Renewal, expansion of the sewage network and construction of a waste water treatment plant in Bahía de Asunción for 480,000 inhabitants. Noteworthy are 14km of main collectors, 35 km of secondary collectors, 3 pumping stations, 1.4km of pumping lines, water treatment at 760l/s with underwater outfall (1,300 mm in diameter). We carried out operation and maintenance for 1 year.