Comparison between the separating efficiency of an improved high-side weiroverflow and a hydrodynamic Storm King (TM) separator

Scale model tests were used to determine the efficiency relationships for a hydrodynamic separator (Storm King(TM)) and a high-side weir overflow. Wit h the help of these relationships optimal dimensions of an improved high-si de weir overflow chamber could be found. The steady state efficiency for th is improved overflow chamber seems to be comparable to mat of a hydrodynami c separator, when both devices are subjected to the same surface load. On t he other hand, during real storm events, the storage inside the overflow st ructure can play an important role. This role is investigated by calculatin g the removal efficiencies for both structures when 4 monitored storm event s are used as input. When higher removal efficiencies are wanted, the stora ge effect gets more and more important and as a consequence the hydrodynami c separator can technically as well as economically compete with simpler st ructures like e.g, a high-side weir overflow. These findings are confirmed by a simple construction cost estimation. (C) 1999 Published by Elsevier Sc ience Ltd on behalf of the IAWQ. All rights reserved.