REMEDIATION SYSTEM EVALUATION
FCX-STATESVILLE SlJPERFUND SITE
STATESVILLE, NORTH CAROLINA
Report of the Remediation System Evaluation,
Site Visit Conducted at the FCX-Statesville Site
20-22 September, 2000
Final Report Submitted to Region 4
March 2002
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NOTICE
Work described herein was performed by GeoTrans, Inc. (GeoTrans) and the United States Army Corps
of Engineers (USAGE) for the U.S. Environmental Protection Agency (U.S. EPA). Work conducted by
GeoTrans, including preparation of this report, was performed under Dynamac Contract No. 68-C-99-
256, Subcontract No. 91517. Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
This document (EPA 542-R-02-008e) may be downloaded from EPA's Technology Innovation Office
website at www.epa.gov/tio or www.cluin.org/rse.
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EXECUTIVE SUMMARY
The PCX property was an agriculture distribution center that formulated, repackaged, and
warehoused pesticides and fertilizers. The former Burlington Industries property to the north and
upgradient of the PCX property was a textile facility that used chlorinated solvents. These two
properties comprise the FCX-Statesville Superfund Site. Pesticides and chlorinated solvents, mainly
PCE, are present in soil and groundwater at the site. The groundwater VOC plume extends to the
north, west and south from the site while the pesticide plume is comingled only in the southern
extension of the VOC plume. The site is underlain by 15 to 65 feet of saprolite and residual soil
hydraulically interconnected with underlying fractured bedrock generally consisting of gneisses and
schists.
USEPA has divided the site into three operable units:
OU1: The groundwater contamination beneath the PCX property and to the south of the
PCX property.
OU2: The soil contamination (mainly pesticides, polycyclic aromatic hydrocarbons
(PAHs), pentachlorophenol, and dioxin) at the PCX property.
OU3: All other contamination which was not characterized during the initial RI/FS (mainly
soil, groundwater, and surface water/sediment contaminated with volatile organic
compounds centered at the former textile facility).
This RSE only pertains to the ongoing groundwater remediation of OU1. OU1 and OU2 are being
remediated by USEPA, while OU3 is being remediated separately by PRPs.
The RSE suggests several potential modifications to address effectiveness/ protectiveness issues,
including:
• Updating the target containment zone considering the interconnection of the saprolite
with bedrock and reconsidering the OU1 system goals to possibly concentrate
pumping on the pesticide plume.
• Cleaning up the site including debris removal, landscaping, and sediment control
measures.
Improving or replacing the existing treatment system enclosure and header piping.
The enclosure has inadequate space and no secondary containment or leak alarm
system and the air and groundwater header piping have had leaks.
The RSE also suggest several potential modifications to reduce long-term costs including:
Discharging to surface water by NPDES rather than discharging to the POTW
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(potential net savings of more than $1 M over 30-years, non-discounted).
• Removing the sand filter and appurtenant backwashing equipment (potential net
savings of more than $0.2 M over 30 years).
• Eliminating or reducing monitoring frequency for non-essential compounds
(potential net savings of more than $0.4 M over 30 years, non-discounted).
• Suspending recovery pumping entirely if monitored natural attenuation is suitable for
the pesticide plume as it is (OU3 ROD) for the VOC plume (potential net savings of
more than $3 M over 30 years, non-discounted).
Estimated capital and annual costs (and savings) associated with recommendations are summarized
in a table at the end of the report.
in
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PREFACE
This report was prepared within the context of a demonstration project conducted by the United
States Environmental Protection Agency's (USEPA) Technology Innovation Office (TIO). The
objective of the overall project is to demonstrate the application of optimization techniques to Pump-
and-Treat (P&T) systems at Superfund sites that are "Fund-lead" (i.e., financed by USEPA). The
demonstration project was conducted in USEPA Regions 4 and 5.
The demonstration project has been carried out as a cooperative effort by the following
organizations:
Organization
USEPA Technology Innovation Office
(USEPA TIO)
GeoTrans, Inc.
(Contractor to USEPA TIO)
Army Corp of Engineers:
Hazardous, Toxic, and Radioactive
Waste Center of Expertise
(USACE HTRW CX)
Key Contact
Kathy Yager
Doug Sutton
Dave Becker
Contact Information
UTechnology Drive (ECA/OEME)
North Chelmsford, MA 01863
phone: 617-918-8362
fax: 617-918-8427
yager.kathleen@epa. gov
GeoTrans, Inc.
2 Paragon Way
Freehold, NJ 07728
(732) 409-0344
Fax: (732) 409-3020
dsutton@geotransinc.com
12565 W. Center Road
Omaha, NE 68144-3869
(402) 697-2655
Fax: (402) 691-2673
dave.j .becker@nwd02.usace.army
mil
The project team is grateful for the help provided by an EPA Project Liaison in each Region.
