Superfund Innovative Technology Evaluation (SITE)
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
Characterization Analysis Penetrometer System (SCAPS)
The SCAPS program is developing a variety of downhole sensors. This demonstration examined the ability of the LIF (laser induced fluorescence) sensor to detect petroleum hydrocarbons. The U.S. Army holds a patent for the use of a sapphire window to transmit and return incident light and contaminant induced fluorescence. The core of the LIF system is the nitrogen laser used to induce a fluorescence response in soils. The cone penetrometer system consists of a 20-ton truck, hydraulic rams and associated controllers, and the cone penetrometer itself. The hydraulic ram advances segments of threaded push rod 1 meter long. The cone penetrometer, which is mounted on the end of the series of push rods, contains sensors that continuously log tip stress and sleeve friction used to map subsurface stratigraphy. Conductivity and pore pressure sensors can be driven into the ground simultaneously. The LIF sensor, mounted slightly above the cone penetrometer sensor, accumulates fluorescence emission responses which are displayed with soil classification data. The field demonstration was held during September 1994.