October 9, 2009
PERFORMANCE-BASED REMEDY DECISION DOCUMENT
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RCRA CORRECTIVE ACTION for the 1991 EPA
ADMINISTRATIVE ORDER
FORMOSA PLASTICS CORPORATION (FPC-TEXAS)
POINT COMFORT, TEXAS
TXT490011293
THE PURPOSE OF THE
REMEDY DECISION
DOCUMENT IS TO:
Identify the proposed
corrective action objectives
for addressing groundwater,
surface water and soil
contamination and explain
the rationale for the
objectives;
Solicit public review and
comment on the corrective
action objectives and
information contained in the
Administrative Record;
Provide information on
how the public can be
involved in the remedy
decision process; and
Provide history and
background about the
facility and surrounding site.
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EPA ANNOUNCES CORRECTIVE ACTION
REMEDY DECISION DOCUMENT
I. INTRODUCTION
This performance-based remedy decision
document is issued by the Environmental
Protection Agency (EPA) as part of its public
participation responsibilities under the Resource
Conservation and Recovery Act (RCRA) for the
1991 EPA Administrative Order. Addressing
stakeholder concerns is critical to the success of
the final remedy. Terms in boldface are defined in
the glossary at the end of this remedy decision
document. The remedy decision document
summarizes information that can be found in
greater detail in the Administrative Record. A
discussion of the conceptual site model at FPC-
Tx and the surrounding area are presented in the
draft October 2009 Final Risk Management Plan
(RMP).
Ground water and soil sampling data collected to
determine the extent of contamination are included
in the Administrative Record. The development
and evaluation of corrective action objectives
(CAO's) are presented in this document, and also
presented in the RMP. It is EPA's expectation to
base the remedy decision on the attainment of
corrective action objectives (Section IV), with the
assurance that the remediation goals are met
through required reporting on remedy effectiveness
(Section V). The performance-based approach to
remedy selection will enhance long-term
sustainability by supplanting the traditional
approach of selecting a technology as a final
remedy.
COMMUNITY PARTICIPATION
EPA encourages the public to review the
Administrative Record in order to gain a more
comprehensive understanding of the RCRA
investigation and interim measures activities that
have been conducted at the Facility. The
Administrative Record is available for review at the
EPA Dallas office, or at the following location:
Point Comfort Branch Library
1 Lamar Street
Point Comfort, Texas
(361) 987-2954
Tues - Thurs - 10:30 a.m. to 6:00 p.m.
Friday - 10:00 a.m. to 3:00 p.m
Saturday - 9:00 am - 12:00 noon.
EPA welcomes public comment on the corrective
action objectives described in this document.
Comments on the information supporting the
corrective action objectives are an important
contribution to the remedy implementation process.
EPA may modify the proposed CAOs based on
new and/or substantive information presented to
EPA through public comments.
The public comment period for the remedy decision
document begins October 15, 2009, and ends on
November 30, 2009. During the public comment
period, written comments must be postmarked by
November 30, 2009 and submitted to:
U.S. Environmental Protection Agency
Attention: Nancy Fagan, Mail Code 6PD-O
1445 Ross Avenue
Dallas, Texas 75202-2733
EPA will also accept comments sent via email
received by November 30, 2009. EPA will also
hold a public meeting beginning at 7p.m., October
15, 2009, to inform the community about this
proposed remedy approach and obtain their
comments. The public meeting will be held at the
following location:
Calhoun High School
201 Sandcrab Blvd.
Port Lavaca, Texas
(361) 552-3775
EPA will address all comments received during the
public comment period in the Final Decision and
Response to Comments document (RTC). The
RTC will explain EPA's rationale for the remedy
approach to address contamination problems at
FPC-Tx. Based upon public comment, new
information, or a re-evaluation of existing
information, any significant differences from this
remedy decision document will be explained in the
RTC. The RTC will be incorporated into the
Administrative Record and made available to the
public in the information repositories.
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The final remedy selected by EPA will be
implemented through the Corrective Measure
Implementation (CMI) phase in the corrective action
process, as outlined in the Administrative Order
(Order) [Docket No. VI-001 (h)-90-H 3008(h)]
issued to FPC-Tx on February 27, 1991.
Discussions are on-going with the Texas
Commission on Environmental Quality (TCEQ)
to conduct corrective measures under TCEQ
jurisdiction after this decision is finalized.
The site constituents originally determined from
the waste stream are the following volatile organic
compounds (VOCs):
Ethylene dichloride or EDC (1,2-dichloroethane
or 1,2-DCA)
1,1-dichloroethane(1,1-DCA)
1,1-dichloroethene(1,1-DCE)
Cis-1,2 dichloroethene
Trichloroethene (TCE)
Tetrachloroethene (PCE)
1,1,2-trichloroethene
1,1,2,2-tetrachloroethane
1,2-dichloroethene
Trans-1,2 dichloroethene
Trans-1,4-dichloro-2-butene
Chloroform
Chlorobenzene
Ethylbenzene
Toluene
Xylene
Benzene; and
Vinyl chloride.
The list of constituents has been narrowed down
based on the confirmed set of VOCs found in
groundwater and soils in concentrations over the
laboratory reporting limit. The Interim Measures
Implementation Report (1/29/93) indicated dioxins
and furans were not detected above the laboratory
limits from any of the samples collected during the
RCRA Facility Investigation (RFI). Semivolatile
organics (SVOCs) and metals were sampled from
1993 until 2002. After an EPA review of sampling
results, SVOCs and metals were removed from the
sampling program (see Section II.F).
A. Site Description
Formosa Plastics Corporation, Texas (FPC-Tx)
owns and operates a chemical manufacturing
facility in Point Comfort, Texas. This facility is
located in Calhoun County along State Highway 35
and Farm to Market Road (FM) 1593, adjacent to
Lavaca Bay. FPC-Tx manufactures vinyl chloride
monomer (VCM) and ethylene dichloride (EDC) at
the facility, which are used to produce polyvinyl
chloride (PVC) resin.
In accordance with the U.S. Environmental
Protection Agency (EPA) Administrative Order on
Consent (Order) dated February 27, 1991 (EPA I.D.
No. TXT490011293), FPC-Tx has undertaken
measures to characterize and remediate soil and
groundwater affected by site constituents at the
Point Comfort facility.
The EPA 1991 Order is relevant to the area of the
FPC-Tx plant where historical releases occurred
from the Waste Water Treatment (WWT) area that
operated from 1983 to 1993 and various units
located in the Vinyl Chloride Monomer (VCM) plant.
The former Brookings property (now owned by
FPC-Tx) south of Hwy 35 was also investigated
under the EPA Order. Remediation efforts for other
portions of the plant (including the expansion
areas) are conducted under the jurisdiction of the
TCEQ (Figure 1).
B. Regulatory History
Under the terms of the Order FPC-Tx is required to
complete the following actions: Task I) conduct an
Accelerated RCRA Facility Investigation (ARFI) to
install additional wells and conduct additional
sampling for determining nature and extent of
contamination; Task II) conduct interim measures
(IM), as necessary to control offsite migration of
contaminated groundwater; Task III) conduct an
RCRA Facility Investigation (RFI) to determine the
nature and extent of contamination resulting from
past facility operations; Task IV) perform a
Corrective Measures Study (CMS) to evaluate the
various clean-up alternatives; and Task V) submit
II. FACILITY BACKGROUND
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Figure 1
Formosa
Plastics
Pre-1990
Property
(Red
Boundary)
ALCOA
Former
Brookings
Property
Cox
Creek
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to the EPA a Corrective Measures Implementation
(CMI) Program Plan concurrently with the final
CMS. On April 24, 2009, EPA issued a letter to
FPC-Tx requesting the submittal of a Risk
Management Plan (RMP) in lieu of a final CMS.
The RMP sets forth the performance-based
approach of getting media-specific corrective action
objectives in place that FPC-Tx must meet to be
protective of human health and the environment.
C. Closure and Site Investigation History
A RCRA Facility Assessment (RFA) was conducted
by an EPA contractor (PRC Environmental
Management) in July 1990. In the RFA, 35 solid
waste management units (SWMUs) were
identified (Figure 2). In the early 1990's, the Used
Oil Storage Area (SWMU #31) was taken out of
service, and three EDC storage tanks VT-763A
(SWMU 24), VT-763B (SWMU 25), and VT-102
(SWMU 26) were closed.
