This technical report deals with two of the main tasks of Fault Monitoring Systems (FMS): fault detection and fault identification. During fault detection, the FMS should recognize that the plant behavior is abnormal, and therefore, that the plant is not working properly. During fault identification, the FMS should conclude which type of failure has occurred. The main goal of this work is to consolidate a new fault detection technique, called enveloping, and to study the performance of the model acceptability measure as a tool to enhance and make more robust the fault identification process in the context of Fuzzy Inductive Reasoning Fault Monitoring System (FIRFMS). The enveloping technique and the model acceptability measure are applied to a water distribution network in order to detect specific faults and to identify them. This report is focused as a detailed description of the full work developed in the context of the water demand application. It does not pretend only to show the results obtained by FIRFMS to the application at hand but to present in detail all the steps done to reach these results.