Preparation of Soil Sampling Protocol:  Techniques and Strategies
Environmental Research Center
Las Vegas, NV
May 83
                     U.S. DEPARTMENT OF COMMERCE
                  National Technical Information Service

                                           May 1983

            Benjamin J. Mason
          McLean, Virginia 22101
            under subcontract
       Environmental Research Center
      University of Nevada, Las Vegas
          Las Vegas, Nevada 89154
Cooperative Agreement Number:  CR808529-Q1-2
              Project Officer

            Robert D. Schonbrod
   Exposure Assessment Research Division
Environmental Monitoring Systems Laboratory
          Las Vegas, Nevada 89114
Environmental Monitoring Systems Laboratory
     Office of Research and Development
   U. S. Environmental Protection Agency
          Las Vegas, Nevada 89114

                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)

                ' *   	•» * A C 7

             5 REPORT DATE
                May 1983
7. AUTHORis) Dr.  Benjamin J. Mason
  	McLean.  VA 22101	
                                                           8 PERFORMING ORGANIZATION REPORT NO
 Environmental  Research Center
 University of  Nevada,  Las Vegas
 4505 S. Maryland  Parkway
 Las Vegas, NV  89154
             10. PROGRAM ELEMENT NO.

             11 CONTRACT/GRANT NO.
 Environmental Monitoring Systems Laboratory
 U.S. Environmental  Protection Agency
 P.O. Box 15027
 Las Vegas, NV 89114

          as a product of the Exposure Assessment Research Project

      This report  sets  out a system for developing soil sampling protocols  that
 can be used to meet  the needs of the environmental scientist working under a
 number of situations.   The body of the report  discusses the factors that
 influence the selection of a particular sampling  design and the use of a
 particular sampling  method.  Statistical designs  are discussed along with  the
 appropriate analysis of the data.  Three appendices are included.  One is  a
 djscussion of the steps that must be taken to  arrive at the desirod protocol.
 The remaining appendices present two examples  of  protocols; one fox a shallow
 spill situation and  the second for a deep contamination plume.  A technique
 called kriging is presented as an approach for handling the analysis of data
 collected during  a soil sampling program.  This technique allows the researcher
 to develop maps of the pollution levels and to assign a statistical precision
 to the data at each  point on the map.  The data presented on these two maps can
 be evaluated to identify areas where additional samples are needed to reach a
 desired level of  precision for the area covered by the maps.
                                KEY WORDS AND DOCUMENT ANALYSIS
                                              b.lDENTIFIERS/OPEN ENDED TERMS
                           c. COSATi Field/Group
 Sampling, Investigations,  Soil Surveys,
 Pollutants, Design  Criteria,  Statistical
 monitoring network
 design,  geostatistical

 Release to Public
19. SECURITY CLASS (Tins Report)

20 SECURITY CLASS (Tim page)
EPA Form 2220-1 (Rev. 4-77)   PREVIOUS EDITION is OBSOLETE

     Tne  information in  this document has been funded wholly  or
in part by the United  States Environmental Protection  Agency
under  assistance  agreement  number  CR 808529-01-2  to the
Environmental Research Center of the University  of Nevada, Las
Vegas,   it  has  been  subject  to  the Agency's  peer and
administrative review,  and  it has been approved Eor publication.
Mention of trade names or commercial products does not constitute endorsement or
recommendation for use.

      This report sets out a system for developing soil sampling
protocols  that can be used to meet the needs  of  the environmental
scientist working under a number of situations.  The body of the
report discusses the factors that influence  the selection of  a
particular sampling design and the use of  a particular sampling
method.   Statistical designs  are discussed along  with  the
appropriate analysis of the data.  Three appendices are included.
One is a discussion of the steps that must be taken to  arrive at
the desired protocol.   The  remaining appendices present two
examples of protocols; one for a shallow spill situation and  the
second for a deep contamination plume.   A technique called
kriging is presented as an approach for handling the analysis of
data  collected during  a soil sampling program.  This technique
allows the researcher to develop maps of the  pollution levels  and
to assign a statistical precision to the  data at each point on
the map.   The data presented on these two maps  can be  evaluated
to identify areas where additional samples  are needed to reach  a
desired level of precision for the area covered  by the maps.

      This report was  submitted  in  partial  fulfillment of the
requirements under Cooperative Agreement No.  CR808529-01-2 by
ETHURA under subcontract to the Environmental  Research Center of
the University of Nevada, Las Vegas and under the sponsorship of
the U. S.  Environmental Protection Agency.

Abstract	iii
Figures	viii
Tables   	viii

     1.   Introduction 	    1
     2.   The Soil System	    3
     3.   Initiating the Soil Sampling Study 	    6
          3.1  The Objective	    6
          3.2  Data Reliability	    7
          3.3  Resources	    8
     4.   Types of Soil Pollution Situations 	    9
          4.1  Large Areas Characterized by Shallow
                 Pollution Deposition  	    9
          4.2  Large Areas Characterized by Deep
                 Pollution Deposition  	   10
          4.3  Localized Areas of Surface Contamination.   11
          4.4  Localized Areas Characterized by a
                 Deeply Penetrating Plume  	   12
     5.   Review of Background Data	   14
          5.1  Historical Data	   15
          5.2  Geological Data	   16
          5.3  Soils Information 	   17
          5.4  Environmental Studies Data	   17
          5.5  Legal Cases	   18
          5.6  Remote Sensing	   18
     6.   Statistical Designs  	   20
          6.1  Background for Statistical Sampling Plans   20
          6.2  Simple Random Sampling  	   23
               6.2.1  Determination of the Number of
                        Samples Required 	   24
               6.2.2  Location of Sampling Points  ...   27
          6.3  Stratified Random Sample  	   28
          6.4  Systematic Sampling 	   29
          6.5  Judgement Sampling  	   31
          6.6  Phasing the Study	   31
          6.7  Control Areas	   32

     7.    Sample Collection  	    33
          7.1  Surface Sampling  	    33
               7.1.1  Sampling with a Soil Punch ....    34
               7.1.2  Ring Sampler	    34
               7.1.3  Scoop or Shovel Sampling	    35
          7.2  Shallow Subsurface Sampling 	    35
               7.2.1  Soil Probes and Hand Augers  ...    36
               7.2.2  Power Augers and Core Samplers .  .    37
               7.2.3  Trenching	    37
          7.3  Sampling for Underground Plumes 	    38
               7.3.1  Usual Procedure for Underground
                        Plume Sampling	    38
               7.3.2  Variations in the Procedures ...    41
          7.4  Compositing	    41
               7.4.1  Estimating Sample Variance ....    42
               7.4.2  Compositing with a Mixing Cloth  .    42
               7.4.3  Compositing with a Mixing Bowl .  .    43
               7.4.4  Laboratory Compositing 	    43
          7.5  Replicate Samples 	    44
          7.6  Miscellaneous Tools 	    44
          7.7  Record Keeping	    44
               7.7.1  Log Book	    45
               7.7.2  Site Discription forms	    45
               7.7.3  Sample Tags	    45
               7.7.4  Chain-of-Custody Forms 	    45
          7.8  Decontamination	    46
               7.8.1  Laboratory Cleanup of Sample
                        Containers	    46
               7.8.2  Field Decontamination  	    47
          7.9  Quality Assurance 	    48
          7.10 Safety	    48
     8.    Data Analysis	    49
          8.1  Analysis of Data for Simple Random Design   50
               8.1.1  Basic Parameters 	    50
               8.1.2  Use of t-Test	    51
               8.1.3  Analysis of Variance of Simple
                        Random Design  	    52
          8.2  Data Analysis for Stratified Random
                 Design	    53
               8.2.1  Basic Parameters for the
                        Stratified Random Design ....    53
          8.3  Data Analysis for Systematic Sampling
                 Designs	    55
               8.3.1  Kriging Analysis of Systematic
                        Data	    56

References	    62

     A    Soil Protocol Development Process  	   A-l
          Section A-l Purpose	A-l
          Section A-2 Preliminary Background Information  A-2
          Section A-3 Development of Protocol  	   A-3
               3.1 Background Information  	   A-4
                   3.1.1 Questions to answer	A-5
               3.2 Develop an Objective Statement for
                     the Study   	A-5
                   3.2.1 What is the study attempting
                           to accomplish	A-6
                   3.2.2 How close must the estimates
                           be to the real mean value .  .   A-6
                   3.2.3 How reliable must the answers
                           be	A-7
                   3.2.4 What resources are available
                           for the study	A-7
                   3.2.5 When must the study be finished  A-8
               3.3 Determing the Magnitude of the
                     Problem	    A-8
                   3.3.1 What is the known areal extent
                           of the contamination ....    A-8
                   3.3.2 What is the vertical extent
                           of the contamination ....    A-9
                   3.3.3 What chemicals have been
                           identified in the study area   A-9
                   3.3.4 What are the concentrations  .    A-9
                   3.3.5 Are the chemicals toxic  .  .  .    A-9
                   3.3.6 What is the attitude of the
                           community toward the problem   A-10
                   3.3.7 Place the study into one of
                           the four classes of studies
                           listed in 3.3B and go to 3.4   A-10
               3.4 Selection of a Statistical Design  .    A-10
                   3.4.1 How many samples do you need .    A-10
                   3.4.2 What is the distribution of
                           the sample sites-	    A-10
                   3.4.3 What is the frequency of
                           sampling	    A-ll
               3.5 Select a Sampling Method 	    A-ll
               3.6 Data Analysis	    A-12
     B    Sampling Protocols for Surface Soils  ....    B-l
          Section B-l Overview	    B-l

     Section B-2 Sampling Design 	    B-2
          2.1 Minimum number of samples  	    B-2
              2.1.1 The equation	    B-3
          2. 2 Grid Layout	    B-3
              2.2.1 Selection of a starting point    B-5
              2.2.2 Grid size	    B-5
              2.2.3 Physical location of the grid
                      in the field   	    B-6
          2.3 Compositing of the Samples	    B-6
          2.4 Replicates	    B-7
          2.5 Controls and Background Samples  .  .    B-7
              2.5.1 Location of Controls	    B-7
     Section B-3 Sample Collection on the
        Triangular Grid	    B-9
          3.1 Sampling for Non-volatile Chemicals    B-9
          3.2 Sampling for Volatile Chemicals  .  .    B-9
              3.2.1 Soil Sampler	    B-10
              3.2.2 Collection of sample	    B-10
              3.2.3 Transport and analysis ....    B-10
     Section B-4 Records, Security and Safety  .  .    B-ll
          4.1 Records	    B-ll
          4.2 Security	    B-ll
          4.3 Safety	    B-ll
          4.4 Site Restoration	    B-12
     Section B-5 Data Analysis	    B-13
     Section B-6 Staffing, Equipment and Supplies    B-14
          6.1 Equipment and Supplies	    B-14
C    Sampling Protocol for Contaminant Plume .  .  .    C-l
     Section C-l Overview	    C-l
     Section C-2 Sampling Design   	    C-2
          2.1 Minimum Number of Samples  	    C-2
          2.2 Grid Layout	    C-3
          2.3 Control Area	    C-4
          2.4 Preliminary Study  	    C-4
     Section C-3 Sample Collection 	    C-5
          3.1 Sampling Equipment 	    C-5
          3.2 Non-Volatile Pollutant Sampling  .  .    C-5
              3.2.1 Sample extraction  	    C-5
              3.2.2 Sample preparation 	    C-6
          3.3 Volatile Chemical Sampling 	    C-7
          3.4 Security	    C-7
          3.5 Safety	    C-7
          3.6 Decontamination	    C-8
     Section C-4 Data Analysis	    C-9
     Section C-5 Staffing, Equipment and Supplies    C-10
          5.1 Staffing	    C-10
          5.2 Equipment and Supplies	    C-10


Number                                                    Page

7.1        Trench sampling techniques 	   39

8.3.1      Flow sheet for kriging   	59

8.3.2      Examples of semi-variogram developed during
             kriging	60

B-2.1      Triangular grid design	B-4

Number                                                    Page

8.1.1      Analysis of Variance for Simple Random Design   52

8.2.1      Analysis of Variance for Stratified Random
             Design	54

B-2.1      Number of Sampling Points in a Triangular Grid B-5

                          SECTION 1

    Environmental assessments  are  designed to evaluate  the
impacts of chemical pollutants  upon  man and his environment.
Considerable effort has been expended in developing protocols  for
use in monitoring  for air and  water  borne pollutants.  The
complexities encountered in sampling the soil  system have been  a
major  handicap  in the development of field procedures.  The
Office of Pesticide Programs has promulgated a document outlining
procedures  for sampling for  the  National Soil Pesticide Survey
Program (Office of Pesticide Programs,  1976).  This document  has
proven to  be useful in the  sampling  of soils on a nationwide
basis but  cannot be used effectively in many situations where
hazardous wastes are encountered.

    The system presented below is  designed to  provide  the
environmental scientist with  a  means for developing a protocol
that will satisfy the  soil sampling needs of agencies such as  the
U. S.  Environmental  Protection Agency (EPA).  The methods
presented  will provide the  scientist with adequate tools  for
producing reliable estimates  of the  spatial distribution of soil
borne pollutants.  The  techniques described in this report have
been  borrowed from a number  of areas of soil science.  Each
section provides  information  that will enable a person that is
knowledgeable in the behavior  of  pollutants with the necessary
tools  for  acquiring soils data that will meet most of the needs
encountered in environmental monitoring work.

    In order to use this document,  the environmental scientist
should have a familiarity with  the general properties of  soils
and  have  some  idea  of the  behavior  of  pollutants in  the
environment.  A chemist and a  statistician must be available  for
consultation from the outset of any soil sampling study  in  order
to provide the technical input into the selection processes that
are needed  in developing the  protocol.  The field scientist must
be given latitude  in  modifying  the protocol to meet  unusual
conditions not covered during planning; but, these judgement
calls must  be  made  in  concert  with  the chemist  and the

     Scientists  working  for  the EPA will  need  to follow
procedures  in the areas of chain-of-custody and quality assurance

that are more riqid  than those  likely  to  be required by a
non-regulatory  agency.   Sections dealing with  these  areas are
included in  this  report;  but they have been  made  brief because
documents  are available  from  the EPA National Enforcement
Investigations  Center  (NEIC) that cover   these  areas  in
considerable  detail.  Chemical  analytical  methods  are not
discussed in  this  report even though these methods are factors
that must  be  considered in  selecting the appropriate sample
collection  techniques.

    The basic  format  of this report is designed  to  allow the
environmental  scientist to  arrive at the selection  of  a sampling
protocol by answering a series of questions found in Appendix A.
The answers  to the  questions will then lead  to one  of several
approaches  that can be used in  a particular study  setting.  The
sections of  Appendix  A  are  arranged in a chronological  order
leading from  initiation of  the study through to  the statistical
analysis of the data and  point back  to one of the sections  in the
main body  of  the  report.  Sections 2, 3, and 4 outline some of
the basic concepts needed  to  plan  and initiate  a  soil sampling
study.  Section 5 sets out  the types of background data that are
needed in order  to  properly evaluate the  situation  in a
particular soil  sampling study   area.   Section 6  presents
statistical designs, Section 7 the methods for  collecting samples
and Section 8  data analyses.

       The  sections on sample  design and data analyses  present an
approach that  allows the  scientist to handle and present the data
that has been  acquired through  a sampling program designed to
estimate the  levels and distribution of pollutants found  in the
soil environment.   This approach,  called kriginq,  has been used
in evaluating  the distribution of radioactivity at a  number of
sites both in  the United  States and on the Enewetak Atoll.  The
method  was  developed in France for  use in ore  evaluation and has
recently been  used in the United States by a number  of  scientific
disciplines.  The use of  the technique is still in its  infancy in
the environmental fields  but appears to hold considerable promise
as a tool for  evaluating  pollution patterns. The major advantage
of  kriging  is  in  the  abil.ity   to develop  estimates  of
concentrations over a geographic area and also  provide  a  measure
of the confidence limits  to  be placed on the  data  at  any point.
The statistical  errors  at each point can be  plotted on  a map
which shows the isopleths for  the error terms.   The  resulting map
allows  one  to  identify where  additional  sampling sites would be
most beneficial in increasing  the reliability of the data set.

                          SECTION  2

                       THE SOIL  SYSTEM
    Soil sampling as presented  in  this report encompasses the
entire mass of unconsolidated mantle of weathered  rock and loose
earth material lying above solid  rock.  This definition  is that
used  by the engineer rather than the agriculturalist (Soil
Science Society of America,  1965).

    The physical and chemical characteristics  of  the soil system
influence the  transformation, retention  and movement  of
pollutants through the soil.   Clay content, organic  matter
content, texture, permeability, pH,  and cation exchange capacity
will influence the rate and  route of migration.   These  factors
must be considered  in  the  process of designing a  sampling plan.
The agricultural  worker  considers these factors but does  not
focus the  sampling design  on them because a farmer is interested
in how much lime or fertilizer to  apply to a field  and not in the
avenues of movement of that  fertilizer through  the soil  system.
Little  consideration  is  given to the spatial variability of a
field.   Occasionally  a  farmer may fertilize  two  different soil
types at different rates if  the yield gains and fertilizer  cost
savings can justify the time and effort required.   In such a case
the soil scientist sampling  the farmer's fields may take separate
samples of each soil  type.  The environmental scientist on the
other  hand is  interested   in a  number of possible  types of
pollution  and routes of migration.  This cannot be  addressed with
a single sample or a single  composite sample.  Therefore,  some
form of statistical sampling design must be used  to evaluate the
pollution  in  a soil system.   This  report  will present  several
options for sampling  soils that are available  for  evaluating
pollution  migration.

    Environmental sampling must take into consideration  one of
the key  characteristics  of   the  soil  system  -- extreme
variability.  Cline (1944)  noted  that  even though it was common
knowledge that  analytical  errors are much less  than  sampling
errors, little attention  has been given to studies that would
provide data for  developing a sound sampling procedure.  Cline
further noted that, "the  limit of accuracy is determined by the
sample not by the analysis".  The limited knowledge  about soil
variability changed very little until about two decades ago.

    Nielsen  and his associates (Nielsen et al., 1973;   Warrick et
al.f 1977;   and  Vieira et al., 1981) have  begun to study the
spatial variability of the soil  system in an attempt to  develop
reliable predictions of water movement through the soil. Campbell
(1979)  makes note  of  the  fact  that,  in  1915,  J. A.  Harris
discussed the  effects  of soil variability  on  the results of
experiments.   Campbell has used this knowledge in  evaluating
approaches  to  delineating soil mapping units  (Campbell 1977,
1978,  1979,  1981).   Rao et al.  (1979) reviews other work where
spatial variability was considered.

    Petersen and  Calvin (1965)"also note:  "Soil properties  vary
not only from one location to another but also among the horizons
of a given profile.  The horizon boundaries may be more distinct
than are the surface boundaries of a soil classification unit.
Here,  also,  however,  zones of transition  are found  between
adjacent horizons".   The magnitude of sampling  errors  between
layers of soil  tends to be less than the magnitude  of sampling
errors in a  horizontal direction.   Disturbed or plowed soils are
reported to be  more variable than virgin  soils in  most cases
(Chapman and Pratt, 1961).

    One measure  of variation is  the coefficient  of  variation
  (CV)*.  Coefficients of variation for soil parameters have  been
reported ranging from  as low  as 1  to 2%  to as high as 850%.
White and Hakonsbn  (1979), for example, noted  that  the  CV for
plutonium in the soils  of a number of test sites ranged from 62%
to 840%.  Mathur  and Sanderson  (1978)  reported coefficients for
natural soil constituents (i.e., part of the soil itself)  varying
from 5.6% to 75.2%.  Harrison (1979) evaluated four phosphorus
properties  of soil and  reported  CV  values ranging  from ll% to
144% with the highest values being for available P.   Hindin et
al.  (1966)   reported  a  CV of 156%  for insecticide residue
concentrations  in a square block of soil that was 30  inches  on a

    Mausbach et al.  (1980) reported on a study conducted  by the
Soil Conservation Service (SCS) laboratory in Lincoln, Nebraska.
Matched pairs of  samples were collected from areas within a  soil
series. The samples were stratified by a number of  factors in
order  to reduce  the variability.  The samples were selected  from
the modal phase  of the series  and were  collected at distances
that ranged  from  2 to 32 km from the other member  of the pair.
The authors  note  that the literature indicates that up to  half of
the variability between  similar  soils may occur within a distance
       CV =  +s/y X 100
               where CV = coefficient of variation in  %
                     _s = standard deviation of sample
                     y = mean  of  sample

of one meter.   (Studies are underway at Lincoln  to determine
variability within  this one meter distance.)  Mausbach et al.
(1980)  reported that in  their  study  of  the  variability within a
soil type  the CV s for physical properties ranged  from 9  to 40%
for loess, 23  to  35%  for glacial drift, 33 to 47% for alluvium
and residuum, 18 to 32%  for  the A  and B  horizons,  and 33 to 51%
for the C  horizons. The CV's for the chemical  properties  tended
to be higher ranging  from 12 to 50% for Alfisols,  4 to 71% for
Aridisols,  6 to 61% for Entisols, 10 to 63% for Inceptisols, 9 to
46% for Mollisols,  16 to 132%  for  Spodosols, 10  to 100% for
Ultisols,  and 8 to 46% for Vertisols.

    The variation that seems to be  inherent in the  data collected
from any soil sampling study must be taken  into  consideration
during the design of a sampling plan for whatever  the purpose of
the study.  Technologies designed to take  the variation into
account must be  employed in  anv soil sampling  plan.   This
includes  the sampling design, the collection procedures, the
analytical  procedures and the data  analyses.

