Sanitation in unSewered urban poor areaS technology selection, quantitative microbial risk assessment and grey water treatment alex yasoni katukiza Sanitation in unsewered urban poor areas: technology selection, quantitative microbial risk assessment and grey water treatment Alex Yasoni Katukiza i Thesis committee Promotor Prof. Dr P.N.L. Lens Professor of Environmental Biotechnology UNESCO-IHE, Delft Co-promotor Dr M. Ronteltap Lecturer in Sanitary Engineering UNESCO-IHE, Delft Other members Prof. Dr G. Zeeman, Wageningen University Em. Prof. Dr W. Verstraete, Ghent University, Belgium Prof. Dr P.D. Jenssen, Norwegian University of Life Sciences, Ås, Norway Dr T.O. Okurut, National Environmental Management Authority, Kampala, Uganda This research was conducted under the auspices of the Graduate School for Socio- Economic and Natural Sciences of the Environment (SENSE) ii Sanitation in unsewered urban poor areas: technology selection, quantitative microbial risk assessment and grey water treatment Thesis submitted in fulfilment of the requirements of the Academic Board of Wageningen University and the Academic Board of the UNESCO-IHE Institute for Water Education for the degree of doctor to be defended in public on Friday, 29 November 2013 at 4 p.m. in Delft, The Netherlands by Alex Yasoni KATUKIZA born in Kabale, Uganda iii CRC Press/Balkema is an imprint of the Taylor & Francis Group, an informa business © 2013, Alex Yasoni Katukiza All rights reserved. No part of this publication or the information contained herein may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, by photocopying, recording or otherwise, without written prior permission from the publishers. Although all care is taken to ensure the integrity and quality of this publication and information herein, no responsibility is assumed by the publishers or the author for any damage to property or persons as a result of the operation or use of this publication and or the information contained herein. Published by: CRC Press/Balkema PO Box 11320, 2301 EH Leiden, The Netherlands e-mail: [email protected] www.crcpress.com – www.taylorandfrancis.com ISBN 978-1-138-01555-5 (Taylor & Francis Group) ISBN 978-94-6173-769-4 (Wageningen University) iv Dedication This thesis is dedicated to my children as a motivation for them to strive and achieve what they want in life. To my wife whose love and patience provided the strength I needed to progress. To my parents who valued education and enabled me to reach where they could not reach. v Acknowledgments This research was funded by the Netherlands Ministry of Development Cooperation (DGIS) through the UNESCO-IHE Partnership Research Fund. It was carried out at UNESCO-IHE, Delft (The Netherlands) and Makerere University, School of Engineering (Uganda) in the framework of the research project ‘Addressing the Sanitation Crisis in Unsewered Slum Areas of African Mega-cities' (SCUSA). I wish to express my sincere gratitude to my promotor Prof. Dr. ir. Piet Lens and supervisors Dr. ir. Mariska Ronteltap, Prof. Dr. Frank Kansiime and Dr. Charles Niwagaba for their strong scientific support, guidance and encouragement throughout the PhD research period. I will never forget the continuous critical comments from Prof. Dr. Piet Lens, that seemed to cause tough times but in the end enabled me to be critical, open minded and carryout multiple tasks with tight deadlines. I would like to thank Dr. Mariska again for her encouragement and scientific guidance during tough times and for the assistance in translating the summary into Dutch. I look forward to future research collaboration with my supervisors. I would like to thank the SCUSA project manager Assoc. Prof. Dr. Jan Willem Foppen for his scientific support and assistance during the course of the research. Thanks to my colleagues Philip Nyenje and John. B. Isunju with whom I passed through the hard times and enjoyed good times during the course of this research. I thank Fred Kruis, Peter Heerings and Lyzette Robbemont of UNESCO-IHE for their assistance in obtaining research equipment and laboratory consumables and Jolanda Boots for her assistance in transfering funds and obtaining airtickets. Thanks go to Dr. Kulabako Robinah for assistance with laboratory equipment and encouragement. The support provided by John Omara and Rita Nakazibwe during analysis of samples and by Fred Mukasa during construction of the filtration systems