The Quality of Rainwater Collected from Roofs and the Possibility of Its Economic Use

The large temporal and spatial variability of rainwater quality, as well as the relatively small number of tests, makes the preliminary assessment of its economic exploitation difficult. Determining the relationship between the conditions and location of rainwater collection and rainwater quality would help indicate the range of options for rainwater use, as well as the parameters that require improvement. The aim of the presented article is to establish the physical, chemical, and microbiological parameters of different rainwater sources and, from the results obtained, determine the possibilities for its safe use in households. The research was carried out for two years. Samples of rainfall were collected from spring to fall from the following roofing materials: Concrete roof tiles, ceramic roof tiles, galvanized steel sheet, and epoxy-coated terrace. The physical, chemical, and microbiological quality were assessed on the basis of the pH, turbidity, electrical conductivity, the concentration of biogenic compounds, the concentration of chosen elements, the number of Escherichia coli, and the number of fecal streptococci. Significant bacterial contamination, decreased pH, and increased turbidity were identified in the water, depending on the parameters of the roofing washed by the rainfall and the intensity and frequency of precipitation.