The 9th International Conference WATER FOR ALL was held on the 19-20 May 2022 in Osijek, in the Faculty of Agrobiotechnical Sciences Osijek on the occasion of World Water Day and with the aim of gathering and exchanging experiences of scientists and experts in the field of water management, environmental protection, and preservation of water resources. The Conference included plenary, oral, and poster sessions, and the presentations of sponsoring companies. 9th International Conference WATER FOR ALL was organized by the Josip Juraj Strossmayer University of Osijek, Faculty of Food Technology Osijek and Faculty of Agrobiotechnical Sciences Osijek, Faculty of Civil Engineering and Architecture Osijek, Croatian Chamber of Economy, Croatian Water - VGO, Croatian Chamber of Health Professionals, Croatian Water Pollution Control Society, Department of Biology of the Josip Juraj Strossmayer University of Osijek, Department of Chemistry of the Josip Juraj Strossmayer University of Osijek, University of Bihać, Faculty of Agriculture and Food Technology University of Mostar, Faculty of Health Studies University of Sarajevo, Faculty of Technology University of Tuzla, Nature Park “Kopački rit”, Public Institution for nature protection in Osijek-Baranja County, Public Health Institute of the Osijek-Baranja County, Health Center Osijek and Vodovod-Osijek d.o.o. The international co- organizers of the Conference were the International Federation of Environmental Health (IFEH), European Hygienic Engineering & Design Group (EHEDG) and Danube Parks. The theme of World Water Day 2022 and 9th International Conference WATER FOR ALL was "Groundwater – making invisible visible”.