EPA542-R-06-016
December 2006
www.epa.aov/tio
www.clu-in.org/optimization
REMEDIATION SYSTEM EVALUATION (RSE)
GCL TIE AND TREATING SUPERFUND SITE
SIDNEY, NEW YORK
Report of the Remediation System Evaluation
Site Visit Conducted July 13, 2006
Final Report
December 2006
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NOTICE
Work described herein was performed by GeoTrans, Inc. (GeoTrans) for the U.S. Environmental
Protection Agency (U.S. E.P.A). Work conducted by GeoTrans, including preparation of this report, was
performed under EPA contract 68-C-02-092 to Dynamac Corporation, Ada, Oklahoma. Mention of trade
names or commercial products does not constitute endorsement or recommendation for use.
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EXECUTIVE SUMMARY
A Remediation System Evaluation (RSE) involves a team of expert hydrogeologists and engineers,
independent of the site, conducting a third-party evaluation of site operations. It is a broad evaluation that
considers the goals of the remedy, site conceptual model, above-ground and subsurface performance, and
site closure strategy. The evaluation includes reviewing site documents, visiting the site for up to 1.5
days, and compiling a report that includes recommendations to improve the system. Recommendations
with cost and cost savings estimates are provided in the following four categories:
• Improvements in remedy effectiveness
• Reductions in operation and maintenance costs
• Technical improvements
• Gaining site closeout
The recommendations are intended to help the site team identify opportunities for improvements. In
many cases, further analysis of a recommendation, beyond that provided in this report, may be needed
prior to implementation of the recommendation. Note that the recommendations are based on an
independent evaluation by the RSE team, and represent the opinions of the RSE team. These
recommendations do not constitute requirements for future action, but rather are provided for the
consideration of all stakeholders.
The GCL Tie and Treating Superfund Site is located along the outskirts of Sidney in Delaware County,
New York. The site is a former wood treating facility that was operated between the early 1950s and
1988 when the property was abandoned by the owners. The site soils and ground water were impacted by
creosote-related compounds as a result of these historical activities. The site contamination has been
divided into two Operable Units (OUs). The OU1 remedy, which was completed in 2001, addressed
contaminated soils. The OU2 remedy addressed ground water contamination with a pump and treat
(P&T) system. This RSE focuses on the OU2 remedy, which is now completing the first year of a 10-
year Long-Term Remedial Action before being transferred to the State of New York for operation and
maintenance.
In general, the RSE team found a well-operated system. The observations and recommendations
contained in this report are not intended to imply a deficiency in the work of either the system designers
or operators, but are offered as constructive suggestions in the best interest of the EPA, the public, and the
facility. These recommendations have the benefit of being formulated based on operational data
unavailable to the original designers.
Recommendations are provided in three of the four of the categories: effectiveness, cost reduction, and
technical improvement. No recommendations are provided regarding site closure. The recommendations
for improving system effectiveness are as follows:
• A routine ground water monitoring program that consists primarily of annual sampling from site
monitoring wells should be established.
• An additional monitoring well could be added downgradient of MW-1 IB to horizontally
delineate the naphthalene plume in the bedrock aquifer. The plume is currently not delineated in
this area; however, the naphthalene concentrations at MW-1 IB are only a factor of two above the
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cleanup standard, and conservative transport modeling suggests that the contamination likely
degrades within a few hundred feet of MW-1 IB. Therefore, the additional monitoring well may
or may not be necessary depending on how rigorously EPA would like to demonstrate plume
delineation.
• The Five-Year Review suggested that soil vapor intrusion be evaluated for buildings in the area.
It is suggested that this evaluation begin with an investigation of shallow ground water in the
vicinity of the Meadwestvaco building.
Implementing these recommendations might require $50,000 in capital costs. The ground water
monitoring program suggested by the RSE team would cost less than the monitoring event conducted in
Spring 2006, and the savings associated with this suggested program are considered in the cost reduction
recommendations. Recommendations for cost reduction include the following:
• Historical ground water sampling in the intermediate (overburden) zone suggests that the plume
is stable without pumping from the overburden. Given that the overburden contributes high
levels of natural manganese that complicate operation of the treatment plant, the site team could
substantially simplify plant operations without sacrificing effectiveness by eliminating pumping
from the intermediate zone. The RSE team estimates that this change could save approximately
$104,000 in operator labor per year without any increase in capital costs.
• In addition to eliminating pumping from the intermediate zone, the site team could consider
automating the backwashing of the greensand filters. Approximately $28,000 per year might be
saved by implementing this recommendation, but implementation might cost as much as
$100,000 in capital costs. The incremental cost-effectiveness of this recommendation depends on
the cost savings realized by eliminating the extraction from the overburden.
• Suggestions are provided for a long-term ground water monitoring program so that monitoring
can be provided cost-effectively. The suggestions include competitive bidding of the ground
water sampling, reducing the number of wells sampled compared to the Spring 2006 event, and
contracting the ground water sampling directly through the U.S. Army Corps of Engineers.
Implementing these suggestions could save approximately $54,000 per year.
• The air stripper was included in the design because substantially higher concentrations of volatile
organic compounds (VOCs) were expected in the treatment plant influent. The liquid phase GAC
alone should be able to provide cost-effective removal of the low-level VOCs that are actually
present in the influent. A net savings of approximately $14,000 per year is expected if the air
stripper is bypassed.
• The current contract has negotiated fixed-price terms, and several of the items in this fixed-price
contract are uncertain. As a result, EPA is likely paying for items whether or not they are used.
It is suggested that future contracts consider a hybrid of time & materials (T&M) terms and fixed-
price terms so that EPA only pays for those materials that are needed rather than those materials
that the contractor estimates might be expected under reasonable worst case scenarios. This
change in contracting approach could likely save approximately $35,500 per year or more.
• Project management costs (including USAGE oversight) have been relatively high at this site, but
this is likely explained by the operational difficulties with the system. Once system operation is
streamlined the RSE team suggests reducing project management costs so that they are in line
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with other cost-effectively operated systems. This might result in a savings of approximately
$84,000 per year.
In total, the RSE team identifies approximately $319,500 per year in potential savings. The RSE team
also provides a recommendation for technical improvement based on the input from the plant operator.
The recommendation involves approximately $12,000 in modifications to the plant that include changing
the location of a high-high level switch and installing isolation valves on the sight glasses. No
recommendations are provided with regard to site closure, especially given that this is the first year of
long-term operation.
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 project conducted by the United States Environmental Protection
Agency Office of Superfund Remediation and Technology Innovation (U.S. EPA OSRTI) in support of
the "Action Plan for Ground Water Remedy Optimization" (OSWER 9283.1-25, August 25, 2004). The
objective of this project is to conduct Remediation System Evaluations (RSEs) at selected pump and treat
(P&T) systems that are jointly funded by EPA and the associated State agency. The project contacts are
as follows:
Organization
Key Contact
Contact Information
U.S. EPA Office of Superfund
Remediation and Technology
Innovation
(OSRTI)
Jennifer Hovis
2777 South Crystal Drive
5th Floor
Mail Code 5204P
Arlington, VA 22202
phone: 703-603-8888
hovis.jennifer@epa.gov
Dynamac Corporation
(Contractor to U.S. EPA)
Daniel F. Pope
Dynamac Corporation
3601 Oakridge Boulevard
Ada, OK 74820
phone: 580-436-5740
fax: 580-436-6496
dpope@dynamac.com
GeoTrans, Inc.
(Contractor to Dynamac)
Doug Sutton
GeoTrans, Inc.
2 Paragon Way
Freehold, NJ 07728
phone: 732-409-0344
fax: 732-409-3020
dsutton@geotransinc .com
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TABLE OF CONTENTS
NOTICE i
EXECUTIVE SUMMARY ii
PREFACE v
TABLE OF CONTENTS vi
1.0 INTRODUCTION 9
1.1 PURPOSE 9
1.2 TEAM COMPOSITION 10
1.3 DOCUMENTS REVIEWED 10
1.4 PERSONS CONTACTED 10
1.5 SITE LOCATION, HISTORY, AND CHARACTERISTICS 10
1.5.1 LOCATION 10
1.5.2 HISTORICAL PERSPECTIVE 11
1.5.3 POTENTIAL SOURCES 12
1.5.4 HYDROGEOLOGIC SETTING 12
1.5.5 POTENTIAL RECEPTORS 13
1.5.6 DESCRIPTION OF GROUND WATER PLUME 13
2.0 SYSTEM DESCRIPTION 15
2.1 SYSTEM OVERVIEW 15
2.2 EXTRACTION SYSTEM 15
2.3 TREATMENT SYSTEM 15
2.4 MONITORING PROGRAM 16
3.0 SYSTEM OBJECTIVES, PERFORMANCE, AND CLOSURE CRITERIA 17
3.1 CURRENT SYSTEM OBJECTIVES AND CLOSURE CRITERIA 17
3.2 TREATMENT PLANT OPERATION STANDARDS 18
4.0 FINDINGS AND OBSERVATIONS FROM THE RSE SITE VISIT 20
4.1 FINDINGS 20
4.2 SUBSURFACE PERFORMANCE AND RESPONSE 20
4.2.1 WATERLEVELS 20
4.2.2 CAPTURE ZONES 21
4.2.3 CONTAMINANT LEVELS 22
4.3 COMPONENT PERFORMANCE 23
4.3.1 EXTRACTION SYSTEM 23
4.3.2 NAPLPHASE SEPARATION 23
4.3.3 EQUALIZATION TANKS 23
4.3.4 GREENSAND FILTERS 23
4.3.5 BAG FILTERS 23
4.3.6 AIR STRIPPER AND VAPOR PHASE GAC UNITS 24
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4.3.7 LIQUID PHASE GAC UNITS 24
4.3.8 SOLIDS HANDLING 24
4.4 COMPONENTS OR PROCESSES THAT ACCOUNT FOR MAJORITY OF ANNUAL COSTS 24
4.4.1 UTILITIES 25
4.4.2 NON-UTILITY CONSUMABLES AND DISPOSAL COSTS 25
4.4.3 LABOR 25
4.4.4 CHEMICAL ANALYSIS 26
4.5 RECURRING PROBLEMS OR ISSUES 26
4.6 REGULATORY COMPLIANCE 26
4.7 TREATMENT PROCESS EXCURSIONS AND UPSETS, ACCIDENTAL CONTAMINANT/REAGENT
RELEASES 26
4.8 SAFETY RECORD 26
5.0 EFFECTIVENESS OF THE SYSTEM TO PROTECT HUMAN HEALTH AND THE
ENVIRONMENT 27
5.1 GROUND WATER 27
5.2 SURF ACE WATER 27
5.3 AIR 27
5.4 SOIL28
5.5 WETLANDS AND SEDIMENTS 28
6.0 RECOMMENDATIONS 29
6.1 RECOMMENDATIONS TO IMPROVE EFFECTIVENESS 29
6.1.1 INSTITUTE A ROUTINE GROUND WATER MONITORING PROGRAM 29
6.1.2 OPTIONAL PLUME DELINEATION 29
6.1.3 SOIL VAPOR INTRUSION EVALUATION 29
6.2 RECOMMENDATIONS TO REDUCE COSTS 30
6.2.1 DISCONTINUE PUMPING FROM THE INTERMEDIATE ZONE 30
6.2.2 CONSIDER MODIFICATIONS TO THE BACKWASHING AND SOLIDS HANDLING
PROCEDURES (CONTINGENT ON OUTCOME OF 6.2.1) 31
6.2.3 SUGGESTIONS FOR LONG-TERM GROUND WATER MONITORING 32
6.2.4 PILOT TEST BYPASSING THE AIR STRIPPER 34
6.2.5 CONSIDER A HYBRID TIME & MATERIAL s AND FIXED-PRICE CONTRACT 34
6.2.6 REDUCTIONS IN PROJECT MANAGEMENT CONSISTENT WITH STEADY STATE
SYSTEM OPERATION 35
6.3 RECOMMENDATIONS FOR TECHNICAL IMPROVEMENT 35
6.3.1 RE-LOCATE EQUALIZATION TANK HIGH-LEVEL SWITCH 35
6.3.2 DISCONTINUE USE AND SERVICE TO GENERATOR 35
6.3.3 MODIFY USE OF WATER LEVELS FROM OPERATING EXTRACTION WELLS WHEN
DEVELOPING PoTENTioMETRic SURFACE MAPS 36
6.4 CONSIDERATIONS FOR GAINING SITE CLOSE Our 36
7.0 SUMMARY 37
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Figures
Figure 1-1. Site Map with Well Locations
Appendices
Appendix A. BIOSCREEN Analysis
Appendix B. Calculation of Well Losses
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1.0 INTRODUCTION
1.1 PURPOSE
During fiscal years 2000 and 2001 Remediation System Evaluations (RSEs) were conducted at 20 Fund-
lead pump and treat (P&T) sites (i.e., those sites with 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 OSRTI has incorporated RSEs into a larger post-construction complete strategy for Fund-lead
remedies as documented in OSWER Directive No. 9283.1-25, Action Plan for Ground Water Remedy
Optimization. OSRTI has since commissioned RSEs at 10 additional Fund-lead sites with P&T systems.
