Cleaning Up the Soil

Cleaning Up the Soil

Industries spend millions of dollars to clean up hazardous wastes. Just one 55-gallon drum of waste can contaminate a lot of soil and water. Although new regulations ban traditional landfill waste, it was not long ago that hazardous waste was routinely dumped in landfills and at many manufacturing sites.

Liquids and solvents can leak into the soil causing contamination. Cleanup costs are enormous and often prevent businesses from continuing normal operations. Numerous industries are faced with the the challenge of cleaning up the soil.

When soil is contaminated, it may be mixed with lime which neutralizes the harmful elements. However, this method is not always successful. Most of the time, soil must be dug up and transported via trucks to special landfills and incinerators. In addition to high costs, transporting contaminated soil puts people at risk.

During the last decade, scientists have been exploring innovative alternatives to save money and to improve safety. Overall there are more than one hundred new technologies in various stages of development. The new technologies focus on treating the contamination on-site as opposed to established technologies where treatment is conducted off-site. Supporters contend that these new technologies will lead to a more complete cleanup at a fraction of the cost.

Pollution-Eating Bacteria

Pollution-eating bacteria are used to clean soil that is contaminated with petroleum wastes. Researchers have successfully developed a bacteria that reduces the complexity of oils and gasoline.

Soil Washing

Another new method is soil washing. A solution of detergents has been developed that washes the PCBs and oils from soil. The solution soaks down through the soil and collects the PCBs at the base of the soil. The PCBs can be seperated from the solution and are incinerated. The solution can then be reused after the PCBs are extracted.

Bioremediation

A natural soil bacteria has been developed to clean groundwater and soil that is contaminated with chlorinated solvents such as those found in dry cleaning fluids. Test results show that this bacteria has cleaned water sufficiently to meet EPA drinking water standards. This process of using a natural bacteria to clean the water is called bioremediation.

Bio-venting/Vacuum Extraction

Bio-venting stimulates the growth of pollution-eating microorganisms by pulling surface air down through contaminated soil. The ground surface is covered with plastic sheeting, and a vacum pump installed in a well below the ground pulls the surface air down.