United States EPA/625/12-91/002
Environmental Protection November 1991
Agency
Technology Transfer
Description and
Sampling of
Contaminated Soils
A Field Pocket Guide
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Technology Transfer EPA/625/12-91 /002
&EPA Description and
Sampling of
Contaminated Soils:
A Field Pocket Guide
Center for Environmental Research Information
U.S. Environmental Protection Agency
26 West Martin Luther King Drive
Cincinnati, OH 45268
rJ5y Printed on Recycled Paper
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Notice
This guide has been reviewed by the U.S. Environmental
Protection Agency and approved for publication. Mention of
trade names or commercial products does not constitute
endorsement or recommendation for use.
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Contents
Page
How to Use This Guide ix
Chapter 1. Field Methods, Equipment,
and Documents 1
1.1 Nature of Soil Pollutants* and Surface
Pollution Situation* 1
1.2 Soil Parameters for Field Sampling and
Characterization 2
1.3 Field Description of Soils 3
1.4 Field Sampling and Testing 5
1.5 Field Equipment and Documents 5
1.6 Use of EPA's Environmental Systems
Monitoring Laboratory 6
Chapter 2. Site Characteristics... 19
2.1 Climate and Weather* 19
2.1.1 Air Temperature 20
2.1.2 Wind Speed and Direction* 20
2.1.3 Humidity 20
2.2 Slope* 21
2.3 Surface Erosion and Erodibility* 22
2.4 Surface Runoff* 23
2.5 Vegetation* 24
2.6 Macro- and Mesofauna* 26
Chapter 3. Field Description and
Analysis of Soils 27
3.1 Soil Physical Parameters 28
3.1.1 Soil Horizons* 31
3.1.2 Soil Texture Classes* 38
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iv
Page
3.1.3 Soil Color* 41
3.1.4 Soil Porosity* 46
3.1.5 Zones of Increased
Porosity/Permeability 48
3.1.5a Soil Structure Grades* 49
3.1.5b Extrastructural Cracks 49
3.1.5c Roots* 53
3.1.5d Surface Features* 53
3.1.5e Sedimentary Features 54
3.1.6 Zones of Reduced
Porosity/Permeability 55
3.1.6a Genetic Horizons 55
3.1.6b Rupture Resistance
(Consistency*) 56
3.1.6c Bulk Density* 58
3.1.6d Root Restricting Layers 60
3.1.6e Penetration Resistance
(Compaction*) 60
3.1.7 Soil Engineering Parameters and
Properties 62
3.1.7a Unified (ASTM) Texture 62
3.1.7b Atterberg Limits 69
3.1.7c Shear Strength 69
3.1.7d Shrink-Swell 70
3.1.7e Corrosivity* 70
3.1.8 Soil TemperatureVTemperature
Regime* 71
3.2 Soil Hydrologic Parameters 73
3.2.1 Moisture Conditions*
(Soil Water State) 73
3.2.2 Water Table (Internal Free Water
Occurrence) 75
3.2.3 Available Water Capacity 76
3.2.4 Saturated Hydraulic Conductivity*
and Soil Drainage Class 76
3.2.5 Infiltration* 77
3.3 Soil Chemistry and Biology 81
3.3.1 Organic Matter* 81
3.3.2 Odor* 83
3.3.3 Cation Exchange Capacity* 84
3.3.4 Reaction (pH)* 84
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Page
3.3.5 Redox Potential* (Eh) 85
3.3.6 Electrical Conductivity* (Salinity) 85
3.3.7 Clay Minerals* 86
3.3.8 Other Minerals 87
3.3.9 Fertility Potential* 90
3.3.10 Soil Microbiota* 91
3.4 Soil Contaminants 92
Chapter 4. Soil Sampling and Quality
Assurance 93
4.1 Changes in Soil Sampling Procedures 93
4.2 Quality Assurance/Quality Control 94
References
References 102
Appendices
A.1 General Protocol for Description of
Soil Cores 106
A.2 General Protocol for Soil Sample
Handling and Preparation 110
A.2.1 Soil Sample Collection Procedures
for Volatiles 110
A.2.2 Soil Sample Collection and
Mixing Procedures for Semivolatiles
and Metals 111
A.2.3 Equipment
Decontamination/Disposal 112
A.2.4 Air Drying 113
A.3 General Protocol for Soil Sampling with
a Spade and Scoop 116
A.4 General Protocol for Soil Sampling with Augers
and Thin-Walled Tube Samplers 118
B. Manufacturers and Distributors of Soil
Sampling Equipment 120
'Indicates that guidance for interpretation of
observations and measurements can be found in
Cameron (1991).
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'X'X'X*:*:^^
Forms
Page
1 -1 Checklist of Soil Physical and Chemical
Property Sampling and Field
Test Procedures 7
1 -2 Soil Description/Sampling Equipment and
Documents Checklist 8
1 -3 Soil Sampling Quality Assurance/Quality
Control Checklist 13
1 -4 Coding Sheet for ESES Site
Knowledge Frames 15
1-5 Coding Sheet for ESES Soil
Knowledge Frames 16
3-1 Soil Profile and Related Information 29
3-2 Unified (ASTM) Field Texture
Determination Form 63
4-1 Sample Alteration Form 99
4-2 Field Audit Checklist 100
4-3 Sample Corrective Action Form 101
Tables
1 -1 Suggested Soil Parameters for
Field Description 4
2-1 Index Surface Runoff Classes 25
2-2 Criteria for Placement of Hydrologic
Soil Groups 25
3-1 Definitions and Designation Nomenclature
for USDA Soil Horizons and Layers 32
3-2 Comparison of the 1962 and 1981 USDA
Soil Horizon Designation Systems 35
3-3 Subdivisions of the C Horizon
Used in Illinois 37
3-4 Abbreviations and Designations for USDA
Soil Texture Classes
(including coarse fraction) 40
3-5 Rupture Resistance Classes 57
3-6 Field Estimation of Soil Shear Strength 69
3-7 Guide for Estimating Risk of Soil
Corrosion Potential of Uncoated Steel 72
3-8 Water State Classes 74
3-9 Guide for Estimating the Class of Saturated Vertical
Hydraulic Conductivity from Soil Properties 78
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Page
3-10 Criteria for SCS Soil Drainage Classes 79
4-1 Summary of Hand-Held Soil
Sampling Devices 95
4-2 Summary of Major Types of Power-Driven
Tube Samplers 97
A-1 EPA Recommended Sampling Containers,
Preservation Requirements, and Holding
Times for Soil Samples 114
B-1 Manufacturers and Distributors of Soil Sampling
Equipment 120
Figures
3-1 USDA soil texture triangle 39
3-2 Percentage of sand sizes in subclasses
of sand, loamy sand, and sandy loam basic textural
classes 42
3-3 Charts for estimating proportions of coarse
fragments and mottles 43
3-4 Guide for designation of mottle contrast 45
3-5 Charts for estimating pore and root size 47
3-6 Drawings illustrating some of the types of
soil structure 50
3-7 Charts for estimating size class of different
structural units 51
3-8 Summary of field tests for Unified (ASTM) soil
textural classification 64
vii
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via
Acknowledgments
This document was prepared for EPA's Center for Environmen-
tal Research Information, Cincinnati, Ohio, and the Exposure
Assessment Research Division of EPA's Environmental Monitor-
ing Systems Laboratory, Las Vegas, Nevada.
Author:
J. Russell Boulding, Eastern Research Group, Inc.
(ERG), Arlington, Massachusetts
Project Management:
Carol Grove, EPA CERI, Cincinnati, Ohio
J. Jeffrey van Ee, EPA ORD, Environmental Monitoring
Systems Laboratory, Las Vegas, Nevada
Heidi Schultz, ERG, Arlington, Massachusetts
Editing and Production:
Susan Richmond, ERG, Arlington, Massachusetts
David Cheda, ERG, Arlington, Massachusetts
Reviewers:
Noel Anderson, Geraghty and Miller, Madison, Wisconsin
Robert Breckenridge, Idaho National Engineering
Laboratory, Idaho Falls, Idaho
Roy Cameron, Lockheed Engineering & Sciences Com-
pany, Las Vegas, Nevada
H. Raymond Sinclair, Jr., Soil Survey Interpretations and
Geography Staff, USDA SCS National Soil Survey
Center, Lincoln, Nebraska
Bobby Ward, State Soil Scientist, USDA Soil Conserva-
tion Service, Indianapolis, Indiana
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How to Use This Guide
This guide describes many field methods and procedures
that can be used for (1) preliminary site reconnaissance,
(2) detailed site and contaminant characterization/sampling
for transport/fate modeling and risk assessment, and (3)
remediation selection and design.
All methods and procedures described in this guide
are simple and inexpensive. When used early in site
reconnaissance, site characterization, or remediation
projects, the methods in the guide may reduce project
costs by providing a basis for more efficient application of
more complex and expensive field methods, when they
are needed.
This guide has also been designed to serve as a
companion to EPA's Guide to Site and Soil Description
for Hazardous Waste Site Characterization (Cameron,
1991), which also serves as the basis for the site and soil
components for metals of the Environmental Sampling
Expert System (ESES) under development by EPA's
Environmental Monitoring Systems Laboratory, Las
Vegas.
Use for Preliminary Site Reconnaissance. If a
soil survey prepared by the Soil Conservation Service
(SCS) of the U.S. Department of Agriculture is available
for the site, this guide in combination with Cameron (1991)
can be used to develop preliminary interpretations
concerning the potential for site and soil conditions to
facilitate or inhibit contaminant transport.
Use for Detailed Site and Contaminant
Characterization:
1. To assist field personnel in preparing for a visit to a
contaminated site by providing checklists to ensure
that no documents or equipment are accidentally
left behind (see Forms 1-2 and 1-3 in Chapter 1).
Ix
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2. To provide a concise, but comprehensive,
reference source for methods of describing and
analyzing site and soil characteristics in the field
that require only visual/tactile observation or very
simple equipment. Chapter 2 provides this
information for site characteristics. Chapter 3
provides this information for soil characteristics,
placing special emphasis on soil description
procedures of the U.S. Soil Conservation Service.
Abbreviations and codes that can be used for
specific soil features are suggested to facilitate
notetaking. Where soil conditions favor use of a
soil probe (no coarse fragments), description
procedures outlined in Appendix A.1 may be useful
for characterizing soils at a site prior to sampling
for detailed chemical characterization.
3. To assist in selecting and obtaining alternative soil
sampling equipment if unforeseen problems at the
site prevent use of sampling procedures specified
in the Soil Sampling and Quality Assurance Plans.
Chapter 4 provides information on sampling
equipment characteristics. A series of Appendices
describe some standard soil sampling and
handling protocols that may help address quality
control concerns related to alternative procedures
that may be required by unforeseen site conditions.
4. To facilitate use of EPA's Environmental Sampling
Expert System (see Section 1.6).
Use for Modeling and Remediation
Selection/Design. When site soil parameters that are
required for modeling or remediation selection/design are
known, the appropriate sections of this guide can be used
for data collection. Characterizing Soils for Hazardous
Waste Site Assessments (Breckenridge et al., 1991) and
Cameron (1991) may assist in identifying soil parameters
of interest.
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Chapter 1
Field Methods, Equipment,
and Documents
This chapter provides tables and checklists that can be
used to help select specific field methods, and to iden-
tify equipment and documents that should be assembled
prior to going into the field.
1.1 Nature of Soil Pollutants and Surface
Pollution Situation
Before beginning field sampling and charac-
terization, it is necessary to have some knowledge of the
nature of soil pollutants at a site, whether they are heavy
metals, toxic organics, or both, and of the areal extent of
pollution. EPA's Environmental Sampling Expert System
(ESES) defines two major types of surface pollution situa-
tions related to the areal distribution of the contaminants:
(1) large (covers a wide area, primarily on the surface),
and (2) localized (areas usually polluted near the source).
Once all available site information has been
evaluated, an exploratory soil sampling program may be
undertaken to further define the nature and extent of soil
pollutants, before developing a detailed soil sampling plan.
Soil descriptions of near-surface soil cores (1.5 to 2 m)
taken on a grid at the site using procedures described in
Appendix A.1 may provide valuable additional information
at relatively low cost prior to developing either an ex-
ploratory or detailed soil sampling plan.
Existing data, or soil sampling results, will indicate
the nature of pollutants. Specific contaminants of concern
are broadly defined in EPA's ESES as relatively mobile
and toxic (residence time in the solid phase is relatively
short, enhancing toxicity) or relatively nonmobile and
nontoxic (residence time in the solid phase is relatively
long, decreasing potential toxicity).
Field Methods, Equipment, and Documents 1
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Field Methods, Equipment, and Documents 2
1.2 Soil Parameters for Field Sampling and
Characterization
This field guide assumes that:
1. Physical, hydrologic, and chemical/biological
parameters of soils and contaminants have been
selected for description and sampling prior to the
field collection phase for characterization of a con-
taminated site.
2. These parameters and methods or protocols are
contained in statistically sound and detailed Soil
Sampling and Quality Assurance Plans for the site.
Guidance for the preparation of such plans can be
found in Mason (1983), Barth et al. (1989), van Ee
et al. (1990), and U.S. EPA (1986, Vol. 2, Chap. 9).
Appendix D in a companion document to this field
guide, Guide to Site and Soil Description for Hazard-
ous Waste Site Characterization (Cameron, 1991), may
provide assistance in selecting site and soil charac-
terization parameters and in identifying available field,
laboratory, and calculation or lookup methods for in-
dividual parameters.
This field guide is intended to assist in carrying out
three major types of activities in the field:
• Description of site and soil features based on
visual and tactile observation
• Field tests or measurements that involve rela-
tively simple procedures and equipment
• Methods for collecting undisturbed or minimally
disturbed samples for physical and microbiologi-
cal characterization in the laboratory
Collection of samples for chemical characterization
in the laboratory is not covered in detail in this guide, be-
cause it is assumed that this is defined in detail in the
Sampling and Quality Assurance Plans for the site.
However, general protocols for sample handling and
preparation and for sampling with a spade and scoop,
augers, or thin-walled tube samplers are contained in Ap-
pendices A.2 through A.4.
Specialized field procedures involving more com-
plicated equipment, such as for measuring unsaturated
hydraulic conductivity, are not covered in this field guide.
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Procedures involving such methods should be described
in the Sampling Plan.
1.3 Field Description of Soils
Multiple soil profile descriptions at a site can
provide a great deal of information that may be useful in
evaluating the variability of soil properties, and the direc-
tions and potential for transport of contaminants in the
subsurface. Detailed soil profile descriptions have not
been commonly used at contaminated sites. One purpose
of this field guide is to encourage greater use of this rela-
tively easy field method.
Table 1-1 summarizes the key features that should
be noted in detailed soil profile descriptions and identifies
the sections in this field guide that cover individual fea-
tures. Preparation of a complete, detailed soil profile
description requires the digging of a pit so that feature can
be observed laterally as well as vertically. Although this
method is time consuming, the ability to observe small-
scale lateral variations in soil features associated with in-
creased or reduced soil permeability, justifies, in most
instances, a limited number of such soil profile descrip-
tions at a site.
Where soils are not rocky, a thin-wall soil probe
can be used to prepare a moderately detailed soil profile
description in a sufficiently short time so that larger scale
variations in soil characteristics can be identified. Appen-
dix A.1 describes a general protocol for description of soil
cores. Table 1-1 recommends that all the features used in
preparing a pit soil profile description be observed. It
should be recognized, however, that the soil core may be
too small a sample of the subsurface to accurately
describe a number of features, such as transitions
between horizon boundaries, certain types of soil structure
(columnar, for example), pore and root distribution, and
genetic horizons (fragipans, for example). These features
are indicated with an asterisk in Table 1-1.
Preparation of an accurate, detailed soil profile
description requires training and experience, and such
descriptions are best done under the supervision of some-
one familiar with procedures developed by the Soil Con-
servation Service in the U.S. Department of Agriculture.
Field Methods, Equipment, and Documents
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Field Methods, Equipment, and Documents 4
KWXXttWX-KWW'KWM'W^
Table 1-1. Suggested Soil Parameters for Field Description
Parameter Section
in Guide
Horizons 3.1.1
USDA Texture 3.1.2
Color 3.1.3
Porosity 3.1.4
Zones of Increased Porosity/Permeability
Soil structure 3.1. 5a
Extrastructural cracks 3.1.5b
Roots 3.1.5c
Surface features 3.1. 5d
Sedimentary features 3.1.5e
Zones of Reduced Porosity/Permeability
Genetic horizons 3.1.6a
Consistency 3.1.6b
Root restricting layers 3.1 .6d
Compaction 3.1.6e
Moisture Condition 3.2.1
Water Table 3.2.2
Saturated Hydraulic Conductivity 3.2.4
Clay Minerals 3.3.7
Other Minerals 3.3.8
Odor 3.3.2
Soil
Profiles
R*
R
R
R*
R*
r
R*
R
R*
R*
R
R*
r
R
R
R"
r
r
r
Soil
Samples
R
R
R
r
r
r
r
R
R
r
R = Recommended for all situations.
r = Recommended where climatic, geologic, and soil
conditions make parameter significant.
* Soil pit may be required for accurate description of this
soil feature.
** Estimation of Ksat class based on other observable features.
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Soil samples for chemical characterization in the
laboratory should generally not double as samples for
detailed soil description, because exposure to the air
before placement in sample containers should be mini-
mized. However, abbreviated descriptions should be
made to identify the samples and possibly help in relating
sample results to other soil profile descriptions. Table 1 -1
recommends that, at a minimum, soil horizon (or depth in-
crements), color, texture, moisture condition, and relation-
ship to the water table be observed. The table also
identifies several other features (porosity, structure, and
roots) for which observations would be useful, if the nature
of the sample allows (soil core) and exposure to air is less
of a concern (heavy metals in aerated soil).
1.4 Field Sampling and Testing
A number of tests involving relatively simple proce-
dures and equipment can be used to measure or charac-
terize soil physical and chemical properties. Such tests
are generally not as accurate as laboratory tests but have
the advantage of being inexpensive and may be used for
preliminary screening or selection of samples for more ac-
curate laboratory testing.
Form 1-1 provides a checklist of soil engineering,
physical, and chemical parameters for which field tests are
described in this field guide. Special sampling procedures
for microbiological characterization are covered in Section
3.3.10.
Before going into the field, this checklist should be
used to identify the specific tests that appear to be of
value for the site of interest. This procedure will assist in
locating the appropriate section of the field guide where
specific procedures are described, and in identifying
equipment needs (see next section).
1.5 Field Equipment and Documents
Form 1-2 is a checklist of over 90 items that may
be required for field description, analysis, and sampling of
soils. Major categories covered in this checklist include (1)
documents, (2) protective equipment, (3) miscellaneous
equipment, (4) site surface characterization, (5) soil
description equipment/materials, (7) texture analysis and
sample preparation equipment, (8) sample, equipment,
Field Methods, Equipment, and Documents
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Field Methods, Equipment, and Documents
and waste containers and forms, and (9) field testing and
analysis. Form 1 -3 contains a checklist of around 20 items
related to quality assurance and quality control of the sam-
pling process, such as (1) QA/QC forms and samples, (2)
material required for sample preservation and transport,
and (3) decontamination equipment.
These checklists have two columns: the first is to
identify those items that are needed for the site in ques-
tion; the second column can be checked when the item
has been obtained and packed. Required items can be
identified by reviewing the site Soil Sampling Plan and
Quality Assurance Plan and the checklist of field tests
contained in this guide (Form 1 -1 ).
1 .6 Use of EPA's Environmental Systems
Monitoring Laboratory
EPA's Environmental Systems Monitoring
Laboratory is developing an Environmental Sampling Ex-
pert System (ESES) which ultimately will integrate a
Geographic Information System and Site Description Sys-
tem (including data quality objectives, quality assurance
and quality control, and site description) with a Knowledge
Frame Manager (for analysis, interpretation of data, and
report preparation) for contaminated sites.
The Guide to Site and Soil Description for Haz-
ardous Waste Site Characterization (Cameron, 1991)
provides the basis for the site and soil components for me-
tals in the ESES. Site and soil parameters (called Ob-
ject/Attributes in the ESES), are assigned "values" which
have significance for contaminant transport and fate.
Form 3-1 (Soil Profile and Related Information)
contains space to record observations related to all the
site and soil knowledge frames in EPA's ESES. Data on
this form can be coded on Forms 1-4 and 1-5 (Coding
Sheet for Use of ESES Site and Soil Knowledge Frames)
to aid in data interpretation using the ESES or Cameron
(1991). These forms also indicate the section in this guide
that covers description procedures and nomenclature.
Where standard SCS descriptive procedures do not readi-
ly allow assignment of a "value" for the ESES, definitions
used in the ESES are provided for use during field obser-
vations. Cameron (1991) provides additional definitions of
terms.
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Form 1-1. Checklist of Soil Physical and Chemical
Property Sampling and Field Test Procedures
Soil Physical Properties
Color ignition test (Section 3.1.3)
Extras!ructural crack tests (Section 3.1.5b)
Fragipan identification (Section 3.1.6a)
Cementation test (Section 3.1.66)
Bulk density (Section 3.1.6c)
Pocket penetrometer test (Section 3.1.6e)
Soil temperature regime characterization (Section 3.1.8)
Soil moisture (Section 3.2.1)
Water table estimation (Section 3.2.2)
Available water capacity (Section 3.2.3)
Saturated hydraulic conductivity class estimation
(Section 3.2.4)
Soil drainage class placement (Section 3.2.4)
Soil Engineering Properties
Unified (ASTM) texture (Section 3.1.7a)
Atterberg limits (Section 3.1.7b)
Shear strength (Section 3.1.7c)
Shrink-swell tests (Section 3.1.7d)
Corrosivity characterization (Section 3.1.7e)
Soil Chemical Properties
Organic matter ignition test (Section 3.3.1)
Cation exchange capacity/exchangeable acidity
(Section 3.3.3)
pH (Section 3.3.4)
Redox potential (Section 3.3.5)
Electrical conductivity (Section 3.3.6)
Clay minerals—nitrobenzene test (Section 3.3.7)
Calcium carbonate—HCI test (Section 3.3.8)
Soluble salts—chloride and sulfate (Section 3.3.8)
Gypsum acetone test (Section 3.3.8)
Iron oxides—ignition and streak tests (Section 3.3.8)
Manganese—streak and hydrogen peroxide tests
(Section 3.3.8)
Sampling for soil microbiota (Section 3.3.10)
Field Methods, Equipment, and Documents
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Field Methods, Equipment, and Documents
mmy&m&>&mzx»s»mim&xi»>&mi^M^fm&ms».
Form 1-2. Soil Description/Sampling Equipment and
Documents Checklist
Check first column to identify needed items. Check second
column when item has been obtained and packed prior to leav-
ing for the field.
