The chemical characterization of soils needs to be evaluated properly before its use as foundation, as a fill material, and for any civil engineering applications. The core chemical parameters required for assessing its suitability as a foundation material are pH, Total Soluble Salts, (TSS), Calcium Carbonate Content, Organic Matter, Water Soluble Sulphate, and Water Soluble Chloride. The use of soils as fill materials for making earthen dams, embankments, and canals requires chemical analysis of pore water extract to identify its dispersive characteristics. The pH of soil water extract indicates its acidic and alkaline characteristics. The value of pH below 6.0 will lead to corrosion and leaching phenomenon, and high alkaline range is an indication of the presence of excess salts in the soils causing physical crust. The presence of soluble salts in a soil is one of the important aspects requiring examination since these water soluble salts greatly influence the engineering properties of soil. Calcareous soils are identified by the presence of high amount of calcium carbonate (CaCO3). Carbonate content can be used as an index to assess the quality of chalk as a foundation material. Estimation of organic matter is important for the purpose of stabilization of soil and swelling capacity of expensive soils. Estimation of sodium, potassium, calcium, and magnesium ions in soil pore water extracts will be carried out to establish soils’ dispersive behavior. Soil mineralogical examination by X-ray Diffraction (XRD) method is important tools to identify soils mineral compositions. This paper presents the chemical investigations of soils of different nature, i.e., acidic, alkaline, calcareous, and dispersive for their suitability as foundations and as fill materials in civil engineering applications. Soil samples received from different irrigation/multipurpose river valley projects were analyzed (as per standard codes and practices), interpreted, and correlated.