PB94-964313
EPA/ROD/R07-94/074
December 1994
EPA Superfund
Record of Decision:
Valley Park TCE Site,
Wainwright Operable Unit, MO
9/29/1994
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RECORD OF DECISION
VALLEY PARK TCE SITE
WAINWRIGHT OPERABLE UNIT
VALLEY PARK, MISSOURI
PREPARED BY:
U.S. Environmental Protection Agency
Region VII
Kansas City, Kansas
SEPTEMBER, 1994
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DECLARATION FOR THE RECORD OF DECISION
SITE NAME AND LOCATION
Valley Park TCE Site
Wainwright operable Unit
Valley Park, Missouri
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action
for the Wainwright Operable unit (WOU) of the Valley Park TCE
site (Site) in Valley Park, Missouri chosen in accordance with
the Comprehensive Environmental Response, Compensation, and
Liability Act of 1980 (CERCLA), as amended by the Superfund
Amendments and Reauthorization Act of 1986 (SARA) and the
National contingency Plan, 40 C.F.R. Part 300. This decision is
based on the Administrative Record file for the WOU of the Site.
The State of Missouri concurs on the selected remedy. A
letter from the State of Missouri stating its concurrence is
included in this Record of Decision (ROD) package.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances
the WOU of the Valley Park TCE site, if not addressed by
implementing the response action selected in this ROD, may
present an imminent and substantial endangerment to public
health, welfare, or the environment.
from
DESCRIPTION OF THE REMEDY
The selected remedy is intended to be a final response
action for the WOU but only an interim action for the Site, and
addresses all contamination associated with the principal threats
posed by the WOU. Specifically, -the selected remedy addresses
the volatile organic compound (VOC), metals and polynuclear
aromatic hydrocarbon (PAH) contamination identified in the soil
and the ground water on the WOU only. In the near future, a
final operable unit for the larger Site will address the threat
posed by the ground water contamination located outside the WOU.
The major components of the selected remedy include:
Soil vapor extraction (SVE) will be conducted.
throughout the identified areas of VOC contaminated
soil on the WOU. SVE shall be conducted until VOCs are
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reduced to conce~trations below the performance
standards based on the threat to ground water;
Limited excavation of
VOC and/or PAR levels
performance standards
following manner:
surface soils contaminated with
exceeding the direct contact soil
would be addressed in the
1. VOC-contaminated surface soils located on
the Wainwright property would be covered to
prevent contact without excavation occurring.
At least a four inch layer of gravel was
assumed for cost estimating purposes. An
uncontaminated soil cover could be used
instead of gravel if mixing of the
uncontaminated soil with contaminated soils
would not complicate the remedial action.
The contaminated surface soils must achieve
the direct contact performance standards
within five years from startup of the SVE
system. If performance standards are not
achieved within five years, a one foot depth
of the original contaminated surface soils
located on the Wainwright property would be
excavated and taken to a treatment facility
off the WOU. The excavation would be
backfilled to the original grade and
revegetated consistent with the existing
property;
2. PAH contaminated surface soils located on
the Wainwright property would be excavated.
and taken to a treatment facility off the
WOU. All PAR contaminated surface soils
would be excavated until direct exposure
performance standards could be met. For cost
estimating purposes, it was assumed a one
foot deep excavation would be required. The
excavation would be backfilled with clean
soils to the original grade and revegetated
consistent with the existing property.; and,
3. VOC and PAH contaminated surface soils
located on the WOU but off the Wainwright
property would be excavated to one foot below
surface and taken to a treatment facility off
the WOU. The excavation would be backfilled
with clean soils to the original grade and
revegetated consistent with the existing
property.
For cost estimating purposes, it was estimated that 95
cubic yards of soil would require excavation and
treatment. The technology identified for soil
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treatment at the hazardous waste treatment facility off
the WOU is low temperature thermal desorption. This
technology is assumed for cost estimating purposes.
The final treatment technology selected for the
excavated soil may change depending on the facility
selected and is subject to MDNR and EPA approval;
A ground water extraction and treatment system which
will hydraulically control the impacted ground water
throughout the entire vertical section of the aquifer
underneath the WOU will be implemented. The extraction
system will include at least one extraction well
located on the WOU. Air stripping technology will be
used to treat the extracted, contaminated ground water.
The treated water will be discharged to the
Metropolitan Sewer District POTW serving the City of
Valley Park;
An air sparging system would be installed to inject
compressed air into the ground water below the area
directly north of and beneath the Wainwright building.
If lateral vapor migration to horizontal conduits can
not be controlled using SVE, the air sparging
technology will not be included in the remedial action;
A deed restriction would be placed on the WOU by the
property owners to prohibit the installation and
operation of ground water supply wells on the WOU;
Ground water monitoring would be conducted to assess
the effectiveness of the remediation: and,
Ambient air samples from the interior of buildings on
the WOU will be analyzed for WOU contaminants during
the remedial design. MDOH health-based ambient air
criteria will be used to determine the need for
remedial actions to prevent unacceptable ambient air
inhalation exposure risks.
STATUTORY DETERMINATIONS
The selected remedy for the WOU is protective of human
health and the environment, complies with Federal and State
requirements that are legally applicable or relevant and
appropriate to the interim action for the Site, and is cost-
effective. Although this interim action for the Site is not
intended to fully address the statutory mandate for permanence
and treatment to the maximum extent practicable, this interim
action utilizes treatment and thus is in furtherance of that
statutory mandate. Because this action does not constitute the
final remedy for the Site, the statutory preference for remedies
that employ treatment that reduces toxicity, mobility, or volume
as a principal element, although partially addressed in this
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r
/
remedy, will be addr~ssed by the final response action for the
site.
This remedy will result in hazardous substances remaining on
the Site above health-based levels. As a result, a review will
be conducted to ensure that the interim action for the WOU
continues to provide adequate protection of human health and the
environment within five years after commencement of the interim
action. Because this is an interim action ROD, review of this
Site and of this remedy will be continuing as EPA continues to
develop final remedial alternatives for the Site.
De n's Grams, P.E.
- Reg'onal Administrator
U.S. EPA, Region VII
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STATE Of MISSOL'RI
DEPARTMENT OF NATURAL RESOURCES
----,- j )FFI(T 1>1 'Iii: !)"\F(:T()I~
I>() II", \-" klk'!"..,ql) \.!I\ \1() .''\1'12-11\-"
"I! 1-';1-11.:2
: \' '. -:
SEP 2 1 1994
Mr. Dennis Grams
Regional Adminisuaror
U.S. Environmemal Prorecrion Agency
Region VII
726 Minnesota Avenue
Kansas City, KS 6610 I
Dear Mr. Grams:
The MDNR (Missouri Department of Narural Resources) concurs with the ROD (Record Of
Decision) for the Valley Park TCE Site - Wainwright Operable Unit as presemed by rhe U.S.
Environmental Protection Agency. The ROD was based on the Proposed plan which MDNR
developed. MDNR supporrs the remedial actions described in the ROD for the Wainwright
Operable Unit of the Valley Park TCE Sire entered on the National Priorities List in Federal
Register Volume 51, Number Ill. Page 21091. Group 10.
I f you have any questions, or if I can be of further assistance in this matter I can be reached at
(314) 751-4422.
Very rruly yours,
MISSOURl DEPARTMENT OF NATURAL RESOURCES
&J~
David A. Shorr
Director
DAS:ES:dml
~
n
\.-'
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RECORD OF DECISION
DECISION SUMMARY
VALLEY PARK TCE SITE
WAINWRIGHT OPERABLE UNIT
VALLEY PARK, MISSOURI
PREPARED BY:
MISSOURI DEPARTMENT OF NATURAL RESOURCES
DIVISION OF ENVIRONMENTAL QUALITY
JEFFERSON CITY, MISSOURI
ON BEHALF OF:
u.S. Environmental protection Agency
Region VII
Kansas City, Kansas
SEPTEMBER, 1994
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1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
11. 0
TABLE OF CONTENTS
SECTION
PAGE
SITE NAME, LOCATION AND DESCRIPTION
1
SITE HISTORY AND ENFORCEMENT ACTIVITIES
1
HIGHLIGHTS OF COMMUNITY PARTICIPATION
9
SCOPE AND ROLE OF RESPONSE ACTION
10
SUMMARY OF SITE CHARACTERISTICS
11
SUMMARY OF SITE RISKS
12
DESCRIPTION OF ALTERNATIVES
16
SUMMARY OF THE COMPARATIVE ANALYSIS OF
ALTERNATIVES
30
THE SELECTED REMEDY
36
STATUTORY DETERMINATIONS
38
DOCUMENTATION OF SIGNIFICANT CHANGES
41
APPENDIX A - GLOSSARY
RESPONSIVENESS SUMMARY
i
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LIST OF FIGURES
,
FIGURE 1. GENERAL SITE LOCATION MAP
FIGURE 2
FIGURE 3
FIGURE 4
PAGE
SPECIFIC SITE LOCATION MAP
PAGE
WELL LOCATION MAP
PAGE
PROPOSED WOU GROUND WATER
MONITORING WELLS
PAGE
ii
2
3
6
18
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TABLE 1
TABLE 2
TABLE 3
TABLE 4
TABLE 5
TABLE 6
TABLE 7
TABLE 8
LIST OF TABLES
CONTAMINATION DATA FOR VALLEY PARK
MUNICIPAL WELLS
ANALYTICAL RESULTS OF VALLEY PARK
SAMPLING
SUMMARY OF NON-CARCINOGENIC RISKS
SUMMARY OF CARCINOGENIC RISKS
SUMMARY OF REMEDIAL ALTERNATIVES
MCLs FOR CONTAMINANTS OF CONCERN
SOIL PERFORMANCE STANDARDS
COSTS OF REMEDIAL ALTERNATIVES
iii
PAGE 5
PAGE 8
PAGE 15
PAGE 15
PAGE 17
PAGE 26
PAGE 29
PAGE 35
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SECTION 1.0
SITE NAME,- LOCATION, AND DESCRIPTION
The Wainwright operable Unit (WOU) includes an area within and
adjacent to property-owned by Wainwright Industries, Inc.
(Wainwright) located in valley Park, Missouri described below.
The weu is part of a larger site, known as the Valley Park TCE
site.
The weu is located in the downtown area of the city of Valley
Park, Missouri as generally shown in Figure 1. The city of
Valley Park is located in the southwest portion of st. Louis
County. Referring to the shaded portion of Figure 2, the weu
consists of the following city lots within city block #20:
1) nine city lots (7, 8, 9, 10, 11, 20, 22, and 23) located at
220 and 224 Benton Avenue and 219 and 233 Vest Avenue owned by
Wainwright Industries, Inc. and used for industrial purposes,
2) two city lots (15 and 16) located at 318 3rd Street owned by
Jack and Mary Cotton, 3) the three city lots (12, 13 and 14)
located at 314 3rd street owned by Bennett and Anne Netzer, and
4) the three city lots (4, 5 and 6) located at 218 Benton Avenue
owned by Richard and patricia Menley. Lots 12 through 14, and 15
and 16 are used for residential purposes. St. Louis Boat & Canoe
Company operates a business on the Menley property at 218 Benton
Avenue. The weu is bordered on the north by Vest Avenue, on the
east by 3rd Street, on the south by Benton Avenue and on the west
by commercial properties. The sources of contamination
originated and continue to exist on the wainwright properties.,
The above listed commercial and residential properties located
adjacent to the Wainwright property are included in the
definition of the WOU to facilitate the potential need to conduct
remedial activities on those properties as part of the remedial
action for the weu.
The weu is located in the floodplain of the Meramec River, which
flows from west to east approximately '/4 mile to the south. The
northeast flank of the ozark Plateau is located approximately '/4
mile to the northwest. Valley Park is located on the western
edge of a large suburban area surrounding the City of st. Louis
which is located ten miles to the east.
SECTION 2.0
SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1
Site History
Wainwright has owned the property at 224 Benton Avenue since
1947. Wainwright operated a metal stamping and tool and die shop
at the facility until 1979. Part of the manufacturing process
included a solvent degreasing system that used the solvents
trichloroethylene (TCE) from 1963- to 1970 and perchloroethylene
(PCE) from 1970 to 1979.
1
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---------- ---_.- -----'- --'~_4. -_._--~_..
. 4 -M._- .--
_04. - - - -
.-- . .--..------- ...-.
- .- .-- -. '0_0- -. _M..
IIJ
.
I
N
I
SOIl,ee
l\i,l
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FIGURE 2.
SPECIFIC \VOU LOCA'1'10IJ MAP
*
LOT NUMBERS SHOWN OI"F THE WOU ARE
REAL ESTATE LOCATOR NUMBERS AND NOT
OFFICIAL CITY LOT NUMBERS.
** '1'WO DIGI'l' 1.0'1' NUMBERS SIIOWN ON '1'IIE
WOU ARE OFFICIAL CITY LOT NUMBERS.
w
*** '1'IIE AHEA MARKELJ
IS 'rHE WOU
t
I \J
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From 1980 to 1987 the Wainwright property was leased to Imperial
Ornamental Metals, who produced ornamental structura~ metal
fabrications. The L.E. Mueller Company is the current tenant of
the facility. The ~.E. Mueller Company operates a emergency fire
vehicle repair and remodeling shop at the Wainwright property.
2.2
site Investiqations
Beginning in July 1982, MDNR detected volatile organic compounds
(VOCs) in samples collected from three Valley Park municipal .'
wells. The VOCs included TCE, PCE and l,l,l-trichloroethane
(TCA). Sample results are included in Table 1. Concentrations
of contaminants exceeded the State and Federal drinking water
Maximum contaminant Levels (MCLs). Figure 3 presents the
locations of the three Valley Park municipal wells, along with
two downgradient ~unicipal wells owned by the City of Kirkwood.
The City of Valley Park began treating its public drinking water
supply with an aerator after contamination was discovered in
1982. Treatment was later upgraded to an air stripper tower
which succeeded in reducing contamination below acceptable
limits. The City of Valley Park was connected to the st. Louis
County water supply in 1988. The st. Louis County Water supply
to the Valley Park area is derived from intakes on the Missouri
River, .
In June 1983, EPA conducted a partial NPDES compliance monitoring
inspection at the Spencer-Kellogg facility (owned by Reichhold
Chemical, Inc.) in downtown Valley Park. Analytical results of
the non-contact cooling water revealed the presence of
chlorinated VOCs. The investigation concluded that the VOC
contamination detected in the cooling water was from the well at
the facility which withdrew water from the same aquifer as the
municipal wells.
