Soil including sand and clays contaminated with nuclear waste materials and/or ions of hazardous non-radioactive metals or metalloids are decontaminated by treating with anhydrous liquid ammonia alone or in combination with solvated electrons. Methods include removing ions of hazardous metals or metalloids by mixing with ammoniacal solutions to provide an ammoniacal liquid-containing product with coordination complexes. Methods also comprise concentrating contaminants, such as plutonium, uranium and thorium, for example, in the fines of soil and clay to yield residual soil products which are sufficiently free of contaminants to allow reclamation. Economics are improved over aqueous systems since ammonia canbe recovered and recycled. By concentrating nuclear and non-nuclear wastes in soil fines space requirements ordinarily needed for storage of untreated soil and handling costs can be significantly reduced.