TY - JOUR
T1 - The effect of pumping saline groundwater for desalination on the fresh–saline water interface dynamics
AU - Stein, Shaked
AU - Yechieli, Yoseph
AU - Shalev, Eyal
AU - Kasher, Roni
AU - Sivan, Orit
N1 - Funding Information:
We would like first to thank and honor Mr. Haim Hemo from the Geological Survey of Israel (GSI) who passed away on October 2018 and was one of the corner stone in all the field work of the coastal aquifer in Israel. We also thank Mr. Hallel Lutzky from the GSI for suppling crucial equipment. We thank Dr. Clifford Voss from the USGS and Prof. Alex Yakirevich from Ben Gurion University of the Negev for their assistance with the numerical model. We thank also MIKE powered by DHI for providing a student license for the FEFLOW software. The research was partially funded by the Mediterranean Sea Research Center of Israel and part of the initial study was funded by the Israeli Water Authority. We thank the Rieger foundation -JNF for their generous support (S.S).
Publisher Copyright:
© 2019
PY - 2019/6/1
Y1 - 2019/6/1
N2 - Over the past few decades, seawater desalination has become a necessity for freshwater supply in many countries worldwide, particularly in arid and semi-arid regions. One potentially high-quality feed water for desalination is saline groundwater (SGW) from coastal aquifers, which has lower fouling propensity than seawater. This study examines the effect of pumping SGW from a phreatic coastal aquifer on fresh groundwater, particularly on the dynamics of the fresh–saline water interface (FSI). Initially, we constructed a 3D finite-element model of a phreatic coastal aquifer by using the FEFLOW software, which solves the coupled variable density groundwater flow and solute transport equations. Then, we compared and validated the results of the model to those of a field-scale pumping test. The model indicates that pumping SGW from a coastal aquifer freshens the aquifer and rehabilitates parts that were salinized due to seawater intrusion – an effect that increases with increasing pumping rate. In addition, when simultaneously pumping fresh groundwater further inland and SGW from below the FSI, the freshening effect is less pronounced and the salinity of the aquifer is more stable. In line with the results of the model, the field experiment revealed that salinity in the observation well decreases over the course of pumping. Taken together, our findings demonstrate that, in addition to providing a high-quality source feed water for desalination, pumping SGW does not salinize the aquifer and even rehabilitates it by negating the effect of seawater intrusion. These findings are important for planning shoreline desalination facilities and for managing arid coastal regions with lack of water supply and over exploited aquifers.
AB - Over the past few decades, seawater desalination has become a necessity for freshwater supply in many countries worldwide, particularly in arid and semi-arid regions. One potentially high-quality feed water for desalination is saline groundwater (SGW) from coastal aquifers, which has lower fouling propensity than seawater. This study examines the effect of pumping SGW from a phreatic coastal aquifer on fresh groundwater, particularly on the dynamics of the fresh–saline water interface (FSI). Initially, we constructed a 3D finite-element model of a phreatic coastal aquifer by using the FEFLOW software, which solves the coupled variable density groundwater flow and solute transport equations. Then, we compared and validated the results of the model to those of a field-scale pumping test. The model indicates that pumping SGW from a coastal aquifer freshens the aquifer and rehabilitates parts that were salinized due to seawater intrusion – an effect that increases with increasing pumping rate. In addition, when simultaneously pumping fresh groundwater further inland and SGW from below the FSI, the freshening effect is less pronounced and the salinity of the aquifer is more stable. In line with the results of the model, the field experiment revealed that salinity in the observation well decreases over the course of pumping. Taken together, our findings demonstrate that, in addition to providing a high-quality source feed water for desalination, pumping SGW does not salinize the aquifer and even rehabilitates it by negating the effect of seawater intrusion. These findings are important for planning shoreline desalination facilities and for managing arid coastal regions with lack of water supply and over exploited aquifers.
KW - Coastal aquifers management
KW - Desalination
KW - Saline groundwater
KW - Seawater intrusion
UR - http://www.scopus.com/inward/record.url?scp=85063353489&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2019.03.003
DO - 10.1016/j.watres.2019.03.003
M3 - Article
C2 - 30904710
AN - SCOPUS:85063353489
VL - 156
SP - 46
EP - 57
JO - Water Research
JF - Water Research
SN - 0043-1354
ER -