A risk assessment methodology to evaluate the risk failure of managed aquifer recharge in the Mediterranean Basin

Abstract

Abstract. Managed aquifer recharge (MAR) can be affected by many risks. Those risks are related to different technical and non-technical aspects of recharge, like water availability, water quality, legislation, social issues, etc. Many other works have acknowledged risks of this nature theoretically; however, their quantification and definition has not been developed. In this study, the risk definition and quantification has been performed by means of "fault trees" and probabilistic risk assessment (PRA). We defined a fault tree with 65 basic events applicable to the operation phase. After that, we have applied this methodology to six different managed aquifer recharge sites located in the Mediterranean Basin (Portugal, Spain, Italy, Malta, and Israel). The probabilities of the basic events were defined by expert criteria, based on the knowledge of the different managers of the facilities. From that, we conclude that in all sites, the perception of the expert criteria of the non-technical aspects were as much or even more important than the technical aspects. Regarding the risk results, we observe that the total risk in three of the six sites was equal to or above 0.90. That would mean that the MAR facilities have a risk of failure equal to or higher than 90 % in the period of 2-6 years. The other three sites presented lower risks (75, 29, and 18 % for Malta, Menashe, and Serchio, respectively).

Managed aquifer recharge with reverse-osmosis desalinated seawater: modeling the spreading in groundwater using stable water isotopes

“…Here [X] w is the (calculated) ion concentration in the well, [X] DSW is the ion concentration in the DSW and [X] i is the initial ion concentration (background) in the well. Diversion of the observed concentration from the calculated concentration can give insight to the sediment-water reaction (e.g., Ganot et al, 2018;Ronen-Eliraz et al, 2017;Stuyfzand et al, 2017).…”

“…In Israel, for example, DSW reached 66 % of the domestic and industrial fresh water supply in 2017 (Israel Water Authority, 2018). This growing use of DSW affects downstream water systems such as reservoirs (Ronen-Eliraz et al, 2017;Negev et al, 2017;Stuyfzand et al, 2017;Ganot et al, 2017Ganot et al, , 2018, wastewater treatment plants (Lahav et al, 2010;Negev et al, 2017) and agricultural irrigation (Lahav et al, 2010;Yermiyahu et al, 2007). One direct way by which DSW use affects the water budget is managed aquifer recharge (MAR).…”

“…Excess DSW produced in Israel due to operational constraints made it an attractive alternative source for MAR, raising the need to understand its effect. While the relatively rapid hydrological and geochemical processes (timescales of hours to weeks) of this new MAR activity were recently monitored and modeled (Ganot et al, 2017(Ganot et al, , 2018Ronen-Eliraz et al, 2017), the potential long-term (months to decades) impact of this process on the natural aquifer is still unknown, lacking observations and quantitative studies.…”

“…The DSW is regularly supplied directly to consumers through the centralized national water system. Periodically, operational constraints, such as maintenance of the national system, prohibit distribution of the DSW; limited reservoir capacity makes storage of this expensive surplus of DSW in the aquifer through MAR operations the only feasible solution (Ganot et al, 2017(Ganot et al, , 2018Ronen-Eliraz et al, 2017).…”

Managed aquifer recharge with reverse-osmosis desalinated seawater: modeling the spreading in groundwater using stable water isotopes

“…One direct way by which DSW use affects the water budget is Managed Aquifer Recharge (MAR). MAR using different water sources has been practiced for over 5 decades as part of the integrated water resource management of Israel (Dreizin et al, 2008;Gvirtzman, 2002), and is becoming a major component of water management in many Mediterranean countries (Rodríguez-Escales et al, 2018).…”