members especially unemployed youth for job creation, youth empowerment and skills development. The aim of this programme should be to promote community and ward-based environmental management and education. This may include education on environmental aspects as a whole such as, amongst others, waste management and water resources management. Activities and functions of this programme may include:

• Dissemination of environmental information to public places such as schools, libraries and community halls. • The establishment of environmental education sessions at schools held weekly, monthly or quarterly. • Coordination of environmental projects, campaigns and events.

b) Clean-up campaigns • Collaboration with the environment and culture sector of the Expanded Public Works Programme can be established for the joint undertaking of different clean-up campaigns around the river.

Phase 5: Monitoring

Every action and implementation should be followed by monitoring. There should be a development of an expertly maintained water quality programme to monitor the improvement of water quality in the river. Additionally, episodic monitoring of the state of industrial effluent will be required.

The proposed management actions have great potential to improve the state of the Kaalspruit. Addressing the key socio-economic factors such as lack of sanitation and poor waste collection that directly or indirectly contribute to the poor state of the Kaalspruit is of strong importance as improvement in these services can lead to improvement in water quality. Moreover, the involvement of the affected communities including industries can be beneficial to the rehabilitation project as they possess local knowledge and can therefore, make valuable contributions and suggestions to solving the water quality problems in the area as they are directly affected by the state of the river. Education and awareness are also

112 crucial in improving the state of the river because informed and knowledgeable people make informed decisions and may be able to act responsibly. Finally, constant monitoring of the state of the river essential to ensure that there is indeed improvement in the water quality.

6.3. RECOMMENDATIONS FOR FURTHER STUDIES IN THE KAALSPRUIT.

a) The current study has discovered the presence of various pollutants such as metals and chemical compounds mostly in concentrations that are not tolerable for aquatic ecosystems, denoting toxicity to some degree. It is therefore recommended that a toxicity study be conducted to investigate the degree of toxicity of water in the Kaalspruit. The results of the study may contribute to making a hazard assessment from the concentrations of the pollutants found in water and the resulting effects of exposure to aquatic communities.

b) It is also recommended that further studies be conducted on the wetlands that are found around the Kaalspruit, the degree of impact experienced by the identified wetlands and possible mitigation and rehabilitation measures.

c) It is further recommended that a study that evaluates the knowledge, attitudes and perceptions of secondary school learners on waste and water management be conducted at schools that are situated in townships were the Kaalspruit is located. This study is necessary as it will provide an understanding of the level of knowledge of students about natural resources and the environment and their willingness to participate is natural resources management. It will also be beneficial to the education and awareness programmes and campaigns to be developed in these areas by giving positive input and guidance as to which aspects to include in the programmes and campaigns and which gaps are to be filled by the programmes.

d) Finally, an extension of the investigation is also desirable for the determination of the plastics and microplastics dispersed in the river and the degree of impacts they have on the Hennops River and subsequently the Centurion Lake.

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APPENDICES

Appendix 1: Metals measured in the Kaalspruit water during wet season sampling (September 2018). Values were compared with the DWAF guidelines (1996b).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Ag mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Al mg/L 0.204 0.263 0.374 0.109 0.191 As mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Au mg/L <0.010 <0.010 <0.010 <0.010 <0.010 B mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Ba mg/L 0.133 0.137 0.132 0.072 0.058 Be mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Bi mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Ca mg/L 43 48 45 47 35 Cd mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Ce mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Co mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Cr mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Cs mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Cu mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Dy mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Er mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Eu mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Fe mg/L 1.54 1.96 2.21 0.719 0.695 Ga mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Gd mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Ge mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Hf mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Hg mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Ho mg/L <0.010 <0.010 <0.010 <0.010 <0.010 In mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Ir mg/L <0.010 <0.010 <0.010 <0.010 <0.010 K mg/L 15.5 16.8 14.8 7.9 16.6 La mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Li mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Lu mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Mg mg/L 12 14 13 22 13 Mn mg/L 0.610 0.740 0.759 0.601 0.322

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Appendix 1: Metals measured in the Kaalspruit water during wet season sampling (September 2018). Values were compared with the DWAF guidelines (1996b) (continued). Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Mo mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Na mg/L 86 89 73 42 84 Nb mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Nd mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Ni mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Os mg/L <0.010 <0.010 <0.010 <0.010 <0.010 P mg/L 1.72 2.78 1.61 1.19 1.20 Pb mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Rb mg/L 0.010 <0.010 0.018 <0.010 0.010 Sb mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Sc mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Se mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Si mg/L 10.5 10.5 9.8 11.4 8.1 Sr mg/L 0.093 0.086 0.099 0.066 0.062 Ti mg/L 0.042 0.036 0.037 0.022 0.026 U mg/L <0.010 <0.010 <0.010 <0.010 <0.010 V mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Zn mg/L 0.104 0.211 0.038 0.040 0.024

