You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to pollution control devices for removing litter, sediments, salts and chemicals from water flowing through culverts and for preventing clogging of culverts. 
     2. Description of the Related Art 
     It has been the practice to place bales of hay or stones around the mouth of a culvert to slow down water flows and act as a barrier for litter and sediment. This method requires a substantial area around the mouth of the culvert and depending on the placement of the stones or hay, may not block all of the flow of water so as to not stop all litter or sediment from flowing past the barrier. Further, over time the barrier may shift, causing flows of water to carry litter and sediment past the barrier and into the culvert. Further, oils, salts or chemicals detrimental to the environment may be able to flow through the culvert and escape into the environment. 
     Another method of preventing litter and sediment from flowing from culverts has been to place a geotextile on poles stuck in the ground some distance in front of the culvert opening to block the water flow. However, water tends to flow around or under such barriers and is not an effective way to prevent litter and sediment from clogging the culvert or escaping into the environment. 
     During construction or at other times when debris, chemicals or oils may be likely to be washed through a culvert the temporary barriers may be used to prevent debris and silt from clogging the culvert or polluting the area around the culvert. Filters for oils, salts or chemicals may be temporarily needed on some culverts. 
     SUMMARY OF THE INVENTION 
     The culvert inlet protection device has barrier plates with apertures for allowing water to flow therethrough while preventing debris from passing. The barrier plates are placed across and attached to the mouth of the culvert thus taking up a small area at the end of the culvert and effectively blocking all the water passing through the culvert. A filter can be placed between the barrier plates to screen out sediment. The filter material can be selected to screen for salts, oils or other chemicals. The barrier plates can be quickly and easily attached to apertures in the culvert by bolts and just as easily removed when no longer needed. The barrier plates need not cover the entire opening of the culvert. The barrier plates preferably cover about ⅔ of the opening from the bottom toward the top of the culver mouth. In this manner, an overflow area is left at the top of the face of the culvert. The culvert opening may also have a plurality of bars across the opening so that animals or objects cannot enter the culvert. Such bars may be used as a safety precaution so that people or vehicles do not fall into the culvert opening. 
     OBJECTS OF THE INVENTION 
     It is an object of the invention to provide a temporary barrier for silts and debris from clogging culverts due to rain. 
     It is an object of the invention to provide a temporary barrier for oils, salts, or chemicals from entering culverts and polluting the environment downstream. 
     It is an object of the invention to quickly and easily install and remove the temporary barriers. 
     It is an object of the invention to provide a temporary barrier for silts and debris from clogging drain areas due to runoff. 
     It is an object of the invention to provide filters for removing pollutants from runoff water in a culvert. 
     It is an object of the invention to provide barriers for any size culvert. 
     Other objects, advantages and novel features of the present invention will become apparent from the following description of the preferred embodiments when considered in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a culvert with a sheet of barrier material and a filter across the front. 
         FIG. 2  is a perspective view of a culvert with a sheet of barrier material and a filter across the front of the culvert, stakes supporting the barrier material and bars covering the barrier material and the culvert opening. 
         FIG. 3  is a perspective view of a culvert with a sheet of barrier material and a filter across the front of the culvert and bars covering the culvert opening and barrier material. 
         FIG. 4  is a side view of the barrier plates attached to the culvert. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A culvert  100  with a typical shape and opening is shown in the figures. The culvert  100  shown has a flat bottom base  110  with upstanding walls  111  at each side of the base and a curved dome portion  112  covering the culvert. The mouth  115  is cut at an angle though the dome  112  and straight up and down at the walls  111  and has a flat bottom base  110 . The culvert may be made out of almost any material, such as concrete, plastic, metal or fiberglass. The culvert  100  may have any cross-sectional shape, but typically has an angled cut open top portion to the mouth. 
     In  FIG. 1  the culvert  100  has mouth  115  partly covered by a barrier comprising barrier plates  20 ,  120  which are made from a sheet of material having a plurality of apertures  22 . The barrier plates  20 ,  120  are riveted together by rivets  23  and have a filter material  40  sandwiched therebetween. The barrier plates  20 ,  120  are attached to the mouth  115  of the culvert  100  so that it covers on the order of ⅔ of the height of the mouth, thus leaving the top portion open for overflow of water during heavy rains. The barrier plates  20 ,  120  can be used to restrict the flow into the culvert  100 . There are several options for attaching the barrier plates  20 ,  120  to the culvert. The barrier plates  20 ,  120  may be directly attached to the culvert  100 . As shown in the figures the barrier plates  20 ,  120  have apertures  31  and  33  and T-bar  30  passes though a selected aperture  31  or  33  depending on the width of the culvert. The T-bar  30  is attached to the side of culvert  100  preferably using a bolt  32  in a culvert aperture used for lifting the culvert  100  or for some other purpose already preexisting in the culvert so that no drilling is required to install the T-bar  30 . The T-bar  30  has a slot  35  for adjusting the position of the T-bar along the side of the culvert  100  and to adjust the position of the barrier plates  20 ,  120  on the face of the culvert. The T-bar  30  has a head portion  37  which will not fit through aperture  31  or  33  and will pull the barrier plates  20 ,  120  back against the face of the culvert  100 . Ideally the barrier plate  120  runs along the front portion of the culvert  100  covering the front of the base  110 , and the front portion of the walls  111 . With the barrier plates  20 ,  120  in place, litter and debris larger than the apertures  22  will not be able to enter the culvert. 
