EPA 540-2-91-021
xvEPA
United States
irwironmertsl Protection
Agency
Office of Emergency and
Remedial Response
Washington, DC 20460
Office of
Research and Development
Cincinnati, OH 45268
Superfund
EPA/540/2-91/021
October 1991
Engineering Bulletin
In Situ Soil Flushing
Purpose
Section 121(b) of the Comprehensive Environmental Re-
sponse, Compensation, and Liability Act (CERCLA) mandates
the Environmental Protection Agency (EPA) to select remedies
that "utilize permanent solutions and alternative treatment
technologies or resource recovery technologies to the maxi-
mum extent practicable" and to prefer remedial actions in
which treatment "permanently and significantly reduces the
volume, toxicity, or mobility of hazardous substances, pollut-
ants, and contaminants as a principal element." The Engineer-
ing Bulletins are a series of documents that summarize the latest
information available on selected treatment and site remediation
technologies and related issues. They provide summaries of
and references for the latest information to help remedial project
managers, on-scene coordinators, contractors, and other site
cleanup managers understand the type of data and site char-
acteristics needed to evaluate a technology for potential appli-
cability to their Superfund or other hazardous waste site. Those
documents that describe individual treatment technologies fo-
cus on remedial investigation scoping needs. Addenda will be
issued periodically to update the original bulletins.
Abstract
In situ soil flushing is the extraction of contaminants from
the soil with water or other suitable aqueous solutions. Soil
flushing is accomplished by passing the extraction fluid through
in-place soils using an injection or infiltration process. Extraction
fluids must be recovered and, when possible, are recycled. The
method is potentially applicable to all types of soil contami-
nants. Soil flushing enables removal of contaminants from the
soil and is most effective in permeable soils. An effective
collection system is required to prevent migration of contami-
nants and potentially toxic extraction fluids to uncontaminated
areas of the aquifer. Soil flushing, in conjunction with in situ
bioremediation, may be a cost-effective means of soil remedia-
tion at certain sites [1, p. vi] [2, p. 11].* Typically, soil flushing
is used in conjunction with other treatments that destroy con-
taminants or remove them from the extraction fluid and
groundwater.
Soil flushing is a developing technology that has had lim-
ited use in the United States. Typically, laboratory and field
treatability studies must be performed under site-specific condi-
tions before soil flushing is selected as the remedy of choice. To
* [reference number, page number]
date, the technology has been selected as part of the source
control remedy at 12 Superfund sites. This technology is
currently operational at only one Superfund site; a second is
scheduled to begin operation in 1991 [3][4]. EPA completed
construction of a mobile soil-flushing system, the In Situ
Contaminant/Treatment Unit, in 1988. This mobile soil-flush-
ing system is designed for use at spills and uncontrolled hazard-
ous waste sites [5].
This bulletin provides information on the technology appli-
cability, the technology limitations, a description of the tech-
nology, the types of residuals resulting from the use of the
technology, site requirements, the latest performance data, the
status of the technology, and sources of further information.
Technology Applicability
In situ soil flushing is generally used in conjunction with
other treatment technologies such as activated carbon, biodeg-
radation, or chemical precipitation to treat contaminated
groundwater resulting from soil flushing. In some cases, the
process can reduce contaminant concentrations in the soil to
acceptable levels, and thus serve as the only soil treatment
technology. In other cases, in situ biodegradation or other in
situ technologies can be used in conjunction with soil flushing
to achieve acceptable contaminant removal efficiencies. In
general, soil flushing is effective on coarse sand and gravel
contaminated with a wide range of organic, inorganic, and
reactive contaminants. Soils containing a large amount of clay
and silt may not respond well to soil flushing, especially if it is
applied as a stand-alone technology.
A number of chemical contaminants can be removed from
soils using soil flushing. Removal efficiencies depend on the
type of contaminant as well as the type of soil. Soluble (hydro-
philic) organic contaminants often are easily removed from soil
by flushing with water alone. Typically, organics with octanol/
water partition coefficients (Kow) of less than 10 (log Kow<1) are
highly soluble. Examples of such compounds include lower
molecular weight alcohols, phenols, and carboxylic acids [6].
