Seia’s WWTP was designed to supply the needs of Seia and Gouveia municipalities, thereby, it has been built with a nominal capacity of 3.022m3 /d, serving a population of 21,156 people. This Construction passed through a preliminary treatment (wet sieving, desanding and degreasing), a secondary treatment (biological treatment by activated sludge by extended aeration regime in oxidation and secondary sedimentation tank ditch), tertiary treatment (removal nutrients, microtamização and UV disinfection) sludge treatment (thickening and mechanical dewatering) and deodorization by activated carbon filter.