FPC-Tx has completed activities under the Interim
Measures phase of Work to be Performed, as
described in Section VI of the 1991 EPA Order.
The Interim Measures Plan (IMP) was submitted to
EPA to characterize and remediate affected soils
and groundwater identified in the Order. The IMP
was approved by the EPA on May 13, 1991.
The interim measure for remediation of
groundwater was a system which recovered and
treated groundwater contaminated with volatile
organics. The recovery of groundwater by pumping
creates a cone of depression in the water bearing
zone which can result in the hydraulic containment
of dissolved contaminants. The IM system of using
recovery wells to pump affected groundwater from
two areas in the facility commenced operations on
May 13, 1993. Groundwater data from the
Supplemental RFI report confirms the presence of
two groundwater plumes associated with the former
wastewater treatment plant and the current VCM
plant.
The work performed as part of the RFI phase has
been conducted from 1991 until the present. On
January 8, 2007 EPA approved the RFI.
Groundwater sampling activities are documented in
quarterly groundwater reports. Development of the
conceptual site model began after the RFI approval
and is presented in the final RMP. Work completed
at FPC-Tx according to the Order is documented in
the following reports:
Description of Current Conditions Report (Mar
1991)
RFI Workplan (October 1991)
Accelerated RCRA Facility Investigation
Assessment, (Geraghty & Miller, Inc. Dec.1991)
Interim RCRA Facility Investigation Assessment,
(Engineering Science, 1992)
Closure/Corrective Measures Report for Tank
VT-763A&B (Sept. 1992)
WWT System Surface Impoundments Closure
Plan (Mar 1994)
Supplemental RCRA Facility Investigation
Workplan (Environeering, 1994)
Interim Measures (IM) Workplan (Environeering
1994)
Construction Quality Assurance (CQA) Plan
Interim Measures (Environeering 1994)
Interim Measure Implementation Report
(Environeering 1994)
Groundwater Quality Assessment Plan
(Environeering 1994)
Cone Penetrometer Testing (CPT) Fenceline
Sampling Event (C-K Associates 1995)
Aquifer Tests Report (C-K Associates, 1995)
Supplemental RCRA Facility Investigation (C-K
Associates June 1995, revised May 1998)
VCM Fenceline Investigation (Radian
International 1999)
Proposed Modification, IM Groundwater
Monitoring (MFG 2001)
Summary of Metals Analyses 2002 Groundwater
well sampling recommendation (MFG 2002)
Stage 1 Groundwater Investigation Report,
Former Brookings Property (PBW2007)
Current Conditions Technical Memorandum
(TetraTech 2008)
Final Risk Management Plan (October 2009)
Former Waste Water Treatment (WWT) SWMUs
- Current Status
The former WWT area operated from 1983 to 1993.
SWMUs that are located in the WWT area include:
SWMU #2 Equalization Basin,
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Figure 2
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SWMU #3 Surge Basin, SWMU #4 Emergency
Basin, SWMU #5 Andco Basin, SWMU #6 Aeration
Basin, and SWMU #7 the Sludge Drying Beds. All
ancillary equipment for SWMUs in this area have
been isolated and all solids have been removed for
recycling or disposal. When SWMU #4 was
operational, it received some EDC and VCM-
contaminated wastewater from the VCM process
upsets. The Surge Basin and Emergency Basin
are considered source areas for groundwater
contamination at the WWT area.
VCM Area SWMUs - Current Status
The VCM area is an operational area of the facility
located west of the former WWT area. The Storm
Water Basin (SWMU #1) was in continuous
operation from 1983 to 1993. All ancillary
equipment has been isolated and all solids have
been removed for recycling or disposal. The basin
was constructed of four-inch-thick concrete
underlain by a 6-mil polyethylene liner and
compacted backfill. This basin received
contaminated run-off from all plant process areas,
washdown water, blast cleaning water, column
steam bumping water and water from cleaning
chemical spills in the process area. The primary
constituent present was EDC. This SWMU is
considered a potential source for the contaminated
groundwater in the VCM plant. As reported in the
1998 RFI, FPC-Tx made changes to reduce the
amount of contaminated water entering the basin
when signs of the structural integrity were in
question. Some changes included the construction
of the PVC settling pits (SWMU #17) at the PVC
processing area to remove PVC from the
stormwater sewer system, and installing a second
EDC stripping column to treat process and storm
water runoff in the VCM processing area. In
addition, FPC-Tx removed an underground storm
water pipeline connected to the Storm Water basin
and disposed of contaminated soils off-site.
EPA conducted a meeting at the FPC-Tx site June
10-12, 2008 to review current status of SWMUs
and all surface soil and groundwater data
associated with each SWMU. It was determined
that 20 of the 35 SWMUs could be closed with no
further corrective actions (NFA) based on data
comparisons to the TCEQ Texas Risk Reduction
Program (TRRP) screening levels for an industrial
scenario. The WWT SWMUs retained for
corrective measures are:
#2 Equalization Basin
#3 Surge Basin
#4 Emergency Basin
#5 Andco Basin
#6 Aeration Basin
#7 Sludge Drying Beds
The VCM area SWMUs retained for corrective
measures are:
#1 Storm Water Basin
#17 PVC Settling Pits
#19 Incinerator area
#21/22/23 Holding Pit, Inactive Sewer Pump and
VCM Waste Pit
#24/#25 closed EDC storage tank area
#35 Secondary containment tank area
Of the SWMUs retained for corrective measures,
some SWMUs were grouped according to the need
for further action to address groundwater issues
only. The results of the review are summarized in
Appendix A of this document.
D. Site Geology and Hydrogeology
FPC-Tx is underlain by the Beaumont Formation,
which is made up of several hundred feet of
dominantly fine-grained silt and clay, with
sequences of interbedded fine sand and silt units.
The upper groundwater saturated units have
been designated as Zones P, A, B, and C in
descending order. Zone P represents the
uppermost saturated discontinuous silty sand that
forms a perched water table that is laterally
discontinuous. It is important to note that the site
geology and hydrogeology conditions vary from the
VCM area to the WWT area (which is characteristic
of fluvial depositional environments).
VCM Plant Area - At ground surface in the
VCM plant area, a stiff to very stiff, brown silty clay
and hard reddish brown clay with iron staining and
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ferrous nodules is encountered to a depth of about
18 feet below ground surface (bgs), interbedded
with a seam of silty sand about one foot thick. Well
P-13 is constructed with a screen at this thin sand
seam which represents the uppermost water-
bearing unit. Silty clay underlies this sand seam to
a depth of about 25 to 27 feet bgs where a silty
sand unit about 20 feet thick is encountered. This
unit is underlain by a hard gray clay to a depth of
about 70 feet bgs and is about 23 feet thick. A firm
brown fine-grained sand that ranges in thickness
from about 14 feet to 30 feet thick is encountered
below the clay.
WWT Area - At ground surface in the WWT area,
a dark gray to olive gray and red-brown, silty clay is
encountered to a depth of about 16 feet bgs,
interbedded with a one-to two -foot seam of red-
brown silty sand. Wells P-20 and P-47 are
screened across this thin sand seam. This sand
seam is underlain by a very hard olive-gray to red-
brown mottled clay to a depth of 63 feet bgs. A
brown, very fine-grained silty sand about 14 feet in
thickness is encountered at this depth.
As noted at the ALCOA site adjacent to the south,
there are shallow sand lenses in the Beaumont
Clay hydraulically connected to shallow silty clays.
It is expected that the shallow saturated zones
transcend the various facies changes from silty
sands to silty clays; hence the need to describe the
saturated zones as Zones A, B, and C. Figure 3
depicts a representation of facies changes typical
of the depositional environment near the FPC-Tx
site.
It is not known if the Zones described at the
ALCOA site are the same hydrogeologic units at
the FPC-Tx site. Another characteristic worthy of
noting is that the shallow silty clays in some areas
have very low hydraulic conductivity (8.0 x 10"8
cm/sec in sample P-38 at 18-20 feet bgs) and high
porosity (50%). Since the presence of product or
"free phase" has not been detected in the
monitoring wells, it can be assumed that
contaminants are adsorbed in the shallow silty
clays (mudstones).
