United States
                   Environmental Protection
Environmental Monitoring Systems  -
Las Vegas NV 89114
                   Research and Development
EPA-600/S4-83-040  Jan. 1
x>EPA         Project Summary
                   Characterization  of  Hazardous
                   Waste  Sites  - A Methods
                   Manual,  Volume  II, Available
                   Sampling  Methods
                   P.E. Ford, P.J. Turina, and D.E. Seely
                     This volume is a compilation of
                    methods and materials suitable to
                    address most needs that arise during
                    routine waste site and hazardous spill
                    investigations. It is part of a multivolume
                    manual developed by the U.S. Environ-
                    mental Protection Agency to serve a
                    wide variety of users as a source of
                    information, methods, materials and
                    references on the subject. This volume
                    is organized  by  media. After  a first
                    introductory chapter on general problems,
                    the second chapter addresses  solids
                    and provides eight detailed instructions
                    on sampling methods for soils, sludges
                    and sediments,  and bulk materials.
                    Chapter Three addresses liquids. Ten
                    methods are detailed for surface waters,
                    containerized liquids, and groundwater.
                    Gases, vapors, and aerosols are covered
                    in Chapter Four. Twelve methods are
                    presented for ambient  air, soil  gases
                    and vapors, and headspace gases. The
                    last chapter briefly discusses ionizing
                    radiation survey instruments.  Every
                    method is referenced, and a large
                    bibliography is provided. Appendices
                    are included  to  make  the volume a
                    useful field manual. They cover Sample
                    Containerization and  Preservation,
                    Equipment Availability and Fabrication,
                    Packing and  Shipping  Guidelines,
                    Document Control and Chain-of-Custody
                    Procedures, and Applicable Tables (of
                    statistics and  conversion factors). This
                    volume will be revised annually.
                     This Project Summary was developed
                    by EPA's Environmental Monitoring
                    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
  Investigations at hazardous waste and
environment-threatening spill sites place
more restrictive demands on personnel,
materials and methodologies than those
usually found  in routine environmental
surveys. As a result, traditional procedures
and protocols used for the acquisition of
environmental samples often fail to meet
the rigors and demands  required for
many hazardous waste sampling applica-
tions. Thus, the collection  of hazardous
waste samples will  frequently require
specialized equipment and protocols
either developed specifically for such
uses or modified from preexisting.materials
and/or techniques. Some important
considerations are:
   •  Methods and  materials must be
     suitable to a wide range of situations
     and applications  because of the
     unknown nature of many hazardous.
     waste investigations and environ-
     mental spill responses.
   • Hazardous wastes, by definition,
     are associated with both acute and
     chronic exposure to dangerous,.
     toxic  chemicals and this dictates
     that expeditious sample collection
     methods be used  to minimize
     personnel exposure.
   • Because of the nature of  the
     materials being sampled,  the
     option of using disposable sampling

      equipment must be considered
      because attempting cleanup efforts
      in the field can be impractical.
    • Hazardous waste site investigations
      and response actions at environ-
      ment-threatening  spills generally
      require some  level  of  hazard
      protection that may be cumbersome,
      limit the field of vision, or fatigue
      the sampler. Sample collection
      procedures must therefore be
      relatively simple to follow to
      expedite sample procurement and
      to reduce the chance of fatigue.
      Collection and monitoring equip-
      ment should be simple to operate,
      direct reading, and should not be

These and other factors associated with
the procurement of hazardous waste
samples need to be  addressed  in a
compilation  of practical, cost effective,
and reliable methods and procedures
capable of yielding representative samples
for a diverse number of potential parameters
and chemical  matrices.  These methods
must  be consonant with  a variety of
analytical considerations running the
gamut from gross compatibility analyses
(pH, flammability, water reactivity, etc.) to
highly sophisticated techniques capable
of resolution in the part per billion (ppb)

Method Selection Criteria
  Even  a  limited literature survey  will
disclose the  existence of a great number
of sampling  methods, all of which  have
certain merits that warrant consideration.
Therefore, selection criteria were chosen
on which to  base decisions for including
the sampling methods found  in  this
manual. The following  is a listing, not
necessarily in order of relative importance,
of these criteria:
    • Practicality
    • Representativeness
    • Economics
    • Simplicity or Ease of Operation
    • Compatibility with Analytical Con-
    • Versatility
    • Safety

