BINDURA UNIVERSITY OF SCIENCE EDUCATION

FACULTY OF SCIENCE EDUCATION

THE QUALITY OF WATER AT SELECTED POINTS ALONG

SAKUBVA RIVER IN MUTARE CITY.

Submitted By CHIGODORA PATIENCE (B1129584)

Supervisor: DR P MANYANGA

A DISSERTATION SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS OF THE BACHELOR OF SCIENCE EDUCATION HONOURS DEGREE IN BIOLOGICAL SCIENCES

2016

BINDURA UNIVERSITY OF SCIENCE EDUCATION

RELEASE FORM

NAME OF AUTHOR : CHIGODORA PATIENCE

PROJECT TITLE : THE QUALITY OF WATER AT SELECTED POINTS ALONG SAKUBVA RIVER IN MUTARE CITY

DEGREE TITLE : BACHELOR OF SCIENCE EDUCATION HONOURS DEGREE IN BIOLOGICAL SCIENCES.

YEAR TO BE GRANTED : 2016

SIGNED ______

PERMANENT ADDRESS : 723 CHIKANGA 1, MUTARE

CELL : 0774392646

Permission is hereby granted to the Bindura University of Science Education Library to produce single copies for scholarly or scientific research purposes only. The author does reserve other publication rights and the project or extensive extracts from it may not be printed or otherwise reproduced without the author’s written permission

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BINDURA UNIVERSITY OF SCIENCE EDUCATION

APPROVAL FORM

The undersigned certify that they have supervised, read and recommend to the Bindura

University of Science Education for acceptance a research project entitled: The quality of water at selected points along Sakubva River in Mutare city submitted by CHIGODORA

PATIENCE ,in partial fulfilment of the requirements for the bachelor of Science Education

Honours Degree in biological sciences programme.

…………………………………… ….…/…………/…………/

(Signature of Student) Date

…………………………………… ….…/…………/…………/

(Signature of Supervisor) Date

…………………………………… ….…/…………/…………/

(Signature of Chairperson) Date

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DECLARATION

I, CHIGODORA PATIENCE, declare the research project herein is my own work and has not been copied or lifted from any source without the acknowledgement of the source.

…………………………………… ….…/…………/…………/

Signed Date

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DEDICATION

This research is dedicated to my late father Mr. J Chigodora who accorded me an opportunity to education and the whole lot of my upbringing.

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ACKNOWLEDGEMENT

Special thanks to my supervisor Dr Manyanga for all the support, guidance and encouragement and most of all patience. I thank the management of Mutare City Council especially Mr Panishi and Mr Machaka who granted me permission to carry out tests on water quality from Sakubva River. I would like to thank students of the University of Zimbabwe who helped me to carry out tests on water quality along Sakubva River at different sites. Finally I wish to thank my husband Farai, son Tinenyasha, my mother Rachel, mother in-law Rinnet and friends for their committed support and appreciation.

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ABSTRACT

The aim of the research was to assess the quality of water along Sakubva River downstream Mutare city through the analysis of conductivity, dissolved oxygen content, temperature and pH values as well as to identify the source(s) of any pollution from the water at three different sites. Station one was before the industrial effluent discharge point into the river, station two was located downstream after the industrial effluent discharge and station three was also located downstream after sewage effluent discharge. Tests were done at the three sites from December 2015 to April 2016 over a period of ten fortnights. Two- way ANOVA was used test for significant difference in each of the measured water characteristics among the stations and among the months. Fishers’ pairwise comparison post hoc test was used to identify the sites or months that differed for any that showed significant difference. Results showed that there was no significant difference among the three stations in terms of conductivity, nitrate levels, temperature and turbidity but there was significant difference among the three stations in terms of pH levels and among the months for dissolved oxygen conten The results showed that the quality of water in Sakubva River is altered as the river flows downstream in terms of pH values due to the introduction of contaminants from both point source (industrial and sewage water) and non-point source (erosion and agricultural leaching).since station two and station three showed significant difference in terms of water pH and station two is located just after industrial effluent discharge and station three after sewage works discharge. However, there is need to implement common objectives, compatible policies and programmes for improvement in the sewage and industrial waste water treatment methods

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TABLE OF CONTENTS

RELEASE FORM ...... i

APPROVAL FORM ...... ii

DECLARATION ...... iii

ACKNOWLEDGEMENT ...... v

ABSTRACT ...... vi

LIST OF TABLES ...... x

LIST OF FIGURES ...... xi

LIST OF APPENDICES ...... xii

CHAPTER 1 : INTRODUCTION ...... 1

1.1 Background to the study ...... 1

1.2 Statement of the problem ...... 2

1.3 Aim of research ...... 3

1.4 Objectives ...... 3

1.5 Research questions ...... 3

1.6 Hypothesis ...... 3

1.7 Justification ...... 4

CHAPTER 2 : LITERATURE REVIEW ...... 5

2.1 Introduction ...... 5

2.2 Categories of water use...... 5

2.2.1 Human consumption ...... 5

2.2.2 Industrial use ...... 6

2.2.3 Environmental water quality ...... 6

2.3 Water quality tests ...... 7

2.3.1 Chemical indicators ...... 7

2.3.2 Physical indicators...... 8

2.3.3 Biological indicators ...... 9

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2.4 Water pollution ...... 9