An independent EPA contractor is conducting these RSEs, and representatives from EPA OSRTI are
participating as observers.
The RSE process was developed by the US Army Corps of Engineers (USAGE) and is documented on the
following website:
http://www.environmental.usace.army.mil/library/guide/rsechk/rsechk.html
An RSE involves a team of expert hydrogeologists and engineers, independent of the site, conducting a
third-party evaluation of site operations. It is a broad evaluation that considers the goals of the remedy,
site conceptual model, above-ground and subsurface performance, and site closure strategy. The
evaluation includes reviewing site documents, visiting the site for up to 1.5 days, and compiling a report
that includes recommendations to improve the system. Recommendations with cost and cost savings
estimates are provided in the following four categories:
• Improvements in remedy effectiveness
• Reductions in operation and maintenance costs
• Technical improvements
• Gaining site closeout
The recommendations are intended to help the site team (the responsible party and the regulators) identify
opportunities for improvements. In many cases, further analysis of a recommendation, beyond that
provided in this report, may be needed prior to implementation of the recommendation. Note that the
recommendations are based on an independent evaluation by the RSE team, and represent the opinions of
the RSE team. These recommendations do not constitute requirements for future action, but rather are
provided for the consideration of all site stakeholders.
The GCL Tie and Treating Superfund Site (the Site) was selected by EPA OSRTI based on a
recommendation from EPA Region 2. In particular, the treatment system has required more attention
than originally planned, and the site team is looking for cost-reduction strategies that will allow the
system to more cost-effectively maintain its designed level of protectiveness. This report provides a brief
background on the site and current operations, a summary of observations made during a site visit, and
recommendations regarding the remedial approach. The cost impacts of the recommendations are also
discussed.
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1.2 TEAM COMPOSITION
The team conducting the RSE consisted of the following individuals:
Peter Rich, Civil and Environmental Engineer, GeoTrans, Inc.
Doug Sutton, Water Resources Engineer, GeoTrans, Inc.
The RSE team was also accompanied by the following observers:
Sherri Clark from EPA OSRTI
1.3 DOCUMENTS REVIEWED
Author
U.S. EPA
U.S. EPA
U.S. EPA
COM
COM
COM
Conti
Conti
Carbonair
Conti
Various
Date
3/1995
9/2003
4/2005
7/2001
7/2006
10/2001
1/2006 - present
6-7/2006
2004
1 1/2005
Various
Title
Record of Decision
Five-Year Review Report
Remedial Action Report
Pre-Design Investigation Report
Ground Water Sampling Report, Spring 2006
Final Design Package
Treatment plant monthly process sampling results
Weekly O&M Reports, 6/12/2006, 6/19/2006,
6/26/2006, and 7/03/2006
Relevant Sections of Treatment Plan O&M Manual
Negotiated contract
Various site maps and historical data
1.4 PERSONS CONTACTED
The following individuals associated with the site were present for the visit:
Monica Baussan, Remedial Project Manager, EPA Region 2
Rob Alvey, Hydrogeologist and Regional Optimization Liaison, EPA Region 2
Ed Modica, Hydrogeologist, EPA Region 2
Gary Morin, Project Manager, U.S. Army Corps of Engineers
Darrell Moore, Engineer, U.S. Army Corps of Engineers
Ray Smith, Project Manager, Conti Environment and Infrastructure
Rick Vogel, Plant Operator, Conti Environment and Infrastructure
1.5 SITE LOCATION, HISTORY, AND CHARACTERISTICS
1.5.1 LOCATION
The GCL Tie and Treating Superfund Site is a 26-acre site located in a commercial/industrial section of
the Village of Sidney, Delaware County, New York. The site is bordered to the north by a rail line owned
by the Delaware and Hudson Railroad. Meadwestvaco, Inc., a calendar manufacturer, and the Sidney
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Municipal Airport are located to the north of the rail line. Unalam, Inc., a laminated wood manufacturer,
is located east of the property and Delaware Avenue runs along the southern border of the site in a
northeast to southwest direction. An undeveloped scrub/shrub area with wetlands lies west of the site.
Historically, the Site has been considered to be approximately 60 acres of land comprised of the GCL
property (26 acres) and two adjacent properties to the east (34 acres), referred to as the non-GCL
property. The two properties to the east are now a vacated sawmill operation and Unalam. For the
purpose of this RSE report, the Site refers to the 26-acre GCL property unless otherwise noted.
Site characterization and remediation has been divided into two operable units (OUs): OU1 to address
contaminated soils and OU2 to address remaining contaminated soils (if any) and contaminated ground
water. The OU1 remedy was completed in August 2000 (six years prior to the RSE), and successfully
addressed the soil contamination such that no soil contamination needs to be addressed as part of OU2.
This RSE focuses on the OU2 ground water remedy, which consists of an operating P&T system and
associated monitoring. A site map with well locations is provided on Figure 1-1.
1.5.2 HISTORICAL PERSPECTIVE
The GCL property was operated as a railroad tie manufacturing and treating plant since at least the early
1950s. The business was sold to GCL Tie and Treating in 1983. The owners filed for bankruptcy in 1987
and abandoned the property in 1988. During operation, logs were brought on-site, cut, and treated with
creosote in pressurized tanks inside the process building. After treatment, the logs were allowed to drip
dry in open areas west and east of the process building with no containment. In addition to this potential
source of contamination, one of the pressurized treatment vessels inside the process building
malfunctioned and released an estimated 9,000 to 10,000 gallons of creosote. The owners excavated
some of the contaminated soil and stored it on site for later disposal. However, only a small portion of
the contaminated soil was excavated.
• The site was proposed for inclusion on the National Priorities List in February 1994 and was
added in May 1994
• The OU1 Record of Decision was issued in 1994
• The OU2 Record of Decision was issued in 1995
• The OU1 Remedial Design was completed in 1997
• The OU1 Remedial Action was completed in 2000
• The OU2 Remedial Design was completed in 2001
• The construction of the OU2 P&T system began in 2002 and was completed in July 2004.
• The OU2 remedy operated for several months beginning in August 2004 before it was
temporarily shut down due to lack of funding and negotiations of the State Superfund Contract.
• Long-Term Remedial Action (LTRA) officially beginning in October 2005.
• The system was restarted in January 2006.
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1.5.3 POTENTIAL SOURCES
OUl addressed contaminated unsaturated soil, but creosote-related contamination persists in the saturated
zone as soil contamination, dense non-aqueous phase liquid (DNAPL), and as dissolved ground water
contamination. DNAPL has been observed as free product in several monitoring wells; however, the
DNAPL contamination is apparently relatively discontinuous with relatively isolated areas of both free
product and residual product. The soil contamination and DNAPL contamination provide an ongoing
source of ground water contamination. Primary site-related compounds of concern are as follows:
• benzene, toluene, ethylbenzene and xylenes (collectively BTEX)
• naphthalene
• 2-methyl-naphthalene
• other polyaromatic hydrocarbons (PAHs)
Volatile organic compounds (VOCs) attributed to other contaminated sites (the Route 8 Landfill and the
Hill Site upgradient of the GCL Site) are also present in ground water underlying the Site. The Route 8
Landfill Site is located across Delaware Avenue near the intersection of Route 8 and Delaware Avenue,
and the ground water remedy at that site includes P&T with extraction from the Unalam well, an on-site
recovery well, and an on-site recovery trench. Contaminants associated with the Route 8 Landfill Site
include toluene; ethylbenzene; 1,1-dichloroethane (1,1-DCA); trans-1,2-dichloroethene (trans-1,2-DCE);
trichloroethene (TCE); vinyl chloride; and 1,1,1-trichloroethane (1,1,1-TCA). The Hill Site is located
across Route 8 from the GCL Tie and Treating Superfund Site approximately 1,400 feet south of the
Route 8 Landfill Site. The contaminants associated with the Hill Site include TCE, 1,2-DCE, and 1,1-
DCA. The Hill Site has been capped and closed under the oversight of U.S. EPA.
1.5.4 HYDROGEOLOGIC SETTING
The Site is underlain by fill, some of which is associated with the original property use and some of
which is associated with the OUl remediation. In some areas of the site the fill is approximately 2 to 3
feet thick. In other portions of the site the thickness of the fill is approximately 20 feet deep.
Underlying the fill are glacial sediments that are mainly silts with variable proportions of clay and sand.
The sediments are poorly sorted. Clay lenses approximately 4 to 6 inches in thickness are common
throughout the sediments as are sand and gravel lenses. Thicker clay units (up to 25 feet thick) are also
present. These thicker units are also discontinuous and limited in horizontal extent. There is a general
coarsening of sediments downward in some locations. The sediments range from 0 to 125 feet in
thickness. The shallow monitoring wells at the site screen perched water in the upper portion of these
glacial sediments. The intermediate monitoring and extraction wells at the site screen regional ground
water in the middle or lower portion of these sediments, which is referred to as the "intermediate zone" in
this report.
Underlying the glacial sediments is glacial till that is primarily sand and gravel in a dense and
occasionally dry clayey matrix. The till ranges from 0 to 35 feet in thickness.
