United States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
EPA/540/2-91/020B
September 1991
4>EPA
Guide for Conducting Treatability
Studies under CERCLA:
Soil Washing
Office of Emergency and Remedial Response
Hazardous Site Control Division OS-220
QUICK REFERENCE FACT SHEET
Section 121 (b) of CERCLA mandates that EPA should select remedies that "utilize permanent solutions and alternative
treatment technologies or resource recovery technologies to the maximum extent practicable" and that EPA should prefer
remedial actions in which treatment that "permanently reduces the volume, toxicity, or mobility of hazardous substances,
pollutants, and contaminants is a principal element." Treatability studies provide data to support treatment technology selection
and remedy implementation and should be performed as soon as it is evident that insufficient information is available to ensure
the quality of the decision. Conducting treatability studies early in the remedial investigation/feasibility study (RI/FS) process
should reduce uncertainties associated with selecting the remedy, and provide a sounder basis for the ROD. Regional planning
should factor in the time and resources required for these studies.
This fact sheet provides a summary of information to facilitate the planning and execution of soil washing remedy selection
treatability studies in support of the RI/FS and the remedial design/remedial action (RD/RA) processes. This fact sheet follows
the organization of the "Guide for Conducting Treatability Studies Under CERCLA: Soil Washing," Interim Guidance,
EPA/540/OOO/OOOA September 1991. Detailed information on designing and implementing remedy selection treatability studies
for soil washing is provided in the guidance document.
INTRODUCTION
There are three levels or tiers of treatability studies:
remedy screening, remedy selection, and remedy design. The
"Guide for Conducting Treatability Studies Under CERCLA:
Soil Washing Remedy Selection" discusses the remedy
screening and remedy selection levels.
Remedy screening studies are designed to provide a
quick and relatively inexpensive indication of whether soil
washing is a potentially viable remedial technology. Soil
washing remedy screening studies should not be the only
level of testing performed before final remedy selection.
Remedy selection and remedy design studies will also be
required to determine if soil washing is a viable treatment
alternative for a site. The remedy selection evaluation should
provide an indication that reductions in contaminant
concentrations or in the volume of contaminated soil will meet
site-specific cleanup goals. It will also produce the design
information required for the next level of testing. Remedy
design studies may be needed to optimize process design.
TECHNOLOGY DESCRIPTION AND
PRELIMINARY SCREENING
Technology Description
Soil washing is a physical/chemical separation
technology in which excavated soil is pretreated to remove
large objects and soil clods and then washed with fluids to
remove contaminants. To be effective, soil washing must
either transfer the contaminants to the wash fluids or
concentrate the contaminants in a fraction of the original soil
volume, using size separation techniques. In either case, soil
washing must be used in conjunction with other treatment
technologies. Either the washing fluid or the fraction of soil
containing most of the contaminant, or both, must be treated.
At the present time, soil washing is used extensively in
Europe and has had limited use in the United States. During
1986-1989, the technology was one of the selected source
control remedies at eight Superfund sites.
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The determination of the need for and the appropriate level
of treatability studies required is dependent on the literature
information available on the technology, expert technical
judgment, and site-specific factors. Several reports and
electronic data bases exist that should be consulted to assist
in planning and conducting treatabilty studies as well as help
prescreen soil washing for use at a specific site. Site-specific
technical assistance is provided to Regional Project Managers
(RPMs) and On-Scene Coordinators (OSCs) by the Technical
Support Project (TSP).
Prescreening Characteristics
Prescreening activities for the soil washing treatability
testing include interpreting any available site-related field
measurement data. The purpose of prescreening is to gain
enough information to eliminate from further treatability testing
those treatment technologies which have little chance of
achieving the cleanup goals.
The three most important soil parameters to be evaluated
during prescreening and remedy screening tests are the grain
size distribution, clay content, and cation exchange capacity.
