United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R05-92/193
April 1992
Superfund
Record of Decision:
Midco II (Amendment), IN
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NOTICE
The appendices listed in the index that are not found in this document have been removed at the request of
the issuing agency. They contain material which supplement, but adds no further applicable information to
the content of the document. All supplemental material is, however, contained in the administrative record
for this site.
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REPORT DOCUMENTATION 11. REPORT NO. 1 ~ 3. ReclpIenI'8 AccessIon No.
PAGE EPA/ROD/R05-92/193
4. 'TIlle and SUb1I1Ie 5. Report Dale
SUPERFUND RECORD OF DECISION 04/13/92
Midco II (Amendment), IN 6.
First Remedial Action - Amendment
7. AulhCr(s) 8. PBrronnJng Organlmtlon Rept. No.
9. Perfonnlng ()rgaInIzaIIon N8ne 8Id Addre8S 10. ProjecfIT8IIkIWortc: ~ No.
11. ContnIr:t(C) or GnInt(G) No.
(C)
(G)
12. SponsorIng Orgllllldon Name and Addr88S 13. Type of Report & Pertod Covered
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
Washington, D.C. 20460 14.
15. su,..Aoo\OOWy No1Ds
PB93-964102
16. Ab8trIICt (LImII: 200 wordS)
The 7-acre Midco II site is an abandoned chemical waste storage and disposal facili ty
in Gary, Indiana. Land use in the surrounding area is predominantly industrial. The
underlying aquifer, which is used primarily for non-drinking purposes, is highly
susceptible to contamination from surface sources. From 1976 to 1978, this site was
used for treatment, storage, and disposal of chemical and bulk liquid wastes. Onsite
pits were used for disposal, from which wastes percolated into and contaminated the
ground water. An overflow pipe from a filter bed disposal pit discharged directly
into a ditch draining directly into the nearby Grand Calumet River. Addi tionally, an
estimated 10 waste storage tanks were deteriorated and leaking. In 1977, a fire at
the site destroyed an estimated 50,000 to 60,000 waste drums. In 1981, EPA installed
a fence around the site. From 1984 to 1989, EPA removed all surface wastes, including
thousands of drums and numerous tanks of chemical waste; excavated and disposed
off site subsurface soils and wastes from the sludge pits and the filter bed; and
extended the site fence. This ROD amends a 1989 ROD that addressed the remaining
contaminated soil, pit wastes, and ground water by treatment of an estimated
35,000 cubic yards of soil wastes using solidification/stabilization followed by
(See Attached Page)
17. Doc:un8It AnalysIs a DescrIptor8
Record of Decision - Midco II (Amendment), IN
First Remedial Action - Amendment
Contaminated Media: soil, sediment, gw
Key Contaminants: VOCs (benzene, toluene, TCE, xylene), other organics (PCBs,
phenols, PAHs), metals (arsenic, chromium, lead)
b. Iden1IIIerSfOpe Terms
c. COSATI RelclfGroup
18. AVIIIJabIIIty SIBb!ment 19. securtty Class (TbIs Report) 21. No. of Pages
None 71
20. SecuItty Class (1bIs Page) ~ PItce
None
50272-101
(See AtSo239.18)
See /n8f1UctIons on Rev-
OPTIONAL FORM 272 (4-77)
(Formerly NTl5-3S)
~ofCommDrce
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EPA/ROD/R05-92/196
Midco II (Amendment), IN
First Remedial Action - Amendment
Abstract (continued)
onsite disposal; excavation and solidification/stabilization of 500 cubic yards of
contaminated sediments followed by onsite disposal; covering the site in accordance with
RCRA landfill closure requirements; ground water pumping and injection into a shallow or
deep aquifer with or without treatment, depending on treatment studies; and implementing
deed and access restrictions. The amended remedy reduces the estimated amount of soil to
be treated, as a result of new information on arsenic data and amended soil CALs, further
defines the site cover requirements, and further defines the requirements for deep well
injection of contaminated ground water. The primary contaminants of concern affecting
the subsurface soil, sediment, and ground water are VOCs, including methylene chloride,
benzene, toluene, TCE, and xylenes; other organics, including PCBs, phenols, and PAHSi
and metals, including chromium, and lead.
The amended remedial action for this ROD includes reducing the amount of soil to be
treated with soil vapor extraction and in-situ solidification/stabilization from
estimated 35,000 cubic yards to an estimated 18,300 cubic yards because of the amended
soil CALs and a determination that arsenic may not be present above background levels;
excavation and onsite solidification/stabilization of an estimated 500 cubic yards of
contaminated sediments from a ditch adjacent to the northeast boundary of the site;
pumping ground water and treating with air stripping and carbon adsorption to
site-specific requirements for onsite deep well injection. Contingency measures are
added in case if the ground water clean-up action levels for the Calumet Aquifer are
technically impracticable to attain; construction of a final vegetated cover over the
entire site that is consistent with RCRA closure requirements; and implementation of
access and deed restrictions and monitoring. The ground water treatment or underground
injection portions of this remedy may be combined with remedial actions for the adjacent
Midco I site. The estimated present worth cost for this amended remedial action is
$13,000,000, which includes an annual O&M cost of $660,000.
PERFORMANCE STANDARDS OR GOALS: Ground water clean-up standards are not changed from the
1989 ROD. Treatment required prior to DWI are further defined compared to the 1989 ROD,
and include at a minimum treatment to ACs, which are required for RCRA delisting.
Specific MACs include methylene chloride 31,5 ug/li trichloroethene 31.5 ug/l; toluene
6,300 ug/li chromium 630 ug/l; nickel 630 ug/l, and lead 99.5 ug/l. Treatment below the
MACs will be required if necessary to protect underground sources of drinking water.
Soil treatment action levels are increased from lx10-6 and HI=1 in the 1989 ROD to
CR=5x10-4 and HI=5 in this ROD.
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DECLARATION FOR RECORD OF DECISION AMENDMENT
SITE NAME AND LOCATION
.
Midco II
Gary, Indiana
STATEMENT OF BASIS AND PURPOSE
This decision document presents a description of an amendment to
the selected remedial action for Midco II developed in accordance
with the comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA), as amended by the Superfund Amendments
and Reauthorization Act of 1986 (SARA), and to the extent
possible the National Oil and Hazardous Substances Pollution
contingency Plan (NCP). This decision document amends the Record
of Decision dated June 30, 1989.
~
This decision is based on the contents of the administrative.
record for the Midco II site. The attached index identifies the
items which comprise the administrative record for this Record of
Decision Amendment.
The State of Indiana concurs in this amendment to the remedy
selection by u.S. EPA for the Midco II site.
ASSESSMENT OF THE SITE
\
Actual or threatened releases of hazardous substances from this
site, if not addressed by implementing the response action
selected in the Record of Decision (ROD) Amendment, may present
an imminent and substantial endangerment to public health,
welfare, or the environment. "
DESCRIPTION OF THE SELECTED REMEDY (AS AMENDED)
The primary reasons for amending the selected remedy at Midco II
relate to: 1) a change in the method 'for determining how much
soil will be treated; 2) further definition of the degree of
treatment of contaminated ground water that EPA will require
prior to deep well injection including a proposal to delist the
extracted ground water (the ground water contains listed
hazardous wastes as defined in the Resource Conservation and
Recovery Act) through this Record of Decision Amendment provided
that the extracted ground water is treated to meet specified
maximum allowable concentrations (MACs) prior to disposing of the
extracted ground water by deep well injection.
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2
The selected remedial action includes:
.
On-site treatment of a minimum of approximately 12,200 cubic
yards of contaminated soil and waste material, and possibly
more dependent upon the results of further sampling; by soil
vapor extraction and in-situ sOlidification/stabilization.
Excavation and on-site sOlidification/stabilization of
approximately 500 cubic yards of contaminated sediments from
the ditch adjacent to the northeast boundary of the site.
~
Installation and operation of a ground water pumping system
to intercept contaminated ground water from the site.
Contingency measures have been added in case it is
technically impracticable from an engineering perspective to
meet the ground water cleanup action levels.
Installation and operation of a treatment system (as
required) to remove hazardous substances from the extracted
ground water, -and deep well injection of the extracted
ground water following any required treatment. Ground water
treatment will be required to the extent necessary to attain
maximum allowable concentrations (MACs), which are levels'
equivalent to those required for delisting a hazardous waste
under the Resource Conservation and Recovery Act (RCRA).
Treatment beyond the MACs will be required under certain
conditions if either the lower Eau Claire or Mount Simon
Formation (which are more than approximately 1800 feet below
the surface of the site) is an underground source of
drinking water (USDW) as defined in 40 CFR 144.3.
Alternatively, the ground water could be treated to remove
hazardous substances followed by reinjection of the ground
water into the Calumet aquifer in a manner that will prevent
spreading of the salt plume.
Construction of a cover over. the entire site that is
consistent with the closure requirement under Subtitle C of
RCRA
Restriction of site access, and deed restrictions.
Long term monitoring and maintenance.
The ground,water treatment or underground injection portions of
the remedial action may be combined with the remedial action for
Midco I. For example, the ground water from Midco II may be
transported to Midco I for treatment or injection, or vice versa.
In this case, the combined treatment or injection shall
constitute an on-site action, for purposes of the Off-site Policy
and compliance with applicable or relevant and appropriate
standards.
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3
DECLARATION
The selected remedy, as modified herein, and including the
contingency measures in case EPA determines that it is
technically impracticable to meet the ground water cleanup action
levels, is protective of human health and the environment, and is
cost effective. The selected remedy also attains Federal and
state requirements that are applicable or relevant and
appropriate to this remedial action, except that some primary
Maximum contaminant Levels will be waived for portions of the
Calumet aquifer, provided that it is demonstrated that it is
technically impracticable from an engineering perspective to
attain these standards and appropriate contingency measures are
implemented.
~
This remedy satisfies the statutory preference for remedies that
employ treatment that reduces toxicity, mobility or volume as a
principal element, and utilizes permanent solutions and
alternative treatment technologies to the maximum extent
practicable.
Because this remedy will result in hazardous substances remaining
on-site, pursuant to section 121 (c) of CERCLA, a review will be
conducted at the site within five years after commencement of the
remedial action and at least every five years thereafter to
ensure that the remedy continues to provide adequate protection
of human health and the environment.
Date
. .
Valdas V. Ada kus
Regional Adm' istrator
Region V
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SUMMARY FOR RECORD OF DECISION AMENDMENT
Hidco II, GARY, INDIANA
I. INTRODUCTION (for more detailed information on the site
location, site description, and the site history, enforcement
activities and community relations prior to June 30, 1989 refer
to the Record of Decision (ROD) signed on June 30, 1989, Sections
I~III)
~
Midco II operations were primarily conducted on an approximately
seven acre area at 5900 Industrial Highway in Gary, Indiana (see
Figures 1 and 2) from approximately 1976 through 1978.
Operations included temporary bulk liquid and drum storage of
waste and reclaimable materials, neutralization of acids and
caustics, and on-site disposal via dumping into pits, which
allowed percolation into the ground water. One of theses pits,
called the filter bed, had an overflow pipe leading into the
ditch. Many of the wastes disposed of on-site were from the
paint industry, and many contained hazardous substances. In
addition, during the operations, wastes were dumped and spilled
onto and into the ground at the site. A large fire in August
1977 destroyed thousands of drums containing chemicals on the
site, and resulted' in additional spillage of chemicals onto the
site.
The United States Environmental Protection Agency (EPA) installed
a fence at the site in 1981, and completed a removal action from
1984 through 1989 that included removal of all surface wastes
including thousands of drums of chemical wastes, and a number of
tanks containing chemical wastes, and excavation and off-site
disposal of subsurface soils and wastes in the sludge pit and
filter bed. other than the sludge pit and filter bed, the
contaminated subsurface soil aRd ground water were not addressed
in the removal action.
A Remedial Investigation/Feasibility Study (RI/FS) was completed
by a group of potentially responsible parties (PRPs) (generally
PRPs are entities who owned or operated Midco II or sent or
transported hazardous substances to the,Midco II site) under EPA
oversight from 1985 to 1989. The Indiana Department of
Environmental Management (IDEM) also participated in oversight of
the RI/FS. The RI showed that portions of the subsurface soils,
including natural soils and fill material, located within the
area outlined in Figure 2 are highly contaminated by a large
number of hazardous substances (including volatile organic
compounds (VOCs), semivolatile organic compounds, PCBs, metals
and cyanide). The fill material consists of sand, slag, cinders,
granular material, and a grey silty material mixed with some
cultural debris including scrap metal, concrete, wood, bricks,
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.
Figure
1
Indiana
MIDCO II
Site Area Map
~
o
.
2000
Scal. In FUI
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N
lIJ
0::
::>
(,!J
......
I.L.
r:J\- 30' RADIUS
V CIRCLE CENTERED ON TEST PIT 11
DETAIL A
r?\- 30' RADIUS
U CIRCLE CENTERED ON TEST PIT 9
DETAIL B
,20',
/,;:0:::::...... i
! i/.-.\\"\ I
Ii i it: \i \I 32'
i\H.\.iiiJi I
\\'.:.,..'.1/
.,'.:::.",.' I
'........ --4
)~
5
COloR...
zz
6' HIGH SOil PilE
DETAIL r
AREA C
FIGURE 2
MlDCO II REMEDIA TI<*
MIDCO .
GARY, N)IANA
ALTERNATIVE 11
~
~30' RADIUS
CIRCLES CENTERED ON TEST PITS
5,7, AND 8
30' RADIUS
3D' RADIUS
DRAlHAc;( 01104
DETAil C
I?r 3D' RADIUS
V CIRCLE CENTERED ON TEST PIT .
LL
DETAIL D
I?r 30' RADIUS
V CIRCLE CENTERED ON TEST PIT 13
DETAil E
APPRO. SCAlE J!q
I
o
lOll
SYMBOL lEGEND:
GRID POINT
MONITORING WElL
LOCATION
TEST PIT lOCATION
MINIMUM AREA FOR
TREATMENT
INITIAL FENCE
LOCATION
MINIMUM COVER
--.-- BOUNDARY
SOIL SAMPLE
COLLECTION AREA
-,-.-.- AND FINAl FENCE
BOUNDARIES
,---_. SOil PILE
.
.
III
UWI
PIU
.
.HJO
M
NN
INOUS 1'IbA&. KlQiWA Y
MilE
" LINES DEMARKING THE INITIAL fENCE LOCATION AND
THE MINIMUM COVER BOUNDARY ARE COINCIOENT.
~~.\\
-
-
AREA C
2. LINES OEMARKING THE INITIAL fENCE LOCATION, MINIMUM
COVER BOUNDARY, SOil SAMPLE COllECTION AREA AND
fiNAl fENCE BOUNDARIES ARE COINCIDENT BETWEEN
GRID POINTS CC, M, AND U.
SEDIMENTS TO BE
REMEDIATED
:'\"
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2
~
crushed drums and other debris. Ground water below the site is
highly contaminated with VOCs, semi volatile organic compounds,
metals and cyanide, but at the time of sampling the contaminated
ground water did not extend very far from the site cover
boundaries outlined in Figure 2. Some surface sediments have
also been contaminated. Much of the ground water affected by the
Midco II operations is highly saline.
After preparing a Proposed Plan and considering public comments,
EPA selected the final remedial actions for the site in the
Record of Decision (ROD) signed on June 30, 1989. IDEM concurred
in the selected remedy. The final remedial actions were to
address the remaining contamination at.the site including
contaminated subsurface soil, contaminated ground water and
contaminated surface sediments. The major components of the
remedy selected by EPA in the 1989 ROD included:
~
On-site treatment of an estimated 35,000 cubic yards of
contaminated soil and waste material by sOlidification/
stabilization followed by on-site deposition of the
solidified material;
Excavation and on-site solidification/stabilization of
approximately. 500 cubic yards of contaminated sediments from
the ditch adjacent to the northeast boundary of the site;
Installation and operation of a ground water pumping system
to intercept contaminated ground water from the site;
Installation and operation of a deep, class I, underground
injection well for disposal of the contaminated ground
water; or if a no-migration petition is not approved by EPA,
treatment of contaminated ground water to remove hazardous
substances followed by deep well injection; or treatment of
the contaminated ground water to remove hazardous substances
followed by reinjection or the ground water into the Calumet
aquifer in a manner. that would prevent spreading of the salt
plume;
Installation of a conduit in the ditch along the site, a
final site cover, access restrictions, deed restrictions,
and monitoring.
EPA with participation by IDEM conducted a 120 day negotiation
period with the PRPs from May until September 1989, but no
agreement was reached. In November 1989, EPA issued a Unilateral
Administrative Order to a group of PRPs requiring them to
implement the remedial action called for in the ROD, This Order
became effective on December 29, 1989. However, the PRPs did not
agree to implement the Order without addition of conditions that
were unacceptable to EPA. On January 8, 1990, the United States
filed an Amended Complaint seeking to enforce the Unilateral
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3
Administrative Order, as well as to recover EPA's response costs,
punitive damages, and fines.
~
In 1991, EPA determined that the arsenic data from the Midco II
Remedial Investigation was mostly unusable because of an
interference with high concentrations of aluminum in many of the
samples (see Section III). Because arsenic was an important
factor in determining the extent of soil treatment by S/S at
Midco II, EPA considered the new information on the arsenic data
to be fundamental new information. EPA has therefore
reconsidered the 1989 ROD's provisions relating to the extent of
soil treatment by S/S, and has at the same time in this ROD
Amendment applied new Agency regulations (e.g. the revised NCP
. issued March 8, 1990, 40 CFR 300.430{a) (iii) II (A) EPA expects to
use treatment to address the principal threats posed by the site
wherever practicable.... (B) EPA expects to use engineering
controls such as containment for waste that poses a relatively
low long-term threat....") dealing with the extent of soil
treatment at Superfund sites. This ROD Amendment also provides
further detail regarding the implementation of various other
components of the 1989 ROD. The revisions to the 1989 ROD are
discussed in more detail later in this document.
EPA, IDEM, and a group of PRPs have since reached a proposed
settlement consistent with this ROD Amendment. This settlement
has been embodied in a Consent Decree that is being submitted for
public comment concurrently with this proposed ROD Amendment. A
detailed statement of Work that would implement the remedial
action that is the subject of the ROD Amendment is incorporated
in the Consent Decree that is being lodged with the Federal
District Court in Hammond, Indiana for public comment." This ROD
Amendment incorporates the elements of the proposed remedial
action, as well as providing updated information on the site.
The remedy selected in this ROD Amendment. includes the following
major components:
. .