Low solubility (hydrophobic) organics may be removed by
selection of a compatible surfactant [7]. Examples of such
compounds include chlorinated pesticides, polychlorinated bi-
phenyls (PCBs), semivolatiles (chlorinated benzenes and poly-
nuclear aromatic hydrocarbons), petroleum products (gasoline,
-------
jet fuel, kerosene, oils and greases), chlorinated solvents
(trichloroethene), and aromatic solvents (benzene, toluene, xy-
lenes and ethylbenzene) [8]. However, removal of some of
these chemical classes has not yet been demonstrated.
Metals may require acids, chelating agents, or reducing
agents for successful soil flushing. In some cases, all three types
of chemicals may be used in sequence to improve the removal
efficiency of metals [9]. Many inorganic metal salts, such as
carbonates of nickel, zinc, and copper, can be flushed from the
soil with dilute acid solutions [6]. Some inorganic salts such as
sulfates and chlorides can be flushed with water alone.
In situ soil flushing has been considered for treating soils
contaminated with hazardous wastes, including pentachloro-
phenol and creosote from wood-preserving operations, organic
solvents, cyanides and heavy metals from electroplating resi-
dues, heavy metals from some paint sludges, organic chemical
production residues, pesticides and pesticide production resi-
dues, and petroleum/oil residues [10, p. 13][11, p. 8][7][12].
The effectiveness of soil flushing for general contaminant
groups [10, p. 13] is shown in Table 1. Examples of constitu-
ents within contaminant groups are provided in Reference 10,
"Technology Screening Guide For Treatment of CERCLA Soils
and Sludges." Table 1 is based on currently available informa-
tion or professional judgment where definitive information is
Table 1
Effectiveness of Soil Flushing on General
Contaminant Groups
Contaminant Croups
Halogenated volatile*
Halogenated semivolatiles
Nonhalogenated volatiles
Nonhalogenated semivolatiles
PCBs
Pesticides (halogenated)
Dioxins/Furans
Organic cyanides
Organic corrosives
Effectiveness
Volatile metals
Nonvolatile metals
Asbestos
Radioactive materials
Inorganic corrosives
Inorganic cyanides
V
T
•
T
T
V
T
T
Oxidizers
Reducers
• Demonstrated Effectiveness: Successful treatability test at some scale
completed.
T Potential Effectiveness: Expert opinion that technology will work.
J No Expected Effectiveness: Expert opinion that technology will not work.
currently inadequate or unavailable. The demonstrated effec-
tiveness of the technology for a particular site or waste does not
ensure that it will be effective at all sites or that the treatment
efficiency achieved will be acceptable at other sites. For the
ratings used in this table, demonstrated effectiveness means
that, at some scale, treatability was tested to show that, for that
particular contaminant and matrix, the technology was effec-
tive. The ratings of potential effectiveness and no expected
effectiveness are based upon expert judgment. Where poten-
tial effectiveness is indicated, the technology is believed capable
of successfully treating the contaminant group in a particular
matrix. When the technology is not applicable or will probably
not work for a particular combination of contaminant group
and matrix, a no-expected-effectiveness rating is given. Other
sources of general observations and average removal efficien-
cies for different treatability groups are the Superfund LDR
Guide #6A, "Obtaining a Soil and Debris Treatability Variance
for Remedial Actions" (OSWER Directive 9347.3-06FS) [13],
and Superfund LDR Guide #6B, "Obtaining a Soil and Debris
Treatability Variance for Removal Actions" (OSWER Directive
9347.3-07FS)[14].
Information on cleanup objectives, as well as the physical
and chemical characteristics of the site soil and its contami-
nants, is necessary to determine the potential performance of
this technology. Treatability tests are also required to determine
the feasibility of the specific soil-flushing process being consid-
ered. If bench-test results are promising, pilot-scale demonstra-
tions should be conducted before making a final commitment
to full-scale implementation. Table 2 contains physical and
chemical soil characterization parameters that should be estab-
lished before a treatability test is conducted at a specific site.
