Management of Urban Wastewater on One of the Galapagos Islands

Since 1984, the Galapagos Islands have been included in the program UNESCO-MAB (Man and Biosphere Programme) due to the increasing need to safeguard their outstanding natural ecosystems and promote economic progress based on principles of sustainable development and environmentally friendly technologies. The Ecuadorian government, also by special laws, has legislated in favor of the environmental protection of the archipelago, with the intention to control the flow of migrants from the continent to the islands. Today, with the further problems created by the massive influx of tourists, is it necessary to establish planned areas of urban expansion that are already equipped with a suitable system of collection and treatment of wastewater. This paper focuses on the city of Puerto Ayora, the main town of the island of Santa Cruz, where increasing human pressure has led to, among various other consequences, an increase in water demand, which has highlighted the inadequacy of the current wastewater treatment system, based primarily on single-family septic tanks without additional depuration. Among the various actions proposed to solve the increasing health and environmental hazards, caused by the partially treated wastewater, a centralized sewer system for the drainage and the depuration of the wastewater produced by the users connected to the network has been proposed in order to serve the community of Puerto Ayora. This project is currently experiencing a slow implementation process due to technical difficulties. Our intention is to propose a different wastewater management system, which is modular, easily replicable and which requires low maintenance. A flexible and easily manageable system, such as that proposed, could be implemented in other contexts such as, for example, in developing countries. In this specific case, the main purpose of this study is to investigate how to ensure a healthy environment for tourists and residents, without neglecting our duty to respect the ecosystems of this extraordinary island, by defining a model of wastewater management which should be economically and technologically sustainable in this particular context. In fact, the soil, formed by lava rock does not allow for very deep excavations and being so far away from the mainland means that technologies that are easily maintainable on site must be deployed. The study was carried out according to the Millennium Development Goals, Ecuadorian legislation, the suggestions of the Pan American Health Organization, relevant scientific literature and some data collected from site surveys.