Groundwater quality assessment in the La Mojana region of northern Colombia: implications for consumption, irrigation, and human health risks.

Water quality is one of the most relevant issues related to water management, with water pollution and access to clean water for drinking and irrigation being common issues in developing countries. Groundwater is an available water source, especially where surface sources are scarce or unsuitable. In this sense, studies to improve knowledge of aquifers should be undertaken where information on groundwater resources is not available. In the current study, 50 groundwater samples were collected from rural and urban wells used by local communities for human consumption and to irrigate local crops. Several indices for drinking water and irrigation use have been used for the assessment of water quality. Conversely, the carcinogenic and noncarcinogenic human health risks due to exposure to heavy metals in the groundwater were estimated, as were the predominant hydrochemical characteristics. The groundwater water quality index (GWQI) shows values < 100 for all the samples; groundwater is recommended for drinking after disinfection. By contrast, the irrigation water quality index (IWQI) shows that 80% of groundwater samples pose a potential threat to irrigation, with restriction categories ranging from high to severe. The individual hazard quotients were < 1. However, the multielement and multipathway hazard index (HI) for children and adults were > 1, whereas As and Mn had a higher contribution to the HI. The Piper trilinear diagram shows that hydrochemical facies of Ca²⁺ and HCO₃⁻ are significantly dominant. By contrast, weathering of rocks and atmospheric precipitation is the dominant factors regulating the chemistry of groundwater in the aquifer system of La Mojana. Our findings indicate that there are significant potential noncarcinogenic health risks for local populations exposed to groundwater. [ABSTRACT FROM AUTHOR]