2.4.1 Causes of water pollution ...... 9

2.5 Sources of river pollution in Mutare city ...... 10

2.6 Role of EMA in water quality ...... 11

CHAPTER 3 : MATERIAL AND METHODS ...... 12

3.1 The study area ...... 12

3.2 The research design ...... 12

3.3 Data collection ...... 13

3.4 Data analysis ...... 13

CHAPTER 4 : RESULTS ...... 14

4.1 Results of parameters measured ...... 14

4.2 Dissolved oxygen (DO) ...... 14

4.3 Nitrate ...... 15

4.4 Temperature ...... 16

4.5 Potential hydrogen (pH) ...... 17

4.6 Conductivity ...... 18

4.7 Turbidity ...... 19

CHAPTER 5 : DISCUSSION, CONCLUSION AND RECOMMENDATION...... 21

5.1 Discussion ...... 21

5.1.1 Dissolved Oxygen ...... 21

5.1.2 Nitrates ...... 21

5.1.3 Temperature ...... 21

5.1.4 pH of the water ...... 21

5.1.5 Conductivity ...... 22

5.1.6 Turbidity ...... 22

5.2 Conclusion ...... 22

5.3 Recommendation ...... 23

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REFERENCES ...... 24

APPENDICES ...... 26

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LIST OF TABLES

Table 2-1: Six chemical and physical limits for drinking water supplies by EMA...... 5 Table 2-3: Permissible limits for municipality and industrial effluent by EMA...... 6 Table 4-1: Grouping Information Using the Fishers pairwise Method and 95% Confidence 15 Table 4-2: Grouping Information Using Fisher LSD Method and 95% Confidence ...... 18

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LIST OF FIGURES

Figure 3.1 : Map of Sakubva River and the three sampling points ...... 12

Figure 4. 1: Means of dissolved 0xygen at the 3 stations from December 2015 to April 2016...... 14 Figure 4. 2 : Means of nitrate levels at the 3 stations from December 2015 to April 2016 .... 15 Figure 4. 3: Means of temperature at the 3 stations from December 2015 to April 2016 ..... 16 Figure 4.4: Means of potential hydrogen at the 3 stations from December 2015 to April 2016 ...... 18 Figure 4.5 : Means of conductivity at the 3 stations from December 2015 to April 2016 ..... 19 Figure 4. 6 : Means of turbidity at the 3 stations from December 2015 to April 2016 ...... 20

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LIST OF APPENDICES

Appendix 1: means from the three stations from December 2015 to April 2016 ...... 26 Appendix 2: Acceptance letter to carry out water quality tests in Sakubva River ...... 27 Appendix 3 Station 1 site located in greenside suburbs ...... 28 Appendix 4 Station two site located in Sakubva residential area...... 29 Appendix 5 Station three site located after Gimboki sewage works ...... 30

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CHAPTER 1

INTRODUCTION

1.1 Background to the study Water has a number of roles in living organisms such as a living environment, metabolite; solvent and temperature buffer. Many organisms such as fish live in water and cannot survive out of it. Water is a metabolite in many reactions, either as a reactant or as a product of reaction, for example, in photosynthesis, digestion and aerobic respiration. A wide range of compounds such as sugars, amino acids,some proteins, etc. dissolve in water and water helps to buffer temperature changes because of its relatively high specific heat capacity.

The quality and safety of water is of great concern because of interest in health and environmental quality. Water pollution is a major problem in the global context. A geological survey conducted in the USA in 2009 showed that one of every ten private well in the country contained one or more contaminants at concentrations exceeding the US environmental protection agency’s human health benchmarks and a third of river shad at least a problem (Desimone et al, 2009). Water can be obtained from ground or surface water bodies including aquifers, dams, lakes and rivers and then be treated so that it can be used for human consumption, domestic and industrial use. It may also be obtained from sewage treatment plant discharge. River water is used for irrigation purposes and also in rehabilitation of natural ecosystems (WHO, 2006).

. River water in most urban centres is affected in three ways namely sewage, industrial and institutional waste (Mukokeri, 1999). Household detergents which are fed into sewages during discharge contain nitrates and phosphates which lead to eutrophication of river systems and may accelerate plant growth rates at the expense of aquatic creatures. These plants upset the ecological balance of some rivers depriving other aquatic organisms of oxygen which may eventually die (Moyo, 1997). Metals such as zinc, lead, arsenic and mercury originating from industries also find their way into rivers thereby endangering aquatic life. Oil spills which drain into natural waters together with wastes derived from hospitals and clinics pose a threat to rivers and streams which pass through urban centres (Miller, 1994). Singh and Kai (2003) studied the impact of industrial effluents and domestic

1 sewage on river Ganga at Allahabain India and reported that all the pollution parameters were beyond the permissible limits and unfit for aquatic life and human consumption. In some urban centres such as Harare, Chitungwiza and Mutare, water borne diseases like cholera, typhoid and dysentery have been reported (Chenje and Johnson, 1994). Developing countries like Zimbabwe are facing challenges in attending to sewage treatment plants due to shortage of some spare parts and funds which are required to fix them. Waste disposal and management are challenges which urban centres confront due to poverty and municipal budgets which are under strain (Miller, 1994, Jordan, 1984).This may result in the municipalities failing to cope with ever increasing demand for sewage and general waste disposal and management needs (WCED,1991). In other areas, rivers which pass through urban centres have been turned into sewers as they drain waste water generated in towns and cities (Mapira and Mugwini 2005). These conditions are a threat to human health and aquatic life (Katyal and Satake, 2001).There is new focus on water quality and this research intends to add to the knowledge in this area through testing the water along Sakubva River in Mutare City. Therefore the research intends to find out the quality of water along Sakubva River.

