ABSTRACT
Physicochemical and bacteriological analyses of borehole water samples
were randomly collected from ten boreholes which supply drinking water to
various communities of Aninri, Awgu and Oji River Local Government
Areas of Enugu, Nigeria. The boreholes were sampled in both dry and rainy
seasons. The following physicochemical parameters: pH, temperature,
colour, electrical conductivity, turbidity, total dissolved solids, hardness,
calcium, magnesium, sodium, potassium, alkalinity, acidity, lead, copper,
cadmium and iron were determined using standard methods. E. coli count
was determined by membrane lauryl sulphate broth method. Results of
physicochemical tests were in compliance with WHO guideline values,
except in the cases of sulphate level of 1,670 mg/L in water sample from
Mpu in Aninri L.G.A., high chloride levels in samples from Ndeaboh and
Mpu with values of 18,088 and 1,095 mg/L respectively. Similarly, sodium
was also very high in the two boreholes, 5,625 and 8,500 mg/L. The water
samples showed acid pH particularly in Oji River with values ranging from
4.30 to 6.30. Most of the water samples were soft waters, except samples
from Ndeaboh, Mpu and Mgbowo with hardness values of 6,250, 6,250 and
840 mg/L respectively. Trace metal concentrations were below WHO
guideline values, except samples from Mgbowo and Nnenwe with iron
values of 4.54 and 3.13 mg/L. E. coli was isolated in two boreholes located
in unkept surroundings in Oduma and Agbogugu with E. coli counts of 7
and 108 cfu/100 mL respectively. Generally, the borehole waters are
considered safe for drinking except these ones polluted with E. coli and
sodium chloride. The effects of unsafe drinking water are discussed, with
recommendations to the Authorities regarding the safety measures to be
applied.
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TABLE OF CONTENTS
TITLE PAGE i
CERTIFICATION ii
DEDICATION iii
ACKNOWLEDGEMENT iv
TABLE OF CONTENTS v
LIST OF TABLES ix
LIST OF FIGURE x
ABSTRACT xi
Chapter 1 1
1.0 INTRODUCTION 1
1.1 Groundwater as Source of Potable Water 2
1.2 Water Pollution 3
1.3 Study Area 4
1.4 Statement of the problem 5
1.5 Aim and Objectives 5
1.6 Justification of Study 6
Chapter 2 8
2.0 LITERATURE REVIEW 8
2.1 Groundwater is a source of Recharge for Boreholes 8
2.2 Groundwater and Dissolved Minerals 9
2.3 Sources of Groundwater Pollution 10
2.4 Bacteria and Borehole Contamination 14
2.5 Factors that Determine Groundwater Contamination 15
2.5.1 Properties of the Chemical Contaminant 15
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2.5.2 Properties of the Soil 16
2.5.3 Existing Condition at the Site 16
2.5.4 Human Actions or Practices 17
2.6 A Review of Water Pollution and Pollutants (Contamination) 18
2.7 General Review of the Chemistry of the Parameters
Determined 20
2.8 Water Evaluation 21
2.9 Analysis of Metals 22
2.9.1 Iron 23
2.9.2 Copper 24
2.9.3 Lead 25
2.9.4 Cadmium 25
2.9.5 Sodium 26
2.9.6 Potassium 27
2.9.7 Calcium 27
2.9.8 Magnesium 28
2.10 Physical Parameters 28
2.10.1 Colour 28
2.10.2 Turbidity 30
2.10.3 Temperature 30
2.10.4 Total Dissolved Solids 31
2.10.5 pH 31
2.10.6 Conductivity 32
2.11 Chemical Parameters 33
2.11.1 Total Acidity and Alkalinity 33
2.11.2 Hardness 36
2.11.3 Carbonates and Bicarbonates 37
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2.11.4 Chloride 38
2.11.5 Nitrate 39
2.11.6 Sulphate 40
2.11.7 Phosphate 41
Chapter 3 42
3.0 EXPERIMENTAL 42
3.1 Sampling 42
3.2 Preparation of Standard Solutions 44
3.3 Determination of Physical Parameters 44
3.3.1 pH 44
3.3.2 Conductivity 45
3.3.3 Temperature 45
3.3.4 Total Dissolved Solids 45
3.3.5 Colour 46
3.3.6 Turbidity 46
3.4 Determination of Chemical Parameters 46
3.4.1 Determination of Total Hardness 46
3.4.2 Determination of Calcium Hardness 48
3.4.3 Calculation of Calcium and Magnesium Concentrations 49
3.4.4 Determination of Total Alkalinity 50
3.4.5 Determination of Total Acidity 51
3.4.6 Determination of Phosphate 52
3.4.7 Determination of Sulphate 54
3.4.8 Determination of Nitrate 55
3.4.9 Determination of Chloride 56
3.4.10 Determination of Sodium and Potassium 58
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3.5 Determination of Trace Metals 59
3.5.1 Sources of Interference 60
3.5.2 Preparation of Samples 60
3.5.3 Determination of the Concentration of Cadmium,
Lead, Iron and Copper in the Water Samples 61
3.6 Bacteriological Analysis 62
Chapter 4 65
4.0 RESULTS AND DISCUSSION 65
4.1 Concentration of Trace Metals in the Samples 76
4.2 Bacteriological Quality of the Borehole Waters Analyzed 77
Chapter 5 79
5.0 CONCLUSION AND RECOMMENDATION 79-80
REFERENCES 81
CHAPTER ONE
1.0 INTRODUCTION
Water is one of the earth’s most precious resources. Water is often referred
to as a universal solvent because it dissolves many minerals. It can exist in
three states as liquid, gas (at 100 oC) and solid (at freezing temperature of <
4 oC). Water is fundamentally important to all plants, animals including
man1. Without it, there is no life. Good drinking water is not a luxury but
one of the most essential amenities of life. Although water is essential for
human survival, many are denied access to sufficient potable water supply
and sufficient water to maintain basic hygiene. Globally, over one billion
people lack access to clean safe water2,3,4. The majority of these people are
in Asia (20%) and sub-Sahara Africa (42%). Further, about 2.4 billion
people lack adequate sanitation worldwide 5.
