OSWER Directive 9360.4-14
EPA 540/R-95/141
PB96-963207
December 1995
SUPERFUND PROGRAM
REPRESENTATIVE SAMPLING GUIDANCE
VOLUME 4: WASTE
Interim Final
Environmental Response Team
Office of Emergency and Remedial Response
Office of Solid Waste and Emergency Response
U.S. Environmental Protection Agency
Washington, DC 20460
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Notice
This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved
for publication.
The policies and procedures established in this document are intended solely for the guidance of government
personnel, for use in the Superfund Program. They are not intended, and cannot be relied upon, to create any rights,
substantive or procedural, enforceable by any party in litigation with the United States. The Agency reserves the right
to act at variance with these policies and procedures and to change them at any time without public notice.
For more information on Waste Sampling procedures, refer to the Compendium ofERT Waste Sampling Procedures,
OSWER Directive 9360.4-07, EPA/540/P-91/008. Topics covered in this compendium include: sampling equipment
decontamination; drum sampling; tank sampling; chip, wipe, and sweep sampling; and waste pile sampling.
Please note that the procedures in this document should only be used by individuals properly trained and certified
under a 40-hour hazardous waste site training course that meets the requirements set forth in 29 CFR 1910.120(e)(3).
It should not be used to replace or supersede any information obtained in a 40-hour hazardous waste site training
course.
Questions, comments, and recommendations are welcomed regarding the Superfund Program Representative
Sampling Guidance, Volume 4 Waste. Send remarks to:
Mr. William A. Coakley
Chairman, Representative Sampling Committee
U.S. EPA-ERT
Rantan Depot - Building 18, MS-101
2890 Woodbridge Avenue
Edison, NJ 08837-3679
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Disclaimer
This document has been reviewed under U.S. Environmental Protection Agency policy and approved for publication.
Mention of trade names or commercial products does not constitute endorsement or recommendation for use.
The following trade names are mentioned in this document:
Drager is a trademark of National Draeger, Inc. of Pittsburgh, Pennsylvania
Sensidyne is a trademark of Sensidyne, Inc.
MSA is a trademark of Mine Safety Appliance Company of Pittsburgh, Pennsylvania
Teflonฎ and Tyvekฎ are registered trademarks of E.I. DuPont de Nemours and Company of Wilmington, Delaware
in
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Contents
Notice ii
Disclaimer iii
List of Figures vii
List of Tables vii
1.0 INTRODUCTION 1
1.1 OBJECTIVE AND SCOPE 1
1.2 CHARACTERISTICS OF WASTE 1
1.3 REPRESENTATIVE SAMPLING OBJECTIVES 1
1.4 CONCEPTUAL SITE MODEL 3
1.5 EXAMPLE SITE 5
2.0 SAMPLING DESIGN 6
2.1 INTRODUCTION 6
2.2 SAMPLING PLAN 6
2.2.1 Historical Data Review 7
2.2.2 Site Reconnaissance 7
2.2.3 Physiographic and Other Factors 7
2.3 WASTE SAMPLE TYPES 7
2.3.1 Grab Sample 7
2.3.2 Composite Sample 8
2.4 WASTE TYPES 8
2.5 WASTE CHARACTERISTICS 9
2.5.1 Homogeneity 9
2.5.2 Physical State 9
2.5.3 Chemical Stability 9
2.5.4 Particle Size (solids) 9
2.5.5 Viscosity (liquids) 10
2.6 WASTE SOURCES 10
2.6.1 Containerized Waste 10
2.6.2 Uncontainerized Waste 11
2.6.3 Surfaces and Debris 11
2.7 QUALITY ASSURANCE CONSIDERATIONS 11
2.8 DATA QUALITY OBJECTIVES 12
2.9 FIELD ANALYTICAL SCREENING AND GEOPHYSICAL TECHNIQUES 12
2.10 ANALYTICAL PARAMETERS AND METHODS 12
2.11 REPRESENTATIVE SAMPLING APPROACHES 13
2.11.1 Judgmental Sampling 13
2.11.2 Random Sampling 13
2.11.3 Systematic Grid Sampling 14
2.11.4 Systematic Random Sampling 14
2.11.5 Transect Sampling 14
2.12 SAMPLING LOCATIONS AND NUMBER 15
2.13 EXAMPLE SITE 16
2.13.1 Background 16
2.13.2 Site Entry 16
2.13.3 Site Inventory 17
IV
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2.13.4 Selecting Analytical Parameters 18
3.0 FIELD ANALYTICAL SCREENING AND SAMPLING EQUIPMENT 20
3.1 INTRODUCTION 20
3.1.1 Combustible Gas Indicator 20
3.1.2 Radiation Screening Instruments 20
3.1.3 Flame lonization Detector 20
3.1.4 Photoionization Detector 21
3.1.5 Colorimetric Tubes 21
3.1.6 Hazard Categorization 21
3.1.7 Immunoassay Tests 22
3.1.8 X-Ray Fluorescence 22
3.1.9 Gas Chromatograph 22
3.2 SAMPLING EQUIPMENT 23
3.2.1 Drum Openers 23
3.2.2 Liquid Samplers 23
3.2.3 Sludge Samplers 24
3.2.4 Solids Samplers 25
3.3 EXAMPLE SITE 26
3.3.1 Drum Screening and Sampling Equipment 26
3.3.2 Plating Vat Screening and Sampling Equipment 26
3.3.3 Waste Pile Screening and Sampling Equipment 26
3.3.4 Impoundment Screening and Sampling Equipment 27
3.3.5 Transformer Screening and Sampling Equipment 27
4.0 FIELD SAMPLE COLLECTION AND PREPARATION 29
4.1 INTRODUCTION 29
4.2 SAMPLE VOLUME 29
4.3 SOURCE SAMPLING 29
4.3.1 Drum Sampling 29
4.3.2 Bulk Storage Tank and Transformer Sampling 30
4.3.3 Lab Pack Sampling 30
4.3.4 Surface Impoundment Sampling 30
4.3.5 Waste Pile Sampling 30
4.3.6 Surface Sampling 31
4.3.7 Debris Sampling 32
4.3.8 Compressed Liquid/Gas Cylinders 32
4.4 SAMPLE PREPARATION 32
4.4.1 Removing Extraneous Material 33
4.4.2 Homogenizing 33
4.4.3 Splitting 33
4.4.4 Final Preparation 33
4.5 EXAMPLE SITE 34
4.5.1 Source Sampling 34
4.5.2 Sample Preparation 34
5.0 QUALITY ASSURANCE/QUALITY CONTROL 36
5.1 INTRODUCTION 36
5.2 DATA CATEGORIES 36
5.3 SOURCES OF ERROR 36
5.3.1 Sampling Design 36
5.3.2 Sampling Methodology 37
5.3.3 Sample Heterogeneity 37
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5.3.4 Analytical Procedures 37
5.4 QA/QC SAMPLES 37
5.4.1 Field Replicate Samples 38
5.4.2 Collocated Samples 38
5.4.3 Background Samples 38
5.4.4 Performance Evaluation/Laboratory Control Samples 38
5.4.5 Matrix Spike/Matrix Spike Duplicate Samples 38
5.4.6 Rinsate Blank Samples 39
5.4.7 Field Blank Samples 39
5.4.8 Trip Blank Samples 39
5.4.9 Laboratory Duplicate Samples 39
5.5 EVALUATION OF ANALYTICAL ERROR 39
5.6 CORRELATION BETWEEN FIELD SCREENING RESULTS AND
LABORATORY RESULTS 39
5.7 EXAMPLE SITE 40
5.7.1 QA Objectives 40
5.7.2 Sources of Error 40
5.7.3 Field QA/QC Samples 40
5.7.4 Laboratory QA/QC Samples 41
6.0 DATA PRESENTATION AND ANALYSIS 42
6.1 INTRODUCTION 42
6.2 DATA POSTING 42
6.3 CROSS-SECTION/FENCE DIAGRAMS 42
6.4 CONTOUR MAPPING 42
6.5 STATISTICAL GRAPHICS 42
6.6 RECOMMENDED DATA INTERPRETATION METHODS 43
6.7 EXAMPLE SITE 43
Appendix A EXAMPLE OF FLOW DIAGRAM FOR CONCEPTUAL SITE MODEL 47
References 50
VI
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List of Figures
1 Conceptual Site Model 4
2 Random Sampling 13
3 Systematic Grid Sampling 14
4 Systematic Random Sampling 15
5 Transect Sampling 15
6 ABC Plating Site Sketch 17
7 Example of a Drum Inspection Log 19
8 Example of a Hazard Categorization Data Sheet 28
9 Posted Total Chromium Data for Impoundment No. 1 44
A-l Migration Routes of a Gas Contaminant 47
A-2 Migration Routes of a Liquid Contaminant 48
A-3 Migration Routes of a Solid Contaminant 49
List of Tables
1 ABC Plating Sample Log 35
2 Haz-Cat Results -- ABC Plating Site 45
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1.0 INTRODUCTION
1.1 OBJECTIVE AND SCOPE
This is the fourth volume in a series of guidance
documents that assist Superfund Program Site
Managers, On-Scene Coordinators (OSCs), Remedial
Project Managers (RPMs), and other field staff in
obtaining representative samples at Superfund sites.
The objective of representative sampling is to ensure
that a sample or a group of samples accurately
characterizes site conditions. The representative
sampling principles discussed in this document are
applicable throughout the Superfund Program. The
following chapters will help field personnel to assess
available information, select an appropriate sampling
approach, select and utilize field analytical screening
methods and sampling equipment, incorporate suitable
types and numbers of quality assurance/quality control
(QA/QC) samples, and interpret and present the site
analytical data.
As the Superfund Program has developed, the
emphasis of this response action has expanded beyond
addressing emergency response and short-term
cleanups. Each planned response action must
consider a variety of sampling objectives, including
identifying threat, delineating sources of
contamination, and confirming the achievement of
clean-up standards. Because many important and
potentially costly decisions are based on the sampling
data, Site Managers and other field personnel must
characterize site conditions accurately. To that end,
this document emphasizes the use of cost-effective
field analytical screening techniques to characterize
the site and aid in the selection of sampling locations.
1.2 CHARACTERISTICS
WASTE
OF
Waste, in general terms, can include solid, liquid, and
sludge material typically generated as a by-product of
an industrial process. Assume that containerized
wastes comprise high concentrations of hazardous
substances, unless clearly indicated otherwise through
previous sample analysis or other reliable
documentation. Waste samples are often of high
concentration and phased (e.g., light liquid, dense
liquid, and sludge), an important point to consider
when developing a sampling strategy. This document
specifically addresses the sampling of wastes typically
found in drums, tanks, lab packs, transformers,
impoundments, waste piles, and on surfaces.
The National Oil and Hazardous Substances Pollution
Contingency Plan (NCP) definition for a hazardous
substance includes "...any substance designated
pursuant to section 311 (b)(2)(A) of the Clean Water
Act; any element, compound, mixture, solution, or
substance designated pursuant to Section 3001 of the
Solid Waste Disposal Act (but not including any
waste the regulation of which under the Solid Waste
Disposal Act has been suspended by an Act of
Congress); any hazardous air pollutant listed under
Section 112 of the Clean Air Act; and any imminently
hazardous chemical substance or mixture with respect
to which the EPA Administrator has taken action
pursuant to Section 7 of the Toxic Substances Control
Act. The term does not include petroleum including
crude oil or any fraction thereof which is not
otherwise specifically listed or designated as a
hazardous substance..., and the term does not include
natural gas, natural gas liquids, liquified natural gas,
or synthetic gas usable for fuel (or mixtures of natural
gas and such synthetic gas)." Pursuant to 40 CFR
261, Subpart C, a waste is considered hazardous if it
exhibits any of the following characteristics:
ignitability, corrosivity, reactivity, ortoxicity; or if it
is a listed hazardous waste under 40 CFR 261.30,
Subpart D. Asbestos and "mixed" waste (having
radioactive and hazardous waste components), while
included in this definition, require specialized
sampling methods and techniques and will not be
addressed in this document.
1.3 REPRESENTATIVE SAMPLING
OBJECTIVES
Representative sampling applies to all phases of a
Superfund response action. Representative sampling
objectives for waste include:
Identify the waste, including composition and
characteristics, and determine if it is hazardous.
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Determine if there is an imminent or substantial
threat to public health or welfare or the
environment.
Determine the need for long-term action.
Develop containment and control strategies.
Evaluate appropriate disposal/treatment options.
Verify treatment goals or clean-up levels.
Determine Hazard and Identify Waste
One of the first objectives during a response action at
a site is to determine the presence, identity, and
potential threat of any hazardous materials. Use field
screening techniques (discussed in Chapter 3) for
rapid detection of wastes. Upon confirming the
presence of hazardous materials, sample and/or
continue screening to identify their compositions and
determine their concentrations.
In addition to characterizing the waste sufficiently,
conduct compatibility tests to help classify waste by
composition and other physical characteristics into
compatible waste streams (e.g., acid, base, or
oxidizer). This will ensure safer handling, staging,
bulking, storage, and transportation of wastes both on
and off site.
Establish Threat
Establishing threat to the public or environment is a
primary objective during a response action. The data
obtained from characterizing the waste will help the
Site Manager to determine whether an imminent or
substantial threat exists and whether a removal action
or other response action is necessary. The type and
degree of threat determines the rate at which a
response action is taken.
Determine Need for Long-Term Action
Site conditions may establish a long-term threat that
is not imminent or substantial. Characterization of the
waste can assist the Site Manager in setting a priority
for long-term remediation evaluation and response.
Waste characterization data are required to evaluate
the site under the Hazard Ranking System and to
identify sites eligible for inclusion on the National
Priorities List (NPL). The NPL is the ranking list of
those sites at highest national priority for long-term
evaluation and remediation.
Develop Waste Containment and Control
Strategies
Once the chemical constituents and threat have been
established, many strategies for waste containment
and control are available to the Site Manager.
Analytical data indicating the presence of chemical
hazards are not in themselves sufficient to select a
containment or control strategy. Site reconnaissance
and historical site research provide information on site
conditions and the physical state of the waste sources;
waste containment and control strategies are largely
determined by this information. For example, site
security measures (such as erecting a fence) may be
sufficient to stabilize a site containing intact drums of
solvents, and overpacking may be sufficient to contain
a corroded drum of organophosphate pesticides.
Unstable or explosive wastes, such as picric acid, may
require immediate removal by demolition experts.
Identify Available Treatment/Disposal Options
The site contaminants should be identified, quantified,
and compared to selected action levels. Where
regulatory action levels do not exist, site-specific
clean-up levels are determined by the EPA Region
(often in consultation with the Agency for Toxic
Substances and Disease Registry (ATSDR)). If action
levels are exceeded, a series of chemical and physical
tests may be required to evaluate possible treatment
and/or disposal options. Each treatment or disposal
method has a corresponding set of waste parameters
that must be evaluated, e.g., ash content, British
thermal unit (BTU) value, total metals concentration,
total organic halides, cyanide, total chlorine and NOx
are minimum requirements for incineration. It is
important to test for treatment/disposal parameters as
early as possible during the site assessment and
characterization procedure. Relatively inexpensive
tests such as total organic carbon (TOC), BTU, and
pH should be considered early in the response action
in order to contribute to later treatability studies. The
test results will ultimately help to determine the most
appropriate treatment or disposal option for meeting
regulatory requirements.
Verify Treatment Goals or Clean-up Levels
After treatment or disposal, representative sampling
results should either confirm that the response actions
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have met the site-specific treatment goals or clean-up
levels, or indicate that further treatment or removal is
necessary. Refer to the Representative Sampling
Guidance, Volume 1 Soil, OSWER Directive
9360.4-10, for guidelines on soil sample collection
and preparation for confirming cleanup.
Sampling to verify cleanup requires careful
coordination with demobilization activities. After
treatment of one area on a site, verification sampling
can begin in that area by using field screening and on-
site analysis. Meanwhile, other areas can be treated.
Lab confirmation of the screening performed in the
treated areas can help ensure accuracy of screening for
subsequent areas to meet QA objectives (as discussed
in Section 5.2).
1.4 CONCEPTUAL SITE MODEL
A conceptual site model is a useful tool for selecting
sampling locations. It helps ensure that sources,
pathways, and receptors throughout the site have been
considered before sampling locations are chosen. The
conceptual model assists the site manager in
evaluating the interaction of different site features.
Risk assessors use conceptual models to help plan for
risk assessment activities. Frequently, a conceptual
model is created as a site map (see Figure 1) or it may
be developed as a flow diagram which describes
potential migration of contaminants to site receptors
(see Appendix A).
A conceptual model follows contaminants from their
sources, to pathways (e.g., air, surface water), and
eventually to the assessment endpoints. Consider the
following when creating a conceptual model:
The state(s) of each contaminant and its potential
mobility
Site topographical features
Meteorological conditions (e.g., wind
direction/speed, average precipitation,
temperature, humidity)
Human/wildlife activities on or near the site
The conceptual site model on the next page is an
example created for this document. The model assists
in identifying the following site characteristics:
Potential Sources'.