Bedrock from the Devonian Oneonta Formation underlies the glacial sediments. The formation is
comprised of medium to fine grained sandstones and interbedded mudstones. The bedrock surface slopes
to the northwest in the direction of the Susquehanna River. The bedrock surface is highly weathered and
significantly fractured in the upper 20 feet. The bedrock at MW-03B contains DNAPL at 30 to 40 feet
below the bedrock surface. The deep/bedrock monitoring and extraction wells at the site screen the upper
portion of the bedrock, which is referred to as the "deep zone" in this report.
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The depth to the regional water table is approximately 20 to 30 feet below ground surface (bgs), but
perched water is present in some locations at a depth of 5 to 10 feet bgs. In the absence of pumping, the
potentiometric surface prepared from measurements in the shallow wells depicts a convergence zone near
the MW-3 cluster suggesting that shallow (perched) ground water is migrating vertically to the regional
water table. Flow in the intermediate and deep zones indicates flow to the north or northwest toward the
Susquehanna River in the absence of pumping. The hydraulic gradient in the intermediate zone is
approximately 0.015 to 0.020 feet per foot, and the hydraulic gradient in the deep zone is approximately
0.010 feet per foot. Hydraulic conductivity has been calculated to be approximately 0.1 feet per day for
the intermediate zone and 0.5 feet per day for the deep zone based on pump tests conducted during the
pre-design phase.
1.5.5 POTENTIAL RECEPTORS
The primary receptors for the site are the Susquehanna River and two public water supply wells located
along the Susquehanna River. The supply wells are located approximately 4,500 feet north of the GCL
site and approximately 115 feet south of the southern bank of the river. The primary water supply well is
reportedly 100 feet deep, and the secondary water supply well is approximately 250 feet.
The 2003 Five Year Review states that the soil vapor intrusion exposure pathway was evaluated. The
maximum detected concentrations for several VOCs (including those not associated with the site) were
found to exceed the most protective screening level of a 10"6 incremental cancer risk or a non-cancer
hazard factor of 0.1. The Five Year Review suggested that additional evaluation would likely be
necessary for the existing Meadwestvaco building or any other buildings that might be erected over the
plume.
1.5.6 DESCRIPTION OF GROUND WATER PLUME
The site team tracks concentrations and migration of BTEX, naphathelene, 2-methyl naphthalene, and the
sum of the remaining heavier PAHs (a total of 15 other PAHs with higher molecular weights than
naphthalene). Concentrations are highest in the area immediately downgradient of the original soil source
area. DNAPL has historically been identified in MW-3B, MW-7B, and MW-7D. The June 2004 baseline
sampling event provides information regarding contaminant transport after the soil contamination had
been addressed by the OU1 remedy but before the P&T system began operation. In the intermediate
zone, the June 2004 results indicated that concentrations above cleanup standards for all compounds had
remained within approximately 200 to 300 feet of the source area, indicating relatively little potential for
migration.
In the bedrock zone, the June 2004 sampling suggested that contaminant migration was more extensive.
BTEX concentrations above cleanup standards were detected in MW-1 IB, and naphthalene was found
above standards in MW-1 IB and MW-13B. The following table summarizes the sampling results for
MW-1 IB and MW-13B between March 2000 and December 2005. Note that December 2005 is also
indicative of pre-pumping concentrations because the system had previously only operated for several
months and that had occurred more than a year before the sampling event.
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Compound
Benzene
Toluene
Ethylbenzene
Xylenes
Naphthalene
2-methyl naphthalene
Sum of heavier PAHs4
ROD Cleanup
Standard
(ug/L)
5
5
5
52
50
50
505
MW-11B1
(ug/L)
Mar. 2000
ND<5.0
2J
ND<5.0
12
1303
ND<1.0
4.25
Jun. 2004
ND<1.0
3.7
5.9
12
5803
39
10.6
Dec. 2005
ND<1.0
U
U
3
95
3.6
4.15J
MW-13B1
(ug/L)
Jun. 2004
1.3
ND <2.0
ND<2.0
ND<2.0
200
7.8
21.9
Dec. 2005
2.6
NIX 2.0
ND < 2.0
ND < 2.0
3.4
0.13
14.3J
Notes: Concentrations above standards are indicated in bold.
1 MW-11B is approximately 500 feet downgradient of a former source area, andMW-13B is approximately 600 to 700 feet
downgradient of a former source area.
The m+p-xylenes have a standard of 5 ug/L and o-xylenes have a standard of 5 ug/L butxylene sampling is reported as total
xylenes
3 The March 2000 naphthalene concentration is the average of two samples. The June 2004 naphthalene concentration is from
method 8270C rather than 8260B.
4 The sum of the concentrations for 15 other PAHs with molecular weights that are higher than naphthalene.
5 Each individual PAH in this category that has a standard has a standard of 50 ug/L.
With respect to vertical plume delineation, it appears that the bedrock monitoring wells intercept the
bottom of the local flow regime. Bedrock monitoring wells were generally drilled in 10-foot zones with
yield in each zone tested. The results routinely showed that the boreholes yielded little or no water below
the depth interval that was selected for long term sampling. Deeper portions of the boreholes were
backfilled and sealed before installing the screen for the monitoring interval.
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2.0 SYSTEM DESCRIPTION
2.1 SYSTEM OVERVIEW
The P&T system has an Operational and Functional date of October 2005 and consists of an extraction
system, a treatment plant, and discharge to a local creek. The system is designed to contain site-related
contamination and remove contaminant mass.
2.2 EXTRACTION SYSTEM
The extraction system includes four extraction wells in the intermediate zone and three extraction wells in
the deep (e.g., bedrock) zone. Each extraction well is piped independently to the treatment plant through
HOPE pipe. The following table summarizes the extraction rates and contaminant concentrations for
each of those wells based on sampling data collected between May 15, 2006 and May 17, 2006 and based
on flow rate measurements between July 3, 2006 and July 9, 2006.
Extraction Well
EW-1I
EW-2I
EW-3I
EW-4I
EW-1B
EW-2B
EW-4B
Total
Flow Rate
(gpm)
1.4
11.8
3.2
2.1
14.4
13.3
31.5
-78
BTEX
Concentration
(ug/L)
158
64
5
93
18
48
4
Naphthalene
Concentration
(ug/L)
570
220
1.8
i "*
Jj
250
1000
110
Total BTEX and
Naphthalene Mass
Removal
(Ibs/year)
4.4
14.7
0.1
1.2
16.9
61.0
15.7
114.0
Note: Total BTEX and naphthalene mass removed from each extraction well is calculated by multiplying the flow
rate by the sum of the BTEX and naphthalene concentrations and then by several conversion factors to obtain mass
removed in pounds per year.
2.3 TREATMENT SYSTEM
The treatment system consists of the following treatment components:
• 6,000-gallon DNAPL settling tank
• 150-gpm capacity coalescing oil/water separator
• 4,500-gallon equalization tank
• Potassium permanganate addition
• Two (2) green sand filters arranged in parallel using Carbonair MPC-13 tanks
• Two (2) 50 micron bag filters arranged in parallel
• Sulphuric acid addition
• 6-tray Carbonair STAT 180 low profile air stripper with a 15-horsepower blower
• Two (2) 10 micron bag filters arranged in parallel
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• Two (2) 2,500-lb liquid phase granular activated carbon (GAC) units arranged in series
• 6,000 gallon effluent discharge tank
• Two (2) 2,000-lb vapor phase GAC units arranged in series to treat air stripper off-gas
• 12-kW electric in-line duct heater
• 3,000-gallon dirty backwash storage tank
• Associated gauges, meters, mixers, pumps, and controls
The system was designed to treat influent concentrations of organic compounds as summarized in the
following table:
Compound in Influent
Benzene
Toluene
Ethylbenzene
Xylenes
2-methyl naphthalene
Naphthalene
Other PAHs
Non site-related compounds
Total
Design Influent Concentration
(ug/L)
500
430
650
3000
850
8,800
1,978
2,819
19,027
2.4 MONITORING PROGRAM
Ground Water Monitoring
A regular ground water monitoring program has not been established for the site because most of the site
funding has been diverted to maintain operation of the P&T system. The most recent sampling event
occurred in May 2006 and consisted of sampling 19 monitoring wells, one piezometer, and eight
extraction wells (one not operating) for VOCs, PAHs, iron, and manganese. Wells were sampled using
low-flow sampling, and wells with NAPL were not sampled. Prior to sampling, the site team included a
list of contingency wells that could be sampled in place of those wells with NAPL so that a total of 20
wells would be sampled. Laboratory analyses are provided by an independent laboratory contracted
through Conti Environment and Infrastructure, the site contractor. Ground water elevations were
measured in 39 wells, including the seven extraction wells. The results of the event were summarized in a
concise report that provided potentiometric surface maps for the intermediate and deep zones and
contaminant concentration maps for both BTEX and PAHs (including naphthalene). The site team has
not decided on a time frame for the next sampling event.
Process Monitoring
Process monitoring is conducted on a monthly basis. Samples are collected for the blended plant influent,
between the two liquid phase GAC vessels, and for the plant effluent. Influent and effluent samples are
analyzed for 23 metals, hardness, biochemical oxygen demand, total dissolved solids, total suspended
solids, alkalinity, nitrogen, chloride, sulfate, VOCs, and PAHs. The sample from between the liquid
phase GAC units is analyzed for VOCs.
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3.0 SYSTEM OBJECTIVES, PERFORMANCE, AND
CLOSURE CRITERIA
3.1 CURRENT SYSTEM OBJECTIVES AND CLOSURE CRITERIA
The ROD stated the following language regarding the goals for the ground water remedy.
• Prevent public and biotic exposure to contaminant sources that present a significant threat.
• Reduce the concentrations of contaminants in the ground water to levels that are protective of
human health and the environment.
• Prevent further migration of ground water contamination.
The ROD further states the following:
The goal of the groundwater portion of the remedy is to restore groundwater to drinking water
quality. However, due to the characteristics of creosote (e.g., extremely viscous and difficult to
pump) and the complex hydrogeological setting, it is unlikely that this goal will be achieved
within a reasonable time frame for areas containing the creosote layer (e.g., shallow groundwater).
Current estimates of shallow groundwater remediation are on the order of several hundred years.
As such, it is likely that chemical-specific ARARs will be waived for those portions of the aquifer
based on the technical impracticability of achieving further contamination reduction within a
reasonable time frame. If groundwater restoration is not feasible or practical, the alternative may
then focus on containing the extent of groundwater contamination within the site boundaries.
Restoration of the groundwater outside of the DNAPL source areas (e.g., intermediate
groundwater) is likely to be feasible, since it is mostly contaminated with mobile organic
contaminants (e.g., benzene).
The ROD also suggested the potential use of natural attenuation or enhanced biodegradation to reduce
contaminant concentrations if cost-effective. The decision to implement this additional remedial
approach or to focus on containment instead of restoration would be made either during design or during
the LTRA period.
It is noted that DNAPL is actually observable in the bedrock and that residual DNAPL is likely also
present in the intermediate zone. Therefore, the RSE team assumes that the discussion related to technical
impracticability also extends to the intermediate and deep zones. It is also noted that DNAPL is present
both on the former GCL property (MW-3B) and off-property (e.g., MW-7B and MW-7D). Therefore, the
RSE team assumes efforts to contain ground water are based on the location of DNAPL rather than an
attempt to contain contamination within the GCL property boundaries.