It is estimated that > 80% of ill health in developing countries are water and
sanitation-related6. Thus, lack of safe drinking water supply and poor
hygienic practices due to lack of water are associated with high morbidity
and mortality from excreta-related diseases.
Consequently, water-borne pathogens infect around 250 million people each
year resulting in 10 to 20 million deaths world-wide5. An estimated 80% of
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all child deaths under the age of five years in developing countries result
from diarrhoea diseases7,8.
Lack of safe drinking water and inadequate sanitation measures could also
lead to a number of diseases such as dysentery, cholera and typhoid9,10.
Against this backdrop, the supply of safe drinking water to all has been at
the front burner at the United Nations Millennium Development Goals
(MDGs) to reduce poverty and promote sustainable development worldwide
especially in developing countries. Her target for water, is to halve by 2015,
the proportion of people without sustainable access to safe drinking water
and basic sanitation. However, it is envisaged that this target may not be
easy in developing countries because of (a) high population growth, (b)
conflict and political instability and (c) low priority given to water and
sanitation programmes in developing countries.
1.1 Ground Water as Source of Portable Water.
Water exists in several forms in the environment including sea water, seaice,
fresh water, and water vapour as clouds and mist. As water moves
through the environment it picks up gases and elements, flow to the sea and
through ground in an endless process known as the hydrologic cycle.
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The hydrological cycle ensures that water available on the earth is renewable
as it passes through a cycle of evaporation, condensation and ultimately back
to water in an endless cycle.
Groundwater occurs as part of the hydrologic cycle, which is the movement
of water between the earth and the atmosphere through evaporation,
condensation, transpiration and precipitation. The underground area where
water exists is referred to as an aquifer which is a layer of porous substrate
that contains and transmits groundwater11. Therefore, groundwater when
properly harnessed will provide consistent supplies of potable water because
it’s believed to be good.
1.2 Water pollution
Water pollution as defined by GESAMP (1988)12 means ‘‘the introduction
by man directly or indirectly of substances or energy which result in such
harmful effects as
· harm to living resources,
· hazards to human health,
· hindrance to aquatic activities including fishing,
· impairment of water quality with respect to its uses in agricultural,
industrial and often economic activities, and
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· reduction of amenities’’.
It can also be seen as anything whether physical or chemical that affects the
natural condition or the intended use of water. It is clear that water pollution
depends on the ultimate use to which the water in question will be put. In
other words, water which might be considered not polluted or satisfactory
for certain industrial use might very well be considered polluted or
unsatisfactory for drinking.
With increasing population, there is need for more water, and groundwater
has proved the most reliable resources for meeting dispersed rural water
demand in sub-Saharan Africa13. However, several practices such as the
application of fertilizers and agrochemicals, abandoned or inactive mine
sites, septic tanks, landfill etc, if not managed effectively could contaminate
and eventually pollute groundwater. The quality of water in boreholes is also
affected by the presence of heavy metals in the soil such as Pb, Mn, Cd, Cu,
Fe, Zn, Cr etc. There is also the problem of microbial pollution.
1.3 Study area
The study took place in Aninri, Awgu and Oji River Local Government
Areas of Enugu State, Nigeria. These Local Government Areas make up
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Aninri/Awgu/Oji River Federal Constituency. Geographically located within
Latitude 05o 55/ – 06o 20/ N and Longitude 07o 10/- 07o 40/ E. Aninri has clay
and loamy flat lands; Oji River has sandy flat lands, while Awgu has clay
and stony lands with hilly topography. Petty trading and subsistence
agriculture are the major occupation of the people. There is no notable
industry located in this area and its environs.
1.4 Statement of the Problem
· In spite of various researches conducted on groundwater (boreholes),
there is no published data available to determine the water quality of
the boreholes in Aninri, Awgu and Oji River Local Government Areas
of Enugu State.
· No evidence of any form of maintenance or any assessment carried
out on the quality of water being pumped.
1.5 Aim and Objectives
This study was to determine the quality of water from boreholes in this area
as to ascertain its safety for consumption in relation to standards set by the
World Health Organization (WHO) for drinking water.
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The objectives of this study are (i) to determine the quality of water from the
boreholes in Aninri/Awgu/Oji River Local Government Areas of Enugu
state, Nigeria, and (ii) provide baseline data of determined parameters for
future assessment.
The specific objectives were to:
· Determine the levels of these parameters in the borehole water: pH,
temperature, colour, odour, conductivity, total dissolved solids (TDS),
turbidity, total acidity, total alkalinity, hardness, SO4
2-, PO4
3-, Cl-,
NO3
-, K, Ca, Mg, Cd, Cu, Pb and Fe.
· Determine any significant seasonal variation on the parameters.
· Access the level of bacteria contamination in the boreholes.
· Compare the level of the parameters with WHO guideline values.
· Ascertain the possible causes of any contaminations in order to make
appropriate recommendations to alleviate the problem.
1.6 Justification of Study
Water supply sources for inhabitants of the Local Government Areas under
study include, supply from water tankers, stored rain water, streams and
borehole/well waters. However, because of population and urbanization,
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