Site (waste pile, lagoon); drum dump; sewage plant
discharge
Potential Migration Pathways'.
Soil Leachate from the waste pile or drum dump;
soil in direct contact with solids in the waste pile or
drum dump
Surface Water Liquid waste from the lagoon or
sewage plant discharge (into the lake)
Sediments Liquid waste from the lagoon or sewage
plant discharge (into the lake)
Air Release of vapors/particulates from the waste
pile, drum dump or lagoon
Potential Exposure Routes'.
Ingestion Particles from the waste pile or drum
dump; liquid from the lagoon or lake (from sewage
plant discharge)
Inhalation Vapors from the waste pile, drum dump,
lagoon, or lake (sewage plant discharge)
Absorption/direct contact Contact with the waste
pile, drum dump, lagoon, or lake (sewage plant
discharge)
Potential Receptors of Concern (and associated
potential exposure sources)'.
Human Population
Residents/Trespassers:
Soil Leachate from the drum dump; direct
contact with soil from solids in the drum dump
Surface water Liquid waste from the lagoon into
the river or sewage plant discharge into the lake
Air Vapors/particulates from the waste pile,
drum dump, lagoon, or lake (sewage plant
discharge)
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Workers/Trespassers:
Soil Leachate from the waste pile; direct
contact with soil from solids in the waste pile
Surface water -- Liquid waste in the lagoon or
associated with the sewage plant discharge
Air Vapors/particulates from the waste pile,
drum dump, lagoon, or sewage plant discharge
Biota
Threatened or endangered species or human food
chain organisms known to frequent areas near the
waste pile, drum dump, lagoon, or lake (sewage
plant discharge)
Preliminary site information may provide the
identification of the contaminant of concern and the
level of the contamination. A sampling plan should
be developed based upon the selected receptors of
concern and the suspected sources and pathways. The
model may assist in the selection of on-site and off-
site sampling locations.
1.5 EXAMPLE SITE
An example site presented at the end of each chapter
illustrates the development of a representative waste
sampling plan that meets Superfund Program
objectives for an early action.
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2.0 SAMPLING DESIGN
2.1 INTRODUCTION
There is no universal sampling method for
characterizing wastes because site characteristics vary
widely. The sampling methods and equipment must
be suited to the specific sampling situation. A
properly developed waste sampling design defines the
sampling purpose, protects site worker health and
safety, effectively utilizes resources, and minimizes
errors. The sampling design will vary according to
the type of waste sampled (including type of
containers or sources), and the characteristics of the
site. When developing a sampling design, consider:
prior actions at the site (e.g., sampling practices,
compliance inspections); properties and characteristics
of the wastes sampled; site waste sources (e.g.,
impoundments, waste piles, drums); topographic,
geologic, hydrologic, and meteorologic conditions of
the site; and flora, fauna, and human populations in
the area.
Waste material may be liquid, solid, or sludge, and
may be contained in drums, tanks, waste piles, surface
impoundments, on surfaces (e.g., building structures,
floors, equipment), in lab packs, or other sources.
Sampling each waste stream may require a variety of
sampling techniques, equipment, sample packaging,
and sample analyses.
2.2 SAMPLING PLAN
Many site-specific factors are important in the
development of a good sampling plan, including: data
use and quality assurance objectives; sampling
equipment; sampling design; standard operating
procedures (SOPs); field analytical screening;
analytical method selection; decontamination; sample
handling and shipment; and data validation.
The U.S. EPA Quality Assurance Sampling Plan for
Environmental Response (QASPER) was designed to
develop sampling plans for response actions.
QASPER is menu-driven software which prompts the
user to input background information and to select
prescribed parameters for development of a site-
specific sampling plan. It also gives the user access
to any previously developed site-specific sampling
plans.
The following procedures are recommended for
developing a thorough waste sampling plan. Many
steps can be performed concurrently, and the sequence
is flexible.
Review the history of the site, including regulatory
and reported spill history; note current and former
locations of buildings, tanks, and process, storage,
and disposal areas.
Perform a site reconnaissance; categorize
physical/chemical properties and hazardous
characteristics of materials involved.
Identify topographic, geologic and hydrologic
characteristics of the site including surface water,
groundwater, and soil characteristics, as well as
potential migration pathways and receptors.
Determine geographic and demographic
information, including population size and its
proximity to the site (e.g., public health threats,
source of drinking water); identify threatened
environments (e.g., potentially contaminated
wetlands or other sensitive ecosystems).
Select sampling strategies, considering field
analytical screening and statistical applications,
when appropriate.
Determine data quality and quality assurance
objectives for field analytical screening, sampling,
and analysis. As the extent of contamination
becomes quantified, the sampling plan can be
modified to better assess sampling objectives
throughout the action.
It is recognized that many of these steps (described in
detail below) would not be applicable during a classic
emergency response because of the lack of advance
notice. Emergency response sampling nevertheless
requires good documentation of sampling events.
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2.2.1 Historical Data Review
The first step in developing a sampling plan is a
review of historical site data, examining past and
present site operations and disposal practices to
provide clues on possible site contamination.
Available sources of information include: federal,
state and local agencies and officials; federal, state,
and local agency files (e.g., site inspection reports and
legal actions); deed or title records; current and
former facility employees; potentially responsible
parties (PRPs); local residents; and facility records or
files.
A review of previous sampling information should
include sampling locations, matrices, methods of
collection and analysis, and relevant contaminant
concentrations. Assess the reliability and usefulness
of existing analytical data, including those which are
not substantiated by documentation or QA/QC
controls, but which may still illustrate general site
trends.
Collect information that describes specific chemical
processes, raw materials used, products and wastes,
and waste storage and disposal practices. Review any
available site maps, facility blueprints, and historical
aerial photographs detailing past and present storage,
process, and waste disposal locations. County
property and tax records and U.S. Geological Survey
(USGS) topographic maps are useful sources of
information on the site and its surroundings.
2.2.2 Site Reconnaissance
A site reconnaissance can be conducted at an earlier
date or immediately prior to sampling activities. It
allows field personnel to assess site conditions,
evaluate areas of potential contamination, evaluate
potential hazards associated with sampling, and
finalize a sampling plan. Site reconnaissance
activities include: observing and photographing the
site; noting site access routes and potential evacuation
routes; noting potential safety hazards; recording label
information from drums, tanks, or other containers;
mapping process and waste disposal areas such as
landfills, impoundments, and effluent pipes; making
an inventory of the wastes on site; mapping potential
contaminant migration routes such as drainage,
streams, and irrigation ditches; noting the condition of
animals and/or vegetation; and noting topographic
and/or structural features. Field personnel should use
appropriate personal protective equipment (PPE) when
engaged in any site activities.
2.2.3 Physiographic and Other
Factors
Other procedures, such as determining data quality
and QA/QC objectives, utilizing field analytical
screening techniques, identifying topographic,
geologic and hydrologic characteristics, and
determining geographic and demographic information
are important steps of an overall sampling plan. Field
analytical screening techniques and equipment are
discussed in Chapter 3; QA objectives are discussed
in Chapter 5. Since this document specifically
pertains to waste sampling, the remaining procedures
listed above will not be addressed in detail here.
(Please refer to the Representative Sampling
Guidance, Volume 1 Soil, OSWER Directive
9360.4-10.) The U.S. EPA is currently developing an
ecological sampling guidance document that will
contain a detailed checklist for collecting ecological
data.
2.3 WASTE SAM RLE TYPES
Design sampling procedures to match sampling
objectives. The type of sample collected may depend
on suspected waste types and characteristics; size and
accessibility of waste containers, impoundments and
other media; target analytes; and health and safely
requirements.
The following section describes and gives examples of
the two types of waste samples.
2.3.1 Grab Sample
A grab sample is a discrete aliquot collected from one
specific sampling location at a specific point in time,
and may be considered representative of a
homogeneous and stable waste. When obtaining grab
samples from containers or from an impoundment
having stratified layers, sample each phase or stratum
separately; the separate aliquots are representative of
their respective stratum. When sampling stratified
sources, determine as many properties of the wastes as
possible through historical data and site
reconnaissance prior to sampling, and use caution
because the individual phase components may be
more concentrated than the original waste material.
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2.3.2 Composite Sample
A composite sample is a non-discrete sample
composed of two or more equal aliquots collected at
various sampling points or times. There are four types
of composite samples: areal, vertical, flow
proportional, and time. An areal composite is
comprised of individual aliquots collected over a
defined area (e.g., surface of a waste pile). It is made
up of aliquots of equal volume, each collected in an
identical manner at the same horizon (depth). A
vertical composite is composed of individual aliquots
collected at different depths but along the same
vertical line (e.g., borehole). It is made up of aliquots
of equal volume which are collected in an identical
manner. A flow proportional composite is a sample
collected proportional to the flow rate during the
compositing period by either a time-varying/constant
volume or time-constant/varying volume method. A
time composite is composed of a varying number of
discrete, equal-volume aliquots collected at equal time
intervals during the compositing period. (Both flow
and time composite samples are appropriate for
sampling wastewater or streams.)
By design, composite samples reflect an "average"
concentration within the composite area, flow, or
interval. Compositing is appropriate when
determining the general characteristics or the
representativeness of certain sources (e.g., a waste
pile or impoundment) when considering methods of
treatment or disposal. When compositing samples
from a waste stream, note that resulting concentrations
are representative of the waste stream's average
concentration, but not of discrete areas within the
waste stream.
Composite sampling should be performed only on like
waste streams. Do not composite dissimilar waste
streams or waste sources (e.g., drums with unknown
contents or dissimilar materials) because of health and
safety risks associated with possible reactions; in
addition, the resulting sample will not define or
represent the origin of the mixed contaminants.
Composite aliquots from tanks, drums, or other
containers only after adequate hazardous
characterization screening to prevent mixing of
incompatible wastes.
A result of sample compositing is the dilution of high
concentration aliquots. To compensate for dilution,
reduce the applicable detection limits accordingly. If
the composite value is to be compared to a selected
action level, then the action level must be divided by
the number of aliquots that make up the composite in
order to determine the appropriate detection limit. For
example, if the action level for a particular substance
is 40 ppb, a detection limit of 10 ppb should be used
when analyzing a 4-aliquot composite.
When compositing waste, four aliquots per sample are
recommended because two ounces of each aliquot can
be added to an 8-ounce (or larger) jar. Individual
aliquots in storage from any "hit" composites can be
analyzed later to pinpoint contamination.
2.4 WASTE TYPES
The types of wastes encountered at a site greatly
influence the development of the site sampling plan.
The number of grab and composite samples, type of
screening/sampling equipment used, and analytical
methods all depend on the types of wastes present at
the site. Waste solids can vary from granular or
powdered materials to contaminated structural
surfaces or demolition debris. Waste liquids can
include solvents, acids, bases, process solutions, and
lubricants, among others. Waste sludges have
characteristics of both solids and liquids.
Each type of waste may be highly concentrated,
consisting of virtually pure industrial products, raw or
spent materials, chemicals, or process by-products.
Methods for sampling and analyzing vary by waste
type, and the sampling plan should specify appropriate
sample collection and analysis methods.
Waste samples are often complex mixtures and may
be difficult to analyze in the laboratory. Provide the
analytical laboratory with as much information as
possible to help minimize delays in analysis. The
laboratory will find the following information helpful
in expediting the analysis of waste samples:
Whether the sample is pure waste or an
environmental sample (e.g., oil as opposed to oily
water).
Viscosity, particle size, or an accurate description
of the waste characteristics.
Qualitative estimate of concentration (i.e., low,
medium, high).
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Presence of extreme pH levels (i.e., less than 2 or
greater than 12); some analytical methods will
not yield successful results on such samples; it
may be necessary to consult with a chemist to
change the method.
Presence of chlorinated dioxins, even if the
samples are being analyzed for another parameter
(e.g., metals). The Occupational Safety and
Health Administration (OSHA) specifies special
handling facilities for samples contaminated with
dioxin; many laboratories are not set up to handle
these samples.
Presence of high concentrations of organic
substances, particularly aromatics, in samples to
be analyzed for metals (some methods for metals
analysis are not compatible with high
concentrations of organic materials).
Inform the laboratory in advance about important
sample constituents of interest and QA/QC criteria.
Waste samples typically must be diluted before
analysis, which may prevent detection of these
constituents. Also consult with the laboratory on how
to prepare subaliquots of non-typical samples.
2.5 WASTE CHARACTERISTICS
Waste characteristics, including homogeneity,
physical state, chemical stability, particle size (solids),
and viscosity (liquids) are other factors that influence
the number and types of samples collected.
2.5.1 Homogeneity
Wastes may be homogeneous or heterogeneous. The
solubility, specific gravity, and mechanical mixing
ability of the waste can affect its degree of
homogeneity. A single grab sample per waste stream
may be appropriate for a homogeneous material;
however, heterogeneous and unclassified wastes often
require more extensive sampling and analysis to
ensure that the various phases and concentrations of
the waste are represented in the samples. The
sampling strategy should reflect the homogeneity,
random heterogeneity, or stratification of the waste
over space or time.
2.5.2 Physical State
The physical state of waste (i.e., solid, liquid, gas, or
multiphasic) will influence the selection of sampling
devices and many other aspects of the sampling effort.
Variances in each physical state can also affect
sampling. For example, free-flowing liquid would
require a different sampling approach than a viscous
liquid.
Sample containers with wide mouths are best for solid
samples, sludges, and liquids with substantial amounts
of suspended matter. Bottles with air-tight closures
are needed for gas samples or gases adsorbed onto
solids or dissolved in liquids.
The sampling strategy will vary if the physical state of
the waste is subject to stratification (for example,
liquid wastes with differing densities or viscosities, or
those with suspended solids), homogenization, or
random heterogeneity.
2.5.3 Chemical Stability
Waste materials can differ considerably in their
inherent chemical stability. Exposure to the elements
(e.g., sunlight, air, rain) and leaching may cause
chemical degradation or reaction, thereby creating
new compounds. Heterogenous materials may
undergo physical separation, resulting in pockets or
layers of different compounds. Sampling methods and
shipping practices will vary according to the toxicity,
ignitability, corrosivity, and reactivity of the waste.
2.5.4 Particle Size (solids)
Waste solids are often made up of materials with
different particle sizes. This variation can influence
analytical results by introducing either a negative or
positive bias. For example, if large pieces of waste
material (e.g., slag) are not collected and included
with a sample, a negative bias of contaminants may
result (analytical results may be lower than what is
actually representative). Small particle size can also
bias a sample. Some pollutants adsorb more readily
onto small particles, so a small-fraction sample may
result in a positive bias (analytical results may be
higher than what is representative). If it is necessary
to sample material that has unusual particle size
characteristics, identify an approximate size
distribution and consult the laboratory in advance to
determine a method for representative analysis of the
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irregular materials. Sieving of waste is not usually
recommended. If grinding or pulverizing large pieces
is desired, make special arrangements with the
laboratory.
2.5.5 Viscosity (liquids)
Viscosity is the internal friction of a fluid that
produces a resistance to flow. The viscosity of waste
liquids often greatly affects the effort required for
sample collection and may indirectly determine the
volume of sample required. Because viscosity can
affect the representativeness of the sample, and can
itself be a physical limitation for sampling, a sampling
technique suited to the viscosity of the material must
be selected. Very viscous materials (greater than
100,000 centipoise (cps)) must be scooped, while low
viscosity materials may be aspirated, encapsulated, or
poured. To collect a representative sample for
viscosity testing, it is important to limit handling and
contact time. The sample must be allowed to return to
equilibrium before measurement. Without a
viscometer, viscosity may be roughly determined by
comparison to water (low viscosity), syrup (medium
viscosity), and mayonnaise or taffy (high viscosity), as
well as to other materials of known viscosity.
Several sampling devices have been designed to
sample waste liquids within a specific viscosity range.
Weighted bottle samplers, PACS grab samplers, and
composite liquid waste samplers (COLIWASAs) are
suited for sampling less viscous liquids and become
difficult to use in very viscous liquids. The glass thief
and bacon bomb sampler are suitable for sampling
moderately to highly viscous materials. See Section
3.2 for a discussion of sampling equipment.
2.6 WASTE SOURCES
There are a variety of potential waste sources
commonly found at waste sites. The type of waste
source affects many aspects of the sampling design,
such as sampling approach (e.g., judgmental or
random), sampling equipment, and types/numbers of
samples (including QA/QC samples). The type of
source will also affect many logistical considerations,
such as cost, level of effort, and duration of a response
action. This section introduces the three categories of
waste sources: containerized waste, uncontainerized
waste, and surfaces and debris.
