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5
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EPA-542-R-16-004
Office of Land and Emergency Management
Office of Superfund Remediation and
Technology Innovation
Optimization Review Report
Saunders Supply Company Superfund Site
Suffolk County, Virginia
EPA Region 3
FINAL-August 2016
www.clu-in.org/optimization | https://www.epa.gov/superfund/cleanup-optimization-superfund-sites
Prepared for United States Environmental Protection Agency
Prepared by ICF International
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Optimization Review Report - Sounders Supply Company Superfund Site
EXECUTIVE SUMMARY
Optimization Background
U.S. Environmental Protection Agency defines optimization as the following:
"Efforts at any phase of the removal or remedial response to identify and implement specific actions
that improve the effectiveness and cost-efficiency of that phase. Such actions may also improve the
remedy's protectiveness and long-term implementation which may facilitate progress towards site
completion. To identify these opportunities, regions may use a systematic site review by a team of
independent technical experts, apply techniques or principles from Green Remediation or Triad, or
apply some other approaches to identify opportunities for greater efficiency and effectiveness.
Contractors, states, tribes, the public, andPRPs are also encouraged to put forth opportunities for
the Agency to consider.":
An optimization review considers the goals of the remedy, available site data, conceptual site model
(CSM), remedy performance, protectiveness, cost-effectiveness, and closure strategy. A strong interest in
sustainability has also developed in the private sector and within Federal, State, and Municipal
governments. Consistent with this interest, optimization now routinely considers green remediation and
environmental footprint reduction during optimization reviews.
An optimization review includes reviewing site documents, interviewing site stakeholders, potentially
visiting the site for one day, and compiling a report that includes recommendations in the following
categories:
Remedy effectiveness
Cost reduction
Technical improvement
Site closure
Environmental footprint reduction
The recommendations are intended to help the site team identify opportunities for improvements in these
areas. 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 review, and represent the opinions of the optimization review team. These recommendations
do not constitute requirements for future action, but rather are provided for consideration by the EPA
Region and other site stakeholders. Also note that while the recommendations may provide some details
to consider during implementation, the recommendations are not meant to replace other, more
comprehensive, planning documents such as work plans, sampling plans, and quality assurance project
plans (QAPP).
Site-Specific Background
The Saunders Supply Company Superfund Site (Saunders site) is located in Suffolk County, Virginia, in
EPA Region 3, and is a 7-1/3 acre former wood treating plant. The site was added to the National
U.S. Environmental Protection Agency. 2012. Memorandum: Transmittal of the National Strategy to Expand
Superfund Optimization Practices from Site Assessment to Site Completion. From: James. E. Woolford, Director
Office of Superfund Remediation and Technology Innovation. To: Superfund National Policy Managers
(Regions 1 - 10). Office of Solid Waste and Emergency Response (OSWER) 9200.3-75. September 28.
ES-1
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Optimization Review Report - Sounders Supply Company Superfund Site
Priorities List (NPL) on October 4, 1989. A Record of Decision (ROD) was signed in September 1991. A
ROD Amendment was signed in September 1996. The source areas included wastewater ponds, treatment
areas, and burn pits located on the Saunders property and were remediated by removing liquids and
contaminated soil. Primary contaminants are currently pentachlorophenol (PCP), arsenic, and chromium
in groundwater. The site is in the operation and maintenance (O&M) phase and uses a groundwater pump
and treat (P&T) system to control migration of the contaminants and remove contaminant mass from the
aquifer. The P&T system is intended to be operated until cleanup goals are achieved.
Summary of Conceptual Site Model and Key Findings
The subsurface geology at the Saunders site can be divided into three basic units: an uppermost unit of
fine- to medium-grained sand that extends to a depth of approximately 12 feet across most of the site (this
unit is identified as the Columbia aquifer); a fine-grained green-gray clayey confining unit approximately
2 to 7 feet in thickness is located beneath the uppermost sandy unit; and an approximately 55 foot thick
gray silt and sandy silt unit is located beneath the green-gray clayey unit (this unit is identified as the
Yorktown aquifer or Yorktown Confining Unit). The Columbia and the Yorktown aquifers are the two
hydrostratigraphic units identified at the site and are separated by the fine-grained clayey unit. The water
table occurs in the Columbia aquifer and the depth to water varies across the site but averages about 10
feet below ground surface (bgs) (COM, 2006b). No nearby residential wells tap the Columbia aquifer.
The Columbia aquifer intersects Godwin's Millpond, a surface water supply for the Chuckatuck area of
Suffolk. An intermittent stream is located on the western edge of the property and discharges to Godwin's
Millpond. The Kelly irrigation well, located approximately 300 feet from the Saunders property line,
likely withdrew water from the Yorktown aquifer when it was operational.
Groundwater in the Columbia aquifer and upper Yorktown Confining Unit contains concentrations of
PCP, arsenic, and chromium above U.S. EPA Maximum Contaminant Levels (MCLs). Four extraction
wells capture contaminated groundwater and provide hydraulic control, however the volume of water
captured and the mass of contaminants removed is low. The system began operating as part of a time
critical removal action in 1988 and is currently operated and maintained by the Commonwealth of
Virginia.
The optimization review team identified uncertainties about the extent of contamination near the sources
and downgradient as a data gap in the CSM. The interaction of the shallow groundwater and the
intermittent stream and Godwin's Millpond is also a data gap in the CSM. The site team determined that
the current treatment system is adequate in meeting discharge criteria, however, the remedy has not
succeeded in reducing contaminant concentrations in the aquifer and reaching groundwater cleanup levels
(MCLs). Therefore, the optimization review team agrees that a revised strategy must be implemented that
also focuses on contaminant mass removal and aquifer restoration. The current optimization review of the
site is intended to improve recovery of PCP, arsenic, and chromium from the contaminated aquifer at the
site.
Summary of Recommendations
Recommendations are provided to improve understanding of the site conditions by addressing data gaps
in the CSM and improve effectiveness of the existing remedial system. The optimization review team also
provided recommendations for alternative technologies to accelerate the removal of contaminants. The
recommendations in these areas are as follows:
Remedy effectiveness -
Recommendations to improve the effectiveness of the proposed remedy include a sequenced approach to
improve the capacity and mass removal rate of the current remedy and consideration of other treatment
technologies to enhance the mass removal. Recommendations also include developing completion
strategies for plume control and containment, aquifer restoration, and any new mass reduction
ES-2
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Optimization Review Report - Sounders Supply Company Superfund Site
technologies that may be implemented. Developing and observing these criteria will help avoid operating
long-term remedies longer than necessary.
The optimization review team recommends additional characterization of the source and downgradient
plume areas to better understand the distribution of contaminants so that improvements to the
groundwater treatment system can maximize the removal of contaminants from high concentration areas.
As part of the characterization, the interaction of the groundwater with the intermittent stream and
Godwin's Millpond will help ensure the groundwater system effectively captures contaminants
throughout the site. The optimization review team also recommends updating the capture zone analysis to
determine whether containment is adequate based on the current day plume configuration and extraction
well pumping rates, or if improvements to the extraction system are necessary.
The optimization review team recommends confirming that the RAOs are consistent with current site
conditions and exposed populations because the current RAOs are based on site conditions before 1991.
Potential exposure points could include recently installed private wells (if present), Godwin's Millpond,
and the Kelly irrigation well.
A groundwater performance monitoring plan is recommended to confirm control of the plume and the
performance of the P&T system.
Cost reduction -
Recommendations to characterize the source and downgradient areas are anticipated to reduce costs over
the lifetime of the project. Additional costs associated with sampling are estimated at $125,000; however
costs are anticipated to be offset by more efficient contaminant mass removal and a shorter operation life
time for the P&T remedy.
Recommendations for improving extraction well pumping rates and increasing treatment system capacity
are also anticipated to reduce life-cycle costs. Remedy performance monitoring along with establishing
remedy operation completion criteria for each remedy component can ensure that the performance
monitoring procedures remain relevant to the remedy as it continues to operate into the future.
Technical improvement -
Technical improvements for the existing remedy are anticipated to result from additional site
characterization (to optimize placement of extraction wells), additional maintenance and replacement of
system components, consideration of combined treatment technologies, and remedy performance
monitoring. Prioritizing increased mass removal is anticipated to provide the maximum improvement in
the long-term performance of the P&T system.
Site closure -
Recommendations that are anticipated to shorten the time to attain cleanup goals include additional source
area characterization, increasing the mass removal rate of contaminants with the existing system or
supplemental technologies, and implementing remedy performance monitoring.
Environmental footprint reduction -
Due to the relatively small environmental footprint of the current P&T system, no specific
recommendations have been identified for green remediation or environmental footprint reduction.
However, several of the other optimization recommendations have the potential to reduce the remedy
footprint by either streamlining the treatment process or reducing the likelihood of operating a remedy
component past the point of measureable benefit in achieving the RAOs. Additionally, implementation of
the recommendations could result in achievement of restoration in a shorter time frame, and thus reducing
the remedy's overall environmental footprint.
ES-3
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Optimization Review Report - Sounders Supply Company Superfund Site
NOTICE AND DISCLAIMER
Work described herein was performed by ICF International (ICF) for the U.S. Environmental Protection
Agency. Work conducted by ICF, including preparation of this report, was performed under Task Order
0008 of EPA contract EP-W-14-001 with ICF Incorporated, LLC. The report was approved for release as
an EPA document, following the Agency's administrative and expert review process.
This optimization review is an independent study funded by the EPA that focuses on remedy
effectiveness, cost reduction, site closure, technical improvements, and environmental footprint reduction.
Detailed consideration of EPA policy was not part of the scope of work for this review. This report does
not impose legally-binding requirements, confer legal rights, impose legal obligations, implement any
statutory or regulatory provisions, or change or substitute for any statutory or regulatory provisions.
Mention of trade names or commercial products does not constitute endorsement or recommendation for
use.
Recommendations are based on an independent evaluation of existing site information, represent the
technical views of the optimization review team, and are intended to help the site team identify
opportunities for improvements in the current site remediation strategy. These recommendations do not
constitute requirements for future action; rather, they are provided for consideration by the EPA Region
and other site stakeholders.
