ANALYSIS OF THE IMPACT OF ANTHROPOGENIC POLLUTION ON SHALLOW GROUNDWATER IN PERI-URBAN KAMPALA Robinah Kulabako May 2005 TRITA-LWR LIC Thesis 2029 ISSN 1650-8629 ISRN KTH/LWR/LIC 2029-SE ISBN 91-7178-103-X Robinah Kulabako TRITA LWR LIC Thesis ii Analysis of the impact of Anthropogenic pollution on shallow groundwater in peri-urban Kampala DEDICATION This work is dedicted to my parents, husband, children, sisters, brothers and inlaws. ii i Robinah Kulabako TRITA LWR LIC Thesis iv Analysis of the impact of Anthropogenic pollution on shallow groundwater in peri-urban Kampala ACKNOWLEDGEMENTS First and foremost, I would like to express my sincere gratitude to Sida/SAREC for the financial support that has greatly made this research possible. Iam deeply indebted to my PhD supervisors: Professor Roger Thunvik and Dr. Mai Nalubega for the research discussions, constructive advices, and suggestions during the execution of this re- search and thesis write-up. You both have enhanced my capacity in more ways than you know, words are simply inadequate to express my sincere gratitude. Additional thanks go to Prof. Emeritus Klas Cederwall for his kind assistance and contribution during the initial stages of this research. I wish to acknowledge Prof. Bijan for the constructive ideas on pursuance of PhD research. My sincere thanks go to Prof. Leigh Soutter for the guidance and great contribution to the mod- elling aspects of the research. Am very grateful to Prof. Per Erik Jansson for the further insights into the use of the COUP Model and discussions on the research. To Joel, Rukia, Rita, Mr. Mukasa, Dauda, Peter2, David, and Boony, your extra hands and feet did not fail me during field and laboratory activities. Thank you very much for the support. In the same note I wish to thank the residents of Bwaise III who allowed me access to the area and availed land for installation of the monitoring wells. Additional thanks go to my fellow PhD candidates: JB, Umaru, Charles, Herbert and Assumpta for the encouragement that has kept me motivated. I wish to extend my gratitude to my fellow PhD candidates at LWR, KTH: Kirlna, Ola (and Joanne), Kristofer and the administrators: Britt and Aira who really made me feel at home away from home during my stay in Sweden. Lastly, my heartfelt thanks go to my family for the spiritual support. I wish to specially thank my husband Moses for his great encouragement and enduring my constant absences. To my children, Fina, Carol, Aldrian and Arnold, I thank you for a good attempt to understand my absence and welcoming me back with open arms. To God, without you, this truly would not have been! v Robinah Kulabako TRITA LWR LIC Thesis v i Analysis of the impact of Anthropogenic pollution on shallow groundwater in peri-urban Kampala TABLE OF CONTENTS DEDICATION................................................................................................................................................ III ACKNOWLEDGEMENTS.............................................................................................................................. V LIST OF ABBREVIATIONS ..........................................................................................................................IX ABSTRACT ........................................................................................................................................................ 1 1 INTRODUCTION........................................................................................................................................ 1 1.1 Background....................................................................................................................... 1 1.2 Problem statement ............................................................................................................ 3 1.3 Case study area - Bwaise III Parish.................................................................................... 3 1.4 Objectives......................................................................................................................... 3 1.5 Scope of study................................................................................................................... 4 1.6 Thesis layout ..................................................................................................................... 4 2 THE GROUNDWATER SITUATION IN KAMPALA................................................................................ 5 2.1 Introduction...................................................................................................................... 5 2.2 Topography ...................................................................................................................... 5 2.3 Geology ............................................................................................................................ 5 2.4 Hydrogeology characteristics............................................................................................. 6 2.5 Groundwater sources........................................................................................................ 7 2.6 Shallow groundwater quality.............................................................................................. 7 2.7 Pollution mitigation measures ........................................................................................... 9 3 LITERATURE REVIEW ..............................................................................................................................10 3.1 Introduction.................................................................................................................... 10 3.2 Groundwater................................................................................................................... 11 3.2.1 Hydrological aspects of groundwater (quantity and quality) .................................................. 11 3.2.2 Typical characteristics of the subsurface zones ..................................................................... 11 3.2.3 Subsurface flow hydraulics ................................................................................................... 12 3.3 Contaminant transport.................................................................................................... 16 3.3.1 Transport Mechanisms......................................................................................................... 16 3.3.2 Phosphorus retention.......................................................................................................... 18 3.4 Contaminant transport and related hydrogeological investigations .................................. 20 4 MATERIALS AND METHODS...................................................................................................................21 4.1 Introduction.................................................................................................................... 21 4.2 Field surveys and consultations ....................................................................................... 21 4.3 Monitoring (Observation) well installation ...................................................................... 21 4.4 Water and wastewater sampling....................................................................................... 22 4.5 Rainfall data collection .................................................................................................... 24 4.6 Soil sampling................................................................................................................... 24 4.7 Field measurements and Laboratory tests........................................................................ 24 4.7.1 Insitu-measurements and laboratory water and wastewater quality analysis........................... 24 4.7.2 Soil sample analysis .............................................................................................................. 25 4.8 Phosphorus adsorption experiments ............................................................................... 27 4.9 Data analysis ................................................................................................................... 28 5 RESULTS ...................................................................................................................................................... 29 5.1 Pollution source characteristics ....................................................................................... 29 5.1.1 Excreta disposal facilities...................................................................................................... 29 v ii Robinah Kulabako TRITA LWR LIC Thesis 5.1.2 Solid waste dumps................................................................................................................ 30 5.1.3 Sullage/stormwater drains.................................................................................................... 32 5.2 Shallow groundwater characteristics ................................................................................ 32 5.2.1 Monitoring well water level variations .................................................................................. 33 5.2.3 Spring discharge variations ................................................................................................... 33 5.2.3 Water quality variation.......................................................................................................... 34 5.2.4 Subsurface soil characteristics..............................................................................................