United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROO/R07-88/015
September 1988
Superfund
Record of Decision;
Times Beach, MO
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502n -101
REPORT DOCUMENTATION /1. REPORT NO.
PAGE EPA/ROD/R07-BB/015
z.
3. Recipient's Acc:"alon No.
4. Tltl. and Subtitle
SUPERFUND RECORD
Times Beach, MO
~econd Remedial
IAuthOr(S)
OF DECISION
So Re~'} ~~i B B
I.
Action
I. Parformln. O,.anlzatlon Rept. No.
r9. Perform'n. O,.anlutton Nsme and Addre..
10. ProJect/Task/Work Unit No.
j
-
--
11. Contract(C) or Grant(G) No.
eC)
(G)
12. Sponsorin. Orllanlutlon Name and Address
U.S. Environmental Protection
401 M Street, S.W.
Washington, D.C. 20460
13. Type 0' Report & Period Covered
--
Agency
800/000
14.
15. Supplementary Notes
.
II. Abstr8Ct (limit: 200 words)
The Times Beach site is a 0.8 square-mile area located in the formerly incorporated
city of Times Beach, St. Louis County, Missouri, approximately 20 miles southwest of the
city of St. Louis. The'site is bordered on the north and east by the Meramec River and
areas of St. Louis County, on the south by areas of Jefferson County~ and on the west by
the City of Eureka. Land use of the surrounding areas is primarily residental and
agricultural. The majority of the site falls within the five-year flood plain and the
g~tire site falls within the 25-year flood plain of the Meramec River. The soil
Itamination at the site is a result of spraying roads for dust control in the 1970s
.th oil that was contaminated with dioxin. Investigations indicate that the
contamination is limited to the roads, road shoulders, and drainage ditches along the
roads and is generally limited to the top twelve inches of the soil. Approximately
13,600 cubic yards of soil at concentrations above 20 ppb dioxin as well as 105,000
cubic yards of structures and debris are estimated to be contaminated. No detectable
levels of dioxin have been found in the ground water or surface water at the site thus
far. Based on the analytical results of soil samples collected in 1982 and on an
advisory from the Centers for Disease Control, EPA determined that all residents and
businesses should be relocated. In February 1983, EPA transferred CERCLA funds to the
(See Attached Sheet)
17. Document Analysis a. Descriptors
Record of Decision
Times Beach, MO
Second Remedial Action
Contaminated Media: soil
Kev ronraminants' dioxin
RI. IcJ'.."tifiit"[tJpen.EnCfed' Terms
c. COSATI Field/Group
II. Availability Statement
19. Security Class (This Report)
None
1----'
20. Security Class (This Page)
None
21. No. 0' Palles
282
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22. Price
(See ANSI-Z39.18)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTI5-3S)
Department 0' Commerce
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EPA/ROD/R07-88/01S
Times Beach, MO
Second Remedial Action
16.
ABSTRACT (continued)
Federal Emergency Management Agency to conduct relocation activities. The primary
contaminant of concern affecting the soil at this site is 2,3,7,8-TCDD (dioxin).
The selected remedial action for the site includes: demolition and onsite disposal
of all structures and debris remaining at the site; excavation of dioxin-contaminated
soil exceeding 20 ppb and thermal treatment in a temporary onsite thermal treatment unit
with onsite disposal of 'incinerator ash; placing of clean soil cover and revegetation
over all areas with residual dioxin levels between 1 and 20 ppb; construction of a ring
levee surrounding the temporary thermal treatment unit for flood protection; interim
storage of excavated soil onsite pending availability of the thermal treatment unit; and
implementation of erosion controls. The estim?ted total capital cost for this remedial
action is $48,800,000, which includes all costs from the Minker/Stout/Romaine Creek site.
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IV.
SCOPE AND ROLB OF RBSPONSE ACTION
EPA is seeking a cost-effective overall remedy for the
dioxin-contaminated sites in eastern Missouri (See Table 1).
The decisions made now for Times Beach and M/S/RC can affect the
range of alternatives that will be available for the other
eastern Missouri dioxin sites listed in Table 1. Alternatives
for later actions, if such action is determined by EPA to be
necessary at the other sites, may. involve thermal treatment at
Times Beach. The decision made now for Times Beach will have a
direct impact on the availability of treatment or management
capacity at Times Beach for these other sites.
In order to ensure that the remedy selected for Times Beach
and M/S/RC is consistent with an overall cost-effective remedy,
EPA must consider the potential need for remedies at all of these
sites in its evaluation of alternatives for Times Beach and
M/S/RC. In the cost-effectiveness analysis especially, EPA must
not evaluate alternatives for these two sites in isolation, but
must evaluate costs in the context of an overall solution.
Selection of the least costly alternative for Times Beach and
M/S/RC now may result in higher overall costs later.
For the purpose of evaluating alternatives for Times Beach
and M/S/RC, EPA has had to. make some assumptions about the remedy
that will most likely be selected for at least. some of the other
sites. On the basis of the best available information and more,
than five yearg of experience with the dioxin problem, EPA has
concluded that offsite treatment or disposal is the remedy most
likely to be selected for the other sites, if action is
determined to be necessary by EPA. These alternatives were
included in the analysis presented in the Proposed Plan.
The remedy selected in this-Record of Decision assumes th~t
either offsite thermal treatment or disposal will be selected and
implemented for the other sites, and. the cost-effectiveness
analysis evaluates the alternatives for Times Beach and M/S/RC in
that context.
The selected remedy also includes final disposal for
the existing structures at Times Beach. Alternatives evaluated
for this material were developed and evaluated in the Times Beach
Feasibility study. The feasibility study estimated that 105,000
cubic yards of structures and debris exist a~ Times Beach.
It is the intent of EPA to prioritize the disposal of the
structures and debris at Times Beach. Demolition and disposal of
the structures and debris could begin as soon as the disposal
facility is designed and constructed. structures and debris
would initially be removed from the uncontaminated portions of
Times Beach, which include areas most visible from Interstate
44.
The only dioxin sites being considered for potential thermal
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action for the MjSjRC site began with the public release of the
Feasibilitv Studv of Final Remedial Actions for the
Minker/Stout/Romaine Creek site in July 1986. This study
evaluated remedial alternatives for the dioxin-contaminated soil
being temporarily stored at the site, located approximately ten
miles south of Times Beach. Remedial alternatives evaluated in
this study are similar to those evaluated in the Times Beach
Feasibilitv study, with the addition of disposal in underground
mines and thermal treatment at a permitted commercial facility.
One option evaluated consisted of 'offsite thermal treatment at a
nearby centralized facility within 50 miles of the
MinkerjStoutjRomaine Creek site.
A public comment period was held from August 8, 1986,
through september 5, 1986, for the Feasibilitv study of Final
Remedial Actions for the Minker/Stout/Romaine Creek Site. A
public meeting was held August 25, 1986, to discuss the
alternatives evaluated in the study and the Agency's proposed
remedy.
The public was first invited to comment on the concept of a
comprehensive solution for all of the eastern Missouri dioxin
sites at the public meeting for the M/SjRC feasibility study. At
that meeting, it was announced that the State of Missouri had
recommended evaluation of Times Beach as a location for siting a
temporary thermal treatment unit and that EPA was evaluating this
possibility. A feasibility study to evaluate Times Beach as a
potential location for thermal treatment was to be completed and
released for public comment. '.
The Times Beach Feasibilitv Studv was released for public
comment from December 29, 1986, through March 27, 1987. A public
meeting was held on February 12, 1987, to discuss alternatives
evaluated. in the study and to present the Agency's proposed
remedy. During the meeting, the public was told that EPA may
determine that dioxin cleanup levels higher than 1 ppb could be
acceptable for non-residential settings, as discussed in the
Times Beach Feasibilitv Studv, if they were acceptable to state
and Federal health authorities.
The Times Beach and MjSjRC Proposed Plan was released
February 19, 1988. A public comment period was held from
February 19 through March 18, 1988, and a public meeting was held
in Eureka, Missouri March 10. The proposed plan recommended
centralized thermal treatment of contaminated soils at Times
Beach and the MjSjRC site at a temporary thermal treatment
facility to be located at Times Beach. The Proposed Plan.
specified an action level for Times Beach of 20 ppb, and included
a one-foot soil cover in areas exceeding 1 ppb.
All decision documents and responsiveness summaries are
included in the Administrative Record and can be referred to for
additional information on public participation and response to
previous activities.
. ~
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The contamination at Times Beach resulted from spraying
roads for dust control in the 1970s with oil that was
contaminated with dioxin. Initial soil samples were collected by
EPA in 1982. In February 1983,- on the basis of an advisory from
the Centers for Disease Control (CDC), EPA transferred $33
million, under authority of the Comprehensive Environmental
Response, compensation, and Liability Act (CERCLA), to the
Federal Emergency Management Agency (FEMA) to permanently
relocate Times-Beach residents and businesses.
Additional information about the sites, the history of their
contamination, and the investigations that EPA has conducted is
presented in the feasibility studies and other documents in the
-Administrative Record.
The potentially responsible parties (PRPs) for these sites
include the generators of the dioxin waste, the transporter and
sprayer of the waste, and those who arranged for the transport
and spraying of the waste.
In November 1984, an administrative order was issued to The
Charter Company, Charter International oil Company, Charter Oil
Company and Independent Petrochemical Corporation pursuant to
Section 106 of CERCLA for the Times Beach site and for the
Minker/Stout/Romaine Creek site. Each order required the named
respondents to implement a remedial investigation and feasibility
study and, after approval by EPA, to implement remedial design
and remedial action for each site. These corporations had filed
for reorganization pursuant to Chapter 11 of the "Bankruptcy Code
April 19, -1984. .
In addition to the above orders, EPA also filed a proof of
claim in the bankruptcy proceeding relating to costs incurred at
the Times Beach and the Minker/stout/Romaine Creek site. In
January 1987, EPA entered into a consent decree with The Charter
Company, Charter International Oil Company and Charter Oil
Company in settlement of all claims of the united States against
those companies relating to the presence of dioxin at the Times
Beach site,- the Minker/Stout/Romaine Creek site and other sites.
Subsequent to the entry of this consent decree, The Charter
Company, Charter International Oil Company and Charter Oil
Company were dismissed as respondents in the administrative
orders.
Special Notice letters were issued to three Syntex entities
and to Independent Petrochemical Corporation March 31, 1988. The
moratorium required by Section 122(e) of the Superfund Amendments
and Reauthorization Act (SARA) began on the date of issuance of
this notice.
III.
COMMUNITY RELATIONS HISTORY
Public participation in the selection of a final remedial
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I.
SITB NAME, LOCATION, AND DBSCRIPTION
This Record of
dioxin-contaminated
Beach site in Times
Creek site (M/S/RC)
Decision presents the final remedy for
soils at two Superfund sites: the Times
Beach, Missouri, and the MinkerjStoutjRomaine
in Imperial, Missouri.
Times Beach was formerly an incorporated city in southwest
.st. Louis County, approximately 20 miles southwest of the City of
st. Louis. The site encompasses approximately 0.8 square miles,
bordered on the north and east by unincorporated areas of St.
Louis County, on the south by unincorporated areas of Jefferson
County, and on the west by the City of Eureka. The City of Times
Beach was disincorporated in 1985.
On the north and east, the site is contiguous to the Meramec
River, the dominant hydrological feature in the area. The site
is bisected at the southern end by Interstate 44. Burlington
Northern Railroad lines are adjacent to Times Beach to the west.
Much of the site is located in the five-year flood plain, and the
entire site is within the 25-year floodplain. The area's
topography is level to slightly sloping, with an average slope of'
less than one percent. Residential development has historically
constituted the major land use. Commercial land use has been
minimal, and the city has had no industrial development. The
surrounding areas have a mixture of residential and agricultural
uses. Agricultural usage consists of cropland; no areas in close
proximity to Times Beach are used for grazing.
The Minker/Stout/Romaine Creek site (M/SjRC) is in an
unincorporated, residential area approximately 25 miles southwest
of st. Louis. The area is generally wooded, with steep hillsides
and thin soil. This site includes four non-contiguous areas
(Minker, stout, Cashel, and Sullins) within a distance of
approximately 0.8 miles, and the upper 6,000 feet of Romaine
Creek, which originates at the Minker area.
II.
SITB HISTORY ~ ENFORCEMENT ACTIVITIES
Over 1,000 soil samples collected from Times Beach, and a
similar number from the MjSjRC site, have been analyzed to
determine the extent of dioxin contamination.
The contamination at MjSjRC resulted from the use of dioxin-
contaminated soil as fill material. Contami~ated soils have been
excavated from all portions of the site except the stout area and
Romaine Creek and placed in interim onsite storage. The
investigations indicate that the remaining contamination is
confined to the fill placed at the stout area, and portions of
Romaine Creek to which the contaminated soil has migrated,
primarily through erosion from the Minker area. Interim remedies
are underway to excavate this remaining contaminated soil for
temporary onsite storage.
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Section
I.
II.
i
CONTENTS
SITE NAME, LOCATION, AND DESCRIPTION
SITE HISTORY AND ENFORCEMENT ACTIVITIES
III. COMMUNITY RELATIONS HISTORY
IV.
V.
VI.
VII.
SCOPE AND ROLE OF RESPONSE ACTION
SITE CHARACTERISTICS'
SUMMARY OF SITE RISKS
DOCUMENTATION OF, SIGNIFICANT CHANGES
VIII. DESCRIPTION OF ALTERNATIVES
IX.
X.
XI.
SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
THE SELECTED REMEDY
STATUTORY DETERMINATIONS
Page
1
1
2
4
6
7
12
12
15
36
42
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RECORD OF DECISION
FOR
FINAL KANAGBXENT OF
DIOXIN-CONTAMINATED SOIL AND
FINAL DISPOSITION OF STRUCTURES AND DEBRIS AT
TIMES BEACH, KISSOURI
and the
KINKER/STOUT/ROMAINE CREEK SITE, KISSOURI
prepared by
U.S. ENVIRONMENTAL PROTECTION AGENCY
september 28, 1988
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.Mobilization of a temporary transportable thermal treatment
unit to Times Beach.
.Excavation of all dioxin-contaminated soils at Times Beach
exceeding a level of concern for protection of human health and
the environment for designated non-residential land uses.
'Thermal treatment of soils excavated from Times Beach and
the Minker/Stout/Romaine Creek site.
.Delisting and onsite land disposal of treatment residue
(ash) in a facility meeting solid waste management requirements.
DECLARATION
The selected remedy is protective of human health and the
environment, attains Federal and state requirements that are
applicabl& or relevant and appropriate to this 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 (or resource
recovery) technologies to the maximum extent practicable.
Because this remedy will result in hazardous substances
remaining onsite above health-based levels for unrestricted use,
a review will be conducted within five years after the
commencement. of the remedial action to ensure that the remedy
continues to provide adeqUate protection. of human health and the
environment. .
s ~ f i~~ b~Y- ,)0 19%8
Date' .
, liX:-
~~
. Winston Porter, Ph.D.
ssistant Administrator
Office of Solid Waste and
Emergency Response
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RECORD OF DBCISION DBCLARATION
SITB NAKE AND LOCATION
°Times Beach, st. Louis County, Missouri
°Minker/stout/Romaine Creek, Jefferson County, Missouri
STATEMENT OP BASIS AND PURPOSB
This decision document presents the selected remedial action
for the Times Beach site in st. Louis County, Missouri, and the
Minker/Stout/Romaine Creek site in Jefferson County, Missouri,
developed in accordance with the Comprehensive Environmental
Response, Compensation, and Liability Act of 1980 (CERCLA), as
amended by the Superfund Amendments and Reauthorization Act of
1986 (SARA), and,. to the extent practicable, the National
Contingency Plan. This decision is based on the administrative
record for this site. The attached index identifies the items
that comprise the administrative record upon which the selection
of the remedial action is based.
DESCRIPTION OP THE SELECTED REMEDY
This remedial action represents the final action for dioxin-
contaminated soils at the Times Beach and Minker/Stout/Romaine
Creek site and final qisposition of structures and debris at
Times Beach. This remedial action addresses the principal
threats at the sites by thermal treat~ent of soils that exceed
a level of concern for the protection of human health and the
environment for designated non-residential land uses. Thermal
treatment results in the destruction of dioxin in the treated
soils, permanently removing this contamination from the
environment. The selected remedy also includes placement of a
vegetated soil cover over areas 'with contaminant levels exceeding
health-based levels for residential areas, which provides an
additional barrier for protection of human health and the
environment. .
Excavation of contaminated soils at Times Beach is included
in this remedial action. Excavation of contaminated soils from
the various portions of the Minker/Stout/Romaine Creek site has
been completed or is planned through separate operable units.
The major components of the selected remedial action
include:
°Demolition and onsite land disposal of uncontaminated
structures and debris at Times Beach in a facility meeting solid
waste disposal requirements.
.Construction of a ring levee to protect a temporary thermal
treatment unit from a lOa-year flood.
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5
TABLE 1
POTENTIAL MISSOURI DIOXIN SITES
FOR CENTRALIZED TREATMENT/DISPOSAL AT TIMES BEACH
SITE NAME
ESTIMATED
SOIL
VOLUME, CY
----------------------------------------
----------------------------------------
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1. Minker/Stout/Romaine Creek
stout Area
Romaine Creek
Minker, Minker Neighbors
Cashel Residence
Sullins Residence
2. Lac¥ Manor
3. Ell1sville Area site
4. Community Christian Church
5. Manchester Methodist Church
6. Eureka-East North street
7. Baxter Garden Center
8. Highway 141 Access Road
9. East Texas Motor Freight
10. Bull Moose Tube
11. Hamill Transfer
12. Jones Truck Lines
13. Overnite Transport*
14. Southern Cross Lumber
15. Times Beach
16. Arkansas Best Freight*
17. Bo~ifield Brothers Trucking
18. Timberline Stables
19. Bubbling Springs Arena
20. Saddle and Spur Arena
21. Shenandoah Stables
22. Piazza Road
23. Frontenac Tank site
24. Castlewood
25. Quail Run
26. Bristol Steel
1,900
4,300
4,400
400
1,000
600
7,000
550
300
750
1,500
620
1000
300
1,800
1,000
1,300
13, '600
2,100
1,600
2,780
2,550
3,300
7,800
750
12,900
16,000
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TOTAL
92,100
----------------------------------------
----------------------------------------
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* Dioxin levels detected to date below level of concern
for occupational exposure. Levels to be verified.
f,
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treatment at Times Beach are listed in Table 1. These are the
sites which became contaminated as a result of application of
waste oil by the Bliss Waste Oil Company in the early 1970s.
The waste oil contained dioxin wastes from a chemical plant
in southwest Missouri. All of these sites are in eastern
Missouri. The Agency will limit the potential sources of
material to be thermally treated at Times Beach to these twenty-
six (26) sites. Inclusion in the list does not imply that the
Agency has decided to take action at the sites. Each site other
than Times Beach and Mi~ker/Stout/Romaine Creek will be evaluated
individually, and the decision made based upon the threat to
public health and the environment presented at the site. The
Agency estimates that thermal treatment of the material from the
twenty-six (26) sites identified in Table 1 could be completed
within six (6) years after receipt of the RCRA permit. This
project period is based upon a thermal treatment rate of
approximately 100 cubic yards of soil per day. The assumptions
associated with this treatment are discussed in Section IX (page
29 below). Upon completion of treatment of materials from the
designated twenty-six sites, the thermal treatment unit would be
disassembled and permanently removed from Times Beach.
A RCRA Part B permit will be required for thermal treatment of
materials transported to Times Beach~ The RCRA permit is issued
by the State of Missouri. Public participation is an important
consideration in the permitting process. RCRA permits may be
issued for periods not to exceed ten (10) years according to
Federal regulations (40 CFR 270.50). The Agency will request a
permit for the th~rmal treatment unit for six (6) years.
v.
SITB CHARACTBRISTICS
The investigations at Times Beach indicate that the
con~amination is limited to the roads, road shoulders, and
drainage ditches along the roads, and that the contamination is
generally limited to the top twelve inches of the soil.
Concentrations of dioxin greater than 20 parts per billion (ppb)
have been detected on approximately 15,000 feet of roadways, and
dioxin levels exceeding 100 ppb have been detected on
approximately 7,000 feet of roadways.
Soil volume estimates baseQ on the most recent sampling at
Times Beach indicate that approximately 13,600 cubic yards of
soil is contaminated at levels above 20 ppb. The sampling used
to develop this estimate was carried out according to a
statistically-based method that allows calculation of the maximum
average expected dioxin level within a sampling area to the 95th
percentile upper confidence limit.
Samples analyzed for dioxin have indicated that the air,
ground water, surface water, river sediments, and finished
drinking water taken from the river downstream of Times Beach are
not contaminated with dioxin.
Contaminated soils from the Minker, Cashel, and Sullins
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areas of M/S/RC have been removed and placed in temporary
storage facilities on site. Actions are being taken to excavate
the remaining contaminated soil at the Stout and Romaine Creek
areas for placement in tempora~y storage.
A number of potential pathways exist for dioxin to come into
contact with human receptors or sensitive environmental areas.
Human exposure to dioxin can occur as a result of ingestion,
. inhalation, or .direct contact. Ingestion of dioxin could result
from the consumption of contaminated water, soil, fish, or other
plant or animal material. Ingestion of dioxin-contaminated water
is not thought to be a problem at either M/S/RC or Times Beach
because no ground water or surface water samples have shown
detectable levels of dioxin except during storm events, and
dioxin has a very low solubility in water. Also, dioxin is
highly adsorptive to soil particles, and migration into the
ground water is considered unlikely. Sediment transport with
stormwater runoff, particularly during flood events, represents
the primary mechanism by which dioxin could enter the Meramec
River.
Almost 150,000 square yards (30 acres) of roadway and
shoulder surface area are estimated to be contaminated at levels
greater than 1 ppb at Times Beach. There does exist a limited
potential for surface contamination to reach the river by
trahsport during rainfall events, particularly during periods of
flooding at Times Beach~ The potential. for suspended
contaminated sediment to reach the Meramec during normal Meramec
River flow conditions is much 'lower since most of the site is
depositional in nature and the high river banks generally .retain
the stormwater within Times Beach. Stormwater is retained on the
site until it is absorbed into the ground. In addition, the
majority of the dioxin contamination is located beneath roadway
pavement, which prevents its erosion. The high river banks also
control the quantity of dioxin-contaminated 'suspended sediment
that could be transported to.the Meramec River as floodwaters
recede. Significant contaminant levels have not been detected in
yards and other off-road areas following flooding.
VI.
SUHMARY OF SITB RISKS
contaminants Q! Concern
The contaminant of concern at both sites is 2,3,7,8-TCDD,
commonly referred to as dioxin.. Dioxin is considered one of the
most toxic compounds known, with the lowest LD-50 (lethal dosage
for 50% of the subjects exposed) level for male guinea pigs, the
most sensitive species, being only 0.6 micrograms per kilogram
(ug/kg) .
Although dioxin has been highly toxic in all species tested,
there are large ~pecies differences in sensitivity, with the LD-
50 for hamsters being 1,157 to 5,051 ug/kg. The characteristic
1
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signs and symptoms of lethal dioxin poisoning in laboratory
animals are severe weight loss and thymic atrophy. Death usually
occurs many days after exposure. After subchronic or chronic
exposure to dioxin in rats or mice, the liver appears to be the
most severely affec~ed organ, although systemic hemorrhage, edema
(excess fluid accumulation), arid suppressed thymic (immune
system) activity are also observed.
Animal studies have also demonstrated that dioxin is
teratogenic (causes malformities) and fetotoxic (toxic to fetus)
in mice, rats, rabbits, and ferrets and is fetotoxic in monkeys.
Because dioxin produced a statistically significant increased
incidence of tumors in two animal species, there is sufficient
evidence to conclude that dioxin is an animal carcinogen. In
fact, dioxin is the most potent animal carcinogen evaluated to
date by the EPA Carcinogen Assessment Group. For comparison,
dioxin is about 50 times as potent as the third most potent
animal carcinogen evaluated (bis-chloromethyl ether) and about 50
million times more potent than vinyl chloride (a widely known
carcinogenic substance).
study results concerning humans that have been exposed to
herbicides and other chlorinated chemicals containing dioxin as a
contaminant indicate that excessive exposure leads to altered
liver function, lipid metabolism, and neurotoxicity. In
addition, humans may develop the skin lesions chloracne and
hyperpigmentation.
The available epidemiologic' evidence concerning the
carcinogenicity of dioxin in humans is inadequate. Considering
the available animal carcinogenic and epidemiologic d~ta,
however, the overall weight-of-evidence classification for dioxin
(using EPA's interim classification scheme) is category B2, a
probable human carcinogen. .
Polychlorinated dibenzo-p~dioxins are a class of chlorinated
tricyclic aromatic hydrocarbons consisting of two benzene rings
connected by a pair of oxygen atoms. According to the position
and number of chlorine atoms, it is possible to form 75 different
types of chlorinated dioxins. The word "dioxins" is often used
to refer to this class of compounds, especially with respect to
the highly toxic 2,3,7,a-tetrachlorodibenzo-p-dioxin that is
present at Times Beach. This class of compounds is stable toward
heat, acids, and alkalis. They are also chemically stable and
start to decompose only at temperatures greater than 500 degrees
C. The percent of decomposition depends upon the residence time
at high temperature and the proportion of oxygen in the heated
zone. .
Physico-chemical properties suggest that dioxin will adsorb
tightly to organic material in soil, resulting in low mobility.
Once in the soil, degradation processes tend to be very slow,
with half lives estimated to be ten years or longer.
Calculated and experimental results show that dioxin will
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concentrate in biota present in aquatic media. Reported
bioconcentration factors of dioxin in fish range from about 2,000
to 30,000. In mammals, dioxin is readily absorbed through the
gastrointestinal tract. Absorption through intact skin has also
been reported. Absorption may decrease dramatically if dioxin is
adsorbed to particulate matter such as activated carbon or soil.
After absorption, dioxin is distributed to tissues high in lipid
(fat) content; however, in many species the liver is a major
storage location. Metabolism of dioxin occurs slowly, with
metabolized TCDD excreted in the urine and feces. Unmetabolized
dioxin can be eliminated in the feces and in the milk.
Risks to Human Health and the Environment
continued long-term direct contact with or ingestion of
soils would present the greatest threat to human health. This
exposure potential for humans has been limited in the short term
at Times Beach by controlling site access. Ingestion of dioxin
by wildlife could occur in the event that dioxin entered the
Meramec River and was ingested by fish or by direct ingestion of
Times Beach soils. Wildlife onsite are susceptible to becoming
contaminated as there are no controls to prevent animals from
entering the site.
Inhalation of dioxin-contaminated airborne particulates
presents a potential route of human exposure primarily for
workers during periods of onsite construction ~ctivities
involving disturbance of contaminated soils. Mitigative measures
exist to control this risk.
Ingestion of plant~ 'grown in contaminated soil represents a
potential exposure. route, although there is uncertainty regarding
the potential for uptake of dioxin in plant life. Dioxin uptake
in many plants appears to be minimal. This potential pathway is
currently controlled by restricting site access. Land use'
restrictions represent another effective means of controlling
this exposure potential, although potential uptake in plants
would be unaffected.
The most serious environmental problem which could be
expected at Times Beach is the transport of dioxin to the Meramec
River due to erosion of surficial soils. The current threat to
human health and the environment due to bioaccumulation in fish
as a result of the release of dioxin from Times Beach into the
Meramec River appears to be insignificant. Although fish in the
Meramec River have shown detectable levels of dioxin, contaminant
levels have been below the advisory level of 50 parts per
trillion (ppt) designated by the Food and Drug Administration for
unrestricted consumption of fish from the Great Lakes. The data
collected to date indicate that dioxin contamination in the
Meramec River is primarily a result of other sources downstream
of Times Beach.
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~ Assessment
A paper was published in 1984 by Renate D. Kimbrough, M.D.,
et al., of the Center for Environmental Health, Centers for
Disease Control, which evaluated acceptable soil concentrations
of dioxin in residential settings. A risk assessment was
performed in this paper on the basis of several chronic feeding
studies in rodents. The smallest lower confidence bound for the
average lifetime daily dosage corresponding to a 1 x 10-6
incremental cancer risk was calcuiated to be 28 femtograms per
kilogram body weight per day (f9/kg b.w./day). This calculation
was based on data for hepatocellular carcinoma (liver cancer) and
neoplastic nodules. This means .that a lifetime average dosage of
28 fg/kg b.w./day would be expected to result in one additional'
case of this particular type of cancer for each million
individuals so exposed. This level is based upon a number of
conservative assumptions, as discussed in the 1984 paper. Cancer
in other types of body tissues would occur at higher dosages. On'
the basis of data for tissues less sensitive than the liver, the
paper reported that an incremental cancer risk of 1 x 10-6 would
be expected to occur at a lifetime dosage level of 1,428 fg/kg
b.w./day. Due to the number of con?ervative assumptions upon
which the daily dosage was estimated, and the substantial range
in dosages calculated to result in incremental incidences of
cancer, the paper concluded that residential soil levels greater
than 1 ppb dioxin pose a level of concern for public health. The
paper also concluded that dioxin levels other than 1 ppb may be
acceptable in certain non-residential settings.
Intake levels for residential exposure were calculated in
the 1984 study by. Kimbrough, et al., for dermal (skin), ingestion
and inhalation exposure pathways. In residential settings, the'
principal exposure pathway is through ingestion of contaminated
soil. Ingestion of soil by children is of particular concern in
residential areas. Small children may consume soi~ directly
during play. Inadvertent ingestion of soil by both children and
adults can also occur. The study estimated the average lifetime
daily dosage resulting from exposure to 1 ppb dioxin in a
residential setting, occurring primarily through ingestion, to be
636.5 fg/kg b.w./day. This recommendation formed the basis for
the criteria of 1 ppb dioxin which has been applied during the
cleanup of all residential sites in Missouri to date.
Subsequent to the 1984 health assessment, the Center for
Environmental Health, Centers for Disease Control, has continued
to evaluate acceptable dioxin levels in residential and non-
residential settings. In May 8, 1987 correspondence, the Center
for Environmental Health recommended that residential sites
contaminated with dioxin be cleaned up to a residual
concentration of 1 ppb at the surface or to a residual
concentration of 5 to 10 ppb at a depth of one foot or greater
and backfilled to original grade with clean soil. The upper foot
of clean material serves as a barrier restricting human access
from contact with the contaminated soil. In the event that the
contaminated soil is disturbed, the resulting surface
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concentration would remain below a level of concern for
residential settings. This recommendation is based upon
assumptions made in the 1984 study by Kimbrough, et al.
Dioxin cleanup levels have been established for different
media during cleanup of other Missouri dioxin sites. A cleanup
level of 4 picograms per square meter (pg/m2) has been
recommended for interior surfaces by CDC. The action level for
dioxin in water is limited by the detection limit, which by
current methods is approximately 1 ppt. A level of 3.0 picograms
per cubic meter (pg/m3) representing the average of 14 data
points collected at 24-hour intervals has been used as a level of
concern for airborne dioxin levels during the cleanup of other
eastern Missouri dioxin sites.
The 1984 Kimbrough study recommended that risk management
decisions by EPA should be based upon a consideration of the
specific circumstances and exposure opportunity at each
contaminated site. The paper noted that in certain non-
residential areas, higher levels may present an acceptable degree
of protection of human health. Conversely, soil levels less than
1 ppb dioxin may be of concern in areas used for certain
agricultural purposes.
Potential exposure in non-residential areas, in addition to
being less frequent and of shorter duration, occurs through
different-primary pathways than in residential settings. While
ingestion is the principal exposure pathway of concern in
. residential settings due to the potential for regular contact by
small children who may consume substantial quantities of soil, in
certain non-residential areas tnere is less opportunity for this
type of regular exposure by small children to occur. In
commercial or industrial settings where occupational exposure
occurs, direct contact is the primary pathway of concern. The
acceptable dioxin soil level is controlled in these non-
residential settings by limiting the potential for such contact
to occur. -
The Centers for Disease Control (CDC) has directed
correspondence to EPA containing supplemental information to the
1984 paper by Kimbrough et al. (Attachment 1). The CDC advisory
concludes that the average lifetime daily dosage in a commercial
setting with 20 ppb dioxin present on 10 percent of the site is
approximately 33 fg/kg b.w./day. This calculated dosage is below
the average daily dose estimated to be of concern for public
health in the 1984 study by Kimbrough et al. . In addition, this
dosage is substantially below the estimated dosage corresponding
to residential exposure to 1 ppb dioxin (636.5 fg/kg b.w./day). -
EPA has therefore concluded that certain types of non-residential
exposure to soil contaminated at 20 ppb dioxin is below a level
of concern for public health. The EPA, in consultation with CDC,
has concluded that a remedial action at Times Beach resulting in
removal of soils exceeding 20 ppb and covering remaining areas
exceeding 1 ppb with clean soil will reduce the risk associated
with non-residential land usage, such as a park, green space, or
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commercial area, to an acceptable level.
VII.
DOCUMENTATION OF SIGNIFICANT CHANGES
The EPA has selected a remedy consisting of centralized
treatment of dioxin-contaminated soil at Times Beach. This
selected remedy is identical to the remedy proposed in the
Proposed Plan of February 19, 1988.
VIII.
DESCRIPTION OF ALTBRNATIVES
Alternatives were evaluated to satisfy a permanent remedy at
both Times Beach and MjSjRC (especially for the cost-
effectiveness criterion) in the context of the most likely
overall solution for the potential dioxin sites in eastern
Missouri listed in this document. Therefore, all of the
alternatives included final remedial actions assumed for the
contaminated soil from the other sites. On the basis of
available information, EPA believes the most likely alternatives
to be chosen for MjSjRC and the other sites is either offsite
treatment or disposal. All of the alternatives assume that the
remedy chosen for the sites other than Times Beach will be either
offsite treatment or disposal. Alternatives 1 through 4 assume
offsite thermal treatment, and Alternative 5 assumes offsite land
disposal. The alternatives that are evaluated are:
Alternative ~
" RCRA " (Resource Conservation and -Recovery'Act) equivalent
cap over the contaminated areas exceeding 20 ppb dioxin at
Times Beach.
. - Offsite thermal treatment of the contaminated soils and
debris from the MjSjRC site, at a location other than Times
Beach.
- Potential offsite thermal treatment of the contaminated soil
and debris from the other sites listed in Table 1, at
a site other than Times Beach.
- Demolition and onsite disposal of the structures remaining at
Times Beach.
-. Placement of a one-foot soil cover over portions of Times
Beach with residual dioxin levels between 1 and 20 ppb
dioxin. .'
For the Times Beach soils, Alternative 1 includes installation of
a cap over contaminated soils exceeding 20 ppb, meeting
recommended RCRA design guidance for hazardous waste land
disposal facilities. The cap would be of multilayer design,
beginning at the base with a bedding layer of clean soil,
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followed by geotextile fabric, impermeable synthetic membrane,
geotextile fabric, drainage gravel, geotextile fabric, and
covered with a vegetated soil layer. In addition, a one-foot
vegetated soil layer would be placed over all areas with surface
dioxin levels greater than 1 ppb, but less than 20 ppb.
The contaminated soils from M/S/RC would be taken to a
thermal treatment unit to be built at a site other than Times
- Beach. A site for the thermal treatment unit has not been
identified, but for cost estimation purposes, it is assumed to be
within 50 miles of M/S/RC. This alternative assumes, as do
Alternatives 2 and 3, that the contaminated soil from the other
potential sites would also be taken to this thermal treatment
unit. -
This alternative would also include, as do all of the other
alternatives, demolition and onsite disposal of the structures
which remain at Times Beach. The disposal-would be in accordance
with RCRA subtitle D and the Missouri Solid Waste Management Law
and regulations. The non-hazardous solid waste from the
demolition of the buildings may be baled or incinerated (for
volume reduction purposes) prior to disposal in compliance with
state requirements.
Alternative ~
- An imperme~ble (non-RCRA) cap over the contaminated areas
exceeding 20 ppb at Times Beach.
- Offsite thermal treatment of the contaminated soils and
debris from the M/S/RC site, at a location other than Times
Beach.
- Potential offsite thermal treatment of the contaminated soil
and debris from the other sites listed in Table 1 at a site
other than Times Beach.
- Demolition and onsite disposal of the structures remaining at
Times Beach.
- Placement of a one-foot soil cover over portions of Times
Beach with residual dioxin levels between 1 and 20 ppb.
Alternative 2 was developed at the request of citizens
attending the Times Beach public meeting February 12, 1987. It
is identical to Alternative 1, except in the details of the cap
that would be placed over the contaminated soils at Times Beach.
The cap would consist of just two layers. . contaminated areas
within Times Beach would be covered with an impermeable membrane,
which would then be covered with a 12-inch layer of clean soil
and revegetated. .
Alternative 1
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- Onsite land disposal of the contaminated soils exceeding 20
ppb at Times Beach.
- Offsite thermal treatment'of the contaminated soils and
debris from the M/S/RC site, at a location other than Times
Beach.
- Potential.offsite thermal treatment of the contaminated soil
and debris from other sites listed in Table 1 at a site
other than Times Beach.
Demolition and onsite disposal of the structures remaining at
Times Beach.
- Placement of a one-foot soil cover over portions of Times
Beach with residual dioxin levels between 1 and 20 ppb.
Alternative 3 would be identical to Alternatives 1 and 2,
except in the final remedy for the contaminated soils at Times
Beach. With Alternative 3, contaminated soils at Times Beach
would be excavated and placed in an above-ground concrete
hazardous waste disposal facility. It is assumed that the
hazardous waste land disposal facility would be located in the
northwest section of Times Beach.
Alternative ~
- Onsite thermal treatment of the contaminated soils exceeding
20 ppb at Times Beach.
- Offsite thermal treatment at Times Beach of the contaminated
soils and debris from the M/S/RC site at Times Beach.
- Potential offsite thermal treatment at Times Beach of the
contaminated soil and debris from other sites listed in
Table 1.
- Demolition and onsite disposal of the structures remaining at
Times Beach.
- Placement of a one-foot soil cover over portions of Times
Beach with residual dioxin levels between .1 and 20 ppb.
Alternative 4 is different from all of the other alternatives,
except in the demolition and disposal of the structures remaining
at Times Beach and placement of a 1-foot layer of clean soil over
areas between 1 and 20 ppb. With Alternative 4, the soils
contaminated with dioxin levels above 20 ppb would be excavated
from Times Beach and treated in a temporary onsite thermal
treatment facility. Unlike Alternatives 1 through 3, this
alternative would involve thermal treatment of the soils from
M/S/RC and the other identified sites at Times Beach. Ash from
the incineration process would be delisted and land disposed
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onsite (at Times Beach) as a solid waste in a new unit designed
in accordance RCRA subtitle D and the Missouri Solid Waste
Management Law and regulations.
Following completion of thermal treatment of the contaminated
soils, the temporary thermal treatment facility would be
dismantled and removed from Times Beach. Excavated areas within
Times Beach would be backfilled to original grade with clean soil.
Grading would be performed as necessary to re-establish site
drainage.' .
As with all of the other alternatives, all areas at Times
Beach with surface dioxin levels exceeding 1 ppb but less than 20
ppb would be covered with a 12-inch vegetated layer of clean
soil.
Alternative 2
- Onsite land disposal of the contaminated soils exceeding 20
ppb at Times Beach.
- Offsite land disposal at Times Beach of the contaminated
soils and debris from the M/S/RC site.
- Potential offsite land disposal at Times Beach of the
contaminated soil and debris from other sites listed in
Table 1. .
Demolition and onsite disposal of the structures remaining at
Times Beach.
Placement of a one-foot soil cover over portions of Times
Beach with residual dioxin levels between 1 and 20 ppb.
Alternative 5 would involve land disposal of all the dioxin
contaminated soils. All of the contaminated soils from the
eastern Missouri dioxin sites would potentially be brought to
Times Beach and disposed of with the Times Beach soil in an
above-grade hazardous waste disposal facility. The facility
would be designed to meet the RCRA requirements for a hazardous
waste land disposal facility and would be flood-protected.
IX.
SOKMARY OF THB COMPARATIVE ANALYSIS OF ALTERNATIVES
The five .alternatives were evaluated using. evaluation
criteria presented in EPA Directive 9355.3-02, "Draft Guidance on
Preparing Superfund Decision Documents: The Proposed Plan and
Record of Decision." . These criteria relate directly to factors
mandated by CERCLA in Section 121 and considerations which measure
the overall feasibility and acceptability of the remedy. These
evaluations are summarized below.
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Protection of Human Health and the Environment
Protection of human health and the environment is the
cen~ral mandate of CERCLA, as amended by SARA. Protection is
achieved by reducing risks to acceptable levels and taking action
to ensure that there will be no future unacceptable risks to
human health and the environment through any exposure pathway.
Different remedial alternatives will have varying long-term and
short-term impacts on the protection of human health and the
environment.
All alternatives evaluated in this document provide some
degree of protection of public health and the environment. The
degree of protection and the permanence of the protectiveness
vary between the alternatives. Alternatives involving excavation
of contaminated soils from the uncontrolled situation at Times
Beach would provide a higher long-term degree of protection for
human health and would minimize the need for ongoing operation
and maintenance (O&M) activities and land use restrictions.
Alternatives involving long-term management of the soil in-place
or in a disposal unit would require more extensive monitoring and
maintenance and reliance upon land us~ and access restrictions to
adequately protect human health and to assure the continued
effectiveness of the remedy.
Dioxin levels remaining following removal of soils exceeding
health-based levels for designated non-residential land usages
represents a greatly reduced risk to human health and the
environment relative to levels currently present at Times Beach.
The one-foot vegetated soil cover which is proposed for areas
exceeding 1 ppb dioxin would further'reduce risk by providing
both a barrier against potential exposure and dilution of .
subsurface soils in the event of soil disturbance.
Both treatment and disposal were considered for final
management of contaminated soils. Land disposal results in some
risk of future release from the disposal facility as long as the
dioxin remains in the environment. Thermal treatment of
contaminated soil destroys dioxin to undetectable levels,
permanently removing the contamination from the environment and
eliminating the need for continuing maintenance or monitoring of
the treated material.
Protection of the Bnvironment: The primary environmental concern
at Times Beach is the potential migration of. dioxin into the
Meramec River. contaminated sediment has been detected in
roadside drainageways, but there is no indication that a
significant amount of this material is reaching the Meramec River
yet. Sediment and fish samples collected to date do not indicate
that Times Beach is contributing a significant amount of dioxin
into the Meramec. Romaine Creek is believed to be a primary
contributor of dioxin into the Meramec due to the presence of
several confirmed dioxin sites in the Romaine Creek watershed.
Biota samples collected upstream and downstream of Times Beach in
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1984 do not display a significant difference in dioxin levels.
The data from this study indicate that dioxin levels in Meramec
River biota are primarily due to sources downstream of Times
Beach.
A limited potential exists for Times Beach to contribute
dioxin into the Meramec River during flood events, because flow
occurs over the Times Beach river banks.. This potential will be
sUbstantially reduced by all of the alternatives being considered
for the contaminated soils at Times Beach because of the
reduction of surface dioxin concentrations. In addition, the
Times Beach Spur Levee Project is nearing completion, which will
result in permanent measures to control erosion potential at
Times Beach. in the event of flooding.
The placement of a one-foot cover over areas above 1 ppb in
addition to removal of soils above 20 ppb would reduce or
eliminate the existing potential for environmental impairment.
The continued integrity of the soil cover would riot be critical
for maintaining the effectiveness of the remedy if all soils
exceeding 20 ppb were first removed, because this reduction in
surface concentration alone would substantially reduce any
potential for environmental impact from Times Beach soils.
Isolated breaches of the soil cover would not be of concern due
to the negligible impact on overall average surface
concentrations. Future contaminant degradation and mixing of
soils through natural processes is expected to further reduce
residual dioxin concentra~ions and the potential for
environmental impairment.
Protection of Human Health: In this document, EPA establishes a
cleanup level for dioxin-contaminated soils at Times Beach.
Cleanup levels have previously been established for all portions
of M/S/RC.
A cleanup level of 20 ppb has been recommended by Federal
and State health agencies for the protection of public health at
Times Beach, based upon non-residential land usage. The Agency
believes that the continued non-residential usage of Times Beach
is assured through a combination of existing contractual and
statutory controls and practical considerations.
The Federal Emergency Management Agency, the State of
Missouri, st. Louis County, and the Trustee for the city of Times
Beach entered into a four-party contract in ~983 for the
permanent relocation of residents and businesses. This four-
party contract requires that future land use at Times Beach be
limited to only that usage which the Missouri Department of
Health and the Centers for Disease Control deem safe. In
addition, no portion of the site can be conveyed by the State
unless approved by state and federal health agencies, after
consultation with EPA.
Times Beach is listed on the State of Missouri's Registry of
Abandoned or Uncontrolled Hazardous Waste Disposal Sites.
/1
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Missouri law requires that the state must concur with any request
to change the land usage of a site on this registry. By this
mechanism, the state of Missouri has an additional measure of
control over future land use at Times Beach.
In addition to these contractual and statutory controls,
practical considerations exist that preclude future residential
usage of Times Beach. The previous development of Times Beach
from a recreational area to a year-round residential area
primarily occurred in the absence'of major flooding. In fact, no
major floods occurred at Times Beach during the period between
1919 and 1942. The frequency of major flooding of Times Beach
has increased in later years. The continued development of the
Meramec River watershed contributes to this increased frequency.
A substantial portion of Times Beach is currently located in the
five-year floodplain of the Meramec River, and all of Times Beach
is located in the 25-year floodplain. Future residential
development is not practical in an area which is subject to such
frequent flooding.
Restoration of Times Beach to residential usage would also
not be cost-effective. The cost to protect the contaminated
portion of Times Beach from the 100-year flood was estimated at
$31 million in the 1984 Times Beach Flood Control study prepared
by the U.s. Army Corps of Engineers. Protection of the site from
the Standard Project Flood was estimated at $63 million. This
cost is in addition to measures taken to remediate the dioxin
contamination to levels acceptable for residential usage. The
increase in value of the land at Times Beach 'with reside~tial
usage is not co~ensurate with the additional cost of restoring
Times Beach to allow residential usage. There does not exist a
financial incentive to restore Times Beach to allow future
residential development. .
In-place containment oj the Times Beach soils (Alternatives
1 and 2) would attain the objective of reducing surface
concentrations of dioxin to an acceptable level. Monitoring and
maintenance requirements would be more extensive than for
alternatives involving the removal of contaminated soils.
Eventual replacement of the cover or cap may become necessary.
Land use restrictions would also be necessary to protect the soil
cover and prevent possible human exposure in the event of cover
failure. In the event of cap failure, there would be potential
for offsite migration and human exposure.
Land disposal of the contaminated soils' in a permanent
facility meeting RCRA design criteria (Alternative 3) would
provide a higher degree of protection to public health and the
environment than in-place containment alternatives. There would
be some risk of release due to failure of the disposal facility.
This risk should be minimal if the disposal facility is properly
designed, constructed, and maintained. Regular monitoring and
maintenance would be required to assure the continued integrity
of the land disposal facility. Access restrictions would also be
required to protect the disposal facility and prevent possible
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human exposure in the event of a facility failure. Facility
failure could potentially release a substantial volume of
contaminated soil into the environment during flood events
because all contaminated soils would be consolidated in one
location.
An increased short-term risk associated with soil-disturbing
activities is associated with all of the alternatives involving
. excavation and handling of dioxin-contaminated soil. This short-
term risk is due to potentially contaminated dust which could be
created during excavation activities. Mitigative measures, such as
dust suppression, are available to control this potential risk.
Thermal treatment alternatives represent technologies which
have achieved destruction of dioxin in soils to undetectable
levels. These alternatives provide the greatest level of long-
term protection of human health and the environment of the
alternatives evaluated in the feasibility study because the
toxicity, mobility, and volume of contaminated materials would be
sUbstantially reduced in comparison to the containment
alternatives.
During thermal treatment, there would be a short-term
potential for dust and particulate generation during materials
handling and preparation activities. The potential for air
releases of products of incomplete combustion also exists.
Measures would be taken to ensure that all these potential
hazards are controlled prior to full-scale operation. Workers
would be protected through measures outlined in project-specific
health and safety plans and through contractor adherence to
Occupational ~afety and Health Act (OSHA) regulations.
Ongoing monitoring and maintenance requirements are less for
alternatives involving removal of contaminated soils than for in-
place containment alternatives. The Centers for Disease Control'
(Agency for Toxic Substances and Disease Registry) has
recommended that removal of soils exceeding 20 ppb at Times Beach
is protective of human health for designated non-residential land
usages. Since soils exceeding health-based levels are removed,
the continued integrity of any subsequent cap or soil cover is
not essential to maintain the effectiveness of the remedy. In-
place containment alternatives do not remove soils which exceed a
level of concern for protection of human health for the
designated non-residential land usage. The continued integrity
of the cap or cover is therefore critical in maintaining the
effectiveness of in-place containment remedies.
Specific ongoing operation and maintenance requirements for
alternatives involving the removal of soils exceeding 20 ppb
would be limited to annual or semi-annual inspections to verify
that land use remains consistent with the level of cleanup and
that widespread disturbance of surface soils does not occur.
Small isolated disturbances of the soil cover would not be of
concern due to the negligible impact on overall average surface
concentrations. In the event that surveillance identifies areas
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where widespread soil disturbance has occurred, an evaluation
would be required, in consultation with appropriate health
agencies, to determine if corrective measures are necessary.
All alternatives involving transportation of dioxin-
contaminated soils to an offsite location for treatment or
disposal would require special considerations to assure the
short-term protection of human health and the environment during
transport. These considerations include the method of
containment and transport of contaminated soil, transportation
routes and scheduling of hauls.
A detailed transportation plan would be developed in
coordination with the local community prior to final design.
Potential transportation routes to Times Beach would be evaluated
in consideration of the locations of schools, hospitals, and
other public facilities. The transportation plan would also
address transportation schedules and evaluate opportunities to
reduce the risk of traffic accidents. Local officials would be
given an opportunity to participate in the development of this
plan in order to address the comments and concerns of the local
community.
Compliance with Applicable Q£ Relevant and Appropriate
Reauirements
section 121(d) of CERCLA, as. amended by SARA, requires that
remedial actions comply with applicable or relevant and
appropriate requirements or standards (ARARs) under Federal and
. State environmental laws. Such a standard or requirement must be
attained if it is determined to be either directly applicable or
both relevant and appropriate. Some of the requirements
discussed in this section are directly applicable to a particular
aspect of a remedial alternative. Other requirements are
identified as being both relevant and appropriate to a remedial
alternative. Both of these categories of requirements constitute
ARARs and must be attained by the remedial alternative. In some
cases, requirements are identified that are relevant to a
particular. alternative but not appropriate under the
circumstances. These latter requirements do not constitute
ARARs, and their attainment is not required by the remedial
alternative.
The following potential ARARs have been .identified and
evaluated for remedial alternatives in this Record of Decision:
o Resource Conservation and Recovery Act
o Missouri Hazardous Waste Management Law
o Federal and State Clean Water Acts
0 Federal and State Transportation Laws and Regulations
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o
state Solid Waste Management Laws
o
Clean Air Act, Missouri Air Conservation Law
These ARARs, which havp- the most impact on the remedy selectioTlI
are discussed below. More complete discussions of the potential
ARARs are presented in the feasibility studies for Times Beach
and M/S/RC.
Onsite actions, such as the disposal of structures and
debris, are exempt from the need to actually obtain a State
permit which is considered an administrative requirement.
Nevertheless, such onsite actions are required to meet all
substantive requirements of ARARs.
Remedial actions conducted pursuant to CERCLA must achieve
the substantive requirements of all ARARs. CERCLA section 121(d)
requires that remedial actions shall require a level or standard
of control for haz~rdous substances, pollutants, or contaminants
that attains ARARs. Levels or standards of control are basic
performance objectives for the remedial action. These basic
performance objectives are defined by so-called substantive
ARARs.
Superfund actions conducted onsite are exempt from
administrative requirements of ARARs. Requirements which do not
in and of themselves define a level or s~andard of control are
considered administrative. Administrative requirements include
the approval of, or consultation with, administrative bodies,
issuance of permits, documentation, and, generally, reporting and
recordkeeping. The Superfund program imposes its own reporting
and recordkeeping requirements to ensure that substantive levels
or standards of control are being met.
Resource conservation and Recovery Act (RCRA)
RCRA, as amended by the Hazardous Solid Waste Amendments
(HSWA) in 1984,' regulates the generation, transportation,
treatment, storage, and disposal of hazardous wastes. As of July
15, 1986, certain dioxin-containing wastes are specifically
regulated under RCRA as hazardous wastes (the "dioxin rule," 50
FR January 14, 1985). The original source of the dioxin waste
that was spread at Times Beach is included in the sources of
dioxin wastes listed in the dioxin rule (RCRA waste F020).
However, the dioxin-contaminated soil left in place at Times
Beach is not regulated by RCRA because the soil was contaminated
prior to the effective ,date of the "dioxin rule."
For alternatives in which dioxin-contaminated soil is
excavated, some portions of RCRA are applicable to the removed
soil because the act of excavation constitutes generation of a RCRA
listed hazardous waste. Because it would involve land disposing
dioxin-contaminated soil from other sites at Times Beach,
Alternative 5 would require that the land disposal unit be
"1-'
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permitted under RCRA. Likewise, a thermal treatment unit
receiving contaminated soil from offsite would require a RCRA
permit.
RCRA is not directly applicable to dioxin-contaminated soils
remaining in place because the actual placement of the wastes
occurred prior to the effective date of the RCRA regulations for
dioxin wastes. However, some portions of RCRA are relevant to
some contaminated soils that remain in place. In order to
constitute an ARAR, a requirement must be both relevant and
appropriate. RCRA regulations would not be appropriate to
undisturbed soils remaining in place containing dioxin
concentrations below health-based levels, because protectiveness
is achieved by the removal of soils which represent a risk to
human health and the environment.
The RCRA program is delegated to the state of Missouri, with
the exception of certain regulations promulgated since the
Hazardous and Solid Waste Amendments in 1984. The Missouri
Hazardous Waste Management Law is nearly identical to RCRA in the
regulation of dioxin wastes. Significant exceptions are Missouri
hazardous waste landfill siting requirements for new facilities
which require a minimum of 30 feet of underlying clay (with
hydraulic conductivity less than 10-7 cm/sec) and a prohibition
on siting hazardous waste land disposal facilities in the 100-
year floodplain.
Because RCRA is comprehensive in its regulation of all
aspects of hazardous waste management, it represents the
dominant regulatory scheme affecting the implementation of
remedial action alternatives for dioxin-contaminated soil.
most important of the RCRA issues are summarized below.
Landfill Closure and Post-Closure Requirements: Under RCRA,
closure of a RCRA-regulated land disposal facility must be
accomplished either by (1) removing or decontaminating all waste
residues, contaminated subsoils, structures and equipment
contaminated with waste, or (2) stabilizing and capping the
wastes, and complying with post-closure requirements, including
~aintaining a ground water monitoring system. In order to comply
with RCRA, a cap would have to be sloped to promote drainage, be
designed to require minimum maintenance, be protected against
stormwater run-on and runoff, and be less permeable than the
underlying soils.
The
Landfill closure requirements would constitute ARARs for the
in-place containment alternatives where contaminants remain above
health-based levels. In that case, the landfill closure
requirements would be both relevant and appropriate, because
health-based levels would be exceeded.
For alternatives involving the removal of soils, landfill
closure requirements would not constitute ARARs for the soil
remaining in place containing residual dioxin concentrations
below health-based levels. In this case, it would not be
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appropriate to apply these requirements to alternatives which
achieve protectiveness by removal of contaminated soils.
Delistinq: RCRA allows for the "delisting" of a hazardous waste
if it can be demonstrated that the waste no longer meets the
criteria for which it was originally listed as a hazardous waste.
Residues from the incineration of dioxin wastes are specifically
listed as "toxic" hazardous waste F028, until delisted.
Decontamination wastewaters, landfill leachate, and thermal
treatment residues (ash, flyash, and scrubber blowdown) must be
delisted if they are to be disposed in a non-hazardous waste
facility.
Dioxin-contaminated soil excavated from Times Beach and the
offsite locations would be listed hazardous wastes under RCRA,
due to the original source of the dioxin wastes. A formal
delisting petition would be required for residues generated from
the thermal treatment of offsite dioxin-contaminated soils
(i.e., ash) if the residues are to be subsequently
managed as a solid waste.
The Land Disposal Ban: Regulations have been promulgated by EPA
that will ban, except under specified conditions, land disposal
of certain dioxin-containing wastes. The soils at the
Minker/Stout/Romaine Creek and Times Beach sites represent
dioxin-containing wastes potentially regulated by this land
disposal ban. After these regulations become effective, a
dioxin-containing waste can be land disposed only if it passes a
certain leaching test (Toxicity Characteristic Leaching
Procedure). Samples of dioxin-containing wastes from th~
Missouri dioxin sites have previously been subjected to a similar
test (Extraction Procedure Toxicity Test), and no dioxin was
detected in the leachate. It is expected that the soils' from the
Minker/Stout/Romaine Creek and Times Beach Sites would pass the
test, and that the land disposal ban would not preclude the land
disposal alternatives evaluated in the Proposed Plan and this
Record of Decision.
Thermal Treatment Standards: The dioxin-listing rule
establishes standards for incineration and certain types of
thermal treatment. It states that. incinerators treating the
listed dioxin wastes must achieve a destruction and removal
efficiency (DRE) of 99.9999 percent (six-nines), in addition to
the other standards contained in 40 CFR 264.343 and 265.352.
Residues resulting from the incineration or thermal treatment of
dioxin-contaminated soils, like other dioxin~containing wastes,
must be tested to determine whether detectable levels of specific
categories of dioxins, chlorinated dibenzo-furans, and certain
chlorophenols are present in the extracts from the waste or
treatment residuals. .
It is anticipated that the thermal treatment options
evaluated will attain all identified applicable or relevant and
appropriate thermal treatment requirements. The thermal
destruction process would comply with all the applicable
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requirements of Part 264 subpart 0 of RCRA (Subpart 0 specifies
design requirements for operation of hazardous waste
incinerators). These include a demonstrated destruction and
removal efficiency (DRE) of six-nines in the exhaust gas relative
to the initial dioxin concentration in the soil. Any thermal
treatment unit used to treat material from offsite would require
a RCRA Part B permit.
Operation of a thermal destruction unit would require that
the transportable unit undergo waste-specific trial burns to
demonstrate satisfactory destruction of the toxic components of
the waste in accordance with RCRA Part B permit requirements.
Data obtained during the trial burn would also be used to support
the delisting petition for the ash and wastewater generated from
the thermal treatm~nt process.
Missouri Hazardous Waste Manaqeaent Law Sitinq Requirements
The Missouri Hazardous Waste Management Law (HWML) siting
regulations would be considered relevant and appropriate for
containment alternatives (Alternatives 1, 2, and 3). Conditions
do not exist at Times Beach which would allow the requirement for
30 feet of underlying clay to be met. This state requirement is
intended to provide a secondary barrier of in-situ natural
materials in the event of failure of the synthetic liner or other
primary containment system. The intent of this state requirement
is to avoid absolute reliance upon engineered containment.
systems, which generally have a designated design life, to
provide adequate long-term control against release of
contaminants into the environment. .
Section 121 of SARA contains a waiver provision from an
otherwise applicable or relevant and appropriate"requirement if
it can be demonstrated that the proposed remedy will attain an
equivalent level of control. Due to the intent of the state
requirement, this waiver provision could not be applied to allow
substitution of the clay barrier with a synthetic liner system.
However, under certain circumstances the Missouri Hazardous Waste
Management Law does allow for a waiver of the requirement for a
clay barrier for non-commercial facilities. It is possible that
the state could apply this .waiver to the requirements for
construction of a hazardous waste disposal facility at Times
Beach. However, construction of a hazardous waste disposal.
facility at Times Beach is precluded by additional state siting
requirements. . .
The Missouri HWML regulations prohibit siting a hazardous
waste land disposal facility in a lOa-year floodplain. Since all
of Times Beach is located within the lOa-year floodplain of the
Meramec River, a land disposal facility for dioxin-contaminated
soils at Times Beach is not allowed by state regulations without
measures to remove the facility from the floodplain. Under state
requirements, flood-protection of the facility with levees or
other structures does not remove the facility from the
floodplain. It would be necessary to fill contaminated
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portions of Times Beach to an elevation above the 100-year flood
height to comply with state siting requirements. The cost of
this measure would greatly exceed the cost of other remedial
alternatives affording a higher degree of protection of human
health and the environment. A potential waiver under Section 121
from this siting requirement has not been identified.
Clean Water Act
Dredge and fill permit requirements under Section 404 of the
Clean Water Act apply to any filling operation in the waters of
the United states, including wetlands. A floodplain, including
the floodway, is not necessarily considered to be "waters of the
United states." The Army Corps of Engineers, in conjunction with
the Times Beach Spur Levee project, has determined that there are
no wetlands within the Times Beach site.and none of the
alternatives would involve any filling activities below the
ordinary high-water mark of the Meramec River. Therefore, a
section 404 permit will be not be required for implementation of
any of the alternatives evaluated.
Missouri Water Quality criteria
The State of Missouri has adopted regulatory standards for
dioxin for protection of aquatiq life (0.000014 ng/l) and
drinking water (0.00013 ng/l). These standards are below
analytical detection levels. If dioxin can be detected in a
point-source discharge, these criteria are compared to the
concentration of dioxin in the discharge diluted by the relative
flowrate of the receiving water. None of the alternatives
evaluated include discharge into the Meramec River, therefore
Missouri Water Quality Criteria do not constitute ARARs.
The Missouri Department of Natural ~esources (MDNR) has
recommended land application of wastewater as an alternative to
surface water discharge. During the thermal treatment process,
wastewaters consisting of cooling and decontamination water will
be generated. This wastewater will be land applied following
testing to verify the absence of contamination. Land application
of wastewater will be performed at or below consumptive rates,
which requires approval from the state under Missouri
regulations. Such approval will be obtained from the State of
Missouri prior to disposing of wastewater. All substantive
provisions of the Missouri regulations governing land application
of wastewater will be complied with.
Clean Air Act, Missouri Air Conservation Law
The Clean Air Act and the Missouri Air Conservation Law
contain permitting requirements for sources of certain types and
quantities of air pollutants. During the pre-construction design
of the thermal treatment facility, an assessment will be made of
the type and the quantity of potential emissions. If this
assessment indicates that a permit is required, a permit will be
obtained. Although the RCRA thermal treatment performance
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standards are more stringent than Clean Air Act requirements, in
most respects, emissions of some of the more conventional
pollutants are not addressed by the RCRA standards. The Federal
Clean Air Act program is administered by the MDNR and st. Louis
County. The st. Louis County Air Pollution Control section and
Missouri Air Pollution Control Program have a "joint concurrence"
agreement for regulating major sources.
Solid Waste Disposal RegulatioDs
Missouri solid waste management regulations require that
solid waste, in general, be disposed of in a landfill meeting
design and operating requirements of a demolition or sanitary
landfill. Missouri solid waste management regulations also
require that any landfill located in a floodplain must be
designed to prevent floodwater from contacting the solid waste.
An additional waste category, "special waste," has been created
for those solid wastes requiring handling other than normal
municipal wastes. Special wastes are subject to waste-specific
disposal requirements established on a case-by-case basis.
Incinerator ash is generally considered a special waste. These
special waste requirements may apply to the disposal of delisted
incinerator ash generated from the treatment of dioxin-
contaminated soil.. The State of Missouri maintains that. a state
non-hazardous solid waste permit is required for the land
disposal of the delisted ash at the Times Beach site.
Approval will be obtained from the. state.prior to onsite
land disposal at" residue (ash) from the thermal treatment
process. This approval will serve to assure the State and local
community that all provisions for the safe disposal of the
delisted ash have been achieved. Prior to design, approval will
be obtained from the state for the type of solid waste disposal
. facility to be constructed. The state will also designate
specific solid waste disposal requirements for the incinerator
ash. County solid waste disposal requirements will be considered
in the design of the disposal unit for the incinerator ash.
The delisted ash resulting from thermal treatment may be
considered for use as backfill material at Times Beach in
combination with sufficient clean soil to maintain vegetation.
Such use of the ash would constitute beneficial use of the solid
waste, and would not be subject to permitting requirements which
apply to traditional solid waste disposal un~ts. state
regulations require that beneficial use of a solid waste can only
be conducted with approval from the state. Such approval from
the state would be obtained prior to use of the ash as a
component of the backfill material.
Disposal of structures and debris at Times Beach constitutes
an onsite action performed pursuant to CERCLA authority, and is
therefore exempt from administrative permitting requirements,
although substantive requirements must be met. All substantive
provisions of the state solid waste management requirements will
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be met for onsite disposal of structures and debris at Times
Beach. These requirements include identification of the type of
solid waste disposal facility required and specific solid waste
management requirements for disposal of structures and debris at
Times Beach. county solid waste disposal requirements will be
considered in the design of the solid waste disposal unit for the
Times Beach structures and debris.
Wetlands and Floodplains Regulation
Bxecutive Order 11988: This executive order requires that any
Federal agency undertaking a project in a floodplain determine
whether or not practicable alternatives exist that would allow
the project to be moved out of the floodplain. An eight-step
process has been established to ensure that impacts on the
floodplain are identified and mitigated and to ensure adequate
public participation in the decision.
EPA has prepared a floodplain assessment for Times Beach.
This and other components of the CERCLA remedy selection process
assure compliance with the Executive Order.
