United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R04-89/052
September 1989
feEPA
Superfund
Record of Decision
Smith's Farm, KY
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* 50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R04-89/052
X Recipient1 AccmaJon No.
4. T1U* and Subtitle
SUPERFUND RECORD OF DECISION
Smith's Farm, KY
First Remedial Action
5. Report Oat*
09/29/89
7. Authors)
8. Performing Organization Rep*. No.
9. Performing Organization Kam* and Address
10. ProfecVTaak/Work Unit No.
11. Contract(C) or GranqG) No.
(C)
(0)
12. Sponsoring Organization Nam* and Addrew
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
IX Typ* of Report A Period Covered
800/000
14.
15. Supplementary Note*
16. Abatract (Limit: 200 word*)
The Smith's Farm site is a 560-acre property in a rural area of Bullitt County,
Kentucky. The site is bordered on the north, east, and west by forested hills and on the
south by a residential area. Within the 560-acre property there is a 37.5-acre landfill
that, until recently, was permitted by the State for the disposal of solid waste. The
owner of this landfill was cited at various times by the State for permit violations.
^he property also includes an 80-acre area upgradient of the permitted landfill on a
Bile-long ridge between two intermittent creeks where the unpermitted disposal of drums
Containing hazardous waste occurred over a 20-year period. EPA investigations from 1979
to 1984 resulted in the removal of 6,000 surface drums containing hazardous waste
including PCB-contaminated waste. This remedy addresses contaminated onsite soil, \
sediment, and drums within" the 80-acre area. A second operable unit will address the
remaining potential threats associated with the landfill, deep ground water aquifers,, and
other suspected areas of drum disposal. The primary contaminants of concern affecting
the soil and sediment are organics including PCBs and PAHs, and metals including lead.
The selected remedial action .for this site includes excavation and onsite incineration
of approximately 26,200 cubic yards of contaminated soil, surface drums, buried drums,
and fill material from Area B (as defined in the RI/FS), and (Continued on next page)
KY
17. Document Analysis a. Descriptors
Record of Decision - Smith's Farm,
Final Remedial Action - Final
Contaminated Media: soil, sediment
Key Contaminants: organics (PCBs, PAHs), metals (lead)
b. kfentifiera/Open-Ended Term*
. c. COS AT) Held/Group
J. Availability Statement
19. Security Class (Thl* Report)
None
20. Security daa* (Thla Page)
None
21. No. of Pages
99
22. Price
(See ANSI-Z39.18)
Set Instruction* on /fevers*
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(Formerly NTIS-35)
Department of Commerce
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17. Document Analysis, (a). Descriptors. Select from the Thesaurus of Engineering and Scientific Terms the proper authorized terms
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ft GPO: I983 0 - 381-526(3393) OPTIONAL FORM 272 BACK
(4-77)
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EPA/ROD/R04-89/052
Smith's Farm, KY _^.
First Remedial Action - Final
16. Abstract (Continued)
approximately 5,200 cubic'yards of contaminated onsite sediment from the valley streams;
solidification/fixation of approximately 50 percent of the treated material followed by
placement of all treated:or solidified material in Area B; incineration of a small
volume of hot spot material in Area A and- consolidation of waste and construction of a
RCRA cap over Area A; construction of a leachate-collection system to collect leachate
from Area A; access restrictions (fencing) around contaminated areas; ground water
monitoring for up to 27 years; maintenance of the RCRA cap and the leachate collection
system; and leachate removal and disposal for up to 30 years. The estimated present
worth cost for this remedy is $26,900,000, which includes O&M costs of $1,330,000.
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RECORD OF DECISION
Remedial Alternative Selection
SITE NAME AND LOCATION
Smith's Farm Site (First Operable Unit)
Brooks/ Kentucky
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for the
Smith's Farm site (First Operable Unit), Brooks, Kentucky, developed
in accordance with CERCLA, as amended by SARA, and to the extent
practicable, the National Contingency Plan. The following documents
form the basis for selection of the remedial action:
- Remedial Investigation Report, Smith's Farm Site
- Feasibility Study Report, Smith's Farm Site
Summary of Remedial Alternative Selection
Responsivenesss Summary
- Staff Recommendations and Reviews \
DESCRIPTION OF THE REMEDY
The function of this remedy is to reduce the risks associated with
exposure to contaminated, on-site surface soils, to contaminated,
on-site stream sediments, and to contaminated, on-site surface and
ground waters.
The major components of the selected remedy include:
Site Area B and Stream Sediments . .
-- Excavation to bedrock of contaminated soil and waste
materials from site Area B and excavation of
contaminated stream sediments
- incineration of the contaminated materials from Area B
and the contaminated stream sediments
- Solidification/fixation of the treatment residuals
Site Area A
Recontouring Area A to achieve a maximum 18 percent
slope, combined with the consolidation of wastes from
peripheral areas and retaining wall construction for
slope stabilization
"RCRA" Cap over Area A with the incineration
of a small percentage of contaminated'Area A soil
and/or waste, as necessary and cost effective
Construction of a leachate-collection system to
collect contaminated water discharging from
Area A
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RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
SMITH'S FARM SITE- FIRST OPERABLE UNIT
BROOKS, KENTUCKY
PREPARED BY:
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GEORGIA
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General
Access restriction (fencing) around contaminated areas
Annual ground-water monitoring for up to twenty seven
years
Maintenance of the RCRA cap and the leachate collection
system for up to thirty years
Leachate removal and disposal for up to thirty years
DECLARATION
The selected remedy is protective of human health and the
environment, attains Federal and State requirements that are
applicable or relevant and appropriate to the remedial action, and is
cost-effective. This remedy satisfies the statutory preference for
remedies that employ treatment that reduces toxicity, mobility, or
volume as a principal element and utilizes permanent solutions and
alternative treatment technologies to the maximum extent
practicable. However, because of the balancing of cost factors with
the protection of human health and the environment, hazardous
substances may remain in the soil in excess of health-based cleanup
levels.
Because this remedy may result in hazardous substances remaining on
site above health-based levels, a review will be conducted within
five years after the commencement of remedial action to ensure that
the remedy continues to.proviae adequate protection of human health
and the environment.
Date I Greer C. Tidwell
Regional Administrator
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SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
SMITH'S FARM SITE- FIRST OPERABLE UNIT
BROOKS, KENTUCKY
PREPARED BYl
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GEORGIA
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TABLE OF CONTENTS
1.0 INTRODUCTION 1
1.1 Site Location and Description 1
1.2 Site History 3
2.0 ENFORCEMENT ANALYSIS 4
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION 7
4.0 SCOPE AND ROLE OF OPERABLE UNIT » 7
5.0 CURRENT SITE STATUS > 8
5.1 Environmental Setting 8
5.1.1 Bedrock/Geology 8
5.1.2 Soils 9
5.1.3 Hydrogeology - 9
5.1.4 Surface Water and Topography 10
5.2 Study Area Contamination 10
5.2.1 Surface Soil Contamination ... ---10
5.2.2 Subsurface Soil Contamination . 12
5.2.2.1 Area C 12
5.2.2.2 Area B 12
5.2.2.3 Area A . ^-16
5.2.2.4 Other areas 16
5.2.2.5 Summary of subsurface soil contamination 17
5.2.3 Ground-Water Contamination - 17
5.2.3.1 Sampling results and data analysis --17
5.2.3.2 Summary of ground-water data 21
5.2.4 Surface Water Contamination 25
5.2.4.1 Organic contamination 25
5.2.4.2 Inorganic contamination - 27
5.2.4.3 Surface water contamination summary 27
5.2.5 Stream Sediment Contamination 27
5.2.5.1 Organic contamination 27
5.2.5.2 Inorganic contamination -i- 31
5.2.6 Summary of the Study Area Contamination 31
6.0 SUMMARY OF SITE RISKS -38
6.1 Introduction- 38
6.2 Assumptions and Methods of Analysis 40
6.2.1 Exposure 4 o
: 6.2.2 Chemicals 42
6.2.3 Risks 42
6.3 Contaminants Considered in the Risk Analysis -44
6.3.1 Surf ace Soils ' 44
6.3.2 Subsurface Soils -« r 44
6.3.3 Surface Water "-< 45
6.3.4 Stream Sediments ---; 45
6.3.5 Ground Water ------ 46
6.4 Toxicity Assessment Information ;-46
6.5 Risk Characterization 48
6.5.1 Current-Use Scenario Risks - 48
6.5.1.1 Risks to Trespassers from Surface Soils 48
6.5.1.2 Risks to Trespassers from Sediments 49
6.5.1.3 Risks to Trespassers from Contact with
Surface Water -.* 49
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Table of Contents, continued
6.5.1.4 Risks to Off-Site Residents from Contact
with Surface Water and Stream Sediments 49
6.5.1.5 Risks from Inhalation of Dust Generated by
Dirt Bikes 49
6.5.1.6 Risks to Trespassers from Inhalation of
Volatile Organics Released from Surface
Water 49
6.5.1.7 Risks from the Use of Residential Wells 51
6.5.2 Future-Use Scenario Risks 51
6.5.2.1 Risks from Direct Contact with Soils by
On-Site Residents 51
6.5.2.2 Risks from Use of On-Site Ground Water --51
6.5.2.3 Risks to Off-Site Residents 53
6.5.2.4 Other Future-Use Risks 53
6.5.3 Qualitative Risks 53
6.5.4 Summary of Human Health Risks 53
6.6 Environmental Risks 53
6.6.1 Receptors ........ ... .54
6.6.2 Exposure Rates ......--54
6.6.3 Toxicity Assessment 54
6.6.4 Risk Assessment Results . . 55
7.0 DESCRIPTION OF REMEDIAL ACTION ALTERNATIVES > ? 56
7.1 The "No Action" Alternative 56
7.2 The RCRA Cap Alternative , 58-
7.3 Incineration, Solidification/Fixation, and On-Site
Disposal ..... 59
7.4, Capping of Area A, Incineration and Solidification/
Fixation of Area B - 61
7.5 Off-Site Incineration and Off-Site Disposal 62
7.6 Comparison of the Alternatives 63
7.6.1 Overall Protection of Human Health and the
Environment « 65
7.6.2 Compliance with ARARs 65
7.6.3 Long-Term Effectiveness and Permanence 65
7.6.4 Reduction of Toxicity, Mobility, or Volume Through
Treatment -- ... 65
7.6.5 Short-Term Effectiveness 66
7.6.6 Implementability ~ 66
7.6.7 Cost 66
7.6.8 State Acceptance -; ^66
7.6.9 Community Acceptance 66
8.0 THE SELECTED REMEDY '* 67
8.1 Remediation Goals 67
8.2 Attainment of Applicable or Relevant and Appropriate
Requirements of Environmental Laws 70
8.2.1 Soil, Sediment, and Source Materials ARARs 70
8.2.2 Ground Water/Surface Water ARARs 72
8.3 Cost-Effectiveness r-74
8.4 Utilization of Permanent Solutions and Alternative
Treatment Technologies (or Resource Recovery Technologies)
to the Maximum Extent Practicable -74
8.5 Preference for Treatment as a Principal Element 76
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Table of Contents, continued
LIST OP FIGURES
Figure Page
1 Site Location Map 2
2 Surface Soil Sample Locations 10
3 Subsurface Soil Sample Locations ------...... 14
4 Monitoring Well Locations 20
5 Surface Water Sample Locations 26
LIST OF TABLES
Table Page
1 Summary of Organic Compounds Detected in Study Area
Surface Soils 12
2 Summary of Metals Detected in Study Area Surface Soils 13
3 Summary of Organic Compounds Detected in Study Area
Subsurface Soils ........... ^7
4 Summary of Metals Detected in Study Area Subsurface Soils 19
5 Summary of Shallow Ground Water Contamination by Organic
Compounds, Study Area Monitoring Wells- June 1988 -- 22
6 Summary of Shallow Ground Water Contamination by Organic
Compounds, Study Area Monitoring Wells- December 1988 23
7 Summary of Shallow Ground-Water Contamination by Inorganic
Contaminants, Study Area Monitoring Wells 24
8 Summary of Study Area Surface Water Contamination by Organic
Compounds - 28
9 Summary of Study Area Surface-Water Contamination by Inorganic
Substances . . 30
10 Summary of Stream Sediment Contamination by Organic Compounds 32
11 Comparison of Study Area to Downstream Sediment Contamination
by Organic Compounds ....... . 34
12 Summary of Stream Sediment Contamination by Inorganic
Substances .... ..... 36
13 Comparison of Study Area to Downstream Sediment Contamination
by Inorganic Substances 37
14 Substances Exceeding Water Quality Criteria Levels 39
15 Summary of Health Effects Criteria for Chemicals of Potential
Concern .......- 47
16 Total Carcinogenic and Noncarcinogenic Risks for all Exposure
and Environmental Media Conditions - Current-Use Scenario 50
17 Total Carcinogenic and Noncarcinogenic Risks for all Exposure
and Environmental Media Conditions - Future-Use Scenario - 52
18a Comparison of Aquatic Toxicity Criteria to Concentrations of
Chemicals Found in Streams at Smith's Farm 57
18b Comparison of Assumed Sediment Quality Criteria to
Concentrations of Chemicals Found in Streams at Smith's Farm 57
19 Comparison of the Five Remedial Alternatives " 64
20 Action Levels for Soil and Sediments . 68
APPENDIX - RESPONSIVENESS SUMMARY
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RECORD OF DECISION
SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
SMITH'S FARM SITE- FIRST OPERABLE UNIT
BROOKS, KENTUCKY
1.0 INTRODUCTION
The Smith's Farm site was included on the National Priorities List
(NPL) in June 1986. An approximate 80-acre area of unpermitted drum
disposal at the site has been the subject of a Remedial Investigation
(RI) and Feasibility Study (FS). The RI/FS activities commenced in
July 1987 and were performed by the U.S. EPA Region IV (EPA) under
the direction of the EPA Remedial Project Manager (RPM). The RI
Report, which examines the quality of air, soil, surface water,
stream sediments, and shallow aquifer ground water at the site was
completed in January 1989. The draft FS Report, which develops and
examines alternatives for site remediation, was submitted to the
public information repository with the RI Report in March, 1989.
This Record of Decision has been prepared to summarize the remedial
alternative selection process and to present the selected remedial
alternative, in accordance with Section 113(k)(2)(B)(v) and Section
117(b) of the Comprehensive Environmental Response, Compensation and
Liability Act of 1980 (CERCLA) as amended by the Super fund Amendments
and Reauthorization Act (SARA) (P.L. 99-499). The Administrative
Record for the Smith's Farm site forms the basis for the Record of
Decision contained herein.
-1.1 Site Location and Description
The Smith's Fani site is a 560-acre property located in a rural area .
of Bullitt County, Kentucky approximately 1.5 miles southwest of
Brooks, Kentucky. The site is located at an approximate latitude
38* 02' 45" and longitude 85" 44' 00" (Figure 1).
The site is bordered on the north, east, and west by forested hills
and on the south by a residential area along Pryor Valley Road.
Within the Smith's Farm property, there is a 37.5-acre landfill that,
until recently, was permitted by the Commonwealth of Kentucky for the
disposal of solid waste. The site also includes an approximate
80-acre area (Study Area) where the unpermitted disposal of drums
containing hazardous waste has occurred over a 20-year period. This.
80-acre area is the focus of the first operable unit RI/FS for which
this Record of Decision is written. The 37,5-acre landfill will be
the subject of a second operable unit RI/FS.
The Study Area is on a mile-long ridge between two intermittent
creeks. These two creeks drain into an unnamed tributary which flows
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SOURCE:PROPERTY TAX MAP
/ PERMITTED
\LANDFILL.
\
Source: RI Report
SMITH'S FARM '
SITE MAP .
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FIGURE
1
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south to Bluelick Creek. Bluelick Creek flows southeast into Floyd's,
Fork, which flows into Salt Lick River and eventually into the Ohio
River to the northeast. -
1.2 Site History
The Smith's Farm site was owned by Mr. Leonard 0. Smith, Sr. until
his death in 1969. The permitted landfill was operated by; Smith and
his son, Mr. Harlan Smith, who continued the landfill operation until
his death in 1978. The landfill operations began in the late 1950's;
the landfill was first permitted by the Commonwealth of Kentucky in
1973. The current owner of the landfill is Mrs. Mary Ruth Smith,
whose nephew operated the permitted landfill.
According to records on file with the Kentucky Department for
Environmental Protection, a 1969 site inspection by the Kentucky
Department of Health noted a large volume of uncovered industrial
waste was present in the area of the permitted landfill. A 1972
inspection noted that the landfill site was in poor condition with a
large volume of industrial waste being disposed of at the landfill.
Following its permitting in 1973, the Commonwealth of Kentucky
approved the disposal of a variety of industrial wastes into Smith's
landfill. On several occasions following the landfill permitting,
the landfill was inspected by representatives of the Kentucky Natural
Resources and Environmental Protection Cabinet (NREPC). At various
times following the initial landfill permitting, the landfill owner
was cited by the Commonwealth for violation of solid waste disposal
regulations.
Over a 20-year period, numerous drums containing various amounts and
types of hazardous substances were disposed of in several areas on
the Smith's Farm property north of the permitted landfill. In 1979
and again in 1981, EPA conducted limited investigations of the
Smith's Farm site, including some unpermitted disposal areas. These
initial investigations did not uncover a serious environmental hazard
at this site, and an initial 1982 hazard ranking score for the
Smith's Farm site was well below the cutoff level of 28.5 for
inclusion on the National Priorities List (NPL) of Superfund sites.
The NREPC surveyed the unpermitted drum disposal area of the Smith's
Farm site in February 1983, and the investigators suspected that a
substantial number of drums had been disposed of at the site. The
Commonwealth of Kentucky subsequently requested that EPA investigate
the site. In April 1983, the NUS Corporation, under contract to EPA,
conducted a magnetometer survey of suspected drum disposal areas on
the Smith's Farm property. This survey gave the first indication of
the .location and the areal extent of probable drum disposal areas in
the unpermitted portion of the site. :
Following the 1983 magnetometer survey, the Study Area was visited in
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April 1984 by representatives of EPA'a Emergency Response and Control
Section and EPA's Environmental Response Team, EPA's Technical
Assistance Team, and the Kentucky Department for Environmental
Protection. Samples of waste from several drums were collected in an
effort to determine if the site warranted consideration for Superfund
cleanup. The investigation revealed that the potential for the
release of hazardous chemicals from the drums represented an imminent
and substantial endangerment to public health and the environment
Therefore, the site qualified for immediate removal funds,
considering the regulations in the National Oil and Hazardous
Substances Pollution Contingency Plan (40 CFR Part 300 Section
300.65).
In June 1984, the immediate removal of surface drums containing
hazardous wastes began. This emergency response action continued
until mid-August 1984. The following quantities of waste were
removed in this action:
- 6,000 drums were removed from the surface
- 2,000 of these drums contained hazardous waste
- 200 drums contained PCB contaminated wastes
- 15,000 gallons of flammable liquids were removed
In October 1984, the Smith's Farm site was proposed once again for
listing on the NPL. Both the ground water and surface water pathways
received a higher score than the previous ranking in 1982 because of
the identification of targets (ground and surface-water users
potentially affected by site releases) in the 1984 ranking. In June
1986, the Smith's Farm site was included on the NPL.
Between June 1986 and July 1987, EPA conducted various activities
related to the notification and investigation of Smith's Farm
potentially responsible parties (PRPs). In July, 1987, the RI/FS
activities for the Smith's Farm site began.
Both the RI and FS Reports were submitted in draft form to the public
information repository in March 1989.. As required under Section 117
(a) of CERCLA, as amended by SARA, the Proposed Plan for the Smith's
Farm site was prepared and.sent to interested parties in late March
1989. Following its distribution, a public meeting to present and
discuss EPA's preferred remedial alternative for Operable Unit 01 was
.held on April 1L, 1989. A review period for public comment on the
preferred alternative extended from April 11 to May 2, 1989.
2.0 ENFORCEMENT ANALYSIS
Potentially Responsible Parties (PRPs) were notified of EPA's
immediate removal action at the Smith's Farm site in June 1984. In
March 1987, PRPs were notified of EPA's intent to initiate RI/FS
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activities at the Smith's Farm site. In both cases, the identified
PRPs declined to participate in activities at the site. The 1984
removal action and the subsequent RI/FS have, therefore, been EPA-
lead proceedings. On October 20, 1987, prior to initiating the RI
field work, EPA held a meeting in Atlanta to discuss the site status
with the PRPs.
On March 15, 1989, at the request of PRPs, EPA held a meeting with
PRPs to discuss possible PRP involvement in the current and future
site activities regarding both the first operable unit RI/FS and a
planned second operable unit RI/FS at Smith's Farm. The second
operable unit RI/FS is planned for this site to address deep ground
water, the permitted landfill, and additional areas of suspected drum
disposal identified in the first RI/FS. Notice letters concerning
this second RI/FS have been sent to the Smith's Farm PRPs, inviting
their participation in this RI/FS.
Upon completion of the first operable unit RI/FS of the Smith's Farm
site, EPA will begin the implementation of the Remedial Design (RO)
and the Remedial Action (RA) phases of the first operable unit.
After selection of the first operable unit RI/FS remedy, RD/RA notice
letters will be sent to PRPs identified for the Smith's Farm site;
EPA may issue a CERCLA Section 106 Order to the PRPs to perform the
RD/RA,
If the identified PRPs decline to participate in either the second
operable unit RI/FS or the RD/RA for the first operable unit, EPA
will perform the RI/FS and RD/RA and seek to recover costs at a later
date. In June 1989, EPA sent demand letters to PRPs to recover
response costs from the removal action in 1984.
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
The RI/FS Reports were released to the public in March 1989 and the
Proposed Plan announcing EPA's preferred alternative (Alternative #4)
for site remediation was released to the public on April 3, 1989.