1.2 Statement of the problem Mutare is a fast growing urban centre whose municipality, like most municipalities in the country, is facing some challenges meeting the sewage treatment needs due to ever increasing demand as a result of city expansion (Mukokeri, 1994). Most of the suburbs in Mutare are located along Sakubva River, which passes through some villages before draining into Odzi River. About 30-000 people in downstream communities such as Dora rely on the Sakubva River water for irrigation and domestic purposes. Gimboki sewage treatment plant discharges its water into the Sakubva River. The sewage treatment works was designed for 33,6 mega litres per day but a visit in April 2014 revealed that it was handling 44 mega litres per day and the sedimentation tanks no longer function effectively. This is way above its carrying capacity. It is believed that sewage effluent and industrial effluent are discharged into Sakubva River partially treated due to city expansion and financial constraints. It is therefore important carry out water quality tests on the various points along the river and detects presence and potential sources on any pollutants in the water.

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1.3 Aim of research To assess the quality of water in Sakubva River through analysis of potential hydrogen, temperature, turbidity, dissolved oxygen, conductivity, nitrite and nitrate levels as well as to identify the source(s) of any pollution from the water.

1.4 Objectives

1. To determine the quality of water in Sakubva River in terms of temperature, potential hydrogen, dissolved oxygen, turbidity, conductivity, ammonia, nitrate and nitrite levels at point before and after discharge from industries and Gimboki sewage treatment plant. 2. To compare the temperature, pH, dissolved oxygen, turbidity, conductivity, ammonia, nitrates and nitrite levels before and after discharge of Mutare city Central Business District (CBD), industries and the Gimboki sewage plant. 3. To establish if the quality of water in Sakubva River meet the expected standards on industrial and sewage effluent discharge by EMA.

1.5 Research questions

1. What is the quality of water in Sakubva River before it enters Mutare city, after the CBD industries and after point of discharge from the Gimboki sewage treatment plant? 2. . Does the quality of water in Sakubva River change significantly in terms among the selected points and over the period December to April? 3. Does the quality of water in Sakubva River meet the expected standards on industrial and sewage effluent disposal by EMA?

1.6 Hypothesis H0: The quality of water in Sakubva River has the same potential hydrogen, temperature, dissolved oxygen, conductivity, nitrates and nitrite levels before and after the discharge from Mutare city, industries and the Gimboki sewage plant. H1: The CBD, Industrial and Sewage Treatment activities in Mutare City affect the quality of water in Sakubva River significantly in terms of potential hydrogen, temperature, dissolved oxygen, conductivity, nitrates and nitrite levels.

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1.7 Justification The research will establish the quality of water in Sakubva River in terms of the levels of minerals present. It will also establish any major source of pollutants in the river. This will help to develop scientifically based policy and technical guidelines on enabling national, regional and local authorities to improve their regulatory frame works and to enhance the management of their water resources and aquatic ecosystem. Results of this research are going to be beneficial to downstream community by having knowledge on wise use of water since it is imperative for sustainable development. However decision makers are going to benefit as well by being informed on the quality of water so that they can priotise and works towards sustainable water secure globe. This can encourage local authorities work towards the use of other methods of sewage treatment like the use of lagoons that provides settlement and further biological improvements. These lagoons are highly aerobic and colonization by native macrophytes like reeds is often encouraged. Small filter feeders assist in treatment by removing fine particulates.

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CHAPTER 2 : LITERATURE REVIEW 2.1 Introduction Water quality refers to the chemical, physical and biological and radiological characteristics of water. It can also be defined as a measure of the condition of water relative to the requirements of one or more biotic species and to any human need or purpose (Desimone et al, 2009).It is frequently used by reference to set standards against which compliance can be assessed. The common standards which are used to assess the water quality relate to drinking water, health of ecosystems and safety of human contact (Skipton et al, 2005). The parameters of water quality are determined by the intended use.

2.2 Categories of water use 2.2.1 Human consumption Untreated water may have contaminants such as viruses, inorganic contaminants such as salt, bacteria and protozoa. It may also contain chemical contaminants from industrial processes, petroleum use, pesticides, herbicides and radioactive contaminants (Frankenberger and Janssen, 1990). The water for human consumption should be treated so as to destroy microbes and to make it free and safe from pathogens. The table below shows the chemical and physical limits for drinking water supplies.

Table 2-1: Six chemical and physical limits for drinking water supplies by EMA.

Group Number substance Unit Mg/L Lower limit Upper limit Toxic Lead (Pb) Mg/L - 0,1 Toxic Arsenic (As) Mg/L - 0,05 Toxic Selenium (Se) Mg/L - 0,05 Toxic Chromium (6+) Mg/L - 0,05 (Cr) Toxic Cyanide (CN) Mg/L 0,20 Toxic Cadrium (Cd) Mg/L - 0,05 Toxic Barium (Ba) Mg/L - 1,0 Toxic Mercury (Hg) Mg/L - 0,001 Toxic Silver (Ag) Mg/L - n.m Affecting Fluoride (F) Mg/L 1,5 4,0 The Environmental Management (water quality standards) Regulations 2007.

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2.2.2 Industrial use Most dissolved minerals contain ions which may affect suitability of water for a range of industrial and domestic purposes. Dissolved minerals may affect suitability of water for a range of industrial and domestic purposes. The presence of ions such as calcium and magnesium may interfere with the cleaning action of soap and can form hard sulphate and soft carbonate deposits in water heaters. However, the hard water may be softened to remove these ions (Katyal and Satake, 2001). Table 2-2 below show the permissible limits for municipal and industrial effluents so as to maintain the quality of water in aquatic ecosystems.

Table 2-3: Permissible limits for municipality and industrial effluent by EMA.

