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

                                                                                      Pages

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. 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

• 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

• 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

• 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