United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R07-89/031
September 1989
Superfund
Record of Decision
Kem-Pest Laboratories, MO
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R07-89/031
3. Recipients Accession No.
4. Tito and Subtitle
SUPERFUND RECORD OF DECISION
Kern-Pest Laboratories, MO
First Remedial Action
S. Report Date
09/29/89
7. Author(»)
8. Performing Organization Rept No.
9. Performing Organization Name and Address
10. Project/Taak/Work Unit No.
11. Contnct(C) or Grant(G) No.
(C)
(G)
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/000
14.
IS. Supplementary Notes
16. Abstract (Limit: 200 words)
The Kern-Pest Laboratories site is a former pesticide manufacturing facility
approximately 3-miles northeast of Cape Girardeau, Cape Girardeau County, Missouri. This
6-acre site is in a rural area devoted primarily to agricultural activities.
I Contamination at the site resulted from the manufacturing of pesticide products from 1965
luntil 1977. Production activities took place in an onsite concrete block formulation
Building. Sewage and plant wastes were disposed of in an onsite lagoon which was
Backfilled with clay in 1981. EPA investigations beginning in 1981 have identified
pesticide and volatile and semi-volatile organic contamination in soil, sediment in
drainage channels, and in ground water. This operable unit addresses contaminated soil
and sediment. Future operable units will address ground water and the formulation
building. The primary contaminants -of concern affecting the soil and sediment are VOCs
including xylenes, other organics including organochlorine and pesticides, and metals
including arsenic.
The selected remedial action for this site includes excavating approximately 4,050 cubic
yards of contaminated soil and sediment with offsite disposal in a RCRA-approved
commercial hazardous waste landfill; sampling to verify that the extent of excavation is
(See Attached Sheet)
MO
17. Document Analysis a. Descriptors
Record of Decision - Kem-Pest Laboratories,
First Remedial Action
Contaminated Media: soil, sediment
Key Contaminants: VOCs (xylene), other organics (pesticides), metals (arsenic)
b. Identfflers/Open-Ended Terms
c. COSATI Reid/Group
B8. Availability Statement
19. Security aasa (This Report)
None
20. Security Class (This Page)
None
21. No. of Pages
76
22. Price
(See ANSI-Z39.18)
See Instructions on Reverse
OPTIONAL rORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R07-89/031
Kern-Pest Laboratories, MO
First Remedial Action
6. Abstract (Continued)
sufficient to meet health based cleanup goals; and backfilling the excavated area with
clean soil and revegetating. .•The estimated present worth cost for this remedial action
is $2,600,000 with no O&M required.
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RECORD OF DECISION
SOIL AND SEDIMENT OPERABLE UNIT
KEM-PEST LABORATORIES SITE -
CAPE GIRARDEAU COUNTY, MISSOURI
Prepared by:
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION VII
m
KANSAS CITY, KANSAS
SEPTEMBER 1989
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RECORD OF DECISION DECLARATION
SOIL AND SEDIMENT OPERABLE UNIT
JAME AND LOCATION
Kern-Pest Laboratories Site
Cape Girardeau County, Missouri
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action
for soil and sediment at the Kern-Pest Laboratories site in Cape
Girardeau County, Missouri, chosen in accordance with the
Comprehensive Environmental Response, Compensation and Liability
Act (CERCLA), as amended by the Superfund Amendments and
Reauthorization Act (SARA) and, to the extent practicable, the
National Contingency Plan. This decision is based on the
administrative record file for this site.
The State of Missouri concurs on the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response action
selected in this Record of Decision, may present a current or
potential threat to public health, welfare, or the environment.
DESCRIPTION OF THE REMEDY
Remedial action will be implemented through a series of
operable units. This operable unit is the first of three that
are planned for the site. The first operable unit will address
contaminated soil and sediment. The future operable units will
address ground water and the formulation building.
The major components of the selected remedy include:
Excavation of approximately 4050 cubic yards of
contaminated soil and sediment; and
- Disposal at an offsite land disposal facility in
compliance with the requirements of Subtitle C of
the Resource Conservation and Recovery Act (RCRA)
and other applicable laws or regulations.
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DECLARATION
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that
are legally applicable or relevant and appropriate to the
remedial action, and is cost-effective. This remedy utilizes
permanent solutions and alternative treatment technologies to the
maximum extent practicable for this site. However, because
treatment of the principal threats of the site was not found to
be practicable, this remedy does not include treatment as a
principal element. Treatment of soils at the concentrations
detected at this site would result in long-term effectiveness
similar to that afforded by containment at a RCRA-approved
hazardous waste landfill but at a cost significantly higher than
containment. Because the selected remedy will not result in
hazardous substances remaining onsite above health-based levels,
the five-year review will not apply to this action.
ris Kay, Regional Administrator
/
Date
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RECORD OF DECISION
SOIL AND SEDIMENT OPERABLE UNIT
DECISION SUMMARY DOCUMENT
KEM-PEST LABORATORIES SITE
CAPE GIRARDEAU COUNTY, MISSOURI
Prepared by:
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION VII
KANSAS CITY, KANSAS
»
SEPTEMBER 1989
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TABLE OF CONTENTS
1.0 INTRODUCTION
2.0 SITE LOCATION AND DESCRIPTION
3.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
4.0 COMMUNITY PARTICIPATION ACTIVITIES
5.0 SCOPE AND ROLE OF OPERABLE UNIT
6.0 SUMMARY OF SITE CHARACTERISTICS
6.1 NATURE AND EXTENT OF CONTAMINATION
6.2 CONTAMINANT FATE AND TRANSPORT
7.0 SUMMARY OF SITE RISKS
7.1 METHODOLOGY
7.2 RISK ASSESSMENT RESULTS
8.0 DESCRIPTION OF ALTERNATIVES
8.1 NO ACTION
8.2 EXCAVATION AND ONSITE INCINERATION
8.3 EXCAVATION AND OFFSITE INCINERATION
8.4 EXCAVATION AND ONSITE LANDFILL
8.5 EXCAVATION AND OFFSITE LANDFILL
8.6 EXCAVATION AND CAPPING
9.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
9.1 OVERALL PROTECTION OF HUMAN HEALTH AND ENVIRONMENT
9.2 COMPLIANCE WITH ARARS
9.3 LONG-TERM EFFECTIVENESS AND PERMANENCE
9.4 REDUCTION OF TOXICITY, MOBILITY, OR VOLUME
9.5 SHORT-TERM EFFECTIVENESS
9.6 IMPLEMENTABILITY
9.7 COST
9.8 STATE ACCEPTANCE
9.9 COMMUNITY ACCEPTANCE
10.0 SELECTED REMEDY
10.1 DESCRIPTION
10.2 REMEDIATION GOALS
11.0 STATUTORY DETERMINATIONS
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TABLE OF CONTENTS
(CONTINUED)
ATTACHMENT A
TABLE A-l SUMMARY OF CHEMICALS DETECTED IN SUBSURFACE SOIL
TABLE A-2 SUMMARY OF CHEMICALS DETECTED IN SURFACE SOIL -
COMPOSITE SAMPLES
TABLE A-3 SUMMARY OF CHEMICALS DETECTED IN SURFACE SOIL -
DISCRETE SAMPLES
TABLE A-4 SUMMARY.OF CHEMICALS DETECTED IN DRAINAGE CHANNELS
FIGURES A-l LOCATION OF SUBSURFACE SOIL SAMPLES
& A-2
FIGURE A-3 LOCATION OF SURFACE SOIL SAMPLES
FIGURE A-4 LOCATION OF SEDIMENT SAMPLES
ATTACHMENT B
TABLE B-l CHEMICALS OF CONCERN SUMMARY TABLE
TABLE B-2 SUMMARY OF POTENTIAL RISKS
ATTACHMENT C
FIGURE C-l EXCAVATION AREAS
ATTACHMENT D
TABLE D-l SUMMARY OF COST ESTIMATES
»
TABLE D-2 REMEDIATION GOALS FOR SURFACE SOIL
TABLE D-3 REMEDIATION GOALS FOR SUBSURFACE SOIL
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1.0 INTRODUCTION
The Kern-Pest Laboratories site is located in Cape Girardeau
County, Missouri. From 1965 to 1977, the company formulated
pesticide products at the site. Sewage and plant wastes were
disposed of in an onsite lagoon. Remedial investigation
activities conducted in December 1988 and February and March of
1989 identified pesticide, volatile organic and semivolatile
organic contaminants in soil, sediment and ground-water and
pesticide contamination in the formulation building.
Remedial action will be implemented through a series of
operable units, or discrete response actions. The first operable
unit addresses contaminated soil and sediment. Future operable
units will address ground water and the formulation building.
Remedial alternatives for contaminated soil and sediment
were developed in the Operable Unit Feasibility Study (OUFS). In
the Proposed Plan, excavation of contaminated soil and sediment
and disposal at an offsite hazardous waste landfill was
identified as the preferred alternative.
The Record of Decision (ROD) for the Kern-Pest site presents
the final remedy selected for the contaminated soil and sediment
operable unit, chosen in accordance with the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980
(CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA) and, to the extent
practicable, the National Contingency Plan (NCP).
The purpose of this Decision Summary, a major component of
the ROD, is to provide an overview of site characteristics, the
alternatives evaluated and the rationale for the final remedy
selection.
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2.0 SITE LOCATION AND DESCRIPTION
BACKGROUND
The Kern-Pest Laboratories site is located in Cape Girardeau
County, Missouri, approximately three miles northeast of the City
of Cape Girardeau. The site occupies approximately six acres of
land. A map of the vicinity and site location is presented on
Figure 1.
\
The surrounding area is predominantly rural. Currently
three residences are located within 1,000 feet of the site to the
west and southwest; ten additional residences lie within a 1,000-
foot radius to the north, northwest and northeast. Adjacent to
the site on the south is the St. Louis-San Francisco railroad
tracks. The Mississippi River is about 1,000 feet further south.
An industrial storage tank facility and agricultural fields are
located between the river and railway. Fields are also northeast
of the site.
Information from the U.S. Department of the Interior, Fish
and Wildlife Service, and the Missouri Department of Conservation
indicated there are no sensitive environments within a one-mile
radius of the site. Sensitive environments would include
wetlands, critical habitats of endangered species, and national
wildlife refuges.
A 40 by 100 foot concrete block building is located on the
site which housed the Kern-Pest pesticide formulation operation.
Six storage tanks used for the storage of solvents and oil are
north of the formulation building. A two-celled lagoon used for
the disposal of sewage and plant waste is located approximately
40 feet southwest of the building. A scrap pile of miscellaneous
debris lies to the northeast of the building. A site map is
presented on Figure 2.
SITE GEOLOGY AND HYDROGEOLOGY
The site is loca-ted on portions of an alluvial terrace and
upland on the west bank of an encroaching meander of the
Mississippi River. Borings made during site investigations
encountered unconsolidated alluvial deposits consisting of silty
clay with localized sand lenses overlying colluvial deposits
consisting of gravelly sand with some clay. The silts and clays
range in depth from 42 to 55 feet from the ground surface. The
thickness of the colluvium is unknown but greater than 15 feet.
Ground water monitoring wells were installed to monitor
ground water within both the alluvial and colluvial deposits.
Based on data obtained during the remedial investigation (RI),
ground water flow is generally to the south-southeast in the
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silty clay and to the south in the gravelly sand. The RI data
also indicates there is one unconfined aquifer system present
within the alluvial and colluvial deposits at the site.
TOPOGRAPHY
The topography of the area is characterized by rolling
landscape to the west and relatively flat terrain between the
site and the Mississippi River. The site is located outside, but
immediately adjacent to, the 500-year flood plain.
Runoff from the site, particularly the lagoon area, flows
southeast to a drainage channel along the railroad track. This
drainage channel flows southwest to a culvert which runs under
the tracks. From the culvert, water flow reaches the river about
900 feet away.
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-7v.ai^ch.pfl^:5>^ ';#*.
^-^.^..^:^^\:^ ^-sT :.'-:
KEM-PEST
LABORATORIES
HflMDCi; U • (COLO«ICIMO !•»«.
FIGURE 1
SITE VICINITY MAP
LABOHAIORIES
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PROPERTY BOUNDARY
300 FT
so'
APPROXIMATE
SITE BOUNDARY
TO MISSISSIPPI RIVER fc) 900 FT)
Sf I GUIS CORPS OF ENGINEERS FOR
USEPA fNVI80HMEN1AL MONItOHINO
STSIEMS LAeOHATORl, LAS VCGAS. NV.
JUNE 6, I9U8
FIGURE 2
SITE MAP
KEU-PEST LABORATORIES
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3.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
The Kern-Pest plant was constructed in 1964. From 1965 to
1977, the company formulated various pesticide products including
liquid pesticides, granular insecticide, granular herbicide, and
pesticide dust. The plant generated wastes from the formulation
of pesticides containing the following: aldrin, dieldrin, 2,4-
dichlorophenoxyacetic acid (2,4-D), endrin, heptachlor, methyl
parathion and thiuram.
The plant wastes were disposed of in the onsite lagoon. The
lagoon was backfilled with clay by the property owner in 1981.
There have been no production, treatment or disposal activities
at the site since 1977. The building has been used for storage
of equipment and materials.
The U.S. Environmental Protection Agency (EPA) conducted a
preliminary assessment of the facility in September 1981.
