Abstract:
A curb style drain filter kit has a length of flexible filter material of film or mesh with interstices sized to separate small particles from run-off water. The material is wrapped around a conduit which lays in the gutter and fits in a storm sewer inlet. The filter material extends outwardly from the conduit and covers the storm drain grate. An anchor is attached to the outer edge of the material to keep the material flat and covering the grate.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to site preparation of construction projects and, more particularly, to devices to prevent soil and other water pollutants from entering the storm water drainage system.  
       BACKGROUND OF THE INVENTION  
       [0002]     Once a construction site has been graded or denuded of vegetative cover, one of the major pollutant transport mechanisms is water run-off resulting from rainfall or ground water from other sources. Such run-off often contains soil or other water pollutants found on construction sites. The National Pollutant Discharge Elimination System (NPDES, a derivative of the 1978 Federal Clean Water Act) requires developers and builders to prevent the transport of water pollutants from all construction sites sized one acre and larger. NPDES infractions may incur fines upwards of $10,000 per day per violation.  
         [0003]     Numerous Best Management Practices (BMPs) are commonly employed to prevent storm water transport of pollutants. BMPs may take the form of procedural management practices, or a BMP may take the form of a physical barrier or device. An effective storm water pollution prevention program most often utilizes a redundant series of BMPs positioned inside the boundary of the construction site. Some BMPs may serve to slow water velocity thus allowing suspended solids to settle. Other BMPs may filter water pollutants from the water stream. Logically, one strategic location for installing pollution prevention BMP devices is at storm sewer inlets.  
         [0004]     Typically, water supply, sewer, and storm drainage systems are installed at the beginning of the construction cycle along with curbs and gutters. Also, new construction is sometimes accomplished in established neighborhoods where the storm drainage system is already in place. It is not uncommon for large, planned communities to have hundreds of active storm sewer inlets that, under NPDES regulations, need to be monitored or maintained on a weekly basis. For this reason it is imperative that storm water inlet protection devices are economically priced, as well as easily installed and quickly maintained.  
         [0005]     U.S. Pat. No. 5,632,888; U.S. Pat. No. 5,725,782; and U.S. Pat. No. 6,010,622 to Chinn, et. al. disclose a filter for a storm drainage inlet to separate water run-off from debris. The filter devices include a porous envelop into which the storm sewer grate is inserted. The storm grate envelop is joined with an upright cylindrical “roll” of filter material filled with impermeable or relatively impermeable material. The upright roll is intended to block water entry into the upright portion of the curb-style storm sewer inlet.  
         [0006]     However, experience shows that, in high volume storms, the porous envelop (with two porous layers through which water must pass) drains too slowly, and/or is very likely to become clogged with soil particulate matter. Moreover, the envelop nature of these devices renders them useful for only one size storm grate, and very time consuming to install.  
         [0007]     U.S. Pat. No. 5,954,952 to Strawser, Sr. discloses a storm water catch basin filter assembly which fixes to the catch basin inlet frame. The device consists of more than 50 separate parts requiring multi-stepped assembly/disassembly for installation and/or maintenance. Owing to time and cost, the device would be impractical for use on large scale construction sites.  
         [0008]     U.S. Pat. No. 6,709,579 to Singleton, et. al. discloses a stand alone, cylindrical storm water filter device intended for use with vertical curb inlets. The device includes an elongated body with weighted anchors at the ends. The elongated body contains a filter medium that may enclose a support member; once positioned the device is held in place only by gravity. Since the device lacks a means for physical anchoring, it therefore may be moved about during high volume storm water flows. Also, the device lacks a means for preventing sediments from passing underneath the elongated body and into the storm sewer.  
         [0009]     U.S. Pat. No. 5,843,306; U.S. Pat. No. 6,004,457; and U.S. Pat. No. 6,261,445 to Singleton disclose a domed silt guard to fit over a drop inlet of the storm sewer system. The device has a filter material which drapes over a pre-formed, rigid frame. This device is intended for off-road use because the domed nature of the filter does not lend itself to street traffic.  
         [0010]     U.S. Pat. No. 5,372,714 and U.S. Pat. No. 5,575,925 to Logue, Jr.; and U.S. Pat. No. 6,884,343 to Harris disclose a basket style storm filter designed to hang down inside storm sewer catch basins. When installed, the devices are supported by walls of the catch basin or by the storm sewer grate. These devices are more suited to non-construction site applications, such as intercepting leaves and other light debris carried by storm water flow during the Autumn season. However, on construction sites, experience shows that the basket style storm water filter accumulates large loads of water saturated sediment making the device heavy and, therefore, difficult to remove for cleaning. Also, under heavy sediment loads the basket style filter tends to separate at seams and/or joints. Such separations result in large holes or gaps in the filter material rendering it useless as a construction site storm water filter device. U.S. Pat. No. 5,958,226 to Fleischmann discloses another basket style storm water filter. This device is comprised of many components, making it prohibitively time consuming to install and service on large construction sites.  
