EPA542-R-06-015
September 2006
fC1*" www.epa.gov/tio
www.clu-in.org/optimization
REMEDIATION SYSTEM EVALUATION (RSE)
ELLIS PROPERTY SUPERFUND SITE
EVESHAM AND MEDFORD TOWNSHIPS, NEW JERSEY
Report of the Remediation System Evaluation
Site Visit Conducted April 19, 2006
Final Report
September 2006
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NOTICE
Work described herein was performed by GeoTrans, Inc. (GeoTrans) for the U.S. Environmental
Protection Agency (U.S. EPA). Work conducted by GeoTrans, including preparation of this report, was
performed under EPA contract 68-C-02-092 to Dynamac Corporation, Ada, Oklahoma. Mention of trade
names or commercial products does not constitute endorsement or recommendation for use.
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EXECUTIVE SUMMARY
A Remediation System Evaluation (RSE) involves a team of expert hydrogeologists and engineers,
independent of the site, conducting a third-party evaluation of site operations. It is a broad evaluation that
considers the goals of the remedy, site conceptual model, above-ground and subsurface performance, and
site exit strategy. The evaluation includes reviewing site documents, visiting the site for up to 1.5 days,
and compiling a report that includes recommendations to improve the system. Recommendations with
implementation cost and cost savings estimates are provided in the following four categories:
Improvements in remedy effectiveness
Reductions in operation and maintenance costs
Technical improvements
Gaining site closeout
The recommendations are intended to help the site team identify opportunities for improvements. In
many cases, further analysis of a recommendation, beyond that provided in this report, may be needed
prior to implementation of the recommendation. Note that the recommendations are based on an
independent evaluation by the RSE team, and represent the opinions of the RSE team. These
recommendations do not constitute requirements for future action, but rather are provided for the
consideration of all stakeholders.
The Ellis Property Superfund Site is located in a rural area of Burlington County, New Jersey. Most of
the land at the site has not been developed. However, there is a building in a fenced area that is used to
house the remedial system, and land use is limited to the remedial activities. Land use in areas adjacent to
the site is predominantly agricultural, though some residential development has occurred and is
continuing to expand within a one-mile radius of the site. A drum recycling operation began in 1968 and
was terminated in 1978 after a fire; however, drums continued to be stored at the site into the early 1980s.
Soil and ground water contamination resulted from these historical facility operations. The site was listed
on the National Priorities List in September 1983. A remedial investigation and feasibility study (RI/FS),
was initiated in November 1985 and was completed in April 1992. A Record of Decision (ROD)
outlining the selected remedial action was issued in September 1992. The selected remedy included:
Excavation of contaminated soil and treatment/disposal at an approved off-site facility
Extraction of contaminated ground water from the shallow aquifer beneath the site
Treatment of contaminated ground water at a treatment facility to be built on the site
Disposal of contaminated ground water at the site by reinjection
Implementation of an environmental monitoring program
Excavation of contaminated soil was completed in 1998. Site clearing and construction of the pump and
treat (P&T) ground water remediation system was initiated in November 1999, with completion occurring
in June 2000. The P&T system was declared "operational and functional" in August 2000, at which time
long-term monitoring began. This RSE focuses on the ground water extraction, treatment, discharge, and
monitoring aspects of the remedy.
In general, the RSE team found a well-operated system. The observations and recommendations
contained in this report are not intended to imply a deficiency in the work of either the system designers
or operators, but are offered as constructive suggestions in the best interest of the EPA, NJDEP, and the
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public. These recommendations have the benefit of being formulated based on operational data
unavailable to the original designers.
Recommendations are provided in all four of the categories: remedy effectiveness, cost reduction,
technical improvement, and site closeout. The recommendations for improving system effectiveness are
as follows:
Install piezometer pairs along the length of the extraction trench to provide water level
measurements and use these measurements to evaluate plume capture.
Based on the above capture zone analysis, modify the treatment plant and potentially the
infiltration trench to increase the hydraulic capacity and extract and treat water at a higher rate.
Install two monitoring wells to improve plume characterization.
Conduct limited sampling of the wetlands to evaluate potential impacts.
Confirm that the ground water monitoring network provides enough information to evaluate
plume capture.
Recommendations for cost reduction include the following:
Optimize the process monitoring program by reducing the sampling frequency for some locations
from monthly to quarterly. Implementing this recommendation may save approximately $5,000
per year in analytical costs.
Avoid implementation of some items in the proposed work plan provided by another contractor.
The RSE team believes pursuing these items would not provide worthwhile information for
making future decisions at the site. Implementing this recommendation (i.e., not implementing
the identified aspects of the work plan) might save approximately $75,000 in upfront costs.
The recommendation for technical improvement involves installing a timer for wasting sludge from the
clarifier. The plant operator has been contemplating making this change, and the RSE team agrees with
this modification. The recommendation for site closure suggests that aggressive source removal may be
appropriate at this site, and the RSE team suggests that in-situ chemical oxidation with permanganate may
be an appropriate technology. The RSE team recommends a pilot test in one of the hot spot locations.
A table summarizing the recommendations, including estimated costs and/or savings associated with
those recommendations, is presented in Section 7.0 of this report.
in
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PREFACE
This report was prepared as part of a project conducted by the United States Environmental Protection
Agency Office of Superfund Remediation and Technology Innovation (U.S. EPA OSRTI) in support of
the "Action Plan for Ground Water Remedy Optimization" (OSWER 9283.1-25, August 25, 2004). The
objective of this project is to conduct Remediation System Evaluations (RSEs) at selected pump and treat
(P&T) systems that are jointly funded by EPA and the associated State agency. The project contacts are
as follows:
Organization
Key Contact
Contact Information
U.S. EPA Office of Superfund
Remediation and Technology
Innovation
(OSRTI)
Jennifer Hovis
2777 S. Crystal Drive, 5th floor
Arlington, VA 22202
Mail Code 5204P
phone: 703-603-8888
hovis.ienniferfSjepa.gov
Dynamac Corporation
(Contractor to U.S. EPA)
Daniel F. Pope
Dynamac Corporation
3601 Oakridge Boulevard
Ada, OK 74820
phone: 580-436-5740
fax: 580-436-6496
dpopeigjdynamac.com
GeoTrans, Inc.
(Contractor to Dynamac)
Doug Sutton
GeoTrans, Inc.
