Pollutants in rainwater runoff in Korea: their impacts on rainwater utilization.

Frequent urban floods and insufficient water supply have led to developing technologies for rainwater utilization in order to buffer extreme runoff situations in the watercourses and to provide an ongoing water supply for non-potable use. However, little information is available on the water qualities and runoff properties of collected rainwater in connection with efficient design and maintenance strategies of rainwater utilization systems. In this work, the characteristics of rainwater were investigated in a full-scale rainwater utilization facility in Korea. Samples of runoff rainwater from various catchment surfaces were analyzed for physico-chemical and microbial determinants including metals, nutrients, pH, turbidity, conductivity, and microorganisms. The pollutant concentrations in rainwater storage tank were also monitored to elucidate the impact of input rainwater quality on stored water property. It is likely that particles and total coliforms are major issues in operating rainwater utilization system. However, further studies will be necessary to address the health effect of rainwater in terms of microbial and ecotoxicological measures.