A GIS APPROACH FOR EVALUATING WASTEWATER REUSE FOR IRRIGATION IN SICILY

In Italy, water reclamation for agricultural irrigation reuse still faces with restricted law standards and is conditioned by poor local endorsement. However, this practice is widely applied, sometimes without control. In fact, Italian regulation on wastewater (WW) reuse (Ministry Decree, M.D. n. 185/03) is quite limitative when considering some specific chemical and microbiological parameter, leading to standing–off scenery in WW reuse. It should be underlined that the reuse of treated wastewater in agriculture could represent a valid alternative to the use of conventional resources at large-scale, for example at the irrigation district level. Sicily is affected by more than 30% gap between water availability by conventional sources and water demand. The present work mainly focuses at the evaluation of the potential of the wastewater reuse in Sicily, where there is a consistent water resources shortage for agriculture sector due to climate changes. A Geographical Information System (GIS) at regional level was realized to quantify and locate the available WW volumes. In particular, the characteristics of the wastewater treatment plants (WWTPs) (location, altitude, person equivalent, treatment level, working state, treated volume…) were integrated, through the GIS, with data on irrigation district areas (surface, location, altimetry, potential evapotranspiration, water needs, available water resources, distance to the nearest WWTP,…). Furthermore, the Italian legislation for wastewater reuse for agricultural irrigation was compared to the WHO guidelines when analysing the water quality of different treatment effluents. The microbiological quality standards of Italian law were effectively too restricted. Finally, the Italian legislation needs to be considerably revised to allow sustainable wastewater reuse plans for irrigation, particularly in the case of small and medium communities.