REMEDIATION SYSTEM EVALUATION
FORMER HONEYWELL FACILITY
FORT WASHINGTON, PENNSYLVANIA
Report of the Remediation System Evaluation,
Site Visit Conducted at the Former Honeywell Facility, Fort Washington, Pennsylvania
January 30, 2003
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Office of Solid Waste EPA 542-F-04-025
and Emergency Response July 2003
(5102G) www.epa.gov/tio
clu-in.org/optimization
Remediation System Evaluation
Former Honeywell Facility
Fort Washington, Pennsylvania
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NOTICE AND DISCLAIMER
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 S&K Technologies Prime Contract No. GS06T02BND0723. Mention of trade names or
commercial products does not constitute endorsement or recommendation for use.
This report has undergone review by the EPA site managers and EPA headquarters staff. For more
infomation about this project, contact: Mike Fitzpatrick (703-308-8411 or fitzpatrick.mike@epa.gov) or
Kathy Yager (617-918-8362 or yager.kathleen@epa.gov).
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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,
effectiveness in protecting human health and the environment, 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, including estimates of resulting
net cost impacts, are provided in the following four categories:
improvements in remedy effectiveness in protecting human health and the environment
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, might 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 Honeywell facility is located at 1100 Virginia Drive in Upper Dublin Township, Montgomery
County, Pennsylvania in the Fort Washington Industrial Park. The property is approximately 67 acres
and is owned by 1100 Virginia Drive Associates. The main building is 861,000 square feet. The facility
was built in 1964 and was primarily used for the manufacturing of electronic controls and mechanical
valve assemblies. In 1986, Honeywell sold the property but continues to lease office space. A portion of
the main building (approximately 103,000 square feet) is also used by the DeVry University. Soil
sampling related to a tank excavation in 1986 provided the first documented presence of subsurface
contamination. Further investigations revealed ground water concentrations of trichloroethene (TCE)
exceeding 10,000 ug/L. A pump and treat (P&T) system operates at the facility as a final remedy, which
is the focus of this RSE.
The RSE team observed an extremely well-managed remedy. Honeywell, their contractors, and EPA all
have an excellent understanding of the site conditions, the remedy, and potential risks. Continuing efforts
have been made by the site team as a whole to improve system operation and protect human health and
the environment. 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, the public, and the facility. These recommendations have the
obvious 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 recommendations to improve effectiveness include the following:
Further evaluate the potential for vapor intrusion into the main building occupied by DeVry
University.
Consider the installation of two monitoring wells to assist in the evaluation of plume capture.
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Modify the interpretation of plume capture by correcting the water levels in the extraction wells
for well losses and adding three existing offsite wells to the sampling program.
Consider institutional controls.
Recommendations for cost reduction include the following:
Consider replacing the currently used UVOX system with an air stripper and off-gas treatment
with vapor phase granular activated carbon (GAC). If implemented, this recommendation might
require up to $100,000 in capital costs but might save $27,500 per year in annual O&M costs.
Implementing this recommendation is contingent upon decisions made regarding implementation
of the site-closeout recommendations.
Consider revising the ground water monitoring program by reducing the sampling frequency at
select wells. The sampling and analysis frequency is discussed and a potential revised
monitoring program is provided. If implemented, this recommendation should not require any
capital costs and might save $16,000 per year in annual sampling and analysis costs.
The remaining recommendations pertain to technical improvement and site closeout. Notable
recommendations include considering alternative remedial approaches to address persistently elevated
contaminant concentrations in a localized area and modifying the remedy based on the results from
implementing those approaches.
A table summarizing the recommendations, including estimated costs and/or savings associated with
those recommendations, is presented in Section 7.0 of this report.
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PREFACE
This report was prepared as part of a pilot project conducted by the United States Environmental
Protection Agency (USEPA) Office of Solid Waste (OSW) and Technology Innovation Office (TIO).
The objective of this project is to conduct Remediation System Evaluations (RSEs) of pump and treat
systems under the Resource Conservation and Recovery Act. The following organizations are
implementing this project.
Organization
Key Contact
Contact Information
USEPA Office of Solid Waste
(OSW)
Mike Fitzpatrick
5303W
USEPA Headquarters
Ariel Rios Building 1200
Pennsylvania Avenue, N. W.
Washington, DC 20460
phone: 703-308-8411
fitzpatrick.mike@epa.gov
USEPA Technology Innovation
Office
(USEPA TIO)
Kathy Yager
11 Technology Drive (ECA/OEME)
North Chelmsford, MA 01863
phone: 617-918-8362
fax: 617-918-8427
yager.kathleen@epa.gov
GeoTrans, Inc.
(Contractor to USEPA)
Doug Sutton
GeoTrans, Inc.
2 Paragon Way
Freehold, NJ 07728
(732) 409-0344
Fax: (732) 409-3020
dsutton@geotransinc.com
in
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TABLE OF CONTENTS
EXECUTIVE SUMMARY i
PREFACE iii
TABLE OF CONTENTS iv
1.0 INTRODUCTION 1
.1 PURPOSE 1
.2 TEAM COMPOSITION 2
.3 DOCUMENTS REVIEWED 2
.4 PERSONS CONTACTED 3
.5 SITE LOCATION, HISTORY, AND CHARACTERISTICS 3
1.5.1 LOCATION 3
1.5.2 POTENTIAL SOURCES 5
1.5.3 HYDROGEOLOGIC SETTING 6
1.5.4 POTENTIAL RECEPTORS 6
1.5.5 DESCRIPTION OF GROUND WATERPLUME 7
2.0 SYSTEM DESCRIPTION 8
2.1 SYSTEM OVERVIEW 8
2.2 EXTRACTION SYSTEM 8
2.3 TREATMENT SYSTEM 8
2.4 MONITORING PROGRAM 9
3.0 SYSTEM OBJECTIVES, PERFORMANCE AND CLOSURE CRITERIA 11
3.1 CURRENT SYSTEM OBJECTIVES AND CLOSURE CRITERIA 11
3.2 TREATMENT PLANT OPERATION STANDARDS 11
4.0 FINDINGS AND OBSERVATIONS FROM THE RSE SITE VISIT 12
4.1 FINDINGS 12
4.2 SUBSURFACE PERFORMANCE AND RESPONSE 12
4.2.1 WATER LEVELS 12
4.2.2 CAPTURE ZONES 12
4.2.3 CONTAMINANT LEVELS 15
4.3 COMPONENT PERFORMANCE 15
4.3.1 EXTRACTION SYSTEM WELLS AND PUMPS 15
4.3.2 FILTERS 16
4.3.3 UVOX SYSTEM 16
4.3.4 GAC 16
4.4 COMPONENTS OR PROCESSES THAT ACCOUNT FOR MAJORITY OF MONTHLY COSTS 16
4.4.1 UTILITIES 17
4.4.2 NON-UTILITY CONSUMABLES 17
4.4.3 LABOR 17
4.4.4 CHEMICAL ANALYSIS 17
4.5 RECURRING PROBLEMS OR ISSUES 17
4.6 REGULATORY COMPLIANCE 18
4.7 TREATMENT PROCESS EXCURSIONS AND UPSETS, ACCIDENTAL CONTAMINANT/REAGENT RELEASES .... 18
4.8 SAFETY RECORD 18
iv
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5.0 EFFECTIVENESS OF THE SYSTEM TO PROTECT HUMAN HEALTH AND THE ENVIRONMENT . 19
5.1 GROUND WATER 19
5.2 SURFACE WATER 20
5.3 AIR 20
5.4 SOILS 21
5.5 WETLANDS AND SEDIMENTS 21
6.0 RECOMMENDATIONS 22
6.1 RECOMMENDATIONS TO IMPROVE EFFECTIVENESS 22
6.1.1 FURTHER EVALUATE POTENTIAL FOR VAPOR INTRUSION 22
6.1.2 CONSIDER THE INSTALLATION OF Two MONITORING 23
6.1.3 MODIFY APPROACH TO EVALUATING PLUME CAPTURE 24
6.1.4 CONSIDER INSTITUTIONAL CONTROLS 25
6.2 RECOMMENDATIONS TO REDUCE COSTS 25
6.2.1 CONSIDER REPLACING UVOX SYSTEM WITH AIR STRIPPER AND VAPOR PHASE GAC 25
6.2.2 CONSIDER REVISIONS TO GROUND WATER MONITORING PROGRAM 27
6.3 MODIFICATIONS INTENDED FOR TECHNICAL IMPROVEMENT 28
6.3.1 USE HDPE FOR RW-3 DROP TUBE IF/WHEN IT REQUIRES REPLACEMENT 28
6.4 CONSIDERATIONS FOR GAINING SITE CLOSE OUT 28
6.4.1 CONSIDER ALTERNATIVE REMEDIAL APPROACHES TO AUGMENT P&T SYSTEM 28
6.4.2 CONSIDER MODIFYING THE REMEDY 32
7.0 SUMMARY 33
List of Tables
Table 7-1. Cost summary table
List of Figures
Figure 1-1. Honeywell Facility, Surrounding Area, and Location of the Cross-Section Depicted in Figure 1-2
Figure 1-2. Northwest/Southeast Geologic Cross-Section as Depicted in Figure 1-1
Figure 1-3. Extent of VOC Contamination Based on the July 2002 Sampling Event
Figure 4-1. Potentiometric surface map depicting pre-pumping conditions (1993)
Figure 4-2. Potentiometric surface map depicting pumping conditions (October 2002)
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1.0 INTRODUCTION
1.1 PURPOSE
During fiscal years 2000, 2001, and 2002 Remediation System Evaluations (RSEs) were conducted at 24
Fund-lead pump and treat (P&T) sites (i.e., those sites with pump and treat systems funded and managed
by Superfund and the States). Due to the opportunities for system optimization that arose from those
RSEs, EPA TIO and OSW are performing a pilot study of conducting RSEs at RCRA sites. During fiscal
year 2003, RSEs at up to 5 RCRA sites are planned in an effort to evaluate the effectiveness of this
optimization tool for this class of sites. GeoTrans, Inc., an EPA contractor, is conducting these
evaluations, and representatives from EPA OSW and TIO are attending the RSEs 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.armv.mil/library/guide/rsechk/rsechk.html
A 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, effectiveness in protecting human
health and the environment, and site exit strategy. The evaluation includes reviewing site documents,
visiting the site for 1 to 1.5 days, and compiling a report that includes recommendations to improve the
system. Recommendations with cost and cost savings estimates are provided in the following four
categories:
improvements in remedy effectiveness in protecting human health and the environment
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, might 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 Honeywell Fort Washington facility was selected by EPA OSW based on progress made toward
Environmental Indicators and comments from the EPA project manager for the site . 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.
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1.2
TEAM COMPOSITION
The team conducting the RSE consisted of the following individuals:
Rob Greenwald, 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 Bob Maxey from EPA OSW, who served as an observer of the
RSE process.
1.3
DOCUMENTS REVIEWED
Author
EEC Environmental, Inc.
Harding Lawson Assoc.
Harding Lawson Assoc.
Harding Lawson Assoc.
US EPA
US EPA
US EPA
Harding Lawson Assoc.
Harding Lawson Assoc.
Harding Lawson Assoc.
Harding Lawson Assoc.
Harding Lawson Assoc.
Harding Lawson Assoc.
