&EPA
United States
Environmental Protection
Agency
SITE Technology Capsule
Demonstration of Rocky
Mountain Remediation
Services Soil Amendment
Process
Abstract
RMRS developed the Envirobond™ process to treat heavy
metals in soil.This phosphate-based technology consists of
a proprietary powder and solution that binds with metals in
contaminated waste. RMRS claims that the Envirobond™
process converts metal contaminants from their leachable
form to a stable, nonhazardous one.
The EPA SITE Program evaluated a pilot-scale application
of the Envirobond™ process at two locations in September
1998.The Envirobond™ process was applied to the soil sur-
face and tilled 6 inches into the lead-contaminated soil.
Personnel used the Toxicity Characteristic Leaching Proce-
dure (TCLP) to analyze treated and untreated soil samples
for lead and a method forbioavailable lead to support two pri-
mary objectives. Primary objective 1 (P1) evaluated whether
Envirobond™ can treat lead-contaminated soil to meet the
Resource Conservation and Recovery Act (RCRA)/Hazard-
ous and Solid Waste Amendments (HSWA) alternative uni-
versal treatment standards (UTS) for land disposal of
lead-contaminated soils. The alternative UTS for soil con-
taminated with lead is determined from the results of the
TCLP. The alternative UTS is met if the concentration of lead
in theTCLP extract is no higherthan one of these: (1) 7.5 mil-
ligrams per liter (mg/L), or (2) 10 percent of the lead concen-
tration in the TCLP extract from the untreated soil.
Contaminated soils with TCLP lead concentrations below the
alternative UTS meet the RCRA land disposal restrictions
(LDR), and are eligible for disposal in a land-based RCRA
hazardous waste disposal unit. The alternative UTS is de-
fined further under Title 40 of the Code of Federal Regula-
tions (CFR), Chapter I, part 268.49 (40 CFR 268.49).To meet
that objective, soil samples were collected before and after
the application of Envirobond™.The soil samples were ana-
lyzed for TCLP lead concentrations to judge whether the
technology met objective P1. Analysis of the data showed
Envirobond™ reduced the mean TCLP lead concentration
at the inactive pottery factory from 382 mg/L to 1.4 mg/L. The
treated soil meets the alternative UTS for soil at the inactive
pottery factory. Data from the trailer park were not used to
evaluate P1 because TCLP lead concentrations in all treated
and untreated soil samples from this location were either at
or slightly higherthan the detection limit of 0.05 mg/L.
In primary objective 2 (P2), staff evaluated whether
Envirobond™ decreased soil lead bioaccessibility by 25
percent or more, as defined by the Solubility/Bioaccessibility
Research Consortium's (SBRC) Simplified In-Vitro Test
Method for Determining Soil Lead and Arsenic
Bioaccessibility (simplified in vitro method [SIVM]). EPA Lead
Sites Workgroup (LSW) and Technical Review Workgroup for
lead (TRW) do not endorse an in-vitro test for finding soil lead
bioaccessibility (Interstate Technology and Regulatory Co-
operation [ITRC] 1997). To meet objective P2, personnel
collected soil samples before and after applying
Envirobond™. They analyzed soil samples for soil lead
bioaccessibility to find whether the technology met objective
P2. Analyzing data showed that Envirobond™ reduced the
soil lead bioaccessibility by about 12.1 percent, which is less
than the project goal of at least a 25 percent reduction in soil
lead bioaccessibility.
The staff examined 12 cost categories fora plan in which the
Envirobond™ process was applied at full scale to treat lead-
contaminated soil at a Superfund site. The cost estimate
assumed the size of the site was 1 acre, and that the treat-
ment was applied to a depth of 6 inches, which results in an
estimated treated volume of about 807 cubic yards. The es-
timate assumes the site's soil characteristics and lead con-
centrations were similarto those of the CRPAC evaluation.
Based on these assumptions, the total costs would be
$33,220, which is $41.16 per cubic yard of soil treated. Costs
for applying the Envirobond™ process may vary.
The Envirobond™ process evaluation was based on the nine
decision-making criteria used in the Superfund feasibility
study process. Results are summarized in Table 1.
Introduction
In 1980, the U.S. Congress passed the Comprehensive En-
vironmental Response, Compensation, and Liability Act
(CERCLA), also known as Superfund, which is committed
to protecting human health and the environment from uncon-
trolled hazardous waste sites. CERCLA was amended by the
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Table 1. Evaluation of Envirobond™ Compared to the Nine Criteria for Superfund Feasibility Studies
1.
2.
3.
4.
5.
6.
7.
8.
9.
