The Grout Treatment Facility (GTF) site is planned for use as a shallow land burial site for the disposal of low-level liquid radioactive waste that is solidified mixing the waste with a cementitious grout material. To determine if the GTF is impacting the environment at any time during future operations, two preliminary objectives must be completed: the preoperational environmental conditions must be described, and the baseline parameters of the physical system must be defined. Both objectives were addressed by conducting site characterization activities and using the collected data to establish a baseline (background) that describes the current physical system and how this system will eventually change through time. The specific physical systems for which baselines were determined and characterization was completed at the GTF site including the following: atmospheric, radioecologic, geologic, and hydrologic. Data collection has been continuous since 1984. The US Department of Energy's regulations and Westinghouse Hanford Company internal policies guided the studies. The 0.4 mi/sup 2/ GTF site is located in the Pasco Basin in south-central Washington State at the Hanford Site. Atmospheric and thermoluminescent dosimeter (TLD) data were collected from an existing routine environmental surveillance network and at three other stations established for this investigation tomore » measure levels of radiation at the GTF site. The atmospheric data indicated that airborne radionuclide levels were below maximum permissible concentrations from 1985 through 1987. The TLD results for the three constructed stations ranged from 84 to 97 mrem/yr in 1987. This represents an increase (about 10%) from the 1986 dosage values. 32 refs., 22 figs., 7 tabs.« less