Documents
Sampling plan
Quality assurance plan
Health and safety plan
Log books
Protective Equipment
Protective suits
Boots
Gloves (inner/outer)
Duct tape
Respirators, respirator cartridges, and/or dust
masks
Raingear and/or warm clothing
Insect repellent (should not contain chemicals that
will be target analytes or in matrix spikes)
Miscellaneous
Keys for access to site, graphite lubricant for locks
Folding table
Camera and film
Flashlight and extra batteries
Toolbox, including hacksaw
Calculator
Site Surface Characterization
Max/min thermometer
Humidity gage or sling psychrometer
Hand-held anemometer
4-ft staffs with flags or flagging (for wind direction
indicators)
Clinometer for slope measurement
6-ft rod and colored tape to mark eye level for
clinometer readings
(Continued)
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Form 1-2. (Continued)
Soil Description Equipment/Materials
Field notebook, pencils, ballpoints, and markers
Clipboard with cover
Microcassette recorder, spare microcassettes and
batteries (optional for notetaking)
Map of soil sampling locations
Soil profile and related information forms (Form
3-1)
Unified (ASTM) texture determination form (Form
3-2)
Other soil data collection forms:
Carpenters rule (for measuring horizon depth)
and/or steel tape
30-cm by 2-m plastic sheet for placing soil cores
for description
Munsell Soil Color book
Knife (for cleaning exposed soil surfaces)
Nails (for marking horizon boundaries)
10 power hand lens (surface features, mineral
identification, carbonate test)
Sand size and coarse fragment determination
scales
1/2 in. mesh (for estimating areal distribution of
features on excavated profile)
Tile probe (soil depth determination in rocky soil)
Stiff, 2-mm wire for crack depth measurement
Graded sand of uniform color for crack
characterization (excavation method)
Stereoscopic microscope (5 to 6 in. working
distance, 20 to 80 power)
Small high intensity 6v flexible lamp (for
illuminating microscope)
(Continued)
:::::::::::::::::*::W*:*y*ra^
Field Methods, Equipment, and Documents 9
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Field Methods, Equipment, and Documents 10
:*:•:•:%*:*:•:•:*:•:•:•:•:•:•:•:• ww
Form 1-2. (Continued)
Soil Sampling Equipment (specified in Sampling Plan)
Hand-held sampling devices
(Check all items that may be required at the site.)
Shovel/spade
Spoons
Scoops
Screw-type auger
Barrel/bucket auger (regular, sand, mud, stone,
planer, in situ soil recovery)
Thin-walled tube
Chisel rock breakers
Crescent wrenches, vice grips, pipe wrenches (for
changing drill rod length and sampling tips)
Weighted plastic mallet
Tube sampler cleaning tool
Power-driven sampling devices
(Check types planned for use at the site.)
Auger
Split spoon
Thin-walled tube samplers
Texture Analysis and Sample Preparation Equipment
Sieves (3 in., 1/2 in., No. 10, for characterizing
coarse fraction)
Hanging spring scale with canvas sling or pail (for
weighing coarse fragments)
No. 10 mesh stainless steel screens (for TOC and
semivolatile samples)
No. 10 mesh Teflon® screens (for metals samples)
Compositing bucket/mixing containers (stainless
steel, glass, Teflon®-lined suitable for all
contaminants; aluminum pans for any contaminant
except Al; plastic for metals analysis only)
1 -m square piece of suitable plastic, canvas, or
rubber sheeting (for sample preparation)
(Continued)
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Form 1-2. (Continued)
Sample, Equipment, and Waste Containers and Forms
Brown plastic trash bags for dirty equipment
White plastic trash bags for clean equipment
Ziplock type plastic bags for protecting equipment
that cannot be decontaminated (cameras,
notebooks, etc.)
Sample containers (sealed clean and labeled plus
20 percent)
Plastic bags for sample containers
Sample description/identification forms
Sample labels/tags
Soil moisture tins
Field Testing and Analysis
Photoionization detector (PID) or flame ionization
detector (FID)
Calibration gases for meters
Hydrogen gas for FID
Specialty gas meters (HCN, etc.)
Explosimeter
Scale/balance (0.1 gram accuracy) for weighing of
samples (moisture, bulk density, organic matter)
Infrared lamp, or small oven, and thermometer
scaled to at least 120°C (for drying samples for
moisture, bulk density, and organic matter tests)
Portable gas soldering torch and porcelain crucible
or small tin (not Al) with wire bracket or tongs (for
ignition tests)
Saran-ketone mixture (bulk density clod method)
or sand-measuring or rubber balloon apparatus
(bulk density excavation method)
pH measurement kit and standard solutions (spare
batteries, if necessary), and/or color dyes, pH test
strips
Glass or plastic stirring rod (pH test)
Small containers for mixing water and soil (pH,
specific conductance tests)
(Continued)
Field Methods, Equipment, and Documents 11
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Field Methods, Equipment, and Documents 12
X*x*x*x*:':'K*x*K*:*:'XW
Form 1-2. (Continued)
Field Testing and Analysis (Continued)
Conductivity meter and specific conductance
standards
Quart container of distilled deionized water in
squeeze bottle (for pH, texture, and carbonate
tests)
Common laboratory spatulas (for texture tests)
Porcelain spot plate (carbonate test, iron oxide,
manganese oxide scratch tests)
Clean glass rod (carbonate test)
10-percent HCI in plastic squeeze bottle
(carbonate test)
Solution of malachite green in nitrobenzene (for
clay minerals test)
Hydrogen peroxide (manganese test, organic
matter tests)
Test tubes or plastic vials and 5-percent silver
nitrate, and 5-percent barium chloride solutions
(chloride and sulfate tests)
Small stoppable bottle, filter paper, and acetone
(gypsum test)
Field sampling glove box and core paring tool (for
aseptic core samples for microbiological
analysis—see Section 3.3.10)
-------
Form 1-3. Soi! Sampling Quality Assurance/Quality Control
Checklist
Check first column to identify needed items. Check second
column when item has been obtained and packed prior to leav-
ing for the field.
Forms
_ _ List of sample locations where duplicates and
other QA samples are to be taken
_ _ Sample alteration form (Form 3-1 ), multiple copies
_ _ Field audit checklist (Form 3-2)
_ _ Soil sample corrective action form (Form 3-3)
QA Samples (check types specified in QA Plan)*
Double-Blind Samples
_ _ Field evaluation samples (FES)
_ _ Low level field evaluation samples (LLFES)
_ _ External laboratory evaluation samples (ELES)
_ _ Low level external laboratory evaluation samples
(LLELES)
_ _ Field matrix spike (FMS)
_ _ Field duplicate (FD)
_ _ Preparation split (PS)
Single-Blind Samples
_ _ Field rinsate blanks (FRB) — also called field
blanks, decontamination blanks, equipment
blanks, and dynamic blanks
_ _ Preparation rinsate blank (PRB) — also called
sample bank blanks
_ _ Trip blank (TB) — also called field blank
Sample Preservation and Transport
_ _ Chest or 6-pack cooler
_ _ Ice
_ _ Max/Min thermometer
_ _ Chain-of-custody forms and seals
_ _ Shipping forms
_ _ Analytical analysis request forms, if different from
chain-of-custody forms
(Continued)
Field Methods, Equipment, and Documents 13
-------
Field Methods, Equipment, and Documents 14
:*w*:*:o:-x-»:*:*:*:*:*:*:*xw^
Form 1-3. (Continued)
Decontamination
_ _ Decontamination vessel
_ _ Wash solution(s) — should be specified in
Sampling Plan.
_ _ Garden spray cans for wash fluids
_ _ Rinse solutions (acetone, deionized water)
_ Labels for containerized wastes (solid or liquid)
* See van Ee et al. (1 990) for more detailed discussion of these
types of samples.
-------
Form 1-4. Coding Sheet for ESES Site Knowledge Frames
Object/Attribute Source*
Nature of Heavy Test
Metal Pollutants results
(enter elements
concentrations —
see Table 3-1 in
Cameron [1991])
Climate/Weather Lookup
Macrofauna and 2.6
Mesofauna
Slope 2.2
Surface 2.3
Erosion/Erodibility
Surface Pollution 1.1
Situations
Surface Runoff 2.4
Vegetation 2.5
Wind Speed/Direction 2.1 .2
Value
Mobile/ Nonmobile/
Toxic Nontoxic
Humid
Temperate
Dry
Many
Common
Few
Steep (>1 2%)
Moderate (3-1 2%)
Flat (<3%)
Severe
Moderate
Slight to none
Large areas
Localized areas
Rapid (H, VH)
Medium (M)
Slow (L, VL)
Ponded (N)
Dense
Scattered/Sparse
Absent
Gale
Breezy
Calm to light
*Use observations recorded on Form 3-1 or refer to indicated
section number in this guide. For lookup methods, refer to
Appendix D in Cameron (1991).
Field Methods, Equipment, and Documents
15
-------
Field Methods, Equipment, and Documents
16
Form 1-5, Coding -Sheet for ESES Soil Knowledge Frames
Object/Attribute
Bulk Density (g/cc)
Cation Exchange
Capacity
(meq/100g soil)
Clay Minerals
Color
Compaction
Consistency
Corrosivity
Electrical Conductivity
(Salinity, mmhos/cm)
Fertility Potential
Source*
3.1. 6c
Lab
3.3.3
Lab
3.1.2
3.3.7
Lab
3.1.3
3.1.6e
3.1. 6b
3.1.7e
Lookup
3.3.6
Lab
3.3.9
Lab
Value
Low(<1.3)
. Medium (1.3-1. 6)
High(>1.6)
Low(<12)
Medium (12-20)
High (>20)
Abundant (>27%)
Mod/Slight(1-27%)
None/Neg. (<1%)
Dark
Red and Yellow
Brown
Gray/Whitish
Mottled
High
Moderate
Low/Slight
High
Moderate
Low/Weak
Cemented
High
Moderate
Low
Nonsaline (<2)
Slight (2-4)
Moderate (4-8)
Very (8-1 6)
Extremely (> 16)
High
Moderate
Low
(Continued)
-------
Form 1-5. (Continued)
Object/Attribute Source*
Horizons 3.1.1
Hydraulic 3.2.4
Conductivity
(micrometers/s)
Infiltration/ 3.2.5
Percolation (cm/hr)
Microbiota 3.3.10
Lab
Moisture 3.2.1
Conditions Lab
Odor 3.3.2
Organic Matter 3.3.1
Lab
Porosity 3.1.4
Reaction (p.H) 3.3.4
Value
Master Horizons
Transitional
Disturbed
Buried
High(>10)
Moderate (0.1 -10)
Low (0.01 -0.1)
Inhibited (<0.01)
High (>5)
Medium (1.5-5.0)
Low (0.1 5-1 .5)
Inhibited (<0.1 5)
Abundant
Common
Few
None
Wet
Moist
Dry
High
Mod/Slight
None
Abundant (>4%)
Moderate (2-4%)
Sparse (<2%)
Coarse (>5mm)
Medium (2-5mm)
Fine(0.5-2mm)
Very fine (<0.5rnm)
Acid (<6.6)
Neutral (6.6-7.3)
Alkaline (>7.3)
(Continued)
Field Methods, Equipment, and Documents
17
-------
Field Methods, Equipment, and Documents
18
w^^
Form 1-5. (Continued)
Object/Attribute
Source*
Value
Redox Potential
Roots
Structure Grades
Surface Features
Temperature
Temperature
Regimes
Texture Classes
3.3.5
3.1.5c
3.1.5a
3.1.5d
3.1.8
3.1.8
Lookup
3.1.2
High Oxidized
Intermediate
Highly Reduced
Many
Common
Few
Structureless
Weak
Moderate
Strong
Prominent
Distinct
Faint
High
Medium
Low
Pergelic
Cryic
Frigid-lsofrigid
Mesic-lsomesic
Thermic-lsothermic
Hyperthermic-
Isohyperthermic
Fragmental
Sandy
Silty
Loamy
Clayey
Organic soils
*Use observations recorded on Form 3-1 or refer to indicated
section number in this guide. For laboratory and lookup
methods, refer to Appendix D in Cameron (1991).
-------
Chapter 2
!06SSiSeiS®®iiSS8SittSttitStiiliit
Site Characteristics
This chapter covers a number of weather-related factors
that affect the ease or difficulty of soil description and
sampling in the field (Section 2.1) and other site surface
features at locations where soils are described or
sampled. These features include slope (Section 2.2), sur-
face erosion (Section 2.3), surface runoff (Section 2.4),
vegetation (Section 2.5), and macro- and mesofauna as-
sociated with the surface and subsurface (Section 2.6).
2.1 Climate and Weather
Climate exerts a profound influence on soil directly
through soil forming and weathering processes such as
precipitation, evapotranspiration, and temperature, and in-
directly by its influence on vegetation. Climate is a known
factor at a site that is usually evaluated by analysis of
meteorologic records from nearby weather stations, al-
though in some instances detailed monitoring of
meteorologic parameters such as precipitation, tempera-
ture, and wind may be required as a part of site charac-
terization and remediation. This guide does not cover
methods for systematic monitoring of climatic factors.
Weather refers to the state of the atmosphere at a
site during field investigation activities. Unusual weather
conditions are usually noted during the sampling and
description of soils. Weather usually doesn't become a
concern during field work unless conditions, such as rain
or snow, adversely affect the carrying out of field proce-
dures or create health and safety concerns for field per-
sonnel. The major weather parameters to be monitored
during field work include air temperature, wind speed and
direction, and humidity. The site health and safety officer
is primarily responsible for evaluating adverse weather
conditions and pacing field activities accordingly, but field
personnel should communicate their own feelings about
working under adverse weather conditions.
::::Wi^::::::::::::y:y::::::::ftW*::W:y:;:W:^
Site Characteristics 19
-------
Site Characteristics 20
2.1.1 Air Temperature
Air temperature is primarily a concern when it is at
one extreme or the other. Heat becomes a special con-
cern when protective clothing must be worn on site, be-
cause the impervious material used increases sweating
and the possibility of heat stress from dehydration. Ex-
treme cold makes sampling and notetaking difficult. Max-
min thermometers are relatively inexpensive and daily
extremes should be recorded along with periodic observa-
tions through the day, if appropriate. Wind speed (see
Section 2.1.2) should be monitored when working in the
winter to determine wind chill temperatures. Humidity (see
Section 2.1.3) should be monitored when the climate is
humid and temperatures are high.
2.1.2 Wind Speed and Direction
In winter, wind speed should be monitored to es-
timate wind chill temperature. Hand-held anemometers
can be used for this purpose. High winds create un-
favorable conditions for soil sampling, especially when soil
is dry, because of the possibility of contamination from
blowing surface soil and the mobilization of contaminated
subsoil that is brought to the surface. When it is breezy,
personnel should position themselves upwind during soil
sampling, and avoid sampling in locations where con-
taminated soil might blow into the exclusion area. Four-
foot staffs with flags or flagging placed around the site can
serve as wind direction indicators. Wind speed and direc-
tion should be recorded at each location where soils are
sampled.
EPA's ESES defines wind speed classes as follows:
Gale: >32 mph (>37 knots)
Breezy: 4 to 32 mph (3 to 37 knots)
Calm to light: <4 mph ( <3 knots)
2.1.3 Humidity
Relative humidity, the ratio of measured atmos-
pheric water vapor pressure to that which would prevail
under saturated conditions, is the most commonly used
measure of atmospheric moisture. For general field use,
relative humidity can be measured using a humidity gage,
but if very accurate measurements are desired, a sling
psychrometer should be used.
-------
Humidity is primarily a concern for field operations
when it is very high or very low. Very high humidity as-
sociated with high temperatures increases the danger of
heat stress in field personnel, especially when protective
clothing must be used on site. When sampling for soil
moisture when the humidity is low, special care should be
taken to minimize exposure of soil to the air to avoid
drying before the sample is sealed.
2.2 Slope
Slope is an important site feature that influences
the distribution of precipitation between the soil and sur-
face runoff, and the movement of soil water. Slope
gradient is usually measured as a percentage, but may be
measured in degrees. Both gradient and the length of the
slope (to the point where surface runoff loses its energy
and deposits suspended soil particles) are required for es-
timating erosion using the Universal Soil Loss Equation
(see Section 2.3 below). Slope shape and topographic
position influence the movement of water on the surface
and in the subsurface. Slope aspect affects the moisture
status of soil, with southern exposures usually drier than
northern exposures due to increased evapotranspiration.
Soil surveys prepared by the U.S. Soil Conserva-
tion Service (SCS) differentiate soil map units in upland
areas by the dominant soil series and a slope range (such
as 0 to 2 percent, 2 to 6 percent, 6 to 12 percent, etc.) that
is based on soil management considerations. Slope
classes are based on slope gradient limits as follows (Soil
Survey Staff, 1991):
Classes
Simple
Slopes
Nearly level
Gently sloping
Strongly sloping
Moderately steep
Steep
Very steep
Complex
Slopes
Nearly level
Undulating
Rolling
Hilly
Steep
Very steep
Slope Gradient
Limits (%)
Lower
0
1
4
10
20
>45
Upper
3
8
16
30
60
Site Characteristics
21
-------
Site Characteristics 22
Different SCS county soil surveys may specify dif-
ferent slope ranges for a slope class within the lower and
upper limits identified above.
The following slope features should be observed
when preparing a soil description:
Gradient (percent or degrees)—Measured using a
clinometer and a rod with a marking at the ob-
server's eye level. Siting through the clinometer up
or downslope to the marker on the rod allows a
direct reading in percent or degrees. Accurate
readings require that (1) the line of siting is perpen-
dicular to the contour of the slope, and (2) there is
no change in slope gradient over the distance the
siting is taken.
Length (if erosion potential is evaluated).
Shape—Convex, concave, or flat.
Topographic position—Summit, shoulder, back-
slope, footslope, toeslope, orfloodplain.
2.3 Surface Erosion and Erodibility
Field evaluation of surface erosion has two com-
ponents: (1) assessment of soil loss or deposition that has
occurred in the past, and (2) evaluation of the future
erosion potential.
In upland soils, the amount of erosion can be in-
ferred by comparing observed texture and color in the A
and B horizons (see Section 3.1.1 for definitions of
horizons) with a nearby undisturbed soil in a similar
topographic setting (if available), or with a soil profile
description prepared by the SCS for the soil series to
which the soil belongs. The thickness of the A horizon is
reduced in moderately eroded soils, and may show
mixing with the B horizon if the soil has been cultivated.
Rill erosion, the removal of soil through the cutting of
many small, but conspicuous channels, may be evident on
unvegetated soil. In severely eroded soils, most of the
topsoil is missing and gully erosion (channels that cannot
be obliterated by ordinary tillage) may be evident. Soils
with slight to no erosion have fully developed A horizons
and surface material showing little evidence of erosion.
-------
In depressional areas, the thickness of soil that has
accumulated as a result of accelerated erosion can be
measured by finding the top of the natural A horizon,
provided the eroded material can be differentiated by
color, texture, and other soil features. Surface con-
taminated soil preferentially concentrates in such areas,
and special sampling may be desirable.
Use of the Universal Soil Loss Equation (USLE) or
its revised version (RUSLE) to estimate erosion potential
from a site requires the following field observations: (1)
slope gradient and length (see Section 2.2 above) and (2)
vegetation (Section 2.5). The soil credibility factor (K) can
usually be obtained from SCS soil series interpretation
sheets. If classification of a soil is uncertain, the K factor
can be estimated using soil erodibility nomographs (SCS,
1983). The following soil properties must be described or
estimated to use these soil nomographs: (1) percent silt
plus very fine sand, (2) percent sand (0.10 to 2.0 mm), (3)
percent organic matter (see Section 3.3.1), (4) soil struc-
ture (see Section 3.1.5a), and (5) permeability class (see
Section 3.2.4).
EPA's ESES defines soil erodibility classes based
on estimated annual soil loss, using the USLE or RUSLE,
as follows:
Severe: >10 metric tons/hectare.
Moderate: 2.5 to 10 metric tons/hectare.
Slight: <2.5 metric tons/hectare.
2.4 Surface Runoff
Surface runoff potential is important for evaluating
the potential for transport of contaminants at the soil sur-
face to surface streams or water bodies.
SCS defines six runoff classes that can be used for
qualitative comparison of runoff from different locations at
a site (See Table 2-1). Placement requires measurement
of the slope gradient (see Section 2.2) and measurement
or estimation of the saturated hydraulic conductivity (see
Section 3.2.4).
Computation of runoff by SCS's Curve Number
Method requires placement of soils in hydrologic groups
Site Characteristics 23
-------
Site Characteristics 24
based on saturated hydraulic conductivity (Ksat—see Sec-
tion 3.2.4) and water table characteristics (Section 3.2.2).
If the hydrologic class of the soil of interest is not known, it
can be determined using Table 2-2.
2.5 Vegetation
Vegetation at a site serves as an indicator of site
history and site productivity and is a major determinant in
erosion potential at a site (see Section 2.3).
Features observed and noted should include the
nature, kind, extent, and distribution of plants and plant
cover. The charts in Figure 3-3 (Section 3.1.2) for estimat-
ing areal percentages of coarse fragments and mottles
also can be used to estimate amount of vegetative cover.
Vogel (1987) describes more precise methods for measur-
ing vegetation cover such as the point-quadrant method,
rated microplots, and line intercepts.
Stunted vegetation or discolored leaves may be an
indication of toxic effects from contaminants in the soil. In
heavy metal contaminated sites, sampling of vegetation
along with soil may be desirable to assess exposure
through bioaccumulation.
EPA's ESES defines qualitative vegetation classes
as follows:
Dense: Site completely covered with vegetation of
predominant forms or varying composition and
species, usually with slow temporal variability.
Scattered to sparse: Plant cover, aerial, or soil
surface vegetation, is intermittent or infrequent at
site.
Absent: No visible macrovegetation can be ob-
served, but some scattered soil vegetation cover
(e.g., algal-lichen crusts or mosses) may be
evident.
-------
Table 2-1. Index Surface Runoff Classes
Slope
Gradient
(%)
Concave***
<1
1-5
5-10
10-20
>20
Runoff Classes*
Ksat Class"
VH
N
N
N
VL
VL
L
H
N
N
VL
L
L
M
MH
N
N
L
M
M
H
ML
N
L
M
H
H
VH
L
N
M
H
VH
VH
VH
VL
N
H
VH
VH
VH
VH
* Abbreviations: Negligible-N; very low-VL; low-L; medium-M;
high-H; and very high-VH. These classes are relative and not
quantitative.
