Water quality in the central zone of the Texcoco aquifer, Mexico

Resumen

Objective: To determine water quality in the central zone of the Texcoco aquifer, Mexico, for human use and consumption and agricultural use.

Methodology: The physical, chemical, and biological indicators of the water from 16 wells in urban areas of the central zone of the aquifer were determined. The sampling was carried out, based on the parameters and definition of water quality per use established in the current official Mexican standards.

Results: According to the physical indicators and concentrations of CO₃^2-, HCO₃^-, Ca²⁺, Mg²⁺, Cl^-, SO₄^2-, PO₄^3-, Na⁺, K⁺, Fe, Cu, and Zn, the water in the sample was suitable for human use and consumption and agricultural use. Based on the cadmium (Cd) concentration, the water was unsuitable for human use and consumption and agricultural use, in 12 and 6 wells, respectively. According to the lead (Pb) concentration, water was suitable for agricultural use in the 16 wells studied; however, it was unsuitable for human use and consumption in any of the wells. In eight wells analyzed, the presence of fecal coliforms was lower than the permissible limit for agricultural use.

Implications: This study complements researches done in other areas of the aquifer. The causes of water pollution are unknown and researches about the vulnerability of the aquifer and the possible polluting sources should be carried out.

Conclusions: The water from the aquifer in the central zone has limitations for human use and consumption and agricultural use, as a consequence of the high Cd and Pb concentrations and its microbiological quality.