In situ and on-site subsoil and aquifer restoration at a retail gasoline station

The technique of venting to remove petroleum vapors and volatile petroleum products from the vadose zone is presented in this paper. In addition to the possibility of enhancing the evaporation of volatile organics, venting can also be used to enhance convective air transport in soil to stimulate the oxygen-dependent petroleum biodegradation in the vadose zone. The possibilities for bioventing were indicated by lysimeter studies on a microbially mediated gas-oil mixture (gas-oil) removal from sand. In the absence of bioventing, an almost 100 percent removal was achieved in a period of 8 years. A feasibility study subsequently carried out confirmed the possibilities for the enhancement of biodegradation by bioventing. a large-scale field experiment was started in 1984 to validate the feasibility study. The next step is to develop this methodology further in a real spill situation. After careful consideration and screening, the contaminated area surrounding a retail gasoline station was selected as a test case to develop and demonstrate the feasibility of the approach