Criterion
Overall Protection of
Human Health and the
Environment
Compliance with
Applicable or Relevant and
Appropriate Requirements
(ARARs)
Long-term Effectiveness
and Permanence
Short-term Effectiveness
Reduction of Toxicity,
Mobility, or Volume
through Treatment
Implementability
Cost
Community Acceptance
State Acceptance
Discussion
The technology is expected to significantly lower the leachability of lead from soils as
indicated by the TCLP results, thereby reducing the migration of lead to groundwater and the
potential for exposure of all receptors to lead; however, the technology did not significantly
reduce soil lead bioaccessibility, as determined by the SIVM.
During the SITE demonstration, Envirobond™ reduced the mean TCLP lead concentration
from 382 mg/L to 1 .4 mg/L, a reduction of more than 99 percent. Further, the treated TCLP
lead concentrations were less than the alternative UTS for lead in soil. Therefore, the treated
soil met the land disposal restrictions (LDR) for lead-contaminated soil, as specified in 40 CFR
268.49. However, the technology's ability to comply with existing federal, state, or local
ARARs should be determined on a site-specific basis.
The analytical results of procedures for the multiple extraction procedure (MEP), the procedure
for lead speciation by sequential extraction, the test for cation exchange capacity (CEC), and
leachable lead by the simulated precipitation leaching procedure (SPLP) suggest long-term
chemical stability of the treated soil. The analytical results of a number of other procedures do
not suggest long-term chemical stability of the treated soil. Those procedures included pH
analyses, Eh analyses, separate analyses for total lead by nitric and hydrofluoric acids; total
phosphates; and SPLP phosphates. The results related to long-term effectiveness from the test
for lead speciation by scanning electron microscopy and acid neutralization were inconclusive.
Short-term effectiveness is high; measures for dust control and surface runoff controls may be
required at some sites.
The mean TCLP lead concentration was reduced from 382 mg/L to 1 .4 mg/L, reducing the
mobility of the lead in the soil.
The technology is relatively easy to apply. Large areas can be treated using common farm
equipment, and small areas can be treated using readily available home gardening tools (sod
cutter, tiller, fertilizer sprayer)
For full-scale application of the technology at a 1-acre site contaminated with lead in the top 6
inches of soil, estimated costs are $33,220, which is $41 .16 per cubic yard.
Community acceptance of Envirobond™ likely will be a site-specific issue.
State acceptance of Envirobond™ likely will be a site-specific issue.
Superfund Amendments and Reauthorization Act (SARA) in
1986. SARA mandates implementing permanent solutions
and using alternative, innovative treatment or resource re-
covery technologies to the maximum extent possible.
State and federal agencies and private organizations are
exploring a growing number of innovative technologies for
treating hazardous wastes. These new technologies are
needed to remediate the more than 1,200 sites on the Na-
tional Priorities List. The sites involve a broad spectrum of
physical, chemical, and environmental conditions requiring
diverse remedial approaches.
The U.S. Environmental Protection Agency (EPA) is engaged
in a number of activities that are focused on exploring and
applying innovative technologies to Superfund site
remediation. One EPA initiative to accelerate the develop-
ment, evaluation, and use of innovative site remediation tech-
nologies is the Superfund Innovative Technology Evaluation
(SITE) Program. One of the goals of the SITE Program is to
disseminate information about innovative technologies to the
user community. This Technology Capsule is one of the docu-
ments the SITE Program uses to meet this goal.
EPA SITETechnology Capsules summarize the latest infor-
mation available on innovative technologies. The technology
capsules assist EPA remedial project managers, EPA on-site
coordinators, contractors, and other remedial managers in
evaluating site-specific information to determine a
technology's applicability for site remediation.
This technology capsule provides information on the Rocky
Mountain Remediation Services, L.L.C. (RMRS),
Envirobond™ process. RMRS developed the Envirobond™
process for treating heavy metals and radionuclides in soil
by reducing the contaminants' ability to leach from the soil.
The Envirobond™ process was evaluated in September
1998, at a site in southeastern Ohio.The Envirobond™ pro-
cess was applied in situ to residential and industrial soils
contaminated with lead from pottery factory waste.
This technology capsule describes Envirobond™ and sum-
marizes results from the SITE evaluation. The capsule in-
cludes the following information:
Abstract
Site Background
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Technology Description
Evaluation Activities
Technology Applicability
Performance Data
Technology Status
Sources of Further Information
Site Background
The villages of Crooksville and Roseville, located along the
Muskingum/Perry County line in southeastern Ohio, are fa-
mous for a long history of pottery production. Lead com-
pounds were used in pottery glazes until they were replaced
by low-lead or no-lead compounds in the last 20 years.