Erosion of the lagoon cover and chemical odors were noted. In
March 1983, soil samples were obtained from the lagoon area and
ground water samples were collected from the plant production
well and two private wells in the area. Pesticide contamination
was detected in the soil samples; no contamination was identified
in these wells.
In April 1984, EPA installed five monitoring wells onsite
and collected ground water, soil and sediment samples.
Pesticides, volatile and semivolatile organics were detected in
soil, sediment and ground water onsite. The Kern-Pest site was
proposed for the National Priorities List (NPL) in January 1987.
Pursuant to an Administrative Order on Consent entered into
in November 1988, the potentially responsible parties (PRPs)
conducted sampling of soils from the lagoon and the formulation
building in December 1988.
In February and March 1989, EPA conducted the RI field
activities which included collection of soil and sediment
samples, installation, of six downgradient monitoring wells, and
collection of ground water samples from onsite and offsite
monitoring wells and two private wells in the immediate area.
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4.0 COMMUNITY PARTICIPATION ACTIVITIES
Prior to the initiation of the RI, a community relations
plan was developed based on interviews conducted by the community
relations staff with residents and local officials. The plan
documented the issues of concern to the community and outlined
future community relations activities.
At the start of RI field activities, the EPA remedial
project manager met with the Cape Girardeau County Commission and
other local county and city officials to discuss the field work.
The project manager also conducted informal interviews at nearby
residences to inform them of site activities and to answer
questions. Fact sheets about the project were mailed to
residents, local officials and the media. During field work,
nearby residents and local officials were provided updated
information on activities.
In August 1989, the RI and OUFS reports and Proposed Plan
were made available to the public in the administrative record
located at the Cape Girardeau Public Library and at EPA Region
VII offices in Kansas City. A public notice was issued
announcing the availability of documents, the start of the public
comment period and the date of the public meeting. The public
notice was published in the Southeast Missourian on August 18,
1989, and in the Cape Girardeau News Guardian on August 23, 1989.
Fact sheets were also mailed to residents, local officials
and the media announcing the availability of documents, the
public comment period and the public meeting.
The public comment period was held from August 18, 1989,
through September 18, 1989. A public meeting was held in Cape
Girardeau on September 5, 1989. At the meeting, representatives
from EPA, the Agency for Toxic Substances and Disease Registry
(ATSDR) and the Missouri Department of Natural Resources (MDNR)
provided information on the site and discussed the remedial
alternatives under consideration. During an extension of the
comment period, the EPA community relations staff conducted
interviews with concerned citizens.
A response to comments received during the public comment
period is provided in the Responsiveness Summary, which is a part
of this Record of Decision.
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5.0 SCOPE AND ROLE OF OPERABLE UNIT
Remedial action at the Kern-Pest site will be implemented
through a series of operable units, or discrete actions. The
phasing of cleanup actions will provide the opportunity to
achieve significant risk reduction more quickly than addressing
the entire site at one time. This first operable unit addresses
contaminated soil and sediment. Future operable units will
address ground water and the formulation building.
This first operable unit addresses contaminated subsurface
soil in the lagoon, surface soil in the lagoon area and near the
formulation building, and sediment in drainage channels on and
off the site. These areas pose the principal threat to human
health and the environment due to the potential for dermal
contact, ingestion and inhalation.
The objectives of this first operable unit are to remove or
reduce to a protective level the risks posed by dermal contact,
ingestion or inhalation of contaminated soil and sediment, to
eliminate or reduce the potential for offsite transport of
contaminated material, and to remediate contaminated soil and
sediment in a manner which will not adversely affect future
remedial actions, if required.
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6.0 SUMMARY OF SITE CHARACTERISTICS
The EPA conducted RI field work in February and March 1989
to determine the nature and extent of contamination and the need
for remedial action. The PRPs also conducted sampling in
December 1988. This section summarizes information obtained by
these activities; soil sample locations and results are provided
in Attachment A.
6.1 NATURE AND EXTENT OF CONTAMINATION
SUBSURFACE SOIL
Ten borings were drilled in the area of the lagoon, ranging
from 3 to 14 feet in depth. A total of 28 subsurface soil
samples were submitted for analysis.
Based on the boring data, pesticide concentrations generally
decreased with depth below the base of the lagoon (5-6 feet below
the surface). Contamination was greatest in the 6-9 foot level.
Pesticides identified most often and at highest concentrations
included gamma-chlordane (74,500 micrograms per kilogram
(ug/kg)), heptachlor (45,700 ug/kg), and endrin (14,000 ug/kg).
Volatile organics identified frequently and at the highest
concentrations included xylenes (28,000 ug/kg), ethylbenzene
(5000 ug/kg), and 1,2-dichloroethane (700 ug/kg). Concentrations
generally increased with depth below the lagoon, with maximum
levels below the ground water table. Semivolatiles detected
included pentachlorophenol (19,000 ug/kg) and 2,4-dichlorophenol
(8600 ug/kg); semivolatiles generally decreased with depth. The
only metal of concern to health detected above regional maximum
background levels was arsenic at 160 milligrams (mg)/kg.
SURFACE SOIL
To better characterize the entire site, 26 composite samples
were collected from two grid systems and analyzed for pesticides.
One grid consisted of 50 by 50 foot squares in the area of the
lagoon and formulation building with samples obtained from 0-6
and 6-12 inches. The second grid consisted of 100 by 100 foot
squares over areas which may have been affected by site
operations; samples were obtained from the 0-6 inch depth.
For the 0-6 inch depth interval, pesticide contamination was
greatest in grids adjacent to the building. Pesticides detected
most often and at the highest concentrations included heptachlor
(76,000 ug/kg), dieldrin (58,000 ug/kg) and gamma-chlordane
(39,000 ug/kg). For the 6-12 inch interval, contamination was
also greatest in grids near the building; heptachlor (94,000
ug/kg), gamma-chlordane (80,000 ug/kg) and endrin (26,000 ug/kg).
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Discrete surface soil samples from 0-6 inches were obtained
from several site locations including southeast of the lagoon,
the storage tank area and scrape pile area. Analyses included
volatiles, semivolatiles, pesticides, total metals and cyanide.
Heptachlor at 32,000 ug/kg and gamma-chlordane at 21,000
ug/kg were detected in soil southeast of the lagoon. Relatively
low pesticide concentrations were found at the other locations.
Volatiles and semivolatiles were not detected at significant
levels. Arsenic (170 mg/kg) and lead (110 mg/kg) were detected
at one location, exceeding site background and regional maximum
concentrations.
SEDIMENT
Composite sediment samples at depths of 0-6 and 6-12 inches
were collected by EPA in drainage channels on the Kern-Pest
property and in the offsite drainage channel immediately
southeast of the property (parallel to the railroad tracks) to
assess the extent of contaminant migration. The composite
sediment samples were analyzed for pesticides.
Pesticide concentrations above background were detected in
all but one sample. Significant concentrations were detected in
drainage channels from the south corner of the building and from
the southeast corner of the lagoon.
The highest concentrations for the 0-6 inch interval were
detected in the offsite channel which runs parallel to the
tracks. The channel segment located southeast of the building
had the highest concentrations (20,000 ug/kg heptachlor, 58,000
ug/kg aldrin, 34,000 ug/kg dieldrin and 26,000 ug/kg gamma-
chlordane) . Concentrations in this channel generally decreased
with distance downgradient (to the southwest).
Significant contamination was detected in 6-12 inch samples
from the same drainage channels identified above. The highest
concentrations were also in the offsite channel, with levels
again generally decreasing to the southwest.
6.2 CONTAMINANT FATE'AND TRANSPORT
Based on the results of the site investigations, sources of
contamination are the waste disposal lagoon and areas where
hazardous substances may have spilled or leaked which include the
formulation building, storage tanks, loading areas and piping to
the lagoon. The lagoon and soil south, southeast and southwest
of the building appear to be the most significantly contaminated.
The potential routes of migration include infiltration and
direct migration through surface and subsurface soil, ground
water transport, erosion and surface runoff, and air transport.
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The subsurface conditions at the site indicate that sorption
will retard the migration of contaminants due to the organic
content and low hydraulic conductivity of the alluvial material.
Residual contamination by the more strongly adsorbed compounds
may remain for decades in the alluvial material. Subsurface
contamination in the lagoon area remains a source that could
continue to release contaminants to ground water through
infiltration and leaching mechanisms.
The organochlorine pesticides are very insoluble in water
and are readily adsorbed to soil particles. These pesticides are
very immobile and are extremely persistent. Biodegradation does
not occur significantly in the field. Volatile organics are
generally water soluble and less readily adsorbed to the soil and
are more mobile in ground water systems than pesticides. The
solubility and adsorptive tendencies of semivolatile compounds
fall between those of the pesticides and the volatiles.
Surface runoff may transport contaminants either in solution
or adsorbed to eroded soil particles. The potential mechanisms
for air transport of contaminants are volatilization arid fugitive
emissions of particulates on which contaminants are adsorbed.
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7.0. SUMMARY OF SITE RISKS
To evaluate the potential impacts to human health in the
absence of remedial action, a risk assessment was conducted as
part of the RI. Both current and future land use scenarios were
evaluated. This section summarizes the Agency's findings
concerning risks from exposure to .contaminated soils and sediment
at the site. The complete risk assessment is contained in Volume
II of the RI report.
METHODOLOGY
A total of 39 chemicals detected in the soil and sediment
were identified as chemicals of concern. A summary table of the
chemicals of concern is provided in Attachment B.
Exposure pathways by which humans could be exposed to
chemicals of concern were identified based on reasonable
assumptions regarding current and future uses of the site. For
current land-use conditions, direct contact with surface soils
and sediments by children trespassing onto the site was
evaluated.
With respect to future land uses, both residential and
industrial land uses were evaluated. For future residential use,
direct contact with soils and sediments were evaluated, in
addition to potential inhalation exposures. For future
industrial land-use conditions, both direct contact and
inhalation exposures were also evaluated.
In order to assess these exposures, detected concentrations
from sampling or, in the case of volatilization of contaminants,
contaminant transport modeling was used to estimate the
concentration at the exposure point.
Chronic daily intakes (GDIs) to humans were estimated by
using the exposure point concentrations and exposure parameters
(such as soil ingestion rates and frequency of exposure)
available from EPA or assumed based on reasonable assumptions
about potential site uses. Potential exposures were estimated
using average parameters and geometric mean concentrations of
chemicals to derive an average case exposure; the maximum
concentration and higher exposure parameters were used to
calculate a maximum plausible case exposure. Maximum
concentrations were used in cases where mean concentrations were
not available.
Excess lifetime cancer risks were estimated for each
exposure case using GDIs and chemical-specific cancer potency
factors. A cancer risk level of 1 x 10~7, the lowest end of the
risk range that EPA considers protective of human health, was
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used as a benchmark for comparison to the estimated cancer risk
levels. Potential risks of noncarcinogenic health effects were
estimated by comparing the GDIs to the reference doses (RfDs).
The hazard index (HI) is the sum of the CDIrRfD ratios for all
the chemicals evaluated in a given area. In general, hazard
indices which are less than one are not likely to be associated
with any health risks.
RISK ASSESSMENT RESULTS
The results of the risk assessment indicate that
concentrations of contaminants in soil and sediment at several
locations on and adjacent to the site result in excess lifetime
cancer risks as high as 7 x 10~5 for current land use and 1 x
10~3 for future residential land use. The estimated risks of
cancer and noncarcinogenic risks are summarized by land use and
exposure pathway in Attachment B.
The EPA has determined that actual or threatened releases of
hazardous substances from this site, if not addressed by remedial
action, may present a current or potential threat to public
health, welfare, or the environment.
11
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8.0 DESCRIPTION OF ALTERNATIVES
The remedial alternatives evaluated in detail in the OUFS
report are described below. This description identifies
engineering components, institutional controls, implementation
requirements, estimated costs, and major applicable or relevant
and appropriate requirements (ARARs) associated with each option.
8.1 NO ACTION
As required by the National Contingency Plan, the no action
alternative was evaluated. This alternative provides a baseline
for comparing the effectiveness of the other remedial
alternatives. Under this option, no further action would be
taken to prevent exposure to contaminated soil and sediment or
migration of contamination from the site. The site would remain
in its present condition. There would be no costs associated
with this alternative.
8.2 EXCAVATION AND ONSITE INCINERATION
This alternative would include the excavation and thermal
treatment of approximately 4,050 cubic yards of contaminated soil
and sediment. The amount of contaminated material to be
excavated was determined by calculating protective soil
contaminant concentrations based on the maximum case exposure
conditions for future residential use of the site for a cancer
risk level of 1 x 10~5. A more detailed discussion regarding the
determination of protective soil concentrations is provided in
Section 10.2. Areas requiring excavation are identified in
Figure C-l in Attachment C.
Soil and sediment with contaminant concentrations above the
protective soil concentrations would be excavated using
conventional earthmoving equipment then thermally treated in an
onsite mobile incinerator. Engineering controls such as dust
suppressants and berms would be implemented during excavation to
minimize fugitive dust and surface runoff.
Soil sampling would be conducted to confirm that the
horizontal and vertical extent of excavation was sufficient to
remove contamination above cleanup levels. Following excavation,
clean soil would be placed in the excavated areas, compacted and
graded. Vegetation or gravel would be applied to minimize
erosion.