On-site treatment of a minimum of approximately 12,200 cubic
yards of contaminated soil and waste material, and possibly
more dependent upon the results of further sampling, by SVE
and in-situ S/S.
Excavation and on-site SIS of approximately 500 cubic yards
of contaminated sediments from the ditch adjacent to the
northeast boundary of the site.
Installation and operation of a ground water pumping system
to intercept contaminated ground water from the site.
Contingency measures shall be implemented in case it is
determined that it is technically impracticable from an
engineering perspective to attain the ground water cleanup
action level.
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4
.
Installation and operation of a treatment system (as
required) to remove hazardous substances from the extracted
ground water, and deep well injection of the extracted
ground water following any required treatment. Ground
water treatment will be required to the extent necessary to
attain maximum allowable concentrations (MACs), which are
levels equivalent to those required for delisting a
hazardous waste under the Resource Conservation and Recovery
Act (RCRA). Treatment beyond the MACs will be required
under certain conditions if' either the lower Eau Claire or
Mount Simon Formation (which are more than approximately
1800 feet below the surface of the site) is an underground
source of drinking water (USDW) as defined in 40 CFR 144.3.
Alternatively, the ground water could be treated to remove
hazardous substances followed by reinjection of the ground
water into the Calumet aquifer in a manner that will prevent
spreading of the salt plume. See Section V.A of this ROD
Amendment Summary.
~
Construction of a cover over the entire site that is
consistent with the closure requirement under Subtitl~ C of
RCRA, access restriction, deed restrictions, and monitoring.
The ROD Amendment is similar to the 1989 ROD to the extent that
it utilizes the same remedial technologies for soil and ground
water remediation (ie. soil sOlidification/stabilization, soil
vapor extraction, ground water extraction, treatment and deep
well injection, and final site cover). The ROD Amendment
utilizes different methods from the 1989 ROD for determining the
amount of soil that must be treated, further defines the'
requirements for an effective site cover over soils with low
levels of contamination that are not being treated, and further
defines the requirements for treatment of ground water prior to
deep well injection. It is expected that less soil and ground
water treatment (see Section V.A) will be required under the ROD
Amendment. In spite ~f this, the -ROD Amendment achieves a level
of protection of public health and the environment that is not
considered significantly different from what would have been
achieved by the 1989 ROD. The ROD Amendment's provisions provide
such protection by providing for treatment of principal threats
(that is the highly contaminated soils) and mandating an
effective site cover over untreated soils that pose a relatively
low long-term threat. The site cover 'will substant~ally reduce
the threat from the soils presenting a relatively low long-term
threat: for the direct contact threat by covering the soil with a
five foot thick cover: and for the threat of further ground water
contamination from the soils above the water table by reducing
infiltration through the soils and production of leachate. To
maintain its effectiveness, the site cover and solidified/
stabilized material will have to be monitored and maintained.
In contrast, the 1989 ROD provided for treatment of soils posing
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5
.
a relatively low long-term threat by SVE and S/S. This may have
resulted in permanent treatment of some additional contaminants
and would have resulted in a reduction of leaching and control of
the direct contact threat by the treatment and a .cover. However,
in spite of the additional treatment, unrestricted future usage
of the site would not have been allowed because long term
maintenance and monitoring of the solidified/stabilized material
and the cover would have been required. Any reduction in
protectiveness from the change in the ROD Amendment's soil
treatment action levels (see Section V.C) from the 1989 ROD's.
soil cleanup action levels (see section IV) are compensated for
by taking into account the risk reducing effect from the site
cover over untreated soils posing low level threats. The ROD
. Amendment includes new requirements for the final site cover to
ensure its effectiveness. Because the risk reduction and
reduction in toxicity or mobility of the additional treatment
required in Alternative 8 compared to Alternative 10 is small, it
is not considered to be cost effective compared to Alternative
10.
~
A Proposed Plan has been prepared that briefly describes the
remedial alternatives analyzed by EPA, proposes the revised:
alternative, and summarizes the information relied upon to select
this alternative. This proposed ROD Amendment as well as the
Proposed Plan will: be subject to a public notice, public comment
period, and the opportunity for a public meeting, in accordance
with the requirements of 40 CFR 300.435(c). In addition, the ROD
Amendment and supporting information will be made available to
the public in the Administrative Record for this action.
II.
PURPOSE OF ROD AMENDMENT
The major purpose of this ROD Amendment is to modify the 1989
ROD's provisions relating to t~e extent of soil treatment by S/S,
as a result of new. information on the arsenic data. At the same
time, the ROD Amendment applies new EPA regulations (e.g. the
revised NCP issued March 8, 1990, 40 CFR 300.430(a) (iii) II (A) EPA
expects to use treatment to address the principal threats posed
by the site wherever practicable.... (B) EPA expects to use
engineering controls, such as containmept for waste that poses a
relatively low long-term threat....") .dealing with the extent of
soil treatment at Superfund sites. .
This ROD Amendment provides for direct treatment of soils at what
are.bel~eved to be the more highly contaminated areas of the
site, which are the source of the principal threats to ground
water, air and dermal contact. Large volumes of soils presenting
a relatively low long-term threat will not be treated since (in
the context of the conditions at this site) the threats from such
soils can be reliably controlled using an effective site cover.
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6
.
A minimum of approximately 12,200 cubic yards (depicted in Figure
2) will be treateq without further sampling, and additional
amounts may have to be treated depending upon the results of
further sampling.
The action levels for additional soil treatment outside of the
areas outlined in Figure 2 are as follows:
cumulative lifetime carcinogenic risk
cumulative chronic non-carcinogenic risk index
lead concentration (mgjkg)
= 5 X 10-4
= 5.0
= 1000
"j.
These action levels were selected taking into account treatment
of the minimum area for treament identified in Figure 2, site
characteristics and hazardous substances, and current EPA
regulations, policies, and guidance. The cover will be over the
entire site and will be consistent with RCRA subtitle C closure
requirements. The extent and quality of the site cover under the
1989 ROD was left open (depending upon the success of the
treatment) .
Another purpose of this ROD Amendment is to further define the;
requirements for treatment prior to deep well injection of the
extracted ground water, including a proposal to delist extracted
ground water (following treatment as required) meeting specified
maximum allowable concentrations (MACs) in accordance with "A
Guide To Delisting of RCRA Wastes For Superfund Remedial
Responses" (September 1990) so that the ground water can be
injected into the lower Mount Simon formation in compliance with
the requirements of RCRA and the Underground Injection Control
Program (see Section V.A for further explanation of MACs). In
effect, treatment to the MACs would take the place of the 1989
ROD's requirement of treatment to RCRA Land Disposal Restriction
(LDR) treatment standards prior to the deep well injection.
Treatment beyond the MACs will be required under certain
conditions (see Section V.A) ir.either the lower Eau Claire or
Mount Simon Formation (which are more than approximately 1800
feet below the surface of the site) is an underground source of
drinking water (USDW) as defined in 40 CFR 144.3.
This ROD Amendment also further defines the remedial actions as
follows:
definition of phases and sequencing for ground water and
soil treatment;
further definition of performance standards for SjS;
a decision that the in-situ SjS option allowed in the 1989
ROD will be implemented rather than the excavation option;
a decision that the option of deep well injection without
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7
prior treatment, which would require EPA approval of a no-
migration petition will no longer be considered (Alternative
7) ;
contingency measures have been added in case it is
technically impracticable to attain the ground water cleanup
action levels;
further definition of construction requir~ments for the site
cover;
~I
a determination that air emissions during in-situ SIS and
during SVE conducted with the in-situ SIS equipment shall be
controlled by carbon adsorption or by another technology
that is equally effective; .
a determination that in addition to the above if cumulative
air emissions from all operations other than excavation at
the Facility exceed 3 pounds per hour, carbon adsorption or
another technology that is equally effective shall be used
in the ground water treatment system and all SVE;
further definition of
with the requ:irements
Executive Order 11990
Act.
actions that will be taken to comply
for protection of wetlands in
and Section 404 of the Clean Water
This ROD Amendment also provides updated information on the site
in the following section.
III. SITE CHARACTERISTICS AND SUMMARY OF RISKS (this Section
updates information on site characteristics and risk in Sections
V and VI of the 1989 ROD)
, .
Some new information has been obtained regarding Midco II since
the 1989 ROD was signed. This new information is reported in
this portion of the ROD Amendment.
Subsequent to completion of the 1989 ROD, EPA became aware that
the arsenic concentrations reported for' 'some soil and sediment
samples in Midco II the Remedial Investigation, could be inflated
due to an analytical interference from high aluminum.
concentrations in these samples. This was significant because
any arsenic concentrations exceeding background would exceed the
1 X 10-5 carcinogenic risk level and require soil treatment by
SVE and SIS under the 1989 ROD. In response, EPA investigated
this concern and determined that the higher arsenic soil
concentrations reported in the RI were unreliable. As a result
the actual extent of soil treatment by SVE and SIS required in
the 1989 ROD would likely have been considerably less than
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~
estimated in the Feasibility Study dated February 1989.
From an EPA audit of some of the soil data, EPA determined that
the arsenic measurements in soil samples with aluminum
concentrations greater than 10,000 mg/kg should be considered
unusable because an adequate background correction for the
aluminum interference was not applied. At Midco II, four soil
boring samples, twenty test pit samples and six surface sediment
samples exceeded aluminum concentrations of 10,000 mg/kg. Tbese
samples generally had the highest arsenic results. Sampling
conducted at Midco II during February 1991 confirmed that the
aluminum interference caused inflated arsenic results if an
adequate background correction was not applied. Without the
background correction, arsenic was reported from 313 to 1780
mg/kg in the Midco II soil samples, with the proper background
correction (using a Zieman detector) arsenic was reported from
less than 9 to 24 mg/kg. This sampling and the analyses of these
samples were conducted by some PRPs with EPA oversight and in
accordance with procedures approved by EPA.
.
If arsenic values in the soil samples with aluminum
concentrations greater than 10,000 mg/kg are excluded from the
risk calculations, the estimated averaged, site-wide, lifetime,
cumulative, carcinogenic risk due to ingestion of soils using the
future development scenario decreases from 3.3 X 10'4, as
reported in the 1989 ROD, to 5.7 X 10.5 (Table 4-22 of the
Addendum to Public Comment Feasibility Study, February 10, 1989).
The non-carcinogenic risk index for exposure to soils would
change from 2.99 to 1.7. The revised soil risks without arsenic
were taken into account in determining the minimum areas for S/S
defined in Section V.C, and Figure 2 of this ROD Amendment.
To update the risk assessment calculation procedures for soil
risks, EPA asked Planning Research Corporation (PRC) to conduct
additional risk calculations using the data from the Midco II
Remedial Investigation. The r1sks reported in the 1989 ROD did
not include dermal contact or inhalation modes of exposure to the
soils. The results of PRC's calculations are presented in a
letter report dated June 21, 1991. The risks were calculated
using the average soil concentrations in samples from test pits
dug into what was suspected to be the m~st contaminated areas of
the site during the Remedial Investigation and using a dermal
contact and inhalation mode of exposure as well as the ingestion.
mode of exposure used in the Remedial Investigation. It was
assumed that a home with a basement would be built on the site
and that as a result the residents would be exposed to soil gas
from the site. . Very high carcinogenic risks to on-site residents
were calculated due to inhalation exposures to volatile organic
compounds including: methylene chloride (risk = 0.0142); and
trichloroethylene (risk = 0.032). Very high non-carcinogenic
risks to on-site residents were also calculated due to inhalation
exposures to volatile organic compounds including: methylene
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9
chloride (risk index = 2.1): 2-butanone (risk index = 4.1): and
toluene (risk index = 440). Not including arsenic or the
inhalation mode of exposure, the calculations indicate a
cumulative carcinogenic risk from the dermal contact and
ingestion modes of exposure to be 1.7 X 10.4: and the cumulative
non-carcinogenic risk index to be 5.61. The calculations
indicate a cumulative carcinogenic risk to hypothetical
construction workers to be 1.1 X 10-6 and a cumulative non-
carcinogenic risk index to be 2.1. These revised risk
calculations provide further support of EPA's remedial action
decisions for the Midco II site.
~
Since the 1989 ROD was completed, the United States Fish and
Wildlife Service (U.S. F&W) completed a report entitled: "Summary
Addendum Report for the Midco I, Midco II, and Ninth Avenue Dump
Hazardous Waste Sites in Gary, Lake County, Indiana", September
1990. In this report, the U.S. F&W concluded that "the various
contaminated habitats/media at Midco I, Midco II, and the 9th
Avenue Dump sites present a threat to fish and wildlife resources
utilizing or exposed to them." This additional documentation
provides further support of EPA's remedial action decisions for
the Midco II site.
IV. DESCRIPTION OF THE REMEDY SELECTED IN THE 1989 ROD
(ALTERNATIVE 8): GROUND WATER PUMPING. TREATMENT AND DEEP WELL
INJECTION WITH SOLIDIFICATION/STABILIZATION
The remedy selected in the 1989 ROD (Alternative 7 or 8) combined
either ground water Alternative 4A (Alternative 7) or 4B
(Alternative 8), with soil treatment Alternative 5E.
Implementation of Alternative 7 was contingent upon EPA approval
of a no-migration petition pursuant to 40 CFR 268.6 and 40 CFR
148 Subpart C. After the ROD was approved, EPA obtained
information from revi~w of the.Inland steel and U.S. Steel no-
miqration petitions that indicated that it. is very unlikely that
a no-miqration petition would be approved for deep well injection
at the Midco II site. Therefore, the subsequent discussion uses
only Alternative 8.
Alternative 8 included installation and..operation of ground water'
extraction wells to intercept the contaminated ground water that
exceeds the ground water cleanup action levels (CALs) identified.
in Section X of the 1989 ROD, and installation of a Class I
hazardous waste underground injection well into the Mount Simon
formation for disposal of the highly saline waste water.
The extracted ground water was to have been. treated to remove
hazardous substances to the extent required by EPA prior to the
deep well injection. While the extent of treatment that would be
required by EPA was not fully defined, it was anticipated that
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..
this would at least require meeting Land Disposal Restriction
(LDR) treatment standards for listed hazardous waste categories
FOOl, F002, F003, F005, F007, F008, F009. This was anticipated
to require treatment of the extracted ground water by air
stripping and carbon absorption. However, Alternative 8 included
provisions for treating to drinking water standards if required
in order to gain approval of the deep well injection. Treating
to drinking water standards was anticipated to require metals
precipitation, and cyanide oxidation in addition to the air
stripping and carbon absorption.
In the 1989 ROD, no mention was made of delisting the ground
water because at that time no guidance was available on the level
of treatment required to delist ground water. It was anticipated
that delisting the ground water would require more stringent
treatment than meeting the LDR treatment standards.
~I
Another option that was allowed under Alternative 8 was treatment
of the hazardous substances followed by reinjection of the
treated ground water back into the Calumet aquifer in a manner
that would not spread the salt plume in the Calumet aquifer. T~e
pump, treatment and injection system would be operated until
ground water CALs are attained in the Calumet aquifer.
Contaminated subsurface soils located above the water table were
to have been treated by S/S (and by SVE if necessary). At the.
end of the action, all soils exceeding the soil CALs (Section X
of the 1989 ROD) located above the water table had to be treated.
In addition, S/S would be conducted on highly contaminated
materials below the water table that could be handled by
localized dewatering. Contaminated soils below the water table
that were not treated would be slowly .remediated by the ground
water extraction system through ground water flushing. The soil
CALs were based on contaminant concentrations that would allow
for unrestricted future usage of the site, and were defined as
follows: -'.
cumulative lifetime carcinogenic risk = 1 X 10-5
cumulative chronic non-carcinogenic index = 1.0
Under Alternative 8, the S/S of the subsurface soils could have
been conducted either by excavation followed by S/S, or by in-
situ S/S. Under the excavation option, SVE was required if
necessary to meet the LDR treatment standards. Under the in-situ
S/S option, SVE was required prior to in-situ S/S to the extent
necessary to assure-that leachate from the solidified mass would
not cause exceedance of the ground water CALs.
Sediments in the areas shown in Figure 2, would be excavated and
treated on-site by S/S along with the contaminated soils.
Following the S/S treatment, a conduit would be installed in the
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ditch north of the site, and the area treated by SIS would be
covered to meet the requirements of RCRA if the excavation and
SIS option was used, otherwise the quality of the site cover
would depend on the success of the SIS operation. Ground water
use restrictions, access restrictions and long term monitoring
were also required.
V. DESCRIPTION OF NEW ALTERNATIVE (ALTERNATIVE 10): GROUND
WATER PUMPING. TREATMENT AND DEEP WELL INJECTION WITH SOIL VAPOR
EXTRACTION AND SOLIDIFICATION/STABILIZATION
A.
Ground Water Pumping, Treatment and Disposal
~
Like Alternative 8 in the 1989 ROD, the new Alternative 10
includes installation and operation of a ground water extraction
system to intercept the contaminated ground water that exceeds
the ground water CALs, and installation of a deep underground
injection well for disposal of the ground water. As stated
before, Alternative 10 proposes to delist extracted ground water
by meeting specified maximum allowable concentrations (MACS) in
accordance with "A Guide To Delisting of RCRA Wastes For
Superfund Remedial' Responses" (September 1990) so that the ground
water can be injected into the lower Mount Simon formation in
compliance with the requirements of RCRA and the underground
Injection Control Program. Although the 1989 ROD did not mention
delisting of the ground water, it is probable that this same
delisting procedure would have been used under Alternative 8,
because Alternative 8 was worded broadly enough to allow this
procedure, for the same reasons that it is now being proposed for
Alternative 10. .
The MACs are defined below. For purposes of compliance with
RCRA, treatment to the MACs would take the place of the 1989
ROD's requirement of treatment to RCRA LDR treatment standards
prior to the deep well injection.
In accordance with the delisting guidance, a superfund waste can
be delisted if it attains or is treated to attain levels that
will not cause exceedance of health based levels (HBLs) used for
delisting decisions at a hypothetical receptor well using generic
assumptions and an appropriate ground water transport model such
as the vertical and horizontal spread (VHS) model. The HBLs are
set at concentrations of constituents that provide protection for
drinking water usage (primary Maximum contaminant levels (MCLs)
from 40 CFR Part 141 are the HBLs when available, otherwise the
HBL is set at the 1 X 10'6 carcinogenic risk level or the level.
that will not cause a non-carcinogenic risk assuming that 2 liter
per day is ingested over a 70 year lifetime). The HBLs for this
action are listed in Appendix I.. The VHS model is often accepted
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.
in the RCRA delisting program for use in estimating the extent to
which toxicant leaching from a subtitle D landfill will be
diluted within a surficial aquifer before it reaches a
hypothetical receptor well 500 feet down gradient. While these
modeling conditions are not designed to fit the conditions for
deep well injection at Midco I, they will be used for the
delisting demonstration in this ROD Amendment because the
delisti~g determination is generic and is not a site specific
determination, and because the results using these modelling
conditions are conservative for the disposal in a deep well in
this location.