for the grey water treatment is highly appreciated. The following carried out their MSc. research within the framework of this SCUSA project 1 and their contribution is appreciated: Albert Oleja, Hayeloum Temanu, Olivier Goldschmidt and Henrietta Osei-Tutu. I thank my wife Joan and our beloved children Jethro Mugume and Ashley Abindabyamu for their love, support, prayers and also patience during my absence while abroad. To my parents and siblings, in-laws and close friends; thank you for your prayers, support and love. Alex Y. KATUKIZA Delft, 29 November 2013 vi vii Abstract The sanitation crisis in unsewered urban slums of cities in developing countries is one of the challenges that need to be addressed. It is caused by the high rate of urbanisation in developing countries and the increasing urban population with limited urban infrastructure. The major issues of concern are the collection, treatment and safe disposal of excreta, grey water and solid waste. The goal of this study was to contribute to the sanitation improvement in urban slums with focus on sanitation technologies. A review of sanitation technology options for urban slums was made followed by a baseline study in the slum of Bwaise III in Kampala Uganda. The results from the situation assessment and analysis were used to develop a method for selection of sustainable sanitation technologies in urban slums. Quantitative microbial risk assessment was then carried out based on the sources and concentration of pathogens and indicator organisms in the slum environment. The risk of infection and the disease burden contribution from various exposure pathways were determined. The study then focused on grey water treatment using a low-cost media (sand, crushed lava rock) based systems at laboratory scale and household level in the study area. The results showed that existing facilities in Bwaise III are unimproved and do not function as elements within a sanitation system. In addition, there is no system in place for grey water management. There was also wide spread viral and bacterial contamination in the area. The maximum concentration of human adenoviruses F and G (HAdV-F and G) rotavirus (RV) was 2.65x101 genomic copies per mL (gc mL-1) and 1.87 x102 gc mL-1, respectively. The concentration of Escherichia coli and Salmonella spp. ranged from 3.77x104 cfu. (100 mL)-1 to 2.05x107 cfu. (100 mL)-1. The disease burden from each of the exposure routes in Bwaise III slum was 102 to 105 higher than the World Health Organisation (WHO) tolerable risk of 1x10-6 disability-adjusted life years (DALYs) per person per year. Grey water generated in Bwaise III amounted to 85% of the domestic water consumption and was highly polluted with a COD and TN concentration range of 3000-8000 mg.L-1 and 30-50 mg.L-1, respectively, and Escherichia coli (E. coli) concentration of up to 2.05x107 cfu. (100 mL)-1. Grey water treatment with a crushed lava rock filter and using a two-step filtration process, resulted in the COD and TSS removal efficiencies of 88% and 90%, respectively, at a constant Hydraulic Loading rate (HLR) of 0.39 m.d-1 In addition, the highest removal efficiencies of TP and TKN were 59.5% and 69%, respectively, at a HLR of 0.39 m.d-1. A log removal of E. coli, Salmonella spp. and total coliforms of more than 3 (99.9%) was also achieved under household filter usage conditions. viii These results show that grey water treatment using a two-step crushed lava rock filter at household level in an urban slum has the potential to reduce the grey water pollutant loads by 50 % to 85%. However, its impact on public health and the environment needs to be assessed after its wide application. The need for advanced removal of pathogens and micro-pollutants from grey water warrants further research. In addition, the management systems for other waste streams of excreta and solid waste need to be in place as well to achieve the desired health impacts in urban slums. Integration of quantitative microbial risk assessment (QMRA) in the selection process of sustainable sanitation technologies for urban slums is recommended for future studies aimed at providing a holistic approach for upgrading slum sanitation. This will help to further understand the health impacts and benefits of sanitation solutions and also provide support to local authorities in making decisions on the measures to reduce the disease burden and environmental pollution. ix