Integrated socio-hydrogeological approach to tackle nitrate contamination in groundwater resources. The case of Grombalia Basin (Tunisia)

V Re; E Sacchi; S Kammoun; C Tringali; R Trabelsi; K Zouari; S Daniele

doi:10.1016/j.scitotenv.2017.03.151

Integrated socio-hydrogeological approach to tackle nitrate contamination in groundwater resources. The case of Grombalia Basin (Tunisia)

Sci Total Environ. 2017 Sep 1:593-594:664-676. doi: 10.1016/j.scitotenv.2017.03.151. Epub 2017 Mar 28.

Authors

V Re¹, E Sacchi², S Kammoun³, C Tringali⁴, R Trabelsi³, K Zouari³, S Daniele⁴

Affiliations

¹ Laboratory of Radio-Analyses and Environment, National School of Engineers of Sfax, BP1173, 3038 Sfax, Tunisia; Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Via Torino 155, 30172 Mestre-Venezia, Italy. Electronic address: re@unive.it.
² Department of Earth and Environmental Sciences, University of Pavia, Via Ferrata 1, 27100 Pavia, Italy.
³ Laboratory of Radio-Analyses and Environment, National School of Engineers of Sfax, BP1173, 3038 Sfax, Tunisia.
⁴ Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Via Torino 155, 30172 Mestre-Venezia, Italy.

PMID: 28363179
DOI: 10.1016/j.scitotenv.2017.03.151

Abstract

Nitrate contamination still remains one of the main groundwater quality issues in several aquifers worldwide, despite the perduring efforts of the international scientific community to effectively tackle this problem. The classical hydrogeological and isotopic investigations are obviously of paramount importance for the characterization of contaminant sources, but are clearly not sufficient for the correct and long-term protection of groundwater resources. This paper aims at demonstrating the effectiveness of the socio-hydrogeological approach as the best tool to tackle groundwater quality issues, while contributing bridging the gap between science and society. An integrated survey, including land use, hydrochemical (physicochemical parameters and major ions) and isotopic (δ¹⁵N_NO3 and δ¹⁸O_NO3) analyses, coupled to capacity building and participatory activities was carried out to correctly attribute the nitrate origin in groundwater from the Grombalia Basin (North Tunisia), a region where only synthetic fertilizers have been generally identified as the main source of such pollution. Results demonstrates that the basin is characterized by high nitrate concentrations, often exceeding the statutory limits for drinking water, in both the shallow and deep aquifers, whereas sources are associated to both agricultural and urban activities. The public participation of local actors proved to be a fundamental element for the development of the hydrogeological investigation, as it permitted to obtain relevant information to support data interpretation, and eventually guaranteed the correct assessment of contaminant sources in the studied area. In addition, such activity, if adequately transferred to regulators, will ensure the effective adoption of management practices based on the research outcomes and tailored on the real needs of the local population, proving the added value to include it in any integrated investigation.

Keywords: Aquifer pollution; Isotopes; Public engagement; Socio-hydrogeology; Stakeholder analysis.