Appendix 2: Metals measured in the Kaalspruit water during dry season sampling (June 2019). Values were compared with the DWAF guidelines (1996b).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Ag mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Al mg/L 0.143 0.281 0.197 0.120 0.168 As mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Au mg/L <0.010 <0.010 <0.010 <0.010 <0.010 B mg/L 0.011 0.014 0.021 <0.010 <0.010 Ba mg/L 0.075 0.072 0.052 0.049 0.049 Be mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Bi mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Ca mg/L 41 40 33 48 41 Cd mg/L <0.010 <0.010 <0.010 <0.010 <0.010

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Appendix 2: Metals measured in the Kaalspruit water during dry season sampling (June 2019). Values were compared with the DWAF guidelines (1996b) (continued). Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Ce mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Co mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Cr mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Cs mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Cu mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Er mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Eu mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Fe mg/L 1.00 0.990 0.709 0.618 0.419 Ga mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Gd mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Ge mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Hf mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Hg mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Ho mg/L <0.010 <0.010 <0.010 <0.010 <0.010 In mg/L <0.010 <0.010 <0.010 <0.010 <0.010 K mg/L 8.4 9.8 10.6 9.8 17.7 La mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Li mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Lu mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Mg mg/L 11 11 10 20 14 Mn mg/L 0.506 0.497 0.389 0.518 0.277 Mo mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Na mg/L 52 55 44 56 88 Nb mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Nd mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Ni mg/L <0.010 <0.010 <0.010 <0.010 <0.010 P mg/L 0.621 0.998 2.49 0.973 1.53 Pb mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Rb mg/L <0.010 <0.010 0.010 <0.010 0.012 Sb mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Sc mg/L <0.010 <0.010 <0.010 <0.010 <0.010 Si mg/L 11.1 10.7 6.5 14.1 12.2 Sr mg/L 0.132 0.124 0.125 0.085 0.074 Ti mg/L <0.010 <0.010 0.028 <0.010 <0.010 Zn mg/L 0.022 0.038 0.042 0.030 0.088

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Appendix 3: Organochlorine pesticides measured in the Kaalspruit water for the wet season sampling (September 2018).

Site unit Alpha- Beta- Gamma Delta- Alpha- Gamma- Aldrin Dieldrin Endrin Heptachlor Heptachlor Methoxy- 4-4'- 4-4'- 4-4'- number HCH HCH -HCH HCH Chlordane Chlordane Epoxide chlor DDD DDE DDT Isomer B Site 1 µg/L <0.1 <2 <1 <2 <0.1 <0.1 <0.1 <0.2 <1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 Site 2 µg/L <0.1 <2 <1 <2 <0.1 <0.1 <0.1 <0.2 <1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 Site 3 µg/L <0.1 <2 <1 <2 <0.1 <0.1 <0.1 <0.2 <1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 Site 4 µg/L <0.1 <2 <1 <2 <0.1 <0.1 <.01 <0.2 <1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 Site 5 µg/L <0.1 <2 <1 <2 <0.1 <0.1 <0.1 <0.2 <1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

Appendix 4: Organochlorine pesticides measured in the Kaalspruit water for the dry season sampling (June 2019).

Site unit Alpha- Beta- Gamma Delta- Alpha- Gamma- Aldrin Dieldrin Endrin Heptachlor Heptachlor Methoxy- 4-4'- 4-4'- 4-4'- number HCH HCH -HCH HCH Chlordane Chlordane Epoxide chlor DDD DDE DDT Isomer B Site 1 µg/L <0.1 <2 <1 <2 <0.1 <0.1 <0.1 <0.2 <1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 Site 2 µg/L <0.1 <2 <1 <2 <0.1 <0.1 <0.1 <0.2 <1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 Site 3 µg/L <0.1 <2 <1 <2 <0.1 <0.1 <0.1 <0.2 <1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 Site 4 µg/L <0.1 <2 <1 <2 <0.1 <0.1 <0.1 <0.2 <1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 Site 5 µg/L <0.1 <2 <1 <2 <0.1 <0.1 <0.1 <0.2 <1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