In April 1986, Wainwright was identified in a study conducted by
contractors for EPA as the most likely potentially responsible
party (PRP).
In August 1986, MDNR was notified that Valley Park city workers
had encountered strong solvent odors during an excavation of a
water line on the Wainwright property. With assistance from the
City of Valley Park, MDNR collected and analyzed two shallow soil
samples collected near the sewer line manhole from the north-
south alley behind the wainwright buildings. The analytical
results revealed the presence of chlorinated hydrocarbons,
similar to those found impacting the City of Valley Park
municipal water supply wells.
4
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'I' ,E 1
CONTAI\:IINATION DATA FOR V ALLEY PARK MUNICIPAL Wl~LLS (7-12-82 - 7-23-H7)
Source: PRC Engineering, 1986 .
ESE Limited HI, 1988
U1
-- -- ---------. -- ---- --.-
Well #1 Well 112 Well 1/3
Dale Trichloro- Telrachloro- 1.1,1- Trichloro-. Tclrat:hloro- I , I - 1- Trichloro- TClrachloro- 1,1,1
elhylene elhylene Trichloro- elhylene elh}'lcne '1'1 ichloro- elhrlel1:: clhylcne TI ichl.j(,)
(lIglI) (lIglI) elhane (lIg/l) (ug/l) (lIg/l) clhane (lIg/l) (lIg/l) (lIg/l) clhane (lIg/l)
-- - -----.-
July 12, 1982 -- -- -- -- -- -- 95 1.5 1J
April 6, 1983+ u -- " 67 3.3 1H S() JO . ~ I
-- -- -- 63 3.5 37 69 3.5 38
April 14, 1983+ 75 10.0 49 n -- -- -- -- ..
76 12.0 48 -- -. -- -- -- .-
Seplember 19, 1983+ 310 222 58 420 21.0 280 20 3.6 . 12
280 130 60 370 18.0 26 370 16.0 i t)O
Ot:lobcr 12, 1983 290 120 130 190 IG.O 120 200 1H I !:II
November 9, 1983 310 94 IHO 180 16.0 no -- --
December 14, 1983 . 220 5~ 1.10 110 6.7 11.0 -- --
Fcbmary 3, 1984 330 200 140 -- -- -- 200 12.0 I 20
June 26, 1984 -- -- -- -- n -- 180 II () 120
Ot:lober 24, 1984 63 ' . 18 62 -- n n 93 9.2 120
January 29, 1985 62 78 25 -- n -- 140 9.1 75
June 18, 1985+ 25 42 7.7 -. -- -- 98 9.6 57
30 44 10.0 -- -- -- 90 9.9 56
July 10. 1985+ -- -- - - -- -- - - 79 8.-1 ,17
-- -- -- -- -- -- 83 8.1 44
Scplember 1,6. 1985 41 63 16 -- n -- 113 11.2 117
OCloher 28, 1985 46 33 19 -- n -- 56 S 2 l.~
Maid. 17, I!JH(, 2h 21 91 -- -- .- 71) 6.~) .111
,
July 23, 1987 21.1 140 ,US -- -- - - 337 US 236
---.
+Morning and afternoon samples. respeclively
-- denoles non-delect concentralions
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~ ~-------------- - .
.----- . .-.--.----.-----------.------- ..-- ~ -._-- - .
I .....
CROSS SECTION
1.1::Gftli!
(9-VP3) KIHKWOOD (I() PUMI'ING WELL
VALLEY PARK (VP) PUMPING W8LL @
---~-----
-. ~~ -.---
8
VALLEY J J AHI< MUNICIPAL
WELLS & GROUNDWATEH
MONITORING WELLS
VALLEY PAHK-KIRKWOOD
VICINITY
VALLEY PAHK. MISSOURI
, t'IGlJHI:: ~J
------.
CROSS SECTION (1 - 17)
CROSS SECTION (9-8)
GROUNDWATER 1.IOtIlTOHING WELL
SCALI~
I" .: 1620'
WAIN 07
.- --- - --- ~ - ----.
-..----.:""'-
.- -.-.- - -- -- - . . ~- - --. .
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Between May and September 1987, MDNR contracted with Hunter
Engineering/ESE to perform a Limited Remedial Investigation
(LRI). The study involved installation, sampling and analysis of
26 monitoring wells and sampling and analysis of the Meramec
River. Analytical results from this investigation are presented
in Table 2.
The LRI led to the following conclusions:
- PCE, TCE, and TCA concentrations were found in the Valley Park
ground water at various monitoring wells, municipal wells, and an
industrial well.
- The source of PCE and TCE contamination appeared to be in the
vicinity of the wainwright property. The highest concentrations
of PCE and TCE were found in Monitoring Wells 17B, 17C, 10C, and
the Reichhold well (refer to Figure 3 for well locations).
- The source of the TCA contamination is not the Wainwright
property and appears to be located between Marshall Road and
Valley Park municipal well #3. The highest concentrations of TCA
were found in Valley Park well #3.
In April and October 1988, Wainwright contracted with an
environmental firm to perform shallow composite soil sampling
(trom one to eight feet deep) behind the Wainwright building to
the north. The analytical results indicated concentrations of
PCE up to 2,200 ppm (parts per'million) and TCE up to 540 ppm'in
the upper one foot of soil behind the building. Contaminant
concentrations decreased with depth, but were detected down to
eight feet.
2.3
Enforcement Historv
In 1985, the EPA evaluated the Valley Park TCE site (Site) using
CERCLA's Hazard Ranking System. The Site was evaluated based
solely on ground water contamination. In 1986 the Site was
placed on the National Priorities List (NPL) in Federal Reaister
Volume 51. Number 111. Paqe 21091! Group 10.
On May 15, 1989, Wainwright was officially notified by EPA of
their liability rel~ted to the Valley Park TCE Site under CERCLA
Section 107.
In July and September 1989, Wainwright contractors collected
samples from deeper (10 to 35 feet) soil borings under the
building and to the south along Benton Street. Soil was field
screened using a portable infrared spectrophotometer. only soil
indicating positive results during field screening was collected
for laboratory analyses. Analytical results revealed
7
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TABLE 2
ANALYTIC:\L IH~SULTS OF VALLEY PAHK S:\MI'LlN(;
(.HIL Y 191)7 - ESE)
P,\({,\METER: CIII-OIUD!: mCIII-ORO- 1.2.DICIII.O- Clll.OnOHJR I.I.I-TCA TETRA- TIUCIII.OIm. TETII"<:III.I 1\:11
I\1lj/1. ETIIYLENE ROETIIYLENI~ M UG/L CIILOIHI>E ETIIYLENE ETIIYIHH:
tlG/L lIG/1. I!(j/L lJl.jJL 11(1/1. III ;/1.
UNITS:
FLD. GRP. # SAMPLE ID DATE TIME
\' AI PAZ 31 t-tWIII co 01/24/111 08:015 n4 1.11 <250 I.II! <:: 2 1111 1 .,(, .; ~ 00 ~ ~I ( )
V AI.PAZ 41 MWII2II11 01/28/81 \19;00 IJ8 < 1.15 266 < 100 < 2.110 <: 115 < 21111 .; I 511
V ALPAl 38 MWIUCO 01/28/81 09:40 148 < 1.15 <2.50 < I no < 2.110 < 1.15 <2.1111 < 2 50
v AtPAl 31 MWII3nO 07/28/81 10:45 1'"/.5 .~ 1.15 <2.511 < I (III <21111 < 125 < 2.no < 2 511
VALPA2 39 MW03CO 07/2R/87 10:15 51.6 < 1.15 < 2511 < I IXI <21111 < 125 I ~ I) 5 .111
V AI.PA2 44 Mwn.tCO 07/2~~L-.JL~0 5~~ < 1.15 < 2.~1I < I IXI < 2 no < 125 < 2.00 " 2 50
.--.-.-.---
V AI.PA2 43 MW051111 01/2R/R1 1);45 II'> < 1.15 <2.50 -: 100 <100 .; 115 <: ~ (MI 2! ..
VALPA2 45 MW05CO 01/28/87 n:1S .111.1 < 1.15 <2.511 < IIKI <2110 < 1.15 1 'II ~. .n
v ALPA2 I MW06DO 07/29/81 10:ZO 114 < 1.15 2.74 < 1110 4.46 < 1.25 211.0 61, .\
VAI.PA2 7 MW06CO 01/29/87 09:50 59.6 2.47 4.62 < 11111 881 < 125 505 I,J R
V AI.I'A2 \8 MWlI1nO 07/27/87 15:35 3(, 2 < 1.15 <2.511 < 1110 '~2110 < 1.15 ,,200 . ~ '.0
~~I.PA2 14 MWOICO 01121/87 I~:OO 95 3 4.24 RAr. J:!5 21.11 < 1.~5 4 ~.H .; ~ ~O
-.-.------- - -- ..
V AI.I'A2 15 MW07CO 01/21/87 15:00 09.01 3.02 12!) -: 100 31.0 < I 25 6') 1 ~ Ii
V AI.PA2 25 MWII8110 07/27/R7 08:45 586 < 115 < 2.511 < 11111 < 2.(KJ < 1.25 .; 2.DO . .~. ',{I
V ALPA2 26 M WII8CO 07/27/87 09:30 43.7 < 1.15 5.52 < 1 IMI < 2 (III < 1.25 2M '. 2 SII
VAI.I'A2 42 MWII9CO ()112S187 14:40 3]8 < 1.15 < 2 . 50 < 11111 <21111 <, 2S " 2 (1) '-. ~ ~I)
V AI.I'A2 17 MWIOIIII 01127/87 14: I 5 8) 4 < I 15 4.111 < I tXI < 2 1111 <: 125 ]X :I J.; !
V AI.I'A2 I) M W lOCO 01127/81 13;45 98.3 3.02 5.111 255 5.:17 2.2:1 1112 !.IK
-----"-.-------.- _.._--
V,\ 1.1' A 2 16 MWIICO 07/27/87 II ;50 %(, < 175 3.32 < 100 <200
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contamination under the.building concentrated near the northwest
annex and to the north of the building.
An Administrative Order on Consent between EPA and Wainwright was
signed on August 7, 1990 which provided for a removal action at
the WOU. On August 13, 1990, MDNR and EPA approved Wainwright's
Revised Removal Work Plan. The plan outlined a cleanup action
that included the excavation of soil in areas which had
previously been identified as having TCE or PCE contamination
over 20 ppm.
The removal action was performed between September and November,
1990. Approximately 330 cubic yards of contaminated soil was
excavated and disposed of at an hazardous waste landfill.
Verification sampling in the excavation revealed TCE and PCE
contamination remaining above the established cleanup level of 20
ppm. The removal action was discontinued at that time due to the
greater than anticipated magnitude of contamination. The
excavated area was subsequently backfilled with pea gravel and
asphalted to minimize the infiltration of water into the
contaminated area.
On May 22, 1991 Wainwright and MDNR.signed an Administrative
Order on Consent to conduct the Remedial Investigation and
Feasibility Study (RIjFS) at the WOU, which. would thoroughly
characterize the extent and magnitude of contamination. The
objectives of the RIjFS at the WOU was to (1) characterize the
nature and extent of the soil contamination at the WOU,
(2) determine whether ground water under the WOU is contaminated
and identify the connection between ground water contamination
and contaminated soils, (3) characterize the geology and ground
water flow patterns at the WOU, (4) identify risks from
contamination at the WOU, and (5) develop alternatives for the
cleanup of contaminants at the WOU. The Results of the RI and FS
activities are summarized in Sections 5.0 and 7.0, respectively.
Copies of the RI and FS reports are included in the
Administrative Record.
In 1989, 1991 and 1993, EPA sent Section 104(e) Requests to a
number of industries located in V~lley Park, Missouri. The
responses indicated there were no other PRPs for the WOU.
SECTION 3.0
HIGHLIGHTS OF COMMUNITY PARTICIPATION
The RIfFS and the Proposed Plan for the WOU were released to the
public on August 14, 1994. The Administrative Record file, which
included the RI/FS reports and the Proposed Plan, was made
available for public review at the information repositories
maintained at the Valley Park Public Library and at MDNR
Hazardous Waste Program in Jefferson City, Missouri. The notice
of availability for these documents was published in the West
9
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County Suburban Journa17' on August 14, 1994. The public comment
period on these documents continued for thirty days from August
14 to September 12, 1994.
.A pUblic meeting was held by MDNR and EPA on August 24, 1994 in
the Valley Park City Hall in Valley Park, Missouri. Interested
citizens' were given the .opportunity to hear a summary of MDNR's
Proposed Plan and provide comments or ask questions concerning
the investigations or remedial alternatives. A transcript of the
public meeting is included in the Administrative Record. A..
response to the comments received during the public comment
period is included in the Responsiveness Summary section of this
Record of Decision. At this meeting, MDNR and EPA
representatives answered questions about problems at the WOU and
the remedial process. In summary, the public participation
requirements as defined in CERCLA Sections 113(k) (2) (B) (i-v) and
117 were satisfied.
This decision document presents the selected remedial action for
the Wainwright Operable Unit of the Valley Park TCE Site, in
valley Park, Missouri, chosen in accordance with the provisions
of CERCLA, as amended by SARA, and the National Contingency Plan
(NCP). The selection of a response action for the WOU is based
on the Administrative Record.
. SECTION 4.0
SCOPE AND ROLE OF RESPONSE ACTION
This Record of Decision selects an interim action to address'
contamination at the WOU which acts as a source for ground water
contamination for the Valley Park TCE Site. This Record of
Decision addresses all contaminants identified at the WOU in each
media, including ground water and soils. Contaminated ground
water located off the WOU will be addressed in future actions for
the larger Valley Park TCE Site. The interim action selected in
this Record of Decision will be consistent with any planned
future actions for the Valley Park TCE Site, to the extent
possible.
The Remedial Investigation perfo~med by Wainwright clearly
identified three principle threats at the WOU: the contaminated
ground water originating on the Wainwright property, the
contaminated subsurface soils acting as a source of ground water
contamination, and contaminated surface soils. The remedial'
action objective for the WOU is to eliminate the current and to
prevent future unacceptable exposures due to these three
principal threats.
