[en] The objective of this project is to design and develop a physico-chemical treatment process for the removal of uranium and heavy metals from contaminated soil to achieve target contamination levels below 35 pCi/g of soil and a target for non-radioactive heavy metals below concentration levels permissible for release of the soil. The work will involve bench-scale and pilot-scale tests, using chelation-flotation, chemical leaching and ultrasonic leaching techniques, in conjunction with cross-flow microfiltration and filter-press operations. The effectiveness of an integrated process to treat leachates generated from soil processing will be demonstrated. Process flow-sheets suitable for in-situ and ex-situ applications will be developed and preliminary costs will be provided for the soil and leachate treatment technologies. The Task 2 Topical Report (milestone No. 4) summarizing contaminant removal results obtained from bench-scale studies using Fernald uranium soils and Chalk River Laboratories Chemical Pit soils was completed and issued on August 8, 1994. The results have shown that the soils containing uranium (about 400 pCi/g of soil) and strontium-90 (about 1200 pCi/g of soil) can be decontaminated to the target level of 35 pCi/g of treated soil in the presence of an ultrasonic field. Preliminary results obtained from the in-situ soil leaching tests are the average strontium-90 concentration in the cell was about 250 pCi/g; and the use of a dilute mineral acid (0. 1 mol/L HCl) removed in excess of 85% of strontium-90 originally present in the soil