Patent Publication Number: US-2021171361-A1

Title: Methods, devices and systems for suspended solids removal

Description:
CROSS-REFERENCE 
     This application claims the benefit of U.S. Provisional Application No. 62/946,327, filed Dec. 10, 2019, entitled UNDERGROUND PASSIVE MEDIA FILTER which application is incorporated herein in its entirety by reference. 
    
    
     BACKGROUND 
     As the climate continues to change causing increased storm intensity, the impact of stormwater pollution continues to be an important environmental issue. Stormwater runoff has been identified as a leading cause of water quality impairment. Stormwater, whether from rain or snowmelt, picks-up and carries pollutants along its pathway into our waterways. The pollutants in stormwater can include: trash and floatables, hydrocarbons, oil and heavy metals from vehicles and emissions; nutrients such as nitrogen and phosphorus, pesticides and other chemicals; bacteria; and sediment. 
     A variety of solutions exist for stormwater pollution management. Stormwater pollution management practices are referred to as Best Management Practices (BMPs). BMPs can include source control, structural controls and treatment controls. Stormwater treatment systems, such as a gravity separator, can be used to remove dirt, oil and floatable material from stormwater. See, for example, U.S. Pat. No. 7,892,425 issued Feb. 22, 2011 for Stormwater Plug Flow Separation System. There are, however, limits to the amount and nature of materials that can easily be removed from stormwater using current solutions. 
     What is needed are passive and semi-passive devices, systems and methods for treatment or pre-treatment of stormwater which can provide efficient stormwater filtration. Additionally, what is needed are devices, systems and methods for treatment or pre-treatment of stormwater which is suitable for sites with high particulates (TSS) loading such as industrial facilities, multi-family residential and commercial facilities. 
     SUMMARY 
     Disclosed are devices, systems and methods for treatment or pre-treatment of stormwater which can provide efficient stormwater filtration. Also disclosed are devices, systems and methods for treatment or pre-treatment of stormwater which is suitable for sites with high particulates (total suspended solid (TSS)), oil and floatables loading. Devices include a passive media filter that can operate by gravity with no power required and no mechanical or moving parts. Media can be formulated for high-flow and high sediment loading. 
     An aspect of the disclosure is directed to filtration systems. Filtration systems comprise a flow container wherein the flow container comprises: a fluid inlet aperture; an inlet chamber in fluid communication with the fluid inlet aperture; a first media filtration chamber in fluid communication with the inlet chamber having a first media; a flow structure positioned between the inlet chamber and the first media filtration chamber wherein the flow structure is configured to direct fluid passing from the inlet chamber to the first media filtration chamber in a downward direction; a second media filtration chamber in fluid communication with the first media filtration chamber having a second media wherein the second media filtration chamber has an upward treatment flow direction; a wide flow transfer window positioned between the first media filtration chamber and the second media filtration chamber wherein the wide flow transfer window allows continuous filtration between the first media filtration chamber and the second media filtration chamber; an outlet chamber in fluid communication with the second media filtration chamber; and an outlet aperture in fluid communication with the outlet chamber. In some configurations, the inlet chamber is further in fluid communication with the outlet chamber via an internal high-flow bypass. In still other configurations, the first media and the second media are the same media material. Additionally, a position of the flow structure between the inlet chamber and the first media filtration chamber is positioned above an upper level of the media layer. A position of the wide flow transfer window between the first media filtration chamber and the second media filtration chamber is positioned below an upper level of the media layer in the first media filtration chamber. In other configurations, the wide-flow transfer window is positioned along a lower surface of the chambers. The filtration system can further be positioned in series with a second treatment device, such as a pre-treatment system or a secondary treatment system. The systems are configurable to have a pollutant removal efficiency of at least one of: TSS 50-70%; Aluminum 30-60%; Copper 40-70%; Iron 40-60%; and Zinc 10-30%. Additionally, the systems are configurable to have a treatment rate of from 160 gallons-per-minute to 1,400 gallons-per-minute. 