                          SECTION 3

    The identification of the components  needed  in a specific
soil sampling protocol begins with  a  clear statement of the
objectives of  the study and  follows through a series of steps
that are required  to  select  the  sampling  design, the tools  to
use, the size of crew, etc.   Each step is characterized by a
number  of decisions that must  be made  before  the protocol can  be
finalized. A number of the questions  that  must be answered  in
making the decisions  are given in Appendix A in order to assist
the reader in making the  appropriate selections.  The key
components of  any soils study are discussed  in the sections that
follow this  brief introduction to  the protocol development

    A  further  assumption has  been made  that the scientist, his
supervisors and the administrators calling for the study are
committed to producing a quality  study. This requires that a
clear  statement of the objectives be made and that adequate time
is given for planning  and reviewing the  study.  This report can
help shorten the planning time  by  focusing  the reader into the
areas  where  decisions must  be made;   but,  the commitment  to
succeed must come from  those responsible  for  the study.
3.1 The Objective

    The  objective statement sets  forth  the  specific goals  that
are to be met by the sampling program. This  statment should  be a
clear, concise definition  of why  the study  is needed and what
questions the studv  is  to answer.   It  could  be as brief as a
question  such as  "How much  of  the surface area around the
accident at the XYZ railroad siding  has been  contaminated with
trichloroethylene  (TCE)?";  or,  it  could be the request for a
detailed study in  support of  an  enforcement  action that must
determine the likely  avenues  of  contamination leading from a
hazardous waste site  into  a community.  The  important point  that
is being made is that  the goals of the study must be spelled out
and must be agreed upon by  all  parties involved with the study.

     As part  of the objective  statement,  the environmental
scientist  responsible for the study should attempt  to obtain a
statement of  the  data  reliability  desired  and  the resources
committed.   If  this cannot be clearly given at the  outset,  some
initial  goal  should be  indicated with the final  goal selected
after a number  of iterations during the planning  process.

3.2 Data Reliability

     The  scientist needs to know two things before  selecting the
components  of  the study plan —  the confidence level  desired and
the allowable margin of error to be met by the results.

     Too  often, soil  sampling is done without  a clear knowledge
of  the level  of  precision that can  be met  by  the  study.
Laboratory systems have  been  developed  to  the point where
considerable confidence can be placed in the results  produced by
a quality  laboratory.  Quality  assurance is maintained throughout
the studies.  The sources of uncontrolled variation are too  great
for  a  field study to meet the  precision found in  a laboratory.
The only alternative is to select  a level of confidence that is
acceptable and attainable within  the limits of  the resources
available  for  the study.

     The  reliability expressed  by the confidence level states the
level of precision of the results  generated by the study.    Three
confidence levels are normally used by the scientific community.
These are  usually expressed as + 1 standard deviation,   +  1.96
standard  deviations and + 2.58  standard deviations which covers
68%, 95% and 99% of the total population, respectively.   Another
way  to state  this is to say the probability is 0.32  (or  1  in 3)
that the value  is outside of one standard deviation  on  either
side  of  the mean; 0.05(or 1 in  20) that the value  is outside of
1.96 standard deviations;  or 0.01  (or 1 in 100)  that  the value is
outside  of 2.58  standard deviations.  Where results must be
absolute,  a 99%  confidence level should be used.   Where resources
are  limiting  or  reliability is  not of paramount importance, the
68% confidence  level may be acceptable.  Environmental sampling
often  attempts to attain a level of 95% confidence.  The actual
level is not as  important as the fact that the level  is known and
agreed upon before the study is  started.

     Environmental studies can often be conducted  in phases with
an increase in  reliability attained as each phase is completed.
The design  of  the study should allow for this by  designating  the

confidence level  for  each phase and planning the  study so that
each phase  produces  an answer.  For example, the  first phase  of
many  soil  sampling programs is a pilot or exploratory study.   If
properly  designed,  this can  produce results with a  known
precision  and thus  avoid the problems of the "quick and dirty"
look at  a soil study area.  The confidence level  for this phase
might  be  the  68% level.   The  second phase  might be more
definitive  whose study design makes use of the data generated  by
the  pilot  study.   The results  are expected  to  reflect this
increased knowledge; therefore, the study should  be  designed  to
acquire the  data  to  meet this precision.  The  confidence level
might be  increased  to 95%  for  this phase.   There may  be
particular situations where  it is necessary to reach a 99%
confidence  level.  An example where this might be  required would
be a  litigation case  where there was a possibility that a home
had been contaminated by chemicals from an abandoned  hazardous
waste  landfill.  The emotions  and the liabiity  force  the
scientist to attempt to  meet a higher level of reliability.

     The second  item  listed,  the margin of error, is needed in
determining the number of samples required to meet the  precision
specified  above.   This is often expressed as a  percentage error
that  the  scientist  is willing  to accept  or  it  may be  the
difference that he  hopes to  detect from the study.  The value
designated  should reflect the importance  and  use  to be made  of
the  numbers.   Clean-up of a chemical spill might require a less
precise estimate  of  pollutant  levels than would  a  study
attempting to identify subtle variations in background levels.
In the spill case, the scientist wants  to know  if  a  soil sample
is contaminated or  not.  This situation could change, however, if
the spill was of a known carcinogen located  next  to a city's
water treatment plant.   The margin  of error chosen is combined
with the confidence  level to derive an  estimate of the  number  of
samples required.   The smaller the  margin of error; the larger
the number  of samples required.

3.3 Resources
     The data reliability is often modified by the  time and money
available for the study.  An attempt should be made to estimate
as precisely as possible the  amount of resources  that can be
committed to a particular  study.   This commitment  should  be
spelled out and monitored on  a regular basis.   The resources
needed include not only money but personnel, laboratory capacity,
equipment  and  time.   Where  time and staff  are both in short
supply the reliability of  the study will have  to be lower  in
order  to  meet  the  schedule.   Planning for the study must also
include resources  for  the  handling  of paper  work and
chain-of-custody along with shipping costs of samples where these
are not handled directly by the sampling  crew.


                           SECTION 4

    There are  essentially four major types of sampling  situations
that the  environmental scientist is likely to encounter.  These

     o   Large area  studies where pollution is in  the
         surface  layers, e.g., in support of an ambient
         monitoring  effort.

     o   Large area  studies where pollution has moved
         down into  the  soil  profile, e.g.,  assessing
         the  impact  from a major industrial complex.

     o   Localized area studies  where the pollution  is
         in the surface layers, e.g., sampling around a
         recent hazardous chemical spill.

     o   Localized plume studies where the major source
         of contamination is below the surface  at some
         depth, e.g.,  sampling near a leaking hazardous
         waste disposal site.

    The environmental  scientist should attempt to determine which
of  these  categories exist   in  the  area to be sampled.   Factors
such as length of time that the site has been contaminated,  the
type of pollutant, the type of soil and the past use  of the area
must all  be 'considered in determining which  study category  to
use.  The sampling  methods and  the  statistical  designs  used  in
each case are  slightly different.  These are briefly covered  in
the paragraphs presented below.
4.1 Large  Areas  Characterized  by  Shallow Pollutant

    The basic characteristic for this category of study  is  that
the pollutant covers  a wide  area and is expected to be  primarily

on the surface.    Studies  in this class are  usually applicable to
surveys  of ambient monitoring or monitoring downwind of a major
pollutant  source  that  has been present  for a  short time span.
The pollutants may have migrated into the soil  up to one  to  two
feet  but they tend to be located  only in  the  surface layers of
the soil.   Where organic matter  is  present  in these layers,
penetration may only be a few  inches.  Hand tools  are usually
used  to  collect samples.  The  designs are usually either  the
stratified random  or  the systematic grid designs.  In cases where
there  has  been penetration and where a large number of samples
are to be  collected, the scientist may desire to  use a  power
driven sampler.   In  this  latter case,  the  samples may  be
sectioned into several layers located at depth below  the surface.
This will enable the  scientist  to  evaluate  the  movement of  the
pollutant through  the soil mass if this is desirable.

    The fact that  the pollution covers a large area, encompassing
a number of soil types and topographic features, makes the  use of
stratified sampling desirable.  The strata can be identified by
soil type,  by position on a slope, by parent material and in some
cases by aspect  and  vegetation type.  Compositing is often used
to further reduce  the variability  and to reduce the cost.   The
large area covered by the study creates a large number of samples
thus cost reduction  techniques  are important.  The National Soils
Pesticide  Monitoring Program of the Office of Pesticide Programs
in EPA is an example of  a study conducted at  this  scale (OPP,
4.2 Large  Areas Characterized by Deep Pollutant Deposition

    These  study situations are similar  in  character to those
presented in  section 4.1 with the  exception of the depth of
pollutant migration.  The sources are  such that one would expect
the chemical  pollutants to move down  into the soil profile to a
considerable depth.  Sources might be major  industrial complexes
that existed  prior to implementation  of  the  Clean Air Act,  major
agricultural  areas where pesticide useage has been in effect  for
a number of years, world wide nuclear  fallout, lead contamination
from automobile exhaust or benzo-a-pyrene in an urban area.   The
pollutants  would be those that are not considered to be reactive
with the surface soil constituents and  would  likely be soluble in
water to some extent.  Metals that are  known  to chelate with soil
organic matter  may fall into this class  in some cases.

    Sampling  must be done with power equipment but the depths of
sampling are usually not as deep as  those presented in  Section
4.4.  Composite samples  are not recommended if they can be
avoided  because of  the information  that is  lost  during  the
mixing.   The  migration  of the chemical through the soil is
usually one of the  factors of  primary concern  in these
s ituations.


     The  statistical  designs are somewhat similar  to  those used
in the cases discussed in Section  4.1.   Stratification  is
desirable in most cases.  Systematic grid sampling  can prove  to
be effective if  local variation  is not of interest.  Kriging  of
the results usually does  not work too  well because the range
identified  by the variogram is usually around  one to two
kilometers thus the intensity of sampling  required  to use this
technique  requires  too many  samples to be cost effective.   If
local variation is of  interest,  the environmental  scientist may
desire to  identify  specific  local  areas where  information  is
needed and conduct a  study on a  smaller scale in  those areas.
This  allows  the  intensity of  sampling to be increased and still
not run up the costs  of the study.

     An  example  of  a study that is similar to the  last situation
would be  the soil monitoring done in support of the  clean-up  of
Plutonium  contaminated soils found on Enewetak Atoll (Barnes
4.3 Localized Areas of Surface Contamination
     This category of sampling is  probably one of  the most likely
to occur  in the future.  Spills that result from  industrial or
transportation accidents, fires, or unexpected leaks from storage
containers usually pollute  the soils  in  local areas  near the
source.   The primary purpose of  the sampling efforts are to map
the extent of pollution and to determine the effectiveness of the
clean-up operations.   In some  cases the polluted areas can be
identified by color or other observable indicators.  If the
Emergency Response Team is able to be on-site within a short time
after the accident or spill, sampling may be very  rapid and can
be  done by  either grid,  simple random sample or, in some
specialized cases, stratified sampling.  Judgement sampling may
be permitted in some cases but this method should not be used if
follow-up monitoring  is  to be  done.   A simple random or
stratified  sampling plan can be done with  a  few samples and
provide a basis for measuring the degree  of clean-up  that has
been  accomplished; thus, nothing can really be gained by using
judgement sampling.

     The  samples are  usually collected with a King tube sampler
and  can  be  composited  in some  cases.   The  fact  that the
pollutants  found  at spill sites  are limited to a few identified
chemicals greatly reduces  the costs  of  analysis. Therefore,
individual  samples can  be collected  and analyzed without
prohibitive costs. The scientist may  desire to collect and
composite  a  number of  individual  samples  at  each sampling
location, thus reducing the variation in the results of the study.
The use of individual samples allows the investigation


teams to make  more  definitive conclusions  about  the pollution
deposition  but  this is often not  justified in these  limited study
4.4 Localized Areas  Characterized by  a  Deeply Penetrating
    The EPA  is currently involved in a number of  studies where
groundwater  plumes  have migrated from landfill  sites or from
leaking  storage  tanks.  These plumes tend to  follow  the
groundwater  flow  and tend to  occur at considerable depth below
the surface.  Sampling is often limited to the  collection of
groundwater  samples rather than soil samples  because  of  the
relative  ease in sample collection and analysis compared to the
sampling and  analysis of soils.  The results obtained  from water
samples tend  to be more uniform than data from soil samples.

    The location  of  the pollutant plume will probably require
some form of phased approach that will be done  in conjunction
with the geologists.  Sampling requires heavy drilling equipment
and frequently is limited in scope due to the costs involved with
obtaining the samples.  Split  spoons are usually  used to obtain a
core of the  soil from depth and provide a means of obtaining a
relatively undisturbed  sample of  the soil  for use in both
physical  and chemical analyses.   The cores obtained by this
method are easily viewed at the time the sample  is removed from
the split spoon.  Records or  logs of the strata observed can be
used for selecting samples for  analysis and for  interpretation of
the results  obtained.

    The statistics for  this type of sampling is  complicated by
the fact that depth plays a prominent role in the analysis of the
results of the sampling.  Regression may be required along with
stratification with depth if  any meaningful interpretation is to
be made from  the results.   Frequently  in  deep  sample  collection
situations a  layer with high permeability will  be encountered.
Some flexibility must be included in the design  to allow these
samples to be collected if they are encountered.  A phased study
approach will allow  these  areas  to  be  identified  and
incorporated  into the final sampling phases.

    Mapping  of the  contaminant plume becomes quite important in
many enforcement  cases.  This fact should encourage  the use of
some form of systematic sampling array.  Kriging can be used
effectively  in this kind of situation.  The mathematics required
for three dimensional kriging analysis may preclude  the use of
this technique for other than  selected layers through the plume.

    Sample  replication, quality  assurance, and decontamination
all become  more difficult  in  these cases because the  study  is
actually being conducted  below  ground beyond the sight of the
researcher.  Cost may force the  researcher  to compromise on the
precision of the  numbers  obtained.  The fact  that a  number  of
samples may be collected  from each hole drilled also compounds
the cost and complexity  of  the  operation.   Careful  planning,
however, can overcome many  of  these problems.

    It should be apparent  that these four  categories of studies
do not cover all possible  situations.  There are many  instances
where a hybrid between two  or more of them  may occur.   It  is
believed that the  use of  these  four categories will allow the
environmental scientist  to adapt  to  meet the  situations
encountered in the field.   The field researcher should  be  aware
that modifications  may have  to  be made in the plan to meet the
unusual  situations that often  occur in field sampling.  He should,
however, not make changes  without carefully planning the changes
and consulting with the  chemist and the statistician before
altering the designs and techniques used.

                           SECTION 5

                  REVIEW OF  BACKGROUND DATA
    Any monitoring effort  requires  a  familiarity with the study
area.  Too  little  time is usually spent  in  preliminary data
collection,  evaluation and planning.   It  is  difficult,  if not
impossible,  to  undertake a reliable  soils study without review  of
existing data.   The  sources  presented  below should be evaluated
and studied  prior  to developing a  plan.   The areas below are
presented  in  order to draw the scientist's focus onto those types
of data that  will reveal the potential  location of pollutants and
help evaluate their migration through  the environment.  Combined
with site  visits  and  interviews with  local citizens a good grasp
of the situation  can be gained.

    Libraries,  museums,  governmental  agencies, public agencies,
data bases and  researchers are all  sources of information that
can be accumulated prior to finalizing  the study plan.  Often the
local citizens  can provide information  that  is  not available  in
any of the normal research channels.  The environmental scientist
working on  abandoned hazardous waste  sites will find that often
the  public  citizen  is  one of  the  most useful  sources of
unpublished  data.   They have often lived  in  the area and are
familiar with  the  operation of the site and  may even provide
insight into  the  types of chemicals  and  the  methods of disposal
at the site.  The scientist working  in  these cases must become  a
detective.  Any piece of information  that will help determine how
and where  the pollutants may migrate  is useful in planning the
study.  Each  piece of information must  be sifted and evaluated  in
an attempt  to  determine how the soil  system  responds to such
factors as flooding, movement  and use.
    The following  listing  of information is only  partial and
reflects  the  author's own experience.  Each researcher should  be
able to use this  listing  as a starting point from which  to
develop the needed data for  other studies.

5.1 Historical Data

     The scientist should  attempt to collect all  available
documents  dealing with  the study  area  including  newspaper
accounts,  if time permits.  The more informed the investigator
is, the  better his grasp of the situation.  The result  should be
a  knowledgeable study  that addresses  the pollutant problem in the
context  of  the soil system in the study  area.   Historical data
can  help  answer questions about the  sources of pollution, routes
of migration, uses of the  area, or any data  that  will aid in
designing  a study that will acquire the necessary data. The kinds
of information will vary with the site;  but,  in general, they
deal with  the history  of use  of the area, historical drainage
patterns, groundwater flow and use, and environmental  and health
problems associated with the study area.

     Wildlife biologists and other conservation workers familiar
with the natural environment  in the study  area  along with
hunters,  conservation  groups  and  scout groups can prove to be
valuable sources of information about  the wildlife and vegetation
changes  that can reflect the impacts of pollution in the area.

     Stream gauging station operators, boating  clubs  and
sportsmen are valuable  sources of information about the possible
routes  of  migration  for groundwater and pollution.  Often they
have noted  changes in color,  sediment  loading, algal blooms,
etc., that indicate  chemicals are entering the streams in the
area. This becomes especially important when abandoned hazardous
waste sites are the source of pollution.

     Local authorities,  such  as  fire,  police, health,
engineering, highway and maintenance  departments,  tax
departments, forestry  and conservation workers can all provide
valuable information  on  prior  land use.   Where  spills have
occurred  the local fire department  are often able to provide
information on the movement of the spilled  materials.   This is
especialy  important  if  they  have  used  any  particular
countermeasures on unusually toxic chemicals.

     The U.  S.  Soil  Conservation  Service  (SCS)  along with
the  Cooperative  Extension Service and  the  Agricultural
Stabilization and Conservation Service  (ASCS) have frequent
contact  with the local  community and are often in the rural areas.
They are  interested in the soil system and are usually qualified
to assist in obtaining  the kinds of information  that  are needed
about not  only the history of the area but also the presence and
effects  of  pollution. The staff of all three of these  groups  can
usually identify the  local historians in the community.  SCS and
ASCS both maintain files  of  aerial  photographs of  the area.
These files often go back for a  number of years and can give
information on the uses of the area along  with  changes in soil
character with time.


    Basically the  environmental scientist  is  attempting to
reconstruct the situation with time.  An attempt must be made to
determine where the pollution came  from,   how  long it has been
present,   where  it  has gone in the past,   and'what effects it
had.  Any information  that will  aid in  answering  these types of
questions will assist  in developing  a meaningful study plan.
5.2 Geological  Data

    The geological character of the area  is  important not only
for determining the routes of migration of soil pollutants but
also as  a  factor in  any attempt to stratify  the  area into
homogenous  soil  types.  Parent materials  and  bedrock  can often
play an  important part in determining how  the  pollutants will
react in the  soil.

    The U.S.  Geological Survey (USGS), the Corps of Engineers and
the Bureau of Reclamation all maintain  information  on stream
conditions  and stream flow.  These agencies are valuable  sources
of data about the history of the  stream channels,  about dredging
of channels in the streams and about flooding.  These factors may
play  an important  part in determining  the  rate and route of
pollution migration.   Groups  such as  the Tennessee Valley
Authority, the  Colorado River Commission and the Great Lakes
Basin Commission have environmental scientists on their  staffs
that are often  able to provide insight  into  the environmental
setting of  the streams and lakes  in the area.

    The USGS  has produced many reports on the geology of parts of
the U.  S.  Their staffs are knowledgeable  on rock formations,
drainage, groundwater flow and quality, and can provide maps and
remote sensing  data in many cases.   The USGS field  geologists
often work  closely with  the  various  state agencies  that cover
areas such  as mining, groundwater,  construction and environmental
geology.  These  scientists are usually familiar with the settings
where studies are to be conducted;  in fact, they  have  often been
the first persons contacted when  a  problem with groundwater has

    Any information that will tell  the scientist about  the nature
of the bedrock, the groundwater elevations,  the direction of
groundwater flow and the sources of recharge  to the  aquifer
should be acquired prior to developing the final study  plan.

5.3 Soils  Information
    As was mentioned above,  the SCS, the ASCS and the Cooperative
Extension  Service (County Agent) are three of the best sources of
information on soils in an  area and should be the first point of
contact before any other soils data searches are undertaken.   The
state  offices and the local  offices of  the SCS  maintain
information on the status of  the agricultural system in the areas
under  their responsibility.   The SCS soils reports are a  good
place to develop a familiarity with the soil  types in  the study

    Most  states maintain an agricultural school that is closely
aligned with  the U.  S.  Department of  Agriculture's various
offices.   The  Soils Departments of the Land Grant Universities
are in close contact with SCS and are often closely involved in
agricultural soils analysis  work.   Their files often contain
valuable information on the nature of the  soils in an  area and
they often know of problems  that have surfaced in the past.   Some
of the universities have maintained samples  of  soils  from past
studies.  These can, on occasion, provide a valuable insight  into
past pollution  levels  if  the samples have been  property

    Any data that will assist in determining the soil properties,
chemical  composition,  amount of organic matter,  rates of
percolation into  the  soil,  crop history, type and amounts of
clay, drainage patterns within the soil and spatial variability
in  the study area can  be  a  valuable  asset when time comes to
interpret  the results of the  study as well as during the planning
phases of  the study.
5.4 Environmental Studies

    Other  scientists often are interested in  the same areas where
the environmental scientist is attempting to determine the levels
of  soil pollution.  These studies often provide valuable insight
into  the problem, the system  and are possible  sources  of
information. Frequently the geologist working on a groundwater
problem will have information on  pollutant migration  and soil
properties that can prove to be valuable. The well driller's  log
books kept  when exploratory borings are  made for construction of
highways can be  used  to augment the  data collected by the soil

    Universities  in the area frequently have accumulated data as
part of thesis projects and other research studies  that can be
used to increase the understanding of the soil system.