Purpose and Objectives of
  The basic objective of any sampling pro-
gram  is  to  produce  a  set of samples
representative  of the  source under
investigation and suitable for subsequent
analysis. More specifically, the objective
of sampling hazardous wastes is to
acquire information  that will assist
investigators  in  identifying  unknown
compounds present and to assess the
extent to which these compounds have
become integrated into the surrounding
environment. Subsequently, this ac-
quired information may be used in future
litigations as well as to assist investigators
in the development of remedial actions.
  The term "sample" can most simply be
defined  as a  representative part  of the
object  to  be  analyzed. This definition
needs to be qualified further, however, by
the consideration of several criteria.
  Of utmost  importance is representa-
tiveness. To meet the requirement of re-
presentativeness, the sample needs to be
chosen  so that it possesses the same
qualities or properties as the material
under consideration. However, the sam-
ple  needs  only resemble the material to
the degree determined by the desired
qualities under investigation and the
analytical techniques used.
  Sample  size is also  an important
criterion to be considered. Sample size
must be carefully chosen with respect to
the physical  properties of the  entire
object  and the  requirements and/or
limitations  of the analytical procedure.
For example, although the entire contents
of an intact 55-gallon drum can certainly
be considered a representative sample of
the drum  material,  it is an impractical
sample because of its bulk. Alternatively,
too small  a sample size can be  just as
limiting, since representativeness and
analytical volume requirements might be
  A third  criterion for consideration is
maintenance of sample integrity. The
sample must retain the properties of the
parent object (at the time  of sampling)
through collection, transport, and delivery
to the analyst. Degradation or alteration of
the sample through  exposure  to air,
excess heat or cold, microorganisms, or
to contaminants from the container must
be avoided.
  Finally,  the number and/or the fre-
quency of subsamples  (e.g., samples
making up a composite) required and the
distribution of these subsamples  need to
be  considered.These criteria are  often
dictated by the nature of  the material
being sampled; that is, whether the
material is homogeneous or heterogeneous.
For example,  if a material is known to be
homogeneous, a  single sample  may
suffice to define its quality. However, if a
sample  is heterogeneous, a number of
samples collected at specified time inter-
vals or distances may be necessary to de-
fine the characteristics  of  the  subject
materials. In  addition, the nature of the
chemical parameters to be identified and
the way the analytical results will be used
are also important when the number
and/or frequency of the samples to be
collected are determined.

Types of Samples
  Before defining the general sample
types, the  nature of  the object  or
materials  under  investigation  must  be
discussed. Materials can be divided into
three basic groups as  outlined  in Figure
  Of  least  concern to the sampler are
homogeneous materials. These materials
are generally defined as having uniform
composition throughout. In this case, any
sample increment can be considered
representative of the  material. On the
other hand,  heterogeneous  samples
present problems to the sampler because
of changes in the quality of the material
over distance.
  When discussing types of samples, it is
important to distinguish between the type
of media to be sampled and the sampling
technique  that yields  a specific type  of
sample. In  relation to the media to be
sampled, two basic types of samples can
be considered: the environmental sample
and the hazardous sample.
  Environmental samples (ambient air,
soils, rivers, streams, or biota) are
generally dilute  (in terms of  pollutant
concentration) and usually do not require
the special handling procedures used for
concentrated wastes. However, in certain
instances, environmental samples can
contain elevated concentrations  of
pollutants and in such  cases would have
to be handled as hazardous samples.
  Hazardous  or concentrated samples
are those collected from  drums,  tanks,
lagoons, pits, waste piles, fresh spills,
etc.,  and require  special handling proce-
dures because of their potential toxicity or
hazard.  These samples can  be further
subdivided based on their  degree  of
hazard;  however, care should be taken
when handling and shipping any wastes
believed to be concentrated, regardless of
the degree.
  In general, two basic types of sampling
techniques are recognized, both of which
can be used for either environmental  or
concentrated samples.

