United States
            Environmental Protection
            Agency
            Office of Research and
            Development
            Washington, DC 20460
EPA/600/4-91/029
March 1992
vvEPA
Guide to Site and Soil
Description for Hazardous
Waste Site Characterization
            Volume 1: Metals

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                                     EPA/600/4-91/029
                                     March 1992
           GUIDE TO SITE AND SOIL DESCRIPTION
      FOR HAZARDOUS WASTE SITE CHARACTERIZATION
                    VOLUME 1: METALS
                            by
                       Roy E. Cameron
           Lockheed Engineering & Sciences Company
                 Environmental Programs Office
                    Las Vegas, NV 89119

                  Contract Number 68-CO-0049
                        Project Officer

                      J. Jeffrey van Ee
             Exposure Assessment Research Division
      Environmental Monitoring Systems Laboratory - Las Vegas
                  Las Vegas,  NV 89193-347^^^^ ^^ Agency

                                     ?7^ifjS ••;'.'•'  'V:;U2Ui Floor
                                     Chicago, is.  eoeo-:-.-.^
ENVIRONMENTAL MONITORING SYSTEMS LABORATORY - LAS VEGAS
           OFFICE OF RESEARCH AND DEVELOPMENT
          U.S. ENVIRONMENTAL PROTECTION AGENCY
                  LAS VEGAS, NV  89193-3478

                                           ?^A) Printed on Recycled Paper

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                                         NOTICE

The information in this document has been funded wholly (or in part) by the U.S. Environmental
Protection Agency under contract number 68-CO-0049 to Lockheed Engineering & Sciences Company.
It has been subjected to the Agency's peer and administrative review, and it has been approved for
publication as an EPA document.

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                                          ABSTRACT

This guide is intended to assist field personnel who must identify, describe, and interpret the site and
soil characteristics of hazardous waste sites where metals contamination is suspected or known. The
guide is directed to regional project managers, on-scene coordinators and others who may need to
apply the  basic principles of soil science to a waste site environment but may not have a thorough
knowledge of basic information and protocols for describing and characterizing contaminated soils,
particularly those contaminated with metal species. The approach presented, including the
knowledge frames of an expert system, will be unfamiliar to most site investigators. These frames are
also the basis for components of the Environmental Sampling Expert System (ESES).

Site and soil characterization data are important components in developing the sampling plan for both
field and laboratory, in preparing for field  reconnaissance, and in conducting sampling and analysis
activities.  Consequently, it is important to consider and synthesize data from all available sources in
developing site and soil descriptions.  It is also important to design the site and soil characterization
process to complement the intended use of the data (e.g., site characterization, health and safety, risk
assessment, evaluation of remedial alternatives, and monitoring during remedial action).  This guide
provides a general discussion  (Section 2) of the elements of a background review and an on-site
examination of site and soil characteristics essential to meeting the needs of these different data uses.
This general discussion is followed by a catalogue of individual site (Section 3) and soil (Section 4)
characteristics (e.g., climate  and weather, texture and structure, hydraulic conductivity, slope, soil
microorganisms) that could be investigated during site characterization. For each entry, the guide
describes  possible conditions of the characteristic (e.g., high, moderate, or low; prominent,  distinct, or
faint) and  methods for assigning these conditions. References that provide more  detailed information
are given for each characteristic. Extensive definitions are provided for describing contaminated sites
and soils.

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                                          CONTENTS


Notice  	 ii

Abstract	iii

Tables	vi

Figures  	  vii

Abbreviations and Symbols  	viii

1.0     Introduction	   1-1

2.0     Collection and Use of Site and Soil Characterization Data	   2-1

        2.1     Site Background Review  	   2-1
        2.2     Site Description	   2-2
        2.3     Soil Description	   2-5
        2.4     Intended Use of the Data	2-11

3.0     Site Knowledge Frames	   3-1

               Nature of Heavy Metal Soil Pollutants	   3-2
               Climate and Weather	3-21
               Slope  	3-24
               Surface Erosion and Erodibility  	3-26
               Surface Pollution Situations	3-29
               Surface Runoff	3-31
               Vegetation	3-33
               Wind Speed and Direction	3-36

4.0     Soil Knowledge Frames  	   4-1

               Bulk Density  	   4-2
               Cation Exchange Capacity	   4-4
               Clay Minerals	   4-7
               Color	4-11
               Compaction	4-16
               Consistency	4-18
               Corrosivity (Corrosion  Potential)	4-20
               Electrical Conductivity 	4-22
               Fertility Potential  	4-25
               Horizons	4-27
               Hydraulic Conductivity	4-31
               Infiltration  and Percolation 	4-38

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              Mesofauna and Macrofauna	4-41
              Microbiota	4-44
              Moisture (Water) Conditions	4-49
              Odor	4-52
              Organic Matter and Litter	4-54
              Porosity	4-57
              Reaction (pH) 	4-60
              Redox Potential (Eh) 	4-63
              Roots 	4-67
              Structure Grades	4-70
              Surface Features	4-74
              Temperature  	4-76
              Temperature Regimes	4-78
              Texture Classes	4-82

5.0    References Cited	  5-1

       Appendices

       A.     Sources of Site Characterization Data  	  A-1
       B.     General Definitions for Site and Soil Characterization Terms	  B-1
       C.     Example of Soil Description Form	  C-1
       D.     Methods for Determination of Site and Soil Parameters  	  D-1

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                                          TABLES

Number                                                                                 Page

 2-1          Comparison of ASTM, USCS and USDA Soil Textural
              Classification Systems	2-7

 2-2          Site and Soil Characterization Parameters and their Determination	2-15

 3-1          Concentration of Metals and Nonmetals (Trace Elements) Considered
              to be Phytotoxically Excessive Levels in Surface Soils and Various
              Plants in ppm Air Dry Weight (10,000 ppm = 1.0%)	3-18

 3-2          Behavior of Metals During Various Weathering Processes	3-19

 3-3          EPA Toxicity Levels of Extracted Hazardous Wastes Samples
              Containing Metals, Metalloids and Organics	3-20

 3-4          Definitions of Slope Classes	3-25

 4-1          Terms for Describing Soil Mottles	4-14

 4-2          Saturated Hydraulic Conductivity Class Limits
              in Equivalent Units	4-35

 4-3          Size Classes of Soil Structure 	4-73

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                                         FIGURES

Number                                                                               Page

 1-1          ESES-SM Module Interpendency Diagram 	1-3

 2-1          Soil Texture Triangle  	2-6

 2-2          Applicability of Guide to Site and Soil Description
              and Field Pocket Guide to Site Characterization Phases	2-14

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                             ABBREVIATIONS AND SYMBOLS
ASTM        American Society for Testing and Materials
CERCLA      Comprehensive Environmental Response Compensation and Liability Act, 1980
             (Superfund)
CFR         Code of Federal Regulations
DDRP        Direct/Delayed Response Project
DQO         Data Quality Objective
EIS          Environmental Impact Statement
EMSL-LV      Environmental Monitoring Systems Laboratory - Las Vegas
EP           Extraction Procedure - EPA
EPA         U.S. Environmental Protection Agency
ESES        Environmental Sampling Expert System
FIT          Field Investigation Team
HSWA        Hazardous and Solid Waste Amendments to RCRA of 1984
LESC        Lockheed Engineering & Sciences Company
NEIC         National Enforcement Investigations Center
NOAA        National Oceanic and Atmospheric Administration
NPDS        National Pollution Discharge Information System
OSC         On-Scene Coordinator
OSHA        Occupational Safety and Health Administration
PRP         Potentially Responsible Party
RCRA        Resource Conservation and Recovery Act, 1976; Final Amendment, 1988
RD/RA        Remedial Design/Remedial Action
RD           Remedial Design
RI/FS         Remedial Investigation/Feasibility Study
RPM         Remedial Project  Manager
RPO         Regional Project (Program) Officer
RRT         Regional Response Team
SARA        Superfund Amendment and Reauthorization Act, 1986
SCS         U.S. Department of Agriculture, Soil Conservation Service
SM          Site Manager
SSS         Soil Survey Staff
SWDA        Soil Waste Disposal Act
USCS        Unified Soil Classification System
USDA        U.S. Department of Agriculture
USGS        U.S. Geological Survey
UST         Underground Storage Tank

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                                        SECTION 1.0

                                       INTRODUCTION
This guide or knowledge book is intended to assist personnel to identify, describe, and interpret the
site and soil characteristics of hazardous waste sites, particularly where metals contamination of soils
is suspected or known. It is directed toward both management and field personnel: Regional Project
(Program) Officer (RPO), Remedial Project Manager (RPM), Site Manager (SM), On-Scene Coordinator
(OSC), Field Investigation Team  (FIT), Regional Response Team (RRT), Initial Entry Party fleam), Work
Party, Environmental Response Team, the potentially  responsible party (PRP), and others concerned
with onsite investigations, site surveys and reconnaissance including some aspects of geological and
geophysical reconnaissance and logging that deal primarily with soils.  The guide is directed not only
to personnel who are experienced field investigators but also to those who may need to learn and
apply the basic principles of characterizing soils and their contaminants and the environment without
having had formal training. For that reason,  scientific terminology is defined in the text or in the
glossary.

The approach presented will be  unfamiliar to most investigators because it uses expert system-type
knowledge frames (sets of specific descriptive  information) to describe site and soil characteristics.
See the glossary for a description of an expert system, knowledge frame, knowledge-based system
tools, and inference engine.

Currently, the U.S. Environmental Protection  Agency (EPA) does not have a standard procedure,
guideline, or protocol for site description and soil characterization that addresses site and soil
contamination with metal or metalloid species.   In preparing this guide, new approaches within  the
expert system knowledge frame  context for description and classification have been developed that
emphasize questions and problems directed toward metal and metalloid contamination at hazardous
waste sites.  Various references  have been consulted to compile a comprehensive "knowledge  book."
Standard procedures for site and soil description and classification developed by the U.S. Department
of Agriculture Soil Conservation Service (SCS)  are used or have been modified to suit CERCLA-RCRA
field situations. SCS guidelines  have previously been modified for EPA projects, such as the
Direct/Delayed Response Project (DDRP) soil acid precipitation activities (Kern et al., 1988; USDA Soil
Conservation Service,  1979).

The guide is organized as follows. Section 2 outlines general considerations and processes for
collecting and using site and soils data. Sections 3 and 4  present detailed knowledge frames of the
site and soil conditions most likely to be encountered in the field.  A number of these conditions
pertain to both the natural and contaminated environments. A references cited list; an appendix listing
common sources of characterization data, soil  and hydrogeologic parameters for characterization of
contaminated soils; and an extensive glossary  complete the guide. The glossary includes definitions
of almost 900 technical and scientific terms used in the knowledge frames to define sites, soils, and
Guide to Site and Soil Description

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                                                                                 Introduction
contaminants within the CERCLA-RCRA framework for hazardous waste site investigations.  A soil
description form and methods are included.

Users of this guide should be aware that the knowledge frames presented in Sections 3 and 4 are
also the basis for the site and soil components for metals and metalloids of the Environmental
Sampling Expert System (ESES) under development by the EPA Environmental Monitoring Systems
Laboratory-Las Vegas (EMSL-LV) through EMSL-LV's prime contractor, Lockheed Engineering &
Sciences Company (LESC).  The format of the knowledge frames is designed primarily for use with
the ESES, but the frames should also provide a logical and consistent reference for those who intend
to use this knowledge book alone or in association with the Field Pocket Guide (Boulding, 1991).
Because users of this knowledge book are likely to be the eventual users of ESES, the knowledge-
frame format is maintained to enhance consistency among related documents.

The Environmental Sampling Expert System-Soil Metals (ESES-SM) incorporates both user factors and
site factors to determine the design of a sampling plan. Figure  1-1 depicts the interdependencies
among the several factors involved.  Analytes and characteristics of interest, intended use of the data,
and resources available are summarized in the statement of the DQOs, which in turn determine the
method requirements.  The source, type, and extent of contamination, as well as field conditions,
complement the input for preparation of a sampling plan.  Based on information about these aspects,
ESES-SM provides advice on a  number of categories that form part of the sampling plan. These
categories are: requirements for attainment of statistical confidence and representativeness (e.g.,
sample size, number, and location); QA/QC measures; sampling procedures, techniques, and
equipment; sample handling and shipping; documentary procedures; and safety measures.  Site and
medium (soil) characteristics provide data and information as needed in the ESES-SM
interdependency diagram.

ESES makes extensive use of hypertext techniques.  Familiarity with hypertext techniques is needed to
use the knowledge frames and information in a computer.  Hypertext is a method to present
information in a computer.  Each portion of text presented on the computer screen may  contain
highlighted terms which can be  selected for further explanation.  The explanation will appear in a
separate "window" on the screen and the user can return to the original text when finished with the
window.  Each explanation window may contain more hypertext terms, which can be selected at the
user's command, forming a chain of concepts.  This feature allows for various levels of on-screen
information according to the user's level of background in the subject matter. Novice users can make
extensive use of hypertext and find the system self-explanatory, while more experienced users will not
be forced to read familiar information. The use of hypertext gives ESES and  ESES-SM value as  a
training tool and also makes it appropriate for use by individuals with wide-ranging backgrounds and
levels of expertise.
Guide to Site and Soil Description              -|-2

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                                         SECTION 2.0

             COLLECTION AND USE OF SITE AND SOIL CHARACTERIZATION DATA
Site and soil characterization data, and knowledge and understanding of their variability are important
components in developing the sampling plan for a particular hazardous waste site. These data impact
many decision points in the integration of sampling plan elements (e.g., intended use of the data,
analytes of interest, sampling  and analytical methods, statistical design, remedial action).  For
hazardous waste sites, where a primary objective is to determine the nature and extent of
contamination, site and soil characterization may be strongly oriented toward health and safety
factors, not only for an initial entry team, but also for subsequent investigators. Data on
environmental, ecological, climatic, physical, chemical and biological, and other factors, however, must
be gathered not only to provide an overview of the site, but also to determine details as to its
complexity and extent, and to adequately  support decisions about data quality objectives  (DQOs).
Consequently, it is important to  consider and synthesize data from all available sources in developing
descriptions for a particular site and its soils. These sources include reference documents; site
background reviews; field reconnaissance; actual sampling activities; and information from
cooperating scientists in such fields  as soil science, geology, hydrogeology, chemistry, agriculture,
climatology and microclimatology, botany, zoology,  ecology, photointerpretation, geographic
information systems, statistics, quality assurance, and numerous engineering disciplines (e.g.,
agricultural, civil,  and mechanical).

Regardless of the sources or methods of data collection,  all elements of the site and soil
characterization process must be designed and executed in a  manner appropriate to the intended use
of the data.  Thus, both experienced and inexperienced field personnel should concentrate on
identifying and asking the questions that will provide qualitative and quantitative data appropriate to
solving the problems of interest at a particular hazardous waste site.  The remaining discussions in
this section are intended  to aid  in identifying the questions and issues of concern in performing the
site background review, in describing and characterizing the site and the soils present, and in
determining and supporting the intended use of the data.

2.1     SITE BACKGROUND REVIEW

Although direct, on-site observation  provides the most detailed information about site and soil
characteristics, basic data on  site features can  often be obtained from existing sources before field
work begins.  These data are  often essential in planning reliable field reconnaissance and sampling
efforts. The data may be general or specific, depending on the sources available for the particular
geographic location.

During the site background investigation, the scientist should ask, at a minimum, eight basic  questions
concerning site and soil characteristics:
Guide to Site and Soil Description               2-1

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                                                                     Collection and Use of Data
   -   What is the area of the site? Indicate the area of the site in hectares and describe the
      configuration (square meters, length and width).

   •   What is the depth to ground water? Indicate the depth to ground water from the ground
      surface, and, to the extent known, identify seasonal fluctuation and the depth and thickness of
      multiple aquifers.

   -   What is the level of ground-water use? Identify both potable and nonpotable ground water
      use(s) by aquifer, if appropriate, and the point(s) of extraction relative to the site.

   •   What is the potential or maximum rate of contamination?  Indicate the potential or maximum
      rate of various soil and ground water contaminations that impact the site. Include vertical flow
      rate through the unsaturated (vadose) zone to ground water, and any horizonal  flow rate in the
      aquifer.

   •   What soil "types" are present and what is their depth? Identify, to the extent known, the site's
      soil strata, its characteristics, and  its relative extent below ground surface.  Characterization of
      the soil medium should begin with data available through soil surveys made by the SCS and
      through contact with soil survey personnel, local soil scientists, engineering personnel, and
      county extension personnel. This early investigation will save time and resources and will
      minimize duplication  of effort in obtaining needed or desirable data on soil characteristics.

   •   What sensitive receptors are in proximity to the site?  Identify population and environmental
      concerns relative to the site that could be impacted by contaminant migration through various
      media via air, surface water and ground water.

   •   What and where are the locations of potential sources of site contamination? Identify  and
      locate potential sources of contamination that could impact the site  under investigation as well
      as potential sources  of contamination from the  site to the surrounding environment.

   •   What documentation is available? What resources can be accessed to obtain information
      about the site, its history, land use, land modifications, initiation and age  of contamination,
      etc.? Consult personnel, agencies and records.

Thoroughness in obtaining data on these topics will improve the efficiency and quality of subsequent
planning and field work.  Appendix A describes the components of a site/soils background  review in
more detail and lists major sources of data useful in the  systematic assessment of hazardous waste
sites.

2.2   SITE DESCRIPTION

After a designated site has been selected for investigation and the background review has been
conducted, the area (landscape) around the site should be examined for its identifying characteristics,
Guide to Site and Soil Description              2-2

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                                                                      Collection and Use of Data
and the resulting data and observations should be assessed in conjunction with the available
documentation, such as soil boring logs from any previous drilling activities.  These environmental
observations on the climate, soil, ecology, physical and chemical attributes of the site should be as
complete, objective, and clear as possible and should be recorded in a notebook or on a form
devised for this purpose. The use of a standard form will assist in subsequent data entry and
interpretation.  A sample form is provided in Appendix C. A sample form for soil profile and related
information also is provided in A Field Pocket Guide (Boulding, 1991).

The site reconnaissance is intended to confirm the results of the preliminary background review and to
identify site characteristics that may indicate contaminant sources and migration paths, affected
populations, and potential monitoring sites.  Thus, it is insufficient to collect data on only the soils
under consideration, information on site environment and its spatial and temporal variability are also
needed.  The investigator must also observe the  surficial geology, topography, slope, erosion patterns
(wind derived and water derived), streams and other water bodies, and surface microrelief.  Other
important observations include:

   •   Evidence of animals and kinds of animals (e.g., cattle, rodents, birds, wildlife) and their
      numbers and degree of activity.  Sufficient  time should be allowed  for actual  sightings, if
      needed.  In  addition to visual sighting of animals, evidences of habitation, tracks, paths of travel,
      feeding remains, fresh or old bones, fresh or decomposed dung, and  distribution and numbers
      of burrows should be recorded, particularly with reference to source and extent of
      contamination.  Consult the literature and area biologists regarding possible  endangered
      species which may affect the approach to cleanup.

   -  Plant species and distribution on- and off-site, particularly with reference to effects  of
      contamination on-site as determined by plant stressors.  Note especially the  types of vegetation,
      (e.g., trees,  shrubs, grasses and other flowering plants), and  note the lack of vegetation if little
      or none is present.  Determine which kinds of vegetation are the most abundant or typical, and
      note their distribution  (dense, scattered, irregular, or even) by species, and the amount of
      vegetative growth (prolific, moderate, or scant).  Depending on the time of year, the climate, and
      the local weather (especially in a favorable moisture-temperature regime), and reproductive
      features  (e.g., fruits and flowers) of plant species also may be noted.  If possible, estimate the
      age and  apparent health of the vegetation and plant stresses such as stunting, chlorosis,
      diseased tissues and organs and changes in kinds and distribution of vegetation.  These
      vegetation features are important to determining the age and "health"  of a disturbed site.
      Information  also should be obtained regarding possible endangered plant species.

   •  Meteorologic factors, climate and weather are important site characteristics and also have an
      important role in soil formation and the amelioration  and remediation of disturbed and
      contaminated soil sites.  Long-term climatic data may  be obtained from the U.S.  Department of
      Commerce; weather information may be obtained from a local weather station.  Meteorological
      and micrometeorological or microclimatic factors should be noted  or measured because they
       may affect sampling procedures and safety considerations; the quality of the collected sample,
 Guide to Site and Soil Description               2-3

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                                                                     Collection and Use of Data
      its handling, and subsequent storage and analysis; and instrumental measurements made on
      site.  For example, to avoid contamination, samples should be protected from the wind.
      Collected samples should not be exposed to the sun or to high or varying temperatures, such
      as from varying cloud cover, or from high relative humidity. Precautions also should be taken in
      collecting, handling and storage of wet samples to avoid condensation and adverse microbial
      effects, e.g., anaerobic conditions, promoted by closed containers.  External environmental
      factors, e.g., temperature, relative humidity, wind, solar radiation and evaporation, and
      barometric pressure, also may affect certain instrumental readings and analysis in the field.
      Field measurements needed to characterize the external site environment may include
      measurements for the nature and extent of cloud cover, relative humidity, barometric  pressure,
      evaporation rate, temperature, meteoric precipitation (recent or present at time of sampling), and
      microclimatic wind profile (from surface to approximately 1 m above the surface), including wind
      direction and velocity.  If instruments and time are available for these readings, it is advisable to
      take readings for extended periods (more than a few consecutive days), and for a given space
      (depth or profile) of the site environment selected for measurement and observation.

      If possible, measurements should be made before, during, and after collection of samples.
      Diurnal environmental measurements, such as for temperature and humidity, are preferable to
      those made at only one point in time.  If it is determined that other environmental factors could
      affect sampling,  e.g., wind, then other microclimatic measurements may be made, especially if
      site disturbance varies from the undisturbed area.  Additional measurements may include onset,
      amount, and duration of dew; net or total exchange of thermal radiation; occurrence,  duration,
      and intensity of sunlight; and site elevation. Solar radiation data can usually be directly related
      to atmospheric stability; models to compute rates of chemical vaporization may use solar data
      quantitatively.

   -   Anthropomorphic features such as buildings, embankments, excavations, bridges, roads,
      impoundments, berms, dumps, landfills and debris, and any other artifacts or evidence of
      human activity, both past and present (e.g., visible household/industrial refuse and scrap;
      vehicle paths, tracks, and miscellaneous parts and fluids)  should be noted.

It is better to make all additional observations or measurements of potential interest and to  make too
many notes, rather than too few.  Record special or unusual features in the site environment that may
influence the disturbed soil and the collection of samples (e.g., presence of hazardous materials or
objects containing flammables, poisons, combustibles and radioactivity). It is also extremely important
to record all observations while at the sampling site.  Subsequent recall of pertinent information about
the area, site, and in situ features of the soil is not reliable, and  it may not be possible to repeat the
observations due to constraints of time, circumstance, or logistics. Properly identified photographs
and maps of area, site, soil, and other features, including sampling procedures, are important records
for site characterization and for subsequent risk assessment, remedial actions, and possible testimony
and litigation.
Guide to Site and Soil Description        .      2-4

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                                                                       Collection and Use of Data
2.3   SOIL DESCRIPTION

Soil description for hazardous waste site investigation incorporates features of standard soil
description and specialized data unique to the evaluation of metals contamination. Basic descriptive
elements are discussed in Section 2.3.1. Application of these elements to different hazardous waste
sites for investigative purposes is described in Section 2.3.2.

2.3.1  Basic Soil Description Components

A basic soil description considers the soil's physical location  (i.e., as a naturally occurring, three-
dimensional piece of landscape), its derivation (parent materials) and deveiopment (soil forming
factors), and its composition (i.e., minerals, organic matter [living and dead], water, and air).

Soils vary in their physical, mineralogical, chemical, and biotic properties, all of which, in consideration
of their derivation and stage of development, constitute a descriptive kind of soil or soil "type" (map
unit).  Categorical or taxonomic units are used to classify soils.  There are six major soil diagnostic
features (epipedons) and fifteen horizon (diagnostic layer) descriptors,  plus additional descriptors,
such as for pans (hard layers). Disturbed or contaminated soils may not fit into the standard
classification that soil scientists use. These soils, however, can still be characterized according to
basic soil properties, in accordance with project DQOs. The  knowledge frame on soil horizons
provides information describing typical master horizons and layers, transitional soils and also
disturbed, and buried soils which may be encountered at hazardous waste sites.

A "standard" soil description draws on many site, soil, and procedural characteristics (USDA Soil
Conservation Service, 1987;  also see A Field Pocket Guide, Boulding 1991).  These characteristics
include a taxonomic classification as to soil  series; date of collection; site location (latitude, longitude,
and elevation); slope; microrelief; geomorphic position; physiography; local landform and land use;
depth to water table; flooding characteristics; pedon (soil body) classification;  parent material; climatic
and weather information, including weather  station identification; vegetation cover and species; soil
depth; diagnostic features; and collector's name and affiliation.

Specific soil information includes a classification of soils, horizon (strata) designations, thickness and
depth; dry and moist color (Munsell notations); texture; structure; consistency  (dry and moist);
evidence and description of mottles (discolorations); surface features; evidence of roots; macro and
mesobiota; pores; rock fragments; various kinds and shapes of concretions; and a description of
organic matter.  Field measurements may be determined for such characteristics as effervescence
(carbonate),  moisture content, hydraulic conductivity,  infiltration and  percolation rate, surface and
subsurface temperature, pH, and Eh.  Other samples should be collected which can be measured
either in the field or solely by  means of laboratory instruments, e.g.,  pH and Eh, specific ions, cation
and anion exchange capacity, microbiota, electrical conductivity, water potentials, organic matter and
its components.
 Guide to Site and Soil Description               2-5

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                                                                     Collection and Use of Data
Texture, structure and porosity are among the most important physical soil properties where solute
transport is concerned and chemical migration is affected by mineralogy, especially clay minerals, Ph,
Eh, and organic matter, although most metal species may be relatively immobile.  Although soil texture
can be roughly estimated in the field by "feel," mechanical analysis can be used to determine more
than 40 textural classes; and 20 textural modifiers can be used to describe soils.  Use of a soil texture
triangle (Figure 2-1) provides a simple method of measurement for this parameter. A mechanical
analysis can be performed to show that a soil that is 30 percent silt and 70 percent clay by texture, for
example, is classified as "clay," whereas, a soil that is 60 percent sand and 30 percent clay is
classified as a "sandy  clay loam." Estimations of soil texture may require some experience. A
laboratory analysis should be performed to determine the percentages of soil separates, sand, silt and
clay, and resultant textural class.
                                        peront sond
Figure 2-1. Soil Texture Triangle.  Example: A soil with 20% clay, 40% silt, and 40% sand is a loam.
Guide to Site and Soil Description
2-6

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                                                                          Collection and Use of Data
    Various texture classes differing from those used in soil science in the United States are used in
    engineering operations and in other countries.  The ASTM system and Unified Soil Classification
    System (USCS), for example, applied to design and construction of roads, airfields, dams, etc., group
    soils partly on the basis of particle-size distribution and partly on the basis of Atterberg plastic and
    liquid limits. For the USCS, four soil fractions are recognized: cobbles, gravel, sand and fines. Three
    major divisions are recognized with 15 soil groups. The major divisions are coarse-grained, fine-
    grained, and highly organic soils. The USCS  can provide a rather good characterization of the particle-
    size distribution and physical behavior of soil materials, but due to its overall simplicity, it is suited
    primarily for an evaluation of fill materials and cannot be used to predict soil behavior  in terms of
    chemical reactions (Dragun, 1988).  Although the USDA system is directed toward identification of
    soils for agricultural and land use, it is sufficiently uniform for general prediction of chemical migration
    in soil and therefore also is of value for similar purposes in predicting migration of chemicals in
    contaminated soil.  For site remediation and construction purposes, the ASTM or USCS may be
    preferred over that of USDA. A  comparison is given below of the ASTM, USCS and USDA systems for
    classification of soil texture (Table 2-1).

                                              TABLE 2-1.
                Comparison of ASTM,  USCS and USDA Soil Textural Classification Systems
ASTM
USCS
USDA

colloids
Clay
silt
Fines (silt or clay)
Clay
I I I II III
silt
I I I I I III
Fine
sand
Fine
sand
Very
fine
sand
I I I I Ml
Fine Medi
sand sat
I I I
Coarse
sand
Medium
sand
.urn Course
id sand
I I I III
Very
coarse
sand

0.0001
                       0.001
                                               0.01
                                                                        0.1
                                                                                               1.0
                                                                                                      2.0
                                       Particles size in millimeters

    Many descriptors can be used for grade, shape, and size of soil structure.  Depending upon the time,
    degree, and extent of possible manipulation at a given site, naturally occurring soil structure may be
    severely altered or destroyed. Soil structure descriptions should not be divorced from considerations
    of other soil properties, especially texture, horizon descriptions, porosity, and permeability.
    Guide to Site and Soil Description
2-7

-------
                                                                      Collection and Use of Data
Consistency is an indication of the degree of cohesion or adhesion of the soil mass, and can be
determined as gradients of dry to moist, or as brittle, cemented, or fluid. A strongly cemented, or a
sticky, plastic soil is not conducive to "standard" methods of soil sampling.

The content, activity (potential), movement and rate of flow of water is very important in the soil, not
only for the growth of plants and microorganisms, but also in  regard to migration, movement, and rate
of movement of solutes, nutrients and contaminants. Measurements for water content, infiltration and
penetration rate, various water potentials,  and hydraulic conductivity,  both saturated and unsaturated,
are important in this regard. Water measurements,  especially those for hydraulic conductivity, can be
complex.  A detailed knowledge frame is provided for hydraulic conductivity that includes some theory
as well as practical understanding, usage and interpretation.

Soil inclusions can have an effect in determining the rate of water movement and solutes in the soil
profile. There is less potential for water (and ions) to migrate  through soil mottles of medium to
coarse size (between 5 and 15 mm diameter).  A change in the soil moisture regime may be indicated
by the proportion of colored mottles.  Light grey mottles may indicate a reducing soil environment,
and a greater tendency for water activity than an oxidized environment of yellow-brown, brown, and
red mottles. Naturally occurring mottles versus mottles formed from soil contamination should be
noted, along with distinguishing surface features such as coats, stains,  and films; their quantity; and
their continuity. Soil color, minerals, aeration, and Ph-Eh are related features.

Boundaries of changes in the soil, such as in horizons, should be noted in terms of distinctness (e.g.,
abrupt, gradual, clear, or diffuse) and topography (e.g., smooth, wavy, irregular, or  broken), especially
in regard to the contamination source and its migration.

Soil microbiota (e.g., bacteria), along with mesobiota (e.g., earthworms), may not be determined for
contamination sites, but they may provide, by their abundances, kinds and distribution, information
about site contamination.  They, along with the macrobiota, for example, rodents (macrofauna)  or
small and large animals (megafauna), may serve as "indicators" of contamination. Special care should
be taken in the sampling and handling of soil for micro- and mesobiota to avoid sample bias, for
example, microbial contamination, or alteration of populations in closed containers exposed to altering
temperatures.

Soil organic matter is another important soil constituent and may be visibly apparent. It is usually
reported in analyses performed by the SCS,  along with soil Ph, effervescence, color, odor,  and
chemical constituents, both macronutrients,  such as phosphorus,  and micronutrients, such as iron.
Organic litter also may occur on the surface of the soil in various stages of deposition and
decomposition, and roots may be present in the surface or subsurface soils.

Changes in color, odor, and corrosivity may be important considerations in contaminated soils
compared to uncontaminated soils, and may provide clues about the nature and extent of
contamination.  Most soil properties do not interfere with standard procedures in soil sampling  (e.g.,
removal of surface litter prior to sampling  or breaking up of compaction or crusts).  In soils that
Guide to Site and Soil Description               2-8

-------
                                                                      Collection and Use of Data
contain significant amounts of organic matter, however, metal-complexes (ligands) formed with organic
matter are an important factor in sorption, fixation, and both the mobility and immobility of cations and
anions, including metal species.

Other soil factors, such as kinds, numbers, sizes, and distributions of various concentrations (e.g.,
crystals, modules, nodes, masses,  and concretions) should be noted in contaminated soils, especially
if formed by processes subsequent to contamination.  Kinds, shapes, number, and distribution of
macropores (e.g., tubes, vesicles, or fragments) are relevant to infiltration, permeability and
percolation; soil  crusts, rock fragments, and stony or desert pavement  likewise will affect these soil
properties.

2.3.2  Description for Hazardous Waste Projects

A project description includes all response activity plans (US EPA, 1987).  It is required in the quality
assurance (QA)  and sampling plans for remedial investigations and in the work plans for the Field
Investigation Team (FIT) operations. The Site Manager (SM) is responsible for the successful
completion of the work assignment, within budget and schedule. Pertinent information used to develop
the project  description is the responsibility of the SM.  Information for the project description would
include results of previous site investigations;  any environmental permits associated with the site; tax
records; results of inspections by other state,  local, or federal agencies; newspaper accounts; records
from community relations interviews; aerial photographs (such as those typically available from the
Environmental Photographic Interpretation Center); and any other data that will assist the SM in
developing the project description and statement of objectives. It is important, particularly on projects
involving enforcement activities, that adequate records be kept to document the process by which
project objectives were derived.

The project description should be site-specific and include at least the  following items:

• Site description and history
• Schedule of activities
« Intended data usage
» Identification of samples matrices and parameters
• Sample design description and rationale

For the site description, all pertinent physical and land use information should be  obtained.  Maps,
drawings, and photographs should be included, if available.  These include the following:

  •   Size,  including area within facility boundaries and the extent of contamination  above defined
      thresholds (threshold limit value), if known.
  •   Specific location description, including directions and distances from nearby towns.
  •   Surrounding geography (e.g., town, city, county, or state boundaries and jurisdictions; power
      lines; railroads; roads; and topography)
  •   Physical and environmental description  including the following:
Guide to Site and Soil Description               2-9

-------
                                                                      Collection and Use of Data
               Geologic conditions
               Soil "types" and depths
               Surface water hydrology
               Ground water hydrology
               Flora
               Fauna
               Terrain
• Onsite conditions (e.g., the presence of pits, ponds, tanks, drums, standing water, buildings, and
  wells)
• Climatological description for the region and for site-specific parameters, such as wind speed and
  direction, precipitation patterns, and freezing conditions
• Demographics and surrounding land use (e.g., agricultural, industrial, or residential; populace at
  risk; and transportation patterns)

A review of EPA documents shows that the emphasis on soil characterization and the particular
parameter to be determined vary considerably, depending on the DQOs for the particular hazardous
waste project.  For site characterization, attention usually focuses on the soil properties that are most
useful in characterizing the soil-contamination system.  For example, in site characterization, leaching
potential and attenuation of contaminants are the major concerns; therefore, soil slope, surface
drainage, the extent of highly contaminated soils, and the practicality of using particular field
contaminant instrumentation may be the most important considerations in the soil description process
(US EPA, 1986a). Additional major concerns could include the depth (thickness), texture, structure,
porosity, roots,  and nature of underlying geologic materials. As an adjunct to ground-water
monitoring, on the other hand, the emphasis may be on soil properties that help establish the amount
of contamination sorbed on aquifer solids that may contribute to ground-water contamination (US
EPA, 1983). For this purpose, it is indicated that it is important to collect detailed information such as
soil grain size (texture), cohesiveness, moisture content, color, and odor and to make numerous
readings with field monitoring equipment for the designated soil parameters.  In addition, it is indicated
that physical factors such as temperature, oxygen, and light penetration should be measured to
provide an interpretive basis for conditions that may radically alter the rate of chemical reaction and of
associated microbial activity.

In contrast to the requirements for site characterization, the DQOs for remedial response activities may
emphasize the collection of data for a different set of soil parameters. These data would include soil
"type," Ph, cation exchange capacity,  and physical measurements for hydraulic conductivity, hydraulic
head, penetration rates,  permeability, porosity,  grain size, and bulk density. Additional observations
might include a description of soil depth,  hardness, stratification, discoloration, and surface
depressions (US EPA, 1987a). These soil properties may be determined regardless of the nature  of
the contaminant.  For metals, the vertical contaminant distribution is expected to be limited if the
contamination occurred  at the soil surface.  Metals are relatively immobile and their downward
migration is usually limited, dependent upon various soil properties, e.g.,  clay mineralogy, cation and
ion exchange, organic matter content and distribution, moisture content and potential, infiltration and
penetration, hydraulic conductivity and gradient.
Guide to Site and Soil Description              2-10

-------
                                                                      Collection and Use of Data
When the project constitutes an emergency response, basic data are needed not only regarding the
soil per se, but also erosion, type of surface runoff, and slope characteristics. Of particular importance
are soil texture, structure, consistency, infiltration and permeability, cations and anions,  and exchange
capacity for clay minerals and organic matter.  Mason (1983) provides useful guidance  in these areas.

2.4   INTENDED USE OF DATA

Intended use of the data may focus on site characterization, health and safety, risk assessment,
evaluation of alternatives, engineering design of alternatives, monitoring during remedial action,
identification of potentially responsible parties (PRP), or possible use in litigation.  Each type of use
may necessitate sampling of soil for the required remedial investigation and  remedial response
activities.

The quality, quantity, and level of detail for collected data and information will vary and  are largely
based on their intended use. Each site has a unique history, and the amount and quality of data
available will vary. These factors must be considered in establishing and working toward the DQOs
for the project. Data quality, quantity, and intended use will impact site-specific decisions, the needs
of data users,  and the requirements for further sampling and analysis.

DQOs should  be  based on  data-use categories.  Specific site investigations may require data for one
or more purposes, but as a rule methods for collecting and analyzing data should be designed to
satisfy project  DQOs at a level appropriate for remedial response activities.

Data use categories for remedial  activities are discussed in US EPA 1987b and are summarized as
follows:

   •   Site Characterization - Data generated through the sampling and analysis of waste sources
      and environmental media are used to determine the nature and extent of contamination at a
      site.

   •  Health and Safety - Data are used to establish the level of protection needed for  site
      investigators or workers and to establish precautions needed to protect populations in the
     vicinity of the site.

   •  Risk Assessment  - Data are used to evaluate the threat posed by a site to public health and the
      environment.  Risk assessment data are generated through the sampling and analysis of
     environmental and biological media,  particularly where the potential for human exposure is high.

   •  Evaluation of Alternatives - Data are used to evaluate available remedial technologies and to
     develop  cost estimates. Evaluations may involve performing bench-scale or pilot  scale studies
     to determine the effectiveness of a particular process or material.
Guide to Site and Soil Description              2-11

-------
                                                                     Collection and Use of Data
  -  Engineering Design of Alternatives - Data collected during the remedial investigation/feasibility
     study (RI/FS) can be used to develop a preliminary engineering design data base on the
     performance of remedial technologies. Data applicable to the remedial design (RD) process
     include waste characterization and preliminary volume estimates. These estimates usually need
     to be refined during the Remedial Design/Remedial Action (RD/RA).

  •  Monitoring During Remedial Action - During the remedial action, samples can be taken to
     assess the effectiveness of the action.  Based on the analysis of these samples, corrective
     measures may be taken.

  •  PRP Determination - Data may be used to help establish liability at  multiple-party sites.  For
     known PRPs, data are used to link their wastes to those found on the site and to pollutants
     released to the environment. For unknown PRPs, data are used in comparing the site wastes to
     pollutant profiles of known waste streams.  Data are also used for injunctive actions and cost
     recovery.

  •  Litigation - For this purpose, policies, procedures, and documentation should meet EPA
     National  Enforcement Investigations Center (NEIC) requirements (US EPA, 1978). Activities and
     procedures of interest include project review, background review, project plans, project
     activities, and report and follow-up on pollution problems related to all media.  The US EPA
     recommends Contractor Laboratory Program (CLP) procedures for litigation purposes.

After the data-use categories pertinent to a project have been determined, their order of priority
should be established according to the most stringent demand for use of the data. Thus, the highest
priority is the data use that requires the highest level  of confidence and the lowest level of data
uncertainty.  The limits of uncertainty will drive  the selection of project analytical and sampling
approaches, including those for soils.

Soil measurements needed to support CERCLA decision-making processes have been outlined by
Breckenridge et al. (1991). In addition to those included in the knowledge  frames of this guide, these
are depth to ground water, liner soil/water partition coefficient, the organic carbon partition coefficient,
and water erosion Universal Soil Loss Equation. Boulding (1991), in A Field Pocket Guide provides
additional tests and methods, including engineering properties and parameters: Atterberg limits
(consistency),  shear strength, shrink-swell, and corrosivity. Corrosivity (corrosion potential) and
consistency are included as knowledge frames in this guide.  Atterberg limits are included in the
"consistency" knowledge frames.

Once priorities for intended data use have been established,  the data types that need to be
developed are identified.  Subsequently, data quality  needs are defined, and  soil sampling and
analysis options  are evaluated.  Data types can then  be categorized to form a decision matrix to meet
the specifications of the data type needed for each intended  data use.
Guide to Site and Soil Description              2-12

-------
                                                                     Collection and Use of Data
The integration of site and soils data collection methods, DQO selection, and data uses involves many
complex decisions.  Mason (1983) provides useful flow charts and decision trees for site and soil
characterization.  US EPA (1987a and 1987b) offers guidance on the development and application of
DQOs.  Sections 3 and 4 of this guide are intended to aid the decision process by providing a uniform
basis for identifying site and soil characteristics in the field, whether measured in the field or when a
soil sample is subsequently taken to the laboratory for subsequent analysis.

This knowledge book may be used in conjunction with the Field Pocket Guide for measurements and
tests to be performed in field or on  samples returned to the laboratory for analysis. Figure 2-2
illustrates the relationship of various aspects of ESES, the knowledge book and Field Pocket Guide
and the appropriate,  sequential use of the two guides.  It should, however,  be considered that the
knowledge book also is available in the  computer.

Site and soil characteristics and parameters are included in both the knowledge book and Field
Pocket Guide. Correlation of these parameters is given in Table 2-2. The list of parameters is followed
by the method of determination in the field and/or laboratory, and/or a "Lookup" in relevant references.
A discussion of the specific parameter also is indicated for the knowledge book in the Field Pocket
Guide.

The scope of the Field Pocket Guide is much broader than that of the knowledge book and therefore
includes additional or supplementary tests which may be performed, e.g., soil engineering tests and
those related to organic contaminants and wastes.  In Appendix D of this document, principal site
characteristics and soil  parameters  are included along with a brief, specific  mention of field and/or
laboratory methods, calculations or data/information to be looked up and appropriate references.

The US EPA SW 846 manual (US EPA, 1986b) should be used whenever possible for test procedures
to evaluate those properties of a solid waste which determine whether or not the waste is defined as a
hazardous waste according to Section 3002 of RCRA (PL 94-580). The methods delineated in this
manual are approved for obtaining data to satisfy the requirement of 40 CFR Part 261, "Identification
and Listing of Hazardous Waste." This manual encompasses methods for collecting representative
samples of solid  wastes, and for determining the reactivity, corrosivity, ignitability, and  composition of
the waste  and the mobility of toxic species present in the waste. Several methods for soil tests are
included, i.e., cation exchange capacity, pH, and hydraulic conductivity (saturated), and are
referenced in Appendix D.
Guide to Site and Soil Description              2-13

-------
                                                                      Collection and Use of Data
                           IDENTIFICATION OF
                             SOURCES  FOR
                            EXISTING  DATA
                            HISTORICAL  DATA
                              EVALUATION
                              PRELIMINARY
                            SITE  INSPECTION
                                                   WHAT
                                                   IS
                                                   KNOWN
	I	
I    DEFINITION OF
jPROJECT GOALS AND
      OBJECTIVES
                                                                             WHAT
                                                                             NEEDS TO
                                                                             BE KNOWN
                              SELECTION  OF
                              PARAMETERS TO
                                MEASURE

                            	I	
                            DEVELOPMENT  OF
                             QUANTITATIVE
                             DATA QUALITY
                              OBJECTIVES
                     I
              SAMPLING AND
              ANALYSIS PLAN
               PREPARATION
       SAMPLE
     COLLECTION
      FIELD
  DETERMINATIONS
RECORD DATA
  LOOKUP
                                                   HOW TO
                                                   DETERMINE
                                                   WHAT NEEDS
                                                   TO BE
                                                   KNOWN
!
1
1 1
| LABORATORY |
j ANALYSIS |
I i
I

i
i
1
1
1
i

                          ||  DATA ANALYSIS
                          AND INTERPRETATION
                               DECISION
                              AND ACTION
        Guide to site and soil Description use
        Field Pocket Guide use
  Figure 2.2. Applicability of Guide to Site and soil Description  and  Field Pocket Guide to
              Site  characterization Phases.
Guide to Site and Soil Description
                    2-14

-------
                                                                     Collection and Use of Data
                                          TABLE 2-2.
                Site and Soil Characterization Parameters and Their Determination.
                     Adapted from Russell Boulding (Eastern Research Group)

Parameter
1 . Water Budget Parameters
a. Precipitation
b. Infiltration
c. Evaporation
d. Evapo-transpiration
e. Surface Runoff
2. Other Climate Parameters
a. Air temperature
b. Wind speed/direction
c. Humidity
d. Insolation
3. Geomorphology
a. Slope gradient/length
b. Slope form/landscape position
4. Erodibility
a. Water Erosion
b. Wind Erosion
5. Surface Hydrology
a. Surface streams
b. Flood frequency/duration
c. Water Bodies
6. Site Biota
a. Vegetation
Site and Soil
Guide
o
o
o
o
o
o
0

o
Determination Method
Field

•
•
•
•
•
•
•
•
•
•
•
•
Lab
•





Lookup
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
              • - Can be determined where indicated
              o - Discussed in "Guide to Site and Soil Description ..."
              s - Take sample in field for laboratory analysis
Guide to Site and Soil Description
2-15

-------
                                                                     Collection and Use of Data


Parameter
7. Horizons
8. Texture
9. Color
1 0. Porosity
1 1 . Zones of Increased
Porosity /Permeability
a. Soil Structure
b. Roots
c. Lateral features
d. Sedimentary features
12. Zones of Reduced
Porosity/Permeability
a. Genetic horizons
b. Consistency
c. Bulk density
d. Root Restricting layers
13. Soil Engineering
a. ASTM (Unified) texture
b. Atterberg limits
c. Shear strength
d. Compressibility
e. Bearing capacity
f. Compaction
g. Erosion resistance
h. Shrink-well
i. Clay dispersivity
j. Frost heave
k. Corrosivity
Site and Soil
Guide
o
o
o
0


o
o
o




o
o







o




o
Determination Method

Field
•
•
•
•


•
•
•
•


•
•
•
•

•
•
•


•
•

•

•

Lab

•

•









•



•
•
•

•
•

•
•

•

Lookup
•
•
•
•


•

•








•


•
•
•
•
•

•
•
Guide to Site and Soil Description
2-16

-------
                                                                      Collection and Use of Data

Parameter
14. Soil Water State
a. Moisture content
b. Water potential
c. Water retention
d. Available water capacity
e. Moisture regime
1 5. Internal Free Water
(Saturated Zone)
a. Depth
b. Thickness
c. Duration
1 6. Permeability/Hydraulic
Conductivity
a. Saturated
b. Unsaturated
1 7. Contaminant Transport in Soil Water
a. Velocity
b. Water/solute flux
c. Dispersivity
18. Volatilization (see, also 20a to 20e)
a. Air permeability
b. Gas diffusivity
c. Gas flux
d. Air temperature (see 2.a)
e. Wind speed (see 2.b)
19. Ground Temperature
a. Soil temperature
b. Soil temperature regime
Site and Soil
Guide
o
o

o
0
o

0
o
o
0
Determination Method
Field
•
•
•
•
•
•
•
•
•
•
•
•
•

•
•
Lab
•
•
•
•

•
•
•
•
•
•

Lookup
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Guide to Site and Soil Description
2-17

-------
                                                                     Collection and Use of Data


Parameter
20. Soil Chemistry
a. Organic carbon/matter
b. Odor
c. Cation exchange capacity
d. Soil Ph
e. Soil oxygen
f. Redox potential (Eh)
g. Redox couple ratios
(waste/soil systems)
h. Clay Mineralogy
i. Other Mineralogy
j. Salinity (EC)
k. Sodicity (SAR)
1. Major cations
m. Major anions
n. Fertility potential
21. Soil Biota
a. Enumeration
b. Metabolism
c. Nutrients
C:N:P ratio
other nutrients
d. Activity/kinetics
e. Macrofauna and Mesofauna
f. Microbiota
22. Soil Pollution Situation
a. Type
b. Concentration
c. Odor
d. Depth
e. Volume
f. Date(s) of contamination
Site and Soil
Guide

o
o
0
o

o


o

o



0

o





o
0
o
o
o
0
o


Determination Method

Field

•
•
s
•
•
•

s
•
•
•
•
s
s
s

s
s
s


s
•
s

s
s
•
•
•


Lab

•

•
•
•
•

•
•
•
•
•
•
•
•

•
•
•


•
•
•

•
•





Lookup



•
•
•
•


•
•
•
•
•

•







•
•

•


•
•
•
Guide to Site and Soil Description
2-18

-------
                                                                     Collection and Use of Data

Parameter
23. Contaminant Hazardous Properties
a. Toxicity
b. Reactivity
c. Corrosivity
d. Ignitibility
24. Contaminant General
Chemical Properties
a. Chemical class
b. Molecular weight/structure
c. Melting point/boiling point
d. Specific gravity/density
e. Water solubility/miscibility
f. Speciation
g. Dielectric constant
25. Contaminant Chemical Reactivity
a. Acid/base
b. Oxidation/reduction
c. Complexation
d. Hydrolysis
e. Catalysis
f. Precipitation/dissolution
g. Polymerization
26. Contaminant Volatilization Parameters
a. Henry's Constant (Kh)
b. Vapor pressure
c. Vaporization temperature/
solubility (see 24. c and e)
d. Koc sorption (gaseous phase)
27. Soil Contaminant Sorption/Retention
a. Koc
b. Linear Kd
c. Nonlinear sorption constants
d. Octanol-water (Kow)
e. Residual saturation (Ko)
28. Soil Contaminant Degradation
a. Half-life/rate constant
b. Biodegradability
c. Degradation daughter products
Site and Soil
Guide
o





Determination Method
Field
•
•
•
•


s
s
•
s
s
s
s
Lab
•
•
•
•
•
•

•

•
•
•
Lookup
•
•
•
•


•
•
•
•
•
•
•
•
•
•
Guide to Site and Soil Description
2-19

-------

-------
                                        SECTION 3.0

                                 SITE KNOWLEDGE FRAMES
Sections 3 and 4 present site and soil knowledge frames that can be used in the field to identify and
describe soils. The knowledge frames are presented in ESES format in order to maintain continuity
between ESES documentation and derivatives such as this guide.

Each frame consists of the following information.

  •  An OBJECT/ATTRIBUTE line that indicates the particular characteristic to be identified or
    described (e.g., clay minerals, slope, Ph).

  •  A DEFINITION of the overall characteristic.

  •  A list of VALUES for the characteristic, that is, the conditions that may be assigned (e.g., high,
    moderate, low; prominent, distinct, faint).

  •  CATEGORY and PROPERTIES assignments (necessary to the operation of ESES but not of
    concern in the field).

  •  REFERENCES, keyed to a references cited section at the end of the document.

The following site knowledge frames are presented in Section 3:

       Nature of Heavy Metal Soil Pollutants
       Climate and Weather
       Slope
       Surface Erosion and Erodibility
       Surface Pollution Situations
       Surface Runoff
       Vegetation
       Wind Speed and Direction

Soil knowledge frames are  presented in  Section 4. The frames on the nature of heavy metal soil
pollutants and on meso-  and macrofauna can be considered either site or soil characterization.
Metals are included with site characterization because they are generally a surface pollutant. Meso-
and macrofauna are included with the soil knowledge frames although they are both on the surface
and subsurface and have interaction with the pedon. The extensive site knowledge frame for the
nature of heavy metal soil pollutants is the first knowledge frame to follow.
Guide to Site and Soil Description               3.-)

-------
                                                                    Site/Nature of Pollutants
OBJECT/ATTRIBUTE:  SITE/NATURE OF HEAVY METAL SOIL POLLUTANTS

DEFINITION:   Contamination of the soil with metals that have densities > 5 g/cc and
              that do not decompose, but tend to remain in the soil indefinitely.

VALUES:       RELATIVELY MOBILE AND TOXIC
              RELATIVELY NONMOBILE AND NONTOXIC
CATEGORY:   SITE BACKGROUND

PROPERTIES:  INPUT FACT

REFERENCES: Bear, 1957
              Bergkvist, 1987
              Bonnyai, et al., 1988
              Breton, et al, 1986
              Camerlynck and Likens, 1982
              Colwell, etal., 1987
              Corbitt, 1989
              Corbitt, etal, 1989
              Czupyrna, et al., 1989
              DeHaan and Bolt, 1979
              Franson, 1985
              Glysson, et al., 1989
              Godbold and Huetterman, 1987
              Greszta, 1988
              Jacobs Engineering Group, Inc.,  1989
      Kabata-Pendias, 1987
      Kabata-Pendias and Pendias, 1984
      Kabata-Pendias and Piotrowska, 1983
      Kobus and Kabata-Pendias, 1977
      Lodenius, 1987
      Mason, 1983b, pp. A1 -10
      Mattigold, Sposito, and Page, 1981
      Mayer and Schultz, 1987
      McColl and Pohlman, 1987
      Palmer, et al., 1988
      Shaw, 1989
      Sims, et al. 1986
      Stupar et al.  1991
      US EPA, 1986b
      Vinogradov, 1959
VALUE:        Relatively mobile and toxic

DEFINITION:   Residence time of the toxic heavy metals (density > 5 g/cc) in either the solid or liquid
              phase is relatively short, thereby enhancing active toxicity.

CONDITIONS:  The behavior and fate of metals added to soils are governed by the complex and
              dynamic soil system involving physical (and mineralogical), physical-chemical,
              chemical and biological reactions. Unlike many hazardous organic constituents,
              metals in the soil system cannot be readily degraded or detoxified.  They tend to
              represent a long-term threat in the soil system unless they can be permanently
              immobilized or removed.
Guide to Site and Soil Description
3-2

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                                                                        Site/Nature of Pollutants
               Concentration in the soil solution, rather than total quantity in the soil, is the primary
               concern.  Soil factors favorable to easy removal from soil particles and leaching
               promote accumulation in the soil solution and subsequent accumulations in plants
               and natural waters where they may be harmful.

               Soils can accumulate specific metal ions from solubilized wastes or waste solution as
               well as release them if subsequent additions of wastes alter soil factors, e.g., acid pH
               and solubilization of organic matter.  Reduced forms, even though present in low
               concentrations, are more likely toxic,  e.g., copper as cuprous rather than cupric.

               Heavy metals are, by definition, those elements  having a density > 5 g/cc in their
               elemental form.  They comprise 38 elements, but in usual terminology, they refer to
               twelve metals most commonly used and discharged as wastes by industry: cadmium,
               chromium, cobalt, copper, iron, mercury, manganese, molybdenum, nickel,  lead, tin,
               and zinc. The metalloids, boron and selenium are often included.  EPA's list of
               inorganic priority pollutants includes antimony, arsenic, beryllium, cadmium,
               chromium, copper, lead, mercury, nickel, selenium, silver, thallium, zinc and cyanide.
               Those that may present the greatest  potential hazards to animals, humans, or plants
               are considered to be cadmium, copper,  lead, mercury, nickel,  and zinc. A knowledge
               of metal/metalloid and cyanide sources is very useful in identifying and determining
               possible hazardous site and soil (and also subsurface and groundwater)
               contaminants, their behavior and migration.

               The main sources of heavy metal contaminants  are (1) industrial and urban aerosols,
               such as those created by fuel combustion, metal ore refining, and other industrial
               processes; (2) liquid and solid wastes from animals and humans; (3) mining wastes;
               and (4) industrial and agricultural chemicals.  Industrial solid wastes also should be
               included. In industries that use metals or are involved  in processes that use metals,
               metalloids or cyanides, sources of wastes result from off-specification  products, spills,
               processing wastes, and hazardous by-products.  There are more than 125,000
               generators of metal/cyanide RCRA wastes. They are generated largely by metal
               fabrication facilities, which perform  forming, plating and coating operations.  These
               same facilities also tend to generate concentrated solutions, such as spent baths,
               which can be affected by the land disposal ban.  Vehicle maintenance facilities also
               generate metal wastes, e.g., lead batteries in large numbers and volumes. Other
               large generators of waste include the printing and photographic industry (which
               primarily generate silver wastes), and metal manufacturing facilities, which generate
               metal plating and cyanide streams.

               Regulatory Impact Analysis (RIA) data show that in decreasing volume of combined
               waste, the following can be shown: chromium, cyanide, lead, cadmium and nickel,
               with lesser amounts of mercury and arsenic, followed by smaller quantities of selenium
               and thallium. This ranking appears to be in general agreement with industrial use
Guide to Site and Soil Description              3.3

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                                                                        Site/Nature of Pollutants
              patterns, publicly owned treatment works discharge, and other hazardous materials
              surveys.

              Waste sources of metals, metalloids and cyanides result primarily from processes
              involving metal surface treatment (electroplating, immersion plating, chemical etching,
              chemical milling and bright dip); printed circuit board manufacture; petroleum refining
              (including waste water treatment sludges); inorganic pigment manufacture; wood
              preservation (one of the largest sources of arsenic containing wastes); and
              miscellaneous industries such as photography, printing, rubber and chemical
              manufacturing, pigment production, steam-electric industry, production of explosives,
              catalyst bases, metal forming and production industries,  and nonferrous metals
              industries.  In addition to metal wastes, associated wastes, frequently discharged into
              streams and in soils or in containers, can contain acids such as hydrochloric, sulfuric,
              hydrofluoric, and boric acid.  Primary alkalies can include sodium hydroxide and
              sodium carbonate.  Metals can also be frequently discharged into streams that
              contain complexing agents with cyanides, amines, ammonia (and its derivatives),
              EDTA, NTA, citrate, tartrate, oxalate and gluconate. Smaller quantities of organics can
              include oils and grease, solvents and metal finishing baths, which can also contain
              quantities of metals.

              In agriculture,  a small percentage of agricultural pesticides may contain arsenic,
              copper, mercury, manganese, lead, or zinc concentrations of heavy metals.  The
              metals accumulate  in soils by the repeated application of sludge over a long period of
              time. They can result, for example, in considerable movement  of zinc, and to a lesser
              extent, cadmium and  nickel to depths below 15 cm following surface applications.

              Atmospheric metal  deposition to ecosystems occurs primarily as precipitation
              (meteoric)  and dry deposition; in some ecosystems, particularly at high elevations,
              cloudwater may be a significant input of industrial emissions.  The relative contribution
              of precipitation, cloudwater, and dry deposition to a forest and the effect of the forest
              canopy on throughfall of metals and their chemistry vary depending on site factors
              including elevation, topography, and vegetation.  The relative contribution of  wet
              versus dry deposition may also influence the relative solubilities of metals and, in
              general, metals are less soluble in dry than in wet deposition.

              Additions of metals to soils and subsequent uptake from soils to plants is the major
              mode of entry into the tissues of plants, animals and humans.  The fate of heavy
              metals, including their mobility, absorptivity, and reactions in the soil,  and their
              subsequent uptake and distribution in edible plant parts is of critical importance in
              human health.  Soil contaminated with heavy metals can produce apparently normal
              crops that may be unsafe for human or animal consumption.  See knowledge frames
              on site vegetation for further information on vegetation-metal interactions.
Guide to Site and Soil Description               3.4

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                                                                         Site/Nature of Pollutants
               Permissible or "safe" levels of heavy metals, especially if used on farmland, are
               considered on the basis of several interrelated factors. Critical  levels of metallic
               contaminants that exhibit toxic effects on biota and the environment can often be
               related to the cation exchange capacity (CEC), with a higher CEC more closely related
               to toxic effects. See the section on cation  exchange and also the knowledge frame
               on soil CEC.

               Usually, depending on the geochemistry of the specific metal, the resistance to toxic
               effects of a nonacid, fine-textured  clayey soil can be several times the resistance of a
               coarse-textured or sandy, acidic soil. Loamy soils with approximately neutral pH may
               accumulate higher levels of heavy metals with much less risk to the environment,
               plants and animals. Generally, a chemical imbalance, such as from the addition of
               metal contaminants may result in alteration of soil properties, e.g., increase or
               decrease in Ph, Eh, cation exchange and biological activity, and decrease in mineral
               and organic adsorption complexes. See the knowledge frame on soil organic matter
               for further information  on soil organic matter and humus, and organo-metal
               interactions.

               Permissible or tolerable levels of heavy metals at a particular site should consider the
               interrelationships  of the following conditions and factors.

               1.  Initial trace element content of  soil as determined in noncontaminated off-
                 site  soil.
               2,  Total amount added of one particular element and of all heavy metals.
               3.  Cumulative total load of heavy  metals in the soil system.
               4.  Heavy metal dose limitation.
               5.  Equivalency of trace element toxicity to  plants as compared  to off-site plants.
               6.  Threshold values of trace element concentrations in soils.
               7.  Relative ratios between interacting heavy metal elements.
               8.  Soil characteristics, e.g., CEC,  pH, free  carbonates, organic  matter,  clay
                 content, structure, and moisture relationships.
               9.  Input-output balance, mobility and immobility.
               10. Plant sensitivity to  heavy metals in soils and  solution.

               The solubility  and therefore mobility of metal elements in soils depends considerably
               on complexing or chelation with organic  matter.  In the soil aqueous phase, organic
               compounds and water are the most abundant ligands, therefore hydrolysis and
               organic complexing are the most common  reactions.  These reactions are pH
               sensitive and  can be correlated with the size and charge of the cations. Higher ionic
               potentials usually indicate a higher degree  of hydration in the soil solution,  and
               consequently, easier precipitation.  Depending on the pH for the precipitation of metal
               hydrous oxides, the order of cation mobility in the soil solution under an oxidized
               system may decrease  as follows:
Guide to Site and Soil Description               3.5

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                                                                       Site/Nature of Pollutants
                   Divalent magnesium = divalent calcium > divalent mercury > divalent
                   manganese > divalent cadmium > divalent nickel = divalent cobalt = divalent
                   lead > divalent beryllium > divalent zinc = divalent copper > trivalent chromium
                   > trivalent bismuth > trivalent iron > trivalent tin.

              The transport of dissolved metal elements occurs in surface runoff, the movement of
              the soil solution and during leaching. Generally, in soils formed under a cool and
              humid climate, the leaching of metal elements downward through the  profiles is
              greater than their accumulation, unless there is a high input of these elements into the
              soils. In warm, dry climates, and also to some extent in humid hot climates, upward
              translocation of metal  elements in the soil profiles is the most common movement.
              However, specific soil  properties, mainly its cation exchange capacity,  control the rates
              of element  migration in the soil profiles.

              Depletion of metals and nutrients in soils is due mainly to their mobility downward with
              percolating waters through the profiles of freely drained acid soils and also their
              uptake by plants. On the positive side of the balance is the input of these elements
              and ions with atmospheric precipitation and their accumulation in particular soil
              horizons. An accumulation of metals usually occurs on the soil surface  or in surface
              horizons (A and O) and downward movement in the soil profile does not occur to any
              great extent unless the buffer capacity of the soil is overcome; soils have a finite buffer
              capacity for heavy metals. In acid soils, several elements, such as zinc, manganese,
              copper, iron, cobalt, and boron, are easily leached. These elements, however, are
              likely to form quite stable compounds if the  pH of the soil rises above  7.  Other
              elements, such as molybdenum and selenium, are mobilized in alkaline  soils, while in
              acid soils they become almost insoluble.

              Several detailed studies based on lysimetric experiments, and other research often
              using isotopic tracers, have yielded much information on element transport.  However,
              each soil profile with developed horizons has its own characteristic metal element
              movement  or nutrient.

              Adsorption is a common process for removal and immobilization of chemical elements
              and ions, including contaminant metals, from the soil solution onto soil particles. This
              process is  largely governed by the surface changes of soil particles and is caused
              primarily by ionic substitutions, mainly by soil colloids, especially collodial organic
              matter - the humus fraction.  At a low pH a positively charged surface prevails, while
              at a high pH a negatively charged surface develops. The colloids of the majority of
              soils, therefore, carry  negative charges and can be electroneutralized  by cations
              present in the surrounding solutions. In the presence of an excess of cations, the
              process of exchanging the cations for others maintains the electroneutrality of the
              system. Thus, the cations adsorbed by the soil solid phase can be replaced by other
              cations, most often  by hydrogen ions. An increase in stability of adsorbed metals may
Guide to Site and Soil Description              3.5

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                                                                        Site/Nature of Pollutants
               result from dehydration and recrystallization processes that occur on the surface of
               the colloids, especially in alkaline soils.

               The ability of the soil solid phase to exchange cations (cation exchange capacity -
               CEC), is one of the most important soil properties governing the cycling of metal
               elements and ions in the soil.  The excess amount of adsorbed cations compared to
               the amount in solution is interpreted as the buffering capacity of soils, while
               adsorption capacity  defines the amount of ions needed to occupy all adsorption sites
               per unit of mass.

               The CEC of different soils varies widely both in quantity and quality and can range
               from  1 to < 100 meq/100 g of soil. Surface properties of soil particulates are the most
               important factor in defining the capacity for adsorption of the microcations. Although
               total  adsorption processes cannot be related simply to CEC phenomena, the
               adsorbed amounts of cations are in accordance with the  CEC. Usually the soil solid
               phase with a large surface area, e.g., clays,  also shows a high CEC value and high
               adsorption and buffer capacities.

               The degree of  attraction or affinity of cations for adsorption, e.g., for ionic exchange
               sites, is closely related to ionic potential (charge/radius).  In some systems the metal
               ions  (zinc, cadmium and manganese) occupy nearly the same percentages of the
               CEC  as the various soil minerals.  Some cations, however, may have a higher
               replacing power than others and can be selectively fixed  by the sorbing sites.  See
               knowledge frame on cation  exchange capacity.

               In general, and depending on soil properties and their behavior in a number of soils,
               but not necessarily a specific soil or "type," mobile  and toxic heavy metals and
               metalloids may be categorized as antimony, beryllium, barium, mercury, nickel,
               selenium, tin, thallium and zinc.  Cyanide is also included in this section. See
               individual descriptions  for mobility and toxicity factors.  Also included here, but
               generally less toxic except under specific conditions, are aluminum,  boron, iron and
               manganese.  In general, cadmium, nickel and zinc are relatively mobile and are taken
               up by plants (see Tables 3-1 and 3-2). See knowledge frame on site vegetation and
               soil organic matter for additional information.

               Toxicity of a hazardous waste  site, as defined by EPA, refers to a toxicity determined
               by the Extraction Procedure (EP) Toxicity Test. The EP toxicity test is a laboratory test
               designed to simulate leaching of waste in a sanitary landfills.  A representative sample
               of waste is extracted and analyzed. If threshold levels of  eight metals and four
               pesticides and two herbicides are exceeded, and the extract contains one or more of
               the contaminants in  amounts equal to, or exceeding the specified levels, the waste is
               considered toxic and is classified as hazardous according to the EP Toxicity Test (see
               Table 3-3).
Guide to Site and Soil Description               3.7

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                                                                       Site/Nature of Pollutants
              The frequency of occurrence of metals and metalloids determined during preliminary
              site investigations and reported by Field Investigations Teams (FITs) for 436 sites is as
              follows:
                   lead > arsenic > cadmium > chromium > copper > mercury > nickel >
                   beryllium > manganese > silver > selenium
              Less than five sites were found to have antimony, barium, boron, cobalt, molybdenum,
              thallium, tungsten and vanadium.

              Antimony content in rocks is very small, usually < 5 ppm. It is enriched in sulfides,
              and during oxidation of sulfides enters into sediments and soils.  Argillaceous
              sediments may contain as much as 2 ppm.  As a metal, it is grey, lustrous and
              crystalline, appearing similar to metallic arsenic. The geochemistry and chemical
              behavior of antimony are closely related to that of arsenic, and secondarily to bismuth
              and phosphorus. Similar to arsenic, it is amphoteric, acting as both metal and
              nonmetal.  Antimony usually occurs in the trivalent form, but occasionally in the
              pentavalent form.  It is considered to be relatively highly mobile and can be
              associated with iron hydroxides.  Antimony compounds are much less toxic than
              arsenic compounds,  but more  so than bismuth compounds. In surface soils it ranges
              from 0.05 to 4 ppm.  In mature leaf tissues of various plants, it ranges from 7 to  50
              ppm.  Toxic or excessive limits are 150 ppm or more.  The average for antimony in
              soils is approximately 1 ppm.  Antimony, as for arsenic, may be found associated with
              nonferrous ore deposits.  It can be found around smelter operations and is
              considered to be a pollutant subject to long-range transport.  Antimony is a
              component of type metal;  and  both antimony and arsenic are used to harden lead
              alloys destined for lead shot, bullets, bearings,  battery grids and  cable sheathings.
              Whereas burning of arsenic forms arsenides, antimony yields stibnides.