2.6.1 Containerized Waste
Containerized waste consists of solids, liquids, or
sludges that are found in drums, bulk storage tanks,
transformers, and lab packs. Evaluate container label
information before making sampling decisions. It
may be possible to identify numerous containers of
similar material. Wherever possible, use screening
techniques to substantiate label information.
Screening results should be confirmed with laboratory
test results prior to making any treatment or disposal
decisions (affirming that screening was effective).
Specialized equipment (e.g., forklift, grapple, manlift)
may be needed to access drums and tanks safely.
The sampling objective determines which and how
many containers need to be sampled. For example, if
the objective is to establish threat, it may be most
important to sample a few containers having visible
leaks or spills. If the objective is to estimate the
disposal cost, it may be appropriate to sample each of
the largest volume containers to identify the
predominant waste streams.
Drums can be of different volumes (typically from 30
to 90 gallons), varied construction (e.g., top bung, side
bung, removable top, lined), and be made of a variety
of materials (e.g., steel, polyethylene, fiber,
combinations). Drums located at a waste site often
vary in condition, sometimes showing deterioration,
bulging, and/or damage. These physical criteria can
be useful in making assumptions about a drum's
contents. For example, strong acids, caustics, or other
corrosives are typically stored in 30- to 55-gallon
polyethylene or polyethylene-lined steel drums with
top bung holes. While this is not a fool-proof method
of determining drum contents, it gives the investigator
an indication prior to sampling of the general types of
materials to be encountered.
Bulk storage tanks include tank cars/trucks, vats,
storage vessels, and transformers. They range in size
from less than 100 gallons to millions of gallons.
Like drums, bulk storage tanks are constructed of
many different materials and are designed in many
configurations.
Lab packs consist of small, individually-labelled
containers of laboratory waste or unused reagents.
The chemical containers are usually not more than
five gallons each, and are often packaged or
transported together in a larger Department of
10
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Transportation (DOT) shippable container (these are
typically 30- to 55-gallon drums). Be sure to screen
lab packs for radioactivity, since radioactive
substances (alpha, beta, and gamma emitters) are
commonly found in lab packs.
Another type of waste that can be found on site is
biological waste, also known as "red bag waste."
Note that contaminated biological waste (dressings,
syringes, etc.) may not always be found in the
required red bag. It should be handled only by
personnel specifically trained and authorized to deal
with biological waste. If "red bag waste" is
encountered at a site, notify the AT SDR, or local
health authorities.
2.6.2 Uncontainerized Waste
Uncontainerized waste consists of solids, liquids, and
sludges that are found in waste piles and surface
impoundments.
Waste piles may be composed of solid wastes such as
tank bottom solids, contaminated soil, ash, solidified
sludges, or a mixture of liquid and solid chemical
wastes. The shape and size of waste piles can vary
greatly, depending on the generating process or
facility. The sampling plan should take into account
the chemical and physical characteristics of the waste
pile. For example, contaminants can leach out of the
surface layers of a waste pile, resulting in deceptively
low or nonrepresentative concentrations at the top.
The sampling plan should account for leaching by
taking composite samples from various horizons
within the pile to determine an "average"
concentration.
Surface impoundments include lined and unlined
lagoons, ponds, and trenches that contain
predominantly liquids and sludges from site processes
or surface runoff. The liquids may be homogeneous
or stratified, depending on the chemical and physical
properties of the wastes. Reactions may occur within
the impoundment to alter or degrade the original
chemicals. Do not compromise any existing liners
when sampling bottom sludges.
2.6.3 Surfaces and Debris
Surfaces and debris require specialized sampling
techniques. During a response action, it may be
necessary to sample object and structural surfaces for
contamination to determine the need for dismantling
and eventual disposal. Virtually any surface on the
site may have to be sampled, including walls and
floors of buildings, process machinery, tanks, vats, air
ducts, vehicles, and furniture. There are three
methods for sampling surfaces: wipe sampling, chip
sampling, and dust sampling. Each method is
described further in Section 4.3.6.
Debris can be highly variable and includes demolition
rubbish, construction and destruction materials, paint
cans, empty 55-gallon drums, battery-casings,
shredded automobiles, and other miscellaneous
matrices such as process waste, tannery waste, and
slag. Debris may be composed of plastic, metal,
rubber, paper, concrete, wood, glass, masonry, and
municipal waste. It can include contaminated waste
sampling articles such as protective disposable
clothing (e.g., Tyvek suits), sample collection jars,
and disposable sampling equipment (e.g., plastic
scoops).
2.7 QUALITY ASSURANCE
CONSIDERATIONS
Quality assurance components are defined as follows:
Precision measurement of variability in the data
collection process
Accuracy (bias) measurement of bias in the
analytical process; the term "bias" throughout this
document refers to the QA/QC accuracy
measurement
Completeness percentage of sampling
measurements which are judged to be valid
Representativeness degree to which sample data
accurately and precisely represent the
characteristics and concentrations of the waste
contaminants
Comparability evaluation of the similarity of
conditions (e.g., sample depth, sample
homogeneity) under which separate sets of data are
produced
To ensure that the analytical samples are
representative of site conditions, quality assurance
measures must be associated with each sampling and
11
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analysis event. The sampling plan must specify these
measures. QA measures include, but are not limited
to: laboratory SOPs, sample bottle preparation,
equipment decontamination, field blanks, replicate
samples, performance evaluation samples, sample
preservation and handling, and chain-of-custody
requirements (see Chapter 5, Quality
Assurance/Quality Control).
2.8 DATA QUALITY OBJECTIVES
Data quality objectives (DQOs) state the level of
uncertainty that is acceptable for data collection
activities and define the certainty of the data necessary
to make decisions. When establishing DQOs for a
particular project, consider:
Decision(s) to be made or question(s) to be
answered
Why analytical data are needed and how the
results will be used
Time and resource constraints on data collection
Descriptions of the analytical data to be collected
Applicable model or data interpretation method
used to arrive at a conclusion
Detection limits for analytes of concern
Sampling and analytical error
2.9 FIELD ANALYTICAL
SCREENING AND
GEOPHYSICAL TECHNIQUES
There are two types of analytical data that can be
generated during a response action: field analytical
screening data and laboratory analytical data. Field
analytical screening instruments and techniques
provide real-time or direct (or colorimetric) readings.
They include: flame ionization detectors (FIDs),
photoionization detectors (PIDs), colorimetric tubes,
portable X-ray fluorescence (XRF) units, portable gas
chromatography (GC) units, immunoassay tests, and
hazard categorization kits. These screening methods
can assist with the selection of sample locations or
samples to be sent for laboratory analysis by
narrowing the possible groups or classes of chemicals.
They are effective and economical for gathering large
amounts of site data. After an area or group of
containers has been characterized using field
screening techniques, a subset of samples can be sent
for laboratory analysis to substantiate the screening
results. Field analytical screening with laboratory
confirmation usually generates more analytical data
under a limited sampling budget than will sampling
with off-site laboratory analysis alone. Whenever
possible, use field analytical screening methods which
provide detection limits below applicable action
levels. If these methods are not available, field
analytical screening can still be useful for waste
sampling by detecting grossly contaminated areas as
well as for on-site health and safety determination.
Field analytical screening techniques to support waste
sampling are discussed in more detail in Chapter 3.
Geophysical techniques may be utilized during a
response action to locate potential buried drums or
tanks, buried waste, and disturbed areas. Geophysical
techniques include ground penetrating radar (GPR),
magnetometry, electromagnetic conductivity (EM),
and resistivity surveys. Refer to U.S. EPA
Representative Sampling Guidance, Volume 1 Soil,
OSWER Directive 9360.4-10, for a discussion of soil
geophysical techniques that are also applicable for
waste sampling.
2.10 ANALYTICAL PARAMETERS
AND METHODS
Designing a representative waste sampling plan
includes selecting analytical parameters and methods.
Use data collected during the historical data review
(e.g., past site processes, materials stored on site) to
select appropriate analytical parameters and methods.
If the historical data review reveals little information
about the types of waste on site, select analytical
parameters by initially characterizing the waste. Use
applicable field screening methods and limited
laboratory analysis to rule out the presence of high
concentrations of certain contaminants, and to narrow
the list of analytical parameters. Methods often used
for characterization of waste include GC/MS (gas
chromatography/mass spectroscopy) screening for
tentatively identified compounds (TICs) in the volatile
and semivolatile organic fractions, infrared
spectroscopy (IR) for organic compounds, inductively
coupled plasma (ICP) for inorganic substances, and
product comparison. These methods are used to
determine chemical percentages in waste samples.
After characterization, future sampling and analysis
efforts can focus on substances identified above the
action level.
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2.11 REPRESENTATIVE SAMPLING
APPROACHES
Representative sampling approaches appropriate for
waste sampling include judgmental, random,
systematic grid, systematic random, and transect
sampling. A representative sampling plan may use
one or a combination of these approaches.
2.11.1 Judgmental Sampling
Judgmental sampling is the biased selection of
sampling locations at a site, based on historical
information, visual inspection, sampling objectives,
and professional judgment. In waste sampling, three
distinct situations prevail: 1) selecting locations
within a large waste stream such as a waste pile or a
stratum in an impoundment; 2) selecting a subset of
containerized wastes when all containers cannot be
sampled; and 3) sampling both containerized and non-
containerized wastes in order to identify worst-case
conditions and establish threat. If determining threat,
the presence of certain site conditions such as leaking
drums, spill areas, and large volume containers will
indicate appropriate sampling locations if the source
is known to be hazardous. Select drums to sample by
existing labelling/markings or by container type, but
not by random selection. When establishing threat,
screen drums first to select a subset of drums
containing hazardous materials or waste to be sent for
analysis. This will avoid sampling drums of non-
hazardous materials, which is not cost-effective.
Judgmental sampling includes no randomization in the
sampling strategy, precluding statistical interpretation
of the sampling results.
2.11.2 Random Sampling
Random sampling is the arbitrary collection of
samples having like contaminants within defined
boundaries of the area of concern. Choose random
sampling locations using a random selection
procedure (e.g., a random number table). (Refer to
Ford and Turina, July, 1984, for an example of a
random number table.) The arbitrary selection of
sampling points ensures that each sampling point is
selected independently from all other points, so that
all locations within the area of concern have an equal
chance of being sampled. Randomization is necessary
in order to make probability or confidence statements
about the sampling results. The key to interpreting
these statements is the assumption that the site or
waste stream is homogeneous with respect to the
parameters being monitored. The higher the degree of
heterogeneity, the less the random sampling approach
will adequately characterize true conditions. The use
of random sampling on a subset of containers is not
appropriate if different waste streams or
concentrations might be present. Random sampling of
waste piles and impoundments is often appropriate
because of their large areal extent and relative
homogeneity. Use random sampling to confirm the
attainment of treatment levels of contaminated waste.
(Refer to U.S. EPA, Methods for Evaluating the
Attainment of Cleanup Standards, Volume 1 Soils
and Solid Media, EPA/230/02-89/042, pages 5-3 to 5-
5 for guidelines on selecting sample coordinates for
random sampling.) Figure 2 illustrates a random
sampling approach.
Figure 2: Random Sampling
200-
I 1 1 1 1 1 1 1
50 100 150 200 250 300 350 400
KEY
X SELECTED SAMPLE LOCATION
After U.S. EPA, February 1989
13
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2.11.3 Systematic Grid Sampling
Systematic grid sampling involves subdividing the
area of concern by using a square or triangular grid
and collecting samples from the nodes (intersections
of the grid lines). Select the origin and direction for
placement of the grid using an initial random point.
From that point, construct a coordinate axis and grid
over the source. Generally, the more samples
collected (and the smaller the grid spacing), the more
reproducible and representative the results. Shorter
distances between sampling locations also improve
representativeness.
Systematic grid sampling can be used to characterize
a waste pile, impoundments, or loose tank bottom
solids. Systematic grid sampling is not applicable to
sampling individual small containers or drums. (Refer
to U.S. EPA, Methods for Evaluating the Attainment
of Cleanup Standards, Volume 1 Soils and Solid
Media, pages 5-5 to 5-12 for guidelines on selecting
sample coordinates for systematic grid sampling.)
Figure 3 illustrates a systematic grid sampling
approach.
Figure 3: Systematic Grid Sampling
200-
150--
100--
50-
-\ h
-\ 1 h
0 50 100 150 200 250 300 350 400
FEET
KEY
X SELECTED SAMPLE LOCATION
After U.S. EPA, February 1989
2.11.4 Systematic Random
Sampling
Systematic random sampling is a useful and flexible
design for estimating the average pollutant
concentration within grid cells. Subdivide the area of
concern using a square or triangular grid (as
mentioned above) then collect samples from within
each cell using random selection procedures.
Systematic random sampling allows for the isolation
of cells that may require additional sampling and
analysis. Like systematic grid sampling, systematic
random sampling can be used to characterize a waste
pile, loose tank bottom solids, or impoundments, but
not small containers or drums. Figure 4 illustrates a
systematic random sampling approach.
2.11.5 Transect Sampling
Transect sampling involves establishing one or more
transect lines across a surface. Collect samples at
regular intervals along the transect lines at the surface
and/or at one or more given depths. The length of the
transect line and the number of samples to be
collected determine the spacing between sampling
points along the transect. Multiple transect lines may
be parallel or non-parallel to one another. If the lines
are parallel, the sampling objective is similar to
systematic grid sampling. The primary benefit of
transect sampling versus systematic grid sampling is
the ease of establishing and relocating individual
transect lines.
Transect sampling is applicable to waste piles or
impoundments. Figure 5 illustrates a transect
sampling approach.
14
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Figure 4: Systematic Random Sampling
200-
150-
100-
50-
(
/IT
X
X *
^-
X
X
" ซ
X
X
X
X
X
X
X
X
X
X
X
X
*;
XV
X
*
jy
0 50 100 150 200 250 300 350 400
FEET
KEY
X SELECTED SAMPLE LOCATION
After US. EPA, February 1989
Figure 5: Transect Sampling
Hi
LU
200
150
100
50
-I I h-
50 100 150
I \-
200 250
FEET
+
-t
300 350 400
KEY
SELECTED SAMPLE LOCATION
After U.S. EPA, February 1989
2.12 SAMPLING LOCATIONS
AND NUMBER
The locations and number of samples to be collected
must be carefully selected to obtain samples that are
truly representative of the material being sampled, as
well as of the general site area. The sampling
objectives, waste type, container/source type,
sampling approach, and other factors determine where
and how many samples are collected. For example, a
judgmental sampling approach can establish threat or
identify the presence of wastes with a few carefully
selected samples. A larger number of samples are
needed to characterize wastes, and sampling locations
should be selected using random, systematic grid, and
systematic random sampling techniques. Field
screening techniques are valuable for selecting
15
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sampling locations. In situations where there is a very
large waste area or numerous containers of potentially
different wastes, field screening techniques may
identify similar waste streams. These wastes can be
segregated into general chemical classes (e.g., strong
acids, halogenated solvents) and then samples can be
collected for confirmation by laboratory analysis.
Sampling locations which pose a severe chemical or
physical hazard to sampling teams (e.g., cylinders of
hydrofluoric acid, hydrogen cyanide, or nerve agents)
should be avoided or sampled remotely. Sampling
cylinders requires specially trained and authorized
personnel.
2.13 EXAMPLE SITE
2.13.1 Background
ABC Plating, a multi-purpose specialty plating facility
in northern Pennsylvania operating from 1947 to 1982,
stored and treated its plating wastes by placing them
in a series of unlined and unpermitted impoundments.
State RCRA personnel cited the owner/operator for
the operation of an unpermitted treatment system and
ordered the owner to submit a remediation plan for
state approval. Before the state could follow up on the
order, the impoundments were partially backfilled
with the wastes in place. The facility was later
destroyed by a fire of suspicious origin. The owner
abandoned the facility and could not be located by
enforcement authorities. The state contacted U.S.
EPA for an assessment of the site for a possible
federally funded response action.
U.S. EPA initiated a removal assessment with the
following primary sampling objectives:
To establish the identities and volumes of
hazardous materials present on the site to
determine the potential threat to the surrounding
population and the environment.
To develop site stabilization strategies.
After federal funds were obtained and the site was
stabilized, EPA addressed two additional objectives:
To identify treatment and disposal options for the
wastes on site.
To verify that established clean-up levels are met.
2.13.2 Site Entry
Within four hours of the initial request for assistance
from the state, an EPA On-Scene Coordinator (OSC)
and other response personnel mobilized to the site
with equipment to perform multi-media sampling.
