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El Shalateen-Halayeb triangle is a promising district for tourism and agricultural development. Pre-Miocene rocks (fractured basement and Nubia sandstone) represent the main water-bearing formations in the investigated area. Rainfall and occasionally flash floods represent the main sources of recharge. Groundwater occurrence and movement in basement aquifer is mainly controlled by the Structural elements, where interaction between fractures and intrusive dykes reflect a good environment for groundwater entrapment. In fractured basement aquifer, the transmissivity ranges from 2.75 m(2)/day to 784 m(2)/day. Such wide variation Could be attributed to the lateral facies changes as well as the impact of the complicated structural setting. Nubia sandstone is detected as a water-bearing in Abraq, Abu Saafa and EL Dif localities, its transmissivity varies frorn 2.72 m(2)/day to 72.4 m(2)/day. Poor potentiality of aquifers is mainly due to high channel gradient, which gives no chance for groundwater replenishment. Regionally, the direction of groundwater flow is mainly restricted by the variable hydraulic gradients from locality to another.

Twenty-three groundwater samples were collected and chemically analysed. Groundwater salinity of basement aquifer varies from 438 mg/l to 10409 mg/l, reflecting a wide variation in groundwater quality from fresh to saline. The groundwater quality of Nubia sandstone aquifer varies from fresh to brackish, where the salinity ranges from 459 mg/l to 1292 mg/l. In basement aquifer, the type Cl-Na is dominant, while in Nubia sandstone aquifer, HCO3-Na and Cl-Na water types are recognized. In basement aquifer, the groundwater is mostly characterized by permanent hardness (except Nos. 1, 6 & 13 have a perfect temperary hardness). In Nubia sandstone aquifer, the groundwater is mainly characterized by temporary hardness. In basement groundwater, Cl is the most correlated anion with salinity (R-2 = 0.9615), and Na is the most correlated cation with salinity (R-2=0.9153). In Nubia sandstone groundwater, SO4 is the most correlated anion with salinity (W = 0.7573) and Na is the most correlated cation with salinity (R-2 = 0.8578). Groundwater quality was evaluated for different uses and some recommendations were given.