The cleanup criteria established by the ROD for several site-related contaminants are summarized in the
following table.
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Contaminant of Concern
Benzene
Toluene
Ethylbenzene
m+p-Xylenes
o-Xylenes
Naphthalene
2-methyl naphthalene
Acenaphthylene
Fluorene
Fluoranthene
Benzo(a) anthracene
Chrysene
Benzo(b) fluoranthene
Cleanup Criteria
(ug/L)
5
5
5
5
5
50
50
50
50
50
50
50
50
3.2 TREATMENT PLANT OPERATION STANDARDS
Treated ground water is discharged to the stream alongside Delaware Avenue. The discharge is governed
by a National Pollutant Discharge Elimination System (NPDES) permit equivalent administered by the
NYSDEC. Selected discharge criteria are provided in the table on the following page.
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Constituent
Discharge Criteria
(ug/L)
VOCs
Benzene
Toluene
Ethylbenzene
Xylenes
1 , 1 -Dichloroethane
1 , 1 -Dichloroethene
Cis- 1 ,2 -D ichlorothene
Styrene
1,1,1 -Trichloroethane
Tricliloroethene
1 ,3 ,5-Trimethy Ibenzene
1,2,4-Triinethylbenzene
5
5
5
5
5
7
10
10
10
5
10
10
PAHs
Naphthalene
2 -methyl naphthalene
Acenaphthene
Anthracene
Benzo(a) anthracene
Benzo(a) pyrene
Benzo(b) fluoranthene
Benzo(k) fluoranthene
Chrysene
Fluoranthene
Fluorene
Indeno(l,2,3-cd) pyrene
Phenanthrene
Pyrene
13
4.7
5.3
3.8
0.05
0.09
0.2
0.2
0.2
10
4.8
0.4
5
4.6
Inorganics
Iron
Manganese
Total dissolved solids
300*
300*
500
* Iron and manganese each have a limit of 300 ug/L and a combined limit of 500 ug/L
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4.0 FINDINGS AND OBSERVATIONS FROM THE
RSE SITE VISIT
4.1 FINDINGS
The observations provided below are not intended to imply a deficiency in the work of the system
designers, system operators, or site managers but are offered as constructive suggestions in the best
interest of the EPA and the public. These observations have the benefit of being formulated based upon
operational data unavailable to the original designers. Furthermore, it is likely that site conditions and
general knowledge of ground water remediation have changed overtime.
4.2 SUBSURFACE PERFORMANCE AND RESPONSE
4.2.1
WATER LEVELS
The potentiometric surface maps presented in the July 2006 Sampling Report include water levels from
operating extraction wells. Because water levels in operating extraction wells are affected by well losses
and other factors that substantially lower the water level in the well compared to the surrounding aquifer,
they may bias the development of potentiometric surface maps in favor of capture. As is the case at many
sites, there are not enough monitoring wells at the site to develop a reliable potentiometric surface map
that clearly indicates capture. However, several monitoring wells show significant reductions in water
levels from pumping. The following table provides the water levels expected based on a uniform gradient
under non-pumping conditions for several monitoring wells in the intermediate zone and their actual
water levels under continuous pumping conditions. This alone does not provide a basis for delineating
the actual capture zone, but as discussed the following section, the relatively substantial drawdown is an
additional line of evidence for capture that can be considered along with other analyses.
Monitoring Well
PZ-1I*
PZ-2I
EW-5I (not operational)
MW-3I
MW-12I
MW-07I
MW-08I
MW-11I
MW-10I
Expected Water Level
Without Pumping
(ft MSL)
986
-982
-982
-982
-980
-978
-977
-974
-974
Actual Water Level Under
Continuous Pumping
(ft MSL)
986.03
972.89
971.72
969.90
970.08
971.24
971.40
969.78
970.72
* PZ-1I is used as a reference point from which the other expected water levels are calculated based on a
presumed hydraulic gradient ofO. 017 feet per foot (e.g., consistent with the hydraulic gradient ofO. 015 to
0.020 feet per foot noted in Section 1.5.4).
As is evident from the above table, the pumping has a significant effect on the water levels in monitoring
wells. Similar effects from pumping are also identified in the deep zone.
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4.2.2 CAPTURE ZONES
Drawdown alone is not sufficient for interpreting a capture zone because the extent of capture is the result
of drawdown superimposed on the regional hydraulic gradient, and observable drawdown is commonly
present in wells that are downgradient of the capture zone. However, there are other lines of evidence
that suggest capture is adequate in both the intermediate and deep zones. For example, a capture zone
width calculation in both the intermediate and deep zones suggests that the capture zone might be several
times the plume width in each zone. The calculations are as follows:
Intermediate Zone
W - Width of capture zone - to be calculated
B - Saturated depth - assume 125 feet based on information in Section 1.5.4
K- Hydraulic conductivity - assume 0.1 feet per day based on information in Section 1.5.4
/' - Hydraulic gradient - 0.02 feet per day based on the upper limit noted in Section 1.5.4
/- Safety factor - 2 to account for heterogeneity and other factors
C - Conversion factor - 0.00518 gpm/ft3/day
Q - Intermediate zone well yield of approximately 18.5 gpm
w-
• 7,100 feet =
CxBxKxixf
18.5 gpm
0.00518gpm ,„_ O.lfeet 0.02feet „
&F x 125 feet x x x2
ft /day day foot
Deep Zone
W- Width of capture zone - to be calculated
B - Saturated depth -100 feet assuming upper portion of bedrock is targeted for capture
K- Hydraulic conductivity - assume 0.5 feet per day based on information in Section 1.5.4
/ - Hydraulic gradient - 0.01 feet per day based on information in Section 1.5.4
/- Safety factor - 2 to account for heterogeneity and other factors
C - Conversion factor - 0.00518 gpm/ft3/day
Q - Deep zone well yield of approximately 59.2 gpm
• 11,400 feet =
CxBxKxixf
59.2 gpm
0.00518 gpm innf 0.5 feet 0.01 feet „
——— x 100 feet x x x 2
ft /day day foot
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The plume widths in both zones are approximately 700 feet wide or less. Therefore, the above
calculations indicate that interpreted capture zone widths are approximately one order of magnitude
greater than the plume widths. Assuming the data used as input to these water budget calculations is
accurate, the current extraction rates result in a very conservative capture zone. These favorable
calculations coupled with the significant drawdown in monitoring wells as a result of pumping suggest
that capture is likely adequate. Such simple calculations require simplifying assumptions such as
homogeneous, isotropic, confined aquifer with infinite extent, uniform aquifer thickness, fully penetrating
wells, uniform regional horizontal hydraulic gradient, steady-state flow, negligible vertical gradient, no
net recharge, and no other water sources introduced to aquifer due to extraction. Most of the assumptions
are not satisfied at this site. However, based on the much greater calculated capture widths compared to
the actual plume widths, it appears that the analysis is conservative and error associated with the
assumptions would likely not change the conclusions.
Concentration for BTEX and naphthalene trends in downgradient wells can also provide useful
information regarding capture. Low or undetectable concentrations in the MW-10, MW-13, MW-14, and
MW-15 clusters suggest that contamination is not reaching these locations. If concentrations in these
wells continue to be low or undetectable, then this is supporting evidence that contaminants are either not
migrating in this direction or are adequately captured. On the other hand, the concentrations at MW-1 IB
have remained relatively consistent around 100 ug/L. The absence of a decrease in concentrations at this
well might be explained by one of the following:
• The monitoring well is near the stagnation point of the capture zone such that contamination in
this area is not migrating substantially away from or toward the extraction network.
• The monitoring well is within the capture zone such that contaminated water passes by MW-1 IB
on its way to one of the extraction wells (perhaps EW-4B).
• There is a gap in the capture zone that results in continued contaminant migration in this area.
EW-2B is directly upgradient of MW-1 IB and pumps at a rate of greater than 13 gpm. Using the capture
zone calculations presented earlier, this translates to an estimated capture width of approximately 2,600
feet. As a result, the RSE team believes that source area contamination is adequately contained and that
one of the first two possibilities noted above is the explanation for these relatively consistent
concentrations at MW-1 IB. Continued ground water monitoring may help confirm adequate capture or
indicate potential deficiencies in the extraction network.
4.2.3 CONTAMINANT LEVELS
The contaminant concentrations in downgradient wells have generally decreased since 2000, with the
exception of MW-1 IB. However, concentrations in the source area remain elevated and NAPL is present
in multiple wells. These contaminant levels indicate potential to remediate the fringes of the plume but
also indicate that contamination in the source area is persistent and that restoration of this area might be
technically impracticable in a reasonable time frame with a P&T system. Continued ground water
monitoring will provide more information to evaluate this conceptual model.
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4.3 COMPONENT PERFORMANCE
4.3.1 EXTRACTION SYSTEM
The extraction wells have electric submersible pumps that pump water through separate HDPE pipes to a
common manifold inside the treatment plant. The submersible pumps are controlled by level sensors.
Each extraction well and 25 monitoring wells have pressure transducers to monitor changes in drawdown.
The pumps in the intermediate wells cycle on and off due to a well yield that is relatively low compared
to the pump capacity. The bedrock wells run continuously.
4.3.2 NAPL PHASE SEPARATION
NAPL phase separation is theoretically provided by a 6,000-gallon DNAPL tank and a 150-gpm capacity
coalescing oil/water separator (COWS). No DNAPL has been collected in the DNAPL tank and no
LNAPL has been collected in the COWS. However, some DNAPL has been collected in the COWS. The
plant operator changed the COWS media prior to restarting the plant in January 2006. Additional cleaning
may be appropriate on a regular basis, perhaps every six months.
4.3.3 EQUALIZATION TANKS
Equalization of flow is provided by a 4,500-gallon HDPE equalization tank with high and low level
controls to control pumping and a high-high level control that results in plant shut down if triggered. The
plant operator reports that the high-high level control and the high level control are too close to each other
(separated by only 3 inches), such that the high-high level control is needlessly triggered in several
instances when influent flow rates are temporarily higher than the process flow rates.
4.3.4 GREENSAND FILTERS
The greensand filters are comprised of two Carbonair MPC-13 tanks with greensand and other media
arranged in parallel. Each tank has a 4-foot diameter bed providing 12.5 square feet of area, equating to
an acceptable loading rate of approximately 3.2 gpm per square foot (e.g., up to 80 gpm divided by a total
of 25 square feet of area). The influent manganese concentration is approximately 1,500 mg/L, and the
influent iron concentration is approximately 0.1 mg/L. This should translate to a potassium permanganate
dosing of approximately 3 mg/L, but the actual dosing level is not known.
The filters are manually backwashed at least twice a day. The O&M manual suggests that backwashing
of each tank should occur for 20 minutes. A greensand backwash should typically expand the bed by
35% to 40%, and typically requires a backwashing loading rate of 10 to 12 gpm per square foot. These
flow rates translate to 3,000 gallons of backwash water per filter; however, the tank that receives the
backwash from the filters only has a 3,000-gallon capacity. Therefore, both filters cannot receive a
complete backwash during one event. The plant operator chooses either to backwash each filter for half
the specified time or backwashes one filter at a time (which would require four separate backwashing
events per day). Greensand filter backwashing and the associated solids handling contributes
substantially to operator level of effort.