Parameter Limit Test method BODS at 20 0C 30mg/L T25 861(Part 3):2006-Five-day BOD Method COD 60mg/L T25 861 (Part 4): 2006-Dichromate Digestion model Colour 300 TCU 180 7887: 1994, water quality-Examination and determination of colour Section 3: Determination of true colour using optical instruments pH range 6,5-8,5 T25 861 (part 2):2006-Electrometric method Temperature 20-35 0C range Total 100mg/L T25 861 (Part 1):2006-gravimetric Method Suspended solids Turbidity 300 NTU APHA Standard Methods: 2130B. Nephelometric Method Source : EMA water quality standards. Regulations (2007). 2.2.3 Environmental water quality Environmental water quality is relative to the water bodies such as oceans, rivers and lakes. Water quality standards for surface waters vary significantly as a result of different environmental conditions, ecosystems and intended human uses. High populations of certain microbes as well as toxic substances can present a health hazard for non-drinking purposes such as irrigation, fishing, boating, swimming and irrigation. These conditions may also affect wildlife which uses the water for drinking or as a habitat (Mapira and Mugwini, 2005). The modern water quality laws specify generally the protection of fisheries and recreational use. However, there is some desire among the public to return water bodies to pristine or pre- industrial conditions. Given the landscape changes such as land development and urbanisation in the watersheds of many freshwater bodies would be a significant challenge if returning to pristine conditions. Environmental scientists are now focusing on achieving goals for maintaining a healthy ecosystem in these cases as well as concentrating on

6 protection of populations of endangered species and protecting human health (Katyal and Satake, 2001). The water pollution principal from urban areas include treated effluents discharged from sewage treatment plants and untreated effluents that by pass sewage treatment plants (Mapira, 2007)

2.3 Water quality tests Water quality tests include physical, chemical and biological testing. Most measurements on water quality are commonly made on site and in direct conduct with the water source which include temperature, PH, dissolved oxygen and conductivity. Biological testing involves the use of plant, animal and microbial indicators to monitor the health of an aquatic ecosystem (Burton and Pitt, 2001). In urban areas, most municipal water systems use water purification technology in order to remove contaminants from the water source water before it is distributed to businesses and other recipients. In Sakubva River, water quality tests are done at Yeovil and Gimboki sewage treatment plants.

2.3.1 Chemical indicators 2.3.1.1 Dissolved oxygen (DO ) Dissolved oxygen referred to the oxygen in the water body which is necessary for many aquatic species to survive. Dissolved oxygen test is used to measure water's ability to support plants and animals. There are many different factors that affect the amount of dissolved oxygen in water, the main one being temperature. As temperature rises, less gas will dissolve. Dissolved oxygen is measured in Sakubva River because oxygen is necessary for many aquatic species to survive. Lots of organic debris from fallen leaves, sewage leaks can cause a decrease in dissolved oxygen concentration (Mapira, 1997). 2.3.1.2 pH level The pH is a measure of acidity and ranges from 0 (extremely acidic) to 14 (extremely basic) with 7 being neutral. The PH of most water is in the range of 6,5 to 8,5. If the water becomes too acidic or too basic, it will kill aquatic organisms. (Skipton et al, 2005). 2.3.1.3 Nitrates Nitrogen is necessary for plant and animal life. Water in Sakubva River is tested for nitrates to monitor and control eutrophication which causes more plant.

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2.3.1.4 Biochemical oxygen demand (BOD ). BOD is a measure of oxygen removed from an aquatic environment by aerobic micro- organisms. It measures the amount of organic pollution in lakes and streams. 2.3.1.5 Chemical oxygen demand (COD ). COD is the standard method for indirect measurement of the amount of pollution in a sample of water. COD measures the oxygen demand of oxidisable pollutants. Results of COD indicate the amount of water dissolved oxygen consumed by contaminants during two hours of decomposition for a solution of potassium dichromate (Trivedi and Goel, 1986). 2.3.1.6 Heavy metals Heavy metal salts in solution causes a serious form of pollution and is very harmful to aquatic organisms at very low concentration (Schmitz, 1996). Metals such as zinc, lead, arsenic and mercury are the ones which originate from industries and are harmful to both human and aquatic life. 2.3.1.7 Phosphorous (Orthophosphates ) Phosphates are a nutrient needed in growth. The phosphate ion is found in shells, bones and in animal teeth. By removing phosphorous from sewage the amount of phosphate ions in the water will be lowered (Mapira and Mugwini, 2005). 2.3.1.8 Pesticides Run off pesticides leads to contamination of surface water and biota as well as dysfunction of ecological system surface waters.

2.3.2 Physical indicators 2.3.2.1 Transparency (turbidity ) These are measures of water clarity, which allows sunlight to penetrate to a greater depth. The main sources of turbidity are erosion, living organisms, and those from human endeavours 2.3.2.2 Total solids Measures both dissolved and suspended solids. There are six major types of total solids; silt, clay, soil runoff, plankton, industrial waste, and sewage. Total suspended solids (TSS) highly depend on the speed of the water flow. 2.3.2.3 Water temperature Temperature is a very important part of a river's ecology. There are many natural and human factors that can affect a river's temperature. Human factors include industry, development,