While certain recommendations may provide specific details to consider during implementation, these
recommendations are not meant to supersede other, more comprehensive, planning documents such as
work plans, sampling plans and quality assurance project plans (QAPP); nor are they intended to override
applicable or relevant and appropriate requirements (ARARs). Further analysis of recommendations,
including review of EPA policy may be needed prior to implementation.
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Optimization Review Report - Saunders Supply Company Superfund Site
PREFACE
This report was prepared as part of a national strategy to expand Superfund optimization practices from
site assessment to site completion implemented by the United States Environmental Protection Agency
Office of Superfund Remediation and Technology Innovation (OSRTI)2 The project contacts are as
follows:
Organization
Key Contact
Contact Information
EPA Office of Superfund
Remediation and Technology
Innovation
(OSRTI)
Kirby Biggs
Edward Gilbert
Matthew Jefferson
Amanda Van Epps
EPA OSRTI
Technology Innovation and Field
Services Division (TIFSD)
2777 Crystal Drive
Arlington, VA 22202
biggs.kirby@epa.gov
phone: 703-823-3081
gilbert.edward@epa.gov
phone: 703-603-8883
jefferson.matthew@epa.gov
phone: 703-603-8892
vanepps.amanda@epa.gov
phone: 703-603-8855
ICF International
(Contractor to EPA)
Therese Gioia
ICF International
Therese.Gioia@icfi.com
phone: 815-923-2368
Kevin Palaia
Jim Rice
ICF International
100 Cambridgepark Drive, Suite 501
Cambridge, MA 02140
Kevin.Palaia@icfi.com
phone: 617-250-4271
James.Rice@icfi.com
phone: 617-250-4280
The national optimization strategy includes a system for tracking consideration and implementation of the
optimization recommendations, and, for some sites, includes a provision for follow-up technical
assistance from the optimization review team as mutually agreed upon by the site management team and
EPA OSRTI.2
2 U.S. Environmental Protection Agency. 2012. Memorandum: Transmittal of the National Strategy to Expand
Superfund Optimization Practices from Site Assessment to Site Completion. From: James. E. Woolford, Director
Office of Superfund Remediation and Technology Innovation. To: Superfund National Policy Managers
(Regions 1 - 10). Office of Solid Waste and Emergency Response (OSWER) 9200.3-75. September 28.
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Optimization Review Report - Sounders Supply Company Superfund Site
LIST OF ACRONYMS
ARAR Applicable or Relevant and Appropriate Requirement
bgs Below ground surface
CERCLA Comprehensive Environmental Response Compensation and Liability Act
CSM Conceptual site model
COC Contaminant of concern
DNAPL Dense non-aqueous phase liquid
DPT Direct-push technology
DQO Data quality objective
DSITMS Direct Sampling Ion Trap Mass Spectroscopy
EA Environmental Alliance, Inc.
E&E Ecology & Environment
EPA U.S. Environmental Protection Agency
FS Feasibility study
ft feet
GAC Granular activated carbon
GC/MS Gas chromatograph/mass spectrometry
gpm gallons per minute
HRSC High Resolution Site Characterization
HQ Headquarters
ICF ICF International
ITRC Interstate Technology and Regulatory Council
Ib pound
LIF Laser Induced Fluorescence
LTM Long-term Monitoring
MCL Maximum Contaminant Level
mg/kg milligrams per kilogram
MIP Membrane Interface Probe
MW Monitoring well
NPL National Priorities List
O&F Operational and Functional
O&M Operation and Maintenance
OSRTI Office of Superfund Remediation and Technology Innovation
PCP Pentachlorophenol
PDB Passive diffusion bag
P&T Pump and treat
PV photovoltaics
QAPP Quality Assurance Project Plan
RA Remedial Action
RAO Remedial action objective
RD Remedial design
RI Remedial investigation
ROD Record of Decision
RPM Remedial Project Manager
SVOC Semi-volatile organic compound
TIFSD Technology Innovation and Field Services Division
(ig/L micrograms per liter
VDEQ Virginia Department of Environmental Quality
in
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Optimization Review Report - Sounders Supply Company Superfund Site
TABLE OF CONTENTS
Section Page
EXECUTIVE SUMMARY ES-1
NOTICE AND DISCLAIMER i
PREFACE ii
LIST OF ACRONYMS iii
1.0 OBJECTIVES OF OPTIMIZATION REVIEW 1
2.0 OPTIMIZATION REVIEW TEAM 2
2.1 Quality Assurance 2
3.0 REMEDIAL ACTION OBJECTIVES AND SELECTED REMEDIES 3
3.1 Remedial Action Objectives and Affected Media 3
3.2 Selected Remedies 6
3.3 Current Completion Strategy 7
4.0 DATA GAPS 8
4.1 Data Gaps in Characterization 8
4.2 Review of Current Remedial Strategy 8
5.0 FINDINGS AND RECOMMENDATIONS 10
5.1 Recommendations to Characterize the Site for Remedy Refinement 10
5.2 Recommendations to Confirm Exposure Assumptions 13
5.3 Recommendations for Improving Remedy Effectiveness 14
5.4 Recommendations for Current Extraction and Treatment System Improvements 15
5.5 Recommendations for Remedy Performance Monitoring 17
5.6 Recommendation for Establishing Remedy Operation Completion Criteria 19
5.7 Recommendations for Green Remediation and Environmental Footprint Reduction 20
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Optimization Review Report - Sounders Supply Company Superfund Site
TABLES
Table Page
Table 1: Optimization Review Team 2
Table 2: Other Optimization Review Contributors 2
Table 3: Contaminants of Concern for Groundwater and MCLs 5
Table 4: Affected or Potentially Affected Media on Site 5
Table 5: Remedial Action Objectives as Described in the Record of Decision 5
Table 6: Remedy Components Documented in the ROD Amendment 6
Table 7: Identified Data Gaps 8
Table 8: Contaminant Mass Removed 2012-2015 14
Table 9: Groundwater Extracted by P&T System from 2012 to 2015 15
Table 10: Recommendation Summary 21
FIGURES
Figure Page
Figure 1: Site location. (Excerpt from Figure 1-1 of the May 1991 RI. A full size version of this figure is
provided in Appendix B.) 1
Figure 2: Site Stratigraphy showing the upper water bearing unit (Columbia aquifer) and Godwin's
Millpond. (Figure is an excerpt of Figure 4-1 from December 2006 Hydrogeological Analysis
Report. A full size version of the figure is provided in Appendix B.) 4
APPENDICES
Appendix A: References
Appendix B: Supporting Figures from Existing Documents
Appendix C: Site Photographs
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Optimization Review Report - Saunders Supply Company Superfund Site
1.0 OBJECTIVES OF OPTIMIZATION REVIEW
For more than a decade, the Office of Superfund Remediation and Technology Innovation (OSRTI) has
provided technical support to the EPA regional offices through the use of independent (third party)
optimization reviews at Superfund sites. The Saunders Supply Company Superfund Site (Saunders site)
was nominated for an optimization review at the request of the Region 3 Remedial Project Manager
(RPM) in September 2015. The current optimization review of the site is intended to improve recovery of
pentachlorophenol (PCP), arsenic, and chromium from the contaminated aquifer at the site. The existing
groundwater pump and treat (P&T) system began operation in 1998 and is currently operated and
maintained by the Commonwealth of Virginia.
Figure 1: Site Location (Excerpt from Figure 1-1 of May 1991 RI
[E&E, 1991]. A full size version of this figure is provided in Appendix B.)
The site is located in Suffolk County Virginia, in
EPA Region 3, and is a 7-1/3 acre former wood
treating plant (Figure 1). The site was added to
the National Priorities List (NPL) on October 4,
1989, and activities under the Comprehensive
Environmental Response Compensation and
Liability Act (CERCLA) have been ongoing
since this time. Remedial Investigation (RI)
(E&E, 1991) and Feasibility Study (FS) (EPA,
199 la) reports for the site were finalized in May
1991 and a Record of Decision (ROD) (EPA,
1991b) was signed in September 1991. A ROD
Amendment (EPA, 1996) was signed in
September 1996. The site is currently in the
operation and maintenance (O&M) phase.
An optimization review team (described below)
was assembled and met with regulatory
stakeholders and consultants at the site to
observe site conditions, review site data and
remediation goals, and discuss the technical
aspects of the existing remedy and its
performance toward achieving remediation
goals. The optimization review team also
reviewed site documents provided by EPA
Region 3 and Virginia Department of
Environmental Quality (VDEQ). This report
summarizes the findings and recommendations
of the optimization review team.
Objectives of this cleanup-stage optimization review include:
Review of conceptual site model (CSM)
Review of Remedial Action Objectives (RAO)
Review of ongoing remedies and associated costs
Provide recommendations for:
o CSM improvements
o Remedy improvements
o Prioritization and sequencing of the remedy components
o Performance monitoring metrics in support of completion for each remedy component
Souit*- USGS 7.5 Minui*
rtic) Quidr*rปgiซt Chuck*luefc, Viifllnn. 1B79
SCALE
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Optimization Review Report - Saunders Supply Company Superfund Site
2.0 OPTIMIZATION REVIEW TEAM
The optimization review team consisted of the independent, third-party participants listed in Table 1. The
optimization review team collaborated with representatives of EPA Headquarters (HQ) (OSRTI), EPA
Region 3, VDEQ, and Environmental Alliance, Inc. (EA), the current groundwater treatment system
O&M contractor for VDEQ.
The independent, third-party optimization review team consisted of the following individuals:
Table 1: Optimization Review Team
Name
Kirby Biggs
Edward Gilbert
Matthew Jefferson
Kevin Palaia
Jim Rice
Organization
EPA HQ OSRTI
EPA HQ OSRTI
EPA HQ OSRTI
ICF International
ICF International
Phone
703-823-3081
703-603-8883
703-603-8892
617-250-4271
617-250-4280
Email
biggs. kirby(S>epa.gov
gilbert.edward@epa.gov
iefferson.matthew.epa.gov
kevin.palaia(S>icfi.com
iames.rice(S>icfi.com
The individuals listed in Table 2 also contributed to the optimization review process:
Table 2: Other Optimization Review Contributors
Name
Lisa Denmark
Nathan Doyle
Karen Doran
Amanda Van Epps
Jim Cutler
Matt Richardson
Jimmy Mackey
Aaron Siegel
Organization
EPA Region 3
EPA Region 3
VDEQ
EPA HQ OSRTI
VDEQ
VDEQ
EA
EA
Title/Party
RPM
Region 3 Hydrogeologist
CERCLA Program Manager
Environmental Engineer
State RPM
Previously with EA, managed
treatment system at the site
Groundwater Treatment
System Operator
Groundwater Treatment
System Operator
Present for Site
Visit/Site Meeting
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
A site visit followed by a meeting occurred on December 1, 2015. Documents reviewed during the
optimization review process are listed in Appendix A.
