Abstract: A condensate trap for use in a Vapor Extraction System (VES), which uses negative pressure to extract contaminated vapors from soil, is disclosed. The trap includes a vapor tight vessel, part of which acts as a condensate reservoir. One or more mist eliminators, such as an impingement type condensate collector, are contained within the vessel. The vessel includes a vapor inlet and a vapor outlet as well as a condensate outlet. The condensate outlet is controlled by a swing check valve. The valve remains closed until there is sufficient condensate in the reservoir to push it open. After a predetermined amount of condensate drains out, the check valve closes.