1.1 These methods determine the water soluble sulfate content of cohesive soils used in construction by using the colorimetric technique. Two methods are presented in this standard. Method A is for use in the field and Method B is for use in the laboratory. The colorimetric technique involves measuring the scattering of a light beam through a solution that contains suspended particulate matter. Measurements of sulfate concentrations in construction soils can be used to guide professionals in the selection of appropriate stabilization methods and to assist in assessment of potential deterioration in concrete structures.