2 Paragon Way
Freehold, NJ 07728
phone: 732-409-0344
fax: 732-409-3020
dsutton@geotransinc .com
IV
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TABLE OF CONTENTS
NOTICE i
EXECUTIVE SUMMARY ii
PREFACE v
TABLE OF CONTENTS vi
1.0 INTRODUCTION 1
1.1 PURPOSE 1
1.2 TEAM COMPOSITION 2
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 HISTORICAL PERSPECTIVE 3
1.5.3 POTENTIAL SOURCES 4
1.5.4 HYDROGEOLOGIC SETTING 4
1.5.5 POTENTIAL RECEPTORS 5
1.5.6 DESCRIPTION OF GROUND WATER PLUME 5
2.0 SYSTEM DESCRIPTION 6
2.1 SYSTEM OVERVIEW 6
2.2 EXTRACTION SYSTEM 6
2.3 TREATMENT SYSTEM 6
2.4 MONITORING PROGRAM 7
3.0 SYSTEM OBJECTIVES, PERFORMANCE, AND CLOSURE CRITERIA 8
3.1 CURRENT SYSTEM OBJECTIVES AND CLOSURE CRITERIA 8
3.2 TREATMENT PLANT OPERATION STANDARDS 9
4.0 FINDINGS AND OBSERVATIONS FROM THE RSE SITE VISIT 10
4.1 FINDINGS 10
4.2 SUB SURF ACE PERFORMANCE AND RESPONSE 10
4.2.1 WATERLEVELS 10
4.2.2 CAPTURE ZONES 10
4.2.3 CONTAMINANT LEVELS 10
4.3 COMPONENT PERFORMANCE 11
4.3.1 EXTRACTION SYSTEM TRENCH, WELLS, PUMPS, AND HEADER 11
4.3.2 SOLIDS SETTLING AND EQUALIZATION TANKS 11
4.3.3 METALS PRECIPITATION SYSTEM 11
4.3.4 FILTERS 12
4.3.5 AIR STRIPPER 12
4.3.6 VAPOR PHASE GRANULAR ACTIVATED CARBON UNITS 12
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4.3.7 EFFLUENT TANK AND INFILTRATION TRENCH 12
4.3.8 SLUDGE HANDLING 12
4.4 COMPONENTS OR PROCESSES THAT ACCOUNT FOR MAJORITY OF ANNUAL COSTS 13
4.4.1 UTILITIES 13
4.4.2 NON-UTILITY CONSUMABLES AND DISPOSAL COSTS 13
4.4.3 LABOR 13
4.4.4 CHEMICAL ANALYSIS 14
4.5 RECURRING PROBLEMS OR ISSUES 14
4.6 REGULATORY COMPLIANCE 14
4.7 TREATMENT PROCESS EXCURSIONS AND UPSETS, ACCIDENTAL CONTAMINANT/REAGENT
RELEASES 14
4.8 SAFETY RECORD 14
5.0 EFFECTIVENESS OF THE SYSTEM TO PROTECT HUMAN HEALTH AND THE
ENVIRONMENT 15
5.1 GROUND WATER 15
5.2 SURF ACE WATER 15
5.3 AIR 15
5.4 SOIL 15
5.5 WETLANDS AND SEDIMENTS 16
6.0 RECOMMENDATIONS 17
6.1 RECOMMENDATIONS TO IMPROVE EFFECTIVENESS 17
6.1.1 IMPROVE CAPTURE ZONE EVALUATION WITH INSTALLATION OF PIEZOMETER
PAIRS 17
6.1.2 BASED ON CAPTURE ZONE EVALUATION, CONSIDER MODIFICATION OF
TREATMENT PLANT AND INJECTION TRENCH TO INCREASE HYDRAULIC
CAPACITY 18
6.1.3 IMPROVE SITE CHARACTERIZATION WITH INSTALLATION OF Two MONITORING
WELLS 19
6.1.4 CONDUCT LIMITED SAMPLING OF THE WETLANDS SURFACE WATER AND
SEDIMENTS AS INDICATED IN THE FIVE-YEAR REVIEW 19
6.1.5 CONFIRM THAT GROUND WATER MONITORING NETWORK PROVIDES ENOUGH
INFORMATION TO EVALUATE CAPTURE 19
6.2 RECOMMENDATIONS TO REDUCE COSTS 20
6.2.1 REVISE PROCESS MONITORING PROGRAM 20
6.2.2 CONSIDER NOT IMPLEMENTING ASPECTS OF THE PROPOSED WORK PLAN 20
6.3 RECOMMENDATIONS FOR TECHNICAL IMPROVEMENT 22
6.3.1 INSTALL TIMER FOR WASTING SLUDGE FROM CLARIFIER 22
6.4 CONSIDERATIONS FOR GAINING SITE CLOSE Our 22
6.4.1 PILOT IN-SITU CHEMICAL OXIDATION WITH PERMANGANATE FOR AGGRESSIVE
SOURCE REMOVAL 22
6.5 CONSIDERATIONS FOR GAINING SITE CLOSE Our 23
7.0 SUMMARY 25
VI
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Figures
Figure 1 -1. Site Map
Figure 1-2. Extent of Contamination
vn
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1.0 INTRODUCTION
1.1 PURPOSE
During fiscal years 2000 and 2001 Remediation System Evaluations (RSEs) were conducted at 20 Fund-
lead pump and treat (P&T) sites (i.e., those sites with P&T systems funded and managed by EPA and the
States). Due to the opportunities for system optimization that arose from those RSEs, EPA OSRTI has
incorporated RSEs into a larger post-construction complete strategy for Fund-lead remedies as
documented in OSWER Directive No. 9283.1-25, Action Plan for Ground Water Remedy Optimization.
OSRTI has since commissioned RSEs at 10 additional Fund-lead sites with P&T systems. An
independent EPA contractor is conducting these RSEs, and representatives from EPA OSRTI are
participating as observers.
The Remediation System Evaluation (RSE) process was developed by the US Army Corps of Engineers
(USAGE) and is documented on the following website:
http://www.environmental.usace.army.mil/library/guide/rsechk/rsechk.html
An RSE involves a team of expert hydrogeologists and engineers, independent of the site, conducting a
third-party evaluation of site operations. It is a broad evaluation that considers the goals of the remedy,
site conceptual model, above-ground and subsurface performance, and site exit strategy. The evaluation
includes reviewing site documents, visiting the site for up to 1.5 days, and compiling a report that
includes recommendations to improve the system. Recommendations with implementation cost and cost
savings estimates are provided in the following four categories:
Improvements in remedy effectiveness
Reductions in operation and maintenance costs
Technical improvements
Gaining site closeout
The recommendations are intended to help the site team (the responsible party and the regulators) identify
opportunities for improvements. In many cases, further analysis of a recommendation, beyond that
provided in this report, may be needed prior to implementation of the recommendation. Note that the
recommendations are based on an independent evaluation by the RSE team, and represent the opinions of
the RSE team. These recommendations do not constitute requirements for future action, but rather are
provided for the consideration of all site stakeholders.
The Ellis Property Superfund Site (the "site") was selected by EPA OSRTI based on a recommendation
from EPA Region 2 and the New Jersey Department of Environmental Protection (NJDEP). In particular,
the site team is planning further activities and wanted the third-party perspective of an RSE to provide
input on these activities. This report provides a brief background on the site and current operations, a
summary of observations made during a site visit, and recommendations regarding the remedial approach.
The cost impacts of the recommendations are also discussed.
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1.2 TEAM COMPOSITION
The team conducting the RSE consisted of the following individuals:
Valerie Lane, Hydrogeologist, GeoTrans, Inc.
Peter Rich, Civil and Environmental Engineer, GeoTrans, Inc.
Doug Sutton, Water Resources Engineer, GeoTrans, Inc.
The RSE team was also accompanied by the following observers:
Matthew Charsky from EPA OSRTI
Sherri Clark from EPA OSRTI
Jennifer Hovis from EPA OSRTI
1.3 DOCUMENTS REVIEWED
Author
NJDEP
ACRES
NJDEP
ACRES
NJDEP
Handex
USEPA
The Louis Berger
Group and PMK
Group
Date
9/30/1992
8/1998
Ongoing
1999
N/A
3/2005 to
12/2005
9/2005
1 1/2005
Title
Record of Decision
Design Report Groundwater Remediation/Remedial Design
Services
Spreadsheet with historical data
Design drawings
MAROS monitoring evaluation output
Ellis Property Groundwater Remediation System Monthly
System Operations Reports
Five -Year Review
Pre-design Investigation Workplan
1.4 PERSONS CONTACTED
The following individuals associated with the site were present for the visit:
Carlton Bergman, Project Manager, Bureau of Design and Construction, NJDEP
Chad VanSciver, Operations Project Manager, Bureau of Construction, NJDEP
Tom O'Neill, Division of Publicly Funded Site Remediation, NJDEP
John Esposito, Plant Operator, Handex
Rob Alvey, Geologist, EPA Region 2
Richard Ho, the EPA Remedial Project Manager, was not available for the site visit.
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1.5 SITE LOCATION, HISTORY, AND CHARACTERISTICS
1.5.1 LOCATION
The Ellis Property Superfund Site (the "site") is located in a rural area of Burlington County, New Jersey,
in the vicinity of Sharp Road and Evesboro-Medford Road. It is situated on the eastern side of Sharp
Road, approximately 2,000 feet north of Evesboro-Medford Road. The site is identified on the Evesham
Township tax map as Block 14, Lot 4. The total acreage of land at the site is 36 acres, with 24 acres
situated in Evesham Township and 12 acres situated in Medford Township.
Most of the land at the site has not been developed. However, there is a building in a fenced area that is
used to house the remedial system, and land use is limited to the remedial activities. The remainder of the
land at the site is primarily covered by grass and native vegetation. The easternmost portion of the site
has been identified by the U.S. Fish and Wildlife Service as a palustrine wetland.
Land use in areas adjacent to the site is predominantly agricultural. Cultivated fields border the site to the
north and south; another lies to the west on the other side of Sharp Road. Some residential development
has occurred within a one-mile radius of the site, with new development in the area continuing.
1.5.2 HISTORICAL PERSPECTIVE
The site, on which dairy farming activities had been previously conducted, was purchased by Irving and
Reba Ellis in 1968. Subsequently, a drum recycling operation was conducted on about four acres of the
site. Activities associated with the drum recycling operation included drum delivery, storage, and
reconditioning that consisted of rinsing or cleaning. After reconditioning, the drums were resold. Drum
recycling activities were terminated in 1978 after a fire and resulting structural damages; however, drums
continued to be stored at the site into the early 1980s.
Initial investigation of the site by the New Jersey Department of Environmental Protection and Energy
(currently referred to as the New Jersey Department of Environmental Protection, "NJDEP") occurred in
September 1980. At that time, a two-story building, in which several washing tanks with troughs were
found, a storage area, and three sheds were present at the site. Numerous drums and other containers
containing unidentified liquids or substances were found in the building and sheds. Approximately 100
plastic 55-gallon drums were found distributed near the sheds. Hundreds of other drums and containers
were randomly distributed across the site. Removal of the drums from the site occurred in stages,
beginning in March 1983 when NJDEP removed about 100 drums from the site. In late 1989 the removal
process for an additional 218 drums containing hazardous waste material and 400 empty drums was
begun. Drum removal from the site was completed in April of 1990.
