Siwa Oasis is one of the most promised locations in the Western Desert of Egypt for future agricultural projects as a result of groundwater availability. In addition, it has historical, medical and environmental tourism importance. However, the uncontrolled abstraction and use of groundwater may lead to much environmental deterioration for soil and groundwater aquifer. This study dealt with the water quality of both shallow and deep aquifers in Siwa. The hydrochemical studies indicated the meteoric origin of deep aquifer and its suitability for different uses. Also, this water is free of As, Cd and Pb as well as contains acceptable levels of Cu and Zn. On the other hand, the shallow aquifer was very saline with TDS≥1651 ppm. Accordingly, this water is unsuitable for drinking. The main process controlling salinity of this aquifer was evaporation process. The salinity of water makes it detrimental for irrigation except under certain conditions. The most advantage of this water its acceptable SAR in most samples as well as acceptable levels of the studied harmful heavy metals. So it is restricted for the irrigation suitability. Unfortunately, the surface area of lakes was duplicated in the last 13 years as a result of uncontrolled irrigation. The application of new irrigation technology and cultivation of salt tolerant plants is recommended.