2.1 Quality Assurance
This optimization review used existing environmental data to interpret the CSM, evaluate potential future
remedy performance, and make recommendations to improve the remedy. The quality of the existing data
was evaluated by the optimization review team before use. The evaluation for data quality included a
brief review of 1) how the data were collected and managed (where practical, the site QAPP was
considered), 2) whether various data sets are consistent with each other, and 3) whether and to what
extent the data can be used in the optimization review. Data that were of suspect quality were either not
used as part of the optimization review or were used with the quality concerns noted. Where appropriate,
this report provides recommendations to improve data quality.
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Optimization Review Report - Sounders Supply Company Superfund Site
3.0 REMEDIAL ACTION OBJECTIVES AND SELECTED REMEDIES
The Saunders site is the location of a former wood treating plant. Wood treating operations ceased in July
1991, but the site is still an active lumberyard. Between 1964 and 1984, a mixture of pentachlorophenol
(PCP) and fuel oil was used for wood preservation, with chromated copper arsenate added in 1974. Onsite
surface and subsurface soils, wastewater ponds, concrete pads, and storm sewer pipelines contained
elevated levels of PCP, arsenic, and chromium. The groundwater in the shallow Columbia aquifer is
contaminated with arsenic, chromium, and PCP. The aquifer intersects Godwin's Millpond, which is part
of a water supply source for approximately 30,000 people in Suffolk, Virginia. The current CSM is
described in documents including the ROD (EPA, 1991b), ROD Amendment (EPA, 1996), RI (E&E,
1991), FS (EPA, 199la), and the Third Five Year Review (EPA, 2014) listed in Appendix A. A summary
of the CSM components relevant to remedial design (RD) and remedial action (RA) is provided below.
3.1 Remedial Action Objectives and Affected Media
The basis for remedial action at the Saunders site was onsite soil contamination, wastewater ponds, storm
sewers, and groundwater contamination exceeding human health risk levels and Virginia Groundwater
Standards as a result of historic wood treating operations. A risk-based cleanup standard for PCP in soil,
the principal contaminant, was set at 1.46 milligram per kilogram (mg/kg), corresponding to a 10~6 risk
level.
RAOs for groundwater were not specifically listed as such in the ROD. However, they can be inferred
from the major components of the remedy as summarized in the ROD and later defined in a ROD
Amendment. The 1991 ROD identified groundwater monitoring as the preferred remedial action for
groundwater and stipulated that if monitoring results indicate concentrations of PCP greater than the
maximum contaminant level (MCL) of 1.0 microgram/liter (ng/L) at the boundary of the plume,
verification sampling would be conducted, and active groundwater restoration may be implemented.
Groundwater would also be monitored for arsenic and chromium but no action levels for these
components were set in the ROD. The primary focus of this optimization review is the groundwater
remedy, therefore the remainder of this report will only focus on remedies associated with the
groundwater media and potential sources of continued groundwater contamination.
The subsurface geology at the Saunders site can be divided into three basic units, which are illustrated in
Figure 2 and in the cross sections presented in Appendix B.
An uppermost unit of primarily fine- to medium-grained sand with some isolated silts and clay.
This uppermost unit extends to a depth of approximately 12 feet across most of the site. This unit
is identified as the Columbia aquifer on the cross sections.
A fine-grained green-gray clayey unit approximately 2 to 7 feet in thickness is located beneath
the uppermost sandy unit. This unit is identified as the confining clay on the cross sections.
A gray silt and sandy silt unit is located beneath the green-gray clayey unit. This unit is
approximately 55 feet thick in the site area and is identified as the Yorktown aquifer or Yorktown
Confining Unit on the cross sections.
The Columbia and the Yorktown aquifers are the two hydrostratigraphic units identified at the site and are
separated by the fine-grained clayey unit. The water table occurs in the Columbia aquifer and the depth to
water varies across the site but averages about 10 feet below ground surface (bgs) (COM, 2006b). No
nearby residential wells tap the Columbia aquifer (E&E, 1991). The Columbia aquifer intersects
Godwin's Millpond, a surface water supply for the Chuckatuck area of Suffolk. The deeper Yorktown
aquifer was not penetrated in any site borings, but is believed to be present at more than 75 feet bgs. The
Kelly irrigation well, located approximately 300 feet from the Saunders property line, likely withdrew
water from the Yorktown aquifer when it was operational (E&E, 1991). No documentation was identified
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Optimization Review Report - Saunders Supply Company Superfund Site
that definitively identifies the closure process and current status of the Kelly irrigation well. The nearest
residential well is located approximately 3,000 feet from the site and draws water from 566 feet bgs
(E&E, 1991).
Figure 2: Site Stratigraphy Showing the Upper Water Bearing Unit (Columbia aquifer) and Godwin's
Millpond. (Figure is an excerpt of Figure 4-1 from December 2006 Hydrogeological Analysis Report [CDM, 2006b]. A full size version of
the figure is provided in Appendix B.)
,2.043
Godwin's Millpond, also referred to as Crumps Millpond, is located approximately 700 feet north of the
Saunders property line. Godwin's Millpond is one of the water sources for the City of Suffolk. According
to the site team, approximately 1.7 million gallons per day are reportedly withdrawn from Godwin's
Millpond and stored in a series of water supply lakes located 1A mile north of the site. The water supply
serves a population of approximately 30,000. An intermittent stream is located on the western edge of the
property and discharges to Godwin's Millpond. Numerous seeps originating in the Columbia aquifer are
present on the east side of the incised stream valley, and discharge to the stream.
The primary site contaminant, pentachlorophenol (PCP) is a semivolatile organic compound (SVOC) that
is denser than water, has low solubility in water and tends to partition to soil particles. During site
operations, PCP was dissolved in fuel carrier oil to facilitate penetration into the wood. The RI (E&E,
1991) postulated that the petroleum hydrocarbons initially increased the mobility of PCP in groundwater,
but were subsequently degraded, leaving low concentrations of PCP in groundwater. Elevated
concentrations of diesel and other fuel constituents were not detected during the RI. PCP is not likely to
be found as free phase in the downgradient portion of the plume. These characteristics present challenges
in investigation and remedy selection, as reflected in the discussion below. Figures 6 and 7 in Appendix B
show the contaminant concentrations in the deep and shallow zones from the April 2015 sampling event.
Table 3 shows the groundwater contaminants of concern (COCs) and cleanup goals based on federal
MCLs.
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Optimization Review Report - Saunders Supply Company Superfund Site
Table 3: Contaminants of Concern for Groundwater and MCLs
Constituent Name
PCP
Arsenic
Chromium
Affected Media
Columbia Aquifer and
Yorktown Aquifer
MCL
LBS/L
10 Mg/L
100 ng/L
Note: (ig/L = micrograms per liter; PCP = pentachlorophenol
Table 4 summarizes the affected and potentially affected media along with potential exposure and
migration pathways. Table 5 lists RAOs for the site, as presented in the latest five-year review.
Table 4: Affected or Potentially Affected Media on Site
Medium
Columbia Aquifer
Yorktown
Confining Unit
Surface Water
Location
Approximately 8 feet of
saturated material
beginning at 2 to 12 feet
bgs
20 to 76 feet bgs
Intermittent stream on
west side of site;
Godwin's Millpond is
700 feet downgradient of
the Saunders Property
line
Composition
fine to coarse
sand with some
clay
predominantly
silt with shells,
some sandy silt
and clay
sandy bottom
stream bed;
pond is a
Cypress swamp
with mucky
organic
sediments
Potential Exposure / Migration
Pathways
Direct exposure by excavation
Discharge to Godwin's
Millpond and subsequent
municipal use
Discharge to unnamed
intermittent stream west of site
Discharge to deeper Yorktown
aquifer - primary public water
supply
Seeps on stream bank may
discharge into stream, and into
Godwin's Millpond
Godwin's Millpond is a
municipal drinking water
source
Table 5: Remedial Action Objectives as Described in the Record of Decision
Medium
Soils
Concrete Pads
Wastewater Pond
Storm Sewer
Remedial Action Objective
Eliminating direct contact with the contaminated surface and subsurface soil,
storm sewer sediments, and the wastewater pond sediments by excavating and
treating those wastes prior to disposing in an approved off-site facility.
Reducing contaminant levels in the concrete pads by testing to determine whether
they are characteristic hazardous waste, scarification and treatment of the top one
inch of the pads if they are a characteristic waste, removal of any residual soil,
and off-site disposal of the remaining portion of the pads.
Eliminating direct contact with the water in the wastewater pond by treating and
discharging of the water a determined during the remedial design (RD).
Reducing the contaminant levels in the existing concrete storm sewer by cleaning
and slip-lining the sewer.
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Optimization Review Report - Saunders Supply Company Superfund Site
Medium
Groundwater
Groundwater
(from ROD
Amendment)
Remedial Action Objective
Evaluate the protectiveness of the remedial action through groundwater
monitoring and implement institutional controls to prevent further migration of
the PCP plume and use of the Columbia and Yorktown aquifers as a source of
potable water.
Continue to operate and maintain the system to collect and treat groundwater to
prevent further migration of the contamination and until PCP cleanup levels have
reached the MCL of 1 (ig/L.
3.2
Selected Remedies
The ROD initially identified soils and sediments in the wastewater ponds as the primary threat to human
health and selected soil removal, treatment, and offsite disposal as the remedy. Remedial alternatives did
not include long-term groundwater treatment because it was believed that the contaminated groundwater
was limited to on-site and mass reduction of contaminant through soil excavation would reduce
groundwater concentrations (EPA, 1991b). The 1991 ROD included only monitoring of groundwater, but
was amended in 1996 to add a P&T system to control the migration of contaminants off-site towards
Godwin's Millpond. Table 6 lists the components of the selected remedy in the order presented in the
ROD Amendment (EPA, 1996).