Region 1
Region 2
Region 3
Region 4
Region 5
Darryl Luce and Larry Brill
Diana Curt
Kathy Davies
Kay Wischkaemper
Dion Novak
Region 6
Region 7
Region 8
Region 9
Region 10
Vincent Malott
Mary Peterson
Armando Saenz and
Herb Levine
Bernie Zavala
Richard Muza
They were vital in selecting the Fund-lead P&T systems to be evaluated and facilitating
communication between the project team and the Remedial Project Managers (RPMs).
IV
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TABLE OF CONTENTS
EXECUTIVE SUMMARY ii
PREFACE iv
TABLE OF CONTENTS v
1.0 INTRODUCTION 1
1.1 PURPOSE 1
1.2 TEAM COMPOSITION 1
1.3 DOCUMENTS REVIEWED 2
1.4 PERSONS CONTACTED 2
1.5 SITE LOCATION, HISTORY, AND CHARACTERISTICS 3
1.5.1 LOCATION 3
1.5.2 POTENTIAL SOURCES 3
1.5.3 HYDROGEOLOGIC SETTING 4
1.5.4 DESCRIPTION OF GROUNDWATER PLUME 4
2.0 SYSTEM DESCRIPTION 6
2.1 SYSTEM OVERVIEW 6
2.2 EXTRACTION SYSTEM 6
2.3 TREATMENT SYSTEM 6
3.0 SYSTEM OBJECTIVES, PERFORMANCE AND CLOSURE CRITERIA 8
3.1 CURRENT SYSTEM OBJECTIVES AND CLOSURE CRITERIA 8
3.2 TREATMENT PLANT OPERATION GOALS 8
4.0 FINDINGS AND OBSERVATIONS FROM THE RSE SITE VISIT 9
4.1 FINDINGS 9
4.2 SUBSURFACE PERFORMANCE AND RESPONSE 9
4.2.1 WATERLEVELS 9
4.2.2 CONTAMINANT LEVELS 9
4.3 TREATMENT SYSTEM DOWN-TIME 9
4.4 COMPONENTS OR PROCESSES THAT ACCOUNT FOR MAJORITY OF COSTS 9
4.4.1 UTILITIES 10
4.4.2 NON-UTILITY CONSUMABLES AND DISPOSAL 10
4.4.3 LABOR 10
4.4.4 SAMPLING AND REPORTING 10
4.4.5 SUMMARY OF TOTAL COSTS 11
4.5 RECURRING PROBLEMS ORISSUES 11
4.5.1 SANDFILTERS 11
4.5.2 SAND IN INFLUENT TANK 11
4.5.3 PlPINGLEAKS 11
4.5.4 OPEN MONITORING WELLS 12
4.6 REGULATORY COMPLIANCE 12
4.7 TREATMENT PROCESS EXCURSIONS AND UPSETS, ACCIDENTAL CONTAMINANT/REAGENT
RELEASES 12
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4.8 SAFETYRECORD 12
5.0 EFFECTIVENESS OF THE SYSTEM TO 13
5.1 GROUNDWATER 13
5.2 SURFACE WATER 13
5.3 SOILS 13
5.4 OTHER 13
6.0 RECOMMENDATIONS 14
6.1 RECOMMENDED STUDIES TO ENSURE PROTECTIVENESS 14
6.1.1 UPDATE TARGET CONTAINMENT ZONE 14
6.1.2 SITE CLEANUP 14
6.1.3 IMPROVED TREATMENT SYSTEM ENCLOSURE AND HEADER PIPING 15
6.2 RECOMMENDED CHANGES TO REDUCE COSTS 15
6.2.1 DISCHARGE TO SURFACE WATER (NPDES) 15
6.2.2 REMOVE THE SAND FILTER 15
6.2.3 ELIMINATE SVOC AND METALS IN QUARTERLY WELL SAMPLING ANALYSIS 15
6.2.4 CONCENTRATE SYSTEM ON PESTICIDES 16
6.2.5 SUSPENSION OF PUMP AND TREAT 16
7.0 SUMMARY 17
List of Tables
Table 1. Total VOCs and total pesticides at select wells.
Table 2. Groundwater remediation goals and POTW discharge limits.
List of Figures
Figure 1. PCX OU1 site map.
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1.0 INTRODUCTION
1.1 PURPOSE
The US Environmental Protection Agency's (USEPA) Technology Innovation Office (TIO) and the
US Army Corps of Engineers (USAGE) Hazardous, Toxic, and Radioactive Waste Center of
Expertise (HTRW CX) are cooperating in the demonstration of the USAGE Remediation System
Evaluation (RSE) process at Superfund sites. The demonstration of the RSE's is part of a larger
effort by TIO to provide USEPA Regions with various means for optimization, including screening
tools for identifying sites likely to benefit from optimization and computer modeling optimization
tools for pump and treat systems, such as the MODMAN code.
The FCX-Statesville site was chosen based on initial screening of pump and treat systems managed
by USEPA Region 4 and represented a site with relatively high operation cost and a long projected
operating life. Two sites in Regions 4 and 5 are being evaluated with RSE's in this demonstration
project. A report on the overall results from these demonstration sites will also be prepared and will
identify lessons learned, typical costs savings, and a process for screening sites in the USEPA
Regions for potential optimization savings.
