Apparatus and method for lining landfills, reservoirs, hazardous waste disposal sites and the like

Abstract

An improved method and a product for waterproofing soil utilizing a flexible plastic sheet for providing a water barrier and for providing a means of reflecting light sufficient to prevent damage to the sheet and the underlying soil from direct sunlight comprising a uniform density or multiple-density plastic sheet material which has been manufactured to a desired thickness to contain an upper surface cpable of reflecting light.

We claim: 
     
       1. A thermoplastic liner for outdoor fluid containment areas having a bottom and sidewalls comprising an inclined portion covering the sidewalls of said containment area and a planar portion covering the bottom of said containment area, raid thermoplastic liner having an upper surface and a lower surface in contact with said containment area, said upper surface being light reflective, said liner being adapted to sufficiently reflect incident radiation, reduce exposed liner temperature, and prevent adverse effects due to solar heating. 
     
     
       2. A thermoplastic liner as in claim 1, wherein said thermoplastic is constructed of a uniform density polyethylene having a density equal to or greater than 0.93 gm/cm 3 . 
     
     
       3. A thermoplastic liner as in claim 1, where in said upper surface of said liner contains an ultraviolet light stabilizer. 
     
     
       4. A thermoplastic liner as in claim 1, wherein said thermoplastic is constructed of a multi-density composite, comprising an upper layer of polyethylene forming said upper surface and having a density equal to or greater than 0.93 grams/cm 3 , a central core layer of polyethylene integrally bonded underneath said upper layer and having a density equal to or less than 0.92 grams/cm 3 , and a lower layer of polyethylene forming said lower surface and being integrally bonded underneath said central core layer. 
     
     
       5. A uniform density thermoplastic liner as in claim 2, wherein said upper surface of said liner encompasses about ten percent (10%) of the overall thickness of said plastic liner. 
     
     
       6. A multi-density composite thermoplastic liner of claim 4, wherein skid upper and lower layers have the same thickness and the thickness of said central core layer is st least three times the thickness of said upper layer. 
     
     
       7. A multi-density composite thermoplastic liner of claim 4, wherein said upper and lower layers are 10 mil in thickness and said central core layer is 40 mil in thickness. 
     
     
       8. A multi-density composite thermoplastic liner of claim 4, wherein said lower polyethylene layer is constructed from polyethylene having a density equal to or greater than 0.93 grams/cm 3 . 
     
     
       9. A multi-density composite thermoplastic liner of claim 4, wherein raid lower polyethylene layer is constructed from polyethylene having a density greater than 0.92 grams/cm 3 . 
     
     
       10. A multi-density composite thermoplastic liner of claim 4, wherein said lower polyethylene layer is light reflective. 
     
     
       11. A multi-density composite thermoplastic liner of claim 4, wherein said central core layer contains carbon black in sufficient concentration to help prevent ultraviolet light oxidative initiated degradation. 
     
     
       12. A thermoplastic liner for outdoor fluid containment areas having a bottom and sidewalls comprising an inclined portion covering the sidewalls of said containment area and a planar portion covering the bottom of said containment area, said thermoplastic liner having an upper surface and a lower surface in contact with said containment area, said upper surface being light reflective, said liner being adapted to sufficiently reflect incident radiation, reduce exposed liner temperature, and prevent adverse effects due to solar heating, wherein said upper surface of raid liner is pigmented with white pigment. 
     
     
       13. A thermoplastic liner of claim 12, wherein said white pigment is a titanium oxide. 
     
     
       14. A thermoplastic liner of claim 12, wherein said upper surface covers a layer that is darker than said upper surface, so that damage to said upper surface is more apparent. 
     
     
       15. A thermoplastic liner for outdoor fluid containment areas having a bottom and sidewalls comprising an inclined portion covering the sidewalls of said containment area and s planar portion covering the bottom of said containment area, said thermoplastic liner having an upper surface and a lower surface in contact with said containment area, said upper surface being fight reflective, said liner being adapted to sufficiently relect incident radiation, reduce exposed liner temperature, and prevent adverse effects due to solar heating, wherein said upper surface of said liner is pigmented with a pigment having a coefficient of reflection between 0.5 and 1.0. 
     