Additional site activities would include site preparation
for the mobile incinerator and onsite assembly of the incinerator
and material handling equipment. Operation of the unit would
include safety and emissions control equipment. Completion of
remediation activities would include demobilization of the
12
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incineration facility, decontamination and removal of temporary
structures, equipment, etc., and regrading and seeding.
This alternative would comply with the Resource Conservation
and Recovery Act (RCRA) requirements and technical standards of
40 CFR Part 264. Residual ash would be delisted as a hazardous
waste to allow disposal in a sanitary landfill offsite. The
alternative would comply with the Clean Air Act and Occupational
Safety and Health Administration (OSHA) requirements. State
requirements would include the Missouri Air Conservation Law,
Missouri Air Pollution Control Regulations, and the Missouri Air
Quality Standards.
The estimated time to implement this alternative was
approximately 27 months which includes 5 months for excavation
and incineration and 12 for delisting. The present worth cost
for this option, revised based on additional information
presented during the public comment period, was estimated at
approximately $7.6 million.
8.3 EXCAVATION AND OFFSITE INCINERATION
An offsite permitted hazardous waste incineration facility
would be used to thermally treat the 4,050 cubic yards of
contaminated soil and sediment. Excavation and restoration
activities would be performed as previously described.
As required by commercial facilities, contaminated soil
would be placed in fiber drums and transported in 15-20 cubic
yard trucks to the offsite incinerator. The exterior of trucks
would be decontaminated prior to leaving the site. Waste
manifests would accompany the waste shipments. Following
incineration, residual ash would be disposed of by the offsite
treatment facility.
The offsite transportation of hazardous materials would
comply with Department of Transportation (DOT) and RCRA Part 263
requirements. OSHA requirements for the protection of workers
would be met. The offsite RCRA facility must be in compliance
with the CERCLA offsite policy.
The time required to implement this alternative was
estimated to be 11-29 months. The variability is due to the
availability and capacity of the offsite incinerator. The
present worth cost for this alternative was estimated to be
approximately $16.5 million.
8.4 EXCAVATION AND ONSITE LANDFILL
A RCRA hazardous waste landfill would be constructed onsite
to dispose of the 4,050 cubic yards of contaminated material. As
required by RCRA, the unit would be constructed above grade to
13
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maintain a separation of at least 10 feet between the bottom of
the landfill and the shallow ground water at the site. Excavation
and restoration would be performed as previously described.
The major landfill components would include a multiliner
system, a leachate collection and removal system, and a RCRA
multilayer cap. Post-closure activities would include semi-
annual inspections, cap maintenance, and ground water monitoring.
Land and ground water use restrictions would also be required
for the onsite landfill facility.
This alternative would comply with the land disposal
restrictions of RCRA Part 268 since placement of a RCRA listed
waste would occur. The onsite landfill would comply with the
technical standards and post-closure requirements of RCRA Part
264 and Missouri Hazardous Waste Management Law and Rules. OSHA
requirements for the protection of workers would be met.
The estimated time required to implement this alternative
was approximately 16-18 months. The present worth cost was
estimated to be approximately $2.5 million.
8.5 EXCAVATION AND OFFSITE LANDFILL
This alternative would involve the excavation of the 4,050
cubic yards of contaminated material and transportation to a
RCRA-approved commercial hazardous waste landfill. Excavation
and restoration would be performed as previously described.
Contaminated material would be transported to the offsite
facility in bulk shipments by covered trucks with capacity to
hold up to 22 tons. The exterior of the trucks would be
decontaminated prior to leaving the site. Waste manifests would
accompany the waste shipments.
The offsite landfill facility must meet the RCRA technology
requirements for land disposal which include double liner,
leachate detection and collection system and ground-water
monitoring.
This alternative must comply with the land disposal
restrictions of RCRA Part 268 since placement of a RCRA-listed
waste would occur. The transportation of hazardous waste must
comply with DOT and RCRA Part 263 requirements. OSHA
requirements for the protection of workers, and the Missouri
Hazardous Waste Management Law and Rules would be met. The
offsite facility must be in compliance with the CERCLA offsite
policy.
The time required to implement this alternative was
estimated to be 7-9 months. The estimated present worth cost was
approximately $2.6 million.
14
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8.6 EXCAVATION AND CAPPING
This alternative would include excavation of approximately
1,130 cubic yards of contaminated material (offsite drainage
channel and soil along the south-southeast portion of the site)
and consolidation onsite. A RCRA multilayer cap (compacted clay,
synthetic membrane, drainage layer and vegetative layer) would be
placed over the consolidated material and other areas where the
levels of contaminants exceed protective soil concentrations.
The cap would extend over some areas which do not exceed cleanup
levels to facilitate drainage and divert surface water.
Following construction of the cap, vegetation would be
established to prevent erosion. Long-term maintenance and
monitoring would be required. Semiannual inspections, monthly
maintenance and ground water monitoring would be performed. Land
and ground water use restrictions would also be required.
This alternative would comply with RCRA landfill closure
requirements in Part 264. OSHA requirements for worker
protection would also be met.
The time required to implement this alternative was
estimated to be approximately 12 months. The present worth cost
was estimated at approximately $1.1 million.
15
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9.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
Nine evaluation criteria have been developed by EPA to
address CERCLA statutory requirements and technical, cost, and
institutional considerations. The evaluation criteria serve as
the basis for selecting an appropriate remedial action. The
remedial alternatives developed and evaluated in the OUFS are
described below in relation to the evaluation criteria.
9.1 OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
With the exception of the no-action alternative, all the
alternatives provide protection of human health and the
environment by removing, reducing, or controlling risk through
treatment, engineering controls, or institutional controls. The
no-action alternative will not be discussed further since it is
not protective of human health and the environment.
Both onsite and offsite thermal treatment offer the same
level of protection. Risks posed by contaminated soil and
sediment above protective soil concentrations would be
permanently eliminated by destruction of contaminants through
incineration.
The offsite landfill alternative would eliminate risks at
the site by the excavation and removal of contaminated soil and
sediment to a RCRA-approved offsite hazardous waste landfill.
The offsite landfill, through containment, would reduce risks
posed by the contaminated material by reducing the potential for
contaminant migration and direct contact with or inhalation of
contaminants. RCRA technical requirements for the landfill
facility include double liner, leachate detection and collection
system and monitoring.
The onsite landfill and capping alternatives would not
eliminate risks at the site, but would reduce risks by reducing
the potential for contaminant migration and direct contact with
or inhalation of contaminants through containment. Long-term
management, which would include site inspections, maintenance and
monitoring, would be required for both alternatives. Land and
ground water use restrictions would also be required.
9.2 COMPLIANCE WITH ARARS
Contaminant-specific ARARs with regard to soil have not been
promulgated and no location-specific ARARs were identified. As
discussed in the Section 8.0, the alternatives would comply with
federal and state action-specific ARARs.
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The thermal treatment alternatives would comply with RCRA
Part 264 requirements and technical standards. Additional ARARs
would include the Clean Air Act and Missouri Air,Pollution
Control Regulations.
The alternatives which include offsite transportation would
comply with RCRA Parts 262 and 263, and DOT requirements. The
land disposal alternatives would be required to comply with the
requirements and technical standards of RCRA Parts 264 and 268.
9.3 LONG-TERM EFFECTIVENESS AND PERMANENCE
The thermal treatment alternatives would permanently
eliminate risks associated with the contaminated soil and
sediment. Both alternatives would require no long-term
management or institutional controls at the site.
The removal of contaminated soil and sediment to a RCRA-
approved hazardous waste landfill would eliminate long-term risks
at the site. Containment provided by an offsite facility meeting
the technical requirements for double liner, leachate detection
and collection and monitoring would provide a high degree of
long-term effectiveness for contaminated soil with the
concentrations detected at this site. In addition, containment
at an offsite facility would reduce the volume of contaminated
material at the site and provide an overall reduction in
mobility. The offsite landfill alternative would also not require
long-term management or institutional controls at the site.
Containment of contaminated soil and sediment provided by
the onsite landfill alternative and by the capping option may
reduce but would not eliminate long-term risks at the site. The
onsite landfill would provide an overall reduction in mobility
through containment. Both alternatives would require long-term
management including maintenance and ground water monitoring.
Land and ground water use controls would also be required for the
life of both alternatives. The capping alternative does not
completely address potential threats posed by contaminated
subsurface soils to the ground water; the potential for future
release and exposure would have to be considered.
»
9.4 REDUCTION OF TOXICITY, MOBILITY, OR VOLUME
This criteria addresses the degree to which alternatives
employ treatment which reduce toxicity, mobility, or volume.
Only the incineration alternatives utilize treatment to reduce
toxicity, mobility, or volume.
As described above, both the offsite and onsite landfill
alternatives provide an overall reduction in mobility through
containment.
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9.5 SHORT-TERM EFFECTIVENESS
All the alternatives would present similar short-term risks
to workers and the community during excavation and soil handling
operations. Potential exposures to fugitive emissions and
surface runoff can be effectively minimized and controlled by
implementing engineering controls (dust suppressants, berms,
etc.) and complying with action-specific ARARs.
The thermal treatment alternatives involve additional risks
and impacts associated with potential malfunctions during
operation or incomplete destruction of contaminants resulting in
releases of hazardous emissions. Implementation of engineering
controls and compliance with ARARs would effectively minimize and
control potential risks and impacts.
The two offsite alternatives involve additional risks and
impacts associated with offsite transport. Again, implementation
of engineering controls and compliance with ARARs would
effectively minimize and control potential risks and impacts.
The alternatives vary considerably in the length of time
required to implement the remedial action. The offsite landfill
alternative would require approximately 7-9 months. Capping"
would take 12 months and onsite disposal would require 16-18
months. Offsite incineration was estimated to take from 11-29
months, and onsite incineration would require about 27 months.
Alternatives requiring a longer period of time to implement have
a greater opportunity for short term impacts.
9.6 IMPLEMENTABILITY
Implementation of the offsite landfill alternative would
involve conventional construction technologies. Operation and
maintenance and monitoring following implementation of the remedy
would not be required at the site. Future remedial actions, if
required, would not be difficult to implement. The number and
capacity of commercial landfills which are permitted to receive
hazardous waste is limited, but four facilities currently in
compliance were identified in the OUFS.
Onsite disposal and capping would also employ conventional
construction technologies. Construction of the cap around the
building and securing the cap to the structure would, however, be
more technically complex. Implementation would be labor
intensive for both alternatives. Site inspections, maintenance
and ground water monitoring following implementation of the
remedy would be required for both alternatives. Since onsite
landfill and capping would require institutional controls for the
life of the remedy, coordination requirements between local,
county and state and federal agencies would be increased. For
the capping alternative, the implementation of future remedial
18
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actions would be more difficult, especially for remedies
addressing potential impacts on ground water by the contaminated
subsurface soils.
The thermal treatment alternatives would be complex to
implement. The capacity and availability of offsite commercial
or mobile incinerators could be limited; facilities currently
available were identified in the OUFS. Operation and maintenance
at the site and institutional controls would not be required
following completion of thermal treatment. Future remedial
actions, if required, would not be difficult to implement.
9.7 COST
The capping alternative was estimated to be the least costly
at $1.1 million. The cost for onsite landfill was estimated at
$2.5 million. The offsite landfill alternative was estimated at
$2.6 million. The estimated costs for the thermal treatment
alternatives were the highest. The revised cost estimate for
onsite thermal treatment was $7.6 million; offsite incineration
was estimated to cost approximately $16.5 million.
9.8 STATE ACCEPTANCE
In a letter of concurrence, the State of Missouri supported
the offsite RCRA-approved hazardous waste landfill alternative.
9.9 COMMUNITY ACCEPTANCE
During the public comment period, the Agency received three
written comments from the community addressing the remedial
alternatives. Two residents expressed support for the offsite
landfill alternative and the PRPs supported the capping
alternative.
Responses to all comments received during the public comment
period are provided in the Responsiveness Summary, a component of
the Record of Decision.
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10.0 SELECTED REMEDY
Based upon an evaluation of the relative performance of each
alternative with respect to the evaluation criteria, and
consideration of comments received during the public comment
period, both EPA and the State of Missouri have determined that
excavation and offsite landfill is the most appropriate remedy
for contaminated soil and sediment at the Kern-Pest site.
1O.1 DESCRIPTION
Approximately 4,050 cubic yards of contaminated soil and
sediment would be excavated and transported to a RCRA-approved
commercial hazardous waste landfill for disposal. The offsite
landfill facility would provide long-term management through
double liner containment, a leachate detection and collection
system and monitoring.
Sampling would be conducted to confirm that the horizontal
and vertical extent of excavation was sufficient to remove
contamination above the health-based cleanup goals. Following
excavation, clean soil would be placed in the excavated areas,
compacted and graded. Vegetation or gravel would then be applied
to minimize erosion.
Since this remedy will not result in hazardous substances
remaining onsite above health-based levels, environmental
monitoring, security, and operation and maintenance would not be
required for soils and sediments after remedial activities are
completed.
The time required to implement this remedy was estimated to
be approximately 7-9 months. The estimated present worth cost
was estimated at approximately $2.6 million. The major cost
components are transportation at $671,000 and disposal at
$853,000. Capital costs for each major component and indirect
costs are summarized in Table D-l in Attachment D.