10
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SECTION 5.0
SUMMARY OF WOU CHARACTERISTICS
Work plans for the WOU RIjFS were approved on February 4, 1992 by
MDNR. Field activities related to the RIjFS were conducted from
April through September 1992.
Listed below is a summary of the findings of the RI:
- The soils in the Valley Park area are alluvial in nature
and act as the primary shallow aquifer. There are three.
basic soil horizons underlying the WOU. The upper soil zone
is silty clay which ranges from 5 to 40 feet thick. The
middle zone is composed of lenses of sand and gravel, which
range from 8 to 46 feet thick. The basal zone is limestone
bedrock.
- The water table was most recently encountered at depths
between 19.8 and 21.48 below ground level. The ground water
does not appear to be perched. Ground water flow is toward
the Meramec River to the south, except possibly during
flooding, which can change ground water elevations and
reverse gradients. Ground water flow rates in the alluvium
are estimated at 763 feet per year.
- PCE and TCE are the primary contaminants of concern at the
WOU. Various semi-volatile compounds and metals were also
identified in WOU soils as being elevated. Elevated metals
concentrations were also detected in ground water upgradient
of the WOU. The metals detected in the ground water may be
due to suspended solids present in the upgradient wells.
- The greatest concentrations of PCE and TCE in the ground
water (1500 parts per billion (ppb) and 420 ppb,
respectively) occurred in wells closest to and immediately
downgradient of the WOU. No wells were drilled directly
under the WOU. Upgradient wells contained either no
contamination or very low concentrations.
- Soil contamination concentrations show a general reduction
with depth, but extend to depths greater than 35 feet. Two
neighboring residential yards to the east and possibly
industrial areas to the west have been contaminated by
activities on the Wainwright. Areas off the WOU to the
north and south did not have contaminated soil. The highest
contamination in the soil was found on the Wainwright
property at 6800 ppm for PCE and 420 ppm for TCE. The only
known source of contamination at the wou is Wainwright
Industries, Inc. as a result of its operation at the WOU
from 1947 to 1979.
-A risk assessment conducted by the Missouri Department of
Health was included in the RIjFS. A more detailed summary
11
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of WOU risks and the potential routes of exposure will be
presented in Section 6.0.
-The remedial alternatives contained in the FS will be
summarized in Section 7.0.
After completion of the RI/FS field activities, the occurrence of
the two following events affected the WOU characterization:
1) Valley Park was flooded during september of 1993.
MDNR conducted post flood soil sampling along the
fence-line separating the Wainwright property from
neighboring residential properties. PCE was detected
as high as 11 ppm in the surface soils of the Cotton
residence located at 318 3rd Street.
2) The Cotton residents also began complaining of
strong odors in the house after the flood. Air
sampling conducted in January 1994 by EPA contractors
revealed the presence of PCE (2400 micrograms per cubic
meter (ug/m3» along with other VOCs in the Cotton
home. Traps were installed on plumbing fixtures in the
house and air sampling was conducted again in March
1994. organic contaminants associated with the WOU
were found at much lower levels during the March
sampling with PCE detected at 140 ug/m3.
SECTION 6.0
SUMMARY OF RISKS
As part of the RI/FS process, the Missouri Department of Health
(MDOH), on behalf of MDNR, developed a Baseline Risk Assessment
(BRA) to estimate the human health and environmental risks
associated with possible exposure to contaminants identified at
the WOU. The BRA was conducted in accordance with all relevant
and current EPA risk assessment guidance. First, contaminants of
concern were identified. Then, the potential toxicities of these
contaminants were reviewed, potential exposures were described
and quantified, and risk characterization was performed. This
analysis provided valuable information used to determine the need
for remedial action(s). -
The contaminants of concern (COCs) include all VOCs and semi-
volatile organic compounds (specifically, polynuclear aromatic
hydrocarbons or PAHs) detected in the ground water and the soil.
Notably, PCE and TCE of the.VOC group and Benzo(a)pyrene of the
PAHs were identified as several of the COCs. The metals detected
in the ground water and the soil were evaluated on an individual
basis and retained if present above background concentrations.
Notably, barium, chromium, lead, -manganese and zinc were
identified as several of the metal COCs. Several of the COCs are
viewed by the EPA to be "possible" or "probable" human
12
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carcinogens and several pi the cecs are known to have adverse
non-carcinogenic health effects. Consequently, both non-
carcinogenic health hazards and carcinogenic risks due to
exposure to these compounds were evaluated.
The potential for non-carcinogenic health risk is evaluated by
comparing estimated contaminant intake to a reference dose. The
ratio of contaminant intake to the reference dose is referred to
as the hazard quotient or hazard index. A hazard quotient
greater than one indicates that a hazard may be likely to exist.
Since the estimated contaminant intakes calculated in the BRA
represent conservatively high estimates, the calculated hazard
quotients represent conservatively high risks. '
The potential for carcinogenic risk is estimated by mUltiplying
estimated contaminant intake by an established slope factor for
each contaminant. The resulting figure represents the chance
that a receptor would develop cancer in excess of a background
incidence. For example, an excess risk of one in ten thousand
(represented as 1 X 10.4) indicates that one additional person
may contract cancer out of 10,000 people identically exposed to a
contaminant. A cancer risk greater than one in ten thousand (1 X
10'4) is considered unacceptable and requires remedial action. A
cancer risk less than one in one million (1 X 10-6) is considered
acceptable. The cancer risk range between 1 X 10'6 and 1 X 10-4
is considered acceptable unless specific conditions warrant
otherwise. The calculated carcinogenic risks are viewed as
conservatively high due to the EPA'scarcinogenic risk assessment
methodology.
The exposure assessment was accomplished through the
identification of exposure pathways, development of Reasonable
Maximum Exposure (RME) scenarios, and the calculation of
contaminant intake values. Several potential exposure pathways
were investigated: ingestion of and dermal contac,t with
contaminated soil and ground water, and inhalation of air
impacted with contaminants volatizing from the ground water and
soil. A total of six RMEs were developed for the weu:
RME 1 - An adult on-site worker exposed to the wau 250
days per year for 25 years;
RME 2 - An adolescent visiting the wau twice a week, 39
weeks per year for six years;
RME 3 - An adult off-site resident exposed to the wau
365 days per year for 30 years;
RME 4 - A child off-site resident exposed to the wau
365 days per year for seven years;
13
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RME 5 - An adult l~v.ing on the WOU 365 days per year
for 30 years: ana,
RME 6 - A child. living on the WOU 365 days per year for
seven years.
Tables 3 and 4 summarize the non-carcinogenic health hazards and
carcinogenic risks developed for the. WOU, respectively. The non-
carcinogenic total hazard indices exceed 1.0 for RMEs 3, 4, 5 and
~. Individual pathway hazard indices exceeded 1.0 for ingestion
and dermal contact with ground water, and inhalation of air
emissions from ground water while showering. The carcinogenic
risks exceeded 1 X 10-4 for RMEs 1, 3, 4, 5 and 6. Individual
pathway cancer risks exceeded 1 X 10-4 for ingestion of ground
water, ingestion and dermal contact of soil, and inhalation of
air emissions from ground water while showering.
The calculated potential risks are based, in part, on ingestion,
inhalation and dermal contact of contaminants in ground water.
However, exposures to contaminated ground water at the WOU are
not currently occurring.
A formal environmental risk characterization was not performed as
part of the BRA. However, exposures to the environment were not.
identified by MDNR and EPA based on the location of the WQU in
downtown Valley Park and the location of the contamination in
ground water and subsurface soils. Under current conditions, no
adverse impacts were identified for the local flora and fauna
ecosystems.
Actual or threatened release of hazardous substances from this
WOU, if not addressed by the remedial action presented in this
ROD, may present a current or potential unacceptable threat to
public health, welfare, or the environment. Residents and/or
employees of properties on the WOU are potentially exposed to the
health risks posed by the actual or threatened release of
hazardous substances in the soil, air and ground water through
dermal, ingestion and inhalation exposures. State and Federal
Applicable or Relevant and Appropriate Requirements (ARARs) will
be used to define cleanup goals for ground water, as appropriate.
Cleanup goals for contaminated sciils will be developed based on
the threats to contaminating ground water and from direct
contact.
14
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TABLE 3.
SUMF~Y OF NONCARCINOGENIC RISKS
. Pathwav Hazard Indices
GrouDdwater Soil Air
InhalatioD Inhalation Total
Dermal Dermal (while (soil Hazard
RME In2estioD CODtact In2estioD CODta~ showerin~) Off2~) ..Iadu
RME 1 NC NC 0.15 0.49 NC 0.0014 0.64
RME 2 NC NC 0.029 0.09 NC 0.00071 0.12
RME 3 NC NC 0.42 0.73 NC 0.002 1.2
RME4 NC NC 0.76 0.79 NC 0.0095 1.6
RME 5 51 4.0 0.42 0.73 1.1 0.002 57
RME 6 12 0.64 0.76 0.79 0.59 0.0095 15
NC = Not Calculated
TABLE 4.
SUMMARY OF CARCINOGENIC RISKS
i Pathway Cancer Risks
'
I I Groundwater I Soil I Air I I
I
I
! I Inhajation I ! Totaj
I Inhajation
: Ingestion I Dermal Dermal ( while I (soil Cancer
i Contact In~estion Contact showering) offgassing) Risk
, R.'\1E
i IUv1E 1 I NC I ~C I 2.5 X 10.5 6.2 X 10.5 NC I 3 . 1 X 10'5 I 1.2 x 1 0"
I
..
! R.'v1E 1 I NC I ~C I 6.1 x 10.0 6.9 x 10.0 I ~C I 1.9 X 10,7 I 1.3 X 10'5
I
: R..'-'IE 3 NC ! ~C I 8.7 X 10'5 1. 1 x 1 0-4 I ~C I 2.7 x 10.0 I 2.0 X 10"
I I I I I 2.6 X 10"
: R..\IE -+ I NC ~C 1. 9 x 1 0-4 7.0 X 1O,5! ~C 3.0 x 10.0
I
I R..'v1E 5 I 5.3 X 10-4 I I I I 1.6 X 10,3
5. i X 10-5 8.7 x 10') 1.1 x 10-- I 7.7 x 1 0-4 1.7 x 10.0
~'v1E 6 I 2.9 X 10-4 I 2.5 x 10') I 1. 9 x 1 0-4 7.0 X 10,5 I 3.7 x 10,5 I 3.0 x 10.0 I 6.2 X 10"
~C = ~ot Calculated
15
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SECTION 7.0
DESCRIPTION OF ALTERNATIVES
Description of Alternatives
Ten alternatives analyzed in detail are presented below and
summarized in Table 5. These alternatives were presented in the
Proposed Plan. Alternatives one through nine were developed by
Wainwright Industries in the Feasibility study Report. The MDNR
and EPA developed Alternative 10 which is simply a modification
of.Alternative 3 and was discussed in the Proposed Plan. All..
costs are estimated. Time-frames to achieve Applicable or
Relevant and Appropriate Requirements (ARARs) and Performance
Standards (PSs), defined later in this section in the ARARs and
PSs subsections (Pages 25 to 29) for the contaminated ground
water and soils, are only estimated at this time due to the fact
that the scope of the RIfFS effort did not include full vertical
and horizontal characterization of the contamination and the
alluvial aquifer. Complete characterization will be completed
and a time-frame to achieve ARARs and PSs for the soil and ground
water remediation activities will be estimated during the design
phase of the remedial action. For this reason, concentration
reductions and risk reduction to be achieved can not be
estimated. For general information, time-frames to achieve ARARs
and PSs using similar cleanup technologies at similar sites will
be given based upon MDNR and EPA experience.
Common Elements for Alternatives 3 through 10 (common Elements)
A deed restriction would be placed on the WOU properties by the
respective owners prohibiting the installation and operation of
ground water supply wells as long as the ground water and soils
are contaminated above ARARS and PSs.
A ground water monitoring program would be implemented using
existing and new monitoring wells. Data from the ground water
monitoring program would be used to evaluate the effectiveness of
the remedial action taken under each alternative and to monitor
changes in ground water quality. For cost estimating purposes,
the program was assumed to include existing upgadient wells (MW-
AAB and MW-AAC), downgradient wells (MW-5 and MW-l7), and a new
set of two wells installed directiy north of the current
Wainwright building (see Figure 4). One of the two new wells
will be finished and screened at the top of the bedrock. The
second new well would be screened in the water table above the
bedrock well. Quarterly sampling for the first year and semi-
annual sampling thereafter, and Volatile Organic Compound
chemical analyses were also assumed to take place.
16
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TABLE 5.
SUMMARY OF REMEDIAL ALTERNATIVES
Sln"lllesp.ns. Action
- .
-
h --
No Action
Inslitulionll Aclions
RI11IDYI' AClion
Isolltion/Conlainmenl AClion
Conecl;on Aclion
Soil T"llmenl Act;on
GroundWlllr T ,.llmenl Aclions
T relIed Groundwller DispoSilion AClions
......
~
.---.'.-
-0
'lcllnololY 'yp.",oce" Options
- -- --.- ._-
No AClion
-
--- un' _. -----
Groundwll.r Olld Resuic..on
Groundwlter Monitoring
Soil hClntion
CommerciI! hndlin Oisposil
Groundwller hlflclion
Soil Vapor hlraclion
Air Spilling
Air Stripping
POTW
-
Aquilet ftt-injeclion
An 1
-
anz
.I
An J
--
"----_..
./
.I
-.
AU'
._- -
- - ......-
./
./
.I
.I
.I
.I
--
.I
.I
./
.-
Ans
---
---
.I
.I
.I
.I
.I
.I
.I
an.
-.----
./
./
.I
./
- -
.~~!-_!o -"~~!-. r~~!!--~:;~~--'
-
./
.I
.I
.I
.I
./
...-
.I
.I
-
-
---
-
.I
----
-
-
-
.I
--
.I
--_._.
-..-
---
.I
"-.-
./
-,--
./
--
.I
-
--
.I
.I
..1
---... --
.I
.I
--...
.I
--
./
--
.I
.I
----
./
.I
_n
".I
./
.I
--
.I
--
.I
-
-------
FIGURE 1.
"-
\
Q
...J
W
.......
k.
)
......
