The present work is based on a real project developed by Cetaqua in collaboration with Avecom, a company devoted to steering and optimizing microbial processes. This work aims to study the feasibility of an innovative layout for a wastewater treatment plant (WWTP). This new point of view pretends to enable the plant to be self-sustainable, by increasing the sludge produced in a Pre-concentration step at the inlet of the WWTP, and therefore increasing the biogas produced in the anaerobic digester. In order to reach this goal, a revision of the state of art is carried out; furthermore there is a detailed description of methodology, which comprehends the definition, design and start-up of the pilot plant; the new WWTP is under demonstration due to the pilots already are in start-up phase. Economic feasibility is evaluated taking as a starting point the expected results of the project. Finally the most significant conclusions and lessons learned are summarized.