FIFTH FIVE-YEAR REVIEW REPORT FOR
SULLIVAN'S LEDGE SUPERFUND SITE
BRISTOL COUNTY, MASSACHUSETTS
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Prepared by
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Region 1
Boston, Massachusetts
D DV A KI Digitally signed by BRYAN
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OLSON
Bryan Olson, Director Date
Superfund and Emergency Management Division
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Table of Contents
LIST OF ABBREVIATIONS & ACRONYMS 2
I. INTRODUCTION 4
Site Background 4
FIVE-YEAR REVIEW SUMMARY FORM 5
II. RESPONSE ACTION SUMMARY 8
Basis for Taking Action 8
Response Actions 8
Status of Implementation 11
Institutional Controls 14
Figure 3: Institutional Controls Map 16
Systems Operations/Operation & Maintenance (O&M) 17
III. PROGRESS SINCE THE PREVIOUS REVIEW 19
IV. FIVE-YEAR REVIEW PROCESS 20
Community Notification. Community Involvement and Site Interviews 20
Data Review 21
Site Inspection 26
V. TECHNICAL ASSESSMENT 27
QUESTION A: Is the remedy functioning as intended by the decision documents'.' 27
QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels and RAOs used at the time of the
remedy selection still valid'.' 28
QUESTION C: Has any other information come to light that could call into question the protectiveness of the
remedy'.' 35
VI. ISSUES/RECOMMENDATIONS 36
Other Findings 37
VII. PROTECTIVENESS STATEMENT 38
VIII. NEXT REVIEW 38
APPENDIX A - REFERENCE LIST A-1
APPENDIX B - SITE CHRONOLOGY B-l
APPENDIX C - 1989 ROD INDICATOR COMPOUNDS C-1
APPENDIX D - PMP MONITORING LOCATIONS D-l
APPENDIX E - PRESS RELEASE E-l
APPENDIX F - INTERVIEW FORMS F-l
APPENDIX G - DATA REVIEW FIGURES G-l
APPENDIX H - DATA REVIEW TABLES H-l
APPENDIX I - DATA TREND GRAPHS 1-1
APPENDIX J - SITE INSPECTION CHECKLIST J-l
APPENDIX K - SITE PHOTOGRAPHS K-l
APPENDIX L - EVALUATION OF SOIL CLEANUP LEVELS L-l
APPENDIX M - VISL CALCULATOR OUTPUT M-1
APPENDIX N - 2018 EPA MEMORANDUM N-l
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LIST OF ABBREVIATIONS & ACRONYMS
ALM
Adult Lead Methodology
ARAR
Applicable or Relevant and Appropriate Requirement
ATSDR
Agency for Toxic Substances and Disease Registry
AWQS
Ambient Water Quality Standard
BLL
Blood Lead Level
CASRN
Chemical Abstracts Service Registry Number
CERCLA
Comprehensive Environmental Response. Compensation, and Liability Act
CFR
Code of Federal Regulations
CIC
Community Involvement Coordinator
coc
Contaminant of Concern
DCE
1,1 -Dichloroethene
EPA
United States Environmental Protection Agency
ESD
Explanation of Significant Differences
ESV
Ecological Screening Value
FS
Feasibility Study
FYR
Five-Year Review
GERE
Grant of Environmental Restriction and Easement
GW-RBC
Groundwater Risk-Based Concentration
GWTP
Groundwater Treatment Plant
HFPO-DA
Hexafluoropropylene Oxide Dimer Acid
HHRA
Human Health Risk Assessment
HQ
Hazard Quotient
ICs
Institutional Controls
IRIS
Integrated Risk Information System
J
Estimated
LEL
Lower Explosive Limit
MassDEP
Massachusetts Department of Environmental Protection
MCL
Maximum Contaminant Level
MS
Microgram
(.ig/dL
Micrograms per Deciliter
ms/l
Micrograms per Liter
mg/kg
Milligrams per kilogram
mg/kg-day
Milligrams per Kilogram per Day
mg/L
Milligrams per Liter
MMCL
Massachusetts Maximum Contaminant Level
MRL
Minimal Risk Level
NCP
National Oil and Hazardous Substances Pollution Contingency Plan
ng/L
Nanograms per Liter
NPL
National Priorities List
O&M
Operation and Maintenance
OHHRRAF
OLEM's Human Health Regional Risk Assessment Forum
OLEM
Office of Land and Emergency Management
OU
Operable Unit
PAH
Polycyclic Aromatic Hydrocarbon
PCB
Polychlorinated Biphenyl
PFAS
Per- and Polyfluoroalkyl Substances
PFBA
Perfluorobutanoic Acid
PFBS
Perfluorobutane Sulfonic Acid
PFDA
Perfluorodecanoic Acid
PFHpA
Perfluorolleptanoic Acid
PFHxA
Perfluorohexanoic Acid
PFHxS
Perfluorohexane Sulfonate
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PFNA
Perfluorononanoic Acid
PFOA
Perfluorooctajioic Acid
PFOS
Perfluorooctane Sulfonic Acid
PMC
Project Management Committee
PMP
Performance Monitoring Plan
POC
Point of Compliance
PPm
Parts per Million
PPRTV
Provisional Peer Reviewed Toxicity Value
ppt
Parts per Trillion
PRP
Potentially Responsible Party
RAO
Remedial Action Objective
RfC
Reference Concentration
RfD
Reference Dose
RI
Remedial Investigation
ROD
Record of Decision
RPM
Remedial Project Manager
RSL
Regional Screening Level
SL
Screening Level
TAL
Total Analyte List
TBC
To Be Considered
TCE
Trichloroethene
TOC
Total Organic Carbon
UU/UE
Unlimited Use and Unrestricted Exposure
VI SL
Vapor Intrusion Screening Level
VOC
Volatile Organic Compound
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I. INTRODUCTION
The purpose of a five-year review (FYR) is to evaluate the implementation and performance of a remedy in order
to determine if the remedy is and will continue to be protective of human health and the environment. The
methods, findings and conclusions of reviews are documented in FYR reports such as this one. In addition. FYR
reports identify issues found during the review, if any, and document recommendations to address them.
The U.S. Environmental Protection Agency (EPA) is preparing this FYR pursuant to the Comprehensive
Environmental Response. Compensation, and Liability Act (CERCLA) Section 121. consistent with the National
Oil and Hazardous Substances Pollution Contingency Plan (NCP) (40 Code of Federal Regulations (CFR) Section
300.430(f)(4)(ii)), and considering EPA policy.
This is the fifth FYR for the Sullivan's Ledge Superfund Site (Site). The triggering action fortius statutory review
is the completion date of the previous FYR. The FYR has been prepared because hazardous substances, pollutants
or contaminants remain at the Site above levels that allow for unlimited use and unrestricted exposure (UU/UE).
The Site consists of two operable units (OlJs). OU1 consists of a 12-acre former disposal area and the adjacent
Unnamed Stream. OU2 consists of a 13-acre wetland called Middle Marsh and a 1.5-acre wetland area bordering
the Unnamed Stream, referred to as the Adjacent Wetlands. This FYR addresses both OlJs.
EPA remedial project manager (RPM) kimberly White led the FYR. Participants from EPA included community
involvement coordinator (CIC) Aaron Shaheen. human health risk assessor Courtney Carroll, ecological risk
assessor TaChalla Gibeau and site attorney Naomi King. Additional participants included Dorothy Allen from the
Massachusetts Department of Environmental Protection (MassDEP) and Johnny Zimmerman-Ward and Jill Billus
from EPA FYR contractor Skeo. The Project Management Committee (PMC) for the Sullivan's Ledge Site Group
(formed by the OU 1 Settling Defendants) and the City of New Bedford, a responsible party, were notified of the
initiation of the FYR. The review began on 2/6/2023.
Appendix A includes a list of documents reviewed for this FYR. Appendix B provides a chronology of site
events.
Site Background
The Site is in the city of New Bedford. Bristol County in southeastern Massachusetts (Figure 1). The Site consists
of a 12-acre former disposal area and the adjacent Unnamed Stream (OU 1) and affected wetland areas
downgradient of the former disposal area (OU2). The disposal area operated as a granite quarry from the 1840s
through 1921. The City of New Bedford acquired the property in 1935 and used the quarry pits for the disposal of
hazardous materials and other industrial and solid wastes through the 1970s. Waste disposal practices
contaminated groundwater, soil, surface water and sediment, primarily with volatile organic compounds (VOCs).
polychlorinated biphenyls (PCBs) and other hazardous substances.
Current Site features at OU 1 include the capped former disposal area and a groundwater treatment plant (GWTP)
for treatment of VOC- and PCB-impacted groundwater (Figure 2). A 1 76-megawatt photovoltaic solar array was
constructed on the cap in 2014. A fence surrounds the OU 1 property and limits unauthorized access. Hathaway
Road and the Whaling City Golf Club, owned by the City of New Bedford, are immediately north of the OU 1
property. The Interstate 195/Route 140 interchange is to the south. Commercial properties are to the east and
west. The Unnamed Stream flows from the former disposal area underneath Hathaway Road into the golf club.
OU2 is located within the Whaling City Golf Club. It consists of a 13-acre wetland called Middle Marsh and a
1.5-acre wetland area bordering the Unnamed Stream (400 feet upstream of the Middle Marsh), referred to as the
Adjacent Wetlands (Figure 2). OU2 is bounded on the east and west by fairways of the golf course and to the
south by Hathaway Road. Apponagansett Swamp is north of OU2.
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Groundwater beneath the Site occurs in overburden and shallow , intermediate and deep bedrock. Local
groundwater flow in the overburden and bedrock beneath the former disposal area is generally to the northeast
and north toward the dow ngradient wetland area, under non-pumping conditions. Groundw ater beneath the Site is
not used for drinking water. MassDEP issued a Final Groundwater Use and Value Determination for the Site in
March 2016. MassDEP assigned a medium use and value to the groundwater at the Site based on the non-drinking
water status of the groundw ater beneath, and in close proximity to. the Site, along with the nearby presence of
sensitive ecological receptors.
FIVE-YEAR REVIEW SUMMARY FORM
SITE IDEM II IC A I ION
Site Name: Sullivan's Ledge
EPA ID: MAD980731343
Region: 1
State: MA
City/County: New Bedford/Bristol
NPL Status: Final
Multiple OUs?
Yes
Has the site achieved construction completion?
Yes
REVIEW S I A 11 S
Lead agency: EPA
Author name: kimberly White
Author affiliation: EPA
Review period: 2/6/2023 - 9/6/2023
Date of site inspection: 3/22/2023
Type of rev iew: Statutory
Review number: 5
Triggering action date: 9/13/2018
Due date (fiveyears after triggering action date): 9/13/2023
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Sullivan's Ledge Superfund Site
City of New Bedford, Bristol County, Massachusetts
Disclaimer: This map and any boundary lines within the map are
approximate and subject to change The map is not a survey: The map
is for informational purposes only regarding EPA's response actions at
the Site. Map image is the intellectual property of Esri and is used herein
under license. Copyright © 2020 Esri and its licensors. All rights
reserved. Sources: Esri, Maxar and the 2008 FYR Report.
Last Modified: 6/9/2023
Figure 1: Site Vicinity Mai
ta pponaqa nsetuswa mp]
Whaling City:
Golf Club
Approximate Site
Boundary
Operable Unit
Boundary
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Figure 2: Detailed Site Map
lMansin
'Aaiacentj
W.etlancl*
reatment-
IBtiB
Capped Area
^3 Approximate Site Boundary
C3 Operable Unit Boundary
Fence Line and Approximate
Boundary of the Disposal
Area
g/2 Slurry Wall
C.v? Sedimentation Basin
— - Shallow Collection Trench
0 Recovery Well
N
A
Sullivan's Ledge Superfund Site
City of New Bedford, Bristol County, Massachusetts
1
500
1,000 Feet
Disclaimer: This map and any boundary lines within the map are
approximate and subject to change. The map is not a survey. The map
is for informational purposes only regarding EPA's response actions at
the Site. Map image Is the Intellectual property of Esri and is used
herein under license. Copyright © 2020 Esri and its licensors. All rights
reserved. Sources: Esri, Maxar, the 2018 FYR Report, the 2020 Post-
Suspension Performance Monitoring Event 1 Report and the 2022
Performance Monitoring Plan Event 6 Report.
^Skeo
Last Modified: 6/9/2023
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II. RESPONSE ACTION SUMMARY
Basis for Taking Action
In 1982, the Massachusetts Department of Public Works discovered the presence of electrical capacitors on site
during test borings for the construction of a proposed commuter parking lot. EPA performed an air monitoring
program of the greater New Bedford Area in 1982 and installed monitoring wells around the Site in 1983. Based,
in part, on the results of the studies. EPA added the Site to the Supcrfund program's National Priorities List (NPL)
in September 1984.
OU1
EPA completed a remedial investigation (Rl) and feasibility study (FS) for OU 1 in 1989. The results found high
concentrations of PCBs in surface soil, subsurface soil and sediments, and VOCs and inorganics in overburden,
shallow bedrock and deep bedrock groundwater. VOC contamination in groundwater increased with depth.
EPA's 1991 human health risk assessment (HHRA) for OlJ 1 estimated potential human health risks associated
with exposure to 59 indicator compounds in surface soils, sediments, air. surface water and groundwater.
Appendix C includes the list of indicator compounds from the 1989 Record of Decision (ROD). The risk
assessment assumed that access to the Site was restricted and the land was zoned as commercial but considered a
proposed future use of the Site as a soccer field. Human health risks were calculated for an adult and an older
child assuming occasional site visits and inadvertent contact with contaminated soil. PCBs and total polycyclic
aromatic hydrocarbons (PAHs) contributed most of the total carcinogenic risk from direct contact with surface
soils. Incidental ingestion of on-site soils by children was also a potential concern due to the lead in surface soil.
Though groundw ater was not a current source of drinking water, carcinogenic risks and noncarcinogenic hazards
from future ingestion of groundwater were estimated. Benzene, trichloroethene (TCE), vinyl chloride and PCBs
contributed over 99% of the total cancer risk. 1.1 -Dichloroethene (DCE) was the major contributor to the
noncarcinogenic groundwater hazard at the Site. Direct contact with contaminated sediments in the Unnamed
Stream was the highest carcinogenic risk contributor from exposure to sediments.
The ecological risk assessment indicated that a potential risk existed for aquatic organisms due to exposure to
contaminants in surface water of the Unnamed Stream. It was noted that risk to aquatic organisms due to PCB
exposure in water could not be accurately evaluated because the detection limit for PCBs (1.0 micrograms per
liter [jig/L]) was greater than the water quality criteria concentration (0.014 (.ig/L) at that time. However. PCB
exposure via water for aquatic organisms was likely in the Unnamed Stream and water hazards on the golf course
because of high levels of PCBs in sediment.
OU2
A supplemental Rl and FS to address Middle Marsh and the Adjacent Wetlands (OU2) on the golf course
property was completed in 1991. An HHRA for the OU2 area evaluated the potential risks to adult golfers,
maintenance workers and older children who may frequent the OU2 area. It evaluated exposures to contaminated
sediment/soil and surface water in Middle Marsh and the Adjacent Wetlands. Exposure to groundwater was not
evaluated in the 1991 HHRA because it was addressed under OU 1. The HHRA concluded that human exposures
to contaminants in Middle Marsh and the golf course/wetland area through current and anticipated future
pathways would not result in unacceptable risks or noncarcinogenic hazard.
The ecological risk assessment for OU2 completed in 1991 concluded that aquatic exposures and wetland/
terrestrial exposures to PC B-contam mated sediments in portions of the Middle Marsh presented an unacceptable
risk to biota. The findings of the ecological risk assessment were the primary basis for the OU2 remedial action.
Response Actions
Initial Response
In the early 1970s, a fire occurred on site, primarily involving tires disposed of in the quarry pits. Due to concern
regarding possible recurrence of such fires, efforts were made to regrade the Site to cover exposed refuse.
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In September 1984, EPA issued an Administrative Order to the City of New Bedford, requiring them to install a
fence around the former disposal area and post warning signs at the Site. The City of New Bedford completed the
actions in 1984.
Remedy Selection
EPA selected the remedy for OU1 in the Site's 1989 ROD and modified the OU1 remedy with three Explanations
of Significant Differences (ESDs) issued in 1995, 2000 and 2003. Table 1 presents the remedial action objectives
(RAOs) for the OU 1 remedial action and the selected remedy components for OU 1.
EPA selected the remedy for OU2 in the Site's 1991 ROD. Table 1 presents the RAOs for the OU2 remedial
action and the selected remedy components for OU2.
Table 1: QUI and OU2 RAOs and Remedy Components
OU
RAOs
Remedy Components
OU1
• Prevail or mitigate the conliiuicd release of
hazardous substances to the Unnamed Stream.
Middle Marsh and Apponagansett Swamp.
• Reduce risks to human health associated with
direct contact with or incidental ingestion of
contaminants in the surface and subsurface
soils.
• Reduce risks to animal and aquatic life
associated with the contaminated surface soils
and sediments.
• Reduce the volume, toxicity or mobility of the
hazardous contaminants.
• Maintain air quality at protective levels for on-
site workers and nearby residents during site
remediation.
• Reduce further migration of groundwater
contamination from the quarry pits in the upper
150 feet of the bedrock groundwater flow
system.
• Significantly reduce the mass of contaminants
in groundwater located in and immediately
adjacent to the quarry pits.
• Provide flushing of groundwater through the
pits to encourage continued removal of
contaminants at the Site.
• Minimize the threat posed to the environment
from contaminant migration in the groundwater
and surface water.
Source ('antral
• Excavation of contaminated soils and sediments from
the Unnamed Stream, water hazards on the golf course
property and other areas of OU 1 with placement in the
former disposal area. The 1989 ROD originally
required treatment of excavated soils and sediment, but
the 1995 ESD removed the treatment requirement.
• Construction of an impermeable cap over the former
disposal area.
Management of Migration
• Const met ion of a 750-foot-long underground culvert
adjacent to the disposal area cap and construction of a
new stream channel about the same length downstream
on the golf course property to recreate wetlands habitat
lost. The 1989 ROD originally called for the diversion
and lining of a portion of the U nnamcd Stream but the
2000 ESD replaced the requirement with the culvert.
• Construction and operation of an active groundwater
collection system composed of deep bedrock extraction
wells located close to the disposal pits.
• Construction of a passive underdrain collection system
(collection trench) at the top of the bedrock surface
along the eastern and northern boundaries of the
disposal area. The 2000 ESD modified this remedy
component to include construction of a 200-foot-long
slurry wall in place of part of the collection trench
along Hathaway Road.
• Groundwater treatment consisting of
oxidation/filtration for metals removal and
ultraviolet/ozonation for organics removal.
• Methane gas collection (required by the 2003 ESD).
Additional Measures
• Wetland restoration/enhancement of wetland areas
adversely impacted by the remedial action and
ancillary activities.
• Long-term environmental monitoring of on-site (i.e.,
the former disposal area property) and off-site (i.e.,
areas outside the former disposal area property)
overburden and bedrock groundwater and sediments in
the Unnamed Stream.
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OlJ
RAOs
Remedy Components
• Institutional controls designed to ensure that
groundwater in the zone of contamination will not be
used as a drinking water source and to ensure that any
use of the Site will not interfere with the effectiveness
of the cap.
OU2
• Reduce exposure of aquatic organisms to PCB-
contaminatcd pore water and sediments either
through direct contact or diet-related
bioaccumulation.
• Reduce exposure of terrestrial and wetland
species to PCB-contaminated sediment/soils
through direct contact or diet-related
bioaccumulation.
• Prevent or reduce releases of PCBs to the
Unnamed Stream and the Apponagansett
Swamp.
• Mitigate the impacts of remediation on
wetlands.
• Site preparation.
• Excavation of contaminated sediment/soils from
portions of Middle Marsh and the Adjacent Wetlands.
• Dcuatering of the excavated materials.
• Disposal of the materials beneath the cap that will be
constructed over portions of the former disposal area.
• Restoration of the affected wetlands.
• Institutional controls to prevent future residential use
of and to restrict access to Middle Marsh and the
Adjacent Wetlands.
• Long-term monitoring, including sediment/soil
monitoring and wetlands monitoring.
Cleanup Levels
Soil and Sediment
Tabic 2 summarizes the soil and sediment cleanup levels for OU1 and OU2, as identified in the 1989 ROD and
1991 ROD
Table 2: QUI and OU2 Soil and Sediment Cleanup Levels
Contaminants of
Concern (COC)
OU 1
OU2
Soil Within
Disposal
Area'
Soil Outside
the Disposal
Area'
Sediment1*'
Sediment/Soil in
Aquatic Areas in
Middle Marsh1'
Sediment/Soil in
Non-Aquatic Areas
in Middle Marsh
and Adjacent
Wetlands1'
Total
PCBs
50 mg/kg
10 mg/kg
20 ng/grain
carbon
20 ng/grain
carbon
15 mg/kg
Total Carcinogenic PAHs
30 mg/kg
—
—
—
—
Notes:
a) Human health risk-based level. The levels within the disposal area correspond to a 10~5 risk level under current site
use conditions and a 10~4 risk level under future site use conditions (soccer field). The level outside the disposal area is
based on a 10~5 risk. The cleanup level of 10 mg/kg is more stringent than the cleanup level for soil within the disposal
area because soils outside the disposal area arc located in unrestricted areas resulting in greater frequency of exposure.
In addition, soils outside the disposal area will not be covered with a cap.
b) Applies to sediment of the U nnained Stream, its tributaries and the golf course water hazards.
c) Ecological risk-based level.
ing/kg = milligrams per kilogram
Hg = microgram
- = cleanup goal not established for the area
Sources: 1989 ROD. pages 43 to 46, and 1991 ROD. pages 49 and 50.
Groundwater
The 1989 ROD identified VOCs and PCBs as contaminants of concern (COCs) in groundw ater; how ever, it did
not identify specific numeric cleanup goals for individual VOCs or PCBs in groundwater. The 1989 ROD states
that EPA considers it technically impracticable from an engineering perspective to clean up the contaminated
deep bedrock groundwater to maximum contaminant levels (MCLs) and Massachusetts drinking water standards.
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EPA waived the requirements to meet MCLs promulgated under the Safe Drinking Water Act, Massachusetts
drinking water standards and Massachusetts groundwater quality standards. Instead. EPA determined that the
cleanup goals for groundw ater are 1) the significant reduction of contaminant mass in bedrock groundw ater, and
2) the protection of surface water bodies. Both goals are addressed by the active and passive groundwater
collection systems at the Site.
Active Collection System Cleanup Levels
To address significant reduction in contaminant mass, two criteria are used to evaluate this goal: 1) a
concentration range of 1 milligram per liter (mg/L) to 10 mg/L (1,000 pg/L to 10,000 pg/L) total VOCs. and/or 2)
an asymptotic curve using groundw ater monitoring data indicating that significant concentration reductions are no
longer being achieved.1
Passive Collection System Cleanup Levels
The objective of the passive collection system is to prevent degradation of the Unnamed Stream by collecting
shallow contaminated groundwater. The 1989 ROD for OU1 states that the cleanup levels for the passive system
will be based on Ambient Water Quality Standards (AWQS) and the designated use of the receiving waters.
Status of Implementation
The section presents the remedial activities implemented at OlJ 1 and OU2. It also addresses recommendations
from a 2015/2016 EPA Optimization Review to improve the Site's remedy.
OU1
EPA reached a settlement agreement with 14 potentially responsible parties (PRPs), who formed the Sullivan's
Ledge Site Group. The parties agreed to construct the OU 1 remedy and perform operations and maintenance
(O&M) activities for 30 years. EPA approved the remedial design for the OU 1 remedy in June 1997. Remedial
construction began in March 1998 and finished in 2002 (except for the landfill gas extraction system, which was
added in 2004). In January 2003, EPA approved the March 2002 Sullivan's Ledge Superfund Site. Operable Unit
1. Remedial Construction Report. The follow ing remedial activities were completed for OU 1.
Site Preparation
Initial site activities included installation of fencing and gates, vegetation and debris clearing, demolition of a
former car wash ad jacent to the Site, grading, abandonment of monitoring wells within the former disposal area,
proof rolling (or ensuring there are no unstable areas), and placement of a temporary cover over parts of the Site
not scheduled for capping until a later phase.
Soil Excavation
Soil excavation took place in the bed of the Unnamed Stream and southern tributary, east bank (north and south of
the car wash) and east of the stream channel. About 2,100 cubic yards of soil/rock were removed and placed in
areas within the limits of the cap system. Post-excavation confirmation samples confirmed the cleanup criteria of
10 mg/kg PCBs had been met.
Diversion and Lining of the Unnamed Stream
This component of the remedy involved lining the Unnamed Stream east of the disposal area with a 72-inch pre-
stressed concrete cylinder pipe.
1 The Remedial Design/Action Plan Statement of Work for OU 1. Section V.C.4.a, states that for the Active Collection
System, "Consistent with the Consent Decree, the Groundwater Cleanup Standards must be demonstrated at all points of
compliance sampling locations for one year (four consecutive quarters) during the operation of the active extraction and
groundwater treatment systems before, upon approval of EPA. in consultation with the DEP. the active extraction system and
groundwater treatment systems can be shut off."
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Groundwater Collection and Treatment
The remedy component involved the construction of the active groundwater collection system and the passive
groundwater collection system (shallow collection trench, the slurry wall and two recovery wells), and the
GWTP.
The active groundwater collection system included installation of three bedrock recovery wells, conversion of
three existing bedrock monitoring wells to recovery wells and installation of associated infrastructure to connect
the recovery wells to the treatment plant. Figure 2 shows the locations of the six recovery wells.
The passive groundwater collection system consisted of a 660-foot-long shallow collection trench, manholes, a
pump station, a valve vault and associated piping. A portion of the passive collection system was substituted with
a slurry wall along the northern limits of the landfill cap and two recovery wells (called interim wells P-291 and
P-192) with pumps, controls and associated piping. The slurry wall was installed to a depth of 20 to 25 feet and a
width of 6 to 16 feet. However, due to debris encountered during excavation, the design goals were not met and
there was a gap between the bottom of the slurry wall and the top of the bedrock surface of up to 20 to 25 feet.