The next day, the OSC met with the township
manager, representatives from the county health
department and the Pennsylvania Department of
Environmental Resources (PA DER), and the
township Fire Chief. The OSC reviewed PA DER
enforcement reports and aerial photographs which
indicated the presence and locations of chromium,
copper, and zinc plating process areas. The OSC
interviewed local residents and performed a walk-
through, donning Level B personal protective
equipment (PPE), to survey the general site
conditions. A site sketch was generated (Figure 6),
indicating the locations and container types of the
wastes. A total of nineteen 30- and 55-gallon fiber
and metal drums, fifteen 250- to 500- gallon plating
vats, two 10- to 15- cubic yard waste piles, a feeder
trench leading to two 80 feet x 20 feet x 7 feet
partially filled impoundments, and a transformer were
located and noted in the site sketch. Some rooms of
the building could not be entered because of unsafe
structural conditions caused by the fire.
The OSC and PA DER reviewed all available
information to formulate a sampling plan for the
drums, vats, impoundments, and waste piles. The
entry team used a judgmental sampling approach
during the initial assessment, first collecting samples
from containerized wastes for screening and possible
analysis (suspecting that the containerized
concentrated material posed the greatest potential
hazard).
16
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Figure 6: ABC Plating Site Sketch
Die
D18 Dig
VI
c55^
01
^
UlTi
plating vat
waste pile
drum
door
transformer
Note: map Is not to scale
2.13.3 Site Inventory
During this phase of the response, a field entry team
in Level B personal protective equipment (PPE)
inventoried drums, plating vats, waste piles,
impoundments, and a transformer found at the site.
Drums
The entry team numbered each drum and noted drum
type, size, condition, and label information on a drum
inspection log (Figure 7). The chemical properties of
constituents listed on labelled drums were researched.
Typical hazardous materials used at plating facilities
were determined from the references available; these
substances include strong acids and bases, heavy
metal solutions and solids, and cyanide-bearing
compounds.
Vats
The plating vats were inspected, numbered, and noted
on the site sketch. An estimate of the volume was
documented for each of the vats. All vats were
covered with non-reactive polyethylene sheeting to
prevent rain water from collecting in them and
increasing the waste stream volume.
Waste Piles
The waste piles were inspected and noted on the site
sketch. Transects were established along the longest
horizontal axis of each pile. The transects were also
noted on the site sketch. The samples will be
collected and screening will be conducted along each
transect.
Impoundments
The OSC determined that the contents of the
impoundments posed a potential direct contact hazard
to the surrounding population. In preparation for
sampling, a transect was established from the entry
point of the feeder trench across each impoundment.
During site operation, wastes flowed from the feeder
trench into the impoundments. Suspended solids were
suspected to be present in a gradient decreasing with
distance from the feeder trench.
17
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Transformer
The OSC was concerned that the single transformer
outside the plating building could contain PCB
dielectric fluid. Inspection of the transformer
determined that it was disconnected by first
responders during the facility fire. The maximum
transformer volume, the type of oil used, the date of
manufacture, and the manufacturer's name were
indicated on the metal plate on the side of the unit,
and this information was noted. The unit was not
leaking, so it was numbered and noted on the site
sketch for future screening or sampling.
Information obtained from the site inventory and data
review was used to create a site-specific conceptual
model. Sources (e.g., vats, drums), pathways (e.g.,
vapors from the impoundments, soil under leaking
drums), and potential receptors (e.g., local residents)
were detailed to assist the selection of sampling
approaches, objectives, and locations.
2.13.4 Selecting Analytical
Parameters
Analytical parameters were selected based on research
of plating chemistry and the initial site screening.
Plating facilities generally use either an acid bath or
basic cyanide bath to achieve the desired coating on
their metal products. Based on the researched
information and the measured pH of the liquid wastes
on site, the following compounds were suspected to be
present:
Sodium and zinc cyanide salts and sodium
hydroxide (highly basic, grey to green color) from
zinc plating practices
Chromic acid and sulfuric acid/sodium sulfate
(acidic, yellow or dulled color) from chromium
plating practices
Copper sulfate and sulfuric acid (acidic, blue/green
color) from copper plating practices.
During the assessment, liquid vat samples underwent
field screening to assist in the selection of analytical
parameters. Samples from all highly basic solutions
were shipped to a laboratory for analysis of metals and
cyanide. Acidic samples were sent for analysis of
metals only. The composition of some of the
drummed materials was initially unknown. In
addition to the plating chemicals listed above, other
possible drum contents included various cleaners, oils,
fuels, and solvents. Many of the drums still had labels
identifying their contents, and field screening was
used to confirm content composition. Acids and bases
were easily identified with pH paper, which was by
far the most useful and inexpensive screening tool.
The waste piles were thought to include plating vat
sludge waste. Samples collected from the piles were
sent for laboratory metals and cyanide analyses.
Initial samples from impoundment liquids and solids
(large-volume unsecured waste streams) were sent for
full target analyte list (TAL), hexavalent chromium,
pH, and total and amenable cyanide analyses. These
analyses were conducted to fully characterize the
liquid impoundment wastes for evaluation of the
various on-site water treatment system needs. This
information was later used to select optimum pH
conditions and flocculent type for maximum settling
efficiency. A local industrial wastewater treatment
facility agreed to accept the liquid wastes if the heavy
metal and cyanide levels were within their permit
parameters. In addition to evaluating off-site
treatment and disposal options, the impoundment
bottom samples were characterized using target
compound list (TCL), hexavalent chromium, total and
amenable cyanide, pH, and total alkalinity analyses to
allow evaluation of possible on-site stabilization,
solidification and treatment techniques.
18
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Figure 7: Example of a Drum Inspection Log
DRUM INSPECTION LOG
Site:
Location:
Drum Number: Date:
Project Code Number: Time:
Type of Contents: SOLID LIQUID SLUDGE
Color PID
LAB PACK
pH CGI
FID
Amount of Contents: Full 3/4 1/2 1/4
Drum Size: 5 5 -gallon 41 -gallon 30-gallon
Drum Markings:
Less than 1"
5 -gallon
Hazard Class Label:
Drum Type: 17H 17E 37M Fiber Overpack
Drum Construction: Metal Poly Fiber Polylined
Drum Condition: Deteriorated Leaking Dented
Sample Method: Pipette Trowel Other
Sample Number Custody Sheet Number
Other
Other
OK/DOT
Comments: LAYER DESCRIPTION
Observations by:
19
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3.0 FIELD ANALYTICAL SCREENING AND SAMPLING EQUIPMENT
3.1 INTRODUCTION
Field analytical screening techniques and equipment
may provide valuable information for developing
sampling strategies. Field analytical screening can
determine chemical classes of wastes and in some
cases can identify particular substances of concern.
Real-time or direct-reading capabilities narrow the
possible groups or classes of substances which aids in
selecting the appropriate laboratory analytical method.
These screening techniques are useful and economical
when gathering large amounts of site data. Some of
the commonly used screening methods for waste
analysis are presented in this chapter in the general
order that they would initially be used at a waste site,
although site-specific conditions may mandate a
different sequence. This chapter focuses on site-
screening methods, but the instruments described
below have specific health and safely applications as
well. Refer to the Compendium of ERT Waste
Sampling Procedures, OSWER Directive 9360.4-07,
for specific information about most of the following
techniques or equipment. Refer to Standard Operating
Safety Guides for each instrument, and the
Occupational Safety and Health Guidance Manual
for Hazardous Waste Site Activities (NIOSH Pub.
85-115) for site entry information.
3.1.1 Combustible Gas Indicator
The combustible gas indicator (CGI) measures the
concentration of a flammable vapor or gas in the air,
registering the results as a percentage of the lower
explosive limit (LEL) of the calibration gas. The CGI
is often combined with an oxygen meter; some
contemporary models also have built-in compound-
specific detectors (e.g., hydrogen sulfide, sulfur
dioxide, carbon monoxide, and hydrogen cyanide).
CGIs are particularly useful for entry into unknown
and/or confined space atmospheres.
There are several factors that must be considered
when using a CGI for waste site work. The accuracy
of the reading is temperature dependent; the CGI must
be calibrated at ambient temperatures. The sensitivity
of the CGI is also a function of the physical and
chemical properties of the calibration gas versus those
of the unknown atmosphere. Oxygen concentrations
that are less than or greater than normal may cause
erroneous readings. Leaded gasoline vapors,
halogens, silicates, and sulfur compounds can
decrease sensitivity. As a sample screening tool, the
CGI is of limited value because it yields non-
qualitative results for flammable vapors.
3.1.2 Radiation Screening
Instruments
Screening for ionizing radiation is mandatory for all
Superfund assessments, primarily for health and safety
reasons. Since gamma rays and X-rays have high
penetration capabilities even at extended distances,
radiation screening instruments are generally used
during the initial site entry. As containerized wastes
are opened, alpha and beta radiation which was not
detected during the initial walk-through screening may
be encountered.
Most of the commonly used radiation screening
instruments have gamma or beta/gamma detecting
probes. Pure alpha detectors are not commonly used
on site because the probes are too fragile and because
pure alpha emitters are rare. However, an
alpha/beta/gamma probe is suggested for screening
wastes in lab packs, research facilities, laboratories,
and on military installations where radioactive waste
may be present (e.g., Department of Defense (DOD)
and Department of Energy (DOE) installations).
3.1.3 Flame lonization Detector
The flame ionization detector (FID) detects and
measures the level of total organic compounds
(including methane) in the ambient air or in a
container headspace. The FID is used to evaluate
existing conditions, identify potential sample locations
and extent of contamination, and support health and
safety decisions. The FID uses the principle of
hydrogen flame ionization for detection and
measurement. It is especially effective as an
ethane/methane detector when used with an activated
charcoal filter because most organic vapors are
absorbed as the sample passes through the filter,
leaving only ethane and methane to be measured.
20
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The FID operates in one of two modes: the survey
mode, or the gas chromatography (GC) mode. In the
survey mode, the FID provides an approximate total
concentration of all detectable organic vapors and
gases measured relative to the calibration gas (usually
methane). The GC mode identifies and measures
specific components, some with detection limits as
low as a few parts per million (ppm), using known
standards run concurrently in the field. Since the GC
mode requires standards to identify classes of
compounds, before sampling it is necessary to have an
idea of which compounds might be present on site.
Advantages of the FID are that it is portable,
relatively rugged, and provides real-time results.
The FID does not respond to inorganic substances. It
has positive or negative response factors for each
compound depending on the selected calibration gas
standard. The FID does not recognize and may be
damaged by acids; use pH paper to screen acids.
Ambient air temperatures less than 40 degrees
Fahrenheit will cause slower responses; relative
humidity of greater than 95 percent can cause
inaccurate and unstable responses. Low ambient
oxygen levels can cause the flame to go out; use a
CGI/oxygen meter in conjunction with an FID in
confined space applications. Interpretation of
readings (especially in the GC mode) requires training
and experience with the instrument.
3.1.4 Photoionization Detector
Another portable air monitoring instrument frequently
used for field screening is the photoionization detector
(PID). Like the FID, the PID provides data for real-
time total organic vapor measurements evaluating
existing conditions, identifying potential sample
locations and extent of contamination, and supporting
health and safety decisions. The PID works on the
principle of photoionization. Unlike the FID, the PID
can be used to detect gross organic, and some
inorganic vapors depending on the substance's
ionization potential (IP) and the selected probe energy.
It is portable and relatively easy to operate and
maintain in the field.
The PID detects total concentrations and is not
generally used to quantify specific substances. PIDs
cannot detect methane; however, methane is an
ultraviolet (UV) light absorber, and false negative
instrument readings may register in methane-rich
environments. The PID cannot detect substances with
IPs greater than that of the UV light source. Readings
can be affected by high wind speeds, humidity,
condensation, dust, power lines, and portable radios.
Dust particles and water droplets (humidity) in the
sample may collect on the light source and absorb or
deflect UV energy, causing erratic responses in PIDs
not equipped with dust and moisture filters.
3.1.5 Colorimetric Tubes
Colorimetric indicator tubes (e.g., Drager, Sensidyne,
MSA) provide real-time results in environments
where a specific gas or vapor is suspected to be
present. In waste sampling, they are useful for
situations such as screening drums, where drum labels
provide limited information on the contents of only
some of the drums.
Colorimetric tubes consist of a glass tube filled with
silica gel or a similar material impregnated with an
indicator reagent which changes color in the presence
of specific contaminants. The tube is attached to an
intrinsically safe piston-syringe or bellows-type pump
which slowly pulls a measured volume of air through
the tube. The contaminant then reacts with the
indicator chemical within the tube producing a color
change proportional to the concentration of the
chemical.
Although the indicator tubes are usually chemical or
class specific, interferences can occur. Common
interferences are noted in the directions for the
specific tube. The tubes have a limited shelf life, and
cannot be reused. Results can be misinterpreted due
to cross-sensitivity, and there exists a potential for
error in reading the end point of color change. Errors
result if the limit of the tube has been exceeded (in
very concentrated environments). High humidity may
reduce tube sensitivity.
3.1.6 Hazard Categorization
Hazard categorization (haz-catting) is performed as an
initial screen for hazardous substances to provide
identification of the classes/types of substances
present in individual waste streams. Haz-catting tests
for general chemical characteristics or the presence of
specific ions to determine chemical class; it is not
compound-specific. The information from haz-catting
is useful for determining compatibility of unknown
wastes.
21
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Various indicators and wet chemistry tests
characterize the wastes according to their
chemical/physical properties (e.g., solubility,
combustibility), and indicate the presence of sulfides,
oxidizers, and cyanide. The haz-catting procedure
requires numerous chemical reagents and
interpretation of results. Common haz-cat tests
include the char test for differentiating organic from
inorganic substances; chlorine hot wire test to detect
chlorine in organic solvents; combustibility test;
cyanide test for cyanide salts; flame test for
identifying cations and some anions; iodine crystal
test for solvent classification; oxidizer test; sulfide
test; water solubility test; and/)// test.
3.1.7 Immunoassay Tests
Immunoassay tests can be used on site to screen for
certain organic compounds such as pentachlorophenol
(PCP), PCBs, and pesticides. Immunoassay tests are
used for locating and mapping the extent of
contamination, and for screening samples in the field
prior to laboratory analysis.
Immunoassay tests utilize semi-quantitative,
colorimetric methods. Some of the commonly used
tests utilize tubes coated with a chemical that
specifically binds to the contaminant. These types of
tests utilize highly selective antibodies and sensitive
enzyme reactions to yield qualitative, semi-
quantitative, and quantitative results for a specific
compound or for a closely related series of compounds
(e.g., PCP, PCBs, and 2,4,D-pesticides). Antibodies
can be either coated on the test tube, or attached to
microparticulates or reaction well/ plates, depending
on the brand. Other types of immunoassay tests
utilize enzyme-linked, immunosorbent assays
(ELISAs) and magnetic particles to bind to the
contaminants.
The concentration range of a sample is determined by
comparing the color change of the sample with that of
duplicate standards of known concentrations. The
color intensity in each tube decreases as the
contaminant concentration increases. Photometers are
available to "read" and digitally display, print, and
store the color difference between the prepared sample
and the standards. Since the results are compared to
standards, the accuracy achievable is a contaminant
range (e.g., greater than 100 ppm but less than
1,000 ppm). Laboratory confirmation is required when
using these tests in the semi-quantitative and
qualitative modes. Performance evaluation spikes
determine the efficiency of the test. Some training is
needed to effectively run and interpret immunoassay
tests.
3.1.8 X-Ray Fluorescence
Field analytical screening using X-ray fluorescence
(XRF) is a cost-effective and time-saving method to
detect and classify lead and other heavy metals in
wastes. XRF screening provides immediate semi-
quantitative results. The principle behind XRF is the
detection and measurement of the X-rays released
from an atom when it is ionized. The measure of
energy released identifies the atom present.
Results of XRF analysis help determine the presence
of metals and are often used to assess the extent of
soil contamination at a site. For waste sampling, the
XRF can be used for screening waste piles and for
assessing metals in certain liquids such as paint. XRF
use requires a trained operator and may require
numerous site-specific calibration samples.
3.1.9 Gas Chromatograph
Although many FIDs are equipped with a GC mode,
an independent, portable GC can also be used on site
to provide a chromatographic profile of the occurrence
and intensity of unknown volatile organic compounds
(VOCs). The GC is useful as a screening tool to
determine "hot spots," potential interferences, and
semi-quantitation of VOCs and semi-volatile organic
compounds (semi-VOCs).
Compounds with high response factors, such as
benzene and toluene, produce large response peaks at
low concentrations, and can mask the presence of
compounds with lower response factors. However,
recent improvements in GCs, such as pre-concentrator
devices for lower concentrations, pre-column
detection with back-flush capability for rapid
analytical time, and the multi-detector (PID, FID, and
electron capture detector (BCD)), all enable better
detection of compounds. The GC is highly
temperature-sensitive. It requires set-up time, many
standards, and operation by trained personnel.
