Role of agricultural land practices in the behaviour of nitrates in groundwater

Nitrate contamination is a major issue in aquifers that are being exploited for drinking water. Exceeding maximum contamination levels (MCL) of nitrates in drinking water can cause acute and chronic health problems. In agricultural areas, aquifers are vulnerable to nitrate contamination due to the excessive use of fertiliser. This research study investigated the potential impacts of anthropogenic nitrates on the giant Guarani Aquifer System (GAS) in Brazil, where nitrogen-based fertiliser use had doubled from 2005 to 2016. The study results indicated that there exists two different systems for the behaviour of nitrates in groundwater, above and below a 150 m depth of the aquifer. For the aquifer depth above 150 m, Cl− (positive influence) and F− (negative influence) were found to significantly influence NO3− contamination (p