              Beryllium is very toxic, indeed perhaps the most toxic, metal in the environment.
              There is more beryllium in soils developed from clays than from limestone or igneous
              rocks.  It resembles aluminum  in a number of properties.  Activity in soil  may resemble
              that of calcium and magnesium.  It is known to be strongly adsorbed in soil and
              occurs most often  in the divalent form. Its concentration in soils  ranges  from 0.1 to 40
              ppm, with a mean  of 10 ppm, but with concentrations higher near beryllium deposits.
              Although it appears to be rather immobile in soils,  its salts, such  as beryllium chloride
              and beryllium sulfate, can be adsorbed by plants, resulting in toxicity.  In various
              plants under natural conditions, its concentration ranges from 0.001 to 0.4 ppm.
              Beryllium is added to the soil in wastes such as rocket fuels; certain light, hard and
              corrosion-resistant alloys;  and  in ceramics. Concentrations are higher in soils near
              smelters and coal-fired power plants.

              Boron, a metalloid, is easily solubilized during weathering, forming several anions. It  is
              likely to be retained by clays, particularly illites, but also by sesquioxides and organic
              matter.  Its retention  is greater on sesquioxides than on  clay minerals. The most
Guide to Site and Soil Description              3.3

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                                                                        Site/Nature of Pollutants
               common form of boron in soil solution is boric acid, and in part, boric hydroxide.
               Boron solubility in soils may be governed by oxides of iron and aluminum. Organic
               matter has a strong influence on boron  mobility and availability, particularly in acid
               soils.  Boron reactions are highly pH dependent, especially when pH > 7.0.  In arid
               zone soils, boron is likely to be coprecipitated with magnesium and calcium
               hydroxides as coatings or stains on soil particles.  In soils, boron is considered to be
               the most mobile element among the micronutrients, and therefore follows the
               movement of water in the soil profile.  In cool humid regions it is readily leached,  but
               in warmer areas it may concentrate in the surface horizons. It also may concentrate in
               soil horizons enriched with illite.  Some soils of arid and semiarid regions  may contain
               toxic levels of boron. Some sewage sludges and fly ash also may add significant
               boron contamination to the soil.  Soluble forms of boron are easily taken up by plants.
               The soil pH is the most important factor affecting availability to  plants.  In  alkaline
               soils, the availability of boron increases  with an increase in soil pH, which increases its
               potential for toxicity, especially with available water, either rainfall or irrigation.  The
               normal content  of boron in various mature plant leaf tissues is 10 to 200 ppm.
               Depending upon the plant species or crop, boron toxicity varies from approximately
               250 to 5,000 ppm, usually >  500 ppm.  The common range in soils is 2 to 100 ppm.
               Other than sewage sludges, boron contamination in soils can result from wastes such
               as aluminum alloys, steel and electrical wires, fiber-reinforced materials and aircraft
               parts.

               Cadmium  in natural soils is largely dependent on the chemical  concentration of the
               parent rock.  Cadmium is concentrated  in argillaceous and shale deposits. It is
               strongly associated with zinc in its geochemistry.  It exhibits a higher mobility than
               zinc in acid environments.  During weathering, it is readily solubilized to the divalent
               form  but also forms  complex ions and organic chelates. The most important factors
               concerning its mobility are pH and Eh.  Above pH 7.5 cadmium is not readily mobile
               in soils.  In acid soils, the organic matter content and sesquioxides may largely control
               mobility. Cadmium is most mobile in acid soils at pH 4.5 to 5.5.  It is rather immobile
               in alkaline soils.

               Cadmium  is one of the most  hazardous of the heavy metal soil pollutants  to human
               health and is easily taken up by some plants.  In mature leaf tissue of various plants,
               the normal range is  0.05-0.02 ppm;  excessive or toxic levels range from 5-30 ppm.
               The amount of cadmium in soils is usually <1  ppm. Cadmium  is added to the soil in
               wastes from alloys, fungicides, enamels, batteries, pigments, plastics, old  motor oil,
               textile manufacturing, electroplating and rubber.  Sewage sludges and some
               phosphate fertilizers also can be important sources of soil cadmium contamination.
               The principal use of cadmium is as an electroplated coating on fabricated steel and
               cast iron parts for corrosion protection; it is usually plated from a cyanide bath.
Guide to Site and Soil Description               3.9

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                                                                        Site/Nature of Pollutants
               Cyanide, neither a metal not a metalloid, is listed among the priority pollutants by EPA
               along with metals and asbestos. It may occur in metal-contaminated soil sites.
               Cyanides are extremely poisonous, readily reactive, and volatile, as hydrogen cyanide
               gas.  In aqueous solution, cyanide forms hydrocyanic acid.  Neutralization with bases
               (alkaline caustics such as sodium hydroxide) forms cyanide salts.  The cyanide ion
               forms very stable complexes with a number of metals including titanium, vanadium,
               chromium, manganese, iron, cobalt, nickel, copper, molybdenum, palladium, silver,
               platinum and gold.  Cyanides are highly toxic and act very rapidly. As a poison,
               cyanide functions very much like carbon dioxide.  Hydrogen cyanide is the most used
               cyanide compound in industry. It is used in the extraction of silver and gold ores, to
               treat the surface of iron and steel, for electroplating of zinc,  copper, brass, cadmium,
               and to a lesser extent, gold and silver, and certain other industrial processes, and as
               a pesticide for insects and rodents.  Primarily, cyanide is used as a chemical
               intermediate in the production of methacrylates.

               Manganese is accumulated in sediments and soils.  Manganese is not generally
               considered to be a polluting metal in soils  but its concentration can be increased
               when sludge is applied to soils.  Its solubility in soils is highly dependent on pH and
               Eh; its mobility in soils depends entirely on its oxidation-reduction potential.  In
               exceptional soils - those with a reducing environment, such as acid and peat bogs,  it
               occurs as the bivalent form and migrates easily in the soil solution.  The readily
               available and mobile bivalent form includes compounds that exist in soil solutions as
               carbonates, bicarbonates, sulfates and other easily soluble salts in acid soils up to pH
               4.6.  Hydrous oxides of manganese, as well as those of aluminum and iron are
               common in soils. They are found as crystalline minerals or as surface coatings and
               stains on other minerals. The hydrous oxides of both manganese and iron are very
               unstable because they are formed under oxidizing conditions, but dissolve under
               reducing conditions.  The bivalent form in solution is difficult to oxidize.

               Manganese forms trivalent compounds that are less mobile.  In regions with a high
               oxidation potential, e.g., sandy and rocky deserts, and in the absence of organic
               matter and the action of solar radiation (sunlight) and other catalysts, bivalent
               manganese is changed to the quadravalent form, which is easily soluble in water and
               weak acid  and can form concretions, hardpans, and stains,  either separately or in
               combination with iron. Geochemistry of manganese hydroxides is closely related to
               behavior of iron hydroxides. Cross-interactions occur during redox reactions.  It is
               particularly concentrated in soil horizons enriched with iron oxides and hydroxides.
               Organisms have an important role in the migration of manganese. Plants with long
               roots extract it from the subsoil.  It is accumulated in the upper (0 and A)  horizons
               and in litter (fallen  leaves).  The distribution of manganese in the soil profile varies with
               thermic region. Many organisms, especially aquatic species, have the ability to
               concentrate manganese.  Oxidation of bivalent manganese, and the reduction of high
               valence manganese compounds, is attributed largely to the activity of organisms.
Guide to Site and Soil Description              3-10

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                                                                        Site/Nature of Pollutants
               Concentrations of manganese in surface soils generally vary from 1500 to 3000 ppm.
               Normal or sufficient levels in mature leaf tissues of various plant species ranges from
               20 to 300 ppm; excessive or toxic levels range from 300 to 500 ppm. Manganese is
               used in steel, alloys, paint, dry cell batteries, glassmaking, metal treatment and as a
               chemical oxidizing agent.

               Nickel has an unclear biochemical function, but is highly toxic to plants.  In mature
               leaf tissue of various plants, the normal range is 0.1-5 ppm; excessive or toxic levels
               range from  10-100 ppm. In soils, it ranges from approximately 3.0 to 300 ppm and
               occurs primarily in the bivalent form.  In sediments it is associated with iron and is
               absorbed on silicates.  Nickel hydrates begin to form when the pH of the soil solution
               reaches pH 6.8.  There are water-soluble compounds of nickel in soils.  The amount of
               water-soluble nickel depends not only on the soil pH, but also the character of the
               subsoil.  The vertical distribution of nickel in the soil profile is similar to that of iron.
               Total content in soil solution is -0.005 to 0.05 ppm.  Nickel contamination of soil
               results from wastes such as batteries, paints, cosmetics, pigments, electroplating
               solutions, lacquers, cellulose compounds, steel and alloys, spark plugs and gasoline.
               The most important industrial use of nickel is as a hydrogenation catalyst, such as
               Raney nickel. The second largest  use  of nickel is in electroplating.

               Tin in common rocks has the highest concentration in argillaceous sediments. Tin in
               soils is largely derived  from the bedrock. It occurs in the divalent and quadravalent
               forms. Mobility during weathering  is highly pH dependent. The divalent form is a
               strong reducing agent and is present only in acidic, reducing environments. Soluble
               tin has a behavior similar to that of iron and aluminum, including their hydroxides. It
               can form both soluble and insoluble organic complexes.  Tin is fairly evenly distributed
               in the soil profile.  Increased concentrations may be found in peats.  Measurable tin is
               not found in all plant species.  Tin  is very toxic to both higher plants and fungi.  Plants
               and crops grown on tin-contaminated soils can accumulate it. Mosses and sedges
               have been found to be excellent tin accumulators.  Excessive amounts in mature  leaf
               tissues may be approximately 150  ppm. The common range of tin in soils is 50 to
               300 ppm. Higher values are found near tin mines and smelters. Tin wastes can
               include tin plating solutions used in the production of tinplate, and low-carbon steels
               and alloys coated with tin to reduce corrosion.

               Thallium content  of soils increases with weathering of acidic igneous rocks and
               increasing clay content of sedimentary  rocks. In geochemical environments, thallium
               occurs in three oxidation states.  The monovalent cation can be highly associated with
               potassium and rubidium.  During weathering processes, thallium becomes readily
               mobile, but  it is most often adsorbed by clays and gels of iron and manganese
               oxides.  It can also be  adsorbed by organic matter,  especially under reducing
               conditions; higher concentrations of thallium may be found in surface rather than
               subsurface soils.  The thallium concentration of plants is related to its concentration in
Guide to Site and Soil Description              3-1 -)

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                                                                       Site/Nature of Pollutants
              soils. Increased thallium levels in plant tissues are highly toxic to plants as well as
              animals and humans. Nitrate formation is inhibited in soils polluted with thallium.
              Normal concentrations of thallium in edible plants may range from 0.008 to 0.126
              ppm. Herbaceous plants grown in thallium-enriched soils may accumulate > 100
              ppm. Microorganisms may be relatively sensitive to thallium. The average thallium
              concentration for a number of soils is 0.1 ppm. Much higher concentrations are
              recorded near potassium fertilizer plants, smelters, and bituminous coal sites. Coal
              combustion is the principle source  of anthropogenic contamination; heavy metal
              smelting and refining processes also release some thallium into the environment.
              Thallium compounds are used as pesticides, rat and ant poisons, in thallium mercury
              alloys, in the medical profession, as an ore-floating solvent, in low-melting  glasses and
              semiconductors, and in fireworks.  It is obtained as a flue-gas by-product during the
              production of sulfuric acid.

              Mercury is strongly bound to  humus, and is more strongly adsorbed under acid
              conditions. Strong interactions occur between mercury compounds and soil
              constituents.  Its oxidation state is highly dependent on the soil redox potential.
              Through microbial transformations, metallic mercury can be  readily converted to
              methylated or ethylated  mercury.  Methylated mercury (e.g.,  alkylmercury)  will
              accumulate in the food chain  and pose a resultant serious health hazard.  Plants
              appear to have the ability to easily  absorb mercury from solutions. It also  appears
              that increases in the concentration of mercury in the soil also increases its
              concentration  in plants.  Plants can also adsorb mercury vapor.  Symptoms of
              mercury toxicity include  stunting of seedling growth,  reduced root development and
              inhibition of photosynthesis.  Displacement of mercury is more important in the vapor
              phase, where  it is lost through volatilization.  Amounts of mercury volatilized from the
              soil appear to be affected by  the solubility of the mercury compound added to the
              soil. Volatilization is inversely related to soil sorption capacity and therefore texture,
              with losses from sand greater than those from loam, and more from loam than from
              clay.  The common range of mercury in soil is 0.1 to 0.3 ppm.  Mercury is  added to
              the soil in wastes such as batteries, paints, plastics, fungicides, Pharmaceuticals,
              paper products, manufacturing of electrical apparatus, and products of catalytic
              processes. The primary use  of mercury is in electrical applications, secondarily in the
              electrolytic production of chlorine and sodium hydroxide.

              Selenium, a nonmetal resembling sulfur in chemical properties,  can have a metallic
              appearance but rarely occurs in the elemental form unless soil Eh is low.  Most
              selenium in soils is in association with iron hydrates and concentrated by them.
              Normally,  soils not derived from selenium-rich rock contain only a few ppm selenium.
              Toxic levels are reached at 5  to 10 ppm.  In humid climates, selenium can be oxidized
              to the tetravalent form and  readily migrates to ground waters.  However, selenium in
              soil solutions is frequently reduced and can be precipitated  in lower horizons.
              Selenium  is least soluble under acid soil conditions.  In acid soils selenium is
Guide to Site and Soil Description              3-12

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                                                                         Site/Nature of Pollutants
               precipitated by ferric hydroxide and is probably a factor in reducing its mobility.  Some
               western U.S. soils have toxic levels of selenium following successive years of irrigation,
               and selenium has migrated along with surface runoff and discharges.  Lack of rainfall
               in arid areas may prevent the removal of selenium,  but irrigation and leaching can
               lead to toxic levels in plants and waters and can be dangerous for animal life;
               selenium accumulation in plants may reach -15,000 ppm.  In mature leaf tissue of
               various plants, the normal range is 0.01-2 ppm; excessive or toxic levels range from 5-
               30 ppm.  The common range of selenium in soils is 0.1 to 2 ppm.  Selenium
               contamination occurs from wastes such as paints, pigments, and products of the
               electrical industry.  Half of the selenium produced is used in the decolorization and
               production of colored glass, and  in the production of calcium sulfide selenium
               pigments which are primarily used in plastics.

               Zinc is usually associated with cadmium in naturally occurring soils.  Its content in soil
               depends not only on the  nature of the parent  rocks and content of organic matter, but
               also on soil texture and pH.  It is  not as toxic as cadmium.  Retention time of zinc in
               soils is similar to that of copper and is probably also greatly affected by the
               preferential uptake by vegetation.  Zinc is considered to be relatively soluble and
               mobile compared to other heavy metals in soils. It is most readily mobile and
               available in acid light mineral soils.  It may exist in excessive concentrations in some
               acid soils, leading to greater mobility.  The zinc fraction associated with iron and
               manganese oxides is likely to be the form most available to plants.  Acid leaching is
               important in zinc immobilization, with losses of this metal observed in certain soil
               horizons. Soluble zinc-organic complexes and complex anionic forms of zinc may
               account for the relative solubility and availability of zinc in soils with a high pH. Zinc
               content in soils is on the  average twice that of copper and it is more uniformly
               distributed in soils than copper. Sewage sludge may be high  in zinc.  Zinc commonly
               occurs in soils at levels of 10 to 300 ppm, usually 30 to 150 ppm. In mature leaf
               tissue of various plants, the normal range is 27-150 ppm; excessive or toxic levels
               range from 100 - -400 ppm. Zinc is toxic to plants  at -400 ppm (dry weight).  Certain
               endemic plant diseases can be attributed to the zinc content of soils.  Zinc
               contamination in soils can result from additions of wastes such as paints, alloys,  metal
               coatings, cosmetics, copying paper, rubber, linoleum and glass.

               Other  toxic metals or metalloids can include barium, and aluminum. Barium is toxic
               only in extreme conditions (e.g., barite mines).  Aluminum, along with iron and
               manganese, can be toxic in acid soils. In general, almost any  soil element is toxic to
               plants where it is present or available in abnormally high  concentrations, restricts
               growth or is adsorbed by the plants, resulting  in high tissue concentrations.  Make
               comparisons with off-site  concentrations in both plants and soils.
Guide to Site and Soil Description              3.13

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                                                                        Site/Nature of Pollutants
VALUE:        Relatively nonmobile and nontoxic

DEFINITION:    Residence time of the heavy metal in either the solid or liquid phase is relatively long,
               thereby generally decreasing potential toxicity.

CONDITIONS:  Concentrations are found primarily as sorbed or fixed cations on soil minerals and
               organic matter and are dependent on soil properties such as pH and  Eh.  Mobility,
               and resultant toxicity, are therefore decreased or limited,  unless soil particles are
               ingested. The metals or metalloids categorized here are  arsenic, chromium, cobalt,
               copper, molybdenum, and silver. See individual descriptions for mobility and toxicity
               factors.

               Arsenic is rather uniformly distributed in major rock types and has a great affinity to
               form or occur in many minerals.  In contaminated soils, arsenates, such  as from
               pesticides (sodium arsenate and arsenic trioxide) and sewage/industrial and mine
               wastes, are fixed in soils in a relatively insoluble state, and are not lost by leaching;
               they may accumulate.  Arsenic can be troublesome in old orchards; concentrations of
               2 ppm can  be injurious to seedlings.  Most plants contain <0.5 ppm (dry weight) of
               arsenic, but they may accumulate as much as 14 ppm.  Mushrooms can accumulate
               relatively  high concentrations of arsenic and can serve as "indicator" plants.  Excessive
               or toxic ranges in various plants are 5-20 ppm. The arsenic content for  a number of
               soils ranges from approximately 1 to 60 pm.  The lowest  arsenic levels are found in
               sandy soils, and particularly those derived from granites.

               Arsenic minerals and compounds are readily soluble,  but migration is greatly limited
               because  of strong adsorption by clays, organic matter and hydroxides.  The mobility
               of arsenic in soil has been shown to be proportional to the amount of arsenic added,
               and inversely proportional to its residence in the soil and iron and aluminum content.
               The toxicity of arsenic depends considerably on the concentration of soluble arsenic.
               Yellow arsenic and arsenic compounds are highly poisonous if ingested. Arsenic is
               less toxic in soils with sufficient phosphorus.  Sodium arsenate and arsenic trioxide,
               formerly used in herbicides, are the most toxic.  Plant toxicity (phytotoxicity) of arsenic
               is highly dependent on soil properties. In heavy (clayey) soils, it has been found that
               very significant growth reduction occurs  at 1000 ppm, but in light (sandy) soils, 100
               ppm is equally toxic. Oxidation state of arsenic in soils is highly dependent on the
               redox potential.  In heavy gley soil,  arsenic is accumulated only in the top horizon. It
               is readily leached from the subsurface with a high reduction potential. In
               uncontaminated soils, the distribution of  arsenic in the soil profile is highly variable.
               Other than  pesticides, arsenic is found in wastes from a wide variety of processes and
               products: enamels, pigments, alloys,  ceramics, lubricating oils, wood preservatives,
               fireworks, glass, printing and tanning processes, semiconductors and
               photoconductors. The major use of arsenic which results in hazardous  wastes is the
               production  of various chemical intermediates, secondarily for wood preservatives.
Guide to Site and Soil Description
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                                                                        Site/Nature of Pollutants
               Chromium pollution of soils is seldom a problem except in mining and processing.  It
               is not essential in plant nutrition and is rarely taken up by plants at usual prevailing
               soil pH and Eh (oxidation-reduction) values.  Chemical forms of chromium in soil
               solution are not exactly known but it is expected that at  pH range 5-7, most of the
               chromium is in the chromate form and would be complexed with various soil organic
               ligands. During disintegration and weathering of rocks,  the trivalent form has little
               mobility, being similar to ferric iron.  Under highly oxidizing conditions, such as in
               some hot desert soils, hexavalent chromate may form which is readily soluble, but this
               is an unusual phenomenon.  Chromium is concentrated mainly in ultrabasic rocks,
               and particularly in serpentine-derived (magnesium silicate) rocks.  The distribution of
               chromium in soils tends to follow that of iron. At low concentrations at low pH (< pH
               4), it has little effect on plants, but in solution at high concentrations it can stop plant
               development. Most of the chromium absorbed by plants is retained in the roots.  In
               mature leaf tissue of various  plants, the normal range is  0.1-0.5 ppm; excessive or
               toxic levels range from 5-30 ppm. Chromium can be toxic to humans, especially if
               inhaled. At most soil pH and Eh levels, hexavalent chromium is reduced to trivalent
               chromium.  Hexavalent chromium predominates at pH 6 and as dichchromiate ions at
               pH 2 to 6. Trivalent chromium is the stable form in soils. Industrial chromium
               includes organically complexed trivalent chromium which may remain mobile in soils.
               It is mobile in the hexavalent form, and can be highly toxic in this form.  The reduced
               trivalent form  is less mobile.  Hexavalent chromium is the major form of chromium
               used in industry.  It is found  in wastes such as steel and other alloys, chrome plating,
               electroplating, varnishes, dye fixers, corrosion inhibitors, photography emulsions and
               defoliants. Sodium dichromate is the primary raw material for the production of other
               chromium chemicals, both trivalent and hexavalent forms.  These compounds are
               largely used for chromic acid and chrome pigments.

               Cobalt is associated with various iron minerals and in geochemical cycles, it closely
               resembles iron and manganese.  Its distribution in sediments in the soil profile is
               strongly related to manganese oxides. Cobalt sorption on soil particles/clay minerals
               is preferential. It is fixed or combined with large  molecules such as in humus.
               Trivalent cobalt forms complex organic compounds and  is dispersed through soils in
               the crystal lattices of  aluminosilicate minerals.  Hydrates of cobalt form when the pH of
               the soil solution reaches pH 6.8.  The amount of available cobalt is related to the
               amount of available (acid-soluble) iron.  There are some water-soluble compounds of
               cobalt in soils, but the amount available also  depends on soil  pH and subsoil
               characteristics.  Cobalt accumulates in the  humic horizons of many soils. It  is easily
               solubilized and mobile in peaty soils.  The vertical distribution  of cobalt in the soil
               profile is similar to that of iron.  In mature leaf tissue of various plants, the normal
               range is 0.02-1 ppm;  it can be toxic to plants.  Excessive or toxic levels range from  15-
               50 ppm, approximating those levels which are considered excessive in soils.  Cobalt
               and its salts are obtained chiefly as by-products  in the metallurgy of nickel.  It is found
               in steel and alloys and is widely used in catalytic processes.
Guide to Site and Soil Description              3.-) 5

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                                                                       Site/Nature of Pollutants
              The content of copper in natural soils depends largely on the nature of the parent
              rock.  The most important sources of copper in soils are copper-bearing sandstones
              and deposits of copper minerals, e.g., malachite, chalcopyrite, etc.  Copper is toxic to
              most plants in soil solutions exceeding 0.1 ppm; the oxidized form is the nutrient
              source for plants; solutions > 20 ppm can be toxic to animals; solutions of 1.0 ppm
              are safe for drinking water;  normal soils are -20 ppm. Mobility and displacement of
              copper is low because of its strong bonding with organic matter and clay minerals. It
              is principally complexed with organic compounds of low molecular weight. If the soil
              organic matter undergoes anaerobic (reducing) decomposition, copper can be
              released in the monovalent (cuprous) state; under aerobic (oxidizing) conditions,
              copper can be released in the divalent (cupric) state. Root tissues have a strong
              ability to retain copper.  The retention time for copper in soils is much shorter than for
              lead, despite similar heavy metal-organic matter constraints, probably due to
              preferential uptake as a  micronutrient by plants. In mature leaf tissue of various
              plants, the normal range is  5-30 ppm; excessive or toxic levels are 20-100 ppm.
              Some lichens occur on substrates high in copper.  Surface soils have a great ability to
              accumulate copper.  The average range in soils is 2-100 ppm. Copper contamination
              in soils results from agricultural copper-containing  materials such as fertilizers,
              pesticide sprays,  agricultural or municipal wastes and industrial emissions.

              Lead occurs naturally in soils  from the composition of the parent rocks, but it may
              accumulate in the surface horizons of soils and organic  matter, particularly in soils
              along roads from traffic exhausts,  from lead-zinc smelters, from use of old insecticides,
              and from dumps  and other sites receiving industrial/household lead (e.g., old paints,
              batteries).  Mobility of lead in  soils and plants tends to be low; in soils it is considered
              to be the least mobile among the  heavy metals and on the basis of mobility would not
              be considered toxic.  Lead  occurs mainly in the divalent form. It has the ability to
              replace potassium, barium, strontium and calcium  in soil mineral and adsorption sites.
              More lead is naturally found in surface organic soils than in mineral soils, and
              therefore migration can occur more  easily than in mineral soils. Organic matter should
              be considered the most important sink of lead in contaminated soils. Natural soils
              may contain as much as 10 ppm total lead.  Lead  can cause diseases in animals, and
              although lead is a serious health hazard,  uptake is by surface contamination and by
              accidental  ingestion of contaminated soil; crops, and grasses (eaten by animals), and
              not by plant uptake.  Normal  lead levels in various plants range from 0.5 to 3 ppm.
              Some  lichens occur on substrates high in lead.  Roadside concentrations may be as
              high as 2400 ppm. Waste dumps may contain lead from old paints, batteries,
              pesticides, solder, glass, brass, bronze, pigments and ammunition.

              Molybdenum is higher in soils derived from granite and  shale. Molybdenum is usually
              deficient in most  U.S. soils. Mobility depends largely on soil pH, Eh, organic matter,
              humus, drainage, and other factors.  Molybdenum in wet alkaline soils is most easily
              taken up by plants.  Easily  mobile anions are readily coprecipitated by organic matter
Guide to Site and Soil Description              3.16

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                                                                        Site/Nature of Pollutants
               and calcium carbonate.  It is least soluble in acid soils and readily mobilized in
               alkaline soils. Differential adsorption of molybdenum by iron, aluminum and
               manganese hydrous oxides contributes to the retention of molybdenum in surficial
               deposits. Its solubility decreases with time.  Plants take up molybdenum mainly as
               molybdate ions.  Its absorption is proportional to its concentration in the soil solution
               and is a function of soil pH, especially  pH 6 to 8.  Plant uptake is increased at sites
               contaminated with  molybdenum.  Toxicity symptoms are definitely apparent in plants
               at >  200 - 300 ppm (dry matter),  although lower levels of 10-15 ppm have also been
               found to be toxic or excessive. Toxicity symptoms in plants under field conditions is
               rare.  The normal range in mature leaf  tissue of various plants is from 0.2-1 ppm. In
               surface soils, the usual range for  various soils is 0.8 to 3.3 ppm with a mean of 2.0
               ppm, closely resembling that of the parent rocks. Molybdenum is used in steel
               making and in magnets,  such as  telephone receivers.

               Silver is easily released by weathering  and is then precipitated in alkaline  reduction
               potential media or in media enriched with sulfur. Its geochemical characteristics are
               similar to those of copper. Its concentration in rocks is less than 1,000 times that of
               copper. It forms several complexed anionic and simple cationic species.  Despite
               several mobile complexes, it is relatively immobile in soils at >  pH 4.0. Humic
               substances absorb and complex  silver, which can lead to an enrichment of surface
               soils  (A and O horizons).  Silver concentrations differ greatly among plant species and
               times of sampling.  The amount of silver absorbed by some higher and lower plants
               can be related to the amount of metal  in the soil.  It can be concentrated to toxic
               levels in plants growing in silver-mineralized areas. Silver in mature leaf tissues of
               various plant species is usually approximately 0.5 ppm.  Excessive  or toxic levels
               reach 5 to 10 ppm. The common range of silver in soils is 0.03 to 0.09 ppm. Silver
               contamination of soil can result from photographic and electroplating wastes and
               mirror manufacturing.  Silver is primarily consumed in the form  of silver nitrate and
               silver halides for photographic processes, as silver cyanide complexes and for
               electronic product contacts and conductors.  Because silver is  a precious metal,
               usually every economic effort is made to reclaim it before products are disposed.

               Make comparisons with off-site concentrations for all suspected abnormal
               concentrations in total  soils or soil solutions; determine mobility and uptake, if
               necessary.

               Table 3-1 below summarizes the ranges of metals considered to be excessive as
               compared to analyses  obtained for  many uncontaminated soils and various  plants.
               Specific soil, soil solution, soil extract, plant analyses and toxicity tests with metal
               species are needed for these determinations. Table 3-2 provides information on the
               toxicity  of a simulated solid waste leachate (USEPA, 1982).
Guide to Site and Soil Description              3.-) 7

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                                                                        Site/Nature of Pollutants
               Table 3-1.  Concentration of Metals and Nonmetals (Trace Elements)
                           Considered to be Phytotoxically Excessive
       Levels in Surface Soils and Various Plants in ppm Air Dry Weight (10,000 ppm = 1 %).a
Element
Antimony (Sb)
Arsenic (As)
Beryllium (Be)
Boron (B)
Barium (Ba)
Cadmium (Cd)
Cobalt (Co)
Chromium (Cr)
Copper (Cu)
Mercury (Hg)
Manganese (Mn)
Molybdenum (Mo)
Nickel (NO
Lead (Pb)
Selenium (Se)
Silver (Ag)
Thallium (Tl)
Tin (Sn)
Zinc (Zn)
Surface Soilb
Acid-Neutral
5-10
100-1000
> 10
30-100
30-100
3-10
30-50
2-10
20-100
1-5
3000-8000
5-10
30-100
50-100
5-10
> 2
...
> 50
200-400
Relatively Relatively
Plant0 Mobiled Toxicd
150 +
5-20
10-50 - +
>500 +
50-200
5-30 + +
15-50
5-30
30-100 +
1-3 + +
300-500 +
10-50
10-100 - +
30-300 - +
5-30 + +
5-10
>20 + +
>60 +
100-400 + +
                   After A. Kabata-Pendias and M. Piotrowska, 1983, and A. Kabata-Pendias and H.
                   Pendias,  1984.
                   Range for coarser textured and acidic soils (CEC=5-10 meq/100 g), and for
                   clayey, finer- textured, and more neutral soils (CEC= 10-20 meq/100 g),
                   respectively.
                   Range for premature plant tissue for various species that are not sensitive or
                   have developed tolerance.
                   Relative mobility in soils and toxicity to plants, animals or humans.  Metal and
                   metalloid species vary in their mobility and toxicity depending on their form (ion),
                   and related factors of soil pH-Eh, texture, structure,  mineralogy, oxides and
                   hydroxides, presence of various cations and anions, organic matter content,
                   temperature, moisture content and  potentials, porosity, microbial abundance,
                   kinds, activities, etc.  See knowledge frame on nature of heavy metal soil
                   pollutants for comments on specific metals and metalloids.
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                                                                      Site/Nature of Pollutants
       TABLE 3-2 BEHAVIOR OF METALS DURING VARIOUS WEATHERING PROCESSES3'"
 Degree of
 Mobility           Soil pH-Eh
                         Metals and Metalloids
 High
Oxidizing and acid

Neutral or alkaline
Boron
                                            Boron and selenium
 Medium
Oxidizing and acid

Mainly acid

Reducing with
variable potential
Molybdenum, selenium and zinc

Cadmium, cobalt, copper, mercury and nickel

Arsenic, cadmium, cobalt, chromium,
iron, manganese and tin.
 Low
Oxidizing and acid

Neutral or alkaline
Barium, beryllium and iron

Barium and beryllium
 Very low
Oxidizing and acid

Neutral or alkaline

Reducing
Chromium

Silver, copper, cobalt, nickel, thallium and mercury

Silver, barium, beryllium, cobalt, copper, boron,
mercury, molybdenum, nickel, selenium and zinc.
                   After A. Kabata-Pendias and H. Pendias, 1984.
                   The mobility of these elements during weathering processes is determined (1) by
                   the stability of the parent minerals and (2) by the electrochemical properties of
                   the elements.
Guide to Site and Soil Description
                         3-19

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                                                                     Site/Nature of Pollutants
       TABLE 3-3 EPA TOXICITY LEVELS OF EXTRACTED HAZARDOUS WASTE SAMPLES
                     CONTAINING METALS, METALLOIDS AND ORGANICS3
 Compound
          Maximum Concentration (mg/L)
 Arsenic
 Barium
 Cadmium
 Lead
 Mercury
 Selenium
 Silver
 Endrin
 Lindane
 Methoxychlor
 Toxaphene
 2,4-D (2,4-Dichloro-
  phenoxyacetic acid)
 2,4,5-TP Silvex (2,4,5-
  Trichlorophenoxypropionic acid)
                       5.0
                      100.0
                       1.0
                       5.0
                       0.2
                       1.0
                       5.0
                      0.02
                       0.4
                      10.0
                       0.5
                      10.0

                       1.0
                  US EPA, 1982. Test Methods for Evaluating Soil Waste - Physical/Chemical
                  Methods, 2nd ed.  Office of Solid Waste and Emergency Response, Washington,
                  D.C.

                Toxicity levels for heavy metals not included on the above EPA List
                                    include the following:
Compound
Beryllium
Cobalt
Copper
Iron
Manganese
Molybdenum
Nickel
Tin
Zinc
Maximum Concentration (mg/L)
2.0
5.0
0.1
5.0
3.0
40.0
5.0
300
1.0
The California List of regulations banning land disposal of specified hazardous wastes or liquid
hazardous wastes (including free liquids associated with any solid or sludge), requires that they
cannot contain > 1,000 mg/l of free and complex cyanides.
Guide to Site and Soil Description
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                                                                     Site/Climate and Weather
OBJECT/ATTRIBUTE: SITE/CLIMATE AND WEATHER

DEFINITION:   Climate:  the average course or condition of the weather for the site and region over a
              period of years as exhibited by temperature, meteoric precipitation, and wind.
              Weather: the state of the atmosphere at the site and region during the time of study
              with respect to heat or cold, wetness or dryness, calm or storms,  clearness  or
              cloudiness, and barometric pressure.

VALUES:      HUMID
              TEMPERATE
              DRY

CATEGORY:   SITE BACKGROUND

PROPERTIES:  INPUT FACT

REFERENCES: Koeppe and Delong, 1958
              National Climate Data Center, 1983
              Shaw, 1967
              Stephens and Stewart, 1964
              Thornthwaite and Mather, 1957
              Trewetha and Horn, 1980
              USDA Soil Conservation Service, 1970, pp. 27 - 28
VALUE:
DEFINITION:
Humid
A general category for a climatic regime that is usually hot or warm and not dry for
more than a 2-month period.  Weather usually rainy.
CONDITIONS:  Climate and weather-related measurements for a site are important in regard to soil
              and plant development, weathering, fate, transport and deposition of contaminants,
              effects on field instruments (their operation and measurements), and sampling.
              Weather and/or meteorological measurements related to the site include cloud cover -
              its nature, extent and duration and as it affects solar radiation, absorptivity and
              reflectivity, temperature, precipitation (meteoric), barometric pressure, humidity
              (relative humidity), dew, wind direction and velocity. Additional site measurements,
              which can characterize the site can include evaporation rate and its relationship to
              diffusion, volatilization and evaporation of water or liquid chemicals and contaminant
              solutes from the soil surface, evapotranspiration and net thermal exchange, which are
              soil-plant (and animal) - microclimatic relationships. Also see knowledge frame for
Guide to Site and Soil Description
                             3-21

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                                                                      Site/Climate and Weather
              wind direction and velocity, temperature, temperature regime and vegetation, macro
              and mesofauna.

              Climate, interacting with parent materials and vegetation, is an overriding factor in soil
              development, formation and resultant properties (e.g., high organic matter, leaching,
              and high acidity).  Usually, there is a resultant dense vegetation of trees and shrubs or
              grasses at constant temperatures and increase in moisture; both plant growth and
              clay content will increase.  At constant moisture, the clay content increases along with
              plant growth. Soil sampling is difficult because of vegetation,  either because of
              surface growth or roots, surface litter, or organic matter except in cleared areas and
              where soil structure has been altered or destroyed by soil disturbance such as
              through crust formation, puddling, compaction, etc. Sampling also may be difficult if
              soil is wet. Removal of vegetation increases soil temperature evaporation and net
              thermal exchange  and reduces soil moisture, especially in the tropics. Much of water
              and chemicals will percolate through the soil with considerable leaching of soluble
              minerals and metal ions.
VALUE:
Temperate
DEFINITION:    A climate regime common in middle latitudes, affected by either ocean or continents,
               westerly winds and rain in all seasons, or winter snow.
CONDITIONS:  Climate is still an important factor in soil formation, although forests may be less
               dense and extensive grasslands may be present. Soils are less leached than are
               those in humid regions; they exhibit less (but still significant) organic matter and
               moderate percolation.  A moderate amount of water and chemicals are subject to
               leaching and percolation through the soil. Weather may vary seasonally and diurnally.
               Check with local weather station before sampling for temperature, wind, and meteoric
               precipitation (rain).
VALUE:        Dry

DEFINITION:    A dry climatic regime not dependent on temperature, where a deficiency of
               precipitation is the dominant climatic characteristic.

CONDITIONS:  Arid, semi-arid, and desert types are found. The boundary separating hot from cold
               dry climates is the isotherm of 8 months with a temperature of
               10°C (50 °F) or above. There may be a short moist season, meager rainfall during
               most of the summer, or the region may be constantly dry.
Guide to Site and Soil Description
                              3-22

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                                                                       Site/Climate and Weather
               Climate has less effect in soil formation than other factors; parent material and
               minerals are predominant factors.  Most of the retained water or chemicals are held by
               the soil minerals. There is very little or no leaching; soils are generally alkaline. Trees,
               shrubs, and grasses are sparse or scattered except in favorable habits, with xeric
               varieties, or non-existent in extreme dryness or where removed through human or
               animal activities.  Erosion and rapid runoff are noticeable.  Transport of surface
               chemicals is largely dependent on sudden downpours and on management practices.
               Check with local weather station in case inclement  weather is expected at time of
               sampling. Sampling also may be difficult if  soil is too hard.
Guide to Site and Soil Description              3.23

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                                                                                  Site/Slope
OBJECT/ATTRIBUTE: SITE/SLOPE

DEFINITION:   The surface properties of the soil in terms of gradient, complexity, configuration,
              length, and aspect; a property of the soil, not a landform.

VALUES:      STEEP
              MODERATE
              LEVEL TO NEARLY LEVEL

CATEGORY:   SITE BACKGROUND

PROPERTIES:  INPUT FACT

REFERENCES: Blakely,  et al., 1957
              Mason,  1983b, pp. 5-20
              USDA Soil Conservation Service, 1981  pp. 4-6 to 4-9; 4-95
VALUE:
Steep
DEFINITION:   A slope class of >12%; gradient, complexity, configuration, length, and aspect are
              high.

CONDITIONS:  Slope characteristics greatly affect the distribution, infiltration and subsequent
              percolation of soil water and surface runoff.  Slope gradient, the length and shape of
              slope along with slope aspect and the topographic position, e.g., mountain, lowlands
              or floodplain, are important site features to note.

CONDITIONS:  Steep slope characteristics greatly reduce the retention and infiltration of liquids.  Rate
              and amount of runoff is rapid; movement of  soil and other materials is high;  potential
              for soil slippage and acceleration of erosion  is high.  For every doubling of steepness
              of slope, loss of soil and other materials are  increased by 2.5 times.  Slope aspect is
              important; in the northern hemisphere north-facing slopes are cooler and exhibit lower
              evapotranspiration than south-facing slopes. Slope aspect is still important at high
              latitudes and in areas where winds are high, with corresponding evapotranspiration,
              and where there is  an increased rate and amount of solute removal, including soluble
              contaminants.
Guide to Site and Soil Description
                             3-24

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                                                                                     Site/Slope


VALUE:        Moderate

DEFINITION:    A slope of 3 to 12%.  Slope effects are not as high as for a steep slope.

CONDITIONS:  Length of slope and associated factors are still important.  The longer the slope, the
               more soil materials and liquids are lost.  If the length of slope is doubled, soil loss is
               generally increased 1.5x.  Effects of soil internal properties and surface characteristics
               increase relative to penetration rate or to runoff and deposition of sediment.
VALUE:
  Flat to nearly level
DEFINITION:    A slope of 0 to 3%.

CONDITIONS:  Slope effects are of decreased importance, with decrease in rates of runoff, erosion,
               and removal of sediment. However, the relatively flat areas receive sediments from the
               steeper slopes and can, therefore, accumulate transported metal contaminants.  Soil
               configuration and internal properties are more important with increased infiltration,
               penetration, and retention of water and chemicals.  Volumes of chemicals and rainfall
               are of increased importance for retention and movement of liquids.

         Table 3-4.  Definitions of Slope Classes,  (from the Soil Conservation Service,  1981)
            Classes

Simple Slopes       Complex Slopes
                                                           Slope gradient limits

                                                        Lower %           Upper %
Nearly level
Gently sloping
Strongly sloping
Moderately steep
Steep
Very steep
Nearly level
Undulating
Rolling
Hilly
Steep
Very steep
0
1-3
5-8
10-16
20-30
45-65
1-3
5-8
10-16
20-30
45-65
None
               Slope classes are largely determined from slope gradients.  A slope gradient is the
               inclination of the soil from the horizontal generally measured with a hand level.  The
               difference in the elevation between two points is then expressed as a percentage of
               the distance between those points.  If the difference in elevation is 1 m over a
               horizontal distance at 100 m, the slope is 1 %.
Guide to Site and Soil Description
                                 3-25

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                                                                         Site/Surface Erosion
OBJECT/ATTRIBUTE: SITE/SURFACE EROSION AND ERODIBILITY

DEFINITION:   Erosion:  wearing away of the soil or land surface by running water, wind, ice, or other
              geological agents, including such processes as gravitational creep. Erodibility:  the
              vulnerability or degree of susceptibility of soil to erosion processes.

 VALUES:      SEVERE
              MODERATE
              SLIGHT TO NONE

CATEGORY:   SITE BACKGROUND

PROPERTIES:  INPUT FACT

REFERENCES: Blakely, et al., 1957
              Chepil, 1957
              Mason, 1983b, pp. 5-26 to 5-28; 5-38 to 5-39
              USDA Soil Conservation Service, 1975
              USDA Soil Conservation Service, 1981, pp. 4-19 to 4-27
              Wischmeir and Smith, 1978
              Woodruff and Siddoway, 1965
VALUE:        Severe

DEFINITION:   Surface soil highly susceptible to erosion; surface soil and rock materials severely
              eroded, detached and transported through the action of water, wind, and other
              geologic agents. Estimated annual soil loss is 10 to  > 25 metric tons/hectare.

CONDITIONS:  Natural erosion is an important process that affects soil formation and/or the
              establishment of a vegetative cover. Man-induced influences may accelerate erosion,
              also by the two processes of classes of erosion, wind and water.  Wind erosion is
              important primarily, but not exclusively, in subhumid,  semiarid, and desert regions.
              Water erosion is important in humid regions, but is also important as an eroding agent
              in arid regions.  (Also see the knowledge frame on soil temperature regimes.)  In the
              field, surface erosion may be assessed as the amount of soil lost or deposited in the
              past at the site.  Erodibility  may be estimated as the future or potential for erosion.
              The Soil Conservation Service should be contacted for details on erosion and
              erodibility.

              Soil and surface materials are easily subject to removal by sufficient velocities of wind
              and water, or show signs of such removal, especially where soils are barren and
Guide to Site and Soil Description
3-26

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                                                                            Site/Surface Erosion
               fine-textured, either through natural processes (e.g., aridity), or disturbance.  The
               original surface soil has eroded away or can only be identified in spots.  Removal or
               depletion of vegetation and vegetative cover is the main cause of the wind erosion.
               Alternate wetting and drying, freezing and thawing tend to break down soil aggregates
               to granules that are highly erodible.  Poor management factors can promote erosion.
               Soil loss by  runoff per unit area generally increases substantially with length and
               steepness of slope.  Adequately designed waterways will greatly reduce runoff and
               erosion and may be the single most important control factor, other than vegetative
               cover.  In cultivated agricultural areas, soil management is an important factor,
               especially tillage operations, such as contour tillage, contour terraces, etc.

               The Universal Soil Loss Equation (USLE), or revised version (RUSLE) may be used to
               estimate potential erosion from a site, particularly as related to agriculture. The USLE
               considers both wind and water erosion. Field observations should include slope
               gradient and length (see knowledge frame for slope) and vegetative cover (or crop).
               Additional information, such as the erodibility factor, should be obtained from the SCS.
               The wind erosion equation also may be useful for predicting the average  annual loss
               of soil due to wind. These two equations are given below:

               Universal Soil Loss Equation (USLE) - An equation for predicting A,  the
               average annual soil loss in mass per unit area per year, and is defined
               as A = RKLSPC, where R is the rainfall factor, K is the soil erodibility
               factor, L is the length of slope, S is the percent slope, P is the
               conservation practice factor and C is the cropping and management
               factor.

               Wind Erosion Equation - An equation for predicting E, the average
               annual soil loss due to wind in mass per unit area per year,  and is
               defined as £ = IKCLV, where / is the soil erodibility factor, K is the soil
               ridge roughness factor, C is the local climatic factor, L is the field
               width, and V is the vegetative factor.

               Chemicals that destroy vegetation will promote erosion as well as runoff.  Severe
               erosive forces increase the potential for removal and dispersion of applied
               contaminants and limit their potential for subsurface penetration and accumulation.
VALUE:        Moderate

DEFINITION:    Surface soil is moderately susceptible to erosion; surface soil and rock materials show
               some evidence of erosion. Estimated annual soil loss is 2.5 to 10 t/ha.
Guide to Site and Soil Description
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                                                                            Site/Surface Erosion
CONDITIONS:  Soil and surface materials are less subject to removal except by high and
               long-duration velocities of wind or water. Surface effects of erosive forces are evident,
               but reduced through moderating properties of soil, topography, and vegetation. The
               natural surface soil may still have lost a considerable amount of material of the surface
               horizon or top 10 to 12 inches (-20 to 25 cm).  Applied chemicals, depending on their
               nature (e.g., viscosity), may promote some soil properties to reduce erosion/erodibility
               (e.g., promotion of aggregation and adhesion), or increase potential for
               erosion/erodibility, damage or destruction of vegetative cover.
VALUE:        Slight to None

DEFINITION:    Surface soil is only slightly or undiscernibly susceptible to erosion, temporally or
               spatially; surface soil and other surface materials show little evidence of erosion.
               Annual soil loss is <  2.5 t/ha to zero.

CONDITIONS:  Soil surface materials are little affected or are otherwise protected from erosive forces
               of either wind, water or other geologic forces.  Climate/weather (humid/moderate), soil
               properties, and surface features, topography and vegetation (nature, extent and
               depth)  are favorable factors to reduce or ameliorate erosion/erodibility.  Applied
               chemicals will have reduced potential for soil and chemical removal  and transport by
               erosive forces of wind and water. Potential for penetration and subsurface infiltration,
               movement, and accumulation is increased.
Guide to Site and Soil Description
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                                                                       Site/Surface Pollution
OBJECT/ATTRIBUTE:  SITE/SURFACE POLLUTION SITUATIONS

DEFINITION:   Contamination of the soil with various harmful compounds and materials primarily
              introduced by human activities.

VALUES:      LARGE AREAS
              LOCALIZED AREAS

CATEGORY:   SITE BACKGROUND

PROPERTIES:  INPUT FACT

REFERENCES: DeHaan and Bolt, 1979
              Mason, 1983, Appendix 3, pp. 9-12
              Sims, 1986
VALUE:
Large Areas
DEFINITION:   The pollutant covers a wide area, primarily on the surface.

CONDITIONS:  The pollutant usually covers an area large enough to encompass a variety of parent
              materials, a number of soil "types" (map units) with varying soil properties, various
              topographic features, slopes, aspects, and kinds and distribution of vegetation. The
              major pollutant source may have been present for a short time, with appropriate
              survey studies made by ambient monitoring.  The effects and extent of pollution may
              be ameliorated over a longer period. Pollutants may have  migrated into the soil as
              much as 1 to 2 feet (30.5 cm - 61 cm).  Where significant organic matter is present,
              penetration may be lessened to only a few inches or cm, but chelation with organic
              matter (humus) may mobilize metal  ions and  they may be attenuated with depth in the
              soil solution. Movement of heavy metals through soils is largely  dependent on the
              organic matter content of the soil. The greater the organic matter content of the
              upper horizon of soil, the greater the affinity of that horizon for heavy metals. Stratified
              sampling may be desirable, with a large number of samples taken. Hand tools can
              usually be used to collect samples.
Guide to Site and Soil Description
                             3-29

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                                                                          Site/Surface Pollution
VALUE:
Localized Areas
DEFINITION:    Areas usually polluted near the source.

CONDITIONS:  These areas are usually affected by spills resulting from industrial or transportation
               accidents, fires, explosions, or unexpected leaks from storage containers. Polluted
               areas cover less area, with only a few differences in parent material,  soil "types" and
               properties, surface features,  and vegetative features.  The polluted area may be more
               readily identified from the unaffected area because of noticeable differences in color,
               odor, and effects on other soil properties and site vegetation.  Sampling may be more
               rapidly performed than for large affected areas.  Grid, simple random sampling, and,
               in some specialized cases, stratified sampling may be performed.  Samples usually
               are collected with a core sampler and can be composited in some cases, unless
               organic contaminants (volatiles and semivolatiles) also must be considered for
               analytical purposes.
Guide to Site and Soil Description
                              3-30

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                                                                         Site/Surface Runoff
OBJECT/ATTRIBUTE:  SITE/SURFACE RUNOFF

DEFINITION:   That portion of the meteoric precipitation on an area of soil or land surface discharged
              from the area through natural or manmade stream channels.
VALUES:
RAPID
MEDIUM
SLOW
PONDED
CATEGORY:   SITE BACKGROUND

PROPERTIES:  INPUT FACT

REFERENCES: Mason, 1983a
              USDA Soil Conservation Service, 1981, pp. 4-34 to 4-35, 5-15 to 5-20; 5-41 to
              5-42; A5-55 to A5-79
VALUE:        Rapid

DEFINITION:   Surface water or liquid chemicals flow so fast that the period of concentration is brief
              and free water or chemicals do not stand on the surface.

CONDITIONS:  The soils are frequently moderately steep to steep (about 10% slope or greater) and
              rates of penetration and infiltration are slow. Slope shape, whether convex, concave
              or complex and topographic position are important.  Other soil surface properties,
              such as crusts, compaction and cementation, high clay content and hydrophobic salts
              will increase runoff and transport of sediments and applied contaminants, including
              metal species.  High viscosity of the liquid chemicals will provide for increased flow
              rate and runoff.  Also see knowledge frame on infiltration and percolation.
VALUE:
Medium
DEFINITION:   Surface water or liquid chemicals flow away fast enough so that free liquids stand on
              the surface for only short periods.

CONDITIONS:  The surface soils are less steep, and nearly level or gently sloping (0 - -10% slope)
              and absorb liquids at a moderate rate, or they are steeper but absorb liquids rapidly.
              Part of the liquids, depending on viscosity, will enter the soil, but they also are subject
Guide to Site and Soil Description
                             3-31

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                                                                            Site/Surface Runoff
               to evaporation or movement along subsurface channels. Migration of medium-velocity
               chemicals on the surface will be moderate.  High intensity of rainfall or application of
               hydrophobic liquid chemicals will increase runoff, as will frozen, compacted, or
               cemented soil, and other soils with lesser degree of infiltrability.
VALUE:        Slow

DEFINITION:    Surface water or liquid chemicals flow away slowly, and may stand freely on the
               surface for moderate to long periods.

CONDITIONS:  Liquids immediately or rapidly enter the soil, pass through it, or evaporate.  Soils are
               very gently sloping (<  5%), nearly level or level (0 - 3% slope), very open and porous,
               and do not impede infiltration and penetration of liquids.  Surface conditions provide
               greater potential for retention of contaminants.
VALUE:
Ponded
DEFINITION:    Little of the rainfall,  runon, or liquid chemicals escape as runoff, and they freely stand
               on the surface for significant periods.

CONDITIONS:  The quantity of liquids removed from ponded areas is by evaporation, by gradual
               movement through  the soil,  or possibly by plants unless physically removed by
               mechanical means  (e.g., siphoning).  Evaporation is usually greater than the total
               rainfall, but may not exceed that of applied chemicals, especially of low viscosity.
               Ponding normally occurs on level to nearly level depressional soils.  Tight, clayey,
               nonporous soils, compactions and pans in depressed soil will increase ponding until
               depressions are filled. Depth of liquids may fluctuate greatly, with considerable
               potential for infiltration and accumulation at subsurface depths.
Guide to Site and Soil Description
                              3-32

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                                                                              Site/Vegetation
OBJECT/ATTRIBUTE: SITE/VEGETATION

DEFINITION:   The nature, kind, extent and distribution of plants and plant cover for a given,
              designated site.

VALUES:      DENSE
              SCATTERED TO SPARSE
              ABSENT

CATEGORY:   SITE BACKGROUND

PROPERTIES:  INPUT FACT

REFERENCES: Cruickshank, 1972, pp. 101-154
              Ricklefs, 1979, pp. 27-202
              Shaw, 1989
              USDA Soil Conservation Service, 1981, pp. 4-10 to 4-12
              US DOE, 1987, pp. E-179 to E-184
              Vogel, 1987
VALUE:       Dense

DEFINITION:   Site completely covered with vegetation of predominant forms or varying in
              composition and distribution of species, usually with slow temporal variability.

CONDITIONS:  Inputs to an ecosystem or site from existing vegetation occur in a number of ways;
              inputs from above-ground biomass, inputs from roots and other below-ground
              biomass, and leaching and washoff from leaf surfaces.  These inputs are also
              considered fluxes within the ecosystem. The lead concentration of most vegetation is
              relatively low despite evidence that it is probably as much as five times higher than
              prior to industrialization.  In forested sites under a variety of conditions in Europe and
              North America, the amounts of lead, cadmium, and nickel in vegetation are somewhat
              lower than the amounts of the same metals in soil. Near smelters, vegetation levels of
              most metals are quite high.

              Generalizations about the behavior of heavy metals in relation to vegetation is difficult.
              Metals that are clearly harmful to vegetation are generally excluded from uptake by
              roots or through foliage.  However, other heavy metals that may  be considered
              essential to plants are micronutrients (e.g., copper, zinc) which may behave more like
              macronutrient elements with respect to their cycling rates and accumulation patterns.
              Vegetation is usually the  first interceptor of heavy metals deposited to an ecosystem.
Guide to Site and Soil Description
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                                                                                Site/Vegetation
              However, if the ecosystem is sparsely vegetated, soils may be the first interceptor of
              heavy metal deposition. Heavy metals in water contacting vegetation may be (1)
              adsorbed to vegetative surfaces; (2) absorbed into the cuticle or leaf; or (3) relatively
              unaffected by vegetation.  If metals are adsorbed onto leaf and other vegetative
              surfaces, they may be remobilized later by water. Depending on the element leaching
              from foliage, and washoff of dry deposited material, there may be an influence on the
              net change in heavy metal flux above and  below a vegetative cover or canopy.

              Some heavy metals,  such as iron, manganese, zinc, copper and molybdenum are
              essential micronutrients.  Others, such as arsenic, aluminum, cadmium, chromium,
              mercury and lead are not essential.  Regardless of whether they are biologically
              essential or not, a common characteristic of heavy metals in general, is that they may
              already exert toxic effects in low concentrations, compared with macronutrients.  Many
              plant essential micronutrients which are heavy metals, i.e., copper, iron, manganese,
              and zinc, can be toxic to plants encountered in natural, uncontaminated ecosystems.
              Local enrichment of heavy metals in soils,  either through natural processes
              (geochemical anomalies) or human activities (exploitation of mineral resources),
              usually coincides with increased resistance levels in plants.  Metal resistance is
              typically a quantitative characteristic, correlated with the prevailing metal availability
              levels in the soil.  Metal resistance is usually  highly  metal specific and confined to
              those metals often associated with co-occurrence of high levels of these metals in the
              soil. However, some resistant plants may  also show a degree of resistance to metals
              only present at low nontoxic levels.  Many  resistant plants exhibit an increased need
              for certain metals to  which they are resistant, as expressed by a less than maximal
              growth at "normal" availability levels.

              Vegetation cover may show predominant species of trees and canopy, shrubs,
              grasses, and forbs (weeds). Soil vegetation  cover may include algae, mosses,
              lichens, and liverworts. Potential for runoff and erosion is greatly retarded, especially
              with extensive soil vegetative cover. The efficiency  (effects) of plants and their effects
              by site pollutants should be noted, such as damaged plant parts, and effects on
              growth, reproduction, and distribution.  Plant species distribution, location, and
              proximity to a pollutant source,  and the condition of plant parts should be noted and
              recorded. Some plants may not show visible effects and appear to be "healthy,"
              although pollutant uptake may have occurred.  Compare with analyses of various soil
              metal contaminants and adjacent or off-site vegetation.  It may be desirable to collect
              plant parts and soils for further studies including plant tests for foliar analyses.
              Photographs should be taken to show aerial and soil surface plant cover distribution
              and any unusual plant features. Plant cover should be cleared or removed from
              sampling sites to expose surface soil. Plant parts may be retained for further
              analyses.
Guide to Site and Soil Description              3.34

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                                                                              Site/Wind Speed
VALUE:
Breezy
DEFINITION:    Wind speeds 4 to 32 MPH (~3 to 37 knots); wind direction varies, but usually less than
               180°.
CONDITIONS:  At lower velocities, wind is evident, being felt on the face; leaves rustle and grasses
               move; a flag or cloth moves out a little from a staff. At higher velocities,  large
               branches are in motion; whistling may be heard in any nearby wires; a flag or cloth
               stands straight from a staff and flutters vigorously.  Wind directions may be constant,
               or more, up to 180°. Sampling is preferable at lower velocities.  The support area
               should be upwind of the exclusion area. Ideally, wind should blow away from both the
               hazardous substance site and support area. A 40° arc of wind or less variation is the
               ideal, but 180°  can be tolerated. A windshield should be in place.  Changes in wind
               speed or direction should be noted during sampling.  Higher wind speeds and
               variance in direction > 180° arc, may necessitate postponement of sampling.  Check
               with local weather bureau for forecasts.
VALUE:        Calm to Light

DEFINITION:    Wind speed  < 4 mph (< 3 knots)

CONDITIONS:  Smoke will rise vertically or drift with wind direction; flag or cloth on staff will lie limp or
               barely move.  Variance in arc direction is relatively insignificant. The sampling
               condition is ideal.  The wind shield is usually not necessary, unless winds become
               gusty and changing.
Guide to Site and Soil Description
                              3-37

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                                        SECTION 4.0

                                 SOIL KNOWLEDGE FRAMES

This section contains soil knowledge frames that can be used in the field to identify and describe
soils.  The knowledge frames are presented in ESES documentation an derivatives such as this guide.
The format of the knowledge frames is explained in Section 3.

This section presents soil knowledge frames for the following attributes:

       Bulk Density
       Cation Exchange Capacity (CEC)
       Clay Minerals
       Color
       Compaction
       Consistency
       Corrosivity (Corrosion Potential)
       Electrical Conductivity
       Fertility Potential
       Horizons
       Hydraulic Conductivity
       Infiltration and Percolation
       Mesofauna and Macrofauna
       Microbiota
       Moisture (Water) Conditions
       Odor
       Organic Matter and Litter
       Porosity
       Reaction (Ph)
       Redox Potential (Eh)
       Roots
       Structure Grades
       Surface Features
       Temperature
       Temperature Regimes
       Texture Classes
Guide to Site and Soil Description               4.-)

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                                                                             Soil/Bulk Density
OBJECT/ATTRIBUTE:  SOIL/BULK DENSITY
DEFINITION:



VALUES:



CATEGORY:

PROPERTIES:

REFERENCES:
The ratio of the mass of dry solids to the bulk volume of the soil (including air
space) B.D. = g of soil dried (usually for 24 hr.) to 105 °C/cc of soil volume
obtained in the field.

LOW
MEDIUM
HIGH

SITE BACKGROUND

INPUT FACT

American Society for Testing and Materials, 1984, Vol. 11.01
Blake and Hartge, 1986, pp. 363-375
Lewis, 1979, pp. 47-48
Mason,  1983a
Richards, 1954
US EPA, 1991 a, Part II, Section 6, p. 12
VALUE:            Low

DEFINITION:        The bulk density is usually between 1.0-1.3 g/cc of soil.

CONDITIONS:       Bulk density is concerned with the soil solid particles and pore space.  It is not
                   an invariant quantity for a particular soil. Mineral soils usually have a bulk density
                   greater than water 1  g/cc; organic soils may vary in bulk density from ~0.3-<1.0
                   g/cc of soil. Clay soils have the lowest bulk density except for some volcanic
                   soils and highest related porosity. Soil bulk densities usually increase with depth
                   due to less organic matter,  less aggregation, and compression from the weight of
                   the overlying soil.  Lower bulk densities in association with good structure
                   promote good aeration and drainage.  Finer textured soils with higher organic
                   matter than other mineral soils and more favorable structure have more pore
                   space and lower bulk densities. Top soils in many areas have a value of 1.1-1.3
                   g/cc.  Highly organic soils also will have a low bulk density both because the
                   density of the solid material is low and there is a large amount of pore space.
                   Bulk density will vary by soil horizons and layers and are considerably  affected
                   not only by texture and organic matter content, but also by its structure,
                   compaction, puddling, swelling, and shrinking characteristics, which are
                   dependent upon clay content and wetness.  Soil metal adsorption and retention
Guide to Site and Soil Description
                          4-2

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                                                                              Soil/Bulk Density
                   can be greater in soils of lower bulk density.  See related soil factors including
                   knowledge frames on compaction, clay minerals, structure grades, texture
                   classes and organic matter.  Soil samples are procured in the field by the core or
                   clod method. The core method is unsatisfactory for very hard, stony,  or easily
                   compacted soils.  Radiation methods, using gamma transmission or scattering,
                   may be used in the field to estimate bulk density, but it measures all combined
                   components. See Boulding (1991) A Field Pocket Guide, for details.
VALUE:            Medium

DEFINITION:        Soils generally with bulk densities between 1.3-1.6 g/cc of soil.

CONDITIONS:      The bulk density values indicate soils of medium texture, usually clay loams, silt
                   loams and loams, and significantly less organic matter than highly organic soils.
                   For subsoils, bulk density values are usually greater than for those of topsoils
                   and can range from 1.3-1.7 g/cc, but soil manipulation and other factors can also
                   affect these values.  Management or other practices that increase bulk density
                   will also decrease the percent of pore space, restrict gas diffusion, reduce water
                   movement and leaching. In general, metal retention and movement is affected as
                   bulk density increases, when the texture becomes more coarse (sandy or loose),
                   or the soil more compacted.  These two factors work against each other and are
                   complicated by other soil factors.
VALUE:            High

DEFINITIONS:       Soils generally with bulk densities between 1.6-1.8 g/cc of soil.

CONDITIONS:       The bulk density values indicate sands or sandy soils, or highly compacted soils
                   with reduced pore space. Loose and coarse textured soils, such as gravelly
                   loams may even exceed a bulk density value of 1.8 g/cc of soil as for medium
                   bulk density values, any management practices that increases bulk  density is
                   usually unfavorable because it decreases pore space, restricts gas diffusion, and
                   restricts water movement, especially for plant growth. A high bulk density
                   indicated by coarse texture and loose materials favors movement and activity of
                   metal ions; a high bulk density  resulting from soil conditions such as compaction,
                   reduces their activity, movement, and leachability.  However, even in highly
                   compacted soils, the  bulk density may remain appreciably lower than the particle
                   density, and the soil generally never becomes completely impervious.
Guide to Site and Soil Description
4-3

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                                                              Soil/Cation Exchange Capacity
OBJECT/ATTRIBUTE:  SOIL/CATION EXCHANGE CAPACITY (CEC)
DEFINITION:



VALUES:



CATEGORY:

PROPERTIES:

REFERENCES:
The sum total of exchangeable cations that a soil can adsorb, expressed in
milliequivalents per 100 grams or per gram of soil. Usually determined by
ammonium acetate at pH 7.

LOW
MEDIUM
HIGH

SITE BACKGROUND

INPUT FACT

American Society for Testing and Materials, 1984, Vol. 11.01
Bache, 1979, pp.38-41
Mason, 1983a
Peck and Melsted, 1973
Richards, 1954
Rhoades, 1982a, pp. 149-157
Talibudeen, 1981
USDA Soil Conservation Service, 1984
USDA Soil Conservation Service, 1970
US EPA, 1991 a, Part II,  Sec. 7, 27 pp.
VALUE:            Low

DEFINITION:       The CEC is < 12 meq/100 g soil.

CONDITIONS:      CEC measures the ability of a soil to absorb (and release) cations, predominantly
                  metals, but also ammonium, in exchangeable forms. It corresponds to the
                  negative charge of soil. The predominant, naturally occurring exchangeable
                  cations in soil are calcium, magnesium, potassium, sodium, aluminum, hydrogen,
                  iron and manganese.  In acid soils, calcium, magnesium, and aluminum
                  predominate.  In calcareous soils, calcium and magnesium occur at most of the
                  exchange sites.  The sodium ion predominates in salt-affected soils.  All of the
                  heavy metals in soil solution are primarily cationic except for molybdenum, which
                  occurs as molybdate ion. The CEC generally increases as the pH rises, and with
                  the increase in exchangeable sites provided by clays and organic matter content.
                  Some kaolin mineral soils will have CEC of 1-8 meq./100 g of soil. The effective
                  CEC of organic matter contributes approximately 2 meq./100 g of soil toward the
Guide to Site and Soil Description
                         4-4

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                                                                 Soil/Cation Exchange Capacity
                   soil CEC.  One percent clay provides approximately 0.5 meq./100 g soil. A low
                   CEC is found in soils low in organic matter and clays as in sands and sandy
                   loams, with approximately 2-12 meq./100 g soil.  Mineralogical clay soils do not
                   effectively vary in CEC when the pH is <5. Base-saturated soils, e.g., calcium,
                   magnesium, potassium, sodium, and ammonium, are neutral in reaction, whereas
                   nonbase saturated soils are acid.  Iron, aluminum and titanium oxides, as well as
                   noncrystalline iron and aluminum silicates and phosphates may add to the CEC
                   of some soils.  Addition of some chemicals, including those containing heavy
                   metals, may additionally add to the soil CEC. With low CEC values,  metal
                   adsorption also is expected to be correspondingly low. Metal ions in soil water
                   may be removed by adsorption and/or precipitation.  Factors affecting the
                   interrelationship between  adsorption and precipitation are the concentration of
                   the cations in the soil water, the cation-anion pairing, the complexation or
                   chelation by organic molecules and soil pH. Changes in the soil solution and
                   temperature will both cause a redistribution of ions between solution and
                   exchange sites on clay minerals and oxides.  CEC is not a soil property that is
                   independent of the conditions under which it is measured, and it is seldom
                   practical to determine the CEC of each soil sample relevant to its specific field
                   condition. Different methods are to be used for arid land (and salty soils) or for
                   acid soils. All values require procurement of a soil sample and subsequent
                   analysis in the laboratory. Also see knowledge frame on Nature of Heavy Metal
                   Soil Pollution, sections on CEC.
VALUE:            Medium

DEFINITION:        The CEC is between 12-20 meq./100 g soil.

CONDITIONS:      Soils that are loams or silt loams have representative CEC of approximately 12-20
                   meq.  Naturally occurring cations (bases) along with certain contaminant metals
                   will be retained by these soils, especially by clays, against rapid loss by leaching,
                   but they may still be available for absorption by plants. Soils with more organic
                   matter, along with a higher pH, also will tend to have a higher CEC than soils
                   with less organic matter.  Retention of cations, including mobile heavy metals, is
                   higher for soils containing more clays, organic matter, and pH values above
                   neutral.
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                                                                 Soil/Cation Exchange Capacity
VALUE:            High

DEFINITION:        The CEC is 20-40 meq. or more per 100 g soil.

CONDITIONS:      The CEC is high in clay soils or those high in organic matter.  Montmorillonitic
                   clay soils will have higher CEC than kaolinic clay soils, up to 80-150 meq/100 g
                   of soil. The  CEC of illite is 10 to 40 meq/100 g of soil; kalonite, 3 to 15 meq/100
                   g of soil and oxides and hydroxides, 2 to 6 meq/100 g of soil. Organic matter
                   has a CEC of 200 to 400 meq/100 g of soil.  Cation selectivity in organic matter
                   depends mainly  on the disposition of the acidic groups.  Cation selectively also
                   increases with CEC. There is a diminished contribution of organic matter to CEC
                   at pH values < 6.0.  Depending upon the nature of the adsorbed cation  or metal,
                   the amount and  nature of the adsorbent, and leachability, these soils will have a
                   high ability to retain and/or release cations.  If contaminated with applied
                   chemicals, special attention should be given to these soils for adsorbed  cations
                   and their activity, either for their retention or susceptibility to be found in  runoff or
                   leachate.
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                                                                            Soil/Clay Minerals
OBJECT/ATTRIBUTE:  SOIL/CLAY MINERALS
DEFINITION:



VALUES:



CATEGORY:

PROPERTIES:

REFERENCES:
Naturally occurring, inorganic, crystalline phyllosilicate (sheet layer silicate
mineral) materials found jn soils and other earthy deposits; not limited to particle
size of 0.002 mm diameter or less.