Harding Lawson Assoc.
US EPA
US EPA
Date
2/1992
12/15/1993
7/14/1994
8/4/1994
8/24/1994
12/16/1994
8/18/1995
11/9/1995
2/13/1996
5/21/1996
8/12/1996
11/8/1996
5/21/1996
5/21/1996
6/19/1996
1/23/1997
Title
Interim Measures Design
Draft Results of the RCRA Facility Investigation
Results of Bedrock Investigation
Draft Results of Risk Assessment Activities
Statement of Basis
Final Decision and Response to Comments
Final Administrative Order on Consent
Draft Results of Aquifer Performance Test and
UV/Peroxide Oxidation Treatability Study
Quarterly Progress Report November 1995 through
January 1996
Quarterly Progress Report February through April
1996
Quarterly Progress Report May through July 1996
Quarterly Progress Report August through October
1996
Groundwater Extraction and Treatment System
Results of Groundwater Flow Modeling
Letter to James Platt to provide comments on flow
modeling and 30% design report
Letter to James Platt to clarify statement in
1/8/1 997 letter
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Author
Harding Lawson Assoc.
Harding Lawson Assoc.
Hydro-Geo Services, Inc.
Harding ESE
Harding ESE
Harding ESE
US EPA
Harding ESE
Harding ESE
MACTEC
Date
11/15/1996
2/12/1998
1/3/2002
5/10/2002
6/19/2002
7/10/2002
7/24/2002
8/12/2002
8/9/2002
11/13/2002
Title
Responses to EPA Comments on Pre-final Design
Quarterly and Annual Progress Report Period
Ending January 1998
Final Report Act 2 Land Recycling Program Site
Characterization for 1070 Virginia Drive
Quarterly Progress Report Period Ending April
2002
Draft Five-Year Review Report Corrective
Measures Implementation (CMI) Report Period
7/97 through 6/02
Vapor Intrustion Evaluation
Letter providing comments on vapor intrusion
evaluation
Letter responding to EPA comments on vapor
intrusion evaluation
Quarterly Progress Report Period Ending July 2002
Quarterly Progress Report Period Ending October
2002
1.4
PERSONS CONTACTED
The following individuals associated with the site were present for the visit:
Joel Hennessy, EPA Region 3
Mike Cramer, EPA Region 3, Environmental Scientist
Darius Ostrauskas, EPA Region 3, EPA Project Manager for Honeywell Fort Washington Site
Emil Walerko, Honeywell, Project Leader, Health Safety, Environment and Remediation
James Platt, Honeywell, Manager, Facilities and Services - East
Randy Talbot, P.E., Harding ESE, Infrastructure Manager
J. Vincent Saleski, MACTEC, Senior Hydrologist
1.5
1.5.1
SITE LOCATION, HISTORY, AND CHARACTERISTICS
LOCATION
The Honeywell facility is located at 1100 Virginia Drive in Upper Dublin Township, Montgomery
County, Pennsylvania in the Fort Washington Industrial Park. The property is approximately 67 acres
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and owned by 1100 Virginia Drive Associates. The main building is 861,000 square feet. The remainder
of the property is an asphalt parking lot and grass. The site is bordered by Virginia Drive and then the
Pennsylvania Turnpike to the south. Camp Hill Road and a residential area borders the site on the north.
Undeveloped property is located immediately to the west. Commercial and industrial area is located
further to the west and also borders the site to the east. Figure 1-1 provides a map of the site and the
surrounding area.
The facility was built in 1964, and at the time, was the largest manufacturing facility east of the
Mississippi River. The facility was primarily used for the manufacturing of electronic controls and
mechanical valve assemblies. In 1986, Honeywell sold the property but continues to lease office space.
A portion of the main building (approximately 103,000 square feet) is also used by the DeVry University.
Soil sampling related to a tank excavation in 1986 provided the first documented presence of subsurface
contamination. Further investigations revealed ground water concentrations of trichloroethene (TCE)
exceeding 10,000 ug/L. A pump and treat (P&T) system operates at the facility as a final remedy, which
is the focus of this RSE. A brief site chronology is provided below:
1964 - Facility is constructed and manufacturing begins
1986 - Honeywell sells property but continues to lease office space
1986 - 1991 - Nine phases of environmental investigations are performed, indicating ground
water and soil vapor are contaminated with TCE. Former UST 8 is identified as
the likely source of TCE. Approximately 22 monitoring wells/piezometers are
installed in either the overburden or bedrock as part of these investigations.
1992 - Ground water sampling identifies TCE in MW-9D exceeding 85,000 ug/L
1993 - Surface water sampling identified TCE at concentrations below the Maximum
Contaminant Levels (MCLs) and consistent with background levels.
An Ecological Assessment identifies Pine Run Creek as the only potential
ecological receptor of contaminated ground water and that short-term and future
impacts were likely minimal.
Interim remedial measures includes extraction of ground water at a total rate of
0.5 gpm from RW-1 and RW-2 and treatment via granular activated carbon
(GAC). Operation of this system continues through July 1997 when construction
of the final remedy is completed.
1994 - USEPA Final Decision and Response to Comments specifies that the Corrective
Measures Objectives are to restore ground water to MCLs.
Honeywell contractors complete a Bedrock Investigation.
Honeywell submits a Draft Results of Risk Assessment Activities and Corrective
Measures Study.
Honeywell contractors performs an Aquifer Performance Test and UV Oxidation
(UVOX) Treatability Study.
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1996 - EPA approves of decommissioning MW-11 due to its location within the Fort
Washington Expo Center.
Honeywell contractors conduct ground water flow modeling in conjunction with
final remedy design.
Honeywell submits the final design for the final remedy P&T system.
1997 - Final remedy begins operation. Active remediation includes ground water
extraction and treatment of ground water at a total rate of approximately 10 gpm.
1999 - EPA approves removing benzene from the list of compounds of interest (COI)
due to benzene concentrations below the MCLs for three consecutive sampling
events.
EPA approves of discontinuing analysis for inorganics and to reduce treatment
plant influent sampling from monthly to quarterly.
2000 - EPA approves of reducing the sampling frequency of residences along Camp
Hill Road from annual to biannual.
2001 - EPA approves of decommissioning MW-12 due to its potential for disrupting
security and activities within the building for a different tenant.
2002 - EPA approves decommissioning of MW-8 and RW-2. A replacement well for
MW-8 is installed.
Honeywell submits a Vapor Intrusion Study of the main building at the site using
the Johnson and Ettinger (J&E) model. Results of the study suggest risks are
considered negligible. Further evaluation suggests that the building is under
positive pressure thereby preventing the influx of contaminant vapors into the
building from the subsurface. EPA suggests the need for further evaluation.
2003 - DeVry University begins classes in the main building.
1.5.2 POTENTIAL SOURCES
The original source of contamination is assumed to be former UST 8 due to its location relative to ground
water contamination and its use for storing TCE. Although UST 8 has been removed and releases are not
continuing, ground water concentrations of TCE are indicative of dense non-aqueous phase liquid
(DNAPL) in the vicinity of former UST 8. MW-9D is located adjacent to the location of former UST 8
and dissolved TCE concentrations in this well have exceeded 15,000 ug/L since 1997 despite continuous
pumping from nearby RW-3. Solubility of TCE in water is approximately 1,100,000 ug/L at 20 C
(Groundwater Chemicals Desk Reference, 1991). Therefore, TCE concentrations have consistently
exceeded 1% of the reported solubility for over 5 years.
As DNAPL continues to dissolve in the ground water, it serves as a continuing source of dissolved
ground water contamination. Although DNAPL has not been directly observed at the site, its presence
(perhaps in the residual form) might explain the persistent elevated concentrations at MW-9D.
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1.5.3 HYDROGEOLOGIC SETTING
The site elevation is approximately 190 feet above mean sea level (MSL) and slopes gently to the south
from the source area to Pine Run Creek. A steep rise in elevation to approximately 220 feet is present
from the source to Camp Hill Road to the north. A northwest/southeast geological cross-section (along
strike) from the 1993 RCRA Facility Investigation (RFI) report is presented in Figure 1-2. The upper
portion of the subsurface, referred to as Zone A in the RFI report, consists of unconsolidated materials,
predominantly fill and alluvial sediments. The thickness of Zone A ranges from approximately 20 feet
near the southern property boundary to approximately 4 feet near the source area to no appreciable
thickness near the northern property boundary.
Beneath Zone A is bedrock consisting of alternating layers of silstone/shale, sandstone, and shale.
Regional dip of these layers is to the northwest at approximately 11 degrees from horizontal. The RFI
report categorizes bedrock into two zones (not distinguished in Figure 1-2):
Zone B consists of weathered, highly fractured bedrock that is hydraulically connected to Zone
A. The thickness of Zone B varies across the site, and its vertical extent has been observed to an
approximate depth of 60 feet below ground surface (bgs) near MW-1D/MW-2D. It is unclear
from the available data and from discussions during the site visit if Zone B is horizontally
superimposed over the dipping layers or if Zone B dips with the formation.
Zone C is the deeper, fractured portion of the bedrock underlying Zone B. An aquiclude has
been found between Zones B and C, but pumping conducted during the bedrock investigation
suggests that the aquiclude is not continuous across the entire site. For example, the Bedrock
Investigation Report suggests that the aquiclude might not be present near MW-4D.
Another prominent geologic feature at the site that influences ground water flow is a diabase dike located
beneath Camp Hill Road. Geophysical and pumping data presented in the RFI suggests that this dike
serves as an impermeable barrier to ground water flow to the north.
The depth to water at the site varies with time, but the RFI report suggests that ground water elevation
ranges across the site from approximately 2 feet bgs near former UST 8 to 7 feet bgs at the southern
property boundary.
In Zone A, ground water flows to the south but is intercepted by the former bed of Pine Run Creek (the
creek was moved further south to its current location prior to facility construction). The former creek
bed runs east-west, and ground water turns to the west along this buried feature.
Ground water flow in Zones B and C is more complicated. For example, the RFI suggests that ground
water flow is influenced by a downward flow component that is deflected in the direction of bedding dips
and along fractures. Principal fracture directions are reportedly along strike (northeast to southwest) and
perpendicular to strike (northwest to southeast). The hydraulic conductivity in Zone B is several orders
of magnitude higher than in Zone C.
1.5.4 POTENTIAL RECEPTORS
The current potential receptors in the area are as follows:
Residences using ground water to the north of the property on the other side of Camp Hill Drive
are potential receptors for ground water contamination.
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The DeVry University building on site is a potential receptor for contaminant vapors.
Pine Run Creek, which flows along the southern border of the site and off to the west, is a
potential receptor for ground water contamination.
Each of the potential exposure pathways to these potential receptors are discussed further in Section 5.0
of this report. Potential receptors also include potential future users of impacted ground water and
occupants of potential future buildings on the neighboring property at 1070 Virginia Drive.
1.5.5 DESCRIPTION OF GROUND WATER PLUME
The ground water plume in Zone A (unconsolidated material) extends to the south/southwest from the
source area and onto the neighboring undeveloped property at 1070 Virginia Drive as evidenced by
sampling from HGS-1, HGS-2, HGS-3 and grab samples taken during soil borings in 2001. The
maximum sampled TCE concentrations for HGS-1, HGS-2, and HGS-3 are 270 ug/L, 18 ug/L, and 48
ug/L, respectively. Concentrations in Zone A at the facility and immediately downgradient of the source
zone are typically on the order of 1,000 ug/L.