** See Section 3.2.4 for definitions. Assumes that the lowest
value for the soil occurs at <0.5 m. If the lowest value occurs
at 0.5 to 1 m, reduce runoff by one class. If it occurs at >1 m,
then use the lowest saturated hydraulic conductivity <1 m. VL
Ksat is assumed for soils with seasonal shallow or very shal-
low free water.
*** Areas from which no or very little water escapes by flow
over the ground surface.
Table 2-2. Criteria for Placement of Hydrologic Soil Groups
Criteria*
Soil
Group*
A
B
C
D
Ksat
>55
5.5 to 55
.55 to 5.5
<.55
Free Water Depth/Duration
DV**(>1.5m)
DorDV(>1 m)
>S (>0.5 cm)
S or SV (0 to 0.5 m);
T through P
* The criteria are guidelines only. They are based on the as-
sumption that the minimum saturated hydraulic conductivity
occurs within the uppermost 0.5 m. If the minimum occurs
between 0.5 and 1 m, then Ksat for the purpose of placement
is increased one class. If the minimum occurs below 1 m,
then the value for the soil is based on values above 1 m
using the rules previously given.
** See Section 3.2.2 for meaning of abbreviations.
Site Characteristics 25
-------
Site Characteristics 26
2,6 Macro- and Mesofauna
Soil macrofauna, such as burrowing animals,
earthworms, and larger insects that can be measured in
centimeters, and mesofauna, such as smaller mollusks
and arthropods, affect soil profiles by mixing, changing,
and moving soil material. The activities of soil macro- and
mesofauna tend to increase the secondary permeability of
soil horizons and thus provide preferential paths for sub-
surface migrations of contaminants.
Surface features that animals produce include ter-
mite mounds, ant hills, heaps of excavated earth beside
burrows, the openings of burrows, paths, feeding grounds,
and earthworm or other castings.
These features can be described in terms of (1)
number of structures per unit area, (2) proportionate area
occupied, and (3) volume of aboveground structures.
Krotovinas, irregular tubular streaks of soil material with
contrasting color or texture, resulting from filling of tunnels
made by burrowing animals, may be observed in soil pits.
Where soils are contaminated with heavy metals,
collection of soil macro- or mesofauna for chemical
analysis may provide evidence of bioaccumulation for ex-
posure assessment, provided that similar species on near-
by uncontaminated soils with similar characteristics can be
obtained for comparison.
Macro- and mesofauna are described for EPA's
ESES by species and abundance per unit area as follows:
Class Number/m2
Macrofauna
Many >10
Common 5-10
Few 1-5
None 0
Mesofauna
Many >100,000
Common 100-100,000
Few 10-100
None <10
-------
Chapter 3
Field Description
and
Analysis of Soils
This chapter presents field test and soil description pro-
cedures that can be done visually or with simple field
equipment. Appendix D of Cameron (1991) identifies ref-
erences where more detailed information can be found
about more complex field procedures for measuring
specific soil parameters.
For nonengineering applications, the soil taxonomy
of the U.S. Soil Conservation Service is the most widely
used system for describing and classifying soils. The basic
reference on this system is Soil Taxonomy, Agricultural
Handbook 436 (Soil Survey Staff, 1975). Revisions and
amendments are periodically published in looseleaf form
as Soil Taxonomy Notes. The most recent edition of the
pocket-sized Keys to Soil Taxonomy (Soil Survey Staff,
1990) is the best concise reference source on classifica-
tion of soils, and is recommended for use in the field (price
and ordering information are given in the reference sec-
tion).
Unfortunately, the most up-to-date reference for
current SCS soil description procedures, a major revision
of Agricultural Handbook 18, Soil Survey Manual (Soil
Survey Staff, 1991), is not yet readily available. Most of
the soil description procedures in this guide are taken from
the latest version of the new manual. Other important ref-
erences for field investigation procedures for noncon-
taminant parameters are published by SCS (1971 and
1984). Procedures from the geologic literature for descrip-
tion of unconsolidated material below the weathering zone
are also included in this chapter.
Field Description and Analysis of Soils 27
-------
Field Description and Analysis of Soils 28
3.1 Soil Physical Parameters
A number of soil physical parameters such as
coarse fragments, pores, mottled colors, roots, lateral fea-
tures, and mineral concentrations require area measure-
ments on the ground surface or the wall of a pit for
conversion to volume or weight percentages. Section
3.1.2 includes charts for estimating proportions of a fea-
ture at the surface, but if more accurate measurements
are desired, traverses on an arbitrary grid can be used.
Coarse screening such as hardware cloth or rat
wire with a 1/2-inch mesh makes a convenient and
durable grid for small and medium objects as large as 2 to
4 inches (5 to 10 cm). A screen 1 foot square is suitable
for most situations. Marking every fifth, tenth, or twentieth
wire in each direction, or at intersections, with paint makes
counting easier. When the screen is tacked over the area
to be measured, a small wire pointer pushed into the soil
at the intersection of each wire allows the most accurate
counting of features in the grid. SCS (1971, Section I2.7)
provides additional guidance on making linear and volume
measurements.
Form 3-1 provides a sample form for description of
a soil profile. This form follows the sequence of features
for description of soil horizons in this chapter. Standard
forms used by SCS and coding sheets for computer
programs, which" automatically prepare narrative soil
profile descriptions, can also be used.
A dug pit that provides a lateral view of soil
horizons is best for accurate and detailed soil profile
description. Thin-walled tube samplers are the next best
alternative. Appendix A.1 outlines procedures for soil
descriptions using tube samplers and augers. Com-
prehensive descriptions using one or two pits, along with
less detailed tube/auger sampler descriptions at each
sampling site, would probably provide the maximum
amount of useful data.
-------
Form 3-1. Soil Profile and Related Information
Soil Type or Designation
Date ID No.
Described by
Location
Elevation
Wind Speed/Direction (2.1.1) _
Other Weather Conditions (2.1)
Parent Material
Topographic Position (2.2)
Slope Gradient Slope Length
Slope Shape Slope Aspect
Erosion (2.3)
Surface Runoff Class (2.4)
Vegetation (2.5)
Macro- and Mesofauna (2.6)_
Engineering Properties (3.1.7)
USCS Texture
Shear Strength Corrosivity_
Soil Temperature/Regime (3.1.8)
Water Table (3.3.3)
Depth (Max/Min)
Thickness, if Perched
Duration
Drainage Class (3.2.4)
Infiltration (3.2.5)
Redox Potential (3.3.5)
Electrical Conductivity (3.3.6)
Fertility Potential (3.3.9)
Soil Classification
Additional Notes
(Continued)
^
Field Description and Analysis of Soils 29
-------
Field Description and Analysis of Soils 30
x>HwXw:vX*:vM-:*:w-X':w
Form 3-1. (Continued)
Horizon (3.1.1)*
Depth
Boundary
Texture (3.1.2)
Fines (<2 mm)
>2 mm %
>2 mm description
Color (3.1.3)
Moist
Dry
Mottles (3.1.3)
Color
Description
Pores (3.1.4)
Structure (3.1.5a)
Roots(3.1.5c)
Surface Features
(3.1.5d)
Sedimentary Features
(3.1.5e)
Consistency (3.1.6b)
Moist/Dry
Cementation
Bulk Density (3.1.6c)
Compaction (3.1.6e)
Water State (3.2.1)
AWC (3.2.3)
Ksat (3.2.4)
OM (3.3.1)
Odor (3.3.2)
CEC (3.3.3)
pH (3.3.4)
Clay Minerals (3.3.7)
Carbonates (3.3.8)
Other Minerals (3.3.8)
Microbiota(3.3.10)
-------
3. 1. 1 Soil Horizons
Table 3-1 provides a key to SCS's 1981 system for
designating master horizons, layers, and transitional
horizons, along with the lower case letters that are used
for subordinate distinctions within horizons. If an SCS soil
survey of the site is available, the soil series descriptions
should be reviewed for a general idea of the types of
horizons likely to be encountered. SCS soil surveys pub-
lished prior to around 1984 contain soil profile descriptions
using the 1962 system. Table 3-2 compares the 1962 and
1981 systems and provides approximate equivalencies
where nomenclature has changed.
In glaciated areas, it may be useful to make more
precise designations for the C horizon. Table 3-3 shows
subdivisions and diagnostic characteristics of four types of
C horizons recognized by the Illinois State Geological Sur-
vey. If this notation is used in the description, it should be
clearly noted on the field sheet.
Key features to record are the depth and charac-
teristics of the boundary between horizons. The following nota-
tion can be used to describe horizon boundaries or contacts:
Distinctness
a — abrupt (<2 cm)
c — clear (2-5 cm)
g — gradual (5-1 5 cm)
d — diffuse (>5 cm)
Topography
s — smooth (nearly a plain)
c — clear (pockets with width > depth)
i — irregular (pockets with depth > width)
b — broken (discontinuous)
A disturbed soil has been truncated or manipulated
to the extent that its principle pedogenic characteristics have
been severely altered or can no longer be recognized.
A buried soil, or paleosol, is covered by an alluvial,
loessial, or other depositional surface mantle of more
recent material, and usually lies below the weathering
profile of the soil at the land surface. As noted in Section
3.1 .5, buried soils may have high secondary porosity com-
pared to materials above and below it, forming a potential
zone for preferential movement of contaminants.
:::::::^^^ .. .. ..
Field Description and Analysis of Soils 31
-------
Field Description and Analysis of Soils 32
s*:*:*:*:*:*:*^*:*^
Table 3-1. Definitions and Designation Nomenclature for
USDA Soil Horizons and Layers (Adapted from SSSA, 1987)
Master Horizons and Layers
O Horizons—Layers dominated by organic material, except lim-
nic layers that are organic.
A Horizons—Mineral horizons that formed at the surface or
below an O horizon and (1) are characterized by an ac-
cumulation of humified organic matter intimately mixed with
the mineral fraction and not dominated by properties charac-
teristic of E or B horizons; or (2) have properties resulting
from cultivation, pasturing, or similar kinds of disturbance.
E Horizons—Mineral horizons in which the main feature is loss
of silicate clay, iron, aluminum, or some combination of
these, leaving a concentration of sand and silt particles of
quartz or other resistant materials.
B Horizons—Horizons that formed below an A, E, or O horizon
and are dominated by (1) carbonates, gypsum, or silica,
alone or in combination; (2) evidence of removal of car-
bonates; (3) concentrations of sesquioxides; (4) alterations
that form silicate clay; (5) formation of granular, blocky, or
prismatic structure; or (6) a combination of these.
C Horizons—Horizons or layers, excluding hard bedrock, that
are little affected by pedogenic processes and lack properties
of O, A, E, or B horizons. Most are mineral layers, but limnic
layers, whether organic or inorganic are included.
R Layers—Hard bedrock including granite, basalt, quartzite, and
indurated limestone or sandstone that is sufficiently coherent
to make hand digging impractical.
Transitional Horizons
Two kinds of transitional horizons occur. In one, the properties
of an overlying or underlying horizon are superimposed on
properties of the other horizon throughout the transition zone
(i.e., AB, BC, etc.). In the other, distinct parts that are charac-
teristic of one master horizon are recognizable and enclose
parts characteristic of a second recognizable master horizon
(i.e., E/B, B/E, and B/C).
Alphabetical Designation of Horizons
Capital letters designate master horizons (see definitions above).
Lowercase letters are used as suffixes to indicate specific char-
acteristics of the master horizon (see definitions below). The
lowercase letter immediately follows the capital letter
designation.
(Continued)
-------
Table 3-1. (Continued)
Numeric Designation of Horizons
Arabic numerals are used as (1) suffixes to indicate vertical sub-
divisions within a horizon and (2) prefixes to indicate discon-
tinuities.
Prime Symbol
The prime symbol (') is used to identify the lower of two horizons
having identical letter designations that are separated by a
horizon of a different kind. If three horizons have identical
designations, a double prime (") is used to indicate the
lowest.
Subordinate Distinctions within Horizons and Layers
a — Highly decomposed organic material where rubbed fiber
content averages <1 /6 of the volume.
b — Identifiable buried genetic horizons in a mineral soil.
c — Concretions or hard nonconcretionary nodules of iron,
aluminum, manganese, or titanium cement.
e — Organic material of intermediate decomposition in which
rubbed fiber content is 1/6 to 2/5 of the volume.
f — Frozen soil in which the horizon or layer contains
permanent ice.
g — Strong gleying in which iron has been reduced and
removed during soil formation or in which iron has been
preserved in a reduced state because of saturation with
stagnant water.
h — Illuvial accumulation of organic matter in the form of
amorphous, dispersible organic matter-sesquioxide
complexes, where sesquioxides are in very small quantities
and the value and chroma of the horizons are <3.
i — Slightly decomposed organic material in which rubbed fiber
content is more than about 2/5 of the volume.
k — Accumulation of pedogenic carbonates, commonly calcium
carbonate.
m — Continuous or nearly continuous cementation or induration
of the soil matrix by carbonates (km), silica (qm), iron (sm),
gypsum (ym), carbonates and silica (kqm), or salts more
soluble than gypsum (zm).
n — Accumulation of sodium on the exchange complex sufficient
to yield a morphological appearance of a natric horizon.
(Continued)
Field Description and Analysis of Soils 33
-------
Field Description and Analysis of Soils 34
ti$#H8^^
Table 3-1. (Continued)
o — Residual accumulation of sesquioxides.
p — Plowing or other disturbance of the surface layers by
cultivation, pasturing, or similar uses.
q — Accumulation of secondary silica.
r — Weathered or soft bedrock including saprolite; partly
consolidated soft sandstone, siltstone, or shale; or dense till
that roots penetrate only along joint planes and which is
sufficiently incoherent to permit hand digging with a spade.
s — Illuvial accumulation of sesquioxides and organic matter in
the form of illuvial, amorphous dispersible organic matter-
sesquioxide complexes, if both organic matter and
sesquioxide components are significant and the value and
chroma of the horizon are >3.
t — Accumulation of silicate clay that either has formed in the
horizon and is subsequently translocated or has been
moved into it by illuviation.
v — Plinthite which is composed of iron-rich, humus-poor,
reddish material that is firm or very firm when moist and that
hardens irreversibly when exposed to the atmosphere
under repeated wetting and drying.
w — Development of color or structure in a horizon but with little
or no apparent illuvial accumulation of materials.
x — Fragic or f ragipan characteristics that result in genetically
developed firmness, brittleness, or high bulk density.
y — Accumulation of gypsum.
z — Accumulation of salts more soluble than gypsum.
-------
Table 3-2. Comparison of the 1962 and 1981 USDA Soil
Horizon Designation Systems
Alphabetical Designation of Horizons
Capital letters designate master horizons in both systems, but
there are some changes in specific letter designations (see
below).
Lowercase letters are used as suffixes to indicate specific char-
acteristics of the master horizon in both systems, but there
are some changes in specific letter designations (see below).
In the 1981 system, the lowercase letter always immediately
follows the capital letter designation.
Numeric Designation of Horizons
1962 System: Arabic numerals used as suffixes to (1) indicate
kind of O, A, or B horizon, and (2) indicate vertical sub-
divisions of a horizon; Roman numerals used as prefixes to
indicate lithologic discontinuities.
1981 System: Arabic numerals used as suffixes to indicate verti-
cal subdivisions within a horizon and as prefixes to indicate
discontinuities. Their use to indicate kind of O, A, or B
horizon has been eliminated.
Prime Symbol
1962 System: The prime used to identify the lower sequum of a
soil having two sequa (horizon sequences), although not for
a buried soil.
1981 System: The prime used to identify the lower of two
horizons having identical letter designations that are
separated by a horizon of a different kind. If three horizons
have identical designations, a double prime is used on the
lowest.
(Continued)
Field Description and Analysis of Soils 35
-------
Field Description and Analysis of Soils ......... ................
K.«SK.^
Table 3-2. (Continued)
Comparisons of Horizon Designations (see Table 3-1 for
definitions)
Master Horizons
Distinctions
1962
0
O1
O2
A
A1
A2
A3
AB
A&B
AC
B
B1
B&A
B2
B3
C
R
IIB23t
1981
O
Oi.Oe
Oa.Oe
A
A
E
ABorEB
—
E/B
AC
B
BAorBE
B/E
BorBw
BC or CB
C
R
2B13
Subordinate Horizon
1962
—
b
en
—
f
g
h
—
ca
m
sa
—
P
si
r
ir
t
—
—
X
cs
sa
1981
a
b
c
e
f
g
h
i
k
m
n
0
P
q
r
s
t
V
w
X
y
z
Source: Adapted from Guthrie and Witty (1982).
-------
Table 3-3. Subdivisions of the C Horizon Used in Illinois
Horizon Mineralogy Carbonates Color
Structure
C1
Strongly
altered
Leached
Uniform,
mottled
or
stained
C2
Altered
Unleached Uniform,
mottled,
or
stained
C3
C4
Partly Unleached Uniform;
altered rare
stained
Unaltered Unleached Uniform
Some soil
structure, peds
with clay films;
structure of
parent material—
blocky; layered,
or massive-
dominant; often
porous
Less soil,
structure, clay
films along
joints; structure
of parent
material—blocky;
layered, or
massive—
dominant;
often porous
Massive, layered,
or very large
blocky;
conchoidal
fractures; dense
Massive or
layered,
conchoidal
fractures; dense
Source: Follmer et al. (1979).
Field Description and Analysis of Soils
37
-------
Field Description and Analysis of Soils 38
•.-• v1.- v-. v*-1 •" -,f f. •:•• •: •" '
3.1.2 Soil Texture Classes
Soil texture, the relative proportions of silt-, sand-,
and clay-sized particles (also called particle-size distribu-
tion), is an important property from which many other soil
parameters can be estimated or inferred. This section
focuses on the USDA soil texture classification system.
Many other classification systems have been developed,
but of these, only the ASTM (Unified) system, which is
oriented toward soil engineering applications, is covered in
this field guide (see Section 3.1 .la).
Figure 3-1 shows the USDA soil texture triangle.
Classification is based on the fine fraction (less than 2
mm), with modifiers applied where coarse fragments are
more then 15 percent by volume. For example, a sample
that plots on the texture triangle as a sand, contains 40
percent rock fragments, which are mostly around 30 mm in
diameter. Using Table 3-4, the adjective modifier for 35 to
60 percent coarse fragments is the dominant rock plus the
word "very." The SCS adjective for coarse fragments
around 30 mm is gravelly or coarse gravelly. Thus, the full
texture description would be "very coarse gravelly sand."
The noun used to describe the coarse fragments is peb-
bles or coarse pebbles. Table 3-4 also shows simplified
descriptors for the >2 mm fraction based on the Wentworth
scale, which is more commonly used by geologists.
Sandy soil classes are often divided into subclass-
es according to the coarseness of the sand grains. Figure
3-2 shows the criteria for subclasses of sandy soils. Table
3-4 summarizes abbreviations and designations for record-
ing USDA soil texture in the field. Figure 3-3 provides
charts for estimating percentages of coarse fragments in a
soil horizon. Field determinations based on estimated per-
centages of clay and sand should be verified by laboratory
analysis of samples.
The following general groupings of texture classes
are sometimes used (see Table 3-4 for abbreviations):
Sandy (light or coarse)—s, Is
Silty (medium)—si, sil, sicl
Loamy (medium)—si, I, cl, scl (sil, si, sicl may be
included in this category)
Clayey (heavy or fine)—sc, sic, c
-------
100
40 50 60
PERCENT SAND
80
90 100
Using Materials Less Than 2.0 mm in Size. If
approximately 20% or more of the soil material is
larger than 2.0 mm, the texture term includes a modifier.
Example: gravelly sandy loam.
Example of Use: A soil material with 35% clay, 30% silt,
and 35% sand is a clay loam.
Figure 3-1. USDA soil texture triangle.
ffiiSSBiKiMHSB^^
Field Description and Analysis of Soils 39
-------
Field Description and Analysis of Soils 40
Table 3-4, Abbreviations and Designations for USDA Soi!
Texture Classes (including coarse fraction)
<2 mm Fraction >2 mm Fraction (SCS)
(See texture triangla, Adjective modifier
Figure 3-1 ) (see text explanation)
s — sand
Is — loamy sand
si — sandy loam
I — loam
si — silt
sil — silt loam
cl — clay loam
sicl — silly clay
loam
sc — sandy clay
sic — silty clay
c — clay
<15% none
<15-35% dominant rock
35-60% dominant rock + very
>60% (>5% fines) dominant
rock + extremely
>60% (<5% fines) dominant
rock adjective
Other Descriptive Features
of >2 mm fraction
Percent
Roundness
Mineralogy/rock type
Sorting
Rock Descriptors for >2 mm Fraction (SCS)
Shape/Size
rounded, subrounded,
angular, or irregular
Adjective/Noun (diameter, mm)
g — gravelly/pebbles 2-76
fg — fine gravelly/fine pebbles 2-5
mg — medium gravelly/medium pebbles 5-20
eg — coarse gravelly/coarse pebbles 20-76
k — cobbly/cobbles 76-250
st — stony/stones 250-600
b — bouldery/boulders >600
Flat (long, mm)
st — stony/stones 280-600
b — bouldery/boulders >600
ch — channery/channers 2-150
fig — flaggy/flagstones 150-380
(Continued)
-------
Table 3-4. (Continued)
Simplified Descriptors for >2 mm Fraction (IDEM)
gn —
pb -
fpb —
cpb —
cb —
b —
granules
pebbles
fine pebbles
coarse pebbles
cobbles
boulders
2-4
4-64
4-16
16-64
64-256
>256
Source: Soil Survey Staff (1991) and IDEM (1988).
The USDA soil taxonomy defines particle-size
classes for differentiation of the soils at the family level
(Soil Survey Staff 1975,1990) as described below:
Fragmental—Stones, cobbles, gravel, and very
coarse sand particles with too little fine earth to fill
some of the interstices larger than 1 mm in
diameter.
Skeletal—Rock fragments make up 35 percent or
more by volume. The dominant fine earth fraction
(sandy, loamy, or clayey) is used as a modifier.
Sandy—Texture of fine earth is sand or loamy
sand with <50 percent very fine sand; <35 percent
clay; <35 percent rocks.
Loamy—Texture of fine earth is very fine sand or
finer; <35 percent clay; <35 percent rocks. Sub-
divisions include coarse-loamy, fine-loamy, coarse-
silty, and fine-silty.
Clayey—Texture of fine earth is >35 percent clay;
<35 percent rocks. Subdivisions include fine and
very fine.
3.1.3 Soil Color
Soil color is described using Munsell Soil Color
charts (available from Munsell Color Company, 2441 N.
Calvert St., Baltimore, MD 21218). Color is usually a good
indicator of the redox status (see Section 3.3.5) of a
horizon (uniform high chroma colors indicate oxidizing con-
ditions; uniform low chroma colors usually indicate reduc-
ing conditions; mixed chromas indicate variable
Field Description and Analysis of Soils 41
-------
Field Description and Analysis of Soils
42
Basic
soil class
«
?