10.2 REMEDIATION GOALS
The objectives of this first operable unit are to remove or
reduce to a protective level the risks posed by dermal contact,
ingestion or inhalation of contaminated soil and sediment, to
eliminate or reduce the potential for offsite transport of
contaminated material, which includes reducing the threats posed
by contaminated subsurface soils on ground water, and to
remediate contaminated soil and sediment in a manner which will
not adversely affect future remedial actions, if required.
20
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A risk assessment was conducted to evaluate the potential
impacts to human health for current and future land use
scenarios. The results of the risk assessment indicate that
concentrations of contaminants in soil and sediment at several
locations on and adjacent to the site result in excess lifetime
cancer risks as high as 7 x 10~5 for current land use and 1 x
10"3 for future residential land use.
There are no federal or state standards for soil
contamination. When a health-based standard does not exist, EPA
considers a range of 10""4 to 10~7 individual lifetime excess
cancer risk to be protective of human health. The 10~6 level is
generally used as the point of departure for establishing cleanup
levels.
Protective contaminant concentrations for soil at 1 x 10~6,
1 x 10~5, and 1 x 10~4 were determined for chemicals of concern
at the site. These concentrations were calculated using risk
assessment techniques that combine scenario-specific exposure
parameters with an estimated protective chronic daily intake
(GDI) for each chemical of concern. The protective contaminant
concentrations for the three cancer risk levels for both surface
soil and subsurface soil exposures are provided in Tables D-2 and
D-3 in Attachment D.
The protective soil concentrations for the maximum case at
the 10~5 cancer risk level were determined to represent a
reasonable maximum exposure scenario.
Reasonable maximum exposure scenario reflects a situation
which is more conservative than an average case but is not the
absolute worst case scenario. The maximum case soil
concentrations for the 10~5 cancer risk level fall between the
concentration range established be the average case and maximum
case for the 10~6 cancer risk level. As explained in Agency
guidance, the reasonable maximum exposure scenario is developed
to reflect the types and extent of exposures that could occur,
based on the likely or expected use of the site in the future.
The EPA has therefore determined that removing contaminated
soil and sediment to the contaminant concentrations for the 10~5
risk level will reduce potential exposures to protective levels.
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11.0 STATUTORY DETERMINATIONS
Section 121 of CERCLA establishes statutory requirements and
preferences for remedial actions. These specify that when
complete, the selected remedy must be protective of human health
and the environment, comply with applicable or relevant and
appropriate federal and state requirements, be cost-effective and
utilize permanent solutions and alternative treatment
technologies or resource recovery technologies to the maximum
extent practicable.
In addition, the statute includes a preference for remedies
which employ treatment that permanently and significantly reduce
the volume, toxicity, or mobility of hazardous wastes as their
principal element. This section discusses how the selected
remedy meets these statutory requirements.
PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
The selected remedy will eliminate risks at the site by the
excavation and removal of contaminated soil and sediment to a
RCRA-approved offsite hazardous waste landfill. The offsite
landfill, through containment, will reduce risks posed by the
contaminated material be reducing the potential for contaminant
migration and direct contact with or inhalation of contaminants.
The landfill facility will provide secure containment by meeting
RCRA technical requirements which include double liner, leachate
detection and collection system and monitoring.
The RI risk assessment concluded that concentrations of
contaminants in soil and sediment at several locations on and
adjacent to the site result in excess lifetime cancer risks as
high as 7 x 10~5 for current land use and 1 x 10~3 for future
residential land use.
By excavation and removal of contaminated soil and sediment
to protective contaminant concentrations, cancer risks will be
reduced to 1 x 10~5. This cancer risk level represents a
reasonable maximum exposure scenario and is within the range 10"4
to 10~7 individual lifetime excess cancer risk considered
protective of human health.
There are no short-term threats associated with the selected
remedy that cannot be controlled by implementing engineering
controls and complying with ARARs. No adverse cross-media
impacts are expected from this remedy.
COMPLIANCE WITH ARARS
The selected remedy complies with federal and state
requirements that are applicable or relevant and appropriate to
22
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the operable unit. Contaminant-specific ARARs with regard to
soil have not been promulgated and no location-specific ARARs
were identified. Action-specific ARARs include:
RCRA 40 CFR Part 262 - Standards applicable to generators of
hazardous waste.
RCRA 40 CFR Part 263 - Standards applicable to transporters of
hazardous waste.
RCRA 40 CFR Part 264 - Standards for owners and operators of
hazardous waste treatment, storage, and disposal facilities.
RCRA 40 CFR Part 268 - Land Disposal Restrictions.
OSHA 40 CFR Sect. 300.38 - Worker health and safety.
Hazardous Materials Transportation Regulations 40 CFR Parts 107,
171-177.
CERCLA Offsite Disposal Policy
Missouri Hazardous Waste Management Law and Rules
Other criteria, advisories or guidance to be considered for
this remedial action include the protective soil concentrations
for soil and sediment based on the risk assessment scenarios
developed in the public health evaluation.
COST-EFFECTIVENESS
The selected remedy is cost-effective because it has been
determined to provide overall effectiveness proportional to its
costs, estimated at $2.6 million. Regarding the least costly
alternative, capping, the selected remedy is cost-effective when
the overall relationship between cost and effectiveness is
compared to the cost/effectiveness relationship of capping. The
selected remedy assures a higher degree of certainty that the
remedy will be effective in the long-term. Capping would require
long-term management at the site and institutional controls. In
addition, capping would not address potential threats posed by
the impact of contaminated subsurface soils on the ground water.
Based on the concentrations of hazardous substances in the
soil and sediment detected at this site, thermal treatment of
soils would result in long-term effectiveness similar to that
afforded by containment at a RCRA-approved hazardous waste
landfill.
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UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT
TECHNOLOGIES (OR RESOURCE RECOVERY TECHNOLOGIES) TO THE MAXIMUM
EXTENT PRACTICABLE
EPA has determined that the selected remedy represents the
maximum extent to which permanent solutions and treatment
technologies can be utilized in a cost-effective manner. Of
those alternatives that are protective of human health and the
environment and comply with ARARs, EPA has determined that the
selected remedy provides the best balance of tradeoffs in terms
of long-term effectiveness and permanence, reduction in toxicity,
mobility, or volume achieved through treatment, short-term
effectiveness, implementability, cost and considering State and
community acceptance.
The selected remedy provides a higher degree of long-term
effectiveness and permanence than the onsite landfill or capping
alternative. The selected remedy would require no long-term
management or institutional controls at the site. In addition,
capping would not completely address potential threats posed by
contaminated subsurface soils to ground water; the potential for
future release and exposure would have to be considered.
Containment provided by an offsite facility meeting the technical
requirements for double liner, leachate detection and collection
and monitoring would provide a high degree of long-term
effectiveness for contaminated soil with concentrations above
health-based standards but not at significantly high
concentrations. The selected remedy would therefore result in a
similar degree of long-term effectiveness that would be provided
by the thermal treatment of soils with these concentrations.
The selected remedy reduces both the volume and mobility of
contaminated soil and sediment located at the site. The
contaminated material removed from the site would be effectively
contained as described above. The capping alternative would not
reduce the volume of contaminated material on the site and the
mobility of contaminants in the subsurface soil would remain a
concern.
The selected remedy is more effective than the other
alternatives in the short-term, requiring only 7-9 months to
implement as compared to a year for capping, 16-18 months for
onsite landfill, 11-29 months for offsite incineration and 27
months for onsite incineration. Alternatives requiring a longer
period of time to implement have a greater opportunity for short
term impacts.
The selected remedy is significantly less costly than the
onsite and offsite incineration alternatives, and is comparable
to the onsite disposal option.
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With respect to implementability, the selected remedy will
involve conventional construction technologies and will have
fewer technical difficulties associated with implementation. The
thermal treatment alternatives are technically complex to
implement. Capping will be difficult to implement due to the
need to construct the cap around the building and secure the cap
to the structure. Future remedial actions, if required, would
not be difficult to implement, as opposed to capping. With
respect to administrative feasibility, the selected remedy will
not require long-term management or institutional controls at the
site. Both the onsite landfill and capping alternatives would
require long-term management and institutional controls,
increasing the complexity of coordination with local, county,
state and federal agencies.
The selected remedy would utilize permanent solutions and
alternative treatment technologies to the maximum extent
practicable. Treatment is usually practicable for wastes which
cannot be reliably contained or controlled in place such as
liquids, highly mobile materials such as solvents, and high
concentrations of toxic compounds. The wastes at the Kern-Pest
site are soils and sediments with concentrations above health-
based levels, but not at high concentration levels. Also, the
principal contaminants at the site, pesticides, have a high
affinity for attachment to soil particles and could be reliably
contained by a hazardous waste landfill facility meeting the RCRA
technical requirements which include double liner, leachate
detection and collection system and monitoring. Offsite disposal
in a RCRA-approved hazardous waste landfill would provide similar
long-term effectiveness at substantially less cost than thermal
treatment. Other potential treatment technologies were
determined not to be feasible since contaminants and soil types
present at the site were not amenable to physical or chemical
treatment technologies. For these reasons, treatment is not
practicable at the Kern-Pest site.
The selected remedy was supported by the State of Missouri.
The State indicated that capping was the least preferred
alternative due to concerns regarding the potential impact of
contaminated subsurface soil on the ground water. With respect
to community acceptance, two residents expressed support for the
offsite landfill alternative and the PRPs favored capping.
PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
This remedy utilizes permanent solutions and alternative
treatment technologies to the maximum extent practicable for this
site. However, because treatment of the principal threats of
contaminated soil and sediment was not found to be practicable,
as explained above, this remedy does not include treatment as a
principal element for this first operable unit.
25
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RECORD OF DECISION
DECISION SUMMARY DOCUMENT
ATTACHMENTS
26
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ATTACHMENT A
SAMPLE RESULTS SUMMARY TABLES
SAMPLE LOCATION FIGURES
27
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TABLE A-l
Summary of Chemicals Detected In the
Subsurface Soil Samples from the Former Laooon Area at the Kern-Pest Laboratories Site
(Organics-ug/kg. Inorganics-ing/kg)
Chemical
LAGOON 1.5-9 FEET
Organic*:
•cetone
aldMn
'alpha-BHC
benzene
beta-BHC
bis(2-ethy!hexyl)phthalate
2-butanone
carbon dtsulflde
chlordane
chloro benzene
chloroform
DOT
delta-BHC
3.3 '-dichlorobenzidine
1.1-dlchloroethane
1.2-dichloroethane
2. 4-d Ich loropheno 1
2 , 4-d imethy Iphenb 1
dieldrin
- endrin
endrln ketone
endosulfans I and II
- ethylbenzene
gamma-bhc
neptachlor
heptachlor epoxlde
hexach lorobutad i ene
methoxychlor
methylene chloride
2-methylphenol
n-Nitrosodiphenylamine
ncpah
pentach loropheno 1
toluene
1.1.1-tHchloroethane
2.4. 5-tr ich loropheno 1
xylene (total)
Inorganics:
aluminum
• arsenic
barium
beryl Hun
cadmium
calcium
chromium
cobalt
copper
Iron
lead
Magnesium
manganese
nickel
potassium
•elenlum
sodium
thallium
'vanadium
_ Zinc
Frequency of
Detection (a)
4/8
6/14
1/9
2/8
1/6
3/7
1/5
1/8
10/14
2/8
2/8
2/13
1/6
1/7
1/8
3/8
4/7
1/7
6/11
8/13
5/12
1/13
3/8
1/7
7/14
2/7
1/7
1/7
2/2
• 1/2
2/7
2/7
3/7
2/8
1/8
1/1
3/8
7/7
6/7
7/7
5/7
3/7
7/7
7/7
6/7
4/7
7/7
7/7
7/7
7/7
7/7
7/7
2/5
3/3
1/2
7/7
7/7
Geometric
Mean
32.0
89.7
16.9
5.5
6.8
528.5
8.2
3.1
1.102.5
5.4
7.6
178.2
5.8
684.8
3.3
7.3
1.019.2
419.9
90.2
146.4
68.8
342.7
20.4
7.5
261.0
7.8
453.6
65.8
1.6
246.6
478.3
1,023.9
2.785.2
5.3
3.4
NA
29.1
11.821.4
17.9
199.9
0.48
0.9
2.857.5
19.4
10.3
16.0
20.785.8
15.0
3.472.1
774.0
24.3
923.3
0.61
169.9
1.17
28.4
73.7
Maximum
Detected
300.0 J
3.500.0
750.0 J
67.0
23.8 J
2.698.1
27.0 J
4.0 J
74,500.0
120.0
150.0 J
8.490.0
9.4 J
950.0 J
6.0 J
87.0
8,600.0
680.0
1.800.0 J
14.000.0
1.300.0 J
104.800.0
1.700.0
11.0
45.700.0
38.0 J
3.500.0
320.0 J
2.4 J
320.0 J
4.400.0
9.900.0
19.000.0
37.0
9.0 J
260.0 J
11.000.0
16.000.0
160.0
300.0
1.0 M
4.3
4,500.0
29.0
18.0
37.0
31.000.0
23.0 J
4.600.0
1.200.0
48.0
1.500.0
.8 *
250.0 M
1.2 M
48.0
110.0
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TABLE A-l (cont.)
