ABSTRACT

Roof-harvested rain water (RHRW) has been considered as an effective alternative source of water for domestic use, as public source of water are not always available and consistent. However, the most significant issue in relation to using untreated (RHRW) for domestic purposes is the potential public health risks associated with microbial pathogens. This study focuses on comparative microbial assessment of roofs harvested rain water. A total of eighteen (18) water samples were collected and analyzed using microbiological standard method. The bacteria species implicated from the study are; Staphylococcus aurues, Escherichia coli, Bacillus spp, Streptococcus spp, Enterococcus spp and Shigella spp. The bacteria load ranges from 4.5x104 cfu/ml to 1.56x105 cfu/ml with thatch roof water sample having the highest bacteria load and stone coated roof having the least bacteria load. There was variation in the occurrence of the different bacteria species in the water samples studied. Staphylococcus aureus and Bacillus had the highest occurrence (33.3% to 100%), while shigella spp had the least occurrence of 0% to 33.3%.The prevalence of the microorganisms was highest in thatched roof water and least in the open air rain water. From the recorded observations in this study, it was concluded that rain waters from different roofs in and around Umudike are of low microbiological quality. Therefore, it was recommended that the roofs harvested rain water should not be drunk without treatment. Simple thermal treatment like boiling is suggested as well as filtration of the water.

TABLE OF CONTENTS

Title Page   i

Certification iii

Dedication iv

Acknowledgements v

Table of Contents vi

List of Tables vii

List of Figure viii

Abstract ix

CHAPTER ONE

Introduction 1

1.1 Aim and Objectives 5

CHAPTER TWO

2.0 Literature Review 6

2.1 Fecal Indicators and Pathogens in Roof-Harvested Rainwater 6

2.1.1 Fecal Indicators 6

2.2 Bacterial Pathogens 9

2.3 Protozoan Pathogens 11

2.4 Correlation between Fecal Indicators and Pathogens in Roof-Harvested 

Rainwater 12

2.5 Roof-Harvested Rainwater and Associated Health Risks 13

2.6 Management of the Risk of Infections Associated with the 

Use of Roof-Harvested Rainwater 18

CHAPTER THREE

3.0 Material and Methods 20

3.1 Study Area

3.2 Materials 20

3.3 Sample Collection 20

3.4 Media Used 20

3.5 Sterilization of Materials 20

3.6 Processing of Samples 21

3.7 Media Preparation and Isolation of Microorganism 21

3.7.1 Media Preparation 21

3.7.2. Sample Inoculation and Enumeration of Bacteria Load 21

3.7.3 Total Coliform Count 22

3.8 Microbial Characterization and Identification 23

3.8.1 Identification of Bacterial Isolates 23

3.8.1.1 Gram Staining 23

3.8.2 Biochemical Tests 23

3.8.2.1 Indole Test 23

3.8.2.2 Carbohydrate Utilization Analysis 23

3.8.2.3 Catalase Test 24

3.8.2.4 Oxidase Test 24

3.8.2.5 Coagulase Test 24

3.8.2.6 Citrate Utilization Test 24

3.8.2.7 Motility Test 24

3.9 Statistical Analysis 25

3.10 Determination of Occurrence 25

CHAPTER FOUR

4.0 Results 26

CHAPTER FIVE

5.0 Discussion, Conclusion and Recommendation 32

5.1 Discussion 32

5.2 Conclusion 34

5.3 Recommendations 34

References