Exfiltration apparatus

Abstract

An exfiltration apparatus for removing contaminants from a fluid includes a housing, a filter portion positioned within the housing, and a particulate collecting member. The housing defines a fluid flow path extending from a fluid inlet disposed on a first side of the housing to a fluid outlet disposed on a second side of the housing. The particulate collecting member is disposed within the housing between the fluid inlet and the filter portion. The particulate collecting member includes a recessed particulate collecting portion proximate the filter portion and a raised apertured portion proximate the fluid inlet. Fluid flowing along the fluid flow path passes through the particulate collecting member and through the filter portion before exiting through the fluid outlet.

1 - 20 . (canceled) 
     
     
         21 . An exfiltration apparatus for removing contaminants from surface runoff water, the apparatus comprising:
 a housing defining a downward fluid flow path extending from a fluid inlet disposed on a top side of the housing to a fluid outlet disposed on a bottom side of the housing;   a filter portion positioned within the housing;   a particulate collecting plate disposed within the housing in a horizontal orientation between the fluid inlet and the filter portion, the particulate collecting plate including a recessed particulate collecting lower portion adjacent to the filter portion and a raised upper portion adjacent to the fluid inlet and defining a plurality of apertures, and   wherein the housing comprises a first portion defining the fluid inlet and a second portion defining the fluid outlet, the first housing portion being removable from the second housing portion to access the filter portion; and   wherein surface runoff water flowing along the downward fluid flow path passes through the particulate collecting plate and through the filter portion before exiting through the fluid outlet.   
     
     
         22 . The apparatus of  claim 21 , further comprising a second particulate collecting plate detached from and positioned below the first particulate collecting plate in a stacked relationship. 
     
     
         23 . The apparatus of  claim 22 , wherein the second particulate collecting plate includes a plurality of apertures that are smaller in diameter than the plurality of apertures of the first particulate collecting plate. 
     
     
         24 . The apparatus of  claim 21 , wherein the housing further comprises a second filter portion separate from the first filter portion and disposed between the first filter portion and the fluid outlet. 
     
     
         25 . The apparatus of  claim 21 , wherein the first portion of the housing comprises an outer grate received in and removable from a recessed border of the second housing portion for access to the particulate collecting plate. 
     
     
         26 . The apparatus of  claim 21 , wherein the filter portion is retained in the second housing portion. 
     
     
         27 . The apparatus of  claim 21 , wherein the filter portion comprises a porous concrete layer affixed within the housing. 
     
     
         28 . The apparatus of  claim 27 , wherein the porous concrete layer directly supports the particulate collecting plate. 
     
     
         29 . The apparatus of  claim 21 , wherein the plurality of apertures of the raised upper portion of the particulate collecting plate are disposed in a topmost surface facing the fluid inlet. 
     
     
         30 . The apparatus of  claim 21 , wherein the raised upper portion of the particulate collecting plate includes a plurality of convex portions defining a plurality of generally horizontal topmost surfaces, with the plurality of apertures being disposed in each of the plurality of generally horizontal topmost surfaces. 
     
     
         31 . The apparatus of  claim 21 , wherein the recessed lower portion of the particulate collecting plate includes a plurality of generally horizontal bottommost surfaces that are directly supported by the filter portion. 
     
     
         32 . The apparatus of  claim 21 , wherein the recesses lower portion of the particulate collecting plate is non-apertured. 
     
     
         33 . The apparatus of  claim 32 , wherein the recessed non-apertured lower portion of the particulate collecting plate defines a lower half of the particulate collecting plate. 
     
     
         34 . The apparatus of  claim 32 , wherein the recessed non-apertured lower portion of the particulate collecting plate defines a lower 90% of the particulate collecting plate. 
     
     
         35 . The apparatus of  claim 21 , wherein the particulate collecting plate is egg carton shaped. 
     
     
         36 . The apparatus of  claim 21 , wherein each of the plurality of apertures directly faces each of the fluid inlet and the filter portion. 
     
     
         37 . A method for removing contaminants from surface runoff water from an upper surface of a ground substrate, the method comprising:
 installing an exfiltration apparatus in the ground substrate, the exfiltration apparatus comprising:
 a housing defining a downward fluid flow path extending from an upper fluid inlet disposed in an upper portion of the housing to a lower fluid outlet disposed in a lower portion of the housing, the fluid inlet being exposed to receive surface runoff water from the upper surface of the ground substrate, the fluid outlet being connected with a drainage system; and 
 a filter portion positioned within the housing; 
   with the upper portion of the housing removed from the lower portion of the housing, inserting a particulate collecting plate within the housing in a horizontal orientation above the filter portion, such that a recessed particulate collecting lower portion of the particulate collecting plate is adjacent to the filter portion;   assembling the upper portion of the housing with the lower portion of the housing, such that a raised upper portion of the particulate collecting plate defining a plurality of apertures is adjacent to the fluid inlet, and   allowing surface runoff water entering the fluid inlet to flow along the downward fluid flow path, passing through the particulate collecting plate and through the filter portion before exiting through the fluid outlet, wherein contaminants carried by the surface runoff water are collected in the recessed particulate collecting lower portion of the particulate collecting plate.   
     
     
         38 . The method of  claim 37 , wherein the recessed particulate collecting lower portion of the particulate collecting plate is non-apertured, such that a portion of the surface runoff water entering the fluid inlet is retained in the recessed particulate collecting lower portion of the particulate collecting plate. 
     
     
         39 . The method of  claim 37 , further comprising removing the upper portion of the housing from the lower portion of the housing, withdrawing the particulate collecting plate from the housing, and cleaning collected contaminants from the recessed particulate collecting lower portion of the particulate collecting plate. 
     
     
         40 . The method of  claim 37 , wherein inserting the particulate collecting plate within the housing in a horizontal orientation above the filter portion comprises placing the particulate collecting plate directly on the filter portion.