The RSE process is meant to identify cost savings through changes in operation and technology, to
evaluate performance and protectiveness (as required under the NCP, i.e., and "five-year" review),
assure clear and realistic remediation goals and exit strategy, and verify adequate maintenance of
Government owned equipment. This report provides a brief background on the site and current
operations, a summary of the observations made during a site visit, and recommendations for changes
and additional studies. The cost impacts of the recommendations are also discussed.
1.2 TEAM COMPOSITION
The team conducting the RSE included:
Kathy Yager, HQ EPA TIO
Peter Rich, Engineer, GeoTrans, Inc. (EPA TIO's contractor)
Bob Briggs, Engineer, GeoTrans, Inc. (EPA TIO's contractor)
Lindsey Lien, Engineer, USAGE HTRW CX
Dave Becker, Geologist, USAGE HTRW CX
Kay Wischkaemper, Hydrogeologist, EPA Region 4
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1.3
DOCUMENTS REVIEWED
The following documents were reviewed as part of the RSE evaluation:
Author
EPA
Roy F. Weston, Inc. (Weston)
EPA
EPA
Westinghouse Remediation
Services, Inc. (WRS)
Weston
WRS
WRS
WRS
WRS
Brown & Caldwell
Brown & Caldwell
Weston
Date
9/27/93
6/94
11/22/94
9/30/96
12/22/97
1/99
2/16/99
2/99
5/5/99
8/26/99
7/12/00
6/14/00
7/00
Title/Description
ROD OU1
Risk Assessment Report, OU2
ROD OU2
ROD OU3
Remedial Action Work Plan, OU1
Remedial Action Report, OU1
Initial Startup and First Quarter
Sampling Event Report
2nd Quarter Sampling Event Report
3rd Quarter Sampling Event Report
4th Quarter Sampling Event Report
Remedial Action Work Plan, OU3
Results of 12/99 Sampling for
Monitored Natural Attenuation at
OU3
Long Term Response Action - First
Quarter Sampling Event Report
1.4
PERSONS CONTACTED
The following individuals were present during the site visit:
McKenzie Mallary, EPA RPM, Region IV
Nile Testerman, North Carolina Department of Environment and Natural Resources
(NCDENR)
Joseph Ferentz, Roy F. Weston, Inc. Norcross, GA
Matt Brennan, Applied Earth Sciences, Inc., Charlotte, NC
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1.5 SITE LOCATION, HISTORY, AND CHARACTERISTICS
This RSE pertains to OU1 at the FCX-Statesville Superfund Site (also referred to as "the site"). The
FCX-Statesville Superfund site includes the former PCX property and an adjacent property. This
adjacent property was at the time of the OU3 ROD owned and operated by Burlington Industries.
The FCX-Statesville property was an agricultural distribution center that is no longer active. The
adjacent property was a textile facility that is also no longer active. USEPA has divided the site into
three operable units (see Figure 1):
OU1: The groundwater contamination beneath the PCX property and to the south of the
PCX property.
OU2: The soil contamination (mainly pesticides, polycyclic aromatic hydrocarbons
(PAHs), pentachlorophenol, and dioxin) at the PCX property.
OU3: All other contamination which was not characterized during the initial RI/FS (mainly
soil, groundwater, and surface water/sediment contaminated with volatile organic
compounds centered at the former textile facility).
This RSE only pertains to the ongoing groundwater remediation of OU1. OU1 and OU2 are being
remediated by USEPA, while OU3 is being remediated separately by PRPs.
1.5.1 LOCATION
The site is located in a mixed residential and commercial area in Statesville, North Carolina. The site
is located in Iredell County, and is approximately 60 miles north of Charlotte.
The site generally slopes to the south. The site is fenced except for the paved loading dock area
along West Front Street where four (4) of the ten (10) recovery wells are located (see Figure 1).
Approximately one half of the site is covered by the former PCX warehouse. OU2 soil excavation
and treatment operations are currently taking place within the warehouse building and on a concrete
pad in the northeast corner of the site. The 10 OU1 recovery wells are all onsite running in a line
from the southwest to northeast corners of the site on approximately 50 feet centers (see Figure 1).
The treatment system is housed in a prefabricated metal structure in the southeast corner of the site.
The former Burlington Industries facility is located across railroad tracks immediately north of the
PCX property.
1.5.2 POTENTIAL SOURCES
Beginning around 1940, Farmer Cooperative Exchange (PCX) began operations at the site as an
agricultural distribution center. Activities included the formulation, repackaging, warehousing, and
distribution of farm chemicals. These chemicals consisted primarily of pesticides and fertilizers.
Repackaging of liquid pesticides was discontinued in 1966 and pesticide dust repackaging was
discontinued in 1969.