~
using the VHS model, the dilution factor derived from the model
depends on the volume of the liquid entering the ground water.
Because the volume of ground water that will be deep well
injected is large, the resulting dilution factor using the model
. is 6.3. It follows that the Midco II ground water can be .
delisted if the hazardous substances contained in it are or are
treated to be less than 6.3 times the HBLs. The quantity 6.3
times the HBLs will be referred to as the maximum allowable
concentrations (MACs). Under Alternative 10, EPA proposes to
delist the extracted ground water through this ROD Amendment b~
providing for treatment of the extracted ground water to below
the MACs prior to deep well injection. This delisting satisfies
the substantive requirements of 40 CFR 260.20 and 260.22.
The Midco II FS dated February 10, 1989 and the reviews conducted
for the FS provide documentation that the ground water can be
treated to the MACs. Related information is included in a report
entitled Midco I and II Delisting Demonstration, May 16, 1991.
In addition, a pilot study shall be conducted using the actual
extraction well network. Information from the pilot study will
be used to properly design the treatment system to assure that
the MACs will be met in the treated ground water. After
initiation of the operation, sampling will be conducted on the
treated ground water to verify.that MACs are being met. This
sampling shall be fully .defined'during the design phase of this
project. Since the ground water will be delisted, the deep
underground injection well for Alternative 10 will meet the
requirements for a non-hazardous injection well rather than
requirements for a hazardous injection well. In particular,
siting "requirements in 40 CFR 146.62 wi~l not be an applicable or
relevant and appropriate requirement (ARAR) for Alternative 10.
Some MACs are higher than the LDR treatment standards for the
same compound, and some are lower. Generally for the less toxic
compounds, the MACs are less stringent than the LDR treatment
standards, while for the more toxic compounds the MACs are more
stringent. This is summarized for some compounds of concern at
Midco I in the following comparison:
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COMPOUND MACS (MG/L)
acetone 25.2
chlorobenzene 0.63
ethylbenzene 4.4
methylene chloride Q.0315
methyl ethyl ketone 12.6
tetrachloroethylene 0.0315
toluene 6.3
1,1,1-trichoroethane 1.26
trichloroethylene 0.0315
:l
xylene 63
cyanide 1.26
chromium 0.63
lead 0.95
nickel 0.63
LDR (MG/L)
0.05
0.15
0.05
0.2
0.05
0.079
1.12
1.05
0.062
0.05
1.9
0.32
0.04
0.44
More compounds are regulated under the delisting procedures than
have applicable LDR treatment standards.
The end result of using the delisting procedures is that, while
the action is still protective, it may be. possible that the MACs
can be attained by air stripping alone, while compliance with the
LDR treatment standards was expected to require treatment by
carbon adsorption in addition to air stripping. However, it is
possible that further treatment by carbon adsorption and metal
precipitation, or alternative treatment processes will be
required to meet the MACs. Waivers of some siting requirements
for deep well injection of hazardous wastes (40 CFR 146.62) will
not be required once tne ground water is delisted.
After the ground water has been delisted and has. met the MACs, it
will be injected into the lower Mount Simon Formation without
further treatment by means of a deep well constructed according
to Class I non-hazardous underground injection wel~ requirements
if either of the conditions (lor 2) below is met:
1. Neither the Lower Eau Claire nor the Mount Simon Formations
below the well site is a USDW as defined in 40 CFR 144.3.
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.
2. The injection of the ground water will not cause (for each
constituent for which a Safe Drinking Water Act Maximum
Contaminant Levels' (MCL) exists): a) the exceedance of Safe
Drinking Water MCLs at the point of entry of the injected ground
water into any portion of the Lower Eau Claire Formation or Mount
Simon Formation that is a USDW pursuant to 40 CFR 144.3; or b)
the exceedance of natural background levels present in any
portion of the Lower Eau Clair or Mount Simon Formation that is a
USDW pursuant to 40 CFR 144.3--whichever level is least
stringent.
~
Preliminary modelling indicates that injection of the ground
water meeting the MACs into the Lower Mount Simon Formation will
. meet the requirements of 2 above. However, this must be
confirmed using information from sampling and testing conducted
at the injection well location. If the sampling and testing
confirms that the technical premises of the preliminary modelling
are reasonably conservative, the delisted ground water meeting
the MACs will be injected without further treatment. However, if
additional treatment is required to ensure that the requirements
of 2 above will be met, sufficient treatment will be provided to
ensure that the injection of the ground water will meet the'
requirements of condition 2 above.
Based on preliminary modelling of the deep well injection, EPA
believes that it is unlikely that deep well injection into the
lower Mount Simon Formation would cause the exceedance of natural
background levels of TDS in the lowermost USDW. However, in the
unlikely event that it is determined based on modelling that deep
well injection into the lower Mount Simon Formation would cause
such an exceedance, this ROD amendment may be reconsidered. This
ROD may also have to be reconsidered in the unlikely event that
the Lower Mount Simon Formation is a USDW.
Alternative 10 also includes the ~ollowing:
1.
Like Alternative 8, Alternative 10 includes the option of
treatment of the extracted ground water for hazardous
substances followed by reinjection of the treated ground
water into the Calumet aquifer, if the reinjection is
conducted in a manner that will not cause spreading of the
. salt plume. .
2.
Midco I. Midco II. and the Ninth Avenue Dumo mav be treated
as one site for ourooses of oermittina and comoliance with
EPA's Off-site policv.
Where two or more noncontiguous facilities are reasonably
related on the bases of geography or on the basis of the
threat or potential threat to the public health or the
environment, the two facilities may be treated as one for
purposes of permitting and compliance with EPA's Off-site
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3.
Policy (see Section 104(d)(4) of the Comprehensive
Environmental Response Compensation and Liability Act
(CERCLA». Midco I and Ninth Avenue Dump are located within
200 yards of each other and are 2.5 miles from Midco II.
All three facilities are located in the same industrial area
on former wetlands that have been partially filled. Midco I
and Midco II were part of the same disposal and treatment
operation. All three facilities had organic solvents, heavy
metals and other hazardous substances disposed on the
facility. In addition, Midco I and Midco II have the same
requirements for treatment ~nd deep underground injection of
the ground water. Therefore, based on the similar geography
and threat, the three facilities may be treated as one
facility for purposes of permitting and compliance with
EPA's Off-site Policy if ground water treatment or deep well
injection is combined with Midco II or Ninth Avenue Dump at
the Midco I or Midco II sites, or if a pipeline is
constructed to transport the extracted ground water (before
or after treatment) from Midco I to Midco II or vice versa.
Since combined treatment, deep well injection, and' transport
in a pipeline between facilities would be considered on-s~te
actions, permits and compliance with EPA's Off-site Policy
for these actions will not be required since the substantive
and administrative requirements of the permits will be
incorporated into the review process for this CERCLA action
(see Section 121(e) of CERCLA and 40 CFR 300.400(e».
It will be advantageous to place the deep injection welles)
outside of the main areas of contamination from the Midco I
and Midco II site because this may lessen the potential for
contamination of aquifers below the Calumet Aquifer during
the installation of the well, and it will be advantageous to
place the deep injection well and ground water treatment
facility outside of the main areas of contamination from the
Midco I and Midco II sites because that may lessen the
potential for conflict with the construction and operations
for soil treatment and the site cover. Therefore
construction and operation of the deep injection well, and
ground water treatment facility on areas in very close
proximity but outside of the areas of contamination will be
on-site (consistent with the .NCP 40 CFR 300.400(e)(1). This
. will include property at the Indiana Department of
Transportation facility located at 7306 West 15th Avenue in
Gary, Indiana.
4.
The injection well must be constructed, installed, tested,
monitored, operated, closed and abandoned in accordance with
the substantive requirements and conditions of Subparts A,
B, D, and E of 40 CFR 144, and Subparts A, B, and F of and
40 CFR 146.
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5.
Responses to operational problems and implementation of
corrective actions must be in accordance with the
substantive requirements of 40 CFR 146.64, 146.67, 144.12,
144.51(d) and 144.55. This includes the requirements for
construction, monitoring, reporting, well plugging, and
injection well closure as necessary to prevent movement of
any contaminant into a USDW, due to operation of the
injection well. It also includes implementation of remedial
actions to restore any USDW that becomes contaminated as a
result of the operation of the underground injection well
pursuant to Section 3004(u) and 3008(h) of the 1984
Hazardous and Solid Waste Amendments, and section 1431 of
the Safe Drinking Water Act.
Air emissions from an air stripper (or similar device) shall
meet the requirements defined in Section V.D.
6.
7.
Until the extracted ground water meets the MACs, the
extracted ground water shall be managed as a hazardous waste
in accordance'with the substantive requirements of RCRA.
B. Ground Water Cleanup Action Levels (CALs) and contingency
Measures in Case of Technical Impracticability:
The ground water CALs in Alternative 10 are unchanged from
Alternative 8. The ground water CALS are summarized below and
calculated in accordance with procedures defined in Appendix II:
Ground water throughout the Calumet aquifer affected by
Midco II that exceed any of the following risk-based levels
will be recovered and treated (except as provided for in the
procedures defined in Appendix II). The ground water pump,
treatment and injection system shall be operated until the
hazardous substances throughout the Calumet aquifer affected
by Midco II have .been red~~ed below each of these risk-based
levels (except as provided for in the procedures defined in
Appendix II).. Applying the CALs throughout the contaminated
plume is consistent with F.R., Vol. 53, No. 245, P. 51426.
CUmulative Lifetime Carcinogenic Risk = 1 X 10.5
Cumulative Non-carcinogenic Index = 1.0
Primary Maximum Contamin~ntLevels (40 CFR 141)
Chronic Ambient Water Quality Criteria for aqUatic life
(AWQC) multiplied by a factor of 3.6
The ground water CALs have been selected to be protective for use
of the aquifer for residential purposes including drinking water
consumption, and to protect aquatic life from recharge of ground
water affected by the Midco II site.
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.
Based on information in the Administrative Record, EPA believes
that a ground water extraction system can attain the ground water
CALs. However, the technical practicability of achieving the
ground water CALs from an engineering perspective throughout the
Calumet aquifer cannot be fully determined until the extraction
system has been implemented and the plume response monitored over
time. Before concluding whether it is technically impracticable
to attain the ground water CALs, modifications to the design and
operation of ground water extraction system wil.l be considered,
including:
a) discontinuing operation of extraction wells in areas
where ground water CALs are attained;
b) alternative pumping at wells to eliminate stagnation
points and to increase contaminant reductions;
~
c) varied or intermittent operation of the system (pulse
pumping) to allow aquifer equilibration and encourage
adsorbed contaminants to partition into ground water;
d) physical repositioning of extraction wells to capture
alternative flow line/transport pathways to increase
contaminant reductions;
If a ground water extraction system cannot meet the ground water
CALs after ten years of operation and it is determined based on a
demonstration that it is technically impracticable from an
engineering perspective to attain the ground water CALs even
considering the potential changes to the design and operation of
the system listed above, the ground water CALs may be changed to
the lowest acheivable levels attainable using ground water
extraction technology. In addition, the selected remedy may
include the contingency measures described below.
a) additional institutional controls to prevent human access
to contaminated ground water (institutional controls may
include deed restrictions sought voluntarily from owners or
compelled to the extent authorized under any applicable
local and State laws);
b) low-level pumping as a long-term gradient control or
containment measure to prevent. recharge of the surrounding
wetlands from exceeding the Ambient Water Quality Criteria
for aquatic life, and to prevent human access to the ground
water exceeding the CALs that are based on drinking water
usage.
Any ARARs based on the primary MCLs that exceed the lowest
achievable levels attainable by the ground water extraction
technology, will be waived by EPA, if EPA in the future makes a
finding of technical impracticability.
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c.
Soil Treatment:
.
~lternative 10, like Alternative 8, includes provisions for
treatment of the subsurface soils by SVE and in-situ S/S. Highly
contaminated subsurface soils located above the water table will
be treated by solidification/stabilization (S/S) and soil vapor
extraction (SVE). contaminated soils below the water table will
be slowly remediated by the ground water extraction system
through ground water flushing. Following is a description of the
soil treatment requirements in order of the phases for the soil
treatment.
1. Ground water pump and treatment:
The pump and treatment system will operate for a period of up to
36 months before direct soil treatment by in-situ S/S or SVE is
initiated. The purpose of this is to attempt to reduce volatile
organic compounds (VOCs) prior to the direct soil treatment
operations.
~
2. In-situ S/S and SVE:
Following the initial period of pumping and treatment and
successful completion of a treatability study and pilot study on
S/S and SVE, portions of the subsurface soils shall be treated by
SVE and in-situ S/S. At least the soils in the areas and to the
depths labeled minimum area for treatment on the map in Figure 2
(which are believed to include the more highly contaminated
soils) will be treated first by SVE and then by in-situ S/S. In
addition, soils outside the mapped areas will be sampled to
determined whether further SVE and S/S will be conducted.
Sampling will be conducted as defined in Appendix III to
determine the full extent of soil treatment outside of the mapped
areas. Using these sampling results, the cumulative risks at
each sample location will be calculated for the ingestion, dermal
contact, and inhalation modes of exposure using the procedures
outlined in the Appendix'IV. Based on these results, treatment
by SVE and S/S will be conducted outside of the minimum areas to
be treated delineated in Figure 2 if the following soil treatment
action 'levels are exceeded:
Soil Treatment Action Levels:
cumulative lifetime carcinogenic risk =5 X 10.'
cumulative chronic non-carcinogenic risk index=5.0
lead'concentration (mg/kg) =1000 '
These action levels were selected taking into account treatment
of the minimum area for treatment identified in Figure 2, site
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19
characteristics and hazardous substances, and current EPA "
regulations, policies and guidance.
If these action levels are exceeded for a sample, the soil within
the 20 foot square or 60 foot square (if the square is not
subsampled) represented by this sample will be treated to a depth
of 8 feet, unless sampling indicates that the soil does not
exceed the action levels at depths between 4 and 6 feet, in which
case the soil will be treated to.a depth of 4 feet.
~
The treatment will be first by SVE and then by S/S unless the
exceedance of the Soil Treatment Action Level can be corrected by
removing VOCs, in which case only SVE need be used.
In Area C identified on Figure 2, in lieu of conducting SVE and
in-situ S/S, the soil may be excavated and" consolidated within
the boundaries of the minimum area for treatment indicated on
Figure 2, and the excavated soil treated by in-situ S/s along
with the soils in such areas if the following conditions are met:
1) it is demonstrated that VOC emissions from the excavation and
consolidation will not exceed the criteria for air emission in
section V.D; 2) the exceedance of the Soil Treatment Action
Levels cannot be c9rrected by SVE; and 3) the total quantity
excavated is limited.
If the sample from the soil pile (as shown on Figure 2 exceeds
the Soil Treatment Action Levels, this pile will be spread onto
other areas that require S/S and treated by in-situ S/S along
with the soil below it.
If the treatability study and a pilot study show that the
equipment used for the in-situ S/S has potential to achieve a 90%
reduction in the soil concentrations of the following VOCs:
benzene, methylene chloride, trichloroethylene, tetrachloro-
ethylene, 1, 1, 1-trichloroethane, 1,1-dichloroethylene, trans-1,2-
dichloroethylene, and vinyl chTor1de, and ~hat the air emission
requirements in Section V.D can be satisfied using the S/S
equipment, SVE could be conducted using the same equipment and
air pollution controls as used for the s/s.' In this case, the
fresh air (or possibly heated air or steam) would be injected
into the soil while the blades of the auger mix the soil and
while the contaminated air is drawn off. with the induced draft
fan into an air pollution control device. Following the SVE
operation, the same soil that was treated by SVE could be treated
by S/S. The SVE must continue until there is a 97% reduction in
total VOCs (but not less than three times the ambient level) in
the off-gas prior to any air pollution control device during
, In conjunction with the treatability study on S/S discussed
in this section, EPA is conducting treatability tests simulating
use of in-situ equipment for conducting the SVE.
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vigorous agitation of the soils. Air emissions must be
controlled in accordance with the requirements defined in section
V.D.
~
Alternatively, SVE would be conducted as a separate operation
from S/S using vacuum and air injection pumps connected by pipes
to a series of air injection and extraction wells. In addition, a
low permeability cover may be required over the area being
treated. The air pressure gradient would draw Voc-contaminated
air from the soil pores. The removed VOCs would be required to
be processed in a liquid-vapor separator and the air emissions
would have to meet the requirements in Section V.D. The SVE must
continue until treatment by in-situ S/S can be conducted in
compliance with the air emission requirements in section V.D, and
there is a 97% reduction in total VOCs in the soils being treated
(but not to a concentration less than ten times the detection
limit of each constituent).
It is anticipated that the in-situ S/S system would utilize a
crane-mounted mixing system. The mixing head would be enclosed
in a bottom-opened cylinder to allow closed system mixing of the
treatment chemicals with the soil. The bottom-opened cylinder'
would be lowered onto the soil and the mixing blades started,
moving through the depth in an up and down motion, while
chemicals are introduced. An induced draft fan would draw the
contaminated air from the container into an air pollution control
device and exhaust the treated air to the atmosphere. Because
there is potential for causing substantial VOC emissions, the
contaminated air must be treated by carbon adsorption or by
another treatment process that is equally effective, and meet the
criteria in Section V.D. At the completion of mixing at one
location, the blades would be withdra~n and the cylinder removed.
The cylinder would then be operated adjacent to and overlapping
the previous cylinder. This would be repeated until the entire
area is treated.
.
. .
The f~rmulations and ratios of reagents used for the S/S process
will be established to provide permanent treatment, substantially
reduce release of contaminants due to leaching, substantially
reduce permeability, and to assure long term durability of the
solidified material.
EPA is currently undertaking a treatability study on
approximately ten binders being considered for use in S/S at
Midco II. Those binders selected for use at the Facility must
meet the below listed Minimum Performance Standards. In
addition, based on the results of the treatability study, EPA may
establish Final Performance Standards that are more stringent
than or supplementary to the Minimum Performance Standards.
