| abstract |
The present invention relates to the method of 'in situ' collection and treatment of floating, sinking and dissolved contaminants in a soil environment which involves installation of wick-like drains in at least a portion of the waste site on the down-gradient side of in-ground water flow. The method more particularly involves the installation of pre-fabricated drainage strips in the form of wick drains which are installed vertically or inclinedly into the normal water table of the contaminated waste site. The depth of the wick drains which include porous and/or slotted channels are installed as deeply into the waste site as the normal in-ground water flow of the pollutants which affects its travel into the lower adjacent aquifer. In accordance with this invention, some of the wick drains which include porous or slotted pipes are employed for the injection of treating chemicals or reagents into the contaminated soil for its treatment in place prior to its normal flow into the aquifer. Some of the drains may be employed for injection of bacteria or microbes, nutrients and/or air into the waste site to obtain underground treatment of the pollutants in place over relatively short or longer periods of time depending upon the extent, chemical nature and concentration of pollutants. The wick drains are preferably comprised of highly-flexible lengthy plastic extrusion, most desirably comprised of polypropylene or similar plastic materials, having maximum water flow capacity along grooves formed longitudinally on both sides of the core. The drain has a woven filter-like jacket on its exterior which is comprised of a strong durable non-woven plastic geo-textile. The jacket serves as a filter to allow passage of ground water into the drain core, while preventing plugging of the filter form the adjacent oil or pluggage of the drain, the jacket serves as an outer skin to maintain cross-sectional shape and hydraulic capacity of the core channels. |