Sustainable Integrated Water Management Model with Public Health Strategies Yajaira Yanet Basulto Solis Submitted in accordance with the requirements for the degree of Doctor of Philosophy The University of Leeds School of Civil Engineering October 2015 The candidate confirms that the work submitted is her own and that appropriate credit has been given where reference has been made to the work of others. This copy has been supplied on the understanding that it is copyright material and that no quotation from the thesis may be published without proper acknowledgement. © 2015 The University of Leeds and Yajaira Yanet Basulto Solis The right of Yajaira Yanet Basulto Solis to be identified as Author of this work has been asserted by her in accordance with the Copyright, Designs and Patents Act 1988. ii Acknowledgements I gratefully acknowledge the co-funding received from the National Council for Science and Technology, Mexico–CONACyT and the Council for Science, Innovation and Technology of the Yucatan State -CONCIYTEY for the development of this PhD project, which was self-motivated, and aims to contribute to the water and health issues of this study area in Yucatan, Mexico. I would like to thank my supervisors for their time and guidance dedicated to my research, and for their invaluable constructive criticism received throughout this journey, this project would not have been possible without their input. I am sincerely grateful to Dr Julia Pacheco Avila, and Dr Roger Gonzalez Herrera for their guidance and support from the distance, for all valuable input data they provided to support my research work. I thank widely all the field researchers from my case study, at Faculty of Engineering, Autonomous University of Yucatan, Mexico, for all the valuable information. Furthermore I would also like to acknowledge with much appreciation two local research projects "Protection of peripheral areas and influencing area of the water supply wells fields for the current supply of the Metropolitan Area Mérida” No. YUC-2009-CO7-131955; and “Hydrogeological reserves for the supply of quality water to the Metropolitan Area of Mérida, Yucatán” No. YUC-2008-C06-108520, for the data provided which were key inputs for this research. At Leeds, I thank my very lovely officemate Mingfu and Gloria; they were part of my family on my daily life at Leeds. I would also like to thank all friends I met at Leeds who made university life such a special and fulfilling time. I would like to acknowledge the support and assistance of every people at the School of Civil Engineering. At home, I express my warm thank to my family and friends, for their invaluable enthusiasm and encouragement, they keep me motivated all along the way. A special thanks to Roland who makes this work comes true by being a source of constant encouragement, with his immeasurable support offered throughout my PhD. Thanks to God for guiding me and providing me this opportunity and all supportive people to make this research idea comes true. iii Abstract Water management is a global challenge. Important facts of current concern in the water sector are: water scarcity threatened by the increasing consumption, safe drinking water supply resources threatened by climate changes and pollutants discharged from anthropogenic activities; and the accelerated urbanisation demanding adequate water supply together with the increasing wastewater generated by the growing urban population. These issues are becoming an imperative need that could be effectively addressed through adaptive water management strategies for the sustainable development of the societies worldwide. Metropolitan areas exemplify the rapid increase of urban population within a relative small area, which consequently results in the overexploitation of water supplies. Together with this overexploitation, human health could be threatened due to the water-health nexus in terms of water quality and quantity. The specific case study of this research: the Metropolitan Area of Merida (MAM) in Yucatan, Mexico has been analysed in order to exemplify the use of a decision maker’s tool to improve public health through the identification of major water pollutants and correlate them with waterborne diseases documented in epidemiologic statistics. The focus of this research was on two indicator contaminants: Faecal coliforms as microbial indicator of water quality, representing the non-conservative pollutants, and nitrate as chemical indicator of water quality, an example of a conservative pollutant that may persists in the groundwater for decades. Seven engineering interventions have been tested to identify most suitable management strategies through the following steps: 1. Quantify pollutants in the aquifer with the Sustainable Integrated Water Management Model (SIWMM), using a system dynamics approach; 2. Outcomes of the model served to quantify a) Public health risks posed from faecal coliforms through Quantitative Microbial Risk Assessment (QMRA), and b) Economic savings associated with pollutants reduction, 3. Develop cost benefit analysis of selected interventions, and 4. Identify the most suitable intervention in order to assist decision makers to cope with a sustainable supply of safe water and an integrated water management. The model framework developed in this thesis identifies the installation of soil absorption systems into septic tanks at household level, and installation of treatment plants for livestock wastewater as the most cost-benefit interventions of substantial positive impacts on groundwater quality and public health and, in addition, economic benefits. iv Contents Acknowledgements ................................................................................................................................................. ii Abstract ................................................................................................................................................................... iii Contents ................................................................................................................................................................. iv List of Tables .......................................................................................................................................................... vi List of Figures ........................................................................................................................................................ viii List of Acronyms and Abbreviations ........................................................................................................................ xi List of Units and Definitions ................................................................................................................................... xiii Chapter 1. Introduction ............................................................................................................................................ 1 1.1. Global water crisis ................................................................................................................ 1 1.2. Water management challenges ............................................................................................ 2 1.3. Water-health nexus .............................................................................................................. 4 1.4. Aims and objectives ............................................................................................................. 4 1.5. Thesis outline ....................................................................................................................... 5 Chapter 2. Literature review .................................................................................................................................... 7 2.1. Water management ............................................................................................................. 7 2.1.1. Sustainable approach ............................................................................................. 8 2.1.2. Integrated approach ............................................................................................... 8 2.1.3. Groundwater management ................................................................................... 12 2.1.4. Groundwater critical hazards ................................................................................ 15 2.1.5. Karstic aquifer ...................................................................................................... 17 2.2. Engineering interventions ................................................................................................... 18 2.3. Water and public health ..................................................................................................... 19 2.3.1. Drinking water contaminants ................................................................................ 20 2.3.2. Transmission of water-related diseases ................................................................ 24 2.3.3. QMRA .................................................................................................................. 25 2.4. Modelling contaminant concentrations in groundwater ....................................................... 26 2.4.1. Nitrate .................................................................................................................. 26 2.4.2. Faecal coliform ....................................................................................................