Apparatus for equalization of overflow water and urban runoff in receiving bodies of water

An apparatus for equalizing the flow of polluted water comprising a tank including a plurality of sequentially fluid connected compartments arranged in a body of water, a first compartment of said plurality being in communication with an inlet discharging polluted water at a variable rate of flow, and a last compartment of said plurality being in fluid communication with said body of water surrounding said tank such that water may flow either from said last compartment to said surrounding body of water or from said surrounding body of water into said last compartment, said tank being formed with generally vertical outer and intermediate walls, extending from the surface of said body of water to its bottom, which divide said tank into said plurality of compartments, said plurality of compartments being sequentially fluid connected by apertures provided in said intermediate walls and permitting fluid flow in both directions, a pump provided in said first compartment adjacent to the inlet for polluted water and connected to an outlet conduit for withdrawing water from said first compartment at a substantially constant rate of flow, whereby when the rate of discharge of said polluted water into said first compartment exceeds the rate of withdrawal of water by said pump, polluted water will sequentially displace water present in said compartments in a direction toward said surrounding body of water, while when the rate of discharge of polluted water into said first compartment is lower than the rate of withdrawal of water by said pump, water from said surrounding body of water will enter said last compartment and sequentially displace polluted water in the opposite direction toward said first compartment.