The remedy selection process under CERCLA involves
identifying and evaluating alternatives for site remediation. As
a result of this remedy selection process, it has been determined
that no practicable alternatives exist to implementation of the
project in the floodplain of the Meramec River. Offsite capacity
for management of dioxin contaminated materials at Times Beach
and M/S/RC has not been iaentified. It is not feasible to .
implement the preferred alternative at the M/S/RC site due to
the absence of sufficient area to implement the project.
Establishment of a new offsite facility for implementation of the
preferred alternative would involve considerable delays during
siting, development, and permitting activities. An unacceptable
level of exposure would continue to occur during this delay. In.
addition, it has been determined that it is cost-effective to
implement the preferred remedy at Times Beach, since the land is
being acquired as a result of the permanent relocation, and no
additional land will have to be purchased, leased, or otherwise
acquired to implement the project.
Bxecutive order 11990: This order relates to activities
that impact or modify wetlands. As noted above, the Army Corps
of Engineers has determined that no wetlands exist at the Times
Beach site~
Reduction Q1 Toxicitv. Mobilitv. or Volume
This evaluation criterion relates to the performance of a
technology or remedial alternative in terms of eliminating or
controlling risks posed by the toxicity, mobility, or volume of
hazardous substances.
The inplace containment alternatives (Alternatives 1 and 2)
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would reduce the mobility of 'the contaminated soils. However,
the toxicity and volume of the contaminants would remain at
current levels. If in the future it is determined that removal
of contaminated soil is required, removal of the uncontaminated
cap would also be necessary. It would be difficult to completely
segregate the cover material from the underlying contaminated
soil during removal. Thus, the volume of material possibly
requiring future management would be increased by the additional
volume of the cover or cap.
Land disposal of contaminated soil (Alternatives 3 and 5)
would provide greater assurance against .contaminant migration
than in-place containment. However, the toxicity and volume of
the wastes would remain at current levels.
Thermal treatment (Alternative 4) is capable of reducing
dioxin levels in soil to undetectable levels. Thermal treatment
permanently removes the contaminants in the treated soils from
the environment, thereby eliminating mobility and toxicity.
Placement of a soil cover over areas exceeding 1 ppb dioxin
following removal of soils exceeding health-based levels for the
designated non-residential land usage would further reduce the
potential for mobility of contamination. Following delisting,
the volume of the wastes, while reduced to some extent in the
incineration process, would no longer be relevant since the
wastes would no longer be hazardous.
Short-Term Effectiveness
Short-term effectiveness measures how well an alternative.
is expected to perform, the time to achieve performance, and the
potential adverse .impacts of its implementation.
Of the alternatives evaluated, in-place containment of
contaminated soils would provide the highest level of short-term
protection. Short-term protection is high because implementation
of in-place containment does not involve excavation or other
soil-disturbin9 activities which could potentially impact site
workers or the surrounding community.
Alternatives involving the excavation and subsequent
management of contaminated soils provide increased opportunity
for exposure to contaminants by site workers due to soil-
disturbing activities. Thermal treatment an~ land disposal
alternatives would require additional soil handling operations to
render the soil suitable for treatment or disposal. Measures
could be implemented which would contre: the potential for worker
exposure during soil-disturbing and han~ling activities. These
measures include use of protective clothing and effective dust
control. These same measures would also assure the short-term
protection of the surrounding community during periods of
excavation and soil handling.
A limited potential exists for contaminants to be emitted
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into the air during operation of the thermal treatment unit. The
thermal treatment unit would be equipped with redundant safety
features and operated under strict conditions which would control
the potential for any hazardous emissions from the thermal
treatment unit to occur.
The time to achieve protectiveness varies widely among the
alternatives evaluated. Implementation of in-place containment
alternatives for the Times Beach soils could be completed within
15 to 19 months after completion of design, depending upon the
complexity of installation and cap design. Onsite land disposal
of contaminated soils from Times Beach could be implemented
within 19 months of completion of design. Land disposal at Times
Beach of the contaminated soil from the Minker/Stout/Romaine
Creek site could be implemented in approximately 14 months,
depending. on excavation schedules, soil volume and permitting
delays.
The time required to thermally treat contaminated soils is
dependent upon a number of factors, including the capacity of the
thermal treatment unit and the amount of time that the unit is
down for maintenance or repairs. Treatment times were estimated
by assuming a treatment capacity of 4.25 cubic yards per hour and
70% on-line efficiency (approximately 100 tons per day). These
estimates do not include allowances for site preparation,
mobilization and demobilization, which will increase the total
implementation time by approximately two years. The net
treatment time for contaminated soils from Times Beach and the
Minker/stoutjRomaine Creek site is estimated. at twelve months.
Thermal treatment of 66,600 cubic yards of soil from the other
designated eastern Missouri dioxin sites could be completed
within approximately 31 additional months. This results in a
total potential project duration of approximately six years.
Lonq-Term Effectiveness and Permanence
Long-term effectiveness and permanence addresses the long-
term protection and reliability an alternative affords.
In-place containment alternatives provide the lowest degree
of long-term effectiveness and reliability of the alternatives
evaluated. Frequent inspection and maintenance of the cap or
cover would be required, including mowing, fertilizing, and
repair. In addition, access restrictions would be required in
order to prevent possible disturbance of the cap or cover.
Ground water monitoring may be required to verify .that dioxin .is
not contaminating ground water.
. Land disposal offers considerable long-term effectiveness
and reliability. Siting a permanent disposal facility in a
floodplain would increase the potential for eventual failure.
Continued management of the facility would be required to
maintain the effectiveness of the remedy. .
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Thermal treatment alternatives provide the highest degree
of long-term protection and reliability of the alternatives
evaluated. As noted above, thermal treatment results in the
destruction of dioxin in the treated soils and eliminates the
potential for future exposure to this contaminated material.
Ongoing maintenance requirements are greatly reduced relative to
the other alternatives considered involving in-place containment
or land disposal. Since the contamination exceeding health-based
levels for the designated non-residential land usage is
destroyed, future monitoring involving soil testing would be
required only upon the advice of health agencies in the event of
large-scale soil disturbance. Seasonal maintenance, including
mowing, fertilizing, and control of erosion would be adequate to
assure the continued protection of human health and the
environment.
ImDlementability
Implementability considerations address how easy or
difficult, feasible or unfeasible, it would be to carry out a
given alternative from design through construction, operation,
and maintenance.
The implementability of in-place containment alternatives
is limited by several technical problems. Establishing
vegetation would be difficult on a thin soil layer covering an .
impermeable membrane. The impermeable membrane would disrupt the
natural percolation and infiltration processes, impacting soil' .
moisture conditions. An impermeable. membrane placed "at a shallow
depth below the surface would also limit the depth of root
penetration and reduce drought tolerance. The membrane would
force lateral movement of water infiltrating from the surface
following rain events or flooding. This lateral movement could
potentially transport soil particles, resulting in gradual
depletion of the soil cover.
Installation of a cap meeting R~RA standards would also be
difficult to successfully implement. The RCRA design guidance
should be considered in the design of a cap or cover system.
This guidance specifies a vegetated top cover, a middle drainage
layer, and a low permeability bottom layer. This type of cap
over roadways in Times Beach may be aesthetically objectionable
and is not practical due to site drainage difficulties which
could cause unhealthy conditions to develop. The cap design
would require modification to achieve an equ~valent level of
control while minimizing cap thickness. For purposes of this
evaluation, the thickness of the low permeability bottom layer
was reduced to twelve inches, resulting in a total cap thickness
of four feet. Installation of a four-foot-thick cap over the
contaminated roadways in Times Beach would still result in
considerable drainage problems. Allowances for effective
drainage of uncontaminated areas would have to be provided in the
design.
Implementation of onsite disposal would be relatively
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straightforward. The disposal facility would have to be flood-
protected or designed to withstand regular flooding. An attempt
by EPA in 1984 to construct a land disposal facility at Times
Beach was unsuccessful due to State administrative and
legislative action which eliminated funding for the required
state cost share. The public was opposed to construction of a
disposal facility at Times Beach at that time, and have continued
to express opposition to any type of permanent hazardous waste
- management facility at the site.
If a disposal facility were designed to accept contaminated
soil from offsite, a RCRA Part B permit would be required.
Put~ic participation requirements would be followed during the
permitting process for the disposal unit.
Implementation of thermal treatment involves relatively
complex technologies. These measures have been successfully
implemented during the cleanup of other Superfund sites. The
time required to complete thermal treatment varies depending upon
treatment capacity and volume of waste. Multiple thermal
treatment units could be used concurrently in order to decrease
the time required to complete the remedy.
Routine maintenance and monitoring of the thermal
4estruction unit would ensure reliability and minimize the .
potential for failure. If monitoring indicates the potential for
failure of the thermal destruction unit, the unit would be shut
down until corrective measures are taken. Operation of thermal
destruction units has shown that they are capable of successfully
destroying dioxin~contaminated materials and are able to meet
applicable or relevant and appropriate requirements. In
addition, operation of the EPA mobile incinerator system has
demonstrated that the residues from the treatment of dioxin-
contaminated materials can be successfully delisted. Sufficient
disposal capacity exists onsite for final- disposal of the
treatment residues.
Full-scale implementation of onsite thermal treatment
units at hazardous waste sites has been limited. Some such
units have experienced extended periods of downtime. It is
possible that operation of a unit at Times Beach would also
result in some extended downtime periods. The projected schedule
for the cleanup of Times Beach does allow for 30 percent
downtime. Downtime exceeding this allowance could delay the
completion of thermal destruction of contaminated soils.
Cost
CERCLA requires that EPA select the most cost-effective (not
merely the lowest cost) alternative that protects human health
and the environment and meets the other requirements of the law.
EPA is currently proposing remedial alternatives for only Times
Beach and Minker/Stout/Romaine Creek. The five alternatives
would involve costs ranging from $23.8 million to $48.8 million
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for these two sites. The degree of protection offered by the
alternatives also varies. Comparisons of these differing levels
of costs for differing levels of protectiveness constitute the
cost-effectiv~ness evaluation EPA ~akes as part of the analysis
in selecting an alternative.
In order to ensure that the most cost-effective alternative
is selected, a detailed cost estimate is required. EPA has
prepared cost estimates in the form of tables which are attached
to this Record of Decision. (Attachment 2)
As noted previously, EPA cannot evaluate just the current
costs for remediating these two sites in isolation. There are
other considerations which also impact cost-effectiveness and
must be evaluated. Specifically, EPA must consider the potential
need for response at the other eastern Missouri dioxin sites (see
Table 1), and determine how the current decision for Times Beach
and Minker/Stout/Romaine Creek may affect the overall costs for
the entire eastern Missouri dioxin problem.
Accordingly, the overall alternatives include response
actions which were assumed for the other sites and which
represent EPA's best judgment as to the most likely alternative
to be selected. This has been done so that total costs for
cleaning up all of the eastern Missouri sites can be estimated
and compared. Estimates of the costs for cleaning up all of the
eastern Missouri sites (including Times Beach and M/S/RC) range
from $57.1 million to $118.2 million. The impacts of the current
decision for Times Beach. and M/S/RC on these total costs must be
considered'in selecting a remedy for the two sites.
The amounts of money that would be required to implement the
alternatives for Times Beach and M/S/RC alone appear below.
These are the costs that will be associated with the decision
that EPA is currently preparing to make.
Alternative 1. $31.4 million
Alternative 2. $29.4 million
Alternative 3. $26.4 million
Alternative 4. $48.8 million
Alternative 5. $23.8 million
In order to determine the impact of the decision for Times
Beach and M/S/RC on the total costs EPA ahd the state will
potentially incur in remediating all of the eastern Missouri
dioxin sites, estimates have been prepared of the total costs of
the alternatives:
Alternative 1
$112.1 million
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- RCRA equivalent cap over the contaminated areas exceeding 20
ppb at Times Beach; vegetated soil cover over areas 1-20
ppb.
- Offsite thermal treatment of the contaminated soils and
debris at the M/S/RC site at a location other than Times
Beach.
- Offsite thermal treatment of 'the contaminated soil and
debris from the other sites listed in Table 1 at a location
other than Times Beach.
- Demolition and onsite disposal of the structures remaining
at Times Beach.
Alternative 2
$110.1 million
- An impermeable (non-RCRA) cap over the contaminated areas
exceeding 20 ppb at Times Beach; vegetated soil cover over
areas 1-20 ppb.
- Offsite thermal treatment of the contaminated soil and
debris at the M/S/RC site at a location other than Times
, Beach.
- Offsite thermal treatment of the contaminated soil and
debris from the other sites listed in Table 1 at a location
other than Times Beach.
- Demolition and onsite disposal of the structures remaining
at Times Beach.
Alternative 3
$107.1 million
- Onsite land disposal of the contaminated soils exceeding 20
ppb at Times Beach; vegetated soil cover over areas 1-20
ppb.
- Offsite thermal treatment of the contaminated soil and
debris at the M/S/RC site at a location other than Times
Beach.
- Offsite thermal treatment of the contaminated soil and
debris from the other sites listed in Table 1 at a location
other than Times Beach.
- Demolition and onsite disposal of the structures remaining
at Times Beach.
Alternative ..
$118.2 million
- Onsite thermal treatment of the contaminated soils exceeding
20 ppb at Times Beach; vegetated soil cover over areas 1-20
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ppb.
- Offsite thermal treatment of the contaminated soils and debris
from the M/S/RC site at Times Beach.
- Offsite thermal treatment at Times Beach of the
contaminated soil and debris from the other sites listed in
Table 1.
Demolition and onsite disposal of the structures remaining
at Times Beach.
Alternative 5
$57.1 million
- Onsite land disposal of the contaminated soils exceeding 20
ppb at Times Beach; vegetated soil cover over areas 1-20
ppb.
- Offsite land disposal of the contaminated soils and debris
from the M/S/RC site at Times Beach.
- Offsite land disposal at Times Beach of the contaminated
soil and debris from the other sites listed in Table 1.
- Demolition and onsite disposal of the structures remaining
at Times Beach.
Considering the increased protectiveness and long-term
reliability of incineration, and" the impacts on the costs of the
overall solution, the most cost-effective alternative is
Alternative 4. This alternative does not represent the lowest
cost alternative. The increased cost over other alternative~ is
justified by the benefits offered by Alternative 4, which none of
the other alternatives offer to the same extent. The cost-
effec~iveness.is especially .clear when the total costs of the
overall solution are. compared.
Communitv AcceDtance
This evaluation criterion addresses the degree to which
members of local communities support the remedial alternatives
being evaluated.
The local communities have demonstrated divided support for
the various alternatives evaluated due to short-term remedial
action impacts and aesthetic impacts. Many residents of the
neighboring community of Eureka perceive the implementation of
any onsite disposal or thermal treatment alternatives as a threat
to the economic development and stability of their community.
Some Eureka residents have proposed that a remedial action be
implemented consisting of installation of an impermeable membrane
covered with a vegetated soil layer. Other local residents have
indicated support of centralized thermal treatment of soils from
Times Beach and other eastern Missouri dioxin sites.
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Public support varies depending upon whether the remedy
to be implemented at Times Beach addresses onsite soils only, or
includes soils from other eastern Missouri sites. Concerns of
residents near Times Beach differ from the concerns of residents
impacted by the other sites. Residents near the M/S/RC site and
other eastern Missouri dioxin sites are supportive of
establishing management capacity for contaminated soils from
their respective sites. Residents near Times Beach desire to
minimize the magnitude of the remedy and. associated public
attention drawn to their community.
Residents near Times Beach have expressed as their primary
concern the establishment of a permanent hazardous waste
management facility at Times Beach. Nearby residents have
expressed possible support of centralized thermal treatment if
they can be assured that the material to be transported to Times
Beach for treatment will be limited to designated materials and
that Times Beach would not become a permanent treatment facility.
Concern has also been raised about the level of truck traffic
associated with operation of a central thermal treatment unit at
Times Beach, and possible airborne emissions. The detailed
transportation plan developed in coordination with the local
community prior to implementation will address many of these
concerns.
Nearby residents have expressed concern regarding possible
noise which may be generated during routine operation of an
onsite thermal treatment unit and/or associated air pollution
control equipment, materials handling equipment, and materials
pretreatment equipment. Any such noise should not be detectable
from the adjacent community. Any components of the thermal
treatment unit which generate an unacceptable level of noise can
be housed in insulated facilities or have other measures
implemented which will reduce noise to an acceptable level.
state Acceptance
state acceptance addresses the concern and degree of
support that the state government has expressed regarding the
remedial alternative being evaluated.
The state has supported thermal destruction of dioxin-
contaminated soils excavated from eastern Missouri dioxin sites
at a central location. Support of this concept was initially
advanced by former Missouri Governor Christopher Bond in a
December 8, 1982, correspondence to the EPA Assistant
Administrator for the Office of Solid Waste and Emergency
Response. In this correspondence, it was requested that
contaminated soils be excavated and that the possibility of
incineration should be explored. The Governor, at that time,
expressed willingness to provide the required ten percent state
cost share to assist in this effort.
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On February 14, 1983, Governor Bond, by executive order,
established a Governor's Task Force on Dioxin. The task force
submitted its final report to the Governor on October 31, 1983,
recommending that dioxin-cont~min~ted soil at sit~s in Missouri
be excavated and stored until a proven technology is av~ilable to
assure a comprehensive and permanent solution to dioxin
contamination with minimum risk to public health and the
environment. The EPA believes that thermal treatment represents
such a proven ~echnology.
The state of Missouri has operated a test facility at Times
Beach'since 1984, which allows independent researchers to
evaluate the effectiveness of dioxin destruction technologies in
the field. To date, only thermal treatment technologies have
demonstrated success at reducing contaminant levels in soils to
the extent required for delisting of the waste and protection of
human health.
In correspondence of May 7, 1986, the state requested that
EPA evaluate Times Beach for estabLishment of a centralized
thermal treatment facility to accept dioxin-contaminated soils
from eastern Missouri. This alternative was evaluated in the
feasibility study and proposed plan prepared for Times Beach.
In correspondence of March 18, 1988, the state commented on
the Times Beach Proposed Plan and provided conditions and
restrictions necessary for their support of the proposed remedy.
The conditions and restrictions requeste~ by the state have been
incorporated irito this Recora of Decision, and are discussed
individually in the Responsiveness Summary.
The State in its comment on the Proposed Plan asked EPA to
strongly consider cleaning up all areas exceeding 10 ppb. The
EPA understands this request to represent the state's desire for
additional soils containing dioxin levels between .10 and 20 ppb
to be excavated, thereby reducing or eliminating future operation
and maintenance costs. The EPA has determined that removal of
soils containing dioxin levels less than 20 ppb is not required
to achieve protection of human health or the environment.
x.
THB SBLECTED REMEDY
Based on the information available to evaluate the remedial
options against these nine remedy selection criteria, EPA has
concluded that Alternative 4 provides the most acceptable balance
of factors in comparison to the other alternatives evaluated.
This alternative is protective of human health and the
environment, cost~effective, attains ARARs, and utilizes
permanent solutions and resource recovery technologies to the
maximum extent practicable. Additionally, because this
alternative employs thermal destruction to eliminate the
principal threat at the site, this option also satisfies SARA's
preference for remedies which utilize treatment as their
principal element to reduce toxicity, mobility, and volume.
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The selected remedy is consistent with the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980
(CERCLA), the Superfund Amendments and Reauthorization Act of
1986 (SARA), and the National Contingency Plan (NCP)i 40 CFR Part
300 et seq.
Although this remedy would require measures to control
, possible short-term risks related to its implementation, the
Agency's analysis indicates that all of these risks can be
satisfactorily controlled. Additionally, any short-term risks
appear heavily outweighed by the long-term effectiveness and
degree of permanence this remedy would provide. The Agency
believes this remedy would avoid the long-term uncertainties
associated with land disposal.
The remedy selected by the EPA for Times Beach and the
Minker/stout/Romaine Creek site includes excavation of soils
exceeding 20 ppb at Times Beach and thermal treatment of the
excavated soils from both Minker/Stout/Romaine Creek and Times
Beach in a temporary thermal treatment unit to be constructed at
Times Beach. All areas at Times Beach with residual dioxin
levels above 1 ppb will be covered with a minimum of one foot of
clean soil. The selected remedy also includes demolition and
onsite disposal of the structures and debris at Times Beach.
Interim storage of contaminated soils at the Minker/stout
Romaine Creek site does not represent a final remedy of this
. material. . The storage facilities are not designed for permanent
management of dioxin-contaminated soils, and could eventually
fail resulting in release of contaminants into the environment.
Final management consisting of treatment or disposal of'this
material is necessary to assure long-term protection of human
health and the environment. The Agency has determined that
thermal treatment of this material at a temporary facility
locat~d at Times Beach satisfies remedy selection criteria under
, CERCLA to a greater extent than the other alternatives evaluated.
The selected remedy will include construction of a ring
levee to protect the thermal treatment facility from a 100-year
flood. A thermal treatment unit will be temporarily located in
the flood-protected area to treat contaminated soils from Times
Beach and Minker/Stout/Romaine Creek. The northwest section of
Times Beach has been identified as a potentially advantageous
location for the thermal treatment unit because construction of
the facility in this location will minimize visibility from
Interstate 44 and reduce the impact on 'upstream or downstream
flood heights. The actual location of the thermal treatment
unit will be determined during the design phase. It is the
Agency's intent to minimize visibility of the facility from
Interstate 44 and local residences. The local community will
have an opportunity to provide comments on the proposed location
prior to development of the final design. '
Delisted ash from the thermal treatment process will be land
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- ..
disposed on site according to the provisions of RCRA Subtitle .D
and the Missouri Solid Waste Management law and regulations. A
portion of the delisted ash may be used in combination with clean
soil as backfill material, if in accordance with these solid
waste management requir~ments. ' All excavated areas within Times
Beach will be backfilled with a minimum of one foot of clean
soil, or to original grade in areas where excavation exceeds one
foot. In addition, all areas with residual dioxin concentrations
above 1 ppb will be covered with ~ minimum of one foot of clean
soil. . '
The selected remedy also includes demolition and onsite land
disposal of uncontaminated structures and debris located within
Times Beach. This action is described as Alternative 2 for
uncontaminated structures and debris in the Times Beach
Feasibilitv Study. The volume of the structures and debris may
be reduced by baling or air curtain destruction in accordance
with state requirements, if approved by the state. One or more
solid waste disposal units will be designed and constructed for
disposal of. this material in accordance with substantive
provisions of RCRA subtitle D and the Missouri Solid Waste
Management Law and regulations. Among other requirements, any
solid waste disposal facility constructed in a floodplain must be
designed to prevent floodwater from contacting the solid waste.
The'actual design of the solid waste disposal facility will be
determined in consideration of site-specific and remedy-specific
factors.
It is the intent of EPA to prioritize the disposal of the
most visible of the structures and debris at Times Beach. Design
and construction of the solid waste disposal facility for the
structures and debris at Times Beach will commence immediately
upon ROD signature. Demolition and disposal of the structures
and debris located in uncontaminated areas will begin as soon as
the disposal facility is ready to accept this material. The
uncontaminated portion of Times Beach which will be addressed
initially generally includes the area south of Interstate 44, and
the area north of the interstate and south of Blakey Road and
Lewis Road. This will result in the removal and disposal of the
structures and debris most visible from Interstate 44. The
cleanup of structures and debris located in contaminated areas
will be performed following removal of contaminated soil in order
to avoid the additional cost of protective equipment.
.
Prior to construction of the ring levee., all soil exceeding'
20 ppb will be removed from the construction area, utilizing the
standard protocol EPA has developed for dioxin-contaminated soil
sampling and excavation. This removed material will be
temporarily stored onsite pending availability of the flood-
protected thermal treatment unit. Temporary storage will take
place in accordance with appropriate RCRA provisions. All
excavated portions of the construction area will be backfilled
with at least one foot of clean material, or to original grade in
areas where excavation exceeds 1 foot. A one-foot soil cover
will be placed over all portions of the construction area with
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residual dioxin levels exceeding 1 ppb, and less than 20 ppb.
Additional fill will be placed, graded, and compacted as
necessary to facilitate implementation of the selected remedy.
The primary source of clean fill material for construction
of the ring levee, backfill, and soil cover will be the former
mobile home park area. Soil sampling has verified that this
portion of the site is free of dioxin contamination. The
excavation of this area will create a potential location for land
disposal of all or a portion of the delisted ash resulting from
thermal treatment or the uncontaminated structures and debris, if
solid waste disposal facility requirements can be met in a cost-
effective manner. Another potential source of borrow has been
identified immediately adjacent to Times Beach, south of
Interstate 44. Following completion of the ring levee, the floor
slabs and temporary structures will be constructed within the
flood-protected area to site the thermal treatment facility and
ancillary equipment. .
A RCRA Part B permit for the thermal treatment unit will be
required from the state prior to mobilization of the unit to
Times Beach. Public participation is an important component of
the RCRA permitting process. RCRA' permits can be issued for
periods up to, but not exceeding ten (10) years according to
federal regulations (40 CFR 270.50). It is anticipated that the
project. can be completed within six (6) years. EPA will
therefore seek to permit the thermal treatment unit for a
duration of six years.
The thermal treatment unit will then be transported to the
site for assemb~y and startup operations. A trial burn will be
performed prior to full-scale operation to generate data required
by the RCRA Part B permit and for the delisting petition for the
treatment residue (ash). During the trial burn, the dioxin
destruction and removal efficiency and the effect~veness of the
safety features will be verified.
An action level of 20 ppb has been established
Beach on the basis of recommendations from CDC. It
that 13,600 cubic yards of soil at Times Beach will
removal in order to meet this action level.
for Times
is estimated
require
Contaminated soil to be transported from the
Minker/stout/Romaine Creek site to Times Beach for treatment
includes approximately 5,800 cubic yards of material previously
excavated, and an estimated 6,200 cubic yards that will be
excavated from the stout area and from Romaine Creek.
Approximately 66,600 cubic yards of soil from the other
identified eastern Missouri sites may eventually be removed and
transported to Times Beach for treatment. Of this 66,600 cubic
yards of soil, 29,000 cubic yards is currently containerized and
in temporary storage at the nearby Castlewood and Quail Run sites
(an additional 5,800 cubic yards is in interim storage at the
M/S/RC site).
3~
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A detailed transportation plan will be developed in
coordination with the local community prior to final design.
This plan will evaluate potential transportation routes to Times
Beach in consideration of the locations of schools, hospitals,
and other public facilities. The transportation plan will also
address transportation schedules and evaluate opportunities to
reduce the risk of traffic accidents. Dioxin-contaminated
materials will be transported only during non-peak hours. Local
officials will' be given an opportunity to participate in its
development, including an opportunity to comment on draft
versions of the plan. The comments and concerns of the local
community will be considered in development of the final
transportation plan. '
The existing pavement covering roadways at Times Beach
may be left intact during implementation of the remedial action,
depending on design of the remedy. This would not result in the
same degree of concern for the stability of the soil layer as for
in-place containment alternatives incorporating impermeable
membranes as previously described. The stability of the soil
layer covering the pavement would be greater than that of a soil
layer covering an impermeable barrier because of the opportunity
for drainage. Due to the deteriorated condition of the macadam
in most areas, infiltration through the pavement would not be
,completely restricted. Pavement widths throughout Times Beach
are also much narrower than the width of the impermeable membrane
evaluated for in-place containment alternatives. Since drainage
will generally not be restricted by the existing pavement) the
stability of a soil layer covering the pavement will not be
adversely impacted.
, Following thermal treatment of the designated soils, the
thermal treatment facility will be demobilized and permanently
removed from the Times Beach site. It is ,anticipated that
thermal treatment of soil from the twenty-six (26) sites.
designated in Table 1 can be completed within six (6) years from
issuance of the RCRA Part B permit. All temporary structures
constructed for the thermal treatment facility and ancillary
units will be dismantled and removed from the site. The ring
levee, gravel, and crushed stone placed during implementation of
the remedial action will be removed. All floor slabs remaining
from thermal treatment activities will be broken up and left in
place. A minimum one-foot vegetated soil cover will be placed
over all demolished floor slabs constructed within the flood-
protected project area. Upon establishment of vegetation, all
site offices wi1! be demobilized. Access restrictions imposed
during cleanup could then be removed enabling beneficial usage of
the site.
The remedy selected for Times Beach represents a final remedy
for dioxin-contaminated soils and uncontaminated structures and
debris located at the site. An additional investigation will be
performed to characterize ground water and other organic
contamination which has been identified at an isolated portion of
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the former city park. It is appropriate for this investigation
to proceed independent of the dioxin remediation, due to the
relative magnitude of the dioxin contamination problem and the
fact that the two problems and their solutions are not
interrelated.
If, during implementation of the remedial action at
Times Beach, thermal treatment of contaminated soils located in
the former city park area is determined to be necessary and
consistent with CERCLA remedy selection criteria, the thermal
treatment unit located onsite may be considered for this action.
This would constitute a separate remedial action requiring
compliance with the CERCLA remedy selection process, which
includes public notice and comment. No other material from any
location not listed in Table 1 will be considered for treatment
at Times Beach.
In certain areas following implementation of the selected
remedy, dioxin concentrations up to 20 ppb will remain at depth,
beneath a minimum of one foot of clean soil. The soil cover
provides both an additional protective barrier and an effective
means of diluting contaminated subsurface soils in the event of
future soil disturbance.
Because unrestricted use of the site would not be allowable,
the 5-year review provision of SARA, Section l2l(c), would apply.
This review will evaluate the continued effectiveness of th~
remedy and determine if land use remains acceptable to federal
and state health agencies. The evaluation will alsa determine
whether continued land use restrictions are warranted and whether
existing land use restrictions will remain effective for an
additional five year period. Additional actions will be taken,
as necessary, to maintain the effectiveness of the remedy.
Ongoing operation and maintenance requirements would include
periodic inspections to verify that" future land use" remains
consistent with the intended site usage based upon the degree of
cleanup. " Inspections would also be directed at identifying
widespread areas of soil disturbance or removal. The areas
requiring periodic surveillance may be designated to facilitate
identification. Seasonal maintenance would include mowing,
fertilizing, and control of erosion.
Large-scale removal or disturbance of soils at Times Beach
following implementation of the selected remedy could potentially
result in concern for protection of human "health and the
environment. Small isolated breaches in the soil "cover would not
be of concern due to the negligible impact on overall average
surface concentrations. In the event that future periodic site
surveillance identifies areas where widespread soil disturbance
or removal of soil has occurred, an evaluation will be conducted
in consultation with appropriate health agencies to determine if
corrective measures are necessary. "
Mi
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XI.
STATUTORY DETERMINATIONS
Based upon available information, the selected remedy
satisfies the remedy selection requirements under CERCLA, as
amended by SARA and the National contingency Plan. The remedy
provides protection of public health and the environment,
achieves all applicable or relevant and appropriate requirements,
is cost-effective, utilizes permanent solutions to the maximum
extent practicable, and satisfies the statutory preference for
remedies involving treatment technologies.
Protection of Public Health and the Environment
The selected remedy for Times Beach and M/S/RC will provide
a high degree of protection of public health and the environment.
No other alternative identified offers an equivalent degree of
long-term protection. The remedy exceeds the level of cleanup
recommended for Times Beach by state and Federal health agencies,
as described in January 16, 1987 correspondence from EPA to CDC.
The existing 4-party contract between FEMA, the state of
Missouri, st. Louis County, and Times Beach for the permanent
relocation of Times Beach residents and businesses provides an
effective legal mechanism to assure that land use at Times Beach
will remain consistent with Federal and state health advisories.
In addition, the Missouri Registry of Confirmed Abandoned or
Uncontrolled Hazardous Waste Disposal Sites requires that the
Director of MDNR must approve any request to change the land use
of a site appearing on the registry. -Local -zoning ordinances may
be e~tablished which will provide additional assurances that land
use remains consistent with the level of cleanup, and that local
interests are considered prior to a change in land use.
The primary environmental concern at Times Beach is the
potential release of dioxi~-contaminated soil or sediment into
the Meramec Riyer. Existing sediment and biota data indicate
that Times Beach is not presently a significant source o£ dioxin
into the Meramec River. Any future environmental threat will be
controlled by removal of all soils exceeding 20 ppb and placement
of a one-foot soil cover over all areas exceeding 1 ppb.
Construction of the spur levee project will be completed in the
fall of 1988. The spur levees will control water velocities
during flood events, which will minimize the potential erosion of
soils and provide protection of the soil cover. These measures
will insure that Times Beach does. not become a source of dioxin
into the Meramec River and will also provide-an additional
measur~ of protection for onsite wildlife.
Attainment of ARARs
It is anticipated that the selected remedy will achieve the
provisions of every applicable, or relevant and appropriate
requirement (ARARs) for the protection of public health and the
environment. Requirements to be met prior to thermal treatment
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of soil include demonstration of six-nines destruction and
removal efficiency and delisting of the thermal treatment
residue. Prior experience by the Agency with the EPA mobile
incinerator in southwest Missouri has indicated that both of
these requirements are achievable.
Containment alternatives would not meet all identified
applicable or relevant and appropriate requirements.
. Alternatives which leave existing .levels of contamination beneath
a cap or soil cover would not meet relevant and appropriate
landfill closure requirements under RCRA. Alternatives involving
the land disposal of contaminated soils in a facility constructed
.at Times Beach would not meet siting requirements under the
Missouri Hazardous Waste Management Law and its implementing
regulations. It is possible that the Missouri Hazardous Waste
Management Law may allow substitution of 30 feet of underlying
clay with a synthetic barrier which provides an equivalent level
of control. A waiver from the state regulation against siting a
hazardous waste landfill in a lOa-year floodplain has not been
identified. Measures to remove the facility from the floodplain
would be required to implement containment alternatives in
accordance with all identified ARARs.
Preference for Treatment
The selected remedy satisfies the statutory preference
(established by SARA) for remedies involving treatment which
result. in the permanent reduction of the volum~, toxicity, or
mobility of hazardous substances. .Thermal treatment destroys the
dioxin contamination, thereby eliminating the toxicity of the
treated soil. Since the dioxin contamination in the treated soil
is destroyed, the potential mobility of this contamination is
also eliminated. The mobility of the soils above 1 ppb remaining
in place following removal of soils exceeding health-based levels
for designated non~residential usage is controlled by the
placement of a vegetated soil cover. All containment alternatives
evaluated reduce the mobility of the contaminated soil, although
not to the extent provided by thermal treatment. containment
alternatives do not reduce the toxicity or the volume of
hazardous substances.
Cost Effectiveness
In establishing sufficient treatment capacity to manage
contaminated soils from other eastern Missouri dioxin sites,
substantial economies of scale will be realized, resulting in a
cost-effective comprehensive remedy for the identified eastern
Missouri dioxin sites. .
The total cost of the remedy is largely dependent upon the
actual unit cost of thermal treatment. Thermal treatment cost
estimates from sources within and outside the Agency have ranged
from less than $200 per cubic yard to over $1,000 per cubic yard.
Based upon the best available information within the Agency, and
uj
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an evaluation of projected thermal treatment costs included in
the Times Beach Feasibilitv study, a unit cost of $400 per cubic
yard for operation of the treatment unit is used to estimate the
cost of the proposed remedy. The cost of associated requirements
such as flood protection, soil. handling and preparation, and ash
disposal are additional and increase the total projected unit
treatment cost. These costs are consistent with estimates used
for evaluation at other Superfund sites, including Love Canal.
The total estimated cost of .the entire project potentially
includes the cost of excavation, transportation, treatment, and
monitoring for soils from all identified eastern Missouri sites
listed in Table 1. The costs associated with excavation,
transportation and monitoring are known with a high level of
confidence because of EPA's extensive experience with these
activities at similar dioxin sites. The potential total cost for
the cleanup of all identified sites is approximately $118.2
million. The costs associated with the current remedy being
selected in this Record of Decision for Times Beach and
Minker/stout/Romaine Creek alone will be approximately $48.8
million.
Although this Record of Decision discusses all of the dioxin
sites listed in Table 1, decisions about the cleanup of each site
will be made separately. The proposed remedy includes transport
of contaminated soils from the Minker/Stout/Romaine Creek site to
Times Beach for treatment, and excavation and treatment of
contaminated soils located onsite at Times Beach. The thermal
treatment unit mobilized for the remedial action will also be
available to accept contaminated soil .from the designated sites
for treatment and disposal. Excavation and transportation of the
soils from each designated site will be evaluated on a site-by-
site basis, and funding and implementation will occur
independently for each site.
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ATTACHMENT 1
HEALTH ADVISORIES
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION VI!
725 MINNESOTA AVENUE
KANSAS CITY, KANSAS 66101
JANlo S7
Dr. Renate D. Kimbrough
Center for Environmental Health
U.S. Centers for Disease Control
Atlanta, Georgia 3U333
OFFICE OF
THE REGIONAL ADMINISTRATOR
Dear Dr. Kimbrough:
Region VII and the State of Missouri are in the process of developing
a comprehensive cleanup strategy for many of the dioxin sites in Missouri.
The purpose of this letter is to request your concurrence with the cleanup
strategies being considered for the Missouri dioxin sites.
To some extent, it is possible to group some Missouri dioxin sites
which represent simil~r exposure scenarios. Similar cleanup considerations
would apply to the sites within each group. Other sites represent .unique
situations where a site-specitic cleanup approach is appropriate. Special
considerations may be warranted at sites with close proximity to streams
or pastures used for grazi ng, and some cOlTmerci a 1 areas may requi re speci a 1
consideration due to a high potential for frequent a~cess by children.
A general discussion of the cleanup protocols being proposed for the
various ~rouped and indivi.dual sites follows.
. Residential (includes Lacy Manor, Bliss-Ellisville, Castlewood, Erxleben,
and residential portion of Highway 141 Access Road)
These sites became contaminated as a result of contaminated waste oil
being applied to the surface for purposes of dust control. The concentration
of 2,3,7,~-TCDO in soils at these sites can be expected to decrease with
depth. These sites represent scenarios where a relatively high degree of
exposure could be anticipated if remedial measures are not implemented.
The proposed cleanup at these sites involves excavation and removal
of surface so;ls exceeding an average concentration of one part per
bi1 lion (ppb), initially determined prior to excavation at the 9~ percent
confidence level using the established sampling protocol. Excavation of
soil would proceed until a residual concentration of 1 ppb is reached
following removal of the initial layer of soil, or until a residual
concentration of 5 to 10 ppb is reached at a depth of approximately one
foot or greater. No excavation would continue beyond' four feet total
de'pth or once bedrock is encountered.
Excavated areas would be backfilled to original grade with appropriate
material. If there are any contaminated subsurface soils at 5 to 10 ppb
at a depth of one foot or more which might be disturbed in the future,
the clean backfill would serve to cover the residual contamination sufficiently
that any contaminated soil that 'is brought to the surface would not
represent a level of concern for public health.
/11
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2
It would not in all cases be necessary to determine residual concentrations
following excavation to the 95 percent confidence level using the established
protocol. In some instances, it can be demonstrated that excavation to a
particular depth effectively reduces resi~ual concentration levels to an
acceptable range. This determination can be made based on information
developed during ~revious removal actions involving the excavation of
TCDO-contaminated soil in Missouri. An evaluation of the relationship
between the preliminary surface TCUD concentration and residual TCDD levels
subsequent to various depths of excavation has made it possible to accurately
estimate the required de~tn of excavation to meet cleanup criteria. Some
limited sampling would still be performed following excavation in order
to allow health officials to certify that the site can be removed from the
state hazardous waste site registry. This limited sampling e'ffort would be
greatly reduced in scope relative to the 95 percent confidence level protocol.
Non-Residential Sites with High Exposure Potential (includes Baxter Garden Center,
Community Christian Church, Manchester Methodist Church, East North Street,
and residential portion of East Texas Motor Freight)
Although these sites are generally not considered to represent residential
scenarios, a sufficient degree of exposure potential exists that the cleanup
approach described above for residential sites is applicaDle. Nursery schools
are operated at the two churches, and a publ)c school is located near the
East North Street site. Site activity at Baxter Garden Center may involve
some direct contact of workers with potentially contaminated surface soils.
Several residences are located directly across the street from the East Texas
Motor Freight site. .
Remediation of tnese sites would involve determining the s~rface TCDD
concentrations at the 9~ percent confidence level. Surface soils exceeding
1 ppb TCDO would be excavated using the same criteria established for
residential areas. Excavation would proceed until one of the following is
achieved: a, residual concentration of 1 ppb TCDD following removal of
the initial layer of soil, a residual concentration of 5-10 ppb at a depth
of approximately one foot or greater, maximum depth of four feet, or bedrock
encounter_d. Excavated areas would be backfilled to the original grade
using appropriate material.
Uccupational/lndustrial Sites (include Bull Moose Tube, Hamill Transfer,
Jones Truck Lines, Overnite Transport, Southern Cross Lumber. Arkansas Best
Freiyht, Bonifield Brothers Trucking, and non-residential por.tions of East Texas
Motor Freight and Highway 141 access road)
These sites represent scenarios where a limited amount of exposure occurs
on an infrequent basis due to normal site activity. The existing extent and
levels of surface TCDO contamination would be determined at the 95 percent
confidence level. In areas where worker contact with contaminated soil does
not occur on a regular basis, it would be acceptable for average surface TCDD
levels up to 20 ppb to remain in place. Areas exceeding 20 ppb would De
excavated until a residual concentration of less than 20 ppb would be reached.
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4
Contamination of Times Beach is primarily limited to road surfaces
throughout the area. The proposed cleanup involves the removal of macadam
or pavement from ali roaaways within Times Beacn. Tnis wiii effectively
remove the up~er severai incnes of the contaminated soils at the site.
Following surface removal. sam~ling will be performed to determine the
levels and areal extent of any residual contamination using the ~5 percent
.confidence level protocol. Areas with average concentrations exceeding
2U ppb wi 11 be further excavated to a total depth of one foot. All
roadways and any other excavated areas will then be bacKfilled to original
grade with appro~riate material and revegetated. Monitoring and maintenance
will be performed to maintain the vegetative cover in contaminated portions
of the site in areas where excavation has not acnieved the level of cleanup
described above for residential, sites. If a non-residential land usage is
desiynated by the State in the future, monitoring and maintenance will be
performed in areas where TCDD levels exceed the appropriate level of concern
for the designated land usage.
Piazza Road
This site represents a combination of residential. agricultural. and
commercial land usage. Due to the prevailing residential usage and
potential for children to have frequent access to non-residential areas,
the cleanup of the entire Piazza Road site will be performed in accordance
with the approach described above for residential sites.
~liss-Frontenac
Although not located in a residential area, special considerations
are warranted for this site. This area is the former location of mixing
and storage tanKS, which received dioxin-contaminated still bottoms
directly from the source. The site became contaminated as a result of
routine spills and leakage. High TeDO levels have been detected throughout
the site. A stream wnich leads into a residential area is located adjacent
to the site. pue to the high TeDO concentrations detected. areal extent of
these high levels, and proximity of the stream, this site will also be
remediated using the approach described above for residential sites.
Shenandoah Stables
Highly contaminated soils in the riding arena at Shenandoah Stables
were excavated and deposited in what is referred to as the slough area.
TCUD concentrations as high as 1,730 ppb have been detected in this area.
A limited number of soil core samples have been analyzed for TeOD at
approximately one-foot intervals to a depth of five feet in the slough area.
TeDO concentrations have not been above 1 ppb at depths greater than two
feet. However, the vertical and horizontal extent of contamination has
not been completely defined. Due to the high reDO concentrations detected
and unKnown depth and areal extent of contamination, excavation of the slough
area will proceed until a residual concentration of 5 to 10 ppb is reached
at a depth below two feet.. The maximum four-foot depth of excavation
will not be observed due to the high TeDO levels which may be present at depth.
Excavated portions of the slough area will be bacKfilled with appropriate
material. Excavation and restoration of the arena area and non-riding
areas will proceed in accordance with the approach described above for
other horse arenas.
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3
Excavation would not ~roceed beyond a total depth of four feet or upon
encountering bedrock. All excavated dreas would be backfilled with
appropriate material to the original grade.
In certain cases, it may be acceptable to leave TCDD concentrations
higher than 2U ppb in place under a paved surface. Paving would be an
acceptable remedial ~asure at the occupational/industrial sites listed
in this section based on sampling results obtained to date. Monitoring
and maintenance provisions would be required to assure the continued
integrity of the paved surfaces at sites where average TCDD levels exceeding
2u ppb are left in place under pavement.
Because a certain level of contamination would be left in place,
long-term monitoring of these sites would be required. This monitoring
program would ensure that any disturbance or offsite transport of
significant quantities of contaminated soils would be detected so that
corrective measures would be taken. It would also be necessary to ensure
that land use did not change to a situation where higher levels of exposure
could occur.
Due to the proximity of the East Texas Motor Freight site to residences
across the street, installation of a cap would be required as an additional
measure. to red~ce the potential for offsite migration of contaminated soil
and direct contact by nearby residents. The cap would be of appropriate
design and accompanied by a long-term monitoring and maintenance program
to ensure its continued integrity.
Horse Arenas (includes Timberline Stables, Bubbling Springs, Saddle and'
S~ur Arena, and Mid-America Arena)
~outine soil disturbance in riding arenas can be expected to extend to
a greater depth than the above scenarios. Removal of soil to a greater
depth in horse arenas may be warranted due to this co~sideration. Soils
in the riding area of each arena would be initially excavated to a depth
of two feet. Following the initial excavation, residual contamination
levels would be determined. Excavation would continue until a residual
concentration of 5 to lU ppb is reached in the two to four foot depth
interval. Excavation would not extend beyond a total depth of four feet.
Following excavation, the arenas would be restored by backfilling with
. clean material appropriate for construction of horse arenas. All sampling
of the riding area would be performed using the established 95 percent
confidence level protocol. Excavation of non-riding a~eas would proceed to
the extent discussed above for residential areas, to a residual concentration
less than 1 ppb in the up~er foot or 5 to 10 ppb in the one to four foot de~th
interval.
Times Beach
The contaminated portions of Times Beach require special consideration
due to the uncertainty of future land use. The approach described above
for occupational/industrial sites will generally be applied with an additional
measure of ~rotection. .
q~
-------
~
Stout Area
T~e Stout portion cf t~e Minkcr/Stout/Rcmaine Cr~ek site beCJ~e
contaminated 35 a result of TCDO-contaminated sail being used as fill
material to create a level surface for the placement of two mobile nome pads.
It is oelieved that approximately ~~U cubic yards of TCDD-contaminated fill
material were used as part of a much larger amount of fill required to create
this level surface,. It is not known how ,the contaminated soil is distributed
throughout the fill area. For this reason, it cannot be assumed that
concentrations generally decrease with depth, and surface sampling would not
ensure higher concentrations do not exist below the surface. Removal of the
uplJer four feet of existing soil in the fill area would be performed as a
minimum level of remediation, unless a sampling program could be designed and
implemented which demonstrated that TCDO concentrations exceeding 1 ppb are
not present in the upper foot of soil, and TeOO levels exceeding 5 to 10 ppb
are not present in the one to four foot depth interval. Areas adjacent to
the fill area which became contaminated as a result of surface migration of
contaminated soils would be remediated in accordance with the general approach
described for residential areas. These areas would be excavated to a residual
concentration of less than 1 ppb after removal of the initial soil layer,
or ~ to 10 ppb at depths of one to four feet, as determined by surface
sampling using the YS percent confidence level protocol. All excavated
areas wo~ld be backfilled with appropriate material to the original grade.
Since contaminated soils may exist at depths greater than four feet
at this site, a retaining wall or other suitable engineering control would
be re~uired to stabilize the fill area.and prevent potential contaminant
migration. A continued monitoring and maintenance program would be required
to ensure that soil$ below the depth of excavation in the fill area are not
disturbed. Land use restrictions would be necessary to prevent future
construction activities wnich may disturb the remaining fill material. The
need for continued monitoring and land-use restrictions may be eliminated i.f a
sampling program could be designed and implemented which would demonstrate that
significant quantities or c~ncentrations of TCOO-contaminated soil do not
remain in the fill material. If such a sampling program is not feasible or
shows that siynificant TeDO remains in the fill, it may be necessary to excavate
the entire fill area in order to eliminate the need for monitoring ~rovisions
. and land-use restrictions.
Structure Decontamination
Region VII has recently evaluated alternative interior surface
decontamination procedures that may be appropriate for remediation of
non-residential structures. The structures being considered are riding
arenas, stables, and barns which are not tightly enclosed and do not have
recirculating air systems. The proposed approach to the decontamination of
these types of structures would consist of a single thorough decontamination
effort. The procedure would include HEPA vacuuming and detergent washing,
as appropriate, of all contaminated surfaces in the interior of the structure.
It has been our experience in the'region that this procedure will reduce
TeDO concentrations below a level of concern for pUblic health for decontamination
of residences. This procedure should also reduce TeDO levels below a level of
concern for public ~ealth in arenas, barns, and stables.
~J
-------
6
An additional control measure may be appropriate for Mel1s Tavern at
tne Castlewooa site. Because of the condition of this structure and the
~orosity of the interior surfaces, painting or otherwise sealing the
contaminated surfaces may be necessary following cleanup of exterior
contaminated soils to achieve undetectable TCOO levels in dust samples.
Structural decontamination of Mel IS Tavern will be performed in accordance
with procedures developed for residential structures, previously approved
by coe.
Your assistance in the evaluation of these proposed approaches to
the cleanu~ of Missouri dioxin sites is greatly ap~reciated. We anticipate
that you may require additional information to complete your response.
Information regarding these sites has been provided to you and your
associates during our discussions, and additional explanation will be
provided as required. Please contact me at your earliest convenience if
you re4uire additional information.
Sincerely yours,
/5/ 1/16/87
Morri s Kay
Regional Administrator
cc:
John Crellin, MDOH
L i'nda James, MONR
-------
(4-
.::::1
DEPART.\IE,"JT OF H~AL TH &: HL:,\IA,' SERVICES
Public Heai:h Service
Centers for Disease Control.
Atlanta GA 30333
PR..TVILE!::GED A."\'D Ca.'.7IDB."'I'IAL (EY EPA)
January 22, 1987
!ir. Morris Kay
Regional Administrator
U.S. Environmental Protection
726 Minnesota Ave.
Kansas city, Kansas 66101
Agency
Dear Mr. Kay,
. In your letter of January 16, 1987 you outlined a strategy for remedial action
.on the sites that were contaminated with 2,3,7,8 tetratchlorodibenzodioxin
(TCCD) in Missouri in the early 70s. As we have discussed previously, these
sites are either used as residential areas or they represent commercial or
industrial sites. However, some sites need special consideration as you also
point out in detail in your letter.
'1 have carefully reviewed your proposals for the various sites listed.
on the letter and additional discussions I have had 'with your staff, I
determined that the remedial actions proposed in your letter for these
would restore them and they would no longer represent areas of concern
public health. . .
Based
have
sites
for
After remediation no further follow up or inspections would be necessary for
most sites. For some areas the caveats as outlined in your letter such as
permanent zoning restrictions at industrial sites would have to be
implemented. .In addition an inspection program would have to be developed for
a few sites, to assure that any remedial action taken, such as permanent
covers do not become disturbed by future activities. In conclusion if the
contaminated sites are remediated and monitored as outlined in your manag~~ent
plan they would no longer represent a risk to hUman health.
Sincerely yours,
Rtaat. 0, ~6/Ut(r' /fj}
Renate D. Kimbrough, ~.D.
Medical Officer
Diplomate American Board of Toxicology
Center for Environmental Health
-------
. ~..nr"
(4-
"''';:::'1:
DEPARTMENT OF HEALTH & HUMAN SERVICES
Public Health Service
Agency for Toxic Substances
and Disease Registry
Atlanta GA 30333
July 30, 1987
Mr. David Yagoner
Director
Yaste Management Division
EFA VII
Kansas City, Kansas 66101
Dear Mr. Yagoner:
This letter is in response to your request for elaboration on the
mathematics underlying the development of support for the 20 ppb cleanup
level for certain Missou~i dioxin sites as proposed in the letter from
Mr. Morris Kay to Dr. Renate Kimbrough dated January 16, 1987. In
Dr. Kimbrough's January 22, 1987 response she indicated that the proposed
cleanup activities would restore the areas so that ~hey would no longer be
of concern for public health. In the enclosed memorandum from ~r. Vernon
N. Houk, Director, Center for Environmental Health (CEH) dated May 8,
1987, the basic CEH guidance established for these sites was listed. In
" order to provide you with the assumptions and calculations underlying the
CEH guidance I have included the following.material from Dr. Kimbrough.
In 1984", Kimbrough et" al., published a paper which examined the potential
for exposure to TCDD in the environment. Since that time, new info~ation
has become available which appreciably alters the basic assumptions
dealing with both the amount of soil young children ingest and the amount
of absorption of TCDD from Missouri soil within the intestine. It now
appears that the amount of soil ingested by small children is less than 10
grams and is more in the order of 100-2000 mg over a 24-hour period,
(Binder et al., 1986). - Yhile Kimbrough et al., assumed that 30 percent of
TCDD bound to ingested soil was bioavailable, subsequent tests with soil
from different areas in Missouri have shown that 60 to 80 percent of TCDD
may be absorbed following ingestion (McConnell et al., Science
223:1077-1079, 1984). The nature of these changes are essentially
offsetting so that for Missouri soils the 1 ppb concern level in
residential areas has not changed.
It has been established recently that TCDD bioavailability following
ingestion of TCDD contaminated soil varies a great deal and depends on a
variety of factors, such as: "
o
o
o
The concentration of TCDD in the soil;
The length of time the TCDD was in contact with the soil; and
The composition of the soil [Umbreit et al., Science 232:497499
(1986), and Umbreit et al., Sociecy Toxicology meeting abstrac~
1273 (1986)].
,/"
!:.~
-------
Pag(. 2 - Mr. David wagoner
However, the level of concern established by Kimbrough et al., as 1 ppb
for residential areas has not changed because of these findings.
Based on the assumptions presented in the paper by Kimbrough et al., it
can be concluded that soil in residential areas contaminated with 5 to 10
ppb of TCDD would not present a hazard if covered with 12 inches of clean
soil. The rationale being that the clean surface soil would represent a
barrier restricting huma~ access to contact with the contaminated soil.
In the event that the soil was disturbed, the 12 inches of clean soil
would be mixed with contaminated soil and the concentration at the surface
would, at most, reach 1 ppb. Thus, the risk in these areas, even after
mixing of the subsurface contaminated soil with the clean cover soil would
be comparable to that in other residential areas where the concentration
of TCDD is 1 ppb or less at the surface. This approach would be
acceptable in residential areas where the soil has not been physically
disturbed by human activities.
Experience has shown, that concentrations decrease dramatically with depth
in areas where the TCDD was applied to the surface. The 5 to 10
ppb/12-inch cover cleanup level would therefore be appropriate for sites
like Castlewood, Times Beach, and, Piazza Road. The 5 to 10 ppb would not
be acceptable for residential areas where fill has been brought in from
highly contaminated areas and where the levels of contamination may
actually be inverted, resulting in increasing concentrations wi~h depth.
The article of Kimbrough et al., focused primarily on residential
exposure. However, the methods used to assess exposure in other
situations were briefly discussed, (see pages 82-85). Basically the dose
a person will receive depends on his or her activities and the ability of
the TCDD to detach from the soil and enter the body. Thus, at sites which
are not residential, the levels of concern may be different. For instance
at a commercial site: .
o
o
Children would not play on a daily basis;
It would be frequented by adults who would primarily walk through
the area;
It is unlikely that there would be any gardening; and
There might be some short-term exposure during construction.
o
o
Thus, it is reasonable to assume that there would be little or no
exposure. In a worst case scenario, dermal exposure of an adult to 1 gram
of soil 5 times a week for 6 months per year could be assumed.
Although through ingestion of TCDD contaminated soil the amount of TCDD
absorbed can be substantial, this is not true for skin absorption. As
discussed in the paper by Kimbrough et al., (pp. 71-74), the most likely
-------
Page 3 - Mr. David ~agoner
amount that would be absorbed would be 1 percent or less of the TCDD on
the ~oil. Thus, the dose received from one gram of soil containing 20 ppb
(20 ng/gram of soil) on the skin would be 0.2 ng or 200 picograms (pg).
The dose, on a kilogram body weight basis, would be 200 pg divided by
70 kg or roughly 3 pg/kg. However, since for these small concentrations
the cumulative dose is more important than the daily doses, it must also
be considered that the dosing is intermittent and not for a lifetime.
Furthermore, the contamination of the area is not uniform and allowances
would have to be made for the percent of contamination at different
concentrations. .
If only 10 percent of the area were contaminated at a concentration of
20 ppb then contact with contaminated soil would not be 100 percent but
the corresponding fraction thereof (10 percent in this case). Thus, the
daily dose if averaged out over a lifetime, takin~ the above assumptions
of 5 days exposure for 6 months per year for 20 years as a basis, would
result in an average daily dose of 330 femtograms/kg body weight.
Rowever~ if only 10 percent of an area were contaminated at 20 ppb, then
the dose wou14 more likely be one-tenth of that or 33 femtograms/kg.
Thus, such contamination with the exposure scenario outlined above would
represent an acceptable. risk based on the paper by Kimbrough et al.,
(1984)..
It would not, however, be acceptable to leave higher levels of
contaminated soil even with a cover of 12 inches. Leaving such
concentrations higher than 20 ppb could pose a threat to health
general environment if the soil were disturbed in the future.
soil with
and the
Kimbrough et al., (1984), stated that inhalation of TCDD bound on soil was
negligible (pp. 71-72): Some work has recently been advanced that TCDe
volatilizes to some extent from soil (Monsanto data, Schroy et al.).
However this has not been substantiated by others (Yanders et al.), and
only involves the surface area immediately above the 50il but not the
normal breathing zone of people. Furthermore, there is also re-absorbtion
and slight movement into the lower layers of the soil. Particularly, such
exposures would be even more unlikely in areas which have vegetation or
where the surface is covered in some other fashion; In any case,
volatilization of TCDD would not contribute to the overall exposure of
people frequenting the area.
In summary, these proposed levels would not deviate from the general
concept presented and developed in the paper by Kimbrough et al., (1984).
~en the paper was developed all available information on human health
effects was taken into consideration. Since that time additional health
studies have been performed. They have not provided any information which
would suggest that TCee is more toxic to humans than was assumed in 1984.
;'1
-------
,
Page 4 - Mr. David ~agoner
Recently, the infor:ation on h~an health effects was reviewed (K~brough.
R.D., and Houk, V.N., Effects of Chlorinated Dibenzodioxin as Chapter 5 in
Solving Hazardous ~aste Problems, ACS Symposium Series 338. ACS
~ashington, D.C., 1987). Cbloracne and some acute health effects have
been found in highly exposed workers. However, there is no evidence that
low level exposure such as that which might result from TCDD in soil at a
concentration of 1 ppb would result in any acute or chronic clinical or
subclinical effects.
Sincerely
~
yours).
~
-------
ATTA<:HMENT 2
DETAILED COST ESTIMATES
rG'J
~ i
-------
9/27/88
AL TERNAHVE 1
COST SUMMARY
1------------------------------------------------------------------------------------------------1
I I
I 1
1 1
I . ACTIVITY REFERENCE COST 1
I -------- --------- I
I I
I "RCRA" Cap - Times Beach Soils Table A-1 S13,149,000 I
1 I
1 I
I Onsite Land Disposal - Times Beach Table A-2 S7,263,000 I
I Structures and Debris I
I I
1 I
I Offsite Thermal Treatment - Table A-3, A-4. S10,996,000 I
I Minker/Stout/Romaine Creek I
I I
I I
I Offsite Thermal Treatment - Other Table A-3, A-4 180,685,000 I
I Designated Eastern Mi.ssouri Sites -------_uu- I
I I
I Total Cost S112,093,000 I
I I
I I
I I
I I
I Annual 0 & M Cost Table A-1 S284,800 I
I 1
I I
1------------------------------------------------------------------------------------------------1
-------
9/27/80
ALTERNATIVE 2
COST SUMMARY
1-------'-------'----------------------------------------------------------'--'---"---'----'-'--1
I I
I I
I I
I ACTIVITY REFERENCE COST I
I ..----.. --------- I
I I
I Impermeable Cover - Times Beach Soils Table A-5 S11,146,000 I
I I
I I
I Onsite Land Disposal - Times Beach Table A-2 $7,263,000 I
I Structures and Debris I
I I "
I I
I Offsite "Thermal Treatment - Table A-3, A-4 S10,996,000 I
I Minker/Stout/Romaine Creek I
I I
I I
I Offsite Thermal Treatment - Other Table A-3,"A-4 $80,685,000 I
I Designated Eastern Missouri Sites ----..---.--- I
I I
1 Total Cost $'10,090,000 I
I I
I I
I I
I I
I Annual 0 & M Cost Table A-S S284,800 I
I I
I I
1--'-'-'--------'---'--"'-"-'-'--'------'------"----'----------'------------~'-----"'---"---I
-------
9/2i/813
ALTERNATIVE 3
COST SUMMARY
1---------------------------------'---------"-------------------'---------------'------.--------1
I I
I I
I I
I ACTIVITY REFERENCE COST I
I --...--- --.....-- I
I I
I Onsite Land Disposal - Table A-6 $8,183,000 I
j Times Beach Soi ls I
I I
I Onsite Land Disposal - Times Beach Table A-2 S7,263,000 I
I Structures and Debris I
I I
I I
I Offsite Thermal Treatment. Table A-3, A-4 S10,996,000 I
., Minker/Stout/Romaine Creek I
I I
I I
I Offsite Thermal Treatment - Other Table A-3, A-4 $80,685,000 I
j Designated Eastern Missouri Sites .--""-'----- I
I I .
I Total Cost S107,127,000 I
I I
I I
I I
I I
I Annual 0 & M Cost Table A-6 S158,200 I
I I
I I
j---------.------------------------.-------------------------'------------"------------'------'-1
-------
9/27/88
AL TERNA T,I VE 4
COST SUMMARY
100 ---.. ---- -.. 00 - - - -- - - - -- 00 - -- - - ----- - 00 - - - - - 00 - - - - _00 00 00 -- 00 00 -- --- --- 00 -- - - -- -.. - 00 -- --- -- --I
1 I
I I
I I
1 ACTIVITY REFERENCE COST 1
I ------.. 00___00_- I
I I
I Onsite Thermal Treatment - Table A-7, A-9 S24,563,000 I
I Times Beach I
I I
I Onsite Land Disposal - Times Beach Table A-2, S7,263,000 1
I Structures and Debris I
I I
I 1
1 Offsi-te Thermal Treatment - Table A-S, A-9 S17,016,000 I
1 MinkerlStout/Romaine Creek 1
I I
I 1
I Offsite Thermal Treatment - Other Table A-S, A-9 S69,319,000 I
1 . Designated Eastern Missouri Sites ------------- I
1 I
I Total Cost S11S, 161 ,000 I
I I
I I
1 I
I 1
I Annual 0 & M Cost Table A-7 S25,200 I
I 1
1 I
1------------------------------------------------------------------------------------------------1
-------
9/27/88
ALTERNATIVE 5
COST SUMMARY
1"""-...----'.---.-....-...-......--.-...----....-.....--.-.-...-....--...-..-....---..---..--.-1
I 1
I 1
I I
1 ACTIVITY REFERENCE COST I
I -.-...-- .----...- I
I 1
I Onsite Land Disposal - Table A-10, A-12 $13,985,000 1
I Times Beach Soils I
I 1
I Onsite Land Disposal - Times Beach Table A-2 $7,263,000 1
I Structures and Debris I
.1 I
I I
I Offsite Land Disposal - Table A-", A.'2 $2,582,000 I
I Minker/Stout/Romaine Creek I
I I
I 1
I Offs'ite Land Disposal - Other Table A-", A.12 $33,245,000' I
I . Designated Eastern Missouri Sites ...-..----..---- 1
I I
1 Total Cost S57,075,000 I
I I
I I
1 I
1 I
I Annua l 0 & '" Cos t Tab leA. , , $ 1 70 , 000 I
I I
I I
1...-.--'---..-"-...-".-------.-'...-----.-.--.-.-..-...--.-.-.--..-..-.--...-.-......-..--.----'1
-------
9/27/88
Table A-1
ALTERNATIVE 1 - IN-PLACE RCRA CONTAINMENT OF TIMES BEACH CONTAMINATED SOILS
1------------------------------------------------------------------------------------------------1
I I
I I
1 SUMMARY TABLE I
I I
1 TIMES BEACH IN-PLACE RCRA CONTAINMENT COSTS I
I I
I I
I I
I I
I ASSUMPTIONS I
I ----..---.. I'
I ACTI ON LEVEL IS 20 PPB I
I TOTAL AREA EXCEEDING ACTION LEVEL 46,500 SY I
I TOTAL AREA EXCEED I NG 1 PPB 144,530 SY I
I I
I I
1 I
I SUMMARY I
I '\
I NET DISPOSAL COST IS $8,70Q,000 I
I TOTAL CAPITAL COST*" IS $13,100,000 I
I TOT AL ANNUAL o&M COST IS $285,000 I
I DURATION OF ONSITE ACTIVITIES IS 21 MO I
I DURATION OF CONSTRUCTION ACTIVITY IS 19 MO I
I I
I I
I I
I **includes contingencies, permitting and legal, and design costs I
I I
I-----'-------'--------_._---'--------------~-----'-----------------------...--------.------'-----1
-------
Table A-1 (cont.)
9/27/88
TIMES BEACH INPLACE RCRA CONTAINMENT CAPITAL COSTS
--------------------------------------------------
--------------------------------------------------
COST ITEM DESCRIPTION
QUANT ITY UN ITS
UNIT COST
TOT AL COST
----..----------.---.-...----..-..---.......-..-.--..
