|
|
|
| Soil
Sampling |
INTRODUCTION
This information is a guide for assisting Remedial Project Managers (RPM’s) and others
involved with site assessments and remediation in the development of soil sampling
protocols. The document updates a guide published in 1983 (Mason, 1983). Since that time
considerable work has been done in the areas of geostatistics, quality assurance,
particulate sampling theory, field analysis, and sample handling.
Kriging, one of the geostatistical tools mentioned in the 1983 report has now become an
accepted tool for use in soil (and soil-borne waste) sampling. The purpose of this tool is
to provide an estimate of the concentration in a sampling unit or a specific volume of
soil and to estimate the variance associated with the concentration estimate. Kriging,
combined with the semi-variogram, is very useful in designing and conducting soil and
waste sampling efforts.
At the time of the earlier report kriging could only be done on a mainframe computer.
Today
there are a number of PC-based programs that assist the user in evaluating soil sampling
data
(Englund and Sparks, 1988; Grundy and Miesch, 1987). The U.S. EPA Environmental
Monitoring Systems Laboratory in Las Vegas, Nevada (EMSL-LV), has carried out several
major environmental studies in which geostatistical evaluation was used as one of the main
guides for designing the monitoring approach and evaluating the collected data (Starks,
Sparks, and Brown, 1989; Starks, Brown, and Fisher, 1986; Flatman, 1984; U. S. EPA, 1984a,
1984b).
At the time of the 1983 protocol document, volatile organic chemicals (VOC’s) were
difficult
to sample in the soil environment due to the loss of the chemical during sampling and
analysis.
That situation still exists and is being addressed in a major research effort conducted by
the
EMSL-LV. Progress is being made, but an acceptable sampling technology has not been
recommended by the agency.
Soil gas sampling methods are being used to aid in identifying the location of plumes
generated by volatile pollutants. Field gas chromatographs are also available and are
being used to provide rapid, inexpensive data for refining sampling and remedial
strategies. These field analytical procedures are most appropriate in the exploratory
stage and in the cleanup of sites. |
|
|