In 1996, the Ohio Environmental Protection Agency (OEPA)
entered into a cooperative agreement with the EPA to con-
duct a Geographic Initiative (Gl) of the Crooksville/Roseville
Pottery Area of Concern (CRPAC).The purpose of the inves-
tigation was to determine if the pottery operations in the
CRPAC resulted in heavy metal contamination of the soil,
groundwater, surface water, and ambient air.
Analytical results from samples collected for the Gl investi-
gation in mid-1997 identified 14 pottery waste disposal sites
with significant lead contamination in shallow soil. OEPA is
seeking innovative technologies that will remediate the lead
in the soil in the CRPAC.
SITE Program personnel collected soil samples from four
sites throughout the CRPAC in May, June, and August 1998.
These samples were analyzed forTCLP lead concentrations
and relative percent bioavailable lead concentrations. The
analytical results and visual observations were used to char-
acterize soil to enable selection of the evaluation sites.
The two locations selected for the SITE demonstration were
an inactive pottery factory in Roseville, Ohio, and a trailer
park, also in Roseville. The principal reasons for the selec-
tion of the inactive pottery factory in Roseville were that it
appeared to have higher concentrations of lead than any of
the other locations and it was more readily accessible than
the other pottery factories under consideration. The trailer
park was selected for the SITE demonstration primarily be-
cause use of that site would allow evaluation of the
Envirobond™ technology at sites at which concentrations of
lead in soil were lower than those at the other sites under
consideration. At the time the selection was made, there was
some concern that the concentrations of lead at the trailer
park might be too low because they did not exceed 400 mg/
kg, the residential preliminary remediation goal (PRG) for
lead established by EPA (EPA 2000). However, previous field
sampling conducted by OEPA with X-ray fluorescence (XRF)
analyzers had indicated that total concentrations of lead in
the soil at the trailer park were well above 400 mg/kg.
Technology Description
The Envirobond™ process is a combination of a proprietary
powder and solution that binds with metals in contaminated
soils, sludges, mine tailings and process residues, and other
solid wastes.
The Envirobond™ process consists of a mixture of additives
containing oxygen, nitrogen, and phosphorous; each addi-
tive has an affinity for a specific class of metals. RMRS claims
that the Envirobond™ process converts each metal contami-
nant from its leachable form to an insoluble, stable, nonhaz-
ardous metallic complex. The Envirobond™ process is
essentially a mixture of ligands that act as chelating agents.
In the chelation reaction, coordinate bonds attach the metal
ion to at least two ligand nonmetal ions to form a heterocy-
clic ring.The resulting ring structure is inherently more stable
than simpler structures formed in many binding processes.
RMRS claims that, by effectively binding the metals, the
Envirobond™ process reduces the waste stream's leachable
metal concentrations to less than regulated levels, and
thereby reduces the risks posed to human health and the
environment.
The Envirobond™ process can be deployed as an in situ or
ex situ treatment process. RMRS reports that the
Envirobond™ process is capable of achieving processing
rates of 20 to 40 tons per hour for ex situ treatment and can
be used with contaminated media containing as much as 10
percent debris.
Evaluation Activities
SITE Program personnel prepared the evaluation sites by
removing the sod, tilling the soil, and collecting samples of
untreated soil. Evaluation activities began on September 21,
1998. SITE Program personnel located several experimen-
tal units in the trailer park and at the inactive pottery factory.
The sod was removed from the experimental units, and the
units in the trailer park were tilled to a depth of 6 inches us-
ing a garden tiller. The units at the inactive pottery factory
were tilled using a backhoe to a depth of 6 inches. SITE Pro-
gram personnel screened the experimental units with a field
XRF analyzerfortotal lead concentrations.The screening re-
sults were used to select the units with high lead concentra-
tions. The Envirobond™ process was then applied to 10
experimental units in the trailer park and one experimental
unit at the inactive pottery factory. The experimental units at
the trailer park measured 5 feet wide by 5 feet long, and the
unit at the inactive pottery factory measured 3 feet wide by
6 feet long. Although RMRS injected the remediation fluid to
a depth of 2 feet, the depth evaluated during this evaluation
was limited to 6 inches.
Sampling of untreated soil in the trailer park consisted of
collecting composite soil samples from each experimental
unit. The composite soil samples were formed by collecting
approximately 1900 cubic centimeters of soil from five loca-
tions (each corner and the middle) of the experimental unit.
The soil was collected using a stainless steel spoon or trowel
and placed into a stainless steel bowl. The samples were
sieved through a brass, 0.375-inch sieve into a plastic, 5-
gallon bucket. All particles larger than 0.375 inch were re-
turned to the stainless steel bowl. The percentage of the
particles that did not pass through the sieve was estimated
and recorded in the logbook. The composite sample was
mixed in the bucket for 1 minute before the sample contain-
ers were filled.
