Summary

Brasília is one of the few large cities in the developing world that provides full coverage of sanitation services for its population, including the collection of wastewater and adequate wastewater treatment. Caesb, the local water and sanitation utility, has developed a lot of experience in the planning, design, construction, and operation of sanitation systems, with a special emphasis on the need to use appropriate treatment technologies. Today, serving a population of more than three million people, Caesb runs 16 wastewater treatment plants, using technologies from very simple natural treatment processes, such as stabilization ponds and overland flow processes, to very sophisticated units, including tertiary activated sludge plants, with flotation as an effluent-polishing treatment step. During the development of the several different sanitation solutions, Caesb has found that it has been best to use simple, natural, low-cost treatment processes to achieve feasible and sustainable solutions even when, in specific circumstances, more sophisticated processes are required. The desire to increase the sustainability of the treatment plants has also stimulated Caesb to improve the performance of the applied treatment processes, which was achieved by the implementation of several modifications aimed at reducing costs and improving the efficiency of the plants. Today, the treatment of all wastewater produced in the city guarantees the quality of the discharge to the point that water bodies located downstream of wastewater treatment plants are used as resources for water supply for the city.