INFILTRATION CONSIDERATIONS FOR GROUND-WATER RECHARGE WITH WASTE EFFLUENT

Water reuse and ground-water recharge can be used to meet the growing demands for water, particularly in arid regions. Ground-water recharge using fresh water or treated wastewater is most often accomplished by infiltration from surface basins. The water percolates through the unsaturated soil region to an underlying aquifer for storage and future use. In the case of wastewater, additional treatment occurs as the effluent flows through the soil. The system hydraulics of recharge basins have been examined through a combination of field and laboratory investigations. These studies indicate that infiltration rates and soil aquifer treatment of wastewater are influenced by soil type and soil profile characteristics, surface clogging material, pond depth, and wetting/drying cycle times. The surface-clogging layer was found to be susceptible to consolidation and to associated reduction in hydraulic conductivity under seepage forces.