The table contains comments relating to the purpose of the
specific parameter to be characterized and its impact on the
process [15, p. 71 5] [16, p. 90] [1 7].
Soil permeability is a key physical parameter for determin-
ing the feasibility of using a soil-flushing process. Hydraulic
conductivity (K) is measured to assess the permeability of soils.
Soils with low permeability (K < 1.0 x 10"5 cm/sec) will limit the
ability of flushing fluids to percolate through the soil in a
reasonable time frame. Soil flushing is most likely to be effective
in permeable soils (K > 1.0 x 103 cm/sec), but may have limited
application to less permeable soils (1.0 x 10"5 cm/sec < K < 1.0 x
10'3 cm/sec). Since there can be significant lateral and vertical
variability in soil permeability, it is important that field measure-
ments be made using the appropriate methods.
Prior to field implementation of soil flushing, a thorough
groundwater hydrologic study should be carried out. This
should include information on seasonal fluctuations in water
level, direction of groundwater flow, porosity, vertical and hori-
zontal hydraulic conductivities, transmissivity and infiltration
(data on rainfall, evaporation, and percolation).
Moisture content can affect the amount of flushing fluids
required. Dry soils will require more flushing fluid initially to
mobilize contaminants. Moisture content is also used to calcu-
late pore volume to determine the rate of treatment [15].
The concentration and distribution of organic contami-
Engineering Bulletin: In Situ Soil Flushing
-------
Table 2
Characterization Parameters
Parameter
Soil permeability
>1.0x 10'3 cm/sec
<1.0x 10s cm/sec
Soil structure
Soil porosity
Moisture content
Groundwater hydrology
Organics
Concentration
Solubility
Partition
coefficient
Metals
Concentration
Solubility products
Reduction potential
Complex stability
constants
Total Organic Carbon
(TOC)
Clay content
Cation Exchange
Capacity (CEC)
pH, buffering
capacity
Purpose and Comment
Affects treatment time and
efficiency of contaminant removal l
Effective soil flushing
Limited soil flushing
Influences flow patterns
(channeling, blockage)
Determines moisture capacity of soil
at saturation (pore volume)
Affects flushing fluid transfer
requirements
Critical in controlling the recovery
of injected fluids and contaminants
Determine contaminants and
assess flushing fluids required,
flushing fluid compatibility,
changes in flushing fluid with
changes in contaminants.
Concentration and species of cons-
tituents will determine flushing fluid
compatibility, mobility of metals,
post treatment.
Adsorption of contaminants on
soil increases with increasing TOC.
Important in marine wetland sites,
which typically have high TOC.
Adsorption of contaminants on soil
increases with increasing clay
content.
May affect treatment of metallic
compounds.
May affect treatment additives
required, compatibility with
equipment materials of construc-
tion, wash fluid compatibility.
nants and metals are key chemical parameters. These param-
eters determine the type and quantity of flushing fluid required
as well as any post-treatment requirements. The solubility and
partition coefficients of organics in water or other solutions are
also important in the selection of the proper flushing fluids.
The species of metal compounds present will affect the solubil-
ity and leachability of heavy metals.
High humic content and high cation exchange capacity
tend to reduce the removal efficiency of soil flushing. Some
organic contaminants may adsorb to humic materials or clays
in soils and, therefore, are difficult to remove during soil flush-
ing. Similarly, the binding of certain metals with clays due to
cationic exchange makes them difficult to remove with soil
flushing. The buffering capacity of the soil will affect the
amount required of some additives, especially acids. Precipita-
tion reactions (resulting in clogging of soil pores) can occur due
to pH changes in the flushing fluid caused by the neutralizing
effect of soils with high buffering capacity. Soil pH can affect
the speciation of metal compounds resulting in changes in the
solubility of metal compounds in the flushing fluid.
Limitations
Generally, remediation times with this technology will be
lengthy (one to many years) due to the slowness of diffusion
processes in the liquid phase. This technology requires hydrau-
lic control to avoid movement of contaminants offsite. The
hydrogeology of some sites may make this difficult or impos-
sible to achieve.
