What is natural attenuation?
When petroleum products such as gasoline, jet fuel or diesel fuel are spilled or leak into soil or groundwater, several natural processes begin to destroy or alter the chemical components of the fuel. These processes include adsorption on soil particles, biodegradation, and dilution and dispersion in groundwater (see Components of Natural Attenuation on the next page). “Intrinsic” and “passive” remediation are other terms that have been used to describe the combined effect of these processes. Dr. John Wilson of the EPA compares natural attenuation in groundwater to a lighted candle. The source of the flame is the wax of the candle, just as the source of the groundwater contamination is the more concentrated petroleum trapped in the soil. The flame appears steady because the wax is destroyed in the flame as fast as it is removed from the candle. In the same way, the groundwater plume will reach “steady state” at some distance from the source when natural bacteria are able to destroy con
