Time and Spatial Variability in Concentrations of Selected Pollutants in the New Bypass Rainwater Harvesting System

Abstract

The level of pollution and the variability of rainwater runoff quality collected in reservoirs next to the new Lublin bypass (south-eastern Poland) were assessed in this scientific paper. In the rainwater harvesting and treatment system, two types of reservoirs with different construction, size and presence of pre-treatment devices were used. Laboratory tests involved selected physical, oxygen, biogenic, salinity indicators, heavy metals and polycyclic aromatic hydrocarbons. Particularly large variability in concentrations included NO2-, TP, PO43-, K+ and Cl-. Parameters decreasing the water quality were mainly conductivity, BOD5, COD, NO2-, TP and Cl-. High concentrations of salt and phosphorus in collected rainwater require great care in final management (risk of salinization and eutrophication). In the second year of research, there was significant deterioration of water quality, which may result from different weather conditions and gradual accumulation of pollutants in new reservoirs. Not many significant differences were found in the quality of water collected in reservoirs with pre-treatment and without it. Loads of heavy metals and aromatic hydrocarbons in reservoirs were relatively small. However, these impurities have high durability and the ability to accumulate in the environment. Therefore, further studies should also take into account monitoring of bottom sediments and areas adjacent to the bypass.