Listing of the site on the National Priorities List occurred in September 1983. A remedial investigation
and feasibility study (RI/FS), initiated in November 1985, was completed in April 1992. A Record of
Decision (ROD) outlining the selected remedial action was issued in September 1992. The selected
remedy included:
Excavation of contaminated soil and treatment/disposal at an approved off-site facility
Extraction of contaminated ground water from the shallow aquifer beneath the site
Treatment of contaminated ground water at a treatment facility to be built on the site
Disposal of treated ground water at the site by reinjection
Implementation of an environmental monitoring program
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Excavation of contaminated soil was completed in 1998. Site clearing and construction of the ground
water remediation system was initiated in November 1999, with completion occurring in June 2000. The
P&T system was declared "operational and functional" in August 2000, at which time long-term
monitoring began. The initial Five-Year Review Report for the site was issued in September 2005.
Figure 1-1 provides a map of the site indicating key site features including parts of the P&T system and
site monitoring wells.
1.5.3 POTENTIAL SOURCES
The contents of drums found at the site consisted of acids, heavy metals, oils, grease, and a variety of
organic compounds. Evidence of spills from leaking, corroded drums to the ground surface was present
in several areas. PCE, in the solvent phase, was observed in soil during construction that occurred from
1999 to 2000.
Analytical results showed that soils at the site were contaminated with hydrochloric acid, heavy metals
(including arsenic and lead), oil and grease, polychlorinated biphenyls (PCBs) and other semi-volatile
compounds, such as bis(2-ethylhexyl)phthalate. At the time the ROD was issued in 1992, the
concentrations of arsenic, lead, and PCBs exceeded USEPA risk-based soil remediation levels.
Analyses of ground water, also performed in 1992, showed that metals and volatile organic compounds
(VOCs) were present in ground water. Detected metals included antimony, arsenic, beryllium, nickel,
chromium, and lead. Detected VOCs included 1,2-dichloroethylene (1,2-DCE); methylene chloride;
tetrachloroethylene (PCE); trichloroethylene (TCE); and 1,1,2-trichloroethane (1,1,2-TCA). The ground
water concentrations of the metals, except lead, exceeded drinking water maximum contaminant levels
(MCLs). The ground water concentrations of all of the VOCs exceeded MCLs.
During the RI surface water and sediment samples from the wetlands and the discharge area to the
wetlands were analyzed. The results from these analyses showed that the surface waters contained metals
and the sediments contained metals and PCBs. The results indicated exceedances for copper, lead, and
zinc in surface water and for PCBs, 4,4-DDE (breakdown product of DDT), cadmium, chromium, lead,
mercury, and zinc in sediments.
1.5.4 HYDROGEOLOGIC SETTING
Geographically the site is located in the central portion of the Coastal Plain Physiographic Province.
Topography across the site generally is at its highest in the western and southern areas of the site. The
maximum surface elevation of about 67 feet above mean sea level (amsl) occurs near Sharp Road and the
minimum surface elevation of about 50 feet amsl occurs in the wetlands in the eastern part of the site.
Surface drainage flows from west to east, into the wetlands. The wetlands drain into a nearby stream,
Sharps Run, which is a tributary of Rancocas Creek.
The site is underlain by an aquifer system. Unconsolidated deposits of silty sand and clay lenses are
present at the surface. The Hornerstown Formation, the shallow aquifer that is also comprised of silty
sand and clay lenses, is present beneath the surficial unconsolidated deposits. The thickness across the
site of the Hornerstown Formation is between about 7 and 20 feet. Ground water is typically encountered
in the Hornerstown Formation between 3.5 to 15 feet below ground surface. The direction of ground
water flow in this shallow aquifer is to the east and east-northeast. Aquifer tests used to estimate the
aquifer parameters of the shallow aquifer indicate that hydraulic conductivity is between 0.41 and 1.63
feet per day (USEPA) to as much as 3.0 feet per day (Berger/PMK). The site team has identified a sand
channel within the Hornerstown Formation oriented parallel to flow that may serve as a preferential flow
path for contamination.
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The Navesink Formation, which is comprised of interbedded clay and sand, lies below the Hornerstown
Formation. The clay content increases with depth, reducing permeability. The thickness across the site of
the Navesink Formation is between about 51 and 57 feet.
An aquifer, the Wenonah-Mount Laurel Sand, is present beneath the Navesink Formation. This aquifer is
a major source of potable water for domestic wells located near the site. The thickness across the site of
the Wenonah-Mount Laurel Sand is greater than 30 feet.
Another aquifer system, comprised of the Magothy-Raritan aquifers, is present beneath the Wenonah-
Mount Laurel Sand. The Magothy-Raritan aquifers, separated by clay layers from the upper aquifers, are
more productive than the upper aquifers. Combined, the Wenonah-Mount Laurel Sand and the Magothy-
Raritan aquifers are a major source of municipal water for the area.
1.5.5
POTENTIAL RECEPTORS
Ground water contamination appears to be restricted to the shallow aquifer. Ground water beneath the
site has been designated part of the New Jersey Coastal Plain Sole Source Aquifer, and it is considered to
be "Class II, potable water." While the shallow aquifer is relatively unproductive and does not serve as a
drinking water source, it does provide recharge to the aquifers below. Other facilities near the site
(including the public works facility, ball fields, and commercial establishments) have well water for
irrigation but use public water for potable water. Therefore, the site team does not know of any potable
water wells near the site. Sharps Run (surface water) and wetlands at the site are potential ecological
receptors of contaminated ground water.
1.5.6
DESCRIPTION OF GROUND WATER PLUME
The contaminants of concern at the site are TCE and PCE. Figure 1-2 (with information gathered from
Figure 6 of the November 2005 Pre-Design Investigation Workplan) shows interpretations of the TCE
and PCE distributions at the site as of October 2004. Based on this map the TCE plume appears to extend
from behind the treatment facility in the vicinity of MW-8 into the wetlands in the vicinity of MW-19.
The following table indicates TCE concentrations from three recent sampling events.
TCE Concentration (ug/L)
Date
October 2004
March 2005
July 2005
MW-2
7,400
2,800
11,500
MW-5
2.3
12
15
MW-6
5,000
580
5,900
MW-7
6.7
3 J
7.1
MW-8
ND
1 J
0.45
MW-10
ND
U
2.1
MW-18
850
370
393
Figure 3.5 from the August 1998 Design Report by Acres International Corporation shows the PCE
distribution at the site as of August 1995. Based on this map, the PCE distribution is localized in the
vicinity of MW-7. The following table indicates PCE concentrations from the three most recent sampling
events.
PCE Concentration (ug/L)
Date
October-04
March-05
July-05
MW-2
ND
ND
ND
MW-5
ND
ND
ND
MW-6
ND
ND
ND
MW-7
12
2J
3.8
MW-8
ND
ND
ND
MW-10
ND
9J
3.4
MW-18
ND
ND
ND
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2.0 SYSTEM DESCRIPTION
2.1 SYSTEM OVERVIEW
The P&T system, which became operational and functional in August 2000, consists of an extraction
trench, two source area extraction wells, a treatment plant, and an infiltration trench. The extraction and
injection networks are designed to form a closed loop such that ground water that is reinjected at the
trench is extracted, forming a recirculation pattern.
2.2 EXTRACTION SYSTEM
The extraction trench is approximately 375 feet long and ranges from 12 to 17 feet deep. It is 4 feet wide
and filled with sand and stone. A 6-inch diameter perforated pipe directs flow in the trench toward two
sumps labeled Manhole-1 (MH-1) and Manhole-2 (MH-2). Electrical submersible pumps capable of
pumping 20 gpm from the bottoms of MH-1 and MH-2 pump the water to the treatment plant through
individual 1-inch discharge lines. Two extraction wells (PW-1 and PW-2) are located in high-
concentration areas for "hot-spot" remediation. PW-1 is 23 feet deep and PW-2 is 21 feet deep, and both
wells have 10-foot screened intervals. A 22-inch borehole was used to drill the wells, and the casings are
8-inches in diameter. The electrical submersible pumps in these wells pump ground water to the
treatment plant through separate 1-inch discharge lines. Extraction rates from these components of the
extraction system cycle on and off providing an average flow rate of approximately 3.5 gpm. It is
believed that the cycling is caused by limited capacity of the treatment plant and infiltration trench and
not by the potential yield from the extraction network. Given an average influent concentration of
approximately 4,000 ug/L of total VOCs, the average rate of contaminant mass extracted is approximately
0.17 pounds per day.