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3.2 SAMPLING EQUIPMENT
Representative waste sampling requires an
understanding of the capabilities of the sampling
equipment, since the use of inappropriate equipment
may result in biased samples. Select appropriate
sampling equipment based on the sample type and
matrix, physical location of the sample point, and
other site-specific conditions. Consideration must be
given to the compatibility of the waste with the design
and composition of the sampling device. Follow
SOPs for the proper use and decontamination of
sampling equipment. This section provides
descriptions of drum opening and sampling equipment
descriptions, and other information to assist in
selecting appropriate equipment. Refer to the
Compendium of ERT Waste Sampling Procedures,
OSWER Directive 9360.4-07, for expanded guidelines
on the use of the equipment discussed below.
3.2.1 Drum Openers
Closed drums need to be opened for sampling. Tools
suitable for opening drums include: universal bung
wrench, drum deheader, backhoe spike, hydraulic
drum opener, and pneumatic bung remover. Each of
these devices has specific applications based on the
drum type, composition, condition, location, and
suspected contents.
Follow ERT SOP #2009 (Drum Sampling) in the
Compendium of ERT Waste Sampling Procedures,
OSWER Directive 9360.4-07, for guidelines on
opening drums and the operating instructions for the
particular equipment used. Always use non-sparking
instruments to open drums and comply with proper
health and safety protocols. Note that the use of a
non-sparking tool does not completely eliminate the
possibility of a spark being produced. Drums should
be grounded to decrease the chance of static charges
and sparks. Stage drums by suspected compatibility
type prior to opening and sampling to decrease the
risk of chemical reaction between incompatible
substances.
3.2.2 Liquid Samplers
The following samplers are useful for collecting waste
liquids from various sources: composite liquid waste
sampler (COLIWASA), glass thief, bailer, and bacon
bomb. Each has specific applications for use
depending on the type and nature of the waste and the
type of source.
COLIWASA
The COLIWASA is a tool typically used for sampling
stratified liquids in drums and other similar
containers. It is a transparent or opaque glass, PVC,
or Teflon tube approximately 60 inches in length and
1 inch in diameter. A neoprene stopper at the bottom
of the tube can be opened and closed via a rod that
passes through the length of the sampler.
The COLIWASA is difficult to decontaminate in the
field but is versatile and simple to operate. Because
of the relatively high cost of the COLIWASA,
COLIWASA-type glass thieves have been developed
which utilize neoprene or ground glass stopper
mechanisms. Before conducting multiphased
sampling, make sure that the physical and chemical
properties of the container's contents and phases are
understood.
Glass Thief
Another commonly used drum sampling device, the
glass thief, is a hollow glass tube 40 to 48 inches in
length and commonly 10 mm to 19 mm in diameter.
The larger diameter tubes are used to collect more
viscous materials. The glass thief is simple to
operate, versatile, and disposable, eliminating the
need for decontamination.
Conduct the sampling carefully in order to avoid
sample spillage. Low viscosity liquids, thin-layered
phases, and partially filled containers may be difficult
to sample with a hollow glass thief. In those cases,
use the COLIWASA-type glass thief, whose stopper
mechanism prevents the sample from leaking out of
the thief as it is removed from the container.
Bailer
A bailer is used to sample waste liquids in vessels
(wells, tanks, or deep containers) where the liquid
surface is far below the sampling entry access (i.e.,
too far for a glass thief or COLIWASA). The bailer
consists of a hollow tube (constructed of relatively
inert materials such as stainless steel, glass, or Teflon)
with a bottom ball-check valve, usually suspended
from a wire or rope for sampling. Bailers are good for
23
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sampling VOCs because of the relatively low surface-
to-volume ratio which reduces off-gassing.
Most bailers cannot obtain discrete depth or phased
samples, so their use is primarily limited to
homogeneous liquids or shallow (length of bailer)
sampling. As with any sampling device, the
construction material should not interfere with the
wastes or the desired analytical parameters.
Bacon Bomb
The bacon bomb sampler is used to collect waste
liquid samples from various levels within storage
tanks or surface impoundments. Storage tank and
impoundment wastes are often stratified, and the
bacon bomb is useful when a discrete sample is
needed from any level in the tank or impoundment.
The bacon bomb consists of a cylindrical body with an
internal tapered plunger for sampling. A separate line
attached to the top of the plunger opens and closes the
bottom valve at the desired depth or stratum. A
removable top cover attaches the sample line and has
a locking mechanism to keep the plunger closed after
sampling. The bacon bomb is usually constructed of
chrome-plated brass and bronze or stainless steel. A
rubber O-ring acts as the plunger sealing surface.
Transfer of the sample to sample containers is
sometimes difficult and tends to aerate the sample,
resulting in loss of volatile constituents. The bacon
bomb sampler can be more difficult to decontaminate
than a bailer.
3.2.3 Sludge Samplers
The following devices are useful for sampling waste
sludges: Ponar/Ekman dredge, sludge judge, and
PACS grab sampler.
Ponar/Ekman Dredge
Ponar/Ekman dredges are clamshell-shaped scoops
that are used to extract waste sludge samples from the
bottom of impoundments, lakes, or other standing
water bodies. The Ponar dredge's jaws are latched
open and the unit is slowly lowered to the bottom of
the area being sampled. When tension is eased on the
lowering cable, the latch releases, and the lifting
action of the cable on the lever system closes the
dredge around a sample of sludge. The Ekman dredge
operates similarly but it closes by using a messenger
or depressing a button on the upper end of the handle.
The substrate depth to which both dredges can sample
usually does not exceed 4 to 6 inches, and they are not
capable of collecting an undisturbed sample. As a
result, material in the top inch of sludge cannot be
separated from material at lower depths. The
sampling action of the dredges causes agitation
currents which may temporarily re-suspend some
settled solids, especially the fine fraction.
Dredges are normally used from a boat or dock.
Because the dredges are heavy, a boom is frequently
used to ease the raising and lowering of them.
Dredges are not usually effective in sampling hard or
stony bottom material. Bottom vegetation will also
limit dredge effectiveness.
Sludge Judge
The sludge judge is a long narrow tube with a check
valve on the bottom, used primarily to obtain cores of
waste sludge, or waste liquids mixed with sludge,
from drums, tanks, or similar sources. Sludge judges
are useful for determining the physical state of a tank's
contents or its volume of settled sludge. The sludge
judge is constructed of PVC which can limit its use
because of potential interference with the
contaminants of concern. The device is difficult to
decontaminate and not recommended for use with
very thick sludges.
PACS Grab Sampler
The PACS grab sampler is used to collect sludge
samples at discrete depths from surface
impoundments such as ponds and lagoons and also
from certain types of containers. The PACS grab
sampler consists of a 1000-ml wide-necked bottle with
a control valve which screws on to the end of a 2-
meter long handle. Large openings in the bottle
facilitate sample collection. The control valve is
operated from the top of the handle once the sampler
is at the desired depth. Depth of sampling is limited
by the length of the pole handle. The device is not
useful in very viscous sludges, and it can be difficult
to decontaminate.
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3.2.4 Solids Samplers
The following devices are used to collect samples
from waste piles and other sources of solid waste:
scoop/trowel, bucket auger, sampling trier, waste pile
sampler, cork screw auger, and split-barrel sampler.
Scoop/Trowel
Scoops or trowels are useful for collecting solid or
sludge samples from waste piles. Collection is
usually limited to near-surface and depends on the
length of the scoop or trowel. These instruments are
available in a variety of materials, including stainless
steel and plastic. Stainless steel scoops and trowels
are appropriate for VOC sample collection but require
decontamination between sampling stations. Plastic
scoops and trowels are suitable for metal analyses and
are disposable, which eliminates the need to
decontaminate between sampling stations. Do not use
trowels with painted or chromium-plated surfaces,
because the paint or plating can chip off into the
sample.
Bucket Auger
Bucket augers are typically composed of stainless
steel and are used to collect solid or sludge samples
from waste piles or surface impoundments. The auger
is effective for subsurface sampling, but tends to
destroy horizons during sampling, making VOC
collection difficult. The bucket auger is therefore not
recommended for VOC collection; use a split-barrel
sampler instead. Bucket augers can be used for sludge
sampling in a surface impoundment, depending on
accessibility.
Bucket augers provide uniform sampling diameter and
good depth control, and are easy to decontaminate.
Their effectiveness is reduced in rocky or hard solids,
heavy clays, or very sandy solids.
Sampling Trier
A sampling trier is used to collect powdered or
granular materials from bags, fiber or metal drums,
sacks, or similar containers. A typical sampling trier
is a long tube with a slot which extends almost its
entire length. The tip and edges of the tube slot are
sharpened so that when rotated after insertion into the
material, the trier cuts out a sample core. Sampling
triers range from 24 to 40 inches in length and from
1/2 to 1 inch in diameter, and are usually made of
stainless steel (or a similar composition) with wooden
handles. Triers are relatively easy to use and to
decontaminate.
Waste Pile Sampler
The waste pile sampler is essentially a large sampling
trier used for sampling large waste piles (with cross-
sectional diameters greater than 1 meter). It can also
be used for sampling granular or powdered wastes,
and material in large bins or barges.
The waste pile sampler is commercially available, but
one can be easily and inexpensively fabricated from
sheet metal or plastic pipe. The sampler does not
collect representative samples when the diameters of
the solid particles are greater than one-half the
diameter of the tube.
Cork Screw Auger
The cork screw auger is a hand-driven sampler used to
sample bulk solid wastes such as waste piles. The
auger tip resembles a large drill bit ranging from 3/4
to 1-1/2 inches in diameter. The auger is used for
sampling at depth by adding rod extensions. It is
effective in soft to hard materials, although saturated
waste may be difficult to sample. Decontamination of
the auger is relatively easy. The cork screw auger
disturbs the waste profile and thus has limited utility
for VOC sampling.
Split-Barrel Sampler
The split-barrel sampler (also called a split-spoon
sampler) is used to collect waste samples from the
bottom of boreholes. The split-barrel sampler consists
of a hollow tube with a circular chisel or cutting shoe
threaded onto one end and a driving head or collet
threaded onto the other end. The sample tube is split
lengthwise into two halves to facilitate sample
removal and decontamination. A drilling rig is
required to use the split-barrel sampler. The sampler
is attached to the end of the drilling rod and is driven
into the bottom of the borehole with a specially
designed, 140-lb. drive hammer. The split-barrel
sampler can be used to determine the relative density
of the material that is being cored or drilled by
counting the number of drive hammer blows it takes
to drive the barrel 18 inches below the bottom of the
borehole.
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The split-barrel sampler is useful for collecting
relatively undisturbed waste samples from great
depths. Because split-barrel samplers do not disturb
the sample, they are suitable for sampling VOCs.
They can be used to sample deep into large waste
piles, subsurface wastes, or dry lagoon beds, but they
are not effective in rocky or very consolidated
materials.
3.3 EXAMPLE SITE
After conducting proper site entry procedures (health
and safely monitoring), the OSC utilized field
screening techniques to the greatest extent possible.
This allowed for the rapid collection of information to
support the decision-making process and to limit the
need for laboratory analysis. All waste streams were
screened (as discussed below) to determine which
laboratory analyses would be necessary, and to
provide a logical basis for selecting a limited number
of analytical parameters. All waste streams were also
screened for radiation; none was detected.
3.3.1 Drum Screening and Sampling
Equipment
Each of the closed drums appeared to be in relatively
good condition, showing no signs of internal pressure
or other instability, and were opened using a spark-
proof bung wrench. Five drums were already open to
the elements. After each drum was opened, samples
were collected for screening using a glass thief. All
drums were screened using haz-catting procedures.
All haz-catting information was recorded in the field
on a Hazard Categorization Data Sheet (illustrated in
Figure 8). The first haz-catting procedure conducted
was for pH. Four drums were found to contain strong
acids; five drums contained strong bases. Various
colorimetric tubes were used in an attempt to identify
specific acids; however, all the tubes exhibited
positive reactions due to interferences from the
presence of similar strong acids. Since cyanide-
bearing solutions are typically basic, all basic
solutions were screened for the presence of cyanide to
prevent the potential generation of hydrogen cyanide
gas (HCN) during handling. As a result of screening,
three drums containing basic solutions were
tentatively determined to contain cyanide. Additional
haz-cat screening (PID, FID, solubility, chlorine, and
peroxide) was conducted for the ten drums exhibiting
relatively neutral pH. From this additional screening,
three drums of oil, one drum of halogenated solvents,
and one drum of kerosene were tentatively identified.
Two drums were suspected to contain rainwater. The
screening results were inconclusive for three drums.
The drums containing strong acids and bases were, by
definition, RCRA hazardous characteristic wastes.
Because of the risks associated with strong acids and
bases, there was no need for further data analysis to
establish imminent threat. The entry team separated
incompatible materials to reduce the risk of a
chemical reaction/release.
3.3.2 Plating Vat Screening and
Sampling Equipment
Some plating vats were already open; others had large,
easy-to-open lids similar to that of a trash dumpster.
The vat liquids and bottom solids were screened
separately in the same manner as the drums, using a
COLIWASA-style glass thief to collect the samples
and haz-catting to identify the wastes. The samplers
were long enough to reach the bottom of the vats,
providing a sample of the entire vertical column of
liquid. A hollow glass thief was then used to collect
a single grab sample from the bottom solids in each
vat.
The vat contents were tentatively identified as strong
acids, strong bases, and cyanide bases. Haz-catting
results were inconclusive for four vats. No volatile
organic compounds were detected using PID and FID
instruments.
3.3.3 Waste Pile Screening and
Sampling Equipment
The piles contained blue and green solids that were
assumed to be bottom solids cleaned from the plating
vats. Screening samples from the waste piles were
collected using a corkscrew auger and stainless steel
trowels (because of the hardened texture of the piles).
Waste pile samples were haz-catted in the same
manner the samples from drums and vats. However,
since haz-cat tests are better suited to liquid matrix
waste streams, the two waste piles were difficult to
classify into general hazard categories.
Screening results indicated that the wastes were not
water reactive, flammable, combustible, or chlorine-
bearing; organic compounds were not detected.
Results of the cyanide test were positive. Sample
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color and other visual signs of contamination were
documented as the screening samples were collected.
3.3.4 Impoundment Screening and
Sampling Equipment
Screening samples were collected from both surface
impoundments. Waste liquids were sampled using a
bacon bomb sampler, and waste bottom sludges were
sampled using a Ponar dredge. Waste liquid samples
were taken from the center of each impoundment at
depths of 0 to 2 feet, and 2 feet to bottom. Five waste
sludge samples were collected from the bottom of
each impoundment at 20 foot intervals along a transect
established across each impoundment. A small
rowboat with stabilizing lines was moved along the
transects to collect screening samples.
Impoundment liquids were screened by haz-catting.
The results indicated that impoundment liquids
contained water and were slightly acidic, possibly
cyanide-bearing, non-flammable, and non-chlorinated.
The PID and FID did not detect any organic vapors,
suggesting a non-organic wastewater classification.
A chemical test kit was used to identify low levels of
specific metals in the impoundment liquids.
Screening of the bottom sludge had similar results,
except for a higher metals content and the positive
presence of cyanide.
3.3.5 Transformer Screening and
Sampling Equipment
The transformer top was removed using a standard
socket wrench. A transformer fluid screening sample
was collected using a makeshift sampling device
consisting of a clean, 4-oz sampling jar on a string.
The transformer was screened for PCBs using a PCB
screening kit. A grab sample was collected and the
test was performed on site following the directions
provided with the kit. The potential interferences
listed in the directions were determined not to apply to
this sampling event. The test indicated that the
transformer contained less than the 50 ppm total PCBs
action level (based on a colorimetric interpretation).
The sample fluid was placed back into the transformer
and the vessel was resealed.
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Figure 8: Example of a Hazard Categorization Data Sheet
HAZARD CHARACTERIZATION DATA Page of
Site: Date:
Sampler(s): Sample ID Number:
Phase: All Top Bottom N/A Sample Collected?: Yes No
HAZARD CHARACTERIZATION RESULTS
Soluble: Yes (dissolves/emulsifies in water) Heavier (than water) Lighter (than water)
pH: (if using instrument, round to nearest whole number)
Flammable: Yes No
Chlorine: Yes No
Oxidizer: Yes No
Cyanide: Yes No
Sulfide: Yes No
Other Test A:
Other Test B:
Action Taken: Overpacked Staged (location ) Bulked Other
Sort Class: (optionalspecify 2 character alphanumeric designator to assign user sort class)
SAMPLE DESCRIPTION
Color(s): Colorless White Yellow Blue Red Green Purple Brown Black Other
Clarity: Clear Cloudy Turbid (suspended solids) Opaque N/A (if solid)
Viscosity: Water Light Oil Heavy Oil Sludge N/A (if solid)
Impurities:
Comments:
Observations by:
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4.0 FIELD SAMPLE COLLECTION AND PREPARATION
4.1 INTRODUCTION
During a response action, proper field sample
collection and preparation is as important as proper
sampling equipment selection. Sample collection
refers to the physical removal of a portion of waste
material from its source for the purpose of either
screening or laboratory analysis. Field sample
preparation refers to all aspects of sample handling
from collection to the time the sample is received by
the laboratory. This chapter provides information on
sample collection and preparation for various waste
types and sources.