Soil washing performance is closely tied to these three
factors. Soils with relatively large percentages of sand and
gravel (coarse material >2 mm in particle size) respond better
to soil washing than soils with small percentages of sand and
gravel. Larger percentages of clay and silt (fine particles
smaller than 0.25 mm) reduce soil washing contaminant
removal efficiency. In general, soil washing is most
appropriate for soils that contain at least 50 percent
sand/gravel, i.e., coastal sandy soils and soils with glacial
deposits. Soils rich in clay and silt tend to be poor candidates
for soil washing. Cation exchange capacity measures the
tendency of the soil to exchange weakly held cations In the
soil for cations in the wash solution, which will be more
strongly bound to the soil. Soils with relatively low CEC values
(less than 50 to 100 meq/kg) respond better to soil washing
than soils with higher CEC values. Early characterization of
these parameters and their variability throughout the site
provides valuable information for the initial screening of soil
washing as an alternative treatment technology.
Chemical and physical properties of the contaminant
should also be investigated. Solubility in water (or other
washing fluids) is one of the most important physical
characteristics. Reactivity with wash fluids may, in some
cases, be another important characteristic to consider. Other
contaminant characteristics such as volatility and density
may be important for the design of remedy screening studies
and related residuals treatment systems. Speciation is
important in metal-contaminated sites. Specific metal
compounds should be quantified rather than total metal
concentration for each metal present at the site.
There is no steadfast rule that specifies, when to proceed
with remedy screening and when to eliminate soil washing as
a treatment technology based on a preliminary screening
analysis. A literature search indicating that soil washing may
not work at a given site should not automatically eliminate soil
washing from consideration. On the other hand, previous
studies indicating that pure chemicals will be effectively
treated using soil washing must be viewed with caution.
Chemical interactions in complex mixtures frequently found at
Superfund sites or interactions between soil and contaminants
can limit the effectiveness of soil washing. An analysis of the
existing literature, coupled with the site characterization, will
provide the information required to make an "educated
decision." However, when in doubt, a remedy screening study
is recommended.
Technology Limitations
Many factors affect the feasibility of soil washing. These
factors should be addressed prior to the selection of soil
washing, and prior to the investment of time and funds in
further testing. A detailed discussion of these factors is
beyond the scope of this document.
THE USE OF TREATABILITY STUDIES IN
REMEDY SELECTION
Treatability studies should be performed in a systematic
fashion to ensure that the data generated can support the
remedy evaluation and implementation process. A
well-designed treatability study can significantly reduce the
overall uncertainty associated with the decision but cannot
guarantee that the chosen alternative will be completely
successful. Care must be exercised to ensure that the
treatability study is representative of the treatment as it will be
employed (e.g., the sample is representative of the
contaminated soil to be treated) to minimize the uncertainty
in the decision. The method presented below provides a
resource-effective means for evaluating one or more
technologies.
There are three levels or tiers of treatability studies:
remedy screening remedy selection and remedy design.
Some or all of the levels may be needed on a case-by-case
basis. The need for, and the level of, treatability testing
required are management decisions in which the time and
cost necessary to perform the testing are balanced against
the risks inherent in the decision (e.g., selection of an
inappropriate treatment alternative). Figure 1 shows the
relationship of three levels of treatability study to each other
and to the RI/FS process.
Remedy Screening
Remedy screening is the first level of testing. It is used to
establish the ability of a technology to treat a waste. These
studies are generally low cost (e.g., $10,000 to $50,000) and
usually require hours to days to complete. The lowest level of
quality control is required for remedy screening studies. They
yield data enabling a qualitative assessment of a technology's
potential to meet performance goals. Remedy screening tests
can identify operating standards for investigation during
remedy selection or remedy design testing. They generate
little, if any, design or cost data, and should never be used as
the sole basis for selection of a remedy.
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Remedial Investigation/
Feasibility Study (RI/FS)
Identification
of Alternatives
Record of
Decision
(ROD)
Remedy
Selection
Remedial Design/
Remedial Action
(RD/RA)
Scoping
— the -
RI/FS
Site
Characterization
and Technology
Screening
REMEDY
SCREENING
to Determine
Technology Feasibility
Evaluation
of Alternatives
REMEDY SELECTION
to Develop Performance
and Cost Data
Implementation
of Remedy
REMEDY DESIGN
to Develop Scale-Up, Design,
and Detailed Cost Data
Figure 1. The Role of Ttreatability Studies in the RI/FS and RD/RA Process.