4.3.5 BAG FILTERS
Bag filters are provided in three locations. The plant was originally designed with bag filters between the
greensand filters and air stripper and then again between the air stripper and GAC units. The site team
has determined that 50 micron bag filters are most appropriate for the first set of bag filters and 10 micron
23
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bag filters are most appropriate for the second set. Since operation resumed in January 2006, the site
team added a set of 50 micron bag filters between the dirty backwash tank and the equalization tank.
Prior to adding this set of filters, filter changeouts on the original two units were required multiple times
per day. Since adding this set of filters, filter changeouts in the original two units are typically required
once a week. The new set of bag filters requires changeouts once every two to three days.
4.3.6
AIR STRIPPER AND VAPOR PHASE GAC UNITS
The six-tray Carbonair STAT 180 low-profile air stripper was included in the design because
concentrations of VOCs were anticipated at over 7,000 ug/L. The actual VOC influent, however, is under
500 ug/L (including naphthalene), and continued operation of the air stripper is not a cost-effective means
of treating the VOCs.
4.3.7
LIQUID PHASE GAC UNITS
There are two Carbonair MFC 20 liquid phase GAC adsorbers arranged in series. Each unit has 2,500
pounds of GAC. Neither unit has been changed since the plant began operating. Sampling is conducted
monthly between the two units to detect breakthrough. The GAC is manually backwashed monthly based
on the differential pressure. Backwashing the units takes approximately 15 to 20 minutes.
4.3.8
SOLIDS HANDLING
The solids handling procedures for the plant are labor intensive. For each backwash event, the operator
lets the solids in the backwash water settle, decants cleaner water to the equalization tank, empties the
solids into a 250-gallon tote, lets solids settle in the tote, and decants from the tote. When the tote is filled
(with about 1 to 2% solids) the solids are removed by a vacuum truck and sent off-site for disposal.
Disposal of 250 gallons occurs approximately once every three months. The process is relatively slow
such that given the frequent backwashes, the plant operator is continually conducting backwashes and
dealing with the associated solids.
4.4 COMPONENTS OR PROCESSES THAT ACCOUNT FOR MAJORITY OF
ANNUAL COSTS
The site has an annual budget of $700,000 per year as summarized below.
Item Description
Labor: USAGE oversight and project management
Labor: Contractor project management and travel
Labor: System operation (1.5+ full time equivalents)
Ground water sampling and reporting
Utilities: Electricity
Non-electric utilities and other services
Non-utility consumables, disposal, and small repairs
Treatment plant analytical costs
Ground water sampling analytical
Total Estimated Annual Cost
Estimated Annual Cost*
$60,000
$96,000
$209,000
$109,000
$57,000
$20,000
$105,000
$28,000
$12,000
$696,000
* extrapolated from negotiated proposal for 3 months of operation during 2006
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Historically, the site team has eliminated ground water sampling events to preserve funding to keep the
plant operating. Actual and projected expenditures for the limited ground water sampling in December
2005, the comprehensive ground water sampling event May 2006, and the nine months of operation from
January 2006 through the end of September 2006 are approximately $606,000. All contractor costs are
under a negotiated fixed-price contract. The remaining $94,000 for this time period is available to cover
oversight for USAGE or other issues that arise. O&M costs will need to decrease in the future if the site
team is to operate the system for a full year under the $700,000 annual budget. The RPM has filed a
request to increase the budget to $900,000 per year over a five year period.
4.4.1 UTILITIES
Utilities costs are divided between electricity and non-electricity services. The electricity cost from the
utility is estimated by the site contractor as $48,000 per year. An additional $9,000 per year consists of
the contractor's G&A and profit. GeoTrans estimates that the fixed-price of $48,000 per year reasonably
represents the costs for site electric; however, the negotiated cost was only based on a three month period.
If a contract were to be negotiated for a longer term, the escalation in electric costs would be difficult to
estimate, and the contractor will likely increase their bid to cover the risk of escalation.
Non-electric utilities and other services include potable water, garbage collection, cell phones, telephone,
portable toilets, cable internet service, and shipping. The direct costs for these non-electric utilities are
approximately $17,000 per year. An additional $3,000 per year represents site contractor G&A and
profit.
4.4.2 NON-UTILITY CONSUMABLES AND DISPOSAL COSTS
For a flow rate of 70 gpm, the contractor estimates a direct cost of $7,400 per month for consumables,
disposal, and small repairs. This translates to a direct cost of $88,800 per year. Including markups, the
cost for this category is $105,000 per year. The consumables category includes potassium permanganate,
sulfuric acid, bag filters, GAC, disposal of miscellaneous items, and disposal of solids. The site
contractor reports that the solids are treated as hazardous wastes due to the F027 listing associated with
wood treating facilities. The negotiated proposal indicated that the direct costs for GAC replacement and
disposal are $9,000 per event. Chemical usage was not reported to the RSE team, but it was described as
very low. The RSE team estimates that chemicals, bag filters, and solids disposal are likely under
$20,000 per year. Assuming the liquid GAC is changed twice per year and the estimated cost for other
items is correct, then this cost category should be closer to $38,000 per year in direct costs. Repairs may
also add to the cost, but the contract specifically states that the budget is limited to small repairs and that
motor replacements and similar items are not covered. The fixed-price of $88,800 per year likely
includes a significant hedge against material needs and costs. EPA is also paying for the G&A and profit
markups on the consumables cost, which totals approximately $16,000 per year.
4.4.3 LABOR
There are four general areas involving labor: USAGE oversight, contractor project management, operator
labor, and ground water sampling. The USAGE oversight of $60,000 is reasonable for this first year of
operation; however, in future years as O&M issues are resolved, it is likely that these costs will decrease
as a result of fewer technical issues, streamlined contract administration, and fewer site visits. The
contractor project management is approximately $84,000 per year plus $12,000 per year in travel costs.
The $84,000 per year includes approximately 1,120 hours of labor, which translates to over 0.5 full time
equivalent employees for managing site issues and vendors. While this may be appropriate during the
first six months to a year of operation, it is likely that these costs will decrease substantially over time,
particularly, since this project management category does not include any reporting. The operator labor is
25
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approximately $209,000 per year for just over 1.5 full time equivalent employees with the assumption
that response to an alarm is needed each night. The ground water sampling labor (and associated
equipment) is approximately $109,000 per year, of which $92,000 per year represents direct costs.
4.4.4 CHEMICAL ANALYSIS
The chemical analysis costs represent costs for analyzing treatment plant compliance samples, waste
characterization samples, and ground water monitoring samples. The unit rates provided in the negotiated
contract appear to be reasonable and competitive.
4.5 RECURRING PROBLEMS OR ISSUES
The site team reported that maintenance of the greensand filters and solids handling have been more labor
intensive than originally planned. The site team also reported the unnecessary alarms associated with the
close proximity of the high level switch and the high-high level switch in the equalization tank.
4.6 REGULATORY COMPLIANCE
The treatment plant has routinely met discharge standards since resuming operation in January 2006.
4.7 TREATMENT PROCESS EXCURSIONS AND UPSETS, ACCIDENTAL
CONTAMINANT/REAGENT RELEASES
There have been no reported major upsets or accidents since the plant resumed operation in January 2006.
4.8 SAFETY RECORD
The site team reports no health and safety reportable incidents for the treatment plant. The site team does
note the inconvenience and potential safety issues associated with one person performing some of the
tasks and the absence of a door directly between the office and treatment plant area.
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5.0 EFFECTIVENESS OF THE SYSTEM TO PROTECT HUMAN
HEALTH AND THE ENVIRONMENT
5.1 GROUND WATER
The ground water points of exposure are the supply wells located along the banks of the Susquehanna
River, approximately 4,000 feet downgradient of the site. Data to date suggest that the contamination is
far from reaching these wells. The naphthalene in MW-1 IB represents the most significant downgradient
migration of site-related contamination. Although this contamination may extend further, the properties
of naphthalene suggest it will degrade before reaching these supply wells. The naphthalene
concentrations in the source area have been as high as 1,600 ug/L, and NAPL has been observed at MW-
7B. Therefore, concentrations are an order of magnitude lower at MW-1 IB than in the source area.
Relatively simplistic contaminant fate and transport modeling performed by the RSE team using the
BIOSCREEN modeling package and conservative input values that reproduce this attenuation between
the source area and MW-1 IB confirms that contamination would attenuate below the standard of 50 ug/L
within 200 feet of MW-1 IB (see Appendix A). As a result, the RSE team believes that the current
remedy is likely protective of human health with respect to preventing contamination of the identified
public supply wells.
5.2 SURFACE WATER
The Susquehanna River is the primary ecological receptor of site-related ground water contamination.
The Susquehanna River is near the public supply wells. As stated above, conservative fate and transport
modeling suggests that the contamination at MW-1 IB above standards (e.g., naphthalene) would degrade
to below standards within 200 feet of MW-1 IB, which is several thousand feet from the River. As a
result, the RSE team believes that the current remedy is likely protective of human health and the
environment with respect to preventing contamination of the Susquehanna River.
5.3 AIR
The Five-Year Review for the site indicated that risks associated with soil vapor intrusion should be
evaluated at the site. Other than the treatment plant, the primary building of concern would be the large
industrial two-story building on the Meadwestvaco property to the north of the site. The depth to ground
water near the building is approximately 12 to 15 feet below ground surface. Concentrations of site-
related VOCs at MW-8I (approximately 55 feet deep) were not detectable in the 2006 sampling event.
Relatively high levels of site-related VOC contamination are present at MW-121, which is also near the
building, but no samples have been collected from a shallow well in this location (e.g., PZ-3) since 1998,
which is before the OU1 and OU2 remedies. The RSE team does not recommend indoor sampling for
this building due to its industrial nature. Rather, if the site team proceeds with an evaluation, the initial
steps should focus on water quality in the shallow ground water.
If the site team can demonstrate low (e.g., at or below standards) or undetectable VOC concentrations at
the water table, then this clean water overlying the contamination would eliminate the potential for VOCs
to enter the vadose zone and the indoor air space. If the site team wishes to proceed with this evaluation,
shallow ground water concentrations could be evaluated from grab samples taken from a direct push
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sampling event. Sampling PZ-3 and locating direct push samples between PZ-3 and the Meadwestvaco
building, the site team can also determine if contamination adjacent or beneath the building is attributable
to the GCL site. If the sampling suggests little or no VOC contamination in the shallow ground water on
the GCL side of the building, then any soil vapor contamination that might be detected in or beneath the
Meadwestvaco building could potentially derive from non-GCL-related sources. Therefore, before
proceeding with sub-slab sampling or other sampling associated with the Meadwestvaco building, the
RSE team suggests a limited shallow ground water investigation.
The site team could also consider modeling with conservative assumptions. As an industrial building,
there are several features that would limit the potential for vapor intrusion relative to private residences
(which are often the focus of vapor intrusion evaluations). With modeling, ventilation and building
construction should be considered. The ventilation rate for industrial buildings generally involves several
air exchanges per hour such that the VOC concentrations would generally not accumulate in indoor air as
they would in a residence where there is typically much less than one air exchange per hour. In addition,
it is possible that the building is maintained at a positive pressure relative to ambient air. Finally, the
building may not have working space below the ground surface (e.g., a basement).