3.5 gal 3.785L 4,000 ug 1kg 2.2 Ibs 1440 min 0.171bs
X X X 2 X X =
min gal L 109ug kg day day
2.3 TREATMENT SYSTEM
The treatment system is comprised of a solids settling tank, equalization tank, metals precipitation system,
bag filters, pH, adjustment, air stripper, and effluent tank with a gravity discharge to the infiltration
trench. The treatment system was designed to treat between 3 and 5 gpm with a maximum capacity of 15
gpm. Actual capacity appears to be approximately 7 gpm based on operating parameters at the time of
the RSE. The treatment system treats on average 3.5 gpm of extracted water, but approximately 2.5 to 3
gpm is recycled from the clarifier to the head of the plant such that the metals treatment system is treating
approximately 6 to 7 gpm on average. Air stripper offgas is treated by a 300-pound vapor phase granular
activated carbon (GAC) unit, and sludge from the clarifier is thickened and then dewatered by a filter
press.
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2.4 MONITORING PROGRAM
The ground water monitoring program historically consisted of quarterly sampling of 38 monitoring wells
for VOCs. However, the July and September 2005 events included 30 monitoring wells each. The site
team recently optimized the monitoring program using MAROS software and has decided to reduce the
sampling frequency to annual events and to reduce the number of monitoring wells sampled per event to
12.
Process monitoring includes monthly sampling for VOCs, metals, total dissolved solids, and total
suspended solids in the blended process water from the equalization tank (which also includes recycled
water from the metals removal system) and treatment plant effluent. It also includes quarterly sampling
for the same parameters at MH-1, MH-2, PW-1, and PW-2 and for VOCs in the vapor phase GAC
effluent.
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3.0 SYSTEM OBJECTIVES, PERFORMANCE, AND
CLOSURE CRITERIA
3.1 CURRENT SYSTEM OBJECTIVES AND CLOSURE CRITERIA
The remedial action objectives stated in the ROD for the site are as follows:
Soil
Prevent contact with contaminated soil, which represents an unacceptable risk, or reduce
contaminant concentrations in the soil below risk-based levels
Prevent further migration of soil contaminants into the ground water
Prevent migration of contaminated soils off site
Ground Water
Prevent the migration of contaminated ground water off site
Prevent the migration of contaminated ground water into the underlying aquifers
Return the aquifer to its designated use as a source of drinking water by reducing contaminant
concentrations in the shallow ground water to drinking water quality (see criteria below)
Contaminant of Concern
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium (total)
Copper
Cyanide
1 , 1 -Dichloroethene
1 ,2-Dichloroethene
Lead
Methylene Chloride
Nickel
Selenium
Silver
1 , 1 ,2-Trichloroethane
Tetrachloroethene (PCE)
Trichloroethene (TCE)
Cleanup Criteria (jig/L)
6
50
1000
4
10
50
1300
200
2
10
15
5
100
100
50
5
1
1
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3.2 TREATMENT PLANT OPERATION STANDARDS
Treated ground water is discharged to the onsite infiltration trench. Discharge is governed by a New
Jersey Pollution Discharge Elimination System (NJPDES) Permit Equivalent. Because the extraction and
injection system for a closed loop, all water reinjected is theoretically extracted. As a result, the discharge
criteria are that the effluent concentrations must be reduced to 5% or less than the influent concentrations
or to meet the standards noted above, whichever is higher.
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4.0 FINDINGS AND OBSERVATIONS FROM THE
RSE SITE VISIT
4.1 FINDINGS
The observations provided below are not intended to imply a deficiency in the work of the system
designers, system operators, or site managers but are offered as constructive suggestions in the best
interest of the EPA, NJDEP, and the public. These observations have the benefit of being formulated
based upon operational data unavailable to the original designers. Furthermore, it is likely that site
conditions and general knowledge of ground water remediation have changed over time.
4.2 SUBSURFACE PERFORMANCE AND RESPONSE
4.2.1 WATER LEVELS
Water level measurements have been collected on a quarterly basis during ground water sampling events;
however, the data are not routinely used for generating potentiometric surface maps. A cursory review of
recent water level data demonstrates that overall ground water flow is similar to that used during system
design. Vertical gradients vary across the site but, in general, are upward or neutral in the upgradient
portion of the site and are likely influenced by the trench near the downgradient portion of the site. No
vertical gradient information is available downgradient of the extraction trench.
4.2.2 CAPTURE ZONES
Evaluation of capture has not been documented since the P&T system began operation. Evaluations
during project design suggested a pumping rate of 3.5 gpm to provide capture while minimizing
drawdown in the wetlands; however, the heterogeneity of subsurface materials and hydraulic conductivity
make it difficult to rely on this pre-design evaluation. In addition, the heterogeneity (e.g., the sand
channel) makes it difficult to conduct a water budget analysis or use potentiometric surface maps to
interpret capture. Capture evaluations would most likely need to rely on evaluating local hydraulic
gradients from pairs of water level measurements or on decreasing concentrations downgradient of the
extraction trench. There currently are no pairs of water level measurements that are adequately located to
evaluate hydraulic gradients from the downgradient of the trench toward the trench. The best indication
of capture is that TCE concentrations in MW-18 have decreased by one to two orders of magnitude since
the P&T system began operating. A continuing downward trend that eventually reaches background
conditions would indicate complete capture, whereas a downward trend that asymptotically approaches a
concentration above background would indicate incomplete capture. This form of capture zone
evaluation would take several years of monitoring to conduct.
4.2.3 CONTAMINANT LEVELS
TCE concentrations in the source areas in the vicinity of MW-2 and MW-6 consistently remain elevated
above 5,000 ug/L, but this represents a decrease from high concentrations above 60,000 ug/L in MW-2
and 30,000 ug/L in MW-6. These persistently elevated concentrations may indicate that residual source
material remains in these areas and/or that the formation is relatively tight such that the contamination is
not easily flushed toward the extraction trench. TCE concentrations at MW-5, MW-7, MW-8, MW-10,
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and MW-18 have consistently decreased. Concentrations in all wells with detections fluctuated during
2003 and 2004 when the site team experimented with various sampling methods (including diffusion bag
samplers), but the site team has since returned to the original technique used at the site, which is sampling
using a three volume purge. TCE concentrations in other monitoring wells are undetectable, providing
both general horizontal and vertical delineation. However, the monitoring network is too sparse to
determine which specific areas within this general area are impacted. That is, the contamination at MW-2
may be much more limited in extent than is represented by the monitoring network.
PCE has been detected at concentrations above 1 ug/L in wells MW-2, MW-6, MW-7, MW-9, MW-10,
and MW-18. The highest PCE concentrations have been detected in MW-7. In MW-7 and MW-10, PCE
concentrations have generally decreased from the high of 33,000 ug/L to approximately 10 ug/L. In all
other wells, PCE has not been detected since 2003.
4.3 COMPONENT PERFORMANCE
4.3.1 EXTRACTION SYSTEM TRENCH, WELLS, PUMPS, AND HEADER
Although the total flow for the P&T system is lower than the design flow, each of these components has
functioned as expected. Extraction rates from these components of the extraction system cycle on and
off. Flow from the trench cycles on and off because of the limited capacity of the treatment plant and
infiltration trench. Flow from the extraction wells cycles on and off because of the limited yield of these
wells.
4.3.2 SOLIDS SETTLING AND EQUALIZATION TANKS
Extracted ground water discharges to a 500-gallon solids settling tank, which also receives filtrate from
the filtrate storage tank and water from the building sump. Water from the solids settling tank flows by
gravity into a 2,000-gallon equalization tank. Solids are transferred from the solids settling tank during
each visit by the plant operator (e.g., three times per week). Dissolved iron in the ground water
precipitates in the oxygenated conditions in the equalization tank, requiring frequent attention from the
operator and routine inspection of y-strainers between the equalization tank and the subsequent process
pumps.
4.3.3 METALS PRECIPITATION SYSTEM
The site team originally used ferric chloride as a coagulant, but recently switched to a proprietary formula
from the vendor. The plant operator reports that about 1 gallon per day of coagulant is used and about 0.5
gallons per day of sodium hydroxide is used for metals precipitation. This is a significant reduction from
previous usage, which included approximately 5 gallons per day of sodium hydroxide. Polymer is also
added to aid in flocculation. The clarifier is one of the capacity limiting steps of the treatment process
and reaches its peak capacity at approximately 7 gpm. Sludge from the bottom of the clarifier is
continuously wasted rather than being wasted periodically. This increases the amount of water that is
recycled through the plant. Of the 7 gpm that is currently flowing through the metals removal system,
approximately half of it is recycled water. Approximately once a week to once every two weeks, the
operator conducts partial blowdowns of the clarifier and acid washes the lines after the clarifier to reduce
scaling.