-.----....
......... ..............
...... ................
GENERAL
Mobilization, Demobilization, Bonding, LS 8X $455,071
and Insurance
Community Relations 23 1140 16,000 $138,000
Security Guards and Trailer 23 Me 16,500 $149,500
Health and Safety Preparations1
~orker Physicals 100 EA S60D 160,000
~orker Training 50 EA $1,100 $55,000
Site Health and Safety1
Nurse and Safety Supervision 19 MO $37,800 $718,200
Personal Protective Equipment 1 LS $364,500 $364,500
Decontamination
Decon Trailer 19 1140 $1,000 $19,000
Vehicle Decon Station 1 LS $57,000 $57,000
Decontamination Personnel 19 MO $38,000 $722,000
Disposal of Contaminated Materials 1327 DRUMS $130 "72,529
Construction Administration Trailer 21 1140 1620 $13,020
Monitoring
Background Air Monitoring 1 LS $20,000 S20,000
Ambient Air Monitoring - 8 Monitors 19 MO S25,600 $486 , 400
Sample/Analyze Debris for TCDD 50 . EA S300 S15,OOO
Sampling/Analysis to Guide Constructi 1500 EA S300 $450,000
1 Included in RCRA CAP INSTALLATION -.-.....-..-.-
SUBTOTAL $3,895,220
SITE PREPARATION AND CONSTRUCTION
Site Access
Fences and Gates 16430 LF $12 $197,160
Access Roads 1 LS S264,DOO S264,OOO
Utility Connections and ~ater Supply 1 LS $40,000 $40,000
Construction of Long-term Site Security 1 LS $7S, 000 S7S, 000
Decontamination, & Storage Facilities
Runoff Protection 19 He S24,700 $469,300
Remove Vegetation 46500 SY SO.37 S17,205
Clear and Chip Obstructing Trees 14 AC $4,950 169,300
Bale and Store Chips and Brush 2076 CY S52.50 $109,008
Generator Plant, Light Towers 21 1140 S5,400 S113,400
Install Groundwater Monitoring ~ells 6 EA $2,408 S14,448
-------
SITE CONTAINMENT WORK
Pulverize Existing Roads
Keconstruct Culverts
uust (;ontrol
RCRA CAP INSTALLATION
Cap Materials
Vegetated Top Layer
vegetation, Mulch,
24 inch Soil Layer
Installation
Hydroseed
Middle Drainage Layer
Geotextile Fabric
12 inches Drainage Gravel
Gravel Placement
Geotextile Fabric
Low Permeability Bottom Layer
60 mil Hypalon Synthetic Membrane
Geotextile Fabric
1 foot Bedding Layer
Soil Placement
Cap Installation Cexcl. earthwork)
1987 Cost Adjustment
SOIL COVER OVER AREA£
'CEED I NG 1 PPB
12 inch Soil Layer
Installation
Vegetation, Mulch, Hydroseed
1987 Cost Adjustment
INPLACE CONTAINMENT SUBTOTAL
161000
,
19483"
12.0
38,750
38,750
58,125
19,375
19,375
58,125
523,125
58, 125
'9,375
19,375
523,125
32,677
32,677
20.3
9X
Sy
LS
SY
AC
CY
CY
SY
CY
CY
SY
SF
SY
CY
CY
SF
9X
CY
CY
AC
'5.04
'S8,~jO
SO.05
'1,100
'3.10
S 1. 00
S3.10
'10.50
S1.00
S3.10
'1.00
S3.10
.'3.10
S1.00
'1.20
'3.10
, '1. 00
S1,100
"....-..-..-..---
'1,368,821
sa11,440
S58,230
S9,/42
""---..-..----
sa79,412
S13,210
S120,125
S38,750
S180,188
'203,438
S19,375
S180,188
S523,125
S180,188
$60,063
S19,375
$627,750
'194,920
........-----.....-
'2,360,692
S101,298
S32,677
S22,280
S14,063
-----------
'170,317
-------------
-------------
sa,674,462
-------
Bid Contingencies 15..0% 51,301,169
Scope Cont i ngenc i es 15.0% 51,301,169
----..-------
TOTAL CONSTRUCTION COST 511,276,801
rmitting and Legal 3.0% 5338,304
,~vices During Construction 7.0% 5789,376
------------
TOTAL IMPLEMENTATION COST 512,404,481
Engineering Design Cost 6.0% $744,269
------------
------------
TOTAL CAPITAL COST FOR ALTERNATIVE 1 513,149,000
TIMES BEACH INPlACE CONTAINMENT lONG-TERM ANNUAL 0 & M COSTS
===============================================================================================
COST ITEM DESCRIPTION
FREQUENCY
YEARLY COST
---------------------
....-------
-----------
OPERATION AND MAINTENANCE
Clear Culverts
Maintain Security Systems
Mowing
Reseed & Rework Eroded or Exposed Areas
Annua II y
Semiannually
$1,995
S643
51,400.
528,387
_PECTI ON AND MaN /TOR I NG
Site InspectiOns
Groundwater Monitoring
Site Runoff
Perimeter Air Monitoring
Security Patrols
Month l y
Semiannually
Quarterly
Quarterly
Daily
$4,000
523,600
550,000
550,000
516,800
..------.-..------
SUBTOTAL lONG-TERM ANNUAL 0 & M COST
5176,825
Administrative Costs
Contingency Costs
Insurance and Taxes
Maintenance Reserve-
10 percent
30 percent
5 percent
517,683
$53,048
sa,841
528,387
----------------
----------------
TOTAL ANNUAL 0 & M COST FOR ALTERNATIVE 1
$284,800
-------
Table A-2
TIMES BEACH, MISSOURI
ONSITE LAND DISPOSAL
UNCONTAMINATED STRUCTURES AND DEBRIS
9/27/813
Sampling and Analysis
$358,000
Demol ition
Structure Demolition
General Debris
Decontamination Personnel
$2,044,000
$72,000
Bal ing Faci l ity
General
Site Preparation
Baler Facility Construction
. Operation and Maintenance
Decontamination Facility
'153,000
$4 , 000
'290,000
$100,000
Disposal
Transport
Placement
Cover Construction
$180,000
$60,000
$935,000
Site Restoration
$294,000
---.---------
Construction Subtotal
$4,490,000
. Bid Contingencies (20X)
Scope Contingencies (20X)
$898,000
$898,000
---.---------
Total Construct.ion Cost
$6,286,000
Permitting and Legal (2X)
Services During Construction (7X)
$126,000
$1.40,000
-------.-----
TOTAL IMPLEMENTATION COST
16,852,000
Engineering Design Cost (6X)
$411,000
---..---------
TOTAL CAPITAL COST
$7,263,000
-------
9/27/88
Table A-3
CENTRALIZED THERMAL TREATMENT OF SOilS FROM DESIGNATED
EASTERN MISSOURI SITES (EXCLUDING TIMES BEACH)
HUMBER OF SAMPLING/ AIR
SOIL EXCAVATION INCINERATION TRANSPORT CLEANUP ANALYTICAL MONITORING TOTAL
VOLUME, COST COST HAUL COST SECTI ONS COST COST SIT E
(a) (b) (c) MILES (d) (e) (f) (g) COST
, 1--------_...._-----------1-..----1-------------1------------1-----1-----------1--------1-----------1-'----------1-------------1
I I ' I I I I I I I I I
I RESIDENTIAL I I I I I I I I I I
, ! ----....--- I I I I I I I I I I
1 Stout Area I 1,900 I SO 1 51,609,900 I 20 I S76,000 1 18 I 542,400 I S10,100 I $1,738,000 I
I Romaine Creek 1 4,300 1 $0 I $3,643,500 1 20 1 S361,200 I 36 I $84,800 I S22,900 I 54,112,000 I
I Lacy Manor I 600 I 5252,000 I $508,400 I 20 I S50,400 I 6 1 S14,300 1 S3,200 I SS28,OOO I
I Bliss Ellisville I 7,000 I 52,940,000 1 55,931,300 I 20 1 $588,000 I 71 I S166,900 I S37,300 I $9,664,000 I
I Comm. Christian Church I 550 I S231,OOO I 5466,000 I 20 I 546,200 I 6 I 513,100 I S2,900 I S759,OOO I
I Manchester Meth. Church I 300 1 S126,000 1 5254,200 I 20 I S25,200 I 3 1 $7,200 1 S1,600 I 5414,000 I
I Eureka'East North Street 1 750 I S315,000 I 1635,500 1 20 1 S63,~00 I 8 I S17,900 I 54,000 I S1,035,OOO I
I Baxter Garden Center I 1,500 I 1630,000 I S1,271,000 I 20 I S126,000 I 15 I 535,800 1 SS,OOO I S2,071,000 I
I 1-------1 ---.---- 1 -------- I I -------- 1--------1------.'---1------------\---"--------1
I subtotaL 116,900 I 54,494,000 IS14,319,800 I IS1,336,OOO I 171 I 5402,900 I S90,100 I $20,643,000 :
I I I I I I 1 I I I I
1 I 1 1 1 1 I I 1 1 'I
I 1 I I 1 I I I 1 ' I I
I I I I I 1 I 1 1 I I
1 RESIDENTIAL/COMMERCIAL I. I I I I I I I I I
I "---.",-""---""-- I 1 1 I I I 1 1 I I
I Highway 141 Access Road I I ° I I 1 I, I I /, I
I residentiOal 1 5?0 I S218,400 1 5440,600 I 20 I 543,680 I 5 I 512,400 I, $2,800 I $718,000 I
comnercial I 100 I, 542,000 I $84,700 1 20 1 SS,400 1 1 I S2,400 I S500 I S138,OOO'1
<1st Tex~s Motor Freightl I I I 1 I 'I I I I
I residential I 700 I S294,000 1 S593,100 I 20 I S58,800 I ,71 $16,7001 $3,700 I $966,000 I
I comnercial 1 300 I S126,000 I $254,200 1 20 I S25,200 I 3 I S7,200 I 51,600 I 5414,OOO!
I 1-------1 '-------- I -------- I 1 -----... 1------"1----""---1'''----':-.-1-'-----------1
I subtotaL I 1,620 1 5680,400 I S1,372,600 1 I S136,080 I 16 I $38,600 I SS,600 I $2,236,000 I
I I I I I' I I " I I
1 1 I I I 1 1 I I I I
I I I 1 I I, I I I I I
I NON-RESIDENTIAL I I 1 'I I 1 II! I
I ..----......--- 1 I I 1 1 I I 1 1 I
I Bull Moose Tube I 300 r $126,000 I S254,200 I 40 I S50,400 I 3 I S7,200 I S1,600 I 5439,000 I
I Hamill Transfer I 1,800 I $756,000 1 S1,525,200 I 20 I S151,200 I 18 I 542,900 I S9,600' 52,485,000 I
I Jones Truck Lines I 1,000 I 5420,000 1 $847,300 I 20 I $84,000 I 10 1 $23,800 I S5,300 I $1,380,000 I
I avernite Transport I '''1 1 1 20 I I". 1 ... I -.. I .-- 1
I Southern Cross Ll.IICer 11,300 1 S546,000 I S1,101,500 1 20 I S109,200 I '13 I S31,000 I 16,900 I S1,795,OOO I
I Times Beach I 0 I SO I 50 I I 1 0 I SO I $0 I $0 !
I Arkansas Best Freight I ..- I I I 20 1 I --- I ... I --,' 1 --- I
I Bonifield Bros Trucking I 2,100 1 S882,000 I S1,779,400 I 20 1 $176,400 1 '21 I S50,100 1 S11,200 I $2,899,000 I
I ' 1---"..1 --...--- I -......- I I .--..-.- I-...-...j.....".-'-I-.......'---I-----'--.----j
I subtotaL I 6,500 1 S2,730,000 I S5,507,600 1 I $571,200 I 66 I S155,000 I $34,600 I $8,998,000 I
I I II I I I I I, I !
I-"-----".---------'.---I--..-.-j'--"----".-I---'--------1---.-1-------.'.'1--'.-..'1'.."'.----1--.....-."-1------------- I
SITE NAME
..,
-------
Table A-3 (cont.)
1-------------------------1-------1-------------1-------~----I-----I-----------I----'---I---------'-I------------1--'----------1
I I I I I I I I I I I
I HORSE ARENAS SITES I I I I I I I I I I
I ----..----..---..- I I I I I I I I I
I Tirrberline Stables 11,600 I $672,000 I S1,355,700 1140 I 5940,800 I 16 I S38,100 I $8,500 I S3,015, .1
I Bubbling Springs Arena I 2,780 I S1,167,600 I S2,355,600 I 20 I 5233,520 I 28 I $06,300 I ,.4,800 I S3,838,000 I
I Saddle and Spur Arena 1 2,550 I S1 ,1m ,000 I $2,160,700 1 20 I S214,200 I 26 I $60,800 I S13,600 I S3,520,000 J
I Shenandoah Stables I 3,300 I S1,386,000 I S2,796,200 I 60 I S831,600 I 33 I S78,700 I S17,600 I S5,110,000 I
I Piazza Road I 7,800'1 S3,276,000 I $6,609,200 I 70 IS2,293,200 I 79 I S186,000 I 541,600 I S12,406,000 I
I Bliss Frontenac I 750 I S315,000 I $635,500 I 20 I $63,000 I 8 I S17,900 I 54,000 I S1,035,000 I
I ,---.-.-, -------- I -------- I I .------- I----'---j----'------I------------I-------------I
I subtotal 118,780 1 S7,887,600 IS15,9'2,900 I 154,576,320 1 190 I 5447,800 I S100,100 1 S28,925,000 I
I I I I I I I I I I I
I I I I I I I I I I I
I I I I I I I I I I I
I I I I I I I I I I I
t REMOVAL SITES (h) I 1 I I I I 1 i I I
I -....-------- I I 1 I. I I I I I I
I Castlewood 113,000 I (included IS11,015,300 I 20 I S520,000 I ... I ..- I H- I S11,535,000 I
I Minker, Minker Neighborsl 4,400 I in past 1 S3,728,200 I 20 I S176,000 I I I , S3,904,000 I
I Cashel Residence I 1,000 I costs) 1 $847,300 I 20 I 540,000 I .-- I --- I ..- I S887,000 I
I Sullins Residence 1 400 I I $338,900 1 20 I S'6,000 I ... I --- I -.. \ S355,000.J
I Quail Run 116,000 I l$n,557,300 I 20 I $640,000 I .-- I --. I -.. I S14,197,000 I
1 1-------1 -------- I ----.--- I I .-----.- \----'---1"------'-"1------------1------'------'
I subtotal 134,800 I 1$29,487,000 I IS1,392,000 I .-- I --- I -.. 1 S30,879,000 ,
I I I I I I 1 I 1 I I
I I I I I I II! I I
I 1======= 1 ========== I ========== I I =:.!======== I I r I I
I I . I 1 I I I i I I I
I TOTAL 178,600 I S15,792,000 1$06,600,000 I 1$8,012,000 I 443 IS1,044,000 I S233,000 I S91,681, ,I
. I I I 1 'I I I I I I
j------------------------'---------------"-------------.---_._-------.-~----------_.---.----------------------------------.---1
(a) Revised estimates ,reflect volune adjustments if contaminated areas which were not originally sprayed with
contaminated waste oil (areas contaminated due to surface migration) require excavation to an average depth
of 6 inches to achieve cleanup criteria. Sprayed areas are excavated to an average depth of one foot.
Horse arenas excavated to an average depth of two feet, horse arena areas outside arena excavated to 1 foot,
Shenandoah slough ('00 x '00 ft) to 4 feet.
(b) Based on Missouri' dioxin contract cost 5420~00 per cubic yard.
Romaine Creek and Stout excavation costs from Operable Unit Feasibility Studies.
(c) Offsite treatment cost is $847 per cubic yard.
(d) Transport cost assumed per cubic yard-mile is S2.10 per cubic yard-mile, except as noted.
(e) Based on average 4,000 square foot sections,except Stout (known) and Romaine Creek (3 10-foot wide sections
along creek), plus 5GX additional to verify perimeter clean.
(f) Costs represent actual sampling and analytical costs during eastern Missouri. removal actions, assuming
8 total 50-aliquot samples per cleanup section at S294 per sample collection/analysis.
(g) Air monitoring costs assune S320 per sample, 5 monitors per site, 1 sample per 3 days per monitor, 100 cubic
yards per day excavated. 10 monitors assumed for Piazza Road. .
(h) Transport costs from Times Beach FS. Soil volunes represent actual volunes in storage.
-------
9/27/88
Table A-4
NET THERMAL TREATMENT COSTS FOR DESIGNATED EASTERN MISSOURI SITES
(EXCLUDING TIMES BEACH SOILS)
1-- - -- ---- - --- --- -- --- -- - - - - - - - - -- - - - - -- --- - -- - - -- -- -- eo - - -- -- - ---- ---- -- - --_e- -- - - - -- -e - -- - - - - --I
I THERMAL TREATMENT COSTS I
I I
I ASSUMPT IONS I
I ----------- I
I INCINERATION COST PER CUBIC YARD (CY) IS Sl,00 I
I INCINERATOR CAPACITY (CY/HR) IS 4.25 I
I TOTAL ONSITE SOIL VOLUME (CY) IS 0 I
I OFFSITE CONTAINERIZED SOIL VOLUME IS 34,800 I
I ~DITIONAL OFFSITE SOIL VOLUME (CY) IS 43,800 I
I EFFICIENCY IS 70~ I
I I
I I
I SUMMARY I
I I
I NET TREATMENT COST IS Sl,2,700,OOO I
I TOTAL CAPITAL COST1 IS $66,600,ODO I .
I. TREATMENT TIME (MONTHS) IS 36.7 I
I TOTAL CUBIC YARDS IS 78,600 I
I NET TREATMENT COST PER CY IS S543 I
I TOTAL CAPITAL COST PER CY IS $847 I
I I
I I
I TOTAL ANNUAL 0 & M COST IS I
I . I
1 I
I 1includes contingencies, permitting and legal, and design costs I
I------e_------------------------------------------~-----------------------------------------'----1
-------
Table A-I. (cant.)
CFFSITE THERMAL TREATMENT FACILITY
---------------------------------
CCST ITEM DESCRIPTION QUANTI TY UN ITS UNIT CCST TCTAL CCST
--------------------------------------------- ---.---. ---------- .-...---....--
GENERAL
Mobilization, Demobilization, Bonding, LS 8% $714,768
and Insurance
Community Relations 85 MC $6,000.00 $254,100
Full RCRA Part B Permit 1 LS $500,000.00 $500,000
Security Guards and Trailer for Incin. 73 HO $6,500.00 $1.72,500
Health and Safety Preparations
~orker Physicals 100 EA $600.00 $60,000
~orker Training 50 EA $1,100.00 $55,000
Site Health and Safety
Nurse and Safety Supervision 24 MC $25,200.00 $60'4,800'
Personal Protective Equipment/lncin. 1 LS $258,750.00 $258,80'0
Decontamination
Decon Trai ler 24 MC $1,000.00 $24,000
Vehicle Decon Station 1 LS $57,000.00' $57,000'
Decontamination Personnel 24 HO $37,800.0'0' $90'7,200'
Construction Trailer Rental 73 MC S620.00 $1.5,10'0'
Monitoring Activities
Background Air Monitoring 1 LS $1.3,700 $1.3,700
Ambient Air Monitoring - 4 Monitors 24 HO $12,800 $30'7,200'
Test for TCDD in Removed Vegetation 12 EA $300' $3,600'
--------...-
SUBTCTAL $1.,30'7,768
S(TE PREPARATICN AND CONSTRUCTION
Site Access
Fences and Gates 2100' LF $14.00 $29,40'0'
Road Improvements (onsite) 1 LS $50'0,0'00' $$00,000
Road Improvements (offsite) 1 LS $500,000 $500,000
Utility Upgrading & Connections 1 LS $1.0,000.00 $1.0,00'0
Fine Grading, Gravel Surfacing 24200' SY $5.50 $133,10'0
Liquid' Storage Faci! ities 1 LS $500,000.00' $500',000'
Building Floor Slabs
Building Floor Slabs 39380' SF $5.35 $210',700'
Liquid Storage Slabs 30'0'00' SF $17.70' $531,000'
Staging Area 117500 SF 5.35
Ash Storage Area (2 week capacity) 20000' SF 5.35 $10'7,000
Bui ldings
130 x 236 Incinerator Building LS $150,000.00' $150',000
60 x 145 Shredder Building LS $26,000.0'0' $26,00'0
130 x 236 Staging Building LS $150,000.00 $150,0'00'
Utility Upgrading and Connections LS $92,0'0'0'.0'0' $92,0'0'0'
Cutdoor Lighting LS $20,0'0'0'.0'0' $20',0'0'0'
-------
Ditching tor Site Runon, Pumping 1 LS $41,900.00 $4 1 , 900
Floor Slab. Staging Area 1 17'500 SF S5.35 1628,600
130 x 236 Staging Bldg (3 wk capacity) 1 LS S150,000 S150,000
-----..-.-.
SUBTOTAL S3,809,700
NCINERATOR SETUP AND OPERATION
Startup/Shakedown 1 LS S300,000.00 S300,OOO
Test Burn/Ash Delisting 1 LS S700,000.00 S700,OOO
Load/Transport/Unload Onsite Soil 0 Cy S2.00 SO
Operation 78600 Cy $400.00 S31,440,OOO
Ash Removal, Fill Onsite, Compact 78600 Cy S20.00 S1,572,000
-......-------
SUBTOTAL S34,012,OOO
INCINERATOR SITE RESTORATION
Incinerator Demobi l ization
Remove Buildings and Auxiliaries
Remove 6 inches Gravel and Dispose
Regrade Site
Topsoil Placement (Ottsite Borrow)
Erosion Matting
Seeding and Revegetation
1 LS S125,000.00 S125,000
1 LS S50,000.00 S50,000
4500 Cy S19.00 185,500
24200 SY S3.40 182,300
4500 CY S 13.50 160,800
24200 SY SO.80 S19,400
24200 SY $4.50 S108,900
------...----
SUBTOTAL S531, 900
----------------
----------------
$42,661,368
ONSITE THERMAL TREATMENT SUBTOTAL
,d Contingencies
Scope Contingencies
20X 18,532,300
25X S10,665,300
......-------
161,858,968
3% S865,400
n S2,019,300
------------
164,743,668
6X S1,903,900
----------
----------
S66,M7,568
TOTAL CONSTRUCTION COST
Permitting and Legal
Services Ouring Construction
TOTAL. IMPLEMENTATION COST
Engineering Design Cost
TOTAL CAPITAL COST
-------
9/27/88
Table A-5
ALTERNATIVE 2 - IMPERMEABLE BARRIER AND SOIL COVER OVER TIMES BEACH CONTAMINATED SOILS
1------------------------------------------------------------------------------------------------\
I I
I I
I SUMMARY TABLE I
I I
I TIMES BEACH IN-PLACE CONTAINMENT COSTS I
I I
I. I
I I
I I
I ASSUMPTIONS I
I . ------eo--- I
I ACTION LEVEL IS 20 PPB I
I TOTAL AREA EXCEEDING ACTION LEVEL 46,500 SY I
I TOT AL AREA EXCEED I NG 1 PPB 144,530 SY I
I I
I I
I I
I SUMMARY I
I I
I NET OISPOSAL COST IS $7,400,000 I
I TOTAL CAPITAL COST** IS $11,100,000 I
I TOT AL ANNUAL o&M COST IS $285,000 I
I DURATION OF ONSITE ACTIVITIES [S 17 MO I
I DURATION OF CONSTRUCTION ACT[VITY IS 15 MO I
I I
I **includes contingencies, permitting and legal, and design costs I
I I
I I
I I
1------------------------------------------------------------------------------------------------1
-------
9/27/88
Table A-5 (cont.)
TIMES BEACH INPLACE CONTAINMENT CAPITAL COSTS
---------------------------------------------
---------------------------------------------
COST ITEM DESCRIPTION
QUANTI TY
UNITS
UN IT COST
TOTAL
...-----------.-----------------------------
---.......--
---------
GENERAL
Mobilization, Demobilization, Bonding, LS 8X $410,703
and Insurance
Community Relations 19 MO 16,000 S114,000
Security Guards and Trailer 19 Me 16,500 S123,500
Health and Safety Preparations1
Worker Physicals 100 EA 1600 160,000
Worker Training 50 EA $ 1 , 100 S55,000
Site Health and Safety1
Nurse and Safety Supervision 15 MO S37,800 S567,000
Personal Protective Equipment 1 LS $364,500 $364,500
Decontamination
Decon Trai ler 15 MO S1,000 S15,000
Vehicle Decon Station 1 LS S57,000 S57,000
Decontamination Personnel 15 Me $38,000 S570,000
Disposal of Contaminated Materials 1327 DRUMS S130 $172,529
Construction Administration Trailer 15 Me 1620 $9,300
Monitoring
Background Air Monitoring 1 LS S20,000 $20,000
Ambient Air Monitoring - 8 Monitors. 15 Me S25,600 $384,000
Sample/Analyze Debris for TCDD 50 EA S300 S15,000
Sampling/Analysis to Guide Constructi 1500 EA S300 $450,000
---------.
SUBTOTAL $3,387,532
SITE PREPARATIPN AND CONSTRUCTION
Site Access
Fences and Gates 16430 LF $12 $197,160
Access Roads 1 LS $264,000 $264,000
Utility Connections and Water. Supply 1 LS $40,000 $40,000
Construction of Long-term Site Security 1 LS S75, 000 S75, 000
Decontamination, & Storage Facilities
Runoff Protection 15 MO $24,700 $370,500
Remove. Vegetation 46500 SY SO.37 $17,205
Clear and Chip Obstructing Trees 14 AC $4,950 169,300
Bale and Store Chips and.Brush 2631 CY S52.50 S138,128
Generator Plant, Light Towers 17 MO S5,400 S91,800
Install Groundwater Monitoring Wells 6 EA S2,408 S14,448
------..-
$1,277,541
SITE CONTAINMENT WORK
Pulverize Existing Roads 161000 SY $5.04 $811,440
Reconstruct Culverts 1 LS S58,230 S58,230
Dust Control 194837 SY SO.05 S9,742
.-------
$879,412
-------
COVER/MEMBRANE INSTAllATION
Cover Materials
Vegetated Top layer
Vegetation, Mulch,
12 inch Soil layer
Installation
Hydroseed
Impermeable Bottom layer
60 mil Hypal~ Synthetic Membrane
Geotextile Fabric
1 foot Bedding layer
Soil Placement
Cap Installation (excl. earthwork)
1987 Cost Adjustment
SOil COVER OVER AREAS EXCEEDING 1 PPB
12 inch Soil layer
Installation
Vegetation, Mulch, Hydroseed
1987 Cost Adjustment
INPlACE CONTAINMENT SUBTOTAL
Bid Contingencies
Scope Contingencies
TOTAL CONSTRUCTION COST
Permitting and legal
Services During Construction
TOTAL IMPLEMENTATION COST
Engineering Design Cost
TOTAL CAPITAL COST FOR ALTERNATIVE 2
12.0
19,375
19,375
523,125
58, 125
19,375
19,375
523,125
9X
32,677
32,677
20.3
9X
TIMES BEACH INPlACE CONTAINMENT lONG-TERM ANNUAL 0 & M COSTS
AC
CY
CY
$1,100 513,210
$3.10 160,063
$1.00 519,375
$1.00 $523,125
$3.10 $18Q,188
$3.10 160, 063
$1.00 $19,375
$1.20 1627,750
$135,283
......-----
$1,638,431
SF
SY
CY
CY
SF
CY
CY
AC
$3.10
51.00
$ 1 , 100
5101,298
532,677
522,280
514,063
--..----
$170,317
$7,353,232
15.0X $1,102,~
15.0X $1,102,985
--------
$9,559,201
3.0X
7.0X
5286,776
$069,144
--------
510,515,121
6.0X
1630,907
--------
--------
511,146,000
===========================================================================================================
COST ITEM DESCRIPTION
---------------------
OPERATION AND MAINTENANCE
Clear Culverts
Maintain Security Systems
Mowing
FREQUENCY
---------
Annua II y
Semi annua II y
YEARLY COST
----------..
51,995
1643
51,400
-------
Reseed & Rework Eroded or Exposed Areas
INSPECTION AND MONITORING
Site Inspections
Groundwater Monitoring
Site Runoff
Perimeter Air Monitoring
Security Patrols
SUBTOTAL LONG-TERM ANNUAL 0 & M COST
Administrative Costs
Contingency Costs
Insurance and Taxes
Maintenance Reserve
TOTAL ANNUAL 0 & M COST FOR ALTERNATIVE 2
$28,387
Monthly
Semi amua II y
Quarterly
Quarterly
Dai ly
14,000
$23,600
$50,000
$50,000
$16,800
----------------
$176,825
10 percent
30 percent
5 percent
$17,683
$53,01,8
$8,841
$28,387
----------------
----------------
$284,800
-------
9/27/88
Table A-6
ALTERNATIVE 3 . ONSITE LAND DISPOSAL OF TIMES BEACH CONTAMINATED SOILS
1".---'..--"'..----'---'.------------'----------'-.---...----------.---.---------..---....------..--..-..----I
I I
I I
I I
I TIMES BEACH ONSITE LAND DISPOSAL FACILITY COSTS I
I I
I I
I I
I ASSUMPTIONS I
I ----------. I
I TIMES BEACH ACTION LEVEL IS 20 PPB I
I TIMES BEACH SOIL VOLUME IS 13,600 CUBIC YARDS I
I I
I I
I I
I I,
I SUMMARY I
I I
I TOT AL . CLEARED AREA IS 5,000 SQUARE YARDS I
I FACILITY BASE AREA IS 3,000 SQUARE YARDS I
I SOIL PLACEMENT PERIOO IS PERIOO IS 5 MONTHS .\
I TOTAL CONSTRUCTION PERIOO IS 18 MONTHS I
I I
I I
I TOTAL DISPOSAL COST.. IS $8,200,000 I
I EXCAVATION COST IS $5,712,000 I
I AIR MONITORING COST IS $165,385 I
I SAMPLING/ANALYTICAL COST IS $369,556 . I
I -.......-..... I
I TOTAL CAPITAL COST IS 514,446,941 I
I I
I .1
I TOTAL ANNUAL o&M COST 15 $158,000 I
I I
I.-includes contingencies, permitting and legal, and design costs I
I I
1---'.'.----"-----'...--"..-------------------------..--------..----.--.....------.....-.-.....----..--------I
-------
Table A-6 (cont.) 9/27/88
ONSITE LAND DISPOSAL CAPITAL COSTS
.._---*-_.*--*----*.*.*-
NERAL
Mobilization, Demobilization, Bonding, LS 8.00% $358,528
and Insurance
Community Relations 29 HO $6,000 $174,000
RCRA Part B Permit 0 LS $500,000 $0
Security Guards and Trailer 18 HO $6,500 $117,000
Construction Trailer Rental 18 HO $620.00 $11,200
Health & Safety
Worker Physicals 50 EA $600 $30,000
Worker Training 25 EA $1,100 $27,500
Site Health & Safety
Nurse & Safety Supervision 10 HO $37,800 $378,000
Personal Protective Equipment 1 LS $45,400 $45,400
Decontamination
Decon Trailer 10 HO $ 1 ,000 $10,000
Vehicle Decon Station 1 LS $57,000 $57,000
Decontamination Personnel 10 HO $37,800 $378,000
Monitoring Activities
Background Air Monitoring 1 LS $43,700 $43,700
Air Monitoring 10 MO $12,800 $128,000
Test for TODD in Removed Vegetation 2 EA $300 $600
Monthly Leachate Samples 10 HO $9,600 $96,000
-------------
S1,854,928
TE PREPARATION AND CONSTRUCTION
Site Access
Fences & Gates 300 LF $14 $4 , 200
New Roads and Road Improvements 1 LS $500,000 $500,000
Offsite Road Upgrading 1 LS $500,000 $500,000
Uti l ity Upgrading & Connections 1 LS $40,000 $40,000
Install Groundwater & Monitoring Wells 6 EA S2,488 $14,900
Clear Brush & Debris, Remove to Storage 5,000 SY S1 $5,000
Regrade, C~ct 5,000 SY $2.38 $11,900
Outdoor Lighting 1 LS $20,000 $20,000
Ditching for Site Runon 300 LF $0.56 $200
-------------
$1,096,200
ONSITE DISPOSAL FACILITY
Base
Base Preparation and Underdrain 3000 SY $9.68 $29,000
Base Concrete and Liner 3000 SY $69. 00 $207,000
Leachate Collection Layer 3000 SY $7.69 $23,100
Leak Detection Layer 3000 SY S14.45 $43,400
Sidewalls 500 SY $158 S79,OOO
Cover 3000 SY $35 $105,000
Sidewall Backfill Layer 1 LS $89,400 $89,400
Collection Systems 1 LS $59,500 $59,500
Placement of Waste
Bulldozers (2), Sheepsfoot Roller 13600 CY $4 $54,400
Physical Soils Lab Trailer 5 HO $5,000 $25,000
Lab Technicians (2), Surveyors (2) 5 HO $30,100 $150,500
-------
Leachate Treatment Facility
Sumps, Piping, Trenches
Site Preparation
Foundation, Building, & Ancillaries
Installed Treatment System
Land Application System
Operating Materials and Power
Operating Labor
ONSITE DISPOSAL SUBTOTAL
Bid Contingencies
Scope Cont i ngenc i es
TOTAL CONSTRUCTION COST
Permitting and Legal
Services During Construction
TOTAL IMPLEMENTATION COST
Engineering Design Cost
TOTAL CAPITAL COST
ONSITE LAND DISPOSAL LONG-TERM ANNUAL 0 & M COSTS (ALT. 3)
1
1
1
1
1
10
10
S129,855 S129,900
S28,149 S28,100
S141,966 S142,000
S517,704 S517,700
S15,000 S15,OOO
S5,000 S50,OOO
S14,100 S141,000
_..--e___..__--
S1,889,000
.---......-...---.
S4, 84(), 000
20.0% S968,000
25.0% S1,210,000
------------..
S7,018,000
3.0% S210,500
7.0% S491 ,300
-------------
S7,719,800
6.0% S463,200
=============
18,183,000
LS
LS
LS
LS
LS
MO
MO
===============================================================================================================
COST ITEM DESCRIPTION .
.. --.......-......-.. --............
OPERATION AND MAINTENANCE
Cover Regrading/Reworking
Security System Maintenance
Leachate Collection & Leak Detection Main
Leachate 1reatment Plant 0 & M
Maintain Runon/Runoff Control Systems
INSPECTIONS AND MONITORING
Site Inspections
Groundwater Monitoring
Leachate and LeaK Monitoring
Security Patrols
SUBTOTAL LONG-TERM ANNUAL 0 & M
Administrative Costs
Contingency Costs
Insurance and Taxes
TOTAL
FREQUENCY
YEARLY
COST
---------
Annua II y .
Semi amUa II y
Periodic
Periodic
Semi annua II y
$15,000
S1,500
S14,800
S7,500
S2,300
Monthly
Semi annua II y
Periodic
Daily
S18,000
S23,600
S9,600
S16,800
----------..-----
S109,100
10
30
5
S10,900
S32,700
S5,500
percent
percent
percent
----------------
S49,100
----------------
----------------
.S158,200
-------
9/?7/88
Table A-7
NET TIMES BEACH THERMAL TREATMENT COSTS
TIMES BEACH AND M/S/RC SOILS ONLY
1------------------------------------------------------------------------------------------------1
I THERMAL TREATMENT COSTS 1
.1 I
I ASSUMPT IONS I
I ------..--- I
I INCINERATION COST PER CUBIC YARD (CY) IS $400 I
1 INCINERATOR CAPACITY (CY/HR) IS 4.25 I
I TOTAL ONSITE SOIL VOLUME (Cn IS 13,600 I
1 OFFSITE CONT.AINERIZED SOIL VOLUME IS 12,000 1
I ADDITIONAL OFFSITE SOIL VOLUME (Cn IS 0 I
I EFFICIENCY IS 70% 1
I 1
I I
1 SUMMARY I
I I
I NET TREATMENT COST IS $21,500,000 1
I TOTAL CAPITAL COST1 IS $34,600,000 I
I TREATMENT TIME (MONTHS) IS 12.0 I
1 TOTAL CUBIC YARDS IS 25,600 1
I NET TREATMENT COST PER CY IS $840 I
I TOTAL CAPITAL COST PER CY IS $1,352 1
II
1 I
I TOT AL ANNUAL 0 & M COST IS $25,20.0 1
I I
I 1
1 1includes contingencies, permitting and legal, and design costs 1
I" ---- - -. - -- - - - -- -- - - -.. --... - -- ---.. - -... - - - - - -- -- --..- - - -- -- -- - - - - - - -- - -- -- --- - --...... -- --. -.1
-------
Table A-7 (cont.)
TIMES BEACH
ONSITE THERMAL TREATMENT FACILITY
TIMES BEACH SOILS
.. -.. -- --.. -.. -.. -..... --- --........ --...................
GENERAL
Mobilization, Demobilization, Bonding, LS 8X 5799,068
and Insurance
Community Relations 48 MO 16,000.00 $143,850
Full RCRA Part B-Permit 1 LS $500,000.00 5500,000
Security Guards and Trailer for Incin. 36 MO 16,500.00 $233,700
Health and Safety Preparations
Worker Physicals 100 EA 1600.00 160,000
Worker Training 50 EA S1,100.00 $55,000
Site Health and Safety
Nurse and Safety Supervision 12 MO $25,200.00 $301,200
Personal Protective Equipment/lncin. 1 LS $258,750.00 $258,800
Decontamination
Decon Trai ler 12 MO S1,OOO.00 S12,OOO
Vehicle Decon Station 1 LS $57,000.00 $57,000
Decontamination Personnel 12 MO $37,800.00 $451,800
Construction Trailer Rental 36 MO 1620.00 $22,300
Monitoring Activities
Background Air Monitoring 1 LS $43,700 $43,700
AIICient Air Monitodng - 4 Monitors 24 MO $12,800 $307,200
Test for TCDD in Removed Vegetation 4 EA S300 S1,200
..---------
SUBTOTAL $3,246,818
SITE PREPARATION AND CONSTRUCTION
Site Access
Fences and Gates 2100 LF $14.00 $29,400
Road Improvements (onsite) 1 LS $500,000 $500,000
Road Improvements (of!site) 1 LS 5500,000 $500,000
Utility Upgrading & Connections 1 LS $40,000.00 $40,000
Ring Levee - 5 acres protected (~orps) 1 LS $2,200,000 $2, 200,000 -
Fine Grading, Gravel Surfacing 24200 SY $5.50 5133, 100
Liquid Storage Facilities 1 LS 5500,000.00 S500,000
Building Floor Slabs
Building Floor Slabs 39380 SF $5.35 $210,700
Liquid Storage Slabs 30000 SF $17.70 5531,000
Staging Area 117500 SF 5.35
Ash .Storage Area (2 week capacity) 20000 SF 5.35 5107,000
Buildings
130 x 236 Incinerator Building 1 LS $150,000.00 5150,000
60 x 145 Shredder Building 1 LS 526,000.00 526,000
130 x 236 Staging Building 1. LS 5150;000.00 5150,000
Utility Upgrading and Connections 1 LS 592,000.00 592,000
OUtdoor Lighting 1 LS 520,000.00 $20,000
Ditching for Site Runen, Pumping 1 LS $13,700.00 513,700
Floor Slab, Staging Area 117500 SF 55.35 1628,600
130 x 236 Staging Bldg (3 wk capacity) 1 LS $150,000 $150,000
----------
SUBTOTAL $5,981,500
INCINERATOR SETUP AND OPERATION
Startup/Shakedown 1 LS $300,000.00 $300,000
Test Burn/Ash Delisting 1 LS 5700,000.00 5700,000
Load/Transport/Unload Onsite Soil 13600 CY $2.00 527,200
Operation 25600 CY $400.00 $10,240,000
-------
Ash Removal, Fill Onsite, Compact
INCINERATOR SITE RESTORATION
Incinerator Demobilization
Remove Buildings and Auxiliaries
Remove 6 inches Gravel and Dispose
Regrade Site
Topsoil Placement (Offsite Borrow)
Erosion Matting
Seeding and Revegetation
ONSITE THERMAL TREATMENT SUBTOTAL
Bid Contingencies
Scope. Cont i ngenc i es
TOTAL CONSTRUCTION COST
Permitting and Legal
Services During Construction
TOTAL IMPLEMENTATION COST
Engineering Design Cost
TOTAL CAPITAL COST
LONG TERM 0&14 COSTS
25600
$20.00
CY
$512,000
....-.......-.
SUBTOTAL
$11,779,200
1 LS $125,000.00 $125,000
1 LS $50,000.00 $50,000
4500 CY $19.00 S85,500
.24200 SY $3.40 S82,300
4500 CY $13.50 $60,800
24200 SY $0.80 $19,400
24200 SY $4.50 $108,900
...-.------
SUBTOTAL $531,900
----------------
----------------
$21,539,418
20X $4,307,900
25X $5,384,900
-----------
$31,232,218
3X S614,400
7X $1,433,600
------------
$33,280,218
6X $1,351,700
----------
----------
S34,631,918
-------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------
Site Inspections
Administrative Costs
Contingency Costs
Monthly
10 percent
30 percent
$18,000
$1,800
$5,400
----------------
----------------
TOTAL
$25,200
-------
9/27/88
Table A-8
THERMAL TREATMENT COST ANALYSIS
ALTERNATIVE 4: CENTRALIZED THERMAL TREATMENT OF SOILS FROM TIMES BEACH
AND DESIGNATED EASTERN MISSOURI SITES
j------------------------------------------------------------------------------------------------1
I . THERMAL TREATMENT COSTS I
I . 1
I ASSUMPTIONS I
1 -----..---- I
I INCINERATION COST PER CUBIC YARD (Cn IS $400 I
I INCINERATOR CAPACITY (CY/HR) IS 4.25 I
I TOTAL ONSITE SOIL VOLUME (Cn IS 13,600 I
I OFFSITE CONTAINERIZED SOIL VOLUME IS 34,800 I
1 ADDITIONAL OFFSITE SOIL VOLUME (Cn IS 43,800 I
I EFFICIENCY IS 70X. 1
I I
1 1
I SUMMARY I
1 I
I NET THERMAL TREATMENT COST IS $51,500,000 I
I TOTAL CAPITAL THERMAL TREATMENT COST' IS $80,700,000 I
1 TREATMENT TIME (MONTHS) IS 43.0 I
I TOTAL CUBIC YARDS IS 92,200 . I
I ONSITE TREATMENT COST PER CUBIC YARD IS $1,352 I
I OFFSITE TREATMENT COST PER CUBIC YARD IS $692 1
I I
I I
I TOT AL ANNUAL 0 & M COST IS $25,200 I
I I
I I
I 1includes contingencies, permitting and legal, and design costs I
,--------------.---------------------------------------------------------~-----------------------I
-------
Table A-8 (cont.)
TIMES BEACH
ONSITE THERMAL TREATMENT FACILITY
EASTERN MISSOURI SOILS
............... ......-........ ---............. ............ --..
GENEi
-------
Ash Removal, Fill Onsite, Compact
INCINtRATOW SITE RESTORATION
Incinerator Demobilization
Remove Buildings and Auxiliaries
Remove 6 inches Gravel and Dispose
Regrade Site
Topsoil Placement (Offsite Borrow)
Erosion Matting
Seeding and Revegetation
ONSITE THERMAL TREATMENT SUBTOTAL
Bid Contingencies
Scope Cont i ngenc i es
TOTAL CONSTRUCTION COST
Permitting and Legal
Services During Construction
TOTAL IMPLEMENTATION-COST
Engineering Design Cost
TOTAL CAPITAL COST
LONG TERM o&M COSTS FOR ALTERNATIVE 4
92200
. S20.00
Cy
S1,844,000
----------
SUBTOTAL
S39, 751,200
1 LS S125,000.00 S125,000
1 LS S50,000.00 S50,000
4500 Cy S19.00 185,500
24200 SY S3.40 182,300
4500 CY $13.50 160, 800
24200 SY SO.80 $19,400
24200 SY $4.50 S108,900
-----------
SUBTOTAL S531, 900
================
$51,523,566
20X S10,304,700
25X $12,880,900
-----------
$74,709,166
3X S1,079,600
]X S2,519,000
--------..---
S78,307,766
6X S2,375,000
----------
----------
180,682,766
-------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------
Site Inspections
Administrative Costs
Contingency Costs
Monthly
10 percent
30 percent
$18,000
$1,800
$5,400
----------------
----------------
TOTAL
S25,200
-------
9127/88
Table A.9
ALTERNATIVE 4: CENTRALIZED THERMAL TREATMENT OF SOILS FROM TIMES BEACH
AND DESIGNATED EASTERN MISSOURI SITES
NUMBER OF SAMPLING/ AIR
SOIL EXCAVATION INCINERATION TRANSPORT CLEANUP ANALYTICAL MONITORING TOTAL
VOLUME, COST COST HAUL COST SECTI ONS COST COST SITE
(a) (b) (c) MILES (d) (e) (0 (g) COST
..:"""'.'.""""""1"""'1""""""""".'"""1""'1"""""'1""""1-"""""1""""""/""""""'1
I I I I 1 I I I I I
RESIDENTIAL I I I II I I 1 1 I
.;......... I I 1 I I I I I I I
.stout Area I 1,900 I SO I S2,568,000 I 19 I S72,200 I 18 I $42,400 I S10,100 I S2,693,000 I
Romaine Creek I 4,300 I SO I S5,811,700 I 19 I S343,140 I 36 I $84,80D I $22,900 I $6,263,000 /
Lacy Manor I 600 1 S252,000 I $415,300 I 26 I $65,520 1 6 1 S14,300 I S3,200 I S750,000 I
Bliss Ellisville 17,000 I S2,940,000 I $4,845,300 I 10 I S294,000 I 71 I S166,900 I S37,300 I SS,284,000 I
: Comm. Christian Church I 550 I S231,000 I S380,700 I 9 I S20,790 I 6 I S13,100 I $2,900 I $648,000 I
I Manchester Meth. Church I 300 I S126,000 I S207,700 I 9 I S11,340 1- 3 I S7,200 I S1,600 I S354,000 I
: Eureka'East North Streetl 750 I S315,000 1 S519,100 I 4 1 S12,600 I 8 I S17,900 I $4,000 I S869,000 I
Baxter Garden Center I 1,500 1 $630,000 1 S1,038,300 I 15 I S94,500 I 15 I S35,800 I $8,000 I S1,807,000 I
1"""'1 ........ I ........ I I .....,.. 1""""1"""""'1""""""1""""""'1
subtotal 116,900 I $4,494,000 1$15,786,100 I I S914,090 I 171 I $402,900 I S90,100 I S21,687,000 1
I I I I 1 1 I I I I
I I I I 1 I I I I I
I I I I I I I I I I
i I I 1 I I I I I I \
I RESIDENTIAL/COMMERCIAL 1 I I I I I I I I I
I ...................... 1 I I I I I I I I I
, Highway 1"1 Access Road I I I I I I. I I I I
I. ..esidential I 520 I $218,400 I S359,900 I 13 I S28,392 I 5 I S12,400 I S2,800 I $622,000 I
1IIIercial I 100 I $42,000 I $69,200 I 13 I S5,46O I 1 I $2,400 I S500 I S120,000 I
. Eas ~~as Motor Freightl . I I I I I 1 I r I
residential I 700 I S294,000 I $484,500 I 26 I S76,440 I 7 I S16,700 I S3,700 I $875,000 I
cOllJl1ercial I 300 I S126,OOO I $207,700 I 26 1 S32,760 I 3 I S7,200 I S1,600 I S375,OOO I
1'.""'1 ........ I ..~..... I I .....,.. 1""""1"""""'1".'."""'1"""."""1
subtotal I 1,620 I $680,400 I S1,121,300 I I $143,052 I 16 I S38,600 1 SS,600 I S1,992,OOO I
I ,. I I I I' I I I -\
I I I I I I I I I I
I I I I I I I I I I
I 1 I I I I I I I I
I I I I I I I I I I
I 300 I S126,000 I S207,700 I 44 I S55,440 I 3 I S7,200 I S1,600 I S398,000 I
11,800 I S756,000 I S1,245,900 I 22 I S166,320 I 18 I $42,900 I S9,600 I S2,221,000 I
11,000 I $420,000 I $692,200 I 27 I S113,400 I 10 I S23,800 I S5,300 I S1,255,000 I
I . . . I I 1 28 I I' . . I . . . I . . . I . . . I
I 1,300 I S546,000 I SS99,800 I 25 I S136,500 I 13 'j $31,000 I $6,900 I $1,620,000 I
113,600 I S5,712,000 IS18,381,300 I 0 I I 138 I S324,300 I S145,100 1 S24,563,000 I
I ... 1 I I 29 I I... I . -- I ... 'I ... I
12,100 I S882,000 I S1,453,600 I 22 I $194,040 I 21 1 $50,100 I $11,200 I S2,591,000 I
1"""'1 ..,..... I ........ I I .....,.. 1""""j""'.""'I"""".."I"".."."" 1
subtotal 120,100 I $8,442,000 IS22,88o,500 I I $665,700 I 204 I $479,200 I S107,100 I S32,575,000 I
I I I I I I I I I I
"'"'''''''''''''.''''''1'''''''1'''''''''''''1''''''''''''1'''''1"""""'I""'."I'.""""'I,,".".""j'''''''''''''1
SITE NAME
NON.RESIDENTIAL
----..-..--------
Bull Moose Tube
Hamill Transfer
Jones Truck Lines
Overnite Transport
Southern Cross Lumber
Times Beach (h)
Arkansas Best Freight
Bonifield Bros Trucking
-------
Table A-9 (cont.)
-------------------------1-------1-------------1------------1-----1-----------1--------1-----------1---------'--1---'-'-------1
I I I I 1 I 1 I I I
1 I 1 I I I I 1 I 1
I I I I 1 I I 1 1 I
1 1,600 1 S672,000 I $1,107,500 I 131 I $880,320. 1 16 1 $38,100 I SS,500 I $2,706,000
12,780 I $1,167,6001 $1,924,300 1 151 $175,1401 281 $66,300 I $14,8001 $3,348,000 I
12,550 I $1,071,000 I $1,765,100 I 41 $42,840 I 261 S60,800 1 $13,6001 $2,953,0001
13,300 1 $1,386,000 1 $2,284,200 1 611 S845,460 I 33 I $78,700 1 $17,600 1 $4,612,000 I
I 7,800 1 $3,276,000 1 $5,399,100 1 68 1$2;227,680 1 79 I $186,000 I $41,600 I $11,130,000 1
I 750 1 $315,000 I $519,100 I 19 1 $59,850 1 8 1 $17,900 I $4,000 I S916,000 I
j-------I -------- I -------- I 1 -------- 1--------1-----------1------------1---'---------1
subtotal 118,780 I S7,887,600 1$12,999,300 I 1$4,231,290 1 190 1 $447,800 1 S100,100 I S25,666,000 I
1 I 1 1 I 1 1 I 1 1
1 1 1 I 1 I I I I I
1 I I I 1 I I I I 1
I I IlL 1 I I I I
I I 1 1 I I I I I I
I I I 1 I 1 I I I I
Castlewood 113,000 1 (included I SS,998,500 I 14 1 $364,000 1 --- I u- I u'l S9,363,OOO I
Minker, Minker Neighborsl 4,400 1 in past 1 S5,946,90"o I 19 1 S167,200 I I I I $6,114,000 1
Cashel Residence I 1,000 I costs) 1 $1,351,600 1 19 I S38,OOO I --- I --- 1 --- I S1,39O,OOO 1
Sullins Residence I 400 I 1 $540,600 I 19 I $15,200 I --- I --- 1 --- I $556,000 1
Quail Run 116,000 I 1'11,075,100 I 15 I $480,000 I --- I u- 1 ..- 1 $11,555,000 I
1-------1 -------- I -------- I 1 -------- 1--------1-----------1--'---------1---'--'---.---1
subtotal 134,800 I 1$27,912,700 I 1$1,064,400 1 --- I --- I ..- I S28,977,OOO 1
I I 1 1 1 1 I I 1 I
1 I I I I I 1 I I I
. I ======= I ========== I. ========== 1 1 ========== I I I 1 I
I. I 1 1 1 1 I I I 1
TOTAL 192,200 1 $21,504,000 ISSO,700,OOO I 1$7,019,000 I 581 IS1,369,OOO I S306,OOO 1$110,898,000
. I 1 I 1 1 I I I. I I
-----.------.---.---------------------.---------------------------------------------------------------.-----------------------,
(a) Revised estimates reflect volume adjustments if contaminated areas which were not originally sprayed with
. contaminated waste oil (areas contaminated due to surface migration) require excavation to an average depth
of 6 inches to achieve cleanup criteria- Sprayed areas are ex~avated to an average depth of one foot.
Horse arenas excavated to an average depth of two feet, horse arena areas outside arena excavated to 1 foot,
Shenandoah slough (100 x 100 ft) to 4 feet. .
(b) Based on Missouri dioxin contract cost $420.00 per cubic yard.
Romaine Creek and Stout excavation costs from Operable Unit Feasibility Studies.
(c) Offsite treatment cost is $692 per .cubic yard; Onsite cost is '1,352 per cubic yard.
(d) Transport cost assumed per cubic yard-mile is $2.10 per cubic yard-mile, except as noted.
(e) Based on average 4,000 square foot sections,except Stout (known) and Romaine Creek (3 10-foot wide sections
along creek), plus 501 additional to verify perimeter clean.
(f) Costs represent actual sampling and analytical costs during eastern Missouri removal actions, assuming
8 total 50-aliquot samples per cleanup section at $294 per sample collection/analysis.
(9) Air monitoring costs assume S320 per sample, 5 monitors per site, 1 sample per 3 days per moni.tor, 100 cubic
yards per day excavated. 10 monitors assumed for Times Beach and Piazza Road.
(h) Excavation cost includes onsite land disposal of structures and debris ($6,836,000) from Times Beach FS.
(i) Transport cqsts from Times Beach FS. Soil volumes actual for all except Castlewood (estimated).
HORSE ARENAS SITES
-...--.-----------
Timberline Stables
Bubbling Springs Arena
Saddle and Spur Arena
Shenandoah Stables
Piazza Road
Bliss Frontenac
REMOVAL SITES (i)
-------..-----
-------
9/27/88
Table A-10
ONSHE LAND DISPOSAL OF CONTAMINATED SOILS FROM TIMES BEACH ONLY
1----------------------------------------------------------------------------------------1
I I
I I
I I
I TIMES BEACH ONSITE LAND DISPOSAL FACILITY COSTS I
I I
I I
I I
I ASSUMPTIONS 1
I uU_-UU- I
I TIMES BEACH ACTION LEVEL IS 20 PPB I
I TIMES BEACH SOIL VOLUME IS 13,600 CUBIC YARDS I
I OFFSITE SOIL VOLUME IS 0 CUBIC YARDS I
I TOTAL SOIL VOLUME IS 13,600 CUBIC YARDS I
I I
I I
I I
I I
I SUMMARY I
I I
I TOTAL CLEARED AREA IS 5,000 SQUARE YARDS I
I FACILITY BASE AREA IS 3,000 SQUARE YARDS I
I SOIL PLACEMENT PERIOO IS PERIOO IS , MONTHS I
I TOTAL CONSTRUCTION PERIOO IS ,{, MONTHS I
I I
I NET DISPOSAL COST IS $4,600,000 I
I TOTAL CAPITAL COST.. IS $7,800,000 I
I TOTAL ANNUAL 0&14 COST IS $49,000 I
I I
I I
I NET DISPOSAL COST PER CY IS $338 I
I TOTAL CAPITAL COST PER CY IS $57{' I
1 I
I I
I.-includes contingencies, permitting and legal, and design costs I
I I
I I
I I
I--------------------------------~-------------------------------------------------------1
-------
Table A-10 (cont.)
ONSITE LAND DISPOSAL CAPITAL COSTS
...*********************
GEH~I(AL
Mooi llZation, Demeoi l ization, Bonding, LS 8.00~ 5341 ,960
and Insurance
Community Relations 25 MO $6,000 5150,000
RCRA Part B Permit 1 LS 5500,000 5500,000
Security Guards and Trailer . 14 140 $6,500 591,000
Construction Trailer Rental 14 140 $620.00 SB,700
Health & Safety
Worker Physicals 14 EA $600 SB,200
Worker Training 7 EA 51,100 57,500
Site Health & Saf~ty
Nurse & Safety Supervision 6 140 $37,800 5226,800
Personal Protective Equipment 1 LS 545,400 545,400
Decontamination
Decon Trailer 6 140 51,000 $6,000
Vehicle Decon Station 1 LS 557,000 557,000
Decontamination Personnel 6 140 537,800 5226,800
Monitoring Activities
Background Air Monitoring 1 LS 543, 700 543,700
Air Monitoring 6 140 512,800 576,800
Test for TCDD in Removed Vegetation 2 EA $300 $600
Monthly Leachate Samples 6 140 59,600 557,600
.. .. .... ."... .... ...... ..
51,848,060
SITE PREPARATION AND CONSTRUCTION
Site Access
Fences & Gates 300 LF' 514 54,200
New Roads and Road Improvements 1 LS 5500,000 5500,000
Offsite Road Upgrading 1 LS 5500,000 5500,000
Utility Upgrading & Connections 1 LS 540,000 540,000
Install Groundwater & Monitoring Wells 6 EA $2,488 $14,900
Clear Brush & Debris, Remove to Storage 5,000 SY $1 55,000
Regrade, C~ct 5,000 SY 52.38 $11,900
Outdoor Lighting 1 LS 520,000 520,000
Ditching for Site Runon 300 LF 50.56 $200
-------------
51,096,200
ONSITE DISPOSAL FACILITY
Base
Base Preparation and Underdrain 3000 SY 59.68 529,000
Base Concrete and Liner 3000 SY $69.00 $207,000
Leachate Collection Layer 3000 SY 57.69 523,100
Leak Detection Layer 3000 SY 514.45 543,400
Sidewalls 500 SY 5158 57'9,000
Cover 3000 SY $35 5105,000
Sidewall Backfill Layer 1 LS SB9,400 SB9,400
Collection Systems 1 LS 559,500 $59,500
Placement of Waste
Bulldozers (2), Sheepsfoot Roller 13600 CY 54 554,400
Physical Soils Lab Trailer 1 140 55,000 55,000
Lab Technicians (2), Surveyors (2) 1 140 $30,100 $30,100
-------
Leachate Treatment Facility
Sumps, Piping, Trenches
Site Preparation
Foundation, Building, & Ancillaries
Installed Treatment System
Land Application System
Operating Materials and Power
Operating Labor
1 LS $129,855 $129,900
1 LS $28,149 $28,100
1 LS $141,966 $142,000
1 LS $517,704 $517,700
1 LS $15,000 $15,000
6 Me $5,000 $30,000
6 Me $14,100 S84,600
--.-----..--.....
$1,672,200
-------------
Sit,616,000
ONSITE DISPOSAL SUBTOTAL
Bid Conting~ies 20.0X $923,200
Scope Cont i ngenc i es 25.0X $1,154,000
-------------
TOTAL CONSTRUCTION COST $6,693,200
Permitting and Legal 3.0X $200,800
Services During Construction 7.0X Sit68,500
-------------
TOTAL IMPLEMENTATION COST $7,362,500
Engineering Design Cost 6.0X Sit41 ,800
-------------
-------------
TOTAL CAp'ITAL COST $7,801.,000
TIMES BEACH ONSITE LAND DISPOSAL LONG-TERM ANNUAL 0 & M COSTS
-----------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------
COST ITEM DESCRIPTION
FREQUENCY
YEARLY
COST
-------------------------------------------------
-------------------------------------------------
---------
---------
--------
--------
OPERATION AND MAINTENANCE
Cover Regrading/Reworking
Security System Maintenance
Leachate Collection & Leak Detection Main
Leachate Treatment Plant 0 & M
Maintain Runon/Runoff Control Systems
Annually
Semiannually
Periodic
Periodic
Semi annually
$15,000
$1,500
$14,800
$7,500
$2,300
INSPECTIONS AND MONITORING
Site Inspections
Groundwater Monitoring
Leachate and Leak Monitoring
Security Patrols
SUBTOTAL LONG-TERM ANNUAL 0 & M
Monthly
Semi amua II y
Periodic
Daily
$18,000
$23,600
$9,600
$16,800
.------..--------
$109,100
Administrative Costs
Contingency Costs
Insurance and Taxes
10 percent
30 percent
5 percent
$10,900
$32,700
$5,500
----------------
Sit9,100
----------------
----------------
TOTAL ANNUAL 0 & M COST FOR ONSITE DISPOSAL FACILITY
$158,200
-------
9/27/88
Table A.11
ALTERNATIVE 5 . ONSITE LAND DISPOSAL OF CONTAMINATED SOILS
FROM TIMES BEACH AND DESIGNATED EASTERN MISSOURI SITES
I""""""""""""-""""-""'-""""'~'"""""""""""-"""""""1
I I
I I
I I
I TIMES BEACH ONSITE LAND DISPOSAL FACILITY COSTS I
I I
I I
1 I
I ASSUMPTIONS I
I .--.,....-- I
I TIMES BEACH ACTION LEVEL IS 20 PPB I
I TIMES BEACH SOIL VOLUME IS 13,600 CUBIC YARDS I
I OFFSITE SOIL VOLUME IS 78,600 CUBIC YARDS I
I TOTAL SOIL VOLUME IS 92,200 CUBIC YARDS I
I I
I !'
I I
I I
I SUMMARY I
I I .
! TOTAL CLEARED AREA IS 36,000 SQUARE YARDS !
I FACILITY BASE AREA IS 19,000 SQUARE YARDS I
I SOIL PLACEMENT PERiOD IS PERIOD IS 9 MONTHS I
I TOTAL CONSTRUCTION PERIOD IS 22 MONTHS I
I I
I NET DISPOSAL COST IS $11,500,000 I
I TOTAL CAPITAL COST**.IS $19,500,000 I
I TOT AL ANNUAL 0&14 COST 15 $53,000 I
I I
I I
I ON5ITE .CAPITAL COST PER CY 15 $574 I
I OFFSITE CAPITAL COST PER CY IS $149 I
I I
I I
I **includes contingencies, permitting and legal, and design costs I
I I
! I
I I
I"-.""...""'."""""'~'.""""""".."""...................................!
-------
Table A-11 (cont.)
ONSITE LAND DISPOSAL CAPITAL COSTS
.***********************
GENERAL
Mobilization, Demobilization, Bonding, LS 8.00% $853,504
and Insurance
Community Relations 33 Me S6,000 $198,000
RCRA Part B Permit 1 LS $500,000 $500,000
Security Guards .and Trailer 22 Me S6,500 $143,000
Construction Trailer Rental 22 Me S620.00 $13,600
Health & Safety
Worker Physicals 92 EA S600 $55,300
Worker Training 46 EA 51,100 550,700
Site Health & Safety
Nurse & Safety Supervision 14 MO 537,800 5529,200
Personal Protective Equipment 1 LS 5308,100 $308,100
Decontamination
Decon Trai ler 14 MO 51,000 $14,000
Vehicle Decon Station 1 LS $57,000 557,000
Decontamination Personnel 14 MO $37,800 $529,200
Monitoring Activities
Background Air Monitoring 1 LS Sl.3,700 Sl.3,700
Air Monitoring 14 MO $12,800 5179,200
Test for TCDD in Removed Vegetation 14 EA $300 SI.,200
Monthly Leachate Samples 14 MO 59,600 $134,400
------------..
$3,613.,101.
SITE PREPARATION AND CONSTRUCTION
Site Access
Fences & Gates 2100' LF $14 529,400
New Roads and Road Improvements 1 lS $500,000 $500,000
Offsite Road Upgrading 1 lS $500,000 $500,000
Utility Upgrading & Connections 1 LS Sl.0,000 Sl.0,000
Install Groundwater & Moni toring Wells 6 EA $2,488 514,900
Clear Brush & Debris, Remove to Storage 36,000 SY 51 536,000
Regrade, COII'p8ct 36,000 SY 52.38 $85 , 700
OUtdoor Lighting 1 LS 520,000 520,000
Ditching for Site Runon 2100 LF 50.56 $1,200
-------------
51,227,200
ONSITE DISPOSAL FACILITY
Base
Base Preparation and Underdrain 19000 SY 59.68 5183,900
Base Concrete and Liner 19000 SY S69 . 00 51,311,000
Leachate Collection Layer 19000 SY 57.69 5146,100
Leak Detection Layer 19000 SY 514.45 5274,600
Sidewalls 3100 SY 5158 Sl.89,800
Cover 19000 SY 535 1665,000
Sidewall Backfill Layer 1 lS S606,100 S606,100
Collection Systems 1 lS Sl.03, 100 Sl.03, 100
Placement of Waste
Bulldozers (2), Sheepsfoot Roller 92200 CY 54 5368,800
Physical Soils lab Trailer 9 MO 55,000 Sl.5,000
lab Technicians (2), Surveyors (2) 9 MO 530,100 5270,900
.~
-------
Leachate Treatment Facility
Sumps, Piping, Trenches
Site Preparation
Foundation, Building, & Ancillaries
Installed Treatment System
Land Application System
Operating ~aterials and Power
Operating Labor
ONSITE DISPOSAL SUBTOTAL
Bid Contingencies
Scope Cont i ngenc: i es
TOJAL CONSTRUCTION COST
Permitting and Legal
Services During Construction
TOTAL I~PLE~ENTATION COST
Engineering Design Cost
TOTAL CAPITAL COST
1
1
1
1
1
11.
