Prevention of groundwater contamination in the Tagus basin through the application of a data driven ARMA tool based on a series of monitoring wells

This study aims to raise awareness of the need to adapt WWTPs procedures for the removal of Contaminants of Emerging Concern (CECs) by adopting quaternary treatment techniques, bringing them into line with the current EU legislation (mainly UWWTD 2024/3019 and DWD 2020/2184), to guarantee safe reuse of this water for artificial recharge, as envisaged by MAR2PROTECT project. A preliminary investigation on the hydrogeological and hydro-chemical characteristics of the Central and Southern sectors of the aquifer systems in the Left Bank of the Tagus-Sado Basin (Portugal, Iberian Peninsula) was conducted, with the goal of implementing a water quality modelling framework to enhance the understanding of contaminant migration within the aquifer. The tool adopts a stationary Gaussian Process model to address for the limited data availability in the region. Its application has proven that data-driven statistical models, as well as physic-aware models for transport dynamics, have the potential to assess the positive impact of wastewater treatment on groundwater quality.