     
       16. A thermoplastic liner of claim 15, wherein said upper surface covers a hyer that is darker than said upper surface, so that damage to said upper surface is more apparent. 
     
     
       17. A thermoplastic liner for outdoer fluid containment areas having a bottom and sidewalls comprising an inclined portion covering the sidewalls of said containment area and a planar portion covering the bottom of said containment area, said thermoplastic liner having an upper surface and a lower surface in contact with said containment area, said upper surface being light reflective, said liner being adapted to sufficiently reflect incident radiation, reduce exposed liner temperature, and prevent adverse effects due to solar heating, wherein said upper surface of said liner contains an ultraviolet light stabilizer employing a hindered amine. 
     
     
       18. A thermoplastic liner for outdoor fluid containment areas having a bottom and sidewalls comprising an inclined portion covering the sidewalls of said containment area and s planar portion covering the bottom of said containment area, said thermoplastic liner having an upper surface and a lower surface in contact with said containment area, said upper surface being light reflective and toughened, said liner being adapted to sufficiently reflect incident radiation, reduce exposed liner temperature, and prevent adverse effects due to solar heating. 
     
     
       19. A thermoplastic liner as in claim 18, wherein said upper surface of said liner is toughened by creating turbulence in said upper surface during manufacture thereby leaving aspirates in said upper surface. 
     
     
       20. A thermoplastic liner for outdoor fluid containment areas having a bottom and sidewalls comprising an inclined portion covering the sidewalls of said containment area and a planar portion covering the bottom of said containment area, said thermoplastic liner having an upper surface and a lower surface in contact with said containment area, wherein said thermoplastic liner is constructed of a multi-density composite, comprising an upper layer of polyethylene forming said upper surface and having a density equal to or greater than 0.93 grams/cm 3 , a central core layer of polyethylene integrally bonded underneath said upper layer and having a density equal to or less than 0.92 grams/cm 3 , and a lower layer of polyethylene forming said lower surface and being integrally bonded underneath said central core layer. 
     
     
       21. A multi-density composite thermoplastic liner of claim 20, wherein said upper and lower byers have the same thickness and the thickness of said central core layer is at least three times the thickness of said upper layer. 
     
     
       22. A multi-density composite thermoplastic liner of claim 20, wherein said upper and lower layers are 10 mil in thickness and said central core layer is 40 mil in thickness. 
     
     
       23. A multi-density composite thermoplastic liner of claim 20, wherein said lower polyethylene layer is constructed from polyethylene having a density equal to or greater than 0.93 grams/cm 3 . 
     
     
       24. A multi-density composite thermoplastic liner of claim 20, wherein said lower polyethylene layer is constructed from polyethylene having a density greater than 0.92 grams/cm 3 . 
     
     
       25. A multi-density composite thermoplastic liner of claim 20, wherein said central core layer contains carbon black in sufficient concentration to help prevent ultraviolet light oxidative initiated degradation. 
     
     
       26. A method for waterproofing an area of soil comprising the steps of: (a) forming a flexible plastic sheet including a means for reflecting light sufficiently to prevent damage to said sheet and soil from solar heating and ultraviolet and incident radiation comprising a plastic sheet material containing an upper surface capable of reflecting light and an underside surface; (b) covering the soil to be waterproofed with a plurality of said flexible plastic sheets with said upper surface facing up;   (c) aligning said sheets in an abutting fashion to create a seam region between adjoining sheets; and   (d) permanently joining said abutting sheets to provide a continuous and uninterrupted barrier of plastic facing the area from which water is to be barred.   
     
     
       27. A method as in claim 26, wherein said plastic sheet is formed from a uniform density polyethylene having a density equal to or greater than 0.93 grams/cm 3 . 
     