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Sampling of untreated soil at the inactive pottery factory
consisted of collecting five grab samples from one experi-
mental unit. Approximately 1900 cubic centimeters of soil
was collected for each grab sample (one sample was col-
lected from each corner and from the middle) within the unit.
The soil was collected using a stainless steel spoon ortrowel
and placed into a stainless steel bowl. The soil sample was
sieved through a brass, 0.375-inch sieve into a plastic, 5-
gallon bucket. All particles larger than 0.375 inch were re-
turned to the stainless steel bowl. The percentage of the
particles that did not pass through the sieve was estimated
and recorded in the logbook. Each grab sample was mixed
in the bucket for 1 minute before the sample containers were
filled.The individual grab samples were not composited.
RMRS applied the Envirobond™ process afterthe sampling
of the untreated soil was completed at each experimental
unit. The Envirobond™ process powder was applied to the
surface of the experimental unit using a fertilizer drop
spreader.The Envirobond™ process liquid was applied over
the powder using a watering can.The Envirobond™ process
powder and liquid were mixed into the soil using a garden
tiller. Flyash was used to adjust the soil pH of each experi-
mental unit to approximately 7.0. A thin layer was distributed
over the surface of the experimental unit and tilled into the
experimental unit.
SITE Program personnel collected samples of treated soil
from the experimental units a minimum of 24 hours after
treatment with Envirobond™. Samples of treated soil were
collected from the trailer park using the same techniques as
the untreated soil samples; at the pottery factory, however,
four additional grab samples were collected from the mid-
points between the corners on each side.
Technology Applicability
RMRS claims that The Envirobond™ process can treat
heavy metals in soils, sludges, mine tailings and process
residues, and other solid waste. RMRS states the following
heavy metals can be stabilized with the Envirobond™ pro-
cess: arsenic, barium, cadmium, chromium, lead, mercury,
nickel, selenium, silver, and zinc (RMRS 1999). According
to RMRS, the Envirobond™ process can also stabilize
wastes contaminated with various radionuclides, including
thorium, uranium, radium, and cesium.
Technology Limitations
According to RMRS, metals such as aluminum, magnesium,
calcium, and manganese at concentrations greaterthan 30
percent by weight can reduce the bonding capability of the
Envirobond ™ process. RMRS reports that the Envirobond ™
process is not effective in treating soil with leachable lead
concentrations greaterthan 30 percent by weight.
Site Requirements
RMRS determines an appropriate site-specific concentration
of the Envirobond™ solution and powder through bench-
scale studies on soil samples.The site must be evaluated to
determine the contaminant concentration throughout the
site, and the concentration of other metals that may be
present at the site. The site conditions, such as soil type,
depth of contamination, and moisture content, must be evalu-
ated to determine the application procedure and equipment
requirements.
The technology may be applied with standard construction
and farming equipment. The site should be accessible to
wheeled or tracked vehicles and have sufficient storage
space forthe equipment. Potable water is required for apply-
ing the technology and for equipment and personnel decon-
tamination.
Process Residuals
Based on existing data, it appears that application of the
Envirobond™ process generates limited residual waste.The
chemicals in the Envirobond ™process bond with the lead to
form an insoluble metallic complex. However, personal pro-
tective equipment and decontamination fluids that contact
lead-contaminated soil may require management as poten-
tially hazardous waste.
Performance Data
Primary and secondary objectives were established for this
SITE evaluation to provide criteria for evaluating technology
performance. To achieve the evaluation objectives, SITE
Program personnel collected untreated and treated soil
samples from the experimental units.
Primary Objectives
Primary objective 1 (P1) was to evaluate whether
Envirobond ™ can treat soil contaminated with lead to meet
the Resource Conservation and Recovery Act (RCRA)/Haz-
ardous and Solid Waste Amendments (HSWA) alternative
universal treatment standards (UTS) for land disposal of soils
contaminated with lead.The alternative UTS forsoil contami-
nated with lead is determined from the results of the toxicity
characteristic leaching procedure (TCLP).The alternative
UTS is met if the concentration of lead in the TCLP extract
is no higherthan one of the following: (1) 7.5 milligrams per
liter (mg/L), or (2) 10 percent of the lead concentration in the
TCLP extract from the untreated soil. Contaminated soils with
TCLP lead concentrations below the alternative UTS meet
the RCRA land disposal restrictions (LDR), and thus are eli-
gible for disposal in a land-based RCRA hazardous waste
disposal unit. The alternative UTS is defined further under
Title 40 of the Code of Federal Regulations (CRF), Chapter
I, part 268.49 (40 CFR 268.49). To meet that objective, soil
samples were collected before and afterthe application of
Envirobond™.The untreated and treated soil samples were
analyzed forTCLP lead concentrations to evaluate whether
the technology met objective P1. Analysis of the data dem-
onstrated Envirobond™ reduced the mean TCLP lead con-
centration at the inactive pottery factory from 382 mg/L to 1.4
mg/L, a reduction of more than 99 percent. Therefore, the
treated soil meets the alternative UTS for soil.