11.
LS $259,710
LS $56,298
LS $283,932
LS'1,035,1t08
LS $15,000
140 $5,000
140 $11.,100
$259,700
$56,300
$283 , 900
'1,035,1.00
$15,000
'70,000
$197,1.00
-............--...---
16,682,000
-...-...--..--.---
$11,522,000
20.0X $2,304,1.00
25.0X $2,880,500'
----------......
$16,706,900
3.0X $501,200
7.0X $1,169,500
-------------
$18,377,600
6.0X $1,102,700
-------------
-------------
$19,1.80,000
CENTRALIZED ONSITE LAND DISPOSAL LONG-TERM ANNUAL ° & ~ COSTS
=========================================================================================
COST ITEM DESCRIPTION
-------------------------------------------------
-------------------------------------------------
OPERATION AND ~AINTENANCE
Cover Regrading/Reworking
Security System Maintenance
Leachate Collection & Leak Detection Main
Leachate Treatment Plant 0 & M
Maintain Runon/Runoff Control Systems
INSPECTIONS AND I4ONITORING
. Site Inspections
Groundwater ~onitoring
Leachate and Leak Monitoring
Security Patrols
SUBTOTAL LONG-TER~ ANNUAL 0 & M
Acininistrative Costs
Contingency Costs
Insurance and Taxes
TOTAL ANNUAL 0 & M COST FOR ONSITE DISPOSAL FACILITY
FREQUENCY
---------
---------
Annually
Semi amua II y
Periodic
Periodic
Semi amua II y
Monthly
Semi annua II y
Periodic
Daily
10 percent
30 percent
5 percent
YEARLY
COST
--------
--------
$18,000
51,800
517,700
59,000
52,700
518,000
$23,600
59,600
516,800
--..-------------
5117,200
511,700
535,200
$5,900
-...--------------
552,800
----------------
----------------
5170,000
-------
9127/88
Table A-12
ALTERNATIVE 6: CENTRALIZEO' LAND DISPOSAL OF EASTERN MISSOURI SOILS AT TIMES BEACH
NO. OF SAMPLINGI AIR
SOIL EXCAVATION DISPOSAL TRANSPORT CLEANUP ANALYTICAL MONITORING TOTAL
VOLUME, COST COST HAUL COST SECTIONS COST COST SITE
(a) (b) (c) MILES (d) (e) (f) (g) COSTS
:~-----------------------I-'----- 1-------,---, 1------------ 1----- 1-----------1-------- 1-----------1------'----- 1---,--------- I
1 I' I I 1 1 1 I . 1 1
: RESIDENTIAL I I 1 I 1 1 1 1 1 1
-.-- -- -- - -- - 1 1 I 1 1 I I 1 1 1
'-Stout Area 11,900 1 '0 \ S282,728 I 19 I '72,200 1 18 I S42,386 I '10,127 I S407,000 I
! Romaine Creek I 4,300 I SO 1 S639,858 I 19 1 '343,140 I 36 1 $84, m 1 S22,919 I. S1,091,OOO I
o Lacy Manor 1 600 1 S252,000 I S89,282 1 26 I S65,520 1 6 I S14,305 I S3,198 1 S424,OOO 1
: Bliss Ellisville '7,000 I S2,940,000 1 S1,041,628 1 10 1 S294,000 I 71 I S166,896' S37,310 1 S4,480,000 I
! COIIII1. Christian Church I 550 1 S231,000 1 S81,842 I 9 I S20,790 1 6 I S13,113 I S2,932 I S350,000 I
I Manchester Meth. Church I 300 I S126,000 I S44,641 I 9 I S11,340 I 3 I S7,153 I S1,599 I '191,000 I
i Eureka-East North Street I 750 I S315,000 1 S111,603 1 4 1 S12;600 I 8 I S17,882 I S3,998 I S461,000 I
: Baxter Garden Center 11,500 I S630,000 I S223,206 I 15 1 S94,500 1 15 I S35,764 I S7,995 I S991,000 I
1-------1 ------.- I ---.---- I I ----.--- 1--'-----1-------'---1-----'------1-------'-----1
subtotal /16,900 I S4 ,494 ,000 1 S2, 514,789 1 I S914, 090 I 171 I S402,936 I S90, 077 I S8,416,000 I
I I I I I I I I 1 I
I 1 I 1 1 I I I I I
1.1 1 I 1 I 1 I I I
ii' I 1 I I 1 '1 I 1
I RESIOENTIAL/CC»4MERCIAL I I I I I I. I I I 1
i ..----.-----..-....--- I I I I I I I I I I
, Highway 141 Access Road" I I' 1 I . I I 1 1
I ~sidential I 520 I S218,400' S77,378 1 13 I '28,392 I 5 I S12,398 1 S2,m I S339,000 I
I :rmercia! I 100 I S42,000 I S14,880 1 ;3 I S5,460 1 1 1 $2,384 I S533 I S65,OqO I
o Eas~ ,exas Motor Freight" I' 0' 1 1 I I I I
residential I 700 I $294,000 I $10~, 163 I 26 I S76,440 I 7 I S16,690 I $3,731 \ S495,000 I
conmercial I 300.1 $126,000 I $44,641 I 26 I $32,760 I 3 I S7,153' S1,599 I S212,000 I
1-------1 -------- 1 .----.-- 1 I -------- ,-.------1-'---------1------------1---'---'----'1
subtota\ 11,6201 $680,400 I $241,063 I 1 S143,052 1 161 S38,625 I S8,635 1 S1,11~,000 I
I I I 1 1 1 I' 1 I I
I I I I I \ I 1 I I
I 1 1 I. I 1 , I I I
NON-RESIDENTIAL I I I I 1 I I 1 I I
---.....---.... I I 1 1 I I I I , 1
Bull Moose Tube I 300 I $126,000 I S44,641 I 44 1 '55,440 I 3 I S7,153 I S1,599 I S235,000 1
Hamill Transfer 1 1,800 I S756,000 I S267,847 I 22 I S166,320 I 18.1 S42,916 I S9,594 I S1,243,000 I
Jones Truck Lines I 1,000 I S420,000" S148,804 1 27 I S113,400 I 10 I S23,842 I '5,330 I S711,000 1
Overnite Transport 1--' I 1 1 28 1 1,,- I. -.. I ..- I ~.. I
Southern Cross Lurber I 1,300 1 S546,000 1 S193,445 1 25 1 S136,500 I 13 I S30,995 I S6,929 I S914,000 I
Times Beach (h) /13,600 I S5, 712, 000 I $7,804,000 I . 0 1 1 138 I S324,256 I S145, 112 I S13, 985,000 1
Ark.ansas 'Best Freight I --- I ! ! 29 1 1,,- I ..- I --- I --- \
Bonifield Brothers Truckl 2,100 I S882,000 I S312,489 I 22 I S194,040 I 21 I '50,069 I S11,193 I S1,450,000 I
1--'----1 ..-.---- 1 -..-----, I -------- j----.---I-"---.-'--I------"----j-------------I
subtotal 120,100 I S8,442,000 I $8,771,226 1 I 1665,700 I 204' S479,231 1 S179,757 I S18,538,000 I
I 1 I I 1 I I 1 I 1
.---"'--'-.-'''--.---.--1-------1-'----------1---''-------1-"--1-----------1"-"--'1-'-'-----.-1'.-.'--'----\-'--------..-\
SITE NAME
-------
Table A-12 (cont.)
.'-----'--'---""--""'1----'-'1--'---------1-"----------1-'--'1----'--'--"'--'----1---""-'--1----"'-'"-1"-'."-'-"-1
I I I I I I I I I I
1 I I I I I I I I I
I I i I I I I I I I
11,6001 $672,0001 $238,0871131 I SBBO,320 1 161 $38,1481 $8,5281 $1,837,000 I
12,780 1 $1,167,600 1 $413,675 1 15 I $175,140 I 281 $66,282 I $14,8171 $1,838,000 I
I 2,550 I $1,071,000 I $379,450 I 4 I $42,840 I 26 I $60,798 I $13,592 I $1,568,000 I
13,300 I $1,386,000 I $491,053 I 61 I $845,460 I 33 I $78,680 I $17,5891 $2,819,000 I
1 7,8GO I $3,276,000 I $1,160,672 I 68 1$2,227,680 I 79 I $185,970 I $83,226 1 $6,934,000 1
I 750 I $315,000 1 $111,603 I 191 S59,850 I 8 I S17,8821 S3,998 I S508,OOO I
1"'----1 -------- I ------.- I I -------- 1'----'--1---"---'--1--""'---"1--'''--''''--1
subtotal 118,780 I S7,887,600 I S2,794,540 I 1$4,231,290 I 190 I $447,759 I S141, 749 I $15,50:5,000 I
I I I I I I I I I I
I 1 I 1 I 1 I I I I
I I 1 I I I 1 I 1 I
I I I I 1 I I 1 I 1
I I I I I I I I I I
I I I I. I I I I 1 I
Castlewood 113,000 I (included I $1,934,453 I 14 I $364,000 I --- I I eo. I $2,298,000 I
Minker, Minker Neighborsl 4,400 1 in past 1 $654,738 I 19 I ~167,200 1 1 1 1 $822,000 I
Cashel Residence 11,000 I costs) 1 $148,804 1 19 1 $38,000 I --- I 1 -.. 1 $187,000 I
Sullins Residence I 400 I I $59,522 I 19 I $15,200 I ---I I ... I $75,000 I
Quail Run 116,000 1 I $2,380,865 I 15 I $480,000 I eo. I 1 ... I $2,861,000 I
1----,,,1 -------- I --------., I --....., 1-----"'1 1-'----'-'-"1--"."'-"--1
subtotal 134,800 I I $5,178,382 I 1$1,064,400 I -u 0' I --- I $6,243,000 1
I I I 1 I I I 1 I I
I I I I I I I I I I
1 ======= I =~======== I ="'======== I. 1 ========== 1 I I I I
I I I I I . 1 I I I I I
TOTAL 192,200 1$21,504,000 1$19,500,000 I 1$7,019,000 I 5811$1,369,000 I $420,000 I $49,812,000 I
I 1 I I I I I I '1 I
-----..-...-------...---.--...-..--------.--------...----.-..------._~.._---------------..._-------_.._..._----.-----...----. I
(a) Revised estimates reflect volume adjustments if contaminated areas which were not originally sprayed with
contaminated waste oil (areas contaminated due to surface migration) require excavation to an average depth
of 6 inches to achieve cleanup criteria. Sprayed areas are excavated to an average depth of one foot.
. .
Horse arenas excavated to an average depth of two feet, horse arena areas OUtside arena excavated to 1 foot,
Shenandoah slough (100 x 100 ft) to 4 feet. 0
(b) Based on Missouri dioxin contract cos $420.00 per cubic yard.
Romaine Creek and Stout excavation costs from Operable Unit Feasibility Studies.
(c) Offsite disposal cost $149 per cubic yard, onsite disp. cost S574 per cubic yard.
(d) Transport cost assumed per cubic yard-mile is $2.10 per cubic yard'mile, except as noted.
(e) Based on average 4,000 square foot sections,except Stout (known) anQ Romaine Creek (3 10-foot wide sections
along creek), plus 50% additional to verify perimeter clean.
(f) Costs repre$ent actual sampling and analytical costs during eastern Missouri removal actions, assuming
8 total 50-aliquot samples per cleanup section at $294 per sample cOllection/analysis.
(9) Air monitoring costs assume $320 per sample,S monitors per site, 1 sample per 3 days per monitor, 100 cubic
yards per day excavated. 10 monitors assumed for Times Beach and Piazza Road.
(h) Excavation cost includes onsite land disposal of structures and debris ($6,836,000) from Times Beach FS.
(i) Transport costs from Times Beach FS. Soil volumes actual for all except Castlewood (estimated).
HORSE ARENAS SITES
.....------------.
Timberline Stables
Bubbling Springs Arena
Saddle and Spur Arena
Shenandoah Stables
Piazza Road
Bliss Frontenac
REMOVAL SITES (i)
-------------
-------
-
RESPONSIVENESS SUMMARY
RECORD OF DECISION
FOR
FINAL MANAGEMENT OF
DIOXIN-CONTAMINATED SOIL AND
FINAL DISPOSITION OF STRUCTURES AND DEBRIS AT
TIMES BEACH, MISSOURI
and the.
MINKER/STOUT/ROMAINE CREE¥ SITE, MISSOURI
Prepared by
u.s. ENVIRONMENTAL PROTECTION AGENCY
September 28, 1988
-------
RESPONSIVENESS SUHHARY
Record
Pinal Management of
Pinal Disposition
" Times
of Decision tor
Dioxin-contaminated Soil and
ot Structures and Debris at
Beach, Missouri
and the
Minker/stout/Romaine Creek Site, Missouri
This Responsiveness Summary presents responses of the".
Environmental Protection Agency (EPA) to public comments received
regarding remedial actions for dioxin-contaminated soil at Times
Beach and the Minker/Stout/Romaine Creek site (M/S/RC), and final
disposition of uncontaminated" structures and debris at Times
Beach. This document addresses all comments received by the
Agency during three public comment periods conducted as part of
the remedy selection process. Several additional comments were
received by the Agency following the close of the most recent
public comment period. All such comments received prior to
publication of this responsiveness summary have also been
addressed.
INTRODUCTION
On February 19, 1988, EPA announced its proposed plan for the
cleanup of Times Beach and the Minker/Stout/Romaine Creek site.
Under the plan, structures and debris remaining in Times Beach
following the permanent relocation would be demolished and
disposed of onsite. Dioxin-contaminated soils at Times Beach
exceeding a level of concern for protection of public health and
the environment would be excavated and treated by thermal
destruction at a temporary unit located onsite. Dioxin-
contaminated soils from the nearby Minker/Stout/Romaine Creek
site would also be transported to Times Beach for thermal
destruction. The proposed remedy would establish management
capacity for a finite number of dioxin sites located in eastern
Missouri which are listed in the Proposed Plan.
A primary feature of the proposed remedy is the cleanup of
structures and debris at Times Beach. This material consists of
440 structures, 77 mobile homes, 60 outbuildings, and
approximately 7,000 additional cubic yards of general debris.
The proposed plan includes the demolition of all structures and
onsite land disposal of the general and demolition debris in a
solid waste disposal facility constructed onsite in accordance
with state regulations. Disposal of structures and debris which
are not located in dioxin-contaminated portions of Times Beach
could begin prior to cleanup of contaminated soils. These
uncontaminated areas are generally located along Interstate 44 in
highly visible areas. The demolition and removal of structures
-------
2
within the former city limits of Times Beach, south of Interstate
44, and those south of Blakey and Lewis Roads will be given
priority. It is estimated that this work can begin within one
year of remedy selection, and completed within an additional
year. The appearance of Times Beach from Interstate 44 would
therefore be substantially improved in the initial phase of the
project.
Demolition and disposal of structures and debris located in
contaminated portions of Times Beach would be performed following
cleanup of contaminated soils. This is aue to the high costs
associated with construction activities when protective clothing
is required for site workers. Cleanups conducted under the
funding and a~thority of the Comprehensive.Environmental .
Response, Compensation, and Liability Act, as amended, (CERCLA)
must be cost-effective. It is therefore necessary to perform the
soil cleanup prior to initiating demolition and disposal of
structures and debris in some portions of Times Beach. These
contaminated areas are, however, less visible from Interstate 44
than those areas where cleanup of structures and debris can be
perfcrmed early in the project.
The proposed cleanup of Times Beach soils is in accordance
with the recommendations of state and Federal health agencies.
EPA has been working with these health agencies' since 1982 to
determin~ an appropriate cleanup level for soils at Times Beach.
In 1984, the Centers for Disease Control (CDC) published a health
assessment which has formed the basis for the cleanup levels
established for dioxin sites in Missouri, including Times Beach.
The CDC, through the Agency for Toxic Substances and Disease
Registry, has advised that soils exceeding 1 part per billion
(ppb) at the surface, or exceeding 10 ppb at one foot depth, are
of concern for protection of human health in residential
settings. Higher cleanup levels would be acceptable in certain
other settings. CDC has recommended that in certain industrial
or commercial settings, a cleanup level of 20 ppb would provide
protection of public health.
A cleanup level of 20 ppb has been established for Times
Beach by EPA on the basis of recommendations from Federal and
state health agencies. This cleanup level is appropriate for the
Times Beach site and consistent with future land uses that
include park areas or green space. Future land use at Times
Beach is controlled through the existing contract for the
permanent relocation and also through requirements of the
Missouri State Hazardous Waste Management Law. These controls
will assure that the proposed cleanup of Times Beach continues to
surpass all criteria for protection of human health and the
environment. Local zoning ordinances may be established to
further ensure that land use remains compatible with the cleanup
and local interests.
-------
3
The proposed remedy involves temporarily siting a thermal
treatment unit at Times Beach for treatment of onsite soils and
other specifically designated materials. Soils at Times Beach
exceeding 20 ppb would be ex~avated and transported to the onsite
the~al treatment unit. The specific location and landscaping of
the thermal treatment unit will be presented to the City of
Eureka for review prior to final design. The City may comment on
the proposed location, and the views and requests of the City
will be accorded consideration. It is EPA's intent to locate the
thermal treatment unit in the most remote area practicable and
minimize visibility from Interstate 44 and the neighboring
residences. EPA will also assure the availability of water at
Times Beach during all phases of the project, as requested by the
local fire protection district..
The thermal treatment unit would be subject to a RCRA permit
issued by the state of Missouri. The RCRA permitting process is,
by statute and regulation, subject to public participation
requirements. The local community will therefore have an
opportunity to provide input during the permitting process.
It is EPA's intent that a permit be sought only for the thermal
treatment of material from Times Beach and the other dioxin sites
listed in Table 1 of the Proposed Plan. Times Beach would not be
available to accept out-of-state wastes. It is EPA's intent to
operate the thermal treatment unit only as long as is necessary
to treat the materials specified in the Proposed Plan and Record
of Decision. It is estimated that the project could be
completed within six years of issuance of a RCRA permi~ for the
thermal .treatment unit. .
The proposed remedy would be implemented under stringent
safety requirements. The primary consideration for the cleanup
is short- and long-term protection of human health and the
environment. The state-issued permit represents one means of
limiting the project duration and specified sources of material
to be treated. The permit would also assure that the dioxin
contamination is completely and safely destroyed.
Safety of the thermal treatment process is assured by
provisions of the state-issued permit, and verified by continuous
monitoring which will be performed throughout the project. The
operating parameters of the thermal treatment unit and emission
controls are continuously monitored to assure that conditions can
not develop which would result in a release of contaminants to
the environment. The unit would be equipped with safety features
to initiate automatic shut-down if operating conditions exceed
the acceptable range. Negative pressure within the unit would
assure that no release of contaminants could occur. In addition,
24-hour ambient air monitoring would be performed at multiple
locations both onsite and offsite to verify that no release of
contamination occurs. Local officials may conduct independent
monitoring of the thermal treatment unit at their election at
reasonable times.
-------
4
Thermal treatment offers many advantages relative to other
remedial alternatives. The process is odorless and there are no
discharges , of any type into the Keramec River or harmful air
emissions. The residue resulting from the thermal treatment of
soil is a non-hazardous solid waste. Thermal treatment
represents a permanent remedy for dioxin-contaminated soils -and
allows future beneficiai use of the site.
The proposed remedy includes the transportation of dioxin-
contaminated soils from the Kinker/Stout/Romaine Creek site to
Times Beach for thermal treatment. In addition, a number of
specific sites are identified which represent potential sources
of dioxin-contaminated soils which may be transpo~ted to Times
Beach for ,thermal-treatment, depending on remedies selected ,for-
these sites in the future. Safety during the transportation of
offsite material to Times Beach is another primary concern.
Transport of soil would only be conducted by fully licensed
companies with experience in the transportation of hazardous
materials. Covered trucks with sealed beds woul~ be used to
control the potential for release of contaminated material. A
transportation study would be performed prior to route selection.
Non-peak hours and non-residential haul routes would be used to
the extent possible. The locations of schools, hospitals, and
other public facilities would be considered in the selection of
transportation routes. Plans outlining transportation routes and
scheduling will be submitted' to local authorities for review and
comment. Development of the final t~ansportation plan will be
- coordinated with ~ocal authorities. ' ,
A safety contingency plan would be developed to provide
emergency response in the event of 'any transport accident. Radio
communication would provide immediate alert if an accident
occurred. Response vehicles would be available for emergency
cleanup and transportation of contaminated soil. The likelihood
of an accident resulting in spillage of contaminated soil is
small due to the safety precautions employed and cautious
procedures which will be used during transportation.
Following completion of the proposed remedy at Times Beach,
beneficial use of the land will be possible. The cleanup will
allow use of the land as a green space, park areas with
recreational use, and potential commercial development. Access
to Times Beach will not be restricted. The restoration of Times
Beach will result in positive impacts to the local community.
PUBLIC PARTICIPATION
In July, 1986, the Agency released the Feasibility StudY of
Final Remedial Actions for the Kinker/Stout/Romaine Creek site.
This study evaluated remedial alternatives for the dioxin-
contaminated soil being temporarily stored at the site, located
-------
5
approximately six miles south of Times Beach. One option
evaluated consisted of offsite thermal treatment at a nearby
centralized facility within 50 miles of the Minker/Stout/Romaine
Creek site. A public comment period was held from August 8, 1986
through September 5, 1986, for the Feasibility StudY of Final
Remedial Actions for the Minker/Stout/Romaine Creek site. A
public meeting was held on August 25, 1~86, to discuss the
alternatives evaluated in the study and the Agency's proposed
remedy.
The Times Beach Feasibilitv StudY was released for public
comment from December 29, 1986, through March 27, 1987. A public
meeting was held on February 12, 1987, to discuss alternatives
. evaluated in the study and to present the Agency's proposed
remedy. A tota.l of. .109 written responses were received . during
the public comment period on the Times Beach Feasibility Study.
Many of these responses consisted of form letters from the local
community. .
The primary concern expressed during the February 12, 1987,
public meeting was the potential permanence of the proposed
temporary thermal treatment unit at Times Beach. The Agency is
sensitive to the concerns of the surrounding communities. A
thermal treatment facility sited at Times Beach will only be used
to treat dioxin contaminated soils orig~nating from Times Beach
.and .the other potenti~l sites. listed in" Table. The ReCord"
of Dec{sion also includes restrictions on the length of time that
the unit may operate. .
A Proposed Plan for Final Manaqement of Dioxin-contaminated
Soil and Final Disposition of structures and Debris at Times
Beach. Missouri and the Minker/Stout/Romaine Creek site (Proposed
Plan) was released by the Agency for public comment on February
19, 1988. A public meeting to discuss the Proposed Plan and the
Agency's preferred alternative. The public comment period on the
Proposed Plan was concluded March 18, 1988.
This responsiveness summary is organized into three
sections. The first section addresses comments received during
the public comment period for the Proposed Plan. The latter two
sections address comments received regarding the Times Beach
Feasibility StudY and the Feasibilitv Study of Final Remedial
Actions for the Minker/Stout/Romaine Creek Site. Attached to this
responsiveness summary are two memoranda for record and one
letter which were prepared by the U.S. Army Corps of Engineers in
response to technical questions received regarding construction
of levees at Times Beach and the associated impact on flood
heights.
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6
This Responsiveness Summary represents a component of the
Record of Decision (ROD) package, which also includes the ROD
declaration, ROD summary, and index to the administrative record.
Formal selection of the remedy to be implemented for Times Beach
and the MinkerjStoutjRomaine Creek site occurs by signature of
the ROD declaration by the Assistant Administrator for the EPA
Office of Solid Waste and Emergency Response.
Following ROD
initiated. During
be followed during
developed.
Following completion of the pre-design phase, the design of
the remedy will be initiated. During.the design phase, the' bid
specifications which will be advertised for proposals will be
developed. This design will be based upon the detailed
implementation plans developed during the pre-design phase. Once
design has been completed, a request for proposals (RFP) will be
advertised for implementation of the project described by the bid
specifications. Implementation of the remedy will commence upon
award of the construction contract(s) to the successful
bidder(s).
signature, a pre-design phase will be
this phase, specific details and procedures to
implementation of the remedy will be
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SECTION .1.
PROPOSED PLAN FOR FINAL MANAGEMENT OP DIOXIN-CONTAMINATED
MATERIALS AND PINAL DISPOSITION OP STRUCTURES AND DEBRIS,
. TIMES BEACH, MISSOURI AND THE MINKER/STOUT/ROMAINE CREEK SITE I
MISSOURI
INTRODUCTION
In February, 1988 the u.s. Environmental Protection Agency
released a Public Comment Draft Proposed Plan for Final
Manaqement of Dioxin-Contaminated Soil and Final Disposition of
structures and Debris at Times Beach. Missouri and the
Minker/Stout/Romaine Creek site. Missouri. A public comment
period for the Proposed Plan was held from February 19.to
March 18, 1988 and a public hearing was held on March 10. .
This responsiveness summary summarizes the public comments made
to the Proposed Plan. These comments include those statements
made at a public hearing held in Eureka, Missouri on March 10,
1988, as well as written comments received by EPA prior to the
clos~ of the public comment period on March 18. EPA responses to
the statements received by the public are included in this
responsiveness summary.
The responsiveness summary for the Proposed Plan is organized in
the following fashion: first, statements made at the publrc
hearing are summarized and EPA responses to the statements are
presented. Then, written comments from the public, PRPs, and
other parties are provided with appropriate EPA response.
COMMENTS RECEIVED AT THE PUBLIC HEARING
In this section, the public comments received by EPA at the
public hearing on. March 10 are summarized. EPA responses to the
comments are provided.
Several commentors expressed concern that the
incineration facility at Times Beach would be used
to treat hazardous wastes other than those
identified in the Proposed Plan and that material
would be brought to the site from out ot the state.
As stated in the Proposed Plan and Record of Decision, EPA does
not intend to incinerate any material at Times Beach other than
that described in the Proposed Plan. The centralized thermal
treatment facility would be constructed to provide final
remediation for the dioxin sites in eastern Missouri identified
in the Proposed Plan and Record of Decision. Material from
outside of the state will not be taken to the site for treatment
or other management. The state of Missouri will control the
material which is transported to Times Beach for treatment, since
the State-issued permit will limit the sources and amount of
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material which the unit can treat. The state
control as site owner, since the title to all
Beach will be conveyed to the state following
permanent relocation.
Only dioxin-contaminated material from the specified sites will
be treated at the facility. A limited amount of soil located
onsite at the forme~ city park area may be treated at the onsite
facility# if it is determined in the future that thermal
treatment of this material meets CERCLA remedy selection
criteria. This material would be treated at Times Beach only if
allowed by the RCRA permit issued for the unit. Dioxin-
contaminated soils at the Ellisville site, if treated at Times
Beach, may be contaminated with other non-dioxin constituents.
This material will be treated at Times Beach only if allowed by
the RCRA permit issued by the state for the unit.
will also gain
properties in Times
completion of the
The length of time that the facility would be left in place at
the site and the sources of material to be taken there would be
controlled through a permit issued by the state. The maximum
duration for a RCRA permit is limited by Federal regulat~ons to
ten years (40 CFR 270.50), although it is estimated that the
project can be completed within 6 years of issuance of the
permit. A state permit will be sought to operate the unit for a
period not to .exceed six years. Public participation would' be an
integral part of the process of securing this permit.
EPA was. asked if it would quarantee that an
incineration facility at Times Beach would not
become a permanent facility and that incineration
equipment would be removed at the completion of the
remedial activities. .EPA was further asked if they
could quarantee the date that the incinerator would
. be constructed, what the remedial activities would
cost, and what would be done at the site. EPA was
asked if the safety of the operation could be
quaranteed.
The EPA will guarantee that the thermal treatment unit to be
located at Times Beach will be temporary and only dioxin-
contaminated soils from those potential sites identified in the
Proposed Plan and Record of Decision will be considered for
treatment at Times Beach.
Following the selection of a remedy, efforts will be directed
toward defining aspects of the specific remedy to be used. These
efforts will include closer engineering evaluation of" issues
relevant to the remedial action. Following this detailed
evaluation, the remedial action will be designed. Attempts will
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be made throu,ghout this process to better define costs, the
project schedule, and safety and other features of the remedial
action. The public will be invited to participate throughout the
period of development.
The thermal treatment unit will be operated under stringent
operating condi~ions specified by the state permit. The.
trial burn will verify that operation of the thermal
treatment unit under these conditions results in the safe
destruction of dioxin. These.operating conditions combined with
the redundant safety features designed into the unit will assure
the continued safety of the public and site workers during
implementation.
.
Several commentors expressed concern ab~ut the
traffic problems and risks from traffic or railway
accidents that might be posed by the transportation
of dioxin-contaminated material to Times Beach from
other areas.
EPA shares these concerns. The use of a railroad for
transporting the material is not planned. Transportation
considerations are limited to movement by road.
It is EPA's intent to develop the plan for the remedial action to
minimize the likelihood of accidents or spills. Licensed waste
haulers with experience in transporting hazardous materials would
be used. Other measures that are being considered to p~event
accidents and spills include the use of air-tight truck beds with
gasketted roll-off boxes, transport only during non-peak hours,
and the use of non-residential roads to the greatest extent
possible. The locations of schools, hospitals, and other public
facilities would be. considered in designating transport routes.
Radio communication and escort vehicles will be considered as
well. A traffic study will be performed early in the planning for
the remedial action. Local coordination will be a key factor in
the development of a transportation plan. The local community
will have an opportunity to provide comments during the
development of the transportation plan. The comments and
concerns of the local community will be considered in the final
plan. contingency measures will be developed as well to provide
immediate response in the unlikely event of an accident or spill.
EPA was asked it clean-up procedures
developed to be used it there was an
spill while .dioxin-contaminated soil
transported to Times Beach.
As noted previously, detailed safety plans will be developed
during the next phase of the project. The plans will include
provisions for immediate alert if a spill occurs and cleanup of
spilled material using vacuum equipment or other equipment as
appropriate, with containerization and transport. These measures
had been
accident or a
was being
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will ensure that no exposure exceeding a level of concern will
occur. All material being transported will be solid. No liquid
waste will be transported to Times Beach, which will
substantially reduce the potential for migration in the event of
an accident.
A commentor asked if EPA had determined the final
classification of the ash from the incinerator,
where the ash would be stored, and how the ash
would be treat~u. E2A was also asked if the treated
materials coming from the incinerator would be
safe.
.
During the incinerator trials at Denney Farm, the destruction of
dioxin in soil in the incinerator exceeded 99.9999 percent. In
fact, no traces of"dioxin"were detected in any ~missions from the
incinerator during the project, including the ash. Similar
destruction is expected for soil treated at Times Beach.
Based on the trial work conducted at Denney Farm, EPA expects
that the ash from an incinerator at Times Beach would be
nonhazardous and can be delisted. The delisted ash would be
considered a non-hazardous solid waste. The ash will tested and
verified to be non-hazardous prior to disposal. As noted in the
Proposed Plan, the ash will be disposed of onsite in a State-
approved solid waste landfill. "
EPA was asked if the
evacuation plan that
occurred at the site
was operational.
Agency had developed an
would be used if flooding
while the incinerator facility
Flood control and contingency measures will be an important part
of the detailed planning for the project. Since the detailed
planning for the remedial action has not been performed, these
plans have not been developed. The thermal treatment unit will be
protected to withstand a lOO-year flood. There should be no need"
to evacuate the equipment. In addition, the Corps of Engineers
has the HEC-2 computerized hydraulic model calibrated for the
Meramec River. Flooding on the Meramec River can be predicted
allowing for the lead-time necessary to evacuate non-protected
equipment and personnel. contingency plans will be developed to
control the release of any hazardous substances in the event of
flood exceeding the lOO-year flood stage.
EPA was asked why the estimates of dioxin-
contaminated material to be remediated had changed
over the years.
Over the years removal actions have been conducted at several
sites and a number of sampling events have been performed. These
actions have provided greater refinement of the estimate of the
soil volumes that are expected to be remediated during the
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remedial actions. In addition, extensive soil sampling has
recently been completed at Times Beach which has confirmed the
lateral extent of contamination throughout the site. EPA is
confident that the present estimates are relatively precise,
although it is likely that the final volumes actually remediated
will differ slightly from the present estimates.
SPA was asked if the air monitorinq and shutdown
procedures that would be used for the incinerator
had been developed. In particular, a commentor
expressed concern that there may be no devices for
continuously monitorinq air emissions from the
incinerator.
A trial burn will be conducted to establish the conditions under
which the thermal treatment unit must be operated to achieve
destruction of the dioxin contamination. During the trial burn,
dioxin-contaminated material will be thermally treated in
combination with selected substances which are more difficult to
thermally destruct than dioxin. The ash and emissions from the
stack will be tested for dioxin during this trial burn, and the
destruction efficiency for dioxin and these other substances will
be measured. This trial burn will determine the operating
conditions which result in the safe. destruction of dioxin. The
state-issued permit will require that the thermal treatment unit
must be operated under the conditions which have been determined
to safely destroy dioxin. without harmful emissions.
The development of appropriate ~ir monitoring and shutdown
procedures will be an important part of the detailed planning
effort. Contemporaneous dioxin levels can not be monitored
continuously at the stack. However, the stack emissions will be
continuously monitored for other parameters which indicate the
efficiency of the treatment and destruction process. In
addition, the operating conditions of the thermal treatment
process will be continuously monitored to assure that the unit is
operated under the conditions which were determined to be safe
during the trial burn. Operation of the thermal treatment unit
under these conditions assures that dioxin is complet~ly
destroyed.
SPA wa. asked if ash and pollutants from the
incinerator would be released into the atmosphere.
A thermal treatment unit used to treat dioxin-contaminated soil
will feature very extensive air-pollution control equipment. The
equipment will include a high temperature chamber to ensure that
organic material such as dioxin is destroyed, and extensive
exhaust cleaning equipment. This equipment will remove
particulates and other pollutants from the exhaust of the unit.
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The stack emissions will be monitored continuously, and 24-hour
ambient air monitoring will be performed onsite and offsite to
assure the 'safety of the operation.
Control of emissions f=om the incinerator at Denney Farm and
other dioxin incinerator trials has been successful. It is '
expected to be equally successful for the remediation at Times
Beach.
A commentor asked EPA if the buildings at Times'
Beach could be torn down since the buildings are an
eyesore.
As noted in the Proposed Plan and Record of Decision, it is EPA'.s
intent to remove the buildings at Times Beach and place the
building materials in a solid waste landfill constructed at the
site.
EPA was asked if the Clean Air Act would be met
during incinerator operations and if the
incineration facility could receive a permit.
The thermal treatment unit will be designed to meet all Clean Air
Act requirements. Previous trials have demonstrated that the
provisions of the Clean Air Act can be met. EPA anticipates that
the proposed remedy will meet all statutory and regulatory
provisions under' the Clean Air Act and will be capable of
receiving a permit under this authority.
A commentor asked EPA if the reason that Times'
Beach would be used for the incineration facility
was Government ownership of the Times Beach
property. The commentor suggested that Times Beach
was not a good location and that the incinerator
should be placed somewhere else because of the
flood plain and requirements for clay.
There are a number of reasons that the Times Beach site has been
recommended for the siting of a thermal treatment unit to treat
dioxin-contaminated material. The reasons include: a state
request t~at the site be considered for a centralized thermal
treatment unit, government ownership of the property, the amount
of land that is available at the site which is not available at
any other identified potential site, access to the site from the
highway, the relatively large volume of dioxin-contaminated
material at the site, and the proximity of the site to other
dioxin sites. The siting of such a facility on the flood plain is
not considered to present unusual engineering difficulties since
a ring levee can be constructed to protect the facility. In
addition, onsite soils and terrain are suitable for
implementation of the project. Underlying clay requirements
which preclude construction of a permanent land disposal facility
are not applicable to a temporary thermal treatment facility.
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SPA vas asked if the incinerator vas safer than the
bunker that had been proposed earlier, partic~larly
in liqht of the additional traffic qenerated by
transport of the dioxin-contaminated material to
the Ti.es Beach. incineration facility.
Both the bunker and the thermal treatment unit would be
protective of human health and the environment. Tqe volume of
material that would be transported for either a bunker or
centralized thermal treatment unit would have been similar. For
the bunker however, a large volume of material would have been
transported to the site over a relatively short period of time
'compared to the centralized thermal treatment facility. It is
likely that traffic control would have been much more difficult
for the. bunker. ..
A commentor asked if the contaminated soil at Times
Beach should be covered and further remedial action
delayed until the incineration technology is
proven.
EPA believes that the thermal treatment technology is
sufficiently well developed and that further delay is
. unnecessary. Incinerators have been successfully used to treat
dioxin-contaminated soil at the Denney Farm site and Johnston
Atoll. pilot units were successfully used .at Times Be~c~.
Evidence from the site indicates that migration from
not a significant problem now, and temporary capping
needed while awaiting the start of onsite excavation
treatment activities.
the site is
is not
and thermal
EPA vas asked it state permission and permittinq to
build the incineration facility vould be needed
since the state of Missouri vill own Times Beach at
the completion of the buy-out.
EPA must obtain access from the state for implementation of the
proposed remedy. Since the state requested that the Times Beach
site be considered for the siting of a centralized thermal
treatment facility, state permission is expected. State permits
will be needed to treat material from offsite and to dispose of
the ash from thermal treatment. The performance of the unit is
expected to meet state requirements.
EPA vas asked it the Aqency had determined the
activities that would be allowable at the site
followinq excavation of soil above 20 ppb and
cappinq of soil from 1 to 20 ppb.
Based upon the recommendations of health agencies, certain non-
residential soils, including Times Beach soils, which contain
dioxin levels less than 20 ppb do not represent a concern for
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public health. Since soils exceeding 20 ppb at Times Beach will
be incinerated, and soils containing dioxin at concentrations
from 1 to 20 ppb covered, the remedial actions are considered
relatively conservative for non-residential exposure to the soil.
Although EPA will not determine the final site usage, the Agency
believes that remediation will allow the site to be used as a
park or green ~pace or other similar' usage.
Due to the limited extent of contamination at Times Beach, the
proposed remedy will actually achieve residential cleanup
criteria in the majority of the site. In fact, over 97% of the
site will have a final dioxin 'level of 1 ppb or less, or 10 ppb
or less at depths greater than one foot, which is below a level
of concern for residential use, as recommended by state and
federal health agencies. '
EPA was asked if an 'incineration facility for
dioxin-contaminated material could be built in
another, less prosperous or less populated part of
the state. It was suggested that this might be
beneficial for the less prosperous areas since jobs
would be created in the areas. It was also noted
that several communities in these less prosperous
areas had been trying to get incineration companies
to locate incineratipn plants in their communities. .
'A commentor a190 asked if an area outside of
st. Louis County that had adequate rail
transportation would be a more acceptable location
for an incineration facility.
EPA believes that Times Beach is an appropriate location for the
siting of a centralized thermal treatment facility for reasons
already presented. Constructing such a facility at another area
in the state would significantly increase the distances required
to transport the contaminated material. Some degree of public
opposition from the local community would be expected at any
location proposed for any type of hazardous waste activity. The
communities near an alternate location for thermal treatment
which was suggested during the public meeting have recently
expressed opposition to siting of a centralized unit in their
area.
Several commentors asked if the impact on the local
economy from construction of an incinerator had
been determined. In particular, concern was
expressed about an incineration facility at Times
Beach creating neqative publicity about the area,
depressing the local economy, lowering property
values, and affecting the local resort businesses.
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The Times Beach site is believed to be currently affecting the
local economy. After cleanup, this impact will be reduced. The
operation of the thermal treatment unit will be coordinated with
the local community to minimize the impact to the local economy
during operation. The location of the unit at Times Beach will be
'selected, in coordination with the local community, to minimize
visibility from Interstate 44 and neighboring residences.
BPA vas asked vny several pieces ot property at
Times Beach had not yet been bouqht out and why
people whose property had not been bouqht out could
not qo onto the site to see their property.
Acquisition of all property included in the permanent relocation
has not been completed. The remaining properties will be acquired
through condemnation due to title problems. Condemnation
procedures have caused delays but are expected to be finished
this year.
The state currently controls access to the site. Arrangements
should be made with the state to enter the site with an escort in
accordance with health and safety requirements.
support was expressed tor ,the incineration ot
dioxin-contaminated material at Times Beach.
EPAbelieves that the centralized thermal treatment represents a
permanent remedy offering management capacity for all identified
potential eastern Missouri sites.
SPA was asked it sand, gravel, sewer lines, and
soil could be placed on the site, and the area
turned into a hard-surtace recreational area or
liqht industrial area. '
EPA has considered this as well as other alternatives.. The
remedial alternative suggested by the commentor is an example of
in-place containment alternatives. In-place containment
alternatives do not achieve remedy selection criteria under
CERCLA, as amended, to the same extent as thermal treatment of
contaminated soils. Specifically, in-place containment
alternatives do not permanently destroy the dioxin, are not cost-
effective, and would likely have significant engineering
difficulties in implementation. other in-place containment
alternatives were evaluated in the remedy selection process which
achieve a degree of control equivalent to the alternative
suggested by the commentor at a substantially lower cost.
A commentor suqqested that incineration can be a
sate process and that there would be no emissions
or residue from the incinerator stack.
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EPA agrees with the commentor.
EPA va. asked vhat public participation had been
involved in the selection and construction of the
spur lev.es at Times Beach.
As explained at the public hearing, public participation
requirements were met with the Central storage site Report and
Record of Decision, which included the spur levees. A Flood Plain
Assessment for the project also prepared and announced, also with
public opportunity to respond.
EPA was asked if the people in Penton had been
notified of the public meetinq.
A legal notice announcing the meeting was placed in the' st. Louis
Post Dispatch on February 19. The same paper ran a front page
article February 20 announcing the meeting. Numerous additional
articles also ran in local newspapers. Over 200 fact sheets and
Proposed Plans were distributed to local media and elected
officials in advance of the meeting.
EPA was asked if other non-incineration processes.
would be considered for remediation at the site.
Several commentors suqgested that they had non-
incineration processes that could be used to
remediate Times Beach.
As noted at the public meeting, EPA has closely examined a number
of other remediation processes in the past and knows of no other
technology capable of destroying the dioxin as safely or
completely as thermal treatment. Although EPA will examine other
promising technologies, thermal treatment is considered, to be the
only proven technology available for treatment of dioxin-
contaminated soil in Missouri.
All thermal treatment processes will be considered during design
of the remedial action for the site; performance-based bid
specifications will be developed that will outline the
requirements for the performance of the thermal treatment unit.
These requirements will include destruction of dioxin exceeding
99.9999 percent and delisting of the ash from the process.
EPA wa. asked if a dioxin concentration of 20 ppb
at the soil surface would be acceptable for
children to play on or acceptable for commercial
purposes.
On the basis of recommendations from state and Federal health
agencies, EPA believes that reducing surface concentrations to
less than 20 ppb would be protective for certain non-residential
usages, including recreational or commercial. As an additional
measure of protection, a one-foot vegetated soil cover will be
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placed over areas with residual dioxin concentrations between 1
and 20 ppb. This will provide a barrier and result in dilution
of subsurface soils in the event of soil disturbance. All
remaining surface concentrations at Times Beach following
remediation will be less than 1 ppb.
A commentor asked if there was a potential danger
for. dust and other particulates to be released into
the air during materials handling and preparation
activities. .
Specific measures to control the generation and release of dust
and other particulates will be selected during the detailed
planning for the project. These measures will be selected to
prevent the release of such material, and would include the
application of dust suppressants and air monitoring onsite and
offsite.
A commentor expressed support for EPA's activities
and indicated that EPA had done a fine job
remediating the Quail Run site.
EPA believes that the remedy at Times Beach can be equally
successful, restoring the site to beneficial use.
A commentor asked if there would be periods when
the incinerator would be cleaned and leakage could
occur. .
The thermal treatment unit would periodically be shut down and
collected material removed. This shutdown wo~ld be preceded by a
period when the unit is operated at high temperature with no feed
material. This would be done to destroy. any dioxin in the
incinerator. Leakage would not present a problem during the
cleaning. Material removed from the incinerator during
maintenance would be disposed as a solid waste.
EPA was asked if the incinerator facility would be
as high as a six-story building.
Although certain portions of the facility, such as the exhaust
stack, may be relatively tall, the overall facility would be
approximately 20 feet tall. Since the facility would be
surrounded by a ring levee, it would be difficult to see much of
the facility at a distance.
EPA was asked if the incineration technology was
really developed and if an incinerator to be used
at Times Beach had been constructed.
Thermal Treatment technology is well-developed. The technology is
being used across the world to destroy hazardous as well as other
wastes.
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While many thermal treatment units that have already been
constructed could be used at the Times Beach site, it is not
known if the specific unit that would be used at the site has
been constructed. Performance-based specifications will be
developed during the design. The unit to be used at the site
would have to meet the performance criteria outlined in these
specifications. .
BPA was asked where the coolinq water for an
incinerator would be disposed.
cooling water would pe treated, stored
analyzed, and land applied at the site
meet requirements for discharge of the
meet all state permit requirements for
while the water was
if the water was shown to'
water. The water would
disposal of such water.
EPA was asked why the proposed location for the
incinerator was near a railroad since the
incineration facility was only intended to be a
temporary facility.
The specific location of a thermal treatment unit on the site has
not been determined. This will be an issue for the detailed
design of the facility and will be determined in consideration of
comments and concerns of the local community. The location
mentioned in the Proposed Plan is a possible loqation, and was
mentioned only because the location appears to offer advantages
in terms of visibility from Interstate 44 and the impact on flood
heights. other options will be considered.
A question was asked about how EPA would ensure
that the drinkinq water in the area would be
protected, particularly the water drawn from the
Keramec river.
The actions being proposed by EPA will further ensure that water
is protected since dioxin-contaminated material will be excavated
and the dioxin destroyed. Any process water generated during the
remediation efforts will be treated to meet all permit
requirements prior to discharge of the water on the land. Samples
of the Meramec River water will be taken at the intake to pUblic
water supplies to monitor the quality of the water.
EPA was asked if the public comment period for the
Proposed Plan could be extended.
EPA believes that the period afforded for comment by the public
on the Proposed Plan was adequate. The public comment period
closed March 18, satisfying statutory and regulatory requirements
for public comment. There was a three month comment period for the
Times Beach Feasibilitv StudY, which evaluated similar
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alternatives.
BPA .a. asked what measures would be taken if soil
leaked fro. the trucks transporting the
contaainated soil and local citizens experienced
allergic reactions to the dust.
As noted previously, measures
dust from trucks transporting
expected to be a problem. In
is being proposed.
will be taken to prevent release of
the contaminated soil. This is not
addition, no transport of liquid wastes
BPA .as asked if the decision for the site had
already been made and if the comments made at the
public hearing would actually be considered in
making a decision.. . .
All public comments will be considered when the remedy is
selected. The remedy will be formally selected in the Record of
Decision.
EPA was asked if the soil cover for certain areas
could be washed away and residual dioxin-
contaminated soil exposed.
since soils exceeding a level of concern for protection of human
health are being removed, the continued integrity of the soil.
cover is not critical to maintaining the effectiveness of the
remedy. However, measures are being taken to control. the
potential for erosion. Spur levees currently being constructed
will control the velocity of the flood water and will reduce
erosion potential. The design of the soil cover will further
reduce the potential for exposure of contaminated soil due to
erosion. .
Several alternate solutions were suggested for the
site, including plowing the soil and exposing the
material to the sun, and confining the site with
dikes and capping the material.
A number of remedial options have been considered for the site.
Exposure of contaminated soils in eastern Missouri to sunlight
has not been found to effectively reduce dioxin concentrations to
acceptable levels. For example at the Castlewood site, sampling
of dust samples .collected from the pavement surface detected
dioxin levels of 40 ppb. If sunlight were determined to
effectively destroy dioxin at the soil surface, there would be no
reduction in dioxin concentrations immediately beneath the
surface, which would require that the subsurface soils be
continually brought to the surface, which could be accomplished
by plowing. However, it is likely that the process of plowing
would release contaminated soil particles into the air, thereby
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1-14
increasing exposure potential. Since soil sampling has not
determined that ultraviolet degradation of dioxin effectively
reduces dioxin levels in eastern Missouri soils, this alternative
was eliminated from further consideration.
In-place containment alternatives were evaluated in the Proposed
Plan and Feasibility Study for Times Beach and rejected. In-
place containment a:t~r~atives do not satisfy CERCLA remedy
selection criteria to the same degree as the selected remedy.
In-place containment does not represent a permanent remedy which
utilizes treatment as a principal element to reduce the toxicity,
mobility, or volume of hazardous materials at the site. In-place
containment alternatives are dependent upon ongoing monitoring
and maintenance to assure long-term protection of human health
and the environment. In-place containment is not capable of
ach~eving all identified ARARs, particularly landfill closure and
post-closure requirements under RCRA and siting requirements
under the Missouri Hazardous Waste Management Law.
A commentor asked wby detailed engineering plans
had not been released on how the dioxin-
contaminated material would be incinerated.
As noted previously, specific features of the selected remedial
action 'will be evaluated in greater detail following selection 'of
a remedy. Detailed engineering plans have not been developed thus
far, but will be as part of remedial action design effort.
EPA was asked if it was justifiable to cleanup the
site to anything greater than 1 ppb and if
rationale for the 20 ppb action level described in
the Proposed Plan was available. It vas suggested
that the 20 ppb action level was not satisfactory.
The 20 ppb action level selected for Times Beach is considered by
EPA to be protective of public health and the environment. The 20
ppb action level is based on a 1984 risk assessment performed by
Dr. Renate Kimbrough et al., Center for Environmental Health,
Centers for Disease Control and subsequent correspondence from
federal and state health agencies. Correspondence summarizing
the rationale for 20 ppb were attached to the Proposed Plan.
EPA vas asked if additional contaminated material
would be placed in the city park.
No contaminated material will be placed in the city park.
A commentor asked about the status of the Bubbling
Springs site and why the site had not been
remediated.
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1-15
Residential sites in Missouri have been prioritized for cleanup.
The Bubbling Springs cleanup is under development, but has not
been scheduled yet. The site is one of those noted in the'
Proposed Plan that could potentially be managed using the
centraJized thermal treatment unit that would be constructed at
Times Beach.
SPA vas asked vhy the incinerator for the Times
Beach site, if it vas mobile, could not be taken to
the other sites outlined in the Proposed Plan for
incineration at Times Beach and the incineration
performed at those areas.
There are several important difficulties that preclude taking the
thermal treatment unit to each of the individual sites. First,
there is not enough open acreage available at many of the areas
to site such a unit. Second, the overall cost would be
significantly higher, due in part to costs associated with
mobilization and demobilization, and permitting of the
incinerator. Centralized thermal treatment is considered to be
much more cost-effective than taking a unit to each individual
site. '
EPA vas asked about the status of Technical
Assistance Grants and when the grants would be
available to local communities.
On March 24,'1988, EPA published an i~terim final rule for
providing technical assistance grants of up to $50,000 in the
Federal Register (53 FR 9736). These grants are available to
qualifying citizen's groups for the purpose of obtaining
assistance in interpreting information related to cleanups at
Superfund sites. .EPA anticipates award of these technical
assistance grants to begin in the fall, 1988.
One commentor recommended that the site be left as
it is for the time being since the health effects
ot dioxin to humans are not thought to be
significant.
The no action alternative is not considered by EPA to be
acceptable for the site. The potential for exposure continues to
exist and buildings at the site continue to deteriorate,
resulting in an unacceptable risk to public health and the
environment. A long-term remedy that is compatible with
regulatory requirements and provides protection of human health
and the environment must be selected; no action is not considered
to be a satisfactory selection. '
SPA was questioned about the heights of the spur
levees being constructed at Times Beach and their
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1-16
effects on flood heights.
Minimal impacts on the
levees. This issue was
member of the Corps of
in a letter attached.
flood heights are expected from the spur
addressed in the public meeting by a
Engineers. Further explanation is provided
WRITTEN COMMENTS RECEIVED PROM THE PUBLIC
A number of commentors provided written responses to the Proposed'
Plan. Comments not previously addressed in the public meeting are
discussed below. The comments are organized into several
categories, including general comments, comments on health-
related issues, remediation concerns, thermal treatment concerns,
and legal and procedural issues. '
General Comments
A commentor asked if a solution restricted to Times
Beach could be completed by 1990, if the buildings
a= Times Beach could be removed by the summer or
fall of 1988, and if the site could be
returned to a natural state.
The timing of the cleanup of the structures and debris has been
studied. It is considered cost~effective to clean up the
structures and debris located in contaminated portions of the
site following dioxin 'remediation. Since CERCLA remedial
activities must be cost-effective, remediation of the structures
and debris in contaminated portions of the site must be performed
after dioxin remedial activities are completed. Structures and
debris located in uncontaminated portions of Times Beach adjacent
to Interstate 44 will be cleaned up in the initial phase of the
project, prior to dioxin remediation. It is believed that the
cleanup of soil at Times Beach could be completed within six
years of issuance of a RCRA permit to conduct thermal treatment.
One commentor requested that he be allowed to '
purchase one or more of the buildings at the site.
Salvage of the buildings will be considered during design of the
remedy for the structures and debris. If it is found to be cost-
effective, salvage may be performed after testing has
demonstrated that the buildings are free of contamination.
Several commentors asked if it would be safe to
locate the incinerator at Times Beach, considering
the site's location with respect to the highway,
schools, local communities, and the city of st.
Louis.
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1-17
As discussed previously, EPA believes that the thermal treatment
unit can be operated safely at Times Beach and that transport and
material handling can be conducted in a manner that presents
minimum risk to the public. The overall remedy is considered to
be protective of human health and the environment.
BPA was asked if the down-time encountered with the
BPA mobile incinerator durinq BPA tests in Denney
Para and the lenqth of time that the incinerator
was operated were concerns of BPA. .
The incinerator operated at the Denney Farm site is a research
unit that was not designed specifically for soils. handling.
Recent changes were made to the unit, such as the retrofitting of
the unit with equipment that will increase the operating capacity
and reduce downtime associated with maintenance of the air
pollution e~ipment, that should significantly improve operation
of the incinerator. It is anticipated that downtime for a unit at
Times Beach would not exceed 30 percent of the available time.
A commentor asked if there vas conclusive evidence
reqarding dioxin's risk acceptability. SPA was
asked if the toxicity of dioxin to humans, apart
from c~loracne, has been .demonstrated.
There is disagreement in the scientific community regarding the
'risks due to exposure to dioxin. The position of EPA is to take a
conservative position to ensure that any error made in the
assessment of risk was made on the side of safety. CDC has
recently reaffirmed support of the 1984 health assessment that
established the original action level for exposure to dioxin in a
residential setting. There has been no scientific evidence
presented to date that invalidates the 1984 assumptions or
conclusions.
One commentor suggested that the Times Beach site
should be treated as a residential area when
selectinq a basis for remediation and that the 20
ppb action level is inappropriate for such an area.
EPA believes that residential development of the site in the
future is unlikely due to institutional controls and practical
considerations involving the flood plain. EPA therefore believes
that a non-residential level of concern represents a more
suitable level to target remediation at the site.
SPA was asked if the TCDD at concentrations from 1
to 20 ppb at Times Beach that would be capped would
be excavated and consolidated at one area of the
site prior to capping.
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1-18
The soils containing dioxin at concentrations from 1 to 20 ppb
would be covered. in place.
BPA vas asked if only soils exceedinq 20 ppb which
are brouqht to Times Beach vouldbe thermally
treated. If some material transported to Times'
Beach vere not thermally treated, the commentor
questioned vhere the untreated soil vould be
placed.
All soils brought to Times Beach from off-site would be thermally
treated. Ash from the treatment process would be land disposed
at Times Beach.
A commentor asked if a hazardous waste landfill
constructed at Times Beach for disposal of ash and
untreated soil would violate the Missouri Hazardous
Waste Manaqement Law.
The landfill constructed at Times Beach for disposal of ash would
not be a hazardous waste landfill. The landfill would be designed
and constructed to accept non-hazardous solid waste, in
accordance with state requirements. The ash from the thermal
treatment process will undergo a delis~ing procedure. so that this
material can be' disposed of as non-hazardous solid waste.
Following delisting, the ash would be considered a non-hazardous
solid waste which is suitable for disposal in a solid waste
disposal facility. No' disposal of untreated soil is included in
the proposed remedy.
EPA vas asked if the plan to protect an incinerator
at Times Beach vith spur levees vas vorkable.
The spur levees are presently being constructed to slow the
velocity of flood waters across the site. A thermal treatment
unit would be protected by a ring levee. The Corps of Engineers
has evaluated the construction of such a levee and considers it
to be workable.
A co...ntor asked about the environmental effects
that aiqht occur if a containment structure vas
built at Times Beach to store soil from other
sites, and a flood occurred that damaqed the
structure and caused dioxin-contaminated soil to be
released to the Meramec River.
This risk is discussed in the Times Beach Feasibilitv study and
Proposed Plan.
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1-19
EPA va. asked if there was a threat to the
municipal vater supply from the TCDD-contaminated
soil not. exceeding 20 ppb. that would be capped at
the site. .
On the basis of sampling, Times Beach has been determined to not
represent a significant source of dioxin into the Meramec River.
No dioxin has been de=ected in Meramec River water at waterworks
intakes. The remedy selected for Times Beach will further reduce
the threat of dioxin transport to the Meramec River, since soil
remaining that contains dioxin in excess of 1 ppb would be
capped.
A commentor asked if an in-depth traffic study
would be conducted before a final proposal for site
.remediation would be selected.
A traffic study will be performed during the design phase of the
project.
A commentor asked if there was a federal regulation
. which prohibited the altering of the natural flow
of a waterway if it endangered another person's
property. EPA was further asked if they were
required to build a levee on the other side of the
Meramec River away from Times Beach since levees
were being constructed on the site.
The remedy will have minimal impacts on flood heights, so there
is expected to be no significant impairment of property. The spur
levees were constructed to reduce flooding velocities at the site
if a flood occurred. There is no reason to build similar levees
on the other side of the river since dioxin contamination is not
known to exist there. Such construction would not be justifiable
as a CERCLA expense.
A commentor proposed that the contaminated soil at
Times Beach be left in-place, buildings be removed,
and the aite restored to a natural wetlands area.
The co..entor suggested that there would be nothing
gained from incinerating the soil since the
material did not present a significant risk to
human health and that prolonging the cleanup would
only aggravate the emotional trauma to the
residents in the area.
The health and environmental risks due to dioxin at the site have
been previously discussed. It is EPA's opinion that remedial
actions must be undertaken at the site due to these risks and the
objective of providing a suitable long-term remedy for the site.
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l-2~
Health Issues
A co...ntor sugqested that the Proposed Plan
overstates the threat to human health and the
environment pc sed by the hazardous substances at
Times Beach and that the basis for the 1 ppb action
level developed by CDC for exposure to dioxin-
contaminated soil in a residential setting
substantially overestimated the health risks due to
dioxin exposure. It was further suggested by the
commentor that new information should cause the
risk assessment for Times Beach to be changed.
These comments have been responded to previously. CDC has
recently reaffirmed its support of the 1984 health assessment.
It was suggested that the 20 ppb non-residential
action level considered appropriate for the site
overestimates the potential risk presented by the
contaminated s~il at the site. EPA was further
asked why the proposed Plan was not accompanied by
a quantitative exposure measurement that would
support the 20 ppb action level being considered
for the site. .
The rationale for selection of the 20 ppb action level was given
in documents attached to the Proposed Plan. Those documents
include correspondence from ATSDR that evaluate the 20 ppb action
level and its protectiveness of human health in a non-residential
setting. The 20 ppb action level was established by EPA on the
basis of recommendations from state and Federal health agencies
and exposure data presented in the the feasibility study risk
assessment.
EPA was asked if the classification of Times Beach
as a non-residential site made the risks of human
exposure to contaminants at the site from
ingestion, inhalation, or direct contact
insignificant.
The risks quantified for non-residential use in the feasibility
study were not insignificant. Health agency recommendations for
nonresidential use indicate that concentrations of dioxin in soil
represent a level of concern.
One commentor suggested that EPA's methodology for
assessing cancer risks from TCDD is much more
conservative than those of other regulatory
agencies.
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1-21
EPA believes that its risk assessment procedures are
appropriately conservative.
A CO"8D~or ques~ioned whe~her,new samplinq data,
coabiD84 with existinq access restrictions,
valida~8d the no action alternative with at most a
soil cap, as 'beinq the sates~ and most protective
course ot action tor the site.
New sampling data has confirmed previous data. The evaluation of
remedial alternatives in the feasibility study and Proposed Plan
remain valid as a result of this new data.
BPA WaS asked it it was necessary to place a clean
soil cover over those areas contaminated with soil
below the applicable level ot concern. A commentor
suqqested that remediation ot the areas between 1
and 20 ppb was unnecessary in a non-residential
settinq such as Times Beach.
The soil cover provides protection of the environment and an
additional barrier for protection of human health. The soil cover
woul(~ ~ffectively dilute any contaminated soil brought to the
'surface and would provide stability to prevent erosion and
migration.
One'commentor suqqested that the proposed level ot
concern noted in the Proposed Plan tor airborne
TCDD and clean-up level tor interior surtaces is
inappropriately low.
The level of concern is that which is recommended by federal and
state health agencies. EPA believes the level to be appropriate
and necessary to assure protection of health and the environment.
BPA was asked it the delisted ash trom the
. incinerator, since the material would be
nonhazardous, would best be utilized as backtill
tor excavated areas ot Times Beach. It was
suqqes~ed that this could be done by mixinq the ash
with clean, native soil.
Once delisted, the ash would be considered a solid waste. The
decision to land dispose the material will be made in accordance
with state solid waste disposal requirements. The use of such
material as backfill will be considered if such use is acceptable
to the state.
BPA was asked why the proposed plan does not
contain a quantitication ot the risks ot on-site
incineration.
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1-22
No dioxin was detected in the emissions or ash at the Denney Farm
trial. It is therefore not possible to quantify risks due to
exposure to such material. The safety risks from operation of an
incinerator were evaluated qualitatively in the feasibility study
and the Proposed Plan.
Remediation Issues
A commentor suggested that the Proposed Plan does
not adequately address the in-place containment
alternatives.
EPA believes that the feasibility study and the Proposed Plan
provided adequate evaluation of the in-place containment
alternatives.
One commentor questioned whether it was appropriate
to include other sites for remediation at Times
Beach since remedial investigations, feasibility
studies, and site-specific risk assessments had not
been conducted at those sites.
The decisions made for Times Beach and the Minker/stout/Romaine
Creek sites are based on previous studies. As discussed in the
Proposed Plan, future decisions for other sites will be made
independently on a site-by-site basis. .
A commentor sU9gested that previous actions
by BPA to remove contaminated soil from the
portion of the M/S/RC site were ill-advised
that actions at the stout and Romaine Creek
portions of the site are not justified based
risks associated with the areas.
taken
Minker
and
on the
In making previous decisions regarding these response actions,
EPA has determined that the actions taken at these sites meet
CERCLA and NCP remedy selection criteria.
A comaentor concurred with EPA that the best place
to put a centralized thermal treatment facility was
Time. B.ach.
As discussed previously, EPA believes that the siting of a
centralized thermal treatment unit at Times Beach offers many
important advantages over other areas.
EPA was asked why the incinerator at Times Beach
could not be used to treat dioxin-contaminated soil
from all of the sites in Missouri, rather than only
those noted in the Proposed Plan.
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1-23
Public participation is an important component of the CERCLA
remedy selection process. The local community has expressed
opposition to material being transported to Times Beach for
treatment from other states, or other portions of Missouri. EPA
has considered the position of the local community in proposing
and selecting a remedial alternative.
The sites identified in the Proposed Plan are related to waste
oil spraying conducted by the Bliss Waste oil Company in the
early 1970's. EPA considered public comments on bringing
additional material to Times Beach and concluded that
contaminated materials from other locations not identified in the
Proposed Plan would not be brought to Times Beach for
incineration.
One commentor suggested that there was no rationale
to excavate or incinerate dioxin-contaminated
material from any of the confirmed dioxin sites in
the state.
Future decisions regarding response actions at the other sites
will be made on a site-by-site basis, as noted in the Proposed
Plan.
EPA was asked to explain why the Erxleben site was
not included and the Bristol Steel site was
included with the sites listed in the Proposed Plan.
tor thermal treatment at Times Beach.
Recent comprehensive sampling by EPA at the Erxleben site did not
detect contaminant levels exceeding a level of concern for
protection of public health and the environment. Bristol Steel
has been included due to the reported detection of dioxin in that
property by the current site owner. This dioxin is believed to be
present on the property due to the spraying of waste oil on the
property by the Bliss Waste oil Company in the 1970's.
EPA vas asked what levels of concern would be
achieved following excavation of the soil volumes
tor the sites listed in the Proposed Plan. EPA was
also ..ked whether excavation of the volumes listed
would enable the State to remove each site from the
Missouri dioxin registry.
Future excavation decisions are not being made at this time. The
volumes estimated for these sites assume that the residential
sites are cleaned to 1 ppb surface concentration and 10 ppb below
1 foot depth and that commercial or industrial areas are cleaned
to an action level of 20 ppb. The state is evaluating whether
these sites can be removed from the state registry if these
cleanup levels are achieved.
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1-24
One co..entor suggested that the tables in the
propo.ed Plan listing soil volumes be updated when
ne. information became available and be restricted
to dioxin-contaminated soil volumes only.
The projected soil volumes are continually updated as new data
becomes available. Non-dioxin contamination is excluded from the
list. .