Figure 3
Typical Coastal Fluvial Depositional Sequence
Fine grained = mudstone facies
Medium grained = siltstone facies
Coarse grained = sandstone facies
The following description of the local hydrogeology
is taken from the 1999 Remedial Investigation (Rl)
report for the neighboring ALCOA Superfund site:
Zone A consists mostly of interbedded sand, silt, and
clay sediments characteristic of overbank flood basin
depositional environments. Sand/silt strata also occur in
Zone A as sublinear, branching sand-rich bodies, which
are representative of fluvial-deltaic and channel
deposits. Zone A typically occurs at an elevation of
approximately 5 to 0 ft mean sea level (msl). Zone A is
overlain and underlain by the Beaumont Clay. Zone B
is separated from Zone A by the Beaumont Clay and
includes strata consisting of fining-upward or massive
sequences of silty sand to well-graded sand, as well as
some finer grained sediments. Zone B sand strata are
characteristic of dominantly fluvial depositional
environments, with adjacent floodbasin and
interdistributary deposits. Zone B is typically
encountered at elevations of -20 to -30 ft msl. The
thickness of Zone B sand and silt sequences ranges
from less than 1 foot to greater than 20 feet. Zone B
occurs below sea level and groundwater occurs under
confined conditions. Zone C is separated from Zone B
by the Beaumont Clay and is the deepest transmissive
zone defined at the Plant. A groundwater "mounding
effect" exists beneath the ALCOA Process Lakes and
Bauxite Residue Lakes, with the potentiometric surface
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elevation decreasing radially away from the Lake
Complex. Groundwater discharges to Lavaca Bay and
the upper reach of Cox Lake under natural conditions.
Generally, the vertical gradients between Zones A and B
are downward. Upward hydraulic gradients from Zone B
to Zone A were observed near shoreline areas away
from the ALCOA process lakes. Vertical hydraulic
gradients between Zone B and Zone C tended to follow
the same pattern (i.e., downward in the interior and new
process lake areas and upward near the shoreline.)
Zone A groundwater at the Northern Perimeter (of
ALCOA) moves to the north toward the city of Point
Comfort (and subsequently to Lavaca Bay) and the
Formosa Plastics facility (and subsequently to Cox
Creek/Lake). Groundwater in Zone A flows offsite
toward Cox Lake and Cox Creek. Groundwater flowing
horizontally in Zone B also discharges into the Bay
System. In the ALCOA ship/barge channel and turning
basin, direct discharge occurs where the deep channel
cut (bottom elevation of approximately -40 ft msl)
intercepts Zone B. Elsewhere, potentiometric data
confirm that groundwater from Zone B discharges
offshore upward into shallower strata and, thus, to the
Bay System. Zone B groundwater at the Northern
Perimeter (of ALCOA) similar to Zone A flow moves to
the north toward the city of Point Comfort and the
Formosa Plastics facility. Near the northeastern
perimeter, groundwater in Zone B flows offsite toward
Cox Lake and Cox Creek. Near the southeastern
perimeter of ALCOA, Zone B groundwater may
discharge into Cox Marsh and/or the original channel of
Cox Creek.
The description above is pertinent to the
understanding of groundwater flow in the general
area and the effects on groundwater flow beneath
the FPC-Tx facility. The Process and Bauxite
Residue Lakes have a large volume of wetted clay
that create the "mounding effect" on Zone A and
Zone B, affecting the hydraulic gradients as
described.
F. Interim Measures (IM) Groundwater
Recovery System
FPC-Tx initiated an expedited interim groundwater
recovery and remediation program at the Point
Comfort facility while awaiting completion and
approval of the RCRA Facility Investigation (RFI)
and final corrective action plan. This interim
groundwater recovery and remediation program
was implemented in accordance with the approved
Expedited Interim Measures Groundwater
Remediation Plan (IMP) dated January 23, 1992.
The IMP required quarterly sampling and reporting
on the progress and effectiveness of the interim
measures. Quarterly monitoring has been
conducted and reports have been submitted to the
EPA with groundwater data from 1993 until the
present. EPA conducted split sampling of
groundwater as part of the EPA oversight of the
Order from 1993 until 1998.
In October 2001, FPC-Tx proposed modifications to
the groundwater-monitoring program. EPA
reviewed the proposed modifications and
responded with comments on November 15, 2001.
An agreement on the proposed modifications was
reached via conference call between FPC-Tx and
EPA on March 5, 2002. MFG, Inc. (Formosa's
contractor) prepared a new Groundwater Sampling
and Analyses Plan (GWSAP) based on the
approved modifications to the IMP. Changes to the
existing program included:
A modified analytical program eliminating
analyses for total organic carbon (TOC) and
semivolatile organic compounds (SVOCs) and
reducing the number of metals analyses;
A modified conceptual model of the facility
including four water bearing zones as opposed
to the two units described in previous
documents;
A change from traditional sampling with inertial
pumps to the EPA-approved method of low-
flow sampling;
A reduced sampling frequency from quarterly to
semi-annually with the exception of wells
located along the down-gradient edge of the
plume near the property boundary; and
A modified and condensed quarterly report.
FPC-Tx implemented the modified program in
2002. Based on the groundwater monitoring
program completed in 2002, FPC-Tx proposed
additional modifications to the program. These
changes consisted of the following:
Metals analyses were eliminated as part of the
interim measures monitoring program;
All groundwater monitoring wells will be
sampled in the first quarter of each year; and
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Monitoring wells located near the down-gradient
property boundary, near the perimeter of the
known plume, and located at locations critical to
monitor potential vertical migration of impacted
groundwaterwill be sampled every quarter.
EPA verbally approved these additional
modifications via conference call on December 31,
2002. FPC-Tx implemented the additional
modifications to the program in 2003. FPC-Tx
received formal written acceptance in an EPA letter
dated January 8, 2007. Modifications to the
groundwater program were a result of a detailed
evaluation of the 10 quarters of data from 1st
quarter 1999 to 2nd quarter 2001. Detected
concentrations of semivolatiles were below TRRP
Tier 1 Class 2 groundwater ingestion protective
concentration levels. Metals analyses were
eliminated because samples with detectable
concentrations of antimony, arsenic, beryllium, lead
and thallium were detected in less than 5% of the
samples collected.
The interim measures groundwater recovery and
remediation system at FPC-Tx consists of six
recovery wells (RS-1, RS-2, RS-3, RS-4, RS-5, and
RS-6) in Zone A, two recovery wells in Zone B (RS-
1 and RD-3), and one recovery well located in Zone
C Upper (RD-1). Based on well construction logs,
recovery well RS-1 appears to be screened across
both Zone A and Zone B. The recovery wells are
equipped with pneumatic or electric pumps that
pump groundwater to a dedicated steam stripper.
Recovered groundwater processed through the
steam stripper is discharged through the plant
permitted wastewater Outfall 001.
Outfall 001 discharges via pipeline to Lavaca
Bay/Chocolate Bay in segment 2453 of the Bays
and Estuaries. Formosa operates other outfalls
(002 - 012) as described in their TPDES permit
(WQ 0002436000).
The existing steam air stripper used in the IM
groundwater treatment is located in the VCM plant.
The steam stripper units are designed to separate
and recover ethylene dichloride (EDC or 1,2 DCA)
from an EDC-saturated water process stream. In
the early stages of the Interim Measures, the water
contained near saturation levels of EDC ranging
from about 4,000 to 9,000 mg/L with lower levels of
other VOCs. Recent quarterly reports indicate a
much lower EDC ranges (from 10 - 280 mg/L).
Actual performance of the steam stripper at the
FPC-Tx facility is determined by analyzing samples
from the feed water entering the stripper (influent)
and comparing with samples exiting the steam
stripper (effluent). This system is a closed-loop
system which means that steam condensate is
collected and sampled. EPA approved the
process of treating groundwater using a steam air
stripper because of the extensive experience FPC-
Tx has with steam stripping, the availability of the
equipment at the facility and that FPC-Tx could
recover EDC for reuse as a product. Compliance
records of upset conditions are kept to record high
levels of EDC when they enter the stripper
overloading the stripping capacity of the unit.
Treated groundwater that does not comply is re-
circulated through the stripper for additional
treatment.
FPC-Tx plant areas under the EPA Order are
described in the sections below. Corrective actions
on other plant areas north of the VCM area are
under the jurisdiction of the Texas Commission on
Environmental Quality (TCEQ).