Testimony from previous employees indicates that 5,000 to 10,000 pounds of DDT, DDE, and
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possibly liquid chlordane were buried in two trenches which were subsequently covered by a
concrete warehouse floor. Pesticide contamination in the soil as well as pesticide and volatile
organic compound (VOC) contamination of the groundwater has been documented at the PCX site.
Pesticides in soil are being excavated and treated by thermal desorption prior to backfilling the
remediated material (OU2). The VOC contamination in the groundwater appears to be emanating
from the former Burlington Industries facility.
1.5.3 HYDROGEOLOGIC SETTING
The PCX site lies within the Blue Ridge - Inner Piedmont Geologic Belt. This Belt generally
consists of metamorphic rocks including gneisses and schists, as well as gradations of these two
types. Most of these rocks near the surface have weathered into a layer of "overburden" overlying
the fractured but relatively unweathered bedrock. The overburden ranges in thickness from 15 to 65
feet at the site, and consists of saprolite and residual soils interspersed with unweathered
gneiss/schist, and to a lesser degree, alluvium. Granitic intrusions are also common in the area of the
site. Soils in the general area belong to the Lloyd Association. These soils are characterized as deep,
well-drained soils with a subsoil of dark red clay.
Groundwater at the site occurs in an unconfined to semiconfmed aquifer consisting of the overburden
hydraulically interconnected with the underlying fractured bedrock. The saturated overburden serves
as a groundwater reservoir which supplies water to the fractures, faults, and other secondary
permeability features in the bedrock. Approximate depth to groundwater in the saturated overburden
generally ranges from 27 to 35 feet below land surface (bis). During wetter periods of the year,
groundwater may intersect the ground surface south of the site and become overland or surface water
flow.
The regional geology and hydrogeology was verified during installation of recovery well 1 (RW-1).
The depth to bedrock was determined to be 65 feet. The lithology consisted of approximately 20 feet
of clay, 40 feet of saprolite and saprolitic gneiss, and 5 feet of highly altered granite.
The direction of shallow groundwater flow is to the southeast with a gradient (i) of approximately
0.016.
1.5.4 DESCRIPTION OF GROUNDWATER PLUME
The remediation system that is the focus of this RSE includes recovery wells screened in saprolite to
a depth of 56.5 to 65 feet. Contaminants present in groundwater in the saprolite and bedrock beneath
it include:
Pesticides: Alpha-BHC, Beta-BHC, Delta-BHC, Gamma-BHC (lindane), Dieldrin, Engrin
Ketone, Chlordane, and Endrine.
VOCs: Tetrachloroethylene, Trichloroethylene, 1,1,1-trichloroethane, 1,1-dichloroethane,
chloroform, 1,1-dichloroethylene, and cis-l,2-dichloroethylene.
A groundwater divide under the former Burlington Industries site and the pumping of an industrial
well to the west (Carnation) has resulted in several dissolved contaminant plumes extending from the
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site. PCE and its breakdown VOC products, defined by a 1 • g/L contour, extend approximately 800
feet south, north, and west of the source areas on the former Burlington property. The separate
pesticide plume extends south from the PCX property with the VOC plume (see Table 1).
Pesticides strongly sorb onto soils, and thus migrate very slowly with respect to groundwater
velocity, while chlorinated VOCs are much more mobile. However, pesticides have been detected in
a bedrock well 500 feet south of the PCX property.
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2.0 SYSTEM DESCRIPTION
2.1 SYSTEM OVERVIEW
The remediation system consists of 10 extraction wells in areas of dissolved contamination located
on-site. The treatment system consists of a 300 gallon influent equalization tank, a 1200 gallon
baffled tank (clarifier), two sand filters with a backwash trickle tank, and two GAC units. Potassium
permanganate and polymer were formerly added into the groundwater prior to the baffled tank, but
that chemical addition has been suspended. Water is discharged from the treatment plant to the
sanitary sewer.
2.2 EXTRACTION SYSTEM
The ten (10) OU1 extraction wells have pneumatic total fluids submersible pumps that maintain a
drawdown at the pump level. The wells are operated with drawdowns of 20 to 30 feet in the 56.5 to
65 feet deep 4-inch diameter PVC saprolite recovery wells. Design phase capture zone calculations
indicated that this drawdown with 50 gpm pumping would prevent further migration offsite. The
system began pumping in May 1998 and was operated for 12 !/> months by WRS prior to shutdown
due to contracting issues. Pumping was restarted in April 2000 by Weston, but suspended in July
2000 due to exceedances of discharge levels for chloroform. The extraction rate was intended to be
30 to 50 gpm based on a 72 hour pump test conducted in 1997. Approximately 12 gpm of pumping
was averaged during the 12 !/> months of system operation by WRS.
2.3 TREATMENT SYSTEM
All equipment was provided by Envirosys International, Inc.