Table 6: Remedy Components Documented in the ROD Amendment
Remedy Component
Target
Medium
Description
Excavation, Treatment,
and Disposal of Pond
Sediments
Pond
Sediment
Excavation and offsite incineration and disposal of the
K001 sediments (wood treatment sludge) from the
wastewater pond and the former earthen separation pond.
Excavation, Treatment,
and Disposal, of Soil
and Sewer Sediments
Soils and
Storm Sewer
Sediment
Excavation and offsite incineration and disposal of the
Site soils and the sediments from the storm sewer.
Groundwater
Columbia
Aquifer and
Yorktown
Aquifer
Operation and maintenance of the groundwater collection
and treatment system constructed under EPA's time
critical removal action to prevent further migration of
Site contaminants and achieve PCP cleanup levels of 1
(ig/L; includes treatment of the groundwater collected
during the dewatering process prior to excavating the
soil. Treatment may be either onsite or offsite.
Concrete Pad
Concrete Pad
Removal of the top one inch of the stained areas of the
concrete pad, solidification and offsite disposal of the
removed material, and removal of the concrete pad in the
area requiring soil excavation with onsite disposal.
Cleaning and Lining of
the Storm Sewer
Storm Sewer
Sediment
The existing 8-inch concrete storm sewer will be cleaned
of all debris and sediment and lined with a flexible high-
density polyethylene pipe (the sewer was inspected with
a closed circuit television camera during the remedial
design).
Groundwater
Monitoring
Columbia
Aquifer and
Yorktown
Aquifer
Groundwater monitoring will be performed for thirty
years to ascertain that the remedy is protective of human
health and the environment.
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Optimization Review Report - Saunders Supply Company Superfund Site
Remedy Component
Target
Medium
Description
Institutional Controls
Columbia
Aquifer and
Yorktown
Aquifer
Institutional controls will be implemented to restrict
access to the contaminated groundwater under the Site
and to prevent movement of the PCP offsite. The
institutional controls include deed restrictions on the Site
to prohibit using either the Columbia aquifer or the
Yorktown aquifer as a source of groundwater and
restrictions on offsite groundwater extraction.
3.3 Current Completion Strategy
The ROD and ROD Amendment (EPA 1991b, 1996) set forth short-term expectations that the exposure
to contaminated groundwater will be prevented, that plume migration will be controlled, and that source
area soil will be remediated (including excavation and removal of any principal threat wastes). The ROD
Amendment also sets the long-term expectation that the groundwater remedy will require less than 10
years to restore the aquifers. The Fund-lead remedy was transferred to the Commonwealth of Virginia in
July 2009, 10 years after the P&T system was determined to be operational and functional (O&F).
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Optimization Review Report - Saunders Supply Company Superfund Site
4.0
DATA GAPS
This section presents key data gaps in site characterization and a review of the current remedial strategy
based on discussions during the optimization review meeting and document review.
4.1 Data Gaps in Characterization
During the site meeting and document review, several key data gaps and uncertainties in the Saunders
Supply Site CSM were identified. Table 7 prioritizes data gaps identified that may reduce the
effectiveness of remedial actions.
Table 7: Identified Data Gaps
Medium
Data Gap
Implications
Groundwater
- source area
Unknown distribution and mass
of PCP in source area
Source area contaminant mass may act as a long
term continuing source to downgradient areas.
Groundwater
Extent of contamination
The extent of contamination in the down gradient
and cross-gradient areas west of the recovery wells
is not well understood and may not be effectively
captured and removed by the existing groundwater
extraction and treatment system.
Groundwater
Potential for groundwater
leakage from Columbia to
Yorktown through irrigation
well
Contaminants in the Columbia aquifer may be
moving through the Kelly irrigation well into lower
aquifer if the well was not properly sealed.
Surface Water
The interaction of the
groundwater and surface water
among the aquifers,
intermittent stream, and
Godwin's Millpond is not well
understood.
Potential for groundwater discharge from Columbia
and upper Yorktown to intermittent stream and
Godwin's Millpond.
4.2 Review of Current Remedial Strategy
The optimization review team and site team discussed the current strategy for groundwater cleanup at the
site. The existing P&T system was installed during 1998 as part of a time critical removal action to collect
and treat the groundwater to prevent further migration of the contamination, but the 1996 ROD
Amendment indicated that the system would be operated until groundwater cleanup levels were achieved.
In its 18 years of operation, the P&T system has not effectively reduced groundwater concentrations in
the aquifer. The remedy currently includes four extraction wells, three located along the axis of the plume
(RW-1, RW-3, and RW-4) and one in the former wood treatment area (RW-5) (see Figures 2 and 4 in
Appendix B). The extraction system delivers groundwater to the treatment building to remove
contaminants (PCP, arsenic, and chromium) prior to effluent discharge to the storm drain located along
Godwin Boulevard (State Route 10/32). The sequence of groundwater treatment is currently as follows:
Groundwater is mixed with a solution of sodium carbonate in reaction tank T-l and mixed with
air from an air compressor to allow for the precipitation of iron and other heavy metals.
Water flows from the reaction tank to the settling tank (T-2), which collects precipitated iron and
other solids that settle.
Water flows through four bag filters to remove solids.
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Optimization Review Report - Sounders Supply Company Superfund Site
Two granular activated carbon (GAC) vessels arranged in two series (Cl and C2) are used to
remove PCP.
Effluent from the GAC units is collected in a holding tank (T-3) prior to its discharge to the storm
drain.
While the current treatment system is adequate in meeting discharge criteria, the remedy has not
succeeded in reducing contaminant concentrations in the aquifer and reaching groundwater cleanup levels
(MCLs). Therefore, the optimization review team agrees that a revised strategy must be implemented that
focuses on contaminant mass removal and aquifer restoration. The current remedy is not removing
contaminant mass at a rate that would allow the site to reach completion in a reasonable timeframe. As
such, a revised remedial approach is necessary that involves a combination of: additional source area and
plume characterization, a better understanding of groundwater/surface water interactions, improved
remedy effectiveness, P&T system refinements, additional remedy performance monitoring, and well-
defined remedy operation completion criteria.
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Optimization Review Report - Sounders Supply Company Superfund Site
5.0 FINDINGS AND RECOMMENDATIONS
The findings and recommendations provided by the optimization review team address the site
characterization data gaps identified in Section 4.1 and the remedial strategy data gaps in Section 4.2.
Recommendations are provided for site characterization, remedial action objectives, remedy
effectiveness, performance monitoring, and the development of remedy completion criteria.
Relative to the ROD, the recommended strategy ensures effectiveness of groundwater containment, raises
the priority of mass removal to facilitate groundwater restoration, and emphasizes performance
monitoring and timely shutdown of remedy components. Collectively, the recommendations help fill
critical data gaps and satisfy the RAOs in a cost-efficient manner.
5.1 Recommendations to Characterize the Site for Remedy Refinement
Benefits of Implementing Section
5.1 Recommendations
High resolution site
characterization of groundwater
will help focus remedial activities
on areas that will improve mass
removal.
Characterization of contaminant
mass in place provides a basis for
performance monitoring of
ongoing and potential new
remedial activities.
The optimization review team assigns a high priority to
source area characterization because aquifer restoration will
be difficult and lengthy unless sufficient contaminant mass is
located and removed. The optimization review team
recommends a more comprehensive evaluation of the
contaminant mass distribution and transport pathways to
improve mass removal efficiency.
The primary source of PCP and metals contamination was
contaminated soil and wastewater ponds located on north
end of the Saunders property. These known sources were
removed but more information on the current distribution of
PCP and metals contamination in the source area as well as
portions of the downgradient extent of contamination would
be beneficial in order to determine if additional source
remediation is necessary.
Recommendation 5.1.1: Delineate current extent of potential source and groundwater contamination
at the source area
Finding: Contaminants are present in, and migrate through, the permeable sands of the Columbia aquifer,
as evidenced by the downgradient concentrations of PCP in shallow monitoring wells. Recovery well
RW-5, located near the former source area, accounts for most of the annual contaminant mass removal
which indicates that the groundwater in the area has a high contaminant load. During the RI, PCP
concentrations between 10,000 |o,g/L and 19,000 |o,g/L were detected in the source area. Elevated
concentrations of carrier oil constituents were not detected, suggesting that the petroleum hydrocarbons
initially increased the mobility of PCP in groundwater, but were subsequently degraded (E&E, 1991).
PCP may be held in the fine grained sands and silts of the Columbia aquifer and upper part of the
Yorktown Confining Unit immediately underlying the Columbia and act as a continuing source.
Understanding the total contaminant mass and distribution in the source area is necessary to refine the
remedy and develop performance monitoring criteria.
The site team stated that during the installation of recovery well RW-5 in 2010, an investigation was
performed and soil and/or groundwater samples were collected. Unfortunately, the optimization review
team was unable to locate this documentation.
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Optimization Review Report - Sounders Supply Company Superfund Site
Recommendations: The optimization review team recommends PCP and metals characterization of the
source area for both the Columbia aquifer and the Yorktown Confining Unit. The objective would be to
characterize the distribution of the mass in the aquifer and develop an estimate of the contaminant mass
remaining in the subsurface.
The optimization review team recommends using EPA's strategic sampling strategy of high resolution
site characterization (HRSC) in the source area. Transect-based HRSC investigations will better define
the more highly contaminated plume core in relation to the less contaminated dissolved phase plume
when oriented accurately in their geologic settings.
HRSC data will help accurately depict the footprint of subsurface contamination in order to apply targeted
actions, should they be deemed to be necessary. The optimization review team recommends initiating the
HRSC in the vicinity of RW-5 on the Saunders property using an east-west oriented transects near the
Former Wastewater Pond source area and Former Wood Treating Process Area. Real time data, combined
with site action levels, can be used to identify the western edge of the transect. If data support further
characterization, parallel transects can be made further north, within the Kelly property. A second
location for an east-west HRSC transect is recommended on the Kelly property between the fence and
MW-7S/8D to characterize the Conical Burn Pit source area and Former Wood Treating Process Area. In
each of these locations, discrete soil and groundwater samples should be collected for PCP, arsenic, and
chromium analysis in the Columbia and upper Yorktown Confining Unit to assess contaminant mass and
transport. The approximate location of these transects is shown in Figure 6 in Appendix B.
On-site field laboratory with gas chromatograph/mass spectrometry (GC/MS) capability could be used for
analysis of PCP, but may be costly for a small field program. Analysis of arsenic and chromium would
require an off-site laboratory.
