The present work is devoted for studying the geotechnical and chemical properties of intact and contaminated sandy soil samples. The soil samples were obtained from Al-Kufa city that is located in the south-west of Iraq. The contaminant is a by-product industrial wastewater disposed from the refinery that supplies fuel for the thermal electricity power plant. The intact sandy soil samples were contaminated in the laboratory with four percentages of 10, 20, 40 and 100% of the weight of distilled water used in the soaking process and the soaking process continued for thirty days. The results of tests showed a slight increase in both liquid limit and particle size and a significant increase in the optimum moisture content with increasing the percentages of the contaminant. However, with increasing the percentages of the contaminant, there was a slight decrease in the specific gravity and maximum dry unit weight. In addition, there was a considerable decrease in the angle of internal friction and the coefficient of permeability. The angle of internal friction of contaminated soil samples decreased by 18 to 26% with increasing the contaminant percentage from 10 to 100%. The cohesion of soil samples decreased by 7 to 33% with increasing the contaminant percentage, this conclusion is limited to the soil samples contaminated with 10, 20 and 40%, but the cohesion of soil sample contaminated with 100 % of industrial wastewater increased by 7%.