The OU1 treatment system, designed for 50 gpm, consists of the following:
• A 15 HP air compressor and 1-inch PVC air line to supply air to the pneumatic
pump;
• 2-inch PVC underground header pipe from the extraction wells;
• 300 gallon influent holding tank;
• Polymer and potassium permanganate injection systems with appurtenant static
mixers (inactive);
A baffled 1200 gallon tank;
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• Two sand filters with a backwash system including a 350 gallon backwash influent
tank and 250 gallon backwash effluent trickling filter sump; and,
• Two 2000-pound liquid phase granular activated carbon (GAC) units.
The flow rate during April 2000 was approximately 16 gpm, with influent VOC levels of 200 • g/L
and influent pesticide concentrations of less than 3 • g/L. The two liquid phase carbon units are
operated in series and adsorb VOCs and pesticides prior to discharge to the POTW. Carbon has not
been changed out to date. However, carbon is scheduled to be replaced due to the exceedance of the
discharge limit for chloroform.
The treatment system enclosure lacks sufficient space to access and make repairs to equipment. In
addition, it does not have spill control or alarm capability.
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3.0 SYSTEM OBJECTIVES, PERFORMANCE AND CLOSURE
CRITERIA
3.1 CURRENT SYSTEM OBJECTIVES AND CLOSURE CRITERIA
The OU1 ROD indicates that the goal of the system is to : (1) contain offsite migration of
groundwater from the PCX property with extraction wells in saprolite and bedrock onsite and
immediately south of the site, and (2) restore the aquifer to its unlimited use by pumping and treating.
The January 1999 Remedial Action Reports states that "based on a meeting between EPA and
Weston on January 17, 1996, groundwater remedial objectives were changed from cleanup of
contaminated groundwater in the overburden and bedrock beneath and downgradient ...to cleanup of
the contaminated groundwater in the overburden beneath the PCX property." The bedrock and
downgradient portions of the plume were to be addressed in OU3 (monitored natural attenuation was
chosen in the OU3 ROD for this area).
In practice, the OU1 system is being managed as a overburden contaminant mass removal system as
VOCs and pesticides are present in wells significantly downgradient of the site. It is unlikely that the
saprolite pumping is containing groundwater migration in bedrock and no available information
suggests otherwise. The system, when operational, removes approximately 17 grams/day VOCs and
0.3 grams/day of pesticides.
3.2 TREATMENT PLANT OPERATION GOALS
This is a continuously operating system, checked weekly. Groundwater is extracted from wells for
treatment and discharged to the POTW sanitary sewer system. Effluent water discharged to this
sewer must meet discharge requirements.
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4.0 FINDINGS AND OBSERVATIONS FROM THE RSE SITE VISIT
4.1 FINDINGS
The observations and recommendations given below are not intended to imply a deficiency in the
work of either the designers or operators, but are offered as constructive suggestions in the best
interest of the EPA and the public. These recommendations obviously have the benefit of the
operational data unavailable to the original designers.
4.2 SUBSURFACE PERFORMANCE AND RESPONSE
4.2.1 WATER LEVELS
Although water levels are routinely monitored weekly, it is unclear whether they have been used to
demonstrate a capture zone or calibrate the groundwater model. Quickflow model results indicated
that the recovery system was not capturing the entire plume in the July 2000 quarterly report.
4.2.2 CONTAMINANT LEVELS
A clear summary was not presented detailing whether or not contaminant concentrations have
increased or declined in the aquifer. A review of select monitor wells does not indicate a trend (see
Table 1). It should be noted, however, that this is a relatively recent system, it has operated for less
than 18 months total.
4.3 TREATMENT SYSTEM DOWN-TIME
There have been problems with system down-time. The sand filter backwash system float switches
in particular have required several replacement and frequent cleaning.
4.4 COMPONENTS OR PROCESSES THAT ACCOUNT FOR MAJORITY OF
COSTS
A cost breakdown was provided for the first year of OU1 system operation. This totaled $219, 250
(no laboratory analytical costs are included as EPA conducts that analysis internally). Expected
future O&M costs are about $150,000 per year.
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4.4.1 UTILITIES
Annual electric costs are expected to be $6,000 based on information from Roy F. Weston.
Electricity powers the compressor, transfer pumps, and building heat.
POTW discharge fees are expected to be about $40,000 per year based chiefly on volume rates which
we assume are about $5.00 per 1000 gallons.
4.4.2 NON-UTILITY CONSUMABLES AND DISPOSAL
The following items and approximate expected annual cost are included in this category:
Replace Liquid Phase GAC $8,400
Potassium Permanganate $ 0
Polymer $ 0
TOTAL $8,400
4.4.3 LABOR
AES technicians are responsible for weekly treatment system operation and water level
measurements. This function costs about $12,000 per year. Additional labor required for sampling
and analysis and maintenance is discussed below.
Non routine O&M is expected to total $12,000 per year. This consists mainly of equipment repairs
and replacements.
General consulting/project management costs are expected to total about $30,000 per year.
4.4.4 SAMPLING AND REPORTING
Monthly influent and effluent sampling and quarterly well sampling at 18 wells is conducted.
Analysis for VOCs, pesticides and metals is done for 14 well samples; pesticides only are done for
the other four wells. Quarterly reports are produced detailing the results. The sampling and
reporting totals about $40,000 per year.