These two documents were made available to the public through the
public information repository that has been established at the
Ridgeway Memorial Library, Shepherdsvilie, Kentucky, and at EPA
Region IV. The notice of availability of these documents was
published in the-Proposed Plan Fact Sheet and in the Louisville
Courier-Journal on April 6, 1989. Prior to release of the RI/FS
Reports, an active effort was made on behalf of EPA to inform
interested parties of EPA's activities at the site, which included a
March 2, 1988 public meeting at which EPA announced plans for
conducting the Remedial Investigation. A February 28 publication in
the Louisville Courier-Journal and release of fact sheets notified
the public of this meeting.
A public comment period on EPA's preferred remedial alternative was
held from April 11 through May 2, 1989. Additionally, a public
meeting was held on April 11, 1989. At this meeting, representatives
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from EPA Region IV answered questions about problems at the site,
remedial alternatives considered, and the preferred remedial
alternative. A response to the comments received during this period
is included in the Responsiveness Summary, which is a part of this
Record of Decision. This decision document presents the selected
remedial action for the Smith's Farm Site Operable Unit 01, in
Brooks, Kentucky, chosen in accordance with CERCLA, as amended by
SARA and, to the extent practicable, the National Contingency Plan.
The decision for this site is based on the administrative record,
which has also been established in the public information repository
(Ridgeway Memorial Library) and in the EPA Region IV office.
4.0 SCOPE AND ROLE OF OPERABLE UNIT
Under certain circumstances, mitigation of the threat(s) posed by a
Superfund site can be more effectively dealt with in stages, or
operable units. The Smith's Farm site is approximately 560 acres,
which includes an approximate 80-acre area of unpermitted drum
disposal, a 37.5-acre permitted solid waste disposal landfill, and,
as determined in the RI/FS, additional areas of suspected drum
disposal. In the Summer of 1987, EPA Region IV and the Commonwealth
of Kentucky defined an area (the 80-acre unpermitted drum disposa^
Study Area) that deserved immediate attention in the form of an
RI/FS. This area appeared to be the most serious threat at the site
based on the voluminous drums in this area and suspected waste types
present. Other areas of the 560-acre property would be evaluated at
a later date if the RI/FS established a need for a subsequent
investigation.
During the Spring of 1988 (during the RI field sampling program),
EPA elected to defer evaluation of the deep aquifers beneath the
site due to the complexities of, and time associated with,
implementation of such a program at this site, and the premise that
site contaminants were being transported primarily by surface water
runoff and through the surficial aquifer. (Sampling of private
drinking water supplies in the vicinity of the'Smith's Farm site has
been performed on a quarterly basis since the Spring of 1988 and no
degradation of water quality in these supplies as a result of the
Smith's Farm site has been detected). Additionally, in the Spring
of 1989, the Commonwealth of Kentucky informed EPA Region IV of its
decision not to renew the Smith's Landfill solid waste disposal
permit and requested EPA to conduct an RI/FS of the landfill area.
Operable Unit 01, authorized by this Record of Decision, addresses
the contaminated soils, sediments, surficial aquifer, and drums of
-6-
-------
the 80-acre unpermitted drum disposal area. Operable Unit 02
(anticipated initiation of Operable Unit 02 is by December 1989)
will address the remaining potential threats associated with the
Smith's Farm site which include the afore-mentioned Smith's
permitted landfill/ deep ground water aquifers, and other suspected
areas of drum disposal. During design of the selected remedy,
information obtained through Operable Unit 02 (e.g., deep ground
water aquifer data) will be evaluated against the components of
Alternative 4 to insure that Alternatve 4 remains consistent, in
light of the additional information, with the anticipated absence of
a deep aquifer ground water exposure pathway. Until such
information is obtained, however, quarterly monitoring of private
drinking water supplies will be performed by EPA to insure the
integrity of the resident's water supply. It is anticipated that
Operable Unit 02 will be the final response action for the Smith's
Farm site.
5.0 CURRENT SITE STATUS
5.1 Environmental Setting
5.1.1 Bedrock/Geology
Underlying the Smith's Farm site is the Mississippian-age Borden
Formation, which in descending order includes the Holtzclaw
Siltstone Member, the Nancy Member (silty shale), the Kenwood
Siltstone Member and the New Providence Shale Member. The depth to
bedrock onsite is commonly four to six feet, and rock outcrops at
Smith's Farm have been observed. Underlying the Borden Formation is
the Devonian-age New Albany shale, which overlies the Silurian-age
Louisville Limestone. The Silurian and Devonian-age rocks crop out
approximately one mile east of the Smith's Farm site.
The rocks underlying the site are nearly horizontal; the regional
dip of the top of the New Albany shale is to the west at about 110
feet per mile. No faults have been mapped by the U.S. Geological
Survey in this part of Kentucky. Some joints and possibly
small-scale faults are expected to be present in the rocks
underlying the site.
5.1.2 Soils
Soils of the area are loamy on the slopes and ridges, and gravelly
loam in the small tributary floodplains of the site. Soils are
either the product of weathering of the underlying bedrock, or are
derived from material washed downslope from nearby source areas.
-7-
-------
5.1.3 Hydrogeology
The shallow hydrogeology of the Smith's Farm site was defined to
some extent by the RI fieldwork, and from references cited in the RI
report. Ground water is found in the residual soil, which
constitutes a very poor, unconfined aquifer. Yields to wells would
generally not be sufficient for domestic use. Ground-water flow in
this aquifer is controlled by topography and the nature of the
underlying bedrock surface.
Beneath the saturated part of the soil profile, ground water occurs
primarily in joints or bedding planes in the shale. Yields in the
shaley rock would not be expected to be great anywhere, although
zones of bedrock Jointing yield appreciably more water to wells than
the less fractured rock. The RI report notes that most of the
residential wells in the vicinity of the Smith's Farm site are
completed into the shallow (shaley) bedrock. The degree of
hydraulic connection between the saturated zone in the soil and in
the underlying shale has not been established in the RI. According
to local residents, ground water derived from the shaley aquifer is
saline and contains excessive iron and sulfur.
. \
Underlying the shale is a confined limestone aquifer. This aquifer
is generally more productive than the overlying shale, especially in
favorable topographic or hydrogeologic settings. . The water quality
in this aquifer is also poor. One resident has been identified near
the Smith's Farm site who obtains water from the limestone aquifer.
The nature of ground-water flow in the bedrock aquifers was not
investigated during the first operable unit RI/FS; therefore, no
information is yet available concerning any potential ground-water
contamination in these aquifers caused by waste disposal on the
Smith's Farm property.
5.1.4 Surface Water and Topography
The Study Area of the first operable unit RI/FS is defined by a
narrow, steeply-sloping ridge bounded by two first-order streams.
The maximum relief in the Study Area exceeds 150 feet. The slope on
the steeper northeast side of the ridge is approximately 50% in some
areas. Observations made during the RI fieldwork indicate that the
two streams bounding the site dry up during periods of minimal
precipitation. Baseflow runoff in these streams is low during even
short dry periods because of the limited recharge area, thin
saturated soil zone, and the low permeability of the shale.
-8-
-------
5.2 Study Area Contamination
5.2.1 Surface Soil Contamination
As part of the RI, samples were taken at several locations in the
Study Area (Figure 2) in order to define the nature and extent of
surface soil contamination. Surface soil sample locations were in
areas of apparent contamination and/or areas of potential human
exposure to contaminants. Additional samples were taken outside
areas of known or suspected waste disposal at the Smith's Farm site
to establish background conditions.
The surface soil sampling protocol is documented in the RI report.
Surface soil samples were tested to determine their concentrations
of volatile and extractable organics and inorganic parameters (EPA's
"full scan" list).
Of the 10 samples collected from suspected contaminated areas, all
but one showed contamination from organic compounds. Most of these
samples contained concentrations of PCBs ranging from 1 mg/kg to 200
mg/kg. Surface soils in the Study Area also appear to generally be
contaminated by one or more extractable organic compounds, primarily
phthalates. Volatile organic contamination of surface soils appears
to be minor, or is less areally .extensive than contamination by
several other organic compounds. A summary of the organic compounds
detected in surface soils is presented in Table 1.
The background surface soil samples were uncontaminated, except that
low levels of toluene were found in each sample. The toluene
concentrations in these and other samples is questionable, but
probably is not indicative of background concentrations.
Surface soil contamination by inorganic parameters was also
documented for some of the Study Area sample locations. Metals that
significantly exceeded background concentrations include barium,
chromium, iron, lead, and nickel. Cyanide was found in 5 of 11
Study Area samples but was absent in background samples. A summary
of the metals detected in surface soil samples is presented in Table
2.
5.2.2 Subsurface Soil Contamination
Subsurface soil samples were also collected in and around the Study
Area. These samples were collected using a split-spoon sampler.
Sample locations were selected using data from (1) the magnetometer
survey; (2) a soil gas survey where organic vapors in soils were
measured around the Study Area; (3) seep sampling; and.(4)
topographic data or other evaluation. Soil borings in the Study
-9s-
-------
SOIL SAMPLE
LOCATION
-SCALE
tf 2CO'
Source: RI Report
SMITH'S FARM'
SURRCIAL SOIL SAMPLE LOCATIONS IN THE
VICINITY OF THE STUDY AREA
-10-
-------
Area were located downs lope of the known or probable areas of drum
disposal.
Soil borings were also made in background locations and in areas
outside the Study Area. These borings were selected to either
establish background concentrations in subsurface soils, to
determine the nature and extent of contaminant migration outside the
Study Area, or to evaluate contamination from potential sources
located outside the Study Area.
The field sampling protocol for the subsurface soil sampling is
presented in the RI report. Samples were selected for analysis and
sent to an approved laboratory to determine concentrations of all
substances on the target compound list.
Study Area soil boring locations are shown in Figure 3. For
discussion purposes, the results of the soil boring analyses will be
considered for separate areas of the site.
5.2.2.1 Area C
V
Samples were collected adjacent to or upslope of this area of
potential drum disposal, or in locations near the small streams that
are upstream of any potential influence from Area C. The RI report
concludes that subsurface soils in the vicinity of Area C are
uncdntaminated. This conclusion is made notwithstanding the
presence of pentachlorophenol at an estimated concentration Of 2000
ug/kg in one sample near Area C and a concentration of 2500 ug/kg of
acetone in another split spoon sample. The conclusion that these
sample results are anomalous is based upon visual .observations of
the site and of magnetometer results from this part of the Study
Area.
5.2.2.2 Area B
Highly variable sample results were obtained from four soil borings
in Area B. In one soil boring, collected near an area of apparent
leachate seepage, the split spoon samples that were analyzed shov/ed
subsurface soil contamination by. eight volatile organic compounds,
as well as two extractable organics. Sample concentrations were
generally low, but one sample contained acetone at an estimated
concentration of~ 14,000 ug/kg. A second soil boring located just
downs lope of an area of drum disposal showed subsurface soil
contamination by a variety of organic compounds including PCBs,
volatile and extractable organic compounds. Another subsurface soil
sample had a very low level of di-n-butyl phthalate present. The
-11-
-------
TABLE 1
SUMMARY OF ORGANIC COMPOUNDS DETECTED IN STUDY AREA SURFACE SOILS
SMITH'S FARM SITE
Chemical
1,1-Dichloroethane
1,2-Dichloroethene
Trichloroethene
Toluene
Ethyl Benzene
Total Xylenes
3 and/or 4-Methyl
Phenol
Isophorone
Naphthalene
2-Methylnaphthalene
Dimethyl Phthalate
Di-N Butylphthalate
Pyrene
Benzyl Butyl
Pththalate
Bis (2-Ethylhexyl)
Phthalate
Di-N-Octylphthalate
PCB-1248
PCB-1254
PCB-1260
Frequency
of
Detection
1/18
1/18
1/18
7/18
1/18
1/18
1/18
2/18
3/18
3/18
1/18
5/18
1/18
2/18
5/18
1/18
2/18
7/18
4/18
Min.-Max.
(UQ/ka)
ND-3J
ND-74
ND-4J
ND-260
ND-71
ND-32000
ND-450J
ND-1200
ND-580
ND-500
ND-82J
ND-370
ND-48J
ND-72J
ND-4200J .
ND-75J
ND-200,000
ND-7200
ND-1500
Geometric
Mean
rua/ko}
2
38
2
83
37
130
180
180
170
170
43
170
25
37
1805
39
150
190
180
Background
Concentration
/ .._ /!-_ \ +
(ug/kol
ND
ND
ND
140
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
notes
-For calculations, duplicate samples were averaged to determine a
location's concentration.
-The geometric .mean was calculated using a value of either 1/2 the
detection limit or 1/2 the minimum estimated value if it is less tha
the detection limit, for all non-detect samples
-J indicates an estimated value '
-ND indicates nondetection
+ Geometric mean of background concentrations
*Frequency of detection is the number of samples with detectable
concentrations over the total number of samples
-12-
-------
TABLE 2
SUMMARY OF METALS DETECTED IN STUDY AREA SURFACE SOILS
SMITH'S FARM SITE
Metal
Aluminum
Antimony
Barium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Vanadium
Zinc
Cyanide"*"*
Frequency
of
Detection
19/19
1/7
19/19
3/19
2/19
12/19
2/19
. 1/19
19/19
16/19
1/19
19/19
12/19
19/19
6/19
12/19
4/19
2/19
18/19
8/19
5/11
Min . -Max .
f mo/ ken
6200-19000
ND-120JN
34-6700
ND-2.4
ND-140000
22-160
21
ND-200
18000-53000
9.5J-8900J
ND-40000
160-820
ND-0 . 5 JN
9.2-52
ND-4400
ND-1.8J
ND-3.8J
ND-86000
ND-34
ND-540J
ND-10
Geometric
Mean
(mo/ kg)
12000
16
150
0.56
610
25
10
11
33000
55
2100
270
0.26
23
1200
0.68
1.0
110
21
91
.56
Background
Concentration
( ma/ka \+
11000
ND
48
ND
ND
ND
ND
ND
16000
20
ND
150
ND
12
ND
0.57
ND
ND
21
ND
ND
notes
-For calculations, duplicate samples were averaged to determine a
location's concentration .
-The geometric mean concentration was calculated using a value of I/
the detection limit for all nondetect samples (with the exception of
background samples)
-J indicates an estimated value "
-N means that there is presumptive evidence of the presence of the
substance ~
ND indicates nondetection
(Geometric mean of background concentrations
* Frequency of detection is the number of samples with detectable
concentrations over the total number of samples
++Cyanide was the only non-metal inorganic tested.
. -13-
-------
RdC3
STREAMS
STUDY
AREA
3CUNCARY
SOIL
BORING
LOCATION
Source: RI Report
SMITH'S FARM
SOIL BORING LOCATIONS IN THE VICINITY OF
THE -STUDY AREA
-------
fourth subsurface soil sample in the vicinity of Area B contained no
organic compounds. A comparison of subsurface soil concentrations
of inorganics in the Area B borings to inorganic parameter
concentrations in background subsurface soil samples (SB-16 and
SB-11) indicates that Area B subsurface soil contamination from
inorganics is inconsequential or inconclusive.
5.2.2.3 Area A
Seven soil borings were made around the margin of Area A. Similar
to the subsurface soil samples from around Area B, the subsurface
soil samples from around Area A showed varying degrees of
contamination. Three samples showed no evidence of any
contamination. Two samples had concentrations of total PCBs at
close to 4 mg/kg. Another sample had a concentration of acetone at
1.8 mg/kg and 1 ug/kg of benzene. The other sample had low
concentrations of two organic compounds present. Generally, organic
contamination of the subsurface soils was greater closer to the
surface rather than deeper in the soil.
Inorganic contamination of subsurface soils around Area A was
generally either not present or was insignificant. Individual
borings had elevated concentrations of some metals compared to
background levels, but this is generally not the case.
5.2.2.4 Other Areas
In addition to sampling the periphery of suspected disposal areas,
soil borings were taken in several downslope Study Area locations as
well as from near the unnamed tributary, just outside the Study
Area. Samples taken near the streams along the marginu of the Study
Area and downstream from the suspected disposal areas (SH-7, SB-2,
SB-15, SB-8 and SB-9) did not indicate contamination. Samples from
boring SB-10 indicated contamination potentially attributable to a
nearby localized area of drum or refuse dumping. Further
downstream, samples from boring SB-20 did not indicate subsurface
soil contamination, while samples collected downstream from SB-20
did indicate contamination of subsurface soils. This contamination
appears to be attributable to either the permitted landfill or to
some other possible source(s) of contamination outside of the Study
Area. - :
5.2.2.5 Summary of Subsurface Soil Contamination
Summary data concerning subsurface soil contamination are presented
in Tables 3 and 4. Localized areas of subsurface soil contamination
are present in the vicinity of Areas A and B. Based upon the
-15-
-------
available data, subsurface soil contamination appears to be primarily
restricted to areas in close proximity to drum disposal locations.
PCBs were found in concentrations greater than 1 mg/kg downslope of
both Area A and Area B. Concentrations of acetone exceeding £ mg/kg
were found in samples downslope of Area A and Area B. Contaminant
sources (probably the permitted landfill) on the Smith's Farm;
property outside the Study Area have caused subsurface soil :
contamination in some locations. Subsurface soil contamination tends
to be in shallow rather than deep locations, particularly for the
less soluble extractable organic compounds. v
5.2.3 Ground-Water Contamination >
Ground-water investigations as a part of the RI have been restricted
to the uppermost aquifer or saturated zone. Shallow monitoring wells
were installed within, and outside of, the Study Area. Well drilling
locations were selected based on several factors such as site ^
accessibility, results of the magnetometer and soil gas surveys, and
observed areas of contamination. 4
~'~~* -
Ground-water samples were collected in June 1988 and again in '-:
December, 1988. Depending on the yield of the well, some or all of
the following contaminant classes were monitored during the June
sampling effort: volatile organics, metals, extractable organics,
PCBs/pesticides, and cyanide. Only organic compounds were checked in
the December sampling effort. All sampling was in accordance with
EPA Region IV standard operating procedures. Details of the June.
well sampling are found in the RI report. December sample data are
included as an addendum to the RI report.
5.2.3.1 Sampling Results and Data Analysis :]
Monitoring wells were generally installed in close proximity to the
two streams at the margins of the Study Area ("East" and "West"
creeks) and along the Unnamed Tributary south o-f the Study Area
(Figure 4). Of the seven wells along the West Creek which were.
sampled in June, only the two wells adjacent to Area A showed -""A
detectable levels of contamination in the shallow ground water
(MW-05; MW-06). A third well (MW-8) south of Area A and near the
confluence of West Creek and the Unnamed Tributary contained an
estimated 200 ug/L of acetone. Near the East Creek, well MW-11 near
Area B yielded ground water containing three volatile organic
compounds. Well MW-15 is located in the south-central part of the
Study Area, downgradient from Area A and approximately
-16-
-------
TABLE 3
SUMMARY OP ORGANIC COMPOUNDS DETECTED IN STUDY AREA SUBSURFACE SOI
SMITH'S FARM SITE
Chemical
Acetone(0-4 ft)
(>4 ft)
1,2 Dichloroethane
(0-4 ft)
(>4 ft)
Methyl Ethyl Ketone
(0-4 ft)
(>4 ft)
Trichloroethene
(0-4 ft)
(>4 ft)
1,1,2-Trichloro-
ethane (0-4 ft)
(>4 ft)
Benzene(0-4 ft)
(>4 ft)
Methyl Isobutyl
Ketone (0-4 ft)
(>4 ft)
Tetrachloro-
ethene (0-4 ft)
(>4 ft)
Toluene(0-4 ft)
(>4 ft) .
Ethylbenzene
(0-4 ft)
(>4 ft)
Total xylenes
(0-4 ft)
(>4 ft)
Frequency
of
Detection
2/19
1/7
2/19
1/7
0/19
2/19
1/7
0/19
1/7
1/19
0/7
0/19
1/7
0/19
1/7
1/19
0/7
0/19
1/7
1/19
1/7
Min.-Max,
fug/kgi
ND-14000J
ND-1250J
ND-6J
ND-9J
ND
ND-6J
ND-25
125.5J
ND
ND-2.5J
ND-1J
ND
ND
ND-215J
ND
ND-3.5J
ND-14
ND
ND
ND-70
ND-2J
ND-450
notes
Geometric
Mean C
fug/kg lv
24 r
25 ?
3 .?
3.5 c;
7.7
3.7
5.1
3«7
0.5
10
3.1
7.3
4.7
i
6.1
Background
Concentration
fua/kcn
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
** For certain locations, multiple samples were collected within the
given depth .intervals and are averaged in this table
* Frequency of detection is the number of samples with detectable
concentrations over the total number of samples
The geometric mean was calculated using a value of either 1/2 the
detection limit or 1/2 the minimum estimated value,, for all nondetec
samples (with the exception of background samples)
-J indicates an estimated value
-ND indicates nondetection
table continued on the following page
-17-
-------
Table 3 continued
Chemical
(3 &/or 4) Methyl-
phenol (0-4 ft)
(>4 ft)
Naphthalene
(0-4 ft)
(>4 ft)
2-Methylnapthalene
(0-2 ft)
(>4 ft)
Benzyl Butyl
Phthalate
(0-4 ft)
(>4 ft)
Di-N Butyl-
Phthalate
(0-4 ft)
(>4 ft)
Bis(2-Ethylhexyl)
Phthalate
(0-4 ft)
(>4 ft)
Di-N-Octylpht;halate
(0-4 ft)
(>4 ft)
PCB 1248
(0-4 ft)
(>4 ft)
PCB 1254
(0-4 ft)
(>4 ft)
PCB 1260
(0-4 ft)
(>4 ft)
Frequency
of ,
Detection
2/19
0/7
1/19
1/7
2/19
0/7
1/19
0/7
1/19
0/7
2/19
0/7
1/19
0/7
1/19
0/7
1/19
0/7
3/19
0/7
(ug/kgl
46J-&4J
ND ;v
ND-180J
ND-28J
ND-120J
ND v
ND-1000
ND-27^5
ND K
ND-2200
ND
ND-44J
ND
ND-2700
ND ^
ND-1700
ND "/
ND-2350
ND .v.
notes
Geometric
Mean
(ug/kgl
25
31
28
16
218
14
245
23
61
116
131
Background
Concentration
fug/kg1
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
** For certain locations, multiple samples were collected for given
depth intervals and are averaged for this table
* Frequency of detection is the number of samples with detectable
concentrations over the total number of samples - ':
The geometric mean was calculated using'a value of either 1/2 the
detection limit or 1/2 the minimum estimated value, for all
nondetect samples (with the exception of background samples)
-J indicates an estimated value
-ND indicates nondetection
-18-
-------
' TABLE 4
SUMMARY OF METALS DETECTED IN STUDY AREA SUBSURFACE SOILS
SMITH'S FARM SITE
Metal
Aluminum
Antimony
Arsenic
Barium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Vanadium
Zinc
Cyanide"1"1"
Frequency
of ^
Detection
19/19
1/14
19/19
19/19
8/19
10/19
19/19
19/19 .
