Assessment of groundwater pollution hazard in agricultural areas EVALUACIÓN DEL PELIGRO DE CONTAMINACIÓN DEL AGUA SUBTERRÁNEA EN ÁREAS AGRÍCOLAS

GRONDONA, SEBASTIÁN; MASSONE, HÉCTOR; GONZALEZ, MARIANA; BEDMAR, FRANCISCO

REVISTA INTERNACIONAL DE CONTAMINACIóN AMBIENTAL

CENTRO CIENCIAS ATMOSFERA UNAM

Año: 2021 vol. 38 p. 111 - 125

0188-4999

This work evaluates the groundwater contamination hazard associated with the use of pesticides, considering their properties, the soil where they are applied and the aquifer to which they can potentially leach. The study area considered was the Quequén Grande River basin where the only water supply is the Pampeano aquifer and agriculture is the dominant activity. The contamination hazard was obtained by combining the aquifer vulnerability (DRASTIC index) and the potential pollutant load (AFT index) working whit ARCGIS software. The sectors with the least vulnerability were in the upper zone of the watershed and those with the greatest vulnerability in the lower zone. Five pesticides were classified with a category higher than “unlikely leaching”, obtaining the highest potential pollutant loads in the upper sector. Two hazard maps were obtained. In both, the least hazard areas are located in the north-east, where the water table is deeper, and the percentage of organic matter is higher. The areas of greatest hazard are in the west and southeast due to the shallow water level, lower content of organic matter, and low thickness of the A horizon. These maps obtained can then be used in groundwater management: if the contaminant load is low, the use of the maps obtained according to the AFT index is considered sufficient. On the contrary, in those cases where the load is greater, the use of hazard maps should be considered.