00,)
)
PROPOSED WOU GROUND WATER
MONITORING WELLS
.----..- --- .- .._------~_. ... . ,..-
- --...--------. -
. I
I
I
I
I
ST. I []lJ!S I
-.- -. -------~---l-~:.- "l BOAT & CANOE . :
a :::~:, i ~' - MW",~- L - -- --- - -- -- -.- - -- ( ~ENCE ~:
I- - : -
(/)- - - ~- - - - - - _I
I
I
I
1
- - - - - ;~NC; -~
I
I
It. H\I-118
it H\I 11C
>- I
~I
~I
-------
Alternative 1
Present Worth Cost: $ 0
This is the no action alternative required for evaluation by the
National Contingency Plan. No ac~ions would be taken to reduce
the potential for exposure of humans to wau contaminants. The
restoration of soil and ground water would be accomplished
through natural attenuation processes. Through natural
attenuation, ground water contaminants would be transported off
the wau through the alluvial aquifer toward the Meramec River.,
MDNR and EPA experience would indicate that this alternative
would take in excess of 50 years to restore soil and ground water
to ARARs and PSs on the WaD. The contaminated ground water
located off the wau will be addressed in a future operable unit
of the larger Valley Park TCE Site.
Alternative 2
Present Worth Cost: $ 785,354
This is a limited action alternative which reduces the potential
exposure to contaminants through implementing a deed restriction
which prohibits the installation and use of a ground water supply
well on the wau. Alternative 2 also includes a ground water
monitoring program different than the one described for the
common elements in that sampling from only existing wells MW-
AAB, MW-AAC, MW-5 and MW-17 on a quarterly frequency will be
required. The restoration of impacted soil and ground water
would be accomplished through natural attenuation processes.
Through natural attenuation, ground water contaminants would be
transported off the wau through the alluvial aquifer toward the
Meramec River. MDNR and EPA experience would indicate that this
alternative would take in excess of 50 years to restore soil and
ground water to ARARs and PSs on the WaD. The contaminated
ground water located off the waD will be addressed in a future
operable unit of the larger Valley Park TCE Site.
Alternative 3
Present Worth Cost: $ 4,029,880
This is an active soil and ground water restoration alternative
which consists of the common elements, excavation and
treatment/disposal off the waD of shallow contaminated soil on
the wau, extraction ~nd treatment of waD contaminated ground
water 'with discharge to the publicly awned Treatment Works
(paTW), soil vapor extraction of wau contaminated subsurface
soils, and air sparging to accelerate the ground water cleanup.
Detailed characterization of the aquifer and vadose zone would be
required during the design phase.
Surface and near-surface soils fr0m the north side of the
Wainwright building would be excavated to reduce zones containing
high vac concentrations. This will be a new excavation activity
19
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which is in addition to ~he original removal excavation activity
conducted in 1990. For cost estimating purposes, it was assumed
soils exceeding 1000 ppm PCE in the upper five feet of soil would
require excavation. .These assumptions produced an estimate of
350 cubic yards of excavated soils. Clay would be backfilled
into the excavated areas. The excavated soils would be
transported to an MDNR and EPA approved off-site treatment and
disposal facility.
The technology identified for soil treatment at the off-site -
hazardous waste treatment facility is low-temperature thermal
desorption. This technology is assumed mainly for cost
estimating purposes. The final treatment technology selected for
the excavated soil may change depending on the facility selected
and subject to MDNR and EPA approval.
The remaining subsurface contaminated soils located above the
ground water table would be remediated using soil vapor
extraction (SVE). This system would consist of a series of
extraction and inlet wells installed within the vadose zone
(unsaturated soils above the ground water table) north of and
beneath the Wainwright building. A vacuum would be applied to
the extraction wells, thereby creating an air flow through the
vadose zone. As air moves through the soils, contaminants would
be transferred from the adsorbed phase to the vapor phase.
Air emissions from the SVE system would comply with regulations
of the st. Louis County Department of Community Health & Medical
Care, Air Pollution Control Agency, MDNR and EPA. Air withdrawn
from the subsurface would be discharged via a properly designed
stack that would insure acceptable ambient air concentrations of
contaminants both on and off the WOU. For cost estimating
purposes, it was assumed that emission control devices would not
be required.
Contaminated WOU ground water would be hydraulicaliy controlled
and collected through the entire vertical section of the aquifer
on the WOU. For cost estimating purposes, it was estimated that
one extraction well pumping 175 gallons per minute (GPM) would
hydraulically control the WOU ground water. Extracted ground
water would be treated on the WOU-using an air stripper system.
The air stripper would remove the VOCs from the ground water and
transfer them to the vapor phase. Air emissions from the air
stripper would be ~anaged in the same manner as the SVE
emissions. The treated ground water would then be discharged
into the POTW system, operated by the st. Louis Metropolitan
Sewer District (MSD) for treatment and ultimate disposal into the
Meramec River.
In addition to the SVE and ground- water extraction (GWE) systems,
a ground water air sparging system would be installed in the area
directly north of and beneath the Wainwright building.
20
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Compressed air would be .injected into the aquifer through
sparging wells. VOCs' adsorbed to the soils below the. ground
water table and dissolved in the ground water would be
transferred to the vapor phase and transported to the vadose
,zone. The SVE system would remove the VOCs from the vadose zone.
It is important to note that the technical feasibility of
operating a ground water sparging system is dependent upon the
seasonal depth to ground water and the design of the SVE system.
E£fective design of the SVE system would prevent potential..
contaminant confinement and lateral dispersion induced by the
overlying silt/clay unit. However, it is possible that risks
associated with air sparging (i.e., ground water mounding and
uncontrolled soil gas emissions) could outweigh the potential
benefits. The remedial design would analyze this issue and
obtain the necessary information using a pilot study and/or
additional field work. Air sparging would be eliminated from the
remedial action if the risks are determined to be unacceptable.
The contaminated ground water located off the WOU will be
addressed in a future operable unit of the larger Valley Park TCE
site. The active remediation of the WOU soils and ground water
would significantly reduce the cleanup timeframe as compared to
Alternatives 1 and 2. .
Alternative 4
Present worth Cost: $ 3,685,162
Alternative 4 is an active remediation alternative identical to
Alternative 3 except that soil excavation and treatment/disposal
off .the WOU would not occur.
The active remediation of the WOU soils and ground water would
significantly reduce the cleanup time frame as compared to
Alternatives 1 and 2. The cleanup time-frames for Alternatives 3
and 4 would be comparable. The contaminated ground water located
off the WOU will be addressed in a future operable unit of the
larger Valley Park TCE site.
Alternative 5
Present Worth Cost: $ 1,469,513
Alternative 5 is an active remediation alternative which includes
the common elements, SVE and air sparging. Alternative 5 is
identical to Alternative 3 except that soil excavation and
treatment/disposal off the WOU and ground water extraction would
not occur.
The active remediation of the.WOU ground water and soils would
reduce the cleanup timeframe as c~mpared to Alternatives 1 and 2.
The cleanup timeframe for Alternative 5 would be slower than
Alternatives 3 and 4 due to the absence of the ground water
21
-------
extraction system. TPe contaminated ground water located off the
WOU will be addressed in a future operable unit of the larger
Valley Park TCE Site.
Alternative 6
Present Worth Cost: $ 3,583,356
Alternative 6 is an active remediation alternative which includes
the cornmon elements, SVE and ground water extraction and.
treatment. Alternative 6 is identical to Alternative 3 except
that soil excavation and treatment/disposal and air sparging
would not occur.
The active remediation of the WOU ground water and soils would
reduce the cleanup tirneframe as compared to Alternatives 1 and 2.
The cleanup timeframe for Alternative 6 could be slower than
Alternatives 3 and 4 due to the absence of the air sparging
system. The contaminated ground water located off the WOU will
be addressed in a future operable unit of the larger Valley Park
TCE Site.
Alternative 7
Present Worth Cost: $ 1,370,715
Alternative 7 is an active remediation alternative which
the cornmon elements and SVE. Alternative 7 is identical
Alternative 5 except that air sparging would not occur.
The active remediation of the WOU soils would reduce the soils
cleanup timeframe as compared to Alternatives 1 and 2. Through
natural attenuation, ground water contaminants on and off the WOU
would be transported through the alluvial aquifer toward the.
Meramec River. MDNR and EPA experience would indicate that this
alternative would take in excess of 50 years to achieve ground
water ARARs. The contaminated ground water located off the WOU
will be addressed in a future operable unit of the larger Valley
Park TCE Site.
includes
to
Alternative 8
Present Worth Cost: $ 2,168,010
Alternative 8 is an active remediation alternative which includes
the common elements,. ground water extraction and treatment, SVE
and air sparging. Alternative 8 is identical to Alternative 4
except that treated ground water would be reinjected into the
aquifer underneath the WOU rather than discharged into the POTW.
The air stripper effluent would be sampled for parameters
consistent with the regulations of the Underground Injection
Control (UIC) Program, managed jointly by the MDNR - Division of
Geology and Land Survey (DGLS) and the MDNR - Division of
Environmental Quality. Reinjection is a complicated issue
22
-------
because it could either accelerate ground water remediation or
alter the direction of the WOU ground water which would prevent
the ground extraction system from achieving hydraulic control of
the contaminated ground water.
The active remediation of the WOU soils and ground water would
significantly reduce the cleanup timeframe relative to
Alternatives 1 and 2. The cleanup time-frames for Alternatives
3, 4 and 8 would be comparable. The contaminated ground water
located off the WOU will be addressed in a future operable unit
of the larger Valley Park TCE Site.
Alternative 9
Present Worth Cost: $ 2,068,186
Alternative 9 is an active remediation which includes the common
elements, ground water extraction and treatment, and SVE.
Alternative 9 is identical to alternative 6 except that treated
ground water would be reinjected into the aquifer underneath the
WOU rather than discharged into the POTW.
-
The air stripper effluent would be sampled for parameters
consistent with the regulations of the Underground Injection
Control (UIC) Program, managed jointly by the MDNR - Division of
Geology and Land Survey (DGLS) and the MDNR - Division of
Environmental Quality. Reinjection is a complicated issue
because it could either accelerate ground water remediation or
alter the direction of the WOU ground water which would prevent
the ground extraction system from achieving hydraulic control of
the contaminated .ground water.
The active remediation of the WOU ground water and soils would
reduce the cleanup timeframe relative to Alternatives 1 and 2.
The cleanup timeframe for Alternative 9 could be slower than
Alternatives 3, 4, and.8 due to the absence of the air sparging
system. The contaminated ground water located off the WOU will
be addressed in a future operable unit of the larger Valley Park
TCE Site.
Alternative 10
Present Worth Cost: $3,992,649
Alternative 10 is an active remediation which includes the common
elements, ground water extraction and treatment, SVE, air
sparging and soil excavation/treatment/disposal. This will be a
new excavation activity which is in addition to the original
removal excavation activity conducted in 1990. Alternative 10 is
a modification of Alternative 3. The modifications focus on the
risk associated with surface soils, the potential for
contamination to travel along the sewer trench traversing the
WOU, and a contingency for remedial actions related. to
contamination of ambient air at properties within the WOU.
23
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Chemical analyses of shallow soil samples, taken from the 6"-12"
interval below surface grade documented elevated levels of VOCs
on the Wainwright property, and elevated levels of VOCs and PARs
adjacent to the fence between the Wainwright property and the
Cotton and Netzer properties. During the remedial design for
this alternative, surface soil samples, to be taken from the 0"-
6" interval below surface grade, would be obtained from the
Wainwright, Netzer, Cotton and st. Louis Boat and Canoe
properties and analyzed for PARs and VOCs. Based on these
sampling results, surface soils with VOC and/or PAH levels
exceeding the direct contact soil performance standards, defined
later in this section in the ARARs and PSs subsections on Pages
25 to 29, would be addressed in the following manner:
3 .
1.
VOC-contaminated surface soils located on the
wainwright property would be covered to prevent contact
without excavation occurring. At least a four inch
layer of gravel was assumed for cost estimating
purposes. An uncontaminated soil cover could be used
instead of gravel if mixing of the uncontaminated soil
with contaminated soils would not complicate the
remedial action. The contaminated surface soils must
achieve the direct contact performance standards within
five years from startup of the SVE system. If
performance standards are not achieved within five
years, a one foot depth of the original contaminated
surface soils located on the Wainwright. property would
be excavated and taken to a treatment facility off the
WOU. The excavation would be backfilled to the
original grade and revegetated consistent with the
existing property;
2.
PAH contaminated surface soils located on the
wainwright property would be excavated and taken to a
treatment facility off the WOU. All PAH contaminated
surface soils would be excavated until direct exposure
performance standards could be met. For cost
estimating purposes, it was assumed a one foot deep
excavation would be required. The excavation would be
backfilled with clean soils~o the original grade and
revegetated consistent with the existing property; and,
VOC and PAH contaminated surface soils located on the
WOU but off the Wainwright property would be excavated
to one foot below surface and taken to a treatment
facility off the WOU. The excavation would be
backfilled with clean soils to the original grade and
revegetated consistent with the existing property.
For cost estimating purposes, it'was estimated that 95 cubic
yards of soil would require excavation and treatment. The
technology identified for soil treatment at the hazardous waste
24
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treatment facility off t~e WOU is low-temperature thermal
desorption. This technology is assumed for cost estimating
purposes. The final treatment technology selected for the
excavated soil may cbange depending on the facility selected and
subject to MDNR and EPA approval.
During the remedial design, the sewer trench soils would be
characterized to ascertain the concentration and horizontal
extent of contamination. This information would be used in
designing the SVE system.
In addition, ambient air samples from the interior of buildings
on the WOU will be analyzed for WOU contaminants during the
remedial design. MDOH health-based ambient air criteria will be
used to determine the need for remedial actions to prevent
unacceptable exposure risks. Remedial action costs for ambient
air risks were generally estimated in the contingency costs and
were not technology specific. .
The active remediation of the WOU soils and ground water in
Alternative 10 would significantly reduce the cleanup timeframe
relative to Alternatives 1 and 2. The cleanup time-frames for
Alternatives 3, 4, 8 and 10 would be comparable if air sparging
is approved in the remedial design. The contaminated ground
water located off the WOU will be addressed in a future operable
unit of the larger valley Park TCE Site.