     In one embodiment the barrier can be a single sheet of material with apertures. Alternatively the single sheet of material may have a filter attached to block the apertures. 
     In another embodiment, as shown, two barrier plates  20 ,  120  can be used to sandwich a filter material  40  therebetween. The filter material  40  can be changed by separating the barrier plate  20  from barrier plate  120  and removing the filter  40 , then cleaning the filter  40  or inserting a new filter before reattaching the barrier plate  20  to barrier plate  120 . In the embodiment shown the barrier plates  20  and  120  are riveted together by rivets  23  but any means for attaching the barrier plates may be used. The filters  40  can be made of any of a variety of materials and used for different purposes. For example geotextiles may be used as the filters. Filters of different weaves may block different grades of sand. Filters of different materials may be used to absorb oil, or different chemicals. Other filters may be used to block salts or other substances. 
     In order to reinforce the positioning of the barrier plates  20 ,  120  when assembled, rods  60  may be driven into the ground adjacent the culvert mouth  115  and engage the top of the barrier plate  20  such as through rod apertures  65 . 
     A seal  50  may be used to prevent water from escaping round the edges of the barrier plate  120 . Alternatively, caulking, gaskets or other means for preventing leaks may be used. 
     As shown bracket  30  may have an adjustment slot  35  for adjustably attaching the barrier plates  20 ,  120  to the culvert  100 . A trash guard  70  may be used to cover the mouth  115  of the culvert and barrier plates  20 ,  120  can rest against or be supported by the trash guard  70 . The trash guard  70  may be attached to the culvert  100  at the top of the dome portion  112  by bracket  80  having an adjustment slot  82  and a bolt  84 , which is used in an existing aperture of the culvert such that no holes need be drilled in the culvert  100  to attach the trash guard  70 . As shown the trash guard  70  fits onto a bracket  130  attached to culvert  100 . 
     In  FIG. 3  the trash guard  70  is placed over the top of the barrier plates  20 ,  120 . 
     The barrier material may be made out of plastic, metal or any other material. It is preferred to have the barrier material made out of a material, which can be cut to the size of the culvert mouth  115 . 
     Although the filter fabric  40  is shown sandwiched between two barrier plates  20 ,  120  it could be attached to the inside or the outside of one barrier plate on the face or back, and glued or otherwise affixed thereto covering the area between the apertures  22 . 
     The number and size of the apertures  22  in the barrier plates  20 ,  120  may be varied depending on the performance parameters of the culvert barrier and filter. The apertures  22  on the two barrier plates should overlap so that water may flow through the apertures. 
     Barrier plates  20 , as shown in  FIG. 4  may have troughs  28  to strengthen the plates. The troughs may also be used to surround reinforcing rods  29  placed between the barrier plates  20 ,  120  to increase the strength of the barrier in front of the culvert. Optionally the rods may be attached to the culvert at the ends of the barrier plates. 
     The barrier plates  20 ,  120  have a front portion  42  and a top portion  44  angled backward from the vertical front portion  42 . The edges  48  on the sides of the front portion  42  are vertical and the edges  46  of the top portion  44  are tapered to match the taper of the culvert mouth  115 . 
     In the field a contractor can select the size of the barrier plates  20 ,  120  to fit the size of the culvert mouth  115  and then attach the associated T-bar  30  through the appropriate aperture  31  or  33  in the barrier plates  20 ,  120 , and bolt the T-bar to the culvert  100 . The face of the barrier plates can then be moved adjacent to the face of the culvert by use of slots  35  to seal the barrier plate  120  to the face of the culvert with seal  50 . The head  37  of the T-bar will urge the barrier plate  20  back toward the culvert  100 . If rods  60  are needed to reinforce the barrier plates  20 ,  120  the rods  60  can be inserted and pounded into the ground at the face of the culvert mouth  115  and be attached to the barrier  20 ,  120  as required. When the culvert protector is no longer needed the barrier plates  20 ,  120  can be quickly and easily be removed.

Summary:
A temporary culvert barrier for placing across the mouth of a culvert for blocking litter and debris from entering or exiting the culvert and for filters to block silt or sand from clogging the culvert or the drain area. The filters may also be selected to absorb oils salts or other chemicals. The temporary barrier is easy to install and remove. The barrier plates and filters fit to the size of the culvert mouth and have adjustment slots for different width mouths. The culvert barrier may be used to prevent pollution at construction sites and be temporarily or permanently attached to culvert mouths. The filters may be changed or cleaned as required.