QUALITY CHARACTERISTICS OF UNDERGROUND WATER RESOURCES IN NKANU EAST AND NKANU WEST LOCAL GOVERNMENT AREAS OF ENUGU STATE, NIGERIA.
ABSTRACT:
Physicochemical and bacteriological analyses of underground water resources in Nkanu East and Nkanu West Local Government Areas of Enugu state, Nigeria were carried out to evaluate the potability and quality of the rural water supplies and to provide baseline data for future quality assessment. Underground water samples were collected from ten different boreholes in Nkanu East and Nkanu West LGAs. The parameters measured include temperature, colour, pH, electrical conductivity, turbidity, total dissolved solids, total hardness, calcium hardness, magnesium hardness, total alkalinity, chloride, sulphate, phosphate, nitrate, sodium, potassium, lead, chromium, copper, cadmium, nickel, iron, zinc and total coliform. The water showed near neutral pH (6.4- 8.2) favourably comparable to the WHO recommended range of 6.5-8.5, with moderate permanent hardness of 2.5-289 mg/L. Conductivity and total dissolved solids values for Amechi Idodo (4360 μs/cm, 2650 mg/L) and Mbulu Owo (4880 μs/cm, 2930 mg/L) were higher than the WHO guideline values of 1660 μs/cm and 1000 mg/L, respectively. Concentrations of most trace metals and all anions were below the WHO guideline values. However, iron,cadmium and chromium occurred at levels slightly above the WHO permissible limit. Total coliform count in Amechi Idodo and Mbulu Owo exceeded the WHO guideline value of zero. The underground waters studied are good for drinking provided they are boiled to remove microbial contamination.
TABLE OF CONTENTS
Title Page i
Approval Page ii
Certification iii
Dedication iv
Acknowledgement v
Abstract vi
Table of Contents vii
List of Tables xi
List of Figures xii
CHAPTER ONE
1.0 Introduction 1
1.1 Underground water quality 1
1.2 Background of Study 2
1.3 Scope of Study 3
1.4 Objective of Study 4
CHAPTER TWO
2.0 Literature Review 5
2.1 Water 5
2.1.1 Properties of water 5
2.1.2 Uses of Water 6
2.2 Types of water resources 7
2.2.1 Underground water 7
2.2.2 Surface water 8
2.2.3 Water in the atmosphere 12
2.3 Pollution 12
2.3.1 Water pollution 13
2.3.1.1 Organic pollutants 13
2.3.1.2 Inorganic pollutants 15
2.3.1.3 Sediments pollutants 16
2.3.1.4 Radioactive materials 16
2.3.1.5 Thermal pollutants 17
2.3.2 Underground water pollution/pollutant 17
2.3.2.1 Point-source pollution 19
2.3.2.2 Non-point source pollution 19
2.3.2.3 Chemical pollution 21
2.3.2.4 Biological pollution 22
2.3.2.5 Physical/Natural pollution 24
2.4 Water Analysis 25
2.4.1 Physical examination 25
2.4.1.1 Temperature 25
2.4.1.2 Turbidity 25
2.4.1.3 pH 27
2.4.1.4 Total dissolved solids 27
2.4.1.5 Conductivity 28
2.4.1.6 Colour 28
2.4.2 Chemical examination 28
2.4.2.1 Hardness 28
2.4.2.2 Alkalinity 30
2.4.2.3 Calcium 30
2.4.2.4 Magnesium 31
2.4.2.5 Chloride 31
2.4.2.6 Nitrate 31
2.4.2.7 Phosphate 32
2.4.2.8 Potassium 32
2.4.2.9 Sulphate 33
2.4.2.10 Sodium 33
2.4.2.11 Cadmium 34
2.4.2.12 Chromium 35
2.4.2.13 Copper 36
2.4.2.14 Iron 37
2.4.2.15 Lead 38
2.4.2.16 Nickel 38
2.4.2.17 Zinc 39
2.4.3 Microbiological examination ` 39
CHAPTER THREE
3.0 Materials and Methods 41
3.1 Sample collection 41
3.2 Method of analysis 43
3.2.1 Turbidity 43
3.2.2 Temperature 43
3.2.3 Colour 43
3.2.4 Total dissolved solid 43
3.2.5 pH 44
3.2.6 Conductivity 44
3.2.7 Total alkalinity 44
3.2.8 Total hardness 45
3.2.9 Calcium 46
3.2.10 Magnesium 47
3.2.11 Chloride 47
3.2.12 Nitrate 48
3.2.13 Sulphate 49
3.2.14 Phosphate 49
3.2.15 Sodium 50
3.2.16 Potassium 50
3.2.17 Heavy metals determination 51
3.2.18 Bacteriological examination 52
CHAPTER FOUR
4.0 Results and Discussions 53
4.1 Turbidity 55
4.2 Colour 55
4.3 Conductivity 57
4.4 Total dissolved solid 57
4.5 pH 58
4.6 Total hardness, calcium hardness and magnesium hardness 59
4.7 Total alkalinity 61
4.8 Nitrate 62
4.9 Phosphate 62
4.10 Sulphate 63
4.11 Chloride 63
4.12 Sodium and potassium 64
4.13 Heavy metals 67
4.14 Total coliform 69
Conclusion and Recommendation 69
References 71
CHAPTER ONE
1.0 Introduction
1.1 Underground water quality
Water is the matrix of life and forms the bulk of the weight of the living cells. The resources of usable water have been diminishing and are unable to meet the variety of needs of modern civilization. Water as the carrier of pathogenic microorganisms, can cause immense harm to public health. Waterborne diseases include typhoid and paratyphoid fever, dysentery and cholera, polio and infectious hepatitis [1].
