A)



UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION 7

11201 Rentier Boulevard
Lenexa„ Kansas 66219



MEMORANDUM

SUBJECT: Corrections to the Fourth Five-Year Review Report for the Syntex Facility Superfimd
Site dated September 28,2012

Former Syntex Agribusiness Inc. Facility - Verona Plant, MOD007452154

FROM:

THRU:

Steve Kemp, Remedial Project Manager (iJs* )
Special Emphasis Remedial Branch

Scott Pemberton ?
Regional Counsel^



TO:

Gene Gunn, Chief
Special Emphasis Remedial Branch

Cecilia Tapia, Director
Superfimd Division



30285470

Superfund

I.

PURPOSE

The purpose of this memorandum is to correct errors in the Fourth Five-Year Review Report For
Syntex Facility Superfund Site (4,h FYR) dated September 28, 2012. In general, the 4th FYR indicates
the remedy implemented at the former Syntex Facility in Verona, Missouri, for Operable Unit 1 (OU1)
was not consistent with the Record of Decision (ROD) for OU1l. The statement in the 4th FYR could be
interpreted to indicate the facility did not implement the remedy specified in the ROD. While it is true
that the implemented remedy was modified from the remedy specified in the ROD, it is important to
note the modifications were reviewed and approved by the EPA in several documents including the
Remedial Action Report (RAR)2, and the implemented remedy was protective of human health and the
environment at the time it was implemented.

There are several factors that may have contributed to the errors in the 4th FYR. First, the EPA's
SDMS system did not contain all of the documents relevant to the Site at the time of the 4th FYR, and
some of the documents that were in SDMS did not contain all of the appendices and attachments.

Second, it is not clear whether the author of the 4th FYR was provided with all of the necessary
background documents that were in SDMS. Third, the available documents are not clear and some
documents appear to contradict other documents. This memorandum describes the steps the EPA has
taken, and is continuing to take, to address these issues.

II. BACKGROUND

The former Syntex Agribusiness Inc. Facility (Site) is located immediately west of the
community of Verona, Missouri, in south central Lawrence County (Figure 1). Syntex Agribusiness Inc.

Printed on Recycled Paper


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purchased the facility from Hoffman-Taff in 1969. Hoffman-Taff manufactured 2,4,5-trichlorophenoxy-
acetic acid (2,4,5-T) for the US Army for the production of the defoliant commonly known as Agent
Orange. A portion of the Site was leased to NEPACCO for the manufacture of hexachlorophene. The
manufacture of both 2,4,5-T and hexachlorophene can produce 2,3,7,8-tetrachloro-dibenzo-p-dioxin
(dioxin) as a byproduct. The facility is the source of the dioxin that was sprayed on horse arenas, roads,
and parking areas by Bliss Waste Oil in the early 1970s.;The Site was the subject of numerous
investigations by state and federal agencies related to releases from the facility beginning as early as the
1960s. The EPA Region 7 Superfund Division began investigation of the Site in November 1980, and
the Site was listed on the NPL in September 1983.

The EPA designated two operable units at the Site. Operable Unit 1 (OU1) includes
contaminated soil and equipment. Operable Unit 2 (OU2) includes the groundwater. The EPA issued a
Record of Decision (ROD) for OU1 in May 1988 and for OU2 in May 1993. The remedial work for
OU1 was completed and the work was approved by the EPA in the RAR.

IH. INACCURATE STATEMENTS IN THE 4th FYR

i	•	I '

The ROD for OU1 required excavation of soils from three of the seven areas on the Site that

exhibited soil contamination. Based on analysis of soil samples collected at each of the three areas and
statistical detennination of thk 95 percent upper confidence level, soils exceeding 20 j^arts per billion
(ppb) were to be excavated. The Bum Area, the Irrigation Area, and the Lagoon Area were the areas
specified in the ROD for OU1 where soils were to be excavated.

The first paragraph on page ii of the FYR states,

"OU1 remedy implementation occurred in 1988; implementation, however, deviated from ROD

requirements. Three areas were identified to have the excavation/thermal treatment remedy

implemented; however, excavation /thermal treatment occurred at only one area (Lagoon Area)."

This statement is not entirely correct. While it is true the remedy, as implemented, deviated from
the ROD requirements, the deviation was the addition of a fourth area to be excavated, the Slough Area.
Three documents, the RAR, the Preliminary Closeout Report3 (PCOR), and the first Five Year Review
Report4 state that soil was excavated from four areas. "The four areas included the Burn area, the
Irrigation area, the Lagoon area, and the Slough area." It is not clear these three documents were
provided to the author(s) of the 4th FYR.	'

This issue is complicated by the fact that the Implementation Plan (IP)5 indicates that only the
Lagoon area was excavated. EPA records do not contain a document that corrects or supplements the
IP. Because the record is incomplete and unclear, the information presented in the RAR, PCOR, and
FYR was confirmed in a personal communication between Steve Sanders, EPA Counsel, and Steve
Kemp on January 29, 2014. During the communication, Mr. Sanders stated that he was aware that soil
was excavated from the Burn area and the Irrigation area because he had reviewed reports indicating
these activities occurred. Mr. Sanders stated there should be a report that clearly spells this out. The
EPA will continue efforts to locate missing documents to develop a complete record.

The second deviation from the remedy specified in the ROD was a change to the remedy
implemented in the Spill Area. In a letter dated September 5, 1995, Syntex proposed to leave the gravel
in place in the spill area and place an additional four to six inch stone layer over the gravel base with an

2


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asphalt or concrete cap over the gravel. The EPA approved the revised remedy in a letter to Syntex dated
October 6, 19956. The EPA provided the rationale for approving the modification in a memorandum to
the file7 and concludes that this type of cap will be more protective that a vegetative cap.

The 4th FYR indicates the'areas specified in the ROD that were to be vegetated were not
remediated properly, in part because the vegetative cover was not one foot thick. This is not correct. The
ROD does not specify the thickness of the backfill or vegetative layer for the Burn area, Spill Area, or
the Lagoon Area. Six inches of topsoil was specified for the Slough area, but as described above, the
remedy for the Slough area was modified with EPA approval in 1995.

The 4th FYR identifies "undefined areas of surface soil containing dioxin at concentrations
exceeding 1 ppb (at the 95% confidence level) for which the containment remedy may not have been
implemented." The EPA will be evaluating this statement, but based on the available information, the
statement does not appear to be correct. The ROD specifies: "For those soils containing less than 20 ppb
dioxin, the EPA hereby concludes, based on the criteria previously set forth that the in-place
containment of these soils, under vegetative covers is the preferred alternative." Vegetative cover did
not include a layer of topsoil. The RAR, the PCOR, and the first FYR state that vegetative cover was in
place in all areas.

Attachment 2 of the Remedial Action Report describes the inspection of the soil cap in the Burn,
Lagoon, Slough, Spill/Irrigation and Trench areas conducted on November 14, 1997. The inspection
states that the cap and vegetation at each of these areas was in good shape with good to excellent
vegetation. The ROD did not specify a cap for the Grid Area, only that the existing vegetation be
maintained. As stated above, the RAR serves to document EPA's approval of the remedy as
implemented.

IV.	PROTECTIVENESS OF THE IMPLEMENTED REMEDY IN LIGHT OF THE

REVISED Rfd FOR 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN

On February 17, 2012, the EPA released the final non-cancer dioxin reassessment, publishing a
non-cancer toxicity value, or reference dose (RfD), for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in
the EPA's Integrated Risk Information System (IRIS). This RfD is now the recommended value to be
considered (TBC) for use in developing site-specific dioxin PRGs and cleanup levels under CERCLA
and the NCP. For example, the PRG calculated using the new RfDpf 0.7 picograms per kilogram-day
(pg/kg-day)'and the EPA non-adjusted exposure factors would be 50 parts per trillion (ppt) toxicity
equivalence (TEQ) for residential soil and 664 ppt TEQ for commercial/industrial soil.

The EPA is currently evaluating whether the new Rfd will impact the assessment of the
protectiveness on the remedy implemented at the Site.

V.	ADDITIONAL MINOR CORRECTIONS

The 4th FYR indicates the Maximum Contaminant Level (MCL) for bis(2-ethylhexyl) phthalate
is 11 ppb. The correct MCL for bis(2-ethylhexyl) phthalate is 6 ppb. Bis(2-ethylhexyl) phthalate is one
of the synonyms for Di(2-ethylhexyl) phthalate (DEHP). The Technical fact sheet for DEHP indicates
the MCL for DEHP is 0.006 milligrams/liter (mg/L).

Page 3 of 6


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The current Drinking Water Equivalent Level established by the EPA for 1,4-dioxane is 1 mg/L.
The current EPA Screening Level for 1,4-dioxane in tap water is 0.67 micrograms/liter ((.ig/L).

VI. CONCLUSION

The 4th FYR report contains errors regarding the remedy implemented for OU1 at the Site. The
errors are attributable to several factors including the fact that the author(s) of the 4th FYR were not
provided with all of the necessary background documents.

The remedy implemented for OU1 at the Site was consistent with the ROD for OU1 and was
protective of human health and the environment at the time of implementation. Modifications to the
remedy were reviewed and approved by the EPA.

The Rfd for dioxin was revised in 2012. The EPA is .working with Syntex to evaluate whether
the remedy implemented at OU1 is still protective in light of the revised Rfd for dioxin.

The EPA has initiated steps to assure that all of the available and relevant historical documents i
are provided to the author(s) of future Five Year Review reports.

Page 4 of 6


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This drawing is neither a legally recofded map nor a survey and is
not intended to be used as one. This drawing is a compilation of
records, information and data used for reference purposes only.

FIGURE 1

FACILITY LOCATION MAP
SYNTEX FACILITY SUPERFUND SITE
VERONA, MISSOURI

Date: APRIL 2013

Revision:

Drawn By. ADM Checked By: RMK Scope: 12S239

08W2Q13- 1.00pm ndmi C:W9mMniU?»ktQpV123233_SyTriB3tfr»dWyl£eationI4v«g

Page 5 ol6


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References

No.# Document Description	SDMS Doc. ID

#

1	Record of Decision for Operable Unit 1 - Soils and equipment dated 40292398
May 5, 1988

2	Remedial Action Report (Revised) September 30, 1998	86758
Attachment 2 is a memorandum to the file date Nov. 14,1997

3	Preliminary Closeout Report dated September 16, 1998	86713

4	Five-Year Review Report dated September 1997	40034983

5	Implementation Plan volumes I and II dated July 29, 1988	40033549
! • Appendix 1 of the Implementation Plan is the Verification

Sampling Plan dated May 2, 1998.

• Attached to Verification Plaji is an article titled "A Sampling
Strategy for Remedial Action at Hazardous Waste Sites:

Clean-up of Soil Contaminated by Tetrachlorodibenzo-pi-
Dioxin". This article is also know as the "Exner Method".

6	Letter to Syntex approving the modification to the cap in the Spill	40024863
Area dated October 6, 1995

7	Memorandum to the file re: Modification in the Cap for the Spill	40039608
Area dated October 10, 1995

O

Page 6 of 6


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FOURTH FIVE-YEAR REVIEW REPORT FOR
SYNTEX FACILITY SUPERFUND SITE
Lawrence County, Missouri

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Executive Summary

This is the fourth Five-Year Review (FYR) of the Syntex Facility Superfund site located in
Verona, Missouri. The purpose of this'Five-Year Review is to review information to determine if
implemented remedies are and will continue to be protective of human health and the
environment. The triggering action for this FYR was the signing of the previous FYR on
September 27, 2007.

A significant development regarding remedy protectiveness was the finalization on February 17,
2012, of a noncaner chronic oral exposure reference dose (RfD) of 7xlO"10 mg/kg/day for
2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin hereafter). Utilizing this RfD and standard
Environmental Protection Agency risk equations and exposure factors, a level of 600 parts per
trillion (ppt) dioxin has been shown to be associated with a hazard quotient of 1 for
nonresidential exposure to dioxin-contaminated soil. Based upon this 600 ppt value, the remedy
may not be protective and additional information is needed to make a protectiveness
determination.

The Syntex Facility Superfund site is located west of the city of Verona, in south-central
Lawrence County in southwest Missouri. The facility occupies approximately 180 acres,
primarily along the east bank and within the floodplain of the Spring-River, which flows
northward through the length of the property.

Site contamination has resulted from management of waste streams generated from the
production of 2,4,5-trichlorophenoxy-acetic acid (Agent Orange), produced from May 1968
through February 1969, and from the production of hexachlorophene, produced from May 1970
to January 1972. Dioxin, a byproduct from the production of these products, was the main
contaminant addressed in soil; dioxin, 1,4-dioxane, hexachlorophene, heptachlor epoxide, 1,4-
dichlorobenzene, bis(2-ethylhexyl)phthalate, 1,2,4,5-tetrachlorobenzenenaphthalene, 1,2,4-
trichlorobenzene, 1,3-dichlorobenzene, antimony, and naphthalene are contaminants of concern
specifically addressed in groundwater. All areas of contamination, except one, are located within
the Spring River floodplain - the exception being a trench disposal area located on a bluff on the
west side of the Spring River. Areas of contamination include former lagoons, an abandoned
meander of the Spring River, a burn area, several areas where surface application of waste
streams occurred and disposal trenches located above the floodplain. Historic monitoring of
groundwater has detected sporadic hits of low concentrations of dioxin, volatile organic
compounds (VOCs), semi volatile organic compounds (SVOCs), and metals below levels of
health concern.

Soil contamination is addressed by the Record of Decision (ROD) signed May 1988 and is
identified as Operable Unit 1 (OU1). The OU1 ROD selected multiple remedies, each to be
applied to one or more specified areas of the facility. A nonresidential use soil dioxin action level
of 20 parts per billion (ppb) was established. Selected remedies were: excavation and thermal
treatment of soils contaminated with dioxin above 20 ppb; capping in-place with 12-inches of
clay and 12-inches of topsoil (Trench Area); in-place containment of soils under vegetative
covers (one-foot depth) for soils containing less than 20 ppb dioxin; and stabilization through
maintenance of the existing vegetation (specific to one area).


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Groundwater is addressed by the ROD signed May 7, 1993, and is identified as OU2. The OU2
ROD selected the "No Action with Continued Groundwater Monitoring" remedy as the preferred
alternative. This alternative specified a two-year duration of monitoring floodplain wells, after
which a risk assessment would be conducted to ensure that the no action approach remained
protective of human health and the environment. It does riot specifically address the groundwater
monitoring of the disposal trenches.

OU1 remedy implementation occurred in 1988; implementation, however, deviated from ROD
requirements. Three areas were identified to have the excavation/thermal treatment remedy
implemented; however, excavation/thermal treatment occurred at only one area (Lagoon Area).
Capping of the Trench Area is reported as having been implemented in accordance with ROD
requirements. The containment remedy application of the one foot of cover over areas having
surface soils with less than 20 ppb dioxin, is reported to have only been implemented at areas
where excavation occurred. This appears to have resulted in areas of uncovered ("uncontained")
surface soil containing dioxin between 1 and 20 ppb. The stabilization remedy was implemented
per ROD requirements; however, it appears that dioxin levels between 0.98 ppb and 3.10 ppb
may be "uncontained" at the surface at potentially 3.5 acres of the Site. Additionally, this review
identifies undefined areas of surface soil containing dioxin at concentrations exceeding 1 ppb (at
the 95 percent confidence level) for which the containment remedy may not have been'
implemented.

The OU2 remedy consisted of implementing the required two-year monitoring program from
November 1997 to August 1999. Results indicated the presence of VOCs in the alluvial aquifer,
including the alluvial-bedrock contact. A draft risk assessment (RA) was submitted by Syntex
after completion of the monitoring program; however, it has not been finalized. Syntex has
conducted voluntary sampling on an annual frequency of four select shallow alluvial floodplain
wells since August 2003. Results of the past 5 years (2007 - 2011) have included detections of
chlorobenzene (25 to 77 ppb); 1,4-dichlorobenzene (5.1 and 5.7 ppb); toluene (6.1 ppb); xylenes
(14 ppb); and bis (2-ethylhexyl)phthalate (11 ppb), all of which are less than drinking water
maximum contaminant levels (MCLs). Other constituents were detected, but reported at
concentrations less than quantitation limits and/or associated with blank contamination; these
include acetone (8.1 ppb J-coded and 31 ppb B-coded); methylene chloride (2.8 ppb JB-coded);
1,4-dioxane (35 to 94 ppb J-coded); ethylbenzene (0.33 to 1.4 ppb J-coded); toluene (0.65 to 3.1
ppb JB-coded; 0.28 to 0.9 ppb J-coded) and 1,3-dichlorobenzene (1.1 to 1.5 ppb J-coded). Dioxin
was not detected using reporting limits ranging from 0.64 to 12 picograms per liter during the
period 2006 to 2011.

Trench Area well monitoring has been conducted since 1991 under different programs and
frequencies. Since 2002, four wells have been sampled on an annual frequency. Monitoring data
from 1991 through 2006 shows that acetone was detected in the ppm range in two 1991 samples
at 3.9 and 4.9 ppm, while other VOCs were present at concentrations below their respective
MCL concentrations. Dichloromethane, however, was detected once in 1991 at 66 jig/L, which
exceeds its 5 ng/L MCL. Dioxin was reported in single samples collected in 2003 and 2004,
respectively at concentrations of 14 and 15 nanogram per liter (ng/L). Monitoring data for the
period from 2007 through 2011 identifies the following VOCs present above quantitation limits:
chlorobenzene (16 to 65 ppb), and 1,4-dichlorobenzene (5.6 ppb); and the SVOC bis(2-
ethylhexyl)phthalate also above its quantitation limit at 15 ppb. Additionally, the following
compounds were reported at concentrations less than their respective quantitation limits and

ii


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identified as estimated concentrations (J-coded): ethylbenzene (0.069 to 0.37 ppb); 1,4-
dichlorobenzene (0.19 to 3.8 ppb); toluene (0.24 to 0.66 ppb); bis(2-ethylhexyl)phthalate (4.5
ppb) and dioxin (5.8 to an estimated maximum of 18 pg/L). Groundwater contamination at the
Trench Area has been encountered at both the weathered bedrock - bedrock contact and near the
bedrock - and the shale contact.

The voluntary monitoring program has been found deficient in that the analytical method used
for 1,4-dioxane yields inappropriate quantitation levels (400 ppb); and, only the upper 15-feet of
the alluvial aquifer has been monitored when past sampling has detected VOCs at the alluvial-
bedrock contact. Trench Area monitoring has identified contamination sporadically present at
wide-ranging depths. This review recognizes the complex hydrogeologic setting of the Trench
Area and recommends that the Trench Area monitoring network be re-evaluated with respect to
its ability to adequately monitor potential releases from the Trench Area.


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Five-Year Review Summary Form

SITE IDENTIFICATION

Site Name: Syntex Facility Superfund Site

EPA ID:

MOD007452154

Region: 7

State: MO

City/County: Verona/Lawrence

iv


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Five-Year Review Summary Form (continued)



None OU i and OU2 have isstws.



OU1 - Soil

Issue Category: Remedy Performance

issue: Utilizing the newly established RfD and standard norwv^'Vnt.al u^c* the

EPA risk equations and exposure factors, a level of 800 parts par tni'.on (ppt)
dioxin is shown to be associated with a hazard quotient of 1 for nontvwrif ntwi
exposure to clioxin contaminated soil.

Recommendation: Characterize current dioxin soil contamination and conduct
a human health risk uiiw;r.sfwnt ut^/iuci the boat available iluta

Affect Current
Protectiveness

Affect Future
Protectlveness

Implementing
Party

Oversight Party

Milestone Date

Yes

Yes

PRP

EPA/State

9/20/14



OUt - Soli

Issue Category: Remedy Performance

Issue; Implemented remedy did not address subsurface soil > 20 ppb dioxin.

Recommendation: Evaluate risk posed by such soil

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing

Party

Oversight Party

Milestone Date

No

Yes

PRP

EPA/State

9/20/14

Issues and Recommendations Identified In the Five-Yea? Review; #;i

OU1 - Soil

a Category; Remedy Perfor

Issue: "Containment" remedy is reported to have been implemented only at
excavated areas {which were backfilled/capped with clean soil), resulting in both
defined and undefined areas of "non-contained" surface soil with dioxin exceeding
600 ppt.

Recommendation: Characterize current site conditions. Evaluate risks to current
and potential future receptors. Determine whether additional remedial actions are
necessary.

Affect Current
Protectiveness

Affect Future

Protectiveness

Implementing

Party

Oversight Party

Milestone Date

Yes

Yes

PRP

EPA/State

9/20/14

v


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Five-Year Review Summary Form (continued)



OU1 - Soil

Issue Category; Remedy Pvformanc*

Issue: "Based on historical data collected from the site, approximately 3.5 acres
of surface soil may contain levels of elioxin that exceed the EPA's industrial soil
screening level based on the new elioxin toxicity value.

Recommendation: Characterize current site conditions. Evaluate risks to current

and potential future receptors. Determine whether additional remedial action:; aro
necessary.

Affect Current ,
Protectiveness

Affect Future
Protectiveness

Implementing

Party

Oversight Party

Milestone Date

Yes

Yes

PRP

EPA/Slate

9/20/14

: issues and Recom

obi -~s©ii~

mendations Identified in the five-Year Review: #5
Issue Category: Monitor

Issue; The complexity of the hydrogeologic setting of the Trench Area suggests
that potential releases may not be intercepted by existing well network.

Recommendation: evaluate existing well network and modify as appropriate.

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing

Party

Oversight Party

Milestone Date

Yes

Yes

jpP^P

EPA/State

9/20/14



OU1 - Soil

Issue Category: Remedy S-eHorr-ws

Issue: Secondary structural features of the residuum may result in unacceptable
high rates of potential contaminant transport in the Trench Area.

Recommendation: Re-evaluate physical properties of the in-situ residuum
underlying the Trench Area with respect to its ability to inhibit/prevent contaminant

constituent migration into the environment. Re-evaluate decision to contain/cap
Trench Area.

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing

Party

Oversight Party

Milestone Date

No

Yes

PRP

EPA/State

9/20/14

vi


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Qui & 2 - Soli &
Groundwater

Issue Category; Remedy Performance

Issue; An ecological risk assessment has not been performed.

Recommendation: Conduct an ecological risk assessment using best available
data and newly acquired data as needed,

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing

Party

Oversight Party

Milestone Date

Yes

Vt-s

PRP

EPA/State

9/20/14

issues and Recomn1""'1"'^"""- ,ri"-*:,icti in the Ftvc-Vesr Review #8

OU2 -

Groundwater

2 Catcgojy: Moult©!

Issue: 1,4-dioxane has not been analyzed with an analytical method having
quantitation levels that would support n risk assessment.

Recommendation: Revise groundwater sampling and analysis plat- to idontity an
appropriate analytical method yielding quantitation levels sufficient to support a
risk assessment.

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing
Party

Oversight Party

Milestone Date

Yes

Yr>*\

PRP

EPA/State

9/20/14

issues and Recommendations identified in the Five-Yesr Review: #3

OU2 -

issue Category: Monitoring





Groundwater

Issue: Monitoring of the deep alluvial screened intervals has not occurred in the
past 10 years.



Recommendation: Begin monitoring the alluvial-bedrock contact and/or bedrock
prior to assessing current site risk associated with groundwater.

Affect Current

Protectiveness

Affect Future
Protectiveness

Implementing

Party

Oversight Party

Milestone Date

Yes



PRP

EPA/Slate

9/20/14

vii


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I

Operable Unit:	Pmimtlwmess Determination:	Addendum Due Date

OU1 - Soils	Protectiveness Deferred	(If applicable):

September 30, 2015

Protectiveness Statement:

A protectiveness determination for the remedy at GUI cannot be made iintil further information is obtained. The
soil level associated with a hazard quotient of 1 for a commercial/industrial worker using the new Rffl of 7E-10
mg/kg/day is 600 ppt. Surface soils indicated to contain dioxin at greater than 1 ppb may not have been
"contained" in accordance with the selected remedy as a) records show verification sampling of surface soils
containing dioxin between 1 and 20 ppb at the 95 percent confidence level which may not have been
"contained"; b) the lateral extent of soils detnonst.ra.teci by verification sampling to contain dioxin at.
concentrations greater than 1 tmb was not defined; and, ej implementation of the "stabilization" remedy has
poti-iUi.ilh ,!l!sf\u-il an eotnnt< J * -> ;k res of surface soil characterized as containing clioxin at concentrations
rn'.iUi tli,in 1 pph to K'iti.im '	It has, however, been 15-20 years since these dioxin data were taken.

Dunn? that time it is possible that there have been "substantia! rtK»n?f« in soil concentrations that may affect the
rx.itsi.ittoii ol it-Is*. •Vttiaf o'spv-uu• at tlv >-ite .tie ««>t l.nnwn ,»**»! n»vU to he t.ikeii tutu .tccount to arrive at an
a|ipni\iiii,it(nii of risk .os.t.oaictl v.tih  n/e etwie«« ilu<\m »•«>«% ctittjttw* am! }vi lortiianee of a baseline
tisk (ivH^Mnent using anient esposun' «m»l t.«\teny t'» tots 11\. (nokvtnrt.i .<1 tho temedy for ecological risks
nn tlis- site i ann.w he m.nic ;i! this nine um.I fnuliei ini>M«i».ittiiieJ itifoitn.tuoii wil! include sampling to
(,lwitieieii/.e euiieiit contaminant* u»i the sue i niiMite oi'« Iktoeliuc Leolugival Misk Assessment using
current guidance.

Operable Unit:	Protectiveness Determination:	Addendum Due Date

OU1 - Soils -Trench Protectiveness Deferred	(if applicable):

Area	September 30, 2015

Protectiveness Statement:

The protectiveness of the implemented OUl Trench Area remedy cannot be made at this time until further
information is obtained regarding the groundwater monitoring program, further information will be obtained by
taking the following actions; conduct 1,4-dtoxane analysis with analyte specific methodology; and, conduct a
comprehensive Revaluation of the Trench Area well network in order to verify that groundwater gradients can be
established and that screened intervals are correctly located with respect to intercepting potential Trench Area
releases (found deficiencies would need, to be corrected). These actions would provide a monitoring program
ni.ne lileK lo tnten epi	releases from the Trench Area.

viii


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Protectiveness Statement(s)

1 1

Operable Unit:
OU2 - Groundwater

Protectiveness Determination:
Protectiveness Deferred

Addendum Due Date
(if applicable):

September 30, 2015

Protectiveness Statement:

A protectiveness determination of the remedy at OU2 cannot be made at this time until further information is
obtained. Further information will be obtained by taking the following actions: initiating groundwater sampling
from a monitoring network that encompasses more than the uppermost 15-feet of alluvial aquifer; utilizing an
appropriate analytical method for 1,4-dioxane; and conducting a risk assessment utilizing data of a quality
sufficient to support a risk assessment. A revised protectiveness statement is anticipated to be made via an
addendum by September 30, 2015, if the recommendations are implemented with sufficient time to allow the
collection of a minimum of 6 quarters of groundwater data.

Sitewide Protectiveness Statement (if applicable)

Protectiveness Determination:	Addendum Due Date (if applicable):

Protectiveness Deferred	September 30, 2015

Protectiveness Statement:

Overall, the protectiveness of the implemented remedies cannot be determined until further information is
obtained. Much of the data on this site is either over fifteen years old or missing and may therefore not be
representative of current concentrations. The new RfD for 2,3,7,8-TCDD indicates that a protective level for site
workers may be as low as 600 ppt. Groundwater cancer risks cannot be properly evaluated with existing data
because the quantitation limits on the analyses performed for l ,4-dioxane are now too high due to an increase in
the cancer potency of 1,4-dioxane. Toxicity factors for a number of other analytes may also have changed since
the last risk assessments. Finally, no assessments of ecological risks appear to have been made at this site.
Further information will be obtained by taking the following actions: resampling areas potentially affected by
dioxin in soil, conducting an ecological risk assessment, conducting 1,4-dioxane analysis by newer methods with
appropriate quantitation limits in the trench area and groundwater, reevaluating the trench area well network,
and conducting an updated human health risk assessment for groundwater and soils. A revised protectiveness
statement is anticipated to be made via an addendum by September 30, 2015.

ix


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Table of Contents

Executive Summary			i

Five-Year Review Summary Form				iv

List of Abbreviations	;			xiv

I.	Introduction			1

II.	Site Chronology					3

III.	Background	7

3.1.	Physical Characteristics	Error! Bookmark not defined.

3.2.	Hydrology	Error! Bookmark not defined.

3.3.	Land and Resource Use		8

3.4.	History of Contamination	.'.			8

3.5.	3.5 Initial Response 		..11

3.6.	Basis for Taking Action.				23

4.	4.0 Remedial Actions				25

4.1.	Remedy Selection		Error! Bookmark not defined.

4.2.	Remedy Implementation	;	27

4.3.	Operation and Maintenance (O&M)		32

5.	Progress Since the Last Five-Year Review	:	32

5.1.	Previous Five-Year Review Protectiveness Statement and Issues	32

5.2.	Work Completed at the Site During the Review Period	34

6.	Five-Year Review Process	:		34

6.1.	Administrative Components		34

6.2.	Community Involvement			35

6.3.	Document Review	.".	35

6.4.	Data Review		37

6.5.	Site Inspection					46

6.6.	Interviews	 	48

6.7.	Institutional Controls	49

7.	Technical Assessment			50

7.1.	Question A: Is the remedy functioning as intended by the decision documents?	...50

7.2.	Question B: Are the exposure assumptions, Toxicity Data, Cleanup Levels, and Remedial
Action Objectives (RAOs) Used at the Time of Remedy Selection Still Valid?	51

7.3.	Question C: Has Any Other Information Come to Light That Could Call Into Question the
Protectiveness of the Remedy?				54

xi


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7.4. Technical Assessment Summary			"	55

8.	Issues				!	56

9.	Recommendations and Follow-up Actions	58

10.	Protectiveness Statements						59

11.	Next Review	61'

List of Figures

o

Figure 1. Site Location

Figure 2. Remediation Areas and Well Locations

List of Tables

Table 1. Chronology of Site Events				.3

Table2. Disposal Trench Usage			10

Table 3. Summary of Maximum Concentrations of Non-Dioxin Contaminants	12

Table 4. Maximum Concentrations of Tentatively Identified Compounds in Groundwater	13

Table 5. Burn Area: 1982 Sampling Results	)	14

Table 6. Burn Area Quadrant No. 180: 1985 Sampling Results	15

Table 7. Irrigation Area 1982 Sampling Results	15

Table 8. Irrigation Area 1985 Sample Results	16

Table 9. Spill Area 1985 Sampling Results		17

Table 10. Lagoon Area 1982 Composite Sampling	17

Table 11. Slough Area 1985 Composite Sample Results....		19

Table 12. Grid Area TCDD Composite Sample Results (detections)	20

Table 13. Groundwater Analytes of 1987 - 1989			21

Table 14. Lagoon Area Verification Sample Results	30

Table 15. Summary of ARAR Changes				37

Table 16. Grid Area TCDD Composite Sample Results (detections)	38

Table 17. IC Summary Table		50

Table 18. Current Issues with the Verona Syntex Site	i	57

Table 19. Recommendations to Address Current Issues at the Syntex Verona Site	57

xii


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List of Appendices

Appendix A
Appendix B
Appendix C
Appendix D
Appendix E

List of Documents Reviewed
OU1 Textural References
OU2 Textural References
Press Notices
Interview Forms

xiii


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List of Abbreviations

ARARs	Applicable or Relevant and Appropriate Requirements

ATSDR	Agency for Toxics Substances and Disease Registry

bgs	Below ground surface

CD	Consent Decree

CERCLA	Comprehensive environmental Response, Compensation, and Liability Act

CFR	Code of Federal Regulations

cfs	Cubic Feet per Second

COD	Chemical Oxygen Demand

' EPA	Environmental Protection Agency

FSSP	Fish and Sediment Sampling Plan

hex	Hexachlorophene

lbs	Pounds

LD-50	Lethal Dose

MCL	Maximum Contaminant Level

MDHSS	Missouri Department of Health and Senior Services

MDNR	Missouri Department of Natural Resources

ng/L	Nanograms per liter

NCP	National Contingency Plan

ND	Non Detect

NEPACCO	Northeastern Pharmaceutical and Chemical Company

NPL	National Priorities List

NRC	National Research Council

O&M	Operation and Maintenance

OSWER	Office of Solid Waste and Emergency Response

OU	Operable Unit

PAH	Polycyclic aromatic hydrocaron

ppb	parts per billion

ppm	parts per million	-

ppt	parts per trillion

ppq	parts per quadrillion

PRG	Preliminary Remediation Goals

RA	Remedial Action

RAGS	Risk Assessment Guidance for Superfund

RAO	Remedial Action Objective

RCRA	Resource Conservation and Recovery Act

RD	Remedial Design

RD/RA	Remedial Design/Remedial Action

ROD	Record of Decision

RPM	Remedial Project Manager

RSL	Regional Screening Level

xiv


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List of Abbreviations (continuation)

SAP	Sampling and Analysis Plan

SVOCs	Semi-volatile organic compounds

TBC	To be considered

TCDD	2,3,7,8-tetrachlorodibenzo-p (dioxin)

TCP	Trichlorophenol

TCB	Tetrachlorobenzene

USACE	U.S. Army Corps of Engineers, Kansas City District

VOC	Volatile Organic Compound

2,4,5-T	Trichlorophenoxy-acetic acid

(ig/kg	microgram per kilogram

|ag/L	microgram per liter

V

XV


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xvi


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I. Introduction

The purpose of a five-year review (FYR) is to evaluate the implementation and performance of a
remedy in order to determine if the remedy is and will continue to be protective of human health
and the environment. The methods, findings, and conclusions of FYRs are documented in fiver
year review reports. In addition, FYR reports identify any issues found during the review,' and
document recommendations to address them.

The U.S. Environmental Protection Agency (EPA) prepares FYRs pursuant to the
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Section
121 and the National Contingency Plan (NCP). CERCLA 121 states:

If the President selects a remedial action that results in any hazardous substances,
pollutants, or contaminants remaining at the site, the President shall review such remedial
action no less often than each five years after the initiation of such remedial action to
assure that human health and the environment are being protected by the remedial action
being implemented. In addition, if upon such review it is the judgment of the President
that action is appropriate at such site in accordance with section [104] or [106], the
President shall take or require such action. The President shall report to the Congress a
list of facilities for which such review is required, the results of all such reviews, and any
actions taken as a result of such reviews.

The EPA interpreted this requirement further in the NCP; 40 Code of Federal Regulations (CFR)
Section 300.430(f)(4)(ii), which states:

If a remedial action is selected that results in hazardous substances, pollutants, or
contaminants remaining at the site above levels that allow for unlimited use and
unrestricted exposure, the lead agency shall review such actions no less often than every
five years after the initiation of the selected remedial action.

