water quality 138 WATER QUALITY 107 WATER SUPPLY 61 CLIMATE CHANGE 56 DRINKING WATER 54 groundwater 54 WATER RESOURCES 44 WATER SECTOR 42 POLLUTION 39 SURFACE WATER 39 POPULATION GROWTH 38 WATER SERVICES 38 HOUSEHOLDS 37 SANITATION SERVICES 37 water use 37 GROUNDWATER 36 SERVICE PROVISION 36 WASTEWATER TREATMENT 36 WATER 36 COST RECOVERY 35 SANITATION SECTOR 35 URBAN AREAS 35 water resources 35 UTILITIES 34 WATER SOURCE 34 SANITATION 33 water supply 33 SYSTEMS 32 WATER CONSUMPTION 32 WATER SERVICE 32