Abstract: A sensing device to detect contaminants of known dielectric value such as hydrocarbons when present in a medium with a different dielectric value such as water comprising a plurality of capacitive members electrically connected to a sensor signal generator including a plurality of sensor channels corresponding to the plurality of capacitive members to generate a sensor signal corresponding to the dielectric value of the medium surrounding each of the plurality of capacitive members and a detect signal generator including a plurality of detect channels corresponding to the plurality of sensor channels to receive the sensor signal of the corresponding sensor channel and to generate a contaminant detection signal when each sensor signal from each sensor channel is within a predetermined range of the dielectric value of the contaminant to be monitored.