Abstract
The influence of the chemical water composition over water quality has been barely studied in the Andes. Condoriri River basin is located in the Royal Range of the Andes and provides drinking water to millions of people from La Paz and El Alto, the two major cities in Bolivia. The purpose of this study is to investigate the effects of nutrients and major ions composition over water quality formation during two different seasons, in order to determine the influence of glacier melting and the weathering of rocks. Field measurements were done during the dry and the wet season for the determination of physicochemical parameters and the water analysis for organic carbon, nutrients, and major ions. All water samples were slightly alkaline with pH average values of 7.99 and 7.85 in both seasons. Major ions have shown spatial variations, SO42- and Ca2+ had higher concentrations at the effluent water from the glacier. Source of major ions was identified as silicate, carbonate and sulphate weathering from rocks like gypsum.