Grab Samples
  A grab sample is defined as a discrete
aliquot representative of a  specific
location at a given point in time. The
sample is collected all at once and at one
particular point in the sample  medium.
The representativeness of such samples
is defined by the nature of the materials
being sampled. In general, as sources
vary over time and distance, the repre-

 No change of quality
throughout the material
               \                     \
            Discrete              Continuous
         Change of quality         Change of quality
      throughout the material   throughout the material
Discrete Changes
Continuous Changes
Well-mixed liquids
Well-mixed gases
Pure metals
Ore pellets
Crystallized rocks
Fluids or gases with gradients
Mixture of reacting compounds
Granulated materials with granules
much smaller than sample size
Figure 1.    Types of material
sentativeness of grab  samples  will

Composite Samples
  Composites are  nondiscrete samples
composed of more than one specific
aliquot collected at various sampling
locations and/or different points in time.
Analysis of this type of sample produces
an  average value and can in certain
instances be used as an alternative to
analyzing a number of individual grab
samples and calculating  an average
value.  It should be noted, however,  that
compositing can  mask  problems by
diluting isolated concentrations of some
hazardous compounds below detection
  For  sampling situations involving
hazardous wastes, grab sampling tech-
niques are generally preferred because
grab sampling minimizes the amount of
time sampling personnel  must be in
contact with  the wastes,  reduces risks
associated with compositing unknowns,
and  eliminates chemical  changes  that
might  occur due to compositing. Com-
positing is still often used for environ-
mental samples and may be used for
hazardous samples under certain condi-
tions.  For example, compositing of
hazardous waste is often performed (after
compatibility tests have been completed)
to determine an average value over  a
number of different locations (group of
drums). This procedure provides data that
can be useful by providing an average
concentration within a number of units,
can serve to keep analytical costs down
and can  provide information  useful to
transporters  and waste disposal opera-
           Sampling Plan
             Before any sampling activities are
           begun, it is imperative that the purpose
           and goals of a program and the equipment,
           methodologies, and  logistics to be used
           during the actual sampling be identified
           in the form of a work or sampling plan.
           This plan is developed when it becomes
           evident that a field investigation is
           necessary and  should  be initiated in
           conjunction with or immediately following
           the preliminary assessment. This plan
           should be clear and  concise and should
           detail the following basic components:
              • background information collected
                during the preliminary assessment;
              • objectives and goals of the investi-
              • sampling  methods to be used,
                including equipment needs, pro-
                cedures, sample containment, and
             • justification  for  selected methods
                and procedures;
             • sample locations, as well as, number
                and types of samples to be collected
               at each;
             • organization  of the investigative
             • safety  plan (includes safety equip-
               ment and decontamination pro-
               cedures, etc.);
             • transportation and shipping inform-
             • training information; and
             • additional site-specific information
               or requirements.

             Note that  this  list of  sampling plan
           components is by no means all inclusive
           and that additional elements  may be
added or altered depending on the
specific requirements of the field investi-
gation. It should also be recognized that
although a detailed sampling plan is quite
important, it  may be an impractical
undertaking in some instances. Emergency
responses to accidental spills would be a
prime example of such an instance where
time might prohibit the development of a
site-specific sampling plan.  In such a
case, the investigator would have to rely
on  general guidelines and  personal
judgment, and the sampling or response
plan might be simply a strategy based on
preliminary information and finalized on
site. In any event, a plan of action needs to
be developed, no matter how concise or
informal, to aid investigators in  main-
taining a logical and consistent order to
the implementation of their task. Plan-
ning and safety are discussed in detail in
Volumes I, IV and V.

Sampling Schemes
  The  manner in which samples are
selected  generally falls into one of (or a
combination of) the following categories.

Random Sampling
  Random sampling uses the theory of
random chance probabilities to choose
representative sample locations. Random
sampling is generally employed  when
little information exists concerning the
material, location, etc. It is most effective
when the population of available sampling
locations is large enough to lend statisti-
cal validity to the  random selection
process. Since one of the main difficulties
with random sampling deals with achiev-
ing a truly random sample, it is advisable
to use a table of random numbers to
eliminate or reduce bias (Appendix E).

Systematic  Sampling
  Systematic  sampling  involves the
collection of samples at predetermined,
regular  intervals.  It is  the most often
employed sampling  scheme;  however,
care must be exercised to avoid bias, if,
for example, there are periodic variations
in the material to be sampled such that
the systematic plan  becomes  partially
phased with these variations.
  A systematic sampling plan is often the
end  result  for approaches  that are
initiated as random due to the tendency of
investigators to subdivide a large sample
area into increments prior to randomizing.

