| Funnel and Gate technologies are inappropriate for remediating groundwater contamination in low permeability sediments like glacial tills, because the design produces mounding effects which force flow underneath and around funnel walls.; The Trench and Gate is a modified Funnel and Gate system suitable for installation in tills. Modifications include the addition of high hydraulic conductivity trenches along the up-gradient side of the funnel walls and a reinfiltration gallery down-gradient of the treatment gate. Preferential groundwater flow through the added high permeability infrastructure prevents mounding and induces a capture zone both horizontally, and vertically larger than the cross-sectional funnel area. Coupled with bioremediation catalyzed by biosparging, or other remediation technologies, the system constitutes an economical, in-situ, long-term contaminant plume capture and treatment method, suitable for low to moderate permeability sediments. A prototype Trench and Gate was successfully installed at the East Garrington Gas Plant, Alberta, Canada. |
