Amid the Brazilian midwestern plains, is “Primavera do Leste”, a city located 237 km from Cuiaba, capital of Mato Grosso province. This is a city developed mainly in agriculture and commerce fields and is one of the cities that stand out in the growth of population (approximately 60,000 in just over 22 years after established as a city). Privileged by its location, as well as strength in commercial and business field have been contibutated to progress of the city.
Due to the fast growing of the city, the company Ãguas de Primavera began operating a sewage system. At the begining, the effluent treatment system was inefficient because it had a low rate of households coverage; only 1280 households had access to the sewage network. Today, the system has 63,059 meters of collector network and improved the operation system with the construction of new inlet and oulet for the effluent from the anaerobic pond. Finally, the collection network increased to more than 2845 homes.
The effluent treatment plant uses stabilization ponds, which are one of the most efficient when there are space and time available. Further, no skilled labor is needed to operate this system.
The system consists of:
– One separation unit waste and effluent;
– One sand decantation unit;
– One measurement unit;
– One anaerobic pond;
– One facultative pond;
– Three maturation ponds;
As the population increased and the city expanded, upper class residents who moved nearby the treatment plant, started complaining regarding bad odors generated by the plant.