The optimization review team also recommends collecting high resolution data of aquifer properties near
the Former Wastewater Pond, Conical Burn Pit, and Former Wood Treating Process Area
(hydrostratigraphic sampling) to obtain relative permeability data in order to define potential areas of
contaminant storage and better understand the differences in flow characteristics of the Columbia and
Yorktown Confining Unit. Hydraulic conductivity data will support contaminant transport analysis and
mass removal remedy evaluation.
Based on discussions during the optimization review, the optimization review team estimates that
additional investigation of the source area with onsite laboratory analysis for PCP and offsite laboratory
analysis for arsenic and chromium would cost approximately $50,000, if performed in conjunction with
other site investigation work recommended in this optimization.
Recommendation 5.1.2: Delineate current extent of contamination in groundwater in the western
portion of the downgradient plume area for both the Columbia aquifer and the Yorktown Confining
Unit
Finding: Groundwater flow at the site is generally to the north with a slight westerly component.
Groundwater from the Columbia aquifer breaks out in seeps on the eastern bank of the unnamed
intermittent stream. Monitoring wells MW-9S and MW-10D are the only groundwater monitoring points
on the west side of the plume. Over the last five years of monitoring, concentrations of PCP have varied
between non-detect (<0.1 ng/L) and 11.9 |o,g/L in these wells with no apparent upward or downward
trend. Samples from the deep well (MW-10D) exceed the MCL of 1 ng/L more often than the shallow
well (MW-9S).
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Optimization Review Report - Sounders Supply Company Superfund Site
Several well screens, including MW-8D and MW-12D, appear to intersect both the Columbia and upper
portion of the Yorktown Confining Unit. Groundwater samples collected from these wells likely originate
from the most permeable flow zones in the Columbia, and may not reflect the conditions in the Yorktown
Confining Unit. Wells that intersect both hydrostratigraphic units should be abandoned and may need to
be replaced with wells with shorter well screens in discrete units, using the results of the HRSC described
in this recommendation.
Recommendations: The optimization review team recommends applying an HRSC approach for
characterizing the extent of contamination to the south and north of MW-9S and MW-10D well pair to
better understand the extent of contamination and the nature of contaminant transport between the
Columba aquifer and the upper Yorktown Confining Unit.
Direct-push HRSC methods can be used to identify the edge of the groundwater plume exceeding MCLs
and to select the locations and depths for shallow and deep well screens for new permanent monitoring
wells. Samples at the proposed new location should show low to non-detect levels of PCP and metals in
both the shallow and deep zones. The new well locations should be sampled at the same frequency as all
other monitoring wells to confirm delineation of the plume.
The optimization review team also recommends HRSC of the downgradient plume area (see Figure 6 in
Appendix B) to support estimation of contaminant mass, build a detailed conceptual model of the plume,
and evaluate the effectiveness of potential refinements to the remedy described below in
Recommendation 5.3. Boring logs from continuous direct-push technology (DPT) profiling of the
Columbia aquifer during the 2005 Deep Groundwater Investigation (COM, 2005) shows thick layers of
sand locally broken by lenses of fat clay. The 10-foot well screens in the existing monitoring wells, and
the 15 foot screens in the existing recovery wells expose large sections of the Columbia aquifer and lesser
parts of the upper Yorktown Confining Unit, and may contain stratified flow zones separated by less
permeable zones. Contaminant flow may be concentrated in thin permeable zones and the existing screens
may not provide fine enough resolution to focus removal on the preferential transport zones for PCP and
metals. High resolution groundwater contaminant and hydraulic profiling can be used to increase the
vertical resolution of contaminant distribution.
Based on discussions during the optimization review, the optimization review team estimates that
additional investigation of the downgradient plume area would cost approximately $50,000 if this work is
performed in conjunction with the source area characterization described in Recommendation 5.1.1. The
annual cost for monitoring new wells installed following the recommended characterization (assumed to
be two well pairs, or four wells) would be approximately $3,600 per year.
Recommendation 5.1.3: Better characterization of groundwater, stream, and Godwin's Millpond
interaction
Finding: Godwin's Millpond is the downgradient discharge point for groundwater from the Columbia
aquifer and the small amount of flow that may come from the Yorktown Confining Unit. Godwin's
Millpond is also the discharge point for surface water from the intermittent stream, including any seepage
from the Columbia aquifer breakouts observed in the stream bank. Only one deep monitoring well (MW-
19D) adjacent to Godwin's Millpond is currently sampled to assess potential contaminant migration into
the pond. According to the site team, approximately 1.7 million gallons of water per day are withdrawn
from Godwin's Millpond to supply drinking water for the City of Suffolk, Virginia. The optimization
review team found no information on the hydrologic effects of these large water supply withdrawals on
contaminant movement and believes that additional hydrologic and chemical characterization is needed to
ensure plume migration remedial objectives will continue to be met.
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Optimization Review Report - Sounders Supply Company Superfund Site
Recommendations: Specifically, the optimization review team recommends:
Installing a shallow monitoring well screened in the Columbia aquifer to characterize
groundwater quality at the downgradient discharge location near Godwin's Millpond. This new
shallow well would complement the existing deep monitoring well MW-19D and serve as an
additional sentinel well. The HRSC data from the additional characterization described in
Recommendations 5.1.1 and 5.1.2 should be used to assist in determining the screened interval
depth of the new well.
Characterizing the location, flow, and contaminant content of seeps along the banks of the
intermittent stream to determine the amount and chemical nature of groundwater from the
Columbia aquifer entering the stream. Thermal imaging is a potential method to map the location
of seeps. Placement of piezometers in the stream bed and adjacent areas to develop groundwater
flow nets can also be used detect discharge points. Direct sampling of seeps with larger flow rates
may be possible; otherwise pore-water sampling devices may be required. Passive diffusion bag
(PDB) samplers are not likely to be effective for PCP.
Determining if withdrawal of water from Godwin's Millpond affects the groundwater flow
direction or rate. Extracting large quantities of water from the downgradient aquifer could
accelerate groundwater flow and draw contaminants further downgradient, towards the pond. The
optimization review team found no documentation on the rate or frequency of extraction, the
location of the extraction point, or the hydrologic effects of extraction on the Saunders site
conditions. This information may be available from county or city offices. If the data are not
available, hydrologic modeling should be used to estimate the effects of pumping.
Based on discussions during the optimization review, the optimization review team estimates that
additional investigation of the groundwater, stream, and Godwin's Millpond interaction would cost
approximately $20,000 (excluding hydrologic modeling). Installation of a shallow well would cost
approximately $5,000 and add $500 per year to annual monitoring costs.
5.2 Recommendations to Confirm Exposure Assumptions
Finding: The RAOs for the site are based on exposure
assumptions and associated data collected prior to 1991.
Recommendations: It should be confirmed that the RAOs are
consistent with current site conditions and exposed
populations. The optimization review team supports the
following activities to ensure future actions are aligned with
RAOs that reflect current conditions and exposures:
Benefits of Implementing Section
5.2 Recommendations
Confirming the exposure
assumptions will help ensure the
optimization recommendations
address current conditions.
Confirm and document that no on-site or off-site
private wells (drinking or irrigation) have been installed since the previous survey in 1991.
Verify and document the closure of the Kelly irrigation well and that it is not acting as a potential
vertical conduit for transfer of contaminants from the Columbia aquifer to lower
hydrostratigraphic units.
Include city sampling data in the annual site O&M and Monitoring reports to confirm that
Godwin's Millpond is free of site-related contamination.
Based on discussions during the optimization review, the optimization review team estimates that
verification of the items above would cost approximately $5,000, and revision to the sampling and
reporting to incorporate city sampling data would cost approximately $500 per year.
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Optimization Review Report - Sounders Supply Company Superfund Site
5.3 Recommendations for Improving Remedy Effectiveness
Finding: The current remedy is designed to contain
groundwater so that it does not migrate to the public
drinking water supply (Godwin's Millpond) along with
reducing concentrations of PCP in the underlying aquifers.
The capture zone analysis presented in the 2006
Hydrologic Analysis Report (CDM, 2006b), prepared prior
to the installation of RW-5, concluded that the majority of
the PCP plume and all of the arsenic plume are within the
capture zone, but elevated chromium concentrations at
MW-9S may not be within the capture zone (Figure 4-5 in
Appendix B). The lack of current groundwater data south
and west of MW-9 raises uncertainty of the extent of the
complete capture of the plume in the area.
Over the last three years, a small mass of COCs has been
removed by the P&T system (see Table 8, from annual
O&M reports). Prior to 2012, COC mass removal rates
were similar; the total quantity of PCP removed from all of
the wells through the December 2007 quarterly monitoring
event is 0.64 Ibs (CDM, 2007). Based on this removal rate,
it would likely take decades to reach MCLs and site closure.
Benefits of Implementing Section 5.3
Recommendations
Improving the extraction rate of the
existing pumping system would
increase mass removal while
ensuring groundwater containment.
Updating the CSM with high
resolution data will provide a better
target for focused remedial
activities.
Applying a combined remedy
approach will increase mass removal
and reduce time to site closure.
Without additional mass removal,
the current system is not expected to
reach cleanup goals for many
decades, if it can be achieved at all.
Table 8: Contaminant Mass Removed 2012 - 2015
Year
2012-2013
2013-2014
2014-2015
Total
Mass of PCP
Removed (Ib)
0.011
0.06
1.142
1.213
Mass of Arsenic
Removed (Ib)
0.003
0.006
0.0117
0.0207
Mass of Chromium
Removed (Ib)
0.0025
0.007
0.0049
0.0144
Recommendations: The optimization review team supports a sequenced approach to improve the
effectiveness of the current remedy and consideration of other treatment technologies to enhance the mass
removal.
Following the additional characterization described in Section 5.1, perform an updated capture
zone analysis to evaluate if the current groundwater P&T system is effectively capturing the
lateral and vertical extent of contamination. The prior capture zone analysis (CDM, 2006b) was
completed before the installation of extraction well RW-5 and may not be representative of
current plume conditions and extraction well pumping rates.
If the updated capture zone analysis indicates that the current P&T system is not adequately
containing the contaminant plume, improve the extraction rate and treatment system capacity of
the current groundwater P&T system (as described in Recommendations 5.4.1 and 5.4.2) to
ensure adequate plume containment and to maximize contaminant mass removal.
