Investigating RefineryWastewater Impacts on Groundwater Sources  A Case Study of Pars Oil Refinery

Pars Oil Refinery, situated 22 km away from metropolitan Tehran, is one of the most important motor oil refineries in the country. Currently, the refinery is composed of various sections including the Furfural, Separation, Storage, Blending, Canmaking, Barrel-making and Dyeing, Loading and Unloading, Antifreeze, Grease-making, Boiler, Repair, and Laboratory Units. In the study area, because of such reasons as the high groundwater table the company has failed to launch the biological section of its wastewater treatment plant. In addition, with the possibility of effluents from residents’ sanitary wastewater as well as those from agriculture lands penetrating the soil and ending up in the underground water of the studied area, the present research was conducted on such an environmental dilemma. In order to investigate the hypothesis of effluent penetration into underground water, four stations were selected from among water wells existing throughout the area, and then the parameters of pH, chemical oxygen demand (COD), biological oxygen demand (BOD), nitrate, colour, nitrite, electrical conductivity (EC), sulfate, dissolved solids, ammonia, furfural, heavy metals, and total petroleum hydrocarbon (TPH) were analyzed. It is noteworthy that the analyses were conducted on water samples seasonally from December 2006 to May 2009. Afterwards, through comparison of the results obtained from the forenamed tests and using standard values, the research hypothesis was confirmed. In other words, effluents do penetrate the wells and pollute the underground water.