The metals precipitation unit is used primarily to remove iron and manganese to prevent fouling of the air
stripper. Concentrations of metal contaminants of concern that were listed in the ROD decreased when
pumping began and have not required treatment.
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4.3.4 FILTERS
The filtration system includes two parallel sets of bag filters arranged in series. The first set of parallel
filters historically had 100 micron filters and the second parallel set had 50 micron filters. However, due
to a change in the coagulant used in the metals precipitation system, the turbidity coming from the
clarifier was reduced, and the bag filter sizes were reduced to 50 microns and 25 microns. The plant
operator changes the filters three times per week.
4.3.5 AIR STRIPPER
The air stripper is a tray aerator that is providing greater than 99% removal of VOCs. Influent VOC
concentrations have averaged from 3,000 ug/L to 5,000 ug/L, and effluent VOC concentrations have
historically ranged from "non-detect" to as high as 21 ug/L. Although this removal efficiency would not
be sufficient for typical discharge scenarios to ground water or surface water, the P&T
injection/extraction systems operate as a closed loop. Therefore, all water that is reinjected through the
infiltration trench is theoretically extracted by the extraction wells or extraction trench. Under this
scenario, the effluent concentration for each parameter only needs to be less than or equal to 5% of the
respective influent concentration. Therefore, if the influent VOC concentration is 3,000 ug/L, the effluent
VOC concentration would need to be less than 150 ug/L.
4.3.6 VAPOR PHASE GRANULAR ACTIVATED CARBON UNITS
There is one 300-pound vapor GAC unit that is used to treat the offgas from the air stripper. The influent
and effluent to this unit is sampled weekly using a flame-ionization detector, the air flow velocity is
measured weekly, the unit effluent is sampled quarterly for VOCs, and the unit is replaced every six to
nine months.
4.3.7 EFFLUENT TANK AND INFILTRATION TRENCH
The infiltration trench is approximately 200 feet long and 4 feet wide. The trench consists of a 2-inch
perforated HDPE line buried approximately 2 feet below ground surface, low permeability fill above the
line and underdrain stone around and 3 feet beneath the line. Filter fabric separates the underdrain stone
from underdrain sand which extends to the Navesink formation approximately 8 to 12 feet below the
stone. The trench is gravity fed from the effluent tank. The site team has not experienced significant
fouling of the trench, but they have blown air through the trench approximately once per year in an
attempt to reduce fouling. The site team reports that the infiltration trench, in addition to the clarifier, is
one of the capacity limiting aspects of the system.
4.3.8 SLUDGE HANDLING
Sludge from the clarifier is continuously wasted with water recirculating through the system. Solids are
generated at a rate that typically requires filter press drops once per week, but filter drops have been
conducted as frequently as eight times per month.
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4.4 COMPONENTS OR PROCESSES THAT ACCOUNT FOR MAJORITY OF ANNUAL
COSTS
The project team provided the monthly O&M costs for the past several years for evaluation. The costs
provided include approximately $19,000 per month for the O&M contractor, $1,000 per month for
electrical costs, and additional costs for grass cutting and chemicals. Historical grass cutting appears to
have cost approximately $20,000 per year. Therefore, the total annual contractor cost for O&M is
approximately $250,000 per year. There are additional costs to EPA and NJDEP for the NJDEP staff
working on the project. A breakdown of annual costs was not provided by the site team. The RSE team
has attempted to breakdown these costs into a variety of categories in the following table.
Item Description
Labor: Project management, reporting, etc.
Labor: System operation
Labor: Ground water sampling
Utilities: Electricity
Utilities: Other
Non-utility Consumables (GAC, chemicals, etc.)
Discharge or disposal costs
Analytical costs
Other (parts, routine maintenance, etc.)
Total Estimated Annual Cost
Estimated Cost*
$35,000
$140,000
$18,000
$12,000
$6,000
$8,000
$5,000
$20,000
$6,000
$250,000
4.4.1
* The total estimated cost is consistent with that reported by the site team. The values
for each of the individual cost categories have been estimated by the RSE team.
UTILITIES
The primary utility cost is for electricity. Electricity usage and costs suggest a unit rate of approximately
$0.09 per kWh when both electrical usage and demand are considered. Other utilities include phone,
public water, and trash disposal.
4.4.2
NON-UTILITY CONSUMABLES AND DISPOSAL COSTS
Non-utility consumables consist of vapor phase GAC, bag filters, sodium hydroxide, polymer, coagulant,
and disposable personal protective equipment.
4.4.3
LABOR
The treatment plant operator is present on site three times per week. Assuming each site visit is 8 hours at
an hourly rate of $108 (provided by NJDEP), this translates to an annual cost for O&M labor of
approximately $135,000 per year. An additional $5,000 per year might be needed for engineering
support, additional labor for complex tasks, and responding to alarms. Ground water sampling will be
conducted on an annual basis. Assuming all 38 wells are sampled and gauged in 9 days at an average cost
of $2,000 per day for labor and equipment, the cost for the labor and equipment for ground water
sampling will likely be approximately $18,000. Project management, including the cost of an annual
ground water report (which is expected for future events), is estimated at $35,000 per year
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4.4.4 CHEMICAL ANALYSIS
Chemical analysis is provided for both the annual ground water monitoring event and the routine process
monitoring. The ground water monitoring might include 50 samples, including QA/QC samples, for a
total of approximately $5,000 (assumes $100 per sample). The process monitoring includes the
following:
monthly samples for VOCs, metals, TSS, and TDS at MH-1, the equalization tank, and the
treatment plant effluent
quarterly samples for VOCs, metals, TSS, and TDS at MH-2, PW-1, and PW-2
quarterly samples for VOCs of the GAC effluent
Including QA/QC samples and assuming $100 per aqueous VOC analysis, $160 per inorganic analysis
(i.e., metals, TSS, and TDS), and $150 per VOC air analysis, the total process monitoring cost is
approximately $20,000.
4.5 RECURRING PROBLEMS OR ISSUES
The plant operator mentions routine issues with solids precipitation in the equalization tank and non-
optimal wasting of solids from the clarifier. However, these issues have not resulted in problems
complying with the discharge requirements. Rather, they have limited the capacity of the P&T system,
which may adversely affect the ability of the system to provide capture.
4.6 REGULATORY COMPLIANCE
Since operation of the pretreatment system, discharge standards are routinely met and no issues regarding
compliance were reported by the site team.
4.7 TREATMENT PROCESS EXCURSIONS AND UPSETS, ACCIDENTAL
CONTAMINANT/REAGENT RELEASES
The site team reports that there have not been any uncontrolled releases of contaminants or reagents.
4.8 SAFETY RECORD
The site team reports no health and safety incidents.
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5.0 EFFECTIVENESS OF THE SYSTEM TO PROTECT HUMAN
HEALTH AND THE ENVIRONMENT
5.1 GROUND WATER
The five-year review documents the effectiveness of the remedy to protect human health and the
environment. The document indicates that ground water contamination is being captured to some extent
by the extraction system (as indicated by the decreasing concentrations in MW-18) but that the extent of
capture is unclear. Some limited contamination may or may not continue to migrate past the extraction
trench toward the wetlands, but this migration is sufficiently limited such that concentrations have been
decreasing. Therefore, the P&T system has had a positive effect in reducing contaminant migration.
Contaminant concentrations in the intermediate and deep intervals screened by the monitoring network
have consistently been below the 1 ug/L standard and have generally been undetectable, except for one
recent detection of 2 ug/L in IW-6. Limited impacts (e.g., below 1 ug/L) have been detected in DW-2,
IW-6, and DW-6, all of which are located in source areas. These limited impacts in the source areas
suggest the potential for downward contaminant migration, but might also indicate contamination that
was "pulled" down during well installation.
The contamination in the shallow aquifer does not pose a current threat to human health because there are
no buildings on the property other than the treatment plant and the water in the shallow aquifer is
generally unsuitable for drinking, regardless of VOC contamination.
5.2 SURFACE WATER
Historical concentrations in MW-18 indicate that TCE is present downgradient of the extraction trench
and may be discharging to the wetlands. No water quality sampling of the wetlands has been conducted
to determine impacts to the wetlands, but such sampling was recommended during the Five-Year Review
that was completed in September 2005.
5.3 AIR
There are no buildings on or adjacent to the property that would be adversely affected by vapor intrusion.
The Five-Year Review indicates that due to the elevated TCE concentrations (e.g., over 1,000 ug/L) and
the shallow depth to ground water that any development that would occur on the property should be
limited in area and restricted in use to avoid the risks associated with vapor intrusion.
5.4 SOIL
The soil aspects of the remedy, primarily consisting of excavation, have been implemented, but it is
possible unsaturated soil (in addition to saturated soil) remains impacted and a continuing source of
contamination. The RSE team did not review post-excavation samples. Surface soils, however, have
been remediated, therefore risks due to direct contact with impacted soil or from migration of impacted
dust from the site are not indicated.