-
Applicable or Relevant and Appropriate Reaulations (ARARs)
Section 121(d} (2) of CERCLA requires that remedial actions
conducted achieve ARARs. ARARs are legally enforceable Federal
or State substantive environmental standards, requirements,
criteria or limitations. ARARs are divided into three types:
contaminant-specific, location-specific and action-specific. A
CERCLA remedial action is required to meet the substantive
requirements of ARARs for activities conducted on-site~ both
substantive and administrative requirements are required when
activities occur off-site. The following listing includes both
State of Missouri and Federal ARARs. When both State and Federal
ARARs address the same issue, the-more stringent ARAR would
apply. In addition, there are other applicable non-environmental
laws that must be followed which are in a separate section
entitled "Applicable Non-Environmental Laws."
contaminant-specific
1)
The Federal Safe Drinking Water Act (SDWA) non-zero
Maximum Contaminant Level Goals (MCLGs) and Maximum
Contaminant Levels (MCLs), 4~ CFR 9141.50 - 141.51 and
40 CFR 9 141.11 - 141.16, apply to the ground ~ater
underneath the WOU only. Also, the Missouri Water
25
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Quality standards for drinking water
CSR 20-7.031, set MCLs and Secondary
contaminant Level (SMCL) which apply
water underneatp the WOU.
supplies, Title 10
Maximum
to the ground
For example, the MCLs and SMCLs for several
contaminants of concern in the WOU ground water are
listed in Table 6.
Table 6.
MCLs and SMCLs for several contaminants
of Concern in the WOU Ground Water
contaminant
MCL
SMCL
----------------
-------
--------
TCE
PCE
Methylene Chloride*
Barium*
Manganese
5 ppb
5 ppb
5 ppb
1 ppm
50 ppm
*
Identified in the Risk Assessment as a
potential risk to human health. Methylene
Chloride was detected in only one sample in
the RI and may be a laboratory contaminant.
2)
The Federal Clean Air Aqt, 40 CFR ~ 50-99 and the State
Implementation Plan (SIP), and the Missouri Air Quality
Standards, 10 CSR 10.6, establish air quality standards
which apply to air emissions released during WOU
activities. In addition, the EPA Office of Air Quality
Planning and Standards (OSWER) Directive 9355.0-28
specifies that air emissions controls will be utilized
on Superfund sites when total VOC emissions exceed 10
tons/year for sites in non-attainment zones. This
Directive is a To Be Considered standard which shall be
followed since it is a non-promulgated document setting
a level for emission necessary for protection. Refer
to the Performance Standards subsection which follows
the ARARs subsection for additional air emissions
requirements.
3)
There are no standard soil restoration levels.
Instead, soil restoration levels are developed for each
site. The soil restoration levels developed for the
WOU are presented later in this section in the
Performance Standards subsection.
26
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4)
5)
Location-specific
1)
Due to the location within the 100 year flood plain of
the Meramec Ri~er, the remedial activities will meet
the substantive requirements of 40 CFR 9 264.18(b) of
the Resource, Conservation and Recovery Act (RCRA) as
administered by MDNR.
~)
In accordance with the Fish & wildlife Coordination
Act, Section 662, and the Endangered Species Act, the
Missouri Conservation Commission and the U.S. Fish and
Wildlife Service will be consulted prior to initiating
any remedial activities. This step is required due to
the potential impact of soil excavation activities on
the surface waters of the Meramec River during a
flooding event.
Action-Specific
1)
Ground Water Monitoring:
The substantive ground water monitoring requirements
apply as specified in 10 CSR 25-7.264 (1) (F).
2)
pnderground Injection of Ground Water 'and/or Air:
The substantive Underground Injection Control
requirements apply as specified in 10 CSR 20-6.070,
-6.090 and -6.011.
3)
Discharge to POTW:
Any substantive and administrative requirements of 40
CFR 9 403.5 and the local POTW pretreatment program
will apply.
Installation of Ground Water Monitoring and Extraction
Wells, Air Sparging Wells and SVE Wells:
The Missouri Well Construction Rules promulgated and
existing under the authority of RSMo 9 256.600 to
256.640.
Excavation, Transport and Disposal of Soils:
A MDNR hazardous waste transporter license, 10 CSR 25-
6, will be required prior to excavating soil.
Additionally, the RCRA land ,disposal restrictions, 10
CSR 25-7.268, and the CERCLA Offsite Rule, 40,CFR
27
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9 300.440 of the NCP, 58 F.R. 49200 (9/26/93), apply to
excavated soils.
6)
Operation of SVE, Air stripping and Air Sparging
Systems:
The substantive requirements of the Missouri Air
Qual'ity Standards, 10 CSR 10.6, the Federal Clean Air
Act, 40 CFR 9 61 and 63 and the SIP, and Federal RCRA
regulations 40 CFR 9 264, Subparts AA and BB, will
apply.
7)
Excavation, Transport and Disposal of Soils:
Wastes disposed off-site or treated on-site will be sampled
as per the substantive requirements of 10 CSR 25-7.264
(l)(B).
The substantive requirements of 10 CSR 20-6.200 (2) (B)3.A.,
involving storm water runoff control will apply.
Applicable Non-Environmental Laws
1)
General Design and Construction:
The substantive requirements of the local St. Louis
County and/or City of Valley Park 'zoning and building
codes would be met prior to construction.
As per 10 CSR 25 7-270(2) (B)6, all submitted engineering
plans and reports shall be approved by a registered
, professional engineer licensed by the State of Missouri: and
the plans shall specify design standards as described 'in'
this regulation.
Performance Standards
Performance standards are technical criteria used in parallel to
ARARs to make decisions during the design and/or implementation
of remedial actions. Performance., standards normally address
issues for which there are no ARARs. The following list of
performance standards apply to the remedial action options
evaluated for the WOU:
soil
Several treatment options evaluated address soil contamination.
The contaminants of concern for the WOU are VOCs and PAHs in
general, and PCE, TCE, and Benzo(a)pyrene, most notably. Soil
performance standards are used t~ identify unacceptable
concentration of contaminants in soil. There are no standard
28
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soil performance standards which apply to all sites; instead,
soil performance standards are developed for each site. For the
WOU, direct contact to surface soils and migration from soils to
ground water are unacceptable threats posed by contaminated
soils. As a result, "the soil performance standards are based on
these two threats.
The methods used to develop the soil performance standards for
the WOU are described in detail in Chapter two of the Final
Feasibilitv Report for the Wainwriqht Operable Unit (May 9,
1994), Sections 2.2.2.1 and 2.2.2~2. These methods can be used
to develop soil performance standards for all VOC and PAH
contaminants of concern. For example, soil performance standards
are presented for key contaminants at the WOU in Table 7.
Table 7.
soil Performance Standards for Key WOU contaminants.
Ground Water Direct Contact
contaminant Threat (PPM) Threat (PPM)
---~------------- ------------ --------------
Trichloroethylene 0.255 52.63
Perchloroethylene 0.737 10.64
Benzo(a)Pyrene 22.8 0.065
*
As an example, Table 7 presents soil performance
standards for only three contaminants. However, soil
. performance standards exist for all WOU contaminants
using the method described above.
All surface and subsurface soils on the WOU must achieve the soil
performance standards based on the threat to ground water prior
to completion of the remedial action. However, surface soils on
and off the WOD must achieve the soil performance standards based
on the direct contact threat in a more expeditious timeframe than
the performance standards based on the threat to ground water.
Air Emissions
The Missouri and Federal air emissions ARARs have been defined
previously. In addition, the risks associated with the exposure
to air emissions would be calculated during the design for the
remedial action and used to determine the need for air emissions
control equipment and ambient air remedial activities specified
for Alternative 10. The EPA Industrial Source Complex Short Term
or Long Term computer models (ISCST or ISCLT) or other EPA
approved models will be used to develop the risk calculations for
the soil and ground water remedial activities. MDOH will develop
the ambient air performance standards for the contingency
outlined in Alternative 10. The calculations will be based upon
air emission exposures on and off the WOU which produce
29
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acceptable risks: cancer risk less than 1 in 1,000,000 and non-
cancer index less thaR 1~0.
SECTION 8.0
SUMMARY OF THE COMPARATIVE ANALYSIS
OF ALTERNATIVES
To select a remedy, all remedial alternatives must be compared to
each other using nine evaluation criteria defined in Section
300.430(e) of the NCP. The nine criteria are divided into three
g~oups: (1) Threshold Criteri~ include overall protection of -
human health and the environment and compliance with ARARs-
alternatives which do not satisfy these criteria are eliminated;
(2) Primary Balancing Criteria include long-term effectiveness
and permanence, reduction of toxicity, mobility, or volume, short
term effectiveness, implementability, and cost - these criteria
are used to weigh major tradeoffs among alternatives; and, (3)
MOdifying criteria include state acceptance and community
acceptance - these criteria are taken into account after the
public comment period. The selected remedy is the alternative
that meets the threshold criteria and that then provides the best
balance of trade-offs among the remaining criteria in this
comparative analysis.
Threshold criteria
- Overall protection of Human Health and the Environment:
Alternative 1 is the no action alternative. This would not be
protective of human health or the environment. Future use Qf the
aquifer on the weu poses unacceptable risks to public health.
Contaminated soils pose a risk to neighboring residents,
neighboring commercial business employees and tenants of the
Wainwright property. Uncontrolled contaminated soils and ground
water on the weu would leach contaminants to ground water off the
weu. Alternative 1, therefore, is not considered further in this
analysis.
Alternative 2 involves ground water monitoring and deed
restrictions on ground water supply wells on the weu.
Contaminated surface soils would still pose a risk at the weu,
and contaminated soils and ground water on the weu would still
pose unacceptable risks to human health off the weu. Therefore,
Alternative 2 is not considered for further analysis.
Alternatives 3 and 10 reduce the risk to human health through
soil excavation (or capping) and subsequent treatment/disposal
off the weu, soil vapor extraction on the weu, ground water
extraction and treatment (air stripping and discharge to a peTW)
on the weu, and air sparging on tbe weu. Alternatives 3 and 10
would be the most protective of human health and the environment
through relatively quick remediation of both the soil and ground
30
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water exposure pathways. Only Alternatives 3 and 10 would reduce
the risks from PAH contaminants in soils. Soil vapor. extraction
without excavation as indicated in Alternatives 4, 5, 6, 8, and 9
would not successfully remediate PAHs.
Alternatives 4, 5, 6, 8, and 9 also have components which would
reduce exposure risks by remediating both the ground water and
the soils of the WOU. Alternatives 4, 5, 6, 8, and 9 do not
involve any excavation of soil and, therefore, would be less
protective of human health during the extended time it would take
to. achieve cleanup goals for VOCs. Furthermore, alternatives..
which lack excavation may not effectively remove the soil
exposure risk from PAR contaminants. Alternatives 6 and 9 do not
involve air sparging which may decrease t~e likelihood of
successfully treating the WOU ground water to achieve ARARs.
Alternatives 5 and 7 would remediate soils at the WOU but do not
include ground water extraction (and subsequent air stripper
treatment and POTW discharge). Some minor reduction of the
ground ~ater exposure route would be gained by air sparging and
SVE in Alternative 5 and, to a lesser degree, by SVE without air
sparging in Alternative 7. However, it is doubtful that VOCs
could be reduced significantly in ground water to acceptable
levels using Alternative 5, and highly unlikely using Alternative
7 .
Only. Alternative 10 directly monitors VOC contaminants found in
ambient air within buildings on the WOU. Ambient air monitoring
in the buildings would allow for a response action, if necessary,
which would reduce unacceptable risks posed by WOU VOC
contaminants.
All the proposed remedial alternatives that actively treat ground
water limit the scope of ground water remediation to the ground
water beneath the WOU. Therefore, ground water impacts off the
WOU and associated risks to human health will not be fully
eliminated by any of the proposed alternatives. Ground water
contamination throughout the entire Valley Park area will be
addressed in future actions in a separate operable unit.
-compliance with ARARs:
Federal drinking water standards (MCLs) for TCE, PCE, and
Methylene Chloride each are 5 ppb. The MCL for barium is 1000
ppb and the Secondary MCL for manganese is 50 ppm. Alterna~ive 7
would not adequately achieve reduction of these chemicals in
ground water and, therefore, is eliminated from further
consideration. Alternative 5 may be able to achieve drinking
water standards for VOCs, but not for barium and manganese.
However, barium and manganese may not be a problem if future
dissolved metals analysis show a reduction in these
concentrations. Alternatives 3, 4, 6, 8, 9, and 10 all will
31
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achieve federal and state drinking water standards for the ground
water beneath the WOU. only.
Alternatives 8 and 9 may not meet MDNR Underground Injection
Control (UIC) prohibitions on reinjecting waste underground.
Ground water reinjection is only permitted if it can be shown to
significantly increase the efficiency of the ground water
remediation process. .
Alternatives 3, 4, 5, 6, 8, 9, and 10 will be designed to satisfy
the substantive requirements for all location specific and action
specific ARARs. Of specific concern are air emissions from the
air stripper and SVE system which would be closely monitored and
engineered to ensure compliance with all federal, state, and
local standards.
Balancing criteria
-Long-term Effectiveness and Permanence
For all the remaining alternatives, 3, 4, 5, 8, 9, and 10,
untreated materials or long-term residual hazardous substances
would not be expected to remain at the WOU assuming successful
remediation of the soils and ground water.
Alternative 5 may prove less effective at treating ground 'water
over the long-term than the other alternatives since it does not
include ground water extraction. Often attaining cleanup goals
with DNAPL contaminants is difficult over the long-term. For
example, concentrations of TCE or PCE may decline during
remediation, but often go back up when pumping ceases.
Therefore, ground water remediation using both air sparging and
ground water extraction, as included in Alternatives 3, 4, 8, and
10, may be more effective than Alternatives 6 and 9 in the long-
term.
Alternatives 3 and 10 require treatment and disposal off the WOU
for excavated soils. The treatment method used at the disposal
facility could influence the long-term effectiveness of these
alternatives.
Alternative 10 has the additional component of contaminant
characterization and SVE concentrated along areas of horizontal
conduits (buried utility lines). These areas are the most likely
zones of contaminant migration and elevated concentrations.
Therefore, focusing on these zones should increase the
effectiveness of soil and subsequent ground water remediation.
-Reduction of Toxicity, Mobility, or Volume Through Treatment:
Under Alternative 3, approximately 350 cubic yards and under
Alternative 10 approximately 95 cubic yards of soil'would be
32
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excavated and transported to an
facility. At the landfill, the
temperature thermal desorption.
from the soil to the air.
approved hazardous waste landfill
soil would be treated. using low
This technology transfers VOCs
Alternatives 3, 4, 5, 6, 8, 9, and 10 involve transfer of VOCs
from soil .and ground water into the atmosphere. If permit
requirements and/or acceptable risks for air emissions cannot be
met, a portion of the VOCs will be treated through carbon
adsorption or other permanent removal methods.
