ETL 1110-1-175
30 Jun 97
likewise fashion, scientific findings may define the
particular HTRW site investigation and also have
scope of administrative effort.
a good basic understanding of the fundamental
geostatistical techniques. As alluded to here and
(2) Scientists and engineers involved in
elsewhere in this ETL, there are many techniques
HTRW site investigations have found that they
available for gridding data; kriging has an added
have an implicit need for many disciplines to fulfill
advantage of generating kriging standard devia-
the objectives of each particular investigation.
tions that can be used as a measure of uncertainty.
Frequently, an HTRW site investigation will
b. Initial planning.
benefit from input from earth-science disciplines
such as geology, hydrogeology, and chemistry,
among others. Some HTRW site investigations are
(1) Initial planning may involve several
large enough to use several individuals from each
aspects associated with implementing or operating
of these disciplines, as well as many others, for the
a monitoring network; it also may involve recon-
duration of multi-year investigations. Most disci-
naissance evaluation of an existing network. Addi-
plines associated with HTRW site investigations
tionally, because monitoring is present in all
will benefit from knowledge or input from special-
phases of HTRW site investigations, the same
ized and/or interdisciplinary branches; the geolo-
opportunities for geostatistical applications asso-
gist, for example, will occasionally benefit from
ciated with network analysis that occur in the
knowledge of geophysics. Naturally, interdisci-
initial planning stages may occur, perhaps often,
plinary input also can be very helpful, especially in
throughout the investigation. The information
geostatistics, where earth-science disciplines rely
available from kriging standard deviations can add
on assistance from statisticians.
much to sampling or monitoring network analysis.
(3) In this ETL and for its purposes, a com-
(2) For application of geostatistical tech-
plete HTRW site investigation is described con-
niques, the most likely aspects of network imple-
cerning three relatively broad sequential activities
mentation and operation to be addressed certainly
or phases. These phases are referred to as initial
include network design, evaluation, and modifi-
planning, analysis, and implementation of remedia-
cation. Geostatistics offer the investigator oppor-
tion plans. Another very important HTRW site
tunities to:
investigation activity, monitoring, is less discrete
and is a part of all three phases. Monitoring
(a) Locate areas where existing sampling or
represents the basis for analysis, is often modified
monitoring networks may provide strong or weak
as a result of analysis, and may be newly imple-
estimates.
mented as part of remediation.
(b) Quantify the effect of increasing or
(4) Kriging techniques can and have been used
decreasing the sampling or monitoring network
in any of the three phases. Only a few very basic
density.
applications of kriging techniques are described in
this ETL. The intent of this ETL is to describe
(c) Evaluate the effect of removing or relocat-
basic concepts so that more elaborate applications
ing certain monitoring locations or adding new
can be done based on a fundamental understanding
locations to the sampling or monitoring network.
of the procedures involved.
c. Analysis.
(5) For examples of more elaborate applica-
tions, the reader can refer to the material cited in
(1) Although aspects of network design can be
Chapter 3. However, the best applications are
quite important during analysis, the investigator is
developed by readers who have a clear under-
likely to be concerned principally with using infor-
standing of the goals associated with each
mation from monitoring networks to evaluate
1-3
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