Abstract: The system places traces of nutrients and other treatment substances in the ground, in the path of an on-coming plume of contaminated groundwater. Boreholes placed across the plume contain respective diffusion tubes, the tubes being of e.g LDPE, or dialysis tubing. The remediation substance is circulated (pumped) through the diffusion tubes periodically. The remediation substance diffuses through the LDPE into the water in the borehole, and thence into the plume and is carried into the aquifer.

Abstract: The present invention is directed to a method for purifying an underground water supply containing halogenated aliphatic compounds by in-situ biodegradation of said compounds, comprising injecting water into an aquifer zone, the injected water containing an electron donor capable of being utilized by an indigenous population of microorganisms contained in the groundwater supply as a primary growth substrate, and an electron acceptor for oxidation of the primary substrate, by separate addition of electron donor and electron acceptor temporally or spatially to stimulate growth of the microorganisms and to distribute them throughout the aquifer zone to cause in-situ degradation of the halogenated aliphatic compounds by metabolic activity of the microorganisms.