     Other aspects of the disclosure are directed to methods of treating fluid comprising the steps of: providing a source fluid for treatment to an inlet chamber via at least one of a lateral inlet aperture and an upper aperture; transferring the fluid received into the inlet chamber to a first media filtration chamber via a flow structure positioned between the inlet chamber and the first media filtration chamber wherein the flow structure is configured to direct fluid passing from the inlet chamber to the first media filtration chamber in a downward direction; passing the fluid received into the first media filtration chamber through a first media layer; passing the fluid via a wide flow transfer window through a second media layer in a second media filtration chamber; receiving the fluid onto a surface of the second media layer; and passing fluid into an outlet chamber in fluid communication with the second media filtration chamber; and delivering fluid from the outlet chamber via an outlet aperture. The fluid received into the inlet chamber can be gravity fed. Additionally, the methods can include the step of passing the fluid from the inlet chamber to the outlet chamber when a fluid level exceeds a holding volume in the inlet chamber. Additionally, the first media layer and the second media layer comprise the same media material. Alternatively, the first media layer and the second media layer comprise the different media material. The methods can further comprising the step of removing pollutants from the fluid through one or more of mechanical filtration, media surface adhesion, and coalescing of oily substances. Fluid can also be through the media using a high surface area and low fluid velocity. Additionally, the filtration system can have a pollutant removal efficiency of at least one of: TSS 50-70%; Aluminum 30-60%; Copper 40-70%; Iron 40-60%; and Zinc 10-30% and/or configured to treat 160 to 1400 gallons per minute. The methods are suitable to process fluids that contain solid materials and particulate materials. 
     INCORPORATION BY REFERENCE 
     All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. 
     U.S. Pat. No. 248,574 A dated 1881 Oct. 25 12:00 AM by Burkhardt; 
     U.S. Pat. No. 329,791 A dated Nov. 3, 1885 by Westinghouse; 
     U.S. Pat. No. 962,606 A dated Jun. 28, 1910 by Wiest; 
     U.S. Pat. No. 1,332,882 A dated Mar. 9, 1920 by Boze; 
     U.S. Pat. No. 1,422,674 A dated Jul. 11, 1922 by Cook; 
     U.S. Pat. No. 1,902,171 A dated Mar. 21, 1933 by Kopp; 
     U.S. Pat. No. 3,228,531 A dated Jan. 11, 1966 by Proudman; 
     U.S. Pat. No. 3,554,377 A dated Jan. 12, 1971 by Miller; 
     U.S. Pat. No. 4,208,291 A dated Jun. 17, 1980 by Ochoa; 
     U.S. Pat. No. 4,717,476 A dated Jan. 5, 1988 by Scott; 
     U.S. Pat. No. 4,750,999 A dated Jun. 14, 1988 by Roberts et al.; 
     U.S. Pat. No. 5,679,256 A dated Oct. 21, 1997 by Rose; 
     U.S. Pat. No. 5,820,762 A dated Oct. 13, 1998 by Bamer et al.; 
     U.S. Pat. No. 5,958,239 A dated Sep. 28, 1999 by Sing; 
     U.S. Pat. No. 5,993,672 A dated Nov. 30, 1999 by Manz; 
     U.S. Pat. No. 6,077,448 A dated Jun. 20, 2000 by Tran Quoc Nam et al.; 
     U.S. Pat. No. 6,123,858 A dated Sep. 26, 2000 by Manz; 
     U.S. Pat. No. 6,248,233 B1 dated Jun. 19, 2001 by Priggemeyer et al.; 
     U.S. Pat. No. 6,632,501 B2 dated Oct. 14, 2003 by Brownstein et al.; 
     U.S. Pat. No. 6,908,540 B2 dated Jun. 21, 2005 by Kholodenko; 
     U.S. Pat. No. 6,908,549 B2 dated Jun. 21, 2005 by Middleton et al.; 
     U.S. Pat. No. 7,005,060 a dated Feb. 28, 2006 by Pitt et al.; 
     U.S. Pat. No. 7,022,243 B2 dated Apr. 4, 2006 by Bryant; 
     U.S. Pat. No. 7,025,887 B1 dated Apr. 11, 2006 by Kirts et al.; 
     U.S. Pat. No. 7,300,590 B2 dated Nov. 27, 2007 by Weir et al.; 
     U.S. Pat. No. 7,459,090 B1 dated Dec. 2, 2008 by Collings; 
     U.S. Pat. No. 7,805,890 B2 dated Oct. 5, 2010 by Esmond et al.; 
     U.S. Pat. No. 7,892,425 B2 dated Feb. 22, 2011 by Generes et al.; 
     U.S. Pat. No. 7,892,425 B2 dated Feb. 22, 2011 by Generes et al.; 
     U.S. Pat. No. 8,002,974 B2 dated Aug. 23, 2011 by Noling et al.; 
     U.S. Pat. No. 8,002,984 B1 dated Aug. 23, 2011 by Wanielista et al.; 
     U.S. Pat. No. 8,012,346 B2 dated Sep. 6, 2011 by John Peters et al.; 
     U.S. Pat. No. 8,894,866 B1 dated Nov. 25, 2014 by Belasco; 
     U.S. Pat. No. 9,315,406 B2 dated Apr. 19, 2016 by Strano et al.; 
     US 2002/0096466 A1 dated Jul. 25, 2002 by Perry; 
     US 2008/0197083 A1 dated Aug. 21, 2008 by Raveneau Champion et al.; 
     US 2008/0217227 A1 dated Sep. 11, 2008 by Pank; 
     US 2008/0251448 A1 dated Oct. 16, 2008 by Kent; 
     US 2009/0101555 A1 dated Apr. 23, 2009 by Scarpine et al.; 
     US 2010/0326904 A1 dated Dec. 30, 2010 by Lord; 
     US 2013/0292317 A1 dated Nov. 7, 2013 by Shaw et al.; 
     US 2014/0021137 A1 dated Jan. 23, 2014 by Smiddy, et al.; 
     US 2017/0326478 A1 dated Nov. 16, 2017 by Noling et al.; 
     US 2017/0326478 A1 dated Nov. 16, 2017 by Noling et al.; and 
     WO 2017/205087 A1 dated Nov. 30, 2017 by NOLING et al. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which: 
         FIG. 1  is a perspective view of a device configurable for treatment or pre-treatment of stormwater with the lid removed and the sides of the device partially cut-away to expose the interior; 
         FIG. 2A  is a top view of a device configurable for treatment or pre-treatment of stormwater with the lid removed;  FIG. 2B  is a top view of a lid for a device according to the disclosure; 
         FIG. 3  is a top plan view of a device configurable for treatment or pre-treatment of stormwater; 
         FIGS. 4A-B  are a side sectional view of a device along the lines  4 - 4  of  FIG. 2A  with and without media configurable for treatment or pre-treatment of stormwater; 
         FIG. 5  is a side sectional view through  5 - 5  in  FIG. 2A ; 
         FIG. 6  is a side sectional view through  6 - 6  in  FIG. 2A ; and 
