Saturated layer stormwater filtration system

Abstract

A saturated layer stormwater filtering system with down-flow layered multimedia filters is disclosed. The filtering system may include an upflow pretreatment chamber and a subsequent filtration chamber. It also includes a snorkel pipe as an adjustable head control or internal baffles. The system incorporates gravity powered partially saturated stormwater media filters to harness the potential energy of stormwater from downspouts and pumped flows from stormwater catchments to drive the polluted stormwater in a hydraulically controlled fashion by gravity through a series of filter media layers.

What is claimed: 
     
         1 . A stormwater filter system comprising:
 a chamber having an upper laterally positioned opening and a lower laterally positioned opening;   a layer of unsaturated filter media and saturated filter media within the chamber having an upper media surface;   a distribution header with an inlet opening aligned with the upper laterally positioned opening of the chamber, the inlet opening and the upper laterally positioned chamber opening being positioned above the upper surface of the layered unsaturated filter media and saturated filter media wherein the distribution outlet has a row of apertures operable to distribute a plurality of streams of stormwater over the upper surface of the layered saturated and unsaturated filter media; and   an outlet to in communication with the lower laterally positioned opening to discharge filtered stormwater.   
     
     
         2 . The filter system of  claim 1 , wherein the distribution header distributes the stormwater uniformly over the upper media surface. 
     
     
         3 . The filter system of  claim 1 , wherein the stormwater flows into the distribution header by gravity. 
     
     
         4 . The filter system of  claim 1 , further comprising: a debris screen positioned between the upper surface of the saturated and unsaturated filter media and the distribution header. 
     
     
         5 . The filter system of  claim 1 , further comprising a conduit coupled to the effluent pipe for maintaining a desired water level in the filtration vessel. 
     
     
         6 . The filter system of  claim 1 , wherein the chamber further comprises an emergency overflow outlet to provide operable to bypass the treatment media. 
     
     
         7 . The filter system of  claim 1 , wherein the at least one layer of the plurality of treatment media comprise unsaturated filter media and saturated media positioned beneath the unsaturated filter media. 
     
     
         8 . The filter system of  claim 1 , wherein the at least one layer of treatment media comprises one layer of an adsorptive media. 
     
     
         9 . A filter comprising:
 a vessel;   an inlet pipe entering the vessel through an inlet aperture;   a distribution header coupled to the inlet pipe with a plurality of apertures along its length wherein the plurality of apertures are operable to distribute a plurality of streams of stormwater;   a plurality of unsaturated filter media layers disposed below and in substantially parallel orientation to the distribution header in a vertical stack of layers;   a plurality of saturated filter media layers disposed below and in substantially parallel orientation to the plurality of unsaturated filter media layers in a vertical stack of layers; and   a bottom collection device disposed at the bottom of the vessel and below the plurality of saturated filter media layers extending through an aperture disposed in the vessel.   
     
     
         10 . The filter of  claim 9  further comprising a conduit assembly coupled to the bottom collection device where the bottom collection device extends through a lower vessel aperture. 
     
     
         11 . The filter of  claim 10  in which the conduit assembly includes an effluent sample port. 
     
     
         12 . The filter of  claim 9  in which the bottom collection device is a geotextile. 
     
     
         13 . The filter of  claim 9  in which the bottom collection device is a laminar flux device including a main distribution pipe and a plurality of perforated pipes coupled to the main distribution pipe. 
     
     
         14 . The filter of  claim 9  further comprising a debris screen disposed between the distribution header and a first layer of the plurality of unsaturated filter media layers. 
     
     
         15 . The filter of  claim 9  further comprising a perforated debris basket disposed between the distribution header and a first layer of the plurality of unsaturated filter media layers. 
     
     
         16 . The filter of  claim 9  further comprising a pretreatment vessel coupled to the inlet aperture and configured to receive stormwater through the inlet aperture.