The present research work entitled "Design a wastewater treatment system to mitigate the pollution of the river May, Juan Antonio Sector - Moyobamba, 2014" was developed in the Juan Antonio sector, area where is poured domestic wastewater produced in the Moyobamba city. It 's main object study to design a system for treating wastewater discharges into the river Mayo, Juan Antonio sector ; which it was conducted through the characterization of wastewater discharged to the Mayo River in order to propose a treatment system quantitatively evaluating the efficiency treatment levels. For such action was necessary to take samples, for then to be analyzed and to know the values of the parameters to treat. The same that allowed us to contrasting with the maximum permissible limits laid down in the national standard in force. The current state of the discharge of wastewater discharged into the riv...