Environmental Risk Assessment of the Reuse of Treated Wastewaters in the Souss-Massa River Basin

Abstract

Souss-Massa watershed is suffering more and more from hydraulic deficit and the use of treated wastewater represents an alternative for water conservation, and sustainable economic growth of the region. The Agadir region is known for its agriculture and its tourist attraction, which puts a lot of pressure on water resources, and at the same time the potential of treated wastewater is around 50 million m³/year. The use of municipal wastewater (treated and untreated) in agriculture is becoming a routine practice in many (semi-) arid countries of the world. Wastewater and its nutrient content can be used extensively for irrigation and other ecosystem services, cutting on groundwater and freshwater consumption. Wastewater also offers environmental and socioeconomic benefits such as reduction in effluent disposal problems, supply of nutrients as fertilizer, and improvement in crop production during the dry season. Its reuse can deliver positive benefits (save freshwater, save fertilizer, and prevent pollution) to the farming community, society, and municipalities. Despite these advantages, wastewater applicability for irrigation depends on its physical, chemical, and microbiological quality. In fact, a continuous use of wastewater may cause serious health problems for humans and animals because of the possible heavy metal content. Therefore, it is of paramount importance to continue thorough investigations to evaluate the effects of wastewater irrigation on crops, grasses, soil, and environment before recommending it for long-term use.

This chapter provides insights on wastewater use practices in Souss Massa, where water scarcity is always the major consideration. It also provides an understanding of the constraints and limitations of such an assessment, and the importance of developing a clear strategy for future assessments. It also highlights the potential of wastewater reuse in the Souss-Massa region. The analysis shows that a variety of constraints inhibit formal reuse of wastewater in the region, including the cost of reuse, low demand for reclaimed wastewater, the widespread lack of effective price signals and cost recovery in the water sector, and challenges in structuring the financing of reuse.