ETE Floriano Wastewater Treatment Plant - Barão de Grajaú, Maranhão, Brazil

ETE Floriano is a municipal wastewater treatment plant located in Barão de Grajaú, in the state of Maranhão, Brazil. The facility serves a population of approximately 5,425 people, placing it in the small-agglomeration category typical of inland towns in the Northeast Region. The plant provides secondary treatment, which is the standard biological process required under Brazilian regulations (CONAMA resolutions) for communities of this size. Secondary treatment removes organic matter and suspended solids, ensuring that the effluent meets basic quality standards before discharge. The plant processes an average daily flow of 527.04 cubic meters. Treated effluent from ETE Floriano is discharged into local watercourses that drain into the Parnaíba River basin, one of the major river systems in northeastern Brazil. The Parnaíba River flows northward to the Atlantic Ocean, supporting diverse aquatic life and providing water for agriculture and communities along its course. The plant's operation helps protect downstream water quality in this ecologically important basin.

The plant discharges into local streams that are part of the Parnaíba River basin, which drains into the Atlantic Ocean via the Parnaíba Delta. This basin supports a variety of freshwater species and is an important resource for local communities. The region's semi-arid climate makes water quality management critical for maintaining ecosystem health and human use.