Index and Compaction Properties of Oil Contaminated Clay Soils in Niger - Delta Region of Nigeria

Oil Exploration in Nigeria has contributed greatly towards pollution of the environment especially in the Niger Delta region of the country where most of the oil wells are located. In the process of their operations which include; drilling, refining transportation etc., oil spillage occurs which pollutes land, air and water bodies. This results to the release of dangerous gases into the air. Properties of soils in the contaminated areas are highly affected leading to poor agricultural produce and alteration of geotechnical properties of soils which may adversely affect engineering construction works. This research work examines the effect of crude oil pollution on the geotechnical properties of clay soil. The clay soil was obtained from Engenni Ahoada L.G.A of Rivers, Nigeria. Soil samples were collected at a depth of approximately 2 meters below the ground surface and artificially polluted with crude oil in the ratio of 0%, 2%, 4%, 6%, 8%, 10%, 12%, and 14% of the dry weight of the soil. The samples were further subjected to various laboratory soil tests to determine their geotechnical properties. The results shows LL, PL, and PI increased from 31%, 20% and 11% at 0% contamination to 56%, 41% and 11% at 14%contamination. SPGR, BD, and MDD decreased from 2.48, 1.33g/cm 3 and 1.74g/cm 3 at 0% contamination to 1.14, 0.97g/cm 3 and 1.35g/cm 3 at 14% contamination. OMC increased from 15% at 0% contamination to 16.5% at 14% contamination. Thus, crude oil pollution affects the geotechnical properties of soil greatly.