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4.4.5
SUMMARY OF TOTAL COSTS
An estimate of total costs for the system is as follows (these are approximations based on somewhat
limited data):
Item
Consulting
Labor (O&M)
Utilities
Consumables
Sampling/Reporting
TOTAL (no analytical costs)
Estimated Annual Cost
$ 30 K/yr
$ 24 K/yr
$ 46 K/yr
$ 9 K/yr
$ 40 K/yr
$149 K/yr
4.5
RECURRING PROBLEMS OR ISSUES
4.5.1
SAND FILTERS
The original system design included metals precipitation with a baffled tank and sand filtration
system to capture oxidized metals and other particulate. During WRS's system operation, these
filters and appurtenant equipment required significant non-routine maintenance, labor, and materials.
With metal precipitation no longer being conducted, the baffle tank contains clear water. Elimination
or conversion of the sand filter system to a lesser maintenance bag filter system should be
considered. An additional benefit would be the increased space in the treatment enclosure.
4.5.2
SAND IN INFLUENT TANK
During the RSE visit coarse sand was present in the bottom of the influent tank indicating the
possible failure of a well screen. Individual well discharges should be checked to identify the
problem well, if any. Pump internals could be damaged by excessive sand in a well(s). Historic
pump performance records may indicate the problem well(s).
4.5.3
PIPING LEAKS
Leaks in the Schedule 80 PVC airline and at least one leak in the Schedule 40 PVC groundwater
influent line were reported. Replacing the underground PVC with a pipe such as HOPE which seems
to be much less susceptible to leaks and damage should be considered. Additionally, adding
secondary containment and alarm capabilities in the treatment enclosure should be considered.
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4.5.4 OPEN MONITORING WELLS
During the RSE visit monitoring wells at the site were found open. Some of these wells had bailers
and twine hanging in them. Although such practices may facilitate sampling, it provides a potential
exposure route to groundwater contamination and potential for further contamination of the
subsurface.
4.6 REGULATORY COMPLIANCE
The treatment requirements for discharge to the POTW are unusually stringent as shown in Table 2.
A recent exceedance of the limit for chloroform (0.19 • g/L) has led to suspension of treatment
system operation until GAC can be replaced. GAC adsorbs chloroform poorly so this may present
continuing problems. Consideration of aeration prior to the GAC may be warranted.
4.7 TREATMENT PROCESS EXCURSIONS AND UPSETS, ACCIDENTAL
CONTAMINANT/REAGENT RELEASES
The reported pipe leak discussed above and the lack of secondary containment and leak alarms is an
issue. Pipe breakage due to damage in the constricted treatment system is a possibility.
4.8 SAFETY RECORD
The plant appears to have had an excellent safety record.
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5.0 EFFECTIVENESS OF THE SYSTEM TO PROTECT HUMAN
HEALTH AND THE ENVIRONMENT
5.1 GROUND WATER
It is not clear whether or not the PCX property plume is being effectively captured by the current
extraction system. Recent modeling after eight (8) days of pumping did not demonstrate capture at
the southwest part of the site. Additionally pesticides and VOCs are present in bedrock wells 500
feet downgradient of the site. The effectiveness of the system for VOC remediation is minimal and
seems out of context with monitored natural attenuation being applied for the VOC plume away from
the Burlington Industries source area. However, the recovery wells (RW-1, RW-2, RW-3, and RW-4
specifically) are located in the main area of pesticide impact and could potentially be part of a system
to meet OU1 ROD goals for pesticides. Additional pumping from one or more bedrock wells in this
area would likely increase capture effectiveness as the saprolite and bedrock system are clearly
connected and have allowed significantly faster contaminant migration than expected based on
modeling. As the eastern recovery wells do not have pesticide impacts, pumping from them could be
suspended. This revised pumping scheme may also solve the chloroform exceedance issue.
5.2 SURFACE WATER
As the offsite plume is not being effectively captured, there is a potential threat to streams, wetlands,
and ponds. VOC discharges to surface water south of the site have been detected.
Improved sediment control at the PCX site should be implemented to prevent discharge of pesticide
impacted soil to the storm sewer.
The OU3 ROD and risk assessment work have indicated that VOC impacts in the surface water do
not present a significant risk to human health and the environment.
5.3 SOILS
Not a focus of this RSE. The excavation and treatment being conducted as OU2 should remove a
large portion of the source of pesticide impacts in groundwater.
5.4 OTHER
The site appearance could be considerably improved by cleanup of debris and simple landscaping
efforts.
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6.0 RECOMMENDATIONS
6.1 RECOMMENDED STUDIES TO ENSURE PROTECTIVENESS
6.1.1 UPDATE TARGET CONTAINMENT ZONE
The stated goal of the OU1 recovery system to cleanup contaminated groundwater in the overburden
beneath the PCX property should be reconsidered for the following reasons:
The overburden (saprolite) and bedrock are not separate systems as indicated by the
migration of pesticides in groundwater many times further from the site than
predicted based on overburden properties.
