Water reuse was officially legitimized in 1991 through the regulation for irrigational wastewater reuse issued in by the Ministry of Environment. According to the "Water Pollution Control Regulations", in order to use treated wastewater in irrigation, a written permission from concerned government organisations must be obtained. A commission organized by the State Water Organisation, İller Bank and Agriculture Ministry and Environmental and Forest Ministry will decide whether the effluent can be used in irrigation or not.

The effluent quality criteria for irrigation according to the Turkish Water Pollution Control Regulations are given in the following tables. In general, the WHO standards have been adopted except the limits for the intestinal nematodes and the residual chlorine. Concerning the microbiological standards, the Turkish regulation seems unsufficient and needs to be revised according to the actual discussions (as mentioned before).

Boron concentrations are particularly important for Turkish conditions because Turkey is rich in terms of boron sources. Therefore water for irrigation is separately classified with respect to their boron concentrations which is not named expressively here.

Table 8: Maximum Concentrations of Toxic Elements in Effluents for Irrigation

¹ With respect to Boron concentration there is even a more detailed classification of irrigation waters

Table 9: Effluent Quality Criteria for Irrigation