     Where  the  EPA or one of its  state counterparts has been
investigating  a  particular  pollution  incident,  the  data
accumulated by  them along with any analyses  should be consulted
prior to undertaking the study.   This search for  data at the
state  level should include both the environmental agencies and
the health agencies.  Where  the data is archived will depend  upon
the  state involved.  Each has a slightly  different organizational

     Environmental  impact  statements  are a gold mine of
information that  can save considerable  time for  the field
scientist.   Studies where highways and canals, etc., have been
the subject  of the  EIS can  greatly increase the  information
available  for  planning with little cost involved on the part of
the researcher.

     The investigator is  attempting to find information on the
pollutants,  routes of migration, and effects  of that migration.
Therefore,  any  environmental study that has been undertaken in
the past can provide the keys to preparing a  viable study plan.

5.5 Legal Cases

     Where  legal action is  pending at a particular location, data
often is available through   the  various enforcement  channels.
This  type  of information is sensitive and often difficult to use
due  to  chain-of-custody  and  confidentiality.   Frequently
government agencies will share data with each other under normal
conditions but when court action is involved  or possible, data is
difficult  to obtain and  even more difficult to use in an open

     Where  a case is  closed, considerable  data may be available
in the various enforcement offices and in  the court proceedings.
This  is available and can usually be obtained  if the need exists.
The time involved can be extensive but the data may well be worth
the  effort  if the soils study being planned  has the potential for
creating controversy or of being used in litigation.

5.6 Remote Sensing

     Imagery obtained from  either aircraft or  satellite can prove
to be valuable in determining the impacts  of  pollutants and in
identifying routes and effects of migration.  Old landfill sites
can often be identified from archived aerial  photography which
are perhaps  one of the best  historical records  available.  The


USEPA's Environmental Monitoring Systems Laboratory  in Las Vegas,
Nevada (EMSL-LV)  is the best  resource available for  pollution-
oriented  imagery.  They are  knowledgeable about  sources of
existing imagery  and also can assist in obtaining new  imagery.
Photographs  taken in conjunction with accidents  or chemical
spills  are a  valuable resource for  determining  the  areas where
samples should  be  taken.

    The following  sources  can  often provide information on
available imagery.

           Agricultural Stabilization and Conservation Service
           Bureau  of Reclamation
           Colorado River Commission
           EROS Data Center in Sioux Falls,  SD
           National Aeronautics and Space Administration
           National Archives and Record Service
           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. Soil Conservation Service

                          SECTION 6

                     STATISTICAL DESIGNS

6.1 Background for Statistical Sampling Plans

     This section outlines the basic statistical designs that are
available  for use in soil  sampling.  The procedure for  selecting
the appropriate design is  covered in Appendix  A.

     The purpose of any soil sampling program is  to  obtain
information about, or a constituent of the soil.  The information
obtained from  the study  should be  representative of the soil
system in  the study area if it is to be useful to the  scientific
community.   Much  of the  data collected for soil systems in the
past have  been based upon  samples collected according to sampling
plans  designed  for agricultural systems.   These were patterned
after  reports such  as Cline  (1944),  the  Soil Conservation
Service's Soil Survey Manual (1951) or monographs similar to the
USDA's Handbook #60 - Diagnosis  and Improvement of  Saline and
Alkali Soils  (Richards,  1969).  These resources provide guidance
on soil sampling but the approaches often provided are not
adequate for  studies dealing with soil pollution.

     Soil pollution studies require that sampling results provide
input into decisions that  often have profound  health and economic
consequences.   The environmental scientist  desires to determine
an average concentration,  a measure of  data reliability, the
direction of movement  and the location of  any "hot spots" that
are likely  to create  an  undue  hazard  to  the public or the
environment.  The sampling designs used must  provide this type  of
information with maximum reliability and minimum cost.   Limited
laboratory capacity for conducting sophisticated analyses such  as
those for pesticides, priority pollutants and  TCDD, the potential
for litigation,  and  public  awareness  further  force the
environmental scientist into a detailed planning mode.   When the
time  and expense  invested  in analysis, data  handling,  and
reporting are considered, it makes  little sense  to invest
resources in a  study that lacks the planning needed to produce
reliable results.  Statistical designs must be incorporated into

the  plan at  the  outset;  thus,  the  statistician  and the
environmental scientist must  work together throughout  the study.
This  facilitates  the design  of data forms,  analysis of the data
and interpretation of results when the study  is completed.

     The  need for  a  valid statistical plan  cannot  be over
emphasized.  It is essential  to know the expected variability and
confidence limits  of both the analytical  methods used and the
sampling designs employed.  The sampling  designs must  take the
natural  variability of  the soil system into consideration.   Too
often there has been a tendency to do a "quick and dirty" study
with  no  design.   A few grab samples  taken at  some point  of
interest may provide some  information, but, more often  than not,
the  results of  these studies eventually come home to haunt the

     The  following section outlines the types of designs that can
be used in  soils work.   Four basic sampling  approaches are
presented below  -- simple  random, stratified random, systematic
and judgement sampling.  Judgement sampling is included  in this
discussion in order to complete the list of  options; however,  it
is not recommended as a viable  approach in most pollution control

     In this  report the  term sample is used  to describe the
individual  sample of soil  collected at a specific sampling site
or location.  The sampling site is that location within the study
area  that  is chosen by some random procedure  to  be the  location
from  which to collect a  particular sample of soil.  One can look
upon  the soils in the study area as an assemblage of all possible
samples  that might be collected from the area.  Sampling theory
is based upon the selection of  some subset of the total number
(N)  of samples by a random  selection process.  The object of the
sampling effort is to collect  a  prescribed  number  (n) of the
individual samples at randomly selected locations.  The number  of
samples needed to estimate the  pollution level with a  prescribed
precision will depend upon  the magnitude of  the variation within
the soil system.  In  a  relatively homogeneous soil,  a small
number of samples  may be  adequate  to satisfy the information
needs of the scientist.  A greater variation  will require more
samples to  reach the same  level of precision.

     One  technique that can help  reduce  the  effects  of the
variation  upon the statistical  analysis of the data is  to divide
the  sampling area into smaller, more homogeneous sub-areas called
strata. These strata are  defined by some  identifiable  boundry
that  is  based upon  topography,  soil  chemical or  physical
properties, or some stratigraphic feature. The identification  of
the  strata in an  area required a pilot study or prior knowledge
of the area if it is to be effective.   The soil population to  be
sampled  should  be  subdivided  into  sampling units that are  as
homogeneous as possible.   The  different  sources of  variation
within the  population should  be sampled if valid inferences are


to be  made  about pollution patterns  found  in the study  area
(Petersen and  Calvin,  1965).  This  division into relatively
homogeneous  sub-areas allows the  statistician to remove  a portion
of the variation and thus reduce the  statistical  error term in
the statistical  tests.  Stratification  often allows  a study  to be
conducted with  fewer samples or allows the  study  to reach
conclusions  with a higher statistical  precision.  Generally
speaking,  the  more stratification of  the  area,  the greater the
increase  in precision.   Petersen  and  Calvin (1965) noted,
however,  that  "The precision increases at a decreasing rate as
the strata are divided more  and more  until a point is reached
where no further  gain in precision is obtained."

    Environmental pollution  behavior often  is difficult to
understand without some  means of graphic display of the spatial
relationship of  the  data.   Maps  have provided a useful means of
viewing and grasping the data  collected in soil sampling studies.
Most mapping techniques use some  form  of  data  grid to  plot the
analytical results.  The use of the grid, which is a systematic
sampling design,  has evolved  as  a result of a desire to provide
sampling coverage for portions of the  entire  study area  rather
than at only certain randomly  selected  points.  Stratification by
soil types offers some  improvement over a simple  random sample
(see discussions  of  these  designs presented below)  but the grid
provides the most uniform coverage of the study area.  (Actually
the grid pattern is nothing  more than a  systematic or uniform
stratification of  the  area  into  blocks or sub-areas.) The
variance obtained by systematic sampling is often less than  that
derived from  simple random sampling.  Where plumes of  pollution
are expected,  this approach  appears to  be  the only  reliable
method for locating  the plume  and measuring concentrations in the
plume.  Another  advantage of the  systematic  sample  grid is  that
the data can be  easily mapped  by  most computer plotting  routines.
The  technique  called kriging  is most effective  when used in
conjunction with a systematic  sampling plan (see below for
discussion on  kriging) .

    The stratified  random sample  plan and  the  systematic  sample
plan can be considered  to be refinements in statistical designs
whose  purpose is  to  make the  survey more efficient.   This
efficiency may result from either obtaining  a  smaller  sampling
error with the same number of  samples or from reducing the number
of sample units required to  produce a specified sampling error.
Where the  scientist knows little about the area to  be sampled, a
preliminary study may be required.  This preliminary study should
be either  a simple  random design or  a  systematic design  with a
coarse grid,  if kriging  is to be used, a transect  of sufficient
length is  necessary  in order to conduct the calculations.

    Compositing of a number of subsamples is another technique
that is often used to  reduce the  effects of variation and  thus
increase  the precision of  the numbers obtained  during the
sampling study.    One  of the major advantages of compositing is
the gain in precision  obtained at no increase  in analytical cost.
Frequently soil scientists will collect a larqe number of samples
from a farmer's field.  These are then mixed in the laboratory and
an analysis performed  on  the composited sample.   If a number of
subsamples are analyzed from the composite sample, the range of
the value obtained decreases in proportion to the square root of
the number of sampling units contributing to the composite sample
(Cline, 1944).

    The problem with compositing of samples is the fact that only
an unbiased estimate of  the mean is obtained.  Additional data on
individual samples must be collected to augment the composite
sample data.  If any statistic other than the  mean is required, a
single composite sample  is completely inadequate (Cline, 1944).

    Compositing to  reduce costs assumes  that  the  soil is
homogeneous and therefore the number  of analysis required can be
reduced.  Compositing  done to reduce the variability in the  data
acknowledges that the variability  is present but chooses to
overcome  this by smoothing the effects of  the variation.
Pollution studies often use composite samples  in order to reduce
costs  but  in the process the very data desired is  lost.   The
environmental scientist is looking for the presence of chemicals.
If a small area of contaminated soil is composited with a  large
volume of uncontaminated soil the resulting analysis  often is
below  the  minimum detection limit of the analytical methods;
thus,  valuable data  is lost and an erroneous  conclusion may be

    With this  basic background on the statistical concepts used
in soil sampling  in mind,  each of the  statistical designs are
discussed  in the following subsections.    The  first   two
subsections are  based primarily on Peter sen and Calvin (1965) and
Cochran  (1965)  while  the remaining sections  are a compendium of
information from a number of the  sources listed in the Reference
6.2 Simple  Random Sampling

    A random sample is any sample in  which  the probabilities of
selection are known.  Random samples are selected by some method
that uses chance as the determining  factor  for selection.  The
chance mechanism used may range from  a simple  "toss of the coin"
to the use  of a random number  table.  The choice can be one of
convenience  as long as chance is the  means used to make the final
sample selection.  The chance of selection of any individual in


the population can be calculated using the laws of  probability.
The random sample by definition is free of selection bias.

    Simple random sampling is  a limiting case of  random sampling.
In simple  random sampling of soils, the chances  of selection of
any particular segment  of the soil  system must  be the same, in
other words each member of the soil population must  have an egual
probability for selection.  If a two inch core sampler is used to
sample  the soil,  the  total number of  possible samples  is
determined  by dividing the total area of the study  boundaries by
the cross sectional area  of  the soil  core.   For example a one
square  mile area would contain approximately  1,278,000,000
individual soil samples (640 X 43,560 X 144) / (1  X 1 X n ).

    Simple  random  sampling  is  the basis for all probability
sampling  techniques used in soil  sampling and serves  as a
reference point from which modifications to increase  the
efficiency  of sampling are evaluated.  Simple random sampling in
itself may not give  the desired  precision because of the large
statistical variations encountered in soil sampling; therefore,
one of  the  other designs may be  more useful. Where there is a
lack of information about  the area  to  be studied or about the
pollution distribution,  the simple random sampling design  is  the
only  design other  than the  systematic grid that can  be  used

    In soil sampling,  the unit of soil  taken from the  area is
usually a  volume of soil, i.e.,  a core, a  cube of  soil or a
shovel  full  of soil.   Occasionally there is a need to determine
the deposition of  a particular pollutant  on a per unit  area
basis.  In this case a known area  of soil is  collected  for  the
sample.   This has been done with radioactive fallout in the past.
Results of soil sampling programs are usually expressed in either
a per unit  volume,  per  unit  area, or per unit weight.  The bulk
density of the soil  is  the common  denominator for all three of
these units.  If conversions  between these  units  are planned,
several measurements of bulk density should be made.
    6.2.1 Determination of  the  Number of Samples Required

    The procedures used  in this section for determining  the
number of  samples required to meet  a  predetermined precision is
the basis  for  the  allocation of samples to a strata in  the
stratified random design and can  be used to determine the number
of sample points  required  in  the systematic sample  design;
therefore,  the  information  in this section will only be presented
once in this report.

    The number  of  samples required  to  obtain a given precision
with a specific  confidence level  can  be obtained from equation
6.2.1 if  some measure of the variance can be  obtained from either
a preliminary experiment, a pilot study, or  from the literature.
References  such as Beckett and Webster  (1971) and Mausbach et al.
(1980)  can  be used as a first approximation  of the variance  of
soil samples.  This can be used to develop  the initial estimate
of the  number of samples  needed.  A preliminary study will then
further refine  this  number once an estimate  for the variance  of
the soils in the specific area is known.

                          n ' £*2/*2                    (6.2.1)

     Where D is the precision given in  the specifications of the
study;  s2  is the sample variance  and t  is the  two-tailed t-value
obtained  from the  standard statistical  tables at the a  level  of
significance  and  (n-1)  degrees  of  freedom.   D  is usually
expressed as +  a specified number of concentration units (i.e. +
5.00 ppm) .  Equation 6.2.1 can also be  written in terms of  the
coefficient of variation (CV).   This  conversion yields Equation

                        n  =  (CV)2ta2 /p2                (6<2>2)

         where     n = number of  samples
                  CV = coefficient of variation
                  v = mean of the samples
                  p = allowable  margin_of error expressed
                      as a percent (D/y).
                  t = the two-tailed t value obtained
                      from standard statistical tables at
                      the a level of significance  and
                      at (n-1)  degrees of freedom.

     Since  the  t-value is dependent  upon  the  number of degrees of
freedom,  it is  necessary  to  use  an iterative  approach to arrive
at the  number of  samples to use.   Curves  can be  prepared that
plot the number  of  samples against the  coefficient of variation
and thus  avoid  the bother of the  iterations.

     Use of this  equation assumes  that  the population  is
normally distributed and that  less than 10% of  all  possible
samples  in the  study  area are being  collected.  The latter
criteria  is seldom exceeded in  soils  sampling.   (In those very
limited  situations  where  this may be the  case,  the finite
population correction must be applied.  This  correction, (N-n)/N,
is  multiplied by  the  variance obtained  from  the  sampling

    The environmental scientist can gain  more  information on the
sampling error  if more than one sample is  taken at each location.
These replicates are used to provide a measure of the  sample to
sample variation.
     Cost of Collection
    Determination  of  the number of samples  in  the above section
is based upon  the coefficient  of variation of  the sample
population.   There are many cases  where the number of  samples
required  by  this method  is not acceptable  because of the cost of
sample collection,  the cost of analysis or  limitations imposed by
the lack of  available laboratory capacity to  handle the analyses.
The following paragraph outlines  a means for integrating the
costs with  the precision of  the  estimates  obtained  by the
sampling program.

    The total cost  of soil studies often follows a linear form of
equation similar  to equation 6.2.3.  (After Petersen  and  Calvin,

                       C = C  +  nC   + nC                 /£ « ,.
                           o      s     a                (6.2.3)

               where     n = number of samples
                         C = total costs
                       Co = overhead or fixed costs
                       Cs = cost of sampling
                       Ca = cost of analysis

The equation is  used with equation 6.2.2 to  arrive at the number
of samples  that will  satisfy the  budget and  still  have an
identified precision.

     EXAMPLE:   Samples costs (Cs) are $1800 for  collection,
     preparation  and shipping. Fixed costs  (Co)  are $15,000.
     Analytical costs  (Ca)  are $2,000. The budget  for the
     study  is $75,000.  The  estimated coefficient  of
     variation obtained from another similar  study conducted
     nearby  was  25%.  The precision desired  on  the  results
     is +10% at a 95% confidence level.

         Equation  6.2.2  indicates  that approximately  26
     samples should be  taken.  Equation  6.2.3 however
     indicates  the following:

                  C = C  + nC  +  nC
                       o     s    a
                  C = CQ + n(Cg + Ca)

                  n =  (C - CQ)/(Cs + Ca)

                  n =  (75,000 - 15,000)/(1,800 + 2,000)

                  n = 15.8  which is rounded down to 15

    The effects of  the budgetary constraints  must be resolved
either by reducing the precision or  else by increasing the
budget.  Assuming that  the budget  cannot be changed,  equation
6.2.2  will again  be used to arrive at  the  t  value that would
result from  the use of the smaller number of  samples.

                    n =  (CV)2t2/p2
                   15 =  (25)2t2/102

                   t2 = 2.4000

                    t =  ti  = 1.5491

This value for  t is obtained from  the statistical t—tables for  a
two-tailed t-test  for 14 degrees of  freedom (n-1).   This value
indicates that  the significance level  for the test would have  to
drop to 85% with the smaller number of  samples or  the  allowable
margin of error (p) would have to  be increased.
     6.2.2 Location of  Sampling Points

    Once the  number of samples is determined their location  can
be planned.   A  map  of the study area  is overlain with a grid of
an appropriate scale.  The  starting point of the grid should be
randomly selected rather than located for convienence.  This  can
be accomplished by  selecting four random  numbers from a random
number  table.   The  first  two  numbers  locate  a specific grid
square on the overlay.  The second  two identify a point within
that grid  square.  This point is fixed on the map and the entire
grid shifted  so  that the lower right corner of the original grid
square lies on the point chosen.  This procedure is simple  and
fast.   Using this  technique avoids the questions that are often
raised about bias.  A second alternative  is to  select two  map
coordinates at random.   This becomes the starting point  for  the
grid used  in sampling.   All lines are  then laid out on the  map
overlay starting at that point.

    The grid  prepared  in  this fashion  becomes the basis for  the
selection of  the sample locations.  Using  the number of  samples


(n) determined  in  Section 6.2.1, n pairs of random numbers  are
selected  from  a random number table.  These  pairs of numbers
become the X  and the Y coordinates of  the sample location.  This
procedure is  the basis for locating  sampling points in all of  the
methods where random samples are collected. In situations similar
to Love Canal, a house lot is the  area  to be represented by each
sample.   The grid  intersections can be used to locate the houses
to sample  or a  listing of the houses can  be  prepared and  the
individual samples  identified by a random number procedure.
6.3 Stratified  Random Sample
    Prior  knowledge of the sampling  area and information obtained
from the  background  data can be combined  with  information on
pollutant  behavior to reduce  the  number of samples necessary to
attain  a specified precision.   The statistical technique used to
produce this  savings is called  stratification.   Basically it
operates on  the  fact that environmental  factors play a major  role
in leaching and concentrating pollutants  in certain locations.
For example, a pesticide  that is  attached  to clay particles may
accumulate  in  stream valleys because of soil  erosion from
surrounding agricultural lands.  The agricultural land may  have
lost  most of  the pesticide  because of the  same  erosion.
Stratification in this case might be along  soil  types or along
elevational changes.   Soil types are frequently used as a means
of stratification,  especially if  they are quite different in
physical and chemical properties.

    Examples of  factors used for stratification are:
     Soil  type - Comus silt  loam  and Baile silt loam  (The
                Comus contains mica  that is known to bind  a
                number of pollutants.)

     Texture   - Sandy loam and clay  loam

     Drainage  - Stream bottom, valley slope and ridgetop

     Uses      - Cropland and fence rows

     Practices - No till cropland  and plowed land

     Horizons  - A horizon  and C horizon (Surface  (A)
                usually has  more  organic matter)
    The whole purpose  of stratification  is  to increase the
precision of  the  estimates made by sampling.   The stratified
random sampling plan should lead  to this increased precision  if


the strata are  selected in such a manner that  the  units  within
each  stratum  are  more homogenous than the total population.
Stratification must  remove  some of the  variation  from the
sampling  error  or else there is no  benefit from  the  effort.

     In general,  the more  stratification,  the  greater  the
increase  in precision.   As was mentioned earlier, Petersen and
Calvin (1965) have pointed out  that the benefit  of stratification
has a limit where the  law of diminishing returns takes over and
no further gain in precision is encountered.

    At least two samples must be taken from each stratum in order
to be  able to  obtain an estimate of the sampling error.   The
number of sampling  units is usually allocated according  to a
proportion based on the land area covered by each stratum.  (i.e.
if the area of soil  in one stratum is 25% of  the total study
area, then 25%  of the  samples would be taken from that  stratum.)
Proportional allocation is used in soil sampling work primarily
because the variance within  a  general  area  tends to be constant
over a number  of  soil types.   A pilot study  would  allow  the
scientist to  determine if this is in  fact the case.   If the
variances are materially different, the allocation must be on the
basis of  optimum allocation.

    The procedure used once  the number of  samples  is determined
is the same as  that outlined in Section 6.2 for  the  simple random
design.   Each  stratum is handled as a separate simple  random
sampling  effort.
6.4 Systematic  Sampling

    The systematic sampling plan  is an attempt to provide  better
coverage of  the  soil  study area than could be provided with the
simple random sample.  The method is easy to use therefore it has
been popular  in many cases.  Samples  are  collected  in a regular
pattern (usually a grid or a line transect)  over the  areas  under
investigation.   The starting  point is located  by  some  random
process;  then  all  other  samples are collected  at regular
intervals  in  one or more directions.  The orientation of the grid
lines should  also  be randomly  selected.  This  creates problems
however  when  a pollution  plume  is  the  subject  of  the
investigation.  The orientation of the grid should be  such  that
the lines  in one  direction are parallel to the general trace of
the plume.  This is especially important  if kriging is going to
be used.

