THE PASCO REGION IN PERU IS AN AREA THAT HAS HISTORICALLY BEEN POLLUTED BY MINING ACTIVITY AND POPULATION GROWTH. AS A RESULT, THERE IS AN INCREASED PRODUCTION OF URBAN WASTEWATER AND ACIDIC WATER THAT CONTAMINATE LOCAL LAKES SUCH AS QUIULACOCHA AND PATARCOCHA. THE CONSTRUCTION OF A TREATMENT PLANT THAT CAN TREAT THE DIFFERENT TYPES OF WASTEWATERS HAS NOT YET BEEN STUDIED, AND ITS SUSTAINABILITY HAS NOT YET BEEN EVALUATED. THE OBJECTIVE OF THIS RESEARCH WAS TO PREDICT THE SUSTAINABILITY OF CO-TREATMENT SYSTEMS IN DIFFERENT SCENARIOS BETWEEN URBAN WASTEWATER AND ACIDIC WATER, EXPRESSED IN TERMS OF A TERNARY EMERGY DIAGRAM. THE DESIGN OF THE CO-TREATMENT PLANT WAS CARRIED OUT AT AN INFLOW OF 10 L/S. THE FIRST SCENARIO (TREATMENT I) HAS A PRIMARY SETTLER FOR THE MIXTURE OF URBAN WASTEWATER AND ACIDIC WATER, WHILE THE SECOND SCENARIO (TREATMENT II) INVOLVES A SETTLER AND A SUBSURFACE ARTIFIC...