Patent Abstract:
A catch basin erosion containment filter assembly. The filter assembly includes a rigid frame and a containment bag attached at its open end to the frame. The frame is adapted to be seated and/or held in the horizontal or vertical opening to a catch basin. The bag has one or more layers, preferably at least two layers. The outer layer is preferably a woven geotextile fabric and the inner layer is preferably a nonwoven geotextile fabric. A hydrocarbon absorbent layer, such as a nonwoven oileophilic fabric, may be located between the inner and outer layers for capturing spilled fuel and/or oil.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/176,347, filed Jan. 14, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to a catch basin erosion containment filter assembly. 
     Water runoff from construction sites may find its way into the catch basin of a storm water sewer system. Such water may be contaminated with mud and debris generated by construction or other activities, and may also be contaminated with oil or fuel. 
     It is highly desirable that such contaminants be prevented from entering the sewer system. 
     It is known to place bags filled with bark and chips in front of the catch basin to capture such contaminants. 
     It has also been suggested to place a filter material on top of or beneath the grate covering the catch basin. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to provide a filter assembly that can be inserted into the catch basin at the entrance thereof to capture sedimentary contaminants entering with the water runoff. 
     It is a further object to provide a filter structure that can also capture hydrocarbon contaminants such as fuel and/or oil entering with the water runoff. 
     The filter assembly of this invention is comprised of a frame and a containment bag attached to the frame at its open end. Although the containment bag can be formed of a single layer of material, it is preferred that the containment bag be a laminate having at least two layers, the outer layer having a higher porosity and higher strength than the inner layer. 
     The outer layer is preferably a woven geotextile. The inner layer is preferably a nonwoven geotextile. 
     The laminate of the filter structure may have a fuel/oil absorbent intermediate layer. The intermediate layer is preferably a melt blown polyolefin such as polypropylene. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view, partially cut away, of a shallow version of the containment filter assembly of this invention; 
     FIG. 2 is a perspective view of the shallow version of the containment filter assembly of this invention; 
     FIG. 3 is a side view, partially cut away, of a deep version of the containment filter assembly of this invention; 
     FIG. 4 is an end view, in cross section, of the deep version of the containment filter assembly of this invention shown in its operable position inside a catch basin having a horizontal entrance grate; 
     FIG. 5 is an end view, in cross section, of the deep version of the containment filter assembly of this invention shown in its operable position inside a roadway storm sewer catch basin having a vertical entrance; 
     FIG. 6 is a perspective view of a containment bag having a central overflow pipe; 
     FIG. 7 is a top view of the containment bag of FIG. 6; 
     FIG. 8 is a side view, partially cut away, of the containment bag of FIG. 6; and 
     FIG. 9 is a partial cross-sectional view of the containment bag layered construction. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     A shallow version of the containment filter assembly  10  of this invention is shown in FIGS. 1 and 2. Containment filter assembly  10  has a rectangular frame  12  comprised of four upside down L-shaped frame members  13 ,  14 ,  15 , and  16 , each of said upside down L-shaped frame members Shaving an upper horizontal leg and a vertical downwardly extending leg, as shown. Frame members  13 - 16  are attached together at their junctures by welding or other attachment means to form a rectangular configuration. 
     Attached to rectangular frame  12  is a containment bag  20  comprised of an outer layer  22  and an inner layer  24 . The bag  20  can be formed from layers  22  and  24  by any conventional bag making method. 
     The outer layer  22  and inner layer  24  can be laminated together prior to bag assembly (the phrase “laminated” including merely laying one layer on top of the other) or, alternatively, separate bags could be formed from each of outer layer  22  and inner layer  24  and containment bag  20  formed by placing the bag formed of the inner layer  24  inside the bag formed of the outer layer  22 . In the embodiment illustrated in FIGS. 1 and 2, outer layer  22  and inner layer  24  are sewn together at their bottom juncture  26 . 
     Containment bag  20  is attached to frame  12  by abutting the upper edges of bag  20  against the outer walls of the vertical legs of L-shaped frame members  13 - 16 , as shown. Metal strips are placed against the outer upper edges of bag  20  opposite the outer surfaces of vertical legs of L-shaped frame members  13 - 16  (only metal strips  34 ,  35  and  36  being shown), and all of the metal strips (including metal strips  34 - 36  and the metal strip adjacent frame member  13 , not shown) fastened to the outer walls of the vertical legs of L-shaped frame members  13 - 16  by a plurality of suitable fastening means  18 , such as rivets or screws, passing through metal strips  3336 , through the upper edges of bag  20 , and through the vertical legs of L-shaped frame members  13 - 16 , as shown. 
     Outer layer  22  is preferably formed of a porous, woven plastic commonly referred to as a woven “geotextile”. Outer layer  22  is porous enough to allow water to flow freely therethrough but not larger solids. One such suitable material for outer layer  22  is Amoco Fabrics and Fibers Style 2002 geotextile manufactured by Amoco Fabrics and Fibers Company. This material has a permeativity of 0.05 sec when measured in accordance with ASTM Test Method D-4491. 
     The inner layer  24  is formed of a porous, nonwoven plastic material having a smaller pore size than outer layer  22 . This material also lets water flow through but not “finer” solids, i.e., solids small enough to have passed through layer  22 . Suitable materials for inner layer  24  include those commonly referred to as nonwoven geotextiles. One such suitable material for inner layer  24  is CEF Style 4545 geotextile manufactured by Amoco Fabrics and Fibers Company. This material has a permeativity of 2.1 sec when measured in accordance with ASTM Test Method D-4491. 
