A method a process involving the application of a labile organic substrate, with
supplied sulfate as needed, to a soil and ground water supply for the express purpose
of stimulating sulfate reduction to facilitate the formation of mineral iron sulfides
or other reduced reactive minerals, abiotically treats soil contaminants, including
chlorinated solvents, and hexavalent chromium, with an iron monosulfide microbial
geochemical treatment zone. Other iron sulfide compounds, or generally FexSy,
may also comprise the treatment zone in addition to iron monosulfide. The process
also includes, in some cases, the supplementation of sulfate to ground water where
insufficient natural supply exists, wherein a solution of organic and dissolved
reactive sulfate introduced to the soil and ground water, the introduction of sulfate
tailored to the individual site conditions to meet contaminant mass constraints.
