CASE STUDY OF TCE ATTENUATION FROM GROUNDWATER TO INDOOR AIR AND THE EFFECTS OF VENTILATION ON ENTRY ROUTES

摘要

An investigation of groundwater -to-indoor air vapor intrusion of trichloroethylene (TCE) was conducted at a commercial building to 1) identify vapor pathways; 2) measure TCE attenuation ; 3) evaluate whether building pressurization can reduce vapor intrusion; and, 4) evaluate seasonal effects on vapor intrusion. The investigation included a site assessment, both indoor and outdoor air sampling, and the modification of the existing heating, ventilation and air-conditioning system. The investigation found that preferential pathways, such as a floor crack, acted as conduits for vapor intrusion when the building was not properly ventilated. The investigation also found that air TCE concentrations were significantly atte nuated between ground surface and the breathing zone and proper building pressurization can effectively minimize vapor intrusion. Weather conditions at the site did not significantly affect the indoor air TCE concentrations.