Particle removal in detention ponds modelled for a year of successive rain events

Paper in proceeding, 1998

The aim of this study was to model the removal of pollution in small open stormwater detention ponds by a simple method of particle settling. Simulations were made with a rain series for a normal hydrological year selected from a 19-year long rainfall series. TSS removal calculations were based on the US EPA-method. Measured TSS concentrations from the Järnbrott detention pond were used for comparison with the modelled concentrations. The model work showed that the removal efficiency is strongly dominated by inter-event settling. Removal efficiency may be improved by increasing the specific pond area up to 150 m2/ha. A consideration of the particle density has to be made since the removal efficiency is affected by low densities, often seen for urban runoff sediments.