5.4 SOIL
Surface soil and subsurface soil above the water table has been addressed as part of OU1. Potential routes
of exposure to contaminated soil have therefore been eliminated.
5.5 WETLANDS AND SEDIMENTS
As discussed above for ground water and surface water, the RSE team believes that the current remedy is
likely protective of human health and the environment with respect to the wetlands and sediments
associated with the Susquehanna River. The wetlands and sediments associated with the discharge point
are upgradient of the site. They are not impacted by the site but may be impacted by upgradient non-site-
related sources.
28
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6.0 RECOMMENDATIONS
Cost estimates provided herein have levels of certainty comparable to those done for CERCLA Feasibility
Studies (-30%/+50%), and these cost estimates have been prepared in a manner consistent with EPA 540-
R-00-002, A Guide to Developing and Documenting Cost Estimates During the Feasibility Study, July,
2000.
6.1 RECOMMENDATIONS TO IMPROVE EFFECTIVENESS
6.1.1 INSTITUTE A ROUTINE GROUND WATER MONITORING PROGRAM
The site team has previously reduced ground water monitoring efforts to preserve funding to keep the
system operating. The RSE team recommends that the site team institute a routine ground water
monitoring program that consists of annual sampling. The scope and costs of the recommended program
are discussed in Section 6.2.3 because the recommended scope and costs should result in substantial
savings relative to the ground water sampling conducted in 2006.
6.1.2 OPTIONAL PLUME DELINEATION
Naphthalene concentrations at MW-1 IB are above standards, and as a result, the plume is not fully
delineated in this area. However, the naphthalene concentrations at MW-1 IB are over an order of
magnitude lower than they are approximately 300 feet upgradient near the source area. Given this
attenuation and that naphthalene only exceeds the ROD cleanup standards by a factor of approximately
2.0, the RSE team believes it is reasonable to extrapolate the downgradient edge of the naphthalene plume
in this area. The RSE team believes that the naphthalene concentrations are likely below standards within
200 to 500 feet downgradient of MW-1 IB and that no further investigation is required. However, if the
site manager feels a need to provide more concrete evidence of plume delineation, an additional bedrock
well could be installed approximately 200 feet downgradient of MW-1 IB. The cost for this monitoring
well might be $35,000, including work plans, oversight, and one round of sampling in addition to the next
upcoming site-wide sampling event.
6.1.3 SOIL VAPOR INTRUSION EVALUATION
The Five-Year Review indicated the need to evaluate soil vapor intrusion for the site. The primary
building of interest is the Meadwestvaco building. The RSE team provides an initial approach for
evaluating the potential for soil vapor intrusion. The RSE team suggests evaluating shallow ground water
with ground water samples collected from PZ-3 and from a direct-push event. Given that most of the
contamination at the site is at depth, the previously executed soil remedy, and continued infiltration of
rain water, the RSE team believes that the water at the water table likely has undetectable or very low
concentrations of VOCs, effectively isolating the vadose zone from the deeper contamination. This type
of shallow ground water investigation could also be used to determine if there is a direct link between
shallow VOC contamination at the site, and immediately adjacent, to the Meadwestvaco building. If no
shallow VOC contamination is found in shallow groundwater adjacent to the Meadwestvaco building, the
RSE team would not advise further investigation of the indoor or sub-slab air at the Meadwestvaco
building due to the potential influence from other possible sources. The RSE team estimates the shallow
ground water evaluation could likely be conducted for $15,000, including work plans, sample collection,
analysis, and reporting.
29
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6.2 RECOMMENDATIONS TO REDUCE COSTS
6.2.1 DISCONTINUE PUMPING FROM THE INTERMEDIATE ZONE
Ground water sampling indicates that pumping for plume containment is not necessary' in the intermediate
zone. Although ground water data from March 2000 (during the OU1 remedy) indicated naphthalene and
BTEX contamination migrating beyond MW-8I at concentrations above ROD standards, concentrations
decreased substantially prior to P&T system operation in August 2004. Over this more than four year
period without pumping, naphthalene concentrations at MW-8I decreased from as high as 1,900 ug/L to
41 ug/L and benzene concentrations decreased from 12 ug/L to less than 1 ug/L. These decreases can
likely be attributed to the success of the OU1 remedy in removing source area contamination that was
migrating toward MW-8I and natural attenuation that occurred over the four year period following source
removal. In addition, sampling from other downgradient monitoring wells in June 2004 and December
2005 indicated either undetectable concentrations or concentrations far below standards for all
contaminants of concern.
The intermediate zone wells provide approximately 20% of the total system mass removal. Given the
presence of NAPL at the site (predominantly in the deep zone), the absence of pumping in the
intermediate zone would not appreciably delay aquifer restoration.
Although the intermediate zone pumping provides little benefit in terms of plume control and mass
removal, it contributes heavily to the annual costs for system operation because it provides the majority of
the manganese loading. The blended influent manganese concentration to the treatment plant is
approximately 1,530 ug/L at a flow rate of approximately 78 gpm. This translates to a daily load of 1.42
pounds of manganese per day.
78 gal 1,530 ug 1,440 min 3.785L
—— X — X X X-
kg 2.2 Ibs _ 1.42 Ibs
mm L day gal 10 ug kg day
The blended iron concentration and mass loading are approximately 100 ug/L and 0.1 pounds per day,
respectively. The intermediate zone extraction wells, which are screened in the overburden, have
significantly higher manganese concentrations than the bedrock wells. Therefore, if pumping can be
discontinued from the intermediate zone without sacrificing remedy protectiveness, the manganese
loading to the treatment plant can be reduced. The following table summarizes manganese data from
each of the intermediate zone extraction wells and bedrock zone extraction wells and calculates the mass
loading contributed by each well and from each zone.
Extraction Well
EW-1I
EW-2I
EW-3I
EW-4I
Intermediate Zone Subtotal
EW-1B
EW-2B
EW-4B
Bedrock Zone Subtotal
Total
Flow Rate
(gpm)
1.4
11.8
3.2
2.1
18.5
14.4
13.3
31.5
59.2
77.7
Manganese
Concentration*
(ug/L)
11.100
4,330
1,870
7,280
600
706
417
Manganese Mass
Loading
(Ibs/day)
0.19
0.61
0.07
0.18
1.05
0.10
0.11
0.16
0.37
1.42
* The higher value of the total and dissolved concentrations from the May 2006 sampling. Some of the dissolved
manganese values were higher than the total values, suggesting that the two values may have been swapped.
30
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As demonstrated in the above table, the mass loading of manganese can be reduced by approximately
1.05 pounds per day (or by approximately 74%). Because the backwash requirements are directly related
to solids removal, a reduction of 74% mass loading should substantially reduce the backwashing
requirements. It may be possible to reduce backwashing to three times per week, effectively reducing
operator labor from five to three days per week.
In addition, in the absence of extraction from the intermediate zone extraction wells, the blended
manganese influent concentration will be approximately 500 ug/L, which is much closer to the discharge
limit of 300 ug/L. The site team may be able to negotiate with the State to relax the manganese standard
to 600 ug/L, allowing the plant to operate without the greensand filters. If this is feasible, operator labor
could likely be reduced to one or two days per week because greensand backwashing and solids handling
would no longer be required.
If such a change to the discharge permit is not feasible, the site team should consider relaxing its internal
standards for manganese removal. At present, the site team is maintaining manganese concentrations
below 15 ug/L in the plant effluent. The site team could further reduce the need for backwashing by
either bypassing some flow around the greensand filters or by reducing the permanganate dosing such that
the manganese concentration in the plant effluent is approximately 200 ug/L (i.e., 100 ug/L below the
discharge criteria). The site team will need to confirm that the treatment plant can still meet the criteria
for total dissolved solids.
The RSE team recommends immediately discontinuing pumping from the intermediate zone wells on a
trial basis. Continued influent monitoring should show a significant decrease in manganese loading, and
after operating for several weeks at this decreased loading, the site team should notice a substantial
decrease in the need to backwash the greensand filters. With a reduction in the backwash frequency, the
site team could consider providing the recommended full 20-minute backwash for each unit.
There should be no additional engineering or treatment plant costs associated with discontinuing pumping
from the intermediate wells, and the RSE team estimates a potential reduction in operator labor from
approximately 60 hours per week to 30 hours per week (including response to alarms up to three times per
week). This would represent a decrease in operator labor costs from approximately $209,000 per year to
approximately $105,000 per year. If the site team is concerned about potential contaminant migration
that is occurring deeper than MW-8I but above the deep zone, the site team could consider installing
another monitoring well in the same location as MW-8I but approximately 30 feet deeper. The cost for
this well might be $15,000 (including work plans and oversight) if the well is the only well being
installed.
6.2.2 CONSIDER MODIFICATIONS TO THE BACKWASHING AND SOLIDS HANDLING
PROCEDURES (CONTINGENT ON OUTCOME OF 6.2.1)
Depending on the outcome of the above recommendation, the site team may consider additional measures
to reduce operator labor and other costs associated with backwashing and solids handling. The
investment in these additional measures depends on how much additional money may be saved after
Recommendation 6.2.1 is fully implemented. Potential measures to consider include the following:
• The site team could convert the existing DNAPL recovery tank (6,000 gallon capacity with a
cone-shaped bottom and bottom drain) into a supplementary dirty backwash tank. This would
involve bypassing the plant influent around the DNAPL recovery tank and directly into the
COWS. Since operation began, it has been the COWS, not the DNAPL recovery tank, that has
recovered DNAPL from the influent. The DNAPL recovery tank does not currently play any
31
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other beneficial role in the treatment plant. In addition, the DNAPL recovery tank has an
appropriate capacity and construction to serve as a dirty-backwash tank. This conversion would
allow the plant operator to provide both greensand filters a full 20-minute backwash per event. If,
after further evaluation, the site team does not believe the DNAPL recovery tank is appropriately
configured to serve as a dirty backwash tank, a second 3,000-gallon tank could be added for a
slightly higher cost. This modification should improve the performance of the greensand filters
and further reduce the backwash frequency without significantly increasing operator level of
effort. The cost for using the DNAPL recovery tank is plumbing labor, which should be less than
$2,500 in direct costs.
• The site team could also consider adding a small (about 2 cubic feet) filter press to the treatment
plant for solids handing and automating the backwashing function by adding control equipment
or replacing the vessels with a packaged automated system that can be tied into the main control
system. This would substantially reduce operator time for solids handling, and it would also
decrease disposal costs. The capital investment for this measure might be on the order of
$100,000 total, including approximately $40,000 for the filter press, compressor, air lines and
controls, double diaphragm sludge feed pump and filtrate piping to the equalization tank and
$60,000 for replacing or modifying the greensand filters to provide automated backwashing and
tying the controls into the main operating system. The site team will want to carefully evaluate
the potential additional cost savings of implementing this after Recommendation 6.2.1 is
implemented.
