Abstract: A system and method for direct and/or active detection and monitoring of civil engineering or other infrastructural structures, and in a preferred embodiment, for hydrocarbon leakage in oil and gas pipelines, storage structures, and/or transportation structures. Particularly, the system and method relate to various nanocomposite sensor coating and data gathering systems. In one embodiment, the apparatus includes a single measurement sensor coating (thin film) sensor. Other embodiments relate to multiple measurement sensor coating systems. The sensor is comprised of either a discrete conductive filament layer, or a single or multiple mesh of interwoven filaments of conductive material in one direction and nonconductive material in a perpendicular direction, as a substrate coated with sensitive coating materials to form a sensor grid. Various embodiments of the sensor coating and their applications are also disclosed.