Many developing countries are witnessing a stage of development where water from shallow wells and boreholes are gradually supplementing the original sources of drinking water (surface water). The preference for underground water to surface water is borne out of the belief that before underground water can be distributed as tap water it must always be subjected to some purification, while in practice, underground waters are filtered by natural processes as they pass through columns of soils, sands, strata, or sedimentary layers of rocks and are usually clear of solid materials as they come from the aquifer, particularly if they are deep seated ones. The intricate pore spaces or water passage ways of the aquifer materials act as a fine filter and remove small particles of clay or any other fines [2]. Organic materials decay or are destroyed in transit. Thus, the dirtiest and most polluted sewage water may become clear of suspended/particulate solid materials once it has gone through a thick bed of sand or geologic and pedologic units. As a result of this natural self-cleansing of polluted water by deep-seated aquifers, physical and biological aspects of pollution may not pose serious problems in underground waters [2].
Thus, underground water may not be treated before use and is believed to be free from pollution. In spite of all this, underground waters may have pollutants that not only depend on the geology, pedology, and mineralogy of the formations it flows through but also on the constituent pollutants/contaminants in the water that recharges the underground water. Unsatisfactory colour and taste are easily detected and are good indicators for underground waters of poor quality. Some underground waters taste of iron, others may have a disagreeable odor. Borehole waters must, as a rule, be analyzed for chemical contaminants before the water is distributed and supplied to households [2].
1.2 Background of Study
The area of study is Nkanu East and Nkanu West. A Local Government Area in Enugu State, Nigeria, Nkanu East borders Ebonyi State to the east. Its Headquarters is Amagunze. It is a rural area with a population of about 148, 774 and land mass of approximately 795 km2.. Nkanu West has its Headquarters at Agbani. It has an area of 225 km2 and a population of 146,695. The major occupation in these areas is farming. The various communities making up the two local government areas live in small villages, which still have considerable natural surroundings. Although there are springs and streams, most of the communities rely on boreholes for their water supply due to proximity and modernity [3].
Due to increased use of fertilizers and pesticides in this areas part of which is leached into the underground water through the soil, there is increased risk of pollution of these boreholes. Enugu, the state of study was previously mined for coal and underground water pollution is an ever present risk in areas of mining. Also most of the people use pit toilets which are sources of underground water pollution [2].
1.3 Scope of Study
Samples of water from ten boreholes in the two LGAs specifically in Amechi Idodo, Mbulu Owo, Umueze, Agbani, Ugbawka, Isiogbo Nara, Akpugo, Amurri, Nara Unateze and Amodu Awkunanaw are to be collected. Physicochemical, bacteriological and trace metal analysis comprising of temperature, colour, pH, electrical conductivity, turbidity, total dissolved solids, total alkalinity, total hardness, calcium, magnesium, chloride, nitrate, phosphate, sulphate, sodium, potassium, total coliform, lead, copper, zinc, chromium, cadmium, and nickel are to be undertaken and values obtained are to be compared with World Health Organization (WHO) guideline values.
1.4 Objective of Study
There are yet no reported physicochemical or bacteriological studies of underground water resources in Nkanu East and Nkanu West Local government Areas. Therefore we set out to analyze borehole water samples from these areas in order to ascertain the potability and safety of the water by comparing the concentration levels with set standards and to procure the present quality status as baseline data for future periodic monitoring of the underground water quality in this area.
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