Abstract: A leachate and pollutant drainage barrier system is formed by excavating a narrow slit or slot in the earth in the presence of a reversable slurry mud which changes from a highly viscous character after a predetermined period of time (approximately 5-7 days) needed to maintain the trench open to permit the laying of a drainage pipe at the bottom of the trench and the filling of the trench with a pervious fill, such as gravel, etc. After the fill has been installed, lateral support for the earth walls is provided by the pervious fill material and the slurry reverts to a liquid having a substantially lower viscosity which may be drained via the drain pipe in the bottom of the trench. In a preferred embodiment the slurry is a biodegradable polymer. In addition, a plastic film or layer can be installed in the trench.

Abstract: High density polyethylene sheets are sealed at their lateral edges to form a sheath or envelope for sandwiching a drain mesh. A plurality of spaced apart bore holes is formed along the line of the cut-off and drain barrier and a coupling member is positioned, one in each bore hole, respectively, each coupling member having at least one locking keyway slot formed in a side thereof. These coupling members have stainless steel keyway protectors or cement stops so that cementious material cast in the bore holes so as to stabilize the coupling members do not fill the keyways. After the cementious material has set, the space between bore holes up to the keyway slots is excavated including the cementious material between the facing edges of the keyway material. Then the drain barrier with rigidifying perforated pipes secured in the ends thereof is inserted into the excavated slot with the perforated pipes being telescopically received in and retained by the keyway slots.

Abstract: High density polyethylene sheets are installed in panel forms to form an impervious barrier to fluid flow particularly corrosive contaminates and pollutants. A slit is excavated in the earth under a bentonite slurry to the required depth. A relatively thick, high density polyethylene sheet is placed in the trench and connected to two high density polyethylene pipes or channel members, the width of which, in the direction transverse to the direction of the wall, is the width of the trench. The panel length typically will be 15 to 30 feet. Once the high density polyethylene panel is installed, the slurry is displaced on both sides by a backfill material that can be a soil-bentonite, cement-bentonite or concrete. A secondary panel section intermediate two previously formed primary panels is made using a secondary panel of high density polyethylene similarly constructed but using smaller diameter pipe or channel members than the primary panel pipes.