    The spacing  on  the grid  also becomes  important  if
regionalized variable theory  (this is the basis of kriging) is
used to design the study.  The theory  is  based upon the spacing
of data points along the grid lines.  The samples must be  close


enough  to provide a measure of  the continuity of the  location to
location variation within a soil sampling unit.   If on  the other
hand a measure of the mean and variance of the population is the
focus of the grid  sampling array, the samples must be placed
outside of the  "range" of the variance of  each point.  This
allows the environmental scientist to collect  samples that are
not  influenced  by  the regionalized  variables.   Beckett  and
Webster  (1971) indicate that about 50% of the reported  variation
occurs  within  the  first  few meters of a point.   This would
indicate that the range beyond  which kriging is not effective
probably lies  at  a distance  of approximately ten meters or
greater.  Beyond this distance  the mean and  variance of the
population are the only parameters  that can be determined.

    A number of studies  are reviewed by Petersen  and  Calvin
(1965)  that have  compared systematic sampling with  a simple
random or a  stratified random sampling plan.   The results  favored
the  systematic sampling in nearly all cases.  The optimum
sampling is  obtained with a triangular grid design located over
the  area, but  the  square grid  is almost as  efficient.  The fact
that the square grid is probably  easier  to  set  out in  the field
would suggest that a square or rectangular grid should be used
unless  there  is  some  reason  for  desiring to optimize  the
placement of sampling points

    The systematic sampling plan is ideal when a  map is  the final
product. This provides a  uniform  coverage  of the area and also
allows the scientist to have points to use in developing the map.
(Most mapping techniques use a grid to generate the  points for
plotting isopleths of concentration, etc.)

     The location of  the  grid on  the area would be according to
the  procedures  outlined in Section  6.2.2.  At  each grid
intersection samples would be collected according to  one of the
methods outlined  in  Section 7.   It is desirable   to collect
duplicate samples at some of the locations in order to  provide a
measure of the sampling error.  This will increase the precision
of the estimate of concentration and also allow the researcher to
check the reliability of the sampling at the  same time.

    There are two problems that may limit the use of this  design.
First,  the  estimation of the  sampling error  is difficult to
obtain from  the sample itself unless double sampling is  used at a
number of sites.  The variance cannot be  calculated  unless some
method of mean successive difference test is  used to evaluate the
data.  The second problem area concerns the presence of  trends
and  periodicity in the data. Both of these  create problems when
the direction of  the  grid aligns with the pattern in  the data.
Soil sampling seldom encounters  the cyclic pattern to  a degree
that a  problem is  created.   Trends however  are common  in soil
pollution work.  That  is the whole purpose for  the  sampling in
many cases.  There  are a whole  array of methods available  for
handling the  analysis of data from sequential sampling.   An


excellent reference for soil scientists working in this area  is a
book by  John C. Davis (1973)  entitled  Statistics and Data
Analysis  in  Geology.  Davis spends considerable  time discussing
the analysis of sequences of data.  Techniques such as least
squares  analysis,  regression,  filtering or time-trend analysis,
autocorrelation, cross correlation, Fourier transformations,  map
analysis ,   nearest neighbor  analysis,  cluster  analysis,
contouring,  trend  surface analysis, double  Fourier series  and
moving  averages  are presented.   Kriging and multivariate analysis
are also  discussed. A valuable addition to this text is a series
of Fortran  computer  subroutines  for conducting most of these

       Yates (1948)  and Quenouille  (1949) present  excellent
reviews  of  the  use of systematic sampling  from a statistical
point of  view.
6.5 Judgemental  Sampling

    This technique is often used with one of the other methods  in
order to cover areas of unusual pollution levels or where effects
have been  seen  in  the past.  The problem  with the approach  is
that it tends to  lead to sloppy science and to wrong conclusions.
The scientist's  own  bias is built into  the  sampling effort and
the data therefore often suspect.  Where  the data has a potential
for litigation  or  where there is a  likelihood of  emotional
reactions to  the  results,  this system  should be absolutely
avoided.  A simple  random design with a known  precision can  be
developed that will allow the scientist to determine the presence
of pollutants without the risk of creating problems that cannot
be handled.  If  it  is essential that judgemental sampling  be
used, duplicate or triplicate samples should be taken in order  to
have some measure of precision.
6.6 Phasing  the Study

    Often data  is not available for use in planning a study  in a
particular area.  This  type of  situation  leads to a phased
approach.  The  first phase of the study might be a simple random
study design with  a 68% confidence level.  The results of  this
study would then be used to design a more definitive study with a
95% confidence  level.  This  latter study could use a stratified
random design or a  systematic sampling grid.   The grid design
would allow  the researcher to analyze the data using kriging and
thus find  where additional  samples are needed to further refine
the sampling design so that the entire area is covered at the 95%
confidence level.


    Careful planning can provide data at each phase  of  the study
that  can stand  the scrutiny  of the  scientific and  legal
communities  and at the same time  not place all  of  the resources
into  a  one shot  study  that does not meet  the situation at a
particular site.  Planning takes  time, but it will  pay off  in the
long run by providing  the data needed at a precision that is
acceptable  to most scientists.  The  use  of phases can greatly
help in  this process  by  allowing  the  data to grow as  the
awareness of the study situation  evolves.
6.7 Control Areas
    Control sites are  used  quite  often in major soils studies
especially  if  the study is attempting to determine  the extent and
presence of local pollution.   Sites  for controls must  be as
representative as possible of the study  area.  A careful  survey
of the area should be made prior  to the  final selection.  In most
cases  it is desirable   to spend as much time searching out data
on the control as on the study area.   The purpose  of the control
area is to  serve as a base line against  which the  results  of the
soil sampling  study can be compared.

    Soil type should be  the main factor chosen  in selecting the
control but factors such  as  depth to  groundwater,  location in
relation to pollution sources and vegetation  type  all  should be
taken  into consideration  in  making  the  selection.   Where
pollution sources are being studied the ideal selection would be
a control site that only differs  from the study area by  the lack
of the  pollution source under  investigation.  This  is  seldom
possible but  every  attempt  should be made to reduce the factors
that are different.

                          SECTION  7

                      SAMPLE COLLECTION
    There are two portions  of  the soil that are important to the
environmental  scientist.  The  surface layer  (0-15 cm) reflects
the deposition of airborne pollutants; especially those recently
deposited pollutants.   Pollutants that have  been deposited by
liquid spills,  or  by long  term deposition  of  water  soluble
materials may  be found at depths ranging up to several meters.
Plumes emanating  from  hazardous waste dumps  or leaking storage
tanks may be  found  at considerable  depths.  The methods of
sampling  each  of these are slightly different;  but, all make use
of one of two basic techniques.  Samples can either be collected
with some form of core sampling or auger device;  or, they may be
collected by use of excavations or trenches.  In the latter case
the samples are cut from the  soil mass with  spades  or short
punches.  The American  Society for Testing and Materials (ASTM)
has developed  a  number of methods that have direct application to
soil sampling.  These often  need to be modified slightly to meet
the needs of the environmental  scientist that  requires  samples
for chemical analyses  since the ASTM methods are designed
primarily for engineering tests.   The  technioues that are
utilized should be  closely coordinated with  the  analytical
laboratory in order to meet the specific  requirements  of the
analytical methods used.

    The methods outlined below are  for the collection of soil
samples alone.  At times  it  is  desirable   to collect  samples of
soil water.   In these  cases use can be made  of  some form of
suction collector.  The statistical designs would be the same no
matter which  of the soil water collectors was used.  In  those
cases  where suction devices  are used, the sampling media is water
and not soil even though the  samples  are a good reflection of
soluble chemicals  that  may  be  moving through  the soil  matrix.
These  methods  are not discussed in this report.

7.1 Surface  Sampling

    Surface  soil  sampling  can be divided into two categories —
the upper 15  cm  and the upper meter.  The very shallow pollution
such as  that found downwind from a new  source or at sites of
recent spills of relatively insoluble chemicals can be sampled by
use of one of the  methods listed  in Section  7.1.1.  The deeper
pollutants found  in  the top meter are the more soluble,  recent
pollutants or those that  were  deposited on the surface a  number
of years ago. These  have begun to move downward into the deeper
soil layers.  One of the methods in 7.2 should be used in  those
    7.1.1 Sampling  with  a Soil Punch

    A number  of studies of surface  soils have made use of a punch
or thin walled steel  tube that is 15 to 20 cm  long  to extract
short cores  from the soil.  The tube  is driven into the soil with
a wooden mallet;  the core and the  tube are extracted;  the soil
is pushed out of the tube into a stainless steel mixing bowl and
composited with other cores.  Two alternates are the short
King-tube samplers or the tube type density samplers used by the
Corps of Engineers.  (These sampling devices can be supplied by
any  field equipment company  or by agricultural  equipment
companies.)   The latter sampler  is machined  to  a predetermined
volume  and  is designed  to be handled and shipped as a soil-tube
unit.  A number of similar devices are  available for collecting
short cores  from surface soils.

    The soil punch  is fast and can  be  adapted  to  a number  of
analytical  schemes provided  precautions  are taken to avoid
contamination during shipping and  in  the laboratory.  An example
of how this  method can be adapted would be  to use the system to
collect  samples for volatile organic chemical analysis.   The
tubes could  be sealed with a Teflon  plug and coated with a vapor
sealant  such as paraffin  or,  better  yet,  some non-reactive
sealant. These tubes could then be decontaminated on the outside
and shipped  to the laboratory for analyses.
     7.1.2  Ring Sampler

    Soil engineers  have a tool that can  be  purchased from any
engineering  equipment supply house that can be used to collect
larger surface samples.  A seamless steel ring, approximately 15
to 30 cm in diameter, is driven into the soil to a depth of  15 to
20 cm.  The ring is extracted as a soil-ring  unit and the soil


removed  for analysis.  These  large cores should be used where the
results  are going to be expressed on a per unit area  basis.  This
allows  a constant area  of soil  to  be collected each time.
Removal  of these cores is often difficult  in very loose sandy
soil and in very  tight clayey soils.  The  loose soil  will not
stay in  the ring.   The clayey soil is often difficult  to break
loose from the underlying soil  layers  thus  the ring  must be
removed  with a shovel.

    This device has not been used  extensively  for collecting
samples  for chemical  analysis but the technique should offer a
useful  method  for  collecting  samples either for area
contamination measurements  or for taking large volume samples.
    7.1.3 Scoop or Shovel  Sampling

    Perhaps  the most undesirable   sample collection  device  is the
shovel or  scoop.  This technique  is  often used in agriculture but
where  samples  are  being taken  for  chemical  pollutants, the
inconsistencies are too great.  Samples can be collected using a
shovel or  trowel if area and/or volume are not critical.  Usually
the shovel  is used to mark  out a boundary of soil to be  sampled.
The soil  scientist attempts  to take a constant depth of  soil but
the reproducibility of sample  sizes  is poor;  thus the variation
is often  considerably greater  than with one of the methods  listed
7.2 Shallow Subsurface Sampling

    Precipitation may move surface pollutants into the  lower soil
horizons or move  them  away from the point  of deposition by
surface runoff.  Sampling pollutants  that have moved  into the
lower  soil horizons requires the use  of a device that  will
extract a longer core than can  be obtained with the short probes
or punches.  Three  basic methods are used  for  sampling  these
deeper soils:

             • Soil probes or  soil augers
             • Power driven corers
             • Trenching

    The soil probe  collects 30 or 45  cm of soil in intact,
relatively undisturbed soil cores whereas  the  auger collects a
"disturbed" sample  in approximately the same increments as the
probe.   Power  augers can use split spoon  samplers to extract
cores up to 60  cm long.   With special attachments longer  cores
can be obtained with the power auger if this is necessary.


     The requirement  for detail often desired  in  research studies
or in cases where  the movement of the pollutants  is  suspected to
be through very narrow layers cannot be met effectively with the
augers.   In these  cases  some form of core sampling or trenchinq
should be used.
    7.2.1 Soil  Probes and Hand Augers

    Two standard tools  used in soil sampling are  the  soil probe
(often called a King-tube) and the soil auger.   These tools are
designed  to acquire  samples from the upper two  meters of the soil
profile.   The soil probe  is nothing more than a  stainless steel
or brass  tube that is sharpened  on  one end  and  fitted  with a
long, T shaped handle.  These tubes are usually approximately 2.5
cm inside diameter although larger  tubes can  be  obtained.  The
cores  collected by  the tube sampler or soil probe are considered
to be "undisturbed"  samples although  in reality this is probably
not the case.   the tube is pushed into the soil in approximately
20 to  30  cm increments.  The soil core is then removed from the
probe and placed in  either the  sample container  or in a mixing
bowl for  compositing.

    The auger is approximately 3 cm in diameter  and  is used to
take samples when the  soil probe will not work.   The samples are
"disturbed";  therefore,  this method  should not  be used when it
is necessary to have a  core to examine or when very fine  detail
is of interest to the scientist.   The auger is  twisted or screwed
into the  soil then extracted.  Because of the length of the auger
and the force required  to pull the soil free, only about 20 to 30
cm maximum  length  can be extracted  at one time.  In very tight
clays it  may  be  necessary to limit the  length of each pull to
about 10  cm.  Consecutive samples  are taken from  the  same hole
thus cross  contamination is a  real  possibility.  The soil is
compacted  into the  threads of  the auger and must be extracted
with a stainless steel  spatula.

    Larger diameter augers  such as the  bucket auger,  the Fenn
auger and the blade  augers can also be used if  larger samples are
needed.  These range in size from 8 to 20 cm in diameter.

        If distribution of pollutant with depth is of  interest,
the  augers  and the  probes  are not recommended because they tend
to contaminate the lower samples with  material from the surface.
The probe is difficult  to decontaminate without long bore brushes
and some  kind of washing facility.  One alternative  is to take
several waste cores at each site prior to collecting the actual
samples.  This  allows the  probe tube to be cleaned  by the
scouring  action of soil at similar concentrations  to those found
in  the sample taken.   This should  remove  any  contamination


leftover  from previous locations.  Where there is  a potential for
litigation, decontamination is essential to avoid any question
about cross contamination.   The augers have some of  the  same
decontamination  problems but  the  open thread  surfaces allow
easier access to  the collection surfaces;  therefore,  they are
easier  to  clean.   See Section  7.8  for more  detail on
decontamination procedures.

    One final warning about  the use of the hand  augers and  soil
probes.   There are many soil  scientists with back problems  that
have resulted from  trying  to extract a  tool  that has  been
inserted too far  into  the  soil.   A foot jack  is a necessary
accessory if these  tools  are to be used.  The foot jack allows
the tube  to be removed  from the soil without use of  the  back
    7.2.2 Power Augers and  Core  Samplers

    These truck or tripod  mounted  tools are used  for  collecting
samples  to depths greater  than approximately 30 cm.  Standard
ASTM methods  for  use of these tools  are available  from the
American  Society for Testing  and Materials or  can  be found at any
college or university library.  The methods outlined  in  Section
7.3  are  applicable in  this  case  and  will not be discussed
    7.2.3 Trenching

    This method of soil  sampling  is used to carefully  remove
sections of  soil during studies where a detailed  examination of
pollutant migration  patterns and detailed soil structure  are
required.  It  is perhaps the  least cost effective  sampling method
because  of the relatively high cost of excavating  the trench from
which the samples  are collected.   It should therefore be used
only in  those cases where detailed information  is  desired.

    A trench  approximately 1 meter  wide is dug to  a  depth
approximately one  foot below the desired sampling depth.   The
maximum effective depth for  this method is about  2 meters unless
done in  some stepwise fashion.  Where a number  of  trenches are to
be dug,  a backhoe can greatly facilitate  sampling.  The samples
are taken from the  sides of  the  pit using the soil punch or a

    The sampler  takes  the surface 15 cm sample  using the soil
punch or by carefully excavating a 10  cm  slice of soil that is  10
cm  square on  the surface.  The  soil can  be treated as  an
individual sample  or composited with other samples collected from
each face of the pit.   After  this  initial  sample is  taken the
first layer is  completely cut back exposing clean soil at the too
of  the  second  layer  to be sampled.   Care  must be exercised  to
insure that the sampling  area is clear of all material from the
layers above.   The punch or trowel is  then  used to take  samples
from the  shelf created by the  excavation  from the side of the
trench.  This process  is repeated  until all  samples are taken.
The resulting hole appears as a set of steps cut into the side  of
the trench as is  shown in Figure 7.1.

    An alternate  procedure that  is  also  effective results  from
using  the  punch  to remove soil cores  from the side of the trench
at each depth to  be sampled  (Figure 7.1).  Care must be taken  to
guard against soil sloughing down the  side of the hole.  A shovel
should be used  to  carefully clean the  soil sampling area prior  to
driving the punch  into the trench side.
7.3 Sampling  for  Underground Plumes

    This type  of sampling is perhaps  the most difficult of all  of
the soil  sampling methods.  Often  it  is  conducted along with
groundwater  and hydrological sampling.  The equipment required
usually consists  of large, vehicle mounted augers and coring
devices although there are some small tripod mounted coring units
available  that can  be carried by several men using backpacks.
    7.3.1 Usual Procedure for Underground Plume Sampling

    The procedure  listed  here closely follows ASTM method
D1586-67 in  many respects.  The object of  the sampling is to take
a series of  45.7 cm (18 in) or 61 cm  (24 in)  undisturbed  cores
with a  split  spoon sampler.  (Longer cores  can be obtained  by
combining several of the  shorter  tubes  into one  long split
spoon.)  A  15.2 cm (6 in) auger is used to  drill down to the
desired depth  for sampling.  The split  spoon  is then driven  to
its sampling depth through the bottom of  the augered hole and the
core extracted.

    The ASTM manual  calls for  the  use  of  a 63.5 kg  (140 Ib)
hammer to drive the split spoon.  The hammer  is allowed  to  free
fall 76 cm  (30  in)  for each  blow to the spoon.   The number  of
blows required  to  drive  the spoon 15.2  cm (6  in)  is counted and
recorded.  The  blow counts are a direct reflection of the density



Figure 7.1  Trench  amp!ing techniques


of the soil and can be  used  to  obtain some information on the
soil structure  below surface.   Unless this density information is
needed  for  interpretive purposes, it may  not  be  necessary to
record the blow counts.  In soft  soils  the split  spoon  can often
be forced  into the ground by  the hydraulic drawdown on  the drill
rig.   This is faster than the  hammer method and  does not  require
the  record  keeping necessary to record  the blowcounts.  Most
commercial drilling  companies have the equipment and  the
experience  required  to conduct this  type of sampling  with some
supervision from the field scientist.

    Samples should be collected at least every 1.5  meters  (5 ft)
or in each  distinct  stratum.  Additional samples should  be
collected  where sand  lenses  or  thin silt and sand  layers appear
in the profile.  This sampling  is  particularly important when
information on pollution migration is critical.   Soluble
chemicals  are  likely  to move through permeable layers  such as
sand  lenses. This  appears to be especially important in tight
clay  layers where the main avenue of water movement is through
the porous  sandy layers.

    Detailed core logs should be prepared by the technical staff
present  at  the  site during the sampling operation.  These logs
should note  the depth of sample,  the length of the  core and  the
depth of any features of the soil such as changes in physical
properties, color  changes, the presence of  roots,  rodent
channels,  etc. If chemical  odors are noted or unusual color
patterns are detected,  these should be noted also.   Blow  counts
from  the hammer  should  be recorded on the log along  with the data
mentioned above.

   The  procedure using samples collected every 1.5  meters (5 ft)
is most effective  in  relatively homogeneous soils.  A variation
in the method that is preferred by soil scientists  is to collect
samples of  every distinct layer in the soil profile.  Large
layers may  be  sampled at several points if they  are  unusually
thick.  A disadvantage  of this  approach is the  cost for  the
analyses of  the additional samples acquired at  a more  frequent
interval.   The soil horizons or strata are the avenues through
which chemical  pollutants are likely to  migrate.   Some are more
permeable than  others and are  thus more likely to contain  traces
of the chemicals if they are  moving through the  soil.  Generally
speaking the sands  and gravels are more prone  to  contamination
than  are the clays because of  increased permeability.  This  is
especially  true  out on  the leading edges of the plume and shortly
after a pollutant begins to  move.   Low levels  found  in  these
layers can  often serve  as a  warning of a potential problem at a
later date.

   Decontamination of the large equipment  required  for plume
sampling is difficult but necessary  if  the  study  is to  be
useable.  The  staged  sampling using  the auger  then the  split


spoon helps  reduce  the chances of serious cross  contamination.
The auger  carries  considerable soil in the threads of the bit.
This can only be removed with  high pressure hoses.

    A disadvantage of this type of sampling is  the  impact  of  the
vehicle on yards  and  croplands.  Special care must be taken to
protect yards,  shrubs, fences  and crops.  The  yards must be
repaired,  all holes backfilled and all waste removed.  Plastic
sheeting  should be  used under all  soil handling operations such
as subsampling, compositing and mixing.
    7.3.2 Variations  in  the  Procedures
    There are several variations for  split spoon  sampling.
Samples collected  from soils below the water  table or  in  very
soft soils  may  require the use of split spoons  equipped  with
retainers in  the  end  of the spoon.  The retainer  is made with
flexible fingers that close over  the end of the tube  as the spoon
is retracted from  the soil.

    Samples collected for  the  analysis  of volatile  organic
chemicals pose a problem to the environmental scientist.   The
volatile chemicals  can be lost during transport and handling.
One option that may offer  a  solution  to this problem  is the use
of brass,  stainless steel or Teflon liners in  the split spoon.
Brass liners are available from most engineering and  agricultural
supply  houses.  The  liners are easily removed when  the  split
spoon  is opened.  The liner tube can be sealed with  Teflon plugs
and some form of sealant applied over the plug.  The method is
currently used for moisture determinations in  agricultural and
research situations.  This system avoids the problems of  the loss
of chemicals  that volatilize into the headspace of  the sample
jars.  The liners  can  be discarded after analysis  if necessary
thus reducing  the  labor costs required to clean the tubes.