Former Waste Water Treatment Area
Currently, there are two Zone A recovery wells
operating in the WWT area, RS-2 and RS-6. Zone
A monitoring wells P-18, P-56 and P-57, located at
the down-gradient edge of the monitored area,
each had detectable concentrations of VOC in the
third quarter 2008. Although groundwater in the
vicinity of monitoring wells P-56 and P-57 may be
controlled by recovery well RS-6, monitoring well P-
18 is likely located beyond the capture zone
created by RS-6 and RS-2. There are no recovery
wells operating in the deeper water bearing zones
in the WWT area. Groundwater samples from two
monitoring wells in Zone B (D-32 and D-33)
contained VOC concentrations in excess of the
detection limit during the 2008 third quarter
sampling event.
VCM Area
The current recovery system in the VCM area
includes recovery wells in Zone A, Zone B, and
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Zone C. Based on a review of the third quarter
2008 potentiometric and analytical data, the
following conclusions can be reached:
Zone P - Zone P monitoring wells are screened in
the perched water table. There are no recovery
wells located in Zone P which is hydraulically
connected to Zone A.
Zone A - Recovery wells RS-4 and RS-5, located
near the down-gradient property boundary,
represent the down-gradient control of the Zone A
EDC plume. FPC-Tx completed a Zone A
groundwater investigation of the property south of
State Highway 35 in 2007 and no VOCs were
detected in Zone A.
Zone B - The down-gradient extent of the EDC
plume in Zone B does not appear to be adequately
defined between recovery well RS-1 and the
property boundary, thus it is not possible to
determine if recovery well RS-1 is adequate to
control horizontal migration of the plume in this
zone.
Zone C - Recovery well RD-1 is a highly productive
well with a significant cone-of-depression.
Horizontal migration of the EDC plume in this area
may be adequately controlled by this well; however,
VOC concentrations at D-41 increased during the
last three quarters prior to third quarter 2008. This
could be an indication of horizontal migration
beyond the control of RD-1 or the vertical migration
may indicate that the existing groundwater recovery
system in the shallower zones may not be
adequate to control the vertical migration of the
EDC plume into the lower water-bearing zones.
G. Soil Contamination
Contaminated soil associated with the release
areas (the VCM area and the former WWT area)
were evaluated as part of the RFI and SRFI. The
1992 and 1994 closure reports describe soil
removal efforts associated with each SWMU. EPA
requested FPC-Tx to review this data to determine
an appropriate soil remediation strategy for the
corrective measure in these areas. FPC-Tx
submitted a Current Conditions Technical
Memorandum final report in August 2008 to
evaluate the volume of unsaturated soils (soil
above the groundwater table) compared to the
volume of soil that is below the groundwater table
(saturated soil). Saturated soils are typically most
economically handled via groundwater treatment
and management strategies. Review of the data,
as reported in the CCTM, revealed soil samples
collected from the interior of the Surge and
Emergency Basins (in the WWT area) are
representative of unsaturated soil conditions. The
thickness of unsaturated soil beneath the basins is
estimated to range between 2 and 6 feet. The
volume of unsaturated soil was estimated at 2,400
cubic yards. A pilot treatability study (Section V.F.)
will be conducted in the area of unsaturated soils to
determine if contaminants can be treated insitu as
opposed to conducting a removal and offsite
disposal.
H. Former Brookings Property
The 335-acre tract of land south of State Hwy 35,
formerly owned by the Brookings family was
purchased by FPC-Tx on October 24, 2005.
Historical groundwater investigation data indicated
that impacted groundwater may have migrated
southeast of Hwy 35. FPC-Tx conducted an
investigation in August through October 2007 to
determine the extent of the groundwater
contamination in Zone A (to a depth of 30 feet) and
determine the hydraulic characteristics of Zone A
near recovery well RS-6. The following activities
were conducted during this investigation:
Review of historical aerial photographs
High resolution resistivity survey (3,950 linear
feet)
Eighteen direct push borings
Installation of temporary wells at boring locations
for groundwater sampling
Groundwater sample analysis for VOCs
Step-draw down test and pumping test at RS-6.
Conclusions from this investigation revealed the
presence of a relatively thick sand channel near
well RS-4 (shown in Figure 3 of the October 2007
Groundwater Investigation Report- Former
Brookings Property); however, subsequent
resistivity lines to the south on the former
Brookings property reveal that the prominent sand
channel lessens in sand and moisture content,
11
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indicative of a typical fades change from a silty
sand to a silty clay. There is no indication that a
significant sand channel exists to the south of RS-
6. EDC was not detected in any Zone A
groundwater samples collected from the former
Brookings property, however, contaminants may
exist in Zone B or C. Compliance wells will be
installed for each zone to delineate the
groundwater compliance areas (See Section IV,
CAO 1). If contaminants are found in the B and/or
C Zone, the point of compliance may be Cox Creek
to ensure that contaminants in groundwater are not
released to Cox Creek.
III. SUMMARY OF SITE RISK
This section provides a summary of the human
health and environmental risks associated with
releases to soil, groundwater, and surface water at
FPC-Tx. Contaminants in soil and ground water
were screened relative to a target carcinogenic risk
of 1E-05 (1 in 100,000 cancer risk). The
evaluations provide the basis for taking action and
identify the contaminants and exposure pathways
that need to be addressed. Exposure pathways
were analyzed as part of the CCTM report of
August 2008, and the conceptual site model is
provided in the final Risk Management Plan
(October 2009).
Surface/Subsurface Soil Exposure pathways
In general, there are two potentially complete
exposure pathways associated with impacted soil:
1) direct contact with impacted soil during
subsurface construction activities, and 2) leaching
of chemicals of concern from impacted soil to
groundwater and subsequent potential offsite
receptor exposure to impacted groundwater. The
TRRP screening tables define protective
concentration levels (PCLs) for each route of
exposure. [TotSoilComb is the TRRP screening value
for direct exposure, and GwSoil|ng is the screening
value for the leaching to groundwater exposure
pathway]. Chemicals of concern (COCs) at six
SWMUs exceeded the soil screening value for the
direct contact exposure pathway (TotSoilComb)- (See
Section IV, CAO 3). COCs at nine SWMUs were
reported at concentrations less than the direct
exposure value, but exceeded the PCL for the
protection of groundwater. (Section IV;CAO 3).
Table 1: Soil COCs and TRRP PCLs
Soil COC
1,2-DCAorEDC
1,1- DCA
1,1-dichloroethylene
Cis-1 ,2-
dichloroethylene
Trans-1 ,2-
dichloroethylene
chlorobenzene
tetrachloroethylene
1,1,2-TCA
trichloroethylene
Vinyl chloride
benzene
chloroform
I0to -i
5>ONcomb
22 ppm
8200 ppm
6400 ppm
6400 ppm
1200 ppm
1000 ppm
360 ppm
35 ppm
310 ppm
15 ppm
180 ppm
26 ppm
CjWo«.'l
SOllmg
0.014 ppm
55 ppm
0.05 ppm
0.25 ppm
0.49 ppm
1.1 ppm
0.050 ppm
0 020 ppm
0.034 ppm
0.022 ppm
0.026 ppm
3.0 ppm
Groundwater Exposure Pathways
Groundwater contaminant plumes are located at
the VCM plant and at the former WWT area.
Concentrations of contaminants in groundwater are
reported above the maximum contaminant limits
(MCL) for drinking water. Chemicals of concern can
leach from saturated and unsaturated soils to
shallow Zone A groundwater and subsequently to
deeper water-bearing Zones B and C. There is no
groundwater use on site; however, both shallow
and deeper groundwater could potentially migrate
offsite. The down-gradient property located
between State Hwy 35 and Cox Creek was
purchased by FPC-Tx in 2005 (former Brookings
property). Three wells on this property are
classified as oil field service wells, and the fourth
well is classified as an industrial use well. In
February 1995 the City of Point Comfort began
using surface water from nearby Lake Texana.
Chemicals of concern retained for groundwater
monitoring are included in Table 2. FPC conducted
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a groundwater well survey indicating well locations
and well usages for offsite wells within a 1.5-mile
radius. The results are in the October 2009 RMP
report. The EPA is also conducting a residential
well survey for offsite users of local groundwater in
the Fall of 2009.
