Isla Mayor is a municipality in the province of Seville in the Vega del Guadalquivir region. It is located in the middle of the marsh, very close to the Guadalquivir and the Doñana National Park._x000D_ The area of the municipality is 9.825 ha, of which 9,711 are dedicated to irrigated crops and 114 are occupied by the population. The population registered in 2015 is 5,938 inhabitants, which are distributed as follows: Isla Mayor 5,457 inhabitants, Poblado Alfonso XIII 430 inhabitants and disseminated population 51 inhabitants._x000D_ The village of Alfonso XIII is located 3.4 km north of Isla Mayor and occupies an area of 8.5 ha._x000D_ Its wastewater lacks treatment and is discharged to a ditch. The core of Isla Mayor belongs to the environment of Doñana and despite having a WWTP, its urban discharges are not yet subject to an adequate purification system, having also discharge points whose waters are not carried to said WWTP._x000D_ _x000D_ This project is the object of this project the design, definition, measurement and valuation of the works corresponding to the NEW EDAR OF ISLA MAYOR (SEVILLA), which includes the adequacy of the existing WWTP in the municipality of Isla Mayor for the treatment of the aforementioned discharges._x000D___