The RSE team estimates that both of these modifications will be cost-effective if the greensand filters
require an operator to be on site three or more times per week for backwashing and solids handling. This
will not be determined until after Recommendation 6.2.1 is implemented. The modifications should
reduce operator labor to approximately 22 hours per week (including response to three alarms per week),
which might further reduce operator labor costs from the $105,000 noted in Recommendation 6.2.1 to
approximately $77,000 (e.g., additional savings of approximately $28,000 per year).
6.2.3 SUGGESTIONS FOR LONG-TERM GROUND WATER MONITORING
The 2006 ground water monitoring event cost approximately $121,000 to sample 21 non-pumping wells
and 7 operating extraction wells, analyze the samples (iron, manganese, VOCs, and PAHs), and prepare a
report. The direct costs for this event were surprisingly high to the RSE team, and the RSE team believes
that much lower costs can be obtained by competitively bidding this ground water sampling or through
stronger negotiations between USAGE and the contractor. For example, the RSE team believes that a
reasonable/conservative direct cost for the ground water sampling itself should be approximately $30,000
rather than $65,000. USAGE should directly contract the ground water sampling to the appropriate
contractor to avoid the mark-up by the prime contractor. Although this will require some labor from
USAGE, the added cost should be substantially lower than the cost of the prime contractor's markup. The
costs and savings associated with these suggestions are summarized in the following table.
32
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Item
Sampling
Labor
Materials & Equipment
Travel
Project Management
Office Work
Work Plans
Data Management
Data Validation
Reporting
Analysis
Prime Contractor Oversight
Total
Reported
Direct Costs*
$65,400
$23,800
$9,900
$2,800
$101,900
Reported
Costs to EPA*
$77,200
$28,100
$11,700
$4,000
$121,000
RSE Team
Suggested Direct
Costs
$30,000
$23,800
$9,900
$3,000***
$66,700
RSE Team
Suggested Cost
to EPA**
$30,000
$23,800
$9,900
$3,000***
$66,700
* The difference between the direct costs and the costs to U.S. EPA is the markup from the site contractor of 18%
** Costs reflect USAGE directly contracting with the sampling firm
*** Costs reflect added time from USAGE (instead of the prime contractor) to manage the sampling contractor
The RSE team also suggests modifying the sampling program as follows to focus on demonstrating plume
containment:
• Annual monitoring of the following non-pumping wells in the intermediate zone: MW-7I, MW-
81, MW-10I, MW-1II, MW-13I, MW-14I, MW-15I, EW-1I, EW-2I, EW-5I, EW-4I. Note that
this assumes pumping in the intermediate zone has been discontinued. Samples should be
analyzed for VOCs and PAHs only (i.e., not iron or manganese).
• Annual monitoring of the following non-pumping wells in the deep zone: MW-10B, MW-1 IB,
MW-7D, MW-12B, MW-13B, MW-14B, MW-15B. Samples should be analyzed for VOCs and
PAHs only (i.e., not iron or manganese).
• Quarterly monitoring of the three operating extraction wells should be conducted with samples
analyzed for VOCs, PAHs, iron, and manganese. This sampling could be conducted by the
treatment plant operator from within the treatment plant, and samples could be submitted for
analysis along with other process water samples.
• Sampling select additional site monitoring wells every five years in conjunction with the Five-
Year Reviews.
The above changes should not result in a significant change in costs compared to the suggested costs in
the above table. Fewer non-pumping wells will be sampled and several iron and manganese samples will
not be collected and/or analyzed. However, these savings will likely be offset by the quarterly sampling
and analysis of the three operating extraction wells, which might have otherwise been done on an annual
basis.
In summary, the RSE team believes that the above changes will result in an effective monitoring program
that saves EPA approximately $54,000 per year (rounded down from $54,300 per year).
33
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6.2.4
PILOT TEST BYPASSING THE AIR STRIPPER
The air stripper was included in the design due to substantially higher expected concentrations of VOCs
in the influent. Because those VOCs are not present at the expected concentrations in the system influent
and the GAC is capable of providing the necessary VOC removal, the value of the air stripping step is
questionable. The air stripper blower costs approximately $13,000 in electricity per year to operate, and
the in-line heater (assuming it operates 75% of the time) costs another $8,000 in electricity per year to
operate. Bypassing the air stripper should save approximately $21,000 per year in direct costs or $24,800
including G&A and contractor fee. Recognizing that the GAC may need one additional change out per
year, the net savings may be on the order of $12,000 per year in direct costs or $14,000 including G&A
and contractor fee.
Bypassing the air stripper could be done immediately by discontinuing the operation of the blower and the
in-line heater. The site team will continue to monitor the GAC performance through the monthly sample
collected between the GAC units. If the site team determines that more than two GAC changes are
required per year while the air stripper is bypassed, then the site team should consider using the air
stripper again.
Despite a potential increase in GAC usage, the RSE team estimates that the site team will be able to
realize savings of at least $10,000 per year by bypassing the air stripper. Additional minor savings may
be realized if fewer bag filter changeouts are needed for the bag filter units located downstream of the air
stripper.
6.2.5
CONSIDER A HYBRID TIME & MATERIALS AND FIXED-PRICE CONTRACT
The current contract for system O&M is fixed-price, which means that the contractor must provide the
stated services for a fixed cost. To cover the risk of potential unknowns, a contractor will often add in
substantial contingency into a fixed-price contract to cover those unknowns. In this case, the client (EPA)
pays for the reasonable worst-case cost scenario even if that reasonable worst-case does not happen. As
an example, the contract for three month period includes $7,400 per month for consumables and disposal
costs. This translates to $88,800 per year in direct costs or $105,000 per year including the markup. This
direct cost of $88,800 per year in direct costs appears to include substantial contingency. The following
table summarizes conservative costs that the RSE team assumes would fall under this category. The
actual costs are likely lower than these estimated by the RSE team.
Item
Two liquid phase GAC changeouts per year
Chemicals
• Potassium permanganate
• Sulfuric acid
Bag filters
Disposal
Minor repairs (including parts)
Total
Conservative RSE Estimated Cost
$18,000*
$5,000
$10,000**
$15,000
$18,000
$66,000
* based on costs provided in the negotiated contract
** actual costs are much lower (likely under $5,000)
The above table suggests that the fixed-price contract includes an additional $22,800 in direct costs
beyond those that the RSE team conservatively estimates would be needed. With the markups included,
this translates to approximately $27,000 in extra costs to EPA.
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In future contacts, the RSE team recommends bidding O&M for one year with two to four option years.
The contract should include a fixed-price for operator labor, project management, and other labor (e.g.,
health and safety coordinator and procurement), and the contract should be time and materials for
chemicals, disposal, GAC replacement, and minor utilities. Electricity should be billed directly to
USAGE or EPA to save the markup of approximately $8,500. If, for whatever reason, the electricity
cannot be direct billed, the electricity should also be billed time and materials due to the uncertainty of
electricity rate escalation and electricity demand for building heat.
In summary, the RSE team believes that implementing this recommendation will save at least $35,500
($27,000 plus $8,500) and possibly more. If the GAC and waste disposal can be contracted directly by
the USAGE rather than by the site contractor, the cost of the markup on those items could also be
eliminated.
6.2.6 REDUCTIONS IN PROJECT MANAGEMENT CONSISTENT WITH STEADY STATE
SYSTEM OPERATION
The current project management costs ($96,000 including travel for the contractor and $60,000 for
USAGE) are very high for an operating P&T system and are likely the result of the problems associated
with the first several months of startup. Appropriate project management costs from the site contractor
during steady-state operation of the treatment plant (including procurement, health and safety, etc.) could
be provided for approximately $3,000 per month ($36,000 per year). By comparison, several Fund-lead
P&T systems in Region 3 have project management costs of under $36,000 per year. Only the much
more complicated systems have project management as high as $60,000 per year. In addition, the
oversight provided by USAGE could also be likely reduced during future steady-state operation to
approximately $3,000 per month ($36,000 per year). In summary, the reduction of project management
costs as the system operation becomes smoother should result in savings of approximately $84,000
($96,000+$60,000 - $36,000 - $36,000 = $84,000) per year compared to those currently incurred at the
site.
6.3 RECOMMENDATIONS FOR TECHNICAL IMPROVEMENT
6.3.1 RE-LOCATE EQUALIZATION TANK HIGH-LEVEL SWITCH
The equalization tank high level switch should be lowered to increase the distance between the high level
switch and the high-high level switch. This should reduce unnecessary alarms and associated labor. This
change will require additional plumbing with system operation temporarily discontinued because the sight
glass does not have an isolation valve. While this change is being made and the system is shut down,
isolation valves should be added to all sight glasses to facilitate future maintenance. The RSE team
estimates that these modifications should be made for under $10,000 in direct costs or approximately
$12,000 including markups.
6.3.2 DISCONTINUE USE AND SERVICE TO GENERATOR
The site team maintains a diesel generator to operate the treatment system in case of a power outage. The
RSE team does not believe that such a protective measure is necessary. Typical power outages last less
than a day, and a severe power outage may last for up to a week. Given that ground water flow at the site
is relatively slow (typically less than 0.02 feet per day), even a week long shutdown would only allow
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ground water to migrate a fraction of a foot. As such, the RSE team recommends that resources (time and
funding) be allocated to more important aspects of site O&M. Other EPA facilities may be in much
greater need of the diesel generator.
6.3.3 MODIFY USE OF WATER LEVELS FROM OPERATING EXTRACTION WELLS WHEN
DEVELOPING POTENTIOMETRIC SURFACE MAPS
Because water levels in operating extraction wells are affected by well losses and well inefficiencies that
substantially lower the water level in the well compared to the surrounding aquifer, they may bias the
development of potentiometric surface maps in favor of capture. As such, it is more appropriate to either
discontinue their use in developing potentiometric surface maps or to correct the water levels to account
for these factors. For extraction wells EW-1B and EW-4B there are monitoring wells sufficiently close to
the extraction wells such that the water levels from EW-1B and EW-4B can be excluded when preparing
the potentiometric surface map. However, for EW-2B, it is more appropriate to correct the measured
water level to better represent the water level in the aquifer in the vicinity of the extraction well.
Appendix B of this report provides a methodology for partially correcting the water levels by accounting
for the effects of well losses. Ideally, the drawdown in the extraction well should scale linearly with the
extraction rate, but well losses will cause the drawdown to increase non-linearly with the extraction rate.
Once they are determined as discussed in Appendix B, effects of well losses can be added to the water
level from the operating extraction well and the potentiometric surface map can be prepared. Although
other aspects of well inefficiency may still be present, this will nevertheless represent an improved
estimate of the water level in the aquifer adjacent to the extraction well. The additional cost associated
with this task should be less than $5,000. This cost includes planning by a senior scientist plus travel to
the site by a technician to measure water levels in the extraction well while the treatment plant operator
varies the flow. The data can be easily interpreted and explained within the current estimated budget for
preparing the ground water monitoring report.
6.4 CONSIDERATIONS FOR GAINING SITE CLOSE OUT
The RSE team does not have any recommendations for this category. The RSE team believes that
complete aquifer restoration will not occur within a reasonable time frame due to the presence of DNAPL
in relatively tight unconsolidated material and bedrock. As such, the above recommendations are geared
toward long-term cost-effective P&T operation. During the next Five-Year Review, the site team might
begin considering a Technical Impracticability waiver for the site.