4.2 SAMPLE VOLUME
The volume of a sample should be sufficient to
perform all required laboratory analyses with an
additional amount remaining for analysis of QA/QC
samples (including replicate analyses). However,
because waste samples are generally of high
concentration, sample volumes should be kept to a
minimum (to minimize disposal costs). The EPA
method description and the laboratory receiving the
sample should be consulted for specific volume
requirements for each parameter.
Make an initial estimate of the volume or area of
waste represented by each sample. When obtaining
representative samples from waste which appears to
be relatively homogeneous, note the total waste
volume in cubic yards or gallons.
4.3 SOURCE SAMPLING
The following sections provide general information on
sampling several types of waste sources, including
drums, bulk storage tanks, lab packs, surface
impoundments, waste piles, surfaces, and debris. For
specific sampling information on these waste types,
refer to the Compendium of ERT Waste Sampling
Procedures, OSWER Directive 9360.4-07.
4.3.1 Drum Sampling
Each drum can have different contents and
concentrations, so each must be considered a unique
waste source. A site-wide representative sampling
approach is not appropriate. Screening techniques
should be used on the contents of each drum to
determine compatibility. This haz-cat information can
help determine whether bulking of wastes is
technically and economically feasible.
Drums may be sampled in place or staged in rows
prior to sampling, depending on their condition and
accessibility. If drums are stacked, a forklift or
grapple may be needed to move them for sampling.
(If drums cannot be safely moved, sample only
accessible drums.) When moving drums, document
on a site sketch their original locations. Number all
drums and record their label information on a drum
log sheet (see Chapter 2, Figure 6). Research all label
information to determine health and safety
precautions, including use of appropriate PPE. It does
not necessarily follow that the labels affixed to the
drums represent their actual contents. (Drums are
often reused without regard to proper rinsing and
relabelling procedures.) Further categorization is
necessary to determine or confirm drum contents
accurately. Be particularly cautious with drums that
have crystalline deposits or a precipitate around the
bung or lid. Some chemicals form a potentially
shock-sensitive, explosive, or reactive phase as they
degrade or react over time (e.g., picric acid forms
shock-sensitive crystals). Do not move drums in this
condition!
Bulging or misshapened drums and those with
unknown contents should be opened remotely. Rough
handling can trigger reactions which may cause them
to rupture. Open unknown or unstable drums
remotely. If drums contain a combination of solid,
liquid, or sludge wastes, separate sampling of each
phase may be necessary using chemically compatible
sampling equipment (e.g., COLIWASA or glass
thief). Where wastes are stratified, sample the top
stratum first to avoid mixing strata. Since each drum
may contain a different type of waste, it is usually not
29
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possible to make composites from separate drums
until the contents have been screened. As with most
containers, drums should be sampled through upper
bungs or openings whenever possible. Document
contents, physical characteristics (e.g., color,
viscosity) and field screening readings (e.g., FID,
PID, CGI).
Refer to Section 2.11.1 for a discussion of judgmental
sampling as it applies to drum sampling.
4.3.2 Bulk Storage Tank and
Transformer Sampling
Bulk storage tank sampling involves many of the
procedures and precautions noted for drum sampling.
Number and document each tank, noting National Fire
Protection Association (NFPA) 704 markings, if
present. Document available information on vessel
construction, tank location (e.g., in a tank farm), and
the presence of any secondary containment. Estimate
maximum tank volume using mathematical volume
equations (V=Br2h) or tank charts. Measure the
content volume using exterior level indicators, if
present.
Perform sampling through top hatches whenever
possible; avoid using bottom valves because a spill is
possible if the valve does not reseal. When there is
more than one phase, identify the distinct phases and
associated volumes. The objective is to identify
volume in gallons (liquids) or cubic yards (solids) to
determine the total waste volume that each sample
represents. Sample each phase separately, including
tank bottom sludges (use a bacon bomb sampler,
PACS grab sampler, or a sludge judge). Obtain a
sample from each compartment in multicompart-ment
tanks.
When sampling specialized tanks or transformers, it
may be necessary to use a manlift to gain access. Be
certain that transformers are "off-line" and de-
energized. Exercise spill control measures and ensure
secondary containment is in place around a
transformer before opening it. Access a transformer
through the top and collect a stratified sample.
4.3.3 Lab Pack Sampling
Initial inspection of lab packs may uncover packing
slips listing contents and associated volumes. The
packing slips may be affixed to the outside of the
drum or under the drum lid. If the labels on individual
containers are legible, inventory the containers and
repackage them in inert cushioning and absorbent
materials in accordance with 49 CFR 100-199. If the
label is illegible or missing, the lab pack should be
treated as an unknown. Unknowns are generally not
manually opened because of the potential health and
safety risks (exposure and reactivity). A safer
approach is to use remote opening or crushing
techniques and collecting the crushed containers and
their contents in an absorptive medium, which is then
sampled using a representative composite sampling
method.
4.3.4 Surface Impoundment
Sampling
When sampling a surface impoundment, consider its
characteristics, which include size, depth, flow, liquid
viscosity, bottom composition and whether a liner is
present. The bottom sludges and liquid phases may be
homogeneous or stratified.
Surface impoundments are often stratified by depth;
each phase should be sampled separately. Transect
sampling at various depths (including bottom sludge
sampling) is generally recommended. Horizontal
concentration gradients in the bottom sludges may be
present from the point where liquids enter the
impoundment. Vertical gradients may also be present
in bottom sludges. The logistics and health and safety
concerns of sampling large impoundments usually
dictate the use of manlifts, boats, and safety lines. If
a liner is present, take care to maintain its integrity.
4.3.5 Waste Pile Sampling
Waste pile sample collection techniques will depend
upon the sampling objective. If the objective is to
determine threat, grab sampling from the surface using
a waste pile sampler or a scoop/trowel might be
sufficient. If the objective is to obtain an average
concentration value for the entire pile for
treatment/disposal estimates, then the sampling should
include grab samples or composite aliquots collected
from the interior (using a waste pile sampler or an
auger) and the surface of the pile. Composite aliquots
collected at a given depth from several sides and the
top of the pile can be used to obtain an estimate of the
average pile concentration. The number of aliquots
collected will depend on many site-specific factors,
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including the size, composition, and accessibility of
the waste pile, as well as on budget considerations.
The surface of a pile continually weathers chemically
and physically. Depending on the size of the pile, it
may be divided into sections for compositing at
various depths. This will define an average
concentration for each section of the pile. For large
piles (e.g., large impoundment dredge or slag piles),
a three-foot depth is generally adequate to reach the
more representative materials. Extensive sampling of
a pile for both chemical and physical characteristics is
conducted during the evaluation of treatment and
disposal options. If the pile has been stabilized (e.g.,
cover, liner), do not collect samples that might breach
the integrity of the pile containment.
4.3.6 Surface Sampling
Special situations may present the need to sample
surfaces such as floors, walls, or equipment. When
sampling surfaces for contamination, choose sampling
points based on site history, manufacturing processes,
personnel practices, obvious contamination, and
available surface area. Where possible, collect
comparable media background samples from surfaces
unlikely to have been contaminated. This is
especially important when sampling for naturally
occurring substances such as metals.
Surface sampling includes wipe, chip, and dust
sampling. Analytical results for dust sampling are
reported in weight/weight; wipe sampling results are
reported in weight per unit area. Note that there are
very few action levels or health standards reported in
weight of contaminant per unit area to assist a Site
Manager in decision-making.
The methods of sampling described below are
appropriate for surfaces contaminated with non-
volatile species of analytes (e.g., PCBs, PCDD,
PCDF, metals, pesticides, cyanide). Detection limits
are analyte-specific. Determine sample size based
upon the detection limit desired, amount of sample
requested by the analytical laboratory, and sampling
locations and configuration.
Wipe Sampling
Wipe sampling is a method for collecting non-volatile
species of analytes from relatively smooth, non-
porous surfaces. It is appropriate for sampling walls,
floors, ventilation ducts and fans, empty transformers,
process equipment, and vehicles. Wipe sampling can
be used to confirm cleanup after steam cleaning or
decontamination of smooth building walls.
To collect a wipe sample, use a piece of sterile
medical gauze soaked in pesticide grade solvent (e.g.,
hexane, water, methanol, nitric acid). The type of
solvent used depends on the target analytes. When
requested in advance, analytical laboratories will often
prepare the gauze and sample jars. Use caution and
maintain proper safety protocols when handling
hexane and other solvents.
Several wipe sampling techniques were developed for
use in OSHA enforcement and industrial hygiene
decision-making to evaluate potential sources of
ingestion and direct contact exposures. Most of these
techniques recommend a uniform wipe area of at least
100 cm2, but larger areas may need to be wiped to
collect enough sample for the analytical method
detection limit. Disposable cardboard templates (or
glass or stainless steel templates which can be
decontaminated) are recommended to ensure a
uniform surface area. Very few approved standards or
action levels are available to compare with the wipe
sampling results (this supports qualitative rather than
quantitative conclusions). Wipe sampling is typically
used to determine if decontamination has been
effective or to select the type of disposal facility (e.g.
hazardous vs. non-hazardous). A blank consisting of
a solvent-soaked pad is required for each batch of
samples.
Sampling locations are typically judgmental
selections. They are chosen because they are areas of
highest suspected contamination (for disposal
decisions), or areas of suspected direct contact (for
exposure and hygiene evaluations).
Chip Sampling
Chip sampling is a method for collecting non-volatile
species of analytes from porous surfaces such as
cement, brick, or wood. Sample points include floors
near process areas, storage tanks, and loading dock
areas. Chip sampling is usually performed with a
hammer and chisel or with an electric hammer. It is
important to ensure that the chipping device does not
bias the integrity of the sample. Stainless steel tools
allow for easy decontamination and preparation for
reuse.
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To collect the sample, chip the desired sampling area
to a suitable depth (e.g., 1/8 inch). Gather the chips
and place them in a sample container using forceps, a
small scoop, or a dust pan. Make advance
arrangements with the analytical laboratory prior to
sampling to determine acceptable preparation and
analysis procedures. The laboratory may require
special grinding or extraction procedures.
Chip sampling is most often used to determine the
necessity or effectiveness of decontamination, or the
necessity for demolishing and disposing of a wall or
building. As with wipe sampling, existing action
levels may not be available for each application.
Make appropriate decisions based on precedents and
Regional guidelines.
Dust Sampling
Dust sampling is a method for collecting metal and
semi-volatile contaminants in residue or dust found on
porous or non-porous surfaces. Dust sampling
techniques are used where a solvent cannot be used or
where too much residue exists for a wipe sample to be
easily collected. Dust sampling is used in industry to
assess potential exposure of airborne contaminants to
workers. For example, dust sampling would be
effective in a bagging, processing, or grinding area
where powdery contaminants and dust may have
accumulated.
To collect a dust sample, select and sweep an
appropriate area using a dedicated brush and dust pan.
Transfer the sample to a sample container. Dust
sampling can also be conducted using a cellulose fiber
filter attached to a high-volume pump. Dust/residue
is vacuumed onto the filter.
Dust sampling results are reported in mg/kg
(weight/weight). The size of the area to be swept is
dependent on the sample volume needed for the
desired analysis and detection level. Dust sampling is
often used to assess potential respiratory, direct
contact, and ingestion hazards to workers and the
public. It may also be used to determine the need and
method for building decontamination.
4.3.7 Debris Sampling
The purpose of sampling waste debris is to select a
disposal option. Since debris often consists of
irregular pieces of material, it is a difficult matrix to
analyze in the laboratory. Provide the laboratory with
instructions to guide it in preparing a representative
subaliquot of debris samples for analysis.
Currently there are no standardized methods that
reliably conserve VOCs during the grinding of large
objects, nor are there good methods for extracting
non-polar organic contaminants from plastic matrices
without dissolving the plastic.
Use a judgmental sampling approach to sample debris,
selecting sampling locations by matrix and physical
properties. Use a chip sampling technique for porous
materials and wipe sampling for non-porous materials.
It is difficult to collect a representative sample of
debris because of its heterogeneous composition.
Compositing large objects will not result in
meaningful data, and obtaining a sample of different
components of debris is not always practical. Only if
feasible, separate debris into components (e.g., metal,
plastic, wood) and collect a representative surface
sample of each.
4.3.8 Compressed Liquid/Gas
Cylinders
Although dealing with compressed liquid/gas
cylinders is outside the scope of this document, they
are often found at waste sites. Compressed liquids
and gases are stored in a variety of low- and high-
pressure vessels or cylinders. Though the liquids or
gases in the cylinders are rarely considered to be
waste, the original cylinder may have been weakened
by exposure to heat, pressure, or outside
contamination. Cylinders represent a chemical,
explosion/fire, and projectile hazard. Compressed
liquids and gases, especially those in cylinders, should
be sampled only by specialists.
4.4 SAMPLE PREPARATION
Sample preparation depends on the sampling
objectives and analyses to be performed. Proper
sample preparation and handling maintain sample
integrity. Improper handling can render samples
unsuitable for analysis. For example, homogenizing
and compositing samples result in a loss of volatile
constituents and are thus inappropriate when volatile
contaminants are of concern. Sample preparation for
waste may include, but is not limited to:
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Removing extraneous material
Homogenizing
Splitting
Final preparation
Another field preparation technique is compositing of
samples, which requires that each discrete aliquot be
equal, and that the aliquots be thoroughly
homogenized. Compositing waste samples is
discussed in detail in Section 2.3.2.
4.4.1 Removing Extraneous Material
During sample collection, identify and discard
materials from the sample which are not relevant or
vital for characterizing the site, since their presence
may introduce an error into the sampling or analytical
procedures. Examples of extraneous material include
pieces of glass, twigs, or leaves. However, not all
external materials are extraneous. For example, when
sampling at a junkyard, lead-contaminated battery
casing pieces should not be removed from a sample if
the casing comprises more than 10 percent of the
sample volume. (For such a sample to be
representative, it must incorporate the lead from the
casing.) Collect samples of any material thought to be
a potential source of contamination. Discuss any
special analytical requirements for extraneous
materials with the project team (project management,
geologists, and chemists), and notify the laboratory of
any special sample handling requirements or method
changes.
4.4.2 Homogenizing
Homogenizing is the mixing or blending of a grab or
composite sample to distribute contaminants
uniformly within the sample. Ideally, proper
homogenizing ensures that all portions of the sample
are equal or identical in composition and are
representative of the total sample collected.
Incomplete homogenizing can introduce sampling
error. Homogenizing requires additional handling of
the waste and is not appropriate for all wastes. Unless
layered, liquid wastes can be assumed to be
homogeneous and do not require additional mixing.
If they occur in phases, treat each phase as a unique
homogeneous medium and sample each separately, as
discussed in Section 2.3.1. Solid samples that will be
composited should be homogenized after all aliquots
have been combined. Manually homogenize solid and
sludge samples using a stainless steel spoon or scoop
and a stainless steel bucket or pyrex bowl, or use a
disposable plastic scoop and pan, depending on the
analyses. Do not homogenize samples for VOC
analysis.
4.4.3 Splitting
After collection and field preparation, samples are
split into two or more equivalent parts when two or
more portions of the same sample need to be analyzed
separately. Split samples are most often collected in
enforcement actions to compare sample results
obtained by EPA with those obtained by the
potentially responsible party. Split samples also
provide measures of sample variability and analytical
error. Before splitting, follow the homogenization
techniques outlined above. Fill two sample collection
jars at the same time, alternating spoonfuls (or
scoopfuls) of homogenized sample between them.
Samples for VOC analysis should not be
homogenized; instead, collect two uniform samples
concurrently from the same location (collocated).
4.4.4 Final Preparation
Select sample containers on the basis of compatibility
with the material being sampled, resistance to
breakage, and capacity. Appropriate sample volumes
and containers will vary according to the parameters
being analyzed. Actual sample volumes, appropriate
containers, and holding times are specified in the U.S.
EPA Quality Assurance/Quality Control (QA/QC)
Guidance for Removal Activities, EPA/540/G-90/004,
April 1990, in 40 CFR 136, and in the Compendium
of ERT Waste Sampling Procedures, OSWER
Directive 9360.4-07. Package all samples in
compliance with current International Air Transport
Association (IATA) or Department of Transportation
(DOT) requirements, as applicable. Packaging should
be performed by someone trained in current DOT
shipping procedures.
Specific handling techniques may be required for
physical parameters such as permeability or particle
size distribution. Preservation of the original sample
conditions will determine in part the
representativeness of the analytical results.
Permeability is affected by evaporation and by
thermal variations; particle size is affected by
handling. In general, cooling samples can help
maintain original conditions; however, wastes are
33
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often of such high concentration that cooling a sample
is not necessary.