ABUNDANT
MODERATE TO SLIGHT
NONE TO NEGLIGIBLE

SITE BACKGROUND

INPUT FACT

Birkeland, 1984
Cady, Wildung and Drees, 1986
Dinauer, 1977
Dixon and Weed, 1977
Grim, 1953
Kittrick, 1986
Mason, 1983, pp. 5-14
USDA Soil Conservation Service, 1970, pp. 39-42
Stotzky, 1986
VALUE:            Abundant, > 27%

DEFINITION:        Clay minerals are evident as a major constituent of the soil. Silicate clays are
                   common in temperate zones; iron and aluminum hydrous (oxides and
                   oxyhydroxides) clays are found in the tropics. Kaolinite (nonexpanding lattice
                   structure) clays predominate in moist, warm climates; montmorillonite (expanding
                   lattice structure) clays predominate in arid areas.

CONDITIONS:      Clay minerals develop and are formed in soils through the weathering  of parent
                   rocks under conditions similar to those for soil forming factors: time, climate,
                   topography, and effects of biota (vegetation).  The same "type" of soil with a
                   characteristic clay mineral composition can develop from rocks of widely different
                   composition and texture after a relatively long period of time.  Clay  minerals
                   exhibit physicochemical properties similar to those of plate- or sheet-like
                   structure. Minerals with sheet-like structures can be categorized as kaolinites,
                   illites, and montmorillonites. Because  of their surface change nature, they have
                   the ability to weakly adsorb cations from the soil solution.  The weak chemical
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                          4-7

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                                                                              Soil/Clay Minerals
                   bond has an important role in the overall chemical reaction of cations, organic
                   content and hydrous oxides present in the soil.

                   An examination of soil properties in the field or laboratory reveals the effects and
                   abundance of clay minerals. This examination of related soil properties should
                   include texture, structure, porosity, infiltration, percolation, color, moisture-holding
                   capacity and retention, consistency, compaction, and other properties.  A
                   nongritty soil with aggregates that, when wet, easily break down, and that is
                   highly plastic reveals significant presence of clays.  When dry, clay soils are
                   extremely difficult to disaggregate. Clays are major constituents that influence
                   the retention of water and chemicals and, under some circumstances, can
                   control the rate of chemical (and ionic) migration through the soil. The more
                   reactive the chemical, the greater its potential for being bound to the soil or
                   changed by surface reaction with clay minerals.  Laboratory clay mineralogical
                   examinations should be performed, if necessary.  A clay soil will have as much as
                   or more than 10 times the exchange capacity that a sand does.  Swelling and
                   shrinking of clay soils may create macropores favoring preferential flow of water
                   and liquid chemicals.  This  may limit the penetration of mobilized metals into soil
                   peds.  A compacted day soil has increased bulk density and reduced pore
                   space, and has the capacity to hold liquids and sorb metals.  A saturated
                   solution of malachite green in nitrobenzene may be used to detect
                   montmorillonite and illite. A yellow-red color  of wetted soil indicates
                   montmorillonite;  a purple-red color indicates illite.

                   Clay organic matter reactions and transformations are important. Bioactivity of
                   pesticides, for example is related to the organic matter and to the clay minerals
                   present.  Cationic pesticides lose their bioactivity on contact with soil clay
                   particles, become virtually immobilized, and resist biodegradation.  Average CEC
                   for clays is:  montmorillonite, 100  meq/100 g of soil; illite, 30 meq/100 g of soil;
                   and kaolinite, 8 meq/100 g  of soil. The type  and concentration of clay minerals
                   affects the toxicity of heavy metals on  microorganisms.  The effect of clay
                   minerals on the toxicity of heavy metals is usually an alternating effect and
                   appears to be primarily a function of the CEC on clays.  Cationic species  of
                   heavy metals have the ability to exchange for noncationic forms and thereby
                   reduce the concentration of toxic  metals in the soil solution.

                   Metal species may be tightly bound and difficult to dislodge from clayey soils,
                   and their retention time is considerably longer than for nonclayey soils.
                   Adsorption of heavy metals on clays can be  considerably influenced by pH.  For
                   example, adsorption of cadmium, copper, lead and zinc to kaolinite, illite and
                   montmorillomite increases as the  pH increase, but if the pH is favorable for the
                   formation of hydroxylated metal species, then the metal precipitates rather than
                   be adsorbed. The background concentration of competing cations also affects
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                                                                              Soil/Clay Minerals
                   the adsorption of heavy metals to clay minerals as do also inorganic and organic
                   ligands.  When organic matter blocks the exchange sites on minerals, the
                   selectivity for alkali metals, e.g., potassium, is considerably reduced. Formation
                   of clay-organic-metal complexes reduces their susceptibility to microbial
                   degradation, which can be important for bioremediation of some waste sites.

                   Presence of a large quantity of clay minerals may affect soil sampling procedures
                   because of physical effects on soil properties and resultant  difficulties in sampling
                   when tightness or hardness makes the soil difficult to penetrate or dislodge.  Also
                   see knowledge frame on texture classes: clays.
VALUE:            Moderate to Slight, 1 to 27%

DEFINITION:        Clay minerals are evident, but nonclays, including organics, also are significant
                   soil constituents.  A visual examination of soil particles may reveal a consideiable
                   percentage of visible single grains (>  50%).

CONDITIONS:      A small percentage of clay, even as low as 1 to 5%, will still have an  influence on
                   retention and exchange of water, other liquids, sorbed nutrients, and other soil
                   properties. Contaminants, in general,  are more free to move within the soil body
                   than they are in a soil with higher clay content.
VALUE:            None to Negligible, < 1%

DEFINITION:        Undetectable visual presence of clays and absence of effects of clays on other
                   soil properties, as indicated under abundant value. Sands, silts, or organic
                   matter are the predominant soil solids.

CONDITIONS:      Retention and exchange of water, nutrients, and chemicals, including metal
                   species, are relatively insignificant. However, in natural soils  important nonclay
                   minerals may be present including carbonates, calcium-magnesium carbonate
                   (dolomite), soluble salts of potassium and sodium (as chlorides, nitrates, and
                   sulfates), partially soluble calcium sulfate (gypsum), and iron  and manganese
                   oxides, which  have a high sorption capacity for heavy metals. Trivalent oxides of
                   iron have  extremely low solubilities in the normal pH range of soils.  The
                   geochemical nature and generally high specific surface area  of iron oxides in soil
                   particles and as coatings on other particles make them efficient sinks for anions
                   such as phosphate, molybdate, and silicate as well as for heavy metals such as
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                                                                             Soil/Clay Minerals
                   copper, lead, zinc, cobalt, chromium, and vanadium.  Iron oxides also affect soil
                   structure and matrix, often being responsible for the formation of aggregates and
                   cementation of other major soil components.  Manganese oxides also occur in
                   soils as coatings on other soil particles, deposited in cracks and veins and as
                   nodules.  Manganese oxides also have high specific surface areas, carry a high
                   negative charge in all but extremely acid soils, and have high adsorption
                   capacities which can result in the accumulation of relatively high concentrations
                   of heavy metals in soils.  Manganese oxides are noted for their adsorption of lead
                   and cobalt.  Also see knowledge frame on soil texture: skeletal.
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                                                                                  Soil/Color
OBJECT/ATTRIBUTE:  SOIL/COLOR
DEFINITION:
VALUES:
CATEGORY:

PROPERTIES:

REFERENCES:
The phenomenon of light or visual perception of the soil's physical appearance in
terms of hue, lightness, and saturation, measurement is by reference to standard
color charts (e.g., Munsell color system for hue, value, and chroma) to make up a
specific color notation.

DARK
RED AND YELLOW
BROWN
GRAY/WHITISH
MOTTLED

SITE BACKGROUND

INPUT FACT

Munsell Color Company, 1954
Olson, 1981, pp. 17-22
USDA Soil Conservation Service, 1981, pp. 4-60 to 4-70
USDA Soil Conservation Service, 1975, pp. 463-368
USDA Soil Conservation Service, 1970, pp. 15-18
VALUE:             Dark

DEFINITION:        A soil color usually related to significant organic matter content, unless dark-
                   colored minerals are present.

CONDITIONS:       Color and color patterns in soil are good indicators of drainage characteristics of
                   soils, which is important contaminated sites. In general, dark or blackish soils,
                   because of organic matter content are most productive and have good structure
                   and other related favorable soil properties, but black soils can also be the result
                   of minerals and poor drainage.  Dark-colored soils low in organic matter may
                   contain compounds of iron and humus, elemental carbon, compounds of
                   manganese, magnetite and dark-colored clays.  In well-drained soils, the color
                   generally increases from light brown to black with increased organic matter.
                   Also, note temperature effects on soil organic matter and color, and association
                   of organic matter with colloids, compounds of iron and humus, manganese, and
                   elemental carbon compounds. Highly organic soils will sorb higher
                   concentrations of metal species and form metal-organic complexes which  may
                   increase mobility of metals under anaerobic conditions. See knowledge frame for
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                                                                                     Soil/Color
                   Soil Organic Matter.  Use Munsell Soil Color charts for soil color designations of
                   hue, value, and chroma (e.g., 2.5Y 2/0, a black soil).
VALUE:            Brown

DEFINITION:        Brown soils contain significant amounts of iron oxide, organic matter, or both.

CONDITIONS:       These soils vary between dark and reddish to yellowish, with intermediate
                   properties of both resulting from effects of soil-forming factors and development.
                   Unless applied chemicals are highly colored, brown soils will be more affected in
                   color by minerals, organic matter, and moisture content.  A uniform brown color
                   tends to indicate a soil that is well drained and not usually saturated with water.
                   Metal species  may be sorbed and complexed with organic matter or may interact
                   with soil iron.  Example of Munsell soil notation is 10 YR 5/3, brown.
VALUE:            Red and Yellow

DEFINITION:        A red soil color is usually related to unhydrated iron (Fe2O3); yellow, to hydrated
                   iron (Fe2O3 • H2O).

CONDITIONS:      Uniform red and yellow soils are usually indications of good drainage and
                   aeration (favorable porosity)  and are seldom or never saturated with water.  In
                   general, they are considered less productive and are less fertile than black or
                   dark brown soils. Iron oxides have a high pigmenting power and largely  affect
                   the soil color.  The color of many reddish soils and yellowish-brown soils  is due
                   to iron oxides. Strongly red  soils are expected to be highly permeable. Soil
                   materials may be old, or have been subjected to a longer period of intense
                   weathering. Red and yellow soils increase toward the equator. In deeper soils, a
                   yellow color indicates a more humid effect on soil formation. Yellow soils may be
                   due to hydrated iron oxides. Many yellow soils are imperfectly drained or from a
                   previous condition of restricted drainage.  Yellow soils have low inherent
                   productivity.  Red and yellow soils may indicate potential for more rapid
                   movement of liquids than for dark-colored,  organic soils,  but drainage also may
                   be impaired. Less metal species may be sorbed than in highly organic soils.
                   Example of Munsell soil  notation is 5R 5/6,  red; 5Y 8/8, yellow.
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                                                                                     Soil/Color


VALUE:            Gray/Whitish

DEFINITION:        Grayish or whitish soils are the result of several substances, mineral or organic.

CONDITIONS:      Whitish soils are indications of minerals such as quartz, kaolin, pumicite,
                   diatomaceous earth, carbonate, or gypsum. Gray (or blue) colored soils indicate
                   that the soil is saturated continuously or for extended periods and would retain
                   contaminated solutes.  Grayish colors (chroma <1) occur in permanently wet
                   soils,  in the  presence of organic matter, may have low organic matter content or
                   low iron, or with significant ferrous iron. Intense reduction (gleying) involves
                   saturation of soil with water for long  periods in the presence of organic matter.
                   Gleyed soils change to brown upon  exposure to air, with accompanying change
                   in oxidation-reduction (Eh) status. Reduced forms of  metals may be found in
                   gleyed soils. Metals may become mobilized under anaerobic conditions.  Unless
                   applied pollutants are distinctly nongreyish or  white, they may be obscured by
                   the inherent soil colors.  An example of Munsell soil notation is 2.5 Y 7/2, light
                   gray.
VALUE:            Mottled

DEFINITION:        A soil showing spots of different colors in a relatively uniform soil matrix.

CONDITIONS:      Colors of mottled soils are described by  noting both the color of the predominant
                   soil matrix and of the mottles. The dominant color (or colors) are given first, and
                   then described as details of the color pattern. Description of mottles requires
                   three sets of notation: contrast, abundance,  and size.  See the following table
                   (Table 4-1) for describing contrast, abundance, and size, and Boulding, (1991), A
                   Field Pocket Guide, for designation of mottle  contrasts to be used with the
                   Munsell Soil Color Chart.
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                                                                                    Soil/Color
          TABLE 4-1. Terms for Describing Soil Mottles (Adapted from USDA SCS, 1981).

   Distinctiveness   Contrast

   Faint             Indistinct mottles. Closely related hues and chromas of matrix mottles.

   Distinct          Mottles easily seen.  Mottles vary from matrix as much as 1 or 2 hues or
                    several units in chroma or value.

   Prominent        Conspicuous mottles.  Hue, value, and chroma may be several units apart.

                    Abundance

   Few             < 2% of exposed surface

   Common         2-20% of the exposed surface

   Many            > 20% of the exposed surface

                    Size

   Fine             < 5 mm in diameter

   Medium          5-15 mm in diameter

   Coarse          > 15  mm in diameter

                   Mottles have many different shapes in the soil matrix and these shapes should
                   be noted if significant. Many mottles are roughly circular,  but others are
                   elongated or show merging streaks, tubes, bands, or spots. Soil mottles are
                   affected not only by their chemical composition  and oxidation state, but also by
                   soil moisture conditions which may fluctuate. Reduced, wetter soils, or those
                   found near a perched water table are lighter in color.  Oxidizing conditions will
                   have mottles of more distinct colors, e.g., dark reds and browns.  As for soil color
                   notations, mottles  that are reddish or yellowish are more highly oxidized and
                   weathered, whereas soils that are grayish whitish or bluish are more reduced or
                   are in association  with high or stagnant water tables.  In humid regions, mottled
                   soils  with spots of different colors may have fluctuating water tables. Mottles  in
                   these soils may indicate seasonal conditions of wetness even if the soils are
                   examined during drier seasons.  Those mottled  soils streaked with red, yellow, or
                   black in a gray matrix are usually periodically saturated with water.

                   In addition to or in association with mottles, the  soils should be examined for
                   coatings or stains  on the faces of or within aggregates. Crushed or rubbed
                   aggregates may be examined for color characteristics. Mottles, stains, and coats
                   can also indicate accumulations of metal contaminants and should be compared
                   with the soil matrix in unaffected areas off-site.  Close-up photographs and
                   microphotographs may be useful to illustrate or describe these special soil
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                                                                                      Soil/Color
                   features by showing various color combinations in the soil matrix.  Photographs
                   may be especially useful if soil colors are pertinent to accumulations or
                   concentrations of metal contaminants.
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                                                                             Soil/Compaction
OBJECT/ATTRIBUTE:  SOIL/COMPACTION

DEFINITION:        The squeezing together of soil particles under mechanical load by rolling,
                   tamping, or vibration to expel air; usually by the weight of farm, construction, and
                   other equipment; vehicles; and animal and foot traffic.

VALUES:           HIGH
                   MODERATE
                   LOW TO SLIGHT

CATEGORY:        SITE BACKGROUND

PROPERTIES:       INPUT FACT

REFERENCE:       Bradford and Gupta, 1986.
                   Hillel, 1982, pp. 176-199
                   USDA Soil Conservation Service, 1970, pp. 45-47
VALUE:             High

DEFINITION:        Surface soils have been subject to high compaction and consequent effects on
                   soil structure, such as by vehicular and foot traffic or livestock.

CONDITIONS:       Compaction of heavy, fine-textured, clayey soils reduces their porosity and
                   capacity to hold moisture. For light, coarse-textured, sandy soils, compaction
                   reduces porosity, but increases moisture-holding capacity. Aggregation is
                   increased, along with bulk density.  Infiltration rate of surface soils is decreased
                   and runoff is increased.  Disturbed soils are generally more subject to
                   compaction than naturally occurring soils.  Length of liquids standing on the
                   surface is increased, and metal sorption to soil particles is increased.
                   Compaction should not be confused with compression, which can result in a
                   significant change (decrease) of either water or air in the soil pore spaces, a
                   rearrangement of soil particles, compression and deformation of solid particles,
                   and compression of the liquids and gases within the pore spaces.  Some  similar
                   effects on soil metal particle sorption may occur whether the soil is compressed
                   or compacted, except for changes in metal-moisture relationships.
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                                                                              Soil/Compaction
VALUE:            Moderate

DEFINITION:        Surface soils have been less subject to compaction than highly compacted soils,
                   either through reduced applications and frequency of pressure on surface soils,
                   or because the soil structure is more resistant to compaction.

CONDITIONS:      Soil porosity, moisture-holding capacity, aggregation, bulk density, infiltration, and
                   runoff are less affected by compaction than in highly compacted soils.
                   Movement of liquids is less affected, along with  less activity and movement of
                   metal species.
VALUE:            Low to Slight

DEFINITION:        Surface soils have been only slightly affected by compaction, either because of
                   resistance to compaction or because they are less subject to application of
                   compacting stressors.

CONDITIONS:      Surface soils show characteristics more similar to noncompacted or naturally
                   occurring soils and will react similarly to applications of water and chemicals and
                   to sorption of metal species.  If the pore spaces are filled or nearly filled with
                   water or other liquids, very little or no volume change will take place immediately
                   upon  the application  of a load and very little or no air is expelled. If the water or
                   other  liquid can readily drain from highly permeable soil, the consolidation of the
                   soil may take place within a short time  period. If the permeability is low, then
                   complete consolidation under an applied load may require several years.
                   Usually, a low to slight compaction does not result in a significant change of
                   water volume in the soil mass, and therefore has little effect on movement of
                   mobile metal contaminants.
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                                                                             Soil/Consistency
OBJECT/ATTRIBUTE:  SOIL/CONSISTENCY
DEFINITION:
VALUES:
CATEGORY:

PROPERTIES:

REFERENCES:
The resistance of the soil material to deformation or rupture; the degree of
cohesion of the soil mass, and as described at various soil moisture contents.

HIGH
MODERATE
LOW TO WEAK
CEMENTED

SITE BACKGROUND

INPUT FACT

Mason,  1983b, pp. 5-3; 5-12 to 5-14;
USDA Soil Conservation Service, 1981, pp. 4-81 to 4-84
USDA Soil Conservation Service, 1975, pp. 475-477
VALUE:            High

DEFINITION:        A soil when wet that shows high cohesion of soil particles, or adhesion of soil
                   particles to other substances.

CONDITIONS:       The reaction of soil when force is applied is closely related to the soil-water state,
                   and reflects properties primarily of texture, organic matter, and cementing
                   materials (e.g., salts), including certain chemical contaminants.

                   Clay soils tend to be sticky and plastic when wet;  moderately to strongly
                   smeary; fluid to very fluid; moderately firm, very firm to extremely firm.  Review
                   properties of texture, structure, clay minerals, compaction, porosity and soil
                   moisture, particularly for  clay soil characteristics.  There is generally a lower
                   potential for water and liquid chemicals to enter and migrate through a soil of
                   high consistency, and with consequent retention of metal species.

                   Review conditions for determining soil cohesion/adhesion at specified moisture
                   contents and values:  plastic limit; water at maximum stickiness; smeariness at
                   field capacity; fluidity under natural field conditions; and the interrelationships of
                   consistency and soil structure.
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                                                                              Soil/Consistency
VALUE:            Moderate

DEFINITION:        A soil when moist that shows moderate cohesion or adhesion.

CONDITIONS:      The moist soil water condition (e.g., field capacity) reflects consistency related to
                   properties of soils of intermediate texture and reduced amounts of clays and
                   organic matter.  Soils tend to be less sticky and plastic, less smeary, and less
                   firm.  In general, there is a favorable tendency for soil water and liquid chemical
                   movement, with less potential for retention of metal species.
VALUE:            Low to Weak

DEFINITION:        A soil, usually dry, that shows reduced or poor cohesion or adhesion.

CONDITIONS:      The dry soil condition, as for a wet soil, most strongly reflects soil properties of
                   texture,  whether sand, silts, or clays, and varying degrees of  organic matter. Dry
                   clays and finer textured soils will be hard to very hard, nonplastic, firm to
                   extremely firm, nonsticky, nonsmeary and nonfluid, varying in brittleness. Dry
                   sands and  coarse-textured soils lacking significant amounts of clays and organic
                   matter will be loose or soft, friable, nonplastic, nonsticky, nonsmeary, and
                   nonfluid, with strong potential to retain metal species.
VALUE:            Cemented

DEFINITION:        A soil or horizon that remains hard or brittle after an air-dried specimen has been
                   placed in water for at least one hour.

CONDITIONS:      Cemented soils are evaluated both wet and dry.  Cemented materials, after
                   soaking for one hour, are weakly cemented, strongly cemented, or indurated
                   (hard to extremely hard).  Hardness and brittleness persist whether wet, moist, or
                   dry.  Soil particles are held together by cementing substances such as calcium
                   carbonate, or the oxides of silicon, iron, and aluminum.

                   Cemented soils are not favorable for infiltration, penetration, and migration of
                   water and liquid chemicals through the soil.  Some applied chemicals may
                   weaken cementation; compare with adjacent nonaffected soils. There is
                   generally a high potential for retention of metal species, either as part of the
                   cementing process, or independent of it.  Sampling is  unfavorable and may
                   require vigorous mechanical  procedures to break up the soil (e.g., jack hammer).
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                                                                               Soil/Corrosivity
OBJECT/ATTRIBUTE:  SOIL/CORROSIVITY (CORROSION POTENTIAL)
DEFINITION:



VALUES:



CATEGORY:

PROPERTIES:

REFERENCES:
The ability of the soil to wear away and degrade metal materials with time,
usually by chemical and microbial action, and as determined by soil
characteristics.

HIGH
MODERATE
LOW

SITE BACKGROUND

INPUT FACT

Barttelli, 1962
Olson, 1987, pp. 53-55
USDA Soil Conservation Service, 1990
US EPA, 1986b
VALUE:            High

DEFINITION:        The potential ability or status of the soil to degrade metal materials to a high
                   degree.

CONDITIONS:      Corrosion is essentially a redox phenomenon, and much of it is largely bacterial
                   in nature.  The bacteria function as their won electrochemical cells to corrode
                   metals.  Soils with a high potential to degrade buried or partially buried metal
                   materials are generally highly organic soils, peats and mucks, poorly drained, or
                   highly alkaline mineral soils and water with a relatively high dissolved oxygen
                   level.  Corrosivity of metals in soils is promoted by finer textured soils, clays, or
                   salty coarser textured soils, and those with a high or low pH, dark color, high or
                   low oxidation -reduction potential (Eh), high aeration but also high moisture, high
                   shrink and swell potential, cracking, and high amount of  electrolytes in solution
                   (as determined  by electrical conductivity measurement).  Corrosiveness of water
                   tends to increase with decreasing pH. Conditions that favor the growth of
                   microorganisms also will increase corrosivity, and the biodegradation of metal
                   materials.  The tendency of metal surfaces to oxidize is largely responsible for
                   corrosion  and subsequent heavy metal contamination of water. A high corrosivity
                   potential is important for dissolution of metals, the increase in toxicity of a
                   particular  site, and availability for transport and spread of metal ions.  Most rates
                   of corrosion are normally slow.
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                                                                                  Soil/Corrosivity
VALUE:             Moderate

DEFINITION:        Soils that have a medium potential for corrosion of buried or partially buried
                    materials.
CONDITIONS:      These soils tend to be less organic; of medium to coarse texture; exhibit less
                   extreme pH; are moderately chemically reactive; less oxidative; exhibit less
                   potential for cracking, shrinking, and swelling; and exhibit less influence of soil
                   moisture and proximity of the water table. Electrical conductivity values of
                   extracts are lower than for highly organic or for salty, alkaline soils.  (See Soil
                   Electrical Conductivity).  Chemical reactivity  and microbial biodegradation  rates
                   are slower,  but movement of corrosive products may be greater in well-drained
                   soils of medium to coarse texture.
VALUE:             Low

DEFINITION:         Corrosion potential of buried or partially buried metal materials is discernibly less
                    evident, or almost nil, over a relatively long period (several years to decades).

CONDITIONS:       Loose,  coarse-textured, dry, nonmoist and nonsalty, nonalkaline soils with low
                    electrical conductivity will show low corrosion potential over an extended period.
                    Microbial corrosion and chemical reactivity will be slow unless other soil
                    conditions and foreign materials, such as wood and other organic products for
                    energy and nutrition, are present and are in contact with metals. Transport of
                    products of corrosion is reduced  unless water is present and erosion forces are
                    operative.  Close proximity to water table or to irrigation can be accelerating
                    factors for enhancement of corrosion and movement of erosion products,
                    including corrosion of metal containers,  dumped or spilled metal products, and
                    leakage of liquids from corroded containers, both surface and subsurface.
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                                                                    Soil/Electrical Conductivity
OBJECT/ATTRIBUTE: SOIL/ELECTRICAL CONDUCTIVITY
DEFINITION:
VALUES:
CATEGORY:

PROPERTIES:

REFERENCES:
The ratio of the electrical current density to the electric field in the soil; expressed
in the reciprocal value of its resistivity in mhos/cm (or mmhos/cm) of soil extract
or paste and generally referable to the salt/solute content of the soil or
determined at a given moisture content and temperature.  Note:  The
International System (SI Units) is Siemens per meter, Sm"1. To convert mhos/cm
to Sm"1, multiply by 0.1.

NONSALINE
SLIGHTLY SALINE
MODERATELY SALINE
VERY SALINE
EXTREMELY SALINE

SITE BACKGROUND

INPUT FACT

Finkl,  1979a
Rhodes and Oster, 1986
Richards, 1954
VALUE:            Nonsaline

DEFINITION:        The conductivity of the saturation extract is < 2 mmhos/cm and the total salt
                   content is estimated at < 0.1%.

CONDITIONS:       The electrical conductivity, total ionic concentration, and osmotic pressure of the
                   soil solution (extracts) are positively correlated and can be related to important
                   effects on natural vegetation, crops, and soils.  For a nonsaline soil, the salinity
                   effects for most plants and crops are negligible. For hazardous wastes,
                   contaminant salts, if present, and unless from soluble toxic compounds, would
                   not affect site vegetation or soil properties. Porous, well-drained soils would
                   show little effect of any contaminant salts.  Usually found in naturally occurring
                   soils of humid regions.
Guide to Site and Soil Description
                         4-22

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                                                                       Soil/Electrical Conductivity
VALUE:            Slightly Saline

DEFINITION:       The conductivity of the saturation extract is 2 to 4 mmhos/cm, and the total salt
                   content is estimated at 0.1 to 0.15%.

CONDITIONS:      Sensitive vegetation  and yields of very sensitive crops may be restricted.
                   Compare suspected salt contamination with off-site vegetation.
VALUE:             Moderately Saline

DEFINITION:         The conductivity of the saturation extract is 4 to 8 mmhos/cm, and the total salt
                    content is estimated at 0.15 to 0.35%

CONDITIONS:       Vegetation growth and yields of many crops are restricted.  Compare any
                    suspected salt contamination with off-site vegetation. Note sources of moisture,
                    e.g., irrigation water, evidences of moisture retention, evaporation rates
                    conducive to salt deposition and retention, and other soil properties conducive to
                    salt accumulation, whether of natural or induced sources. Biodegradation of any
                    accompanying organic contamination is impeded  due to osmotic and other
                    adverse salt effects.  Some corrosive effects of salts may be evident, and interact
                    with metal contaminants if moisture is sufficient.
VALUE:            Very Saline

DEFINITION:        The conductivity of the saturation extract is 8 to 16 mmhos/cm, and the total salt
                   content is 0.35 to 0.70%.

CONDITIONS:      Vegetative growth is restricted, with sparsity of vegetation or evidence of
                   halophytes. Only salt-tolerant crops will yield satisfactorily.  Salt accumulation
                   may be noticeable at the soil surface or within the soil profile.  Biodegradation is
                   inhibited.  Corrosive  effects of salts may be evident for metal materials, especially
                   if moisture is sufficient.  Arid land soils and irrigated soils in acidic regions may
                   be affected.
Guide to Site and Soil Description
4-23

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                                                                       Soil/Electrical Conductivity
VALUE:

DEFINITION:


CONDITIONS:
Extremely Saline

The conductivity of the saturation extract is >
content is > 0.70%.
16 mmhos/cm, and the total salt
Vegetative growth becomes more restrictive, or even absent in extreme situations
of salt accumulation, with evidence of halophytes.  Only a very few tolerant crops
will yield satisfactorily because of the effects of excess soluble salts.  Salts from
contaminating sources exacerbate the situation for macro and microorganism
growth and activity.  Halotolerance will be evident,  but biodegradation is
generally very restricted.  Corrosive effects of salts on metals can be particularly
evident  if there is sufficient moisture.   Arid land soils and  soils irrigated for a
number of years may be affected.  Nonsaline (alkali) sodic soils,  high in
exchangeable sodium,  also should be noted for their adverse effects on
vegetation and soil properties (e.g., structure), and interactions with metal
species.
Guide to Site and Soil Description
                          4-24

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                                                                           Soil/Fertility Potential
OBJECT/ATTRIBUTE:   SOIL/FERTILITY POTENTIAL
DEFINITION:
VALUES:



CATEGORY:

PROPERTIES:

REFERENCES:
The ability or status of the soil to supply nutrients necessary for plant growth,
usually determined by soil tests (i.e., chemical, physical, or biological procedures
that estimate a property of the soil pertinent to the suitability of the soil to support
plant growth).

HIGH
MEDIUM
LOW

SITE BACKGROUND

INPUT FACT

Barber,  1984
Hendricks and Alexander, 1957
Jones, 1979
Plaster,  1985, pp. 171-192
Sanchez, Conto, and Buol, 1982
Soon, 1985
Tisdale and  Nelson, 1975, pp. 439-490
VALUE:            High

DEFINITION:        The potential ability or status of the soil to readily supply nutrients necessary for
                   plant growth.

CONDITIONS:      Specific soil tests should be made to determine the nutrient status, both macro
                   and micro nutrients of the soil.  Tests may be performed for nitrogen, carbon,
                   phosphorus, potassium, sulfur and others and for their availability for plant
                   growth. General observations of the luxuriant nature  and healthy condition of
                   plant growth during the growing season are indicative of a fertile soil. In general,
                   those characteristics indicative  of high  fertility are a favorable clay and organic
                   (humus) content, a loamy texture, and  good soil structure. Indicators of a highly
                   fertile soil are warm, deep, moist soil with good drainage and tilth; less
                   susceptibility or evidence of erosion; usually, a pH near neutral; favorable  nutrient
                   supply; and desirable  microorganisms. A fertile soil generally has a greater
                   capability to naturally recover from contamination, or to enhance remedial  actions
                   taken to reduce or clean up contamination.  Interference of contaminant metals is
                   not evident or effective, and potential for recovery from metal contamination may
                   be more favorable than for soils with less fertility potential. (Fertility should not be
Guide to Site and Soil Description
                          4-25

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                                                                            Soil/Fertility Potential
                   confused with productivity. A productive soil has chemical, physical, and
                   biological characteristics favorable for the economic production of crops suitable
                   for a particular area.)
VALUE:            Moderate

DEFINITION:        A soil with moderate potential or status to supply nutrients for plant growth.

CONDITIONS:      Specific soil tests indicate the need for some additions of one or more nutrients
                   to obtain optimal plant growth.  In general, a moderately fertile soil shows less
                   clay minerals and organic (humus) content, some structural aberrations, a less
                   warm,  moist, and moderate soil depth with some impeded drainage, increased
                   evidence of erosion, less favorable tilth, a pH less favorable than neutral (too acid
                   or too  alkaline for most plants),  a less favorable nutrient supply,  and a reduction
                   in the numbers and kinds of microorganisms relative to a highly fertile soil. The
                   soil will respond to improvement in soil conditions, and plants will show some
                   response to nutrient additions by increased absorption and growth
                   characteristics.  Moderately fertile soils generally will not recover as fast as highly
                   fertile soils from contamination under natural conditions.
VALUE:            Low

DEFINITION:        A soil with low potential or status to supply nutrients for plant growth.

CONDITIONS:      These soils have an undesirably high clay or sand content and associated
                   characteristics, and otherwise may show unfavorable physical characteristics of
                   either extremely rapid or poor drainage, erosion and loss of top soil and organic
                   matter, unfavorable manipulations resulting in compactions and reduced
                   penetration and infiltration, poor tilth, shallow depth of soil, high degree of rock
                   fragments and of nonsoil materials or debris, cold or excessively hot
                   temperatures, a too dry or too wet condition, pH that is too acid or alkaline for
                   most plants, a highly reduced or oxidized condition, inadequate or unfavorable
                   microorganisms, and  imbalanced or inadequate nutrient supply.   Fertility of
                   some soils may  be improved by amelioration of soil physical characteristics and
                   additions of nutrients to improve plant growth.  Contamination of these soils may
                   exacerbate already unfavorable conditions. Amelioration and cleanup may be
                   difficult.  Site usage and spread of contaminants, as well as other  factors, will
                   determine treatments and the necessity to enhance fertility status to promote
                   plant growth, recovery of the site, and improvement of some soil properties.
Guide to Site and Soil Description
4-26

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                                                                                Soil/Horizons
OBJECT/ATTRIBUTE:  SOIL/HORIZONS
DEFINITION:
VALUES:
A soil horizon is a layer of soil or soil material approximately parallel to the land
surface and differing from adjacent genetically related layers in physical,
chemical, and biological properties or characteristics such as color, structure,
texture, consistency, kinds and numbers of organisms present, degree of acidity
or alkalinity, etc.

MASTERS AND LAYERS
TRANSITIONAL
DISTURBED
BURIED
CATEGORY:
SITE BACKGROUND
PROPERTIES:
INPUT FACT
REFERENCES:
Soil Science Society of America, 1987
USDA Soil Survey Staff, 1960, 1975, 1990, 1991
VALUE:             Masters and Layers

DEFINITION:        Distinguishing master horizons and layers recognized in soil survey and
                   represented by the capital letters O, A, E, B, C, and additional symbols of lower
                   case letters and arabic numbers.

CONDITIONS:       Soil horizons are described from the surface downward, and using the Master
                   Horizon and Layer letter designations  of O, A, B, C, and R.  Further subdivisions
                   use other number and symbols.  The letter A is commonly used to designate the
                   surface horizon or layer commonly known as topsoil.  The letters B and C are
                   used to describe subsoil horizons.  The letter R describes hard bedrock.

                   A basic description of master horizons and layers is given below. For further
                   description and extensive details needed to classify soils, refer to the above
                   references.

                   An experienced scientist familiar with the particular area of concern should  be
                   contacted if possible, otherwise site documents, including local soil surveys
                   should be consulted. Soil classification includes further grouping of horizons into
                   series (approximately 10,000 in the United States), families,  subgroups, great
                   groups, suborders, and orders (10).
Guide to Site and Soil Description
                         4-27

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                                                                                  Soil/Horizons
                              MASTER HORIZONS AND LAYERS

                   O horizons—Layers dominated by organic material, except limnic layers that are
                   organic.

                   A horizons—Mineral horizons that formed at the surface or below an O horizon
                   and (i) are characterized by an accumulation of humified organic matter
                   intimately mixed with the mineral fraction and not dominated by properties
                   characteristic of E or B horizons; or (ii) 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 combinations 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 0 horizon and are
                   dominated by  (i) carbonates, gypsum, or silica, alone or in combination; (ii)
                   evidence of removal of carbonates; (iii) concentrations of sesquioxides: (iv)
                   alterations that form silicate clay; (v) formation of  granular, blocky, or prismatic
                   structure; or (vi) combination or 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  indurate
                   limestone or sandstone that is sufficiently coherent to make  hand digging
                   impractical.

                   Important physical, mineral, chemical, and biological factors are characteristic of
                   the various soil horizons within the pedon. These characteristics, in turn, as well
                   as external environmental factors - soil forming factors - determine the
                   development and extent of soil horizons.  A diagnosis of soil horizons, therefore,
                   yields important information relative to the soil, its nature and behavior.  The
                   characteristics of soil horizons are important to the movement, translocation,
                   mobility and accumulation of various solutes and contaminants,  such  as the
                   chemicals in wastes. An examination of the soil profile and  its exposed horizons
                   at toxic and hazardous waste sites should be compared with off-site analysis of
                   horizons of the soil profile.
Guide to Site and Soil Description              4-28

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                                                                                   Soil/Horizons
VALUE:            Transitional

DEFINITION:        A soil that possesses properties and distinguishing characteristics of two kinds of
                   horizons, one superimposed on the other, or with parts characteristic of another.

CONDITIONS:      There are two kinds of recognized horizons: (1) properties of an underlying or
                   overlying horizon are superimposed on properties of the other horizon
                   throughout the transition zone.and (2) parts that are characteristics of an
                   overlying or underlying horizon are enclosed by parts that are characteristic of
                   the other horizon. In soil survey, special conventions and symbols are used to
                   designate these horizons. Usually eight transitional horizons are recognized.
                   (See Keys to Soil Taxonomy by Soil Survey Staff, SMSS Tech. Monogr. No. 19,
                   1990 and other soil taxonomy  references for details.) Transitional layers should
                   be identified not only as part of the soil description, but insofar as they may
                   affect changes in movement, translocation, reactivity, sorption, and accumulation
                   of chemicals including metals  in or from waste materials.
VALUE:             Disturbed

DEFINITION:         Any soil that has been truncated or manipulated to the extent that its principle
                    pedogenic characteristics have been severely altered or can no longer be
                    recognized.

CONDITIONS:       Disturbed soils may be found in nature due to environmental events such as
                    tectonic events, floods, landslides, and erosional removal of distinguishing
                    horizons.

                    Disturbed soils are a distinguishing characteristic of reclaimed mine lands, where
                    soil is replaced as a material, and it has severely lost or suffered alteration of its
                    original characteristics such as structure, porosity, permeability,  organic matter,
                    exchange capacity, pH-Eh, hydraulic conductivity and other moisture features,
                    and various microbial,  meso- and macro-biotic components, their activities and
                    relationships.  A new soil will develop in these areas, dependent upon soil
                    forming factors.

                    Disturbed soils also may be characteristic of waste sites, especially if removed
                    and subsequently replaced. Characteristics of the disturbed soil should then be
                    compared with off-site soils occurring in the undisturbed or natural  environment.
                    Reactivity, fate, and transport of contaminants in the disturbed soil also may be
                    compared with off-site soils.
Guide to Site and Soil Description
4-29

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                                                                                  Soil/Horizons
VALUE:            Buried

DEFINITION:        Soil covered by an alluvial, loessal, or other depositional surface mantle of new
                   material usually to a depth greater than the thickness of the solum.

CONDITIONS:      The surface mantle of new material is usually 50 cm or thicker.  A mantle < 30
                   cm thick is not considered in taxonomy of buried soils.  The surface mantle of
                   new material is usually defined as unaltered. In the natural environment it is
                   usually finely stratified and overlies a soil horizon sequence that can be clearly
                   defined as the solum of a buried soil in at least part of the pedon.  Wind and
                   water deposits of soil, as well as landslides can result in buried soils in the
                   natural environment.

                   Buried soils can  also be identified at some excavated and filled areas, such as
                   landfills and at waste sites where soil has been removed and replaced with trash
                   or waste materials, and/or subsequently covered with a layer of excavated soil.
                   Attention should be given to characterizing and describing the resultant
                   overlaying soil materials and their development, and interaction with underlying
                   materials, as well as effects on the buried soils, e.g., leaching and/or
                   accumulation of  chemicals from the overlying wastes. Buried soils also may be
                   separated by liners of various areal extent, depth and composition and these
                   may be checked for leaks into the surrounding soil.
Guide to Site and Soil Description
4-30

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                                                                   Soil/Hydraulic Conductivity
OBJECT/ATTRIBUTE: SOIL/HYDRAULIC CONDUCTIVITY
DEFINITION:
VALUES:
CATEGORY:

PROPERTIES:

REFERENCES:
The rate of water movement within the soil; the proportionality factor in Darcy's
Law as applied to the viscous flow of water in the soil, i.e., the flux of water per
unit gradient of hydraulic potential.

Hydraulic Conductivity (K) Saturated - The ratio of the flux density to the
hydraulic gradient, or the slope of the flux versus gradient curve in a water
saturated medium (e.g., soil).

Hydraulic Conductivity (K) Unsaturated - The ratio of the flux density to the
hydraulic gradient, or the slope of the flux versus gradient curve in an
unsaturated medium (e.g., soil).

HIGH
MODERATE
LOW
IMPERVIOUS

SITE BACKGROUND

INPUT FACT

Amoozegar and Warrick, 1986
Bouwer, 1979, pp. 99-102
Brooks and Corey, 1964
Green, Ahuja, and Chong, 1986
Hillel,  1982, pp. 57-132
Klute and Dirksen, 1986
Lee, et al., 1985
Mason, 1983b, pp. 5-21 to 5-23
Reynolds and Elrick, 1986
Reynolds, el al.,  1985
Talsma, 1960
USDA Soil Conservation Service, 1981, pp. 4-35 to 4-37
US EPA, 1986b
Guide to Site and Soil Description
                         4-31

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                                                                      Soil/Hydraulic Conductivity
VALUE:            High

DEFINITION:        > 10jLim/s (.000001 meters/second).

CONDITIONS:      Hydraulic conductivity is a complex phenomenon in soil. Hydraulic conductivity
                   and hydraulic gradient are routinely obtained during hydrogeological
                   investigations.  For this reason, simple "theory" as well as a practical
                   understanding of hydraulic conductivity are presented in this frame.

                   Transmission of liquids in the unsaturated (vadose) zone is critical in the design
                   and monitoring of near-surface hazardous waste storage and disposal sites, land
                   treatment facilities, irrigation and drainage systems, canals and reservoirs, tailings
                   areas, septic tank systems and a number of other agricultural, industrial, and
                   environmental installations.

                   Hydraulic conductivity (K) is the proportionality factor in Darcy's equation and
                   relates the velocity (v) of water in a soil or other porous medium to the hydraulic
                   gradient (/) as follows: v = K/.  The velocity is the gross velocity, or Darcy velocity
                   as if the water (or chemical) were also moving through the solid particles of the
                   medium (soil).  The hydraulic gradient / is the rate of  decrease in the total head
                   (the sum of pressure head and elevation head)  along a streamline in the
                   direction of flow.  It should be  noted that the Darcy equation is not valid for all
                   flow in porous media.

                   Hydraulic conductivity is universally proportional to the viscosity of the water,
                   therefore, temperature should  be specified for a certain K value.  Both the
                   hydraulic conductivity concept and Darcy's equations are based on laminar flow.
                   Subsurface water flow is usually laminar although turbulent flow may occur in
                   media with large pores and  high hydraulic gradients.   Flow in porous media is
                   given in Reynolds numbers  and is based on the Darcy velocity and the average
                   particle size diameter.  For most subsurface flow systems,  the Reynolds Number
                   is <  1, well below the range of turbulent flow.

                   Hydraulic conductivity, as a measure of the ease with which  water moves through
                   the soil is greatly dependent upon soil  properties, particularly the sizes and
                   configurations of the pores.  Anything affecting  the pore configuration will affect
                   K, including entrapment of air in some of the pores, which will reduce the pore
                   area  available for water flow, and hence K is reduced. Because of air in pores,
                   the K of unsaturated soil (vadose zone) is much lower than K at saturation.

                   The concentrations and composition of cations in the soil water determines
                   whether or not the clay particles in the soil are flocculated or dispersed.  These
                   in turn determine the structure of the soil and hence  also affect K.
Guide to Site and Soil Description
4-32

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                                                                      Soil/Hydraulic Conductivity
                   Hydraulic conductivity, can be directional (anisotropy), and affected by
                   groundwater, aquifers, basins, and soil horizons and layers. It can be given for
                   the soil as a whole or for a particular layer or combination of layers. The layer
                   with the lowest value determines the hydraulic conductivity classification for the
                   soil.

                   Hydraulic conductivity is highly variable.  Measured values for a particular soil
                   series can vary by 100-fold or more.  Values measured on soil samples taken
                   only centimeters apart may vary by 10-fold or more.  Furthermore, laboratory-
                   determined  values are generally higher than field-measured values,  often by as
                   much as 100-fold. Because of this variability, a single measured value is a poor
                   indicator of  a soil's hydraulic conductivity. An average of several values gives  a
                   reliable estimate that can be used to place the soil into a particular  hydraulic
                   conductivity class.

                   A distinction is made between saturated hydraulic conductivity and  unsaturated
                   hydraulic conductivity. Saturated flow occurs when soil water pressure is
                   positive.  It is the greatest rate  at which water can move through the soil.  In
                   most soils, water pressure is possible when about 95 percent or more of the total
                   pore space is filled with water.  If the soil remains saturated for a long time
                   (several months or more) the proportion of total  pore space filled with water may
                   approach 100 percent.  Saturated hydraulic conductivity is a function of such soil
                   properties as pore size distribution, pore geometry, total porosity (water-filled
                   porosity at saturation), and clay mineralogy.

                   Three of the most important parameters governing liquid transmission include
                   field-saturated hydraulic conductivity, sorptivity, and hydraulic conductivity which
                   establish the pressure head relationship. Sorptivity is a  measure of the capacity
                   of a porous medium to absorb a wetting liquid; usually, the greater  the sorptivity,
                   the greater the volume of a wetting liquid that can be absorbed, and the more
                   rapidly the liquid is absorbed.  Sorptivity is dependent upon the pressure head.
                   As the pressure head decreases, then the hydraulic conductivity decreases  from
                   the field-saturated hydraulic conductivity in an exponential fashion.

                   Unlike the saturated zone, soil  pores in the unsaturated  zone are not completely
                   filled with liquid (water or chemicals).  However,  all unsaturated zone soil
                   contains some measurable amount of water.  Unsaturated zone soils generally
                   do not accumulate water for any appreciable period of time, but they can hold
                   large volumes of water at relatively high soil water matric potentials.

                   Water flow is unsaturated when the soil water is subject to a subatmospheric
                   pressure. It is under a negative pressure potential.  Unsaturated hydraulic
                   conductivity is a function of the same soil properties as saturated hydraulic
                   conductivity and  also of the soil water content (water-filled porosity). Unsaturated
Guide to Site and Soil Description               4.33

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                                                                      Soil/Hydraulic Conductivity
                   flow is always slower than saturated flow. The moving force is always greater at
                   the wetting front zone, where water invades and advances into an originally
                   relatively dry soil.  The most important difference between unsaturated and
                   saturated flow is probably in the hydraulic conductivity.
                   In the pressure head relationship for unsaturated flow, the change in hydraulic
                   conductivity also decreases as the pressure head decreases; this decrease is in
                   an exponential fashion, indicating that the pressure head relationship is
                   hysteretic.  Dependent upon the porous medium properties there will be different
                   values depending upon whether the porous medium is wetting or draining and
                   how long it has been wetting or draining before flow is reversed.

                   Solution of unsaturated flow  problems usually requires predetermination of the
                   soil hydraulic properties, namely,  (i) the relationship between the capillary head,
                   i|r, and the moisture content, o, and (ii)  the dependence of the hydraulic
                   conductivity, K, upon the moisture content (sometimes their derivatives are
                   applied as a matter of convenience).  It would be desirable to determine all
                   necessary data by direct measurements, but often this is impossible for one or
                   more of the following reasons:
                   1. The measurements are costly and time-consuming.
                   2. The hydraulic properties of soils are of a hysteretical nature.  Different
                   relationships prevail for wetting and drying processes, and the actual
                   relationships between K, \|r, and 0, depend upon the preceding history.
                   3. The soil variability is such  that  the amount of data required to represent the
                   hydraulic properties accurately is enormous.
                   4. The values of hydraulic conductivity of some soils may vary by  several orders
                   of magnitude.  Systems can  not efficiently cover such a wide range.
                   5. The available experimental data can not represent the complete relationships
                   describing the hydraulic properties.

                   Hydraulic  conductivity does not describe the ability of soils in their natural setting
                   to dispose of water internally.  A soil may  have a very high conductivity yet
                   contain free water because there are restricting layers below the soil, or because
                   the soil is  in a depression where  water from surrounding areas accumulates
                   faster than it can pass through the soil. The water may actually move very slowly
                   despite the soil's high conductivity. Actually, rate of water movement is a
                   product of the hydraulic conductivity and the hydraulic gradient. Saturated
                   hydraulic conductivity cannot be  used to describe water movement  under
                   unsaturated conditions.

                   Soils that  have high conductivity, such as gravels or deep sands, commonly
                   transmit liquids downward so readily that the soil remains  set for no  more than a
                   few hours after wetting. These soils have large connected pores. The layer of
Guide to Site and Soil Description              4.34

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                                                                      Soil/Hydraulic Conductivity
                   soil or soil pedon has many continuous conducting pores that are usually
                   medium to coarse.  The size and continuity of pores are the critical factors.
                   Many pores are large enough to be distinguished easily; their continuity and
                   persistence when the soil is wet must be determined. Some medium- and fine-
                   textured layers have strong granular structure and large connecting pores.
                   Others have many large voids, pores, or root channels that transmit water
                   rapidly.  If the soil cracks when dry, the cracks may not close on wetting.
                   Hydraulic conductivity of clean gravels can be 50-1000 m/day; natural sand and
                   gravel mixes, 10-100 m/day; and coarse sand, 5-20 m/day.  (See Table 4-31 for a
                   comparison of hydraulic conductivity class limits in equivalent units).  Metals and
                   other contaminants in solution will move rapidly in soils  with high hydraulic
                   conductivity values. In general, there will be little absorptivity on soil particles.

                   Hydraulic conductivity classes in soil survey are defined in terms of vertical
                   saturated hydraulic conductivity.  Unsaturated hydraulic conductivity  classes
                   cannot be defined at this time. Since measured values  of hydraulic conductivity
                   are available on relatively few soils, estimates are based on soil properties and
                   on correlations that have been made between properties and hydraulic
                   conductivity measurements.

                   A number of field methods  have been developed for in situ measurement of field-
                   saturated hydraulic conductivity, sorptivity and the pressure head relationship,
                   but few of these methods can  measure all three parameters and many are not
                   cost effective due to large equipment, personnel, time, and liquid  refinements;
                   however, the Guelph Permeameter is capable of simultaneous, in situ
                   measurements.

            TABLE 4-2.  Saturated hydraulic conductivity class limits in equivalent units.
^/m/s
100 =
10 =
1
0.1 =
0.01 =
m/s
10'4
10-5
10'6
io-7
10'8
cm/day
864.
86.4
8.64
0.864
0.0864
in/hr
14.17
1.417
0.1417
0.01417
0.001417
cm/hr
36.0
3.60
0.360
0.0360
0.00360
kg s m"3
1.02X10*
1.02X103
1.02X104
1.02X10'5
1.02X10'6
m3 s kg "3
1.02X10-8
1.02X10'9
1.02X1 010
1.02X10'11
1.02X10'12
Guide to Site and Soil Description
4-35

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                                                                     Soil/Hydraulic Conductivity
VALUE:            Moderate

DEFINITION:        0.1 to 10pm/s

CONDITIONS:       Soils commonly transmit water downward readily enough so that they remain wet
                   for no more than a few days after thorough setting.  Layers may be massive,
                   granular, blocky, prismatic, or weakly platy if they contain common continuous
                   pores.  If the soil cracks when dry, the cracks may not close on setting.  This
                   class includes many soils considered favorable for rooting and for supplying
                   water to plants.  Medium sands will have a hydraulic conductivity of 2-5 m/day;
                   fine sands, 1-2 m/day; and, loams, 0.1-1 m/day. Solutes and contaminants will
                   not be transported as readily as in coarse soils with  higher conductivity values,
                   thereby  increasing their retention time in the soil pore-water system, and delaying
                   their movement into water bodies such as ground water or large aquifers.
VALUE:            Low

DEFINITION:        0.01 to 0.1 /j m/s

CONDITIONS:      Soils commonly transmit water downward so slowly that they remain wet for a
                   week or more after thorough wetting.  Soils in the low class are structureless or
                   have only fine and discontinuous pores (as in some clays, fragipans, or
                   cemented layers).  Layers may be massive, blocky, or platy.  Structural plates or
                   blocks commonly are overlapping.  There are few connecting pores that could
                   conduct water when the soil is wet.  If the soil cracks when dry, the cracks close
                   completely on wetting.  Plant roots are usually few or absent  and are localized
                   along the cracks.  Slickensides and continuous stress surfaces also indicate low
                   hydraulic conductivity.

                   In dense or structured clays, the water moves through the very fine pores
                   between  clay particles.  Sandy clays, silts,  and some loams, mixture of
                   sands.silts, and clay may be included in this class.  A certain threshold gradient
                   may be necessary to initiate water movement through such fine pores. Because
                   the surfaces of clay particles are negatively charged, they will absorb cations.
                   Considerable concentrations of cations, including metal contaminant ions may,
                   therefore, concentrate in these soils with very fine pores and  become absorbed
                   on soil particles. The hydraulic conductivity is <  0.1 m/day and approaching
                   zero in dispersed clays.
Guide to Site and Soil Description
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                                                                    Soil/Hydraulic Conductivity
VALUE:            Inhibited

DEFINITION:        < 0.01 fj m/s

CONDITIONS:       The hydraulic conductivity class indicates practically impenetrable and
                   impermeable soil conditions either because of homogenous clays, which may be
                   satiated, the soils are naturally hydrophobic, or hydrophobic through the addition
                   of waste substances. Water and applied chemicals remain on the surface for
                   very long periods, or depend upon certain environmental circumstances, such as
                   runoff for removal. Metal contaminant retention in solution may be high;
                   comparisons should be made between on-site and off-site areas.
Guide to Site and Soil Description              4.37

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                                                                      Infiltration and Percolation
OBJECT/ATTRIBUTE:
SITE/SOIL INFILTRATION AND PERCOLATION
DEFINITION:        Infiltration (penetration): The downward entry (penetration) of water into the soil
                   through the soil surface.

                   Percolation: The downward movement of water through the soil.

VALUES:           HIGH
                   MEDIUM
                   LOW
                   INHIBITED

CATEGORY:        SITE BACKGROUND

PROPERTIES:       INPUT FACT

REFERENCE:       Bouwer, 1982
                   Hill, 1979
                   Hillel, 1982
                   Morel-Seytoux, 1979
                   Musgrave and Holtan, 1964, pp. 12-1  to 12-30
VALUE:            High

DEFINITION:        Infiltration and percolation rates > 5 cm/hr. (> 2 in/hr)

CONDITIONS:      In nature, infiltration and percolation are seldom uniform, either because of
                   surface features, texture, structure, porosity, initial degree or state of wetness,
                   etc.  As water penetrates the soil, its distribution in space and time varies. For a
                   given soil, depending on its permeability and capillary characteristics, the
                   infiltration capacity will vary according to whether or not the soil was initially dry
                   or already fairly wet when water or a liquid chemical is added.  Soil structure will
                   determine the direction of water movement.  Prismatic and columnar structure
                   enhance vertical percolation; blocky and granular structure enhance percolation
                   both vertically and horizontally.  Biological effects on infiltration can include
                   growth of microorganisms on the soil surface. Algae, lichens, bacteria, fungi and
                   also mosses can affect infiltration by their accumulation of biomass, metabolic
                   products, entrapment of gases and binding with soil particles.  Determination of
                   infiltration rate is important to predicting surface runoff (and therefore
                   streamflow), the movement of solutes and mobilized metals through the soil
                   profile.
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                   4-38

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                                                                        Infiltration and Percolation
                    In loose sands, the infiltration and rate of movement in a uniform profile can be
                    expected to exceed 20 mm/hr. However, soil crustiness, such as from raindrops,
                    windblown materials, etc. may initially impede infiltration, and discontinuities, e.g.,
                    weak pans, may alter uniform progress of percolation and wetting zone.  As an
                    example, in one typical situation,  upon encountering a coarse (sandy layer of
                    higher saturated hydraulic conductivity overlying a less conductive finer-textured
                    (loamy  or clay) layer, the infiltration rate is at first controlled by the coarse layer,
                    but when the wetting front reaches and penetrates into the finer-textured layer,
                    the infiltration rate can be expected to drop and tend to that solely of the finer-
                    textured soil.  In the opposite situation, with a fine-textured layer over a coarse-
                    textured one, infiltration is again determined by the upper layer.  However, as
                    water reaches  in interface with the coarse lower layer, infiltration may decrease.

                    In normal, as well as contaminated soils, nutrients and/or ions penetrate  and
                    percolate through the soil profile, and are usually impeded or slowed by
                    differences  of soil horizons and discontinuities in many soil profiles.  In sites
                    disturbed by the addition of toxic or hazardous wastes, dissolved contaminants
                    may infiltrate and percolate into and through the soil at an expected rate
                    determined by uniformity of soil properties, but where horizons and
                    discontinuities  are evident, variations in concentrations of contaminants may also
                    occur.
VALUE:             Medium

DEFINITION:         Infiltration and percolation rates 1.5 to 5 cm/hr. (0.6 to 2.0 in/hr)

CONDITIONS:       In sandy and silty soils, rates commonly vary from 10 to 20 mm/hr.  In loams,
                    rates vary from 5 to 10 mm/hr.  Variations in these rates for natural occurring,
                    undisturbed soils may be attributed to surface and subsurface horizons and
                    conditions,  irregularities and discontinuities as described above. In toxic or
                    hazardous waste sites, soil conditions may have been altered and the expected
                    infiltration and percolation rates may not occur.  Such deviations from expected
                    values should be compared with off-site determinations and an analysis made for
                    contaminants.
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                                                                       Infiltration and Percolation
VALUE:             Low

DEFINITION:         Infiltration and percolation rates 0.15 to 1.5 cm/hr. (0.06 to 0.6 in/hr)

CONDITIONS:       Low or restricted infiltration rates are typical of clayey soils or those with claypans
                    or other restrictive pans, severe compaction of finer soil materials, severely
                    reduced porosity, and other alteration of the soil surface or profile to  limit
                    infiltration and penetration of liquids. Platey structures  restrict vertical
                    percolation.  In agriculture, puddled soils, commonly clays,  are manipulated,
                    dense, massive and artificially compacted when wet and can have severely
                    reduced infiltration and  percolation rates. Clayey soils  are not conducive for
                    penetration and movement of either water or applied chemicals.  Surface and
                    shallow accumulations of contaminants may be evident at hazardous waste sites
                    having clayey soils.  See soil texture classes, clays.
VALUE:             Inhibited

DEFINITION:         < 0.15 cm/hr (0.06 in/hr)

CONDITIONS:       There is very slow or no water or liquid chemical movement into or through soil.
                    Internal soil properties or external environmental factors greatly restrict the
                    movement of liquids applied to the soil surface or through the soil. Sodic clayey
                    soils exhibit this property. Repellency can be observed in naturally occurring
                    soils due to climate (temperature) surface or subsurface hardness, or cracking,
                    aggregation, compaction and formation of dense surface crusts and  exposed
                    surface pans with restricted porosity, occlusions due to detachment and
                    migration of  pore-blocking particles, or from the swelling of clay, from the
                    entrapment of air bubbles or bulk compression of soil air.  Soils of deforested
                    and cultivated tropical regions, and some desert soils with caliche and other
                    hardened salts may show inhibited infiltration of percolation.

                    In toxic or hazardous waste sites, the prior application, infiltration  and percolation
                    of liquid chemicals may have so altered the soil surface and structure that liquids
                    can no longer penetrate the soil surface or move through the soil. In special
                    cases, ponding over the soil surface and the submergence of the soil, has so
                    altered the soil surface, or the subsurface soil  is so saturated that percolation
                    can no longer be measured. Under conditions of initial shallow ponding,
                    infiltrability and percolation may vary and decrease with time, depending  on the
                    initial wetness and water potential factors of the soil.   Ponds over soil at toxic or
                    hazardous waste sites also should be sampled for contaminants.
Guide to Site and Soil Description
4-40

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                                                             Soil/Mesofauna and Macrofauna
OBJECT/ATTRIBUTE:
       SOIL/MESOFAUNA AND MACROFAUNA
DEFINITION:
VALUES:
CATEGORY:

PROPERTIES:

REFERENCES:
Soil Mesofauna - Soil-inhabiting animals smaller than soil microbiota
(microorganisms), including nematodes, small oligochaete worms (Enchythaeids),
small insect larvae, and the microarthropods; of the latter, the soil mites
(Acarina), springtails (Collembola) are often the most abundant permanent soil
inhabitants.

Soil Macrofauna - Soil-inhabiting biota that generally include the larger insects,
earthworms (Lumbricidae) and other organisms which can be easily sorted by
hand; and commonly include burrowing vertebrates, such as moles, ground
squirrels, and pocket gophers, which affect soil structure.

MANY
COMMON
FEW
NONE

SITE BACKGROUND

INPUT FACT

Borror and White, 1970
Cloudsley-Thompson, 1988
Eisenbeis and Wichard, 1987
Kevan, 1962
Kevan and Hill, 1979
Kuehnelt, 1961
Ricklefs, 1979
Schaller, 1968
Wallwork, 1970, 1976
Woolley, 1982
VALUE:

DEFINITION:


CONDITIONS:
Many

Mesofauna > 100,000 to > 10,000,000/m2;
Macrofauna > 5/m2 to 10/m2 of soil.

Many kinds and activities of mesobiota and macrobiota, primarily soil animals, will
have a significant effect on the soil.  (Small and large animals not associated with
the soil, e.g., foxes, deer or cattle, are not included as soil macrofauna, but
should be noted and described if present). These effects include modifications
Guide to Site and Soil Description
                        4-41

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                                                               Soil/Mesofauna and Macrofauna
                   of soil structure and consequent effects on infiltration and penetration of liquids,
                   increase in number and kinds of pores, increase in aeration and permeability,
                   hydraulic conductivity, water retention or movement, aggregation, increase in
                   organic matter decomposition and other soil factors.  Soil runoff and/or erosion
                   also may be influenced by the number and activities if the surface soil is greatly
                   disturbed or loosened. Animals to note include mites, ants, millipedes, cicada
                   larvae, beetles, grubs, earthworms, sowbugs, slugs, snails, and small mammals:
                   mice, moles, prairie dogs, gophers, shrews, woodchucks, squirrels, and rabbits;
                   reptiles:  snakes, lizards and tortoises. Ground-nesting birds also may be
                   included.

                   Soil macrobiota can be readily seen with the naked eye.  Soil macrofauna
                   commonly include earthworms, larger molluses, slugs, snails, and larger
                   arthropods that can be measure in cm. Larger soil mesofauna can generally be
                   seen with the  naked eye, are >100jum long, (although many nematodes are
                   microscopic),  and include many of the enchythaeid worms and the smaller
                   molluscs and  smaller arthropods. Small mesobiotic forms are  seen mostly near
                   the surface of the soil, or in the "A" horizon (see soil horizons).  More than 80
                   percent of all  known soil animal species are arthropods - the most diverse of soil
                   inhabitants. The most abundant soil arthropods are mites (arachnida and
                   acarina)  and springtails (collembola). The larger soil animals are sometimes
                   described as "megafauna," because they utilize the soil primarily as a habitat and
                   not as an energy source or for other soil biota interactions.

                   Many soils will have a large diversity and abundance of mesofauna, especially in
                   highly vegetated  areas or where soils have favorable systems of pH-Eh, nutrients,
                   organic matter, porosity, and structure, etc.  Translocation of materials is
                   oftentimes promoted from one soil horizon to another by  the burrowing of soil
                   animals.  Their holes or borrows form open channels which carry air, water,
                   nutrients as well as contaminants into the deeper layers.  Complex networks may
                   be formed which are capable of impounding great quantities of water, solutes
                   and contaminants.

                   Irregular tubar streaks, known as Krotovinas, may appear within one soil horizon
                   consisting of soil materials transported from another horizon, and caused by the
                   filling of tunnels made by burrowing animals, Effects of soil animals on the soil
                   system, their numbers, kinds and diversity should be compared with analyses
                   and observations of uncontaminated off-site areas and with various soil
                   contaminants.
Guide to Site and Soil Description              4.42

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                                                               Soil/Mesofauna and Macrofauna
VALUE:            Common

DEFINITION:        Mesofauna > 100 to approximately 100,000/m2 of soil;
                   Macrofauna approximately 5/m2 to 10/m2 of soil.

CONDITIONS:      Less abundant, less diverse, and lesser volume, but still showing significant
                   influences on soil properties, and on the mixing and changing of soil materials
                   with less effects on the overall soil system. Soils of forests, grasslands and semi-
                   arid areas will show greater abundance and diversity than arid areas.  Compare
                   effects on  soil animals, their numbers, kinds and diversity with uncontaminated
                   off-site areas, and the observations and analysis of various contaminants.
VALUE:            Few

DEFINITION:        Mesofauna >10 to approximately 100/m2 of soil;
                   Macrofauna 1 to 5/m2 to 10/m2 of soil.

CONDITIONS:      A very low number of mesofauna and only a few macrofauna can be detected.
                   The natural environment is itself  restrictive, e.g., lack of available moisture, limited
                   available nutrients, limited organic matter, restrictive temperature and temperature
                   regime,  compaction, or other soil and site characteristics, such as found in desert
                   or compacted soils.  Contaminating wastes may be present in what otherwise
                   may seem to be "normal" soils and should be compared with uncontaminated off-
                   site areas and analyses for various contaminants.
VALUE:            None or only an occasional meso or macrofauna detected per specified unit of
                   surface area, 1/m2 to 10/m2.

CONDITIONS:      The natural environment is extremely adverse for meso and macrofauna and
                   generally lacking in vegetation and/or limiting soil properties, e.g., extremely
                   barren and isolated deserts, or toxic and hazardous wastes which have greatly
                   affected the soil environment to eliminate or prohibit the habitation and activities
                   of meso and macrofauna.  Megafauna, as well as small and large animals, are
                   also probably lacking in these sites, except as transients.  For recently added
                   contaminants, dead, or dying animals, including birds, (or aquatic biota in
                   transient or permanent ponds), may be evident. Definite comparisons should be
                   made with uncontaminated off-site areas and analyses made for non-observable
                   contaminants.
Guide to Site and Soil Description
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                                                                            Soil/Microbiota
OBJECT/ATTRIBUTE:
       SOIL/MICROBIOTA
DEFINITION:
VALUES:
CATEGORY:

PROPERTIES:

REFERENCES:
Generally, microscopic forms, such as soil algae, especially green and blue
green types and diatoms, autotrophic and heterotrophic bacteria, fungi,
actinomycetes, streptomycetes, myxomycetes and protozoa.

ABUNDANT
COMMON
FEW
NONE

SITE BACKGROUND
INPUT FACT

Alexander, 1973, 1971
Atlas, 1986, 1988
Burns, 1986
Clark, 1957, 1979
Grell, 1973
Hattori, 1979
Huang and Schnitzer, 1986
Jacobs et al., 1957
Kaspar and Tiedje, 1982
Kevan and Hill, 1979
Knowles, 1982
Kuehnelt, 1961
Parkinson and Paul, 1982
Paul and Clark, 1989
Schaller, 1968
Schmidt and Paul, 1982
Shields, 1982
Shtina and Hollerbach, 1979
Silver, et al.,  1986
Stotzky, 1986
Tabatabai, 1982
Wallwork, 1970, 1976
Wollum, 1982
Woolley, 1982
VALUE:           Abundant

DEFINITION:       A large diversity of kinds and/or number of viable metabolic groups of
                  microorganisms, ranging from 1,000,000 to > 10,000,000 microorganisms/g of
                  soil.

CONDITIONS:      Microorganisms can solubilize and oxidize a number of waste constituents.
                  Microbes not lethally affected by the waste product may decompose both the
                  toxic and nontoxic compounds,  particularly organics, into products that can be
                  metabolized further.  Metals can be oxidized  or reduced by at least one type of
                  soil microorganism which may be present at the site, and depending on the
                  availability or lack of free oxygen and other substances in their  habitat.
Guide to Site and Soil Description
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                                                                                 Soil/Microbiota
                   The microbial population within the disposal site depends upon waste
                   composition, concentration of toxic material, nutrients available, oxygen levels,
                   temperature, pH, Eh, moisture content and availability, the initial population found
                   in the waste liquid or solids, and any admixes such as soil.  Aerobic
                   microorganisms may be succeeded by microaerophiles or facultatives, followed
                   by anaerobic species, as oxygen is depleted.  Anaerobic microorganisms may
                   then predominate to generate significant amounts of gases such as methane,
                   hydrogen sulfide, and ammonia that can cause both odor problems and potential
                   explosion hazards.  Microbial activity may change substantially over time and
                   may become more significant as a disposal site ages.  The numbers and/or kinds
                   of microorganisms are large, and usually indicative of a normal and "healthy" soil
                   system.  Depending on the "type" of soil, its depth and conditions,  large numbers
                   of algae, bacteria, fungi, actinomycetes, streptomycetes, and protozoa may be
                   found along with numbers and kinds of aerobes,  microaerophiles, facultatives
                   and anaerobes; various metabolizers, heterotrophes and autotrophes, etc.

                   Nematodes are sometimes considered with the microbiota, but generally live
                   outside of soil macrostructure and obtain great length, and therefore can  be
                   included with the mesofauna.  Because of their agricultural significance,
                   nematodes are often considered separately under Phylum Nematoda. Rotifers,
                   small turbellarians and tardigrades also may be observed.  Rotifers and
                   turbellarians, as both aquatic and soil-inhabiting species, may be very sensitive
                   to pollution.

                   Myxomycetes (slime molds), plasmodial or uncellular,  and sometimes considered
                   intermediate between  fungi and protozoa, should not be overlooked in soils rich
                   in organic matter, including dung. They can spread extensively over the surface
                   layers of moist, highly organic soils where they feed on other microorganisms
                   and help maintain a soil population balance.  They may be inhibited by
                   contaminants, including organics, which can interfere with their activities,
                   including formation of typical fruiting structures.