Contaminants in soils containing a high percentage of silt-
and clay-sized particles typically are strongly adsorbed and
difficult to remove. Also, soils with silt and clay tend to be less
permeable. In such cases, soil flushing generally should not be
considered as a stand-alone technology.
Hydrophobic contaminants generally require surfactants
or organic solvents for their removal from soil. Complex mix-
tures of contaminants in the soil (such as a mixture of metals,
nonvolatile organics, and semivolatile organics) make it difficult
to formulate
-------
Technology Description
Figure 1 is a general schematic of the soil flushing process [18, p.
7]. The flushing fluid is applied (1) to the contaminated soil by
subsurface injection wells, shallow infiltration galleries, surface flood-
ing, or above-ground sprayers. The flushing fluid is typically water
and may contain additives to improve contaminant removal.
The flushing fluid percolates through the contaminated soil,
removing contaminants as it proceeds. Contaminants are mobi-
lized by solubilization into the flushing fluid, formation of emul-
sions, or through chemical reactions with the flushing fluid [19].
Contaminated flushing fluid or leachate mixes with ground-
water and is collected (2) for treatment. The flushing fluid
delivery and the groundwater extraction systems are designed
to ensure complete contaminant recovery [7]. Ditches open to
the surface, subsurface collection drains, or groundwater recov-
ery wells may be used to collect flushing fluids and mobilized
contaminants. Proper design of a fluid recovery system is very
important to the effective application of soil flushing.
Contaminated groundwater and flushing fluids are cap-
tured and pumped to the surface in a standard groundwater
extraction well (3). The rate of groundwater withdrawal is
determined by the flushing fluid delivery rate, the natural infil-
tration rate, and the groundwater hydrology. These will deter-
mine the extent to which the groundwater removal rate must
exceed the flushing fluid delivery rate to ensure recovery of all
reagents and mobilized contaminants. The system must be
designed so that hydraulic control is maintained.
The groundwater and flushing fluid are treated (4) using
the appropriate wastewater treatment methods. Extracted
groundwater is treated to reduce the heavy metal content,
organics, total suspended solids, and other parameters until
they meet regulatory requirements. Metals may be removed
by lime precipitation or by other technologies compatible with
the flushing reagents used. Organics are removed with acti-
vated carbon, air stripping, or other appropriate technologies.
Whenever possible, treated water should be recycled as makeup
water at the front end of the soil-flushing process.
Flushing additives (5) are added, as required, to the
treated groundwater, which is recycled for use as flushing
fluid. Water alone is used to remove hydrophilic organics and
soluble heavy-melal salts [9]. Surfactants may be added to
remove hydrophobic and slightly hydrophilic organic con-
taminants [12]. Chelating agents, such as ethylene-
diaminetetra-acetic acid (EDTA), can effectively remove cer-
tain metal compounds. Alkaline buffers such as tetrasodium
pyrophosphate can remove metals bound to the soil organic
fraction. Reducing agents such as hydroxylamine hydrochlo-
ride can reduce iron and manganese oxides that can bind
Figure 1
Schematic of Soil Flushing System
Spray Application
(V
Pump
Flushing
Additives
(5)
Groundwater
Treatment
(4)
Pump
Contaminated Area
Groundwater
Extraction Well
(3)
Vadose
Zone
Leachate
Collection
(2)
Groundwater
Zone
Low Permeability
Zone
Engineering Bulletin: In Situ Soil Flushing
-------
metals in soil. Insoluble heavy-metal compounds also can be
reduced or oxidized to more soluble compounds. Weak acid
solutions can improve the solubility of certain heavy metals
[9]. Treatability studies should be conducted to determine
compatability of the flushing reagents with the contaminants
and with the site soils.