Table 2: Groundwater COCs and MCLs(ppb)
1,2-DCAorEDC
1,1- DCA
1,1, DCE
Trans-1,2-DCE
Cis-1,2-DCE
Vinyl chloride
chloroform
benzene
TCE
1,1,2-TCA
Tetrachloroethene
(PCE)
5.0
No MCL established
7.0
100.0
70.0
2.0
80.0
5.0
5.0
5.0
5.0
Surface Water and Sediment
Surface water, sediments and organisms were
collected and tested as part of the Geochemical
and Environmental Research Group (GERG) of
Texas A&M University, August 1990. This report
indicated that volatile organic compounds (VOCs)
were found in low concentrations in the surface
water and sediment samples. Impacted
groundwater could affect Cox Creek if shallow
groundwater discharges to Cox Creek. FPC-Tx
installed stream gauges along Cox Creek to collect
stream elevation data in 2008. Preliminary stream
elevation data indicates a higher surface water
level at downgradient locations on the former
Brooking property as compared to the shallow
groundwater elevations at FPC-Tx. This could
indicate the dam at Cox Creek (near the ALCOA
site) is causing a reversal of the hydraulic gradient
back towards FPC-Tx and further indicates Cox
Creek could be a losing stream downgradient of
FPC-Tx. A study by the USGS Biological
Resources Division, Marine Ecotoxicology
Research Station, Texas A&M University - Corpus
Christi, Center for Coastal Studies (1999) focused
on the sediment quality of Lavaca Bay. The
purpose of the study was to determine the potential
ecotoxicological impacts of contaminants, using
sensitive sediment toxicity tests in conjunction with
chemical analyses. Twenty-four stations were
sampled, with test station number 18 situated close
to the Formosa outfall 001 in Lavaca Bay. This
station showed the highest total organic carbon
(TOC) with a 1.27 TOC percentage.
Ecological Risk
To evaluate the potential ecological risks at the
FPC-Tx facility, the Ecological Exclusion worksheet
that is part of the Region 6 Corrective Action
Strategy was completed and can be found in the
October 2009 RMP. Preliminary results indicate
that an ecological risk assessment is not warranted
at this time. As part of the performance monitoring
requirements, EPA proposes to have FPC monitor
surface water and sediment quality and will conduct
further assessments as needed, described in the
approved contingency plans (Section V.C.)
IV. CORRECTIVE ACTION OBJECTIVES and
REMEDIAL GOALS
The corrective action objectives (CAO's) are
developed by the EPA and are based on current
and reasonably anticipated land and groundwater
uses. It is EPA's policy to determine protective
media cleanup objectives for groundwater remedies
considering the use, value, and vulnerability of the
groundwater resource, and all potential pathways
that could result in human or ecological exposure to
contaminants. Typically, the groundwater use
designation is the starting point for determining the
appropriate reasonable expected uses and
exposures to evaluate risks and identify
groundwater cleanup levels. Shallow groundwater
resources in the area of FPC-Tx have been
classified by the TCEQ as Class II having a
beneficial use for agricultural and
municipal/industrial use. To determine the value of
an aquifer, EPA reviews the potential impact on the
underlying aquifer, the potential discharge to
surface water, and potential exposures to indoor
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air. There is some evidence that shallow
groundwater may discharge to surface water (no
impacts are known at this time); however, because
of the volatile nature of the site contaminants the
human and ecological exposure risk is low.
Potential for contaminated indoor air from the
affected groundwater at FPC-Tx is high due to the
volatile nature of the contaminants and the shallow
depth to groundwater. FPC-Tx will mitigate
potential indoor air exposures through the use of
engineered controls and institutional controls, as
applicable (see Section V. E).
Corrective Action Objective 1: The
groundwater cleanup objective is to contain
the plume, rather than returning the
groundwater to its maximum beneficial use
throughout the plume. The groundwater point
of compliance (POC) for FPC-Tx will be at the
Facility boundary (including the former
Brookings property), where concentrations of
chemicals of concern must be less than or
equal to the maximum contaminant limits
(MCLs) for drinking water. (In the event an MCL
is not established for a chemical of concern, a
risk-based action level will be developed.)
EPA is proposing to address the groundwater
areas of contamination as groundwater areas of
concern (AOCs) at FPC-Tx. For the purpose of
defining the groundwater plumes at FPC-Tx, there
are two AOCs identified - the former WWT area
and the VCM plant (Figures 3 and 4). In the
development of the Performance Monitoring Plan
for FPC-Tx (See Section V.A.), EPA will review and
approve locations of sentinel wells along the
boundary of each AOC. Preliminary boundaries for
AOC 1 and AOC 2 are shown in Figures 3 and 4.
The actual boundary of each AOC will be
determined when the sentinel wells for each zone
(which will serve as an alarm system to trigger
contingency plans) are installed. The sentinel well
system will serve as performance monitoring wells
to show that the plumes are contained. Protective
concentration levels (or "trigger levels") to be
maintained at each sentinel well for each
groundwater zone will be developed in the
Performance Monitoring Plan that will be reviewed
and approved by the EPA. Sentinel well
groundwater data will be presented in the
Performance Review Plan (the 3-year performance
review of the selected remedy). Beyond the AOC
boundary where trigger levels will measure the
containment objective, FPC-Tx will submit for
EPA's approval, locations for POC wells which may
be located at the facility boundary or other area
under control of FPC-Tx, or at the point where
groundwater discharges to surface water. The
POC wells must show that COC concentrations are
at MCLs.
Corrective Action Objective 2: To support the
final groundwater cleanup objective, FPC-Tx
must remove or treat source material in soils
and/or groundwater to the extent practicable.
Using TRRP, soils with concentrations of COCs
in excess of the soil saturation limit (Csat) must
be addressed, and groundwater with
concentrations of COCs in excess of 1%
solubility must be addressed through removal
or treatment.
Removal or treatment of source material in
subsurface soils that could leach into groundwater
will enhance the attainment of the corrective action
objectives for groundwater. FPC-Tx is investigating
a method by which source material in the
subsurface can be treated insitu to reduce the
contaminant release to groundwater from source
material. If the treatment process proves itself
through a pilot program, FPC-Tx will propose to set
up a "treatment cell" or "treatment barrier" to
address appropriate areas for each AOC.
Corrective Action Objective 3: For the
protection of on-site worker dermal contact or
ingestion of COCs in soils, FPC-Tx will control
or mitigate risks to appropriate TRRP industrial
screening levels for surface and subsurface
soils (see Table 1). Using TRRP guidance, risk
associated with soil concentrations in excess of
the GWSoil|ng will be mitigated.
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Figures* PreliminaryAOC 1 boundary
(Figures taken from 2008 CCTM Report)
Figure 4* Preliminary AOC 2 boundary
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Areas with exposed soils will be remediated/or
controlled as necessary to protect to the
appropriate TRRP industrial screening levels for
surface soils. Other areas under construction may
be capped to prevent exposures. Data from
investigation or construction sampling at SWMUs
will confirm that appropriate cleanup levels are
attained. Any active SWMUs associated with past
releases (SWMU 17 PVC had EDC soil
concentrations of 450 ppb which may be
contributing to groundwater contamination) will be
re-engineered with secondary containment or other
proper containment structures, as necessary to
mitigate potential releases. If subsurface soils are
being addressed through a removal action, then
confirmation sampling will confirm the attainment of
the appropriate TRRP cleanup level protective of
groundwater. Any residual contamination left in
place above cleanup levels must be managed to
prevent exposures. If saturated soils and
groundwater are being addressed through
treatment, then treatment must continue until
appropriate cleanup levels are attained. Data from
corrective measures at SWMUs will confirm that
appropriate cleanup levels are attained. The data
will be presented in 3-year remedy Performance
Reviews.
Corrective Action Objective 4: The corrective
action objective for surface water and sediment
is to assure protection of human and ecological
receptors by monitoring contaminant levels in
surface water features associated with AOCs.
Surface water/sediment sampling locations will be
proposed in the Performance Monitoring Plan.
Sampling results must confirm that contaminant
levels are protective of human health and the
environment. Because of the volatile nature of
chlorinated VOCs at FPC-Tx, elevated levels are
not expected in surface water. Surface water and
sediment data will be presented in the 3-year
Performance Review of the selected remedy. If
monitoring data reports contaminants at levels that
present an unacceptable human health or
ecological risk associated with exposure to COCs,
then FPC-Tx must implement the contingency
plans as described in Section V.C.