The EPA Region 7 conducted a FYR of the remedial actions implemented at the Syntex
Superfund Site in Verona, Lawrence County, Missouri. The EPA is the lead agency for
developing and implementing the remedy for the Site.

This is the fourth FYR for the Syntex Superfund Site. The triggering action for this statutory
review is the September 27, 2007, signature date for the third FYR . The FYR is required due to
the fact that hazardous substances, pollutants or contaminants remain at the site above levels that
allow for unlimited use and unrestricted exposure. The Site consists of two Operable Units, both
of which are addressed in this FYR. -

1


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II. Site Chronology

The full »»w int* tabic Ihk the dak's of important events for the Syntax Verona Superfimd Site,

| Hoffman4aff ends j	.>ntn;v po-.tu i.k-

i	Pliarmaccutical and Oicuiicji Ltciipjm

t	1

[ (i\I• I" \( X '( >) U a si n 'Vi'Ciii i >i ,11 nv jiiOihklii • :» Inn'

i

NI*'i'A('('< > cini:pk'ic> I(iM bakbt'l Ik'Kaehioiopheik1	j

I cilci futm 11 T to MtvisHiti W'nk'i Polluii.tn Hi>a1.1'my Nkp-, in I
eliminate svcpjyv and ><\ci ll-.>\s Iiuih i a'b>i>n-,, ,sK«»	^ '

! NiTACl<>"s w.iMc	|

XI 1V\(> 1-iiv

* ,m i o 11

MO t h\ i>l (ie and hku'k Unix louiiu' m i>|Kii
ditch oimm.ittn^ from M,n 1!, jnc

3/26/71

Trench Area is "smoothed" mui (dosed)

11/6-13/71

t JSC is dye irace study

1971

NTPA< 'i '«> makes lass batch •>! hevicldomphein.'

1 10'??

NEPACCO liquidates assets

5/05/74

Still boi units lappro\iifiaifl\ 43^' uallons) di «.'m eicd m pi tni

8/74

I I * A samples Spring River watei, sediment, and Itsii

1M7K

("unseis! Deuce disposal lU'iKli

1980

Prchmtnatx Assessment pcitoinsed

1 1'Kf!

Site Investigation performed

11/81

Consent Order - momtotmp. testinp analws and t epoetins

K<06 K2

1 (.')

11/18/69

5/15/70

2/09/71

3


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Jllltiili



^ onsem Agi ' ! , or I'm oImmo'-"- • nal'ne anil
cMcnl; fish : *>htis' p'an l<> . • - I V-yis R*.; i k-. tsal

Allien (KI)

9 On S 1

NI'I listittu 11 m.tl i



Remedial ImoMirai ion/Feasibility Study complete (OUI)

Proposed l'!;m available for puHic comment (OU1)
R< )11 si^natUR1 ((

UiH\

5 1 ! s ,w

Exc.i\«»»it»n Plan approval by the EPA

							................ 											

1 cilci Xmvtnetii ix'iwuosi the 1 I* \ :<:>d SynUw auihni/m;'
excavalson. (ninspoi l. and ineiiiciaiiun

l"\cn\.iiiU2)

8/09/92

Proposal Plan available les public comment (<¦ H \"'l

S ¦ I 1 *0

Record oi Decision signed << U A)

Closure ol'Spdl \tea the I-PA appio\cs asp'wll oi iniknic tap

in lieu ut'lhc \ci>,ct:tn\c c6

IK B contaminated soil ds\co<,crcd

4/97

AdmimsUativ c (»rdci on ('onsen! Pi B removal and groundwater
sampling

7/18/97

PCB Removal Action complete

9/29/9?

1 irst 1 nv-Yeai Ke\lew Report

9/10/0?

I'mai Inspection ((it'S i

! <>s

4


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1'1'A Remedial Action Report
Second |-i\c-Year Rt'\ic\v i'ep,>fi
I Inixl 1 i\i'-Ycai Rev tow Rcp.'ti

9/25/91

	

5


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6


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III. Background
Physical Characteristics

The Syntex Superfund Si te is located west of the city of Verona, in south-central Lawrence
County in southwest Missouri. The facility address is 299 Extension Street, Verona, MO 65769-
0085. The facility occupies approximately 180 acres, primarily along the east bank and in the
flood plain of the Spring River, which flows northward through the length of the property
(Figure 1).

The Syntex property is adjacent to land on the north, west, and south sides which is used for
agricultural purposes. The east side of the property is adjacent to the city of Verona, which has a
2010 census population of 714 (http://censusviewer.com/city/MO/Verona). Syntex is located on
the Spring River flood plain, except for one "sub-site" (Trench Area) located upon a bluff
overlooking the floodplain. As a result, the site east of Spring River is very flat.

Hydrology

The site is in the upper Spring River watershed, which drains an area of approximately 25 square
miles upgradient to the site. The segment of the Spring River that flows through the site averages
a flow of approximately 10 cubic feet per second (cfs). Due to the presence of springs in the
watershed above the site, flow is perennial, although very low flow rates are possible during
extreme drought. Periods of intense and/or prolonged precipitation in the area can result in
temporary flooding in the area of the site, although the facility is reported to have engineering
structures in place to limit the affect of flooding on plant operations (Barks et al., 1983).

Stream flow is directed to the north at the Syntex property. The headwater of the Spring River is
an estimated-3-miles upstream from the site and drains approximately 25-square miles. The total
Spring River Watershed encompasses an area approximately 2,271 square miles and is located in
southwest Missouri in Barry, Barton, Christian, Dade, Jasper, Lawrence, Newton and Stone
Counties.	, .

The Spring River exits Missouri and passes through southeastern Kansas where it is collected by
the Grand Lake O' The Cherokees in Oklahoma. The basin lies along the border between the
Osage Plains and Springfield Plateau physiographic regions. Major Tributaries within the
watershed are the North Fork of the Spring River, Center Creek, Turkey Creek and Shoal Creek.
Numerous smaller tributaries flow throughout the watershed.

Hydrogeology

The facility overlies alluvia) deposits which rest uncomfortably upon an. eroded carbonate
bedrock surface. The alluvium consists of fine to coarse-grained clastic sediment ranging from
10 to 30 feet in thickness. The alluvial deposits are underlain by carbonate bedrock which
consists of fractured cherty limestone. The Northview Shale, underlying the carbonate bedrock,
acts as a confining bed for vertical groundwater movement in this area. The thickness of the
shallow bedrock is controlled largely by position of its erosional surface, and is approximately

7


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90-ft in thickness below the facility. There is no confining layer between the alluvium and the
shallow bedrock, which indicate that these two units act as a single aquifer (EPA, 1993).

Regarding the upland area where trench disposal operations had been conducted (west side of
Spring River), the following description obtained from the Missouri Department of Natural
Resources (MDNR) Geological Survey and Resource Assessment Division, may be applicable:

Surficial material on the slightly to moderately rolling upland terrain is a residuum
developed from the weathering of limestone and some sandstone bedrock; that derived
from limestone bedrock ranges from stone-free red clay to a cherty red clay. Chert
fragments are the major constituent in some areas. Characteristically, the red clay is not
dense unless chert fragments are abundant. Clay structure is angular and blocky, and the
clay is somewhat plastic. Permeability, as determined in the laboratory, ranged from 2.8
x 10-4 to 2.8 x 10-5 ft/day. Onsite permeability is assumed to be much greater,
however, because discrete flow can occur along the more cherty zones in the soil as
well as along the faces of the soil peds of the red clay (Barks et al., 1983).

Historical static water-level measurements from alluvial monitoring wells were used to
determine the potentiometric surface of the shallow unconfined aquifer. The data collected
indicates that ground water flow in the alluvial aquifer moves in a north-northwesterly direction
at the site. The direction of groundwater flow may be influenced by the presence of a buried
channel which parallels the Spring River at the site (EPA, 1993).

Land and Resource Use

Prior to the current industrial use of the site, the floodplain was utilized for agricultural and
recreational purposes. The western part of the site where the Trench Area is located is too steep
for most beneficial uses. Projected land use is not expected to change in the foreseeable future.
Current land use for the area surrounding the site is primarily agricultural except for the town of
Verona to the east of the site. These uses of surrounding land are not expected to change in the
foreseeable future.

Ground water is exploited from both shallow and deep aquifers in the area. The shallow aquifer
is available for use by rural households for domestic purposes and in some cases for agriculture,
but it is vulnerable to contamination. The EPA, prior to signing the OU2 ROD, identified and
sampled three residential wells within approximately one mile downstream (no contamination
found). The deep aquifer is generally utilized by water utilities and large-scale agricultural
operations due to its higher production capability and lower risk of contamination. There are no
known restrictions on ground water use in the area.

History of Contamination

In the 1960s, Hofftnan-Taff, Inc. owned and operated the facility. Hoffman-Taff produced 2,4,5
Trichlorophenoxy-acetic acid (2,4,5-T) for the U.S. Army as part of the production of the
defoliant commonly referred to as Agent Orange. In 1969, Hoffman-Taff leased a portion of the
facility to Northeastern Pharmaceutical and Chemical Company (NEPACCO) for the production
of hexachlorophene. Production of hexachlorophene is reported to have occurred from 1970 to

8


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1971 (ROD Declaration). In 1969, Syntex purchased the facility from Hoffinan-Taff and allowed
NEPACCO's lease to remain in effect.

Production of 2,4,5-T and hexachlorophene generate the intermediary byproducts of 2,4,5-
Trichlorophenol (TCP) and 2,3,7,8 tetrachlorodibenzo-p-dioxin (dioxin). In the course of
purifying the hexachlorophene, still bottom wastes were created with concentrated levels of TCP
and dioxin^ These waste streams were initially managed in storage tanks and lagoons onsite. Off-
site management of these waste streams occurred beginning in 1970 when NEPACCO initiated
shipping still bottoms for incineration and in early 1971 when 3,000 gallons of still bottoms were
taken off-site by a waste hauler (EPA, 1982).

The first reports of environmental contamination originating from the Syntex facility pertain to
alleged contamination of the Spring River and concern that downgradient springs might be
affected by seepage from the lagoons present at the facility. A letter from a local citizen, dated
September 28,1961, raises concerns about pollution of the Spring River (EPA, 1982).

The site was placed on the proposed National Priorities List (NPL) on December 30, 1982
(Federal Register Volume 47, Number 251). On September 8, 1983, the NPL designation
became final (Federal Register Volume 48, Number 175). The principal threats posed by the site
were human and animal direct contact (ingestion, inhalation and dermal) with dioxin
contaminated soil and wastes. The dioxin contaminated soils, liquids, and sludges were also a
potential source for groundwater and surface water contamination.

Seven areas (subsites) have been investigated for soil dioxin. These areas are depicted on Figure
2, and are described as follows (EPA, 1982):

•	Slough Area. This is a Spring Creek abandoned meander which is oriented north-south,
and is adjacent to the Lagoon Area's north side. It is surmised that releases from the
lagoon contaminated the slough.

•	Lagoon Area. Hoffrnan-Taff operated four evaporative lagoons located north of the
plant, in the flood plain alluvium, about 300-ft from the Spring River. Syntex states in the
Sampling and Testing Protocol (June, 24, 1982) that the lagoons were used to evaporate
"certain" chemical waste waters during the period from approximately mid 1966 to late

1979. The EPA Preliminary Investigation of Spring River Basin, reports that the lagoons
were unlined, were formed by berms, and extended about 1-ft below ground surface. The
EPA provides an estimate that 2.1 million gallons of effluent were passed through the
lagoons, resulting in an estimated total TCDD loading of 3.2 pounds (lbs).

•	Spill Area. The 1983 Consent Agreement describes the Spill Area as being
approximately 540-feet from the Spring River and located near the Irrigation Area. A
release of collected rainwater from an above ground tank designated T-24 is reported as
having occurred in this area. TCDD concentrations in samples of rainwater collected
from this tank were reported to range from 20 ppt to 130 ppt.

9


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•	Irrigation Area, Rccoids repot i tli.it \i I'At ( < > leased (torn S\nic\ one aeie ol gtottnd

imtnedialch west ol Bui!dim; V-11 fihe hevachlotophene iinmufaeHtriiii?, aic.O and used
this one acre for disposal. \ia itiitr.afioH, ofaHcued vacuum loop water, "I Ik* Missouit
\\ aiei Pollution Board appiowd miration fui 1 „!n ti,i\^ al an application rate of
approximate!) 1 .duo-gallons pa da\ Initiation occurred during laic 1 <.»71 as lepoiled in
tin- Syntes; Sampliii" and Analysis 1'iotocol i 1 ) I lu nitiVitcd uatet. ImuniT, had a
chemical o\\p.eit demand (I Ol>! idiiti at ol '"'/iuo ppm which ts indicatne thai She
water was process waste wale: and not vacuum loop wuict, 1 lie l.l' V estimated a
potential T( 1)1) loaditu! late ot 1 nm oi a total loadinu of 0 X tb.s of T('DP (based
upon I ( I )I> concent i at i>-cd at the Neosho \\aMeu atet tie it met it
plan) It is noted that no I ( I )I) anal win ol tins wale< had been conducted

•	Burn Area. 1 his aiea was initial!) suspecled of being an area used to etthef bury drums
oi Inn it Hash, how e\ ei, drum Intnal is not behe\ cd to ha\ c been likely due to the

i datively hit'h waiei table of the alluvium, S\ntc\ states in the Kanipliiu' and I'cstua-
Piofocol (June 1 MS.'h thai , Jlie Busn Au-a was used tluiin a die peiiod from the enrlv
!*><>0*s to the earl}1 ll)?0"s lie the huinmp id waste paper and oilier innocuous
comhustiblc materials."

•	Trench Area. I i\i wenches are located on S\ate\ ptopem. on the \usl skit.'ot Npimu,
Hi\ei bexond the tlood plain (on a bluff) I hese tienclies vary in Icmtih fiom
appio\iinatel> 60-feet to 4>M. It, The IT A Ihehmmai v lm estimation ol'the Spnn^ Ki\ei

Basin icports that tine was open dtnim: the time of 1 loffnian-Talf production of Agent
Orange and that two trench» were open dunnii, the time of NI l'ACi '(I opeiaiions. I he
hi'A states that " although ostensibly used In I lotfman 1 aff foi disposal of
tificontained trash, sonic mieiviewees h.r.e allctied that Nl l'A(V< I waste, both drunimed
and hulk, was put in the ticikhcs, " *\ tonne! MI I'At '<'() official is rcpoiied to have
admitted thai some of the NH'ACO > clay fillet maietial was placed in these trenches
The I I1 A estimated tl'ia! filter cake ranninp, from <\ em It. and containing a
total quant it v of f< 'HI) ranging from 1,4 to 2K(l grains is present, I his estimate ilots not
lake into account the potential presence of still bottoms, which would significantly
increase the tjuanlti) oi J (1)1) present

Table 2. Disposal Trench Usage'

	Trench Number	Oj«rn<»
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In addition to the soil subsites, groundwater has also been evaluated for potential dioxin (specific
to 2,3,7,8-tetrachlorodibenzo-p) and non-dioxin contamination both sitewide and specific to the
Trench Area. The proper decontamination and disposition of plant production equipment
potentially contaminated with dioxin was also addressed during site remediation.

Non-Dioxin Contaminants

In addition to TCDD, the contaminants listed in Tables 3 and 4 were also detected in soil and
groundwater. The Agency for Toxic Substances and Disease Registry (ATSDR) evaluated these
concentrations and determined that they were below levels of concern for human health (Syntex,
1988). Therefore, no contaminants other than TCDD are addressed by the OU1 ROD. The OU2
ROD (1993) identifies the following 12 compounds as additional compounds to be sampled for
in groundwater: dioxin; 1,4-dioxane; hexachlorophene; heptachlor epoxide; heptachlor; 1,4-
dichlorobenzene; bis (2-ethylhexyl) phthalate; 1,2,4,5-tetrachlorobenzene; naphthalene; 1,2,4-
trichlorobenzene; 1,3-dichlorobenzene; and, antimony.

Initial Response

The initial response to the creation of TCDD contaminated areas from the waste management activities of
Hoffman-Taff and NEPACCO are the actions required by the Consent Decree entered into between EPA
and Syntex on August 6, 1982. This consent decree orders Syntex to . .carry out the monitoring, testing,
analyses, and reporting set forth in its Second Revised Protocol..." Sampling for TCDD was conducted •
in 1982 (per the Second Revised Protocol) of the Burn Area, Spray Irrigation Area, Lagoon Area, and the
Trench Area. Follow up sampling to define the extent and nature of TCDD contamination in the
floodplain area of the facility was required by a Consent Agreement and Order dated September 6, 1983.
The second order required the chemicals trichlorophenol (TCP), tetrachlorobenzene (TCB), and
hexachlorophene (hex), in addition to TCDD, to be analyzed for in a limited number of samples.
Additional areas that required sampling were the Slough Area, Spill Area, and the Grid Area. This
sampling was conducted in accordance with a Sampling and Analysis Plan stipulated by the Consent
Agreement. Subsequent to the initial sampling and analysis where total dioxin was analyzed, only the
congener 2,3,7,8-tetrachlorodibenzo-p is later analyzed and reported upon. The following sub-sections
describe the sampling and results for each subsite.

11


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h

Table 3

Simiaa * \ -<,• '„r j LislflMLMfittMaite_Cfiitt«jaiiiiii
J*U* ^ trajMi Ctt
f- . C; n"; ifi.j <-,s8«*

Comaaund

t»flt»ll Irrifjlion

Tf«ich

Tnach

Wugr Ckftrer*

1,2,4,5-

««rscfcloro6eiiieae
«,<•

uich)»rotwiliciic
1,1,4.

Kimetkylixmcnc
l.2-dichlOfotx«i«nc

1.j-dichlorobeireftc
1.4-dichlorob<>ilph«Bfti

AcenjpMhcn.
Actiont
A»thr«c"» (B)

t Imamhtm
Bmm (K)

fluor»*ih«m
Btiwsle jciS
tenifi ticoh«l
Bu

phltolite
•urjrj bcniyt
pMluUtt

CfclarobeBitnc

CktjmiMt

D»»»-totyI pkthtiitc
Di »-«<[yl pfakitmt
Dtbeatefam i
IihylbcBtcot
PlBOfjmhtBt

*y»)

:ricktarometbifl<
Hoaekloropkcnt

Mtthfimt titteri«lt

oOCyftac
Fteamtkrtn i

fymt.

Tstxcnc

TridecM*

.465
44.40

.590
M

uie

2440

114,0
,118

.118

am

2.70

,2ff

M

M
M

.015

1,11©

160
.103
M

M

¦0041
M

110,1

,m
m

j»
1,38

M

IJ J0

J3S

SMS

J 750

IJ »0

jt»

•7»0

07»«
3.670

20 20

,J»

2070

JS#

1.400.0

4 no

1.350

27.60

tlJ#
.510

11.10

3410

jOOtt

M

1,110
.611

SI .0
-0015

mm
M*

mm

120.0
JJ70

JO

3J,i

.0097

JI0

43.20

S,» A5I2*
.120

«t1,t
IB

,1#®

1.40

1.16

2J0

1X0

S JO

i.»oe

3.740*

• General tret •uufdt of tU	I«f§»feft»l!j

, irriniioa. nil Welti

A
B
M

Co»c«air»i»»i II I»I|K si f,J«a ta»e tea fo»»d i» » depth of J-4 J fetl.
Cmmmtuimt m M»t» »» 4(1,300 k»«« fctea ft«ti »i * #tp«h #f S-4J f«i.
idcatlficd b»« net mntmiffcC

Source: 0U1 Record of Decision, April 1988

12


-------
'Table 4

I	Cattail

j	laiuiiJMtsiii •

i

U.i-uichlvHOsihanc	.047

S, 1 ,},2 Kuichlon/ithan:	,320

1,1 -€i\> {eiiif ne	.058

2J-bi-53-dk>*olanc	,045

2,2-dimethyM,.1-{»tct'inct}i:
-------
Burn Area

i Sanipling

1 lie SamphtHi and '1 eMinj.'. Piototol describes the Ilusn Aiea as oiiiunalh beinu a depicted aiea
le-\ than 2-tool deep, which was consequent] v has kfilled lo prade. 1 he Buin Aiea. subject t<»
sampling was defined as a lot) foot \ 50 foot u\1ai«j>tiiai aiea I he Burr. Area was divided into
50-font \ .H-foot quadtanis, hom each quadrant twit Inninus (eaeh 3-leet deep) were made using
a split-banel sampler, 1 he sampling protocol slated that two adjacent bosinps were to he
composited top,eihet, lesultmp in a t< <1 a I of lout eompostte samples 1 he icucwed podions of the
Sampling and I esting hotocol did not identify die depth intetx als planned to lie sampled A
figure ««! sample location- and tabulated resuhs is p?o\ ided in Appendix B (Old Sods, Bum
Area-1VK? Sampling).

1 he lout composite samples \\ete anah/ed tor total dioxtns In eapillat \ analysis and \telded
results oi'0,l*> ppb, 24 ppb, 1, * ppb. and (»,3 ppb total diovin I lie 2-1 ppb result appears to be in
an atca that is later identified as "Quadiant No. I .SO " Interpreting these tcMilts is pioblematie in
that I tot pui poses of this ie\ u w ) it t> nut know h lion) u hat depth inters ak disci etc samples were
taken to torm the composite sample Ilowewt. the bunt atca was desetibed as having been
co\ered with approximately ."Meet ot hacMill upon its use being discontinued, I able 5 depicts
these results.

'I abli- 5. Hum Area; HK2 Sampling Results

r Quadrant No.

, / Sample No. J

Are® of <|i»iiraat [

Total IMoxitt (ppb) 1

So

779 i

1 A5a stj t! i

U.PI J

Nit.

ISO

1,250 sc|, ft, 7

,J"" I

S'o

1 S 1

L,'^^ h

1 An 1

N,«

is;

1, 'mi -4 It. j

f. ?i» 1

1985 Sampling

Further characterisation sumnlinu conducted in 198*. with the Yctona Plant Sampling and
Analysts Plan, Rev ised Jamtai s ? t. 1°N5. as the guiding doentnent 1 he area subject to this
round ofsainplmu is an appio.xnnate 25-lt \ 3D ft icctangulai aiea wInch encompasses the
northeast quadrant of the HW2 sample area. I tgtiics depicting this sampling effort are pro\ ided
in Appendix B, Butn Area -11>S5 Sampling

Sampling consisted of completing tour borings in Hum Aiea Quadrant No, 180 (the area that
vtelded the I'>82 sample result of 24 ppb dioxtn! At eaeh boring, samples were collected from
18-inch intervals to a maximum depth of 6-feet Maximum sample interval depths wete 3 lo 4-
leet. 3 to 4 5-feet, and 4,5 to 0-lcet. Additionally. eight Ideations besond the perimeter of the
Burn Area were also sampled at 1 N-mch intervals to a maximum depth of 6-feet. All samples
were analyzed for f(i)l).

Results of the I ("HI) analysis aie identified on the liguies pros ided in Appendix B, Bunt Arca-
Sampling, and are also tabulated in 1 able (> I he two borings (I 3f>, M*01, f 36,1002)

14


-------
\ leldmg She higher 1 ("I)!) coucenUutious aie ivneialh located in I lie western huH'of (.hutdrati!
No. 1 SO, 1 he eight perintetei sample lneation-* \ielded non-de.ec; (\f>) 11 'I >0 coneentiations
acio.ss all sampled inters al>

Table 6. Burn Area Quadrant No. 18": 1*>N?









0.0- 1.5

10.30

136,1001

1.5 - 3,0

27.00

V) 4 S

18.10



4.5 - M>

16.50



i.O- 1.5

14.50

136,1002

1.5 	3.0



3.0 - 4,5

!»V-



.1 r> (, 0

ND



0.0 - 1.5

0,53

136.1003

1.5 - 3.0
n -1 <

u >

	nd" 	 ~



4 ^ n

ND



0.0 -- 1.5

0.65

136.1004

1.5 - 3.0

^ <> it

V
N!)



4A  sampling effort is described in the t "t I2MI lill I colony vK. I in ironment u Area us being approximately 150-ft \
18n It and being subdivided into six equal area plots. Table 3 of the ('112 MI	report

depicts eight wimples taken I torn each ol (he six stthaieas. each sampled acto.ss the 0 1 2-inch
depth interval I'aeh giouping of eight samples within a given plot was then composited to eieate
one sample lor analysis. Sample locations, results, and boring logs (excerpted from the
CU2MHiin;&i; report) are ptovided in Appendix B. Irrigation Atea Il)S2 Sampling. Results
ranged from 0.14 to 2'M) ppb dioxin I ahulated icsul!> are pto\ ided in Table 7.

l able 7. Irrigation Area 1982 Sampling Results

5»a«iglc Number	'	RtMili (ppb)

10fi?
linn
!0t»-S

(ill IS

WOt'i

15


-------
Sampling

further chaiactcri/ation sampling was c«mh1ik ie\« in 1985 in accordance \\»ih flic Verona Plant
Sampling and Analysis Plan. Rex ucU Junuai> 21. 1985, The area subject In this round of
sampling is dcni'ibed as ihc ?5-foo? In X 1- fool southeast eomct from which ihe t%2 composite
sample nnmbei NH) 1 was demed from. '1!«,' subject aica was isuinhvided »nit< four quadrants in
which two '.'-tout Woiings weic made, bach I ¦ (not deplli inlcnal liom each paired boring was
composited am! nnaly/ed tin dioxin. Addition.illy, a single composite sample was created from
each of the eight 0 1-foot depth inteivaU and sampled foi FCT, TCB and HbX. Lastly, two
bo!mgs each weie located 10-loot liom belli the caM and south side-, of Otiaduntt 1UU1 (lour
tola! borings) ami .sampled lot dio\m

Dioxin tesuh\ of uiu!vm\ foi the o 1 -foot inters a I vompoMtc sample-^ eollccied within
Quadtant 1(H)! ranged from OA" to t ,M ppk and umged liom N!) to 0 ??. ppb tor the 1 0 .'.0-
fbot intcivnl composites. I luce ol the !>» icMilt o! 7.-10 ppb), Sample locations with associated results arc
depicted on the I &1; tiguie pnuided in Appends*, li, Inigation Area-l^N.s Sampling. I'abulated
results are summarized in I able 8,

l able 8, Irrigation Ares 1985 San>t>U- Kesults



Dejjifi luUrvft! it».)

Kt-Mih

3195.2001



1,60

t«; :e 1

M>

			I"1""'1"1"1	'	1		'¦ """¦"

3195.2003

i, !•>

1 sa

,0 - 2,0

0 3?

3195,3002

r* '.o-l.o |

MvK

.0 - 2,0 i

\'I)



l0 - 1.0

1,0-10 1

f) W

~"nd

!>ivt(HH

(Juiuiruut IUO1 iVrtmek*? Samples

ND

y? 3,m>4

tin 1 (t !

NH

»>5. W?



;

p»5 ?< »¦ is

O

o

o

J".ju
~ 4> 11 duplicate)

Spill Area

1982 Sampling

The Spill Area was not identified in the 1982 Consent Order and therefore was not part of the
1982 sampling effort.

16


-------
Il>S5 Sampling

Initial characterization sampling ofthc Spill \iea u as conducted in If>85 in aecoidaocc w ith thv
Verona Plant Sampling aiul AnalyMs Flan, Revised ia;tMai\ ? I, K'N* i he atca subject to

sampling is described as being an N(t¦ { stsbdn ided into .b). loot \ ?U-tooi squalen Sampling consisted
of the collection of otic sample across a <• to ?• inch depth tsom the center of each lb Moot squaie
i'bc four samples collected alone, each cast-west omitted gtotip ot ?0 fool square^ weie tlien
composited. 111 >1) lesults utoged iioin NI) to s oo ppb Sample location and results ate depicted
in the l\*c! tiguie piovided in \ppends\ H, SpiM Aiea-l^Ns Sampling I ahulatcd results aie
provided in Tabic *>

Table f. Spill Are# 1985 Sampling Results

889

; Tlmlv>

t

0.3

I 3907

.20

3979

NI)

«')?5

r oil

399?

0.82

f 3943

| 0.83

Provided

a eo

Lagoon Area
Iun2 Sampling

1 he CI I2MHMI icpoi i dated Api il, 1MX b depicts ihc Lagoon. Area as a 360-foot x 300-foot
ai ca The Second Rev bed Sampling uml I estmg Protocol, August 1982, describes the lagoons as
ha\ ing been less than 3-foot deep an«l deset tbes the tn\ estigation of the Lagoon Area as being
tfiiiK 4-foot deep split-barrel holing*, placed across tiie lagoon with paired adjacent borings
being composited togethet to yield a total o! I S composite samples 1 o accomplish this, the
lagoon area \ui«. stibdh ided into til teen no. 116

I 2JIP

N.i I'M

0.41

No. II?

I 2.10

fo. I'H

0.29

No 1SS

1 9.00

to, I

1 ?u

No. m

! (1.

4. )<».S

2.30

No. 19n

i .Mi





•value is the average of duplicate analysis

17


-------
1985 Sampling

Further characterization sampling was concluded in 1985 in. accordance with the Verona Plan!
Sampling and Analysis Plan, Revised January 21, 1985 The area subject to this round of
sampling is described as the five WMoot x 120-foot subarca- liotn which the following 1932
samples were collected: number,-. 188. 189, 191, 192 and 1^3,1 or this 1185 round of
investigation, each ofthese live subarcas were further di\idol into eight 30-fout k 30-lout
squares in which each square a single split-barrel boring \va~ placed. Samples were collected at
18-inch intervals with composites created ironi each depth interval from each of four adjacent
borings located u ithni she same '<0- foul ,\ 1 20-foot subarea Discrete .sail,pies were .stored for
indiviihuil analysis, as needed Additionally, seven borings were placed beyond the 1 agoon Area
perimeter am! sampled at the same depth intervals with each sample analyzed individually. The
Jacobs fngineeiing Group figures provided in Appendix B. Lagoon-1985 Sampling, depict these
sampling locations and results.

The first 18-inch depth interval yielded the highest TCDD concentrations observed at the facility.
Single composite samples collected from suhareas 193 and 191 have reported respective TCDD
concentrations of 1,045 ppb and 5«> ppb The four aliquots to each of these two composites were
individually atnlv/ed and had the following TCDD results; 1160 ppb, 1170 ppb, 5.3 ppb, 0.18
ppb (composite result of 1046 ppb); and, 22.3 ppb, 0.36 ppb, 442 ppb, 4.70 ppb (composite result
of 5(> ppb). The remaining composite samples from the first. 18-inch depth interval yielded
icsults ranging from 0.07 to 14.2 ppb TCDD. These results arc depicted on the previously cited
figures of Appendix B, Lagoon - 1985 Sampling.

Results from the 1.5-foot to 3.0-foot depth interval exhibited a .significant decrease in TCDD
concenu at ions. The boring locations from which the 1046 ppb composite result was obtained,
yields a composite TCDD concentration of 30.9 ppb from the 1,3 to 3.0-tt depth interval. The
aliquots for this composite were individually analyzed and yielded the following TCDD results;
NI). NIX 22.8 ppb, and 5.3 ppb'. The remaining composite samples at this depth interval yielded
TCDD results ranging from ND to 1.5 ppb. These results are depicted on the previously cited
figures.

Composite samples from the 3 to 4.5-foot depth interval yielded TCDD results ranging from ND
(3) to 6.8 ppb. Composite samples from the 4.5 to 6.0-foot depth interval yielded I'CDi) results
ranging from ND (6) to 2.1 ppb. The previously cited figures depict these results.

The perimeter samples yielded a high TCDD result of 3.6 ppb obtained from one sample
collected at the 1.5 to 3.0-ft depth interval, All other perimeter results ranged from ND to 2.7
ppb. These results are also depicted on the previously cited figures.

Slough Area

1982 Sampling

The Slough Area was not addressed in the 1982 Consent Order and therefore was not sampled in
1982.

18


-------
j W5 Sampling

Initial chaiacteri.Mtion s.uiiphut? oi'ihe Slough \iea u,h conducted in I MS^, 'I he Verona Plan)
Sampling ami Analysis Plan, Revised htmuuy ? 1 . 1MK\ was the guiding document on how
sampling was to lie conducted. Thitteen sample location.-, approximate!)- 100-foot apart, were
identified along iIh* centesline of (he slough. At each location, samples are reported lo have been
collected hom the It lo 12-ineli depth interval with a single composite sample created aeross the
entire 12-inch inten al. Additionally, al lout loeaiions discrete samples from eaeli opposing hank
were obiaitied (sample depth undetermined from leviewcd documents). The Jacobs I'ngineermg
t Irotip figure provided in Appendix H. Slough Aiea I (>NS Sampling. depict (Ikno sampling
locations and termlK

Results of the eomposite samples collected Itotn along the slough's eemei line ratine liom Nil lo
3.K ppb k"()l>, Bank disereie sample tc-mlts wete Nf), with the exception of two whieh had

1 ( "l>i> results of and U ?7 ppb. I ot purpose*. ol'thts lepoit. samples aie identified by the
Northing ordinate of the sample location. I Ik' Ni>Miiint», ordinate closest to the I agoon Atea is
" The Jacobs fngmecrm.e ligute pio\ ided in Appendix B. Slough Area-1 <)K5 Sampling,
depiets sample locations and icsulh I able I 1 pon ide> tabulated composite sample results

Table 11. Slough Area 1985 Composite Sample Results

48(X) 1



5500

2,9

|>h«! t



t!

a "»s

51 ii)(« i



0

NM

) |



ISO «

O |S

) ~ J

0 14

	

Trench Area
I'W.* San ip Inn;

lite S\ntex 1(>82 Seeond Reused Sampling and Testing Piotocol is the document whieh guided
the sampling conducted at the I leneh Area I wehc botings weie plaeed near the perinselei of
the trenches and a total of twenty woe loeated withm the trenehes identified as Numbers 3. 4,
and 5. Perimeter boring depths ranged from ? to I 5-leet; treneh hosing depths ranged from h to
13-feet Sample intmuls are repotted as being fl to 1 - foot deep and as also being diserete. Watei
encountered tn treneh borings was also sampled. Sample locations and reMilts are depleted in the
figures and tables provided in Appendix 11, I reneh Area-1 (>X2 Sampling.

