The production process of olive oil in Morocco is dominated by systems that generate a by-product, olive mill wastewater, harmful to the environment. In this article, specific approaches are proposed to bring millers for adhering to the greening of this agribusiness. The results reveal that it would be interesting to direct some olive oil producers to preventive techniques, although expensive for the majority of these operators, but do not produce olive mill wastewater. Millers concerned are those with very high incomes, or those predisposed to organize themselves within the framework of producer groups, or those with adaptable equipment. The technique of control, represented by the exposure of olive mill wastewater to natural evaporation in basins, should primarily target the old oil mills established before the promulgation of regulations on Environmental Impact Assessment. Also, olive mill wastewater collection actions should be directed to oil mills which do not have space for basins. Finally, aid should be made to poorest millers for building evaporation basins.