Simulation of Groundwater Mound Resulting from Proposed Artificial Recharge of Treated Sewage Effluent Case study – Gaza waste water treatment plant, Palestine

Mounding of the groundwater table beneath recharge sources is of concern as the raised water table approaches closely to near-surface facilities or features. The shape and height of the mound depend on several factors including the recharge rate, hydraulic conductivity and thickness of the aquifer. The objective of this paper is to evaluate the suitability of the study area for a rapid infiltration system of treated wastewater effluent without causing excessive mounding of the water table. A comparison was made between two methods used to estimate ground-water mounding: an analytical approach and a numerical approach. Both approaches incorporate each of the saturated and the unsaturated zones. Results predicted that after 1400 days of groundwater level simulation, the maximum rise of the mound was 18 m in the center of the infiltration pond, and it was almost 17 m at the edges of the pond. As the natural average groundwater level was about 35 m deep in the area of the study, the groundwater mounding caused no problem on the groundwater level. Thus, the planned infiltration was feasible.