The US Department of Energy's Pacific Northwest Laboratory in Richland, has recruited an army of microorganisms to clean soils and underground water tainted with nitrate and carbon tetrachloride - an industrial solvent that is a suspected carcinogen.

In this bioremediation process, native bacteria which can be coaxed into degrading contaminants are energised. A food source, in this case vinegar, spurs the microbes to eat the carbon tetrachloride and other contaminants. The scientists hope to clean up in this manner a trillion litres. of groundwater contaminated with carbon tetrachloride.