Ryszard Błażejewski Born in 1949 in Szczecin (Poland). Education: elementary school , then sanitary equipment technician; academic promotions: • M.Sc. in irrigation and drainage engineering, 1973, Agricultural University in Poznan (Poland); • Doctor of technical sciences in hydraulics and engineering hydrology, 1978, Hydro-reclamation Institute, Moscow (USSR); • habilitated doctor's degree in environmental engineering, 1991 - Cracow University of Technology, (Poland); • title of professor of technical sciences, 2001. Research areas: 1973-1991 – energy dissipation and local scour below hydraulic structures, river engineering; after 1991 – rural sanitation, small sewage treatment plants, alternative sewerage systems, two-phase (sedimentation, air-water) and three-phase flows, rainwater management, hydraulics of sewerage devices. Scientific achievements: author or co-author of approximately 200 articles in journals, 8 books and brochures, 3 patents. Former head of Dept. of Hydraulic and Sanitary Eng. at the Poznan University of Life Sciences, now retired. Supervisor of 9 doctoral theses and 151 master's theses. Member of the Environmental Engineering Committee of the Polish Academy of Sciences, a member of the Committee on Climate, Water Resources and Air Protection at the Great-Poland Branch of the PAS, vice-president for scientific affairs of the Polish Association of Sanitary Engineers and Technicians. Member of editorial teams of the following journals: Communes’ Infrastructure Review, Waterworks and Sewerage, Water Technology. Radosław Matz Born in 1976 in Poznan (Poland). Education: elementary school , then refrigeration technician; academic promotions: • M.Sc. in water and sanitary engineering, 2001, Agricultural University in Poznan (Poland); • Doctor of agricultural sciences in environmental shaping and engineering, 2006, Faculty of Land Reclamation and Environmental Engineering, Agricultural University in Poznan (Poland); Research areas: 2001-2010 – technical and economic optimization of sewerage systems in rural areas, evaluation of technical condition of sewerage systems; after 2010 – rural sanitation, alternative sewerage systems, two-phase (air-water) flows, hydraulics of sewerage devices with using computational fluid dynamics (CFD), management and modelling of storm water systems. Present position: assistant professor at the Dept. of Hydraulic and Sanitary Eng. , Poznan University of Life Sciences. Scientific achievements: author or co-author of approximately 40 articles in journals, 2 books and brochures, 2 patents. Supervisor of 40 master's theses.