In Zones B and C, TCE concentrations are generally above 100 ug/L. The plume in these zones appears
to extend from the source area to the northwest toward MW-4D (a pumping well) and to the north
(upgradient but down dip) toward MW-27. The greatest TCE concentrations are repeatedly measured in
MW-9D and RW-3 (a pumping well). Concentrations in MW-9D are persistently above 16,000 ug/L.
Concentrations in RW-3 have decreased from 30,000 ug/L but appear to be asymptotically approaching a
value of 5,000 ug/L or higher.
Figure 1-3 depicts the extent of contamination by presenting ground water sampling and analysis results
from October 2002. The 2001 sampling results from the site characterization of 1070 Virginia Drive are
also included.
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2.0 SYSTEM DESCRIPTION
2.1
SYSTEM OVERVIEW
The P&T system extracts ground water from two recovery wells, treats the extracted water with
UV/oxidation (UVOX) and polishing with GAC, and then discharges treated water to the POTW.
2.2
EXTRACTION SYSTEM
The extraction system consists of 2 recovery wells, RW-3 and MW-4D equipped with transducers and
0.75 HP electric submersible Grundfos pumps. The extraction wells are located 200 feet (RW-3) and
500 feet (MW-4D) from the former UST source area. MW-4D is completed with open hole from 47 to
57 feet bgs. RW-3 has a stainless steel screen from 10 to 50 feet bgs. The pumping rate at each well is
throttled (a throttling valve is present at each well head) so that a continuous flow is maintained to the
extent possible while the water level is between the high and low transducer set points. Ground water is
routed separately from each well underground to the treatment building through double containment (1.5-
inch diameter polypropylene carrier pipe with 3-inch diameter PVC containment pipe). The flow rate
from the two wells combined is about 9 gpm, but the flow rate from each well might vary from month to
month. The lines from each well enter the treatment building and include individual Y-strainers,
sampling ports, check and globe valves and flow meters prior to being combined in a 2-inch diameter
polypropylene line to enter the equalization tank.
The extraction well and blended treatment plant influent parameters are summarized in the following
table.
Extraction
Well
RW-3
MW-4D
Formation
Screened
Zone B/C
Zone B/C
Plant Influent
Extraction Rate
(gpm)
4.5*
4.5*
9.0
TCE
Cone.
(ug/L)
6,900
300
3,600
TCE Pounds
Per Day
(Ibs/day)
0.37
0.016
0.386
% of mass
Extracted
96%
4%
100%
Extraction rates and concentrations taken from October 2002 Progress Report
Influent values are calculated based on extraction -well data.
* The extraction rate in each -well might vary from month to month, but the 4.5 gpm for each well from the October 2002
Progress report is representative
2.3
TREATMENT SYSTEM
The treatment system is housed in 25-foot by 28-foot concrete block building with a roll-up door and two
10 KW heaters. The treatment system has an autodialer and a modem that allows remote viewing of
water levels in wells, the EQ tank, and alarm conditions to be viewed remotely.
The treatment system is designed to treat an average flowrate of 10 gpm and a maximum of 30 gpm. The
design influent concentrations are as follows:
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100,000 ug/L trichloroethene (TCE)
100 ug/L 1,2-dichloroethene (1,2-DCE)
880 ug/L 1,1-dichloroethene (1,1-DCE)
20 ug/1 1,1 -dichloroethane (1,1 -DCA)
3 ug/1 1,2-dichloroethane (1,2-DCA)
Therefore, the design mass removal rate is approximately 12 to 36 pounds per day of TCE (and
approximately 0.1 pounds per day of other constituents), compared to the current mass removal rate of
0.39 pounds per day of TCE. The treatment consists of the following components:
Equalization Tank: This is a 1,625 gallon flat bottom polyethylene tank. It receives water from the 2
extraction wells, the building sump and purge water from monitoring well sampling. Water is transferred
from the tank by a 2 HP centrifugal process feed pump that operates based on level controls in the EQ
tank.
Bag Filters: Water is routed form the EQ tank through 2 parallel bag filters, Rosedale PolyPro 8 models.
The bag filters are equipped with a differential pressure alarm to notify the operator when the filter bags
require changing. Ten micron bags are used in the filters.
UVOX System: After the bag filters hydrogen peroxide is added to the process water at a rate of about
28 ml/minute and mixed with a static mixer prior to the water entering the oxidation unit. It is a 30 KW
Calgon oxidation unit with 6 UV bulbs and a hydrogen peroxide storage tank with metering pumps and a
2HP air compressor. The unit operates on a batch basis. It is activated when flow from the process
transfer pump starts. A minimum of about 10 gpm and an average rate of about 15 gpm is maintained
through the unit.
Liquid GAC Units: Following the UVOX system water is routed to two liquid GAC units operated in
series. Each of these units contains 1,000 pounds of GAC. Following the GAC units the process water is
discharged to the POTW.
2.4 MONITORING PROGRAM
The POTW requires monthly effluent sampling from each of the GAC units. Other process monitoring is
conducted quarterly in conjunction with the ground water monitoring. Quarterly samples are collected
from the following process locations:
the RW-3 extraction well influent
the MW-4D extraction well influent
the blended influent to the UVOX system (before the hydrogen peroxide addition)
the UVOX effluent
effluent from the first GAC unit
effluent from the second GAC unit
Analyses of all samples are provided on a three-week turnaround with the exception of the effluent from
the first GAC unit, which is provided on a one-week turnaround. If the analysis shows no detection, then
the sample of the effluent from the second GAC unit is discarded. It should also be noted that samples
are occasionally collected and analyzed after the process water flows through four of the six UVOX
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chambers to determine the UVOX effectiveness. Effluent from the UVOX system is analyzed on-site for
hydrogen peroxide with a Hach test kit.
In addition to quarterly monitoring of the extraction wells, the ground water monitoring program consists
of both quarterly and semi-annual monitoring as presented in the following table.
Quarterly (13 Monitoring Wells)
MW-01 MW-17
MW-19
MW-20
MW-26
MW-27
MW-02D
MW-03D
MW-05
MW-07D
MW-08D
MW-16
MW-28
Semi-annually (2 Monitoring wells)
MW-9D
MW-25
Samples are analyzed with EPA SW846 Method 802 Ib ("802 lb"). Four surface water samples are
collected from Pine Run Creek semi-annually and samples from four residences across Camp Hill Road
are sampled bi-annually (once every two years).
Ground water elevations are collected quarterly and potentiometric surface maps are prepared and
included with the quarterly progress reports.
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3.1
3.0 SYSTEM OBJECTIVES, PERFORMANCE AND CLOSURE
CRITERIA
CURRENT SYSTEM OBJECTIVES AND CLOSURE CRITERIA
The 1994 Statement of Basis indicates that the only medium requiring corrective measures is ground
water. The stated goal of the corrective measures is to restore the ground water to its beneficial use,
which would be drinking water. EPA has established the cleanup standards as the MCLs, which are
listed below. Although benzene was originally considered a contaminant of concern, EPA approved of
removing it as a contaminant of concern in 1999 because it had been absent in three consecutive
monitoring events.
Compound
1,1 -DCE
PCE
TCE
Vinyl chloride
MCL
7
5
5
2
ug/L
ug/L
ug/L
ug/L
Points of compliance are established as MW-1, MW-9D, and MW-25.
3.2
TREATMENT PLANT OPERATION STANDARDS
Treated water is discharged to the POTW, which limits the system discharge rate to 15 gpm. The POTW
limits are MCLs which are similar to the expected surface water discharge limits. Honeywell indicated at
the site visit that they chose the POTW discharge mainly to avoid potential liability issues associated
with discharge to surface water.
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4.0 FINDINGS AND OBSERVATIONS FROM THE RSE SITE VISIT
4.1 FINDINGS
The RSE team observed an extremely well-managed remedy. Honeywell, their contractors, and EPA all
have an excellent understanding of the site conditions, the remedy, and potential risks. Continuing efforts
have been made by the site team as a whole to improve system operation and protect human health and
the environment. 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 and the public. These observations obviously 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 table elevations collected both prior to and after pumping are depicted in Figures 4-1 and 4-2. In
general, only the overburden wells are used in generating the potetiometric surface maps. Therefore,
these potentiometric surfaces do not necessarily indicate ground water flow in Zones B and C. Shallow
ground water, in the absence of pumping, flows to the south. In the presence of pumping, drawdown in
the two extraction wells appears to be approximately 15 feet relative to other nearby monitoring points.
Including the water levels from these pumping wells in the development of the potentiomentric surface
maps might over estimate the degree of drawdown in the surrounding aquifer. The use of nearby
monitoring (non-pumping) wells in developing potentiometric surface maps is generally preferred over
pumping wells because pumping wells might be subject to well losses and generally are not
representative of surrounding aquifer. If such wells are not available, including an adjustment for well
losses to the extraction well water levels is often appropriate.
Analysis of the water levels in the non-pumping deeper wells (MW-1D through MW-3D and MW-5D
through MW-8D) also indicate hydraulic gradients to the south. For example, in October 2002, MW-3D
to the north had a water level of 188.44 feet MSL and MW-8D to the south had a water level of 174.84
feet MSL. The other deep wells also consistently indicated hydraulic gradients to the south.
Hydraulic gradients at this site do not necessarily indicate the direction of ground water flow and
contaminant transport because fractures run down dip or along strike. For example, TCE is present in
both MW-9D and MW-27, which are upgradient of the source with respect to the regional gradient but
are down dip. Contaminant transport down dip might be due to ground water flow directed through
preferential flow paths that are aligned in that direction or might be indicative of either past or present
NAPL migration.
4.2.2 CAPTURE ZONES
The P&T capture zone in hydrogeologic Zones A and B is evaluated in the June 2002 Draft Five-Year
Review. Two lines of evidence are used to analyze the capture zone:
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the potentiometric surface
the concentration trends in monitoring wells located downgradient of the extraction wells
In addition, ground water modeling and particle tracking were used to evaluate capture during system
design. This modeling (summarized in the May 1996 modeling report) indicates that pumping rates
similar to those sustained by RW-3 and MW-4D would be sufficient for capture. It does not appear that
the performance of the ground water model has been evaluated based on actual system operation and
response.
Potentiometric surface maps show an influence due to pumping, but as stated in Section 4.2.1, their
development includes the use of water levels from operating pumping wells. As a result, the degree of
drawdown and capture might be overestimated when using these potentiometric surface maps.
Furthermore, as the Draft Five-Year Review indicates, the presence of complex geology with dipping
beds and fracture orientations in three directions complicates analyses of ground water flow directions,
particularly in Zone B.
The Draft Five-Year Review discusses the concentration trends in MW-1, MW-16, MW-17, MW-19,
MW-20, MW-25, MW-27, and MW-28 as part of a capture zone analysis. The RSE team provides the
following observations on capture based on concentration trends in monitoring (non-pumping) wells.
TCE concentrations in MW-1 and MW-28 appear to have decreased since pumping began. The
concentrations in MW-1 have decreased from over 1,000 ug/L to under 50 ug/L and the
concentrations in MW-28 have decreased from over 10,000 ug/L to approximately 1,000 ug/L.
