an optical sensor capable of detecting the presence of liquid at a first predetermined level in the confined area, wherein the optical sensor is mounted in the confined area such that the optical sensor terminates at the first predetermined level and an electrical circuit of the optical sensor triggers a first alarm when the optical sensor is in contact with liquid; and

a capacitance based dielectric sensor capable of differentiating between conductive and non-conductive liquid, wherein the capacitance based dielectric sensor is mounted in the confined area such that the capacitance based dielectric sensor terminates at a second predetermined level that is at least 1/16″ above the first predetermined level, the capacitance based dielectric sensor is operatively coupled to the optical sensor such that the electrical circuit of the optical sensor activates an electrical circuit of the capacitance based dielectric sensor only when the optical sensor detects the presence of liquid at the first predetermined level in the confined area, and the electrical circuit of the capacitance based dielectric sensor triggers a second alarm when the capacitance based dielectric sensor is in contact with a non-conductive liquid.