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21
MINIMUM PERFORMANCE STANDARDS
STABILIZATION OF METALS
using the synthetic Precipitation Leaching Procedure (SPLP)
test (method 1312 of SW-846 using extraction fluid #1) the
. following percentage reduction in the leachate
concentrations shall be attained using the formula:
SPLP treated X DF / SPLP ~aw waste
X 100
SPLP treated = concentration of constituent (i) in the
leachate from sample treated by S/S
DF =dilution factor = (weight of waste being treated +
weight of S/S blend added to that waste) / (weight of
waste being treated)
~I
SPLP raw wastf = concentration of constituent (i) in the
leachate trom untreated waste sample
Alternatively, the SPLPtr~t~ can be reduced to the
following Concentration L~m~ts. If a parameter in the
untreated sample is below its Concentration Limit listed
below, no further reduction in leachate concentration is
required, although the treated sample should not increase in
leachate concentration to above the Concentration Limit. .
CONSTITUENT PERCENTAGE CONCENTRATION
REDUCTION LIMIT ( ua /1)
arsenic 90 502
barium 90. 20002
cadmium 95 52
chromium 95 1002
copper . 95 433
lead 99 152
nickel 95 1002
2 These values are from the'final' or proposed Primary Maximum
Contaminant Standards, 40 CFR Part 143.
3 This value equals the 4-day average fresh water ambient
water quality criteria for copper for protection of aquatic life
times 3.6 at a hardness equal to 100 mg/l. The 4-day average fresh
water ambient water quality criteria is from Ambient Criteria for
Water 1986, EPA 440/5-86-001. The factor 3.6 is the estimated
factor for dilution of the ground water by the surface water at
Midco II.
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22
vanadium
zinc
90
90
233'
11505
STABILIZATION OF ORGANICS
..
Using total waste analyses (using methylene chloride
extraction for semivolatile organics, and methanol
extraction for volatile organics), a 50% reduction in
concentrations shall be attained based on total waste.
analyses of the sample of untreated waste (TWAralif 1if8ste) and
the sample treated by S/S (TWA treated) calculated in
accordance with the formula: TWA treated X DF / TWA ralif vaste X
100 for the following compounds:an'thracene: bis(2-
ethylhexyl) phthalate: ethyl benzene; fluoranthene:
naphthalene: phenanthrene: phenol; toluene: xylene.
PHYSICAL TESTS
:.t
i. Using method EPA 9100 from SW-846 (constant head, tri-
axial with back pressure and air free water), the hydraulic
conductivity of the material treated by S/S shall be less -
than or equal to 1 X 10-7. .
ii. using method ASTM D1633-84, the unconfined compressive
strength of the material treated by S/S shall be greater
than 50 psi.
iii. Using ASTM D4843, the wet-dry durability test on the
material treated by S/S shall result in less than a 10%
weight loss.
iv. using ASTM D4842, the freeze-thaw durability test on
the material treated by S/S shall result in less than a 10%
weight loss.
. .
D.
Requirements for Air Emissions:
1.
Air emissions from the S/S system and from any SVE using the
S/S system shall be controlled using carbon adsorption or
4 This value was calculated for a non-carcinogenic risk index
equal to unity due to vanadium alone using the reference dose and
procedures outlined in Appendix II. .
5 This value is equal to the 24-hour average fresh water
ambient water quality criteria for zinc for protection of aquatic
life times 3.6. The ambient water quality criteria value is from
Oualitv criteria for Water 1986, EPA 440/5-86-001. The factor 3.6
is the estimated dilution of ground water by the surface water at
Midco II.
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~
23
2.
another treatment process that is equally effective.
Air emissions from the (i) ground water treatment, (ii) the
soil S/S, (iii) SVE using the S/S system, or (iv) SVE
separate from the S/S system shall be controlled to the
extent necessary to assure that each operation does not have
the potential to result in exposures to a hypothetical
resident located at the Facility boundary that would cause
an estimated cumulative, incremental, lifetime carcinogenic
risk exceeding 1.0 X 10.7, or from causing a non- ,
carcinogenic risk index greater than 1.0. The risk levels
will be calculated in accordance with the procedures
outlined in Attachment V. Ambient air monitoring and air
emission monitoring shall be conducted to determine whether
this criteria is being met. The air emission monitoring
data shall be input into an air model to estimate the
potential exposure rates in order to determine whether
controls such as carbon adsorption or other controls will be
required for the emission sources. For the soil S/S system
and SVE using the S/S system such controls (if any) shall be
in addition to the controls required by paragraph D.l.
Since there are multiple operations that cause air emissions
as well as fugitive sources that can not be controlled, each
operation that can be controlled must be controlled to the 1
X 10.7 risk level to assure that the total risk will be less
than 1 X 10-6. In addition, since some nearby residents and
workers may have already been exposed to the chemicals at
Midco I during its operation, it is imperative that this
emission criteria be met.
3.
In addition to the requirements of paragraphs 1 and 2 above,
if cumulative emissions of VOCs as defined under the Clean
Air Act from all operations at the Facility other than
excavation exceed 3 pounds per hour, ,carbon adsorption or
another technology that i~ equally effective shall be used
to control air emissions from the ground water treatment
system and all SVE.
4.
Air emissions must be monitored and controlled to the extent
necessary to comply with applicable OSHA regulations, and
applicable state of Indiana air regulations, including Title
326 Indiana Administrative Code 6-4'for fugitive dust.
5.
The effective stack height for air emissions from the ground
water treatment, S/S, and SVE must be at least 30 feet above
ground level.
For any carbon adsorption unit that is being or has been
used for control of air emissions for the ground water
treatment system, the S/S system or the SVE conducted with
6.
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24
the S/S system, access to the unit shall be restricted
within 3 feet of the unit. For any carbon unit that is
being or has been used for control of air emissions for SVE
conducted as a separate operation from the S/S, access to
the unit shall be restricted within 10 feet of the unit.
..
E. Handling and Treatment of Surface Sediments and Soils Beneath
the Sediments: .
The surface sediments in areas outlined in Figure 2 will be
excavated to a depth that will leave the soils below the
excavation less than the following soil CALs:
cumulative lifetime carcinogenic risk = 1.0 X 10.5
cumulative chronic non-carcinogenic index= 1.0
;.I.
These sediments and soils will be consolidated on-site and
treated by S/S along with the subsurface soils.
F. Site Cover, Access Restrictions, Long Term Monitoring, and
Further Remedial Actions:
For Alternative 10, a cover shall be installed over the Minimum
Cover Boundary outlined in Figure 2 following the soil treatment
outlined in section II.C. above. This cover will be extended
over Area C shown in Figure 2 if the results of sampling in. that
area indicate that the area-wide risk using the arithmetic
average of the soil sampling results (see Appendix III) exceeds
the soil CALs in Section V.E using the risk calculation
procedures in Appendix IV. This cover shall meet or exceed the
requirements for RCRA Subtitle C closure. This cover shall be
designed to provide long term minimization of infiltration,
minimize maintenance, 'promote drainage, and minimize erosion.
These requirements will be deemed satisfied by a cover which
consists of multiple layers including:
a top layer consisting of
inch soil layer comprised
'surface slope of at least
percent;
a vegetated component, and a 24
of topsoil and/or fill soil with a
3 percent" and not more than 5
a geofilter in between the upper layer of soil and the
. middle layer of drainage material;
a drainage layer of either 12 inches of soil with
hydraulic conductivity of 1. 0 X 10-2 em/see or a
geosynthetic material with equivalent performance
characteristics, and with a final bottom slope of
percent;
a minimum
at least 3
.
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25
..
a low permeability layer with 24 inches of compacted soil
with a maximum in place saturated hydraulic conductivity of
1. 0 X 10-7 em/sec.; and
Details of the site cover design shall also be consistent
with the EPA Guidance entitled TECHNICAL GUIDANCE DOCUMENT
EPA/530-SW-89-047 (Julv 1989) FINAL COVERS ON HAZARDOUS
WASTE LANDFILLS AND SURFACE IMPOUNDMENTS.
Access restrictions will be imposed including installation of a
six foot chain link fence, warning signs and possible deed
restrictions. Deed restrictions limiting development and the
placement of new wells will be sought voluntarily from owners or
.compelled to the extent authorized under any applicable local and
State laws.
:.t
As in Alternative 8, the final site cover and access restrictions
must be consistent with hazardous waste landfill closure
requirements of the RCRA (40 CFR 264.111, 264.116, 264.117, and
264.310).
Following attainment of ground water CALs, ground water
. monitoring will continue for at least 15 years. The ground water
monitoring must be: consistent with the substantive requirements
for ground water monitoring in 40 CFR 264.98, and where necessary
264.98(g) and 264.99.
If a ground water CAL is exceeded during this period due to a
release from the Midco II site, the site cover shall be upgraded
or repaired as needed; operation of the ground water pump'
treatment and underground injection system will be reinitiated;
and steps will be taken to meet the ground water CALs. These
actions must be consistent with the substantive requirements of
40 CFR 264.100 (except that the relevant ground water protection
standards shall be the ground water CALs as defined in this ROD
rather than concentration limit$ specified pursuant to 40 CFR
264.92).
G. Other ARARs and Applicable Regulations included in
Alternative 8:
1. The requirements of Executive Order 11990, Prote~tion of
Wetlands, 40 CFR 6, Appendix A; and Clean Water Act section 404,
40 CFR 230 and 231 shall be met. contaminated wetlands will be
replaced off-site at an appropriate ratio. This may be .
undertaken as part of an agreement between PRPs and the natural
resources trustees.
2. The area of remediation must comply with the Migratory Bird
Treaty Act.
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-
26
.
3. Any residuals (such as spent activated carbon) from the
ground water or s~il treatment processes shall be considered a
RCRA hazardous waste.6 Therefore, these residuals must be
stored on site, and disposed of or treated on-site or off-site in
accordance with RCRA regulations, including the LDRs in 40 CFR
268, and 40 CFR 264 Subpart X for residues that are sent off site
to be regenerated. It is possible that metals sludge from the
ground water treatment process cquld be treated by S/S on-site,
if Land Disposal Restriction requirements are met.
~
Any debris (such as tree trunks or crushed drums that can not be
properly incorporated into the solidified mass) encountered
during the S/S process or during excavations must be properly
handled and stored on-site, and properly disposed of off-site or
contained under the final cover if degradation of the material
will not cause site cover maintenance problems. Any
containerized or drummed liquid wastes encountered during the
remedial actions s~all be properly stored and properly disposed
of off-site.
Any off-site transportation, treatment, or disposal must be in :
compliance with DOT and RCRA requirements, and EPA's Off-Site
Policy.
VI.
SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
This Section updates the evaluation in section IX of the 1989
ROD. The 1989 ROD justified the elimination of alternatives
other than Alternatives 7 and 8. It is now known that
Alternative 7 should not be further considered. Therefore, this
evaluation will only compare Alternative 8 to the new Alternative
10.
. .
The following tabl~ compares some of the critical elements of
Alternative 10 with Alternative 8.
6 The contaminated ground water
following RCRA listed hazardous wastes:
F007, FQ08, F009.
and soil contains the
FOOl: F002, F003, FOOS,
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AREA OF COMPARISON
MEANS TO ADDRESS GROUND
WATER CONTAMINATION
GROUND WATER CALS
MEANS OF GROUND WATER
DISPOSAL
:.I
GROUND WATER TREATMENT
REQUIREMENTS FOR
COMPLIANCE WITH RCRA
PRIOR TO DEEP WELL"
INJECTION
27
ALTERNATIVE 8
ALTERNATIVE 10
GROUND WATER
EXTRACTION SYSTEM
CR7 = 1 X 10-5
NCRIS = 1. 0
PMCLS9
AWQC'O X 3.6
NO CHANGE
NO CHANGE
DEEP WELL INJECTION,
OR INJECTION INTO THE
CALUMET AQUIFER IN A
MANNER THAT WILL NOT
SPREAD THE SALT PLUME
RCRA LAND DISPOSAL RCRA DELI STING (6.3
RESTRICTIONS (BEST TIMES HEALTH BASED
DEMONSTRATED LEVELS", MACs)
AVAILABLE TECHNOLOGY)
(LDRs)
NO CHANGE
7 Cumulative Lifetime Carcinogenic Risk calculated for each
ground water sampling location using the assumptions and procedures
in Appendix II. .
8 Cumulative non-carcinogenic risk index calculated for each
ground water sampling location using the assumptions and procedures
in Appendix II,
9
Primary Maximum Contaminant Levels (40 CFR 141).
10 Chronic Ambient Water Quality Criteria for aquatic life.
The AWQC values used ~n this ROD Amendment are listed in Appendix
II.
l' Health-Based Levels (HBLs) are concentrations of hazardous
constituents that are used in the RCRA program for making decisions
regarding whether a waste that is regulated as a hazardous waste
under RCRA because it is listed under 4Q CFR Part 261, Subpart D
can be delisted so that it is no longer regulated as hazardous
waste under RCRA because it is listed. In a delisting petition, it
must be demonstrated that the HBLs will be met in a hypothetical
receptor well. The HBLs are set at concentrations of constituents
that provide protection for drinking water usage (Maximum
Contaminant Levels from 40 CFR Part 141 are the HBLs when
available, otherwise the HBL is set at the 10-6 risk level or the
level that will not cause a non-carcinogenic risk assuming that 2
liters per day is ingested over a 60 year lifetime). See Section
V.A.
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MEANS TO ADDRESS
PRINCIPAL THREATSrROM
SOILS
.
:~t
MEANS TO ADDRESS RISKS
FROM SOILS THAT ARE .
ABOVE THE WATER TABLE
AND THAT PRESENT A LOW
LONG TERM THREAT VIA
GROUND WATER AND
DIRECT CONTACT
SOIL TREATMENT ACTION
LEVELS
ESTIMATE OF QUANTITY
OF SOIL TO BE TREATED
28
NO CHANGE EXCEPT
SVE WILL BE
REQUIRED WHERE
SjS IS CONDUCTED.
TREAT BY SjS (AND
SVE IF NECESSARY TO
PROTECT GROUND
WATER). SjS AND SVE
WILL PROVIDE
PERMANENT TREATMENT
OF HIGHEST CONTAMINATED
AREAS LOCATED ABOVE
AND BELOW THE WATER
TABLE. SjS MATERIAL
WILL BE PROTECTED WITH
A SITE COVER, AND
MONITORED AND
MAINTAINED OVER LONG
TERM.
TREAT BY SjS (AND
POSSIBLY SVE). LONG
TERM MAINTENANCE &
MONITORING OF THE
SjS WOULD BE
REQUIRED. THIS
WOULD PROVIDE SOME
PERMANENT TREATMENT,
REDUCE LEACHING TO
GROUND WATER, AND
REDUCE DIRECT
CONTACT THREAT BY
SjS AND COVER OVER
THE SjS.
CONSTRUCT A RCRA
COVER. LONG TERM
MAINTENANCE AND
MONITORING OF THE
COVER WOULD BE
REQUIRED. AS LONG:
AS COVER IS
MAINTAINED WILL
SUBSTANTIALLY
REDUCE LEACHING
AND THE DIRECT
CONTACT THREAT
BY COVERING WITH
A FIVE FOOT THICK
COVER.
CR = 1 X 10-6
NCRI = 1.0
AT A MINIMUM TREAT
MINIMUM AREA FOR
TREATMENT IN FIGURE
2. OUTSIDE THIS
AREA:
CR = 5 X 10-'
NCRI = 5.0
18,300 CUBIC YD.13
- .
35,000 CUBIC .YD.12
is
12 This estimate is probably biased high because it
partially based on unreliable arsenic data (see section III).
13 This is a very rough estimate that assumes 50% more than
the minimum amount will be treated as a result of further sampling.
-------
PERFORMANCE STANDARDS
FOR S/S
CRITERIA FOR SVE
:.t
MEANS TO ADDRESS RISKS
FROM SOILS BELOW THE
WATER TABLE THAT WILL
NOT BE TREATED BY S/S
MEANS TO ADDRESS
CONTAMINATION OF
SURFACE SEDIMENTS
SOIL/SEDIMENT CALS
AIR EMISSIONS CRITERIA
SITE COVER
SPECIFtCATIONS
ACCESS RESTRICTIONS,
DEED RESTRICTIONS,
LONG TERM MONITORING
29
FOR IN-SITU S/S
ASSURE ATTAINMENT
OF GROUND WATER
CALS.
CONDUCTED PRIOR TO
S/S TO THE EXTENT
NECESSARY TO MEET
GROUND WATER CALS
BASED ON MODELLING
SOILS WILL
GRADUALLY BE
REMEDIATED BY THE
GROUND WATER
EXTRACTION OPERATION.
EXCAVATION AND ON-
SITE S/S
CR = 1 X 10-5
NCRI = 1. 0
CR = 10-7 TO
NEAREST RESIDENTS
AND WORKERS FOR EACH
EMISS~ONSOURCE, TO
ASSURE ATTAINMENT' OF
.CR = 10-6 OVERALL.
FOR IN-SITU S/S
DEPENDED ON RESULTS
OF S/S
REQUIRED
SPECIFIC
PERFORMANCE
STANDARDS FOR
BOTH INORGANICS
AND ORGANICS BASED
ON TESTS ON S/S
WILL DEFINITELY BE
CONDUCTED IN ALL
AREAS BEING S/S'ed
TO REDUCE VOCs IN
SOILS BY 97% IF
CONDUCTED AS A
SEPARATE OPERATION,
AND BY 90% OF
CERTAIN VOCs IF
CONDUCTED WITH IN
SITU S/S EQUIPMENT.
NO CHANGE
NO CHANGE
NO CHANGE
SAME AS ALT. 8
CRITERIA, PLUS NO
GREATER THAN 3
LBS PER HOUR, AND
EMISSION CONTROLS
REQUIRED ON S/S
SYSTEM.
CONSISTENT WITH
RCRA SUBTITLE C
NO CHANGE
-------
AN ESTIMATE OF THE
PRESENT WORTH
30
$19 MILLION1'
$13 MILLION15
...
In Alternative 10 the extracted ground water must meet the MACs
prior to deep well injection rather than meet the LDRs, which
were expected to be used in Alternative 8. Treatment to the MACs
is as protective or more protective than treatment to the LDRs
because generally the MACs are more stringent for the more toxic
compounds. However, treatment to the LDRs would be more .
difficult. Modelling will be conducted to confirm that injection
of extracted ground water meeting the MACs (into the lower Mount
Simon Formation) will be protective of drinking water aquifers.
In Alternative 10, treatment beyond the MACs will be conducted if
necessary to be protective of drinking water aquifers. See
Section V.A.
~I
In Alternative 10, SVE will definitely be conducted as described
in Section V.C.2 prior to the treatment by S/S. In Alterative 8,
SVE would be been required only if necessary to assure that
leaching from the S/S material would not cause an exceedance of
the ground waterCALs.