<3
Loamy Sands
Sandy Loams
Subclass
Coarse
sand
Sand
Fine
sand
Very fine
sand
Loamy
coarse
sand
Loamy
sand
Loamy
fine sand
Loamy
very fine
sand
Coarse
sandy
loam
Sandy
loam
Fine
sandy
oam
Very tine
sandy
oam
Soil separates
Very
coarse
sand, 2.0-
1.0 mm.
Coarse
sand, 1.0-
0.5 mm.
25% or more
Medium
sand, 0.5-
0.25 mm.
Less
than 50%
25% or more
L
ass than 25
25% or more
-or-
%
Less
than 50%
25% or more
L(
)ssthan25
25% or more
3
Less
than 25%
Betw
Le
0% or mon
-or-
een 15 and
ss than 15
-or-
%
Less
than 50%
»
-ar
30%
-or-
/„
Fine
sand,
0.25-
0.1 mm.
Less
than 50%
Less
than 50%
50% or
more
Less
than 50%
Less
than 50%
50% or
more
Less
than 50%
d-
Less
than 30%
30% or
more
More th
Very fine
sand, 0.1-
0.05 mm.
Less
than 50%
Less
than 50%
Less
than 50%
50% or
more
Less
than 50%
Less
than 50%
Less
than 50%
50% or
more
Less
than 50%
Less
than 30%
Less
than 30%
30% or
more
an 40%
"Half of fine sand and very fine sand must be very fine sand.
Figure 3-2. Percentage of sand sizes in subclasses of
sand, loamy sand, and sandy loam basic texture classes
(Source: Portland Cement Association, 1973).
-------
1%
5%
15%
20%
25%
?.«
30%
40%
50%
Figure 3-3. Charts for estimating proportions of coarse
fragments and mottles (each fourth of any one square has
the same amount of black).
:*s*:*:*:*K*:itt^
Field Description and Analysis of Soils 43
-------
Field Description and Analysis of Soils 44
saturation). In addition, low chroma, low value colors are
often indicative of high organic matter content.
Dark colors have low value (generally <3) and low
chroma (generally <2). Red colors generally have hues of
10YR or 2.SYR, and values and chromas >3. Yellow
colors generally have values and chromas >6 and hues of
7.5YR, 10YR, or 2.5Y. Brown colors typically have values
from 3 to 6, chroma from 3 to 5, and hues of 7.5YR or
10YR. Gray or whitish colors may be of any hue with
chromas <2 and values generally >3. The Munsell Soil
Color charts provide precise descriptors for any soil color
reading.
The following data should be recorded in field
description of color:
Color name.
Color notation (chroma, hue, value).
Water state (moistor dry).
Physical state (broken through ped is the stand-
ard state. Others are rubbed between fingers
(moist), or crushed/crushed and smoothed (dry)).
Soil mottling is usually an indication of variable
saturation, and is described according to abun-
dance, size, and color contrast. Figure 3-3
provides charts that may help in estimating mottle
abundance, and Figure 3-4 provides guidance in
identifying contrast.
Abbreviations, descriptors, and criteria for descrip-
tion of mottles are:
Abundance
f — few(<2%)
c — common (2-20%)
m — many(>20%)
Size
1 — fine (<5 mm)
2 — medium (5-15 mm)
3 — coarse (> 15 mm)
Contrast (see Figure 3-4)
f — faint (1 or 2 units H,C,V)
d — distinct (2-4 units H,C,V)
p — prominent (4-5 units H,C,V)
-------
CONTRAST OF MOTTLES
For Use with Munseil Color Chart
1 23456
Change in Chroma
FAINT-Record as Faint Where Similar, but
Low Value or Chroma.
CHART DIRECTIONS:
A. Select Change in HUE (None Ref. to Same Page).
B. Record Greatest of VALUE or CHROMA at
HUE Line Intercept (Faint, Distinct, or Prominent).
Figure 3-4. Guide for designation of mottle contrast.
Field Description and Analysis of Soils
45
-------
Field Description and Analysis of Soils 46
*x^^
Shape (spots, streaks, bands, tongues, tubes)
Location (inped, exped)
Boundaries (sharp — like a knife edge; clear-
colors grade over <2 mm; diffuse — colors grade
over >2 mm)
Color Ignition Test
An ignition test using 2 or 3 grams of soil can
provide useful information for interpretation of natural soil
colors. The equipment and procedures described in Sec-
tion 3.3.1 for organic matter should be used, except that
weighing of the samples is not required. The following
provides some guidance for interpreting colors:
Organic matter contributes black, brown, reddish
(spodic horizons), and grayish colors. It burns away, leav-
ing a whitish residue if it is the only colored material.
Minerals such as quartz, which make up the bulk of
sand and silt-sized particles, are mostly colorless or pale
colored to gray. These particles will not change color with
ignition. Mineral grains may be cemented with lime or
silica or stained with iron oxide, especially in dry regions.
SCS (1971, Section 17.1) describes procedures for clean-
ing mineral surfaces of cement and stains.
Iron oxides are red, brown, or yellow. If browns
and yellows become redder and brighter with ignition,
highly hydrated iron oxide (goethite) is present.
Ferrous (reduced) iron is indicated by gray, blue,
or green colors, and turns red when ignited to form
hematite.
Manganese oxides form black and purple bodies
and effervesce vigorously in a 5 percent solution of
hydrogen peroxide (See Section 3.3.8). Dark reddish
brown and dark brown surface soils in the southeastern
United States usually contain enough manganese oxides
to give a positive reaction to peroxide.
3.1.4 Soil Porosity
Laboratory analysis is required for accurate deter-
mination of soil porosity, but field description of soil pores
can provide useful qualitative data for estimating per-
meability and characterization of soil variability at a site.
Johnson et al. (1960) provides more detailed guidance on
classification and description of soil pores.
-------
Platy, Granular, or
Crumb Structure
Roots
Pores
Very Fine
(less than 1 mm diameter
vf
vf
Fine
(1-2 mm diameter)
Medium
2-5 mm diameter)
•
:
•
•
m ^k m
•
Coarse
(5-10 mm diameter)
Very Coarse
(more than 10 mm diameter)
Figure 3-5. Charts for estimating pore and root size.
Field Description and Analysis of Soils 47
-------
Field Description and Analysis of Soils 48
SCS describes pores according to (1) abundance,
(2) size, (3) distribution within the horizon, and (4) type.
Figure 3-5 can be used to estimate pore size in the field.
Below are abbreviations, descriptors, and criteria for
describing pores in the field:
Abundance No./Unit
Classes Area
1 — few <1
2 — common 1-5
3 — many >5
Size Classes Diameter Unit Area
vf — very fine <0.5 mm 1 cm2
f — fine 0.5-2 mm 1 cm2
m — medium 2-5 mm 10 cm2
cos — coarse 5-1 Omm 10 cm2
vcos— very coarse >10mm 1 m2
Distribution within Horizons
in — inped (most roots and pores are
within peds)
ex — exped (most roots and pores follow
interfaces between peds)
Types of Pores
v — vesicular (approximately spherical or
elliptical)
t — tubular (approximately cylindrical and
elongated)
i — irregular
3.1.5 Zones of Increased
Porosity/Permeability
Weathering and other soil-forming processes often
increase the secondary porosity and permeability of un-
consolidated materials. In addition, the mode of deposition
of unweathered materials may create vertical and lateral
variations in permeability that should be described. In-
creased secondary porosity is usually confined to the zone
of soil weathering near the surface. Buried soils
(paleosols) in glaciated areas represent zones of potential
lateral movement of contaminants due to increased secon-
dary porosity, if underlain by less permeable material.
i
-------
3.1.5a Soil Structure Grades
Soil structure is an important feature that affects
the movement of contaminants in soil. Contaminants often
move preferentially along the interfaces between soil
structure units. SCS describes soil structure according to
shape (see Figure 3-6 for illustrations), grade, and size
(see Figure 3-7 for charts). Below are abbreviations,
descriptors, and criteria for describing soil structure in the
field:
Grade
0 —
1 —
2 —
3 —
structureless (massive or single grain)
weak (poorly defined individual peds)
moderate (well formed peds, but
not distinct)
strong (durable peds, quite evident in
place; will stand displacement)
Size
vf —
f —
m —
c —
vc —
very fine
fine
medium
coarse
very
coarse
pl-platy
gr-
granular
cr-
crumb
<1 mm
1-2 mm
2-5 mm
5-10 mm
>10 mm
Shape
abk-
angular
blocky
sbk-
subangular
blocky
<5 mm
5-10 mm
1 0-20 mm
cl-
columnar
pr-
prismatic
<10 mm
10-20 mm
20-50 mm
20-50 mm 50-1 00 mm
>50 mm
>100 mm
Accurate identification of columnar or prismatic
structure generally requires a soil pit. Blocky structure can
usually be identified in cores taken from thin-walled
samplers, but size class cannot always be accurately
identified. Augers disturb the soil too much to allow ac-
curate description of soil structure.
3.1.5b Extrastructural Cracks
Cracks are macroscopic vertical planar voids with
a width much smaller than length and depth, which result
from soil drying. Extrastructural cracks extend beyond the
planar surfaces between soil structural units and represent
Field Description and Analysis of Soils
49
-------
Field Description and Analysis of Soils
50
*.*
*
Figure 3-6. Drawings illustrating some of the types of soil
structure: A, prismatic; B, columnar; C, angular blocky; D,
subangular blocky; E, platy; and F, granular.
-------
Shape
10
20
Platy
Granular Columnar
Blockv
mm Crumb ' Prismatic
2
3
4
5
7
10
12
20
50
fine
medium
coarse
coarse
very
fine
fine
medium
coarse
very
fine
fine
medium
Figure 3-7. Charts for estimating size class of different
structural units (see also Figure 3-5 for platy, granular, and
crumb structures).
Field Description and Analysis of Soils
51
-------
Field Description and Analysis of Soils 52
major potential channels for increasing infiltration of water
during precipitation and preferential contaminant move-
ment into the soil. The presence of irreversible cracks in
the soil increases ponded infiltration (see Section 3.2.5).
SCS define four major types of extra-structural
cracks:
Surface-initiated reversible cracks form as a
result of drying from the surface downward. They
close after relatively slight surficial wetting and
have little influence on ponded infiltration rates.
Surface-initiated irreversible cracks form from
freeze-thaw action and other processes, and do
not close completely when rewet. They extend to
the depth that frost action has occurred, and act to
increase the ponded infiltration rates.
Subsurface-initiated reversible cracks form in
subsoils with a high shrink-swell potential as the
soil dries from field capacity. They close in a matter
of days if the horizon becomes moderately moist or
wet. They extend to the surface (unless the surface
horizon does not permit the propagation of cracks),
and increase ponded infiltration and rates of soil
evaporation.
Subsurface-initiated irreversible cracks are per-
manently present in the subsurface.
Tests for Crack Characterization
A crack index value may be obtained by using a
blunt wire, approximately 2 mm in diameter. More detailed
characterization of cracks can be accomplished by pour-
ing loose sand into the crack and excavating after wetting
and after the crack has closed.
Penetrant cracks are 15 cm or more in depth as
measured by an inserted wire. Surface-connected cracks
occur at the ground surface or are covered by up to 10 to
15 cm of soil material that has very high or high saturated
hydraulic conductivity with soft, very friable, or loose con-
sistency. Surface connected cracks increase ponded
infiltration.
Crack development is primarily associated with
clayey soils and is most pronounced in high shrink-swell
soils (see Section 3.1.7d).
-------
3.1.5c Roots
The penetration of plant roots into the soil in-
creases the secondary porosity of soil, and, after the plant
dies and the root decomposes, leaves channels for more
rapid flow of water through the soil. The absence of roots
in the near surface is also an indication of reduced
porosity/permeability.
A soil pit is required to accurately describe soil
roots. SCS conventions for describing roots in soil are
similar to those for soil pore description, although the
criteria for abundance and size classes are different from
those for pores. These classes are described below:
Abundance No./Unit
Classes Area
1 — few <1
v1 — very few <0.2
ml — moderately few 0.2-1
2 — common 1-5
3 — many >5
Unit
Size Classes Diameter Area
vf — very fine <0.5 mm 1 cm2
f — fine 0.5-2 mm 1 cm2
m — medium 2-5 mm 10 cm2
cos — coarse 5-1 Omm 10 cm2
vcos— very coarse >10mm 1 m2
Distribution within Horizons
in — inped (most roots are within peds)
ex — exped (most roots follow interfaces
between peds)
Figure 3-5 provides charts for estimating root size.
3.1.5d Surface Features
Surface or lateral features such as clay films and
silt coatings are often indicators of areas of increased per-
meability in the soil. Stress formations, on the other hand,
are good indicators of active shrinking and swelling of
clays in the soil. SCS describes lateral features according
to (1) kind, (2) amount, (3) distinctness, and (4) location.
Section 13.1 in SCS (1971) provides more detailed
guidance on the observation of features on ped faces. A
Field Description and Analysis of Soils 53
-------
Field Description and Analysis of Soils 54
stereoscopic microscope illuminated by a high-intensity
lamp is useful for more detailed observation of lateral
features. Criteria for descriptors of lateral features are as
follows:
Kind Amount
Coatings vf — very few (<5%)
Clay films f — few (5-25%)
Clay bridges c — common (25-50%)
Sand m — many (>50%)
Silt
Other
Stress formations
Pressure faces
Slickensides
Distinctness
Faint—Requires 10 power magnification; little con-
trast in properties with material.
Distinct—Detectable without magnification al-
though magnifier or other tests may be required for
positive identification. Contrast in properties with
adjacent material evident.
Prominent—Conspicuous without magnifier;
properties contrast sharply with adjacent material.
Location
Surfaces of peds, channels, pores, primary par-
ticles or grains, soil fragments, rock fragments,
nodules, or concretions.
3.1.5e Sedimentary Features
Sedimentary features in unweathered uncon-
solidated materials often allow inferences to be made
about the depositional history of the material and, when
combined with particle-size distribution data, assist in the
location of zones of more rapid lateral movement of con-
taminants. The main features described are type and
orientation. The following types and orientations are taken
from the Indiana Department of Environmental Manage-
ment guidelines for description of unconsoiidated material
at hazardous waste sites (IDEM, 1988):
-------
Type
(describe thickness) Orientation
1 — bedding/lamination ver — vertical
2 — cross-stratification hor — horizontal
3 — deformation obi — oblique
in bedding
4 — bedding/surface
structures
5 — fossils/bioturbation
6 — massive
(no structure)
3.1.6 Zones of Reduced
Porosity/Permeability
Low-permeability soil or other horizons in uncon-
solidated material inhibit the downward movement of con-
taminants. Ground water tends to perch above such zones
and transport contaminants laterally. Soil features indicat-
ing such zones include (1) slowly permeable genetic
horizons, (2) very firm and very hard consistency classes,
(3) high bulk density, (4) root restricting layers, and (5)
high penetration resistance.
3.1.6a Genetic Horizons
Fragipans and cemented or indurated horizons
formed by the precipitation of carbonates, silica, iron
oxides, or other minerals are distinctive features of certain
soil series. Determination of degree of cementation re-
quires wetting the sample for at least an hour (see 3.1.6b).
There are substantial problems in the field iden-
tification of fragipans. Witty and Knox (1989) suggest the
following essential characteristics of a fragipan:
1. One or more of the subhorizons are brittle at or
near field capacity throughout the subhorizon or at
least in any large prismatic structural units that
have horizontal dimensions of 10 cm or more and
constitute 60 percent or more of the volume.
2. Air-dried fragments of 5 to 10 cm in size from any
part of the horizon slake or fracture when placed in
water.
^
Field Description and Analysis of Soils 55
-------
Field Description and Analysis of Soils 56
tt'ttx-x-W'X'K'X'K^M'X'f^^
3. Roots are virtually absent, except in vertical
streaks, between any large prismatic structural
units that have horizontal dimensions of 10 cm or
more and that constitute 60 percent or more of the
volume.
4. There is evidence of pedogenesis in the form of
mottles, clay films, or vertical streaks that define
large prisms.
Many or all fragipans also exhibit one or more of
the following characteristics:
1. Relatively low vertical saturated hydraulic conduc-
tivity (slow or very slow permeability), as measured
or as revealed by evidence of perched water in the
form of mottles, an E horizon, or seasonal seepage
immediately above the pan.
2. High bulk density (commonly <35 percent porosity
of the fine-earth fraction) relative to overlying
horizons.
3. Large prisms defined by vertical streaks that are
arranged in a polygonal pattern on a horizontal
exposure.
Both vertical and horizontal exposure of the
horizon is required for complete description of a fragipan.
3.1.6b Rupture Resistance
(Consistency)
Rupture resistance, also called consistence or con-
sistency, is a readily observed feature in the field. Terms
used to describe rupture resistance vary depending on the
moisture content of the sample tested (see Table 3-5).
The very firm (moist) and very hard (dry) classes, and
those that are firmer or harder, are indicative of reduced
porosity/permeability. The footnotes to Table 3-5 describe
the procedure for estimating rupture resistance classes.
SCS recommends practice with scales to gain a more
precise tactile sense of the transition between the different
classes.
Cementation Test. Degree of cementation can be
estimated by applying the rupture resistance tests in Table
3-5 to an air-dried specimen that has then been placed in
water for at least an hour. Terms used to describe
-------
Table 3-5. Rupture Resistance (Consistency) Classes
Moist
(>DS*)
Dry
(DM, DV*)
Conditions of Failure**
Stress
Applied***
Loose
Very
friable
Friable
Firm
Very
firm
Extremely Very
firm hard
Rigid
Very
rigid
Loose Specimen not obtainable —
Soft Fails under very slight <8N
force applied slowly
between thumb and
forefinger
Slightly Fails under slight force 8-20N
hard applied slowly between
thumb and forefinger
Hard Fails under moderate 20-40N
force applied slowly
between thumb and
forefinger
Fails under strong force 40-80N
applied slowly between
thumb and forefinger
Cannot be failed between 80-1 SON
thumb and forefinger but
can be by applying
pressure slowly with
hands; fails if placed
on a hard surface and
gentle force applied
underfoot
Extremely Cannot be failed in hand, 160-800N
hard but can be crushed or
broken underfoot by the
full body weight applied
slowly
Rigid Cannot be failed underfoot 800N-3J
by full body weight but
can be by <3J blow
Very Cannot be failed by blow >3J
rigid of 3J
Source: Adapted from Soil Survey Staff (1991).
*See Table 3-8 for definitions of abbreviations.
"Standard specimens should be block-like and 25 to 30 mm on
edge. If specimens smaller than the standard size must be
used, corrections should be made for class estimates (i.e., a 10-
cm block will require about one-third the force to rupture as will a
30-cm block). Stress is applied along the vertical in-place axis of
(Continued)
Field Description and Analysis of Soils
57
-------
Field Description and Analysis of Soils 58
:*x*:*:*:*x*:*x*:*:-x-x*:*xw^^
Table 3-5. (Continued)
the specimen by compressing it between extended thumb and
forefinger, between both hands, or between the foot and a non-
resilient flat surface. If the specimen resists compression, a 1 -kg
weight is dropped from progressively greater heights up to 30
cm, until rupture.
***Both force (newtons; N) and energy (joules; J) are employed.
One newton is equivalent to the force necessary to accelerate a
1 -kg mass 1 meter per second per second. One joule is the ener-
gy delivered by dropping a 1 -kg weight 10 cm. A tactile sense of
class limits may be learned by applying pressure through the
tips of the fingers or ball of the foot to postal or bathroom scales.
cementation are as follows (use Table 3-5 to estimate
stress applied):
Class Stress Applied
Uncemented <8N
Weakly cemented 8-80N
Moderately cemented 80-800N
Strongly cemented 800N-3J
Indurated >3J
Other consistence classes used in the field are
plasticity and stickiness. These are a function of clay con-
tent and are covered in Section 3.1.7a.
EPA's ESES defines the following consistency
classes:
High: A soil when wet that shows high cohesion of
soil particles, or adhesion of soil particles to other
substances.
Moderate: A soil when moist that shows moderate
cohesion or adhesion.
Low to Weak: A soil, usually dry, that shows
reduced or poor cohesion or adhesion.
Cemented: A type of soil that remains hard or brit-
tle after an air-dried specimen has been placed in
water for at least 1 hour.
3.1.6c Bulk Density
Accurate measurement of bulk density, expressed
as g/cc, requires weighing a known volume of soil or
determining both the weight and volume of an undisturbed
-------
soil sample. Some commonly used methods are described
below.
Core Method. This method involves collecting a
core of a known volume using a thin-walled sampler (to
minimize disturbance of the soil sample), and transporting
the core to the laboratory for weighing. Inserting a sam-
pling cylinder inside the sampling tube allows other meas-
urements to be made in the laboratory such as pore-size
distribution, hydraulic conductivity, and water retention.
Core samples should be placed in moisture-proof con-
tainers to maintain field moisture content.
Hole or Excavation Method. Bulk density can be
determined directly in the field by excavating a quantity of
soil, drying and weighing it (in the field or laboratory), and
determining the volume of the excavation. This volume
can be determined by measuring the volume of sand re-
quired to fill the excavation, or placing a rubber balloon in
the excavation and measuring the amount of water or
some other liquid required to fill the space. SCS (1971)
and Blake and Hartge (1986) describe equipment and field
procedures for these methods.
Coated-Clod Method. Bulk density of cohesive
soils can be measured by coating a clod with a saran-
ketone mixture and comparing the weights of the clod in
air and water. Blake and Hartge (1986) describe this pro-
cedure in detail. This procedure can be done in a field
laboratory with a scale that weighs accurately to 1 gram in
a range of 500 to 1,000 grams. SCS (1971) describes pro-
cedures for determining the field-moist density and dry
density of a clod. With these measurements, one can
determine the minimum and maximum density, field mois-
ture capacity, percentage of volume change, and ratio of
moist and dry volumes for calculation of the coefficient of
linear extensibility (COLE—see Section 3.1.7d).
The bulk density at which resistance to root penetra-
tion is high varies with texture as follows (SCS, 1983):
Family Texture Bulk Density
Sandy >1.85
Coarse-Loamy >1.80
Fine-Loamy >1.70
Coarse-Silty >1.60
Fine-Silty >1.50
Fine >1.35
Field Description and Analysis of Soils 59
-------
Field Description and Analysis of Soils 60
3,1,6d Root Restricting Layers
Root restricting layers are an indicator that con-
taminants will tend to move laterally along the top of the
restrictive layer rather than vertically in the soil profile.
SCS classifies root restricting soil layers, whether
they are genetic horizons or not, based on a combination
of other soil properties as follows (the sections that
describe specific features are indicated in parentheses).
