Performance Comparison of Interceptor Trench Configurations for Extracting Contaminated Groundwater

Abstract

Computer simulations tested the capability of five alternative interceptor trench configurations to capture an enclave (plume) of contaminated groundwater. The configurations included a single linear segment and angled segments, at 90° and 135°, with a common endpoint. Alternative angled configurations both faced and opposed the contaminant plume. Each trench configuration had the same total length and was located the same average distance from the contaminant plume. The minimum pumping rate required to capture the plume and a surrounding buffer zone, within a prescribed time period, was determined for each trench configuration. The 90° plume-opposed trench performed best, requiring approximately one-third the pumping rate of the 90° plume-facing configuration. The plume-opposed configuration yielded a capture zone that best conformed to the actual shape of the contaminant plume, thereby reducing the amount of groundwater that had to be removed from the aquifer to remove the contaminant plume. Ironically, plume opposed configurations are rarely used in practice. Results of this study suggest that alternative interceptor trench configurations, including funnels with mouths opposed to contaminant plumes, should be tested with computer simulations when devising protocols for groundwater remediation.

Keywords:

• Interceptor trench
• Contaminant plume
• Groundwater