                   Viruses may be included with soil microbiota, although they are submicroscopic
                   in size.  They can parasitize the other microbiota; organic residues, humus, and
                   clay have considerable potential to absorb viruses.  Presence, absence or
                   variations in viral activities may be indicative of presence of pollutants.

                   Soil (and rock) lichens vary in size from microscopic to macroscopic forms. They
                   are usually not included with the soil microflora.  Soil algae and algal crusts may
                   be attacked by fungi to form lichens. They grow slowly and are important in soil
                   stabilization, some can fix atmospheric nitrogen and they can be indicators of
                   pollution, including acid precipitation and radioactive fallout. Formation and
                   development of soil lichens can be an indication of longer term soil stability.
                   Comparisons should be made  on- and off-site.
Guide to Site and Soil Description              4.45

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                                                                                Soil/Microbiota
                   Mycorrhiza are not soil microorganisms in a strict sense, being an association of
                   fungus hyphae (mold-like threads) in association with the roots of green plants to
                   form modified root structures.  Many trees show this modified  root structure of
                   closely woven masses of fungal hyphae, especially in the surface layers of soil
                   and decaying litter. Mycorrhizae can have considerable influence on uptake of
                   inorganic nutrients, including uptake of essential macro and micronutrients.
                   Mycorrhizal formation may be particularly pronounced in soils  low in phosphorus
                   and nitrogen. Uptake of metals, when levels are relatively low, is enhanced by
                   mycorrhizae, but increased uptake has also been found at toxic  levels, leading to
                   decreased tolerance and reduced growth of the host plant. The extent, nature
                   and development (or  absence) of mycorrhizae in contaminated sites may be
                   compared with off-site areas of similar soils and vegetation.

                   Allchthonous microbiota - those not indigenous to the soil - may enter the soil
                   system in precipitation, manure, sewage, diseased tissues, wastes,  etc. They
                   may persist for some  time, but do not contribute in a significant way to
                   ecologically important transformations or interactions in the soil for an extended
                   period. Make comparisons with indigenous species on- and off-site.

                   Lacking diversity of microorganisms, soil conditions may be temporarily limiting,
                   or because of some inhibition imposed by the presence of wastes.  A large
                   number of a few species of a single taxon, e.g., cyanobacteria, may be indicative
                   of a selective substrate and/or conditions imposed by the waste materials or
                   substance(s) and should be carefully investigated, particularly as waste
                   indicators. Some cyanobacteria, for example, live on sewage  and oil wastes and
                   can tolerate some radioactive wastes. Some other bacteria utilize metals, e.g.,
                   iron, as energy sources. Although such microorganisms can serve as indicators,
                   increasing attention is being given to endemic or site-specific  microorganisms for
                   bioremediation purposes, including various materials and substances in toxic,
                   hazardous, and radioactive waste sites.

                   It should be  noted that considerable care should be taken to sample, handle,
                   store and enumerate  soil microorganisms.  Use of aseptic techniques to avoid
                   introduced contaminants, and therefore bias of samples, is extremely important,
                   along with handling and storage in both field  and  laboratory.  Enumeration by
                   various techniques, e.g., enzymes, DMA probes, various microscopic techniques,
                   e.g., direct count, or culture techniques, e.g.,  plate cultures on selective and
                   elective media, including soil extracts and dilution techniques, can be used to
                   estimate and determine the numbers and kinds of microorganisms. Samples
                   may be taken from soil horizons, various soil structures and locations suspected
                   of contamination; and, comparisons made with samples taken from similar
                   uncontaminated off-site areas.
Guide to Site and Soil Description              4.45

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                                                                                 Soil/Microbiota
VALUE:             Common

DEFINITION:         A diversity and/or number of viable microorganisms can be detected, ranging
                    from > 10,000 to 1,000,000  microorganisms/g of soil.

CONDITIONS:       A diversity of kinds of microorganisms may include those in various phyla or an
                    abundance of one or more species.  Diversity may indicate more normal
                    conditions limited only by soil factors such as temperature, moisture, nutrients,
                    aeration, and pH-Eh, etc. or  low inhibition of wastes.  A restricted diversity may
                    indicate more limiting factors in the soil system and if wastes are present, then
                    the effects of toxics should not be precluded.  One or a few species and
                    metabolizers of a single phylum may be highly indicative of toxic effects. Such
                    microorganisms may be cultured and retained for further study,  including
                    possible site remediation.
VALUE:            Few

DEFINITION:        < 100 to 10,000 total viable microorganisms/g of soil.

CONDITIONS:      Numbers, kinds, and diversity of microorganisms is greatly reduced and may be
                   restricted to favorable or selective microhabitats,  usually where moisture,
                   nutrients, ionic interactions, and pore relationships are conductive to growth and
                   reproduction.  Only a few populations or species of microorganisms may be
                   present and they may be unevenly distributed. Depending on the availability of
                   oxygen, aerobic, microaerophic, or anaerobic metabolisms may prevail.  Unit size
                   of aggregates and fine microstructure (<  0.01 mm) may greatly inhibit or restrict
                   microorganisms.  Microfauna generally live outside the units of microstructure.
                   Most algae and fungi live mainly outside the units of fine microstructure.  Only
                   bacteria, and many actinomycetes and some streptomycetes, can live within the
                   units of fine microstructure; however, large matrixed  colonies and mats of soil
                   cyanobacteria (blue green algae) also may be limited, because of size or habitat
                   outside the units of fine microstructure and to the surface or top few cm soil
                   where light is available.  Hazardous and toxic wastes, especially liquid chemicals
                   may greatly limit the abundance of populations, diversity, and species of a
                   number of microorganisms, or else restrict them to more favorable microhabitats
                   within the soil  system.  Growth,  development, inhibition or toxic effects may be
                   determined on specific culture media, including that  derived from waste
                   materials. Compositing of samples may not accurately indicate the numbers of
                   microorganisms in favorable and select microhabitats.  Compare with
                   microorganisms in similar soils,  if possible, in off-site environments.
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                                                                                Soil/Microbiota
VALUE:            None

DEFINITION:        None or only an occasional viable microorganism of any kind can be
                   detected/gm soil.

CONDITIONS:      Some sites, both natural and disturbed, may not contain any detectable, or only
                   occasional survivable microorganisms.  In the natural environment, conditions
                   may prevail which preclude or prohibit growth, or survivability.  These can include
                   physical and chemical conditions, e.g., volcanic sites, isolated, extremely cold, or
                   dry.sandy or salty deserts.  In some waste sites, lack of a suitable substrate,
                   ionic imbalance, and inhibitory conditions, e.g., toxicity  from  recalcitrant
                   molecules or materials may prohibit survival and/or growth and reproduction of
                   microorganisms for any significant time.  Allochtonous microorganisms or
                   transients may survive temporarily; nonasepsis of sampling tools, procurement,
                   and containers, etc. may account for some microorganisms not otherwise
                   endemic to the site.
Guide to Site and Soil Description
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                                                                  Moisture (Water) Conditions
OBJECT/ATTRIBUTE:
       SITE/SOIL MOISTURE (WATER) CONDITIONS
DEFINITION:        The degree or extent to which a soil holds moisture and is affected by its
                   moisture potential and content, either long or short term.

VALUES:           WET
                   MOIST
                   DRY

CATEGORY:        SITE BACKGROUND
PROPERTIES:

REFERENCES:
INPUT FACT

Bruce and Luxmore, 1986, pp. 663-686
DeHaan and Bolt, 1979
Gardner, 1986, pp.  493-544
Gupte and Larson,  1979
Hillel,  1982, pp. 57-132
Klute,  1986a, pp. 635-662
Richards and Richards, 1957
USDA Soil Conservation Service, 1981, pp. 4-27 to 4-29
Wagenet, 1986,  pp. 1055-1088
. ALUE:            Wet

DEFINITION:        A soil at time of sampling with obviously discernible moisture content as
                   determined by sight and touch, with a high degree of adhesion or cohesion, and
                   resistance to deformation or rupture.  See soil consistency:  high.

CONDITIONS:       An increased amount of water in  surface particles greatly decreases their
                   detachment and transport by wind, but breaks down soil aggregates.  If the
                   surface layer consists of water-stable and chemical-stable aggregates, water and
                   chemicals drain rapidly, but if aggregates are not stable, then large pores
                   disintegrate, and  pore size is narrowed, thereby decreasing mobility of ions.  In
                   completely saturated soils,  all the voids are filled with water or liquid chemicals
                   and promote concentration of solutes. In general, the concentration of the
                   metals in the soil solution is of increased concern, along with their total
                   concentration,  although the total  amounts of the individual  heavy metals in
                   solution are usually very low. There may be little movement of heavy metals into
                   drainage water following continuing applications of raw sewage containing
                   metals.  The heavy metal contents of sludges depend, to a large extent, on the
                   nature of the local industry and on the proportions of industrial and domestic
 Guide to Site and Soil Description
                         4-49

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                                                                    Moisture (Water) Conditions
                   wastes. The contents of individual sludges are highly variable, but ranges of
                   metals are similar.  Zinc is almost always present in the highest amount, followed
                   by copper, although depending on the local industry, lead, chromium or nickel
                   may exceed copper.  Postpone soil sampling if soil is too wet, not only  because
                   of sampling  difficulties, but also because of increased potential for sampling and
                   analytical bias during sample handling, transport, and storage. Wet soil generally
                   cannot be sieved, except with considerable difficulty and expenditure of time.
                   Usually, soils are air-dried before sieving for most soil analyses. Sample bias
                   also may be introduced if an attempt is made to sieve wet samples. Also see
                   knowledge frames on  hydraulic conductivity and redox potential.
VALUE:            Moist

DEFINITION:        A soil at time of sampling with some discernible moisture that is slightly or
                   moderately wet, with a moderate degree of adhesion or cohesion, and moderate
                   to slight resistance to deformation or rupture.  See soil consistency: moderate.

CONDITIONS:      A moist surface soil is less conducive to hydraulic erosive influences than a wet
                   soil, with an increase in soil aggregate formation.  Infiltration and penetration by
                   water and chemicals are promoted, along with drainage and movement through
                   pore spaces. See knowledge frame on infiltration and percolation.
VALUE:            Dry

DEFINITION:        A dry surface soil at time of sampling lacks discernible moisture, either through
                   surface evaporation or percolation to lower depths of the soil profile.  The degree
                   of aggregate formation is low, with a low degree of adhesion or cohesion, and
                   with a high degree of resistance to deformation or rupture, except as modified by
                   texture and structure. See soil consistency:  low to weak.

CONDITIONS:      Depending on soil texture and structure, a dry soil, unless protected by
                   vegetation, is more subject to erosive influences of wind and water, especially to
                   strong winds and sudden, strong, downpours or flooding. Infiltration and
                   penetration by water and chemicals are more likely  affected  by the soil surface
                   conditions than wet or moist soils, and whether the  soil is crusty and hard, or
                   loose and friable. Crust formation is a result of previous wetting and will affect
                   penetration and transport of applied water and  chemicals. Metals sorbed to soil
                   particles, both inorganic and organic, are of greater concern, because soil pores
                   are filled with air,  rather than liquids, but leaching potential is a possibility.
                   Mobility of lead is low, regardless of soil moisture status.  See knowledge frame
Guide to Site and Soil Description
4-50

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                                                                      Moisture (Water) Conditions
                    on nature of heavy metal soil pollutants and section for specific metal or
                    metalloid.
Guide to Site and Soil Description               4.5-1

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                                                                                   Soil/Odor
OBJECT/ATTRIBUTE:  SOIIVODOR
DEFINITION:


VALUES:



CATEGORY:

PROPERTIES:

REFERENCES:
The quality or character of the smell of the soil, especially when dislodged for
olfactory examination.

HIGH
MODERATE TO SLIGHT
NONE

SITE BACKGROUND

INPUT FACT

Hazco, 1987, pp. 4.1.1 to 4.1.3.9 and 4.2.1 to 4.2.19
Mason, 1983b, p. 5-14
McKee and Wolf, 1963, pp. 228-229
US EPA, 1979, pp. 140.1-1 to 140.1-7
VALUE:            High

DEFINITION:        A distinct odor, whether of naturally occurring soil organic materials with a
                   distinctive, pungent, musty odor, or sharp distinct odor from chemical
                   contaminants.

CONDITIONS:       Naturally occurring soils high in organic matter will have pungent musty odors,
                   even more so if they are mucks or peats, but also including forest and grassland
                   soils.  Odors of naturally occurring, undisturbed soils should be compared with
                   soils that are chemically contaminated for any suspected and recognizable
                   chemical odors. Stains and discolorations should be noted. In contaminated
                   soils, organics such as hydrocarbons are a major source of odor, especially
                   neutral fractions, having low threshold concentrations. Aging causes petroleum
                   odors to become musty.  Gasoline may give a strong odor for some time.
                   Among the chemicals responsible for odors, especially noticeable in the soil
                   solution, are  halogens, sulfides, ammonia, turpentine, phenols and cresols,
                   picrates, various hydrocarbons, unsaturated organic pesticides, and many others.

                   Except for cyanide,  contaminants in the CLP "heavy  metal" category may not be
                   evident, but may be suspect if  organic contaminants are detected. Soils that are
                   highly contaminated with  organic chemicals, especially volatiles, should be
                   examined carefully with regard  to odors, and possible resultant personnel health
                   effects. Sampling of noticeably artificially odorous soil should proceed with
                   caution, and with careful examination of contaminated materials for sources of
Guide to Site and Soil Description
                         4-52

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                                                                                     Soil/Odor
                   odors within the soil profile.  It may be necessary for the site safety officer to
                   make a decision about the level of protection needed for sampling personnel.
                   CAUTION:  Do not vigorously inhale odors from any soil.  Even naturally
                   occurring soils may harbor disease-producing microorganisms; inhalation of a
                   large quantity of otherwise harmless microorganisms can be detrimental.
VALUE:            Moderate to Slight

DEFINITION:        A less distinct to faint odor whether from naturally occurring soil organic
                   materials, or from various odor-producing chemical contaminants.

CONDITIONS:      All of the same conditions and characteristics of highly odoriferous soils are
                   applicable to soils having strong or distinct odors, but to a lesser degree.
                   Comparisons should be made within the site for variations in odors, and
                   correlations with various kinds and concentrations of contaminants. Precautions
                   still should be used in testing the soil for odors,  especially contamination on the
                   soil surface as well as within the soil profile.
VALUE:            None

DEFINITION:        No detectable odors by olfactory means, but not to the preclusion of odors
                   detectable by instrumental field analysis.

CONDITIONS:      Visual evidence of surface or subsurface contributions to odor are absent.
                   Organic matter, whether naturally occurring or induced, is generally lacking or nil.
                   Volatile organics,  if previously present, have evaporated or moved into the
                   vadose zone or ground water.  Instrumental field analysis may be performed,
                   such as with a photoionization detector, if more detailed analyses are desired.
                   Contaminating metal species may or may not be present.
Guide to Site and Soil Description
4-53

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                                                                            Organic Matter
OBJECT/ATTRIBUTE:   SOIIVORGANIC MATTER AND LITTER

DEFINITION:       Organic matter:  material of plant or animal origin that decays in the soil to form
                  humus.  Litter:  the surface additions of freshly fallen leaves, twigs, stems,
                  flowers,  fruits, and bark.

VALUES:          ABUNDANT
                  MODERATE
                  SPARSE

CATEGORY:       SITE BACKGROUND
PROPERTIES:

REFERENCES:
INPUT FACT

Armson, 1979, pp. 63-85
Finkl, 1979b
Manahan, 1972
Morrill, et al., 1982
Nelson and Sommers, 1982, pp. 539-579
Schnitzer, 1982,  pp. 581-594
Shaw, 1989
Soil Science Society of America, 1987
VALUE:            Abundant, > 4%

DEFINITION:       Soil and surface organic matter primarily of plant remains in concentrations > 4%
                  of total mineral soil, up to 80% (mucks). Organic soils such as peats, mucks,
                  bogs, and tundra; forest soils; and some rich grasslands.

                  Surface litter:  the surface layer,  usually in forests, of freshly fallen leaves, twigs,
                  stems, flowers, fruits, and black soil.

                  Organic matter: the indigenous organic component of the soil system,  both
                  living and dead, partially or highly decomposed. Roots and microorganisms
                  constitute a high proportion of the living fraction.

                  Humus: the total organic compounds in soil, exclusive of undecayed, partially
                  decomposed or biomass materials.

CONDITIONS:      A large amount of litter and soil organic matter can be observed in dark-colored
                  soils and can retain a large number of  chemicals, forming organometallic
                  compounds. These soils will have a high water-holding and chemical-holding
Guide to Site and Soil Description
                         4-54

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                                                                               Organic Matter
                   capacity, increased friability, and water-stable and chemical-stable structure.
                   Organic matter may be an important sorbent of hazardous compounds.  It is
                   more easily eroded than most mineral compounds and tends to remain in
                   suspension because of its low densities.  As much as 65 to 75% of the organic
                   matter in mineral soils may consist of humic materials with very large surface
                   areas (500 to 800 m2/g) and high cation exchange capacities.  Humus, because
                   of it's large surface area, associated surface properties and functional groups,
                   can serve as a buffer,  and a chelating agent, as well as a general sorbent, all of
                   which are important in the attenuation of hazardous compounds in soils.  Most of
                   the organic matter in soils is comprised of humic substances.

                   Humic substances constitute the most important class of complexing agents that
                   occur naturally in soils. Complexing or chelation of metal ions by humic
                   substances, both soluble and unsoluble, is one of its most important qualities in
                   a metal-organic environment. Iron and aluminum are very strongly bound to
                   humic substances. Other ions, such as divalent nickel, lead, zinc and calcium
                   are intermediate in their binding to humic substances.  Magnesium is rather
                   weakly bound.  Insoluble humic substances, the humins and humic acids, are
                   effective in ion exchange and exchange of organic materials with water and may
                   accumulate large quantities of metals. The more soluble fraction of humus, fulvic
                   acid, dissolves in water and exerts its effects in water solution.  Fulvic acid-type
                   compounds may be responsible for keeping transition-metal ions in solution.
                   Amino acids constitute another class of naturally occurring complexing agents
                   formed from the breakdown of proteins.  They can form very stable complexes
                   with some metal ions,  but binding power is less than for humic substances.  At
                   pH < 6.0 amino groups bind more strongly to cation exchange sites in a mineral
                   matrix.

                   The interaction between  heavy  metals and humic substances has been
                   characterized as chelation, complexalion, and adsorption, as well as many other
                   terms.  Regardless of the term used or the type of chemical bond, heavy metals
                   have a very strong affinity for organic matter in general,  and humic acids in
                   particular. Humic substances have a selectivity for the alkali metal cations.
                   Although a variety of results have been obtained, a generalized listing of metal-
                   humic substance stability constants is given as follows for some metals (divalent
                   forms):

                   lead  > copper > nickel > cobalt  > zinc >  cadmium > iron > manganese

                   Stability constants vary with many factors including pH, Eh and the method used
                   for stability constant determination.

                   Estimates of heavy metal retention times vary considerably. Lead has one of the
                   longer retention times  of any heavy metal and even here the variability in
Guide to Site and Soil Description              4.55

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                                                                                 Organic Matter
                   estimates varies considerably. An estimated mean residence time for forest
                   floors can be 150 to 500 years. Complexation has a strong effect on the
                   equilibrium of lead. When lead is oxidized,  it is strongly bound to the product
                   ion, thus reducing its solubility considerably. Upon oxidation many metals form
                   self-protecting coatings of carbonates, oxides or other insoluble species, which
                   inhibit further chemical reaction.  However, a chelating agent in contact with such
                   metals can result in dissolution of the protective coating, thereby  increasing
                   corrosion and dissolution of metals. Retention times in soils for copper and zinc
                   are much shorter than  for lead regardless of fairly similar heavy metal-organic
                   matter stability constants.  This is considered to be an effect on preferential
                   uptake by vegetation.

                   The organic matter serves as a liquid reservoir for fixed and exchangeable metal
                   ions.  Addition of fluids can promote downward translocation of metals in soil as
                   soluble complexes of organic matter.
VALUE:            Moderate, 2 to 4%

DEFINITION:        Amounts of organic matter of 2 to 4% (or more) are representative of mineral
                   soils, such as are found in some grassland soils and soils with scattered
                   vegetation and their remains. Surface soil is usually discernibly colored by
                   presence of organic matter as compared to lower horizons.

CONDITIONS:      Surface organic  materials are sufficient to affect physical conditions of soils, and
                   with lesser capacity than for highly organic soils.  Organic-clay complexes are
                   important in sorption and fixation of metals. The amount of organic matter is still
                   important in retention and release of water and chemicals.
VALUE:            Sparse, < 2%

DEFINITION:        Amounts of soil organic matter are < 2% or even negligible, as in some highly
                   mineralized, arid land soils, or disturbed soils subjected to turnover or removal of
                   naturally occurring surface soils. Dark-colored organic matter may be too
                   disorganized or too small to be visually recognized.

CONDITIONS:      Soil properties such as texture,  structure, aggregation, consistency, porosity,
                   moisture-holding capacity, color and other soil factors are relatively unaffected by
                   the organic content (especially  >  1 %) being overridden by effects of soil
                   minerals, particularly clays, if present.
Guide to Site and Soil Description
4-56

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                                                                                Soil/Porosity
OBJECT/ATTRIBUTE:  SOIL/POROSITY

DEFINITION:     The volume percentage of the total bulk of soil not occupied by solid particles.
VALUES:
CATEGORY:

PROPERTIES:

REFERENCES:
COARSE
MEDIUM
FINE
VERY FINE

SITE BACKGROUND

INPUT FACT

Finkl,  1979c
Hillel,  1982, pp. 135-151
Marshell and Holmes, 1979, pp. 194-199
USDA Soil Conservation Service, 1981, pp. 4-84 to 4-85
VALUE:          Coarse

DEFINITION:     Pores > 5 mm in diameter.

CONDITIONS:    Interconnected macropores provide free movement of water and chemical liquids.
                General nature of large pores should be compared with descriptions of surface
                features, texture, structure, organic matter, moisture content, hydraulics,
                consistency, root and animal activities (burrows) and other properties that are
                routinely described.  Note any unusual arrangement of voids that facilitate
                movement of liquids: their shape, configuration, and orientation. Pores > 10 mm in
                diameter may be described separately, and if so, then their number and proportion
                of cross section and occupancy should be recorded.  In addition to pore size,
                pores also are described by their quantity and size. The movement of water and
                chemicals is generally rapid through pores of large size but also depends upon the
                shape and arrangement of pores and other soil physical factors. The ability of the
                soil to retain water and chemicals is  reduced and the degree of leaching is
                increased.

                Quantity classes of pores are defined by the numbers of each kind and size per
                unit area - 1 cm2 for very fine and fine pores and 1 dm2 for medium and coarse
                pores. See Boulding, (1991), A Field Pocket Guide, for  charts illustrating an
                estimation of pore size.  All pores smaller than 10 mm in diameter are described by
                the following quantity classes:
Guide to Site and Soil Description
                           4-57

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                                                                                  Soil/Porosity
                  Few:  Less than 1 per unit area of the specified size
                  Common: 1 to 5 per unit area of the specified size
                  Many:  More than 5 per unit area of the specified size

                 Pores > 10 mm in diameter may be described separately.  If described separately
                 they are counted, and the number and proportion of the cross section they occupy
                 is recorded.

                 Most described pores will be either vesicular (approximately spherical or elliptical),
                 or tubular (approximately cylindrical and elongated). Some are irregularly shaped
                 and can be described simply as "irregular" or, if significant, any other shape can be
                 recorded.

                 Pores are assumed to be within the pad (if a soil has pads)  unless otherwise noted.
VALUE:          Medium

DEFINITION:      Pores 2 to 5 mm in diameter.

CONDITIONS:    Interconnected, 2-mm to 5-mm pores still provide relatively free movement of liquids.
                 Many pores, compared to fewer macropores, will provide for significant movement
                 of liquid contaminants  and for contaminants carried in liquids, but movement is also
                 dependent upon shape, configuration, and  orientation as for larger sized pores.
                 Chemical properties, such as pH, Eh, and fertility will  have more of an effect than
                 they will for soils that have larger pores.
VALUE:          Fine

DEFINITION:      Pores 0.5 to 2 mm in diameter.

CONDITIONS:    Finer pores will reduce infiltration, penetration, and percolation rate of water and
                 liquid chemicals, but still allow for significant rate of entry of water and less viscous
                 chemicals unless soil is frozen or otherwise compacted and impeded. Movement
                 within the soil body of liquid chemical contaminants is reduced or impeded.
                 Determine associated soil properties that may restrict or affect flow rates, e.g.
                 texture, structure Consistency, compaction, and structure.
Guide to Site and Soil Description
4-58

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                                                                                  Soil/Porosity
VALUE:          Very Fine

DEFINITION:      Pores < 0.5 mm diameter.

CONDITIONS:    Movement of water and chemical liquids is lessened, unless a few larger pores are
                 present and other soil features do not interfere with movement of liquids (e.g., fine-
                 textured clay soils), and effects of poor structure.  Chemical as well  as other
                 physical soil properties will have a considerable effect on a noticeable slow
                 movement of liquid contaminants.

                 Pores smaller than 0.075 mm in diameter are micro pores and may  be described
                 separately, though this is rarely practical in fieldwork.
Guide to Site and Soil Description              4.59

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                                                                             Soil/Reaction (pH)
OBJECT/ATTRIBUTE:  SOIL/REACTION (pH)
DEFINITION:
VALUES:



CATEGORY:

PROPERTIES:

REFERENCES:
The degree of acidity or alkalinity of a soil, usually expressed as a pH value, and
ranging from extremely acid (< pH 4.5) through very strongly alkaline (pH > 9.1).
Soil pH is the negative logarithm of the hydrogen ion activity, usually of a soil
solution or paste.

ACID
NEUTRAL
ALKALINE

SITE BACKGROUND

INPUT FACT

ASTM, 1988d,  G51-77, pp. 910-911.
Bache, 1979
Coleman and Mehlich, 1957
Richards, 1954, pp. 17-18
USDA Soil Conservation Service, 1983, pp. 603-90 to 603-92
VALUE:          Acid

DEFINITION:      An acidic soil (solution) has a pH value < 6.6 to 7.0 (neutral), with acidity increasing
                 logarithmically with decrease in pH; extremely acid at < pH 3.5 to 4.5.

CONDITIONS:    Soil pH, along with Eh, can have a significant effect on solubility and chemical and
                 microbial reactions occurring at a waste site.  In general, pH affects solubility by
                 alteration of simple solution equilibria, and by direct participation in redox reactions.
                 The soil pH can be greatly affected by the type of waste disposal. Hazardous
                 wastes can contribute to pH change due to their own specific characteristics or by
                 the dissolution of waste materials into the soil liquid fraction.  The Soil Survey Staff
                 (1991) defines a number of gradients of soil pH, defining 13 pH classes.

                 Acidic soils usually are not < pH 4.0; ultra acid is < 3.5. They are found in
                 increasingly humid regions.  Acidic reactions are closely correlated with factors of
                 soil formation, development, and composition.  In strongly mineral acid soils,
                 especially < pH 5.2, the dominant  cation (positively charged ion) is trivalent
                 aluminum, unless an acid clay, which also contains hydrogen ions.  Very acid or
                 peat soils or those with organic acids will contain relatively more free hydrogen
                 ions. In general, application of heavy metals to acid soils will increase their
                 solubility, exchangeability on soil particles, and hence, mobility and leachability into
Guide to Site and Soil Description
                            4-60

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                                                                              Soil/Reaction (pH)
                 the soil solution and movement through the soil profile. Corrodible materials will
                 show an increasing degree and rate of corrosion in increasingly acid soils.  Follow
                 standard procedures and precautions for colorimetric or potentiometric (pH meter)
                 determinations of soil pH in the field; refer to information on soil properties (e.g.,
                 exchange phenomena) for details and interpretation.
VALUE:          Neutral

DEFINITION:     A surface soil (solution) of pH value -7.0 (6.6 to 7.3); a base saturated soil, as
                 compared to an acid soil.

CONDITIONS:    Neutral soils generally have favorable reaction properties, with approximately equal
                 numbers of cations and anions (negatively charged ions) on or near the soil particle
                 surfaces.  Amounts and kinds of finely divided mineral and organic particles are
                 favorable for soil reactions, including some favoring sorption, fixation, exchange,
                 and release of metal ions.  A pH > 6.0 (but < 7.5)  is favorable for most cropping
                 systems.  Note that pH measured in the field may not be the same as in the
                 laboratory, because of effects of carbon dioxide and need for equilibration with the
                 atmosphere, however, because of buffer effects, the value may be similar. A carbon
                 dioxide content of -2% is common in many soils, resulting in a pH of -7.1, but this
                 is also dependent on other soil factors such as organic matter and porosity.
VALUE:          Alkaline

DEFINITION:      A soil (solution) > 7.0 (commonly defined as 7.3 to > 9.1).  Strongly alkaline > 9.0.

CONDITIONS:    Alkaline soils, and some saline soils are more often found in arid climatic regions
                 with high evapotranspiration rates and potential for poor water quality due to
                 dissolved salts. An alkali soil is a salty  soil that contains sufficient sodium to
                 interfere with plant growth; a saline soil is a nonalkaline salty soil with less
                 exchangeable sodium, but with sufficient soluble salts (e.g., carbonates) to interfere
                 with growth of most crop plants; pH is usually < 8.5.  The soluble cations and
                 anions commonly found in saline and alkali soils are calcium, magnesium, sodium,
                 potassium, carbonate, bicarbonate, sulfate,  and chloride.

                 The addition of chemical  liquids to relatively unleached soils of alkaline pH values
                 may lower their pH if their solutions are acidic, but will exacerbate the pH of saline
                 and alkali soils if alkaline. At high pH values metals are strongly adsorbed, largely
                 because the surface charge of manganese and iron oxides  increases with
                 increasing pH.  To maintain maximum adsorption in a soil or waste disposed
Guide to Site and Soil Description
4-61

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                                                                             Soil/Reaction (pH)
                system both a high pH and Eh should be maintained.  The higher pH of alkaline
                soils tends to retard metal solubilization. Although arid zone climatic and soil
                properties may limit movement of applied liquids, other properties will increase
                potential for release and movement (e.g., sudden rainfall, flooding, runoff, and
                erosion by water and wind).

                A large change in soil pH will result in a radical modification of the soil environment.
                Compounds normally held in the soil may precipitate out; others normally insoluble
                may dissolve.  Note any differences in pH and effects at the site with that of the
                surrounding environment.  Consult literature on pH and ion exchange phenomena
                and on characteristics of contaminants before undertaking sampling if effects of pH
                are significant due to applied chemicals (e.g., use special sampling tools,
                techniques, and containers,  if necessary).
Guide to Site and Soil Description              4-62

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                                                                     Soil/Redox Potential (Eh)
OBJECT/ATTRIBUTE-.SOIL/REDOX POTENTIAL (Eh)

DEFINITION:     The potential that is generated between an oxidation or reduction half-reaction and
                the hydrogen electrode in the standard state.

VALUE:          HIGHLY OXIDIZED
                INTERMEDIATE
                HIGHLY REDUCED

CATEGORY:     SITE BACKGROUND

PROPERTIES:    INPUT FACT

REFERENCE:    Baas Becking, et.al., 1960
                Barlett, 1981
                Blanchar and Marshall, 1981
                Hesse, 1971
                Merkle, 1955
                Ralston, 1979
VALUE:          Highly Oxidized

DEFINITION:      The soil system is highly oxidized, approaching values of +700 millivolts (mv).

CONDITIONS:     Through oxidation-reduction reactions metal ions in aqueous solution can obtain
                 stability.  Acid-base reactions, precipitation and complexation use other means.
                 Many of the most important redox reactions are catalyzed by microorganisms.

                 Soil Eh may vary with other factors such as water content, organic matter, oxygen
                 activity in the soil and pH.  Oxidation - reduction processes influence contaminant
                 behavior in soils as much as any biological or chemical factor oxidizing conditions
                 tend to favor attention of contaminants as opposed to reducing conditions.
                 Oxidizing conditions are usually associated with higher pH values than reducing
                 conditions.  Also see knowledge frames on soil reaction, soil microbiota and organic
                 matter.

                 The higher the Eh value, the greater the oxidizing intensity of the soil system.Well-
                 aerated soils range from +700 to +400 mv.  Soil conditions are generally highly
                 aerobic,  dry, or have the pores filled with fresh water, are low in organic matter
                 content,  possess oxidized elements and ions, and high oxides.  Soil "types" are
                 typically found in arid and semi-arid areas, are well drained and are  not compacted
 Guide to Site and Soil Description
4-63

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                                                                       Soil/Redox Potential (Eh)
                 or tightly layered.  The corresponding pH levels are usually high as for alkaline
                 soils.

                 Hydrous oxides of iron, manganese and aluminum, along with organic matter, have
                 an important part in the oxidation - reduction processes in soil. Significant
                 concentrations of iron and manganese oxides may further poise the system toward
                 a high oxidation state, but organic matter and waterlogging may moderate a high
                 oxidation state.  Iron is relatively easily oxidized to ferric ions.  An excess of oxidized
                 manganese may completely immobilize iron to the ferric state, in which conditions it
                 is easily precipitated.

                 Very highly oxidized soils may occur at waste sites subjected to contamination with
                 materials having high oxidizing capacity and intensity and further denoted by a high
                 pH and/or corrosive properties, e.g., caustic materials such as sodium and
                 potassium hydroxide, halogenated solutions, strong brines of common salt (sodium
                 chloride),and other industrial or processing solutions.  With sufficient oxygen
                 present and  nontoxicity of wastes, aerobic microbial activity should prevail.

                 Soil Eh measurements are not as well poised as pH measurements  and results may
                 not be  as concordant as for soil pH. For safety reasons, great care should be
                 taken in regard to sampling and handling highly oxidized, contaminated soils.
                 Precautions also should be taken in regard to field sampling, tools, containers,
                 instruments,  etc., and especially electrodes used to measure redox potentials.
VALUE:          Intermediate

DEFINITION:      The soil system is moderately oxidized or moderately reduced, ranging from
                 approximately +400 to -100 mv.

CONDITIONS:    The values of Eh will depend considerably on available oxygen and other oxidized
                 compounds.  With sufficient (or abundant) oxygen, transition metals - iron,
                 manganese and copper - are present in the soil as oxidized compounds of very low
                 solubility.  Unless there are sufficient poising substances, significant additions of
                 materials can alter the Eh (as well as pH) of the system.  Different soil horizons also
                 may have naturally different states of oxidation or reduction, e.g., an oxidized upper
                 red soil, a lower depth yellow soil, blending into reduced grays, slate-blues and
                 blacks.  Such horizons also may  be altered by the addition of chemical
                 contaminants, and show a change in Eh and/or pH.

                 Most plants flourish  best in a moderably  oxidized soil. Oxidized forms of nutrients
                 constitute the principal nutrient sources;  reduced products, even though present in
                 low concentrations,  are toxic to most cultivated plants.
Guide to Site and Soil Description
4-64

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                                                                      Soil/Redox Potential (Eh)
                 Most microorganisms occur as aerobes, facultatives or microaerophiles in a
                 moderately oxidized or reduced system.  Certain populations of microorganisms
                 can be found in milieus defined by limits of pH-Eh in the natural environment and
                 will be affected as this  milieu changes or shifts with the addition of poise -
                 threatening contaminants. Soil pH-Eh milieu also can provide important information
                 regarding the potential fixation of an element or contaminant in the soil.
VALUE:          Highly Reduced

DEFINITION:      The soil system is highly reduced, with values of -100 to -300 mv or greater.

CONDITIONS:     Soil conditions are generally anaerobic, with high concentrations or organic matter,
                 presence of reduced elements and ions, and are waterlogged,  or with stagnant
                 water.  Soil "types" are generally found where mucks, bogs, and peats occur, as
                 well as where soils are permanently submerged, under water of varying depths and
                 which include bottom deposits and permanent swamps (the water may be fresh or
                 salt); the soils are periodically waterlogged by submergence; soils are affected with
                 a high and fluctuating water table (and sometimes partially aerobic), e.g., paddies.
                 Microorganisms can initiate acute reducing conditions when aeration is poor and
                 there is an abundant supply of oxidizable materials, such as nitrogenous wastes,
                 green plant residues, and  certain readily biodegradable, non- or low-toxic materials.

                 Reducing conditions favor accelerated migration of heavy metals as opposed to
                 oxidizing conditions.  For example, contaminants such as arsenic, beryllium,
                 chromium, copper, iron, nickel, selenium, vanadium and zinc are much more mobile
                 under anaerobic than aerobic soil conditions.

                 Manganese ions are readily reduced to soluble manganous ions and may be
                 leached from the soil. As  the reducing environment becomes more intense, ferrous
                 iron precipitates as gray-green ferroferric hydroxide.  Manganese also becomes
                 solubilized to manganous  ions and may  be leached from the soil or more
                 commonly, translocated to sites where it is precipitated. The ubiquitousness of
                 manganese influences iron mobility as well as other heavy metals, and similar to
                 iron, manganese oxides clog soil pores,  inhibiting the downward flow and
                 percolation of water.

                 The reduction of iron in soils is biologically dominated.  The reduction process is
                 most prominent at low pH values, and under anaerobic conditions when organic
                 matter  is abundant, especially as humus. The presence of sulfate and
                 accompanying sulfate-reducing bacteria also favors iron reduction. Gleying of soils
                 becomes more prominent as soils are reduced, and reduced horizons may appear;
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                                                                       Soil/Redox Potential (Eh)
                 a great majority of soil horizons subject to strong reduction are uniformly gray in
                 color.

                 If the water table fluctuates appreciably,  but the profile remains saturated most of
                 the time, the deeper horizons will have gray backgrounds spotted or streaked with
                 yellowish brown, and give rise to commonly spherical iron or iron-manganese
                 concretions.  Water logging, such as may occur below landfills, favors accelerated
                 mobility of most metal solutes  unless hydrogen  sulfide is produced which unites
                 with metals to form insoluble precipitates.

                 Chemical wastes, including mine wastes, added to reduced soil systems, e.g., acid
                 sulfate  soils such as in the tropics or marshlands, may exacerbate the system if
                 they are strongly acid and corrosive. Acid sulfate soils respond poorly to
                 improvement of drainage. Sludges, manures, and buried vegetation also generally
                 exacerbate a reduced state of the soil system.
Guide to Site and Soil Description              4-66

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                                                                                  Soil/Roots
OBJECT/ATTRIBUTE:SOIL7ROOTS
DEFINITION:
VALUES:
CATEGORY:

PROPERTIES:

REFERENCES:
Usually, the underground parts of seed plant bodies that function as organs of
absorption, aeration, and food storage or as a means of anchorage and support,
and differ from stems, especially in  lacking nodes, buds,and leaves.

MANY
COMMON
FEW
NONE

SITE BACKGROUND

INPUT FACT

Harley, 1979
Miller, 1974
Stern, 1988
USDA Soil Conservation Service,  1981, pp. 4-94 to 4-88.
Weier, et. al, 1982
VALUE:          Many

DEFINITION:     > 5/cm2 for fine and very fine roots; > 5/dm2 for medium and coarse roots.

CONDITIONS:    Quantity, size, and location of roots in the soil should be recorded along with their
                relationships to other soil properties, e.g., soil structure, aggregations, porosity,
                horizons, and whether inside or outside of peds.  In terms of size classes,  roots
                vary from very fine, < 1 mm diameter; fine, 1 to 2 mm diameter; medium, 2 to 5 mm
                diameter; and coarse, 5 mm diameter or larger.  Quantity classes are defined in
                terms of numbers of each size per unit area -1  cm2 for very fine and fine roots and
                1 dm2 for medium and coarse roots.  All  roots smaller than 10 mm diameter are
                described in terms of the above quantity classes; roots > 10 mm diameter are
                described separately.  See Boulding, (1991), A Field Pocket Guide, for charts
                estimating root sizes.

                The location of roots within a soil layer is described in relation to other features of a
                soil horizon or described layer.  Relationships to soil layers,  animal traces,  pores
                and other features are among those to be noted, and to include whether roots are
                inside peds or only follow parting planes between peds. The overall impression of
                the root system, as indicated in the soil profile, their distribution and pattern of
                growth and, depth of penetration should be additionally noted.  Root distribution
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                                                                                     Soil/Roots
                 varies with the type of plant, with the stage of growth and sometimes with plant
                 variety.  Other than root-soil, root-mineral, root-macro, meso, and microbiota
                 interactions, and adsorptive phenomena, roots promote the translocation of water,
                 and provide interfaces for transport of chemicals through the soil system.  See
                 vegetation typical for various climatic regimes in regards to expected kinds of roots,
                 their sizes, development, pattern, distribution, extent, and soil associations. For
                 further details consult the above references.
VALUE:          Common

DEFINITION:      1 to 5/cm2 for fine and very fine roots; 1 to 5 dm2 for medium and coarse roots.

CONDITIONS:    A number of kinds of roots are observable, depending on vegetation types and
                 distribution, soil conditions, and other relationships as described above.  If
                 vegetation is spotty, then statistical methods should be used to estimate the
                 quantity of roots per unit area.  Note if there are any environmental effects including
                 wastes,  on vegetation and  soil relative to root quantity and size as well as their
                 location and distribution. Compare to off-site areas.
VALUE

DEFINITION:


CONDITIONS:
Few

< 1/cm2 for fine and very fine roots;
< 1/dm2 for medium and coarse roots.

There are few observable roots per specified area either because of a limiting
natural environment - climate, water availability, soil conditions, etc. - or presence of
toxic or hazardous wastes have had  an effect on restricting plant germination,
growth, development, and distribution. Note any remnants of possible previous
vegetation or effects on present site vegetation. Site analysis for contaminants and
root effects should be compared with off-site analyses.
VALUE:          None

DEFINITION:      No viable roots.

CONDITIONS:    There are no discernible living roots in the soil system, although dead or decaying
                 roots may be evident. As for other roots,  they may be described accordingly, but
                 with  the notation as to their morbidity or state of decay. In some "healthy" soil
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                                                                                      Soil/Roots
                 systems, no roots may be found in a specified area, especially if climatic conditions
                 or other external conditions severely limit or prohibit plant growth, e.g., extreme and
                 barren deserts, dune soils, salt flats, newly laid down volcanic or alluvial materials,
                 etc.  For toxic and hazardous waste sites there may no longer be any viable roots,
                 or depending on the nature, concentration, release, and translocation of toxic
                 chemicals and ions, the roots may be affected in sporadic areas in the site or slowly
                 responding to contaminated site conditions.  Absence of viable  roots should be
                 compared with off-site areas and analyses of soil contaminants.
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                                                                        Soil/Structure Grades
OBJECT/ATTRIBUTE:  SOIL/STRUCTURE GRADES
DEFINITION:
VALUES:
CATEGORY:

PROPERTIES:

REFERENCES:
A grouping or classification of soil structure (the combination or arrangement of
primary soil particles into secondary particles, units or peds) on the basis of inter-
and intra-aggregate adhesion, cohesion, or stability within the profile.

STRUCTURELESS
WEAK
MODERATE
STRONG

SITE BACKGROUND

INPUT FACT

Mason, 1983b, pp.  5-15 to 5-19
USDA Soil Conservation Service, 1981, pp. 4-70 to 4-74
USDA Soil Conservation Service, 1975, pp. 474-476
VALUE:          Structureless

DEFINITION:     No observable aggregation or no definite and orderly arrangement of natural lines
                of weakness. Massive if coherent. Single grain if noncoherent.

CONDITIONS:    Soil structure greatly influences the growth of plants, the retention and movement of
                solutes, and is needed for determining the classification of soils.

                Surface structure can greatly modify the ability of water and liquid chemicals to
                penetrate into the soil. Structure may vary or show gradations between horizons
                and with depth.  It may modify the influence of texture in regard to moisture and air
                relationships. The type of structure determines the dominant direction of the pores
                and the subsequent direction of water movement in the soil profile. Structure with
                large macropores will have a considerable effect on movement of water and liquid
                chemicals through the soil profile.  Also see knowledge frames for soil horizons. A
                massive soil could be represented by a thick, dense,  plastic clay layer.  A single-
                grain structure is represented by a loose, noncoherent sand.  Sorption of metal
                species depends on factors other than a well-defined structure, e.g., amounts and
                associations of clay, organic matter, salts, pH-Eh, etc.
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                                                                          Soil/Structure Grades
VALUE:          Weak

DEFINITION:      Poorly formed, indistinct peds (natural occurring crumbs, prisms, or blocks in
                 contrast to clods, formed artificially), barely observable in place.

CONDITIONS:    For soils having structure, the shape, size and grade (distinctiveness of peds) are
                 described.  See comments below for shape and size.  For disturbed soils, grades
                 are generally more evident than shape or size.  A weak soil structure modifies the
                 ability of water and liquid chemicals to penetrate into the soil and to percolate
                 through the soil to a lesser degree than a structureless soil.  Soils are less massive,
                 but could still be affected by clay layers. Single-grained structures may show some
                 cohesion,  such as by organic or inorganic interstitial (between grains) materials.
VALUE:          Moderate

DEFINITION:      Well-formed, distinct peds, moderately durable and evident, but not distinct in
                 disturbed soil.

CONDITIONS:    Soil aggregation and cohesion are evident, along with crumb formation as under
                 vegetation. Percolation and infiltration are enhanced with increased opportunity for
                 mobility and transport of ions  under leaching conditions.  There is greater potential
                 for metal species to be affected by structure of soils.
VALUE:          Strong

DEFINITION:     Durable peds are quite evident in undisturbed, unmanipulated soils.  Peds adhere
                 weakly to one another, withstand displacement, and become separated when the
                 soil is disturbed.

CONDITIONS:    Considerable aggregation, such as under grasses, forms an open, porous soil,
                 promoted by some aggregation of clays, saturating ions, and especially organic
                 matter.  The crumbly or granular and friable open structure has open channels that
                 lead to lower soil horizons and facilitate water and chemical infiltration and
                 penetration into the soil.
                 Field terminology for soil structure consists of separate sets of terms designating
                 each of the three properties, which by combination form the names for structure.
                 See Boulding, (1991), A Field Pocket Guide, for illustrations of soil structure shapes
 Guide to Site and Soil Description
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                                                                          Soil/Structure Grades
                 and sizes.  The Soil Conservation Service gives the following notations for soil
                 structure shapes and sizes:

                 Shape: Several basic shapes of peds are recognized in soils. Supplemental
                 statements about the variations in shape of individual peds are needed in detailed
                 descriptions of some soils.  The following terms describe the basic shapes and
                 related arrangement of peds:

                       Platy:  The peds are flat and plate-like.  They are generally oriented
                       horizontally and are usually overlapping. A special form, lenticular platy
                       structure, is recognized for plates that are thickest in the middle and thin
                       toward the edges.

                       Prismatic: The individual peds are bounded by flat or slightly rounded
                       vertical faces.  Peds are distinctly longer vertically, and the faces are typically
                       casts or molds of adjoining peds. Vertices are angular or subrounded; the
                       tops of the prisms are somewhat indistinct and normally flat.

                       Columnar: The peds  are similar to prisms and are  bounded by flat or slightly
                       rounded vertical faces. However, the tops of columns, in contrast to those of
                       prisms, are very distinct and normally rounded.

                       Blocky: The peds are block-like or polyhedral. The peds are bounded by flat
                       or slightly rounded surfaces that are  casts of the faces of surrounding  peds.
                       Blocky peds are nearly equidimensional but grade to prisms, which are
                       longer vertically, and to plates, which are longer horizontally.  The structure is
                       described as angular  blocky if the faces intersect at relatively sharp angles
                       and as subangular blocky if the faces are a mixture of rounded and plane
                       faces and the angles  are mostly rounded.

                       Granular: The peds are approximately spherical  or polyhedral and are
                       bounded by curved or very irregular  faces that are  not casts of adjoining
                       peds.

                 Size:  Five classes are used to describe the size of peds:  very fine, fine,  medium,
                 coarse, and very coarse. The size limits of  the classes  differ according to the
                 shape of the peds. The  classes of size for  the various ped shapes are given in
                 Table 4-3.  The size limits refer to measurements in the smallest dimension of
                 plates, prisms, and columns and to the largest of the nearly equal dimensions of
                 blocks and granules.

                 In some soil  horizons the peds are very much larger than the minimum size given
                 for the very coarse class. If the peds are more than twice the minimum size of "very
                 coarse", the actual size if given:  "prisms 30 to 40 cm across."
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                                                                            Soil/Structure Grades
                 Table 4-3. Size Classes of Soil Structure.  (From USDA SCS, 1981)
Size
Classes
Very fine
Fine
Medium
Coarse
Very Coarse

Platya
(mm)
<1
1-2
2-5
5-10
>10
Shape of
Prismatic and
Columnar (mm)
<10
10-20
20-50
50-1 00
>100
Structure
Blocky
(mm)
<5
5-10
10-20
20-50
>50

Granular
(mm)
<1
1-2
2-5
5-10
>10
          In describing plates, "thin" is used instead of "fine" and "thick" instead of "coarse".
Guide to Site and Soil Description               4.73

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                                                                        Soil/Surface Features
OBJECT/ATTRIBUTE: SOIL/SURFACE FEATURES

DEFINITION:     Conspicuous features on the soil surface that may be examined and described,
                including not only natural features, but distinct artificial features introduced through
                human activities.

VALUES:        PROMINENT
                DISTINCT
                FAINT

CATEGORY:     SITE BACKGROUND

PROPERTIES:    INPUT FACT

REFERENCES:   USDA Soil Conservation Service, 1981, pp. 4-74 to 4-76
VALUE:          Prominent

DEFINITION:     Surface features are conspicuous, without the need for magnification, when
                compared with other smooth, featureless, or unbroken surfaces.

CONDITIONS:    Soil texture, color, stress formations, thickness of features, coatings, packing and
                orientation, amount, location and other properties or combination of properties
                contrast sharply with properties of the adjacent material, or the feature is thick
                enough to be conspicuous. Surface features, artificial or natural, when distinct,
                need to be determined for effects and interference in soil sampling and distribution
                of chemicals. If surface materials are coated with chemicals, they should be
                separated or removed before proceeding with sampling.  Soil-liquid state should be
                noted because some surface features change markedly as the amount of liquids
                changes.  There may be considerable effect on distribution and concentration of
                contaminants.
VALUE:          Distinct

DEFINITION:      Surface features can be detected without magnification, although magnification or
                 additional tests may be needed for positive identification.

CONDITIONS:     A feature or features contrast enough with the adjacent materials that differences in
                 texture, color, or other properties are evident.  There is less necessity to remove or
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                                                                          Soil/Surface Features
                 isolate surface features before proceeding with sampling. There may be some
                 effect on distribution and concentration of contaminants.
VALUE:          Faint

DEFINITION:      Surface features are evident only upon close examination with 10x magnification,
                 and cannot be identified positively in all places without greater magnification.

CONDITIONS:    Contrast with adjacent materials in texture, color, and other properties is small, and
                 probably has not affected distribution and concentrations of contaminants, including
                 metal species.  Sampling does not generally require removal of the relatively
                 homogeneous surface materials.
Guide to Site and Soil Description              4.75

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                                                                           Soil/Temperature
OBJECT/ATTRIBUTE: SOIL/TEMPERATURE

DEFINITION:    The degree of heat of a given body of soil at a particular point in time and space or
               during a particular period of time and at a particular depth or surface extent of soil;
               usually determined in °F or °C.

VALUES:       HIGH
               MEDIUM
               LOW

CATEGORY:    SITE BACKGROUND
PROPERTIES:    INPUT FACT
REFERENCES:
Hillel, 1982, pp. 155-175
Fluker,  1958, pp. 35-46
Taylor and Jackson, 1986
Thompson and Troeh, 1978, pp. 72-77
US DOE, 1987, Appendix E, Section E4.5.1, p. E-129
VALUE:         High

DEFINITION:     Thermal measurement(s) taken on the surface or with depth of soil, at a point in
                time, or over a period of time, with temperatures at or > 38 °C (100.4 °F).

CONDITIONS:    Temperature changes within the contaminated site can occur due to the temperature
                of materials added, redistribution of heat by intruding extraneous water, and heat
                generated by waste decomposition (biological and physical/chemical activity).
                Temperature is important because it influences reaction rates between the liquid
                (water or liquid chemical) and solid (soil) medium.  Moreover, it exerts an influence
                on microbial catalysis.  Both solubility rates and microbial activity increase as
                temperatures rise.

                Soil temperature measurements are generally of value only if measured over a
                period of time, at least for several diel periods.  Temperature measurements may be
                of value in locating local hot spots where temperature is elevated by chemical (or
                biological) activity.  Comparisons may be made at off-site locations.  Normal high
                temperatures are characteristic of thermic and hyperthermic soil temperature
                regimes. High surface  or near-surface temperatures also may be recorded for other
                less thermic soils, depending upon season of the year, weather, exposure and
                slope, soil color, composition, amount and distribution of vegetation, and amount
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                                                                             Soil/Temperature
                and distribution of moisture. Contaminant spread and movement, as well as
                biodegradation, is greatly affected by high soil temperature, especially if moisture is
                available.  Correlative information is necessary for interpretation of soil temperature
                measurements. The spread, movement, and biodegradation of contaminants should
                be cautiously interpreted if it is based solely upon soil temperature measurement,
                especially at a single point and time.
VALUE:         Medium

DEFINITION:     Thermal measurement(s) taken on the surface, or with depth of soil, at a point in
                time, or over a period of time with temperatures 8°C (46.4° F) to 38° (100.4°F).

CONDITIONS:    The same factors as for high temperature soils apply to soils with moderate
                temperatures, except as one or more factors can predominately affect soil
                temperature readings.  These factors should be noted and recorded (e.g., dark,
                barren, unshaded, moist soil, high in organic matter, with high  incidence of solar
                radiation during mid-day and midsummer).
VALUE:         Low

DEFINITION:     Thermal measurement(s) taken on the surface, or with depth of soil, at a point in
                time, or over a period of time, with temperatures predominately < 8 °C  (46.4 °F),  or
                lower.

CONDITIONS:    These are predominately cold soils with a pergelic or cryic temperature  regime. Any
                elevation or differences in soil temperature from off-site nondisturbed soils should be
                noted.  Depending on season, time of day, and certain site and soil characteristics,
                higher point or diel temperature can be recorded.  These may have an  immediate or
                short-term effect on spread and movement of contaminants, and  biodegradation,
                especially at the surface or above the permafrost boundary. Special circumstances
                should be noted for any interpretation and correlation of soil temperature readings at
                these sites.
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                                                                  Soil/Temperature Regimes
OBJECT/ATTRIBUTE:  SOILjTEMPERATURE REGIMES

DEFINITION:    The pattern of soil temperature fluctuations in a soil, characterized by temperature
               distribution with respect to depth, time, and season for a given soil at a given
               location.

VALUES:        PERGELIC
               CRYIC
               FRIGID-ISOFRIGID
               MESIC-ISOMESIC
               THERMIC-ISOTHERMIC
               HYPERTHERMIC-ISOHYPERTHERMIC

CATEGORY:    SITE BACKGROUND

PROPERTIES:   INPUT FACT
REFERENCES:
Fuchs, 1986
Hadas, 1979
Smith, Newhall and Robinson, 1960
Soil Science Society of America, 1987
USDA Forest Service, 1961, pp. 126-128
VALUE:         Pergelic

DEFINITION:    A soil temperature regime (thermal distribution) that has mean annual soil
               temperatures of < 0 °C. Permafrost is present.

CONDITIONS:   Knowledge and information of temperature regimes is useful in predicting both soil
               and contaminant behavior. Contaminant behavior, adsorption,  desorption, and
               mobility will depend considerably on the temperature (and associated moisture)
               regime.

               A cold environment soil: compare with site and soil development and characteristics
               for polar climate, low tundra-type vegetation, and low temperature dependent
               chemical, biotic, and microbiotic activity and processes. Permanently frozen material
               underlies the solum (upper part of soil profile). Upper boundary of the permafrost is
               coincident with the lower limit of seasonal thaw. The climate-driven soil heat flux is
               primarily active during the short summer and under conditions  of low incidence of
               solar radiation, dense  soil vegetative cover, and moisture.  Biodegradation and
               movement of contamination are impeded by low temperature and the permafrost
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                                                                     Soil/Temperature Regimes
                barrier. Penetration of contamination below the surface is limited.  Contamination
                flow is primarily surficial.  Soil Conservation Service maps are available for most of
                the thermic regions in the U.S.
VALUE:         Cryic

DEFINITION:     A soil temperature regime (thermal distribution) that has mean annual soil
                temperatures of > 0 °C but < 8 °C, > 5 °C difference between mean summer and
                mean winter soil temperatures at 50 cm, and cold summer temperatures.

CONDITIONS:    A soil temperature regime found in latitudes, bounding or grading into polar regimes,
                and at lower latitudes and higher elevations inductive of alpine soils and
                ecosystems. Compare with climate, vegetation, and soil characteristics typical for
                this region. Soil dynamics, including microbial processes, are less restricted by soil
                temperatures and heat fluxes. Diurnal and annual periods of heat flux have a
                greater amplitude and to a greater depth than in pergelic soil temperature regimes.
                Evaporation and  melting generally preceding at a more rapid rate and for a greater
                period then for pergelic soils.  Freezing and thawing of soils may promote
                development of macro pores, thereby enhancing the movement of water and
                chemicals into the soil profile.  Spread of contamination is less restricted than for
                soils with pergelic temperatures regimes; subsurface penetration of contamination is
                limited in time and space.
VALUE:         Frigid-lsofrigid

DEFINITION:     A soil temperature regime (thermal distribution) that has mean annual soil
                temperatures of > 0 °C but < 8 °C, > 5 °C difference between mean summer and
                mean winter soil temperatures at 50 cm below the surface, and warm summer
                temperatures.  Isofrigid is the same except the summer and winter temperatures
                differ by < 5 °C.

CONDITIONS:    A soil temperature regime found in northern temperate latitudes and developed
                under favorable conditions of climate, vegetation , microbial activity and processes,
                and other soil forming factors. Surface layers of soil may be able to acquire an
                appreciable amount of moisture from the atmosphere  by condensation when the
                temperature of the air-dry soil is lower than that of the air; the reverse also may
                occur.  Soil moisture will have a more pronounced effect on soil temperature than
                pergelic or cryic soils by variations in specific heat, conductance, surface
                evaporation, and percolation. Lower temperatures will be found in poorly drained
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                                                                   Soil/Temperature Regimes
                soils than in well-drained areas.  Soil moisture is a more important factor in relating
                soil temperature than in pergelic or cryic soil temperature regimes.  Extent and
                movement of contaminants, and biodegradation processes, are increased  because
                of more favorable site and soil temperature-moisture relations.
VALUE:          Mesic-lsomesic

DEFINITION:     A soil temperature regime (thermal distribution) that has mean annual soil
                temperatures of 8 °C or more, but < 15 °C, and > 5 °C difference between mean
                summer and mean winter soil temperatures at 50 cm below the surface.  Isomesic is
                the same except the summer and winter temperatures differ by < 5 °C.

CONDITIONS:    A soil temperature regime found in southern temperate latitudes, and with
                moderating  influences of climate, vegetation,  and soil-forming factors. This soil
                temperature regime is indicative of more moderate temperatures, and with
                accompanying accelerated processes than for a frigid soil temperature regime.
                Opportunities for spread and movement of contaminants are more likely unless soil
                conditions (e.g., poor structure) impede movement.
VALUE:         Thermic-lsothermic

DEFINITION:     A soil temperature regime (thermal distribution) that has mean annual soil
                temperatures of 15 °C or more but < 22 °C, and > 5 °C difference between mean
                summer and mean winter temperatures at 50 cm below the surface.  Isothermic is
                the same  except the summer and winter temperatures differ by < 5 ° C.

CONDITIONS:    These regimes include some thermogenic soils, with properties that have been
                influenced primarily  by high temperatures as a soil-forming factor.  They are
                developed in subtropical and equatorial regions.  Compare with climate, vegetation,
                and soil characteristics for these regions. With moisture available, and other
                favorable  site and soil characteristics, movement of contaminants can be rapid.
VALUE:         Hyperthermic-lsohyperthermic

DEFINITION:     A soil temperature regime (thermal distribution) that has mean annual soil
                temperatures of 22 °C or more and > 5 °C difference between mean summer and
                mean winter soil temperature at 50 cm below the surface.  Isohyperthermic is the
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                                                                     Soil/Temperature Regimes
                same except the summer and winter temperatures differ by <  5 °C.

CONDITIONS:    These regimes are predominately thermogenic soils, with properties that have been
                influenced primarily by high temperatures, unmoderated by extensive periods of
                moisture, as a soil-forming factor. They are developed in arid  and hot desert
                regions.  Compare with climate, sparsity of vegetation, and soil characteristics for
                these regions. Unless sufficient moisture becomes available, spread of contaminants
                is restricted by soil characteristics, and vertical flow is impeded unless soil texture is
                loose and structure is favorable for movement of contaminants. Biodegradation is
                rapid under favorable circumstances (e.g., nature of contaminant, energy, and
                nutrient supply).
Guide to Site and Soil Description             4.31

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                                                                       Soil/Texture Classes
OBJECT/ATTRIBUTE:  SOIL/TEXTURE CLASSES

DEFINITION:    The relative proportions of the various soil separates < 2.0 mm diameter (mineral
               particles of sand, silt, and clay) and described into textural classes on the basis of
               the proportions of the various separates present.

VALUES:       FRAGMENTAL
               SKELETAL
               SANDS
               LOAMS
               SILTS
               CLAYS
               ORGANIC SOILS

CATEGORY:    SITE BACKGROUND

PROPERTIES:   INPUT FACT

REFERENCES:  ASTM D,  1988a, 422-63, pp. 85-86; 87-93; 293-303.
               Dixon and Weed, 1977
               Foth, et al, 1971, pp. 6-11
               Gee and  Bauder, 1986
               Jackson,  Lim and Zelazny, 1986, pp. 101-150
               Mason, 1983b, pp. 5-7 to 5-12
               Soil Science Society of America, 1987
               USDA Forest Service, 1963, pp. 105-115
               USDA Soil Conservation Service, 1983, pp. 603-4 to 603-13
               USDA Soil Conservation Service, 1975, pp. 469-475
               USDA Soil Conservation Service, 1970, pp. 18-20
               US EPA,  1988a,  pp. 5.A.2 to 5.A. 13
VALUE:         Fragmental

DEFINITION:    Any soil or textural composition in which 30% or more of the materials are > 2 mm
               diameter; various size groups of individual soil grains of clay and silt and sand are <
               2 mm diameter; not a distinct soil textural class.

CONDITIONS:   The principal textural classes in soil, in increasing order of the amount of silt and
               clay, (Soil Science Society of America, 1987) are as follows: Sand, loamy sand,
               sandy loam, loam, silt loam, silt, sandy clay  loam, clay loam, silty clay loam, sandy
               clay, silty clay, and clay. These class names are modified to indicate the size of the
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                                                                            Soil/Texture Classes
                sand fraction or the presence of gravel, cobbles, and stones.  For example, terms
                such as loamy fine sand, very fine sandy loam, gravelly loam, stony clay, and cobbly
                loam, are used on detailed soil  maps. These terms apply only to individual soil
                horizons or to the surface layer of a soil type (map unit). (See "Note" at the end of
                this frame in regard to classification scheme presented in A Field Pocket Guide
                (Boulding,  1991.)

                Gravelly, cobbley, stony,  or bouldery sites may be encountered in the field, such as
                in moraines, mountain soils, and eroded areas, or disturbed areas such as
                construction sites, gravel pits, waste disposal sites, and mined sites. Rarely are
                such areas used for agricultural purposes.  They may have been used for disposal
                of hazardous materials as a convenience, or because of their low economic value
                and  use for any other purpose.  Such sites  may have been used for a distinct waste
                repository site, with direct evidence  of dumpage-containers and liquids.
                Contaminants may accumulate  around gravels, cobbles, etc., as well as saturate the
                underlying and intermixed soil, bedrock,  and aquifer or drainage system, both
                surface and subsurface.  Stony soils are good conductors of heat and tend to make
                heavy, dense soils more  permeable to water and air, thereby hastening
                biodegradation.  If scattered on the  surface, stony materials may serve as barriers to
                evaporation of fluids and increase soil moisture retention at the soil  surface and with
                depth. Stones tend to increase channeling  and passageways around them, and
                thereby increase infiltration of contaminating fluids into the soil itself. Contamination
                is easily and rapidly spread in loose, noncohesive sandy soils.  Biodegradation can
                be rapid if  energy substrate and nutrients and other soil conditions are favorable.
VALUE:         Skeletal

DEFINITION:     Mineral grains, resistant siliceous and organic bodies larger than colloidal size.

CONDITIONS:   This grouping represents minerals and organics comprised of individual grains that
                are relatively stable, not readily translocated, are concentrated or reorganized by
                soil-forming processes.  It is not in accordance with a designated SCS textural class,
                but is included here as defined because of its significance to possible accumulation
                and concentration and/or release of hazardous waste solutes, including metals on
                the surfaces of skeletal grains and bodies. There particles can have important
                effects on various physical and physicochemical soil properties and behavior.
                Mineral grains, in addition to quartz, could be represented by carbonates, halides,
                sulfides and sulfates, which are more commonly associated with soils of alkaline
                reaction but have relatively high solubilities and rates of dissolution compared to
                silica minerals in soils.
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                                                                           Soil/Texture Classes
                In acid sulfate soils, depending on whether the reaction is reduction or oxidation
                (moderated by microorganisms), sulfides are produced under reduction, and acid
                under oxidation.  Sulfidic sediments are commonly silty clays or silty clay loams high
                in organic matter. Peats are often associated with sulfidic sediments and with a
                sulfidic accumulation in the mineral soil just beneath the contact with the peat.  If
                sulfides sediments are drained then the oxidation phase of acid sulfate soil formation
                commences.  These are important reactions for the behavior, dissolution and the
                potential for migration of sorbed soil  metals.

                Silica, and tectosilicates, e.g., feldspar, exert a secondary influence on most
                physicochemical properties in soils, including surface area, ion exchange, moisture
                retention, plasticity,  cohesion, shrink-well, and porosity. They serve as a dilutent to
                the much more reactive clay mineral components.  Silica minerals, in general, have
                little surface charge and the specific surface area is also small.  Silica surfaces are
                not highly hydrated.  Except when silica particles are cemented together by organic
                matter, sesquioxides (iron and/or aluminum), silica, carbonates or other cementing
                agents, the cohesive forces binding the particles together are relatively weak.  As the
                silica content of cohesive soils increases, then adhesion, cohesion, shrink-swell,
                CEC, surface area, moisture retention, plasticity limits, capillary fringe, compression
                and compaction  decrease.

                The hydrous oxides of iron, manganese and aluminum are quite common in soils,
                occurring as crystalline minerals or as surface coatings on other minerals.  They are
                characterized by a very high surface area to weight ratio and are frequently
                amorphous (without definite form). Many hydrous oxide surfaces generate a
                significant number of positive changes as the pH decreases.  Hydrous oxides
                provide important adsorption surfaces for metal contaminants and are therefore
                important to the  retention of heavy metals in soils. Metal ions tend to become
                unhydrolized as the pH decreases.
VALUE:         Sands

DEFINITION:     Depending upon the classification scheme (USDA), sandy, or coarse-textured soils
                are 50 to 100% particle sizes between 2.0 mm and 0.05 mm diameter as determined
                by graded sieves.  Individual particles feel gritty when the soil is rubbed between the
                fingers. Not plastic or sticky when moist.

CONDITIONS:   Coarse textured soils (sands and loamy sands) are usually loose and unstable, and
                are very susceptible to wind erosion.  Individual grains can be easily  seen or felt.  If
                squeezed in the hand when dry, the soil will fall apart when the pressure is released
                (the hand is opened). If squeezed when moist, the soil will form a discernable cast,
Guide to Site and Soil Description
4-84

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                                                                            Soil/Texture Classes
                but will crumble when touched. They are highly permeable, and infiltration and
                movement of liquids is rapid under gravity flow.

                Contamination is easily and rapidly spread in loose, noncohesive sandy soils.
                Biodegradation can be significant if substrate, energy, nutrients, and other soil
                conditions are favorable.  See Soil Texture Triangle for all textured grades.
VALUE:         Loams

DEFINITION:     This textural class is for soils having a moderate amount or mixture of sand, silt and
                clay.  Loamy soils are an intermediate textural class. They contain between 7 to
                27% clay; 28 to 50% silt, and < 52% sand.  Depending upon the percentages of
                sand, silt and clay, loams form poor to medium ribbons when moist, and medium to
                soft clods when dry. Loams feel somewhat gritty, yet are fairly smooth and plastic.

CONDITIONS:   Soils are usually a mixture of textural classes of sands, silts and clays, and a few %
                organic matter. Loams range from moderately course-textured to moderately fine-
                textured soils.  They constitute more than half of textural soils. Most soils of
                agricultural importance are some type of loam, and constitute soils of generally
                favorable physical characteristics for crop production.  Loams tend to moisten
                quickly to moderately, penetration is relatively easy, infiltration and percolation are
                relatively quick to moderate, and the soil tills easily. There is moderate to relatively
                fast movement of contaminants, both surface and subsurface, which makes if difficult
                to confine fluids in these soils.  Contamination of these soils, particularly in
                agricultural areas, is to be avoided.
VALUE:         Silts

DEFINITION:     Individual mineral particles of these soils range in diameter between the upper size
                of clay, 0.002 mm, and the lower size of very fine sand, 0.05 mm. Soils of these
                textural classes contain 40% or more silt.  A silt soil contains 80% or more of silt,  and
                < 12% clay. Silts feel smooth  and powdery when rubbed between the fingers. They
                are only moderately plastic or sticky when moist, and have a floury feel when dry or
                pulverized.

