Soil vapor extraction is a remediation technology that applies a vacuum to extract contaminated vapor that is adsorbed to soils and to collect the vapor for treatment.
Studies have found this technology to be most effective for remediation of volatile organic compounds and some semi-volatile organic compounds. This technology is often used in combination with air sparging or biosparging.
A horizontal soil vapor extraction system has a longer interval of screen in contact with the contaminated zone and provides a greater recovery in the vertical dimension, creating a much greater zone of influence than typically can be achieved with vertical wells. Horizontally drilled extraction wells are therefore more efficient and are also less likely to short-circuit to the atmosphere than those installed by trenching, since the soil column is not disturbed during the installation process.
In a horizontal system, the line acts as both the recovery and the conveyance lines. The same pipe provides both the screened section to extract vapors and a blank section to carry the vapors back to the surface. A single pipe can thereby replace both a series of vertical wells and the near-surface trenched conveyance lines required to transport the extracted vapor to the treatment system. We have installed these horizontal soil vapor extraction systems at dozens of sites where there was no disruption of normal site activities, including sites where the well or wells were installed beneath the floor slabs of active industrial facilities such as warehouses and factories.
Using our patent-pending Knock-Off™ technology, which enables us to install long, single-ended wells in difficult drilling conditions, DTD has installed SVE wells with lengths up to 1500 feet beneath runways at several Air Force and Air National Guard bases. Wells of this length approach the practical limits of SVE methods, due to the requirements for keeping even vaccum pressure across the screened interval of the well.
DTD designs effective SVE systems in house, as well as working with experienced consultants to design wells that are effective in meeting client and regulatory clean up objectives.