9/19
19/19
18/18
19/19
19/19
0/19
19/19
14/19
0/19
2/19
0/19
19/19
19/19
2/19
.' "; .-
Min .^Max .
fmg/kcn
9200-16333J
ND-19J
5. 1-22. 7 JN
23-646
ND-13.4JN
ND-3690
15-63 :,.
6.8-26.3
ND-158
22000^76500
6.9-482
3100^5670
230-1200
ND ~
18-80
ND-2000
ND
ND-3.1
ND
20-53
21.5-1275
ND-1.2
.Geometric
Mean
(ma/ka)
13460
4.6
11.8
67
1.7
160
23
17
8.8
36700
14.6
3760
620
ND
32
550
ND
1.7
ND
28
83
0.45
Background
Concentration
XSJSZkgJ.
11806
ND
12.2
55
8.1
31
17.5
14
ND
26800
7.7
3240
450
ND
24.9
520
ND
ND
ND
26
49.6
ND
notes
-For certain locations, multiple samples were collected
and these samples are averaged for this table
-The geometric mean concentration was calculated using a
value of either 1/2 the detection limit or 1/2 the lowest
estimated concentration for all nondetect samples
-J indicates an estimated value
-N means that there is presumptive evidence of the
presence of the substance
ND indicates nondetection "<'"
(Geometric mean of background-concentrations
^Frequency of detection is the number of samples with
detectable concentrations over the total number of
samples
++Cyanide was the only non-metal inorganic tested
-19-
-------
RCAOS
STREAMS
STUDY
AREA
BOUNDARY
MW "MONITORING
WELL
LOCATION
SCALE-
2CC31
FIGURE
4
Sourc^: RI Report
SMITH'S FARM
MONITORING WELL LOCATIONS IN THE
VICINITY OF THE STUDY AREA
-------
equidistant between the East and West Creeks. This well yielded
water containing several organic compounds. This well is located
just downs lope of an area of drum disposal.
Data from the December 1988 sampling indicate a somewhat different
pattern of ground-water contamination by organic compounds. Several
wells that yielded ground water containing no detectable levels of
contmaination when sampled in June yielded ground water containing
one or more organic compounds when resampled in December. The
December samples from background wells MW-01 and MW-09 both contained
low levels of toluene. This anomaly may be a result of laboratory
contamination or some other source of error; no other contaminants
were found in the samples from these wells. Wells MW-05, MW-11 and
MW-15, which showed the greatest degree of contamination in June,
also yielded ground water containing several volatile organic
compounds in December, but the concentrations and some of the
specific compounds detected differed from what was found in June.
A summary of organic contamination in shallow ground water in the
Study Area is presented in Tables 5 and 6.
Contamination of the shallow ground water by inorganic substances *
(essentially metals) was noted by a comparison of background wells
(MW-1 and MW-9) to wells adjacent to or downgradient of drum disposal
areas. Along the East Creek, none of the wells contained significant
levies of inorganic compounds. A summary of the relevant
ground-water quality data for inorganics from Study Area wells is
given in Table 7. From Table 7, it appears that ground water from
well MW-06 contains aluminum, arsenic, barium, cadmium, calcium,
chromium, cobalt, iron, lead, magnesium, manganese, nickel,
potassium, vanadium, and zinc in concentrations greater than
background. Well MW-05 contains calcium/ magnesium, and sodium :.n
greater than background concentrations.
5.2.3.2 Summary of Ground-Water Data . .
Ground-water contamination is present in the upper part of the
saturated zone, beneath and adjacent to drum disposal locations in
the Study Area. Shallow ground water is primarily contaminated by
volatile organic:compounds. Federal primary drinking water standard
MCLs were exceeded in a few of the shallow ground-water samples (see.
Table 1). In a -few locations( the shallow ground water contains
significant concentrations of metals, including some primary drinking
water standard metals in concentrations exceeding MCLs. From drum
disposal areas, shallow ground water flows only a short distance
before either discharging as surface seeps or directly into the small
streams that border the drum disposal locations. The nature of.
deeper aquifer contamination from the Study Area has not been
investigated during the first Operable Unit.
-21-
-------
TABLE 5
SUMMARY OP SHALLOW GROUND-WATER CONTAMINATION BY ORGANIC COMPOUNDS
STUDY AREA MONITORING WELLS- JUNE, 1988
SMITH'S FARM SITE
Contaminant
Acetone
Benzene
Carbon Disulfide
1,1 Dichloroethane
1,2 Dichloroethene
Di-Nbutylphthalate
Trichloroethene
Vinyl Chloride
Well in Which Detected and Concentration (ug/L)
MW-05
ND
ND
2J
NDA
80*
ND,
ND
150
MW-06+
290J
ND
ND
ND
ND
ND
ND
ND
MW-08+
200J
ND
ND
ND
ND
ND
ND
ND
MW-11
ND
ND
ND
ND
70
ND
56
19
MW-15
ND
2J
ND
27
70
6J
18
10
notes
+ Because of the low yield of the well, no extractable organics
sample was collected
* The concentration given in the table is the average of two
duplicate samples taken from the well
J indicates an estimated value
ND indicates none detected
the background concentration of all organic compounds is ND ._
-22-
-------
TABLE 6
SUMMARY OF SHALLOW GROUND-WATER CONTAMINATION BY ORGANIC COMPOUNDS
STUDY AREA MONITORING WELLS- DECEMBER, 1988
SMITH'S FARM SITE
Contaminant
Carbon Disulfide
1,1 Dichloroethane
1,1 Dichloroethene
1,2 Dichloroethene
Trichloroethene
Chloroethane
Benzene
Toluene
Bromochloroethane
Vinyl Chloride
PCB 1260
Unidentified Total
Extractable Organics
Well in Which Detected and Concentration (ug/L)
MW-01 MW-02 MW-03 MW-05 MW-06 MW-07
ND
ND
ND
ND
ND
ND
ND
6
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.88J
ND
ND
ND
ND
ND
ND
ND
3J
ND
ND
ND
ND
50
ND
ND
ND
92
ND
ND
ND
ND
10JN
ND
ND
ND
3J
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
4J
ND
ND
ND
ND
ND
ND
4J
ND
ND
ND
ND
Well in Which Detected and Concentration (ug/L)
Contaminant
Carbon Disulfide
1,1 Dichloroethane
1,1 Dichloroethene
1,2 Dichloroethene
Trichloroethene
Chloroethane
Benzene
Toluene
Bromochloroethane
Vinyl Chloride
PCB 1260.
Unidentified Total
Extractable Organics
MW-08
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
..
20J
MW-09
ND
ND
ND
ND
ND
ND
ND
14
ND
ND
ND
ND
MW-10
52
ND
ND
ND
ND
ND-
ND
6
ND
ND
ND
ND
MW-11
ND
1J
2J
230
110
ND
ND
1J
30JN
150
ND
40J
MW-13
10
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
MW014
3J
ND
ND
ND
ND
ND
ND
4J
ND
ND
ND
ND
MW-15
34
25
ND
36.5
8
20
2J
0.5J
ND
22
ND
200J
notes
J indicates an estimated value
ND indicates none detected
+ Concentration given in the table is the average of two duplicate
samples
MW-01 and MW-09 are background monitoring wells
-23-
-------
TABLE 7
SUMMARY OF SHALLOW GROUND-WATER CONTAMINATION BY INORGANICS
STUDY AREA MONITORING WELLS- JUNE, 1988
SMITH'S FARM SITE
Contaminant
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Thallium
Vanadium
Zinc
Cyanide
Well in Which Detected
MW-01 MW-09
19000
ND
10
55
ND
ND
56000
45
ND
150
51000
13
46000
730
ND
75
17000
ND
ND
130000
ND
30
250J
ND
6200
ND
ND
56
ND
ND
14000
14
ND
11
17000
10
14000
700
ND
34
2500
ND
ND
110000
ND
ND
84 J
ND
and Concentration (ug/L)
MW-05"*" MW-06
1950
ND
ND
16
ND
ND
275000
8
ND
ND
7900
2
185000
850
ND
ND
17000
ND
ND
505000
ND
ND
115J
ND
62000
ND
43
200
ND
7
110000
3200
150
250
170000
94
81000
5200
ND
2000
34000
ND
ND
110000
ND
110
910J.
NA
notes
J
ND
NA
Background well used for comparison to downgradient wells
Concentration given in the table is the average of two duplicate
samples
indicates an*estimated value
indicates none detected
not analyzed
-24-
-------
5.2.4 Surface Water Contamination
Surface water and stream sediments were sampled during the RI, to
determine both the nature of contamination of the streams in the
Study Area and to evaluate the migration of contaminants downstream
from the Study Area and the Smith's Farm site. This part of the RI
included sampling several seeps in the Study Area, as well as the
streams draining the Study Area. Sample locations in and around the
Study Area are shown in Figure 5. Sampling procedures are described
in the R*I report.
Surface water samples were collected in December 1987 during a
preliminary survey of the site. In April 1988, surface water samples
were collected at additional locations in and around the Study Area.
A few of the sample stations were resampled in December 1988 for
volatile and extractable organic compounds.
5.2.4.1 Organic Contamination
None of the background surface water samples from the December 1987
and April 1988 sampling events contained organic compounds. The
December 1988 sample from sample point SW-26, which is just upstream
of the road to the Smith's Farm site, contained low levels of two
volatile organic compounds and an unidentified extractable organic
compound. None of the other locations identified as background were
resampled in December 1988.
Several of the surface water samples collected downslope from the
Study Area contained organic compounds. The concentrations of the
organic compounds in these surface water samples were generally on
the order of a few micrograms per liter, although one soep
discharging from the east side of Area A contained a total volatile
organic concentration (mostly methyl isobutyl ketone) orl over 36,000
ug/1 in December 1987 and the total concentration of thirteen
volatile organics in a ponded area on the south side of Area A
exceeded 6,000 ug/1 in April 1988. Kentucky's warmwatei* aquatic
protection criteria for PCBs (401 KAR 5:031 Section 4) were exceeded
in samples collected from several seeps or other ground- water
discharge areas downslope from the drum disposal areas. Organic
contaminants were detected in both the East and West Creeks at the
margin of the Study Area. Samples collected downstream from the
confluence of these streams with the Unnamed Tributary contained
either relatively low concentrations of organic compounds or
contained non-detectable levels of organic compounds. Only two Study
Area stream sample locations were resampled in December 1988. The
sample from location SW-17 contained no organic compounds in December
1988, while the sample from location SW-18 contained an estimated
concentration of 2 ug/1 of chloromethane. A summary of organic
compounds detected in surface water samples collecttd in December
1987 and April 1988 is presented in Table 8.
-25-
-------
~ \-^
SCALE
0* 2001 400'
F1GURS
5
Source: RI Report
SMITH'S FARM
SURFACE WATER SAMPLE LOCATIONS IN THE
VICINITY OF THE STUDY AREA
-------
5.2.4.2 Inorganic Contamination
Inorganic contaminants were also detected in some of the surface
water samples collected in December 1987 and April 1988 (only organic
compounds were monitored in December 1988). Table 9 presents a
summary comparison of background surface-water concentrations of
inorganic parameters to the concentrations found in Study Area stream
samples. Concentrations of aluminum, antimony, arsenic, barium,
beryllium, cadmium, calcium, chromium, cobalt, copper, iron,
magnesium, manganese, mercury, nickel, potassium, silver, sodium,
vanadium, zinc, and cyanide exceeded the maximum detected background
concentration at one or more surface-water sample locations in the
Study Area. Particularly high levels of inorganic substances were
detected in some of the leachate seeps or ground-water discharge
areas downslope from drum disposal areas. Kentucky's warmwater
aquatic protection criteria for cadmium, cyanide, mercury and zinc
(401 KAR 5:031, Section 4) were exceeded in one or more of the
samples collected from the seeps or ground-water discharge areas.
Sample SW-18, which was collected from the Unnamed Tributary at the
downstream part of the Study Area, contained levels of inorganics
consistent with background concentrations, except for a slightly \
higher sodium concentration than background.
5.2.4.3 Surface Water Contamination Summary
In summary, the surface waters in the Study Area show evidence of
contamination by both organic and inorganic contaminants. The worst
contamination was found in leachate seeps or other ground-water
discharge areas downslope from drum disposal areas. The streams in
the Study Area had fairly low or insignificant levels of
contaminants. The water qual.ity at sample location SW-18, which is
located at the downstream end of the Study Area, was generally
consistent with background concentrations of inorganic and organic
compounds; however, only a limited number of samples were collected
at this location.
5.2.5 Stream Sediment Contamination
Stream sediments were collected from the same Study Area locations as
the surface water samples (sc*e Figure 5). A few additional samples
were collected downstream of the Study Area, to determine if
contaminated sediments from the Study Area were migrating
downstream. Sediment sampling procedures are described in the RI
report. The sediment samples were tested for both organic and
inorganic substances.
5.2.5.1 Organic Contamination
Background concentrations of organic compounds were below detectable
levels, with the exception of chloroform, which was detected in
several background samplers (an average concentration of 1.4
mi'crograms per kilogram (ug/kg), and di-n-octyl phthalate, which was
-27-
-------
TABLE 8 y
SURFACE WATER CONTAMINATION by ORGANIC COMPOUNDS
DECEMBER 1987 and APRIL 1988
SMITH'S FARM SITE
Sample Location and Concentration (ug/1)
"" SW-07 SW-08 SW-09 SW-14
ND ND ND ND
31 ND ND 46
3J ND ND 30
Contaminant
Acetone
1,2 Dichloroethene
Trichloroethene
Methyl Isobutyl
Ketone
Toluene
Chlorobenzene
Ethyl Benzene
Total Xylenes
Isophorone
Benzole Acid
Naphthalene
2 Methylnaphthalene
Acenaphthene
Fluoranthene
PCB-1242
PCB-1254
PCB-1260
SW-05
8100N
850J
ND
30QOOJ
ND
ND
ND
5200
71
ND
440
61 -
40
ND
5.5J
10J
15 J
SW-06
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
25J
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
notes t
ND
ND
ND
ND
ND
ND
13J
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
2J
ND
ND
ND
16
8
U
42
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
SW-16
ND
11
10
ND
ND
ND
ND \
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
J indicates an estimated value
N indicates presumptive evidence of material
The concentration for sample SW-06 is an average of two
duplicate samples
ND indicates none detected
Table 8 is continued on the following pace
-28-
-------
Table 8 continued
Contaminant
Vinyl Chloride
Chioroethane
1,1 Dichloroethene
1,1 Dichloroethane
1,2 Dichloroethene
Methyl Ethyl
Ketone
1,1,1 Trichloro-
ethane
Benzene
Methyl Isobutyl
Ketone
Tetrachloroethene
Toluene
Ethyl Benzene
Total Xylenes
Phenol
Benzyl Alcohol
2 Methyl Phenol
3 and/or 4 Methyl
Phenol
Isophorone
2,4-Dimethylphenol
Benzoic Acid
Naphthalene
PCB-1260
Sample Location and Concentration (ug/1)
SW-17 SW-29 '' SW-3Q SW-31 SW-32 SW-33
ND
NO
ND
ND
U
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
27
ND
ND
ND
ND
ND
1.5J
ND
ND
ND
ND
ND
3J
: ND
"ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
notes:
ND
3J
ND
9
4J
26J
5J
3J
43
96
12J
87J
15J
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
48
ND
3J
3J
790
580J
22
1J
58J
2J
420J
28J
170J
ND
9J
110
ND
ND
1.5J
ND
26
ND
ND
ND
1500
14
980
310
1700
8J
ND
13J
14J
12J
6J
91J
8J
2.7
J indicates an estimated value
The concentration for samples SW-29 and SW-32 is the
average of two duplicate samples
ND indicates none detected
-29-
-------
TABLE 9
SURFACE WATER CONTAMINATION BY INORGANIC SUBSTANCES
I DECEMBER 1987 AND APRIL 1988
SMITH'S FARM SITE
Contaminant
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Thallium
Vanadium
Zinc
Cyanide
Background (n=5)
Concentrat ion
Range
ND-350
ND
ND
ND
ND
ND
6200J-
16000J
ND
ND
ND
ND-700J
ND
4700-
7400
ND-44
ND
ND
ND-2400
ND
ND
ND
ND
ND
ND
ND
Median
ND
ND
ND
ND
ND
ND
10000J
ND
ND
ND
ND
ND
5800
ND
ND
ND
1800
ND
ND
ND
ND
ND
ND
ND
notes
Study Area (n=17)
Concentration
Range
ND-37000
ND-160JN
ND-15J
ND-1500
ND~2
ND-52JN
Median
420
ND
ND
ND
ND
ND
ND-110000 9600
ND-95J ND
ND-100 ND
ND-140 ND
ND-330000 3200
ND ND
ND-45000 6700
ND-7500 43
ND-0.92JN ND
ND-16 ND
ND-40000 2600
ND ND
ND-13 ND
ND-170000 9400
ND ND
ND-130 ND
ND-930 ND
ND-20J ND
J indicates an estimated value
N presumptive evidence of presence of material
ND indicates none detected
n is the number of samples
-30-
-------
found at a concentration of 150 ug/kg in one background sample. The
low levels of chloroform detected may be the result of laboratory
contamination; an upslope residential area is a potential source of
the phthalate compound that was detected.
Generally, organic compounds, if present in Study Area sediment
samples, were low solubility extractable compounds rather than the
volatile organics. PCBs were found in several.Study Area sediment
samples. Several Study Area surface-water sample locations showed
low or insignificant levels of organic compounds, yet the sediment
samples collected from these areas contained relatively high levels
of organics. Either the transport of organic compounds bound to
sediments into the streams around the Study Area has occurred, or
less soluble aqueous phase organics are bound to sediments soon after
entering the streams, or both. Contaminated sediments may then be
washed downstream. Table 10 summarizes the organic contaminants
found in Study Area sediments. The background concentrations .of all
organic compounds in sediments are presumed to be below detection
limits. Table 11 compares Study Area to downstream concentrations of
organic compounds in sediments.
5.2.5.2 Inorganic Contamination
Some inorganic parameters were found in Study Area sediments at
concentrations above background values. Overall, however, sediment
contamination by inorganics is relatively minor. Table 12 summarizes'
the sediment contamination by inorganic substances. Median
concentrations of all the inorganics are virtually equivalent between
background and Study Area samples. However, several of the
inorganics, most notably barium, cadmium, chromium, and lead,
exceeded background levels in one or more sediment samples from the
Study Area. Table 13 compares Study Area to downstream
concentrations of inorganic substances.
5.2.6 Summary of the Study Area Contamination
Contamination of surface and subsurface soil, ground water, surface
water, arid stream sediments was found in the Study Area at Smith's
Farm. Contaminants found in soil include volatile organic compounds,
extractable organic compounds, metals, and cyanide. Organic
compounds were found in both surface and subsurface soils, while soil
contamination by*inorganic parameters was restricted to surface
soils. Shallow ground water is primarily contaminated with volatile
organic compounds. A few shallow ground-water samples contained
extractable organic compounds, and two ground water samples showed
contamination with metals. Surface waters in the Study Area are
contaminated with volatile organic compounds, extractable compounds,
metals, and cyanide. Surface-water contamination was most ~
significant in seeps or other ground-water discharge areas just
downs lope from-drum disposal locations in the Study Area.
Surface-water samples collected in the downstream part of the Study
-31-
-------
TABLE 10
SEDIMENT CONTAMINATION BY ORGANIC COMPOUNDS
SMITH'S FARM SITE- STUDY AREA
Contaminant
1,1 Dichloroethane
1,2 Dichloroethene
1,1 Dichloroethene
Chloroform
Trichloroethene
Toluene
Total Xylenes
Vinyl Chloride
Chloroethane
Acetone
Methyl Ethyl Ketone
1,1,1 Trichloroethane
1,1,2 Trichloroethane
Benzene
Methyl Isobutyl Ketone
Methyl Butyl Ketone
Tetrachloroethene
Chlorobenzene
Ethyl Benzene
2 Methyl Phenol
3 and/or 4 Methyl
Phenol
Isophorone
2 -Dimethyl Phenol
Di-N Butyl Phthalate
Benzyl Butyl Phthalate
Number of
Detections /Number
of Samples
2/17
4/17
1/17
11/17
5/17
4/17
3/17
1/17
1/17
1/17
1/17
1/17
1/17
2/17
1/17
1/17
1/17
1/17
2/17
1/17
1/17
1/17
1/17
1/17
4/17
6. Mean
Cone .
4
5.5
4
2
5.9
6.3
10.4
9.5
8.4
22
na
4.2
4
4
11
7.8
4.5
1.6
6.9
57
229
133
34
4166
514
Maximum Cone./
Sample Location
12J/SD-33
1500/SD-33
7J/SD-33 .
3.5/SD-29
570J/SD-33
2400/SD-33
25000/SD-33
110/SD-33
13J/SD-31
1200J/SD-33
1400J/SD-33
20/SD-33
5J/SD-33
8J/SD-31
1800J/SD-33
8J/SD-33
39/SD-33
3J/SD-31
3100/SD-33
110J/SD-33
-
440J/SD-33
255/SD-29
PJ/SD-33
8000J/SD-33
2200/SD-31
notes
all concentrations in ug/kg
* Average of two duplicate samples
na not applicable
J indicates an estimated value ' " ' .