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5.5 WETLANDS AND SEDIMENTS
Please refer to the discussion under Section 5.3 (Surface Water) for comments regarding potential impacts
to the wetlands.
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6.0 RECOMMENDATIONS
Cost estimates provided herein have levels of certainty comparable to those done for CERCLA Feasibility
Studies (-30%/+50%), and these cost estimates have been prepared in a manner consistent with EPA 540-
R-00-002, A Guide to Developing and Documenting Cost Estimates During the Feasibility Study, July,
2000.
6.1 RECOMMENDATIONS TO IMPROVE EFFECTIVENESS
6.1.1 IMPROVE CAPTURE ZONE EVALUATION WITH INSTALLATION OF PIEZOMETER
PAIRS
Determining the necessary flow rate from the extraction trench to maintain adequate capture is a difficult
task given the subsurface heterogeneity, the impact of the sand channel, and the variable rate of ground
water flow through the area. As discussed in Section 4.0 of this report, the decreasing concentration
trends at MW-18 suggest that capture is occurring, but it is uncertain if capture is complete such that
concentrations downgradient of the extraction trench will decrease to background levels over time.
Rather than wait several years to form a conclusion based on the concentration trends, the RSE team
suggests installing piezometer pairs (with the pair oriented perpendicular to the trench) at certain intervals
along the length of the trench on the downgradient side as illustrated in the figure below. In each pair,
one piezometer might be approximately 1 to 3 feet from the trench and the other might be 10 feet further
from the trench. The piezometer pairs would likely be installed to a depth of approximately 15 feet below
ground surface with a 5-foot screened interval. The figure illustrates four sets of piezometer pairs, which
is appropriate for this site. At least one piezometer pair should be placed in the area of the sand channel.
If the extraction rate is sufficient to provide capture, then the piezometer pairs should indicate flow
toward the trench. If the extraction rate is not sufficient then, in some portions along the trench, water
will continue to migrate through the trench and the hydraulic gradient will be directed to the east (e.g.,
regionally downgradient). The water levels in these peizometers can be evaluated seasonally to determine
at what periods capture is sufficient. If possible, the site team should consider a step extraction test with
the trench to determine how much more extraction might be necessary to find an extraction rate that
balances plume capture and maintaining the water level in the wetlands.
downgradient
piezometer
J Hydraulic gradient under
pumping conditions
TRENCH
If possible, the site team should use MW-10 and MW-11 as components of these piezometer pairs to
reduce the number of points that need to be installed. The RSE team estimates that this effort might
require up to $20,000 in upfront costs to implement. For additional costs, piezometers could also be
installed further downgradient of the trench to evaluate potential drawdown in the wetlands. The site
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team will need to evaluate the value of the piezometers closer to the wetlands given that monitoring wells
are already present in the wetlands. The effect on long term costs of this approach should be negligible
since the water levels in these piezometers could be easily added to a routine well gauging event and data
analysis is comprised of only evaluating the direction of flow for each of these piezometer pairs.
6.1.2 BASED ON CAPTURE ZONE EVALUATION, CONSIDER MODIFICATION OF
TREATMENT PLANT AND INJECTION TRENCH TO INCREASE HYDRAULIC
CAPACITY
In net, the P&T system is extracting and treating approximately 3.5 gpm, but because of extensive water
recycling within the treatment plant, the treatment plant is treating approximately 7 gpm and is operating
at or near capacity (even though it was designed for a maximum capacity of 15 gpm). The capture zone
analysis above may indicate that additional extraction is necessary to provide adequate capture without
adversely affecting the water level in the wetlands. If this is the case the site team will want to modify the
treatment plant to accommodate additional flow. The site team will want a good understanding of the
amount of flow it will need to treat, so a step test with the extraction trench and the above-noted
piezometer pairs would be advisable to determine the optimal flow rate. Based on its review of the
system and discussions with the plant operator, the RSE team sees the following options for modifying
the overall system capacity if an increase in capacity is needed.
Option 1: An Increase in Flow Rate of 2 gpm or Less is Needed - For this minimal increase in flow, it
may be sufficient to set sludge wasting from the clarifier to a timer (rather than continuous wasting) so
that less water is recycled from the clarifier to the head of the plant. With the increased flow and solids
loading to the filters, the site team might also want to install additional bag filters in parallel to reduce the
frequency with which filter changeouts are required. The infiltration trench may also need to be
augmented. The site team might consider adding to the existing infiltration trench or adding an additional
trench to the north or east side of the treatment plant. With the increased flow rate, the tray aerator will
likely provide enough removal to meet discharge standards, but the site team may want to aim for
additional removal to avoid reinjecting concentrations that are above the cleanup standards. This could be
achieved by improving maintenance/cleaning of the tray aerator to increase performance or adding
another tray. In very unusual circumstances, the site team might need to install the spare tray aerator (in
series with the current tray aerator) or a liquid phase GAC polishing step. If the spare tray aerator is
installed in series with the existing tray aerator, the VOC offgas from the lag tray aerator would be
undetectable and would not require vapor treatment. This option might require $20,000 to $100,000 in
upfront costs to implement, but additional annual costs would not change significantly. The above range
depends on what items are implemented. Adding another infiltration trench would be one of the more
costly items (approximately $40,000).
Option 2: An Increase in Flow Rate of Greater than 2 gpm is Needed - The site team should consider the
same modifications above, but they should also consider installing a larger clarifier to accommodate
additional flow. The need for additional injection capacity, VOC treatment, and bag filters would be
higher than that for Option 1. In addition, given the higher extraction rate, there may be a greater
likelihood of dewatering the wetlands. If this stress on the wetlands is observed, the site team should
consider discharging some or all of the treated water to the wetlands. Discharging water directly to the
wetlands (i.e., downgradient of the extraction trench) should effectively reduce the amount of "clean"
water that needs to be extracted. Furthermore, because the treated water is discharged downgradient of
the extraction trench, it minimizes the potential for reducing the water level in the wetlands. Changing
the discharge location, however, has disadvantages. Extending a discharge line this far (over 1,000 feet)
would be fairly costly, and changing the discharge location to surface water would likely be accompanied
by a change in discharge criteria. The second air stripper available at the treatment plant would likely
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need to be added in series. This option might require $50,000 to $150,000 in upfront costs to implement,
but additional annual costs would not change significantly. The above range depends on what items are
implemented. The primary cost differences between Options 1 and 2 are the purchase and installation of
a clarifier and the potential for extending a discharge line over 1,000 feet to the wetlands.
6.1.3 IMPROVE SITE CHARACTERIZATION WITH INSTALLATION OF Two MONITORING
WELLS
The RSE team believes there are two additional points for long-term monitoring that could help long-term
plume delineation and evaluation of remedial progress. The RSE team believes one monitoring well
should be installed at a location triangulated between MW-5, MW-6, and MW-12 (e.g., near CPT-13 and
CPT-14) to improve understanding of contamination in the sand channel upgradient of the trench. This
well could be installed to the bottom of the sand channel so that the water sampled from the well accounts
for contamination that might be present along the bottom of the channel. The RSE team does not see the
need for additional investigation along the bottom of the sand channel at this point. Given that this new
well would be installed along the bottom of the sand channel, the RSE team also does not see the need for
re-installing MW-2 or MW-5 to the bottom of the sand channel. The other monitoring well that the RSE
team recommends installing is triangulated between MW-6, MW-7, and MW-3. This new well would
help delineate the southern boundary of the plume over the life of the remedy. Installation of these wells
might cost $10,000 if the effort can be coordinated with other field activities (e.g., the piezometer
installation noted in Section 6.1.1.) There will be additional costs on an annual basis to include these two
new wells in the sampling program. Given that ground water sampling is conducted annually, that
increase in costs might be $1,500 per year for both sampling and analysis.
6.1.4 CONDUCT LIMITED SAMPLING OF THE WETLANDS SURFACE WATER AND
SEDIMENTS AS INDICATED IN THE FIVE-YEAR REVIEW
The Five-Year Review recommends limited sampling of the wetlands surface water and sediments to
determine compliance with New Jersey guidance/standards and to confirm that the remedy is protective of
ecological receptors. Recent wetlands evaluations have indicated vigorous/healthy vegetation growth and
colonization of plant species native to the area. Some wildlife browsing has also been noted. The site
team may benefit from a consultation from EPA Region 2 Biological Technical Assistance Group
(BTAG) regarding the health of the wetlands. It may be appropriate to limit the scope of the wetlands
sampling because, depending on the health of the wetlands, remedial action may be more damaging than
the impacts of contaminants. The most appropriate measures would likely be to improve the capture
offered by the P&T system, which the site team will already be evaluating and improving due to impacts
seen in MW-18. The wetlands sampling, from perhaps 3 to 5 locations could be added to the upcoming
2006 ground water monitoring event. This might cost approximately $3,000 for labor, equipment, and
analysis.
