Field Study to Investigate WIDE Technology for TCE Extraction

A full-scale field study was conducted using well injection depth extraction (WIDE) technology to remove trichloroethylene (TCE) from subsurface profiles with fine-grained soils. WIDE incorporates the use of geosynthetic wick drains, attached to an aboveground PVC pipe network, designed to (1) extract contaminated fluids from a specific depth using vacuum pressure, and/or (2) inject flushing solutions. Both extraction-only and concurrent injection-extraction testing schemes were conducted, and fluid flow rates, TCE recovery rates, and groundwater elevations were monitored over a 9 month time interval. During extraction-only operational schemes, gas-phase TCE extraction rates were significantly higher than liquid-phase extraction rates due to the increased volume of air within the geosynthetic wells and PVC piping. TCE extraction rates were less than 2,000 mg/h for airflow rates less than 100,000 L/h, and increased significantly to 5,700 mg/h as the airflow rate approached 600,000 L/h. Long term testing and sampling is needed to quantify system performance and determine tailing and rebounding effects in comparison to conventional methods. The behaviors and trends observed during the field study are presented and discussed.