The sensitivity of gravitational waves interferometers is limited by numerous sources of noise. One such source arises from the charge deposition on the test mass, which interacts with the surrounding electrical field, introducing an undesired non-gravitational force on the test mass. Unfortunately, very little is known about the charge deposition and its dynamics, so that this noise is among the least modeled in the detector. In this chapter, we illustrate a procedure for implementing an effective and non-invasive charge monitoring system capable of extracting the maximum amount of information with minimal disturbance. Specifically, we explain the proposed methodology and compare different possible criteria in the choice of the monitoring system.