6.1.5 CONFIRM THAT GROUND WATER MONITORING NETWORK PROVIDES ENOUGH
INFORMATION TO EVALUATE CAPTURE
The site team recently optimized the ground water monitoring network using the MAROS software. The
sampling was reduced from 30 monitoring wells sampled on a quarterly basis to 12 monitoring wells
sampled on an annual basis. The site team did not report which 12 wells would continue to be sampled.
The RSE team agrees with reducing the sampling frequency to annual sampling and the RSE team agrees
with reducing the number of sampling locations. However, the RSE team encourages the site team to
revisit their analysis and confirm that they will have enough sampling to help confirm plume capture. In
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addition to sampling the two new wells recommended in Section 6.1.3, the RSE team sees the value in
sampling the following wells on an annual basis with respect to monitoring plume containment.
Shallow Wells: MW-3, MW-4, MW-9, MW-10, MW-11, MW-18, MW-19, MW-21
Intermediate or Deep Wells: DW-2, IW-4, IW-5, IW-6, DW-7, IW-11
MW-2 and MW-6 are not included in the above list because they are source area wells. The
concentration trends will not likely decrease in the absence of source area remediation, and the trends in
these wells would not be meaningful for evaluating capture. Rather, emphasis has been placed on
monitoring those wells that either outline the plume or are located in areas that are expected to clean up if
capture is adequate. It would be beneficial to sample MW-2 and MW-6 on a less frequent basis (perhaps
in coordination with a Five-Year Review) to track the concentrations. Alternatively, it may be beneficial
to continue sampling these two wells on an annual basis if source area remediation is implemented and
the site team wishes to evaluate effectiveness of those measures.
The importance of sampling the above-mentioned wells depends on the remedy objectives regarding
plume capture and other lines of evidence that support capture is adequate. Sampling the above-noted
wells would likely cost 50% more per year than sampling the 12 wells selected by the site team. This
might translate to a difference of $5,000 more per year in sampling costs.
6.2 RECOMMENDATIONS TO REDUCE COSTS
6.2.1 REVISE PROCESS MONITORING PROGRAM
The RSE team estimates that process monitoring accounts for approximately $15,000 of the annual O&M
costs. Now that the treatment plant has been operating for over five years with relatively consistent
influent data and plant operation has stabilized, the site team should consider reducing the monitoring
frequency from monthly at MH-1 and the equalization tank to quarterly. This would save approximately
$5,000 per year.
6.2.2 CONSIDER NOT IMPLEMENTING ASPECTS OF THE PROPOSED WORK PLAN
As part of the RSE effort, the RSE team reviewed a draft pre-design investigation work plan that was
provided to the site team by another contractor (i.e., not the RSE team or the site contractor). The work
plan included several items that the RSE team believes would not be worth the cost of conducting. The
following items that the RSE team advises against implementing are discussed below. The RSE team was
not provided with estimated costs for implementing these aspects of the work plan. As a result, the
estimated cost savings shown are estimated by the RSE team.
Consider not implementing the following items from the proposed work plan:
Ground water assessment - The work plan suggests conducting a ground water assessment that
includes measurement of water levels during pumping and non-pumping conditions, plus
sampling of approximately 15 wells for VOCs, iron, and natural attenuation parameters. Water
levels have been collected several times from site monitoring wells, and it is clear that the density
of monitoring wells is not sufficient to generate potentiometric surface maps that will be useful
for a capture zone evaluation. Therefore, the RSE team sees little value in moving forward with
the proposed additional water level measurements. Several rounds of VOC sampling have
occurred, so the RSE team does not see the need for any additional sampling events beyond the
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routinely scheduled annual sampling. It is known that the aquifer is high in iron based on influent
to the treatment plant; therefore, sampling from the monitoring wells will provide little or no
additional benefit. Historical analytical data shows that dichloroethene concentrations (all
isomers) are undetectable or very low (e.g., less than 5 ug/L) relative to TCE concentrations (well
over 1,000 ug/L). This indicates that there is little natural potential for monitored natural
attenuation given the current conditions. Given this strong evidence for limited natural
attenuation and the remaining source areas, the evaluation of natural attenuation appears
premature. The RSE team does not recommend moving forward with this ground water
assessment. The RSE team estimates that this will save approximately $15,000 of field work and
analysis.
Source Area Delineation - The work plan suggests a broad grid of membrane interface probe
(MIP) sampling (with approximately 20 locations) to identify source areas at the site and to
search for DNAPL. Delineation has already narrowed the plume to an approximate 1.25-acre
area, and the RSE team understands that several direct-push sampling events have been
conducted in the past to evaluate source areas. As a result, the RSE team recommends revisiting
some of this past data and then focusing any remaining investigation around known source areas
such as those around MW-2, MW-6, PW-1, and PW-2 rather than pursuing the proposed source
area delineation in the work plan. Some of the reason for the proposed source area delineation is
the possible presence of DNAPL. The RSE team believes that such an evaluation will indicate
potentially high areas of contamination but will not conclusively determine if there is no DNAPL,
residual DNAPL, or free-phase DNAPL. Furthermore, whether DNAPL is identified as present
or not, the more important issue is the performance of various remedial activities at the site.
Therefore, rather than pursuing a DNAPL investigation in this very tight formation, the RSE team
is more in favor of identifying source areas (possibly from existing data) and then piloting
appropriate remedial technologies and carefully evaluating their effectiveness. With respect to the
geotechnical samples proposed in the work plan, the RSE team notes that several cone
penetrometer tests have been conducted at the site, providing sufficient information about the soil
properties. Assuming four days in the field at $7,500 per day, avoiding this item would save
approximately $30,000 of field work.
Aquifer Tests - The work plan proposes 120 hours (i.e., 72 hours of pumping and 48 hours of
recovery) of aquifer tests at two or more wells. These tests include the replacement of MW-2 and
MW-5, the installation of seven other monitoring wells, and the potential for additional well
installation for pumping and observation purposes. The RSE team does not see the value of
conducting pump tests or installing the additional wells. The RSE team has proposed installing
two additional wells, and one of these wells serves multiple purposes, including providing
information about ground water quality at the bottom of the sand channel. With this RSE-
recommended well, the re-installation of MW-2 and MW-5 (which would be done to increase the
depth of the two wells by approximately 1.5 to 2 feet each) would be redundant. Furthermore, the
RSE team believes that the performance of the P&T system to date demonstrates that the system
can be effective for providing capture but will not provide timely restoration of the aquifer.
Recovery from the two extraction wells, which were installed with 22-inch borings, has been very
low (less than 1 gpm each) suggesting that the formation is tight and that any remediation strategy
will require a dense network of points to either extract contamination or inject reagents. The RSE
team believes that an estimate of hydraulic conductivity and storativity will not provide
information that is more beneficial than the information the site team already possesses.
Assuming three days in the field for drilling at approximately $5,000 per day and seven days in
the field for pump testing and sampling at $2,500 per day, avoiding this item would likely save
over $30,000 in field work.
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6.3 RECOMMENDATIONS FOR TECHNICAL IMPROVEMENT
6.3.1 INSTALL TIMER FOR WASTING SLUDGE FROM CLARIFIER
As part of Section 6.1.2, the RSE team recommends installing a timer for wasting sludge from the
clarifier. The plant operator has been contemplating making this change, and the RSE team is in favor of
this change being made even if increasing treatment plant capacity is not needed. This is a relatively low
cost item and should be feasible for under $2,000.
6.4 CONSIDERATIONS FOR GAINING SITE CLOSE OUT
6.4.1 PILOT IN-SITU CHEMICAL OXIDATION WITH PERMANGANATE FOR AGGRESSIVE
SOURCE REMOVAL
The RSE team notes that the P&T system (perhaps with a few modifications to increase capacity) has the
ability to contain the plume in the horizontal direction. However, the system will not likely succeed at
providing cleanup in a reasonable time frame or guaranteeing containment in the vertical direction. Given
the relatively limited source areas, a reduction in the time to cleanup, and the additional protectiveness of
removing contamination so that it will not migrate vertically, the RSE supports the evaluation and
piloting of aggressive source area remediation at this site. The RSE team suggests first considering in-
situ chemical oxidation with permanganate for the following reasons:
In-situ chemical oxidation can easily and cost-effectively be delivered by a shallow trench or by
several small injection points. Based on recent discussions with chemical oxidation vendors for
work in the New Jersey and New York area, the RSE team estimates that large scale chemical
oxidation at this site might cost approximately $1,100 per 100 square feet assuming an injection
radius of influence of approximately 7.5 feet, injection at two depth intervals, and use of
permanganate. Assuming the entire 1.25 acres of impacted area as delineated by the current
monitoring network would be treated, this translates to a cost of approximately $1,200,000
(excluding performance/confirmation sampling) if two rounds of injections are conducted. Given
that this is equal to approximately four to five years of P&T operation, it appears worthwhile to
pilot this technology, especially if the area to be treated can be reduced by improved hot spot
delineation.
