Common guidelines on water reuse in all Mediterranean countries have been proposed by Bahri and Brissaud (2002). These guidelines have been developed under a project funded by UNEP/WHO and have been presented in various meetings. These are based on the consideration that: (a) an agricultural Mediterranean market is developing with large amounts of agricultural products (vegetables, fruits, etc) imported and exported among Europe and other Mediterranean countries; (b) tourism is an essential part of the economic activity of the region; its development might be jeopardized in the long term by disease outbreaks linked to wastewater mismanagement; (c) there is a growing concern of consumers about the food quality and health hazards; (d) unfair competition among farmers should be avoided. These guidelines have been prepared making a large use of the results of the recent assessment of the WHO guidelines by Blumenthal et al., (2000).
However, contemplating to set up Mediterranean guidelines raises three questions: (a)how to derive health guidelines for water reuse, which would be applicable in many different settings of the Mediterranean Region, in economically less developed countries as well as in industrialized ones? (b)can uniform water reuse guidelines be realistically enforced in every country of the region ? (c)does the actual knowledge allow a definitive position regarding the limits to be set up? In addition, it should be noticed that: (a)populations of the North and South banks are both exposed to contamination of food and the Environment, (b)guidelines provide a reasonable health protection defined through either the concept of "no measurable excess risk of infection attributable to wastewater reuse" or an acceptable maximum annual risk, and (c)guidelines are not unnecessarily too stringent, i.e. too costly with regard to the risk reduction.
As non potable reuse will long remain the goal of the large majority of the reuse projects, these draft guidelines for domestic water reuse for the Mediterranean Region are focused on the microbiological hazards. Four categories of recycled water uses are considered (see table 13): Category I: urban and residential reuses, landscape and recreational impoundments.Category II: unrestricted irrigation, landscape impoundments (contact with water not allowed), and industrial reuses.Category III: restricted agricultural irrigation.Category IV: irrigation with recycled water application systems or methods (drip, subsurface, etc) providing a high degree of protection against contamination and using water more efficiently.
Table 13: Proposed Mediterranean guidelines
The proposed Mediterranean guidelines are minimum requirements which should constitute the basis of water reuse regulations in every country of the region. Wealthy countries might wish higher protection. Due to late development of wastewater treatment in several countries, all of them cannot be expected to comply with the guidelines within the same delay. However, every country could commit itself to reach the guidelines within a delay depending on its current equipment and financial capacities.