Abstract
This contribution proposes a theoretical model to support the environmental assessment for the organizations aiming at implementing an EMAS-ISO auditing process in the ground of the water services industry. The model tries to combine a new theory of value – based on natural, bio-genealogical and semantic surplus – with the cycle input - output - re-input characterizing namely the most critical area of the integrated waters service, the waste water treatment plants. A multidimensional pattern based on the Multi-Attribute Value Theory has been assumed as an effective operational framework connecting the contents of the treatment process, as defined by the scientific and technological tools supporting the judges of fact, and the issues of sustainability, supporting the value judgements.