CONDITIONS:   Silts are generally medium to moderately fine-textured soils, not as loose as sandy
                soils, nor as tight as clay soils. They form moderate to hard clods when dry,
                depending  upon the percentages of sand and clay.  Infiltration, penetration and
Guide to Site and Soil Description
4-85

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                                                                           Soil/Texture Classes
                movement of liquids is not as rapid as for loams.  Silts are more dense, less well
                aerated and may be more poorly drained than sandy soils or loams.  Silts are
                composed of minerals resistant to weathering, but to a lesser degree than sands.
                Retention of contaminants, including metal species, on silt-size particles is increased
                compared to loams or sands.
VALUE:         Clays

DEFINITION:     Clayey soils are heavy-textured soils containing 27% or more of clay materials. A
                clay soil itself is defined as containing 40% or more of clay, < 45% sand, and < 40%
                silt. The particle size range for clays is  < 0.002 m or less.  The moist soil is plastic,
                pliable, and feels sticky. When moistened it can be easily molded to form a wire-like
                ribbon.  Clays feel smooth and not gritty to the touch.

CONDITIONS:   Clays are the finest textured of all the soil classes. Clays feel smooth and not gritty
                to the touch. Although they contain the greatest percentage of pore space, the pore
                diameters are extremely small, thereby restricting the flow of liquids.  There  is a high
                capacity for retention and exchange of ions and nutrients, and considerable effort is
                necessary to solubilize and remove contaminants. Leaching of clays is a
                considerable problem, and especially for the  iron and aluminum hydrous oxide clays
                found in the tropics.  The silicate clays of temperate  regions (kaolinite,
                montmorillonite and illite) also present considerable difficulties.  Bioremediation is
                restricted in clay soils because of such factors as poor aeration and movement of
                liquids, and especially if drainage is impeded.

                As for all textured class determinations, if a more precise determination is desired to
                determine the amounts of sands, silts, and clays, then appropriate samples should
                be collected for determination of particle size distribution.  Analysis can be made by
                the hydrometer or pipette method, and with subsequent reference to a soil textural
                triangle for textural class.  See Soil Clay Minerals for further information.
VALUE:         Organic Soils

DEFINITION:     A soil composed of 30% organic matter or more; not a mineral soil textural class;
                may have an oily feel, may stain the fingers, and may release water if squeezed
                when saturated.

CONDITIONS:   Organic soils are generally saturated with water for prolonged periods and in various
                stages of decomposition.  The remainder of the soil separates are clay, sand and silt
Guide to Site and Soil Description
4-86

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                                                                           Soil/Texture Classes
                fractions.  Peats, bogs, mucks, tundra and forest soils may contain a high
                percentage of organic matter.  The most obvious and significant addition of forest
                soils is organic matter, primarily as soil surface litter; in grasslands, the major
                additions are from roots.  In local areas, atmospheric components such as SOX and
                NOX, along with heavy metals may be added to the soil organic matter. Chelation of
                heavy metals with soil organic matter can increase their toxicity. The colloidal
                material of organic matter has a great capacity to hold liquids, as well as nutrient
                and contaminant metal ions, thereby increasing potential toxicity of sorbed
                contaminants. Contaminants are spread primarily by wind and water, and  especially
                if vegetation is killed and the soil exposed to erosional forces.  Leaching will remove
                contaminants in the soil solution and  in suspension. Depending on the nature of the
                contaminant, biodegradation may be  impeded or accelerated in organic soils.

                The organic matter itself is continually subject  to decomposition by microorganisms,
                unless toxic, and is generally in an  active state of decay.  Organic soils are not
                included in the soil textural triangle or usually determined by method of feel.  In the
                field, it can best be estimated by visual examination of the soil sample, and by
                application of an oxidizing agent, such as peroxide. See knowledge frame on Soil
                Organic Matter for further details.
                Note: In A Field Pocket Guide (Boulding, 1991), the particle size classes for textural
                differential of soils at the family level are as follows:

                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 of 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% very fine sand; clay
                <35%; rocks <35%.

                Loamy - Texture of fine earth is very fine sand or finer; clay <35%; rocks <35%.
                Subdivisions include coarse-loamy, fine-loamy, coarse-silty,  and fine-silty.

                Clayey - Texture of fine earth is >35% clay; rocks <35%. Subdivisions include fine
                and very fine.
Guide to Site and Soil Description              4.37

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                                        SECTION 5.0

                                    REFERENCES CITED
Alexander, M., 1982.  Most Probable Number Method for Microbial Populations in Page, A.L, R.H.
Miller, and D.R. Keeney, Eds., Methods of Soil Analysis, Part 2.  Chemical and Microbiological
Properties, 2nd Edition. American Soc. Agronomy, Madison, Wl.  pp. 815-821.

Alexander, M., 1981.  Biodegradation of Chemicals of Environmental Concern.  Science, 211:132-138.

Alexander, M., 1973.  Nonbiodegradable and Other Recalcitrant Molecules.  Biotechnology and
Bioengineering, 15:611-647.

Alexander, M., 1971.  Microbial Ecology.  John Wiley & Sons, New York, NY.  511 pp.

Allen, O.N., 1957.  Experiments in Soil Bacteriology, 3rd Ed., Revised, Burgess Publishing Co.,
Minneapolis, MN.  117 pp.

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 Publications, US EPA/CERI,
Cincinnati, OH. 221 pp. Also published  in 1989 in NWWA/EPA series by National Water Well
Association, Dublin, OH. 398 pp.

American Geological Institute, 1962.  Dictionary of Geological Terms.  National Academy of Sciences.
Dolphin Books, Doubleday and Company, Inc., New York, NY. 545 pp.

American Society for Testing and Materials, 1988a. Standard Method for Particle-Size Analysis of
Soils. 1988 Annual Book of ASTM Standards, Vol.  04.08, Designation D 422-63 (Reapproved 1972).
ASTM, Philadelphia, PA. pp. 87-93.

American Society for Testing and Materials, 1988b. Standard Practice for Description  and
Identification of Soils (Visual-Manual Procedure). 1988 Annual Book of ASTM Standards, Vol. 04.08,
Designation D 2488-84. ASTM, Philadelphia, PA. pp. 293-303.

American Society for Testing and Materials, 1988c.  Standard Test Method for Determination of Water
(Moisture) Content of Soil  by the Microwave Oven Method.  1988 Annual Book of ASTM Standards,
Vol. 04.08, Designation D 4643-87. ASTM, Philadelphia, PA. pp. 837-840.

American Society for Testing and Materials, 1988d. Standard Test Method for pH of Soil for Use in
Corrosion Testing.  1988 Annual Book of ASTM Standards, Vol. 04.08,  Designation G51-77
(Reapproved  1984).  ASTM, Philadelphia, PA. pp. 910-911.
Guide to Site and Soil Description

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                                                                                  References
American Society for Testing and Materials, 1988e. Standard Test Method for Laboratory
Determination of Water (Moisture) Content of Soil, Rock, and Soil-Aggregate Mixtures.  1988 Annual
Book of ASTM Standards, Vol. 04.08, Designation D 2216-80. ASTM, Philadelphia, PA. pp. 262-264.

American Society for Testing and Materials, 1987. Standard Method for Determining a Sorption
Constant (Koc) for an Organic Chemical in Soil and Sediments.  ASTM E1195.  ASTM, Philadelphia,
PA.

American Society for Testing and Materials, 1984. Standard Specification for Reagent Water. 1984
Annual Book of ASTM Standards.  Vol. 11.01.  Designation D 1193-77 (Reapproved 1983).  ASTM,
Philadelphia, PA.

American Society for Testing and Materials, 1981. Density of Soil and Soil Aggregate In Place by
Nuclear Methods (Shallow Depth).  ASTM D2922. ASTM, Philadelphia, PA.

American Society for Testing and Materials, 1976. Standard Practice for Oxidation-Reduction Potential
of Water. ASTM D-1498. ASTM, Philadelphia, PA.

Amoozegar, A. and A.W. Warrick, 1986. Hydraulic Conductivity of Saturated Soils: Field Methods in
Klute, A., Ed.  Methods of Soil Analysis, Part 1, Physical and Mineralogical Methods, 2nd Edition.
American Soc. of Agronomy, Madison, Wl.  pp. 735-770.

Armson, K.A., 1979.  Forest Soils, Properties and Processes.  University of Toronto Press, Toronto.
390 pp.

Atlas, R.M., 1988.  Instructors Manual. Microbial Ecology: Fundamentals and Applications,  2nd
Edition. MacMillan, New York, NY.  87 pp.

Atlas, R., and R. Bartha, eds,  1987.  Microbial  Ecology: Fundamentals and Applications. Addison-
Wesley, Reading, MA.  560 pp.

Baas Becking, L.G.M., I.R. Kaplan, and D. Moore, 1960.  Limits of the Natural Environment in Terms of
pH and Oxidation-reduction Potentials. Jour. Geol., 68:243-284.

Bache, B.W.,  1979. Soil Reaction in Fairbridge, R.W. and C.W. Finkl, Jr., eds., The Encyclopedia of
Soil Science,  Part 1. Dowden, Hutchinson & Ross, Inc., Stroudsburg, PA.  pp. 487-492.

Barber, S.A., 1984. Soil Nutrient Bioavailability, A Mechanistic Approach. John Wiley & Sons, New
York.  398 pp.

Barth, D.S., and B.J. Mason, 1984.  Soil Sampling Quality Assurance User's Guide.
EPA 600/4-84/043. U.S. Environmental Protection Agency, Environmental Monitoring  Systems
Laboratory, Las Vegas,  NV.
 Guide to Site and Soil Description               5-2

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                                                                                  References
Bartlett, R.J., 1981.  Oxidation-Reduction Status of Aerobic Soils in Stelly, M., ed., Chemistry in the Soil
Environmental, ASA Special Publication No. 40.  American Soc. Agronomy, Madison, Wl. pp. 77-102.

Barttelli, L.J., 1962.  Use of Soils Information in Urban-fringe Areas.  Journal of Soil and Water
Conservation, 17:99-103.

Bear, F.E., 1957. Toxic Elements in Soils, in Soil: The 1957 Yearbook of Agriculture.
U.S. Department of Agriculture, U.S. Government Printing Office, Washington, DC. pp. 165-171.

Bergkvist, B., 1987. Leaching of Metals in the Upper C Horizons of Spruce and Beech Forest Soils in
Lindberg, S.E., and T.C. Hutchinson, eds.  International Conference on Heavy Metals in the
Environment, Athens, Greece.  CEP Consultants, Ltd., Edinburgh, U.K. pp. 479-481.

Birkeland, P.W., 1984.  Soils and Geomorphology. Oxford University Press, New York.  372 pp.

Blake, G.R., and K.H.  Hartge, 1986.  Bulk Density in Klute, A., ed. Methods of Soil Analysis, Part 1,
Physical and Mineralogical Methods, 2nd Edition. American Soc. Agronomy, Madison, Wl.
pp. 363-375.

Blakely,  B.D., et al., 1957.  Erosion on Cultivated Land in Soil: The 1957 Yearbook of Agriculture.
U.S. Department of Agriculture, U.S. Government Printing Office, Washington, DC. pp. 290-307.

Blanchar, R.W., and C.E. Marshall, 1981. Eh and pH Measurements in Menfro and Mexico Soils in
Stelly, M., Ed.,  Chemistry in the Soil Environment, ASA Special Publication No. 40. American Soc.
Agronomy, Madison, Wl.  pp. 103-128.

Bloomfield, C.,  1981.  The Translocation of Metals in Soils in Greenland, D.J. and M.H.G. Hayes, eds.
The Chemistry of Soil Processes.  John Wiley &  Sons, New York, NY. pp. 463-504.

Boast, C.W., 1986.  Evaporation from Bare  Soil Measured with High Spatial Resolution in. Klute, A., ed.,
Methods of Soil Analysis, Part  1, 2nd Edition. Agronomy  Monograph No. 9. American Soc. Agronomy,
Madison, Wl.  pp. 889-900.

Bonnyai, Z., et al., 1988.  Method for Determining Quantity of Toxic Heavy Metals Dissolved from
Embedded Hazardous Waste in Abbou, R., ed.,  Hazardous Waste Detection, Control, Treatment, Part
A. Proceedings of the World Conference on Hazardous Waste,  Budapest, Hungary, 1987.  Elseiver,
New York, NY.  pp. 659-675.

Borror, D.J., and R.E. White, 1970.  A Field Guide to Insects, America North of Mexico.  Houghton
Mifflin Company, Boston, MA.  404 pp.

Boulding, J.R.,  1991.  Description and Sampling  of Contaminated Soils: A Field Pocket Guide.
EPA/625/12-91-002. Available from ORD Publications, US EPA/CERI, Cincinnati, OH.
Guide to Site and Soil Description               5.3

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                                                                                  References
Bouwer, H., 1986.  Intake Rate: Cylinder Infiltrometer in Klute, A., ed. Methods of Soil Analysis, Part 1,
Physical and Mineralogical Methods, 2nd Edition.  American Soc. Agronomy, Madison, Wl.
pp. 825-870.

Bouwer, H., 1979.  Conductivity, Hydraulic in Fairbridge, R.W., and C.W. Finkl, Jr., eds., The
Encyclopedia of Soil Science, Part 1.  Dowden, Hutchinson & Ross, Inc. Stroudsburg, PA.  pp. 99-
102.

Bouwer, H., 1986.  Intake Rate: Cylinder Infiltrometer in Klute, A., ed., Methods of Soil Analysis, Part 1,
2nd Edition.  Agronomy Monograph No. 9.  American Soc. Agronomy, Madison, Wl. pp. 825-844.

Bouwer, H., 1966.  Rapid Field Measurement Air Entry Value  and Hydraulic Conductivity of Soil as
Significant Parameters in Flow System Analysis. Water Resources Research, 2(4). pp. 729-738.

Brace, P., 1977, Glossary of the Environment.  Prager Publishers, New York, NY.  121 pp.

Bradford, J.M., and S.C. Gupta, 1986.  Compressibility in Klute, A., ed. Methods of Soil Analysis,
Part 1.  Physical and Mineralogical Methods, 2nd Edition.  American Soc. Agronomy, Madison, Wl.
pp. 479-492.

Breckenridge, R.P., J.R. Williams, and J.F. Keck, 1991. Characterizing Soils for Hazardous Waste
Assessment.  EPA/600/8-91/008. U.S. EPA, Office of Research and Development, Office of Solid
Waste and Emergency Response, Washington, DC.

Breton, M., et al., 1986. Treatment Technologies for Solvent  Containing Wastes, EPA/600/2-86/095.
Technical Document prepared for US EPA Hazardous Waste and Environmental Research Laboratory,
Cincinnati, OH.

Brooks, R.H.,  and AT. Corey, 1964.  Hydraulic Properties of Porous Media. Hydrology Papers No.  3.
Colorado State University, Fort Collins, CO. 30 pp.

Brown, K.W., G.B.  Evans, Jr.,  and B.D. Frentrup, eds., 1983.  Hazardous Waste Land Treatment, Rev.
ed. EPA/530/SW-874 (NTIS PB89-179014). Also published under the same title by Butterworth
Publishers, Boston.

Bruce, R.R., and R.J. Luxmore, 1986.  Water Retention: Field Methods in Klute, A., ed., Methods of
Soil Analysis,  Part 1, 2nd Edition.  Agronomy  Monograph  No. 9. American Soc. Agronomy, Madison,
Wl. pp. 663-686.

Burns, R.G., 1986.  Interaction of Enzymes With Soil Mineral  and Organic Colloids, in Huang,  P.M.,  and
M. Schnitzer,  eds., Interactions of Soil Minerals With Natural Organics and Microbes.  Soil Science
Society of America, Inc. Madison, Wl. pp. 429-451.
Guide to Site and Soil Description               5.4

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                                                                                  References
Cady, J.G., L.P. Wildung, and L.R. Drees, 1986.  Petrographic Microscope Techniques in Klute, A., ed.
Methods of Soil Analysis, Part 1, 2nd Edition.  Agronomy Monograph No. 9. American Soc.
Agronomy, Madison, Wl. pp. 185-218.

Camerlynck, R., and L. Likens, 1982. Speciation of Heavy Metals in Soils Based on Charge
Separation.  Plant and Soil, 68:331-339.

Cameron, R.E., In Press. An Expert System Field Guide for Characterization of Hazardous Waste Sites
in Proceedings of the Vlllth International Conference, Chemistry for Protection of the Environment,
Lublin, Poland, Sept. 16-19,  1991.

Cameron, R.E., et al., 1966.  Sampling and Handling of Desert Soils.  Technical  Report No. 32-908.
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA. 37 pp.

Campbell, G.S., and G.W. Gee, 1986.  Water Potential: Miscellaneous Methods in Klute, A., ed.,
Methods of Soil Analysis, Part 1, 2nd Edition.  Agronomy Monograph No. 9. American Soc.
Agronomy, Madison, Wl. pp. 619-633.

Cantzlaar, G.L, 1964.  Your Guide to the Weather.  Barnes & Noble, Inc., New York. 242 pp.

Cassell, O.K., and A. Klute, 1986.  Water Potential: Tensiometry in Klute, A., ed., Methods of Soil
Analysis, Part 1, 2nd Edition.  Agronomy Monograph No. 9.  American Soc. Agronomy, Madison, Wl.
pp. 563-596.

Chapman, H.D., 1965.  Cation Exchange Capacity jn Black, A., et al., eds., Methods of Soil Analysis,
(1sted).  American Soc. Agronomy, Madison, Wl.  pp. 891-901.

Chepil, W.S., 1957. Erosion of Soil by Wind in Soil: The 1957 Yearbook of Agriculture. U.S.
Department of Agriculture, U.S. Government Printing Office, Washington, DC.  pp. 308-320.

Clark, F.E., 1979.  Soil  Microbiology in Fairbridge, R.W., and  C.W. Finkl, Jr., eds. The Encyclopedia of
Soil Science, Part 1. Dowden, Hutchinson and Ross, Inc., Stroudsburg, PA. pp. 409-475.

Clark, F.E., 1957.  Living Organisms in the Soil in Soil: The 1957 Yearbook of Agriculture.  U.S.
Department of Agriculture, U.S. Government Printing Office, Washington, DC.  pp. 157-165.

Cloudsley-Thompson, J.L, 1988.  Evolution & Adaptation of Terrestrial Arthropods.  Springer-Verlag,
New York, NY.

Coleman, NT., and A. Mehlich,  1957. The Chemistry of Soil pH ]o Soil: The 1957 Yearbook of
Agriculture. U.S. Department of Agriculture, U.S. Government Printing Office, Washington, DC.
pp. 72-79.
Guide to Site and Soil Description              5.5

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                                                                                  References
Colwell, R.R., et al., 1987.  Detection and Enumeration of Metal Resistant Bacteria and Correlation with
Presence of Metals in the Environment tn Lindberg, S.E., and T.C. Hutchinson, eds.  International
Conference on Heavy Metals in the Environment, Athens, Greece.  CEP  Consultants, Ltd., Edinburgh,
U.K.  p. 242.

Corbitt, R.A., 1989. Standard Handbook of Environmental Engineering.  McGraw-Hill Publishing
Company, New York, NY.  1152 pp.

Corbitt, R.A., et al., 1989.  Hazardous Waste jn Standard Handbook of Environmental Engineering,
R.A. Corbitt, ed.  McGraw-Hill Publishing Company, New York, NY. pp. 9.1-9.125.

Corey, AT., 1986. Air Permeability in Klute, A., ed., Methods of Soil Analysis, Part 1, 2nd Edition.
Agronomy Monograph No. 9. American Soc. Agronomy, Madison, Wl.  pp. 1121-1136.

Coulson,  R.N.,  LJ. Folse, and O.K. Loh, 1987. Artificial Intelligence and  Natural Resource
Management.  Science, 237:262-267.

Cowherd, C., et al., 1985.  Rapid Assessment of Exposure to Paniculate Emissions from Surface
Contamination  Sites.  Prepared by Midwest Research Institute, Kansas City, MO.  NTIS PB85-192219.

Cruickshank, J.G., 1972. Soil Geography. Halsted Press Division, John Wiley & Sons, Inc., New York,
NY.

Czupyrna, G., et al., 1989. In Situ Immobilization of Heavy-Metal-Contaminated Soils. Noyes Data
Corporation, Park Ridge, NJ. 155 pp.

Danielson, R.E., and P.L Sutherland, 1986.  Porosity in Klute, A., ed., Methods of Soil Analysis, Part 1,
2nd Edition.  Agronomy Monograph No. 9. American Soc. Agronomy, Madison, Wl.  pp. 443-461.

Davis,  S.N., and R.J.M. DeWiest, 1966.  Hydrogeology.  John Wiley & Sons, New York, NY. 463 pp.

DeHaan,  F.A.M., and G.H. Bolt, 1979.  Pollution in. Fairbridge, R.W., and  C.W. Finkl, Jr., eds., The
Encyclopedia of Soil Science, Part 1. Dowden, Hutchinson & Ross, Inc., Stroudsburg, PA. pp. 386-
390.

Dixon, J.B., and S.B. Weed,  eds., 1977. Minerals in the Soil Environment, Soil Science Society of
America,  Madison, Wl.  948  pp.

Dragun, J., 1988a. The Soil Chemistry of Hazardous Materials Control.  Research Institute, Silver
Spring, MD.  458 pp.

Dragun, J., 1988b. The Fate of Hazardous Materials in Soil (What Every Geologist and Hydrogeologist
Should Know), Part 1.  Hazardous Materials Control, 1(2):30-78.
Guide to Site and Soil Description               5-6

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                                                                                   References
Dragun, J., 1988c.  The Fate of Hazardous Materials in Soil (What Every Geologist and Hydrogeologist
Should Know), Part 2. Hazardous Materials Control, 1(3):40-65.

Dragun, J., 1988d.  The Fate of Hazardous Materials in Soil (What Every Geologist and Hydrogeologist
Should Know), Part 3. Hazardous Materials Control, 1(5):24-43.

Drever, J.I., 1982. The Geochemistry of Natural Waters, Prentice-Hall, Inc., Englewood Cliffs, NJ.  388
pp.

Dunne, T., and L.B. Leopold, 1978.  Water in Environmental Planning.  W.H. Freeman, San Francisco,
CA.  818 pp.

Eastern Research Group (ERG), 1991.  Summary Report on Issues in Ecological Risk Assessment.
Prepared for U.S. EPA Risk Assessment Forum, Washington, DC.

Eisenbeis, G., and  Wichard, W., 1987.  Atlas on the Biology of Soil Arthropods.  Springer-Verlag, New
York, NY.

Everett,  L.G., LG. Wilson, and L.G. McMillion, 1982.  Vadose Zone Monitoring Concepts for Hazardous
Waste Sites. Ground Water, 20(3) :312-324.

Fairbridge, R.W., and C.W. Finkl, Jr., eds., 1979. The Encyclopedia of Soil Science,  Part 1.  Physics,
Chemistry, Biology, Fertility,  and Technology.  Dowden, Hutchinson and Ross, Inc., Stroudsburg, PA.
646 pp.

Fang, H.Y., G.M. Mikroudis, and S. Pamukcu, 1990.  Multidomain Expert System for  Hazardous Waste
Site Investigations in Hushon, J.M., ed. Expert Systems for Environmental Applications.  American
Chemical Society, Washington, DC.

Finkelstein, P.L, et  al., 1983.  Quality Assurance Handbook for Air Pollution Measurement Systems,  IV:
Meteorological Measurements.  EPA/600/4-82-060.

Finkl, C.W., Jr., 1979a. Conductivity, Electrical  in Fairbridge, R.W., and C.W. Finkl, Jr., eds., The
Encyclopedia of Soil Science, Part 1. Dowden, Hutchinson & Ross, Inc., Stroudsburg, PA.  pp. 97-98.

Finkl, C.W., Jr., 1979b. Organic Matter in  Fairbridge, R.W., and C.W. Finkl, Jr., eds., The Encyclopedia
of Soil Science,  Part 1. Dowden, Hutchinson & Ross, Inc., Stroudsburg, PA. pp. 348-349.

Finkl, C.W., Jr., 1979c. Soil Pores in Fairbridge, R.W., and C.W. Finkl, Jr., eds., The  Encyclopedia of
Soil Science, Part 1. Dowden, Hutchinson & Ross, Inc., Stroudsburg, PA.  pp. 486-487.

Fluker, B.J., 1958.  Soil Temperatures.  Soil Science, 86:35-46.
Guide to Site and Soil Description               5.7

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                                                                                   References
Ford, P.J., and P.J. Turina, 1983.  Characterization of Hazardous Waste Sites, Vol. I, Site
Investigations.  U.S. Environmental Protection Agency, Environmental Monitoring Systems Laboratory,
Las Vegas, NV.

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Idaho Falls, ID.  Vol. 2, Sect. J.,  Soil Sampling.

Roy, W.R., I.G., Krapac, S.F.J. Chou, and R.A. Griffin, 1990. Batch-Type Adsorption Procedures for
Estimating Soil Adsorption of Chemicals. Technical Resource Document EPA/530-SW-006F.

Sanchez, P.A., W. Couto, and S.W. Buol, 1982.  The Fertility Capability Soil Classification System:
Interpretation, Applicability, and Modification. Geoderma 27, pp. 283-309.

Schaller, F.,  1968.  Soil Animals. University of Michigan Press,  Ann Arbor, Ml. 145 pp.

Schmidt, E.L, and E.A. Paul, 1982.  Microscopic Methods for Soil Microorganisms in Page, A.L, R.H.
Miller, and D.R. Keeney, eds., Methods of Soil Analysis, Part 2.  Chemical and Microbiological
Properties, 2nd Edition. American Soc. Agronomy,  Madison, Wl. pp. 803-814.
Guide to Site and Soil Description              5.17

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                                                                                 References
Schmugge, T.J., T.J. Jackson, and H.L McKim, 1980.  Survey of Methods for Soil Moisture
Determination. Water Resources Research, 16(6):961-979.

Schmuller, J., 1990.  Neural Networks and Environmental Applications in Hushon, J.M., ed., Expert
Systems for Environmental Applications.  American Chemical Society, Washington, DC.

Schnitzer, M., 1982.  Organic Matter Characterization iQ Page, A.L., ed., Methods of Soil Analysis, Part
2, 2nd Edition. Agronomy Monograph No. 9.  American Soc. Agronomy, Madison, Wl.  pp. 581-594.

Schroeder,  P.R., A.C. Gibson, and M.P. Smolen, 1983. The Hydrologic  Evaluation of Landfill
Performance (HELP) Model.  EPA/DF-85-001.

Schumacker, B.A., et al., 1991. A Comparison of Soil Sample Homogenization Techniques m
Simmons, M.S., ed.  Hazardous Waste Measurements.  Lewis Publishers, Inc., Chelsea, Ml.  pp. 53-68.

Sharma, M.L, 1985.  Estimating Evapotranspiration |n Advances in Irrigation, 3. Academic Press, New
York, NY.

Shaw, A.J.,  ed., 1989.  Heavy Metal Tolerance in Plants:  Evolutionary Aspects. CRC Press, Boca
Raton, FL.  355 pp.

Shaw, R.H., 1967. Ground Level Climatology.  AAAS Publication No. 86, American Association for the
Advancement of Science, Washington, DC. 395 pp.

Shields, L.M., 1982.  Algae jn Page, A.L,  R.H. Miller, and D.R. Keeney, eds., Methods of Soil Analysis,
Part 2. Chemical and Microbiological Properties, 2nd Edition.  American Soc. Agronomy,  Madison, Wl.
pp. 1093-1101.

Shtina, E.A., and  M.M.  Hollerbach, 1979.  Algae in Fairbridge, R.W., and C.W. Finkl, Jr., eds., The
Encyclopedia of Soil Science, Part 1.  Dowden,  Hutchinson & Ross, Inc. Stroudsburg, PA. pp. 29-36.

Shuckrow, A.J., A.P. Pajak, and C.J. Touhill, 1980.  Management of Hazardous Waste Leachate.  U.S.
EPA, Municipal Research Laboratory, Office of Research and Development, Cincinnati, OH
SW-871.

Silver, M., H.L Ehrlich, and K.C. Ivarson,  1986.  Soil Mineral Transformation Mediated by Soil
Microbes, in Huang, P.M., and  M. Schnitzer, eds., Interactions of Soil Minerals with Natural Organics
and Microbes. Soil Science  Society of America, Inc., Madison, Wl.  pp. 497-519.

Simmons, M.S., ed., 1991. Hazardous Waste Measurements.  Lewis Publishers, Chelsea, Ml.
315 pp.
Guide to Site and Soil Description              $--\Q

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                                                                                  References
Sims, R.C., et al., 1988. Soil Transport and Fate Database. R.S. Kerr Environmental Research
Laboratory, U.S. EPA, Office of Research and Development, Ada, OK.

Sims, R., et al., 1986. Contaminated Surface Soils. In-place Treatment Techniques.  Noyes
Publications, Park Ridge, NJ.  536 pp.

Smith, G.D., F. Newhall, and LH. Robinson, 1960.  Soil-Temperature Regimes-Their Characterization
and Predictability. SCS-TP-144.  USDA Soil Conservation Service.  14pp.

Smith, K.A., and J.R.M. Arah, 1991.  Gas Chromatographic Analysis of Soil Atmosphere in Smith, K.A.,
ed., Soil Analysis: Modern Instrumental Techniques, 2nd Edition. Marcel Dekker, New York, NY.  pp.
505-546. [First edition published  1983.]

Soil Science Society of America, 1987. Glossary of Soil Science Terms.  Soil Science Society of
America, Madison, Wl. 44 pp.

Soon, Y.K., ed., 1985.  Soil Nutrient Availability. Chemistry and Concepts. Van Nostrand Reinhold
Co., NY.  353 pp.

Stephens, J.C., and E.H. Stewart, 1964.  A Comparison of Procedures for Computing Evaporation and
Evapotranspiration. Agricultural Research Service, Ft. Lauderdale, FL.

Stern, K.R., 1988.  Introductory Plant Biology, 4th Edition. William C. Brown  Publishers, Dubuque, IA.

Stotzky, G., 1986. Influence of Soil Mineral Colloids on Metabolic Processes, Growth, Adhesion, and
Ecology of Microbes and Viruses, jn Huang, P.M. and M. Schnitzer, eds., Interactions of Soil Minerals
with Natural Organics and Microbes. Soil Science Society of America, Inc., Madison, Wl.  pp.  305-428.

Stout, J.D., S.S. Bamforth, and J.D. Lousier, 1982.  Protozoa in Page, A.L, R.H. Miller,  and D.R.
Keeney, eds., Methods of Soil Analysis, Part 2.  Chemical and Microbiological Properties, 2nd  Edition.
American Soc. Agronomy, Madison, Wl. pp. 1103-1118.

Stumm,  W., and J.J. Morgan, 1981.  Aquatic Chemistry, 2nd Edition.  Wiley Interscience, New  York,
NY. 780 pp.

Stupar, J., et al., 1991. Transformation and Mobility of Chromium in Soil-Plant System. Annual Report
JF 908 (EPA).  University of Ljubljana, Slovenia.  30 pp. +3 Append.

Tabatabai, M.A., 1982. Soil Enzymes in Page, A.L, R.H. Miller, and D.R. Keeney, eds., Methods of Soil
Analysis, Part 2.  Chemical and Microbiological Properties, 2nd Edition. American Soc. Agronomy,
Madison, Wl.  pp. 903-944.
Guide to Site and Soil Description              5-19

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                                                                                  References
Talibudeen, O., 1981. Cation Exchange in Soils in Greenland, D.J., and M.H.G. Hayes, eds., The
Chemistry of Soil Processes.  John Wiley & Sons. New York, NY.  pp. 115-177.

Talsma, T., 1960.  Comparison of Field Methods Measuring Hydraulic Conductivity.  International
Committee, Irrigation and Drainage, 4th Congress, Madrid, Spain,  pp. 145-156.

Taylor, S.A., and R.D. Jackson, 1986. Temperature in Klute, A., ed., Methods of Soil Analysis, Part 1,
Physical and Mineralogical Methods, 2nd Edition.  American Soc. Agronomy, Madison, Wl.
pp. 927-940.

Thomas, G.W., 1982.  Exchangeable Cations in Page, A.L, et al., eds., Methods of Soil Analysis, Part
2, 2nd Edition. Agronomy Monograph No. 9. American Soc. Agronomy, Madison, Wl. pp. 159-165.

Thompson, et al., 1989. Techniques to Develop Data for Hydrogeochemical  Models.  EPRI EN-6637.
Electric Power Research Institute, Palo Alto, CA. 371 pp.

Thompson, L.M., and F.R. Troeh, 1978.  Soil and Soil Fertility, 4th Edition.  McGraw-Hill Book Co.,
Navato, CA.  516 pp.

Thornthwaite, C.W., and J.R. Mather, 1957. Instructions and Tables for Computing Potential
Evapotranspiration and Water Balance.  Publications in  Climatology, Vol. 10,  No. 3, Drexel Institute of
Technology,  Laboratory of Climatology,  Centerton, NJ.

Tisdale, S.L, and W.L Nelson, 1975.  Soil Fertility and Fertilizers, 3rd Edition. MacMillian Publishing
Co., Inc., New York, NY.

Trewetha,  G.T., and LH. Horn, 1980.  An Introduction to Climate. McGraw-Hill Book Co., Inc., New
York, NY.  416pp.

USDA Forest Service, 1963.  Handbook of Soils, Amendment No. 1. Physical Properties of Soils. U.S.
Department of Agriculture, Forest Service, U.S. Government Printing Office, Washington, DC.

USDA Forest Service, 1961.  Handbook of Soils. U.S. Department of Agriculture, Forest Service, U.S.
Government Printing Office, Washington, DC.

USDA Soil Conservation Service, 1990.  Elementary Soil Engineering m Engineering Field Manual for
Conservation Practices. SCS, Washington, DC. Chapter 4.

USDA Soil Conservation Service, 1987.  Soil Description.  U.S. Department of Agriculture,
SCS-S01-232. 4pp.
Guide to Site and Soil Description              5.20

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                                                                                 References
USDA Soil Conservation Service, 1984.  Soil Survey Laboratory Methods and Procedures for Collecting
Soil Samples. Soil Survey Investigations Report No. 1.  U.S. Government Printing Office,
Washington, DC.

USDA Soil Conservation Service, 1983.  National Soils Handbook. U.S. Department of Agriculture,
U.S. Government Printing Office, Washington, DC.  619  pp.

USDA Soil Conservation Service, 1981.  Soil Survey Manual. U.S. Department of Agriculture, 430-V-
SSM.  Chapters 1-12.

USDA Soil Conservation Service, 1979.  Pedon Coding System for the National Cooperative Soil
Survey.  U.S. Department of Agriculture, Soil Conservation Service, Washington, DC.

USDA Soil Conservation Service, 1975.  Surface Runoff  in Engineering Field Manual for Conservation
Practices.  SCS, Washington, DC. Chapter 2.

USDA Soil Conservation Service, 1971.  Handbook of Soil Survey Investigation Procedures.  90 pp.

USDA Soil Conservation Service, 1970.  Soils in the Soil Conservation Service. U.S. Department of
Agriculture, Portland, OR.

USDA Soil Survey Staff, 1991.  Examination and Description of Soil in Soil Survey Manual (new
edition). Agricultural Handbook No.  18.  Soil Conservation Service, Washington,  DC. Chapter 3.

USDA Soil Survey Staff, 1990.  Keys  to Soil Taxonomy, 4th Edition. SMSS Technical Monograph
No. 19.  Dept. Crop and Soil Environment Sciences, Virginia Tech, Blacksburg, VA, 24061-0404,
422 pp.

USDA 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.
Washington, DC.

USDA Soil Survey Staff, 1960.  Soil Classification:  A Comprehensive System. 7th Approximation.
U.S. Department of Agriculture, Soil Conservation Service, U.S. Government Printing Office,
Washington, D.C.

US DOE, 1987.  Environmental Survey Manual.  Office of Environmental Audit and Compliance,
Washington, DC.

US EPA, 1991 a. Bulk Density in Forest Health Monitoring/Environmental Monitoring and Assessment
Program: Soil and Foliar Preparation Laboratory Standard Operating Procedures (in preparation)
EMSL.  Las Vegas, NV.  Part II, Sect. 6, 12 pp.
Guide to Site and Soil Description             5.21

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                                                                                References
US EPA, 1991b. Cation Exchange Capacity jn Forest Health Monitoring/Environmental Monitoring and
Assessment Program: Soil and Foliar Preparation Laboratory Standard Operating Procedures (in
preparation) EMSL  Las Vegas, NV.  Part II, Sect. 7, 27 pp.

US EPA, 1990a. Handbook on In Situ Treatment of Hazardous Waste-Contaminated Soils.
EPA/540/2-90/002. U.S. EPA,  Risk Reduction Engineering Laboratory, Cincinnati, OH.

US EPA, 1990b. Assessing the Geochemical Fate of Deep-Well-Injected Hazardous Waste: A
Reference Guide. EPA/625/6-89/025a.  Available from  CERI, Cincinnati, OH.

US EPA, 1989a. Determining Soil Response Action Levels Based on Potential Contaminant Migration
to Ground Water: A Compendium of Examples. EPA/540/2-89/057.

US EPA, 1989b. Bioremediation of Hazardous Waste Sites Workshop: Speaker Slide Copies and
Supporting Information. U.S. EPA, Office of Research and Development, Washington, DC 20460.

US EPA, 1989c. Glossary of Environmental Terms and Acronym List. 19K-1002. Office of
Communication and Public Affairs (A-107). Washington, DC.

US EPA, 1989d. Guide for Conducting Treatability Studies Under CERCLA.  EPA 540/2-89/058. (NTIS
PB90-299772).

US EPA, 1989e. Seminar On Site Characterization for  Subsurface Remediation. CERI-89-224. U.S.
EPA, Office of Research and Development, Washington, DC  20460.

US EPA, 1988a. Sampling for Hazardous Materials,  U.S. Environmental Protection Agency, Office of
Emergency and Remedial Response, Washington, DC.

US EPA, 1988b. Field Screening Methods for Hazardous Waste Site Investigations, Proceedings of
the First International Symposium, October 11-13, 1988.

US EPA, 1988c. Field Screening Methods Catalog: User's Guide. EPA/540/2-88/005.  FSMC System
Coordinator, OERR, Analytical Operations Branch (WH-548-A), U.S. EPA, Washington, DC 20460.

US EPA, 1988d. Guidance for Conducting Remedial Investigations, and Feasibility Studies Under
CERCLA: Interim Final.  EPA/540/G-89/004.  OERR, U.S. EPA, Washington, DC 20460.

US EPA, 1988e. Superfund Exposure Assessment Manual.  EPA/540/1-88/001, OSWER Directive
9285.5-1 (NTIS PB90-135859).

US EPA, 1988f. Technology Screening Guide for Treatment of CERCLA Soils and Sludges.
EPA/540/2-88/004, (NTIS PB89-132674.) U.S. EPA, Washington, DC 20460.
Guide to Site and Soil Description             5-22

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                                                                                References
US EPA, 1987a. A Compendium of Superfund Field Operations Methods, Office of Emergency and
Remedial Response, Office of Waste Programs Enforcement. EPA/540/P-87/001.  OSWER Directive
9355.01-4 (NTIS PB-88-181577).

US EPA, 1987b. Data Quality Objectives for Remedial Response Activities.  Example Scenario: RI/FS
Activities at a Site with Contaminated Soils and Ground Water.  EPA-540/G-87/004.

US EPA, 1987C. Data Quality Objectives for Remedial Response Activities.  Development Process.
EPA-540/G-87/003.

US EPA, 1986a. Guidance Document for Cleanup of Surface Impoundment Sites, Office of Solid
Waste and Emergency Response, OSWER Directive 9380.0-6. Washington, DC.

US EPA, 1986b. Accepted Updates, 1989 and 1990. Test Methods for Evaluating Solid Waste: Vol. 1,
Sect. C, Laboratory Manual, Physical/Chemical Methods, 3rd ed.,  Office of Solid Waste and
Emergency Response, SW 846. Washington, D.C.

US EPA, 1983. Characterization of Hazardous Waste Sites, A Methods Manual:  Vol II.  Available
Sampling Methods. EPA-600/4-83/040.

US EPA, 1979. Methods for Chemical Analysis of Water and Wastes.  EPA-600/4-79-020.
Environmental Monitoring and Support Laboratory. Cincinnati, OH.

US EPA, 1978. National Enforcement Investigations Center (NEIC) Policies and Procedures.
EPA-330/9-78-001-R.

US Geological Survey, 1977.  National Handbook of Recommended Methods for Water Data
Acquisition  (Chapter 8--Evaporation and Transpiration, updated June 1982).  USGS Office of Water
DATA Coordination, Reston, VA.

van Bavel, C.H.M., 1963.  Soil Moisture Measurement with the Neutron Method. USDA-ARS, ARS-41-
70, U.S. Government Printing Office, Washington, DC.

van Ee, J.J., 1991. Assess User's Guide,  Version 1.0. EPA/600/8-91/001.  EMSL.  Las Vegas, NV.

van Ee, J.J., LJ. Blume,  and T.H. Starks, 1990. A  Rationale for the Assessment of Errors in the
Sampling of Soils.  EPA/600/4-90/013. EMSL.  Las Vegas, NV.

van Genuchten, M.Th. In press. Proceedings of the International Workshop on Indirect Methods for
Estimating the Hydraulic Properties of Unsaturated Soils, Riverside, CA, October 11-13, 1989.  Univ. of
CA-Riverside and U.S. Department of Agriculture.
Guide to Site and Soil Description             5-23

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                                                                                  References
van Genuchten, M.Th., 1980.  A Closed Form Equation for Predicting the Hydraulic Conductivity of
Unsaturated Soils.  Soil Sci. Soc. Am. J., 44:892-898.

van Genuchten, M.Th., and P.J. Wierenga,  1986.  Solute Dispersion Coefficients and Retardation
Factors in Klute, A., ed., Methods of Soil Analysis, Part 1, 2nd Edition. Agronomy Monograph No. 9.
American Soc. Agronomy, Madison, Wl.  pp. 1025-1054.

Veihmeyer,  F.J., 1964.  Evapotranspiration  in Chow, V.T., ed., Handbook of Applied Hydrology.
McGraw-Hill, New York, NY.  pp. 11-1 to 11-38.

Vinogradov, A.P., 1959. The Geochemistry of Rare and Dispersed Chemical Elements in Soil, 2nd
Edition, Revised. Consultants Bureau, Inc., New York, NY. 209 pp.

Vogel, W.G., 1987.  A Manual for Training Reclamation Inspectors in the Fundamentals of Soils  and
Revegetation.  Soil and Water Conservation Society, Ankeny, IA. 178 pp.

Wagenet, R.J., 1986.  Water and Solute Flux in Klute, A., ed., Methods of Soil Analysis, Part 1, 2nd
Edition.  Agronomy Monograph No. 9. American Soc. Agronomy, Madison, Wl.  pp. 1055-1088.

Walker, B.,  1983. A Glossary of Agricultural Terms Relating to Soil and Water.  Merlin Books, Ltd.,
Braunton, Great Britain. 203 pp.

Wallwork, J.A., 1976.  The Distribution and  Diversity of Soil Fauna.  Academic Press, London. 355 pp.

Wallwork, J.A., 1970.  Ecology of Soil Animals. McGraw-Hill,  New York, NY.  283 pp.

Weier, T., et al., 1982.  Botany: An  Introduction to Plant Biology, 6th Edition.  John Wiley &  Sons,
New York, NY.

Whittig, L.D., and W.R. Allardice, 1986.  X-Ray Diffraction Techniques in Klute, A., ed., Methods of Soil
Analysis,  Part 1, 2nd Edition.  Agronomy Monograph No. 9. American Soc. Agronomy, Madison, Wl.
pp. 331-362.

Williams, ST., and E.M.H. Wellington, 1982. Actinomycetes in Page, A.L., R.H.  Miller, and D.R.
Keeney, eds., Methods of Soil Analysis, Part 2.  Chemical and Microbiological Properties, 2nd Edition.
American Soc. Agronomy, Madison, Wl.  pp. 969-986.

Wilson, L.G., 1982.  Monitoring in the Vadose Zone, Part II.  Ground Water Monitoring Review, 2(4):31-
42.

Wilson, L.G., 1981.  Monitoring in the Vadose Zone, Part I: Storage Changes. Ground Water
Monitoring  Review,  1(3):32-41.
Guide to Site and Soil Description              5.24

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                                                                                  References


Wischmeir, W.H., and D.D. Smith, 1978.  Predicting Rainfall Erosion Losses-A Guide to Conservation
Planning.  U.S. Department of Agriculture Handbook No. 537, U.S. Department of Agriculture, U.S.
Government Printing Office, Washington, DC.  58 pp.

Wollum II,  A.G., 1982.  Cultural Methods for Soil Microorganisms in Page, A.L, R.H. Miller, and D.R.
Keeney, eds., Methods of Soil Analysis, Part 2. Chemical and Microbiological Properties, 2nd Edition.
American Soc. Agronomy, Madison, Wl.  pp. 781-802.

Woodruff,  N.P., and F.H.  Siddoway, 1965.  A Wind Erosion Equation.  Soil Sci. Soc. Am. Proc., 29:602-
608.

Woolley, T.A., 1982.  Mites and Other Soil Microarthropods in Page, A.L., R.H. Miller, and D.R. Keeney,
eds., Methods of Soil Analysis, Part 2. Chemical and Microbiological Properties, 2nd Edition.
American Soc. Agronomy, Madison, Wl.  pp. 1131-1142.

Zachmann, D.W., P.C.  DuChateau, and A. Klute, 1982.  Simultaneous Approximation of Water Capacity
and Soil Conductivity by  Parameter Identification. Soil Science, 134:157-163.
Guide to Site and Soil Description              5.25

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                                         APPENDIX A

                        SOURCES OF SITE CHARACTERIZATION DATA
Any soil sampling effort at a hazardous waste site requires knowledge of the site. Too often, however,
not enough time is spent in determining the historical data sources (and resources) and obtaining the
preliminary information and data necessary to adequately plan and undertake a reliable soil sampling
effort.

A thorough investigation of available data and information, followed by data review and evaluation,
should be conducted as early as possible in the project and prior to soil sampling.  By reviewing
historical site information, conducting site visits, interviewing area residents and knowledgeable
personnel at facilities,  agencies, and other organizations, a good grasp of the site and situation can
be obtained for sampling purposes.  Procurement and review of this available background information
is a logical and essential first step in planning the site activities, and can often assist in the selection
of analytical methods and in the preparation of reports.

Initially, the researcher should look for information that provides an overview of the site relationship tc
the regional setting and the pollutant problem.  It is important to look at the data in the context of lh3
soil ecosystem at the site, relative to potential sampling activities. The historical data should help
answer questions about the sources of pollution, routes of migration, and uses of the site and  arpi
The types of data will vary with the site, but, in general, should deal with the history of site an^    i
use;  surface and subsurface characteristics; historical drainage patterns; soil types; root and vadose
zone characteristics; ground-water drainage pattern, flow, and use; and the environmental and health
problems associated with safety hazards.

Some typical  sources  and types of data useful in a systematic assessment of waste disposal sites are
shown in the  table below.

            Type of Data                                     Typical Sources

Property Survey                            County  Records, Property Owner; various County/City
                                           Planning/Zoning Commission Departments

Well  Driller's Logs                           Well Driller, Property Owner, State Records

Water Level Measurements                  Well Owner's Observations, Well Driller's Logs,
                                           Topographic Maps, Ground Water Maps (Reports)

Topographic  Maps                          U.S. Geological Survey and Designated State Sales
                                           Offices
Guide to Site and Soil Description              A-1

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                                                                                  Appendix A
            Type of Data
Air Photos
County Road Maps

Ground-Water Reports

Soil Surveys of Counties/
Parishes (Louisiana)

Geologic Maps

Climatological Data

RCRA permits and
Applications

Local History, Reports,
Information

Local Soils, Geology,
Water Levels, Regulations

Reference Data and Bibliographies

Process, Hazards,
Protective  Equipment Needs

Liquid waste types
Production Information,
Treatment Processes

Location of buried lines
                  Typical Sources
 U.S. Geological Survey, U.S. Department of
Agriculture, U.S. Forest Service, Companies
Contracted by County and City Governments

State Agencies

U.S. Geological Survey, State Agencies

U.S. Department of Agriculture


U.S. Geological Survey and State Surveys

National Oceanic and Atmospheric Administration

U.S. EPA and State Environmental Offices


City Offices


Contractors


Computer Data Bases

U.S. Department of Labor
Occupational Safety and Health Administration (OSHA)

National Pollution Discharge
Information System (NPDS)
Utility Companies:  Gas, Electric, Water,
Petroleum, or Natural Gas Pipelines
These sources can provide useful information for developing, planning, and implementing soil
sampling procedures, guidelines, and protocol for a particular site. Available data may include
previous environmental studies, on-site inspections, and facility operations and disposal practices.
Site descriptive information may be available on terrain, topography, physiography, soils/geology,
Guide to Site and Soil Description
  A-2

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                                                                                   Appendix A
ecology, biota, climate/weather, surface and ground water, contaminant characterization, and sensitive
receptors.

Sampling and sample handling are crucial elements for any subsequent examination and analysis of
soil samples obtained in the field.  Some analyses can only be performed in the laboratory; therefore,
soil samples must be procured for this purpose.  Special care must be taken in sampling, handing
and storage for some analyses, e.g. microbiota.  Sampling equipment procedures and methods are
not included in this document.  They are included in the ESES document and should be referred  to
for that purpose. Additional information is provided in Boulding (1991), A Field Pocket Guide.  The
following references, which  include those for sampling soils contaminated with hazardous wastes, may
be useful.
       Barth, D.S., and B.J. Mason, 1984
       Cameron, R.E., et al., 1966, 37 pp.
       Coleman, NT., and A. Mehlich, 1957
       Fuentes, A., and M.S. Simmons, 1991, pp. 17-33
       Gardner, E.H., 1977, 6 pp.
       Lewis, T.E., et al., 1991
       Mason,  B.J., 1983a and 1983b
       Peck, T.R., and S.W. Melsted, 1973
       Peterson, R.G., and LD. Calvin, 1986, pp. 33-51
       Raab, G.A., et al., 1991, pp 35-51
       Rope, R., R. Breckenridge, et al.,  Sec. J,  1990
       Schumacher, B.A., et al., 1991, pp. 53-68
       USDA Soil Conservation Service,  1984
       US EPA, 1986b

For soil sampling information, particular attention should be given to the Soil Conservation Service
(SCS) and Soil Survey staff, along with the Agricultural Stabilization and Conservation Service, and
state and county cooperative extension services. All of these agencies have frequent and continued
contact with the local community and are often informed about rural areas.  They should have a
knowledge of the soil ecosystem, local soils, and its responses (e.g., flooding, use, and movement).
They are usually qualified to assist in obtaining the kinds of information needed in regard to history of
the area and the presence and effects  of pollution.  They are also valuable sources for identifying local
historians:  local citizens and authorities such as fire,  police, health, engineering, highway and
maintenance departments, tax and legal departments and officers, forestry and conservation workers,
and wildlife biologists. Information also may be gathered from these sources about prior land use.
The local fire department can often provide information on the nature and movement of spilled
materials, which is especially important for any countermeasures taken on unusually toxic materials.
Other City offices, such as the Chamber of Commerce, can provide information about local industries,
principal products and facility addresses.
Guide to Site and Soil Description               A-3

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                                                                                   Appendix A
Most states have an agricultural college that is closely aligned with the U.S. Department of Agriculture.
The Soils and Agronomy departments of the Land Grant universities often work closely with the SCS
and extension services, and are involved in agricultural soils analyses. Their files often contain
valuable information on the nature of soils in an area, and they may know about past and present
problems, including soil  pollution, and any remedial measures taken.

The U.S. Geological Survey (USGS)  is another valuable source of information for technical geological
and hydrologic reports, maps, aerial photographs, and water monitoring data. Frequently, the
geologist working on a vadose or ground-water problem, surficial or bedrock geological mapping, will
have information on soil  properties and pollutant migration.  The  well driller's log books, which are
kept when exploratory borings are made for highway or building  construction, can augment the data
collected by soil investigators.  The USGS, along with the Corps  of Engineers and Bureau of
Reclamation, maintains information on flooding, stream conditions, and stream flow, which is important
in determining the rate and route of  pollution migration.

EPA, or one of its state counterparts, should always be consulted, particularly to determine if pollution
at the site is being investigated, and if there are analyses and other data that should be reviewed
before sampling at the site. The EPA and State Environmental Office will have information on RCRA
permits and applications.  In addition, state environmental, resource, and health agencies should be
consulted.  Useful data may be archived at their offices.

Environmental Impact Statements (EISs)  are particularly valuable, providing information on soils
properties and land use. A review of EISs can aid planning and  thereby decrease the cost of the
proposed study, as well  as enhance the  effectiveness of the soil  sampling plan.

Aerial photographs and  remote sensing imagery obtained by aircraft or satellite can be valuable in
determining the impacts of pollutants and in identifying routes and effects of migration.  One of the
best historical records available of old landfill sites is the archived aerial photographs. Remote
sensing imagery can also provide information on drainage patterns, land use, vegetation stress,
historical land development, and geologic structure.

EMSL-LV is one of the best resources available for pollution-oriented imagery and photographs.
Taken in conjunction with accidents  or chemical spills, these photographs are a valuable resource for
determining where samples should be taken on H*e site.  If necessary, current photography is
obtained from overflights, as part of  a preliminary assessment. The following sources can often
provide information on available imagery.

       Agricultural Stabilization and Conservation Service
       Bureau of Reclamation
       Colorado River Commission
       EROS Data Center
       National Aeronautics and Space  Administration
       National Archives and Record Service
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                                                                                   Appendix A
       National Oceanic and Atmospheric Administration
       National Park Service
       National Weather Service
       Tennessee Valley Authority
       U.S. Air Force
       U.S. Army Corps of Engineers
       U.S. Army Map Service
       U.S. Coast and Geodetic Survey
       U.S. Commodity  Stabilization Service
       U.S. Forest Service
       U.S. Geological Survey
       U.S. Department of Agriculture, Soil Conservation Service
Sources of data obtained should be properly documented to ensure later confirmation that the data
are of a quality and reliability appropriate to their intended use.
Guide to Site and Soil Description              A-5

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                                        APPENDIX B

                GENERAL DEFINITIONS: SITE AND SOIL CHARACTERIZATION
This appendix provides definitions and terminology for characterizing the place, scene or point of
study and examination of the environment containing wastes and contaminants; the spatial location
and extent of surface and subsurface features; and also temporal description during the period of
study. Also, see Section 5, References Cited, for sources used for general directions.

ABANDONED HAZARDOUS WASTE SITE - See uncontrolled hazardous waste disposal site.

ABSORPTION - (i) In biology, the net movement (transport) of water and solutes from outside a cell or
an organism to the interior, (ii) In chemistry, the taking up of matter in bulk by other matter, as in
dissolving of a gas or liquid, e.g., within the lattice structure of soil clay particles.

ACID-BASE REACTION - (i) The reaction of the solvent cation with the solvent anion; (ii) A chemical
reaction involving a base and an acid, e.g., in a soil solution or on a clay particle upon addition of an
acidic or basic substance.

ACID CLAY - A clay that gives off hydrogen ions when  it dissolves in water.

ACID SOIL - Soil with a pH value < 7.0. An extremely acid soil is pH value < 4.5. A slightly acid soil is
pH  value 6.1 to 6.5. See soil reaction.

ACTINOMYCETES - A group of microorganisms usually possessing very fine hyphae or threads,
classified with bacteria or fungi. Various kinds cause decomposition, cause disease,  or produce
antibiotics. See microflora.

ACUTELY HAZARDOUS WASTE - Commercial chemical products and manufacturing intermediates
having the generic names listed in  40 CFR 261.33; off-specification  commercial chemical products and
manufacturing chemical intermediates which, if they met specifications, would have the generic names
listed; and any residue or contaminated soil, water, or other debris resulting from the cleanup of a spill
of any of these substances.

ADSORPTION - The process by which atoms, molecules or ions are taken up and retained on the
surface of solids by chemical or physical binding, e.g., the adsorption of cations by negative charged
minerals.

AERATED SOIL - A soil that allows or promotes exchange of soil gases with atmospheric gases. The
rate of aeration depends largely on the volume  and continuity of air-filled pores within the soil.
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                                                                                  Appendix B
AERATION POND - A fluid-holding pond with provisions to aerate its contents by bubbling air or
another gas through the liquid or by spraying the liquid into the air. See hazardous waste surface
impoundment.

AEROBIC - (i) Having molecular oxygen as a part of the environment, (ii) Growing only in the
presence of molecular oxygen, as aerobic organisms,  (iii) Occurring only in the presence of molecular
oxygen (said of certain chemical or biochemical processes such as aerobic decomposition).

AESTHETICS - Individual perceptions of any activity or situation indicating a change in the quality or a
distinguishable characteristic of the perceived environment. (Perceived through the senses: sight,
taste, smell, hearing, and touch.)  Can be quantified or semiquantified by instrumental means,
including photography.

AGGREGATE - A unit of soil structure, usually formed by natural processes in contrast with artificial
processes, and generally <  10 mm in diameter.

AGRICULTURAL POLLUTION - The liquid and solid wastes from farming, including runoff and
leaching of pesticides and fertilizers; erosion  and dust from plowing; animal manure and carcasses;
and crop residues and debris.

AGRICULTURAL SOILS - Soils that are cultivated to produce food or fiber, and for the raising of
livestock.  Can include forests and rangeland soils.

AGROHYDROLOGY - The science dealing with the  distribution and movement of water and soil
solution to and from the saturated root zone  (in agricultural lands).

AGRONOMY - The branch of agriculture dealing with field crop production and soil management.

AIRBORNE SURVEY - An aerial survey, remote sensing, or other photographic means used to obtain
site characteristics, e.g., nature, distribution and "health" of vegetation. See ground data.

AIR DRY SOIL - The state of dryness of a soil which is at equilibrium with the moisture (water) content
of the surrounding atmosphere.

ALGAE - Simple rootless plants that grow in sunlit waters in relative proportion to the amounts of
nutrients available. They can affect water quality adversely by lowering the dissolved oxygen in the
water. They are food for fish and small aquatic animals.

ALKALI METALS - Elements  (Group I) that are highly basic, i.e., lithium, sodium, potassium, rubidium,
cesium and francium. The alkali metals react  very readily, are the most electropositive of all the metals,
always form ionic compounds (except for lithium in rare instances) and have only one oxidation state,
+ 1. Compare with alkaline earth metals.
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                                                                                Appendix B
ALKALINE EARTH METALS - Elements (Group II) that have noble gas cores and two electrons in the
valence shells of their atoms. They exhibit only one oxidation state, +2. Elements include beryllium,
magnesium, calcium, strontium and barium. With the exception of beryllium, these elements almost
exclusively form ionic compounds. Compare with alkali metals.

ALKALINE SOIL - Any soil having a pH > 7.0 or > 7.3; strongly alkaline, pH > 9.0. See soil reaction.

ALLOCHTHONOUS MATERIALS - Materials formed, produced or occurring elsewhere than in place;
of foreign origin or introduced.

ALLOCHTHONOUS MICROBIOTA - Microorganisms that are not indigenous to the soil, but that enter
in precipitation, diseased tissues, manure, sewage, wastes, etc. They may persist for some time but
do not contribute in a significant way to ecologically significant transformations or interactions.

ALLOTROPES - Different forms of the same element in the same state, e.g., arsenic and antimony,
have stable metallic forms and less stable nonmetallic allotropes.

ALLOY - An intimate mixture of two or more metals or metals plus nonmetals in a substance that has
metallic properties.

ALLUVIAL SOILS - Soils developed from recently deposited alluvium and showing little or no profile
development.

ALLUVIUM - Sediments deposited by running water or streams and rivers. It may occur on terraces
well above present streams or in the normally flooded bottom land of existing streams.

ALTERED PEDOLOGICAL FEATURES - Recognizable or distinct pedological units which differ from
the undisturbed features, such as by the addition of chemical contaminants. See pedological features.

AMENDMENT - Any material such as lime or synthetic conditioners that is worked into the soil to
make it more productive (usually materials other than fertilizers).

AMPHOTERISM - The ability to act as either an acid or base.

ANAEROBIC -  (i) The absence of molecular oxygen,  (ii) Growing in the absence of molecular oxygen
(such as anaerobic bacteria), (iii) Occurring in the absence of molecular oxygen (as a biochemical
process).

ANALYTICAL PARAMETERS, Superfund - Constituents and levels of detection, usually chemical,
required for sample analysis. Parameters also include field measurements (e.g., soil permeability,
particle size analysis), and Contract Laboratory Program (CLP) Special Analytical Services (SAS)
components. See Contract Laboratory Program.
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                                                                                 Appendix B
ANION EXCHANGE CAPACITY - The total exchangeable anions (non-metallic ions, acid radicals and
hydroxyl ions) that a soil can absorb, expressed in milliequivalents per 100 grams or per gram of soil.
See ion exchange.

ANISOTROPIC - A condition of a medium whose physical properties vary in different directions. See
anisotropic soil. Antonym, isotropic.

ANISOTROPIC SOIL - A soil with hydraulic conductivity in different directions. Compare with isotropic
soil.

AQUATIC PLANTS - Vegetation whose growth medium is primarily water, although they may be
rooted in soil. They include primarily free-floating plants, all surface and submerged rooted plants,
swamp and marsh vegetation having roots periodically or primarily submerged in water.

AQUIFER - An underground geological formation, or group of formations, containing usable amounts
of ground water that can supply wells and springs; a body of rock or soil sufficiently permeable to
conduct ground water and to yield significant quantities of water to wells or springs.

AREA - A general, wide term used for any portion of the earth's surface. It includes  positional location
and the environmental content, e.g., site area. See site.

ARGILLACEOUS -  Rocks or sediments largely composed of clay minerals or clay-sized particles.

ARTHROPOD - Invertebrate animals, such as insects, arachnids, and crustaceans, that have a jointed
body and limbs; any of the phylum Arthropoda. See microfauna.

ATTENUATION - The process by which a compound is reduced in concentration over time, through
absorption, degradation, dilution, and/or transformation.

ATTERBERG LIMITS - The collective designation of seven so-called limits of consistency of fine-
grained soils. See consistency.

AVAILABLE WATER - The portion of water in a soil that can be absorbed by plant roots.  It is the
amount of water released between in situ field capacity and the permanent wilting point.

BACKGROUND SOIL PROPERTY - The property or characteristic of a soil prior to the addition of
substances or materials that alters its natural (indigenous) state or conditions.

BACTERIA - (Singular: bacterium) Microscopic living organisms which can aid in pollution control by
consuming or breaking down organic matter in sewage or by similarly acting on oil spills  or other
water pollutants. Bacteria in soil, water or air can also cause human, animal and plant health
problems.
Guide to Site and Soil Description              B-4

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                                                                                Appendix B
BAROMETRIC PRESSURE - Atmospheric pressure measured with a mercury or anaeroid (no fluid)
barometer.

BAROTAXIS - Response by locomotion of an organism (or part) in response to barometric stimulus.

BASAL AREA - (i) The area of the cross section of a tree at height 1.4 m above the ground, usually
expressed as the summation of the  basal area of the trees in a forest in square meters per hectare, (ii)
The surface of the soil actually covered or occupied by a plant, especially the basal part, as compared
to the full spread of the herbage; in grassland ecology often measured at 2 cm above the ground
surface. See ground cover.

BASALT - See granular rock structure.

BASE - A substance that in aqueous solution increases the hydroxide ion concentration.

BASE CATIONS - Soil exchangeable cations: calcium, magnesium, potassium and sodium.

BASE SATURATION - The relative degree to which soils have metallic cations absorbed. The
proportion of the cation-exchange capacity that is saturated with metallic cations. See great soil group.

BASIC ANHYDRIDE (BASIC OXIDE) - A metal oxide that forms a base with water. See oxides.

BATHTUB EFFECT - An overflow effect commonly seen in landfills located in impermeable clay soils
where infiltration of precipitation through waste and cover materials exceeds the capacity of the soil to
absorb the normal rainfall. Springs of leachate may appear around the site perimeter.

BEDROCK - (i) Any solid rock exposed at the earth's surface or overlain by unconsolidated material.
(ii) The solid rock on which alluvial gold rests.

BERM - A narrow bench or dike-like barrier of earth commonly built to contain spills or liquid waste.

BICARBONATE - A salt containing a metal and the radical hydrogen carbonate (HCO3), e.g., NaHCO3.

BIODEGRADABLE - The ability to break down or decompose rapidly under natural conditions and
processes.

BIODEGRADATION -  Decomposition of substances or materials into more elementary compounds by
the action of microorganisms, such  as bacteria or fungi.

BIOLOGICAL WASTE - Any waste derived or originating from living organisms: microorganisms,
meso- and macro animals, plants, and also humans.

BIOMASS - All of the living material in a given area; often refers to vegetation. Also called "biota."
Guide to Site and Soil Description

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                                                                                 Appendix B
BIOME - A large, easily recognized community unit formed by the interaction of regional climates with
regional biota and substrates. In a given biome the life form of the climatic climax vegetation is
uniform. Thus, the climax vegetation of the grassland biome is grass, although the dominant species
of grass may vary in different parts of the biome.

BIOTA - All of the living organisms, macro, meso or micro, that exist in a given  area or environment.

BIOTIC COMMUNITY - A naturally occurring assemblage of plants and animals that live in the same
environment and are mutually sustaining and inter-dependent.

BLOCK (BLOCKY) - (i) An angular fragment over 256 mm in diameter showing little or no modification
in form due to transportation; similar in size to a boulder.

BLUE-GREEN ALGAE - See cyanobacteria.

BORING LOGS - Engineering and  geologic  descriptions of exploration drill holes commonly utilized
during the design and planning phases of construction projects. Also may provide useful descriptions
relevant to waste disposal sites.

BORROW PIT - An excavated area where earth materials (not rock) have been removed to use for fill
or construction elsewhere. Some borrow pits may be subsequently used as dumps, landfills or waste
disposal sites.

BULK AREA - The total area, including solid particles and pores, of a cross-section through an
arbitrary quantity of soil; the area counterpart of bulk volume.

BULK DENSITY - The ratio of the mass of dry solids to the bulk volume of the soil.
                     B.D. =  gms of soil  dried to 105° C/cc of soil volume obtained in the field.

BULK WASTE - Large items of solid or oversize waste that preclude or that complicate handling by
normal solid waste collection, processing or disposal methods.

BURIAL GROUND (GRAVEYARD) - A disposal site for  radioactive waste materials that uses earth or
water as a shield.

BURIED SOILS - A soil is considered to be  a buried soil if there is a surface mantle of new material
such as alluvial, loessal, or other depositional surface mantle that is 50 cm or more thick or if there is
a surface mantle between 30 and 50 cm thick and the thickness of the mantle is at least half that of
the named diagnostic horizons that are preserved in the buried soil. Buried soils may be encountered
in the natural environment as well as at disturbed sites.

CALICHE - (i) A zone near the surface, more or less cemented by secondary carbonates of Ca or Mg
precipitated from the soil solution. It may occur as a soft thin soil horizon, as a hard thick bed, or as a
Guide to Site and Soil Description               B-6

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                                                                                Appendix B
surface layer exposed by erosion, (ii) Alluvium cemented with NaNO3 NaCI, and/or other soluble salts
in the nitrate deposits of Chile and Peru.

CALIFORNIA LIST OF WASTES - RCRA hazardous waste that contains cyanides, RCRA metals, or
PCBs, or waste that is corrosive (i.e., pH of 2 or less); and any liquid or nonliquid hazardous waste
containing halogenated organic compounds (HOCs). See RCRA, halogenated wastes, and PCBs.

CAP - A layer of clay or other highly impermeable material installed over the top of a closed landfill to
prevent entry of rainwater and minimize production of leachate.

CAPILLARY FRINGE - A zone in the soil just above the plane of zero gauge pressure that remains
saturated or almost saturated with water. The extent can be inferred from the retentivity  curve and
depends upon the size-distribution of pores.

CARBONATE - A salt or ester of carbonic acid;  a compound containing the radical carbonate (CO32").

CATALYSIS - A modification, especially an increase, in the rate  of a chemical reaction induced by
material unchanged chemically at the end of the reaction.

CATION EXCHANGE CAPACITY (CEC) - The sum total of exchangeable cations that a soil can
adsorb, expressed in milliequivalents per 100 grams or per gram of soil. Usually determined by
ammonium acetate at pH 7. See ion exchange.

CERCLA - Comprehensive Environmental Response Compensation and Liability Information System
Act of 1980. CERCLA focuses on inactive or uncontrolled sites. The major concern of CERCLA is
cleanup of hazardous substances releases at uncontrolled or abandoned hazardous waste sites.
Compare with RCRA. See hazardous substance, hazardous waste site, and Superfund.