Remedy screening soil washing treatability studies are
frequently skipped. Often, there is enough information about
the physical and chemical characteristics of the soil and
contaminant to allow an expert to evaluate the potential
success of soil washing at a site. When performed, remedy
screening tests are jar tests. However, remedy selection tests
are normally the first level of treatability study executed.
Remedy Selection
Remedy selection testing is the second level of testing.
Remedy selection tests identify the technology's performance
for a site. These studies have a moderate cost (e.g., $20,000
to $100,000) and require several weeks to complete. Remedy
selection tests yield data that verify that the technology can
meet expected cleanup goals, provide information in support
of the detailed analysis of alternatives (i.e., seven of the nine
evaluation criteria), and give indications of optimal operating
conditions.
The remedy selection tier of soil washing testing generally
consists of laboratory tests which provide sufficient
experimental controls such that a semi-quantitative mass
balance can be achieved. Toxicity testing of the cleaned soil
is typically employed in the remedy selection tier of
treatability testing. The key question to be answered during
remedy selection testing is how much of the soil will this
process treat by either particle size separation or
solubilization to meet the cleanup goal. The exact removal
efficiency needed to meet the specified goal for the remedy
selection test is site-specific. In some cases, pilot-scale
testing may be appropriate to support the remedy evaluation
of innovative technologies. Typically, a remedy design study
would follow a successful remedy selection study.
Remedy Design
Remedy design testing is the third level of testing. It
provides quantitative performance, cost, and design
information for remediating an operable unit. This testing also
produces remaining data required to optimize performance.
These studies are of moderate to high cost (e.g., $100,000 to
$500,000) and require several months to complete. For
complex sites (e.g., sites with different types or
concentrations of contaminants in different areas or with
different soil types in different areas), longer testing periods
may be required, and costs will be higher. Remedy design
tests yield data that verify performance to a higher degree
than the remedy selection and provide detailed design
information. They are performed during the remedy
implementation phase of a site cleanup.
Remedy design tests usually consist of bringing a mobile
treatment unit onto the site, or constructing a small-scale unit
for nonmobile technologies. Permit exclusions may
be available for offsite treatability studies under
certain conditions. The goal of this tier of testing is
to confirm the cleanup levels and treatment times
specified in the Work Plan. This is best achieved
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by operating a field unit under conditions similar to those
expected in the full-scale remediation project.
Data obtained from the remedy design tests are used to:
Design the full-scale unit
Confirm the feasibility of soil washing based on target
cleanup goals
Refine cleanup time estimates
Refine cost predictions.
Given the lack of full-scale experience with innovative
technologies, remedy design testing will generally be
necessary in support of remedy implementation.
REMEDY SELECTION TREATABILITY
STUDY WORK PLAN
Carefully planned treatability studies are necessary to
ensure that the data generated are useful for evaluating the
validity or performance of a technology, The Work Plan, which
is prepared by the contractor when the Work Assignment is
in place, sets forth the contractor's proposed technical
approach for completing the tasks outlined in the Work
Assignment. It also assigns responsibilities and establishes
the project schedule and costs. The Work Plan must be
approved by the RPM before initiating subsequent tasks. A
suggested organization of the Work Plan is provided in the
"Guide for Conducting Treatability Studies Under CERCLA
Soil Washing."
Test Goals
Setting goals for the treatability study is critical to the
ultimate usefulness of the data generated. Goals must be
defined before the treatability study is performed. Each tier of
treatability study needs performance goals appropriate to that
tier.
Remedy screening tests are not always performed for soil
washing processes. If remedy screening tests are performed,
an example of the goal for those tests would be to show that
the wash fluid will solubilize or remove a sufficient percentage
(e.g., 50 percent) of the contaminants to warrant further
treatability studies. Another goal might be to show that
contaminant concentrations can be reduced in the >2 mm soil
fraction by at least 50 percent, as compared to the original
soil concentrations, using particle size separation techniques.
