Evaluation of the Three Decades of Treated Wastewater Reuse in Tunisia

Abstract

Tunisia is one of the developing countries that have developed the use of treated wastewater in irrigated agriculture for more than 30 years. Increase in water demand, as a result of population growth and development plans, is posing serious threats on the existing conventional water resources, including drought impact and stressed water supply with deterioration of water quality. The agricultural sector remains the highest conventional water user with more than 83% consumption. Practically, treated wastewater provides an alternative source of water that can fill an important gap in water deficit for agricultural production and other uses. It represents a strategic option to achieve a higher level of water supply for agriculture and food production and will alleviate the pressure on conventional water resources (Agodzo et al., Use of treated wastewater for irrigation in agriculture: Proposal for a comparative study of Bolivia, Ghana and Tunisia. Wageningen, The Netherlands, 2001).

In 2007, this study was done in the Cap Bon region in the north of Tunisia where most of the TWW reuse was in the irrigated agriculture. There is a high competition between water users’ sectors: agriculture, industry, and tourism. This chapter focuses mainly on the evaluation of the regional experience by highlighting the farmers’ acceptance and perception of treated wastewater for irrigated agriculture.

In this irrigated area, 100 farmers were interviewed and their farms were visited for observation during the irrigation period. All the farmers were using traditional irrigation method; surface irrigation that leads to considerable loss of water.

This study aims to understand and find out the barriers of the use of treated wastewater in this region considering the high volume of treated wastewater discharged to the sea.

In this region, farmers still confronted more water-scarcity problem. Treated wastewater reuse is common since 1979 because of the increasing water demand, the succession of dry season (more than 5 years of drought), and the increasing aquifer salinity.

In spite of this situation, farmers’ reluctance to treated wastewater reuse is still presenting a very serious problem. The interesting observation made in this study is that, farmers lack information and knowledge about the need for safe and optimal reuse of this water resource.

During the study of the farming practices, 80% of the farmers said that they are not informed about water quality and 42% said that they are not informed about how to use treated wastewater. Most of them mentioned that they are only informed about the prevention methods such as wearing special shoes and vaccination, about which they were not much interested. Hence, farmers’ practices are mainly based on their own experiences, personal perceptions, and points of view.

The key issue here is the emphasis on information and education programs with demonstration areas for any TWW reuse to preserve practitioners’ health and environment contamination.