Separation of oil, water and produced solids occurs if rain, wash down or produced water flows through a series of baffle plates, which extend to the center of the caisson. The baffle plates are spaced ten feet apart and form quiescent zones for the oil to coalesce and rise through the oil relief hole. The coalesced oil particles must then be large enough to overcome the exit velocity created by the inlet flow.

Oil particles with a rate of rise less than the exit velocity of the incoming flow will be remixed with the inlet flow resulting in effluent concentrations ranging from 65 PPM to 400 PPM.

A Hydro Pile is ideal for applications where there is continuous flow and have minimal discharge regulations.