These decreases might indicate that either 1) these wells are within the capture zone and the TCE
is diluted by entrainment of cleaner water or 2) they are located downgradient of the capture zone
and less TCE contamination is able to migrate to these wells from the upgradient portion of the
plume. It is also possible that MW-28 is within the capture zone and that MW-1 is downgradient
of the capture zone. If this is the case, then the following would be expected:
MW-28 would continue to have elevated TCE concentrations as long as TCE is present
in the source area.
MW-1 would be expected to cleanup over time, even if contamination remains in the
source area, as long as capture is complete.
The potentiometric surface maps appear to suggest that MW-28 is within the capture zone and
MW-1 is downgradient of it, but insufficient water level data are available for a conclusive
determination.
Due to the relatively large distance between the pumping wells and monitoring wells MW-7D,
MW-8D, MW-16, MW-17, MW-19, and MW-20 it is relatively safe to assume that these wells
are downgradient of the capture zone. As such, if capture is complete, the TCE concentrations in
these wells should remain at or decrease to undetectable levels over time. Because ground water
flow is generally slow, achieving undetectable concentrations might take years to observe. The
following trends in these wells have been observed:
TCE concentrations in MW-8D and MW-16 were undetectable before pumping and have
remained undetectable.
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TCE concentrations in MW-7D and MW-17 were detectable near the MCLs before
pumping and have remained at this level. No detectable trend is present.
TCE concentrations in MW-19 were present at concentrations above 100 ug/L prior to
1999, but have not exceeded that level in 16 consecutive monitoring events. A
discernible decrease is not readily observable from visual inspection, but the data show
that concentrations are not increasing.
TCE concentrations at MW-20 have remained at or below the MCLs, no discernible
trend is evident from visual inspection.
These six downgradient monitoring wells do not show that capture is compromised. Continued
monitoring at these four locations and MW-1 will likely help determine the extent of capture over time.
Given that substantial decreases have been evident in MW-1 and MW-28, decreasing trends in MW-16,
MW-17, MW-19, and MW-20 will likely occur in the future. If concentrations at these four wells and
MW-1 continue to decrease or remain below MCLs, capture is likely sufficient to the south.
Other downgradient wells include HGS-1, HGS-2, HGS-3 and MW-15. These wells were sampled
during characterization of the neighboring property at 1070 Virginia Drive but are not sampled as part of
the ground water monitoring program for the Honeywell site. In 2001 all four wells had detectable
concentrations of TCE, and HGS-1 and MW-15 had TCE concentrations over 100 ug/L. This
contamination could have been present before the system began operation, and because limited sampling
has been conducted, long-term trends cannot be established and used for a capture zone evaluation.
No such sentinel wells are available to the west beyond (i.e., to the west of MW-4D or MW-1).
Therefore, a similar evaluation of capture with trend analyses in this area is not feasible. Site
characterization activities of 1070 Virginia Drive showed undetectable TCE contaminated ground water
samples from direct-push borings S-4 and S-10, which are immediately west of MW-4D. These samples
are limited to the overburden and demonstrate that contamination has not migrated west of MW-4D in
Zone A. Data are not available to confirm that migration has not occurred in Zone B of this area.
The above analyses do not consider the potential for DNAPL migration in Zone C along the bedding
planes. TCE concentrations at MW-9D and MW-27 indicate that contamination has migrated down dip
to the northwest. This might be due to ground water flow or to DNAPL migration, and it is unclear if
such migration continues. TCE concentrations at MW-9D have remained above 16,000 ug/L but have
not increased over time. TCE concentrations at MW-27 have generally remained above 200 ug/L and at
times have increased to over 1,000 ug/L, but a consistent increasing or decreasing trend is not readily
apparent from visual inspection. MW-25, which is further downgradient of MW-27, has undetectable
TCE concentrations, but site records indicate that this monitoring well is not screened in the same
fracture zone as MW-9D and MW-27. Therefore, it is difficult to determine the extent of or the potential
for the migration of TCE contamination along the MW-9D fracture zone. The hydrogeologic conceptual
model suggests that contamination is contained by the diabase dike and the decreasing permeability with
depth. Continued undetectable TCE concentrations overtime at the three residences along Camp Hill
Road and TCE below MCLs at the fourth residence could help confirm that the diabase dike prevents
further contaminant migration to the northwest. It should be noted, however, that increases in TCE
concentrations at these wells could also be due to an offsite source.
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4.2.3 CONTAMINANT LEVELS
Contaminant concentrations in the two recovery wells (RW-3 and MW-4D) and MW-1, MW-9D, and
MW-28 can be evaluated to indicate progress toward restoration. The RSE team provides the following
observations of concentrations in these five wells. The RSE team also provides its conclusions/opinions
as to what these concentration trends imply for the P&T remedy.
In RW-3, TCE concentrations have decreased from 30,000 ug/L prior to pumping to
approximately 5,000 ug/L. Although this represents a substantial decrease in concentrations over
a 5-year period, the TCE concentrations in RW-3 appear to have stabilized above 5,000 ug/L.
The Draft Five-Year Review fits a power model to this concentration trend that, when
extrapolated, suggests cleanup in that well will be reached in approximately 35 years. This
estimate from a statistical model only takes into account the trend in the data and does not fully
represent the hydrogeology and contaminant transport. In addition, the model does not fit the
trend exactly and may not provide accurate estimates through extrapolation. As a result, this
estimate should be taken with caution.
In MW-4D, TCE concentrations have decreased from over 1,000 ug/L prior to pumping to
approximately 200 ug/L. This also represents a substantial decrease in contamination over a 5-
year period. Concentrations appear to have stabilized above 200 ug/L. The Draft Five-Year
Review fits a power model to this concentration trend that, when extrapolated, suggests cleanup
in that well will occur in approximately 10 to 15 years. As with the estimate from the statistical
model used for RW-3, this estimate should be taken with caution.
As stated in Section 4.2.2, the concentrations in MW-1 and MW-28 have decreased. These wells
are either within the capture zone or are downgradient of the capture zone. As of yet, the TCE
concentrations in these two wells have not dropped below cleanup standards. If they are located
within the capture zone, then concentrations will likely remain above standards until the TCE in
the source area is removed. If they are located downgradient of the capture zone, and capture is
complete, then these wells will likely reach cleanup standards even if TCE remains in the source
area, but this may take many years to occur.
In MW9D, concentrations remain above 16,000 ug/L and show no discernible or consistent
decrease since pumping began. Therefore, with the current remedy and a goal of restoring the
aquifer to MCLs, it is reasonable to assume that pumping and treating will continue indefinitely.
4.3 COMPONENT PERFORMANCE
4.3.1 EXTRACTION SYSTEM WELLS AND PUMPS
The average pumping rates from RW-3 and MW-4D vary on a weekly basis. For example, between May
and July 2002, the RW-3 extraction rate varied from 4.5 gpm to 6.3 gpm when the pump was operating.
During the same time period, the MW-4D extraction rate varied from 3.5 gpm to 4.4 gpm. These
variations are likely due, in part, to variation in the regional water table but also due to fouling or
corrosion. The pump in RW-3 has been replaced or repaired at least five times since 1998, and the MW-
4D pump was cleaned in October 2002 due to heavy build up of ferric hydroxide. The pump columns
were also replaced with stainless steel 316 to reduce the potential for corrosion.
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4.3.2
FILTERS
Changeouts of the bag filters are infrequent, less than monthly. This indicates that the water has minimal
suspended solids and iron. Corrosion of one filter housing resulted in a leak and corrosion of the other
housing was also observed. Both housings were replaced in the second quarter of 2002. It is reasonable
to expect that such replacements might be required every 5 years.
4.3.3
UVOX SYSTEM
According to the Draft Five-Year Review, the UVOX system has required non-routine service on three
separate occasions between 1998 and June 2001. Problems included a faulty circuit breaker, a
malfunctioning feed pump controller, and the internal computer program. All issues were addressed and
down time from these problems totaled approximately 87 days. Other system shutdowns have occurred
because of a low flow rate condition (i.e., when the flow rate to the UVOX system drops below the
required 15 gpm). When the UVOX system performs as expected, it has a removal efficiency of greater
than 99%.
4.3.4
GAC
On average, one of the 1,000-pound GAC units is changed out once per year. The GAC in the lead unit is
changed and the two units are rearranged so that the secondary unit becomes the lead unit and the unit
with the replaced GAC becomes the new secondary unit. This frequency for GAC changeouts (i.e., 1,000
pounds per year) is approximately double what would be expected based on mass loading to the GAC
units (assuming 99% removal of contaminants by the UVOX system) and their expected chemical
loading capacity. The site contractor states that increased frequency in changeouts is due to channeling
in the GAC units caused by a buildup of air pressure. Since the RSE site visit, the installation of a
pressure-relief valve has increased the efficiency of the GAC units and will likely reduce the changeout
frequency.
4.4
COMPONENTS OR PROCESSES THAT ACCOUNT FOR MAJORITY OF
MONTHLY COSTS
The facility specifies that the treatment system operating budget is $220,000 for 2003. This includes
labor, utilities, materials, analytical costs, and disposal costs. An approximate breakdown of these costs
is presented in the following table based on estimates provided by the facility and estimates prepared by
the RSE team based on the remedy scope of work. The assumptions and estimates made in generating
the table are discussed in the following subsections.
Item Description
Labor (project management, reporting, monitoring, maintenance, etc.)
Utilities: Electricity
Non-utility consumables (GAC, chemicals, other materials or parts)
Chemical Analysis
Discharge fees and waste disposal
Total Estimated Cost
Estimated Cost
$130,000
$30,000
$16,000
$20,000
$24,000
$220,000
% of Total
Costs
59%
14%
7%
9%
11%
100%
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4.4.1 UTILITIES
The primary power draw for the system is the UVOX system, which utilizes 30 KW for the UV bulbs.
Assuming 100% uptime, this translates to over 250,000 kWh (kilowatt hours) per year. Assuming $0.10
per kWh, this translates to approximately $25,000 per year in electrical costs. Space heaters (two 10 KW
heaters used part-time during the winter), extraction pumps, and transfer pumps would also contribute to
the power draw of the remedy. Therefore, it is reasonable to assume that electrical costs are
approximately $30,000 per year and are primarily due to the UVOX system.
4.4.2 NON-UTILITY CONSUMABLES AND DISPOSAL COSTS
Materials include hydrogen peroxide, GAC, and replacement bulbs and parts for the UVOX system. The
facility estimates that the hydrogen peroxide costs approximately $4,500 per year, the GAC costs $5,000
per year, and the UVOX bulbs cost $6,000 per year. This translates to a cost of approximately $16,000
per year in non-utility consumables.
The facility has not recently been invoiced by the POTW; therefore, an actual cost cannot be determined
for the past year. However, the POTW charges a reported $0.005/gallon and the average discharge rate is
approximately 9 gpm. Assuming 100% uptime, this translates to an annual cost of approximately
$24,000 per year.
4.4.3 LABOR
Labor at the site includes project management, reporting, ground water sampling, and P&T system
maintenance. A facility employee checks the system twice per week, and the labor associated with those
checks is not included in the $220,000 budget. The facility estimates that the labor costs are
approximately 60% of the total budgeted costs, or approximately $130,000 per year.