         FIG. 7  is a flow diagram of a method for treatment or pre-treatment of stormwater using a disclosed device. 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed are coarse media filter devices and systems configurable to remove dirt, debris, oil and floatables by media filtration. The disclosed devices, systems and methods can be implemented as a stand-alone treatment device or as a pretreatment device in a treatment train configuration or as part of a system of unit operations. When installed as a pretreatment device, the devices prolong the maintenance interval and improve the function of any downstream treatment systems (e.g. sand or media filtration). The devices and systems are beneficial for sites with a high concentration of fine or non-settling solids in the stormwater. The systems are configurable to capture fine solids, particulate metals, neutral buoyancy debris, and floatable debris while also capturing hydrocarbons at a high flowrate. 
     I. Devices 
       FIG. 1  is a perspective view of a device  100  configurable for treatment or pre-treatment of stormwater with a container  110  and a lid  180  removed. The container  110  has a bottom  111  and four exterior container side walls  112 ,  114 ,  116 ,  118 .  FIG. 1  illustrates two of the exterior container side walls,  112 ,  114  of the device  100  partially cut-away to expose the interior of the device  100  with interior portions of the device  100  shown in dashed lines to allow a perspective view into the various chambers. The overall shape of the device  100  can be a rectangular prism (as shown) or any other shape suitable to achieve the treatment results, e.g. cylindrical. The height H of the device  100  can vary to match the installation site conditions but is typically from 5 feet to 10 feet in height. The device  100  is configurable for installation below ground. 
     In use, water does not pass over the walls between the input chamber and the down-flow treatment chamber, the down-flow treatment chamber and the up-flow treatment chamber, or the up-flow treatment chamber and the output chamber. As discussed in more detail below the water passes from the input chamber to the down-flow treatment chamber via the aperture and shroud between input chamber  130  and down-flow treatment chamber  140 , via the aperture formed by the wide transfer window  154  between down-flow treatment chamber  140  to and up-flow treatment chamber  150 , and through the downturned elbow  152  between up-flow treatment chamber  150  and outflow chamber  160 . Water can also pass over the top of the interior wall  132  between the input chamber  130  and the output chamber  160 . 
       FIG. 2A  is a plan view of a device  100  with four interior chambers: an inlet chamber  130 , a down-flow treatment chamber  140 , an up-flow treatment chamber  150 , and an outlet chamber  160 . Each chamber can be configured to be adjacent to two other chambers in the device  100  as shown. 
     In the illustrated embodiment, a first interior wall  132  is provided that is positioned between the inlet chamber  130  and the outlet chamber  160 ; a second interior wall  134  is provided that is positioned between the inlet chamber  130  and the down-flow treatment chamber  140 ; a third interior wall  136  is provided that is positioned between the down-flow treatment chamber  140  and the up-flow treatment chamber  150 ; and a fourth interior wall  138  is positioned between the up-flow chamber  150  and the outlet chamber  160 . As will be appreciated by those skilled in the art, the interior walls can be separate walls and/or integrally formed walls without departing from the scope of the disclosure. For example, second interior wall  134  and fourth interior wall  138  can be formed from a single piece of material such as a single slab of concrete, plastic or steel. 
     Each chamber in the illustrated configuration has two chamber walls that correspond to a portion of two exterior walls of the device  100 ; and two chamber walls that are shared (i.e., a first interior wall shared with a first chamber and a second interior wall shared with a second chamber). A first exterior container side wall  112  borders the down-flow treatment chamber  140  and the up-flow treatment chamber  150 . A second exterior container side wall  114  borders the down-flow treatment chamber  140  and the inlet chamber  130 . A third exterior side wall  116  borders the inlet chamber  130  and the outlet chamber  160 . A fourth exterior wall  118  borders the up-flow treatment chamber  150  and the outlet chamber  160 . 
     As will be appreciated by those skilled in the art, the actual location of the inlet chamber  130  and the outlet chamber  160  in any configuration is a function of the direction of stormwater flow for a particular installation and not limited to the position illustrated in the figures. The inlet chamber  130  has an inlet aperture and the outlet chamber has an outlet aperture. As illustrated, the inlet aperture is shown with an inlet pipe  120  and the outlet aperture is shown with an outlet pipe  122 . Additionally, the inlet pipe  120  can be positioned on any exterior surface corresponding to the inlet chamber  130  and the outlet pipe  122  can be positioned on any exterior surface corresponding to the outlet chamber  160  without departing from the scope of the disclosure. Thus, for example, the inlet pipe  120  and the outlet pipe  122  could be positioned on the exterior wall  116  corresponding to the inlet chamber  130  and the outlet chamber  160 . 
     The device  100  has an inlet pipe  120  on the second exterior container side wall  114 . The inlet pipe  120  is, for example, a 4″ cast-in inlet coupling which is watertight around the coupling edges. The inlet pipe  120  is positionable between 50-70% of the height from the bottom of the device  100 . Inlet chamber  130  receives stormwater runoff through inlet aperture via the illustrated inlet pipe  120  and/or an inlet grate  182  in the lid  180 . 