Root depth observations are the most reliable in-
dicator, with horizons incapable of supporting more than a
few fine or very fine roots (see Section 3.1.5c) considered
root restricting.
Continuously cemented zones (see Section
3.1.6b) of any thickness are considered root restricting.
Zones >10 cm below the rooting zone are con-
sidered root restricting if they exhibit the following charac-
teristics when water state is very moist or wet (Section
3.2.1): (1) structure is massive, platy, or is weak of any
type for a vertical repeat distance of <10 cm (Section
3.1.5a); and (2) rupture resistance is very firm (firm, if
sandy) or extremely firm (Section 3.1.6b), or has a large
penetration resistance (Section 3.1.6e).
When a root restricting layer is present, soils are
classified according to the following depth classes:
Very shallow <25 cm
Shallow 25 to 50 cm
Moderately deep 50 to 100 cm
Deep 100 to 150 cm
Very deep >150cm
3.1.6e Penetration Resistance
(Compaction)
Penetration resistance is the capacity of the soil in
its confined state to resist penetration by a rigid object. It
is usually reported as megapascals (1 MPa = 10 bars or
9.9 atmospheres of pressure). Large penetration
resistance is an indicator of compaction or other soil fea-
tures that impede vertical flow of contaminants (see Sec-
tion 3.1.6a and d). Truck or tractor-mounted cone
penetrometers are commonly used in engineering
investigations and are increasingly being used to charac-
terize the subsurface at contaminated sites.
-------
For soil descriptions, the pocket penetrometer, a
hand-operated, calibrated-spring penetrometer, is a useful
tool for helping identify root restricting layers. It is simple
to operate, and can be pushed into the soil surface, core
samples, or soil exposed in an open pit investigation.
Penetration resistance depends strongly on water
state (Section 3.2.1), which should be specified. Orienta-
tion of the axis of insertion should also be specified. SCS
defines penetration resistance classes based on the pres-
sure required to push a pocket penetrometer with a
diameter of 6.4 mm a distance of 6.4 mm into the soil in
about 1 second, as follows:
Classes Penetration Resistance (MPa)
Small <0.1
Extremely low <0.01
Very low 0.01-0.1
Intermediate 0.1-2
Low 0.1-1
Moderate 1-2
Large >2
High 2-4
Very high 4-8
Extremely high >8
Compacted near-surface zones resulting from
equipment traffic or tillage will have large penetration
resistance, and higher rupture resistance (Section 3.1.6b)
and bulk densities (Section 3.1.6c) than undisturbed near-
surface horizons.
Soil Survey Staff (1991) and Bradford (1986)
provide further guidance on use and interpretation of
pocket penetrometer readings.
EPA's ESES uses the following soil compaction
classes:
High: Surface soils have been subject to high com-
paction and consequent effects on soil structure,
such as by vehicular and foot traffic, or livestock.
Moderate: Surface soils have been less subjected
to compaction, either through reduced applications
and frequency of pressure on surface soils or be-
cause the soil structure is more resistant to
compaction.
Field Description and Analysis of Soils 61
-------
Field Description and Analysis of Soils 62
Low to Slight: Surface soils are only slightly af-
fected by compaction, either because of resistance
to compaction or because they are less subject to
application of compacting stressor.
3.1.7 Soil Engineering Parameters and
Properties
Texture, clay content (amount and types of clays),
and strength behavior at different moisture contents are
the key properties affecting soil engineering. A number of
classification systems have been developed for the selec-
tion of soil materials and design of foundations and
earthen structures. The ASTM (Unified) soil classification
is the most widely used at contaminated sites and is the
only one covered in this guide.
Only field procedures for preliminary estimation of
soil engineering properties are covered here. Laboratory
tests are required for accurate determination of soil en-
gineering properties. Once the Unified soil class has been
identified, other properties such as permeability and
suitability for different types of engineering applications
can be estimated using Figure 4-14 in SCS (1990).
3.1.7a Unified (ASTM) Texture
Form 3-2 can be used to record the results of 11
tests for field classification of soil texture for engineering
uses. These tests are drawn from Brown et al. (1991),
SCS (1990), and Soil Survey Staff (1991). Figure 3-8 sum-
marizes how the results of these tests are used to es-
timate texture in the Unified soil classification system.
Procedures for specific tests identified in Figure 3-8 are
described below, along with some alternative versions
described by Soil Survey Staff (1991):
Test 1 - Coarse-Grained Soil Test
a. Spread a sample of soil on a flat surface (clip-
board) and examine the particles.
b. Approximate the grain size by visual inspection.
c. If more than 50 percent of the grains are easily
distinguished by the unaided eye, the material is a
coarse soil; if less than 50 percent of the grains
are easily distinguished by the unaided eye, the
material is a fine soil.
-------
Form 3-2. Unified (ASTM) Field Texture Determination Form
(adapted from Brown et al., 1991)
Sample No. Site: Date:
Sampling Location:
Person(s) Performing Test:.
SANDS AND GRAVELS
Test 1 (coarsegrained)
Test 2 (gravel)
Tests (finegrained)
COMMENTS:
SILTS AND CLAYS
Test 4 (plasticity)
Test 5 (ribbon)
Test 6 (liquid limit)
Test 7 (clod strength)
Test 8 (dilatancy)
Test 9 (toughness)
Test 10 (stickiness)
Test 11 (organic soils)_
COMMENTS:
tftWfcWSWSfc::^
Field Description and Analysis of Soils 63
-------
F/e/d Description and Analysis of Soils 64
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Figure 3-8. Summary of field tests for Unified (ASTM) soil
textural classification (Source: SCS, 1990).
-------
d. If some of the particles could be aggregates of fine
particles, saturate a small sample of the soil with
water.
e. Rub a large marble-sized (2 cm) sample between
the thumb and forefinger. Sand grains (coarse
material) will feel rough and gritty, whereas
aggregates of fine materials will break down and
feel silky.
Alternative Jar Method (Soil Survey Staff, 1991)
f. Thoroughly shake a mixture of soil and water in a
straight-sided jar or test tube, and allow the mixture
to settle.
g. Sand sizes will fall out first, in 20 to 30 seconds;
successively finer particles will follow. Estimate the
proportions of sand and fines from their relative
volumes.
Test 2 - Sand/Gravel Tests
2.a Gravel/Sand
a. Spread a representative sample of soil on a flat
surface.
b. If more than one-half of the visible grains are
greater than 2 mm, the material is gravel; if they
are not, it is a sand.
2.b Clean/Dirty Test
c. Remove any coarse material greater than 2 mm in
diameter.
d. Saturate the remaining materials with water and
work it with your hands.
e. Hands will not be stained when fines are less than
5 percent (GW or GP; SW or SP); hands will be
stained when there is more than 12 percent fines,
and weak casts can be formed (GM or GC; SM or
SC).
2.c Sorting Test
f. Take a second sample of soil and place it on a flat
surface. Spread it out and observe the grain size
distribution.
g. If coarse materials consist of evenly distributed
particle sizes, the material is well graded (GW or
SW); if they are chiefly of one size particle or large
::::::::::::::¥:::S^
Field Description and Analysis of Soils 65
-------
Field Description and Analysis of Soils 66
and small particles without intermediate sizes, the
material is poorly graded (GP or SP).
Test 3 - Fine-Grained Test
a. When Test 1 indicates fine-grained soils, complete
Tests 4 through 7 to determine if the material is
clayey or silty.
b. If Test 2b indicates dirty sands or gravels (>12 per-
cent fines), complete Test 4 to determine whether
fines are plastic or nonplastic.
Test 4 - Plasticity Test
a. Wet and mold a small 2 x 2 x 2 cm (3 teaspoons)
soil sample so that it can be rolled into a thread
without crumbing. The material will not stick to the
hands if the correct amount of water is added.
b. Roll the moist soil with the palm of the hand on any
clean, smooth surface, such as a piece of paper or
clipboard, to form a coarse thread and pull it apart.
c. Observe difficulty of pulling thread apart: GC, SC,
CH, or CL = tough (hard to pull apart); GM, SM, or
MH = medium tough; GM, SM, or ML = weak
(easily pulled apart).
Alternative Plasticity Test (from Soil Survey
Staff, 1991)
d. Find the minimum thickness a 4-cm long roll must
have to support its own weight: nonplastic = >6 mm;
slightly plastic = 4-6 mm; moderately plastic = 2-4
mm; very plastic = <2 mm.
Test 5 - Ribbon Test
a. Take a quantity of soil measuring at least 2x2x2
cm (3 teaspoons). Square and wet it with water
until it reaches a plastic state. This condition
prevails when the soil contains just enough mois-
ture so that it can be rolled into 3-mm diameter
threads. These threads or ribbons are formed by
squeezing and working the sample between the
thumb and forefinger. Plastic limit is governed by
clay content.
b. Observe properties of ribbon: ML = weak, (breaks
easily); MH = hard (does not break easily); CL =
flexible with medium strength; CH = strong and
flexible.
-------
Test 6 - Liquid Limit Test (from SCS, 1990)
a. Take a pat of moist soil with a volume of about
8 cc (1.2 in.3) and add enough water to make the
soil soft but not sticky.
b. Rapidly add enough water to cover the outer sur-
face, and break the pat open immediately.
c. A positive reaction has occurred when the water
has penetrated through the surface layer: LL = low,
if water has penetrated (ML, CL); LL = high, if the
water has not penetrated (MH, CH). [Note: direct
sunlight facilitates observation of this phenomena].
Test 7 - Dry Crushing/Clod Strength Test
a. Obtain a dry block of soil at least 2 cm (3/4 in.) in
its smallest dimension.
b. Crush the clod between fingers and observe the ef-
fort required: ML = easily crushed; CL or MH =
medium-hard to break; CH = almost impossible to
break.
Test 8 - Dilatancy Test (from SCS, 1990)
a. Mold material into a ball about 15 mm (1/2 in.) in
diameter. Add water, if needed, until it has a soft
but not sticky consistency.
b. Smooth the soil in the palm of one hand with the
blade of a knife or spatula.
c. Shake horizontally, striking the side of the hand
against the other several times. Note the ap-
pearance of water on the surface. Squeeze the
sample and note the disappearance of water.
d. Describe the reaction: none = no visible change
(CH); slow = water appears slowly on the surface
during the shaking and does not disappear or dis-
appears slowly when squeezed (CL, MH); rapid =
water appears quickly on the surface during shak-
ing and disappears quickly when squeezed (ML).
Test 9 - Toughness Test (from SCS, 1990)
a. Take the specimen for the dilatancy test and shape
it into an elongated pat and roll it on a hard surface
or between hands into a thread about 3 mm (1/8
in.) in diameter. (If it is too wet to roll, spread it out
and let it dry.)
Field Description and Analysis of Soils 67
-------
Field Description and Analysis of Soils 68
:*x*:*:*:*:*:-:-:*:*:*:«^^^^^^
b. Fold the thread and reroll repeatedly until the
thread crumbles at a diameter of 3 mm (1/8 in.).
The soil has reached its plastic limit.
c. Note the pressure required to roll the thread and
the strength of the thread: circumferential breaks =
CH or CL material; longitudinal cracks and
diagonal breaks = MH.
d. After the thread crumbles, lump the pieces
together and knead until the lump crumbles.
e. Note the toughness of the material during knead-
ing. Describe toughness: low = only slight pressure
required to roll the thread near the plastic limit, the
thread and lump are weak and soft (ML); medium =
medium pressure is required to roll the thread near
the plastic limit, the thread and lump have medium
stiffness (CL, MH); high = considerable pressure
required to roll the thread near the plastic limit, the
thread and lump are very stiff (CL, CH); nonplastic
= thread cannot be rolled (CL, CH).
Test 10 - Stickiness Test
a. Saturate a sample of the soil and let it dry on the
hands.
b. Observe ease with which soil is rubbed off: ML is
brushed off with little effort; CL or MH require
moderate effort to brush off; CH requires rewetting
to completely remove.
Alternative Stickiness Test (from Soil Survey
Staff, 1991)
c. Saturate a sample of the soil and press between
thumb and forefinger.
d. Observe the adhesion to thumb and forefinger
when they are pulled apart: nonsticky = practically
no adhesion (ML); slightly sticky = sticks to thumb
or forefinger (MH); sticky = adheres to both,
stretches slightly before breaking (CL); very sticky
= adheres to both, stretches decidedly (CH).
Test 11 - Organic Soils Test
a. Smell soils suspected of having a high organic
matter content.
b. A distinctive, pungent musty odor is indicative of
organic soils.
-------
c. Feel texture of soil: PT = spongy or fibrous texture;
OL or OH = nonfibrous.
d. If nonfibrous, do plasticity test (Test 6): OL = low
plasticity; OH = high plasticity.
3.1.7b Atterberg Limits
Atterberg limits define various states of fine-
grained soil material ranging from dry to liquid. The
shrinkage limit (SL) is the water content at which a fur-
ther reduction in water does not cause a decrease in the
volume of the soil mass. The plastic limit (PL) is the
water content at which soil changes from a semi-solid to a
plastic state. At the plastic limit, a fine-grained soil will just
begin to crumble when rolled into a thread approximately
3 mm (1/8 in.) in diameter. The liquid limit is the water
content at which soil consistency changes from a plastic to
a liquid state. This is the water content at which a pat of
soil, cut by a groove 2 mm wide will flow together for a dis-
tance of 13 mm (1/2 in.) under the impact of 25 blows in a
standard liquid limit apparatus.
Accurate determination of Atterberg limits requires
collection of samples for laboratory analysis.
3.1.7c Shear Strength
Shear strength can be estimated approximately in
the field by the ease with which a sample can be
penetrated by the thumb, as described in Table 3-6.
Table 3-6. Field Estimation of Soil Shear Strength
Consistency Identification Shear Strength
Procedure (tons/ft2
or kg/cm2)
Soft Easily penetrated several <0.25
inches by thumb
Firm Penetrated several inches by 0.25 to 0.50
thumb with moderate effort
Stiff Readily indented by thumb, but 0.50 to 1.00
penetrated only with great effort
Very Readily indented with thumbnail 1.00 to 2.00
Stiff
Hard Indented with difficulty by >2.00
thumbnail
Source: SCS (1990).
Field Description and Analysis of Soils 69
-------
Field Description and Analysis of Soils 70
siy*:*:!:*?:^
3.1.7d Shrink-Swel!
Certain clays shrink when pore water is lost during
drying and subsequently swell during wetting. High shrink-
swell clays are of concern at contaminated sites because
deeply penetrating cracks create pathways for con-
taminant movement during the early stages of the wetting
phase. Where sodium rich clays with high dispersivity
exist in the subsurface, a form of erosion called piping is
also a concern.
SCS defines shrink-swell potential classes based
on linear extensibility (LE (%) = 100 x moist length - dry
length/dry length) or the coefficient of linear extensibility
(COLE = LE/100), as follows:
Class LE(%) COLE Dbd/Mdb
Low <3 <0.03 <1.1
Medium 3-6 0.03-0.06 1.1-1.2
High 6-9 0.06-0.09 1.2-1.3
Very high >9 >0.09 >1.3
LE can be measured by collecting a core from a
wet or moist soil, carefully measuring its wet length, and
setting it upright in a dry place. If the sample shrinks in a
symmetrical shape without excessive cracking or crum-
bling, its length should be measured and LE calculated. If
the core crumbles or cracks, the coated clod method for
bulk density measurement (see Section 3.1.6c) and the
ratio of dry bulk density (Dbd) to moist bulk density (Mbd)
should be used to place samples in shrink-swell classes
(see table above). SCS (1971, Section I4.3) and SCS
(1983) provide additional information on these procedures.
SCS (1971) also describes a simple test for rough deter-
mination of maximum potential shrinkage and density of
disturbed soils.
3.1.7e Corrosivity
SCS soil series interpretation sheets give separate
corrosion potential ratings for uncoated steel and for con-
crete. If classification of a soil is uncertain, corrosivity can
be estimated using the following field and laboratory-
measured parameters:
Uncoated steel — Texture (Section 3.1.2), water
table (Section 3.2.2), drainage class (Section
3.2.4), total acidity or extractable acidity as a rough
equivalent to total acidity (Section 3.3.3), resistivity
-------
at field capacity, and conductivity of saturated
extract (Section 3.3.6).
Concrete — Texture (Section 3.1.2), reaction
(Section 3.3.4), and laboratory analysis of sodium
and/or magnesium sulfate (ppm) and sodium
chloride (ppm).
Table 3-7 shows criteria for soils with high,
moderate, and low corrosion potential for uncoated steel.
Table 603-8 in SCS (1983) provides criteria to estimate
corrosion potential for concrete.
3.1.8 Soil Temperature/Temperature
Regime
Soil temperature affects evaporation rates of water
and volatile contaminants and influences the amount of
microbiological activity in the soil. In soil classification,
mean annual or summer soil temperature and the relation-
ship between mean summer and mean winter soil
temperature are used for placement in soil temperature
regimes.
Ground-water temperature gives a close estimate
of mean annual soil temperature if monitoring wells are
available with water at a depth of 1 0 to 20 meters. Alterna-
tively, the average of four temperature measurements
taken at a depth of about 50 cm equally spaced
throughout the year gives a good estimate of mean annual
soil temperature. For mean summer temperature, readings
may be taken on June 15, July 15, and August 15, and for
mean winter temperature, on December 15, January 15,
and February 15.
SCS (1971, Section I4.4) and Smith et al. (1960)
describe more detailed procedures for soil temperature
regime measurement, including special procedures where
ground water or bedrock is shallow. Taylor and Jackson
(1986) discuss types of thermometers and methods for
measuring soil temperature for other applications.
EPA's ESES defines the following soil temperature
classes based on point thermal measurements taken on
the surface or with depth of soil at a point in time, or over
a period of time:
High:38°C(100.4°F)
Medium: 8-38°C (46.4 to 100.4°F)
Low: <8°C (46.4°F)
Field Description and Analysis of Soils 71
-------
Field Description and Analysis of Soils
72
Table 3-7. Guide for Estimating Risk of Soil Corrosion
Potential of Uncoated Steel
Class
Low
Drainage Class
and Texture
Excessively drainec
Total
Acidity*
(meq/
100g)
i <8
Resis-
tivity*
(Ohm/
cm)
>5,000
Conduc-
tivity*
(mmhos/
cm)
<0.3
coarse-textured or
well-drained coarse-
to medium-textured soils;
or, moderately well
drained, coarse-textured
soils; or, somewhat
poorly drained
coarse-textured soils
Moderate Well-drained, 8-12
moderately fine-textured
soils; or moderately well
drained, coarse- and
medium-textured soils;
or somewhat poorly
drained, moderately
coarse-textured soils;
or, very poorly drained
soils with stable high
water table
High Well drained, fine-
textured, or stratified
soils; or, moderately
well drained fine- and
moderately fine-textured
or stratified soils; or,
somewhat poorly
drained, medium- to
fine-textured or stratified
soils; or poorly drained
soil with fluctuating
water table
2,000 to
5,000
0.3 to
0.8
<2,000 >0.8
* See Table 603-7 in SCS (1983) for further guidance on how
measurements should be made and interpreted.
-------
3.2 Soil Hydrologic Parameters
3.2.1 Moisture Conditions (Soil Water State)
The terms used to describe soil properties may
vary depending on the soil moisture content of the sample
being observed. Soil water state is a more precise term for
moisture conditions (Soil Science Society of America,
1987). Soil water state should be noted for any observa-
tions of properties that may vary with moisture content,
such as color and consistency.
Table 3-8 describes three main soil water state
classes (dry, moist, and wet) and eight subclasses within
these categories, as defined by SCS. The water state
classification of a particular soil sample will depend on (1)
texture (whether it is coarse or not), (2) how strongly water
is held by the soil (suction), and (3) the amount of
gravimetric water held by the soil in relation to the amount
held at specified reference suction pressures (i.e., 1,500
kPa for dry soils).
Referring to Table 3-8, the following can be used
as guidelines for field estimation of soil water state:
Dry (VD) — Very little visual or tactile change be-
tween field observation and after air-dried samples.
Moist (MD) — Visual or tactile change between
field observation and after air drying.
Wet — Water films evident, but no free water
(WN); free water present (WA).
Between moist/wet and moderately dry/very dry
separations, Soil Survey Staff (1991) describes four field
water state tests: (1) color value test, (2) ball test, (3) rod
test, and (4) ribbon test. These tests require calibration
with the results of tests on similar soils that have been
conducted at different known points on the moisture reten-
tion curve.
The following rules of thumb can be used to es-
timate actual percentages of water at different points on
the moisture characteristic curve:
Water (%) at 1,500 Kpa = 0.4 x estimated clay
content
Water (%) of air dry soil = 0.1 x estimated clay
content
Field Description and Analysis of Soils 73
-------
Field Description and Analysis of Soils
:*x*x-xott*:*:-:*:-:\x*:'W
Table 3-8. Water State Classes
74
'm^
Class
Criteria
Suction Retention
(kPa)* (% gravimetric moisture)
Dry (D)
Very dry (DV)
Moderately dry (DM)
Slightly dry (DS)
Moist (M)
Slightly moist (MS)
Moderately moist (MM)
Very moist (MV)
Wet (W)
Nonsatiated (WN)
Satiated (WA)
>1500
>1-1500
<.35 x % water at
1500kPa
.35 - 0.8 x% water at
1500kPa
0.8 to 1.0 % water at kPa
%waterat1500kPato
MWR
MWR** to UWR"
UWR** to 1 or 0.5 kPa
No free water
Free water present
Source: Soil Survey Staff (1991).
'Coarse soil material is considered wet at 0.5 kPa suction and
moist from 0.5 to 1500 kPa if it meets the following criteria: (1)
sand or sandy-skeletal family particle-size criteria, (2) coarser
than loamy fine sand, (3) <2 percent organic carbon, (4) <5 per-
cent water at 1500 kPa, and (5) computed total porosity of the
<2 mm fabric exceeding 35 percent.
"UWR = upper water retention = % water at 5 Kpa (coarse soil)
= % water at 10 KPa (other soil). MWR = midpoint water reten-
tion = halfway between UWR and % water at 1500 Kpa.
-------
Methods for accurately measuring moisture con-
tent in the field require relatively sophisticated equipment
and are not discussed further here (see Appendix D in
Cameron (1991), for information on field methods). The
same is true for accurate measurement of water retention
at different matric potentials (moisture characteristic
curves).
Moisture content and moisture characteristic
curves are most commonly measured in the laboratory
from samples collected in the field. Soil moisture tins with
a capacity for about 250 grams of soil, filled to the brim
and sealed with tape or plastic bags with any extra air
removed before sealing, are best for determining field
moisture content at the time of sampling. Undisturbed core
samples are best for laboratory measurement of moisture
characteristic curves.