Process Residuals
The primary waste stream generated is contaminated flush-
ing fluid, which is recovered along with groundwater. Recov-
ered flushing fluids may need treatment to meet appropriate
discharge standards prior to release to a local, publicly-owned
wastewater treatment works or receiving streams. To the maxi-
mum extent practical, this water should be recovered and
reused in the flushing process. The separation of surfactants
from recovered flushing fluid, for reuse in the process, is a major
factor in the cost of soil flushing. Treatment of the flushing fluid
results in process sludges and residual solids, such as spent
carbon and spent ion exchange resin, which must be appropri-
ately treated before disposal. Air emissions of volatile contami-
nants from recovered flushing fluids should be collected and
treated, as appropriate, to meet applicable regulatory standards.
Residual flushing additives in the soil may be a concern and
should be evaluated on a site-specific basis.
Site Requirements
Access roads are required for transport of vehicles to and
from the site. Stationary or mobile soil-flushing process systems
are located on site. The exact area required will depend on the
vendor system selected and the number of tanks or ponds
needed for washwater preparation and wastewater treatment.
Because contaminated flushing fluids are usually consid-
ered hazardous, their handling requires that a site safety plan be
developed to provide for personnel protection and special han-
dling measures during wastewater treatment operations. Fire
hazard and explosion considerations should be minimal, since
the soil-flushing fluid is predominantly water.
An Underground Injection Control (DIG) Permit may be
necessary if subsurface infiltration galleries or injection wells are
used. When groundwater is not recycled, a National Pollution
Discharge Elimination System (NPDES) or State Pollution Dis-
charge Elimination System (SPDES) permit may be required.
Federal, State, and local regulatory agencies should be con-
tacted to determine permitting requirements before imple-
menting this technology.
Slurry walls or other containment structures may be needed
along with hydraulic controls to ensure capture of contaminants
and flushing additives. Climatic conditions such as precipitation
cause surface runoff and water infiltration. Berms, dikes, or other
runoff control methods may be required. Impermeable mem-
branes may be necessary to limit infiltration of precipitation,
which could cause dilution of flushing solution and loss of hy-
draulic control. Cold weather freezing must also be considered
for shallow infiltration galleries and above-ground sprayers.
Performance Data
Some of the data presented for specific contaminant re-
moval effectiveness were obtained from publications devel-
oped by the respective soil-flushing-system vendors. The qual-
ity of this information has not been determined; however it
does give an indication of the effectiveness of in situ soil
flushing.
Tetrachloroethylene was discharged into the aquifer at the
site of a spill in Sindelfingen, Germany. The contaminated
aquifer is a high-permeability (k=5.10 x 10"4 m/sec) layer over-
laying a clay barrier. Soil flushing was accomplished by infiltrat-
ing water into the ground through ditches. The leaching liquid
and polluted groundwater were pumped out of eight wells and
treated with activated carbon. The treated water was recycled
through the infiltration ditches. Within 18 months, 17 metric
tons of chlorinated hydrocarbons were recovered [19, p. 565].
Two percolation basins were installed to flush contami-
nated soil at the United Chrome Products site near Corvallis,
Oregon. Approximately 1,100 tons of soil containing the
highest chromium concentrations were excavated and dis-
posed of offsite. The resulting pits from the excavations were
used as infiltration basins to flush the remaining contaminated
soil. The soil-flushing operation for the removal of hexavalent
chromium from an estimated 2.4 million gallons of contami-
nated groundwater began in August 1988. No information on
the site soils was provided, but preliminary estimates were that
a groundwater equilibrium concentration of 100 mg/L chromium
would be reached in 1 to 2 years, but that final cleanup to 10
mg/L would take up to 25 years [20, p. H-1 ]. Since that time
over 8-million gallons of groundwater, containing over 25,000
pounds of chromium, have been removed from the 23 extrac-
tion wells in the shallow aquifer. Average monthly chromium
concentrations in the groundwater decreased from 1,923 mg/
L in August 1988 to 96 mg/L in March 1991 [4].
