This paper presents the geotechnical analysis of foundation soil affected by domestic waste water. So, five group of fine grained samples are prepared and mixed with different amount of waste water 0.0%, 25%, 50%, 75% and 100% of moisture content. The physical, geotechnical and mechanical properties are determined for each soil sample at variant test periods (14, 28, 56, 112, and 168 days from mixing day). These properties include Atterberg liits, specific gravity, particle size distribution, compaction characteristics, consolidation behavior and compression strength. Moreover, mineralogy, chemical composition, cation exchange capacity, surface area and soil particle structure of each soil sample are estimated. This paper generally concludes that the physical geo-technical and mechanical properties of fine grained soil are changed to the worest due to the seepage of waste water through the soil.