     A first interior wall  132  is positioned between the inlet chamber  130  and the outlet chamber  160 . The first interior wall  132  is a weir wall. The first interior wall  132  has a variable height that is determined based on bypass flow rates and calculated head-loss through the system. As illustrated, the height is approximately 83% of the total exterior height of the device  100 . The first interior wall  132  can function as an internal high-flow bypass. 
     A second interior wall  134  is positioned between the inlet chamber  130  and the down-flow treatment chamber  140 . The second interior wall  134  can be any height above the water surface and all the way to the bottom surface of the lid  180 . As illustrated, the second interior wall  134  is shown with a height that is approximately 83% of the total exterior height of the device  100 . The down-flow treatment chamber  140  is configured to receive stormwater from the inlet chamber  130 . 
     The stormwater to be treated is received into the inlet chamber  130  and then directed into the second chamber or down-flow treatment chamber  140 . An aperture  143  is provided in the second interior wall  134 . The aperture  145  has a shroud  146  was positioned above the upper surface of the aperture  145 . The shroud  146  can be formed from stainless steel, plastic or other material, and positioned to direct the flow of water through the aperture  143  from the inlet chamber  130  to the down-flow treatment chamber  140  in a downward gradient. The use of the shroud  146  to achieve a downward gradient sweeps debris under the shroud  146  but prevents captured floating debris from escaping during a high-flow bypass event. In the down-flow treatment chamber  140 , coarse debris and trash are removed from the stormwater by mechanical filtration and floatation. Flow capacity and treatment performance are maximized by the large irregular pore spaces of the coarse media, the low water velocity through the media, and the relatively high surface area available for solids adhesion. 
     As will be appreciated by those skilled in the art, a high-flow bypass event occurs during extreme events when the amount of water attempting to pass through the system exceeds a threshold potentially causing re-suspension of sediment. In order to minimize the negative impact of an extreme event on the operation of the system, the first interior wall  132  allows excess water to be shunted directly to the output container to avoid re-suspension of sediment thereby increasing the overall effectiveness of the pollutant removal process. 
     The down-flow treatment chamber  140  includes coarse filtration media  144 . The down-flow treatment chamber  140  is characterized by a filter media depth and a water depth. As will be appreciated from the figures, the down-flow treatment chamber  140  has a relatively shallow filter bed depth. The wide shallow bed of the down-flow treatment chamber  140  allows a large flow rate of stormwater to pass through the filter with little pressure or head-loss. 
     Water from the down-flow treatment chamber  140  passes to the up-flow treatment chamber  150 . The up-flow treatment chamber  150  has a filter media depth and a water depth. A wide transfer window  154  is formed by an aperture in the third interior wall  136  having a wide transfer window width and height. The wide transfer window  154  is positioned between the down-flow chamber  140  and the up-flow chamber  150  and provides for fluid communication between the two chambers. The wide transfer window  154  allows for a well-distributed flow throughout the filter media and reduces the amount of hydraulic pressure required to force the water through the filter. The wide transfer window  154  can be formed by a baffle wall blockout or opening created in the wall. The wide transfer window  154  has a width that is about &gt;75% of the width of the third interior wall  136  and a height that is about 30-40% of the height from the floor to the invert of the outlet orifice elbow  152 . The wide transfer window  154  is positioned along a portion of the third interior wall  136  below an upper surface of filter material placed into the down-flow treatment chamber  140  and up-flow treatment chamber  150 . In some configurations, the wide transfer window  154  is positioned at or near the bottom surface of the third interior wall  136 . The devices can be formed from any suitable material including, but not limited to, concrete, steel, fiberglass, or plastic. The up-flow treatment chamber  150  is a second coarse media filtration chamber that allows for additional pollutant removal through mechanical filtration, media surface adhesion and coalescing of oily substances that allows floatable oil droplets and particulates to agglomerate and become trapped or float to the surface. The outlet orifice elbow  152  controls the flowrate through the treatment chambers and retains floatables and hydrocarbons within the treatment chamber (i.e., does not allow floatables to pass to the outlet chamber  160 ). 
     As will be appreciated by those skilled in the art, one or more layers of filter material can be used for the filter media  144  and the height of the media in the down-flow chamber  140  and the up-flow chamber  150  can be the same or substantially the same. 
     Table 1 provides exemplar dimensions for various components of the devices. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Exemplar Part Sizes 
               