This resulted in recommendations to modify the collection trench, the cap and drainage collection features near
Hathaway Road. The top 3 feet of the slurry wall were also subsequently stabilized. As of 2015. the groundwater
from the shallow collection trench discharges either to the city sewer system or is pumped to the GWTP for
treatment prior to discharge to the city sewer system. Discharge of water from the passive collection trench to the
city sewer system provides a means for managing the water level in the trench and prevents off-site seepages.2
The GWTP began operating in December 1999. The ultraviolet/ozonation system was replaced with an air
stripper and liquid-phase activated carbon system in 2010, as was discussed in the 1989 ROD.3
In 2015 and 2016, EPA conducted an optimization review of the Site's remedy, with a focus on OU1. More
information on the review is in the Optimization Review section of this FYR Report. One of the recommendations
was to discontinue the active extraction system and conduct post-shutdown monitoring if conditions allow. At the
time, many of the point of compliance (POC) wells were meeting the performance standard (1,000 (.ig/L to 10,000
(.ig/L total VOCs). The purpose of the shutdown was to evaluate whether the GWTP is still needed and/or whether
an alternative remedial action would be more effective. EPA. MassDEP. the City of New Bedford and the PMC
signed an agreement for the shutdow n in December 2018 follow ing well repairs, as well as additional sampling
and evaluations to establish the conditions of the performance monitoring period during the shutdown.
In January 2020, the PMC submitted a Final Sullivan's Ledge Ground Water Treatment Plant Suspension Plan. It
provided the steps necessary to suspend operations and maintain the facility's equipment in such a condition that
will allow the facility to be returned to service, if necessary. In June 2020, the PMC submitted a Final Post-
Suspension Performance Monitoring Sampling Plan. The plan includes monitoring groundwater conditions inside
and outside the disposal area at various frequencies over seven years.
EPA and MassDEP initiated the temporary shutdown of the GWTP on July 23, 2020, and the system was turned
off the next day. The seven-year performance monitoring period began at that time. The sampling frequency at
each monitoring location in the program varies (quarterly, semiannually, annually and bi-annually). To date.
Events 1 through 7 have been performed. Post-suspension groundwater and pore water monitoring data collected
indicate total VOC concentrations in groundwater are increasing and migrating north towards the OU2 wetlands.
As a result, the GWTP was turned back on in May 2023. Recent data from the post-suspension performance
monitoring program are addressed in the Data Review section of this FY R Report.
2 The Ground Water Treatment Plant Operations & Maintenance Manual, dated May 2020, states that the discharge is
permitted by the Industrial Prctrcatment Permit issued by the Wastewater Division of the City of New Bedford.
3 The 1989 ROD for OU1 had contemplated the use of air stripping with granular activated carbon if the ultraviolent/
ozonation system was determined to be ineffective or significantly more costly.
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Cap Construction
Cap construction included installation of a gas venting system as well as installation of a geosynthetic clay liner,
flexible membrane cover and synthetic drainage layer, placement of a barrier protection material and placement of
topsoil. Work also included excavation and construction of the sedimentation basin, augmentation of the
Hathaway Road culvert, construction of run-on/run-off controls and access roads, and installation of the perimeter
fence and gates.
Wetlands Restoration/Enhancement
The restoration of affected wetlands in OU1 was conducted concurrently with OU2 wetlands restoration.
Sediment Treatment
About 7,600 cubic yards of sediment were excavated from a tributary of the Unnamed Stream and two golf course
hazards (Ponds A and B). Post-excavation confirmation samples met the cleanup criteria of 20 j.ig PCBs/gram
carbon. Excavated sediments were treated with stabilization agents (lime kiln dust and sand), moisture
conditioned and placed within the limits of the cap system.
Active Landfill Gas Extraction System
Active methane gas removal was not part of the remedy specified in the ROD for OU 1. However, landfill gas
monitoring conducted in 2001 and 2002 indicated that several gas monitoring wells had methane concentrations
that exceeded 25% of the lower explosive limit (LEL) for methane. A pilot gas extraction system was constructed
and ran until early 2004.
EPA issued an ESD in 2003 to add active landfill gas extraction as part of the OU 1 remedy. Installation of the
full-scale landfill gas collection system began in early 2004 and became operational in June 2004. Over time,
modifications have occurred to the system to address the accumulation of water/condensate in the lower leg of the
collection system and to apply additional vacuum to the eastern portion of the landfill cap.
In 2018, the PMC conducted a soil gas study to better understand the potential source of the methane near gas
monitoring well GM-18 where exceedances of the 25% LEL were observed. As discussed in an April 2019
Revised Soil Gas Evaluation Letter Report, there are several lines of evidence pointing to sources of methane
outside the cap. Recent data are discussed in the Data Review section of this FYR Report.
The landfill gas extraction system continues to operate and landfill gas monitoring continues quarterly.
OU2
EPA and MassDEP entered into a Consent Decree with AVX Corporation as the lead settling party, the City of
New Bedford and the OU 1 settling parties requiring them to implement the OU2 remedial action. The OU2
settling parties implemented the OU2 remedial action between 1999 and 2001.
Activities associated with soil/sediment removal, including any necessary dew ate ring, took place from April 1999
to September 2000. A total of 25,485 cubic yards of soil, sediment and debris was removed from Middle Marsh
and the Adjacent Wetlands. The soil/sediment was stabilized as needed and placed in the OU 1 disposal area, prior
to capping. Activities associated with wetlands restoration took place from July 1999 to September 2000. EPA
approved the August 2001 Final Remedial Construction Report. Sullivan's Ledge Superfund Site. Second
Operable Unit in January 2003. Long-term monitoring activities began at that time and are ongoing.
2015/2016 Optimization Review and Related Activities
EPA completed an optimization review of the Site's remedy in 2016. The optimization review included several
recommendations, which are addressed in more detail in the 2018 FYR Report. As a result of the
recommendations, the PMC or the City of New Bedford completed the following activities:
• Collected additional PCB groundw ater data (completed in 2016; collection of additional PCB data is
ongoing as part of the post-suspension monitoring program).
13
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• Discontinued the active extraction system and conducted post-shutdown monitoring (ongoing).
• Installed a gravity line from the passive system collection trench to the sewer system (completed in 2015).
• Addressed methane at the eastern property boundary. The PMC completed a study in June 2018 and
determined the methane may be from an off-site source. The PMC also connected gas vent GV-2 to the
landfill gas extraction system in September 2019.
• Conducted additional wetlands monitoring (completed in 2021).
In addition, the optimization review recommended that the treatment system be streamlined. The City of New-
Bedford evaluated the potential for streamlining the system in an informal pilot study in 2016 and determined that
operating costs would not be significantly reduced by modifying the system. The City did not plan to further
pursue an alternative treatment process at that time.
The optimization review also recommended that EPA/MassDEP revisit the ROD groundwater cleanup criteria for
the disposal pits and downgradient bedrock groundwater because the current cleanup standards do not address
know n risk at the Site. MassDEP issued a Final Groundwater Use and Value Determination for the Site in March
2016. MassDEP assigned a medium use and value to the groundwater at the Site based on the non-drinking water
status of the groundwater beneath and in close proximity to the Site, along with the nearby presence of sensitive
ecological receptors. The determination stated that potential vapor migration risk and impacts of groundwater
discharge to surface water at concentrations that could pose a significant risk to aquatic organisms should be
considered in evaluating risk and remedy performance. As an interim action. EPA developed groundw ater risk-
bascd concentrations (GW-RBCs) for protection of aquatic organisms in surface water that receives groundwater
from the Site.
Institutional Controls
The 1989 ROD for OU 1 called for institutional controls to ensure that groundw ater in the zone of contamination
will not be used as a drinking water source and to ensure that any use of the Site will not interfere with the
effectiveness of the cap. The 1991 ROD for OU2 called for institutional controls to prevent future residential use
of and to restrict access to Middle Marsh and the Adjacent Wetlands. Institutional controls have been
implemented at the Site in the form of a Grant of Environmental Restriction and Easement (GERE), recorded with
the Bristol County Registry of Deeds in May 2014. The institutional control instrument restricts residential,
commercial and industrial uses of the Site, allows use of the downgradient part of the Site as a golf course, and
requires any proposed use or activity be undertaken only with written approval of MassDEP.
The GERE stipulates that the City of New Bedford provide in January of each year an annual written compliance
report to MassDEP. with a copy to EPA. the OlJ 1 Settling Defendants and AVX. The annual compliance reports
are required to describe any permitted activities and uses during the preceding year, summarize the
implementation and status of any work plans required for those activities and uses, and certify that the City is in
compliance with the restrictions and any related work plans. MassDEP and EPA have not received annual
compliance reports from the City during this FYR period. Based on the FYR site inspection in March 2023, land
use was consistent with the permitted uses in the GERE, and there were no signs of disturbed soil or groundw ater
use. However, the City is required to submit the annual reports to certify compliance with the restrictions outlined
in the GERE.
Table 3 summarizes the area covered by the institutional control instrument as well as its restrictions. Figure 3
show s the area covered by the institutional control instrument. Based on review of Figure G-6 and Figure G-10 in
Appendix G. which show total VOC concentrations in groundwater in August 2022, groundwater contamination
extends outside the area covered by the institutional control instrument. In particular, shallow bedrock well MW-
4, located east of the OU 1 landfill and on a property used for self-storage, had a total VOC concentration of 1,790
(ig/L in 2022, which is generally consistent with concentrations observed prior to the GWTP shutdow n. TCE
contributed 940 (ig/L of the total VOCs (compared to the TCE MCL of 5 (ig/L). Although the property east of the
Site is connected to public water, additional institutional controls may be needed to restrict use of groundwater to
ensure long-term protectiveness.
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Table 3: Summary of Planned and/or Implemented Institutional Controls (ICs)
Media,
Engineered
Controls, and
Areas That Do
Not Support
IJU/UE Based
on Current
Conditions
ICs
Needed
ICs Called
for in the
Deeision
Documents
Impacted
Parcel(s)
IC
Objective
Title of IC
Instrument
Implemented
and Date (or
planned)
For Area 1 only:
• Restrict excavation, removal or
disposal of loam. peat, gravel,
sand rock or other mineral or
natural resource.
Groundwater,
the former
disposal area
(cap), Middle
Marsh and
Adjacent
Wetlands
sediment and
soil, remedial
components
Yes
Yes
Map 94, Lots 6,
9, 10 and 55
(Area 1, south
of Hathaway
Road)
Map 121. Lot
37 ( Area 2,
north of
Hathaway
Road)
For Area 1 and Area 2:
• Restrict extraction, excavation,
dewatering, consumption or
utilization of groundwater for any
purpose, including without
limitation, extraction for potable,
industrial, irrigation or
agricultural use.
• Restrict cultivation of crops for
human consumption.
• Restrict residential, commercial
or industrial activities or use.
• Restrict any use or activity that
would disturb or interfere with or
would be reasonably like to
disturb or interfere with, the
implementation, operation or
maintenance of the remedy.
Grant of
Environmental
Restriction and
Easement,
May 2014
Off-site
groundwater
Yes
Yes
Map 94, Lot 23
(parcel east of
OU 1)
9
Restrict use of groundwater for
any purpose.
To be
determined4
4 Additional monitoring data arc required to evaluate whether hydraulic containment has been reestablished with the restart of
the GWTP, which results in a reduction of contaminant concentrations over time in areas beyond the OU1 landfill. Further
evaluation may also be needed to: 1) delineate the eastern extent of contamination beyond MW-4, and 2) determine if
groundwater restrictions exist or need to be put in place to prevent access and use of the groundwater areas beyond the
landfill, although groundwater has been classified as not being a current or potential drinking water source area.
15
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Disclaimer: This map and any boundary lines within the map are
approximate and subject to change. The map is not a survey. The map is for
informational purposes only regarding EPA's response actions at the Site
Map image is the intellectual property of Esri and is used herein under
license. Copyright © 2020 Esri and its licensors. All rights reserved. Sources;
Esri, Maxar; Microsoft, Maxar, the City of New Bedford Parcel Viewer and the
Massachusetts Interactive Property Map, the 2013 FYR Report and the 2022
Performance Monitoring Plan Event 6 Report.
Sullivan's Ledge Superfund Site
City of New Bedford, Bristol County, Massachusetts
Last Modified: 6/9/2023
Figure 3: Institutional Controls Map
[Seelnset
iff" Map
Approximate Site Boundary
Operable Unit Boundary
Area Subject to 2014 Grant
of Environmental Restriction
and Easement (Area 1)
Area Subject to 2014 Grant
of Environmental Restriction
and Easement (Area 2)
Property Parcel
Well with Total VOCs >1,000
(jg/L, 2022
16
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Systems Operations/Operation & Maintenance (Q&M)
OU1
The City of New Bedford is responsible for implementing O&M activities at OU 1. The activities address O&M of
the landfill cap. the groundwater collection and treatment system, and the landfill gas extraction system. The
Sullivan's Ledge Site Group PMC implements the Site's groundwater, landfill gas. sediment and surface water
long-term monitoring program.
Landfill Cap and General Site Maintenance
The City of New Bedford performs monthly inspections of the landfill cap and site security features in accordance
with the 2002 Site Operations and Maintenance Manual. The City of New Bedford inspects the landfill cap for
signs of vegetative stress, burrowing animals, settlement, erosion, slope instability and other damage. They also
inspect three surveyed benchmarks, the access road, perimeter fence, gas vents, perimeter monitoring wells and
drainage controls for signs of damage or other issues. The 2002 Site Operations and Maintenance Manual also
requires inspections of the culverted portions of the Unnamed Stream every five years to ensure its integrity.
The City of New Bedford documents the results of the inspections in monthly reports submitted to EPA and
makes repairs as needed. Routine maintenance also includes mow ing and clearing of vegetation in drainage
swales. During this FYR period, damage to the perimeter fence was reported and repaired. As noted in the 2018
FYR Report, the Site's O&M Manual should be updated to reflect any changes in maintenance and monitoring
since the solar array was added to the cap in 2014.
Groundwater Collection and Treatment System
With EPA and MassDEP approval, the GWTP was shut dow n in July 2020 in accordance with the January 2020
Suspension Plan. Prior to that time, the City of New Bedford performed O&M of the groundwater collection and
treatment system in accordance with the 2000 Ground Water Treatment Plant Operation and Maintenance Manual
(O&M Manual) and its revisions. The O&M Manual was most recently updated in May 2020 in anticipation of
the GWTP shutdown but it did not address changes recommended in the 2018 FYR Report. When the GWTP was
operating, the City of New Bedford prepared monthly reports documenting effluent and other GWTP operating
data.
After the shutdown of the GWTP. the City of New Bedford performed maintenance and inspections of the GWTP
as required by the 2020 Suspension Plan. During the shutdown, the shallow collection trench continued to
discharge to the city's sewer system. The discharge is regulated by the city's industrial pretreatment performance
program (discharge permit number L-026A). The flow to the sewer is monitored at manhole MH-4. The Data
Review section of this FYR Report discusses recent monitoring results at MH-4.
With the anticipated restart of the GWTP. the City's industrial discharge permit L-026 was renewed and is
effective from April 1. 2023, to April 1. 2026.
Landfill Gas Extraction System
The City of New Bedford performs O&M of the landfill gas extraction system in accordance with the revised
2020 O&M Manual. The landfill gas extraction system's purpose is to remove landfill gases (methane) that may
accumulate beneath the cap. It is comprised of a blower to apply a vacuum, a knock out drum to collect any
accumulated moisture, control valves and instrumentation controls.
In accordance with the April 2019 Revised Soil Gas Evaluation Letter Report, gas vent GV-2 was connected to
the landfill gas extraction system during the week of September 16. 2019, and the differential pressure gauge and
monitoring port were installed during the week of September 30, 2019. The objectives of connecting GV-2 to the
landfill gas extraction system were to improve the radius of influence of the gas extraction system and to evaluate
further lines of evidence regarding the source of methane on the eastern side of the Site.
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Long-Term Surface Water, Sediment and Landfill Gas Monitoring
OU1 monitoring activities are conducted in accordance with the 2015 Surface Water. Sediment and Landfill Gas
Monitoring Field Sampling Plan, with results submitted to EPA follow ing the sampling events. The monitoring
program includes:
• Collection and analysis of surface water and sediment samples once every two years from five locations
within the Unnamed Stream.
• Quarterly monitoring of the perimeter gas monitoring wells and other locations for explosive gases and
hydrogen sulfide.
The Data Review section of this FYR Report presents recent results from the monitoring program.
Groundwater Monitoring
Prior to shutdown of the GWTP system in 2020, long-term groundwater monitoring took place quarterly through
2008 and then semiannually beginning in March 2009 in accordance with a 1996 Post-Construction
Environmental Monitoring Plan. In 2020, the long-term groundwater monitoring program was temporarily
suspended and replaced with the Post-Suspension Performance Monitoring Plan (PMP).
The PMP includes monitoring groundwater conditions inside and outside the disposal area during 12 sampling
events (i.e., Event 1 through Event 12) at various frequencies over seven years (quarterly for one year,
semiannually for two years, then annually for four years) subsequent to the temporary shutdown of the GWTP on
July 24, 2020. The sampling approach is presented in the June 2020 Sullivan's Ledge Superfund Site - Post-
Suspension Performance Monitoring Sampling Plan. It includes monitoring at the sample locations shown on
Figures D-l through D-5 in Appendix D. Samples are analyzed for VOCs and PCBs. The Data Review section of
this FYR Report presents recent results from the post-suspension PMP.
In May and June 2021, PMC contractors rehabilitated monitoring wells MW-8 and MW-10B and replaced the
bladder pump system at MW-17 to address issues previously identified at these wells during the PMP events. The
sampling frequency was also modified in 2021 to include quarterly sampling in year three due to changing
conditions of the groundwater. With the request to restart the GWTP. EPA and MassDEP also requested that an
updated monitoring and maintenance plan for the GWTP be provided.
OU2
Wetland Restoration Monitoring
Post-construction environmental monitoring and long-term wetlands monitoring activities are conducted in
accordance with the 1997 Wetland Restoration Plan and the 1999 Final Operation and Maintenance Plan for the
Second Operable Unit. Wetland monitoring is to be performed annually for the first three years after initial
restoration, during the fifth year, and once every five years thereafter. Previous wetland monitoring events took
place in 2001 through 2006, 2011 and 2017. Wetlands monitoring activities include monitoring of hummocks,
wetlands hydrology, soil development, and biological attributes including survival rates of planted trees and
shrubs, tree growth, vegetative diversity, plant community, and presence of the Mystic Valley Am phi pod.
The City of New Bedford led the most recent wetlands monitoring event in 2021, with results documented in the
2022 Environmental Monitoring Sampling and Results Report. It combined results for OU 1 and OU2 wetlands
monitoring. The Data Review section of this FYR Report summarizes recent results.
18
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III. PROGRESS SINCE THE PREVIOUS REVIEW
Tabic 4 includes the protectiveness determinations and statements from the 2018 FYR Report. Table 5 includes
the recommendations from the 2018 FYR Report and the current status of those recommendations.
Table 4: Protectiveness Determinations/Statements from the 2018 FYR Report
ou #
Protectiveness
Determination
Protectiveness Statement
OU1
Short-term Protective
The remedy for OU 1 is currently protective of human health and the environment
because the construction of the remedy is complete, operation and maintenance and
monitoring of the remedy is being performed, and institutional controls arc in place.
However, in order for the remedy to be protective in the long term, the following
actions need to be taken to ensure protectiveness: 1) evaluate monitoring data and
take actions necessary to ensure gas is not migrating beyond the boundaries of the
landfill; 2) enhance the monitoring network on the north side of Hathaway Road to
effectively monitor VOCs and PCBs beyond the disposal area; and 3) sample for
perfluorooctanoic acid (PFOA), perfluorooctanc sulfonic acid (PFOS) and
pcrfluorobutanc sulfonic acid (PFBS) contaminants.
OU2
Short-term Protective
The remedy for OU2 is currently protective of human health and the environment
because the construction of the remedy is complete, operation and maintenance and
monitoring of the remedy is being performed, and institutional controls arc in place.
However, in order for the remedy to be protective in the long term, continue to
monitor PCB concentrations in sediment and take corrective actions as needed to
ensure protectiveness of aquatic organisms.
Sitewide
Short-term Protective
The remedies for the Site arc protective in the short term, of human health and the
environment because the constmction of the remedy is complete, operation and
maintenance and monitoring of the remedy is being performed, and institutional
controls arc in place. However, in order for the remedy to be protective in the long
term, the following actions arc needed to ensure protectiveness: 1) evaluate
monitoring data and take actions necessary to ensure gas it is not migrating beyond
the boundaries of the landfill; 2) enhance the monitoring network on the north side
of Hathaway Road to effectively monitor VOCs and PCBs beyond the disposal area;
3) sample for PFOA. PFOS and PFBS contaminants; and 4) continue to monitor
PCB concentrations in sediment and take corrective actions as needed to ensure
protectiveness of aquatic organisms.
Table 5: Status of Recommendations from the 2018 FYR Report
OU#
Issue
Recommendation
Current
Status
Currcnt Implementation
Status Description
Completion
Date (if
applicable)
OU1
Elevated methane
levels were detected
along the eastern
property boundary
above 25% of the
lower explosive limit
(LEL) and is
therefore, not in
compliance with the
goals of the 2003
ESD and the Post-
Construction
Environmental
Monitoring Plan.
Review the findings of
the bar hole study and
conduct any necessary
evaluations to ensure
gas is not migrating
beyond the boundaries
of the landfill.
Implement a Corrective
Action Alternative
Analysis and modify
the landfill gas
monitoring, extraction
and collection system as
needed.
Completed
Gas vent GV-2 was
connected to the landfill
gas extraction system in
September 2019. Landfill
gas data on the eastern
boundary of the Site
continue to show methane
levels similar to before the
connection of GV-2 to the
system. Ongoing
monitoring indicates that
methane may be from a
source outside the landfill.
6/19/2020
19
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ou#
Issue
Recommendation
Current
Status
Current Implementation
Status Description
Completion
Date (if
applicable)
OU1
PCBs in groundwater
within the disposal
area may be mobile
and the current
monitoring network
may not be adequate
for monitoring PCBs.
Enhance the monitoring
network on the north
side of Hathaway Road
and conduct and sample
the new locations for
VOCs and PCBs.
Completed
Additional wells (including
multi-level well ECJ-5 near
the stream just north of
Hathaway Road) were
installed and samples
collected for VOC and
PCB analysis. Monitoring
is ongoing to evaluate the
mobility of PCBs.
9/30/2019
OU1
It is unknown if
PFBS. PFOA or
PFOS were released
at the Site.
Include per- and
polyfluoroalkyl
substances (PFAS) that
include PFOS. PFOS
and PFBS in an
upcoming groundwater
monitoring event to
determine if these
compounds are
associated with the Site.
Completed
EPA contractors sampled
for PFAS in March 2023.
PFAS were detected in
several groundwater
samples. Results arc
presented in the Data
Review section of this FYR
Report.
3/22/2023
OU2
Sediment monitoring
indicates some PCB
concentrations above
the total organic
carbon (TOC)
normalized cleanup
levels, which if
increased could
potentially pose a
risk to aquatic
organisms. The total
PCB concentrations
do not appear to be
increasing at this
time.
Collect the required
sediment samples and
implement corrective
actions as needed.
Completed
The City of New Bedford
completed a wetland
sampling event in 2021,
with results reported in the
2022 Environmental
Monitoring Sampling and
Results Report. Sullivan's
Ledge Superfund Site.
Operable Unit 2. Sediment
PCB results were below the
ROD cleanup goals.
Results arc presented in the
Data Review section of this
FYR Report.
8/25/2022
IV. FIVE-YEAR REVIEW PROCESS
Community Notification, Community Involvement and Site Interviews
EPA issued an online news release in January 2023 to announce that the FYR was underway. A copy of the news
release is included in Appendix E. The results of the review and the completed FYR Report will be made
available at EPA's site profile page at https://www.epa.gov/superfund/suHivansledge.
During the FYR process, interviews were conducted to document any perceived problems or successes with the
remedy that has been implemented to date. The results of these interviews are summarized below. Appendix F
includes the completed interview forms.
Dorothy Allen, the MassDEP project manager, noted that the GWTP is aging and needs continued repairs and
upgrades. Before shutdown it contained the plume and provided appropriate treatment. The active gas collection
system needs monitoring but captures most of the disposal area gas. Since the shutdown the groundwater
contamination has spread and no longer meets the performance standards. The treatment plant needs to restart and
to pump and treat an adequate volume of groundwater to draw back and once again contain the plume of
contamination. Ms. Allen also noted that the recent shutdown has demonstrated that the pump-and-treat remedy
20
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has not addressed the source of the contamination and that to contain the plume, it would need to operate for an
indeterminate period of time to meet the performance standards stipulated in the ROD. Further, it is not clear if
these standards are appropriate for the Site since they are not risk based. A re-examination of the performance
standards for the Site and design of a more appropriate long-term remedy is necessary. She noted that the Site is
in reuse as a golf course, wetland habitat and electricity generating location.
Marilyn Wade, a representative from Brown and Caldwell on behalf of the PMC, indicated that overall, the
remedy has been successful in reducing contaminant levels and restoring the wetland area. She noted that since
GWTP operations were suspended and the PMP began in 2020, groundwater VOC concentrations were observed
to increase in select wells. The most significant rebounding has occurred in the deep bedrock fracture zone. As a
result, the GWTP will be restarted. The anticipated resulting trend is a decrease in groundwater concentrations
with time as the recovery wells' cone of influence is reestablished and expands to provide containment. She also
noted that landfill gas monitoring events are consistent from quarter to quarter. While methane is detected at gas
monitoring well GM-18, multiple lines of evidence from collected data support that the methane is from an off-
site source. The PMC suggests reducing the landfill gas monitoring events from quarterly to semiannual.
James Costa. Superintendent of Wastewater for the City of New Bedford, is well informed of the Site's activities.
The City of New Bedford collects regular monitoring data for the GWTP when it is operational. O&M activities
have recently focused on repairs and maintenance for the facility to function properly. He noted that the plant
needs extensive repairs and part replacements due to its operational timeframe and would benefit from an
overhaul or replacement of the facility. He was unaware of changes to local regulations that might affect the
protectiveness of the Site's remedy. He was unaware of any changes in projected land use.
EPA's CIC also made several attempts by phone and once in person to speak with a representative of the Whaler
Inn and Suites, which abuts the Site to the west. However, no response was received.