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Appendix 5: Values for Polychlorinated Biphenyls (PCBs) determined in water from the wet season sampling (September 2018).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Trichlorobiphenyls PCB 28 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 44 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 49 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 52 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 60 µg/l <1 <1 <0.1 <0.1 <0.1 Tetrachlorobiphenyls PCB 66 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 70 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 74 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 77 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 82 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 87 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 99 µg/l <1 <1 <0.1 <0.1 <0.1 Pentachlorobiphenyls PCB 101 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 105 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 114 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 118 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 126 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 128 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 138+158 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 153 µg/l <1 <1 <0.1 <0.1 <0.1 Hexachlorobiphenyls PCB 156 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 166 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 169 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 170 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 180 µg/l <1 <1 <0.1 <0.1 <0.1 Heptachlorobiphenyls PCB 183 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 187 µg/l <1 <1 <0.1 <0.1 <0.1 PCB 189 µg/l <1 <1 <0.1 <0.1 <0.1

µg/l <10 <10 <1 <1 <1 Estimated Total PCBs

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Appendix 6: Values for Polychlorinated Biphenyls (PCBs) determined in water from the dry season sampling (June 2019).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Trichlorobiphenyls PCB 28 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 44 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 49 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 52 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 60 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 Tetrachlorobiphenyls PCB 66 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 70 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 74 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 77 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 82 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 87 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 99 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 Pentachlorobiphenyls PCB 101 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 105 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 114 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 118 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 126 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 128 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 138+158 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 153 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 Hexachlorobiphenyls PCB 156 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 166 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 169 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 170 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 180 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 Heptachlorobiphenyls PCB 183 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 187 µg/l <0.1 <0.1 <0.1 <0.1 <0.1 PCB 189 µg/l <0.1 <0.1 <0.1 <0.1 <0.1

µg/l <1 <1 <1 <1 <1 Estimated Total PCBs

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Appendix 7: Semi-volatile organic compounds measured in the Kaalspruit water for the wet season sampling (September 2018).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Naphthalene µg/L <0.1 <0.1 <0.1 <1 <1 Acenaphthene µg/L <0.1 <0.1 <0.1 <1 <1 Acenaphthylene µg/L <0.1 <0.1 <0.1 <1 <1 Fluorene µg/L <0.1 <0.1 <0.1 <1 <1 Phenanthrene µg/L <0.1 <0.1 <0.1 <1 <1 Anthracene µg/L <0.1 <0.1 <0.1 <1 <1 Fluoranthene µg/L <0.1 <0.1 <0.1 <1 <1 Polycyclic Aromatic Pyrene µg/L <0.1 <0.1 <0.1 <1 <1 Hydrocarbons Benzo(a)anthracene µg/L <0.1 <0.1 <0.1 <1 <1 Chrysene µg/L <0.1 <0.1 <0.1 <1 <1

Benzo(b+k)fluoranthene µg/L <0.1 <0.1 <0.1 <1 <1

Benzo(a)pyrene µg/L <0.1 <0.1 <0.1 <1 <1

Benzo(g,h,i)perylene µg/L <1 <1 <1 <10 <10 Dibenz(a,h)anthracene µg/L <5 <5 <5 <50 <50 Indeno(123-cd)pyrene µg/L <1 <1 <1 <10 <10 1,2-Dichlorobenzene µg/L <1 <1 <1 <10 <10 Chlorinated 1,3-Dichlorobenzene µg/L <1 <1 <1 <10 <10 Compounds 1,4-Dichlorobenzene µg/L <1 <1 <1 <10 <10 2-Chloronaphthalene µg/L <1 <1 <1 <10 <10 Hexachlorobenzene µg/L <1 <1 <1 <10 <10

Hexachloroethane µg/L <1 <1 <1 <10 <10

1,2,4-Trichlorobenzene µg/L <1 <1 <1 <10 <10 4-Chlorophenylphenyl µg/L <1 <1 <1 <10 <10 ether* 4-Bromophenylphenyl µg/L <1 <1 <1 <10 <10 ether Di-n-butyl phthalate µg/L <10 <10 <10 <100 <100 Phthalates Butyl benzyl phthalate µg/L <10 <10 <10 <100 <100 Bis(2-ethylhexyl) µg/L <10 <10 <10 <100 <100 phthalate