8 and dams. To measure temperature and flow rate you must find two places along the river that are about 1.6 kilometres apart that have the same conditions, then two people measure the temperature at approximately the same time. If the difference is greater than 2 degrees Celsius, then there is thermal pollution. 2.3.2.4 Specifics conductance or Electrical conductance, Conductivity Specific conductance is a measure of the ability of water to conduct an electrical current. It is highly dependent on the amount of dissolved solids such as salt in the water. It is an important water quality measurement because it gives a good idea of the amount of dissolved material in the water. High specific conductance indicates high dissolved solids concentration (Miller, 1994). 2.3.3 Biological indicators 2.3.3.1 Coliform bacteria (Escherichia coli or E coli) This is a bacterium that propagates in the digestive tracts of humans and animals. They coexist with other bacteria so they used as indicators of possible pathogenic contamination. There are many ways faecal coliform can enter a waterway such as animal waste, untreated sewage, combined sewage overflow, and septic tanks. Other micro-organisms such as Burkholderia pseudomallei, Cryptosporidium parvum , Norovirus and other viruses are used as biological indicators to monitor the water quality (Thomas and Mullar, 1987). 2.4 Water pollution Water pollution is the contamination of water bodies. Water pollution affects the entire biosphere that is plants and organisms living in these bodies of water (Laws, 2000). 2.4.1 Causes of water pollution 2.4.1.1 Domestic sewage It is a sewage which contains impurities such as organic materials and it originate primarily from the laundry, bathroom and kitchen sources. The sewage is likely to contain disease causing microbes since it contains a wide variety of dissolved and suspended solids. Most detergents and washing powders which are used to clean houses contain harmful chemicals which affect the health of all forms of life in the water (Skipton et al, 2005). However, domestic water is the source of pathogens and putrescible organic substances because pathogens are excreted in faeces hence all sewage from cities and towns is likely to contain pathogens of some type, potentially presenting a direct threat to public health (Tagwira, 1998). The nitrates, phosphates and organic matter found in human waste serve as a food for

9 algae and bacteria and this will cause these organisms to overpopulate and they will use the dissolved oxygen that is naturally found in water thereby making it difficult for other organisms in the aquatic environment to live (Frankenberger and Janssen, 1990). 2.4.1.2 Industrial wastes Water bodies get polluted due to the discharge of effluents from industries. Metals originating from industries endanger aquatic life (Miller, 1994).Oil spills which drain into natural waters are hazardous to natural ecosystems. 2.4.1.3 Stream bank cultivation Stream bank cultivation releases fertilisers such as phosphates and nitrates which seep into the soil and eventually drain into the river. Nitrates and phosphates upset ecological balance at the expense of other aquatic creatures (Moyo, 1997). 2.4.1.4 Municipal sewage treatment plants Treated effluents discharged from sewage treatment plants and untreated effluents which by pass sewage treatment plants are also water pollution sources from urban areas (Moyo, 1997).In some cases water discharged from the Gimboki sewage plant may be partially treated especially when the plant is overloaded. . 2.4.1.5 What is the solution ? Pollution can be overcome by dilution that is sewage must not be discharged directly into a nearby body of water but it should pass through a combination of physical, biological and chemical processes that remove some most of pollutants and this is done in sewage treatment plants (Moyo, 1997). Decisions should be made on the type and degree of treatment and control of wastes. 2.5 Sources of river pollution in Mutare city The problem of river pollution in the city of Mutare was first exposed in 1998 following an outcry from the public (Mukokeri, 1999). Wastewater is released directly into streams which eventually empty their cargo into Sakubva River. The industries do not have treatment processes for example, Workshops and Garages such as the Zimbabwe United Passenger Company (ZUPCO), Zimbabwe National Army behind Megawatt house, Quest motors (a car assembly), Amtec and Green Market dump used oils, greases, fuels, scrap metals, tires and other forms of refuse (Mukokeri, 1999). Pungwe Breweries produces opaque beer, release acidic and low pH effluent and solids into the river, while Dairiboard discharges milk washes into the river (Mukokeri, 1999).Mutare Board and Paper mills produces and dumps huge paper and chemical effluent into Sakubva

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River leading to an increase in pH levels and a decline in dissolved oxygen (DO %) levels. The amount of dissolved solids is also high making the survival of aquatic life very difficult (Mukokeri, 1999). Zimbabwe Allied Timbers (Forestry Commission), Border Timbers and PG Zimboard release glue, oil, saw dust, pulp and timber chips into the river (Mukokeri, 1999). Stream bank cultivation is rampant in the city thereby releases fertilisers into the river. 2.6 Role of EMA in water quality The Environmental Management Agency (EMA) maintains an extensive surface water quality monitoring network along major and minor water bodies across the country, which includes streams (rivers), dams and lakes. These are monitored on a monthly basis under a monitoring programme which involves the collection of water samples, on site water quality tests and laboratory analytical tests. An ambient monitoring exercise measures concentrations of various chemical water quality parameters which include biological oxygen demand (BOD),chemical oxygen demand (COD), dissolved oxygen (DO), pH, nitrates and phosphates. These parameters provide essential information on the state of a water body (WHO, 2006).

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CHAPTER 3 : MATERIAL AND METHODS

3.1 The study area The study was conducted on Sakubva River in Mutare, Zimbabwe. The river runs from Greenside suburbs of Mutare city past the Central Business District area, then the Paulington industrial area, Yeovil, Sakubva, Natview, Hob-house, and Dangamvura high density suburbs and finally past Gimboki Sewage Works effluent discharge point. River water from Sakubva River is used for urban farming by Sakubva, Natview, Hob-house, and Dangamvura residents. Downstream Dora residents also use it to irrigate their vegetable gardens, washing, bathing, and as a source of drinking water for their domestic animals such as the cattle and goats.

Figure 3.1: Map of Sakubva River and the three sampling points

3.2 The research design Row data was collected from three sampling stations located along the Sakubva River for the period from December 2015 to April 2016. Station one was located at Max Bridge in Greenside suburb. This area was the furthest upstream the river, before the river flows through the city. It is expected to be uninfluenced by pollutions caused by the city’s activities and was chosen as the control point on the assumption that it was relatively unpolluted. Station two was based at Chikanga Bridge which is located in Sakubva residential suburb.