4.5 EXAMPLE SITE
Table 1 is a sample log for the ABC Plating site,
illustrating the parameters used by the analytical
laboratory to evaluate each waste source. The
analytical results provided preliminary information on
waste composition plus data necessary to begin clean-
up strategy and treatment/disposal planning. The
sampling objective of the initial assessment was to
establish threat.
4.5.1 Source Sampling
The following is a detailed description of the sampling
activities listed in Table 1.
Drum Sampling
Samples were collected from three drums tentatively
identified from screening results as containing cyanide
bases. They were sent for laboratory analysis of free
and total cyanide, TCL organic compounds, and
metals. Each sample was collected using a
COLIWASA sampler which preserved phase layers
that were present.
Vat Sampling
Samples were collected from two vats which were
tentatively identified as containing cyanide bases.
They were sent for laboratory analysis of free and
total cyanide and metals. Vat samples were assumed
to be relatively homogeneous and were collected
using a COLIWASA-style glass thief.
Waste Pile Sampling
Two composite samples were collected (one from
each waste pile) for laboratory analysis of free and
total cyanide and metals. For each pile, four aliquots
were collected from 12-inch depths at equally-spaced
points located along the previously established
transect. Sample aliquots were collected with a
corkscrew auger and a hard plastic scoop. Aliquots
from each pile were composited in separate disposable
plastic trays.
Impoundment Sampling
Two waste liquid samples and five waste bottom
sludge samples were collected from each
impoundment. Waste liquids were analyzed in the
laboratory for full TAL substances and the waste
sludges were laboratory analyzed for full TCL
substances. Sample locations and techniques were
identical to those chosen for initial screening (Section
3.3.4). Waste liquid samples were collected using a
bacon bomb sampler and waste sludge samples were
collected with a Ponar dredge.
Surface Sampling
Non-porous walls and the concrete slab floor in the
plating building were wipe and chip sampled,
respectively. A one-square foot template was used to
mark each area for wipe sampling. Sterile gauze pads
soaked in hexane were used to collect four samples
from non-porous walls. Four chip samples were
collected from the floor using block hammers and
chisels. Wipe and chip samples were analyzed for
metals and cyanide to determine if the facility block
walls and concrete floor needed to be sent to a secure
or sanitary chemical landfill.
4.5.2 Sample Preparation
Removing Extraneous Material
Drum, vat, and impoundment liquid samples did not
contain extraneous material. Stones and small pieces
of stainless steel wire were removed from solid
samples collected from the waste pile, but clumps of
blue-green solid material were not removed. Based on
screening data and knowledge of plating processes,
the clumps were suspected to be plating solids
containing high concentrations of metals and possibly
cyanide. Sticks and other extraneous materials (e.g.,
plastic and metal objects) were discarded from
dredged impoundment sludge samples. The presence
of extraneous materials was documented for later
consideration during treatment/disposal technology
evaluation.
Homogenizing Samples
Homogeneity was assumed for most liquid samples,
since plating processes require homogenous solutions
to promote for even ion movement and uniformity of
the coating. The liquid samples which appeared to be
34
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uniform were not homogenized. Several drums
containing liquid materials had distinct phases present
which were visible in the glass thieves during
sampling. Each phase was sampled separately using
a COLIWASA. The solid waste piles and
impoundment sludge samples were homogenized after
screening results indicated a lack of volatile organic
compounds. Since metals were a primary concern at
the site, pyrex mixing bowls (instead of disposable
aluminum pans) were used to homogenize samples.
Splitting Samples
At the request of the State, all initial containerized and
impoundment waste samples were split during the
removal assessment. The split samples were
preserved and labelled, then chain of custody
papersand samples were signed over to an on-site state
representative.
Table 1: ABC Plating Sample Log
Sampling Locations
Plating Vats
Drums
Waste Piles
Impoundment Liquids
Impoundment Sludges
Surfaces
Number of Samples
2
3
2
4
10
8
Analytical Parameters
metals, cyanide
metals, cyanide, full TCL
substances
metals, cyanide
full TAL substances
full TCL substances
metals, cyanide
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5.0 QUALITY ASSURANCE/QUALITY CONTROL
5.1 INTRODUCTION
The goal of representative sampling is to obtain
analytical results that accurately depict site conditions
during a given time. The goal of quality
assurance/quality control (QA/QC) is to implement
correct methodologies which limit the introduction of
error into the sampling and analytical procedures, and
ultimately into the analytical data.
QA/QC samples evaluate three types of information:
1) the degree of site variation; 2) whether samples
were cross-contaminated during sampling and sample
handling procedures; and 3) whether a discrepancy in
sample results is a result of laboratory handling and
analysis procedures.
digital values) in the form of paper printouts or
computer-generated electronic files. Data may be
generated at the site or at an off-site location, as long
as the QA/QC requirements are satisfied. For the data
to be definitive, either analytical or total measurement
error must be determined. QC measures for definitive
data contain all of the elements associated with
screening data, but also may include trip, method, and
rinsate blanks; matrix spikes; performance evaluation
samples; and replicate analyses for error
determination.
For further information on these QA/QC objectives,
please refer to EPA's Quality Assurance/Quality
Control Guidance for Removal Activities or EPA's
Data Quality Objectives Process for Superfund.
5.2 DATA CATEGORIES
EPA has established data quality objectives (DQOs)
which ensure that the precision, accuracy,
representativeness, and quality of environmental data
are appropriate for their intended application.
Superfund DQO guidance defines two broad
categories of analytical data: screening and
definitive.
Screening data are generated by rapid, less precise
methods of analysis with less rigorous sample
preparation. Sample preparation steps may be
restricted to simple procedures such as dilution with
a solvent, rather than elaborate extraction/digestion
and cleanup. At least 10 percent of the screening data
are confirmed using the analytical methods and
QA/QC procedures and criteria associated with
definitive data. Screening data without associated
confirmation data are not considered to be data of
known quality To be acceptable, screening data must
include the following: chain of custody, initial and
continuing calibration, analyte identification, and
analyte quantification. Streamlined QC requirements
are the defining characteristic of screening data.
Definitive data are generated using rigorous analytical
methods (e.g., approved EPA reference methods).
These data are analyte-specific, with confirmation of
analyte identity and concentration. Methods produce
tangible raw data (e.g., chromatograms, spectra,
5.3 SOURCES OF ERROR
The four most common potential sources of data error
in waste sampling are:
Sampling design
Sampling methodology
Sample heterogeneity
Analytical procedures
5.3.1 Sampling Design
Waste samples are often heterogeneous. Waste
components separate into phases or layers by specific
gravity and solubility. For example, an impoundment
may have an oily layer on top and relatively
contaminant-free water below. Failure to account for
differences in composition of multiple phases can
introduce sampling error. The sampling design must
account for all phases and strata which may contain
hazardous substances.
The sampling design should utilize approved SOPs
and previously approved sampling designs to ensure
uniformity and comparability between samples. The
actual sample collection process should be determined
prior to sampling. All samples should be collected
using a uniform surface area and/or depth to ensure
data comparability. Sampling equipment must be
standardized for like sampling situations.
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The sampling design should fulfill sampling and data
quality objectives. The QA objectives selected should
be built into the sampling design, including all
necessary QA/QC samples.
5.3.2 Sampling Methodology
Sampling methodology and sample handling
procedures have possible sources of error, including:
cross-contamination from inappropriate use of sample
collection equipment; unclean sample containers;
improper sampling equipment decontamination; and
improper shipment procedures. Procedures for
collecting, handling, and shipping samples should be
standardized to allow easier identification of any
source(s) of error, and to minimize the potential for
error. Use SOPs to ensure that all given sampling
techniques are performed in the same manner,
regardless of the individual sampling team, date, or
location of sampling activity. Use field blanks,
replicate samples, trip blanks, and rinsate blanks to
identify errors due to improper sampling methodology
and sample handling procedures.
Site screening and haz-catting often employ kits or
"cookbook" procedures requiring interpretations based
on chemical reactions which produce a color change.
The degree of subjectivity inherent in interpretation,
and the complexity of some of the procedures,
introduce a significant source of potential error.
5.3.3 Sample Heterogeneity
Wastes may become heterogeneous through
vaporization, settling, solubility, migration, or
addition of new wastes over time. Identify
heterogeneity by obtaining several samples or
composite aliquots from various depths.
Waste sources vary both in type and in concentration
level. Incorporate representative sampling techniques
into the sampling design to identify and define this
variation accurately. Collect a grab sample of each
phase or stratum suspected of containing contaminants
of concern; the samples will be relatively
homogeneous and representative of their respective
phases. For example, if an impoundment has three
liquid phases and sludge on the bottom, collect one
sample of each liquid phase and a sample of the
bottom sludge.
5.3.4 Analytical Procedures
Analytical procedures may introduce errors from:
laboratory cross-contamination; inefficient extraction;
and inappropriate methodology. High concentration
waste samples tend to foul analytical equipment,
which can lead to poor data reproducibility. Matrix
spike, laboratory duplicate, performance evaluation,
and laboratory control samples help to distinguish
analytical error from sampling error.
5.4 QA/QC SAMPLES
QA/QC samples are collected at the site or prepared
for or by the laboratory. Analysis of the QA/QC
samples provides information on the variability and
usability of waste sampling data, indicates possible
field sampling or laboratory error, and provides a
basis for future validation and usability of the
analytical data. The most common field QA/QC
samples are field replicate, background, and rinsate
blank samples. The most common laboratory QA/QC
samples are performance evaluation, matrix spike
(MS), and matrix spike duplicate (MSD) samples.
QA/QC results may suggest the need for modifying
sample collection, preparation, handling, or analytical
procedures if the resultant data do not meet site-
specific quality assurance objectives.
Waste is typically characterized by high
concentrations of contaminants, making precision and
accuracy less important than for samples with lower
concentrations (e.g., water, air). This eliminates the
need for frequent field blanks. In addition,
contaminant concentrations in waste samples are often
several orders of magnitude higher than the
concentrations of standard laboratory QA/QC mixes,
which may render them useless in measuring
laboratory error. The laboratory spikes are not
detected because of masking caused by the high
sample concentrations. Fouling of analytical
equipment associated with high concentration samples
may occur. Analytical error in waste sampling can be
measured by performance evaluation samples and
laboratory control samples, which are not subject to
matrix interferences.
Refer to data validation procedures in U.S. EPA
Quality Assurance/Quality Control (QA/QC)
Guidance for Removal Activities, EPA/540/G-90/004,
April 1990, for guidelines on utilizing QA/QC
37
-------
analytical results. The following sections briefly
describe the types of QA/QC samples appropriate for
waste sampling.
5.4.1 Field Replicate Samples
Field replicates, also referred to as field duplicates and
split samples, are field samples obtained from one
sampling point, homogenized (where appropriate),
divided into separate containers, and treated as
separate samples throughout the remaining sample
handling and analytical processes. Use replicate
samples to assess error associated with sample
heterogeneity, sample methodology, and analytical
procedures. Field replicates can also be used when
determining total error for critical samples with
contamination concentrations near the action level. In
such a case, a minimum of eight replicate samples is
recommended for valid statistical analysis. Field
replicates may be sent to two or more laboratories or
to the same laboratory as unique samples. For total
error determination, samples should be analyzed by
the same laboratory.
5.4.2 Collocated Samples
A collocated sample is collected from an area
adjoining a field sample to determine local variability
of the waste. Collocated samples of solids, such as
waste pile samples, are situated side by side.
Collocated samples of liquids, such as vat samples,
are collected from the same location and depth.
Collocated samples are collected and analyzed as
discrete samples; they are not composited. Because of
the non-homogeneous nature of many waste sources,
collocated samples should not be used to assess
variability within a large source and are not
recommended for assessing error. Determine the
applicability of collocated samples on a site-by-site
and source-by-source basis.
5.4.3 Background Samples
Waste sampling typically involves containerized or
relatively immobile waste streams. Background
sampling, which is appropriate when sampling soil,
surface water, groundwater, and air, has less
application to waste sampling. In some cases (e.g.,
uncontainerized waste) soil samples from
uncontaminated areas can serve as background
samples for waste sampling. Background samples are
appropriate for some surface sampling applications, as
discussed in Section 4.3.6.
5.4.4 Performance Evaluation/
Laboratory Control Samples
A performance evaluation (PE) sample evaluates the
overall error contributed by the analytical laboratory
and detects any bias in the analytical method being
used. PE samples contain known quantities of target
analytes manufactured under strict quality control.
They are usually prepared by a third party under an
EPA certification program. The samples are usually
submitted "blind" to analytical laboratories (the
sampling team knows the contents of the samples, but
the laboratory does not). Laboratory analytical error
may be evaluated by the percent recoveries and
correct identification of the components in the PE
sample.
A blind PE sample may be included in a set of split
samples provided to the PRP. The PE sample will
measure PRP laboratory accuracy, which may be
critical during enforcement litigation.
A laboratory control sample (LCS) also contains
known quantities of target analytes in certified clean
water. In this case, the laboratory knows the contents
of the sample; the LCS is usually prepared by the
laboratory. PE and LCS samples are not affected by
waste matrix interference, and thus can provide a clear
measure of laboratory error.
5.4.5 Matrix Spike/Matrix Spike
Duplicate Samples
Matrix spike and matrix spike duplicate samples
(MS/MSDs) are field samples that are spiked in the
laboratory with a known concentration of a target
analyte(s) in order to determine percent recoveries in
sample extraction. The percent recovery from
MS/MSDs indicates the degree to which matrix
interferences will affect the identification of a
substance. MS/MSDs can also be used to monitor
laboratory performance. When four or more pairs of
MS/MSDs are analyzed, the data obtained may also
be used to evaluate error due to laboratory bias and
precision. Analyze one MS/MSD pair to assess bias
for every 20 samples, and use the average percent
recovery for the pair. To assess precision, analyze at
least 8 matrix spike replicates from the same sample,
and determine the standard deviation and the
38
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coefficient of variation. See pages 9-10 of the U.S.
EPA Quality Assurance/Quality Control (QA/QC)
Guidance for Removal Activities, April 1990, for
directions on calculating analytical error. MS/MSDs
are recommended for screening data and are required
as one of several methods for determining analytical
error for definitive data. Since the MS/MSDs are
spiked field samples, provide sufficient volume for
three separate analyses. Because the spiking solutions
used in MS/MSDs are often obscured by high
concentrations of contaminants or by matrix effects,
the usefulness of MS/MSDs for high concentration
samples may be limited.
5.4.6 Rinsate Blank Samples
A rinsate blank is used to assess cross-contamination
from improper equipment decontamination
procedures. Rinsate blanks are samples obtained by
running analyte-free water over decontaminated
sampling equipment. Any residual contamination
should appear in the rinsate sample data. Analyze the
rinsate blank for the same analytical parameters as the
field samples collected that day. Handle and ship the
rinsate like a low-concentration field sample. Where
dedicated sampling equipment is not utilized, collect
one rinsate blank per sampling batch per day.
5.4.7 Field Blank Samples
Field blanks are samples prepared in the field using
certified clean water or sand which are then submitted
to the laboratory for analysis. A field blank is used to
evaluate contamination or error associated with
sampling methodology, preservation,
handling/shipping, and laboratory procedures. For
high-concentration samples, the usefulness of field
blanks is limited. Parts per billion (ppb) or low parts
per million (ppm) error has little significance when
identifying high concentration wastes or addressing
action levels in the hundreds of ppm. If available and
appropriate, submit one field blank per day.
5.4.8 Trip Blank Samples
Trip blanks are samples prepared prior to going into
the field. They consist of certified clean water or
sand, and are not opened until they reach the
laboratory. If available, utilize trip blanks to meet QA
objectives for volatile organic analyses only. Handle,
transport, and analyze trip blanks in the same manner
as the other volatile organic samples collected that
day. Trip blanks are used to evaluate error associated
with sampling methodology, shipping and handling,
and analytical procedures, since any volatile
contamination of a trip blank would have to be
introduced during one of those procedures. Since
waste samples are often high concentration, trip
blanks are not typically used during waste sampling.
5.4.9 Laboratory Duplicate Samples
A laboratory duplicate is a sample that undergoes
preparation and analysis twice. The laboratory takes
two aliquots of one sample and analyses them as
separate samples. Comparison of data from the two
analyses provides a measure of analytical
reproducibility within a sample set. Discrepancies in
duplicate analyses may indicate poor homogenization
in the field or other sample preparation error, either in
the field or in the laboratory. The benefit of
laboratory duplicates in waste sampling may be
limited. High concentration waste samples may foul
analytical equipment and result in unavoidably poor
reproducibility. Laboratory duplicates of high
concentration waste samples should not be used to
measure laboratory performance.
5.5 EVALUATION OF ANALYTICAL
ERROR
Analytical error becomes significant in decision-
making as sample results approach the action level.
