Evaluación y propuesta de rediseño de la planta de tratamiento de aguas residuales de Santa Ana, parroquia Santa Ana, Cuenca, Ecuador

Abstract

The Municipal Public Institution in charge of the telecommunications, drinking water, sewerage and sanitation in Cuenca (ETAPA EP) has identified a decrease in the efficiency of the wastewater treatment facilities located in rural areas. To return operability and efficiency to these wastewater treatment plants (WWTP), this project focuses in the evaluation and a redesign proposal of the decentralized system located in the community of "Santa Ana", in Cuenca canton. The state of the WWTP was established through field inspections, affluent flow measurements, and wastewater characterizations, and it is currently conformed of an arrival structure, a septic tank, an anaerobic filter and three wetlands. The redesign proposal includes a preliminary treatment composed of a bar screen, a grit chamber and a triangular weir. Interventions to the existing septic tank and the anaerobic filter are proposed to ensure the treatment efficiency, and the wetlands elimination is proposed for the implementation of a second septic tank and chlorination disinfection. The small space available for the units placement difficult the implementation of another disinfection process for the removal of high values of pathogens present in the wastewater, but due to the high risk in the formation of toxic compounds, the implementation should be analyzed deeply. The operation and maintenance manual, and the budget are included in the redesign proposal.