Bioremediation with Mushrooms to Clean Contaminated Landscapes

Studies by the U.S. Geological Survey (USGS) have shown that microorganisms naturally present in the soils actively consume fuel-derived toxic compounds and transform them into harmless carbon dioxide.

Furthermore, these studies had shown that the rate of these biotransformations could be greatly increased by the addition of nutrients. By "stimulating" the natural microbial community through nutrient addition, it is possible to increase rates of biodegradation and thereby shield the residential area from further contamination.

In 1992, this theory was put into practice by USGS scientists. Nutrients were delivered to contaminated soils through infiltration galleries, contaminated ground water was removed by a series of extraction wells, and the arduous task of monitoring contamination levels began. By the end of 1993, contamination in the residential area had been reduced by 75 percent. Nearer to the infiltration galleries (the source of the nutrients), the results were even better.

Ground water that once had contained more than 5,000 parts per billion toluene now contained no detectable contamination.

Bioremediation had worked!

Through the Toxic Substances Hydrology Program, of the US Geological Survey (USGS) the most important categories of wastes have been systematically investigated at sites throughout the United States.

One of the principal findings of this program was that microorganisms in shallow aquifers affect the fate and transport of virtually all kinds of toxic substances.

Examples of successful projects of contamination cleanup using bioremediation include a crude oil spill in Minnesota; sewage effluent cleanup in Massachusetts; chlorinated solvents transformation in New Jersey; pesticide contamination of rivers in the San Francisco Bay Estuary; agricultural chemicals in the Midwest; gasoline contamination in New Jersey; and creosote contaminant wood preservatives in Florida.

The Hanahan Bioremediation Project is just one of many successful bioremediation experiments that can be traced to basic research carried out by USGS scientists. Methods and technology developed in the Toxic Substances Hydrology Program are now being used by private contractors, State environmental managers, and other Federal agencies to address contaminant problems throughout the United States.

Stretching Remediation Dollars

Cleaning up existing environmental contamination in the United States could cost as much as $1 trillion dollars. Bioremediation can help contain costs as
follows:

Treating contamination in place
---Most of the cost associated with traditional cleanup technologies is associated with physically removing and disposing of contaminated soils. Because engineered bioremediation can be carried out in place by delivering nutrients to contaminated soils, it does not incur removal-disposal costs.

Harnessing natural processes
---At some sites, natural microbial processes can remove or contain contaminants without human intervention. In these cases where intrinsic bioremediation (natural attenuation) is appropriate, substantial cost savings can be realized.

Reducing environmental stress

---Because bioremediation methods minimize site disturbance compared with conventional cleanup technologies, post-cleanup costs can be substantially reduced.

For more information contact any of the following:

• The Toxic Substances Hydrology Program, USGS, 412 National Center, Reston, Virginia 20192, (703) 648-6862
• Additional earth science information can be found by accessing the USGS Home Page
• Additional information about the Toxics Program can be found by accessing the Toxics Program's Home Page
• USGS Node of National Geospatial Data Clearinghouse
• For more information on all USGS reports and products (including maps, images, and computerized data), call 1-800-USA-MAPS