Soil Vapour Extraction (SVE)

Soil Vapour Extraction is a technique based on the physical removal of organic contaminants from the soil matrix by inducing a localised vacuum. The system is designed to remove volatile hydrocarbons from the zone between the surface and the groundwater, commonly termed the “Vadose” zone. The technique involves drilling vertical wells or horizontal lines and inducing a vacuum in the wells. The extracted air and vapour is then treated at the surface.

The advantage of this method is that contaminants can be extracted without the need for excavation or the injection of compounds required for in-situ chemical oxidation or bioremediation.

Ecologia also use SVE systems to implement Bioventing. This technique utilises the vacuum to induce mass transfer of gases in the unsaturated zone to provide oxygen for bacteria as the aim of the technique rather than remove volatile compounds. This technique relies upon the target contamination being biodegradable and overcomes the sub-surface mass transfer problems associated with other in-situ bioremediation techniques.

Ecologia is able to undertake all aspects of the design and implementation of SVE in-house, from drilling and installation of the extraction wells to manufacture of the treatment system. Following installation the system would be operated and monitored by our qualified environmental scientists and Technically Competent persons (CoTC holders) when our mobile treatment licence is in force.

Ecologia’s SVE systems can be coupled with our RF Heating system to enhance the rate of recovery or to increase the range of contaminants that the process can treat. The soil heating will volatilise higher molecular weight compounds which a traditional SVE system will not be able to treat.

Soil Vapour Extraction is able to achieve rapid removal of light hydrocarbons, such as petrol and solvents from relatively porous ground without the requirement for excavation or the injection of the compounds that are required for in-situ bioremediation. Contaminants found in the off gases are removed using a filter such as an activated carbon or biological filter or catalytic oxidation. SVE is commonly coupled with air sparging to remove volatile contaminants from groundwater.