Patent ID: 7708149

Claim:
Apparatus for cleaning runoff water, comprising: a first tank for receiving the runoff water to be cleaned, a second tank located in said first tank, said second tank being a vertical tube that is open at its lower end to receive runoff water from said first tank, said second tank being closed at its upper end, a water cleaning device located in said second tank and through which the runoff water to be cleaned must pass as the water level rises in said second tank, and an output conduit for receiving the runoff water that has passed through said water cleaning device, and discharging said water, said output conduit is a tube which passes through said water cleaning device, said water cleaning device comprising a filtering layer of filtering material in the form of a spiral and positioned so that the runoff water to be filtered passes through said filtering layer, said water cleaning device including a spiral input layer running the length of the spiral filtering layer and which has a lower end that contacts water in said first tank, said spiral input layer feeds that water to said filtering layer, said input layer being sealed in its upper end to thus force the water through said filtering layer of filtering material, and said second tank defines a space above said water cleaning device for enclosing air and water.