SPA was asked whether it was lawful or appropriate
to use superfund money to remove or destroy
uncontaminated structures and debris at the Times
Beach site.
EPA believes that it is lawful and appropriate to clean up
structures and debris at Times Beach as a completion of the
permanent relocation that was announced in 1983.
SPA was asked if there was sufficient
site to construct a cap for the areas
contamination between 1 and 20 ppb or
borrow would have to be obtained at a
borrow on the
with dioxin
if offsite
premium cost.
Sufficient borrow has been identified onsite or immediately
adjacent to the site by the Corps of Engineers for construction
of the soil cover. Acquisition of high~cost borrow'material will
not be required.
SPA was asked if the construction of a a one-foot
layer of soil over the 1 to 20 ppb soil areas would
create a "rice paddy" effect, with water ponding
between the covered street areas.
Design and construction of
provisions for drainage to
methods of providing a one
evaluated during design.
SPA ... asked if a deep tillage/soil inversion
technique could be used instead of the one-foot
soil cover to achieve remediation in the areas
bet.een 1 and 20 ppb.
the soil cover would include
eliminate the problem. Alternative
foot clean soil layer will be
This particular technique shows merit and will be evaluated
during the design phase for the remedial action.
One commentor expressed concern that clean soil
placed on paved areas would lack stability and
could erode. It was suggested that soil inversion
could be used instead for the paved areas.
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1-25
A soil cover placed over paved areas would be vegetated to
~ini~ize erosion. A soil cover over paved areas would be less
affected by instability and erosion than would a soil cover over
an impermeable membrane (alternative 2) since the pavement is
generally in a deteriorated state and some degree of infiltration
would be possible, and because the pavement width is generally
much narrower than would be the width of a membrane covering
contaminated areas. soil inversion as a potential method of
providing a one-foot clean soil layer will be evaluated during
design.
EPA was asked if a RCRA equivalent cap is
technically proper and economically justified. The'
comment or suggested that such a cap would not be
appropriate for the site considering the nature of
the contamination and that only a vegetative cover
is required.
EPA evaluated construction of a RCRA equivalent cap and is not
proposing that such a cap design be used. A vegetated soil cap is
a component of the proposed remedy.
EPA was asked if long term maintenance or
monitoring was required after the site had been
remediated. The commentor suggested that such
maint&nance or monitoring would not be re~ired..
Federal health agencies have advised EPA that the proposed
cleanup is protective of human health, and that following
completion, no further follow-up testing or monitoring would be
necessary, except in the event of widespread soil disturbance.
Periodic inpections would be required to assure that future land
use remains consistent with the cleanup, and to note any areas of
widespread soil disturbance.
The proposed cleanup would result in soils remaining on site
which could potentially impact the environment through migration
and bioaccumulation, although environmental impairment has not
been observed to date. Periodic surveillance to detect eroding
areas or areas of soil disturbance is required to provide an
additional measure of protection for public health, and to assure
the continued protection of the environment. At their election,
local authorities could arrange for independent monitoring.
Maintenance would consist of performing necessary repairs to
eroding or disturbed areas. As noted in the Proposed Plan, the
continued integrity of the soil cover is not critical to assure
protection of public health, since contaminated soils which
exceed health-based levels will be removed.
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1-26
A co...ntor suqqested that the interior cleanup
level noted in the Proposed Plan vas too low. The
commentor suqqested that the interior cleanup level
of 4 picoqrams per square meter applies to
residences that viII be reinhabited and not to
those that viII be demolished. It was suqqested
that further samplinq of the structures was not
needed. .
Testinq will be required prior to disposal of structures and
debris to confirm that the material is free of contamination. and
can be disposed of as a non-hazardous solid waste.
Decontamination,will be required if dioxin is detected.
EPA was asked it the remediation ot the city park
would be considered as a totally separate endeavor.
It was suqqested by the commentor that the'
remediation should be performed in a manner
consistent with the rest of the site.
As discussed in the Proposed Plan, the contamination in the city
park is independent and unrelated to the dioxin contamination. It
is considered appropriate to evaluate and proceed with
remediation of this area independently. Due to the relative
maqnitude of the dioxin cleanup, the non-dioxin evaluation should
not delay implementation of remedial measures.
Thermal Treatment Issues
A commentor suqqested that the proposed Plan is
weiqhted in tavor of on-site incineration since the
plan considers the treatment of other sites at
Times Beach. The commentor suggested that the
additional volume of material creates a bias
aqainst other alternatives such as on-site
containment or storaqe.
EPA believes that it is appropriate to consider the potential
need for response at other eastern Missouri dioxin sites in the
remedy selection process for Times Beach. The sites listed in
the Proposed Plan are related in the sense that all became
contaminated as a result of the direct or indirect application of
dioxin contaminated waste oil in the early 1970's by the Bliss
Waste oil Company. The remedy selected now for Times Beach will
impact the future availability of management capacity for the
other sites. EPA is seeking a cost-effective, comprehensive
approach for addressing response requirements at each site. It
is therefore appropriate to select a remedy for Times Beach in
consideration of the potential future need for management of the
soils from the other sites.
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1-27
BPA ... asked it a better location tor a thermal
treata.nt unit vould be the area bounded by the
Dogwood, orchid, Grove, and Dahlia streets.
The location of the thermal treatment unit will be determined
during design. As stated previously, the proposed location in the
northwest portion of the site minimizes flood height impact and
visibility. The final location will be determined in coordination
with the local community.
.
BPA .as asked it the incineration schedule
appearing in the Proposed Plan vas realistic,
considering the time required tor" planning, design,
tabrication, site preparation, and other
activities, as well as contingencies tor untoreseen
ditticulties.
EPA believes that the schedule appearing in the Proposed Plan is
reasonable and can be met barring unforeseen delays.
BPA vas asked it delisting criteria comparable to
those prescribed by the 1985 exclusion would be
imposed in the tuture. . "
Ash from the thermal treatment process must be formally delisted
through the same process required in 1985 for delisting of
residue at the "Denney Farm site.
Procedural and Leaal Issues
A commentor suggested that BPA is soliciting public
comments on the proposed Plan vithout having
intormed the public ot EPA's response to public
comments on remedial alternatives described in the
teasibility studies. The commentor turther
suggested that EPA has not explained its rationale
for abandoning alternatives trom the feasibility
studies and selecting new alternatives in the
propo..d Plan.
EPA is not required to publish a responsiveness summary prior to
the release" of the Record of Decision. Treatment and containment
alternatives in the feasibility study that potentially achieved
CERCLA remedy selection criteria were selected and developed
further in the Proposed Plan.
Alternatives which were evaluated in the Proposed Plan were
determined by identifying remedial alternatives evaluated during
the remedial planning process which satisfied CERCLA remedy
selection criteria to the greatest extent, and developing them
further to address the goals of the cleanup.
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1-28
One co..entor suggested that the Proposed Plan
contained two capping alternatives that had not
~een included in the feasi~ility study. The
commentor suggested that CERCLA requires that
states ~e afforded the opportunity to comment on
the planned remedial action descri~ed in the
feasi~ility study.
An opportunity for the state to comment on the two capping
alternatives in the Proposed Plan was provided during the public
comment period.
EPA was asked why it had not explained the> Agency's
plans for remedial action at Times Beach were
changed after the permanent relocation was
performed and a January 1984 ROD signed.
The permanent relocation and 1984 Record of Decision, including
the subsequent cancellation of the Interim storage Facility
project, were described in the feasibility study and Proposed
Plan. Both of these documents were released for public comment.
EPA was asked why a no action alternative was not
included or comprehensively evaluated in the.
Proposed Plan.
The no action alternative was evaluated in the feasibility study
and eliminated> from further consideration by EPA prior to the
Proposed Plan. As discussed previously, EPA does not consider the
no action alternative to present a suitable long-term remedy for
the site.
One commentor suggested that the public comment
period for the Proposed Plan was unreasonably
short. The commentor further suggested that
comments received ~y EPA could only receive a
cursory review and consideration if a ROD is to be
issued by Karch 31, 1988.
The public comment period satisfies the statutory and regulatory
requirements under CERCLA and was adequately long. All comments
received during the comment period are being considered prior to
remedy selection and addressed in the responsiveness summary.
EPA was asked if the Times Beach site should never
have ~een listed on the National Priorities Lis~
(NPL) since the original listing in 1983 was ~ased
on an alleged groundwater threat at the site. The
feasibility study and Proposed Plan both have ruled
out dioxin movement to groundwater as being a
significant threat.
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1-29
The Times Beach site was listed on the NPL as a result of a
ranking using the Hazard Ranking System eRRS). This ranking
remains valid, and inclusion on the NPL is considered
appropriate.
BPA was asked if a delisting petition would be
needed for disposal of incinerator residues from
other Missouri di~xin sites if all of the sites in
Missouri were treated as a single site.
valid
. A single delisting procedure will be required for residue from
treatment of soil from all potential locations identified in the
Proposed Plan. . .
One commentor stated that the dioxin contamination
.at Times Beach presents no significant risk to
human health, and that the proposed incineration
will only generate additional wastes and prolong
the cleanup which will aggravate the emotional
trauma of the residents. The commentor suggested
allowing natural processes to remedy the problem,
leaving the soil in place, removing structures, and
restoring the site to a natural wetlands area. The
commentor .stated that the dioxin contamination will
not migrate from the site, and is not absorbed by
vegetation. The commentor stated that dioxin on
the surface of the soil has been detoxified by
ultraviolet light. A number of studies were cited
which draw varying conclusions on the human health
hazard represented by dioxin.
As stated previously, the cleanup level established for Times
Beach is based upon recommendations from state and federal health
agencies. A risk assessment was performed in 1984 by Kimbrough
et al. which formed the basis for these recommendations. CDC has
recently reaffirmed its support of the assumptions and
conclusions presented in the 1984 study.
Thermal treatment of contaminated soils results in the
destruction of dioxin to undetectable levels. Once delisted,
this material can be disposed of as a non-hazardous solid waste.
On the basis of experience with thermal treatment of soils in
southwest Missouri, EPA believes that delisting of the treatment
residue will be achievable. Thermal treatment therefore converts
a hazardous waste material to a non-hazardous waste material
which represents no significant risk to public health and the
environment.
There will be short-term onsite construction activities
associated with implementation of the remedy. It is estimated
that the project can be completed within six years. It has been
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determined that the proposed remedy will provide greater short-
and long-term protection of public health and the environment by
destroying dioxin contamination in a safe manner than would be
achieved by no action. Allowing the contamination to remain in-
place represents an unacceptable risk to public health and the
environment. The long-term economic welf~re of the community is
also expected to be substantially improved by implementation of
the proposed remedy.
Ultraviolet degradation of dioxin in surficial soils has not been
demonstrated to reduce contaminant levels to the extent necessary
for protection of human health and the environment in a
reasonable time frame. Surface concentrations as high as 1600
parts per billion (ppb) have recently been detected at Times
Beach, which exceeds the highest. levels detected during extensive
sampling conducted from 1982-1984. It is not apparent that
surface dioxin levels are being substantially reduced.
Ultraviolet exposure has also not been effective at degrading
surficial dioxin at the nearby Castlewood site, where levels as
high as 60 ppb have been detected in dust samples collected from
street sweepings. Even if ultraviolet exposure was determined to
be effective at degrading surficial dioxin contamination, dioxin
levels immediately beneath the surface would be unaffected and
would continue to represent an unacceptable risk to public health
and the environment.
Sampling of offsite sediment and biota has not indicated that a
substantial amount of dioxin-contaminated soil is migrating from
Times Beach. Analysis of ground water samples collected directly
onsite has not detected the presence of dioxin. However, it is
conceivable that some degree of contaminant migration is
occurring from Times Beach, particularly during flood events.
The proposed remedy and completion of the spur levee project will
control the potential for offsite migration of dioxin from Times
Beach.
Dioxin uptake in plant life is uncertain. Although dioxin uptake
in vegetation appears to be insignificant, the literature does
contain conflicting reports. Dioxin uptake by wildlife onsite,
however, can occur regardless of dioxin content of vegetation.
Animals are susceptible to dioxin uptake through conventional
pathways including ingestion, inhalation and direct contact.
Dioxin contamination has been detected in biota samples collected
from Times Beach.
The literature contains a number of human health studies which
draw conflicting conclusions. A number of these studies were
cited by the commentor. The commentor states that "of greatest
significance is the study performed on 104 residents of Times
Beach" conducted by CDC, Missouri Division of Health,
st. Louis University, and st. Joseph's Hospital. This article
actually states:
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"The results appear negative, but no overall
definitive conclusion should be based solely
on this initial study."
The article further states:
"Public health policy in situations such as this
environmental contamination with TCDD must
continue to focus on the prevention of any
potential health effects (particularly delayed
or long-term), even if effects are not demon-
strated in a pilot study. For this reason
appropriate efforts to prevent human exposure
must continue, in this and other similar
situations, until a more complete under-
standing of public health risks is obtained."
In 1986, the Centers for Disease Control provided to Congress a
"Detailed Response to Subcommittee Questions on Dioxin." In
the:.y :-esponse to a question on the current extent of knowledge
concerning the. human health effects, CDC stated that:
"A number of epidemiology studies and health
assessments. in humans have given negative
results. For various reasons, the results
of these negative studies are not convincing,
particularly because of the overriding effects
of confounding variables."
CDC further states that:
"The lack of definitive human data forces the
use of animal data for predicting possible
human health effects."
and:
"... in the absence of useful human data to
the contrary, prudent public health policy
dictates an assumption that humans could
suffer effects similar to those observed
in animals and that preventive public
health policy must be based on available
animal data."
The 1984 risk assessment which supports the recommendations for
cleanup levels at Times Beach is based upon animal health
studies. This assessment has been consistently applied during
the cleanup of dioxin sites in Missouri, and remains valid for
remediation of the Times Beach site.
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COMMENTS RBCBZVED PROM THE STATE OP MZSSOURZ
Comments on the Proposed Plan were received from the Missouri
Department of Natural Resources (DNR). These comments and the
corresponding EPA responses are included in this section.
DNa believes incineration has been demonstrated to
be a safe and effective method for destroying
dioxin. EPA's proposed plan meets the state
objective of offering a long-term permanent
solution to the dioxin problem.
EPA agrees that thermal treatment is safe and effective at
destroying dioxin contamination.
DNa believes that consideration of the opinions and
reaction of local residents, as well as experts, is
integral to the decision-making process.
Public participation is an important component of the remedy
selection process under CERCLA, as amended. The CERCLA .
requirements for public involvement have. been met or exceeded
during the remedy selection process for Times Beach and
Minker/stout/Romaine Creek. All comments received from the
public have been considered in the selecting a remedy for Times
Beach and the Minker/Stout/Romaine Creek sites. All such
comments received are included in this responsiveness summary
with a corresponding explanation of how each comment was
addressed in the remedy selection process.
The State commented that .their support for the
facility is dependent upon EPA's execution of a
legally enforceable document with the state and
surrounding communities that assures:
Design and construction of a solid waste
landfill for the debris at Times Beach will
co..ence immediately, and debris removal will
begin when the facility can accept waste
A termination date for incineration at
Times Beach
A limitation on the number of sites and/or
volume of material to be treated at Times
Beach
AD agreement to transport contaminated
material only during non-peak hours
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Availability ot a technical assistance
qrant to the surroundinq community tor the
purpose ot independent monitorinq ot the
project
section 121(e) (2) of CERCLA provides in pertinent part that: "a
State may enforce any Federal or State standard, requirement,
criteria, or limitation to which the remedial action is required
to conform under this Act in the United states district court for
the district in which the facility is located. . ." Also, both
RCRA and CERCLA have citizen suit provisions at section 7002 of
RCRA and Section 310 of CERCLA. Section 121(d) (3) of CERCLA
provides in pertinent part that: "In case of any removal or.
remedial action involving the transfer of any hazardous substance
or pollutant or contaminant offsite, such hazardous substance or
pollutant or contaminant shall only be transferred to a facility
which is operating in compliance with section 3004 and 3005 of
the Solid Waste Disposal Act (or, where applicable, in compliance
with the Toxic Substances Control Act or other applicable Federal
law) and all applicable State requirements. . . ."
The thermal treatment unit to be located at Times Beach will need
to be permitted under RCRA because hazardous substances from
other sites will be brought to Times Beach for treatment. The
State is expected to limit the duration of the permit to a fixed
term of six years. The fixed term duration of the permit would
be enf~rcible by. the state and citizen suit. .
The ROD states that design and preparations for award of a
contract for the cleanup of the structures and debris in
uncontaminated portions of the site will begin immediately upon
ROD signature. These specific areas, which generally include the
most highly visible area adjacent to Interstate 44, are defined
in the ROD.
Cleanup of the dioxin-contaminated soil must be completed prior
to disposal of structures and debris in contaminated portions of
the site, due to the requirement that all remedies implemented
under CERCLA authority must be cost-effective. Performing the
demolition and disposal activities while still in contaminated
areas would substantially increase the cost of the project due to
the need for protective equipment, decontamination requirements,
and other precautions which must be taken when working in
contaminated areas. Disposal of structures and debris in these
areas will be initiated immediately upon removal of contaminated
soils.
The ROD defines the limitations on the number of potential
sources of soil to be treated at Times Beach. These sources are
listed in Table 1 of the ROD. The ROD also limits the duration
of the project to six years after receipt of a permit from the
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state for the thermal treatment unit. The duration of a permit
issued for thermal treatment under RCRA is limited by federal
regulations to ten years (40 CFR 270.50). EPA will seek a permit
for operation of the thermal treatment unit which is limited to
a period not to exceed six years.
As described in the Record of Decision, a detailed transportation
plan will be developed prior to design which will specify safety
precautions to be implemented during transport, including use of
non-peak hours only. O~her precautions which will be evaluated
include selection of transportation routes, safety contingency
plans, continuous radio communication, and use of escort
vehicles. The transportation plan will be developed in
coordination with local officials to assure that the concerns of
the impacted communities are addressed.
Technical assistance grants of up to $50,000 are available to
qualifying citizen's groups for the purpose of obtaining
assistance in interpreting information related to cleanups at
Superfund sites. Over 1000 Information packages containing a
fact sheet and federal register notice describing the
availability of these technical assistance grants were mailed to
identified interested parties, including local officials and
citizens, in late March, 1988~ EPA would support an application
for a grant to the local community in order to assure effective
public participation in the design and implementation of the
remedy.' .
The state opposes transport of any material to
"Times Beach from sites located outside Missouri.
As stated in the Proposed Plan and Record of Decision, only
dioxin-contaminated materials from designated locations will be
transported to Times Beach for treatment. Under no circumstances
would EPA consider transport of out-of-state wastes to Times
Beach for management. The state-issued permit for the thermal
treatment unit will also limit the sources of material which can
be accepted at Times Beach.
The stat. commented that since protection of the
soil cover vas an integral component of the in-
place containment alternatives, the degree of
required maintenance. and protection for the soil
cover in the proposed remedy is unclear.
For in-place containment alternatives, the cap or cover
represents the primary means of protection of human health and
the environment. Any breech in the cap or cover would expose
soil contaminated in excess of health-based levels. The
continued integrity of the cap is therefore critical to assure
the continued effectiveness of in-place containment remedies.
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The proposed remedy does not constitute an in-place containment
alternative. The proposed remedy includes excavation and
treatment of all soils exceeding a level of concern for
protection of human health. The soil layer represents an
additional measure of protection, and a means to control
potential offsite migration and environmental exposure to
residual contaminant levels. Although this potential exposure is
.of concern due to the possibility for the process of
bioaccumulation to occur, previous testing of Meramec River
sediment and biota has not determined that Times Beach is a
significant source of dioxin contamination in the river.
Maintenance of the soil cover is therefore not critical to the
continued effectiveness of the proposed remedy, and monitoring
and maintenance requirements are less stringent than for in-place
containment alternatives. This determination is stated in the
Record of Decision.
The degree of monitoring and maintenance typically associated
with a public park is adequate for the soil cover included in the
proposed remedy. An appropriate program would include periodic
surveillance, and stabilization through sodding, reseeding, or
other means, of any areas exhibiting significant erosion.
Isolated breeches in the soil cover would not be of concern,
since adequate protection is achieved by ,removal of contaminated
soil. .
The state requested clarification of the types of
land use restrictions which would be required
following implementation of the proposed remedy.
Land use restrictions will be required to ensure that future land
use remains consistent with the proposed remedy. The four-party
agreement for the permanent relocation of residents and
businesses at Times Beach includes provisions which require that
state and federal health agencies must concur with any proposed
use of the site following the cleanup. The state Registry of
Confirmed Uncontrolled or Abandoned Hazardous Waste Disposal
sites also controls future land use at Times Beach. Additional
deed restrictions or local zoning ordinances may be implemented
to ensure that land use remains consistent with the level of
cleanup and local interests.
As noted in the Proposed Plan and Record of Decision, the
contamination at Times Beach is present along certain specific
roadways representing a relatively small portion of the entire
site. Only 2 percent of the entire site area currently exceeds
20 ppb. Continuing land use restrictions will not be necessary
for all portions of the site following the cleanup. It is
possible than that different land uses may be allowable in the
future in different areas if the appropriate health-based
criteria are not exceeded. For example, following the cleanup, a
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large portion of the site will actually achieve residential
cleanup criteria, although residential development is considered
unlikely, even if acceptable to state and Federal health
agencies, due to the frequent flooding of the Meramec River.
Residential land use is an example of a type of usage which would
not be allowable in certain portions of Times Beach following the
cleanup. It is not possible to define every conceivable type of
land use which would not be appropriate for Times Beach.
Decisions regarding allowable future use must be made on a case-
by-case basis in consideration of exposure potential. The
existing institutional controls provide an effective mechanism
for assuring that future land use remains acceptable to state and
Federal health agencies, by requiring their concurrence on
proposed land use changes.
The state believes that EPA should commit to a
review of the remedy every 5 years, as provided by
Section 121 of the Superfund Amendments and
Pe1'uthorization Act of- 1986 (SARA).
According to section 121 of SARA, a review of the effectiveness
of the remedy is required no less often than every 5 years for
remedial actions which result in hazardous substanqes remaining
at the site. The intent of Congress in requiring such review was
to assure the continued effectiveness of containment remedies.
EPA interprets this requirement to apply to-remedial actions
which result in hazardous substances remaining at the site at
concentrations exceeding health-based levels for unrestricted
use.
The degree of cleanup proposed for Times Beach corresponds to a
specified non-residential land use. Protection of human health
is assured by existing institutional controls which place
restrictions on future land use at the site. The continued
effectiveness of the remedy is therefore dependent on the ability
of these institutional controls to restrict future land use to
that consistent with the degree of cleanup. A five year review
will be conducted as a component of the proposed remedy.
In the event that additional information regarding the toxicity,
mobility, or other characteristic of dioxin is discovered at a
future date, CERCLA allows for a re-evaluation of the remedy in
consideration of the new information. Section 121 of SARA
requires EPA to take action if it is determined that additional
response is necessary to protect human health and the
environment.
The State requested an explanation of the reason
that the decision to transport the dioxin-
contaminated soil currently in storage at the Quail
Run and Castlewood sites is not included in the
,
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Record ot Decision for the Times Beach and
Kink.r/stout/Romaine Creek sites.
The National Contingency Plan (50 FR 224, November 20, 1985)
establishes procedures for remedy selection and expenditure of
Superfund moneys. These regulations differentiate between .
response actions that can be taken at sites appearing on the. NPL
- and those sites not Oil the NPL. The response that is proposed
for Times Beach and Minker/Stout/Romaine Creek, both NPL sites,
is a remedial action, which can only be conducted at sites
appearing on the NPL. Since Quail Run and Castlewood do not
appear on the NPL, they are not eligible for remedial actions,
and must instead be responded to under the removal authority of
CERCLA, as defined by the NCP. Response actions to be
implemented at Quail Run, C~stlewood, and the other non-NPL sites
designated in the Proposed Plan and Record of Decision for Times
Beach and Minker/stout/Romaine Creek will be conducted as removal
actions which are selected by a decision document called an
Action Memorandum. The state is not required to provide matching
funds for a removal action, which is a pri~ary difference between
removal actions and remedial actions.
EPA has recognized the need tor immediate response at the Quail
Run and Minker/Stout/Romaine Creek site by conducting removal
actions for excavation and containment of dioxin-contaminated
soils at both sites. The potential for migration and exposure'
has been controlled by-these actions. These response actions are
interim actions, and EPA does not intend to defer final action at .
these two sites. The excavated material in storage at Quail Run
and Castlewood will be important in minimizing down-time of the
thermal treatment unit by allowing continual operation during
periods when excavated soil is not available from other sites due
to weather or other interference. For this reason, decisions
regarding final management of this material must be made in the
early phases of the project.
The state requested EPA to consider removing soils
at Times Beach exceeding 10 ppb in order to reduce
the number of land use restrictions necessary for
Times Beach, and expand the range of potential uses
for the site following clean up. The state would
not propose using Times Beach for residential
purpo... due to floodplain restrictions.
An action level of 20 ppb has been established for Times Beach on
the basis of recommendations from the Agency for Toxic Substances
and Disease Registry (ATSDR). As an additional measure of
protection, a one-foot layer of clean soil will' be placed over
all areas exceeding 1 ppb. This level of cleanup will assure
protection of human health for anticipated future uses of the
site. Removal of soil between 10 and 20 ppb is not necessary for
the protection of human health and the environment, and therefore
does not represent a justified use of Superfund money.
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The level of cleanup proposed for Times Beach will not unduly
restrict potential future uses of the site. EPA agrees that
future residential use is not feasible due to the frequent
flooding which occurs. Most non-residential uses of the site
would not be restricted. certain types of agricultural use would
not be allowed following the proposed cleanup; however, these
agricultural uses would also be restricted if soils exceeding 10
ppb were removed. Removal of soils exceeding 10 ppb would not
enable broader use of the site than would be allowed by the
proposed cleanup, due to use restrictions resulting'from the
frequent flooding of the Meramec. Floodplain restrictions will
have paramount control over future, land use, and will not be
, affected by lowering the cleanup level. ,"
The state commented that the ATSDR advisory
concludes that a 33 fg/kg b.w./day dosage
corresponds to commercial exposure where only 10%
of the site is contaminated at 20 ppb.
In correspondence of July 30, 1987, from ATSDR to EPA, the
rationale for a 20 ppb action level at commercial settings was
explained. The average lifetime daily dose was reduced by a
factor of 10 since it was assumed that only one-tenth of the site
was contaminated at 20, ppb. '
In the case ,of Times Beach, it is appropriate to factor this
reduction in the calculation of average lifetime daily dose
because only a portion of the entire site is contaminated.
Recent testing has concluded that actually only 2 percent of the
entire 480 acre site is contaminated at levels exceeding 20 ppb.
Therefore, following the proposed cleanup, only 2 percent of the
site will have a residual level of 20 ppb dioxin. The assumption
that 10 percent of the site is contaminated at 20 ppb is
therefore conservative, and results in an overestimation of the
average lifetime daily dose that could actually occur following
the cleanup.
It should be noted that the 1984 assessment by the CDC reported a
range of average lifetime daily doses corresponding to a
1/1,000,000 added cancer risk of 28 to 1428 fg/kg b.w./d. This
study reported that "the best estimate of a daily dose at 1 ppb
in residential soil (assuming uniform distribution of TCDD in
soil at 1 ppb) is calculated to be 44.6 fg/d (or 636.5 fg/kg
b.w.jd for a person weighing 70 kg)." Because of the range of
the estimated Virtually Safe Dosage (VSD) and the unlikelihood
that all of the conservative assumptions will be realized, the
authors concluded that residential soil levels greater than 1 ppb
pose a level of concern. Therefore, even if 100 percent of a
commercial site is contaminated at 20 ppb, the calculated
lifetime average daily dose of 330 fg/kg b.w.jd is" approximately
half of the calculated lifetime average daily dose for
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residential soils contaminated at 1 ppb.
The stat. commented that on-site disposal [of non-
hazardous solid waste] will have to comply with the
~issouri Solid Waste Management Lav and
Requlations, in addition to RCRA Subtitle D
requirements, and that any onsite landfill must be
flood-protected.
The Record of Decision for Times Beach will specify that on-site
disposal will be conducted in accordance with the Missouri Solid
Waste Management Law and Regulations. Also, landfills
constructed on- site will be protected from flooding using
appropriate measures to ensure that floodwaterdo~s not contact
solid.waste. -
The State commented that the ARARs discussed in the
Times Beach Feasibilitv study tor air pollution
control should be included in the Proposed Plan and
Record ot Decision.
As described in the feasibility study, ARARs associated with air
pollution control include provisions of the Clean Air Act, which
is currently administered by MDNR. Provisions of the Clean Air
Act which have been delegated to st. Louis County would also be
. considered ~s.
RCRA performance standards are generally ~ore stringent than new
source performance standards under the Clean Air Act. Emissions
of some of the more conventional pollutants are not addressed by
RCRA. Emissions of these conventional pollutants are regulated
by the Clean Air Act.
The state advised EPA that they are planning to
develop an air toxics program in the near tuture
which vill be more stringent .than tederal
requirements.
The Proposed Plan and Record of Decision can not evaluate
requirements which do not yet exist. The Record of Decision
evaluates all identified ARARs currently in existence. Newly
established requirements which represent potential ARARs will be
evaluated for impact on the proposed remedy when they are
published or otherwise provided to EPA.
The state commented that the discussion ot Missouri
Water Quality criteria is incorrect.
The State has adopted numerical water quality standards for
dioxin under the Missouri Clean Water Law (10 CSR 20-7.031). The
standard for protection of human health is 0.00013 nanograms per
liter (ng/l). The standard for protection of aquatic life is
0.000014 ng/l. These standards are below analytical detection
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limits and apply primarily to discharges with detectable dioxin
levels. The criteria are compared to the discharge concentration
divided by a dilution factor calculated from the flowrate of the
receiving river. If dioxin can not be detected in the discharge,
the standards have no application. None of the alternatives
evaluated in the Proposed Plan or Record of Decision involves
discharge into waters of the state. Therefore, Missouri water
quality criteria do not constitute ARARs for this remedy
selection.
The state recommends land application of wastewater
at or below "consumptive rates". If consumptive
rates are exceeded, an NPDES permit would be
required for discharqe int~ the Meramec River.
The state recently published regulations concerning land
application which are expected to become effective prior to
implementation of the selected remedy. These regulations require
a state operating Permit for land application of industrial
wastewater. This permit is similar to an NPDES permit, which
would be required if wastewater were discharged directly into the
Mer,,\n.e~ River or land appl-ied at a rate exceeding the
infiltration capacity of the ground. An engineering report must
be prepared in order to obtain a state Operating Permit which
demonstrates the acceptability of the proposed discharge.
. .
The state commented that wastewater must be
delisted prior to ~and application.
All residue from the thermal treatment unit must be delistable,
including wastewater and treatment residue (ash). If these
materials are not delistable, they must be managed as a hazardous
waste, which would invalidate the cost-effectiveness of the
proposed remedy.
The state commented that an operatinq Solid Waste
Disposal Area Permit will be required from MDNa, in
addition to any local approvals for onsite land
disposal. '
As explained in the proposed Plan and Record of Decision, onsite
land disposal 'of non-hazardous solid waste will be performed in
compliance with provisions of the Missouri Solid Waste Management
Law. For onsite actions, CERCLA exempts EPA ,from the requirement
to obtain permits, however all substantive provisions of the
permitting regulations must be met.
Delisted residue resulting from the thermal treatment of a
hazardous waste is considered a newly generated onsite solid
waste. This is true for residue resulting from treatment of both
onsite and offsite hazardous wastes. The onsite disposal of this
material constitutes an onsite action, and exempt under CERCLA,
as amended, from administrative permitting requirements, which
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includes the need to actually obtain the permit itself. All
substantive permitting requirements must still be met. Despite
the exemption from administrative permitting requirements for
onsite actions, EPA will seek a permit from the state for land
disposal of delisted residue from the thermal treatment process
in order to assure the state and public that the disposal will be
implemented safely. All administrative and substantive state
permitting requirements will be achieved prior to disposal.
The disposal _of structures and debris located onsite at Times
Beach also constitutes an onsite action, and is exempt from
administrative permitting requirements. This material will be
disposed of in accordance with all substantive state permitting
requirements. The exemption from administrative permitting
requirements will enable EPA to immediately initiate design and
construction of the disposal facility for the disposal of onsite
structures and debris following remedy selection, with no
permitting delays.
Local approvals are generally not considered ARARs, unless they
are delegations of state or- federal programs. st. Louis County
Clean Air Requirements are an example of a state-delegated
program. Since local ~olid waste disposal requirements are not
delega~ions of State or Federal programs, EPA is not required to
obtain local approval prior to disposal. EPA will coordinate the
design and construction of the disposa-l unit (s) - to ensure that
-the substantive requirements are met.
The state clarified the definitit>n of a "special
vaste" as "any solid vaste requiring h&nd1ing other
than normal use municipal vaste".
This definition of a special waste will be incorporated into the
Record of Decision.
The state- commented that a statement in the
Proposed Plan could be interpreted to imply that
areas left at 20 ppb may not be covered vith one
foot of clean soil.
All areas within Times Beach exceeding 1 ppb, but less than 20
ppb, will be covered with a minimum of one foot of clean soil.
All areas contaminated at 20 ppb or greater will be excavated
until cleanup criteria is achieved, and backfilled with at least
one foot of clean soil, or to original grade where excavation
exceeds one foot.
The state suggested that locating the thermal
treatment unit further from the railroad may be
more acceptable to Eureka.
EPA has evaluated locating the thermal treatment unit in the
northwest portion of Times Beach in order to minimize the impact
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on upstream and downstream flood heights and reduce visibility
from the interstate highway. This area is also largely
uncontaminated, which would reduce the volume of soil which would
require removal prior to construction of the ring levee. EPA has
no intention of using the railroad to transport hazardous waste
to Times Beach for treatment.
The final location for the thermal treatment unit will be
determined during the design phase. EPA would not object to
locating the thermal treatment unit in another portion of Times
Beach, if the proposed area would not require removal of an
excessive volume of contaminated soil prior to construction, and
would not significantly impact upstream or downstream flood
heights. The local communities will be given the opportunity to
participate in selection of a location for implementation of the
project. -
The state commented that a RCRA Part B permit will
be required prior to construction of any facility
required to obtain such a permit.
EPA agrees that a RCRA Part B permit for treatment of offsite
material will be required prior to construction. This will be
clarified in the Record of Decision.
.The state commented that implying that a petition
is required to change land use for a property on
the Registry of Confirmed Abandoned or Uncontrolled
Hazardous Waste Disposal sites may be overstating
the process.. only a request to the department
director is required, and the use change does not
have to be acceptable to federal health agencies.
The language in the Record of Decision will-be modified to state
that the director must approve a request to change the use of a
site appearing on t~e state registry.
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SECTION A
TIMES BEACH FEASIBILITY STUDY
This section summarizes comments received during the public
meeting held February 12, 1987, and the comments received
subsequent to the meeting, in response to the report titled
Public Comment Draft Feasibilitv StudY for the Times Beach site.
Times Beach. Missouri.
QUESTIONS
At the meeting, there were several questions regarding the
cleanup and proposed alternatives.
Concern was expressed about the proximity of
decontamination facilities at the site to homes,
the stirring up of TCDD-contaminated material.
during remedial activities, and accidents that
might occur during tbe remediation.
EPA shares these concerns and intends to take measures to prevent
exposure of local citizens and site workers to the contaminated
soil. Although a thermal treatment operation was conceptually
described in the feasibility study, no formal decisions have been
made about the location of a thermal treatment unit or support
facilities at the site. During planning and implementation of
the remedial activities, safety measures will be considered to
minimize the risk of dioxin exposure to the local population.
The measures will include onsite and offsite air monitoring. The
location of decontamination facilities, safety measures required
to prevent accidents, and site monitoring plan will be developed
during the planning phase.
Several people expressed support for an alternative
remedial approach that would entail capping of the
contaminated soil with an impermeable membrane,
placement of a clean soil cover over the membrane,
and landscaping and fencing of the site.
At the request of those proposing this remedy, an alternative was
evaluated in the Proposed Plan consisting of placement of an
impermeable barrier and soil cover over contaminated areas. The
guidelines for selection of remedies at sites is provided by
CERCLA, as amended by the Superfund Amendments and
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Reauthorization Act of 1986 (SARA). EPA believes that the approach of
capping the site, while technically viable, does not meet the
requirements of CERCLA, as amended, to the same extent as thermal
treat~ent of the contaminated soil. Capping does not attain all
identified ARARs, is less protective, and does not satisfy the
SARA preference for permanent remedies or remedies involving
treatment of wastes. Thermal treatment has also been determined
to be more cost-effective than capping alternatives.
A commentor asked about plans to open the South
outer road to improve access to the highway system.
Following completion of the remedy at Times Beach, EPA will not
object to reopening the south outer road to through traffic, if
acceptable to federal and state agencies.
One person asked about the possibility that the
project could be started and then funds would run
out.
Although it is not possible to foresee all possible future
regarding funding for the various government projects, EPA
confident that adequate funding will be available over the
duration of the project.
One commentor, who wished to cut some wood at Times
Beach, expressed frustration at the requirements
. that were. placed on such an activity. The
commentor emphasized that these standards should
not be less than what EPA itself must follow at the
site.
events
is
EPA believes that special requirements must be placed on certain
activities at Times Beach to prevent contact with TCDD-
contaminated soil by persons onsite or offsite. These measures
have been implemented to protect the health of the public and
must be enforced. EPA follows very strict procedures while
conducting work at the site to prevent contact with contaminated
material.
several people expressed concern about the health
effect. of exposure to TCDD.
A response to these questions was made at the public meeting by a
member of the Agency for Toxic Substances Disease Registry.
Research continues in this area and EPA is confident that a
better understanding of the health effects of exposure to TCDD
will come in the future.
Several people asked about the plans for Times
Beach following remediation. One commentor
questioned whether you could apply the results of a
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2-3
feasi~ility study without knowing the future use of
the site.
The use of the Times Beach site following the completion of
remedial activities has not been determined. Future land use at
Times Beach will be dependent upon the extent of the cleanup and
recommendations of state and federal health agencies. It is the
intent of EPA to reduce the restrictions on site use that
currently exist.
One '~erson asked how deep you would have to dig if
you were to remove the TCDD-contaminated soil and
incinerate it.
The depth of excavation would vary with the level of contam-
ination at depth. Sampling conducted to date indicates that the
contamination is primarily limited to the upper 6 to 12 inches of
soil in the roadways. The excavation procedures that would be
followed are described in the Proposed Plan.
EP~ was asked ~out the amount of soil that would
be thermally treated and the time required to.
incinerate the material. The commentor went on to
ask ~out the time required to cap certain areas at
the site.
Information on the remedial action alternatives, such as that
requested by the commentor, is included in the Proposed Plan.
The volume of contaminated soil at Times Beach is estimated at
13,600 cubic yards. An estimated 12,000 cubic yards exist at the
Minker/Stout/Romaine .Creek site. The total volume of
contaminated soil at all eastern Missouri dioxin sites is 92,200
cubic yards. Implementation times are discussed in the Proposal
Plan.
One person asked ~out the status of information
that she had requested from EPA under the Freedom
of Information Act.
EPA provided a written response to the Freedom of Information Act
request referred to by the commentor. The requested information
was provided in a letter to Donald E. Meyer on March 19, 1987.
One commentor emphasized to EPA that the remedial
method chosen should minimize the opportunity for
run-off of contaminated soil into the Meramec
River.
Measures will be taken during implementation of the remedial
action at Times Beach to minimize erosion of contaminated soil
into the Meramec River.
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2-4
One person asked abou~ pos~ing of ~he Cas~lewood
are. and rezoning of a sawmill in ~he area. In
par~icular, ~he commen~or was concerned abou~
po~en~i.l exposure of ~he ci~izeDs ~o con~amina~ed
dus~ raised by ~rucks ~raveling along ~he roads in
~he area.
Removal actions at the Castlewood area have been completed.
contaminated soils present at levels considered to present a
potential risk to public health were excavated and placed in
interim storage onsite. EPA believes that the concerns expressed
by the commentor were adequately addressed by completion of
removal actions at the site.
ODe person ques~ioned whether ~hermal ~reatmen~
could be used successfully ~o des~roy ~he dioxin.
Dioxin-contamination has been successfully destroyed in soils by
thermal treatment using pilot scale thermal treatment units at
Times Beach and by the EPA mobile incinerator at the Denney Farm
site in Southwest Missouri. More recently, an ongoing
remediation program at Johnson Atoll using a full-scale mobile
incinerator to treat TCDD-contaminated soil has been successful.
EPA believes that the technology is well-demonstrated and could
be successfully used at Times Beach.
GENERAL ISSUES
Following the public meeting, many comments were received
regarding the feasibility study and issues discussed at the
meeting. These comments and their associated responses are
listed below.
Some people were concerned tha~ an incinera~or,
once ins~alled, would become a permanent facili~y,
and receive a varie~y of hazardous was~es.
EPA has made a public commitment to ensure that the incinerator
is only a temporary facility, to be used only for treating dioxin
contaminated materials from the eastern Missouri sites. The
Record of Decision will clearly state that the incinerator is to
be temporary. Conditions of the Record of Decision are
enforceable through SARA citizen suit provisions. The State
will also have control over the sources of material to be treated and
duration of the project through conditions of the state-issued
permit. The incinerator will be installed under contract by a
private firm, and that contract will include the necessary funds
for dismantling and removing the incinerator from the site, once
the soil and other debris are treated.
Some people sugges~ed tha~ ~he con~amina~ed soil be
excava~ed and taken elsewhere.
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2-5
The Feasibility study considered an offsite disposal alternative,
and calculated order-of-magnitude costs for such an approach.
However, there are no offsite disposal facilities which currently
have a permit which allows the acceptance of dioxin
wastes. EPA has periodically contacted the several
facilities around the country, and has not found an
disposal location.
contaminated
commercial
alternative
Several people, including the City of Eureka,
Missouri, noted that considerable development is
taking place in the ar~a"around Times Beach. These
people generally expressed concern that locating an
incinerator in Times Beach might harm the progress
of that development, especially development as a
recreational area.
EPA is sensitive to the concerns expressed. The Agency believes
that a thermal treatment facility can be designed and installed
in a way that will not harm or slow the development of the area.
EPA is committed to working with all interested parties in "
designing, building, and locating the treatment facility on the
site in a way that will make it less objectionable and minimize
visibility from the adjacent interstate highway.
Some people stated that thermally treating the
wastes is not necessary, or that it would not be a
reasonable use of government funds.
EPA believes that the additional protection of human health and
the environment offered by treatment justifies the additional
expense relative to other alternatives evaluated. No other
alternative provides an equivalent degree of protection at a
lower cost. It is therefore the determination of the Agency that
thermal treatment represents the most cost-effective remedy for
Times Beach and the Minker/Stout/Romaine Creek site of the
alternatives evaluated in consideration of the potential need for
response at the other eastern Missouri dioxin sites listed in the
Proposed Plan.
Some people expressed the belief that "it would be
best to leave the soil undisturbed.
As pointed out in the Times Beach Feasibilitv StudY and Proposed
Plan, excavation of the soil will increase the short-term
potentials for exposure to and offsite migration of the
contaminated soil. However, this short-term risk would be
anticipated and controlled. If the soil is left, the potential
for release and long-term exposure would continue indefinitely,
since natural processes have not been observed to result in
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2-6
significant reductions in contaminant concentrations.
One person suggested placing the contaminated soil
in bunkers, arranged as a floodwall.
From the point of pure, technical feasibility, this approach
could be taken. However, there is not nearly enough contaminated
soil at Times Beach to construct a floodwall along the entire
length of the river frontage at Times Beach. The remainder of a
floodwall would have ~o be constructed of uncontaminated soil.
The cost to complete a floodwall, and the additional costs of
arranging the bunkers along the river (instead of in a more
efficient grouping) would substantially increase the cost of
containment. The additional funds required to complete such a
'floodwal~ would not represent a justifiable expenditure of CERCLA'
funds.
.Some people were in favor of u~ing an incinerator
to treat the contaminated soil; and .some of these
people were also in favor of bringing the
contaminated soil from the other residential sites
to Times Beach for treatment.
EPA also believes that this is the best approach for the diQxin
sites in eastern Missouri. A balanced look at all of the
advantages of a thermal treatment indicates that it is' superior
to the other alternatives examined in the Feasibility study and
Proposed Plan.
One person, while generally supporting the concept
of incineration, stated that the mobile .
incinerator, which has been used in southwestern
Missouri to treat dioxin contaminated soil, would
not be acceptable at Times Beach. The person
stated further that EPA should consider use of a
particular company's incinerator (Shirco), because
it would at least seem more temporary.
EPA agrees tpat the mobile incinerator used in southwestern
Missouri is too small to consider for use at Times Beach. While
that incinerator has recently been modified to greatly increase
its capacity, it is still not capable of treating the volume of
soil at Times Beach and the other residential sites in an
acceptable time period. .
EPA is not proposing any particular thermal treatment technology
or particular vendor of treatment units at this time. Thus, both
incinerators and non-incinerator types of thermal treatment units
are being equally considered. It will be up to the firms which
submit proposals and bids for the work to propose particular
treatment technologies.
One person argued against the idea of capping the
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2-7
contaminated soil in-place, because that would
require the longest period of monitoring.
Long-term monitoring costs represent a significant disadvantage
of all of the alternatives except off-site disposal (which is
unfeasible because of the lack of a permitted facility) and
permanent thermal treatment. . In fact, the elimination of the
need for long-term sampling and analytical monitoring, which is
very expensive, is one of the most important advantages of
thermal treatment. Long-term sampling and analytical monitoring
is not required for thermal treatment options because the
contamination is permanently destroyed. Long-term surveillance
and cover maintenance costs associated with thermal treatment of
soils exceeding 20 parts per billion dioxin are minimal relative.
to the potential cost of cap maintenance and sampling and.
analysis for in-place containment alternatives.
One person, who represents a vendor of compressed
gases, recommended use of oxygen-fed incineration.
As noted elsewhere in this responsiveness summary, EPA is not
examining specific treatment technologies at this time. EPA is
considering general approaches for the cleanup at Times Beach and
for the management of any resulting wastes. After the Record of
Decision is final, EPA will issue a request for proposals. At
that time, firms sUbmitting proposals and bids will be free to
consider oxygen-fed incineration and propose its use if they see
advantages in it.
One person, who represents a hazardous waste
management consortium, recommended solidifying the
soil at Times Beach, transporting it to Texas in
solid form, crushing the solidified soil and
converting it to a slurry, and then injecting it
into a salt dome where it would solidify once
again, and be permanently trapped.
EPA sees several difficulties with this proposal, anyone of
which would delay a cleanup at Times Beach for some time. One of
the most significant is the need for the salt dome facility to
have a RCRA permit that would allow injection of dioxin into the
formation. Acquiring such a permit could require two or more
years, or may not be possible. Long-term management of the
contaminated soil would still be required. Less expensive land
disposal alternatives were evaluated in the feasibility study and
Proposed Plan which offer a similar degree of protectiveness.
One person made a proposal with the following main
features: (1) The dioxin contaminated soil would
be consolidated somewhere in the southern portion
of the site. (2) The northern portion of
Times Beach would be excavated, presumably to the
depth of the water level in the Keramec River,
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2-8
and piled on top of the southern half of the
sit.. This would raise half the site out of
the floodplain, without decreasinq the capacity
of either the floodplain or the floodway. It would
also result in the dioxin being buried under"
about ten to fifteen feet of soil. (3) The
elevated portion of Times Beach would be
deeded to the Industrial Development corporation of
Eureka, Missouri.
There are regulatory, technical, and cost considerations which
make implementation of this alternative unfeasible. "
The major regulatory requirements would be those under the
Resource Conservation and Recovery Act. Those regulations would
require that the soil be placed in an engineered facility that
would contain the dioxin. Once the soil was contained in such a
facility, there would be no justification for excavating half the
sit~ a~d placing it on top of the facility. The additional
excavation would not represent a justifiable CERCLA expense. "
Other less expensive land disposal alternatives were evaluated in
the feasibility study and Proposed Plan which often an equivalent
degree of protection.
Several people expressed a concern that an
incinerator would contaminate the "Meramec River
with salt.
Water used for cooling and air pollution control
treated, tested, and stored pending verification
requirements for land application are achieved.
discharge of any material into the Meramec River
proposed by EPA.
would be
that state
No direct
is being
Some people stated that incineration is too
expensive when compared with the other alternatives
in the Feasibility study.
While it is true that incineration is more expensive, EPA
believes that the additional benefits offered by thermal
treatment, including permanent destruction of the contamination,
justify the additional expense. In other terms, EPA has decided
that thermal treatment represents the most cost-effective
alternative. This determination is documented in the Proposed
Plan and Record of Decision.
Two people suqqested buildinq a lake at Times
Beach.
The amount of soil that would be excavated at Times Beach is not
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2-9
sufficient to provide a basin for a lake. Dioxin has not
penetrated the soil very deeply at Times Beach. The samples EPA
has collected at Times Beach indicate that the contamination is
almost entirely limited to the upper 6 to 12 inches, and that it
is primarily under the roads which were sprayed with contaminated
oil. While the volume of contaminated soil is ~arge by some.
measures, it is less than the volume of even a small lake. The
additional cost to excavate a basin for a lake is not a
justifiable CERCLA expense.
Many people expressed a desire to have the debris
and abandoned houses at Times Beach cleaned up.
EPA is sensitive to the need to address the debris and structures
at the site. EPA has evaluated remedial alternatives for this
material in the feasibility study and Proposed Plan. The
Proposed Plan includes demolition and onsite land disposal of
structures and debris.
Some people expressed concern that an accident
might occur with the incinerator, resulting in
dioxin contamination being emitted to the
environment.
As with any large piece of machinery, it is necessary to
recognize that there is some potential for operational problems.
EPA believes that a careful and conservative design, together
with careful operation and oversight, can ensure safe operation.
Some thermal treatment technologies are less prone to operational
problems, or to release of contaminants in the event such
problems, than are others. EPA is aware of these differences, and
will take them into account in selecting the proposal and bidder
to construct and operate the thermal treatment unit at Times
Beach.
Many people argued in favor of capping the
contaainated soil in-place, rather than any more
aggr...ive cleanup effort. The City of Eureka has
expr....d a willingness to consider responsibility
tor the long-term care and monitoring that would be
required it the soil is capped in place.
EPA has evaluated in-place containment alternatives in the
feasibility study and Proposed Plan. Disadvantages of this
alternative include the need for long-term access restrictions,
long-term operation and maintenance costs, and the potential for
future release and exposure. A detailed evaluation of. this
alternative is provided in the Proposed Plan.
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2-10
One person, representing the Bureka Fire Protection
District, expressed safety concerns regarding the
current situation at Times Beach and regarding an
incinerator. Specifically, the person is concerned
with the amount of combustible materials at Times
Beach, and with the possibility that the Bureka
Fire Protection District would be responsible for
responding to any fires that might occur if an
incinerator is installed at Times Beach.
All remedial activities undertaken at the site will be in
accordance with an approved health and safety plan. One
objective of this plan will be to minimize the potential for
fires during implementation of the remedy. All areas within the
site will remain accessible by emergency vehicles at all times
during the cleanup of the structures and debris. All remedial
activities will be scheduled and carried out in coordination with
local emergency services so that service is not interrupted, and
emergency workers are aware of any special considerations for
responding to a situation at Times Beach.
Several people expressed concern about locating a
thermal treatment unit close to a highway.
EPA believes that locating the incinerator near a highway is
advantageous. The primary advantage is that truck traffic on
. secondary roads associated with the cleanup will be minimized.
The interstate highway system is designed for the loads that will
be involved, and the direct access which Interstate 44 provides
to Times Beach will ensure greater safety for the people in the
area.
Several people expressed concern about the steam
. that vill be produced by the incinerator,
specifically that the steam vill increase the
humidity in the area.
The amount of water that will be added to the air by the
incinerator will not measurably affect the humidity. The amount
of water produced by the incinerator will be too small, compared
to the amount of water that is naturally in the air, for this to
be a concern.
Several people opposed bringing dioxin contaminated
soil from other eastern Hissouri sites to Times
Beach~ .
While EPA understands the concern, another implementable
alternative for the soils at these sites has not been identified.
Many of the dioxin sites in eastern Missouri are too small to
erect onsite treatment units. Also, unlike Times Beach, many
other sites are currently occupied, which would result in safety
problems deriving from the truck traffic and additional site
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2-11
security cpnsiderations. These problems would be minimized by
bringing the soil to Times Beach. Another primary concern is the
cost of setting up a thermal treatment unit at each site which
would greatly increase the total costs and delay the cleanups.
SO.. people expressed concern about the risks posed
tor sit. workers in excavating and i~cinerating the
dioxin contaminated soil.
Short-term protectiun of workers during implementation is an
important consideration in selecting an alternative. EPA has
developed extensive and detailed requirements for its workers at
contaminated sites. Similar requirements have recently been
established"by the Occupational Safety and Health Administration
(OSHA) and are now national standards for all cleanup workers at
contaminated sites." EPA will require the cleanup contractor (who
has not been selected yet) to follow these rules which include
development of an Agency-approved site-specific health and safety
plan in order to ensure that the workers are not exposed to any
undue risks. "
Several people, including the City ot Eureka,
Missouri, recommended capping the contaminate~ soil
with an impermeable cap.
It:was not EPA's intention in the Feasibility Study to recommend
a permeable cap over an impermeable one. The study addresses
both, and concludes that either one is technically feasible.
Both types of caps offer advantages and provide some degree of
long-term protection. The permeable cap was used for the cost
calculations, but EPA has expressed no preference for one
particular type. .
Several people expressed concern regarding the
assumption made in the feasibility study that the
site might someday be used again as a residential
area. The people commenting were particularly
concerned that residential cleanup standards would
be used tor the site.
During preparation of the feasibility study, risk assessments
were performed for several future land use scenarios, including
residential usage. A residential scenario may be more
conservative than the actual future use of the site, but EPA
believes that it was appropriate for the purposes of the
feasibility study to make this assumption, which allowed a valid
comparison of remedial alternatives to be performed.
One person suggested that a commercial setting
along Lewis road is a more likely scenario for the
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2-12
future use of the site than a residential scenario.
Future commercial development at the site was considered in the
feasibility study and risks were calculated for such a scenario.
Several people expressed concern that the risks to
public health vere estimated too conservatively in
the feasibility study. These people suqqest that
the risks posed by the site are much less than
indicated by the estimates in the feasibility
study. .
The feasibility study evaluated public health risk in accordance
with EPA.'s Superfund Public Health Evaluation Manual. This
procedure results in a conservative estimate of the risk
represented under various exposure scenarios. EPA believes that
it is appropriate to consider this public health evaluation in
the remedy selection process for Times Beach.
Several people suqqested that levels of concern
different than the 1 ppb standard used in the
feasibility study vould be appropriate for cleanup
of the site. In particular, it vas noted that
hiqher levels should be used.
In 1984, Kimbrough, et al., recommended 1 ppb as a level of
concern in residential soils in "Health Implications of 2,3,7,8-
Tetrachlorodibenzodioxin (TCDD) contamination of Residential
Soils". This assessment concluded that different cleanup levels
may be appropriate in areas where residential exposure does not
occur. EPA has acknowledged this and has proposed a cleanup
level of 20 ppb at Times Beach on the basis of recommendations
from health agencies. Cleanup levels for Times Beach are further
discussed in the Proposed Plan.
One person noted that SARA expresses a preference
(in section 121 (b» for treatment alternatives
that permanently and siqnificantly reduce the
volume, toxicity, or mobility of the hazardous
substance, pollutants, and contaminants. The
person auqqests that cappinq of the site would
permanently reduce the mobility of the site
contaminants, and is therefore entitled to
preference.
The preference expressed in SARA is for treatment of hazardous
substances. The capping alternative, which does not involve any
treatment and which leaves the contaminants susceptible to
migration and exposure, is an example of the types of approaches
which are least preferable under SARA.
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One p.rson suggested that the removal and treatment
alternatives would render the Times Beach site
worthl....
EPA believes that following implementation of the proposed
remedial action, Times. Beach can be returned to beneficial use
including potential park areas, greenspace, or commercial
development.
Several people suggested that incineration was a
relatively speculative technology. It was further
suggested that the costs for incineration that were
developed in the Feasibility Study were too
optimistic and would likely be much higher,
particularly in light of the costs that were
incurred during incineration performed at the
Denney Farm site.
EPA believes that incineration is a well-developed technology for
treatment of contaminated material. The technology has been used
for To.any years and was successfully applied at the Denney Farm
site for destruction of dioxin in soils and liquids. The EPA
mobile incinerator operated at the Denney Farm site was not
originally designed or constructed to handle soils. The design
limited the capaqity which resulted in increased unit treatment
costs. The EPA mobile incinerator has been retrofitted with
equipment which is intended to increase the capacity a~d lower
the unit treatment cost. The cost to operate an incinerator
designed and constructed specifically for dioxin-contaminated
soils at Times Beach would be substantially lower. EPA believes
that the cost estimates presented in. the feasibility study and
Proposed Plan are representative of the costs likely to be
encountered for remediation at Times Beach.
POLICY ISSUES
The EPA received many comments regarding policy issues addressed
in the feasibility study.
One co..entor refuted the logic of the assumption
made ia the feasibility study that the site would
on. day b. returned to residential usage. The
commentor stated that since the site would not be
returned to residential usage, the application of a
one part per billion (ppb) action level is not
appropriate.
The feasibility study acknowledges that future residential use of
Times Beach is unlikely. The EPA believes that it is unlikely
that Times Beach will be returned to residential usage due to a
combination of de-facto institutional controls and practical
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2-14
considerations discussed in the Proposed Plan.
Future land use will be controlled by the extent of cleanup at
the site. The remedy described in the Proposed Plan will allow
land usages which include park or greenspace and potential
commercial development. All future land usage will be in
accordance with state and federal health criteria.
The assumption of residential land use is made in the Times Beach
Feasibility study in order to evaluate alternatives on an
equivalent basis. The EPA does not believe that changing the
actio. level will affect the screening or noncost evaluation of
alternatives in the feasibility study. If an action level
differing from 1 ppb is established for Times Beach, the
feasibi~ity study cost evaluation will require adjustment.
Revised cost tables for an action level of 20 ppb .appear in the
Proposed Plan.
The Feasibility study acknowledges that different action levels
may be appropriate for other land uses. CERCLA, as amended by
SARA, does not require that a specific future land use be
established prior to evaluation of remedial alternatives or
remedy selection.
One commentor stated that it was unreasonable to
believe that Times Beach would ever be developed'
for agricultural purposes; therefore, it is not
appropriate to perform a risk assessment for that
scenario.
Risk assessments were performed in the Times Beach Feasibility
Studv for several different future land uses at Times Beach
including agricultural, recreational, and occupational scenarios.
These risks were evaluated in order to characterize the risk to
public health if no remediation of the dioxin-contaminated
material at Times Beach is performed and the land is put to
various uses. The feasibility study does not discuss the
likelihood of the land use at Times Beach changing to any of the
particular scenarios developed.
One co..entor refuted the basis upon which 1 ppb
actioD level is established for residential
settings. The commentor stated that the
assumptions used to derive the l-ppb action level
were overly conservative and result in an action
level which is much too low.
The 1-ppb action level which is assumed in the feasibility study
is based upon the 1984 report entitled, "Health Implications of
2,3,7,8-Tetrachlorodibenzodioxin (TCDD) contamination of
Residential Soil," Renate D. Kimbrough, M.D., et al., Center for
Environmental Health, Centers for Disease Control (CEHjCDC).
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This action level has been applied during EPA removal actions at
several sites in Missouri and at other sites nationwide. The EPA
believes that the 1984 Center for Environmental health report is
a valid risk assessment upon which to base an action level. The
Center for Environmental Health has recently supported the paper
stating that no scientific evidence has been reported in the
literature to date which would invalidate the assumptions upon
which the 1984 risk assessment is based, or its conclusions.
One commentor stated that the consideration ot the
CEH/CDC health assessment to establish an action
level at Times Beach is not authorized, and that
the l-ppb level ot concern is not an appropriate
requlatory criterion. The commentor stated that
EPA should rely on a site-specitic health.
assessment to establish an appropriate action level
tor Times Beach.
The EPA is required to attain all applicable or relevant and
appropriate state and federal environmental requirements (ARARs).
Although the 1984 Centers for Disease Control Health Assessment,
upon which the l-ppb action level is based, is not an ARAR~ the
National Contingency Plan (NCP) allows such criterion to be
considered in the selection of a remedy. In the absence of other
regulatory criteria for dioxin, EPA believes that it,.is valid and
appropriate to base an action level on this assessment.
One commentor s~ated that action levels other than
1 ppb are appropriate tor residential and
nonresidential land uses. The comment or stated
that an action level should be established tor
Times Beach which corresponds to the anticipated
land use ot the site.
The EPA believes that residential land use at Times Beach is
unlikely, as acknowledged in the feasibility study and Proposed
Plan. The EPA agrees that it is appropriate to establish an
action level for Times Beach soils which corresponds to a
realistic anticipated land use for the site. . In 1986, EPA
initiated an evaluation of an appropriate action level at Times
Beach, in coordination with the Agency for Toxic Substances and
Disease Registry (ATSDR), Center for Environmental Health,
Centers for Disease Control, the Missouri Department of Natural
Resources (MDNR), and the Missouri Division of Health (MDOH).
The result of this evaluation was the recommendation by federal
and state health agencies of an appropriate action level for the
Times Beach site. EPA has considered this recommendation in the
establishment of a cleanup level and remedy selection for the
Times Beach site.
One commentor stated that overly conservative
assumptions are used to calculate risks tor the
three scenarios developed in the teasibility study.
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The procedures used in the Feasibility Study to calculate
incremental cancer risks are in accordance with EPA policy and
guidelines. Specifically, the procedures used conform to the EPA
Public Health Evaluation Manual (1986). The EPA believes that
the risk assessment procedures used in the Times ~each
Feasibilitv Study are valid and result in a reasonable estimation
of anticipated incremental cancer risks due to exposure in the
various scenarios cie,,'eloped.
One commentor stated that the cancer potency value
used to calculate risks in the feasibility study is
too high. .
The public health evaluation presented in the Times Beach
Feasibility study is performed in accordance with Agency
guidelines and policy. These guidelines specify that incremental
cancer risks will be calculated using cancer potency values
adopted by the.EPA Carcinogenic Assessment Group (CAG). The EPA
believes that the cancer potency value adopted by the CAG is
appropriate and supported by scientific data.
One commentor stated that additional factors
affecting the mobility of dioxin-contaminated soil
need to be considered in the selection of remedy.
for Times Beach.
The EPA believes that the vertical and areal extent of dioxin-
contamination has been adequately defined at Times Beach during
the past field investigations involving the sampling and analysis
of surface and subsurface soils. Sampling at Times Beach and at
other Missouri dioxin sites has indicated that the dioxin is
tightly bound to soil particles, and that migration of the dioxin
is directly related to the transport of the contaminated soils.
The EPA does not believe that the dioxin contamination at Times
Beach represents a significant threat to groundwater or air
quality on the basis of sampling conducted by EPA at Times Beach.
Sampling of sediment and biota in the Meramec River adjacent to
Times Beach do not indicate that the site is a significant source
of dioxin in surface water. The EPA believes that this empirical
information forms a valid basis for the selection of a remedy at
Times Beach and has considered the observed mobility
characteristics in the remedy selection.
One commentor stated that the health and
environmental risks associated with dioxin are less
than generally assumed.
Risks in the feasibility study are calculated in accordance with
procedures set forth in the EPA Superfund Public Health
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2-17
Evaluation Manual. The risk model employed uses cancer potency
~alues adopted by the EPA Carcinogenic Assessment Group. The
EPA believes this is a valid procedure for determining risks to
public health from known or suspected carcinogens. .
In addition to the public health evaluation included in the
Times Beach Feasibilitv StudY, EPA has relied on the 1984
Kimbrough assessment, and an additional health assessment
performed by the ATSDR for the Times Beach site in selecting an
appropriate remedy.
The EPA does not believe that environmental risks are over-
. estimated. Times Beach lies in the 25-year floodplain of the
Meramec River. Due to bioaccumulation factors as high as 30,000
reported in the literature, any migration of dioxin-contaminated
soil into the Meramec River could potentially result in dioxin
concentrations of environmental concern in fish and other aquatic
biota. Furthermore, human consumption of these contaminated fish
or other biota could result in a risk to public health.
One commentor stated that it is not appropriate to
clean up sites to a level which corresponds to an
~:~ie::n~::7~ancer risk in the ranqe ot
The Su~erfund Public Health Evaluation Ma~ual states that a. 10-4
to 10-. incremental cancer risk level may be used to determine
the appropriate extent of cleanup at a Superfund site. The EPA
believes that it is appropriate to remediate Superfund sites to
this extent.
One commentor stated that there is no justitication
tor usinq CERCLA tunds tor remediatinq the
uncontaminated structures and debris.
In 1984, a decision was made by EPA to permanently relocate
residents and businesses within the City of Times Beach due to
the discovery of dioxin contamination. This decision resulted in
EPA accepting final management responsibility for the structures
and debris remaining in Times Beach following the permanent
relocation. Final management of this material is justified under
CERCLA on the same basis as the permanent relocation, which is
the threat which existed in 1982 due to the discovery of dioxin
contamination on the roadways of Times Beach. This action will
serve as a completion of the permanent relocation. .
One commentor stated that there is no justification
for further analysis of non-dioxin orqanic
contamination found at the site.
