TRENDS IN THE BIOGEOCHEMISTRY OF GROUNDWATER IN THE AGRO-INDUSTRIAL REGION IN NORTHEAST YUCATAN

Abstract

Background: The state of Yucatan has a significant amount of groundwater, but it is vulnerable to pollution due to agro-industrial contamination given the characteristics of thin soil and calcareous rocks that allow rapid infiltration of water, making easy for dissolved substances to reach the aquifer. The agro-industrial activities in the northeast of the peninsula of Yucatán promote changes in the geochemistry of groundwater in the region. Objective: Hereby, we present the observed changes in the geochemistry of groundwater by comparing three years of groundwater measurements from the agroindustrial area of Yucatan. Methodology: We measured physicochemical parameters, nutrients and ions during three years (2017 - 2019) in 14 wells of the municipalities of Sucilá, Panabá and Tizimín (east Yucatán). Results: Our results of three years show that ammonium, sulfate, chloride and calcium had an increasing trend; whereas nitrate and phosphate show a slight decrease. The agronomic indices SAR, CROSSf and RSC were evaluated to identify risk of sodification or alkalinization of the soil for irrigation. The water-rock interaction imparts special characteristics to groundwater that should be considered for its use in irrigation. Implications. This research updates information on the quality of water for irrigation and provides useful agronomic indices for better agro-industrial practices in the northeast region of Yucatán. Conclusion: The grouping of wells did not completely respond to the spatial location; rather, it might be a combination of seasonal effects, livestock, animal feeding operations and the use of manure and fertilizers, among others. With this research, we propose to establish the groundwater monitoring of the agro-industrial region of the northeast of Yucatan in the medium (5-10 years) and long term (> 20 years).