CFR (40 CFR) - Code of Federal Regulations dealing with protection of the environment.

CHANGES OF STATE  - Interconversions between the solid, liquid and gaseous states.

CHARACTERISTIC WASTE - A  solid waste that is a hazardous  waste because it exhibits one or more
of the following hazardous characteristics: ignitability, corrosivity, reactivity, or toxicity. See also toxicity
characteristic rule and toxicity characteristic leaching procedure.

CHELATES - Certain organic chemicals, known  as chelating agents, form ring compounds in which a
metal is held between two or more atoms strongly enough to diminish the rate at which  it becomes
fixed by soil, thereby making it more available for plant uptake. See organic complexation, inorganic
complexation.
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                                                                                  Appendix B
CHELATING AGENT - An agent, such as a humus fraction, that has more than one atom and that
may be bonded to a central metal ion at one time to form a ring structure. Chelating agents can be
common water or soil pollutants.

CHELAT1ON - The retention of a metallic ion by two atoms of a single organic molecule.

CHEMICAL LANDFILL - A landfill used for disposal of chemicals. See landfill.

CHEMICAL PRECIPITATION - For RCRA corrective action,  solubilized metals are separated from
water by precipitating them with insoluble salts.

CHEMICAL SPECIATION - The form in which  an element is present, e.g., a species of aluminum in
the trivalent form, AI3+.

CHEMICAL WASTE - Any organic or inorganic waste of a particular molecular identity generated by
various industrial manufacturing processes or other processes.

CLASSIFIED WASTE - Waste material having a security classification in accordance with regulation 50
U.S.C. 401 and Executive Order 11652.

CLAY - (i) A soil separate consisting of particles  < 0.002 mm in  equivalent diameter, (ii) A textural
class. See soil texture  and soil separates.

CLAY MINERAL - (i) Any crystalline inorganic substance of clay size (i.e., 2/;m equivalent spherical
diameter),  (ii)  Any phyllosilicate of clay size. See phyllosilicate mineral, (iii) Naturally occurring,
inorganic, crystalline phyllosilicate (sheet layer silicate mineral) materials found in soils and other
earthy deposits; not limited to particle size of 0.002 mm diameter or less.

CLAY PARTICLES - A clay-sized particle consisting of both mineral and organic constituents. See
clay.

CLAYPAN - A dense, compact layer in the subsoil having a much higher clay content than the
overlying material, from which it is separated by  a sharply defined boundary; formed by downward
movement of  clay or by synthesis of clay in place during soil formation. Claypans are usually hard
when dry, and plastic and sticky when wet.

CLEAN FILL - Inert materials, especially soils or rock that are commonly used to fill depressions prior
to construction of large buildings, parking lots or housing developments. May also be used to cover
deposited wastes.

CLEANUP - Actions taken to deal with a release or threat of release of a hazardous substance that
could affect humans and/or the environment. The term "cleanup" is sometimes used interchangeably
with the terms remedial action, removal action, response action, or corrective action.
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                                                                                 Appendix B
CLIMATE AND WEATHER - Climate: the average course or condition of the weather for the site and
region over a period of years as exhibited by temperature, meteoric precipitation, and wind.  Weather:
the state of the atmosphere at the site and region during the time of study with respect to heat or
cold, wetness or dryness, calm or storms, clearness or cloudiness, and barometric pressure.

CLIMATE TYPES - The climate of an area designated as the location in which it is found, e.g.,
continental.

CLIMATIC REGIME - A province or region of the earth's surface characterized by an essentially
homogeneous climate.

CLOD - A soil mass or lump produced artificially usually when a wet soil is cultivated or otherwise
manipulated.

CLP - See Contract Laboratory Program.

COARSE-TEXTURED SOIL - A description of a class of  soil texture which is characterized by sands,
loamy sands, and sandy  loams (except for very fine sandy loam).

CODE OF FEDERAL REGULATIONS - See CFR.

COLLOID - (i) Substances made up of very fine particles larger than most molecules. Soils (and
plants) contain a large amount of solid material in the colloidal state. The upper size limit is 0.1 mm.
(ii) A substance that, when apparently dissolved in water, diffuses not at all  or very slowly through a
membrane and usually has little effect on freezing point,  boiling point, or osmotic pressure of the
solution; a substance in a state of fine subdivision, with particles ranging from 10"5 to 10"7 cm in
diameter. See soil colloids.

COLOR, CHROMA - One of the three variables of color. The relative purity, strength, or  saturation of
a color;  directly  related to the dominance of the determining wavelength of the light and inversely
related to grayness.  See Munsell Color System.

COLOR, HUE -  One of the three variables of color.  It is  attributed to light of certain wavelengths and
changes with the wavelengths. See Munsell Color System.

COLOR - The phenomena of light or visual perception of the soil's physical appearance in terms of
hue, lightness, and saturation; measurement is by reference to standard color charts (e.g., Munsell
color system for hue,  value, and chroma) to make up a specific color notation.

COLOR, VALUE - One of the three variables of color.  The relative lightness or intensity of color.
Approximately, a function of the square root of the total amount of light. See Munsell Color System.
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                                                                                Appendix B
COMBUSTIBLE WASTE - Any waste materials that are burnable, e.g., wood, paper, cloth, certain
plant parts, food, plastics, paints, solvents, and fuels.

COMETABOLISM (COOXIDATION) - The metabolism by microorganisms of a compound that the cell
is unable to use as a source of energy or an essential nutrient.

COMPACTION - (i) The squeezing together of soil particles under mechanical load by rolling,
tamping, or vibration to expel air, usually by the weight of farm, construction, and other equipment;
vehicles; and animal and foot traffic, (ii) Increasing the soil bulk density and concomitantly decreasing
the soil porosity by application of mechanical forces to the soil.

COMPLEX - A compound formed between a metal atom or ion with acceptance of one or more
electron pairs, and ions or neutral molecules that donate electron pairs.

COMPLEXATION - The formation of complex ions or compounds. Also see chelation.

COMPOST - A mixture of garbage and degradable trash with soil in  which certain bacteria in the soil
break down the garbage and trash into organic fertilizer.

COMPRESSIBILITY - The property of a soil pertaining to its susceptibility to decrease in bulk volume
when subjected to a load. Not to be confused with compaction.

CONCRETION - A small module or lump of relatively concentrated compound such as calcium
carbonate, iron oxide, etc. found in many soils, and varying in shape, hardness, size, and color.

CONSISTENCY - The resistance of the soil material to  deformation or rupture; the degree of cohesion
of the soil mass, and as described at various soil moisture contents.  Also see Atterberg limits, liquid
limit, plastic limit.

CONTAINER - Any portable device in which a material is stored, transported, disposed of, or
otherwise handled.

CONTAINMENT - Capping, slurry walls, etc., around waste or contaminated soils to prevent surface
and ground water migration and contaminant transport.

CONTAMINANT - Any  physical, chemical, biological, or radiological substance or matter that has an
adverse affect on air, water, soil, or biota.

CONTAMINANT DETECTABLE  CONCENTRATION - Any concentration of a contaminant in a
medium, such as soil or water, that is greater than or equal to the particular method detection limit.
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                                                                               Appendix B
CONTAMINANT DISPERSION - Spread of a contaminant in a system, such as soil, one phase of
which is in the form of finely divided particles, e.g., a contaminant in soil solution, distributed
throughout a bulk substance, e.g., a metal dispersed in soil solid particles.

CONTAMINANT MIGRATION - The movement of contaminants on or off-site due to soil permeability,
credibility, depth to ground waster, flooding potential, landform and other factors.

CONTAMINANT MIGRATION POTENTIAL - The potential for a contaminant to migrate off-site.
Factors for high potential include (1) slope with relatively  impermeable bedrock, (2) karst topography,
(3) little topographic relief with ground water at or very near the surface, and (4) a shallow soil depth
(profile), fractured bedrock and high ground water table.

CONTAMINANT RETARDATION - The hinderance, delay, or slowing of progress of contaminant
migration through soil and to ground water.

CONTINGENCY PLAN - A document setting out an organized, planned, or coordinated course of
action to be followed in case of a fire, explosion,  or release of hazardous waste constituents which
could threaten human health or the environment.

CONTRACT LABORATORY PROGRAM (CLP), Superfund - Laboratories under license to EPA, which
analyze samples taken from wastes, soil, air and water or carry out  research projects.

CONTRASTING SOIL - A soil that does not share diagnostic criteria and does not have or perform
similar to the soil with which it is being compared.

COPROGENOUS EARTH - (i) Sediments  or soil derived from or containing excrement, dung or fecal
materials, (ii) Sedimentary peat. See limnic materials.

CORROSION POTENTIAL - See corrosivity.

CORROSIVE - A chemical  agent that reacts with the surface of a material, causing it to deteriorate or
wear away.

CORROSIVE WASTE - Waste that has the ability to corrode the standard materials of a container or
have the ability to dissolve toxic  contaminants. Aqueous wastes < pH 2 or > pH  12 are considered
corrosive.

CORROSIVITY (CORROSION POTENTIAL) - The ability  of the soil  to wear away and degrade metal
materials with time,  usually by chemical and microbial action, and as determined  by soil
characteristics.

COVALENT BONDING - Bonding based upon electron-pair sharing; the attraction between  two atoms
that share electrons. See semiconducting  elements.
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                                                                                 Appendix B


COVER, VEGETATION - The area of ground covered by the sum total of plants in an area. See
ground cover.

CRITERIA - Descriptive factors taken into account by EPA in setting standards for various pollutants.
These factors are used to determine limits on allowable concentration levels, and to limit the number
of violations per year. When issued by EPA, the criteria provide guidance to the states on  how to
establish their standards.

CRITICAL DEPTH - The boundary limit of the zone of discernible soil, microbial activity, or depth to
ground water.

CROSS CONTAMINATION, Superfund - The transfer of contaminants from their known or suspected
location into a noncontaminated area; a term usually applied to sampling activities. See sampling
activities.

CRUMB - (i) Very porous granular structure in soils; a porous aggregate of soil particles, (ii) In
agriculture, a soft, rounded ped from  1 to 5 mm in diameter. See ped.

CRUST - See soil crust and desert crust.

CULTURE - A population of microorganisms cultivated in an artificial growth media. A pure culture is
grown from a single cell;  a mixed culture consists of two or more microorganisms growing together.

CULTURE MEDIUM - A mixture of nutrient substances in which microorganisms are grown.

CYANIDE - Any of a group of compounds containing the carbon-nitrogen group and derived from
hydrogen cyanide. Commonly included by EPA with the priority list of inorganics, including heavy
metals, as a hazardous waste contaminant, and analyzed by CLP laboratories.

CYANOBACTERIA - Bacteria, also called "blue-green" algae, which are generally photosynthetic,
pigmented (phycobilin), unicellular or multicellular, microscopic, or forming discernible masses in or
upon soil, water,  and other substates, e.g., oil wastes, sewage, bones, shells, wood, etc. See
microflora, algae, and bacteria.

DARCY HYDRAULIC CONDUCTIVITY - See hydraulic conductivity, intrinsic permeability.

DARCY VELOCITY - A standard unit of permeability, equivalent to the passage of one cubic
centimeter of fluid of one centipoise viscosity flowing in one second under a pressure differential of
one atmosphere through  a porous medium having an area of cross section of one square  centimeter
and a length of one centimeter. See soil permeability.
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                                                                                 Appendix B
DARCY'S EQUATION - In a porous medium, such as soil, the gross velocity v of water is equal to the
hydraulic gradient /' times the hydraulic conductivity K. See hydraulic conductivity and hydraulic
gradient.

DARCY'S LAW - (i) A law describing the rate of flow of water through porous media. (Named for
Henry Darcy of Paris, who formulated it in 1856 from extensive work on the flow of water through sand
filter beds.) As formulated by Darcy the law is
                                      0 = KS(H + e)/e
where 0 is the volume of water passed in unit time, S is the area of the bed, e is the thickness of the
bed, H is the depth of water on top of the bed, and K is the coefficient dependent on the nature of the
sand, and for cases when the pressure under the filter is equal to the weight of the atmosphere, (ii)
Generalization for three dimensions: The rate of viscous flow of water in isotropic porous media is
proportional to, and in the direction of, the hydraulic gradient, (iii) Generalization for other fluids: The
rate of viscous flow of homogenous fluids through isotropic porous media is proportional to, and in the
direction of, the driving force. See hydraulic  gradient, hydraulic conductivity, and isotropic soil.

DECOMPOSITION - The breakdown of matter by bacteria and fungi into similar substances. It
changes the chemical makeup and physical appearance of materials.

DEEP WELL INJECTION STORAGE - The injection of fluids, such as for waste disposal, into wells
beneath shallow impermeable strata at depths exceeding 6.7 m (22 feet). See injection well and
disposal.

DEGRADATION RATE (CHEMICAL PERSISTENCY) - The rate at which a chemical is broken down in
the environment by hydrolysis, photodegradation, or soil metabolism;  the length of time that a parent
chemical persists in the environment.

DEGRADATION - The process whereby a compound is transformed into simpler compounds,
although products more complex than the starting material may be formed. Also see soil degradation.

DELINEATION - A portion of a landscape shown by a closed boundary on a soil map that defines the
area, shape, and location of one or more component soils plus inclusions, and/or miscellaneous area.
See soil map unit.

DELISTING - Exclusion  (or  petitioning for exclusion) of a solid waste from the definition of "hazardous
waste," even though so listed under RCRA.

DEPOSIT - Material left in a new position by a natural transporting agent such as water, ice, or gravity,
or by the activity of man. May also include materials resulting from dumping  of wastes, chemicals and
spills.

DEPTH TO GROUND WATER - Depth in feet or meters from the soil surface to the upper surface of
ground water (the water table), or that level in the ground where the water is at atmospheric pressure.
Guide to Site and Soil Description             B-13

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                                                                                  Appendix B
DESALINIZATION - The process of leaching the excess soluble salts from a soil.

DESERT CRUST - A hard layer, containing calcium carbonate, gypsum, or other binding material,
exposed at the surface  in desert regions. See soil crust.

DESORPTION - The displacement of ions from the solid phase of the soil solution by a displacing ion.

DIAGNOSTIC SOIL HORIZONS - In soil survey, these are quantitatively defined features used to
differentiate between taxa in the U.S.  system of soil taxonomy. See genetic soil horizons, soil master
horizons and layers.

DIATOMS - Algae having siliceous cell walls that persist as a skeleton after death. Any of the
microscopic unicellular or colonial algae constituting the class Bacillariaceae. They are abundant in
fresh and salt waters and wet soils. Their remains are widely distributed in soils. See microflora.

DIFFERENTIAL WATER CAPACITY - The absolute value of the rate of change of water content  with
soil water pressure. The water capacity at a given water content will  depend on the  particular
desorption or adsorption curve employed. Distinction should be made between volumetric and specific
water capacity. See soil water  (moisture).

DIFFUSION - See soil nutrient diffusion.

DILUTION - Thinning down or weakening of a compound by mixing  with water or other solvents.
Contaminants introduced into soil may become spatially diluted over time.

DIRECT COUNTS - In soil microbiology, a method of estimating the total number of microorganisms
in a given mass of soil by direct microscopic examination.

DIRECTIONAL HYDRAULIC CONDUCTIVITY - Two-directional hydraulic conductivity (vertical and
horizontal). See anisotropy and anisotropic soil.

DIRT - (i) A commonly used term  in construction, earth moving and  engineering referring to soil and
soil-like materials, including contaminated materials and debris of soil-size dimensions, (ii) Loose
packed soil or sand, (iii) Alluvial earth in placer mining, (iv) Slate and waste from coal mines, (v)  Fill
material with soil-like quantities or dimension. See spoil.

DISPERSED SOIL - A soil which has some of its smaller particles dispersed or suspended in a  liquid,
e.g., the clay particles may be dispersed in water. A dispersed soil usually runs together and becomes
plastic when wet; includes characteristics of low permeability, high bulk density, and forms hard lumps
or clods upon drying.

DISPOSAL - Final placement or destruction of the following: toxic, radioactive, or other waste surplus
or banned pesticides or other chemicals, polluted soils, and drums containing hazardous materials
Guide to Site and Soil Description              B-14

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                                                                                Appendix B
from removal actions or accidental releases. Disposal may be accomplished through use of approved
secure landfills, surface impoundments, land farming, deep well injection, ocean dumping, or
incineration.

DISSOLUTION - The separation into component parts through the process of dissolving, usually in a
solution.
DISTANCE TO RECEPTOR - The distance from the contaminated medium (soil), to a user in the
direction of ground water flow.

DISTURBED SOILS - Any soil material that has been truncated or manipulated to the extent that its
principle pedogenic characteristics have been severely altered or can no longer be recognized.

DNA PROBE - A segment of DNA to detect complimentary strands of DNA. Used to confirm  presence
of microorganisms, abundance of microorganisms, or a species of microorganisms.

DUMPS - (i) Areas of smooth or uneven accumulations or piles of waste rock or general refuse.  In an
agricultural sense, without major reclamation the areas are incapable of supporting plants, (ii) A site
used to dispose of solid wastes without environmental  controls.

DURIPAN  - A mineral soil horizon that is cemented by  silica, usually opal or microcrystalline  forms of
silica, to the point  that air-dry fragments will not slake in water or  HCI. A duripan may also have
accessory  cement such as iron oxide or calcium carbonate. Also, see iron-pan, claypan, and caliche.

ECOLOGICAL AMPLITUDE - The range of one or more environmental conditions in which an
organism or a process can function. Within this range,  e.g., optimum conditions are that range most
favorable for the organism/process. Compare tolerance, resistance.

ECOLOGICAL IMPACT - The effect that a man-made or natural activity has on living organisms and
their non-living (abiotic) environment.

ECOSYSTEM - A community of organisms and the environment in which they live.

Eh - See redox potential.

ELECTROCHEMICAL SENSOR - A device that senses either the absolute value of a quality  or
change (e.g., pH) and converts this data into an input signal for an information-gathering system. See
ion selective electrode.

ELECTROPLATING - Electrodeposition of a metal or alloy from a suitable electrolyte (current
conducting) solution. Electroplating solutions can be important soil metal contaminants.
Guide to Site and Soil Description             B-15

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                                                                                Appendix B
ELECTRICAL CONDUCTIVITY - The ratio of the electrical current density to the electric field in the
soil; expressed in the reciprocal value of its resistivity in mhos/cm, mmhos/cm or siemens/meter of soil
extract or paste and generally referable to the salt/solute content of the soil as determined at a given
moisture content and temperature.

ELEMENTAL ANALYSIS - The total amount of a chemical element, including metals, determined by
various wet and dry methods and analytical instruments. See soil chemical properties.

ENDANGERED SPECIES - Animals, birds, fish, plants, or other living organisms threatened with
extinction by man-made or natural changes in their environment. Requirements for declaring a species
endangered are contained in the Endangered Species Act.

ENGINEERED SOILS - Soils used for engineering purposes and rated in terms of suitability,
limitations, and restrictive features.

ENVIRONMENT - The sum of all external conditions affecting the life, development, and survival of an
organism.

ENVIRONMENTAL RESPONSE TEAM - EPA experts currently located in Edison, NJ, and Cincinnati,
OH, who can provide around-the-clock technical assistance to EPA regional offices and states during
all types of emergencies involving hazardous waste sites and spills of hazardous substances.

ENVIRONMENTAL SAMPLES, Superfund - Samples with low concentrations of hazardous
contaminants. See sample, low concentration, Superfund.

EPA HAZARDOUS WASTE NUMBER - A number assigned by EPA to waste that is hazardous by
definition; to each hazardous waste listed in 40 CFR 261 Subpart D from specific and nonspecific
sources identified by EPA (F, K, P, U); and to each characteristic waste identified in 40 CFR 261
Subpart C, including wastes with ignitable (D001), reactive (D002), corrosive (D003),  and EP toxic
(D004-D017) characteristics.

EPIPEDON - A diagnostic soil horizon that forms at the surface and has been either appreciably
darkened by organic matter or eluviated or, as a minimum, rock  structure has been destroyed. There
can be only one epipedon formed in the mineral horizon (s) of a soil, but it may be overlain with
organic materials. There are seven diagnostic epipedons. For details, see USDA Soil Survey Staff,
Keys to Soil Taxonomy, Tech. Monogr. No. 19, 1990 or other soil taxonomic reference.

ERODIBILITY - The vulnerability or degree of susceptibility of soil to erosion processes.

EROSION - (i) The wearing away of the land surface by running water, wind, ice, or other geological
agents, including such processes as gravitational creep, (ii) Detachment and movement of soil or rock
by water, wind, ice or gravity. For terms to describe different types of water and wind erosion, see Soil
Science Society of America, Glossary of Soil Science Terms, 1987.
Guide to Site and Soil Description             B-16

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                                                                                 Appendix B
EROSION CLASSES - A grouping of erosion conditions based on the degree of erosion or on
characteristic patterns. (Applied to accelerated erosion; not to normal, natural, or geological erosion.)
Four erosion classes are recognized for water erosion and three for wind erosion. Specific definitions
for each vary somewhat from one climatic zone, or major soil group, to another. For details see USDA
Soil Survey Staff, SCS, 1981. Soil Survey Manual. U.S. Dep. Agric. Handbook 18, or other soil survey
manual.

ESSENTIAL ELEMENTS - Those elements which must be present in the soil for a plant to grow
normally. Both macro and micronutrients are necessary. See macro and micronutrients.

EVAPORATION - The process whereby a liquid changes its state and becomes a vapor. In
agriculture, it is the diffusion of water as a vapor from the surface of plants or soil to the atmosphere.

EVAPORTRANSPIRATION - The movement of liquid  (usually water) from plant surfaces, including soil
algal- and lichen-crusts, by a combination of evaporation and transpiration; the loss of water from the
soil both by evaporation and by transpiration from the plants growing in the soil.

EXCEEDANCE - Violation of environmental protection standards by exceeding allowable limits or
concentration levels.

EXCHANGEABLE SOIL IONS - Those ions held by a soil complex which may be readily replaced by
other ions. Both anions and cations are exchangeable. See anion and cation exchange capacity.

EXPERT SYSTEM - (i) Generally considered to be a branch of artificial intelligence; with its
knowledge-based system, can function as an "expert" to make higher-level decision based on varying
performance levels, (ii) A "man and machine" system with specialized problem-solving expertise. See
knowledge base. Also see the following references:  Coulson et al., 1987; Fang et al., 1990; Olivero
and Bottrell, 1990; and Schmuller, 1990.

EXPOSURE - (i) The amount of radiation or pollutant  present in an environment which represents a
potential health threat to the living organisms in that environment; (ii) Human contact with a physical,
chemical or biological agent through dermal absorption, inhalation or ingestion.

EXTREMELY HAZARDOUS SUBSTANCE - Any of more than 400 chemicals, subject to revision,
identified by the EPA, or on the basis of toxicity, and listed under SARA Title III. The list is subject to
revision. Also see SARA.

FACILITY - All contiguous land and structure, other appurtenances, and improvements on the land
used for treating, storing, or disposing of hazardous waste. A facility may consist of several treatment,
storage, or disposal operational units e.g., one or more landfills, surface impoundments, or
combinations of them.
Guide to Site and Soil Description             B-17

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                                                                                 Appendix B
FACULTATIVE MICROORGANISMS - Any microorganisms that are able to carry out both options of a
mutually exclusive process e.g., aerobic and anaerobic metabolism. May also be used in reference to
other processes, such as photosynthesis.

FERMENTATION - Chemical reactions accompanied by living microbes that are supplied with
nutrients and other critical conditions such as heat, pressure, and light that are specific to the reaction
at hand.

FERTILE SOIL - A soil having the ability to supply nutrients essential to plant growth. See
macronutrients and micronutrients. Compare with productive soil.

FERTILITY POTENTIAL - The ability or status of the soil to supply nutrients necessary for plant
growth; usually determined by soil tests (i.e., chemical, physical or biological procedures that estimate
a property of the soil pertinent to the suitability of the soil to support plant growth).

FERTILIZER - Any organic or inorganic material of natural or synthetic origin (other than liming
materials) that is added to a soil to supply one or more elements essential to the growth of plants.

FIBRIC SOIL MATERIAL - One of three kinds of basic organic soil materials. A fiber is a fragment or
piece of plant tissue, excluding  live roots, that is large enough to be retained on a 100-mesh sieve
(openings  0.15 mm in diameter) and that retains recognizable cellular structure of the plant from which
it came. Also, see hemic and sapric soil materials.

FIELD CAPACITY - The field water capacity or in situ water content on a mass or volume basis which
remains in a soil 2 or 3 days after it has been wetted with water and after free drainage is negligible.
See available water.  (Also, may  be applied to liquid chemicals other than water to reach field
capacity.)

FIELD CROPS - Vegetation commercially cultivated and produced for the primary purpose of
providing food  and clothing for  humans or food for domestic livestock.

FIELD INVESTIGATION TEAM  (FIT), Superfund - A team composed of two and up to six or more
members needed in a hazardous  substance site investigation. The level of site operations determines
the minimum number of team members.  Primary function of the FIT  is to conduct field work needed to
gather information according to the approved work plan, to conduct remedial response activities, and
to meet the goals of the investigation of hazardous waste disposal sites.

FIELD-SATURATED HYDRAULIC CONDUCTIVITY - Saturated hydraulic conductivity of a porous
medium, e.g., soil, containing entrapped  air. See hydraulic conductivity, saturated.

FINE-TEXTURED SOIL  - A description of a class of soil texture which is characterized by the
dominant presence of the smaller soil particles, clay or silt. See clay and silt.
Guide to Site and Soil Description              B-18

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                                                                                  Appendix B
FLOCCULATION - The coagulation of dispersed particles in a medium, e.g., in a clay suspension the
colloids are dispersed (present as separate particles and not as aggregates or group). See dispersed
soil.

FOLIAR ANALYSIS - The analysis of a prepared sample of plant material into  its content of various
elements. This examination may be  preferable to an analysis of the soil in which the plant is growing.
Foliar analysis provides an estimate of the quantity available of the elements the plant is able to
extract from the soil, rather than the data supplied by a soil sample analysis, which estimates which
quantities of elements the soil contains.

FOLIAR DIAGNOSIS - An estimation of the mineral contents of plants by means of chemical analysis
tests carried out on the whole or part of the plant.  By this method an indication is obtained of which
elements the plant is able to extract from the soil in which it grows. Any excess or  deficiency
(including toxicity) in the plant may be diagnosed.

FORBS - An herbaceous plant that  is not a grass or grasslike; for example, sunflowers. Also see
herbs, plant type,  ground cover.

FLUX DENSITY - The volume of water passing through a unit cross-sectioned area (perpendicular to
the flow direction) per unit time (in a soil). See hydraulic conductivity.

FRAGIPAN - A natural subsurface horizon with high bulk density and/or high mechanical strength
relative to the solum above, seemingly cemented when dry, but when moist showing a moderate to
weak  brittleness. The layer is low in organic matter, mottled, slowly or very slowly permeable to water,
considered to be root restricting, and usually shows occasional or frequent bleached cracks forming
polygons. It may be found in profiles of either cultivated or virgin soils but not  in calcareous material.

FREE LIQUIDS - Liquids which readily  separate from  the solid portion of a waste under ambient
temperature and pressure.

FROZEN SOIL - A soil with a horizon or layer containing permanent ice.

FUNGI - (Singular: Fungus) Molds, mildews, yeasts, mushrooms, and puffballs, a group of organisms
that lack chlorophyll (i.e., are not photosynthetic) and are usually non-mobil, filamentous, and
multicellular. Some grow in the ground, others attach  themselves to decaying trees and other plants,
getting their nutrition from decomposing organic matter. Some cause disease, others stabilize sewage
and break down solid wastes in  composting.

GENERATOR - A facility or mobile source that emits pollutants into the air and/or releases hazardous
wastes into water or soil.
Guide to Site and Soil Description              B-19

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                                                                                  Appendix B
GENETIC SOIL HORIZONS - In soil survey, genetic horizons are not the equivalent of the diagnostic
horizons of the U.S. Soil Taxonomy. Designations of genetic horizons express a qualitative judgment
about the vector of changes that are believed to have taken place.

GEOLOGICAL AND GEOPHYSICAL LOGGING, Superfund - A detailed systematic and sequential
record of the progress of drilling a well or borehold, or of excavating pits and trenches at a hazardous
waste site. The record of geological logging is kept on printed log forms and may include notes on
the following:
       soil and rock classifications and descriptions, outcrop descriptions, depths and thicknesses of
       the earth materials penetrated, groundwater conditions, origin and geologic structures, drilling
       progress, borehold geophysical logging, sampling, type of equipment used, unusual or
       significant conditions, and date of drilling location of boreholes, etc.
See US  EPA, 1987, A Compendium of Superfund Field Operations Methods, EPA/540/P-87/001, for
additional details.

GEOLOGICAL RECONNAISSANCE STUDY, Superfund - A general, exploratory examination or
survey of the main features (or certain specific features) of a region, usually conducted as preliminary
to a more detailed survey, and to identify the major geological or physical features at or near the
hazardous waste site. Geological reconnaissance studies are conducted early in project site
investigations as part of the site characterization process. See US EPA, 1987, A Compendium of
Superfund Field Operations Methods, EPA/540/P-87/001, for further details.

GEOLOGY - (i) Scientific study of the origin, history and structure of the earth, (ii) The structure of a
specific  geologic region.

GLEYED SOIL -  A soil with horizons in which water-logging and the lack of oxygen have resulted in
materials (mottles) of a relatively neutral grey color. See strong gleyed soil.

GRANITE - See granular rock structures.

GRANULAR ROCK STRUCTURES - Rock texture as determined by the size of the constituent grains
or crystals.
       Basalt - A fine-grained, dark-colored igneous (volcanic) rock.
       Granite - A crystalline plutonic rock (i.e., derived from magma, naturally  occurring mobile rock
       material) composed of alkalic feldspar and quartz.
       Limestone - (i) A sedimentary  (formed of sediment) rock composed principally of calcium
       carbonate, mainly as calcite. (ii) A rock containing > 80% calcium carbonate or magnesium
       carbonate.
       Quartzite - (i) A granulose metamorphic rock composed mainly of quartz, (ii) Sandstone
       cemented by silica.
       Sandstone - A compacted sedimentary rock composed mainly of quartz grains silicon dioxide
        (SiO2) similar in size to sand (0.06 - 2 mm).
Guide to Site and Soil Description              B-20

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                                                                                Appendix B
GRAVEL - A loose or unconsolidated deposit of pebbles, cobbles (rock between 64 and 256 mm in
diameter), or boulders. See soil mineral fraction.

GREAT SOIL GROUP - One of the categories in the system of soil classification that has been used in
the United States for many years. Great soil groups place soils according to soil moisture and
temperature, base saturation status,  and expression of horizons. See soil classification.

GROUND COVER - (i) The extent, nature,  kind and distribution of vegetation in a site or area, (ii) The
plants or plant parts, living or dead, on the surface of the ground. Vegetative cover or herbage cover
is composed of living plants; litter cover, of dead parts  of plants, (iii) The area of ground covered by
plants of one or more species.  See basal area.

GROUND DATA - Supporting data collected on the ground, and information derived therefrom, as an
aid to the interpretation of remotely recorded surveys, such as airborne imagery, etc. Generally, this
should be performed concurrently with the airborne surveys. Data as to weather, soils, and vegetation
types and conditions are typical.

GROUND WATER - The supply of usually  fresh water found beneath the earth's surface (rock, ground
or soil), usually in aquifers, which is often used for supplying wells and springs and is a major source
of drinking water.

GROUND-WATER HYDROLOGY - The science dealing with the movement of the soil solution in what
may be considered the saturated zone of the soil profile. Also see soil hydrology.

GROUP I ELEMENTS (METALS) - See alkali metals.

GROUP II ELEMENTS (METALS)  - See alkaline earth metals.

GROUP III ELEMENTS - The boron family. All elements in this group form the +3 oxidation state.
Elements include the nonmetal (metalloid)  boron, and metals aluminum, gallium, indium and tellurium.
Boron tends to resemble silicon in its chemical properties.

GROUP IV ELEMENTS - The carbon family. All elements in this group form the +4 oxidation state.
They include carbon (a nonmetal), silicon and germanium (semiconductors), and the metals tin and
lead. The +2 oxidation state becomes increasingly stable down the carbon family. The +2 state is
most important in the chemistry of tin and  lead.

GROUP V ELEMENTS - The nitrogen family. The elements in this group lack three electrons of a
noble gas configuration. Nitrogen and phosphorus are  the nonmetals. Arsenic and antimony are the
semiconducting elements. Bismuth is a metal. Oxidation states of +3, -3,  and  +5 are common for all
the elements.
Guide to Site and Soil Description             B-21

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                                                                                 Appendix B
GROUP VI ELEMENTS - The oxygen family. The elements in this group have two electrons short of
noble gas configurations. Oxygen and sulfur are the nonmetallic members. Selenium and tellurium are
classed as semiconducting elements. Polonium is a rare radioactive substance with similarities to both
tellurium and bismuth but is mainly metallic in its behavior. By the transfer of two electrons from
metallic atoms, dinegative ions are formed by the Group VI elements. Other than oxygen, the other
elements are much less electronegative and have oxidation states of +4 and +6. Sulfur and selenium
both form octatomic molecules. There are polyatomic anions of sulfur, selenium and tellurium.

GROUP VII ELEMENTS - The halogens. Nonmetals that include fluorine, chlorine, bromine, iodine  and
astatine. All have high electron affinities, high electronegativities and high ionization energies, they
react readily to form singly charged anions  (or a single covalent bond), and in such compounds have
the -1 oxidation state. Also see salts.

HABITAT - The place where a population (e.g , human,  animal, plant, microorganism) lives and its
surroundings, both living and non-living.

HALOGENATED WASTES - Any liquid or nonliquid hazardous waste containing halogenated organic
compounds. (Halogen elements include fluorine,  chlorine, bromine, iodine and astatine.)

HALOTOLERANCE - See saline soil and salt tolerance.

HARDPAN - A hardened soil layer, in the lower A or in the B horizon, caused by cementation of soil
particles with organic  matter or with materials such  as silica, sesquioxides, or calcium carbonate. The
hardness does not change appreciably with changes in water content and pieces of the hard layer do
not slake in water. See caliche, claypan, and duripan.

HAZARD - A probability that a given pollutant, such as a pesticide, will have an adverse  affect on
man, animals, or the environment in a given situation.

HAZARDOUS IDENTIFICATION - Providing information  on which facilities have extremely hazardous
substances, what those chemicals are, and how much there is at each facility. The process also
provides information on how the chemicals are stored and whether they are used at high
temperatures.

HAZARDOUS RANKING SYSTEM  (HRS) - The principle screening tool used by EPA to  evaluate risks
to public health and the environment associated with abandoned or uncontrolled hazardous waste
sites. The HRS generates a score based on the potential  of hazardous substances spreading from
the site through the air, surface water, or ground water and on other factors such as nearby
population. This score is the primary factor in deciding if the site should be on the National Priorities
List and, if so, what ranking it should have compared to other sites on the list.

HAZARDOUS SAMPLES, Superfund - Samples with medium and high concentrations of hazardous
contaminants. See sample, medium concentration and high concentration, Superfund.
Guide to Site and Soil Description              B-22

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                                                                              Appendix B
HAZARDOUS SUBSTANCE - (i) Any material that poses a threat to human health and/or the
environment. Typical hazardous substances are toxic, corrosive, ignitable, explosive, or chemically
reactive, (ii) Any substance named by EPA to be reported if a designated quantity of the substance is
spilled in the waters of the United States or if otherwise emitted into the environment.

HAZARDOUS WASTE - A broad term usually used to denote by-products and waste materials from
industry, commercial establishments, and institutions that pose an unreasonable risk to the
environment, specified property, and human  health and safety.  Includes radioactive wastes. Also see
solid waste toxicity.

HAZARDOUS WASTE ADVERSE EFFECTS  - Environmental damage or destruction to site habitat,
animals, plants, or human health, and contamination of media: soil, water, and air.

HAZARDOUS WASTE CONSTITUENT - A constituent that causes the waste to be listed as a
hazardous waste under 40 CFR Part 261 Subpart D.

HAZARDOUS WASTE DISPOSAL - Removal or movement of hazardous wastes to  landfills or
impoundments. See hazardous waste site.

HAZARDOUS WASTE DISPOSAL SITE - See hazardous waste site.

HAZARDOUS WASTE ENVIRONMENTAL SAMPLE - Representative samples of waste procured
according to a developed sampling strategy and plan.

HAZARDOUS WASTE IDENTIFICATION, Superfund - (i) A hazardous waste by source or chemical
name as classified and listed by EPA, and (ii) Description of waste properties that may be harmful to
human health or the environment. These hazardous properties include ignitability, corrosivity,
reactivity, toxicity (determined by the extraction  procedure), radioactivity,  infectiousness, phytotoxicity,
teratogenicity, and mutagenicity.

HAZARDOUS WASTE IMPOUNDMENT - See hazardous waste surface impoundment.

HAZARDOUS WASTE LANDFILL - A disposal facility or area in which hazardous wastes are placed
directly or onto the ground.

HAZARDOUS WASTE LEACHATE - The liquid  that forms as wastes decompose (in a landfill) and mix
with meteoric precipitation (rain water) and can enter ground water.

HAZARDOUS WASTE MANAGEMENT UNIT - A contiguous area of land on or in which hazardous
waste is placed, or the largest area in which there is significant likelihood of mixing  hazardous waste
constituents in the same  area. A unit may be a  surface impoundment, waste pile, land treatment area,
landfill cell, incinerator, tank and its associated  piping and underlying containment system, or
container storage  area. A container alone does not constitute a unit.
Guide to Site and Soil Description             B-23

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                                                                               Appendix B
HAZARDOUS WASTE PROPERTIES - Waste properties that may be harmful to human health or the
environment:  ignitability, corrosivity, reactivity, toxicity (determined by EPA's extraction procedure),
radioactivity, infectiousness, phytotoxicity, and mutagenicity.

HAZARDOUS WASTE REACTIVITY - Those wastes that may react spontaneously; may react violently
with water; or could generate toxic fumes when mixed with water or exposed to basic or mild acid
conditions.

HAZARDOUS WASTE SAMPLING STRATEGY - A strategy of sampling of waste procured according
to a developed sampling strategy and plan.

HAZARDOUS WASTE SITE - An area of land (or conceivably, water)  or a location at which hazardous
materials are stored, treated, disposed of, placed, or otherwise came to be located. This includes all
contiguous  land, structures, other appurtenances, and improvements on the land used for treating,
storing, or disposing of hazardous materials.  A site may consist of several treatment, storage, or
disposal facilities (e.g., impoundments, containers,  buildings, or equipment).

HAZARDOUS WASTE SITE CHARACTERIZATION - The distinguishing qualities or peculiarities used
to describe  or represent a hazardous waste site.

HAZARDOUS WASTE STORAGE - The containment  of hazardous waste, either temporarily or for a
prolonged period of years, so as not to constitute disposal of the waste.

HAZARDOUS WASTE STREAM - A stream defined as hazardous, or one that contains substances
according to 40 CFR 261, or are exhibiting one or more characteristics of hazardous waste:
corrosivity, ignitibility, reactivity or toxicity.

HAZARDOUS WASTE, Superfund - A solid waste  or a combination of solid wastes, which because of
its quantity,  concentration, or physical, chemical or infectious characteristics may (1) cause or
significantly contribute to an increase in serious irreversible, or incapacitating reversible illness; or (2)
pose a substantial present or potential hazard to human health or the environment when improperly
treated, stored, transported, or disposed or, or otherwise managed.

HAZARDOUS WASTE SURFACE IMPOUNDMENT - A natural depression,  man-made excavation or
dike area used to contain hazardous liquids or hazardous waste containing free liquids.
Impoundments include holding, storage, settling, and aeration ponds, pits, lagoons, and similar areas
of surface confinement. See surface impoundment, pit, pond, lagoon.

HAZARDOUS WASTE TOXICITY - See solid  waste toxicity.

HAZARDOUS WASTE TREATMENT - Any method, technique, or  process, including neutralization,
designed to change the physical, chemical, or biological character or composition of any hazardous
waste so as to neutralize such waste, or so as to recover energy or material resources from the waste,
Guide to Site and Soil Description             B-24

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                                                                                Appendix B
or so as to render such waste nonhazardous, or less hazardous; safer to transport, store, or dispose
of; or amenable for recovery, amenable for storage, or reduced in volume.

HAZARDS ANALYSIS - The procedures involved in (i)  identifying potential sources of release of
hazardous materials from fixed facilities or transportation accidents; (ii) determining the vulnerability of
a geographical area to a release of hazardous materials; and (iii) comparing hazards to determine
which present greater or lesser risks to a community.

HEAVY METAL SOIL POLLUTION - Contamination of the soil with metals having densities > 5 gm/cc,
and which do not decompose, but tend to remain in the soil indefinitely.

HEAVY METALS - Those metals  having a density  >5 gm/cc and that precipitate in acid solution by
hydrogen sulfide; comprised of 38 elements, but usually 12 metals that are most commonly used and
discharged by industry: cadmium, chromium, cobalt, copper, iron, mercury, manganese, molybdenum,
nickel,  lead, tin and zinc.

HEAVY SOIL - An  agricultural term denoting a soil with a high  clay content.

HECTARE - A metric unit of area, useful for describing larger areas of contamination. 1  hectare (ha) =
10,000 square meters (m2).

HEMIC SOIL MATERIALS - One of the three kinds of basic organic soil materials. Hemic soil materials
(Gr. hemi,  half; implying intermediate decomposition) are intermediate in degree of decomposition
between the  less decomposed fibric and  more decomposed sapric materials. They have
morphological features that give intermediate values for fiber content, bulk density, and water content.
They are partly altered  both physically and biochemically. Also, see fibric and sapric soil materials.

HERBS - Plants with one or more stems,  which dies back to the ground each year. Also see forbs,
plant type, ground cover.

HETEROTROPHIC ORGANISMS - Consumers such as humans and  animals, and decomposers -
chiefly  bacteria and fungi - that are dependent on  organic matter for food.

HIGH HAZARD  MATERIALS - Those hazardous materials which are liable to burn with extreme
rapidity or from which poisonous fumes or explosions are a concern in case of fire.

HIGH-LEVEL RADIOACTIVE WASTE - Waste primarily from spent nuclear fuels and characterized by
high-level radiation which decays (loses radioactivity rapidly). The constituent elements have not been
separated  by processing.  High-level waste must be handled by remote control behind heavy and
protective shielding. It is a serious threat to anyone who comes near the wastes without shielding.
Also compare with low-level radioactive waste.

HORIZON - See soil master horizons and layers; diagnostic and genetic horizons.
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                                                                                  Appendix B
HUMAN HEALTH AND SAFETY - Any activity or situation that can adversely affect human health or
increase the risk due to accidental exposure. Exposure includes toxic or hazardous waste sites,
hazardous or toxic chemicals and gases, radiation, etc.

HUMIDITY - The degree of wetness of the atmosphere; the amount of water vapor in the air. See
relative humidity.

HUMIC SUBSTANCES - The organic high molecular weight substances which have a high affinity for
metals and are largely insoluble in the soil water. Compare with nonhumic substances.

HUMUS - (i) Total organic compounds in soil, exclusive of undecayed, partially decomposed or
biomass materials, (ii) Organic layers of the forest floor.

HYDRAULIC CONDUCTIVITY - The rate of water movement within the soil as dependent upon soil
properties, saturated and unsaturated, and hydraulic gradient at that time.

HYDRAULIC CONDUCTIVITY (K), SATURATED - The ratio of the flux density to the hydraulic
gradient, or the slope of the flux versus gradient curve in a water-saturated medium (e.g., soil). The
moving force is the gradient of a positive pressure potential. K is affected by total  porosity of the soil,
the distribution of pore sizes, and tortuosity. See hydraulic gradient, flux density, porosity, tortuosity,
and hydraulic conductivity, unsaturated.

HYDRAULIC CONDUCTIVITY (K), UNSATURATED - The ratio of the flux density to the hydraulic
gradient, or the slope of the flux versus gradient curve in an unsaturated medium  (e.g., soil). Water in
an unsaturated soil is additionally subject to a substance pressure (suction) equivalent to a negative
pressure potential. See hydraulic gradient, flux density, porosity, tortuosity and hydraulic conductivity,
saturated.

HYDRAULIC CONDUCTIVITY CLASS - The classification of hydraulic conductivity as based upon rate
of water movement,  e.g., in soil survey: high, moderate and low.

HYDRAULIC GRADIENT (aquifer) - In an aquifer, the rate of change of total head (pressure) per unit
of distance of flow at a given point in a given direction.

HYDRAULIC GRADIENT (soil water) - (i) A vector (macroscopic) point function that is equal to the
decrease in the hydraulic head per unit distance through the soil in the direction of the greatest  rate
of decrease. In isotropic soils (which see) this will be in the direction of water flux; (ii) The rate of
change in  hydraulic head between two points indicates the direction in which water will flow.

HYDRAULIC HEAD  - The elevation with respect to a specified reference (level), usually the soil
surface, at which water stands in a piezometer connected  to the point in question in the soil.  Its
definition can be extended to soil above the water table if the piezometer is replaced by a tensiometer.
Guide to Site and Soil Description              B-26

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                                                                                 Appendix B
The hydraulic head in systems under atmospheric pressure may be identified with a potential
expressed in terms of the height of a water column.

HYDRIC SOILS - Soils that are wet long enough to periodically produce anaerobic conditions, thereby
influencing the growth of plants. See wetland.

HYDROLOGY - The science dealing with the distribution and movement of water. See agrohydrology,
ground-water hydrology, soil hydrology and surface hydrology.

HYDROLYSIS - (i) Chemical decomposition involving splitting of a bond and  addition of water, (ii) The
degradation of a contaminant by chemical reactions involving water or an aqueous solution, including
soil solution. See degradation.

HYDROPHOBIC CONTAMINANTS - Compounds that do not have a strong affinity for water.
Introduced chemical contaminants may not have an affinity for the soil water.

HYDROPHOBIC SOILS - Soils that are water repellent, often due to dense fungal mycelial mats or
hydrophobic substances vaporized and reprecipitated during fire; certain wastes, e.g., oil wastes, also
increase hydrophobicity of soils.

HYDROSTATIC PRESSURE - (i) The pressure exerted or transmitted by a fluid at rest, (ii) The
pressure at a point in a fluid at rest due to the weight of fluid above it (gravitational pressure).

HYDROUS OXIDE - Water (an indefinite amount) combined with oxygen and a metal or nonmetal.
Iron, aluminum and manganeous hydrous oxides are prominent in many soils.

HYPHA - (pi. hyphae) A filament (thread) of fungus cells. A large number of hyphal filaments (hyphae)
constitute a mycelium. Bacteria of the order Actinomycetes also produce branched mycelium.

HYDROUS MICA - A silicate clay of the 2:1 type of crystal lattice structure. See silicate clay.

HYSTERESIS - A nonunique relationship between two variables, wherein the curves depend on the
sequences or starting point used to observe the variables. Examples include  the relationships: (i)
between soil water content and soil water matric potential, and (ii) between solution concentration and
adsorbed quantity of chemical species. See soil water (moisture) content and soil water matric
potential.

IGNITABLE WASTE - (i) Waste consisting of liquids with flashpoints of less than 50 °C (140 °F), or
(ii) nonliquids that may cause fires through  friction,  or (iii)  any waste consisting of ignitable
compressed air or oxidizers.

ILLITE - A hydrous mica colloidal clay. See silicate clays.
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                                                                                Appendix B
IMMATURE (YOUNG) SOIL - A relatively recently formed soil which has not reached equilibrium with
its environment and has only slightly formed horizons because soil forming processes have been
active for only a relatively short time. (Contrast with mature soil.)

IMMISCIBILITY - Two phases, commonly liquids that cannot completely dissolve in one another (such
as oil and water).

IMMOBILIZATION - The conversion of an element from the inorganic to the organic form in living
tissues, microbial or plant, thereby rendering it temporarily unavailable for use.

IMPEDED DRAINAGE - A condition which hinders the movement of water through soils under the
influence of gravity.

IMPERVIOUS - Soil resistance to penetration  by fluids or by roots.

IMPOUNDMENT - A body of water or liquid chemical confined by a dam, lake, floodgate, or other
confining barrier. See surface impoundment and hazardous waste surface impoundment.

INACTIVE HAZARDOUS WASTE SITE - See uncontrolled hazardous waste disposal site.

INCINERATION - (i) Burning of certain types of solid, liquid or gaseous materials, (ii) Treatment
technology involving destruction of wastes by burning at high temperatures e.g., burning sludge to
remove water content and reduce to ash for disposal. See disposal.

INCOMPATIBLE WASTE - (i) A hazardous waste which is unsuitable for placement in a particular
device or facility because it may cause corrosion or decay of contaminate materials; or
(ii) inability to commingle with another waste or material under uncontrolled conditions because to
commingle might produce heat or pressure; fire or explosion; violent reaction; toxic ducts, mists,
fumes or gases; or flammable fumes or gases.

INDICATOR - In biology, an organism, species, or community whose characteristics show the
presence of specific environmental conditions.

INDICATOR PLANTS - Plants characteristic of specific soil or site conditions,  whether natural or
disturbed.

INDURATED - (i) The process of hardening, especially by increasing fibrous elements, (ii) In soil,
refers to layer in which the soil particles are bound together into a hard layer  by various compounds,
e.g., calcium carbonate, oxides of iron, aluminum, silicon, or by humus, (iii) Rock or soil that has been
hardened or consolidated by pressure or cementation.

INDUSTRIAL WASTE - Any solid, semisolid, liquid, or gaseous-contained waste generated by
manufacturing or processing which may unreasonably endanger humans or animals and environs.
Guide to Site and Soil Description             B-28

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                                                                                  Appendix B
INFERENCE ENGINE - The software that provides the mechanism for interpreting the commands and
accessing the knowledge base to solve problems in an expert system. See expert system, and
knowledge base.

INFILTRABILITY - The flux (or rate) of water infiltration into the soil when water at atmospheric
pressure is maintained on the atmosphere-soil boundary, with the flow direction being one-
dimensionally downward. See soil infiltration and infiltration rate.

INFILTRATION - (i) The penetration of water through the ground surface into sub-surface soil or the
penetration of water from the soil into sewer or other pipes through defective joints, connections, or
manhole walls, (ii) A land application technique where large volumes of wastewater are applied to
land, allowed to penetrate the surface and percolate through the underlying soil. Also see percolation
and infiltration rate (flux).

INFILTRATION RATE (FLUX) - A soil characteristic determining or describing the maximum rate at
which water can enter the soil under specified conditions, including the presence of an excess  of
water; the volume of water (or liquid chemical) infiltrated downward into the soil per unit cross-
sectional soil area in unit time, with dimension of velocity.

INFILTRATION VELOCITY - The actual rate at which water will enter the  soil through the surface; a
rate which may differ from the infiltration (or basic) rate because of a limiting supply of water. See
infiltration rate.

INFORMATION FILE, Superfund - A file that contains accurate, up-to-date documents on a
Superfund site. The file is usually located in a public building such as a school, library, or city hall that
is convenient for local residents.

INJECTION WELL - A well into which fluids are injected for various purposes such as waste disposal,
improving crude oil recovery or solution mining. See deep well injection storage.

INITIAL ENTRY PARTY (TEAM), Superfund - The party that enters the site first, employs specialized
instrumentation to characterize site hazards, becomes familiar with the conditions and dangers
associated with the site. The major purpose of this team is to  measure existing hazards and to survey
the site to ascertain if the level of personal protection determined from preliminary assessment,  site
inspection, or site screening study must be adjusted.

INORGANIC COMPLEXATION - The attachment of a transition-metal ion to another  molecule or ion
by means of a coordinate covalent bond. See organic complexation, and chelates.

INORGANIC WASTE - Solid waste composed of matter other than plant,  animal, human, and certain
carbon compounds,  and including metals and glass.
Guide to Site and Soil Description              g-29

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                                                                                  Appendix B
INSTITUTIONAL WASTES - Solid, semisolid, and liquid wastes generated by educational, health care,
correctional, and other institutional facilities.

INTERSTICES - See pores, saturated zone.

INTRINSIC PERMEABILITY - The property of a porous material that expresses the ease with which
gases or liquids flow through it. Often symbolized by k = Krj/pg, where K is the Darcy hydraulic
conductivity, ^ is the fluid viscosity, p is the fluid density, and g is the acceleration of gravity.
Dimensionally, k is an area [L2]. See permeability, soil water, and Darcy's law.

ION ACTIVITY - Informally, the effective concentration of an ion in solution. Numerically, it approaches
the value of the ionic concentration at infinite dilution of the ion under consideration and otherwise
satisfies the formal, thermodynamic relationship between  activity and chemical potential as applied to
a single ionic species.

ION EXCHANGE - Substitution of one ion, either positive (cation) or negative (anion), for  another of
the same charge. A soil phenomenon whereby an introduced ion, including a contaminant ion, may
replace another. See anion and cation exchange capacity.

ION SELECTIVE ELECTRODE - An electrochemical sensor, the potential of which (in conjunction with
a suitable reference electrode) depends on the logarithm of the activity of a given ion in aqueous
solution; useful for determining specific ions in soils (solutions and extracts), e.g., ammonium and
nitrates. See electrochemical sensor.

IONIC  DIFFUSION - In soils, the movement of ions, e.g., nutrients, nonnutrients and certain metal
species, that result from a concentration gradient.

IONIC  SPECIES - Chemically dissociated substances (elements) in a fluid medium, such as sodium
and chloride ions formed  when salt dissolves in water. Also see metal species.

IONIC  STRENGTH - A parameter that estimates the interaction between ions in solution.  It is
calculated as one-half the sum of the products of ionic concentration and the square of ionic charge
for all the charged species in a solution.

IONS - Atoms, groups of  atoms,, or compounds, which are electrically charged as a result of the loss
of electrons (cations) or the gain of electrons (anions).

IRON-PAN - An indurated soil horizon in which iron oxide is the principal cementing agent. See
plinthite.

IRRIGATION - The intentional application of water to the  soil.

ISOTROPIC SOIL - A soil with hydraulic conductivity the same in all directions.
Guide to Site and Soil Description             B-30

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                                                                                 Appendix B
JUNK - Unprocessed and discarded materials and manufactured items usually suitable for reuse or
recycling, such as glass, rags, paper, metal, some plastics, and larger items.

KAOLINITE - An aluminosilicate mineral of the 1:1 crystal lattice group, consisting of one silica
tetrahedral layer and one aluminum oxide-hydroxide octahedral layer. See silicate clay.

KARST - An irregular limestone region with sinks, underground streams and caverns. Sites located in
karst topography, especially with clayey residual soils overlying limestone or dolomite with fracture and
solution porosity and  permeability have a  high potential for contaminants to reach ground water.

KNOWLEDGE BASE  (FRAME) - The knowledge base of an expert system that uses "expert"
information to solve a problem and reach  a conclusion. Features of a knowledge base consist of a
set of IF — THEN rules or other knowledge representation methods such as frames. Features are
described  in terms of objects and/or attributes. See also expert system,  inference engine,  knowledge-
based system tool.

KNOWLEDGE-BASED SYSTEM TOOL - A tool that provides underlying links and is ideal for providing
occasional access to  help screens, diagrams or data bases, and neural  nets (nodes) which use other
types of logic to solve problems; Hypertext is an example of a knowledge-based tool. See also expert
system, inference engine, knowledge base.

KROTOVINAS - Irregular, tubular streaks within one soil horizon consisting  of the soil materials
transported from another horizon; these streaks can result from the filling of tunnels made by
burrowing  animals, especially rodents.

LABILE - A substance that is readily transformed by microorganisms or  is readily available to plants.

LABORATORY WASTE - Discarded materials which have been generated by laboratory research,
processes, and analyses.

LAGOON - (i) A shallow channel or pond  near or communicating with a larger body of water, (ii) A
shallow artificial  pool for storing or processing a liquid.

LAND - A term commonly used to include the soil and surface features for a specified situation,
nature, or quality over an area considered as a unit, e.g., valley bottom land.

LAND DISPOSAL - Includes, but is not limited to, placement in a landfill, surface impoundment, waste
pile, injection well,  land treatment facility, salt dome formation, underground mine or cave, or concrete
vault or bunker intended for disposal  purposes.

LAND FARMING (of wastes) - A disposal process in which hazardous waste deposited on or in soil is
degraded naturally by microbial action. See disposal, degradation.
Guide to Site and Soil Description              B-31

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                                                                                  Appendix B
LANDFILL - A disposal facility or part of a facility where wastes are placed directly in or onto the
ground; not a land treatment facility, surface impoundment, or other surface repository.

LANDFILL CELL - A discrete portion of a hazardous waste landfill which uses some means (e.g., a
liner) of providing isolation of wastes from adjacent cells or wastes.

LANDFILL HAZARDS - Potential hazards from landfills to include contamination of surface and ground
waters, generation of toxic fumes, and human hazards from fires, explosions, and other events.

LANDFILLING - The covering of solid wastes in  a facility to minimize leachate formation; a technology
used for RCRA corrective action.

LANDFILLS - (i) Sanitary landfills are land disposal sites for non-hazardous solid wastes at which the
waste is spread in layers, compacted to the smallest practical volume, and cover material applied at
the end of each operating day. (ii) Secure chemical landfills are disposal sites for hazardous waste.
They are selected and designed to minimize the chance of release of hazardous substances into the
environment.

LANDFORM - A three-dimensional part of the land surface, formed of soil, sediment, or rock that is
distinctive because of its shape, that is significant for land use or to landscape genesis; that repeats in
various landscapes, and that also has a fairly consistent position relative to surrounding landforms.

LANDSCAPE - All the  natural features such as fields, hills, forests, water, etc., which distinguish one
part of the earth's surface from another part. Usually that portion of land or territory which  the eye can
comprehend in a single view, including all its natural characteristics.

LARGE ANIMALS - These include both wild and domestic animals that typically weigh more than 16.3
kg (30 pounds) when fully grown (sometimes called  mega-animals).

LAY OF THE  LAND - See topography.

LEACHATE -  A liquid that results when water collects contaminants as it trickles through wastes,
agricultural pesticides, or fertilizers. Leaching may  occur in farming areas, feedlots, and landfills, and
may result in  hazardous substances entering surface water, ground water, or soil.

LEACHATE SEEP - Leachate that emerges on the ground surface.

LEACHED - The condition of a soil which has experienced leaching. See leachate.

LEACHING FRACTION - The fraction of infiltration irrigation water that percolates below the root zone.
For waste sites, that fraction of infiltrate that percolates below the root (saturated) surface  layers of
soil.
Guide to Site and Soil Description             B-32

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                                                                                 Appendix B
LEACHING REQUIREMENT - The leaching fraction necessary to keep soil salinity, chloride, or sodium
(the choice being that which is most demanding) from exceeding a tolerance level of the crop in
question relevant to agriculture. For waste sites, the leaching requirements may satisfy other
requirements, such as in the removal of contaminants to remediate a site. It applies to steady-state or
long-term average conditions.

LEACHING - The dissolution and removal of substances or materials in solution from the soil by
movement (percolation)  of water through the soil.

LIGANDS - (i) A group of atoms, ions, or molecules bound to the central element (atom or ion), (ii)
The molecule or ion that contains the donor atom in a complex. See complexation.

LIGHT SOIL - An agricultural term used to describe a soil with a high content of sand.

LIMESTONE - See granular rock structure.

LIMITING FACTOR - A condition whose absence, or  excessive concentration, is incompatible with the
needs or tolerance of a species or population and which may have a negative influence on their ability
to grow or even survive.

LIMNIC MATERIALS - Classified As Organic Materials - Limnic materials include both organic and
inorganic materials that were either (1) deposited in water by precipitation or through the action of
aquatic organisms such as algae or diatoms, or (2) derived from underwater and floating aquatic
plants and subsequently modified by aquatic animals. They include coprogenous earth (sedimentary
peat), diatomaceous earth, and marl.

LINER - Commonly the material or continuous layer of natural or man-made materials used on the
inside or beneath the surface of an impoundment, landfill, or landfill cell to prevent or restrict the
downward or lateral movement or leaching of wastes, including hazardous waste constituents, to the
environment.

LIQUID CHEMICALS - A freely flowing substance, usually other than water, obtained by a  chemical
process or used for producing a chemical effect.

LIQUID LIMIT - The minimum water mass content at which a small sample will barely flow under
standard treatment. See Atterberg limits.

LIQUID WASTE - Water or liquid chemicals rejected after usage in communities, industry, agriculture,
in other enterprises or processes.  See wastewater.

LISTED WASTE - (i) A solid waste considered hazardous under 40 CFR 261 Subpart D. A  listed waste
comes from a process found to generate a hazardous waste or is a commercial chemical product that
has been discarded, (ii)  A  hazardous waste under RCRA but which has not been subjected to the
Guide to Site and Soil Description             B-33

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                                                                                 Appendix B
Toxic Characteristics Listing Process because the dangers they present are considered self-evident.
See also characteristic waste and delisting.

LITTER  - The surface layer (of a forest floor) consisting of the additions of freshly fallen leaves, twigs,
stems, flowers, fruits and bark.

LOAM - An intermediate soil texture class; loamy includes all texture classes with the words loam or
loamy as part of its class name, e.g., clay loam or loamy sand.  See soil texture.

LOESS  - Material transported and deposited by wind and consisting of predominantly silt-sized
particles.

LOSS/DECAY - The degradation of chemicals resulting in a reduction  in the concentration of
contaminants (in soil or ground water).

LOW HAZARD WASTES - Those wastes of such low combustibility that no self-propagating fire can
occur.

LOW-LEVEL RADIOACTIVE WASTE - (i) Wastes less hazardous than  most of those generated by a
nuclear  reactor. Usually generated by hospitals, research laboratories, and certain  industries.  The
Department of Energy, Nuclear Regulatory Commission,  and EPA share responsibilities for managing
them; (ii) Defined by law as waste that is not classified as high-level waste, transuranic waste (in
excess of 10 nCi/g), uranium mine and mill tailings, or spent nuclear fuels.  Also compare with
high-level radioactive waste.

MACROBIOTA - See soil macrofauna.

MACRO CATIONS - Major cation constituents of uncontaminated soils, including calcium,  magnesium,
sodium  and potassium.

MACRONUTRIENT - A plant nutrient attaining a concentration of >500 mg kg"1 in  mature plants.
Usually  refers to nitrogen, phosphorus, potassium, calcium,  magnesium and sulfur. Compare with
micronutrients.

MAP UNIT - See soil map unit.

MARSH - Periodically wet or continually flooded areas with the surface not deeply  submerged.
Covered dominantly with sedges, cattails, rushes, or other hydrophytic plants. Subclasses include
fresh-water and salt-water marshes. See swamp.

MATRIC SUCTION - See soil water matric potential.
Guide to Site and Soil Description              B-34

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                                                                                Appendix B
MATURE SOIL - A soil with well-developed characteristics produced by the natural processes of soil
formation, and in equilibrium with its environment.

MEDIA - Specific environments - air, water, soil - which are the subject of regulatory concern and
activities.

MEDIUM TEXTURED SOIL - A soil with textural properties intermediate between those of heavy and
light soils, e.g., very fine sandy loam, loam, silt loam, and silt.  See soil texture.

MESOBIOTA - See soil mesofauna.

METABOLISM - The totality of the processes by which an organism uses food for production of its
protoplasm, energy production, storage, or elimination as waste. Also see recalcitrant molecule.

METAL CLEANING WASTE - Any wastewater resulting from the cleaning of any metal process
cleaning equipment.

METAL SPECIES - A metal entity or metal molecular particle, such as a metal ion. See ionic species.

METAL/CYANIDE WASTE DISPOSAL RESTRICTIONS - Any liquid containing wastes which exceed
the specified concentrations of total metals or cyanides in their leachate in  accordance with Code 40
CFR Part 261.

METALS - Elements which form positive ions when their salts are dissolved in water.

METALLOID - (i) A nonmetallic element, such as carbon or nitrogen, which can combine with a metal
to form an alloy. See semiconductors, (ii) An element resembling a metal, such as boron and
selenium.

METEOROLOGY - The science concerned with the atmosphere and its phenomena, i.e., temperature,
density, winds, clouds,  humidity, pressure, movement and other characteristics.

MICROAEROPHILIC MICROORGANISM - A microorganism that requires a low concentration of
oxygen for growth. Sometimes used to indicate a microorganism that will carry out its metabolic
activities under aerobic conditions but that will grow much better under anaerobic conditions.

MICROBIOTA - See soil microbiota.

MICROCLIMATE - (i) The climatic condition of a small area resulting from the modification of the
general climatic conditions by local differences in elevation  or exposure, (ii) The sequence of
atmospheric  changes within a very small region.
Guide to Site and Soil Description              B-35

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                                                                                  Appendix B
MICROFAUNA - Protozoa, nematodes, and arthropods of microscopic size. See protozoa, nematodes
and arthropods.

MICROFLORA - (i) Bacteria, including actinomycetes and streptomycetes, fungi (yeasts and molds),
myxomycetes, algae, including cyanobacteria, and viruses. See bacteria, actinomycetes,
streptomycetes, fungi (yeasts and molds), cyanobacteria (blue-green algae) and viruses, (ii) A small or
strictly localized flora.

MICROHABITAT - See soil microhabitat.

MICRONUTRIENT - A chemical element necessary for plant growth found in small amounts, usually <
100 mg kg"1 in the plant. These elements consist of boron, chloride, copper, iron, manganese,
molybdenum and zinc. Compare with macronutrient.

MICROORGANISMS - See microbiota.

MICRORELIEF - (i) Small  scale, local differences in topography, including mounds, swales, or hills
that are usually  <  1  m in diameter and with elevation difference of up to 2 m. (ii) Differences in
topography altered by tillage operations, generally over an area of about 1  m2 with elevation
differences of a few centimeters or less. See relief.

MICROSITE - A small volume of soil where  biological or chemical processes differ from those of the
soil as a whole,  such as an anaerobic microsite of a soil aggregate or the surface of decaying organic
residues. Microsites may be evident at waste sites, especially if waste is unevenly distributed. Also see
soil microhabitat.

MILITARY WASTES - The wastes resulting from industrial manufacture  of military items or materials, or
resulting from military operations,  usage, or storage, including hazardous wastes, munitions,
explosives, inflammables,  biological, and chemical warfare agents.

MINE DUMPS - (Note: obsolete.) Areas covered with overburden and other waste materials from ore
and coal mines, quarries and smelters and  usually with little or no vegetative cover. A miscellaneous
area. See  miscellaneous areas.

MINERAL - A naturally occurring substance with a solid,  homogeneous crystalline chemical structure,
occurring as individual crystals or disseminated in some other mineral or rock. Also see soil mineral.

MINERAL SOILS - (i) Soils consisting predominantly of, and having its properties determined
predominantly by, mineral matter. Usually contains < 200 g kg"1 organic carbon (< 120-180 g kg"1  if
saturated with water), but  may contain an organic surface layer up  to 30 cm thick; (ii)  Soils that meet
one of the following requirements: (a) Mineral soil material less than 2.0 mm in diameter (the fine-earth
fraction) makes up more than half the thickness of the upper 80 cm (31 in.); or (b) The depth to
bedrock is less than 40 cm and the layer or layers of mineral soil directly above the rock either are 10
Guide to Site and Soil Description              B-36

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                                                                                  Appendix B
cm or more thick or have half or more of the thickness of the overlying organic soil material; or (c) The
depth to bedrock is 40 cm or more, the mineral soil material immediately above the bedrock is 10 cm
or more thick. (See USDA Soil Survey Staff, 1990. Keys to Soil Taxonomy, SMSS Tech. Monogr. No.
19, for further details.)

MINING WASTES - Any waste or residues resulting from mining operations and the extractions of raw
materials from the earth.  (Considered by Soil Science Society of America Glossary as a "miscellaneous
area.") See miscellaneous areas.

MINOR  ELEMENTS - See micronutrients.

MISCELLANEOUS AREAS - A Soil Science Society of American Glossary term  used for naming areas
of limiting conditions, e.g., dumps, wastes, etc. A kind of map unit used in soil surveys comprised of
delineations, each of which shows the size, shape and location of a landscape unit within which little
or no vegetation occurs because there either is little or no soil, there are very unfavorable soil
conditions,  there is active erosion, washing by water, or man's activities prevent vegetation growth.
See delineation and soil map unit.

MISCELLANEOUS UNIT - A hazardous waste management unit where hazardous waste is treated,
stored, or disposed  of and that is not a container, tank surface impoundment, pile, land treatment unit,
landfill, incinerator,  boiler, industrial furnace, underground injection well with appropriate technical
standards under 40 CFR 146, or unit eligible for a research, development, and demonstration permit
under §270.65.

MITES - Any of numerous minute or small  arachnids (four pairs of thoracic appendages) that infest
animals, plants, and stored foods; includes many disease vectors. See soil mesofauna, arachnids.

MIXED WASTE - Low-level radioactive waste (defined under the Low Level Radioactive Waste Policy
Amendments Act of 1985),  containing either a listed hazardous waste or a waste exhibiting hazardous
waste characteristics. Mixed waste must be managed in compliance with applicable RCRA, Atomic
Energy Act, and state regulations. Examples of mixed waste include lead oxide dross mixed with
uranium oxides.and  radionuclide-contaminated waste solvents from industry, academic institutions,
and medical facilities.

MIXING  RATE - The rate at which infiltrate  and medium, e.g., soil or ground water, are combined.