These goals are only examples. The remedy screening
treatabilty study goals must be determined on a site-specific
basis.
Achieving the goals during this tier should merely indicate
that soil washing has at least a limited chance of success
and that further studies will be useful. Frequently, such
information is available based on the type of soil and
contaminant present at the site. Based on such information,
experts in soil washing technology can often assess the
potential applicability of soil washing without performing
remedy screening.
The main objectives of the remedy selection tier of testing
are to:
Measure the percentage of the contaminant that can
be removed from the soil through solubilization or
from the >2 mm soil fraction by particle size
separation.
Produce the design information required for the next
level of testing, should the remedy selection
evaluation indicate remedy design studies are
warranted.
The actual goal for removal efficiency must be based
on site- and process-specific characteristics. The
specified removal efficiency must meet site cleanup
goals, which are based on a site risk assessment or
on the applicable or relevant and appropriate
requirements (ARARs).
Experimental Design
A jar test is the type of remedy screening test that can be
rapidly performed in an onsite laboratory to evaluate the
potential performance of soil washing as an alternative
technology. Such studies should be designated to maximize
the chances of success at the remedy screening level. The
object of this guidance document is not to specify a particular
remedy screening method but rather to highlight those critical
parameters which should be evaluated during the laboratory
test.
Contaminant characteristics to examine during remedy
screening include solubility, miscibility, and dispersibility.
Properties of organic contaminants are generally easier to
evaluate than those of inorganic contaminants. Inorganics,
such as heavy metals, can exist in many compounds (e.g.,
oxides, hydroxides, nitrates, phosphates, chlorides, sulfates,
and other more complex mineralized forms), which can greatly
alter their solubilities. Metal analyses typically provide only
total metal concentrations, More detailed analyses to
determine chemical speciation may be warranted.
The liquid used in the jar test is typically water, or water
with additives which might enhance the effectiveness of the
soil washing process. To save time and money, chemical
analyses should not be performed on the samples until there
is visual evidence that physical separation has taken place in
the jar tests. Jar tests can yield three separate fractions from
the original soil sample. These include a floating layer, a
wastewater with dispersed solids, and a solid fraction.
Chemical analysis can be performed on each fraction.
When performing the jar test, observe if any floating
materials can be skimmed off the top. Observe whether an
immiscible, oily layer forms, either at the top or the bottom,
indicating release of an insoluble organic material. Observe
and time the solids settling rate and depth. Sand and
gravel settle first, followed by the silt and clay. The
rate and the relative volume of the settling material will
provide some indication of the particle size distribution
in the waste matrix and the potential for soil washing
as a treatment alternative. Further evidence can be
gained by analyzing the settled and filtered wash water
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for selected indicator contaminants of concern. If simple
washing releases a large percentage of these contaminants
into the wash water, then soil washing can be viewed favorably
and more detailed laboratory and bench tests must be
conducted.
Variations on the jar tests can include the addition of
surfactants, chelants, or other dispersant agents to the water;
sequential washing; heated water washing versus cold water;
acidic or basic wash water; and tests that include both a
wash and a rinse step. The rinse water and fine soil fraction
(<2 mm particle size) should be separated from the coarse
soil fraction (>2 mm particle size) using a #10 sieve. No
attempt should be made during jar tests to separate the soil
into discrete size fractions; this is done at the bench-scale
tier of testing. Normally, only the coarse soil fraction should
be analyzed for contamination. In general, at least a 50
percent reduction in total contaminant concentration in the >2
mm soil fraction is considered adequate to proceed to the
remedy selection tier. The separation of approximately 50
percent of the total soil volume as clean soil also indicates
remedy selection studies may be warranted.
To reduce analytical costs during the remedy screening
tier, a condensed list of known contaminants must be
selected as indicators of performance. The selection of
indicator analytes to track during jar testing should be based
on the following guidelines:
Select one or two contaminants present in the soil
that are most toxic or most prevalent.
Select indicator compounds to represent other
chemical groups if they are present in the soil (i.e.,
volatile and semivolatile organics, chlorinated and
nonchlorinated species, etc.)
