Objectives of the Demonstration

Site characterization currently represents at least one-third of the cost of remediation efforts by the Department of Defense (DoD). Problems associated with the traditional trial-and-error site characterization methods such as cost, sample transport, timeliness, and uncertainty have frequently hampered DoD's remediation efforts. This ESTCP project demonstrated the field application of a laser-induced fluorescence (LIF) petroleum sensor mounted in a penetrometer.

The LIF petroleum sensor uses an instrumented probe that can be pushed into the ground with a truck-mounted hydraulic system called a cone penetrometer. The cone penetrometer makes real-time chemical measurements of petroleum hydrocarbons in subsurface soil up to a potential maximum depth of 50 meters. The chemical sensor uses a laser to generate a characteristic "glow" from the petroleum contaminants. The "glow" can then be measured to determine the level of these contaminants. The optical screening method provides a nearly continuous profile of the petroleum contaminant distribution as the probe is pushed into the ground. This unique ability is a marked improvement over traditional core sampling procedures that may be compromised by core sample contamination or loss of well integrity. Real-time analysis of site contamination also eliminates complicated drilling procedures and the long process of packing and shipping samples to a laboratory.