Waste-Tech Services, Inc. performed two tests of soil-
flushing techniques to remove creosote contamination at the
Laramie Tie Plant site in Wyoming. The first test involved slowly
flooding the soil surface with water to perform primary oil
recovery (POR). Soil flushing reduced the average concentra-
tion of total extractable organics (TEO) from an estimated
initial concentration of 93,000 mg/kg to 24,500 mg/kg, a 74
percent reduction. The second test involved sequential treat-
ment with alkaline agents, polymers, and surfactants. During
the 8-month treatment period, average TEO concentrations
were reduced to 4,000 mg/kg. This represents an 84 percent
reduction from the post-POR concentration (24,500 mg/kg)
and a 96 percent reduction from the estimated initial concen-
tration (93,000 mg/kg). The tests were performed in alluvial
sands and gravels. The low permeability of adjacent silts and
clays precluded soii flushing [22].
Laboratory tests were conducted on contaminated soils
from a fire-training area at Volk Air Force Base. Initial
concentrations of oil and grease in the soils were reported to be
10,000 and 6,000 mg/kg. A 1.5-percent surfactant solution in
water was used to flush soil columns. The tests indicated that
75 to 94 percent of the initial hydrocarbon contamination
could be removed by flushing with 12-pore volumes of liquid.
Engineering Bulletin: In Situ Soil Flushing
-------
However, field tests were unsuccessful in removing the same
contaminants. Seven soil-flushing solutions, including the solu-
tion tested in the laboratory studies, were tested in field studies.
The flushing solutions were delivered to field test cells measur-
ing 1 foot deep and 1 to 2 feet square. Only three of the seven
tests achieved the target delivery of 14-pore volumes. Two of
the test cells plugged completely, permitting no further infiltra-
tion of flushing solutions. There was no statistically significant
removal of soil contaminants due to soil flushing. The plugging
of test cells may be related to the use of a surfactant solution.
By hydrolyzing in water, surfactants may block soil pores by
forming either floes or surfactant aggregates called micelles. In
addition, if the surfactant causes fine soil particles to become
suspended in the flushing fluid, narrow passages between soil
particles could be blocked. If enough of these narrow passages
are blocked along a continuous front, a "mat" is said to have
formed, and fluid flow is halted in that area [23] [7].
Resource Conservation Recovery Act (RCRA) Land Dis-
posal Restrictions (LDRs) that require treatment of wastes to
best demonstrated available technology (BOAT) levels prior to
land disposal may sometimes be determined to be applicable
or relevant and appropriate requirements (ARARs) for CERCLA
response actions. The soil-flushing technology can produce a
treated waste that meets treatment levels set by BOAT, but
may not reach these treatment levels in all cases. The ability
of the technology to meet required treatment levels is depen-
dent upon the specific waste constituents and the waste
matrix. In cases where soil flushing does not meet these
levels, it still may, in certain situations, be selected for use at
the site if a treatability variance establishing alternative treat-
ment levels is obtained. EPA has made the treatability vari-
ance process available in order to ensure that LDRs do not
unnecessarily restrict the use of alternative and innovative
treatment technologies. Treatability variances may be justi-
fied for handling complex soil and debris matrices. The
following guides describe when and how to seek a treatability
variance for soil and debris: Superfund LDR Guide #6A,
"Obtaining a Soil and Debris Treatability Variance for Reme-
dial Actions" (OSWER Directive 9347.3-06FS) [1 3], and Super-
fund LDR Guide #6B, "Obtaining a Soil and Debris Treatability
Variance for Removal Actions" (OSWER Directive 9347.3-07FS)
[14], Another approach could be to use other treatment
techniques in conjunction with soil flushing to obtain desired
treatment levels.
Technology Status
In situ soil flushing is a developing technology that has had
limited application in the United States. In situ soil flushing
technology has been selected as one of the source control
remedies at the 12 Superfund sites listed in Table 3 [3].
EPA Contact
Technology-specific questions regarding soil flushing may
be directed to:
Michael Gruenfeld
U.S. EPA, Releases Control Branch
Risk Reduction Engineering Laboratory
2890 Woodbndge Avenue, Building 10
Edison, New Jersey 08837
Telephone FTS 340-6625 or (908) 321-6625.
