ABSTRACT
Treated wastewater effluents in Oman are used primarily for landscape irrigation. However, during the last few years, a relatively new application of such effluents was applied in south of Oman (Salalah coastal strip) where the treated effluents were used to recharge groundwater aquifers along a 14 km recharge line. The recharge line contains 44 wells to recharge about 20,000 m3/d of treated effluents to the groundwater. This study was carried out to understand the groundwater quality in Salalah coastal strip and its suitability for different purposes since groundwater is a major source for agricultural, domestic and livestock purposes in the study region. The study involved extensive groundwater sampling from the monitoring wells for a period of approximately one year. The analysis involved inorganic (anions and cations) parameters, biological (bacteria, Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD)) parameters, and Total Petroleum Hydrocarbon (TPH) of the collected samples from the monitoring wells.
Furthermore, a dynamic model, showing the impacts of treated water injection in the groundwater of aquifers for Total Dissolved Solids (TDS), Kitrate (NO3) and water level was developed. The model was simulated for steady state and transient state conditions. The model simulations provided information concerning predevelopment hydrologic conditions and aquifer response to changes in pumpage and recharge through time. Simulations were made using the three-dimensional finite-difference ground-water flow model (MODFLOW) and transport model (MT3D).