Despite soil remedies for OU3 VOC contamination, the VOC plume will continue to
enter the site from the north for some time as OU3 does not include containment of
VOC groundwater contamination. Chloroform concentrations will likely continue to
cause GAC replacement and POTW discharge issues.
The VOC plume outside of the former Burlington Industries facility is being
remediated by monitored natural attenuation per the OU3 ROD.
The east recovery wells RW-6, 7, 8, 9, and 10 are removing VOCs but little or no
pesticide mass from the aquifer.
VOCs and pesticides are migrating downgradient of the site in bedrock.
The existing system provides minimal cleanup of the large VOC plume and does not contain either
the VOC or pesticide plume. If the system goal is refined, for example to containment and cleanup
for the pesticide groundwater plume, then studies can be conducted so that containment of the plume
can be accomplished. Bedrock well pumping tests will be necessary and will likely lead to a revised
recovery system consisting of saprolite and bedrock wells on the west side of the existing recovery
network. Existing treatment equipment could be used for this revised recovery system. The
estimated capital cost for pumping tests, well installation, and adding about three bedrock wells to
the recovery system is $100,000.
6.1.2 SITE CLEANUP
There is debris on the site, the site is overgrown and there is no control of sediment flowing offsite.
Site cleanup, landscaping and installation of silt fence at the south side of the site should be
accomplished. The estimated initial cost is $10,000 with $5,000 per year for continuing upkeep.
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6.1.3 IMPROVED TREATMENT SYSTEM ENCLOSURE AND HEADER PIPING
The existing treatment system trailer is cramped, in poor condition, and has no secondary
containment or leak alarm system. PVC groundwater and air piping has had leaks. The equipment
should be relocated in a structure with a concrete floor, containment wall, sump with level alarm, and
adequate room to access and maintain equipment. An area within the warehouse would be ideal to
construct a treatment pad as the warehouse will provide a weather enclosure. The estimated capital
cost to build the pad, relocate equipment, heat and insulate equipment as necessary and replace air
and groundwater piping is $70,000.
6.2 RECOMMENDED CHANGES TO REDUCE COSTS
6.2.1 DISCHARGE TO SURFACE WATER (NPDES)
A large portion of annual O&M costs are spent paying the POTW to accept water that meets
extremely stringent (potable water) standards. Although obtaining NPDES permits is time
consuming and the biomonitoring tests may be difficult to pass, a continuing savings of about
$40,000 per year could result from a capital expenditure (pre-application bio-testing, application,
discharge line installation) of $20,000 to $30,000 (dependent on discharge location). Alternatively,
renegotiating the unusually stringent discharge levels with the POTW should be considered.
6.2.2 REMOVE THE SAND FILTER
It is likely that the sand filter system can be removed or replaced with bag filters with no detrimental
effect of GAC fouling. The sand filters could be bypassed and bag filters used temporarily to
confirm this prior to removing the sand filters. Replacement and disposal of the filters will cost
about $15,000 ($10,000 would have to be spent eventually on sand filter disposal) and will save an
estimated $8,000 per year in non-routine O&M costs. The integrity of each recovery well screen
should be checked to ensure that well sand pack from damaged well screens is not being pumped to
the treatment system prior to this work.
6.2.3 ELIMINATE SVOC AND METALS IN QUARTERLY WELL SAMPLING ANALYSIS
Metals are currently analyzed from 14 wells on a quarterly basis. Metals do not appear to be primary
contaminants of concern at the site, and the monitoring program could be modified accordingly. If
sufficient monitoring of natural attenuation parameters is not conducted as part of the OU3 remedy,
monitoring should continue for iron, manganese, arsenic, and other metals or major ions relevant to
natural attenuation of pesticides. Monitoring for other metals, however, could likely be reduced or
even eliminated. For metals with concentrations that exceed MCLs, the background concentrations
should be determined to confirm that cleanup of these metals is required. Elimination of analysis for
metals could save up to$8,000 per year based on commercial lab prices (EPA analyzes these samples,
so the costs are not included in the annual O&M). If elimination of the parameters is not feasible,
reducing the frequency of the analysis to annually could save up to $6,000 per year. Similarly,
reducing BNA analysis to an annual frequency would save about $9,000 per year. Bis(2-ethylhexyl)
phthalate is the only BNA that is potentially an issue at the site; it has been detected sporadically in a
few wells. Additionally, the RSE team agrees with the site managers and contractor that reducing the
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frequency of sampling on-site wells for VOCs and pesticides should be considered.
6.2.4 CONCENTRATE SYSTEM ON PESTICIDES
Suspending pumping from recovery wells on the east side of the site and possibly replacing the
system flow with additional (bedrock) wells in the pesticide impacted area will likely reduce the
influent chloroform concentration so that GAC replacement can be reduced form yearly or more
frequent changeouts to every two years. This is a potential savings of about $4,000 per year.