GREEN REMEDIATION / ECOLOGICAL
ENHANCEMENT GOALS
During all phases of corrective measures, FPC-Tx
will reduce energy requirements by using energy
efficient equipment and processes. Opportunities
for using renewable energy will be considered to
power remediation activities, such as solar-
powered pumps. Remediation approaches that
reduce resource use and impact on air, water
adjacent lands and public health will be considered
in all phases of the final remedy.
During all phases of corrective measures, FPC-Tx
will incorporate waste minimization and recycling of
materials to the maximum extent feasible.
Following final remediation of the former WWT
area, FPC-Tx will evaluate green remediation
technologies, such as the use of vegetative covers
to close out the structural units of the former WWT
plant.
To protect and enhance the ecological habitat for
the acquired Brookings Property, FPC-Tx will
evaluate ecological enhancements, such as
restoring native grasses on the pasturelands, and
restoring native habitat for birds, fish and other
aquatic species in Cox Creek. Based on the
property location, EPA is aware that studies may
need to be conducted to assure that an attractive
nuisance is not inadvertently created. The Wildlife
Habitat Council is available to review the ecological
conditions and settings of the site and can make
recommendations to protect and enhance
conditions for wildlife. [Please look into joining the
effort described in this WHC presentation:
http://www.wildlifehc.org/ewebeditpro/items/O5
7F4847.pdf!
V. PERFORMANCE-BASED MEASURES TO
ENSURE PROTECTIVENESS
All reports described below will be part of the
Corrective Measures Implementation (CMI) work
plan required under the 1991 EPA Order. EPA
replaced the requirements for a CMS with the RMP
(EPA letter dated April 24, 2009). This
performance-based decision document further
describes the intent to add the following reports to
Task XI CMI Program Plan: Performance
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Monitoring Plan, Performance Review Plan,
Contingency Plan, the Site Management Plan, and
the Treatability Study/SWMU Corrective Measures
Plan. (The EPA Order describes the submittal of a
Program Management Plan and a Community
Relations Plan). The additional plans are
necessary for the success of the final remedy,
considered by the EPA to be additional work as
described under Section IX. A. 6. of the EPA Order.
The schedule for implementation is outlined in
Appendix B of this document.
A. Performance Monitoring Plan
As part of the CM I Plan, FPC-Tx will be required to
submit, for agency approval a Performance
Monitoring Plan which outlines periodic sampling
of groundwater, soils, surface water and sediment
to measure the effectiveness of the remedy in
achieving the corrective action objectives. EPA is
proposing an optimization of the monitoring well
system already in place to ensure effective
compliance monitoring. This will include additional
monitoring well installations to effectively monitor
compliance at the POC. If groundwater extraction
continues to be part of the remedy to meet the
corrective action objectives, then additional
groundwater recovery wells may be needed, as
well. The optimization program will also make sure
that the monitoring wells are screened in proper
intervals for detection of contaminants of concern.
Recovery wells will need to be screened in
appropriate intervals to ensure maximum
contaminant extraction. The Performance
Monitoring Plan will also measure the effectiveness
of the remedy and will outline a clear definition of
the monitoring frequency, sampling locations and
data interpretation.
B. Performance Review Plan
As part of the CM I Plan, FPC-Tx will be required to
submit, for agency review and approval a
Performance Review Plan. This plan is a 3-year
assessment of progress towards achieving the
corrective action objectives, including a summary of
the effectiveness and efficiency of the preferred
alternative for the remedy. It will also include
recommendations for any needed changes in
performance monitoring and the adequacy and
effectiveness of land use controls. The
Performance Review Plan needs a clear decision
logic that defines 1) contingency plans to
implement when CAO's are not being met, 2) a
plan for phase-out of performance monitoring as
risk is reduced and 3) contingency plans to address
any potential changes in land use.
C. Contingency Plan
As part of the CMI Plan, FPC-Tx is required to
submit, for agency review and approval a
Contingency Plan which provides response
actions to address any new releases or poor
performance of the selected remedy. Failure to
achieve the CAO's will trigger a contingency plan to
correct the course of the remedy or to re-assess
performance measures. FPC-Tx will conduct a
Treatability Study (Section VI.F.) to study an
alternative technology to the interim measures
groundwater pump and treat system currently in
operation to remove and treat contaminated
groundwater. The Contingency plan will outline
other viable technologies, as well as an
optimization plan for the pump and treat system
that can be utilized to meet the CAO's.
D. Community Relations Plan
As part of the CMI Plan, FPC-Tx is required to
submit, for agency review and approval a
Community Relations Plan (CRP) which will
outline various ways that FPC-Tx will communicate
to the public and keep the public informed about
the overall effectiveness of the preferred remedy,
and of any needed changes or modifications to the
preferred remedy to meet the CAO's. An important
part of the CRP will be to keep the public informed
of the final treatment technology for soils and
groundwater.
E. Site Management Plan for Worker Protection
from Release Areas
FPC-Tx must implement institutional controls in the
form of a site-wide Site Management Plan as part
of the CMI plan to protect construction workers
from contaminants in surface and subsurface soils
and groundwater for all construction and
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excavation activities. The Site Management Plan
will describe internal procedures for obtaining
permits for excavation, proper protective clothing
and equipment for contractors or FPC-Tx
personnel, and all health and safety protocols that
will be followed for excavation activities. The Site
Management Plan will also include plans for
engineering controls and institutional controls for
mitigation of indoor air, including a description of
control rooms that are currently situated above any
known groundwater-contaminated areas (AOCs).
Mitigation for indoor air at these buildings will
include the following engineering controls: venting
along foundations or positive pressure inside the
buildings. EPA has developed a document to
present the "state of the science" regarding
management and treatment of vapor intrusion into
building structures. The document can be found at
http://www.clu-in.org/download/char/600r08115.pdf
EPA also proposes the use of any appropriate land
use controls (LUCs) to ensure that exposures to
residual contaminants in soil or groundwater are
not incurred. All land use controls will be described
in the Site Management Plan which specifies the
implementation and maintenance of land use
controls. The effectiveness and adequacy of land
use controls will be reviewed and documented as
part of the 3-year Performance Review Plan.
F. Treatability Study/SWMU Corrective
Measures at Former WWT plant
EPA requested that FPC-Tx conduct a Treatability
Study to determine if the source areas in the VCM
and former WWT plant can be treated using insitu
(in place) bioremediation or other insitu treatment
processes. Insitu bioremediation is a treatment of
contaminated soils and groundwater in place to
enhance the natural degradation of contaminants
by adding bacteria and nutrients to speed up the
breakdown process of hydrocarbons. Insitu
bioremediation is a relatively new technology that is
showing promising results at many RCRA sites. A
Treatability Study workplan will be incorporated as
part of the CM I workplans. If the Treatability Study
and sampling results from the implementation of a
pilot study (field test) support insitu treatment as a
viable approach to address contaminated soil and
groundwater, FPC-Tx may propose to implement
this technology on a full scale basis, which may
replace or supplement the pump and treat system
currently operating. If the pilot test proves that
current insitu treatment technologies are not
applicable for the FPC-Tx location, then FPC will be
required to optimize the pump and treat system in
place (as described in the Contingency Plan), or
FPC-Tx may propose another remedial option to
support the attainment of the CAO's. The final
corrective measures for the SWMUs will be
addressed concurrently with the proposal for soil
and groundwater treatment.
Following the approval of the RFI in January 2007,
the EPA set forth a schedule of activities leading up
to this decision document. First (Phase 1), FPC-Tx
completed the study of the former Brookings
property and second (Phase 2) FPC-Tx completed
the 2008 Current Conditions Technical
Memorandum which compiled the current
conceptual site model. FPC-Tx will implement a
Treatability Study in 2010 according to the EPA-
approved schedule (April 2004). Final corrective
measures for each SWMU will follow the approved
schedule in the Final 2009 RMP.
