ASTM D5956-96(2006)
(Guide)Standard Guide for Sampling Strategies for Heterogeneous Wastes (Withdrawn 2015)
Standard Guide for Sampling Strategies for Heterogeneous Wastes (Withdrawn 2015)
SIGNIFICANCE AND USE
This guide is suitable for sampling heterogeneous wastes.
The focus of this guidance is on wastes; however, the approach described in this guide may be applicable to non-waste populations, as well.
Sections 4-9 describe a guide for the sampling of heterogeneous waste according to project objectives. Appendix X1 describes an application of the guide to heterogeneous wastes. The user is strongly advised to read Annex A1 prior to reading and employing Sections 4-9 of this guide.
Annex A1 contains an introductory discussion of heterogeneity, stratification, and the relationship of samples and populations.
This guide is intended for those who manage, design, or implement sampling and analytical plans for the characterization of heterogeneous wastes.
SCOPE
1.1 This guide is a practical, nonmathematical discussion for heterogeneous waste sampling strategies. This guide is consistent with the particulate material sampling theory, as well as inferential statistics, and may serve as an introduction to the statistical treatment of sampling issues.
1.2 This guide does not provide comprehensive sampling procedures, nor does it serve as a guide to any specification. It is the responsibility of the user to ensure appropriate procedures are used.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
WITHDRAWN RATIONALE
This guide was a practical, nonmathematical discussion for heterogeneous waste sampling strategies. This guide was consistent with the particulate material sampling theory, as well as inferential statistics, and served as an introduction to the statistical treatment of sampling issues.
Formerly under the jurisdiction of Committee D34 on Waste Management, this guide was withdrawn in January 2015 in accordance with section 10.5.3.1 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D5956 − 96(Reapproved 2006)
Standard Guide for
Sampling Strategies for Heterogeneous Wastes
This standard is issued under the fixed designation D5956; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope composite only portions of the component samples. The
remainders of the component samples then can be archived for
1.1 This guide is a practical, nonmathematical discussion
future reference and analysis. This approach is particularly
for heterogeneous waste sampling strategies. This guide is
helpful when sampling is expensive, hazardous, or difficult.
consistent with the particulate material sampling theory, as
well as inferential statistics, and may serve as an introduction 2.1.5 correlation, n—the mutual relation of two or more
to the statistical treatment of sampling issues. things.
1.2 This guide does not provide comprehensive sampling 2.1.6 database, n—a comprehensive collection of related
procedures, nor does it serve as a guide to any specification. It data organized for quick access.
is the responsibility of the user to ensure appropriate proce-
2.1.6.1 Discussion—Database as used in this guide refers to
dures are used.
a collection of data generated by the collection and analysis of
more than one physical sample.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
2.1.7 data quality objectives (DQO), n— DQOs are quali-
responsibility of the user of this standard to establish appro-
tative and quantitative statements derived from the DQO
priate safety and health practices and determine the applica-
process describing the decision rules and the uncertainties of
bility of regulatory limitations prior to use.
the decision(s) within the context of the problem(s).
2.1.8 data quality objective process, n— a quality manage-
2. Terminology
ment tool based on the scientific method and developed by the
2.1 Definitions of Terms Specific to This Standard:
U.S. Environmental Protection Agency to facilitate the plan-
2.1.1 attribute, n—a quality of samples or a population.
ning of environmental data collection activities.
2.1.1.1 Discussion—Homogeneity, heterogeneity, and prac-
2.1.8.1 Discussion—The DQO process enables planners to
ticalhomogeneityarepopulationattributes.Representativeness
focus their planning efforts by specifying the use of the data
and intersample variance are sample attributes.
(the decision), the decision criteria (action level) and the
2.1.2 characteristic, n—a property of items, a sample or
decision maker’s acceptable decision error rates. The products
population that can be measured, counted, or otherwise ob-
of the DQO process are the DQOs.
served.
2.1.9 heterogeneity, n—the condition of the population un-
2.1.2.1 Discussion—A characteristic of interest may be the
der which items of the population are not identical with respect
cadmium concentration or ignitability of a population.
to the characteristic of interest.
2.1.3 component, n—aneasilyidentifieditemsuchasalarge
2.1.10 homogeneity, n—the condition of the population
crystal, an agglomerate, rod, container, block, glove, piece of
under which all items of the population are identical with
wood, or concrete.
respect to the characteristic of interest.