Perimeter boring sample results range from Nl) to 18 ppb total dioxin, Dioxin results obtained
from borings plaeed within trenehes 4, and 5 ranged from 0.033 ppb to (>'> ppb. Additional
contaminants identified were ehloi mated ben/enes, chlorinated phenols, PC lis. and polyeyelic

19


-------
atomalie ImliutMrbons (l*AHs>. and 2-tTietli\lnaphiltalene Groundwater results exhibited many
of the same organic compounds

1985 Sampling

Sampling conducted in 1W5 v.,is enided in the \ coma Flan! Sampling ami Anahsis Plan,

Revised January 21. I*>X5. A total ofeight angle boring.-. vote drilled beneath the Ircnch Area
and placed in pairs alongside the following 11>S2 borings: 154, I 5K, Ifi!, ami l<> v Results of this
imestigatson arc pun ided in Appemli\ B, i send; Aiea- 1US5 Sampling, 1 CPI) icstilb wcic nott-
detects. except foi one u still ol 0,05 ppb 1 he ptevaleni oiganie compounds delected include 2-
mcth>lnaph;halcne„ naphthalene, phenanthicnc. and bM^-ethylhcxyDphthalate 'I lie Reused
Remedial Aliermrtivev Rejvtt. Mauls ?. I*»ss states that ,.i event angle borings underneath the
trenches disclosed no dovuiv.utd ! CI >!) nngtaiiou,'

Grid Area

1982 Sampling

The < irtd Area \v as not addressed in the 1982 Consent Order and therefore was not part of the
1 sampling effort,

1985 Sajyp|!iit<

Initial characterization sampling of the t iiid Aiea was eondaieted in I(pptn

212

3.10

1 "a n'upi

1.56

0.18

> 11

2,00

14S

n r

Ui:-

1,60

166

ti k.

14

n os

I" >

n 15

116

0.7?

?• 11

n 14

194

'*¦

?P>

n \2

pi,1

0 sn

ins

0 IC

1 "S

0.41

244

lt«

214

0.37

r«4 1



1 "ii

i) ?l



20


-------
It is noted tlnil composite samples 15(». I '»<> l"s. 1 /<>, P" and 1K6 are adjacent to one
another which mokes for a contiguous ?so.t>u«i square foot utea haung composite sample TCDD
results raitgini! lions 0.15 to 1 ,00 ppb 'I('HO

Reports ol atiat>sis lor the iion-'I n>l> aiuihtcs t'cnetully icpoited low concentrations, except for
hexaehlorophene, which tanged from Kf> to ,V?40 ppb The sample with the hi^li
hexachloropheiie detection was en I lee let! mv: the slough (sample no.

Groundwater

In 1 1>NY ten shallow (i 5-leet below j'touml suiiaee jtv,s|> }«.totitul ujtei monitoring wells, MW-l
tinoiiL'ji \t\Y -10. \\ etc installed oti the lloi nlphtm u ithin the Svntcx piopetU boundai \

I Appendix t', l*tj;uie I L 1 he nmmtui nip pieeaam entaded sampling all well1- nionthlx lot three
months and then quatterh until thv etui of the lust yeat (I^Nft). Sample-, were analyzed tot
Ft 1)1) and all pnotih pollutants (Appendix iI'notits Pollutants). Aftet the fust xeai of
monilonns',. it was detetmined that le\els of oiuanic and is»1), Kyntex pioposed that I (i)D be eliminated from the list of
monitored compounds I I'A ,eais I able 1 * lists the compounds analx /cd in samples collected during thts vyeat pet tod
I Radian.

Table 13, Groundwater Aualytes of 1987 -1989

Amihtos

fl	.'"I'd,

i >>ii.tu. n\it) |

I cad11 ! I

I ci.il Of,M»l!i ( .lihi'll J

ftf, and -IhB.
Installed Trench Area monitoring wells were MW-l I. -12,-13,-17, and -18.

? 1


-------
The floodplain monitoring wells were completed at varying depths: MW-14A and MW-15A at
approximately 15-feet bgs; MW-15B and MW-16B at the bedrock-alluvium interface (30-50 feet
bgs); and MW-14, MW-15, and MW-16 approximately 25-feet below the alluvial-bedrock
interface. It is noted that the boring log for monitoring well MW-15B states: "40.6', bedrock,
medium gray limestone with some chert fragments, return fluid is dark gray to black with a very
offensive 'sewery' odor."

The Five Trench Area monitoring wells (MW-11, -12,-13,-17,-18) were to be completed to
depths approximately 5-feet below the elevation of the river (~l,235-feet above mean sea level
(msl)); however, this was not achieved during installation (Tetratech, 1989). Monitoring well
MW-11 was intended to be the upgradient monitoring point, and was completed shallower
(1,247-feet above msl) than the planned (1,235-feet above msl) depth. Monitoring wells MW-12,
MW-13, and MW-17 were respectively completed at 1,155-feet, 1,167-feet, and 1,160-feet
above msl - all nearly 100-feet deeper than planned. Monitoring wells MW-12 and MW-13
appear to have been screened within the confining unit between the upper and lower aquifers at
respectively 1,165-feet and 1,167-feet above msl, while monitoring well MW-17 appears to be
screened at elevation 1,160-feet above msl which appears to be just above the confining unit.
Downgradient monitoring well MW-18 was completed at an elevation of 1235-feet above mean
sea level in accordance with the work plan. Cross-section views of these monitoring wells are
provided in Appendix C, Trehch Area-Original Monitoring Wells.

Upon installation of the Trench Area monitoring wells and floodplain supplemental monitoring
wells, a different monitoring plan was established. Of the monitoring wells located in the
floodplain, MW-1, -5, -6, -7, -9, -14, -14A, -15, -15A, -15B, -16, and -16B were sampled
quarterly. The floodplain monitoring wells dropped from the monitoring program were
interpreted as not being able to intercept potential releases from OU1 areas. Of the Trench Area
monitoring wells, only MW-12, -13, and -17 were monitored quarterly. Monitored analytes were
those previously identified in Table 11 plus the following additional parameters: calcium,
magnesium, acetone, dichloromethane, 1,4-dichlorobenzene, and xylenes (total) (Radian, 1992).

Pre-OU2 ROD sampling of floodplain monitoring wells yielded multiple samples containing
dichloromethane at concentrations ranging from 19 jig/L to 1,000 |ig/L, which exceeds its MCL
of 5 fig/L. However, these results were sporadic, with monitoring wells typically having one hit
followed by non-detect results in subsequent rounds of sampling. The following compounds
without associated MCLs were also detected in monitored floodplain monitoring wells: acetone;
chlorobenzene; ethylbenzene; xylenes; toluene; and carbon disulfide. One Trench Area
monitoring well (MW-18) had one sample (4/25/91) containing dichloromethane at 66 p.g/L; also
monitoring wells MW-11 and MW-18 had detects for acetone (46 |ig/l to 4,949 ng/L). It is
noted, that Trench Area monitoring wells MW-11 and MW-18 were dropped from the
monitoring program, each after having yielded significant concentrations of either acetone and/or
dichloromethane. Monitoring wells MW-12, MW-13, and MW-17, were reported as "dry" over
six sampling events from January 1991 to April 1992.

22


-------
Basis for Taking Action

QUI - Soil

The 1988 OU1 Record of Decision Declaration states that the primary contaminant of concern at
the site is 2,3,7,8 TCDD. Other organic and inorganic compounds are present in both soil and
groundwater, as summarized in Tables 3 and 4. However, the Agency for Toxic Substances and
Disease Registry (ATSDR) determined that the concentrations of these compounds are below the
level of concern for human health. Therefore, the basis for the action taken is due to the presence
and concentration of TCDD/dioxin in soil.

At the time of the OU1 ROD, dioxin was considered one of the most toxic compounds known,
with the LD-50 dose level for male guinea pigs being 0.6 (ig/kg and also being highly toxic in all
species tested. Animal studies had demonstrated that dioxin is teratogenic and fetotoxic in mice,
rats, rabbits, monkeys and ferrets and is fetotoxic in monkeys. At the time of the ROD, animal
studies supported the conclusion that dioxin is also an animal carcinogen. The ROD states that
the EPA's Carcinogen Assessment Group has assessed dioxin as the most potent animal
carcinogen evaluated (as of 1988) (ROD Declaration, 1988).

The 1988 OU1 ROD states:

Continued long-term direct contact with or ingestion of soils would present the greatest
threat to human health. This exposure potential for humans can be limited by controlling
site access. Ingestion of dioxin could occur if fish containing levels of dioxin from the
Spring River were consumed or by direct ingestion of Syntex, Verona plant soils.

Wildlife (deer, turkey, rabbit) in the slough area would be susceptible to contamination,
as historically there were not controls on animal access in this subsite area.

Inhalation of dioxin-contaminated airborne particulates presents a potential route of
human exposure. The principal concern for inhalation of contaminated particulates would
be for Syntex, Verona employees and onsite workers during periods of onsite
construction activities involving disturbances of contaminated soils. Mitigative measures
exist to control this risk.

Ingestion of plants grown in contaminated soil represents a potential exposure route,
although there is uncertainty regarding the potential for uptake of dioxin in plant life.
Dioxin uptake in many plants appears to be minimal. This potential pathway would be
limited by controlling site access. Land use restrictions represent another effective means
of controlling this exposure potential, although potential uptake in plants would be
unaffected.

The most significant environmental problem which could be expected at Syntex, Verona
is the transport of dioxin to the Spring River due to erosion of surficial soils. A limited
potential exists for surface contamination to reach the river by transport during rainfall
events, particularly during periods of flooding at the plant site which lies in the floodplain
of Spring River. The potential for suspended contaminated sediment to reach the Spring

23

I


-------
River during normal flow conditions is much lower. Stormwater is normally retained on
site until it is absorbed into the ground.

The threat to human health and the environment due to bioaccumulation in fish as a result
of the release of dioxin from the Syntex, Verona site appears to be decreasing. Although
fish in the Spring River have shown detectable levels of dioxin, contaminant levels have
consistently been below the advisory level of 50 ppt designated by the Food and Drug
Administration since 1982.

The EPA concluded that certain types of non-residential exposure to soil contaminated at 20 ppb
dioxin are below a level of concern for public health. This conclusion was based upon an
ATSDR advisory that the average lifetime daily dosage in a commercial setting contaminated at
20 ppb dioxin is 33 fg/kg b.w./day and that this calculated exposure is below the average daily
dose estimated to be of concern for public health in the 1984 paper written by Kimbrough, et al
(ROD Declaration, 1988).

OU2 - Groundwater

The OU1 ROD (1988) stated that the existing groundwater data was insufficient to determine
groundwater remediation needs and that further monitoring was required. In response, additional
monitoring wells (MW-11,-12, -13, -14, -14A, -15, -15A, -15B, -16, -16B -17, and -18) were
installed and subsequently monitored. As part of site remedial investigation activities, acquired
groundwater data was used to estimate site risks associated with exposure to groundwater. The
risk assessment modeled exposures to a family living immediately downgradient of the site that
was dependent upon a well completed within the shallow alluvial aquifer. The resulting
calculated risks were within the acceptable risk range established by the NCP (OU2 ROD, 1993).

The OU2 ROD (1993) declaration states that no further remedial action is necessary for
groundwater at the site to ensure protection of human health and the environment as groundwater
contaminant levels are within the acceptable risk range established by the NCP. However, the
EPA assessed that an additional two years of groundwater monitoring would be required and that
a groundwater risk.assessment would be conducted at the end of the two year period. This
assessment would be conducted to ensure that groundwater contamination does not pose an
unacceptable risk to human health or the environment.

IV. Remedial Actions

QUI - Soil

The selected remedy is excavation and thermal treatment of soils contaminated with dioxin
above the 20 ppb action level. For soils containing less than 20 ppb dioxin, the selected remedy
is in-place containment under a vegetative cover. The ROD Declaration, Section 4.0, "The
Selected Remedy," states:

Based on the information available to evaluate the remedial options against the
previously described criteria, the EPA hereby conclude that excavation and thermal

24


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treatment of soils contaminated with dioxin above the 20 ppb action level is the Agency's
preferred

alternative...For those soils containing less than 20 ppb dioxin, the EPA hereby
concludes... that the in-place containment of these soils, under vegetative covers is the
preferred alternative...

Action levels are described in the ROD's Section 4.1, "Action Levels";

An action level of 20 ppb dioxin, based on the 95 percent confidence level for all areas of
the Syntex, Verona site, is appropriate for the cleanup of dioxin-contaminated soils at the
site; the areas which require cleanup to this level are the Burn Area, Irrigation Area and
the Lagoon Area. Soils in these areas which contain dioxin greater than the action level
will be excavated and thermally treated to destroy the dioxin. The remaining areas of the
site contaminated with dioxin at levels between 1 ppb and 20 ppb will have vegetative
covers established and maintained to reduce the mobility of the dioxin. Surface
concentrations will be determined at the 95 percent confidence level, using the procedure
utilized during the cleanup of other Missouri dioxin sites...

The selected remedy "in-place containment" is described in the ROD under Alternative 3: "In-
Place Containment." This remedy has multiple components which are specific to one or more
soil subsite areas:

•	Alternative 3A: "One-Foot Vegetative Soil Cover." This alternative was proposed for
the Irrigation Area, Burn Area, and Lagoon Area and would be performed either as a sole
remedy or in conjunction with excavation.

•	Alternative 3B: "Rock Base with Asphalt Cover." This alternative was proposed for the
Spill Area and included the placement and grading of a 4 to 6-inch nominal stone layer
capped with a 4-inch asphalt layer.

•	Alternative 3C: "Clay Backfill with six-inch Vegetative Cover." This alternative was
proposed for the Slough channel and included backfilling and grading the surface to
produce a gradual swale. Topsoil would be placed to a depth of 6-in and vegetation
would be established.

•	Alternative 3D: "Gravel Backfill, Twelve-inch Clay Cap, Twelve-inch Vegetated
Cover." This alternative was proposed for the Trench Area and included the backfilling
of any depressions to original grade, placing a 12-inch layer of compacted clay extending
10-foot beyond the trench borders sloped to facilitate runoff, placement of 12-inch of
topsoil, and establishment of a vegetative cover.

The ROD, Section 4.2 - "Subsite Remedial Action," describes in more detailed fashion the
selected remedy for each subsite:

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•	Grid Area. The ROD states the average dioxin surface concentration as 0.15 ppb with
the highest as 3.1 ppb; ".. .Maintenance of the existing vegetative cover to prevent
erosion will provide adequate protection of the public health."

•	Burn Area. The ROD states the average dioxin surface concentration as 6.5 ppb; the
highest surface concentration as 24 ppb and at depth as 27 ppb; . .all soils containing 20
ppb or more dioxin based on the 95 percent confidence level sampling, will be excavated
up to a 4-foot depth, to bedrock or to a dioxin concentration less than the action level
whichever occurs first..

•	Spill Area. The ROD states the average dioxin surface concentration as 2.0 ppb and the
highesf as 4.8 ppb; because this area is overlain with gravel and a 10-mil polyethylene
sheet which will not support a vegetative cover, this material was required to be removed
and backfilled with topsoil to be revegetated.

•	Irrigation Area. The ROD states the average dioxin surface concentration as
approximately 4.0 ppb with the highest being 29 ppb; ; ".. .all soils containing 20 ppb or
more dioxin based on the 95 percent confidence level sampling, will be excavated up to a
4-foot depth, to bedrock or to a dioxin concentration less than the action level whichever
occurs first..."

•	Lagoon Area. The ROD states the average dioxin surface concentration as 279 ppb with
the highest being 1380 ppb; ".. .all soils containing 20 ppb or more dioxin based on the
95 percent confidence level sampling, will be excavated up to a 4-foot depth, to bedrock
or to a dioxin concentration less than the action level whichever occurs first..."

•	Slough Area. The ROD states the average dioxin surface concentration as 1.5 ppb with
the highest being 8.4 ppb; ".. .a vegetative cover will be established and maintained over
all soils containing 1 ppb or more dioxin. This activity would involve placing clay in the
Slough channel as a backfill material and grading the surface to produce a gradual swale.
Six inches of topsoil would then be added to.support a vegetative cover."

•	Trench Area. The ROD states the average dioxin surface concentration as being less
than 17.3 ppb and the highest being 67 ppb (these samples being composited from the
surface to depths of 9 to 12-foot); "Excavation of the Trench Area may result in
migration of contaminants located there as the excavation activities could disrupt the low
permeability layer beneath the subsite. For this reason, remediation of the Trench

Area.. .will include: backfilling trench depressions to original grade with gravel
aggregate; installation of a 12-inch clay layer that will extend 10-foot beyond trench
boundaries; and subsequent installation of 12 inches of topsoil to support a vegetative
cover. In addition, a gravel drainage-interception trench will be installed upgradient of
the trench area.. .Additional subsurface monitoring, described in Section 4.2.11, will be
implemented concurrently with this remedial action..."

•	Groundwater (4.2.11). "Activities under this first operable unit will not include
remediation of the local groundwater as the EPA at this time does not have sufficient data
on which to determine groundwater remediation needs. Efforts to assess and monitor the
local and area groundwaters will be initiated concurrently with implementation of this
plan.. . this assessment and monitoring effort will .include the installation of groundwater

26


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monitoring well clusters in the Trench Area and upgradient and downgradient of the plant
site."

Further detail regarding the scope of the intended remedy is provided in the ROD's Section 5.0,
"Statutory Determination." Paragraph 1 of the referenced section, states in part that "...Federal
and state health officials have determined that removing all soils exceeding 20 ppb dioxin in
industrial or nonresidential areas, and establishing and maintaining vegetation covers over all
soils containing less than 20 ppb dioxin .. .will adequately achieve protection of public health."

/

After issuance of the ROD, however, it appears that further communication occurred between the
EPA and Syntex regarding implementation of the selected remedy. Syntex states within the
Implementation Plan (Section IV) that . .EPA has advised Syntex that it interprets CDC's
guidance as requiring removal of all soils at the surface containing an average concentration of
20 ppb or greater..Syntex's implementation of the remedial action reflects this interpretation
- Syntex resampled surface soils of subsites, identified by the ROD as requiring excavation, for
the purpose of redefining which subsites required excavation based solely upon surface
contamination.

OU2 - Groundwater

The selected remedy is "No Action with Continued Groundwater Monitoring" and requires the
following:

i

•	2-year duration of continued monitoring of the monitoring well network;

•	Installation of additional monitoring well clusters that are to be installed both upgradient
and downgradient from the facility;

•	Quarterly monitoring of floodplain wells for twelve additional compounds (dioxin;
heptachlor; heptachlor epoxide; 1,4-dichlorobenzene; bis [2-Ethylhexyl] phthalate;
antimony; 1,2,4,5-tetrachlorobenzene; 1,2,4-trichlorobenzene; 1,3-dichlorobenzene;
naphthalene; hexachlorophene; and, 1,4-dioxane);

•	After the first year, monitor semi-annually all parameters whose levels have remained
constant;

•	Conduct a risk assessment at the end of the 2-yr monitoring program having the objective
of ensuring that the "no-action" remedy remains protective of human health and the
environment.

Remedy Implementation

QUI - Soil

The implemented remedy is reported upon in the Syntex document titled "Syntex Agribusiness,
Inc. Verona Facility Implementation Plan," July 29, 1988. Section IV of the Implementation
Plan, states: ".. .EPA has advised Syntex that it interprets CDC's guidance as requiring removal
of all soils at the surface containing an average concentration of 20 ppb or greater..." Syntex
proceeded to use the 95 percent confidence level sampling protocol to determine which surface
soils within the Burn Area, Irrigation Area and the Lagoon Area contained TCDD at levels
greaiter than 20 ppb; it was determined that excavation was only required at the Lagoon Area. ,

27


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Grid Area

The implemented remedy at the Grid Area was maintenance of the existing vegetative cover to
prevent erosion. A vegetative cover has been maintained in the areas indicated by the 1985 Grid
Area soil sampling as potentially having surface soil TCDD concentrations between 1 and 20
ppb.

Burn Area

The Burn Area, in accordance with the ROD, was to have been excavated of all soils containing
20 ppb or more dioxin based on sampling at the 95 percent confidence level. The Syntex
Implementation Report states that the Burn Area surface soil was sampled by the verification
sampling protocol and the resulting three composite sample results were 0.3 ppb, 0.3 ppb and 0.5
ppb TCDD. These results yield a TCDD concentration of 0.57 ppb at the 95 percent confidence
level. The verification sampling was conducted over a 50-foot x 100-foot area as depicted by the
referenced plan sheet. No reference point and/or survey mark identifies the sampled area with
respect to the previously sampled subareas of the Burn Area; however, the resampled area
dimensionally matches the burn area as described for the 1982 investigation. The plan sheet
provided in Appendix B, Burn Area-Remedy Implementation, depicts verification sample
locations and results. Based on the sampling of surface soil at the 95 percent confidence level, no
excavation of soil occurred at the Bum Area.

The implemented remedy did not address dioxin contaminated soil at depth, which exceeded 20
ppb for TCDD, as identified in the 1982 and 1985 investigations.

a

Irrigation Area

The ROD states that all soils containing equal to or greater than 20 ppb dioxin, based on the 95
percent confidence level sampling, will be excavated up to a 4-foot depth, to bedrock, or to a
dioxin concentration less than the action level, whichever occurs first. Prior to initiating any soil
excavation at the Irrigation Area, Syntex re-sampled a portion of the Irrigation Area surface soil
in accordance with the verification sampling protocol. The resulting three composite sample
results were 2.6 ppb, 7.6 ppb, and 3.6 ppb TCDD which yields a result at the 95 percent
confidence level equal to 9.08 ppb. The plan sheet provided in Appendix B, Irrigation Area-
Remedy Implementation, depicts verification sample locations and summary results. As a result,
no soil was excavated from the Irrigation Area. The Irrigation Area was capped according to the
Syntex Implementation Plan. The Syntex Implementation Plan stated that due to surface runoff
ponding in this subsite area, topsoil was placed into the area such that final grade was at
elevation 1255-feet. This fill is stated to have been traffic compacted and subsequently
established with vegetation.

The pre-excavation verification sampling was conducted over a 60-foot x 75-foot area as
depicted by the referenced plan sheet. This resampled area corresponds to the Irrigation Area
subarea sampled in 1985, except being somewhat smaller as the 1985 sampled area is described
as 75-foot x 84-foot. Also of note, is the relationship of 1985 sample 195.2005 to the subsequent
pre-excavation verification sampling. Sample 195.2005 was located beyond the boundary of the
Irrigation Area on the east side (southeast of photolysis dike) and had a duplicate set of analyses
performed on its 0 to 1-foot deep sample interval that yielded TCDD results of 27.20 and 7.40

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ppb. It does not appear that the pre-excavation verification sampling adequately addresses the.
TCDD surface soil contamination indicated as present by sample 195.2005. It appears very likely
that surface soil proximate to sample location 195.2005 was not part of the area subjected to pre-
excavation verification sampling.

Spill Area

The EPA approved a closure plan for the Spill Area in correspondence dated October 6, 1995,
that called for leaving in place existing gravel and placing an additional four to six-inch nominal
stone layer over the gravel base, which then would be topped with either asphalt or concrete.
Documentation of the implementation of the approved plan was not part of the reviewed
documents. However, the Spill Area is now paved with asphaltic concrete.

Additional dioxin soil contamination was discovered in March 1997, located near the former T-l
dike in the Spill Area. The EPA Remedial Action Report, dated September 1998, reports that
soils contaminated with dioxin above 20 ppb were excavated and transported to a commercial j
incinerator for thermal treatment. The excavated area is reported to have been backfilled with a
minimum of 1-foot of clean fill dirt and capped with an asphaltic cover. Completion of this
action occurred in December 1997. Other than the cited EPA report, no other documentation of
this cleanup was reiviewed.

PCBs were also discovered in April 1997 at the Spill Area near a small electrical building during
trenching operations related to burying power lines. The soil was reported to contain PCBs at
1,000 ,ppm. A removal action was initiated in August 1997 in accordance with an EPA issued
Removal Action Memorandum dated July 17, 1997. This removal action was completed in
conjunction with the aforementioned dioxin removal (EPA, 1998).

Lagoon Area

The ROD states that all soils containing 20 ppb or more dioxin, based on a 95 percent confidence
level, will be excavated up to a 4-foot depth, to bedrock, or to a dioxin concentration less than
the action level, whichever occurs first. The Syntex Implementation Plan states that lagoon
surface soils containing an average TCDD concentration of 20 ppb or higher as determined by
the 95 percent sampling protocol was excavated. Final verification sampling areas and results are
depicted on the Syntex plan sheet titled "Lagoon Area - Final Verification Sampling Areas and
Results." Excavation limits and verification sampling summary data are recorded on the plan
sheet titled "Lagoon Area - Final Verification Sampling Areas and Excavation Extents," dated
July 28, 1988. Both of these plan sheets are provided in Appendix B, Lagoon Area-Remedy
Implementation.

Preceding excavation, Syntex resampled the Lagoon Area using the approved verification
sampling protocol for the purpose of identifying the average TCDD concentration in the top two
inches of soil. Excavation then proceeded based upon the obtained results. Syntex reports that the
initial excavation was not sampled per the verification protocol until after the area was excavated

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lo a depth of IK-mchc-., except whcio native soils uei c encountered a: .1 .shallower depth,
rxeuuitnm would then ha\c pioeccded hi r I >' inch lifts will* \ ertliealion sau\)>Stnj.' umducted
a I lei each lilt was completed "I he tint sol and into iin mIs of \ ei dicuSion sampling tesultx were
not present in the rc\ lowed implementation fepou Yc.'tioa! cxea\ ation limits are also noj uell
de lined, a* excavated areas are identified as has mg been e\ea\.i!ed !<< depth-, of either gt eater
then 1 .^inches. les.s than incites ut as 1 to o inches

hxenx ation limits and \etittealion sampling Miinmat\ data ate tveuided on the pre\iousl\ eited
plan sheet. I he referenced plan .-sheet depicts 1 seavation limits which encompass the h'X.?
sampling Mibaiiea^ numbered Iu 1 and IV t fvcavaPuu i> depu led as then geneialh pioveeding
in a swath dueeted In the multicast and ending neat the old slough aiea h\ea\ aiion is depleted
a- i»a\tt!ii proceeded to an undisclosed depth greatci than 1 inches in the two adj.«ec»t Pi Moot x
of! tool Mitxireu- that conespotid to (Ik I SS et tmpodie samples \ ieldmu I (1)1) results of I ti lo
and *>(> ppb (composited across a 0 t "v|>«ot dcptld I hicv tlx to the east of this l'grcatei than 1 ?-
ineh excavation" is an aiea appioximateh I ?0 fool \ nil-fool lepoifcd as hemp. e\e.i\ated to a
deptli "less than l^-inehes "" 1 his aiea geneialh cones ponds 10 tin; t astern Ml- lout of die 1 1>S 2
sample Mtbareas I'M and l''\ Remainum cxca\atcd aie o, aie lepoited as being ? to odnches
deep

Veiifuation sampling was conducted in ex*. a\atcd aseas, non exe.oatcd lagoon aieas and in a
minimum I <)-li*n! \\ ide petimetei extending bc\4 to ! ',V' pph '! ( 1)1); 1 M to S0.0 pph I ( 1 )1 > id Hon ¦
excavated layouts aiea.s; ami to 1 7,5 * pph 1 ( iM> in the peiimctet adjacent to excavated
aseas. Yei ification sample u subs aie tabulated in I able 14

Table 14, Lagoon Area Verification Sample Results

Nmi-F.ia



\ P . .1
l_ ——- 1

.ilJliirilL.:
~4M~

3600

2A2

f 3600

6.30

3500

17.32

[ 1600 1



3 500

i; 1

| _ 1



3600*

1 f.\

j — I



4X0"



j .... I



4100









I'criitu Ivt

TCTifl

s ?«

!>¦» t»s

L! v

Reviewed records did riot definitive!) .state whetltei .soil previously charaetefi/cd as
contaminated with IX'1)1) a! a eouconttatioji of" id o pph at a, depth of UMWt was addressed by
ihe excavation deseiibed as "greatei than 1 .'-inches,'1 1 he re\ icued cxeeipts from the Ryntex
Implementation Plan did not identity specific depths ot cxca\ alion, fxeavatcd ateas are reported

to ha\c been backfilled with soil, wish the top <>• inches being lopsoil |S\nfe\, IV)SS).

Slough Area

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The ROD states: . .a vegetative cover will be established and maintained over all soils
containing 1 ppb or more dioxin. This activity would involve placing clay in the Slough channel
as a backfill material and grading the surface to produce a gradual swale. Six inches of topsoil
would then be added to support a vegetative cover." The Implementation Plan reports that the
Slough Area was stabilized by having been backfilled with clay, graded to produce a gradual
surface drainage swale, covered with a 6-inch depth of topsoil, and that a vegetative cover was
established.

The plan sheet titled "Existing Plan," provided in Appendix B, Slough-Remedy Implementation,
provides a narrative as to how vegetation in the slough area was to be cleared, how the subgrade
was to be restricted from being disturbed, and how backfill and topsoil were to be placed. Plan
sheets simply labeled "6 of 7" and "7 of 7" (Appendix B, Slough-Remedy Implementation)
depict profile views of the slough and grade to which the slough was backfilled. It appears that
backfill of the slough began at Northing 4493 and ended at Northing 5700, as the two profiles at
Northings 5800 and 5832 do not depict backfill.

Segments of the slough identified as having soil (0 - 1-foot depth) contaminated with TCDD at
concentrations between 1 and 20 ppb are indicated by the referenced plan sheets to have been
backfilled. This is true for the slough reaches b'etween northings 4493 and 5700. However, the
reach of the slough adjacent to the Lagoon Area is located in areas characterized (Lagoon Area
1982 sampling) as contaminated with TCDD at concentrations of 1.2 and 2.3 ppb (Appendix B,
Lagoon). This reach of the Slough appears to have been addressed as part of the Lagoon Area,
and as such, is not reported to have been either excavated or backfilled with clean soil. However,
it is unknown how applicable the cited Lagoon Area sampling results are with respect to
representing Slough contamination in these areas.

Trench Area

The ROD states that: "Excavation of the Trench Area may result in migration of contaminants
located there as the excavation activities could disrupt the low permeability layer beneath the
subsite. For this reason, remediation of the Trench Area.. .will include: backfilling trench
depressions to original grade with gravel aggregate; installation of a 12-inch clay layer that will
extend 10-foot beyond trench boundaries; and subsequent installation of 12 inches of topsoil to
support a vegetative cover. In addition, a gravel drainage-interception trench will be installed
upgradient of the trench area..." The Syntex Implementation Plan states that stabilization
activities include backfill to existing depressions to the original grade with '/2-inch crushed stone,
placement and compaction of a native clay cover (min. 1-foot thickness), fine grading of the clay
cover to facilitate surface drainage, placement and compaction of a 1-foot topsoil, and'
establishment of vegetation on the trench cover.

The two Syntex plan sheets titled "Existing Trench Plan" (sheet 2 of 7) and "Final Trench Plan"
(sheet 3 of 7), Appendix B, Trench Area-Remedy Implementation, depict what appears to be the
implemented Trench Area remedy. Since these plan sheets are not labeled as "as-builts," it is not
clearly known whether these depict actual post-remedy implementation conditions. This being
1 the case, the plan sheets do depict sufficient clay and soil covers to be compliant with the
requirements of the ROD.


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Groundwater

Syntex describes how OU2 ROD requirements are to be implemented in the document titled
"OU2 Implementation Plan," dated in June 1995. The EPA issued an Administrative Order on
Consent (July 1997) which approved the 1995 Implementation Plan and also directed Syntex to
design and implement a removal action for polychlorinated biphenyls (PCBs) discovered during
utility-trenching operations.

In accordance with the implementation plan, Syntex performed the following activities:
installation of two floodplain monitoring wells at the north property boundary (MW-21 and
MW-22); installation of an upgradient monitoring well IS-6 and the monitoring of alluvium
monitoring wells for eight consecutive quarters. Syntex submitted a report to the EPA in 2000
which presented a risk assessment using the recently acquired data. This risk assessment has not.
been finalized and has not been reviewed as part of this FYR. Syntex has "voluntarily"
monitored four floodplain monitoring wells (IS-6, MW-6, MW-15A, and MW-21 R (a
replacement for MW-21)) on a semi-annual basis from 2003 through 2005; then on an annual
basis thereafter. Syntex has also "voluntarily" monitored four Trench Area wells (MW-11, -17, -
18, and -20) annually since August 2002.

Operation and Maintenance (O&M)

QUI - Soil

All covered/stabilized areas are reported to be maintained by the current site owner, BCP
Ingredients, with the exception of the trench area, which is maintained by Syntex. Visual
inspections are conducted quarterly and are repaired as necessary. Observations made during the
site inspection of August 14, 2012, verified that all covers were intact. However, due to drought
conditions, grasses exhibited stress and cover vegetation was thin in patches. Photographs of the
various sites are presented in Appendix F.

The scheduled quarterly inspections, by themselves, are not sufficiently frequent to identify
potential erosion resulting from single significant precipitation events. This is important at the
Trench Area where side slopes of the ridge/bluff appear to be greater than a 3:1 slope.

Inspections are recommended to be conducted after significant rainfalls to assess both erosion
and general drainage.

OU2 - Groundwater

Wellheads appeared to be sufficiently maintained. During the site inspection, Syntex
representatives stated that assessments are conducted at each sampled well to determine the
.amount of sediment accumulated within the well. However, records of these assessments have
not been provided.

V. Progress Since the Last Five-Year Review

Previous Five-Year Review Protectiveness Statement and Issues

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The protectiveness statement from the 2007 FYR for the Syntex Verona, Missouri Site
stated the following:

The remedy at the Site currently protects human health and the environment because all
caps are intact and well maintained, institutional controls are in place limiting site use to
industrial, and exposure pathways to groundwater are not complete. However, in order to
assure continued protectiveness in the long-term, monitoring requirements for the trench
area and facility should be established, the OU2 risk assessment should be finalized,
adequacy of current land use restriction should be re-evaluated, and the need for
restriction on groundwater use should be evaluated.

The 2007 FYR identified five issues and recommendations. Each recommendation and the
current status are discussed below.

Issue No. 1

Issue: Trench well monitoring and reporting requirements.

Recommendation: Evaluate Trench Area well monitoring and reporting requirements to ensure
they are sufficient to maintain long-term protectiveness at the site.

Party Responsible: Syntex and the EPA share responsibility for implementing recommended
actions. The EPA remains the lead oversight agency, and MDNR continues to be consulted and
involved in site activities.

Milestone Date: September 2008.

Action Taken and Outcome: No discernible action taken.

Issue No. 2

Issue: Finalization of OU2 Draft Risk Assessment and Long Term Groundwater Monitoring
Plan. .

Recommendations: Finalize draft risk assessment for OU2 and establish long term monitoring

qeeds with appropriate plans developed, approved and implemented.

