EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Hydrogeological, hydrodynamic and anthropogenic factors affecting the spread of pharmaceuticals and pesticides in water resources of the Granada plain (Southern Spain)

Marta Inés Llamas1, Pablo Jiménez-Gavilán1, Juan Antonio Luque-Espinar2, José Benavente-Herrera3, Lucila Candela4, Mónica Sanmiguel-Martí5, Javier Rambla-Nebot5, José Luis Aranda-Mares5, and Iñaki Vadillo-Pérez1
Marta Inés Llamas et al.
  • 1Group of Hydrogeology, Faculty of Sciences, University of Malaga, Malaga, Spain
  • 2Department of Water and Global Change, IGME-CSIC, Urb. Alcázar del Genil, 4-Edif. Zulema, 18006 Granada, Spain
  • 3Water Research Institute and Department of Geodynamics, University of Granada, 18071 Granada, Spain
  • 4IMDEA-Water, 28805 Alcalá de Henares and IUACA, 03690 Alicante, Spain
  • 5IPROMA S.L. Camino de la Raya, 34. Castellón, Spain

The anthropogenic organic contaminants contemplated in the environmental legislation, as well as those of emerging concern, threaten the quality of water resources to a degree that remains largely unknown. Contaminant exposure in the aquatic environment is a crucial element if a full understanding of the risk is pursued. There are still many uncertainties about the occurrence of organic contaminants and their behavior in the hydro(geo)logical media in large scale areas. The case study of the unconfined aquifer of the Granada Plain (approximately 200 km2) is presented here. Two groundwater and surface water monitoring campaigns were conducted (March 2017 and June 2018). Water samples were analysed for (i) 171 organic contaminants (e.g., pesticides, pharmaceuticals, drugs of abuse, PAHs); (ii) major and minor ions (Ca2+, Mg2+, Na+, K+, Cl-, SO42-, HCO3-, NO3-) and (iii) isotopes of the water molecule (δ18O, δ2H) and δ13C from the dissolved inorganic carbon. Additionally, in situ measurements of physico-chemical parameters (pH, temperature, electrical conductivity, redox potential and dissolved oxygen) were carried out. In total, 41 organic pollutants were detected, at least once: 17 pharmaceuticals or drugs of abuse, 21 pesticides or their metabolites and three PAHs. Statistical tests confirmed the significance of seasonal changes for some of these parameters (e.g., EC, Cl-, F-, δ18O, δ13C), revealing the influence from snowmelt water input on streams and the intensification of irrigation. In March 2017, the group of pesticides (largely represented by triazines) predominated, whereas the frequency of detection of pharmaceuticals increased substantially in June 2018. Based on the obtained results, a qualitative evaluation has been made to suggest four main factors affecting the spatial and seasonal variation of organic pollutants in the aquifer: (i) the variation of the unsaturated zone thickness; (ii) the river-groundwater hydraulic connection; (iii) the hydraulic gradient; and (iv) the anthropogenic factor determining the period of contaminant release throughout the year and wastewater management practices. The river-groundwater hydraulic connection can be especially important in the case of those contaminants whose main path of entry into the aquatic environment occurs through wastewater discharge into streams (i.e., pharmaceuticals).

How to cite: Llamas, M. I., Jiménez-Gavilán, P., Luque-Espinar, J. A., Benavente-Herrera, J., Candela, L., Sanmiguel-Martí, M., Rambla-Nebot, J., Aranda-Mares, J. L., and Vadillo-Pérez, I.: Hydrogeological, hydrodynamic and anthropogenic factors affecting the spread of pharmaceuticals and pesticides in water resources of the Granada plain (Southern Spain), EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-15414,, 2023.