         [0011]     Commercial products similar to the patented devices mentioned above may be found at a website entitled newpic.com. These devices, however, are intended as blocking mechanisms during HAZMAT spill response incidents rather than as storm water filters.  
         [0012]     Thus, what is lacking in the art is a curb style drain filter kit that: fulfills the primary objective of separating suspended solids from storm water drainage, is economical and easy to use; can be sized at the job site to meet particular drain requirements, and also, by virtue of its design and material components, allows storm water to enter curb inlets during high volume rain events.  
       SUMMARY OF THE INVENTION  
       [0013]     Disclosed is a curb-style inlet drain filter kit comprising a length of flexible filter material of film or mesh with interstices sized to separate small particles from run-off water. The material is wrapped around a perforated, plastic flexible conduit which lays in the gutter so as to cover the entire length of the curb-style storm sewer inlet, but only partially covering the height of the inlet opening. During maintenance work a rigid rod is inserted inside the perforated, plastic flex-pipe. The porous material extends outward from the conduit (away from the curb) covering the horizontal storm drain opening. The outer edge of the porous fabric is constructed with a sleeve designed to accept a rigid rod. With the rods inserted, the fabric is supported on both the curb side and the street side preventing it from falling into the catch basin. With the porous fabric positioned over the storm sewer opening, the inlet grate is then placed atop the fabric and seated in the inlet frame anchoring the porous fabric and, as such, keeping the fabric from falling into the catch basin even under the weight of storm water and/or accumulated sediments. With the storm grate in place, and while the filter fabric is in service, the rigid rods are removed to eliminate any potential impediments or dangers to construction traffic. Before servicing the filter fabric one rigid rod is inserted back into the outer sleeve and the second rod into the flexible plastic pipe. Then, after the anchoring storm grate is removed, the entire assembly (assumed to be laden with accumulated sediments and/or storm water) can be lifted from the storm inlet for cleaning or replacement. In periods of high storm water volume, the porous plastic pipe and filter material create a “dam” which slows the storm water movement, thus allowing larger suspended solids to settle. If water volume is sufficient to continue rising in the gutter, the excess storm water will spill over the top of the pipe/fabric “dam” into the curb inlet leaving the larger suspended solids behind in the gutter or on the filter fabric under the inlet grate.  
         [0014]     The filter material and plastic pipe are relatively inexpensive and quickly tailored to different sized storm sewer inlets. The rigid rods are assumed to be excess or scrap construction materials.  
         [0015]     Accordingly, it is a primary objective of the instant invention to provide an effective curb-style filter kit consisting of a quantity of filter material, a conduit, and rigid rods (for servicing) for installing a plurality of storm sewer filters on different sized storm sewer inlets.  
         [0016]     It is a further objective of the instant invention to provide a pervious filter material that is durable, but easily tailored in the field to fit varying sized storm inlets. In particular, the filter material can be pre-sewn, and made into a long length roll, e.g. 200 feet. The material is then unrolled, and cut to fit the size of the inlet opening to be protected. Similarly, perforated plastic pipe is purchased in rolls, e.g. 250 feet, and can be cut to length. Rigid rods are generally available on construction sites as excess or scrap concrete reinforcement material.  
         [0017]     It is yet another objective of the instant invention to provide a perforated tubular conduit which is easily sized to span the mouths of different sized storm sewer inlets.  
         [0018]     It is still a further objective of the invention to provide two anchor sleeves in the filter material through which rigid rods can be inserted during maintenance activities to prevent the soil/debris laden material from falling into the catch basin when the anchoring storm sewer grate is removed to clean or replace the filter fabric.  
         [0019]     Another objective is to employ the perforated conduit as additional surface area for filtering of water passing into the drain, while also using the height of the perforated conduit as a “dam” to slow the movement of storm water such that suspended solids will settle, while also allowing an “escape” route for water over the top of the “dam” during high volume storm events.  
         [0020]     Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.  