The EPA does not believe that the extent of contamination by
other organics has been adequately characterized. Prior field
investigations have detected the presence of non-dioxin organic
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2-18
contamination in soils in the city park area at depths as great
as 20, feet and in groundwater. Concentrations of other organics
detected range as high as 10 parts per million (ppm) toluene in
groundwater and 7.2 ppm ethylbenzene in soil. The EPA believes
that there is sufficient justification for additional'
investigation of non-dioxin organic contamination at Times Beach.
One commentor stated that it is not appropriate to
consider state and federal water quality criteria
in the selection of a remedy for Times Beach.
The EPA has published a partial listing of potential applicable
or relevant and appropriate requirements which Superfund remedies
must comply with. Federal and state water quality criteria are
included in this listing. The EPA believes that federal and
state water quality criteria are potentially relevant 'and
appropriate, if not applicable to waters of the Meramec River.
SARA requires that remedies at Superfund sites must attain all
identified applicable or relevant and appropriate federal and
state environmental requirements. The EPA believes that federal
and state ambient water quality criteria established under the
Clea~ Water Act and state ,law should be considered in the
selection of a remedy at Times Beach.
One commentor stated that waivers from applicable
or relevant and appropriate environmental
requirements (ARABs' under SARA are not given due
consideration in the Times Beach Peasibility stu~y.
Waivers from ARARs have been considered in the selection of
remedy at Times Beach. A discussion of the potential waivers
considered for remedial alternatives at Times Beach are addressed
in the Proposed Plan. This document has undergone public review
in accordance with CERCLA requirements.
One commentor stated that SPA should treat all of
the dioxin sites in Missouri as a single site for
purpo... of remediation.
The EPA believes that there are efficiencies and economies of
scale to be gained by considering a comprehensive remedy for all
of the dioxin sites located in eastern Missouri. The EPA has
considered establishment of a centralized thermal treatment
facility at Times Beach for treatment of dioxin-contaminated
soils from other eastern Missouri sites. This alternative has
been developed and presented for public comment in the Proposed
Plan, and represents an integrated approach to resolving the
Missouri dioxin situation.
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2-19
One co..entor stated that the risks are too low at
Ti.e. Beach to justify any alternative beyond no
action.
Federal and state health agencies have advised that removal of
soi~s exceeding 20 ppb dioxin is required to redu~e the potential
incremental cancer risk at Times Beach to the 10- level. This
go~l is co~~istent with.the.CERC~ policy of reducing risk to the
10 to 10 range. Th~s r~sk w~llbe further reduced by
placement of a one-foot clean soil layer over all areas at Times
Beach exceeding 1 ppb. The EPA believes that this risk-based
level of cleanup is an appropriate goal for the remediation of
dioxin-contaminated soils at Times Beach.
One commentor stated that the feasibility study
fails to consider the CERCLA statutory preference
tor practicable permanent solutions.
SARA establishes a statutory preference for remedies which
utilize permanent solutions to the maximum extent practicable.
The EPA believes that the thermal treatment alternatives
considered in the feasibility study and in the Proposed Plan.
represent remedies which utilize permanent solutions to the
maximum extent practicable.
. One commentor stated that'an inadequate opportunIty
is provided for public involvement in the remedy
,selection process at Times Beach.'
The statutory requirements for public involvement in the remedy
selection process at Times Beach have been satisfied. The Times
Beach Feasibility Study was released for public comment on
December 29, 1986, beginning a 3-month public comment period
which ended March 27, 1987. A 1-month extension to the public
comment period was granted at the request of this commentor.
An additional one-month public comment period was held for the
Proposed Plan. During this additional public comment period, all
documents contained in the draft administrative record, which
contains all documents forming the basis for remedy selection at
Times Beach, were available for public review and comment. A
responsiveness summary has been prepared 'which addresses all of
the issues raised during the public comment periods. This
responsiveness summary is a component of the Record of Decision
which formally selects the remedy to be implemented at Times
Beach.
One commentor stated that restoration of the site
tor residential use is of questionable legality.
The proposed remedy at Times Beach does not include or allow
return of Times Beach to residential use, although following
remediation some areas of the site will meet the criteria for
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2-20
residential usage. The selection of remedy for the site is based
on protection of public health and the environment under current
and anticipated future exposure scenarios. As stated previously,
the EPA believes it is unlikely that Times Beach will return to
residential land use due to institutional and practical
considerations.
One commentor stated that land use restrictions
exist which would enable potential exposure to
dioxin-contaminated soil at Times Beach to be
limited.
The EPA does not believe that institutional controls of this type
are adequate by themselves to control potential human and
environmental exposure in the future. The EPA does acknowledge
that' institutional controls exist for Times Beach which, in
combination with the remedy proposed, are protective of public
health and the environment. These institutional controls are
discussed in the Proposed Plan.
One commentor stated that the excavation and
storaqe of dioxin-contaminated soil at other
will affect EPA's decisions reqardinq'remedy
selection at Times Beach.
sites
The feasibility study acknowledges the need for management
capacity for dioxin-contaminated soils at other eastern Missouri
dioxin sites. . Due.to the current absence of management capacity
for dioxin-contaminated soils, the remedy selected for Times
Beach will impact other eastern Missouri dioxin sites. The
potential need for cleanup of these other eastern Missouri sites
should not be disregarded in the selection of remedy for Times
Beach. The EPA believes that it is logical and appropriate to
consider a comprehensive remedy for eastern Missouri dioxin
sites. .
,
One commentor states that permanent relocation was
offered to businesses and residences in Times Beach
as a result ot the floodinq and not because of the
dioxin contamination.
The decision by EPA to offer permanent relocation at Times Beach
was related to the discovery, in December 1982, of wide-spread
dioxin contamination within Times Beach. Flooding contributed to
the emergency situation. However, permanent relocation was
offered due to the discovery of hazardous substances at Times
Beach and recommendations by health agencies to prevent continued
exposure from occurring.
One commentor stated that there was an inadequate
opportunity provided for public participation in
the remedy selection process for flood-control
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2-21
..a.ur.. at Times Beach.
The opportunity for public comment on the Spur Levee Project was
provided. The Spur Levee Project was described in the
recommendations and schedule of the Central Storaqe site Pro;ect
Feasibilitv Studv--Missouri Dioxin sites. This study was
released to the public December 7, 1983, and a public meeting to
. present and accept comments on the recommended alternative was
held December 13, 1983. Additional written comments were
accepted through De~e~er 27, 1983. This public comment period
satisfies the statutory public participation requirement for
CERCLA remedial actions.
An environmental assessment was prepared by the u.S. Corps of
Engineers for the Spur Levee project. The public was notified
through local news media of the opportunity to comment on the
environmental assessment prepared for the proposed project and
provided an additional 2-week public comment period prior to
implementation.
DETAILED TECHNICAL COMMENTS ON THE FEASIBILITY STUDY
One commentor offered detailed technical comments on the
feasibility study. These comments. are given below.
Assuminq future residential use [at Times Beach] is
unreasonable.~..the feasibility study's use of a
residential cleanup standard--for a site that is
unlikely ever to be residential aqain--is a serious
conceptual error... .
EPA is not proposing to return Times Beach to residential usage.
Future residential usage was one of three exposure scenarios
considered in the public health evaluation presented in the
feasibility study. Due to the uncertainty in future land use
during preparation of the feasibility study, a range of exposure
scenarios was used including residential, commercial, and
recreational. For the purpose of estimating a contaminated soil
volume, the most conservative future use was assumed. The non-
cost comparison of alternatives for the contaminated soil volume
correspondinq to residential use is valid for a range of soil
volumes, including the current estimate. Cost evaluations were
revised in the Proposed Plan to reflect the current projected
soil volume at Times Beach. EPA believes that these evaluations
represent a valid basis for remedy selection at Times Beach.
Another major flaw in the feasibility study is the
failure to conduct a risk assessment in order to
develop site-specific cleanup objectives....havinq
assumed future residential use, the feasibility
study simply adopts a cleanup standard equal to
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2-22
CCC's qeneric "reasonable level at which to beqin
consideration of action to limit human exposure for
contaainated soil."
During response actions performed at dioxin sites in Missou~i,
EPA has relied upon the recommendations of federal and state
health agencies in determining appropriate cleanup levels. CDC
has recommended that 1 ppb is a reasonable level at which to
express concern for public health in residential settings.
During preparation of the feasibility study, EPA evaluated the
CDC recommendation and determined that 1 ppb was an appropriate
level of concern for evaluation of alternatives. The feasibility
study n~tes, however, that different cleanup levels may be
appropriate for other land uses than that assumed in the study.
...the use of overly conservative factual
assumptions, results in a qross overstatement of
both the hazards of TCDD and the amount of site
cleanup necessary. The use of the hiqhest sinqle
sample value as a basis for planninq site cleanup
results in a distortion of remedial strateqies.
The" public health evaluation was prepared following the
guidelines of the Superfund Public Health Evaluation Manual. As
noted in the manual, "This manual establishes a framework for
public. health evaluation at Superfund sites...." The manual
states explicitiy that a conservative approach may be taken in
making risk estimates. It is clearly stated in the feasibility
: study that this was the approach .taken and the assumptions were
noted.
The risk, assuminq that Times Beach is not
redeveloped for residential use, is truly minimal.
EPA has considered the recommendations of federal and state
health agencies regarding the risks presented by the site. Those
recommendations indicate that the risks posed by the site require
response to protect human health and the environment.
...the aafest, most protective course is to leave
the TCDD in place, with, at most, an appropriate
veqetative cap to prevent soil erosion.
Covering contaminated areas at Times Beach with a vegetated cap
was evaluated in the feasibility study and Proposed Plan. This
~lternative was determined not to achieve CERCLA and NCP remedy
selection criteria to the same extent as the proposed remedy.
The rationale for this determination is described in the Proposed
Plan.
The reason that cappinq does not meet site
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2-23
objective. is...that the site objectives set forth
in the feasibility study are unrealistic.
EPA disagrees that the goals set forth in the feasibility study
are unrealistic. The goals are based on recommendations of
appropriate state and federal health agencies. Remedial
alternatives were developed bas~d on these goals.
...the feasibility study incorrectly views the
procedures for capping and closure under the
Resource Conservation Recovery Act (RCRA) as being
ARARs. In fact, those standards w.re developed for
landfills at which a heterogeneous yet concentrated
assortment of unknown wastes have been buried,...
. .
It is not. EPA's position that landfill closure requirements are
applicable only to landfills containing heterogeneous,
concentrated, and unknown wastes. EPA has determined that
landfill closure regulations are applicable or relevant and
appropriate to some remedial alternatives, as described in the
Proposed Plan.
Even if the RCRA standards are appropriately viewed
as ARARs, the feasibility study improperly fails to
consider whether waivers are appropriate under the
circumstances. .
A discussion of potential waivers from ARAR's for the remedial
alternatives evaluated for Times Beach is presented in the
Proposed Plan.
EPA acknowledges that it is legally required to.
evaluate the "No Action" alternative. Yet its
treatment of this option is purely perfunctory.
EPA disagrees that the treatment of the no action alternative is
perfunctory. The development and analysis of remedial
alternatives is affected by the technical complexity of the
alternatives. The no action alternative is of limited
complexity; therefore, less space is required to develop and
analyze the alternative. In the feasibility study, EPA evaluates
the No Action alternative as seriously as the other alternatives.
certain of the options receiving detailed analysis-
-for example, excavation followed by either offsite
land disposal or offsite incineration--should have
been eliminated from further consideration at the
outset because of their excessive cost and the lack
of permitted facilities.
Offsite land disposal or incineration are considered to be
technically viable options that warrant consideration as remedial
alternatives. Offsite land disposal or treatment capacity could
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2-24
potentially develop prior to remedy selection.
...the feasibility study endorses a samplinq and
excavation approach that is likely to lead to
massive cost overruns. AD alternative strateqy of
extensive initial samplinq, tollowed by sinqle-litt
excavation and limited contirmatory samplinq, would
save substantial amounts ot time and money.
A number of excavation strategies have been evaluated by EPA and
tried in the field. The strategy described in the feasibility
study is similar to ~hat used at other TCDD sites and is
considered to be cost-effective and accomplishes remediation
objectives. Further discussion of this point is provided in
responses to comments regarding final actions at the
Minker/stout/Romaine Creek site.
...steel roll-ott bins, which are expensive to
purchase, handle, and decontaminate, are proposed
tor soil transport. Bulk handling techniques, by
contrast, which have been successtully used by EPA
Reqion VII in southwest Missouri, would be equally
sate and much less costly.
As noted in the feasibility study, the details of material
handling will ,be re-evaluated during the predesign and design of
the selected remedial alternative. Air-tight roll-off bins
provide a high degree of safety during transport, w~ich may be
warranted in densely populated areas.
The use ot relatively small excavation equipment,
such as backhoes, sacritices siqnificant economies
ot scale possible with use ot' larger equipment.
The details of an excavation strategy will be evaluated during
design of the selected remedial alternative. The methods
described in the feasibility study are similar to those
successfully used by EPA during removal activities at similar
TCDD-contaminated sites in Missouri.
The discussion ot worker protective clothing
appears to assume the use ot "moon suits", with the
attendant expense and loss ot worker
productivity....a site-specific risk analysis
should have been performed and would have resulted
in a more rational level of protective clothinq.
It appears that the commentor, in referring to "moon suits," is
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2-25
referring to the use of Levels A or B protective gear. The
feasibility study assumes that Level C gear will be used for soil
handling activities, which is typical of protective gear used for
remediation at other Missouri TCDD sites.
por transportation of soil from offsite, such
extravagantly expensive strateqies as upqradinq of
local roadways, and use of "pilot cars" to
accompany trucks haulinq soil, appear inexplicably
to have received serious consideration.
The details of the selected remedial options will be evaluated
more closely during the design of the option. Upgrading of roads
and use of various control devices will be used as required to
implement the selected remedial alternative and .protect the
safety of workers and the public. .
[Thermal treatment] Technoloqies specifically
designed for low BTU-value soils, and which are
therefore much less costly and more efficient, are
not adequately considered. One very promisinq
technology receivinq scant mention is indirect-
fired thermal treatment with dry pollution control.
This technology is well-developed and has been
tested on TCDD-contaminated soil.
~s noted in the. feasibility study:
"Remedial alternatives evaluated in. this feasibility study are
general approaches to remediation for the site. However,
specific conceptual descriptions are given for each alternative
for purposes of evaluation. Each description is representative
of the alternative and was selected using general rationale given
in the text."
"It is beyond the scope of this study to make a definitive
determination of the precise technologies used for each remedial
alternative. A more definitive analysis of the selected remedial
alternative will be required during predesign of the selected
alternative. It is. likely, therefore, that the final remedial
actions taken at the site will vary somewhat from those described
in the study."
If thermal treatment were selected for site remediation,
technologies such as the ones described by the commentor may be
proposed for use. at the site. Such proposals would be considered
by EPA at that stage in the project.
Dry pollution control techniques would eliminate
the need for wastewater treatment and reduce
contamination of additional material with TCDD,...
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2-26
If thermal treatment were selected as a remedial alternative,
alternate methods of pollution control would be evaluated during
the design phase of the project. Methods of pollution control
different from those described in the feasibility study may be
offered by those proposing to perform the remedial activities.
These alternate methods will be evaluated to ensure that the
selected method meets required performance objectives.
...there is justification neither for extensive
retestinq nor tor Gisposinq of these materials
[uncontaminated structures and debris] other than
in a standard construction/demolition landfill
onsite.
structures and debris at Times Beach must be tested to confirm
that they are not contaminated and can be disposed of as non-
hazardous solid waste. If contamination is detected,
decontamination must be performed prior to disposal in a solid
waste disposal facility, in accordance with permitting
requirements.
There is no apparent reason why an incinerator at
Times Beach could not be appropriately sized to
handle soil from any Missouri TCDD site where a
determination has been made to excavate soil.
During the design phase, performance standards will be prepared
which will require that the thermal treatment unit is capable of
treating a given'volume of contaminated soil in a specified time
frame. Although decisions have not been made to excavate and
treat soils from the additional potential sites identified in the
Proposed Plan, the thermal treatment unit design will allow for
the potential treatment of soils from these sites at Times Beach.
Each site has been treated as a separate problem,
with no attempt to achieve consistency,
coordination, or economies of scale. Such an
approach has been both unnecessary and
unnecessarily costly. Groupinq of related, non-
contiquous sites is expressly permitted under 42
u.s.c. section 9604(d) (4).
Alternatives evaluated in the Proposed Plan include potential
responses at all identified eastern Missouri dioxin sites. It is
not appropriate to evaluate remedial'alternatives for Times Beach
and the Kinker/Stout/Roman Creek site in isolation. The cost
effectiveness of the
Minker/Stout/Romaine
consideration of the
related sites. This
remedy for Times Beach and the
Creek site must be evaluated in
potential need for response at other nearby
evaluation is performed in the Proposed
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2-27
Plan.
Risk Asses..ent
The us. of the sinqle hiqhest value for TCDD soil
contamination, without qivinq due weiqht to the
results of more than 500 other soil samples which
reflect an averaqe TCDD concentration of less than
2.5 ppb, is a totally inappropriate and unrealistic
approach....it would be much more appropriate to
us. a TCDD soil concentration value of 2.5 ppb
rather than 1200 ppb in the risk analysis.
The use of a maximum is compatible with the methods outlined in
.the Superfund Public Health Evaluation Manual and represents a
conservative estimate of risk. This was carefully noted in the
feasibility study.
Because the feasibility study erroneously considers
Times Beach a residential site, it has qreatly
overestimated the contribution of soil inqestion to
the lifetime averaqe daily dose of TCDD. soil
inqestion will not be a significant exposure
pathway at a non-residential Times Beach.
A cleanup level of 20 .ppb has been established for Times Beach
which is appropriate for non-residential exposure. This cleanup
level is based on recommendations from federal and state health
agencies, as discussed in the Proposed Plan, and considers
limited ingestion in non-residential areas.
Based upon the CDC approach and CDC assumptions
relatinq to TCDD risk to human health, the Level of
Concern for TCDD at a non-residential site is 20
ppb.
A cleanup level of 20 'ppb has been,established at Times Beach.
...animals at Times Beach would not consume
sufficient soil to produce adverse effects.
Elevated levels of dioxin have been detected in wildlife at the
site. Due partially to potential bioaccumulation in wildlife, a
one clean foot soil layer of clean soil is. a component of the
selected remedy at Times Beach.
Executive Summary
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2-28
The definition of a cost-effective alternative
referred to in the Executive Summary of the
feasibility study appears to be the one used in the
National oil and Hazard Substances Contingency Plan
(NCP) of 1983 rather than that which appears in the
1985 revision.
This discrepancy has been corrected in the Proposed Plan and.ROD.
...a primary incentive for the. EPA buyout of Times
Beach vas related to the need for a permanent
solution to the routine flooding of the toVD. In
short, the primary purpose of the buyout was to
improve the social good, not to protect inhabitants
from the TCDD hazard.
Many cities and towns are routinely flooded but are not bought
out by the federal government. The buyout, as noted by reference
material included by the commentor, was initiated when CDC
recommended that residential exposure to soils containing TCDD
exceeding 1 ppb represented a level of concern, which was the
case at Times Beach.
...these figures for the various soil
several times greater than the amount
. excess of 1 ppb which actually exists
. . Beach,. . . .' . .
volumes are
of soil in
in Times
The volumes of soil presented in the feasibility study are
remediation volumes estimated from available sampling data and
assumptions regarding the extent of excavation that would be
required. It is expected that the final excavated volume will
differ from the estimates presented in the feasibility study.
The (risk) estimates are likely to overestimate
the actual risks by a factor between 500 and 5,000.
As noted in the feasibility' study, the estimates of risk are
considered to be conservative estimates calculated in accordance
with EPA policy guidance.
...the sampling was biased upwards because it
focused on areas of suspected contamination.
This is a primary reason that existing sampling data could not be
used to develop an average concentration for risk evaluation
purposes. EPA's sampling strategy is to define the source of
contamination, in this case the roadways, and expand the sampling
perimeter from the source until the areal extent of contamination
is defined.
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2-29
Tbe f.asi~ility study sbould contain an evaluation
of tb. potential health risks associated with
variou8 l.vels of TCDD contamination of the soil.
EPA has relied upon recommendations of federal and state health
agencies in determining the health risks posed by various levels
of TCDD contamination. For the case of Times Beach these health
agencies have recommended appropriate cleanup levels for
different land uses.
Although the use of the single highest groundwater
sample may ~e appropriate for estimating ultimate
exposure to the community, this approach was not
intended, nor can it be justified, for application
to the risk assessment of contaminated soil.
This comment has been responded to previously.
...the superfund Risk Assessment quidelines were
not intended for contaminated soil.
The Superfund Public Health Evaluation Manual (EPA, 1986) is
clearly intended to be used for soil as well as other release
mediums. For example, pages 41 to 46 of the manual,. which
describe procedures for identifying release sources and media,
identify soil as w~ll as air, surface water, ~nd groundwater as
sources to be evaluated.
...the relatively few high values of TCDD detected
in Times Beach were obtained primarily from beneath
paved roads where human exposure is virtually
impossi~le.
The roadways throughout Times Beach generally consist of
deteriorating macadam which can not be expected to provide ,an
effective long-term barrier against exposure. The dioxin level
used for the risk assessment resulted from analysis of a soil
sample collected at'Times Beach in a non-paved area.
A central pro~lem with the current feasi~ility
study is that much of the discussion is predicated
upon. 1 ppb level of concern for a residential
site, wbich is not one of the settings considered
in tb. public healtb assessment.
The public health assessment in the feasibility study did
consider a future residential setting. Furthermore, the risks
posed by exposure to soils containing TCDD in excess of 1 ppb in
a residential setting have been estimated by the CDC. The
increased_gancer :~sks due to such an exposure were estimated to
exceed 10 to 10 .
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2-30
The fe..ibility study properly recognizes that it
is co.pletely inappropriate to return Times Beach
to reoidential use. Nonetheless, the feasibility
study proceeds to treat Times Beach as a
residf:ntial site.
The feasibility study does not claim that it is "completely
inappropriate" to return Times B~ach to.residential use. It is
noted that such a use is possible, although not likely.
...soil levels of TCDD in excess of 40 ppb for
residential areas and soil levels in excess of 120
ppb in non-residential areas should be acceptable.
EPA has relied upon recommendations of federal and state health
agencies to determine an appropriate cleanup level. The levels
noted by the commentor exceed the level of concern recommended by
these health agencies. .
Any risk assessment procedure that would suqqest
that 3 of every 10 persons who occasionally visits
Times Beach will develop cancer as a result of .
exposure must be qrossly overestimated.......it is
particularly troublesome that such risks would be
identified for this settinq in view of the ample
evidence indicatinq that, until exposures are
sufficient to produce chloracne, not only would an
increase in cancer not be expected, but also no
other adverse health effects would be anticipated.
The risk estimates developed in the feasibility study are
conservative estimates, as noted previou.sly and in the
feasibility study. The estimates are based on the specific
assumptions noted in the text.
Times Beach should not be restored to residential
use.
EPA is not proposinq to restore Times Beach to residential usage.
The Agency's preferred alternative is described in the Proposed
Plan.
It would be useful for the report to put this level
of increased risk into perspective.
...if a 1 ppb clean-up level is implemented, the
necessary deqree of clean-up is overestimated by at
least a factor of 50 to 100-fold.
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2-31
As noted previously, EPA has relied upon.recommendations of
federal and state health agencies in determining the degree of
remediation that is required.
section 2--BackQround
The first sentence should be revised to read,
"Times Beach is in southwest st. Louis County,
approximately 2J ~iles southwest of the City of st.
Louis..."
The statement made in the feasibility study is correct. The
distance from Times Beach to st. Louis will depend upon the
points of measurement, so different distances are.possible.
The first sentence should be revised to read,...
.It is believed that the TCDD may have been
qenerated at the NEPACCO chemical plant in Verona,
Missouri."
The sentence is correct as presented in the feasibility study.
...samplinq exercises are siqnificantly biased
because samplinq efforts have focused on suspected
hotspots with minimal emphasis on assessinq the
most representative level of actual. contamination
at the site.
EPA agrees that the original sampling was targeted to the most
likely areas of contamination. This samplinq program is cost-
effective and suitable for feasibility study analysis. It is
expected that additional sampling and analyses will be required
prior to site remediation. .
Replace the first paraqraph with the followinq:
...A number of the streets in the 1 to 5 ppb ranqe
were Dot sprayed directly; contamination in these
cases is the result of vehicular trackinq."
Some contaminated streets may not have been sprayed directly.
is not possible, on the basis of records or available data, to
determine precisely which streets were originally sprayed with
contaminated waste oil. Many of the streets may have become
contaminated as a result of vehicular traffic.
It
Vertical miqration would not be expected in areas
other than those directly sprayed with waste oil.
The available data and characteristics of dioxin suggest that
vertical migration potential is less in non-sprayed areas than in
sprayed areas.
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2-32
The fact that only 3 of 26 yard samples yield
detectable levels confirms the fact that
contaaination is not widespread and is confined to
roadways and surface drainaqe ways.
The Proposed Plan notes that the available data indicates that
contamination is generally limited to roadways throughout Times
Beach.
...volume estimates correspond to "loose" volumes
rather than "bank" volumes. consequently, the
volumes cited are not true remediation volumes.
. .
The volume estimates in. the feasibility study are "loose"
volumes. Since the volume estimates are relevant primarily to
the alternatives that involve removal, the loose volumes
represent the volumes of material that would require handling.
In many cases, the surface concentration (which
governs risk) ~as less than that detected at 6 inch
depth. .
Surface concentrations of dioxin have been determined using a
statistically based sampling protocol which determines average
concentrations within individual portions of the site to the 95%
upper confidence level. This sampling has defin~d areas within
Times' Beach requiring response.
'Section 3--Summarv of Public Health and Environmental Assessment
"For the future settings it is assumed that site
access would not be restricted and land use in the
vicinity of the site would differ from current land
use. II This statement is inconsistent with the
feasibility study Introduction and Executive
Summary, . . .
This analysis was included in the baseline public health
evaluation to determine present risk under a number of potential
exposure scenarios. .
The feasibility study should indicate the criteria
by which these 12 contaminants (other organics)
were identified.
The criteria used to identify the 12 other organic contaminants
is described in Appendix B to the feasibility study.
Althouqh Appendix B does contain some discussion of
these (other orqanic) chemicals, it is not
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2-33
adequately detailed.
EPA considers the discussion of other organic contaminants to be
adequately detailed. The focus of the feasibility study was
remediation of structures and debris and dioxin-contaminated
soils at Times Beach. The Proposed Plan states that an
. additional evaluation will be performed to characterize and.
evaluate other non-dioxin contamination.
...it is an overstatement to claim that several of
the other organic chemicals are probable
carcinogens.
.
Among the other organic chemicals, trichloroethylene and bis(2-
ethylhexyl) phtha~ate are classified by the E~A Carcinogen
Assessment Group as probable carcinogens, and 1,1,2,2-
tetrachloroethane is classified as a possible carcinogen. The
listing of bis(2-ethylhexyl) phthalate as a probable human
carcinogen was made after the feasibility study was released.
It is not justified to refer to those persons that
live within a half mile of Times Beach as "local
re.,idents"...
It was stated explicitly in the feasibility study that there are
no people living at Times Beach. The feasibility study defines
local residents as those living within a half-mile radius of .
Times Beach. .
...returning Times Beach to residential use would
be unlawful under CERCLA. It is inconsistent with
this statutory scheme for EPA first to relocate a
community permanently and then to perform further
remedial action to return the site to residential
use. There is no provision of CERCLA authorizing
EPA to enter into a land development business, in
which community residents are evicted and other
individuals are recruited to reside in a community
atter it is restored.
While it is not unlawful under CERCLA to return Times Beach to
residential use, as discussed in the Proposed Plan, EPA is not
proposing to return Times Beach to residential usage. Certain
non-residential uses of the site will be possible following site
remediation. Title to the site following the cleanup will be
held by the state of Missouri. Through this mechanism, and the
Missouri Registry of Abandoned or Uncontrolled Hazardous Waste
Sites, the state will have control over future land use at Times
Beach. It is possible that local zoning ordinances may be
instituted which also control future land use at Times Beach.
...even it crops were grown on the site, scientific
data exist that plants, in general, do not take up
TCDD from the soil. Moreover, the TCDD exposure to
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2-34
agricultural workers would be de minimus, in
contra.t to the claims in the feasibility study.
As noted in the feasibility study, there is conflicting evidence
regarding the uptake of TCDD by plants. Estimates of plant
uptake on TCDD concentration were not used to estimate risks to
agricultural workers. The primary routes of exposure for
agricultural workers were assumed to be dust inhalation and
hand-to-mouth ingestion of contaminated soil.
...these risk ranges are not taken from the
SUDerfund Public Health Evaluation Manual (EPA,
1985) as implied by these statements. If there is
a source or a published policy position that
mandates that risk be kept within.this range, it
should be cited.
As noted on page 118 of the Superfund Public Health Evaluation
Manual (EPA, 1986): "According to Agency policy, the targent
total individual carcinogenic risk resulting from eXP9sures at a
Superfund site may range anywhere between 10- to 10- ."
...these represent only draft guidelines and were
primarily intended to be applied where populations
exposed to this degree of risk were in excess of
10,000 persons.
As noted on page 1 of the Superfund Public Health Evaluation
Manual (EPA, 1986)~
"This manual establishes a framework for public health evaluation
at Superfund sites and for development of health-based
performance goals for remedial alternatives that. are based on
applicable or relevant and appropriate requirements of other
laws, where available, or risk analysis techniques where those
requirements are not available.
There are no limitations noted in the manual on the populations
exposed.
It is unclear how some of the values for excess
cancer risk in Table 3-3 were calculated.
The methodology used to estimate excess cancer risk is detailed
in Attachment B-1 to the risk assessment included as Appendix B.
While the .airborne dust concentration of 76 mg/m3
may be reasonable for total suspended particulates
(TSP), much of the TSP is not respirable due to
their large size.
It is agreed that not all of the airborne dust would be
respirable. However, a specific size distribution for
particulates at Times Beach is not available.. Generally, 25 to
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2-35
90 percent of airborne dust is respirable. It was conservatively
estimated in the feasibility study that 100 percent of the
airborne dust would be respirable. It is likely that the actual
respirable function would be less than assumed.
Further, not all airborne dust arises trom soil or
crustal material.
It is true that not all dust is of a soil or crustal origin.
However, at Times Beach it is unlikely that vehicle or industrial
emissions would be significant contributors to airborne dust.
The most likely source at the site would be soil or crustal
material at the site.
It is highly unlikely that ~here vill be security
quards patrolling Times Beach 8 hours per day for
40 years.
Times Beach is currently patrolled by security guards hourly, 24
hours per day. It is anticipated that this practice will
continue until cleanup of the site has been completed. It is
therefore not unreasonable to assume that security guards will
remain onsite. The length of time until cleanup is completed is
dependent upon remedy selection. .
While the traction ot inhaled dust that reaches
the gastrointestinal tract is 0.625, only Abou~ 30%
ot vhat gets there is absorbed. It a
gastrointestinal bioavailability of 30% is taken
into account and the adult body weight ot 80 Kg is
used (Diem and Lentner, 1973), then the cancer risk
decreases further to 1.8 X 10-8.
Bioavailability of dioxin in Missouri soils has been determined
to be higher than 30%. Bioavailability factors of dioxin in
Missouri soil as high as 60 - 70% have been reported in the
literature. .
...the exposure ot such
similar to the security
calculated on the basis
assumptions.
workers to airborne dust is
guard and is here
ot unreasonable
Issues regarding airborne dust have been previously addressed.
...the mean contaminant concentration of other
organic contaminants should be at least 10-fold
lover than the maximum contaminant concentration.
Although EPA agrees that the mean concentration will be lower
than the maximum, it is not possible to accurately predict mean
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2-36
concentration on the basis of the maximum. Upper bound estimates
of risk are presented in the feasibility study. It is also
possible that subsequent sampling will detect higher maximum
concen~rations.
The amount of soil ass\tmed to be ingested is also
unrealistic. The figure of 50 or 100 mg of soil
ingested per day used in the feasibility study are
on the high range of what has been used by other
risk assessme~ts.
Based on a review of the literature, 50 to 100 mg per day of soil
ingested is a reasonable estimate for soil ingestion.
. .
It is also unlikely that an individual would ingest
100 mg of dirt per day during the entire 185 day
growing season. only on tilling days could dirt
. ingestion approach 100 mg/day.
A range of 50 to 100 mg of soil ingested per.day was used in the
feasibility study. The range used is appropriate for this
activity.
...the adult body weight is closer to 80 kg than 70
kg.
As noted later by the commentor, 80 kg is the average body weight
for adult males. Since the expopure could occur for both males
and females, an average body weight that considers both sexes
would be appropriate. The average adult body weight is closer to
70 kg (i55 lb) than 80 kg (170 lb) .
section 4--screeninq of Alternatives
The general discussion at pages 4-1 to 4-3 does not
reflect more recent EPA final guidance such as the
EPA "Interim Guidance on Superfund selection of
Remedy," Dec. 24, 1986, reorinted in [Current
Developments] 17 Env't Rep. (BNA) 1603-7 (Jan. 16,
1987) or BPA draft guidance developed subsequent to
enacta8nt of the Superfund Amendments and
Reauthorization Act of 1986, ("SARA") P.L. 99-499,
100 stat. 1613 (1986), ~, "Superfund Selection
of Remedy Strategies and options," November 12,
1986; "Superfund Selection of Remedy: Draft NCP
Language (RI/FS section)," February 26, 1987.
The feasibility study, which was released for public
December 18, 1986, can not reflect guidance that was
subsequent to its release. The feasibility study is
to be compatible with the requirements of SARA.
comment on
published
considered
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2-37
...BPA states that the state of Missouri has not
designated a final use for ~imes Beach. It is
loqically impossible to generate a feasibility
study without such a determination.
Risks were evaluated for a range of potential future land uses.
Federal and state health agencies have recommended appropriate
cleanup levels for different future. uses. This information
allows a valid risk-based remedy selection to be performed. The
revised cost and non-cost evaluation of alternatives passing
final screening is presented in the Proposed Plan.
Ac'cordinq to the feasibil.! ty study, a vi tal concern
for a "No Action" alternative is wind erosion of
TCDD contaminated soil. This is not, in fact, a
concern with enhanced vegetation or the current
state of vegetation at the site.
Wind erosion of contaminated soil is a concern at the site.
contaminated surfaces are not stabilized by vegetation or
pavement.
...the non-residential remedlation Level of Concern
should be applied to a site which experiences
reqular and frequent floodinq damaqe.
All
EPA is not proposing to restore Times Beach to residential usage.
The cleanup level established for Times Beach corresponds to non-
residential usage.
In many cases the "Typical Technoloqies" column
does not list all appropriate technoloqies.
Typical technologies are intended to be representative examples.
The list of technologies was not intended to be inclusive.
The use of posted fencing would be the most cost
effective means of security at the site and would
allow the elimination of 24 hour quard service.
Posting of the site would not provide adequate security. Site
intruders are frequently apprehended by security guards during
patrols. All roadways leading to Times Beach are currently
barricaded and posted with appropriate signs.
Sedimentation basins, combined with a site
perimeter fence, represent a more conservative
method of meeting the general objectives than the
"No Action" response.
Sedimentation basins and perimeter fencing do represent a more
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2-38
conservative remedy than "no action".
...the use ot appropriately sized and selected
excavation equipment, combined with bulk handling
techniques, bulk storage, and on-site disposal or
treataent will provide substantial savings over
conducting an excavation program using undersized,
poorly selected excavation equipment, containerized
handling and temporary storage prior to disposal or
treatment. Enormous cost savings can be realized
by the dramatic reduction in labor and the
elimination ot the following: multiple handling of
the excavated materials; container purchase,
handling and disposal costs; temporary storage
c~sts; transportation costs; .handling at the
disposal or treatment area and the huge cost of
disposal or treatment.
The techniques described in the feasibility study are typical of
those used with success by EPA in various removal efforts in
Missouri. The details of the excavation and handling strategy
will b~ further evaluated.in the predesign and design phases of
the project... .
...the only known treatment technoloqy which is
currently av~ilable and which consist~ntly provid~s
destruction efficiencies that meet regulatory
requirements is thermal treatment.
This statement is consistent with the feasibility study and
Proposed Plan.
The most cost effective means of thermal treatment
of TCDD-contaminated soil is through use of
indirect-fired incineration combined with dry
pollution control.
Rotary kiln incineration was used as an example of thermal
treatment technologies in the feasibility study. Any thermal
treatment technology capable of meeting the performance standards
will be considered.
Costs ot treatment using indirect-fired technoloqy
are in the range $150-$250 per ton of soil
processed.
Alternative thermal treatment technologies may be proposed during
th~ bidding phase of the project and will be evaluated at that
time. If indirect-fired is cost effective, one or more proposals
incorporating this technology would be expected.
other treatment technologies are experimental in
their level of development, create environmental
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2-39
pro~l..s greater than those they solve, are
eztraaely costly, or do not attain desired
destruction objectives.
This statement is consistent with the feasibility study and
Proposed Plan.
A method which is not mentioned in the feasibility
stUdy that may provide consider~le promise for in
situ treatment of TCDD-contaminated soils is
"enhanced in situ photolysis."
It is doubtful that the technology would achieve the site-
specific objectives required at the site. This process was
evaluated and screened during the feasibility study process.
Photodegradation has not resulted in significant reductions in
surface concentrations at Missouri dioxin sites investigated.
Temporary storage of contaminated materials should
be eliminated as an option...
The specific material handling details of the selected
alternative will be developed during the predesign and design
phases of the project. Temporary storage will be used if it is
considered to be cost-effective and necessary to ensure that
performance objectives are met, including protection of human
health and the environment.
If "Disposal" were selected, the excavated soil
should be hauled directly to the disposal site
without interim storage.
The specific material handling details of the selected
alternative will be developed during the predesign and design
phases of the. project. Temporary storage will be used if it is
considered to be cost-effective and necessary to ensure that
performance objectives are met.
If "Treatment" is selected, only that amount of
soil required to provide feed stock to the
treatment system should be temporarily stored on
site, not to exceed one month's capacity of the
treatment system.
The amount of soil stored would be sufficient to permit cost-
effective operation of the treatment system. If capacity is
excess of one month capacity was required, that quantity would be
stored. The specific details of soil staging requirements would
be considered further during design of the facility.
storage of TCDD contaminated soil is very
straightforward and does not require rigorous
facility design due to its very insoluble and non-
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2-40
volatile nature.
The design of any storage facility would be sufficient to protect
the health of workers and the public during remedial operations.
The specific details of any storage facility would be developed
during the design of the facility.
The storage facility should be designed to prevent
run-off containing contaminated sediment from
reaching an uncontaminated area.
The remedial design will incorporate appropriate measures so that
contaminant migration is minimized.
If thermal treatment were selected, precautions
should be taken to cover the storage area to
prevent excessive wetting of the soil due to
rainfall, thus reducing the water evaporation load
to the thermal treatment system, thereby reducing
fuel consumption.
The remedial design will incorporate appropriate measures to
ensure that soil moisture of the staged material is controlled.
TCDD-contaminated soil should not be excavated for
the sole purpose of depositing it in another
disposal location because the inberent physical
properties o.f TCDD-contaminated soil make it such a
low risk to the environment and general population.
The issues involved in disposal of TCDD-contaminated soil are
discussed in the feasibility study. The remedial alternative
selected by EPA is described in the Proposed Plan, and does not
involve land disposal of dioxin-contaminated soil.
A safe disposal area need only prevent exposure by
contact, eliminate erosion of the soil and prevent
dust-borne migration of the contaminated material.
This can be accomplished by construction of a
monofill using contaminated soil, covering the fill
with clean soil, and planting a vegetative covering
over the clean soil.
A number of options for disposal, including construction of a
monofill, are discussed in the feasibility study. The
feasibility study does not rule out a monofill as a storage
option. If land disposal were selected, the details of the
storage facility would be evaluated during design and predesign
of the facility.
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2-41
...no leachate collection is required since water
miqratinq throuqh the fill would not contain any
contaminants.
Leachate from a disposal facility would likely contain TCDD-
contaminated particles that would require separation prior to
disposal of the leachate. I~ addition, since there is a
possibility for a breach of the liners, a collection system would
be required.
...there is no justification for flood control
related to TCDD remediation. No evidence to date
suqqests that TCDD is miqratinq or leavinq the site
due to floodinq.
Flood control would be required to protect equipment or workers
located onsite during implementation. Flood protection is
required for some alternatives in order to comply with all ARARs.
This is further discussed in the Proposed Plan and Record of
Decision.
The "No Action" remedial alternative should be' as
fully explored as all of the other alternatives,
especially because it represents an alternative
which is scientifically, technically and
economically viable.
As noted previously, EPA believes that.the nO.action alternative
undergoes the same degree of evaluation as other alternatives in
the Feasibility study.
...an impermeable barrier is not required to.
stabilize and prevent the miqration of TCDD
contaminated soi1.
Several options for capping are discussed, both permeable and
impermeable. Although one option is described in detail, the
Feasibility Study does not rule out the possibility that other
options would be considered if capping were selected for the
site. The specific methods would be evaluated in greater detail
during predesign and design of the project.
It is unclear whether the existinq site security
will remain in effect under this (the no action)
option.
The no action alternative is a remedial alternative that assumes
that no additional emergency or remedial actions are taken at the
site. For the feasibility study, it is generally assumed that
security guards would remain, although risk estimates are
performed that evaluate exposure potential in the case that the
guards are removed.
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2-42
The risk to an unauthorized intruder is neqliqible
and doe. not merit the expense of full time
security personnel.
Security guards are necessary not only to protect the health and
safety of intruders, but to assure no contaminated soil
disturbance and/or offsite transport occurs.
The only response action which would require a
level of flood protection is on-site treatment. No
other on-site disposal option, or other response
action, would justify the expense of flood control
measures.
The requirements for flood protection will be evaluated for the
selected remedial alternative during the predesign and design
phases for the alternatives. It is possible that options, other
than onsite treatment, may require flood protection.
...if treatment of these vaters is mandated by EPA,
only filtration should be used to remove the TCDD
contaminated soil particles. Any other types of
treatment, includinq use of activated carbon or
activated sludqe, are not merited due to TCDD's
dramatic lack of water solubility~
The specific water treatment method selected will be evaluated.
during the predesign'and design phases of the project and would
be adjusted as required during the project. It is expected at
this time that carbon adsorption treatment would be used during
site activities for filtration and removal of organics.
. ...if "In-Place containment" were selected by EPA
as a remedial response action, a soil and
veqetative cap is the only technoloqy that should
be considered appropriate for the TCDD-contaminated
soil. Impermeable or low permeability cappinq
techniques are not required for prevention of
exposure, dustinq and erosion of TCDD contaminated
soil which is a hiqhly insoluble and non-volatile
material.
If in-place containment were selected, the specific features of
the cap would be evaluated and developed during the predesign and
design phases of the project.
...the presence of a clay or impermeable barrier
under a final soil and veqetative cover increases
the likelihood of erosion of the final cover and
qreatly complicates the establishment and qrowth of
the veqetation. since percolation of water throuqh
the cap will not cause leachinq of the TCDD into
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2-4.3
. .
the groundwater, the additional, conservative,
measure of installing an impermeable barrier is not
justified and is actually detrimental to a lasting
and aesthetically pleasing grass cover at the site.
If in-place containment were selected, the specific features of
the cap would be evaluated and developed during the predesign and
design phases of the project. The Proposed Plan evaluates
placement of a synthetic membrane beneath the vegetated soil
cover. .
.11>
Expensive sodding or erosion control mats are not
justified in preference to conventional grass
seeding .operations since there has been no release
of contaminated soils to date. .
The method used to establish vegetation on exposed soil would be
evaluated during the design phase and selected according to the
requirements of the remedy. The remedy must be cost-effective in
addition to providing protection of human health and the
envb onment.
only direct treatment via thermal processing is
capable of meeting desired target goals while
providing a relatively low unit cost of treatment.
Thermal treatment is the only treatment method that has been
demonstrated to consistently meet goals for destruction of TCDD.
Indirect fired rotary kiln thermal treatment
combined with dry pollution control devices will
produce the most reliable and least costly.
treatment response in terms of labor and energy
consumption.
This and other methods of thermal treatment would be evaluated
during the predesign and design phases of the project. If
proposed by those offering thermal treatment services during the
bidding phase of the project, the technology would receive
consideration at that phase of the project.
At this point in the feasibility study, one should
have a fairly accurate accounting of what hazardous
substances are to be encountered and at what
concentrations.
Sampling at the site to date has been concentrated in the most
likely areas of contamination. The sampling is considered to be
sufficient to support feasibility study analysis, but additional
sampling and analysis will be required during remediation
activities onsite.
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2-44
Direc~ con~ac~ of the existinq TCDD con~amina~ion
is unlikely due to its loca~ion qenerally benea~h
paved or composi~ion roads.
Although some of the TCDD is located beneath road surfaces,
contamination has been detected in other areas with no cover or
stabilization. . .
cappinq with an adequate veqeta~ive cover can be
considered a flood or erosion control measure.
..
Capping could represent an erosion control measure. Since a cap
would not prevent or slow the movement of floodwaters at the
site~ it is not considered to be a flood control measure.
...cappinq "will" and not "may" reduce the
potential for miqration and contact.
The performance of a response action will depend, in part, on the
specific features of the action and maintenance activities that
are required. .
"The TCDD concentrations must be reduced to below
less than 1 ppb to meet the site objectives." The
ash or treated soil will more than like1y be
landfilled at the site and below the surface.
Therefore, if the depth is sufficient, hiqher
concentrations of residual TCDD may be allowable.
Final disposal of treatment residue will be controlled by state-
issued permit conditions. The residue must successfully pass a
delisting petition in order to be disposed of as non-hazardous
solid waste. A plan for disposal will be developed during the
design phase for the project.
...technology considerations for physical/chemical
treatment and bioloqical treatment refer to the
thermal treatment of soil which is inappropriate
for these two types of technologies.
This error in the feasibility study has been noted.
It is inappropriate to state an absolute
requirement that a technology must achieve a 1 ppb
average concentration. If the technology achieves
siqnificant results and has favorable economics, it
may be viable and desirable to pursue to reduce the
risks to public health and the environment.
The selected technology must meet the performance objectives
are required for the site which will include delisting of
treatment residue and compliance with any required permit
conditions. .
that
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2-45
...further technoloqies may be developed, and
should not therefore ,be omitted based strictly on
an arbitrary selection of a Level of Concern. The
feasibility study approach is not consistent with
the HCP requirement that alternatives must be
considered which "do not attain applicable or
relevant and appropriate public health or
environmental standards, but which will reduce the
likelihood or present any further threat from the
hazardous substances and that will provide
significant protection to the public health and
welfare and environment."
. .
The feasibility study is consistent with the NCP. All potential
remedies under CERCLA~ as amended, must be protective of human
health and the environment. Those alternatives determined not to
achieve protectiveness can appropriately be eliminated from
further consideration.
There is no description of what relevant and
appropriate federal public health or environmental
requirements must be met by a cap, and why they are
not satisfied.
The feasibility study specifically notes on pages 7-39 and 7-51
the requirements that should be considered. The landfill
standards at 40 CFR 265, Subpart N (Landfills), are cited as well
as the closu~e standard at 40 CFR 265.310. A further discussion"
of ARARs is presented in the Proposed Plan. .
"Unknown quantity ot hazardous substances" under
the headinq "Waste Characteristics." Rarely will a
site be as well de tined as Times Beach in terms ot
the hazardous waste constituents and concentration.
The level ot data available tor evaluation can
hardly be termed "Unknown."
The precise volume of soil requiring remediation will not be
known until completion of the cleanup. The available data allow
a reasonably accurate projection of volume, but there is
uncertainty due to the non-uniformity of the contamination and
procedures used to remove contaminated soil.
The commentor stronqly aqrees that the technoloqies
of "Cappinq" and "Enhanced Veqetation" should be
retained tor consideration and that the remaininq
methods should no lonqer be considered appropriate.
Placement of a vegetated cap over contaminated areas at Times
Beach was further evaluated in the Proposed Plan.
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2-46
...onlyon-site (as opposed to off-site) disposal
or treatment should be considered. Off-site
disposal or treatment would require lenqthy and
unnecessary transportation, temporary storaqe and
other related expenses.
EPA is proposing an onsite remedy for contaminated soils at Times
Beach. Offsite disposal or treatment are considered to be
technically viable options that merit consideration in the
feasibili ty study. T.le fact that some alternatives require
different transportation or handling expenses than other
alternatives does not warrant their elimination from detailed
analysis.
....the "Limited' Action" and "In-Place Containment"
remedial alternatives cited in Table 4-8 should be
described under column "NCP Guidance Alternative
.cateqory" as "Alternative that attains or exceeds
applicable or relevant and appropriate federal
public health or environmental requirements."
Limited Action and In-Place containment alternatives do not
necessarily attain all ARARs, and it is not appropriate to
designate them as such.
. A c~p desiqned to address dioxin conta&inated soil
should have A two-fold qoal of preventing physic~l
contact with the contaminated soil and the.
'prevention of erosion of .that soil.
This point is consistent with the feasibility study.
cappinq is a conservative and scientifically
defensible remediation technique.
The usefulness of capping as a remediation technique depends
highly on the material being capped, the site where capping is
taking place, the type of cap that is installed, and the
maintenance that is performed subsequent to installation of the
cap. Alternatives involving capping are evaluated in the
feasibility study and Proposed Plan.
...water percolation throuqh the cap is acceptable
and the cap should provide a physical barrier
rather than a hydraulic barrier.
Specific features of the design of a cap would be considered
during design of the remedial alternative.
Several comments were made reqardinq cap location,
desiqn and monitorinq.
As noted previously, the details of a cap, if selected as a
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2-47
remedial alternative, wo~ld be worked out during the design and
predesign phases of the project. Issues raised by the commentor
would be considered at that time. '
sites should be remediated in the most efficient
and cost effective sequence.
Cost-effectiveness is a requirement for all remedies under
CERCLA. There are other requirements that must be met for site
remediation including protection of public health and the
environment, compliance with ARARs, and use of treatment
technologies that result in a reduction in toxicity, mobility, or
volume of hazardous substances to the maximum extent practicable.
Sampling should be conducted at the onset of the
project to facilitate design of the excavation.
Subsequent sampling has been performed utili~ing the 95% Upper
Confidence Level protocol to more accurately define the extent of
contamination. . This has enabled more accurate projections of
contaminated soil volumes to be made prior to remedy selection.
Additional sampling will be performed, as required, to fully
, define the areal extent of contamination prior to soil removal.
Th. primary function of the sampling should be to
define the lateral limit of the target surface
contaminant concentration. A secondary' function of
the sampling should ,be to validate or adjust the
design depth of excavation ~geDerally one foot in
contaminant source areas and six inches in
contaminant dispersal \areas).
i
The primary purpose of soil sampling at Times Beach has been to
define the areal extent of contamination. More labor-intensive
and costly sampling procedures are required to determine the
vertical extent of contamination.
...depth sampling should consist of incremental
samples to verify the depth of excavation necessary
to accommodate the target subsurface contaminant
concentration.
EPA has determined that it is more cost-effective to remove soil
in successive lifts followed by additional sampling to determine
residual contaminant levels, than to attempt to define the
vertical extent prior to excavation. The thickness of the
initial lift of soil removed is adjusted according to the
contaminant level detected at the surface.
Equipment which may be utilized includes backhoes,
motor graders, wheel loaders, belt loaders,
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2-48
scrapers, protilers and vacuums. Each has distinct
capabilities... Hinimal hand excavation should be
anticipated.
The specific techniques required for excavation will be
established during the.design and Planning phases of the project.
: ..excavation should proceed to the tull depth ot
contamination in an uninterrupted series ot litts.
Excavation should commence at the upgradient
(hydraulic) end ot the site and progress generally
as a single working tace. Haterial should be
removed in discrete litts, rather than a single cut
to total depth, to preclude the possibility ot
cross contamination.
It is not Possible to determine the precise vertical extent of
contamination in a cost-effective manner which would assure
confidence that cleanup levels are achieved following excavation
to a pre-determined depth. Excavation of the site will proceed
from Upgradient to downgradient areas. . Removal of soil in
mul~lp'e lifts minimizes cross contamination due to spillage.
Backtill operations should parallel, and Closely
tollow, the exc~vation operations. No daily cover
ot excavated are&s should be required.
A temporary cover is.required prior to backfilling to prevent the
spreading of contaminated soil while awaiting sample results
which will determine if additional excavation is required.
Backfilling follows excavation when it is established that
cleanup objectives have been met.
backtill procedures are unnecessary.
Backfilling is necessary to safely close the site and establish
drainage.
Backfill material should be obtained trom borrow
pits to be developed in the immediate vicinity ot
Times Beach. Suitable borrow materials were
located in investigations conducted by the U.S.
Army Corps ot Engineers...
Suitable backfill material has been identified in the immediate
vicinity of Times Beach.
The borrow pit may be developed at a rate to
match backtill requirements, depending on design ot
the remedy.
The rate of development of the borrow pit should be adjusted so
that the overall project implementation can proceed in a cost-
effective manner.
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2-49
...an 8Zcavation/~acktill cycle is 'detailed in the
tollovinq:
1. A clean dump truck enters the excavation
staqinq area.
2. The truck enters the unexcavated
contaminated zone and excavated material is
placed in the ~ed. pill height remains ~elov
the plane ot the ~ed lip.
3. The truck exits the contaminated area and
receives an exterior rinse.
4.A canvas tarp is secured over the dump trUck ~ed
and the truck proceeds to the disposal or treatment
area at Times Beach.
5. The canvas tarp is removed and the truck
dumps the contents at the storage area. The
truck ~ed is cleaned as necessary to remove
residual soil using pressure vater spray or
manual scrapers. The truck is given an exterior.
rinse at this time.
6. The dump truck proceeds to the ~orrov pit and
receives a load ot ~acktill material in the ~are
'~ed. The canvas .tarp is replaced 'an~ the. truck
returns to the remediation site. \
\
7. The truck enters on the cle&n sid~ ot the
site and ~acks across compacted ~acktill to the
working tace and dumps load.
8. The ~ed is scraped clean ot soil.
9. The truck returns to the excavation staqing area
as in 1 above and the cycle repeated.
The procedures outlined by the commentor will be considered
during design of the selected remedial alternative.
Groundwater monitorinq is not required due to the
insiqniticant concentrations ot solvents and
extremely insoluble nature ot TCDD.
Groundwater monitoring may be required in order to obtain a
state-issued permit for solid waste disposal and/or treatment of
the contaminated soil. All substantive requirements of the
permitting process must be met.
Air monitoring is not required since no previous
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2-50
air aonitorinq results have indicated any miqration
of TCDD-contaminated soil from the site. .
Previous air monitoring at Times Beach was not performed when
remedial activities were taking place. Air monitoring has been
used during removal operations at other dioxin sites in Missouri
and would be performed at Times Beach.
Lonq-term monitorinq of the site is accomplished
throuqh visual on-site inspections performed by a
qualified technician.
Additional monitoring would be performed as required to meet
long-term site objectives. .
. .
The veqetative caps should require very little
maintenance after the vegetation has been
established.
Surveillance
integrity of
be developed
the state.
and maintenance would be required to ensure that the
the cap was maintained. The specific program would
during design of the cap and would be coordinated by
section 5--Develooment of Alternatives
Alternative 6B.should be broadened to include soil
from any TCDD site in Missouri which requires
excavation.
EPA considered public comments on bringing additional material to
Times Beach and concluded that contaminated materials from other
locations not identified in the Proposed Plan would not be
brought to Times Beach for incineration. The local community has
expressed opposition to material being transported to Times Beach
for treatment from other states, or other portions of Missouri.
EPA has considered the position of the local community in
proposing and selecting a remedial alternative.
The sites identified in the Proposed Plan are related to waste
oil spraying conducted by the Bliss Waste oil Company in the
early 1970's. It is appropriate to consider a comprehensive
remedy for a group of sites located in close proximity to each
other.
The dioxin sites located in southwest Missouri are being
addressed utilizing the EPA mobile incinerator located at the
Denney farm site.
The commentor stronqly believes that EPA should
examine the "No Action" Alternative as
comprehensively as it reviews all other remediation
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2-51
Alternatives.
As noted previously, EPA believes that the no action alternative
is examined as seriously as other alternatives. The limited
technical complexity of the no action alternative limits the
amount of discussio, that can be devoted to the alternative.
...automatic sampling of surface run-off samples is
described. These automatic surface monitors must
be protected fr~r 1lood events.
Monitoring equipment would require protection from flood events.
"Once sufficient air sampling data establish a
record of no release, all air monitoring vould
cease unless significant circumstances develop
vhich vould change the site characteristics."
The specific features of a site monitoring program would be
established during predesign and design of the selected
alternative. Conti~uous ambient air monitoring would be required
during site activity to assure the safety of workers and the
local community.
...samples vould be filtered and the sediments
analyzed using high resolutio~ analysis for TCDD
concentratiol1.11
This could be a feature of a sampling and analysis program. Such
items would be developed in greater detail during the design of
the selected remedial alternatives. Detection limits in the low
. parts per trillion range can be achieved without the use of high
resolution analysis.
If data indicate that no contaminated sediment is
leaving the site, monitoring frequency viII be
reduced and eventually phased out unless site
characteristics are significantly modified."
The feasibility study describes a two-phase monitoring program
with the first phase used to define the requirements for the
second phase program. Monitoring requirements will be determined
during design.
...only tvo locations vould require monitoring of
site run-off. All other locations of major surface
drainage from this site appear to drain
uncontaminated areas.
The specific features of a monitoring program would be developed
during predesign and design of the selected alternative.
The need for both guards and fencing is unnecessary
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2-52
due to the minimal risk of exposure to site
intruders who violate the fence barrier and warninq
siqnse
The use of fencing should reduce the requirements {or full-time
securities at the site. However, some limited security would
still be required. The specific security requirements to be
implemented would be determined during selection of the remedy.
eeespecial seedinq techniques or expensive
stabilizinq materials are unwarranted durinq the
veqetation process because there has been no
indication that there is miqration of contaminated
materials... .
Special seeding or stabilizing methods would be used as required
to ensure that a vegetative cover were properly established, if
such an alternative were selected. The specific techniques to be
used would be evaluated more closely during the predesign and
design phases of the project.
EPA should identify in the feasibility study the
TCDD concentrations or level of contamination that
will triqqer the implementation of such continqency
plans.
It is beyond the scope of the feasibility study. to identify such
concentrations. If a limited action alternative were selected,
state and federal health agencies would be consulted to determine
the specific situations that would deteLmine the need for
contingency plans.
...offsite drainaqe monitorinq should be for
sediment only and not water since TCDD is attached
to the sediment and not dissolved in the water.
Since the sediment would be carried by water, it would be
necessary to collect both. Sediment samples would be dewatered
prior to analysis.
"Konitorinq of particulate and sediment from the
surface drainaqe of the site would establish a data
base which may dictate reduced frequency or
elimination of site monitorinq, or the need to
evaluate whether additional remediation is
required.
The feasibility study describes a two-phase monitoring program
with the first phase used to establish the specific requirements
for the second phase. Specific monitoring requirements would be
developed during design.
...RCRA requirements which reduce or minimize
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2-53
migration of liquids through TceD contaminated soil
are not necessary.
If requirements for a cap or cover under RCRA are determined to
be applicable or relevant and appropriate or are otherwise
necessary to provide protection of human health and the
environment, these requirements must be met. A waiver from a
potential ARAR is possible if the remedy achieves an equivalent
degree of control.
.
Any in-place containment alternative should be
designed such that its implementation will not
increase the likelihood of erosion beyond that
which currently exists. Therefore, special and
. costly measures to control erosion would not need
to be implemented for this type of construction
activity.
It is possible that the implementation of an in-place containment
alternative would inherently require soil scarification,
preparation of anchor trenches, or other activities that may
tem,(.r~rily expose contaminated soil. Erosion control may be
required for these alternatives. The specific approach would be
developed during design of the alternative.
Hydroseeding is discussed exclusively as the.
seeding technology of choice, however, any
conventional method of grass. seed application.
should be satisfactory~
other methods of seeding may be acceptable. As noted in the
feasibility study, approaches that differ from those described in
the feasibility study may be selected during predesign and
design.
Although a porous stabilizing mat should reduce
loss of clean topsoil by erosion, only in rare
cases would this expense be justified. In most
cases, a minimal amount of replacement topsoil,
followed by seeding, will repair any problem
areas...
Special stabilizing methods would be used as required to ensure
that the integrity of the cap is maintained, if this alternative
were selected. The specific technique used to repair eroded
areas would depend on the location of the area of concern.
The asphalt option or synthetic membrane should be
dropped from consideration. AD impermeable cap is
not required...
If in-place containment were selected, options such as asphalt or
synthetic membrane would be evaluated further during the
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2-54
predesign and design phases.
This ..phalt membrane will be unattractive, be very
susceptible to mechanical damage, require extensive
maintenance, be very susceptible to ultraviolet
attack and be very expensive while providing no
better protection than the soil and vegetative cap.
Any synthetic membrane which is sufficiently thick
to provide adequate mechanical strength to
withstand a gravel cover is extremely expensive.
Some of the disadvantages associated with synthetic
membranes are that they leak at the joints. As a
result of field damage, they require periodic
replacement, are very difficult to inspect without
total removal of the gravel cover, are unattractive
and are orders ot magnitude more costly than a soil
and vegetative cap.
Where access roads are required, a cap using
conventional asphalt paving techniques would
provide a very acceptable cap.
Issues regarding the selection of a specific material for capping
the site would be considered further during the predesign phase,
if this alternative were selected. The items described by the
comment or will be considered.
Because in all cases the contamination is located
alonq roads a~d in the adjacent ditches, the need
tor clearing ot brush and debris should be minimal.
The amount of brush and debris that would be cleared would be
sufficient to implement the alternative and maintain its
integrity.
Pulverizing existing asphalt and gravel road should
not be required to allow grass growth to occur on 1
foot of topsoil.
Roads would be pulverized as required to ensure the stability and
integrity of the cap material. The specific techniques used
would be determined during the predesign and design phases. The
Proposed Plan describes leaving existing pavement in place in
some areas as an additional barrier and would provide additional
protectiveness relative to the remedy described in January 16,
1987 EPA correspondence to Renate Kimbrough attached to the
Proposed Plan.
Host culverts can be eliminated and grading of the
site can accommodate most site drainage problems.
CUlverts and grading would be used as required to
maintain proper drainage at the site, if an. in-
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place containment alternative were selected.
The requirements for site drainage following implementation of
the remedy will be determined during design. Grading of the site
may not be compatible with the selected remedy.
...it should not 'be necessary to mow the site more
than twice per year.
Mowing will be performed as required to maintain the integrity of
the cover and prevent damage due to factors such as fire. The
specific amount.of mowing that would be performed would be
adjusted as required.
Because it is ,clean soil that is the focus of ,the
soil handlinq and surface preparation required by
this option, these measures can be performed with
larqe scale and very efficient equipment.
It was assumed in the feasibility study that such equipment would
be used. The specific techniques will be evaluated further
during design if this alternative were selected.
Once the veqetation is established, this method of
cappinq provides one of the most maintenance free
and low cost of maintenance remediation options
available.
. The advantages and disadvantages of a vegetative cap would be
considered further during design if an in-place containment
alternative were selected.
...a very limited amount of vehicular traffic would
be required. Where it is required, asphalt paved
access roads should be provided.
This would be considered further during design in consideration
of the requirements of the selected remedy.
Dust control durinq surface preparation should not
be any qreater than that required by any other
tarminq or excavation project.
Special precautions must be taken because of the TCDD present in
the soil, which would not be the case for most farming or
excavation projects.
The spray-on type asphalt membrane will be
relatively delicate. When the vehicles used to
apply the sand toppinq drive over the membrane it
will be damaqed. Additionally, sand is extremely
susceptible to erosion and will require continual
maintenance.
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2-56
The advantages and disadvantages.of such a material would be
considered more closely, if applicable, during design of the
remedy.
...the sand coverinq viII require significant
repair after each storm event. The necessity for
frequent repairs viII in turn cause further damaqe
to the membrane as a result of heavy vehicular
traffic in the fo~ of front-loaders and other sand
placement and qradinq equipment.
Issues such as these would be considered during predesign, when a
specific method would be chosen, if such an alternative were
selected. .
Inspection of the membrane viII be very difficult
.due to the sand coverinq.
The advantages and disadvantages of various containment methods
would be considered further during the predesign of the selected
alternative.
This technoloqy is in no respect more durable than
a soil and veqet~tive cover.
The advantages and disadvantages of various containment methods
would be considered further during the predesign of the selected
alternative, if applicable to the remedy.
...there is a qreat deal of hand vork required to
prepare the area prior to the application of the
mem])rane.
...enormous amounts of site disturbance and labor
are required to prepare for the membrane
application.
The amount of site preparation used to implement a remedial
alternative such as in-place containment would be sufficient to
ensure that the technology was properly applied and integrity
maintained. These issues would be considered during design.
This remedial. option is disadvantaqeous because of
the extensive labor (particularly hand labor)
requirements,...
EPA agrees that there are advantages and disadvantages to the
various technologies described for in-place containment. These
issues would be further considered during design if in-place
containment is a component of the selected remedy.
The unknown "durability" (of asphalt membranes) is
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2-57
a result ot misapplyinq this technoloqy to a
probl.. it was never intended .to address.
