Identification and quantification of leakage into the carbonate aquifer by using non- isotopic environmental tracers and hydro-chemical modeling

Abstract

Groundwater transfer estimation between aquifers and aquitards is essential for water resources management. While artificial tracer application is in most cases not regionally feasible, natural tracer utilization can supply the required regional groundwater transfer delineation. A Paleocene-Eocene thermal episode caused an anomaly of barium and silica concentrations in the Eocene aquitard that are used as natural tracers for the identification and quantification of leakage into the Turonian aquifer through the Senonian aquiclude. The leakage was found to be concentrated in the vicinity of the Menashe syncline north of the Yarkon-Taninim basin, which is the main source of the underground groundwater supply in Israel. The two tracers indicated leakage volume balance estimations of more than 3.8*106 m3 yr-1 and 18.9*106 m3 yr-1, which correspond to the PHREEQC hydro-chemical modeling results. The leakage salinity was assessed to be low; therefore, it will not damage the high-quality groundwater in the Turonian aquifer that is exploited for the potable water supply.