Groundwater quality assessment for human consumption. A case study of the Middle Magdalena Valley – Colombia.

Water quality is one of the major causes affecting human health, especially in vulnerable populations in developing countries. In Colombia, groundwater is often consumed by rural populations as drinking water without any treatment. Therefore, a groundwater quality assessment in the Middle Magdalena Valley in Colombia (MMV) was conducted to determine potential health hazards associated with its consumption. The study area covers approximately 8500 km2 and is bounded by the piedmont of the San Lucas Mountain range and the Central and Eastern Mountain Ranges of the Andes.

In this study, 458 water samples were analyzed. They were collected during three (3) field campaigns conducted between February 2020 and March 2021, encompassing contrasting hydrologic periods. Based on laboratory results, the potential health hazards associated with groundwater consumption were assessed using the Colombian Water Quality Risk Index (CDQRI-IRCA).

CDQRI-IRCA values in the MMV ranged from 0 to 80, with a mean of 51 and a standard deviation of 21. Furthermore, more than 84% of the analyzed samples were classified as high risk for human consumption. This outcome is associated with the presence of fecal and total coliforms in 58% and 89% of the analyzed samples, respectively. These parameters hold the highest specific weights in the CDQRI-IRCA calculation.

The presence of fecal and total coliforms in groundwater in the MMV is associated with deficiencies in sanitation coverage, particularly in rural areas where water supply wells are often located near septic tanks, handmade pit latrines without proper hygienic protection, or in areas with backyard livestock farming.

 

Acknowledgments

The researcher thanks the MEGIA Research Project, Contingent Recovery Contract FP44842-157-2018 funded by Minciencias and the National Hydrocarbons Agency