Data Review
Data reviewed for this FYR include groundwater and sediment pore water data from the post-suspension PMP,
OU1 monitoring data for direct discharge to the city sewer, OU1 surface water and sediment monitoring data.
OU 1 landfill gas monitoring data and OlJ 1/OU2 wetlands monitoring data. Per- and polyfluoroalkyl substances
(PFAS) analytical data from a March 2023 groundwater sampling event were also reviewed. General findings of
this review are:
• Total VOC concentrations have rebounded since operation of the GWTP was suspended in July 2020.
The most significant rebound and increasing concentration trends are seen in the intermediate and deep
bedrock groundwater north of Hathaway Road between the former disposal area and the golf course. As a
result, the GWTP was turned back on in May 2023 to reestablish hydraulic containment.
• Total VOC concentrations in POC wells exceed the total VOC cleanup standard of 1,000 (.ig/L to 10,000
(ig/L.5
• Direct discharge of overburden groundw ater from the collection trench to the city sewer continues to meet
the discharge criteria at sample location MH-4.
• During biennial surface water and sediment sampling in 2019, VOCs and PCBs were not detected in
surface water samples. Carbon normalized PCB concentrations in sediment were below the OlJ 1 PCB
sediment cleanup goal of 20 (.ig PCB/g carbon.
• Methane is consistently detected in landfill gas monitoring wells along the eastern side of the landfill cap
(GM-17 and GM-18 and sporadically at GM-19 and GM-20) greater than 25% of the LEL. However,
multiple lines of evidence suggest that the methane detections along the eastern site boundary are not site
related.
• Wetlands monitoring observations at OU 1 and OU2 support the trend that the Middle Marsh wetland has
recovered from the restoration work for OU 1 and OU2, although invasive species control should
continue.
5 POC wells were established in the Post-Closure Environmental Monitoring Plan. October 1996.
21
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• Select groundwater samples were analyzed for PFAS for the first time in March 2023. Perfluorooctanoic
acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were detected above EPA tap water regional
screening levels (RSLs) in some samples. Total PFAS concentrations in most wells also exceeded the
Massachusetts Maximum Contaminant Level (MMCL) for total PFAS.
More information on the data review is below.
PMP Monitoring
With EPA approval, operation of the GWTP was temporarily suspended in July 2020 and the seven-year post
suspension PMP began. Event 1 of the PMP, which is considered the baseline sampling event, took place in
October 2020. The most recent event for which data were available for review (Event 6) took place in August
2022. The primary source of information for this review is the Sullivan's Ledge Superfund Site PMP Event 6
Report, dated December 2022. Preliminary data from Event 7. completed in January 2023, were also reviewed
and are discussed in context with the Event 6 data, as appropriate.
Groundwater Flow Direction
Figures G-l and G-2 in Appendix G present overburden well and shallow bedrock well groundwater contours
from Event 6 in August 2022. Overburden groundwater and shallow bedrock groundwater both flow northeast
and north from OU1 toward the downgradient wetland area where it is discharged. Figures G-3 and G-4 present
groundwater levels for the intermediate bedrock groundwater and deep bedrock groundwater, respectively. PMP
monitoring is not required at enough monitoring wells to develop representative contours in these bedrock zones.
However, based on the groundwater elevations, a general trend toward the dow ngradient wetland to the north is
observed in both the intermediate and deep bedrock groundwater, consistent with the overburden and shallow
bedrock groundwater flow directions.
Groundwater and Sediment Pore Water
Groundwater sampling locations for the post-suspension PMP included conventional monitoring wells,
piezometers and Westbay® well ports within the overburden zone and shallow, intermediate and deep bedrock
zones. Sediment pore water samples were also obtained from four locations (PW-1. PW-2, PW-3 and PW-4). The
monitoring locations are show n on Figures D-l through D-5 in Appendix D. Samples were analyzed for VOCs
and PCBs. Tables H-l and H-2 in Appendix H present summaries of the VOC groundwater data and PCB
groundwater data from Event 6. respectively. The tables include the number of locations with detections,
maximum detected concentrations and the location of the maximum detection concentration. VOC and PCB data
are discussed separately below .
VOCs
As shown in Table H-l. cis-1.2-DCE. benzene, ethylbenzene. toluene, vinyl chloride and TCE were the six
constituents present at the highest concentrations during PMP Event 6. The highest concentrations of these VOCs
were detected in non-operational recovery well OBG-1 and shallow bedrock wells MW-24 and MW-4. Consistent
with PMP Events 1 through 5A, cis-1.2-DCE was the highest detected VOC at 101,000 (ig/L (in OBG-1 during
PMP Event 6). The highest total VOC concentration was detected in OBG-1 at an estimated (J) concentration of
138,914 (ig/L. Consistent with previous PMP sampling events. VOCs were non-detect in pore water sample PW-
1. VOCs were also not detected in PW-2. Total VOCs were detected during PMP Event 6 at PW-3 (16.57 J (ig/L),
and PW-4/DUP PW-4 (148.36 J/150.45 J (ig/L).
Figures G-5 through G-l 5 in Appendix G provide an aerial depiction of the changes in total VOC concentrations
at all groundwater monitoring samples prior to startup of the GWTP in 1999, through the baseline sampling event
in October 2020 (PMP Event 1) and in August 2022 (PMP Event 6). Graphs 1-1 through 1-4 in Appendix I present
total VOC concentration trends in overburden groundwater monitoring locations, and shallow , intermediate and
deep bedrock groundwater monitoring locations over PMP Events 1 through 6.
The PMP program data to date show that VOC concentrations in many wells in all of the monitored zones are
increasing (Graphs 1-1 through 1-4) since shutdown of the GWTP in 2020. Some of the greatest increases, by one
to two orders of magnitude, are in deep bedrock groundw ater (Graph 1-4). The data also show VOCs are
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migrating downgradient of the former disposal area in overburden groundwater as well as shallow, intermediate
and deep bedrock groundwater (Figures G-5 through G-15). Groundwater contamination in shallow bedrock also
extends east of the OU1 landfill onto an adjacent parcel (MW-4). The eastern extent of contamination in this area
is not delineated beyond MW-4 (Figure G-2).
As of August 2022, VOCs have not been detected in the following downgradient points of evaluation: MW-5A
(overburden) and MW-5 (shallow bedrock) located northeast of the Site. MW-8A (overburden). MW-8, MW-10,
and MW-10B (shallow bedrock) located in the wetland area, or in pore water PW-1 located in the downstream
portion of the tributary. Only a low concentration (2.6 (.ig/L total VOCs) was detected once in overburden MW-
10AR (during PMP Event 5A). VOCs were not detected in MW-10AR during PMP Event 6. Therefore, the extent
of downgradient migration has not reached the furthest downgradient wells in the wetland area. Two of the
locations noted above. MW-5 and PW-1. were also sampled in Event 7 in January 2023. VOCs were not detected
in samples from either location.
The cleanup standard for the active collection system (recovery wells) is the significant reduction in the mass of
bedrock contamination in the groundwater bedrock monitoring wells that are designated as POCs. The monitoring
wells designated as POCs are bedrock wells MW-2. MW-4. MW-5, MW-6, MW-13, MW-17. MW-24. GCA-1
and all ports of Westbay® wells ECJ-1. ECJ-2 and ECJ-3. The analytical data from the most recent PMP Event
through August 2022 during which the POCs were sampled show the cleanup standard of 1,000 (ig/L to 10,000
(ig/L of total VOCs was exceeded at POCs GCA-1, ECJ-1 (72), and all ports of ECJ-2.' The total VOC cleanup
standard was not exceeded at POCs MW-2, MW-4, MW-5, MW-6, MW- 13, MW-17 and MW-24. ECJ-3 was not
sampled during the PMP program. At those POCs sampled in PMP Event 7 (January/February 2023), the cleanup
standard was exceeded at GCA-1. MW-6, ECJ-1 (72), ECJ-1 (267) and all ports of ECJ-2.
Due to increasing VOC concentrations, exceedances of the performance standard in POC wells and dow ngradient
migration of contaminants, the PMC, in coordination with the City of New Bedford, restarted the GWTP in May
2023. Data collection and evaluation are ongoing to determine if the system will regain hydraulic control.
PCBs
PCBs have been detected in samples from six of the 27 points of evaluation (ECJ-2 [47], ECJ-2 [117], ECJ-2
11521 and ECJ-2 [187], ECJ-5-14 and MW-6 A) and in samples from nine of the 19 non-points of evaluation
(OBG-1. BEI-1. EC J-1 1721. ECJ-1 [267], GCA-1. MW-2. MW-12AR, MW-24 and PZ-12) during the PMP
program to date.7 The highest concentration of total PCBs in each groundwater zone during the PMP program to
date were mostly detected in non-points of evaluation as follow s: overburden MW-12 AR at 0.96 (ig/L during
PMP Event 4; shallow bedrock MW-24 at 159 (ig/L during PMP Event 6; deep bedrock ECJ-1 (267) at 1.141
(ig/L during PMP Event 3; and in open-borehole former recovery well OBG-1 at 29.1 (ig/L during PMP Event 5.
The highest concentration of total PCBs in the intermediate bedrock was in point of evaluation ECJ-2 (152) at
12.5 (ig/L during PMP Event 2.
Graphs 1-5 through 1-8 in Appendix I present total PCBs concentration trends in overburden groundwater
monitoring locations, and shallow , intermediate and deep bedrock groundwater monitoring locations over PMP
Events 1 through 6. The groundwater data from the PMP sampling events to date show decreasing trends in total
PCB concentrations (when detected) or low fluctuating concentrations in most sampling locations. At the location
(MW-24) where the data trend show s an increase in the concentrations of PCBs in the unfiltered and filtered
samples obtained during the two PMP events sampled, the concentrations were either non detect or significantly
less in the filtered samples. The PMP program data to date shows that PCBs have only been detected at low
concentrations near the detection limit at points of evaluation ECJ-2 (47), ECJ-2 (117), ECJ-2 (152) and ECJ-2
(187), ECJ-5-14 and MW-6 A located upgradient of the tributary.
PCB data obtained from wells close to a surface water/sediment pore water discharge point (overburden MW-6A,
shallow bedrock MW-6, ECJ-2. ECJ-5. PZ-16 and PZ-17) were also compared to a site-specific GW-RBC for
6 For Westbay® wells, the well location is followed by the sample port depth, e.g., ECJ-1 (72).
7 Established points of evaluation from EPA letter dated December 4, 2018.
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protection of aquatic organisms from an August 2018 EPA memorandum, which is included in Appendix N. The
GW-RBC for total PCBs is 1.5 (ig/L. Pore water sample data were also compared to a toxicity benchmark of
0.014 (ig/L total PCBs from the 2018 EPA memorandum. Groundwater sample results from bedrock intervals
EC J-2 (47), EC J-2 (117), EC J-2 (152), and EC J-2 (187) exceeded the GW-RBC for total PCBs during PMP
Events 1, 2, 3 and/or 5. However, the GW-RBC for total PCBs was only exceeded at EC J-2 (152) during PMP
Event 6. Pore water sample results did not exceed the toxicity benchmark for PCBs during the October 2020
sampling event (Event 1), which was the only sampling event with detection limits lower than the toxicity
benchmark. PCBs were not detected in the pore water samples in subsequent events; however, detection limits for
the PCB samples (ranging from 0.24 (ig/L to 0.28 (ig/L) were greater than the toxicity benchmark of 0.014 (ig/L
total PCBs. The data show that although there is a potential for exposure by wetland/aquatic organisms as
evidenced by the underlying bedrock groundwater data, the overburden groundwater data does not exceed GW-
RBCs. The pore water data from the tributary show that there were no toxicity benchmark exceedances to PCBs
by wetland/aquatic organisms in October 2020, but it is unknow n if more recent data exceed the benchmark
because detection limits were greater than the toxicity benchmark.
OU1 Monitoring of Direct Discharge to Sewer
Groundwater from the shallow collection trench has been directly discharged to the sewer at times when water
levels in the shallow collection trench are high enough to reach the invert of the gravity pipe. The direct discharge
to the sewer has to meet discharge criteria established in the City's industrial pretreatment discharge permit. Since
shutdown of the GWTP. the discharge is monitored at manhole MH-4 approximately quarterly and results have
been included in the City's quarterly reports. Of the reports available for review from October 2020 to July 2021
and April 2022, some VOCs and metals have been detected in the samples at levels below the pretreatment
criteria. PCBs were not detected. Discharge criteria are being met.
OU1 Long-Term Surface Water and Sediment Monitoring
The most recent long-term biennial surface water and sediment monitoring was performed in September 2019.
Sampling did not take place in 2021 in lieu of the pore water sampling taking place as part of the post-suspension
PMP. Figure G-16 in Appendix G shows the surface water and sampling locations. Tables H-3 and H-4 in
Appendix H present the data summary tables from the September 2019 Biennial Surface Water and Sediment
Monitoring Report.
Surface water samples were collected from three of the five specified locations (SW-1. SW-2 and SW-4). Surface
water samples were unable to be collected at SW-3 and SW-5 because there was no standing water present at the
time of sampling. Samples were analyzed for VOCs. PAHs. PCBs and total analyte list (TAL) metals, including
mercury. For PCB and metals analysis, two sets of samples were collected, one filtered and the other unfiltered.
Sediment samples were collected from five locations (SD-1 through SD-5) and analyzed for PCBs. PAHs. TAL
metals, total organic carbon (TOC) and percent solids. Because VOCs and PCBs are the primary constituents of
concern at the Site, they are addressed further in this review.
VOCs and PCBs were not detected in the surface water samples. PCBs were detected in the sediment samples at
concentrations up to 0.124 mg/kg (SD-1 duplicate). The maximum detected concentration in 2019 was lower than
the maximum detected concentration in 2017 (0.952 mg/kg in SD-3). The detected PCB concentrations in 2019
were converted to carbon normalized PCB concentrations, using TOC results, for comparison to the OU1 PCB
sediment cleanup goal of 20 jig PCB/g carbon. All carbon normalized PCB concentrations were below the OlJ 1
PCB sediment cleanup goal.
OU 1 Landfill Gas Monitoring
Landfill gas monitoring is conducted quarterly in accordance with the 2015 Surface Water. Sediment and Landfill
Gas Monitoring Field Sampling Plan. During each event, the landfill gas monitoring wells along the perimeter of
the landfill cap. the discharge stack of the gas extraction system and ambient air near the gas extraction unit are
screened for VOCs. methane, carbon dioxide, oxygen and hydrogen sulfide. Figure G-17 in Appendix G show s
the monitoring locations. Ambient air. along the fence line and within catch basins at the gas station northeast of
the former disposal area, is also screened for landfill gases.
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Methane is consistently detected in landfill gas monitoring wells along the eastern side of the landfill cap (GM-17
and GM-18 and sporadically at GM-19 and GM-20) greater than 25% of the LEL. For example, in the recent
monitoring event in December 2022, methane was detected in the p re-purge and post-purge samples from GM-18
at 4.6%, which is 92% of the methane LEL. Table H-7 in Appendix H includes a summary of the Landfill Gas
Monitoring Report from December 2022. The methane levels in the pre-purge and post-purge samples from GM-
18 exceeded the Massachusetts Solid Waste Management 25% LEL criterion. VOCs were detected in only the
pre-purge samples in GM-17 (2.2 parts per million, ppm) and GM-18 (0.2 ppm). Hydrogen sulfide was detected
in the pre- and post-purge samples from GM-18 at 4 ppm. Consistent with previous sampling events, methane,
hydrogen sulfide or VOCs were not detected in ambient air samples.
GV-2 was connected to the landfill gas extraction system as requested by the agencies in September 2019.
Landfill gas data on the eastern boundary of the Site continue to show methane levels similar to levels before the
connection of GV-2 to the system. Because GM-18 and GM-17 and other wells along the eastern border still show
methane readings similar to those observed before the connection, there is a strong line of evidence that there
could be an off-site source.
OU1/OU2 Wetlands Monitoring
Post-construction environmental monitoring activities were required annually for the first three years, in year five,
and then once every five years. The City of New Bedford led the most recent environmental monitoring event in
2021, with results documented in the 2022 Environmental Monitoring Sampling and Results Report. The 2021
monitoring event included the follow ing activities:
• Collection of four co-located surface water and sediment samples (three locations in the Unnamed Stream
and one location in the unnamed pond north of Middle Marsh) with analysis for PCBs and TOC.
• Collection of six wetland soil/non-aquatic sediment samples (four from Middle Marsh and two from the
Adjacent Wetlands) with analysis for PCBs and TOC.
• Wetlands monitoring observations at OU 1 and OU2. Activities include monitoring of hummocks,
wetlands hydrology, soil development and biological attributes including survival rates of planted trees
and shrubs, tree growth, vegetative diversity, plant community and presence of the Mystic Valley
Am phi pod.
Figure G-18 in Appendix G shows the sampling locations. Table H-5 in Appendix H presents the sampling
results. The 2017 QAPP required that samples be collected during low stream flow; however, due to an
unseasonably wet season, this condition was not met for the October 2021 sampling event. Based on the results
presented below , sampling at normal water levels does not appear to have significantly affected the data.
Consistent with results from 2013 and 2017, PCBs were not detected in any of the surface water samples
(reporting limit of 0.1 (.ig/L).
Total PCBs were detected in three of the four sediment samples with results ranging from 0.0294 mg/kg to 0.229
mg/kg. The detected concentrations were converted to carbon normalized PCB concentrations, using TOC results,
for comparison to the OU2 PCB sediment cleanup goal of 20 (.ig PCB/g carbon for aquatic areas. All of the carbon
normalized PCB concentrations were below the sediment cleanup goal for aquatic areas. The 2021 results
represented a decrease in carbon normalized PCB concentrations from the previous sampling event in 2017 when
carbon normalized PCB concentrations were above the sediment cleanup goal.
PCBs were detected in one wetland soil/non-aquatic sediment sample (SoilPC3 from location OU2-MM2)
collected in Middle Marsh. The detected concentration of 0.0287 mg/kg was below the OU2 PCB sediment
cleanup level of 15 mg/kg for non-aquatic areas.
Goals of the wetland monitoring are to evaluate four biological indicators: 1) survival rate of trees and shrubs. 2)
tree growth. 3) vegetative diversity and 4) plant community. Wetlands monitoring observations at OlJ 1 and OU2
support the trend that the Middle Marsh wetland has recovered from the restoration work for OU 1 and OU2. The
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plant community continues to diversify in species composition and vertical structure. The overall canopy
coverage continues to increase. The targeted invasive species management in areas such as in OU1 MM 1 and
OU1 MW1 appears to have had a sustained benefit. Several plots that were previously dominated by poison ivy
(Toxicodendron radicans) such as in OU2 Adjacent Wetlands #1 have now matured and diversified to include a
greater variety of herbaceous species. Efforts should be made to ensure the invasive species in areas maintained
by the golf course and in areas that have observed population of invasives do not cross allow able thresholds.
PFAS Monitoring Data
EPA contractors collected groundwater samples from four locations that monitor overburden groundwater (MW-
6A. MW-12AR, PZ-11, PZ-15A) and four locations that monitoring shallow bedrock groundwater (GCA-1. MW-
6. MW-24 and PZ-17S) in March 2023 (Figures D-l and D-2 in Appendix D). The samples were analyzed for
PF AS. Table H-6 in Appendix H includes a summary of the detected PF AS. Results are compared to EPA's tap
water RSLs based on a noncarcinogenic hazard quotient (HQ) of 0.1. and the MMCL for total PFAS (20
nanograms per liter. ng/L). Of the PFAS detected. PFOS concentrations exceeded the RSL of 4 ng/L at five
locations with a maximum detected concentration of 10 ng/L at MW-6. PFOA concentrations exceeded the RSL
of 6 ng/L at all eight locations sampled. The maximum detected concentration of PFOA was estimated at 29 ng/L
at GC A-1. Total PFAS concentrations at six sample locations exceeded the MMCL of 20 ng/L for total PFAS.
Site Inspection
The site inspection was conducted on 3/22/2023. In attendance were EPA CIC Aaron Shaheen. Jennifer Lambert
and Erik Hall from EPA contractor Nobis Group and Johnny Z i m m e rm an - Wa rd and Jill Billus from EPA FYR
support contractor Skeo. City of New Bedford participants included Jim Costa. Chance Perks. Michele Paul.
Laura Breig and David Nieves. EPA RPM kimberly White, EPA ecological risk assessor TaChalla Gibeau and
EPA human health risk assessor Ayana Cunningham joined the group via video conference for the beginning of
the meeting. The purpose of the inspection was to assess the protectiveness of the remedy. Appendix J includes
the completed site inspection checklist. Appendix K includes photographs from the site inspection.
Site inspection participants met in the parking area for the OU 1 GWTP. and then viewed the treatment building
interior. The groundwater treatment system was not operating at the time of the inspection. The City of New-
Bedford representative noted that preparations were underway to bring the system back online by May 1. 2023.
Site inspection participants then walked across Hathaw ay Road to the golf course (OU2). They observed some
minor iron-rich siltation in the culvert under Hathaway Road. The restored wetland areas in OU2 appeared in
good condition. Some invasive species were observed. The City of New Bedford representative indicated that a
Notice of Intent had been filed recently to allow the City to remove the phragmites throughout the golf course
wetlands. The phragmite spraying is planned for late summer, which will be followed by a cut and removal of the
phragmites. Monitoring well MW-8 on the golf course property was not secured properly, and some minor
erosion was observed beneath the well pad.
Site inspection participants also observed the OlJ 1 landfill area, which is surrounded by a chain-link fence. An
area of the fence along Hathaway Road appeared to have a temporary repair. The City of New Bedford indicated
that it had been damaged by a car. A more permanent fence repair is planned. The landfill's cover is well
established with grass. No bare spots were observed. An animal burrow was observed on the north side of the
landfill cap; animal burrow s were also observed beneath one of the solar panel footings near the center of the
landfill. Minor vegetation was observed in the riprap drainages on the landfill but did not appear as if it would
impede flow . Site inspection participants also observed the extraction well housings, gas wells and monitoring
locations, monitoring wells and the location of the shallow collection trench and slurry wall. The City of New-
Bedford representatives indicated that the electrical wiring and other components for the extraction wells had
recently been replaced in anticipation of the GWTP startup. The extraction well housings were in poor condition.
The City of New Bedford representative noted that they may be replaced as funds allow .
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V. TECHNICAL ASSESSMENT
QUESTION A: Is the remedy functioning as intended bv the decision documents?
Question A Summary:
OU1
No. Based on review of site documents, monitoring data. RAOs and site inspection results, the OU 1 remedy is not
functioning as intended by the 1989 ROD. as modified by the 1995, 2000 and 2003 ESDs. Operation of the
GWTP was suspended in 2020 but restarted in May 2023. Between 2020 and 2023, the post-suspension
groundwater monitoring data revealed that total VOC concentrations in groundw ater are increasing and migrating
north towards the OU2 wetlands. Now that the GWTP has been restarted the control of groundwater contaminant
migration is currently being evaluated.
OU2
Yes. Based on review of site documents, monitoring data. R AOs and site inspection results, the OU2 remedy is
functioning as intended by the 1991 ROD. Further discussion for both OlJs is presented below .
Remedial Action Performance
OU1
The OU 1 remedy included excavation of contaminated soils/sediments from the Unnamed Stream, water hazards
on the golf course property and other areas of OU 1 with placement in the former disposal area, construction of an
impermeable cap. collection and treatment of contaminated groundw ater, construction of a landfill gas extraction
system, wetlands restoration, long-term monitoring, and institutional controls.
The remedial action met the soil and sediment cleanup standards set in the 1989 ROD and ESDs. thus removing
the source of contamination to sediment and surface water and reducing risk to human health and aquatic
organisms. O&M of the landfill cap and gas extraction system has been effective to eliminate direct exposure to
contamination and waste.
Groundwater and pore water monitoring data have show n that total VOC concentrations have rebounded since
operation of the GWTP was suspended in 2020. The most significant rebound and increasing concentration trends
are seen in the intermediate and deep bedrock groundw ater north of Hathaw ay Road betw een the former disposal
area and the golf course. In addition, monitoring data have show n that total VOC concentrations in POC wells
exceed the total VOC cleanup standard of 1,000 (.ig/L to 10,000 (ig/L. Shallow bedrock monitoring well MW-4,
located east of the OU 1 landfill and on an adjacent property where no groundwater use restrictions are in place,
also had a total VOC concentration greater than 1,000 (ig/L in 2022. As a result, the GWTP was turned back on in
May 2023 to reestablish hydraulic containment. Monitoring will continue to evaluate contaminant concentrations
over time and potential impacts to dow ngradient ecological receptors. Further evaluation may also be needed to
delineate the eastern extent of contamination beyond MW-4.
As requested by EPA. PMC is evaluating groundwater data and pore water data against GW-RBCs for ecological
protection. The overburden groundwater data do not exceed GW-RBCs. The pore water data from the tributary
collected in October 2020 show that there were no toxicity benchmark exceedances for PCBs at that time. PCBs
were not detected in the pore water samples in subsequent sampling events; however, detection limits for the PCB
samples were greater than the toxicity benchmark of 0.014 (ig/L total PCBs. EPA and MassDEP will continue to
evaluate the need for further remedial action at the Site, or an update to the cleanup standards.
Methane continues to be detected in landfill gas monitoring wells along the eastern side of the landfill cap greater
than 25% of the LEL. However, multiple lines of evidence suggest that the methane detections along the eastern
site boundary are not site related. Landfill gas monitoring is ongoing.
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0U2
The 0U2 remedy included excavation of contaminated soils/sediment from parts of Middle Marsh and Adjacent
Wetlands with placement under the OU1 cap. wetlands restoration, institutional controls to prevent future land use
and long-term monitoring. The OU2 remedy was complete by 2001. The most recent wetlands monitoring event
took place in 2021. PCBs were not detected in surface water samples during the 2021 sampling event, and PCBs
were below ROD sediment cleanup goals. Wetlands monitoring observations support the trend that the Middle
Marsh wetland has recovered from the restoration work. The plant community continues to diversify in species
composition and vertical structure. The overall canopy coverage continues to increase. The targeted invasive
species management conducted during the FYR period appears to have had a sustained benefit. Efforts should be
made to ensure the invasive species in areas maintained by the golf course and in areas that have observed
population of invasives do not cross allowable thresholds.