In Alternative 10" areas of the site having soils located above
the water table with calculated risks below CR = 5 X 10.4 and
NCRI = 5.0, will be covered consistent with RCRA Subtitle C
requirements without being treated by S/S or SVE. However, the
site cover will not be installed until the ground water
extraction system has operated for a few years. Such operation
may further reduce VOCs prior to installation of the site cover.
EPA considers that following treatment of the highly contaminated
areas, the site cover will provide overall protection to CR = 1 X
10.6 and NCRI =1.0 levels. The cover will be multi-layered and
five feet thick. The cover will substantially reduce the
infiltration intQ the soil and, therefore, reduce the
contamination of the ground water. It will provide an effective
barrier to direct contact while, it is maintained. During its
operation any contaminants leached from the soils would be
recovered by the ground water extraction system. In the unlikely
event that long term leaching causes the ground water to exceed
the ground water CALs, the ground water extraction system would
continue to operate or be reactivated so that protection from any
, .
14 This is a very rough cost estimate from the Feasibility'
Study and is likely biased high because it was partially based on
unreliable arsenic. data for the extent of soil treatment (see
Section III).
1S This is a very rough estimate based on the assumption that
50% more than the minimum amount of soil is treated, that SVE
increases the cost of S/S by 50% , and certain ground water
treatment assumptions.
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31
ground water threat is assured.
In Alternative 8, 'compared to Alternative 10, VOCs in the lower
contaminated areas may have been further reduced by operation of
the SVE system, and the mobility of metals and other organics
reduced by the S/S. However, as mentioned before for Alternative
10, any additional leachate from the soils would be recovered in
the ground water extraction system so that protection from any
ground water threat is assured. Alternative 8 may provide some
additional protection compared to Alternative 10 from the direct
contact threat in case the site cover is severely disturbed in
the future because the low contaminated soils would be treated by
S/S. However, it appears to be very unlikely that a five foot
site cover would be so completely removed, and even if it was
Alternative 10 provides for treatment of the most highly
contaminated soils so that only the lesser contaminated soils
would remain.
:.t
Since the
developed
treatment
have been
time of the 1989 ROD, specialists in SjS treatment have
specific tests for testing the permanence of SjS
for inorganics and organics. Therefore, these tests
incorporated into Alternative 10 of this ROD Amendment.
Because of the difficulty in reasonably modelling the impact of
VOCs on the ground water, it was decided to simply require SVE to
provide substantial removal of the VOCs prior to treatment by
SjS. The criteria is less stringent for conducting SVE with the
in-situ SIS equipment compared to using a separate operation
because it is much more difficult to monitor the removal of VOCs
from the soils using the in-situ S/S equipment because the soil
is treated by S/S immediately after the SVE operation.
The three pounds per hour limit on air- emissions for Alternative
10 was added to be consistent with EPA's policies on control of
photochemical oxidants. Because the emissions from the in-situ
S/S operation could be substan~al' and unpredictable, it was
decided that air emissions from the in-situ S/s system must be
controlled.
A. Thre~hold criteria: protection of human health and the
environment: and attainment of applicabl~, and relevant and
appropriate requirements (ARARs)':
Both Alternatives 8 and 10 would be protective of human health
and the environment, by extraction and treatment of the ground
water, by treating the highly contaminated soils and sediments,
and by cover installation. Both alternatives are expected to
protect aquatic life in surrounding surface waters from hazardous
substances from the Midco I site including attainment of Ambient
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32
Water Quality Criteria for aquatic life'6 and restore the
Calumet aquifer to drinking water quality'7 including attaining
the Primary Maximum contaminant Levels.
~
Both include deep well injection of the treated ground water (or
reinjection into the Calumet aquifer in a manner that will not
spread the salt plume). Both would comply with the RCRA LDRs
prior to injection of the ground water: Alternative 8 by
treating to LDR treatment standards; and Alternative 10 by
delisting. Both include soil treatment by S/S and SVE. Both
include excavation and S/S of contaminated sediments. Finally
both include installation of a cover and site access
restrictions.
~
While Alternative 8 includes treatment of a greater volume of
soils than Alternative 10, the level of protection provided by
Alternative 10 is not considered to be significantly different
from the level of protection provided by Alternative 8 because
low level contaminated soils will be contained by an effective
cover that is consistent with RCRA subtitle C closure
requirements, and access to the site will be restricted.
Furthermore, the additional soil treatment in Alternative 8 would
not allow unrestricted future usage of the site because the S/S
material and site cover would require long term monitoring and
maintenance.
Under Alternative 10, if it is determined that it is technically
impracticable from an engineering perspective to attain the
ground water CALs by a ground water extraction system,
contingency measures may be implemented (see Section V.B). These
contingency measures will maintain protection of human health and
the environment by institutional controls, by attaining the
lowest achievable levels in the ground water, and by containment
measures, as appropriate. If it is demonstrated that some
primary MCLs, which are used in the ground water CALs, can not be
attained in some portions of the aquifer due to technical
impracticability, these"ARARs will be waived provided that
appropriate contingency measures are implemented.
16 Except possibly for the Ambient Water Quality Criteria for
solids (dissolved) and salinity, for which a ground water CAL is
not being applied since adjacent sources of this contaminant exist
and are not being remediated.
17 Except for total dissolved solids, chlorides, sodium and
potassium, for which a ground water CAL is not being applied since
adjacent sources of these contaminants exist and are not being
remediated.
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33
B. Balancing Criteria: long term effectiveness and permanence;
reduction in toxicity mobility and volume; short-term
effectiveness; implementability; and cost:
~
The short term effectiveness of Alternative 10 is expected to be
essentially the same as Alternative 8. The pump, treatment and
injection system will be installed first in Alternative 10.
Access to the site will be controlled; so the delay in the soil
treatment will not cause any health impact. For both
Alternatives, VOC air emissions during the remedial actions may
be the short term impact of most concern. These emissions should
be controllable using carbon absorption or another treatment
process that is equally effective.
Both Alternative 8 and 10 employ treatment technologies--ground
water extraction and treatment, 5j5, and 5VE--that are expected
to perform to substantially reduce the toxicity, mobility, or .
volume of hazardous substances at the Midco II site. Both
Alternatives 8 and 10 provide for long-term effectiveness and
permanence through soil treatment by 5j5 and 5VE, by ground water
extraction and treatment, deep well injection of treated ground
water, site cover, long term maintenance, and ground water
monitoring.
While Alternative 10 will result in treatment of a lower volume
of soils than Alternative 8, Alternative 10 provides for a
reduction of the toxicity and mobility of the more highly
contaminated soil at Midco II. Furthermore, the additional soil
treatment in Alternative 8 will not result in a reduction in the
long term monitoring or maintenance requirements nor allow
unrestricted future usage of the site. In the context of
conditions at this particular site, the use of engineering
controls such as site cover coupled with long-term (permanent)
maintenance and monitoring of the site cover and ground water to
address any remaining risks posed by soils with low level
contamination is consistent with EPA's expectations for remedy
selection regarding treatment of principal threats and use of
controls for lower level threats as set forth in 40 eFR
300.430(a) (1) (iii) of the National Contingency Plan promulgated
on March 6, 1990.
Alternatives 8 and 10 are identical in .lmplementability in most
respects, and no major-problems in implementation are expected.
Very rough estimates of the costs of Alternative 8 and
Alternative 10 in millions of dollars are compared in the
following Table.
,
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34
CAPITAL ANNUAL O&M PRESENT WORTH
Alternative 8 12 0.73 19
Alternative 10 9 0.66 13
.
Typically cost estimates in the Feasibility Study are expected to
have an accuracy of plus 50% to minus 30%. There is more than
the usual amount of uncertainty 1n the costs for both
Alternatives 10 and 8. However, Alternative 10 may be
considerably less expensive than Alternative 8 primarily because
most likely less soil will be treated, qround water treatment
requirements may be reduced, and the sequence of implementation
. of remedial actions (see sections V.C.l, V.C.2 and V.F) will be
chanqed. Because the risk reduction and reduction in toxicity or
mobility of the additional treatment required in Alternative 8 is
small, it is not considered to be cost effective compared to
Alternative 10.
~
Time for completion of the project depends on how fast the qround
water CALs are attained. All other portions of the project are
expected to be completed in no more than six years.
C. Modifyinq criteria: support aqency acceptance: community
acceptance:
The Indiana Deparment of Environmental Manaqement, involved in
the process that lead to this ROD Amendment, formally concu+red
with u.s. EPA's remedy selection in this ROD Amendment in a
letter dated January 6, 1992.
U.S. EPA prepared a Draft Proposed ROD Amendment and a fact sheet
exp1aininq the ROD Amendment, and held a public comment period on
the proposed Amendments from February 7 throuqh March 14, 1992.
The Proposed Plan was'mai1ed to. approximately 300 persons in the
communities near Midco II. The Draft Proposed ROD Amendment was
available for review in the Hammond Department of Environmental
Manaqement and at the Gary Public Library. The Administrative
Record for this action was available for review at the Reqion V,
U.S. EP.A, Chicaqo office. A public meetinq was held on the
proposed ROD Amendment on February 20, 1992.
One comment on the proposed ROD Amendment was received durinq the
public meetinq, and written comments were received from the Grand
Calumet River Task Force and from u.s. Reduction Co. u.s. EPA's
full response to these comments are included in the
Responsiveness Summary, which is Appendix VI of this ROD
Amendment, and is an inteqra1 part of this ROD Amendment.
The comment from the Grand Calumet River task force expressed
concern about the public and environmental protectiveness of the
-------
35
deep well injection operation and recommended use of a
desalination plant for final disposal of the salt contaminated
ground water, instead of deep well injection. In response to
these comments, u.s. EPA describes the importance of the cost
effectiveness of the remedy, and the precautions that will be
taken to assure that the deep well injection process is conducted
safely and in a manner that will be protective of human health
and the environment.
~
The comment at the public meeting had to do with the completeness
of the remedy apparently related to soil treatment by
sOlidification/stabilization and disposal of ground water by deep
well injection. In response to this comment u.s. EPA explained
.the basis for its belief that treatment by sOlidification/
stabilization would be effective, and that the deep well
injection process would be conducted in a manner that will be
protective of human health and the environment.
The comments from u.s. Reduction had to do with the completeness
of the Administrative Record for the risk assessment, selection
of deep well injection, and selection of sOlidification/ .
stabilization. u.s. Reduction also recommended that additional:
investigations be conducted. In response to these comments, u.s.
EPA described in detail how the Administrative Record supports
the risk assessment, and the selection of the deep well injection
procedure, and sOlidification/stabilization.
No changes were made to this ROD Amendment following review of
the public comments other than incorporating this section of the
Summary for Record of Decision Amendment and the Responsiveness
Summary, indicating that the State of Indiana has concurred in
the remedy selection, and removing a reference in the Declaration
that the administrative record would be updated at a later date
to address pUblic comments.
. .
VI.
STATUTORY DETERMINATIONS
Based on the description and evaluation of alternatives in the
ROD Ame~dment, EPA selects Alternative 10 for implementation at
Midco II. This Alternative is described..in Section IV of this
ROD Amendment.
o
Alternative 10, including the provision of contingency measures
in case it is technically impracticable to attain ground water
CALs, will be protective of human health and the environment, and
will be cost effective. ARARs shall be attained except that some
primary MCLs will be waived in portions of the Calumet aquifer,
provided that it is demonstrated that it is technically
impracticable from an engineering perspective to attain these
standards, and that appropriate contingency measures are
-------
36
implemented. The remedy satisfies the statutory preference for
remedies that employ treatment that reduces toxicity, mobility or
volume as a principal element and utilizes permanent solutions
and alternative treatment technologies to the maximum extent
practicable.
The state of Indiana concurs in the selected remedial actions.
.
Because the remedy will result in hazardous substances remaining
on-site above health-based levels that would allow for
unrestricted use, a review will be conducted within five years
after commencement of remedial actions to ensure that the remedy
continues to provide adequate protection of human health and the
environment.
~
. .
-------
37
APPENDICES TO HIDCO II RECORD OF DECISION AMENDMENT
I.
HEALTH BASED LEVELS FOR RCRA DELI STING FOR MIDCO II
.
II. PROCEDURES FOR CONDUCTING RISK BASED CALCULATIONS AND
DETERMINATION OF GROUND WATER CLEANUP ACTION LEVELS AT MIDCO II
III. PROCEDURES FOR DETERMINING' THE EXTENT OF.TREATMENT FOR
SOILS AND DEBRIS AT MIDCO II
IV. PROCEDURES FOR CONDUCTING RISK BASED CALCULATIONS FOR THE
EXTENT OF SOIL TREATMENT AT MIDCO II
V.
PROCEDURE FOR CONDUCTING RISK CALCULATIONS FOR AIR EMISSIONS
VI.
RESPONSIVENESS SUMMARY
~
. ,
-------
CALs
~
delisting :
E~
F&W
HBLs
IDEM
~
L~
MACs
MCLs
mg/kg
no migration
PCBs
~e
38
GLOSSARY
cleanup action levels.
If a waste fits the definition for a listed.
hazarqous waste under RCRA, it can only be removed
from regulation under RCRA by meeting the
delisting requirements pursuant to 40 eFR 260.22.
united states Environmental Protection Agency.
united states Fish and Wildlife Service.
health based levels used by EPA to make delisting
decisions.
Indiana Department of Environmental Management.
Land Disposal Restrictions under RCRA.
Maximum allowable concentrations. This term is
defined in "A Guide to Delisting of RCRA Wastes
for Superfund Remedial Responses" (9347.3-09FS) to
be the maximum concentration in a waste or in a
leachate from a waste that will still allow the
waste to be delisted.
Maximum Concentration Limits as defined under the
Clean Water Act (40 eFR 141 and 143.
concentration of a constituent in soil expressed
in milligrams of the constituent per kilogram of
soil.
. ,
petition: A petition submitted to EPA pursuant to
40 eFR 268.6 and 148 Subpart C that must
demonstrate that deep well injection of a waste
will not cause migration out of the injection zone
within 10,000 years. EPA approval' of such a
petition is required p~ior to deep well injection'
of a hazardous waste restricted from land disposal
under the LDRs without treatment to the LDR
treatment standards.
, polychlorinated biphenols
Planning Research corporation, Chicago, Illinois.
-------
PRPs
RCRA
RI/FS
MD
SW
S/S
USDW
~
VOCs
WS
39
.
.
potentially responsible parties. These generally
include the site owners, site operators and
entities that disposed of or arranged for disposal
of wastes containing hazardous substances at the
site.
.
.
Resource Conservation and Recovery Act.
Remedial Investigation/Feasibility study.
.
.
Record of Decision.
soil vapor extraction treatment.
solidification/stabilization treatment.
underground source of drinking water as defined in
40 CFR 144.3.
.
.
volatile organic compounds.
Vertical Horizontal Spread model for modelling .'
spread of contamination in the ground water.
. .
-------
APPENDIX I
. .
H!.AI.TH.IASED LEVELS AND SOLD!ILITIES
FOR CONSTITUENTS OF CONCERN IN DELISTING PETITIONS
July 1991
Solubility
(lIg/1)
HBL (in H 0
;. CAS No. Co1!lt)ound (m, /1) R.ef. at 2SiC) R.ef.
83 32 9 Acenaphthene 2 26 3.42 6
67 64 1 Acetone 4 4 1.OxlOIl 6
75 05 8 Acetonitrl1e 2:dO-1 4 1. Ox1011 6
98 86 2 Acetophenone 4 4 5.5x}0:S 15
107 02 8 Acrolein 5xlO-l 37 .SxlO 2
79 06 1 Acrylamlde Trea=ent 42 >lxlOIl 15
Tecpnlque 7.9xlO'
107 13 1 AcrylonitrUe blO- 5 6
309 00 2 Aldrin 2xlO-1I 5 1.8xlO.l 6
62 53 3 Aniline (Benzeneamine) blO-:S 5 3. 5xlO' 2
7440 36 0 Antimony lxlO.z 27
~I 140 57 8 lxlO-:S 26
Araml te
7440 38 2 Arsenic 5xlO-z 13
7440 39 3 larium 1 13
56 55 3 Benz (a) anthracene blO-s 16 S .7xlO-:S 6
71 43 2 Benzene 5x10-:S 14 1.75xlO:S 6
92 87 5 Benzidine 2xl0.7 5 4. Oxl02 6
50 32 8 Benzo(a)1'~ene 2xlO-' 27 1.2xlO-:S 6
205 99 2 lenzo(b)f uoranthene 2xlO-s 8 1.4xlO-2 6
100 51 6 Benzyl alcohol lxlOl 26 4x10' ~17.C) 15
100 44 7 Benzyl chloride 2xlO-' 5 3.3xlO 6
7440 41 7 Beryllium.. b10-' 27
111 44 4 Bis(2-chloroethyl)ether 3xlO-5 5 1.02xlO' 6
108 60 1 BiS(2-ch1oroiSOtro~yl ether) 1. 4 1.7x10:S 6
117 81 7 B1S(2-ethrlhexy )p thalate 3xlO-:S S 4xlO-l 11
75 27 4 Bromodlch oromethane 3xlO-' S 4. 7xlO:S (22.C) 22
74 83 9 Brollomethane . 5xlO-2 4 1. OxlO:S 18
85 6S 7 Butyl benzil phthalate 7 4 2.9 10
88 85 7 . 2-.ec-But~ -4,6-dinltrophenol 7xlO-' 5x101
(Dino.. ) 27 6
7440 43 9 Cac!mium 5xl0-' 42 2. 94x10'
75 15 0 Carbon di.u1fide 4 4 6
56 23 5 . Carbon tetrachloride 5xl0-.J 14 7.57x102 6
57 74 9 Chlord&ne 2xtO.S 42 5. blO;l 6
106 47 8 p-Chloroanlline blO-1 4 3.9xlO 2 . 24
108 90 7 Ch1orobenzene bl0-1 42 4. 66xl0 6
510 15 6 ChlorobenzUau 7xlO-1 4 lxlO' 1
126 99 8 2-Chloro-l,3-butadiene 7xlO-1 3xlOZ 1
(Chloroprene) 26
124 48 1 Chlorodibromomethane 4xIO-' 5 4.4xlO'(22.C) 22
67663 Chloroform hiO-' S 8.2xI0:S 6
95 57 8 2-Chlorophenol 2x10-1 4 2.85xlO'(20.C) 15
107\05 1 3-Chloropropene (Allyl chloride) 2xlO-' 36 lxl0z 15
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2
HEALTH-BASED LEVELS AND SOLUBILITIES
FOR CONSTITUENTS OF CONCERN IN DELISTING PETITIONS
July 1991
So1ubili~y
(mg/l)
HBL (in H 0
CAS No Com~ound lmJ/D Ref. at: 25~C) Ref.