4.4.4 CHEMICAL ANALYSIS
The facility estimates that a total of 30 samples are analyzed using 802 Ib each quarter for process and
ground water monitoring combined. In addition, 4 surface water samples are analyzed twice a year and 4
residential well samples are analyzed once every two years. The POTW requires monthly effluent
sampling. Therefore, including field blanks and other quality assurance samples, approximately 160
samples per year are analyzed, and the large majority of these samples are analyzed with 802 Ib.
The unit cost for 802 Ib at this facility is approximately $85; therefore, according to these assumptions,
analytical costs are approximately $14,000 per year. The facility estimated that the analytical costs were
approximately 16% of the total budget, which would suggest an annual cost of $35,000. The value
provided in the table is a compromise between the RSE and facility estimates. The value is closer to the
RSE estimate because the facility estimate might be based on a review of past costs that might not be
indicative of current or future costs.
4.5 RECURRING PROBLEMS OR ISSUES
The majority of system downtime or reduced performance is due to upsets to either the UVOX system or
the pump in RW-3. RW-3 appears susceptible to corrosion that has resulted in replacement or repair on
five separate occasions (an average of one replacement per year). The UVOX system has had three
separate instances of non-routine repair, all due to different causes.
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4.6 REGULATORY COMPLIANCE
The treatment system regularly meets the POTW discharge requirements.
4.7 TREATMENT PROCESS EXCURSIONS AND UPSETS, ACCIDENTAL
CONTAMINANT/REAGENT RELEASES
Minor leaks have been reported but have been contained by secondary containment. One reported leak
was due to corrosion in one of the bag filter housings. A small drip prior to the UVOX system was noted
during the RSE site visit, and it was understood that the drip would be corrected immediately.
4.8 SAFETY RECORD
The facility has no reported 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
Contaminated ground water has the potential to impact Pine Run Creek to the south and west
(hydraulically downgradient) and residential supply wells screened in bedrock to the north (hydraulically
upgradient but down dip). The Draft Five-Year Review reports that surface water samples are collected
semi-annually. Four locations along the stream are sampled, and the highest TCE concentration is
repeatedly detected in the sample collected upstream from the site in the east corner of the property (SW-
4). Therefore, the Draft Five-Year Review concludes that site-related contamination is likely not
adversely impacting the stream, and an upgradient source of TCE might exist. In the opinion of the RSE
team, these appear to be reasonable conclusions.
No compounds of interest have been detected in three of the four sampled residential wells. The fourth
well (at 1200 Camp Hill Road) has TCE below MCLs and the RFI identifies several lines of evidence to
suggest why the TCE detected in that well is not related to the former Honeywell facility. These lines of
evidence are summarized below:
1200 Camp Hill Road is hydraulically upgradient from the facility.
1200 Camp Hill Road is located on the opposite side of the diabase dike, which site data indicate
is a barrier to ground water flow.
Chloroform has been identified in the well at 1200 Camp Hill Road but has not been detected in
MW-25, which is the closest on-site monitoring well, and has only sporadically been detected on
site. (A review of the historical ground water monitoring data indicates that chloroform has been
detected 5 times in on-site monitoring wells in all of the long-term monitoring samples collected
since 1997 and reported in the October 2002 progress report. The highest concentration was 0.9
ug/L in MW5 in 1998. Chloroform is also a common laboratory contaminant, which might be
the cause of the sporadic detections in both the on-site and residential samples.)
Napthalene has been identified in the well at 1200 Camp Hill Road but is not a site compound of
interest or a breakdown product of a compound of interest.
TCE has been detected numerous times in samples collected from background well MW3D,
suggesting that there is an upgradient source of TCE.
In the opinion of the RSE team, these lines of evidence are relatively convincing and the RSE team
generally agrees that the impacts at 1200 Camp Hill Road are likely due to another source. The
following issues, however, should be noted:
Although 1200 Camp Hill Road is hydraulically upgradient, it is down dip from the facility and
TCE has been found in down dip locations such as MW-27.
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Although MW-25 is the closest on-site well to 1200 Camp Hill Road, it is not completed in the
same fracture zone as MW-27. Therefore, TCE contamination might be present at the location of
MW-25 or beyond but not at the elevation screened by MW-25.
With respect to potential future ground water users, institutional controls could help prevent or control
use of ground water in or in the vicinity of the plume until it is restored. However, such controls are not
part of the current remedy and otherwise not known to be in place.
5.2 SURFACE WATER
As stated in Section 5.1, surface water shows that contaminated ground water from the site is not likely
impacting Pine Creek Run.
5.3 AIR
A vapor intrusion evaluation for the site main building is currently underway by the facility contractors.
The evaluation to date has included a preliminary screening analysis conducted with the Johnson and
Ettinger model and a review of the building HVAC information. The HVAC information suggests that
the building (at least the DeVry portion of the building) is maintained at a higher pressure (2.46 Pascals)
than ambient. The Johnson and Ettinger model is not applicable when the building pressure is higher
than the ambient pressure. So the facility has conducted the model simulations with a nominal negative
pressure differential of 0.01 g/cm-s2 (or 0.001 Pascals). The facility also used many of the default
parameters for the model, including the default soil vapor permeability of 10"8 cm2 for sand. The results
of these model simulations suggest that in order to exceed a 10"5 incremental risk, the TCE ground water
concentration would need to be over 2,000,000 ug/L, which is above the water solubility of TCE and two
orders of magnitude higher than the highest ground water TCE concentrations found on site. The model
also calculates that to exceed an incremental risk of over 10"6, a TCE ground water concentration of over
300,000 ug/L would be required.
If the model is run with the same parameters, but with a pressure differential of 0.1 gm/cm-s2 and the
upper limit of soil vapor permeability for a medium sand (10~6 cm2 as stated in the Johnson and Ettinger
model user's guide), then the model suggests that a ground water TCE concentration of approximately
16,000 ug/L would result in a 10"5 incremental risk. The model also suggests that a ground water TCE
concentration of approximately 1,600 ug/L would result in a 10"6 incremental risk. The highest TCE
ground water concentration found on site is approximately 18,000 ug/L at MW-9D.
Because the model cannot use a positive pressure differential, the model is likely not appropriate for the
vapor evaluation at this site. Using nominally low pressure differentials could provide misleading
results. Rather, a more appropriate vapor evaluation would likely rely on data that confirm that the
positive pressure differential is maintained throughout the building and/or vapor sampling within the
building. As of the RSE site visit, actual pressure differentials between the building and ambient
conditions had not been measured and vapor sampling within the building had not been conducted.
Vapor intrusion could potentially become an issue at 1070 Virginia Drive if buildings on that property
are constructed and occupied. An evaluation of this potential exposure would require more information
about the current and future TCE concentrations in the subsurface of 1070 Virginia Drive as well as the
building construction and HVAC parameters.
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5.4 SOILS
With respect to direct exposure, soils on site do not pose a human health risk. The site is covered by
asphalt or by buildings such that contaminated soils, if any remain, are out of reach of human contact. If
subsurface construction or utility work were to occur on-site, soil vapors might pose a potential health
risk. It is unclear to the RSE team if any deed restrictions are in place to specify the health and safety
practices to be considered if such work is performed.
5.5 WETLANDS AND SEDIMENTS
The only wetlands or sediments that would potentially be impacted by site-related contamination are
associated with Pine Run Creek. Wetlands and sediments were not evaluated as part of the RSE.
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6.0 RECOMMENDATIONS
Cost estimates provided herein have levels of certainty comparable to those done for CERCLA
Feasibility Studies (-307+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 IN PROTECTING
HUMAN HEALTH AND THE ENVIRONMENT
The primary recommendation in this category is to more fully evaluate the potential for vapor intrusion
into the on-site main building (Recommendation 6.1.1). Otherwise, site data suggest that ground water
contamination from the site is not adversely impacting Pine Run Creek or the residential wells along
Camp Hill Road. Therefore, the RSE team has limited suggestions (Recommendation 6.1.2) for
improving the protectiveness of this remedy with respect to contaminant transport in ground water.
6.1.1 FURTHER EVALUATE POTENTIAL FOR VAPOR INTRUSION
The highest TCE ground water concentrations based on ground water monitoring data are outside of but
adjacent to the building footprint. TCE in ground water has also been detected beneath the building
footprint. MW-21 was historically sampled twice with TCE concentrations of 270 ug/L in July 2000 and
250 ug/L in October 2000. TCE was historically detected in MW-12 (with concentrations ranging from
1,900 ug/L in July 1997 to!60 ug/L in October 2000). Although these concentrations in MW-12 and
MW-21 are relatively low compared to the concentrations in MW-9D and RW-3, the majority of the
property is covered with an asphalt parking lot that might limit the exchange of air in the subsurface and
minimize venting of TCE vapors. As a result, TCE vapors might accumulate in the subsurface and vent
through preferential flow paths that could potentially include cracks in the building floor.
If the building is maintained at a higher pressure relative to the vadose zone, then vapor intrusion into the
building is not likely a concern. The RSE team was told during the site visit that the HVAC information
suggests positive pressure is maintained within the building, but that this has not been confirmed by
measurements of actual conditions. In the opinion of the RSE team, the building should be further
evaluated to confirm that a positive pressure, relative to ambient, is maintained throughout the building.
Alternatively (or potentially additionally), indoor air sampling at multiple locations within the building
could be conducted for confirmation that vapor intrusion is not a human health concern. The nature of
any additional vapor intrusion evaluation work should consider pertinent EPA and Pennsylvania
Department of Environmental Protection guidance. The potential exists that other VOCs or ionizable
gases are used within the building and that PID screening would not be able to distinguish between the
subsurface TCE contamination and these currently used VOCs. The RSE team, therefore, believes that if
sampling is to occur, sampling with Summa canisters and laboratory analysis would be more effective.
Including a work plan, sampling, analysis, and reporting, the RSE team estimates that sampling and
analysis can be conducted for under $10,000. This would include more than 10 TO-14/TO-15 samples
from within the building. Measurements of pressure throughout the building relative to the soil or
atmosphere would likely be significantly less.
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6.1.2 CONSIDER THE INSTALLATION OF Two MONITORING WELLS
The hydrogeology at the site is complex, and this complicates the evaluation of plume capture.
Evaluation of potentiometric surfaces accompanied by trend analyses in downgradient monitoring wells
provides sufficient data to evaluate plume capture to the southeast, south, and southwest. As noted in
Section 4.2, however, data for plume delineation and evaluation of capture to the west and to north could
be augmented.
To the West
Ground water samples from borings (S-4 and S-10), conducted as part of the site characterization of the
neighboring property (1070 Virginia Drive), showed no detectable TCE concentrations in the overburden
to the west of MW-4D and MW-1. These results suggest limited (if any) contaminant migration to west
of MW-4D or MW-1 in the overburden and that capture need not be evaluated in this area. However,
this area is along strike in the bedrock (Zones B/C) and these borings were only completed to a depth of
10.5 feet. Therefore, it is unclear if contaminant migration has and/or continues to migrate through Zones
B/C in this area. Site documents suggest that MW-10D was originally proposed in this area but not
installed. If deemed necessary by the site stakeholders, installation of this well could help determine if
contamination extends to this area. If contamination is present, then a decreasing trend in the
concentration would indicate that capture is sufficient in this direction.
