1. Centre for Environmental Health and Engineering, Department of Civil and Environmental Engineering, University of Surrey, Guildford GU2 5XH, UK
2. Department of Geography and Urban Planning, School of Architecture and Built Environment, College of Science and Technology, University of Rwanda, Kigali P.O. Box 3900, Rwanda
3. Department of Civil and Environmental Engineering, Kyambogo University, Kyambogo Road, Kyambogo, Kampala P.O. Box 1, Uganda
4. Environmental Regulatory Research Group, School of Law, University of Surrey, Guildford GU2 7XH, UK
5. British Geological Survey, Wallingford OX10 8BB, UK