The technology, as with others, was not intended specifically to
be used for remediation at a site such as this. A key part of
the evaluation process will be to evaluate the suitability of
such technologies fo~ such an application.
The requirement to clear brush and debris should be
limited (tor a synthetic membrane).
Brush and debris would be cleared as required ~o implement the
selected alternative.
By not coverinq the synthetic membrane with soil,
sand or gravel the "liner is subjected to severe
ultra violet attack and the potential for
mechanical damage. (pp. 8-9 and 8-10)
The susceptibility of such a liner would be a function of the
material that is used. It was noted in the feasibility study
that such materials WQuld be susceptible to damage from sunlight
and are fragile. Such issues would be considered further during
predesign when a specific option would be chosen for the selected
remedial a~ternative.
Membrane rep~ir and replacement will be siqnitic&nt
since the liher has n~ protec~ive overtill.
A concern for the design of an in-place containment option would
be to minimize the repair and repla€ement requirements for such
an option. Issues such as this would be evaluated during the
predesign and design phases for the project.
...surtace prepa~ation for installation of a
synthetic membrane is extraordinary. The site
qrade must be pertectly smooth, and the application
ot a sand bed prior to membrane placement is the
preterred technique of installation. All this
requires a qreat deal of surface disturbance and
hand labor.
Issues regarding the implementation of an in-place containment
alternative would be considered further during predesign. EPA
agrees that existing surface preparation would be required for
installation of a synthetic liner. The amount of surface
preparation that would be required would be suitable for ensuring
the integrity of the containment material.
without substantial cover over the membrane, wind,
flood and ultraviolet damaqe will be siqnificant.
Labor for surtace preparation will be enormous.
Durability is very poor and replacement after 5
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years of significant portions of the liner would
not be surprisinq.
It was noted in the feasibility study that these would be
concerns for a synthetic liner used in this 'application.
The sinqle most qlarinq disadvantaqe
mentioned is the very hiqh installed
membrane material and hence the very
replacement and maintenance cost.
which was not
cost of
hiqh
A high installed cost of an option does not necessarily mean that
maintenance costs will also be high. As noted in.the feasibility
study, installation of such an option would require a substantial
amount of hand labor. Such issues would be considered further
during predesign of the selected remedial alternative. It would
be at that time that a specific process option would be selected.
The requirements of the RCRA hazardous vaste
landfill should only be addressed as they apply to
t~e specific case of TCDD contaminated soil at
Times Beach. Even .the most rigorously desiqned
TCDD contaminated soil disposal facility should
only address the potential problem areas of
erosion, dustinq and exposure to the soil.
The RCRA hazardous waste landfill regulations for dioxin wastes
are clearly laid. put in the "dioxin rule (50 FR 1978) and the
permitted facilities regulations (40 CFR 264). The requirements
for a hazardous waste landfill are relatively invariant
regardless of specific waste. The regulations are not applied
selectively, but are applied to all hazardous waste landfills
which accept RCRA wastes for disposal. .
...problem areas can be avoided by depositing the
contaminated soil on grade, or partially or totally
buryinq the soil, and then coverinq the
contaminated soil with a layer ot clean soil
followed by a veqetative cover in a "monofill"
desiqDe
As noted in the feasibility study, a monofill design would be an
option if land disposal were selected as the remedial alternative
to be implemented.
The physical properties of TCDD clearly mandate the
application ot "in-place containment" by means ot
soil and vegetative cap in lieu ot the use of
liners, leak detection and leachate collection
systems, and impervious covers which are more
expensive and scientifically unjustified.
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The recent CERCLA amendments require remedial actions to achieve
all ARARs. If a level of control of the contaminants equivalent
to an ARAR can be achieved by alternative means, a waiver from
the potential ARAR will be considered and documented in the
Record of Decision. If a soil and vegetative cap achieves an
equivalent degree of control as a cap required by an ARAR, then a
waiver from the ARAR may apply. This determination would be
documented in the proposed Plan and Record of Decision if an in-
place containment alternative were selected for implementation.
siting of any .disposal faci~ity considered for
Times Beach should be based on a flooding study of
the Times Beach site using the BEC computer model
developed by the Army .Corps of Enqineers. To
minimize the impact of the disposal facility's
effect on the flood level, the facility could be
partially buried.
The impact of various land disposal options and locations on
flood heights has been evaluated by COE using the HEC 2 computer
model. It is expected that the design of such a facility would
be prepared in close consultation with COE. Partial burial of
such a facility would be an option, although many factors would
be considered during design of such a facility.
It is stated that construction of an on-site disposal
facility in the northwest corner of Times Beach
. (a contaminated area) would require that
construction work be done in modified Level C
Protective Equipment. No risk assessment exists which
justifies this level. of protection.
Modified level C equipment is recommended by federal health
agencies during performance of certain activities during dioxin
site cleanups. This level of personal protection is typical of
removal work that has been performed by EPA at numerous Missouri
TCDD sites.
"...most samples have shown TCDD contamination in
only the upper 12 inches" and in fact nearly all
sample. at concentrations above a non-residential
Level of Concern are in the top 12 inches of
roadway. and shoulders. . The contamination at depths
of 4 feet at Quail Run were due to a utility line
installation which caused surface contamination to be
introduced to these depths. Even considerinq road
grading and rutting of the streets, the material
would not be expected at a depth below the 12 inches,
which is what has been observed.
EPA has discussed issues regarding cleanup levels for remediation
at Times Beach in previous comments. The degree of remediation
required would be consistent with guidelines recommended by state
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2-60
and federal agencies.
...RCRA regulations for conventional hazardous wastes
should not be arbitrarily applied to TCDD contaminated
soil, auch less' the extremely conservative "acute hazardous
waste provisions."
The dioxin wastes F020-F027 are listed at 40 CFR 261.3'1 as acute
hazardous wastes. This listing was promulgated upon careful
consideration and opportunity for public comment.
...BPA's November 7, .1986 Final Land Disposal
Regulations (51 Fed. Req. 40572, 40634) indicates
that ninety-five percent of the TCDP contaminated soil
in Missouri can be land disposed without restrictions.
The "land ban" regulations the commentor refers to do indicate
that most of the dioxin-contaminated soils EPA is aware of will
meet the treatment standard (40 CFR 268.41) and can be land
disposed in ~ ~ permitted landfill. The statement quoted by
the commentor does not imply that the subject soils are not
hazardous waste. Nor does it mean that soils meeting the
treatment standard can be land disposed at ordinary municipal
'landfills or other non-RCRA-permitted landfills.
Should any ~&ter bo collected for disposal, the
only necessary' method of treatment is to remove all
particulates below 5 microns. Carbon adsorption is
not necessary,...
The precise method for treatment of collected water would be
evaluated during predesign and design of site operations. EPA
anticipates that carbon adsorption treatment would be required
for such water.
Delisting should be a very straightforward process...
Delisting requirements are discussed in the noncost evaluation of
alternatives portion of the feasibility study report.
The Contingency Plan cited in the report required
the placement of a daily cover over excavated areas
which are not yet shown to be free of contamination.
This i. an unnecessary, inefficient and overly costly
procedure because currently exposed areas of Times Beach
have shown DO migration due to flooding.
A concern during excavation would be possible erosion of
contaminated soil by wind or rain. Reducing the spread of
contaminated soil from the excavated areas would be cost-
effective since it would minimize the total volume of material to
be remediated. Such issues would be further evaluated during
design of the selected alternative.
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The double lined concrete or monofill facilities
are aore appropriately applied to a conventional hazardous
waste facility for highly leachable wastes. The
containerized storag~ techni,que should not be used for
any type of hazardous waste problem. '
Various options are available for disposal of contaminated
as noted in the feasibility study. These options would be
evaluated in greate: 1etail if land disposal were selected
remedial alternative to be implemented.
soil,
as the
The polypropylene bags mentioned in the feasibility
study are difficult to fill, handle, stack, are very
susceptible to mechanical damage, and have a 'limited
life when c'onsidered as a permanent disposal container.
Semi-bulk sacks have limited potential for permanent disposal.
Semi-bulk sacks are presently used for interim storage prior to
treatment or disposal of the containerized material. The sacks
have been used with success for dioxin-contaminated removal
operations at dioxin-contaminated sites in Missouri.
. ...a more 'realistic depth of excavation would be
six inches or at most approximately 1 foot, and the
1 ppb TCDO level 'should be modified to r6flect
revised and more scientifically justified surface
and subsurface TCDD Levels of Concern...
As noted previously, the excavation approach that would be
performed would be consistent with recommendations of state and
federal public health agencies. '
The use of backhoes for a project the scale of a
Times Beach excavation is a very inefficient
utilization of manpower and equipment.
The approach and equipment described in the feasibility study is
similar to that used by EPA in successful removal operations at
TCDD sites in Missouri. other approaches may be considered
during predesign and design of the selected alternative.
strong opposition will be encountered if Missouri
TCDD contaminated soils are shipped to a disposal
site in another state. Additionally, there are no
permitted offsite disposal facilities available at
this time. These problems combined with the
tremendous cost to transport this material to an
offsite facility should preclude further
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consideration of this approach.
Alternatives for remediation of dioxin-contaminated soil are
evaluated in the feasibility study on the basis of both cost and
non-cost factors. The costs to transport the soil were included
in the cost estimates. Concerns regarding the availability of
facilities were noted in the feasibility study.
BPA proposes to require that the offsite land
disposal facility be permitted under RCRA. The
commentor considers these requirements to be overly
restrictive...
Use .of a fully permitted facility for offsite land disposal is
clearly required by the provisions of SARA, and the RCRA
regulations.
containers of any sort are unnecessary to an
efficiently designed disposal or treatment scheme.
All handling or excavated soil should be performed
in bulk. Any transport or storage can be performed
in bulk at a much lower cost and with less
potential exposure to remediation workers. ...all
container purchase, handling expenses,
decontamin~tion costs and disposal costs are
eliminated. .
Containers would be used as required to implement disposal or
treatment operations. The use of containerized versus bulk
handling would be evaluated in detail during the design of the
selected alternative. There are many issues involved with soil
handling, including risks of exposure to dioxin-contaminated soil
by site workers and the public.
Semi-bulk sacks have a relatively short useful
life. When used in this storage mode, they could
not be expected to last more than a few years
without seam failures.
Semi-bulk sacks have been used with success by EPA in removal
operations at dioxin sites in Missouri. Seam failures have not
been a significant problem to date with stored material, are not
expected to be a problem during the interim period that the
material is being stored. various methods of interim storage
would be considered during the predesign of the selected
alternative for Times Beach.
ADDendix A--site Backqround Information
...existing sampling data is not sufficient to
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serve as a basis for remediation. since the goal
of the sampling was to "detect," rather than
characterize or represent, the contamination on
site, ...ple locations were selected with
considerable bias....additional sampling would be
necessary to define the extent of excavation
necessary.
Additional sampling and analysis will be required prior to site
remediation.
...soil samples "representinq" an entire city block
were composited from materials taken from both
sides of the road, along the shoulders and in
drainage ditches. The usage of the term
"representing" is inappropriate because samplinq
was "detective" in nature...
The overall sampling program was detective in nature.
the sampling for specific areas was considered to be
representative of that area.
However,
...negative results should be qiven as much
credence as the f6W positive analyses and should
generally d6mo~st~~te that storm water run-off is
not a conce1:1l.
...seven sedi~ent samples were collected. Of
these, only three were found to contain TCDD and
these were very low levels (0.42 ppb to 0.79 ppb).
These data further substantiate that erosion and
storm water run-off is not a significant concern.
stormwater is of concern, particularly when positive dioxin
results have been encountered in several storm water sediment
samples. Higher dioxin levels have been detected in subsequent
storm water sediment sampling, and results are presented in the
feasibility study.
...most of the contamination is confined above one
foot depth. These support the concept that limited
excavation, not exceeding one foot depth, is
entirely responsive to the NCP requirements...
The degree of remediation required must be compatible with the
cleanup requirements established on the basis of recommendations
of appropriate governmental health agencies.
The report states that the sources of TCDD in the
Heramec River are believed to be run-off from Times
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Beach, Castlewood, and Romaine Creek, and possible
leachate fro. the Redbird-Simpson landfill. The
report also states that no TCDD vas detected in any
of the Xeramec River tributary sediments except
those from Romaine Creek (0.3 to 0.5 ppt). The
report fails to recognize that the Keramec River
drains a significant portion of metropolitan st.
Louis....a number of other contaminant sources
would be expected.
The cited report, "Follow-up Investigation of the Meramec River",
does not support that Times Beach is a significant source of
dioxin into the Meramec River. Other dioxin sites in the Meramec
River watershed are clearly contributing to contaminant levels
detected. Elevated dioxin levels have been detected in biota at
considerable distance upstream of the st. Louis metropolitan
area. -
...the Corps of Engineers concluded that 24 to 48
hours is the minimum time normally available for
predicting flows exceeding flood stage. This
statement seems to imply that no knowledge of
flooding potential exists prior to the actual
flood. This is an erroneous inference,...the
probability of a given flood may be assessed at any
point in time.
Although the potential for flooding can be estimated for remedial
purposes and predicted ruing the occurrence of storm events,
sufficient warning is not available to allow elimination of flood
protection measures.
Interim actions taken by EPA in 1983 (surfacing of
unpaved contaminated road shoulders and parking
lots with asphalt pavement) were overly costly and
generally unnecessary. Simply fencing many sites
would have been adequate to prevent exposure and
thereby eliminate risk.
Response Actions taken by EPA in 1983 were determined to be
necessary to provide short-term protection of public health.
These actions were justified at the time of implementation on the
basis of available data and recommendations from federal and
state health agencies.
It is stated that vertical movement of the surface
water with soil particles from the Kinker site into
the limestone is conceivable, but cites no
rationale regarding why this is believed to be so.
In the absence of well defined swallow holes in the
creek bed, this type of movement would not be
expected to occur.
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Previous hydrogeologic studies of Romaine Creek have 'determined
that surface and ground water in the area are hydraulically
connected. A dye study performed has identified a tracer
compound introduced into Romaine Creek emerging at a distant
spring.
...sontag Road would require some upgrading to
accommodate the truck traffic. The recommended
modification is 2 1/2 to 3 inches of asphalt
overlay. It is very inefficient to overlay the
actual area to be remediated for use as a haul
road. A much better solution would be to construct
a parallel haul road to accommodate truck traffic.
Upgrading of county roads...with 3 to 4 inches of
asphalt overlay to accommodate the anticipated
truck traffic is excessive...arbitrarily upgrading
roads to a much improved condition is improper use
of CERCLA funding. A better procedure would be to
split traffic between the alternate routes in order
to minimize damage to anyone route.
Such alternatives would be more closely
design phase of the project. If paving
effective, it would be used as required
remedial alternative.
considered during the
is required and cost-
to implement. the selected
ADDendix B--Public Health and Environmental Assessment
The literature published within the last two to
three years, most of which has been referenced in
this feasibility study, should have a dramatic
impact on the ultimate conclusion to this report
and the health risks presumably associated with
each of the various cleanup alternatives. All
pertinent available information on TCDD should be
considered in developing an appropriate assessment.
A number of key articles, not only on TCDD, but on
the other chemicals which are reportedly of concern
in Ti... Beach, have been overlooked.
It is suggested that most of the literature published in the last
several years has been referenced in the feasibility study, yet a
number of key articles have been overlooked. The information
pertinent to dioxin was thoroughly reviewed during preparation of
the feasibility study, and is referenced in the feasibility
study. Additional publications provided by the commentor have
been considered prior to final remedy selection.
The commentor stated that the following statement
should be substituted for a statement in the
feasibility study regarding site geology: liThe
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alluvium beneath Times Beach ranges up to 60 feet
in thickness. Alluvium consists of unconsolidated
material deposited by floodwaters. Material
directly beneath the surface at Times Beach are
younger alluvial sediments ranging in thickness
fro. la.to 40 feet and composed primarily of silts
. and clays."
The statement made ~n tne feasibility study is accurate.
It is inappropriate to base the risk assessment
conclusions on calculations which use a single
positive value as the anticipated average human
exposure.
As noted in the feasibility study the results of calculations in
the 'feasibility study represent conservative estimates of risk.
This approach is consistent with the guidelines of the Superfund
Public Health Evaluation Manual.
Insert the.following directly after the word
II depth" : . liThe 0 to 2 inch surface sample
corresponding to this highes~ concentration,
however, yielde6 a cODce~trmtion of 4.6 ug/kg.
consequently,. .6V6n the highest value detected on
site pres~~ts no direct thre&t to public health or
the envir~DL6nt since present exposure is limited
to surficial materials. II The.fact tha.t the average
depth of hiqhest TCDD levels was approximately 6
inches suggests that the intent of the National
contingency Plan (i.e. reducing of the threat, if
any exists, to public health and the environment to
an acceptable level) could be accomplished by
minimal soil excavation, although this is not the
exclusive remedy.
As noted previously, EPA has relied upon the recommendations of
appropriate state and Federal Health Agencies in establishing the
degree of remediation required for Times Beach. Other available
information regarding acceptable cleanup levels, including the
material received by the Agency during the public comment period,
has been considered in making this determination.
The distinction between alluvial groundwater and
deep groundwater should be drawn. Very few, if
any, persons in this area actually drink from the
shallow aquifers, whereas many more persons surely
drank from the lower aquifers which apparently were
not contaminated.
This distinction was identified in the feasibility study.
Although the points made by the commentor are accurate, since the
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shallow aquifer could be used for drinking water purposes, it is
appropriate to evaluate the health effects resulting from such
use.
The list of chemical properties affectinq mObility,
etc., is incomplete and confusinq.
The chemical properties relevant to the mobility of the
contaminants and critical to the evaluation of the most important
transport issues are adequately addressed in the feasibility
study.
'.
The available data indicate that TCDD may be
deqraded rather rapidly when present at the soil
surface.
Sampling conducted prior to and during response actions
implemented at other Missouri dioxin sites does not indicate that
degradation of surficial dioxin contamination is effective at
ensuring the short- or long-term protection of human health and
the environment.
It appears that there may be a "not" missinq, since
one would not expect these compounds to-
bioaccumulate or adsorb to orqanic compounds.
This error has ,been noted.
The feasibility study should define EPA'e
terminoloqy for Acceptable Intake Level (short-
term), AIS, and' Acceptable Intake Level (chronic),
AIC.
The definitions are as follows:
AIS and AIC values are derived from quantitative information
available from studies in animals (or observations made in human
epidemiologic studies) on the relationship between intake and
noncarcinogenic toxic effects. They are designed to be
protective of sensitive populations. The units for the AIS and
AIC are the same as those developed for SDI and CDI in the human
exposure phase of the public health evaluation--mg/kg body
weight/day. For teratogenic chemicals, AIS values are generally
derived for the teratogenic effects. '
AIS values are determined by a process similar to the procedure
used to develop reference dose values, except that subchronic
effects are the basis of the values instead of chronic effects.
Most AIS values are based on subchronic (10- to gO-day) animal
studies, although some are derived from human exposure data. For
chemicals without appropriate human data, the nighest subchronic
exposure level not causing adverse effects, or no-observed-
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adverse-effect level (NOAEL), is determined for all valid animal
studies available in the literature. The NOAEL is then divided
by appropriate uncertainty factors to give the AIS. Uncertainty
factors usually include a factor of 10 to account for
extrapolation from animal experiments to human effects and a
factor o~ 10 for intraspecies variability (i.e., to account for
the fact that two individuals of the same species may not react
to the same quantity of a chemical with the same level of
response) .
In general, AIC values are based on long-term animal studies.
For a few chemicals, however, ~dequate human data are available
and are used. The highest chronic exposure level not causing an
adverse effect (NOAEL) is determined by examining literature
values from all appropriate animal studies. The NOAEL value is
then divided by uncertainty factors as in AIS development.
Again, a factor of 10 is used for extrapolation from animal
effects to human effects, and a factor of.10 is used to account
for intraspecies variability. If chronic studies are not
available, subchronic NOAEL's are used and divided by an
additional factor of 10 to account for uncertainties in
ext=~pclating from subchronic to chronic exposures.
It is unclear whether either ot"these compounds
(1,1,2,2-tetrachloroethane or tric~loroethylene)
poses a siqn;ticant cancer hazard to humans at
concentrations typically encountered in
contamina~ed soil, water, or air.
The purpose of the risk assessment process is to consider the
pathways of migration and the properties of. the chemical of
concern to determine if a significant cancer risk is presented by
the chemicals in the situation presented. Such a determination
cannot be made by evaluating the cancer potencies alone.
This review ot acetone's acute and chronic toxicity
is very sparse in that it is based on only an LD-SO
and LC-SO in rodents.
It is noted in the feasibility study that the toxicity of acetone
is relatively low.
Althouqh TCDD has high acute toxicity (potency),
little TCDD has been produced and there are limited
opportunities tor exposure. In short, the risk ot
harm is low since exposure is low.
The comments made by the commentor are not relevant to the points
addressed in the feasibility study regarding the stability of
TCDD. TCDD does have a high cancer potency. The opportunities
for exposure depend on the site where exposure may occur.
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It i. important that the phenomenon of dermal
~.orption be considered in risk calculations.
Dermal absorption may be an important phenomenon in some
situations. The risk estimates for the Times Beach site
presented in the feasibility study assume however that the
potential for dermal absorption of dioxin would be limited.
"ADimal studies have also demonstrated that TCDD is
teratoqenic (causes malformities) and fetotoxic
(toxic to fetus) in mice, rats, rabbits, and
ferrets. It is fetotoxic in monkeys."
Althouqh this statement is technically true, it is
unduly alarminq, since. most chemicals have been
shown to cause developmental effects in numerous
animal species when sufficiently hiqh doses are
administered.
The statement in the feasibility study is technically correct,
and should not be considered unduly alarming.
,
The feasibility study states that TCDD is the most
potent animal carcinoqen evaluated to date by the.
SPA Carcinogen As~~ssment Group. This statement is
misleadinq and in~ppropriate. TCDD is not a potent
carcinoqen if OhS considers its carcinogenicity
relative to ita ~cu~e toxicity.
The statement made in the feasibility study is' technically
correct. When considered on a unit risk basis, the cancer
potencies of different chemicals can be compared. On the basis
of a relative potency index of the 55 chemicals that CAG has
evaluated, TCDD is the most potent carcinogen.
The fact that TCDD is 50 times as potent as BCME is
irrelevant since exposure to BCME at one point was
relatively common in several of the chemical
industries yet exposure to TCDD is rare. There
still is no evidence that TCDD is a human
carcinogen after ~o years of workplace experience
with it.
It is suggested by the commentor that there is no evidence that
TCDD is a human carcinogen after 40 years of workplace
experience, but also acknowledged that exposure to TCDD in the
workplace is rare. The potency of TCDD relative to BCME is
relevant and technically correct.
"
Under the current EPA classification scheme TCDD
might be regarded technically as a probable human
carcinoqen at sufficiently hiqh doses and with
sufficient duration of exposure. However, it is
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also important to note that the International
Aqency for Research on Cancer has concluded that
there is insufficient data to suqqest that TCDD is
a human carcinoqen. It is likely when the IARC re-
evaluates the relevant data on TCDD, it will
conclude that the data continue. to be insufficient
to suqqest that TCDD is carcinoqenic to humans~
The current EPA classification scheme is used to assess the risks
involved with dioxin exposure. It is inappropriate to conjecture
about future decisions that might be made by IARC regarding
cancer potency.
. The doses to which people have been exposed in
numerous industrial accidents, and in Seveso,. are
far hiqher than those occurrinq iri Times Beach.
This may be true for some instances of acute exposure to dioxin.
Fundamentally, 1,1,2,2-tetrachloroe~hane, and the
other chlorinated chemicals observed at this site
pose virtually no hazard to man or the environment
at the concentrations present. The feasibility
study incorrectly reviews the hazards associated
with exposure to these chemicals in the context of
doses that are orders of maqnitude hiqher than what
would be encountered at Times Beach. The
feasibility study should qive a balanced overview
of the toxicoloqical hazards that have b&en
observed for the chemical found at Ti~GS Beach and
to identify any chemicals which may merit special
considerations.
,
other non-dioxin contaminants have been detected in soils in an
isolated portion of the city park, and in a portion of the
groundwater samples collected onsite. As indicated in the
Proposed Plan, these contaminants will be evaluated independent
of the cleanup of dioxin-contaminated soils. It is appropriate
for this investigation to occur independently, due to the
relative magnitude of the dioxin problem, and since cleanup of
the dioxin-contaminated soil should not be delayed pending an
evaluation of the city park soils. Existing data indicates that
non-dioxin contamination is limited to a relatively small
quantity of soil in the city park area, and that ground water
contaminants may be limited to a thin layer of organics on the
surface of the alluvial aquifer.
It is beyond the scope for the feasibility study to develop
detailed toxicological profiles for other contaminants present
onsite since TCDD was the primary contaminant of concern. EPA
relies on other health assessment evaluations to determine the
toxicological profiles for such development. These documents,
which themselves reference other health assessment documents,
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were referenced in the feasibility study and should be consulted
for additional information.
The feasibility study properly identified the chemicals that
merited additional consideration. The rationale for selection of
chemicals for additional consideration is explained in the
feasibility study.
A well-desiqned remediation plan needs to take
consideration t~e physical properties ot the
chemical contaminant, especially when such
properties are important to desiqninq a cost-
ettective cleanup.
These types of.plans will be developed during the design phase
prior to implementation.
into
.The teasibility study states: "orqanic
contamination' was tound in several alluvial
qroundwater samples on the site. Theretore, it the
alluvial qroundwater were used as a potable water
supply, there is a potential tor users to be
exposed to contaminants throuqh inqestion,
inhalation ot volatiles (trom use durinq bathing or
cookinq), and dermal absorption (during direct
contact activities such a~ bathing)."
This observation is accurate only it the alluvial
groundwater were a potable drinking water supply
tor a residential community. However, as discussed
early in the teasibility study, there are no plans
tor this site to be used as a residential area.
Further, virtually no one in America currently
takes their drinking water trom shallow water
aquiters due to quality and seasonal variations in
availability.
Comments regarding the assumption that Times- Beach could be used
as a residential area in the future have been responded to
previously. EPA disagrees with the statement that virtually no
one in America currently takes their drinking water from shallow
aquifers.
Because ot the low quantities ot orqanics present
under the road bed and in the City Park (the source
ot the samples), the ettect on surrounding drinking
water alluvium would be negliqible.
As noted in the feasibility study, remedial investigations have
"not clearly identified the degree of contamination by other
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contaminants.
sinc. quantities and concentrations of TCDD at the
sit. viII not increase in the future, it is
unlikaly that fish f:om the Her&mec River viII ever
exceed the advisory level.
Existing data do not indicate that excessive dioxin levels in
biota are occurring due to release into the Meramec from Times
Beach. However, it is reasonable to expect that some degree of
contaminated sediment may be released to the Meramec River during
storm events, particularly during flood conditions. Due to
bioaccumulation rates as high as 30,000 reported in the
literature, any release of dioxin into the Meramec Ricer would
.warrant concern.
Dermal contact with contaminated soils or sediments
that have moved offsite due to flooding or erosion
would be negligible. consequently, the combined
exposure pathways would not be expected to pose a
human health concern.
Dermal contact with contaminated soils or sediments that have
moved offsite due to migration was not evaluated in the
feasibility study as a significant pathway of exposure.
. . .
The minimal am~unt ~f organics that could be
leached from under ~OR~ beds aDd the City Park is
markedly limite6 ~y the ~u50~ption of the organics
to the soil. As notpd in oth6r places in the
feasibility study, these chemicals are rapidly
volatilized or photodegraded in water and therefore
would not pose a hazard to fish through
bioaccumulation. These chemicals are not
bioaccumulated to a large extent due to the ability
of the fish and aquatic microbes to metabolize
them.
As noted in the feasibility study, exposure to other organic
contaminants from the site via the Meramec River is not
considered to be a significant exposure pathway.
While exposure could potentially occur offsite,
this concern is negligible. considering that the
TCDD concentration in soil which has the potential
to migrate offsite (surface soil) is extremely low
due to rapid losses from volatilization and
photodegradation, the possibility of TCDD exposure
offsite is remote.
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It was concluded in the feasibility study' that offsite migration
of dioxin does not present a significant exposure pathway.
However, volatization and photodegradation have not been
determined to effectively reduce surface dioxin concentrations to
an acceptable degree.
It is unclear why the inhalation exposure pathway
needs to be reviewed in each of the various
sections of the report since it has already been
established that inhalation is not a significant
route of entry. TCDD is not very volatile. The
particles to which it is bound are not readily
airborne. Moreover, adsorption onto particles
impedes TCDD's bioavailability.Thus, all. the data
indicate that the concern for the inhalation
pathway should be neqliqible.
It was concluded in the feasibility study that offsite migration
of TCDD does not present a significant exposure pathway. It is
not accurate to state that the particles to which dioxin is bound
are I.Ot: readily airborne. . The analysis presented in the
feasibility study estimates the risks posed by inhalation of
dioxin-contaminated particulates. .
The conversion of Times Beach to an aqricultural
settinq is inappropriate. Moreover, exposu~e
assessments presented herein indic6te that the risk
to farm workers would be low.
EPA is not recommending that the site be converted to
agricultural use. Since much of the surrounding area is
agricultural, it is considered appropriate to evaluate the
posed by such a use of the site.
risks
The commentor aqrees that the likelihood that Times
Beach will become a future residential area is very
remote. .
As noted previously, EPA does not believe that future residential
use of the site is likely.
The feasibility study states: "This assessment
assumes that any exposure to a carcinoqen could
result in cancer."
This statement refers to the assumption of linearity for low
levels of exposure to dioxin. As noted, EPA believes that any
exposure to a carcinogen could result in an increased risk of
cancer.
several hundred soil and water samples have been
collected at Times Beach. It is inconceivable that
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the hiqhest samples would be used to estimate a
feasibility worst-case level of exposure at the
sit.. Certainly a more. representative TCDD surface
concentration that people may be exposed to would
be the average TCDD concentration of less than 5
ppb rather than the single highest value measured
under pavement in Times Beach.
The most reasonable and scientific approach to the
assessment would be to take the geometric mean
value of the TCDD contamination at the soil
surface, since it is the average concentration
which will dictate the potential average human
uptake via the three routes of entry.
This comment has been responded to previously. The feasibility
study evaluates upper bound estimates of risk and notes this
assumption in the feasibility study. This approach is consistent
with the guidelines of the Superfund Public Health Evaluation
Manual. It is inappropriate to portray geometric mean dioxin
concentrations as actual average concentrations that would be
encountered. The average concentrations that would contribute to .
the estimates of risk are unknown.
It is unclear why 8 method which results in an
overestimate of the contaminant. concentration in
alr would be use~ Yhen inhalation is probably the
best understood o( all the routes of entry.
The methods used in the feasibility study to make a conservative
estimate of risk due to inhalation are appropriate.
Throughout the feasibility study, it is unclear
what concentration of dust in air was used in the
calculations.
It is stated explicitly in the feasibility study that an assumed
airborne dust concentration is 75 microgram/cubic meters.
A number of comments were made regarding ambient
level. of dust that could be expected, .
bioavailability, inhalation, and half-life.
These points are irrelevant to the calculations that were made
since the upper bound estimates were based on the the maximum
concentration of dioxin at the site that has been detected.
These assumptions are too conservative for this
setting. For example, even if an industrial use
were to be assumed for this property (which the
feasibility study is not considering as an
alternative), the water supply would not be from
the shallow alluvial water table. Any water supply
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that would be used by an industry would surely come
fro. the deep aquifer which has not been shown to
be contaminated with any ot these chemicals.
The risks that were estimated were based on the assumptions noted
in the text. The risks were conservatively estimated for a case
where the shallow aquifer was used for drinking water.
The term "carcinogen" does not apply, in a strict
sense, to trichloroethene (trichloroethylene) and
1,1,2,2-tetrachloroethane.
The use of the term "carcinogen" is consistent with CAG's
assessment of the chemicals.
It should not be assumed that all workers involved
in agricultural activities will be exposed to
airborne dust derived trom contaminated soil. Such
procedure would seriously overestimate actual
exposure.
It was assumed in the assessment presented in
study that all activities could result in the
but not that all workers would necessarily be
concentrations. .
the feasibility
generation of dust,
exposed to these
The feasibilfty study states.: "Due t~ the nature
o! the work, it i~ assumed that the. workers will
ingest 0.05 to 0.1 g/day ot soil through hand-to-
moutb activitiea~"
Although these values may be accurate; when they
are multiplied by the indefensible 1200 ppb value,
they yield a grossly exaggerated estimate of the
hazard.
As stated previously, the public health evaluation presented in
the feasibility study provides a conservative estimate of risk in
accordance with Agency policy and guidelines.
This approach to estimating the potential hazard
presented by recreational settings dramatically
overestimates the likely risk. Although it is
possible that persons might recreationally use the
site 34 days ot the year (as suggested in the
feasibility study), this is highly unlikely. It is
ever more unlikely that on each ot the .days a child
visits the site, he would ingest an average ot 0.1
g/day ot soil due to hand-to-mouth activity.
The risks that were estimated were based on the assumptions noted
in the text. As noted in the feasibility study, the risks
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estimated are considered to be 'conservative estimates of risk.
We would suggest that the value in the feasibility
study be revisited with an emphasis on changing the
1200 ppb figure to 2.5 ppb, which is the average
surface soil concentration of TCDD at Times Beach.
The actual average surface soil concentration is not known. The
statement made by the commentor contradicts points made that the
sampling done at Times Beach was intended to find the most likely
areas of contamination and does not represent a true average.
.The feasibility study states: "TCDD is toxic to a
wide variety of animals". This statement is
misleading in light of the levels of TCDD at Times
Beach.
.
The statements made in the feasibility study are technically
accurate.
The commentor made several-comments regarding the
exposure of animals and plants to TCDD.
As noted in ttie feasibility study, risks cannot be accurately
estimated for plants and animals. Calculations were not.
performed for the risk to plants and animals. A qualitative
discussion was provided.
The feasibility study states: "The cancer potency
value (used in this feasibility study) is defined
as the upper 95 percent confidence limit on the
response per unit intake of a chemical over a
lifetime (i.e., it is the slope of the dose
response and it represents only a 5 percent chance
that the probability of a response could be greater
than the estimated value for the experimental data
used). This is a conservative approach and may
overestimate the actual risk." .
The feasibility study uses the CAG cancer potency values for
estimating risks due to dioxin exposure. It was noted in the
feasibility study that the use of the CAG cancer potency was a
conservative approach and may overestimate the risk.
A major difficulty with the use of the cancer
potency value in the feasibility study is that it
concludes with a single number without indicating
its extraordinarily conservative nature.
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The feasibility study states: "Potential risks were developed
using maximum contaminant levels at the site: therefore, they
represent worse-case risk estimates."
The teasibility study states: IICarcinoqen risks
from inhalation of dusts potentially contaminated
with TCDD cannot be calculated because TCDD has no
cancer potency value throuqh the inhalation route. II
'.
Carcinogenic risks due to ,inhalation were estimated based on the.
subsequent ingestion of particles following inhalation.
Estimates due to inhalation alone could not be made because
cancer potency values due to inhalation are not available from
CAG.
The risk estimated for these quards is excessive.
It should be corrected for only two hours of,
exposure per day. It can be determined how many
minutes per day they spend in the car, and outside
ths car, aDd it the various quards rotate the
patrol duty of the Times Beach area.
The assumptions noted in the feasibility study are appropriate
for a conservative estimate of risk. .
.... The qeneralized form of the calculations
presented on paqe B-6-4 is insufticient to allow a
complete scientific review ot the appropriateness
of the mathematics. For instance, it is not clear
what dust concentration in air was used in these
calculations.
The methodology used to estimate risks is presented in the
feasibility study. Dust levels assumed have been previously
defined, and are noted in the feasibility study.
The question is what level of clean-up is needed to
protect human health and the environment. This
question can be answered only by the application of
clear, objective scientific analysis.
EPA has relied upon the judgment of appropriate state and federal
health agencies including the Centers for Disease Control and the
Missouri Division of Health in determining the level of clean-up
that is required for sites such as Times Beach. These agencies
use scientific analysis to determine appropriate cleanup levels.
The current headings of the three columns regarding
..
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the cODservatism or the lack ot cODservatism ot the
variou8 assumptions are too gross to be ot much
benetit to the risk assessment in ultimately
deciding whether the results are more likely than
not to be overstated.
The information presented in the feasibility study is appropriate
to evaluate the results of the risk assessment. The approach is
consistent with the guidelines of the Superfund Public Health
Evaluation Manual for evaluating such information.
The bounding procedure on the multi-sta~e model
will almost certainly overestimate the risks. The
overestimation is no less than a factor of 10 and
may be as high as 10,000.
The feasibility study notes that the cancer potencies that were
used would tend to overestimate the risks.
"Calculation for chemical ingestion assumes 100%
absorption into the body. The actual percentage
It ..>porbed may be less. II.
The feasibility study should state that this will,
by detinition, overestimateth~ risks.
The assumpt~on of.lOO percent absorption would conservatively
overestimate the risk.
This feasibility study 9tates: liThe exposure to
and concentration of contaminants at exposure
points is held constant over a 70-year litetime.
Chemical fate and transport mechanisms may alter
actual concentrations whioh may vary with time."
This uncertainty greatly overestimates risk.
The risk identified in the feasibility study would more likely be
conservatively overestimated than underestimated.
The feasibility study states: "Cancer potencies
and aoceptable intake levels are primarily derived
usinq laboratory animals studies and, when
available, human occupational studies.
Extrapolation ot data from high to low dose, from
one species to another, and trom one exposure route
to another introduces uncertainty."
It is not accurate to assume that uncertainty can only introduce
bias which would result in overestimation of the risk. The
statement made in the feasibility study is correct.
There is no more conservative approach to the
assessment of carcinoqenic risks than that which
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2-79
~as already been applied. It would thus seem that
these procedures can only overestimate the actual
risks. 0
Although not all the chemicals found onsite have
been assiqned cancer potencies or acceptable intake
values, these same chemicals are not present at
Levels of Concern. since the presence of these
chemicals poses a de minimus risk, it is
inappropriate to state that this uncertainty would
markedly underestimate the risk.
The statements appearing in the feasibility study are correct.
The risks presented may be overestimated or underestimated. It
is the position of EPA that a conservative approach should be
applied to the determination of risk in order to assure the
protection of human health with a high degree of confidence.
The feasibility study indicates that the
methodology for the exposure assessment involves
considerable uncertainties~ In order to assess the
validity of the methodology, at least the range of
uncertainty should be indicated.
The approach is consistent with the guidelines. of the Superfund
Public Health Evaluation Manual for presenting the results of the
risk assessment. 0 0
°If the CAG carcinogenicity potency f&ctor~ a~e to
be used in estimating cancer risks, m di~cussion of
the underlying rationale which exp'ains th6
derivation of these factors should be included.
A discussion of such rationale is beyond the scope of the
feasibility study.
The feasibility study indicates that children
ingest 0.1 gram of soil per day. There are no
references supporting this value. 0
This value is based on a thorough review of the literature.
References will be provided to the commentor.
While on p. B-5-21 the feasibility study indicates
that adults ingest 50 mg/day, line 16 of Attachment
B-1-2 feasibility study indicates that adults
ingest 100 mg/day. Whichever value is used, it
should be consistent throughout the document.
As noted in the feasibility study, both values were used to
estimate a range of risk. The example in the appendix assumed
100 mgjday.
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2-80
Finally, the body veiqht of adult males from aqes
19 to '0 is closer to 80 kq than 70 kq.
EXDosure to dioxin contaminated soil would not be limited to
maies. Therefore, using an average body weight that assumed
exposure would be inappropriate since it would not take into
account a significant group of potentially exposed persons.
assumption used in the feasibility study is appropriate.
such
The
It is hiqhly unlikely that individuals vill be
visitinq Times Beach on such a reqular basis from
aqes 5 to '0.
The assumptions noted in the feasibility study are appropriate
for a conservative estimate of risk.
Accordinq to Table B-S-2 (and elsewhere in the
feasibility study), the estimtted airborne TCDD
concentration is 0.00009 mq/m. This is based upon
the use of a TCDD soil concentration of 1200 ppb
(the maximum level measured anywhere in Times -
Beaci) and an airborne dust concentration of 75
m~m.
The 75 mg dust/m3 is a reasonable value for total suspended
particulates (TSP) in urban areas.
The commentor has clearly identified the assumptions in this
cqmment. EPA, therefore, believes that'the number was clearly
identified. '
The feasibility study reported
inhalation rate (LAAI) for the
of 0.014 q/kq/day. Thi3 value
inhalation rate of 20 m /day.
on an 8-hour day rather than a
lifetime averaqe
occupational settinq
is based on an
It should be based
24-hour day.
The hourly rate for lifetime average inhalation was used for
calculation purposes. That rate was based on an adjusted value
for the daily inhalation rate. The value of 0.014 g/kg/day was
incorrectly reported and has been noted. The values that were
used in the calculations were otherwise correctly cited in the
text.
This section deals with intake from inhalation
exposure. since only a portion of inhaled dust is
ultimately inqested and the G.I. absorption
coefficient is not 100%, a term should be
introduced into the equation to estimate the
fraction of contaminant which is absorbed via the
G.I. after inhalation exposure.
The assumption of 30 percent absorption was cited in the section
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2-81
cited by the commentor. As noted previously, sUbstantially
higher absorption rates have been determined for dioxin in
Missouri soils. The feasibility study calculations provide a
conservative estimate of risk.
A tera for qastrointestinal absorption of
noncarcinoqens found in inqested soil is present in
the proposed equation. Unless absorption is 100%,
a term should be introduced into the equation to
reflect that fr8c~i~n of inqested contaminant which
is ultimately absorbed.
It should be noted that, even assuming 100 percent absorption,
the calculated concentrations did not exceed acceptable intakes.
In the presence of a mixture of noncarc1noqens at
the concentrations found at Times Beach, the Hazard
.Index concept does not apply. Thus, the overly
conservative approach of estimatinq exposure to
each chemical is compounded further by the use of
the Hazard Index concept.
The use of hazard index is not affected by the concentration of
chemicals that are present.
ADD8ndix C--Review of Res.~~r.ch and TCDD Treatment Techno1oqy
...TCDD does not have GD affinity for water.
It is correct that dioxin has a limited affinity for water.
...the possibility of co-solvents existinq in hiqh enough
concentrations in the qroundwater to increase TCDD mobility is
very remote.
The issue discussed in this paragraph was the presence of. co-
solvents in soil. Their presence in groundwater is not relevant
to the discussion presented in the feasibility study. The
mobility of dioxin in soil is affected by the presence of co-
solvents that will increase mobility.
The objective of field tests conducted durinq the
second halt of 1985...was to demonstrate whether
the (incineration] process has any lonq term
operational limitations and provide information on
the cost of the process. ...unit treatment costs
were in excess of $1,000. per yd and the on-line
time was less than 50 percent. These fiqures call
into question the commercial viability of this
technology for this application. Subsequent field
work was.performed durinq 1986 and demonstrated
that substantial operational problems were
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2-82
encoUDtered.
The Denney Farm work was a trial, thus many costs that were
encountered would not be expected for a remedial operation. As
previ~usly discussed, the EPA mobile incinerator was not
originally designed or constructed for treatment of soils.
Operational problems that were encountered were typical of .~he
startup of any new process and have been corrected through
several modifications being made to the unit.
IT corporation's vork proves that TCDD can be
volatilized from soil by indirectly heatinq the
soil to an optimum temperature. .
IT Corporatio.n I s work "indicates that dio~in can be volatilized"
from" some soils, but does not indicate that this will be
generally true for all soils or to the degree that is necessary
for remediation.
The EPA Mobile incinerator studies demonstrate that
volatilized TCDD vapors can be destroyed in a
secondary combustion chamber.
It should be noted that the secondary combustion chamber must be
properly designed and operated for this to occur.
The capita~ and operatinq costs of this thermal
processor are substantially lover than the rot~~y
kiln technology described in the feasibility study,
yet the Shirco infrared approach vas
inappropriately eliminated from further
consideration.
As noted in the text, the Shirco unit was not "eliminated from
consideration." Such a unit could be proposed and evaluated for
use at Times Beach.
A better air pollution control device (APCD) is a
hiqh temperature baq house as described in the
Norris Report. For the TCDD-contaminated soil
found in Missouri, this is an acceptable APCD in
reqards to the 4 lb/hr BCl emission rate that would
be allowable if RCRA applies.
A high-temperature baghouse could be proposed by thermal
treatment service companies and evaluated for use at Times Beach
during the design phase of the project.
A transportable modular unit could incorporate
siqnificant desiqn improvements such as particulate
removal between the incinerator and afterburner and
still satisfy the transportable (shippable)
requirement. Installation and dismantlinq times
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2-83
will not be significantly different than for a
mobile unit.
This is an accurate statement. . Selection of specific thermal
tre~tment equipment will be the responsibility of the companies
submitting proposals for the project.
The first sentence in this sub-heading states, "The
REI is highly suitable for treating TCDD-
contaminated soil." The commentor disagrees. In
fact, the specific nature of the contamination at
this site requires a unit designed to handle low
BTU soils at maximum efficiency, which the REI does
not. .
The RKI has been demonstrated on dioxin-contaminated soils. It
has been demonstrated that the RKI is capable of achieving DREIs
exceeding 99.9999 percent. This would indicate that the
technology is highly suitable for treating dioxin-contaminated
soils.
Totally omitted from the discussion is an
evaluation of comparative thermal treatment costs,
which are required to be considered under the NCP.
.The NCP does not require that all of the variations of a
particular treatment technology be compared in the feasibility
study. It is only necessary to compare the costs of different
remedial alternatives.
The second sentence under this sub-heading states,
"Low BTU wastes, such as soil, can be sprayed with
fuel oil while being fed into the incinerator to
produce a heating value of 500 to 2,500 BTU per
pound and to increase the throughput rate." Fuel
oil used in this manner will increase purge gas
flows through the primary chamber, requiring a
larger afterburner and probably particulate removal
between the primary chamber and after burner.
Purge gas rates could be increased resulting in additional
requirements such as these mentioned. An analysis of the cost-
effectiveness of supplementing the primary source of combustion
must consider the entire process.
with its anticipated unit cost, which is .
substantially lower than the $400 to $600/yd3 that
the feasibility study presents as an estimate of
the REI cost, and its successful trial run at Times
Beach, the EII system merits greater consideration
than received in the feasibility study.
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2-84
Alternate thermal treatment technology will
the design phase of the project if proposed
The feasibility study does not rule out the
technology.
be considered during
by service companies.
use of EII
"A 1-ton-per-hour pilot unit was tested extensively
on surrogate PCB and dioxin wastes..., achievinq
'six 9's DRE from FRR alone. II This suqqests that
the operatinq temperatures which are currently
beinq used (1800 F in the rotary kiln and 2200 F in
the after burner) are excessive and can be safely
reduced...
This indicates that surrogate PCB and dioxin wastes may be
thermally treated, but does not indicate. tha.t the operating
temperatures currently being used for treatment of dioxin-
contaminated sites in Missouri are excessive.
Reference is made to IT corporation's work at
Gulfport, Hiss. where an indirect-fired rotary kiln
reduced soil concentrations of TCDD from 250 ppb to
less than 1 ppb. The test by Shirco Infrared
Systems at Times Beach is further evidence on a
small scale that indirect heatinq successfully
volatilizes TCDD from soil. ...these experiences
indicate that the indirect-tired rotary kiln
technology is a viable alternative for any soil
volume that must be incinerated.
The tests by Shirco indicate that infrared technology may be a
viable technology for thermal treatment of dioxin-contaminated'
soil.
The biqqest advantaqe tor the indirect-fired rotary
kiln is the low purqe qas flow throuqh the unit.
This reduces, not increases, capital costs as
stated in the feasibility study...
One potential advantage of an indirect-fired system would be low
purge gas flows.
...the combustion qases exhaustinq from the
indirect-fired rotary kiln's jacket are clean and
available for use to preheat soil and combustion
air, or for energy recovery.
This represents another potential feature of the technology
described.
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2-85
Previous work by IT corporation at Gulfport, Hiss.
(pages c-a, C-9) has proven the concept of TCDD
volatilization from soil.
Although IT Corporation's work is promising, the specific
conditions at the Times Beach site must be considered to evaluate
fully the concept of dioxin volatilization.
...lower volatilization and decomposition
temperatures can assure TCDD destruction.
Therefore, permitting (if necessary) should
any more difficult than for other systems.
not be
Performance-based specifications will be developed during design
which assure that all permitting and other regulatory
requirements are achieved by the remedy.
Available scientific literature does not support
the need to clean items which are contaminated up
to levels of 1000 picograms per square meter.
The level of cleanup required would be determined through tpe
recommendations of state and federal health agencies. .
No sampling or clean-up is necessary for any
structures which are to be placed in a demolition.
landfill. .
As previously stated, testing of structures and debris would be
required prior to disposal to confirm that this material can be
disposed of as non-hazardous solid waste. Decontamination would
be required if testing determines that the structures are
contaminated.
A cost benefit analysis should be performed to
determine whether the salvage value justifies the
expense of decontamination. Decontamination should
take place only where salvage value significantly
exceeds decontamination cost.
Previous testing at Times Beach has indicated that structures and
debris located onsite are not contaminated and can be salvaged or
disposed of as non-hazardous solid waste. If it is found that a
portion of this material is contaminated, the economies of
performing decontamination would be evaluated to determine if
salvage operations are cost-effective. Such an analysis. would be
performed at the predesign stage of the site remediation
operations.
Available data do not indicate that Level C
personal protection will be required at Times
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2-86
Beach.
The level of protection described in the feasibility
similar to that used for removal operations at other
in Missouri and is based on the recommendations from
state health agencies.
study is
TCDD sites
federal and
The feasibility study has dramatically overstated
the decreased efficiency from the use of this level
of personal protective equipment and this
overstatement has greatly inflated EPA's cost
estimates for this work.
The decreased efficiency due to the use of personal protective
gear, which is a result of frequent rest periods, the .necessity
for decontamination and suiting up, and the cumbersome nature of
the equipment is documented. The estimates used in the study are
based on observations during actual remedial operations.
When personal protective equipment is not
necessary, it should not be used since it may
unduly stress the cardiopulmonary sys~em as well as
increase the likelihood of heat stress. The
cumbersomeness to employees of unnecessarily
restrictive equipment should be avoided to preserve
good employee morale.
The level of protection required would be determined through
consultation with appropriate state and federal health agencies.
The level of protection that would be used would protect against
exposure to dioxin at levels that would present a risk to the
health of the worker.
section 6--Times Beach Feasibilitv Study
Sampling to date at sites where remedial excavation
activities are progressing indicates no offsite
TCDD migration of airborne dust. Similar sampling
at idle sites duplicates these results, obviating
the need for an extensive particulate sampling
program.
A single phase particulAte and sediment monitoring
approach should be adequate.
The details of the air monitoring program would be arranged
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2-87
during design of the selected alternative. As noted by the
commentor, air monitoring is being performed at other TCDD
removal sites. This sampling has verified that dust management
programs have been effective. Similar programs would be used at
Times Beach to ensure that dust migration was similarly
controlled. Continuous air monitoring would be necessary to
assure the safety of workers and local community. .
Air monitors, if absolutely required, should be
located downwind in the prevailinq wind direction
and/or at the boundary of the closest point of
routine public habitation. Sediment monitors
should be located in drainaqe ditches which drain
offsite from contaminated areas.
The details of air and sediment monitoring programs would be
addressed during the design of the program for the selected
alternative. Issues addressed by the commentor would receive
greater consideration at that time.
Proposals to erect additional fencinq, post warninq
siqns and eliminate the services of the 24-hour
site security personnel are cost effective and
sensible measures....cost estimates for
implementinq these measures have included
maintenance and repair of the fence.
Measures
security
security
remedy.
to reduce the long-t~rm costs associated with onsite
could be cost-effective. The need for continued
will be determined in consideration of the selected
(It is proposed that) sediment barriers be placed
in the major drainaqe ditches to provide rouqh
sediment deposition. It would be more reasonable
to monitor initially the sediment in existinq
drainaqe ditches and only install sediment barriers
in the unlikely event that the sediment is
demonstrated to be contaminated. The triqqerpoint
for the installation of the barriers needs to be
defined by a reasonable assessment of the risk to
health and the environment.
Sediment barriers would be installed as required to prevent
contaminated sediments for leaving the site at levels considered
by federal and state health agencies to present a public health
or environmental risk.
The construction of temporary equipment storaqe
facilities which must underqo expensive
decontamination procedures followinq completion of
the project seems extravaqant and not justified.
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2-88
only the minimum amount of equipment and personnel
should be employed to complete installation of the
caps. .
Temporary equipment storage facilities would be constructed as
required to protect equipment used at the site. The amount of
e~ipment and personnel used wou~d be adequate to implement the
selected alternative in the time required to complete the project
work.
studies have shown that veqetation does not
normally absorb~CDD, so that if the veqetation is
simply mulched and left in place, the TCDD
concentration., if any; would not be increased by
any detectable level....the established veqetative
topsoil cover would adequately prevent any TCDD
miqration from this site. Surface debris, such as
sticks and leaves should be left in place, and not
consolidated and containerized separately.
Surface debris such as sticks arid leaves would be removed as
required to implement the selected alternative. If
implementation of the cleanup would not be affected by the
presence of a portion of this material, it will be left in place
pending site restoration. This material may be removed during
restoration, depending on design criteria. The need for
consolidation and containerization of this material to facilitate
handling will be evaluated during design.
There is no justification for pulverization of the
pavement as discussed in the fifth paraqraph. with
a one foot soil cap there is sufficient depth of
soil for establishment and maintenance of a dense
qrass cover.
Pulverization would be performed as required to ensure that a
soil cap was firmly established on the areas to be covered, if
such an alternative were selected for remediation. Existing
pavement is left in place in some areas in the Proposed Plan to
provide an additional barrier. This barrier provides an
additional measure of protection for public health and the
environment, exceeding the recommendations of federal and state
health agencies, at a lower cost.
The need for new culverts can be held to a minimum
by the development of a well desiqned site qradinq
and drainaqe plan prior to implementation of the
cappinq proqram.
New culverts, as well as site grading, may be required for
implementation of any selected. remedy. Such measures would be
undertaken as required to control site drainage. The need for
culverts could be affected by other measures such as grading.
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2-89
Such issues would be considered in greater detail during the
design of the selected alternative.
The need for an extremely expensive permanent
irrigation system can be avoided by selecting
appropriate dense grass mixes or other vegetation
that will withstand the lack of summer rainfall,
and will control erosion once established. If
watering is necessary to establish initially the
vegetative cover, this can be accomplished at a
reduced cost by more temporary systems.
Since the alternative is a final remedial measure, methods would
be implemented to permanently ensure that the integrity of
remedial measures is.maintained. EPA agrees that mixes of ground
cover should be selected that would be able to withstand the lack
of summer rainfall and would control erosion. If such materials
could be found that would meet the site objectives, the need for
permanent irrigation may be reduced.
...disposal costs for protective equipment can be
eliminated if uniforms are used that can be washed
on a daily basis.
The level of protective gear assumed in the feasibility study is
similar .to that used for removal activities by EPA at other.TCDD
sites in Missouri based upon recommendations of federal and state
health agencies. If other types of protective equipment is
deemed appropriate by health agencies, it may be considered for
use during remedial activities at Times Beach. Such issues would
be addressed during design of the selected remedial alternative.
...a more cost effective method of disposing of the
decontamination rinse water is to utilize it for
dust control at already-contaminated remediation
work areas.
This possibility will be evaluated further during design and
predesign of the selected alternative.
In the event that EPA determines that the sand and
carbon filters are nevertheless required, the
filter materials should be disposed of beneath the
clean topsoil cover in an area of confirmed TCDD
contamination. .
This option for disposal of the filter material will be evaluated
in greater detail during the predesign and design phases of the
project.
...the ditches should. be filled and a smooth,
gently tapered soil covering placed over the road
and road shoulders.
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2-91
minimal level of protection. The required equipment is coveralls
and steel-toed leather or chemical-resistant boots or shoes.
Hard hats would be optional equipment.
No additional fencing vould be required around the
site perimeter because the assiqned security guards
could adequately proteci. the site.
Additional fencing would be installed as required to ensure that
equipment is protected and intruders prevented from contacting
the contaminated areas. .
TCDD does not migrate in response to vater
percolating through the soil...as a consequence,
the disposal facility 'and ~laborate leachate
treatment system described in the feasibility study
[for the land disposal facility] is not
scientifically or technically justified. Such a
system is enormously expensive and requires
operating costs in perpetuity.
As noted previously, a collection and treatment system would be
required for the land disposal facility. . The system would be
expected to operate primarily during the early portion of the
project when the facility was open a~d being filled~ After the
facility had been closed, leachate generation would be expected
to become negligible, except for the unusual occurrence of a
breach "in the cover for the facility. It would be necessary to
maintain the equipment. in good working order in case such an
occurrence did occur.
...the top of the concrete valls of any onsite land
disposal structure, if constructed need only be one
foot above the 100 year flood elevation. This
reduces the amount of borrow and backfill prior to
construction, and the amount of borrow and backfill
to cover completely the container.
The specific height of the disposal facilities' walls would be
selected to minimize the potential for floodwater overrunning the
top of the wall.
The commentor recommends elimination of the
"polymeric asphalt coating or synthetic liner"
intended by EPA to serve as an impermeable coating
for the concrete. These liners or coatings leak
immediately after installation, reducing their
effectiveness as an impermeable barrier. In
addition, the concrete can be designed to be as
impermeable to sediment transport as a liner or
coating....a secondary leachate collection system
viII be available as a back-up system, thereby
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2-92
reducing the need for the liner or coating.
Coatings or liners would be required for a permanent disposal
facility. The specific coatings that would be required would be
selected following additional evaluation during the design phases
of the project.
..."leachate collected in the leak-detection system
would be pumped to the leachate treatment system."
The commentor does not anticipate that this measure
will be ~equired because it is unlikely that the
. groundwater or floodwater beneath the concrete
container will be contaminated. It would be more
advisable to sample this water prior to treatment
to ~etermine if treatment were. necessary. .
In the event of a flood, it is unlikely that time would permit
sampling and analysis of groundwater or floodwater beneath the
facility. One purpose of collection and treatment would be to
minimize the potential for uplift that could damage the facility.
The commentor disagrees with EPA that a function of
the cap that covers the filled concrete disposal
facility is to prevent percolation of rainwater
into the cont~inated soil..~.The major function of
this cap is to prevent public exposure to the
contaminated soils.
Although a function of a cap is to prevent public exposure to
contaminated soils, a cap is also intended to prevent percolation
of rainwater.
The leachate treatment system envisioned by EPA
would be capable of handling flows from a 24-hour-
long, 25-year storm....a system sized to handle
this volume of rainfall is not required...
As noted previously, EPA believes that such sizing is required to
prevent damage to containment facility. The specific sizing of
the equipment would be determined during design of such a
facility, if included in the selected remedial alternative. The
proposed remedy does not. include the need for a leachate
collection system. Water treatment requirements will be
dependent upon the design of the remedy.
...The commentor recommends that the TCDD removal
efficiency of 99.9% of total TCDD be expressed as a
discharge criteria for the treated water, such as
the 10-ppt limit which EPA uses at the Denney Farm
site.
Discharge of treated water will be in accordance with federal and
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2-93
state water quality laws and regulations which are determined to
be applicable or relevant and appropriate.
Level C protection
excessive for most
Level D protection
remedial tasks and
and efficiency.
The level of protection described in the feasibility study is
typical of that used during removal operations at other dioxin
sites in Missouri. Alternative levels would be considered if
their use was approved by appropriate state and federal health
agencies. These issues would receive additional consideration
during the design of the selected alternative.
as described...would be
remediation activities. EPA
is more suitable for most of the
provides enhanced worker comfort
...no advantage is gained by employing steam
cleaning of containers and trucks versus high
pressure water spray or water spray combined with
detergents. steam cleaning is dangerous and
expensive and does not remove TCDD more efficiently
than these other methods.
The specific cleaning method employed would receive additional
consideration during the design of the selected alternative.
steam cleaning would minimize the amount of decontamination water
requiring later treatment. Steam cleaning, as well as the other
methods suggested by the commentor, would be evaluated for cost-
effectiveness. . .
The commentor rejects EPA's conclusion that long-
term groundwater monitoring is required after
closure.
Ground water monitoring will be performed, if required by state-
issued permit conditions.
EPA will be requiring 1I...periodic inspection of
the disposal facility walls for leaks, cracks, and
distortion. II Since these walls are buried, these
inspections would require total excavation of the
soil fill around the concrete facility. This is
both absurd and totally cost prohibitive. No
inspections should be performed unless a
significant shift in the soil mound covering the
container occurs.
The passage refers to general RCRA requirements. The cost of
operation and maintenance is included in the determination of
cost-effectiveness for each of the remedial alternatives.
The only aspects of the outlined operation and
maintenance activities which should be undertaken
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2-94
are those activities which involve maintenance of
the security system and of the culverts and
ditches. Leachate collection and treatment are
unnecessary and consequently there will be no
associated maintenance required.
Leachate collection and treatment would be necessary for a land
disposal facility, for reasons noted previously.
This option requires that a commercial landfill
facility be located in the vicinity of Times Beach,
or that an upqraded sanitary landfill be .
constructed and permitted. Neither of these
currently exist, nor is the probability very hiqh
that such a facility will be constructed in the.
near future. .
It was not assumed in the feasibility study that a commercial.
landfill facility would be constructed in the vicinity of Times
Beach. It was noted in the feasibility study that such a
facility could be a considerable distance from Times Beach.
EPA proposes' to construct an 8 foot hiqh perimeter
fence around the Times Beach site. This is an
economically unjustified use of CERCLA funds
because the security quards detailed to the project
can adequately protect the site, and because the
fencinq will have to be removed followinq
remediation efforts.. V
\
EPA will construct fences as required to implement the remedial
alternatives. The level of security that would be required
should be adequate to prevent intruders from entering the site
and contacting contaminated material and also prevent vandalism.
Security requirements will be adjusted in consideration of the
selected remedy.
...the maximum equipment required to protect
workers from exposure to TCDD is disposable dust
masks and washable clothinq.
As noted previously, the level of protection described in the
feasibility study is typical of that used during removal
operations at other TCDD sites in Missouri based upon
recommendations of state and federal health agencies.
Alternative levels would be considered if their use was approved
by health agencies. These issues would receive additional
consideration during the design of the selected alternative.
An indirect-fired rotary kiln with dry pollution
control is a much preferred method of treatinq low
level contaminated soil. This technoloqy is less
costly, more reliable than other thermal treatment
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2-95
techniques, and it can meet all Pederal, state and
local performance requirements.
If the proposed technology is cost-effective, EPA would .
anticipate receiving proposals for the project incorpordting its
use. .
EPA would require the installation of an 8-foot
perimeter fence around the entire site. The
commentor recommends that EPA only install such a
fence around the thermal treatment facility because
the security quards can adequately prevent
unauthorized pe~sonnel from entering the site.
Fencing would' be installed as required to prevent contact with
contaminated soil and prevent vandalism of equipment.
EPA indicates that the incinerators and ancillary
equipment would require a power supply'of
approximately 800 kw....much less power should be
required to operate the incinerators.
The level of power noted in the feasibility study is similar to
that noted by service companies operating full-scale mobile,
incinerators. The pow~r requirements would be determined by the
technology utilized by the successful bidder.
EPA estimates that approximately 28 acres would be
required for the thermal treatment facility. A 28-
acre site is unreasonably large due to the 4 month
soil storage requirement, and the requirements for
elaborate and unnecessary water treatment of the
scrubber blowdown.
EPA believes that 4 months of storage would be approximately
correct for treatment of Times Beach soils only. The flood-
protected acreage assumed on the Proposed Plan was substantially
reduced. Actual requirements would be determined during design.
...there is no need to gravel the entire
incinerator site.
The site would only be graveled as required to support equipment,
storage areas, and roads.
...design of the facility to provide protection
from a 100 year flood event is inappropriate for a
temporary facility projected to have a relatively
short life.
The facility will need to be flood-protected to prevent damage to
facilities in the event of a flood. The incinerator, which would
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2-96
require a minimum of 6
removed quickly enough
occurred. Hence, even
short-lived, given the
facility would need to
weeks for dismantling, could not be
to prevent flood damage if a flood
though the facility would be relatively
nature of flooding at the site, the
be thoroughly flood protected.
EPA proposes to construct diked tauk
areas....liquid storage tanks and dikes viII
necessary if a dry air pollution control is
utilized.
not be
Chemicals are likely to b~ required, even for a dry, scrubbing
system, so the complete elimination of diked tank areas is
unlikely. A dry scrubbing system, if offered by thermal
treatment service companies propos'ing to work on the proj ect".
would be carefully considered during the design phase for the
project.
Because there is so little chlorinated material in
the soil at Times Beach, BCl generation would not
surpass the four pounds per hour allowed by RCRA.
There(ore the reference to caustic storage or
neutralization of BCl should be deleted.
Caustic would likely be required for the quench process that
would be required for ,a dry process, so it is unlikely that its
use would be discontinued. If its use was not required, it would
not be used.
EPA would construct a well producing at least 70
qpm of water to be used for sCrubbing exhaust air
from the secondary combustion chamber. If a dry
pollution control system were utilized, this volume
of water would not be required. The well would
only need to supply that volume of water necessary
to support the waste heat boiler system....only 40
qpm for both units would be required...
The volume of well water required may indeed be reduced with a
dry scrubbing system over a wet scrubbing system.
