I've just been involved in a FEED study for the treatment of storm water released from bunded areas. The final report recommended a pumped solution that is: Water would be gravity fed to a pump and then passed through a parallel plate separator before going to public drain. The pump offered total control over which water would leave the site. In short, the client hated the solution(cost) and wants a gravity feed solution only (no pump). Unfortunately the site is not flat and the bunds are at the top of a 30 degree slope. At the bottom of the slope is a public road, drain and a fence. OK in order to achieve gravity fed solution we must put the separator below the bund water levels. This puts the separator 5m from the fence and road. Now in this position calcs show that we can get water to the separator quicker than I can get water from it. Thus we must restrict the flow to the separator. This means that water will spend longer in the bund and the bund level may wet the bottom of the tanks (12000m^3 each). Can anyone tell me or point me in the direct of information that says whether this is an issue. To me this doesn't sound right, but the client seems to think that allowing water under the tanks is not a problem?????? Thanks for any assistance