36
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7.0 SUMMARY
The observations and recommendations contained in this report are not intended to imply a deficiency in
the work of either the system designers or operators, but are offered as constructive suggestions in the
best interest of the EPA and the public. These recommendations have the obvious benefit of being
formulated based upon operational data unavailable to the original designers.
Recommendations are provided in the following three of the four categories: effectiveness, cost reduction,
and technical improvement. The effectiveness recommendations include instituting a routine ground
water monitoring program and providing options to EPA for additional plume delineation in ground water
and for evaluating soil vapor intrusion. The recommendations for cost reduction offer potential cost
savings of over $300,000 per year including projected savings for ground water monitoring.
Recommendations include changes to ground water extraction that will facilitate plant operation and
reduce operator labor. The recommendations also include suggested changes in contracting, potentially
bypassing the air stripper, and reducing project management costs as system operation becomes more
routine. The recommendations for technical improvement include general maintenance to sight glasses
and level switches, including relocation of the high-level switch in the equalization tank to reduce the
likelihood of unnecessarily tripping the high-high level switch. The site is in its first year of a Long-Term
Remedial Action, and no recommendations are provided for gaining site closure.
Table 7-1 summarizes the costs and cost savings associated with each recommendation. Both capital and
annual costs are presented. Also presented is the expected change in life-cycle costs over a 30-year
period for each recommendation both with discounting (i.e., net present value) and without it.
37
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Table 7-1. Cost Summary Table
Recommendation
6.1.1 Institute a Routine
Ground Water Monitoring
Program
6. 1.2 Optional Plume
Delineation
6. 1.3 Soil Vapor Intrusion
Evaluation
6.2.1 Discontinue Pumping
From the Intermediate
Zone
6.2.2 Consider
Modifications to the
Backwashing and Solids
Handling Procedures
(Contingent on Outcome
Of 6.2.1)
6.2.3 Suggestions for
Long-Term Ground Water
Monitoring
6.2.4 Pilot Test Bypassing
the Air Stripper
6.2.5 Consider a Hybrid
Time & Materials and
Fixed-Price Contract
6.2.6 Reductions in Project
Management Consistent
with Steady State System
Operation
6.3.1Re-Locate
Equalization Tank High-
Level Switch
6.3.2 Discontinue Use and
Service to Generator
6.3.3 Modify Use of Water
Levels from Operating
Extraction Wells when
Developing Potentiometric
Surface Maps
Total
Reason
Effectiveness
Effectiveness
Effectiveness
Cost
Reduction
Cost
Reduction
Cost
Reduction
Cost
Reduction
Cost
Reduction
Cost
Reduction
Technical
Improvement
Technical
Improvement
Technical
Improvement
Additional
Capital
Costs ($)
$0
$35,000
$15,000
$15,000
$100,000
$0
$0
$0
$0
$12,000
$0
$5,000
$182,000
Estimated
Change in
Annual
Costs ($/yr)
See 6.2.3
$0
$0
($104,000)
($28,000)
($54,000)
($14,000)
($35,500)
($84,000)
$0
$0
$0
($319,500)
Estimated
Change in
Life-cycle
Costs ($)*
See 6.2.3
$35,000
$15,000
($3,105,000)
($740,000)
($1,620,000)
($420,000)
($1,065,000)
($2,520,000)
$12,000
$0
$5,000
($9,403,000)
Estimated
Change in Life-
cycle Costs
($)**
See 6.2.3
$35,000
$15,000
($1,664,000)
($352,000)
($872,000)
($226,000)
($573,000)
($1,356,000)
$12,000
$0
$5,000
($4,976,000)
Costs in parentheses imply cost reductions
* assumes 30 years of operation with a discount rate of 0% (i.e., no discounting)
** assumes 30 years of operation with a discount rate of 5% and no discounting in the first year
38
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FIGURES
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FIGURE 1-1. SITE MAP WITH WELL LOCATIONS
LEGEND
S MONITORING WELL
4- PIEZOMETER
• EXTRACTION WELL
4- FORMER PIEZOMETER LOCATION
100
B
SCALE
200
^
FEET
GCL Tie and Treating Site
Operable Unit 2
Sidney, New York
(Note: This figure was prepared by CDM as part of the Ground-water Sampling Report for the Spring 2006 Event.)
Figure 1
Well Location Map
11
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APPENDIX A:
BIOSCREEN ANALYSIS
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SELECTION OF BIOSCREEN INPUT PARAMETERS
NAPHTHALENE ATTENUATION
GCL TIE & TREATING SUPERFUND SITE
BIOSCREEN was run to simulate the attenuation of naphthalene between the source area located near
MW-7B and downgradient well MW-1 IB. The results were also used to estimate the distance
downgradient of MW-1 IB that would be required for the naphthalene concentrations to attenuate below
the cleanup criteria of 50 ug/L. The following values were used for input parameters:
Parameter
Hydraulic conductivity
Hydraulic gradient
Effective porosity
Longitudinal dispersivity
Transverse dispersivity
Vertical dispersivity
Retardation factor
Degradation half -life
Source area concentration
Value
0.5 feet per day ( 1. 8 *10~4 cm/sec)
0.01 feet per foot
0.2
17.9
1.8
0
1
4.5
7,000 ug/L
Explanation
Measured with pump test
Interpreted from potentiometric surface maps
Conservatively estimated
Calculated using BIOSCREEN manual
Calculated using BIOSCREEN manual
Conservatively estimated
Conservatively estimated
Conservatively estimated at more than 6 times
upper end value from Michalenko, E.M.,
Handbook of Environmental Degradation
Rates, Lewis Publishers, 1991
Consistent with values from MW-7B
The simulation with this set of parameters results in a naphthalene concentration of 112 ug/L 300 feet downgradient
of the source area. This agrees with the measured concentration of 110 ug/L of naphthalene at MW-1 IB, which is
approximately 300 feet downgradient of MW-7B. It is further noted that the simulated naphthalene concentration
decreases to 27 ug/L (i.e., below the standard of 50 ug/L) within 400 feet of the source area.
Print outs of the input and output screens for the above simulation are provided on the following pages.
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BIOSCREEN Natural Attenuation Decision Support System
Air Force Center for Environmental Excellence
1. HYDROGEOLOGY
Seepage Velocity* Vs
or
Hydraulic Conductivity K
Hydraulic Gradienl ;
Porosity n
(ft/yr)
(cm/sec)
(ft/ft)
2. DISPERSION
Longitudinal Dispersivity alpha x
Transverse Dispersivity alpha y
Vertical Dispersivity' alpha z
or
Estimated Plume Length Lp
3. ADSORPTION
Retardation Factor* R
or
Soil Bulk Densitv rho
Partition Coefficienl Koc
FractionOrganicCarbor foe
4. BIODEGRADATION
1st Order Decay Coeff* lambda
or
Solute Half-Life t-half
or Instantaneous Reaction Mode
Delta Oxygen* DO
Delta Nitrate* NO3
Observed Ferrous Iron' Fe2+
Delta Sulfate* SO4
Observed Methane* CH4
Version 1.4
GCL Tie & Treating
Run Name
5. GENERAL
Modeled Area Length*
Modeled Area Width*
Simulation Time*
Data Input Instructions:
1. Enter value directly....or
2. Calculate by filling in grey
cells below. (To restore
formulas, hit button below).
Variable* Data used directly in model.
\ —*• Value calculated by model.
(Don't enter any data).
6. SOURCE DATA
Source Thickness in Sat.Zone
Vertical Plane Source: Look at Plume Cross-Section
and Input Concentrations & Widths
Source Zones:
View of Plume Looking Down
Observed Center/me Concentrations at Monitoring Wells
If No Data Leave Blank or Enter "O1
In Source NAPL, Soil
7. FIELD DATA FOR COMPARISOIV
Concentration (mg/L)
Dist. from Source (ft)
8. CHOOSE TYPE OF OUTPUT TO SEE:
RUN
CENTERLINE
RUN ARRAY
Recalculate This
Sheet
Paste Example Dataset
Restore Formulas for Vs,
Dispersivities, R, lambda, other
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DISSOLVED HYDROCARBON CONCENTRATION ALONG PLUME CENTERLINE (mg/L at Z=0)
Distance from Source (ft)
TYPE OF MODEL
No Degradation
1st Order Decay
Inst. Reaction
Field Data from Site
0
7.000
7.000
7.000
100
6.993
1.794
6.993
200
6.861
0.452
6.861
300
6.600
0.112
6.600
400
6.303
0.027
6.303
500
6.015
0.007
6.015
600
5.749
0.002
5.749
700
5.508
0.000
5.508
800
5.291
0.000
5.291
900
5.094
0.000
5.094
1000
4.914
0.000
4.914
'1st Order Decay
'Instantaneous Reaction
Degradation
Field Data from Site
8.000 q
7.000
J 6.000
I ^.000 \
a ^3.000
U 2.000
1.000 \
0.000 =
0
200
400 600
Distance From Source (ft)
800
1000
1200
Calculate
Animation
Time:
200 Years
Return to
Input
Recalculate This
Sheet
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APPENDIX B:
CALCULATION OF WELL LOSSES
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USING SPECIFIC CAPACITIES FROM A STEP-DRAWDOWN TEST TO ESTIMATE
WELL LOSSES AT EXTRACTION WELLS DUE TO TURBULENT FLOW
Ground water flow across the well screen is turbulent due to large hydraulic gradients. For this case
Jacob (1950) proposed the following expression for drawdown inside the well casing, sw:
sw = BQ + CQ2
SL = CQ2
Where
sw = drawdown inside the well casing
SL = well loss
C = a "well coefficient", a measure of the head loss due to turbulent flow in the well screen and pump
inlet
B = an "aquifer coefficient"', a measure of the head loss due to laminar (Darcy) flow in the aquifer
Q = pumping rate
Bierschenk (1964) developed a graphical method for determining coefficients B and C. It is based on a
plot of specific capacity versus pumping rate from a step-drawdown test, which assumes that an
equilibrium drawdown in the pumping well will be established during the step-drawdown test for several
pumping rates.
sw/Q = CQ + B
100
90
^ SO
4
"3 70
£
M .
a 60
'a
B
Drawdown in Pu
o o o o c
Pi
Pumping Rate Ql
\
Pumping Rate Q5
\
\
^—
Pumping Rate Q4
Pumping Rate Q3
^
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2. For each pumping rate, record the equilibrium drawdown at the pumping well (sw)
3. Plot sw/Q versus Q on arithmetic scale as shown in the lower figure. Fit a straight line through
the data and extend the fitted line to a zero pumping rate. The slope of the line is C and the y-
intercept is B.
4. Calculate the well loss associated with a specific pumping rate, SL = CQ2
Qi
Q2 Q3 Q4
Pumping Rate, Q (gpm )
Q5
References
Bierschenk, W.H. 1964. Determining Well Efficiency by Multiple Step-Drawdown Tests. International
Association of Scientific Hydrology, Publication 64, pp. 494-505.
Jacob, C.E. 1950. Flow of groundwater, in Engineering Hydraulics (H. Rouse, Ed.), Chap. 5, pp. 321-
386, Wiley, New York.
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