Experiments with Unconventional Storm Overflows

Models of four typical jet siphon type stilling pond storm overflows, the bypass being through an air regulated siphon, were tested. The main aim of the present experiments was to reduce the flow of solids through the bypass siphon and also to reduce the saturation of the stilling ponds with light solids. To obtain a comparison of the performance of different models, several hundred polymer beads of various densities were introduced into the upstream system of the overflow. The efficiency of the storm overflow, defined as the fraction of the solids not discharged through the bypass siphon, was then estimated. On one model, influence of the location of the bypass siphon on the efficiency of the system also was investigated.