74A0 47 3 Chromium 1x10-1 42
218 01 9 Chrysene 2x10-' 8 1. axlO-' 6
319 77. 3 Cresols 2 4 3.1xlO' 6
57 12 5 Cyanide 2xlO-l 27
94 75 7 2.4-Dich1orophenoxyace~ic 7xlO-z 8.9xlOz
Acid (2,4-D) 42 6
72 54 8 DDD 1xlO-' 5 1x10-; 6
72 55 9 DDE 1xlO-' 5 4x10- 6
50 29 3 DDT 1xlO-' S 5xlO-' 6
2303 16 4 Diallau 6xlO-' 26 1.4xlOl 6
53 70 3 Dibenz(a,h)an~hracene 7x10-7 8,17 5. OxlO-' 6
:.t 96 12 8 1.2-Dibromo-3-chloropropane 2xlO-' 42 1.0x10' 6
74 95 3 Dibromome~hane 4x10-1 4 1.3x10' 25
84 74 2 Di-n-bu~11 ph~hala~e 4 4 1.3xlO: 6
95 50 1 l,2-Dich orobenzene 6xlO-l 42 1.0xlO 6
106 46 7 l,4-Dichlorobenzene 7. 5xlO-z 14 7.9xlOl 6
91 94 1 3,3'-Dich1oro~enzidine 8xlO-' , S 4 6
7S 71 8 Dichlorodifluoromethane 7 4 2. blOz 6
75 34 3 l,l-Dichloroethane 4xlO-' 26 5. Sxl03 6
107 06 2 1,2-Dichloroethane 5x10-' 14 8. 52xl03 6
7S 35 4 l.l-Dichloroethylene 7xlO-' 14' 2.2Sxl03 6
156 59 2 cis-1,2-Dichloroethylene 7x10-z 42 3. 5xlO' 6
156 60 5 trans-1,2-Dichloro.~hyl.ne 1xlO-l 42 6. 3xl03 6
75 09 2 Dichloromethane 5xlO-3 27 2.0xlO: 6
120 83 2 2,4-Dichlorophenol lxlO-l 4 4.6xlO 6
78 87 5 1.2-Dichloropropane 5x10-' 42 2. 7xlO' 6
542 75 6 1,3-D1chloropropene 2xlO-: 5 2. 8xl03 6
60 57 1 Dieldrin . . 2xlO- 5 1.95xlO-l 6
84 66 2 Diethyl phthalate 3xlOl 4 8. 96xlOz 6
56 S3 1 D1ethLl.t11besterol 7x10.' 26 1.3xlO' 15
60 S1 S D1met oat. 7x10.3 4 2. 5x10' 6
119 90 4 3.3'.D1methoxLbenz1d1ne 3x10-' 26 2xlO' 1,23
119 93 7 3,3'-D1methy1 enz1d1ne 4x10.' 26 7x101 1,23
57 97 6 '7.12.D1methylbenz(a). 1xlO." , 4 . 4xlO.3
anthracene 20 6
105 67 9 2,4.Dimeth~1~heno1 7xlO-l 4 5. 9x10: ,9
131 11 3 Dimethyl p t alate 4x101 26 4. 3xlO 2
99 65 0 1,3-Dinitrobenzene 4x10.' 4 4. 7xlO: 6
51 28 5 2,4-Dinitrophenol 7xlO.z 4 5.6xlO 6
121 14 2 Dinitroto1uene 5xlO-' 5.21 1.32xlO' 6
117 84 0 D1-n-oc~yl phthalate 7xlO-l 26 3 22
123 91 1 1.4-Dioxane 3xlO-' 5 4.31x10' 6
-------
3
. .
HEALTH-BASED LEVELS AND SOLUBILITIES
FOR 'CONSTITUENTS OF CONCERN IN DELISTING PETITIONS
July 1991
Solubil1 ty
(mg/l)
;, HBL (in H 0
CAS No. Co~ound (mill!) Ref. at 25iC) Ref.
122 39 4 Diphenylamine 9x10-1 4 5.76xlOl 6
122 66 7 l.2-D1phenylhydrazine 4xlO-s 5 1. 84xl03 6
298 04 4 D1su1foton 1x10-3 4. 2.Sx101 24
115 29 7 Endo sul fan 2x10-3 4 S. 3xlO-~ 22
72 20 8 Endrin 2x10-' 13 2.SxlO- 22
106 89 8 Epich10rohydrin. Treatment 42 6 .0xlO" 6
- (1-Ch10ro-2.3-epoxypropane) Technique lxlOs
110 80 S 2-Ethoxy ethanol 1xlOl 26 1
100 41 4 Ethyl benzene 7xlO-l 42 1. S2xl02 6
60 29 7 Ethyl ether 2xlOl 4 6. 05xlO' 12,2
:.< 106 93 4 Ethylene dibromide 5xlO-s 42 4.3x103 6
97 63 2 Ethyl methacrylate 3 26 7xl02 1.6
62 SO 0 Ethyl methanesulfonate lxlO-1 28 3. 69xlOs 6
52 85 7 Famphur : lxlO-' 41 1. 43xl02 15
206 44 0 F1uoranthene . 1 4 2. 06xlO-l 6
86 73 7 Fluorene 1 4 1.69 6
16984 48 8 Fluoride 4 39
64 18 6 Formic acid 7xlOl 4 lxlO' 6
76 44 8 Heptachlor 4xlO-' 42 1.8xlO-l 6
1024 57 .3 Hebta~10r epoxide (alpha,
eta. gamma isomers) 2xlO-' 42 3. 5xlO-~ 6
118 74 1 H~xachlorobenzene lxlO-' 27 6. OxlO- 6
87 68 3 Hexach1orobutadiene 4x10-' 5 1.5xlO-l 6
77 47 4 Hexachlorocyclopentadiene 5xlO-z 27 2.1 6
67 72 1 Hexachloroethane 3xlO-s 5 S.OX10l 6
70 30 4 Hexachlorophe.ne lx10-z 4 4x10-3 6
319 84 6 alpha-HCH . 6xlO-1 26 1.63 6
319 85 7 beta-HCH 2xlO-s 26 2. 4xlO-l 6
193 39 5 Indeno(1,2.3,cd)pyrene 2xlO-' 8 S . 3xlO-" 6
78 83 1 Isobutanol lxlOl 4 7 .6xlO" 3
78 59 1 Isophorone 9xlO-s 5 1.2xlO" 15
143 50 0 Itepone 2x10-1 29' 7.6 (24.C). 15
7439 92 1 Lead 1.5xl0-z 44
58 89 9 Lindane (gamma-HCH) 2xlO-: 42 7.8 6
7439 97 6 Ke;-cury 2xlO- 42
126 98 7 Kethac;rlonitrile 4xlO-' 4 2.5xlO" 15
67 S6 1 Kethano 2xlOl 4 >1xlOI 1
72 43 5 Kethoxychlor 4xlO-z 42 4xlO-z~24.C) 24
74 87 3 Kethyl chloride 3xlO-' -26 6.5xlO 6 .
56 49 3 3-Methylcho1anthrene 4xlO-' 30
78 93 3 Methyl eth~l ketone 2 4 2. 6blOs 6
108 10 1 Kethyl i50 utyl ketone 2 4 1.91xlO' 2
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4
HEALTH.BASED LEVELS AND SOLUBILITIES
FOR CONSTITUENTS OF CONCERN IN DELI STING PETITIONS
July 1991
Solublli~y
(mg/l)
HBL (in H 0
CAS No. Co!llt)ound (mill) Ref. a~ 25iC) Ref.
r
80 62 6 Methyl .ethacry1a~e 3 43,26 2. OxlOl 6
298 00 0 Ke~hyl yarathion 9x10.3 4 6xlOl 6
91 20 3 Naph~ha ene 1x10.~ 26 3. 4x10l 15
91 S9 8 .2.Naphthylamlne 4x10. 31 S. 86x10z 6
7440 02 0 NIckel 1x10.l 27
98.95 3 NI~robenzene 2x10.z 4 1. 9x103 6
79 46 , 2.NI~ropropane 4x10.a 26 1. 7x10' 38
924 16 3 N.NI~roso.dl.n.bu~lamlne 6x10.a S 6.7x10:S 1,23
55 1~ 5 N.NI~rosodle~h~lamlne 2x10-' S 4. 1x10' 1,23
62 75 9 N.NI~rosodime~ y1amine 7xio.' S 2x10z 1
156 10 5 N.NI~rosodipheny1amlne 7x10.3 S 4.0x10l 10
621 64 7 N.Ni~rosodi.n.tropy1&111ine 5x10.a S . 9. 9x10:S 1
:.t 10595 9S 6 N.N1~rosome~hy e~hy1amine 2x10.a 26 2x10. 1
100 75 4 N.Nitrosopiperidine 8x10.: 32 >lx10:. 6
930 5S 2 Nitrosopyrrol1d1ne 2x10. S >lx10 6
152 16 9 Octamethy1 pyrophosphoramide 7x10.z 26 >lx101 1
56 38 2 Para~hIon 2x10.l 26 2.4x10l f20.C) 15
608 93 5 Pentach1orobenzene 3x10.z 4 1.35x10. 6
82 68 8 Pentachloron1trobenzene 1x10.l 4 7.llxlO.z 6
87 86 5 Pentachlorophenol 1x10.:S 19 l.4xlOl 6
108 95 2 Phenol 2x10l 4 9. 3xrO. 6
298 02 2 Phorate 7x10.:S 40 Sx10. 18
1336 36 3 Polychlorinated biphenyls 5x10-. 42 3.lx}0.Z 6
23950 58 5 Pronamic!e 3 4 lxlO 1
129 00 0 Pyrene 1 4 1.32x10.1 6
110 86 1 Pyric!ine 4xlO.z 4 4xlO. 1
94 59 7 Safrole 1x10-: 33 1.5x10:S 6
7782 49 2 Selenium 5x10- 42
7440 22 4 Silver - 5x10.z 13
57 24 9 Strychnine and ..1t8 1x10-z 4 1.56x10z 6
100 42 5 STene 1x10-l 42 3x102 15
95 94 3 1, ,4.S-Te~r.ch1orob.nzene 1x10-z 4 6 6
630 20 6 1,1.1.2-Tetrach1oroethane 1xlO-s 26 2 . 9xlO~ 6
79 34 5 .l,1.2,2-Tetrachloroethane 2x10-: 5 2. 9x10z 6
127 18 4 Tetrachloroethylene Sxl,O-, '. 42 1.SxlO 6
58 90 2 2,3,4.6-Tetrach1orophenol 1 4 lxlO' 6
3689 24 5 Tetrae~hyl d1thiopyro. 2x10-z
phosphate 4 3x101 25
7440 28 0' Thallium 2xlO-s 27
108 88 3 ' Toluene 1 42 S. 35x10z 6
95 80 7 Toluene-2,4.diamine 9x10-5 34 4. 77xlO. 6
-------
.
, 5
.
'0. HEALTH-BASED LEVELS AND SOLUBILITIES
FOR CONSTITUENTS OF CONCERN IN DELI STING PETITIONS
July 1991
Solubility
(mg/1)
HBL (in H 0
CAS No. COmDound (m2/1) Ref. at 2StC) Ref.
~
823 40 5 To1uene-2,6-diamine 7 7 1.3xlOs 1
9S 53 4 o-To1uid1ne 1x10-. 26 7x102 1.23
106 49 0 p-To1u1d1ne 2xlO-: 26 7.4x103 (21.C) 15
8001 3S 2 Toxa~hene 3xlO- 42 5xlO-l 6
93 72 1 2,4, -TP (Silvex) SxlO-z 42 1.4xl02 2
75 25 2 Tribromometh&ne (Bromoform) 4xlO-s 5 3. 01xl03 6
120 82 1 l,2,4-Trich1orobenzene 9xlO-3 27 3.0xlO; 6
71 S5 6 l,l,l-Trich1oroe1:hane 2x10-1 14 1.5x10 6
79 00 S l,l,2-Tr1chloroe1:hane SxlO-s 27 4. 5xl03 6
79 01 6 Trichloroethylene Sx10-s 14 1.1xl03 6
75 69 4 Trichlorofluoromethane 1xlOl 4 1.1xl03 6
95 95 4 2.4,S-Trichlorophenol 4 4 1.19xl03 6
~t 88 06 2 2,4,6-tr1chlorophenol 3x10-3 5 8. Oxl02 6
93 76 5 2.4,5-trichloroPhenox)- 4x10-1 2.4xl02(30.C)
&ce1:1c acid (2,4,5-T 4 2
96 18 4 l,2,3-Trichloropropane 2xlO-l 4 4xl03 1
76 13 1 l,l,2-Tr1chloro-l,2,2- lx10s . lxlOl
tr1fluoroethane 4 6
99 3S 4 sym-Tr1n1trobenzene 2x10-s 4 3. Sxl02 2
126 72 7 Tr1s(2,3-d1bromopropy1) 3x10-s 1. 2x102
phosphate 3S 6
7440 62 2 Vanadium 2xlO-l 26
75 01 4 Vinyl chloride 2xlO-s 14 2. 67xl03 6
1330 20 7 Xylene (mbed) 1x101 42 1.98xl02 6
7440 66 6 Zinc 7 26
. .
. .
-------
APPEND:IX :I:I
PROCEDURES POR CONDUCT:ING R:ISK BASED CALCULAT:IONS
PORDETERX:INAT:ION OP GROUND WATER CLEAN UP
ACT:ION LEVELS AT K:IDCO :I:I
Risk based calculations shall be conducted for each sample.
The calculation shall be the sum of the estimated risks
produced by each constituent in the sample.
The carcinogenic risk based calculation for each sample is
simply the summation of a lifetime averaged exposure rate via
;.t
ingestion of the ground water for each constituent times that
constituent's oral carcinogenic potency factor (slope factor),
plus the summation of a lifetime averaged exposure rate via
inhalation for each volatile organic compound times that
volatile organic compound's inhalation carcinogenic potency
factor (slope factor).
This is summarized in the following equation:
CRs
OI.
I
IIi
CR.
1:
OIl
OSF.
1
II.
I
= 1: (OI)j(OSF)i + 1: (II)i(ISF)i
= (3.09 x 10-~, l/kg/d) Ci
= (9.74 X 10-2 l/kq/d) Ci
cumulative lifetime carcinogenic risk for a
sample
= Summation of the 'carcinogenic risk from each
constituent detected in the sample.
. -
= Lifetime averaged exposure rate via ingestion
for constituent i
= Oral carcinogenic potency factor (or slope
factor) of constituent i. These are listed
in Table 2 of Appendix IV.
=
Lifetime averaged exposure rate via
-------
2
inhalation for constituent i.
;,
Inhalation carcinogenic potency factor (or
slope factor) of constituent i. These are
listed in Table 2 of Appendix IV.
3.09 X 10-2 l/kg/d = lifetime averaged ground water
.ingestion rate based on the following assumptions:
ISF
=
The ground water intake averaged over 70 years
(25550 days) corresponding to children age 2-6,
with a body weight of 17 kg, and an ingestion
rate of 1 liter of ground water per day for 5
years, equal to 4.2 X 10-3 l/kg/d.
:.I
The ground water intake averaged over 70 years
corresponding to children age 7-12 with a body
weight of 29 kg, and an ingestion rate of 1
liter of ground water per day for 6 years, equal
to 3.0 x 10~ l/kg/d.
The ground water intake averaged over 70 years
corresponding to adults, with a body weight of
70 kg, and an ingestion rate of 2 liters of
ground water per day for 58 years, equal to 23.7
x 10-3 l/kg/d.
(4.2 + 3.0 + 23.7) x 10-3 l/kg/d = 3.09 x 10-2
9.74 X 10-2 l/kg/d = lifetime averaged ground water
exposure rate via inhalation based on the
following assumptions:
Calculate the lifetime ground water inhalation
intake while bathing. In order to do this, it
is assumed that "all subpopulations (adults,
children age 7-12 and children age 2-6) bathe
for 20 minutes each day and stay an additional
10 minutes inside the closed-door bathroom,
where the concentration in the air of the
compound volatilized from the ground water used
for bathing increas~s:from zero to the actual
ground water concentration at the end of the
bathing period, and then decreases to zero
during the additional 10 minutes in the
bathroom. To account for this increase/decrease
in concentration, a factor of 0.38 is used in
the equation to calculate the intake. The
actual ground water concentration can then be
used to calculate the risk. Additional
assumptions include: (1) each bath will consume
200 liters of water; (2) the volume of the
-------
~
3
shower stall is 3 m3; and (3) the volume of the
. bathroom is 10 m3. Also, the volume of air
inhaled per hour is: 0.55 m3 for adults, 0.6 m3
for children age 7-12, and 0.49 m3 for children
age 2-6. .
The inhalation intake can be calculated as:
0.38 [(200 1/3. m3) x (20 min/60 min/day) +
(200 1/10 m3) x (10 min/60 min/day)] x .
[(0.55 m3 x 58 yrs)/(70 kg x 70 yrs) +
(0.60 m3 x 6 yrs)/(29 kg x 70 yrs) +
(0.49 m3 x 4 yrs)/(16 kg x 70 yrs)]
= 9.74 X 10-2 l/kg/d.
C.
1
= Concentration of constituent i in the sample.
~t
The cumulative chronic non-carcinogenic risk index is
calculated as follows:
NIl
= 1: «C;) (3.09 x 10-2 l/kg/d) /ORfD;)
1: «C;)(9.74 x 10-2 l/kg/d)/IRfDj)
+
NIs
z Cumulative chronic non-carcinogenic risk
index.
1:
= Summation of chronic non-carcinogenic risk for
all constituents detected in the sample that
affect the same target organ.
ORfD; = Oral reference dose of constituent i. The
reference doses for this Consent Decree are
listed in Table 2 of Appendix IV.
IRfD; = Inhalation.reference dose of constituent i.
. The reference doses for this Consent Decree
are listed in Table 2 of Appendix IV.
compounds detected below the background concentrations listed
in the Table 1 of this Attachment will not be included in
either the carcinogenic or non-carcinogenic risk based
calculations.
The Primary Maximum Contaminant Levels (MCLs) are from 40 CFR
141.
New primary MCLs will automatically be added to the
-------
4
ground water CALs when they are promulgated.
The Ambient Water Quality criteria (AWQC) for protection of
aquatic life to be used in this Decree are listed in Table 2
,
of this Attachment.
The ground water CALs for the AWQC are
calculated by multiplying the.AWQC from Table 2 by 3.6.
The CAL can not be less than the background concentrations
listed in Table 1, nor be less than the analytical detection
limits.