2.1.4 composite sample, n—a combination of two or more
2.1.10.1 Discussion—Homogeneity is a word that has more
samples.
thanonemeaning.Instatistics,apopulationmaybeconsidered
2.1.4.1 Discussion—When compositing samples to detect
homogeneous when it has one distribution (for example, if the
hot spots or whenever there may be a reason to determine
concentration of lead varies between the different items that
which of the component samples that constitute the composite
constitute a population and the varying concentrations can be
are the source of the detected contaminant, it can be helpful to
described by a single distribution and mean value, then the
population would be considered homogeneous). A population
containing different strata would not have a single distribution
This guide is under the jurisdiction of ASTM Committee D34 on Waste
Management and is the direct responsibility of Subcommittee D34.01.01 on
throughout, and in statistics, may be considered to be hetero-
Planning for Sampling.
geneous. The terms homogeneity and heterogeneity as used in
Current edition approved Oct. 1, 2006. Published October 2006. Originally
thisguide,however,reflecttheunderstandingmorecommonto
approved in 1996. Last previous edition approved in 2001 as D5956 – 96(2001).
DOI: 10.1520/D5956-96R06. chemists, geologists, and engineers. The terms are used as
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5956 − 96 (2006)
described in the previous definitions and refer to the similarity statistician. To avoid confusion, terms such as sample mass or
or dissimilarity of items that constitute the population.Accord- sample volume and number of samples are used instead of
ing to this guide, a population that has dissimilar items would sample size.
be considered heterogeneous regardless of the type of distri-
2.1.17 sample variance, n—a measure of the dispersion of a
bution.
set of results. Variance is the sum of the squares of the
individual deviations from the sample mean divided by one
2.1.11 item, n—a distinct part of a population (for example,
less than the number of results involved. It may be expressed
microscopic particles, macroscopic particles, and 20-ft long
2 2
as s 5 x 2x¯ / n21 .
( ~ ! ~ !
steel beams). i
2.1.18 sampling, n—obtaining a portion of the material
2.1.11.1 Discussion—The term component defines a subset
concerned.
of items. Components are those items that are easily identified
as being different from the remainder of items that constitute
2.1.19 stratum, n—a subgroup of a population separated in
the population.The identification of components may facilitate
space or time, or both, from the remainder of the population,
the stratification and sampling of a highly stratified population
being internally consistent with respect to a target constituent
when the presence of the characteristic of interest is correlated
or property of interest, and different from adjacent portions of
with a specific component.
the population.
2.1.19.1 Discussion—A landfill may display spatially sepa-
2.1.12 population, n—the totality of items or units under
rated strata since old cells may contain different wastes than
consideration.
new cells. A waste pipe may discharge temporally separated
2.1.13 practical homogeneity, n—the condition of the popu-
strata if night-shift production varies from the day shift. Also,
lation under which all items of the population are not identical.
a waste may have a contaminant of interest associated with a
For the characteristic of interest, however, the differences
particular component in the population, such as lead exclu-
between individual physical samples are not measurable or
sively associated with a certain particle size.
significant relative to project objectives.
2.1.19.2 Discussion—Highly stratified populations consist
2.1.13.1 Discussion—For practical purposes, the population
of such a large number of strata that it is not practical or
is homogeneous.
effective to employ conventional sampling approaches, nor
would the mean concentration of a highly stratified population
2.1.14 random, n—lack of order or patterns in a population
be a useful predictor (that is, the level of uncertainty is too
whose items have an equal probability of occurring.
great) for an individual subset that may be subjected to
2.1.14.1 Discussion—The word random is used in two
evaluation, handling, storage, treatment, or disposal. Highly
different contexts in this guide. In relation to sampling, random
stratified is a relative term used to identify certain types of
means that all items of a population have an equal probability
nonrandom heterogeneous populations. Classifying a popula-
of being sampled. In relation to the distribution of a population
tion according to its level of stratification is relative to the
characteristic, random means that the characteristic has an
persons planning and performing the sampling, their
equal probability of occurring in any and all items of the
experience, available equipment, budgets, and sampling objec-
population.
tives. Under one set of circumstances a population could be
2.1.15 representative sample, n—a sample collected in such considered highly stratified, while under a different context the
a manner that it reflects one or more characteristics of interest same population may be considered stratified.
