Abstract:
An environmental protection and detection system includes a vapor and gas impervious barrier extending beneath at least part of the area of an enclosure to prevent fluids leaked or spilled within the enclosure for flowing downwardly into the underlying soil and ground water and to prevent vapors and gases emanating from sources beneath the enclosure from percolating upwardly into the enclosure. Lengths of perforated pipe are positioned above the barrier and are connected to points outside the enclosure for use in detecting and removing contaminants leaked or spilled within the enclosure. Lengths of perforated pipe are positioned beneath the barrier and are vented to the atmosphere for preventing accumulations of fluids emanating from sources beneath the enclosure.

Description:
This application is a continuation of U.S. Ser. No. 09/480,124 filed Jan. 10, 2000 now U.S. Pat No. 6,543,189. 
    
    
     TECHNICAL FIELD 
     This invention relates generally to the protection of the subsurface under the floors of buildings and other enclosures from environmental contamination, and more particularly to a system for containing contaminants originating within the building and facilitating the detection and removal thereof and for venting contaminants emanating from sources beneath the building. 
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Buildings and similar enclosures require environmental protection for at least two reasons. First, leaks, spills, etc. occurring within the building can seep downwardly, eventually causing contamination of the underlying soil and ground water. Depending upon the magnitude and duration of the problem, either of these conditions can lead to the condemnation of the building or other enclosure. Second, gases and liquids emanating from sources located beneath the building can percolate upwardly leading to contamination of the building with odorous, poisonous, and/or flammable substances. 
     The present invention comprises an environmental protection and detection system which overcomes the foregoing and other problems which have long since characterized the prior art. In accordance with the broader aspects of the invention, a barrier layer is disposed beneath the floor of the building or other enclosure. The barrier extends continuously across the entire length and width of the enclosure or portions thereof. The barrier prevents leaks, spills, etc. originating within the building from seeping into the underlying soil and ground water. The barrier also prevents gases and liquids emanating from sources beneath the building from entering the building. 
     A layer of fill may be distributed over the top of the barrier and beneath the floor of the building. Above the barrier, there is disposed a plurality of perforated pipe sections each connected to an individual outlet member. The perforated pipe sections situated above the barrier are arranged in a predetermined pattern to facilitate the detection and removal of materials which had been leaked, spilled, etc. within the building and which have penetrated through the floor thereof. 
     Sections of perforated pipe are disposed beneath the barrier in a predetermined array. In this manner gases and liquids emanating from sources beneath the building are received within the perforated pipe sections. The perforated pipe sections are connected to vent risers which extend upwardly to discharge ports located above the top of the building. In this manner contaminants emanating from sources beneath the building are vented to the atmosphere and are prevented from entering the building. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete understanding of the invention may be had by reference to the following Detailed Description when taken in conjunction with the accompanying Drawings, wherein: 
     FIG. 1 is a vertical sectional view of a building equipped with the environmental protection and detection system of the present invention; 
     FIG. 2 is a view similar to FIG. 1 showing an alternative embodiment of the invention; 
     FIG. 3 is a sectional view taken generally along the line  3 — 3  in FIG. 1; 
     FIG. 4 is a partial plan view of the building of FIG. 1 further illustrating the environmental protection and detection system thereof; 
     FIG. 5 is an enlarged side view of one of the component parts of the environmental protection and detection system of FIG. 1; 
     FIG. 6 is a sectional view taken generally along the line  6 — 6  of FIG. 5; 
     FIG. 7 is an illustration of the installation of the component part of FIG. 5; 
     FIG. 8 is an enlarged top view of another component part of the environmental protection and detection system of FIG. 1; and 
     FIG. 9 is a sectional view taken generally along the line  9 — 9  of FIG.  8 . 
    
    
     DETAILED DESCRIPTION 
     Referring now to the Drawings, and particularly to FIG. 1 thereof, there is shown a building  10  incorporating an environmental protection and detection system  12  constructed in accordance with the present invention. The building  10  comprises a foundation  14 , walls  16  extending upwardly from the foundation  14 , a floor  18  extending between the walls  16 , and a roof  20  overlying the foundation  14 . It will be understood that the component parts of the building  10  as shown in FIG. 1, et seq. are illustrative only, and that the present invention is applicable to buildings constructed in accordance with a wide variety of building techniques now known or hereafter developed. Those skilled in the art will further appreciate and understand that the present invention is readily adapted for use in conjunction with enclosures other than buildings. 
     The environmental protection and detection system  12  of the present invention includes a barrier  26  extending beneath the floor  18  of the building  10 . The barrier  26  may extend across the entire length and width of the building  10  or selected portions thereof. The end portions  28  of the barrier  26  extend upwardly between the floor  18  and the walls  16  comprising the building  10  thereby forming a seal between the floor  18  and the walls  16 . 