Summary of Chemicals Detected In the
Subsurface Soil Samples front the Former Ugoon Area at the Kern-Pest Laboratories Site
(Organics-ug/kg, Inorganics-ng/kg)
Chemical
UGOON >9 FEET
Organ (cs:
•cetone
aldrin
alpha-BHC
benzene
bis(2-ethy1hexyl)phtha1ate
carbon disulfide
chlordane
chlorobenzene
chloroform
DOT
delta-BHC
1 . 1-dichloroethane
1,2-dichloroethane
2,4-dichlorophenol
dleldrin
endrln
endrin ketone
ethylbenzene
gama-BHC
heptachlor
methoxychlor
methylene chloride
pentach loropheno 1
toluene
2 , 4 . 5-tr ich loropheno 1
xylene (total)
Inorganics:
aluminum
" arsenic
barium
beryllium
cadmium
calcium
chromium
cobalt
copper
i ron
lead
magnesium
manganese
nickel
potassium
selenium
sodium
vanadium
Zinc
Frequency of
Detection (a)
3/5
9/12
3/10
2/5
2/6
1/5
10/12
4/5
3/5
1/12
1/8
3/5
5/5
5/6
6/12
5/12
3/12
3/5
4/10
10/12
2/9
2/2
2/6
1/5
1/1
3/5
6/6
4/6
6/6
6/6
1/6
6/6
6/6
6/6
6/6
6/6
6/6
6/6
6/6
6/6
6/6
3/6
5/5
6/6
6/6
Geometric
Mean
20.4
16.5
8.1
5.5
524.2
3.6
228.2
9.3
18.4
60.6
6.3
3.1
90.5
1.066.8
29.1
36.7
24.7
23.3
13.3
112.9
82.2
2.5
NR
5.4
NA
65.1
11.916.1
8.2
240.2
0.7
0.8
8.807.2
20.6
15.1
25.5
23.804.0
14.0
6.326.2
1.542.8
34.9
1.425.0
0.6
202.3
30.1
84.4
Maximum
Detected
24.0 J
130.0 J
13.0 J
15.0 J
2,400.0
5.0 J
5.360.0 J
14.0
210.0 J
43.5 J
14.0 J
5.0 J
700.0 J .
6,900.0
130.0
1.300.0 J
370.0 J
5.000.0 J
68.0
14,000.0
240.0
3.0 J
400.0 J
36.0 J
470.0 J
28.000.0 J
14.000.0
23.0
390.0
1.2 J
1.9
31.000.0
23.0
29.0
35.0
33.000.0
30.0 J
11.000.0
4.700.0 J
45.0
2.300.0
0.6 M
230.0 M
41.0
110.0
Motes:
J • Estimated value.
M « Chemical Mas detected at level below CRQl; similar to J value.
NA • Not applicable since only one sample.
NR - The geometric man was not reported (NR). as this concentration was greater than the maximum
detected value (as a result of Including detection limits that exceeded two times the
maximum detected value In calculating the geometric mean).
(a) The number of samples In which the contaminant was detected divided by the total number of
samples analyzed. In determining the frequency of detected, samples flagged with an "R"
(rejected) were not Included.
. * • Selected as chemical of potential concern for the risk assessment.
-------
TABLE A-2
Summary of Chemicals Detected 1n Surface
Soils «t the Kern-Pest laboratories Site Based on Composite Samples (d)
(ug/kg)
Area/Chemical
GRIDS 1-4
Organ ics:
aldrin
chlordane
DDT
dieldrin
endosulfan sulfate
endrin
heptachlor
heptachlor epoxide
GRID S
Organ ics:
chlordane
dieldrin
heptachlor
heptachlor epaxide
toxaphene
GRID 6
Organ ics:
beta-SHC
chlordane
DOT
difldrin
endrin ketone
heptachlor
heptachlor epoxide
GRID 7
Organ ics:
chlordane
DDT
dieldrin
endrin ketone
heptachlor
heptachlor epoxide
GRID 8
Organ ics:
chlordane
DOT
dieldrin
endosulfan sulfate
endrin ketone
heptachlor
heptachlor epoxide
Frequency of
Detection (a)
1/4
4/4
3/4
4/4
4/4
1/4
4/4
4/4
-
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1 .
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
Geometric
Mean
NR
14.6
29.0
6.3
4.1
NR
3.1
10.2
NA
NA
NA
NA
. NA
NA
NA
NA
NA
NA
NA
NA
•
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Maximum
Detected
0.9 J
29.9 J
29.4 J
17.0 J
6.8 J
7.1 J
6..1 J
38.0
4.930.0
290.0
2.600.0
620.0
46.000.0
2.2 J
27.0 J
121.0 J
23.0
60.0
31.0
7.3 J
39.000.0 J
41.950.0
58.000.0
2,100.0 J
22.000.0
600.0 J
24.000.0 J
985.0 J
3.200.0
66.0 J
130.0 J
12.000.0
2,600.0
-------
TABLE A-2 (cont.)
Sunroary of Chemicals Detected in Surface
Soils at the Kern-Pest Laboratories Site Based on CannesUe Samples (d)
(ug/kg)
Area/
Chemical
"GRIDS IA-
-------
TABLE A-3
Summary of Chemicals Detected in Surface
Soils at the Kern-Pest Laboratories Site Based on Discrete Sampling Locations
(Organics-ug/kg. Inorganics-mg/kg)
Location/Chemical
Frequency of
Detection (a)
Geometric
Mean
Maximum
Detected
BARE AREA (in Grid 8)
Organics:
• Idrin
chlordane
DDT
dieldrin
heptachlor
heptachlor epoxide
nethylene chloride
Inorganics:
aluminum
barium
calcium
chromium
iron
lead
magnesium
manganese
nickel
potassium
vanadium
Zinc
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
12
33 J
128
32
36
300
5.0 J
.0 J
8.100.0
72.0
1.100.
13.0
13.000.0
49.0 J.
1.600.0
320.0 J
14.0
750.0 J
20.0
110.0
BURNT AREA (in Grid 8)
Organics:
acetone
aldrin
beta-BHC
chlordane
DDT
dieldrin
endosulfan II
endrin
endrin ketone
heptachlor
heptachlor epoxide
methoxychlor
methylene chloride
Inorganics:
aluminum
• arsenic
barium
calcium
chromium
cobalt
iron
* lead
magnesium
manganese
nickel
potassium
vanadium
Zinc
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
2.0 J
.900
260
761
.480
.600
130
.100
.300
180
100
.300
2.0 J
.700.0
170.0 J
83
.900
11
0
0 J
0
0 J
11.000.0
110.0 J
1.400.0
680.0 J
12.0
580.0 J
17.0
75.0
-------
TABLE A-3 (cont.)
Sunroary of Chemicals Detected In Surface
Soils «t the Kern-Pest Laboratories Site Based on Discrete Sampling Locations
(Organics-ug/kg,.Inarganics-mg/kg)
Location/
Chemical
SCRAP PILE (In Grid 6)
Organ ics:
chlordane
DDT
dieldrin
•ndrin
endrin ketone
heptachlor
heptachlor epoxlde
'Inorganics:
aluminum
barium
. calcium
chromium
cobalt
iron
lead .
magnesium
manganese
nickel
potassium
vanadium
zinc
STORAGE TANKS (in Grid 4)
Organ ics:
acetone
bis(2-ethy1hexy1)phthalate
• di-n-butylphthalate
• ethylbenzene
* heptachlor
methylene chloride
• xylene (total)
Inorganics:
aluminum
barium
calcium
chromium
cobalt
iron
lead
magnesium
manganese
nickel
potassium
vanadium
zinc
Frequency of
Detection (a)
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
2/2
1/3
1/3
1/3
2/2
1/3
3/3
3/3
3/3
3/3
2/3
3/3
3/3
3/3
3/3
3/3
3/3 '
3/3
3/3
Geometric
Mean
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
106.3
626.6
14.2
5.3
2.4
38.2
6.878.1
161.0
1.924.2
12.0
7.5
6.981.2
10.2
1,181.4
980.9
15.0
645.1
18.5
40.6
Maximum
Detected
648
17
62
68
160
50
510
7.400.0
150.0
1.700.0 J
12.0
11.0 J
9.500.0
12.0 J
1.100.0 J
1.900.0 J
17.0
630.0 J
19.0
56.0
3.0 J
130.0 J
1.500.0
360.0 J
9.3
2.8 J
5.900.0
7.703.2
290.0
2.700.0 J
12.0
9.8 J
9.697.9
11.0 J
1.249.0 J
1.179.8 J
16.0
700.0 J
19.0
42.0
Motes:
J • Estimated Value
NA • Not applicable since only one sample.
(a) The number of samples in which the contaminant «as detected di
samples analyzed. In determining the frscuir.cy of detection.
of "I" (Invalid) were net included.
* • Selected as a chemical of potential car.-;:- ;- the risk *ur
:d by the total number of
"es Kith a data qualifier
-------
TABLE A-4
Surmary of Chemicals Detected In the
Orlinage Channel Sediments at the Kern-Pest Laboratories Site (b)
(ug/kg) .
hemical
rganics:
aldrln
alpha-BHC
beta-BHC '
chlordane
DOT
dieldrln
endosulfans I tnd II
endosulfan sulfate
endrin
endrin ketone
gamma -8HC
heptachlor
heptachlor epoxide
wethoxychlor
Frequency of
Detection (a)
40/48
2/25
2/23
47/48
38/48
40/48
9/46
1/21
40/48
27/47
7/23
44/48
43/48
4/38
Geometric
Mean
114.1
5.4
5.2
1114.7
314.2
280.0
252.5
7.3
196.0
63.1
4.0
345.8
136.3
121.3
Kaxlmun
Detected
58. 000.0
24.0
19.0 J
45.900.0
44.490.0
34.000.0
4.600.0 J
21.0
11.000.0 J
4,500.0 J
21.0
240.000.0
2.800.0
2.100.0 J
Notes:
J - Estimated value.
NA • Not applicable since only one sample.
,NR • The geometric mean was not reported (NR), as this concentration was greater than the maxinum
detected value (as a result of including detection limits that exceeded two times the
maximum detected value tn calculating the geometric mean).
(a) The number of samples In which the contaminant was detected divided by the total number of
samples analyzed. In determining the frequency of detection, samples flagged with a data
qualifier of "I" (Invalid) were not included.
(b) Only pesticides and PCBs were analyzed for In these samples.
* • Selected as chemical of potential concern for the risk assessment.
-------
--"V-
INDICATES AN ESTIMATED
QUANTITY
- COMPOUND UNDETECTED
TI9N6 B8V SAMPLE
81203 WARZYN SAMPLE
9N9 E8E SAMPLE
. LOCATIONS OF SOIL BORINGS
ARE APPROXIMATE.
2. CONCENTRATIONS IN ug/kg.
3. DATA FROM SAMPLE NUMBERS
ENDING IN ???WERE NOT
'TED BY EPA.
4. TOTAL PESTICIDES ^
THE SUM OF ALL INDIVJ&UAL
p
S. R. 3 A
BEEtBEHCt
Sf LOUIS CORPS Of ENGINEERS FOR
USE PA CNVINONUENIAL MONITORING
SVSIEMS LABOHAIOHr, LAS VEG4S. NV.
.IIINF K IQHA
OF PESTICIDES
IN SUBSURFACE SOIL
K£M PEST LABORATORIES
PHASE I RI
-------
XMMMtfM *••>»•
__..« _!_*
SOIL BORINGS
INDICATES AN ESTIMATED
QUANTITY
COMPOUND UNDETECTED
. B8V SAMPLE
_ WARZYN SAMPLE
- E8E SAMPLE
TI9N6._
BI2OS__
T09N6—
I. LOCATIONS OF SOIL BORINGS
ARE APPROXIMATE.
2. CONCENTRATIONS IN ug/kg.
3. DATA FROM SAMPLE NUMBERS
ENDING IN ???WERE NOT
VALIDATED 8r EPA.
Sr LOUIS CORPS Of CNGINfERS FOR
USI PA f NVIRONMf NI»L MONIIOHING
H alQRr _l«S VtGAS. NV.
rSLfUS IJIHDH alQRr _l
CONCENTRATIONS OF
VOLATILES a SEMIVOLATILES
IN SUBSURFACE SOIL
KtU PES1 LABORATORIES
PHASE I Rl
-------
© COMPOSITE SURFACE SOIL
SAMPLE
® DISCRETE SURFACE SOIL
SAMPLE
088(096) SAMPLE NUMBER 0-6" (SAMPLE
NUMBER 6-12")
O SOIL BORING
an GRID NUMBER AND GRID LIMITS
. SAMPLE LOCATIONS ARE IDENTIFIED
BV TUC I **T »«••«•- —
..., _vwr.. IVMV.J nnc. IUCNII
BY THE LAST THREE DIGITS OF
THE EPA SAMPLE NUMBER. THE
„ ,- »~i«!f •.«. numac.n. I
PREFIX FOR ALL SAMPLES IS
TI9N6.
