Risk Assessment of Petroleum Substances from Upstream of Dez Dam in the Groundwater to the Reservoir of Dez Dam Using the Development EPA Method

The aim of this research is investigate quality of underground and Surface water of the Dez Dam lake. Existence of two oil fields (Qala Nar and Balaroud), upstream of Dez Dam and their inclined slope towards Dez Dam Lake, Will affected the release of oil pollutants through underground water to the Dez Dam. Risk assessment development has been done using EPA method. The samples of underground water and Dez dam reservoir were analyzed by gas chromatograph to determine the amount of total petroleum hydrocarbons. The new risk assessment equation (HRA) formulated by considering the importance factor. Analytical Hierarchy Process (AHP) used to evaluate the degree of health importance of petroleum hydrocarbons in the range of C10, C20, C30 in underground water and Dez Dam and the probable risk to human health was calculated according to the EPA standard and the new method for carcinogenic and non-carcinogenic risk. According to the EPA, the results of this research do not include cancer slope (CSF), as a result, there is no risk of carcinogenesis in the existing samples but they have a non-carcinogenic. C10 and C22 hydrocarbons entered the dam from underground water, C10 in the EPA method with a rate of 1.94 and in the new method (HRA) 1.13 has the highest probability of non-carcinogenic risk. Results obtained from the EPA equation and the new HRA formula in this research showed that the total petroleum hydrocarbons entered the underground water and dam lake and have a high probability of non-carcinogenic risk.