Soil samples from the small arms ranges of three DOD military bases — Fort Dix, New Jersey; Twentynine Palms, California; and NAS Miramar, California — were provided for treatability studies. The treatability results were used to select the site for the field demonstration. The selection was based on the criteria that most closely met the capability of the pilot plant equipment and included:

About 25% of the soil as coarse fractions, +1.19 mm (+16 mesh), and at least 25% as sand fractions, −1.19 mm by +105 μm (+150 mesh);

At least 50% of the coarse and sand fractions requiring vat leaching;

At least 25% as slimes fraction, −105 μm, for testing the Knelson bowl concentrator; and

At least 25% of the total soil mass as −105 μm soil requiring agitation leaching.