            
           
           
               
               
            
               
                   
                 Size Range 
               
               
                 Component 
                 (Feet) 
               
               
                   
               
            
           
           
               
               
               
            
               
                 Device Length 
                 9 
                 28 
               
               
                 Device Width 
                 7 
                 11 
               
               
                 Device Height 
                 5 
                 15 
               
               
                 Inlet Chamber: Down-Flow Chamber wall (134) height 
                 5 
                 10 
               
               
                 Inlet Chamber: Outlet Chamber wall (132) height 
                 3.5 
                 9 
               
               
                 Inlet Window (145) width 
                 2 
                 5 
               
               
                 Inlet Window (145) height 
                 0.5 
                 1 
               
               
                 Shroud (146) width 
                 2 
                 5 
               
               
                 Down-Flow Chamber: Up-Flow Chamber wall (136) 
                 5 
                 10 
               
               
                 Down-flow Chamber Depth 
                 5 
                 10 
               
               
                 Down-flow Chamber Filter Media Depth 
                 2 
                 4 
               
               
                 Down-flow Chamber water depth 
                 3 
                 5 
               
               
                 Wide transfer window (154) width 
                 2 
                 21 
               
               
                 Wide transfer window (154) height 
                 1 
                 2 
               
               
                 Up-flow chamber: outlet chamber (138) wall height 
                 5 
                 10 
               
               
                   
               
            
           
         
       
     
