Bidding of the ‘Agua Prieta’ Wastewater Treatment Plant for the city of Guadalajara, México

During 2008 and 2009 a bidding process was undertaken for the Agua Prieta Wastewater Treatment Plant. The awarded contract included partial financing, design, build, equipment supply, start up and 20 years operation and maintenance. Plant capacity is 8,500 L/s as mean flow and population equivalent of 4.9 millions. The treatment process is composed of pretreatment, primary treatment, activated sludge reactor and secondary clarification. Sludge is anaerobically digested, using the produced biogas for electricity cogeneration. The site in which the plant is located has significant restrictions in relation to size and other features. These had a relevant impact in the offered treatment processes. The purpose of this paper is to share the experiences gained in this complex bidding process, including the guidelines and design criteria incorporated in the bidding documents, as well as the main technical features of the selected proposal. The plant is presently under construction.