Considerable evidence, both theoretical and experimental, support the assertion that lead phosphates are the most stable environmental soil lead form and that they may form rapidly when adequate phosphate is present. This study demonstrated that the weathering of galena to insoluble lead phosphates in soils at a port facility historically used for shipment of ore concentrates is due to the presence of adequate soil phosphate. Geochemical modeling indicated that the addition of a phosphate amendment to Pb-bearing soil would result in lead phosphate formation with an estimated aqueous lead solubility of 0.1 μg/L in soil