Abstract: A modular, enclosed, interchangeable hazardous material treatment plant is disclosed. The treatment plant can utilize any one of a variety of abatement technologies for treating an unauthorized discharge of hazardous material, including spray aeration, vacuum extraction, biological, carbon, ozone, ultra-violet, or other. Regardless of the type of plant, connection to the site is made between the enclosed plant and the standard underground connection port which contains connection to all underground piping. No on-site assembly or disassembly of the plant is required. If a succession of treatment plants is required, one can be disconnected and the next connected within an hour. During treatment, all that is visible above ground is the enclosure. After treatment of the site is complete, the only visible remainder of the plant is the cover of the underground connection port.