Groundwater hydrology and characteristics of the tertiary aquifers, Northwest Cairo, Egypt

The study area lies to the northwest of Cairo at Km.34 (Cairo – Alexandria Desert Highway) between latitudes 30° 00' 00" N & 30° 10' 00" N and longitudes 30° 50' 00" E & 31° 10' 35" E.  It attains an area of about 590 Km. The main objective of the present work is to focus on the configuration and assessment of groundwater potentials of the Tertiary aquifers including the Lower Miocene (Moghra Formation), Oligocene and Eocene limestone. These aquifers are considered as moderately productive where their transmissivity values are (197.5 &1352), 92.9 and 150 m/day and their specific capacity are (5.9 & 12.7), 7.6 and 5.2 m/h/m, for the Miocene, Oligocene and Eocene aquifers, respectively. The general flow direction of the groundwater is from east to west and from southeast to northwest with some local changes which may be attributed to the over-exploitation at these locations.  The ranges of the water salinities of these aquifers are 288-3776, 2000-3100 and 2715-13120 mg/l for the Miocene, Oligocene and Eocene aquifers, respectively. The inferred faults play an important role in the direct hydraulic connection between the three aquifers.