The analyses shall at least attain the quantification
limits necessary to evaluate attainment of the ground water
:t
CALs.
However, quantification limits below the lowest
practical quant~fication limits listed for each compound in
Appendix IX of 40 CFR 264 shall not be required.
If only one
constituent is detected in a ground water sample that is
calculated to potentially cause a lifetime, incremental
carcinogenic risk of 1 x 10.5 or greater, and an MCL has been
promulgated for this constituent pursuant to 40 CFR 141, then
that constituent will not be used in either the carcinogenic
nor the non-carcinogenic risk calculations, and the CAL for
that constituent will be either the MCL or the AWQC times 3.6,
whichever is less.
-------
- . - --- .
---_.-
..
TABLE 1 OF .. APPENDIX II
8tCI.Ie taTn IACl:IiICI..C Cl:lfCEITUTlC*S *
IS I UCL t5 I Utl
........................ ........................
CCIIIIIPCUI:f .1*0 J 8iCIcA II ~ .i*o I .ilko II
.......................... .......... ........... .......................... .......... ...........
MIIIIC 1.".00 , .'''.01 4.I(T'TL.'."'TAIOME
IMIIII '.1..az 1.01l+C2 mUtll.CIIQ£T ..E
.ITLLI&II TCP..UEWE
CADell'" '.SGE.01 ITIfLRIlZEIIE
C8C11i11111 CIII) '._+00 7.SGE+OO nUMES
CIICJC 1111 CV J) '.DCIE.oo 7.SGE.oo '.MOl
CZI"EI. 2.Sa~1 IISC2.CMLalOET.TL)[T'EI
JIQIi J.".Q3 1.SJE~ I/SC2.CMLOIO/SOPIOPTL)£TN£R
LEAD 5.60(+00 1£lIlTL ALCOtIOL
IWllCiAIII£SE 1.4ar.Q3 4."'E.02 caUOL
:J .IQJlT '.IDE .01 .lTlalEIlZEIiE
IJeaL 5.IOE.01 1 .DE .01 ISOPMOIClijE
ULEII/UM 2.4.0/KETHTL'HEIilOL
SJLVER 4.60£.00 1£1II201C A:IO
TIIA~L/UII 2.'.0ItHLOIOPNEIilOL
vAIle 1111 4.ISE.OO IlUIITIlALEII£
2111t 1.4n.03 2.KETHTL~HTIlALEII£
CTAWIO£ 1.0lt£.01 1.58£.02 ACEUPIITN£II£
VI'TL CIILCIIOE 1.S2£.OO 2.20£.00 4.IfITI0P1I£IIOL
C~Cl0£111A1iE 2.4.DIIi/TI01~U£IIIE
IITIITLEIilE CHLORIDE 1.Sor.00 1.90£.00 OIETIITL'IITkALAT£
a:nOli,! '.90£.00 FLUCII £ 111£
WI:III DISULFIDE 4.IIITIQAIIIIL/II£
1.1.01CNLOIQrTNEIII£ '''EUIIITNIEII£
1.1.DltNLOIQ£TNAII£ D/.II.auTTL'NTIlALATE 3.00£.01
TIAIIS.1.Z.01tNLOIC£TNEIilE . 1.60E .01 6.10£.00 .."T.OSCCI'N£IIITL~IIi£ 2.60£.01
CNUIROFORN '~1i1A:NLOIOPN£'OL
'.2.01CNLOIC£Tk&X£ . .1SCZ.ETITLN£ITL)'"TMALATE 1 .50E.0~
2.IUTAII0Ii£ DI.'.CCTTL'MTkALATE
1,1,1"IJCMLOIOETKAWE '('TACNLOR I'CIIOE
'.2.0/CIILOIaPlaPA.£ UMOAIII£
lIJCIILOIOETIlEII£ O/UOll.
'£IiiZEliE 4.00£.02 £IOIJII
2.II£XANOII£ 'CI.
95 t U:L . 95 perc.,,! IoIR)er confi~, lilli! of tllf ...,r,;. blck;rClll'd IIr~ ",'t,r Conc."trltiO/'l It tlcll .iU.
fr~ th, f.ali~ility Study fOr tach lita.
*All values are given in ug/l.
-------
TABLE 2 OF APPENDIX II
MIDOO I AND II - WATER QUALITY CRITERIA TO BE MET IN THE GROUNO ~ATE~
MIDCO I HIDCO II
---...----.........-.-...........- ...-.-....-.-....................-
.. Surflce Wlter WOC Surflce Water IJQC
Wlter Quality triteril to be 11ft Wlter Quality Criteria to be met
C~ (ug/l> (U;/l) -(ug/l) (ug/l )
..-..-...-.....-.--.-..- ......--..........-... ......... -...........-.-....... .........
ARSENIC '.8Oe+01 1.87E+02 I..80E+01 1. 73E+02
IERYLLIUC 5.30£+00 2.07E+01 5.30e+00 1.91e+01
CADM I UI( 1.20£+00-6.00£+00 II '.68E+00 2.9OE+00-'.'9£+00 II 1.~E+01
CHROMIUM (III) 2.20£+02-1.19£+03 " 8.56£+02 5.58£+02-8.68£+OZ " Z.01E+03
CHROMIUM (VI) 1_10£+01 '.29£+01 1.10E+01 3.96e+01
COPPER 1.30E+01-7.30E+01 " 5.07E+01 3.33E+01-5.28E+01 " 1.20E+02
IRON 1.00E+03 3.90E+03 1.00E+03 3.60E+03
LEAD 3.50E+00".8OE+01 " 1.31£+01 1.'9£+01'2.96E+01 H 5.36E+01
MERCURY 1.20E-02 '.68E-02 1.20E-02 1..3ZE.02
:.I NICKEL 1.68E+OZ-9.57E+02 H 6.55E+02 '.'OE+02-6.9'E+02 H 1.58E+03
SELENIUM 3.50E+01 1.37E+02 3.50E+01 1.26E+02:
SILVER 1.20E -01 '.68E'01 1.20E'01 I..32E-01
THALLIUM '.00E+01 1.56E+02 '.00E+01 1.'I.E+02
ZINC 3.I.2E+02-1.89E+03 " 1.33E+03 8.78E+02'1.37E+03 H 3.16E+03
CTANIDE 5.20£+00 2.03£+01 5.20E+00 1.87£+01
PENTACHLOROPHENOL 1.30E+01 pH 5.0n+01
IIEPTACHLOR EPOXIDE . 3.80£-03 1.48E '02 3.8OE-03 1.3n-02
OIELDRUI 1.90£-03 7.41E-03
ENDRIN 2.30E-03 8.9n-03
Ptis 1.'OE-02 5.'6E'02
WOC . freshwlter chronic wlter quaLity criteria for. the protection of equatic life: II . hardness
de~t. vllues shown Ire for the ra"",e of harctless present iPl surface wlter s~les: pH . vllue is
pH dependtrlt (pH . 7.8 used).
Reference: Quality Criteria for Water
1986. U.S. EPA. EPA 440/5-86-001.
May 1 t 1986.
.
-------
APPENDIX III
PROCEDURES POR DETERMINING
THE EXTENT OP TREATMENT POR SOILS AND DEBRIS
AT XIDCO II
\1
To define the extent of the treatment by S/S and/or .by SVE
outside of the minimum area for treatment outlined in Figure 2,
samples. shall be collected on a square grid with 60 foot centers.
The location of the initial grid point shall be determined by the
random number technique, and the rest of the grid points measured
from the initial point. The grid shall cover the whole soil
sample collection area shown in Figure 2 excluding the minimum
area for treatment. Split spoon samples shall be collected at
each grid point from 1-3 and 4-6 foot depths.
In addition to this grid sampling, one composite sample shall be .
collected from the pile of contaminated soil in the north corner
of Midco II. This composite sample shall be collected using a
three dimensional simple random sampling strategy (Test Methods
for Evaluating Solid Waste. U.S. EPA, SW-846, Volume 2, 1986.)
The following parameters shall be considered in determining
whether the Soil Treatment Action Levels (defined in Section
V.C.2) are exceeded at each sampling point:
METALS: total chromium, chromium (VI), lead, antimony,
nickel, barium, cadmium, selenium, copper, iron, zinc,
vanadium, manganese;
OTHER INORGANICS:
arsenic, cyanide;
VOLATILE ORGANIC COMPOUNDS (VOCs): methylene chloride,
trichloroethylene, tetrachloroethylene, 2-butanone,
acetone, toluene, 1,1,1 trichoroethane, benzene,
xylene, ethyl benzene, methyl isobutyl ketone, 1,1-
dichloroethylene, 1,~ dichloroethylene, vinyl chloride;
ACID/BASE/NEUTRAL FRACTION: benzo(a) anthracene, chrysene,
benzo(b)fluoranthene, benzo(a)pyrene,
indeno(l,2,3)pyrene, dibenz(a,h)anthracene, bis(2-
ethylhexyl) phthalate, diethyl phthalate, di-n-butyl
phthalate, isophorone, phenol;
PESTICIDE/PCB FRACTION: chlordane, aldrin, dieldrin,
polychlorinated biphenyls.
For any of the grid sampling points that exceed the Soil
Treatment Action Levels, either:
(a) The entire area within the 60 foot square centered at the
grid point will be treated in accordance with Section V.C.2;
or
-------
2
(1)
(b) Further sampling and treatment will be conducted as follows:
.
(2)
(3)
~
(4)
The 60-foot square centered at the grid point shall be
subdivided into nine squares measuring 20 by 20 feet.
The center 20-foot square, where the grid point is
located shall be treated in accordance with Section
V.C.2.
samples at 1-3 and 4-6 foot depth shall be collected at
the center of each of the eight surrounding 20 foot
squares. If any of these samples exceed the Soil
Treatment Action Levels, the entire area within these
20 foot squares shall be treated in accordance with
section V.C.2.
samples at 1-3 and 4-6 foot depth shall be collected at
the center of each 20 foot square that is along side a
20-foot square determined to exceed the Soil Treatment
Action Levels based on the previous sampling. If any
of these samples exceed the Soil Treatment Action
Levels, the entire area within these squares shall b~
treated in accordance with Section V.C.2.
The process in (b) (3) above shall be repeated until
each 20 foot square along side a square containing a
sample that exceeds the Soil Treatment Action Levels,
has been sampled, even if this requires sampling of 20-
foot squares that are part of 60-foot squares whose
center grid point sample results are less than the Soil
Treatment Action Levels.
. .
-------
APPENDIX IV
PROCEDURES POR CONDUCTING RISK BASED CALCULATIONS
POR SOILS AND SEDIMENTS AT MIDCO II
Risk Calculations
Risk based calculations shall be conducted for each sample for
,.
both carcinogenic and non-carcinogenic risks.
The calculation
shall be the sum of the estimated risks produced by each
constituent detected in the sample for the ingestion, dermal
contact, and inhalation routes of exposure using a residential
development scenario.
~I
The carcinogenic risk based calculation for each exposure route
shall be the summation of the lifetime average exposure rate 'for
each constituen~ times that constituent's carcinogenic potency
factor
equation:
CRa
CRa
1:
OIj
. DIi
IIi
OSFi
DSFi
This is summarized by the following
(slope factor).
=
1: (OIL (OSFL + 1: (DI) i (DSFL + 1: (IIL (ISFL
= Cumulative lifetime carcinogenic risk for each
sample
= Summation of the carcinogenic risk for each
constituent det~cted in the sample
= Lifetime exposure rate to constituent i via
ingestion
= Lifetime exposure rate to constituent i via dermal
contact
= Lifetime exposure rate to constituent i via
inhalation
= Oral slope factor or carcinogenic potency factor
(CPF) of constituent i
= Dermal slope factor or carcinogenic potency factor
of constituent i
-------
2
ISFj
- I~alation slope factor or carcinogenic potency
factor of constituent i
.
The non-carcinogenic risk based calculation for each exposure
route shall be the summation of the non-carcinogenic risk
indexes for each constituent. ' The non-carcinogenic risk index
is the ratio of the averaged exposure rate divided by the
reference dose.
This is summarized by the following equation:
NI.
= 1: (OCDIj> I (ORfDh + 1: (DCDIhl (DRfDh + 1: (ICDIh(IRfDh
NI.
8 CUmulative chronic non-carcinogenic risk index for
each sample
OCDIj = Chronic daily intake of constituent i for the inges-
tion route of exposure
:.i
DCDIj = Chronic daily intake of constituent i for the dermal
contact route of exposure
ICDIj = Chronic daily intake of constituent i for the
inhalation route of exposure
ORfDj = Chronic oral reference dose
DRfDj = Chronic dermal reference dose
IRfDj = Chronic inhalation reference dose
Constituents that are not detected shall not be included in the
risk calculations.
The chemical analyses shall at least attain
the quantitation limits necessary to evaluate attainment of
soil CALs.
However, quantitation'limits lower than the
detection limits listed in Table 1-7 of the Feasiblity Studies'
for Midco I and Midco II will not be required.
Compounds
detected below background concentrations shown in Table 1 shall
not be used in the risk calculations.
No OSF, 1SF, ORfD or
1RfD is presently available for lead.
Therefore, the soi~
-------
3
treatment action level for lead is set at 1000 mg/kg in the
soil, and the sediment/soil CAL is set at 500 mg/kg.
If NI. exceeds 5.0 for the STALs or 1.0 for the soil/sediment
CALs, the organ specific NI. shall be calculated in a manner
consistent with EPA guidance.
Then the highest organ specific
NI. shall be used to evaluate whether the criteria for soil
treatment is or is not exceeded.
summarized below:
The procedures for the calculations for each exposure route are
:.t
FOR THE INGESTION ROUTE OF EXPOSURE:
CARCINOGENIC RISK CALCULATION
CR,j = 1: (OI)g(OSFh
OIj = (2.34 mg/kg/d) (~)
CRa =
OIi =
OSFi =
Cumulative lifetime carcinogenic risk for each
sample for the ingestion route of exposure
Lifetime expqsur,e rate to constituent i for the
ingestion route of exposure
Oral slope factor or carcinogenic potency factor
(CPF) of compound i. These are listed in Table
2. The CPFs in Table 2 are from the U.S. EPA
"Health Effects Asses.sment Summary Tables",
April 1989, OERR 9200.6-303-(89-2), except for
the carcinogenic polyaromatic hydrocarbons,
which are from the U.s. EPA Health Effects
Assessment Group.
2.34 mg/kg/d = lifetime averaged soil intake based on the
following assumptions:
- The soil intake averaged over 70 years (25550
days) corresponding to children age 2-6, with
-------
'0
4
.
.a body weight of 17 kg, and an ingestion rate
of 0.2 grams of soil per day for 5 years,
equal to 8.4 x 10~ g/kg/d.
- The soil intake averaged over 25550 days
corresponding to children age 7-12, with a
body weight of 29 kg, and an ingestion rate
of 0.1 grams of soil per day for 6 years,
equal to 3.0 x 10~ g/kg/d.
- The soil intake averaged over 25550 days
corresponding to adults, with a body weight
of 70 kg, and an ingestion rate of 0.1 grams
of soil per day for 58 years, equal to 12 x
104 g/kq/d.
(8.4 + 3.0 + 12) x 10~ g/kg/d X 103 mq/g
= 2.34 mg/kg/d
:,i
C,
I
=
Concentration of constituent i in the sample in
milligrams contaminant per milliqram soil.
NON-CARCINOGENIC RISK INDEX CALCULATION
NIli
=
I: (CL(11.8 mg/kq/d) /ORfDi)
NI.i
=
Cumulative chronic non-carcinoqenic risk index
for the ingestion route of exposure
C,
I
=
Concentration of constituent i in the sample in
milliqrams contaminant per milligram soil
11.8 mq/kq/d = Soil intake for children aqes 2-6, based
on a bodyweiqht 'of 17 kg and an ingestion rate
of 0.2' grams of soil per day for five years
ORfDj
= Chronic oral reference dose. The oral
reference doses for this Decree are listed in
Table 2. The RfDs listed in Table 2 are from
the U.S. EPA "Health Effects Assessment Summary
Tabl~s", April 1989, OERR 9200.6-303-(89-2)
-------
5
FOR THE DIRECT CONTACT ROUTE OF EXPOSURE:
CARCINOGENCIC RISK CALCULATION
CR.s
DIj
CR.s
DIj
C.
I
,
DSFj
~I
DFj
=
~ (DIL(DSFL
(CL(DFL(14.S3 mg/kg/d)
..
= CUmulative lifetime carcinogenic risk for each
sample for the dermal contact route of exposure
.. Lifetime exposure rate to compound i for the
dermal contact route of exposure.
= Concentration of constituent i in the sample in
milligrams contaminant per milligram soil
= Dermal slope factor or carcinogenic potency
factor (CPF) of constituent i. These are listed
in Table 2. The dermal CPFs in Table 2 were
adjusted from the oral CPFs by dividing the orai
CPF by the chemical-specific oral absorption
factor that represents the percentage of ingested
chemical that is actually absorbed. The
absorption factors are also listed in Table 2.
= Desorption factor. This is a chemical-specific
value that takes into account the desorption of a
constituent from the soil matrix. The following
desorption factors shall be used: volatile
organic compounds" 0.25; semi volatile organic
compounds = 0.10; inorganics = 0.01.
14.53 mg/kg/d = Lifetime soil to skin adherence based on
the following a~sumptions:
-.
- The soil aclherence averaged over 70 years
(25550 days) corresponding to children age 2-6,
wi th a body weight of 17 kg, an exposed body
surface area of 3160 cm2, .a soil-to skin
adherence factor of 0.9 mg/cm2 (Exposure Factors
Handbook, Technical.' Report, U.S. EPA, 1989,
Contract No. 68-02-4254) of soil per day, fQr
138 days per year, for 5 years, equal to 4.52
mg/kg/d. The exposed body surface area
includes arms, legs and hands (50th percentile,
children aged 3-4, from Exposure Factors
Handbook, 1989).
- The soil adherence averaged over 70 years
-------
.
~I
6
(25550 days) corresponding to children age 7-
12, with a body weight of 29 kg, an exposed
body surface area of 4970 cm2, a soil-to skin
adherence factor of 0.9 mg/cm2 of soil per
day, for 138 days per year, for 6 years,
equal to 5.00 mg/kg/d. The exposed body
surface area includes arms, legs and hands
(50th percentile, children aged 9-10 from
Exposure Factors Handbook, 1989).
- The soil adherence averaged over 70 years
(25550 days) corresponding to adults, with a
body weight of 70 kg, an exposed body surface
area of 3120 cm2, a soil-to skin adherence
factor of 0.9 mg/cm2 of soil per day, for 55
days per year, for 58 years equal to 5.01
mg/kg/d. The exposed body surface area
includes arms and hands (50th percentile
adults from Exposure Factors Handbook, 1989).
