Remediation in an Occupied Residential Building


One of the most prestigious real estate organizations in the northeast called upon CA RICH to expedite an investigation and mitigate mysterious intermittent oil seepages into the basement of one of their high-rise residential properties in Manhattan. The suspected source of the leak was an exterior buried tank vault located beneath an adjoining sidewalk, containing No.6 heating oil. This type of heating oil is especially difficult to clean because of its thick and viscous nature. Not surprisingly, the Tenant Corporation demanded the least amount of disruption to this fully occupied and active, prestigious building.


CA RICH recommended design and installation of a unique interior oil recovery system to operate in-situ in the building’s deep sub-basement. The system incorporated dual-phase extraction equipment, combined with steam injection to thin the exterior oil, with a surfactant application to eliminate the dissolved component. To avoid disrupting the residents, system components were assembled inside the building, rather than placed in a typical pre-fabricated form. In an innovative step, CA RICH injected steam heat from the building’s heating system during off-peak hours to help mobilize the oil, at several different locations beneath the foundation. Once sufficient No. 6 oil product had been thinned and removed, the interior walls were sealed and the spill declared closed by both State and City regulatory agencies.