    The main disadvantages of using  this modified system  is  that
no  core log  can  be prepared of the sample.  The author was
informed that some laboratories are reluctant to develop methods
that can make  use of samples acquired in this  fashion.
7.4 Compositing

     Many  sample plans call  for  compositing of  the  soils
collected  at  a sampling location.  This creates  a problem from
the point of view  of  the  soil scientist.   The  key  to  any
statistical sampling plan is the use of the variation  within  the
sample  set to test hypotheses about the population  and to


determine  the  precision or reliability  of  the data set.  As was
mentioned earlier,  the  composite sample provides  an excellent
estimate of the mean but does not give any  information about  the
variation  within  the sampling area.   Section 7.4.1 discusses one
alternative that is  a combination of  the compositing methods and
random sampling with duplication. Three  methods that have  been
used to composite  soil are presented  below.
    7.4.1 Estimating  Sample Variance.

    The problem with  the statistical analysis  is  found in the
lack of duplication within the sampling location.  Each subsample
is combined  into  the composite therefore  the  data  that  is
contained in  the subsample is averaged with all other subsamples.
The lack of a measure  of  the sampling error  is the cause of  the
problem  confronting the  statistician.  Multiple samples taken at
each location would avoid this problem but costs usually preclude
this.   A compromise is possible by only analyzing duplicates or
triplicates at a percentage of the locations.  The exact location
is chosen by use of  a  random  number table and  should be
identified before  the  study begins.  The duplicates should not be
two subsamples taken from the same composite sample but should  be
made up of a  second set of subsamples.

    Large cores such  as  those collected by  split  spoon can be
split lengthwise in half.  Each half is thus used as part of two
separate composite samples.  This avoids  the time required  to
take  the  second  set  of cores  but  provides the duplication
necessary for calculating the sampling error.
    7.4.2 Compositing  with a Mixing Cloth

    Soil scientists often use a large plastic or canvas sheet for
compositing  samples in  the  field.   This method works reasonablv
well for dry soils but has the potential  for cross contamination
problems.  Organic  chemicals can create  further problems by
reacting with  the plastic sheet.   Plastic sheeting, however,  is
inexpensive  and can therefore be discarded  after each sampling

    This method is difficult to describe.  It can be visualized
if the reader  will think of  this page as  a plastic sheet.   Powder
placed in the center of  the sheet can be made  to  roll  over on
itself  if one corner  is carfully  pulled up and  toward the
diagonally opposite corner.  This process  is  done from  each
corner.   The plastic  sheet  acts the same way on the soil as the
paper  would  on the powder.  The soil can  be  mixed quite well if


it is loose.   The  method does not work on wet or heavy plastic
soils.  Clods  must be broken up before attempting to mix the

    After  the soil  is mixed,  it is again spread out on the  cloth
into a relatively  flat pile.  The pile  is  quartered.  A  small
scoop, spoon or  spatula is used to collect  small samples from
each quarter until  the desired amount  of soil is acquired  (this
is usually about 250 to 500 grams  of soil but can be less if the
laboratory desires a  smaller  sample).  This is mixed and placed
in the sample  container for shipment to the  laboratory.   The
waste material  not  used in the sample should be disposed of in a
safe manner.  This  is especially important where the presence of
highly toxic chemicals is suspected.
    7.4.3 Compositing  with a Mixing Bowl

    An effective field compositing  method has been to use  large
stainless  steel mixing bowls.   These  can be obtained from
scientific,  restaurant, or hotel supply houses.   They can be
decontaminated and are  able to stand  rough handling  in  the  field.
Subsamples  are placed in the bowls, broken up, then  mixed using a
large stainless  steel scoop.  The rounded  bottom of the mixing
bowl was designed to create a mixing action when the material in
it is turned  with the scoop.  Careful observance of  the soil will
indicate the  completeness of the mixing.

    The soil  is  spread  evenly in the  bottom of the bowl after the
mixing is complete.  The  soil  is quartered and a  small  sample
taken from  each  quarter.  The subsamples  are mixed together to
become  the sample  sent to the laboratory.  The excess soil is
disposed of as waste.
    7.4.4 Laboratory Compositing

    Small  sets of samples can often  be  composited better  in  the
laboratory  than  in  the field.   A number of  the small surface
cores discussed  in  Section 7.1.1 can  be placed in the sample
bottle for shipment to the laboratory.  These can then be placed
in a stainless steel  laboratory mixer and mixed to the  degree
needed by the analytical methods.   This  technique  is  the only
method that may be  useful for obtaining composite samples  for
some  types of soils  and  may be  the  best  method  to use if
compositing of samples is necessary  in a particular situation.

7.5 Replicate  Samples
    The quality  control  program  will require duplicate or
triplicate samples from a percentage of the sampling  sites. These
may be collected  from the composite or they may be comprised of
duplicate  sets of samples.   The  latter is the preferred method.

    A question often arises  about  how  to handle the analytical
data for  these multiple results.  All analytical  results for the
field replicates  should be reported.  Proper statistical  designs
can use this data  to increase the precision of the estimates
made.  There is  a  tendency on the part of many scientists to
discard unusual  results (outliers) and to average the remainder
of the samples.  The discussion  on soil variability given earlier
should point up the problem with this approach.  The  outliers are
probably part of  the normal,  wide variation seen in soils data.
Averaging  the numbers in effect  throws away data on the  sampling
error  that is needed to determine the reliability of the data
7.6 Miscellaneous  Tools
    Hand tools such as shovels,  trowels, spatulas,  scoops and pry
bars  are helpful for  handling  a  number of  the sampling
situations.  Many of these can be obtained in stainless steel for
use in sampling hazardous pollutants.  A set  of  tools  should be
available for each sampling site where cross contamination is a
potential problem.  These tool sets can be decontaminated on some
type  of schedule  in order to avoid  having  to purchase  an
excessive number of these items.

    A hammer , screwdriver and wire  brushes are helpful when
working with the split  spoon samplers.   The  threads  on  the
connectors often get jammed because of  soil in  them.  This soil
can be removed with the  wire  brush.  Pipe wrenches  are  also a
necessity as is a pipe vise or a plumbers vise.
7.7 Record Keeping

    One of the vital components of the protocol  is  to adequately
define the records  required during the study.   Good  records
become extra  important if  litigation  results from  the data
collected.  Every  sample will be questioned in an attempt to
either discredit or  verify the data depending  upon the side of
the issue the attorney represents.  Some of  the records  are
discussed  below.


    7.7.1 Log Books

    The sample  teams should maintain an official  log book  of  the
investigation.   Observations of the field  conditions, equipment
used, procedures  followed and crew  members  involved are recorded
for each days sampling.  These log books should be bound  and  all
data must be recorded in ink  (preferably  black ink) .  Each log
book should  be  maintained  by the crew  leader and signed by him.
No erasures are  allowed.  When  mistakes are made the  data  is
lined out with  one  line only and the corrected data entered above
the incorrect entry or on the next line of the log.
    7.7.2 Site Description Forms

    These serialized  forms record the conditions  at each  site at
the time the samples  are collected.   A sketch  map and photographs
of the site  should be a part of the  description.  A Polaroid-type
camera  should  be used so that  the  pictures  of  the sites can be
checked before  leaving the area  of  the sample collection.  These
forms and the back of the photographs should be signed  and  dated
by the  crew leader responsible for  taking  the samples.  The NEIC
site description form should be used in  most  cases  where the
USEPA is involved.
    7.7.3 Sample  Tags

    Tags made up according to the specifications provided by NEIC
should  be  printed for use  in  the  soils study.  A  tag  must be
prepared for  each  sample.   All data must be  included on the tag
at  the  time  the sample is  collected.   Wet samples should be
double  bagged with  the  tag  in  the outer bag.   The person
collecting  the sample  should sign the tag.
     7.7.4 Chain-of-Custody Forms

    This form is  perhaps one of  the  most important as far as the
legality of the samples is concerned.   Chain-of-custody  traces
the possession of the sample  from  its origin  through  to data
analysis.  Most field  researchers are not accustomed to observing
the care needed to insure the safe custody of  their samples.  The


samples must be  in  the  the  physical custody of the scientist
collecting the  sample  or else  be secured in a facility with
controlled,  limited access until the  samples  are signed for  and
transfered  to another  responsible  party.   Samples must not be
left unattended  in an unlocked vehicle for  any reason.  There is
nothing  more disconcerting to technical representatives of  the
regulatory  agencies  than to  spend hours working  with data
collected  by  field  teams  and  then find  the data  is open to
question because  the chain-of-custody had been  violated.   Samples
are a valuable  resource and should be treated accordingly.
7.8 Decontamination
    One  of  the major difficulties  with  soil sampling arises  in
the area of cross contamination  of  samples.  The most reliable
methods  are those  that  completely isolate one sample from the
next.   Freshly cleaned  or  disposable  sampling tools, mixing
bowls,  sample containers etc.  are the  only way to insure the
integrity of the data.

    Field decontamination is quite difficult to carry out,  but  it
can be done.  Hazardous chemical sampling adds another layer  of
aggravation to the decontamination procedures.  The washing
solutions  must be  collected  for disposal at a waste disposal
site.  The  technique outlined below has  been used under  field
    7.8.1  Laboratory Cleanup of Sample  Containers

    One of  the best containers for soil is  the glass canning  jar
fitted with Teflon or aluminum foil liners  placed between the  lid
and  the  top of  the jar.  These  items  are  cleaned in  the
laboratory  prior to taking  them  into the field.  All containers,
liners  and small  tools  should  be  washed with an  appropriate
laboratory detergent, rinsed  in  tap water, rinsed in distilled
water  and dried in an  oven.    They  are  then rinsed  in
spectrographic grade  solvents  if  the containers are to be used
for organic chemical analysis.   Those  containers  used  for
volatile organics analysis must be baked in a convection oven at
105  C in order to drive  off  the rinse solvents.

    The Teflon or aluminum foil used for  the lid liners is
treated in  the same fashion as the jars.   These  liners must  not
be backed with paper or adhesive.

7.8.2 Field  Decontamination

    Sample  collection  tools are  cleaned  according to  the
following procedure.

           •    Washed  and scrubbed with tap water
               using a pressure hose or pressurized
               stainless  steel, fruit tree sprayer.

           •    Check for  adhered organics with a
               clean laboratory tissue.

           •    If  organics are present, rinse with
               the waste  solvents from below.
               Discard contaminated solvent by
               pouring into a waste container for
               later disposal.

           •    Air dry the equipment.

           •    Double  rinse with deionized,
               distilled  water.

           •    Where organic pollutants are of
               concern, rinse with spectroqraphic
               grade acetone saving the solvent for
               use in  step 3 above.

           •    Rinse twice in spectrographic grade
               methylene  chloride or hexane, saving
               the solvent for use in step 3.

           •    Air dry the equipment.

           •    Package in plastic bags and/or pre-
               cleaned aluminum foil.

    The distilled  water and solvents are flowed over the surfaces
of all  the  tools, bowls  etc.  The solvent should be collected  in
some container  for disposal.  One technique that has proven  to  be
quite effective is to  use a large "glass or stainless steel funnel
as the collector below the tools during flushing.  The waste  then
flows  into  liter  bottles for  later  disposal (use the empty
solvent bottles  for  this.   A  mixing  bowl  can be  used  as  a
collection  vessel.   It is  then the last item cleaned in the
sequence of operations.

    The solvents  used are  not readily  available.  Planning  is
necessary to insure an adequate supply.  The waste rinse solvent
can be  used  to remove organics stuck to the tools.  The acetone
is used as a  drying agent prior  to use of the methylene chloride
or hexane.


    Steam cleaning might prove  to  be useful in some  cases but
extreme  care  must be taken to insure public  and worker safety by
collecting the wastes.  Steam alone  will not  provide assurance of
decontamination.  The solvents will  still have to be used.
7.9 Quality Assurance

    Quality  assurance  in EPA is usually  handled by someone other
than the sampling  team.  The field team leader  is responsible for
insuring  that the quality assurance program is carried  out
correctly,  however.  The team will be required to take duplicate
samples at prescribed intervals  and  will be required to submit
field blanks of all materials used.   It would be desirable to
prepare a  bulk  soil  for  use as a  field  blank for the  soil
samples.  This will have to be handled very  carefully because of
the difficulty in finding "clean"  soil for use as the  blank.
Distilled water can be used in lieu of a soil blank.  Additional
samples such as equipment swipes,  rinse water and solvents should
be taken  on a regular basis to  verify the  quality of the data
obtained  from the samples.   Procedures for  handling quality
assurance have been outlined in an interim guideline prepared by
the EPA Office of  Monitoring Systems and Quality Assurance of the
Office of Research and Development (OMSQA, 1980).
7.10 Safety

    Toxic chemicals  create a hazard for  the soil sampling team.
The team often  is operating above plumes containing mixtures of
highly toxic  chemicals.  The drillers and excavators are  in an
especially hazardous position.  An industrial  safety specialist
should be consulted prior to undertaking  a  study of these highly
contaminated  areas.  Physical examinations should be given to the
crew on a regular basis unless the sampling  team operates only on
rare occasions  in which case they  should  have physicals  before
and after the sampling effort.

    Many of  the field  team members  will not want to follow the
procedures outlined by the safety  officer.  This should not be
tolerated. This problem seems  to  be especially acute  with  the
drilling crews.  Every effort should be made to  provide  the teams
with adequate  training on the use of all  safety equipment and
recovery procedures prior to going into the  field.

                        SECTION 8

                      DATA ANALYSIS
     The final  step  in  any sampling study is the analysis and
interpretation of the data that  has  been collected.  It  is not
necessary for  the field scientist to  conduct the data  analysis,
but his input is necessary if any interpretation  of the data is
to be  made.  Impressions and observations obtained during  on site
activities  are needed to adequately  determine the actual  behavior
of the  pollutant.

     The person doing  the data analysis must keep in mind the
purpose for which the samples were collected.  These purposes can
usually be  grouped into one of the following categories.

         o     Estimate the level and variability of
                a pollutant in a geographic area.

         o     Determine if the pollution measured is
                above some standard  or is higher than
                the ambient levels found in the control

         o     Define the areal extent  and depth of
                the pollution and map the pattern
                of the distribution.

     There are  statistical tests available for handling data
collected by  each  method  discussed  in  Section 6.   Prior to
attempting to  use any  of the methods, a statistician  versed in
sampling design  should be consulted  to assure that  the
appropriate design is  being  used.  An assumption has  been made
that this was done at the beginning  and  is not being done  at the
end of  the  study.

8.1 Analysis of Data From  a  Simple Random Design
    The simplest  analysis of any of the designs is that  for  the
simple random analysis.  This  analysis can be  done easily on a
desk calculator if the  number of points is not  too great.  The
first  three  parameters that should be calculated are  the mean,
the variance  and the confidence  interval.   Where the results  are
to be compared to  other areas a number of tests are likely to be
used.  These  are discussed below.
    8.1.1 Basic  Parameters
    The  mean  (Eq,
confidence interval
 8.1.1), variance  (Eq. 8.1.2)  and  the
(Eq.  8.1.3)  are  calculated  by the  following
                       y =  2 y,/n
                           1=1 1
                              - 2
               V(y) =   2(y. - y)Vn(n-l)
              where     y. = ith observation
                        n = number of samples
                        y = mean of the samples
                      V(y)= variance of the mean
                           y ±
              where     L = confidence interval
                       ta= t-statistic for a two-tailed  t-test
                           at the a significance level  for
                           (n-1) degrees of freedom.
                       a = significance level
                    V (y) = variance of the mean

     8.1.2  Use of t-Test
     The data  for a  control population  and the  data  for the
contaminated areas can be compared statistically  using  either
the  analysis  of  variance  test or the Studentized  t-test.  The
control population often has  less  samples than the polluted  area
thus  some  adaptation will  have to  be made  in the data to
compensate for  the inequality in the number of samples in the two
treatments.    The t-test uses  equation  8.1.4  (Li,  1959) to
determine  if   the  two sets  of  samples  are different.   This
equation assumes homogeneity of variances which is  most often the
case in soils work.
t  =
(l/n1 +
      T  (
 t  =

 y  =
 n  =
                            calculated t-value

                            mean for sample set x

                            pooled variance calculated

                            by formula 8.1.5

                            number of samples in x
                                    - 2)
     The two data sets are considered to be from the same
population  (i.e., they are equal)  if the calculated t-value  (tc)
falls outside of the critical region (i.e., it falls within  the
range  -ta< tc
    8.1.3 Analysis of Variance of  Simple Random Design

    If the analysis of variance  (ANOVA) is used to determine the
difference  between the two  sets  of sample data, the  following
table can be used  to do the calculations for the ANOVA.  The term
treatment is a term used by statisticians when  handling  different
data sets.  This  should be kept in mind when reading  the sections
that follow.  One treatment  is  the  data from  the polluted area
and the second is  the  data from the control area.

	Table 8.1.1 Analysis of Variance for Simple Random Design

 Source of Variation   freedom*     Mean s
    Occasionally  a  study will be conducted  where no  control
exists.   This  is not  a  recommended practice,  but  there are
situations  where there  is  no  alternative.  The analysis in  this
restricted  case  is limited simply  to  the mean and the variance of
the data.
8.2 Data Analysis  for Stratified Random  Design

    The origin of the stratified random design is similar to the
simple random  design with  the  exception  that there is
stratification of  the  study area into subareas.  The  following
sections provide the procedures  for the analyses of the  data  that
can be conducted with this design.
    8.2.1 Basic Parameters  for the Stratified Random Design

    The  calculation  of the  mean and  the variance  for  the
stratified  random design can take two  forms.  Only one of the
forms will be  presented here.  Petersen and Calvin (1965) note
that in  cases  where the variance is  common between  two strata and
proportional allocation is used to assign samples to each strata
the calculations  for  the mean and the variance are simplified.
As was mentioned earlier, proportional  allocation is common  in
soils work because the variance tends to be the same over strata
that  are in close geographic proximity.   Petersen and Calvin
(1965) and Cochran  (1965)  can be consulted for the  other approach
to calculating these parameters.

    The  mean  is calculated by use of  equation  8.2.1 and the
variance by  use of 8.2.2.

                              y =  (  X y./n)
                                   i=l 1                (8.2.1)
                          V(y)  -  s2 /n                   (8.2.2)
           where     y = mean of  all strata

                 V(y) = variance of the mean y

                    n = total number of observations y.
                   2                                 i
                  s   = pooled variance (see equation 8.1.5)


    8.2.2 Analysis  of  Variance for Stratified  Random Design

    The analysis of  variance for the stratified random design  is
similar  to  that  for the simple random design.   Table  8.2.1
presents the  ANOVA table for handling  the data from a soil
sampling study  where this design has  been used.

 Table 8.2.1 Analysis of Variance for Stratified Random Design
Source of Variation

Within strata
T /n = Sum of
Degree of
the total of
Mean Squares*
(2y2-( T2/n))/(2n-h)
each stratum squared and
    divided  by  the number of samples  in the stratum.
    G /£n  = The square  of the sum of all  observations

    divided  by  the total number  of  observations.
    y   = The sum of the square  of  each observation

    h  = The number of strata.
    The similarity between Table 8.1.1 and 8.2.1 can be  explained
by the  fact  that the simple random experiment with a control is
nothing more  than a stratified  random experiment with  2  strata.
The only difference is in the identifiers for  treatment (k) and
strata (h) .

    Tests and interpretation of  the results of the ANOVA would be
the same as  that presented for  the simple random design.   If the
strata are different,  it may not be  possible to determine which
stratum is causing  the ANOVA to show the differerence if more
than two strata  are  used.  This can be determined,  however, by
using  tests  such as  the single degree of  freedom,  regression
analysis or  by calculating  the least significant  difference
(LSD).  This  latter test can be  used to determine if  there is a
difference  between  the stratum means (y) or  the differences


between stratum  totals (Th). 'Inequality  8.2.3  can be  used for
testing the differences between two  stratum means.
         where  Y h = mean for the  h   stratum

                          ta = t value from statistical

                               tables at the ( Jn-h)

                               degree of freedom and

                               the a significance level

                         Jn = total number of  observations

                         s   = Pooled variance  which  is
                               also the within strata mean

                               square from Table 8.2.1

The absolute, |y - y |, is compared to the term on the  right side
of the  inequality;  if larger, the difference  is significant.
Each pair of  strata means are compared in this fashion..
8.3 Data Analysis for Systematic Sampling  Designs

     This design  provides  uniformly spaced data for  the entire
study area.  The uniform distribution allows reliable  maps  to be
drawn, trend analysis to be conducted  and  facilitates kriging
calculations.   The  literature  (Petersen  and Calvin,  1965;
Cochran, 1946; Yates,  1948)  indicates  that  the systematic
approaches  provide an increased precision over  the two random
designs under  most conditions.   As was  mentioned earlier, cyclic
and periodic phenomena can create problems in data analysis.  The
systematic  design is in reality a  stratified  design with one
observation per stratum.   The lack of multiple samples  taken from
each of these stratum  precludes  the  use of analysis of variance
because there are  no degrees of  freedom  for use  with the within
stratum mean square.

    A  number  of tests have  been devised  for extracting
statistical data  from these  designs.   One method  analyzes the
differences between observations made at adjacent nodes on the
grid.  Either 4, 6, or 8 differences  are generated for  each  point
on the  grid.   The number depends upon the design of the grid and
the  location of  the  particular pair  of points.  The set of
differences become the source of data for calculating a within


stratum mean  square.   The analysis would  be  the  same as that
shown in Table 8.2.1.

    Regression  techniques  can also  be used.   Regression
effectively  removes the effects of  trends over the area  and still
provides  information about the concentration differences  and the
variance.  These  tests do not allow the  researcher to identify
the spatial  relationship of the data points, however.

