The use of wastewater in Cochabamba, Bolivia: A degrading environment

In Cochabamba, Bolivia, wastewater is extensively used in urban and peri-urban agriculture. Both vegetable and fodder crops are irrigated with polluted water, i.e. diluted or partly treated municipal and industrial sewage containing high concentrations of pathogens, heavy metals and salts. Specifically in the downstream La Mayca area, where the farmers have an agreement with the municipal water and sewerage company, soil degradation has forced farmers to increasingly replace vegetable crops with more salt-tolerant fodder crops. In other areas around the city, cultivators deny using readily available wastewater, pointing to nearby wells as their water source. However, many wells are probably also polluted and do not yield enough water for the irrigated area served. Farmers state they are not confronted with specific health problems related to the use of polluted water, contradicting reports from local health workers. Low surface water flows and low rainfall, along with high (industrial) pollution and low wastewater treatment capacity mean that most of the water available to the farmers is of poor quality. Reduction of (industrial) pollution, increased treatment capacity and an integrated water management (IWM) approach, in which nearby good-quality groundwater could be used as a water source for blending with wastewater, represent options for improvement. However, strong traditional water rights, lack of urban planning, and weak institutions are constraints to the improvement of wastewater management in Cochabamba.