Bioremediation on working industrial sites using slurry injection

From Geoprobe - www.geoprobe.com

Using bioremediation to detoxify many pollutants has become a common practice. Quick response with a set surface biological treatment has proven very effective in shallow, soil surface spills in tanks farms, rail yards, etc where the contamination is within a few inches of the surface and the contaminant is often crude or fuels such as diesel. In the above case, a quick addition of fertilizer, microbes, and biosurfactant/surfactant blends can reduce TPH to background in anywhere from 21 - 120 days depending upon contamination extent and other environmental variable. Benefits from in-situ treatment include:

• Avoid risk & costs of transporting contaminated soil off site
• If on an industrial site, activity can continue without disruption
• Effective in cleaning soil and not adding waste to RCRA landfills
  
  

Last week when presented with a working industrial site having moderate crude oil contamination, I suggested in-situ treatment. The hydrocarbons have accumulated under concrete pads, several feet below the surface (where oxygen is present for aerobic treatment). While evaluating the site, I mentioned slurry injection - a technology developed in the late 1980s for in-situ treatment of soil and groundwater - maybe the best treatment alternative. In short, slurry injection is:

• High pressure injection into subsurface of a bioremediation "cocktail"
• Equipment and workers on-site only during injection events (Usually cleaned in 1 - 3 injection events)
• Works up to 40 feet depth and effective in most soils
• Workers inject a blend of oxygen release compounds (ORC), time release nutrients, and a microbial consortia (to rapidly increase the number of aerobic hydrocarbon degrading microbes in the subsurface).
• Injection points are done on a grid surrounding the contamination to ensure full remediation and build barriers to prevent off-site pollutant migration.

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