The mObility and volume of the contaminants in the soil and
ground water would effectively be reduced under all of the
remaining alternatives. However, these cleanup actions would not
reduce the toxicity of the contaminants.
Alternatives 3, 4, 5, 6, 8, 9, and 10 satisfy the National
Contingency Plan (NCP) preference for treatment.
-Short-term Effectiveness
Alternatives 3, 4, 5, 6, 8, 9, and 10 pose a short-term risk to
remedial action workers on the WOU and neighboring residents
through exposure to VOC vapors. Remedial Action workers should
be protected by the use of appropriate personal protective
equipment. Nearby residents should be protected by emissions and
dust control, restricted access, and proper design and monitoring
of SVE and air stripper systems. If air emissions permit
limitations cannot be met and/or acceptable risks are not
achieved, additional controls will be placed on these systems to
protect pUblic health.
A contingency plan would be developed for the WOU that includes
procedures for protecting the public during an emergency.
Additional risks. to remedial action workers may be presented by
soil excavation included in Alternatives 3 and 10. Physical
hazards during the excavation process would be mitigated by the
use of proper protective gear and the implementation of a health
and safety program.
Alternatives 3, 4, 5, 8, and 10 all include air sparging. It is
possible that air forced into the ground water could cause ground
water mounding and/or mobilize VOCs off the WOU along horizontal.
conduits (sewer lines or other buried utilities). In light of
past concerns with vapors in neighboring households, strict
controls would be placed on air sparging. Extensive pilot-scale
studies would be conducted to ensure vapors are not transported
off the WOU before full-scale implementation of air sparging.
Reinjection of ground water into the aquifer underneath the WOU
included in Alternatives 8 and 9 would result in ground water
33
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mounding, which may also cause mobilization of voe vapors off the
WOU.Reinjection and subsequent ground water mounding may also
create changes in the hydraulic gradient which could'mobilize
contaminated water away from the extraction well. Extensive
geologic characterizution and careful design would be necessary
to capture all the reinjected water.
Alternatives 3, 4, 6, and 10 would increase the load handled by
the Valley Park MSD wastewater treatment facility. The normal
inflow to the facility is 15 million gallons per day (MGD), which
is 94% of its capacity. The effluent from the WOU ground water
extraction would be 175 gpm or 0.25 MGD which is an extra 1.6% of
the MSD facility's capacity. Also, the sanitary sewer line
traversing the weu property is an eight inch diameter pipe which
could adequately receive the 175 gpm discharge. The WOU
discharge would not significantly impact the capacity of the MSD,
except during high flow conditions. The weu ground water
extraction system could, be designed to shut down during flooding
events which increase the flow to the POTW.
Environmental impacts for all the remaining alternatives would be
low. Ground water extraction may alter hydraulic gradients
locally, but should not negatively impact nearby water uses. SVE
may increase voe concentrations near the extraction wells, but
this should not have any negative consequences. Air emissions
should be of relatively low volume and not be a significant
increase in the vee load in the broader area. If voe emissions
exceed 10 tons per year or other permit limitations, engineere~
controls may be required to reduce emissions.
-Implementability
Implementation concerns for the remaining alternatives are
relatively low. The equipment, materials and labor skills are
~eadily available and the procedures to be followed are common.
There are some relative differences with implementation between
the alternatives and technical difficulties associated with
various remediation activities. These are listed below in order
of decreasing difficulty in implementation (i.e. the most
difficult first):
(1) Reinjection of ground water included in Alternatives 8 and 9,
as mentioned above, ,must be very carefully designed to ensure
capture of all ground water influenced by mounding. In addition,
substantive requirements to satisfy stringent design parameters
specified by the State VIe program may be prohibitive.
(2) Air sparging included in Alternatives 3, 4, 5, 8, and 10 also
must be carefully designed and monitored to avoid migration of
vapors underground away from soil vapor extraction wells. In
addition, ground water must be below the base of the silty clay
34
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soil horizon. If not, extraction of vapors through the SVE wells
may be impeded.
(3) Elevated ground water may also pose a problem to the 5VE
system included in all the remaining alternatives. Vapors cannot
be extracted through a saturated medium. In addition, the
relatively tight silty clays in the upper soil zone may slow or
inhibit the effectiveness of the SVE process. Specialized
technology (i.e., soil fracturing) ~ay be needed to assist in
enhancing the SVE process in low permeability soils.
(4) 50il excavation and off-site disposal included in
Alternatives 3 and 10 is a very common remediation technique. No
problems in implementation should occur in this remedial action,
unless adverse weather conditions (flooding) predominate during
excavation.
-Cost
The estimated present-worth cost for the remaining alternatives
are given below in Table 8 below:
TABLE 8.
Costs of Remedial Alternatives
Alternative Cost $
3 4,029,880
. 4 3,685,162
5 1,469,513'
6 3,583,356
8 2,168,010
9 2,068,186
10 3,992,649
The present-worth cost estimates include direct and indirect
capital costs, contingency allowances, and annual operation and
maintenance costs projected throughout the estimated life of the
project. Assumptions used in the cost estimates were an
operational time frame of three years for soil venting and air
sparging, 10 years for ground water pump and treat, and 30 years
for ground water monitoring. -
MOdifying criteria
-state Acceptance
The MDNR, representing the State of Missouri, supports the
selected remedy described in Section 9.0, below.
35
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-communi~y Acceptance
The reservations, concerns, and supporting or opposing comments
of the community on ~he RI/FS, the Proposed Plan, and other
information in the Administrative Record were made known to EPA
and the State of Missouri during the thirty day comment period
.and at the public meeting. The pUblic's comments are addressed
in the responsiveness summary, which is a component of the Record
of Decision (ROD) for the WOU. There have been no comments which
required EPA to change the Preferred Alternative identified in
the Proposed Plan. -
SECTION 9.0
THE SELECTED REMEDY
The EPA has determined that the selected remedy for the WOU is
Alternative 10. This selected remedy will provide overall
protection of human health and the environment by eliminating,
reducing, or controlling all current and potential risks posed by
the exposure pathways at the WOU, and will be in compliance with
all ARARs and Performance Standards.. Alternatives 3 and 10 are
the most protective of human health and the environment.
However, Alternative 10 achieves an equal or greater level of
protectiveness as Alternative 3, but with a potentially lower
cost. Overall Protection of Human Health and the Environment and
Long-Term Effectiveness and Permanence of the selected remedy
were critical factors in balancing the trade-offs among the
alternatives. .
The selected remedy includes:
A. Soil vapor extraction (SVE) will be conducted throughout the
identified areas of VOC contaminated soil on the WOU. SVE shall
be conducted until VOCs are reduced to concentrations below the
performance standards based on the threat to ground water.
Additional characterization of horizontal migration pathways will
be performed during the design of the remedial action. Special
attention in the SVE design will focus on horizontal migration
pathways, including the old sewer line through the WOUi
B. During the remedial design, surface soil samples, to be taken
from the 0"-6" interval below surface grade, would be obtained
from the Wainwright, Netzer, Cotton and st. Louis Boat and Canoe
properties and analyzed for PAHs and VOCs. Based on these
sampling results, surface soils with VOC and/or PAH levels
exceeding the direct contact soil performance standards would be
addressed in the following manner:
1. VOC-contaminated surface soils located on the
Wainwright property would b~ covered to prevent contact
without excavation occurring. At least a four inch
layer of gravel was assumed for cost estimating
36
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purposes. An uncontaminated soil cover could be used
instead of grave~ i£" mixing of the uncontaminated soil
with contaminated soils would not complicate the"
remedial action. The contaminated surface soils must
achieve the direct contact performance standards within
five years from startup of the SVE system. If
performance standards are not achieved within five
years, a one foot depth of the original contaminated
surface soils located on the Wainwright property would
be excavated and taken to a treatment facility off the
Wou. The excavation would be backfilled to the
original grade and revegetated consistent with the
existi~g property:
2. PAH contaminated surface soils located on the
Wainwright property would be excavated and taken to a
treatment facility off the WOU. All PAH contaminated
surface soils would be excavated until direct exposure
performance standards could be met. For cost
estimating purposes, it was assumed a one foot deep
excavation would be required. The excavation would be
backfilled with clean soils to the original grade and
revegetated consistent with the existing property.;
and,
3. VOC and PAH contaminated surface soils located on
the WOU but off the Wainwright property would be
excavated to one foot below surface and taken to a
treatment facility off the WOU. The excavation would
be backfilled with clean soils to the original grade
and revegetated consistent with the existing property.
For cost estimating purposes, it was estimated that 95 cubic
yards of soil would require excavation and treatment. The
technology identified for soil treatment at the hazardous waste
treatment facility off the WOU is low temperature thermal
desorption. This technology is assumed for cost estimating
purposes. The final treatment technology selected for the
excavated soil may change depending on the facility selected and
is subject to MDNR and EPA approval;
C. A ground water extraction and treatment system which will
hydraulically control the entire vertical section of the aquifer
and restore to MCLs the impacted ground water underneath the WOU
will be implemented. The extraction system will include at least
one extraction well located on the WOU. Air stripping technology
will be used to treat the extracted, contaminated ground water to
meet POTW ARARs. The treated water will be discharged to the
Metropolitan Sewer District POTW serving the City of Valley Park.
The contaminated ground water located off the WOU will be
addressed in a future operable unit of the larger Valley Park TCE
Site;
37
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D. An air sparging system would be installed to inject
compressed air into the ground water below the area directly
north of and beneath the Wainwright building. Intensive pilot
scale studies are particularly necess.ary for this technology.
Off-site, lateral migration of vapors through horizontal
conduits, such as utility lines, would be studied during the
design of the remedial action using pilot scale studies. If
lateral vapor migration to horizontal conduits can not be
controlled using SVE, the air sparging technology will not be
included in the remedial action;
E. A deed restriction would be placed on the WOU by the property
owners to prohibit the installation and operation of ground water
supply wells on the WOU;
F. Ground water monitoring would be conducted to assess the
effectiveness of the remediation. The monitoring well network
would include existing and new ground water monitoring wells
including a new set of two wells located directly north of the
wainwright building. One of the new wells would be finished to
the top of bedrock to monitor the potential existence of free-
phase DNAPL underneath the WOU. The second new well would be
screened in the water table above the bedrock well: and,
G. Ambient air samples from the interior of buildings on the WOU
will be analyzed for WOU contaminants during the remedial design.
Missouri Department of Health health-based ambient air criteria
will be used to determine the need for remedial actions to
prevent unacceptable ambient air inhalation exposure risks.
The present worth. cost estimate of $ 3,992,649 for the selected
remedy includes estimates of $ 640,013 for total capital costs
and $ 3,352,636 for operation and maintenance costs. The
operation and maintenance costs are based on assumed operational
time frames of three years for soil venting and air sparging, ten
years for ground water pump and treat, and thirty years for
ground water monitoring.
The EPA will conduct a five-year review, consistent with the
standards set forth in Section 121(c) of CERCLA, 42 U.S.C.
962l(c). The effectiveness of the selected remedy will be re-
evaluated at that time.
SECTION 10.0
STATUTORY DETERMINATIONS
Protection of Human Health and the Environment:
The selected remedy, through the use of ground water
extraction and treatment, SVE, air sparging and soil excavation,
treatment, and disposal will provide overall protection of human
health and the environment. The above remediation methods used
38
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in the selected remedy, as compared to the other alternatives,
provides the most pro~ection to human health and the environment
by eliminating, reducing or controlling the potential "risks posed
by exposure to VOCs (notably, TCE & PCE), metals and PAHs at the
WOU. The carcinogenic and non-ca~cinogenic risks from exposure
to VOCs, metals and PAHs at the WOU will be reduced to within the
acceptable levels. The selected remedy will not pose
unacceptable short-term risks or cross-media impacts.
compliance with Applicable or Relevant and Appropriate
Requirements (ARARs):
The selected remedy will comply with all federal and state
ARARs as follows:
Contaminant specific:
1)
For the ground water underneath the WOU only,
A. Federal Safe Drinking Water Act (SDWA) MCLGs and
MCLs, 40 CFR 9 141.50 - 141.51 and 40 CFR 9 141.11 -
141.16.
B. Missouri Water Quality Standards for drinking water
supplies, Title 10 CSR 20-7.031.
2)
Federal Clean Air Act, 40 CFR 9 50-99 and the State
Implementation Plan, (SIP), and the Missouri Air
Quality Standards, 10 CSR 10.6.
Location Specific:
1)
2 )
40 CFR 9 264.18(b) of RCRA.
Section 662 of the Fish and Hildlife Coordination Act,
and the Endangered Species Act.
Action Specific:
1)
Substantive groundwater monitoring requirements of 10
CSR 25-7.264 (1)(F).
2 )
Substantive requirements of Underground Injection
Control requirements in 10 CSR 20-6.070, -6.090 and -
6.011.
3 )
Substantive and administrative requirements to be
followed for 40 CFR 9 403.5 and the POTW pretreatment
program.
39
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9)
10)
4 )
Missouri Well Construction Rules promulgated and
existing under the-authority of R.S. Mo. 9256.600-
256.640.
5)
6)
10 CSR 25-6, hazardous waste transporter license.
Land disposal restrictions, 10 CSR 25-7.268.
7)
CERCLA off-site policy, 40 CFR 9 300.440 of the NCP, 58
F.R. 49200 (9/26/93).
8)
Substantive requirements of 10 CSR 10.6; Air Quality
Standards, 40 CFR Parts 61 and 63 of the Clean Air Act
and the SIP; and 40 CFR Part 264, Subparts AA and BB.
10 CSR 25-7.264 (1) (B), sampling requirement.
10 CSR 20-6.200 (2) (B)3.A, storm water runoff control.
To Be Considered (TBC):
1)
EPA and the state of Missouri have agreed to follow
procedures that are not legally binding because they
are not promulgated. The EPA Office of Air Quality
Planning and Standards (OSWER) Directive 9355.0-28
specifies air emissions controls for VOC emissions
exceeding 10 tons/year for Superfund sites in non-
attainment zones which will be ~ollowed.