SCS (1971, Section 14.1) describes procedures for
determining water content that can be done in a field
laboratory with the following equipment: balance accurate
to 0.1 g; oven with thermometer or thermostat, or stove,
hot plate, or infrared lamp; and thermometer with scale up
to150°C.
3.2.2 Water Table (Internal Free Water
Occurrence)
SCS does not define a class for saturation (i.e.,
zero air-filled porosity) because the term implies that all of
the pore space is filled with water, a situation which can-
not be readily evaluated in the field. Free water develops
positive pressure when its depth is below the top of a wet
satiated zone (the top of water in an unlined borehole after
equilibrium has been reached).
SCS classifies free water occurrence (perched or
regional water table) into classes depending on (1) thick-
ness (if perched), (2) depth, and (3) duration as follows:
Classes Criteria
Thickness if perched
Extremely thin (TE) <10 cm
Very thin (TV) 10 to 30 cm
Thin (T) 30 cm to 1 m
Thick (TK) >1 m
Field Description and Analysis of Soils 75
-------
Field Description and Analysis of Soils 76
Depth
Very deep (DV) >1.5m
Deep(D) 1.5 to 1 m
Moderately deep (DM) 1 to 0.5 m
Shallow (S) 0.5 m to 25 cm
Very shallow (SV) <25 cm
Cumulative Annual Duration
Absent (A) Not observed
Very transitory (TV) Present <1 month
Transitory (T) Present 1 to 3 months
Common (C) Present 3 to 6 months
Persistent (PS) Present 6 to 12 months
Permanent (P) Present continuously
3.2.3 Available Water Capacity
Available water capacity (AWC) is the amount of
plant-available soil moisture, usually expressed as inches
of water per inch of soil depth. It is commonly defined as
the amount of water held between field capacity and the
wilting point. AWC is important in developing water
budgets and designing drainage systems.
Determination of AWC requires sampling of soil for
moisture content when it is at field capacity. This requires
sampling just after the soil has drained after a period of
rain and humid weather, after a spring thaw, or after heavy
irrigation. SCS (1971, Section 14.1) describes several
other procedures for bringing a plot to field capacity by
wetting, and several methods for wetting clods or cores to
approximate field capacity. SCS (1983) provides further
guidance on calculation and estimation of AWC.
3.2.4 Saturated Hydraulic Conductivity and
Soil Drainage Class
The terms permeability and saturated hydraulic
conductivity are often used interchangeably to refer to the
ease with which water moves through the soil under
saturated conditions. Permeability rates are typically
reported in units of in./hr based on percolation tests;
saturated hydraulic conductivity may be reported in units
of u.m/s, m/s, cm/day, in./hr, or cm/hr. Accurate field meas-
urement of both saturated (KSat) and unsaturated hydraulic
-------
conductivity requires relatively complex instruments and
procedures that are not covered here (see Appendix D in
Cameron (1991) for information on these methods).
SCS currently defines six classes for describing
soils based on saturated hydraulic conductivity:
Saturated Hydraulic Conductivity
Class (u.m/s) ' (in./hr)
Very low (VL) <0.01 <0.001
Low(L) 0.01-0.1 0.001-0.01
Moderately low (ML) 0.1-1 0.01-0.14
Moderately high (MH) 1-10 0.14-1.4
High(H) 10-100 1.4-14.2
Very high (VH) >100 >14.2
Class placement is based on geometric mean of
multiple measurements.
Various methods have been developed for obtain-
ing rough estimates of KSat based on various soil proper-
ties. Table 3-9 provides a basis for estimating KSat based
on field observations of structure, texture, and pores. See
Section 3.1.2 for identification of textural classes, Section
3.1.4 for pore definitions, and Section 3.1.5a for definitions
of structural units.
O'Neal (1952) describes a procedure for somewhat
more precise estimation of soil permeability classes
(which are defined slightly differently from those listed
above) based on (1) structure, (2) shape and overlap of
aggregates, (3) visible pores, and (4) texture. Soil Survey
Staff (1991, Chapter 3) provides figures for KSat class
placement based on soil bulk density and texture.
Soil drainage class refers to the frequency and
duration of wet periods for the water regime associated
with undisturbed soil conditions. Table 3-10 summarizes
SCS criteria for seven soil drainage classes.
3.2.5 Infiltration
The amount of precipitation reaching the ground
surface that enters the soil is determined by the infiltra-
tion capacity. In a dry soil, infiltration is usually rapid, un-
less there is an impervious crust at the surface. As time
passes, infiltration slows until the ponded infiltration rate
is attained, which is determined by the saturated hydraulic
Field Description and Analysis of Soils 77
-------
Field Description and Analysis of Soils 78
:*:*:*:*^
Table 3-9, Guide for Estimating the Class of Saturated
Vertical Hydraulic Conductivity from Soil Properties
Class
Name Rate*
Soil Properties"
Very High <100
High
100-10
Moderate 10-1
Mod. Low 1-0.1
-Fragmental
-Sandy with coarse sand or sand
texture, and loose consistence
-More than 0.5 percent medium or
coarser vertical pores with high
continuity
-Other sandy, sandy-skeletal, or
coarse-loamy soil materials that are very
friable, friable, soft, or loose
-When very moist or wet has moderate
or strong granular structure; or strong
blocky structure of any size or prismatic
structure finer than very coarse, and
many surface features except stress
surfaces or slickensides on vertical
surfaces of structural units
-0.5 to 0.2 percent medium or coarser
vertical pores with high continuity
-Sandy in other consistence classes
except extremely firm or cemented
-10 to 35 percent clay with moderate
structure, except platy, or strong very
coarse prismatic structure; and with
common surface features except stress
surfaces or slickensides on vertical
surfaces of structural units
-0.1 to 0.2 percent medium or coarser
vertical pores with high continuity
-Other sandy classes that are
extremely firm or cemented
-18 to 35 percent clay with other
structures and surface conditions except
pressure or stress surfaces
-Greater than 35 percent clay and
moderate structure except if platy or
very coarse prismatic; and with common
vertical surface features except stress
surfaces or slickensides
-Medium or coarser vertical pores with
high continuity, but <0.01 percent
(Continued)
-------
Table 3-9. (Continued)
Class
Name Rate*
Soil Properties*
Low
0.1-0.01
Very Low <0.01
—Continuous moderate or weak
cementation
-Greater than 35 percent clay and
meets one of the following: weak
structure; weak structure with few or no
vertical surface features; platy structure;
common or many stress surfaces or
slickensides
-Continuously indurated or strongly
cemented and with less than
common roots
-Greater than 35 percent clay and
massive or exhibits horizontal
depositional strata and less than
common roots
Source: SCS (1983).
'Micrometers/second.
**A given soil profile would have most, but not necessarily all, of
the soil properties associated with a particular class.
Table 3-10. Criteria for SCS Soil Drainage Classes
Excessively drained. Water is removed very rapidly. Internal
free water occurrence commonly is very deep; annual dura-
tion is not specified. The soils are commonly very coarse tex-
tured, rocky, or shallow. Some are steep. All are free of
mottling related to wetness.
Somewhat excessively drained. Water is removed from the
soil rapidly. Internal free water occurrence commonly is very
deep; annual duration is not specified. The soils are usually
sandy and rapidly pervious. Some are shallow. A portion of
the soils are so steep that a considerable part of the precipita-
tion received is lost as runoff. All are free of the mottling re-
lated to wetness.
(Continued)
Field Description and Analysis of Soils
79
-------
Field Description and Analysis of Soils 80
x*;*:':tt«w:':*x<*H*x*:^
Table 3-10. (Continued)
Well drained. Water is removed from the soil readily but not
rapidly. Internal free water occurrence commonly is deep or
very deep; annual duration is not specified. Water is available
to plants throughout most of the growing season in humid
regions. Wetness does not inhibit growth of roots for sig-
nificant periods during most growing seasons. Well drained
soils are commonly medium textured. They are mainly free of
the mottling related to wetness.
Moderately well drained. Water is removed from the soil some-
what slowly during some periods of the year. Internal free
water occurrence commonly is moderately deep and tran-
sitory through permanent (Section 3.2.2). The soils are wet
for only a short time during the growing season, but long
enough that most mesophytic crops are affected. They com-
monly have a slowly pervious layer within the upper 1 m,
periodically receive high rainfall, or both.
Somewhat poorly drained. Water is removed slowly enough
that the soil is wet at shallow depth for significant periods
during the growing season. Internal free water occurrence
commonly is shallow and transitory or common. Wetness
markedly restricts the growth of mesophytic crops unless ar-
tificial drainage is provided. The soils commonly have one or
more of the following characteristics: contain a slowly per-
vious layer, have a high water table, receive additional water
from seepage, or occur under nearly continuous rainfall.
Poorly drained. Water is removed so slowly that the soil is wet
at shallow depths periodically during the growing season, or
remains wet for long periods. Internal free water occurrence
is shallow or very shallow and common or persistent. Free
water is commonly at or near the surface for long enough
during the growing season that most mesophytic crops can-
not be grown unless the soil is artificially drained. The soil,
however, is not continuously wet directly below plow-depth.
Free water at shallow depth is usually present. This water
table is commonly the result of a shallow, slowly pervious
layer within the soil, of seepage, of nearly continuous rainfall,
or of a combination of these.
Very poorly drained. Water is removed from the soil so slowly
that free water remains at or very near the ground surface
during much of the growing season. Internal free water occur-
rence is very shallow and persistent or permanent (Section
3.2.2). Unless the soil is artificially drained, most mesophytic
crops cannot be grown. The soils are commonly level or
depressed and frequently ponded. If rainfall is high or nearly
continuous, slope gradients can be moderate or high.
Source: Soil Survey Staff (1991).
-------
conductivity of the soil. Infiltration rate is usually measured
in rates of in./hr or cm/hr. Extrastructural cracks (Section
3.1.5D) may greatly increase infiltration rates compared to
soils with similar texture that do not have cracks.
SCS's permeability classification system (SCS,
1983) can be used to describe infiltration classes:
Permeability
Class (in./hr) (cm/hr)
Very slow
Slow
Moderately slow
Moderate
Moderately rapid
Rapid
Very rapid
<0.06
0.06-0.2
0.2-0.6
0.6-2.0
2.0-6.0
6.0-20
>20
<0.15
0.15-0.5
0.5-1.5
1 .5-5.0
5.0-15.2
15.2-50.8
>50.8
3.3 Soil Chemistry and Biology
Most procedures for characterization of soil
chemistry require collection of samples for laboratory
analysis. This section focuses on pH and mineralogical
parameters that can be tested in the field using relatively
simple equipment and procedures. Most of these tests are
drawn from SCS (1971).
3.3.1 Organic Matter
Organic matter (more precisely measured in the
laboratory as organic carbon) affects contaminant mobility
primarily by its high sorptive capacity. Accurate determina-
tion of total organic carbon (TOC) requires collection of
samples for laboratory analysis.
In the field, black or dark colors generally indicate
high organic matter content in near-surface horizons. In
most mineral soils, organic matter is moderately low to
high in the A horizon, and low in the subsoil. Severely
eroded soils, where the topsoil has been completely
removed; alluvial soils, where flooding deposits topsoil;
and buried soils may not follow this pattern. SCS defines
the following classes for organic matter:
Field Description and Analysis of Soils 81
-------
Field Description and Analysis of Soils 82
Class % Organic Matter
Very low (VL) <0.5
Low(LL) 0.5-1.0
Moderately low (ML) 1.0-2.0
Medium (MM) 2.0-4.0
High (HH) >4.0
Note that organic matter content is generally 1.7 to
2.0 times the TOC. An ignition test can be used in the field
to approximate organic matter content and check its con-
tribution to soil color. Equipment for this test includes (1)
thermometer and heat lamp, (2) portable gas soldering
torch, (3) a porcelain crucible or small tin can (not
aluminum), (4) wire brackets or tongs to hold the con-
tainer, and (5) a balance accurate to 0.1 grams.
Ignition Test Procedure (adapted from SCS, 1971)
1. Dry about 30 grams of soil to 110°C under a heat
lamp.
2. Weigh as accurately as possible about 10 grams of
dried soil and place in a crucible or tin, supporting
it with tongs or wire bracket.
3. Apply the flame of the torch to the bottom and
lower walls of the outside of the container. Por-
celain and metal glow red at 500°C. At this
temperature, organic matter is completely burned
and the water of hydration is removed from the
common oxide and clay minerals.
4. Observe changes in color in the specimen. Apply
heat more than once until there is no more change
apparent in the specimen. Do not apply the flame
directly to the sample if burning or oxidation are the
purpose of the test, because unpredictable reduc-
ing conditions exist in parts of the torch flame. If or-
ganic matter is the only material giving color to the
soil, it burns away leaving a whitish residue. See
Section 3.1.3 for interpretation of other color
changes.
5. When no more change is apparent, cool and weigh
sample again. The loss in weight divided by the
original weight times 100 equals the organic matter
in sandy soils and materials high in organic matter.
-------
If much clay is present, the loss also includes
water of hydration in the minerals.
Organic matter also reacts with hydrogen peroxide.
In contrast to manganese oxides (see Section 3.3.8), the
reaction starts slowly, builds up, and continues. Organic
matter reactions decrease with depth, whereas man-
ganese oxide reactions remain constant.
Test No. 11 in Section 3.1.7a describes proce-
dures for classifying organic soils in the Unified soil clas-
sification system. SCS uses a number of tests for
classification of organic soils (histosols) including sodium
pyrophosphate color, fiber percentages, and pH in 0.01 M
calcium chloride. Since organic soils do not commonly
occur at hazardous waste sites, these tests are not
described here. If organic soils are present at a site and
more detailed characterization is required, refer to Lynn et
al. (1974) and Appendix III in Soil Survey Staff (1975).
3.3.2 Odor
High organic matter content in soil is associated
with a distinctive, pungent musty odor (see Test 11 in Sec-
tion 3.1.7a). Organic rich topsoil in mineral soils can also
be distinguished from subsoil that is low in organic matter
by this odor.
Volatile organic contaminants can impart distinctive
odors to soil. Gasoline has an odor familiar to most
people; aging gives petroleum a musty odor. Some other
contaminants that may give soil a noticeable odor include
halogens, ammonia, turpentine, phenols and cresol,
picrates, various hydrocarbons, and unsaturated organic
pesticides.
Caution should be exercised in observing soil
odors. They should not be vigorously inhaled from any
soil, since even natural soils may contain potentially harm-
ful microorganisms. Soils where noticeable artificial odors
are present should be checked for volatile concentrations
using a detection instrument (HNu, organic vapor
analyzer, etc.). The health and safety officer should be
consulted to determine whether special protective equip-
Field Description and Analysis of Soils 83
-------
Field Description and Analysis of Soils 84
merit, such as a respirator, should be used by individuals
who are working close to the soil surface taking samples.
EPA's ESES uses the following odor classes:
High: A distinct odor, from naturally occurring soil
organic materials with a distinctive pungent, musty
odor, or sharp distinct odor from chemical con-
taminants.
Moderate to slight: A less distinct to faint odor, from
naturally occurring soil organic materials, or from
various odor-producing chemical contaminants.
None: No detectable odor by olfactory means.
3.3.3 Cation Exchange Capacity (CEC)
Cation exchange capacity, measured in milli-
equivalents per 100 grams (meq/100 g) orcentimoles per
kilogram (cmol/kg), is a measure of the soil's ability to ab-
sorb (and release) cations. It is an especially important
parameter at sites contaminated by heavy metals, be-
cause heavy metals will often replace exchangeable ions
such as sodium, potassium, calcium, and magnesium that
exist in natural soil. Measurement of CEC requires collec-
tion of samples for laboratory analysis. SCS (1971, Sec-
tion I9.7 and I9.8) describes relatively simple chemical
tests that can be carried out in the field to estimate ex-
changeable calcium and exchangeable sodium.
The measurement of extractable acidity, also
called exchangeable acidity or extractable hydrogen be-
cause it measures exchangeable ions that contribute to
soil acidity, is required for evaluation of soil corrosivity
(see Section 3.1.7e). Section 6H in SCS (1984) describes
specific procedures for determining extractable acidity in
the laboratory.
EPA's ESES uses the following CEC classes (ex-
pressed as meq/100 g soil): high (>20), medium (12-20),
3.3.4 Reaction (pH)
A variety of methods are available for field meas-
urement of pH (colorimetric, paper test strips, pH meter).
Specific procedures and instructions accompanying equip-
ment for the method used should be followed. For RCRA
sites, EPA Method 9045A Revision 1, November 1990,
should be used (U.S. EPA, 1986).
-------
Soil Survey Staff (1991) defines 13 pH classes for
soil as follows:
Class pH
Ultra acid (UA) <3.5
Extremely acid (EA) 3.5 - 4.5
Very strongly acid (VS) 4.5 - 5.0
Strongly acid (SA) 5.1 - 5.5
Medium acid (MA) 5.6 - 6.0
Slightly acid (SA) 6.1 - 6.5
Neutral (NA) 6.6 - 7.3
Mildly alkaline (MA) 7.4 - 7.8
Moderately alkaline (MO) 7.9 - 8.4
Strongly alkaline (SA) 8.5 - 9.0
Very strongly alkaline (VA) >9.0
3.3.5 Redox Potential (Eh)
Redox, or oxidation-reduction potential (Eh), is
measured in volts or millivolts (mV) as the potential dif-
ference in a solution between a working electrode and the
standard hydrogen electrode. Whether soil conditions are
oxidizing (aerobic) or reducing (anaerobic) will strongly af-
fect the types of microbiological activity and contaminant
transformation and degradation processes that may
occur. The mobility of many heavy metals varies with
oxidation state. In unsaturated soil, aerobic conditions
prevail, and measurement of Eh requires collection of soil
water samples using a suction lysimeter. The Eh of
saturated soil should be measured using ground-water
samples from properly purged monitoring wells.
EPA's ESES uses the following redox potential
classes: highly oxidized (>+400 mV), intermediate
(+400 to -100 mV), and highly reduced (<-100 mV).
3.3.6 Electrical Conductivity (Salinity)
In arid and semi-arid areas, soluble salts may ac-
cumulate in the soil and are called saline. The electrical
conductivity of a saturation extract is the standard
measure of salinity. Electrical conductivity is commonly
reported in units of decisiemens/meter or millimhos/cen-
timeter (1 dS/m = 1 mmho/cm). Electrical conductivity
SrBKSKSBiSK::*:^
Field Description and Analysis of Soils 85
-------
Field Description and Analysis of Soils 86
WSSSSSrSSSS^^
measurement or estimation is required for evaluation of
soil corrosivity (see Section 3.1.7e).
Salinity classes, based on electrical conductivity of a
saturation extract, are defined in EPA's ESES as follows:
Electrical Conductivity
Class (dS/m or mmho/cm)
Nonsaline 0-2
Slightly saline 2-4
Moderately saline 4-8
Very saline 8-16
Extremely saline >16
Note that Soil Survey Staff (1991) uses slightly different
terms for these classes.
SCS (1971, Section I9.6) describes a relatively
simple procedure for water extraction that can be used in
the field or a field laboratory for measuring approximate
soluble salt percentage. Accurate determination requires
laboratory preparation of soil samples. SCS (1984, Sec-
tion 8A) describes procedures for preparing a saturated
paste and obtaining a saturation extract for electrical con-
ductivity measurement. Measurement of the resistivity of
the saturated paste (SCS, 1984, Section 8E) is required
for evaluating soil corrosion potential for uncoated steel.
Richards (1954) and Richards et al. (1956)
describe procedures for testing saline soils in more detail
and provide charts and graphs for estimating total salt
from electrical conductivity measurements. Rhoades and
Oster (1986) describe more complex instrumentation for
collecting soil water using in situ samplers and measuring
soluble salts with in situ or remote monitors.
The electrical conductivity, also termed specific
conductance, of ground-water samples can be readily
measured in the field using a conductivity meter. Electrical
conductivity is a measure of the total dissolved solids in
the ground water and should not be confused with the soil
salinity test described above.
3.3.7 Clay Minerals
The following procedures can be used to identify
the dominant mineralogy of the clay size-fraction:
-------
Clay Mineral Test
1. Prepare a saturated solution of malachite green in
nitrobenzene to use as an indicator solution (follow
prescribed safety procedures when handling
nitrobenzene).
2. Add several drops of the indicator to a small
sample (1 g) of soil and observe color of wetted
soil as follows: blue or green-blue = kaolinite; yel-
low-red = montmorillonite; purple-red = illite.
Mica Shine Test
Rub a small clod of air-dried soil with a knife blade.
A shiny surface indicates a micaceous soil with
high plasticity.
EPA's ESES defines the following clay mineral
abundance classes (see Section 3.1.2 for estimation of
texture): abundant (>27 percent), moderate to slight (1
to 27 percent), none to negligible ( <1 percent).
3.3.5 Other Minerals
Concentrations of minerals may form in soil
horizons as a result of dissolution and precipitation
processes. These concentrations are described by SCS
according to (1) type, (2) amount or quantity, (3) size, (4)
shape, and (5) composition. The following are abbrevia-
tions of descriptors and criteria for describing concentra-
tions in soil:
Types
m — masses (soft, no clearly defined
boundaries)
n — nodules and concretions (hard, clearly
defined boundaries)
c — crystals (single or complex clusters)
srf — soft rock fragments (weakly cemented
or noncemented)
Amount/Quantity
f — few(<2%)
c — common (2-20%)
m — many
:y:::::::::y^^^
Field Description and Analysis of Soils 87
-------
Field Description and Analysis of Soils 88
Size
fine ( <2 mm)
medium (2-5 mm)
coarse (5-20 mm)
very coarse (20-76 mm)
extremely coarse (>76 mm)
Shape
rnd — rounded
cyl — cylindrical
pi — platelike
ir — irregular
fe — ferruginous
mn — manganiferous
sal — saline
Composition
calc — calcareous
arg — argillaceous
yp — gypsiferous
sil — siliceous
The following features and tests can be used to
identify major non-clay minerals in the field.
Carbonates (calcareous)
The presence of free calcium carbonate in soil can
be readily determined based on effervescence in dilute
hydrochloric acid. The test procedure is as follows:
1. Place 1 g of soil material (about the size of a
marble) in the well of a porcelain spot plate.
Thoroughly moisten the soil with a few drops of
deionized water; stir with a clean glass rod to
remove entrapped air.
2. Add three drops of dilute 10 percent (4 N) cold HCI
from a plastic squeeze bottle and immediately ob-
serve for effervescence of the treated sample
under a hand lens if possible.