Party Responsible: Syntex is responsible for compjeting the OU2 risk assessment. The EPA

Region 7 is responsible for identifying the monitoring need while Syntex is responsible for

developing and implementing the EPA approved groundwater monitoring plans.

Milestone Date: September 2008.

Action Taken and Outcome: No action taken.

Issue No. 3

Issue: Adequacy of institutional controls to prevent inappropriate land use.

Recommendation: Re-evaluate adequacy of current institutional controls to assure that
inappropriate land use does not occur.

Party Responsible: The EPA.

Milestone: September 2008.

Action Taken and Outcome: No discernible action taken.

Issue No. 4

Issue: Lack of institutional controls to prevent inappropriate land use.

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Recommendation: Evaluate the need for institutional controls restricting groundwater use.

Party Responsible: The EPA.

Milestone: September 2008.

Action Taken and Outcome: No discernible action taken.

Issue No. 5

Issue: Administrative Record could not be located at the local repository.

Recommendation: Locate the Administrative Record at the local repository.

Party Responsible: The EPA.

Milestone: September 2008.

Action Taken and Outcome: The Administrative Record was located at the Verona City Hall.
.Work Completed at the Site During the Review Period

QUI - Soil

Periodic inspections and maintenance have been conducted at all subsites. All inspections have
the objective of identifying the integrity of the inspected cover system. Maintenance activities
identified as having been conducted during the 2007 through 2012 time period include that prior
to the Spring 2011 MDNR site inspection, yellow lines were painted that identify where
excavation occurred in the Spill Area and the sealing of cracks in the pavement of the T-l Dike
Area prior to the August 14, 2012 inspection.

It is noted that no survey is reported as having been done of the Trench Area cover system to
establish baseline elevations that can be checked in later years to verify the absence of either
erosion and/or settling.

OU2 - Groundwater

Groundwater monitoring of the site's flood plain and Trench Area wells has been conducted
annually for the past 5-yrs. The last round of sampling was conducted during August 2012.

Five-Year Review Process

Administrative Components

The EPA Region 7 initiated the FYR in March 2012 and scheduled its completion for September
2012. The EPA review team was initially led by Robert Feild of Region 7, Remedial Project
Manager (RPM) for the Syntex Verona Superfund site, and also included the EPA site attorney
and contractor support provided by the U.S. Army Corps of Engineers, Kansas City District
(USACE). Laura Price, also with the EPA Region 7, assumed the team lead role in late July. The
USACE team was led by Daniel Mroz and included Charles Williams, geologist, and David
Daniel, risk assessor. Also part of the review team is the Missouri Department of Natural
Resources and the Missouri Department of Health and Senior Services. In March 2012 the EPA
held a scoping conference call with the review team to discuss the site and items of interest as
they related to the protectiveness of the remedy currently in place. A review schedule was
established that consisted of the following:

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•	Community notification;

•	Document review;

•	Data collection and review;

•	Site inspection;

•	Local interviews; and

•	Five-Year Review Report development and review.

Community Involvement

On September 12, 2012, a public notice was published in the Lawrence County Record
announcing the commencement of the Five-Year Review process for the Verona Syntex Site,
providing (The EPA RPM) contact information and inviting community participation. The press
notice is available in Appendix B. No public inquiries resulted from the advertisement
announcing the commencement of this Five-Year Review.

The Five-Year Review report will be made available to the public once it has been finalized.
Copies of this document will be placed in the designated public repository: Verona City Hall,
101 N. 3rd Street, Verona, Missouri. Upon completion of the FYR, a public notice will be placed
injthe Lawrence County Record to announce the availability of the final FYR report in the Site
document repository.

Document Review	-

Documents made available for this FYR were those present in the Administrative Record. This
FYR included a review of relevant, site-related documents including the RODs for operable units
1 and 2, various site characterization reports, remedial action reports and monitoring data. A
complete list of the documents reviewed can be found in Appendix A.

Applicable or Relevant and Appropriate Requirements (ARARs) Review

Section 121 (d)(2)(A) of CERCLA specifies that Superfund RAs must meet any federal
standards, requirements, criteria or limitations that are determined to be legally ARARs.
Applicable or Relevant and Appropriate Requirements are those standards, criteria or limitations
promulgated under federal or state law that specifically address a-hazardous substance, pollutant,
contaminant, RA, location or other circumstance at a CERCLA site.

The OU1 ROD identifies the following ARARs as having been identified and evaluated:

•	Resource Conservation and Recovery Act (RCRA)

•	Missouri Hazardous Waste Management Law

•	Federal and State Water Quality Criteria

•	Federal, State and County Transportation Requirements

This review has performed a limited ARAR review and has determined that the "global" ARARs
of RCRA and the Missouri Hazardous Waste Management Law are the two ARARs which most
comprehensively address current Syntex Verona CERCLA actions being conducted. Subject to

35


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1 ciial rev.tew, ii is Mte\v»i that 4<* 11-K Subpart F- Release* Ftotn Solid Waste Management
I !nit>, in the ARAR of most telexanct

The basic for determining a ptouvtive non-a-sMentwl u«c T.\".n.1 CI )15 action level has
changed. At the time ol the Ol11 R< )I) ,< ppb action level f<»i nortiesidential use was in plate.
In .'OUT a nonresidential PRC of (Jso ppf uas pmposcd. ! he chtonic oral Relet ence Dose issued
on l ehrtiary I 7, 20 L\ made this pn .posed RR( i obsolete helotc it was finalized 'This 2^,7,8-
I'C |>I> K11 > eat) he used witlt standard tisk equation-, and exposing fu tots to calculate that a 600
ppt ilsoxin level will be associated with a ha/aid quotient ol 1 tbi an industrial worker, this
calculation is piescnted m the iudustnal Suit Mippoitmg 1 able ol the Regional Seteening I exels
1 ahle (IT A. ?.01 ?), At or below this lex eh adxetse ttoitcattcri health effects are considered to he
exltctnely unhkeh. no maftct how long the exposure continues. ahox e this lex el. adxetse
tioiKanet health effects max occut

A To Ik' Cons.dered f II1C) xalue lot I 4 dtoxane dvteUcd in giotmdwater ts the Regional
Seteening Level f RSI ), R>.cenlls theie has been a heightened concent about 1,4-dtoxane, a

ehetnieal common!) used as a ptescsxatne hi I I.) asehlotoethaite. Based or. a 20|O change in
its oral eaneet slope faelot. the tap uatet RM lot 1 .4- dioxatie lias dtopped to 0.6? g'l.. I he
reporting limits for !,4-dtoxanc in groundwater samples have roufineh exceeded this RSI .
I stimateil conecntiations ol I >4~dto\anc ol up to 04 g 'I indicate that potential individual
excess lifetime eancci tisks max exceed 1x10 \ which is great ei than the hPA's tat gel cancer
rusk tatige, as tliteeled in the National Conungeuev Plan. Hu\ve\et, repotted levels max not be
accurate and this ehetnieal docs not appear to ha\ e been addtessed in any assessment of site lisk.

Table 15, .Summary of ARAR Changes







ARARs /TJM.'s

( run errs

AH ARU'TWX-

t'li.ini.'Pfl''

D toxin

20pph nun residfittial use
action level itt soil

600 ppt
industrial -
itoiicanet based
altet nate CM.

YES - more stringent

1,4 -Dioxane

L

None identified

f ).<>? ug/L

YES - more stringent

Risk Assessment Res iew

•\ site risk assessment has not been final t/ed lot the site due to ongoing rex sew of toxicity values
lot ,T3.7.S-'1CI)1). A ie\iew ol the existing dtaft risk assessment was not conducted. In I ebruatx
r3<»1 ?, a Reiereitce f)o%e was tinali/ed lot 3,l't'|)[) This Rfl) is stiflieiently low thai the
potential for adverse noncaneet health effects tna\ become the dominant factor in determining

1 (4 )1) cleanup lex els Site data chat at teri/ing the natute and extent of dioxin
contamination in soils is more than 15 years old I he site tisk assessment should be revised to;

•	Include more recent data;

•	incorporate changes in risk equations and exposure factors;

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• Incorporate the new RfD for 2,3,7,8-TCDD and any changes in toxicity values for other
COPCS.

Also, no ecological risk assessment appears to have been clone for this site. A Baseline
1'cological Risk Assessment l BFRAS should be planned for this site, nuking use of more recent
data gathered fur human health risk assessment.

Data Review

QUI — Soil

Reviewed soils data consists of characterization data collected in 1QS2 and 1985, and remedial
action verification data collected at the time ol'iemedy implementation (1 The 1982
characterization data was obtained from the FP \ report titled "Priority Pollutant and Dioxin
Data for the Syntex Area." Verona. Missmiti. April 11>S 1 (('FLIMHili Feolo^y & Environment,

1984). The 1985 characterization data was obtained hum plan sheets and liguies as found in the
EPA files separate from their associated it-ports; these are provided in Appendix B. Syntex
authored reports presenting eharaeten/ation data were not located in the reviewed file materials.
Remedy implementation verification data was obtained from the Syntex report, titled "Verona
Plant Sampling and Analysis Plan - Rex ised Remedial Alternatives Report (Second Revision),"
} March 1 l*XX. This review did not evaluate data quality.

Characterization data is presented in Section 3.5, Initial Response, while verification data is
presented in Section 4.2, Remedy Implementation. Additionally, each section references various
Appendices that provide excerpts from source documents.

The subject data is evaluated with respect to the OU1 ROD dioxin cleanup goal of 20 ppb, the
containment action level of between 1 and 20 ppb dioxin, and the recently derived noncaner
industrial use soil exposure level of 600 ppt dioxin that results in a hazard quotient of 1. It is also
noted that no data was reviewed which addressed the presence of other dioxin congeners in
addition to 2,3,7.8-tetrachlorodibenzo-p.

Grid Area

One round of Grid Area characterization sampling was conducted in 1985 in accordance with the
"Verona Plant Sampling and .Analysts Plan, Revised January 21, 1985." In general, a composite
sample was created from groupings of four adjacently located samples, collected across a surface
to 12-inch depth interval and located on a 100-foot x 100-foot grid pattern laid across the facility.
Each composite sample was analyzed for TCDD and 20 were additionally analyzed for
triehlorophenol (TCP), tetrachlorobenzene (TCB), and hexachlorophene (hex). The figure
provided in Appendix B, Grid Area-1985 Sampling, depicts these sample locations,

TCDD detections were reported in 19 composite samples, ranging in concentrations from ND to
3.10 ppb. Composite samples yielding TCDD detections are tabulated in Table 16.

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Table 16. Grid Are* "I < !«' ' < Composite Si

ietections)

;<» i

IfiT

J a l
o-.

lis

~2I4~

17f >

3,10

1.70 |c1m|)}

-• U'!

! ("!

t t 111
Oil

} f»<'l

0.18

The following conclusions are made from an evaluation of the reviewed data;

•	Grid Area cluiiaclciuotiuii ttknutki an estimated iUUiluO-.sLjtuic feci (ft l of s»uii
contaminated willi HDD at coikdilution-, e\ccedtit;<, the MK! ppt RSI and an climated
,"»4njH>{»-112 evecedm;:. 0 "Mi pph I ('DM 1 hese estimate^ ate based upon a sample grid
spacing of 100-lt and sampler comported across a sui face to lAinch depth

•	Nu soil sample tc-uks exceeded the .?'• ppb cleanup goat

•	An estimated 1	' oi sui taee soil h chatacicn/ed as eontainiiij.: K 1)1) at

concentrations ranytng ttom lo \ I') pph 1 lu>c concentrations at other subsites
trigs>eted the ROD lequhcmciit fo< plaeenient ot 1 toot of "cover" followed by actions to
establish and maintain \euetation

« (irid Area eharactei i/ation result- nu\ ha\e underestimated surface soil ]'(1)1)

concentrations. Suriaee deposition ts the mode In which dioxin contamination in the Grid
Area would have oeeutred Since dioxin is not siraiificaistK uiohile and would be
expected to remain at oi neat the susface, a composite created aetoss an intenal
representing more than "suriaee soil" would likely dilute suriaee contamination thai may
be present, (arid Area samples are repiesentaine of the soil strata from the sin face to a
L—in depth.

Bum Area

C 'haraeteri/ation sampling conducted m ll'S2 \telded data desetibed as has mg been generated
from the analysis of samples composited across a 3-foot depth interval that included 2-foot of
backfill material (ptesumabk clean) fhiee of the foni sampled SO-foot \ H-foot quadtants
produced composite samples with reported total dioxin lesults exceeding 600 ppi (Quadrant 180
at 24 ppb; Quadrant 181 at 1.30 ppb; and, Quadrant 182 at «'» .Id pph.

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Additional characterization sampling conducted in 1985 focused on Quadrant No. 180, which
had previously generated the 24 ppb total dioxin result. Four borings were located within the
quadrant, and each was sampled at 1.5-foot intervals to a depth of 6-foot and analyzed for
TCDD. Table 4 provides sample results. Overall results ranged from ND to 27.00 ppb TCDD,
with three of the four boring locations yielding sample intervals substantially exceeding the 600
ppt RSL. One sample, derived from the 1.5 to 3.0-foot interval, yielded a result of 27.00 ppb
TCDD.

No remedial excavation took place at the Burn Area. Syntex implemented verification sampling
of the 50-ft x 100-ft Burn Area before any remedial action excavation was started at this subsite.
Verification sampling (surface to 2-inch depth) yielded a 0.57 ppb TCDD soil concentration at
the 95 percent confidence level.

The following conclusions are made from an evaluation of the reviewed data:

•	Verification sampling indicates that surface soil within the boundaries of the Burn Area
have a TCDD concentration of 0.57 ppb. This is less than the 600 ppt RSL for industrial
use.

•	Subsurface soil TCDD concentrations exceeding the 20 ppb ROD cleanup goal, as -
identified by characterization sampling, were not addressed by the implemented remedy.

•	Characterization results are expected to have underestimated dioxin concentrations by
virtue of the backfill material (presumed clean) being included in the composite sample
interval.

•	The plan sheet depicting the verification sampling data does not tie-in the sampling
points or Burn Area borders to any geo-spatial reference point - no survey data is .
reported.

Spill Area

A single round of characterization sampling was conducted in 1985 (Section 3.5). In summary,
eight composite samples, each representing a surface to 6-inch depth interval and a 20-foot x 80-
foot rectangular area, were analyzed for TCDD. The results ranged from ND to 5.90 ppb TCDD.
The reviewed "Syntex Implementation Plan," July 29, 1988, was written prior to the remedy
being implemented at the Spill Area. The EPA approved a closure plan for the Spill Area in
correspondence dated October 6, 1995, that called for leaving in place existing gravefand
placing an additional four to six-inch nominal stone layer over the gravel base, which then would
be topped with either asphalt or concrete. Documentation of the implementation of the approved ¦
plan was not part of the reviewed documents; however, the Spill Area is now paved with
asphaltic concrete.

Additional dioxin soil contamination was discovered in March 1997 located near the former T-l
dike in the Spill Area. The EPA Remedial Action Report, dated September 1998, reports that
soils contaminated with dioxin above 20 ppb were excavated and transported to a commercial
incinerator for thermal treatment. The excavated area is reported to have been backfilled with a
minimum of 1-foot of clean fill dirt and capped with an asphaltic cover. Completion of this

39


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.action occurred in December 1997. Other than the cited EPA report, no other documentation of
this cleanup was reviewed.

PCBs were also discovered in April 1997 at the Spill Area near a small electrical building during
trenching operations related to burying power lines. The soil was reported to contain PCBs at
1,000 ppm. A removal action was initiated in August 1997 in accordance with an EPA issued
Removal Action Memorandum dated July 17, 1997. This removal action was completed in
conjunction with the aforementioned dioxin removal (EPA, 1998).

The following conclusions are made from an evaluation of the reviewed data:

•	Spill Area characterization yielded no sample results exceeding the 20 ppb cleanup goal;
however, during later utility excavation work, dioxin contaminated soil above 20 ppb was
found and removed.

i

•	Characterization data did not define either the horizontal or vertical extent of soil
containing dioxin greater than 600 ppt. It is not known if surface soil containing TCDD at
concentrations exceeding 600 ppt extend beyond the borders of the asphalt cap.

•	Plan sheets depicting the geo-spatial relationship of the asphalt cap to the area subjected
to TCDD characterization were not found during this review. A meets and bounds survey
of the Spill Area characterized as having soil TCDD concentrations greater than 600 ppt
should be accomplished.

Irrieation Area

Characterization sampling was conducted in 1982 on a 150-foot x 250-foot area identified as the
Irrigation Area. This sampling identified the southeast portion of the Irrigation Area
(approximate 85-foot x 75-foot) as having a composite soil dioxin result of 29.0 ppb while all
other results.were less than 0.44 ppb dioxin. Subsequent sampling conducted in 1985 focused on
the area that yielded the 29.0 ppb composite sample result. The 1985 sampling results were all
less than 20 ppb TCDD, however, three results exceeded the 600 ppt TCDD RSL (1.60 ppb, 1.50
ppb, 0.68 ppb). Additionally, a composite sample collected to represent a minimum 10-foot wide
border along the Irrigation Area's eastern perimeter composite sample results of 27.20 ppb and
7.40 ppb TCDD (duplicate analysis). All samples were collected across a 12-inch interval.

No remedial excavation of soils occurred. Syntex implemented pre-excavation verification
sampling of the 60-foot x 75-foot southeast corner of the Irrigation Area to determine if surface
soils contained TCDD at a concentration exceeding the 20 ppb cleanup goal. The verification
sampling (surface to 2-inch depth) yielded a 9.1 ppb TCDD soil concentration at the 95 percent
confidence level.

The Syntex Implementation Plan states that due to surface runoff ponding in this subsite area,
topsoil was placed into the area such that final grade was at elevation 1255-ff. This fill is stated
to have been traffic compacted and subsequently established with vegetation.

The following conclusions are made from an evaluation of the reviewed data:

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•	No verification sampling was conducted on the majority of the originally defined
Irrigation Area: 150-foot x 250-foot (37,500-ft2) Irrigation Area vs. the 60-foot x 75-foot
(4,500-ftr) on which the verification sampling protocol was implemented. The total
Irrigation Area was defined as having received dioxin contaminated water, yet only a
portion of the: Irrigation Area was sampled per the stipulated verification sampling
protocol. In accordance with the ROD, the entire Irrigation Area subsite should have been
tested per the verification sampling protocol.

•	Data used to demonstrate closure of approximately 33,000-ft2 of the Irrigation Area likely
underestimated the dioxin concentration at the surface due to a 12-inch sample interval
having been used as opposed to the 2-inch sample interval of the verification sampling
protocol.	;

•	The border along the southeast perimeter of the Irrigation Area is indicated to have
TCDD soil concentrations potentially exceeding the 20 ppb dioxin cleanup goal.

Duplicate analysis of the composite sampje representing this area yielded results of 27.20
ppb and 7.40 ppb TCDD.

-	The vertical and horizontal extent of this contamination was not defined;

-	This border area was not subjected to any verification sampling.	v

•	Fill, in the form of topsoil, is reported (Syntex, 1988) to have been placed to elevation
1255-feet, traffic compacted, and subsequently established with vegetation. However,
reviewed information did not identify what area this covered and whether this action is
compliant with the ROD requirement to provide a 1-foot depth of cover over areas with
dioxin between 1 and 20 ppb.

•	The pre-excavation verification sampling result of 9.1 ppb TCDD at the 95 percent
confidence level (applicable to the southeast 60-foot x 75-foot corner) exceeds the 600
ppt TCDD RSL.

Lagoon Area

Characterization sampling was conducted in 1982 on a 360-foot x 300-foot area identified as the
Lagoon Area. This sampling identified three 60-foot x 120-foot subareas that yielded composite
samples exceeding the 20 ppb cleanup goal (340 ppb, 110 ppb, and 26 ppb). Follow-up sampling
conducted in 1985 focused upon the three 60-foot x 120-foot subareas previously mentioned plus
two others that had yielded 1982 sampling composite samples of 9.00 ppb and 13.00 ppb total
dioxin. The 1985 sampling yielded the following significant results: two composite samples,
each collected across the surface to 1.5-foot depth interval, having TCDD concentrations of 56
ppb and 1046 ppb; one composite sample collected'across the 1.5-foot to 3.0-foot interval having
a TCDD concentration of 30.6 ppb; and, remaining composite samples (collected up to a 6-foot
depth) having reported TCDD concentrations less than the cleanup goal. The samples exceeding
the cleanup goal were from two adjacently located 60-foot x 120-foot subareas.

Pre-excavation verification sampling is stated to have been conducted (Syntex, 1988); however,
results of this sampling were not found to have been reported in the Syntex Implementation Plan.
Excavation is reported to have proceeded based upon the results of pre-excavation sampling.
Interim verification sampling results (if conducted) were also not reported. Final verification
sampling results are provided on the plan sheet titled "Lagoon Area - Final Verification
Sampling Areas and Excavation Extents (sheet 1 of 1)," located in Appendix B, Lagoon-Remedy

41


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Implementation. All areas subjected to verification sampling, including 10-foot wide borders
adjacent to excavated areas, yielded results between 1.0 and 20 ppb TCDD.

The following conclusions are made from an evaluation of the reviewed data:

•	Verification data ranges from 1.04 to 19.08 ppb TCDD — all tested areas are thus subject
to the ROD requirement of 1 -foot of cover and establishment of vegetation.

Nonexcavated and perimeter areas with surface TCDD concentrations between 1.0 and
20 ppb are reported to have not received placement of 1-foot of cover material. Reviewed
records do not clearly indicate whether excavated areas received placement of 1-foot of
cover when backfilled.

•	Final excavation depths were undeterminable from information reported in the Syntex
Implementation Plan. The referenced plan sheet identifies excavation depths as being
either greater than 12-inches, less than 12-inches, or from 2 to 6-inches.

•	Reviewed data does not identify whether contamination exceeding the cleanup goal, at
depth, was excavated. Characterization data identifies TCDD soil contamination of up to
1,046 ppb to a depth of 1.5-foot and 30.6 ppb at a depth of 3.0-foot. The plan sheet
depicting excavation depths only states that excavation occurred to a depth greater than

12-inches in the area where these hot samples were collected.

•	Verification data indicates that post-remedial action residual soil contamination exceeds
the 600 ppt RSL at all areas of the Lagoon.

•	Non-excavated Lagoon Area subareas, exceeding the 600 ppt dioxin RSL, total
approximately 16,800-ft2. These subareas were not reported to have received placement
of additional topsoil.

•	A 10-foot swath of perimeter soil adjacent to excavated areas was sampled per the
verification sampling protocol. Results of this sampling range from 8.25 ppb to 19.08 ppb
TCDD at the 95 percent confidence limit.

-	The extent of surface soil contaminated greater than the RSL extending radially
from the perimeter of the Lagoon Area boundary is undefined.

-	The vertical extent of soil contaminated greater than the RSL is undefined.

Slough Area

The slough is reported to have been backfilled between Northings 4493 and 5700 in order to
cover areas suspected of containing TCDD at concentrations between 1 and 20 ppb. Five
composite samples yielded TCDD concentrations exceeding 1 ppb between Northings 4600 and
5500. It is noted that the slough's reach adjacent to the Lagoon Area is depicted in an area
indicated to be contaminated with TCDD at concentrations of 2.3 and 1.2 ppb. This slough reach
appears to have been addressed as part of the Lagoon Area, and as such, was not backfilled since
it did not contain TCDD exceeding 20 ppb.

The following conclusions are made from an evaluation of the reviewed data:

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•	The Slough reach between Northings 4443 and 5700 are reported to have received
backfill and topsoil that covered soil contaminated with TCDD at concentrations between
1 and 20 ppb.

•	The Slough reach adjacent to the Lagoon Area did not have backfill or topsoil placed.
This portion of the Slough begins at Northing 4500. Lagoon verification sampling
yielded a TCDD concentration of 19.08 ppb in this general area (Lagoon Area - Final
Verification Sampling Areas and Excavation Extents, sheet 1 of 1).

•	The rational for characterization sampling being stopped at the 5800 Northing is not
provided. The dioxin verification sampling protocol was not applied to the Slough Area
and the rational for this is not provided.

•	At 5800 Northing, a characterization sample yielded a result of 0.45 ppb TCDD. It is not
known what dioxin soil concentrations are past the 5800 Northing.

Trench Area

The ROD required the Trench Area to be capped in-place with a 12-in clay cap extended 10-ft
beyond trench boundaries, placement of topsoil to a depth of 12-in, and installation of a
groundwater cut-off trench. Reviewed plan sheets (Existing Trench Plan, sheet 2 of 7; and, Final
Trench Plan, sheet 3 of 7) depict the Trench Area as being compliant with ROD requirements.
However, it is not known if these plan sheets represent as-built conditions or are simply planning
documents. They are also not dated.

The following conclusions are made from an evaluation of the reviewed data/information:

•	If the referenced plan sheets depict as-built conditions, the implemented remedial action
was compliant with ROD requirements.

•	Follow-on inspections conducted by Syntex do not include periodic resurveying of the
capped area. Such surveys would be capable of indicating if erosion and/or settlement
were occurring.

•	No records were reviewed that addressed the effectiveness of the employed interceptor
trench system at keeping shallow groundwater below the bottom of each of the five
trenches.

«

•	A record of a meets and bounds survey of the Trench Area was not present in reviewed
records.

OU2 - Groundwater

Data covering the entire duration of the project was reviewed; however, emphasis has been
placed upon data generated from the last five years of monitoring. Groundwater data generated
during the period covered by this FYR was generated through the voluntary sampling of four
shallow floodplain alluvium monitoring wells and fdtir trench monitoring wells. Syntex has been
sampling these eight wells voluntarily since 2003.

Floodplain

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In accordance with the OU2 ROD, monitoring of floodplain wells for eight consecutive quarters
was initiated November 1997. The following monitoring wells constituted the sampled well
network: MW-4, MW-5, MW-7, MW-9, MW-15, MW-15A, MW-15B, MW-16, MW-16B,
MW-21, and MW-22. All monitoring wells monitor the shallow alluvium except the following:
MW-15, bedrock; MW-15B, alluvial-bedrock contact; MW-16, bedrock; MW-16B, alluvial-
bedrock contact. Data for the four consecutive quarters beginning with November 1997 was
available for review. In summary, sample results from these four quarters contained the
following VOCs (high conc., well no.): Chlorobenzene (310 (ig/L, MW-6), methylene chloride
(12.0 ng/L, MW-15B), ethylbenzene (10 (ig/L, MW-6), 1,4-dichlorobenzene (12 fig/L, MW-5),

toluene (42 fig/L, MW-6), and xylenes (88 (ig/L, MW-6). Monitoring wells providing samples
containing a minimum of one VOC detection were MW-4, MW-5, MW-6, MW-9, MW-15A,
and MW-15B. It is noted that reporting limits for 1,4-dioxane were either 500 (ig/L or 1,000
' (ig/L for this duration.

1 j

Voluntary sampling of one upgradient shallow alluvium floodplain monitoring well (IS-6) and
three downgradient shallow alluvium monitoring wells (MW-6, MW-15A, and MW-21/21R) has
been ongoing since 2003; semi-annually from 2003 to 2006 and annually since 2006. Summary
tables of this data are provided in Appendix C, Floodplain Wells-Data (2003-2011).

Annual voluntary sampling conducted from 2003 to 2006 had detections above quantitation
limits for chlorobenzene (52 to 90 ppb, all at MW-6); ethylbenzene (5.9 and 6.9 ppb, both at
MW-6), 1,4-dichlrobenzene (8.6 to 16 ppb, all at MW-6), toluene (99.7 to 39 ppb, all at MW-6),
xylenes (8.5 to 59 ppb, all at MW-6), and dioxin (4.4pg/L, at MW-6). Additionally, the following
were detected at estimated concentrations: acetone (3.9 ppb), methylene chloride (3.2 ppb),
ethylbenzene (1.2 to 3 ppb, all at MW-6), 1,4-dioxane (57ppb and 67 ppb), 1,4-dichlorobenzene
(0.66 ppb at MW-15A), toluene (0.65 to 1.2 ppb), xylenes (8.7 at MW-6), bis(2-
ethylhexyl)phthalate (6.3 to 25 ppb), and dioxin (4.1 pg/L). Monitoring well MW-6 was the only
well with samples having analytes at concentrations greater than quantitation limits.

Annual voluntary sampling conducted from 2007 to 2011 had detections above quantitation
limits for chlorobenzene (25 to 77 ppb, all at MW-6), 1,4-dichlorobenzene (5.1 to 5.7 ppb, all at
MW-6), toluene (6.1 ppb at MW-6), and xylenes (14 ppb at MW-6). Additionally, the following
were detected at estimated concentrations: methylene chloride (2.8 ppb at MW IS-6), 1.4-
dioxane (35 to 94 ppb), ethylbenzene (0.33 to 1.4 ppb, all at MW-6), 1,4-dichlorobenzene (10
ppb at MW-6), toluene (0.2 to 3.1 ppb), xylenes (0.45 to 1.6 ppb, all at MW-6), bis(2-
ethylhexyl)phthalate (2.6 to 9.6 ppb), and 1,3-dichlorobenzene (1.1 and 1.5 ppb at MW-6).
Monitoring well MW-6 remained the well with the most detections. No dioxin detections were
reported in the 5-year period from 2007 through 2011.

Only one dioxin detection has been reportedjn samples collected from the voluntarily sanipled
monitoring wells and that was at monitoring well MW-6 with a concentration of 4.4 pg/L in
February 2005.

The following conclusions are made from an evaluation of the reviewed data/information:

44


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•	It is suspected that an inappropriate analytical method is used for the analyte 1,4-dioxane.
The method detection limit was not identified for analyses conducted during the
voluntary sampling period. However, for the sampling conducted during 1997-1998, the
reporting limit was typically identified as 500 jig/L. This analyte requires the use of a
modified analytical method to obtain appropriate quantitation limits. 1,4-dioxane is both
highly soluble and mobile and is viewed by the EPA as an emerging contaminant (EPA,
2009).

•	Monitoring since 2003 has been conducted of only the shallow alluvium. The rational for
this was not provided in the reviewed documents. It may be appropriate to monitor a
broader cross-section of the alluvial aquifer in light of the VOCs previously detected at
the alluvial-bedrock contact at MW-15B.

Trench

Trench Area wells have been monitored under different programs and frequencies since 1991.
Quarterly sampling appears to have been conducted of select wells from January 1991 through
April 1992; May and August 1993; February, May and November 1994; and March 1995.

Annual sampling commenced in 2000 of wells MW-11, MW-17, MW-18, and MW-20.

Summary data tables are provided in Appendix C, Trench Wells-Data.

Early monitoring (1991-1995) was compromised due tq the high number of wells reported to
have been either dry or having insufficient recharge. From January 1991 to March 1995, out of
54 discrete sample events, a total of 30 events reported dry wells and an additional five where
recharge could not produce sufficient sample volumes. Summary data tables identify
dichloromethane as the one VOC detected above its 5 |ig/L MCL. Other VOCs detected were
methylene chloride and acetone. No TCDD was detected, although a number of monitoring wells
could not produce sufficient sample volume for TCDD analysis. Of interest is the detection of
acetone in the 3,000 to 4,000 |i|ig/L range at monitoring well MW-11 in January and April 1991
and then not being sampled for the next four sampling events. Monitoring well MW-11 is
screened across the contact between fresh and weathered bedrock (residuum) at the highest
elevation of all Trench Area wells (Radian, 1992).

Annual sampling conducted from 2000 to 2006 had detections above quantitation limits for
acetone (5 ppb), chlorobenzene (14 to 58 ppb, all at MW-17), 1,4-dichlorobenzene (5 to 8.3 ppb,
all at MW-17), bis (2-ethylhexyl)phthalate (11 to 68 ppb), and TCDD (14 and 15 pg/L). Several
other VOCs and SVOCs (including additional hits of TCDD) were detected below quantitation
limits and/or were associated with samples where the method blank was contaminated: acetone
(6 to 23 ppb); methylene chloride (3.3 ppb); 1,4-dioxane (25 ppb); ethylbenzene (0.5 ppb);
toluene (0.31 to 1.2 ppb); bis (2-ethylhexyl)phthalate (7.2 to 34 ppb); and TCDD (2.3 to 6.5
pg/L). The detection limit for TCDD is reported as being 0.64 to 12 pg/L for the period 2003-
2011. Monitoring well MW-17 was the only monitoring well that consistently had VOC
detections (7/7 events) as well as two TCDD detections. Compounds detected above quantitation
limits at monitoring well MW-17 were: chlorobenzene had seven detects ranging from 14-58
Hg/L; acetone had one detect at 11 |ig/L; 1,4-dichlorobenzene had six detects from 5 to 8.3 |J.g/L;
bis(2-ethylhexyl)phthalate had two detects of 40 and 68 (Ag/L; and TCDD had two detects of 14
1

45


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and 15 ng/L. Monitoring wells MW-11 and MW-20 each had one event that had either a VOC
and/or SVOC detection greater than quantitation limits.

Annual monitoring during the period 2007 through 2011 was conducted at monitoring wells
MW-11, MW-17, MW-18, and MW-20. Two analytes were reported at concentrations greater
than quantitation limits: chlorobenzene and 1,4-dichlorobenzene. These analytes were present at
concentrations exceeding quantitation limits only at monitoring well MW-17. Chlorobenzene
was present at such levels in all collected samples from monitoring well MW-17 and its
concentration ranged from 16 ppb to 67 ppb. 1,4-dichlorobenzene was present above quantitation
limits at monitoring well MW-17 in three of five samples, and its concentration was 5.6 ppb in
all three samples; it was also present at estimated concentrations of 3.4 and 3.8 ppb in the other
two samples collected across the five-year period at MW-17. The following analytes were also
reported as estimated concentrations at one or more of the sampled wells: acetone (8.9 to 17
ppb); ethylbenzene (0.22 to 0.68 ppb); 1,4-dichlorobenzene (0.19 ppb); toluene (0.23 to 0.66
ppb); and TCDD (5.8 to 18 pg/L). Monitoring well MW-17 was the most contaminated well of
the Trench Area during this period - chlorobenzene and 1,4-dichlorobenzene were present at
concentrations exceeding quantitation limits; while acetone, ethylbenzene, toluene, 1,4-
dichlorobenzene, and TCDD (5.8 to 18 pg/L) were also reported at estimated concentrations.
TCDD was only detected at monitoring well MW-17 during this five-year period. Tabulated
results are provided in Appendix C, Trench Area Wells - Data.

Issues/concerns:

•	Data acquired from monitoring well MW-17 may be indicative that a release from the
Trench Area has occurred.

•	The quantitation limits are not identified for the analyte 1,4-dioxane. It is assumed that
the analytical method used is not appropriate for this compound as has been the case for
the floodplain alluvium groundwater monitoring program.