Applicable Non-Environmental Laws
1)
2 )
Substantive requirements of the local St. Louis county
and/or City of Valley Park zoning and building codes.
10 CSR 25 7-270 (2) (B) 6, engineering plans to be
approved by a registered professional engineer.
Cost-effectiveness:
Although this remedy is one of the most costly, but not the
most costly, it affords the most overall effectiveness
proportional to its'costs. As discussed in Section 8, the
selected remedy is the most protective of human health and the
environment through relatively quick remediation of both the soil
and ground water exposure pathways. In addition, it affords more
protection from exposure to contaminants than other alternatives
by addressing potential ambient air, subsurface conduit and air
sparging concerns.
40
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utilization of Permanent Solutions and Alternative Treatment
Technoloqies to the Maximum Extent Practicable:
The selected remedy utilizes permanent solutions and
treatment technologies to the maximum extent practicable. The
rationale for the selected remedy is as follows: the selected
remedy offers the most long term effectiveness and reduction of
toxicity, mobility and volume through treatment. Since this
remedy is an interim remedy and not a final remedy, the statutory
preference for remedies that employ treatment that reduces
toxicity, mobility, or volume as a principal element is partially
addressed in this remedy. The statutory preference for the
reduction of toxicity, mobility, or volume for the entire Valley
Park TCE Site will be addressed in the final remedial action.
The selected remedy is the only alternative, through SVE and
contaminant characterization, that may reduce migration of
contaminants along horizontal conduits. It is one of only two
alternatives that offers a reduction in volume sooner than other
alternatives through contaminated soil excavation and removal; it
is potentially more cost effective than the other relatively
accelerated remedial alternative.
Preference for Treatment:
The principal threats posed at this WOU are the threats
posed by exposure to VOCs (notably, PCE and TCE), metals and PAHs
by dermal contact and ingestion of contaminated soils and ground
water, and by inhalation of vapors from soil "and ground water
contamination. The treatment methods chosen address the risks
posed by ground water and soil contamination using treatment
methods including soil excavation and removal, ground water
extraction and monitoring, air stripping of extracted ground
water, and air sparging with SVE.
SECTION 11.0
DOCUMENTATION OF SIGNIFICANT CHANGES
There were no significant changes made to the Proposed Plan in
this Record of Decision.
41
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APPENDIX A
42
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GLOSSARY
EPA used the following nine criteria, as specified in the
National contingency. Plan C"NCP"), to evaluate alternatives
identified in the FS. While overall protection of public health
and the environment is the primary objective of the remedial
action, the remedial alternative(s) selected for the Valley Park
TCE Site must achieve the best balance among these evaluation
criteria considering the scope and relative degree of
contamination at the site.
1. Overall Protection of Human Health and the Environment in
order for an alternative to be considered, it must be evaluated
to determine if it adequately protects human health and the
environment, in both the short and long-term, from unacceptable
risks posed by hazardous substances, pollutants, or contaminants
present at the site by eliminating, reducing, or controlling
exposures to levels established during development of remediation
goals.
2. Compliance with Applicable or Relevant and Appropriate
Requirements (ARARs) -- in order for an alternative to be
considered, it must be assessed to determine if it attains ARARs
under Federal environmental law and State environmental or
facility citing laws or provide grounds for invoking a statutory
waiver pursuant to CFR 300.430(f) (1) (ii) (C).
3. Long-Term Effectiveness and Permanence -- each alternative
must be assessed to evaluate its ability to maintain reliable
protection of human health and the environment over time once the
cleanup goals have been met.
4. Reduction of Toxicity, Mobility, or volume -- These are the
three principal measures of the overall performance of an
alternative. The 1986 amendments to the Superfund statute
emphasize that, whenever possible, EPA should sel~ct a remedy
that uses a treatment process to permanently reduce the level of
toxicity of contaminants at the site~ the spread of contaminants
away from the source of contamination; and the volume or amount
of contamination at the site.
5. Short-Term Effectiveness -- each alternative must be
evaluated to assess the likelihood of adverse impacts on human
health or the environment that may be posed during the
construction and implementation of an alternative until the
cleanup goals are achieved.
6. Implementability -- each alternative must be evaluated to
determine whether it is feasible, technically and admin-
istratively. The availability of materials and service needed to
implement the alternative are a part of this assessment.
43
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7. Cost -- estimates are developed for the cost of implementing
an alternative, as well a's the cost of operating and maintaining
the alternative over the long term, and the net present worth of
both the capital and.operation and maintenance costs.
8. state Acceptance -- addresses whether, based on its review of
the RI/FS and Proposed Plan, the state concurs with, opposes, or
has no comments on the alternative EPA is proposing as the remedy
for the site. .
9'. community Acceptance -- addresses whether the public concurs
with EPA's Proposed Plan. Community acceptance will be evaluated
based on comments received at the upcoming public meeting and
during the public comment period.
Terms Used in the Record of Decision
Administrative Order (AO): A legal and enforceable agreement
signed between EPA and Potentially Responsible Parties (PRPs)
whereby the PRPs agree to perform or pay for the cost of site
response actions. The agreement describes actions to be taken at
a site.
Applicable or Relevant and Appropriate Requirements (ARARs):
ARARs include any state or Federal statute or regulation that
pertains to protection of public health and the environment in
addressing certain site conditions or using a particular cleanup
technology at a Superfund site. MDNR and EPA must consider
whether a remedial alternative meets ARARs as part of the process
for selecting a cleanup alternative for a Superfund site.
Aquifer: A layer of rock or soil that can
ties of ground water to wells and springs.
source of drinking water and provide water
well.
supply usable quanti-
Aquifers can be a
for other uses as
Carbon adsorption: A treatment system in which contaminants are
removed from ground water or surface water by forcing water
through tanks containing granular activated carbon, a specially
treated material that attracts and binds the contaminants.
comprehensive Environmental Response, compensation, and Liability
Act (CERCLA): A Federal law passed in 1980 and modified in 1986
by the Superfund Amendments and Reauthorization Act (SARA). The
acts created a special tax that goes into a Trust Fund, commonly
known as Superfund, to investigate and clean up abandoned or
uncontrolled hazardous waste sites. Under the program, EPA can
either: 1) pay for site cleanup when parties responsible for the
contamination cannot be located o~ are unwilling or unable to
perform the work: or, 2) take legal action to force,parties re-
sponsible for site contamination to clean up the site or pay back
44
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the Federal Government the cost of the cleanup.
contaminants of Concern (COCs): contaminants, identified during
the site investigations and risk assessments, that pose a
potential risk because of their toxicity and poten~ial routes of
exposure to public health and the environment.
Dense Non-Aqueous Phase Liquids (DNAPLs): A group of chemicals
which are denser than water and do not dissolve in water easily.
These chemicals include TCE and PCE and are common environmental
contaminants which tend to migrate downward through soil until'
encountering an impervious layer.
Downqradient: Downstream from the flow of ground water. The
term refers to ground water flow in the same way that it does to
a river's flow.
Safe Drinkinq Water standards: safe Drinking Water Standards
(SDWSs) for human ingestion specified in both the Federal Safe
Drinking Water Act (SDWA) and the Missouri Water Quality
Standards Title 10 CSR 20-7.031.
Ground water: Water, filling spaces between soil, sand, rock and
gravel particles beneath the earth's surface, that often serves
as a source of drinking water.
Maximum contaminant Levels CMCLs): The maximum permissible level
of a contaminant in water that is or "may be consumed as drinking
water. These levels are determined by EPA and are applicable to
all pUblic water supplies.
Migrate:
To move from one area to another; to change location.
Monitoring Wells: Special wells installed at specific locations
on or off a hazardous waste site where ground water can be sam-
pled at selected depths and studied to determine such things as
the direction in which the groundwater flows and the types and
concentrations of contaminants present.
National contingency Plan CNCP):
guides the Superfund program.
The Federal regulation that
Present Worth: The amount of money necessary to secure the
promise of future payment or series of payments at an assumed
interest rate.
operation and Maintenance (O&M): Act~vities conducted at a site
after response actions occur, to ensure that the cleanup or
containment system continues to be effective.
organic compounds: Chemical compounds composed primarily of
carbon and hydrogen, including materials such as oiis, pesti-
45
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cides, and solvents.
Parts per Billion (Ppb): A unit of measurement used to describe
levels of contamination. For example, one gallon of a solvent in
one billion gallons of water is equal to one part per billion.
Parts per Million (ppm): A unit of measurement used to describe
levels of contamination. For example, one-half pound of
contaminant in 250 tons of soil is equal to one part per million.
pOly-Aromatic Hydrocarbons: A group of semi-volatile organic"
chemicals commonly found as contaminants in soils.
Potentially Responsible Parties (PRPs): Any individual(s) or
company(s), (such as owners, operators, transporters, or genera-
tors) who are potentially responsible for the contamination
problems at a superfund site. Whenever possible, EPA requires
PRPs, through administrative and legal actions, to clean up a
hazardous waste site.
Resource Conservation and Recovery Act (RCRA): RCRA is a Federal
law that regulates the transportation, storage, treatment, and
disposal of hazardous wastes.
Remedial Alternatives: The technology, or combination of tech-
nologies, used by EPA in treating, containing, or controlling
contamination at a Superfund site.
Remedial Investigation/Feasibility study (RI/FS): A two-part
study that determines the nature and extent of the problem pre-
sented by the release and evaluates the options available for
remedial action. The Remedial Investigation (RI) emphasizes data
collection and site characterization and is typically performed
concurrently with the Feasibility study (FS). The FS emphasizes
data analysis in conjunction with technologies available for
consideration as remedial alternatives. -
sediments: The sand or mud found at the bottom and sides of
bodies of water such as creeks, rivers, streams, lakes, swamps,
and ponds. Sediments typically consist of relatively small soil
particles (such as silt, clay, or-sand) and organic (plant) mat-
ter. Gravel sized particles are sometimes included, as well.
semi-Volatile organic compounds: A group of organic chemicals
which have limited vOlatility. These chemicals are common
environmental contaminants which often have a high affinity for
soil.
Solvents: Liquids capable of dissolving other liquids or solids
to form a solution. The chief uses of industrial solvents are as
cleaners and degreasers. Solvents are also used in paints and
pharmaceuticals. Many solvents are flammable and toxic to vary-
46
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ing degrees.
Toxicity: A measure of the degree to which a substance is
harmful to human and animal life.
upgradient: This term refers to the direction of ground water
flow in the same way that the term upstream refers to a river's
flow.
VQCs: VOCs is an acronym for Volatile Organic Compounds. VOCs
are a class of organic chemicals which tend to evaporate at
normal atmospheric conditions. VOCs are typically man-made
chemicals and have become ubiquitous in our daily lives.
47
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RECORD OF DECISION
RESPONSIVENESS SUMMARY
VALLEY PARK TCE SITE
WAINWRIGHT OPERABLE UNIT
VALLEY PARK, MISSOURI
PREPARED BY:
MISSOURI DEPARTMENT OF NATURAL RESOURCES
DIVISION OF ENVIRONMENTAL QUALITY
JEFFERSON CITY, MISSOURI
ON BEHALF OF:
u.S. ENVIRONMENTAL PROTECTION AGENCY
REGION VII
KANSAS CITY, KANSAS
SEPTEMBER, 1994
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1.0
2.'0
3.0
RESPONSIVENESS SUMMARY
TABLE OF CONTENTS
OVERVIEW
PAGE
1
BACKGROUND ON COMMUNITY INVOLVEMENT
1
SUMMARY OF COMMENTS RECEIVED DURING THE
PUBLIC COMMENT PERIOD
3.1
3.2
2
COMMENTS FROM INTERESTED CITIZENS
2
COMMENTS FROM POTENTIALLY RESPONSIBLE
PARTIES
10
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~ESPONSIVENESS SUMMARY
VALLEY PARK TCE SITE - WAINWRIGHT OPERABLE UNIT
VALLEY PARK, MISSOURI
1.0 OVERVIEW
In the Proposed Plan, the Missouri Department of Natural
Resources (MDNR) in close association and with concurrence from
. the u.s. Environmental Protection Agency (EPA), made a
preliminary selection of the preferred remedial alternative. The
preferred remedial alternative addressed contaminated soil and
ground water at the Wainwright Operable Unit (WOU). The
treatment technologies included within the preferred alternative
were soil vapor extraction, air sparging, ground water extraction
and treatment, and limited excavation of surface soils
contaminated with Polynuclear Aromatic Hydrocarbons (PAH) and the
highest concentrations of Volatile Organic Compounds (VOC).
The comments received from interested citizens focused on the
slow pace of the cleanup of the site, problems with past actions
at the site, and payment of damages incurred as a result of the
contamination from Wainwright Industries, Inc. Judging from the
comments, the residents of Valley Park generally accepted the
preferred alternative.
The Potentially Responsible Party (PRP) for the WOU, Wainwright
Industries, Inc. (Wainwright), submitted two written comments.
The PRP disagrees with the characterizations in the Proposed Plan
that 1) the WOU is the sole source for the PCE and TCE ground
water contamination, and 2) there is an association between the
WOU and the ambient air contamination in the Cotton residence.
2.0
BACKGROUND ON COMMUNITY INVOLVEMENT
The Remedial Investigation/Feasibility study (RI/FS) and the
Proposed Plan for the WOU were released to the public on August
14, 1994. The Administrative Record file, which included the
RI/FS reports, the Proposed Plan and other relevant information
on the WOU, was made available to.the public at information
repositories maintained at the City of Valley Park Public
Library, the MDNR Hazardous Waste Program in Jefferson City,
Missouri, and the EPA Region VII Superfund Records Center, Kansas
city, Kansas. The notice of availability for these documents was
published in the st. Louis Suburban Journals on August 14, 1994.
A public comment period was held from August 14, 1994 through
September 12, 1994. A public meeting was held in Valley Park on
August 24, 1994. Interested citizens were notified about the
public meeting through the notice-in the st. Louis Suburban
1
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Journals and through letters sent to previously identified
interested individuals bY MDNR.
At the public meeting, representatives from MDNR, the Missouri
Department of Health; and EPA pr~sented information contained
within the Proposed Plan and answ~red questions about the WOU.
transcript of the public meeting is available in the
Administrative Record.
A
3".0 SUMMARY OF COMMENTS RECEIVED DURING THE PUBLIC COMMENT
PERIOD
Comments received during the public comment period are summarized
below. Responses to each comment are given immediately following
the comment.