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This point is located below the industrial effluent discharge points from most industries. It is found immediately after industrial effluent discharge but before the Gimboki sewage treatment plant. Station three was at the point just after the Gimboki sewage treatment plant discharges into Sakubva River. At each station, three different points were tested for temperature, dissolved oxygen content, potential hydrogen and conductivityacross the river. Measurements were taken just below the water surface. The means of the three measurements of each parameter per station were used in the final analyses. The measurements were taken twice every month, every second Sunday, between 11am and 12pm over a period of five months from December 2015 to April 2016.

3.3 Data collection Water was tested using probes at each of the three stations which were selected along Sakubva River. Data collection was done with the help of University students who were on attachment, at Mutare City Council. Manta2 profiling system and specific probes were used to measure potential hydrogen (pH), dissolved oxygen (DO), temperature and conductivity on site along Sakubva River. A WQ211 pH sensor was used to measure pH, a WQ401 Dissolved Oxygen sensor used to measure dissolved oxygen, a WQ-COND conductivity sensor used to measure conductivity and a WQ101 temperature sensor used to measure temperature. Turbidity and nitrates were determined with the assistance of EMA who did the tests in their laboratories.

3.4 Data analysis Data analyses were done using the MiniTab 17 software. The means of all the measured parameters from the three points at each site for each data collection day were calculated and used in the analyses. Two- way ANOVA was used to test for significant difference in each of the measured parameters among the sites and among the months for each site. . For any that showed significant difference a Fisher’s pairwise comparison post hoc test was done to identify the sites or months that differed.

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CHAPTER 4 : RESULTS

4.1 Results of parameters measured Appendix 1 shows the raw data of the parameters measured at the 3 sites over a period of 5 months. The results showed that there was significant difference among the months in terms of dissolved oxygen content as well as among the stations in terms of pH values. However there were no significant differences in terms of nitrates levels, temperature, conductivity and turbidity among stations and months.

4.2 Dissolved oxygen (DO)

Figure 4. 1: Means of dissolved 0xygen at the 3 stations from December 2015 to April 2016. There is a general increase in concentration of DO from December 2015 mean to April 2016 on all the stations. Analysis of Variance shows that there was no significant difference among the three stations in terms of DO (F= 0.77, P < 0. 473). However, there was significant increase in DO among the months from December to April 2016 (F-Value =16.74, P-Value =0,001). Fisher’s pairwise comparison post hoc test showed that the month of April is

14 significantly higher DO concentration compared January, February, March and December which did not differ among themselves. Table 4-1: Grouping Information Using the Fishers pairwise Method and 95% Confidence month N Mean Grouping 5 6 7, 14500 A 4 6 5, 99667 B 1 6 5, 41667 B 3 6 5,33667 B 2 6 5, 31667 B Means that do not share a letter are significantly different.

4.3 Nitrate

2.25 Station 1 2 2.00 3

1.75

1.50

1.25

Mean of Nitrates of Mean 1.00

0.75

0.50

Dec Jan Feb March April Month

Figure 4. 2: Means of nitrate levels at the 3 stations from December 2015 to April 2016

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4.4 There was an increase in nitrate levels at station one from December 2015 to January 2016. Nitrate levels were almost constant from January to March 2016 and there is a decrease in the month of April. There was a sharp increase on nitrate levels mean in December 2015 at station two and a decrease in January mean. The means at station two becomes constant from February to April 2016. At station three there was an increase in nitrate levels mean from January to February 2016 and a sharp decrease from February to April. Analysis of variance shows that there was no significant difference among the three stations in terms of nitrate levels (F-value= 1.44, P-value= 0, 76) and there was no significant difference in nitrate levels among the months from December 2015 to April 2016 (F-value =0.258, P-value= 0,560).Temperature

23.0 Station 1 2 3

22.5

22.0 Mean of Temperature of Mean

21.5

Dec Jan Feb March April Month

Figure 4. 3: Means of temperature at the 3 stations from December 2015 to April 2016

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There was a decrease on temperature levels from December 2015 mean to January 2016 at all the three stations. There was a sharp increase in temperature from February to March at stations two and three and a decrease in the month of April at both stations. At station one there was a decrease in temperature from January to March 2016 and a sharp increase in the month of April. Analysis of variance shows that there was no significant difference among the three sites in terms of temperature levels (F-value= 0.14, P-value= `0.91) and was no significant difference in temperature levels among the months from December 2015 to April 2016 (F-value= 0.867, P-value= 0.474).

4.5 Potential hydrogen (pH) There was an increase on pH values from December 2015 mean to February 2016 at station two and a decrease from February to April at the same station (Figure 4.4). There was a sharp increase in potential hydrogen levels from December 2015 to April 2016 at station three. There was an increase from January to March 2016 at station one and a decrease in April in terms of pH levels. Analysis of variance shows that there was no significant difference among the three sites in terms of pH values (F-value=3.83, P-value= 1.72) but there was significant difference among the months in terms of pH values (F-value=0.037, P-value= 0.180).Fisher’s pairwise comparison post hoc test showed that station 2 and station 3 were significantly different in terms of water pH.

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8.5 Station 1 2 3 8.0

7.5

7.0 Mean of pH Mean

6.5

6.0

Dec Jan Feb March April Month

Figure 4.4: Means of potential hydrogen at the 3 stations from December 2015 to April 2016

Fisher Pairwise Comparisons: Response = pH, Term = Station

: Table 4-2: Grouping Information Using Fisher LSD Method and 95% Confidence

Station N Mean Grouping 3 10 7.495 A 1 10 7.157 A B 2 10 6.701 B Means that do not share a letter are significantly different.