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0021]      FIG. 1  is a top plan view of the filter material of this invention;  
         [0022]      FIG. 2  is a perspective of the filter material with an open seam of this invention;  
         [0023]      FIG. 3  is a perspective of the curb-style filter kit of this invention;  
         [0024]      FIG. 4  is a pictorial of a drain;  
         [0025]      FIG. 5  is a pictorial of the filter kit placed over an open drain with anchor rods in position;  
         [0026]      FIG. 6  is a pictorial of the filter kit beneath a drain grate;  
         [0027]      FIG. 7  is a pictorial of the filter kit with anchor rods removed when in service;  
         [0028]      FIG. 8  is a pictorial of the filter kit with anchor rods re-inserted for maintenance; and  
         [0029]      FIG. 9  is a pictorial of the filter kit with the drain grate removed to clean the soil laden filter fabric.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0030]     The curb-style filter kit  10  is shown in  FIG. 3 . The kit is composed of a length of filter material  11  which may be a single ply or multiple plies, as shown in  FIG. 1 . The material may be a woven or non-woven web or a fenestrated film of natural or synthetic composition that is pervious to water but acts as a sieve to prevent the passage of small particles carried by the water. The material has interstices ranging from pin hole to one-quarter inch size and above. The material has adequate strength to support larger pieces of debris without rupture. The material may be supplied in rolls and cut to size at the individual drains.  
         [0031]     The multiple ply material has a seam  12  about the perimeter  13 ,  14  to join the plies together. The seam  12  can be sewn or secured by a line of adhesive or formed by heat and pressure.  
         [0032]     The multiple plies can have different characteristics, such as a heavier ply for strength and support joined to a finer ply with smaller interstices. As an alternative to the seam, the plies of material may be randomly stitched or otherwise joined throughout the superposed surfaces. This allows different sized smaller filters to be removed from a supply roll, not shown, and still maintain the integrity of the material.  
         [0033]     The drain filter may be pre-formed with an open hem  15  along one edge secured by seam  16 , as shown in  FIG. 2 , such as described above. The hem  15  is of a size to permit a conduit  18  to telescope through the opening  17 . The open hem allows quick and easy assembly of a conduit  18  and a piece of filter material having the open hem  16  when it is determined that a conduit is necessary. In some situations, the individual drain filters may be fabricated on the spot from a supply of several conduits and several rolls of filter material by cutting the material and conduit to size.  
         [0034]     In the embodiment shown in  FIG. 3 , a second open hem  19  is formed on the edge opposite the larger hem  16  and parallel thereto. The hem is formed by folding the edge over the material and securing it with a seam  20 . The second open hem is of such a size to accommodate an anchor  21 . As shown, the anchor  21  is a length of concrete reinforcing rod, usually referred to as re-bar, and readily available about construction sites. The anchor may be made of other elongated rods, bars, wooden stakes, chain, etc. The anchor  21  holds the free end of the filter material flat and in place to prevent the filter from uncovering the drain inlet or grate.  
         [0035]     Alternatively, the material is placed beneath the sewer grate eliminating the need for an anchor. In either event, the material is pre-made into a long length roll, e.g. 200 feet. The material is removed from the roll and cut to size the grate to be covered and either anchored or placed beneath the grate.  
         [0036]     The conduit  18  is, preferably, a lightweight corrugated plastic or rubberized tubing usually sized to partially fit within the drain inlet in the curb and serves to reinforce and stabilize the filter over the storm drain grate. The conduit further provides a pathway for flowing water in the gutter to by-pass the storm drain inlet, if it is clogged or draining slowly. In this manner, the run-off water is distributed within the storm drain system rather than becoming an uncontrolled flow. Preferably the conduit is constructed from a roll (e.g. 250 feet) of plastic perforated flexible pipe that can be cut to length as necessary.  
         [0037]     While the kit is shown with hems to secure the conduit and anchor, it is understood that the material, as shown in  FIG. 1 , could be rolled about the conduit and/or the anchor using them as a mandrel. The multiple wraps of filter material serve to hold the assembly in place.  
         [0038]     It is contemplated that a construction crew would visit storm drain inlets in the affected construction site. They would quickly cut the individual filters and conduits to approximate the size of the inlets and grates and install the kit.  
         [0039]     By way of illustration,  FIG. 4  is a pictorial of a drain  100  positioned along a curb  102  having a curb drain  104  and a grate  106  placed over a sewer opening.  FIG. 5  is a pictorial of the filter kit  10  placed over an open drain, not shown, with anchor rods  21  and  21 ′ in position. The filter material  11  is prevented from falling into the drain opening by use of the anchor rods  21  and  21 ′ which is placed within conduit  18 .  FIG. 6  depicts the filter kit  10  in position with the grate placed over the drain opening. The anchor rods  21  and  21 ′ can now be removed.  
         [0040]      FIG. 7  is a pictorial of the filter kit  10  with anchor rods removed allowing the filter material to catch soil that would have otherwise dropped into the sewer opening.  
         [0041]      FIG. 8  is a pictorial of the filter kit  10  with anchor rods  21  and  21 ′ re-inserted allowing for removal of the grate for cleaning maintenance.  
         [0042]      FIG. 9  is a pictorial of the filter kit  10  with the drain grate  106  removed allowing the soil  110  to removed from the filter fabric  11 . The soil stopped from entering the sewer opening  112 .  
         [0043]     It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.