United States
Environmental Protection
Agency
Environmental Monitoring
Systems Laboratory
Las Vegas NV 89193-3478
Research and Development
EPA/600/S4-89/008 Sept. 1989
Project Summary
The Use of Industrial Hygiene
Samplers for Soil-Gas
Measurement
H. B. Kerfoot and C. L. Mayer
This report describes a field eval-
uation of a passive-sampling tech-
nique for soil-gas surveying. The sys-
tem uses a sampler, consisting of an
industrial hygiene organic vapor
monitor inside a metal sampling man-
ifold, buried at a depth of approx-
imately 0.3 meters (1 foot). Samplers
are analyzed off site by NIOSH
Method P&CAM 127.
For passive sampling in general
and this technique in particular, an
absorbent sampler is buried at a
shallow depth and allowed to collect
VOCs from the soil atmosphere. After
a set time (8 hours to several weeks),
the sampler is retrieved, sealed im-
mediately, and transported to a labor-
atory for analysis. Analysis results
indicate the identity and concentra-
tion of VOCs collected by the sam-
pler. The main advantage of passive
sampling lies in the simplicity of field
operations i.e. field support (sup-
plies, personnel, and equipment) is
much less costly than for grab sam-
pling, and equipment problems are
virtually non-existent. The disadvan-
tages associated with passive sam-
pling are that results are not available
for days to weeks and that deep
sampling is difficult without more
elaborate equipment.
This Project Summary was devel-
oped by EPA's Environmental Mon-
itoring Systems Laboratory, Las Vegas,
NV, to announce key findings of the
research project that is fully
documented in a separate report of
the same title (see Project Report
ordering information at back).
In the last few years, soil-gas meas-
urement has emerged as a cost-effective
reconnaissance technique for preliminary
site characterizations. It provides rapid
inexpensive guidance in selecting the
most appropriate locations for ground-
water sampling.
This report describes a field evaluation
of a passive-sampling technique for soil-
gas surveying. The system uses a sam-
pler, consisting of an industrial hygiene
organic vapor monitor inside a metal
sampling manifold, buried at a depth of
approximately 0.3 meters (1 foot).
Samplers are analyzed off site by NIOSH
Method P&CAM 127.
For passive sampling in general and
this technique in particular, an absorbent
sampler is buried at a shallow depth and
allowed to collect VOCs from the soil at-
mosphere. After a set time (8 hours to
several weeks), the sampler is retrieved,
sealed immediately, and transported to a
laboratory for analysis. Analysis results
indicate the identity and concentration of
VOCs collected by the sampler. The
mam advantage of passive sampling lies
in the simplicity of field operations i.e.
field support (supplies, personnel, and
equipment) is much less costly than for
grab sampling, and equipment problems
are virtually non-existent. The disadvan-
tages associated with passive sampling
are that results are not available for days
to weeks and that deep sampling is
difficult without more elaborate equip-
ment.
This passive-sampling system was
field tested at the Pittman Lateral near
Henderson, Nevada where unconfined
ground water occurs at 1.5 to 4.3 meters
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(5 to 14 feet) beneath the ground surface.
Two distinct ground-water volatile organic
contaminant plumes exist at the site: one
is primarily chloroform, and the other,
benzene and chlorobenzene. Both
plumes have been delineated by repeat-
ed sampling and analysis of ground water
from monitoring wells located at 61-meter
(200-foot) intervals along a line
perpendicular to the direction of ground
water flow.
Experimental Results
The passive sampler consisted of an
activated carbon organic vapor monitor
(No. 3500, 3M, St. Paul, Minnesota)
suspended in a sampling manifold made
from a one-quart can. Samplers were
placed in holes 0.3 meters (1 foot) deep,
the holes were backfilled, and the
samplers were retrieved and sealed after
a 2-week exposure period.
This sampling method successfully de-
lineated a chloroform soil-gas plume
above ground water contaminated with
chloroform at concentrations up to 800 ug
per liter. The chloroform soil-gas con-
centrations in this study correlate well
with ground-water chloroform concentra-
tions and with soil-gas concentrations
measured in an earlier grab-sample/on-
site analysis study (Fig. 1). Analysis from
the samplers above the benzene/chloro-
benzene ground-water plume did not
show detectable amounts of either
compound. This result confirms the
results obtained with the grab-sample
study performed at the site.
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A Passive samp/ing soil-gas chloroform concentrations
B Ground-water chloroform concentrations
C: Grab sampling soil-gas chloroform concentrations
Figure 1. Grab sample and passive-sampling soil-gas chloroform ronct'inr,itiori'i iii'il i
water chloroform concentrations
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H. B. Kerfoot and C. L Mayer are with Lockheed Engineering Management
Services Company, Las Vegas, NV 89779.
Philip B. Durgin is the EPA Project Officer (see below).
The complete report, entitled "The Use of Industrial Hygiene Samplers for Soil-Gas
Measurement," (Order No. PS 89-766 359IAS; Cost: $13.95, subject to change)
will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Monitoring Systems Laboratory
U.S. Environmental Protection Agency
Las Vegas, NV 89193-3478
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
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Penalty for Private Use $300
EPA/600/S4-89/008
AGEBCY
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