System Operations/O&M
OU1
The City of New Bedford is responsible for implementing O&M activities at OlJ 1. The activities address O&M of
the landfill cap. groundw ater collection and treatment system, and landfill gas extraction system. The City of New-
Bedford noted that many components of the GWTP are reaching the end of their functional timeframe; many parts
need to be repaired or replaced. The Sullivan's Ledge Site Group PMC implements the Site's groundwater,
landfill gas. sediment and surface water long-term monitoring program. The O&M Plan should be updated to
include any requirements associated with the solar panels installed in 2014.
OU2
Post-construction environmental monitoring and long-term wetlands monitoring activities are conducted in
accordance with the 1997 Wetland Restoration Plan and the 1999 Final Operation and Maintenance Plan for the
Second Operable Unit. The City of New Bedford led the most recent wetlands monitoring event in 2021.
Implementation of Institutional Controls and Other Measures
OU1 and OU2
Institutional controls have been implemented in the form of a GERE and no violations have been reported.
How ever, the City of New Bedford has not been submitting annual compliance reports, as required by the GERE.
Elevated VOC concentrations were detected in shallow bedrock well MW-4 in August 2022. This well is located
east of OU 1 and outside areas covered by the existing institutional control instrument (Figure 3). This is not a
current issue of protectiveness since the property uses public water. However, additional institutional controls
may be needed to prohibit groundwater use on the parcel to ensure long-term protectiveness of the remedy.
QUESTION 6: Are the exposure assumptions, toxicity data, cleanup levels and RAOs used at the time of
the remedy selection still valid?
Question 6 Summary:
No. There have been changes in toxicity values, exposure pathways and method of evaluating risk since the 1989
and 1991 RODs were issued as discussed below . In addition. PFAS. an emerging contaminant, has been detected
in groundwater at the Site at levels above EPA's RSLs. However, the changes noted below do not affect
protectiveness of the remedy because groundwater at the Site is not in use for drinking water and institutional
controls are in place and effectively prevent future exposures to contaminated groundwater at the Site.
Changes in Standards and To Be Considered Criteria (THCs)
New standards (federal or state statutes and/or regulations), as well as new TBC guidance, should be considered
during the FYR process as part of the protectiveness determination. Under the NCP. if a new federal or state
statute and/or regulation is promulgated or a new TBC guidance is issued after the ROD is signed, and. as part of
the FYR process it is determined that the standard needs to be attained or new guidance procedures followed to
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ensure that the remedy is protective of human health and the environment, then the FYR should recommend that a
future decision document be issued that adds the new standard as an applicable or relevant and appropriate
(ARAR) or guidance as a TBC to the remedy.
EPA guidance states:
"Subsequent to the initiation of the remedial action new standards based on new scientific information or
awareness may be developed and these standards may differ from the cleanup standards on which the remedy
was based. These new... | standards] should be considered as part of the review conducted at least every five
years under CERCLA § 121(c) for sites where hazardous substances remain on-site. The review requires EPA
to assure that human health and the environment are being protected by the remedial action. Therefore, the
remedy should be examined in light of any new standards that would be applicable or relevant and appropriate
to the circumstances at the site or pertinent new |standards|. in order to ensure that the remedy is still
protective. In certain situations, new standards or the information on which they are based may indicate that
the site presents a significant threat to health or environment. If such information comes to light at times other
than at the five-year reviews, the necessity of acting to modify the remedy should be considered at such
times." (See CERCLA Compliance with Other Laws Manual: Interim Final (Part 1) EPA/540/G-89/006
August 1988, pp. 1-56.)
The 1989 ROD identified Safe Drinking Water Act MCLs and the Massachusetts groundwater quality standards
as relevant and appropriate at the Site. However. EPA waived compliance with the ARARs relating to
groundwater because compliance with the ARARs is technically impracticable from an engineering perspective.
As such, cleanup levels for the active collection system are not ARAR-based. Instead, two performance criteria
were established: 1) a concentration range of 1 mg/L to 10 mg/L total VOCs. and 2) an asymptotic curve using
groundwater monitoring data indicating that significant concentration reductions are no longer being achieved.
The 1989 ROD stated that the cleanup levels for the passive collection system will be based on AWQS and the
designated use of the receiving waters.
The 2003 ESD added the Massachusetts Solid Waste Management Facility regulations (Sections 19.117. 19.118,
19.132 and 19.150 in the Code of Massachusetts Regulations) pertaining to landfill gas as an additional ARAR for
the Site. These regulations require the detection and monitoring of landfill gases, the use of corrective actions
when gases exceed 25% of the LELs to address public health and safety concerns, and the notification of
government parties within specified time frames when such concentrations are detected. The ARARs have not
changed in a manner that could affect protectiveness of the remedy.8
Per- and Poly fluoroalkyl Substances fPFAS) (Federal)
In May 2022, EPA issued updated noncancer reference dose (RfD) values for several PFAS compounds which
result in the following RSLs at HQ target of 0.1:
• PFOA: 6 ng/L (equivalent to parts per trillion |ppt|)
• PFOS: 4 ng/L
• Perfluorononanoic acid (PFNA): 6 ng/L
• Perfluorohexane sulfonate (PFHxS): 40 ng/L
• Hexafluoropropylene oxide dimer acid (HFPO-DA) (Gen-X): 6 ng/L
The RfD values for PFOA. PFOS. PFNA and PFHxS are based on Agency for Toxic Substances and Disease
Registry (ATSDR) Minimal Risk Levels (MRLs) for ingestion exposure.
The RfD value for HFPO-DA (Gen-X) is based on a chronic oral RfD from EPA Office of Water, which is 3E-06.
8 https://www.mass.gov/regulations/310-CMR-19000-solid-waste-facilitv-regulations (accessed 5/18/2023).
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In May 2021, EPA issued an updated noncancer RfD for perfluorobutane sulfonic acid (PFBS). PFBS has a
chronic oral RfD of 3E-04. The RSL for PFBS is 600 ng/L.
In December 2022, EPA released a new oral RfD of 1.0E-03 milligrams per kilogram per day (mg/kg-day) for
perfluorobutanoic acid (PFBA) based on a new Integrated Risk Information System (IRIS) value. Previously, no
RfD was available for PFBA. The RSL for PFBA is 1,800 ng/L.
In April 2023, EPA released a new oral RfD of 5.0E-04 mg/kg-day for perfluorohexanoic acid (PFHxA) based on
a new IRIS value. Previously no RfD was available for PFHxA. The RSL for PFHxA is 990 ng/L.
/'/¦AS {State}
On October 2, 2020, the state promulgated MMCLs for drinking water for the sum of six PFAS compounds into
the state's drinking water regulations (310 CMR 22.00). The MMCL is 20 ng/L (ppt) for the sum of six PFAS
compounds:
• PFOS
• PFOA
• PFHxS
• PFNA
• Perfluoroheptanoic acid (PFHpA)
• Perfluorodecanoic acid (PFDA)
At this time EPA has made no determination of whether these state standards will need to be added as an ARAR
for this Site. They should, however, be used as screening values for PFAS compounds, along with the RSLs. For
purposes of this FYR. EPA has evaluated the PFAS data collected against EPA's RSLs and the state's PFAS
MMCLs.
/'/•AS (Summary)
Several PFAS were detected in site groundwater during a March 2023 sampling event. PFOS and PFOA
concentrations were detected in several samples above the EPA RSLs. The maximum detected PFOS
concentration was 10 ng/L (MW-06) compared to the RSL of 4 ng/L. The maximum detected PFOA
concentration was a concentration of 29 J ng/L (GC-1), compared to the RSL of 6 ng/L. The sum of six PFAS
compounds also exceeded the state's PFAS MMCL in six samples (GC A-1. MW-6, MW-6A. MW12-AR, MW-
24 and PZ-5A), with the maximum detected sum of the six PFAS of 34.9 ng/L.
Although there are exceedances of the RSLs and the state MMCL, the remedy remains protective because no one
is drinking the groundwater and institutional controls are in place and effective at preventing future exposures to
groundwater. However, as the GWTP has been restarted, influent and effluent will be monitored for PFAS to
determine if additional measures are needed to treat PF AS or to prevent it from being discharged to the publicly
owned treatment works (POTW). In addition, additional investigation of PFAS in surface water and sediment is
being considered, with results compared to the ecological screening values (ESVs) for PFAS.
1,4-Dioxane (Federal)
Using 2013 updated IRIS toxicity information and the standard Superfund risk assessment approach. EPA's
carcinogenic risk range of 10"6 to 10"4 for 1,4-dioxane equates to a concentration range of 0.46 (.ig/L to 46 (.ig/L
(parts per billion).
1.4-Dioxane (Summary)
1,4-Dioxane has not been sampled for at the Site. However, even if detected, the remedy remains protective for
human health because no one is drinking the groundwater and institutional controls are in place and effective at
preventing future exposures to groundwater. The ecological exposure pathway for aquatic receptors potentially
exposed to 1,4-dioxane in surface water downgradient of OU1 has not been evaluated. Therefore, surface water
samples may need to be collected for 1,4-dioxane and compared to the ESV of 22,000 (ig/L.
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Floodplain
Federal regulations at 40 CFR Part 6. Appendix A identified in the ROD were withdrawn. Furthermore, these
regulations, and therefore the current CERCLA remedy, only addressed potential floodplain impacts up to the
100-year flood elevation. Current federal floodplain regulations at 40 CFR Part 9 require a greater assessment of
potential floodplain impacts, including preventing the release of contamination from waste management units and
other remedial infrastructure up to the 500-year floodplain elevation. EPA has assessed potential floodplain
impacts from a 500-year flood event on the Site. The GWTP and capped landfill are outside the 500-year
floodplain. Because EPA has not identified any protectiveness issues at this time, we do not include a
recommendation to add this requirement as an ARAR in a future determination.
Changes in Toxicity and Other Contaminant Characteristics
The 1989 and 1991 RODs selected soil cleanup levels for PCBs and total carcinogenic PAHs based on human
health risk. The RODs also selected sediment cleanup levels protective of ecological receptors. Based on
evaluation of the cleanup levels compared to current RSLs. the cleanup levels based on human health risk remain
protective (Appendix L). The sediment cleanup levels based on ecological risk also remain protective.
The sediment cleanup level was established as 20 (.ig of PCBs per gram of carbon. This risk-based target level was
developed based on potential risk to aquatic organisms and wildlife receptors. The cleanup level was estimated in
the risk assessment using sediment partitioning and the ambient water quality criteria based on the protection of
wildlife consuming aquatic organisms. PCB tissue concentrations estimated from direct exposure to PCB-
contaminated sediments were also used in developing the risk-based target level of 20 (.ig per gram of carbon. As
noted in the 2018 FYR Report, based on larger risk-based data sets from other sites in New England with aquatic
habitats, this level of PCBs in sediments is expected to be protective of aquatic and semi-aquatic receptors.
2022 cis-l,2-DCE Noncancer Toxicity Value
In October 2022, EPA released a noncancer reference concentration (RfC) of 4.00E-02 milligrams per cubic
meter for cis-1.2-DCE. based on a provisional peer reviewed toxicity value (PPRTV) screening value. Previously,
no RfC was available for cis-1.2-DCE.
Cis-1.2-DCE is consistently detected in Site groundwater. The maximum detected concentration during PMP
Event 6 of the PMP was 101,000 (.ig/L (OBG-1). The change in the toxicity value for cis-l,2-DCE does not affect
the protectiveness of the remedy because no one is drinking the groundwater and institutional controls are in place
to prevent future use of the groundwater.
2022 PFBA Noncancer Toxicity Value
In December 2022, EPA released a new oral RfD of 1.0E-03 mg/kg-day for PFBA based on a new IRIS value.
Previously, no RfD was available for PFBA.
PFBA was detected at a maximum concentration of 18 ng/L in PZ-1 1 in March 2023 and below the PFBA RSL of
1,800 ng/L. The remedy remains protective because no one is drinking the groundwater and institutional controls
are in place and effective at preventing future exposures to groundwater.
2022 PFOA Noncancer Toxicity Value
In May 2022, EPA released an updated oral RfD of 3E-06 mg/kg-day for PFOA. based on the ATSDR MRL. The
new value indicates that PFOA is more toxic from noncancer health effects and would result in an increased
noncancer risk.
PFOA was detected at a maximum concentration of 29 ng/L in GC A-1 in March 2023, which exceeds the EPA
RSL and the state MCL. However, the remedy remains protective because no one is drinking the groundwater and
institutional controls are in place and effective at preventing future exposures to groundwater.
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2022 PFOS Noncancer Toxicity Value
In May 2022, EPA released an updated oral RfD of 2E-06 mg/kg-day for PFOS. based on the ATSDR MRL. The
new value indicates that PFOS is more toxic from noncancer health effects and would result in an increased
noncancer risk.
PFOS was detected at a maximum concentration of 10 ng/L in MW-06 in March 2023, which exceeds the EPA
RSL. The remedy remains protective because no one is drinking the groundw ater and institutional controls are in
place and effective at preventing future exposures to groundwater.
2022 PFNA Noncancer Toxicity Value
In May 2022, EPA released an oral RfD of 3E-06 mg/kg-day for PFNA, based on the ATSDR MRL. Previously,
no RfD was available for PFNA.
PFNA was not detected in site groundwater in March 2023, with a maximum detection limit of 2 ng/L. Therefore,
there is no impact to protectiveness.
2022 PFHxS Noncancer Toxicity Value
In May 2022, EPA released an oral RfD of 2.0E-05 mg/kg-day for PFHxS. based on the ATSDR MRL.
Previously, no RfD was available for PFHxS.
PFHxS was detected at a maximum concentration of 2.2 ng/L in MW-12AR and PZ17S in March 2023, which is
below the EPA RSL. Additionally, the remedy remains protective because no one is drinking the groundwater and
institutional controls are in place and effective at preventing future exposures to groundwater.
2021 PFBS Noncancer Toxicity Value
In May 2021, EPA released an oral RfD of 3E-04 mg/kg-day. based on an EPA PPRTV (USEPA. 2021a). The
new value indicates that PFBS is more toxic from noncancer health effects and would result in an increased
noncancer risk.
PFBS was detected at a maximum concentration of 2.6 ng/L in MW-24 in March 2023, which is below the EPA
RSL. Additionally, the remedy remains protective because no one is drinking the groundwater and institutional
controls are in place and effective at preventing future exposures to groundwater.
2020 Trans-1,2-Dichloroethylene (Trans-1,2-DCE) Noncancer Toxicity Value
In November 2020, EPA finalized a new RfC for trans-1.2-DCE based on a new PPRTV. There previously was
no RfC for trans-1,2-DCE.
Trans-1,2-DCE is consistently detected in site groundwater. The maximum detected concentration during Event 6
of the PMP was 91.4 J (ig/L (BEI-1). The change in the toxicity value for trans-1.2-DCE does not affect the
remedy because no one is drinking the groundwater and institutional controls are in place to prevent future use of
the groundwater.
Lead in Soil Cleanups
EPA continues to examine the science around lead exposure. Updated scientific information indicates that adverse
health effects are associated with blood lead levels (BLLs) at less than 10 micrograms per deciliter ((.ig/dL).
Several studies have observed "clear evidence of cognitive function decrements in young children with mean or
group BLLs between 2 and 8 (.ig/dL."
Based on this updated scientific information. EPA is including an evaluation of potential lead risks with a goal to
limit exposure to residential and commercial soil lead levels such that a typical (or hypothetical) child or group of
similarly exposed children would have an estimated risk of no more than 5% of the population exceeding a 5
(ig/dL BLL. This is based on evidence indicating cognitive impacts at BLLs below 10 (ig/dL. A target BLL of 5
(ig/dL reflects current scientific literature on lead toxicology and epidemiology that provides evidence that the
adverse health effects of lead exposure do not have a threshold.
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EPA's 2017 OLEM memorandum "Transmittal of Update to the Adult Lead Methodology's Default Baseline
Blood Lead Concentration and Geometric Standard Deviation Parameters" (OLEM Directive 9285.6-56) provides
updates on the default baseline blood lead concentration and default geometric standard deviation input
parameters for the Adult Lead Methodology (ALM). These updates are based on the analysis of the National
Health and Nutrition Examination Survey 2009-2014 data, with recommended updated values for baseline blood
lead concentration being 0.6 (.ig/dL and geometric standard deviation being 1.8.
Using updated default Integrated Exposure Uptake Biokinetic Model and ALM parameters at a target BLL of 5
(ig/dL, site-specific lead soil screening levels (SLs) of 200 ppm and 1,000 ppm are developed for residential and
commercial/industrial exposures, respectively.
Given the ongoing review of information, the above SLs are considered in this FYR for informational purposes.
A review of historical soil and sediment samples collected during the Rl. conducted as part of the 2018 FYR
Report, showed some detected lead concentrations above 200 mg/kg. but these locations were either covered
(capped) or excavated as part of the OU1 and OU2 remedies. In addition, the maximum detected lead
concentration in OlJ 1 sediment (sampled/analyzed in 2019) is 120 J mg/kg. which is below the lead SL for
residential exposures. In addition, there are institutional controls in place at the landfill property and golf course
property that prohibit residential use of the properties. Therefore, the updates to the lead SLs do not affect
protectiveness of the remedy.
Changes in Risk Assessment Methods
There have been multiple changes to EPA's risk assessment methodologies since the Site's 1991 risk assessment,
as summarized in previous FY R reports. However, there are no additional changes in risk assessment methods
from the previous FY R, other than routine updates to EPA's RSLs, which have been incorporated in the chemical-
specific screening of the monitoring data discussed throughout this FY R Report.
Changes in Exposure Pathways
Land use at the Site has not changed since the previous FYR. OU 1 is a capped landfill surrounded by a fence.
Solar panels were installed on the cap in 2014. There are no anticipated changes in land use at OU 1. OU2
includes part of the Whaling City Golf Club. This portion of the Site will continue to be used as a golf course or
for other recreational purposes in the foreseeable future. Institutional controls are in place to assure that land use
changes resulting in more intense human exposures than under current conditions do not occur.
As noted previously. PFAS. an emerging contaminant of concern, has been identified in groundwater above EPA
RSLs. However, there are no current exposures to contaminated groundwater. Public water is available for the
Site and surrounding area. Institutional controls are in place to prevent exposures to contaminated groundwater on
City of New Bedford property (OU 1 and the Whaling City Golf Club); however, additional institutional controls
may be needed to prevent groundwater use on the property east of OU 1 where total VOC concentrations are
greater than 1,000 (.ig/L and concentrations of individual constituents (such as TCE) exceed drinking water
standards. Additional sampling for PFAS in pore water and/or surface/sediment in the wetland areas may also be
considered.
Vapor Intrusion
While there has been some historical evaluation of landfill gas migration to neighboring properties, vapor
intrusion of volatiles from groundwater had not been evaluated prior to the 2018 FYR. Buildings are located to
the east of the landfill in an area where groundwater is about 15 feet below the ground surface. The 2018 FYR
Report reviewed groundwater sampling results for overburden wells in this area and performed a comparison to
EPA's Vapor Intrusion Screening Levels (VISLs) based on a commercial use exposure scenario. Based on the
available groundwater data and current commercial use of the area, the 2018 FYR Report concluded that the
remedy appears to be protective with regards to vapor intrusion risk.
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This FYR re-evaluates vapor intrusion risk to the gas station building and storage buildings east of the Site using
EPA's VISL calculator and recent groundwater data from overburden wells MW-12AR (2022 data) and MW-4A
(2020 data), both of which appear to be within 150 feet of a building (Figure G-l, Appendix G). Based on the
screening-level evaluation, vapor intrusion is not a concern at the Site at this time because detected concentrations
correspond to risks that fall within EPA's risk management range of 1 x 1()"" to 1 x 10"4 and the corresponding
noncancer HQ is below EPA's point of departure of 1 (Appendix M). However, if Site conditions change (i.e.,
change in land use or increase in contaminant concentrations), the potential for vapor intrusion should be re-
evaluated.
2018 EPA VISL Calculator
In February 2018, EPA launched an online VISL calculator which can be used to obtain risk-based screening
level concentrations for groundwater, sub-slab soil gas and indoor air. The VISL calculator uses the same
database as the RSLs for toxicity values and physiocheinical parameters and is automatically updated during the
semiannual RSL updates. The User's Guide provides further details on how to use the VISL calculator:
https://www.epa.gov/vaporintrusion/vapor-intrusion-screening-level-calculator.
As noted above, the VISL calculator was used for a screening-level vapor intrusion assessment; current issues of
concern for vapor intrusion were not identified.
2018 Groundwater Risk-Based Concentrations (GW-RBCs)
In August 2018, GW-RBCs were developed for the Site to address the recommendation in MassDEP's 2016
Groundwater Use and Value Determination to consider the potential impacts to aquatic organisms in surface
water that receives groundw ater from OU1. Appendix N provides a copy of the GW-RBCs. The GW-RBCs are
currently being used by the project team and groundwater data does not exceed GW-RBCs. However, to evaluate
the in-stream ecological impacts, the current detection limits for the toxicity analysis need to be adjusted.
Additional evaluations also need to be conducted in order to determine if Site cleanup levels need to be updated to
align with the site-specific GW-RBCs. As an interim action the GW-RBCs should be incorporated into the site
groundwater monitoring plan and used to screen potential impacts to ecological receptors.
2021 Development of the ESVs for PFAS
ESVs have been developed to support screening-level ecological risk assessments sites where PFAS have been
detected in soils and surface waters. The ESVs. developed for eight PFAS. represent PFAS concentrations in soil
and surface water at or below which chronically exposed biota are not expected to be adversely affected and
ecological risks or other impacts are unlikely.
The ESVs support the screening-level steps (steps 1 and 2 of eight steps) of EPA" s Ecological Risk Assessment
Guidance for Superfund and may be applied at sites undergoing investigation for the historic release or disposal of
PFAS. to identify whether PFAS levels pose potential unacceptable ecological risks. Sites that have
concentrations of PFAS that exceed ESVs may require further investigation in a baseline ecological risk
assessment, which in turn may support risk-management decisions and actions to reduce risks. These ESVs are
solely for use in conducting screening-level ecological risk assessments and are not recommended or intended for
use as default cleanup values.
The ESVs were developed for the follow ing media and receptors:
• Soils for invertebrates.
• Soils for plants.
• Soils for avian and mammalian wildlife.
• Surface water for freshwater and marine aquatic biota.
• Surface water for aquatic-dependent avian and mammalian wildlife.
The ESVs can be found in Derivation of PFAS Ecological Screening Values (M. Grippo. J. Hayse. I. Hlohowskyj.
and K. Picel. Environmental Science Division. Argonne National Laboratory. September 2021).
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The ecological exposure pathw ay of concern is the potential for aquatic ecological receptors potentially exposed
to PFAS in surface water downgradient of OU1. Surface water samples were not collected for PFAS analysis;
however, this additional sampling may be considered.
Expected Progress Towards Meeting RAOs
Excavation of contaminated soil/sediment with placement under a cap has reduced risks to human health
associated with direct exposure to contamination. It has also reduced risks to animals and aquatic life. The Site is
currently not meeting the R AO to reduce migration of contaminated groundw ater. Progress is also not being made
on significantly reducing the mass of contaminants in groundw ater in and immediately adjacent to the quarry pits.
The GWTP is expected to reduce contaminant mass, regain hydraulic control of contaminated groundw ater and
reduce potential discharge to dow ngradient wetlands.
The presence of PFAS in groundwater might also affect progress toward meeting RAOs.
QUESTION C: Has any other information come to light that could call into question the protecti veil ess of
the remedy?
The expected impacts of climate change in New England pose increasing risks to contaminated sites. Increases in
air and water temperature, precipitation, flooding and periods of drought may result in altered fate and transport
pathways and exposure assumptions, impaired aquatic habitats, dispersal of contaminants, damage to remediation
related structures and ultimately, ineffective remedies. At coastal sites, saltwater impacts made more likely by
sea-level rise may cause corrosion of remediation equipment and impair restoration efforts. Increased frequency
of extreme weather events may cause damage or releases at sites, impairing remedial efforts where remedies have
not been adequately designed to protect against these risks.
The risks posed by climate change in New England are not expected to alter the protectiveness of the remedy at
the Sullivan's Ledge Superfund Site because the changes discussed do not impact protectiveness due to the low
risk of flooding at the Site.
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VI. ISSUES/RECOMMENDATIONS
Issues/Recommendations
OlJ(s) without Issues and Recommendations Identified in the FYR:
None
Issues and Recommendations Identified in the FYR:
OU(s): OU1
Issue Category: Remedy Performance
Issue: Although the GWTP was restarted in May 2023 follow ing a brief
shutdow n, groundwater data collected during the post-suspension monitoring
period showed that total VOC concentrations in groundwater are increasing and
migrating north tow ards the OU2 wetlands and extending off site to the east.
Recommendation: Evaluate whether hydraulic control has been reestablished
with the restart of the GWTP and take action, as necessary, to address the
migration of contamination in groundwater toward the OU2 wetlands and east of
OU 1.
Affect Current
Protectiveness
Affect Future
Protectiveness
Party
Responsible
Oversight Party
Milestone Date
Yes
Yes
PRP
EPA/State
9/1/2025
OU(s): OlJl.
OU2
Issue Category: Monitoring
Issue: PFAS has been detected in site groundwater above EPA RSLs. PFAS has
not been sufficiently evaluated to determine if there are additional impacts beyond
the OU 1 groundwater.
Recommendation: Collect additional PFAS samples in pore water, surface water
and/or sediment and determine if risk is posed to receptors from PFAS through
these exposure routes. If so. PFAS should be identified as a site COC.
Affect Current
Protectiveness
Affect Future
Protectiveness
Party
Responsible
Oversight Party
Milestone Date
No
Yes
EPA/State
EPA/State
9/1/2027
OU(s): OU 1
Issue Category: Remedy Performance
Issue: Detection limits for PCBs in some of the pore water samples were greater
than the toxicity benchmark of 0.014 (.ig/L total PCBs.
Recommendation: Determine if lower detection limits can be achieved to meet
the toxicity benchmark so that the ecological risk can be better assessed.
Affect Current
Protectiveness
Affect Future
Protectiveness
Party
Responsible
Oversight Party
Milestone Date
No
Yes
EPA/State
EPA/State
9/1/2025
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OU(s): OU2
Issue Category: Monitoring
Issue: 1.4-Dioxane has not been sampled for at the Site and the potential for an
ecological exposure scenario has not been ruled out.