4.6 Conductivity There was a decrease in conductivity from December to January at all the three stations and a sharp increase from January to February at stations two and three. There was a decrease in conductivity from December 2015 to March 2016 at station one and a decrease in the month of April. There was a decrease in conductivity at stations two and three from March to April 2016. Analysis of variance shows that there was no significant difference among the three sites in terms of conductivity (F-value= 0.79, P-value= 2,18) but there was no significant

18 difference in conductivity from December 2015 to April 2016 (F-value= 0.464, P-value= 0.103).

410 Station 1 400 2 3 390

380

370

360

350 Mean of Conductivity Mean 340

330

320 Dec Jan Feb March April Month

Figure 4.5: Means of conductivity at the 3 stations from December 2015 to April 2016

4.7 Turbidity Generally from the graph below, there was an increase in turbidity means from December 2015 to March 2016 at station three and a decrease in April at the same month. There was an increase in turbidity in the months of December, January and March at station two and a decrease in turbidity in the months of February and April 2016 at the same station. At station one there was only an increase in turbidity in the month of February and a decrease in the other months. Analysis of variance shows that there was no significant difference among the sites in terms of turbidity values (F-value= 1.59, P-value= 0.95) and no significant difference

19 among the months in terms of turbidity values (F-value=0.226, P-value= 0.453).

7.5 Station 1 2 7.0 3

6.5

6.0

5.5 Mean of Turbidity Mean

5.0

4.5

Dec Jan Feb March April Month

Figure 4. 6: Means of turbidity at the 3 stations from December 2015 to April 2016 .

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CHAPTER 5 : DISCUSSION, CONCLUSION AND RECOMMENDATION.

5.1 Discussion 5.1.1 Dissolved Oxygen Results showed that there was no significance difference among sites in terms of dissolved oxygen content but there was significant difference among months. This could be as a result of low temperature caused by high exposure to sunlight which will cause less gas to dissolve in water as well as industrial discharge from industries which will cause a reduction in oxygen levels. Low DO indicates polluted water and the values have been widely adopted as a measure of pollution effect (RAO, 2005). The highest value of DO obtained is around 7.4 which fall under the EMA standards of waste water disposal. Most healthy water bodies have high levels of DO (Mapira, 1997). 5.1.2 Nitrates Nitrates levels obtained from Sakubva River revealed no significant difference among the sites and months maybe because sewage and effluent discharge was monitored by regulating authorities such as EMA. Nitrate mean levels obtained ranges between 5 and 7, 4 and they meet the standards of industrial and sewage effluent discharge by EMA. Nitrate content which is more than 100mg/L impact bitter taste to water and may cause physiological problems (Miller, 1994). Nitrate causes the overgrowth of algal, other organisms thereby impacting an unpleasant taste and odour to the water thus hindering the quality of water (Marshal, 1997). 5.1.3 Temperature The mean temperature was ranging between 21, 1 and 22, 7 (fig 4) among the sites were consistent with permissible limits set for industrial and sewage effluent disposal by EMA (EMA regulations standards statutory, 2000). The highest mean temperature was 22, 6 for the water in Sakubva River. When temperature goes up, water will hold more dissolved solids like salt and sugar but fewer dissolved gases like oxygen (Moyo, 1997). Results of this study revealed that there were no significant differences among the sites and months may be due to the same climatic conditions in the region and values exposed meet the regulations set by EMA. 5.1.4 pH of the water This study has shown that there was significant difference among the stations in terms of pH values from December 2015 to April 2016 may be due to industrial effluents discharge at

21 station two because industries can release glue, oil and can release and dump low pH effluent into the river. At station three, sewage effluents discharge contain nitrates and phosphates which will cause variation in pH values due to the presence of ion concentration thereby reducing the quality of water in Sakubva River to some extent. The mean pH values are typical of tropical rivers (Moyo, 1997). The highest mean pH value is 8,3 in the month of April at station two (fig 5).Most aquatic organisms are affected by pH because most metabolic activities are pH dependant (Wang et al, 2002). The pH outside range of 6, 5 to 8,5 reduces the diversity in the river because it stresses the physiological systems of many organisms and can reduce water quality (KWW, 2001). Values obtained at station two do not meet the expected standard by EMA except for station three and one maybe the station was affected by industrial activities at the area which may have contributed to rise in pH levels. . 5.1.5 Conductivity The results showed that there was no significant difference in terms of conductivity among sites and months may be it was attributed by exothermic reactions which were taking place in the water body between the ionic species (Miller, 1994). The highest mean conductivity recorded was 400 and is highest as compared to the expected standards for sewage and environmental effluent discharge standards. High conductivity is caused by warm temperatures. 5.1.6 Turbidity The results revealed that there was no significant difference among the sites and months from December 2015 to April 2016 maybe because it was the rainy season and most substances can be washed away by water. However excess soil erosion, dissolved solids or excess growth of microbes can cause turbidity and all of these can block light (Mapira, 1997). At station three may be micro-organisms which will be in water and in sewage effluent discharge will cause turbidity of water. At station two maybe industrial effluents cause water to be turbid and at station once since it was the rainy season, maybe mud causes water to be turbid.

5.2 Conclusion The quality of water in Sakubva River, in Mutare district, Manicaland province of Zimbabwe is generally good with little pollution. Variation in pH value among sites indicate that there is high risk of water contamination from industrial and sewage monitoring parameters on a

22 large scale. It was seen that from all the parameters studied; only potential hydrogen and dissolved oxygen content revealed significant difference either among sites or months as compared to the parameters which were tested. It is actually possible to maintain Sakubva River in good condition by regulating effluent discharge from industries and sewage works so as to reduce the risk of pollution as in station two and three.