N presumptive evidence of presence of material
Geometric Mean (G.Mean) calculated by using either 1/2 the detection
limit, or 1/2 the the lowest estimated concentration, if below the
detection limit, for all non-detect samples
table 10 continued on the following page
-32-
-------
table 10 continued
Bis 2 Ethyl Hexyl
Phthalate
Benzo B/K Fluoranthene
Benzo-A-Pyrene
Dibenzo(A,H)Anthracene
Benzo(GHI)Perylene
PCB 1248
PCB 1254
PCB 1260
Benzoic Acid
Naphthalene
2-Methylnaphthalene
Pyrene
Benzo(A)Anthracene
Number of
Detection/Number G.Mean
of Samples
4/17 1610
1/17 524
1/17 523
1/17 524
1/17 524
1/17 122
1/17 173
9/17 363
1/17 46
2/17 448
2/17 71
1/17 575
1/17 552
notes
Max. Cone./
?catior
69000JN/SD-07
34000J/SD-06
21000J/SD-06
29000J/SD-06
36000J/SD-06
2000J/SD-14
2350J/SD-06
2200/SD-33
88J-SD-29
940/SD-31
150J/SD-31
2100/SD-31
1100/SD-31
all concentrations in ug/kg
J indicates an estimated value
N indicates presumptive evidence of the presence of material
Geometric mean (G. Mean) calculated by using either 1/2 the detectioi
limit or 1/2 the lowest estimated concentration, if below the
detection Imit, for all non-detect samples
-33-
-------
TABLE 11
COMPARISON OF STUDY AREA TO DOWNSTREAM
SEDIMENT CONTAMINATION BY ORGANIC COMPOUNDS
SMITH'S FARM SITE
Contaminant
Study Area
Concentrations
G. Mean Maximum
Downstream
Concentrations
G. Mean Maximum
1,1 Dichloroethane
1,2 Dichloroethene
1,1 Dichloroethene
Chloroform
Trichloroethene
Toluene
Total Xylenes
Vinyl Chloride
Chloroe thane
Acetone
Methyl Ethyl Ketone
1 , 1,1 Trichloroethane
1,1,2 Trichloroethane
Benzene
Methyl Isobutyl Ketone
Methyl Butyl Ketone
Tetrachloroethene
Chlorobenzene
Ethyl Benzene
2 Methyl Phenol
3 and/or 4 Methyl
Phenol
Isophorone
2 -Dimethyl Phenol -
Di-N Butyl Phthalate s -
Benzyl Butyl Phthalate
Bis 2 Ethyl Hexyl .,
Phthalate
Benzo B/K Fluoranthene
4
5 .5
4
2
5 . 9
6.3
10.4
9.5
8.4
22
na
4.2
4
4
11
7.8
4.5
1.6
6.9
57
229
133 ft
34 -*
4166
514
1610
524
12J
1500
7J
3.5
570J
2400
25000
110
13J
1200J
1400J
20
5J
8J
1800J
8J
39
3J
3100
110J
440J
255
66J
8000J
2200
69000JN
34000J
3.6
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
3.7
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
.ND
;
ND
770
6
7
;
3900
notes
all concentrations in ug/kg
* Average of two duplicate samples
na not applicable .
J indicates an estimated value ':
N presumptive evidence of presence of material
ND indicates none detected
Geometric mean (G. Mean) calculated by either using 1/2 the detection
limit or 1/2 the minimum estimated value, if less than the detection
limit for all non-detect samples \
table continued on the following page
-34-
-------
table 11 continued
Contaminant
Study Area
Concentrations
G. Mean Maximum
Downstream
Concentrations
G. Mean Maximum
Benzo-A- Pyrene .
Olbenzo ( A, H ) Anthracene
Benzo ( GHI ) Perylene
PCB 1248
PCS 1254
PCB 1260
Indeno (1,2,3 -CD ) Pyrene
Benzole Acid
Naphthalene
2 Methylnaphthalene
Dlbenzofuran
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo (A) Anthracene
Chrysene
523
524
524
122
173
363
ND
46
448
71
ND
ND
ND
ND
ND
575
552
ND
21000J
29 000 J
36000J
2000J
2350J
2200
88
940
150
2400
1100
430
380
480
ND
ND
ND
460
ND
258
50
320
330
660
420
820
780
450
520
1900
650
1600
1300
350
160
6600
610
7100
1600
7100
5900
2400
3600
notes
all concentrations in ug/kg
J Indicates an estimated value
ND none detected
Geometric mean (G. Mean calculated using either 1/2 the detection
limit or 1/2 the minimum estimated value, If below the detection
limit, for all non-detAt samples
-35-
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TABLE 12
SEDIMENT CONTAMINATION BY INORGANIC SUBSTANCES
SMITH'S FARM SITE
Contaminant
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Thallium
Vanadium
Zinc
Cyanide
Background ( n-
Concentration
Range
9300J-12000J
ND-3 . 5 J
ND-18JN
54J-78J
ND
ND
ND-6100J
15J-19J
ND-21
ND
24000J-52000J
14J-16J
2400J-6200
440J-1000J
ND
21-29
1500J-2100J
ND
ND-1.5J
ND
ND
21-26
61J-110J
ND
5)
(ug/kg)
Median
11000J
ND
12JN
69J
ND
ND
1200J
17J
17
ND
28000J
14J
3000J
620J
ND
25
1900J
ND
ND
ND
ND
.23
85J
ND
Study Area (n=»19)
Concentration (ug/kg)
Rancre Median
7400J-16500J"
ND
ND-56
47-2300J
ND
ND-6 . 3 JN
ND-23000J
12J-120J
ND-28
ND-21
18000J-110000J
ND-990J
1800-15000J
140J-1600J
ND
ND-57
730J-3150J
ND
ND-1.4J
ND-730
ND
ND-39
72J-380J
ND
11000J
ND
8.2
95J
ND
ND
1200J
20J
17J
ND
31000J
19 J \
3300J
460J
ND
19
1700J
ND
ND
ND
ND
25
105J
ND
notes
*Indicates an average for a duplicate sample location
ND incates not detected
J indicates an estimated value
n is the number of samples
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TABLE 13
COMPARISON OF STUDY AREA TO DOWNSTREAM
SEDIMENT CONTAMINATION by INORGANIC SUBSTANCES
SMITH'S FARM SITE
Contaminant
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Thallium
Vanadium
Zinc
Cyanide
Downstream
Concentration
Ranoe
7700J-15000J
ND
5.7JN-45JN
ND-120J
ND
ND-5 . 3 JN
1800-15000J
18J-33J
15-30
ND-14
31000J-97000
ND-110J
3000-11000J
250J-1500J
"ND
ND-110
1300J-4500J
ND
ND-1.6J
ND-190
ND
24-45
92J-260J
ND
(ug/kg)
Median
13000J
ND
17JN
80J
ND
ND
UOOJ
23J
21
ND
69000J
26 J
5400J
710J
ND
57
2300J
ND
ND
ND
ND
27
170J
ND
Study Area
Concentration (ug/kg)
Rancre Median
7400J-16500J"
ND
ND-5 6
47-2300J
ND
ND-6 . 3 JN
ND-23000J
12J-120J
ND-28
ND-21
18000J-110000J
ND-990J
1800-15000J
140J-1600J
ND
ND-57
730J-3150J
ND
ND-1.4J
ND-730
ND
ND-39
72J-380J
ND
11000J
ND ND
8.2
95J
ND
ND
1200J
20J
17J
ND .
31000J
19J
3300J
460J
ND
19
1700J
ND
ND
ND
ND
25 .
105J
ND
notes
*Indicates an average for a duplicate sample location
ND incates not detected
J indicates an estimated value
N indicates presumptive evidence of the presence of material
-37-
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Area indicate that the surface-water contamination there does not
represent a significant pathway; however, only a limited number of
samples have been collected to support this conclusion. Stream
sediments are primarily contaminated by organic compounds. The
highest levels of sediment contamination are found in areas of
ground-water discharge immediately downslope from drum disposal
areas. Contaminated sediments may be washed downstream, especially
during periods of heavy runoff.
The vertical extent of ground-water contamination was not determined
in the first operable unit Remedial Investigation. The nature of
deeper ground- water contamination will be investigated in a second
operable unit RI/FS. In the interim, potential downgradient
ground-water receptors are being monitored quarterly. Contamination
emanating from the permitted landfill at Smith's Farm will also be
investigated in the second RI/FS; preliminary results indicate that
the landfill is the. source of some environmental contamination.
Other areas of suspected drum disposal will also be investigated in
the second RI/FS.
Three areas of suspected drum disposal were investigated in the RI.
Areas A and B (identified in the RI report) were found to be sources
of contamination and will be part of the planned remedial action for
the Study Area. Area C was not found to be a significant source of
contamination and no remedial activities will be required for that
part of the Study Area. . .
Several ground-water and surface-water standards are exceeded in some
sample locations in the Study Area. The chemicals .for which water
quality standards are exceeded are listed in Table 14 of this
document.
6.0 SUMMARY OF SITE RISKS
6.1 Introduction
As a part of the Remedial Investigation of the Smith's Farm site, an
Endangerment Assessment (EA) was performed in order to evaluate the
potential human health and environmental impacts and risks associated
with the Smith's Farm site. The EA' documented the potential and
probable risks to human health and the environment that would occur
if no action was. taken to remediate the contamination in the Study
Area.
The EA included the following informationt
0 Identification of chemicals of potential concern- the chemical
toxicity and chemical distribution in the environment
° The exposure pathways from each of the contaminated
environmental media
0 The human health risks posed by the chemicals
0 The risks to the environment .posed by the chemicals
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TABLE 14
SUBSTANCES EXCEEDING WATER-QUALITY CRITERIA
IN THE STUDY AREA
Media of Concern and Potential ARAR Exceeded
Substance of Ground Water Surface Water
Concern
Vinyl Chloride MCL"1" MCL
Acetone . FCC*
Trichloroethene MCL MCL
Benzene MCL
Cresols ~ FCC,WAHC
Polychlorinated
Biphenyls (PCBs) FCCT,WAHC
Chromium MCL MCL
Lead MCL
Mercury FCC,WAHC
Zinc ' . FCC,WAHC
WATER-QUALITY ; +MCL- Maximum contaminant level. MCLs are
CRITERIA enforceable drinking water standards under the federal
Safe Drinking Water Act.
"FCC- Freshwater chronic criteria. These are water
quality criteria developed under the Clean Water
^ Act for the protection of aquatic life.
WAHC-Warmwater aquatic habitiat criteria for the
Commonwealth of Kentucky, included in Kentucky
Administrative Regulations, Title 401, Chapter
5:031.
indicates that criterion is either not applicable
or is not exceeded
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Risks posed by the chemicals in the Study Area were estimated for
both a "current use scenario" and a "future use scenario". The
"current use scenario* considered the exposures and risks that nearby
residents are subject to or could be subject to under present
conditions. The "future use scenario" considered the risks that
would be posed to future residents living both on and off site if no
remedial actions were taken and the site use was unrestricted.
EPA risk assessment guidance and generally accepted risk assessment
methods were used to estimate the risks posed by an "average
exposure" case and a "plausible maximum exposure" case. The EA used
generally conservative assumptions and methods to estimate the risks
posed by the site. Assumptions and methods used in the risk --
assessment are described in more detail in Section 6.2.
6.2 Assumptions and Methods of Analysis
6.2.1 Exposure
Assumptions were made about human exposure to contaminants in order
to calculate the risks posed by the current-use and future-use
scenarios. Under the current use-scenario, persons potentially ,
exposed to contaminants on site are hunters who may be exposed to
contaminated soils through direct contact or incidental soil
ingestion; hunters or other site trespassers or neighborhood children
who may be exposed by direct contact to contaminated surface water;
and trespassers who may be exposed to organics in the air, primarily
through volatization from surface waters on site. Dirt-bike riders
trespassing onto the site may be exposed to contaminated soils
through dust generation. Potential exposures to persons off site
under the current use scenario are limited to ground water exposure
(ingestion, dermal contact and inhalation of volatilized organics are
potential pathways) or to children who may wade in Blue Lick creek.
Under the future-use scenario, the site is assumed to potentially
have residents living on site. Under these conditions, young
children could absorb contaminants through the skin or ingest
contaminated soil through hand to mouth activity while playing on
site. Adults living on site could ingest incidental amounts of soil
after gardening or minor construction projects. Human exposure to
contaminated air< surface water and sediment is assumed to be the
same as for the current-use scenario. Exposure to contaminated
ground water could occur if on site residents install wells into the
shallow aquifer in the area.
For all environmental media (soil, air, surface water, etc.), two
exposure scenarios were calculated. One exposure scenario was the
average case, based upon geometric mean concentrations. A plausible
maximum exposure scenario was considered to be related to the maximum
contaminant concentration found on site. For the exposure to dust
generated by dirt bike riding, the average case assumed an exposure
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from one dirt bike riding through the site for one hour, while the
plausible maximum case assumed that three dirt bikes were riding
through the site for two hours.
In estimating exposure to site trespassers, it was assumed that the
site would be traversed once per week for forty weeks per year for
the average case and twice per week for 40 weeks per year for the
plausible maximum case. The total duration of exposure was assumed
to be 10 years and 55 years for the average and maximum plausible
cases respectively. . " .
Contact with surface water and sediments by children off site assumed
that children between the ages of 7 and 17 could be exposed by wading
in Blue Lick Creek. The period of exposure was assumed to be 5 years
for the average case and 10 years for the maximum plausible case. In
the average case, the exposure was estimated to be 40 times per year
while the exposure was estimated to be 80 times per year for the
maximum plausible case.
For future-use residents, it was assumed that exposure to on-site\
soils would occur for 10 years in the average case and for 55 years
in the maximum plauuible case. The frequency of exposure to soils
was considered to be a function of age.
If site conditions limit future-use development (for example, slope
stability might limit areas of the site where an individual might
build a house), only the chemical concentrations within the area
where development might occur were considered in the risk assessment.
Rates for soil ingest ion; soil bioavailability (percentage of
ingested soil actually absorbed); dermal absorption from soils,
sediments, and contaminated water; and inhalation of volatile
organics from contaminated water were determined from references.
Dermal absorption was assumed to occur for organic compounds only,
based upon the literature review. Ingestion exposure for
contaminated ground water was estimated based on the EPA standard
assumption of the intake of 2 liters of water per day by a 70-
kilogram individual.
Volatization of organic compounds from surface water into the air was
estimated using "a model. The flux rate from water to air was
determined by multiplying the mass transfer coefficient for a
chemical by the concentration of that chemical in the water. The
flux rate was then multiplied by the area of surface water to get a
contaminant emission rate. The surface water area was conservatively
estimated to be 2,450 m2 based on the location of samples that were-
collected.
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6.2.2 Chemicals
Several assumptions were made when considering the chemical data
generated in the RI that would be used in the risk assessment:
° Certain chemicals are frequently laboratory contaminants and
are often detected in "blank" samples used for environmental
quality control purposes. For these common contaminants,
concentrations in on-site samples that were less than 10
times the concentrations in an associated field or trip
blank were considered non-detects for purposes of the risk
assessment. For other contaminants, concentrations less
than 5 times the concentrations detected in associated field
or trip blanks were considered non-detects.
0 Estimated concentrations ("J" or "N"-flagged values) were
treated as actual concentrations for the risk assessment.
"R"-flagged data (indicating quality control problems) were
not used.
° Geometric mean values were estimated for media in which a
chemical was detected in one or more samples by considering
non-detect concentrations equal to one-half the sample-
specific detection limit.
° Concentrations for duplicate samples were calculated as the
geometric mean of the two measurements.
0 Inorganic background data used for comparisons to on-site
soil concentrations are 'site-specific, unless sufficient
data for statistical comparisons were unavailable. In such
cases, background data for soils were taken from published
U.S. Geological Survey values. .
° Chemicals with a frequency of detection less than 5% were
not considered in the risk assessment.
° Only chemicals with human health toxicity values were
included in the quantitative evaluations of human-health
impacts.
6.2.3 Risks
To determine the risks to human health> a non-threshold carcinogen
model was used. This model assumes that there is no threshold value
below which a carcinogen has no potential for carcinogenicity. For
non-carcinogens, it was assumed that there is a threshold below which
no human health effects would occur.
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To assess the risks to human health and the environment posed by the
site/ the concentrations of chemicals in relevant environmental
at points of potential exposure were converted to chronic daily
intakes (GDIs). GDIs are expressed as the amount of substance taken
into the body per unit body weight per unit time (mg/kg/day) . The
GDIs were averaged over a lifetime for carcinogens and over the
exposure period for non-carcinogens, in accordance with EPA
guidance
To evaluate risks to human health from carcinogens, the risk
assessment considered the cancer potency factors for the known or
suspected carcinogenic chemicals found in the Study Area. Cancer
potency factors (CPFs) have been developed by EPA's Carcinogenic
Assessment Group for estimating the excess lifetime cancer risk
associated with exposure to known or potentially carcinogenic
chemicals. CPFs, which are expressed in units of (mg/kg-day)~1 are
multiplied by the estimated intake of a potential carcinogen in
mg/kg-day to provide an upper-bound estimate of the excess lifetime
cancer risk associated with exposure at that intake level. The term
"upper bound" reflects the conservative estimate of the risks
calculated from the CPF. Use of this approach makes underestimation
of the actual cancer risk highly unlikely. Cancer potency factors
are derived from the results of human epidimiological studies or
chronic animal bioassays to which animal-to-human extrapolation and
uncertainty factors have been applied.
To evaluate the risks from non-carcinogens, the risk assessment
considered the reference doses for non-carcinogenic chemicals found
in the Study Area. Reference doses (RfDs) have been developed by EPA
for indicating the potential for adverse health effects from exposure
to chemicals exhibiting noncarcinogenic effects. RfDs, which are
expressed in units of mg/kg-day, are estimates of lifetime daily
exposure levels for humans, including sensitive individuals, that are
unlikely to be without an appreciable risk of adverse health
effects. Estimated intakes of chemicals from environmental media
(e.g., the amount of a chemical ingested from contaminated drinking
water) can be compared to the RfD. RfDs are derived from human
epidimiological studies or animal studies to which uncertainty
factors have been applied (e.g., to account for the use of animal
data to predict effects on humans). These uncertainty factors help
ensure that the RfDs will not underestimate the potential for adverse
noncarcinogenic effects to occur.
Potential risks for non-carcinogens were determined by calculating
the ratio of the GDI to the reference dose (CDI:RfD). THe sum of all
of the ratios of chemicals under consideration is called the hazard
index. A hazard index of less than one is assumed to not be
associated with any significant health risks, although the degree of
uncertainty involved in risk and intake calculations leaves some
doubt as to what is actually a "safe" hazard index.
-43-
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In accordance with EPA's guidelines for evaluating the toxicity of
complex mixtures, toxic effects of chemicals were assumed to be
additive. Therefore, lifetime excess cancer risks and the CDI:RfD
ratios were-summed to indicate potential risks associated with
mixtures of carcinogens and non-carcinogens respectively.
6.3 Contaminants Considered in the Risk Analysis
6.3.1 Surface Soils
Eighteen organic and twenty inorganic contaminants were detected in
the surface soil samples collected in the Study Area. Dimethyl
phthalate was detected in only one sample and was not detected in any
other medium and was eliminated as a chemical of potential concern.
Di-n-octylphthalate was also not considered as a chemical of
potential concern. The remaining organic chemicals were considered
of potential; concern and were retained in the risk assessment. The
organic chemicals of concern and their concentrations are presented
in Table 1 oi the ROD.
Lead was considered to be a potential concern based on a statistical
comparison ofC on site to background soil concentrations. Mercury was
considered to be a potential concern based on a comparison of on site
concentrations to published U.S. Geological Survey background soil
concentrations. No other inorganics were considered of potential
concern. Lead and mercury concentrations are presented'in Table 2 of
the ROD. ::
6.3.2 Subsurface Soils
In the Study Area, twenty two organic and eighteen inorganic
chemicals weredetected in subsurface soil samples. Of the organic
contaminants, 1,1,2-trichloroethane and pentachlorophenol were
eliminated as potential chemicals of concern based on their low;
frequency of detection. The remaining organica were retained in the
.risk analysis. These contaminants and their concentrations are
presented in.liable 3 of the ROD.
. - -if : -
Fourteen of the eighteen inorganics were detected in background
samples. Although as noted in Section 5.2.2, inorganic contamination
of subsurface soils did not appear to be significant considering the
raw data, statistical data analysis indicated that arsenic, barium,
chromium, cobalt,, iron, lead, magnesium, manganese, nickel,
potassium, vanadium and zinc exceeded background levels. Calcium
exceeded published background values. These inorganics are
considered in the risk analysis. A summary of the inorganic
substances detected in the Study Area subsurface soils is presented
in Table 4.
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6.3,3 Surface Water
Table 8 lists the concentrations of the organic chemicals found in
surface waters in the Study Area and Table 9 summarizes the
concentrations of the inorganic substances found in the Study Area
and compares those values to background levels.
In addition to samples collected in the Study Area, samples were
collected downstream from the Study Area in locations where either
the unpermitted drum disposal locations or the permitted landfill may
be the source of contaminants found in the streams. No organic
chemicals were detected in the samples collected in these downstream
areas. Any inorganic contaminants found in the downstream areas may
be derived from either the permitted landfill or the drum disposal
locations.
For the Risk Assessment, chloroethane, 1,1-dichloroethene, methyl
butyl ketone, chlorobenzene, phenol, benzyl alcohol, and
di-n^octylphthalate were eliminated as potential chemicals of concern
based: upon a low frequency of detection. The other organics detected
in surface water were retained for the risk assessment. Statistical
analysis indicated that aluminum, iron, manganese, and potassium in
the Study Area exceeded background levels. Calcium, magnesium and
potassium in samples collected downstream from the Study Area
exceeded background levels. Many inorganic substances found in
surface water were compared to background ground water concentration
because they were not found in background surface water samples.
