Zootechnical Farm Wastewaters in Ecuador: A Treatment Proposal and Cost-benefit Analysis

This paper presents and discusses the results of a study carried out in Ecuador, where the zootechnical sector represents one of the country's most important economic activities. It is, however, the source of many environmental problems, including the release of untreated liquid effluents and odorous emissions, and the production and disposal of solid wastes. The main aim of this study was to propose a treatment train for the zootechnical farm wastewater, combining natural systems (i.e., lagoons and subsurface flow beds) with conventional technologies and a cost-benefit analysis. With reference to a specific case study, the different steps of the treatment train were designed and the corresponding construction, operational and maintenance costs evaluated. To better assess the technical and economic feasibility of such a proposal, a cost-benefit analysis was carried out. The social benefit was evaluated by means of the contingent valuation method and a focus on the methodology and collected results was reported. The main findings discussed, in terms of selected treatments, their costs, and the financial and economic analysis of the project, could be useful for administrators, decision-makers and all technicians involved in planning and management of zootechnical farm wastewaters in developing countries, in particular in Latin America.