FORMOSA PLASTICS
POINT COM FORT,
TEXAS
RCRA CORRECTIVE
ACTION
PUBLIC MEETING
Thursday,
October 15, 2009
at 7:00 PM
Calhoun High School
210Sandcrab Blvd
Port Lavaca, Tx
FOR MORE
INFORMATION:
If you have questions,
please contact:
Ms. Nancy Fagan,
Project Manager
U.S. EPA (6PD-O)
1445 Ross Avenue
Dallas, Texas 75202-
2733
(214) 665-8385
Fagan.nancy@epa.gov
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GLOSSARY OF TERMS
Administrative Record -A collection of documents that includes sampling analyses, reports, communications and other
supporting information that form the basis for the remedy selection.
Aerobic bioremediation - a process of adding nutrients to groundwater in a rich oxygen environment to speed up the
natural process in which bacteria breaks down chemicals.
Anaerobic bioremediation - a process of adding nutrients to groundwater in a low oxygen environment to speed up the
natural process in which bacteria breaks down chemicals.
Aquifer - A layer of permeable rock, sand, or gravel below the ground's surface that can supply usable quantities of
ground water to wells and springs. An aquifer can be a source of drinking water.
Area of contamination (AOC) - An EPA policy that allows certain discrete areas of generally dispersed contamination to
be considered a RCRA unit. Consolidation and insitu treatment of hazardous waste within the AOC does not create a
new point of generation for RCRA purposes. Under the AOC policy, the site owner may consolidate and treat
contaminated soil within the AOC.
Carbon tetrachloride - a compound consisting of one carbon and four chlorine atoms commonly used in solvents.
Chemicals of concern (COCs) - After risk screening, the contaminants that have the potential to pose a significant risk
are labeled COCs.
Cis-1,2 DCE (cis-1,2-dichloroethene) - a chemical that is one of the natural breakdown products of trichloroethane (TCE).
Conceptual Site Model (CSM) - Part of the Data Quality Objective process that presents a three-dimensional picture of
site conditions at a discrete point in time that conveys what is known about the facility, releases, release mechanisms,
contaminant fate and transport, exposure pathways, potential receptors, and risk.
Corrective Action Objectives (CAOs) - Site-specific objectives that support the performance standards of source
control through removal, treatment or containment, statutory/regulatory requirements or final risk goals for the protection
of human health and the environment.
Corrective Measures Study (CMS) - A traditional report submitted after the completion of site investigation which
serves as an evaluation of the alternatives for cleanup of sites contaminated with hazardous waste.
1,1-dichloroethane (1,1-DCA) is a chlorinated hydrocarbon. It is a colorless oily liquid with a chloroform-like odor. It is
not easily soluble in water, but miscible with most organic solvents.
1,2-dichloroethane (1,2-DCA) or Ethylene Dichloride (EDC) - The chemical compound 1,2-dichloroethane, commonly
known by its old name of ethylene dichloride (EDC), is a chlorinated hydrocarbon, mainly used to produce vinyl chloride
monomer (VCM), the major precursor for PVC production. It is a colorless liquid with a chloroform-like odor. 1,2-
Dichloroethane is also used generally as an intermediate for other organic chemical compounds, and as a solvent.
Exposure pathway - The course a chemical takes form a source to an exposed receptor. Each exposure pathway
includes a source or release from a source, an exposure point, and an exposure route.
Facies changes - The term fades refers to all of the characteristics of a particular rock unit. For example, you might refer
to a "tan, cross-bedded oolitic limestone fades". The characteristics of the rock unit come from the depositional
environment. Every depositional environment puts its own distinctive imprint on the sediment, making a particular fades.
Thus, a fades is a distinct kind of rock for that area or environment.
Fluvial depositional environments - Beach sands and river channel deposits are examples of fluvial transport and
deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans.
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Glossary
Ground Water - Water located beneath the ground surface in soil pore spaces and in the fractures of lithologic
formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water.
Groundwater-saturated units or zones - A subsurface zone in which water fills the interstices and is under pressure
greater than atmospheric pressure. Also known as phreaticzone; saturated zone, usually unconsolidated silty sands in
the subsurface that have large enough pore spaces to contain water. The shallow zones are usually above a confining
layer and recharged through an upgradient exposure to precipitation.
Hydrogeology - the study of the distribution and movement of groundwater in the soil and rocks of the Earth's crust,
(commonly in aquifers).
Inorganic - Chemical substances of mineral origin, not of basically carbon structure.
In situ (in place) bioremediation -A process of adding nutrients and/or bacteria directly to groundwater and soils using
below-grade (in place) technology to speed up the natural chemical breakdown process.
Interdistributary deposits -sedimentary deposits of sand, silt and clays associated with distributary channels in a fluvial
depositional environment.
Laboratory Reporting Limits - there are two distinct classes of reporting limits: detection limits and quantitation
limits. Detection limits refer to a minimum concentration of an analyte that can be measured above the instrument
background noise. Thus, when detection limits are used as reporting limits, the laboratory is saying that the analyte is not
present at or above the value given. It may be present at a lower concentration, but cannot be "seen" by the instrument.
Quantitation limits refer to a minimum concentration of an analyte that can be measured within specified limits of precision
and accuracy. They are generally 5-10 times the detection limit. Thus, when quantitation limits are used as reporting
limits, the laboratory is saying that the analyte is not present in a sufficient amount to be reliably quantified
Low-flow sampling - An EPA-approved method used to extract groundwater samples from wells using minimal
drawdown techniques with the objective to obtain samples that are representative of groundwater conditions. Utilizing
this technique minimizes purge water during sampling. [April 1996 EPA Groundwater Issue EPA/540/S-95/504]
Maximum Contaminant Limits (MCL) - Maximum permissible concentration of a contaminant in water which is delivered
to any user of a public water system.
Monitoring Wells - Special wells drilled at specific locations on or off a site where ground water can be sampled at
selected depths and studied to determine such things as the direction in which ground water flows and the types and
amounts of contaminants present.
Natural attenuation or Monitored natural attenuation (MNA) - a process whereby only monitoring of the natural
breakdown process takes place. MNA is an accepted remedy only in circumstances where sources of contamination
have been removed to the extent practicable, and the environment is conducive to natural chemical breakdown.
No Further Action (NFA) - no further remedial actions are undertaken to address the existing ground water and soil
contamination. NFA determinations can be made when the site no longer poses a risk to human health or the
environment.
Nonaqueous phase liquid (NAPL) - The term NAPL refers to the undissolved liquid phase of a chemical, such as
trichloroethylene (TCE), and not to the aqueous phase dissolved in water. Virtually all NAPLs are organic compounds
that are immiscible (resistant to mixing) with water. The distinct interface resulting from the water-NAPL contact does
allow some NAPL to dissolve, with the degree of aqueous solubility varying dramatically among NAPL compounds. As
NAPL moves through the soil and aquifer, a portion becomes trapped and a portion may continue to migrate. The "free-
phase NAPL" is the migrating portion, which can flow into a well. "Residual NAPL" is that portion trapped in the soil or
aquifer and no longer migrates as a separate phase. Both residual and free-phase NAPLs are sources of vapors and
dissolved contaminants.
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Glossary
Non-potable - water that is unsafe or unpalatable to drink because it contains pollutants, chemicals or minerals.
Organics - Compounds which contain carbon. For example, trichloroethylene is an organic compound.
Parts Per Million (ppm)/Parts Per Billion (ppb) - Units of measure used to express concentrations of contaminants. 1
ppm is equal to 1,000 ppb and 1 ppb is equal to 0.001 ppm. Also, 1 ppm is equal to 1 mg/kg or 1 mg/l; 1 ppb is equal to 1
ug/kg or 1 ug/l. As an example, 1 ounce of trichloroethylene in 1 million ounces of water is 1 ppm.
Perchloroethylene (PCE) - stable colorless liquid,nonflammable and nonexplosive with low toxicity; used as an industrial
solvent and in metal cleaning. Another name for this chemical is tetrachloroethylene, also sometimes called "perc".
Point of Compliance (POC) - The designated point of compliance (POC) is where the cleanup standard must be met. In
groundwater corrective action, the POC is often described as the point at which the facility must meet the MCLs.
Protective Concentration Levels (PCLs) - cleanup standards for the Texas Risk Reduction Program (TRRP).
Potentiometric surface map - a contour map of the water levels that represent the top of a groundwater-bearing zone.
Resource Conservation and Recovery Act (RCRA) - This law authorizes the federal government to respond directly to
releases of hazardous waste which may be a threat, or potential threat, to public health and the environment. EPA is
responsible for implementing Section 3008(h) of RCRA in the State of New Mexico.