•	It is difficult to ascertain if the screened intervals and placement of the monitoring wells
are correctly placed to intercept potential releases from the Trench Area. This is a
complex hydrogeologic setting as compared to the alluvial wells of the floodplain.

•	. Static water level measurement data has not been presented. If available, it should be

provided. If not being taken, water level measurements should be part of the monitoring
program.

Site Inspection

The site inspection was performed on August 14, 2012. The EPA Region 7 representatives were:
Laura Price and Kelly Schumacher; USACE representatives were: Daniel Mroz, David R.

Daniel, and Chuck Williams, all with the Kansas City District; Syntex was represented by their
environmental consultant, "Foth," whom provided: Scott Barton and Bob Kick; MDNR was
represented by: Don Van Dyke and Evan Kifer; Missouri Department of Health and Senior
Services (DHSS) was represented by Dennis Wambuguh and Elizabeth Semkiw, BCP was
represented by Terry Anderson and Jon Barrows.

A walking tour of the following sites occurred: PCB Cleanup Area, Irrigation Area, Spill Area,
Lagoon Area and Trench Area. The Slough Area was viewed from the northeast corner of the

46


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Lagoon Area. It is noted that the PCB cleanup area site is not addressed by either the OU1 or
OU2 RODs; however, it is addressed by the 1997 Administrative Order. At each area, Scott
Barton described the implemented remedy and answered questions. None of the sites exhibited
signs of erosion - no erosion channels/rills were observed. It was generally observed that due to
three plus weeks of drought conditions and extreme heat preceding this site visit, all vegetative
covers exhibited stressed vegetatation, which included patches of bare ground and dead grass.

The following summarizes findings of the inspections performed at the following sub-sites.
PCB Cleanup Area

The PCB cleanup area is beneath an asphaltic pavement. The exact, location of the cleanup was
not identified; however, this area is located between various industrial buildings and is
completely paved. The observed pavement did not exhibit surface cracks. No photos were taken
of this area; however, the pavement depicted in the Spill Area photos is representative of the
appearance of the PCB Cleanup Area pavement.

Irrigation Area

The Irrigation Area is located almost adjacent to and southwest of the Spill Area. Photos 1
through 4 depict this area. This site is in a nonpaved area of the facility. Its perimeter is marked
with a wire cable, upon which Restricted Area signs are hung (Photo 4). A rectangular area
within the marked area is elevated perhaps a foot (no measurement taken) above the adjacent
ground surface in a manner resembling a plateau. Photo 1 depicts the transition from the elevated
area to the adjacent ground surface. Vegetation is distressed and patches of bare soil are present.

Spill Area

The spill area is located northwest of the PCB cleanup area and northeast of the Irrigation Area.
It also is capped with asphaltic pavement. Photos 5 through 11 depict this area. The Spill Area is
defined by yellow lines painted atop the pavement and is also defined by survey monuments
(photo 9) which are embedded in the pavement. The observed pavement appeared intact with no
evident cracks.

Lagoon Area

The Lagoon Area is located in the north central portion of the facility and was observed from
along its eastern and northern perimeter. Photos 12 through 15 depict this area. The perimeter of
the area was marked with a metal cable hung with warning signs, as similarly done at other sites.
Vegetation was present, although distressed. Areas of dead grass and patches of bare soil were
observed.	J

Slough Area

The Slough Area is located north of the Lagoon Area and was observed from the Lagoon Area's •
northern perimeter. Photos 16 and 17 depict this area. The Slough appeared to be well vegetated.

Trench Area

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The Trench Area is located on the west side of the Spring River, upon a bluff overlooking the
production areas of the facility. Upon arrival at the Trench Area, a local private citizen was on
the Trench Area spreading suspected deer feed. Mr. Scott Barton had a discussion with the
individual, presumably to reinforce the concept that this is a restricted area. Photos 18 through 25
depict the area. Vegetation, although distressed, was present. The photos depict examples of
thinned vegetation due to drought conditions, which allowed for patches of bare soil to be
present. No evidence of erosion was observed. Side slopes of the ridgeline upon which the trench
is situated appeared to be intact with no evidence of erosion. The area's perimeter is marked with
a metal cable upon which is hung signage stating that it is a restricted area - authorized
employees only.

Burn Area

The Burn Area is on the south western side of the Syntex Site, relatively close to the Spring
River's east bank. Photos 26-28 depict the area. The perimeter of this is also marked with metal
cable upon which warning signage is hung. The area was observed to have an uneven grade.
Ponding of water appeared to be possible. Vegetation is present, although distressed and thin in
many spots, allowing bare soil to exist. No surface erosion was evident, as might be expected
due to the flat grade.

Grid Area

The Grid Area is essentially the remainder of the nonpaved areas of the facility and was observed
in passing as the inspection team drove from the Burn Area back to the production area of the
facility. The Grid Area looked to be well vegetated.

Interviews

During the site visit, discussions were primarily had with Mr. Scott Barton of Foth (consultants
to Syntex). Questions were asked while the inspection was being conducted. The following
summarizes discussions had with Scott Barton during the site inspection:

•	QUESTION: Reviewed plan sheets indicate that a flood protection dike exists, is this
accurate?

RESPONSE: a flood protection dike was constructed during the 1990s. Scott Barton
pointed out that monitoring wells in the floodplain (outside areas protected by the dike)
have risers that extend well above the ground surface - to a height where samplers need
to use step ladders to conduct sampling. It was also pointed out that bollards are located
upstream to minimize the likelihood of objects hitting the protective riser during flood
events.

•	QUESTION: Have any groundwater wells not currently being sampled been abandoned?
RESPONSE: Mr. Barton stated that all 24 wells are in place and usable for monitoring.

•	QUESTION: What were the locations of the private wells that had been sampled and
were they sampled for 1,4-dioxane?

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- RESPONSE: No answer was provided other than it would need to be researched.

•	QUESTION: Were monitoring wells MW-12R and MW-13R completed to the same
depths and screened at the same intervals as the original wells?

RESPONSE: Mr. Barton stated that the answer would have to be researched.

•	QUESTION: Based upon reviewed records, it did not appear that all surface soils
identified as containing TCDD at between 1 and 20 ppb was covered with 1 -foot of soil -
how was the selected "containment" remedy implemented?

RESPONSE: Mr. Barton stated that records would have to be reviewed to determine
how the selected remedy was actually implemented.

•	QUESTION: Were the lagoons ever directly connected to the slough?

RESPONSE: Mr. Barton responded that there had not been direct discharges to the
Slough; however, there may have been overtopping, but not purposeful direct discharges.

•	QUESTION: A general question was asked about required dioxin sample volumes.

RESPONSE: Mr. Barton responded by stating that current volume requirements are
something a bit less than a liter. Currently, sampled trench wells are done so with a
bailer. Due to low yields, a well is typically bailed dry and revisited the next day and
sampled.

Institutional Controls

The OU1 ROD does not specify the use of Institutional Control of the Syntex Verona site. However, the
Syntex Verona site was placed on the Missouri Registry of Confirmed Abandoned or Uncontrolled
Hazardous Waste Disposal Sites on January 1, 1984. The Registry is a listing of sites that contain
hazardous waste which are subject to Missouri law and regulation which provide for institutional control
of the listed sites. Institutional controls include: deed notification of contamination, annual inspection
conducted by MDNR, notice to buyer, change of use review, notice to the State if property is sold,
cleanup and removal from the Registry, and public information about site location, classification of threat,
contaminants, health concerns public and private drinking water wells, and geology (MDNR, 2011).
Registry listing places the following use restriction on a property: site use may not change substantially
without the written approval of the director of MDNR; a change of use is considered substantial if it may
result in the spread of contamination, increases human exposure to hazardous materials, increases adverse
environmental impacts, or makes potential remedial actions to correct problems at the site more difficult;
the seller must notify the buyer of the condition prior to site sale; changes of ownership must be reported
to the department within 30 days after the change (MDNR, 2011).

Syntex requested in 2002 that the Trench Area be separately registered from the Syntex Site located east
of the Spring River. This was accomplished in 2002. The registry report states that Syntex has installed

49


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survey markers around the site as required by

interest at the Site.

Table 17 lists the ICs associated with areas of

Table 17. IC Summary Table

. U s f.iUori

lur in thi' -

Uri, isiiHi : Parcei(s)

MMU

Ground

Water

No

¦JlllttilfttBi

Not Applicable Not: Applicable





1 ict>i h

Soil No

! .u'liitv t.is! >•!



Npf Hi/ Urn r



No

Yes



Risk assessment teed on
gw data acquired prior to
1993 determines that risk
is within the acceptable
range.

Covenant restricting land
use is described in
Paragraph 28 of Exhibit il
attached to the General
Warranty Deed for this
property.

VII. Technical Assessment

(.)nc>tion A: Is the remedy functioning as intended by the decision, documents?
GUI Soil

No. The implemented remedy is not fusuliunimi ns intended by the OU1 ROD. The
following issues directly affect the functionality of the Ol11 ROD selected remedies:

•	The ROi) i equiremem So excavate and thermally treat soil exceeding 20 ppb dioxin was
not implemented at all areas where characterization data indicate subsurface soil contains
greater than 20 ppb 1 (1)1):

•	Backfilling with clean soil is reported to have only been conducted at areas that were
excavated, resulting in known areas of uncapped surface soil with dioxin, between 1 and
20 ppb;

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•	The implemented stabilization remedy has resulted in an estimated 3.5 acres of"un-
contained" surface soil indicated by characterization data to be potentially contaminated
between 0.98 and 3.10 ppb dioxin; and,

•	Historic groundwater monitoring of the Trench Area has resulted in detections of
hazardous waste constituents known to be present in the trenches. This is indicative of a
Trench Area release; however, detections and concentrations have been inconsistent. The
hydrogeology of the Trench Area is complex and the existing well network (location;
screened intervals) should be re-evaluated to determine its adequacy.

OU2 Groundwater

No. The implemented remedy is not functioning as intended by the OU2 ROD. Groundwater
monitoring data of a quality sufficient for use in a risk assessment is/has not been generated:

•	1,4-dioxane results are J-coded estimated concentrations, due likely to an inappropriate
analytical method being used;

•	Monitoring of only the shallow floodplain alluvium has occurred since 2003. It is noted
that floodplain monitoring well MW-15B, screened at the alluvium-bedrock contact, had
consistent VOC detections in the four quarters of data available for review (Nov 1997;
-Feb, May, Aug 1998).	*

Question B: Are the exposure assumptions. Toxicity Data. Cleanup Levels, and Remedial Action
Objectives CRAOs) Used at the Time of Remedy Selection Still Valid?

No, toxicity data for dioxin has changed. Additionally, 1,4-dioxane is an analyte which has been
monitored for, per the OU2 ROD, but which has not been fully addressed in site risk. The EPA
identified 1,4-dioxane as an emerging contaminant in 2009 (EPA 505-F-09-006, Sep. 2009) and
the characterization of this chemical at this site has yet to be adequately completed.

Changes in Standards and To-Be-Considered Criteria

The EPA's recommended PRGs for dioxins in soil at CERCLA remedial sites have been 1 part
per billion (ppb) (or 1,000 ppt (parts per trillion)) for residential exposure and 5 to 20 ppb for
commercial/industrial exposures (EPA, 1998). Draft interim PRGs for dioxin in soil of 72 ppt for
residential land uses and 950 ppt for commercial/industrial land uses were proposed in 2009
(EPA, 2009a). These values are no longer needed as a result of the EPA's selection of a final
noncancer Reference Dose (RfD) for 2,3,7,8-TCDD (US EPA, 2012a). Using this new RfD and
standard US EPA exposure and toxicity values and equations, Regional Screening Levels (RSLs)
for the residential and industrial exposure scenarios have been calculated and posted (EPA,
2012b).

RSLs are classified as To-Be-Considered (TBC) criteria. RSLs are screening values used to
determine whether chemicals pose sufficient risks to be included in risk assessments and are not
intended to be used as cleanup goals for sites. However, since they use the standard risk
equations to determine intakes with default exposure parameters, which for many sites will not
be changed, and current toxicity values to back calculate soil, groundwater and air concentrations

51


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associated with target levels of risks, the RSLs are generally equal to cleanup goals that would be
calculated for sites in the absence of adjustments for site-specific data.

RSLs for 2,3,7,8-TCDD based on a cancer risk of lxlO"6 are 4.5 ppt for residential exposures and
18 ppt for industrial exposures. These soil screening levels, associated with a cancer risk of
lxlO"6 may be close to ambient background levels for dioxin in soil.

The new RfD as a final value is an appropriate basis for the calculation of risks based on a
hazard quotient of 1. In addition to the values recommended for screening levels (i.e., the more
conservative of the RSL value based on cancer or noncaner effects), the RSL table calculates
levels that would be associated with 10'6 cancer risks and HQs of 1 for each chemical with
appropriate toxicity values in several Supporting Tables. The calculations in these tables used the
EPA's standard risk equations, exposure and toxicity factor. The RSL Industrial Soil Supporting
Table shows that a 600 ppt dioxin concentration is associated with an HQ of 1 for industrial
worker exposures. This level is higher than the cancer risk-based RSL at 10"6, but still acceptable
because the cancer risks associated with these values fall within the acceptable range of cancer
risk endpoints of 10"6 to 10"4. The cancer risk associated with the 600 ppt industrial soil level is
3.3x10 .

The noncancer industrial level of 600 ppt (based on default criteria) is sufficiently lower than the
cleanup goal of 20 ppb, that it is possible that some areas of the Syntex site may have residual
dioxin levels that would exceed the new value. With a site cleanup level of 20 ppb and levels in
soils as high as 19 ppb have been reported, these data are over fifteen years old and may no
longer be representative of dioxin concentrations.

Changes in Exposure Pathways

This review identifies a new understanding of how OU1 ROD remedy implementation occurred,
which in turn affects the protectiveness of the remedy actually implemented. The "containment"
remedy was not applied to a minimum of 16,800-ft2 of surface soil documented by verification
sampling to contain dioxin at concentrations between 1 and 20 ppb at the 95 percent confidence
level - no 1-ft of cover soil was reported to have been placed over such soils. Implementation of
the "stabilization" remedy has resulted in an estimated 200,000-ft2 between 0.60 and 3.10 ppb.
Additionally, undefined areas adjacent to remediated areas are indicated to contain TCDD at
concentrations exceeding 1.0 ppb. The surface soil exposure pathway is potentially complete and
likely encompasses an area greater than previously considered.

0	There are no current or planned changes in land use. The site's use remains industrial and the

population of Verona has remained relatively unchanged between the last two censuses. The
surface soil route of exposure, as explained above, appears to potentially be a complete pathway.
Observations during the site visit indicate that much of the contaminated area has very limited
human contact. Consideration of more realistic exposure assumptions than the standard industrial
scenario might be appropriate for a new risk assessment of the site.

No new contaminants or sources were identified as part of this FYR. However, it has been noted
that an increase in the cancer slope factor of 1,4-dioxane has resulted in a lowering of screening

52


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levels that have made the historical analytical quantitation limits inadequate for risk assessment..
Upon changing analytical methods to one more appropriate, it is possible that 1,4-dioxane may
become a confirmed site contaminant.'

Changes in Toxicity and Other Contaminant Characteristics

On February 17, 2012, the US EPA released its final noncaner dioxin reassessment and
published an oral noncaner toxicity value, or reference dose (RfD), of 7x10"10 mg/kg/day for
dioxin in the EPA's Integrated Risk Information System. The RfD is based on studies that show
decreased sperm count and motility in men exposed to 2,3,7,8-TCDD as boys (Mocarelli, 2008)
and increased thyroid stimulating hormone (TSH) in neonates (Baccarrelli, 2008). This dioxin
RfD was approved for immediate use at Superfund sites to ensure protection of human health.
Prior to this release, cleanup goals based on the cancer risk at 10"6 associated with dioxin had
been lower than those based on noncaner health effects. The cancer risks associated with RSLs
calculated on the basis of adverse noncaner health effects are greater than 1 xlO'6, but fall within
the acceptable range of cancer risk endpoints of 10~6 to 10"4.

The terms 2,3,7,8-TCDD, TCDD, dioxin, and total dioxins are used interchangeably in many of
the site documents. 2,3,7,8-TCDD is the main dioxin congener produced as a byproduct in the
synthesis of both 2,4,5-T and hexachlorophene and is considered the most toxic of the dioxin
compounds. However, it is not clear whether the concentrations being reported in site documents
represent a conversion of all congener results to 2,3,7,8-rTCDD toxic equivalents. (TEQ) or
2,3,7,8-TCDD results only. Given the variation in reporting, the concentrations reported are not
certain values since they may or may not contain contributions from the other polychlorinated
dioxin/dibenzofuran congeners.

A review was conducted which compared the concentrations of.the maximum non-dioxin soil
contaminants listed in Table 3 against non-residential use soil RSLs. All soil concentrations were
within the acceptable risk range of 10"6 to 10"4.

Changes in Risk Assessment Methods

In 1988, when the 1988 ROD for Syntex soils was issued, baseline risk assessments (BLRAs)
were conducted under an older guidance, the Superfund Public Health Evaluation Manual (EPA,
1986). When the Risk Assessment Guidance for Superfund (RAGS) Human Health Evaluation
Manual (Part A) came out in 1989, there were substantial changes in the approach to risk
assessment (EPA, 1989). Further changes in risk assessment methodology were made later in
RAGS Parts E (EPA, 2004) and F (EPA, 2009), addressing risk assessment of dermal and
inhalation exposures, respectively. Current risk assessment methodology should be used when
addressing the follow-up actions and recommendations of this five-year review report.

Progress Towards Meeting Remedial Action Objectives

The OU1 and"OU2 RODs do not identify remedial action objectives. However, the 2007 FYR
reports that the 1997 FYR identifies the following presumptive remedial action objectives:

•	Reduce exposure to contaminated soils at the site, specifically dioxin contamination.

•	Reduce contamination of on-site groundwater by addressing contaminated soils.

•	Reduce exposure to materials and equipment contaminated with dioxin.

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•	Reduce exposure to dioxin in fish in the Spring River.

•	Assess the groundwater contamination to assure protectiveness.

The goal of reducing exposure to dioxin contaminated soils has not been achieved as designed by
the OU1 ROD. There appears to be a lack of soil cover being applied to surface soils exceeding 1
ppb TCDD leaving acreage of surface soil in the "Grid Area" exceeding 1 ppb TCDD, which
would lessen the effectiveness at which exposures will be prevented and would allow for an
increased potential of off-site migration of sediment containing dioxin as compared to having
had all such soil covered with 1 -ft cover as specified in the OU1 ROD.

A risk assessment on groundwater contamination has not been completed. Prior to completing
the risk assessment, existing groundwater data needs to be verified that it is of sufficient quality
to perform the required risk assessment. For example, the cancer slope factor for 1,4-dioxane has
increased so that levels below the quantitation limit for the method used for analyzing 1,4-
dioxane may pose unacceptable risks.

The results of fish sampling conducted from 1988 through 1992 were interpreted by the EPA as
demonstrating the ".. .decline of dioxin levels in fish between 1988 and 1992, after the
implementation of OU1..." (OU2 ROD, p. 13). Fish collection/tissue sampling for dioxin content
was not required after 1992. For purposes of this five year review, fish tissue data was not
reviewed based upon conclusions stated in the OU2 ROD.

1.1. Question C: Has Any Other Information Come to Light That Could
Call Into Question the Protectiveness of the Remedy?

t

QUI Remedy Implementation

Yes, this review does identify a new understanding of how OU1 ROD remedy implementation occurred,
which in turn affects the protectiveness of the implemented remedy. The "containment" remedy was not
applied to a minimum of 16,800-ft2 of surface soil documented by verification sampling to contain dioxin
at concentrations between 1 and 20 ppb at the 95 percent confidence level. Implementation of the
"stabilization" remedy resulted in an estimated 200,000-fr potentially containing between 0.98 and 3.10
ppb dioxin. Additionally, undefined areas adjacent to remediated areas are indicated to potentially contain
dioxin at concentrations exceeding 1.0 ppb.

Ecological Risks

No information was found to indicate that ecological risks posed by dioxins in soil were addressed.
A study was done to investigate possible impacts of dioxin migrating to a nearby surface water
stream via groundwater or surface water runoff to the extent of determining whether fish tissue
might bioaccumulate dioxins to levels that might affect human health. Protectiveness of the remedy
includes protection of ecological receptors. Without an assessment of ecological risks, it is not
possible to verify the protectiveness of the remedy.

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Natural Disaster Impacts

There have been no natural disasters at the site in the last five years. Although the site is located
within the 100-yr flood plain of the Spring River, it is located within 3-miles of its headwaters,
reducing the likelihood of flooding. County record's were checked with regard to flood warnings
over the past five years and none were issued.

1.2. Technical Assessment Summary

The technical assessment has identified issues for each Operable Unit that brings into question the
protectiveness of the implemented remedy. Regarding OU1, the assessment identifies a recently issued
dioxin RfD which results in a non-residential level of 600 ppt in soil (based on default criteria) associated
with an HQ of 1 and a 10"5 cancer risk. This is significantly lower than the 20 ppb soil cleanup action
level stipulated in the OU1 ROD. The OU1 implemented remedy has left an estimated 3.5 acres of non-
contained surface soil with dioxin potentially between 1 and 20 ppb - these verification and
characterization data are, however, over fifteen years old and may no longer be representative . It also
does not include an undefined quantity of surface soil that was indicated as also exceeding 1 ppb dioxin.
Groundwater monitoring of the Trench Area needs to use an analyte specific methodology for the analysis
of 1,4-dioxane; currently used methods result in quantitation limits of 500 ng/L versus a cancer-based tap
water RSL of 0.67 (ig/L . A reevaluation of the Trench Area monitoring network's ability to detect
potential Trench Area releases is recommended due to the complex hydrogeologic setting of this sub-site.
Sampling to update soil concentrations and a risk assessment incorporating changes in methods, exposure
and toxicity factors is needed to evaluate current risks at the site. A Baseline Ecological Risk Assessment
is also needed since ecological risks at the site have never been specifically addressed. The nai've
assumption that remedies based on protection of human health are adequate for protection of ecological
receptors is likely false for dioxin.

Concerning OU2, several issues are identified that also bring into question the protectiveness of the
remedy. Monitoring for 1,4-dioxane needs to use an analyte specific methodology; currently used
methods result in quantitation limits of 500 (ig/L versus a need to screen to less than 0.67 |ag/L. All
detections of 1,4-dioxane have been J-coded as being below quantitation limits. The floodplain alluvium
has only been monitored for the past 10-years in its upper 15-ft. The adequacy of this limited monitoring
network is questioned as VOCs have previously been detected in a monitoring well screened at the .
alluvium-bedrock contact (MW-15B).


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2. Issues

Table 18 summarizes the current issues for the Syntex Verona Site,

TaMe; 18 Current Issues with the Verona Syntex Site

is*

test,#

01111 Utilizing the newly established RfD and standard
non-residential use EPA risk equations and exposure
factors, a level of 600 parts per trillion (ppt) dioxin is
shown tu he associated with a hazard quotient of 1 for
non-residential exposure to dioxin contaminated soil,.

Afi§& Currant

PfOttdtVWfMMI
j(Y>> of Wo)

Yes

Affects !• ufiir®
P r of e c t i v enR •» s

(Yes or No)

Yes

OU1; Subsurface soil characterized as exceeding 20 ppb
ckivn was not addressed by the implemented remedy (as

No

Yes

q U ^ 0 n t *' |*0 ed y 1*0 port ^ 1 ^|y ^ ^ ^ | 0 n ^ y

sites that were excavated. This results i<< both  imt-H ;h-H
undefined areas of non-contained surface ;.<»s! with in

potentially exceeding §00 ppt.

Yes

Yes

" " " 	 " ' ~ ' " "" 		~~~

OU1: Based on historical data collected from the site,
approximately 3.5 acres of surface soil may contain levels
of dioxin that exceed EPA's Industrial soil screening level

based on the new dioxin toxicity value.

Yes

Yes

OU1: The complexity of the hydrogeologic setting of the
Trench Area suggests thai potential releases may not be
intercepted by the existing well network.

Yes

Yes

OU1: Secondary structural features of the residuum may
re su't 11 .^acceptably high rates of potential contaminant
transport

Yes

Yes

OU1 & 2. An ecological risk assessment has not been
performed.

No

No

OU2; i»4-Dioxarte has not been analyzed with
appropriate methodology.

Yes

Yes

OU2 monitoring of the deep alluvium has not or cu-red in
the past 10-yrs. Historic samples from the a>iuv.un-
bedrock contact have had VOC contaminants.

Yes

Yes

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3. Recommendations and Follow-up Actions

Table 19 summarizes issues and provides recommendations »->hn «lu> iik* i-U i ik
Table 18. Recommendations to Address Current issues at the Syrttex Verona Site

Oil 1: ROD 20 ppb

Conduct stlc



EPA

09/2014

Yes



soil action level vs.

characterization and



MDNR







600 ppt level derived
from new RID.

human health risk

,lssv SM5R Mi











CMJl: Subsurface

1 \akut, ml nt.M-.l |h

V-, 'Hc\



09/2014

N't'

Yes

soil > 20 ppb dioxin

WHS )U>! 4,Wiessed.

Micl, s, ;ii



' N







(Sin Non coiii,

( "h.tHH t'MI-'e Otllleni

M ntc\

t p \

09/2014

Yes

Yes

suiiaot suils exi't

sft>" vMliill!] it! , i \ ain.IK



MONK







ppt dioxin remain
				

!>-l tO . U1I. '11 ,11!''
POk't.'t.ti itll ,!<
K . CjlK'! S











OU1 • s>

cima. teu.v,itiu :ii sit,'



1 !'A



Yes

Yes

tenx-dv in

.oiuliUonv evaluate si v



MDNR

09/2014





Mil tact vii ( * *•

iisks; del, i»uhh











actcs) iihlu aH J t>>

u llctlici a.Milt. 0 p|H

ni'i- iifikis -w.i

1H CC»s i(S











I lie Uill'.'l:. well

*ss 10, s





Yes



lias <.cl»plc\

HClWs'lk Hist,ill VU IK ,!>>



MONK

09/2014





luduwolocv

apjiiojii uU











UUI. Scv->ii.l,ti\

Re-evaluate the

"s\ lit. \

1 !'\



No



structural ieatures ¦ »t

ckuMii'! (•>1 • oiiUiot"



mpvk







the KskltlUllS ! 1 K-IK'h

11ciK'h Aioa wastes in











<\n\il m,»> temlt til

li;:hi of 1 lis.* ;.'ctli\sii at











uiKietxptabk luvh

ektue. tciistus i-! ihc











t<»tr> ot" potential

uiitlci 1) tug. !U4tU ul.











contaminant













transput!













< )U 1 ?: Kolofica!

Conduct HI K.\ ysme

Syntex

EPA



W-

Yes

usks kne no! iKtii

cm icat inc'hi hK



MDNR

09/2014



















1,44'it.vine

to\ieit\ lias ch myt'd,
u ndcrint- used

Revise Groundwater

Sampling and Analysis
Plan

Syntex

1 PA

Ml INK

i i M

Yes

Yes

quaittiiatsori lmitt>

iiMtle^uate













< >U2 in>mUoun\i ot

j!Iu\nil hedicck

Begin monitoring
alluvial-bedrock contac

Ssniev

i PA

\m\k

09/2014

Yt>

Yes

contact lu> tsot
occuneJ in she past

prior to assessing
current site risk











!(>->ts.

associated with gw.











58


-------
4. Protectiveness Statements

QUI - Soil

The protectiveness of the implemented remedy cannot be determined until further information is obtained.
Surface soils containing dioxin at greater than 1 ppb may not have been consistently contained in
accordance with selected remedy Alternative 3A:

•	soils identified by verification sampling as containing dioxin between 1 and 20 ppb at the 95
percent confidence level may not have been contained;

•	' the lateral extent of soils demonstrated by verification sampling to contain dioxin at

concentrations greater than 1 ppb was not defined; and,

•	implementation of the "stabilization" remedy appears to have allowed an estimated 3.5 acres of
surface soil characterized as containing dioxin at concentrations greater than 1 ppb to remain
uncontained.

•	The ROD requirement to excavate and thermally treat soil exceeding 20 ppb dioxin was not
implemented at all areas where characterization data indicate subsurface soil contains greater than

. 20 ppb TCDD

The new RfD for 2,3,7,8-TCDD leads to a 600 ppt level being associated with a HQ of 1, which is
substantially lower than the past 20 ppb cleanup level. However, data for dioxin are over fifteen years old
or missing and may not include congeners other than 2,3,7,8-TCDD. Thus, these data may not be
representative of concentrations remaining in the soil. Affected areas should be re-sampled to characterize
the current extent of dioxin contamination. When these data are obtained, a human health risk assessment
using current methodology and toxicity values should be performed to support a decision on the
protectiveness of the remedy.

The protectiveness of the implemented remedy for the OU1 Trench Area cannot be determined until
further information is obtained regarding the Trench Area groundwater monitoring program. Due to an
increase in the cancer potency of 1,4-dioxane, the quantitation limits used for previous analysis of that
compound are too high to assure that cancer risks falls in the acceptable range. Further information will
be obtained by taking the following actions:

•	Conducting 1,4-dioxane analysis by newer methods with appropriate quantitation limits

•	Conducting a comprehensive reevaluation of the Trench Area well network in order to verify that
groundwater gradients can be established and that screened intervals are correctly located with
respect to intercepting potential Trench Area releases

I

•	Correcting any deficiencies found in the network.

These actions would provide a monitoring program more likely to intercept potential releases from the
Trench Area.

There appears to have been no assessment of risks to ecological receptors made for this site. The
assumption that human health-based cleanup levels were adequately protective for ecological receptors is

59


-------
incorrect. For health risks other than cancer, 2,3,7,8-TCDD is generally more toxic to many, animals than
to man. Similarly, an assumption that the containment measures taken in certain relatively small areas that
would represent a fraction of forage areas would be* adequately protective may not be correct depending
on concentrations in stabilized areas where dioxin would be readily available to ecological receptors. It is
recommended that a Baseline Ecological Risk Assessment should be conducted using the data that will be
collected to support the human health risk assessment.

OU2 - Groundwater

The protectiveness of the remedy at OU2 cannot be determined until further information is obtained.
Further information will be obtained by taking the following actions:

•	Initiating groundwater sampling from a monitoring network that encompasses more than the
uppermost 15-feet of alluvial aquifer;

•	Utilizing an appropriate analytical method for 1,4-dioxane; and

•	Conducting a risk assessment utilizing data of sufficient quality.

A revised protectiveness statement is anticipated to be made via an addendum by September 30, 2015, if
the recommendations are implemented with sufficient time to allow a minimum of six quarters of
groundwater data to be collected.

Site-Wide	1

Overall, the protectiveness of the implemented remedies cannot be determined until further information is
obtained. Much of the data on this site is either over 15 years old or missing and may therefore not be
representative of current concentrations. The new RfD for 2,3,7,8-TCDD indicates that a protective level
for site workers may be as low as 600 ppt. Groundwater cancer risks cannot be properly evaluated with
existing data because the quantitation limits on the analyses performed for 1,4-dioxane are now too high
due to an increase in the cancer potency of 1,4-dioxane. Toxicity factors for a number of other analytes
may also have changed since the last risk assessments. Finally, no assessments of ecological risks appear
to have been made at this site. Further information will be obtained by taking the following actions:
resampling areas potentially affected by dioxin in soil, conducting an ecological risk assessment,
conducting 1,4-dioxane analysis by newer methods with appropriate quantitation limits in the trench area
and groundwater, re-evaluating the trench area well network, and conducting an updated human health
risk assessment for groundwater and soils. A revised protectiveness statement is anticipated to be made
via an addendum by September 30, 2015.

60


-------
5. Next Review

This is a statutory Site that requires ongoing FYRs as long as waste is left on site that does not allow for
unrestricted use and unlimited exposure. Due to the deferred determination of protectiveness, a FYR
addendum due date is September 30, 2015.

61


-------
[This page intentionally left blank.]

62


-------
Figures


-------
[This page intentionally left blank.]


-------
Lmmmm 2220

/• s; 0 «

J

CD ^

Fann Road 1140





JJHifRwi.

V,^*--** 1#-'"
/

Spiny 812008TANA, fee R«i" 0i/JW6r

% jj^>\ ' fM0f Rc

'•' V\

* -¦* '' ^

. v



I

2

i

i!

• nf

FIGURE!: SITE LOCATION


-------
[This page intentionally left blank,]


-------

-------
[This page intentionally left blank.]


-------
Appendix A: List of Documents Reviewed

And

References


-------
[This page is intentionally blank]


-------
List of Documents Reviewed

Barks et al., 1983. Geology, Water Movement and Sediment Characteristics of the Spring River Upstream
from LA Russell. Missouri Department of Natural Resources, Geological Survey and Resource
Assessment Division, Rolla, MO. 1983.

CH2M/Hill, 1984. Priority Pollutant and Dioxin Data for the Syntex Area, Verona, Missouri. April.

Ecology & Environment, undated. Field Investigations of Uncontrolled Hazardous Waste Sites-Task
Report to the E.P.A; Figure titled: Burn Area Sample Results, Syntex Compliance Monitoring
Verona, MO.

Ecology & Environment, undated. Field Investigations of Uncontrolled Hazardous Waste Sites-Task
Report to the E.P.A; Figure titled: Irrigation Area Sample Results Syntex Compliance
Monitoring Verona, MO.	N

Ecology & Environment, undated. Field Investigations of Uncontrolled Hazardous Waste Sites - Task
Report to the E.P.A; Figure titled: Spill Area Sample Results Syntex Compliance Monitoring
Verona, MO.

Ecology & Environment, undated. Field Investigations of Uncontrolled Hazardous Waste Sites-Task
Report to the E.P.A; Figure titled: Trench Area Sample Results Syntex Compliance Monitoring
Verona, MO.

Ecology & Environment, undated. Field Investigations of Uncontrolled Hazardous Waste Sites - Task
Report to the E.P.A; Figure titled: Grid Area Sample Results Syntex Compliance Monitoring
Verona, MO.

Foth, 2011. Letter Re: Project Number 00FG 1239.00 - OU2 Voluntary Groundwater Monitoring Report,
Syntex Facility Superfund Site, Verona, MO (EPA ID #MOD007452I54). December.

Jacobs Engineering Group, 1987. Figure titled: Dioxin Surface Contamination. April.

Jacobs Engineering Group, 1987. Figure titled: Syntex Agribusiness Verona Facility Lagoon Area. April.

Jacobs Engineering Group, 1987. Figure titled: Syntex Agribusiness Verona Facility Slough Area. April.