*7 "»
BEFEBEHCtJ
ST LOUIS CORPS OF ENGINECRS fOR
USEP* ENVIRONMCNI4L MONIfOHIHG
SYSTEMS LABORAIORr, LAS VEGAS, NV,
JUNE 6. 1988
FIGURE A-3
SOIL SAMPLE LOCATIONS
-------
LEGEND:
©
©
»«X8S»
*—«
COMPOSITE SEDIMENT SAMPLE
DISCRETE SEDIMENT SAMPLE
DRAINAGE CHANNEL I
DRAINAGE CHANNEL 2
*^^^^^ DRAINAGE CHANNEL 3
S DRAINAGE CHANNEL 4
DRAINAGE CHANNEL 5
END POINT OF SAMPLING
INTERVAL
SAMPLE NUMBER 0-6".
(SAMPLE NUMBER 6-12 )
I. SAMPLE LOCATIONS ARE IDENTIFIED
BV THE LAST THREE DIGITS OF
THE EPA SAMPLE NUMBER. THE
PREFIX FOR ALL SAMPLES IS
TI9N6.
3t=3=&
+<
SI. LOUIS CORPS OF ENGINEERS FOR
USEPA ENVIHONHINIAL MONITORING
SrSUMS tABOHAIONr, tAS VEGAS. NV.
JUNE 6. 1988
FIGURE A-4
SEDIMENT SAMPLE LOCATIONS
KEM-PEST LABORATORIES
PHASE I MI
-------
ATTACHMENT B
CHEMICALS OF CONCERN SUMMARY TABLE
POTENTIAL RISKS SUMMARY TABLE
-------
TABLE 8-1
Suimary of Selected Chemicals of Potential Concern
for the Kern-Pest Laboratories Site
SURFACE SOIL
CHEMICAL
ORGANIC;
AldHn (a)
Benzene (b)
Alpha-BHC (a)
Beta-BHC (a)
>elta-BHC (a)
ianma-BHC (a)
2-Butanone (b)
Urbon dlsulf Ide (b)
Ihlordane (a)
Ihlorobenzene (b)
:hlorofonn (b)
JOT (a)
3.3-Dichlorobenzidine
1.1-Dichloroethane (b
1.2-Olchloroethane (b
2.4-01ehlorophenol (c
Dieldrin (a
——_--—_
(Discrete
Samples)
X
X
X
X
(c)
X
_.» . , -----
(Composite
Samples)
X
X
X
X
X
X
SEDIMENTS
X
X
X
X
X
X
X
2.4-D1methylphenol (c)
SUBSURFACE
SOIL
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
BUILDING
SAMPLES
(all Media]
X
X
X
X
X
)1-n-butylphthalate (c) X
indosulfan sulfate (a)
Endosulfan I * II (a)
[ndrin (a)
[ndrin ketone (a)
Ethylbenzene (b)
Heptachlor (a)
X
X
X
X
X
Heptachlor epoxlde (a) X
X
X
X
X
X
X
X
X
X
X
X
texachlorobutadiene (c)
lethoxychlor (a)
2-Methylphenol (c)
X
X
X
N-N1trosod1phenyl«mine (c)
ncPAHs (c)
•entachlorophenol (c)
Toluene (b)
Toxaphene (a)
1,1,1-Trlchloroethane
2,4, 5-Trich loropheno 1
Kylene (total) (b)
INORGANICS
Jkrsenic
Lead
a) Pesticide
b Volatile Organic
&
X
X
X
f
•
X
X
X
X
X
X
X
X
X
X
X
X
X
x
X
X
X
X
X
X
X
X
X
c) Semi volatile Organic
-------
TABLE B-2
SUHHART OF POTENTIALLY SIGNIFICANT (a) RISXS ASSOCIATED JtTH THE KEM-PEST SITE
Land Use
Exposure Pathway/Area
Total Upperbound lifetm
Excess Cancer Risk
Honcareinogenic
Hazard Index
Average
Plausible
Naximn
Average
Plausible
Max inun
Current Land Use
Children Trespassing Onsite -
Direct Contact »ith Surface Soil
Grid S 4E-07
Grid 7 5E-06
Grid 8 7E-07
East Lagoon Area 2E-07
West Lagoon Area 4E-09
2E-06
3E-Q5
4E-06
3E-OS
2E-07
Children Trespassing Onsite -
Direct Contact with Sediment
Future Residential Land Use
5E-08
7E-OS
Residents - Direct Contact with
Surface Soils
Grids 1-4 iE-08
Grid S 4E-06
Grid 6 3E-08
Grid 7 5E-OS
Grid 8 8E-06
Grios 1A-4A IE-08
East Lagoon Area 2E-06
West Lagoon Area 5E-08
Bare Area (in Grid 8) 2E-07
Burnt Area (In Grid 8) 9E-05
Scrap Pile (in Grid 6} 3E-07
Residents - Direct Contact with
Sediment 5E-07
Residents • Inhalation of Volatile
Organics from Surface Soils 6E-OS
Residents - Inhalation of Volatile
Organics from Subsurface Soils IE-OS
Future Industrial Land Use
3E-07
3E-05
2E-07
4E-04
6E-OS
3E-07
4E-OA
2E-06
1E-06
2E-04
2E-06
1E-03
5E-07
9E-OS
2
3
Construction Workers - Direct Contact
with Subsurface Soils IE-07
Industrial Workers - Direct Contact
•itn Surface Soils
Grid S IE-07
Grid 7 2E-06
Grid 8 3E-07
East Lagoon Area 6E-08
West Lagoon Area 2E-09
Bare Area (in Grid 8) 6E-09
Burnt Area (In Grid 8) 3E-06
Scrap Pile (in Grid 6) IE -08
2E-06
3E-06
5E-OS
7E-06
SE-OS
2E-07
2E-07
2E-05
3E-Q7
Industrial Workers - Direct Contact
•ith Seoioents
2E-08
IE-04
-------
TABLE B-2 (cont.)
SuWURT OF POTENTIALLY SIGHIFICANT (a) RISKS ASSOCIATED WITH THE KEM-?ES7 SITE
Total Uppgrbound lifeline Noncarcinogenic
Excess Cancer Risk Hazard Inoex
Lend Use Plausible Plausible
Exposure Pathway/Area Average Maxiaut Average Naxiaun
Future Industrial Land Use (Cont.)
Industrial Workers - Innalation of
Volatile Chemicals from Surface 4E-08 4E-07 —
Soils
(a) Cancer Risks greater than 1E-07. hazard Indices greater than or equal to I.
— Heans less than one.
-------
ATTACHMENT C
EXCAVATION AREAS FIGURE
29
-------
2 DEPTH OF
EXCAVATION
DITCHES
SI LOUIS CORPS OF fHGINtf »S FOI!
UStPA ENVIHONMENIAL MONITONlNU
SrSItMS LABORAIORT, LAS VEGAS NV
JUNE 6, 1988
FlfillPF C-l
EXCAVATION AREAS AND DEPTH
KEM-PEST LABOHATOBIES
OPERABLE UNIT fS
-------
ATTACHMENT D
COST ESTIMATES SUMMARY TABLE
REMEDIATION GOALS FOR SURFACE SOIL SUMMARY TABLE
REMEDIATION GOALS FOR SUBSURFACE SOIL SUMMARY TABLE
30
-------
TABLE 0-1•
DETAILED COST ESTIMATE
OFFSITE DISPOSAL
ITEM
SOIL REMOVAL/SITE RESTORATION
Excavate Contaalnated Soil
Confirmation Stapling/Analysis
Ubor
Native Borrow, oapacted for fill
Topsoll
Grading
Revegetatlon
MATERIAL LOADING
Equipment Rental
Hourly Operation
Labor, 2 writers, 1 supervisor
TRANSPORTATION
DISPOSAL (Unit *t • 120 Ib/cu ft)
PROTECTIVE CLOTHING - Level D
DECONTAMINATION
Decontaai nation Area Construction
2 vehicle. 1 personnel
Decon Water Disposal
Off site Disposal
Transportation
QUANTITY
4.050
10
4
4.050
8*0
5.020
5.020
6
240
240
298
6.561
370
1
20.000
4
UNITS
CD YD
SAMPLE
WEEK
SQ YD
CU YD
SQ YD
SQ YD
WEEK
HOUR
HOUR
LOAD
TON
SET
LS
IS
LOAD
UNIT
COST
2.45
250.00
600.00
12.00
14.70
1.12
0.60
580.00
6.15
48.00
2.250
130.00
30.00
44000.00
2.10
750.00
COST
(S)
9.923
2.500
3.200
48,600
12,348
5,622
3.012
$85.000
3.480
1,476
11.520
$16,000
671.000
853.000
11.000
44,000
42.000
. 3,000
$89.000
-------
Table D-l (cont.)
DETAILED COST ESTIMATE
OFFSITE DISPOSAL
UNIT COST
ITEM QUANTITY UNITS COST ($)
SUBTOTAL - CONSTRUCTION. EQUIPMENT. TRANSPORTATION, $1.725.000
LABOR. DISPOSAL
BID CONTINGENCIES (15*) 259.000
SCOPE CONTINGENCIES (15%) 259,000
CONSTRUCTION TOTAL $2.243,000
PERMITTING AND LEGAL (5%) 112.000
CONSTRUCTION SERVICES (5*) 112.000
TOTAL IMPLEMENTATION COST J2.467.000
ENGINEERING DESIGN COSTS (5%) 112.000
TOTAL CAPITAL COST/PRESENT WORTH $2.579.000
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TABLE D-2
NUMERICAL VALUES FOR OTHER CRITERIA. STANDARDS. OR GUIDANCE
TO BE CONSIDERED FOR SELECTED COMPOUNDS DETECTED IN SURFACE SOIL AND SEDIMENT
MaxIMJM Concentrations Detected
Kern-Pest Laboratories site (mg/kg)
Compound
Aldrln
Dleldrln
Heptachlor epoxlde
ilphi-BHC
Heptachlor
Arsenic
beta-BHG
Chlordane
gaMM-BHC
Toxaphene
DOT
Surface
Soil.
1?
58
4.8
U
94
170
0.002
39
0.002
46
37
Sediment
68
34
2.8
0.024
240
--
0.019
39
0.021
U
32
Acceptable Contaminant
Concentrations In Soil
Haxlnum Plausible Case at Selected
Cancer Risk Levels (ing/kg)
1 x 10"6
0.2
0.2
0.3
0.4
0.6
I.I
1.6
2.2
2.0
2.5
8.2
1 x 10~5
1.6
1.7
3.1
4.4
6.;
11.3
15.6
21.5
20.0
25.5
82.3
1 x I0~*
16.5
17.5
30.8
44.4
62.2
113.0
156.0
215.0
200.0
254.0
824.0
HDOH Recommended
Safe Soil levels
Unrestricted Future Use
(•g/kg)
0.104
0.087
1.9
3.8
1.285
1.42
0.001
U - Undetected
a • Maximum plausible case for residential use of the site. Assumes 30 years of exposure,
?IO days/yr., l?0 wg soil Ingested per day (weighted average over exposure period).
contact with hands and forearm (1.760 en ); bloavallablllty for oral Ingest Ion Is 50%
for pesticides and 80* for arsenic; bloavalib!Illy for dermal contact Is ?\ for DDT. 2.7 %
for ganM-BHC. 2% for other pesticides, and no absorption of arsenic.
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TABLE D-3
ESTIMATED ACCEPTABLE CONTAMINANT CONCENTRATIONS FOR SUBSURFACE SOIL BASED
ON MAXIMUM CASE INHALATION EXPOSURES TO FUTURE RESIDENTS.
Chemical
Acceptable Contaminant Concentration
(mg/kg)
1x10
-4
1x10
-5
1x10
-6
Aldrin
Alpha-BBC
Beta-BHC
Chlordane
DDT
Dieldrin
Gamma-BHC
Heptachlor
Heptachlor Epoxide
4.6
39
1700
62
31,000
4.10
45
0.72
5.1
0.46
3.9
170
6.2
3,100
0.40
4.5
0.072
0.51
0.046
0.39
17
0.62
310
0.040
0.45
0.0072
0.051
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RECORD OF DECISION
SOIL AND SEDIMENT OPERABLE UNIT
RESPONSIVENESS SUMMARY DOCUMENT
KEM-PEST LABORATORIES SITE
CAPE GIRARDEAU COUNTY, MISSOURI
Prepared by:
U.S. ENVIRONMENTAL PROTECTION AGENCY
•
REGION VII
KANSAS CITY, KANSAS
SEPTEMBER 1989
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TABLE OF CONTENTS
1.0 INTRODUCTION
2.0 PROPOSED PLAN/SELECTED REMEDY
3.0 COMMUNITY PARTICIPATION
4.0 SUMMARY OF PUBLIC COMMENTS AND AGENCY RESPONSES
ATTACHMENT: SUMMARY OF PRP COMMENTS AND EPA RESPONSES
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1.0 INTRODUCTION
This Responsiveness Summary presents responses of the U.S.
Environmental Protection Agency (EPA) to public comments received
regarding remedial action for contaminated soil and sediment at
the Kern-Pest Laboratories site in Cape Girardeau County,
Missouri.
A brief outline of the Responsiveness Summary is provided
below:
Section 2.0 provides background information on the Proposed
Plan which presented the remedial alternatives developed for
the site and the preferred alternative for cleanup. This
section also briefly discusses the selected remedy.
Section 3.0 describes community participation in the selection
of the final remedy for contaminated soils and sediment.
