DETECTION OF SUBSURFACE CONTAMINATION
RESIDUAL PHASE

     COLLECTION

- continuous vertical sampling of soils with geoprobe
lithologic description of soils
sampling and preservation of soils for analyses

  ANALYSES


SCREENING ANALYSES
- BTEX, TPH
- C5+
- Synchronous Fluorescence

EPA ANALYSES
- BTEX, TPH
- High Resolution GC
- PAH
- RCRA Metals


INTERPRETATION

  KEY CONCEPTS

- in a typical petroleum fuel hydrocarbon spill, approximately 95% of the mass is contained in the subsurface as residual phase contamination (and free phase)
- the residual phase contamination in soils will act as a continuous source of dissolved phase contamination regardless of natural attenuation in the aquifer
- the most critical and damaging phase of petroleum fuel contamination
- determines the vertical distribution of contamination
- locations of direct-push ground water samples, monitor wells and product recovery wells should be selected from areas of maximum residual phase contamination in soils