     The barrier  26  is preferably formed from high density polyethylene (HDPE) having a thickness of at least 40 mils. As will be appreciated by those skilled in the art, other materials may be utilized in the practice of the invention for the construction of the barrier  26 . The only requirement is that the barrier  26  is effective to prevent leaks, spills, etc. originating within the building from seeping downwardly into the underlying soil and ground water and to prevent gases and liquids emanating from sources beneath the building from percolating upwardly into the interior of the building. 
     If it is necessary that a pipe or conduit penetrates the barrier  26  from the subsurface, a boot formed from the same material as the barrier is constructed around the vertical portion of the pipe or conduit allowing for an overlap of the barrier at point of penetration. The boot is welded or otherwise secured to the pipe or conduit and to the barrier  26  with no gaps. 
     In certain circumstances the dimensions of the building  10  may be larger than the dimensions of the sheets of the material which are used to form the barrier  26 . In such instances adjacent sheets of materials are joined in the manner illustrated in FIG.  3 . Sheets of material  30  and  32  are joined together by parallel welds  34  and  36  thereby forming a pocket  38  between the welds  34  and  36 . After the welds  34  and  36  are completed, the pocket  38  is filled with compressed air to test the welds  34  and  36  against leakage. Other joint constructions between adjacent sheets of barrier material can also be used. 
     Referring again to FIG. 1, the environmental protection and detection system  12  comprises a plurality of lengths of perforated or slotted pipe  44 . As is best shown in FIG. 4, the lengths of perforated pipe  44  are interconnected to form a grid  46  which underlies the entirety of the floor  18  of the building  10 . The lengths of perforated pipe  44  extend to vent risers  48  which extend upwardly through channels  50  formed in the wall  16  of the building  10  (FIG.  1 ). As will be appreciated by those skilled in the art, the vent risers  48  need not extend through channels, but can be suitably located in accordance with the requirements of particular applications of the invention. The upper end of each vent riser  48  extends through the roof  20  of the building to a vent  52  which is open to the atmosphere. Each vent  52  is provided with a rain cap  54 . 
     Referring to FIG. 2, there is shown an alternative method of securing the edge of the barrier  26 . The foundation  14  is provided with a continuous channel  56  formed from high density polyethylene (HDPE). The edge of barrier  26  is welded to the HDPE channel  56 . A boot  58  formed from the same material as the barrier  26  is formed around the intersection of the barrier  26  and the pipe  44  and is welded or otherwise secured to the barrier  26  and to the pipe  44  with no gaps. 
     The construction of the lengths of perforated pipe  44  is further illustrated in FIGS. 5 and 6. The perforated pipe  44  comprises a plastic material and includes spaced apart ribs  60 . Apertures  62  are formed in the perforated pipe  44  between the ribs  60 . The perforated pipe is of the type identified in the industry as corrugated HDPE (high density polyethylene), and is provided in rolls which are uncoiled as the perforated pipe  44  is installed. Other types of perforated pipe can also be used in the practice of the invention. 
     The installation of the perforated pipe  44  is further illustrated in FIG.  7 . The subsoil  66  underlying what will become the floor of the building  10  is scraped to provide a relatively smooth upper surface  68 . A trench  70  is formed in the undisturbed subsoil  66 . The trench  70  is lined with a fabric layer  72  to prevent the soil from contaminating the interior of the slotted pipe  44 . The fabric layer  72  is sufficiently permeable to allow gases and vapors to pass therethrough while at the same time being impermeable to solids, particularly soil. After the fabric layer  72  is installed, the trench  70  is filled with pea gravel or similar self compacting aggregate to a depth of approximately one half of the trench, The slotted pipe  44  is then installed on top of the aggregate. The remainder of the trench is then filled with pea gravel or similar aggregate, after which the fabric layer  72  is folded over the top of the aggregate. In this manner it is assured that the slotted pipe  44  will remain open to the entry of gases and vapors and will not become clogged with soil. 
     Referring to FIGS. 1,  2 , and  4 , the environmental protection and detection system  12  further includes a plurality of contamination detection and removal apparatus  80 . The contamination detection and removal apparatus  80  extends from boxes  82  located outside the walls  16  of the building  10  and accessible from the exterior surface. A boot  83  formed from the same material as the barrier  26  is secured around each apparatus  80  and overlaps the barrier  26 . The boot is secured by welding with no gaps. 
     The contamination detection and removal apparatus  80  define a matrix wherein the apparatus  80  are spaced at predetermined intervals based on the porosity of the subfloor material to facilitate monitoring of the entire area beneath the floor  18  of the building  10 , and it necessary, the removal of contaminants from particular locations beneath the floor  18 . 