The acceptable level of error is determined by the
intended use of the data and litigation concerns.
Definitive data require quantitative measurement of
analytical error with PE samples and replicates. The
other QA samples identified in this section can
indicate a variety of qualitative and quantitative
sampling errors. As discussed earlier, error in the ppb
or low ppm range may not be of concern when
analyzing high concentration wastes.
5.6 CORRELATION BETWEEN
FIELD SCREENING RESULTS
AND LABORATORY RESULTS
A cost-effective approach for evaluating wastes and
waste sources is to compare inexpensive field
screening data and other field measurements (e.g.,
XRF) with laboratory results. This relies in part on
39
-------
statistical correlation, which involves computing an
index called the correlation coefficient (r) that
indicates the degree and nature of the relationship
between two or more sets of values. The correlation
coefficient ranges from -1.0 (a perfect inverse or
negative relationship), through 0 (no relationship), to
+1.0 (a perfect direct or positive relationship). The
square of the correlation coefficient, called the
coefficient of determination, R2, is an estimate of the
proportion of variance in one variable (the dependent
variable) that can be accounted for by the independent
variables. An acceptable R2 value depends on the
sampling objectives and intended data uses. As a rule,
statistical relationships should have an R2 value of at
least 0.6 to determine a reliable model. For health or
risk assessment purposes, the acceptable R2 value may
be more stringent (e.g., 0.6). Analytical calibration
regressions have an R2 value of 0.98 or greater. Once
a reliable regression equation has been derived, the
field screening data can be used to predict laboratory
results. These predicted values can then be located on
a base map and contoured (mapping methods are
described in Section 6.4). The contour maps can
illustrate the estimated extent of contamination (for
certain waste sources) and the adequacy of the
sampling program.
5.7 EXAMPLE SITE
5.7.1 QA Objectives
Screening data, which generate non-definitive,
unconfirmed results (e.g., total hydrocarbons, total
halogens, cyanide, PCBs) were used to select
analytical parameters. Samples were sent to the
analytical laboratory under protocols which provided
definitive data. The rigorous laboratory analyses
provided definitive identification and quantitation of
contaminants (e.g., 50 ppm benzene, 110 ppm total
chromium, 75 ppm total cyanide).
5.7.2 Sources of Error
All direct reading instruments were maintained and
calibrated in accordance with their instruction
manuals. Many of these instruments are class-specific
(e.g. volatile organic vapors) with relative response
rates that are dependent on the calibration gas
selected. Instrument response to ambient vapor
concentrations may differ by an order of magnitude
from response to calibration standards. If compounds
of interest are known, site-specific standards may be
prepared; they are most applicable for field gas
chromatographs (GCs). These standards can be
prepared on site in a gas bag or flask, but have limited
holding times. Preparation of standards on site
introduces its own potential error. For sites of long
duration, specialty mixtures may be ordered from a
specialty gas company or an analytical laboratory.
The number and location of initial field samples were
based on observation and professional judgment (as
outlined in Section 2.8). Liquid wastes in the vats,
impoundments, and transformers were assumed to be
homogeneous because there were no visible phases.
(An erroneous observation could introduce significant
error into the sampling design.)
Field standard operating procedures, documented in
the site sampling plan, established consistent
screening and sampling procedures among all
samplers. This reduced the chances for variability and
error during sampling. Site briefings were conducted
prior to all sampling and screening events to review
the use of proper screening and sampling techniques.
Other steps taken to limit error included proper
sample preparation, adherence to sample holding
times, and the use of proper shipment procedures. All
off-site laboratory sample analyses were performed
using EPA standard methods and protocols.
5.7.3 Field QA/QC Samples
Few field QA/QC samples were collected during
waste sampling at the ABC Plating site. For the low-
concentration impoundment liquids, a PE sample for
metals was sent to the laboratory. (The PE sample is
not affected by matrix interferences.) Field and trip
blanks were not applicable since they are used to
determine cross-contamination of low concentration
samples. Cross-contamination that may occur during
storage and shipping is minimal compared to the high
ppm or percent level concentrations which are
typically found in plating wastes. Nevertheless,
suspected high concentration samples were shipped
separately from the low level samples. One rinsate
blank sample was collected from the impoundment
sampling equipment (dredge and bacon bomb
samplers) to check for cross-contamination during
equipment decontamination.
40
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5.7.4 Laboratory QA/QC Samples
Instructions on matrices, target compounds, and
QA/QC criteria of particular interest were provided to
the laboratory to help ensure that analytical results
met the required objectives. The laboratory was
instructed to run a duplicate of LCS samples for each
batch of high concentration liquid vat samples to
check reproducibility of the laboratory results. A
matrix spike was not requested because the level of
error measured by the standard low/medium spiking
mixtures did not apply to the expected high
concentrations in the samples. The laboratory
analyzed the metals using the methods of inductively
coupled plasma (ICP) spectrometry and atomic
absorption (AA). The presence of cyanide was
confirmed in the laboratory using total and amenable
cyanide analyses (colorimetric manual method, SW-
846 Method 9010).
PE sample results indicated low recoveries for some
metals. The difference between LCS duplicate results
was within the acceptable range, so these results were
used as estimates with a low bias. The confirmation
by a second method on 10 percent, or one per batch, of
the high concentration samples indicated acceptable
accuracy.
The waste pile was thought to be vat bottom materials
of high contaminant concentrations, therefore a matrix
spike was not requested. An LCS duplicate was used
to evaluate the reproducibility of the results and to
establish if the solid samples were homogeneous.
Agreement between the LCS duplicates indicates
good laboratory precision. When results of the LCS
and LCS duplicate correlate, but the field replicates do
not, two possible errors are indicated: either the
matrix interfered with recovery, or there was poor
sample homogenization in the field. The laboratory
does not homogenize samples unless specified in the
analytical method.
For the impoundment samples, matrix spike and LCS
duplicate samples were used. Matrix spikes are
applicable since the impoundment samples have a
lower concentration than the vat samples. Matrix
spike recoveries for certain metals were low.
However, LCS results were within control limits,
indicating good laboratory performance.
41
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6.0 DATA PRESENTATION AND ANALYSIS
6.1 INTRODUCTION
6.4 CONTOUR MAPPING
Data presentation and analysis techniques are
performed with analytical, field screening, or
geophysical results. The techniques discussed below
can be used to compare analytical values, to evaluate
numerical distribution of data, and to reveal the
location of "hot spots" and the extent of contamination
at a site. The appropriate methods to present and
analyze sample data depend on the sampling
objectives, the number of samples collected, the
sampling approaches used, and other considerations.
6.2 DATA POSTING
Data posting involves placement of sample values on
a site base map or cross-section. Data posting is
useful for displaying the distribution of sample values,
visually depicting the location of wastes with
associated assessment data. Data posting requires
each sample to have a specific location (e.g., x, y, and
sometimes z coordinates). Ideally, the sample
coordinates are surveyed values or inventoried and
numbered containers, facilitating placement on a
scaled map. Data posting is useful for depicting
concentration values of non-containerized wastes and
surfaces, but has limited application to containerized
wastes.
6.3 CROSS-SECTION/FENCE
DIAGRAMS
Cross-section diagrams (two-dimensional) and fence
diagrams (three-dimensional) depict layers or phases
of wastes in sources such as tanks and impoundments.
Two-dimensional cross-sections may be used to
illustrate vertical profiles of waste concentrations in
containerized wastes or impoundments. For solid
wastes in waste piles, three-dimensional fence
diagrams are often used to interpolate data between
sampling locations. Solid wastes in waste piles do not
usually form horizontal layers, so fence diagrams
based on a few sampling points may not be
representative. Both cross-sections and fence
diagrams can provide useful visual interpretations of
contaminant concentrations.
Contour maps are useful for depicting contaminant
concentration values in waste piles or impoundments.
Contour mapping requires an accurate, to-scale
basemap of the site. After data posting sample values
on the basemap, insert contour lines (or isopleths) at
a specified contour interval, interpolating values
between sample points. Contour lines can be drawn
manually or can be generated by computer using
contouring software. Although the software makes
the contouring process easier, computer programs
have a limitation: as they interpolate between data
points, they attempt to " smooth" the values by fitting
contour intervals to the full range of data values. This
can result in a contour map that does not accurately
represent general site contaminant trends. Typical
waste sites have low concentration/non-detect areas
and "hot spots." If there is a big difference in
concentration between the waste "hot spot" and the
surrounding area, the computer contouring program,
using a contour interval that attempts to smooth the
"hot spots," may eliminate most of the subtle site
features and general trends. For waste sampling,
contouring may apply only to large waste piles and
impoundments.
6.5 STATISTICAL GRAPHICS
If using statistical interpretation, the distribution or
spread of the data set is important in determining
which statistical techniques to use. Common
statistical analyses, such as the t-test, rely on normally
distributed data. The histogram is a statistical bar
graph which displays the distribution of a data set. A
normally distributed data set takes the shape of a bell
curve, with the mean and median close together about
halfway between the maximum and minimum values.
A probability plot depicts cumulative percent against
the concentration of the contaminant of concern. A
normally distributed data set, when plotted as a
probability plot, would appear as a straight line. A
histogram or probability plot can be used to see trends
and anomalies in the data from a waste source (e.g.,
impoundment) prior to conducting more rigorous
forms of statistical analysis. As with contour
mapping, statistical data interpretation applications for
waste are limited.
42
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6.6 RECOMMENDED DATA
INTERPRETATION METHODS
The data interpretation methods chosen depend on
project-specific considerations, such as the number of
sampling locations and their associated range in
values. Data which are dissimilar in composition
(e.g., drums with different chemicals or different
waste media) should not be compared using statistical
interpretation methods. Data posting, screening, and
sampling data sheets, and cross-section/fence
diagrams may be appropriate. A site feature depicting
extremely low data values (e.g., non-detects), together
with significantly higher values (e.g., 5000 ppm) from
neighboring "hot spots" with little or no concentration
gradient in between, does not lend itself to contouring.
6.7 EXAMPLE SITE
Figure 9 illustrates a transect of impoundment No. 1 in
a two-dimensional cross-section. The sampling
intervals are indicated by the twenty foot markings
along the transect of the cross-section. Analytical
results were data posted on the cross-section to
illustrate contaminant trends. Contaminant volume
can be visualized by depicting both the sludge layer
and impoundment bottom. The bottom sludges
contained 300 to 427 ppm total chromium; other
parameters exhibited a similar concentration gradient
range.
Table 2 presents the haz-catting results of all
containerized waste and waste piles on site. This
table was generated as the initial step in analyzing the
data prior to posting on the base map and lists results
from several different tests. These data were then
posted on the base map.
43
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Figure 9: Posted Total Chromium Data for Impoundment No. 1
4O
8O ft.
427 ppm
411 ppm
377 ppm
is sludge sample point
(Tj) liquid sample point
'' ..... -,_ sludge surface
Impoundment bottom
377 ppm total chromium concentration
PPm
Vertical scale exaggerated ~3X
44
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Table 2: Haz-Cat Results
ABC Plating Site
(page 1 of 2)
Container
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
D11
D12
D13
D14
D15
D16
D17
D18
ni9
Rad
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
pH
12
>12
>12
>12
6
7
7
7
7
N/A
5
5
5
5
<2
<2
<2
<2
>11
CN
Y
Y
Y
N
N/A
N/A
N/A
N/A
N/A
N
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N
PID
N/A
N/A
N/A
N/A
4
18
26
14
45
18
6
8
ND
ND
N/A
N/A
N/A
N/A
N/A
FID
N/A
N/A
N/A
N/A
2
35
70
39
128
26
11
6
ND
ND
N/A
N/A
N/A
N/A
N/A
Solubility
in water
Y
Y
Y
Y
Y
N Floats
N Floats
N Floats
N Sinks
Y
Y
Y
Y
Y
Reacts
Reacts
Reacts
Reacts
Y
Chlorine
Test
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Peroxide
Test
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Phase
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
S
Cu+
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Comments
cyanide base
cyanide base
cyanide base
base
inconclusive
oil
oil
oil
halogenated
solvent
kersosene
open; rain water?
open; rain water?
inconclusive
inconclusive
strong acid
strong acid
strong acid
strong acid
caustic soda
45
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Table 2: Haz-Cat Results (Cont'd)
ABC Plating Site
(page 2 of 2)
Container
V1
V2
V3
V4
V5
V6
V7
V8
V9
V10
V11
V12
V13
V14
V15
P1
P2
Rad
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
pH
>12
>12
9
2
2
8
2
2
8
<2
<2
8
<2
<2
>12
N/A
N/A
CN
Y
Y
N
N
N
N
N
N
N
N
N
N
N
N
N
Y
Y
PID
N/A
N/A
ND
N/A
N/A
ND
N/A
N/A
ND
N/A
N/A
ND
N/A
N/A
N/A
ND
ND
FID
N/A
N/A
ND
N/A
N/A
ND
N/A
N/A
ND
N/A
N/A
ND
N/A
N/A
N/A
ND
ND
Solubility
in water
Y
Y
Y
Y
Y
Y
Y
Y
Y
Reacts
Reacts
Y
Reacts
Reacts
Y
N
N
Chlorine
Test
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Peroxide
Test
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N/A
N/A
Phase
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
S
S
Cu+
N
N
N
N
N
N
N
N
N
Y
Y
N
N
N
N
N/A
N/A
Comments
cyanide base
cyanide base
inconclusive
acid
acid
inconclusive
acid
acid
inconclusive
strong acid
strong acid
inconclusive
strong acid
strong acid
strong base
inconclusive
inconclusive
ND - none detected
NA - not applicable
L - liquid
S - solid
Y - yes
N - no
46
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APPENDIX A -- Example of Flow Diagram For Conceptual Site Model
Figure A-1
Migration Routes of a Gas Contaminant
from Origin to Receptor
Original state
of contaminant
of concern*
Gas**
>
Pathway
from
origin
Air
condc
solldl
Change of
contaminant
state In
pathway
jnsatlon
> Liquid
k Hnc**
> dab
> Solid
Flcatlon
Final
pathway
to receptor
> SO
> SW
> so
> AT
> AA j.
^ SW
1 > so
1 ^ sw
Receptor
Human
G,D
G,D
I,D
I,D
G,D
G,D
G,D
Ecological Threat
Terrestrial
G,D
G,D
I,D
I,D
I,D
G,D
G,D
Aquatic
N/A
G,D
N/A
N/A
G,D
N/A
G,D
* May be a transformation product
** Includes vapors
Receptor Key
D = Dermal Contact
] = Inhalation
G - Ingestlon
N/A - Not Applicable
Pathway Key
AI =Alr
SO = Soil
SW - Surface Water
(Including sediments)
GW - Ground Water
47
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Figure A-2
Migration Routes of a Liquid Contaminant
from Origin to Receptor
Change of
Original state Pathway contaminant
of contaminant from state In
of concern* origin pathway
Liquid
* May be a t
** Includes v
> Liquid
-* SW t fiac**
solidification ^O-1-10
kQO h 1 i n 1 1 1 H
r OU . . . * I_-LUU-LU
leachate,
Infiltration
> AT t fiac**
Mฑ f Vjdo
ransformation product
apors
Final
pathway
to receptor
> SW
k AT
' Al
k O\A/
^ oW
> SW
>> SO
>> SW
* GW
> SO
> AI
^ SW
neceptor
Human
G3D
I,D
G,D
G,D
Ecological Threat
Terrestrial
G,D
I,D
G,D
G,D
Aquatic
G,D
N/A
G,A
G,D
G,D
G,D
G,D
G,D
G,D
N/A
N/A
G,D
N/A
G,D
I,D
G,D
G,D
I,D
G,D
N/A
N/A
G,D
Receptor Key
D - Dermal Contact
I - Inhalation
G - Ingestlon
N/A - Not Applicable
Pathway Key
AI . Air
SO - Soil
SW - Surface Water
(Including sediments)
GW -Ground Water
48
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Figure A-3
Migration Routes of a Solid Contaminant
from Origin to Receptor
Original state
of contaminant
of concern*
Solid
AI
partlculates/
dust
SW
Solid
Solid
Liquid
**
Solid
Liquid
* May be a transformation product
** Includes vapors
AI
SW
SO
SW
SW
so
AI
SW
so
SW
Receptor Key
D - Dermal Contact
I - Inhalation
G - Ingestlon
N/A - Not Applicable
Pathway Key
AI . Air
SO - Soil
SW - Surface Water
(Including sediments)
GW - Ground Water
Receptor
Human
IiD
G,D
G,D
Ecological Threat
Terrestrial
I,D
G,D
G,D
Aquatic
N/A
G,D
N/A
G,D
G,D
G,D
G,D
G,D
G,D
G,D
I,D
G,D
G,D
G,D
G,D
G,D
G,D
I,D
G,D
G,D
G,D
N/A
G,D
N/A
N/A
G,D
N/A
N/A
N/A
G,D
49
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