Jacobs Engineering Group, 1987. Figure titled: Syntex Agribusiness Verona Facility Trench Area. April.

Radian, 1992. Groundwater Remedial Investigation. August.

Syntex Agribusiness, Inc, 1982. Sampling and Testing Protocol. June.

/

Syntex Agribusiness, Inc, 1985. Verona Plant Sampling and Analysis Plan. January.

Syntex Agribusiness, Inc, 1988. Verona Plant Sampling and Analysis Plan - Revised Remedial
Alternatives Report (Second Revision). March.


-------
Syntex Agribusiness, Inc, 1988. Implementation Plan, Volume 1, Introduction - Appendix 6. July.

Syntex Agribusiness, Inc, i991. Implementation Plan Groundwater Report. September.

Syntex Agribusiness, Inc., 1995. Operable Unit No. 2 Implementation Plan. June.

TetraTech, 1989. Activity Report. October.

U.S. Environmental Protection Agency, 1982. Preliminary Investigation of Spring River Basin. July.

U.S. Environmental.Protection Agency, 1982. Consent Order Regarding Monitoring, Testing, Analyses
and Reporting. August.

U.S. Environmental Protection Agency, 1983. Consent Agreement and Order. September.

U.S. Environmental Protection Agency, 1985. Letter Re: Verona Plant Sampling and Analysis Plan.
February, 28, 1985.

U. S. Environmental Protection Agency, 1988. Proposed Plan for Final Management of Dioxin
Contaminated Soil and Equipment, Syntex, Verona. March.

\

U.S. Environmental Protection Agency, 1988. Record of Decision for Final Management of Dioxin
Contaminated Soil and Equipment at Syntex Agribusiness, Inc. Verona, Missouri. April.

U.S. Environmental Protection Agency, 1993. Record of Decision Ground Water Operable Unit #2,
Syntex Agribusiness, Inc. Verona, Missouri. April.

U.S. Environmental Protection Agency, 1995. Letter, RE: Syntex Facility - Verona, Closure of the Spill
Area. October.

U.S. Environmental Protection Agency, 1997. Administrative Order on Consent for Response Actions.
July.

U.S. Environmental Protection Agency, 1998. Remedial Action Report, Syntex Facility Remedial Action
Operable Unit 1 Verona, Missouri. September.

U.S. Environmental Protection Agency, 2009. Fact Sheet: Emerging Contaminant - 1,4-Dioxane. EPA
505-F-09-006. September.

U.S. Environmental Protection Agency, undated. Figure titled: Verona Trench Area Total Dioxin
Analyses. Superfund Records bar code no. 40028964.


-------
List of References

Baccarelli, A; Giacomini, SM; Corbetta, C; Landi, MT; Bonzini, M; Consonni, D; Grillo, P; Patterson,
DG; Pesatori, AC; Bertazzi, PA, 2008. "Neonatal thyroid function in Seveso 25 years after maternal
exposure to dioxin." PLoS Medicine 5/7. p. e 161. .

Mocarelli, P; Gerthoux, PM; Patterson, DG, Jr; Miiani, S; Limonata, G; Bertona, M; Signorini, S;
Tramacere, P; Colombo, L; Crespi, C; Brambilla, P; Sarto, C; Carreri, V; Sampson, EJ; Turner, WE;
Needham, LL, 2008. "Dioxin exposure, from infancy through puberty, produces endocrine disruption and
affects human semen quality." Environmental Health Perspectives 116: pp. 70-77.

United States Environmental Protection Agency, 1986. "Superfund Public Health Evaluation Manual."
EPA 540/1-86/060.

United States Environmental Protection Agency, 1989, "Risk Assessment Guidance for Superfund,
Volume I: Human Health Evaluation Manual (Part A)."

United States Environmental Protection Agency, 1998. "Approach for Addressing Dioxin jn Soil at
CERCLA and RCRA Sites." OSWER Directive 9200.4-26.	;

1

USEPA, 2001. Comprehensive Five-Year Review Guidance, Office of Emergency and Remedial
Response (5204G), EPA 540-R-01-007, OSWER No. 9355.7-03B-P.

)

United States Environmental Protection Agency, 2004. "Risk Assessment Guidance for Superfund,
Volume 1: Human Health Evaluation Manual (Part E, Supplemental Guidance for Dermal Risk
Assessment." OSWER Directive 9285.7-02EP.

United States Environmental Protection Agency, 2009a. "Draft Recommended Interim Preliminary
Remediation Goals for Dioxin in Soil at CERCLA and RCRA Sites."

United States Environmental Protection Agency, 2009b. "Risk Assessment Guidance for Superfund,
Volume I: Human Health Evaluation Manual (Part F, Supplemental Guidance for Inhalation Risk
Assessment." OSWER Directive 9285.7-82.

United States Environmental Protection Agency, 2012a. "EPA's Reanalysis of Key Issues Related to
Dioxin Toxicity and Response to NSA Comments, Volume 1." EPA/600/R-10/038F.

United States Environmental Protection Agency, 2012b. "Regional Screening Table At
http://www.epa.gov/reg3liwmd/risk/human/rb-concentration_table/Generic_Tables/index.htm.


-------
[This page is intentionally blank]


-------
Appendix B: 0U1 Textura! References


-------
[This page is intentionally blank]


-------
0U1 Soils
Burn Area - Remedy Implementation


-------

-------
50 II.

Attaebnent n

fiistiti§ nn

¦i

No, 18! J a0 ,g0
U ppl ( 24 pPb*

O ©

He, 182

4.1 ppl

No. I 19
0.19 ppb'

distill lilt Post

BURN AREA

Total Oioxin Analyses
By Ccpillary Electron Capture Gas Chfociatography

Bfsoils in Paris per Billion fppij
Collected for Water Content
Based on Certified Standard
'AVERAGE OF DUPLICATE ANALYSES


-------

-------
OU1 Soils
Burn Area -1985 Sampling


-------
I

FELO NVESTtOATIONS OF UNCOrtTHOUCD
HAZARDOUS MMTE 8TTGS
nu Ifinir t« m M4.

1 Burn Area Sample Results
Syntex Compliance Monitoring
Verona, MO

im. R-07-8408-23B

(MMiOii. »»»»«»

«ii*i mm
iKp^rrii

• r.

i«r.«

o

NO

;ip£) <4*1***

eowpo»tt©

«ft	In p«b



1.6-i« M0 J

ntirRsr?iii

r.tr.S.WC.i:J»

rrs?.<*nai

J***



9

1 B«.<

• CPA eomp o »11 e

'— 1 fW'tfW'—-

1	TCOO

'«$> I- H - 81»»yip fothal at
I Dt • I: h y 11 u r • n ft n •

•••rTrj.itffrro

Fan Sri*

i 18T.1.

i ''WT^K»5«
ffcBttiai"



' /
/



r^acTl

w.*r,yi

1«M

1 ¦	¦¦ |





1940.4
O

fig# r«M(M

3



4«M	|

a oo 4	|

¦ti\

i .;•:

o T
S *


-------

-------


¦ - •' •

¦';r



•»3



	-J 6.-CT ' ,

«¦

1

i,* - s







!.." •"•.¦.i'l?

¦ d. •••' "*?•. <



IV- '



NO-

^ -

''Vj-'r'•'•



'6.(7' .

*%;•••: • v•' •> • •:.••• r-..:*•:

NS^





. ^



U

'U.v-

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BURN .AREA

dtoxtn

SYNTEX AGR1;BU$I NESS
VERONA FACILITY

i ft,

IB*

gfifs

i

! C ; :

I $£.:;
I fcfr....



•.^V;v


-------
0U1 Soils
Bum Area -1982 Sampling


-------
;•••	.'. : --.r'-	• -r.

V?rificot;3TT
Sor,pl;ng Lir-i.ts J
CSe'e Inset).

: N

1-9 Dike

('

E-jii.diii'g V — 11

¦60''

:c

K

J.« _d®.
. . i„



"J'

.j	=

Not to Scale

v.v."

-¦j j

Ul i

T3 = 9.1

SiEL-758	2.b

759	7.0

760	.3.6

SYNTEX^'agp

K.K'MVnT " .f-CfA. 'VS:'JV ff.CV

Drawn by
RLW

Scale: r=?CT

¦13RIGATIGN
AREA

Check'sci By:

File None>

V-ISRTGA

July £5),

Sheet
i of 1


-------
I

0U1 Soils
Spray Irrigation -1985 Sampling


-------
Attachment 0



yt



V

150 II.

Ho. 1006
0,23 ppb

No. 100S
0.14 ppb

No. 1003
0.17 ppb*

Ho, 1004
0.27 ppb

Ko. 1002
0.44 ppb

1 X

* J

' Ho. JlOOl*
- —29 ppir "
X 1 x

*	1 *

*	1

X A

NEPACCO" SPRAY-IRRIGATION AREA

Tots! Dioxin Analyses
By Capillary Electron Capture Gas Chromatography

Results in Pans per Billion (ppb)
Corrected lor Water Content
Based on Certified Standard

'AVERAGE OF DUPLICATE ANALYSES


-------
TABLE 3

IRRIGATED AREA DIOXIN RESULTS
SAMPLES COLLECTED SEPTEMBER, 1982

Map



Syn t ex

Synt ex

EPA

Des ignat ibn

EPA #

D e 8 i g n a

t i on b

Data (ppb)

Data (ppb)

¦ A

AN3613

IA 1-8

1001

29.0

	

¦ B

AN3814

1A 9-16

1002

0.44

	

« C

A H 3 8 1 5

IA 17-24

1003

0. 17

	: —

¦ D

AN3816

IA 25-32

1004

0.27

0.26 

-C*

1

00

1006

0.23

	

~ G

AN38H

IA 1-24,

	

	

3.4





33-48







(U) * Less Than The Detection Limit


-------
BORING LOG	( Terracon Consultants, inc

Composite Sample: Irrigation Area	Verona Phase II

v°lqr	"i '982	Job No. 2*25 ,A	41-43 0-1	SILT, Little Clay, Trace

Sand, Brown


-------
qvjl Soite

, 98S Sample

Sp\«Wea


-------


MS**





FCLO MVESTIQATI0N8 OF UNCONTROLLED
HAZAROOUSMMTC 8ITE8

»*»« MPOIT TO TNI I.M.

»««' irrigation Area

Sample Results
Syntex Compliance
Monitoring
Verona t MO
o_r>'7_n2inn_'j"?n

ecology ud environment, Inc.

•NAM! IIIMM,





LEGEND

o" Sample location
C 11- Syntex- composite

		sample

iEPA composite
sample
ND contaminate not
detected
D duplicate analysis
T triplicate analysis
J value is estimated
because quality
control criteria
were not met

v hufrTH "reap ABOCMai-ITtB"

&-1 iTsfl ilBMUJ

"TO— awb lite MMp

__"£jyr

AKA5W0*

.19^4-°-°^o

HWl too
T-i »to~

19 8,3 0 02 !q

"1

r

i

; o

19 5, 3 00 JT©

I V

31953002

wwr

tab

O-l

Q.tB

1-2 NO

/

19 5.200 lt®^

/



195,3004 ^

19 5.200 3~tc

/

. jl9 5. 3 006

/

/

. /

195*30061o	195,20^ |©

_ _

19 5.3 0 07!©

ffi"

' 19 5 . 2 0 0 5 iO I




-------
OU1 Soils

Irrigation Area - Remedy Implementation


-------
V-- App*»oftR*attf f**Wp ioro tioa

EQ	'cofof Sar>pi»nfl po*»t

All *»jnbe^« *rtt co*po«rted
mio o«e ?a*c«e ror v*ty*i«-
Mr*-* ?anp4tng tocatjc"? rviy b»

proro*e«< =n -a#* eijpjl** «#-e
not ccn»»<*#M Any o*Nm*
ioc«i4.io** •*'. be per the
fecoQ«t"»eo rsr^»t(v-oi by CPA,

T3 - 0.57
2EL-746 0.3

747	0.3

748	0.5

# SWEX1^

IWwn by RLV

scoie. t# « lo*

July 23. 1988

BURN AREA

LPA's 93*
Confidence I eve'
Sanpttog Protocol

Checked by.

Sheet 1 of I


-------
(

0U1 Soils

Spray irrigation-1982 Sampling


-------
HMMDOWMITinU
im iwht n m mx

Spill Area Sample
Results
Syntex Compliance
Monitoring
Veronaa HO'
t-»j. R-07-840B-23B

ud i

Scale

0 10 20FT

	LEGEND	

0 Sanple location
C: Syntex composite sample
ND contaminate not
detected
D duplicate analysis

Notei All samples

collected at a
depth of 0-0.5 FT
All concentrations

in ppb
No EPA split samples
collected

TCBP H40
Tcpq ^opf

pCPP ljp "1 ITCOO 0.41 ~\ tTCOP 0.831 tTCOP 0 37

3925;	39*3	3961

I"! l"~l 1^1 I"| 1^

19 5.-2 0 0 6 0 | 2 0 54 3 0 0 lO |'2 0 5.< 3 0 oi'O |i05..3003 O | 205. 300"»O

I	I I I I I III

II	II II I I I

195. 2007 O 2 0 5.-30 07EO 205* 30 08© ,205. 30090 205. 301010

I I 1 I I I I

I I

I I I
II I I I

19*.1001;O l^oV.ifOOlO | 20"t; *0020 |.2 <>¦».¦> 0 0 3:0 | 204, 0 O^O

I I I I I t III

I I I I II I I I

191». 10 0 2 O 20t. 0120 120*. 1002O

l_l I. J

K O


-------
OU1 Soils
Lagoon Area -1982 Sampling


-------
AttaOv^erst M

t

EXISTING UGOOK

l«

Ko. 183
O.'-l ppb

No. J87
2.1 ppb

360 (I. -

Ko. 1E4
.7.2 ppb

Ko. 186
2.8 ppb*

' So-lJsLL*
. [IW I .

+

•	I #

-Ko.-jisr

e2i pp^

"1 ~

•	I •

1 i—j

' 'Ut ir

— 1- - -+•1	

13

I

( •

• i	| •

JL

I I |
, .•	I # ,

j" """""tlif fib-r-i
i • • i • r • i •

-j	J	i—

Ho. 1SS
7.8 ppb

I

Ko. 198

2.3 ppb

Ho. 197
1.? ppb

Ho. 190
1.6 ppb

Ho. 194
0.41 ppb

11

Ko. 195
0.29 ppb

3C3 (I.

n

o

OLD S10UGH

im



•j f i

I • I I * I

4||««

LAGOON AREA
Total Diaiin Analyses
By Capillary Electron Capture Gas Cinematography

Result; in Parts per Billion |ppb|
Co»r::t:d for '.Voter Content
Based on Certified Standard
•ivrs.'.nr nr nnpnr'rr •«...vr-r


-------
S;'. - vrv:-yv: '¦ ..!

TABLE4 '

LAGOON AREA DIOXIN RESULTS
_ .	V SAMPLES COLLECTED SEPTEMBER, 1982

¦ ¦ MaP:
. Z>e«ign«it ion

epA -4..

Synt«
besigria

X

t ion 8

Syht ex
Data (ppb)

EPA
Data (ppb)

.¦, A :

A

an3818

LI, L2

163

0.44



¦ .;\V-

: Bi '

AK3819

L6 ¦.-.¦'¦-



¦ -Wr' ¦

" I '

A

Ci

AN3844

L3, L4

184

7.2

¦ _ _ _.. .

A

D ¦¦..¦¦¦¦

AN3820

L5, L6

185

. .7.8 :

3.8 •

A

E.

AN3821

L 7, L8

186

2.8

1.6

¦ V

*

AS3822

18

¦ ---

	;T

0. 70 (0)

A ¦"

G'

AM3823

L9, 110

187

2. 1

--- '

'.' , *;

a

AN 3 8 24

L11, LI 2

188

9.0

. . - ---

" -¦.A :;-'

¦¦'¦"Bi.-

AN3826

L13, L14

189

¦' ¦ 13.



. 4'

¦ *;-• ¦. ¦

AN3827

LI 5 . L16

190

1.6

. --•»¦ .

¦ *'

R

AN3828

1/17, Li8

191

110.





' L "¦¦¦¦¦¦¦

AN3829

XI9, L20

192

26. ' .

---



:Hi- ¦¦¦"¦'¦

AK3830

L21, L22

193

340.



'¦¦"A'-'.

N: '¦

AN j 84.0

L23, L24

194

\0.41

'¦	

¦. A

O

-r--V.

L25, L26

195

0.29



•

P

AK3835

L28

.

--- ¦ ¦

0.25 (D)

A

Q

AN3836

L2 7, L28

197

1.2



A



AN3841

L29, L30

198

2.3 •

1.1



¦ST:-

AN3842

L28, L29



¦¦

0.25 (U)



1:' .

AN38J

L8,13,26

¦ ~~-



0.25 CU)

~

u:

AN38K

LI 2/7-14

¦V--



2.4

~ ;

V

AN38L

LI 5-24





60.2



w

i . .1

AN38M

L25-30

mm w a»



0.80 CD).

• • •

¦ I a InV«1 idat	i

(IT) ¦ he,as Than the Detection Limit

; ¦


-------
0U1 Soils
Lagoon Area -1985 Sampling


-------
NO



NO

NET

NO

0.05

S8&&'

0.13

NO

0

ffi -

MS

ND

m

HO



ifo

0.01

»=3

D
22.3

0
" 38

I am j
- ¦:

_E!

0 #.s

o fm

9.W

two



0

II

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*11 5«mplti if* eompe»i««» «e«p» tor that* ItbtlM 'D--Oi«cr»t»

MM

S-» M»
'»ioown '
Btm Of SMiplM- o to is M

areas enbineering gkcup

STtfTEX AGRIBUSINESS
VERONA ' FACILITY

LAGOON AREA

- «!««», IMS)


-------
4900"-

m

NO

0











frptfpif * d

ND



1 0;01



HO

Ih| •











ls=r,Il

At! Scmpl*t in Coraporttii unlnt i«tj»l»s 'O'-Oiiciiii

'II! Dttft

HO- umki

' (IW>

»»p»

s-mm
ffffBBI

as**

D«pth of ®«jnp(»«~ t,i ts j.o r««t

•IftCOftS ENGMEERIMB GROUP

STNTEX AGRIBUSINESS
VERONA FACILITY'
LAGOON AREA

fro#.


-------
mo® —

NO

4$m —

o

NO

D

ND

AM lampisa «r© cempottaj unleis latrefed "O'-Olsertls

HD- Not Otttafatf
20-100

MM >
-------
4300 -

D

N0(

0

m

o

wo



0

NO

m

m

o
m>

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All wmptu «r» cwnpotftu umhtsi (ab»I«d *D*-Dlacitte

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!-»(»»

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¦m '»'»»

• D»pth of i»(npl«»- «,g to « f»»t

JACOBS ENQ1NEER1N8 GROUP

STNTEX AGRIBUSINESS
VERONA FACILITY
LAGOON AREA

- MUStwft, IMI!

(adffgtttf fror
*M!l Iff?


-------
OU1 Soils

Lagoon Area - Remedy Implementation


-------
-w

fr - bolKlk





955 CMtVtow

i.-»»rrp'ln-j Pflttwi

. If

® ® l-f

Ls T

££



Ml R»Mt> or* ppb CJ.7.S-TCM



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$tL-|tM,>A9LZai

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sti.-maA7A9.ec

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SEL-lS27A9.3t.L2

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S€L- *«9.3CJ.92e.U



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SLT-95L2.?

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SELHSDUA4A6
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	&£>	 OOOOH ARtA

CftfCto# »y
"ft* *«r«


-------

-------
0U1 Soils
Slough Area -1985 Sampling


-------
All samples are composites exeept those labeled *0:- Discrete.

NU- hoi 0«t«ec«d

<(0»b
- Kgfe-1' S-»ffb

20-roo»k
'>(00 ffb

JACOBS .ENGINEERING GROUP

SYNTCX AGRIBUSINESS
VERONA FACILITY
SLOUGH AREA

Depth ol Samples- 0 to 1 feet 19B5 data

l««09tri from Genoa - Mitchell, 1583}
ApRtL tear	i". too*


-------
OU1 Soils

Slough Area - Remedy Implementation


-------
•APPENDIX 9

HS™«v£
v"h;v:;ys

ISTJNO.SLqUQH AREA PLAN



.gss^rsssSH-fs

EXISTING PLAN
5 LOU OH AREA

Ve


-------
Place Holder
for

Plan Sheet 6 of 7


-------
AKPfcNUIA V


-------
0U1 Soils
Trench Area -1982 Sampling


-------
VERONA TRENCH AREA

TOTAL DIOXIN ANALYSES

By Capillary Electron Capture
Chromatography

Results in parts per billion (
corrected for water content
Based on certified standard

* AVERACE QF DUPLICATE A"
9 TRENCH
° PERIMETER

N'o. 154

Ko p.pb* 1 1

¦I;. ¦

1 ¦ '

!
1

Tre^ji Nol

:l 1 1

—-Corner reference post
¦ T^^Trenc h No. 5

: No.—1-99 0.43 ppb 	


-------
3700
I

seoo

3900

4000

I

NO

E3253 5-20 ppb
l&asssl 2o-iooppb

'>100 ppb

19B2 and 1985 data
A« SampteB Discrete

Depth of Samples- 0 to 1 feet

JACOBS ENGINEERING GROUP

SYNTEX AGRIBUSINESS
VERONA FACILITY

TRENCH AREA

I adapt tt trem Ecolagj	WW)

APRIL 1967


-------
TABLE 2

TRENCH AREA DIOXIN RESULTS
SAMPLES COLLECTED SEPTEMBER, 1 982

Map
Desitnation



Syntex ¦

Sy nt ex

EPA

Total

EPA #

Dee ignat ion

Data (ppb)-

Data (ppb)

Depth (feet)

T1

AT& 501

150

0. 13

1.0 (U)

6.0

T2

AT4502

151

0. 13

	

8. 0

13

AT4503

152

0.21

		

9. 0

T4

ATA 504

153

0. 19

0.58 (U)

6.0

T5

AT4505

154

40.

	

9.0

T6

AT4506

155

3. 9

— — -

10.0

T7

AT4507

156

0. 34

" ~

\ 6.0

TB

AT4508

157

0. 90

1.0 (u)

13.0

T 9

AT4 5.09

158

16.

I

12. 0

-¦ T10

AT4510

159

0. 32



6. 0

Tl 1

AT451 1

160

0. 52

- — —

4. 5

T 1 2

A T 4 5 1 2

161

19.

— — —

4. 5

TI 3

AT4520

162

3. 3



9. 0

T1 4

AT4519

163

69.

---

10.5

Tl 5

AT4518

164

3.0

0.25 (U)

12.0

Tl 6

AT4517

165

0. 16



13.0

Tl 7

AT4516

166

52.

4.5 (J)

10. 5

T1. 8

AT451 5

167

0. 033

- — —

13.0

Tl 9

AT4514

168

0. 21

---

12.0

T20

AT4 513

169

0. 12

		

6. 5

PI

AT4532

199

0.43

	

15.0

P 2

A T 4 5 3 3

200

0.45

	

15.0

P 3

A T4 5 34

201

0.041

- - -

15.5

P4

AT4535

202

ND



7.0

P5

AT4536

203 .

ND

---

15.0

P6

AT4537

204

0.023

---

15.0

P7

A T4 5 3 8

205

ND

---

12.5 '

P8

AT4539

206

0. 075

- - -

15.0

P9

AT4540

207

18.

	

15.0

PI 0

AT4541

147

.14

0.25 («)

15.5

P J 1

A T4 542

148

.007

0.25 (U)

15.0

?U

AT4 543

149

.013

	

15.0

1 1' .1

AT4521

150

	

0.2 5 (U)

Water

| 12

AT4522

151

	

0.25 (U)

11

i ' T-3

AT4523

152

	

I



1 14

AT4 5 24

153

	

I

II

] T5

AT4.525

154

	

41.0

¦; t6

AT4526

155

	

0.25 (U)

ir

ii

¦T 7

AT4 527

156

	

0.25 (U)

T8

AT4 52 8

157



0.25 (U)

ii
it

T9

AT4 5 29

158



0.25 (U)


-------
(TABLE 2 -- Continued)

TRENCH AREA DIOXIN RESULTS
SAMPLES COLLECTED SEPTEMBER, 1982

Map



Syntex

Synt ex

EPA

Tot al

DeB ignation

EPA #

Des ignat ion

Data (ppb)

Data (ppb)

Depth (feet)

Tl 6

AT4546

165

.	

0.25 (U)

Wat er

T1 7

AT4530

166

¦	.

0.25 (U)

II

A

AT45A

PI- 7

	

0.25 (U)

Compos ite

B

AT4 5B

P8-12

	

0.51 (U)

II

C

AT45C

T13-16

	

1.33

II

D

AT45D

Tl7-20

	

0.50 (U)

II

E

AT4 5E

T5-8

	

3.0 (J)

II

F

AT4 5F

Tl0-12

	

1.5

II

G

AT45G

Tl -3

^ •

0.10 (U)

II

(U) B Less Than The Detection Limit

I ¦ Invalidated

I

(J) ¦ Approximate Value
ND • = Not Detected

/'¦f '>><" f

y — y~/n>' ^


-------
OU1 Soils
Trench Area -1985 Sampling


-------
FKLDWIITJOATIONSGF UHDOWWU1D
HA2MOOU9>Wm «Tes

till llfOIT T« HI M>».

~iftti Trench Area Sample.
Results
Syntex Compliance
Monitoring
Verona, MO
***- fl-ft-7-.a408-23B

•Ulllt MMIMJIMIM

PKKVMWVNV- !*!•-
112.2000 AK6S1034
O

312.1000 AKA5I035

'«

* Sanpie location
Syntex ssnple
results
""" EPA eanple •

results
KD contaminate not
detected
0 duplicate analysis
m value ia below the
quantitation limit
but above the
detection limit

::otei ah sample* are composite
All result* are in ppt


-------
0U1 Soils

Trench Area - Remedy Implementation


-------
X

EXISTING TRENCH PLAN

r* »»•

wall {WW fPd ISQK KWMtS.

Mx no an w/v» m ram* mo
ru NitAt n re v oavco at
iwiw aram uwl
m Mcramu mnx u 91m

1X7.

APPENDIX 8

rtmn»» iwund

ItOM
v»»n»
TO MIBftM .
IltlTINt ¦

^mcmm loc*tw 
-------
APPENDIX 8


-------
0U1 Soils
Grid Area - 1985 Sampling


-------

-------
Appendix C: 0U2 Texturai References

78

Fourth Five-Year Review Report for Syntex Facility Superfund Site


-------
At 1 <•: in x C Figure 1


-------
Priority Pollutant List

i

0

~


-------
Appendix A to 4© CFR, Part 423—126 Priority Pollutants

§01 Acenaphthene

047 Rmniotbrrn (trihromomethane)

(Wfi Dieldrin

002 Acrolein

048 [>H'l)K»robronKiTikih

(•«'! ('hlindane (technical mixture and

(1(1*? Aaylonitrilc

0">1 ( |ilii'odi,n>>,ii.inuilkinv'

in;-t:ilnilite>.(

(II14 Benzene

052 HLXjchlot.i'Hruidk'i'i-

0'»2 4,4-DDT

005 Bermdirte

0>3 lfe\4ChIwim\v!ofvr>t,;ti;ute

(>l>3 4,4-DDF (p,p-l)DX)

000 Cm bun tetrachloride

054 ibophoroue

o Alpha-cndosullan

007 C!i!oroheri7ciic

056 Nitiobcn/uie

OOtt Beta endusulfan

O0X 1 ,2,4-triehlsirabei)?,ene

057 2 isitMphepol

O'i"1 I'ltdosnlfan sulfate

0(il> He\,ic!iitwhcn/ctte

058 4-nUrnpherwl

f'K I'luii in

010 1,2-diehloiocfhatie

059 2,1-duulrophenol

O1*' FuKn aldehyde

011 1,1,1-lrichIorcothanc

OVl 4,0 (1jmtrOO vH .i'!

Hl't (kptiielilor

012 Hexachloroethane

0M \ niUovHiirnUhvLurae

101 Heptuch'ot epoxide

(11 > 1,1 -dichloroethane

062 N-nttrosodiplu m Li ,n i •

, BS!(' Hevaehlomcyclohexane)

014 1,1,2-trichloroelhane

0(>4 N-mtiOhe«di-n-pu>p)Lsniin

h>> Alpha BHC

015 1,1,2,2-tetrachioroethanc

0m Pent.iehlon, (phenol

103 Beta-IJHC

016 Cblorocthanc.

Oca I'li.'no!

i04 iiamnki-HliC i lindane i

01S Bii(2-ch1nrocl!)yD ether

0m> H,sf2-ethvi:K \v 1 > philulate

10s Delui-BHC" (l'( 11 -polyvhlorinatcd

() 1 2-dilowethy! \ in> 1 Uher (mixed)

(!{>" Btit>l 1HT7> 1 piithaliite

hphenvM

Dili ?-cblorof)aphth<;ie; c

OfiX I)i-N-But\ 11'htltjdiiH

1 PC B-1242 (Arochlor 1242)

021 2,4,0 tnehloiophenol

0(i4 l)i-ii ov">l plr.h.slute

107 P( Ft-' 2^4 i Arochlor 1254)

II.12 ParaehWumeia crcsol

um Diethvl Phthabte

108 SVB 1221 tArochlor 1221)

023 OiloRii'onn (trichloromclhane)

(HI Dimethyl phthnl.iie

109 PrB-1232 ("Aioehlor 1232)

024 2-ohlorophcnol

072 l,?-ben/anthi\ni-ue tbenzo(a)

110 Pt'B-1248 (Arochloi 17418)

025 1,2 dschlorobenzenc

anthracene

111 PCB-12t>0 (Arochlot 12M1)

026 1,3-dichIorobenzene

073 Benzot,i)p\iene (3,4-benzo-pyrcne)

112 PCB-1016 (Arochlor 101b)

027 1,4^dsL-hloTobci;7Ciic

074 3,4 ikn.-.itluaranthenc (benzo(b)

1 i1 TVvaphene

028 3.3-diehlorttbeii7idine

lluoidntitcne)

! 14 Atititiiony

02" 1,1 -dichlorocthytcne

07<> ii,12 K-nzofluoranthene (benzo(b)

1 !> Atswue

0 30 1,2-tranvdicMofucthylenc



1 11* \shevtos

031 2,4-dichloropliennI

tfO Clirvxctie

1! ~ Ben Ilium

032 1,2-didi! oropr opui i e

07? Aien.iplithylene

1 1 fi

033 1,2-dichloropro[>\ icne

078 Anthracene

1H ( Imnuium

(1,3-dichIoropropene)

079 1,12-benzopeiyicnc (beiKo(ghi)

'120 ( t'ppcr

034 2,4-dimethylphenol

perylene)

121 I'vantde, Total

035 2.4-diriit'*o(i,!uc»c

080 Fluorcnc

122 Lead

036 2,f> dmitrotolucne

081 Phenanthrene

1 23 Yleicuiy

0'"* 1,2-dsphen> Ihydrame

0h2 !, 2. "\t>-diben/anthracene (dibenzo(,h)

',24 Mkkel "

038 I-thvlben/enc

anthracene i

12> Seleijium

03'; FhiiManthenc

Ot^ Indtno(.1,2,3-cd) pyrenc

12(^ Silver

040 4-chlorophcnyl phenyl ether

12,3-o -pheviivlene pyrcne)

I27 Fh.illiuiii

041 4-brornopherty 1 phenyl ether

084 INtene

12«> SiKer

042 Bis(2-chloroisoprop> I) ether

085 Tctrt'chloroethylenc

128 Zinc

043 Bis(2-chlt>roetho\y) methane

ONp Toluene

12') 2.3,7,8-tetrachloro-dibenzo-p-dioxin

044 Methylene chloride (dieh)c»romethanc)

0H7 Jnchiiiroeibslene

(KDlli

045 Methyl chloride (dichlurcmieshane)

(1HS Vinyl chlorsde tchlorocthylcne)



046 Methyl bromide (broutomethane)

089 Aldtio




-------
OU2 Groundwater
Trench Area - Original Monitoring Wells


-------

-------
1U0

me

c;,lw
§

O12S0

5

A'

mo

,M0 d

5

,M#a

1170 ^

w

I

12f0 *

1220

\

LEGSBO:

Alluvium: Silf ond
clay, with basal
chet+y grovel.

I Weathered Bedrock
I (Residuum), Clay
and cherty limestone

I Cherty Limestone
I (Misslssipplon)

Reeds Spring Fm.

Uthologic contact;
dashed where
* interpreted.

HORIZONTAL SCALE
0 50 100	200

- rrn

VERTICAL EXAGGERATION: JX

Figure 3-3. Geologic Cross-Section A-A', Syntex Verona Facility


-------
B

i sso
1540
1930
1320

t

9

§1290

3

• 12W

f

$U7»

8

t 1260

u

I 1230

(220





Bv

13M

1340

1330

I3»

1310

1300

I ttt |
5

n

I2S0 j

1

1270 ?

IMO

1190 §

1240 ^

1230

1210

1210

1200

119*

1180

1170

1100

1190

\

LEGEND:

Weathered Bedrock
(Residuum), Ctay
ond cherty limestone

I Cherty Limestone
I (Mississtppian)

Reeds Spring Fm.

I Sllty Limestone/
I Shale

I Coffer Dolomite (?)
J'(Ordovlclon)

Uthologle contact;
dashed where
* Interpreted.

HORIZONTAL SCALE
0 23 30	100

FEET

VERTICAL EXAGGERATION: Z.SX

Figure 3-4. Geologic Cross-.f

¦» B-B', Syntex Verona Facility


-------
0U2 Groundwater
Floodplain Well Cross-Sections


-------
1 ^

C'

1270
12M
ItSO
1240

,u#3

imo |

121° |

,iwi

tin g
iik §

it7a .
1160

use

LEGEND*

f-Tl Alluvium: Slit ond
IP i*l clay, with basal
cherty gravel.

ESChBrty Limestone
I'll (Mlssistlpplan)

Reeds Spring Fm.

\Llthologlc contact;
dashed where
* Interpreted.

HORIZONTAL SCALE
0 125 WO	900

FEET

VERTICAL EXAGGERATION: I OX

Figure 3-5. Geologic Cross-Section C-C, Syntex Verona Facility


-------
lift

§
i

-»tm



(1?X



flM

llfft

«1«»

LEGEND"

cloy, with bos®!
chtHy )vtivt)<

£3x3 Chtrfy Um«tf

ft" '•'""*1 /uiMkttRrilfin^

Reeds Spring fm.

\ yih«l#flle contoefc
N dashed wl

1 lnftrprtled.