NON-CARCINOGENIC RISK INDEX CALCULATION
NIId
NIId
C.
I
DFj
63.25
DRfDj
=
1: (CL (DFL (63.25 mg/kg/d) / (DRfDj)
=
Cumulative chronic non-carcinogenic. index for
the direct contact route of exposure
Concentration of constituent i in the sample in
milligrams contaminant per milligram soil
=
Desorption factor. Use definition previously
provided for the carcinogenic risk calculation.
mg/kg/d = The s~il'adherence corresponding to
children age 2-6, with a body weight of 17 kg,
an e~posed body surface area of 3160 cm2, a
soil-to skin adherence factor_of 0.9 mg/cm2 of
soil per day, for 138 days per year, for 5
years.
=
= Chronic dermal reference dose. The chronic
dermal reference doses for this Decree are
listed in Table 2. The chronic dermal reference
doses listed in Table 2 were adjusted from the
oral reference doses by multiplying the oral
reference doses by the chemical-specific oral
. absorption factor that represents the percentage
of ingested chemical that is actually absorbed.
The oral absorption factors are also listed in
Table 2.
-------
7
FOR THE INHALATION ROUTE OF EXPOSURE:
CARCINOGENIC RISK CALCULATION
CRai
IIi
CRsi
IIi
ISFi
:.I
C"
1
D"
I
VPi
MW.
1
-
1: (IlL (ISFL
(CL (D) i(VP) i (MWL(O. 033)
=
=
CUmulative carcinogenic risk for each sample for
the inhalation route of exposure
Lifetime exposure rate to constituent i for the
inhalation route of exposure
-
=
Inhalation slope factor or carcinogenic potency
factor (CPF) for constituent i. The inhalation
CPFs are listed in Table 2 and are from: U.S.
EPA, 1989, Health Effects Summary Tables, OERR
9200.6-303-(89-2).
=
Concentration of constituent i in the sample in
milligrams contaminant per milligram soil
Diffusion coefficient of constituent i in the
air, in cm2/sec
=
=
Vapor pressure of constituent i, in mm Hg
Molecular weight of constituent i, in g/mole
=
0.033 = (INR) (ET) (EF) (ED) (A)" (p4/3) ( 1000 mala)
(BW) (AT) (h) (u) (w) (L) (R) (T)
INR = Inhalation-rate in m3/hour: 0.76 from 1-6
years; 0.89 from 7-12 years; 0.83 for adults
ET
- Exposure time in hours/day: 21.1 from 1-6
years; 18.3 from 7-12 years; 21.1 for adults
EF
= Exposure frequency "in days/year:
age groups
= Exposure duration in years: 6 years from 1-6
. years; 6 years from 7-12 years; and 58 years
for adults
350 for all
ED
A
= 1 E+6 cm2 (a box 1 meter wide a"nd 100 meters
long)
= Total soil porosity: 0.35
p
-------
c
;.
8
BW = Body weight in kg.: 17 kg from 1-6 year; 29
kg. from 6-12 years; and 70 kg adult
AT
c Averaging time: 25550 days (365 days/year X
70 years)
= Mixing height: 1.83 meters
h
w
= Mixing width: 1 meter
u
= Wind speed: 2.4 meters / sec.
L
c Effective depth of soil
cover:
30 cm.
R
= Gas constant: ; 62,361 mm H9/qmoler'K
T
= Temperature: 290 o:K
'I
NON-CARCINOGENIC RISK INDEX CALCULATION
NI.j
NIli
=
t (CL(DL(VPL(MWL(0.0938) / (IRfDj)
=
CUmulative chronic non-carcinogenic index for
the inhalation route of exposure
Concentration of constituent i in the sample in
milligrams contaminant per milligram soil
Dj, VPj, and MWj are as def ined above
C.
I
0.0938 =
=
(INR) (ET) (EF) (ED) (A) (p4I3) (1000 mala)
(BW) (AT) (h) (u) (w) (L) (R) (T)
INR = Inhalation rate in m3/hour:
olds '.
0.76 for 1-6 year
ET
~ Exposure time in hours/day:
year olds
21.1 for 1-6
ED
Exposure duration in years:
6 years
=
BW
= Body weight in. kg::
17 kg for 1-6 year olds
AT
= Averaging time: 2190 days (365 days/year X 6
years)
A, P, EF, P, h, w, u, L, R, and T are as defined
above
-------
IRfDj
;0
~t
9
=.Inhalation reference dose for constituent i. The
inhalation CPFs are listed in Table 2 and are
from: u.s. EPA, 1989, Health Effects Summary
Tables, OERR 9200.6-303-(89-2).
- .
-------
TABLE 1 OF APPENDIX' 1 V"
MIDCO I AND II - BAC(C~OUNO SOIL CONCENTRATIONS.
95% UCL 95% UCL 9S: UC"
COMPOUND (UII/kg) COMPOUND (UII/kg) COMPOUND e uSl/kg)
-.-.------.----.-.-.... ------...-.- ------.-.-...-.-....-.... .-..-.-.------.-.........-
;,
ALUMINlJ4 8,175,837 1,2-0ICHLOROETHANE 0 DIETHTLPHTHALATE 27.1
ANTIMONY 1,290 2-BUTANONE 6.7 FLUORENE 0
ARSENIC 1',01' 1,1,1-TRICHLOROETHANE 0 ~-NITROSCDIPHENTLAMINE 0
BAR I LJM' 80,'92 1,1,2,2-TETRACHLOROETHANE 0 PENTACHLOROPHENOL 0
IERTLLHJC 0 TRICHLOROETHENE 0 PHENANTHRENE 131
CADMIUM 2,769 BENZENE 0 ANTHRACENE 0
CALCI~ 10,662,TT9 2-HEXANONE 0 Ol-N-BUTTLPHTHALATE 0
CHROMIUM 011) 19,26t1 '-METHTL-2-PENTANONE 0 FLUORAWTHEIiE 2SS
CHROMIUM (VI) 19,260 TETRACHLOROETHENE '0 PTRENE 2'8
C:lBALT 4,197 TOLUENE 2.0 BUTTLBENZTLPHTHALATE 112
COPPER l.8,876 CHLOROBENZENE 0 BENZOCA)ANTHRACENE 158
IRON 13,673,722 ETHYLBENZENE 0 BIS(2-ETHTLHEXYL)PHTHALATE 985
LEAD 1'5,8/.3 STYRENE 0 CHRTSENE 238
:~( MACNESIUM 3,386,93lo TOTAL XTLENES 0 Ol-N-OCTTLPHTHALATE 36.'
MANGANESE 117,133 PHENOL 0 BENZO(B)FLUORANTHENE 2'1
MUOJRT 285 1,'-DICHLOROBEWZEWE 0 IEWZO(K)FLUORANTHENE . 15"
NICKEL 17,3108 2-METHTLPHENOL 0 IENZO(A)PTREWE 137
POTASSIUM 1,002,938 '-METHTLPHENOL 0 INDENoe1,2,3-CO)PTRENE 103
sELENIUM 0 CRESOL 0 018ENZeA,H)ANTHRACENE 0
SILVER "'7 N ITROIENZENE 0 BENZOCC,H,I)PERTLENE 108
SODIUM 81,517 N-NITROSODIPROPYLAMINE 0 ALDRIN 0
THALLIUM 1,'71 I SOPHORONE 0 DIELDRIN 0
TIN 1,581 2,'-DIMETHTLPHENOL 0 ENDRIN 0
VANADIUM 20,553 8ENZOIC ACID 0 ',"-000 29.5
ZINC 312,97' 2,4-01CHLOROPHENOL 0 4,4' -DOT 127
CTANIOE 0 NAPHTHALENE 0 CHLORDANE ',098
METHTLENE CHLORIDE 9.' 4-CHLORO-3-METHTLPHENOL 0 AROCLOR-12'2 0
ACETONE 13_9 2-KETHTLNAPHTHALENE 0 AROCLOR-12,a 0
1,1-DICHLOROETHANE 0 ACENAPHTHTLENE 0 AROCLOR-12S' 0
TRANS-1,2-DICHLOROETHENE 0 ACENAPHTHENE 0 AROCLOR-126D 0
CHLOROFORM 0 DIIENZOFURAN . 0 ',"OOE "'.8
. 951 UCL . 9S percent upper confidence limit of the average background soil concentrations.
Study (both sitts hlvt tht same soil blck;round concentrations)-
From the Feasibility
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TABLE 2 OF APF'~DB(. -IV"
CHEMICAL SPECIFIC RISK FACTORS
~
Chronic Chronic Chronic:
Oral IDhala~ion IDhala~ion Oral Dermal Dermal
CPF-oral RID CPF RfD Ab8orp~ion CPF' RID
CHEMICAL (mr/kr/d)"l (mc/kr/d) (mc/kr/d)"l (mr/kr/d) Fac~or (mr/kr/d)"l (mr/kr/d)
antimony NA 4.ooE-04 NA NA 0.05 NA 2.00E-05
araenic: 1.75E+00 1.00£-03 5.00£+01 NA 0.98 1.n£+00 9.80£-04
barium NA 5.00£-02 NA 1.00£-04 0.10 NA 5.00£-03
berylliu"m NA 5.00E-03 '.40£+00 NA 0.001 NA 5.00E-06
c:admium NA 1.00£-03 6.10£+00 NA 0.06 NA 6.00£-05
c:hromium(III) NA 1.00£+00 NA NA 0.01 NA 1.00E-02
chromium(VI) NA 5.00£-03 4.10£+00 NA 0.05 NA 2.50£-04
manganese NA 2.00£-01 NA 3.00£-04 0.05 NA 1.00£-02
mercury NA 3.ooE-04 NA NA 0.15 NA 4.50£-05
nickel NA 2.00£-02 8.40£-01 NA 0.05 NA 1.00£-03
selemum NA 3.00E-03 NA 1.00£-03 0.60 NA' 1.80£-03
thallium NA 7.00£-05 NA NA 0.05 NA 3.50£-06
tin NA 6.00£-01 NA NA 0.05 NA 3.00£-02
vanadium NA 7.00£-03 NA NA 0.05 NA 3.50£-04
~inc: NA 2.00£-01 NA NA 0.50 NA 1.00£-01
cyanide NA 2.00£-02 NA NA 0.45 NA ~.00£-03
methylene chloride 7.50£-03 6.00£-02 1.40£-02 3.00£+00 1.00 7.50£-03 6.00£-02
acetone NA 1.00£-01 NA NA O.~ NA ~.00£-02
1, I. dic:hJoroethane NA 1.00£-01 NA 1.00£-01 0.70 NA 7.00E-02
1,1- dic:hloroethene 6.00£-01 ~.00£-03 1.20£+00 NA 0.93 6.45£-01 ~.30£-03
c:hloroform . 6.10£-03 1.00£-02 1.1~£-02 NA 1.00 6.10£-03 1.00£-02
1,2 -dichloroethane UO£-02 NA UO£-02 NA 1.00 UOE-02 NA
2-butanone NA 5.00£-02 NA 1.00£-02 O.DO NA 4.50£-02
1.1,1- tric:hloroethane NA ~.00£-02 NA 3.00£-01 O.~O NA 8.10£-02
c:arbon tetrac:hloride 1.30£-01 7.00£-04 1.30£-01 NA 0.80 1.63£-01 5.60£-04
1,1,2,2 - tetrachloroethane 2.00£-01 NA 2.00£-01 '" NA O.~ 2.22£-01 NA
1.2 -dic:hloropropane 6.80£-02 NA NA NA O.~ 6.67£-02 NA
tric:hloroethene 1.10£-02 NA 1.30£-02 NA 0.~5 1.16£-02 NA
1,1,2-tric:hlor08thane 5.70£-02 4.00£-03 UO£-02 NA O.DO 6.33£-02 3.60£-03
benune 2.90E-02 NA 2.90£-02 NA 1.00 UO£-02 NA
4-methyl-2-pentanone NA 5.00£-02 NA NA 0.90 NA 4.50E-02
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c-
~
2
CHEMICAL SPECIFIC RISK FACTORS
~~t
Chronic Chronic Chronic
Oral Inhala~ion Inhala&ion Oral Dermal Denn&l
CPF-oral RID CPF R!D Abaorp&ioD CPFa R!D
CHEMICAL (mc/ltc/d)"1 (me/ltc/d) (mc/kC/d)-l (me/kc/d) Fac&or (mc/ltc/d)"l (me/ltc/d)
tetrachloroethene 5.10E-02 l.ooE-02 3.3OE-03 NA O.~ 6.6TE-02 ~.ooE-03
toluene NA 3.ooE-01 NA l.ooE+oo 1.00 NA 3.ooE-01
chlorobenlene NA 3.ooE-02 NA 6.ooE-03 0.31 NA ~.30E-03
ethylbencene NA l.ooE-OI NA NA 0.82 NA 8.20E-02
xylene. NA 2.ooE+00 NA 4.ooE-01 1.00 NA 2.ooE+00
phenol NA 6.ooE-01 NA NA O.~O NA 6.40E-Ol
1,4 -dichlorobenlene 2040E-02 NA NA 1.ooE-01 1.00 2040E-02 NA
1.2 - dichlorobeneene NA 4.ooE-01 NA 4.ooE-02 O.~O NA 3.60E-Ol
cresol NA 5.00E-02 NA NA O.~O NA 4.60E-02
nitrobeneene NA 5.00E-04 NA 6.ooE-04 0.90 NA 4.50E-04
isophorone 4.l0E-03 1.50E-Ol NA NA 0.90 4.56E-03 1.35E-Ol
benloic acid NA 4.ooE+00 NA NA 0.40 NA 1;60E+oo
2,4-dichlorophenol NA 3.ooE-03 NA NA MO NA 2.70E-03
1,2,4 -trichlorobenlene NA 2.ooE-02 NA 3.ooE-03 0.90 NA 1.80E-02
nap&halene NA 4.ooE-01 NA NA 1.00 NA 4.ooE-01
4 -chloroaniline UOE-02 4.ooE-03 NA NA 0.90 UIIE-02 3.60E-03
diethylphthalate NA 8.00E-Ol NA NA 0.15 NA 1.20E-Ol
N -nitro.odiphenylamine . 4.~E-03 NA NA NA 0.110 5.44E-03 NA
pentachlorophenol NA 3.00E-02 NA NA 0.110 NA 2.70E-02
di-N- butyl phthalate NA l.ooE-OI NA NA 0.85 NA 8.50E-02
benlidine 2.30E+02 3.ooE-03 2.30E+02 NA 0.90 2.56E+02 2.70E-03
butylbenlylphthalate NA 2.ooE-01 NA NA 0.15 NA 3.00E-02
benlo(a)anthracene 1.15£-01 NA NA NA 0.50 2030£-01 NA
bi.( 2 -ethylhexl )phthala~. UO£-02 2.ooE-02 NA NA 0.15 11.33£-02 3.00E-03
chry.en. 1.15E-Ol NA NA NA 0.50 2.3OE-Ol NA
benlo(b)nuoran&hen. 3.45E+00 NA NA NA o.1S 1.90£+00 NA
benlo(a)pyrene 1.15£+01 NA NA NA 0.50 2.30£+01 NA
indeno( 1 ,2 ,3-cd)pyrene 1.15E-Ol NA NA NA 0.60 2.30£-01 NA'
dibenl(a,h)anthracene 1.15E+Ol NA NA NA 0.50 2.30£+01 NA
~ldrin 1.10E'+01 3.00E-05 1.10E+Ol NA 0.50 3.40E+Ol 1.50E-05
dieldrin 1.60E+Ol 5.00E-06 1.60E+Ol NA 0.50 3.20E+Ol 2.50E-05
endrin NA 3.ooE-04 NA NA 0.50 NA 1.50E-04
..
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3
CHEMICAL SPECIflC RISK FACTORS
..
Chronic Chronic Chronic
Oral Inhalation Inhalation Oral Dennal Dennal
CPF-oral R1D CPF R1D Ab80rption CPF. R1D
CHEMICAL (mc/kc/d)"l (me/kc/d) (me/ka/d)"l (me/ka/d) Factor (ma/ka/d).l (ma/kc/d)
4,4'-DDT 3.40E-Ol 5.00£-04 3.40£-01 NA 0.50 6.80E-Ol 2.50£-04
chlordane 1.30£+00 6.00£-06 1.30£+00 NA 0.50 2.60£+00 2.50£-05
aroclor-1242 7.10£+00 NA NA NA 0.50 1.54E+Ol NA
araclor~ 1248 1.10£+00 NA NA NA 0.50 1.54£+01 NA
aroclor-12S4 1.10£+00 NA NA NA 0.50 1.54E+01 NA
araclor-1260 7.10£+00 NA NA NA 0.50 1.54£+01 NA
PCBs 7.70£+00 NA NA NA 0.G5 8.11£+00 NA
NA Not Available
CPF Carcinoaenic Potency Factor
RID Reference Do.e
a Dermal risk factors are calculated as follows:
:.<
Oral CPF
oral absorption fa,ctor
Oral RfD . Oral Absorption Factor.
=
Dermal CPF
Dermal RfD
. ,
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v
APPENDIX V
PROCEDURE POR CONDUCTING RISK
CALCULATIONS POR AIR BHISSIONS
The carcinogenic risk calculations shall be the summation of a
.
lifetime averaged exposure rate for each constituent times that
This is
constituent's inhalation carcinogenic potency factor.
summarized in the following equation:
CR
CR
1:
IIi -
:.I
ISFi
= 1: (II) i (ISF) i
= CUmulative lifetime carcinogenic risk.
= Summation of the carcinogenic risk of each.
constituent in the air emission.
Lifetime averaged exposure rate to compound i.
More information from the design will be needed
to determine IIi for each process or combinat;on
of processes. However, the values for INR, ET,
EF, ED, BW, and AT from Appenidix IV shall be
used for exposures to residents. In addition
IR for workers shall be 1.3 cubic meters per
hour.
=
Inhalation carcinogenic potency factor (or
slope factor) for compound i. The ISFs are
listed in Table 2 of Appenidix IV.
The chronic non-carcinogenic risk index is calculated as follows:
NI
NI
1:
II,
RfDi
= 1: (II) ;/RfDi
=
cumu~ative 'chronic non-carcinogenic index
= Summation of chronic non-carcinogenic risk
for all constituents affecting the same
target organ
= Chronic exposure rate of constituent i. More
process specific information is needed to
calculate this number.
= Inhalation reference dose of constituent i.
The RfDi are listed in Table 2 of Appenidix
IV.
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