Starting from the data measured through laboratory tests during 2020 and 2021, a set of parameters have been evaluated. Each day of analysis has been associated to a class, basing on thementioned values. In such a way it was possible to compute the percentage of times in which the water from a specific plant has been in the different classes . Collecting the data measured in each plant, the four classes have been defined setting limit values of these parameters. a set of rules was defined in order to identify the dominant water quality class for each WWT plant, based on the previously obtained percentages. :•If the effluent falls in water quality class A at least 90% of the time →the dominant class for that plant is A. •If the effluent falls in water quality class A less than 90% of the time AND 0% of the time in class D →the dominant class for that plant is B. •If the effluent falls in water quality class A less than 90% of the time AND below 10% in class D →the dominant class for that plant is C. •If the effluent fallsin water quality class D more than 10% of the time →the dominant class for that plant is D. This allowed a classification of the available WWTPs according to their dominant class and, thus, application of the EU regulation 2020/741. Therefore, for each WWTP, the WebGIS can show what crop types can be irrigated with their effluent, as well as the allowed irrigation method/s