HOtfZONI/M. SCAtX
« »

Fljporc 3-4 Geologic Cross-St -V, Syntex Verona Facility


-------
ttm

mm

mm

7
5

3

•*

aw

i

i

i

W
«*

|tw

!«<»

two#

* WV- ' 		,		

jr'xti.ji'lI.i;: trri, ,

ii*

j

iw §

I

w« §

1 Mrt v

n»

•««

list

pSf AlKMum: Sit and

Bsaefaf, wllli beta?

etmty Qravvl.

FT! Ctwff Umwtwvi

iTl

C!!P \WtI5fSSippfOrl|

R**dt Spring Fm,

\ UHwtogic contact;

» aa»n#a wntr®

^ III 1 wfTJroT'iv•

mmmtm, mm

rm

mmm 3-7, Geologic Cross-Section E-E\ Synlex Verona Facility


-------
OU2 Groundwater.

Floodplain Wells - Data (2003-2011)


-------
60S N. Boocville Avenue
Springfield, MO 65806
(417) 864-6444 • Fax: (417) 864-6445
www.fblh.oom

RECEIVED
DEC 23 2011

SUPERFUND DIVISION

December 22,2011

Mr. Robert W. Feild

U.S. Environmental Protection Agency

Superfund Division

901 North Fifth Street

Kansas City, KS 66101

Dear Mr. Feild:

RE: PROJECT NUMBER 00FG1239.00 - OU2 VOLUNTARY GROUNDWATER

MONITORING REPORT, SYNTEX FACILITY SUPERFUND SITE, VERONA, MO
(EPA ID #MOD007452154)

On behalf of Syntex Agribusiness, Inc., enclosed is an updated Analytical Results Table
from the report on voluntary groundwater monitoring performed at Operable Unit 2
(OU2), Syntex Facility Superfund Site, Verona, Missouri. The report on voluntary
groundwater monitoring performed at OU2 was submitted in May 2006. The purpose of
the monitoring was to provide additional data to support site closure activities. Hie
updated table shows the voluntary monitoring that was conducted at four OU2 wells from
August 2003 through the latest round of sampling, which was performed in August 2011.
The August 2011 results do not change the conclusions of the May 2006 report on
voluntary groundwater monitoring.

If you have comments or questions about the report, please contact Sandra Potter at 417'
836-3619 or Matthew Shaps at 650-467-4095.

Sincerely,

Foth Infrastructure & Environment, LLC

Enclosure

cc: Matthew Shaps, Syntex Agribusiness, Inc.

P:\Syntex\Verona\Wmk ProductJ\Rp» on Voluntary MonitoringUW. Addendum 2011 D*ta\L-VoluntBiy Grouwtwiter Monitoring Report -12-22-
II.docx

Sandra L. Potter

Lead Environmental Scientist

Kris R. Gamble

Project Environmental Specialist


-------
Syntex - Verona
Analytical Results
Dsn Compilation August 2003 - August 2011 Voluntary Sampling

CONFIDENTIAL
ATTORNEY-CLIENT PWV1LB2D

OU-2



1

Aug,
2003

Feb.
2004

Aug.
2004

Feb.
2005

July
2005

Aug.
2006

Ang.
2007

Aug.
2008

Aug.
2009

Srpt
2010

Aug.
2011

Voluntary
Avg.

AOC avg.

VOC«(u«fU

1

Acetone

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd



1.0 O)

Chlombeiuene

nd

nd

nd

nd

nd

nd

nd

nd

nd

ntT

nd





Methylene chloride

nd

nd

nd

nd

nd

nd

nd

nd

2J6JB

nd

nd

ZS(1)

4.0(2)

1,4-Dioxane

nd

nd

nd

nd

nd

nd

nd

nd

od

nd

nd





Ethylbenzene

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd





1.1.2.2-tetra<±loroetiume

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd





Tetrachloroetbene

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd





1,4-dlchlorobenzene

nd

ad

nd

nd

nd

nd

nd

nd

nd

nd

nd





Toluene

nd

nd

nd

nd

nd

0.97 IB

02 JB

nd

0.55 J

nd

nd

057O)





nd

nd

nd

nd

nd

nd

nd

nd

nd

rxi

nd



1.0(1)

8VOC*(u«*L>



























BH (i-rtfolhevNltohfhaLilc

25 B

nd

nd

ml

od

nd

nd

nd

nd

aoj

nd

fl. J CI

11.0 ft)

1,3-dichlarobenzene

nd

nd

nd

.. nd

Pd

nd

nd

nd

nd

nd

nd







nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd





Naphthalene

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd





1,2,-4-trtcblorobeniene

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd





1,2,4,5-tetrachlorobenrenf

nd

nd

nd

nd

nd

nd

nd

nd

nd

nirs identified w YhemknK ai concern" In the JIUO draft ml aMt*«nwnt.

Voluntary avg - Aveiages Indicate avenge at detected values to voluntary sampling events (2003 - 2011V Numbers to

parentheses Indicate number of detections in data set
AOC avg ¦ Average of detected values chxrtng 8 quarters of AOC sampling,
j ¦ Estimated result Remit Is ten than quantitation Bmtt

B - Method blank imtamluafloc. The asaodated metbod blank contains the analyte at a reportable level

Q - Estimated modmum possible concentration.

N - Spiked analyte recovery was outside stated control limits.

ml - Analyte not detected.

MW-21 was replaced by MW-21R In 2007.

Foth Infrastructure and Environment

page 1 of 4

12/22/2011


-------
Syntex - Verona
Analytical Results
Data Compilation August 2003 - August 2011 Voluntary Sampling

CONFIDENTIAL
ATTORNEY-CLIENT PRIVILEGED

OU-2

MW-6

Aug.
2003

Feb.
2004

Aug.
2004

Feb.
2005

July
2005

Aug.

2006

AUg.
2007

Aug.
2008

Aug.
2009

Sept.
2010

Aug.
2011

Voluntary
Avg.

AOC avg.

VOCa: (ugA.)



Acetone

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

8.1 J

s.ia>

36.5(2)

(hlorobeniene

90

67

72

52

G4

78

61

25

09

77

77

hunu

lit (16)

Methylene chloride

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd



13J(3>

1,4-Dioxane

nd

nd

nd

nd

nd

nd

nd

94J

nd

35 J

74 J

67.7 (3)



Ethylbenzene

6.S

1.2 J

S3

1.6 J

3J

nd

1.4 J

0.33 J

nd

0.S1J

nd

1.02 m

SJ (13)

1.1,2.2-tetradjloroethane

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd





Tetrachloroethene

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd



SO)

1,4-dlchlorobenzene

14

a*

16

13

12

U

10 B

5.1

nd

5.7

5.1

*33(10)

11J (10)

Toluene

9.7

nd

19

19

39

0.65 JB

3.1 JB

0.35 J

0.9 J

6.1

nd

IO*?(9)

12.7(11)

Xylene (total)

59

16

61



29

8.7J

14

0.45 J

1.6 J

83 J

5.2 J

19JSU1)

«

























SVOCa: (ugfl)



























His (_>-<¦ denote aiulytrt Identified »"chemicals of concern" in the -txxi draft risk asw-isment.

Voluntary avg - Avenges Indicate avenge af detected values In voluntary sampling events (2003 - 2011). Numbers in

parentheses Indicate number of detections In data set.

AOC avg - Avenge of detected value* during 8 quarters of AOC sampling.

J ¦ Estimated result. Result is less than quantitation limit.

B - Method blank contamination. The associated method blank contains the analyte at a reportable leveL

Q - Estimated maximum possible concentration.

N - Spiked analyte recovery was outside stated control limits.

nd - Analyte not detected.

MW-21 was replaced by MW-21R In 2007.

Foth Infrastructure and Environment

page 2 of 4

12/22/2011


-------
J-Tt. I Aug. I Voluntary

Acetone

Bis ^-r(hylhfv\l|ph!hA)ji
ij-dlchlorobenrenc
ilfxacbloroph?ne	



tram ao3 • 06

Chromium

Z22LHL

L*t<*L

Syntex Verona
Analytical Results
Data ComptUtico August 2003 - August 2011 Voluntary Sampling

CONFIDENTIAL
ATTORNEY-CLIENT TOVHJEGED

MW-1SA

Aug

2005 July 2005

2006

AOC «vg.

HbthU^trdfw. drnotr an^t^ Wrmin«l«"rhrmkiilx of mncrn,* In thr 2mm draft risk assessment

parentheses iJSSSJSK ZSmEZS™ *	^^ Nunibtre ta

AOC an-Average of detected values during a quarters of AOC sampitn.

J - Estimated mult Result Is lets than quantitation limit

5	^ ^	^

N • Spflted analyte recovery was outside stated control limits.

od - Analyte not detected.

MW-21 was replaced by MW-21R in 2007.

Foth Infrastructure and Environment

page 3 of 4

12/22/2011


-------
VOCm: (un/li

Acetone

2UL2L

(2-ethvlhexvi)phthalatr

Nmhthjltne

1 ..^.l-trlchlornlynzen"
1.2.4.5-tetnidblorobenTwn»

3Q40B

Syntex - Verona
Analytical Results
Data Compilation August 2003 • August 2011 Voluntary Sampling

CONFIDENTIAL
ATTORNEY-CLIENT PRIVILEGED

Ou-2

Aug.
2004

voluntary

Aug.
2011

MwMIWaj ¦rt^mio.hofmmvrn- m ,he 2000 draft risk o*„n*nt

S'ESSSSSSSSSSSSE1	m.

N - Spiked analyte recovery was outside stated control limits,
nd - Analyte not detected.

MW-21 was repUced by MW-21R In 2007.	mp**4 br did

Cbtdctdbr. SIP

Foth Infrastructure and Environment

page 4 of 4

12/22/2011


-------
OU2 Groundwater
Trench Area Wells - Data'


-------
IV

Volatile Orgnnic Compounds Detected Almve MCUs in Shallow Groundwater Samples,
January 1991 to April 1992, Syntcx Verona Facility

Well No.

1/30/91

Sampling Date §

4/25/91

7/31/91

10/31/91

1/2«/92

4/7/92

MW-I
MW-?

ND*
KTC"'

Dichlorometliane (110)"

MC~		

ND

Dichloromethane (13)

ND

ND

MW-3

NS

no

NS

" iND 	———

NS

	NS

NS

NS
NS

NS
NS

MW-4

NS

NS

NS

NS

NS

NS

| MW-5

ND

NS

ND

NS

ND

ND

MW-6

ND

Dichloromethane (441)

ND

ND

-• ND

ND • 1

| MW-7

ND

Dichloromeihnne (25)

ND

ND

ND

Nl)

MW-8

NS

NS

NS

NS

NS

NS

MW-9

ND

ND

ND

Nl)

ND

Nl)

MW-IO

NS

NS

NS

NS

NS

NS

MW-II

ND

ND

NS

NS

NS

NS

MW-12

Dry

Dry

Dry

Dry

Dry

Dry

MW-I 3

Dry

Dry

Dry

Dry

Dry

Dry

| MW-14

ND

ND

Dichloromethane (603)
1,2-Dichtoroelhane (643)

ND

ND

ND

MW-I4A

ND

ND

ND

ND

ND

ND

MW-15

NO

ND

ND

ND

ND

ND

MW-I5A

ND

Dichloromethane (364)

ND

ND

ND

Dichloromethane (19) |

MW-15B

ND

ND

ND

ND

ND

ND

MW-16

NO

ND

Dichloromethane (1000)
Toluene (1000)

ND

ND

ND

MW- Iftl)

Nl)

ND

ND

Nl)

ND

ND

MW-17

Dry

Dry

Dry

Dry

Dry

Dry

| MW-18

ND

Dichloromethane (66)

NS

NS

NS

NS

ND N*»ne ilclcclrd above MCI.-	( ) • r.mc*f>»r#li«»n in pgl\.	' NS • N»«<

NOTE: Trench Area wells are highlighted.
SOURCE: OU2 ROD


-------
Other Volatile Orgnnic Compounds Detected in Shallow Groundwater Samples,
January 1991 to April 1992, Syntex Verona Facility



Su?fo« tx» II

Wafl No.

I/XV9I

4/2S/9I

7/31*1

10/31/91

\mm

*nm

MW-I

Action* (TJ)

Acetone (1370)

Acetone (523)

ND

ND

ND

MW 2

""TfT-1
NS

NS

NS

NS

NS

NS

MW3

NS

NS

NS

NS

NS

NS

l MWA

MW-5

Acetone (22)
CMomberaene (30)

NS
NS

Acetone (693)

NS

Cfthmifcerucne (It)

CMorobra*** (SI)
Cubon diwUM* (21)

CMonihenicne (37) II

MW4

Cfctorebenzene (215)
EtfcylHenreoe (23)
Xylene* (76)

Acetone (3470)
CMorobenxen* (231)
Xylrne#-(2n

Acetone (12.291)

Acetone (22)
Chlornheiuene (446)
EthyfUenxene .(61)
Toluene (273)
Xylenes (2It)

Chlorotenxana f26l)
Eihylfc*nzcn> (20
XyUnet (St)

Chlorobensen* (224)
Eifeyfeeniene (22)
Xylene* (37)

MW-7

A(MW (II)
(~Mort4t«nren» (10)

Acetone (123)

Acetone (1591)

Acetone (10)

CfcioffibenzMM (12)

Chlorvfcenzene (15)

MW t

NS

NS

NS

NS

NS

NS

MW9

Acrt«M* (12)
(ItlufnKctizrM (116)

Cfcli>n>t»eruem (1 J)

Acetone (1993)
ChlotnhcfuerM (162)

Acetone (337)
Chton4»etucne (305)
Cerhon ilirtlfni* (21)

OitombmitM (234)

Chlorobenxene (217) |

MW-IO

HS

NS

NS

NS

m

NS .

MW-I 1

Acetnoe (4Wf)

Acetone (1930)

NS

NS

NS

NS

MW-ll

Dry

Oct

Dfy

Dry

or

Dry

MW.IJ

Dry

Dry

Dqr

1 Dry

Dfy

Dry

MW-14

Acefone (3706)

Acelooe (4470)

Acetone (IS, 149)

Acetone (55)

ND

ND

M* HA

Acetone flOtJ)

Acetone (170)

ND

ND

Acatom (31)

ND

MW IS

Acetone (31)

ND

Acetone (272t)

ND

ND

ND

MW !5A

Acetone (20)

Acetone (S290)

Acetone (3130)

Acetone (14)

ND

ND

MW.ISR

Acetone (54»
CHIonthenz tne (71)
Xylenes (7)

Acetone (5<50?
CMornhenzsue (64x

Acetone (2515)

Acetone (4505)

ChU>robtamt (ST)

t

Chlorobenxene (107) R

li > i Acci.ttK ;S55

n

ACflOOC {13C}



Ac«.-.w (24*> ' ND

2 >.;W < Dli ' Nl'

Acef«wii» Nl,.W*V i -  i

1 btW'7 '• Iky I Crr *!-t

•Vy Ort

I-	' ~ ~~ 	1			 		

Acmoiw ' Acffn -c '9

. NS ¦»

NOTE: Trench Area wells are highlighted

SOURCE: OU2 ROD


-------
SYN 1 tX "JluBjlgSS

NUTRITION AND CHEMICAL DIVISION P.O. BOX 1246 SPRINGFIELD, MISSOURI 65801 417-866-7291





July 5,1995
Mr. Steve Sanders

Remedial Project Manager, Superfiind Section
U.S. Environmental Protection Agency
Region VII

726 Minnesota Avenue
Kansas City, Kansas 66101

Re: Summary of Trench Area Monitoring Well Results - Syntex Agribusiness, Inc., Verona, MO
Facility

Dear Mr. Sanders:

Please find attached a summary of monitoring well results from the Trench Area at the Syntex
Agribusiness, Inc. Verona, MO facility per your request The Trench Area monitoring wells have been
sampled for volatile oiganics, semivolatile organics and 2,3,7,8-tetrachlorodibenzo-/?-dioxin (dioxin) on a
periodic basis since their completion. Two wells. MW-12 and MW-13, have not recovered sufficiently
during every sampling event for the collection of volatile organics, semivolatile oiganics and dioxin
samples. This is noted in the attached tables with the designation "NS".

If you have any questions, please give me a call at (417) 868-3337. Thank you for your patience in this
matter.	1

Sincerely,

SYNTEX AGRIBUSINESS, INC.

T. Scott Barton

Chemist, Environmental Affairs
Attachments

SB95-C33.doc



40034170
SUPERFUND RECORDS


-------
SUMMARY OF TRENCH AREA MONITORING WELL RESULTS
SYNTEX AGRIBUSINESS, INC., VERONA, MO FACIU7Y

MW-11

Analyte (mg/L)

May-93

Aug-93

Feb-94

May-94

NovW

Mar-95

Volatile Organics -

Methylene Chloride 0.039 Acetone 0.160

Acetone 0.016

ND

Methylene Chloride 0.014

ND



Acetone 0.720











Semlvolatile Organics

ND

ND

ND

ND

ND

ND

2,3,7,8-TCDD

NO

ND

ND

ND

ND

ND

ND No analytes were detected above quantitation limit.

.. . : •'.v „

¦1 V':	'A"'.	;





Pagel


-------
SUMMARY OF TRENCH AREA MONITORING WELL RESULTS
SYNTEX AGRIBUSINESS, INC., VERONA, MO FACILITY

MW-12

Analyte (mg/L)

May-93

' Aug-93

Feb-94

May-94

Nov-94

Mar-95

Volatile Oiganics

Acetone 48

Acetone 1.20

Acetone 0.020

NS

NS

ND





Chloroform 0.018









Semivolatile Organics

ND

ND

NS

NS

NS

NS

2,3,7,8-TCDD

ND

ND

NS

NS

NS

NS

NO No analytes were detected above quantitation limit.
NS Samplers) not collected because of insufficient recharge of well.

Note: A sample for volatile organic analysis was collected during March 1995.
However, this sample was collected without purging the well.

Page 2


-------
SUMMARY OF TRENCH AREA MONITORING WELL RESULTS
SYNTEX AGRIBUSINESS. INC., VERONA, MO FACILITY

MW-13

Analyte (mg/L)

May-93

Aug-93

Feb-94

May-94

Nov-94

Mar-95

Volatile Organlcs

Methylene Chloride 0.048 Acetone 1.10 Methylene Chloride 0.006

NS

NS

ND



Acetone 0.620



Acetone 0.020







Semivolatile Organlcs

ND

ND

NS

NS

NS

NS

2,3,7,6-TCDD •

ND

ND

NS

NS

NS

NS

ND No analytes were detected above quantitation limit.

NS Sample(s) not collected because of insufficient recharge of well.

Note: A sample for volatile organic analysis was collected during March 1995.
However, this sample was collected without purging the well.

Page 1'


-------
SUMMARY OF TRENCH AREA MONITORING WELL RESULTS
SYNTEX AGRIBUSINESS, INC., VERONA, MO FACILITY

MW-17

Analyte (mg/L)

May-93

Aug-93

Feb-94

May-04

Nov-94

Mar-95

Volatile Organics

Acetone 0.046

Acetone 0.046

Acetone 0.100

ND

Methylene Chloride 0.014

ND

SemlvolatDe Organics

ND

ND

ND

ND

ND

ND

2,3.7,8-TCDD

NS

ND

ND

ND

ND

ND

ND No analytes were delected above quantitation limit
NS Samplers) not collected because of Insufficient recharge of well.

( '

Page 4


-------
Trench Wells Sampling Results
Annual sampling conducted in August 2000

Well	 MW-11 MW-17 MW-18	MW-20 Trip Blank '¦

VOCs:











Acetone

ND

11

ND

5

ND

Chlorobenzene

ND

48

ND

ND

ND

Methylene chloride

ND

ND

ND

ND

ND

1,4-Dioxane

ND

ND

ND

ND

ND

Ethylbenzene

ND

ND

ND

ND

ND

1,1,2,2-tetrachloroethane

ND

ND

ND

ND

ND

Tfitrachloroethene

ND

ND

ND

ND

ND

1,4-dichlorobenzene

ND

8

ND

ND

ND

Toluene

ND

ND

ND

ND

ND

Xylene (total)

ND

ND

ND

ND

ND













SVOCs:











Bis (2-ethylhexyl)phthalate

ND

68

ND

26

NA

1,3-dichlonobenzene

ND

ND

ND

ND

NA

Hexachlorophene

ND

ND

ND

ND

NA

Naphthalene

ND

ND

ND

ND

NA

1,2,4-trichlorobenzene

ND

ND

ND

ND

NA

1,2,4,5-tetrachlorobenzene

ND

ND

ND .

ND

NA













Dloxin:











2,3,7,8-TCDD

ND

ND

ND

ND

NA

Notes:

VOC and SVOC results in ug/l (ppb)

2,3,7,8-TCDD results in ng/l (ppt) (Detection limit 0.10 to 0.14 ng/l)

ND = not detected above quantitation limit
NA = not analyzed

Please note that OU-1 welis MW-12, MW-13, and MW-19 were not sampled
Laboratory = Southwest Laboratory of Oklahoma, Inc.


-------
Trench Wells Sampling Results
Annual sampling conducted in July 2001

Well	 MW-11 MW-17	MW-18	MW-20 Trip Blank

VOCs:











Acetone

ND

ND

ND

ND

ND

Chlorobenzene

ND

ND

ND

ND

ND

Methylene chloride

ND

ND

ND

ND

2 J

1,4-Dioxane

ND

ND

ND

ND

ND

Ethylbenzene

ND

ND

ND

ND

ND

1,1,2,2-tetrachloroethane

ND

ND

ND

ND

ND

Tetrachloroethene

ND

ND

ND

ND

ND

1,4-dichlorobenzene

ND

5

ND

ND

ND

Toluene

ND

ND

ND

ND

ND

Xylene (total)

ND

ND

ND

ND

ND













SVOCs:











Bis (2-ethylhexyl)phthalate

ND

ND

ND

ND

NA

1,3-dichlorobenzene

ND

ND

ND

ND

NA

Hexachlorophene

ND

ND

ND

ND

NA

Naphthalene .

ND

ND

ND

ND

NA

1,2,4-trichlorobenzene

ND

ND

ND

ND

NA

1,2,4,5-tetrachlorobenzene

ND

ND

ND

ND

NA













Dloxln:











2,3,7,8-TCDD

ND

ND

ND

ND

NA

Notes:

VOC and SVOC results in ug/l (ppb)

2,3,7,8-TCDD results in ng/l (ppt) (Sample specific estimated detection limits (EDL) ranged from 0.010 to 0.018 ng/l)
ND = not detected
NA = not analyzed

J = Estimated value: concentration Is below limit of quantitation
Please note that OU-1 wells MW-12, MW-13, and MW-19 were not sampled
Please note that 1,4-dichlorobenzene in MW-17 was found at the limit of detection.

Laboratory = Southwest Laboratory of Oklahoma, Inc.

i


-------
Trench Wells Sampling Results
Annual sampling conducted in August 2002

Well 		MW-11 MW-17 MW-18	MW-20 Trip Blank

VOCs:











Acetone

ND

ND

ND

ND

ND

Chlorobenzene

ND

52

ND

ND

ND

Methylene chloride

ND

ND

ND

ND

ND

1,4-Dioxane

ND

ND

ND

ND

ND

Ethylbenzene

ND

ND

ND

ND

ND

1,1,2,2-tetrachloroethane

ND

ND

ND

ND

ND

Tetrachloroethene

ND

ND

ND

ND

ND

1,4-dichlorobenzene

ND

8

ND

ND

. ND

Toluene

ND

ND .

ND

ND

ND

Xylene (total)

ND

ND

ND

ND

ND













SVOCs:











Bis (2-ethylhexyl)phthalate

11

ND

ND

ND

NA

1,3-dichlorobenzene

ND

ND

ND

ND

NA

Hexachlorophene

ND

ND

ND

ND

NA

Naphthalene

ND

ND

ND

ND

NA

1,2,4-trichloro benzene

ND

ND

ND

ND

NA

1,2,4,5-tetrachlorobenzene

ND

ND

ND

ND

NA













Dioxin:











2,3,7.8-TCDD

ND

ND

ND

ND

NA

Notes:

VOC and SVOC results in ug/l (ppb)

2,3,7,8-TCDD results in rig/1 (ppt) (Sample specific estimated detection limits (EDL) ranged from 0.010 to 0.018 ng/l)
ND = not detected
NA = not analyzed

J = Estimated value: concentration is below limit of quantitation

Please note that OU-1 wells MW-12, MW-13, and MW-19 were not sampled

Laboratory - Southwest Laboratory of Oklahoma, Inc.


-------
Trench Wells Sampling Results
Annual sampling conducted in August 2003

Well			 MW-11	MW-17	MW-18	MW-20 Trip Blank

VOCs:











Acetone

5.9 JB

ND

ND

ND

7.0JB

Chlorobenzene

ND

58

ND

ND

ND

Methylene chloride

ND

ND

ND

ND

ND

1,4-Dioxane

ND

ND

ND

ND

ND

Ethylbenzene

ND

ND

ND

ND

ND

1,1,2,2-tetrachloroethane

ND

ND

ND

ND

ND

Tetrachloroethene

ND

ND

ND

ND

ND

1,4-dichlorobenzene

ND

6.8

ND

ND

ND

Toluene

ND

ND .

ND

ND.

ND

Xylene (total)

ND

ND

ND

ND

ND













SVOCs:











Bis (2-ethylhexyl)phthalate

12B

40

34B

7.2JB

NA

1,3-dichloroberizene

ND

ND

ND

ND

NA

Hexachlorophene

ND

ND

ND

ND

NA

Naphthalene

ND

ND

ND

ND

NA

1,2,4-trichlorobenzene

ND

ND

ND

ND

NA

1,2.4,5-tetrachlorobenzene

ND

ND

ND

ND

NA













Dloxln:











2,3,7,8-TCDD

ND

14

ND

B.5J

NA

Notes:

VOC and SVOC results in ug/l (ppb)

2,3,7,8-TCDD results in pg/l (ppq) (Estimated detection limit is 2 pg/l)

ND = not detected
NA = not analyzed

J = Estimated value: concentration is below limit of quantitation

,B = Method blank contamination. The associated method blank contains the analyte at a reportable level.
Please note that OU-1 wells MW-12, MW-13, and MW-19 were not sampled
Laboratory = Severn Trent Laboratory, Inc. - Earth City, MO


-------
Trench Wells Sampling Results
Annual sampling conducted in August 2004

Well	 MW-11 MW-17 MW-18	MW-20 Trip Blank

VOCs:











Acetone

3.3J

ND

5.8J

ND

3.9J

Chlorobenzene

ND

43

ND

ND

ND

Methylene chloride

ND

ND

ND

ND

3.9J

1,4-Dioxane

ND

ND

ND

ND

ND

Ethylbenzene

ND

ND

ND

ND

ND

1,1,2,2-tetrachloroethane

ND

ND

ND

ND

ND

Tetrachloroethene

ND

ND

ND

ND

ND

1,4-dichlorobenzene

ND

6.7

ND

ND

ND

Toluene

ND

ND

ND

ND

ND

Xylene (total)

ND

ND

ND

ND

ND













SVOCs:











Bis (2-ethylhexyl)phthalate

ND

ND

ND

ND

NA

1,3-dichlorobenzene

ND

ND

ND

ND

NA .

Hexachlorophene

ND

ND

ND

ND

NA

Naphthalene

ND

ND

ND

ND

NA

1,2,4-trichlorobenzene

ND

ND

ND

ND

NA

1,2,4,5-tetrachlorobenzene

ND

ND

ND

ND

NA













Dloxin:











2.3.7.8-TCDD

ND

15

ND

ND

NA

Notes:

VOC and SVOC results in ug/l (ppb)

2,3,7,8-TCDD results in pg/i (ppq) (Estimated detection limit is 2 pg/l)
ND = not detected
NA = not analyzed

J = Estimated value: concentration is below limit of quantitation

Please note that OU-1 wells MW-12, MW-13, and MW-19 were not sampled

Laboratory = Severn Trent Laboratory, Inc. - Earth City, MO


-------
Trench Wells Sampling Results
Annual sampling conducted in August 2005

Well	:	 MW-11 MW-17 MW-18 MW-20 Trip Blank

VOCs:











Acetone

ND

4.8J

4.4J

ND

ND

Chlorobenzene

ND

53

ND

ND

ND

Methylene chloride

ND

ND

ND

ND

ND

1,4-Dioxane

ND

25J

ND

ND

ND

Ethylbenzene

ND

0.5J

ND

ND

ND

1,1,2,2-tetrachloroethane

ND

ND

ND

ND

ND

Tetrachloroethene

ND

ND

ND

ND

ND

1,4-dichlorobenzene

ND

8.3

ND

ND

ND

Toluene

ND

ND

ND

ND

ND

Xylene (total)

ND

ND

ND

ND

ND













SVOCs:











Bis (2-ethylhexyl)phthalate

ND

ND •

ND

ND

NA

1,3-dichlorobenzene

ND

ND

ND

ND

NA

. Hexachlorophene

ND

ND

ND

ND

NA

Naphthalene

ND

ND

ND

ND

NA

1,2,4-trichlorobenzene

ND

ND

ND

ND

NA

1,2,4,5-tetrachlorobenzene

ND

ND

ND -

ND

NA













Dioxln:











2,3,7,8-TCDD

ND

4.8J

2.3QJ

3.6QJ

NA

Notes:

VOC and SVOC results in ug/l (ppb)

2,3,7,8-TCDD results in pg/l (ppq) (Estimated detection limit Is 2 pg/I)
NO = not detected
NA = not analyzed

J = Estimated value: concentration is below limit of quantitation
Q = Estimated maximum possible concentration

Please note that OU-1 wells MW-12, MW-13, and MW-19 were not sampled
Laboratory = Severn Trent Laboratory, Inc. - Earth City, MO


-------
Trench Wells Sampling Results
Annual sampling conducted in August 2006

Well		 MW-11 MW-17	MW-18 MW-20 Trip Blank

VOCs:











Acetone

ND

23J

6.3J

6.8J

ND

Chlorobenzene

ND

14

ND

ND

ND

Methylene chloride

ND

3.3J

ND

ND

ND

1,4-Dioxane

ND

ND

ND

ND

ND

Ethylbenzene

ND

ND

ND

ND

ND

1,1,2,2-tetrachlonoethane

ND

ND

ND

ND

ND

Tetrachloroethene

ND

ND

ND

ND

ND

1,4-dichlorobenzene

ND

ND

ND

ND

ND

Toluene

1.2JB

1JB

0.31JB

1.1 JB

0.92JB

Xylene (total)

ND

ND

ND

ND

ND













SVOCs:











Bis (2-ethylhexyl)phthalate

ND

ND

ND

ND

NA

1,3-dichlorobenzene

ND

ND

ND

ND

NA

Hexachlorophene

ND

ND

ND

ND

NA

Naphthalene

ND

ND

ND

ND

NA

1,2,4-trichlorobenzene

ND

ND

ND

ND

NA

1,2,4,5-tetrachlorobenzene

ND

ND

ND

ND

NA













Dioxfn:











2,3,7,8-TCDD

ND

3.3QJ

ND

7.9QJ

NA

Notes:

VOC and SVOC results In ug/1 (ppb)

2,3,7,8-TCDD results in pg/l (ppq) (Estimated detection limit Is 2 pg/1)

ND = not detected
NA = not analyzed

J = Estimated value: concentration is below limit of quantitation -

B = Method blank contamination. The associated method blank contains the analyte at a reportable level.
Q = Estimated maximum possible concentration

Please note that OU-1 wells MW-12, MW-13, and MW-19 were not sampled
Laboratory = Severn Trent Laboratory, Inc. - Earth City, MO


-------
August 20, 2012

Ms. Laura Price
Remedial Project Manager
EPA Region VII
901 N. 5th Street
Kansas City, KS 66101

Dear Ms. Price:

RE: Syntex Agribusiness, Inc., Verona, Missouri OU-1 (Trench Area) Groundwater Data

Groundwater monitoring data from OU-1 (Trench Area) monitoring wells MW-11, MW-17,
MW-18 and MW-20, for the period from 2002 through 2011, are enclosed for your use.
Groundwater samples were analyzed for a select list of volatile and semi-volatile organic
compounds and 2,3,7,8-TCDD using EPA-approved methods. The following analytical methods
were used:

Please note that the enclosed volatile and semi-volatile data are reported in units of micrograms
per liter ((ig/L) and the 2,3,7,8-TCDD data are reported in units of picograms per liter (pg/L).

Please call me at (417) 836-3621 or send an email to bob.kick@foth.com if you have any
questions or comments.

Analyte

Method

Volatile organic compounds
Semi-volatile organic compounds
2,3,7,8-TCDD

SW-846 8260B
SW-846 8270C
SW-846 8290

Sincerely,

Foth Infrastructure & Environment, LLC

Robert M. Kick, RG
Senior Project Manager

'Client Director

cc: Matthew Shaps, Syntex Agribusiness, Inc.
Jim Price, Spencer Fane

\\spl\Da(a\Fom:stcr\clicnts\SynlcxWerona\Work Producis\5 ycarrcviews\2012\L-Syntcx OU1 OW Data 20120816.docx
605 N. Boonville Avenue • Springfield, MO 65806 • (417) 864-6444 • Fax: (417) 864-6445


-------
Table 1

Historical OU-1 Trench Area Groundwater Analytical Summary
Syntex Agribusiness, Inc., Verona, Missouri

OU-1

MW-11

Aug-02

Aufl-03

Aug-04

Aug-05

Aua-06

Aug-07

Auo-08

Aug-09 I

I Aug-10 I

[ Aug-11 I









1



Acetone

< 5

5.9 JB

3.3 J

< 20

< 20

< 20

< 20

< 20

< 20

< 20

Chlorobenzerve

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

Methylene Chloride

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

1,4-Woxano

< 500

< 400

< 400

< 400

< 400

< 400

< 400

< 400

< 400

< 400

Ethylbenzene

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

1,1,2,2-T etrachloroethane

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

T etrachloroethene

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

1,4-Dichlorobenzene

< 5

< 5

< 5

< 5

< 5

0.19 JB

< 5

< 5

< 5

< 5

Toluene

< 5

< 5

< 5

< 5

1.2 JB

0.3 JB

0.34 J

< 5

< 5

< 5

Xylene (total)

< 5

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10



I I

05^ aW '";:*'• ui'-R1

...