Section 4.0 includes a summary of comments received from all
interested parties, including potentially responsible parties
(PRPs). A response by EPA to each comment summary is
provided.
Attachment A provides a summary of comments submitted by the
PRPs and the responses provided by the Agency. The summary of
comments and responses are being provided as an attachment due
to the length and detail of the comments.
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2.0 PROPOSED PLAN/SELECTED REMEDY
PROPOSED PLAN
On August 18, 1989, EPA issued the Proposed Plan for the
Kern-Pest Laboratories site. The plan presented excavation and
disposal in an offsite hazardous waste landfill as the preferred
alternative for the cleanup of contaminated soil and sediment at
the site. The plan also provided background information on the
nature of the problem at the site and described other remedial
alternatives which were considered.
In addition to describing remedial options for cleanup, the
plan also outlined how the public could participate in selection
of the final remedy.
SELECTED REMEDY
Based on an evaluation of the relative performance of each
alternative with respect to nine evaluation criteria, and
consideration of comments received from the community, including
the PRPs, EPA and the State of Missouri selected excavation and
disposal in an offsite hazardous waste landfill as the most
appropriate remedy for contaminated soil and sediment at the
site.
A risk assessment was conducted to evaluate the potential
effects to human health for current and future land use
scenarios. The results of the risk assessment indicated that
concentrations of contaminants in soil and sediment at several
locations on and adjacent to the site result in excess lifetime
cancer risks as high as 7 x 10~5 current land use and 1 x 10~3
for future residential land use.
Protective contaminant soil concentrations were calculated
using risk assessment techniques for chemicals of concern at the
site. Based on the protective soil concentrations, approximately
4,050 cubic yards of contaminated soil and sediment would be
excavated and transported to a RCRA-approved commercial hazardous
waste landfill for disposal. The RCRA facility would provide
secure, long-term management through specially designed covers,
multi-liner systems, leachate detection and collection components
and monitoring.
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3.0 COMMUNITY PARTICIPATION
Prior to the initiation of the remedial investigation (RI),
a community relations plan was developed based on interviews
conducted by the community relations staff with residents and
local officials. The plan documented the issues of concern to
the community which included the need for information on future
site activities and potential threats to human health.
At the start of RI field activities, the EPA remedial
project manager met with the Cape Girardeau County Commission and
other local county and city officials to discuss the field work.
The project manager also conducted informal interviews at nearby
residences to inform them of site activities and to answer
questions.
Fact sheets about the project were mailed to residents,
local officials and the media. During field work, nearby
residents and local officials were provided updates.
In August 1989, the RI and Operable Unit Feasibility (OUFS)
reports and Proposed Plan were made available to the public in
the administrative record located at the Cape Girardeau Public
Library and at EPA Region VII offices in Kansas City. A public
notice was issued announcing the availability of documents, the
start of the public comment period and the date of the public
meeting. The public notice was published in the Southeast
Missourian on August 18, 1989, and in the Cape Girardeau News
Guardian on August 23, 1989.
Fact sheets were also mailed to residents, local officials
and the media announcing the availability of documents, the
public comment period and the public meeting.
The public comment period was held from August 18, 1989,
through September 18, 1989. A public meeting was held in Cape
Girardeau on September 5, 1989. At the meeting, representatives
from EPA, the Agency for Toxic Substances and Disease Registry
(ATSDR) and the Missouri Department of Natural Resources (MDNR)
provided information on the site and discussed the remedial
alternatives under consideration. During an extension of the
comment period, the EPA community relations staff conducted
interviews with concerned citizens.
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4.0 SUMMARY OF PUBLIC COMMENTS AND AGENCY RESPONSES
This section provides a summary of comments received from
the community, including the PRPs, and'presents the Agency's
response. Statements made at the public meeting are summarized
first with EPA's responses to the statements. Written comments
received by EPA and the Agency's responses are provided next.
COMMENTS RECEIVED AT PUBLIC MEETING
A. A commentor asked why information regarding the February and
March sampling had not been provided by the Agency. The
commentor noted that when her well was sampled in 1987, she
received information in the mail. The commentor explained
that in February and March a field crew was on her farm,
located immediately north of the site.
EPA RESPONSE: The remedial investigation field activities
conducted by EPA in February and March of 1989 did not
include any sampling or other field activities on the
commentor's property, located north of the Kern-Pest site.
Field activities were conducted by EPA on the northern
portion of the Kern-Pest site; no field activities were
conducted north of the site property boundary. Information
obtained during the field activities, including sample
results, are provided in the Remedial Investigation Report,
available for review at the Cape Girardeau Public Library.
B. A commentor asked where public comments should be submitted.
EPA RESPONSE: The commentor was provided the name and
mailing address of the EPA contact. The commentor was also
informed of the toll free number on the back of the Fact
Sheet.
C. The Cape Girardeau Presiding County Commissioner stated that
that a week was not enough time for residents to comment.
The Commissioner emphasized that if the residents have
comments to make, the Agency should listen.
EPA RESPONSE: On August 18, 1989, the Agency issued a public
notice in the Southeast Missourian announcing the start of
a 21-day public comment period. The public notice was again
published on August 23, 1989, in the Cape Girardeau News
Guardian. The public notices also provided information
regarding the public meeting on September 5, and the
availability of EPA reports at the local library.
Prior to publication of the two public notices, the County
Commissioner's office and other county and city offices were
notified of the public comment period.
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Fact sheets were also sent to residents, local officials and
the media announcing the public comment period, the public
meeting and the availability of documents at the library.
Nevertheless, in response to the County Commissioner's
concern regarding the opportunity for residents to submit
comments, the EPA extended the public comment period from
September 8 to September 18. In addition, EPA community
relations staff met with area residents in Cape Girardeau to
listen to and receive oral or written comments.
WRITTEN COMMENTS RECEIVED DURING THE PUBLIC COMMENT PERIOD
A. A local resident expressed support for the preferred
alternative. The commentor also expressed concern regarding
long-term health effects to current and former area
residents. The commentor noted that several families
obtained water from a shallow well at a house which had
been located directly across from the site; the house was
demolished several years ago.
EPA RESPONSE: Remedial action at the site is being
implemented through a series of operable units, or discrete
response actions. This first operable unit addressed the
threats posed by contaminated soils and sediments. Operable
units addressing ground water and the formulation building
will be initiated soon. A risk assessment will be conducted
to evaluate the potential threats posed by ground water. EPA
will provide the results of this evaluation when completed.
The Agency for Toxic Substances and Disease Registry (ATSDR)
is also conducting a Health Assessment to assess impacts on
public health. This Health Assessment will include a
determination regarding the need for follow-up health effects
studies of exposed populations. ATSDR will be asked to
contact the commentor regarding the Health Assessment
conclusions.
B. A former resident expressed support for the preferred
alternative. The 'commentor also expressed concern regarding
the lack of health assessments for persons who have lived
in the vicinity of the site. The commentor noted that on
numerous occasions children were seen playing at the lagoon
and, on at least one occasion, a child was seen in the
lagoon.
EPA RESPONSE: As discussed in the previous response, a risk
assessment addressing ground water and a Health Assessment
will be completed for the site. ATSDR will be asked to
contact the commentor regarding the Health Assessment
conclusions.
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An extensive comment package was submitted by the potentially
responsible parties. This comment package identified several
areas of concern. Due to the length and detail of the PRPs'
comments and the responses provided by the Agency, the
summary of comments and responses are provided as an
attachment to this document. The entire (PRP) comment
package and the Agency's response to each comment are
provided in a separate document which is available for review
in the Administrative Record located at the Cape Girardeau
Public Library.
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RESPONSIVENESS SUMMARY ATTACHMENT
SUMMARY OF PRP COMMENTS AND EPA RESPONSES
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PRP COMMENT LETTER DATED 9/12/89
A. The Excavation and Off-Site Disposal of Soils and
Sediments Is Not Cost-Effective.
EPA must select excavation/capping remedy because the
OUFS indicates it is expected to achieve the health-based
goals at a cost of $1.1 million which is significantly
less expensive.
EPA RESPONSE TO A:
The EPA has developed nine evaluation criteria to address
CERCLA statutory requirements and technical, cost, and
institutional considerations. The evaluation criteria serve as
the basis for conducting the detailed analyses of alternatives
during the OUFS and for subsequently selecting an appropriate
remedy.
Overall protection of human health and the environment and
compliance with applicable or relevant and appropriate
requirements (ARARs) are threshold criteria that must be
satisfied in order for an alternative to be eligible for
selection. Long-term effectiveness and permanence, reduction of
toxicity, mobility, or volume, short-term effectiveness,
implementability, and cost are the primary balancing factors used
to evaluate the major trade-offs between the alternatives.
As stated in the OUFS, all the alternatives, with the
exception of no action, would attain health-based goals.
However, based upon an evaluation of the relative performance of
each alternative with respect to the primary balancing criteria,
and consideration of comments received during the public comment
period, both EPA and the State of Missouri determined that
excavation and offsite landfill was the most appropriate remedy
for contaminated soil and sediment at the Kern-Pest site.
The selected remedy provides a higher degree of long-term
effectiveness and permanence than the capping alternative. The
selected remedy would-not require long-term management or
institutional controls at the site. .A RCRA-permitted hazardous
waste facility would provide more secure, long-term containment
through a double liner system, leachate detection and collection
system and monitoring programs. In comparison, capping provides
a lesser degree of long-term effectiveness and permanence. This
option would require long-term maintenance and monitoring at the
site. Land use and ground water use restrictions for the life of
the alternative would be required. Moreover, capping does not
address potential threats posed by contaminated subsurface soils
to ground water; the potential for future release and exposure
would have to be considered.
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The selected remedy reduces both the volume and mobility of
contaminated material located at the site. The contaminated soil
and sediment removed from the site would be effectively contained
at the offsite facility meeting RCRA design and operating
requirements including double liner, leachate detection and
collection system, and monitoring. Capping, on the other hand,
does not reduce the volume of contaminated material on the site.
The mobility of contaminants in the subsurface soils would remain
a concern.
The selected remedy is more effective than the capping
alternative in the short-term, requiring 7-9 months to implement
as compared to a year for capping.
The selected remedy has fewer technical difficulties
associated with implementation. In addition, the selected remedy
would not present any significant problems if future remedial
actions were required. The capping alternative, in comparison,
would be more difficult to implement. Construction of the cap
around the building would be technically complex. The cap would
also make it more difficult to implement additional remedial
actions, if required.
The selected remedy is cost-effective when the overall
relationship between cost and effectiveness is compared to the
cost/effectiveness relationship of capping. As described above,
the selected alternative provides a higher degree of long-term
effectiveness and permanence, short-term effectiveness and
technical feasibility, and provides for a reduction of mobility
and volume.
The selected remedy was supported by the State of Missouri.
The State indicated that capping was the least preferred
alternative due to concerns regarding the potential impact of
contaminated subsurface soil on the ground water.
During the public comment period, the Agency received two
written comments from area residents. Both comments expressed
support for the offsite hazardous landfill alternative.
•
Based on an evaluation of the relative performance of each
alternative with respect to the evaluation criteria, and
consideration of comments received during the public comment
period from the State of Missouri and the community, excavation
and offsite landfill is the most appropriate remedy for
contaminated soil and sediment at the Kern-Pest site.
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B. The Remedy Proposed by EPA is Unreasonable, Arbitrary
and Capricious Because it Does Not Consider Relevant Data.
1. OUFS overestimates alleged health and environmental
effects of pesticides because it assumes future
residential use.
2. OUFS unreasonably assumes that the soils and sediments
are a RCRA hazardous waste.
3. OUFS does not consider background levels of pesticides
in agricultural and residential areas, pesticide levels
in soils when applied according to accepted practices, or
the rate at which the pesticides naturally degrade.
EPA RESPONSE TO B-l:
The Public Health Evaluation addresses the potential impacts
on human health associated with the site under the no-action
alternative. Evaluation of the no-action alternative is required
by the National Contingency Plan. The no-action alternative
assumes that no remedial actions and no land use restrictions
would be applied to the site.
An exposure assessment, a component of the Public Health
Evaluation, was conducted to identify the potential pathways by
which human populations could be exposed to contaminants. In
identifying potential pathways of exposure, both current and
future land use was considered. Future residential use was
evaluated in order to provide an upper bound on exposure and risk
estimates for soils and sediments from future use of the site.
Residential use of the site may be less likely to occur than
industrial use given the area is zoned for industrial use and
other institutional controls restricting land use may be
available. However, future residential use represents a
reasonable maximum exposure scenario.
A review of past_and present land use in the immediate
vicinity indicated that residential use is a primary use of land
in the area. Over a dozen residences are currently located
within a 1000 foot radius of the site. The closest residence is
within 500 feet of the site. With respect to past use of the
land, a home was located less than 300 feet from the site
entrance during the period of plant operations.
In addition, there are legitimate concerns regarding
institutional controls. Zoning changes could conceivably occur.
Implementation, enforceability, reliability, and long-term
effectiveness are additional issues relating to the use of
institutional controls.