3. If effervescence is observed, record intensity as
follows:
vse — very slightly effervescent (few bubbles seen)
sle— slightly effervescent (bubbles readily seen)
-------
ste—strongly effervescent (bubbles form low foam)
ve—violently effervescent (thick foam forms
quickly)
4. Repeat procedure on a second 1 -g sample.
Dolomite (calcium-magnesium carbonate) effer-
vesces slowly in cold acid unless the mineral is very finely
divided. If dolomite is suspected, place the sample in a
container and warm it for 15 minutes after covering it with
the acid solution.
Soluble Salts (saline, gypsiferous)
White incrustations that do not effervesce can be
separated and checked for water solubility and taste.
Chlorides, nitrates, and sulfates of sodium and potassium
are very water soluble. Chloride salts can be tested by
shaking a sample of soil in distilled water, placing about
10 mL of the supernatent solution (after the solids have
settled) in a test tube, and adding a few drops of 5 percent
sodium nitrate solution. Chlorides are indicated by the for-
mation of a thick, milky precipitate of silver chloride. The
formation of a heavy white precipitate after adding a 5 per-
cent barium chloride solution to a separate supernatent
sample indicates sulfate ions. SCS (1971, Section I9.6)
provides further details for these tests.
Crystals of gypsum, which may occur as a white in-
crustation in voids, are rhombic plates, laths, or some-
times fibers. Gypsum crystals can be scratched with the
fingernail, do not effervesce in acid, and are very slowly
soluble in water.
Gypsum Acetone Test. Place 1 part soil and 10
parts water (by weight) in a small bottle. Seal the bottle
and shake by hand at 15-minute intervals. Filter the ex-
tract through filter paper. Mix a 50-50 solution of the filtrate
and acetone. The formation of a milky precipitate indicates
the presence of gypsum. SCS (1971, Section I9.6)
describes a somewhat more complex semi-quantitative
test for gypsum using acetone which can be used in the
field.
Iron Oxides (ferruginous)
Goethite and hematite commonly occur as
segregated bodies in soils. Hematite is red; solid bodies,
such as nodules or sheets may be dark brown or almost
Field Description and Analysis of Soils 89
-------
Field Description and Analysis of Soils 90
black but have a red streak if rubbed on a rough porcelain
surface or a tough paper. Goethite bodies commonly are
red but may be yellow or brown and are generally softer
than hematite bodies. In an ignition test (see Section
3.1.3), hematite will show little color change; the duller
colors of goethite will brighten when it changes to
hematite. If gray, blue, or green materials turn red when
ignited, ferrous iron is present.
Manganese Oxide (manganiferous)
Black and very dark brown concretions and coat-
ings on cleavage planes are likely to be the manganese
oxide pyrolusite or a closely related mineral. It has a dark
brown streak and is very soft, producing the streak even
on paper. A procedure similar to the carbonate test using
a dilute (5 percent) solution of hydrogen peroxide instead
of HCI will result in the rapid evolution of small bubbles
with a usually rapid consumption of the hydrogen peroxide
if manganese oxides are present. See Section 3.3.1 for
further guidance in differentiating possible reactions with
organic matter.
SCS (1971, Section I7.2) discusses in more detail
the identification of minerals and mineral groups in the
field.
3.3.9 Fertility Potential
Soil fertility is the ability or status of a soil to supply
water and nutrients necessary for plant growth. Inherent
physical characteristics, such as soil structure and avail-
able water capacity, provide the basic elements of fertility
potential, and are not easily modified. The nutrient status
of a soil, on the other hand, can be improved by
fertilization.
Nutrient status is evaluated by analyzing samples
in the laboratory for nutrients essential for plant growth
such as nitrogen, potassium, and phosphorus. Soil reac-
tion (pH) is an important chemical parameter, because it
strongly influences the availability of nutrients.
The key physical parameters affecting fertility
potential are aeration and water availability, because plant
roots require both air and a ready supply of moisture for
optimum growth. These factors can be evaluated by ob-
serving soil properties such as soil texture (Section 3.1.2),
-------
depth to water table (Section 3.2.2), available water
capacity (Section 3.2.3), and soil drainage class (Section
3.2.4). Deep, well-drained soils with a high available water
capacity have the greatest fertility potential, provided
nutrient status is favorable. Shallow soils with low avail-
able water capacity have low fertility potential even if
nutrient status is favorable.
EPA's ESES defines the following soil fertility
potential or status classes:
High: Nutrients necessary for plant growth readily
supplied.
Moderate: Nutrients necessary for plant growth in
moderate supply.
Low: Nutrients necessary for plant growth in low
supply.
3.3.10 Soil Microbiota
Microorganisms in soil and ground water are now
recognized as being of major importance in affecting the
transformation and fate of many organic contaminants and
heavy metals. The study of soil microbiota from soil
samples requires carefully controlled laboratory condi-
tions. The major concern in the field is that procedures
used to collect soil samples do not allow contamination by
microorganisms from other sources. Soil samples must be
collected using sterilized tools and placed in sterilized con-
tainers. Samples of near-surface soils for microbiological
study should be taken from a soil pit. Scoops or trowels
used to collect samples from each soil horizon should go
through usual decontamination procedures. As a final
step, they should be heated with a blow torch and cooled
by being stuck into the horizon to be sampled before soil
material is dug out and placed into containers.
Samples for microbiological study taken from
greater depths where oxygen is low require special asep-
tic handling procedures to prevent oxygen from harming
anaerobic microorganisms. Leach et al. (1988) describes
in detail procedures for collecting such samples, which in-
volve preparing nitrogen-filled sampling containers in the
laboratory, and using a field sampling glove box that has
been purged with nitrogen gas to reduce the oxygen level
below detectable limits.
Field Description and Analysis of Soils 91
-------
Field Description and Analysis of Soils 92
EPA's ESES defines the following abundance
classes for soil microorganisms (as number per gram of
soil): abundant (>1,000,000), common (10,000-
1,000,000), few (100-10,000), none (<100).
3.4 Soil Contaminants
Visual identification of zones of soil contamination
is sometimes possible when the contaminants are in an
immiscible liquid phase or a solid phase. Iridescence of an
oily phase in water may indicate contamination from syn-
thetic organics. Solid phases should be described by color
and consistency (granular, tarry, etc.). Possible con-
tamination by heavy metals from artificial pigments is evi-
dent from bright colors. Toxic effects of contaminants on
surface vegetation also may be evident. In any event, the
presence of contaminants must be confirmed by
laboratory analysis of samples.
Organic vapor detectors are relatively simple in-
struments that are used to identify the presence of volatile
organics. The way in which readings are taken (distance
from sample being checked, location in borehole, length of
reading) should be recorded along with the readings them-
selves. Procedures should be performed consistently, and
any departures from usual procedures noted.
Increasingly sophisticated field equipment in
mobile laboratories is being used for onsite contaminant
analysis. Use of such equipment is not covered in this
guide. Ford et al. (1984) describe methods for monitoring
toxic gases and vapors with portable field instruments.
-------
Chapter 4
Soil Sampling
and
Quality Assurance
Sample design, sample location, equipment and sam-
pling methods, and quality assurance/quality control
(QA/QC) procedures should all be determined before
sampling begins and be recorded in the Soil Sampling and
Quality Assurance Plans for the site. Mason (1983) and
Barth et al. (1989) provide detailed guidance on statistical
aspects of sampling design and quality assurance. These
documents will outline the specific procedures that will be
required during field sampling.
This chapter has two purposes: (1) to provide
information that may be useful if unforeseen conditions
require modification of the procedures specified in the
sampling plan, and (2) to provide forms that may be useful
in carrying out QA/QC procedures.
4.1 Changes in Soil Sampling Procedures
Soil description, use of field analytical equipment,
and soil sampling should be conducted in a uniform and
consistent manner, following procedures specified in the
Soil Sampling and Quality Assurance Plans. If unforeseen
conditions arise at the site during the field investigation
and sampling that prevent carrying out the specified pro-
cedures, it may be necessary to develop alternative ap-
proaches at the site. Any such changes must be
documented and approved (see Section 4.2).
One situation requiring departure from specified
procedures is when soil conditions are unfavorable for the
equipment being used to collect samples. If this situation
occurs, the following tables may help identify alternative
sampling tools:
Soil Sampling and Quality Assurance 93
-------
So/7 Sampling and Quality Assurance 94
Table 4-1 summarizes information on applications
and limitations for use of 15 types of hand-
operated soil sampling devices.
Table 4-2 summarizes information on applications
and limitations for use of 10 common types of
power-driven tube samplers.
Appendix B provides the names and addresses of
24 manufacturers and distributors of manually
operated and power-driven soil sampling
equipment.
If the use of different sampling equipment requires
altering the standard sampling protocol, the new protocol
should be clearly specified. Appendices A.2 to A.4 provide
some general soil handling and sampling protocols that
can be used for guidance if revised protocols must be
developed at the site.
4.2 Quality Assurance/Quality Control
Any change in standard procedures for field collec-
tion of soil samples must be justified, described, and ap-
proved by the appropriate project personnel. Form 4-1
(Sample Alteration) can be used for this purpose. Multiple
copies of this form should be available for use.
Soil sampling personnel should be aware that their
work may be subject to a field audit to ensure that soil
sampling and other QA/QC procedures are being fol-
lowed. Form 4-2 contains a checklist of major items that
should be covered in a field audit. Field personnel would
do well to review this checklist periodically as a reminder
of areas in which they would be held accountable in the
event of a field audit.
The results of a field audit, or review of analytical
results, may identify problems areas requiring corrective
action. If the need for corrective action is identified during
a field audit, it should be implemented immediately.
Resampling may be required if analytical results fall out-
side the acceptable limits specified in the Quality As-
surance Plan. Form 4-3 (Soil Sample Corrective Action
Form) can be used to identify problem areas and specify
measures required to correct the problems. When resam-
pling is required, this form should be taken into the field
and the specified procedures carefully followed.
-------
Table 4-1. Summary of Hand-Held Soil Sampling Devices
Sampling
Device
Applications
Limitations
Spoons and
Scoops
Shovels and
Picks
Augers*
Screw Auger
Standard
Bucket Auger
Sand Bucket
Auger
Mud Bucket
Auger
Dutch Auger
In Situ Soil
Recovery
Auger
Eijkelcamp
Stoney Soil
Auger
Planer Auger
Surface soil
samples or the
sides of pits or
trenches
A wide variety
of soil conditions
Cohesive, soft, or
hard soils or
residue
General soil or
residue
Bit designed to
retain dry, loose,
or granular
material (silt, sand,
and gravel)
Bit and bucket
designed for wet
silt and clay soil
or residue
Designed specifically
for wet, fibrous, or
rooted soils
(marshes)
Collection of soil
samples in
reusable liners;
closed top reduces
contamination from
caving sidewalls
Stoney soils and
asphalt
Clean out and flatten
the bottom of
predrilled holes
Limited to relatively
shallow depths;
distributed samples
Limited to relatively
shallow depths
Will not retain dry,
loose, or granular,
material
May not retain dry,
loose, or granular
material
Difficult to advance
boring in cohesive
soils
Will not retain dry,
loose, or granular
material
Similar to
standard bucket
auger
(Continued)
Soil Sampling and Quality Assurance
95
-------
Soil Sampling and Quality Assurance
96
Table 4-1. (Continued)
Sampling
Device
Applications
Limitations
Tube Samplers**
Soil Probe
Thin-Walled
Tubes
Soil Recovery
Probe
Veihmeyer
Tube
Peat Sampler
Cohesive, soft
soils or residue;
representative
samples in soft to
medium cohesive
soils and silts
Cohesive, soft soils
or residue; special
tips for wet or
dry soils available
Similar to
thin-walled tube;
cores are collected
in reusable liners,
minimizing contact
with the air
Cohesive soils or
residue to depth of
3 meters
Wet, fibrous,
organic soils
Sampling depth
generally limited
to less than 1 meter
Similar to
Veihmeyer tube
Similar to
Veihmeyer tube
Difficult to drive into
dense or hard
material; will not
retain dry, loose, or
granular material;
may be difficult to
pull from ground
'Suitable for soils with limited coarse fragments; only the
stoney soil auger will work well in very gravelly soil.
"Not suitable for soils with coarse fragments.
Source: Adapted from Brown et al. (1991) and Rehm et al.
(1985).
-------
Table 4-2.
Samplers
Summary of Major Types of Power-Driven Tube
Sampling
Device
Applications
Limitations
Split Spoon
Sampler
Disturbed samples
from cohesive soils
Thin-Walled Samplers
Fixed-Piston Undisturbed
Sampler samples in cohesive
soils, silt, and sand
above or below
water table
Hydraulic
Piston
Sampler
(Osterberg)
Stationary
Piston
Sampler
Wireline Piston
Sampler
Free Piston
Sampler
Open Drive
Sampler
Similar to
fixed-piston
sampler
Undisturbed
samples in stiff,
cohesive soils;
representative
samples in soft to
medium cohesive
soils, silts, and
some sands
Undisturbed
samples in
cohesive soils and
noncohesive sands;
used with clamshell
device on
hollow-stem auger
Similar to stationary
piston sampler
Similar to stationary
piston sampler
Ineffective in
cohesionless sands;
not suitable for
collection of samples
for laboratory tests
requiring undisturbed
soil
Ineffective
in cohesionless
sands
Not possible to limit
the length of push or
to determine amount
of partial sampler
penetration during
push
In heaving sands only
one sample per
borehole can be
collected because
clamshell remains
open after sampling
Not suitable for
cohesionless soils
Not suitable for
cohesionless soils
(Continued)
:*B*:*:*s*B*s*^
Soil Sampling and Quality Assurance
97
-------
So/7 Sampling and Quality Assurance 98
X'XtoKW^
Table 4-2. (Continued)
Sampling
Device
Applications
Limitations
Pitcher Undisturbed samples
Sampler in hard, brittle,
cohesive soils and
cemented sands;
representative
samples in soft to
medium cohesive
soils, silts, and some
sands; variable
success with
cohesionless soils
Denison Undisturbed samples
Sampler in stiff to hard
cohesive soils,
cemented sands, and
soft rocks; variable
success with
cohesionless materials
Vicksburg Similar to Denison
Sampler sampler except takes
wider diameter samples
Frequently ineffective
in cohesionless soils
Not suitable for
undisturbed sampling
of loose, cohesionless
soils or soft
cohesive soils
Source: Adapted from Rehm et al. (1985) and Aller et al. (1989).
-------
Form 4-1. Sample Alteration Form
Project Name and Number:_
Material to Be Sampled:
Measurement Parameter:
Standard Procedure for Field Collection and Laboratory Analysis
(cite references):
Reason for Change in Field Procedure:
Variation for Field Procedure:
Special Equipment, Materials, or Personnel Required:
Initiator's Name: Date:
Project Approval Date:
Laboratory Approval: Date:
QA Officer/Reviewer: Date:
Sample Control Center: Date:
:*y*:*:*:::*:*&::S::^^
Soil Sampling and Quality Assurance 99
-------
So/7 Sampling and Quality Assurance 100
KoX'XvX'i'XW'WX':*:-:*:^^
Form 4-2. Field Audit Checklist
Records to Inspect
Chain-of-custody forms
Analytical analysis request forms
(if different from chain-of-custody forms)
Sample tags
Site description forms
Log books
Sampling Procedures to Inspect
Equipment
Techniques
Decontamination
Collection of duplicate and field blank samples
Security
Sample storage and transportation
Containers
Contaminated waste storage and disposal
Site description form entries
-------
Form 4-3. Sample Corrective Action Form
Project Name and Number:
Sample Data Involved:
Measurement Parameter(s):
Acceptable Data Range:
Problem Areas Requiring Corrective Action:
Measures Required to Correct Problems:
Means of Delecting Problems and Verifying Correction:
Initiator's Name: Date:
Project Approval: Date:
Laboratory Approval: Date:
QA Officer/Reviewer: Date:
Sample Control Center: Date:
Soil Sampling and Quality Assurance 101
-------
References 102
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Aller, L, et al. 1991. Handbook of Suggested Practices for
the Design and Installation of Ground-Water Monitoring
Wells. EPA/600/4-89/034. Available from ORD Publica-
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cinnati, OH, 45268, 221 pp. Also published in 1989 by
National Water Well Association, Dublin, OH, in its
NWWA/EPA series, 398 pp.
Barrett, J. et al. 1980. Procedures Recommended for
Overburden and Hydrologic Studies of Surface Mines.
GTR-INT-71. U.S. Forest Service, Intermountain Forest
and Experiment Station, Ogden, UT, 106 pp.
Barth, D.S., B.J. Mason, T.H. Starks, and K.W. Brown.
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Blake, G.R. and K.H. Hartge. 1986. Bulk Density. In:
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Agronomy, Madison, Wl, pp. 363-275.
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Analysis, Part 1, 2nd ed., A. Klute (ed.), Agronomy
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-------
Brown, K.W., R.P. Breckenridge, and R.C. Rope. 1991.
Soil Sampling Reference Field Methods. U.S. Fish and
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Guthrie, R.L. and J.E. Witty. 1982. New Designations for
Soil Horizons and Layers and the New Soil Survey
Manual. Soil Sci. Soc. Am. J. 46:443-444.
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(IDEM). 1988. Requirements for Describing Uncon-
solidated Deposits (draft revised 11/18/88). IDEM, In-
dianapolis, IN.
Johnson, W.M., J.E. McClelland, S.B. McCaleb, R. Ulrich,
W.G. Hoper, and T.B. Hutchings. 1960. Classification and
Description of Soil Pores. Soil Science 89:319-321.
Leach, L.E., F.P. Beck, J.T. Wilson, and D.H. Kampbell.
1988. Aseptic Subsurface Sampling Techniques for Hol-
low-Stem Auger Drilling. In: Proc. Third Nat. Outdoor Ac-
tion Conf. on Aquifer Restoration, Ground Water
Monitoring and Geophysical Methods. National Water Well
Association, Dublin, OH, pp. 31-51.
ycKyftK£^i^&wy&&y^y&sfc^
References 103
-------
References 104
Lynn, W.C., W.E. McKinzie, and R.B. Grossman. 1974.
Field Laboratory Tests for Characterization of Histosols.
In: Histosols: Their Characterization, Use and Classifica-
tion. Soil Science Society of America, Madison, Wl, pp.
11-20.
Mason, B.J. 1983. Preparation of Soil Sampling Protocol:
Techniques and Strategies. EPA-600/4-03-020 (NTIS
PB83-206979). Environmental Monitoring Systems
Laboratory, Las Vegas, NV, 89193-3478,102 pp.
O'Neal, A.M. 1952. A Key for Evaluating Soil Permeability
by Means of Certain Field Clues. Soil Sci. Soc. Am. Proc.
16:312-315.
Portland Cement Association. 1973. PCA Soil Primer. En-
gineering Bulletin EB007.045. Portland Cement Associa-
tion, Skokie, IL, 39 pp.
Rehm, B.W., T.R. Stolzenburg, and D.G. Nichols. 1985.
Field Measurement Methods for Hydrogeologic Investiga-
tions: A Critical Review of the Literature. EPRI EA-4301.
Electric Power Research Institute, Palo Alto, CA.
Rhoades, J.D. and J.D. Oster. 1986. Solute Content. In:
Methods of Soil Analysis, Part 1, 2nd ed., A. Klute (ed.),
Agronomy Monograph No. 9. American Society of
Agronomy, Madison, Wl, pp. 985-1006.
Richards, L.A. (ed.). 1954. Diagnosis and Improvement of
Saline and Alkali Soils. U.S. Department of Agriculture
Handbook No. 60,160 pp.
Richards, L.A., C.A. Bower, and M. Fireman. 1956. Tests
for Salinity and Sodium Status of Soil and Irrigation Water.
U.S. Department of Agriculture Circular 982.
Smith, G.D., F. Newhall, and L.H. Robinson. 1960. Soil-
Temperature Regimes—Their Characterization and Pre-
dictability. SCS-TP-144. USDA Soil Conservation Service,
14pp.
Soil Conservation Service (SCS). 1971. Handbook of Soil
Survey Investigations Procedures. SCS, Washington, DC,
98pp.
Soil Conservation Service (SCS). 1983. National Soils
Handbook. [Available for inspection in SCS County, Area,
or State Offices. A revised handbook was in preparation at
the time this pocket guide was completed.]
-------
Soil Conservation Service (SCS). 1984. Procedures for Col-
lecting Soil Samples and Methods of Analysis for Soil Survey.
Soil Survey Investigations Report No. 1. U.S. Government
Printing Office.
Soil Conservation Service (SCS). 1990. Elementary Soil
Engineering, Chapter 4. In: Engineering Field Manual for
Conservation Practices. SCS, Washington, DC.
Soil Science Society of America. 1987. Glossary of Soil
Science Terms. SSSA, Madison, Wisconsin.
Soil Survey Staff. 1975. Soil Taxonomy: A Basic System of Soil
Classification for Making and Interpreting Soil Surveys. U.S.
Department of Agriculture Agricultural Handbook No. 436.
Soil Survey Staff. 1990. Keys to Soil Taxonomy, 4th ed.
SMSS Technical Monograph No. 6. Dept. Crop and Soil
Environmental Sciences, Virginia Tech, Blacksburg, VA,
24061-0404, 422 pp ($12.00).
Soil Survey Staff. 1991. Examination and Description of Soils,
Chapter 3. In: Soil Survey Manual (new edition). Agricultural
Handbook No. 18. Soil Conservation Service, Washington,
DC. [Note that this supercedes the 1951 handbook by the
same title, and the 1962 supplement. This manual was at the
publisher at the time this pocket guide was completed.]
Taylor, S.A. and R.D. Jackson. 1986. Temperature. In:
Methods of Soil Analysis, Part 1, 2nd ed., A. Klute (ed.),
Agronomy Monograph No. 9. American Society of
Agronomy, Madison, Wl, pp. 927-940.
U.S. Environmental Protection Agency (EPA). 1986. Test
Methods for Evaluating Solid Waste. SW-846 (NTIS
PB88-239223 and PB89-148076).
van Ee, J.J., L.J. Blume, and T.H. Starks. 1990. A Ration-
ale for the Assessment of Errors in the Sampling of Soils.
EPA/600/4-90/013. Environmental Monitoring Systems
Laboratory, Las Vegas, NV, 57 pp.
Vogel, W.G. 1987. A Manual for Training Reclamation In-
spectors in the Fundamentals of Soils and Revegetation.
Soil and Water Conservation Society, Ankeny, IA, 178 pp.
Witty, J.E. and E.G. Knox. 1989. Identification, Role in Soil
Taxonomy, and Worldwide Distribution of Fragipans. In:
Fragipans: Their Occurrence, Classification, and Genesis,
N.E. Smeck and E.J. Ciolkosz (eds.), SSSA Sp. Pub. No.