    When  systematic designs  are used, an attempt should  be made
to evaluate  the effects of cyclic patterns that may  be  present in
the data.  Autocorrelation analysis can be  used to  identify if
these patterns are present or  not.  Frequently  examination of a
plot of the  residuals from a regression analysis will  also reveal
cyclic patterns in  the data.  If these  patterns exist, some
effort should be made to remove  their effects from the data
before analysis is done.
    8.3.1 Kriging Analysis  of Systematic Data

    The technique called  kriging was first developed  by D.G.
Krige (1966)  as a means for estimating gold ore reserves  in South
Africa.  The  technique develped  by Krige was based upon the use
of moving averages in handling systematic data.   His  techniques
were further  developed by G. Matheron  (1971) at the National
School of Mines  in  Paris  and have since been expanded into a
whole body of knowledge called qeostatistics.  Matheron called
the method  kriging  in  honor of D. G. Krige.  This technique has
been used in  European and  South African mining  fields  for some
time but it  has  only recently begun to be  used in pollution
control work.

    A number of soil scientists  have explored its use and found
that in cases where  a mapping  effort  involves  significant
research, economic or political decisions or any kind of  analysis
where spatial distribution is an important  part of a decision
making process,  the technique provides what is  called  the best
linear  estimation of the  distribution  of a particula-r  soil or
rock component.  The estimate is unique in  that it provides a
minimum estimation  variance for  the available data set  and also
allows  the researcher not only to develop an isopleth  map but an
error  map as well.   The  technique has  advantages over other
methods of analyzing spatial data  in that trends normally seen in
environmental data  (especially pollution data)  can  be removed
from the analysis.   (The term trend applies to those cases where
there is a change in some property along one or more axes of the
study  area.   Pollution from a leaking landfill would show such a
trend.   The  further away from the  landfill the lower would be the
concentration thus a trend  would exist.)


   Nielsen  and his associates (Nielsen et al., 1973;  Warrick et
al.r 1977;  and  Vieira et al., 1981) have used  the method to
study the spatial variability of the soil system in an attempt to
develop reliable predictions of  water movement through the soil.
Campbell (1978) used the technique  in an attempt to delineate the
boundaries between  soil types.  Burgess and Webster  (1980 a/ b)
and Webster and Burgess  (1980) present an excellent review of the
technique.  Olea  (1975)  has  produced  a  number of  monographs for
the Kansas  Geological Survey that provide detailed  information on
the technique.  Associates of Dr. Olea have produced  a  computer
package that can  be  used to conduct kriging  and  plot  the
resulting maps.  This program ,called Surface II, is avialable at
a number of computer centers around the U.S.

    In those cases where  kriging has  been  used in pollution
control  work, it has  met with considerable  favor.    Madeline
Barnes (1978, 1980)  has used this technique in  a number  of major
operations where radioactive materials were  being removed  from
the environment.   The most notable   example  was the work done on
the  Enewetak Atoll  in  the  Pacific Ocean.   Nielsen and  his
associates (Nielsen  ,  et.  al. ,  1973; Vieira et. al., 1981)  have
used the techniques for  studying the  variability  of a  number of
soil water  properties.

    Kriging has an advantage over other statistical tools  in  that
it provides  not only  the  means of evaluating the spatial
variability of the soil property but it also  provides an estimate
of  the variance at  each point on the map surface.   The main
disadvantage of  kriging appears  to be the  complexity  of  the
mathematics involved.  Although  kriqing may be difficult  to  use
under  some conditions, it often makes the most  use of limited
available data and thus  provides the  best  answer  for the amount
of data available.

    The  statistical  basis  for  kriging  is  the theory of
regionalized variables.  Kriging  attempts  not only to estimate
the  values of  the  regionalized  variable  (the  spatially
distributed variable)  but also to assess  the probable  error
associated with  the  estimates.  A variable is considered to be
regionalized  if "it  varies from one place  to another with
apparent continuity,  but cannot be  represented by an ordinary,
workable function" (Davis, 1973).  The theory is not a new branch
of statistics but  in  reality is  an extension of the part of
conventional statistics called time series  analysis.  It  is  used
primarily because "conventional statistical  approaches  are
inadequate for  the  description of any variable  from  a natural
phenomenon  which  has  a spatial distribution"  (Olea, 1975)  — a
common occurrence with soil systems.  The intrinsic theory behind
kriging is  explained fully by Olea  (1975) who reviews the current
status of the method and by Mather on  (1969, 1971)  who developed
much of the theory.

    Figure 8.3.1 presents an overview of  the procedure for usinq
kriging.   The  process of the data  flow begins with the selection
of sampling sites even though kriging is not a sampling method.
The  first step in the  use of  kriging  is  to calculate  the
semivariance  (1/2  of the variance)  by  use  of the  following
                                   li'                   (8.3.1)

         where     n = the number of pairs of points on a line

                 y..  = the semivariance

                  y.= the value at point x.

              y.. + ..= the value at a point  j distance from

                        x. along a line passing through x.
    The V(h)  values are plotted against  the spacing h along  the
grid line to  give the variogram.   There  are a number of forms of
the variogram.  Those shown in Figure 8.3.2 are found in a number
of the references  listed in  this  report.   A  number of  the
patterns  are reported by Barnes  (1978,1980).   Figure 8.3.2  (a)
and  (b) are the  two classic  forms of the  varioqram.  All of the
other examples are variants of these two  forms.  Figure 8.3.2 (a)
shows the  range of influence which is the distance over which the
samples are  correlated.  When  the curve  fails to pass through the
origin  as  in (c)  or  (d) , a "nugget" effect  is seen.  This results
from sample  grid  spacing  that is too wide to pick up the detail
of the  system.   (The term originated from the  gold fields where
discrete nuggets of gold were found within blocks of ore.)   The
limit of  the curve in  Figures 8.3.2 (a,c,f)  is  called the  sill
and represents the variance of the entire system (i.e.  there is
no longer  any  correlation  or  dependence of one sample  upon
another).  Figure 8.3.2 (e) shows  pure  nugget effect where all
samples  are independent  of each other.  Classical random
statistics  should be used in  such situations.  Olea (1975)  notes
that there is  an art to  fitting the correct model to  the
variogram.   A number of the models can be tried to find  the  one
that best  fits the type of data being evaluated.

    A second important property of regionalized variables is  that
of drift.  Drift  is the trend  of the data over the geometric  area
of the  investigation.  If Z (jc)  is a regionalized variable and the
drift  is m("x) then  the residual y("x")  is given by equation 8.3.2
(Olea,  1975).

                     LAY OUT SAMPLING LOCATIONS I
                          COLLECT SAMPLES
                                                 ANALYZE SAMPLES
                      COMPUTE  KRIGING WEIGHTS
                              PLOT MAP
                       E MORE SAMPLES NEEDED
                          I WRITE REPORT |
Figure 8.3.1  Flow sheet for kriging analysis

Figure 8.3.2  Examples of semi-variograms developed during  kriging.


                 y(~x) =  Z("x)  - m(T)                     (8.3.2)

A variogram of  the  residuals is plotted  in  a manner similar  to
Figure 8.3.2.   This represents the  variogram with  the  drift
removed  from  the data.   The  object of  this exercise  is  to
determine the true variance of  the data.  Where drift is a major
factor in the data,  it may be  necessary  to  go to some form  of
multivariate analysis rather than use  kriging.

    Calculation of  the semivariance of  the grid data for several
directions will allow  the  researcher to determine  if  drift  is
present  in the data and  also allow other  anisotropy to  be
identified.  Anisotropy can often be  removed from the data  by
transposition of the data.

    Kriging also can be used with data that was not obtained from
a systematic grid pattern  but  the mathematical manipulations  of
the data  increase  considerably.  The  problem with data not
obtained  on some  linear pattern is that  the variogram cannot  be
calculated.  If additional information  will allow an estimate  to
be made of the  variogram, it is possible to krige missing points
and thus  develop  a  grid for developing isopleths.  This type  of
situation is where the method is really  an improvement over other
methods of data analysis.  The  areas  not covered by samples are
partially covered by samples lying adjacent to  the vacant areas.
The variance of the points kriged provides  an estimate of the
precision of any data obtained in this way.

   One of the methods that has been used  for testing kriging has
been to krige a set of points where data is  known.  Each actual
data point is  removed, a point is kriged then a comparison made
between the actual  and  the  kriged points.  Chi-squares  can  be
used to test the two distributions to determine the fit of the
data.  This comparison is also used  to calculate the error term
for the kriged  values.

    This  technique is relatively new  when compared to classical
statistics; therefore, the methods have  not  been refined to the
same degree as those  of random sampling theory or analysis  of
variance.   The details of  this method  are  too extensive for
inclusion in this paper.  The reader is  referred to Olea  (1975) ,
Barnes (1980), Campbell (1978), Burgess  and Webster (1980 a,b) ,
Webster and Burgess  (1980) ,  and Rendu  (1978)  for the details  of
the method.  The Kansas Geological Survey  computer programs can
be obtained for a fee at a number of computer centers in  the U.S.
The names of those closest to the researcher can be obtained from
the Survey.

Barnes, M. G.  1978.  Statistical Design and Analysis in the
     Cleanup of Environmental Radionuclide Contamination.
     Unpublished M. S. Thesis.  University of Nevada, Las Vegas,
     Nevada.  52 pp.

Barnes, M. G.  1980.  The Use of Kriging for Estimating the
     Spatial Distribution of Radionuclides and Other Spatial
     Phenomena.  In Trans-Stat No. 13.  Battelle Memorial
     Institute-Pacific Northwest Laboratory.  Richland,
     Washington.  22 pp.

Beckett, P. H. T., and R. Webster.  1971.  Soil Variability:  A
     Review.  Soils and Fertilizers.  34:1-15.

Burgess, T. M. and R. Webster.  1980a.  Optimal Interpolation and
     Isarithmic Mapping of Soil Properties.  I. The
     Semi-variogram and Punctual Kriging.  The J. of Soil Science.
     31(2): 315-332.

Burgess, T. M., and R. Webster.  1980b.  Optimal Interpolation
     and Isarithmic Mapping of Soil Properties.  II. Block
     Kriging.  The J. of Soil Science.  31(2):333-342.

Campbell, J. B.  1977.  Variation of Selected Properties Across a
     Soil Boundary.  Soil Science Society of America J.

Campbell, J. B.  1978.  Spatial Variation of Sand Content and pH
     Within Single Contiguous Delineations of Two Soil Mapping
     Units.  Soil Science Society of America J. 42(3):460-464.

Campbell, J. B.  1979.  Spatial Variability of Soils.  Annals of
     the Association of American Geographers.  69(4):544-556.

Campbell, J. B.  1981.  Spatial Correlation Effects  Upon Accuracy
     of Supervised Classification of Land Cover.  Photogrammetic
     Engineering and Remote Sensing.  47(3):355-363.

Chapman, H. D., and P. F. Pratt.  1961.  Methods of  Analysis of
     Soils, Plants and Waters.  University of California,
     Riverside, California.   309 pp.

Cline, M. G.   1944.  Principals of Soil  Sampling.  Soil Science.

Cochran, W. G.   1946.  Relative Accuracy of  Systematic and
     Stratified Random Samples for a Certain Class of Population.
     The Annals of Mathmematical Statistics.  17 (2) : 164-177.

Cochran, W. G.   1965.  Sampling  Techniques.   John Wiley.  New
     York,  New  York.   413 pp.

Davis, J. C.   1973.   Statistics and Data Analysis  in Geoloqy.
     John Wiley.  New York, New York.   550 pp.

Harrison, A. F.  1979. Variation of Pour  Phosphorus Properties  in
     Woodland Soils.  Soil Biology and  Biochemistry.   11:393-403.

Hindin, E., D.  S. May, and G. H. Dunston.  1966.  Distribution  of
     Insecticide  Sprayed by  Airplane on  An  Irrigated Corn Plot.
     Chapt.  11  in Organic Pesticides in the  Environment.  A. A.
     Rosen  and H. F.  Kraybill  (eds) .   Advances in Chemistry
     Series #60.  American Chemical Society.   Washington, D.  C.
     pp.  132-145.

Krige, D. G.   1966.  Two-dimensional Weighted  Moving Average
     Trend  Surfaces  for Ore Evaluation.   J.  of South African
     Institution  of Mining and Metallurgy.   66:13-38.

Li, J. C. R.   1959.   Introduction to  Statistical Inference.
     Edwards Brothers.  Ann Arbor, Michigan.  553 pp.

Matheron, G. 1969.  Le Krigeage Universal: Les Cahiers du Centre
     de Morphologic Mathmatique de Fontainebleau.  Fascicule 1.
     1'Ecole Nationale Superieure des Mines de Paris.   Paris.   83

Matheron, G. 1971.  The Theory of Regionalized Variables and its
     Applications.   Les  Cahiers  du Centre  de Morphologic
     Mathmatique de  Fontainbeleau, Fascicule 5.   1'Ecole
     Nationale  Superieure des Mines  de Paris.  Paris.   211 pp.

Mathur, S.  P.,  and R. B. Sanderson.   1978.  Relationships Between
     Copper Contents, Rates of Soil  Respiration  and  Phosphatase
     Activities  of Some Histosols  in an Area of Southwestern
     Quebec in the Summer  and the Fall.   Canadian J. of Soil
     Science.   58(5):125-134.

Mausbach, J. J., B. R. Brasher,  R. D. Yeck, and W. D.  Nettleton.
     1980.   Variability of Measured  Properties in  Morphologically
     Matched  Pedons.  Soil Science Society  of  America  J.

Nielsen, D. R.,  J. W. Biggfar and K. T. Erh.  1973.  Spatial
     Variability of Field-measured Soil Water Properties.
     Hilgardia.   42(7):215-260.

Office of Monitoring Systems and Quality Assurance.  1980.
     Interim Guidelines and Specifications for Preparing Quality
     Assurance Project Plans.  QAMS-005/80.  U. S. Environmental
     Protection Agency.   Washington, D. C.
Office of Occupational Safety and Health.  1979.
     for Hazardous Waste Site Investigations.  U.
     Protection Agency.  Washington, D. C.
Safety Manual
S. Environmental
Office of Pesticides Programs.  1976.  Sample Collection Manual:
     Guidelines for Collecting Field Samples.  U. S. Environmental
     Protection Agency.  Washington, D. C.  39 pp.

Olea, R. A.  1975.  Optimum Mapping Technique Using Regionalized
     Variable Theory.  Kansas Geological Survey.  Lawrence,
     Kansas.  137 pp.

Petersen, R. G., and L. D. Calvin.  1965.  Sampling.  Chapt. 5 in
     Methods of Soil Analysis.  C. A. Black  (ed.).  American
     Society of Agronomy.  Madison, Wisconsin.  pp. 54-72.
Cuenouille, M.H. 1949.  Problems in Plane Sampling.
     of Mathematical Statistics.  20:355-375.
   The Annals
Rao, P. V., P. S. C. Rao, J. M. Davidson, and L. C. Hammond. 1979.
     Use of Goodness-of-fit Tests for Characterizing the Spatial
     Variability of Soil Properties.  Soil Science Society of
     America J.  43 (2):274-278.

Rendu, J. M.  1978.  An Introduction to Geostatistical Methods of
     Mineral Evaluation.  South African Institute of Mining and
     Metallurgy.  Johannesburg, South Africa.  84 pp.

Richards, L. A.  (ed.).  1969.  Diagnosis and Improvement of
     Saline and Alkali Soils.  U. S. Salinity Laboratory.  Riverside,
     California.  Agriculture Handbook No. 60.  U. S. Department of
     Agriculture.  Washington, D. C. 160 pp.

Soil Science Society of America.  1965.  Glossary of Soil Science
     Terms.  Soil Science Society of America Proceedings.  29(3):

Soil Survey Staff.   1951.  Soil Survey Manual.  Agriculture Handbook
     No. 18.  Soil Conservation Service.  U. S. Department of Agri-
     culture.  Washington, D.C. 503 pp.

Vieira,S. R., D. R. Nielsen and J. W. Biggar.  1981.  Spatial
     Variability of Field-measured Infiltration Rates.  Soil Science
     Society of America J.   (in-press).

Warrick, A. W., G. J. Mullen,  D.  R.  Nielsen.  1977.  Scaling
     FieId-measured Soil  Hydraulic Properties Using Similar Media
     Concept.  Water Resources Research.   13 (2) : 355-362 .

Webster, R.  and T. M.  Burgess.   1980.  Optimal  Interpolation and
     Isarithmic Mapping of Soil Properties III.  Changing Drift
     and Universal  Kriging.   The  J. of Soil  Science.
     31(3) :505-524.

White,   G.  C.  and T. E.  Hakonson.   1979.  Statistical
     considerations and  Survey  of  Plutonium  Concentration
     Variability in Some  Terrestrial Ecosystem  Components.   J. of
     Environmental Quality.  8 (2):176-182.

Ya te s,  F.   1948.   Systematic  Sampling.   Philosophical
     Transactions of the Royal Society of London.   Series A.

                          APPENDIX A


                         SECTION  A-l

        This appendix is designed  to be a guide to assist  in  the
development  of a soil sampling  protocol.   Extensive discussions
with soil scientists in  the field  indicate  that it  is not
possible nor advisable  to develop a single  protocol  that will
attempt to meet all situations.   The material that follows  allows
the environmental  scientist to  progress through a  protocol
developmental process thus arriving at a protocol that will meet
his particular needs.   The four major types of study situations
addressed  in Section 4 are addressed here from the point of view
of developing a protocol for use in each type of a setting.

                          SECTION A-2

    Every field  of  research has a basic set of knowledge that the
worker must be able  to handle.  The follwing  types of  reference
materials  should be read before  any attempt is made to sample

    Be conversant with terminology in the following areas:

             Basic  soil science
             Sampling theory
             Statistical designs
             Environmental monitoring
             Quality assurance
             Basic  toxicology
             Basic  chemistry

    Read the following materials:

              Federal Register.  Vol. 144:69464.  December

              Interim Guidelines and Specifications  for
              Preparing  Quality Assurance  Project Plans
              (OMSQA, 1980) .

              Safety Manual  for  Hazardous Waste  Site
              Investigations (OOSH,  1979).

              The  three articles on  kriging written  by
              Burgess and Webster (1980  a,  b)  and
              Webster and Burgess (1980).

              The article by Beckett and R. Webster  (1971).

              The article by Mausbach et al.  (1980)

              The main body of this  report.

                          SECTION  A-3

    Any  protocol that will be developed  by the environmental
scientist will have  the  following  basic outline:

         1.  Introduction

         2.  Objective
              2.1 Goals  to  be  met
              2.2 Reliability  that can be placed on the results
              2.3 Precision of the estimates generated
              2.4 Resources to be  made available
              2.5 Schedule

         3.  Definition of  the  Magnitude of  the Problem
              3.1 Known  aereal extent of the contamination
              3.2 Known  vertical extent of  contamination
              3.3 Chemicals that have been  identified
              3.4 Known  concentrations
              3.5 Toxicity  of  chemicals
              3.6 Attitude  of  community toward problem and
                  problem  solvers.
              3.7 Identification of  type of pattern

         4.  Selection of Statistical Design
              4.1 Number of samples  needed  to meet reliability
              4.2 Distribution of  sample sites
              4.3 Frequency of sampling
              4.4 Quality assurance

         5.  Selection of a  Sampling  Method
              5.1 Type of pollution
              5.2 Depth  of  contamination
              5.3 Tools
              5.4 Determine how samples to  be collected

         6.  Data Analysis
              6.1 Basic  parameters
              6.2 Statistical  designs
              6.3 Regression
              6.4 Spatial distribution

    A suggested way  to  use this section is to make  up  a series of
sheets  of  paper with  headings similar to  those in the above
outline.  When the questions are asked and answered make  note of
the  answers  on the  pieces of  paper.   When you are through with
the exercise  you should  have a good  start on writing your own
3.1 Background Information.

    Read section  5  (pp. 14-19) of the main body of  this  report;
then,  assemble  all  of  the following kinds of  information  that are

          1.  History of the particular study area;  its
             uses and  misuses.
          2.  Any  chemicals that have been placed on  the
          3.  The  source of  the pollution  that you  are
             attempting to identify.
          4.  Ownership of the study area both past and
          5.  Any analytical  information on samples
             collected in the area.
          6.  The  results of all investigative reports.
          7.  All  geological and  soils information on
             the  study area or the surrounding area.
          8.  All  information on the  toxicology of  the
             pollutants studied.
          9.  The  political and community situation.
         10.  All  existing protocols pertinent to the
             sampling  program.
         11.  Copies of USGS quad maps of the  area.
         12.  Copies of all archived aerial photography
             of the area.
         13.  Copies of all current aerial photography.
         14.  Copies of all documentary photography  of
             the  site.
         15.  Copies of all reports on the site.

    In addition to  the above information, visit  the study area
and talk to members of the community that are knowledgeable about
the locality  and  also about  the specific  area of the study.
Attempt to determine likely control areas at  this  time.   Remember
you are an investigator at this time and are attempting  to learn
as much about the study area  as  you can in  order  to  make your
sampling  study not only meet the objectives but  also to gain as
much insight  into the  pollution situation as  is possible.

    3.1.1  Questions to  Answer.
    Attempt to answer the following questions prior to the study.

        1. What is the pollution source?
        2. What chemicals are in that source?
        3. When was it placed there?
        4. How was it placed there?
        5. Who placed it there?
        6. Why was it placed there?
        7. What kind of containers was it in?
        8. What levels have been found in the
        9. How toxic is it and what are the known
       10. Has anyone locally been hurt by the
           pollution?  (This is not an epidemiological
           study but is to let you know what the
           reactions of the community may be.)
       11. How far has the pollution gone?
       12. What data is available on its migration?
       13. Who determined that migration had occurred?
       14. Are the data on concentrations and on
           migration reliable?
       15. What other environmental studies have been
           conducted in the area?
       16. Is the data available for examination?
       17. Will the researchers in the area cooperate?
       18. Are there any court actions pending?
       19. Are there any administrative actions pending?
       20. Is there a potential for litigation in the case?
       21. What is the public's awareness of the problem?
       22. Are they frightened or angry?
       23. Who are the spokesmen for the local population?
3.2 Develop an Objective Statement for the Study.
A. Has an objective statement been issued for the study?
              YES - Record it and go to 3.3
               NO - Review Section 3 of main report and
                    then go to 3.2.1

    3.2.1 What  is  this  study attempting to accomplish?

    The goals that  are  needed are  explicit, clear statements of
what is to be  accomplished by the study.  It may be nothing more
than a question  such as "How much  of  the area around the  spill is
contaminated?".  It  may,  on the other hand, go  to considerable
length to determine the levels of contamination at  various
locations within  the study area.

