Patent ID: 7025887

Claim:
A sand filter treatment facility, which is buried in the ground, for removing toxic metals from storm water, comprising: (a) a rectangular shaped concrete base; (b) four concrete side walls which extend vertically upward from said concrete base, said four concrete side walls being attached to one another to form a rectangular shaped assembly of upstanding concrete side walls having an interior space; (c) first and second concrete inner walls positioned within the interior space of said assembly of upstanding concrete side walls, said first and second concrete inner walls being parallel and extending vertically upward from said concrete base; (d) first and second pretreatment chambers located within the interior space of said assembly of upstanding concrete side walls on opposite sides of said first concrete inner wall, said first concrete inner wall including a fluid passageway in proximity to the bottom end of said first concrete inner wall to allow for fluid flow from said first pretreatment chamber to said second pretreatment chamber; (e) an absorbent chamber located within the interior space of said assembly of upstanding concrete side walls adjacent said second pretreatment chamber on an opposite side of said second concrete inner wall, said second concrete inner wall including a fluid passageway in proximity to the upper end of said second concrete inner wall to allow for fluid flow from said second pretreatment chamber to said absorbent chamber; (f) a rectangular shaped ground level concrete cover mounted atop said assembly of upstanding concrete side walls; (g) an inlet grate located at ground level within said concrete cover above said first pretreatment chamber; (h) a porous collection pipe having a plurality of openings, said porous collection pipe being positioned at the bottom of said absorbent chamber and passing through one of said four side walls into the ground to allow for fluid flow from said absorbent chamber into the ground; (i) an absorption bed consisting of first, second and third layers of absorbent materials stacked one on top of another within said absorbent chamber above said porous collection pipe, said first, second and third layers of absorbent materials removing fine particles of said toxic metals from said storm water to provide clean water to said collection pipe; and (j) a paved apron having one end terminating at the sidewall adjacent said inlet grate, said paved apron being sloped at approximately seven percent to allow said storm water to drain into said first pretreatment chamber of said sand filter treatment facility, and the opposite edge of said paved apron having a porous pavement curb which functions as a coarse filter for said storm water flowing through said porous pavement curb.