     As will be appreciated by those skilled in the art, the overall size of the devices is configurable to match the site conditions. For example, the depth can be a variable depth as needed based on the site. 
     The lid  180  has a plurality of apertures. One or more of the apertures can function as hatch openings for accessing an interior of the device  100 . Each hatch opening can have a cover or door. A first aperture can be configured to receive a grate inlet  182  positioned on the lid  180  in a location over the inlet chamber  130  when the lid  180  is positioned over the container  110 . A second aperture  184  can be provided and positioned on the lid  180  in a location over the down-flow chamber  140  when the lid  180  is positioned over the container  110 . A third aperture  186  can be provided and positioned on the lid  180  in a location over the up-flow chamber  150  when the lid  180  is positioned over the container  110 . A fourth aperture  188  can be provided and positioned on the lid  180  in a location over the outlet chamber  160  when the lid  180  is positioned over the container  110 . The apertures are illustrated as circular, but as will be appreciated by those skilled in the art, the apertures do not need to have the same shape or size. For example, one or more of the apertures and corresponding covers can be square. Each of the apertures can be configured to receive a grate or cover. Typically, the grate is associated with the aperture over the inlet chamber  130 , and the covers are associated with the apertures over the remaining chambers. Additionally a riser can be provided to increase the bury depth of container  110  and to increase the distance from ground surface to 180? 
       FIG. 2  is a top view of a device  100  configurable for treatment or pre-treatment of stormwater with the lid removed. 
     The inlet chamber  130  and the outlet chamber  160  have an interior length that is, for example, about 20% the overall exterior length L of the device  100  and an interior width of about 44% the overall exterior width W of the device  100 . The down-flow treatment chamber  140  and the up-flow treatment chamber  150  has an interior length that is about 76% of the overall exterior length L of the device  100  and an interior width of about 44% of the overall exterior width W of the device  100 . Other ratios can be used without departing from the scope of the disclosure. 
     The length and the width of the outlet chamber  160  can be the same or substantially the same as the inlet chamber  130 . The length and the width of the up-flow treatment chamber  150  can be the same or substantially the same as the down-flow treatment chamber  140 . 
     As discussed above, inlet chamber  130  receives stormwater runoff through the inlet pipe  120  and/or an inlet grate  182  in the lid  180 . The water then passes from the inlet chamber  130  to the down-flow treatment chamber  140 . Some stormwater may pass from the inlet chamber  130  to the outlet chamber  160  by passing over the first interior wall  132  which is sized to act as an internal high-flow bypass between the inlet chamber  130  and the outlet chamber  160 , and around the down-flow treatment chamber  140  and up-flow treatment chamber  150 . For storm conditions that exceed the design treatment flow rate that passes through the down-flow treatment chamber  140  and up-flow treatment chamber  150 , the systems and devices are configurable to allow a portion of the stormwater to move directly from the inlet chamber  130  to the outlet chamber  160  by flowing over the first interior wall  132  which functions as a bypass weir wall by allowing water to pool behind the wall and flow over the top of the wall during the storm conditions that exceed design parameters. 
     Coarse debris and trash are removed from the stormwater by mechanical filtration and floatation in the down-flow treatment chamber  140 . Flow capacity and treatment performance are maximized by the large pore spaces of the coarse media, low water velocity through the media pore spaces, and the relatively high surface area available for solids adhesion. Stormwater then passes to the up-flow treatment chamber  150  via the wide transfer window  154  which allows for a well-distributed flow throughout the filter media and reduces the amount of hydraulic pressure required to force the water through the filter. The well-distributed flow eliminates the occurrence of high-velocity zones that would scour the filter media. 
     The up-flow treatment chamber  150  is the second coarse media filtration chamber that allows for additional pollutant removal through mechanical filtration, media surface adhesion, and coalescing of oily substances that allows fine floatable oil and hydrocarbon droplets and particulates to agglomerate and become trapped or float to the surface. The adsorbed oily particulates act as a fixed film biological reactor to remove and degrade organics. The outlet orifice elbow  152  in this chamber serves to control the flow rate through the treatment chambers and retain floatables within the device  100 . 