If the site team agrees that installation is merited, the well should be placed sufficiently far downgradient
of the suspected capture zone and completed within Zone B so that it can be used as a sentinel well to
evaluate contaminant migration in this direction. If the well is located within the capture zone, its TCE
concentrations could increase over time, even if capture is sufficient. For there to be adequate capture to
the west of MW-4D, this well should likely have and maintain TCE concentrations below MCLs or
should have TCE concentrations that are declining and eventually fall below MCLs.
To the North
Elevated TCE concentrations at MW-27 suggest the potential for TCE to migrate regionally upgradient
but "down dip" within the MW-9D fracture zone. TCE concentrations in MW-27 exceed 200 ug/L and
the extent of this contamination and the potential for further migration is unknown. MW-25 is located
further to the north/northwest; however, it is not completed within the same fracture zone as MW-9D and
MW-27 and therefore might not intercept an important preferential pathway for contaminant transport in
this direction. An additional well could be installed further down dip of and in the same fracture zone as
MW-27 to better delineate the plume and to provide concentration trends that might be used for
evaluating plume capture within this fracture zone. A preliminary analysis suggests that this well might
be located adjacent to MW-25 but might only be 120 feet deep rather than 190 feet deep.
It is hoped that this additional well would have and would maintain TCE concentrations below MCLs.
This would provide more conclusive evidence that TCE migration is not occurring in this direction.
Installation of this additional well would also provide another location for water level measurements
within the same fracture zone that could be used to better determine if flow in this fracture zone is toward
the extraction at RW-3. In the opinion of the RSE team, this proposed well provides additional useful
information, although other information is available to help evaluate capture in this area and might be
considered prior to installing the well:
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The concentration trend in MW-27 can be analyzed to determine if it is increasing or decreasing.
If it is consistently decreasing and continues to decrease, then at least partial capture is likely
provided. A preliminary analysis by the RSE team shows no detectable trends in MW-27.
The hydraulic gradient between MW-27 and MW-9D can be determined to demonstrate if
ground water flow is toward or away from the extraction at RW-3. If consistent capture is
provided, then ground water flow should be directed toward RW-3. Water level records to date
show that ground water flow between MW-27 and MW-9D alternates between flowing toward
and away from RW-3.
A tracer could be injected into MW-27 to determine what fraction (if any) is recovered by
extraction at RW-3. A different tracer could be injected in MW-9D for a similar evaluation.
Prior to the test, the site team should agree on criteria that would indicate successful capture.
Continued sampling at the residential wells along Camp Hill Road will indicate if site-related
contamination reaches these wells. According to the site conceptual model, however, these wells
would not be impacted due to the hydraulic barrier provided by the diabase dike. Therefore,
even if contamination is migrating in this direction, it might not appear in these wells.
The RSE team estimates that installing the two wells should cost less than $25,000. Monitoring these
wells would increase the annual costs for monitoring, and this increase is considered in Section 6.2.2,
which discusses potential modifications to the ground water monitoring program. Conducting a tracer test
with chloride or bromide tracers (including permitting, development of the test objectives and metrics,
and the final reporting) could likely be done for approximately $10,000. Trend analysis and monitoring
of ground water flow directions should require no additional cost.
6.1.3 MODIFY APPROACH TO EVALUATING PLUME CAPTURE
As is currently the practice, the RSE team recommends interpreting the extent of plume capture by
analyzing potentiometric surface maps and trends in ground water sampling data. However, the RSE
team recommends modifications in developing potentiometric surface maps and including the HGS
monitoring wells in the sampling program. Sampling from the HGS wells would require an access
agreement.
Water levels should continue to be collected from all wells during sampling events, and potentiometric
surface maps should continue to be developed. However, as stated in Section 4.2.1, the water levels from
the operating wells should not be used when developing the potentiometric surfaces. Ideally,
piezometers would be located near the extraction wells to provide a representative water level for the
aquifer in those areas. Alternatively, the water levels from the extraction wells could be used if they are
adjusted for well losses and the interpretation accounts for the likelihood that the drawdown is likely
focused near the well (i.e., linear interpolation between the water level at the extraction well and other
monitoring points is not necessarily a reasonable assumption). For this site, it is the opinion of the RSE
team, that using corrected water levels from extraction wells is appropriate.
Sampling conducted in 2001 from the HGS wells, which are located on the 1070 Virginia Drive property,
indicate that site-related contamination has migrated offsite. However, it cannot be determined from
these limited data if the contamination detected in these wells migrated offsite before or after
implementation of the P&T system. If it has migrated offsite while the P&T system has operated, capture
is incomplete and additional pumping might be required prevent the plume from growing. The RSE
team, however, believes that the contamination likely migrated offsite prior to system operation. To
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monitor this offsite contamination and confirm that additional contamination is not migrating offsite, the
RSE team recommends that sampling and gauging of the HGS wells be added to the Honeywell ground
water monitoring program. Because these wells are likely downgradient of the capture zone, the RSE
team expects that the TCE concentrations in the HGS wells will slowly decrease over time to background
concentrations. The contaminant transport history at the site provides an approximate indication of the
time to see a decrease in these wells. The TCE contamination at the site first occurred in 1986 at the
latest and the TCE concentration in HGS-1 was 270 ug/L in 2001 (15 years later). As a result, it may
take an additional 5 to 10 years to see a substantial decline in the TCE concentrations in HGS-1, HGS-2,
and HGS-3. If TCE concentrations consistently increase or do not consistently decrease over this time
period, it would indicate that the plume may be growing.
If the modified potentiometric surface maps do not provide sufficient resolution to evaluate capture to the
degree desired by the site team, and the concentrations in the HGS wells do not show a consistent
decrease in TCE concentration over the course of a 5 year period, the RSE team would recommend that
the site team establish a target capture zone, update the ground water flow model, and use the model to
evaluate capture with respect to the target capture zone. The target capture zone would be the area or
volume of the contaminant plume (as highlighted on a site map) that the site team agrees should be
contained by the P&T system. Updating the model would primarily involve calibrating it with respect to
water levels that are measured during the current pumping conditions. The cost of the initial update
might be $20,000, and the use of the model to evaluate capture might cost an additional $5,000. The
results of the simulations could be included in a progress report to minimize the additional cost of
reporting. The costs associated with the modeling are not included in Table 7-1 with the other RSE cost
estimates, because it is probable that the modeling work will not be necessary based on the updated
potentiometric surface maps and monitoring from the HGS wells.
6.1.4 CONSIDER INSTITUTIONAL CONTROLS
If deemed necessary based on future land use plans and ground water monitoring, institutional controls
(perhaps in the form of a notice) should be considered at the 1070 Virginia Drive property to notify the
current and future property owners of the VOC contaminated ground water. The RSE team estimates
that the cost of developing such institutional controls would be less than $5,000.
6.2 RECOMMENDATIONS TO REDUCE COSTS
6.2.1 CONSIDER REPLACING UVOX SYSTEM WITH AIR STRIPPER AND VAPOR PHASE GAC
The current treatment plant was designed to remove at least 12 pounds of contaminants per day, with an
influent concentration of 100,000 ug/L TCE. However, over the past five years it has only needed to
treat up to 1 pound per day and generally less than 0.5 pounds per day. As of October 2002, the mass
removal rate for TCE was approximately 0.4 pounds per day. Although UVOX might have been cost
effective at the design mass removal rate, air stripping with off-gas treatment would be more cost
effective given the current and expected conditions. Treatment with GAC only is another option, but
Honeywell is limited to using the existing building, and using a larger GAC vessel (that is more
economical to changeout) is not feasible. Therefore, air stripping with off-gas treatment is the only
option discussed here. A cost comparison for operating the UVOX system and an air stripping system is
provided on the following page.
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UVOX System
Item
Maintenance labor
Materials
bulbs, tubes, etc.
hydrogen peroxide
Electricity (assumes $0.10/kWh)
(30 KW for lamps)
Total
Annual Cost
$10,000*
$6,000
$4,500
$25,000
$45,500
Air Stripping with Off-gas Treatment
Item
Maintenance labor (cleaning trays annually)
Vapor GAC
(6 pounds per day at $5 per pound)**
Electricity (assumes $0.10/kWh)
(5 HP blower, 75% efficiency)
Total
Annual Cost
$2,000
$11,000
$4,500
$17,500
* estimated cost excluding system checks by facility staff
** assumes the following mass loading rates and GAC efficiencies
0.39 Ibs/day TCE with 8% GAC efficiency = 4.875 Ibs/day
0.003 Ibs/day DCE with 0.5% GAC efficiency= 0.6 Ibs/day
Replacing the UVOX system with an air stripper and off-gas treatment would require capital expenses.
A tray stripper, 5 HP blower, and 1,000-pound vapor GAC unit could be purchased and installed in the
same treatment building for under $100,000. The liquid phase GAC could be left in place as a polishing
step but could be removed in the future if the stripper consistently meets the discharge criteria. Given the
above comparison, the capital expenses would be recovered in approximately 4 years (without
discounting) and savings would be realized in future years. A present-worth cost analysis of this
recommendation is provided in Table 7-1 at the end of this report. If influent concentrations and mass
loading to the treatment system decreases, the UVOX costs would remain similar but the costs for air
stripping with off-gas treatment would decrease because less vapor phase carbon will be required.
Therefore, cost savings would increase in the out years.
Replacing the UVOX system with an air stripper and off-gas treatment would be more cost-effective, but
implementing this recommendation has other advantages and disadvantages the site team might wish to
consider.
Advantages
Less downtime would be expected with the air stripper.
The air stripper could operate continuously and would not have low-flow shutdowns like the
UVOX system.
The lower energy consumption of the air stripper provides a hedge against potential future
increases in energy costs and provides a "greener" or more environmentally friendly remedy in
terms of energy consumption.
Disadvantages
Recovered contamination would not be destroyed on-site.
If additional pumping or mass removal is expected, the annual cost savings would decrease.
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In the RSE team's opinion, destroying contamination on-site does not generally provide a substantial
benefit, but the facility might have reasons for this preference. Additional pumping is discussed in
Section 6.4.1. Evaluation of the treatment system modifications should be postponed until after the
potential for additional pumping is evaluated. Given the current conditions and historical trends in RW-3
and MW-9D, P&T may continue at the site for decades. Therefore, replacing the system could be cost-
effective over the life-time of the remedy.
6.2.2 CONSIDER REVISIONS TO GROUND WATER MONITORING PROGRAM
Ground water is currently sampled and analyzed from 13 monitoring wells on a quarterly basis, two
monitoring wells on a semi-annual basis, and two extraction wells on a quarterly basis. In Section 6.1.2,
the RSE team suggested the site team consider installing two additional wells and adding them to the
monitoring program. Quarterly monitoring has demonstrated consistent results, and monitoring
associated with the remedy is expected to continue for many years, possibly decades. Therefore, the
RSE team suggests that decreases in the monitoring frequency be considered. In the opinion of the RSE
team, the following monitoring program is reasonable for demonstrating that site goals are being
achieved.
Semi-annual sampling and analysis from the following 11 wells should be sufficient for trend
analyses for evaluating capture to the southeast, south, southwest, west, and north/northwest:
MW-1, MW-7D, MW-17, MW-19, MW-20, MW-27, HGS-1, HGS-2, HGS-3, the proposed well
to the west, and the proposed well to the north.