    Spell out  a  definite set of questions that you hope to answer
with the study.   You  should  not  be hesitant to  ask for a more
definitive goal  if  it  is not clear what is  being asked..  There
are often cases  where the person ordering the study does  not know
what is really possible and what is  really needed.  That  is where
the scientist  must assist in setting  the objectives of the study.

    Decide upon your  objectives and write them down.   Get an
approval on them  so that you are sure that you  understand what is
being asked and  to insure  that  your results will meet the needs
envisioned by  the administrative order.

    Write down your final objective  under the appropriate part of
the outline then  go to 3.2.2.
    3.2.2 How close must  the estimates be to  the real  Bean
    Scientists often measure  the precision of the  methods that
they use in  a  laboratory but they seldom attempt to  do  so  in the
field.  This  is  because of  the difficulty  in  defining  the
variation to  the point that they can control it.   A  level of
precision should be  delineated for the study.  This is usually
expressed as a percentage of the  mean.

    A second way  of evaluating the precision  of  the data is to
identify the smallest difference between  two  samples  that you
would  like to  be able  to detect.  If you are  attempting to
delineate variations in the  pollution in a large area,  you would
probably want a  level that was quite  small  because of  the
subtilties  of the deposition  pattern.  On the other hand, in a
situation  where you are  attempting  to determine  the  area
contaminated by  a major spill, you may not need  to be able to
detect  small differences in order  to make the determination that
one area is  contaminated and another next to it  is not.

    If a number  cannot be decided upon a twenty percent  value may
not be too far out of line.   You  are asking  that  your sampling
determine a value  that is within twenty percent of  the  true mean.
This would be totally unacceptable for a laboratory  method but  it
reflects the true  field situation.

    Record your  decision and go to 3.2.3.
    3.2.3  How  reliable must the  answers be?
    The question of  reliability and precision may seem to be the
same.  What you are  attempting to determine is not how close  your
answers  are but what is  the probability that the answer you get
is the correct one.

    Read Section 6.1 of the main  report before deciding  your
answer to this question.   You  should also  read  the section on
simple random sampling  (6.2).  Statistical sampling requires  that
a known  confidence level  be given.  Three are often used  by the
scientific  community.  These are the 68%, 95%, and 99% confidence
levels or significance  levels.  Another  way to state this  is to
say  that the probability  is  0.32  (or about  1  in 3) that the
absolute statistical error exceeds one standard deviation  around
the true mean for the  68% significance  level; 0.05 (or  1  in 20)
for the 95% confidence  level; and .01 or  {1  in 100)  for  the 99%
confidence  level.

    For the results  to  be  absolute, a 99% confidence level  should
be used. When resources are limited or when reliability is  not of
paramount importance,  the  68% confidence level can often  be  used.
The important point is to  know  the confidence  level before the
study is conducted.

    When there is no basis  for  a  decision,  the  95% confidence
level is often used.  Record your answer and go to 3.2.4.
    3.2.4 What  resources are available for the  study?

    The answer  to this question may be developed by an iterative
process.  The answer  can  be a very  definite limitation if  it  is
known before the planning  is done but without it the planning  is
often  unrealistic.   You may not be able to answer this question.
This depends upon the administrative structure you operate under.
Your final  determination  may not  come until  the planning  is
complete and the schedule  is known.  Resources  include not only
finances but also personnel, laboratory capacity and equipment.


    Record your  answer  and go to 3.2.5.
    3.2.5.When  must the study be  finished?
    The schedule is  determined by the resources  and  vice versa.
You will have to set a  target date and attempt to  meet that date;
therefore, be realistic  in setting the date.

    Record the target date and go to 3.3.
3.3 Determine the Magnitude  of  the Problem.

    You need to know  the magnitude of the problem as  it is known
at this  time.   The information that you must have at  this point
covers not only the physical extent of the contamination but also
the concentration  range, the toxicity of the chemicals involved,
and the public relations aspects of the problem.  This is not a
major data gathering phase of  the study but it is a reflection of
the  needs  that may have to  be  met if information  is  totally
lacking.   Read Section 4 of the main report before you  answer the
following questions.

A.  Do you know the study category you will be working  in?
            YES -  Go to Question B.
             NO -  Go to 3.3.1.
B.   Which category will the study area come under?

         Large area with pollutant in the surface layers.
         Large area with pollutant at deeper layers.
         Local area with pollutant in surface layers.
         Local area with pollutant in a deep plume.

    The category that the study falls into  determines the
sampling  and statistical  designs that should  be  used.  After
making your decision go to  3.4.

    3.3.1   What  is the  known  areal extent of the
   You need to determine the magnitude of the area  to be covered.
This may be defined by the type  of  situation you are addressing.


For example  if  you are looking at worldwide  fallout from nuclear
testing you  are working at one  scale;  but,  if you are  working
with  a small  spill  site you  are  at  the opposite  end of the
spectrum.  There are two categories that you are attempting to

            o   Large areas that range from several square miles
                to a major portion of the  U.S.
            o   Local areas, such as  the area  around an accident
                site or a landfill site.

     Make  your  determination on  the  basis of available data and
your own knowledge of the problem.
    Record your  answer and go to 3.3.2.
    3.3.2 What  is  the vertical extent  of  the contamination?
    Information  on  this part of the study  may  be more difficult
to answer than the  question in 3.3.1.  Examine drilling logs,
investigation reports and  information on the  behavior  of  the
pollutants in  the soil.  Those that are soluble  are more  likely
to have  moved both horizontally and vertically. Examination of
the groundwater flow patterns should tell where  the pollution may
have gone.  Your  designs will depend upon this  fact.

    Is the pollution a soluble, deeply penetrating chemical?
    Is the source located deep in the soil  profile?
    Is the chemical  migrating upward to the  surface some distance
      from the suspected source?
    Has the chemical been at the site for a  considerable period
      of time?

    If you answer yes  to  any of these questions, then place the
chemical in one of the two deeply penetrating categories.  Record
your answer and go to  3.3.3  through 3.3.7.
    3.3.3 What chemicals have been identified  in  the  study

    3.3.4 What are the concentrations?

    3.3.5 Are  the chemicals toxic?

  Are  they toxic at the levels seen?
 Have  there been any suspected  injuries  in the
study area?


    3.3.6 What is the attitude  of the community toward the

    3.3.7 Place  the study into  one of the  four classes of
studies listed in 3.3.B  and  go  to 3.4.
3.4 Selection of a Statistical  Design.

    Each category of study design  has an associated group of
statistical designs' that can  best be  used  to address the
situation.  This section will attempt to direct you to those that
have promise of working but the final decision should be  done in
conjunction with the statistician.

A.  Do  you know the design  that you will use on the study?
                   YES - Record the information and qo to 3.5.
                    NO - Go to 3.4.1.
    3.4.1 How many samples do you need?

    See Section 6.2.1 of  the  main report for answer.  After
determining the number of  samples go to 3.4.2.
    3.4.2 What is the distribution of  the  sample sites?

    At this point you  may  want  to delay the final decision on
which  statistical  design  you will use  until you talk to a
statistician.  Basically you are  being  asked to select between
the simple random design   (Section 6.2  of the main report) , the
stratified random design  (Section 6.3)  and the systematic design
(Section  6.4).  The  simple  random design locates the points at
any location on the study area.  The stratifie'd design does the
same  thing  but  it  places  a portion  in  each  stratum.  The
systematic covers the entire  area with  a  grid  or with a series of
line transects.

    Based upon the objectives of the study and the decisions made
in the paragraphs above determine the sample distribution pattern
that you will use.  If you are more  interested in a uniform
distribution  use a  grid design.   If  you are interested in a
totally  unbiased  sample  use  some  form of the simple random

    There are  a  number  of variants on each  of  the designs that
can be provided  by your statistician.  One  that may be used  is
what  is  called  a nested simple random design.  This is used when
simple random  designs are used to  locate  the sample site but the
location of  the  samples within that site are  fixed by geometry or
some  other  limit  to randomness.  This  is  the  case with  soils
where the location on the surface is randomly determined but  the
below surface  samples are fixed by the surface location.  This is
not a  problem for the  field  scientist  but it  is for  the
statistician if  this fact is not  taken into  consideration in the

    Record  the  information on the design chosen and include
information  on the number of replicates that  the laboratory wants
along with  the  number  of duplicates your statistician tells you
that he needs  for the data analysis in 3.6 below.  Go to 3.4.3.
    3.4.3 What  is  the frequency of sampling?

    The frequency  of  sampling depends  upon the nature of  the
study.  Any study attempting to determine seasonal patterns  or
patterns  in  variables that are likely  to be associated  with the
seasons should  be  designed in such a manner that samples  are
collected at least once  each quarter.   Long term  trends  in
ambient soil  pollutant levels will only need  to be sampled on  an
annual basis; but,  it must be sampled at  the  same time each year.

    The more  detailed the information needed the more often the
soils should  be  sampled.  Those situations where the pollution is
changing rapidly will  require  more frequent sampling than those
situations where the pattern is stable  or only slowly changing.

    Select the frequency of sampling that meets the circumstances
of your study.  Record the choice made  and go to 3.5.
3.5 Select  a Sampling  Method.

    Read Section 7.0 of the main report.   From this select  a
sampling method  that meets your specific  need.  You must combine
the type of  pollution with  the depth of contamination to arrive
at the tools that you will use.  Once this  is  done you select the
method  by which the samples will be collected.  This  process
combines the tools with  the statistical design and the laboratory
procedures.  If the pollution is deep, use  one of the methods in
Section 7.3  dealing with underground  pollution.  If it is shallow
then  one of the  methods in  7.2 or 7.1 will be useful.   The
decision to  use compositing will  be  determined  by the data needs


of the statistician in order  to  answer the questions combined
with economics.   Use  Equations 6.2.1,  6.2.2  and  6.2.3 to assist
in making the decisions.  Go to 3.6.
3.6 Data Analysis.

    The data  analysis will be determined by the design  that was
chosen  in  3.5.   Section 8 of the main body gives  a discussion of
the approaches.  You need to determine  the  approach that best
fits your  needs.  Approach the problem from the point  of  view of
the user of  the  data.  The statistician will  probably use one of
the statistical computer program packages to analyze the data.

    The outline that is now  filled in should  provide you with a
fairly detailed set of information that you can incorporate into
the final  protocol.

                          APPENDIX B


                         SECTION  B-l

    The purpose of this  protocol is to provide an example of a
protocol for  use  in  sampling  surface  soils.   The procedures
outlined  here  are not intended to  be  the  final solution to  a soil
sampling protocol but  are only  a guide  for use  by  those
scientists undertaking to develop a  protocol for some particular
use.  The protocol  can  be used in cases where  the chemicals of
interest  are expected to be located  on the soil surface as would
be the case in an accident or chemical spill.

    The procedure used in this protocol  is simple and fast.  Ten
15 cm. long subsamples are to be  taken from the surface layer at
each sampling  station with an Oakfield type  tube sampler.  The
ten subsamples  will  be composited  and  sampled for analyses.  A
triangular grid  is used to insure complete coverage of the area.

                          SECTION B-2

                        SAMPLING DESIGN
    A triangular patterned  systematic sampling design  will be
used to collect  the  samples.  Ten subsamples will be collected at
each of  the  intersections of the grid lines.   At  ten percent of
the stations,  three  sets  of samples will  be taken for analysis.
The choice of ten percent was  purely  arbitrary  and has no
particular significance.  The number can  be better selected when
input from the analytical  laboratories is available.  The data
collected will be  analyzed  by kriging,  if  possible.  If it is not
possible to use  kriging,  the method of adjacent  differences  will
be used to determine  the  variation within  the grid.
2.1 Minimum  number of samples

    Calculate the minimum number  of samples to collect using
equation B-2.1.    In order to use  the equation you must have the
following pieces of information:

              •  Significance level you desire to use
              •  Coefficient of variation in %
              •  Percentage error you will allow
              •  t-tables

    The values are entered into the equation.  It is not possible
to obtain the t-value without knowing n.  The approach used is to
assume a value for n then look in the t-table for the t-statistic
at (n-1) degrees of freedom.  Calculate a new value for  n.  This
value is then  used  to  pick a  new  t-value.   The process is
repeated until the starting and ending values for n are the same.
Use the next  highest  integer if fractional values  of n result
from the calculations.

    2.1.1 The Equation

                  n =  (CV)2t2/p2                        (B-2.1)

Where n = the  number of samples;  CV =  coefficient of variation in
%; p =  the  percentage of error you  will  allow;  and  t  is  the
two-tailed  t-value  obtained from  t-tables for the significance
level at (n-1) degrees of freedom.

         If values  are  not known for the  variables  in  the
equation,  a  first approximation can  be used.  Use  95%
significance level, 65% coefficient of variation and 20 %  for  the
error you will allow in the numbers.  These latter two values  may
seem high.  They are intentionally chosen on the high side to
provide  a margin for  error.  The  65% CV is not out of line with
data from a  number of soils studies.   The  20% margin of error is
also not unreasonable for soils work.   Using  these values gives
an n of  43.  The closest triangular spacing to the n of 43  would
be 37  samples.   This   number is  determined  from Table B-2.1.
This number  would reduce the significance  level to approximately
93%.  This value was determined by inserting the n of 37 into
equation  B-2.1  and  solving for the  t value.  This calculated t
value  was then  compared with  the t-table  values in order to
determine the  level of significance.

If it is essential to have 95% confidence or better then the next
highest triangular  grid would be  chosen.   This grid yields 61
sample  points.   If  this number is used,  the significance  level
would be approximately 98%.
2.2 Grid Layout

    The triangular  grid consists of equilateral triangles laid
out to form a  hexagon.  The design  can  be elongated if desired
but the hexagon  is  the easiest to determine the number of samples
needed  to  meet  a particular area configuration.  The hexagon has
an equal number  of  line segments  on each  side.  This fact can be
used to assist in determining the number of samples in the array.
Figure B-2.1 shows  the grid and its  coordinates.   The number  of
sample points  for each grid size is  shown  in Table B-2.1.

                 •    Sample   point

Figure B-2.1. Triangular grid design showing coordinate numbering.

Table B-2.1.   Number of Sampling Points in Triangular Grids,
         Number  of  Points         Number of Samples
           on a  Side
              2                         7
              3                        19
              4                        37
              5                        61
              6                        91
    2.2.1 Selection of a Starting Point

    Select a starting point for locating the lower  left corner of
the hexagon by using either  the  UTM  coordinates  on  a map or by
using a grid overlay.   The procedures outlined  in  Section 6.2.2
of the main body of  the report can be used to locate the starting
point  for  the grid.   After  the  starting point is selected, the
triangular grid is oriented over the area to be  studied in such a
manner  that one of the nodes  is  superimposed  on the  starting
point selected above.   Samples will be  collected  at  each of the
nodes where the lines cross.
    2.2.2 Grid  Size
    The length of the  sides of the equilateral triangles  is  to be
determined by examination  of  the expected pollution  area.  This
may be  determined by a pilot  study or by examination of aerial
photographs and by site visits.   The grid should extend beyond
the boundaries of the  polluted area if it is  possible  to make a
determination of the approximate location of the boundaries be fore
the  sampling is done.   A set  of grids drawn on plastic  with
different map scales can greatly  facilitate the  use  of  this
design.  The location  of the  starting point determined  in  Section
2.2.1  determines where the  sampling points will  fall  but the
orientation and the size of the hexagon may have to be determined
by trial and error using the  plastic overlays.  Move  the  overlay
until the desired grid alignment is obtained keeping  in mind that
one of the nodes must  be located on the starting point.

     The size of  the  hexagon can be determined  by  an alternate
procedure.   First, estimate  the  area of the study  by placing a
square over the  known  or  suspected contamination.   This  area (A)
is entered  into  equation  B-2.2 to determine the  length (1) of the
sides of the hexagon formed by the triangular  grid.

                      A = 2.598 (I2)                       (B-2.2)
Use  of this  equation  will  allow the edges of  the  resulting
hexagon  to  extend beyond the  boundaries of the  contamination
because the  border of the hexagon  will fall outside of much of
the square used  to estimate the area of contamination.  Using the
size of grid calculated, prepare a plot plan  on a map of the area
using the starting point as one of the nodes  of the grid.

    The grid nodes are identified by a number-letter combination
as is shown  in Figure B-2.1.  The east-west rows will be lettered
and the diagonal rows will be numbered.
    2.2.3 Physical  Location of the  Grid  in the Field

    Locate the  starting point identified in  Section  2.2.1 on the
ground using  a map or  aerial photograph of  the  site.  Locate an
east-west line  through that point.  This line should correspond
to one of the lines  of the grid that you placed on  the map of the
site  in  Sections 2.2.1 and  2.2.2.   Measure east  along the line
the distance  (1)  calculated  with  equation B-2.2  or  scaled from
the map.  This  is the  first  sampling location.   Continue this
process  until  the appropriate number of points are located along
this line.  Mark  each  sample point with a stake.  Using a metal
tape measure  or  surveyor's chain, strike an arc from  each  of  the
points.  Another point is  located  at the  intersection  of  the
arcs.  This  point is  staked.  The process  is continued until the
entire hexagon has been staked out on the  ground.  The number of
sample points located  on each side  of the hexagon  is given in
Table B-2.1.  Photograph the plot upon completion of  staking.
2.3 Compositing of the Samples

    At each grid  node,  take ten individual 15 cm cores with a
standard Oakfield  tube sampler.  These cores are  to be placed in
a stainless steel  pan, then mixed with a stainless steel  scoop
until  the  soil  appears to be relatively homogeneous.  Take small
samples from each  quarter of  the pan.   Remix the  remaining soil.


Take a second  set  of  subcomposites adding  these  to the first
subcomposite.  Continue this process until  250 g of soil  is
obtained.   Dispose of any waste  at an appropriate disposal site.
2.4 Replicates

    At 10% of the sampling  points take triplicate  sets of cores
(i.e.  3  groups of 10 each);  composite  these as separate samples
— DO  NOT  MIX AS ONE COMPOSITE.  The same procedure  will  be used
for each  composite as was described in Section 2.3  above.  These
samples  will be used to obtain a measure of the variation within
each  grid.  In order to  insure uniform coverage with  the
replicates, the  hexagon  will be divided  into  six  segments
determined by running  a line from each corner.  This will give
six triangles from which  to take the triplicate samples.   Ten
percent of  the samples in each small triangle will  be randomly
selected for replication.   Fractional numbers will  be rounded to
the next higher number.
2.5 Controls  and  Background Samples

    Collect enough samples from an  uncontaminated  area to equal
20% of the  total  samples collected  in the sampling  grid.  These
samples will be used to establish  an environmental  baseline and
to test the limits of  the contamination measured in  the grid.
(This  sets  an analytical limit to determine  which of  the grid
samples are contaminated and which  are not) .
    2.5.1 Location of  Controls
    Locate  the control samples upwind from the site in  an area of
similar soil  types and  similar land use  to  the study  area.
Aerial photographs  available in the county SCS office can be used
as a starting point for identifying where the best control  sites
are likely  to be  found.   The candidate areas should  be visited
and an at tempt made to determine the history of the area.  You are
looking for  an area that has as many characteristics  in common
with the study area as is possible.  The ideal control  area would
be one  with no  source of pollution but  all soil and land use
characteristics the  same.  This  is seldom possible so the field
team  leader must  determine the  best  compromise for  the  area.
Where  time  permits,  a number of pilot study  samples could be
taken from  the candidate control areas.

    Care must  be  exercised  when taking these  samples to insure
that the owners and neighbors understand that the control  area  is
not believed to be contaminated;  on  the contrary you believe  that
it is not contaminated.  Let them know that  you  are collecting
the  samples for  a  baseline.  This precaution avoids a lot of
unnecessary anxiety in the community where a spill has occurred.
In  rural areas, the county  extension agent or  the  soil
conservationist can greatly assist  in finding  cooperative land
owners and in  reducing the fears  of  the local community.

                         SECTION B-3

    Sampling of shallow soils  is simple and  straightforward.   The
approach presented  here  is  designed to provide the researcher
with the  basic tools for collecting the samples.
3.1 Sampling  for Non-volatile Chemicals

    At each  sampling point  lay out  a  circle with a diameter  of
either 3 meters or  1/4 of the  side of  the small  triangle,
whichever is  smaller.   Beginning at  the northernmost point  on
this circle, take ten,  equally spaced,  15 cm soil cores around
the circle  using the  Oakfield tube sampler Model 22G.  Place
these cores  in the mixing pan and  follow  the procedure outlined
in Section  2.3.  If ten cores  do  not provide an adequate sample,
increase  the sampling density  around the circle.  The composited
samples are  to be placed in  precleaned, glass containers  fitted
with precleaned teflon or  aluminum foil lid liners.  Use the
procedures outlined  in Section 7.8 of the main body of  this
report for cleaning the glassware  and the tools used.

    When  rock  or large  roots  are  encountered,  move the sampler
several inches to one side or the  other.   Select a direction and
follow it during  the  sampling effort.   A new, decontaminated
sampling tube  is  to  be used  at each sampling location.  The
mixing bowl,  stainless steel scoop,  spoon  etc., are to  be
decontaminated between each  sampling point.  See Section  7.8  of
the main  report for details  on  this decontamination procedure.
3.2  Sampling  for  Volatile Chemicals

    Volatile chemicals create  a  special  problem.   Samples
containing volatiles must  be  collected  in a form that will
prevent loss  from volatilization.  Water samplers use  what  is
called a "headspace jar".   These  do not work well with soil
because it is impossible to exclude all air  space with the cores.