RCRA Facility Investigation (RFI) -An investigation to determine the nature and extent of contamination at a facility.
Risk Management Plan (RMP) - submittal required by the EPA which can replace the requirement for a CMS (see
Region 6 Corrective Action Strategy (CAS) November 2008.
Sentinel wells - a system of nested groundwater monitoring wells screened in each saturated zone located a distance
away from the plume edge. The wells serve as an early warning that contaminants may not be at MCLs at the point of
compliance. Detections above protective levels will trigger contingency plans.
Site constituents - chemicals associated with processes at the site (facility).
Solid waste management units (SWMUs) - Any discernable unit at which solid wastes have been placed at any time,
irrespective of whether the unit was intended for the management of solid or hazardous waste. Such units include any
area at a facility.
Source area / source material - Source material is defined as material that includes or contains hazardous wastes or
hazardous constituents that act as a reservoir for migration of contamination to soil, to groundwater, to surface water, to
air, or act as a source for direct exposure. Contaminated groundwater plumes are generally not considered a source
material, although non-aqueous phase liquids (NAPL) in the groundwater generally would be viewed as source material.
Split sampling - a term used to describe the collection of samples of any media (groundwater, sediment, soils) where
the facility collects a sample, and an agency (federal or state) collects a duplicate sample for identical analyses.
Texas Risk Reduction Program (TRRP) The Texas Risk Reduction Program was promulgated in 1998 as the Texas
Commission on Environmental Quality (TCEQ) Corrective Action program. The TCEQ if fully authorized by the US EPA
to regulate the RCRA Subtitle C (hazardous waste) program, http://www.tceq.state.tx.us/remediation/trrp/trrp.html
Trans-1,2-dichloroethene - Incompatible with oxidizing agents, bases. Stable, but may decompose on exposure to air,
moisture or light. Highly flammable. Harmful if swallowed or inhaled, and in contact with the skin.
Trichlorethene (TCE) - a clear, nonflammable liquid with a sweet smell. A chlorinated hydrocarbon commonly used as
an industrial solvent (a degreaser for metal parts). Most TCE is produced from ethylene. It is unstable in the presence of
metal over a prolonged exposure.
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Glossary
Volatile hydrocarbons / volatile organic compounds (VOCs) - organic chemical compounds that have high enough
vapor pressures under normal conditions to significantly vaporize and enter the atmosphere. VOCs may be natural or
synthetic. Like organic chemicals in general, there are millions of different compounds which may be classified as VOCs.
The compounds the nose detects as smells are generally VOCs. Modern industrial chemicals such as fuels, solvents,
coatings, feedstocks, and refrigerants are usually VOCs.
Vinyl chloride- is the organochloride with the formula CH2:CHCI. It is also called vinyl chloride monomer, or VCM. This
colourless compound is an important industrial chemical chiefly used to produce the polymer polyvinyl chloride (PVC). At
ambient pressure and temperature, vinyl chloride is a gas with a sickly sweet odor. It is highly toxic, flammable and
carcinogenic. Vinyl chloride is produced on a substantial scale - approximately 31.1 million tons were produced in 2000.
Two methods are employed, the hydrochlorination of acetylene and the dehydrochlorination of ethylene dichloride (1,2-
dichloroethane). Vinyl chloride is a chemical intermediate, not a final product. Due to the hazardous nature of vinyl
chloride to human health there are no end products that use vinyl chloride in its monomer form. Polyvinyl chloride is very
stable, storable, and less acutely hazardous than the monomer. Vinyl chloride liquid is fed to polymerization reactors
where it is converted from a monomer to a polymer PVC. The final product of the polymerization process is PVC in either
a flake or pellet form. Literally, tens of billions of pounds of PVC are sold on the global market each year. From its flake or
pellet form PVC is sold to companies that heat and mold the PVC into end products such as PVC pipe and bottles. Until
1974, vinyl chloride was used in aerosol spray propellants. Prior to the removal of vinyl chloride from hair spray the
accumulation of vinyl chloride vapor in hair salons may have exceeded the NOAEL (No Observable Adverse Effect Level)
exposure guidelines. For more information on vinyl chloride please see http://en.wikipedia.org/wikiA/inyl chloride.
Water Table - The upper surface of ground water in an aquifer. The water table marks the boundary between the
unsaturated soil and saturated soils of the aquifer.
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FORMOSA PLASTICS CORPORATION - TX - PUBLIC COMMENT PERIOD
The 45-day public comment period for the FPC-Tx Facility will begin on October 15, 2009, and end on
November 30, 2009. Your written comments must be postmarked by November 30, 2009. Please
write your comments below, then fold, tape, stamp, and mail this form. EPA will address all
comments received during the public comment period in the Final Decision and Response to
Comments. If you would like to receive a copy of the Response to Comments, please include your
full name and address on the return address form.
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FORMOSA PLASTICS POINT COMFORT, TEXAS
RCRA CORRECTIVE ACTION
PUBLIC COMMENT PERIOD
The public comment period for the FPC-Tx begins October 15, 2009. Your comments
must be post marked by November 30, 2009, or you may choose to email your
comments to Fagan.nancy@epa.gov.
Name
Address.
City
State Zip_
U.S. EPA Region 6
Attn: Nancy Pagan Mail Code: 6PD-O
1445 Ross Avenue
Dallas, TX 75202-2733
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Appendix A: SWMU Status
TABLE 1
SWMU Status
NO FURTHER ACTION (NFA)
There are no further investigation or corrective action requirements associated with
these SWMUs.
DRAFT
8 pH Adjustment Pit
9 Primary Clarifier
10 Sludge Thickener
11 Final Clarifier
12 Deep Well
13 Inactive Final Clarifier
14 Sludge Digester
15 Parshall Flume
16 Cooling Tower Slowdown
18 Drum Storage Area
20 Acid tank
26 EDC Storage Tank (VT-102)
27 Laboratory Wastes Area
28 Decoking Pit
29 Deionization Regeneration Waste Pit
30 Boiler Slowdown Sump
31 Used Oil Storage Area
32 Empty Container Storage Area
33 Chemical Sewer System
34 Storm Water Sewer System
COG Concentration > GWSoili.Q PCL
Concentrations of COCs in soil in excess of the GWSoillng PCL may indicate that
COCs may leach from soil to underlying groundwater.
WWTPAREA (AOC 1)
2 Equalization Basin
5 Andco Basin
6 Aeration Basin
7 Sludge Drying Beds
VCM Area (AOC 2)
17 PVC Settling Pits
19 Incinerator
24 EDC Storage Tank (VT-763A)
25 EDC Storage Tank (VT-763B)
35 Secondary Containment EDC Tank (VT-732)
COC Concentration >
, PCL
Concentrations of COCs in soil in excess of the
COCs represent direct contact risks.
'Soilcomb PCL may indicate that
WWTP AREA (AOC 1)
3 Surge Basin
4 Emergency Basin
VCM AREA (AOC 2)
1 Storm Water Basin
21 Holding Pit
22 Inactive Chemical Sewer Pump
23 VCM Wastewater Pit
TRRP PCLs (mg/kg)
Benzene
Chlorobenzene
Chloroform
Dichloroethane, 1,1-
Dichloroethane, 1,2-
Dichloroethylene, 1,1-
Dichloroe£hy]ene, cis-1,2-
Dichloroethylene, trans- 1,2
Tetrachloroethylene
rrichlorocthane, 1,1,2-
Trichloroethylene
Vinyl chloride
Tatc«n
*o"ow»
1.8E-K>2
l.OE+03
2.6E+01
8,2E+fl3
2.2E+OI
6.4E+03
6.4E+03
1.2E+03
3.6E+02
3.5E+01
3.1E+02
1.5E+01
GWSoil,M
2.6E-02
1.1E+00
3.0E+00
5.5E+01
1 .4E-02
5.0E-02
2.5E-OI
4.9E-01
5.0E-02
2.0E-02
3.4E-02
2.2E-02
Page 1 of 1
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Appendix B: Proposed Schedule of Remedy Implementation
2010 - Treatability Study/AOC Delineation
2011 - Design Plan for Final Remedy
2012 - Remedy construction
2015 - First 3-year Performance Review
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