       FIG. 3  is a top plan view of a device  100  configurable for treatment or pre-treatment of stormwater. From this view, the flow of the stormwater from the inlet chamber  130  to the downflow chamber  140  to the upflow chamber  150  and finally the outlet chamber  160  via the outlet orifice elbow  152 . An outlet pipe  122  is provided that allows the treated stormwater to pass out of the outlet chamber  160 . The water exiting the outlet chamber  160  is discharged by gravity through the outlet pipe  160 . 
     A submersible pump system  310  can be provided which facilitates pumping the pre-treated processed stormwater out of the outlet chamber  160  for additional treatment or reuse above-ground. The pump sits in the bottom of the outlet chamber  160  and lifts the pre-treated stormwater through a pressurized discharge pipe to a downstream use. 
       FIGS. 4A-B  are a side sectional views of a device  100  configurable for treatment or pre-treatment of stormwater. Two removable covers  410 ,  420  are depicted in  FIG. 4B . The covers  410 ,  420  can be sized to provide access to the interior of the device  100  during maintenance. A suitable size for the manhole aperture is 24″ with the covers  410 ,  420  sized to fit over the manhole apertures. As discussed above, other shapes and for the apertures (shown as, for example,  184 ,  186 ,  188  in  FIG. 2B ) and covers  420  (shown in  FIG. 4 ) and  530 ,  540  (shown in  FIG. 5 ), such as rectangular, can be used without departing from the scope of the disclosure. Risers (not shown) can also be provided to raise the access point to grade. Risers would have a two-dimensional shape corresponding to the aperture (e.g., round or rectangular). A key-way groove (not shown) can also be provided to help seal the two pieces of the device  100  where the two pieces come together. The outlet aperture  123  can be connected to, for example, an outlet pipe  122 . 
       FIG. 5  is a side sectional view of the device  100  through the outlet chamber  160  and the up-flow treatment chamber  150  through the lines  5 - 5  in  FIG. 2A . The media surface  510  is shown below the water surface  520 . 
       FIG. 6  is a side sectional view of the device  100  through the inlet chamber  130  and the outlet chamber  160  along the lines  6 - 6  in  FIG. 2A . 
     II. Methods 
       FIG. 7  is a flow diagram of a method for treatment or pre-treatment of stormwater using a disclosed device. The systems and devices are typically installed below ground and in-line with an existing storm drain to allow stormwater to be gravity fed into the systems and devices. 
     Stormwater is gravity fed through the inlet pipe  120  and/or the grate inlet  182  in the lid  180  into the inlet chamber  130  as shown at step  710 . Once the stormwater level reaches a target height within the inlet chamber  130  determined by the invert elevation of  152  plus the head-loss through chambers  140  and  150 , stormwater passes through the inlet window  145  in the interior wall between the inlet chamber  130  and the down-flow treatment chamber  140  at step  720 . The stormwater passes into the down-flow treatment chamber  140  on a downward gradient from the inlet chamber  130 . Stormwater then collects on the surface of the media in the down-flow treatment chamber  140 . As additional stormwater collects in the downward flow chamber  140 , water is forced into the media material until the stormwater reaches or substantially reaches the bottom of the down-flow treatment chamber  140 . Over time, the stormwater passes laterally from the down-flow treatment chamber  140  into the adjacent up-flow treatment chamber  150  via the wide-flow transfer window  154  located between the two treatment chambers. As stormwater passes into the up-flow treatment chamber  150  and the stormwater passes through the filter media in the up-flow treatment chamber  150  until it passes to the surface of the filter media in the up-flow treatment chamber  150 . From the upper filter media surface, the stormwater (now filtered through the media in the down-flow treatment chamber  140  and the media in the up-flow filter treatment chamber  150 ) collects until it passes into the outlet chamber  160 . From the outlet chamber  160 , the treated or pretreated stormwater passes via gravity through an outlet  170 . Once the treated stormwater exits the device it can be transferred to another treatment system for further processing or to a stormwater outfall or discharge location. Additionally, a pump system can be provided which is associated with the outlet chamber. The pump system can be used to facilitate pumping treated or pretreated stormwater from the device. 
     Flow in excess of treatment capacity can also flow over the internal wall  132  (the bypass weir) directly to the outlet chamber  725  before exiting the system via the outlet chamber  760 . 
     The devices are configurable to achieve the treatment rates outlined in Table 2. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 TREATMENT RATES 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Treatment Rate 
                 Footprint 
                 Sediment 
                 Oil/Floatable 
               