From this comparison, antimony, barium, cadmium, chromium, cobalt,
lead, mercury, silver, vanadium, zinc, and cyanide were retained as
chemicals of potential concern.
6.3.4 v . Streazr Sediments .
Table 10 lists the organic substances found in stream sediments in
the Study Area. Organic substances were also found in several
sediment samples collected downstream from the Study Area. The
source..of chlorinated aliphatic compounds, ketohes, and monocyclic
aromatic compounds found in these downstream sediments may either be
the unpermitted drum disposal areas or the permitted landfill.
Polycyclie aromatic.compounds found in the downstream samples are
attributed to the permitted landfill in the Endangerment Assessment
Report; however, some of these compounds are found in a few of the
Study Area sediment samples. Phthalates and PCBs found in downstream
sediment samples are attributed to the unpermitted disposal areas. A
summary of the downstream sediment sample organic concentrations and
a comparison, of those concentrations to the Study Area concentrations
is presented in Table 11.
Inorganic substances detected in Study Area sediments are summarized
in Table 12. In addition to the inorganic substances found'in the
Study Area, several inorganic substances attributable to either
-45- .
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contamination from the unpermitted drum disposal areas or the
permitted landfill were found in sediment samples collected
downstream from the Study Area. A summary of the inorganic
substances found in samples collected downstream from the Study Area
and a comparison of those concentrations to Study Area concentrations
is presented in Table 13. Statistical analysis of the inorganic data
for sediments indicated that chromium and zinc exceeded background
levels in the Study Area sediments. Based on a comparison of
inorganic concentrations in sediment to published background values,
barium and lead exceeded background in the Study Area sediments and
calcium, cobalt, iron, magnesium, nickel, and vanadium exceeded
background in sediment samples collected downstream from the Study
Area. Other inorganic substances were not considered in the risk
assessment.
6.3.5 Ground Water
Tables 5 and 6 list the organic compounds detected in ground-water
samples from Study Area monitoring wells. Several of these compounds
have maximum contaminant levels (drinking water standards) that are
ARARs; other organic compounds are of potential concern from a health
effects perspective and are also included in the risk assessment.
Carbon disulfide, 1,1 dichloroethene, chloroethane, toluene and
bromochloroethane were not considered in the risk analysis.
The inorganic chemicals of potential concern that were detected in
the ground-water samples from the Study Area monitoring wells are
summarized in Table 7. Statistical analysis could not be used to
evaluate differences between background and Study Area wells because
of the small background sample size. Inorganics in Study Area
samples were considered to be above background and of potential
concern if they exceeded background by at least a factor of 2. Using
this criterion, the inorganics of concern that were considered in the
Risk Assessment include calcium, chromium, cobalt, iron, lead,
manganese, nickel, potassium, and zinc. Of these inorganics,
calcium, cobalt, iron and potassium do not have any toxicity criteria
established by EPA and were therefore only qualitatively considered
in the risk assessment.
6.4 Toxicitv Assessment Information
As described in "Section 6.2.3, the risk assessment considered the
reference doses (RfDs) in assessing the health risks posed by
non-carcinogens and the cancer potency factors (CPFs) .when evaluating
the risks posed by known or probable carcinogens. The oral and
inhalation RfOs and CPFs are compiled in the Endangerment Assessment
Report and are presented in Table 15.
Many of the CPFs are derived from animal studies, where animals are
subjected to high doses of chemicals. Since- humans are expected to
-46-
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TABLE 15
SUMMARY OF HEALTH EFFECTS CRITERIA
FOR CHEMICALS OF POTENTIAL CONCERN^
Chemical
Vinyl Chloride
Acetone
1,1-Dichloroethane
1,2-Dichloroethene
Methyl Ethyl Ketone
1,1,1 Trieloroethane
Trichloroethene
Benzene
Methyl Isobutyl Ketone
Tetrachloroethene
Toluene
Ethyl Benzene
Xylenes
Cresols++
Isophorone
Benzoic Acid
Nonearcinogenic PAHs*
Carcinogenic PAHs*
Di-n-Butylphthalate
Benzyl Butyl Phthalate
Bis (2-Ethylhexyl)
Phthalate
PCBs
Arsenic
Barium
Chromium VI
Chromium III
Lead
Manganese
Mercury
Nickel
Vanadium
Zinc
Oral Criteria
RfD CPF
mo/ko/d mg/ka/d"1
2.3
1E-1
Inhalation Criteria
RfD CPF
mq/kg/d mcr/kg/d"1
2.9E-1
2E-2
5E-2
9E-2
7.4E-3
5E-2
1E-2
3E-1
1E-1
2
5E-2
1.5E-1
4
4.1E-1
1E-1
2E-1
2E-2
9.1E-2
1.1E-2
2.9E-2
5.1E-2
9.6E-2
3E-1
4.6E-3
2.9E-2
2E-2
3.3E-3
1.2
6.1
7.7
1.8
5.1E-2
4. 8E-3 --
1
1.4E-4
2.2E-1
2E-3
2E-2
7E-3
2.1E-1
1E-4
3E-4
8.4E-1
7.7
50
4.1E-1
notes
+ Excludes inorganics without quantitative health effects criteria
(aluminum, calcium, cobalt, iron, magnesium, and potassium)
++ Cresols are the sum of 2-,3-,4-methyl phenol and 2,4-dimethyl
phenol
* None arc inogenic PAHs are the sum of acenaphthene, benzo(g,h,i)
perylene, fluoranthene, naphthalene, 2-methylnaphthalene, and
pyrene. Carcinogenic PAHs are the sum of benzo(a) anthracene,
benzo(a)pyrene, benzo (B/K)fluoranthene, and dibenzo(a,h)anthracene.
Indicates either not applicable or that no information was given
in the Endangermeht Assessment Report
-47-
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be exposed to lower doses than those used in animal studies, the data
are adjusted using mathematical models to get CPFs. Adjustments are
made to allow for a several-fold safety factor in determining the
CPF, to account for the uncertainty inherent in the conversion of
animal study data to human health risk estimation. Thus, the actual
risks associated with exposure to a potential carcinogen are unlikely
to exceed risks estimated by the CPF determined from animal data and
in fact, the risks may be much lower. CPFs based on human
epidemiological data are also derived using very conservative
assumptions and are unlikely to underestimate risks.
The Endangerment Assessment Report presents detailed discussions of
toxicological references concerning the chemicals of concern in the
Study Area.
6.5 Risk Characterization
Excess lifetime cancer risks are determined by multiplying the intake
level by the cancer potency factor. These risks are probabilities
that are generally expressed in scientific notation (e.g., 1x10~6
or 1E-6). An excess lifetime cancer risk of IxlO"6 indicates that,
as a plausible upper bound, an individual has a one in one million
chance of developing cancer as a result of site-related exposure to a
carcinogen over a 70-year lifetime under the specific exposure
conditions at a site. EPA has implemented actions under Superfund
associated with projected excess lifetime cancer risks ranging from
IxlO"4 (one in 10,000) to IxlO"7 (one in 10,000,000). A risk
level of IxlO**6 is often used as a benchmark risk level by EPA, and
the risk assessment followed this approach.
Potential concern for noncarcinogenic effects of a single contaminant
in a single medium is expressed as the hazard quotient (HQ), which is
the ratio of the estimated ^intake derived from the contaminant.
concentration in a given medium to the contaminant's reference dose.
By adding the HQs for all contaminants within a- medium or across all
media to which a given population may be reasonably exposed; the
Hazard Index (HI) can be generated. The HI provides a reference
point for determining the potential significance of multiple
contaminant exposures.
6.5.1 Current-Use Scenario Risks
6.5.1.1 Risks to Trespassers from Surface Soils
Table 16 summarizes the risks associated with surface soils. Total
excess lifetime cancer risks are estimated to be 3x10'° and
5x1O"4 for the average and plausible maximum exposure cases
respectively. The risk is essentially due to PCBs. The average case
is based on a geometric mean PCB concentration of 0.5 mg/kg, while
the plausible maximum case assumes a PCB concentration of 208 mg/kg.
The Hazard Index is less than 1 for the average case while in the
plausible maximum case, it exceeds 1 because of exposure to lead.
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6.5.1.2 Risks to Trespassers from Sediments
Table 16 summarizes the risks to trespassers from dermal contact with
stream sediments. The excess lifetime cancer risks in the average
exposure case and the plausible maximum exposure case are estimated
to be 2x10**' and 2x10""* respectively. The risks are associated
with carcinogenic PAHs and PCBs. The risk levels have incorporated
into the calculations the presence of contaminated sediments
downstream of the Study Area, some of which may be derived from the
permitted landfill. Hazard indices are less than one for both the
average and the plausible maximum exposure cases.
6.5.1.3 Risks to On-Site Trespassers from Contact with Surface Water
Table 16 summarizes the risks to on-site trespassers from dermal
contact with surface water. The excess lifetime cancer risks in the
average case and the plausible maximum cases are estimated to be
lxlO~c and 3xlO~5 respectively. The risks are primarily
associated with PCBs. Hazard indices are less than one for both
exposure cases.
6.5.1.4 Risks to Off-Site Residents from Contact with Surface Water
and Stream Sediments
Exposure is assumed to occur if children wade or play in or near Blue
Lick Creek. Excess lifetime cancer risks due to carcinogenic PAHs
are estimated to be 2xlO~7 and IxlO"5 under the average and
plausible maximum exposure cases respectively. Hazard indices are
less than one for both exposure scenarios. Since PAHs are associated
with the permitted landfill, some if not most of the risk from this
exposure is attributed to the landfill rather than to the Study Area.
6.5.1.5 Risks from Inhalation of Dust Generated by Dirt Bikes
The excess lifetime cancer risks to dirt bike riders are estimated to
be IxJO"1 and 4X10"11 under the average and the plausible
maximum cases respectively. Hazard indices are less than one for
both cases.
6.5.1.6 Risks to Trespassers from Inhalation of Volatile Organica
Released from Surface Water
Table 16 summarizes the risks to site trespassers associated with the
inhalation of organics released from surface water. Excess lifetime
cancer risks are 2x10" .and 6xlO"2 under the average and
plausible maximum cases respectively. The risk is attributable to
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TABLE 16
TOTAL CARCINOGENIC AND NONCARCINOGENIC RISKS OF CONCERN
FOR ALL EXPOSURE AND ENVIRONMENTAL MEDIA CONDITIONS-
CURRENT-USE SCENARIO
Environmental Medium,
Chemical, and Exposure
Conditions
1. Surface Soils Contacted
by Trespassers(mg/kg)
PCBs
Total cancer risk
Lead
Hazard Index
2. Stream Sediments
Contacted by Trespassers
(mg/kg)
Carcinogenic PAHs
PCBs
Total Cancer Risk
3. Surface Water Contacted
by Trespassers (mg/L)
PCBs
Total Cancer Risk
Concentration
Avg. Max.
Case Case
4.74E-1 2.08E+2
5.50E+1 8.90E+3
2.08 8.51E+1
7.24E-1 6.54
1.72E-2 3.35E-2
Risk or Hazard
Avg. Max.
Case Case
2.90E-8
3E-8
3.08E-2
3.08E-2
1.24E-7
3.49E-8
2E-7
1.39E-6
1E-6
4.54E-4
5E-4
1.99E+1
1.99E+1
2.24E-4
8.07E-6
2E-4
2.98E-5
4. Volatalized Organics
from Surface Water
Contacted by Trespassers
(mg/W3)
PCBs
Total Cancer Risk
Methy Ethyl Ketone
Methyl Isobutyl Ketone
Hazard Index
1.90E-1 3.90E-1
3.50
4.90
1.20E+2
7.30E+3
1.83E-3
3.20E-1
2.15
2^47
6.21E-2
6E-2
3.29E+1
9.60E+3
9.63E+3
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PCBs. Hazard indices are greater than one under both exposure cases
due to methyl ethyl ketone and methyl isobutyl ketone.
6.5.1.7 Risks from the Use of Residential Wells
Several residents living near the Smith's Farm site use well water.
The Endangerment Assessment Report describes the potential risks
associated with the use of the water from the individual wells that
were sampled. Substances of concern were essentially inorganics,
rather than organics associated with the landfill or Study Area.
Based upon the data available from the well sampling, there is no
evidence that any of the water samples have been impacted by
contamination from the Smith's Farm site. All of the inorganics
found in the wells may be naturally occurring, and there are several
possible sources of contamination in cases where well water samples
contain any organic compounds. Therefore, there is no reason to
conclude that the landfill or Study Area pose any risks to current
ground-water users near the Smith's Farm site.
6.5.2 Future-Use Scenario Risks
6.5.2.1 Risks from Direct Contact with Soils by On-Site Residents
This scenario assumes that a residence will be placed on site in an
area suitable for such land use. It is also assumed that subsurface
soils might be brought to the surface during construction activities
on site.
Table 17 summarizes the risks associated with these exposures. Only
data from soil samples collected in areas deemed potentially suitable
for locating a residence were considered in calculating these
numbers. Excess lifetime cancer risks due primarily to arsenic are
3xlO~6 and 4x10 under the .average and plausible maximum cases
rspectively. The hazard index is less than one for the average case
exposure, but exceeds one for the plausible maximum case exposure
because of potential contact with lead.
6.5.2.2 Risks from Use of On-Site Ground Water
The risks from the use of on-site ground water by future residents
are presented in Table 17. Only monitoring data from monitoring
wells located in the area of potential residential development were
considered in the risk analysis. Total excess lifetime cancer risks
were lxlO~3 and 2xlO~3 for the average and plausible maximum
cases respectively. Vinyl chloride and 1,1-dichloroethane are the
main contributors to this risk. Hazard indices exceed one due to
chromium, manganese, nickel, and lead.
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TABLE 17
TOTAL CARCINOGENIC AND NONCARCINOGENIC RISKS OF CONCERN
FOR ALL EXPOSURE AND ENVIRONMENTAL MEDIA CONDITIONS-
FUTURE -USE SCENARIO
Environmental Medium,
Chemical, and Exposure
Conditions
1. Soils Contacted by
On-Site Residents(mg/kg)
Arsenic
Total Cancer Risk
Lead
Hazard Index
2. Ground Water Contacted
by On-Site Residents (mg/L)
Vinyl Chloride
1,1-Dichloroethane
Trichloroethene
Benzene
Total Cancer Risk
Chromium
Manganese
Nickel
Lead
Hazard Index
Concentration
Avg. Max
Case Case
1.34E+1 3.00E+1
2.50E+1 9.30E+2
6.00E-3
5.00E-3
4.00E-3
2.00E-3
3.90E-2
1.01
1.65E-1
6.00E-3
l.OOE-2
2.70E-2
1.80E-2
2.00E-3
2.60E-1
1.60E+1
8.80E-1
1.80E-2
Risk or Hazard
Avg. Max
Case Case
2.59E-6
3E-6
1.68E-1
1.89E-1
1.31E.-3
4.31E-5
4.17E-6
5.49E-6
2.32E-1
1.32E-1
2.36E-1
1.22
3.19B-5
6.25
6.43
2.18E-3
2.33E-4
1.88E-5
5.49E-6
2E-3
i.55
2.08
1.26
3.67
9.18
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6.5.2.3 Risks to Off-Site Residents
The risks posed to future off-site residents from soils and ground
water were determined by considering data outside the Study Area.
Therefore, while providing some information on the risks posed by the
permitted landfill, these data are not relevant to the remediation of
the Study Area.
6.5.2.4 Other Future-Use Risks
As mentioned in Section 6.2.1, exposure to contaminated air, surface
water, and sediment was assumed to be the same for both the
current-use and future-use scenarios.
6.5.3 Qualitative Risks
In addition to quantifying the risks associated with exposure to some
of the chemicals found in environmental media at the Smith's Farm
site, the Endangerment Assessment Report presents a qualitative
analysis of the risks posed by several inorganic substances found in
the Study Area in concentrations above background levels.
Concentrations of iron in soils and ground water are expected to
contribute to risks under the exposure pathways considered in the
risk assessment, while aluminum, calcium, cobalt, magnesium, and
potassium are not expected to contribute to risks.
6.54 Summary of Human Health Risks
Tables 16 and 17 present the total carcinogenic and noncarcinogenic
(hazard index) risks determined by the quantitative risk analysis,
for all exposure and environmental media conditions. Individuals may
be exposed to more than one source of risk; for example, future-use
exposure to chemicals for a person living on site may be from both
contaminated ground water and soils. Combined exposures such as this
have an associated risk that is assumed to be the sum of the
individual risks. Tables 16 and 17 could thus be used to determine
the risk to an individual with more than one exposure pathway.
6.6 Environmental Risks
In addition to risks posed to human health by the Study Area, the
risks posed to terrestrial and aquatic life by the contamination in
the Study Area were estimated. This assessment was primarily based
upon information obtained from relevant literature. The assessment
identified potential receptors (animals and plants that could be
affected); identified the exposure routes and estimated the amount of
exposure to receptors; and used toxicity data and the exposure
information to estimate the risks to the receptors.
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6.6.1 Receptors
?i
Potential terrestrial receptors in the Study Area are the deciduous
plants found on site and the fauna that live in the forested areas in
and around the Study Area. There are few potential aquatic receptors
within the Study Area because of the intermittent stream flow.
Downstream aquatic receptors may be present in Blue Lick Creek?
although the stream probably supports a very limited, if any, fish
population. V
6.6.2 Exposure Routes ~
Exposures of terrestrial plants to chemicals from the Study Area may
occur through exposure to polluted air or to soil or water
contamination. Air and water exposure was not addressed in the
Endangerment Assessment Report, while the soil exposure route tsras
considered by a comparison of geometric mean surface soil y.
concentrations to concentrations of chemicals that may affect pJLant
life. - $!;
Terrestrial animals may be directly exposed to chemicals through
inhalation of contaminated air or ingestion of contaminated soil or
surface water. Although quantitative assessment of exposure through
these exposure routes could generally not be done due to limited
available information, possible exposures of animals to chemicals
from drinking water was roughly approximated by assuming daily
consumptions based on species type and animal size. For the
assessment, it was assumed that the surface water of the Smith's Farm
site was exclusively used as a drinking-water source by small mammals
and birds of the area. Indirect exposure of terrestrial animals,.to
contaminants through consumption of contaminated prey was not ,
considered in the assessment. .->.
Aquatic life could be directly exposed to chemicals from contaminated
surface water or stream sediments, and indirectly through consumption
of contaminated prey. In the Endangerment Assessment report, oriJ/y
the direct exposure pathways were assessed.
6.6.3 Toxicity Assessment '
Toxicity criteria for the protection of aquatic life have been
developed by both EPA and the Commonwealth of Kentucky for a limited
group of chemicals, and these criteria could be compared to
concentrations of those substances detected in streams at the Smith's
Farm site. In all other cases, toxicity values were derived from the
available literature. The toxicity values selected for the
assessment were the lowest exposure concentrations or doses reported
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to be toxic or the highest concentrations or doses associated with n<
adverse effect. When available, toxicity values were derived from
studies using species similar to the receptors that may be found at
the Smith's Farm site. For the risk assessment, toxic ity chronic
values that were not available in the literature were estimated, to be
equal to one-fifth the acute lethality values that werer available in
the literature. 5
Uncertainty factors were applied to the toxicity data. A safety
factor of 10 was applied to a lowest observed effects level (LOEL)
derived from a chronic toxicity study and a safety factor of 100 was
applied to a LOEL derived from subchronic or subacute studies. An
additional safety factor of 2 was applied for endangered species.
Information about toxicity to terrestrial plants was available for
only phthalate esters, PCBs, PAHs, and zinc, although there are many
more chemicals of possible concern that are present in surface
soils. Information about toxicity to terrestrial wildlife was
available for ingestion of water containing ethylbenzerie, PCBs,
arsenic, barium, chromium, copper, cyanide, iron, lead, And nickel.
A relatively large volume of material concerning toxicity of
chemicals to aquatic organisms is available in the literature.
Ambient water quality criteria developed by EPA are developed to
protect 95% of all aquatic species, and these criteria cover many of|
the chemicals of concern in surface waters at the site. Other
aquatic toxicity data were available for most of the chemicals found
in surface waters at the site.
Stream sediments provide habitats for many important aquatic species
and the possible impacts of sediment contamination on aquatic
organisms was therefore evaluated. Criteria for the protection of
aquatic life from contaminated sediments have not been established,
but an-EPA recommended approach using a surface water-sediment
partitioning method was followed to derive interim sediment quality
criteria. The criteria were calculated by multiplying ambient water
quality criteria by chemical-specific partitioning coefficients.
6.6.4 Risk Assessment Results
Based on a comparison of concentrations of chemicals of concern in
the soil of the Study Area to available literature information, there
may be some adverse effect to plants from the zinc and PCBu found at
some surface soil locations in the Study Area.
Effects to terrestrial organisms in the Study Area are not generally
expected from drinking surface water, although the concentrations of
PCBs detected at some locations exceed the chronic criterion set by
EPA to protect mink drinking from such waters and consuming fish.
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Therefore, it is possible that the concentrations of PCBs found in
surface waters of the Study Area have an adverse effect on mink or
similar species.
Several chronic aquatic toxicity criteria are exceeded in surface
water and assumed to be exceeded in stream sediments. Aquatic
toxicity criteria and the associated geometric mean and maximum
values found in samples from surface waters and sediments at the
Smith's Farm site are given in Tables 18a and 18b. The importance of
these values is somewhat diminished because the streams in the Study
Area may become dry during times of low rainfall.