MW-2D is theoretically below the aquiclude, however, historical data suggests it has TCE
concentrations that vary from undetectable to over 50 ug/L. Semi-annual sampling and trend
analysis of the concentrations from this well should help evaluate capture in the vertical or across
the bedding plane. If the concentrations fall below MCLs or shows a consistent decrease, then
capture is likely adequate.
The following wells appear to be used for the following purposes and can be sampled on an annual basis:
MW-8D and MW-16 are also pertinent for capture evaluation to the south, but TCE has not been
detected in either well; therefore, the sampling frequency at these locations could potentially be
reduced to annual.
MW-5, MW-28, and MW-26 are likely within the capture zone and therefore will not likely help
evaluate capture. Annual sampling should be sufficient to help document progress toward
cleanup.
MW-1D and MW-9D might also be in the capture zone and do not appear to be providing useful
information to evaluate capture. Therefore, annual sampling at these well should be sufficient to
track the progress of the remedy. It should be noted that a potential increase in the MW-1D
concentrations might be apparent in a trend analysis. A potential explanation for this is that
MW-1D is within the capture zone and that contaminated water, on its way to RW-3, is passing
byMW-lD.
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MW-25 has shown minimal and sporadic detections of TCE. It is screened below the primary
fracture zone screened by MW-9D and MW-27. If the northern recommended well is installed,
MW-25 could be removed from the monitoring program. If the northern recommended well is
not installed, MW-25 could remain in the sampling program with an annual sampling frequency.
Removing MW-25 from the monitoring program might be complicated due to its designation as a
compliance point.
MW-3D is a background well. It has effectively established a background condition, and does
not provide useful information with regard to evaluating capture or the progress toward cleanup.
It is, however, useful to determine background conditions. For these reasons, an annual sampling
frequency at this location should be sufficient.
The extraction wells, RW-3 and MW-4D, are known to have elevated VOC concentrations, and it
is likely that these concentrations will remain elevated for a number of years or even decades. As
a result, the sampling of the extraction wells RW-3 and MW-4D could also be reduced to annual.
The blended influent concentration at the treatment plant is monitored quarterly, so information
pertaining to the treatment plant performance would not be lost from reducing the monitoring
frequency in these two extraction wells.
The current ground water sampling program includes 15 wells sampled on a quarterly basis and two
wells sampled on a semi-annual basis, or a total of 64 samples per year. These suggested modifications
have the potential to reduce sampling to 11 wells on a semi-annual basis and 8 wells on an annual basis
for a total of 30 samples per year. The RSE team estimates that the current ground water monitoring
program costs (for labor and analysis) approximately $32,000 per year and that implementation of this
recommendation could save as much as 50% (i.e., $16,000 per year).
Process monitoring should continue quarterly.
6.3 MODIFICATIONS INTENDED FOR TECHNICAL IMPROVEMENT
6.3.1 USE HDPE FOR RW-3 DROP TUBE IF/WHEN IT REQUIRES REPLACEMENT
Given that the pump in RW-3 has failed five times, it might be worth using HDPE for the drop tube if the
current stainless steel drop tube requires replacement. HDPE is resistant to corrosion. It is also lighter
than stainless steel and will facilitate pump removal and maintenance. The cost of implementing this
recommendation is under $1,000.
6.4 CONSIDERATIONS FOR GAINING SITE CLOSE OUT
6.4.1 CONSIDER ALTERNATIVE REMEDIAL APPROACHES TO AUGMENT P&T SYSTEM
The persistent concentrations in MW-9D suggest that achieving MCLs in a reasonable time frame is
unlikely with the current remedy. Furthermore, the persistent contamination in this area might be the
cause of the lower but persistent concentrations in RW-3. Additional remedial efforts could be attempted
in the area of MW-9D to help determine if it is practicable to achieve MCLs. The RSE team envisions
two primary options for augmenting the existing P&T system: pumping from MW-9D or injecting agents
to enhance in-situ degradation. Implementing either or both of these options could potentially provide
one or more of the following benefits:
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shorten the operating life time of the P&T system, thereby reducing life-cycle costs
reduce concentrations to allow for monitored natural attenuation as a component of a modified
remedy
demonstrate the presence of a technical impracticability zone and limit the remedy goal for that
zone to containment rather than restoration
It should be noted that substantial life-cycle costs savings will likely occur only if the duration of the
P&T system operation is decreased. If aggressive remediation at MW-9D reduces the influent
concentrations to the P&T system, less contaminant mass will need to be removed from the extracted
water, but the decrease in annual O&M costs would not be substantial.
Pumping from MW-9D
Pumping from MW-9D would utilize the existing treatment system and would target mass removal at
MW-9D where concentrations have stabilized above 16,000 ug/L. It would also enhance hydraulic
capture of the contaminant plume, and more specifically, provide a degree of control for the source zone.
The treatment system and POTW permit has the capacity for an additional 5 gpm on average and the
1995 Aquifer Performance Test demonstrated that the yield at MW-9D is sufficient to provide this rate.
Consideration of replacing the UVOX system with the air stripper should be delayed until after this
recommendation is evaluated due to the potential for additional mass removal requirements. The UVOX
would be more appropriate for addressing the increased mass removal.
Converting MW-9D into an extraction well and piping the water to the treatment system would be
unusually expensive at this site due to the surface finish requirements and local labor costs. However,
piping from MW-9D could be connected with the 1.5-inch diameter piping between RW-3 and the
treatment plant to reduce trenching costs and to avoid trenching across the DeVry parking lot. The RW-3
piping could easily accommodate a combined flow rate of 10 gpm (5 gpm from RW-3 and 5 gpm from
MW-9D). Because MW-9D is located in front of the loading dock, work would likely need to be
coordinated with DeVry to avoid disruption to deliveries. The RSE team estimates the cost to install and
connect the well would be between $60,000 and $100,000. This cost assumes over $35,000 for the
wellhead-vault, pump, drop tube (HDPE), transducer, regrading, valving, and finishing the surface. It
also assumes 150 feet of trenching at $200 per foot with double-contained pipe, power, and control
cable/conduit.
Prior to proceeding with this approach, the site team might want to consider temporary pumping from
MW-9D to confirm the yield of MW-9D, to determine the expected mass removal rate, and to evaluate
the influence on pumping from RW-3. The 1995 Aquifer Pump Test demonstrated that a yield of 6 gpm
to 10 gpm is feasible. Sampling and analysis during this 1995 test also showed an increase in
concentration over the course of pumping. Conditions have changed after 5 years of an operating P&T
system; therefore, an additional test might be beneficial before installing a permanent system.
Pumping could consist of a pump test that is 48 hours in duration. Because MW-9D is located in front of
the loading dock, pumping would likely need to be coordinated with DeVry to avoid disruption to
deliveries. For example, pumping could be accomplished on the weekend in which 10,000 to 15,000
gallons of ground water is extracted from MW-9D and treated with the UVOX system. The site team
might determine the optimal approach for this temporary pumping and treating. It might involve
establishing a temporary line from the extraction well to the treatment system equalization tank or it
might involve pumping water to a temporary tank and then transferring the contents of the tank to the
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treatment system equalization tank at a prescribed rate. Because of the high expected TCE
concentrations in the extracted water, if a temporary line is set up directly from the extraction well to the
treatment system, steps should be taken to ensure any leaks would be properly contained. For reference,
at an extraction rate of 5 gpm, 10,000 gallons could be extracted in less than 35 hours. Also for
reference, the treatment system has up to 5 gpm of additional capacity, so treatment of 10,000 gallons
could be accomplished in 35 hours. Multiple events could be conducted to more accurately represent
extended pumping, but the cost of the pilot should be kept small relative to the cost of installing and
connecting the well. Sampling and analysis at MW-9D before and after each event would reveal whether
or not concentrations were increasing, decreasing, or remaining unchanged. Potential concentration and
water level changes in RW-3 could also be monitored.
Prior to implementing this pilot test, specific conditions should be set by the site team to help evaluate
the appropriate course of action. Possible courses of action might include the following:
installing an extraction well at MW-9D to allow permanent and continuous pumping for both
mass removal and source control
conducting quarterly pump events (similar to those noted above) for mass removal for a
predetermined amount of time or until a specific set of conditions is achieved
no additional pumping at MW-9D in favor of an alternative approach to remediation
If the site team opts for conducting a pump test, it would need to determine the appropriate conditions
and courses of action to be taken based on the results. The RSE team estimates that each pumping event
could cost $10,000 but would depend on the test protocols. Planning, interpreting, and reporting the
pump test could cost an additional $10,000. Therefore, the pilot program might cost $20,000 or more.
This cost for a test should be weighed against the cost of installing and connecting the well.
Injection for Enhanced In-Situ Degradation
This approach has the added advantage that remediation occurs underground with limited involvement or
disturbance to surface activities. This is particularly applicable to this site where the responsible party
does not own property and current tenants have ongoing activities near MW-9D. However, this approach
does not enhance plume capture or provide hydraulic control of the source area. The RSE team suggests
two potential options for enhancing in-situ degradation: bioaugmentation and nano-scale zero-valent iron
injection. The two options are discussed below.
Bioaugmentation
Bioaugmentation refers to the injection of both nutrients and microorganisms to enhance the in-situ
degradation of site contaminants. In some cases, bioaugmentation simply supplies the nutrients for an
existing population of microorganisms, and in other cases, biougmentation supplies both the nutrients
and microorganism cultures. Because specific microbe populations can be introduced, degradation from
TCE to harmless products (i.e., ethene) is possible in locations where natural degradation generally leads
to only DCE or vinyl chloride. Bioaugmentation has shown the ability to reduce concentrations to below
MCLs by degrading TCE to ethene. The microbes are also rather robust and have been shown to survive
in ground water with dissolved concentrations that are indicative of DNAPL.
The first step in assessing bioaugmentation is a technical evaluation of site-specific conditions including
hydrogeology and geochemistry. The potential to create a reducing environment is evaluated and the
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expected radius of influence of potential injection points is estimated. The RSE team estimates the cost
for this step at $1,5 00.
The second step is to conduct laboratory genetic analyses and bench testing. Ground water is analyzed to
determine the presence of halorespiring bacteria using genetic tests, to determine which microbes (if any)
need to be introduced to the subsurface, and to estimate the amount of nutrients that would be required to
maintain the reducing environment. The RSE team estimates the cost for this step at $2,500 to $5,000.
The third step is a field test. For this facility, the field test might include injecting microbes and nutrients
into MW-9D and monitoring changes in concentrations in MW-5, MW-9D, MW-27, and RW-3 over a
period of three to six months and possibly longer to determine the potential for rebound. The RSE team
estimates the cost for this step at $50,000 to $100,000.
As with other technologies, specific criteria to evaluate the success of bioaugmentation should be
established prior to the test. Hypothetical outcomes of the test might include the following:
If degradation is still occurring at or above a pre-determined acceptable rate, continue nutrient
injection in MW-9D for an additional 6 months to maintain the existing microbe population and
further enhance degradation. Reevaluate success of bioaugmentation relative to expectations
after this additional 6 months. Consider conducting bioaugmentation at other injection points.
If degradation occurs, but is below a pre-determined acceptable rate, consider one to two
adjustments that can be made to further enhance the process. Retest for another six months and
reevaluate.
If degradation occurs well be low a pre-determined acceptable rate, discontinue bioaugmentation
in favor of another remedial approach or potentially technical impracticabilty.