If polychlorinated biphenyls (PCBs) and dioxins are
known to be present, select PCBs as indicators in
the jar tests and analyze for them in the washed soil.
It is usually not cost-effective to analyze for dioxins
and other highly insoluble chemicals in the wash
water generated from jar tests. Check for them later
in the wash water from remedy selection tests.
Remedy selection tests require that electricity, water, and
additional equipment are available. The tests are run under
more controlled conditions than the jar tests. The response of
the soil sample to variable washing conditions is fully
characterized. More precision is used in weighing, mixing,
and particle size separation. There is an associated increase
in QA/QC costs. Treated soil particles are separated during
the sieve operations to determine contaminant partitioning
with particle size. Chemical analyses are performed on the
sieved soil particles as well as on the spent wash waters. The
impact of process variables on washing effectiveness is
quantified. This series of tests is considerably more costly
than jar tests, so only samples showing promise in the
remedy screening phase (jar test) should be carried forward
into the remedy selection tier. If sufficient data are available in
the prescreening step, the remedy screening step may be
skipped. Soil samples showing promise in the prescreening
step are carried forward to the remedy selection tier.
A series of tests should be designed that will provide
information on washing and rinsing conditions best suited to
the soil matrix under study. The RREL data base should be
searched for information from previous studies. To establish
percent of contaminant removal, particle size separation, and
distribution of contaminants in the washed soil, the following
should first be studied: 1) wash time, 2) wash water-to-soil
ratio, and 3) rinse water-to-wash water ratio. Following those
studies, the effect of wash water additives on performance
should be evaluated.
Several factors must be considered in the design of soil
washing treatability studies. A remedy selection test design
should be geared to the type of system expected to be used
in the field. Soil-to-wash water ratios should be planned using
the results from the jar tests, if jar tests were performed. In
general, a ratio of 1 part of soil to 3 parts of wash water will be
sufficient to perform remedy selection tests. The soil and
wash water should be mixed on a shaker table for a minimum
of 10 minutes and a maximum of 30 minutes. The soil-to-wash
water ratio and mix times presented here are rules of thumb
to be used if no other information is available.
Another factor to consider is the variability of the grain
size distribution. Gilsen Wet Sieve devices are recommended
for remedy selection studies. Ro-Tap or similar sieve systems
may also be used. Such devices will enhance the
completeness and reproducibility of grain size separation.
However, they are messy, expensive, and very noisy when in
operation. An alternate choice is to complete a series of four
to six replicate runs under exactly the same set of conditions
to obtain information on the variability of the grain size
separation technique. Variability in the separation technique
can be evaluated by comparing sieve screen weights across
runs and soil contaminant data for the same fractions from
each run. By identifying the range of variability associated with
repeated runs at the same conditions, estimates can be made
of the variability that is likely to be associated with other test
runs under slightly different conditions.
Normally, only the wash water and the soil particles
captured by the sieve screen need to be analyzed for
contaminants. Experience has shown that little additional
contaminant removal is likely to be found in the rinse water.
Rinsing is important and must be included in the procedure
since it improves the efficiency of the grain size
separation/sieving process. Rinsing separates the fine from
the coarse material. This can result in a cleaner coarse
fraction and more contaminant concentrated in the fine
fraction. Contaminant concentration in the rinse water may be
determined periodically (e.g., 10 percent of the samples) to
evaluate the performance of the wash solution. However, very
little contamination is typically dissolved in the rinse solution.
Therefore, analyses of the rinse solution may have limited
value in verifying wash solution performance.
Initially, only the coarse soil fraction and the
wash water should be analyzed for indicator contaminants.
If the removal of the indicator contaminants confirms
that the technology has the potential to meet cleanup
standards at the site, additional analyses
should be performed. All three soil fractions and all wash and
rinse waters must be analyzed for all contaminants to
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perform a complete mass balance. The holding time of soil
fractions in the lab before extraction and analysis can be an
important consideration for some contaminants.
