Abstract: In order to identify the origin of the salinity and formation of saline plumes in the central part of the Mediterranean coastal aquifer of Israel, we determined the elemental and boron, strontium, and oxygen isotopic compositions of fresh and brackish groundwater (C1 up to 1500 mg/L). We distinguish between two key anthropogenic sources: (1) sewage effluents used for irrigation with high Na/C1, SO4/C1, and B/C1 ratios and low Br/C1 ratios relative to seawater ratios, low ;5•B values (0-10%o) and high ;5•80 values (>-4%0); and (2) imported water from the Sea of Galilee that is artificially
recharged tothe aquifer with high Br/C1 (3 x 10 -3) and ;5•80 values (-1%o) and a low 87Sr/86Sr ratio of 0.70753. The brackish groundwater from the saline plumes have relatively low Na/C1 ratios (0.5-0.8) and high Ca/Mg, Mg/C1, and Ca/(SO 4 q- HCO3) (> l) ratios relative to seawater ratios; marine SO4/C1 and Br/C1 ratios;5•B values of 24.8-49.9%0; 18 87 86 ;50 of -2.95%0 to -4.73%0; and Sr/ Sr ratios of 0.708275-0.708532. The composition of most of the investigated groundwater from the saline plumes differs from those of the 87 86 anthropogenic sources, imported water, fresh uncontaminated groundwater (Sr/ Sr of 0.70866, ;5•B of 20-30%o), and saline water from the adjacent Eocene aquitard. Only in ß 18 areas of artificial recharge does local groundwater have high Br/C1 and ;50 values that are typical to the Sea of Galilee. The linear relationships between chloride and most of the ions, including Band Sr, the relatively high ;5•B (>30%0) and low ;5•80 (<-4%0) values, and the chemical signature of the saline plumes (e.g., marine Br/C1 and SO4/C1 ratios), suggest that (1) mixing processes control the chemical composition of the brackish water within the aquifer, and (2) the saline postulated end-member has a chemical composition that resembles modified seawater with a marine and higher ;5•B values, and a 87Sr/86Sr ratio of <0.7083. We propose that most of the salinization phenomena and the formation of saline plumes in the inner parts of the coastal aquifer are derived from upconing of underlying natural saline water bodies and enhanced by overexploitation and draw-down of the overlying fresh groundwater.

Abstract: It has been suggested in a number of historical notes that it was neither Willem Badon Ghijben nor Alexander Herzberg who formulated the famous principle now carrying their name, which relates the water-table elevation to the depth of the freshwater saltwater interface in coastal aquifers. In this paper, a systematic review of the literature pre-dating the publication of their work is presented. The aim is to establish to what extent these previous works captured the essence of the Ghijben-Herzberg principle, that is, the combination of a correct conceptual model of the hydrogeological conditions with a quantitative relationship. It was found that references to coastal fresh groundwater reserves can be traced back to Roman times, while the earliest detailed descriptions of a freshwater lens that could be found dates from the eighteenth century. The correct understanding of the hydrostatic equilibrium between fresh and salt groundwater is evident in works from the early nineteenth century. However, it was Badon Ghijben and Herzberg who combined this with the correct understanding of the groundwater conditions of a freshwater lens. It was further found that Herzberg had already recorded his findings in 1888 in a hand-written report, confirming speculation that such a report might exist.