Venting means the injection of air. The technology uses the ability of indigenous soil bacteria to degrade contaminants. Contaminated soil vapour is extracted via wells and the extracted contaminated air is then cleaned. Ambient air replaces the extracted soil vapour and delivers oxygen activating bacterial biodegradation activity. Benefits: Low investment and maintenance cost, a high efficient technology. The technology is applicable for all volatile contaminants, mainly aromatic hydrocarbons and petroleum hydrocarbons in the unsaturated zone.