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EGG Laser Induced Fluorescence (UVOST) Gregg Drilling conducts Laser Induced Fluorescence (LIF) Cone Penetration Tests using a UVOST module UV Induced that is located behind the standard piezocone, Figure Fluorescence Fibre Optic Cable UVOST. The laser induced fluorescence cone works —Ultra Violet on the principle that polycyclic aromatic hydrocarbons Source (PAH's), mixed with soil and/or groundwater, Sapphire fluoresce when irradiated by ultra violet light. window Therefore, by measuring the intensity of fluorescence, the lateral and vertical extent of hydrocarbon contamination in the ground can be determined. Triaxial ceophones or Accelerometer The UVOST module uses principles of fluorescence spectrometry by irradiating the soil with ultra violet light produced by a laser and transmitted to the cone Inclinometer through fiber optic cables. The light is then passes through a small window in the side of the cone into Thermistor the soil. Any hydrocarbon molecules present in the - Friction soil absorb the light energy during radiation and Load Cells Sleeve(FS) immediately re-emit the light at a longer wavelength. This re-emission is termed fluorescence. The UVOST Pore Pressure system also measures the emission decay with time Porous Filter Transducerju,) Element at four different wavelengths (350nm, 400nm, 450nm, Cone Tip(y,.) and 500nm). This allows the software to determine a product "signature" at each data point. This process Figure UVOST' UVOSTsystem allows determination of the type of contaminant as deployed with the CPT shown in Figure Concept. In general, the typical detection limit for the UVOST system is <100 ppm and it will operate effectively above and below the saturated zone. With the capability to push up to 600 feet per day, laser induced fluorescence offers a fast and efficient means for delineating PAH contaminant plumes. Color coded logs offer qualitative information in a quick glance and can be produced in the field for real-time decision making. Coupled with the data provided by the CPT, a complete site assessment can be completed with no samples or cuttings, saving laboratory costs as well as site and environmental impact.