The processing of sugar cane in Morocco is by specific industrial units. The SURAC Company (Dar Gueddari) produces significant quantities of sugar and molasses in a period of production that extends the month from January to June Wastewater produced by this activity is characterized by very high loads of organic matter whose flow is 1200 m3 / d. The stock SURAC its wastewater Lagoons with limited capacity for pretreatment in wastewater. The aim of our study was to assess the pollution of waste water from the SURAC at the lagoon which is adopted by the SURAC as a means of treating these liquid discharges. The physicochemical analysis of effluent from the SURAC gave the following average values: PH (Moy=4,15), Temperature (Moy= 25