               
                   
                 (gpm) gallons 
                 (L × W) 
                 Capacity 
                 Storage 
               
               
                   
                 per minute 
                 in feet 
                 (cubic yards) 
                 (gallons) 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 160 
                 7 × 9 
                 0.5 
                 100 
               
               
                   
                 300 
                  7 × 13 
                 1.0 
                 180 
               
               
                   
                 480 
                  8 × 16 
                 2.1 
                 280 
               
               
                   
                 600 
                  9 × 17 
                 2.6 
                 360 
               
               
                   
                 760 
                 11 × 17 
                 4.2 
                 460 
               
               
                   
                 1400 
                 11 × 28 
                 7.5 
                 810 
               
               
                   
                   
               
            
           
         
       
     
     Polluted stormwater is directed to the two media chambers in series for removal of dirt, debris, oil and floatables, and other associated pollutants such as heavy metals, nutrients and organics. Treated stormwater flows to the outlet chamber for discharge. With the built-in internal high flow bypass, pollutants are trapped in the treatment chambers in below ground installations even during excessive runoff events or events exceeding the design capacity of the device. 
     Table 3 provides performance rates for removal efficiency of pollutants 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 POLLUTANT REMOVAL EFFICIENCY 
               
            
           
           
               
               
               
            
               
                   
                   
                 Removal 
               
               
                   
                 Pollutant 
                 Efficiency 
               
               
                   
                   
               
               
                   
                 Total suspended solids (TSS) 
                 50-70% 
               
               
                   
                 Aluminum 
                 30-60% 
               
               
                   
                 Copper 
                 40-70% 
               
               
                   
                 Iron 
                 40-60% 
               
               
                   
                 Zinc 
                 10-30% 
               
               
                   
                   
               
            
           
         
       
     
     Monitoring the operational condition of the devices and systems can be achieved by periodic sampling of the filtration media from either treatment chamber using a long-handled swing sampler. The solid to media ratio is evaluated to determine the condition of filter media and remaining pollutant removal capacity. As the ratio increases, the media is more occluded and is not filtering as efficiently. Once the ratio is increased beyond an optimal amount, the filter media can be changed. The media, sediment and water removed from the systems and devices are disposed of in accordance with applicable waste disposal regulations. 
     While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.