     The construction of the contamination monitoring and removal apparatus  80  is further illustrated in FIGS. 8 and 9. Sections of slotted pipe  84  extend outwardly from a tee connector  86  to end caps  88 . As is shown in FIG. 9, the slotted pipe sections  84  comprise openings  90  connected by webs  92 . A solid pipe section  94  extends from the tee connector  86  to a fitting  96  adapted to connect the slotted pipe sections  84  to monitoring probes and/or a vacuum apparatus. 
     The procedure for installing the environmental protection and detection system  12  of the present invention will be best understood by reference to FIG.  1 . The subsoil  66  is first worked to provide a relatively flat, relatively smooth top surface  68 . The trench  70  is then formed in accordance with the desired pattern of the perforated pipes  44 . The perforated pipes  44  are then installed as illustrated in FIG.  7  and described hereandabove in conjunction therewith. 
     After the perforated pipes  44  have been installed, a first layer of fill  100  may be deposited over the subsoil  66  and is suitably compacted. If used, the fill material is selected so as to be entirely free of rocks and debris to assure that the barrier  26  will not be penetrated. At this point the walls  16  are constructed on top of the foundation  14  and the vent risers  48  are connected to the perforated pipes  44 . 
     Next after the installation process is the installation of the barrier  26 . If the sheets comprising the barrier  26  are not large enough to fill the entire area defined by the wall  16 , adjacent sheets are welded as illustrated in FIG.  2 . The contamination detection and removal apparatus  80  are next installed over the barrier  26  and are extended through apertures which have been formed in the wall  16 . If necessary, a second fill layer  102  may be installed over the barrier  26  and the. contamination detection and removal apparatus  80  and is suitably compacted. The floor  18  is then installed over the second fill layer  102  with the end portions  28  of the barrier  26  extending between the walls  16  and the floor  18  to form a seal there between. 
     In the operation of the environmental protection and detection system  12  of the present invention, fluids percolating upwardly from sources located beneath the building  10  are trapped by the barrier  26  and therefore cannot enter the building  10 . However, fluids percolating upwardly passed through the subsoil  66 , the fabric layer  72 , and the aggregate  74 , and thereupon enter the perforated pipe  44 . 
     The perforated pipe sections  44  are vented to the atmosphere through the vent risers  48  and the vents  52 . Therefore, changes in atmospheric pressure result in pressure changes within the perforated pipes  44 . This results in a pumping action which causes vapors and/or gases received within the perforated pipes  44  to be pumped upwardly through the vent risers  48  and vented to the atmosphere through the vents  52 . This result is highly advantageous in preventing accumulations of troublesome and potentially dangerous fluids beneath the barrier  26 . 
     Regardless of the construction of the floor  18  of the building  10 , fluids leaked or spilled within the building  10  may pass through the floor  18  thereof and into the fill layer  102  situated on top of the barrier  26 . In any such event the barrier  26  prevents such fluids from flowing further downwardly through the fill  100 , into the subsoil  66 , and eventually contaminating soil and ground water within the soil. 
     The contamination detection and removal apparatus  80  are utilized to monitor the content of the fill layer  102  and to effect removal of any contaminants therefrom in the event that fluids from the building  10  pass through the floor  18  thereof and into the fill layer  102 . In one application of the invention, environmental detection devices are connected to the solid pipes  94  and are used to withdraw air from the subfloor material. The withdrawn air carries traces of contaminants which are detected by the environmental detection devices. In another application of the invention, a vacuum pump is connected to the fitting  96  and is utilized to withdraw vapors and/or gases from the fill layer  102  through the perforated pipes  104 . The vapors and/or gases thus withdrawn from the fill layer  102  may be analyzed using various well known techniques and apparatus. 
     Assuming that the foregoing testing procedures reveal contamination within the fill layer  102 , additional testing may be performed in order to ascertain the exact region of the fill layer  102  in which the contamination has occurred. Thereafter, vacuum pumps may be connected to the fittings  96  of various contamination detection and removal apparatus  80  whereby the contaminant is withdrawn from beneath the floor  18  of the building  10  for appropriate disposal. If the viscosity of the contaminant prevents direct removal thereof, the apparatus  80  may be utilized to initially direct solvents into the fill layer  102 . After the solvent has dissolved the contaminant, vacuum pumps are connected to the fittings  96  of appropriate apparatus  80  to remove the solvent and the contaminant dissolved therein from the fill  102 . Another approach is the utilization of the apparatus  80  to discharge a contaminant neutralizing agent into the area of the fill layer  102  which is contaminated. 
     Although preferred embodiments of the invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it will be understood that the invention is not limited to the embodiments disclosed but is capable of numerous rearrangements, modifications, and substitutions of parts and elements without departing from the spirit of the invention.