The use of Scirpus californicus wetlands to improve water quality in the Imbakucha watershed of highland Ecuador

Poor water quality is a leading cause of environmental and health problems in the “developing” world. The Imbakucha (Lago San Pablo) watershed in highland Ecuador is no exception. Absence of adequate wastewater treatment and contamination of surface waters threaten the health of local residents and the health of a valued aquatic ecosystem. Water treatment systems using aquatic plants and/or wetlands have been widely applied in North America and Europe, but have only recently been implemented in developing countries where it would seem they should be well suited. This study tested the feasibility and efficiency of surface flow wetlands, planted with Scirpus californicus , to treat domestic wastewater and contaminated surface water. S. californicus was selected for its potential economic benefits as it is a valued primary resource used in a traditional local craft trade. Though small in size and with short retention times, the experimental wetlands were found to significantly reduce concentrations of E. coli and phosphorus. Nitrogen was reduced significantly only when inflow concentrations were above background concentrations. The concentration of Total Coliforms was not significantly reduced in the wetlands. It is concluded that with adequate training to local community members S. californicus wetlands could play an important role in improving water quality within the watershed.