     
       28. A method as in claim 26, wherein said upper surface of said liner is formed with a white pigment. 
     
     
       29. A method as in claim 26, wherein said upper surface of said liner is formed with a pigment having a coefficient of reflection between 0.5 and 1.0. 
     
     
       30. A method as in claim 26, wherein said upper surface of said liner is ultraviolet light stabilized. 
     
     
       31. A method as in claim 30, wherein said stabilizer is a Hindered Amine Light Stabilizer. 
     
     
       32. A method as in claim 26, wherein said upper surface of said liner is roughened. 
     
     
       33. A method as in claim 32, wherein said upper surface of said liner is toughened by creating turbulence in said upper surface during manufacture thereby leaving asperities in said upper surface. 
     
     
       34. A method as in claim 26, wherein said plastic sheet is formed from a multi-density composite, comprising an upper layer of polyethylene forming said upper surface and having a density equal to or greater than 0.93 grams/cm 3 , a central core layer of polyethylene integrally bonded underneath said upper layer and having a density equal to or less than 0.92 grams/cm 3 , and a lower layer of polyethylene forming said underside surface and being integrally bonded underneath said central core layer. 
     
     
       35. A method as in claim 27, wherein said upper surface of said liner encompssses about ten percent (10) of the overall thickness of said uniform density plastic liner. 
     
     
       36. A method as in claim 34, wherein said upper and lower layers are formed with the same thickness and the thickness of said central core layer is formed to be at least three times the thickness of said upper layer. 
     
     
       37. A method as in claim 34, wherein said upper and lower layers are formed to be 10 mil in thickness and said central core layer is formed to be 40 mil in thickhess. 
     
     
       38. A method as in claim 28, wherein said white pigment is a titanium oxide. 
     
     
       39. A method as in claim 34, wherein said lower polyethylene layer is constructed from polyethylene having a density equal to or greater than 0.93 grams/cm 3 . 
     
     
       40. A method as in claim 34, wherein said lower polyethylene layer is constructed from polythylene having a density equal to or greater than 0.92 grams/cm 3 . 
     
     
       41. A method as in claim 34, wherein said lower polyethylene layer is pigmented with a fight reflective material. 
     
     
       42. A method as in claim 34, wherein said central core layer is pigmented with carbon black in sufficient concentration to help prevent ultraviolet light oxidative initiated degradation. 
     
     
       43. A thermoplastic liner for outdoor fluid containment areas having a bottom and sidewalls comprising an inclined portion covering the sidewalls of said containment area and a planar portion covering the bottom of said containment area, said thermoplastic liner having an upper surface and a lower surface in contact with said containment area, said upper surface being light reflective, said liner being adapted to .[.sufficiently reflect incident radiation, reduce exposed liner temperature, and.]. prevent adverse effects due to solar heating, said upper surface having light reflective material mixed into thermoplastic liner material. 
     
     
       44. The liner of claim 43 wherein the upper surface is formed by coextruding a layer containing light reflective pigment onto another layer. 
     
     
       45. A method for waterproofing an area of soil comprising the steps of: (a) forming a flexible plastic sheet .[.including a means for reflecting light sufficiently to prevent damage to said sheet and soil from solar heating and ultraviolet and incident radiation.]. comprising a plastic sheet material containing an upper surface capable of reflecting light and an underside surface; (b) forming said upper surface by mixing reflective material into the plastic sheet to form a reflective layer; (c) covering the soil to be waterproofed with a plurality of said flexible plastic sheets with said upper surface facing up; (d) aligning said sheets in an abutting fashion to create a seam region between adjoining sheets; and (e) permanently joining said abutting sheets to provide a continuous and uninterrupted barrier of plastic facing the area from which water is to be barred.   
     
     
       46. The method of claim 45 wherein said forming steps include the step of coextruding a plastic layer containing light reflective material onto another plastic layer.