Recommendation: Collect 1.4-dioxane samples in groundwater, pore water,
surface water and/or sediment and determine if risk is posed to receptors from
1,4-dioxane through these exposure routes. If so. 1.4-dioxane should be identified
as a site COC.
Affect Current
Protectiveness
Affect Future
Protectiveness
Party
Responsible
Oversight Party
Milestone Date
No
Yes
EPA/State
EPA/State
9/1/2027
Other Findings
The follow ing are recommendations that were identified during the FYR but do not affect current or future
protectiveness:
• The PMC representative noted that landfill gas monitoring data has been consistent from quarter to
quarter. Determine if a reduction in landfill gas monitoring frequency can be reduced from quarterly to
semiannual.
• Landfill gas monitoring wells on the eastern boundary of the Site show methane concentrations that
exceeded 25% of the LEL for methane. Evaluations of monitoring data indicate that methane may be
from a source outside the landfill. The adjacent property owner should be notified of the condition,
although LEL exceedances do not appear to be site related.
• Update the O&M Plan for OU1 to incorporate any changes needed due to the presence of the solar panels
installed in 2014.
• PFAS has been detected in overburden and bedrock groundwater at the Site. Sample the direct discharge
at MH-4 and influent/effluent at the GWTP for PFAS to determine if additional measures are needed to
prevent it from being discharged to the POTW.
• Continue to implement invasive species control in the OU 1/OU2 wetlands.
• Ensure all monitoring wells are properly secured.
• Repair minor erosion beneath the well pad at MW-8.
• Fill in any animal burrow s on the OU 1 cap in a timely manner, consistent with the Site's O&M Plan.
• GW-RBCs for protection of aquatic organisms should be incorporated into the O&M Plan as a screening
tool to determine if additional testing, particularly toxicity testing, is necessary when GW-RBCs are
exceeded. Evaluate whether site-specific RBCs need to be incorporated as Site cleanup levels.
• The City of New Bedford has indicated that many parts of the GWTP need repair or replacement since
they are nearing the end of their functional timeframe. Make repairs to the existing GWTP and/or explore
options for optimizing the GWTP.
• The City of New Bedford did not provide annual institutional control compliance reports to MassDEP and
EPA during this FYR period, as required by the 2014 GERE. Provide annual compliance reports to
MassDEP and EPA in January of each year.
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VII. PROTECTIVENESS STATEMENT
Operable Unit: 1
I'rotectiMMiess Stitlcmciil
Protectiveness Determination:
Protectiveness Deferred
Planned Addendum
Completion Date:
September 13, 2025
Protectiveness Statement: A protectiveness determination of the remedy at OU1 cannot be made at this
time until further information is obtained. Further information will be obtained by taking the follow ing
actions: evaluate whether hydraulic control has been reestablished with the restart of the GWTP and take
action, as necessary, to address the migration of contamination in groundwater toward the OU2 wetlands
and east of OU 1. It is expected that these actions will take approximately two years to complete, at which
time a protectiveness determination will be made and documented in a FYR Addendum, on or before
September 13, 2025.
Operable Unit:2
IVolCCtiMMK'SS Stiltl'llK'Ill
Protectiveness Determination:
Short-term Protective
Protectiveness Statement: The remedy for OU2 currently protects human health and the environment
because the construction of the remedy is complete, long-term monitoring is ongoing and institutional
controls are in place to prevent future human exposures to contamination. For the remedy to be protective
in the long term, the following action needs to be taken: collect PFAS and 1,4-dioxane samples in
groundwater, pore water, surface water and/or sediment and determine if risk is posed to receptors
through these exposure routes. If so. PFAS and 1.4-dioxane should be identified as a site COCs.
Silewide IVotiTliMMicss Sliiloinonl
Protectiveness Determination:
Protectiveness Deferred
Planned Addendum
Completion Date:
September 13, 2025
Protectiveness Statement: Because a protectiveness determination of the remedy at OU 1 cannot be made
at this time, a sitew ide protectiveness statement cannot be made until further information is obtained.
Further information will be obtained by taking the follow ing actions: evaluate whether hydraulic control
has been reestablished with the restart of the GWTP and take action, as necessary, to address the
migration of contamination in groundwater toward the OU2 wetlands and east of OU 1. It is expected
that these actions will take approximately two years to complete, at which time a protectiveness
determination will be made and documented in a FYR Addendum, on or before September 13, 2025.
VIII. NEXT REVIEW
The next FYR for the Sullivan's Ledge Superfund Site is required five years from the completion date of this
review.
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APPENDIX A - REFERENCE LIST
ATS DR. 2021. Toxicological Profile for Perfluoroalkyls. https://www.atsdr.cdc.gov/toxprofiles/tp200. pdf
City of New Bedford. 2020. Sullivan's Ledge Ground Water Treatment Plant Suspension Plan. January 2020.
City of New Bedford. 2020. Ground Water Treatment Plan Operations & Maintenance Manual, Sullivan's Ledge
Superfund Site. May 2020.
City of New Bedford. 2022 Environmental Monitoring Sampling and Results Report. Sullivan's Ledge Superfund
Site Operable Unit 2, New Bedford. Massachusetts. August 2022.
EPA. 1988. CERCLA Compliance with Other Laws Manual: Interim Final (Part 1). EPA/540/G-89/006. August
1988.
EPA. 2017. Transmittal of Update to the Adult Lead Methodology's Default Baseline Blood Lead Concentration
and Geometric Standard Deviation Parameters Memorandum, May 17. 2017. OLEM Directive 9285.6-56.
EPA. 2018. Vapor Intrusion Screening Level (VISL) Calculator. Office of Land and Emergency Management,
Office of Superfund Remediation and Technology Innovation (OSRTI). May 2018.
https://www.epa.gov/vaporintrusion/vapor-intrusion-screening-level-calculator
EPA. 2021. Provisional Peer-Reviewed Toxicity Values for Perfluorobutane Sulfonic Acid (PFBS) and Related
Compound Potassium Perfluorobutane Sulfonate. Office of Research and Development. Center for Public Health
and Environmental Assessment. EPA/690/R-21/001F. 2021.
EPA. 2021. Recommendations on the Use of Chronic or Subchronic Noncancer Values for Superfund Human
Health Risk Assessments Memorandum, May 26. 2021. Office of Land and Emergency Management,
Washington. DC. 2021.
EPA. 2021. Human Health Toxicity Values for Hexafluoropropylene Oxide (HFPO) Dimer Acid and Its
Ammonium Salt (CASRN 13252-13-6 and CASRN 62037-80-3) Also Known as "Gen-X Chemicals." Office of
Water. Health and Ecological Criteria Division. Washington. DC. October 2021.
EPA. Integrated Risk Information System (IRIS). Available at https://www.epa.gov/iris
EPA. Provisional Peer-Reviewed Toxicity Values. Available at https://www.epa.gov/pprtv
EPA. Regional Screening Level Tables. Available at https://www.epa.gov/risk/regional-screening-levels-rsls-
generic-tables
EPA Region 1. 1989. Record of Decision Remedial Alternative Selection. Sullivan's Ledge. New Bedford.
Massachusetts. June 1989.
EPA Region 1. 1991. Record of Decision Remedial Alternative Selection. Sullivan's Ledge Superfund Site.
Middle Marsh Operable Unit, New Bedford. Massachusetts. September 1991.
EPA Region 1. 1995. Explanation of Significant Differences. Sullivan's Ledge Superfund Site. Operable Unit I.
July 1995.
EPA Region 1. 2000. Explanation of Significant Differences. Sullivan's Ledge Superfund Site. Operable Unit I.
September 2000.
A-1
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EPA Region 1. 2003. Explanation of Significant Differences, Sullivan's Ledge Superfund Site. Operable Unit I.
September 2003.
EPA Region 1. 2008. Second Five-Year Review Report for Sullivan's Ledge Superfund Site. Bristol County.
Massachusetts. September 2008.
EPA Region 1. 2013. Third Five-Year Review Report for Sullivan's Ledge Superfund Site. Bristol County.
Massachusetts. September 2013.
EPA Region 1. 2018. Fourth Five-Year Review Report for Sullivan's Ledge Superfund Site. Bristol County.
Massachusetts. September 2018.
M. Grippo. J. Hayse. I. Hlohowskyj. and K. Picel. 2021. Derivation of PFAS Ecological Screening Values.
Environmental Science Division. Argonne National Laboratory. September 2021.
Nobis. 2023. Tier 1 Stage 2A Organic Data Review (and associated results for PFAS). April 11. 2023.
OBG. 2019. Sullivan's Ledge Superfund Site - June 2019 Landfill Gas Monitoring. July 12, 2019.
Rani boll. 2019. Sullivan's Ledge Superfund Site - September 2019 Biennial Surface Water and Sediment
Monitoring. November 18. 2019.
Ramboll. 2020. Sullivan's Ledge Superfund Site - Post-Suspension Performance Monitoring Sampling Plan. June
2020.
Ramboll. 2020. Sullivan's Ledge Superfund Site - Post-Suspension Performance Monitoring Event 1 Report.
December 22, 2020.
Ramboll. 2020. Sullivan's Ledge Superfund Site - Post-Suspension Performance Monitoring Event 2 Report.
March 24. 2021.
Ramboll. 2022. Sullivan's Ledge Superfund Site - Post-Suspension Performance Monitoring Event 5 Report.
May 6. 2022.
Ramboll. 2022. Sullivan's Ledge Superfund Site - Post-Suspension Performance Monitoring Event 5A Report.
July 28. 2022.
Ramboll. 2022. Sullivan's Ledge Superfund Site - Post-Suspension Performance Monitoring Event 6 Report.
December 7. 2022.
Ramboll. 2022. Sullivan's Ledge Superfund Site - December 2022 Landfill Gas Monitoring Report. December
21,2022.
A-2
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APPENDIX B - SITE CHRONOLOGY
Table 6-1: Site Chronology
Event
Date
Quarrying operations took place on site
1840s to 1921
The Citv of New Bedford acquired site land through a tax title foreclosure
1935
The quarry pits were used for waste disposal
1930s to carlv 1970s
The Massachusetts Department of Public Works identified capacitors in the subsurface
during advancement of gcotcchnical borings
EPA conducted an air monitoring program for the greater New Bedford area
1982
EPA installed groundwater monitoring wells around the Site and confirmed contamination
1983
EPA listed the Site on the NPL
September 1984
NUS Corporation completed the OU1 Phase 1 Rl report
September 1987
Ebasco Services. Inc. completed the OU2 Final RI/FS report
January 1989
EPA completed the OU 1 phased RI/FS and issued the OU 1 ROD
June 1989
Mctcalf & Eddy, Inc. completed the OU2 Final Rl - Additional Studies of Middle Marsh
April 1991
Mctcalf & Eddy, Inc. completed the OU2 FS for Middle Marsh
Mav 1991
EPA issued the OU2 ROD
September 1991
A Consent Decree for OU2 was lodged in U.S. District Court in Massachusetts
January 1993
EPA issued an ESD for OU 1. modifying the remedy so that treatment would no longer be
required for soil and sediments to be covered by the landfill cap
July 1995
EPA approved the 100% remedial design for OU 1
June 1997
Start of on-site construction at OU 1
March 1998
Start of on-site construction at OU2
April 1999
Startup of the OU 1 groundwater collection and treatment svstcin
December 1999
EPA issued a second ESD for OU 1. substituting a slurry wall for the shallow collection
trench along a section of the site boundary and culvcrting a section of the U nnained Stream
instead of lining it in concrete
September 2000
URS Corporation completed the Final Remedial Construction Report for OU2
August 2001
O'Brien & Gere Engineers completed the Remedial Construction Report for OU 1
March 2002
EPA approved the OU2 Construction Completion Report and OU 1 Construction Completion
Report
January 2003
EPA issued an ESD adding Solid Waste regulations as an ARAR and requiring mitigation of
a landfill gas migration issue
September 2003
EPA issued the Site's first FYR Report
September 2003
Institutional controls arc implemented for Citv of New Bedford propcrtv
2004
The fifth vcar of post-construction wetland monitoring took place
2006
EPA issued the Site's second FYR Report
September 2008
The first vcar of long-term wetland monitoring took place
2011
EPA issued the Site's third FYR Report
September 2013
The Site achieved the Sitewide Rcadv for Anticipated Reuse performance measure
May 2014
EPA completed an Optimization Review Report
March 2016
EPA issued the Site's fourth FYR Report
September 2018
The GWTP was shut down and the scvcn-vcar PMP began
July 2020
The GWTP was restarted in response to increasing VOC concentration in groundwater and
migration of the plume
May 2023
B-l
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APPENDIX C - 1989 ROD INDICATOR COMPOUNDS
TAILS i
INDICATOR COMPOUNDS
SUUJVAirS LEDGE STTE
NEW tEDFORO. MASSACHUSETTS
2-butanon*
4-fn «thyl -2-p»m»non«
b«nx«nc
toluer*
xyfcnts
ethyl ixnitne
chlorob«ra«n»
1,2-dichtoroetharw
Pwrtachlerophtrwi
BaM/N«utnl E*ir«t»W«s
bij(2-ethylhexyt)phth«late
pdycytlit »rom»tic hydroc»rbon» (PAHs)
•cenapthane
acanapthyiane
anthraeerw
banxo(«)»nthraca«a
battto(t>)fluorarrth«na
banzo(k)fIuoramhan«
b«rao{g»h»i)p«ryien#
b»ruo(*)pyr»r>«
chfjwrw
di btnzo(« ,h) anthracar*
ftuoranthane
fluorcna
idano( 1,2»3-ed}pyrer«
pb#rt»rtthf«r»
pywoe
t»phth#l#n#
2<-mathylnaphthalana
2» - & i t
cniofOTprm
mathylana chJorida
styrana
SEMlrVOLATHE ORGANIC
Add Ewactabfts
1,2*dichtorobanzena
1 J-dichlorobanxana
1,4-dichlerolxraen#
1 ,2.4-trichlorobenzafla
n-nitro*odimathyiamina
rv nitroiod i p hanyiam i r*
bis(2-chloroathyl)tthar
dibartzofuran
ssnseBEas
PCB-1tt1€
fd-1221
PO-1232
PCB-1242
tarium
Bt#n§ar»«#
mercury
nickel
KB-1248
PCB-1254
KB-1260
»l«*r
todium
line
C-l
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APPENDIX D - PMP MONITORING LOCATIONS
figure D-l: Performance Monitoring Sampling Overburden Well Sampling Map
FIGURE NO. 1
LEGEND
MONITORING WELL LOCATION
® RECOVERY WELL LOCATION
SHALLOW COLLECTION TRENCH
SAMPLE LOCATION (PUMP STATION)
I. !\\\S| APPROXiMATE LOCATION OF
THE SLURRY WALL
PERFORMANCE MONITORING SAM PLING
¦ APPROX5MATE LOCATION OF THE
TRIBUTARY AND UNNAMED STREAM
(TEMPERATURE SURVEY AREA)
(DASHED WHERE INFERRED)
SULLIVAN'S LEDGE
SUPERFUND SITE
NEW BEDFORD, MASS.
PERFORMANCE MONITORING
SAMPLING
OVERBURDEN WELL
SAMPLING MAP
200 0 200
r=20O'
Rt£ NO- 5SC9.73GS4.cn 1
OCTOBER 2019
O'BRIEN & GERE ENGINEERS, INC.
Source: Final PMP Sampling Plan, July 2020. Prepared by O'Brien & Gere Engineers, Inc.
P2--9
PZ-3 .
+ MYWJA
MW-7A * 1
If
n
11 PZ-1
• MW-8A
5A
D-l
-------
igure D-2: Performance Monitoring Sampling Shallow Bedrock Well Sampling Map
FIGURE NO. 2
LEGEND
+ MONITORING WELL LOCATION
® RECOVERY WELL LOCATION
SHALLOW COLLECTION TRENCH
SAMPLE LOCATION (PUMP STATION)
~| APPROXIMATE LOCATION OF
THE SLURRY WALL
PERFORMANCE MONITORING SAMPLING
SULLIVAN'S LEDGE
SUPERFUND SITE
NEW BEDFORD, MASS
PERFORMANCE MONITORING
SAMPLING
SHALLOW BEDROCK
WELL SAMPLING MAP
200 0 200
r=2oo'
Fi_= NO. SS0S.73BS4.0C2
OCTOBER 2013
Source: Final PMP Sampling Plan, July 2020. Prepared by O'Brien & Gere Engineers, Inc.
MW-a
D-2
-------
figure D-3: Performance Monitoring Sampling Intermediate Bedrock Well Sampling Map
FIGURE NO. 3
LEGEND
MONITORING WELL LOCATION
® R ECOVERV WELL LOCATION
SHALLOW COLLECTION TRENCH
SAMPLE LOCATION (PUMP STATION)
| | APPROXIMATE LOCATION OF
THE SLURRY WALL
PERFORMANCE MONITORING SAMPLING
SULLIVAN'S LEDGE
SUPERFUND SITE
NEW BEDFORD, MASS.
PERFORMANCE MONITORING
SAMPLING
INTERMEDIATE BEDROCK
WELL SAMPLING MAP
200 0 200
1 "=200'
FiS NO. S5D9.73C54.DC3
OCTOSE3 2019
Source: Final PMP Sampling Plan, July 2020. Prepared by O'Brien & Gere Engineers, Inc.
PZ.17I
D-3
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"igure D-4: Performance Monitoring Sampling Deep Bedrock Well Sampling Map
FIGURE NO. 4
SULLIVAN'S LEDGE
SUPERFUND SITE
NEW BEDFORD, MASS
PERFORMANCE MONITORING
SAMPLING
DEEP BEDROCK
WELL SAMPLING MAP
SHALLOW COLLECTION TRENCH
SAMPLE LOCATION (PUMP STATION)
| x:\ | APPROXIMATE LOCATION OF
THE SLURRY WALL
PERFORMANCE MONITORING SAMPLING
LEGEND
MONITORING WELL LOCATON
RECOVERY WELL LOCATION
Source: Final PMP Sampling Plan, July 2020. Prepared by O'Brien & Gere Engineers, Inc.
D-4
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Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Raniboll.
D-5
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APPENDIX E - PRESS RELEASE
= An official website of the United State government
Here's how y&u knam
United States
Environmental Protection
Agency
MENU
Search EPA.gov
News Releases: Region 01 ewsreleises/s-earch/press,officc/regk>r»-ttt-
EPA to Review Cleanups at Six
Massachusetts Superfund Sites
this Year
January 18,2023
Contact Information
David Jcegan idccgan.davG@epa.gov)
i Gli') 913-101/
BOSTON (Jan. 18, 2023) - "he J.S. Lnvironmental Protection Agency
E-l
-------
' he SuporfLnd Sites where CPA will conduct rive-Year Reviews in 2C23 arc listed below
with web links that provide detailed information on site status as well as past
assessment and cleanup activity. Once the : ivc-V'ear Review is complete, its Endings will
be posted to the website in a final report.
fine-Year Reviews of Superfund sites in Massachusetts to be completed in 2023:
Iron Horse Park , Billcrica
Plymouth Harbor CLC , Plymouth
Re-Solve, Inc.,, Dartmouth
Shpack Landfill , Norton,"'Attleboro
Sullivan's Ledge , New Bedford
Federal Facility
Otis Air National Guard Base/Camp Edwards , Falmouth, Bourne, Sandwich, Mashpee
Mot* information:
The Superfund program, a federal program established by Congress in 19SC,
investigates and cleans up the most complex, uncontrolled, or abandoned hazardous
waste sites in the country and EPA endeavors to facilitate activities to rctt rn them to
productive use. in total, there are 123 Superfund sites across New tngland.
Superfund and other cleanup sites in New England
Contact Us •+ttps://cpa,|-ov/n£*srai6as-€- to ask a question, provide feedback,
or re port a problem.
LAST UPDATED ON JANUARY 18,2023
E-2
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APPENDIX F - INTERVIEW FORMS
SULLIVAN'S LEDGE SUPERFIJND SITE
FIVE-YEAR REVIEW INTERVIEW FORM
Site Name: Sullivan's Ledge
EPA ID: MAD980731343
Subject name: Dorothy Allen Subject affiliation: MassDEP
Subject contact information: dorothy.t.allen@state.ma.us
Interview date: 4/12/2023
Interview time: p.m.
Interview format (select one): In Person Phone Mail Email X Other:
Interview category: State Agency
1. What is your overall impression of the project, including cleanup, maintenance and reuse activities (as
appropriate)'.'
The treatment plant is aging and needs continued repairs and upgrades. Before shutdow n it contained the
plume and provided appropriate treatment. The active gas collection system needs monitoring but captures
most of the disposal area gas. Since the shutdown the groundwater contamination has spread and no longer
meets the performance standards. At present the treatment plant needs to re-start and to pump and treat
adequate volume of groundwater to draw back and once again contain the plume of contamination. The Site is
being properly re-used as a golf course, wetland habitat and PV electricity generating location.
2. What is your opinion of the current performance of the remedy in place at the Site'.'
The current remedy of groundw ater pump and treat at the site needs to be re-started. The recent shutdow n,
however, has demonstrated that the pump and treat remedy has not addressed the source of the contamination
and that to contain the plume the treatment would need to operate for an indeterminate period of time to meet
the performance standards stipulated in the ROD. Further, it is not clear if these standards are appropriate for
the site since they are not risk based. A re-examination of the performance standards for the site and design of
a more appropriate long-term remedy is necessary.
3. Are you aw are of any complaints or inquiries regarding site-related environmental issues or remedial
activities from residents in the past five years?
No.
4. Has your office conducted any site-related activities or communications in the past five years? If so. please
describe the purpose and results of these activities.
No.
5. Are you aware of any changes to state laws that might affect the protectiveness of the Site's remedy'.'
No.
6. Are you comfortable with the status of the institutional controls at the Site'.' If not. what are the associated
outstanding issues'.'
Yes.
F-l
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7. Are you aware of any changes in projected land use(s) at the Site'.'
No.
8. Do you have any comments, suggestions or recommendations regarding the management or operation of the
Site's remedy'.'
EPA and MassDEP should negotiate with the PRPs to perform site specific risk assessment that will allow for
the development of new performance standards that will be used to design and implement a new remedy in
place of continuation of existing remedy. A ROD amendment and updated CD may be required in the future.
9. Do you consent to have your name included along with your responses to this questionnaire in the FYR
report'.'
Yes.
F-2
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.. /an's Ledge Superfuttd Site 2023 Five-Year Review
Response to interview Questions - Marilyn Wade (Brown arid Caldwell on behalf of the PMC)
1, What Is your overall Impression of the project, including cleanup., maintenance and reuse
activities (as appropriate)?
Overall, the remedy has been successful In reducing contaminant levels at this historic disposal
site arid restoring the wetland area that was part of the remedial action,
2, What Is your opinion of the current performance of 'the remedy in plac©' at the Site?
The overall remedy performance since the last 5-year review has been productive. The remedy
components include the Groundwater Treatment Plant (GWTP), recovery welts* and landfill cap.
The recovery wells, in conceit with the landfill cap, provide plume capture and successful
minimization of contaminant migration to the restored downgradient stream and wetland. The
GWTP provides treatment of recovered groundwater prior to discharge to the sanitary sewer.
The operation ot me Site's GW1K which began in December 139-9, and landfill cap
accomplished remedial goals and contaminant reduction to the point where GWTP operation was
suspended on iulf 24, 2020 to begin a seven-fear course of performance monitoring from 2020
to 202?, Based on data from the first, two pars of performance monitoring, groundwater
chlorinated volatile organic solvent concentrations rebounded since QWFP suspension. In fall of
202:2, the PMC Group recommended that the GWTP restart because the plant's operation is
demonstrated to effectively contain and reduce groundwater contaminants, The GWTP restart is
scheduled for May 1, 2023,
3, What have 'be®" the effects of this Site on the iunroundlng community and neighborhood, if any?
There are no known effects of this Site en the surrounding community and neighborhood,
4, Ate you aware of any complaints or inquiries regarding environmental issues or the remedial
action from residents since implementation of the cleanup?
No,
5, What monitoring data tie you reguiar|> collect? What are the key trends te 9m data you're
familiar with regarding contaminant levels and or system performance that are being
documented o\er true at Ihe S :W
Regularly collected data includes depth to groundwater in the monitoring wells, groundwater
samples for analysis of chlorinated volatile organic compounds and/or PCBs from selected
monitoring well locations, and data associated with landfill gas men itoting (tP6|,
Data collected during the LPS monitoring events is consistent from Quarter to Quarter. While
methane is delected at gas monitoring well GM-18, multiple lines of evidence from collected
data support that the methane is from an of-site source. The remainder of the U-ti monitoring
data indicate that the LF6 system continues to operate effectively and that no airborne impacts
are observed in ambient air. Given the consistency and results obtained during multiple years of
quarterly LPS monitoring, the Group suggests reducing the LPS monitoring events to semi-annual
in the upcoming 5-year period.
The key groundwater data trend at the beginning of the 5-fear period showed stable
concentrations in the groundwater wells being monitored arid concentrations were consistently
below the performance goal of 10,000 ug/L total VOCs. Once GWTP operations were suspended
and the performance monitoring period began, groundwater VOC concentrations were observed
F-3
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Sullivan's Ledge Superftmd Site 2023 Five-Year Review
to Increase in select wells and in particular subsurface depth horizons. The most significant
rebounding has occurred in the deep bedrock fracture zone. However, while concentrations in
select, wells proximate to the recovery wells have been Increasing, the downgradient sentinel
wells remain unimpacted and have riot exhibited extended lateral migration.
As a result, the GWTP is being turned back on-line. The anticipated resulting trend is a decrease
in ground water concentrations will lime as the recovery wefts' cone of influence is re-
established and expands to provide containment.
In March 2023, EPA and the PMC collected groundwater samples for poly-and per-fluoroalkyl
substances (PFAS) per the 2018 five-year review recommendation. No results were available
when this report, was submitted,
6. What is the approximate frequency of on-site O&M at this time'? Pleas# describe staff
responsibilities and activities associated with it.
Operation and maintenance fQ&Ml of the Site and remedies is performed by the City's
Department of Pubic Infrastructure (DPI), Prior to the plant suspension in 2020, the PMC group
understood that DPI operated and maintained the GWTP in accordance with the GWTP O&M
Manual (updated twice during this 5-year review period, in April 2019 ar»J srh*' •; febada
20:20); inspected and maintained the LF«Q system, and inspected and maintained the landfill
cap.