7.0 DESCRIPTION OF REMEDIAL ACTION ALTERNATIVES
The Feasibilty Study report presents the results of a detailed
analysis conducted on five potential remedial action alternatives for
Areas A and B at the Smith's Farm site. This section of the Record
of Decision presents a summary of each of the five alternatives that
are described in the FS report. The five alternatives were evaluated
by EPA by considering the following nine criteria:
- Short-Term Effectiveness
- Long-Term Effectiveness and Permanence
- Reduction of Toxicity, Mobility, or Volume
- Implementability
- Cost
- Compliance with Applicable or Relevant and
Appropriate Requirements (ARARS)
- Overall Protection of Human Health and the Environment
- State Acceptance
- Community Acceptance
The alternatives and criteria used to consider the alternatives are
in accordance with the National Oil and Hazardous Substances
Pollution Contingency Plan 40 CFR Part 300, Subpart F, Section 300.68
and the Comprehensive Environmental Response, Compensation, and
Liability Act of 1980 (CERCLA) as amended by the Superfund Amendments
and Reauthorization Act (SARA), PL 99-499.
7.1 The "No Action" Alternative
The "No Action" (limited action) alternative is included for
comparison to the other four alternatives. The alternative includes
the installation of a- fence around the contaminated part of the Study
Area, placement of warning signs, and a long-term site monitoring
program. Future use of the site would also be restricted. In
addition, as required by law, a risk assessment would be performed
every five years. Construction time for this alternative would be
approximately three months.
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TABLE 18a
COMPARISON OP AQUATIC TOXICITY CRITERIA TO CONCENTRATIONS
OF CHEMICALS FOUND IN STREAMS AT SMITH'S FARM
Chemical
PCBs
Xylenes
Cadmium
Chromium VI
Cyanide
Iron
Manganese
Mercury
Zinc
Surface Water
Criteria (ug/L)
0.014(c)
3000(a)
3.9(3), l.l(c)
16(a), life)
5.2(c)
1000(c)
1500(a)
0.012(c)
120(3), 110(c)
Stream Concentrations (ug/L)
G. mean
0.5
9.3
2.1
5.2
11
1800
85
0.14
27
Maximum
15
5200
52
95
20
330000
7500
0.92
930
notes
The table only includes the chemicals for which either the acute (a)
or the chronic (c) water quality criteria are exceeded
TABLE 18b
COMPARISON OF ASSUMED SEDIMENT QUALITY CRITERIA TO
CONCENTRATIONS OF CHEMICALS FOUND IN STREAMS AT SMITH'S FARM
Chemical
Acetone
PCB 1254
Arsenic.
Cadmium
Chromium
Iron
Lead
Zinc
Sediment
Criteria (mg/kg)
0.22
0.20
1.0
0.007
0.22
25
3
4
notes
Stream Sediment Cone, (mg/kg)
6. Mean
0.021
0.17
9.4
1.5. -
24
3.4E+4
40
118
Maximum
1.2
2,3
56
6.3
120
1.1E+5
990
380
Values are for an assumed organic carbon concentration in sediment of
1%
The table only includes the chemicals for which the assumed sediment
quality criteria are exceeded
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Risks to workers or nearby receptors from implementation of this
alternative would be minimal or would not increase during remedial
action at the site. Long-term risks would be unchanged, other than
changes that will occur from natural processes. No reduction in
toxicity, mobility, or volume of contaminants would occur under this
alternative. Protection of human health and the environment would be
minimal.
The "No Action" alternative would be easy to implement. The present
worth cost of this alternative is estimated at $1,103,000. This cost
results largely from the long-term monitoring/site assessment that
would be performed. Capital cost is estimated to be $320,000 and
operation and maintenance costs are estimated to be $783,000.
Compliance with surface water and ground-water ARARs would not occur
under this alternative, because no cleanup of the site to meet
water-quality criteria would occur.
Because this alternative does not result in the remediation of the
contamination from the Study Area, the alternative is unacceptable to
the Commonwealth of Kentucky. Based upon a limited response, the
alternative is also unacceptable to.local citizens because of the
remaining health hazards associated with leaving the uncontrolled
site in its present condition.
7.2 RCRA Cap Alternative
The RCRA Cap alternative would involve the placement of a multi-media
cap over the areas contaminated by waste. Necessary design
considerations, as outlined in Covers for Uncontrolled Hazardous
Waste Sites. EPA/2-85/002 will be adhered to in the development of
the RCRA cap design.. The cap will minimize infiltration and leachate
formation. ;
This alternative would require the excavation of 26,000 cubic yards
of contaminated material from Area B and emplacement of the excavated
soil and debris into Area A, Slopes in Area B are too steep to
construct a waste repository there. Intact drums from Area B would
be hauled offsite and disposed of in accordance with all applicable
requirements.
In Area A, the topography .necessitates re-contouring of the slopes
and construction of retaining walls in order to accomodate the RCRA
cap alternative. Additionally, because of the continued presence of
drums and contaminated earth material, a leachate collection system
would be constructed in Area A. It is assumed that the leachate
volume will be approximately 500 gallons per year....The leachate
would be drained into storage tanks which would periodically be
pumped and the liquid would be transported off site for treatment and
disposal at a RCRA-approved facility.
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During the construction of this alternative, site workers would be
protected from fumes and dust that might be generated. Risks to
persons offsite are considered low. The construction period for the
RCRA cap alternative is estimated to be approximately two years.
Design and preparation activities would require approximately one
year.
The long-term effectiveness for this alternative is considered
acceptable, provided that periodic inspections and required
maintenance are performed. Catastrophic failure of the RCRA cap and
containment system could pose a serious problem, but with the proper
design, the probability of this occurring is considered to be
remote. Overall protection of human health and the environment will
be achieved because the RCRA cap and leachate collection system will
isolate the waste materials. This alternative leaves untreated
waste in place and thus does not comply with the intent of SARA with
regard to the reduction of waste toxicity, mobility, or volume.
This alternative would comply with chemical-specific ARARs because
soil containing contaminants above cleanup levels would be isolated
and all associated exposure pathways would be broken. No
location-specific ARARs would apply to this alternative.
Action-specific ARARs would include RCRA standards for cap
construction and requirements related to protection of on-site
workers. Most RCRA requirements are not triggered because waste
would be excavated for purposes of. consolidation and would not be
treated. The requirements for RCRA cap construction would be met.
OSHA health and safety regulations would be followed by site workers
during construction. .
This alternative requires a relatively sophisticated engineering
design to assure the effectiveness and safety of the cap and leachate
collection system.- The steep slopes would pose a difficult, but not
insurmountable, impediment towards, implementation of this remedial
alternative. . . .
The estimated present worth cost of this remedial alternative is
$11,397,000. Construction costs for this alternative are estimated
to be $10,067,000:. Costs for operation and maintenance of the cap
and leachate control system are estimated to be $1,330,000.
The Commonwealth of Kentucky believes that the construction of a cap
in Area A would be very difficult from an engineering perspective and
thus does not favor this remedial alternative. The local community
has expressed some concern about leaving untreated wastes in place
and therefore does not favor this alternative.
7.3 Incineration, Solidification/Fixation, and On-Site Disposal
This alternative involves the on-site treatment of wastes and
Contaminated soil. Organic contaminants would be thermally destroyed
. -59-
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by incineration. Metals left in the incinerator residue would be
immobilized by solidification/fixation.
This alternative would require the excavation of all contaminated
soil and drums from the Study Area, an estimated volume of 178,000
cubic yards of material. Approximately 5,200 cubic yards of
contaminated creek sediments would also be treated. Intact drums
would be carefully excavated then transported to a staging area where
their contents would be tested to avoid mixing incompatible wastes
when they are incinerated. Waste materials would be stockpiled on
site to keep the incinerator running when inclement weather or other
factors prevent waste excavation.
Excavation and waste transport could potentially generate additional
short-term contamination at the site. The risks to on-site workers
and to environmental receptors would be controlled by dust-
suppressant measures, erosion controls, and air pollution control
equipment on the incinerator. Risks to the local residents would be
minimal.
The long-term effectiveness of this alternative is considered to be
excellent. All contaminated material would either be destroyed or
would be immobilized, and a significant reduction in toxicity,
mobility and volume of the wastes would be achieved. The
technologies that would be used at the site are proven. Long-term
management and monitoring activities would be small in comparison to
most of the other alternatives presented.
This alternative would be difficult to implement. It would require a
comoKehensive monitoring program, and extensive site construction and
preparation would be required. The time to complete the remedial
work of this alternative would be approximately seven years.
The estimated present worth cost for this alternative is
approximately $95,600,000. The construction cost for this
alternative is estimated to be $95,173,000, and the operations and
maintenance cost is estimated to be $419,000. The high cost for this
alternative is, among other things, related to the rugged terrain of
the site and the heterogeneity of the waste materials that would be
incinerated.
This alternative" complies with most ARARs. The solidified material
that would remain may contain inorganics in excess of cleanup levels,
but the material would be treated to immobilize the waste and inhibit
leachate generation. The alternative would comply with all
location-specific ARARs. Requirements for incinerator operation
included in 40 CFR Part 264 and 40 CFR Part 761 would be met by this
alternative through proper design and operation of the incinerator.
Incinerator stack emissions would meet.provisions of the Clean Air
Act. The alternative would meet all Land Disposal Restrictions in 40
CFR Part 268 becuase this alternative would treat waste to levels
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achievable under the best demonstrated treatment (BOAT) technology.
RCRA requirements for closure and land treatment would not be
applicable because it is assumed that the solidified incinerator
residue would be demonstrably nonhazardous.
The alternative is protective of human health and the environment,
since all contaminants contained in the soil would be destroyed or
immobilized. Contaminant concentrations in ground water, surface
water, and stream sediments are expected to decrease rapidly once the
contaminant source is removed.
The Commonwealth of Kentucky has expressed concern about this
alternative because of the paucity of information concerning the
specific wastes and volumes of different waste components present in
the areas to be remediated. The overall cost of this remedial
alternative presents a state funding problem. The local community
has expressed concern about the efficiency of the incinerator and the
safeguards to prevent air emissions of toxic materials. Some
citizens have also expressed a concern that an on-site incinerator
would be used to treat waste from other locations.
7.4 Capping of Area A, Incineration and Solidification/
Fixation of Area B
This alternative provides elements of the RCRA cap and incineration
alternatives discussed previously. Steep slopes in Area B preclude
capping of this area. This alternative would result in the removal
and destruction of contaminants from Area B and the capping of wastes
in Area A.
Area B wastes would be excavated and incinerated prior to capping df
Area A. Simultaneously, trenches would be excavated in Area A to
obtain additional information concerning the nature and volume of
wastes of Area A. Further characterization of Area A would guide
subsequent remedial activity in that area. Regrading and waste
consolidation in Area A would provide additional information on the
type and locations of wastes in Area A. Conceivably, wastes from
Area A could be handled differently if assumptions regarding the
nature of wastes in the Study Area prove to be incorrect. The time
required to treat Area B wastes would be approximately three years;
the time required to complete remedial work at Area A will depend
upon the combination of remedial technology that is most appropriate
for this area. ...
Short term site conditions and remediation requirements would be
similar to those listed in the incineration alternative above, but
will occur in a shorter time period and at a reduced scale. The
short term conditions of the RCRA cap alternative will also occur
during the site remediation.
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Long-term effectiveness is considered to be good for this
alternative. For Area B, the long term and implementability
conditions discussed under the incineration alternative will apply.
For Area A/ the long term and implementability conditions will
essentially be those described under the RCRA cap alternative. A
significant reduction of toxicity, mobility and volume of
contaminants will occur in the Study Area.
The estimated present worth cost for this alternative is
approximately $26,900,000. The cost for construction and
implementation of this alternative is estimated to be $25,561,000,
and the operations and maintenance costs are estimated to be
$1,330,000. The cost for ths alternative is dependent upon the
actual volume of waste material that will be incinerated. The
Feasibilty Study report describes how the costs for this alternative
will vary depending upon the actual volume of incinerated material.
The ARARs associated with this remedial alternative are a combination
of those applicable to the incineration and RCRA cap alternatives.
This alternative will comply with chemical-specific,
location-specific, and action-specific ARARs. This alternative is in
partial compliance with the intent of SARA. Cap construction over
Area A is not in compliance because waste is being left in place
untreated.
The Commonwealth of Kentucky has expressed concerns about this
alternative because of the perceived engineering difficulties for
implementing the alternative and has concerns about the incineration
of material without more complete knowledge of its characteristics.
The local community has expressed concerns about on-site incineration
and about leaving untreated wastes on site.
7.5 Off-Site Incineration and Off-Site Disposal .
This alternative would require the excavation of approximately
178,000 cubic yards of contaminated material from the Study Area and
the removal of approximately 5200 cubic yards of contaminated
sediments and the transport of that material to an acceptable
location -for incineration and disposal of residuals. Short-term
conditions on site would require the use of extensive measures to
protect the health and safety of workers and to protect the
environment.. There also would be an element of risk to nearby
residents posed by the transport of wastes on public roads.
The long-term effectiveness of this remedy would be very good.
Long-term site management would be minimal. Toxicity, mobility, and
volume of wastes in the Study Area would be significantly reduced.
Similar to some of the other alternatives, this option will be
difficult to implement during on site construction and excavation
activities because of the steep slopes and other site conditions.
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There may also be difficulties associated with locating an approved
facility to incinerate the wastes and to accept residual materials
for disposal. Waste would have to be treated to meet Land Disposal
Restriction requirements before it is disposed. The time required to
complete this alternative is estimated to be 2 years.
This alternative is the most expensive of the options considered.
The estimated present worth cost for this option exceeds
$437,000,000. Total capital cost is estimated to be $437,462,000,
while operations and maintenance are projected to cost $233,000.
This alternative would be protective of human health and the
environment, and would comply with all ARARs. Residuals would be
disposed of in a RCRA subtitle C hazardous waste landfill that would
meet the appropriate ARAR RCRA requirements. All soil containing
contaminant concentrations above the selected clean-up level would be
removed so that the RCRA ARAR concerning clean-closure requirements
(40 CFR Part 264) would be met. Transportation of contaminated
material would be in accordance with apprpriate regulations.
The Commonwealth of Kentucky does not favor with this alternative
because of its extremely high cost. Several individuals in the local
community have expressed a preference for this alternative because it
removes the risks associated with the site without on-site
incineration.
7.6 Comparison of the Alternatives
Table 19 summarizes the major factors that were weighed when
selecting the preferred alternative from the five alternatives listed
above. These factors are also discussed in the .narratives describing
each of .the remedial actions that were considered for the Study Area.
The alternatives are listed in Table 19 as follows*
0 Alternative 1- No Action: No Action
0 Alternative 2- RCRA Cap: Cap
0 Alternative 3- On Site Incineration,
Solidification/Fixation and Disposal: On Site
° Alternative 4- Capping of Area A, On Site
Incineration, Solidification/Fixation and
Disposal for Area B: Cap/On Site
0 Alternative 5- Off Site Incineration and Disposal:
Off Site
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TABLE 19
COMPARISON OF THE FIVE REMEDIAL ALTERNATIVES
Criteria
No Action
Alternative
Cao On Site
Cap/On Site Off Site
Effectiveness/
Environmental
Protection
Compliance
with ARARs
minimal
no
Implementability easy
Cost (million $) 1.1
Estimated Time to
Complete (years) <1
Community
Acceptance
State
Acceptance
least-t-*-
OK OK
some most
hard hard
11.4 95.6
no++ no*
no* no
2,3
OK
3+
no++*
no
OK
most
hard
26.9
yes
hard
437
most
no*
notes
+ time to completion is dependent upon the exact
amount of material incinerated
++ unacceptable because untreated waste is left on
site
* unacceptable because of concerns with incinerator
operation '
1 unacceptable because of limited environmental
protection
2 unacceptable primarily because of technical
issues
3 unacceptable because of cost considerations
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7.6.1 Overall Protection of Human Health and the Environment
Alternatives 2 through 5 would be protective of human health and the
environment. Either the waste will be isolated from the environment
(Alternatives 2 and 4) and/or the waste will be treated to levels
that are protective of human health and the environment (Alternatives
3,4, and 5). Alternative 1 does not provide adequate protection of
human health and the environment because wastes will neither be
treated nor isolated from the environment.
7.6.2 Compliance with ARARs
Alternative 5 would comply with ARARs but would involve the transport
of wastes off site for treatment. Alternative 3 would comply with
most ARARs. Inorganics in the incinerator residuals could exceed
cleanup levels, but would be immobilized by solidification/fixation*
Alternative 4 combines elements of Alternatives 2 and 3. Alternative
4 would not fully meet SARA'S preference for treatment because some
waste would be left untreated. Alternative 2 would comply with ARARs
but would not meet SARA'S preference for treatment because
contamination would be left untreated. Alternative 1 would not
comply with ARARs because ground water and surface water quality
would continue to be degraded above relevant and appropriate Federal
and State regulatory standards. ' .
7.6.3 Long Term Effectiveness and Permanence
Alternative 3 would result in little long term maintenance and
potentially will be more effective than alternatives. 1, 2, or 4,
becuase waste will be treated rather than contained. Alternative 5
would be as effective as Alternative 3 because waste will bo treated;
furthermore, the residuals will be removed from the site.
Alternative 2 requires periodic maintenance of the RCRA cap, leachate
collection system and other components of the remedy. As designed,
this alternative would be effective over a long period, but has the
potential for being less effective than an alterntative that treats
the waste. Alternative 4 combines elements of alternatives 2 and 3
and the long-term effectiveness of this alternative will be at least
as good as the long-term effectiveness of Alternative 2. Alternative
1 would not be effective because wastes would be left in place
untreated, and exposed to the environment. .
7.6.4 Reduction of Toxicity, Mobility or Volume Through Treatment
Alternative 5 will result in complete reduction of toxicity, mobility
and volume of wastes at the site, because all wastes will be removed
and treated off site. Alternative 3 will be almost completely
effective in reducing the toxicity and mobility of the wastes and
will result in some volume reduction. Alternative 4 will result in
some reduction of toxicity and mobility of the waste and will result
in a minor reduction in volume. Alternatives 1 and 2 will result in
no reduction of toxicity, mobility or volume through treatment.
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7.6.5 Short-Term Effectiveness :
Alternative 2 would probably have the shortest time period between
implementation of the remedy and the completion of the remedial
actions needed to protect human health and the environment.
Alternative 5 would require approximately the same amount of time for
remedy completion of Alternative 2, provided that a facility for
treatment and disposal of the waste could handle the wastes
expeditiously. Alternative 4 would probably require more time than
Alternatives 2 or 5. Alternative 3 would require several more years
to complete than Alternatives 2, 4, or 5. Alternative 1 would
require the least of amount of time to complete but would not achieve
protectiveness of human health and the environment.
7.6.6 Implementability
Alternative 1 would be the most readily implemented. Alternative 2
would probably be easier to implement than any of the remaining
alternatives but would be much more difficult to implement than
Alternative 1. Alternatives 3, 4, and 5 would be difficult to
implement. It is difficult to predict which would most readily be
implemented.
7.6.7 Cost '
Alternative 1 is the least costly. Alternative 2 is considerably
more costly than Alternative 1. Alternative 4 is more costly than
Alternative 2. Alternative 3 is considerably more costly than
Alternatives 1,2, or 4, but is much less costly than Alternative 5.
Alternative 5 is very costly.
7.6.8 State Acceptance
Alternative 1 is least acceptable to the state because it does
nothing to protect human health and the environment. Alternatives 3
and 5 are prohibitively expensive to the state; otherwise, these
alternatives would probably the most favorable. Although
Alternatives 2 and 4 are not favored by the state,-these options
would be most acceptable considering the protectiveness and cost
factors.
7.6.9 Community Acceptance
Alternative 1 is the least favored alternative to the local community
because it does not protect human health and the environment.
Alternatives 2, 3, and 4 are probably equally acceptable to the
community; concerns about leaving waste capped and in place are
probably somewhat less than concerns about operation of an on-site
incinerator, but individuals in the community have expressed concerns
about both of these issues. Alternative 5 would be the most
acceptable to the local community, based upon comments made at the
public meeting to discuss the proposed plan.
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8.0 THE SELECTED REMEDY
Based upon consideration of the requirements of CERCLA, the detailed
analysis of the alternatives, and public comments, EPA has determined
that Alternative 4: Capping of Area A, Incineration and
Solidification/Fixation of Area B is the most appropriate remedy for
the Smith's Farm site, Operable Unit 01, Brooks, Kentucky.
Approximately 26,200 cubic yards of contaminated soil, surface drums,
buried drums, and fill material will be excavated from Area B.
Approximately 5,200 cubic yards of contaminated on-site sediments
will also be excavated from the intermittent valley streams within
the Study Area of the Smith's Farm site. The contaminated sediments
and material from Area B will be treated using a thermal destruction
unit. Approximately 50% of the treated material will then be further
treated by solidification/fixation. Solidified material and treated
soils will then be returned for placement into Area B.
Wastes within Area A will be consolidated and capped with an
engineered cap in accordance with Federal and State requirements. In
addition to capping Area A, the alternative includes the incineration
of an as yet undetermined but minor volume of material in Area A.
Prior to capping, exploratory investigations will be performed in
Area A to further define the volume and nature of contaminants within
that area. Upon completion of the remedial design and/or the waste
consolidation, regrading, and exploratory investigation of Area A,
the exact volume and location of material in Area A that will be
incinerated will be determined. Criteria that will be used to
determine the material to be incinerated are the numbers and
locations of intact drums or waste "hot spots" that are uncovered in
Area A and cost considerations. The treatment of selected Area A
wastes would be the same as the treatment of Area B wastes.
8.1 Remediation Goals
The purpose of this remedial action is to reduce present risks posed
by direct contact with Study Area soils contaminated with PCBs and
lead, sediments contaminated with PAHa and,PCBs within the Study
Area, and inhalation of organics and PCBs from surface water within
the Study Area. The risks posed to potential future on-site
residents from contaminated ground water will also be reduced.
This remedy will address soils and/or sediments contaminated with
lead, PCBs, and carcinogenic PAHs in excess of SOOppm, 2ppm, and
Sppm, respectively. These action levels are based on the plausible
maximum exposure scenario and under that scenario, correspond to an
excess lifetime cancer risk of 10- , with the exception of the
action level for lead, which is considered by EPA as an appropriate
soil lead cleanup level based upon a 1985 Center for Disease Control
recommendation. These action levels are presented in Table 20.