	 .j



Bis (2-ethylhexyt)chthalate

11

12 B

< 10

< 10

< 10

< 10

< 12

< 10 <

I < 10

< 10

1,3-Dichlorobenzene

< 10

< 10

< 10

< 10

< 10

< 10

< 12

< 10

< 10

< 10

Hexachtorophene

< 200

< 100

< 100

< 100

< 100

< 100

< 120

< 100

< 100

< 100

Naphthalene

< 10

< 10

< 10

< 10

< 10

< 10

< 12

< 10

< 10

< 10

1,2,4-T richlorobenzene

< 10

< 10

< 10

< 10

< 10

< 10

< 12

< 10

< 10

< 10

1,2,4,5-Tetrachlorobenzene

< 10

< 10

< 10

< 10

< 10

< 10

< 12

< 10

< 10

< 10



I 1

ItfjiiB ;<•>' -tw liifJ ; 1

2,3,7,8-TCDD | < 29 f < 2.61 < 4.11< 4.4 | < 1.5| < S.3T < 3.3|< 4.0 | < 9.91 < 4.4|

Bold data indicates analyta detected
< ## - analyte was not detected

J ¦ Etflmated value, concentration below quantification limit
B « Method blank contamination, associated blank contains

analyte at reportable level
Q = Estimated maximum possible contamination

1 Of 4

Prepared by. TSB
Checked by: BJ.Q


-------
Table 1

Historical OU-1 Trench Area Groundwater Analytical Summary
Syntax Agribusiness, Inc., Verona, Missouri



l-i'-lT-.J	

Chlorobenzene

Methylene Chloride

1,4-Dioxaric

Ethytbenzene

1.1.2.2-Tetrachloroethane

T etrachloroethene
1,4-Dichtorobertzerte

Toluene

Bis (2-ethythexyt)phthalate

1,3-Dichlofobenzene

Hexachlorophene

Naphthalene

1,2.4-T richlorobenzene
1,2,4,5-Tetrachlorobenzene

Bold data Indicates anatyte detected
< «# - anatyte was not detected

J = Estimated value, concentration below quantification limit
B * Method blank contamination, associated blank contains

anatyte at reportable level
~ ¦ Estimated maximum possible contamination

2 of 4

Prepared by: TSB
Checked by. DJD


-------
Table 1

Historical OU-1 Trench Area Groundwater Analytical Summary
Syntax Agribusiness, Inc., Verona, Missouri

OU-1

MW-18

Aug-02

Aug-03

Auo-04

Aug-05

Aua-06

Auo-07

Aua-08





UuyJ

Ki/.ririr j,













Acetone

< 5

< 20

5.8 J

4.4 J

6.3 J

< 20

< 20]

< 20

< 20



Chlorobenzene

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

Methylene Chloride

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

1.4-Dioxane

< 500

< 500

< 400

< 400

< 400

< 400

< 400

< 400

< 400

< 400

Ethylbenzene

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

1,1,2,2-Tetrachloroethane

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

Tetrachloroethene

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

1,4-Di chlorobenzene

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

Toluene

< 5

< 5

< 5

< 5

0.31 JB

0.23 JB

< 5

0.63 J

< 5

< 5

Xylene (total}

< 5

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

















«

Bis (2-ethyihexyl)phthalate

< 10

34 B

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

1,3-Dichlorobenzene

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

Hexachlorophene

< 200

< 100

< 100

< 100

< 100

< 100

< 100

< 100

< 100

< 100

Naphthalene

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

1,2,4-T richlorobenzene

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

1.2,4,5-T etrachlorobenzene

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

p6ra ieheESE

2,3,7,8-TCDD



Bold data indicates analyte detected
<*#- analyte was not detected

J - Estimated value, concentration below quantification Bmll
B » Method blank contamination, associated blank contains

analyte at reportable level
Q ¦ Estimated maximum possible contamination

3 of 4

Prepared by: TSB
Chocked by. DJO


-------
Table 1

Historical OU-1 Trench Area Groundwater Analytical Summary
Syntex Agribusiness, Inc., Verona, Missouri

OU-1

MW-20

Aug-02

Aug-03

Aug-04

Aug-05

Aug-06

Aug-07

Aug-08

Aug-09

Aug-10

Aug-1l|

!i£i iSCJiSbi.





. .

		

1 1

Acetone

< 5

< 20

< 20

< 20

5.9 J

< 20

< 20

< 20

< 20

< 20

Chlorobenzene

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

Methylene Chloride

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

1,4-Dioxane

< 500

< 400

< 400

< 400

< 400

< 400

< 400

< 400

< 400

< 400

Ethylbenzene

< 5

< 5

< 5

< 5

< 5

< 5

0.068 J

< 5

0.37 J

< 5

1,1.2,2-Tetrachloroethane

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

Tetrachloroethene

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

1,4-Dichlorobenzene

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

< 5

Toluene

< 5

< 5

< 5

< 5

1.1 JB

0.24 JB

< 5

0.41 J

< 5

< 5

Xylene (total)

< 5

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

< 10

I I



i " .. . u





1



Bis (2-ethy1hexyl)phtha!ate

< 10

7.2 JB

< 10

A
O

< 10

< 10

< 11

< 14

15

4.5 J

1,3-Dichlorobenzene

< 10

< 10

< 10

< 10

< 10

< 10

< 11

< 14

< 14

< 11

Hexachlorophene

< 200

< 100

< 100

< 100

< 100

< 100

< 110

< 140

< 140

< 110

Naphthalene

< 10

< 10

< 10

< 10

< 10

< 10

< 11

< 14

< 14

< 11

1,2,4-Trichlorobenzene

< 10

< 10

< 10

< 10

< 10

< 10

< 11

< 14

< 14

< 11

1,2.4,5-T etrachlorobenzene

< 10

< 10

< 10

< 10

< 10

< 10

< 11

< 14

< 14

< 11

I I

v. 'i; i .







1

2,3,7,8-TCDD | < 31 | 6.5 J | < 3.81 3.6 QJ | 7.9 QJ | < 5.51 < 3.1 | < 4.71 < 12 | < 7.61

Bold data indicates anatyte detected
< MM . anatyte was not detected

J • Estimated value, concentration below quantification limit
B ¦ Method Wank contamination. associated blank contains

anatyte at reportable level
Q « Estimated maximum possible contamination

4 of 4

Prepared by: TSB
Checked by. DJD


-------
Appendix D: Press Notices


-------
[This page is intentionally blank]


-------
^tD s***.

U.S. Environmental Protection Agency Region 7
Announces the Start of the Fourth
Five-Year Review
Syntex Facility Superfund Site
Verona, Lawrence County, Missouri

EPA has begun the fourth Five-Year Review at the Syntex Facility Superfund
site. The review is required by the Superfund law to make sure completed
cleanups continue to protect human health and the environment.

The third Five-Year Review and the Administrative Record are available at
the following locations during normal business hours:

Verona City Hall	EPA Region 7 Records Center

101 N. 3* Street	901 North 5th Street

Verona, Missouri	Kansas City, Kansas

Questions or requests for information can be submitted to:

Ben Washburn

Community Involvement Coordinator
U.S. EPA Region 7
901 N. Fifth St.

Kansas City, KS 66101
Toll free: (800)223-0425
Email: washburn.ben@epa.gov


-------
Appendix E: Site Inspection Checklist


-------
Site Inspection Checklist

1. SITE INFORMATION

Site name: Syntex Facility Superfund Site

Date of inspection: August 14,2012.

Location and Region: Verona, MO; Region 7

EPA ID: MOD007452154

Agency, office, or company leading the five-year
review: EPA Region 7 / USACE Kansas City District

Weather/temperature: Clear skies; -92° F

Remedy Includes: (Check all that apply)
E] Landfill cover/containment
~ Access controls
0 Institutional controls
0 Groundwater pump and treatment
0 Surface water collection and treatment
£3 Other: groundwater monitoring

0 Monitored natural attenuation
0 Groundwater containment
0 Vertical barrier walls

Attachments: 0 Inspection team roster attached

0 Site map attached

II. INTERVIEWS (Check all that apply)

1. O&M site manager

Name

Interviewed O at site 0 at office 0 by phone Phone no.
Problems, suggestions; 0 Report attached		

Title

Date

2. O&M staff

Name	^ Title

Interviewed 0 at site 0 at office 0 by phone Phone no. 	

Problems, suggestions; 0 Report attached	

Date

Five-year Review Report - 1


-------
I

3. Local regulatory authorities and response agencies (i.e., State and Tribal offices, emergency response
office, police department, office of public health or environmental health, zoning office, recorder of
deeds, or other city and county offices, etc.) Fill in all that apply.

Agency	

Contact	 	 		'	

Name Title Date Phone no.
Problems; suggestions; ~ Report attached 		

Agency .		

Contact		 	 	 	

Name	Title Date Phone no.

Problems; suggestions; ~ Report attached ¦ 	

Agency	

Contact	 ¦ 	 	 	

Name Title Date Phone no.
Problems; suggestions; Q Report attached 	

Agency	¦

Contact	 	 	 		

Name Title Date Phone no.
Problems; suggestions; Q Report attached 		' 	

4. Other interviews (optional) ~ Report attached.

Five-year Review Report - 2


-------
III. ON-SITE DOCUMENTS & RECORDS VERIFIED (Check all that apply)

1. O&M Documents

~	O&M manual ~ Readily available ~ Up to date QN/A

~	As-built drawings ~ Readily available ~ Up to date ~ N/A
13 Maintenance logs El Readily available ^ Up to date ~ N/A
Remarks: appeared complete and current.

2.

Site-Specific Health and Safety Plan ~ Readily available ~ Up to date £3 N/A
~ Contingency plan/emergency response plan ~ Readily available ~ Up to date ~ N/A
Remarks

3.

O&M and OSHA Training Records I~1 Readily available ~ Up to date ^ N/A
Remarks

4.

Permits and Service Agreements

~	Air discharge permit Q Readily available ~ Up to date 0 N/A

~	Effluent discharge ~ Readily available ~ Up to date ^ N/A

~	Waste disposal, POTW ~ Readily available . ~ Up to date 0N/A
I"! Other permits ~ Readily available f~l Ud to date 153 N/A
Remarks

5.

Gas Generation Records ~ Readily available ~ Up to date 13 ,N/A
Remarks

6.

Settlement Monument Records ~ Readily available ~ Up to date ^ N/A
Remarks: No settlement monuments exist. It is recommended that survey monuments be created to
allow monitoring of settlement, erosion, etc.

7.

Groundwater Monitoring Records ~ Readily available ~ Up to date ~ N/A
Remarks: Groundwater monitorine records were not readilv available. Thev are aooarentlv held until
requested. Trench Area ew monitorine data for the past 5 vears had not been provided to EPA: USACE
had to request these records from the Svntex environmental consultant C'Foth"1) and the release had to be



cleared throueh Svntex management.

8.

Leachate Extraction Records Q Readily available ~ Up to date El N/A
Remarks

9.

Discharge Compliance Records

~	Air ~ Readily available ~ Up to date E3 N/A

~	Water (effluent) ~ Readily available " ~ Up to date 13 N/A'
Remarks: implemented remedial actions do not generate discharges.

10.

Daily Access/Security Logs Q Readily available ~ Up to date El N/A
Remarks: the facility is sated and fenced . Access to the facility was sained throueh a remotelv
controlled eate. Facility visitor lops were not reviewed.

Five-year Review Report - 3


-------
		IV. O&M COSTS	

1. O&M Organization

~	State in-house	~ Contractor for State

~	PRP in-house	~ Contractor for PRP

~	Federal Facility in-house ~ Contractor for Federal Facility

£3 Other: Current facility owner (BCP Ingredients) is responsible for the maintenance of all remediated
areas except for the Trench Area, which is to be maintained by Syntex. O&M costs were not reviewed -
maintenance involves maintaining vegetative covers and proper drainage.

2. O&M Cost Records

~	Readily available ~ Up to date

~	Funding mechanism/agreement in place

Original O&M cost estimate	~ Breakdown attached

Total annual cost by year for review period if available

From



To





~ Breakdown attached



Date



Date

Total cost



From



To





~ Breakdown attached



Date



Date

Total cost



From



To





~ Breakdown attached



Date



Date

Total cost



From



To





~ Breakdown attached



Date



Date

. Total cost



From



To





~ Breakdown attached



Date



Date

Total cost



3. Unanticipated or Unusually High O&M Costs DuringReview Period

Describe costs and reasons: 	

V. ACCESS AND INSTITUTIONAL CONTROLS E Applicable ~ N/A

A. Fencing

1. Fencing damaged	~ Location shown on site map E Gates secured	~ N/A

Remarks: The facility is fenced and has a controlled access pate. Individual sites are generally marked
via metal cable strung at the perimeter of a given site upon which signage is hunp.

B. Other Access Restrictions	1

1. Signs and other security measures ( ~ Location shown on site map [UN/A

Remarks: signage is hung on the metal cable strung at the perimeter of a given site. It is noted that at the
Trench Area, an unauthorized individual was present at the Trench Area, apparently conducting hunting
related activities.	

Five-year Review Report - 4


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C. Institutional Controls (ICs)

I. Implementation and enforcement

Site conditions imply ICs not properly implemented	~ Yes ~ No (S3 N/A

Site conditions imply ICs not being fully enforced	Q Yes QNo 0N/A

Type of monitoring (e.g., self-reporting, drive by)	

Frequency			.

Responsible party/agency 		

Contact	

Name

Title



Date



Phone no.

Reporting.is up-to-date



~

Yes

~

No

~ N/A

Reports are verified by the lead agency



~

Yes

~

No

~ N/A

Specific requirements in deed or decision documents have been met

~

Yes

~

No

~ N/A

Violations have been reported



~

Yes

~

No

~ N/A

Other problems or suggestions: ~ Report attached
IC's are not identified by either the OUI or OU2 ROD.

Additional Information: The Syntex Verona site is listed on the "Missouri Registry of Confirmed
Abandoned or Uncontrolled Hazardous Waste Disposal Sites". Requirements include: deed notification
of site contamination; annual inspection conducted by MDNR; notice to buyer; change of use review;
notice to the State if property is sold; classifications of threat; and others.

2.

Adequacy ~ ICs are adequate ~ ICs are inadequate , ^ N/A
Remarks

D.

General

1. Vandalism/trespassing ~ Location shown on site map ~ No vandalism evident

Remarks: trespassing at the Trench Area was observed during the site inspection - an individual was
present.

2.

Land use changes on site ~ N/A

Remarks: no changes to site use was observed - the site is still in use as an industrial site. (

3.

Land use changes off site ~ N/A

Remarks: the city of Verona, MO, is still located adjacent to the Facility's east side. Per census data, no
appreciable change in population has occurred.

VI. GENERAL SITE CONDITIONS

A.

Roads ~ Applicable Q N/A

1. Roads damaged ~ Location shown on site map ~ Roads adequate £3 N/A
Remarks

Five-year Review Report - 5


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B. .Other Site Conditions

Remarks 	

VII. LANDFILL COVERS ^ Applicable ~ N/A

A. Landfill Surface: applicable to the following sites: Trench Area; Spill Area; Irrigation Area; Lagoon Area;
Slough Area; Burn Area. The "Grid Area" remedy is "stabilization" - maintenance of vegetation (no cap
placement).

1. Settlement (Low spots) ~ Location shown on site map ~ Settlement not evident
Areal extent	 Depih	

Remarks: areas of potential settlement and/or ponding were difficult to see; certain sites
such as the Burn Area and Lagoon Area could have areas where ponding might occur.

2. Cracks ~ Location shown on site map |3 Cracking not evident
Lengths	 Widths	 Depths	

Remarks: dessication cracks were not observed in areas having soil covers. The pavement at both the
Spill Area and PCB Cleanup Site appeared intact - no cracks were visible.

3.

Erosion
Areal extent

Remarks: no erosion was
indications of erosion.

~ Location shown on site map E3 Erosion not evident
Depth

observed; the sideslopes of the Trench Area were intact and also exhibited no

4.

Holes

Areal extent
Remarks

~ Location shown on site map K Holes not evident
Depth







5. Vegetative Cover	H Grass	~ Cover properly established ~ No signs of stress

Trees/Shrubs (indicate size and locations on a diagram)

Remarks: vegetative covers are present at: Irrigation Area: Lagoon Area: Bum Area: Slough: and
Trench Area. Vegetation consists of what appears to be grasses, weeds, and vegetation with deeper root
systems than grass (drought conditions have existed for at least 3-weeks prior to site visit') - grasses
exhibited drought induced stress (photographs clearly depict areas of dead grass that have left hare
patches of soin. Vegetation with longer root systems are not as impacted by the drought conditions.

I

6. Alternative Cover (armored rock, concrete, etc.)	QN/A

Remarks: Asphaltic pavement used as an alternative cover is employed at the Spill Area and PCB
cleanup area. Photographs depict this pavement as intact with no visible cracking.	

Five-year Review Report - 6


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7.

Bulges ~ Location shown on site map El Bulges not evident
Areal extent Height

Remarks .

8. . Wet Areas/Water Damage E Wet areas/water damage not evident

~	Wet areas ~ Location shown on site map Areal extent

~	Ponding Q Location shown on site map Areal extent

~	Seeps ~ Location shown on site map Areal extent

~	Soft subgrade ~ Location shown on site map Areal extent
Remarks

9.

Slope Instability ~ Slides ~ Location shown on site map 13 No evidence of slope instability

Areal extent

Remarks

B.

Benches ~ Applicable E3 N/A

(Horizontally constructed mounds of earth placed across a steep landfill side slope to interrupt the slope
in order to slow down the velocity of surface runoff and intercept and convey the runoff to a lined
channel.)

1. Flows Bypass Bench ~ Location shown on site map ~ N/A or okay
Remarks

2.

Bench Breached O Location shown on site map ~ N/A or okay
Remarks

3.

Bench Overtopped ~ Location shown on site map ~ N/A or okay
Remarks

a

Letdown Channels ~ Applicable El N/A

(Channel lined with erosion control mats, riprap, grout bags, or gabions that descend down the steep side
slope of the cover and will allow the runoff water collected by the benches to move off of the landfill
cover without creating erosion gullies.)

1. Settlement ~ Location shown on site map ~ No evidence of settlement
Areal extent Depth
Remarks

2.

Material Degradation ~ Location shown oh site map ~ No evidence of degradation

Material type . Areal extent

Remarks

3/

Erosion ~ Location shown on site map ~ No evidence of erosion

Areal extent Depth

Remarks

Five-year Review Report - 7


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4.

Undercutting ~ Location shown on site map ~ No evidence of undercutting

Areal extent Depth

Remarks.







5.

Obstructions TvDe ~ No obstructions

I-! Location shown on site maD Areal extent

Size

Remarks









6.

Excessive Vegetative Growth Tvoe

l~~l No evidence of excessive growth

O Vegetation in channels does not obstruct flow

PI Location shown on site map Areal extent

Remarks









D.

Cover Penetrations ~ Applicable ^3 N/A



1.

Gas Vents ~ Active ~ Passive

~	Properly secured/locked ~ Functioning ~ Routinely sampled

~	Evidence of leakage at penetration ~ Needs Maintenance

~	N/A ~

Remarks

Q Good condition







2.

Gas Monitoring Probes

~	Properly secured/locked ' ~ Functioning ~ Routinely sampled

~	Evidence of leakage at penetration ~ Needs Maintenance ~ N/A
Remarks

~ Good condition







3.

Monitoring Wells (within surface area of landfill)

~	Properly secured/locked ~ Functioning ~ Routinely sampled

~	Evidence of leakage at penetration ~ Needs Maintenance [UN/A
Remarks

~ Good condition







4.

Leachate Extraction Wells

~	Properly secured/locked ~ Functioning ~ Routinely sampled

~	Evidence of leakage at penetration ~ Needs Maintenance [UN/A
Remarks

~ Good condition







5.

Settlement Monuments ~ Located ~ Routinely surveyed |3 N/A

Remarks: it is recommended that the Trench Area be surveyed for the purpose of providing a baseline to

be used in assessing the condition of the Trench Area cover.

Five-year Review Report - 8


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V.

E.

Gas Collection and Treatment ~ Applicable ^N/A



1.

Gas Treatment Facilities

~ Flaring Q Thermal destruction ~ Collection for
G Good condition . ~ Needs Maintenance
Remarks

reuse







2.

Gas Collection Wells, Manifolds and Piping

I~1 Good condition ~ Needs Maintenance
Remarks









3.

Gas Monitoring Facilities (e.g., gas monitoring of adjacent homes or buildings)

~ Good condition ~ Needs Maintenance ~ N/A

Remarks







F.

Cover Drainage Layer ~ Applicable

EI N/A

1.

Outlet Pipes Inspected ~ Functioning
Remarks

~ N/A







2.

Outlet Rock Inspected ~ Functioning
Remarks

~ N/A







G.

Detention/Sedimentation Ponds ~ Applicable

En/a

1.

Siltation Areal extent Depth

~ N/A



(3 Siltation not evident
Remarks









2.

Erosion' Areal extent Depth





~ Erosion not evident
Remarks









3.

Outlet Works ~ Functioning ~ N/A
Remarks









4.

Dam ~ Functioning ~ N/A
Remarks







-

Five-year Review Report - 9


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H. Retaining Walls tZ3 Applicable ^N/A

1. Deformations ~ Location shown on site map ~ Deformation not evident
Horizontal displacement Vertical displacement
Rotational displacement
Remarks

2.

Degradation ~ Location shown on site map ~ Degradation not evident
Remarks

1.

Peri meter Ditches/Off-Site Discharge 0 Applicable ~ N/A

1. Siltation ~ Location shown on site map^ Siltation not evident
Areal extent Depth

Remarks: offsite drainage appears to be directed to the Slough; no evidence of siltation was present. This
would be expected considering the flat grade of the facility.

2.

Vegetative Growth ~ Location shown on site map ~ N/A
E Vegetation does not impede flow
Areal extent Type
Remarks

3.

Erosion ~ Location shown on site map ^ Erosion not evident

Areal extent Depth

Remarks

4.

Discharge Structure ~ Functioning £3 N/A
Remarks

VIII. VERTICAL BARRIER WALLS ~ Applicable 0N/A

1. Settlement ~ Location shown on site map ~ Settlement not evident
Areal extent Depth
Remarks

2.

Performance MonitorineType of monitoring
~ Performance not monitored

Frequency ~ Evidence of breaching

Head differential

Remarks

Five-year Review Report - 10


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IX. GROUND WATER/SURFACE WATER REMEDIES 0 Applicable ~ N/A

A. Groundwater Extraction Wells, Pumps, and Pipelines	Q Applicable ^ N/A

I. Pumps, Wellhead Plumbing, and Electrical

~ Good condition ~ All required wells properly operating ~ Needs Maintenance ~ N/A
Remarks ' 	

2. Extraction System Pipelines, Valves, Valve Boxes, and Other Appurtenances

~ Good condition ~ Needs Maintenance
Remarks	 '	

3. Spare Parts and Equipment

~ Readily available ~ Good condition ~ Requires upgrade ~ Needs to be provided
Remarks 		

B. Surface Water Collection Structures, Pumps, and Pipelines ~ Applicable E3 N/A

1. Collection Structures, Pumps, and Electrical

~ Good condition ~ Needs Maintenance
Remarks		

2. Surface Water Collection System Pipelines, Valves, Valve Boxes, and Other Appurtenances

~ Good condition	~ Needs Maintenance

Remarks	"	 	 	 	

3. Spare Parts and Equipment

~ Readily available ~ Good condition ~ Requires upgrade ~ Needs to be provided
Remarks		' 	

C. Treatment System	~ Applicable N/A

1. Treatment Train (Check components that apply)

~	Metals removal	H Oil/water separation	~ Bioremediation

~	Air stripping	Q Carbon adsorbers

~	Filters	' 			

~	Additive (e.g., chelation agent, flocculent)		.

~	Others	. 	•

~	Good condition	~ Needs Maintenance

~	Sampling ports properly marked and functional

~	Sampling/maintenance log displayed and up to date

~	Equipment properly identified

~	Quantity of groundwater treated annually		.

~	Quantity of surface water treated annually		

Remarks		

Five-year Review Report - 11


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2.

Electrical Enclosures and Panels (properly rated and functional)
~ N/A ~ Good condition Q Needs Maintenance
Remarks

3.

Tanks, Vaults, Storage Vessels

~ N/A ~ Good condition ~ Proper secondary containment ~ Needs Maintenance
Remarks

4.

Discharge Structure and Appurtenances

~ N/A ~ Good condition ~ Needs Maintenance
Remarks

5.

Treatment Building(s)

~	N/A ~ Good condition (esp. roof and doorways) ~ Needs repair

~	Chemicals and equipment properly stored
Remarks

6.

Monitoring Wells (pump and treatment remedy)

~	Properly secured/locked ~ Functioning ~ Routinely sampled ~ Good condition

~	All required wells located ~ Needs Maintenance ~ N/A
Remarks

D. Monitoring Data

1. Monitoring Data > ¦
~ Is routinely submitted on time ~ Is of acceptable quality '
Additional Information:. Syntex is currently implementing a "voluntary" groundwater monitoring
program. Four alluvial and four Trench Area wells are sampled.on an annual frequency. Apparently
Syntex has fulfilled their commitments under the OU1 and OU2 RODs. Trench Area monitoring of the
past 5-yrears was submitted upon request; Syntex is apparently not required to routinely submit acquired
data to EPA. Submitted data was in the form of summary tables -laboratory data package was not
included.

2.

Monitoring data suggests:

~ Groundwater plume is effectively contained ~ Contaminant concentrations are declining
Additional information: Monitored wells may not be appropriate for intercepting potential site releases.
Alluvial wells are screened ~ 5 to 15-feet below ground surface. Alluvial wells which previously yielded
contaminated samples are not part of the annual sampling program.

E.

Monitored Natural Attenuation

1. Monitoring Wells (natural attenuation remedy)

~ Properly secured/locked ~ Functioning ~ Routinely sampled ~ Good condition
Q All required wells located ~ Needs Maintenance ~ N/A
Remarks: locks are employed on compression well caps - steel protective casing caps are not locked
due to homets/wasps making nests in the protective casing; it is desired to have the ability to quickly
open the top of the protective casing and allow the sampler the ability to quickly spray any nesting
homets/wasps.

Five-year Review Report - 12


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		X. OTHER REMEDIES		 ¦

If there are remedies applied at the site which are nol covered above, attach an inspection sheet describing
the physical nature and condition of any facility associated with the remedy. An example would be soil
vapor extraction.

XI. OVERALL OBSERVATIONS

A. Implementation of the Remedy	.

Describe issues and observations relating to whether the remedy is effective and functioning as designed.
Begin with a brief statement of what the remedy is to accomplish (i.e., to contain contaminant plume,
minimize infiltration and gas emission, etc.).	\

Implemented remedies have the purpose of preventing human and wildlife exposures to soils
contaminated with dioxin at concentrations between 1 and 20 ppb: a "stabilization" remedy is also in-
place having the intent of minimizing off-site migration via runoff and of inhibiting air borne migration
of surface soil containing between I and 20 ppb dioxin. Except for drought induced stress which has
caused patches of grass to die, remediated areas appear to have had good vegetative covers. The issue
with the Lagoon. Burn, and Irrigation Areas is whether the "containment" remedy was properly
implemented - that a 1-foot cover of clean soil was placed over surface soil containing I to 20 ppb
dioxin. followed with placement of soil to support vegetation. Reviewed documents indicate that not all
surface soil indicated to contain dioxin at I to 20 ppb was covered with clean soil. Please refer to the
narrative of the Five-Year Review Report for additional information.		

B. Adequacy of O&IM

Describe issues and observations related to the implementation and scope of O&M procedures. In
particular, discuss their relationship to the current and long-term protectiveness of the remedy.
O&M procedures have the intent of maintaining the existence of vegetation on the Irrigation. Lagoon.
Slough. Burn. Grid and Trench Areas. Reviewed records did not provide a clear indication as to whether
sites were inspected subsequent to significant precipitation events to monitor for standing water. "Foth"
consultants stated that all sampled monitoring wells are measured to assess for sedimentation occurring
within the well. It appeared that O&M was keeping areas vegetated. It is noted that the vegetation
appears to be local vegetation: no specifications were cited in the QUI ROD regarding types of allowed
vegetation.	.	'

Five-year Review Report - 13


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C. Early Indicators of Potential Remedy Problems

Describe issues and observations such as. unexpected changes in the cost or scope of O&M or a high
frequency of unscheduled repairs, that suggest that the protectiveness of the remedy may be
compromised in the future.

No early indicators of early problems were observed,	

D. Opportunities for Optimization

Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy.
Groundwater monitoring is identified in the five-Year Review Report to be suspected of not being
adequate to intercept potential releases from areas addressed by the QUI ROD. In summary, shallow
alluvial monitoring wells having a maximum depth of 15-feet below ground surface are the only ones
currently being monitored - contamination was previously identified in alluvial wells screened at the
alluvial-bedrock interface. Regarding the Trench Area, the Five Year Review Report questions whether
the Trench Area monitoring well network is adequate to intercept potential releases from the Trench
Area. It also appears that samples obtained from monitoring well MW-17 may be indicating a potential
release from the Trench Area.

Five-year Review Report - 14


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Syntex Facility Superfund Site - Fourth Five Year Review

Site Inspection (14 AUG 2012)

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I

Appendix F: Photographs from Site inspection Visit


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[This page is intentionally blank]


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Photographs from Site Inspection Visit

Photo 1. Irrigation Area

Date: August 14, 2012

Description: Irrigation Area; photo taken from the northeast corner looking south. Photos 1 and 2 form
a panned image, panning to the west (towards Spring River


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Photographs from Site Inspection Visit

Photo 2. Irrigation Area

Date: August 14, 2014

Description: Irrigation Area; as viewed from the northeast corner and continuing with the panning
(started with Photo HI) to the east; evidence of stressed vegetation in the foreground.


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Photographs from Site Inspection Visit

Photo 3. Irrigation Area	Date: August 14, 2012

Description: Irrigation Area. Photo taken facing west, along the irrigation Area's north side. Perimeter
is marked with the depicted metal pipes from which a metal cable is hung. Photo also depicts the slight
transition from the elevated backfilled area to the adjacent ground surface.

Photo 4. Irrigation Area

Description: Typical warning sign at Irrigation Area.

Photographs from Site Inspection Visit


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Photo 5. Spill Area

Date: August 14, 2012

Description: Spill Area; view is towards the southwest. The Spill Area is defined by the yellow lines
painted on the pavement. Photos 6 and 7 are the result of panning to the west.


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Photographs from Site Inspection Visit

Photo 6. Spill Area

Date: August 14, 2012

Description: Spill Area, as taken from near the northeast comer, panning westward.


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Photographs from Site Inspection Visit

Date: August 14, 2012

Photo 7. Spill Area

• •"



Description: Spill Area; view is to the west. Note the survey benchmark located in the yellow semi-
circle. A series of these benchmarks are located along the perimeter. Photo 9 depicts a closeup of a
benchmark.


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Photographs from Site Inspection Visit

Photo 8. Spill Area	Date: August 14, 2014

Description: Spill Area viewed to the south.


-------
Photographs from Site Inspection Visit

Photo 9. Spill Area	Date: August 24, 2012

Description: Spill Area survey benchmark. These markers are distributed across the yellow perimeter
boundary that is painted on the pavement.


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Photographs from Site Inspection Visit

Photo 10. Spill Area	Dale: August 14, 2012

Description: Pavement of the Spill Area.

Photo 11. Spill Area	Date: August 14, 2012

Description: Closeup of the Spill Area pavement.

Photographs from Site Inspection Visit


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Photo 12. Lagoon Area

Date: August 14, 2012

Description: Lagoon Area; view is towards the southwest. This photo starts a panoramic series ending
with photo 14, panning clockwise to the north. East-side boundary of the Lagoon Area is marked by the
metal cable that is evident in the bottom left corner of the photo. It is apparent that a drainage runs
through the Lagoon Area. Sparse vegetative cover is in the foreground.


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Photographs from Site Inspection Visit

Photo 13. Lagoon Area

Date: August 14, 2012

Description: Lagoon Area, viewed towards the northwest. The mound in the background (back-right)
was not explained. Sparse vegetative cover is evident in the foreground.


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Photographs from Site Inspection Visit

Photo 14. Lagoon Area

Dale: August 14, 2012

H it*	«t ,«*•j ¦:.

_ '	r J ' V::r

; - i"'



Description: Lagoon Area, last photo of the panoramic sweep. View is to the north-northwest.

Photo 15. Lagoon Area





v

HI



¦f *
" ¦¦¦ /

¦"< , .i

sao; / •. ,i v ••

Description: Lagoon Area typical warning sign.

Photographs from Site Inspection Visit


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Photo 16. Slough Area

Date: August 14, 2012

Description: Slough Area, viewed towards the north.


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Photographs from Site Inspection Visit

Date: August 14, 2012

Photo 17. Slough Area

Description: Slough Area, viewed towards the north.


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Photographs from Site Inspection Visit

Photo 18. Trench Area

Date: August 14, 2012

Description: Trench Area; as viewed towards the northwest, from the south end of the Trench Area.
Vantage point is from the access road which dead-ends at the south end of the site. Stressed vegetation
present (lack of rain).


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Photographs from Site Inspection Visit

Photo 19.	Date: August 14, 2012



Description: Traversing the southern third of the Trench Area. Walking towards the north end. Photo
exhibits the diversity of vegetation present on the trench cover. Distressed brown areas due to lack of
water (drought conditions).


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Photographs from Site Inspection Visit

Photo 20.	Date: August 14, 2012

Description: Closcup of Trench Area cover vegetation. Bare patches are present.


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Photographs from Site Inspection Visit

Date: August 14. 2012

Photo 21. Trench Area

Description: Trench Area, view is to the southeast, oriented along the longitudinal alignment of the
Trench Area. Access roadway ends where the cars are parked (photo background). Stressed vegetation
present in the foreground (bare patches of soil observed, ref photo 18).


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Photographs from Site Inspection Visit

Photo 22. Trench Area	Date: August 14, 2012

Description: Trench Area; area of focus is the stressed vegetation that appears in photo 17. Bare
patches of soil arc present.


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Photographs from Site Inspection Visit

Photo 23. Trench Area

Description: Monitoring Well MW-20 located at the Trench Area (north end). No lock is used on the
exterior - this allows a sampler to quickly open the well head (wasps/hornets frequently make nests in
the well and fumbling with an exterior lock provides the wasps/hornets more time to attack the sampler).

Photographs from Site Inspection Visit


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Photo 24.	Dale: August 14, 2012

Description: Trench Area monitoring well MW-18

Photo. 25.	Date: August 14, 2012

Description: Monitoring Well MW-18

Photographs from Site Inspection Visit

Photo 26. Burn Area

Date: August 14, 2012


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Description: Burn Area, as viewed generally to the southwest.


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Photographs from Site Inspection Visit

Photos 27 & 28.	Date: August 14, 2012

Description: Hum Area; panoramic view which is generally towards the Spring River. Vegetation
distressed from lack of precipitation. The area docs not have an even grade.


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