Clog resistant storm drain filter

Claim 1

A removable storm drain filter to be used in combination with an absorbent media, and a catch basin having grated inlet and standpipe outlet, for purposes of removing pollutants carried in surface drainage, comprising: (a) a filtration vessel for containing absorbent media, said filtration vessel having solid side walls, a perforated bottom, and a perforated lid; (b) means for accessing said filtration vessel to permit inspecting and changing absorbent media; (c) bracing means for supporting said filtration vessel upon a standpipe; (d) sealing means for making a watertight seal between said bracing means and the standpipe; (e) weir means for creating sufficient pressure head upon said perforated lid to force the passage of storm water through said filtration vessel, and for bypassing high flows without disruption of the absorbent media; (f) a removable cover plate for dissipating kinetic energy of incoming storm water between the catch basin grated inlet and said filtration vessel, and for directing influent sediment away from said perforated lid; (g) means for supporting and securing said cover plate above and upon said filtration vessel; (h) floatables screen for preventing the accumulation of floating litter upon said perforated lid; (i) means for supporting and securing said floatables screen upon said filtration vessel; (j) means to facilitate installing, removing, and carrying the fully assembled apparatus by a human being; whereby sedimentation, straining of floating litter, and dissipation of kinetic energy occur prior to contact with absorbent media so as to prevent clogging and scouring of media, and flow control is provided to prevent scouring of media even during high flows.

Claim 13

A method for enhancing sedimentation and the removal of pollutants inside a storm drain catch basin with grated inlet and interior walls, using a removable and rechargeable storm drain filter comprising a filtration vessel having solid side walls, a perforated bottom and a perforated lid surrounded by a flotables screen, the method comprising the steps of: (a) placing an absorbent media within said filtration vessel; (b) positioning said storm drain filter below a grated inlet to a catch basin, and upon an upward terminus of a standpipe; (c) diverting surface drainage into the catch basin; (d) dissipating kinetic energy of influent surface drainage below the grated inlet without disruption of the absorbent media; (e) directing influent sediment to a settling zone comprising the space between a peripheral wall of the standpipe and the interior walls of the catch basin; (f) causing surface drainage to accumulate inside the catch basin, between the peripheral wall of the standpipe and the interior walls of the catch basin; (g) straining surface drainage through said flotables screen to prevent the accumulation of floating litter upon said perforated lid; (h) decanting accumulated surface drainage from the space between the peripheral wall of the standpipe and the interior walls of the catch basin, through said perforated lid and then through the absorbent media; (i) overflowing storm drainage flows that exceed the flow capacity through the absorbent media through an unobstructed conduit without disruption of the media; (j) discharging treated surface drainage through a conduit extending from the standpipe to the point of disposal; (k) removing said storm drain filter from the catch basin; (l) removing and replacing spent media; whereby sedimentation, straining of floating litter, and dissipation of kinetic energy occur prior to contact with absorbent media so as to prevent clogging and scouring of the media, and flow control is provided to prevent scouring of absorbent media even during high flows.

Claim 14

A method for enhancing sedimentation and the removal of pollutants inside a storm drain catch basin with grated inlet and interior walls, using a removable and rechargeable storm drain filter comprising a filtration vessel having solid side walls, a perforated bottom and a perforated lid surrounded by a flotables screen, the method comprising the steps of: (a) placing an absorbent media within said filtration vessel; (b) positioning said storm drain filter below a grated inlet to a catch basin, and upon an upward terminus of a standpipe; (c) diverting surface drainage into the catch basin; (d) dissipating kinetic energy of influent surface drainage below the grated inlet without disruption of the absorbent media; (e) directing influent sediment to a settling zone comprising the space between a peripheral wall of the standpipe and the interior walls of the catch basin; (f) causing surface drainage to accumulate inside the catch basin, between the peripheral wall of the standpipe and the interior walls of the catch basin; (g) straining surface drainage through said flotables screen to prevent the accumulation of floating litter upon said perforated lid; (h) decanting accumulated surface drainage from the space between the peripheral wall of the standpipe and the interior walls of the catch basin, through said perforated lid and then through the absorbent media; (i) overflowing storm drainage flows that exceed the flow capacity through the absorbent media through an unobstructed conduit without disruption of the media; (j) discharging treated surface drainage through a conduit extending from the standpipe to the point of disposal; (k) removing said storm drain filter from the catch basin; (l) removing and replacing spent media; whereby sedimentation, straining of floating litter, and dissipation of kinetic energy occur prior to contact with absorbent media so as to prevent clogging and scouring of the media, and flow control is provided to prevent scouring of absorbent media even during high flows.