Panagiotou, C.F., Karaolia, P., Stefan, C., Papanastasiou, P., Sprenger, C. (2021) 
Quantitative microbial risk analysis (QMRA) for setting health-based performance targets during soil-aquifer treatment: application to the Ezousa site in Cyprus. Presentation at the 48th Congress of the International Association of Hydrogeologists. Brussels, Belgium, 6-10 September 2021


The need to implement novel and environmentally sustainable technologies to mitigate water-related issues, such as escalating population growth and contamination of water sources, has become noticeable on a global scale. An elegant option to address these issues is to apply Manage Aquifer Recharge (MAR) schemes. These schemes are processes that intentionally recharge water into aquifers for future recovery or environmental benefits.

The MAR site of Ezousa, located at the south-western part of Cyprus, has been operational since 2003 based on Soil Aquifer Treatment (SAT) with the aim of providing a water supply mainly for irrigation purposes. Due to the semi-arid conditions and the groundwater overexploitation though, Ezousa MAR system is vulnerable to specific hazards, such as seawater intrusion and nitrate pollution due to intense agricultural activities.

An efficient way to evaluate these risks is by using numerical models to predict the response of the system under different conditions. Moreover, recent technological advancements in terms of computational capacity and internet accessibility have pushed towards the development of web-based tools for optimizing water resource management. These tools possess a number of advantages compared to conventional, desktop-based tools, such as locations and device independence, easy maintenance, as well as resource pooling. One such example is the INOWAS platform, which is a free web-service that focuses on groundwater-related issues. Particularly, this platform contains various analytical and numerical tools that can be used to improve the management and operation of groundwater systems, especially with relation to MAR. Accordingly, the present study focuses on using INOWAS platform for the development of a numerical groundwater flow model and its evaluation under different scenarios to assess the Ezousa aquifer.

Steady computations are first performed to calibrate the aquifer hydraulic properties (e.g. the spatial distribution of hydraulic conductivity) prior to the installation of the MAR facility in the aquifer. As a second step, a transient flow model for the period 2014-2018 was setup to analyze the impact of the MAR system on the groundwater flow system. Subsequently, the influence of increased water demand due to the agricultural development of the region as well as reduced water availability caused by climate change is analysed through the simulation of various scenarios.

Preliminary results suggest that the web-based INOWAS tools are helpful to evaluate the influence of MAR on the local groundwater system under different scenarios.