During the shutdown period, from July 2020 to the present, DPI Implemented a post-shutdown
inspection, testing and maintenance program and quarterly reporting, the goals of which were to
confirm that the plant remained viable and able to restart should the performance monitoring
indicate that is necessary. We understand that the DPI is currently working through the steps to
reinstall and test aspects of the system in preparation tor a May 2023 restart. Once the GWTP is
operating and following initial pre-and post-restart monitoring and calibration, it is anticipated
that operation and maintenance by DPI and associated monitoring by the Group will return to
pre-suspension levels,
7. Hem there been any significant changes in site O&M requirements, maintenance1 schedules or
sampling routines in fie last five years? if so, tto they affect the protectfveness o# effectiveness
of the remedy? Please describe Lfwngw. ard Impacts,
There have been no significant changes to the operation and maintenance requirements for the
landfill gas system, the cap or the restored wetlands.
The GWTP shutdown in 202.0- resulted in significant changes, to the required GWTP O&M. The
treatment plant O&M transitioned from the scope of work in the February 2020- O&M manual to
a post-shutdown scope and schedule that Included quarterly reviews of the various GWTP system
components, with the goal of assurance that they would be functional should; the GWIP need to
be restarted. In addition, the site monitoring .schedule was significantly changed. The sampling
round immediately prior to the shutdown included IS sampling locations, four of which were
surface water and sediment samples, which have since been replaced by the pore water
samples. Between the time the plant started in 1999 and the 2018 sampling round, .sampling
frequency was reduced from quarterly to semi-annually by agreement with EPA.
The seven years- of performance monitoring that was established in connection with the ow 11*
shutdown (described in the Post Suspension Performance Monitoring Sampling Plan- (June 12,
2020} (June 2020 PMP plan}- included more sampling points, but a gradually decreasing
F-4
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Sullivan's, Ledge Superliindi Site 2023 Rve-Year Review
frequency of sampling and analysis. The June 2020 PMP plan required' quarterly sampling in year
1, semiannual sampling in years .2 and 3, arid annual sampling in years 4 to Given the
increasing trends, in VOC results in year i« the sampling regimen was increased in year 2 arid the
first part of year 3 to be quarterly sampling as well. The June 2020 PMP plan included
significantly more sampling points than pre*GW!F shutdown sampling, with as many as 37
sampled in any one event As part of the June 2020 PMP plan, a stream temperature survey was
completed, and four pare water sampling locations were added to the program.
Since the plant shut down in June 2020, the Group has worked cooperatively with EPA arid
MassDCP to modify the sampling plan in response to their recommendations. Doing so was
done with objective of maintaining a protective and effective remedy.
8. Hive there been unexpected 0&M difficulties or costs at the Site since in the last five pars? If
please provide dtetnils*
Sampling costs after the GWTP shutdown were higher than when the GWTP was operating. Pre
GWTP shutdown, sampling was semi-annuaiiy, with IS sampling locations included in the most
recent {2018) O&M event. The final 2020 PMP plan provided for quarterly sampling during the
first year alter GWTP shutdown, followed by semi-annual monitoring In years 2,3 and 4, dropping
clown to annual sampling in years 5,6, and 7. There were as many as 37 points at each event.
Monitoring costs escalated more when rather than semiannual sampling in Year 2 and 3,
quarterly mentoring was required I* EPA, resulting in significant unexpected performance
monitoring costs.
9. What are the annual system operatton/O&M costs far GtJi {incurred to* the Sullivan's Ledge s
Group) since the preview five-year review {2018 to present)?
The annual system costs for QUI for the Five-Year Period are summarized in the table below.
This dees riot include GWTP O&M undertaken by the City.
Approximate Monitoring, Engineering, Capital Improvement,
Administrative and Legal Costs
Date Cost
January 1 to December 31,2018 $566,518,
January 1 to December 31,2019 $373,030
January 1 to December 31,2020 $327,598
January 1 to December 31,2021 $315,240
January 1 to December 31,2022 $529,869
10. Are you aware of any opportunities to optimize O&M activities or sampling efforts? Please
describe changes and any resulting or desired cost savings or improved efficiencies.
We see an opportunity to optimize sampling efforts after the 6WIP is restarted with semi-annual
sampling at a similar subset of wells that were monitored prior to the GWTP shutdown.
11. Do you hawe any comments, suggestions or recommendations regarding O&M activities and
schedules at the Site?
The PMC recommends the landfill gas monitoring be reduced from quarterly to semi-annually.
Additionally, once the 6TWP restart period is complete, the PMC recommencH returning to a
routine semi-annual monitoring program with a reduced number of locations.
F-5
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SLwawtfli S Ledge Superfurtd Site 2023 Five-Year Review
12, Do you consent to haw pur name included along wfth your responses to this questionnaire in
fie FYR report*?
Yes.
F-6
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SULLIVAN'S LEDGE SUPERFUND SITE
FIVE-YEAR REVIEW INTERVIEW FORM
Site Name: Sullivan's Ledge
EPA ID: MAD980731343
Subject name: James Costa
Subject affiliation: Sullivan's Ledge GWTP,
City of New Bedford
Subject contact information:
Interview date: March 22, 2023
Interview time: Not applicable
Interview location: Not applicable
Interview format (identify one): In Person
Phone Mail Email Other:
Interview category: Local Government
1. Are you aware of the historic environmental issues at the Site and the cleanup activities that have taken place
to date'.'
Yes. for the past 20+ years, the City has been responsible for treating contaminated groundwater on the Site
caused by improper dumping on the grounds in the past.
2. Do you feel well-informed regarding the Site's activities and remedial progress'.' If not. how might EPA
convey site-related information in the future'.'
Yes. the Site's activities and remediation are primarily handled internally by the City and information is
reported by the EPA as relevant.
3. Have there been any problems with unusual or unexpected activities at the Site or the surrounding area, such
as emergency response, vandalism or trespassing'.'
There was one documented occurrence of the outer fence being damaged by car accident, but no vandalism
was discovered.
4. Are you aware of any changes to state laws or local regulations that might affect the protectiveness of the
Site's remedy'.'
We are not aw are of any changes to state law s or local regulations that might have this effect.
5. Are you aw are of any changes in projected land use(s) at the Site'.'
We are not aw are of any changes in projected land use at the Site.
6. Are there any groundw ater wells in addition to or instead of accessing city/municipal water supplies for the
golf course'.' If so. for what purpose*s) is the well used'.'
Unknown.
7. Has EPA kept involved parties and surrounding neighbors informed of activities at the Site'.' How can EPA
best provide site-related information in the future'.'
Yes. to the best of our know ledge.
F-7
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8. What monitoring data do you regularly collect'.' What are the key trends in the data you're familiar with
regarding contaminant levels and or system performance that are being documented over time at the Site'.'
When the facility is operational, the sludge produced is tested for PCBs and the groundwater coming into and
being treated within the plant is tested for PCBs. VOCs and metals. Monitoring is conducted on the collection
trench quarterly for PCBs. suspended solids, metals, cyanide and VOCs. Data trends are not typically
analyzed in-house.
9. What is the approximate frequency of on-site O&M at this time'.' Please describe staff responsibilities and
activities associated with it.
The facility is not currently operational but will be returned to operation in May 2023. Current O&M is being
conducted consistently and is focused on repairs and maintenance required for the facility to function
effectively. All components of the facility are being tested and repaired or replaced as appropriate.
10. Have there been any significant changes in site O&M requirements, maintenance schedules or sampling
routines in the last five years? If so. do they affect the protectiveness or effectiveness of the remedy'.' Please
describe changes and impacts.
The facility was not operational for approximately two years. Sampling and maintenance have been
conducted on a consistent schedule when the facility is operational, with sampling being conducted a
minimum of once per month for the facility's effluent, and maintenance being conducted as needed. Parts
requiring frequent preventative maintenance are incorporated in a monthly routine repair list.
11. Have there been unexpected O&M difficulties or costs at the Site since in the last five years? If so. please
provide details.
O&M difficulties and costs have arisen in the form of many parts reaching the end of their functional
timeframe and the cost of numerous repairs and part replacements for many pieces of equipment that are now
obsolete.
12. What are the annual system operation/O&M costs for OU 1 (incurred by the City of New Bedford) since the
previous five-year review (2018 to present)'.'
This information is not readily available and a request w ill be made to the City's Purchasing Dept. for
historical records.
13. Do you have any comments, suggestions or recommendations regarding the project'.'
The plant needs extensive repairs and part replacements due to its operational timeframe and would benefit
from an overhaul or replacement of the facility.
14. Do you consent to have your name included along with your responses to this questionnaire in the FYR
report'.'
Yes. James Costa. Superintendent of Wastewater
F-8
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APPENDIX G - DATA REVIEW FIGURES
igure G-l: Overburden Groundwater Contour PMP Event 6, August 2022
LEGEND
MONITOR1NK3 WELL LOCATION
SHALLOW COLLECTION TRENCH
NM APPROXIMATE LOCATION OF THE
SLURRY WALL
[79.43] GROUNDWATER ELEVATION (FT)
70 GROUNDWATER ELEVATION CONTOUR
(DASHED WHERE INFERRED)
[NM] NOT MEASURED
[ljg£fi| INDICATES GROUNDWATER ELEVATION
1 1 FROM SHALLOW BEDROCK
SULLIVAN'S LEDGE SUPERFUND SITE
NEW BEDFORD. MASSACHUSETTS
PZ-19
+
PZ-3 .
+ M'.7-9A
OVERBURDEN GROUNDWATER
CONTOUR
PMP EVENT 6
(08-01-22)
FIGURE 06
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
G-l
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figure G-2: Shallow Bedrock Groundwater Contour PMP Event 6, August 2022
|MW-'I3|
©W&TER LEVELS NO"
GROU-NDWATH? l.EVH^ REF^ESE^
CA'-E^ebRDSN- ZONES AND WERE USED
200'
Sill
Source: Sullivan's Ledge Superfimd Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
G-2
-------
figure G-3: Intermediate Bedrock Groundwater Elevations PMP Event 6, August 2022
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
G-3
-------
figure G-4: Deep Bedrock Groundwater Elevations PMP Event 6, August 2022
"4" .LLCCATiOlV
RECOVERY WELL LOCATION
• - SHALLOW COLLSCTK5M TRENCH
>M APPROXiMAT'S. LOCATiON CF THE
SLURRY WALL..
[79.43} <3R
-------
"igure G-5: Historic Total VOCs Prior to GWTP Startup, November-December 1999 - Overburden Wells
LEGEND
—--- SHALLOW COLLECTION TRENCH
[SSSSSS1 APPROX imate location of the
SLURRY WALL
PERFORMANCE MONITORING
SAMPLING LOCATION
PERFORMANCE MONITORING
SAMPLING LOCATION AND
POINTS OF EVALUATION (POE)
MONITORING WELL LOCATION
(NOT INCLUDED IN PMP PROGRAM)
® RECOVERY WELL LOCATION
(DATA NOT INCLUDED)
(3440} TOTAL VOCs CONCENTRATIONS (ugA.)
)TAL VOCs CONCENTRATIONS lua/T-l
• <10
>10-1000
£ >1000-5000
^ >5000-10000
>10000-50000
>50000
NOTES:
" - DATA OBTAINED FROM MARCH 2001 EVENT
ND - NON-DETECT
NS - NOT SAMPLED
HISTORIC TOTAL VOCs
NOVEMBER-DECEMBER 1999
PRIOR TO GWTP STARTUP
OVERBURDEN WELLS
SULLIVAN'S LEDGE SUPERFUND SITE
NEW BEDFORD. MASSACHUSETTS
K§llki
SEPTEMBER 2022
FIGURE 10A
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
G-5
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"igure G-6: Total VOCs Concentrations PMP Event 1, October 2020, and PMP Event 6, August 2022 - Overburden Wells
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
LEGEND
SHALLOW COLLECTION TRENCH
APPROXIMATE LOCATION OF THE
SLURRY WALL
PERFORMANCE MONITORING
SAMPLING LOCATION
PERFORMANCE MONITORING
SAMPLING LOCATION AND
POINTS OF EVALUATION (FOE)
MONITORING WELL LOCATION
(NOT INCLUDED IN PMP PROGRAM)
® RECOVERY WELL LOCATION
(DATA NOT INCLUDED)
(3440) TOTAL VOCs CONCENTRATIONS (ug.L)
TOTAL VOCs CONCENTRATIONS I'lhULI
ft <10
# >10-1000
0 > 1000-5000
£ >5000-10000
>10000-50000
>50000
*' - DATA OBTAINED FIRST TIME SAMPLED
DURING PMP EVENT 4
ND - NON-DETECT
NS - NOT SAMPLED
PMP EVENT 6 NOTES:
ND - NON-DETECT
NS - NOT SAMPLED
250 0 250
TOTAL VOCs CONCENTRATIONS
PMP EVENT 1 OCTOBER 2020
AND PMP EVENT 6 AUGUST 2022
OVERBURDEN WELLS
SULLIVAN'S LEDGE SUPERFUND SITE
NEW BEDFORD. MASSACHUSETTS
SEPTEMBER 2022
FIGURE 10B
PMP EVENT 6 AUGUST 2022
PMP EVENT 1 OCTOBER 2020
G-6
-------
Legend:
VMUQARI
(7.B)*,Vsj
mmwm
I (ND) |
figure G-7: Historic Total VOC Concentrations Isocontour Map, November-December 1999 Prior to GWTP Startu
p - Overburden Wells
LEGEND
i SHALLOW COLLECTION TRENCH
tsSSSSSl APPROXIMATE LOCATION OF THE
SLURRY WALL
¦4" PERFORMANCE MONITORING
SAMPLING LOCATION
^ PERFORMANCE MONITORING
SAMPLING LOCATION AND
POINTS OF EVALUATION (POE)
MONITORING WELL LOCATION
(NOT INCLUDED IN PMP PROGRAM)
® RECOVERY WELL LOCATION
(DATA NOT INCLUDED)
(3440) TOTAL VOCs CONCENTRATIONS (ug/L)
TOTAL VOCs CONCENTRATIONS fug/LI
• <10
# >10-1000
0 > 1000-5000
>5000-10000
>10000-50000
>50000
HISTORIC TOTAL VOC
CONCENTRATIONS ISOCONTOUR MAP
NOVEMBER-DECEMBER 1999 PRIOR
TO GWTP STARTUP OVERBURDEN
WELLS
SULLIVAN'S LEDGE SUPERFUND SITE
NEW BEDFORD. MASSACHUSETTS
FIGURE 10C
- Isocontour (dashed when inferred)
110 - Total VOCs concentration (ug/L)
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
G-7
-------
Figure G-8: Total VOC Concentrations Isocontour Map, PMP Event 1, October 2020, and PMP Event 6, August 2022 - Overburden Wells
I Legend:
Isocontour (dashed when inferred)
10- Total VOCs concentration 1 APPROXI MATE LOCAT1 ON OF THE
SLURRY WALL
*
*
-*¦
®
(3440)
PERFORMANCE MONITORING
SAMPLING LOCATION
PERFORMANCE MONITORING
SAMPLING LOCATION AND
POINTS OF EVALUATION (POE>
MONITORING WELL LOCATION
(NOT INCLUDED IN PMP PROGRAM)
RECOVERY WELL LOCATION
(DATA NOT INCLUDED)
TOTAL VOCs CONCENTRATIONS (ug/L)
TOTAL VOCs CONCENTRATIONS luq/Lt
ft <10
# >10-1000
0 >1000-5000
>5000-10000
>10000-50000
>50000
" - DATA OBTAINED FIRST TIME SAMPLED
DURING PMP EVENT 4
ND - NON-DETECT
NS - NOT SAMPLED
PMP EVENT 6 NOTES:
ND - NON-DETECT
NS - NOT SAMPLED
250 0
250
TOTAL VOC CONCENTRATIONS
ISOCONTOUR MAP
PMP EVENT 1 OCTOBER 2020 AND
PMP EVENT 6 AUGUST 2022
OVERBURDEN WELLS
SULLIVAN'S LEDGE SUPERFUND SITE
NEW BEDFORD. MASSACHUSETTS
SEPTEMBER 2022
FIGURE 10D
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
G-8
-------
igure G-9: Historic Total VQCs Prior to GWTP Startup, November-December 1999 - Shallow Bedrock Wells
LEGEND
------ SHALLOW COLLECTION TRENCH
APPROXIMATE LOCATION OF THE
SLURRY WALL
~
~
PERFORMANCE MONITORING
SAMPLING LOCATION
PERFORMANCE MONITORfNG
SAMPLING LOCATION AND
POINTS OF EVALUATION (POE)
MONITORING WELL LOCATION
(NOT INCLUDED IN PMP PROGRAM)
RECOVERY WELL LOCATION
(DATA NOT INCLUDED)
TOTAL VOCs CONCENTRATIONS (ug/L)
Cs CONCENTRATIONS fuft
<10
>10-1000
>1Q00-5®0
>5000-10000
>10000-50000
>50000
NOTES:
* - DATA OBTAINED FROM JANUARY 2000 EVENT
" - DATA OBTAINED FROM MARCH 2001 EVENT
ND - NON-DETECT
200'
200'
HISTORIC TOTAL VOCs
NOVEMBER-DECEMBER 1999
PRIOR TO GWTP STARTUP
SHALLOW BEDROCK ZONE
SULLIVAN'S LEDGE SUPERFUND SITE
NEW BEDFORD. MASSACHUSETTS
SEPTEMBER 2022
FIGURE 11A
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
G-9
-------
"igure G-10: Total VOCs Concentrations PMP Event 1, October 2020, and PMP Event 6, August 2022 - Shallow Bedrock Wells
LEGEND
------ SHALLOW COLLECTION TRENCH
APPROXIMATE LOCATION OF THE
SLURRY WALL
PERFORMANCE MONITORING
SAMPLING LOCATION
PERFORMANCE MONITORING
SAMPLING LOCATION AND
POINTS OF EVALUATION (POE)
MONITORING WELL LOCATION
(NOT INCLUDED IN PMP PROGRAM)
® RECOVERY WELL LOCATION
(DATA NOT INCLUDED)
(3440) TOTAL VOCs CONCENTRATIONS (ugfL)
TOTAL VOCs CONCENTRATIONS Iuq/L)
ft <10
# >10-1000
9 >1000-5000
(J} >5000-10000
>10000-50000
>50000
PMP EVENT 1 NOTES:
' - DATA OBTAINED FIRST TIME SAMPLED
DURING PMP EVENT 2
" - DATA OBTAINED FIRST TIME SAMPLED
DURING PMP EVENT 4
NS-NOT SAMPLED
PMP EVENT 6 NOTES:
' - DATA OBTAINED FROM EVENT 5A (LOCATION
NOT SAMPLED IN PMP EVENT 6)
250 0 250
TOTAL VOCs CONCENTRATIONS
PMP EVENT 1 OCTOBER 2020
AND PMP EVENT 6 AUGUST 2022
SHALLOW BEDROCK ZONE
SULLIVAN'S LEDGE SUPERFUND SITE
NEW BEDFORD, MASSACHUSETTS
SEPTEMBER 2022
FIGURE 11B
PMP EVENT 1 OCTOBER 2020
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
G-10
-------
PZ.16II
(NS1 |
ECJ-2 ;1 IT] iS53£Drl
(15^1 (400,4)|
"igure G-ll: Historic Total VOCs Prior to GWTP Startup, November-December 1999
- Intermediate Bedrock Zone
LEGEND
SHALLOW COLLECTION TRENCH
APPROXIMATE LOCATION OF THE
SLURRY WALL
PERFORMANCE MONITORING
SAMPLING LOCATION
PERFORMANCE MONITORING
SAMPLING LOCATION AND
POINTS OF EVALUATION {POE}
-fy- MONITORING WELL LOCATION
(NOT INCLUDED IN PMP PROGRAM)
® RECOVERY WELL LOCATION
(DATA NOT INCLUDED)
(3440) TOTAL VOCs CONCENTRATIONS (ugrt.)
TOTAL VOCs CONCENTRATIONS (uoU
• <10
# >10-1000
0 >1000-5000
>5000-10000
>10000-50000
>50000
NOTES:
' - DATA OBTAINED FROM JANUARY 2000 EVENT NS
- NOT SAMPLED
FOR ECJ-2 WELL, THE HIGHEST VOC
CONCENTRATION WAS USED
HISTORIC TOTAL VOCs
NOVEMBER-DECEMBER 1999
PRIOR TO GWTP STARTUP
INTERMEDIATE BEDROCK ZONE
SULLIVAN'S LEDGE SUPERFUND SITE
NEW BEDFORD, MASSACHUSETTS
SEPTEMBER 2022
FIGURE 12A
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
G-ll
-------
PZ.16II
(NS1 |
ECJ-2 ;1 IT] iS53£Drl
(15^1 (400,4)|
"igure G-12: Historic Total VOCs Prior to GWTP Startup, November-December 1999 -
Intermediate Bedrock Zone
LEGEND
SHALLOW COLLECTION TRENCH
APPROXIMATE LOCATION OF THE
SLURRY WALL
PERFORMANCE MONITORING
SAMPLING LOCATION
PERFORMANCE MONITORING
SAMPLING LOCATION AND
POINTS OF EVALUATION {POE}
-fy- MONITORING WELL LOCATION
(NOT INCLUDED IN PMP PROGRAM)
® RECOVERY WELL LOCATION
(DATA NOT INCLUDED)
(3440) TOTAL VOCs CONCENTRATIONS (ugfl.)
TOTAL VOCs CONCENTRATIONS (uoU
• <10
# >10-1000
0 >1000-5000
>5000-10000
>10000-50000
>50000
NOTES:
' - DATA OBTAINED FROM JANUARY 2000 EVENT NS
- NOT SAMPLED
FOR ECJ-2 WELL, THE HIGHEST VOC
CONCENTRATION WAS USED
HISTORIC TOTAL VOCs
NOVEMBER-DECEMBER 1999
PRIOR TO GWTP STARTUP
INTERMEDIATE BEDROCK ZONE
SULLIVAN'S LEDGE SUPERFUND SITE
NEW BEDFORD, MASSACHUSETTS
SEPTEMBER 2022
FIGURE 12A
Source: Sullivan's Ledge Supeifund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
G-12
-------
"igure G-13: Total Concentrations PMP Event 1, October 2020, and PMP Event 6, August 2022 - Intermediate Bedrock Zone
LEGEND
SHALLOW COLLECTION TRENCH
APPROXIMATE LOCATION OF THE
SLURRY WALL
PERFORMANCE MONITORING
SAMPLING LOCATION
PERFORMANCE MONITORING
SAMPLING LOCATION AND
POINTS OF EVALUATION |POEj
MONITORING WELL LOCATION
(NOT INCLUDED IN PMP PROGRAM)
® RECOVERY WELL LOCATION
(DATA NOT INCLUDED)
(3440) TOTAL VOCs CONCENTRATIONS (ug.L)
TOTAL VOCs CONCENTRATIONS fuoJLi
• <10
0 >10-1000
Q >1000-5000
^ >5000-10000
>10000-50000
>50000
PMP EVENT 1 NOTES:
" - DATA OBTAINED FIRST TIME SAMPLED
DURING PMP EVENT 2
FOR ECJ-5 AND ECJ-2 WELLS. THE HIGHEST
CONCENTRATION WAS USED
PMP EVENT 6 NOTES.
FOR ECJ-5 AND ECJ-2 WELLS. THE HIGHEST
VOC CONCENTRATION WAS USED
250 0 250
TOTAL VOCs CONCENTRATIONS
PMP EVENT 1 OCTOBER 2020
AND PMP EVENT 6 AUGUST 2022
INTERMEDIATE BEDROCK ZONE
SULLIVAN'S LEDGE SUPERFUND SITE
NEW BEDFORD. MASSACHUSETTS
SEPTEMBER 2022
FIGURE 12B
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
G-13
-------
"igure G-14: Historic Total VOCs Prior to GWTP Startup, November-December 1999 - Deep Bedrock Zone
LEGEND
------ SHALLOW COLLECTION TRENCH
APPROXIMATE LOCATION OF THE
SLURRY WALL
PERFORMANCE MONFTORING
SAMPLING LOCATION
PERFORMANCE MONITORING
SAMPLING LOCATION AND
POINTS OF EVALUATION {POE}
MONITORING WELL LOCATION
(NOT INCLUDED IN PMP PROGRAM)
® RECOVERY WELL LOCATION
(DATA NOT INCLUDED)
(3440) TOTAL VOCs CONCENTRATIONS (utf LI
TOTAL VOCs CONCENTRATIONS 10-1000
9 > 1000-5000
£ >5000-10000
>10000-50000
>50000
NOTES:
NS - NOT SAMPLED
200'
200'
HISTORIC TOTAL VOCs
NOVEMBER-DECEMBER 1999
PRIOR TO GWTP STARTUP
DEEP BEDROCK ZONE
SULLIVAN'S LEDGE SUPERFUND SITE
NEW BEDFORD, MASSACHUSETTS
SEPTEMBER 2022
FIGURE 13A
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
G-14
-------
"igure G-15: Historic Total VOCs Prior to GWTP Startup, November-December 1999 - Deep Bedrock Zone
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
TOTAL VOCs CONCENTRATIONS
PMP EVENT 1 OCTOBER 2020
AND PMP EVENT 6 AUGUST 2022
DEEP BEDROCK ZONE
SULLIVAN'S LEDGE SUPERFUND SITE
NEW BEDFORD. MASSACHUSETTS
SEPTEMBER 2022
FIGURE 13B
LEGEND
------ SHALLOW COLLECTION TRENCH
APPROXI MATE LOCATION OF THE
SLURRY WALL
PERFORMANCE MONITORING
SAMPLING LOCATION
PERFORMANCE MONITORING
SAMPLING LOCATION AND
POINTS OF EVALUATION (POE)
MON ITORING WELL LOCATION
(NOT INCLUDED IN PMP PROGRAM)
® RECOVERY WELL LOCATION
(DATA NOT INCLUDED)
(3440) TOTAL VOCs CONCENTRATIONS (ug/L)
TOTAL VOCs CONCENTRATIONS (ual)
• <10
# >10-1000
0 >1000-5000
^ >6000-10000
jA >10000-50000
>50000
PMP EVENT 1 OCTOBER 2020
G-15
-------
figure G-16: Surface Water and Sediment Sampling Locations, 2019
FIGURE. 1
LEGEND
SURFACE W-
SAMPLE LOC
SULLIVAN'S LEDGE
SUPERFUND SIT
NEW BEDFORD, MA
SURFACE WATER/SEDIMENT
SAMPLE LOGATIONS
250
FILE NCt »W.e079J.02&
Jjsj| OBRIENBGERE
© Efngtnavi. he
Source: Sullivan's Ledge Superfund Site - September 2019 Biennial Surface Water and Sediment Monitoring Report, prepared by Ramboll. February 6, 2020.