Other pre-set conditions and courses of action might be established to account for contaminant rebound,
in case it occurs. Other than the reduction in TCE concentrations, other factors to consider in evaluating
the success or failure of a pilot test might include the estimated cost of full-scale application and the
potential for fouling of the P&T system.
Nano-Scale Zero-Valent Iron
The facility is already familiar with this technology, which involves the injection of zero-valent iron
powder, carried by nitrogen gas, into the subsurface. The corrosion of the zero-valent iron to ferrous iron
yields hydrogen gas that then combines with a chlorinated compound and results in the dechlorination of
the contaminant. This technology is marketed by ARS Technologies under
the trade name FEROX. Other vendors might be available but could not be located by the RSE team.
Bedrock applications are considered ideal for this application because the iron can be injected efficiently.
A typical radius of influence in bedrock might be 20 to 40 feet. Implementing this technology would
likely be similar to implementing bioaugmentation. An evaluation, bench test, and pilot test are generally
recommended, and the RSE team recommends setting specific parameters and conditions to evaluate the
success of the pilot test. Example conditions are provided in the discussion on bioaugmentation. As with
bioaugmentation the potential for iron injection to foul the P&T system should be considered.
Based on discussions with ARS, the RSE team estimates that the cost for a pilot test of this technology at
the facility might range from $60,000 to $125,000.
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6.4.2 CONSIDER MODIFYING THE REMEDY
Following a pilot test for aggressive remediation at MW-9D, the RSE team recommends that the site
team consider modifying the remedy and/or remedy goals. The remedy goal currently states that
operation of the P&T system continue until MCLs are reached in the compliance wells. The results of
the pilot test will likely have one of the two following outcomes:
Reaching MCLs is practicable with a modified remedy
Reaching MCLs is technically impracticable
If the pilot test suggests that reaching MCLs is practicable, the remedy goal should likely be modified to
include the current P&T system and the additional remediation might occur at MW-9D (or other
locations). Consideration should also be given to including monitored natural attenuation (MNA) as a
component of the final remedy.
If the pilot test suggests that reaching MCLs is technically impracticable, the site team should consider
altering the remedy goals to containment in the area that is technically impracticable to restore but
continue to pursue aquifer restoration in the remaining portion of the aquifer. In this case, consideration
should be given to including MNA as a component of the final remedy, e.g., for the portion of the plume
amenable to MNA per EPA guidance.
6.5 SUGGESTED APPROACH TO IMPLEMENTATION
The RSE team places a higher priority on evaluating the recommendations in Section 6.1 relative to
evaluating the other recommendations. These recommendations are to further evaluate the potential for
vapor intrusion, to consider the installation of two monitoring wells, to modify the approach for
evaluating plume capture, and to consider institutional controls.
Recommendation 6.2.2 (consider modifications to the monitoring program) are given the next highest
priority by the RSE team, but could be done concurrently if they do not interfere with
considering/implementing the Section 6.1 recommendations.
The next level of priority could be reserved for consideration of alternative/supplemental remedial
technologies (6.4.1). Once these are evaluated, the site team can evaluate Recommendation 6.2.1
(consider replacing the UVOX system with air stripping and vapor phase GAC) and Recommendation
6.4.2 (consider modifying the remedy goal).
Recommendation 6.3.1, which entails replacing the RW-3 drop tube with HDPE, can be evaluated
if/when the tube or pump requires replacement.
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7.0 SUMMARY
The RSE team observed an extremely well-managed remedy. Honeywell, their contractors, and EPA all
have an excellent understanding of the site conditions, the remedy, and potential risks. Continuing efforts
have been made by the site team as a whole to improve system operation and protect human health and
the environment. 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 obvious
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. Recommendations for effectiveness include further evaluating the
potential for vapor intrusion, consideration of two additional monitoring wells, suggestions for improving
the capture zone analysis, and consideration of institutional controls. Recommendations for cost
reduction include considering modifying the treatment system to use air stripping instead of
UV/oxidation and optimizing the ground water monitoring program. Replacement of an extraction well
drop tube with HDPE (when/if necessary) is the only technical improvement recommendation.
Recommendations for site closeout consist of considering the use of alternative technologies to address
persistently elevated contaminant concentrations near MW-9D and modifying the remedy goals based on
the performance of the alternative technologies. When considering these alternative technologies and
potential pilot tests, the RSE team highly suggests developing specific criteria with which to evaluate the
success or failure of pilot tests.
Table 7-1 summarizes the costs and cost savings associated with each recommendation in Sections 6.1
through 6.4. Both capital and annual costs are presented. Also presented is the expected change in life-
cycle costs over a 30-year period for each recommendation both with discounting (i.e., net present value)
and without it.
33
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Table 7-1. Cost Summary Table
Recommendation
6. 1. 1 Further Evaluate
Potential for Vapor Intrusion
6.1.2 Consider the Installation
of Two Monitoring Wells
6. 1.3 Modify Approach to
Evaluating Plume Capture
6. 1.4 Consider Institutional
Controls
6.2.1 Consider Replacing
UVOX System with Air
Stripper and Vapor Phase
GAC
6.2.2 Consider Revisions to
Ground Water Monitoring
Program
6.3.1 Use HOPE for RW-3
Drop Tube if/when it Requires
Replacement
6.4.1 Consider Alternative
Remedial Approaches to
Augment P&T System
6.4.2 Consider Modifying the
Remedy
Reason
Effectiveness
Effectiveness
Effectiveness
Effectiveness
Cost
Reduction
Cost
Reduction
Technical
Improvement
Site Closeout
Site Closeout
Additional
Capital
Costs
($)
$10,000
$25,000
$0
$5,000
$100,000
$0
<$ 1,000
$54,000
to
$125,000
not provided
Estimated
Change in
Annual
Costs
($/yr)
$0
$03
$0
$0
($27,500)
($16,000)
$0
potential
savings4
not provided
Estimated
Change
In Life-cycle
Costs
(S)1
$10,000
$25,000
$0
$0
($725,000)
($480,000)
<$ 1,000
potential
savings4
not provided
Estimated
Change
In Life-cycle
Costs
($)2
$10,000
$25,000
$0
$0
($344,000)
($260,000)
<$ 1,000
potential
savings4
not provided
Costs in parentheses imply cost reductions.
1 assumes 30 years of operation with a discount rate of 0% (i.e., no discounting)
2 assumes 30 years of operation with a discount rate of 5% and no discounting in the first year
3 annual costs for monitoring these wells are considered in Recommendation 6.2.2.
4 potential savings might result from a decrease in mass loading to the treatment system or to a reduced remedy duration
34
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FIGURES
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FIGURE 1-1. THE HONEYWELL FACILITY, SURROUNDING AREA, AND LOCATION OF THE CROSS-SECTION SHOWN IN FIGURE 1-2
LEGEND
FORMER UST 8
PROPERTY LINE
^+ FENCE
G
CREEK
ELECTRICAL
DENOTES RESIDENTIAL
0 WELL SOMEWHERE
ON PROPERTY
WATER
TREATMENT
D:
\
A1
(V)
A
(Note: This figure is based on figures in site documents prepared by Harding Lawson Associates.)
-------
FIGURE 1-2. NORTHWEST/SOUTHEAST GEOLOGIC CROSS-SECTION AS DEPICTED IN FIGURE 1-1.
A
PINE RUN
CREEK
9
UNCONSOLIDATED MATERIAL
(SAND, CLAY & GRAVEL'
9 9
450
(Note: This figure is a re-creation of Figure 33 from the RCRA Facility Investigation Report, Harding Lawson Associates, December 1993. The cross-section
runs directly from the top to the bottom of the Figure 1-1 of this report along the southeastern edge of the main building.)
-------
FIGURE 1-3. EXTENT OF VOC CONTAMINATION BASED ON JULY 2002 SAMPLING EVENT.
O
D
LEGEN'D
WELLS NOT SAMPLED IN
2000 THROUGH 2002
MONITORING WELLS WITH
TOTAL VOC CONCENTRATIONS
EITHER BELOW 5 ug/L OR
ABOVE 5 ug/L BUT'BELOW
MCLs
MONITORING WELLS WITH
TOTAL VOC CONCENTRATIONS
BETWEEN 5 ug/L AND TOO ug/L
OR ANY ONE CONSTITUENT ABOVE
THE MCL BUT BELOW 100 ug/L
OPERATING RECOVERY WELL
WITH VOC CONCENTRATIONS
BETWEEN 100 ug/L AND
1,000 ug/L
OPERATING RECOVERY WELL
WITH VOC CONCENTRATIONS
ABOVE 1,000 ug/L
WELL NOT SAMPLED. IN 2002.
MOST RECENT SAMPLING DATA IS
USED TO GENERATE THIS FIGURE
FORMER UST 8
PROPERTY LINE
FENCE
CREEK
ELECTRICAL
SUBSTATION
DENOTES RESIDENTIAL
WELL SOMEWHERE
ON PROPERTY
MW-6A ,- .JMW-22/B4 -;|_lr_iT
PLAH1 MW-1
PZ-3
'.. I D
O
PZ-4
HGS-3*O
HGS-2* O
O MW~19
MW-20,-, HGS-1*
(MW-12* .MW-11
."W-2D M«N JWUWN!
-PZ=2MW-15* ll)Hl'
HI "i : ACLL i - mi
MW-21*
MW-SD
,,-,
- -'
'U
ftSHPALl
-7D
JO
MW-17
HOHLi /LLL
01 FICE r:f ' IL
MW-6D
j-i-ir I ':
MOM RESIDE!.!!',-'
GQUMEPiJ L N.ON-RESIDE!'*]All
SCALE IN FEET
(Note: Base feaUires taken from figures generated by Harding Lawson Associates. Sampling data obtained from July 2002 sampling event
unless otherwise noted.)
-------
FIGURE 4-1. POTENTIOMETRIC SURFACE MAP DEPICTING PRE-PUMPMG CONDITIONS (1993).
^
LEGEND
FORMER UST 8
PROPERTY LINE
FENCE
CREEK
ELECTRICAL
SUBSTATION
DENOTES RESIDENTIAL
WELL SOMEWHERE
ON PROPERTY
MIfQ -,ii
HILL h DAB
DQO
SCALE IN FEET
M1ULOWE
SL1BOR liSIOM
MW-5 ' MW-6A
88. 12 189.39
RW-2 ' - 1S8.28
\8827
., ,' '
j: ! PEN£|£JU
70 I 184.01 MW-21.
7SJ.S4
'' ",' ' ,:--
(Note: This figure is a re-creation of Figure 7 from the RCRA Facility Investigation. Harding Lawson Associates. December 1993.)
-------
FIGURE 4-2. POTENTIOMETRIC SURFACE MAP DEPICTING PUMPING CONDITIONS (1993).
^
LEGEND
0 FORMER UST 8
PROPERTY LINE
-- FENCE
- CREEK
ELECTRICAL
U SUBSTATION
DENOTES RESIDENTIAL
WELL SOMEWHERE
ON PROPERTY
MIfQ -,ii
HILL h DAB
DQO
SCALE IN FEET
a M Rl liAi , NSN-F " > MTK.
(Note: This figure is a re-creation of Figure 1 from 3rd Quarter Progress Report. Harding ESE. October 2002.)
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