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EPA RESPONSE TO B-2:
EPA has determined that the wastes generated at the Kern-Pest
site are RCRA hazardous wastes. As stated in the PRPsV comment,
aldrin, dieldrin, heptachlor, chlordane, DDT, lindane and
toxaphene are listed under Section 261.33(f), commercial chemical
products. Information provided by the PRPs to EPA in their
Notification of Hazardous Waste Site pursuant to Section 103 of
CERCLA and their response to EPA's Information Request under
Section 104(e) of CERCLA stated that spills of commercial
chemical products were washed down the drain of the formulation
building and disposed of in the lagoon. Accordingly, there was
disposal of a RCRA hazardous waste in the lagoon. Furthermore,
any wastes generated from the treatment, storage or disposal of a
hazardous waste is a hazardous waste. None of the exemptions or
exclusions set forth in 40 CFR 261.3 or 261.4 were found to be
applicable to the wastes generated at the Kern-Pest site.
EPA RESPONSE TO B-3:
The surface application of chlordane and heptachlor was used
extensively in agriculture and around the home for controlling a
variety of insects until banned by the EPA in the mid-1970's,
based on evidence that these substances caused tumors in
laboratory animals and were persistent in the environment. Due
to the presence of elevated levels of chlordane in air samples
inside the home, and continued concern with health effects, the
Agency recently banned the further sale, distribution and
commercial application of the pesticides chlordane and heptachlor
for termite control.
The pesticides at the Kern-Pest site are very persistent in
soils and are expected to degrade very slowly, thus the overall
risks are not expected to be significantly affected because of
degradation. Degradation rates can widely vary from one location
to another and are affected by a wide range of variables such as
soil type, soil temperature, soil moisture, precipitation, soil
microorganisms and percent sunshine. For example, Table 1 in
Exhibit 6 of the comments indicates that houses #5 and #6 (both
located on clay soils in the Piedmont region of North Carolina)
presumably each had 378 liters of chlordane (Termide) applied in
1979 and approximately four years later the residues in soil (at
0-10 cm) were very different at the two sites, 1,890 ppm for #5
and 852 ppm for #6. Thus, there is much uncertainty associated
with using degradation rates from areas with different soil
types, etc., than the Kern-Pest site.
We agree that the OSHA Standards should have been identified
as ARARs for inhalation exposures to workers and that the
estimated air concentrations are less than the OSHA standards.
However, the proposed remediation of surface soils is based on
estimated risks from direct contact exposures and is not
-------
dependent on the estimated risks from inhalation exposures since
these risks are lower. Thus, the use of the OSHA values as ARARs
would not affect the results of the feasibility study.
The interim guideline levels recommended by the National
Academy of Sciences are not enforceable criteria for the site and
are not available for all the chemicals of concern at the site,
thus cleanup levels were not derived based on these values, but
were derived using quantitative risk assessment methods.
C. The Remedy Proposed by EPA is Unreasonable, Arbitrary and
Capricious Because it is Based Upon Inadequate Data.
1. The method used to derive subsurface soil cleanup levels
has not been demonstrated to be applicable to pesticides.
2. The RI contains data that have not been adequately
quality assured.
3. The use of unfiltered water samples provides unreliable
data.
4. The remedies analyzed in the OUFS contain inadequate
design and cost assumptions.
5. The RI contains unsubstantiated speculation to the source
of materials at the site.
EPA RESPONSE TO C-l:
The exposure parameters used for the maximum exposure
scenario are not unreasonable for some portions of the
population, such as persons who work at home. Although some of
these people may spend several hours per week away from home, or
even several days per year, the reduction in lifetime dose would
be quite small. The exposure period of 30 years represents the
upper-bound time (90th percentile) at one residence as cited in
the "Exposure Factors Handbook", EPA 1988. The "Exposure Factors
Handbook" is widely used as a source for exposure parameters for
risk assessment.
The Hwang volatilization model used in the Kern-Pest Public
Health Evaluation is appropriate for use with chemicals that have
limited aqueous solubility and a high soil affinity such as the
pesticides found at this site. Therefore, the use of this model
to estimate pesticide volatilization is appropriate. Dr. Hwang,
author of the model, is a recognized expert in the field of
volatilization. He has developed many models for volatilization
that have been recommended for use by the EPA. The Hwang model
used for this risk assessment was presented in a document that
-------
was subjected to the EPA's peer review policies and was approved
for publication.
EPA RESPONSE TO C-2:
As noted in the response to the comment on Page 4-1, last
paragraph (Attachment B), "it is not standard practice to include
data validation memoranda in the RI report. The Guidance for
Conducting Remedial Investigations and Feasibility Studies Under
CERCLA (EPA/540/G-89/004, page 3-31) lists "Analytical Data and
QA/QC Evaluation Results" as an appropriate appendix for the RI
report. The analytical data and QA/QC evaluation results for the
Phase I RI are included in Appendix G, Volume III, of the Phase I
RI report. All data qualified as a result of the data validation
procedures are identified by flags in the tables and the flags
are defined at the beginning of the appendix. The data quality
discussions at the beginning of each of the subsections in
Section 4.0 of the Phase I RI report provide additional
explanation of the results of the data validation. The data
validation memoranda are a part of the public record for the
Kern-Pest Laboratories site and are available upon request from
EPA Region VII."
As stated on page 4-3 of the Phase I RI report with regard
to the subsurface soil samples (and again on page 4-40 with
regard to the sediment samples), "overall correlation between the
original samples, splits and duplicates for the subsurface soil
is not very good. However, these discrepancies are
characteristic of analytical results for soil samples and are
generally attributed to media effects. Because soil is not
homogeneous and because many contaminants adsorb strongly to soil
particles, contaminants are not uniformly distributed in this
medium." Therefore, such variability in analytical results from
soil samples is to be expected and such results are considered
acceptable.
As discussed on pages 4-23 through 4-25 of the Phase I RI
report, the decision to collect a second round of ground water
samples for pesticides was based primarily on the fact that:
1) The technical holding time for the samples was exceeded
by 20 days; and
2) Since the matrix spike/matrix spike duplicate analyses
were unsuccessful and the surrogate was diluted out in
five of the eight samples, there was not an adequate
measure of precision and accuracy on these samples.
The variability between the unfiltered duplicate and the
original unfiltered sample for monitoring well MW-2 was discussed
as possibly providing evidence of the impact of the exceeded
holding times, as indicated by this quote from page 4-24 of the
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Phase I RI: "The correlation between the pesticide analytical
results for the unfiltered duplicate sample from well MW-2 and
those for the original unfiltered sample from this well (which
was analyzed with another group of samples for which the holding
time was not exceeded) is very poor. This could be the result of
matrix effects since a significant amount of suspended sediment
was present in the water from this well. However, the very low
concentrations identified in the duplicate could also be a result
of the exceeded holding time. If it is possible that the
pesticides have degraded over time, this calls into question the
analytical results from the offsite wells MW-7B and MW-6A, where
no pesticides were detected. Therefore, in order to ensure that
valid data are used to evaluate pesticide presence and possible
migration from the site, a second round of unfiltered ground
water samples will be collected and analyzed for pesticides and
PCBs." However, the variability between the results of the
analyses of these two samples was not the primary justification
for the decision to collect a second round of samples.
It is standard practice to use estimated (J-flagged) data
for evaluating the nature and extent of the contamination and in
conducting the risk assessment. This practice is based upon the
fact that data are generally flagged as estimated values as a
result of minor deviations from laboratory protocol. Minor
deviations include such things as serial dilution, matrix spike
recovery or duplicate relative percent difference being outside
control limits. Any major deviation from laboratory protocol
would result in data being invalidated. The minor deviations
identified above result in analytical concentrations that are
generally within a small range of the true values. As discussed
in the responses to Attachment B, comments page 4-34 - Section
4.3.2, Soil Samples from 0 to 6 inches and page 4-44 - first
paragraph, the conclusions regarding the nature and extent of the
contamination can generally be justified without the use of J-
flagged data.
The quality of the Kern-Pest data from a laboratory
perspective was very high. The data for this site which have
been reported with "J" qualifiers as estimated data were
qualified either because 1) the reported values were below the
laboratory's contract'required quantitation limit (CRQL) or 2)
quality control requirements were not met for initial or
continuing calibration verification. With regard to the second
reason for qualification, no gross deviations in instrument
sensitivity or accuracy of calibration were observed. Thus,
these data points are acceptable in a semiquantitative sense.
A high degree of variation was noted for field duplicate
results. Laboratory duplicate precision was excellent. The
laboratories analyzed matrix spike and matrix spike duplicate
samples for each matrix and analysis type. The results for the
spiking compounds for some sample sets could not be evaluated
-------
since the spike amount was low relative to original sample
concentration. However, for analytes detected in the samples
which were not spiking compounds, duplicate precision was
excellent. This indicates that the variance in field duplicate
results was most likely due to nonhomogeneous sample matrix.
Qualification of results is performed using guidelines which
try to cover every possible data usage. Depending on the nature
of the QA/QC outlier(s) and number of outliers affecting any
given data point, a range of quantitative variability may be
represented by a "J" qualifier. The represented variability may
or may not be significant relative t.o other considerations
related to data usage. In this case, it appears that the degree
of variance referred to by the "J" qualifier for sample
concentrations greater than the CRQL is significantly less than
the variance of contaminants in the soil matrix. The use of
these concentrations to represent ranges of contamination as in
fig.4-6A through 4-6B is an acceptable use of estimated data.
Data collected for the Kem-Pest site were subject to
complete QA/QC: sample collection was documented on field
sheets; field QC samples such as field duplicates and equipment
rinsates were collected; samples were processed using chain-of-
custody documents; approved laboratory calibration and analytical
procedures were defined and followed; internal laboratory quality
control was satisfactorily performed; and data were reviewed,
validated and reported in Region VII EPA format. In addition,
analyses were largely conducted by laboratories participating in
the contract laboratory program (CLP). CLP laboratories analyze
performance evaluation EPA audits quarterly and annually. They
perform internal QA/QC in accordance with the contract specified
revision of the "Statement of Work for Organics Analysis -
Multi-Media, Multi-Concentration."
The comments of PRPs state a concern that the "cumulative
effect (of inadequate QA/QC) is substantial." This concern is
unfounded.
EPA RESPONSE TO C-3:
As discussed in the responses to the specific comments
included in Attachment C, it is standard practice to analyze
unfiltered ground water and to use such results in evaluating the
nature and extent of the contamination and in conducting the risk
assessment. Since water from rural wells is often unfiltered,
analytical results from unfiltered samples provide a more
realistic basis for risk assessment purposes than do filtered
samples. The Agency for Toxic Substances and Disease Registry
requests the results of analyses of unfiltered samples when
conducting health assessments.
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EPA RESPONSE TO C-4:
The general response to comments in Attachment D states:
"As stated on pages 4-5 and 4-6 of the Soil and Sediment Operable
Unit Feasibility Study (OUFS), the OUFS cost estimates are
order-of-magnitude level estimates, which are defined by the
American Association of Cost Engineers as an approximate estimate
made without detailed engineering data. Examples include an
estimate from cost capacity curves and estimates using scale-up
or scale-down factors and/or approximate ratio estimates. It is
normally expected that an estimate of this type would be accurate
to +50 percent and -30 percent for given unit quantities. The
actual cost of the project would depend on the final scope of the
remedial action, the schedule of implementation, actual labor and
material costs at the time of implementation, competitive market
conditions and other variable factors that may impact the project
costs.
This approach to feasibility study costs is consistent with
the RI/FS guidance which states on page 6-12 that study estimate
costs made during the FS are expected to provide an accuracy of
+50 percent to -30 percent.
In addition, the primary purposes of cost estimates in a
feasibility study are 1) to provide a basis for comparison
between alternatives and to determine a relative ranking of
alternatives on the basis of costs and 2) to provide a basis for
EPA to allocate funding for remedial action.
Based on these purposes and the requirements for feasibility
study estimates stated on the previous page, the comments on the
feasibility study costs in Section D are generally inappropriate.
Many of the comments, including the comments associated with
borrow soil, decontamination, protective clothing, monitoring and
onsite transportation apply to several or all of the alternatives
so they have no impact on the relative ranking of the
alternatives. The comments also imply that the cost estimates
are too conservative. However, if the cost estimates are to
serve as a basis for allocating funding for remedial action, a
conservative estimate is required in order to ensure that
adequate funds are made available. For instance, since the OUFS
is based on the assumption that EPA would hire a contractor to
perform the required services, it could not be assumed that fill,
topsoil, etc., would be available from the site under those
circumstances.
A few errors in the costs were identified. These errors
have been corrected and the new costs noted in the response to
the comments in Attachment D; none of the changes altered the
relative ranking of the alternatives.
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EPA RESPONSE TO C-5:
As stated in the response to all comments in Attachment E
relating to Section 4.0: "The objectives of the Phase I RI
included evaluating 1) the sources of contamination and 2) the
specific contaminants of concern. In evaluating the nature and
extent of the contamination, certain anomalies were noted in
results of analyses of the environmental samples. These
anomalies included 1) identification of contaminants not
consistent with existing information relating to site activities
or with the results of previous investigations and 2)
identification of contaminants in areas where contamination was
not anticipated, based on existing information relating to site
activities and the results of previous investigations. These
anomalies are of concern because they may indicate the existence
of unidentified sources of pathways requiring further
investigation. The 'speculation1 referenced in the comments in
Attachment E represents an attempt to find a logical explanation
for these anomalies and to evaluate whether or not they require
further investigation. In all cases, the wording of the
discussions in the RI report make it clear that the analyses are
not statements of fact."
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