ABSTRACT
Bacteriological examination of well water samples
located near septic tanks in Abakaliki metropolis was investigated. 15 well
water samples from 15 different wells were used for the research. Measuring
tape was used to measure the distance, the colour and physical appearance of
the water was observed with the naked eyes, the temperature was measured with
mercury thermometer and its pH was measured with pH indicator. Pour plate method
were used for the enumeration of viable bacterial cells in the well water while
most probable number (MPN) was used for the enumeration of coliforms.
Biochemical tests were employed in the identification of. E.coli. The highest distance of 23.17 meters and the shortest
distance of 5 metres of the wells from the septic pit were the range used.
Physical and bacteriological characteristics of the well water samples showed
that 9 (60%) had colour ranging from slightly milky to light brown while 6
(40%) is colourless. 10 (66.67%) had presence of particles and cloudy
appearance while 5 (33.33%) had no particles in them.The pH of the well waters
ranged from 6 to 8 with 10 (66.67) of samples having pH of 7. The temperature
range of the well water samples were between 31.80C to 37.00C.
Three samples (20%) presented odour. The highest standard plate counts of
2.9x105 cfu/ml were recorded while the lowest count was 3.8x104.
The highest most probable number (MPN) per ml was 0.36 and the least was 0.27.
Thirteen samples (86.67%) showed the presence of coliforms in them while five
samples (33.33%) showed the presence of E
coli. It was observed that all the well water sample that give positive E coli came from wells nearest to the
septic tank. Well water samples from wells that were 19 meter from the septic
tank and beyond did not give positive coliform or E coli. Recovering of E coli
from the well water samples may indicate contamination of the well waters from
the septic tank. It is therefore recommended that wells water should be sited
at least 19 meters from septic tank.
ENUMERATION OF COLIFORMS FROM WELL
WATERS LOCATED NEAR SEPTIC TANKS IN ABAKALIKI METROPOLIS, EBONYI STATE
A PROJECT SUBMITTED TO THE DEPARTMENT OF
APPLIED MICROBIOLOGY IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE AWARD OF
POSTGRADUATE DIPLOMA (PGD)
TABLE OF CONTENTS
Title
page i
Approval
Page ii
Certification iii
Dedication iv
Acknowledgements v
Abstract vi
Table
of contents vii
List
of Table xi
List
of Figures xii
CHAPTER ONE:
1.0.0
INTRODUCTION 1
1.1.0 Aim of the Research 4
CHAPTER TWO:
2.0.0 LITERATURE
REVIEW 5
2.1.0 Construction of Well 8
2.2.0 Classification of Well Water 10
2.3.0 Chemical and Physical Properties
of Water 11
2.4.0 Uses of Well Water 14
2.4.1 Agriculture 16
2.4.2 Drinking 16
2.4.3 Washing 17
2.4.4 Water Industry 18
2.4.5 Food Processing 18
2.5.0 Microorganisms
Associated with well Water 19
Contamination
2.5.1 Coliform
Bacteria 20
2.5.2 Giardia Lambia 21
2.5.3 Crptosporidium 23
2.5.4 Hepatitis 24
2.6.0 Sources of Contamination 26
2.7.0 Effect of Drinking Contaminated Well Water 26
2.8.0 The septic system 27
CHAPTER THREE:
3.0 MATERIAL
AND METHODS
3.1.0 Materials 29
3.1.1 Equipment 29
3.1.2 Media 29
3.1.3 Reagents 29
3.2.0 Study Area 29
3.3 Sample Collection 32
3.4 Analysis
of Physical Characteristics of the Well Water samples 33
3.4.1 Colour and Appearance 33
3.4.2 Determination of Temperature 33
3.4.3 Determination of pH 33
3.5.0 Microbiological Analysis 34
3.5.1 Standard Plate Count 34
3.5.2 Serial Dilutions 34
3.5.3.0 Enumeration of Total Coliforms 35
3.5.3.1 Multiple Tube Method 35
3.5.3.2 Presumptive Test 36
3.5.3.3 Confirmed Test 36
3.5.3.4 Completed Test 38
3.5.3.5 Identification of Escherichia coli Colonies on EMB
Agar plate 39
CHAPTER FOUR:
4.0 RESULTS
4.1 Physical Characteristics of the Well Water Samples 41
4.2 Standard Plate Count of the Well Water Sample 44
4.3 Result of the Presumptive Test and MPN of the Well
Water Samples 46
4.4
Colonial
Characteristic of the Organisms on Eosin
Methylene
Blue (EMB) agar 48
4.5 Identification of E coli 50
CHAPTER FIVE
5.0 Discussion 52
CHAPTER SIX
Summary, Conclusion and
Recommendation
6.1 Summary 55
6.2 Conclusion 55
6.3 Recommendation 56
Reference 58
Appendix: 63
LIST OF TABLES
1: Physical characteristics of the Well water
Samples 43
2: Standard plate count of the Well water samples 45
3: Result
of the presumptive test and MPN of the
Well water samples 47
4: colonial characteristics of the organisms on
Eosin methylene blue
(EMB) agar 49
5: Identification
of E. coil 51
LIST OF
FIGURE
Fig 1: Model
of hydrogen bonds between molecules of
Water………………………………………………. 3
Fig 2: Map of Ebonyi State showing the study Area… 31
Fig 3: Picture showing the growth characteristic and
colour of Coliforms
on slant Eosin Methylene Blue
(EMB) agar …….. …………………………………… 37
Fig 4: Picture showing well distance to septic tank…… 70