On the distribution of saline groundwater in the Poopó Basin, Central Bolivian Highland
Lake Poopó is a terminal lake of the Bolivian Altiplano, with high salinity and heavy anthropogenic pollution from centuries of extensive mining activity. This study aims to describe how the water quality of groundwater and surface water system in different subwater-sheds of the Lake Poopó varies with geology and hydrology. Measurements of total dissolved solids (TDS) in wells show groundwater becoming more saline close to the lake. The results indicate high natural contamination from weathering of minerals with high concentrations of lead and arsenic, generally dry conditions which results in high salinity in water and soil, and most importantly,
anthropogenic contamination from the intensive mining and metallurgic activities. Fresh roundwater can be found in the upper part of the soil and bedrock to a small extent. Up-coning and saline water intrusion is very common in the wells, which need to be shallow in order to avoid abstraction of saline groundwater. The groundwater is highly vulnerable and further on contaminated by acid mine drainage from the mining tails and by untreated effluents from the towns and villages of the area.