Primary objective 2 (P2) was to evaluate whether
Envirobond™ could decrease the soil lead bioaccessibility
by 25 percent or more, as defined by the Solubility/
Bioaccessibility Research Consortium's (SBRC) Simplified
In-Vitro Method for Determining Soil Lead and Arsenic
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Bioaccessibility (simplified in vitro method [SIVM]). However,
EPA Lead Sites Workgroup (LSW) and Technical Review
Workgroup for lead (TRW) at this time, do not endorse an in-
vitro test for determining soil lead bioaccessibility (Interstate
Technology and Regulatory Cooperation [ITRC] 1997). To
meet objective P2, soil samples were collected before and
afterthe application of Envirobond™.The soil samples were
analyzed for soil lead bioaccessibility to evaluate whetherthe
technology met objective P2. Analysis of the data demon-
strates that Envirobond™ reduced the soil lead
bioaccessibility by approximately 12.1 percent, which is less
than the project goal of at least a 25 percent reduction in soil
lead bioaccessibility. However, it was recognized early on that
meeting this goal would be difficult because the SIVM test
procedure used in the demonstration involves a highly acidic
sample digestion process, which may be revised in the fu-
ture, because it may exceed the acid concentrations that
would be expected in a human stomach.
Secondary Objectives
The secondary objectives of the demonstration were:
S1 - Evaluate the long-term chemical stability of the treated
soil.
S2 - Demonstrate that the application of Envirobond™ did
not increase the public health risk of exposure to lead.
S3 - Document baseline geophysical and chemical condi-
tions in the soil before the application of Envirobond™.
S4 - Document the operating and design parameters of
Envirobond™.
S1 was evaluated primarily by analyzing soil samples using
the following analytical procedures: the multiple extraction
procedure (MEP), lead speciation using a scanning electron
microscope (SEM), lead speciation with a sequential extrac-
tion procedure, oxidation-reduction potential (Eh), pH, cat-
ion exchange capacity (CEC), acid neutralization capacity,
total lead (as determined by two methods), leachable lead
by the synthetic precipitation leaching procedure (SPLP),
total phosphates, and SPLP-leachable phosphates. The
evaluation was accomplished by comparing the results of the
analytical procedures on soil samples collected from both
sites before and after application of Envirobond™. Second-
ary objective S2 was evaluated by collecting air samples
during the sod removal, tilling, and soil sampling operations
and calculating exposure based on the total lead analysis of
the air sample filters. Air samples were collected during the
collection of untreated and treated soil samples. Secondary
objective S3 was evaluated by analyzing soil samples from
the experimental units at both demonstration sites for plas-
ticity, moisture content, predominant clay type of the soil, the
presence of volatile organic carbons (VOCs), semivolatile
organic compounds (SVOCs), oil and grease content, and
humic and fulvic acid concentrations. Secondary objective
S4 was established to provide data for estimating costs as-
sociated with use of the Envirobond™, and was based on
observations during the evaluation, and data to be provided
by RMRS.
Site Evaluation Results
This section summarizes the results of the SITE evaluation
and includes an evaluation of the primary and secondary
objectives.
Evaluation of Objective P1
The TCLP lead concentrations from the inactive pottery fac-
tory were used to evaluate objective P1 .The TCLP extrac-
tion was performed according to SW846 Method 1311 .The
extracts were digested by SW846 Method 301OA, and the
lead concentration was determined using ICP-AES accord-
ing to SW-846 Method 601 OB. Soil samples from the inac-
tive pottery factory were collected before and after
application of the technology. The results from analyses of
the treated soil were evaluated to determine if the lead in the
soil was leaching at levels above the alternative UTS of 7.5
mg/LTCLP lead.
The data analysis shows that the Envirobond™ process re-
duced the TCLP lead concentration to below the alternative
UTS of 7.5 mg/L at the inactive pottery factory site.The tech-
nology reduced the mean TCLP lead concentration from 382
mg/L to 1.4 mg/L. Therefore, the TCLP lead concentrations
were reduced by at least 90 percent.Table 2 summarizes the
TCLP lead data from five sampling locations within the ex-
perimental unit at the inactive pottery factory site.
