Soil vapor extraction (SVE) is an effective and cost-efficient method of removing volatile organic compounds and petroleum hydrocarbons from unsaturated soils. However, SVE becomes ineffective in soils with low permeability--for example, soils with air permeabilities less than 1 Darcy. Prefabricated vertical drains (PV drains) have been used to dewater fine-grained soils for more than 20 years. For the last 5 years, PV drains have been used for soil flushing applications to remove contaminants below the groundwater table. Incorporating PV drains in an SVE system can extend the effectiveness of SVE to lower permeability soils by shortening the air-flow paths and ultimately expediting contaminant removal. An advantage of using PV drains in place of conventional SVE wells is that they can be installed relatively inexpensively. The objective is to effectively incorporate PV drains into an SVE remediation system and to demonstrate a PV drain-enhanced SVE system at full scale.
Samenvatting