3.1
COMMENTS FROM INTERESTED CITIZENS
Comment #1
One commenter asked what the health effects may have been from
ingesting contaminated ground water in the past?
Response
It is difficult to assess what the health effects from past
ingestion of contaminated drinking water may be. The amount of
time residents ingested contaminated water prior to discovery is
unknown. Drinking water contamination was discovered initially
in 1982. In 1982, the City of Valley Park began treating its'
drinking water with an aerator, which reduced contaminant
concentrations. In 1986, the city upgraded its water treatment
system to an air-stripper, which reduced concentrations to
acceptable levels. In 1988, Valley Park began receiving water
from St. Louis County, eliminating all exposure to VOC
contaminants from drinking water. As a result, the exposure to
contaminated drinking water potentially occurred from 1982 to
1988.
Ground water contamination levels increased significantly in the
fall of 1983. This'may indicate that the heart of the
contamination plume had not reached the city wells prior to this
date and that contamination prior to 1983 was relatively low.
Health effects of TCE and PCE are described in the Baseline Risk
Assessment, which can be found in the Administrative Record for
the WOU. Both contaminants are known or suspected carcinogens.
2
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Comment #2
One commenter asked if the Wilcox property (located adjacent and
northeast of the WOU) would be included in soil excavation and
stated that no soil samples had b8en collected on the property.
Response
Soil samples that have been collected between Wainwright and the
Wilcox property have been uncontaminated. It has been determined
in the Remedial Investigation that contamination does not extend
to the Wilcox property. Therefore, excavation at the Wilcox
property is unnecessary.
Comment #3
One commenter was concerned about barrels on the Wainwright
property that were there through the flood and have weeds growing
around them.
Response
The drums at the Wainwright property are filled with drill
cuttings from soil borings and monitoring well installation.
MDNR sent a letter on September 14, 1994 to Wainwright requesting
the disposal of the drums in an expedited time frame.
Contractors for wainwright have periodically cut weeds around the
drums and will continue to do so.
Comment #4
One commenter complained that the removal action was done
carelessly and that hazardous materials may have fallen out of
the sides of trucks and tracked around town. The commenter
continued to ask if past mistakes will be repeated in the future
remedial action?
Response
In future remedial actions at the WOU, officials from MDNR and/or
the EPA will be present to provide oversight. The MDNR and EPA
presence will ensure that hazardous substances will be contained
and that handling of hazardous substances will be done carefully.
The remedial actions presented in the Proposed Plan, will not
increase truck traffic and waste handling at the WOU to the
degree that occurred during the removal. The volume of soil
excavated during the remedial action will be minimal and the
other technologies require much less handling of hazardous
materials.
3
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Comment #5
The previous cornmenter stated that nearby residents were not
adequately informed .of the work conducted during the removal
'action.
Response
Prior to future remedial
will be notified by mail
the city council will be
Park Special Committee.
actions at the WOU, interested citizens
before the beginning of construction and
informed through the Wainwright/Valley
Comment #6
The previous commenter also inquired about the maximum depth of
soil contamination and stated that the removal action was closed
while contamination was present at a depth of 24 feet.
Response
Low levels of VOC contamination were detected during the Remedial
Investigation to a depth of 35 feet.
The removal action was stopped because the contamination was
'considered too extensive for excavation to remove effectively.
The soil vapor extraction system, which will be implemented
during the remedial action, in addition to ground water
extraction and air sparging should reduce contamination levels of
deep soils.
Comment #7
Two commenters asked if ground water contamination of the City of
Valley Park wells was caused by Wainwright?
Response
The Remedial Investigation indicated a clear link between TCE and
PCE contamination of soils at Wainwright and ground water
contamination. A previous investigation indicated that l,l,l-TCA
contamination probably originated from a source other than
Wainwright. At this time MDNR and EPA consider wainwright's past
activities have contaminated ground water with TCE and PCE.
However, there is another PRP responsible for the l,l/l-TCA
ground water contamination.
4
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Comment #8
Two commenters asked why a business is still allowed 'to operate
at the WOU with hazardous substances on the WOU and why residents
are allowed to live hear the contamination?
Response
The levels of contamination at the WOU are not high enough to
constitute an immediate threat to public health or an emergency.
There is not an acute risk. Health risks at the WOU are mainly
from long-term exposures to soils. Ingestion of contaminated
ground water would be the greatest health risk, but no one in
Valley Park is still using the contaminated aquifer for drinking
water or domestic uses. The areas with the highest levels of
contamination have been excavated and hauled away during the
removal action.
Since there is no environmental emergency at the WOU, EPA or MDNR
do not have the authority to evacuate residents or close the
business. Nor can EPA or MDNR impose zoning restrictions upon
businesses. Zoning of residential and business areas is the
province of local governments.
Comment #9
One commenter was concerned that the business operating on the
Wainwright property may still use solvents or operate in a
similar manner as wainwright.
Response
There has been no evidence of TCE or PCE use or any spills since
Wainwright left the property in 1979. The degreasers were
removed in 1979 when Wainwright moved.
Comment #10
One commenter wanted to know if the hazardous substances were not
acutely dangerous, why a warrant was placed for his arrest when
he tried to enter the property during the removal action?
Response
Wainwright sought the warrant on the particular individual.
Since EPA or MDNR did not take legal action to prevent anyone to
enter the property, it is difficult to speculate on the reasons
for the action. Access may have been controlled to prevent
people from exposure to the hazaids posed by a dee~, open pit as
5
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well as the hazardous substances on WOU, and to limit liability
of Wainwright if people-onsite fell into the pit.
Comment #11
One commenter asked what was the outcome of the survey of Valley
Park residents conducted by the Missouri Department of Health
(MDOH)?
Response
The study conducted by MDOH from February, 1992 through February,
1993 indicated there were no significant differences in cancer
rates or other health effects froIn Valley Park residents and the
outside population. .
Comment #12
One commenter asked what adverse health effects could be expected
for the people who worked at Wainwright for a period of 30 years
or more?
Response
It is difficult to assess health effects on a case by case basis
without knowing the details of the exposure. As a result, the
Superfund process typically does not quantify historic exposures.
However, in the Baseline Risk Assessment contained iri the
Remedial Investigation, an analysis was made of a scenario of an
on-site worker incidentally ingesting and directly contacting
soil, and inhaling volatilized compounds from soil for 25 years,
250 days per year. The assessment for this scenario indicated
there would be no unacceptable non-carcinogenic risk, but there
would be an increased cancer risk of 1.2 X 10'~ (1.2 in 10,000).
Please refer to the Summarv of Risks section of the Record of
Decision for an explanation of the increased cancer risk value.
This increased cancer risk is a conservative estimate based on a
longterm exposure and does not constitute an acute hazard
condition.
Comment #13
One commenter stated that after installation of the aeration
system on the Valley Park municipal wells, the achievement of
."acceptable limits" of contamination as determined by the
government were not trusted by the public. The commenter went on
to cite this as the reason for the city converting to the st.
Louis County water supply. The commenter then asked what is
being done to recoup the costs incurred by the city by converting
to the county water supply?
6
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Response
EPA and MDNR can and do seek to recover costs incurred through
investigating and remediating abandoned or uncontrolled Superfund
sites through the court system. EPA and MDNR do not have the
authority to recover costs incurred by local governments or
private individuals as a consequence of discharges at a Superfund
site. Local governments and private citizens have the same right
as EPA and MDNR to seek cost recovery from a potentially
responsible party through the court system.
Comment #14.
One commenter asked what recourse nearby residents have against
Wainwright for the aggravation of living next to a Superfund site
or having contamination on their property?
Response
Any individual interested in any private action should consult an
attorney.
Comment #15
One commenter asked if a neighboring resident could put up a
fence which has bee~ down pending action at the WOU? The concern
is that remedial action would begin soon and the fence would have
to be taken down soon after being put back up.
Response
Any action at the WOU which would involve disturbance at a
neighboring property would require restoration of that property
to its former state. The remedial action may be as much as two
years away from start up. Therefore, neighboring residents may
make any improvements to their property they see fit without fear
of interference from the remedial action.
Comment #16
One commenter asked what involvement the Missouri Attorney
General's Office had with the site?
Response
since the MDNR has the lead on the WOU, the Missouri Attorney
General's Office (AGO) is responsible for representing the State
of Missouri's legal interest in the WOU. The AGO is responsible
7
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for negotiating consent decrees and other legally binding
agreements with wainwriqht or other PRPs for the site.
The AGO does not represent individual citizens or political
subdivisions of the state (cities or counties).
Comment #17
A commenter asked what the legal steps are in deciding who would
fund the clean-up and whether the clean-up would proceed
regardless of who would fund the project?
Response
Following EPA signing the ROD, MDNR and/or EPA will enter into
negotiations with wainwright to conduct the selected remedy. The
negotiations may last as long as 120 days. The goal is for.
Wainwright to commit, in a legal document called a consent
decree~ to conduct the selected remedy. If Wainwright does not
sign the consent decree, EPA will initiate legal action to
attempt to force Wainwright to implement the selected remedy.
If these legal actions fail and Wainwright is still recalcitrant,
EPA will implement the selected remedy using federal funds.
After the selected remedy is implemented, legal proceedings will
again be initiated to recover the costs incurred by EPA in clean-
up of the WOU.
Comment #18
A commenter stated that the removal action was four years ago and
that no remedial work had been done at the WOU since then. The
commenter then asked if there was any way to expedite the
process? .
Response
At this point in the process, the pace of the project will be
determined by the degree of cooperation from Wainwright. If
Wainwright chooses to be uncooperative, then the necessary legal
proceedings or negotiations may significantly slow the pace of
the project. .
Comment #19
A commenter was concerned with the air sparging process and asked
how often sampling would be conducted in nearby buildings to
monitor the potential migration of VOC vapors into these
structures.
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Response
The exact frequency of air monitoring will be' determined during
the remedial design. There are air samplers available that are
continuous monitors which can run 24-hours a day.
There are other precautions that can be used during remediation
to prevent off-site migration ,of vapors. One method is to pull
many times the volume of air out with the soil vapor extraction
system than the volume of air pumped into the ground with the air
sparging system.
Comment #20
A commenter asked whether another public meeting will be held
when the remedial design is finished?
Response
There will not be another formal public meeting held. However,
there will be meetings with city officials through the
Wainwright/Valley Park Special Committee and nearby residents
will be kept informed by mail.
Comment #21
A commenter asked if there was a chance for representation or
participation from the general public in the negotiations with
Wainwright?
Response
The actual negotiations and legal agreement are closed
proceedings and not open to the public. However, if a consent'
decree is negotiated with wainwright, a pUblic comment period on
that agreement would be opened with an associated responsiveness
summary, prior to a court approving the agreement.
3.2
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COMMENTS FROM POTENTIALLY RESPONSIBLE PARTIES
Comment #1
The Proposed Plan implies that there is one source of PCE and TCE
contamination for Valley Park located in the vicinity of the
Wainwright property based upon conclusions from the Limited
Remedial Investigation. Wainwright disputes that implication,
based on well documented activities of other companies in Valley'
Park over several decades. The Proposed Plan deals only with the
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wou. Since additional investigations will be conducted for the
greater Valley Park TCE site, it is premature to conclude there
is a single source of PCE and TCE contamination in Valley Park.
Response
The Proposed Plan does not state that Wainwright is the only
source of PCE and TCE contamination in valley Park. There is
evidence of TCE and PCE contamination in various locations in the
general Valley Park area which have not been related to the WOU
at this time. However, the data from the Limited Remedial
Investigation and the Remedial Investigation conducted by
Wainwright's contractors does indicate contamination of the
Valley Park municipal wells comes from a single ground water
plume for PCE coinciding with a single plume of TCE contamination
which begins in the vicinity of Wainwright.
The cluster of wells located immediately downgradient of
Wainwright (17B & C) are the only wells where the shallow well is
more contaminated than the deep well. Since PCE and TCE tend to
sink to the bottom of an aquifer (move downward until a confining
layer or relatively impermeable zone is encountered), the higher
contamination of the shallower well indicates well cluster 17 is
very near the source. The contamination at this location has not
traveled far enough laterally to completely sink to the bottom of
the aquifer. Soil contamination at the WOU which extends into
areas of saturation is located less than 200 feet away from
monitoring wells 17B and C.. .
Upgradient wells and soil boring from the WOU indicated a marked
decline in concentration of contamination. This indicates no
other sources of contamination upgradient of Wainwright.
EPA and MDNR have investigated other PRPs in Valley Park and have
discovered no substantive evidence of other sources of PCE and
TCE contamination related to the contamination of the Valley Park
municipal wells. However, as stated in the comment from
Wainwright, this Proposed Plan focuses only on the soil and
ground water in the vicinity of the WOU. There is evidence that
another PRP contributed l,l,l-TCA contamination to the ground
water.
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comment #2
The Proposed Plan refers to an association between the WOU and
the Cotton residence, although it has not been established how
the PCE allegedly detected would have gotten into the Cotton
residence, nor has the origin of that PCE been established.
Response
The association between the WOU and the Cotton residence referred
to 'in the comment and the Proposed Plan involves VOC vapors
detected in the Cotton household. EPA contractors sampled the
air in the home, after the cotton's complained of odors coming up
through the plumbing. These odors began entering the house after
flood waters receded in the fall and winter of 1993 and into
January 1994. Air sampling revealed the presence of many of the
same contaminants found in the soils at Wainwright and which
extended into the soil of the cotton residence. The air
contaminant with the highest concentration was PCE.
After the initial air monitoring, traps were installed in the
plumbing of the house.' Air monitoring was conducted again and
indicated VOC vapor levels decreased in the household.
The air contamination at the Cotton residence is clearly
connected with the soil contamination at the WOU. PCE and TCE
are volatile chemicals. A' VOC contamination plume will often
consist of contaminated soil, contaminated ground water, and a
soil-vapor plume. The raising and lowering of the ground water
that occurs during and after a flood event will redistribute
contamination in the soil and will tend to force VOC vapors in
the soil upward to the surface and out from the location of
original distribution. The original soil contamination at the
Wainwright was discovered in the sewer lines. The sewer line and,
plumbing in the Cotton home are likely conduits for migration of
vapors. All of these factors, combined with the fact that air
sampling revealed many of the same contaminants present in soils
at Wainwright, indicate a clear link of the VOC air contamination
at the Cotton's residence with soil contamination at the WOU.
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