Table 3
Superfund Sites Using In Situ Soil Flushing
Site
Byron Barrel & Drum
Goose Farm
Lipari Landfill
Vineland Chemical
Harvey-Knott Drum
L.A. Clarke St Son
Ninth Avenue Dump
U.S. Aviex
South Calvacale Street
United Chrome Products
Cross Brothers Pail
Bog Creek Farm
Location (Region)
Genesee County, NY (2)
Plumsted Township, NJ (2)
Gloucester, N| (2)
Vineland, NJ (2)
J DE(3)
Spotsylvania, VA (3)
Garry, IN (5)
Miles, Ml (5)
Houston, TX (6)
Corvallis, OR (10)
Pembroke, IL (5)
Howell Township, N| (2)
Primary Contaminants
VOCs (BTX, PCE, and TCE)
VOCs (Toluene, Ethylbenzene,
Dichloromethane, and TCE), SVOCs, and PAHs
VOCs (Benzene, Ethylbenzene, Dichlormethane,
and TCE), SVOCs, PAHs and Chlorinated ethers
(bis-2-chloroethylether)
Arsenic and VOCs (Dichloromethane)
Lead
Creosote, PAHs, and Benzene
VOCs (BTEX, TCE), PAHs, Phenols, Lead, I'CBs,
and Total Metals
VOCs (Carbon Tetrachloride, DCA,
Ethylbenzene, PCE, TCE, Toluene, TCA, Freon,
Xylene, and Chloroform)
PAHs
Chromium
VOCs (Benzene, PCE, TCE, Toluene, and
Xylenes) and PCBs
VOCs, Organics
Status
Pre-design: finalizing workplan
In design: 30% design phase
Operational, summer '91
Pre-design
In design: re-evaluating alternative
In design
In design: pilot failed
Pre-design: re-evaluating alternatives
In design
Operational since 8/88
In desgn: developing workplan
In design: treatment plant completed,
dump and treat not installed
Engineering Bulletin: In Situ Soil Flushing
-------
Acknowledgments
This bulletin was prepared for the U.S. Environmental Protec-
tion Agency, Office of Research and Development (ORD), Risk
Reduction Engineering Laboratory (RREL), Cincinnati, Ohio, by
Science Applications International Corporation (SAIC) under con-
tract No. 68-C8-0062. Mr. Eugene Harris served as the EPA
Technical Project Monitor. Mr. Gary Baker was SAIC's Work As-
signment Manager. This bulletin was authored by Mr. Jim Rawe of
SAIC. The author is especially grateful to Ms. Joyce Perdek of EPA,
RREL, who has contributed significantly by serving as a technical
reviewer during the development of this document.
The following other Agency and contractor personnel have
contributed their time and comments by participating in the
expert review meeting and/or peer reviewing the document:
Mr. Benjamin Blaney
Ms. Sally Clement
Mr. Clyde Dial
Ms. Linda Fiedler
Dr. David Wilson
EPA-RREL
Bruck, Hartman and Esposito
SAIC
EPA-TIO
Vanderbilt University
Ms. Tish Zimmerman EPA-OSWER
REFERENCES
1. Handbook: In Situ Treatment of Hazardous Waste-
Contaminated Soils. EPA/540/2-90/002, U.S. Environ-
mental Protection Agency, 1990.
2. A Compendium of Technologies Used in the Treatment
of Hazardous Wastes. EPA/625/8-87/014, U.S. Environ-
mental Protection Agency, 1987.
3. Innovative Treatment Technologies: Semi-Annual Status
Report. EPA/540/2-91/001, U.S. Environmental Protec-
tion Agency, 1991.
4. Personal communications of SAIC staff with RPMs, 1991.
5. In Situ Containment/Treatment System, Fact Sheet. U.S.
Environmental Protection Agency, 1988.
6. Sanning, D. E., et. al. Technologies for In Situ Treatment
of Hazardous Wastes, EPA/600/D-87/014, U.S. Environ-
mental Protection Agency, 1987.