The decision on whether to perform remedy selection
testing on hot spots or composite soil samples is difficult and
must be made on a site-by-site basis. Hot spot areas should
be factored into the test plan if they represent a significant
portion of the waste site. However, it is more practical to test
the specific waste matrix that will be fed to the full-scale
system over the bulk of its operating life. If the character of the
soil changes radically (e.g., from day to sand) over the depth
of contamination, then tests should be designed to separately
study system performance on each soil type.
Additives such as oil and grease dispersants and
chelating agents can aid in removing contaminants from some
soils. However, they can also cause processing problems
downstream from the washing step. Therefore, use of such
additives should be approached with caution. Use of one or a
combination of those additives is a site-by-site determination.
Some soils do not respond well to additives. Surfactants and
chelating agents may form suspensions and foams with soil
particles during washing. This can clog the sieves and lead to
inefficient particle size separation during screening. The result
can be the recovery of soil fractions with higher contamination
than those cleaned by water alone. Such results can make
the data impossible to understand. Additives can also
complicate the rinse water process that might follow the soil
washing. Recent studies have shown that counter-current
washing-rinsing systems, incorporating the use of hot water
for the initial wash step, offer the best performance in terms of
particle size separation, contaminant removal, and wastewater
management (treatment, recycling and discharge).
SAMPLING AND ANALYSIS PLAN
The Sampling and Analysis Plan (SAP) consists of two
parts-the Field Sampling Plan (FSP) and the Quality
Assurance Project Plan (QAPjP). A SAP is required for all
field activities conducted during the RI/FS. The purpose of the
SAP is to ensure that samples obtained for characterization
and testing are representative and that the quality of the
analytical data generated is known. The SAP addresses field
sampling, waste characterization, and sampling and analysis
of the treated wastes and residuals from the testing apparatus
or treatment unit. The SAP is usually prepared after Work
Plan approval.
Field Sampling Plan
The FSP component of the SAP describes the sampling
objectives; the type, location, and number of samples to be
collected; the sample numbering system; the necessary
equipment and procedures for collecting the samples; the
sample chain-of-custody procedures; and the required
packaging, labeling, and shipping procedures.
Field samples are taken to provide baseline contaminant
concentrations and material for the treatability studies. The
sampling objectives must be consistent with the treatability
test objectives. Because the primary objective of remedy
screening studies is to provide a first-cut evaluation of the
extent to which specific chemicals are removed from the soil
or concentrated in a fraction of the soil by soil washing, the
primary sampling objectives should include, in general:
Acquisition of samples representative of conditions
typical of the entire site or defined areas within the
site. Because this is a first-cut evaluation, elaborate
statistically designed field sampling plans may not be
required. Professional judgment regarding the
sampling locations should be exercised to select
sampling sites that are typical of the area (pit,
lagoon, etc.) or appear above the average
concentration of contaminants in the area being
considered for the treatability test. This may be
difficult because reliable site characterization data
may not be available early in the remedial
investigation.
Acquisition of sufficient sample volumes necessary
for testing, analysis, and quality assurance and
quality control.
The sampling plan for remedy selection will be similar.
However, because a mass balance is required for this
evaluation, a statistically designed field sampling plan will be
required.
Quality Assurance Project Plan
The Quality Assurance Project Plan should be consistent
with the overall objectives of the treatability study. At the
remedy screening level the QAPjP should not be overly
detailed.
The purpose of the remedy selection treatability study is
to determine whether soil washing can meet cleanup goals
and provide information to support the detailed analysis of
alternatives (i.e., seven of the nine evaluation criteria). An
example of a criterion for this determination is removal of
approximately 90 percent of contaminants. The exact removal
efficiency specified as the goal for the remedy selection test
is site-specific. The suggested QC approach will consist of:
Triplicate samples of both reactor and controls
The analysis of surrogate spike compounds in each
sample
The extraction and analysis of a method blank with
each set of samples
The analysis of a matrix spike in approximately 10
percent of the samples.
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The analysis of triplicate samples provides for the overall
precision measurements that are necessary to determine
whether the difference is significant at the chosen confidence
level. The analysis of the surrogate spike will determine if the
analytical method performance is consistent (relatively
accurate). The method blank will show if laboratory
contamination has had an impact on the analytical results.