Update the CSM to reflect the current distribution and mass of contaminants in the source area
and downgradient area using HRSC characterization data.
Update the CSM to reflect findings of the hydrologic characterization including the relationship
of the groundwater, intermittent stream, and Godwin's Millpond.
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Optimization Review Report - Sounders Supply Company Superfund Site
Evaluate potential in-situ technologies to supplement the existing groundwater extraction system
that will improve the mass removal rate of PCP and metals.
o Using HRSC data, identify the highest concentration areas for source treatment.
o In Situ Chemical Oxidation (permanganate or persulfate) and In Situ Enhanced
Bioremediation have shown to be successful in reducing PCP mass at other wood treating
sites over relatively short periods. Site-specific testing of these technologies would be
required to determine the most effective treatment for the site conditions, and to assess
whether the in-situ technologies would have any unintended consequences on the
remedy, such as mobilizing metals into the groundwater.
Use a combined remedy approach to reduce contaminant mass while continuing to provide
containment. For example, continue to use the existing P&T system to provide plume control and
containment, while conducting targeted in-situ treatment of high concentration zones within the
source area to reduce contaminant mass.
Costs for improvements to the treatment system are addressed in Recommendations 5.4.1 and 5.4.2. Costs
for updating the CSM with additional characterization data are addressed in Recommendations 5.1.1,
5.1.2, and 5.1.3. Updating the capture zone analysis is estimated to cost approximately $10,000.
Evaluating potential options for enhancing the existing system performance is estimated to cost
approximately $30,000. The optimization review team cannot estimate the cost of applying additional
remedies at the site until the further site characterization is conducted.
5.4 Recommendations for Current Extraction and Treatment System Improvements
Benefits of Implementing Section
5.4 Recommendations
Improve hydraulic control/
containment of plume
Increase contaminant mass
removal and shorten time to site
closure
The additional site characterization recommendations
presented in Section 5.1, if implemented, are likely to take
some time. Therefore, to ensure that adequate containment of
the contaminant plume is achieved during this timeframe, the
remedy should continue to include operation of the P&T
system. Many of the system improvements presented below
(including extraction well redevelopment) are a standard
component of an effective O&M program, and as such,
should be implemented regardless of whether the other
recommendations are implemented. However, other specific recommendation presented below (including
the replacement or relocation of extraction wells) should be determined only after additional
characterization and an updated capture zone analysis have been completed.
Recommendation 5.4.1: Improve extraction well pumping rates to increase plume capture and
maximize contaminant mass removal
Finding: Over the last several years, the extraction system has had a total combined pumping rate (from
all four extraction wells, RW-1, RW-2, RW-4, and RW-5) of less than approximately 0.75 gallons per
minute (gpm). The total volume extracted during the last few years is summarized in Table 9.
Table 9: Groundwater Extracted by P&T System from 2012 to 2015
Period
July 2014 -June 2015
July 2013 -June 2014
July 2012 -June 2013
Gallons Extracted/
Year
391,002
85,972
135,224
Gallons/Month
32,584
7,164
11,269
Gallons/Minute
0.74
0.16
0.26
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Optimization Review Report - Sounders Supply Company Superfund Site
Data tables presented in the 2005 O&M and Monitoring Report (CDM, 2006a) indicate that combined
flow rates from four wells during the 1998 to 2005 timeframe ranged from approximately 25,000 to
80,000 gallons per month (or approximately 0.57 to 1.82 gpm), significantly higher than current rates.
Extraction well RW-5, the newest well, was installed in January 2010 in an effort to increase the recovery
of PCP near the former wood treating process area. Since its installation, RW-5 has consistently
accounted for the greatest volume of pumping (ranging from 39- to 87-percent of the total) and the
highest rate of contaminant mass removal of all four wells. The extraction well located the farthest
downgradient at the edge of the plume, RW-4, has accounted for the second highest volume (ranging
from 4- to 32-percent of the total). The other two extraction wells, RW-1 and RW-2, have had the lowest
pumping rates and have accounted for generally less than 5- to 15-percent of the total pumping.
Extraction pumps are routinely cleaned (every month or every other month) by system operators to
prevent iron-scale buildup and fouling of the impellers. However, despite the procedures outlined in the
2003 O&M Manual (CDM, 2003), routine extraction well redevelopment has not been performed, at least
not since 2009 when VDEQ assumed responsibility of O&M activities. The reduced yields that have been
observed from extraction wells are likely due to iron fouling of the well screens and the gravel pack
surrounding the well. In this case, while the pump will produce at the desired rate, more frequent pump
shut downs will occur due to triggering low water level conditions, thus lowering the overall volume of
water produced from the well.
In addition to fouling and clogging of the extraction wells themselves, iron-scale has also likely reduced
the effective diameter of the piping that conveys water from the well to the treatment system building.
Iron-scale buildup in this piping may also be limiting the amount of water that can be pumped to and
treated by the system.
Recommendations: The updated capture zone analysis described in Recommendation 5.3 should be
evaluated to determine whether containment is adequate based on current day plume configuration and
extraction well pumping rates. If it is not, the optimization review team recommends improving the
effectiveness of the extraction system. In order to maintain adequate plume capture and maximize
contaminant mass removal, the following activities should be completed.
Redevelop all four existing extraction wells. Redevelopment can be accomplished using a
mechanical surge and pump method. If fouling and clogging are significant, chemical
redevelopment methods (for example, muriatic acid) may be necessary. Continuously reevaluate
extraction well pumping rates and perform routine extraction well redevelopment to sustain
higher yields.
If extraction well redevelopment efforts do not improve yields, abandon and replace the under-
performing extraction wells with new extraction wells. Prior to replacing existing extraction wells
in their current position, consider relocating the new wells to areas with higher observed
contaminant concentrations based on the additional characterization activities suggested in
OO
Recommendation 5.1.1 to improve mass removal. Consider the use of horizontal extraction wells
if the characterization (Recommendations 5.1.1 and 5.1.2) identifies favorable conditions such as
continuous elongated areas of elevated groundwater concentrations.
Replace piping that conveys pumped water from the extraction well vaults to the treatment
system building.
The optimization review team estimates that the extraction well redevelopment, extraction well
replacement, and pipe replacement would cost approximately $35,000, and an increase of approximately
$5,000 per year in routine O&M.
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Recommendation 5.4.2: Improve treatment system capacity
Finding: At its current pumping rates, the treatment system is effectively reducing contaminant
concentrations to below required discharge limits for PCP, arsenic, and chromium. While many of the
system components are original (including reaction tank T-l, settling tank T-2, bag filters, and holding
tank T-3), they continue to perform adequately. The GAC canisters and their associated tubing/piping
were replaced in June 2015 and are in excellent condition. Three dual-media filters that were part of the
originally constructed treatment system are no longer in use, and have been replaced by bag filters, which
are in good condition and operate effectively.
However, like the extraction wells, many of the treatment system components and related piping are
operating below their design flow rates and have not been maintained to allow for maximum flow, if
needed. Based on operator observations, there is significant iron-scale build up inside the piping between
several components of the system. Additionally, there is significant sedimentation and sludge buildup in
the soda ash reaction tank (T-l), the settling tank (T-2), and possibly the effluent holding tank (T-3). If
the extraction well redevelopment and replacement efforts discussed in Recommendations 5.4.1 are
successful, it is possible that additional treatment capacity will be needed to meet the increased flow rates.
Recommendations: In order to improve the treatment system capacity, the optimization review team
recommends completing the following activities.
Evaluate the degree of iron-scale buildup in treatment system manifolds and piping and replace
any piping that is heavily scaled.
Evaluate the degree of scaling and fouling of flow meters, sensors, and valves. Clean or replace
impacted meters, sensors, and values.
Implement routine maintenance program to flush and clean lines, meters, sensors, and valves to
minimize future scaling.
Gauge depth of sedimentation in the soda ash reaction tank (T-l), the settling tank (T-2), and
holding tank (T-3). If excessive accumulation of sedimentation and sludge is present, test and
dispose of sediment and sludge using a properly licensed waste handler.
The optimization review team estimates that the treatment system improvements would cost
approximately $20,000, and an increase of approximately $2,500 per year in routine O&M.
5.5 Recommendations for Remedy Performance Monitoring
Recommendation 5.5.1: Update remedy performance monitoring
Finding: Based on a recommendation from a 2005
optimization review of the Saunders site (EPA, 2005), the
frequency of monitoring well and treatment system sampling
was reduced to semi-annual and quarterly, respectively.
Given the current pumping and mass removal rates of the
system, this frequency is adequate. Additionally, the current
annual O&M and monitoring reports provide an adequate
assessment of various remedy performance metrics,
including: groundwater elevation contour maps to assess
hydraulic control and capture of the plume in the shallow
and deep aquifers; contaminant concentration data and associated trend plots to assess overall aquifer
Benefits of Implementing Section
5.5 Recommendations
Cost-effective monitoring
program and performance metrics
to optimize remedy operation and
shutdown remedy components in a
timely manner.
17
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Optimization Review Report - Sounders Supply Company Superfund Site
restoration; calculations to evaluate contaminant removal efficiencies of the treatment system; and mass
recovery and removal calculations to assess overall aquifer restoration. These data should continue to be
collected and reported.
Recommendations: To ensure that the performance monitoring procedures remain relevant to the remedy
as it continues to operate into the future, the optimization review team recommends completing the
following activities.
Update the O&M Manual. The O&M Manual being used by the site operator was developed in
2003, and several changes to the monitoring and O&M program have been made since then,
including sampling frequency reduction, discontinued use of the media filters, and installation of
new GAC canisters. Additional updates should be made to reflect any new updates to the remedy
based on recommendations implemented as a result of this optimization review. Having an up-to-
date O&M Manual will ensure that the proper performance monitoring will be conducted into the
future to adequately assess remedy progress and ultimate site closure.
Include concentration contour plots for PCP, arsenic, and chromium for the shallow and deep
intervals of the aquifer in the annual O&M and monitoring reports to better illustrates the plume
footprint. These figures will allow for a more robust assessment of plume capture as well as
concentration trends overtime.