     If it is desired to have a containment filter structure that is capable of absorbing contaminants containing hydrocarbons such as waste fuel and/or oil, a hydrocarbon absorbing layer  23  (see FIG. 9) can be inserted between outer layer  22  and inner layer  24  of bag  10 . A suitable material for such a hydrocarbon absorbing layer  23  is a hydrophobic (oileophilic) nonwoven, such as a meltblown polypropylene sold by Complete Environmental Products, Inc. under the trademark CEP-R144. Since waste fuel and oil are lighter than water, the hydrocarbon absorbent layer need not extend all the way to the bottom of bag  10 . 
     The shallow containment filter assembly  10  described above may be used for sites where a large amount of contamination is not expected, such as a temporary construction site. For sites where a larger amount of contamination could be generated, a deeper containment filter assembly  110  having a containment bag  120  would be used. Such a bag  120  is shown in FIGS. 3 and 4 where the reference numerals refer to the same parts as identified in FIGS. 1 and 2 except that one hundred is added thereto. Where a hydrocarbon absorbing layer (not shown) is added between outer layer  122  and inner layer  124 , it preferably extends from the top of the bag down to within about one foot of the bottom of the catch basin. 
     The cross sectional dimensions of containment filter assemblies  10 ,  110  depend on the type of catch basin with which it is to be used since catch basins come in different sizes. 
     One added feature of the deep containment filter reassembly  110  is the provision of an overflow spout or pocket  138  located in the upper side of deep containment bag  120 . Overflow spout  138  communicates the interior of bag  120  with the exterior thereof, and allows water to flow out of the bag and into the sewer system in the event the lower part of the bag  110  becomes clogged and the water level rises to the level of overflow spout  138 . Such a spout may also be included in containment bag  20  of the embodiment of the invention described relative to FIGS. 1 and 2. 
     In FIG. 4 deep containment bag  110  is shown in its operable position inside a catch basin  40  having a horizontal entrance grate  42 . As can be seen, frame  112  is of such a size that the horizontal leg portions of frame members  112 - 116  (only frame members  113  and  115  being shown in FIG. 4) are seated on the lip  44  of catch basin  40  that seats grate  42 . Grate  42  is removed while containment bag  110  is being inserted into catch basin  40 , and replaced so that it is resting on the outer surfaces of the horizontal leg portions of frame members  113 - 116 , thereby securing containment filter assembly  110  in place. 
     In FIG. 5 a deep containment bag  120  is shown in its operable position inside a catch basin  50  adjacent a roadway  51 . Catch basin  50  has a vertical entrance  52  located in the roadway curbing. Frame  112 ′ is of such a size that it can be seated inside entrance  52 , as shown. Frame  112 ′ can be secured in place by any suitable fastening means. 
     Gasket material, such as roam rubber strips with adhesive backing, can be attached to either the underside or the upperside of the horizontal leg of frame members  113 - 116 . The gasket material would be placed on the underside where containment bag  110  is to be used with a catch basin having a horizontal grate (as illustrated in FIG.  4 ). The gasket material would be placed on the upperside where containment bag  110  is to be used with a roadside catch basin with a vertical entrance (as illustrated in FIG.  5 ). 
     FIGS. 6-8 illustrate a containment filter assembly  210  having a central overflow pipe  250 . Reference numbers to parts similar to those described relative to the embodiment described relative to FIGS. 1 and 2 have the same reference number but increased by 200. The rectangular frame  212  is reinforced by cross bracing members  260  and  262  which are attached (such as by welding) to.the corners of frame  212  at the junctures of frame members  213 - 216 . 
     Tubular overflow pipe  250  is centrally positioned within filter assembly  210 . Overflow pipe  250  may be held in place solely by its attachment to bag  220 , as discussed below. In addition, its open upper end may be attached to cross bracing members  260  and  262  by suitable fastening means, such as welding. Bag  220  has a hole cut into the center of its bottom and the bottom fabric surrounding the hole is gathered up around the mid-portion of overflow pipe  250  and attached thereto by clamp  252 , as best seen in FIGS. 6 and 8. Overflow pipe  250  communicates the interior of bag  220  with the exterior thereof. If bag  220  becomes clogged, water rising to the top thereof can escape through central overflow pipe  250  into the sewer system. 
     Frame  12  of the shallow version illustrated in FIGS. 1 and 2 and frame  112  of the deep version illustrated in FIGS. 3-5 can be reinforced with cross bracing in the same manner as illustrated relative to cross bracing members  260  and  262  of frame  212  of the central overflow version illustrated in FIGS. 6-8. Similarly, an overflow pipe similar to overflow pipe  250  may be used with the embodiments of the invention described in FIGS. 1 and 2 and in FIGS. 3-5. 
     Although frames  12 ,  112  and  212  have been described as being rectangular in order to be coextensive with, and seated on or against, the lips of catch basins having rectangular shaped entrances, such as those described in FIGS. 4 and 5, it is clear that for catch basins having a circular entrance shape, or other non-rectangular entrance shape, the shape and size of the frames of the various embodiments of the containment filter assembly of the present invention can be adapted to such a non-rectangular shape and size so that the frame can be seated on or against the lips of such catch basins. 
     It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments of this invention without departing from the underlying principles thereof. The scope of the present invention should, therefore, be determined only by the following claims.

Technology Classification (CPC): 4