Stratified Sampling
  Data and background information
made available from the preliminary site
survey, prior investigations conducted on
site  and/or experience with similar

situations can be useful in reducing the
number of samples needed to attain a
specified precision. Stratified sampling
essentially involves the division of the
sample population  into groups based on
knowledge of sample characteristics at
these  divisions. The purpose of the
approach is to increase the precision of
the estimates made by sampling. This
objective should be met if the divisions
are "selected in such a manner that the
units within  each division  are more
homogeneous than the total population."
The  procedure used basically  involves
handling  each  division  in a simple
random approach.

Judgment  Sampling
  A certain amount of judgment often
enters into any sampling approach used;
however, this practice should be avoided
whenever possible, especially if the data
generated are likely to be used for
enforcement purposes. Judgment ap-
proaches tend to allow investigator bias to
influence  decisions, and, if care is not
exercised, can lead to poor quality data
and improper conclusions. If judgment
sampling does become necessary, it is
advisable  that  multiple  samples  be
collected in order to add some measure of
Hybrid Sampling Schemes
   In reality, most sampling schemes
consist of a combination or hybrid of the
types previously described. For example,
when  selecting an appropriate plan for
sampling  drums at a  hazardous waste
'site, the drums might  be initially staged
based  on preliminary  information con-
cerning contents, program objectives,
etc. (judgment, stratified sampling), and
then sampled randomly within the
specified population  groups (random
sampling). Hybrid schemes are  usually
the method of choice as they can allowfor
greater diversity without compromising
the objectives of the program.

Multiple Samples
   Multiple samples need to be collected
at any time legal action is anticipated. It is
recommended that multiple samples be
collected whenever  possible. These
additional samples are essential to any
quality control aspects of the project and
may also assist in reducing costs associ-
ated with resampling  brought about by
container breakage, errors in the analytical
procedure, and data confirmation. The
following  is a list of the types of multiple
samples required.
Sample Blanks
  Sample blanks  are samples  of deio-
nized/distilled water,  rinsed collection
devices or containers, sampling media
(e.g., sorbent), etc. that are handled in the
same manner as  the sample and sub-
sequently analyzed to identify  possible
sources of contamination during collec-
tion, preservation, handling, or transport.

  Duplicates are  essentially identical
samples collected at the same time, inthe
same way, and contained, preserved, and
transported in the same  manner. These
samples  are often used to verify the
reproducibility of the data.

Split Samples
  Split samples  are duplicate  samples
given to the owner, operator, or person in
charge for separate analysis.

Spiked Samples
  Spiked samples are duplicate  samples
that have a known amount of a substance
of interest added to them. These  samples
are used to corroborate the  accuracy of
the analytical  technique and could be
used as an  indicator of  sample quality
change during shipment to the laboratory.

Document Control/Chain-of-
  Strict adherence to document and data
control procedures is essential from the
standpoint of good quality  assurance/
quality control and should be instituted as
routine in any hazardous waste investi-
gation. It becomes especially important
when collected data is used to support
enforcement litigations. All collected
information,  data, samples, and  docu-
ments  must therefore be accounted for
and  retrievable at any time during an
  The purpose of document control is to
ensure that  all project  documents be
accounted  for when the project is
complete. Types of documents considered
essential include maps, drawings, photo-
graphs,  project  work plans,  quality
assurance plans, serialized logbooks,
data sheets, coding forms,  confidential
information,  reports, etc.
  Chain-of-custody procedures  are ne-
cessary to document the sample identity,
handling and shipping procedures, and in
general  to  identify and  assure  the
traceability of generated samples. Custody
procedures trace the sample from collec-
tion, through any custody transfers, and
finally to the analytical facility at which
point internal laboratory procedures take
over. Chain-of-custody is also necessary
to document measures taken to prevent   i
and/or detect tampering with samples,
sampling equipment or the media to be
sampled. A detailed description of
Document Control/Chain-of-Custody
Procedures can be found in Appendix D.

      P. E. Ford. P. J. Turina. andD. E. Seelyare with GCA Corp., Bedford. MA 01730.
      Charles K. Fitzsimmons is the EPA Project Officer (see below).
      The complete report,  entitled "Characterization of Hazardous Waste Sites—A
        Methods Manual: Volume II. Available Sampling Methods," (Order No.  PB
        84-126 929; Cost: $20.50, 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 89114
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