MOISTURE (WATER) CONDITIONS - The degree or extent to which a soil holds moisture and is
affected  by  its moisture potential and content, either long- or short-term. Also see soil water (moisture)
potential.

MOLDS  - A superficial, often woolly-type growth (of mycelia) produced on damp or decaying organic
matter or living organisms. A fungus, particularly of the order Mucorales, that produces mold.
Guide to Site and Soil Description              B-37

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                                                                                 Appendix B


MONITORING - The systematic detection and measurement of the physical, chemical, biological and
other components that interact in an ecosystem.

MONITORING SURVEY, Superfund - A survey made during initial entry to the site for a preliminary
evaluation of atmospheric hazards; a surveillance monitoring program of materials detected during the
initial site survey needing more comprehensive evaluation of hazards and analyses for specific
components; a program established to monitor sampling and evaluate hazards for the duration of site
operations; a continuous monitoring of atmospheric changes since site activities and weather
conditions may change during site investigations.

MONTMORILLONITE - An alluminosilicate clay with a 2:1  expanding crystal lattice. See  silicate clay.

MOST PROBABLE NUMBER - The estimation of a microbial population or density without an actual
count of single cells or colonies; a dilution method of estimated population sizes based on the highest
dilution at which growth can be obtained.

MOTTLE - A spot, blotch or patch of color or shade of color, occurring on the surface of a sediment
or soil.

MOTTLED SOIL - A soil with spots or blotches of different color or shades of color interspersed with
the dominant color, usually indicating poor aeration or seasonal wetness. May be indicative of
restrictive drainage or chemical accumulations in hazardous waste sites.

MUCK SOIL - (i) A soil containing between 200 and 500 g kg"1 of organic matter, (ii) An organic soil in
which the plant residues have been altered beyond recognition, (iii)  Dark, finely divided,  well-
decomposed organic material intermixed with a high percentage of mineral matter, usually silt.

MUNSELL COLOR SYSTEM - A color designation system applied to soils that specifies the relative
degrees of the three simple variables of color:  hue, value, and chroma. See Munsell Soil Color Chart.

MUNSELL SOIL COLOR CHART - An assemblage of appropriate color chips in the pages  of a  loose-
leaf notebook by which soil colors can be matched and identified in a standardized fashion. See
Munsell Color System.

MYCELIUM - A network of hyphae. See hypha and molds.

MYCORRHIZA - The association, usually symbiotic, obligatory or  beneficial, of specific fungi with the
roots of higher plants.

MYXOMYCETES - Plasmodial, or acellular, true slime molds with characteristics intermediate between
the protozoa and fungi; a class of microorganisms of the division  Mycota. Found especially in soils
rich in organic matter.
Guide to Site and Soil Description              B-38

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                                                                                  Appendix B
NATURAL AREA - An area of land in which organisms, soils, geology, and related processes are
undisturbed by man,  and with as few controls as possible.

NATURAL HAZARDS - Detrimental occurrences brought about by the forces of nature such as floods,
hurricanes, earth movements, wildfires, and volcanos. These hazardous can also be accelerated by
human and/or animal activity to include erosion, acid precipitation and climate change, as well as
flooding.

NATURAL LAND VEGETATION - Vegetation which uses soil as its growth medium, and which is not
subject to extensive cultural practices.  Included are naturally-occurring plants  such as trees, shrubs,
grasses, herbs, forbs, ferns, lichens, and algal-lichen soil crusts.

NEMATODE - Elongated, minute, cylindrical worms parasitic in animals or plants or fee-living; any of a
class or phylum Nematoda. See microfauna.

NEUTRALIZATION - Decreasing the acidity of alkalinity of a substance by adding it to alkaline or acid
materials, respectively. See hazardous waste treatment.

NEUTRAL SOIL - A soil in which the surface layer, at least in the agricultural sense of the tillage zone,
is the range pH 6.6 -  7.3. (Not a strict chemical definition of pH=7.0) See soil reaction.

NICHE - (i) The particular role that a given species plays in the ecosystem; (ii)  the physical space
occupied by an organism (including microorganisms).

NITRATE -  (i) Salt or  ester of nitric acid, (ii) To treat of combine with nitric acid or a nitrate.

NONHUMIC SUBSTANCES - The organic substances of low molecular weight, such as organic acids
and gases, that are relatively soluble in the soil water when complexed with metals. Compare with
humic substances.

NONMETALS - Elements that are ordinarily very poor conductors of electricity; their atoms have high
electron affinities; high ionization energies; and, tend to form simple monatomic anions of noble gas
configuration by acquiring electrons from metal atoms. They may react with each other.
Representatives include hydrogen, carbon, nitrogen,  phosphorus, oxygen, sulfur, fluorine, chlorine,
bromine, iodine, astatine, and the noble gases: helium, neon, argon, krypton, xenon, and radon. All
are found in the atmosphere except radon, which is radioactive. Only the noble gases are monatomic.
Carbon and sulfur can be found in pure elemental forms in nature. All of the other nonmetals are too
reactive to remain uncombined and occur naturally only in compounds.

NON-POINT SOURCE - Pollution sources which are  diffuse and do not have a single point of origin or
are not introduced into a receiving stream from a specific outlet. The pollutants are generally carried
off the land by stormwater runoff. The commonly used categories for non-point sources are:
Guide to Site and Soil Description              B-39

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                                                                                Appendix B
agriculture, forestry, urban, mining, construction, dams and channels, land disposal, and saltwater
intrusion. Compare with point source.

NONINDUSTRIAL WASTES  - Any wastes other than from industrial sources.

NONSPECIFIC HAZARDOUS WASTE SOURCES - Waste not generated from manufacturing
processes, such as wastewater treatment sludges from chemical conversions, e.g., coating of
aluminum; and spent halogenated solvents used  in degreasing, e.g., carbon tetrachloride, chlorinated
fluorocarbons, methylene chloride, tetrachloroethylene, trichloroethylene, and 1,1,1-trichloroethane.

NUCLEAR WASTE - Radioactive waste resulting from human activity and classified into four
categories depending upon (1) origin, (2) level of radioactivity, and (3) potential hazard:  high level
waste; low level waste; transuranic waste; and tailings.

NUTRIENT STRESS - A condition occurring when inadequate nutrient supply restricts growth. See
macronutrient, micronutrient, soil nutrient diffusion.

ODOR - The quality or character of the smell of the soil, especially when dislodged for olfactory
examination.

ODOR THRESHOLDS - The lowest concentration of a contaminant that can be detected by odor.

OFF-SITE FACILITY - A hazardous waste treatment, storage, or disposal area that is located at a
place away from the generating site.

OIL DUMPING - Usually intentional discharge of oil or oily wastes onto or within an aqueous or
terrestrial surface.

OIL WASTELAND - Land on which oily wastes have accumulated, including slush pits and adjacent
areas affected by oil waste. (Considered by Soil Science Society of America, Glossary  of Soil Science
Terms, as a "miscellaneous area.") See miscellaneous area.

ON-SITE FACILITY - A hazardous waste treatment, storage, or disposal area that is located on the
generating site.

ON-SCENE COORDINATOR (OSC), Superfund - The predesignated EPA, Coast Guard, or
Department of Defense official who coordinates and directs Superfund removal actions or Clean Water
Act oil-or hazardous-spill corrective actions.

ON-SITE INVESTIGATION, PRELIMINARY, Superfund - An initial onsite survey to determine, on a
preliminary basis, hazardous or  potentially hazardous conditions.
Guide to Site and Soil Description             B-40

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                                                                                Appendix B
ON-SITE PROPERTY - Geographically contiguous property which may be divided by public or private
right-of-way, provided the entrance and exit between the properties is at a crossroads intersection,
and access is by crossing, as opposed to going along the right-of-way. Noncontiguous properties
owned by the same person but connected by a right-of-way, which that person controls and to which
the public does not have access, are also considered on-site property.

OPEN DUMP - (i) Any facility or site where solid waste is disposed of which is not a sanitary landfill
that meets the criteria promulgated under section 4004 of RCRA and is not a facility for disposal of
hazardous waste. (All open dumps will eventually be prohibited by RCRA.) (ii) A site where solid waste
is deposited on a land surface with little or no treatment. See dumps.

OPEN LAND - Any surface or subsurface land which is not a disposal site and is not covered by a
building.

OPEN SPACE - Land predominately free of buildings, and sometimes protected from development;
excludes land used for traffic ways, railroads, and parking lots.

OPERABLE UNIT - Term for each of a number of separate activities undertaken as part of a
Superfund site cleanup.  A typical operable unit would be removing drums and tanks from the surface
of a site.

ORGANIC CHEMICALS/COMPOUNDS - (i) Animal- or plant-produced substances containing mainly
carbon, hydrogen and oxygen, (ii) In a hazardous waste site,  may include those which are hazardous
or toxic, such as pesticides.

ORGANIC COMPLEXATION - A process in which a metal ion is bound to nonmetal  atoms (e.g.,
nitrogen,  carbon, or oxygen) to form a heterocyclic ring having coordinate covalent bonds. See
inorganic complexation and chelates; covalent  bonding.

ORGANIC MATTER - Material of plant or animal origin that decays in the soil to form humus. See
humus.

ORGANIC RESIDUES - Animal and vegetative material added to the soil and which  are recognizable
as to their origin.

ORGANIC SOIL - A soil which contains a high percentage (> 200 g kg'1 or > 120-180 g kg1 if
saturated with water) of organic carbon throughout the upper and most weathered part of the soil
profile.

ORGANIC SOIL MATERIALS (AND ORGANIC SOILS) -  (i) Are saturated with water for long periods
or are artificially  drained and, excluding live roots, (a) have 18 percent or more organic carbon if the
mineral fraction is 60 percent or more clay, (b)  have 12 percent or more organic carbon if the mineral
fraction has no clay, or (c) have a  proportional  content of organic carbon between 12 and 18 percent
Guide to Site and Soil Description             B-41

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                                                                               Appendix B
if the clay content of the mineral fraction is between zero and 60 percent; or (ii) Are never saturated
with water for more than a few days and have 20 percent or more organic carbon. Three basic kinds
of organic soil materials are distinguished, fibric, hemic and sapric, according to the degree of
decomposition of the original plant materials. See fibric, hemic, and sapric soil materials. Also see
USDA Soil Survey Staff, 1990, Key to Soil Taxonomy, SMSS Tech. Monogr. No. 19, for details.

ORGANIC SOIL MATERIALS, HIGHLY DECOMPOSED - The most highly decomposed of the organic
soil materials. Rubbed fiber content is < 17 percent of the volume.

ORGANIC WASTE DIGESTIBILITY - The potential degree to which organic matter in waste water or
sewage can be broken down into simpler and/or more biologically stable products.

ORGANOMETALLIC COMPLEX - An organic-metal complex, e.g., a humus-metal complex. See
complex.

ORGANOMETALLIC COMPOUND - Molecules  containing carbon-metal linkage.

ORGANO-METAL CHELATE - A chelate formed by an organic component (organic molecule) and a
metal. Also see chelate.

OVEN-DRY SOIL - Soil that has been dried at 105 °C until it reaches constant weight (usually 24
hours).

OVERBURDEN - A general term referring to all  the unconsolidated rock debris overlying the  bedrock.
Engineers sometimes use the terms overburden and soil interchangeably. Geologists commonly infer
that "soil" is the upper few feet of overburden that has been obviously weathered and is often divisible
into secondary zones of variable color or texture.

OXIDATION - Any process in which oxidation number (the positive or negative character of atoms in
compounds)  increases algebraically.

OXIDES - Binary compounds with oxygen. All metals form normal oxides with oxygen in its most
common oxidation  state of -2. Common oxides  in soil include silicon, aluminum,  iron and manganese.
The alkali and alkaline earth metals also form stable compounds with anions containing two or three
oxygen atoms in lower negative oxidation states, two of which are fractional. Manganese and iron
oxides may be very important in retarding the migration of pollutants in soil systems.

PANS - Horizons or layers in soils, that are strongly compacted, indurated, or very high in clay content
or other cementing minerals or  chemicals.

PARENT MATERIAL (OF SOILS)  - Unconsolidated, more or less chemically weathered mineral matter
from which soils are formed.
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                                                                                 Appendix B
PARTICLE SIZE - The effective diameter of a particle measured by sieving, sedimentation, or
micrometric methods.

PARTICLE-SIZE CLASSES - The grain-size distribution of the whole soil; not the same as texture,
which refers to the fine earth fraction, consisting of particles of < 2.0 mm diameter. Particle-size
classes are a kind of compromise between engineering and pedologic (soil) classifications.

PARTICLE-SIZE DISTRIBUTION - The amounts of the various soil separates in a soil sample
expressed as percentages by weight.

PATHOGENS - Microorganisms that can cause disease in other organisms or in humans, animals,
and plants. They may be bacteria, viruses, or parasites and are found in sewage, in runoff from animal
farms or rural areas  populated with domestic and/or wild animals, and in water used for swimming.
Fish and shellfish contaminated by pathogens, or the contaminated water itself, can cause serious
illnesses.

PED - An individual natural soil aggregate such as a crumb, prism or block, in contrast to a clod,
which results  from digging or other soil disturbance. See crumb, prism, block, clod.

PEDOLOGICAL FEATURES - Recognizable units within a soil material which are distinguishable from
the enclosing material for any reason such as origin (deposition as an entity), differences in
concentration of some fraction of the plasma, or differences in arrangement of the constituents
(fabric).

PEDON - A three-dimensional body of soil with lateral dimensions large enough to permit the study of
horizon shapes and  relations. Its area ranges from 1 to 10 square meters. Where horizons are
intermittent or cyclic, and recur at linear intervals of 2 to 7 m, the pedon includes one-half of the cycle.
Where the cycle is < 2 m, or all horizons are continuous and of uniform thickness, the pedon has an
area of approximately 1 square meter. If the horizons are cyclic, but recur at intervals >  7 m, the
pedon reverts to the 1  square meter size, and more than one soil will usually be represented in each
cycle.

PENETRABILITY - The ease with which a probe can be pushed into the soil. (May be expressed in
units of distance, speed, force, or work depending on the type of penetrometer used.) Chemical
wastes may alter soil penetrability.

PENETROMETER - A device used to determine soil hardness, particularly the soil surface. Penetration
units are measured in Ib/in2 or kg/cm2.

PERCHED WATER - Ground water that is not confined and is separated from an underlying main
body of ground water by an  unsaturated zone.

PERCHED WATER TABLE - The apparent water table or upper surface of a body of perched water.
Guide to Site and Soil Description              B-43

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                                                                                 Appendix B
PERCOLATION, SOIL WATER - The downward movement of water through soil and radially through
the sub-surface soil layers, usually continuing downward to the ground water. Especially, the
downward flow of water in saturated or nearly saturated soil at hydraulic gradients of the order of 1.0
or less. See hydraulic gradient.

PERMAFROST - A soil layer in which the temperature is perennially at or below 0°C, whether the
consistence is very hard or loose. Dry permafrost has loose consistence.

PERMANENT WILTING POINT - The largest water content of a soil at which indicator plants, growing
in that soil, wilt and fail to recover when placed in a humid chamber. Often estimated by the water
content at -1.5 MPa soil matric potential (15 bar water.) 1 MPa (megapascal) =  10 bars (atmosphere).
Also see soil water matric potential.

PERMEABILITY - The rate at which liquids pass through soil or other materials  in specified direction.

PERMEABILITY COEFFICIENT - See hydraulic conductivity.

PERMIT - An authorization, license, or equivalent control document issued by EPA or an approved
state agency to implement the requirements of an environmental regulation; e.g., a permit to operate a
wastewater treatment plant or to operate a facility that may generate harmful emissions.

PERSISTENCE - Refers to the length of time a compound, once introduced into the environment,
stays there. A compound may persist for less than  a second or indefinitely.

PERTURBED SOILS - Soils that have been contaminated or polluted and that have received
undesirable elements or materials from an external source not endemic to the soil system.

PESTICIDE - Any chemical substance or compound,  or mixture of these, applied to plants, soils,
seeds, water, food or other contact point for the purpose of preventing, inhibiting, repelling, mitigating
or destroying pests.  Can also include plant regulators, defoliants or desiccants derived from mineral
substance. Pesticides are named according to their intended control purposes: algicides,
bactericides, fungicides, herbicides,  insecticides, molluscicides, nematocides, ovicides, rodenticides,
and vivucides.

pH - See soil reaction (pH).

PHASE - The homogenous part of a system in contact with, but separate from  other parts  of the
system.

PHOSPHATES - (i) A salt or ester of a phosphoric  acid (H3P04). (ii) An organic compound of H3P04 in
which the acid group is bound to nitrogen or a carboxyl group in a way that permits  useful energy to
be released (as in metabolism), (iii) The trivalent anion PO4 derived from H3P04.
Guide to Site and Soil Description              B-44

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                                                                                 Appendix B


PHOTODEGRADATION - Decomposition of a compound by radiant energy. See degradation.

PHYLLOSILICATE MINERAL TERMINOLOGY - Phyllosilicate minerals have layer structures
composed of shared octahedral and tetrahedral sheets.

PIEZOMETER  - An instrument for measuring pressure or compressibility, especially one for measuring
the change of pressure of a material subjected to hydrostatic pressure. Also see hydraulic head and
tensiometer.

PITS - Open excavations from which soil and, commonly, underlying material have been removed,
exposing either rock or other material that supports few or  no plants. Soil pits are commonly
excavated to reveal the soil profile and for collection of depth samples of soil.  See soil profile.

PLANT ANALYSIS - Analytical procedures to usually determine the nutrients of plants or plant parts.
See foliar analysis and foliar diagnosis.

PLANT TYPE - The kind of vegetation, e.g.,  grasses,  shrubs, herbs, forbs, trees, etc. or more exactly,
the genus, species and possible variety of plant.

PLASTIC LIMIT - The minimum water mass  content at which a small sample of soil or soil material
can be deformed without rupture. See Atterberg limits.

PLASTIC SOIL - A soil capable of being molded or deformed continuously and permanently, by
relatively moderate pressure, into various shapes. See consistency.

PLATE (PLATEY)  - A unit, type or class of soil structure with plate-like aggregates. See aggregates.

PLASMA - See soil plasma.

PLATE COUNT - A count of the number of colonies formed on a solid culture medium when
inoculated with a small amount of soil. The technique is used to estimate the number of certain
organisms present in the soil sample.

PLINTHITE - A nonindurated mixture of iron and aluminum oxides, clay, quartz, and other diluents that
commonly occurs  as red soil mottles usually arranged in platy, polygonal, or reticulate patterns.
Plinthite changes irreversibly to ironstone hardpans or irregular aggregates on exposure to repeated
wetting and drying.

PLUME  - (i) A visible or measurable discharge of a contaminant from a given point of origin;  can be
visible or thermal in water, or visible in the air as, for example, a plume  of smoke, (ii) The area of
measurable and potentially harmful radiation leaking from a damaged reactor,  (iii) The distance from  a
toxic release considered dangerous for those exposed to the leaking fumes.
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                                                                                  Appendix B
POINT SOURCE - A stationery location or fixed facility from which pollutants are discharged or
emitted. Also, any single identifiable source of pollution, e.g., a pipe, ditch, ship, ore pit, factory
smokestack. Compare with non-point source.

POISED SOIL SYSTEM - A soil system that is buffered against potential changes such as when
subjected to external effects, e.g., waterlogging or the addition of waste materials and other
contaminants. A system which has a stabilized redox potential is said to be "well-poised." See redox
potential.

POLLUTANT - Generally, any substance introduced into the environment that adversely affects the
usefulness of a resource.

POLLUTANT PERSISTENCE - The retention by certain pollutants of their toxic strength for periods
varying from hours, as for certain bacteria, or for thousands of years, as for some radioactive
materials; also, resistance to dilution, removal, elimination, or biodegradation by organisms or in
media.

POLLUTANTS, CONVENTIONAL - Statutory listed pollutants which are understood well by scientists.
These may be in the form of organic wastes, sediments, acids, bacteria and viruses, nutrients, oil and
grease, or heat.

POLLUTION - The impairment of the quality of some portion of the environment by the addition of or
subjection to harmful impurities, substances, or materials.

POLLUTION PREVENTION - Any source reduction or recycling activity that results in reduction of
total volume of hazardous waste, reduction of toxicity of hazardous waste, or both, as long as that
reduction is consistent with the goal of minimizing present and future risks to public health and the
environment.

POLYGONS - In  geology, a ground surface consisting of polygonal (i.e., a closed plane figure bound
by straight lines)  arrangement of rock, soil and vegetation formed on a level or gently sloping surface
by the action of frost. See fragipan.

POLYPEDON - A group  of contiguous similar pedons. The limits of a polypedon are reached at a
place where there is no soil or where the pedons have characteristics that differ significantly. Also see
pedon and soil series.

POLYVINYL CHLORIDE (PVC) - A tough, environmentally indestructible plastic that releases
hydrochloric acid when burned.

POND - A still body of water smaller than a lake,  often of artificial construction.
Guide to Site and Soil Description             B-46

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                                                                                Appendix B
POPULATION - A group of interbreeding organisms of the same kind occupying a particular space.
Generically, the number of humans or other living creatures in a designated area

PORE - See soil pore, porosity.

PORE GEOMETRY - The configuration and shape of the soil pores (voids).

POROSITY - The volume percentage of the total bulk of soil not occupied by solid particles.

POTENTIALLY RESPONSIBLE PARTY (PRP), Superfund - Any individual or company - including
owners, operators, transporters, or generators - potentially responsible for, or contributing to, the
contamination problems at a Superfund site. Whenever possible, EPA requires PRPs, through actions,
to clean up hazardous waste sites PRPs have contaminated.

PPM/PPB - Parts per million/parts per billion, a way of expressing tiny concentrations of pollutants in
air, water, soil, human tissue, food, or other products.

PRECIPITATION, CHEMICAL - (i) The process of producing a separable condensed (solid) phase
within a liquid medium as a result of slow chemical reaction, (ii) Removal of solids from liquid waste;
removal of particles from airborne emissions. Compare with precipitation, meteoric.

PRECIPITATION (METEORIC) - (i) Atmospheric precipitation, (ii) Usually rainfall, but includes all forms
of precipitation of atmospheric moisture, e.g., ice, snow, etc. Three types of rainfall are generally
recognized depending upon differences in air temperature, density, pressure, and movement.

PRELIMINARY ASSESSMENT - The process of collecting and reviewing available information about a
known or suspected waste site or release.

PRESSURE HEAD - The height to which water will rise above the bottom of a vertical, open-ended
tube inserted to a point where the pressure head is to be measured.

PREVENTION - Measures taken to minimize the release of wastes to the environment.

PRIORITY POLLUTANTS - A list of toxic pollutants for which the EPA is required to publish effluent
standards under Sec 307 of the Clean Water Act of 1977.

PRISM (PRISMATIC) - A unit type or class of soil structure with prismatic-like aggregates. See
aggregates, ped.

PRODUCTIVE SOIL - A soil in which the chemical, physical, and biological conditions are favorable
for the economic production of crops suited to a particular area. Also see fertile soil.
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                                                                                Appendix B
PROJECT DESCRIPTION, Superfund - Defines the goals of the project and describes how the
information necessary to meet the project goals will be obtained. The project description should
provide enough information to judge the appropriateness and adequacy of the quality assurance,
work, or sampling plans. See US EPA, 1987, A Compendium of Superfund Field Operations Methods,
EPA/540/P-87/001, for further details.

PROTOZOA - Minute or microscopic protoplasmic acellular or unicellular animals with varied
morphology and physiology and often complex life cycles, found in almost every kind of habitat;  any
member of the phylum or subkingdom Protozoa. See microfauna.

PUDDLED SOIL - A soil that is dense, massive and artificially compacted when wet and has no
regular structure. The condition commonly results when the  soil is manipulated (tilled) when a clayey
soil is wet.

QUALITY ASSURANCE PROJECT PLAN (QAPjP), Superfund - The policies, organization, objectives,
functional activities, and specific QA and Quality Control (QC) activities designed to achieve the data
quality goals of the specific project(s) or continuing operation(s).

QUALITY ASSURANCE/QUALITY CONTROL (QA/QC) - A system of procedures, checks, audits, and
corrective actions to ensure that all EPA research design and performance, environmental monitoring
and sampling, and other technical and reporting activities are of the highest achievable quality.

QUARTZITE - See granular rock structure.

RADIATION -  Any form of energy propagated as rays, waves, or streams of energetic particles. The
term is frequently used in relation to the emission of rays from the nucleus of an atom.

RADIOACTIVE SUBSTANCES - Substances that  emit radiation.

RADIOACTIVE TAILINGS - Radioactive rock and  soil which  are the by-products of uranium mining
and milling; they principally contain small amounts of radium which decays to emit radon, a
radioactive gas.

RADIOACTIVE WASTES  - Waste materials and substances  from industry or institutions (including
nuclear power plants and uranium mines and mills) that spontaneously emit alpha or beta rays and
sometimes gamma rays.  Radioactive waste material can also be gaseous as well as liquid and solid.

RCRA - Resource Conservation and Recovery Act. Enacted in 1976 as an amendment to the Solid
Waste Disposal Act (SWDA). The primary objectives of the Act are to protect human health and the
environment, and to conserve valuable material and energy  resources. RCRA concentrates on active,
controlled solid waste facilities. Compare with CERCLA. See Solid Waste Disposal Act.
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                                                                                Appendix B
REACTIVE HAZARDOUS WASTE - Waste that may react spontaneously, react violently with water, or
that may generate toxic fumes when mixed with water or exposed to basic or mild acidic conditions.

RECALCITRANT MOLECULES - Molecules that persist in the environment and are resistant to
degradation by physical (e.g., ultraviolet light), chemical (e.g., hydrolysis, oxidation/reduction) or
biological (e.g., metabolism) factors.

RECONSTRUCTED SOILS - Disturbed soils, or unconsolidated geologic materials of soil size
fractions, that are replaced in a vertical sequence of such quality and thickness that they provide a
favorable medium for plant growth or other desirable purpose.

RECYCLABLE MATERIALS,  Superfund - Hazardous wastes reclaimed to recover a usable product.
The generation, transportation, and storage of recyclable materials are subject to RCRA requirements
under CFR Parts 262, 263, and 264.

RECYCLABLE WASTES - See recyclable materials.

REDOX POTENTIAL (Eh) - The potential that is generated between an oxidation or  reduction half-
reaction and the hydrogen electrode in the standard state. See soil redox potential.

REDOX REACTIONS - Oxidation-reduction reactions; reactions in which oxidation and reduction occur
together.

REDUCTION - Any process in which oxidation number (the positive or negative character of atoms in
compounds) decreases algebraically.

REFUSE - A term generally used for all solid waste substances and materials.

REGIONAL PROJECT  (PROGRAM) OFFICER (RPO), Superfund - The EPA individual who oversees
implementation of a program at the EPA regional level; a Project Officer at EPA Headquarters is
responsible for program guidance agency-wide.

REGIONAL RESPONSE TEAM (RRT), Superfund - Representatives of federal, local, and state
agencies who may assist in coordination of activities at the request of the On-Scene Coordinator
before and during a Superfund response action.

RELATIVE HUMIDITY - The amount of water vapor the air is holding expressed as a percentage of
the amount the air could hold at that particular temperature.

RELIEF - Refers to elevations or differences in elevations, considered collectively, of a land surface on
a broad scale. Also see microrelief.
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                                                                                Appendix B
REMEDIAL INVESTIGATION - An in-depth study designed to gather the data necessary to determine
the nature and extent of contamination at a Superfund site; establish criteria for cleaning up the site;
identify preliminary alternatives for remedial actions; and support the technical and cost analyses of
the alternatives. The remedial investigation is usually done with the feasibility study. Together they are
usually referred to as the "RI/FS."

REMEDIAL PROJECT MANAGER (RPM) - The EPA or state official responsible for overseeing
remedial action at a site.

REMEDIAL RESPONSE - A long-term action that stops or substantially reduces a release or threat of
a release of hazardous substances that is serious but not an immediate threat to public health.

REMEDIATION - A measure or solution that resolves a particular problem of a contaminated site
(such as for site cleanup).

REMOTE SENSING - In the broadest sense, the measurement or acquisition of information of some
property of an  object or phenomenon, by a recording device that is not in physical or intimate contact
with the object or phenomenon under study; e.g., the utilization at a distance (as from aircraft,
spacecraft, or ship) of any device and its attendant display for gathering information pertinent to the
environment, such as measurements of force fields, electromagnetic radiation, or acoustic energy.

REMOVAL ACTION  - Short-term  immediate actions taken to address releases of hazardous
substances that require expedited response. See cleanup.

REPORTABLE QUANTITY (RQ) - The quantity of a hazardous substance that triggers reports under
CERCLA. If a substance is released in amounts exceeding its RQ,  the release must be reported to the
National Response Center, the State Emergency Response Commission, and community emergency
coordinators for areas likely to be affected. See CERCLA.

RESISTANCE  - For plants and animals, the ability to withstand poor environmental conditions and/or
attacks by chemicals or disease.  The ability may be  inborn or developed. See ecological amplitude,
tolerance.

RESPONSE ACTION - A CERCLA-authorized action involving either a short-term removal  action or a
long-term removal response that  may include but is not limited to:  removing hazardous materials from
a site to an EPA-approved hazardous waste facility for treatment, containment, or destruction;
containing the  waste safely on-site; destroying or treating the waste on-site; and identifying and
removing the source of ground-water contamination  and halting further migration of contaminants. See
cleanup and CERCLA.

REVETMENT - A retaining wall.
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                                                                                 Appendix B
REYNOLDS NUMBER - A number for porous media based on the Darcy velocity and the average
particle diameter. For most subsurface flow systems, the Reynolds number is < 1, well below the
range of turbulent flow.

RISK ASSESSMENT - (i) The qualitative and quantitative evaluation performed in an effort to define
the risk posed to human health and/or the environment by the presence or potential presence and/or
use of specific pollutants, (ii) In the RCRA process, risk assessment is an effort to characterize the
potential health risks posed by a hazardous waste site subject to RECRA requirements.

ROOT QUANTITY CLASSES - A description of roots according to the numbers of each size of root
per unit area.

ROOT SIZES - A description of roots according to their sizes, <1 mm in diameter to >5 mm in
diameter.

ROOT ZONE  - The part of the  soil occupied by roots, or subject to such occupation under normal
conditions.

ROOTS - Usually the underground parts of seed plant bodies that function as organs of absorption,
aeration, and  food storage  or as a means of anchorage and support, and differ from stems, especially
in lacking nodes, buds, and leaves.

ROTIFERS - Any of a class Rotifera of the phylum Aschelminthes. Minute, usually microscopic, but
many-celled aquatic and wet soil invertebrate animals having the anterior end modified into a retractile
disk bearing circles of strong cilia that often give the appearance of rapidly revolving wheels. See soil
microbiota.

RUBBISH - Solid waste, excluding food waste  and ashes, from  homes, institutions, and workplaces.

RUNOFF - That portion of meteoric precipitation that flows over the ground surface and enters
drainage channels, streams, and rivers. It can carry pollutants from the air or land into the receiving
waters.

RUNON - Any water, leachate,  or  liquid which flows from offsite to onsite.

SALINE SOIL - A nonsodic soil containing sufficient soluble salts to adversely affect the growth of
most crop plants. Compare with sodic soil.

SALTS - Ionic compounds composed of the cations of bases and the anions of acids. The salts
formed in reactions are soluble in  water and remain in solution as dissociated  ions, e.g., table salt,
sodium chloride.
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                                                                              Appendix B
SALT-AFFECTED SOIL - Soil that has been adversely modified for the growth of most crop plants by
the presence of soluble salts, exchangeable sodium, or both.

SALT TOLERANCE - The ability of plants to resist the adverse, nonspecific effects of excessive salts
in the rooting medium (saturated zone).

SAMPLE - See sample, Superfund and soil sample.

SAMPLE CONTROL, Superfund - Records that include sample identification tags, sample traffic
reports, chain-of-custody,  receipt-for sample forms, Field Investigation Team (FIT)  receipts, field
notebooks, airbills or bills  of lading, dioxin analysis forms (as applicable), and photographic logs, See
US EPA, 1987, A Compendium of Superfund Field Operations Methods, EPA/540/P-87/001, for further
details.

SAMPLE, HIGH CONCENTRATION, Superfund - At least one contaminant is present at a level
>15%. Samples from drums and tanks are assumed to be high concentration unless information
indicates otherwise.

SAMPLE, LOW CONCENTRATION, Superfund - The contaminant of highest concentration is present
at  < 10 ppm. Examples include background environmental samples.

SAMPLE MATRIX, Superfund - Media from which the sample is collected (e.g., soil, ground water,
and surface water).

SAMPLE, MEDIUM CONCENTRATION, Superfund - The contaminant of highest concentration is
present at a level >10 ppm and less than 15% (150,000 ppm). Examples include  material onsite that
is obviously weathered.

SAMPLE SPLITS, Superfund - An aliquot of the original sample or a sample similar in all
characteristics, and shared with an owner, operator, government agency or other designated body.

SAMPLE, Superfund - Physical evidence collected for environmental measuring and monitoring.
Evidence includes remote sensing and photographs. Also see soil sample.

SAMPLES, HAZARDOUS WASTE, RCRA - Samples defined in 40 CFR 261.3 as samples of soil,
waste, water or air collected for the sole purpose of testing to determine its characteristics or
composition in accordance with the specified regulation and designated as hazardous.

SAMPLING ACTIVITIES, Superfund - The selection, procurement, transport, relaying of sampling
information, shipping information, problems encountered during sampling, and any changes from the
originally scheduled sampling program, analysis and results of sampling. See US EPA, 1987, A
Compendium of Superfund Field Operations Methods, EPA/540/P-87/001, for additional details and
sequence of the routine sampling process.
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                                                                                 Appendix B
SAMPLING PLAN, Superfund - A program of action that is developed prior to field activities and that
describes the methods and procedures for obtaining representative portions of the environment being
investigated.

SAMPLING PROCESS, ROUTINE, Superfund - See sampling activities, Superfund.

SAND - (i) A soil particle between 0.05 and 2.0 mm in diameter, (ii) Any one of five soil separates,
namely: very coarse sand, coarse sand, medium sand, fine sand,  and very fine sand, (iii) A soil
textural class. See soil separates and soil texture.

SANDSTONE - See granular rock structure.

SANITARY LANDFILL - A site where solid waste is deposited on or within a land surface, and
subsequently compacted and covered with soil to contain or restrict movement of deposited materials.

SAPRIC SOIL MATERIALS - One of three kinds of basic organic soil material. These are the most
highly decomposed (rotten) of the organic materials. They normally have the smallest amount of plant
fiber, the highest bulk density,  and the lowest water content on a dry-weight basis at saturation. They
are commonly very dark gray to black. They are relatively stable, i.e., they change very little  physically
and chemically with time in comparison to the others. Also, see fibric and hemic soil materials.

SARA - Superfund Amendment and Reauthorization Act of 1986.  A 5-year extension and expansion of
CERCLA.  See Superfund.

SATURATE - (i) To fill all the pores (voids) between soil particles with a liquid, (ii) To form the most
concentrated solution possible under a given set of physical conditions in the presence of an excess
of the solute, (iii) To fill to capacity,  as the adsorption complex with a cation species; e.g., H+-
saturated, etc.

SATURATED SOIL - A soil with the pore spaces  (voids) completely filled with water.

SATURATED SOLUTION - A solution in which the concentration of dissolved solute is equal to that
which would be in equilibrium with undissolved solute under the given conditions (temperature  and
pressure).

SATURATED ZONE - A subsurface zone or layer in which water fills the interstices (pores) and is
under greater than atmospheric pressure.

SATURATED ZONE THICKNESS - The width of the zone in which the pores (voids) in the rock or soil
are filled with water at pressure greater than atmospheric. The water table is the top of the saturated
zone in an unconfined aquifer.  Also see unsaturated zone thickness.
Guide to Site and Soil Description             B-53

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                                                                                Appendix B
SATURATION EXTRACT - A soil sample brought to saturation point by the addition of water and
stirring. The saturation extract is used to determine the soluble salts and exchangeable sodium
content of the soil. See soil saturation point.

SECONDARY MINERAL - A mineral produced in an enclosing rock after the rock was formed through
weathering or metamorphic activity, usually at the expense of a primary material in existence earlier.

SECONDARY SOIL PARTICLES - See  aggregate, structure grades.

SEDIMENTS - Soil, sand  and minerals washed from land into water, usually after  rain. They pile up in
reservoirs, rivers, and harbors, destroying fish-nesting areas and holes of water animals and clouding
the water so that needed sunlight might not reach aquatic plants. Careless farming, mining, and
building activities will expose sediment  materials, allowing them to be washed off the land after
rainfalls.

SEEPAGE - The loss of water from a channel or water course by percolation of the water through the
natural channel bed or the material used to form the channel. May also be observed in an  excavated
soil.

SEMICONDUCTING ELEMENTS  - Metalloids. Elements  intermediate in properties between metals
and nonmetals. These elements resemble metals in appearance (grey, metallic luster), but  are more
like nonmetals in their chemical behavior. They conduct  electric current, but much less effectively than
metals. Semiconducting elements generally form covalent compounds. These seven elements are
boron, silicon, germanium, arsenic, antimony, selenium and tellurium. Their halides, like those of
nonmetals are volatile and covalent. The oxides  are acidic, except for two, As4O6 and Sb4O6, which are
amphoteric.

SEMIVOLATILE COMPOUNDS, Superfund - Carbon-containing chemical compounds that at a
relatively low temperature fluctuate between a vapor state and a liquid compound, e.g., nail polish
remover. See semivolatile organics.

SEMIVOLATILE ORGANICS - (i) Those organic  compounds having vapor pressures between 10~1  and
10~7 mmHg. (ii) Those organic compounds amenable to  extraction with an organic solvent.  See CLP
(and also refer to its Statement of Work) and semivolatile compounds.

SEPTIC TANK - An underground storage tank for wastes from homes not having sewer line to a
treatment plant. The waste goes directly from the home  to the tank, where the organic waste is
decomposed by bacteria and the sludge settles to the bottom. The effluent flows  out of the tank into
the ground through drains; the sludge  is pumped out periodically.

SERPENTINE - A  mineral or rock of a hydrous magnesium silicate, Mg3Si07 • 2H2O, usually having a
dull green color and oftentimes a mottled appearance.
Guide to Site and Soil Description             B-54

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                                                                                  Appendix B
SESQUIOXIDES - A general term for oxides and hydroxides of iron and aluminum.

SETTLING POND - A natural or artificial pond for recovering the solids from an effluent. See pond,
hazardous waste surface impoundment.

SEWAGE - The waste and wastewater produced by residential and commercial establishments and
discharged into sewers.

SILICA - Silicon dioxide occurring in crystalline, amorphous, and impure forms (as in quartz, opal, and
sand respectively).

SILICA-ALUMINA RATIO  - The molecules of silicon dioxide (SiO^ per molecule of aluminum oxide
(AI2O3) in clay minerals or in soil.

SILICA-SESQUIOXIDE RATIO - The molecules of silicon dioxide (SiOg) per molecule of aluminum
oxide (AI2O3) plus ferric oxide (Fe2O3) in clay minerals or in soils.

SILICATE CLAY - See the three main groups of silicate clays: kaolinite,  montmorillonite, and hydrous
mica.

SILT - One of the textured classes of soil particles; A soil separate consisting of particles between
0.05 and 0.002 mm in equivalent diameter. See soil separates and soil texture.

SITE - (i) In ecology, an area described or defined by its biotic, climatic, and soil conditions as related
to its capacity to produce vegetation, (ii) An area sufficiently uniform in biotic, climatic, and soil
conditions to produce a particular climax vegetation.

SITE CHARACTERIZATION - For a  RCRA Part B Permit Application for land treatment facilities
landfills, or surface impoundment, information is required on baseline environment, climatology,
hydrogeology, and a ground water monitoring plan.

SITE EVALUATION - An evaluation of the site for specific purposes, e.g., in conformance with DQOA,
CERCLA or RCRA requirements. May include residual hazardous constituents, contaminant media and
route characteristics, decomposition and immobilization processes affecting migration, plant and/or
animal toxification, certain aspects to elucidate site modification or management to improve protection
of human health, etc.

SITE INSPECTION - The collection of information from a Superfund site to determine the extent and
severity of hazards posed by the site. It follows and is more extensive than a preliminary assessment.
The purpose is to obtain information necessary to score the site, using the Hazard Ranking System,
and to determine if the site presents an immediate threat that requires prompt removal action.
Guide to Site and Soil Description              B-55

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                                                                                  Appendix B
SITE LOCATION - The position of the site, and including the potential migration of contaminants
through the soil to ground water, or in runoff off-site.

SITE MANAGER (SM), Superfund - The individual responsible for the successful completion of a work
assignment within budget and schedule. The person is also referred to as the Site  Project Manager or
the Project Manager and is typically a contractor's employee, but may be an employee of EPA, state
agency, or Potentially Responsible Party (PRP).

SITE SURVEY AND RECONNAISSANCE, PRELIMINARY, Superfund - The gathering of as much
information as possible concerning the hazard, degree of hazards, and risks that may exist, including
off-site studies so that the Field Investigation Team (FIT) will assess the hazards and identify the initial
safety hazards. See US EPA, 1987, A Compendium of Superfund Field Operations  Methods,
EPA/540/P-87/001, for additional details.

SLAKING - In geology, (i) crumbling and disintegration of earth materials when exposed to air or
moisture, or (ii) breaking  up of dried clay when saturated with water. See hardpan.

SLICKENSIDES - Polished and grooved surfaces produced by one mass sliding past another.
Slickensides are common in vertisols (soils with 30% or more clay).

SLOPE - The surface properties of the soil in terms of gradient, complexity, configuration, length, and
aspect; a property of the soil, not a landform.

SLOPE GRADIENT - The inclination of the soil surface from the horizontal. The difference in elevation
between two points is expressed as a percentage of the distance between those points.

SLUDGE - Any solid, semisolid, or liquid waste generated from a municipal, commercial, or industrial
waste water treatment plant, water supply treatment plant,  or air pollution control facility exclusive of
the treated effluent  from the waste water treatment plant.

SMALL ANIMALS - These include  both birds and animals that typically weigh less  than 16.3 kg (30
pounds) when mature.

SODIC SOIL - A nonsaline soil containing sufficient exchangeable sodium to  adversely affect crop
production (and other vegetation) and soil structure under most conditions of soil and plant type.
Compare with saline soil.

SOIL - (i) The unconsolidated mineral material on the immediate surface of the earth that serves as
natural medium for the growth of land plants,  (ii) The unconsolidated mineral matter on the surface of
the earth that has been subjected to and influenced by genetic and environmental  factors of parent
material, climate (including moisture and temperature effects), macro-, meso-, and micro-organisms,
and topography, all acting over time and producing a product, soil, that differs from the material from
which it is derived in many physical, chemical, biological, and morphological properties and
Guide to Site and Soil Description              B-56

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                                                                                 Appendix B
characteristics,  (iii) A dynamic natural body on the surface of the earth in which plants grow;
composed of mineral and organic materials and living forms. See also fertile soil, organic soil,  organic
soil materials, overburden, parent material, productive soil, subsoil, surface soil.

SOIL ADMIXTURE - A material added to soil, such as organic matter or limestone, to produce the
desired effect. May also include addition of certain wastes.

SOIL ADSORPTION FIELD - A sub-surface area containing a trench or bed with clean stones and a
system of distribution piping through which treated sewage may seep into the surrounding soil for
further treatment and disposal.

SOIL AGGREGATE - See aggregate.

SOIL AIR - The gaseous phase found within the soil, occupying the soil pores (voids) not filled with
water.

SOIL ANALYSIS - Analytical procedures to determine the properties of a soil; physical, chemical,
biological,  and mineralogical.

SOIL ASSOCIATION - A kind of map unit used in soil surveys comprised of delineations, each of
which shows the size, shape, and location of a landscape unit composed of two or more kinds of
component soils or component soils and miscellaneous areas, plus allowable inclusions in either case.

SOIL BIOLOGY - See soil microbiology.

SOIL BIOSEQUENCE - Related soils that differ from each other primarily in numbers and kinds of soil
microorganisms.

SOIL BUFFER COMPOUNDS - The solid and solution phase components of soils that resist
appreciable pH  change in the soil solution, i.e., carbonates,  phosphates, oxides, phyllosilicates, and
some organic materials.

SOIL BUFFER POWER - The ability of ions associated with the solid phase to buffer changes in ion
concentration in the solution phase.

SOIL BUFFERING CAPACITY - The resistance exhibited by a soil (solution) to a change in its pH.
Buffering capacity  is related to cation exchange capacity (CEC); soils with high CEC  are the most
strongly buffered; buffering action is due mainly to clay and very fine organic matter.

SOIL CHARACTERISTICS - Soil features or parameters which can be described or measured by field
or laboratory observations, e.g., color, temperature, water content, structure, pH, and exchangeable
cations. Often used interchangeably with soil properties.
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                                                                                 Appendix B
SOIL CHEMICAL PROPERTIES - Those characteristics, processes, or reactions of a soil which are
caused by chemical means and which can be described by, or expressed in, chemical terms or
equations. Sometimes confused with, and difficult to separate from, physical properties; hence, the
terms "physical-chemical" or "physicochemical." Examples are pH, cation and anion exchange
capacity, organic matter content and characterization; elemental analysis, etc. See soil physical
properties.

SOIL CHEMISTRY - The branch of soil science that deals with the chemical constitution, chemical
properties, and chemical reaction of soils.

SOIL CLASS - A group of soils having a definite  range  in a particular property such as acidity, degree
of slope, texture, structure, land-use capability, degree of erosion, or drainage. See soil texture and
soil structure.

SOIL CLASSIFICATION -  The systematic arrangement  of soils into groups or categories on the basis
of their characteristics. Broad groupings are made on the basis of general characteristics, and
subdivisions on  the basis of more detailed differences in specific properties.  See soil survey.

SOIL COMPLEX - (i) A kind of map unit used in soil surveys comprised of delineations, each of which
shows the size,  shape and location of a landscape unit composed of two or more kinds of component
soils, or component soils and a miscellaneous area, plus allowable inclusions in either case. The
bodies of component soils and the  miscellaneous area  are too small to be individually delineated at
the scale of 1:24,000. Several to numerous bodies of each kind of component soil or the
miscellaneous area are apt to occur in each delineation. The proportions of the components may vary
appreciably from one delineation to another and  all of the components need  not occur in every
delineation though they will be present in most delineations, (ii) Formerly defined as in(i) but the scale
of mapping was not specified.

SOIL CONDITIONER - An organic  material like humus or compost that helps soil absorb water, build
a bacterial community, and distribute nutrients and minerals.

SOIL CONTAMINANT MIGRATION - See contaminant  migration.

SOIL CONTAMINATION - See soil  pollution.

SOIL CREEP - Slow mass movement of soil and soil material down  relatively steep slopes, primarily
under the influence of gravity but facilitated by saturation with water and by alternate freezing and
thawing. Also see  solifluction.

SOIL CRUMBS  - See aggregate.

SOIL CRUST - A soil-surface layer, ranging in thickness from a few  millimeters to a few tens of
millimeters, that is much more compact, hard, and brittle, when dry, than the material immediately
Guide to Site and Soil Description              B-58

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                                                                                  Appendix B
beneath it. Crust formation may be exacerbated or disrupted by application of chemicals to the soil
surface. Also see desert crust.

SOIL DEGRADATION - The process of changing a soil from one "type" to a more highly leached one.

SOIL DEPTH - Soils may be classed as micro, shallow, or deep in depth. Micro is <  18 cm through
diagnostic horizons; two depths are shallow, based upon horizons, great soil groups and subsoil
groups; < 50 cm and < 100 cm. Refer to USDA Soil Survey Staff, 1990, Key to Soil Taxonomy, SMSS
Tech. Monogr. No. 19, for additional details.

SOIL DESCRIPTION - Any data, quality, characteristic, property, or parameter used to define the
nature and extent of a soil by any of its common attributes. Attributes are usually obtained by
sampling and analysis or in situ measurements and observations.

SOIL DISCONTINUITY - A significant change in particle-size distribution or mineralogy that indicates a
difference in the  material from which the horizon is formed and/or a significant difference in age.

SOIL ECOLOGY - A broad concept of soil and its behavior in the total environment to include both
living and nonliving factors and their interactions with soil.

SOIL EROSION  - See erosion and erosion classes.

SOIL EXTRACT - The solution separated from a soil suspension or from a soil by filtration,
centrifugation, suction, or pressure. (May or may not be heated prior to separation.)

SOIL FAMILY - In soil classification one of the categories intermediate between the great soil group
and the soil series. Families provide groupings of soils with ranges in texture, mineralogy, temperature,
and thickness. See soil classification.

SOIL FLOW - See solifluction.

SOIL FORMING  FACTORS - Basically, the development of soil within a landscape in steps and
stages as affected by time, topography, climate, minerals, organisms and other related factors.

SOIL GEOMETRY - See pore geometry.

SOIL HORIZON  - A layer of soil or soil  material approximately parallel to the land surface and differing
from adjacent genetically related layers in physical, chemical and biological properties or
characteristics such as color, structure, texture, consistency, kinds and number of organisms present,
degree of acidity or alkalinity, etc. See soil master horizons and layers, genetic soil horizon.
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                                                                                  Appendix B
SOIL HORIZON SYMBOLS - In soil survey, an indication of the direction of presumed pedogenesis
(formation of soil structure), while diagnostic horizons indicate the magnitude of that expression. See
diagnostic soil horizons.

SOIL HYDROLOGY - The science dealing with the distribution and movement of the soil solution in
the soil profile.

SOIL INFILTRATION - The penetration of water or other liquids through the surface of the soil
(ground)  into the sub-surface soil. See soil water infiltration.

SOIL INHIBITOR - Any agent that interferes with soil processes, e.g., addition of toxic wastes to
interfere with soil microbial metabolism.

SOIL INTERGRADE - A soil that possess moderately well-developed distinguishing characteristics of
two or more genetically-related classification units. Also see transitional soil.
          /
SOIL INTERPRETATIONS - Predictions of soil behavior in response to specific uses or management.
These are based on inferences from soil characteristics and qualities (e.g., trafficability, credibility,
productivity, etc.). They are either qualitative or quantitative estimates or ratings of soil productivities,
potentials, or limitations.

SOIL INTRINSIC PERMEABILITY - The permeability of a soil or other  porous medium as a property of
the medium only, independent of the density and viscosity  of the fluid. Hydraulic conductivity K is
inversely  proportional to the viscosity JL/ of the water. The constancy of the product Ky is the basis for
intrinsic permeability.

SOIL KIND - A soil with distinguishing characteristics. See soil type and soil map unit.

SOIL LICHENS - An association (symbiosis) of an algae and a fungus to form crustose, foliose, or
fruticose  bodies on the soil surface.

SOIL LIQUID PHASE - All the liquids and/or chemicals in the soil system. See soil water.

SOIL MACROFAUNA (MACROBIOTA) - Soil-inhabiting biota that generally include the larger insects,
earthworms (Lumbricidae) and other organisms which  can  be easily sorted by hand; and commonly
including burrowing vertebrates,  such as  moles, ground squirrels, pocket gophers, and reptiles such
as tortoises and snakes, which affect soil structure.

SOIL MAP - A map showing the distribution of soil "types" or other soil mapping units in relation to the
prominent physical and cultural features of the earth's  surface. See American Society of Agronomy,
1987 Glossary of Soil Science Terms, for  details on kinds of soil maps.
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                                                                                  Appendix B
SOIL MAP UNIT - (i) A conceptual group of one to many delineations identified by the same name in
a soil survey that represent similar landscape areas; (ii) A loose synonym for a delineation of soils.
Also see soil "type,"  and soil series.

SOIL MASTER HORIZONS AND LAYERS -
       O horizons  - Layers dominated by organic material, except limnic layers that are organic.
       A horizons - Mineral horizons that formed at the surface or below an O horizon and (i) are
       characterized by an accumulation of humified organic matter intimately mixed with the mineral
       fraction and not dominated by properties characteristic of E  or B horizons; (ii) have properties
       resulting from cultivation, pasturing or similar kinds  of disturbances.
       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 (i)
       carbonates,  gypsum, or silica, alone or in combination; (ii) evidence of removal of carbonates;
       (iii) concentrations of sesquioxides; (iv) alterations that form silicate clay; (v) formation of
       granular, blocky, or prismatic structure; or (vi) 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.
See USDA Soil Survey Staff, 1990, Keys to Soil Taxonomy, SMSS Tech. Monogr. No. 19, and other soil
taxonomy references for details.

SOIL MECHANICAL ANALYSIS - The separation of a soil into its content of clay, silt, and sand
fractions  (e.g., soil separates) by mechanical means, and the determination of the percentage of each
group in  a given sample,  i.e., particle size analysis. See soil separates and particle size distribution.

SOIL MESOFAUNA (MESOBIOTA) - Soil-inhabiting animals smaller  than soil macrobiota and larger
than soil  microbiota  (microorganisms), including nematodes, small oligochaete worms (Enchythaeids),
smaller insect larvae, and the microarthropods; of the latter, the soil  mites (Acarina), and springtails
(Collembola) are often the most abundant permanent soil inhabitants.

SOIL METAL PERSISTENCE - The length of time a metal species or compound will stay in a given
soil matrix following the introduction of the metal into or onto the soil.  Persistence can range from less
than a second to indefinitely.

SOIL MICROBIAL POPULATION - The total number of living microorganisms in  a given volume or
mass of soil.

SOIL MICROBIOLOGICAL PROPERTIES - Those properties of the soil relating to soil-inhabitating
microorganisms, their functions and activities, e.g., kinds and numbers of soil microflora  and
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                                                                                 Appendix B
microfauna, organic matter decomposition, transformation of hydrocarbons and various elements,
biogeochemical cycles, etc.

SOIL MICROBIOLOGY - The branch of soil science concerned with soil-inhabiting microorganisms
and their functions and activities.

SOIL MICROBIOTA - Generally, microscopic forms, such as soil algae, especially green and blue-
green types and diatoms, autotrophic and heterotrophic, symbiotic and nonsymbiotic bacteria, fungi,
actinomycetes, streptomycetes, protozoa, and myxomycetes. Viruses may be included, although they
are submicroscopic in size. See microflora, microfauna, and mycorrhiza.

SOIL MICROFAUNA - See microfauna.

SOIL MICROFLORA - See microflora.

SOIL MICROHABITAT - The pores (voids) of various kinds within a soil in which bacteria, fungi and
other microorganisms live. Also see microsite.

SOIL MINERAL - (i) Any  mineral that occurs as a part of or in the soil, (ii) A natural inorganic
compound with definite physical, chemical, and crystalline properties (within the limits of isomorphism)
that occurs in the soil. See clay mineral.

SOIL MINERAL FRACTION - In general, the content of gravel, sand, silt, and clay.

SOIL MINERALOGICAL PROPERTIES - Characteristics, processes and reactions of a soil associated
with soil minerals, and which can be described by,  or expressed in, chemical and physical terms and
equations. Included separately, or as chemical and physical properties of a soil. See soil chemical
properties, soil physical properties, soil mineral, clay mineral, and phyllosilicate mineral.

SOIL MOISTURE CONTENT - See soil water (moisture) content.

SOIL MOISTURE (WATER) POTENTIAL - A measure of the difference in the free energy state of soil
water and that of pure water. Technically defined as that amount of work that must be done per unit
quantity of pure water in order to transport reversibly and isothermically an infinitesimal quantity of
water from a pool of pure water, at a specified elevation and at atmospheric pressure, to the soil water
(at the point under consideration). See soil water. Also see Soil Science Society of America, 1987,
Glossary of Soil Science Terms, for additional details.

SOIL MOISTURE (WATER) REGIMES - The presence or absence either of ground water or water
held  at a tension less than 1500 kPa (<15 bar moisture or water tension, near permanent wilting
point) in the soil or in specific horizons by periods of the year.  Water held at a tension of 1500 kPa or
more is not available to keep most mesophytic plants alive. The availability of water also is affected by
Guide to Site and Soil Description              g-62

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                                                                                   Appendix B
dissolved salts. Soil moisture status over a period of time can be relegated to soil temperature
regimes in particular climatic zones, e.g., an aridic and torric (hot and dry) soil moisture regime.

SOIL MORPHOLOGY - (i) The physical constitution, particularly, the structural properties, of a soil
profile as exhibited by the kinds, thickness, and arrangement of the horizons in the profile, and by the
texture, structure, consistency, and porosity of each horizon, (ii) The structural characteristics of the
soil or any of its parts. See soil structure.

SOIL NAME - The basic name of the predominant constituent and a single-word modifier indicating
the major subordinate constituent.

SOIL NUTRIENT DIFFUSION - The movement of nutrients in soil or pedon as a result of a
concentration gradient.

SOIL NUTRIENT - See macronutrients and micronutrients.

SOIL ORDER - A category within the schema of soil classification based upon soil-forming processes
as indicated by the presence or absence of major diagnostic horizons. See soil diagnostic horizons.

SOIL ORGANIC RESIDUE - Animal and vegetative materials added to the soil and which are
recognizable as to their origin.

SOIL PARAMETER - A specific soil measurement or property, especially one  that can be quantified.
See soil properties.

SOIL PERMEABILITY - (i) The rate at which water or other liquids pass through soil in a specified
direction, usually by gravitational flow; (ii) The ease with which gases,  liquids,  or plant roots penetrate
or pass through a bulk mass of soil or a layer of soil. Since different soil horizons vary in permeability,
the particular horizon under question should be designated, (iii) The property  of a porous medium
itself that expresses the ease with which gases, liquids, or other substances can flow through it, and  is
the same as intrinsic permeability k. See Darcy's law and soil water.

SOIL pH - See soil reaction.

SOIL PHYSICAL PROPERTIES - Those characteristics, processes, or reactions of a soil which are
caused by physical forces and which can be described by, or expressed in, physical terms or
equations. Sometimes confused with and difficult to separate from chemical properties; hence, the
terms physical-chemical or physicochemical. Examples of physical  properties  are bulk density, water-
holding capacity, hydraulic conductivity, porosity, pore-size distribution, etc.

SOIL PHYSICS - The branch of soil science that deals with the physical properties of the soil, with
emphasis on the state and transport of matter (especially water) and energy in the soil.
Guide to Site and Soil Description             B-63

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                                                                                   Appendix B
SOIL PLASMA - That part of the soil material that is capable of being or has been moved,
reorganized, and/or concentrated by the processes of soil formation. It includes all the material,
mineral or organic, of colloidal size and  relatively soluble material that is not contained in the skeleton
grains. See soil forming factors, minerals, organic matter, colloids.

SOIL POISE - See poised soil system.

SOIL POLLUTANT IMMOBILIZATION -  In a contaminated soil environment, the irreversible sorption of
pollutants, thus preventing leaching.  Compare with immobilization.

SOIL POLLUTION - Deterioration of the quality of the soil as determined by various soil characteristics
that are affected by the addition of impurities, e.g., waste substances and materials.

SOIL POPULATION - (i) All the organisms living in the soil, including plants and animals,  (ii)  Members
of the same taxa.  (iii) Delineations of the same map unit - a grouping of like things in a statistical
sense. See soil map unit.

SOIL PORE GEOMETRY - See pore geometry.

SOIL PORES - That part of the bulk volume of soil not occupied by soil particles. Soil  pores  have also
been referred to as interstices or voids.

SOIL PROFILE - A vertical section of the soil through all its horizons and extending into the parent
material. An excavated soil exposes the  soil  profile.

SOIL PROPERTIES - See soil characteristics. (Sometimes considered to be more definitive and
quantitative than general soil characteristics.)

SOIL QUALITIES - Inherent attributes of soils which are inferred from soil characteristics or indirect
observations, e.g., compactibility, erodibility or fertility.  See soil characteristics.

SOIL QUALITY - The characteristics  or properties identified for a soil, depending upon its intended
use or purpose, and an  assessment  of the soil for that particular use or purpose, e.g., a soil  having
unfavorable characteristics for plant growth is a soil of poor quality.

SOIL REACTION  (pH) - The degree  of acidity or alkalinity of a soil,  usually expressed  as a pH value,
and ranging from  extremely acid, pH <  4.5,  through very strongly alkaline, pH  > 9.1.   Soil pH is the
negative logarithm of the hydrogen ion activity, usually of a soil solution or paste.

SOIL REDOX POTENTIAL (Eh) - The ratio of reduced to oxidized substances  in a soil. A
measurement of redox potential  can  give a reliable measurement of soil aeration. See  redox  potential
and aerated soil.
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                                                                                   Appendix B
SOIL SAMPLE - A portion of the soil mass taken for the purpose of estimating certain soil
characteristics or parameters, either for field or laboratory analysis.  See sample, Superfund.

SOIL SATURATION POINT - That point at which water or chemicals completely saturate the soil and
fill the pores. See saturated soil, saturation extract.

SOIL SCIENCE - That science dealing with soils as a natural resource on the surface of the earth
including soil formation, classification and mapping, and physical, chemical, biological, and fertility
properties of soils per se; and these properties in relation to their use and management. Edaphology
deals with the influence of the soils on living things. Pedology mainly considers soil as a biochemical
product of nature.

SOIL SEPARATES - Mineral particles, <  2.0 mm in equivalent diameter, ranging between specified
size limits. The names and size limits of separates recognized in the United States are: very coarse
sand, 2.0 to 1.0 mm; coarse sand, 1.0 to  0.5 mm; medium sand, 0.5 to 0.25 mm; fine sand, 0.25 to
0.10 mm;  very fine sand,  0.10 to 0.05 mm; s/7f, 0.05 to 0.002 mm; and clay, < 0.002 mm. The
separates recognized by the International Society of Soil Science are: I) coarse sand, 2.0 to 0.2 mm;
II) fine sand, 0.2 to 0.02 mm; III) silt, 0.02 to 0.002 mm; and IV) clay, < 0.002 mm.

SOIL SERIES - The lowest category of U.S. system of soil taxonomy; a conceptualized class of soil
bodies (polypedons) that  have limits and ranges more restrictive than all higher taxa. Soil series are
commonly used to name dominant or codominant polypedons represented on  detailed soil maps. The
soil series serve as a major vehicle to transfer soil information and research knowledge from one soil
area to another. See polypedon and soil  map.

SOIL SOLID PHASE - All  of the soil solid particles in the soil system. See soil separates.

SOIL SOLIDS - See soil solid phase, soil separates, void ratio.

SOIL SOLUTES - The chemical substances, micronutrients, macronutrients, or contaminants dissolved
in the soil solution or liquid phase. See soil solution.

SOIL SOLUTION - The liquid phase of a  soil, i.e., that part of the soil system not occupied by  mineral
particles or soil air. It usually consists of water, soluble salts, and other materials, e.g., humus
particles, suspended in it.

SOIL SPATIAL VARIABILITY - The variation  in soil properties (1) laterally across the landscape, at a
given depth, or with a given horizon, or (2) vertically downward through the soil.

SOIL STRATA - Soil arranged in or composed of strata or layers. Soil layers may be applied to cover
reclamation sites, waste sites and materials.
Guide to Site and Soil Description              B-65

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                                                                                  Appendix B
SOIL STRUCTURE - The combination or arrangement of primary soil particles into secondary
particles, units, or peds. See structure classes, grades, and types.

SOIL SUBORDINATE DISTINCTIONS - In soil survey, 22 subordinate distinctions and characteristics
are recognized within master horizons and layers and are used to further characterize master horizons
and layers. See soil master horizons and layers.

SOIL SURFACE - See surface soil.

SOIL SURFACE SEAL - The presence of a compacted or hydrophobic layer on the surface of the soil
that reduces water (or other liquid) infiltration.

SOIL SURVEY - The systematic examination, description, classification, and mapping of soils in an
area.  Soil surveys are classified according to the kind and intensity of field examinations and certain
soil analyses.

SOIL TAXONOMIC CLASSES - In the context of soil survey, a class used in the system of soil
classification or taxonomy. Diagnostic  horizons and properties  are used to identify the eleven classes
(orders) of a soil. For details, see  US EPA, 1990, Keys to Soil Taxonomy, SMSS Tech. Monogr. No. 19,
and other soil taxonomy references.

SOIL TAXONOMY - The science of classifying soils. See soil survey.

SOIL TEMPERATURE - See temperature (soil).

SOIL TEST - A  chemical, physical or biological procedure which estimates a property of the soil
pertinent in the  agricultural sense usually to the suitability of the soil to support plant growth.

SOIL TEXTURE -  Relative proportions of the various sizes of mineral particles  (gravel, sand,  silt, clay)
in a soil.

SOIL TEXTURE BY "FEEL" - See  sticky point.

SOIL TEXTURE CLASSES - The  relative proportions of the various soil separates (mineral particles of
sand, silt, and clay < 2.0 mm in diameter), and described into textural classes on the basis of the
proportions of the various separates present. See soil separates.

SOIL "TYPE"  - (Note: obsolete) Formerly in the U.S. soil classification systems prior to publication
USDA So/7 Taxonomy (1975). (i) The lowest unit in the natural system of soil classification; a
subdivision of a soil series and consisting of or describing soils that are alike in all characteristics
including the texture of the A horizon or plow layer, (ii) In Europe, roughly equivalent to a great soil
group, (iii) A kind  of soil, as used  popularly in nonsoil literature and technical documents. See soil
series and soil map unit.
Guide to Site and Soil Description             B-66

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                                                                                 Appendix B
SOIL VOIDS - See soil pores.

SOIL WASHING OR FLUSHING - For RCRA corrective action, excavated soil is flushed with water or
other solvents to leach out contaminants; used for organic wastes and certain soluble inorganic
wastes.

SOIL WASTE MANAGEMENT UNIT - Any unit in which wastes have been placed at any time,
regardless of whether the unit was designed to accept solid or hazardous waste. Units include areas
from which solid wastes have been routinely released.

SOIL WATER BUDGET - The amount of measurable water in the soil system or profile over a
specified period of time.

SOIL WATER (MOISTURE) - Water in soil is subject to several force fields originating from the
presence of the soil solid phase; the dissolved salts; the action of external gas  pressure; and the
gravitational field. These effects may be quantitatively expressed by assigning an individual
component potential to each. The sum of these potentials is designated the total potential of soil
water. See soil water total potential, and soil moisture (water) content. Also see Soil Science Society of
America, 1987, Glossary of Soil Science Terms, for additional details.

SOIL WATER (MOISTURE) CONTENT - The water lost from the soil upon drying to constant mass at
105 °C; and  expressed either as the mass of water per unit mass of dry soil or as the volume of water
per unit bulk volume of soil.  (Constant weight is usually obtained after 24 hrs.)

SOIL WATER DIFFUSIVITY - The hydraulic conductivity divided by the differential water capacity (care
being taken to  be  consistent with units), or the flux of water per unit gradient of moisture content in
the absence of other force fields.

SOIL WATER INFILTRATION - The downward entry (penetration) of water into the soil through the
soil surface. See infiltration.

SOIL WATER MATRIC POTENTIAL - The amount of work that must be done per unit quantity of pure
water in order to transport reversibly and isothermally an infinitesimal quantity of water, identical in
composition to the soil water, from a pool at the elevation and the external gas pressure of the point
under consideration, to the soil water.

SOIL WATER PERCOLATION  - The downward movement  of water through the soil, especially in
saturated or nearly saturated soil at hydraulic gradients of the order of 1.0 or less. See hydraulic
gradient, hydraulic conductivity and Darcy's  law.

SOIL WATER PRESSURE - The pressure (positive or negative), relative to the external gas  pressure
on the  soil water, to which a solution identical in composition to the soil water must be subjected in
order to be in equilibrium through a porous permeable wall with the soil water.
Guide to Site and Soil Description              g-67

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                                                                                Appendix B
SOIL WATER SORPTIVITY - In hydraulic conductivity of unsaturated soils the cumulative infiltration, I,
into a soil column having uniform time, t; i.e., I = ST1/4. The coefficient of proportionality, S, varies with
water content and differs between soils and is termed sorptivity.

SOIL WATER TOTAL POTENTIAL - The mechanical work required to transfer unit quantity of water
from a standard reference point to a given situation in the soil. Referred to unit weight of water,  it has
the dimension of length and is known as suction head.

SOLAR RADIATION, INCOMING - Also  referred to as "insolation," the total electromagnetic radiation
emitted by the sun and falling on the earth. Data can usually be directly related to atmospheric
stability. Models to compute rates of chemical volatilization or vaporatization may use solar radiation
data quantitatively.

SOLID WASTE - A variety of discarded,  degradable, and nondegradable wastes, not generally toxic or
hazardous, resulting from industrial, municipal, agricultural, home and institutional sources, usually
deposited in open dumps or sanitary landfills. Nontoxic and nonhazardous mining wastes may  be
included.

SOLID WASTE DISPOSAL ACT (SWDA) - This Act was amended in 1986 by The Resource
Conservation and Recovery Act (RCRA). SWDA has since been amended by several public laws,
including the Used Oil Recycling Act of 1980 (UORA), the Hazardous and Solid Waste Amendments of
1984 (HSWA), and the Medical Waste Tracking Act of 1988 (MWTA). See RCRA.

SOLID WASTE DISPOSAL - The final placement of waste refuse that is not salvaged or recycled.

SOLID WASTE MANAGEMENT - Supervised handling of waste materials from  their source through
recovery processes to disposal.

SOLID WASTE, Superfund - Any solid, semisolid, liquid,  or contained gaseous material present in
wastes.

