Concentric’s geoscience group was retained by a national insurance company to respond to an extensive residential heating oil leak that had affected soil, groundwater, surface water, site drainage infrastructure (e.g. sump and weeping tile) and off-site properties. The assignment involved the installation and sampling of 28 monitoring wells, sampling of surface water and a closed circuit television (CCTV) inspection of the weeping tile and other subsurface drainage piping. The remedial action plan involved removal of impacted soil and surface water from an adjacent drainage ditch, excavation of impacted soils in the release area, redirection of groundwater to an on-site GAC treatment system and implementation of an in-situ chemical oxidation remediation program. This included a surfactant flush and subsequent oxidant treatment of the weeping tile as well as targeted groundwater injections. All remedial activities were completed successfully, restoring site and off-site conditions to regulatory standards, without having to displace the residents or affect any building components.