Abstract: The present invention describes a subsurface soil contaminant identificat system method using a cone penetrometer unit for in-situ elemental composition identification in the form of solids, liquids or gasses. Elemental identification is achieved by using atomic spectral analysis of the contaminants that are stimulated by a laser induced breakdown of the soil contaminants to be determined. The system includes a high resolution spectrometer with array detector, a controller for control/data acquisition, a penetrometer push operation controller and data gathering equipment, an optical fiber link to a cone penetrometer with improved optical focusing components. The improved method of using the system entails: i) soil characterization during an initial penetrometer push, then ii) contaminant identification during the penetrometer retrieval phase from a soil bore hole formed during the initial push.