SOLID WASTE TOXICITY - An extraction procedure (EP) developed by EPA to simulate waste
leachate in sanitary landfills. The extract is analyzed for the presence- of eight specific elements  and
six specific organic  compounds (pesticides) to determine if thresholds are exceeded. The  EP extract
should not contain elements or compounds equal to or greater than designated concentrations. If any
of the limits are exceeded, the waste has the characteristic of EP toxicity and is classified as a
hazardous waste. See hazardous waste.

SOLIFLUCTION - The slow (normally 0.5 to 5.0 cm/year) viscous, downslope flow of waterlogged soil
and other saturated surficial material.

SOLUM - (plural: SOLA) The upper and  most weathered part of the soil profile; the A, E, and B
horizons. See soil master horizons and layers.
Guide to Site and Soil Description             B-68

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                                                                                Appendix B
SOLUTE - The component of a solution, e.g., soil metal, ion or organic substance, usually present in
the smaller amount.

SOLVENT - The component of a solution usually present in the larger amount.

SORPTION - (i) The action of soaking up or attracting substances; a process used in many pollution
control systems; (ii) A physical/chemical process in which the increase of solute concentration evolves
at the soil-water interface.  See adsorption and absorption.

SORPTIVITY - See soil water sorptivity.

SOURCE CONCENTRATION - The concentration of a contaminant in the soil of a site (i.e., the source
of ground water contamination).

SPECIAL WASTE - (i) Waste materials that occur in very large volumes, but with low potential hazard;
generally not amenable to management techniques developed for hazardous waste; (ii) Waste
streams that do not come under RCRA purview, but are considered hazardous. Examples of regulated
materials include  oil waste, in specific states spent lead acid batteries, and PCBs and asbestos which
are considered hazardous under the Toxic Substances Control Act (TSCA).

SPECIES - A reproductively isolated aggregate of interbreeding populations of organisms.

SPECIFIC HAZARDOUS WASTE SOURCES - Waste generated during the manufacturing processes
of certain industries;  inorganic pigments; inorganic chemicals; organic chemicals; wood preservatives;
pesticides; petroleum refining; iron, steel, and secondary lead smelting; coking; ink formulation; and
veterinary Pharmaceuticals.

SPILL - Any unplanned or accidental discharge (event), release, dumping, emitting, emptying, and
pumping of hazardous waste onto or in land (soil), air, or water, and which is denoted as hazardous.

SPILL PREVENTION CONTROL AND COUNTERMEASURES PLAN  - A  plan covering the release of
hazardous substances as defined in the Clean Water Act.

SPOIL -  Soil (dirt) or rock removed from its original location, thereby destroying the inherent nature of
the soil in the process of removal.

STAGING AREA - A section of a site with adequate control (e.g., paved and drained runon prohibited)
for the safe storage and handling of drummed waste or other hazardous  materials.

STANDARD MEDIUM - Any culture medium commonly used to grow  and enumerate microorganisms.

STICKY POINT (OF A SOIL) - The point at which a moistened sample of soil can  be worked easily
between the fingers, but has no tendency to run or flow. Soil at this moisture content is  used to help
Guide to Site and Soil Description              B-69

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                                                                                Appendix B
determine the texture by "feel" in the field rather than by mechanical analysis in the laboratory. Also
see soil mechanical analysis.

STORAGE - Temporary holding of waste pending treatment or disposal. Storage methods include
containers, tanks, waste piles, and surface impoundments.

STREPTOMYCETES - A group of microorganisms usually classified as a family, Streptomycetaceae,
within the Actinomycetes.  Microorganisms are found with vegetative mycelium found in bacillary or
coccoid forms; a member of the genus Sfreptomyces. See microfauna and actinomycetes.

STRONG GLEYED SOIL - Soils that either have iron that has been reduced and removed during soil
formation or that saturation with stagnant water has preserved  a reduced state.  Most of the affected
layers have low chroma and many are mottled. See gleyed soil, mottle and color, chroma.

STRUCTURE CLASSES - A grouping of soil structural units or peds on the basis of size.

STRUCTURE GRADES - A grouping or classification of soil structure (the combination or arrangement
of primary soil particles into secondary particles, units, or peds) on the basis of inter- and  intra-
aggregate adhesion, cohesion, or stability within the profile.

STRUCTURE TYPES - A classification of soil structure based on the shape of the aggregates or peds
and their arrangement in the profile.

SUBSIDENCE - The lowering of the natural land surface in response to natural, artificial, or induced
causes.

SUBSOIL - The soil found in nature beneath the topsoil, usually less modified by soil-forming factors
and containing less humus, soil nutrients, and microorganisms, and other distinctive soil properties.

SUBSTRATUM - Any layer lying beneath the soil solum, either conforming or unconforming.

SUCTION HEAD - See soil water matric potential.

SUPERFUND - The program operated under the legislative authority of CERCLA and SARA that funds
and carries out the EPA solid waste emergency and long-term removal remedial activities. These
activities  include establishing the National Priorities List, investigating sites for inclusion on the list,
determining their priority level on the list, and conducting and/or supervising the ultimately determined
cleanup and other remedial actions. See CERCLA and SARA.

SURFACE - The exterior or outside part of the solid or liquid Earth.

SURFACE DRAINAGE - (i) The removal of excess water from the surface of the soil, (ii) Used to refer
to surface movement of excess water.  Includes such terms as ponded, flooded, slow,  and rapid.
Guide to Site and Soil Description             B-70

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                                                                                Appendix B
SURFACE EROSION AND ERODIBILITY - Erosion:  wearing away of the soil or land surface by
running water, wind, ice, or other geological agents,  including such processes as gravitational creep.
Erodibility: the vulnerability or degree of susceptibility of soil to erosion processes.

SURFACE FEATURES - Conspicuous features on the soil surface that may be examined and
described, including not only natural features, but distinct artificial features introduced through human
activities.

SURFACE HYDROLOGY - The science dealing with the distribution and conveyance of water on the
soil surface.

SURFACE IMPOUNDMENT - A natural topographic depression, manmade excavation or diked area,
usually formed of earthen materials or lined with manmade materials, designed to contain liquids, or
wastes containing free liquids. See hazardous waste surface impoundment, pit, pond, lagoon.

SURFACE IMPOUNDMENT HAZARDS - Potential hazards from impoundments including leakage of
hazardous substances to the surrounding soil,  underlying vadose (unsaturated) zone, and  especially
to ground water; and, gaseous emissions of volatile materials.

SURFACE LAYER - See surface soil.

SURFACE POLLUTION SITUATIONS - Contamination of the soil with various harmful compounds and
materials primarily introduced by human activities, e.g., metals in waste materials.

SURFACE RUNOFF - That portion of the meteoric precipitation on an area of soil or land surface
which is discharged from the area through natural or manmade stream channels.

SURFACE SOIL - The uppermost part of the soil, considered in  agriculture as that ordinarily moved in
tillage, or its equivalent in uncultivated soils, and ranging in depth from 7-20 cm. Frequently
designated as the "surface layer," ("Ap layer," or the "Ap horizon"). Also see tillage.

SURFACE TIER - The surface tier is the upper 60 cm (24 in.) if (1) the soil material is fibric and three-
fourths or more of the fiber volume is derived from Sphagnum or mosses, or (2) the material has a
bulk density less than 0.1; otherwise, the surface tier is the top 30 cm (12 in.) exclusive of loose
surface litter or living mosses. See fibric soil material.

SURFACE WATER - All waters on the face of the Earth, including fresh and salt water, ice  and snow.
Soil water is not included.

SURFICIAL - Pertaining to, situated at, formed or occurring on a surface.

SURFICIAL CREEP - See soil creep.
Guide to Site and Soil Description              B-71

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                                                                                 Appendix B
SURFICIAL AND BEDROCK GEOLOGY - The surficial geology of a region is usually contrasted with
or studied separately from the bedrock geology. Surficial usually refers to the unconsolidated materials
(overburden) such as the glacial sediments, alluvium, or soil. Also see bedrock.

SWAMP - An area saturated with water throughout much of the year but with the surface of the soil
usually not deeply submerged. Usually characterized by tree or shrub vegetation. See marsh and
miscellaneous areas.

TAILINGS - By-products of mining and milling; residues of raw materials or waste separated during
the processing of mineral ores or crops.

TARDIGRADES - Any of a division Tardigrada of microscopic arthropods that have four pairs of legs
and usually live in water or damp moss. Also found in soil moss-lichen habitats.  See arthropod.

TAXONOMY - The systematic distinguishing, classification, and naming of type groups within a
specified subject field. See soil taxonomy and soil survey.

TEMPERATURE (SOIL) - The degree of  heat of a given body  of soil at a particular point in time and
space or during a particular period of time and a particular depth or surface  extent of soil; usually
determined in °F or °C.

TEMPERATURE GRADIENT - The rate of decrease of air, water, or soil temperature with distance,
usually in the direction it decreases most rapidly. Temperature gradients may be encountered at
waste sites depending on the nature and concentration of contaminants, the period of time of
contamination, and rate of degradation.

TEMPERATURE REGIMES OF  SOIL - The pattern of soil temperature fluctuations in a soil,
characterized by temperature distribution with respect to depth, time, and season for a given soil at a
given location. See knowledge frames  for values: perigelic, cryic, frigid-isofrigid, mesic-isomesic,
thermic-isothermic, and hyperthermic-isohyperthermic.

TENSIOMETER - A device for measuring the soil-water matric potential (or tension, or suction) of
water in soil in situ; a porous, permeable ceramic cup connected through a water-filled tube to a
manometer, vacuum gauge, pressure transducer, or other pressure measuring device.  See hydraulic
head and  piezometer.

TERRACING - Diking, built along the contour of sloping agricultural land, that holds runoff and
sediment to reduce erosion.

TEXTURE CLASSES - The relative proportions of the various soil separates (mineral particles of sand,
silt, and clay < 2.0 mm diameter) and  described into textural classes on the basis of the proportions
of the various separates present. Contrast particle-size classes.
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                                                                                 Appendix B
THERMAL POLLUTION - A change in the quality of an environment due to induced substances or
materials causing a raise in temperature.

THERMODYNAMICS - The branch of physics that seeks to derive, from a few basic postulates,
relationships between properties of matter, especially those affected by changes in temperature, and a
description of the conversion of energy from one form to another. Thermodynamics are important in
soil processes such as water potential, solute movement and exchange, etc. Also see ion activity.

THRESHOLD LIMIT VALUE - Representations of the air concentrations of chemical substances to
which it is believed that workers may be exposed daily without adverse effect.

TIGHT SOIL - A compact and relatively impervious and tenacious soil (or subsoil) which may or may
not be plastic (capable of being molded or transformed). Also see plastic soil.

TILLAGE - The mechanical manipulation of soil; in the agricultural sense, the modification of soil
conditions for successful crop production.

TILTH - The  physical condition of a soil in relation to ease of tillage (cultivating) and plant growth. See
tillage.

TOLERANCE - The capacity of an organism to live under a given set of conditions within its range of
ecological amplitude. See ecological amplitude.

TOLERANCES, pesticides - The permissible residue levels for pesticides in raw agricultural produce
and processed foods. Tolerance levels are established by EPA and enforced by FCA and USDA.

TOPOGRAPHIC MAPS - A map showing the relief of the land surface by means of contour lines.

TOPOGRAPHY - The physical features of  a surface area including relative elevations and the position
of natural and man-made features.

TOPSOIL - The surface layer of soil commonly moved during cultivation,  usually containing humus;
because of presumable fertility, it is applied to topdress landfills, waste sites, and roadbanks, etc.;
usually capable of supporting plant growth. See tillage.

TORTUOSITY - (i) The average ratio of the actual roundabout path to the apparent or straight flow
path (in a soil). See soil geometry, hydraulic  conductivity, (ii) The nonlinear nature of soil pores.

TOXICANT - A poisonous agent that kills or  injures animal or plant life.

TOXIC POLLUTANTS - Materials contaminating the environment that cause death, disease, and/or
birth defects in organisms that ingest or absorb them. The quantities and length of exposure
necessary to cause these effects can vary widely.
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                                                                                Appendix B
TOXIC SUBSTANCE - A chemical or mixture that may present an unreasonable risk of injury to health
or the environment.

TOXIC WASTE - Any waste or substance whose physiological action is harmful to human or animal
health or the environment.

TOXICITY - The degree of danger posed by a substance to animal or plant life. (May be described as
acute or chronic toxicity.)

TOXICITY CHARACTERISTIC (TC) RULE - This rule replaces the Extraction Procedure (EP) toxicity
test with the TC test to determine whether or not a waste is a characteristic waste based on toxicity.
The new TC rest requires analysis of 25 organic compounds in addition to the eight metals and six
pesticides that were subject to the EP test. See also toxicity characteristic leaching procedure.

TOXICITY CHARACTERISTIC LEACHING PROCEDURE (TCLP) - The analytical method one must
use to determine whether or not a waste is a characteristic hazardous waste based on toxicity. The
TCLP is also necessary to comply with provisions of land disposal restrictions as well. See also toxicity
characteristic  rule.

TOXICITY TEST EXTRACTION PROCEDURES - An EPA toxicity test used to define hazardous
wastes. See solid waste toxicity.

TRAFFICABILITY - The quality of the terrain or site to permit passage, as of vehicles or personnel.

TRANSITIONAL HORIZONS - Soil horizons that are transitional  or gradients between soil master
horizons and layers. There are two kinds of transitional horizons. In one, the properties of an
underlying or  overlying horizon are superimposed on properties of the other horizon throughout the
transition zone. In the other, parts that are characteristic of an overlying or underlying horizon are
enclosed by parts that are characteristic of the other horizon. Special conventions are used to
designate these kinds of horizons. Also see soil master horizons and gradients and USDA, 1990, Keys
to Soil Taxonomy,  SMSS Tech. Monogr. No. 19, or other soil taxonomy references, for details.

TRANSITIONAL SOIL - A soil that possesses properties and distinguishing characteristics of two or
more soils;  soil intergrates. Compare with transitional horizons.

TRANSPORT RATES - The rate of movement of a contaminant  in a natural transport medium such as
soil or ground water, either as solid particles or in solution, from one place to another.

TRANSPORTED SOIL - Soil materials and soil parent material moved usually by various natural
agencies, gravity, water, ice and wind.

TRANSURANIC WASTE - Waste that contains manmade elements heavier than uranium; includes
those having an atomic number greater than that of uranium, i.e., greater than 92.  Most transuranic
Guide to Site and Soil Description             B-74

-------
                                                                               Appendix B
waste results from reprocessing nuclear fuel. Disposal is similar to high-level waste because of its
long decay period.  See high-level radioactive waste.

TREATMENT, STORAGE, AND DISPOSAL (TSD) FACILITY - The site where a hazardous substance
is treated, stored, or disposed. TSD facilities are regulated by EPA and states under RCRA.

TRUNCATED SOIL - A soil having lost all or part of the upper soil horizon or horizons. Naturally-
formed soils or disturbed soils may be truncated.

TURBELLARIANS - Any of a class Turbellaria of mostly aquatic and free-living  flat worms, but also
inhabiting moist soil, especially small Turbellaria. See soil mesofauna.

UNCONTROLLED HAZARDOUS WASTE DISPOSAL SITES - Refers to a site where hazardous
wastes have been disposed or spilled in such a way as to pose a threat to human welfare or the
environment. Also call abandoned or inactive hazardous waste sites.

UNDERGROUND RUNOFF (SEEPAGE) - Water that seeps toward stream channels after infiltration
into the ground.

UNDERGROUND STORAGE TANK (UST) - (i) A tank located all or partially  underground that is
designed to hold  gasoline or other petroleum products or chemical solutions, (ii) One or more tanks,
including underground connective piping, that store "regulated substances" and that are more than 10
percent below the surface of the ground. Regulated substances include hazardous chemical products
regulated under CERCLA and petroleum products. USTs are regulated under Subtitle I of RCRA;
however, underground tanks containing hazardous wastes continue to be regulated under Subtitle C
of RCRA.

UNIVERSAL SOIL LOSS EQUATION (USLE) - An equation for predicting A,  the average annual soil
loss in mass per unit area per year,  and is defined as A = RKLSPC, where R is the rainfall factor, K is
the soil erodibility factor, L is the length of slope, S is the percent slope, P is the conservation practice
factor, and C is the cropping and management  factor.

UNPRODUCTIVE SOIL - A soil in which the chemical, physical, and biological  conditions are
unfavorable for the economic production of crops  suited to a particular area.

UNSATURATED FLOW - The movement of water in soil in which the pores are not completely filled
with water. See hydraulic conductivity, unsaturated.

UNSATURATED ZONE - (i) The zone or layer of aerated soil; pore space is not filled with water or
other liquids; (ii) The area above the water table where the soil pores are not fully saturated, although
some water may be present.  Also called the vadose zone.
Guide to Site and Soil Description              B-75

-------
                                                                                 Appendix B
UNSATURATED ZONE THICKNESS - The width of the zone between the land surface and the water
table, including the root zone, intermediate zone, and capillary fringe. Value usually obtained by
drilling and analyzing soil cores at various site locations. Also see saturated zone thickness.

URBAN LAND - Areas so altered or obstructed by urban works or structures that identification of soils
is not feasible. (Considered by Soil Science Society of America Glossary as a miscellaneous area.)

URBAN RUNOFF - Storm water from city streets and adjacent domestic or commercial properties that
may carry pollutants of various kinds into the sewer systems and/or receiving waters.

VADOSE WATER - See water table, perched,

VADOSE ZONE - The region or depth  extending from the approximate ground surface to the upper
surface of the principal water-bearing formation. See unsaturated zone.

VALENCE - (i) The  relative ability of a substance to react or combine, (ii) A positive number that
characterizes the combining power of an element for other elements.

VAPOR PRESSURE - The pressure exerted by the vapor over a liquid once evaporation and
condensation have  come to equilibrium.

VAPORIZATION - The escape of molecules from liquid or solid phase to the gas phase, e.g., release
of water (and solutes) from the aqueous soil phase to the gaseous phase.

VEGETATION - The nature, kind, extent, and distribution of plants and plant cover for a given,
designated site.  Also see ground cover.

VIRUS - The smallest form of microorganisms capable of causing disease. Sometimes included with
the soil microbiota,  although submicroscopic in size.  Also see soil microbiota.

VISCOSITY - The resistance of a liquid to flow, e.g.,  a soil solution saturated with organics is more
resistant to flow  (more viscous) than an unsaturated solution.

VISUAL OBSERVATIONS, Superfund  - Observations, usually performed by an Initial Entry Team, that
would help in evaluating site hazards. Some examples are dead plants, dead fish or other animals;
land features; wind  direction; labels on containers indicating explosive, flammable, toxic or corrosive
materials; conditions conducive to splash or contact with unconfined liquids, sludges, or solids, and
other general conditions.

VOID RATIO - The  ratio of the volume  of soil pore (or void) space to the solid-particle volume.

VOIDS - See soil pores.
Guide to Site and Soil Description              B-76

-------
                                                                                Appendix B
VOLATILE CONTAMINANTS - Chemicals characterized by low boiling points and high vapor
pressures.

VOCA - See volatile organic compounds.

VOLATILE ORGANIC COMPOUNDS (VOCA) - (i) Any organic compound that participates in
atmospheric photochemical reactions, except those designated by the EPA Administrator as having
negligible reactivity, (ii) Those organic compounds amenable to analysis by the purge and trap
technique; also called purgable compounds. See CLP (and also refer to its Statement of Work), and
organic chemical/compounds.

VOLATILIZATION - The conversion of a chemical substance from a liquid or solid state to a gaseous
or vapor state by the application of heat, by reduction of pressure, or a combination of both. Also
called vaporization.

VULNERABLE ZONE - An area over which the airborne concentration of a chemical involved in an
accidental release could reach the level of concern.

WASTE - A variety of unwanted materials resulting from industrial, commercial, mining, or agriculture
operations and processes, and places  of human or animal origin; can be any solid, liquid, semisolid,
or contained gaseous materials or substance resulting from production of chemicals.

WASTE ACCUMULATION - The progressive increase in the content of waste substances or agents in
organisms or media through successive or continuous deposit, ingestion, secretion or exposure, and
its retention because of insufficient removal or elimination.

WASTE CHARACTERISTIC  - Any one  of the four categories used in defining hazardous waste:
ignitability, corrosivity, reactivity, and toxicity.

WASTE CHARACTERIZATION - For a  RCRA Part B Permit Application, information is needed that
includes a waste  inventory and characterization (types, volumes, and physical, chemical and biological
characteristics); sampling and analysis  of waste streams for hazardous constituents; background data
and documentation if wastes are to be  "delisted," and the waste analysis plan.

WASTE CONCENTRATION - The result of the process of waste accumulation; the accumulated
content in proportion to the total mass  of the receiving media or organism (See waste accumulation.)

WASTE DESCRIPTION - A description of the contamination at the site, including kinds of
contamination, concentrations and distribution of contaminants, and environmental medium
contaminated at the site.
Guide to Site and Soil Description              B-77

-------
                                                                                Appendix B
WASTE DISPOSAL SITE SAFEGUARDS - Methods or means used to minimize harmful environmental
effects at disposal sites: synthetic liners, leachate detection systems,  runoff controls, and ground
water monitoring systems.

WASTE LAND - Land not generally suitable for or capable of producing materials or services of value.
Usually defined within an agricultural use context.

WASTE MANAGEMENT - The systematic control of the collection, source separation, storage,
transportation, processing, treatment, recovery and disposal of hazardous waste.

WASTE MATERIALS - Waste matter of any kind or description, including, but not limited to solid
waste, semisolid and liquid waste,  garbage, sludge, munitions; radiological, chemical and warfare
agents; radioactive materials, chemicals, biologicals, laboratory, surgical and  institutional materials;
industrial, commercial, mining, municipal, agricultural, and other wastes including  discarded
equipment and excavation debris.

WASTE MINIMIZATION, Superfund  - Introduced in the 1984 Hazardous and Solid Waste
Amendments  (HSWA) to RCRA as a  method of pollution prevention. It focuses on reducing hazardous
waste generation and output at the source to avoid subsequent handling, treatment and disposal.

WASTE PILE  - (i) Any noncontainerized accumulation of solid, nonflowing hazardous waste that is
used for treatment or storage; (ii) Temporary storage of any solid  waste.

WASTE SITE  - An area or location in which wastes are deposited. See  waste and site.

WASTE SITE  DISPOSAL METHODS - Underground storage tanks (USTs), deep-well injection,  land
treatment, recycling and reuse (resource recovery), and "midnight dumping" - an illegal and unsafe
method of disposal.

WASTE STABILIZATION AND SOLIDIFICATION - Waste mixed with  agents that physically immobilize
or chemically  precipitate constituents for RCRA corrective action;  applied primarily to metals and with
mixed results  when used to treat organics.

WASTE STORAGE - The holding of hazardous waste for a temporary period, at the end of which the
hazardous waste is treated, disposed of, or stored elsewhere. Facilities are required to  have a RCRA
permit for storage of hazardous waste for more than 90 days does not require a RCRA permit.

WASTE SUBSTANCE - (i) Waste matter of particles of definite chemical composition; (ii) Physical
material from which a waste is made. See waste materials.

WASTE TREATMENT - Any method, technique, or process that is applied to a waste after the waste
has been generated, for the purposes of rendering it less hazardous.
Guide to Site and Soil Description             B-78

-------
                                                                                Appendix B
WASTEWATER - The spent or used water which carries dissolved or suspended solids from industry,
commercial enterprises, agriculture, farms, homes, and urban areas. See liquid waste.

WATER POLLUTION - The addition to water of any material or substance which alters the physical,
chemical, or biological properties of the water and renders it less acceptable for use, e.g., soil water
pollution.

WATER-STABLE AGGREGATE - A soil aggregate that is stable to the action of water, e.g., rainfall, or
agitation, as in wet sieve analysis, a mechanical analysis of soil.

WATER RIGHTS - Laws and regulations concerning the use of water, usually for irrigation purposes.

WATER TABLE - The upper surface of ground water or that level in the ground where the water is at
atmospheric pressure.

WATER TABLE, PERCHED - The water table of a saturated layer of soil which is separated from an
underlying saturated layer by an unsaturated layer (vadose water).

WEATHER - See climate and weather.

WEATHERING - All physical and chemical changes produced in rocks,  at or near the earth's surface,
by atmospheric agents.

WETLAND - An area of land that has hydric soils and hydrophytic vegetation. See hydric soils.

WET SIEVE ANALYSIS - A method used to determine soil aggregate size and stability; the primary
factor governing the wet stability of aggregates is generally the method  of wetting.

WETTING ZONE - A zone in soil following infiltration of water (or chemical) in which soil wetness
decreases with depth and at a steeping gradient down to a discernible wetting front boundary
between wet and dry soil.

WILTING POINT - See permanent wilting point.

WIND - The natural and relatively horizontal movement of air.

WIND SPEED AND DIRECTION - Natural movement of air of any velocity. Speed:  The velocity of the
wind measured in knots or miles per hour. Direction: One  or more of sixteen points of the compass
with relation to the point of observation of the wind.

WINDBREAK - A barrier erected or planted to absorb and/or deflect some of the wind force and thus
lower the wind velocity on  the leeward side of the barrier. Used to protect crops, soil, personnel, or
other parts of the environment from the effects of wind.
Guide to Site and Soil Description             B-79

-------
                                                                                  Appendix B
WIND EROSION EQUATION - An equation for predicting E, the average annual soil loss due to wind
in mass per unit per year, and is defined as £ = IKCLV, where / is the soil credibility factor, K is the
soil ridge roughness factor, C is the local climatic factor, L is the field width, and V is the vegetative
factor.

WORK PARTY, Superfund - A minimum of two individuals who  perform onsite task necessary to fulfill
the objectives of the investigation, e.g., obtaining samples of soils, air or water, or determining the
location of monitoring wells.

XENOBIOTIC - A compound foreign to biological systems. Often refers to human-made compounds
that are resistant or recalcitrant to biodegradation and/or decomposition.  See recalcitrant molecules.

XERIC SOILS - Soils with a limited amount of water present, and water  not occurring at optimum
periods for plant growth. Also see soil moisture (water) content.

YEASTS - Minute fungi, especially Saccharomyces cerevisia, usually having little or no mycelia (thread-
like structures) and reproducing by budding. Any of the various similar fungi,  especially orders
Endomycetales and  Moniliales.

ZEOLITES - Any  of the hydrous silicates, natural or synthetic.  Used in water softening and as
adsorbents and catalysts. Important in the  immobilization of specific elements.

ZYMOGENOUS MICROBIOTA - Microorganisms found in soils in larger numbers  immediately after the
addition of easily decomposable organic material, including certain  contaminant organics.
Guide to Site and Soil Description              B-80

-------
                              APPENDIX C
  EXAMPLE OF SOIL DESCRIPTION FORM MODIFICATION FROM SOIL CONSERVATION




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-------
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-------
BASE PAGE CODES

Slope Shape (U/A)
1     convex
2     plane
3     concave
4     undulating
5     complex
Geomorphic Component (GM)
1     interfluve
2     head elope
3     side elope
4     nose elope
Hillslope Component (HS)
1     summit
2     shoulder
3     back slope
4     foot slope
5     toe slope
Slope Aspect (ASP)
45    northeast
90    east
135   southeast
180   south
225   southwest
270   west
315   northwest
0     north

Major Landform (MAJ)
BA   Badlands
BI    Barrier Island
BO   Bolson
CA   Canyon
CF   Coalescent Fan Piedmont
CP   Coastal Plain
DF   Drumlin Field
DP   Deeply Disected Plateau
FH   Foothills
GF   Glaciofluvial Landform
GU   Glaciated Upland
HH   High Hills
HI    Hills
KP   Karst Plain
LP    Lake Plain
LU   Level or Undulating Upland
LV   Lava Plain
MO   Mountains
MV   Mountain Valley
PI    Piedmonts
PL    Plains
FT    Plateau
RV   River Valley
SB   Semibolson
SH   Sandhills
TA    Tableland
VM   Volcanic Mountains
 Local Landform (LOG)
 AF   Alluvial Fan
 AP   Alluvial Flat (plain)
 BE   Beach
 BF   Barrier Flat
 BO   Bog
 BS   Backswamp
 BT   Beach Terrace
 BU   Butte
 CB   Carolina Bay
 CO   Cove
 CR   Crater
 CU   Cuesta
 DE   Delta
 00   Dome
 DR   Drumlin
 DU   Dune
 EK   Esker
 EM   End Moraine
 ES   Escarpment
 FE   Felsenmeer
 FP   Flood Plain
 FT   Fluvial Terrace
 FJ   Fjord
 GM   Ground Moraine
 HO   Hogback
 HS   Hillside
 KA   Kame
 KE   Kettle
 LS   Low Sand Ridge
 LT   Lake Terrace
 MA   Marsh
 ME   Mesa
 MO   Mountainside
 MT   Marine Terrace
 OP   Outwash Plain
 OT   Outwash Terrace
 OX   Oxbow
 PE   Pediment
 PL   Playa
 RI   Ridge
 SB   Structural Bench
 SI   Sink
 SL   Slough
 SM   Salt Marsh
 SW   Swamp
 VC   Volcanic Cone
 VS   Valleyside

 Moisture Regime (MST RGE)
 AQ   aquic
 AR   aridic
 PA   peraquic
 PU   perudic
 TO   torric
 UD   udic
 US   ustic
 XE   xeric

 Kind of Watertable (KD)
0     none
2     perched
3     apparent
4     ground
Land Use (LU)
A    abandonded cropland
C    cropland
E    forest land grazed
F    forest land not grazed
G    pasture land and native
      pasture
H    horticultural land
I     cropland Irrigated
J     hayland
L    waste disposal land
N    barren land
O    other
P    rangeland grazed
Q    wetlands drained
R    wetlands
S    rangeland not  grazed
T    tundra
U    urban and built-up land

Stoniness Class (ST)
0     class 0
1     class 1
2     class 2
3     class 3
4     class 4
5     class 5

Hydraulic Conductivity Class
(HC)
1     very slow
2     slow
3     moderately slow
4     moderate
5     moderately rapid
6     rapid
7     very rapid

Drainage Class (DR)
1     very poorly drained
2     poorly drained
3     somewhat poorly drained
4     moderately well drained
5     well drained
6     somewhat excessively
     drained
7    excessively drained

Parent Material
Bedrock Inclination (B)
1     < 5 degree inclination
2    5-30 degree inclination
3     > 30 degree inclination
                                                 C-5

-------
Parent Material Mode of Deposition
(M)
A     alluvium
D     glacial drift
E     eolian
F     mine spoil and earth fill
G     glacial outwash
H     volcanic ash
I     lacustrine sands
J     lacustrine silts
K     lacustrine clays
L     lacustrine
M     marine
N     marine sands
O     organic
P     marina silts
Q     marina clays
R     solid rock
S     eolian-sand
T     glacial till
U     unconsolidated sediments
V     local colluvium
W    loess
X     residuum
Y     solifluctate
Z     estuarine

Parent Material Origin (OR1G)
AO   sandstone unspecified
A1    sandstone-noncalcareous
A2   arkosic-sandstone
A4   sandstone-calcareous
BO   interbedded sedimentary
      unspecified
B1    limestone-sandstone-shale
B2   limestone-sandstone
B3   limestone-shale
B4   limestone-siltstone
B5   sandstone-shale
B6   sandstone-siltstone
B7   shale-siltstone
CO   conglomerate unspecified
C1   conglomeratB-noncalcareous
C2   conglomerate-calcareous
EO   ejecta-ash unspecified
E1    acidic-ash
E2   basic-ash
E3   basaltic-ash
E4   andesitic-ash
E5   cinders
E6   pumice
E7   scoria
E8   volcanic bombs
HO   shale unspecified
H1   shale-noncateareous
H2   shale-calcareous
H3   shale-clay
10    igneous unspecified
11    igneous-coarse (or intrusive)
12    igneous-basic (eg., gabbro)
13    igneous-intermediate (eg.,
      diorite)
14    igneous-granite
IS    igneous-fine (or extrusive)
16    igneous-basalt
17    igneous-andesite
18    Igneous-acid (eg., rhyolite)
19    IgneousHiltrabasic
KO    organic unspecified
K1    mossy material
K2    herbaceous material
K3    woody material unspecified
K4    wood fragments
Parent Material Origin (cont.)
K5    togs and stumps
K6    charcoal
K7    coal
LO    limestone unspecified
U    chalk
12    marble
L3    dolomite
L4    limestone-phosphatlc
L5    limestone-arenaceous
L6    limestone-argillaceous
L7    limestone-cherty
MO    metamorphic unspecified
M1    gneiss unspecified
M2    gneiss-acidic
M3    gneiss-basic
M4    serpentine
MS    schist unspecified
M6    schist-acidic
M7    schist-basic
M8    slate
M9    quartzite
PO    pyroclastic unspecified
P1    tuff unspecified
P2    tuff-acidic
P3    tuff-basic
P4    volcanic breccia unspecified
P5    breccia-acidic
P6    breccia-basic
P7    tuff-breccia
P8    aa
P9    pahoehoe
SO    sedimentary unspecified
31    marl
52    glauconite
TO    siltstone unspecified
T1    siltstone-noncalcareous
T2    siltstone-calcareous
YO    mixed unspecifed
Y1    mixed-noncalcareous
Y2    mixed-calcareous
Y4    mixed-igneous-metamorphic &
      sed.
Y5    mixed-igneous &  metamorphic
Y6    mixed-igneous &  sedimentary
Y7    mixad-metamorphic &
      sedimentary
MS   meta-sedimentary

Bedrock fracture (BR)
1     < 10 cm between fractures
2     10 to 45 cm between fractures
3     45 cm to 1.0 m between
      fractures
4     1.0 to 2.0 m between fractures
5     > 2.0 m between fractures

Hydrologic  group (HG)
A    > 6 Inches/hour
B    0.6-6 Inches/hour
C    0.06 • 0.6 inchesd/hour
D    < 0.06 Inches/hour

Erosion Class (ER)
0    none
1    slight
2    moderate
3    severe

Runoff Class (RO)
1    none
2    ponded
3    very slow
4    slow
5    rapid
6    moderate
7    very rapid

Flooding and Ponding, frequency
(FF/PF)
NO  none
RA  rare
OC  occasional
FH  frequent
CO  common

Diagnostic Features (KND)
A    anthropic
B    cambic
C    calcic
D    durinodes
E    petrocalcic
F    fragipan
G    gypsic
H    histic
I     sombric
J    petrogypsic
K    placic
L    lithic contact
M    mollic
N    natric
0    ochric
P    plaggen
Q    albic
R    argic
S    spodic
T    argillic
U    umbric
V     sulfuric
W   paralithic contact
X    oxic
Y     salic
2    duripan
1    kandic
                                                C-6

-------
HORIZON CODES
Color location (LOG)
0     not given
1     Interior
2     exterior
3     crushed
4     dithtonite-citrate pratreated
S     after exposure to air
6     after ignition
7     pyrophosprtate extract

Boundary distinctness
A     abrupt
C     clear
D     diffuse
G     gradual

Boundary topography
8     broken
I     irregular
S     smooth
W    wavy

Texture class (CLASS)
C     clay
CE   coprogenous earth
CINO cinders
CL   clay loam
COS  coarse sand
COSL coarse sandy loam
CSCL coarse sandy clay loam
DE   diatomaceous earth
FB   fibric material
FM   fragment a I material
FS   fine sand
FSL   fine sandy loam
G     gravel
GYP  gypsiferous earth
ICE   ice or frozen soil
L     loam
LCOS loamy coarse sand
LFS   loamy fine sand
LS   loamy sand
LVFS  loamy very fine sand
MARL marl
MPT  mucky peat
MUCKmuck
OPWD oxide protected  weathered
      bedrock
PDOMpartially decomposed organics
PEAT  peat
S     sand
SC   sandy clay
SCL   sandy clay  loam
S3   sand and gravel
SI    silt
SIC   silty clay
SICL  silty clay loam
SIL   silt loam
SL   sandy loam
SP   sapric material
U     unkown texture
UDOMundecomposed organics
UWB  unweathered bedrock
 VAR  variable
 VFS  very fine sand
 VFSL very fine sandy loam
 WB  weathered bedrock

 Texture modifier (MOO)
 BY   bouldery
 BYV  very bouldery
 BYX  extremely bouldery
 CB   cobbly
 CBA  angular cobbly
 CSV  very cobbly
 CBX  extremely cobbly
 CN   channery
 CNV  very channery
 CNX  extremely channery
 FL    flaggy
 FLV  very flaggy
 FLX  extremely flaggy
 GR   gravelly
 GRC  coarse gravelly
 GRF  fine gravelly
 GRV  very gravelly
 GRX  extremely gravelly
 ST    stony
 STV  very stony
 STX  xtremely stony

 Structure grade (GRD)
 0     structureless
 1     weak
 2     moderate
 3     strong
 4     very strong
 5     weak and moderate
 6     moderate and strong

 Structure size (SZ)
 CO   coarse
 CV   coarse and very coarse
 F     fine
 FF    very fine and fine
 FM   fine and medium
 M     medium
 MC   medium and coarse
 TK    thick
 TN    thin
 VC    very coarse
 VF    very fine
 VK    very thick
 VN    very thin

 Structure shape (SHP)
 ABK  angular blocky
 BK    blocky
 CDY  cloddy
 COL  columnar
 CR    crumb
 GR    granular
 LP    lenticular
 MA   massive
 PL    platy
 PR    prismatic
SBK  subangular blocky
SGR  single grain
WEG  wedge
 Mottle abundance (AS)
 F     few
 C    common
 M    many

 Mottle size (SZ)
 1     fine
 12    fine and medium
 13    medium and coarse
 2     medium
 3     coarse
 Mottle distinctness
 D    distinct
 F     faint
 P     prominent
 Kind of field measurement (KND)
 CL   clay
 PB   Bromthymol blue
 PC   Cresol red
 PG   Bromcresol green
 PH   hellige-truog
 PL   LaMotte-Morgan
 PP   Phenol red
 PR   Chkxophenol red
 PS   soiltest
 PT   Thymol-blue
 PY   pH Ydrion
 SA   sand
 SC   coarse and very coarse
    sand
 SF   fine sand
 SI    silt
 SM   medium sand
 SV   very fine sand
 OB   fiber unrubbed
 OR   rubbed fiber

 Hydraulic conductivity class
 1     Very slow
 2     slow
 3     Moderately slow
 4     Moderate
 5     Moderately rapid
 6     Rapid
 7     Very rapid

 Root quantity (QT)
 VF    very few
 FF    very few to few
 F     few
 FC   few to common
 C     common
 CM   common to many
 M     many

 Root size (SZ)
 1     fine l-2mm
 11     very fine  and  fine
 12    fine and medium
 13    fine to coarse
2     medium 2-5mm
23    medium and coarse
3     coarse > 5mm
V1    very fine  < 1mm
                                               C-7

-------
Root location (LOG)
C     in crack*
M     in mat at top of horizon
P     between peda
S     matted around stones
T     throughout

Shape of pore (SHP)
IE    filled with coarse material
IF    void between rock fragments
IR    interstitial
IT    interstitial and tubular
TC    continuous tubular
TD    discontinuous tubular
TE    dendritic tubular
TS    constricted tubular
71)    tubular
VS    vesicular
VT    vesicular and tubular

Quantity of pores (QT)
VF    very few
FF    very few to few
F     few
FC    few to common
C     common
CM   common to many
M     many

Size of pore (SZ)
1     fine ,05-2mm
11     very fine and fine
12    fine and medium
13    fine to coarse
2     medium 2-5mm
23    medium and  coarse
3     coarse > 5mm
V1    very fine < .05mm

Pore Continuity (CN)
L     Low
M     Moderate
H     High

Kind of concentration (KND)
A2    clay bodies
B1    barite crystals
B2    soft masses of barite
C1    calcite  crystals
C2    soft masses of lime
C3    lime concretions
C4    lime nodules
01    mica flakes
D2    soft dark masses
D3    dark concretions
D4    dark nodules
E3    gibbsite concretions
E4    gibbsite nodules
F1    plinthite segregations
F2    soft masses of iron
F3    iron concretions
F4    ironstone nodules
G1    gypsum crystals
G2    masses of gypsum
G3    nests of gypsum
G4    gypsum threads
H1    halite crystals
H2    salt masses
K2    soft masses of carbonate
K3    carbonate concretions
K4    carbonate nodules
K5    carbonate threads
M1    nonmagnetic shot
M2    soft masaea of iron-
      manganese
M3    iron-manganese concretions
M4    magnetic shot
S1    opal crystals
S2    soft masses of silica
S3    silica concretions
34    durinodea
T2    worm caste
T3    insects casts
T4    worm nodule*

Quantity of concentrations (OT)
VF    very few
FF    very few to few
F     few
FC    few to common
C     common
CM   common to many
M     man

Shape of concentration (SHP)
C     cylindrical
D     dendritic
0     rounded
P     plate like
T     thread*
Z     irregular

Size of concentration (SZ)
1     fine <2mm
12    fine and  medium
2     medium 2-5mm
23    medium and coarse
3     coarse > 5-20mm
34    coarse and very coarse
4     very coarse 20-76mm
45    very coarse and extremely
      coarse
5     extremely coarse > 76mm
Kind of rock fragment (KND)
A     sandstone
8     mixed sedimentary
E     eject*
F     ironstone
H     shale
I     igneous rocks
K     organic fragments
L     limestone
M     metamorphic rocks
0     oxide-protected rock
P     pyroclastic rocks
R     saprolite
S     sedimentary rocks
Y     mixed lithology
                                              C-8
Roundness of rock fragment
(RND)
1       angular
2       subangular
3       subrounded
4       rounded
S       well rounded

Size of rock fragment (SZ)
1       pebble*
2       cobbles
3       stone*
4       boulder*
S       charmers
6       flagstones

-------
                                                                APPENDIX D

                                  METHODS  FOR DETERMINATION OF SITE AND SOIL PARAMETERS
                                          Adapted from Russell Boulding  (Eastern Research Group)
          SOIL PARAMETER
                                            FIELD DETERMINATION
                                                                                  LABORATORY METHOD
                                                                                 CALCULATION/LOOKUP
1.  WATER BUDGET
Precipitation
Sacramento gage  (accumulated
precipitation, manual  recording),
weighing gage (continuous
measurement,  mechanical
recording),  or tipping-bucket gage
(continuous  measurement with
electronic recording)--Finkelstein
et al.  (1983).
                                     Precipitation data collected by
                                     National Weather Service or other
                                     source  for  area near site.
                                     Interpolation using published
                                     maps  of precipitation data.
InfiItration
Cylinder infiItrometer  (Bouwer,
1986) and sprinkler  infiItrometer
(Peterson and  Bubenzer  (1986).
                                     Methods  available for estimating
                                     infiltration of small watersheds
                                     (Dunne and  Leopold, 1978), large
                                     watersheds  (Musgrave and Ho I tan
                                     (1964).   Infiltration equations
                                     can be used using field-measured
                                     or literature estimates (Green
                                     and Ampt, 1911; Philip 1957).
Evaporation
Class-A Pan evaporation  from
surface of  free  liquid (Veihmeyer,
1964;  NWS 1972)  direct measurement
of bare soil  evaporation using a
weighing lysimeter  (USGS,  1977).
                                     Interpolation using maps showing
                                     average  evaporation.
Evapo-transpiration
Direct field methods  include use
of lysimeters (Boast,  1986;
Sharma,  1985; Veihmeyer,  1964),
soil moisture sampling (Veihmeyer,
1964), and potential
evapotranspirimeters  (Thornthwaite
and Mather,  1957).   Indirect field
methods include chloride  tracer
(Sharma,  1985) and  ground-water
fluctuation (Davis  and Dewiest,
1966).
Chloride tracer  method  requires
laboratory analyses  (Sharma,
1985).
Indirect micrometeorologic methods
include the profile  method
(Sharma, 1985) and energy
budget/Bowen ratio,  eddy
covariance methods and  Penman
equation (Veihmeyer,  1964; Sharma
1985).
Three commonly used  empirical
equations are the  Thornthwaite
equation (Veihmeyer,  1964; Sharma
1985),  and the Btaney-Criddle
equation (Stephens and  Stewart,
1964);  and the Jensen-Haise
equation (Jensen and Haise,
1963).
Surface Runoff
Field observations  using  SCS soil
runoff classes allows  qualitative
estimation (see Section 12.e in
Boulding,  1991).
                                     Can be calculated  from
                                     precipitation,  soil moisture and
                                     infiltration  data. SCS soil
                                     series interpretation sheets
                                     provide hydrologic soil group for
                                     surface runoff  calculations using
                                     the SCS curve runoff method (USDA
                                     SCS, 1975).                  	

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                              METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
SOIL PARAMETER
2. OTHER CLIMATE /WEATHER PARAMETERS
Air Temperature
Wind Speed
Humidity
Insolation
FIELD DETERMINATION

Thermometry (Taylor and Jackson,
1986), see also Section 2.12f in
Boulding, 1991).
Cup or propeller anemometer
(Finkelstein et al. 1983; Kite,
1979).
Use sling psych rometer for
obtaining wet-bulb and dry-bulb
air temperatures for calculation
of relative humidity and dew
point.
Thermopile pyranometer or silicon
photovoltaic cell (Thompson, et
al., 1989)
LABORATORY METHOD





CALCULATION/LOOKUP

Brown et al. (1983) provide maps
with temperature data. See also,
National Climatic Data Center
(1983) for possible sources.
Schroeder et al. (1983) include
insolation data for 102 cities.

See National Climatic Data Center
(1983) for possible sources.
See National Climatic Data Center
(1983) for possible sources.
Schroeder et al. (1983) include
insolation data for 102 cities.
o
ro

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                               METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
SOIL PARAMETER
3. GEOMORPHOLOGY
Slope (%)
Slope form/ landscape position
Credibility
Water Erosion (USLE or RUSLE)
Wind Erosion
FIELD DETERMINATION

Measure slope gradient and length
for erosion modeling.
Observation of slope form and
shape may help in location of
areas where contaminants have been
concentrated by surface erosion.
Field measurement of slope, field
length, cover type.
Measurement/survey of slope (in.
ft. rise/ft, run or %), length of
field and vegetation cover.
Measure field length along
prevailing wind direction.
LABORATORY METHOD






CALCULATION/LOOKUP

Can be measured from site
topographic surveys.
The surface hydrology of hill
slope systems is generalized by
the SCS curve number and
hydrologic soil groups (see I.e
above) .
Estimated using standard
equations and graphs (Isrealsen
et al., 1980). Soil data can be
obtained from local SCS office.
The universal soil loss equation
(USLE) (Wischmeier and Smith,
1978); revised version (Renard et
al. 1991) and the new generation
WEPP (Laflen et al. (1991). See
Mills et al. (1985) and U.S. EPA
(1988d) for use guidance.
SCS wind erosion equation (WEQ)
(Woodruff and Siddoway, 1965;
Israel sen et al. 1980). Cowherd
et al. (1985) describe method for
rapid evaluation of particles
from a Superfund site.
o
d)

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METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
SOIL PARAMETER
5. SURFACE HYDROLOGY
Surface Streams
F 1 ood P I a i ns/ F requency/Dura t i on
Water Bodies
6. SITE BIOTA
Vegetative Cover
FIELD DETERMINATION

Field observation of drainage way
location, and whether they are
ephemeral, intermittent or
perennial.
Engineering and hydro logic field
measurements to estimate extent
and frequency of flooding.
Map location and measure size, and
variations in water levels over
time.

Map current vegetation types.
Vogel (1987) describes procedures
for mapping and sampling
vegetation. USDA can aid in
identification of unknown plant
species.
LABORATORY METHOD






CALCULATION/LOOKUP

Areal photographs, topographic
and other types of maps.
Check for availability of flood
hazard boundary maps prepared for
the Federal Emergency Management
Agency and the Federal Insurance
Administration.
Areal photographs, topographic
and other types of maps.

Air photographs taken at
different years can be used to
evaluate changes in vegetation
over time. Available from ASCS,
SCS.

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                               METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
SOIL PARAMETER
Horizons
Texture
Color
Porosity (pore volume)
11. ZONES OF INCREASED SECONDARY
POROSITY/PERMEABILITY
Structure
Roots
Lateral Features
Sedimentary Features
FIELD DETERMINATION
Soil pits dug with backhoe are
best. If safety and cost are a
concern, soi I cores can be
collected with a tube- type
sampler.
Field determination by feel to
estimate percent silt, sand and
clay. Collect composite sample of
each soil horizon for laboratory
determination.
Soil colors can be precisely
described according to hue, value,
and chroma using Munsell Soil
color charts.
SCS method for description of pore
size and distribution can provide
insight into paths for contaminant
transport.

Use SCS classification system and
description procedures (Boulding
1991).
Use SCS classification system and
description procedures (Boulding,
1991).
Use SCS classification system and
description procedures (Boulding,
1991).
Describe type, thickness, and
orientation (Boulding, 1991).
LABORATORY METHOD
Laboratory texture analyses and
chemical tests may be required to
confirm or refine horizon breaks
defined in the field.
ASTM 0 522-63 Method for Particle
Analysis of Soils. Sieve analysis
better at hazardous waste site
because organics can affect
hydrometer analysis (U.S. EPA,
1987a).
It may be useful to record color
or air-drying samples.
Gas pycnometer (Danielson and
Sutherland, 1986).



Clay mineral identification may be
desirable when stress formations
are observed (see clay mineralogy)

CALCULATION/LOOKUP
SCS soil survey, if available
will provide guidance in types of
soil horizons that are likely to
be encountered.
SCS soil survey, if available
will indicate ranges of texture
that can be expected in different
horizons for specific soil
series.
SCS soil series description
sheets indicate typical ranges of
colors of different soil
horizons.
Calculated from particle and bulk
densities (Danielson and
Sutherland, 1986).





O
en

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                               METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
SOIL PARAMETER
12. ZONES OF REDUCED
POROSITY/PERMEABILITY
Genetic Horizons
Rupture Resistance (consistency)
Bulk Density
Root Restriction Depth
13. SOIL ENGINEERING
PROPERTIES/PARAMETERS
Compaction
Corrosivity
FIELD DETERMINATION

Use SCS criteria and description
procedures. See Table 2-4 in
Boulding (1991) for cementation
test.
Use SCS field tests and
description procedures. See Table
2-4 in Boulding (1991).
Neutron probe (ASTM, 1981); gamma
radiation (Blake and Hartge,
1986).
Use SCS criteria and description
procedures (Boulding, 1991).

Not amenable to field estimation.
Can be inferred from field
estimated or measured properties.
SW 846 (US EPA, 1986b) requires a
sample of liquid waste for pH (<2
or > 12.5) and corrosivity toward
steel.
LABORATORY METHOD

See discussion of rupture
resistance below.
Laboratory testing can provide
more precise classification of
samples. Cementation test
procedure can be more easily done
in the laboratory.
Coring or excavation for lab
analysis (Blake and Hartge, 1986).


Proctor density test or moisture
density test (ASTM D-698) used to
determine moisture content at
which maximum density occurs with
compaction.
SW 846 (US EPA, 1986b) uses method
1110 to measure the corrosivity
toward steel of both aqueous and
nonaqueous liquid wastes.
CALCULATION/VALUE

SCS soil survey will identify
soil series with horizons of
reduced permeabi I i ty .

SCS soil series interpretation
records contain estimated ranges
of bulk density.



SCS soil series interpretation
sheets give corrosivity ratings
for steel and concrete. USDA SCS
(1983) provides quantitative
criteria for rating soil
corrosion potential for uncoated
steel and cement based on
parameters mentioned in column 1.
a
05

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                              METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
          SOIL PARAMETER
                                            FIELD  DETERMINATION
                                                                                  LABORATORY METHOD
                                                                                 CALCULATION/LOOKUP
14.  SOIL WATER STATE
Moisture Content
Carbide gravimetric methods can be
used in field (Wilson,  1981).
Most common indirect  field method
is neutron scattering (van Bavel,
1963, Gardner,  1986).   Other
indirect methods  include
electrical conductivity and
capacitance,  and  gamma  ray or
neutron attenuation (Gardner,
1986).
Gravimetric analysis  of  field-
collected samples  is  the most
accurate method (Gardner,  1986).
Can be inferred by  measuring
water potential in  the field or
laboratory (see 9.b below) and
using moisture retention curves
(see 9.c below).
Water Potential
Water potential  in  saturated soils
is measured using piezometry
(Reeve,  1986).   The most common
field method for measuring
negative potential  is  tensiometry
(Cassel  and Klute,  1986).  Field
psychrometers can also be used
(Rawlins and Campbell, 1986).
Laboratory measurements  of  field
collected samples  at  different
water contents using  tensiometry
(Cassel and Klute  (1986)  or
thermocouple psychrometry (Rawlins
and Campbell) are  usually used  to
measure specific retention  (see
9.c below). Electrical  resistance
and heat dissipation  sensors can
also be used (Campbell  and  Gee
(1986)
Can be inferred from  moisture
retention curve (9.c  below) by
measuring water content of soil
(9.a above).
Available Water Capacity (AWC)
Collection of  soil  samples  just
after the soil has  drained
following a period  of  rain  and
humid weather, after a spring
thaw, or after heavy irrigation
(see Section 1.4.1  in  USDA  SCS,
1971; 1983).        	
Measurement of soil  moisture  at
field capacity and 15-bar  moisture
content, and bulk density  (USDA
SCS, 1983).
SCS soil series interpretation
sheets provide ranges  of
available water capacity  for
individual soil horizons.
Soil Moisture Regime
                                    Not measured in field
                                                                          Usually determined by using
                                                                          climatic and soil data to develop
                                                                          a  monthly soil water balance.
                                                                          SCS  taxonomic classification will
                                                                          indicate the moisture regime of a
                                                                          soil  series.

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                                           METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
                       SOIL PARAMETER
                                                         FIELD DETERMINATION
                                                                                               LABORATORY METHOD
                                                                                                                                   CALCULATION/LOOKUP
             15.  INTERNAL FREE WATER
                  (saturated zone)
Ground-water  monitoring  wells  or
piezometers using EPA  approved
methods (AUer  et al., 1989; Reeve
1986).  Depth,  thickness and
duration (if  perched)  should be
measured.
                                     SCS soil series data sheet
                                     provide estimates of depth,
                                     thickness, and duration of
                                     shallow/perched water tables.
             16.   PERMEABILITY/HYDRAULIC
                  CONDUCTIVITY
             Saturated Hydraulic Conductivity
             (Ksat)
Auger-hole and piezometer methods
(Amoozegar and Warrick,  1986) and
Guelph permeameter  (Reynolds and
Elrick, 1985  and 1986).  SW 846  (US
EPA, 1986b) provides methods
requiring a single  bore  hole or
piezometers;  area I  methods are
included for  reference purposes.
Constant head and falling head
methods (Amoozegar and Warrick,
1986; Klute and Dirksen,  1986).  SW
846 (US EPA, 1986b) details
methods for constant and  falling
head conditions using specific
types of laboratory apparatus and
their applicability to remolded
compacted,  and fine-grained
uncompacted, and coarse-grained
porus media.
O
05
Freeze and Cherry (1979) provide
ranges for different geologic
materials, and USDA SCS (1990)
provides range for Unified soil
texture classes.  SW 846 (US EPA,
1986b) provides calculations,
theory, and measurements for
tests, including  the modified
slug test. Laboratory and field
methods are described to
determine fluid conductivity of
materials used for liners,  caps,
and drains at waste-disposal
facilities as well as materials
composing the local ground water
flow systems.
             Unsaturated Hydraulic  Conductivity
             (Kunsat.)
Constant-head borehole
infiltration (Amoozegar and
Warrick,  1986);  instantaneous
profile,  crust-  and sprinkler-
imposed steady flux methods  (Green
et al.  1986);  air  entry
permeameter (Bouwer,  1966).
Klute and Dirksen (1986)  describe
8 methods, the main ones  being
steady-state head and steady-state
flux control.
Parameter identification uses
results of one field or  lab test
to develop conductivity  over a
range of moisture contents
(Zachmann et al.  1982; Kool  et
al., 1985).   Empirical equations
(Mualem, 1986; van Genuchten,
1980, in press).  SW 846  (US EPA,
1986b) does  not include  methods
for hydraulic conductivity  at
this time because Part 264
permitting standards do  not
require such determinations.

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                               METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
SOIL PARAMETER
17. CONTAMINANT TRANSPORT
IN SOIL WATER
Dispersivity
18. VOLATILIZATION
Air Temperature
Wind Speed
19. GROUND TEMPERATURE
Soil Temperature
Soil Temperature Regime
FIELD DETERMINATION

Any method used to identify zones
of increased permeability (see
Section 5, Table 1). Tracer tests
can be used in the saturated and
unsaturated zone, borehole
flowmeters in the saturated zone.

See climate/weather
See climate/weather

Thermometry (Taylor and Jackson,
1986), see also Section 2.12f in
Boulding, 1991 for estimation of
average annual temperature.
Usually not measured in the field.
LABORATORY METHOD

Use of column and flow- through
tests (Van Genuchten and Wierenga,
1986).

Same as field.


Same as field.

CALCULATION/LOOKUP

Where no data are available
factors for hydrodynamic
dispersion may be estimated for
use in transport modeling.

See climate/weather
See climate/weather

Brown et al. (1983) provide maps
with temperature data.
Usually estimated from climatic
data. Soil temperature regime is
part of the SCS taxonomic
classification of a soil series.
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                                           METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
                       SOIL PARAMETER
                                                         FIELD DETERMINATION
                                                                                               LABORATORY METHOD
                                                                                                                                   CALCULATION/LOOKUP
             20.  SOIL CHEMISTRY
             Organic Carbon/Matter
                                    Color provides a rough indication
                                    of organic matter content of
                                    soils. See also Test 11  in Section
                                    2.8a in Boulding (1991).
                                     Different methods are used to
                                     measure total, inorganic and
                                     organic carbon.  Most involve high
                                     temperature combustion (wet or
                                     dry) and oxidation techniques
                                     (Nelson and Sommers, 1982).  Due
                                     to  difficulty in identifying
                                     natural versus added organic
                                     carbon, correct analysis at
                                     contaminated sites is a problem
                                     (Powell et al., 1989; Powell,
                                     1990).  Characterization of stable
                                     humic substances in OM may be
                                     desirable (Schnitzer, 1982).	
             Odor
                                    Used in ASTM (unified) soil
                                    classification system to identify
                                    organic soils (see Test 11  in
                                    section 2.8a in Boulding,  1991).
O

o
Cation Exchange Capacity
(CEC)
Representative  samples of major
horizons and strata required for
laboratory analysis. Collect
samples in accordance with SW 846
(US EPA, 1986b).
Chapman (1965)  describes standard
methods for measurement of CEC;
Rhoades (1982a) describes special
procedures for  arid  and highly
weathered tropical soils.  Thomas
(1982) describes methods for
determination of total
exchangeable cations. SW 846  (US
EPA, 1986b) methods  9080 and  9081
refer to Chapman (1965).	
Rough estimates  possible  from
particle size distribution and
clay mineralogy.  SW  846 (US EPA,
1986b) uses a sampling plan that
addresses collection,
preservation and handling.
             Soil pH
                                    Measured in field same manner  as
                                    in  laboratory.
                                     Using a glass electrode in an
                                     aqueous slurry (McLean, 1982).  SW
                                     846  (US EPA, 1986b) method 9045 is
                                     an electrometric method for
                                     measuring pH in calcareous and
                                     noncalcareous soils; method also
                                     provided for sample preparation.
                                     SCS  soil  series description will
                                     include pH  class descriptors for
                                     each soil horizon. SW 846 (US
                                     EPA, 1986b) cautions against
                                     errors that may occur when
                                     electrodes  become coated.

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                              METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
          SOIL PARAMETER
                                           FIELD DETERMINATION
                                                                                 LABORATORY METHOD
                                                                                                                    CALCULATION/LOOKUP
SoiI  Oxygen
Platinum or  membrane electrode
methods (Phene,  1986) or use of
field gas chromatograph (Smith and
Arah, 1991).
Same as field.   In saturated
soils,  dissolved oxygen is
analyzed using  EPA 360.1 or 360.2-
-electrometric  membrane electrode
and titrimetric,  modified Winkler
methods (Kopp and McKee, 1983).
Calculated from pE  (Stumm and
Morgan, 1981)  or from aerial
oxygen and soil gas diffusion
rate.
Redox Potential  (Eh)
Platinum electrode used on
lysimeter sample  (ASTM, 1976).
Same as field.
Can be calculated  from
concentration of redox pairs of
oxygen (Stumm and  Morgan, 1981).
Redox Couple Ratios
(waste soil  system)
Lysimeter  or  ground-water samples
for laboratory analysis.
Analysis of concentrations of
redox pairs.   Thompson et al.
(1989) summarize methods for
measurement of redox sensitive
species.	
Clay Mineralogy
See Section  2.15g  in Boulding
(1991).
Thompson et al.  (1989) review 8
methods for analyzing clay
mineralogy.  The most common
methods are X-ray diffraction
(Whittig and Allerdice, 1986), and
scanning electron microscopy
(Goldstein et al. 1981), sometimes
supplemented with chemical
analyses (Jackson et al. 1986).
SCS soil series taxonomic
classification provides a general
idea of clay mineralogy.

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                               METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
SOIL PARAMETER
Other Mineralogy
Salinity
Sodicity/SAR
(sodium adsorption ratio)
Major Cations
Major Anions
Fertility Potential
FIELD DETERMINATION
Hydrochloric acid test for calcium
carbonate; other mineral
concentrations can be identified
visually (see Section 2.15h in
Boulding, 1991).
Measurement of electrical
conductivity of a saturation
extract from soil, or ground-water
sample (Rhoades, 1982b). See also
other methods for measurement of
water flux that sense dissolved
solids (see 13. a)
The surface of sodic soils is
usually discolored by the
dispersed humus carried upward by
capi Uary water.
Collection of samples of soil
solids or ground water for
laboratory analysis required.
Collection of samples of soil
solids or ground water for
laboratory analysis required.
Sampling of soil for laboratory
analysis of nutrients of interest.
LABORATORY METHOD
The most common method for
identification of non-clay
minerals is optical microscopy
(Cady et al. 1986). Nelson (1982)
describe methods for analysis of
carbonate and gypsum. See also
methods for clay mineralogy above.
Same as field.
Analysis of concentrations of
sodium, calcium and magnesium in a
saturation extract. See ***.
Knudsen et al. (1982) describe
methods for analyzing for sodium
and potassium, and Lanyon and
Heald, (1982) for calcium and
magnesium in soil extracts.
Thompson et al. (1989) review 18
recommended methods for analysis
of an ionic species in aqueous
solution, and 21 methods for
anionic species and ammonium ion
in solids.

CALCULATION/LOOKUP
Soils where specific non-clay
minerals form a significant
percentage of the soil texture
are identified in a soil series
taxonomic mineralogy class.
SCS soil series descriptions may
specify soil salinity classes
where soluble minerals are
significant in the soil profile.
SAR is calculated from data on
the amount of sodium, calcium,
and magnesium in the soil (USDA
SCS, 1991).



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                                           METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
                       SOIL PARAMETER
                                                         FIELD DETERMINATION
                                                                                              LABORATORY METHOD
                                                                                 CALCULATION/LOOKUP
             21.   SOIL BIOTA
No standard method  exists.  See
model of remedial technology for
input or remedial evaluation
procedure.	
No standard method exists.  See
model of remedial  technology  for
input or remedial  evaluation
procedure.	
             Enumeration
Special  procedures must be
followed to collect  subsurface
solids samples for laboratory
study that are not contaminated by
microbiota from other sources.
Major types of methods  include
cultures,  microscopic,  chemical
and  radioisotope analyses
(Ghiorse and Wilson,  1988; Page et
al. 1982,  chapters 37 to 40;
Poindexter and Ledbetter, 1986).
             Macrofauna and Mesofauna
O

GO
Record visual  sighting of animals,
evidence of  habitation, tracks,
feeding remains,  distribution and
number of burrows with reference
to source and  extent  of
contamination.
Methods for distribution and
diversity of mesofauna  (Wallwork,
1976). Mites and other  arthropods
(Woolley, 1982)
Consult area biologists on
possible presence of  endangered
species. Enumerate numbers,
distribution,  and kinds of macro-
and mesofauna.  Consult literature
for macro- and mesofauna for site
and soil moisture and thermic
regimes.	
             Microbiota
Record field observations of
microbial  surface crusts,
especially algal-lichen  soil
crusts,  mold growth,  and evidence
of decay.
Soil enzymes (Tabatabai,  1982).
Filamentous fungi  (Parkinson  and
Paul, 1982). Actinomycetes
(Wellington, 1982).  Anaerobic
bacteria and processes (Kaspar  and
Tiedje, 1982).  Soil  bacteria
(Allen, 1957).  Algae (Shields,
1982). Protozoa (Stout et al,
1982).
Enumerate numbers,  kinds,
metabolisms and distribution of
various microbiota.  Consult
literature for microbiota  for
site and soil  moisture  and
thermic regimes.

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                               METHODS FOR DETERMINATION OF SITE AND SOIL PARAMETERS, Continued
SOIL PARAMETER
22. SOIL POLLUTION SITUATION
Toxicity
Reactivity
Corrosivity
Ignitability
Contaminant General Chemical
Properties
Chemical Class
Solubi lity/Miscibility in Water
Special ion
FIELD DETERMINATION
Collection of field samples at
depth and locations specified in
the sampling plans using equipment
and procedures specified in the
soil sampling protocol. Odor may
serve as an indicator of the
presence of organic contaminants.
Qualitative observations of toxic
effects of contaminants on plants
and aquatic organisms may be
observable.
The known or possible presence of
reactive hazardous materials may
require use of respirators and
special protective gear while
sampling.
Field sampling of waste to measure
determine corrosivity may be
required.

Not applicable.
Not applicable.
Not applicable.
Not applicable.
LABORATORY METHOD
Analysis for all constituents that
are suspected of possibly being
present at the site.
If adequate published data are not
available, laboratory toxicity
methods may be required. Norton
et al. (1988) describe available
methods.



Laboratory methods will generally
not be required unless standard
reference books do not contain the
desired data.


See soil chemistry parameters:
redox potential, clay mineralogy,
other mineralogy, salinity, and
sodicity.
CALCULATION/LOOKUP
Any records related to type and
handling of wastes should be
checked in developing the list of
constituents of concern and in
choosing sampling locations.
Norton et al. (1988) and ERG
(1991) discuss various approaches
to evaluate toxicity risk for
ecological systems.



See below for source for specific
parameters.
Various standard chemical
reference sources available.
Water solubility can be estimated
from Kow (octanol/water
partition coefficient), see
Chapter 2 in Lyman et al. (1990).
Phases and species in aqueous
systems under various geochemical
conditions can be estimated using
di st r i but ion-of- species
geochemical models (U.S. EPA,
L1990b, chapter 5).
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                                    TECHNICAL REPORT DATA
                            (Please read Instructions on the reverte before completing)
1. REPORT NO.
  EFA/bOO/4-91/029
                              2.
             3. RECIPIENT'S ACCESSION NO.
                PB92-146 158
4. TITLE AND SUBTITLE
  GUIDE  TO SITE AND SOIL DESCRIPTION  FOR  HAZARDOUS
  WASTE  SITE CHARACTERIZATION  VOLUME 1:  METALS
             5. REPORT DATE
                March 1992
             6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)

   Roy  E.  Cameron
                                                            8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
   Lockheed Engineering & Sciences  Co.
   1050 E.  Flamingo Road
   Las  Vegas,  NV  89119
                                                             10. PROGRAM ELEMENT NO
              11 CONTRACT/GRANT NO.

                LESC  Contract 68-CO-0049
12. SPONSORING AGENCY NAME AND ADDRESS
   Environmental Monitoring Systems  Laboratory - LV, NV
   Office of Research and Development
   U.S.  Environmental Protection  Agency
   Las  Vegas,  NV  89193-3478
                                                             13. TYPE OF REPORT AND PERIOD COVERED
              14 SPONSORING AGENCY CODE

                 EPA 600/07
15. SUPPLEMENTARY NOTES
       This  guide is intended  to  assist  field personnel who must  identify,  describe, and
  interpret  site and soil characteristics  of hazardous waste  sites  where metals contami-
  nation  is  suspected or known.   The  approach presented, including  the  knowledge frames of
  an  expert  system, will be unfamiliar  to  most site investigators.   For developers of
  expert  systems, the Guide should  facilitate standardization of  questions  and responses
  related to soil contamination problems.
       This  guide provides a general  discussion (Section 2) of  the  elements of a back-
  ground  review and an on-site examination of site and soil characteristics essential to
  meeting the needs of these different  data uses.   This general discussion  is followed by
  a catalogue of individual site  (Section  3) and soil (Section  4) characteristics  (e.g.,
  climate and weather, texture and  structure, hydraulic conductivity, slope,  soil
  microorganisms) that should be  investigated during site characterization.  For each
  entry,  the guide describes possible conditions of the characteristic  (e.g., high,
  moderate,  or low; prominent, distinct, or faint) and methods  for  assigning  these condi-
  tions.   References that provide more  detailed information are given for each character-
  istic.   Extensive definitions are provided for describing contaminated sites and soils.
       Supplemental information with  site  characterization data;  a  soil description form;
  and  a summary of methods useful for determination of site and soil parameters
  accompanies Volume 1 and is available  in "A Pocket Field Guide".
17.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                               b.IDENTIFIERS/OPEN ENDED TERMS  c.  COSATi Field/Group
18. DISTRIBUTION STATEMENT


   RELEASE  TO PUBLIC
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