- 4.4 Pollution by wastewater disposals and nutrient loss in the Sebou basin, Morocco

The Sebou basin is the most polluted basin of Morocco. The sources of pollution are multiple: (1) pollution by households: 82 cities and urban centres in the basin dispose an annual volume of wastewater of approximately 80 million m3. These disposal generate a total organic pollution of about 76.000 tons of DBO5; (2) pollution by industry: The industrial activity is concentrated in the large cities such as Fès and Kénitra. The industrial activity generates nearly 3,5 million equivalent-inhabitants of organic pollution, of which nearly 70% come from the sugar refineries, paper and oil mills; (3) pollution by the agricultural sector: the basin of Sebou is among the agricultural areas most important of the country. The sector knows an intensification by the irrigation and the use of manures and pesticides. These agrochemical products infiltrate to the groundwater; (4) uncontrolled public disposal: The uncontrolled public diposal constitutes a considerable source of pollution. The total production is estimated at 750.000 tons/year, causing a pollution of approximately 6 900 tons of DBO5; (5) Accidental pollution also constitutes a considerable source of pollution. (4-5-a Les sources de pollution - p. 17; 4-6 Problématique du littoral et des zones humides - p. 22)