Apparatus for in Situ Installation of Underground Containment Barriers Under Contaminated Lands

Book excerpt: An apparatus for constructing a subsurface containment barrier under a waste site disposed in soil is provided. The apparatus uses a reciprocating cutting and barrier forming device which forms a continuous elongate panel through the soil having a defined width. The reciprocating cutting and barrier forming device has multiple jets which eject a high pressure slurry mixture through an arcuate path or transversely across the panel being formed. A horizontal barrier can be formed by overlapping a plurality of such panels. The cutting device and barrier forming device is pulled through the soil by two substantially parallel pulling pipes which are directionally drilled under the waste site. A tractor or other pulling device is attached to the pulling pipes at one end and the cutting and barrier forming device is attached at the other. The tractor pulls the cutting and barrier forming device through the soil under the waste site without intersecting the waste site. A trailing pipe, attached to the cutting and barrier forming device, travels behind one of the pulling pipes. In the formation of an adjacent panel the trailing pipe becomes one of the next pulling pipes. This assures the formation of a continuous barrier.