Selection of appropriate surrogate compounds will depend
on the target compounds identified in the soil and the
analytical methods selected for the analysis.
TREATABILITY DATA INTERPRETATION
The information and results gathered from the remedy
screening are used to determine if soil washing is a viable
treatment option and to determine if additional remedy
selection and remedy design studies are warranted. A
reduction of approximately 50 percent of the soil contaminants
during the test indicates additional treatability studies are
warranted. Contaminant concentrations can also be
determined for wash water and fine soil fractions. These
additional analyses add to the cost of the treatability test and
may not be needed. Before and after concentrations can
normally be based on duplicate samples at each period. The
mean values are compared to assess the success of the
study. If the remedy screening indicates that soil washing is
a potential cleanup option then remedy selection studies
should be performed.
In remedy selection treatability studies, soil contaminant
concentrations before soil washing and contaminant
concentrations in the coarse fraction after soil washing are
typically measured in triplicate. A reduction of approximately
90 percent in the mean concentration indicates soil washing
is potentially useful in site remediation. A number of other
factors must be evaluated before deciding to proceed to
remedy design studies.
The final concentration of contaminants in the recovered
(clean) soil fraction, in the fine soil fraction and wastewater
treatment sludge, and in the wash water are important to
evaluating the feasibility of soil washing. The selection of
technologies to treat the fine soil and wash water
wastestreams depends upon the types and concentrations of
contaminants present. The amount of volume reduction
achieved is also important to the selection of soil washing as
a potential remediation technology.
TECHNICAL ASSISTANCE
Literature information and consultation with experts are
critical factors in determining the need for and ensuring the
usefulness of treatability studies. A reference list of sources on
treatability studies is provided in the "Guide for Conducting
Treatability Studies Under CERCLA" (EPA/540/2-89/058).
It is recommended that a Technical Advisory Committee
(TAG) be used. This committee includes experts on the
technology who provide technical support from the scoping
phase of the treatability study through data evaluation.
Members of the TAG may include representatives from EPA
(Region and/or ORD), other Federal Agencies, States, and
consulting firms.
OSWER/ORD operate the Technical Support Project
(TSP) which provides assistance in the planning, performance,
and/or review of treatability studies. For further information on
treatability study support or the TSP, please contact:
Groundwater Fate and Transport Technical
Support Center
Robert S. Kerr Environmental Research Laboratory
(RSKERL), Ada, OK
Contact: Don Draper
FTS 743-2200 or (405) 332-8800
Engineering Technical Support Center
Risk Reduction Engineering Laboratory (RREL),
Cincinnati, OH
Contact: Ben Blaney
FTS 684-7406 or (513) 569-7406
FOR FURTHER INFORMATION
In addition to the contacts identified above, the
appropriate Regional Coordinator for each Region located in
the Hazardous Site Control Division/Office of Emergency and
Remedial Response or the CERCLA Enforcement
Division/Office of Waste Programs Enforcement should be
contacted for additional information or assistance.
ACKNOWLEDGEMENTS
The fact sheet and the corresponding guidance document
were prepared for the U.S. Environmental Protection Agency,
Office of Research and Development (ORD), Risk Reduction
Engineering Laboratory (RREL, Cincinnati, Ohio, by Science
Applications International Corporation (SAIC) under Contract
No. 68-C8-0061. Mr. Mike Borst and Ms. Malvina Wilkens
served as the EPA Technical Project Monitors. Mr. Jim Rawe
and Dr. Thomas Fogg served as SAIC's Work Assignment
Managers. The project team included Kathleen Hurley, Curtis
Schmidt, Cynthia Eghbalnia, and Yueh Chuang of SAIC; Pat
Esposito of Bruck, Hartman & Esposito, Inc.; James Nash of
Chapman, Inc. Mr. Clyde Dial served as SAIC's Senior
Reviewer.
Many other Agency and independent reviewers have
contributed their time and comments by participating in the
expert review meetings and/or peer reviewing the guidance
document.
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