[en] A pilot-scale treatability test was performed in the 200-ZP-1 groundwater operable unit, located in the 200 West Area of the Hanford Site. The performance of the test was based on the Treatability Test Plan for the 200-ZP-1 Operable Unit (DOE-RL 1994b) and an agreement between the US Department of Energy (DOE), the US Environmental Protection Agency (EPA), and the Washington State Department of Ecology (Ecology) documented in the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) (Change Control Form M-13-93-03). The pilot-scale treatability test was conducted on the volatile organic compound (VOC) contaminant plume associated with the 200-ZP-1 Operable Unit and focused on assessing the performance of an aboveground treatment system with respect to its ability to remove carbon tetrachloride, chloroform, and trichloroethylene from extracted groundwater