6.2.5 SUSPENSION OF PUMP AND TREAT
If in reconsidering the system goals, monitored natural attenuation is deemed suitable for the
pesticide plume (following source removal) as it has been for the VOC plume, recovering and
treating groundwater could be suspended. Sampling for parameters relevant to natural attenuation of
pesticides may be collected as part of the OU3 remedy, and review of this data, if it exists, may help
in evaluating the potential for natural attenuation for pesticides. If this data does not exist, limited
sampling could be conducted as part of OU1 to aid in evaluating natural attenuation. The current
system requires a significant expenditure for removal of a very small mass of contamination in an
area that apparently has minimal risk to human health and the environment. Suspension of the
system operation would save an estimated $103,000 per year.
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7.0 SUMMARY
In general, the RSE team found the system to be well operated and maintained. There are several
protectiveness issues that should be addressed, most notably reexamining the system goals and
improving the system enclosure. The anticipated costs of implementing these and other
recommendations related to protectiveness are summarized on the following "Cost Summary Table."
Several recommendations are also made to potentially reduce future operations and maintenance
costs. These opportunities to reduce cost arise from the fact that metals removal is not necessary and
the OU3 ROD impacts the context of OU1. Not considering the possibility of shutting the system
down completely, the recommendations below represent a reduction of $63,000 in annual O&M
costs for a potential net savings of more than $1.6 M over 30 years. The anticipated costs and
potential savings of implementing these and other recommendations to reduce costs are also
summarized on the following "Cost Summary Table."
Cost Summary Table
Recommendation
Update target capture zone
Site cleanup
Improve enclosure and piping
NPDES discharge
Eliminate sand filter
Reduce analysis frequency
Reason
Effectiveness
Effectiveness
Effectiveness
Cost reduction
Cost reduction
Cost reduction
Additional
Capital
Costs
($)
$100,000
$10,000
$70,000
$30,000
$15,000
$0
Estimated
Change in
Annual
Costs
($/yr)
($4,000)
$5,000
$0
($40,000)
($8,000)
($15,000)
Estimated
Change in
Lifecycle
Costs
($)*
($20,000)
$160,000
$70,000
($1,170,000)
($225,000)
($450,000)
'Estimated change in life-cycle costs assumes 30 years, no discount rate
(1) Costs in parentheses imply a cost reduction
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TABLES
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Table 1. Total VOCs and total pesticides at select wells.
Date
2/86
6/91
4/30/98
8/5/98
11/11/98
2/9/99
5/1 0/99
4/2000
Well
MW-2
113/0.48
64/0.19
NS/0.11
NS/0.07
115/0.09
NS/0.1
NS/0.11
NS/0.1 6
MW-3
60/113.6
0.65/33.43
NS/31.95
NS/13
0/>3.93
NS/12.07
NS/>6.04
NS/41 .94
MW-5S
NS/NS
99.7/4.16
0/6.31
0/1.17
0/7.1
0/6.11
0/9.1
0/4.71
MW-5D
NS/NS
174.9/4.34
29/8.12
97/8.96
72/>3.19
58/1 1 .3
95/0.57
30/6.54
W-24
NS/NS
NS/NS
203/0.011
147/0.189
2/0
45/0.041
0/ND
51/0.075
Total VOC/Total Pesticides (• g/L)
U = 0
NS - Not Sampling (W-24 was not installed in 1992, MW-5S, 5D, and 9 were not installed in 1986)
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Table 2. Groundwater remediation goals and POTW discharge limits.
Chemical
Barium
Beryllium
Chromium
Manganese
Vanadium
Alpha-Chlordane
Gamma-Chlordane
Dieldrin
Heptachlor Epoxide
Alpha-BHC
Beta-BHC
Lindane
Bromodichloromethane
Chloroform
Chloromethane
1,1-Dichloroethane
1,1-Dichloroethene
PCE
Trichloroethene
Bis(2-ethylhexyl)phthalate
MCL
2,000
4
100
200 (b)
-
2
2
-
0.2
-
-
0.2
100
100
-
-
7
5
5
6
NCGW
Standard
1,000
(c)
50
50
-
0.027
0.027
-
0.038
-
-
0.0265
-
0.19
-
-
7
0.7
2.8
-
Remediation
Goal (a)
(• 9/L)
988
0.013
50
50
98
0.027
0.027
0.0034
0.006
0.0086
0.03
0.027
0.41
0.19
2.9
0.71
0.07
0.7
2.8
3.9
Discharge
Limit
(• 9/L)
-
-
-
-
-
1
1
1
1
1
1
1
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FIGURES
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TREATMENT SYSTEM
ITY STORM SEWER
FCX-OU1
SITE MAP
Statesveille, redell County, NC
PR
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Solid Waste and
Emergency Response
(5102G)
542-R-02-008e
October 2002
vwwv.clu-in.org/rse
www.epa.gov/tio
U.S. EPA National Service Center
for Environmental Publications
P.O. Box 42419
Cincinnati, OH 45242-2419
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