Potential Occurrence of MTBE and BTEX in Groundwater Resources of Amman–Zarqa Basin, Jordan

This study investigates potential occurrence, distribution, and sources of the newly added gasoline oxygenate, methyl-tert-butyl ether (MTBE) and the petroleum derivatives benzene, toluene, ethylbenzene, and xylenes called collectively, BTEX, in Jordan's heavily populated AmmanZarqa Basin (AZB). It presents the first data on the levels of MTBE and BTEX in the aquifers of this basin. One hundred and seventy-nine (179) groundwater wells were sampled near petrol service stations, oil refinery storage tanks, car wrecks, bus stations, and chemical industries at different locations in the basin. Headspace GC and purge and trap GCMS were utilized to determine the target substances in the samples. Concentrations of BTEX varied between no-detection (minimum) for all of them to 6.6?mu g/L (maximum) for ethylbenzene. MTBE was found in few samples but none has exceeded the regulated levels; its concentrations ranged between no-detection to 4.1?mu g/L. However, though the contamination levels are very low they should be considered alarming.