...there are three former municipal wells and a
water storage tank which could be brought back into
service instead of drilling a new 70 qpm well at a
cost of more than $200,000.
If the existing wells could be brought into service, supply the
water needed, and be set up at a lower cost than installing a new'
well, the existing wells would be used.
A sump to store run-off from a 25-year rainfall is
unnecessary [to contain stormwater within the -ring
levee] because EPA proposes to containerize the
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2-97
soil....a sump to hold 932,000 qallons of water is
required, which appears to be excessively larqe.
EPA believes that the assumptions noted in. the feasibility study
are justified. Additicnal consideration would be given to .this
issue during project design.
The incinerator
unrealistically
shift of set-up
and can be very
set-up time of six weeks is
short, and the use of a second
workers has limited effectiveness
costly.
The incinerator setup time is that suggested by several thermal
treatment s~rvice companies that offer onsite mobile incineration
services. six weeks is not considered to .be unrealistic.
Scheduling of shifts will be the responsibility of the
construction contractor.
EPA notes that the trial burn plan is to be
submitted after the preliminary shakedown of the
thermal treatment unit. A preferred approach which
would minimize delay and downtime for the unit
would be to submit the trial burn plan for approval
durinq the desiqn and construction of the unit.
. Delays woul.d be minimized if.the plan could be offered prior to
preliminary shakedown of the unit.
There is no need to load the excavated material
into 15 cubic yard bins which are estimated to cost
over $9,000,000 to purchase....bins are hard to
fill, require very awkward and expensive equipment
to move them and do not provide any operational
improvements.
There are several advantages to the use of bins for such an
operation. The specific handling method may differ from that
described, however, and would be determined during design of the
selected alternatives.
A straiqht line confiquration of the rotary kiln
and the afterburner has proven to be unfeasible at
the Denney Farm due to particulate carry-over into
the afterburner. A desiqn to facilitate
particulate removal must be employed.
Modifications have been made to the EPA mobile incinerator since
the Denney Farm trial that will reduce the particulate carry-over
into the afterburner. Similar modifications have been made to
commercially available rotary kilns. A straight-line
configuration could, therefore, be used successfully.
The units should not remain mounted on trailers
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2-98
because this overly complicates their operation.
They could be made transpor~able...
The decision to keep the thermal treatment units trailer-mounted
would be'left to those proposing to perform the onsite thermal
treatment services.
...a mobile' system versus a transportable component
system constructed on-site is not justified due to
the very large magnitude of the project. The
additional costs to construct a mobile incinerator
(trailer chassis, quick connect electric systems,
etc.) instead of a skid mounted transportable
system are not merited for a project which will
,extend over several, years and not several months.
Mobile incinerators have already been constructed and are in
operation. since a new mobile incinerator would not necessarily
have to be built, construction of such a unit would not
necessarily be an issue for the site. Any transportable thermal
treatment unit capable of satisfying the performance objectives,
including mobile units, would be considered if proposed.
The wet scrubber unit should be replaced with a
high temperature baghouse for final particulate
contrQl.
This is a possibility,. but would be left up to those proposing to
offer thermal treatment services. Such a unit would be required
to meet required performance objectives.
Additional efficiency, reduced maintenance and
space requirements can be gained by using one
larger incinerator instead of two smaller units.
There may be some benefit to operating a larger incinerator over
several smaller ones. Two units were assumed in the feasibility
study to increase capacity. If it is cost effective to operate a
single larger unit, proposals should reflect this.
Any excessive downtime due to having only one
treatment unit can be avoided by an effective
preventive maintenance program which is scheduled
in advance.
A preventive maintenance program would help reduce unscheduled
downtime for the thermal treatment unit. Some unscheduled
downtime would be unavoidable.
...the contaminated soils feed rate is listed as
8.5 cubic yards/hour...yet the footnote indicates
that the mass flows given are total values typical
for 6 cubic yards/hour contaminated soil feed.
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2-99
The contaminated feed rate for two mobile incinerators, based on
the assumptions noted in the text, would be approximately 8.5
cubic yards/hour. This error has been noted.
The steam generated by the waste heat boiler should
be used to preheat combustion air or to preheat the
feed soil.
The use of waste heat would be determined by the company
proposing to offer the incineration services.
Higher heat inputs would be expected in the rotary
kiln incinerator than in the afterburner. EPA
should re-examine these numbers which will affect
the soil treating capacity of the unit.
The throughput of the incinerator was estimated through heat and
material balance calculations using the assumptions noted in the
text. The thermal limitations in the incinerator are the same as
for commercially available units. As noted in the text, the
throughput is affected by the moisture content of the soil that
is assumed. The rates that were estimated are similar to those
actually experienced in the field on low-Btu content soils. EPA
expects that the rates experienced with similar soil using a
similar incinerator would be close to those .estimated through the
rigorous heat and mate~ial balance calculations.
...an effective throughput of 8.5 cubic yards/hour
is assumed...this effective rate is not found
anywhere in Appendix E of the feasibility study
where costs are estimated.
In Appendix E, the operating cost per cubic yard of material of
one incinerator is estimated. This cost is estimated at a range
of throughputs, including 4.25 cubic yards per hour, which is the
rate estimated though a rigorous heat and material balance. If
two incinerators were used, each operating at 4.25 cubic yards
per hours, the combined throughput would be 8.5 cubic yards per
hour. The unit cost per cubic yard for the two incinerators
would be the same as for one, and the cost per hour would
approximately double.
...the kiln exit temperature of 1600 degrees F
....has been proven at the Denney Farm site but
substantial fuel savings may be realized if this
temperature could be reduced. Experimentation with
this variable could drastically reduce fuel costs,
by as much as $500,000 for only a 7% reduction in
fuel usage. The same reasoning applies to the
afterburner temperature of 2200 degrees F.
Fuel reductions would be possible if the incinerator could be
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2-100
operated at lower temperatures.
contemplated unless it could be
destruction would be maintained
lower temperatures.
Such operation would not be
demonstrated that required dioxin
and performance objectives met at
In the Nether1ands...a direct spray co01inq system
has been employed which uses water to cool the ash
as well as to rehumidify the ash. This
rehumiditication allows the ash to be more readily
land applied.
Different options for cooling the ash would be
thermal treatment services companies proposing
project. It is possible that a system similar
by the commentor could be proposed. .
proposed by the
to work on the
to that suggested
...ash will be transferred from the thermal
treatment unit to the land application area in the
15 cubic yard, roll-off bins. Bulk handlinq of
this now contamination-free ash is simpler and more
cost effective.
Bulk handling
operations at
conveyed from
the ash would
project.
may be possible, although onsite incinerator
other sites have containerized the ash as it was
the ~ncinerator. Issues regarding the handling of
be considered' during the design phase fo'r the
...redundant power supplies are not necessary. .
Safety is ensured without a redundant power supply
by implementinq a process whereby soil feedinq
mechanisms are interlocked to stop feedinq soil on
flame-out in either combustion chamber. It there
is a power failure, the soil feedinq equipment
ceases operation. The heat stored in the
refractories of the combustion chambers is adequate
to keep the qas temperatures sufficiently hiqh to
destroy the vaporized TCDD within the unit.
Redundant power supplies would be used as required to ensure that
the incinerator could be safely operated and risks minimized.
Issues regarding the use of power supplies would be evaluated
further during the predesign and design phases of the project.
The need for upqradinq of roads, pilot cars and
other costly measures to transport the baqqed soil
from these sites is not justified by the scale or
risk associated with each transport project.
Road upgrading and other transportation. control measures would be
used as required to ensure that the soil could be safely
transported.
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section 7-~Noncost Analvsis of Alternatives
...the last paragraph on the page states that
"...the no-action alternative would provide no
access restrictions...n, this is inconsistent yith
descriptions of the No Action Alternative in
sections 4 and 5. ...the No Action Alternative
would be a viable alternative if appropriate site
security measures were implemented.
By definition, the no action alternative would not include
access restrictions. Such measures would, however, be required
to control. potential exposure if no further measures were
implemented.
...the installation of ring levees 'or other flood
control measures is not justified by the site
characteristics, and this work should be halted
immediately.
The Times Beach site has encountered repeated flooding. This is
a characteristic of the site. The use of flood control measures
are clearly needed to reduce the effects of such occurrences.
The spur levees are being constructed to reduce water velocity
during flood events to minimize scour and erosion. The Ring
Levee is required to flood protect the thermal treatment unit
during implementation.
...the reliability'of enhanced vegetation and
sediment barriers is very high for a contaminant
such as TCDD.
As noted in the feasibility study, reliability includes operation
and maintenance requirements and demonstrated and expected
reliability. Periodic operation and maintenance would be
required to maintain the effectiveness of enhanced vegetation and
sediment barriers.
While some
desirable,
of what is
and of the
limited confirmatory monitoring may be
it is certainly not necessary, in light
known about the characteristics of TCDD
Times Beach site.
A monitoring plan will be developed during the design phase of
the project.
The minimal concerns of maintaining grass cover
[for in-place containment], etc. are insignificant
and no more difficult than growing grass in a
residential yard. Inspection of the site in its
current state indicates that there will be little
difficulty in providing a substantial vegetative
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2-102
cover.
The difficulties of maintaining grass cover would certainly be
more difficult than growing grass in a residential yard. The
substantial area involved, the lack of continual care as would be
typical for a residential area, the potential for flooding, the
presence of TCDD below the cover and need to prevent exposure to
the material, and the contour of the soil cover would all
contribute to making maintenance more difficult than for a
typical residential yard. :
The concern expressed by EPA that transportation of .
larqe quantities'of offsite borrow.to Times Beach.
poses a risk of automobile accidents durinq
implementation of Alternative 3 is qroundless.
There is a borrow site on the south side of
interstate hiqhway Interstate 44 sUfficiently larqe
for this project which vill not impact local
traffic flow.
The specific location where borrow would be obtained has not been
determined. If the location on the south side of Interstate 44
were used, tra~fic difficulties would be minimized.
...there is no need for leachate collection or
treatme~t if leachate is not qenerated~
Leachate would almost certainly be generated during the period
when the land disposal facility was being filled and a cover
constructed. .
constructability of a suitable monofill in the
Times Beach floodplain is not a major problem.
Placement of a protective cover can proceed
concurrently with placement of the contaminated
fill material.
Construction of a land disposal facility in a flood plain would
require the use of many specially engineered features not required
for a similar facility not constructed in a flood plain. Some
work on the cover of such a facility may be performed during
filling operations for the facility.
The use of the term "leachinq" with respect to
sediment is improper. Leachinq qenerally refers to
the mobilization and transport of contaminants in
solution.
As used in the feasibility study, leaching refers to the movement
of water through stored TCDD-contaminated soil. The use of this
term is consistent with accepted use of the word, which means to
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2-103
cause a liquid to filter down through some material.
A monofill, minus the necessary liners, leachate
collection, and leak detection systems, would
provide no potential for erosion of TCDD
contaminated sediment other than from the surface.
Erosion of material is typically a surface phenomenon, thus if
erosion were to occur from any contaminant facility, it would
likely occur at the exposed surface. The fact that surface
erosio~ could occur from a monofill affects the suitability of
such a method for disposal of dioxin-contaminated soil.
Traf~ic accidents are a risk associated with all of
the Alternatives, as well as any heavy construction
project. These risks are minimized by proper
construction management.
It should be noted that alternatives that require more transport
than others have a higher risk of accidents. Precautions will be
taken to minimize the potential for accidents.
EPA indicates that some minimal risks of exposure
would remain from potential leaching of TCDD from
the disposal facility. This conclusion is much
more relevant to a commercial facility than it is .
to onsite land disposal at Times Beach. .
This is consistent with the feasibility study.
...onsite land disposal is a much more
environmentally sound solution than offsite land
disposal at a commercial facility.
Offsite land disposal would present some environmental risk due
to the transport of contaminated soil, and increased potential
for leachate generation.
The fact that no landfill disposal facilities have
obtained the necessary permits to store TCDD-
contaminated material, and apparently have shown
little interest in accepting dioxin contaminated
material, confirms the obvious infeasibility of
this Alternative.
There are implementability issues involved with the offsite land
disposal alternative.
The reliability of the incinerator is a function of
proper design and proper project management.
Proper design, construction, and operation should assure the
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2-104
reliability of the thermal treatment unit.
...constructability of the incinerator facility in
the floodplain at Times Beach, presents no major
problem. .
A thermal treatment facility could be designed and constructed
for use in the Times Beach floodplain. Such a facility would
include specially engineered features to minimize the effects of a
flood if it were to occur.
The commentor states that the use of delistable
residues as backfill in excavated areas should be
integral to the incineration project. .
This option should be considered during design. Residues must be
disposed of in accordance with federal and state laws,
regulations, and standards that are determined to be applicable
or relevant and appropriate.
...the problems cited at the Denney Farm mobile
incinerator relate to a small, experimental,
direct-fired incinerator. An indirect-fired rotary
kiln, specifically designed to process large
quanti ties of Times Beach soils,. would not be
expected to experience. these problems.
. . . .
Many of the operational problems encountered at Denney F~rm were
solved during the operations there. Although an indirect-fired
kiln may indeed not experience the same types of problems, it is
e.xpected that the experience gained at Denney Farm should help
prevent similar problems for the many types of thermal treatment
equipment that could be used at Times Beach.
EPA notes that transportation of materials to and
from the site could be difficult in the winter due
to adverse driving conditions. ...dealing with
such problems represents another routine element of
proper project management. Similarly, proper
project management ensures that a competent staff
will be maintained for the duration of the project.
These are among the important issues that must be considered
during the design and selection process for a thermal treatment
project.
...this alternative (offsite treatment) is not
practical due to the excessive costs associated
with land acquisition and material transportation.
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2-105
Costs for land acquisition and transportation are important
factors for this alternative which will be considered in making
the final selection of the remedy.
...it is hiqhly unlikely that any remedial action
at Times Beach would have any effect on the
concentration of dioxin in the Heramec River. In
addition, the concept of a "discharqe" into
drainaqe ditches used in the feasibility study is
. foreiqn to the Clean Water Act. For these reasons,
amonq others, use of water quality criteria as a
"relevant and appropriate" requirement for various
Times Beach alternatives considered is not
justified. . .
There does exist a small potential for further contaminating the
Meramec. contamination can be avoided by use of proper techniques
during the remedial actions. Lack of proper care could result in
discharge to the river.' .
In discussing the water quality criteria in the feasibility
study, it was not EPA's intention to imply that a discharge
regulated under the Clean Water Act would definitely be involved
in implementing the alternatives examined. Rather, it was the
Agency's purpose to examine regulations which address dioxin
contamination and to explore their applicability to the situation
at Times Beach and to the remedial alternatives considered in the
Feasibility Study.
. ...it appears to have excluded from consideration a
limited action "cappinq" alternative that attains
or exceeds any arquably relevant and appropriate
RCRA closure requirements. ...EPA's choice of
materials for its proposed cap caused its limited
action alternative to fail to meet the RCRA
requirements.
The alternatives examined are intended only to present a range of
alternatives and costs. Alternatives not specifically described
in the Feasibility study (including use of an impermeable cap)
are not eliminated from consideration or selection. The NCP
decision process allows selection of remedies which differ in
detail from those in the Feasibility study. Thus, alternatives
utilizing an impermeable cap have not been eliminated from the
range of alternatives being considered by EPA. Placement of a
cap meeting RCRA requirements was evaluated in the Proposed Plan.
EPA also fails to explain why it did not rule out
the more costly incineration and offsite disposal
alternatives under 40 CFR. 300.68(q) (3), which
states, "If an alternative has siqnificant adverse
effects, and very limited environmental benefits,
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2-106
it shall also be excluded from further
consideration."
Incineration and offsite disposal do not have significant advarse
effects.. The potential for adverse effects from both.
alternatives can be addressed with proper engineering and
procedures. The benefits of permanently removing the dioxin from
the environment must be considered in evaluating the incineration
alternative.
EPA correctly notes...that ARARs need not be
attained "under one of six exemptions." . ...the
feasibility study states, "No attempt is made to
determine which, if any, of the requirements might
fit one or more of the exceptions in the NCP or
SARA. That is a decision that must be made by EPA
and published as a finding of the. Administrator,
presumably after public comment." EPA, however,
implies that further opportunity for public comment
may not occur...
The feasibility study was prepared by an EPA contractor. . It is
an engineering study prepared for EPA and avoids making Agency
decisions. Opportunity for further public comment was prqvided
in response to the Proposed Plan, which discussed potential
waivers from ARARs.
The feasibility study is deficient in failing to
set forth "findings, together with an explanation
and appropriate documentation" for the exercise (or
non-exercise) of each of these waivers.
The language of SARA is very clear in requiring the President to
publish findings, etc., in cases in which he decides to exercise
one or more the six exemptions. At the time of the publication
of the Feasibility Study, no decision had been made by EPA
regarding. the applicability of potential waivers from ARARs.
Thus, no "findings," "explanations," or "documentation" were
required.
...there is no law, regulation, policy or standard
under either Federal or State law which purports to
establish this 1 ppb level of concern criterion for
TCDD.
The wording of SARA refers to "any standard, requirement,
criteria, or limitation...," not "law, regulation, policy, or
standard." EPA believes the 1-ppb standard for residential soil
can be appropriately considered to fall into one or more of the
categories mentioned by SARA. In cases where laws, regulations,
and standards do not exist, the EPA can rely upon recommendations
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2-107
from federal and state health agencies to determine appropriate
levels of concern for protection of public health and the
environment.
888;he superfund Guideline states that a 10-4 to
10- risk may be used. More importantly, the
Guidelines recommend incorporation of site. specific
factors.
These guidelines may be used for consideration of health risks
posed by the site.
The feasibility study assumes that onsite cleanups.
require permits. The study also assumes that the
absence of permitting requirements for a technology
preclude the use of that technology in an onsite
CERCLA action. These statements are wrong.
SARA clearly eliminates the requirement for permits for those
portions of a remedial action that occur entirely onsite.
Further, the discussion of the absence of permitting requirements
for certain technologies does not imply that this use at Times
Beach is precluded. A new offsite unit could be permitted for
use in .the Times Beach r€mediation if appropriate permitting
regulations were developed or identified.
The feasibility study also fails to consider
CERCLA's express preference for alternative
treatment technologies,... The failure by the
feasibility study to adequately consider
alternative thermal treatment technologies,
particularly indirect fired thermal treatment
technologies...and the "permit" assumption cause
the feasibility study to overstate the costs of
permanently destroying TCDD in soils at Times
Beach.
SARA clearly states a preference for permanent remedies and
expressly allows for use of technologies that. have not been
utilized at similar sites. Nothing in the Feasibility Study
eliminates indirect-fired thermal treatment from specific
consideration for the project, if advantages exist that warrant
its use.
It is unlikely that a Times Beach guard hired to
patrol a so-called hazardous area would
accidentally ingest significant quantities of dirt
by smoking or eating while driving in a police car
through the site during perhaps 2 hr of every 8 hr
day. Further, there is no reason to believe that
the airborne levels of dust to which he or she is
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2-108
exposed are any greater than the ambient dust
levels for that area...
As noted in the feasibility study, a .conservative approach was
used to estimate risks posed by the site. This approach is
compatible with the requirements of the Superfund Public Health
Evaluation Manual.
It is not enough to say that since exposure is
reduced, so must be the risk. Alternatives II,
III, IV, V and VI do not clearly quantitate how the
level of risk vill be reduced if and vhen these
alternatives are adopted.
EPA believes that the selected alternative must meet cleanup
levels established by EPA on the basis of the recommendations of
appropriate governmental health agencies for protection of public
health and the environment.
section 8--Cost Analysis of Alternatives
...more accurate cost estimates than the "Order of
M~gni tude Estimates!' can be mad.e. Not only can the'
estimates be more accurate but they vill be
drastically reduced from the el~vated forecasts
vhich have been presented in the feasibility study.
There is no reason to believe that an order of
magnitude estimation procedure is necessary or
appropriate for this feasibility study. Instead, a
cost estimate with no more than 10-20% leeway vould
be considered more appropriate... ...the current
site information available is more than adequate to
re-estimate the remedial costs with a better
accuracy than +50%/-30%.
As defined by the American Association of Cost Engineers, an
order-of-magnitude cost estimate is an estimate produced without
detailed engineering data. More accurate estimates (budgetary or
design estimates) require the use of layouts, flow diagrams,
etc., of the actual process to be installed. This type of
information is clearly not available at the Feasibility Study
stage. EPA guidance recognizes that study-level estimates will
have an accuracy of +50 percent to -30 percent and that more
accurate estimates are not necessary at the study stage.
Scope contingencies of between 15% and 25% are used
in the feasibility study. If changes of scope of
this magnitude are allowed, a total re-evaluation
and subsequent reestimation is in order.
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2-109
The use of scope and
cost estimating. It
from the assumptions
accounting for those
bid contingencies are an accepted part of
is expected that there will be deviations
noted and that contingencies are needed for
unforeseen items.
... mo~ilization and demo~ilization capital costs
are calculated at 8% of the estimated capital
costs....further incinerator demo~ilization costs
of $250,000 are listed. It seems that the
demo~ilization costs are overstated in these
alternatives ~y at least $250,000.
The a-percent demobilization charge is based on installed
capital, which does not include the incinerator. The amortized
cost of the incinerator is included in the operating cost for the
incinerator. Thus, a separate mobilization and demobilization
charge must be added for the incinerators.
...the expected depth of excavation averages 2.18
feet. At that depth, it is expected that the
concentrations of TCDD contamination will ~e 1 ppb
or less.
Independent calculations indicate that'the
excavation area is only 181,300 square yards which
converts to 60,400 c~ic yards at an average d~pth
of excavation of 1 foot. ...if EPA should
nevertheless determine to undertake excavation,
then excavation should only extend to a 1 foot
maximum depth and then ~e backfilled with clean
soil.
Excavation will be undertaken to a level determined by the Agency
based upon recommendations of federal and state health agencies
to represent an acceptable risk. For evaluation purposes, it is
assumed in the feasibility study that the excavation to a depth
of 2 feet is necessary to achieve a 1 ppb residual level,
although the actual depth will vary according to the
contamination that is detected.
cotton coveralls, work gloves, disposable dust
masks, and good hygiene more than adequately
protect personnel performing soil handling
activities.
The level of protection described in the feasibility study is
similar to that used for removal activities at other Missouri
dioxin sites and during work at the Denney Farm incinerator
trials. This level of protection is recommended by appropriate
health agencies to adequately protect personnel.
...level D protective equipment is specified for.
equipment operators in totally enclosed cabs.
...no protection is required if the cab has ~een
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2-110
fitted with the proper filtration system for its
air conditioning/heating co~trols.
since it may be necessary for personnel operating equipment to
leave their equipment or communicate with personnel in the
contaminated zone, Level D protective equipment is considered to
be necessary. This level of protection consists of coveralls and
steel-toed work boots, which is considered to be a reasonable
level of protection of the equipment operators.
Dual responsibilities of remedial personnel address
the areas of decontamination personnel and onsite
safety officers. An onsite, registered nurse is
not merited by the minimal risks of these
activities....remedial activities have successfully.
proceeded without this service.
Onsite nurses have been used during onsite excavation activities
to closely monitor personnel involved in hand labor and wearing
protective gear. Nurses will be used as required to protect
workers. Dual responsibilities will also be used where such use
is considered appropriate.
Additional ~ampling prior to the initiation of
remedial activities at Times Beach is unnecessary.
EPA believes that the data available at the time of
publication of the Times Beach Feasibility Study is insufficient
upon which to design a remedial action. Additional sampling will
be required to determine the extent of contamination prior to
implementation. .
criteria should be established to determine when
dust control would be necessary. Unless needed,
the use of water spray should be discouraged, since
it dramatically increases the labor intensive
nature of the clean-up as well as the ultimate cost
of incinerating this wet soil.
Limited use of water spray as a dust control measure is unlikely
to "dramatically increase" the labor intensive nature of the
cleanup. Dust control will be used as required to prevent
generation of undesirable quantities of fugitive dust during
excavation and handling operations, and to ensure the safety of
site workers and local community.
...guards will not be required after the fence
installation....the first construction activity for
these Alternatives should be the installation of
the fence, then the guards would only be needed for
the first six months maximum...
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2-111
Guards would be used not only to prevent intruders from
contacting contaminated soil, but also to prevent vandalism of
equipment used at the site.
...automatic samp1inq systems are specified for
installation in several drainaqe ditches....two,
and at most three, drainaqe ditches should be
chosen for monitorinq surface run-off.
The precise number of sampling monitors and their locations would
be determined during predesign, design, and the initial phases of
a sampl~ng program.
perimeter air monitorinq is specified. Previous
air monitoring samples have shown no detectable
levels of TCDD miqrating offsite. with no change
in the status of the site, additional air
monitoring is an unnecessary expense...
continuous onsite and offsite ambient air monitoring would be
proyided to assure the safety of ons~te workers and the local
community.
...Level C protective gear is specified for
excavation and Level D protective qear is specified
for construction workers buiidinq the concrete
facility. Such protective equipment is unnecessary
since the construction is proposed within an
uncontaminated area. Typical construction clothinq
is adequate...
The level of protection described in the feasibility study is
similar to that used during removal operations at other Missouri
dioxin sites based upon recommendations of federal and state
health agencies. Level D protection consists of coveralls and
work boots, which is typical for construction sites.
...the size of the water treatment system for
Alternative 4 is to be capable of treatinq a 24
hour, 25 year storm. In addition, a 20% capacity
allowance is added. This capacity is excessive
because:
1. Leachate can be safely stored in the concrete
facility...
2. Excavation will not proceed durinq the storm
event and for several days thereafter...
3. Water in excavated areas should not be
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considered contaminated...
The size of the leachate treatment systems must be sufficient to
protect the land disposal facility. The treatment system must
prevent water from accumulating to the point where the liners or
underdrain system could be damaged. The primary consideration in
the sizing of the system would be the prevention of unacceptable
quantities of rainfall build-up in the storage facility. This
will be particularly critical during excavation operations when
the facility would be open and rainfall could not be prevented
from entering the facility.
~..operating costs can be accurately calculated
(within 20% or less) for a given set of
assumptions. If the assumptions change (most
importantly soil volumes or moisture content), then
the estimates must be recalculated.
The accuracy of the cost estimates presented in the feasibility
study is typical of that required for feasibility studies. The
accuracy is considered to be suitable for decisionmaking. It is
expected that actual site remedial alternatives will vary
somewhat from those described in the feasibility study. More
accurate estimates will be produced during the predesign and
design of the selected remedial alternative.
To make the following statement (Page 8-8,
feasibility study): "It is doubtful that present
or future costs to operate an onsite incinerator
for destroying TCDD from contaminated soil can be
estimated accurately.", conveys the incorrect
impression that incineration techniques and
processes are not well-defined.
Incineration techniques and processes are reasonably well-
defined, but, as the options described by the commentor show,
many variations are possible. In addition, there area large
number of items that would influence the prices offered by an
incineration service company, beyond the techniques and
processes. At the feasibility study level, it is not possible to
forecast precisely the prices charged and approach 'that will be
taken by all the companies that might offer their services on
such a project.
...the $400/cubic yard assumed unit cost for
incineration is excessive and the cost estimates in
the feasibility study should be modified to reflect
this information.
The basis for the $400/cubic yard cost estimate is included with
the detailed costs presented in the feasibility study. This
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cost, which is considered to present the full scope of costs
likely to be encountered by an onsite incineration services
company, is considered to be a reasonable estimate of the changes
required based on the assumptions noted in the text.
...a level area of 28 acres is required for the
incinerator facility. In the Norris Report an area
of only 3.5 acres was specified. Also in the
Norris Report, the entire 3.5 acres was proposed to
be raised above the 100 year flood plain with
offsite borrow for an estimated cost of $575,000.
.
In the feasibility study the ring levee and other necessary site
preparation projects are estimated to cost approximately
$4,000,000 after bid a~d scope contingencies are included.
The precise area required for an incineration facility will
depend strongly on the requirements for storage of excavated
material and ash, as well as the requirements for the incinerator
and access and support facilities. These requirements will be
examined in greater detail during the design phase for the
project. It is doubtful that the entire facilities, including
incinerators and adequate supply of feed material and flood.
protection, can be located within a 3.5-acre area.
...diked tank areas (are noted) for scrubber water
and caust'ic storage tanks. With a dry pollution
control system installed downstream of the
secondary combustion chamber...instead of the wet
scrubbing system specified in the feasibility
study, the $1,500,000 in the feasibility study
estimates can be eliminated.
The specific air pollution control system to be used would depend
on the systems proposed by service companies submitting proposals
on the project. A wet system is assumed, but n6t "specified" by
the feasibility study. A dry scrubbing system may be proposed,
although such a system is presently generally not used by
incineration service companies. Even with such a system, a
quenching operation would be required to reduce the temperature
of gases going to the dry equipment. Such a system would require
the use of caustic.
...the feed storage (or contaminated soil storage)
facility for the incinerator system. A better
system is described in the Norris Report which
provides more storage at reduced costs.
Alternate methods for storage of material would be considered
during the predesign and design phases of the project. It is
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2-114
noted in the feasibility study that systems that differ from
those described conceptually in the report may be used.
cooling water will be needed for the waste heat
boiler but not at the overall water supply rates
noted in the feasibility study.
Cooling water rates may vary from those described in the report.
The rates described in the feasibility study are based on
information from incineration service companies that are actually
involved in site remediation using incineration.
...
Operators of the incinerator should only be
required to observed good hygiene practices since a
~otally enclosed incinerator system can be
specified. operators feeding soil into the
grinding and feed section of the incinerator may
require disposable dust masks and cotton coveralls
in addition to practicing good hygiene.
The level of protection described in the feasibility study is
similar to that used during the Missouri dioxin removal and
incineration activities at the Denney Farm.site. The level of
protection required for the incineration operator will depend, in
part, on the system offered by companies proposing to perform
site incineration services.
Operating efficiencies of 70.8% were assumed. This
would not be acceptable. in an'industrial setting
where an 80%-85% operating efficiencies or higher
are typical.
Operating efficiencies were assumed to be typical of those
encountered after extended operation at sites where onsite
incineration has been performed. The setting assumed for site
remediation is clearly not an industrial setting.
...the capacity of each unit will be 4.25 cubic
yards per hour....this capacity is limited by the
"mobile" restrictions in early comments. This
Capacity could be increased to 5.56 cubic yards per
hour (+30%) with a transportable, modular
unit.
The operating rate used in the feasibility study is based on the
typical size of mobile or transportable incinerators currently in
operation for onsite hazardous waste remediation. It is possible
that a larger incinerator could be constructed and offered by an
incineration service company.
...it is customary to work from March through
November which adds at least two months to the
excavation season. Also, between December and
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February, days will be available which allow
excavation and backfill to proceed. The estimated
project life could be shortened by over 8 months
with these considerations and soil storage
facilities, ring levee, and overall site area for
the incinerator can be reduced in size by 8 times
over the 28 acres proposed in the feasibility
study.
A number of expenses will be incurred while holding an excavation
team on standby during the periods when excavation cannot be
performed. Since the actual project life is determined primarily
by the operating rate of the incinerator, the project life would
not be significantly affected by a different excavation schedule.
Factors such as these would be evaluated during predesign and
design of the selected alternative.
The material which has already been placed in
bags will create significant and costly handling
difficulties in their re~oval from their storage
barns, moving them to any incinerator, and
handling them at any incinerator. The bags will
also require another disposal alternative since
they cannot be easily incinerated.
Handling of the existing material will not present undue handling.
difficulties. These containers can be handled with conventional
handling equipment, as they have in the past. It has been
demonstrated at the Denney Farm site that these containers can be
incinerated.
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SECTION ~
FEASIBILITY STUDY OF FINAL REMEDIAL ACTIONS FOR THE
KINKER/STOUT/ROMAINE CREEK SITE
INTRODUCTION
In July, 1986, the U.S. Environmental Protection Agency released
a study entitled Feasibility studY of Final Remedial Actions for
the Minker/Stout/Romaine Creek Site for public review. This
study evaluated remedial alternatives for final management of
diqxin-contaminated soil at all portions of the
Minker/Stout/Romaine Creek site, including the Sullins and C~shel
properties". A public comment period was held from August 8, 1986
through September 5~ 1986, and included a public meeting
conducted August 25, 1986 to discuss the study.
This responsiveness summary presents the Agency's response to
public comments received by the Office of Public Affairs,
Environmental Protection Agency, Region VII, Kansas City, Kansas,
concerning the Feasibility StudY of Final Remedial Actions for
the Minker/Stout/Romaine Creek site. This responsiveness summary
constitutes a component of the record of decision which documents
the remedial action selection.
This Responsiveness Summary documents for the public record:
Concerns and issues raised during the August 25, 1985 public
meeting concerning the Minker/Stout/Romaine Creek site.
written comments received during the public comment period" for
the Feasibility StudY of Final Remedial Actions for the
Minker/Stout/Romaine Creek site.
How EPA has considered and responded to these comments in
selecting a final management alternative for the dioxin-
contaminated material at the site.
The comments are grouped into several categories, according to
the topic that they address. The topics include comments
received during the public meeting, procedural comments, comments
regarding the schedule for the decision-making process, comments
regarding the tentatively selected alternative or alternatives
not selected, and technical questions and comments. This
responsiveness summary is organized according to these
categories.
COMMENTS RECEIVED DURING THE PUBLIC KEETING
At the public meeting, there were several questions regarding the
cleanup and the proposed alternative.
-------
EPA was asked if the incinerator currently in
southwest Missouri would be used to thermally
the soil from the Minker/stout/Romaine Creek
(M/S/RC) site. .
treat
The EPA mobile incinerator in southwest Missouri is a research
unit. This incinerator has been issued a research permit for
treatment of specific material, which does not include dioxin-
contaminated soil from the M/S/RC site. Therefore, the EPA
mobile incinerator is not currently available for the treatment
of this material. .
The unit in southwest Missouri will not. be considered for
treatment of material from the M/S/RC site due to its limited
capacity which would result in ~n excessive cost and period of
time required to treat all of the material from the site.
EPA was asked why they were proposing offsite
thermal treatment when no such capacity currently
exists.
With the exception of the EPA mobile incinerator located in
southwest Missouri, no thermal treatment unit has been issued a
permit by EPA to treat dioxin wastes. Although there are
currently no permitted thermal treatment units available for
~t~eatment of the contaminated soil frpm the M/S/RC site, several
companies have such equipment or the capability of constructing
such a device. Several firms operate transportable thermal
treatment units which .can be assembled at an offsite location and
designed to handle the soil and other contaminated materials from
the M/S/RC site. EPA anticipates that a number of qualified
bidders will respond to a request for proposals (RFP) for offsite
thermal treatment of the dioxin-contaminated material from this
site.
A question was asked regarding the availability of
funding to. carry out the cleanup.
The proposed remedy would be carried out using funds generated by
the Comprehensive Environmental Response, Compensation, and
Liability Act of 1980 (CERCLA), as amended by the Superfund
Amendments and Reauthorization Act of 1986 (SARA). This Act
establishes a trust fund to finance response actions at
uncontrolled or abandoned hazardous waste sites (Superfund).
Sufficient funds are available in this fund to implement the
proposed remedy.
Ninety percent of the cost of the project would be funded by
Superfund. The State would be required to provide a 10 percent
cost share for the project. The State has indicated their
ability to generate the necessary funds, should this remedy be
selected.
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3-3
EPA was asked how much the offsite thermal
treatment alternative will cost.
The Feasibility study of Final Remedial Actions at the
Minker/Stout/Romaine Creek site includes what is referred to as
an order of magnitude cost estimate. Such estimates are expected
to be accurate to within +50 percent and ~30 percent. The cost
estimate presented in the feasibility study for offsite
incineration of 20,000 cubic yards of contaminated soil
$25,000,000. Thus, the actual cost is expected to fall
$17,500,000 and $37,500,000. Uncertainties involved in
the estimate result in the range of values.
Since the feasibility study was released in 1986, . the Agency has
gained information which enables a more accurate cost estimate to
be prepared. The best information available to the Agency
'indicates that the unit cost for operation of a thermal treatment
unit is expected to be approximately $400 per cubic yard, as
compared to $700 per cubic yard presented in the 1986 feasibility
study. The total volume of soil to be treated from the M/S/RC
site is currently estimated at 12,000 cubic yards, compared to
the feasibility study estimate of 20,000 cubic yards. This
results in a reduction of the estimated cost of offsite thermal
treatment for the material from the M/S/RC site to approximately
$15 million. .
is
between
making
Onc~ the remedy is selected, a detailed design of the alternative
will be developed. At that time, it will be possible to prepare
a much more precise estimate of the final cost.
One commentor noted that a previous proposal to
locate a central facility at Times Beach had not
been received favorably. EPA was asked if similar
opposition was expected for the proposal to locate
a thermal treatment unit at Times Beach.
In 1984, a Record of Decision was signed for construction of an
Interim Central Storage Facility (ICSF) at Times Beach. This
unit was designed to store dioxin-contaminated soils from the
nearby Castlewood, Quail Run, and Minker/Stout/Romaine Creek
sites. The project did not involve management of contaminated
soil or structures and debris from Times Beach.
A primary reason that the public was opposed to this project at
that time was because no final management capacity for the stored
soils was identified. Nearby residents were concerned that the
soil would remain in storage for an indefinite period of time in
the absence of such a final management alternative. The
surrounding community expressed opposition to the permanent
management of hazardous materials at Times Beach. In addition,
the proposed ICSF did not address contaminated soils or the
deteriorating structures and debris at Times Beach. Management
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3-4
of offsitesoils did not benefit the nearby community.
EPA believes. that a thermal treatment unit will be received more
favorably than the previous proposal to build a storage facility
at Times Beach. Thermal treatment at Times Beach would represent
a final remedy for contaminated soils located at both M/S/RC and
Times Beach, rather than an interim step involving the potential
long-term management of hazardous materials. Once the dioxin is
destroyed by thermal treatment and delisted, the soil would no
longer be hazardous, and the threat to public health and the
environment would be eliminated. Following thermal treatment,
the unit would be dismantled and removed, leaving Times Beach
free of any hazardous waste management activity.
The proposed remedy at Times Beach also involves final management
ot the deteriorating structures and debris at Times Beach, which
has been another primary concern of the nearby community.
The south outer road to Interstate 44, which provides alternate
access to the adjacent city of Eureka, has been closed since
implementation of the permanent relocation in 1983. This has
resulted in an increase in traffic congestion at the Eureka
interchange. Following completion of the proposed remedial
action at Times Beach, reopening of the south outer road would be
possible. This action is strongly supported by the residents of
Eureka.
EPA was asked whether or not other sites, besides
Times Beach, are being considered for thermal
treatment of contaminated materials from the M/S/RC
site.
Times Beach is the only location which has been identified by the
state and EPA that is suitable for implementation of the proposed
remedy. No other sites are actively being reviewed at this time.
EPA and the state will evaluate other feasible sites to locate
the unit, if recommended. .
The state was asked whether or not the property
deeds of the houses at the M/S/RC site would always
include a notation that the property had once been
contaminated.
Deed restrictions are implemented by the state. state law
requires that the notation always remain on the property records.
However, once the property is cleaned up, and the Department of
Health certifies the cleanup, the property records "are updated to
indicate that the property is once again safe for habitation and
unrestricted use.
EPA was asked why the option of a buyout was not
addressed in the feasibility study.
The issue of public health risk and the need for permanent
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3-5
relocation was addressed in 1983 immediately following the
discovery of dioxin contamination at the site. Those residents
determined to be at risk have been provided either temporary or
permanent relocation, as appropriate.
A question was asked regarding the schedule tor
removing the contaminated soil currently in
temporary storage at the Kinker area.
The Feasibilitv StudY of Final Remedial Actions for the
Minker/Stout/Romaine Creek site includes a schedule for the
preferred alternative which indicates that the entire operation
should require less than 5 years from project initiation, with
all of the soil removed from the site in slightly more than 4
years. If the proposed remedy is selected in a Record of
Decision, EPA is confident that this schedule is reasonable and
can be met.
EPA was asked whether a mitigation plan was
prepared tor the work that was underway a tew days
preceding the August 25, 1986 public meeting.
A mitigation plan was prepared for the removal action which
commenced at the Abrahamson and Payne properties. prior to the
meeting. As explained at the public meeting, this mitigation
plan was available prior to and during th~ removal action at the
EPA Public Information Center located at the Minker portion of
the site. .
EPA was asked whether or not it had actually been
demonstrated that the soil from the site could be
incinerated and also if incineration would be
feasible for asphalt and concrete.
The incineration demonstration that EPA has carried out. in
southwest Missouri has successfully demonstrated that thermal
treatment is capable of destroying dioxin in soil to undetectable
levels. No dioxin contamination has been detected in the residue
(ash) or any emissions from the unit. The destruction and removal
efficiency is high enough to meet permit requirements under the
Resource Conservation and Recovery Act, as amended (RCRA).
Residue from the process has been successfully delisted and
disposed of as a solid waste. Thus, EPA has demonstrated that
the dioxin contamination in Missouri soils can be safely
destroyed by incineration. .
The incinerator-in southwest Missouri is capable of processing
concrete and asphalt. The thermal treatment unit that is
proposed to treat the soil from the M/S/RC site will also be able
to process asphalt and concrete. However, steam cleaning has
been demonstrated to be an effective means of decontaminating
concrete, and is likely to be more cost-effective than thermal
treatment.
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3-5
relocation was addressed in 1983 immediately following the
discovery of dioxin contamination at the site. Those residents
determined to be at risk have been provided either temporary or
permanent relocation, as appropriate.
A question was asked regarding the schedule for
removing the contaminated soil currently in
temporary storage at the Kinker area.
The Feasibility StudY of Final Remedial Actions for the
Minker/Stout/Romaine Creek Site includes a schedu~e for the
preferred alternative which indicates that the entire operation
should require less than 5 years from project initiation, with
all of the soil removed from the site in slightly more than 4
years. If the proposed remedy is selected in a Record of
Decision, EPA is confident that this schedule is reasonable and
can be met.
EPA was asked whether a mitigation plan was
prepared for the work that was underway a few days
preceding the August 25, 1986 public meeting.
A mitigation plan was prepared for the removal action which
commenced at the Abrahamson and Payne properties prior to the
meeting. As explained at the public meeting, this mitigation
plan was available prior to and during the'removal action at the
.EPA Public Information Center located at the Minker portion of
the. site.
EPA was asked whether or not it had actually been
demonstrated that the soil from the site could be
incinerated and also if incineration would be
feasible for asphalt and concrete.
The incineration demonstration that EPA has carried out in
southwest Missouri has successfully demonstrated that thermal
treatment is capable of destroying dioxin in soil to undetectable
levels. No dioxin contamination has been detected in the residue
(ash) or any emissions from the unit. The destruction and removal
efficiency is high enough to meet permit requirements under the
Resource Conservation and Recovery Act, as amended (RCRA).
Residue from the process has been successfully delisted and
disposed of as a solid waste. Thus, EPA has demonstrated that
the dioxin contamination in Missouri soils can be safely
destroyed by incineration.
The incinerator in southwest Missouri is capable of processing
concrete and asphalt. The thermal treatment unit that is
proposed to treat the soil from the MjSjRC site will also be able
to process asphalt and concrete. However, steam cleaning has
been demonstrated to be an effective means of decontaminating
concrete, and is likely to be more cost-effective than thermal
treatment.
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3-6
A question was asked regarding the amount of time
that the EPA incinerator has been out of service
during the demonstration in southwest Missouri.
The EPA incinerator is a research unit, originally intended for
handling liquids, and not designed to handle large volumes of
soil efficiently. EPA experienced some initial difficulties in
the operation of the incinerator, resulting
time for maintenance. However, as noted in
response, the incinerator was successful at
soils to undetectable levels.
in considerable down-
the previous
destroying dioxin in
The EPA mobile in~inerator has been retrofitted with better"
materials handling equipment, which has enabled processing
several times the amount of soil per hour that it was initially
capable of, and has significantly reduced the amount of down-time
required for maintenance.
A question was asked about the capacity of the EPA
mobile incinerator.
As noted in a previous response, the capacity of the mobile
incinerator is limited by its original. design and purpose.
new unit that would be built to treat the soil from the
Minker/Stout/Romaine Creek site would be capable of handling
larger volumes of soil than the incinerator EPA is currently
operating.
The"
A question was asked regarding the disposal of the
residue from the thermal treatment process.
RCRA designates lists of specific hazardous wastes which are
regulated by EPA under RCRA authority. Residue from the thermal
treatment of dioxin-contaminated soil at the M/S/RC site is
listed as a hazardous waste under RCRA, and subject to the
requirements for the management of a hazardous waste. If it can
be determined that the residue is free of the hazardous
constituents or characteristics for which it was considered a
hazardous waste, the residue can be disposed of as a non-
hazardous solid waste. This determination is referred to as a
delisting procedure. The residue from the EPA mobile incinerator
has been demonstrated to meet delisting criteria and has been
delisted as a hazardous waste. EPA believes that the residue
from thermal treatment of the soil from the M/S/RC site can be
delisted and disposed of as a solid waste.
The proposed method of disposal of residue from the thermal
treatment unit is onsite disposal in a unit or units designed and
constructed to meet solid waste management requirements. Another
option would be to transport the ash to an offsite solid waste
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3-7
landfill for disposal. This option results in the use of
valuable space in a sanitary landfill. The cost of
transportation and the fee for disposal is likely to make
disposal less cost-effective. Therefore, onsite disposal
residue is the preferred alternative.
offsite
of the
A question vas asked regarding the disposition of
the houses that are currently unoccupied at the
M/S/RC site.
The houses at the site have been restored, following removal and
storage of contaminated soil, to a safe, habitable condition. .
The titles to the houses were transferred to the state following
the permanent relocation. Following removal of the contaminated
soil currently in storage from the site, the temporary storage
structures will be dismantled and removed. The houses can then
be sold, and revenue generated from the sale returned to
Superfund for future cleanups at other sites. Sale of the homes
has the advantage of returning the neighborhood to the level of
housing density that existed before the contamination was
discovered, and thus completes the restoration of the area to its
original condition.
EPA was asked about the volume of soil to be
removed from the Kinker/Stout/Romaine Creek site.
Removal actions have been completed at the Sullins, Cashel, and
Minker portions of the M/S/RC site. A total of 5~800 cubic yards
of soil was excavated from these areas and placed in interim
onsite storage at the Minker area. The two remaining portions of
the site to be cleaned up include the stout area and Romaine
Creek. These cleanups are scheduled to be completed in the 1988
construction season. It is estimated that 1,900 cubic yards of
soil will be removed at the stout area, and 4,300 cubic yards of
soil and sediment from Romaine Creek will be removed to meet
cleanup criteria.
EPA believes that these soil volume projections are as accurate
as possible prior to actually performing the soil removal. The
lateral extent of contamination at the stout area has been
determined using a statistical sampling procedure which
determines average dioxin concentrations to the 95 percentile
upper confidence level. This sampling procedure is identical to
the procedure which is used during the actual removal of
contaminated soil.
The soil and sediment volume requiring removal from Romaine Creek
is also known with a high degree of confidence. Dioxin
contamination has been detected in the upper 6,000 feet of
Romaine Creek. During preparation of the Romaine Creek Operable
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3-8
unit Feasibilitv Study stream sediment profiles were determined
at intervals ranging from 100 to 300 feet in the upper 6000 feet
of Romaine Creek. In a subsequent investigation, areas of
sediment deposition were targeted for sediment depth m~asurements
along the entire length of Romaine Creek. This information has
enabled an accurate estimate of the contaminated soil and
sediment volume to be prepared.
An estimated soil volume of 20,000 cubic yards was assumed in the
feasibility study for the purpose of costing and comparing
remedial alternatives. This estimate was prepared prior to the
availability of statistical sampling data at the stout area, .
sediment volume measurements at Romaine Creek, or completion of
the. removal action at the Minker area. The feasibility study
evaluation process allows for a valid comparison of alternatives
for a range of contaminated soil volumes. EPA believes that the
volume of soil assumed in the feasibility study is a reasonably
accurate volume upon which to base a remedy selection. In addi-
tion, the cost evaluation of the preferred alternative has been
further developed in the Proposed Plan for Final Manaqement of
Dioxin-contaminated Soil and Final Disposition of Structures and
Debris at Times Beach. Missouri. and the Minker/Stout/Romaine
Creek Site. Missouri (Proposed Plan). The actual cost of the
remedy will depend on industry conditions when the contract is
competitively ~warded.
EPA was asked a question about the level of site
restoration that is intended for the site. .
specifically, whether or not everything would
be restored to its original condition or, if
necessary, replaced. .
To the degree possible, everything at the site will be restored
to .its original condition following completion of response
actions at the site. In cases where restoration to the original
condition is not possible, or not cost-effective, items will be
replaced with equivalent new items.
WRITTEN COMMENTS
PROCEDURAL
One commentor stated that EPA had not followed the
requirements of the National contingency Plan
because it had not solicited or evaluated comments
on the soil excavation and storage activities that
have already been implemented.
The excavations at the Sullins, Cashel, Abrahamson, and Payne
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3-9
properties were carried out under EPA's "removal" authority under
the National Contingency Plan. The National Contingency Plan
does not require a public comment period prior to implementation
of removal actions. Nevertheless, mitigation plans describing
these removal actions were made available to the public prior to
implementation. EPA has not failed to follow proper procedures
in carrying out these removal activities. (The actions discussed
in the feasibility study and Proposed Plan are to be carried out
under the "remedial" authority. The National Ccintingency Plan
. does require a public comment period for remedial actions.)
,
One commentor stated that SPA has not met the
National contingency Plan requirement that remedial
actions should be cost-effective because interim
. storage in the flexible containers is a more
expensive approach than bulk handling. The
commentor suggests that the soil should be left in
place and excavated only when the thermal treatment
unit is ready to receive it, and then that it
be moved by bulk transport.
EPA has considered allowing the contaminated soil to remain in
place until final management capacity is available. Although it
is initially more expensive to containerize the contaminated soil
than to ~andle in bulk, .EPA .believes that the container storage
option that it has been implementing is part of a cost-effective.
overall remedy which assures the short-term and long-term
protection of public health and the environmeht.
If contaminated soil is allowed to remain in place, exposure to
dioxin would continue to occur above a level of concern for
protection of human health. Environmental exposure would also
continue at an unacceptable level. Containment of the contam-
inated soil substantially reduces the potential for exposure,
providing a high degree of short-term protection of public health
and the environment. Soil containment also provides greater
protection to workers during future soil-handling activities.
In addition to the continued exposure, the contaminated soil
could continue to erode and migrate from the site. This results
in the expansion of site boundaries and increases the amount of
soil that will eventually have to be excavated, transported, and
managed. These additional costs must be included in comparing.
immediate with delayed excavation. EPA has determined that
excavating the soil now will reduce the total overall cost of the
remedy.
One commentor stated that the No-Action alternative
should have been given more consideration. The
basis for this contention is that recent
assessments of the risks presented by dioxin
contamination do not support a need to clean up
sites to the one part per billion level, and that
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it might therefore be reasonable tor the
contamination to remain in-place.
As noted in a previous response, EPA believes that uncontrolled
contamination at the M/S/RC site represents an unacceptable risk
to public health and tt.e environment. Removal actions involving
the excavation and onsite interim storage of contaminated soil
have been performed at the Sullins, Cashel, and Minker portions
of the site. EPA determined, 'on the basis of advice from the
Centers for Disease Control (CDC), that these actions were
necessary to protect human health and the environment in
residential settings such as the M/S/RC site. EPA has assessed
the threat posed by dioxin contamination at the stout and Romaine
Creek portions of the site, and has determined that response is
necessary to achieve protectiveness. . ,
It should be pointed out that the no-action alternative in the
feasibility study is not an alternative to leave the contaminated
soil in place. The feasibility study is based on an assumption
that the contaminated soil has, or will be, excavated and placed
in interim storage. The no-action alternative in the feasibility
study involves leaving the excavated soil in the temporary
storage structures. The storage structures are not designed for
permanent management of the contaminated ,soil. ' An unacceptable
risk of future contaminant release would result if the temporary
storage structures were used for permanent disposal. Therefore,
the no-action alternative was found to be unacceptable.
SCHEDULE
One commentor stated that it would be inappropriate
to develop and sign a Record of Decision tor the
Minker/stout/Romaine Creek site until the location
for the thermal treatment unit is established.
In the Proposed Plan, EPA has identified Times Beach as the
preferred location for the thermal treatment unit that would be
used to treat dioxin-contaminated material from the M/S/RC site.
If the preferred remedy is selected, the Record of Decision for
M/S/RC and Times Beach will establish Times Beach as the location
for offsite thermal treatment of contaminated soils at the M/S/RC
site.
Three advantages of delaying a decision for final
management of dioxin-contaminated material at the
the M/S/RC site were suggested: (1) Delay would
provide time for further development and
analysis of chemical and biodegradation
technologies as well as development and
demonstration of additional thermal treatment
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technologies: (2) No adverse consequences
would result from delay, since the storage,
buildings are designed to last for several years:
an~ (3) More precise estimates of the costs of
incineration will be possible.
EPA has postponed a final management decision for more than five
years, including approximately one and one-half years since
public release of the Feasibilitv Study of Final Remedial Actions
for the Minker/Stout/Romaine Creek site. During this time, EPA
has studied the development of alternative technologies and has
funded research efforts to analyze alternative technologies as a
part of the National Dioxin strategy and SITE (Superfund
Innovative Technology Evaluation) program. To date, thermal
treatment is the only 'alternative technology that has
demonstrated, on a large scale, removal efficiencies for dioxin
in soil which enable delisting and achieve protectiveness.
In the last few years, several thermal treatment technologies
have been sufficiently developed that they could potentially be
applied'to the contaminated soils at the M/S/RC site.. EPA
believes that the competitive bidding process will allow the most
cost-effective thermal treatment technology to be selected for
the project. EPA does not believe that new thermal treatment
technologies will be developed in the near future which will be
more cost-effective than the technologies curren~ly available.
EPA has made a commitment to remove this soil as expeditiously as
possible, within 10 years at the l~test. Given the lead times'
required to establish and permit a ~treatment unit, EPA believes
that it is necessary to make a decision at this time and to begin
work on implementing the solution.
Information regarding the cost of thermal treatment has greatly
improved since the release of the feasibility study due to
experience with treatment of hazardous materials both within and
outside the Agency. EPA believes that the technology has been
developed and demonstrated to the degree necessary to prepare
accurate cost projections. The actual cost to thermally treat the
soil will be determined by industry and market conditions at the
time that a contract is awarded for the work.
ALTERNATIVE SELECTED
Several comments either addressed the alternative EPA has
tentatively selected or recommended that EPA consider or choose a
different alternative.,
Two comments supported the offsite thermal
treatment alternative and the proposal of the state
to locate a thermal treatment unit in Times Beach
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as a logical choice.
As indicated in the Proposed Plan, EPA is proposing to use Times
Beach as the site for a temporary thermal treatment unit.
One comment suggested that EPA let the sun destroy
the dioxin. The suggestion is based on evidence
that dioxin on soil can be destroyed by the action
of sunlight.
EPA has evaluated the evidence that sunlight destroys dioxin on
contaminated soil at sites in Missouri and finds .that there is
much stronger evidence that the process of destruction, if it
occurs at all, is too slow and much too inefficient to take
advantage of in cleaning 'up contaminated sites.
Some of the most compelling evidence comes from EPA's own
sampling efforts in Missouri. At the Castlewood site as an
example, there was contamination at very shallow depths,
including contaminated dust on the surface of paved roads, that
had not been destroyed by the sun over a period of several years.
EPA sampled extensively along the roadways in the Castlewood
area, and detected dioxin contamination up to 60 parts per
billion at the surface. EPA believes this demonstrates that the
action of sunlight is either insufficient or too slow to be
utilized as an in-situ ~ethod to decontaminate sites.
EPA has responde~ to this sugg~stion at greater length in a
letter to the person making the comment at the public meeting.
One commentor stated that EPA should not eliminate
the mine storage alternative only due to the lack
of permitting standards tor this type ot a
tacility. The commentor recommended that EPA
select mine storage as the remedy because thermal
treatment would be more expensive, less protective
ot human health, and no more protective ot the
environment.
As discussed in the feasibility study, thermal treatment of
contaminated soils provides a higher degree of long-term
protection of human health and the environment than mine
disposal. Thermal treatment eliminates the potential for future
exposure to the treated material. There is a risk of future
release from any type of land disposal unit, including
underground mines. Catastrophic failure of a mine used for
storage of contaminated material could result in a tremendous
additional cost to control potential release of contaminants into
the environment.
There are short-term risks associated with thermal treatment
including the potential for airborne release of products of
incomplete combustion (PICs). These risks can be controlled by
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proper operating conditions, air pollution control equipment, and
safety devices. There are short-term risks associated with both
treatment and mine disposal during transport of contaminated
material over public roadways and associated soil handling
activities.
EPA is required to select the most cost-effective remedial
alternative, not simply the lowest cost. The additional benefit
that thermal treatment offers, i.e. permanent destruction of the
contamination, justifies the additional expense. No other
alternative offers this degree of short- and long-term protection
of human health and the environment at a lower cost. Thermal
treatment is therefore the most cost-effective alternative.
EPA is required to select a remedial alternative which attains
all applicable or relevant and appropriate requirements for the
protection of human health and the environment. The Resource
Conservation and Recovery Act of 1976, as amended (RCRA) is
applicable to. the disposal of dioxin-contaminated soil from the
M/S/RC site in underground mines. The implementing regulations
of RCRA specifically state that dioxin waste can not be disposed
of in underground mines prior to the development of appropriate
regulations. An exemption from this regulatiQn under SARA has
not been identified. EPA therefore can not select disposal in
underground mines for the .dioxin-contaminated soil at the M/S/RC
site.
One commentor suggested that EPA should develop an
integrated solution tor allot the dioxin sites in
eastern Missouri. It analyzed in this way, a more
efficient thermal treatment unit could be
justified, which would substantially reduce overall
costs.
The Times Beach Feasibilitv Study evaluated locating a temporary
thermal treatment unit at Times Beach that would be used to
decontaminate the soil from Times Beach and three other
identified sites, including Castlewood, Quail Run, and the M/S/RC
site. The Proposed Plan has expanded this concept to include a
total of 26 identified potential sites for centralized thermal
treatment at Times Beach. A single centralized facility is more
cost-effective than many individual onsite units since multiple
one-time costs are eliminated (mobilization, demobilization,
etc.), and economies of scale result from design of a larger unit
capable of treating large quantities of soil more efficiently.
Technical
EPA received many comments that addressed technical issues or
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questions.
One comment suggested that EPA undertake a much
larger sampling effort in order to establish the
exact areal and vertical extent of the
contamination. This, the commentor stated, would
allow BPA to establish beforehand the depth to
which each area of the site would be excavated and
enable EPA to excavate the proper amount of soil in
a single pass. The commentor suggested that this
would be more efficient than the iterative
excavation and sampling method EPA has been using
because it would not involve long delays during
excavation while waiting for results of the
sampling.
The Feasibilitv studY of Final Remedial Actions for the
Minker/Stout/Romaine Creek site does not address the procedure
used for excavation of contaminated soil. The feasibility study
assumes that the contaminated soil from the site has been
previously excavated and placed in interim onsite storage. A
discussion of the excavation procedure follows, although the
comment is not included in the scope of ~his responsiveness
summary.
The excavation procedure currently utilized by EPA during removal
of contaminated soil is cost-effective and necessary to provide
assurance that cleanup criteria are being achieved, while
minimizing the amount of soil that is excavated. EPA Region VII
has gained considerable experience with soil sampling during
investigation of the Missouri dioxin sites. A number of studies
have been performed to compare the reliability of various
sampling techniques. EPA has determined that special sample
collection procedures involving trenching and lateral sampling
are required in order to obtain representative soil samples at
depth below the surface for dioxin analysis in the parts per
billion range. Trenching and lateral sampling are required due
to contamination of the sample which occurs from more highly
contaminated soil at shallower depths using conventional sampling
procedures. Trenching and lateral sampling is very labor-
intensive and costly relative to the collection of samples from
the surface using conventional methods.
The sampling protocol which is currently utilized during the
removal of dioxin-contaminated sites in Missouri was developed by
EPA and other state and federal agencies involved, including the
Centers for Disease Control, Missouri Department of Natural
Resources, and Missouri Division of Health. The cleanup criteria
established by these health agencies is based upon determination
of dioxin concentrations using this procedure. This sampling
protocol determines the average dioxin concentration within
individual cleanup sections at a site to the 95% upper confidence
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level, and requires the collection of individual soil samples
from at least 150 locations within each 5,000 square foot portion
of a site. This sampling is performed prior to excavation and
defines the areal extent of contamination.
In consideration of the number of samples that are, required to
determine if cleanup criteria are achieved, it is more cost-
effective to determine dioxin concentrations at the surface,
excavate, and resample, than to attempt to define the vertical
extent of contamination prior to excavation using the labor-
intensive trenching method. If a single-pass approach to
excavation was employed, as suggested by the commentor, the sam~
degree of verification sampling performed following excavation
would still be required to determine if cleanup criteria are met.
The only cost savings resulting from a single-pass approach would
be a reduced likelihood that additional excavation would be
required to meet cleanup criteria. This cost savings would be
surpassed by the increased cost for the initial determination of
the vertical extent of contamination.
The sampling and excavation procedure currently employed by EPA
is designed to minimize the number of sampling/excavation
iterations which are necessary to achieve cleanup criteria. This
is done by recognizing the correlation between the initial
surface concentration and the required depth o~ excavation. The
initial depth of soil excavated in each cleanup section 'is
adjusted according to the surface concentration determined prior
to excavation. ", .
In addition, the excavation crew is not delayed while awaiting
sampling results. The site is divided into sections which are
excavated and sampled independently. While waiting for ana-
lytical results from one section, excavation proceeds on other
sections. Analytical results are available within 24 hours of
submitting the samples to the laboratory.
A question was asked regarding the estimate of
20,000 cubic yards for the amount of soil to be
excavated. The commentor was concerned that the
figure might be much higher than necessary.
As noted in response to a question at the public meeting, there
is uncertainty in the volume of contaminated soil at a site until
soil removal has been completed. The estimate of 20,000 cubic
yards in the feasibility study represents an upper-bound estimate
which was derived to make it possible to compare costs of
alternatives. The estimate was sufficiently accurate, on the
basis of the data available at the time of preparation of the
feasibility study, to allow a valid comparison of alternatives.
since the completion of the feasibility study, the removal of
soil at the Minker area has been completed, and additional
sampling has been performed at the Romaine Creek and stout
portions of the site. The current estimate for the total volume
of dioxin-contaminated material at all portions of the site is
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12,000 cubic yards. EPA believes that the comparison of
alternatives performed in the feasibility study is valid for this
contaminated soil volume. EPA has updated the cost estimate for
offsite thermal treatment in consideration of this revised soil
volume estimate and other experience gained since preparation of
the feasibility study. This evaluation is presented in the
Proposed Plan. .
One commentor agreed that thermal treatment
represents a permanent and technically feasible
alternative, but took exception to some assumptions
in the study regarding the various
incineration al ternati ves. Specifically,. an
offsite indirect-fired thermal treatment unit vas
recommended as more cost-effective due to the
smaller gas handling equipment required and lover
fuel consumptione
The Proposed Plan identifies thermal treatment as a component of
the preferred alternative. Thermal treatment represents a number
of related technologies, including incineration. Rotary kiln
incineration was assumed in the feasibility study for the purpose
of evaluating costs, due to the amount of information regarding
this particular technology which is available in the literature,
and industry and agency experience with it use.
The type of ' thermal treatment to be implemented is not specified
in the Proposed Plan, and will not be selected in the Record of
Decision. EPA expects to advertise performance-based bid
specifications to provide thermal treatment services for the
contaminated materials. EPA will specify performance
requirements which must be met by the thermal treatment unit.
It will be the responsibility of each bidder to determine the
particular type of thermal treatment technology to propose. If
indirect-fired incineration offers a substantial cost savings
over other types of thermal treatment, EPA would expect one or
more bids to propose the use of such a unit.
It has been the Agency's experience that the cost of labor
represents the primary cost of thermal treatment. Energy costs
comprise a smaller portion of the total cost of operating an
incinerator. If this holds true for other types of thermal
treatment units, the energy cost savings of indirect-fired
thermal treatment might not represent a significant fraction of
the total costs.
One commentor questioned the appropriateness of the
one part per billion cleanup level in consideration
of recent improvements in the exposure and risk
estimating methods used for assessing the potential
health effects of dioxine The commentor recommends
that EPA reassess. the exposure assumptions and
health risk factors used in the previous risk
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assessments.
The cleanup level is not an issue in this feasibility study.
This study and the decision process that EPA is initiating,
assumes that the contaminated soil has been excavated and placed
in storage. An explanation of the cleanup levels established for
the site is provided, although this issue is not included in the
scope of the feasibility study or this responsiveness summary.
As explained in the Proposed Plan, a paper was published in 1984
by Renate D. Kimbrough, M.D., et al., of the Center for
Environmental Health, Centers for Disease control, which
evaluated acceptable concentrations of dioxin in soil for
residential settings. A risk assessment was performed in this
paper which concluded that dioxin concentratio~s exceeding 1 part
per billion (ppb) in residential soils pose a level of concern
for human health. This recommendation has formed the basis for
the criterion of 1 ppb which has been applied during the cleanup
of all residential sites in Missouri, to date, including the
M/S/RC site. The Centers for Disease Control has recently
affirmed that the risk assessment presented in the 1984 paper
remains valid in consideration of all scientific evidence
currently available.
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