Methods for remediating contaminated soil and groundwater using solid-phase organic materials

Systems and methods for treating contaminated soil and groundwater are contemplated. An aqueous slurry may be formulated from particles of solid-phase organic materials having particle sizes between 0.1 and 100 microns, which serve as organic electron donors which may biodegrade subsurface contaminants. The aqueous slurry is injected into an environmental subsurface at a pressure lower than the fracture pressure of the subsurface, which will result in a more uniform distribution of the slurry throughout the subsurface, rather than concentrated deposition of the solid-phase organic materials at points along the fractures, and will also tend to reduce disruption of the architecture of the soil matrix, increasing the utility of the remediated soil and preventing an increase in the rates of generation and efflux of methane and nitrous oxide from the soil to the atmosphere.