24. Soil Science Society of America, Madison, Wl, pp. 1-9.
References 105
-------
Description of Soil Cores 106
Appendix A.1
General Protocol for
Description of Soil Cores
Careful description of soil conditions at sampling loca-
tions can provide valuable information for interpreting
soil analyses. Soil cores, which provide relatively undis-
turbed cross sections of the soil, are best for soil descrip-
tion. A few major features like texture, color (but not
accurate description of mottling or variations in color), and
potential zones of contamination can be described from
auger samples, but not much more.
At the outset, it should be decided whether soil
descriptions will be made from the actual samples to be
analyzed or from separate cores taken at the site.
Describing actual samples has the advantage of allowing
direct correlation of analyses with observed features, but
will result in longer exposure of the sample to the air
before it is placed in the sample container. This may not
be desirable, even for samples taken for analysis of semi-
volatiles and metals. Table 1-1 contains an abbreviated
list of suggested features to be described from soil
samples.
Taking separate cores allows more leisurely and
detailed observation of soil features. The soil can also be
handled as necessary without concern about affecting its
integrity for analyses. When equipment is being used just
to describe soil features, decontamination procedures
between locations also may be less rigorous, provided
that there is no danger that contaminants with very low
detection limits could be spread to uncontaminated areas.
The upper 1.5 to 2 meters, which have been af-
fected by soil weathering processes, should receive the
most careful attention for description because this is
where the most complex features are likely to be en-
-------
countered. Weathering may extend below 2 m in older
landscapes formed in temperate to humid climates. Below
the zone of weathering, the more simplified descriptions
typical of geologic drill logs are appropriate. General pro-
cedures for describing both types of cores are outlined
below.
Soil Cores (weathered zone, usually 1.5 to 2 m)
1. Near the location where the core is to be taken,
spread a plastic sheet about 30 cm wide and 2
meters long on the ground, and place on it a fully
extended carpenters rule or range pole marked
with gradations that match the depth increments on
the tube sampler to be used (i.e., in./ft or
cm/meter).
2. Clear any litter away from the ground surface and
take the first core. An open tube sampler that ex-
poses most of the core when it is pulled out is
easiest to use for this purpose. Remove the core
and place it on the sheet at the zero end of the
rule. If the presence of volatile contaminants is
suspected, take the reading of the core as soon as
it is brought to the surface with field instrumenta-
tion (photoionization or flame ionization detector).
Also take a reading near the top of the core hole
and record the measurements.
3. Repeat coring process trying to take equal incre-
ments (12-in. increments are usually possible in
the upper 2 or 3 ft; 6-in. increments when the soil is
very dry and in deeper, denser horizons), placing
each core on the sheet at the appropriate depth in-
terval until the desired maximum depth has been
reached. If the presence of volatile contaminants is
suspected, readings with field instruments should
be made of each core as soon as it is brought to
the surface, and near the top of the hole before
taking the next increment.
4. If penetration is difficult in very dense or very dry
soils, a weighted plastic mallet can be used to
drive a sampler with a T-handle into the ground. If
such conditions are typical, consider using
samplers with specially designed weighted drivers.
Description of Soil Cores 107
-------
Description of Soil Cores 108
5. !f rock fragments prevent further penetration of the
tube sampler before the desired depth has been
obtained, an auger (screw or bucket) can be used.
If the diameter of the auger is larger than that of
the tube sampler (usually the case), discard the
soil material brought up by the auger for the depth
increments already sampled.
6. When the depth of interest is reached, pull up the
auger at regular intervals and place soil by the rule
on the sheet at the appropriate depth location. To
prevent mixing of loose soil material from different
depth increments, place material at chosen incre-
ments (e.g., 12 in.) on opposite sides of the rule.
7. Once the complete soil is laid out on the sheet,
visually examine the cores and place nails or some
other kind of marker at the places where color
changes indicate transitions between horizons.
8. Carefully split the cores. A knife may be used to
create a shallow groove, but the core should not be
sliced all the way through because this will disturb
structural features. Place one-half with the interior
side facing up, and the other half with the interior
side facing down (exposing the surface that was
used for the initial visual inspection).
9. Visually examine the interior face of the cores for
transitions in structural units, texture, or other fea-
tures. Adjust the locations of initially placed horizon
markers on the sheet, if appropriate, and add addi-
tional markers for subhorizons, if required.
10. Describe each soil horizon using Form 3-1. Refer
to the appropriate sections of Chapter 3 for proce-
dures and abbreviated codes for descriptors of soil
parameters.
Cores below Weathered Zone (usually 1.5 to 2 m)
Cores from greater depths can be described using
essentially the same procedures as described above, ex-
cept that the greater length requires placement of cores in
holders where depth increments are side-by-side rather
than end-on-end, and that generally fewer features are
described. Most drillers and consultants have their own
drill log forms. At a minimum, the following information
-------
should be recorded when describing cores below the
weathering horizon:
1. Type of sample (split spoon, shelby tube, etc.)
2. Thickness driven/thickness recovered
3. Blow count (per 6 in.), if driven
4. Depth interval
Descriptions of depth intervals tend to be more ab-
breviated than near-surface soil profile descriptions and
apply to regular depth intervals rather than transitions
between horizons (although such transitions should be
noted and described). Features should be described in a
consistent sequence. The following features, when
present, should be described:
1. Texture (USDA and Unified estimated textures,
coarse fragments)
2. Sorting and roundness
3. Moisture condition (moist, wet, dry, presence of
water table)
4. Color and mottling
5. Consistency (rupture resistance, cementation)
6. Secondary porosity features
7. Sedimentary structures
8. Presence of organic matter
9. Effervescence in dilute, 10 percent cold HCI (cal-
careous parent material)
10. Visible presence of synthetic chemicals (oil,
gasoline, solvents)
11. Reading from field instrumentation (photoionization
or flame ionization detector)
Description of Soil Cores 109
-------
So/7 Sample Handling and Preparation 110
Appendix A.2
General Protocol for Soil
Sample Handling and
Preparation
If questions arise in the field concerning sample handling
and preparation procedures as specified in the Soil Sam-
pling Plan for the site, this general protocol can be used.
Any departures from procedures contained in the site Soil
Sampling Plan should be documented and justified (see
Form 4-1). The procedures described here generally apply
to any type of soil sampling. They have been compiled
primarily from procedures described in Brown et al.
(1991). Specific procedures for different types of sampling
tools are described in Appendices A.3 and A.4.
A.2.1 Soil Sample Collection Procedures for
Volatiles
1. Tube samplers are preferred when collecting for
volatiles. Augers should be used only if soil condi-
tions make collection of undisturbed cores impos-
sible. Soil recovery probes and augers, with
dedicated or reusable liners (see Table 4-1), will
minimize contact of the sample with the
atmosphere.
2. Place the first adequate grab sample, maintaining
and handling the sample in as undisturbed a state
as possible, in 40-mL septum vials or in a 1 -L glass
wide mouth bottle with a Teflon®-lined cap. Do not
mix or sieve soil samples.
3. Ensure the 40-mL containers are filled to the top to
minimize volatile loss. Secure the cap tightly.
4. Examine the hole from which the sample was
taken with an organic vapor instrument after each
-------
sample increment. Record any instrument
readings.
5. Label and tag sample containers, and record ap-
propriate data on soil sample data sheets (depth,
location, etc.).
6. Place glass sample containers in scalable plastic
bags, if required, and place containers in iced ship-
ping container. Samples should be cooled to 4°C
as soon as possible.
7. Complete chain-of-custody forms and ship as soon
as possible to minimize sample holding time (see
Table A.1 for maximum holding times for various
constituents).
8. Follow required decontamination and disposal pro-
cedures (see A.2.3).
A.2.2 Soil Sample Collection and Mixing
„ Procedures for Semivolatiles and
Metals
1. Collect samples.
2. If required, composite the grab samples, or use
discrete grab samples.
3. If possible, screen the soils in the field through a
precleaned O-mesh (No. 10, 2 mm) stainless steel
screen for semivolatiles, or Teflon®-lined screen
for metals (some metals in stainless steel could
contaminate the sample).
4. Mix the sample in a stainless steel, aluminum (not
suitable when testing for Al), or glass mixing con-
tainer using the appropriate tool (stainless steel
spoon, trowel, or pestle).
5. After thorough mixing, place the sample in the mid-
dle of a relatively inexpensive 1-m square piece of
suitable plastic, canvas, or rubber sheeting.
6. Roll the sample backward and forward on the
sheet while alternately lifting and releasing op-
posite sides or corners of the sheet.
7. After thorough mixing, spread the soil out evenly
on the sheet with a stainless steel spoon, trowel,
spatula, or large knife.
Soil Sample Handling and Preparation 111
-------
So/7 Sample Handling and Preparation 112
8. Take sample container and check that a Teflon®
liner is present in the cap, if required (see Table
A-1 for recommended sample containers for dif-
ferent contaminants).
9. Divide the sample into quarters, and take samples
from each quarter in a consecutive manner until
appropriate sampling volume is collected for each
required container. Separate sample containers
would be required for semivolatiles, metals, dupli-
cate samples, triplicate samples (split), and spiked
samples.
10. Secure the cap tightly. The chemical preservation
of solids is generally not recommended.
11. Label and tag sample containers, and record ap-
propriate data on soil sample data sheets (depth,
location, other observations).
12. Place glass sample containers in scalable plastic
bags, if required, and place containers in an iced
shipping container. Samples should be cooled to
4°C as soon as possible.
13. Complete chain-of-custody forms and ship as soon
as possible to minimize sample holding time (see
Table A-1 for maximum holding times for various
constituents). Scheduled arrival time at the analyti-
cal laboratory srfould give as much holding time as
possible for scheduling of sample analyses.
14. Follow required decontamination and disposal pro-
cedures (see A.2.3).
A.2.3 Equipment Decontamination/Disposal
Decontamination procedures may vary from state
to state and site to site. Detailed procedures should be
specified in the Soil Sampling Plan. A very general proce-
dure is outlined here:
1. Any disposable solid contaminated equipment
(plastic sheets, screens, etc.) should be placed in
plastic bags for temporary storage and sealed in
metal barrels for final transport/disposal.
2. Reusable equipment should be washed and rinsed
using decontamination procedures specified in the
Soil Sampling Plan.
-------
3. Collect swipes and decontamination blanks, if
required, to evaluate the possibility of
cross-contamination.
A.2.4 Air Drying
Samples collected for chemical analysis in the
laboratory do not normally need to be air dried. However,
air drying may be desired in the field for evaluation of soil
physical and hydrologic properties. In some instances, air
drying of contaminated samples involving semivolatiles
and metals may be desired before sending samples to the
analytical laboratory.
1. Weigh sample and record weight if percent mois-
ture is required.
2. Spread out the soil sample on a stainless steel
sheet and allow to air dry. This may take 3 days or
more. If samples are to be analyzed for possible
contaminants, samples should be placed so as to
prevent possible cross-contamination. If they are to
be analyzed for microbiological activity, samples
should be placed in containers through which fil-
tered air can be passed.
3. When dry, weigh and record weight if percent
moisture is required.
4. Break up soil aggregates and pull apart vegetation
and root mat, if present. Weigh nonsoil vegetation
fraction, and archive or discard, as required.
5. Remove large rocks and weigh. Archive for pos-
sible analysis.
6. Crush the entire soil sample with a rolling pin,
stainless steel spoon, or some similar tool. Blend
with stainless steel spoon for 30 minutes.
7. Sieve through an O-mesh (No. 10, 2 mm) screen.
Any type of screen is acceptable, if soils are not
contaminated. Use disposable stainless steel
(semivolatile contamination) or Teflon® (metal con-
tamination) if soil samples are contaminated and
the chemical integrity of the sample must be
maintained.
8. Spread out the sample, mark off quarters, and take
sample from each quarter in a consecutive manner
until appropriate sample volume is collected.
Soil Sample Handling and Preparation 113
-------
Soil Sample Handling and Preparation 114
x*K*:*K'>:*:*X'K'X*K*:'Xw
Archive remaining sample for future analysis, if
needed.
9. When ready for shipment to the analytical
laboratory, shake the sample to mix thoroughly.
10. Follow required decontamination and disposal
procedures (see A.2.3).
Table A-1. EPA Recommended Sampling Containers,
Preservation Requirements, and Holding Times for Soil
Samples
Contaminant
Acidity
Alkalinity
Ammonia
Sulfate
Sulfide
Sulfite
Nitrate
Nitrate-Nitrite
Nitrite
Oil and Grease
Organic Carbon
Metals
Chromium VI
Mercury
Other Metals
Cyanide
Organic Compounds
Extractables
Including Phthalates,
Nitrosamines, Organo-
chlorine Pesticides,
PCBs, Nitroaromatics,
Isophorone, Polynuclear
Aromatic Hydrocarbons,
Haloethers, Chlorinated
Hydrocarbons, and
TCDD
Container*
Preservation**
P,G
P,G
P,G
P,G
P,G
P,G
P,G
P,G
P.G
G
P.G
P,G
P.G
P,G
P,G
G, Teflon®-
lined cap
Holding
Time***
1 4 days
1 4 days
28 days
28 days
28 days
48 hours
48 hours
28 days
48 hours
28 days
28 days
48 hours
28 days
6 months
28 days
7 days until
extraction
30 days after
extraction
(Continued)
-------
Table A-1. (Continued)
Contaminant
Container*
Preservation*
Holding
Time***
Extractables (Phenols)
Purgables
Halocarbons and
Aromatics
Acrolein and
Acrylonitrate
Orthophosphate
Pesticides
Phenols
Phosphorus
Phosphorus, Total
Chlorinated Organic
Compounds
G, Teflon®-
lined cap
G, Teflon®-
lined septum
G, Teflon®-
lined septum
P,G
G, Teflon®-
lined cap
G
G
P,G
G, Teflon®-
lined cap
7 days until
extraction
30 days after
extraction
14 days
3 days
48 hours
7 days until
extraction
30 days after
extraction
28 days
48 hours
28 days
7 days
*P = polyethylene, G = glass.
"All samples cooled to 4°C. Sample preservation should be per-
formed immediately upon sample collection. For composite
samples, each aliquot should be preserved at the time of collec-
tion. When impossible to preserve each aliquot, then samples
may be preserved by maintaining 4°C until compositing and
sample splitting is completed.
'"Samples should be analyzed as soon as possible after collec-
tion. The times listed are the maximum times that samples may
be held before analysis and still be considered valid. Samples
may be held for longer periods only if the analytical laboratory
has data on file to show that the specific types of samples under
study are stable for the longer time.
Source: Barth et al., (1989); for additional information, see
Mason (1983).
So/7 Sample Handling and Preparation
115
-------
So/7 Sampling with a Spade and Scoop 116
:*K*:!:!:::::':*H*:*:W^^^
Appendix A.3
General Protocol for Soil
Sampling with a Spade
and Scoop
The simplest and most direct method of collecting
soil samples for subsequent analysis is with a spade and
scoop. A normal lawn or garden spade can be used to
remove the top cover of soil to the required depth, and
then a smaller stainless steel scoop can be used to collect
the sample.
This method can be used in most soil types, but is
limited to sampling the near surface. Samples from depths
greater than 50 cm become extremely labor intensive in
most soil types. Very accurate, representative samples
can be collected with this procedure depending on the
care and precision demonstrated by the sampler. A flat,
pointed mason trowel can be used to cut a block of soil
when relatively undisturbed samples are desired. A stain-
less steel scoop or lab spoon will suffice in most other ap-
plications. Chrome-plating on instruments, common with
garden implements such as potting trowels, should be
avoided.
Procedure (drawn from Ford et al., 1984)
1. Clear the area to be sampled of any surface debris
(twigs, rocks, litter). It may be advisable to remove
the first 8 to 15 cm of surface soil for an area ap-
proximately 15 cm in radius around the drilling
location to prevent near-surface soil particles from
falling down the hole.
2. Carefully remove the top layer of soil to the desired
sample depth with a precleaned spade.
-------
3. Using a precleaned stainless steel scoop or trowel,
remove and discard a thin layer of soil from the
area which came in contact with the shovel.
4. Collect and handle sample using procedures
described in A.2.1 (Soil Sample Collection Proce-
dures for Volatiles) and A.2.2 (Soil Sample Collec-
tion and Mixing Procedures for Semivolatiles and
Metals).
So/7 Sampling with a Spade and Scoop 117
-------
So/7 Sampling with Augers and Thin-Walled Tube Samplers 118
KW
Appendix A.4
General Protocol for
Soil Sampling with
Augers and Thin-Walled
Tube Samplers
Hand-held augers and thin-walled tube samplers can be
used separately or in combination. Where rocky soils
do not limit the use of tube samplers, a combination of
augers to remove soil material to the depth of interest and
tube samplers for actual sample collection allows the most
precise control of sample collection. Depths to 2 meters
can be readily sampled and up to 6 meters where condi-
tions are favorable. Tables 4-1 and 4-2 provide informa-
tion on the advantages and disadvantages of different
types of augers and tube samplers for sampling under dif-
ferent soil conditions.
The recently developed in situ soil recovery auger
and probe allow collection of samples in dedicated or
reusable liners that reduce cross-contamination of
samples and minimize contact with the atmosphere (see
Table 4-1 and Appendix B).
Specific sampling tools may require slightly dif-
ferent handling methods. For example, if sampling devices
and drill rod extensions do not have quick connect fittings,
crescent or pipe wrenches may be required to change
equipment configurations. The procedure described below
is for hand-held equipment. Procedures for power-driven
augers or tube samplers are essentially the same (drawn
from Ford et al., 1984, and Brown et al., 1991).
1. Attach the auger bit to a drill rod extension and fur-
ther attach the "T" handle to the drill rod.
2. Clear the area to be sampled of any surface debris
(twigs, rocks, litter). It may be advisable to remove
-------
the first 8 to 15 cm of surface soil for an area ap-
proximately 15 cm in radius around the drilling
location to prevent near-surface soil particles from
falling down the hole.
3. Begin drilling, periodically removing accumulated
soils. This prevents accidentally brushing loose
material back down the borehole when removing
the auger or adding drill rods.
4. After reaching the desired depth, slowly and care-
fully remove auger from boring. When sampling
directly from auger, collect sample after auger is
removed from boring. Discard the upper portion of
the sample, which may contain soil that has fallen
to the bottom of the hole from the sidewalls.
Proceed to sample handling and mixing proce-
dures (see A.2.1 and A.2.2).
5. If taking a core sample, remove auger tip from drill
rods and replace with a precleaned thin-walled
tube sampler. Install proper cutting tip. (An optional
step is to first replace the auger tip with a planer
auger to clean out and flatten the bottom of the
hole before using the thin-walled tube sampler.)
6. Carefully lower corer down borehole. Gradually
force corer into soil. Care should be taken to avoid
scraping the borehole sides. Hammering of the drill
rods to facilitate coring should be avoided, as the
vibrations may cause the bore walls to collapse.
7. Remove corer and unscrew drill rods.
8. Remove core from device (this may require remov-
ing cutting tip) and discard top of core (ap-
proximately 2.5 cm), to eliminate soil that may
have fallen down from higher horizons.
9. Handle sample using procedures described in
A.2.1 andA.2.2.
So/7 Sampling with Augers and Thin-Walled Tube Samplers 119
-------
Manufacturers and Distributors of Soil Sampling Equipment 12°
W&S8$!$^^
Appendix B
xmv&»Z'»&;&s*x»Kmi&»x>z!:
Manufacturers and
Distributors of Soil
Sampling Equipment
Table B-1. Manufacturers and Distributors of Soil
Sampling Equipment (Compiled from Barrett et al., 1980;
Ford et al., 1984; Rehm et al., 1985; SCS, 1983)
Supplier
Types of Samplers
Acker Drill Company
P.O. Box 830
Scranton, PA 18501
Art's Manufacturing and
Supply (AMS)
105 Harrison
American Falls, ID 83211
1/800/635-7330
Boyle Brothers
P.O. Box 25068
1624 Pioneer Road
Salt Lake City, UT 84125
Carl's Machine Shop and
Supply Co.
1202 ^ainSt.
Woodward, OK 73801
Mining Products Division
Christensen Diamond Products
Company
1937 S. 300 West
Salt Lake City, UT 84115
Power-driven samplers
Manual samplers
In situ soil recovery
auger and probe
Planer auger
Power-driven samplers
Power-driven samplers
Power-driven samplers
(Continued)
-------
Table B-1. (Continued)
Supplier
Types of Samplers
Clements Associates, Inc.
RR1 Box 186
Newton, IA 50208
515/792-8285
Forestry Suppliers
P.O. Box 8397
Jackson, MS 39284-8397
Gidding Machine Company
401 Pine Street
P.O. Box 406
Fort Collins, CO 80521
Hansen Machine Works
1628 North C Street
Sacramento, CA 95814
Joy Manufacturing Company
Montgomery Industrial Center
Montgomeryville, PA 19936
Longyear Company
925 Delaware Street, SE
Minneapolis, MN 55414
Mobile Drilling Company
3807 Madison Ave.
Indianapolis, IN 46227
Oakfield Apparatus Company
P.O. Box 65
Oakfield, Wl 53065
Odgers Drilling, Inc.
Ice Lake Road
Iron River, Ml 49935
Penndrill Manufacturing Div.
Pennsylvania Drilling Co.
P.O. Box 8562
Pittsburgh, PA 15220
Manual samplers
Manual samplers
Clinometer
Power-driven samplers
Veihmeyer probe
Power-driven samplers
Power-driven samplers
Power-driven samplers
Manual samplers
Power-driven samplers
Power-driven samplers
(Continued)
Manufacturers and Distributors of Soil Sampling Equipment
121
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Manufacturers and Distributors of Soil Sampling Equipment 122
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Table B-1. (Continued)
Supplier
Types of Samplers
Pitcher Drilling Company
75 Allemany Street
Daly City, CA 94014
Reed Tool Company
105 Allen Street
P.O. Box 3641
San Angelo, TX 76901
Reese Sale Company
P.O. Box 645
2301 Gibson St.
Bakersfield, CA 93302
Sauze Technical Products
Corp.
345 Cornelia St.
Plattsburgh, NY 12901
518/561-6440
Service Truck Body Shop
1259 Murray
Alexandria, LA 71301
Soilmoisture Equipment Corp.
P.O. Box 30025
Santa Barbara, CA 93105
805/964-3525
Soiltest, Inc.
P.O. Box 931
2205 Lee Street
Evanston, IL 60202
312/869-5500
Sprague and Henwood, Inc.
221 West Olive Street
Scranton, PA 18501
Wildco
301 Cass Street
Sag in aw, Ml 48602
517/799-8100
Power-driven samplers
Power-driven samplers
Power-driven samplers
Eijkelcamp stoney soil
auger
Manual samplers
Manual samplers
Power-driven samplers
Penetrometer
Selves
Power-driven samplers
Manual samplers
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