TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Methods: The nutrient mix is delivered by delivering the nutrient mix by bioventing or biosparging. The method also comprises:(a) delivering to the contaminant zone a population of microorganism(s) capable of metabolizing the organophosphorus nutrient to produce inorganic phosphates;(b) providing an extraction well, thus extraction from the extraction well enhances permeation of the nutrient mix through portion(s) of the contaminant zone;(c) assaying the contaminant zone to determine the type and amount of metal contaminants;(d) assaying the contaminant zone to determine the nutrient requirements of microorganisms;(e) creating a vapor phase nutrient mix;(f) delivering the nutrient mixture at a delivery point to the contaminant zone; and(g) continuing the delivering so that the microorganisms metabolically produce inorganic phosphates in an amount calculated to create a concentration of the inorganic phosphates in the contaminant zone to immobilize the metal contaminants within the contaminant zone.The amount of inorganic phosphates is calculated by using the condition stating that the concentration of inorganic phosphate is equal to the solubility product for the solid divided by the final concentration of the contaminant metal raise to the power x, raise to the power one half y.x, y = the empirical formula Mx(PO4)y for a solid formed by the interaction of the contaminants metal with valence of +The delivering of the nutrient mix is continued to allow the microorganism to metabolically produce inorganic phosphates in the contaminant zone of 0.1 mg/L.Preferred Components: The organo phosphorus nutrient is an alkylphosphate ester. The alkylphosphate ester is triethylphosphate, tripropylphosphate, and/or tributylphosphate. The microorganism is capable of metabolizing the organophosphorus nutrient to produce inorganic phosphate. The microorganism metabolically utilizes glycerol 2-phosphate. The organophosphorus nutrient is delivered in an excess amount required for cell mass formation.