(as defined by the project objectives) of a population from
2.1.19.3 Discussion—The terms stratum and strata are used
which it was collected. in two different contexts in this guide. In relation to the
population of interest, stratum refers to the actual subgroup of
2.1.15.1 Discussion—A representative sample can be (1)a
the population (for example, a single truck load of lead-acid
single sample, (2) a set of samples, or (3) one or more
batteries dumped in the northeast corner of a landfill cell). In
composite samples.
relation to sampling, stratum or strata refers to the subgroups
2.1.16 sample, n—a portion of material that is taken for
or divisions of the population as assigned by the sampling
testing or for record purposes.
team. When assigning sampling strata, the sampling team
2.1.16.1 Discussion—Sample is a term with numerous
should maximize the correlation between the boundaries of the
meanings. The scientist collecting physical samples (for
assigned sampling strata and the actual strata that exist within
example, from a landfill, drum, or waste pipe) or analyzing
the population. To minimize confusion in this guide, those
samples, considers a sample to be that unit of the population
strata assigned by the sampling team will be referred to as
collected and placed in a container. In statistics, a sample is
sampling strata.
consideredtobeasubsetofthepopulation,andthissubsetmay
consist of one or more physical samples. To minimize confu-
3. Significance and Use
sion the term physical sample is a reference to the sample held
3.1 This guide is suitable for sampling heterogeneous
in a sample container or that portion of the population that is
wastes.
subjected to in situ measurements. One or more physical
samples, discrete samples, or aliquots are combined to form a 3.2 The focus of this guidance is on wastes; however, the
composite sample. The term sample size has more than one approach described in this guide may be applicable to non-
meaning and may mean different things to the scientist and the waste populations, as well.
D5956 − 96 (2006)
3.3 Sections4–9 describe a guide for the sampling of neous populations are usually more difficult to sample. The
heterogeneouswasteaccordingtoprojectobjectives.Appendix increased difficulty in sampling nonrandom heterogeneous
X1 describes an application of the guide to heterogeneous populations is due to the existence of unidentified or numerous
wastes. The user is strongly advised to read AnnexA1 prior to strata, or both. If the existence of strata are not considered
reading and employing Sections4–9 of this guide. when sampling a nonrandom heterogeneous population, the
resulting data will average the measured characteristics of the
3.4 Annex A1 contains an introductory discussion of
individual strata over the entire population. If the different
heterogeneity, stratification, and the relationship of samples
strata are relatively similar in composition, then the mean
and populations.
characteristic of the population may be a good predictor for
3.5 This guide is intended for those who manage, design, or
portions of the population and will often allow the project-
implement sampling and analytical plans for the characteriza-
specific objectives to be achieved. As the difference in com-
tion of heterogeneous wastes.
position between different strata increases, average population
characteristics become less useful in predicting composition or
4. Sampling Difficulties
propertiesofindividualportionsofthepopulation.Inthislatter
case,whenpossible,itisadvantageoustosampletheindividual
4.1 There are numerous difficulties that can complicate
strata separately, and if an overall average of a population
efforts to sample a population. These difficulties can be
characteristic is needed, it can be calculated mathematically
classified into four general categories:
using the weighted averages of the sampling stratum means
4.1.1 Population access problems making it difficult to
(1).
sample all or portions of the population;
4.1.2 Sample collection difficulties due to physical proper-
5. Stratification
ties of the population (for example, unwieldy large items or
5.1 Strata can be thought of as different portions of a
high viscosity);
population, which may be separated in time or space with each
4.1.3 Planning difficulties caused by insufficient knowledge
portion having internally similar concentrations or properties,
regarding population size, heterogeneity of the contaminant of
which are different from adjacent portions of the population
interest, or item size, or a combination thereof; and,
(that is, concentrations/properties are correlated with space,
4.1.4 Budget problems that prevent implementation of a
time, component, or source). Fig. 1 is a graphical depiction of
workable, but too costly, sampling design.
different types of strata.
4.2 The difficulties included in the first three categories are
5.1.1 A landfill may display spatially separated strata since
a function of the physical properties of the population being
old cells may contain different wastes than new cells (stratifi-
sampled. The last sampling difficulty category is a function of
cation over space);
budget restraints that dictate a less-costly sampling approach
5.1.2 A waste pipe may discharge temporally separated
thatoftenresultsinareducednumberofsamplesandareduced
strata if night-shift production varies from the day shift
certainty in the estimates of population characteristics. Budget
(stratification over time);
restraints can make it difficult to balance costs with the levels
5.1.3 Lead-acid batteries will constitute a strata separate
of confidence needed in decision making. These difficulties
from commingled soil if lead is the characteristic of interest
may be resolved by changing the objectives or sampling/
(stratification by c
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