Compositing  speeds up volatilization  therefore it cannot be  used
as a sampling  method with  these  chemicals.   The  following
procedure is used  in lieu of the "headspace  jars".
    3.2.1  Soil Sampler

    One of two  types of samplers can be  used to obtain cores from
the soil.  The U.S. Army Corps of Engineers tube density sampler
drives a 5.1  cm  (2  in)  diameter tube into the soil to collect  a
soil sample.  The  tubes are machined  to a  predetermined weight
and inside diameter.   These  tubes can be reused and are  small
enough for handling during surface sampling efforts.
    The second  sampler  is the  short 45.7 cm (10 in )  split  spoon
with ring liners.   The  spoon with liners can  be driven  into  the
soil  with a sledge hammer or with  a  sample jack such as  the
Soiltest Hydraulic  Forta-Sampler .  The split spoon retains  the
soil core  inside  of a brass  liner.  A 15 cm long ring  liner
should  be  used  for the sample.   (This same  system can be used
where  a depth profile  is desired.)   A  series of ring liners of
desired thickness  are  included  in  the split  spoon. The soil in
each ring is  analyzed separately.
    3.2.2 Collection  of Sample

    The tubes, either  split spoon  or  density sampler are forced
into the soil  to the desired depth.  The tubes are extracted and
sealed with  a  precleaned teflon cap, then  tightly wrapped  with
duct tape and coated  with a non-contaminating sealing compound.
Three samples  will be taken at each  location.
    3.2.3  Transport  and Analysis

    The sealed  soil-tube  unit will be shipped to the laboratory
in locked ice chests cooled with dry ice.  They will be stored in
a cooler maintained at 4  C.  The tubes will not be opened until
time for  extraction  of the organic chemicals.  The tube will be
opened  and the  soil extruded into the extraction vessel or  else
placed  in a  tube furnace where  the volatile organics can  be
driven  off  at  the  appropriate  temperatures.  With these
relatively short  tubes  it may be possible to place the soil and
the split spoon liner  into the tube furnace  without having  to
extrude the soil.

                         SECTION B-4

4.1 Records
    Maintain  a  logbook of  the operations alonq with  all
appropriate site description  forms, photographs and  maps showing
the sampling  locations and the  collection sites.  All samples are
to be tagged  with NEIC tags and chain-of-custody forms are to  be
filled out by  the  sample collector and accompany  the samples
until the  analysis is complete.
4.2 Security

    Samples  are to be in the physical'possession  of  the sample
collector or within his immediate view at all times.   If they
must be left in a vehicle,  the  vehicle is to be locked at any
time the sample collector is away from the vehicle.  The NEIC
chain-of-custody  procedures are to be rigidly adhered  to at all
t ime s.
4.3 Safety

    The chemicals of concern  to  the  environmental sampler are
usually toxic.  Some are extremely hazardous.  Prior to  extensive
sampling under this protocol,  the  field team should determine the
nature  of  the chemicals present  and provide  adequate  safety
measures.  Gloves should be worn at all times.   Make  sure that
the gloves  and safety clothing  worn will stand up to the solvents
used in decontamination.  If volatile chemicals are involved, it
may be  necessary to wear charcoal filter masks such  as  the
American Optical Organic Vapor Respirator.   NEIC and the EPA
Safety Officer can advise on the best  equipment to use.   OSHA and
NIOSH can  also  assist in determining the  proper equipment if
there are any questions on what should be worn.

4.4 Site  Restoration
    Experience  has  shown that often  there can be some  terrain
damage to the study  area  from vehicle  traffic.   This  damage must
be repaired by the sampling crew immediately following the field
work.  This  should  be done within a couple of davs  of the sample
collection in order  to avoid problems with the land  owners.

                          SECTION B-5

                         DATA ANALYSIS
    The results  of  the analysis will  be subjected  to  a  series of
statistical  tests.   The following  is a suggestion.  The final
tests  should  be determined  after  close consultation  with the
statistician.   Details of the methods are not discussed here
because standard reference materials and computer  packages such
as Stat Pac  can. be  used  to conduct the  analysis.   The  steps are
listed below.
              Calculate the mean and standard
              deviation for the control and the
              polluted area data.

              Use  the t-statistic to determine a
              confidence  interval for the background.
              Use  the 95% significance level.

              Determine which samples are above the
              background  level.

              Plot the location and concentrations of
              the  samples on a map.

              Delineate the contaminated area.

              If  isopleths are desired, conduct

              Plot isopleth map.

              Plot error map.

              Calculate the error mean square for
              differences between adjacent points.

                          SECTION B-6

    The sampling  effort outlined  in  this protocol requires a
minimum of two people.  A third person can  greatly  facilitate the
work and should be  included if possible.  Two  members lay out the
grid  and collect the  samples.   The  third member  takes the
photographs,  prepares the site description and map and handles
all tagging  and record keeping.
6.1  Equipment and Supplies.
             10 to 12  Oakfield  tube  samplers,
             Model 22-g obtained  from Soil Test,
             Borebrush  for cleaning.
             10 to 12 ten-quart  stainless steel
             mixing bowls.
             A  U.  S. Army Corps of Engineers tube
             density sampling  set with 30 to 40
             six-inch sample tubes.
             Safety equipment  as specified by
             safety officer.
             One-quart Mason  type canning  jars
             with  Teflon liners  (order 1.5 times
             the number of samples.  Excess  is  for
             breakage and contamination losses.).
             A  large supply of heavy-duty plastic
             trash bags.
             Sample tags.
             Chain-of-custody forms.
             Site  description forms.
             Camera with black-and-white film.
             Stainless steel spatulas.
             Stainless steel scoops.
             Stainless steel tablespoons.
             Caps  for density sampling  tubes.
             Case  of duct tape.
             100-foot steel tape.
             2  chain surveyor's tape.
             Tape  measure.
             Noncontarninating sealant for volatile
             sample tubes.
             Supply of survey stakes.

Plot plan.
Sledge hammer.
Ice chests  with locks.
Dry ice.
Communication equipment.
Large  supply of small plastic bags
for samples.

                          APPENDIZ C


                         SECTION C-l

    This  protocol  can be used  for those  situations where
contaminated groundwater has moved from  the ooint of Deposition.
The contaminated soils are  likely  to be located at considerable
depth  below the  surface.   The  soil  scientist  is  not only
interested  in  the horizontal spatial pattern  but also the
vertical pattern.  Sampling  in  this situation requires power
equipment  such as truck mounted augers and coring devices.  The
cost of sample collection becomes an overriding consideration.
Litigation is  a definite possibility;  therefore,  extreme care
must be taken to insure the integrity of  the samples.

Samples are  to be collected with  a 60.9  cm (24 in) split spoon
sampler operated  in  conjunction  with a 20.3 cm (8 in) auger.
This procedure allows  discrete samples  to be collected from the
various strata found below ground  level.   The nature of the
subsoils  is such  that  compositing is not used except  in rare
cases.   The  layers of soil  provide avenues for migration of the
pollutants.  These should  be  sampled individually rather than  in
a composite.   Compositing can  be  used if  the  soil  is very
homogeneous, a rare  occasion in  most soils.  The decision  to
composite should  be  made  only after preliminary coring  has
determined  that the  soils are in fact homogeneous.  Sampling  in
soft soils will require retainers  in the  end of  the split spoon.

    A rectangular or  square grid  is  recommended because of the
plume.  Random samples often fail to reveal the presence of
highly contaminated plumes unless a very high  sampling intensity
is used.  The grid overcomes the problems encountered with random
samples by covering the entire  area of suspected contamination.

                         SECTION C-2

                       SAMPLING DESIGN
    A rectangular grid pattern  is recommended.  The long  axis of
the rectangle should be located along  the  axis of the plume or
suspected plume.   Investigation of well  logs and consultations
with geologists will determine  the direction of groundwater flow,
thus allowing  the  plumes  general  direction  to be determined.
Samples should also  be collected  on  the  upstream side  of  the
source.  The author has observed situations  when two phases of
chemical  pollutant would move  in  opposite directions.
Exploratory drilling prior  to  initiation  of the study will
provide  the necessary information to determine  if there is a need
for a more complete grid pattern around the total circumference
of the source.

    A preliminary study is recommended even  when  there  is  no
reason  to  suspect  that there may be  a large area  of
contamination.  This allows  the  statisticians to develop a
complete picture of  the data needs before the study is  begun.
The preliminary study also is a means for  the laboratories to
prepare  to  receive the samples and to have a chance to obtain
standards and work out potential  problems with the analyses
before the main load of samples comes  into  the  laboratory.
2.1 Minimum Number of Samples

    The large equipment needed  for  the  deep sampling efforts
requires considerable cost;   therefore,  the total number of
samples will be controlled by the budget  for the study.  The
resources available for the study therefore  must be committed
before the study planning  is begun  in  any great detail.  The
equation presented below (equation 6.2.3 of the main body  of the
report) can be used to calculate the number of samples.

                      c '  co + nCs + nCa

The costs are  for  the total cost,  fixed costs, sampling costs  and
analytical costs respectively.  The equation can be rearranged to
yield the number of samples as follows:

                   K  —  i  n  —  f*  \ /1 i"  * P  ^
                   n  —  \  v.    v,  I / ( v-  T v_  )
                             o      s    a
Once the number of samples  is determined,  the calculated n value
is entered into  equation 6.2.2  which  is then  solved  for  the
t-value.  The  rearranged equation  appears  below.

                       t  =-/(n p2/ CV2)

The terms are  as described in the  main body of the report on page
25.  The  calculated  t-value is compared  with the t-value in  the
statistical  tables.   Interpolate  to find  the  level   of
significance  or  probability that  the  number of samples will
provide.   The allowable error (or the percentage difference that
you desire to detect)  ,  (p)  , can  be  taken  as the confidence
interval on a  background sample set, or  the  detection  level of
the method of analysis,  or a known sampling error for the types
of situations  encountered during plume sampling.
2.2 Grid  Layout

    The sampling  grid  should be aligned with the axis of  the
suspected plume.  Where  information  is  not available  for
determining this,  the axis should be elongated with the direction
of groundwater  flow.   The number  of  grid points should closely
fit the number  of  samples calculated  in  Section 2.1 above.   An
attempt should  be  made to determine  the  approximate limits of
contamination.  This can usually be done  in  conjunction with  the
hydrogeologists  that are usually  involved with any study dealing
with underground plumes.  The rate and  extent of migration can be
used as a rough estimate of  the  extent of contamination.   The
size of  the  grid  cells then will  be  determined by dividing  the
total area of suspected contamination  by  the allowable number of

    The coordinates of the grid will be those of any X - Y grid
system.   An  appropriate numbering  scheme .can be assigned to  the
grid lines to aid  in locating sampling sites and in coding  tags
and site description forms.  The starting  point for the grid is
located  by the same random process that  is  discussed in Section

2.3 Control  Area
    An appropriate "control  site located  in  an  uncontaminated
portion of the  area  should be obtained  for collecting control
samples.  The  soil  structure should be as nearly  identical to
that in the  study area as can be  found in the immediate  vicinity.
Care must be  taken  to insure that there  is  no communication
underground  between the control sites and that  the control site
is not located  down  wind from any  industrial  source of the same
chemicals.   Candidate control areas should be  sampled prior to
the final selection  to insure that there  are  no unsuspected
sources of  pollutants likely to cause problems in  the analysis
and interpretation  phases.   This preliminary sampling  is
especially important  around major  industrial  areas where past
practices  may have contaminated an area.
2.4 Preliminary  Study

    Many  "plume hunt" studies do  not have  site specific
historical data available  for  use  in  planning the study.  The
systematic sampling grid used in this study allows the  researcher
to work up  to  the  optimum number of  samples  in  stages.   This
phased approach is recommended if the scheduled completion date
will allow  the time  for these  phases  to be carried  out.  Use of
equation 6.2.2 can be  used  to determine the reliability of some
percentage of the total number of samples.   The particular qrid
nodes sampled can  be randomly selected if there is a desire to
sample in  a random fashion  but a subset of data points can be
obtained by  using a coarser grid made up of every  other grid line
or every third grid line.

    This  use of the  grid  designed  for the main  study allows
repeated sampling to be done if  there is a desire  to  determine if
there are seasonal variations in the data and  also  allows for
kriging analysis to be done  on  a portion of the  samples.  Where
kriging is  done  an error  map can be  generated  that will show
where additional  samples  are needed  to reach  the  precision

    Where  the preliminary study  is truly exploratory  (i.e., there
is no data available other  than  visual  or olfactory evidence of a
problem) the use of some form of surrogate analysis is  desirable.
For example, in  some cases total organic halide  analysis can be
used to locate the plume  at a considerably reduced  cost when
compared  to an analysis  like  the gas  chromatographic-mass
spectrographic analysis required for  the standard Priority
Pollutant  Analysis series.   These surrogate tests  can often allow
the outer  limits of contamination to be found in the  field..

                         SECTION C-3

                      SAMPLE COLLECTION
    Sampling  for deep  lying plumes of contaminated soil  is
expensive  and at times quite  difficult to perform.  The approach
used here  is essentially  the ASTM method D1586-67.
3.1 Sampling Equipment

    A truck mounted drill rig  equipped  with A-rod  drilling
equipment or  adaptable  to  the A-rod connector will be used.
Standard  5.1 cm  (2  in) split  spoon samplers that are 61 cm (24
in) long  will be used to  collect  samples.  Samples collected  for
volatile organic chemical analyses will be contained in brass
liners unless stainless steel  liners can be  obtained.  The brass
thin  walled liners will be used  for all  samples unless
compositing is  done  for  some specific reason.  A 20.3 cm (8 in)
diameter soil  auger  will be  used to excavate to the sampling
depth. All samples will  be placed in precleaned one-quart Mason
canning  jars fitted  with a  precleaned teflon lid liner.   Dry
sands, or  soft  noncohesive  soils will require that  the split
spoon be  fitted with a retainer or pocket shoe.
3.2 Non-Volatile  Pollutant Sampling
    3.2.1 Sample extraction

    The split spoon will be  attached to the drill rod and  forced
into  the soil  to  the  full depth of the spoon.  In difficult
soils, a 63.5 kg  (140 Ib)  hammer will be used on the drill rig to
drive the spoon  into the soil.  If  the  soil is loose, wet or in
any way unconsolidated,  use  a  basket retainer in the split spoon.

    The spoon is  then extracted and turned over to the  sampling
crew.   The  drill crew will then attach the  auger and drill down
to the depth of  the  first sample's penetration  (  i.e., to two
feet).  The soil  will be shoveled back from the hole  face.   The
hole  will  then  be cleaned with  the auger by increasing  the
revolutions  as  the  auger is lowered  and returned to the surface.
A second split  spoon will be attached and forced into  the  bottom
of the  hole formed by the auger.  This sample will be extracted
and given to the  sampling crew.  The process will be continued
until the desired depth of sampling is reached.  If large rocks
are encountered  it may be necessary to shift  the sample point to
a second location.  Move  the  rig one meter  north.  If this does
not work move one meter south of  the original hole.  The exact
location  should  be noted in the  log book and on the core log.
The blow counts for the hammer will be recorded on the core log.
    3.2.2 Sample  Preparation

    The split  spoons will.be opened  by  the sampling crew.  The
cores will be  carefully split lengthwise  with a stainless  steel
spatula.   The  color,  texture and any unusual features of the core
will be noted.   Any evidence of chemical  contamination will be
recorded in  the  logbook and on the core log  sheet.  The length of
the core should  be measured as well  as the  depth of any textural
changes or unusual features present in the core.  A standard tape
measure will be  used  for these measurements.

     The sample  will  then be transfered to a precleaned, labeled,
glass canning  jar  fitted with a teflon liner placed next  to  the
sample.   An NEIC  sample tag will be filled out for each sample.
The tag will accompany the sample to the  laboratory.  The outside
of the jar will  be cleaned then it will be double bagged with  the
tag placed in  the  outer bag.

    Any obvious potential  routes  of migration such as sand
lenses, silt  layers or old  root channels should  be sampled
separately.   These  layers are often the  first areas to become
contaminated and  therefore  provide an early warning of future
problems.  Any marked changes in the texture should be sampled as
a separate unit.   If  the number of samples acquired is excessive,
every  second  or third split spoon  sample  can be  taken  for

3.3 Volatile Chemical Sampling

    Samples collected  for volatile chemicals are often difficult
to acquire in a condition suitable for analysis.  The less
disturbance the greater  the chance  that  the  analysis  will be

    Split spoons can  be  fitted  with  liners  made of brass,
stainless steel and  in  some cases,  Teflon.  The samples cannot be
described  on the  well  log so a considerable amount  of
interpretive information is lost.  The core log will be made from
observations of the  material removed by  the auger.  The procedure
for taking the sample is  the  same as  that  presented  above in
Section  3.2.  The extracted core will be  left  in the  liner and
shipped  to the laboratory for analysis.  The ends of the  liner
tube will be sealed  with a  teflon  cap,  then taped with duct tape
and sealed with a non-contaminating sealant.   The samples will
then  be transported  to the  laboratory  in  locked ice chests
maintained at 4  C with dry ice.   The details of sample  handling
are outlined  in the Federal Register  (Federal Register.  Vol
44:69464. December  3,  1979).

3.4 Security

    All  samples will  be  logged,  tagged and  entered on the
standard NEIC chain-of-custody forms.   The samples  will be
maintained either under  constant surveillance or locked in a
limited  access storage area.  If  it is necessary  to place  the
samples  in a vehicle, the vehicle will be kept locked  when
unattended.  The amount of time samples are left unattended in a
vehicle  should be kept  to  a minimum.   Tfie chain-of-custody form
will  be  signed when samples change hands.  The team  leader is
responsible for the samples and  should  insure that they are
turned  over to a responsible party before relinquishing custody
of the samples.
3.5 Safety

    Underground plume  samples often contain  highly  toxic
chemicals.  Extreme  care  should be taken  when  handling the
samples.   Follow  the EPA safety manual  procedures  during
sampling.   It  is better to  overprotect  than  to have someone hurt
because of a  lack  of  diligence  to pursue safety procedures.
Protective  gloves are a minimum protection  for all  members  of the
crew that must  handle the soil  samples.  Crews sampling  around
sources of volatile organic chemicals should have  proper fitting
vapor masks available at all  times.   There are  some situations


where the safety officer may  require the masks  to be worn at all
times.   In areas where the chemical concentrations are known to
be low,  the masks may be carried and donned only when  chemicals
are  detected  by  odor  or  sight.  All auger holes  are  to be
refilled with either grout or  clean soil.
3.6 Decontamination
    Decontamination is a major problem.  The  augers and split
spoons require a pressurized hose and decontamination  facility
that can handle hazardous  wastes.   The augers and split spoons
are to be pressure washed,  scrubbed  then  rinsed with tap water.
If organics are involved,  the split  spoons are  to be rinsed  in
waste acetone, then  methylene chloride.   This is followed by a
distilled water rinse, a spectrographic grade  acetone rinse, then
a spectrographic  grade methylene  chloride rinse.  Inorganic
chemical sampling can eliminate  the solvent rinses.  All  tools,
etc.,  must be cleaned  following  the same  procedure  as  the
sampling equipment.   Save all waste for disposal at a licensed
hazardous waste landfill.

                         SECTION C-4

                        DATA ANALYSIS
    The addition of another  variable, depth,  further complicates
the analysis of  the  data.   Regression techniques often provide
the  best method for handling  this  type of  sampling data
especially  in the  early  stages of an  investigation.  The
preliminary data  should  be used  to determine  the optimum number
of samples if cost  is  not  a major  factor.  Kriging can help
determine the location of  any additional samples  that are needed.
Careful examination of the preliminary data will  often allow  the
researcher to exclude  some samples because of  the homogeneity
and/or thickness of a particular layer. (This  statement is based
upon the fact that the more  homogeneous the media, the fewer  the
number of samples that are required to arrive  at a conclusion
with a predetermined precision.)

    The depth variable requires  that kriging  be conducted  in
three dimensions.  This has  not  been done  although it should  be
possible.  The  mathematics would  be quite  difficult.   An
alternative would be to krige  the  data at each layer  where
samples were collected.   (This assumes that sampling was  done  at
a  common depth throughout  the  entire soil  mass.)   By
superimposing one on top of each other the volume of the plume
can be observed.

    Regression is  to be used to  determine the variables that are
influencing  the migration of  the  pollutants and  to make
comparisons between layers in  the soil and  between locations in
the study site.  The  t-test  can be  used to  develop a confidence
interval for comparing the contaminated and uncontaminated areas.
Use kriging to develop isopleth  and error maps for the area.

                          SECTION C-5
5.1 Staffing
          • Drill  crew of three men.
          • Sampling crew  of three  men  (two sample
            collectors and one record keeper).
          • One runner to acquire supplies and handle
            dec on tarn in a t ion.
5.2 Equipment and Supplies
          • Drill  rig  equipped with A-rod  fittings or
            adaptors and an 8  inch auger.
          • 25 two-foot  sections of 2 inch split  spoon
            Brass  or stainless steel liners.
            Teflon caps  for liners.
            Drums  for  hauling waste material.
            Grout  and  clean soil for refilling holes.
            One-quart Mason  jars  ( use 1.5  times the
            number of  samples expected.)
            Safety equipment.
            Surveyor's chain.
            Survey stakes.
            Case of duct tape.
            Non-contaminating sealant.
            All core logs, notebooks, etc.
            Chain-of-custody  forms.
            Ample  supply of small  plastic bags to hold
            sample bottles.
            Ice chests with pad locks.
            Dry ice.
            Heavy-duty plastic trash bags.
            Communication equipment.