en This project will have a significant environmental impact is an important vehicle for the urban development, city tourism and economic of the ochre. In the absence of a process to purify the sewage from the city, the wastewater, the average production of 90,000 m³ / day, are collected and deposited mainly in the rugged terrain of three points in the streets of Casablanca and Safi and the north of the oued tensift.