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TABLE 20
ACTION LEVELS FOR SOILS AND SEDIMENTS
FOR THE SMITH'S FARM SITE STUDY AREA OPERABLE UNIT 01
Contaminant
Lead
PAHs
PCBs
PCBs
Media
Soil
Sediment
Soil
Sediment
Unit
mg/kg
mg/kg
mg/kg
mg/kg
Action Level
500
5
2
2
Risk Level
NA+
10-5
10-5
io-5
notes
+ NAs not applicable. The hazard index associated with this action
level would be reduced to less than 1.
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Health-based action levels were developed only for those contaminants
and exposure pathways that, in the baseline risk assessment, had
shown either a potential excess lifetime cancer risk greater than 1 x
10~6 or a CDI:RfD ratio greater than one. Since no Federal or
State ARAHs exist for soil or sediments, the action levels were
determined through a site-specific analysis. This analysis involved
direct use of the Remedial Investigation monitoring data from
environmental media and development of pollutant transport models to
predict the migration of contaminants. Action levels are not
required for contaminants and exposure pathways with risks less than
those stated above, since the concentrations present already meet the
action levels. Because of the effects of the source area remediation
components of Alternative 4, surface water and shallow ground water
remediation is not considered necessary. Thus, action levels for
these pathways have not been established in this Record of Decision.'
However, contaminated seep discharges and ponded areas near the drum
disposal sites with contaminant concentrations exceeding health-based
action levels will be eliminated by the remedial action.
EPA guidance recommends the development of action levels in the risk
range of 1 x 10"4 to 1 x 10"7. The action levels of 2ppm for
PCBs, and Sppm for PAHs represent, as stated previously, a 10~5
risk level and were selected based upon factors such as the proximity
to residential areas, risk to site trespassers, lack of site access
deterrents, use of the maximum plausible values to estimate chronic
daily contaminant intake levels, and action levels selected at other
NPL sites having similar contaminants and site conditions. The
action level of SOOppm for lead represents, as stated previously, a
risk level selected on the basis of lead's toxicity to humans.
The excavated soils and sediments will be treated on-3ite using a
mobile thermal destruction unit that will remove organic contaminants
to the specified action levels. Residuals from the thermal
destruction unit will be further treated to immobilize the remaining
inorganic contaminants. At the completion of the remedial action,
health risks posed by direct contact with the treated soils and
sediments would be no greater than 10" .
This remedy will also serve to contain contaminants within Area A,
thereby eliminating or greatly reducing infiltration of rainfall into
this area. Containment of contaminants within Area A would eliminate
the pathway by which contamination is entering the surface water, as
well as the direct contact exposure pathway which is the basis for
the majority of the unacceptable risk levels at the site. Surficial
ground water recharge would be eliminated or greatly reduced by
placement of a cap over Area A since this area receives recharge
through surface water infiltration. Leachate collection and
treatment would serve to eliminate or greatly redi.ce the accumulation
of leachate that may still be generated as a result of leaking,
buried drums within Area A. The cap will be designed and constructed
to minimize the amount of leachate generation, promote drainage,
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minimize erosion of the cover, and provide long-term minimization of
migration of liquids through the underlying drums and soil.
8.2 Attainment of Applicable or Relevant and Appropriate
Requirements of Environmental Lavs
8.2.1 Soil, Sediment, and Source Materials ARARs
Alternative 4 is designed to meet all applicable, or relevant and
appropriate requirements (ARARs) of Federal, and more stringent,
State environmental laws. The Federal ARARs include the Resource
Conservation and Recovery Act (RCRA) (42 USCA Section 6901 et seq and
40 CFR Parts 257, 260, 261, 262, 263, 264, 268, and 269), the Toxic
Substances Control Act (40 CFR Part 761), the Clean Air Act (42 USCA
Section 7401 et seq and 40 CFR Part 50 and 61), and the Occupational
Safety and Health Administration Act (40 CFR 1910). Potential State
ARARs include: 601 KAR 1:025 Transportation of Hazardous
Materials and KRS 174.415 Hazardous Materials, Permits, Emergency
Procedures, Enforcement; 401 KAR 3«:240.f 50:025, 51:010, 51:052,
53:010, 63:010, 63:020, 63:021, ana 63:005 pertaining to air
pollution control requirements; and 401 KAR 34:070, and 47:040
pertaining to deed notices on solid or hazardous waste sites.
A. Federal Resource Conservation and Recovery Act
RCRA regulations will be applicable to the waste removed from the
Study Area for incineration treatment. All such material will be
considered RCRA characteristic waste, unless proven otherwise, or
unless the waste is regulated by another statute such as the Toxic
Substances Control Act.
Upon consolidation of drum waste and contaminated soils, Area A will
be capped. Because disposal of hazardous waste at the Smith's Farm
site Study Area occurred prior to the effective date of the RCRA
regulation, the RCRA closure regulations are not applicable.
However, they are considered relevant and appropriate. The relevant
and appropriate requirements of RCRA Subtitle' C regulations will be
met by the selected remedy.
RCRA closure and post-closure requirements for all hazardous waste
management facilities are outlined in 40 CFR Subpart G. Section
264.310 of RCRA Subpart N specifies the performance-based
requirements for a cover at final landfill closure. The cover system
for Area A in Alternative 4 will be a cap as prescribed in RCRA
guidance and will comply with RCRA regulations. The cap will
minimize migration of liquid through the landfill, function with
minimum maintenance, promote drainage, minimize erosion, minimize
leachate generation, accomodate settling, and be less than or equal
to the permeability of natural subsoils present.
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RCRA Land Disposal Restrictions for the disposal of hazardous waste
are included in 40 CFR Part 268. 40 CFR Part 268 Subpart D requires
treatment by the best demonstrated available technology (BOAT) before
land disposal of RCRA-similar wastes. The treatment of wastes
excavated from the Study Area will meet this requirement.
After closure is completed, the substantive monitoring and
maintenance post-closure requirements contained in Section 264.117
through 264.120 of Subpart G will be conducted. Area A will be
capped according to the standards in Subpart 6 Section 264.111 -
Closure Performance Standards. After the closure activities have
concluded, a survey plat, as prescribed in Subpart 6 Section 264.116,
indicating the location and dimensions of the disposal area
will be submitted to the local zoning authority, or to the authority
with jurisdiction over local land use, and the Regional Administrator
(Director, Division'of Waste Management, Kentucky Natural Resources
and Environmental Protection Cabinet).
The drum wastes and contaminated soils removed from Area B, other
areas within the Study Area, and Area A must be properly disposed of
or decontaminated as required in Subpart G Section 264.114. If it is
determined that a portion of the wastes must be incinerated off-site,
these wastes will be staged and repackaged on-site, and transported
off-site for incineration at a RCRA treatment facility operating in
compliance with 40 CFR Sections 264.340 through 264.351. The
excavated waste will also be handled as regulated by Part 262
Standards Applicable to Generators of Hazardous Waste and will be
transported in accordance with Part 263 Standards Applicable to
Transporters of Hazardous Waste.
It is anticipated that the majority of the waste will be incinerated
on-site and the on-site incinerator will be operated in compliance
with the technical requirements of Subpart 0 Sections 264.340 through
264.351 and more stringent'state requirements;, as appropriate.
Incineration residuals will be treated by solidification/ fixation
and it is anticipated that t:hese residuals will be rendered non
hazardous. Residuals will be tested by the appropriate method listed
in Part 261 before being disposed to assure that the waste is not EP
toxic characteristic (as defined in Subpart C, Section 261.24) and
will if appropriate be evalauted using the TCLP test procedure (Part
268 Appendix I) to assure that the waste is not otherwise hazardous.
Demonstration of the waste being rendered non hazardous will be used
so that the regulations applicable to hazardous waste landfills (Part
264, Subpart N) are not applicable for the disposal of the treatment
residuals.
B. Federal Clean Air Act
The Clean Air Act (CAA) identifies and regulates pollutants that
could be released during earth-moving activities associated with
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the excavation and on-site incineration of soils, sediments/ and drum
wastes of the Smith's Farm Study Area. The CAA Section 109 outlines
the criteria pollutants for which National Ambient Air Quality
Standards have been established. CAA Section 112 identifies
pollutants for which there are no applicable Ambient Air Quality
Standards/ those substances regulated under the Federal National
Emmission Standards for Hazardous Pollutants. The CAA is an ARAR and
the regulations standards will be complied with during implementation
of Alternative 4. More stringent state regulations concerning the
release of toxic air emissions will also be met.
C. Toxic Substances Control Act (TSCA)
The incineration of wastes containing polychlorinated biphenyls in
concentrations greater than 50 ppm must be in accordance with TSCA
regulations (40 CFR Part 761), in addition to the applicable
incineration regulations in 40 CFR Part 264. Incineration of any
wastes containing PCBs in excess of 50 ppm would comply with the TSCA
regulations.
O. Federal Occupational Safety and Health Administration Act (OSHA)
The selected remedial action contractor must develop and implement a
health and safety program for its workers, if such a program does not
already exist. All on-site workers must .meet the minimum training
and medical monitoring requirements outlined in 40 CFR 1910. OSHA
will also be complied with when construction of subsequent operable
units at the site (if the subsequent operable unit RI/FS determines
the necessity of remedial action).
8.2.2 Ground Water/Surface Water ARARs
Alternative 4 is designed to meet all applicable, or relevant and
appropriate requirements of Federal, and more stringent, State
environmental laws. Three groups of Federal environmental standards
and criteria are considered ARARs for the ground water at the Smith's
Farm site Study Area: Safe Drinking Water Act Maximum Contaminant
Levels (MCLs), RCRA Ground Water Protection Standards, and Clean
Water Act Ambient Water Quality Criteria. These are ARARs for ground
water protection beneath the capped area of Area A, as well as for
the affected ground water of the surficial aquifer downgradient of
the Study Area. The CWA regulation is likewise an ARAR for
protection of surface water relative to the Study Area.
Potential State ARARs for the regulation of surface water at the site
which are more stringent than Federal requirements are included in
the Kentucky Administrative Regulations, Title 401, Chapter 5:031.
Bluelick Creek, and its tributaries which receive drainage from the
Smith's Farm Study'Area, are not specifically listed in the
regulations. Therefore, contaminant-specific surface water quality
standards for use as a warmwater aquatic habitat and domestic water
supply would apply to Bluelick Creek and its tributaries.
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A. Federal Ground Water ARARs
Maximum Contaminant Levels established under the Safe Drinking Water
Act are ARARs at this site. MCLs are the maximum contaminant
concentrations allowed in a regulated public water supply. These
levels apply at the point of distribution ("at the tap") to public
water systems having at least 15 service connections or regularly
serving at least 25 individuals. Levels are based on a chemical's
toxicity, treatability (including cost considerations), and
analytical limits of detection.
MCLs are relevant and appropriate at the Smith's Farm Study Area for
ground water protection because the aquifers beneath the site have
been, and currently are being, used as a source of drinking water,
and MCLs are the enforceable drinking water standard for public water
supplies. Since MCLs apply to water at the point of use, these
levels are appropriate for establishing water quality in the drinking
water aquifers at the site. Ground water tapped for drinking water
generally has minimal or no treatment. These standards will be
applied to the ground water itself to ensure safe levels below the
MCLs for the shallow ground water downgradient of the site.
B. Federal Surface Water ARAR Ambient Water Quality Criteria
(AWQC) established under the Clean Water Act (CWA)
The CWA is an ARAR at this site since ground water eventually
discharges to the surface water (Bluelick Creek and its
tributaries). The AWQC are established for protection of freshwater
aquatic organisms. AWQC will be met at the point the ground water
discharges to the closest surface water body. Monitoring shallow
ground water, upgradient of the surface water body, will assure
compliance with AWQC.
C. Potential State Surface Water ARAR Title 401, Chapter 5:031
Criteria listed for waters used as a warmwater aquatic habitat were
more stringent than potential Federal ARARs for three contaminants.
These contaminants and their maximum allowable concentrations in
surface water are PCBs (0.0014 ug/1), mercury (0.2 ug/1), and zinc
(47 ug/1). .
D. Potential State Surface Water ARAR TitJ.e 401, Chapter 34:020
This potential state ARAR involves the construction of a waste
facility in a flood-prone area or such that flooding hazards are
increased. The remedial design for the selected remedy will consider
flood-prone areas.
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8.3 Coat-Effectiveness
The selected remedy is cost-effective because it has been determined
to provide overall effectiveness proportional to its costs, the net
present worth value being $ 26,891,000. The estimated costs of the
selected remedy are less than an order of magnitude of (16.3 times
less) the estimated costs associated with off-site treatment and
disposal (Alternative 5) and within an order of magnitude of (3.6
times less) the estimated costs of complete on-site treatment and
disposal (Alternative 3), and yet the selected remedy will provide
for an equal degree of protection to public health and the
environment, achieves a significant reduction of toxicity, mobility,
or volume, and meets the statutory preference for on-site treatment
of contaminants.
8.4 Utilization of Permanent Solutions and Alternative Treatment
Technologies (or Resource Recovery Technologies) to the
Maximum Extent Practicable
EPA has determined that the selected remedy provides the best balance
of permanent solutions and treatment technologies that can be
utilized in a cost-effective manner for Operable Unit 01 at the
Smith's Farm site. The selected remedy provides the degree of
>flexibility necessary to refine (after completion of exploratory
investigations into Area A) remedial activities for Area A due to the
inherent uncertainties associated with waste volume and estimates and
waste characteristics in uncontrolled drum disposal areas. 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, also
considering the statutory preference for treatment as a principal
element and considering State and community acceptance.
While the selected remedy does not offer as high a degree of
long-term effectiveness and permanence as on-site incineration and
solidification/fixation of all waste (Alternative 3), it will reduce
the inherent hazards posed by the contaminated soils and sediments
through thermal destruction of a significant amount of organics and
immobilization of a significant amount of inorganics in Area B,
thermal destruction of orgahics and immobilization of some inorganics
in Area A, and containment of the remaining wastes within Area A such
that the contained waste can be controlled and monitored. Thermal
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destruction of organics within Areas A and B and in the creek
sediments of the valley streams will eliminate unacceptable levels of
risk associated with those contaminants. Solidification/fixation of
residual inorganics will physically and chemically lock contaminants
within the soldified mass, thereby eliminating unacceptable levels of
risk associated with those contaminants. Containment of wastes
within Area A would serve to isolate contaminants and all associated
exposure pathways would be broken.
Requirements for the thermal destruction unit are included in 40 CFR
264 and 40 CFR 761 and include disposal of residues, removal
efficiencies for various waste types and monitoring of various
parameters during operation. The incineration equipment to be
installed at Smith's Farm would be designed and operated to comply
with all of these requirements. Air pollution control equipment
would be installled to conform to provisions of the Clean Air Act
and, specifically, in accordance with 40 CFR Part 264.343, at least a
99.99 percent destruction and removal efficiency on stack emissions
would be achieved, and will conform with 40 CFR Part 761.70, as
appropriate.
Solidification/fixation of residuals from the thermal destruction of
wastes would transform the hazardous constituents (inorganics)'into
relatively inert material with respect to the generation of
leachate. This is accomplished by the mixing of the waste with
pozzuolanic materials such as lime, fly ash and cement kiln dust.
Significant changes in physical properties of the waste occur upon
completion of the cementat-ious reaction, including an increase in
physical strength and a decrease in permeability. Implementation of
the solidification/fixation technology at other NPL sites has shown
that, due to changes in the physical properties, leaching of
hazardous constituents from the solidified material is significantly
reduced, often to the point where the material can remain in place
with no risk of hazardous leachate generation. 'Treatability tests
would be performed on the waste during remedial design to determine
the proper waste/additive ratio and to assure that the solidified
mass meets leachability requirements. The treated waste will be
tested as necessary to demonstrate that it is non hazardous.
While the containment of waste within Area A does not offer as high a
degree of long-term effectiveness and permanence as incineration or
off-site disposal o:f Area A wastes, it will serve to mitigate the
risks associated with exposure to contaminants and significantly
reduce infiltration of surface water. Contaminant migration would
also be curtailed through the collection and off-site treatment of
leachate from Area A. Periodic maintenance of the cap and leachate
collection systen would preserve the integrity and reliability of the
containment system.
The selection of treatment of contaminated soils and sediments of
Area B is consistent with program expectations that indicate that
treatment of highly toxic and mobile waste is a priority
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and is often necessary to ensure the long-term effectiveness of a
remedy. The major tradeoffs that provide the basis for this
selection decision are cost, reduction of toxicity, mobility, and
volume, and long-term effectiveness. The selected remedy combines
treatment of a significant portion of the waste in a cost-effective
manner, while at the same time including a degree of flexibility in
determining the most appropriate remediation for Area A. Thus,
Alternative 4 has been determined to be the most appropriate remedy
for Operable Unit 01 at the Smith's Farm site.
8.5 Preference for Treatment as a Principal Element
By treating a significant portion of the contaminated soils and
sediments at the Smith's Farm site through incineration and
solidificaiton/fixation, the selected remedy addresses one of the
principle threats posed by the site through the use of treatment
technologies. Therefore, the statutory preference for remedies that
employ treatment as a principal element is satisfied.
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RESPONSIVENESS SUMMARY
SMITH'S FARM SITE- FIRST OPERABLE UNIT
BROOKS, KENTUCKY
This responsiveness summary is divided into the following sections:
Section 1. Overview: This section discusses EPA's recommended
alternative for remedial action and public reaction to this
alternative.
Section 2. Background on Community Involvement and Concerns: This
section includes a brief history of community interest and concerns
raised during remedial activities at the Smith's Farm site.
Section 3: Summary of Malor Public Comments Received During the
Public Comment Period and EPA Responses to the Comments; Both the
comments and EPA responses to the comments are provided.
Section 4: Remaining Concerns: This section describes the remaining
community concerns that were .transmitted to EPA and that deal with
activities conducted during the remedial design and remedial action
project phases.
Section 1. Overview
EPA's preferred alternative for remed.Lal action at the Smith's Farm
site was presented:to the public through the Proposed Plan (released
on April 3> 1989) and at the public meeting on April 11, 1989. In
the Record of Decision, EPA has selected a remedial alternative
consisting of the placement of a "RCRA Cap" over part of the area of
contamination (Area A) and .the incineration and solidification/
fixation of soils, sediments, and drum wastes within Area B. This
alternative will involve the excavation and treatment of all
contaminated soil and drums in Area B and .the conso.lidation and
capping of contaminated soil and drums in Area A. Treatment is
provided for Area B because site conditions preclude capping there
and in keeping with SARA'S preference for treatment as well as a
significant reduction in toxicity, mobility or volume of wastes.
During remediation of Area B, additional data on the nature of
contaminants present in the study area would be collected, both from
that part of the site and through construction of several exploratory
trenches in Area A. A small amount of selected wastes identified
during exploratory work or waste consolidation conducted in Area A
will be treated by incineration arid solidification/fixation.
The community expressed no strong preference for any of the remedial
alternatives that were considered. Most comments from the community
concerned the use of an incinerator at the site.
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Section 2. Background on Community Involvement and Concerns
Media interest in both the Smith's Farm site and EPA's involvement
with the site has been fairly high, beginning with the immediate
removal action completed in 1984. Newspaper articles have documented
activities at the site throughout the Remedial Investigation and
Feasibility Study.
In contrast to the media interest, local interest in the site has
only been moderate. Some citizens living nearby have expressed
concern about uncontrolled site access, the potential for surface and
ground-water contamination from the site, and the nuisance caused by
trucks hauling waste materials to the Smith's Farm permitted
landfill. Many of the citizens near Smith's Farm have expressed
concern about the health hazards associated with the site. At the
public meeting in April 1989, the public's concern with health
hazards focused as much on the planned incineration of wastes as on
the threat from the uncontrolled site itself. Although a number of
comments and concerns were raised in the public meeting concerning
the proposed plan, only one follow-up letter was received from a
local citizen during the public comment period. Overall, however,
there has not been a great degree of public interest in this site
relative to many Superfund sites. Outside of the local area, and
aside from the media interest,, interest in the Smith's Farm site
seems to be minimal.
Section 3. Summary of Ma-lor Public Comments Received Purina the
Public Comment Period and the EPA Responses to the Comments
The comments include both those expressed at the public meeting on
the proposed plan on April 11, 1989, and the written comments
received during the public comment period from April 11 throughMay
2.
A number of comments were received from citizens during the public
meeting held on April 11:
1. One citizen: expressed a concern that the twenty-one day period
allotted for public comment on-the proposed plan was inadequate.
EPA Responsei The twenty-one day period is the time period required
by the National Contigency Plan (40 CFR Part 300, Section 300.67(d)).
2. Several citizens expressed concern that there is presently
uncontrolled public access to the Smith's Farm site. One citizen
also was concerned about site access during, and following, the
remedial action. .
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EPA Response: The access road leading into the property is blocked by
a locked gate so that unauthorized vehicular traffic cannot enter.
Warning signs have been placed around the site to notify persons that
it is a hazardous area and that entry should be avoided. Access will
be tightly controlled during the remedial action to assure that
unauthorized persons do not enter the site. Waste burial areas will
be posted and fenced off once remedial actions are completed.
3. Several citizens expressed concern that an incinerator brought to
the Smith's Farm site would be used to treat wastes brought in from
other locations.
EPA Responsei The Record of Decision specifies that the on-site
incinerator is for the treatment of wastes from Smith's Farm alone.
There are legal requirements concerning the transportation, storage,
treatment and disposal of hazardous wastes that would deter treatment
of wastes from off site locations. Additionally, it would not be
cost-effective to transport materials from another nearby Superfund
site and then to transport the residuals off site.
4.^Several citizens questioned EPA about transporting wastes from
Smith's Farm to either an operating or a proposed commercial
incinerator near the site for off-site treatment.
