The studied area represents a part of W. El Farigh, where the Lower Miocene aquifer is well represented and the groundwater plays an essential role for satisfying water demands. During the last few years, a sudden increase in the demand for irrigation water has been arisen due to intensification of cultivation. The people have now over-pumping the aquifer to meet water requirements.
Results indicate that excessive withdrawals of groundwater from wells can create a large drawdown, due to increasing of well and aquifer losses, consequently decreasing of the specific capacities and efficiencies of such wells. Besides, decline of well yields and the pumping costs will increase. Although the regional aquifer system may be in equilibrium and capable of satisfying the rate of production, the head declines in the vicinity of the over-pumped well and cause local movements toward it.
The hydrogeochemical studies reveal the presence of NaHCO3 water type at the majority of the studied area and represent the best places for water supply. The presence of MgCl2 and CaCl2 water types in some wells indicates mixing of meteoric water with marine water, due to local effects. The hydrochemical coefficients (rNa/rCl & rCl/rCO3+HCO3) indicate the presence of local saltwater problems at some localities. Possible sources of saltwater enrichment in the Lower Miocene aquifer are either from the leaching processes of fresh water to the lagoonal salty deposits of El Raml Member (Base of El Moghra Formation) or due to upward-leakage of old marine water along fault planes. Generally, the groundwater in the studied area is suitable for drinking and irrigation purposes, except of some wells suffering from high salinity water. Therefore, reduction of groundwater withdrawal from such wells is recommended.
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