Evaluation of Objective P2
Objective P2 requires using an in-vitro test to evaluate the
relative percentages of bioavailable lead in untreated and
treated soils from the trailer park site. For this demonstration,
the simplified in vitro method (SIVM) developed by the Solu-
bility/Bioavailability Research Consortium (SBRC) was se-
lected to evaluate the relative percent bioavailability of lead
in soil. The SBRC consists of representatives from the fed-
eral and state regulatory agencies, academia and other re-
search organizations, and the regulated community. The
SIVM determines the relative percent of bioavailability of lead
in soil by calculating the ratio of the lead in the sample be-
fore extraction to the amount of lead that leached using an
extraction solution that simulates gastric fluid. However, the
EPA Lead Sites Workgroup (LSW) and the EPA Technical
Review Workgroup (TRW) for lead, at this time, do not en-
dorse an in-vitro test for determining lead bioavailability.
The relative percent bioavailable data is used to determine
if the technology would reduce the risk of exposure to the
bioavailable lead in the soil. The risk of exposure is deter-
mined by calculating the percent reduction in the relative
percent bioavailable lead, which is calculated by dividing the
relative percent bioavailable lead afterthe application of the
technology to the relative percent bioavailable lead before the
application of the technology and multiplying by 100.
The data are not intended to be used to support a risk-based
cleanup level for the soil, such as a level that is determined
using EPA's Integrated Exposure Uptake Biokinetic model
(IEUBK). IEUBK is used to determine if the lead exposure
(from various sources) on a residential property has no more
than a 5 percent probability that a child's blood lead level will
exceed 10 micrograms per deciliter.
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Table 2. TCLP Lead Results from the Envirobond™ Process Evaluation
Experimental Unit
U
U
U
U
U
U
U
U
U
Sampling Location
1
2
3
4
5
6
7
8
9
Untreated Soil TCLP Lead
Concentration (mg/L)
421
563
320
247
358
n/s
n/s
n/s
n/s
Treated Soil TCLP Lead Concentration
(mg/L)
2.0
1.5
1.4
O.50
1.5
2.1
0.94
1.7
1.5
Note: n/s = Statistical experimental design only required five pretreatment samples for TCLP analysis. Nine grab post-treatment
samples were collected instead of five to obtain a more precise estimate of the post-treatment mean.
The technology decreased the relative percent bioavailable
lead by approximately 12.1 percent. Although the technology
did not achieve the goal of objective P2, which is reducing
the relative percent bioavailable lead by 25 percent, it was
recognized early on that meeting this goal would be difficult
because the SIVM test procedure used in the demonstration
involves a highly acidic sample digestion process. The SIVM
may be revised in the future, because it may be exceeding
the acid concentrations that would be expected in a human
stomach.Table 3 summarizes the bioavailable lead data.
Evaluation of Objective S1
Objective S2 was evaluated using the results of 11 analyti-
cal procedures that were conducted to predict the long-term
chemical stability of the treated soil. Soil treated with
Envirobond™ appears to exhibit overall long-term chemical
stability. However, the results of some of the analytical pro-
cedures suggest that Envirobond™ does not appearto ex-
hibit long-term chemical stability. In summary:
— Long-term soil chemical stability was indicated for soils
treated by Envirobond™ at both test locations, as indicated
by the analytical results of the multiple extraction procedure
(MEP), the procedure for lead speciation by sequential ex-
traction, the test for cation exchange capacity (CEC), and
leachable lead by the simulated precipitation leaching pro-
cedure (SPLP).The CEC results are considered to be quali-
tative, because this test was conducted on only a single
sample from each location.
— Long-term chemical stability was indicated at one site, but
not at the other, by the analytical results of procedures for
evaluating acid neutralization capacity. The results of tests
on acid neutralization capacity are considered to be quali-
tative, because this test was conducted on only a single
sample from each location.
— The analytical results from the lead speciation test by
scanning electron microscopy (conducted only on soils from
the trailer park) were mixed, in that the silica phosphate
phase (low solubility) of lead was increased and some
soluble phases of lead were reduced, while other low-solu-
bility phases of lead were also reduced.
— At both locations, long-term chemical stability was not
indicated for soils treated by Envirobond™by the results of
the pH analyses, Eh analyses, separate analyses for total
lead by nitric and hydrofluoric acids; total phosphates; and
SPLP phosphates (The tests involving two types of total lead
analysis were extremely aggressive tests; thus, meeting the
acceptance criteria established forthese tests was not as im-
portant as meeting the acceptance criteria of other tests in-
volving long-term chemical stability).