EPA Response; It would not be cost-effective to transport a large
volume of contaminated material from the site to a nearby off site
incinerator and then transport treatment residuals back to the site
for disposal. There would be risks to the community involved with
transporting the waste on public roads. It is uncertain, but very
doubtful, that the off-site incinerators would or could .(1) accept
waste materials from Smith's Farm; (2) treat the wastes to acceptable
standards considering both incinerator air emissions and requirements
for thermal destruction of organics; and (3) handle the wastes in an
acceptable time period.
4. Several citizens were concerned that the mobile incinerator would
not be operated correctly or could malfunction, releasing hazardous
materials into the air.
EPA Response t The incinerator will be thoroughly tested in trial
burns before being operated. It will be required to meet very
stringent air emission control standards mandated by the Clean Air
Act requirements, including restrictions on organic emissions and
emission of low boiling-point metals. During its operation, the
incinerator will be monitored to assure that it is operating
properly. Such incinerators have a proven record of success in
hazardous waste cleanup at other sites.
5. One citizen expressed a concern about the integrity and design of
the RCRA Cap that would be placed over some of the waste.
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EPA Responset The cap will be designed to withstand any earth
movements that might reasonably be expected in the area. The cap
will be periodically monitored and repaired if necessary. Leachate
draining from the fill beneath the cap will be collected and treated.
6. Several citizens believe that EPA should initiate some type of
health study of residents near the Smith's Farm site.
EPA Response; The threats posed to persons on the site have been
evaluated by the Agency for Toxic Substances and Disease Registry
through a Preliminary Health Assessment. A substantial amount of
data have been collected by EPA which7; indicate that there presently
is very little, if any, threat to persons living near the site who do
not enter the site itself. These data include stream water and
sediment samples and samples collected from private wells. If
contaminants are left on site above health-based levels, risk
assessment updates are required for the site once every five years,
to re-evaluate the risks posed by the|site.
7. Several citizens asked about how much weight EPA gave to community
concerns regarding the proposed plan. ;
EPA Response; The weight EPA gives to community concerns varies from
site to site'. Where a community is overwhelmingly and vociferously
opposed to EPA's proposed remedial alternative and the alternative
preferred by the community is as protective of human health and the
environment at a comparable cost and probable reliability, the
community's preference would probably be favored. In other cases, a
.proposed alternative would be somewhat/modified by EPA after
consideration of a community's concerns; In many cases, there are
other, more compelling considerations that EPA must take into
account. Such considerations would, for example, involve the
requirements of law (CERCLA, SARA, the Clean Water Act, etc.) or the
adherence to sound science and engineering practices.
X-V
8. One citizen had a concern about drinking water contamination. He
commented that EPA could pay for extension of a city water line to
supply citizens near the landfill with water at a cost far below the
projected cost for the preferred remedial action alternative.
EPA Responset Testing of water supply wells and streams in the area
of the site has not indicated that EPA: should provide water to nearby
residents. If further testing reveals that there is a health risk to
persons living near the landfill from their water supplies, EPA would
act to assure that these persons had a safe, reliable source of
drinking water.
9. Several citizens asked why EPA couldn't implement the most
expensive (and to them, the most acceptable) remedial action
Alternative 5, since EPA had the opportunity to recover the
expenditures from the PRPs.
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EPA Response t While it is true that EPA will seek to recover costs
associated with conducting the RI/FS, Remedial Design, Remedial
Action, and Operation & Maintenance, there is currently no agreement
with the PRPs for reimbursement of costs and it is unknown how long
the cost-recovery process might take.' The remedial action proposed
by EPA will be protective of human health and the environment. EPA
cannot justify choosing a much more costly remedial action over one
that is, overall, as protective of human health and the environment.
10. In addition to the comments made at the April 11 public meeting,
one citizen submitted a written comment expressing a preference for
Remedial Alternative 5. :;
EPA Response; EPA has selected an alternative that is as protective
of human health and the environment as Alternative 5. Based upon the
primary criteria of protectiveness and compliance with laws,
Alternative 4 is as environmentally effective and is more cost
effective than Alternative 5.|r
>.
Comments on the proposed plan were also received from one corporation
marketing a pollution control technology, a consortium of Potentially
Responsible Parties, and the Kentucky Resources Council.
11. The company marketing the pollution control technology advocated
the use of an in-situ vitrification technology to treat and
immobilize waste in place of the proposed alternative.
EPA Response; In-situ vitrification was considered in the Feasibility
Study but was dropped as a Viable approach to remediation at the
Smith's Farm site. This technology, while offering great promise in
the remediation of certain sites, may be inappropriate where areas of
buried drums are located. The. in-situ vitrification.technology does
not have the record of success Demonstrated by other thermal
destruction methods (incineration). Additionally, in-situ
vitrification would be difficult to implement properly because of the
steep terrain at the Smith's Farm site and would be resource and cost
intensive.
12. The Kentucky-Resources-Council expressed the opinion that the
site had not been characterized enough to support the selection of a
remedial alternative for the unpermitted disposal areas at the
Smith's Farm site.
EPA Response: EPA believes that the unpermitted drum disposal areas
have been characterized adequately to support the selection of the '
proposed remedial alternative. While the exact nature of the
contaminants buried in the unpermitted disposal areas is unknown, .the
following has been adequately established: (1) the waste materials
are heterogeneous, which limits the remedial alternatives that can be
selected; (2) the steep terrain in the disposal areas limits certain
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remediation options from consideration; (3) the approximate total
volume of wastes, including contaminated soil, is known; (4) the
proposed alternative provides for further site characterization
during remedial action; (5) the proposed alternative will
substantially reduce, if not eliminate, shallow ground-water
contamination in areas other than immediately beneath the capped
waste in Area A and the proposed alternative does not preclude
further ground-water remediation near the unpermitted disposal areas,
if found to be needed during the second operable unit RI/FS; (6) any
further characterization of waste materials in Area A or Area B will
involve intrusive measures which are also planned for the remedial
action, thus delay in remediation and witholding the selection of
remedy would probably not be balanced by the benefit of additional
characterization; (8) the success of the selected remedial action is
not contingent upon the additional investigation suggested by the
Kentucky Resources Council.
The total cost, and time period required to complete the remedial
action could be somewhat better defined by additional investigation,
but the benefit, if any, could be offset by the delays in remedial
action implementation and the additional expenditures involved.
13. The Kentucky Resources Council is also concerned that the
proposed plan does not address the risk posed by contaminated stream
sediments.
EPA Response; EPA concurs that there is a need for reducing the level
of risk posed by contaminated sediments in the valley streams within
the study area and intends to include such stream sediments with the
wastes to be treated in the remedial action.
14. The Kentucky Resources Council is also concerned about EPA's
plans or proposals to limit site access. .
EPA Response; Currently, trespassers may enter the site on foot. The
site has been posted to warn persons of the dangers on the site but
there are no other deterrents to access. Access will be curtailed
during and after site remediation begins. Persons who are intent on
gaining access to the site, will probably do so despite whatever
deterrent is in ^lace. The risks to both trespassers and the
environment will be most greatly reduced by the planned remedial
action.
15. The Kentucky Resources Council believes that the unpermitted
disposal areas should be tied in to the permitted disposal area for
remedial actions since the separation of these areas is an artificial
distinction not truly related to site conditions.
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EPA Response: EPA believes that while both the unpennitted drum
disposal area and the permitted landfill are a part of the NFL site,
there are some very real differences between the unpermitted and
permitted areas. The unpermitted drum disposal area is located in a
topographically different setting than the permitted landfill area.
Stream water and sediment samples collected to date suggest that
there are some differences in the contaminants leaching from the two
areas. Co-remediation of Area A with the permitted landfill would
almost certainly involve the transport, treatment, and burial of Area
A wastes in the location of the permitted landfill. In order to meet
legal restrictions for such an action, the waste would probably have
to be treated at a cost well in excess of the proposed Alternative 4,
without any offsetting increase in the protection of human health and
the environment.
16. The Kentucky Resources Council suggested that careful testing and
controls to prevent air pollution be implemented if on-site
incineration is part of the remedial action.
EPA Response; EPA agrees.
The consortium of Potentially Responsible Parties (the PRPs)
submitted a large volume of material concerning the Proposed Plan,
the Remedial Investigation (RI), the Endangerment Assessment (EA),
and the Feasibility Study (PS).
17. The PRPs suggested that the use of the maximum contaminant
concentrations detected in soil, water, and sediment at the Smith's
Farm site is inappropriate for use in calculating environmental
risks. They also objected to the use of summed values of PCBs and '-
PAHs from different locations for the maximum plausible case
exposures.
EPA Response; The use of maximum levels is consistent with EPA
guidelines on exposure assessments (Federal Register 51 34042-34054,
September 24, 1986; Federal Register 53 48830-48853, December 2,
1988). The guidance states that an exposure assessment may include a
sensitivity analysis or multiple scenarios; that is, the range of
possible exposures may be considered, from the minimum to the maximum
possible values/- Although the use of maximum values would tend to
overestimate risk, it is important to state the upper bound of the
risk associated with the site. The worst-case values were not used
alone to determine whether or not a problem exists at the Smith's
Farm site. The use of the summed PCB and PAH values results in a
more conservative estimate than would be the case if individual
sampling points were used. However, the difference is less than one
order of magnitude and has little impact on the results of the EA.
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18. The PKPs believe that estimated concentration values (denoted by
either a "J", which indicates an estimated value, or "N", which
indicates a presumptive evidence of the presence of material), are
not reliable. They therefore infer that any conclusions or
interpretations based upon such data are erroneous.
EPA Response: The PRPs interpretation of "J" and "N" data is
inconsistent with both EPA guidance and American Chemical Society
guidance (1983) for the evaluation of environmental data. "J" and
"N" values suggest uncertainty in the concentration level, but are
valid analytical results. These values have therefore been used,
with the qualification that they are estimates, in the EA.
19. The PRPs have objected to the use of one-half the detection limit
in calculating geometric mean concentrations.
EPA Response: Non-detect data present some problem for whatever
method is used to assign a value to them for geometric mean
calculations. It is true that in some cases, a value of one half the
detection limit would overestimate the true average concentration at
a sample location; it could also underestimate the true average at
that location. Geometric means were calculated only for those
chemicals that were detected in RI samples and are therefore known to
be present at the site. For background samples, where chemicals were
not detected, no geometric means were calculated. Use of one-half
the detection limit therefore in no way implies that non-detect
background levels would be considered a problem in the endangerment
assessment.
20. The PRPs believe that inappropriate health cmteria have been
used in the EA. 9- .
EPA Response: EPA disagrees with this conclusion. A value of 4.6E-03
(mg/kg/d)~A was used for the inhalation cancer potency factor for
trichloroethene. This value is based on the 1984 Health Effects
Assessment cited in the EA. The Health Effects Assessment lists a
potency factor for an absorbed, metabolized dose of 1.3E-02
(mg/kg/d)~. In order to use this value for risk assessment, it
must be converted to an ambient-dose value, which was done for the
EA. The PRPs have misinterpreted the data obtained from the Health
Advisory Document Addendum. The value of 1.7E-06 cited in that
document is a unit risk (units of ug/m3), not a cancer potency
(units of mg/kg/d"-1-). A unit risk is the excess lifetime cancer
risk associated with exposure to 1 ug/nr* of a chemical. Conversion
of the unit risk to the potency factor gives a value comparable to
that used in the EA.
Although proposed standards are generally not listed in an EA, an
exception in this EA was made for lead. This decision was made
because the chemical is being reclassified from a threshold to a
non-threshold chemical. Given the high toxicity of lead and this
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reclassification, EPA believes that the use of the current Maximum
Contaminant Level (threshold) or threshold goal would underestimate
the potential risk from lead.
21. The PRPs also objected to the incorporation of data from the
permitted landfill into the EA because it was outside the scope of
investigation for the RI/FS. However, the PRPs believe that the data
indicate that all off-site exposures and risks are attributable to
the landfill and not the unpermitted drum disposal area.
EPA Response: Data from the permitted landfill allowed for some
separation of the landfill effects oh surface water and sediment
concentrations from the unpermitted drum disposal area effects.
While some chemicals migrating off site were related to the permitted
landfill, others are, or may be, related to the unpermitted disposal
areas.
22. The PRPs believe that EPA failed to properly consider background
concentrations.
EPA Response: In cases where site-specific background data are
available, these data are preferred over data obtained from published
reports. The EA used site-specific background data where available.
Although on-site levels of arsenic do not exceed background levels,
off -site levels were statistically above background. In addition to
the health-based cleanup level for arsenic of 5 rag/kg for off-site
exposure, the FS also listed the background level of 11 rag/ kg as
cleanup guidance.
7. The PRPs believe that the. surface water volatization model used in
the EA overestimates exposure due to overestimation of the area of
release, miscalculation of the flux rate, and overestimation of the
breathing rate .
EPA Reosonse: EPA believes that the model is appropriate . The area
for release from surface water was taken as the area from which
surface water samples had been collected on site. This .is the total
area available for release of contaminants. The assertion that both
the flux rate and the emission rate were multiplied by the area is
incorrect. The -flux rate is multiplied by the area then divided by
the volume of the air dispersion box to obtain the air concentration.
The breathing rate used in assessing exposure was 2.8 m3/hr which
is given by Anderson et al. (1985) as the breathing rate for adults
engaged in moderate activity. This cannot be converted to 67.2
m^/day, since breathing rates will be less during sleeping and
other parts of the day. -
24. The FRPs have suggested that a future-use scenario involving a
resident on Elite is unrealistic.
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EPA Response: Although such a scenario may be unlikely, it cannot be
precluded as a possibility. Ground water is used by several area
residents, Indicating that the use of a well by an on-site resident
is also a possibility. The future use scenario is consistent with
the evaluation of a truly no-action alternative where no restrictions
on site usage occur. EPA considers such a scenario for comparing a
no-action alternative to site remediation and/or institutional
controls.
25. The PRPs have produced their own endangerment assessment, using
certain data collected in the Remedial Investigation; this assessment
presents different conclusions than the EA prepared as a part of the
Smith's Farm RI/PS.
EPA Responset The alternative assessment produced by the PRPs has
relied on arbitrary rejection of valid data, use of less than
conservative exposure assumptions, misinterpretation of toxicity
data, and selective reading of EPA guidance documents to make its
conclusions. EPA believes that while assumptions and value
judgements based on limited data are a part of any risk assessment,
the PRPs EA document is not a truly valid representation of risks
associated with the Smith's Farm site.
26. The PRPs submitted several comments that refer to the selection
of remedial action at the site. As an introduction to this topic,
the PRPs state that EPA's selection of a preferred remedy for the
Smith's Farm site is premature, inconsistent with the statutory and
regulatory requirements of the Superfund Amendments and
Reauthorization Act (SARA) and the National Contingency Plan (NCP),
and is arbitrary and capficious. The PRPs further state that EPA has
misconstrued and misapplied the balancing of factors required by
Section 121 of SARA and by the NCP. The PRPs have concluded that EPA
does hot have sufficient information to select a remedy for the
unpermitted drum disposal areas and have expressed a preference for
Alternative 2, as identified in the Feasibility Study, over the
.selected remedial action, Alternative 4.
EPA Responset EPA responds to the introductory remarks summarized
above by stating that the proposed plan is consistent with all
statutory and regulatory: requirements of SARA and the NCP; will meet
all Applicable or Relevant and Appropriate Requirements as. required
by the Comprehensive Environmental Response, Compensation and
Liability Act of 1980 (CERCLA) as amended by SARA, CERCLA Section
121(d); was selected after balancing the factors required by CERCLA
Section 121; and is protective of human health and the environment.
EPA believes that the remedial action was selected using sufficient
and reliable data as presented in the RI and EA reports. Much of the
PRPs disagreement with the Proposed Plan hinges on their assertion
that there is insufficient data presented in the RZ report and that
the EA report presents a flawed assessment of the site risks.
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27. The PRPs argue that cost as a selection factor was not properly
considered in the selection of remedy.
EPA Responset In the Feasibility Study, five remedial alternatives
that could be applied to the unpermitted drum disposal site were
subjected to a detailed analysis. The alternatives have an estimated
cost ranging from approximately one million dollars to an alternative
that is projected to cost over four hundred million dollars. The
least costly "no action" alternative would not be protective of human
health and the environment and thus was not a reasonable alternative
to select. Alternative 5/ the most costly remedy requiring off-site
waste incineration and disposal, would have provided no additional
environmental protection to the area compared to the three remaining
alternatives, provided that the other alternatives are designed,
implemented, and maintained as specified in the FS. Furthermore,
off-site dispsoal is not to be favored where practicable treatment
technologies are available (CERCLA Section 121 (b)(l). Of the three
remaining alternatives, Alternative 3, which provides for the
treatment of all wastes from Area A and Area B, most closely complies
with CERCLA Section 121 (b)(l) concerning the permanent and
significant reduction of the volume, toxicity or mobility of
contaminants; the long-term uncertainties associated with land
disposal; and the preference for utilizing treatment technology as a
part of the remedial action. Alternative 2 more closely complies
with the cost-effectiveness provisions of CERCLA Section 121 than the
other alternatives but does not provide for any treatment and does
nothing to reduce the toxicity or volume of contaminants.
Alternative 4 does provide for some treatment, and will result in a
reduction in the^volume, mobility, and toxicity of contaminants at a
cost less than oil third the cost of Alternative 3. EPA selected
Alternative 4 over Alternatives 2 or 3 because it strikes a balance
between the several important considerations listed in CERCLA Section
121 (b). .
28. The PRPs believe that the selection of remedy was made using
inadequate information to properly characterize the nature and extent
of the waste and its effects on human health and the environment.
They disagree with the use of a "worst-case scenario" in the risk
assessment, the use of estimated concentrations in environmental data
evaluation, the use of certain health criteria in the risk
assessment,, the-use of site-specific background data in preference to
published data representing background concentrations, and the method
of analysis to define the surface water exposure route.
EPA Responsei EPA has determined the following concerning the
unpermitted drum disposal areas at the Smith's Farm sites
(1) The areal extent and approximate volume of contaminated materials
(including soil) in the unpermitted drum disposal areas.
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(2). The concentrations and distributions of organic and inorganic
contaminants of concern in the soil, shallow ground water, and
surface water and stream sediments in the unpermitted drum disposal
study area and extending off site.
(3) The risks associated with the contamination from the unpermitted
disposal areas, both for an "average case" and "plausible maximum
case" (worst case) scenario.
EPA believes that inclusion of a "worst-case scenario" for risks is
justified. This conclusion is based upon both the need to consider
such and the inherent uncertainties in estimating risks at any site
because of the limitations on sample size, seasonal variability of
data, and so forth.
As stated previously, the use of estimated concentrations in
environmental data analysis is justified, provided that the data is
treated properly. Published data on background concentrations of
naturally occurring substances in soil or other environmental media
are generally used in environmental analysis only when no site-
specific data are available. For the Smith's Farm RI, available
site-specific data were used in preference to published data.
The methods, assumptions, references and data used in the
environmental risk Assessment (Endangerment Assessment Report) are
completely documented in the report. Contrary to the conclusion of
the PRPs, EPA believes that the risks portrayed in the report are
plausible. The EPA has portrayed the risks from the Smith's Farm
site as no more or less than what the RI and EA reports have
indicated might be associated with the site.
Concerning the issue of the adequacy of site characterizations
sufficient to justify the selection of remedial action, the PRPs have
cited various parts of the the FS to support their contention that
inadequate data were collected. These citations are in part either a
selective presentation of what appears in the FS report, or are taken
out of context. In several instances, the Remedial Investigation
relied on non-intrusive, inferential methods to evaluate waste
disposal area conditions rather than using much more costly and
hazardous direct sampling techniques. EPA believes that combined
with the environmental sample data that were collected for the RI, as
well as previously collected data that were considered, these
inferential data were both adequate for estimating the nature and
extent of contaminated areas for the purpose of selecting a remedial
alternative and were preferable to intrusive sampling on the basis of
cost and risk compared to benefit.
As EPA has acknowledged, there is some uncertainty as to the exact
nature and extent of material in Area A. EPA therefore has a
flexibility in the Record of Decision so that EPA can evaluate the
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exact amount of Area A material to be incinerated. This flexibility
would allow for the incineration of some additional material in
addition to the small amount expected to be incinerated if it could
be done in a cost-effective fashion. Because the remedial action
will involve the movement of contaminated materials in Area A in any
of the options under consideration (capping or incineration), it is
reasonable to conduct a minimal amount of intrusive investigation at
that time to more fully characterize Area A. EPA has selected a
remedial action that has a possibility of achieving slightly more
reduction of contaminant toxicity, volume and mobility than what is
anticipated to occur if the incineration and solidification/fixation
of additional materials in Area A should be determined to be cost
effective.
A comment by the same PRPs regarding the draft workplan for the
Remedial Investigation was that the proposed sampling plan included
too many samples. Their present assertion that more data should be
collected before the remedial action is selected is inconsistent with
this earlier opinion.
29. The PRPs believe that remedial action of the permitted landfill
should be combined with remedial action dealing with the unpermitted
drum disposal areas.
«
.EPA Responses This issue was previously addressed in the EPA response)
to a comment by the Kentucky Resources Council. It is important to
reaffirm that delaying remediation of the unpermitted disposal area
and then combining remediation of that area with the remediation of
the permitted landfill would both delay addressing the threat to
human health and the environment posed by the unpermitted drum
disposal area and would result in a greater cost of remediation for
unpermitted drum disposal area because of the need to excavate, treat
and transport the entire volume of the waste. EPA cannot justify
this option if it is no more protective of human health and the
environment than Alternative 4 and will cost almost $100 million to
implement.
Section 4. Remaining Concerns
The major concerns expressed concerning the remedial design and
remedial action Have been addressed in Section 3 of the
Responsiveness Summary. One citizen expressed an interest in the EPA
Technical Assistance Grant program at the public meeting. This
individual was given some information about the. program and was told
to contact the EPA Community Relations Coordinator for additional
information.
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