In-situ chemical oxidation performance depends on total oxidant demand, which can easily be
tested at the bench scale, but its performance is not heavily dependent on other subsurface
parameters or biological activity (in particular permanganate is effective over a wide pH range).
Permanganate is suitable for oxidizing TCE, PCE, and breakdown products of these two
compounds.
Permanganate is stable relative to other oxidants, improving its ability to persist in ground water
and improving the coverage of each injection point.
Permanganate is inexpensive relative to other oxidants and other reagents that might be used for
other remedial technologies, such as zero-valent iron.
22
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Chemical oxidation works relatively quickly, allowing the site team to quickly evaluate the
success of the pilot test and the need for subsequent injections.
Chemical oxidation is appropriate at the high concentrations seen at this site.
The RSE team recommends pursuing this path in a phased approach as follows:
Evaluate past data from monitoring wells and direct-push events to best determine source areas.
Based on consideration of past data, conduct a limited investigation in the vicinity of MW-2 to
isolate an approximate 4,000 square-foot area to pilot remediation technologies. The ideal area
would address concentrations that are above 1,000 ug/L, would not be downgradient of TCE
contamination that could re-contaminate the pilot area, and would include MW-2. Include vadose
zone soils in the sampling to determine if vadose zone soil also requires treatment. Install two
additional monitoring points within the pilot area (in addition to MW-2) that can be used to
evaluate the success of remediation. Obtain baseline samples from these monitoring points plus
IW-2 and DW-2. The TRIAD method (www.triadcentral.org) of dynamic work planning may be
appropriate for this work.
Have a chemical oxidation vendor conduct the proper bench scale testing (including total oxidant
demand) for permanganate using site water and soil. (Note that the total oxidant demand may be
relatively high due to the high concentrations of reduced iron in ground water.)
Assuming the bench testing is successful, obtain bids from at least two chemical oxidation
vendors to treat the pilot area with one round of injections.
At two months, four months, and six months after the injection, sample ground water from within
the pilot area (three sampling locations including MW-2, plus IW-2 and DW-2) to determine
contaminant reductions, potential rebound, and potential contaminant migration toward IW-2
and/or DW-2. If contaminant concentrations show at least a 75% reduction after six months with
no significant downward migration, consider a second injection and repeat pilot area monitoring.
If contaminant concentrations show a greater than 90% decrease relative to initial sampling results,
consider applications in other areas.
The RSE team estimates that TRIAD-based investigation might take two days on site and might cost
approximately $20,000 for field work, plus an additional $10,000 for work plans, health and safety plans,
and final reporting. The RSE team further estimates that the bench scale in-situ oxidation tests and pilot
test might cost $130,000, including the sampling conducted after each round of injections and final
reporting. This is a significantly higher unit cost than the estimated full-scale application, due to
inclusion of sampling/reporting and economies of scale.
6.5 CONSIDERATIONS FOR GAINING SITE CLOSE OUT
The RSE team suggests moving forward concurrently with 6.1.1, 6.1.3, and 6.1.4 as a comprehensive
field event. Recommendation 6.2.2 would be effectively implemented if the above recommendations are
implemented in place of the proposed work plan. After this work is completed, the site team could move
forward with 6.4.1 to determine the effectiveness of aggressive source remediation. Recommendations
OO
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6.2.1 and 6.3.1 can be implemented as soon as possible, and Recommendation 6.1.5 can be implemented
along with the next regularly scheduled ground water sampling event. Recommendation 6.1.2 may
require substantial capital costs and is contingent on the results from Recommendations 6.1.1 and 6.4.1.
Therefore, it should be implemented after the other recommendations are implemented and the associated
data has been evaluated.
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7.0 SUMMARY
The observations and recommendations contained in this report are not intended to imply a deficiency in
the work of either the system designers or operators, but are offered as constructive suggestions in the
best interest of the EPA and the public. These recommendations have the benefit of being formulated
based upon operational data unavailable to the original designers.
Recommendations are provided in all four categories: effectiveness, cost reduction, technical
improvement, and site closeout. The effectiveness recommendations focus on methods of improving the
evaluation of capture, cost-effective ideas from increasing the treatment plant hydraulic capacity (if
needed), improved delineation through addition of monitoring wells, and limited sampling of the
wetlands. The recommendations for cost reduction focus on further optimizing the ground water and
process water monitoring programs as well as not implementing selected items from a recently proposed
work plan from another contractor. The recommendation for technical improvement involves optimizing
the sludge processing from the clarifier, and the recommendation for site closure involves a pilot test of
aggressive hot spot remediation using in-situ chemical oxidation.
Table 7-1 summarizes the costs and cost savings associated with each recommendation. Both capital and
annual costs are presented. Also presented is the expected change in life-cycle costs over a 10-year
period for each recommendation both with discounting (i.e., net present value) and without it.
25
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Table 7-1. Cost Summary Table
Recommendation
6.1.1 Improve capture
zone evaluation with
installation of piezometer
pairs
6.1.2 Based on capture
zone evaluation, consider
modification of treatment
plant and injection trench
to increase hydraulic
capacity
6.1.3 Improve site
characterization with
installation of two
monitoring wells
6.1.4 Conduct limited
sampling of the wetlands
surface water and
sediments as indicated in
the five-year review
6.1.5 Confirm that
Ground Water Monitoring
Network Provides Enough
Information to Evaluate
Capture
6.2.1 Revise process
monitoring program
6.2.2 Consider not
implementing aspects of
the proposed work plan
6.3.1 Install timer for
wasting sludge from
clarifier
6.4.1 Pilot in-situ
chemical oxidation with
permanganate for
aggressive source removal
Reason
Effectiveness
Effectiveness
Effectiveness
Effectiveness
Effectiveness
Cost
Reduction
Reduction
Technical
Improvement
Site Closure
Additional
Capital
Costs ($)
$20,000
$20,000
to
$150,000
$10,000
$3,000
$0
$0
($75,000)
$2,000
$160,000
Estimated
Change in
Annual
Costs ($/yr)
$0
$0
$1,500
$0
$5,000
($5,000)
$0
$0
$0
Estimated
Change in
Life-cycle
Costs ($)*
$20,000
$20,000
to
$150,000
$55,000
$3,000
$150,000
($150,000)
($75,000)
$2,000
$160,000
Estimated
Change in Life-
cycle Costs
($)**
$20,000
$20,000
to
$150,000
$34,000
$3,000
$81,000
($81,000)
($75,000)
$2,000
$160,000
Costs in parentheses imply cost reductions
* assumes 30 years of operation with a discount rate of 0% (i.e., no discounting)
** assumes 30 years of operation with a discount rate of 5% and no discounting in the first year
26
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FIGURES
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W-13
W-13
dW-13
-WELLS
LOCATED
220 FT. TO
THE WEST
Figure 1-1 Site map
23
1-19
WELL LOCATED
150 FT. TO
THE NORTH
^-WETLANDS .
Scale In feet
aMH-1
OUTLINE OF WHERE
SAND CHANNEL
THICKNESS
EXCEEDS 4 FT.
M4
EXTRACTION TRENCH
EXPLANATION
MH-1O EXTRACTION TRENCH MANHOLE
PW-l-$- EXTRACTION WELL
MW-8-0- MONITORING WELL
RE-INJECTION TRENCH
Note: Information obtained from design report by Acres, 1998
with a compilation of historical data from monitoring wells and
direct push sampling events.
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-13
-13
W-13
-WELLS
LOCATED
220 FT. TO
THE WEST
Figure 1-2 Extent of VOC contamination
23
'-19
'-18
WELL LOCATED
150 FT. TO
THE NORTH
^WETLANDS
Scale In feet
lMH-1
'-15
OUTLINE OF WHERE
SAND CHANNEL
THICKNESS
EXCEEDS 4 FT.
'-14
EXTRACTION TRENCH
EXPLANATION
MH-1O EXTRACTION TRENCH MANHOLE
PW-l-$- EXTRACTION WELL
MW-8-0- MONITORING WELL
2005 EXTENT OF VOC
CONTAMINATION (PRIMARILY TCE)
ABOVE SITE CLEANUP STANDARD
OF 1 ug/L
Note: Maximum TCE concentrations in 2005 are at MW-2
(>10,000 ug/L) and at MW-6 (>5,000 ug/L)
RE-INJECTION TRENCH
Note: Information obtained from design report by Acres, 1998
with a compilation of historical data from monitoring wells and
direct push sampling events.
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