134

Appendix 8: Semi-volatile organic compounds measured in the Kaalspruit water for the dry season sampling (June 2019).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Naphthalene µg/L <0.1 <0.1 0.1 <0.1 <0.1 Acenaphthene µg/L <0.1 <0.1 <0.1 <0.1 <0.1 Acenaphthylene µg/L <0.1 <0.1 <0.1 <0.1 <0.1 Fluorene µg/L <0.1 <0.1 <0.1 <0.1 <0.1 Phenanthrene µg/L <0.1 0.1 <0.1 <0.1 <0.1 Anthracene µg/L <0.1 <0.1 <0.1 <0.1 <0.1 Fluoranthene µg/L <0.1 <0.1 <0.1 <0.1 <0.1 Polycyclic Aromatic Pyrene µg/L <0.1 <0.1 <0.1 <0.1 <0.1 Hydrocarbons Benzo(a)anthracene µg/L <0.1 <0.1 <0.1 <0.1 <0.1 Chrysene µg/L <0.1 <0.1 <0.1 <0.1 <0.1

Benzo(b+k)fluoranthene µg/L <0.1 <0.1 <0.1 <0.1 <0.1

Benzo(a)pyrene µg/L <0.1 <0.1 <0.1 <0.1 <0.1

Benzo(g,h,i)perylene µg/L <1 <1 <1 <1 <1 Dibenz(a,h)anthracene µg/L <5 <5 <5 <5 <5 Indeno(123-cd)pyrene µg/L <1 <1 <1 <1 <1 1,2-Dichlorobenzene µg/L <1 <1 <1 <1 <1 1,3-Dichlorobenzene µg/L <1 <1 <1 <1 <1 1,4-Dichlorobenzene µg/L <1 <1 <1 <1 <1 2-Chloronaphthalene µg/L <1 <1 <1 <1 <1 Hexachlorobenzene µg/L <1 <1 <1 <1 <1 Chlorinated Hexachloroethane µg/L <1 <1 <1 <1 <1 Compounds 1,2,4-Trichlorobenzene µg/L <1 <1 <1 <1 <1

4-Chlorophenylphenyl µg/L <1 <1 <1 <1 <1 ether* 4-Bromophenylphenyl µg/L <1 <1 <1 <1 <1 ether Di-n-butyl phthalate µg/L <10 <10 <10 <10 <10 Phthalates Butyl benzyl phthalate µg/L <10 <10 <10 <10 <10 Bis(2-ethylhexyl) µg/L <10 <10 <10 <10 <10 phthalate

135

Appendix 9: Phenolic compounds measured in the Kaalspruit water for the wet season sampling (September 2019).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Phenol µg/L <20 30 <20 49 50 2-Chlorophenol µg/L <1 <1 <1 <1 <1 2,4-Dichlorophenol µg/L <1 <1 <1 <1 <1 2,6-Dichlorophenol µg/L <1 <1 <1 <1 <1 2-Methylphenol (o-cresol) µg/L <1 <1 <1 <1 <1 3- and 4-Methylphenol µg/L 25 <1 <1 <160 <160 (m+p-cresol) 2,4-Dimethylphenol µg/L <1 <1 <1 <1 <1 2,4,5-Trichlorophenol µg/L <1 <1 <1 <1 <1 2,4,6-Trichlorophenol µg/L <1 <1 <1 <1 <1 4-Chloro-3-methylphenol µg/L <1 <1 <1 <1 <1 2,3,4,6-Tetrachlorophenol µg/L <1 <1 <1 <1 <1 Pentachlorophenol µg/L <1 <1 <1 <1 <1

Appendix 10: Phenolic compounds measured in the Kaalspruit water for the dry season sampling (June 2019).

Parameter Unit Site 1 Site 2 Site 3 Site 4 Site 5 Phenol µg/L 20 20 20 <20 <20 2-Chlorophenol µg/L <1 <1 <1 <1 <1 2,4-Dichlorophenol µg/L <1 <1 <1 <1 <1 2,6-Dichlorophenol µg/L <1 <1 <1 <1 <1 2-Methylphenol (o-cresol) µg/L <1 <1 <1 <1 <1 3- and 4-Methylphenol µg/L <1 <1 <1 <1 <1 (m+p-cresol) 2,4-Dimethylphenol µg/L <1 <1 <1 <1 <1 2,4,5-Trichlorophenol µg/L <1 <1 <1 <1 <1 2,4,6-Trichlorophenol µg/L <1 <1 <1 <1 <1 4-Chloro-3-methylphenol µg/L <1 <1 <1 <1 <1 2,3,4,6-Tetrachlorophenol µg/L <1 <1 <1 <1 <1 Pentachlorophenol µg/L <1 <1 <1 <1 <1

136