Evaluation of Objective S2
SITE Program personnel collected air samples during the
sod removal, tilling and soil sampling operations and calcu-
lated exposure based on the total lead analysis of the air
sampling filters. Ten out of 11 samples did not indicate the
presence of lead above the detection limit of 0.004 mg/m3.
The result above the detection limit, 0.024 mg/m3, was found
to be within applicable exposure guidelines, which include
the Occupational Health and Safety Administration Permis-
sible Exposure Limits (OSHA PELs), the American Confer-
ence of Governmental Industrial Hygiene Threshold Limit
Values (ACGIHTLVs), the National Institute for Occupational
Safety and Health Recommended Exposure Limits (NIOSH
RELs), and the National Ambient Air Quality Standards Pro-
gram (NAAQS) limits. Based on these results, the risk to
public health and worker exposure was not increased due to
the demonstration activities.
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Table 3. Relative Percent Bioavailable Lead Results from the Envirobond™ Process Evaluation
Experimental Unit
A
B
D
E
F
H
1
J
P
S
Untreated Soil Percent
Bioavailable Lead
51.2
50.4
63.3
62.4
58.8
45.0
41.5
47.4
48.7
37.5
Treated Soil Percent
Bioavailable Lead
37.6
33.7
48.1
46.8
45.6
41.6
55.6
45.8
41.0
38.6
Note: Negative values equal an increase in the soil lead bioaccessibility.
Evaluation of Objective S3
Soil samples from the experimental units at both demonstra-
tion sites were analyzed for plasticity, moisture content, pre-
dominant clay type of the soil, the presence of volatile organic
carbons (VOCs), semivolatile organic compounds (SVOCs),
oil and grease content, and humic and fulvic acid concen-
trations.
Table 4 lists the plastic index, liquid limit, and soil type from
the analyses of the soil samples from both sites using the
American Society forTesting and Materials (ASTM) Method
D 2487-93, Standard Classification of Soils for Engineering
Purposes.
The VOC analytical results did not indicate the presence of
any volatile organics in the soils at either site. The SVOC
analysis indicated the presence of the following SVOCS in
the soils at the inactive pottery factory site:
benz(a)anthacene (0.82 mg/kg), benzo(b)fluoranthene (0.91
mg/kg), benzo(k)fluoranthene (0.77 mg/kg), benzo(a)pyrene
(0.69 mg/kg), chrysene (1.0 mg/kg) fluoranthene (1.9 mg/
kg), and pyrene (1.9 mg/kg). These SVOCs are typically
found in crude oil, gasoline, or used motor oil.
The soil in this area did show signs of staining that may be
the result the disposal of a small quantity of waste oil. Based
on these concentrations and the current state regulations for
petroleum releases, it does not appear that the SVOCs
present at the site require remediation. Also, the technology
developer indicated that these SVOCs will not interfere with
the Envirobond™ process.The analytical results forthe in-
active pottery factory indicate the presence of oil and grease
at a concentration of 3,680 mg/kg.The analytical results for
the trailer park site did not indicate the presence of oil and
grease.
The concentration of humic acid at the trailer park site was
2,400 mg/L, and the mean concentration of humic acid at the
inactive pottery factory site is 1,400 mg/L. The concentra-
tion of fulvic acid at the trailer park site was 600 mg/L, and
the mean concentration of fulvic acid at the inactive pot-
tery factory site was less than 500 mg/L.
Evaluation of Objective S4
Using information obtained from the SITE evaluation, RMRS,
and other sources, an economic analysis examined 12 cost
categories for a scenario in which the Envirobond™ process
Table 4. Soil Classification information
Site
Trailer Park
Inactive Pottery Factory
Plastic Index
8
11
Liquid Limit
42
46
Soil Type
Sandy Silt
Sandy Silt
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was applied at full scale to treat lead-contaminated soil at a
Superfund site. The cost estimate assumed the site was 1
acre in size, and the treatment was applied to a depth of 6
inches, which is approximately 807 cubic yards (yd3). The
estimate assumes the site's soil characteristics and lead con-
centrations were the same as those encountered during the
CRPAC evaluation. Based on these assumptions, the total
costs were estimated to be $33,220 per acre or $41.16 per
yd3. Costs for application of the Envirobond™ process may
vary significantly from this estimate, depending on site-spe-
cific factors.
Technology Status
RMRS has completed several bench-scale studies and pi-
lot-scale tests on soil and debris contaminated with heavy
metals and radionuclides. The Envirobond™ process has
been used on several full-scale commercial sites contami-
nated with metals, and is currently being used to stabilize
waste and debris contaminated with radionuclides at two
government facilities.