7. Nash, J. and R.P. Traver. Field Evaluation of In Situ
Washing of Contaminated Soils With Water/Surfactants.
Overview-Soils Washing Technologies For: Comprehen-
sive Environmental Response, Compensation, and Liability
Act, Resource Conservation and Recovery Act, Leaking
Underground Storage Tanks, Site Remediation, U.S.
Environmental Protection Agency, 1989. pp. 383-392.
8. Wilson, D.)., et. al., Soil Washing and Flushing With
Surfactants. Tennessee Water Resources Research Center.
September, 1990.
9. Ellis, W.D., T.R. Fogg and A.N. Tafuri. Treatment of Soils
Contaminated With Heavy Metals. Overview-Soils
Washing Technologies For: Comprehensive Environmen-
tal Response, Compensation, and Liability Act, Resource
Conservation and Recovery Act, Leaking Underground
Storage Tanks, Site Remediation, U.S. Environmental
Protection Agency, 1989. pp. 127-134.
10. Technology Screening Guide for Treatment of CERCLA
Soils and Sludges. EPA/540/2-88/004, U.S. Environmen-
tal Protection Agency, 1988.
11. Nunno, T.J., j.A. Hyman, and T. Pheiffer. Development of
Site Remediation Technologies in European Countries.
Presented at Workshop on the Extractive Treatment of
Excavated Soil. U.S. Environmental Protection Agency,
Edison, New |ersey, 1988.
12. Ellis, W.D., J.R. Payne, and G.D. McNabb, Project
Summary: Treatment of Contaminated Soils with
Aqueous Surfactants. EPA/600/S2-85/129, U.S. Environ-
mental Protection Agency, 1985.
13. Superfund LDR Guide #6A: Obtaining a Soil and Debris
Treatability Variance for Remedial Actions. OSWER
Directive 9347.3-06FS, U.S. Environmental Protection
Agency, 1989.
14. Superfund LDR Guide #6B: Obtaining a Soil and Debris
Treatability Variance for Removal Actions. OSWER
Directive 9347.3-07FS, U.S. Environmental Protection
Agency, 1989.
15. Sims, R.C Soil Remediation Techniques at Uncontrolled
Hazardous Waste Sites, A Critical Review. Air & Waste
Management Association, 1990.
16. Guide for Conducting Treatability Studies Under CERCLA,
Interim Final. EPA/540/2-89/058, U.S. Environmental
Protection Agency, 1989.
17. Connick, C.C. Mitigation of Heavy Metal Migration in
Soil. Overview-Soils Washing Technologies For: Compre-
hensive Environmental Response, Compensation, and
Liability Act, Resource Conservation and Recovery Act,
Leaking Underground Storage Tanks, Site Remediation,
U.S. Environmental Protection Agency, 1989. pp. 155-
165.
Engineering Bulletin: In Situ Soil Flushing
-------
18. Handbook: Remedial Action at Waste Disposal Sites
(Revised). EPA/625/6-85/006. U.S. Environmental
Protection Agency, 1985.
19. Stief, K. Remedial Action for Groundwater Protection
Case Studies Within the Federal Republic of Germany.
Presented at the 5th National Conference on Manage-
ment of Uncontrolled Hazardous Waste Sites.
Washington, DC., 1984.
20. Young, C, et. al. Innovative Operational Treatment
Technologies for Application to Superfund Site - Nine
Case Studies, Final Report. EPA 540/2-90/006, U.S.
Environmental Protection Agency, 1990.
21. United Chrome Groundwater Extraction and Treatment
Facility. Monthly Report - March 1991. U.S. Environ-
mental Protection Agency, Region 10, 1991.
22. Marketing Brochure, Waste-Tech Services, Inc., Waste
Minimization Division, 1990.
23. Sale, T. and M. Pitts. Chemically Enhanced In Situ Soil
Washing. Proceedings of the Conference on Petroleum
Hydrocarbons and Organic Chemicals in Ground Water:
Prevention, Detection and Restoration. National Water
Well Association, 1989.
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati, OH 45268
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use $300
------- |