G-16
-------
figure G-17: Landfill Gas Monitoring Locations
Source: Sullivan's Ledge Superfund Site - December 2022 Landfill Gas Monitoring Report, prepared by O-Brien & Gere Engineers, Inc. December 21, 2022.
G-17
-------
Figure G-18: OU1/OU2 Wetland Sampling Locations
Source: 2022 Environmental Monitoring Sampling and Results Report, Sullivan's Ledge Superfund Site, prepared by City of New Bedford. August 2022.
G-18
-------
APPENDIX H - DATA REVIEW TABLES
Table H-l: PMP Event 6, Groundwater Data Summary, VOCs
Table 1
Sullivan's Ledge Superfund Site
Performance Monitoring Plan Event S
Groundwater Data Summary
Volatile Organic Compounds1
Chemical Name
Number of Sample
Locations
Number of Locations with
Detects
Maximum Detected
Concentration (ug/l)
Location of Maximum
Concentration
Sample Zone of Maximum
Detection
1,1-Dichlonoethane
33
7
7.3
ECJ-1 (72)
Shallow Bedrock
1,1-Dichloroethene
33
20
327
ECJ-5-I4*
Deep Bedrock
1,2,4-T rich lorobenzene
33
2
5.8
ECJ-1 (72)
Shallow Bedrock
1,2,4-Tri methy Ibenzene
33
1
7.7
MW-22A
Overburden
1,2-Dichlonobenzene
33
8
28.3 3
GCA-1
Shallow Bedrock
1,2-Dichloroethane
33
6
4.9 3
ECJ-1 (72)
Shallow Bedrock
1,3,5-Trimethylbenzene
33
1
2.0
MW-22A
Overburden
1,3-Dichlorobenzene
33
12
223 J
OBG-1
Recovery Well
1,4-Dichlorobenzene
33
21
457
OBG-1
Recovery Well
Acetone
33
i
6.4 3
MW-22A
Overburden
Benzene
33
28
2810
MW-24
Shallow Bedrock
Chlorobenzene
33
19
795
MW-24
Shallow Bedrock
Chloroethane
33
5
7.0
PZ-17S*
Shallow Bedrock
cis-1,2-Dichloroethylene
33
27
101000
OBG-1
Recovery Well
Ethy Ibenzene
33
17
4470
OBG-1
Recovery Well
Isopropy Ibenzene
33
6
13.1
MW-24
Shallow Bedrock
M,P-Xylene
33
4
24.5
MW-22A
Overburden
Naphthalene
33
1
91
MW-22A
Overburden
n-Butylbenzene
33
1
1.9 3
MW-12AR
Overburden
n-Propylben zene
33
5
8.7 J
MW-24
Shallow Bedrock
O-Xylene
33
4
11.7
MW-22A
Overburden
sec-Butyl benzene
33
2
1.3 3
MW-12AR
Overburden
Toluene
33
20
3200
OBG-1
Recovery Well
trans-1,2-Dich loroethene
33
18
91.4 J
BEI-1
Recovery Well
Trich lo roethylene
33
14
940
MW-4
Shallow Bedrock
Vinyl Chloride
33
26
28900
OBG-1
Recovery Well
Notes:
1. VOCs analyzed using method 8260C. Only detected compounds shown
2. J = Estimated value
3. * = Point of Evaluation
4. Recovery welts are non operational
Source: Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ramboll.
H-l
-------
Table H-2: PMP Event 6, Groundwater Data Summary, PCBs
Table 2
Sullivan's Ledge Superfund Site
Performance Monitoring Plan Event 6
Groundwater Data Summary
PCBs1
Chemical Name
Number of Sample
Number of Locations
Maximum Detected
Location of Maximum
Sample Zone of
Maximum
Detection
Locations
with Detects
Concentration (ug/l)
Concentration
Unfiltered
Arodor 1254
32
6
192
ECJ-1 (267)
Deep Bedrock
Arodor 1242
32
5
13,7 J+
DUP OBG-1
ftecovei'y Well
Arodor 1248
32
3
5.9
ECJ-1 (72)
Shallow Bedrock
Arodor 1221
32
1
159
MW-24
Shallow Bedrock
Field filtered
Arodor 1221
10
1
20.2
MW-24-F
Shallow Bedrock
Arodor 1254
10
1
1.8
ECJ-1 (267)-F
Deep Bedrock
Arodor 1242
10
1
0.28
BEI-l-F
Reoovei'y Well
Notes:
1. PCB compounds analyzed using method 8082A. Only detected compounds shown
2. Sample port depths are shown in ( ) for ECJ-1 Westbay well
3. PCB Arodors exhibiting an altered pattern were identified by the laboratory to represent the closest match
4. F= Field-filtered sample, J = Estimated (+) Biased high
5. Recovery wells are non operational
H-2
-------
Table H-3: Surface Water Data Summary, 2019
Table 1
Sullivan s Ledge SuperFund 5rte
2019 Biennial Monitoring Event
Surface Water Data Summary
Metals Compounds
Constituent
Number of Sample
Locations
Number of Detects
Maximum Detected
Concentration (mg/3)
inSW-1. 5W-2 and 5W-4
Location of High
Concentration
Calcium
6
6
16.3D
SW-2
Iron
6
<5
2.72
SW-2
Manganese
6
6
~.410
SW-2-F1
Sodiun
6
6
150
SW-2
Zinc
6
5
~.~253
SW-2
Nates:
1. Detected in the Fed duplicate oF SW-4 at 0.413 rng.'L.
2. Only detected compounds shown.
3. Field-filtered and unaltered san-ples wcs obtained from each oF the three sample locations.
M33SSJO
Table 2
Sullivan's Ledge Superfund Site
2019 Biennial Monitoring Event
Surface Water Data Summary
PAHs Compounds
Constituent
Number of Sample
Number of Detects
Maximum Detected
Location of High
Locations
Concentration (ug/T)
in SW-1, SW-2 and SW-4
Concentration
Acenaphthene
3
1
0 0328 J
FDSW-4
Notes:
1. Only detected compounds shown.
2. J - Estimated value
Source: Sullivan's Ledge Superfund Site - September 2019 Biennial Surface Water and Sediment Monitoring Report, prepared by Ramboll. February 6, 2020.
H-3
-------
Table H-4: Sediment Data Summary, 2019
Table 3
Sullivan's Ledge Superfund Site
2019 Biennial Monitoring Event
Sediment Data Summary
PAHs
Constituent
Number of
Number of
Maximum Detected
Location of
Sample Locations
Detects
Concentration (ug/kg)
High
in SD-1 through SD-5
Concentration
2-Methy (naphthalene
5
Acenaphthene
5
Acenaphthylene
5
Anthracene
5
Benzo[a)anthracene
5
Benzo[a]pyrene
5
Benzo [b]f I uoranthene
5
Benzo [g, h, i J peryI one
5
Benzo[k]fluoranthene
5
Chryserce
5
Dibenzo [a, h] Anthracene
5
Fl uoranthene
5
Fluorene
5
lndeno[1,2,3-cd]pyrene
5
Naphthalene
5
Phenanthrgne
5
Pyrene
5
Notes:
1. J - Estimated value
4
21.1
SD-2
5
84.7
SD-2
5
33.3
SD-2
5
237
SD-2
5
895
SD-2
5
1070
SD-2
5
1650
SD-2
5
825
SD-2
5
600
SD-2
5
1310
SD-2
5
241 J
SD-2
5
2700
SD-2
5
104
SD-2
5
946
SD-2
5
4S.4
SD-2
5
1380
SD-2
5
1910
SD-2
H-4
-------
Table 4
Sullivan's Ledge Superfund Site
2019 Biennial Monitoring Event
Sediment Data Summary
PCBs
Constituent
Number of Sample
Number of Detects
Maximum Detected
Location of
Locations
Concentration (mg/kg)
High
in SD-1 through SD-5
Concentration
Aroclor 1248 5 1 0.112 J FDSED-1
Aroclor 1254 5 2 0.124 FDSED-1
Notes:
1. Only detected compounds shown
2 . J - Estimated value
H-5
-------
Table 5
Sullivan's Ledge Superfund Site
2019 Biennial Monitoring Event
Sediment Data Summary
Metals
Constituent
Number of Sample
Locations
Number of Detects
Maximum Detected
Concentration (mg/kg)
in SD-1 through SD-5
Location of
High
Concentration
Aluminum
5
5
12400 J
SD-3
Arsenic
5
3
12.1 J
SD-3
Barium
5
4
127 J
SD-3
Berylium
5
1
0.4
SD-2
Calcium
5
5
3630 J
SD-3
Chromium
5
5
51.3
SD-5
Copper
5
5
57.1
SD-5
Iron
5
5
49100 J
SD-3
Lead
5
5
120 J
SD-53
Magnesium
5
5
4000 J
SD-3
Manganese
5
5
967
SD-4
Mercury
5
1
0.052
SD-2
Nickel
5
5
17.3 J
SD-3
Vanadium
5
5
28.5
SD-5
Zinc
5
5
313
SD-5
Notes:
1. J - Estimated value
2. Only detected compounds shown
3. Constituent detected at higher concentration [148 J mg/kg) in the duplicate sample for SD-1
Table 6
Sullivan's Ledge Superfund Site
2019 Biennial Monitoring Event
Sediment Data Summary
Total Organic Carbon
Constituent
SD-1
FDSD-1
SD-2
SD-3
SD-4
SD-5
TOC (%)
3.94
4.44
5.34
8.91
1.7
7.65
ug PCBs/g Carbon
1.07
5.3
1.1 U
1.3 UJ
5.49
0.6 U
Notes:
1. For samples SD-2, SD-3 and SD-5 where PCBs were classified as *U" and "UJ", the detection limits were utilized for
the PCB concentrations
Source: Sullivan's Ledge Superfund Site - September 2019 Biennial Surface Water and Sediment Monitoring Report, prepared by RambolL February 6, 2020.
H-6
-------
Table H-5: OU2 Surface Water and Sediment Sampling Results, 2021
location
Coordinate;'
Sample ID
Date
sample Mattix
TOC (cc)
TOC (ppm)
£k Mean
TOC
Temp. (-CI
pH at
cc Solids
Total PCBs
jppral
Total PCBs
jppb)
ng Pte/g
or-
Lattitude
longitude
5W3Cl/SDpCl
41.65676917
-7a?55S?.S3
SWF CI
10,'6/2:21
Surface Water
...
...
...
16.8
6.53
<¦ 0,0001
• 0.10C
_
S~'L'la
10/6/2021
$e<3(>-n-=nt
.-:v
I33C0
--
65,3
0 146
146
—
tDPClb
10/6/2021
. 51
_ r 2 ;
3700
_
65.1
C.223
22*-"
...
SDPClc
10/6/2C21
lJt
1760 C
7300
_
52,4
0,0381
So, 1
2,16
;r^aa
10/6/2C21
5.5S
5 5 SOC
-30900
—
45.3
0,0397
3S.7
—
SWPC2/SOPC2
41.65770225
-70.95607767
5WPC2
10/6/2021
Surface 'Aater
16,5
6,73
< 0,0001
- 0,100
...
S:>PC2a
10/6/2021
Seri-r.snt
2,02
2020C
12075
—
70,5
* 0,0234
« 23.4
_
SDPClb
10/6/2021
3,57
3 3702
-1425
_
fri.O
0,0430
43,0
^,23
5PFC1:
10/6/2021
2,12
20200
12075
__
73.0
'¦ 0,0232
- 23,2
...
S:,=C2o
10/6/2021
5.5
55000
-22725
—
43,3
0.0421
42,1
—
5W-C5 'SI ->*5
-1 655.5143
-70 .356:1-4
iWPCS
10/6/2321
Surface Water
_
...
...
16,3
6.£5
• 0.0001
¦ 0.100
SWFC3 DUP
10/6/2021
...
__
16.?
6.S5
< C.0G01
- 0.1C0
5DPC3a
10/6/2021
Segment
2.46
24600
8960
—-
65,2
O.OS'96
SS-,6
2,67
52 = C;s DiP
10/6/2021
2,20
2200C
11560
—
65.5
0,0544
54.4
...
5DPC3b
10/6/2021
5.53
56300
-22740
—
51.7
• 0,0347
- 34.7
...
5DF-C5;
10/6/2021
l.?l
IS'lOG
14460
_
71,2
0.li294
25,4
_
;;>oc3 3
10/6/2021
4,58
45.300
-12240
...
51,3
0,0310
31,0
—
;w-c4/sr'?c4
41 66026472
-73.95565056
SWPC4
10/6/2021
Surface Water
_
...
16,4
7,13
* 0.0001
< 0.10C
...
SDPC4a
10/6/2021
Sen Tent
2,53
26300
2275
...
60,3
• 0.025,3
v 0,022,3
¦ C.0236
• C.025S
25.3
0.S0
5DP24b
10/6/2021
2,35
2 3 f 0 C
5075
—
67,3
•' 22,0
—
5DFC4;
10/6/2021
2.52
2620C
2375
...
6S.1
- 23,5
—
.OPC4;
10/6/2021
3,33
33300
-9725
_
61,1
• 25. S
_
OU2-ad/.vet
41 65?45S2£
-70 25555421
SOIlPC*
10/6/2021
Wetland Soil
3, S3
3330C
—
_
61.7
- 0,0250
« 25.0
0.65
OU2-ad.wet
41 65765403
-70 95547222
C-oi!PC2
10/6/2C21
1,3?
19900
—
--
69,4
• C.0222
^ 22,2
1.12
OU2-V W 1
41 55599591
-70?53i4217
iO'lFCe
10/6/2021
5.54
53400
_
45,3
•• C.03S'7
- 3?,7
0.72
OU2-V Mi 2
41 55?3?3Q5
-70 95695353
Goi'F C5
10/6/2021
J.77
37700
...
_
61,2
C.02,370
2S.7
0.75
OU2-V K' 3
41 =5560523
-70 95SC2273
5orFC5
10/6/2021
1C.1
101000
_
_
31,3
-- 0.0552
' 55,2
0,55
OU2-V M 4
41 659S2423
-70 55SC1C35
?0'iFC4
10/6/2:21
4,71
47100
...
47,0
- 0,0410
« 41.0
0.37
- «e>u.t j.'a: fcun3 be tisn tins Psoot.ng Le#-s > RL| a<- Cr3c*.ica< Cuant tatiDn Le.ei by tfe 3DC rater,
— Sample r.ot aii ,:¦$$ for tiu tm /sis
• A: S«ccEPi curM2 Z013 ^arp'.ng Event
*' calcu'Sted u:.ngfcFiBi n Ml'^go^'dedbi To: ,r.mg'fgaiomuhsc sect b% 3 10CC mg. gorv.ers on 'actor if PCBs »ver#
-------
Table H-6: PFAS Results in Groundwater, March 2023
Location
Units
EPA
RSL
HQ
= 0.1
MMCL
GCA-1
MW-6
MW-6A
MW-
12AR
MW-24
PZ^ll
PZ-15A
PZ-17S
Sample Type
N
N
FD
N
N
N
N
N
N
Per- and Polyfluoroalkyl Substances (PFAS)
Perfluorobutanesulfonic
acid (PFBS)
ng/L
600
--
2
UJ
2
U
2
U
1.9
U
2.4
2.6
2
U
2.5
2 U
Perfluorobutanoic Acid
(PFBA)
ng/L
1,800
--
12
9.1
8
17
J
5.8
4
U
18
J
5.3
J
7.3
Perfluorodecanoic Acid
(PFDA)
ng/L
--
~
2
UJ
2
u
2
U
1.9
u
2
U
2
U
2
u
2
U
2 U
Perfluoroheptanoic acid
(PFHpA)
ng/L
~
--
2
2
u
2
u
1.9
u
2.1
2
2
u
3.31
2 U
Perfluorohexanesulfonic
acid (PFHxS)
ng/L
40
~
2
u
2
u
2
u
1.9
u
2.2
2
u
2
u
2
U
2.2
Perfluorohexanoic Acid
(PFHxA)
ng/L
990
—
2.3
J
2
UJ
2
u
2.2
J
3.3
J
2.8
2
u
5.1
J
2.5 J
Perfluorononanoic acid
(PFNA)
ng/L
6
—
2
UJ
2
UJ
2
u
1.9
u
2
u
2
u
2
u
2
u
2 U
Perfluorooctanesulfonic
acid (PFOS)
ng/L
4
—
3.9
J
10
8.8
7.9
5.9
4
5.8
7.8
3.7
Perfluorooctanoic acid
(PFOA)
ng/L
6
--
29
J
11
10
13
21
15
14
16.8
22
Perfluoropentanoic Acid
ng/L
-
~
2.2
2
u
2
u
1.9
UJ
2.6
2.2
2
UJ
4.7
J
2 U
Total PFAS for MassDEP3
-
20
34.9
21
18.8
20.9
31.2
21
19.8
27.9
27.9
Notes:
a) *MassDEP MCL for PFAS based on sum of PFHxS, PFHpA, PFOA, PFOS, PFNA and PFDA. Only detected analytes included in total.
N = normal
FD = field duplicate
J = estimated
U = undetected at the reporting limit
Blue cell = exceeds RSL
Orange cell = exceeds MMCL
H-8
-------
Table H-7: Landfill Gas Monitoring Results, December 2022
Wi-ti
Locati-an"'
, 50-55'F
CMltfU-rtw.
n:twsu--c
tfit .Sfsstem
*.jr4Tuc iEM
SOO©'~ Ser.-ai
Kumfrflf
JOOC-
PIQ Serial
KumU-i."'
teW:!;* LSI)1
01 rDon >cfc. •: *.. >
MyO'Hjer. SuI?MS<* (p
582-92727'
mss-
ta'WC ~ Inc&s waterastern LEI - Lower Explosive Unit HA-Not AvaBable inHg - inches Of Kerairy ppm- parts per million VOCs - VolMile Organic Compounds PW - Pulled Water from vapor port
1- Wets numbered seQuenHamy from southwe-st comer M dtsjxss? area. Weils GM-1R through GM-B are along western oounn Detector with a 0.45-micron external rstter.
-1 tg water tram the port duilng purging (after 3 minutes at SM-18, after 9 minutes at GM-20, and after appro*. 3D seconds at GM-19). The instrument fan was stepped before water reached the titer. Post-purge readings were recorded at GM-18 an-d GM-20. Pre/post-purge
datGM-19.
r 475-3-FM-BK »
* and recorded to a tenth of a unit.
9- 25% La alter! on per MassDEP Solid Waste Manaoement WnW&mvM Hoitftortnfl fteqtiiramcais 3iQ cm 19.132(5)^},
Source: Sullivan's Ledge Superfund Site - December 2022 Landfill Gas Monitoring, dated December 2022. Prepared by Ramboll.
H-9
-------
APPENDIX I - DATA TREND GRAPHS
All trend graphs are from Sullivan's Ledge Superfund Site PMP Event 6 Report, dated December 2022. Prepared by Ram boll.
Graph 1-1: Total VOCs Overburden Groundwater, PMP Events 1-6
Total VOCs
1 nnnn
Overburden Groundwater
J.UUUU
MW-6A (quarterly)
• Detect
A Non detect
MW-22A (quarterly)
• Detect
A Non detect
1000 i
PZ-1Q (semiannual)
• Detect
A Non detect
PZ-12 (semiannual)
• Detect
%
A Non detect
3
wt
MW-10AR (semiannual!
C
y" •
O
Ti 100
• Detect
<9
im.
• ¦
A Non detect
a
MW-12AR (semiannual)
o
u
• Detect
A Non detect
MW-13A (annual)
• Detect
10
A Non detect
PMP Event 1 Baseline
1 I
Points of Evaluation in bold
10/6/2020 1/14/2021 4/24/2021 8/2/2021 11/10/2021 2/18/2022 5/29/2022 9/6/2022
Date
1-1
-------
Graph 1-2: Total VOCs Shallow Bedrock Groundwater, PMP Events 1-6
Total VOCs
Shallow Bedrock Groundwater
10000
1000
is
3
c
0
u
1
B
o
100
10
0.1
10/6/2020
MW-6 (ciuarterlvl
Detect
Non detect
PZ-16S Isenii-annuall
•
Detect
4
Non detect
PZ-17S (semi-annua 1)
•
Detect
A
Non detect
• EO-2 (47) (ciuarterlv)
•
Detect
A
Non detect
ECJ-5-11 (quarterly)
•
Detect
A
Non detect
MW-2 (annually)
•
Detect
A
Non detect
GCA-1 (quarterly)
•
Detect
A
Non detect
MW-17 (semi-annual)
•
Detect
A
Non detect
ECJ-1 (72) (quarterly)
•
Detect
A
Non detect
MW-24 (annually)
•
Detect
A
Non detect
«^^PMP Event 1 Baseline
1/14/2021
4/24/2021
8/2/2021 11/10/2021
Date
2/18/2022 5/29/2022 9/6/2022
Points of Evaluation in bold
1-2
-------
Graph 1-3: Total VOCs Intermediate Bedrock Groundwater, PMP Events 1-6
PZ-161 (semiannual)
•
Detect
A
Non detect
PZ-171 (semiannual)
•
Detect
A
Non detect
ECJ-2 (117) (auarterlv)
•
Detect
A
Non detect
ECJ-2 (152) (quarterly)
•
Detect
A
Non detect
ECJ-5-12 (auarterlv)
•
Detect
A
Non detect
ECJ-5-13 (auarterlv)
•
Detect
A
Non detect
PMP Event 1 Baseline
Points of evaluation in bold
100000
10000
1000
Total VOCs
Intermediate Bedrock Groundwater
100 L
10/6/2020 1/14/2021 4/24/2021 8/2/2021 11/10/2021 2/18/2022 5/29/2022 9/6/2022
Date
1-3
-------
Graph 1-4: Total VOCs Deep Bedrock Groundwater, PMP Events 1-6
Total VOCs
Deep Bedrock Groundwater
100000
10000
c
o
1000
100
9/26/2020
1/4/2021
4/14/2021
7/23/2021 10/31/2021
Date
2/8/2022
1-4
PZ-16D (quarterly}
•
Detect
A
Non detect
PZ-17D (quarterly!
•
Detect
A
Non detect
ECJ-2 11871 (quarterly!
•
Detect
A
Non detect
ECJ-5-14 (quarterly)
•
Detect
A
Non detect
ECJ-1 (267) (quarterly)
¦
Detect
A
Non detect
PMP Event 1 Baseline
Points of Evaluatin in bold
5/19/2022
8/27/2022
-------
Graph 1-5: Total PCBs Overburden Groundwater, PMP Events 1-6
Total PCBs
Overburden Groundwater
Date
1-5
-------
Graph 1-6: Total PCBs Shallow Bedrock Groundwater, PMP Events 1-6
o
9/26/2020
Total PCBs
Shallow Bedrock Groundwater
ECJ-21471 (auarterlvt
•
Detect
A
Non detect/zero
— GCA-1 (quarterly)
•
Detect
A
Non detect/zero
— ECJ-1 (72) (quarterly)
•
Detect
A
Non detect/zero
- -
-ECJ-1 (72) -F (quarterly)
O
Detect
A
Non detect
— MW-24 (Annual)
•
Detect
A
Non detect
- MW-24 - F (Annual)
o
Detect
A
Non detect
— Baseline Event 1
Points of Evaluation in bold
Note - ECJ-1 (72) was field
fiitered on 1/12/2021 and
MW-24 was field fiitered on
7/15/2021 and Sf2/2022.
Dashed line and/or open
symbol shows filtered sample
data.
1/4/2021 4/14/2021 7/23/2021 10/31/2021
Date
2/8/2022
5/19/2022
8/27/2022
1-6
-------
Graph 1-7: Total PCBs Intermediate Bedrock Groundwater, PMP Events 1-6
Total PCBs
Intermediate Bedrock Groundwater
I
ECJ-2 (117) (quarterly)
Detect
Nort detect
ECJ-2 (152) [quarterly)
• Detect
A Non detect
Baseline Event 1
Points of Evaluation in bold
9/26/2020 1/4/2021 4/14/2021 7/23/2021 10/31/2021
Date
2/8/2022
5/19/2022
8/27/2022
1-7
-------
Graph 1-8: Total PCBs Intermediate Bedrock Groundwater, PMP Events 1-6
Total PCBs
Deep Bedrock Groundwater
1200
1000
800
"3
3
c
£ 600
c
o
u
400
200
0 S—
9/26/2020
Ff I-? Innai+erlul
Detect
Non detect/zero
.
ECJ-5-14 Iciuarterlvl
•
Detect
A
Non detect
- EG-1 (267}-F (quarterly)
O
Detect
A
Non detect
— EG-1 (267) (quarterly)
W
Detect
A
Non detect
— Baseline Event 1
Points of Evaluation in bold
Note - ECJ-1 (267) - Each
sample was field filtered.
Dashed line and open
symbols show filtered
sample data
1/4/2021 4/14/2021 7/23/2021 10/31/2021
Date
2/S/2022
5/19/2022
8/27/2022
1-8
-------
APPENDIX J - SITE INSPECTION CHECKLIST
FIVE-YEAR REVIEW SITE INSPECTION CHECKLIST
I. SITE INFORMATION
Site Name: Sullivan's Ledge
Date of Inspection: 03/22/2023
Location and Region: New Bedford. MA; Region 1
EPA ID: MAD980731343
Agency, Office or Company Leading the FYR: EPA
Region 1
Weather/Temperature: Sunny, approx. 50 degrees F
~ Monitored natural attenuation
~ Groundwater containment
Vertical barrier walls (slurry wall) (OU1)
Remedy Includes: (Check all that apply)
Landfill cover/containment (OU1)
Access controls (OU1)
E3 Institutional controls (OU 1. OU2)
Groundwater pump and treatment (OU 1)
~ Surface water collection and treatment
Other: construction of a culvert and construction of a passive underdrain collection system (OU 1).