References
Canadian Society of Soil Science. 1993. "Soil Sampling and
Methods of Analysis." Chapters 19 and 38. Lewis Publish-
ers. 1993.
Evans, G. 1990. "Estimating Innovative Treatment Technol-
ogy Costs for the SITE Program." Journal of Air and Waste
Management Association. Volume 40, Number?. July.
Environment Canada Method Number 7.
Interstate Technology and Regulatory Cooperation (ITRC)
Work Group. 1997. "Emerging Technologies for the
Remediation of Metals in Soils: In situ Stabilization/lnplace
Inactivation." December.
R.S. Means, Company, Inc. 1998. Environmental Restoration
Assemblies Cost Book. R.S. Means Company, Inc., Kingston,
Massachusetts.
Northern Kentucky University (NKU). 1999. Letter Regard-
ing Technical Review of Soil Amendment Technologies, Cat-
ion Exchange Capacity Assessment. From Lee Otte, Senior
Consultant.To David Gilligan, Project Manger, Tetra Tech EM
Inc. (Tetra Tech) October 7.
Ohio Environmental Protection Agency. 1998. "Interim Re-
port and Proposal for Additional Work, Crooksville/Roseville
Pottery Area of Concern Geographic Initiative." March. Pre-
pared for Environmental Protection Agency.
Rocky Mountain Remediation Services, L.L.C. (RMRS)
1999. Facsimile Regarding Costs Associated with the
Envirobond™ Process. From Mike Harper, RMRS, To David
Remley, Tetra Tech. July.
Solubility/Bioavailability Research Consortium (SBRC).
1998. "Simplified In Vitro Method for Determination of Lead
and Arsenic Bioaccessibility" Unpublished.
Tessier, A. 1979. "Sequential Extraction Procedure for the
Speciation of Particulate Trace Metals." Analytical Chemis-
try. Volume 51, Number7. Pages 844-850.
Tetra Tech EM Inc. (Tetra Tech) 1998. "Evaluation of Soil
Amendment Technologies at the Crooksville/Roseville Pot-
tery Area of Concern: SITE Program Final Quality Assurance
Project Plan." Prepared for EPA under Contract No. 68-35-
0037. November.
Tetra Tech 1999a. "Technology Capsule for Rocky Mountain
Remediation Services Envirobond™ Process." July.
Tetra Tech 1999b. Rocky Mountain Remediation Services,
L.L.C. "Evaluation of Soil Amendment Technologies at the
Crooksville/Roseville Pottery Area of Concern: SITE Pro-
gram Demonstration Technology Evaluation Report." Pre-
pared for EPA under Contract No. 68-35-0037. December.
Tetra Tech 1999c. "Evaluation Bulletin for Rocky Mountain
Remediation Services Envirobond™ Process." June.
Tetra Tech 1999d.Telephone communication between Chris
Preston, Tetra Tech, and Rich Jensen, RMRS. August 6.
U.S. Environmental Protection Agency (EPA). 2000. EPA
Region 9 Preliminary Remediation Goals (PRG 2000) No-
vember http://www.epa.gov/region09/waste/sfund/prg/
index.htm
EPA. 1988. Protocol for a Chemical Treatment Demonstra-
tion Plan. Hazardous Waste Engineering Research Labora-
tory. Cincinnati, Ohio. April.
EPA. 1996.Test Methods for Evaluating Solid Waste, Volumes
IA-IC: Laboratory Manual, Physical/Chemical Methods; and
Volume II: Field Manual, Physical/Chemical Methods, SW-
846, Third Edition, Update III, Office of Solid Waste and
Emergency Response, Washington D.C. December.
EPA. 1983. Methods for Chemical Analysis of Water and
Wastes EPA-600/4-79-020, Environmental Monitoring and
Support Laboratory, Cincinnati, Ohio, and subsequent EPA-
600/4 technical additions.
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Sources of Further Information
EPA SITE Program
Edwin Earth, EPA Project Manager
U.S. Environmental Protection Agency
Office of Research and Development
26 W. Martin Luther King Drive
Cincinnati, Ohio 45268
(513)569-7669
(513)569-7571 (fax)
E-mail: barth.ed@epamail.epa.gov
Technology Developer
AliSogue
Rocky Mountain Remediation Services
1819 Denver West Drive
Building 26, Suite 200
Golden, Colorado 80401
(303)215-6686
(303) 215-6786 (fax)
E-mail: asogue@rmrshq.com
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?/EPA
United States
Environmental Protection
Aflencv
National Risk Management
Research Laboratory
Cincinnati, OH 45268
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