[en] Operations at the Hanford Site in southeast Washington State have resulted in the presence of low-level radioactivity in the groundwater beneath the Hanford Site. Routine monitoring of groundwater over the years has shown that this low-level radioactivity is migrating with the groundwater into the Columbia River, which borders the Site. Monitoring of the Columbia River has indicated that a very slight increase in ¹²⁹I is detectable in the river downstream of the known region of groundwater entry into the Columbia River. Springs which feed groundwater into the Columbia River were studied to identify and characterize this probable source of the Hanford contribution of radioactive materials to the river. Fluctuations in river stage, due to changes in water flow rates past dams upstream and downstream of the site, resulted in periodic covering and uncovering of some 114 springs and seepage areas along the Hanford shoreline. Selected springs and locations in the river were sampled and analyzed for several constituents present in the groundwater. Concentrations of materials in the springs ranged from background river levels to levels found in nearby groundwater monitoring wells. In some instances, elevated spring concentrations produced locally elevated river concentrations; but concentrations were rapidly diluted to near-background level by the river within a relatively short distance downstream of the spring discharges. 4 references, 2 figures, 1 table