Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest National Laboratory (PNNL)(a) for the U.S. Department of Energy (DOE). Sampling is conducted to evaluate levels of radioactive and nonradioactive pollutants in the Hanford environs, as required in DOE Order 5400.1, 'General Environmental Protection Program,' and DOE Order 5400.5, 'Radiation Protection of the Public and the Environment.' The sampling design is described in the Environmental Monitoring Plan, United States Department Energy, Richland Operations Office, DOE/RL-91-50, Rev. 2, U.S. Department of Energy, Richland, Washington.