Regional factors governing performance and sustainability of wastewater treatment plants in Honduras : Lake Yojoa Subwatershed

Abstract

Lake Yojoa, the largest natural lake in Honduras, is currently experiencing eutrophication from overloading of nutrients, in part due to inadequate wastewater treatment throughout the Lake Yojoa Subwatershed. Some efforts are being made to address the issue of wastewater treatment, but they frequently suffer from lack of oversight and follow-through. As a case study, in 2008, a wastewater treatment plant was built to treat sewage from Las Casetas, a group of restaurants and small homes on the southeastern shore of the lake. However, the piping used to connect the casetas to the treatment plant was not built to specification and subsequently failed, and the project was essentially abandoned. The aim of this study was to determine whether the treatment plant and piping system at Las Casetas were adequately designed in order to provide recommendations for rehabilitating the system. A full analysis of the system suggests that, with the exception of a few minor changes, both the treatment plant and piping system were well-designed and, in the case of the treatment plant, well-constructed. With funding from PRONADERS (the Program for National Sustainable Rural Development) and involvement from the association of fish restaurant owners at Las Casetas, we propose that rehabilitation of the system move forward. Rehabilitation of the Las Casetas treatment plant will provide two major benefits to the community. First, it will decrease the nutrient loading to Lake Yojoa, which will be an important first step in solving the eutrophication problem. Residents of the region are well aware of this ecological issue, as local fish farmers are currently being employed to remove water lilies from the lake. These aquatic plants have grown in excess in recent years due to eutrophication. Secondly, use of a wastewater treatment system will improve public perceptions of the cleanliness of the fish restaurants, whose business has suffered due to negative perceptions of the quality of the lake. These perceptions are also due, in part, to pollution from other sources, including Aquafinca, a tilapia farming cooperation, and agricultural practices in the region. We therefore also propose that a full nutrient budget of the lake be carried out, with input from all sources of pollution, in order to determine where the main causes of the problem lie and how best to proceed to reduce ecological damage.