Abstract. On-site land application of waste water containing very low levels of site-derived contaminants is a commonly used method of disposal. However, the residual soil contamination resulting from such practices may complicate and increase the costs of site remediation if constituent soil concentrations exceed regulatory clean-up standards. The long-term potential human health impacts of land application of waste water containing elevated levels of naturally occurring radionuclides for a hypothetical in-situ uranium facility were investigated using the U. S. Department of Energy RESRAD Computer Code for assessment of dose and risk. The post-reclamation radiation doses in excess of background, attributable to land application of waste water containing uranium and its decay products thorium and radium, were calculated for several different conditions assuming rural-residential use of the land. For contaminated land areas of 10 acres or more, the estimated doses were directly proportional to the soil radionuclide concentration when the thickness · of the contaminated soil and hydrological parameters were held constant. The maximum annual radiation dose to a rural resident on land with surface soil concentration equal to 205 pCi/g natural uranium was estimated to be 34 mrem. In contrast, the maximum annual radiation dose to this hypothetical individual from 22 6Ra at the residual concentration allowed under the regulations for uranium mill tailings, i.e., 5 pCi/g, varied from 135 mrem to 283 mrem depending on the thickness of the contaminated layer.Additional