Collect quarterly effluent samples after the second GAC canister to ensure that the treated water
being discharged to the storm drain located along Godwin Boulevard (State Route 10/32) meets
required discharge limits. These data will also be helpful in evaluating potential contaminant
breakthrough in the GAC canisters, particularly if flow and mass removal rates improve as a
result of other implemented recommendations from in this report.
Additional recommended remedy performance metrics include:
Estimate total sorbed mass in the source area and compare with mass removal by P&T, or other
selected remedies.
Statistical trend tests should be performed for groundwater data and included in five-year
reviews. Trend tests can be performed for datasets with four or more sampling events. A non-
parametric test for trend, such as the Mann-Kendall test, is recommended to track groundwater
response to remedial actions. Semi-annual to annual sampling will generate datasets of sufficient
size to develop trends. Historical concentration data can be mined to determine the variability and
confidence intervals around concentration estimates.
A mass discharge or mass flux approach to assessing remedial performance can be effective in
demonstrating plume control and reduction in total mass (Farhat, Newell et al. 2006; ITRC 2010).
Initial mass estimates can be made using new site characterization data collected as part of
Recommendation 5.1.1 and 5.1.2. Mass flux calculations can be performed during the five-year
review process and compared with pre-remedy estimates to evaluate the efficacy of source
treatment.
Many software and analytical tools are available to evaluate trends and mass distribution in
groundwater plumes. Recommendations provided above are intended to guide discussion of more
specific remedy performance evaluation tools and methods. Each remedy and remedy stage
should have detailed data quality objectives (DQOs), data management strategies, and a data
analysis plan when the remedies are designed and implemented.
Updating the O&M Manual and preparing the necessary data sets and calculation systems for mass and
statistical analysis will require an initial cost of approximately $13,000. The incremental costs for the
additional recommended remedy performance monitoring activities are estimated to be $7,000 per year.
18
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Optimization Review Report - Sounders Supply Company Superfund Site
Remedy performance monitoring involves using routine groundwater sampling results from existing and
recommended new wells, and the analyses described above.
5.6 Recommendation for Establishing Remedy Operation Completion Criteria
Findings: Establishing remedy operation completion criteria,
or performance metrics, for each remedy component can
help reduce the risk of operating a remedy past the point of
effectiveness. Completion criteria are remedy-specific
recommendations developed to evaluate the cost and benefit
of continued operation of each remedy component.
Benefits of Implementing Section
5.6 Recommendations
Criteria to help avoid operating
long-term remedies longer than
necessary.
Recommendations: Completion criteria for each remedy
component should be developed by the site team. The optimization review team provides the following
suggestions by remedy component for consideration by the site team.
P&T system for plume control and containment
o The completion criterion for a specific extraction zone (such as source area and
downgradient plume) for the P&T hydraulic control component could be based on the
PCP, arsenic, and chromium concentrations and mass discharge at that extraction zone,
relative to a predetermined threshold below which unacceptable plume migration will not
occur.
P&T system for aquifer restoration
o The completion criterion for the P&T aquifer restoration component could be based on
observable decreasing PCP, arsenic, and chromium concentration trends at monitoring
wells within the source area and the downgradient plume, and a decreasing plume
footprint over time. The data from each monitoring well should be evaluated to confirm
that PCP, arsenic, and chromium concentrations are reduced to below the MCL cleanup
goals. Existing EPA guidance and tools that might be used to develop or evaluate such
completion criteria include:
Groundwater Road Map (http://semspub .epa. gov/src/document/HQ/174480).
Groundwater Remedy Completion Strategy
Oittp://semspub.epa.gov/src/document/HQ/100000021). and
Groundwater Statistics Tool Oittp://semspub.epa.gov/src/document/HQ/174595
and https://semspub.epa.gov/work/HQ/l 89718.pdf
Alternative (non-P&T) remedy, if deemed necessary based on additional characterization and
delineation of the source area and downgradient plume. Completion criterion for an alternative
remedy could include several possibilities, depending largely on the specific technology that is
implemented. These could include: a contaminant mass removal and reduction rates in the target
treatment zone that is small relative to the initial mass removal rate at a start-up of the alternative
remedy; a mass removal rate relative to the current mass flux from the source area to the
dissolved plume; or concentration trends in monitoring wells located within the target treatment
area.
Additional study by the site team would be needed to help define reasonable completion criteria for the
various remedy components to help avoid unnecessary operation of these remedies. Changes to the
remedy would likely require a remedy modification, such as an ESD or amended ROD, as determined by
lead agency.
19
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Optimization Review Report - Sounders Supply Company Superfund Site
5.7 Recommendations for Green Remediation and Environmental Footprint Reduction
Findings: The current P&T system is a relatively small operation that does not require a significant
amount of electrical power to operate. The four extraction wells use 1A horsepower submersible pumps
that operate intermittently, and the pumps within the treatment system (chemical feed pump, transfer
pumps, effluent pump) also operate intermittently in a batch treatment process. Additionally, site
operators indicate that very little water is used to support O&M of the system. In fact, treated effluent is
typically used for routine maintenance activities, such as cleaning pumps and flow meters, cleaning the
bag filters, and backwashing the GAC canisters.
The P&T system operator indicated that a renewable energy vendor visited the site in the recent past to
evaluate the feasibility of installing solar photovoltaics (PV) to power the P&T system. However, given
the relatively low electricity demand of the P&T system, the capital and operating cost of the solar PV
system outweighed the potential benefits that it might provide to the site. Therefore, this alternative
renewable energy source was not implemented.
Recommendations: Due to the relatively small environmental footprint of the current P&T system, no
specific recommendations have been provided for green remediation or environmental footprint
reduction. However, several of the above optimization recommendations have the potential to reduce the
remedy footprint by either streamlining the treatment process or reducing the likelihood of operating a
remedy component past the point of measureable benefit in achieving the RAOs. Additionally,
implementation of the recommendations could result in achievement of restoration in a shorter time
frame, and thus reducing the remedies overall environmental footprint.
20
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Optimization Review Report - Saunders Supply Company Superfund Site
Table 10: Recommendation Summary
Recommendation
5.1.1: Delineate current extent of
potential source and groundwater
contamination at the source area.
5.1.2: Delineate current extent of
contamination in groundwater in
the western portion of the
downgradient plume area for both
the Columbia aquifer and the
Yorktown Confining Unit
5.1.3: Better characterization of
groundwater, stream, and
Godwin's Millpond interaction
5.2 Confirm Exposure
Assumptions
5.3 Improving Remedy
Effectiveness
5.4.1 Improve extraction well
pumping rates to increase plume
capture and maximize contaminant
mass removal
5.4.2 Improve treatment system
capacity
5.5.1 Update Remedy
Performance Monitoring
5.6: Establishing Remedy
Operation Completion Criteria
Remedy
Effectiveness
X
X
X
X
X
X
X
X
Cost Reduction
X
X
X
X
X
Technical
Improvement
X
X
X
X
X
X
X
Site Closure
X
X
X
X
X
X
Environmental
Footprint Reduction
X
Capital
Cost
$50,000
$50,000
$25,000
$5,000
$40,000
$35,000
$20,000
$13,000
N/A
Change in
Annual Cost
N/A
$3,600
$500
$500
N/A
$5,000
$2,500
$7,000
N/A
21
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APPENDIX A
REFERENCES
-------
Optimization Review Report - Sounders Supply Company Superfund Site
APPENDIX A
REFERENCES
CDM Federal Programs Corporation (2003). Groundwater Extraction and Treatment System Operations
and Maintenance Manual, Sounders Supply Company Superfund Site, Chuckatuck, Virginia. U.S.
Environmental Protection Agency Region 3. June 30, 2003.
CDM Federal Programs Corporation (2005). Draft Technical Memorandum Deep Groundwater
Investigiaton, Sounders Supply Company Superfund Site, Chuckatuck, Virginia. U.S.
Environmental Protection Agency Region 3. February 28, 2005.
CDM Federal Programs Corporation (2006a). Annual Operation and Maintenance (O&M) and
Monitoring Report 2005, Sounders Supply Company Superfund Site, Chuckatuck, Virginia. U.S.
Environmental Protection Agency Region 3. February 26, 2006.
CDM Federal Programs Corporation (2006b). Draft Hydrogeological Analysis Report for the Sounders
Supply Company Superfund Site, Chuckatuck, Virginia. U.S. Environmental Protection Agency
Region 3. December 18, 2006.
Ecology & Environment (E&E) (1991). Remedial Investigation Report Sounders Supply Company. U.S.
Environmental Protection Agency Region 3. May 1991.
EPA (1991a). Feasibility Study Report Sounders Supply Company. U.S. Environmental Protection
Agency Region 3.
EPA (1991b). Record of Decision Sounders Supply Company. U.S. Environmental Protection Agency
Region 3.
EPA (1996). Record of Decision Amednment Sounders Supply Company. U.S. Environmental Protection
Agency Region 3
EPA (2005). Final Report, Pilot Region-Based Optimization Program for Fund-Lead Sites in EPA Region
3, Site Optimization Tracker: Sounders Supply Company Superfund Site Chuckatuck, Virginia.
ecord of Decision Sounders Supply Company. U.S. Environmental Protection Agency Region 3.
December 30, 2005.
EPA (2014). Third Five Year Report for Sounders Supply Company Superfund Site. U.S. Environmental
Protection Agency Region 3
Farhat, S. K., C. J. Newell, et al. (2006). Mass Flux Toolkit To Evaluate Groundwater Impacts,
Attenuation, and Remediation Alternatives. Battelle's Fifth International Conference on
Remediation of Chlorinated and Recalcitrant Compounds, Monterrey, CA, Battelle Press.
Interstate Technology Regulatory Council (ITRC) (2010). Use and Measurement of Mass Flux and Mass
Discharge, Interstate Technology Regulatory Council: 154.
A-l
-------
APPENDIX B
SUPPORTING FIGURES FROM EXISTING DOCUMENTS
-------
Russnow-Kane
Installed borino/
monitoring welM 982
SOURCE: Ecology and Environment, he. 1991.
Figure 4-1
CROSS SECTION LOCATIONS
-------
OW-1- MW-8-D
RW Pivot Point
MW-1-S MW-2-D
Ground Surface Profile
DcHijteWelCasmg
Grout around well casing
BentonleSeal
Well Screen
Columbia Aqitfer-
daysihbnses
Sand
Construction Unknown
Potentiometrtc Surface
(Yorktown Aquifer,
October 1990 gauging)
WWW Uwel (CdumbW Aqufer
OdoOer 1 990 gauging)
sand vrtn shell Iragments
* Blank pattern used for Columbia Aquifer applies only to area beta* ground surface profile
SOURCE: Ecology and Environment, Inc. 1991.