5.3 Recommendation Strict measures should be exercised by the local authority to ensure that industrial effluent discharged into rivers is pre-treated. There is need to refurbish the existing sewage treatment plants so as to accommodate the ever increasing Mutare city population. Continuous assessment of water quality should be done in aquatic ecosystems and laws should be implemented.

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Burton, G., A. and Pitt, R. (2001).Storm water effects, handbook: A tool box for water shed managers, scientists and engineers. Lewis publisher, New York.

Chenje, M. And Johnson, P. (1994). State of the environment in Southern Africa. IUCN, Harare.

Desimone, L. A, Hamilton, P. A. and Galliam, R. J. (2009). Quality of water from domestic wells in principle aquafires of the United States. NAWQA scientific investigation report 2008-5222 htlp// water usgs. Gov/ nawqa/.

Frankenberger, J. and Janssen, C. (1990). Why and how to test home water supplies. Purdue extension.

Goel, P., K. (2006). Water pollution, causes, effects and control. New Age international, New Delhi.

Jordan, J., D. (1984). Local government in Zimbabwe. Mambo Press, Gweru.

Katyal, T. And Satake, M. (2001). Environmental pollution. New Dehli. Anmol publications pvt Ltd.

Kentaucky Water Watch (KWW). (2001). Dissolved oxygen and water quality. Stately, US.

Laws, E., A. (2000). Aquatic pollution: An introductory text. John Wiley and sons, NewYork.

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Mapira, J. (2007). Pollution of the Sakubva River in the city of Mutare (Zimbabwe) culprits, penalties and consequences, Zimbabwe journal of geographical research. Vol. 1. NO// 2:87.97.

Mapira, J. and Mugwini, P. (2005). River pollution in the city of Masvingo. A complex issue. Zambezia Vol 32. No’s i / ii: 95-106.

Miller, T. (1994). Living in the environment: Principles, Connections and Solutions. Wardsworth Publishing Company.

Moyo, N. (1997). (ED) Lake Chivero: A polluted lake, UZ publications, Harare.

Mukokeri, E. (1999) .The Sakubva River and its effects on the Dora secondary community. A research project submitted to the Geography department of Mutare Teacher’s college for a Diploma in secondary education, Mutare.

Skipton, S., Dvorak, B. and Woldt, W. (2005). Drinking water. Testing for quality of Nebraska-Lincolin extension.

Tagwira, F. (1998). A community Based Assessment of Sakubva River. Africa University Printing Press, Mutare.

Thomann, R., V. And Mullar, J., A. (1987). Principles of surface water quality control. Haper Collins, New York.

Trivedi, R., K. And Goel, P., K. (1986). Chemical and Biological methods for water pollution studies. Environment Publications.

WCED (1991). Our common future: World commission on environment and development. Oxford university press, Oxford.

World Health Organisation (WHO). (1990).Guidelines for drinking water quality, Health criteria and other supporting information, Geneva.

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APPENDICES Appendix 1: means from the three stations from December 2015 to April 2016 Station Month day DO N Temp pH Cond Tub Station 1 Dec 1 4.90 0.52 22.30 6.80 385 5.24 Station 1 Dec 2 5.57 0.51 22.50 7.00 388 5.30 Station 1 Jan 1 4.91 0.40 21.90 7.20 350 4.80 Station 1 Jan 2 5.75 1.29 21.75 6.53 345 5.10 Station 1 Feb 1 5.35 1.28 21.10 7.06 333 4.60 Station 1 Feb 2 5.00 0.35 22.40 7.09 340 7.10 Station 1 March 1 5.24 1.16 21.20 7.47 327 4.06 Station 1 March 2 5.86 0.48 21.40 7.90 349 5.24 Station 1 April 1 7.44 0.47 24.00 7.36 366 4.65 Station 1 April 2 6.58 0.66 21.30 7.16 379 4.90 Station 2 Dec 1 6.04 0.85 23.02 5.85 398 4.06 Station 2 Dec 2 4.80 0.51 22.20 6.60 293 5.20 Station 2 Jan 1 5.12 3.67 22.30 6.84 353 4.20 Station 2 Jan 2 2 4.80 0.51 22.20 6.60 303 6.90 Station 2 Feb 1 4.98 0.87 21.60 6.83 407 6.44 Station 2 Feb 2 5.70 1.25 21.40 7.79 385 4.20 Station 2 March 1 6.04 0.53 23.40 6.50 398 6.44 Station 2 March 2 6.80 1.60 21.80 7.92 402 5.22 Station 2 April 1 6.88 1.63 21.90 4.90 393 5.30 Station 2 April 2 7.40 0.45 21.20 7.18 360 4.80 Station 3 Dec 1 5.94 0.41 23.00 6.60 389 4.90 Station 3 Dec 2 5.25 1.12 21.30 7.45 324 4.05 Station 3 Jan 1 5.24 0.75 21.40 7.14 352 4.50 Station 3 Jan 2 5.15 0.70 21.30 6.81 305 6.40 Station 3 Feb 1 4.97 1.37 21.80 6.92 405 6.95 Station 3 Feb 2 6.02 1.17 21.70 7.42 400 4.60 Station 3 March 1 6.03 1.19 23.30 7.73 389 8.20 Station 3 March 2 6.01 0.52 22.30 8.02 399 6.50 Station 3 April 1 8.01 0.52 21.50 8.02 387 6.52 Station 3 April 2 6.56 0.64 21.60 8.84 378 6.51

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Appendix 2: Acceptance letter to carry out water quality tests in Sakubva River

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Appendix 3 Station 1 site located in greenside suburbs

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Appendix 4 Station two site located in Sakubva residential area.

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Appendix 5 Station three site located after Gimboki sewage works

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