Figure 4~2a
CROSS SECTION A TO A'
PAGE1 OF 2
-------
MW-8-D
Pivot POM MW-7-S
45
40
35 -
30-
25
20,
15
10
5
0
RK-4
MW-11-S MW-12-D
Road MW-19-D
Ground Surface Profile
KEY:
rand and asphalt
Columbia AquKer**
fine to coaree sands,
some sJ Its
Cohimbia Aquler-
daysitt lenses
Columbia Aqulw-
nMnhvyday
Confining Clay Layer -
between aquter unis
Sandy ImsawWibi
corthing layw
Yoriiown Aquifer-
sand with shea fragments
Well Casing
Double Wei Casing
Or out around well casing
Bentonke Seal
Well Screen
BentorttVGnxrt
Sand
Conatructiofi Unknown
PotBrrtcmeirlc Surface
(YofKlown AquifBf.
October 1990 gaugino)
Water Lavel (Columbia Aqulfef,
October 1990 gaufllnfl)
Blank pattern used for Columbia Aquifer applies only to area below
ground surface profile
Godwin's Millpond
Water Level \
SCALE (10xVJ_)
0 SO Feet
A'
NW
-45
_ .40
- 35
-30
- 25
_ 20
- 15
- 10
- 5
- 0
-5
SOUHCE: Ecology and EnvlranmMt, he. 1991.
Figure 4-2 b
CROSS SECTION A TO A'
PAGE 2 OF 2
-------
RW-3
RW-4
!
:
Cross-Section Location
RW-1
RW-2
RW-4
RW-3
Columbia Aquifer
Fine-Grained 30
Deposits
Estimated Capture Zone
Yorktown Confining Unit
Cross-Section Showing Capture Zone, Flow and PCP Contours
Horizontal Scale: 1" = approx. 90ft
Elevation in Feet NGVD 1929
Notes:
1. Contours shown for July 2006 PCP concentrations
2. Vertical exaggeration = 5
Saunders Supply Site
Chuckatuck, Virginia
Figure 6-1
Conceptual Model
-------
F:\PROJECT_FILES_RAC_liriJ233D37_SauiKlefSiOISi3tlBamlheTtirDUOlOirtZ.niia
Legend
ฎ Extraction Wells
0- Monitoring Wells
Buildings Onsite
Stream
Note: Shaded Area Shows
Lateral Extent of Fine-Grain ed
Columbia Deposits
Profile View of Capture Zone
Vertical Exaggeration = 5
Saunders Supply Site
Chuckatuck, Virginia
Figure 4-5
Estimated Capture Zone
Using Three-Dimentional Visualization
-------
Godwin's
Millpond
N
*&
Q
&*
Propane
Tanks
Well ID
MW-8D
MW-10D
MW-12D
MW-19D
MW-21D
MW-23D
TOG (ft)
42.77
37.44
34.56
21.46
39.98
34.9
DTW (ft)
11.56
8.90
6.50
2.18
10.48
7.58
GW Elev (ft)
31.51
28.59
27.99
19.67
29.60
27.28
A
Nursery
I-MW-22S \
FMW-12D
HVIW-11S
RW-3 JV
-0-MW-21^
&-MW-2Q
RW-2*t
-K&MW-IOD
'
MW-74^W-8D
Former
Wastewater
Pond
Former
Earthen
Separation^
Pnnd
Former
Wood
Treating
Drocess
Area
\
ฐr
o 8-
lc
^x
)rmer
Storage
Tanks
oo
Monitoring Well
Recovery Well
Abandoned Well
Groundwater Elevation
Contour (ft amsl)
Road
Ditch
Fence/Property Line
Creek
Former Use Area
Former Tank
Propane Tank
Building
Concrete Pad
Pond
720
Source: Base map provided by COM
A
Environmental Alliance, Inc.
8215 Hermitage Road -Henrico, Virginia 23228
Phone: (877) 234-1141 - Fax: (302) 234-1535
Saunders Supply Company
Superfund Site
Chuckatuck, Virginia
Groundwater Elevation Contour Map -
Deep Zone -April 2015
DESIGNED BY
MRP
APPROVED BY.
DRAWN BY;
SKJ
'ROJECTNO.:
2G32
-------
Godwin's
Millpond ,
'*ป"ฃ"--
a fec.
ฉ/*/>
'<$>
D
Propane
Tanks
\
/
t
i
r
Well ID
MW-7S
MW-9S
MW-11S
MW-20S
MW-22S
RW-1
RW-2
RV\M
RW-5
TOO (ft)
42.67
37.24
35.42
39.99
35.03
38.83
36.85
32.35
40.10
DTW(ft)
6.70
9.18
6.18
10.40
7.40
12.58
12.01
5.80
10.33
GW Elev (ft)
36.47
28.06
28.89
29.69
27.54
26.91
25.11
19.97
27.39
Kelly
Nursery
Monitoring Well
Recovery Well
Abandoned Well
Fence/Property Line
Former
Wastewater
Pond
reating
rocess
Area
Propane Tank
Former
Earthen
Separation^
Pond
Saunders Supply Company
Superfund Site
Chuckatuck, Virginia
Groundwater Elevation Contour Map -
Shallow Zone - April 2015
Source; Base map provided by COM
Environmental Alliance, Inc.
8215 Hermitage Road -Heruico, Virginia 23228
Phone: (877)234-1141 - Fax: (302)234-1535
-------
Propane
Tanks
Kelly
Nursery
tfer'MW-22S
^
Arsenic: ND
Chromium: ND
MW-11S
PCP: ND
Arsenic: ND
Chromium: ND|
RW-3S
MW-2CS
PCP: 0.182
Arsenic: ND
Chromium: ND
RW-2
PCP: 9.80
Arsenic: ND
(jnromium: NU
MW-7S
PCP: 0.719
Antimony: 20.4
Arsenic: 1,440
Barium: 76.2
Chromium: 69.9
Cobalt: ND
Copper: 4.18 J
Cyanide: ND
Lead: ND
Manganese: 2.35 J
Nickel: 1.06 J
Selenium: 1.15 J
Zinc: 21
RW-1
PCP: 7.05
Arsenic: ND
Chromium: ND
Groundwa
Treatment
Building
PCP: 425 (396)
Arsenic: ND (ND)
Chromium: NO (ND)
Former
Wastewater
Pond
\
t-ormer
Wood
"reating
rocess
Area
rnier
Storage
Former
Earthen
Separatio
Pond
Shallow Well
5 Recovery Well
5 Abandoned Well
Road
Ditch
Fence/Property Line
Creek
Former Use Area
Former Tank
Propane Tank
Building
Former
Wastewater
Separation
Tanks
Wood
Storage
Area
! Concrete Pad
Pond
Saunders Supply Company
SipGrfund Site
Chuckatuck, Virginia
Groundwater COG Concentrations in
Shallow Zone Groundwater - April 2015
--o:.'.''ce: Base map provided by COM
Environmental Alliance. Inc
Cl5 Hermiuje RoaJ
Notes:
l concentrations reported in
micrograms per liter ((jg/L),
- J = Estimated Value
-ND = Non-Detect
- Duplicate samples shown in parenthesis
- Bolded values are greater
than or equal to the MCL
- Only dissolved concentrations shown
for Arsenic and Chromium
Downgradient HRSCTransect
Source Area HRSCTransect
-------
Godwin's
Millpond
Propane
Tanks
Kelly
Nursery
POP: 16.8
Arsenic: ND
Chromium: ND
POP: 1.23
Arsenic: 3.35 J
Chromium: ND
Leaend
Deep Well
Shallow Well
Recovery Well
ffi- Abandoned Well
Former Use Area
Former Tank
Propane Tank
Building
PCP: 1.58
Arsenic: 861
Benzo (A) Pyrene: ND
Benzo (B) Flouranthene: ND
Benzo (G,H,I) Perylene: ND
Benzo (K) Flouranthene: ND
Chromium: 30.4
Dibenzo (A,H) Anthracene: ND
Indeno (1,2,3-CD) Pyrene: ND
Ground water
Treatment
Building
RW-
! Concrete Pad
Road
Wastewater
Pond
Wood
Treating
Former
Earthen
Separation-
Pond
Saunders Supply Company
Superfund Site
Chuckatuck, Virginia
Notes:
-All concentrations reported in
micrograms per liter (ng/L).
- J = Estimated Value
- ND = Non-Detect
- Bolded values are greater than or equal
totheMCL
- Only Dissolved concentrations shown for
Arsenic and Chromium unless otherwise noted
Groundwater COG Concentrations in
Deep Zone Groundwater - October 2014
Source: Base map provided by COM
Environmental Alliance, Inc.
8215 Hermitage Road - Henrico, Virginia 23228
Phone: (877)234-1141 - Fax: (302)234-1535
-------
APPENDIX C
SITE PHOTOGRAPHS
C-l
-------
Photo 1. Treatment system building (December 1, 2015)
Photo 2. GAC, Soda Ash Reaction Tank (T-1), and Settling Tank (T-2) (December 1, 2015)
C-2
-------
Photo 3. GAC, Extraction Well Control Panel, and Pump Level Indicators (December 1, 2015)
Photo 4. Extraction Well Influent Manifold and Flow Meters (December 1, 2015)
C-3
-------
Photo 5. New Fiberglass GAC Canisters (December 1, 2015)
Photo 6. View Looking North from the Treatment System Building (December 1, 2015)
C-4
-------
Photo 7. View along Western Edge of Site, Looking South (December 1, 2015)
~\\ ฃ*
Photo 8. Extraction Well RW-1 Vault (December 1, 2015)
C-5
-------
::,
dte^itift
Photo 9. View of Intermittent Stream along Western Edge of Site (December 1, 2015)
Photo 10. View of Drainage Ditch along Eastern Edge of Site (December 1, 2015)
C-6
-------
Photo 11. View of Northern Portion of Site, Looking North (December 1,2015)
Photo 12. View of Godwin's Millpond, Looking North (December 1, 2015)
C-7
------- |