^
Attachments:
Inspection team roster attached
~ Site map attached
II. INTERVIEWS (check all that apply)
1. O&M Site Manager
Name
Title
Date
Interviewed ~ at site ~ at office ~ by phone.
Problems, suggestions ~ Report attached:
2. O&M Staff
Name
Title
Date
Interviewed ~ at site ~ at office ~ by phone.
Problems/suggestions ~ Report attached:
3. Local Regulatory Authorities and Response Agencies (i.e., state and tribal offices, emergency
response office, police department, office of public health or environmental health, zoning office,
recorder of deeds, or other city and county offices). Fill in all that apply.
Agency City of New Bedford. Dept. of Public Infrastructure
Contact Jim Costa Superintendent
Name of Wastewater Date
Title
Problems/suggestions ~ Report attached:
Phone No.
Agency
Contact Name
Problems/suggestions ~ Report attached:.
Title
Date
Phone No.
Agency
Contact
Name Title
Problems/suggestions ~ Report attached:
Date
Phone No.
Agency
Contact
Name Title
Problems/suggestions ~ Report attached:
Date
Phone No.
J-l
-------
Agency
Contact
Name Title
Problems/suggestions [~~| Report attached:
Date
Phone No.
4.
Other Interviews (optional) HI Report attached:
III. ON-SITE DOCUMENTS AND RECORDS VERIFIED (check all that apply)
1.
O&M Documents
O&M manual £3 Readily available
~ Up to date
~ N/A
E3 As-built drawings [3 Readily available
~ Up to date
~ N/A
E3 Maintenance logs ^ Readily available
[X] Up to date
~ N/A
Remarks: Once the groundwater system is running again, an O&M manual update is expected.
2.
Site-Specific Health and Safety Plan
~ Readily available
~ Up to date
0N/A
~ Contingency plan/emergency response plan
~ Readily available
~ Up to date
0N/A
Remarks:
3.
O&M and OS HA Training Records
E3 Readily available
~ Up to date
~ n/a
Remarks: The Citv and all contractors maintain their own OSH A training records.
4.
Permits and Service Agreements
~ Air discharge permit
~ Readily available
~ Up to date
~ n/a
~ Effluent discharge
~ Readily available
~ Up to date
~ n/a
IX] Waste disposal. POTW
~ Readily available
~ Up to date
~ n/a
n Other Dcrmits:
~ Readily available
~ Up to date
~ n/a
Remarks: When the groundwater treatment system is oDerating, the effluent is subject to the Citv of
New Bedford's discharge rcciuircments (permit #L-026A).
5.
Gas Generation Records
E3 Readily available
^ Up to date
~ n/a
Remarks: Monitoring of blower stack for the landfill gas extraction system
6.
Settlement Monument Records
Remarks:
~ Readily available
~ Up to date
0N/A
7.
Groundwater Monitoring Records
Remarks:
E3 Readily available
Up to date
~ n/a
8.
Leachate Extraction Records
~ Readily available
~ Up to date
Hn/a
Remarks:
9.
Discharge Compliance Records
~ Air ~ Readily available
~ Up to date
~ n/a
E3 Water (effluent) ~ Readily available
~ Up to date
~ n/a
Remarks: Sampling is onlv conducted when the system is in operation.
J-2
-------
10. Daily Access/Security Logs
E3 Readily available ~ Up to date [H N/A
Remarks:
IV. O&M COSTS
1. O&M Organization
l~l State in-house
O Contractor for state
IXI PRP in-house
IXI Contractor for PRP
l~l Federal facility in-house
~ Contractor for Federal facility
~
2. O&M Cost Records
153 Readily available
O Up to date
153 Funding mechanism/agreement in place
Q Unavailable
Original O&M cost estimate: HI Breakdown attached
Total annual cost by year for review period if available
Costs provided by the PMC for OU1; they do not include costs associated with GWTP O&M undertaken
by the City, which arc provided separately below.
From: 01/01/2018 To: 12/31/2018 $566,518 |~1 Breakdown attached
Date
Date
Total cost
From: 01/01/2019
To: 12/31/2019
$373,090
O Breakdown attached
Date
Date
Total cost
From: 01/01/2020
To: 12/31/2020
$327,598
O Breakdown attached
Date
Date
Total cost
From: 01/01/2021
To: 12/31/2021
$315,240
O Breakdown attached
Date
Date
Total cost
From: 01/01/2022
To: 12/31/2022
$529,869
O Breakdown attached
Date
Date
Total cost
Cost provided by the City for the operation of the GWTP:
From: 01/01/2018
To: 12/31/2018
$17,750
O Breakdown attached
Date
Date
Total cost
From: 01/01/2019
To: 12/31/2019
$93,513.43
O Breakdown attached
Date
Date
Total cost
From: 01/01/2020
To: 12/31/2020
$69,492.74
O Breakdown attached
Date
Date
Total cost
From: 01/01/2021
To: 12/31/2021
$35,743.97
O Breakdown attached
Date
Date
Total cost
From: 01/01/2022
To: 12/31/2022
$32,466.98
O Breakdown attached
Date
Date
Total cost
J-3
-------
3. Unanticipated or Unusually High O&M Costs during Review Period
Describe costs and reasons:
V. ACCESS AND INSTITUTIONAL CONTROLS [X] Applicable ~ N/A
A. Fencing
1. Fencing Damaged ~ Location shown on site map Gates secured ~ N/A
Remarks: A section of fence along Hathaway Road appeared to have a temporary repair. Damage had
occurred from an automobile. A permanent repair is expected soon.
B. Other Access Restrictions
1. Signs and Other Security Measures ~ Location shown on site map
Remarks: Signs are located on the outside of the landfill's perimeter fence.
C. Institutional Controls (ICs)
~ N/A
1.
Implementation and Enforcement
Site conditions imply ICs not properly implemented
Site conditions imply ICs not being fully enforced
Type of monitoring (e.g., self-reporting, drive by): self-reporting
Frequency:
Responsible party/agency: City of New Bedford
Contact Jim Costa
~ Yes |EI No ~ N/A
~ Yes M No ~ N/A
i costa
-------
Remarks:
B.
Other Site Conditions
Remarks:
VII. LANDFILL COVERS Applicable
~ N/A
A.
Landfill Surface
1.
Settlement (low spots)
~ Location shown on site map
E3 Settlement not evident
Area extent:
Depth:
Remarks:
2.
Cracks
l~l Location shown on site map
Cracking not evident
Lengths:
Widths:
Depths:
Remarks:
3.
Erosion
l~l Location shown on site map
Erosion not evident
Area extent:
Depth:
Remarks:
4.
Holes
~ Location shown on site map
~ Holes not evident
Area extent:
Depth:
Remarks: Possible burrowing animal hole observed on the northern landfill slope near the roadwav.
Also, several holes were observed near the base of one of the solar panels.
5.
Vegetative Cover
53 Grass
Cover properly established
l~l No signs of stress
l~l Trees/shrubs (indicate size and locations on a diagram)
Remarks:
6.
Alternative Cover (e.g
, armored rock, concrete)
Kl n/a
Remarks:
7.
Bulges
~ Location shown on site map
Bulges not evident
Area extent:
Height:
Remarks:
8.
Wet Areas/Water Damage ^ Wet areas/water damage not evident
l~l Wet areas
O Location shown on site map
Area extent:
l~l Ponding
O Location shown on site map
Area extent:
l~l Seeps
O Location shown on site map
Area extent:
[~l Soft subgrade
O Location shown on site map
Area extent:
Remarks:
9.
Slope Instability
O Slides
~ Location shown on site map
No evidence of slope instability
Area extent:
Remarks:
J-5
-------
B.
Benches ~ Applicable ^ N/A
(Horizontally constructed mounds of earth placed across a steep landfill side slope to interrupt the slope in
order to slow down the velocity of surface runoff and intercept and convey the runoff to a lined channel.)
C.
Letdown Channels ~ Applicable ^ N/A
(Channel lined with erosion control mats, riprap, grout bags or gabions that descend down the steep side
slope of the cover and will allow the runoff water collected by the benches to move oil of the landfill
cover without creating erosion gullies.)
D.
Cover Penetrations ^ Applicable ~ N/A
1
Gas Vents Q Active Q Passive
l~l Properly secured/locked Q Functioning O Routinely sampled
^ Good condition
l~l Evidence of leakage at penetration Q Needs maintenance
~ n/a
Remarks: The vents were canoed oreviouslv due to implementation of the active gas collection
svstem.
2
Gas Monitoring Probes
l~l Properly secured/locked Functioning ^ Routinely sampled
E3 Good condition
l~l Evidence of leakage at penetration O Needs maintenance
~ n/a
Remarks:
3
Monitoring Wells (within surface area of landfill)
53 Properly secured/locked [3 Functioning Routinely sampled
O Good condition
[~l Evidence of leakage at penetration O Needs maintenance
~ n/a
Remarks:
4
Extraction Wells Leachate
[~l Properly secured/locked O Functioning ~ Routinely sampled
O Good condition
l~l Evidence of leakage at penetration O Needs maintenance
Ex] n/a
Remarks:
5
Settlement Monuments Q Located O Routinely surveyed
Remarks:
13 N/a
E.
Gas Collection and Treatment Applicable ~ N/A
1
Gas Treatment Facilities
l~l Flaring O Thermal destruction
O Collection for reuse
K Good condition O Needs maintenance
Remarks: Active landfill gas extraction/blower svstem in place and operating.
2
Gas Collection Wells, Manifolds and Piping
[~l Good condition ~ Needs maintenance
Remarks: Most of the Dining is underground.
3
Gas Monitoring Facilities (e.g., gas monitoring of adjacent homes or buildings)
[~l Good condition ~ Needs maintenance ~ N/A
Remarks:
J-6
-------
F. Cover Drainage Layer £3 Applicable ~ N/A
1. Outlet Pipes Inspected ~ Functioning
~ n/a
Remarks:
2. Outlet Rock Inspected ~ Functioning
~ n/a
Remarks:
G. Detention/Sedimentation Ponds ~ Applicable
El n/a
EL Retaining Walls ~ Applicable ^ N/A
I. Perimeter Ditches/Off-Site Discharge [3 Applicable
~ n/a
1. Siltation ~ Location shown on site map
n Siltation not evident
Area extent:
Depth:
Remarks:
2. Vegetative Growth ~ Location shown on site map
~ n/a
E3 Vegetation does not impede flow
Area extent:
Tvpe:
Remarks:
3. Erosion ~ Location shown on site map
E3 Erosion not evident
Area extent:
Depth:
Remarks:
4. Discharge Structure £3 Functioning
~ n/a
Remarks:
VIII. VERTICAL BARRIER WALLS (slum wall) g] Applicable ~ N/A
1. Settlement ~ Location shown on site map
E3 Settlement not evident
Area extent:
Depth:
Remarks:
2. Performance Monitoring Tvpe of monitoring:
E3 Performance not monitored
Freciuencv:
~ Evidence of breaching
Head differential:
Remarks:
IX. GROUNDWATER/SURFACE WATER REMEDIES [g| Applicable * ~ N/A
*The groundwater treatment system was not in operation at the time of the inspection. It was expected to be
restarted May 1, 2023.
A. Groundwater Extraction Wells, Pumps and Pipelines
M Applicable ~ N/A
1. Pumps, Wellhead Plumbing and Electrical
~ Good condition ~ All required wells properly operating ~ Needs maintenance £3 N/A
Remarks: Not operating at time of inspection.
2. Extraction System Pipelines, Valves, Valve Boxes and Other Appurtenances
J-7
-------
~ Good condition [3 Needs maintenance
Remarks: The Citv recently replaced the wiring and hoses for the extraction wells in anticipation of the
svstem restart. Some of the extraction well boxes were in poor condition. The Citv noted thev mav be
replaced as funds allow.
3.
Spare Parts and Equipment
5<1 Readily available Q Good condition ~ Requires upgrade Q Needs to be provided
Remarks: The Citv of New Bedford was in the process of preparing the system for a restart.
B. Surface Water Collection Structures, Pumps and Pipelines ~ Applicable ^ N/A
C.
Treatnient System Applicable ~ N/A
1.
Treatnient Train (check components that apply)
l~l Metals removal Q Oil/water separation Q Biore mediation
~ Air stripping O Carbon adsorbers
l~l Filters:
n Additive (e.g.. chelation agent, flocculent):
n Others:
l~l Good condition Q Needs maintenance
l~l Sampling ports properly marked and functional
l~l Sampling/maintenance log displayed and up to date
l~l Equipment properly identified
n Quantity of groundwater treated annuallv:
n Quantity of surface water treated annuallv:
Remarks: Not currently in operation.
2.
Electrical Enclosures and Panels (properly rated and functional)
l~l N/A ~ Good condition O Needs maintenance
Remarks: Did not observe.
3.
Tanks, Vaults, Storage Vessels
l~l N/A [3 Good condition O Proper secondary containment O Needs maintenance
Remarks:
4.
Discharge Structure and Appurtenances
E3 N/A O Good condition O Needs maintenance
Remarks:
5.
Treatnient Building)*)
l~l N/A Good condition (esp. roof and doorways) O Needs repair
E3 Chemicals and equipment properly stored
Remarks:
6.
Monitoring Wells (pump and treatment remedy)
l~l Properly secured/locked [3 Functioning Routinely sampled O Good condition
J-8
-------
~ All required wells located ~ Needs maintenance ~ n/a
Remarks: Monitoring well MW-8 in the OU2 area was not property secured. Some erosion was also
observed beneath the well pad.
D. Monitoring Data
1. Monitoring Data
1X1 Is routinely submitted on time Is of acceptable quality
2. Monitoring Data Suggests:
~ Groundwater plume is effectively contained ~ Contaminant concentrations arc declining
E. Monitored Natural Attenuation
1. Monitoring Wells (natural attenuation remedy)
~ Properly secured/locked ~ Functioning ~ Routinely sampled
~ All required wells located ~ Needs maintenance
Remarks:
X. OTHER REMEDIES - W ETLANDS RESTORATION (OU2)
The OU2 wetlands appeared to be in good condition overall. Some invasive species, primarily phragmites, were
observed in OU2. The City of New Bedford has plans to remove it.
The culvert that leads into OU2 had some iron-rich sedimentation.
XI. OVERALL OBSERVATIONS
A. Implementation of the Remedy
Describe issues and observations relating to whether the remedy is effective and functioning as designed.
Begin with a brief statement of what the remedy is designed to accomplish (e.g., to contain contaminant
plume, minimize infiltration and gas emissions).
The OU1 remedy included excavation of contaminated soils/sediments from the Unnamed Stream, water
hazards on the golf course property and other areas of OU1 with placement in the former disposal area,
construction of an impermeable cap, collection and treatment of contaminated groundwater, const met ion
of a landfill gas extraction system, wetlands restoration, long-term monitoring and institutional controls.
The OU2 remedy included excavation of contaminated soils/sediment from parts of Middle Marsh and
Adjacent Wetlands with placement under the OU 1 cap, wetlands restoration, institutional controls and
long-term monitoring. Most of the remedy components are effective and functioning as designed.
Operation of the GWTP was suspended in July 2020 and a post-suspension monitoring began at that time.
Data have shown that total VOC concentrations have rebounded since operation of the GWTP was
suspended, so the system was turned back on in Mav 2023. Additional data evaluation will be needed to
dete^
B. Adequacy of O&M
Describe issues and observations related to the implementation and scope of O&M procedures. In
particular, discuss their relationship to the current and long-term protcctivcness of the remedy.
O&M is adequate at this time.
C. Early Indicators of Potential Remedy Problems
Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high
frequency of unscheduled repairs that suggest that the protcctivcness of the remedy may be compromised
in the future.
Nore.
D. Opportunities for Optimization
Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy.
Opportunities for optimization will be evaluated as part of the FYR.
Site inspection participants:
Kiinberly White, EPA (virtual attendance for the meeting start)
TaChalla Gibeau. EPA (virtual attendance for the meeting start)
Ayana Cunningham, EPA (virtual attendance for the meeting start)
J-9
O Good condition
KIn/a
-------
Aaron Shahccn. EPA
Jennifer Lambert. Nobis Group
Erik Hall. Nobis Group
Chance Perks. City of New Bedford
Michcle Paul. City of New Bedford
Laura Breig, City of New Bedford
David Nieves, City of New Bedford
Jim Costa. City of New Bedford
Johnny Zimmerman-Ward, Skeo
Jill Billus. Skeo
J-10
-------
APPENDIX K - SITE PHOTOGRAPHS
The City of New Bedford
Jon Mitchell, Mayor
tow*."*""*4"*
SunEdison
Signage on the perimeter fence
GWTP building and parking lot
K-l
-------
Signage on the perimeter fence
Interior of the GWTP building
K-2
-------
Solar panels on landfill cap
Culvert under Hathaway Road
K-3
-------
Unnamed Stream
U f -4t-
Golf course near OU2
K-4
-------
Phragmites near 0U2 wetland areas
Erosion under well pad on golf course property
K-5
-------
NOTICE
ALL PLAYERS
NO EXCEPTIONS ||
Hi
Signage on golf course property
Small animal burrow on northwest face of landfill cover
K-6
-------
Landfill cover
Collection trench vaults
K-7
-------
Perimeter fence along southern side of OU1
Soil gas monitoring point GM-4R
K-8
-------
APPENDIX L - EVALUATION OF SOIL CLEANUP LEVELS
coc
ROD Soil
Cleanup
Loci"
(m«/k«)
Composite Worker Soil
RSLb
(mg/kg)
Cancer Risk1'
Noncancer HQ'1
I x I0"6 Risk
HQ= 1
Total PCBs
10e
0.94f
--
1 x 10"5
--
Total Carcinogenic PAHs
30
2.18
2208
1 x 10"5
0.1
Notes:
a) Cleanup levels from the 1989 ROD.
b) Current EPA RSLs. available at httDs://www.eDa.gov/risk/regional-screening-levels-rsls-generic-tables (accessed
5/17/2023).
c) The cancer risks were calculated using the following equation, based on the fact that RSLs arc derived based on
1 x 10"6 risk: cancer risk = (cleanup level ^ cancer-based RSL) x 10"6.
d) The noncancer HQ was calculated using the following equation: HQ = cleanup goal ^ noncancer-based RSL.
e) Most stringent of the soil cleanup levels for total PCBs.
f) RSL for PCBs high risk.
g) RSL for bcn/o(a)pvrene as a surrogate for total carcinogenic PAHs.
L-l
-------
APPENDIX M - VISL CALCULATOR OUTPUT
Evaluated using April 2022 data from well MW-12AR
Commercial Vapor Intrusion Risk
Site
Site
VI
Groundwater
indoor Air
Carcinogenic
VI
VI
Concentration
Concentration
Risk
Carcinogenic
Hazard
VI
CAS
V
CDl
Risk
CDl
Hazard
IUR
IUR
Chemical
Number
-------
Evaluated using October 2020 data from well MW-4A
Commercial Vapor Intrusion Risk
Chemical
Benzene
Dichloroethylene.
cis-1,2-
Vinyl Chloride
Temperature
Site
Site
VI
Groundwater
Indoor Air
Carcinogenic
VI
VI
for
Concentration
Concentration
Risk
Carcinogenic
Hazard
VI
Chronic
Groundwater
CAS
v>
CDI
Risk
CDI
Hazard
IUR
IUR RfC
RfC Vapor
Number
-------
APPENDIX N - 2018 EPA MEMORANDUM
TECHNICAL MEMORANDUM
To: kimberly White
From: Richard Sugatt
Date: August 8, 2018
RE: Development of Groundw ater Risk-Based Concentrations (GW-RBCs) for protection of aquatic
organisms at Sullivan's Ledge Superfund Site
The overall goal of this technical memorandum is to estimate Site contaminant concentrations in groundw ater that
will be protective of aquatic organisms in the sediment and surface water of the unnamed stream that receives
groundw ater from the Site. This technical memorandum provides the follow ing: 1) compilation of benchmarks for
protection of aquatic organisms for chemicals detected in groundw ater at the Site, and 2) Site-specific
Groundw ater Risk-Based Concentrations (GW-RBCs) for protection of aquatic organisms in sediment pore water
and surface water of the stream that receives groundwater from the Site.
Derivation of Benchmarks
Table 1 provides the aquatic toxicity benchmarks for the detected groundwater contaminants selected from the
benchmarks provided in the Risk Assessment Information System (RAIS)
(littps://rais.orn 1.gov/tools/eco search.phpRL). The types of benchmarks are described on the website and
abbreviated in the headings in Table 1, which also presents the minimum, maximum, and geometric mean of the
benchmark concentrations.
The RAIS contains multiple benchmarks for specific organism groups, acute and chronic toxicity, lowest acute or
chronic concentrations, water quality criteria, and different levels of effect (e.g. 20 percent effect concentration.
EC20). Acute benchmarks were not used to be protectively conservative. The R AIS did not have a benchmark for
one of the detected chemicals (carbazole). but a value was found on EPA's Ecotox database
(https://cfbub.epa.gov/ecotox/). The aquatic toxicity benchmarks used for derivation of Massachusetts
Contingency Plan (MCP) GW-3 groundwater standards were also included in Table 1. The GW-3 standards are
intended to be protective for aquatic organisms after attenuation of the chemical in groundwater and dilution into
surface water. These benchmarks were derived from an extensive search of the aquatic toxicity literature and the
benchmark selection process identified in the MCP documentation:
(http://www.mass.gov/eea/agencies/massdep/cleanup/reguIations/documentation-for-gw3-standards.html').
Inspection of the benchmarks in Table 1 for individual chemicals indicates that they vary considerably
(sometimes several orders of magnitude) for the same chemical and that some values are identical, indicating that
they were not independently derived. To minimize both over- and under-protectiveness. as well as potential bias
caused by multiple identical benchmarks, it was decided to use the geometric mean of the selected benchmarks as
a reasonable estimate of the concentration that would have minimal aquatic toxicity. The geometric mean
approach has been used for the widely accepted derivation of consensus-based sediment benchmarks by
MacDonald. et al (2000).
An exception to the use of the geometric mean benchmark was made for chemicals that had chronic National
Recommended Water Quality Criteria (NRWQC). The chronic NRWQC value is called the Criterion Continuous
Concentration (CCC) and is derived from the results of many toxicity tests on multiple species of aquatic
organisms; therefore, the CCC is more scientifically valid than any other benchmark. In addition, the CCC is used
as the M A Surface Water Standard for protection of aquatic organisms. N RWQC values were available for
pentachlorophenol. PCBs. aluminum, arsenic, chromium, copper, iron. lead, mercury, nickel, and lead. The 2004
CCC for copper (9 ug/L) was used because the current method for calculating the copper NRWQC uses a biotic
ligand model that requires measurements of multiple non-toxicant water quality parameters. The new method
could not be used because these parameters were not measured in Site surface water; therefore, the CCC
published prior to the new methodology was used.
N-l
-------
Derivation of GW-RBCs
The EPA GW-RBCs were calculated using an approach similar to the Massachusetts Contingency Plan (MCP) for
derivation of GW-3 groundw ater standards, except that it did not use a dilution factor from sediment pore water to
surface water. The GW-3 standards are designed to be protective for aquatic organisms in surface water after
attenuation of the chemical within the groundwater and dilution into surface water. The GW-3 groundwater
standard is calculated by multiplying the selected toxicity benchmark by an Attenuation Factor (AF) that varies
with the chemical and then by a Dilution Factor (DF) of 10. The GW-3 dilution factor of 10 was not used for the
EPA GW-RBCs because the EPA GW-RBCs are designed to be protective of organisms living within the
sediment exposed to sediment pore water. The EPA GW-RBC will also be protective of organisms in the surface
water because the protective pore water concentration will be even lower after dilution in the surface water.
The documentation in the MCP indicates that the AF depends on the partitioning/absorption characteristics of the
contaminant, with values of 2.5, 25, or 100, depending on the organic carbon partition coefficient (Koc) for
organic contaminants or the soil absorption coefficient (Kd) for inorganic contaminants. In Table 1, the MCP AF
was used if there was a GW-3 standard for a detected chemical. For chemicals that did not have a GW-3 standard,
the AF was assigned based on professional judgement using the following approach:
1. Chemicals with Koc (organic carbon partition coefficient) less than 1000 were assigned an AF = 2.5
2. Chemicals with Koc between 1000 and 100,000 were assigned an AF = 25
3. Chemicals with Koc greater than 100,000 were assigned an AF = 100
For those Site chemicals that do not have GW-3 standards and are not included in the MCP documentation. Koc
values were obtained from the follow ing sources and were then assigned attenuation factors using the same
approach described above:
1. Regional Screening Level (RSL) Chemical Specific Parameters Supporting Table. U.S. EPA, November
2015
2. U.S. EPA Estimation Programs Interface (EPI) Suite-TM
For inorganics, Kd soil partitioning coefficients were used instead of Koc values. Note that Kd values were not
found for calcium, magnesium, and sodium. The derived values are provided in Table 2 below :
Table 2. Attenuation Factors for Chemica
Analvte
Kd
(L/kg)
Koc
(L/kg)
Koc
Source
AF
2-methvlphenol (o-cresol)
3.1E+02
(1)
2.5
4-methvlphenol (p-cresol)
3.0E+02
(1)
2.5
carbazole
9.2E+03
(2)
25
2-chloronaphthalene
2.5E+03
(1)
25
n-nitrosodiphenvlamine
2.6E+03
(1)
25
dibenzofuran
9.2E+03
(1)
25
di-n-butvlphthalate
1.2E+03
(1)
25
isophorone
6.5E+01
(1)
2.5
carbon disulfide
2.2E+01
(1)
2.5
chloroethane
2.2E+01
(1)
2.5
aluminum (pH 6.5-9.0)
1.5E+03
(1)
25
copper (hardness=100
mg/L)
3.5E+01
(1)
2.5
Iron
2.5E+01
(1)
2.5
manganese
6.5E+01
(1)
2.5
s that do not have MCP GW-3 Standards
N-2
-------
There are uncertainties associated with attenuation and dilution within the groundw ater itself because attenuation
can vary based on soil absorption characteristics (e.g. organic matter, grain size, mineral type, redox. pH. etc.) and
length of travel through this soil until it reaches the stream bed. Dilution within the groundwater can vary based
on mixing with other sources of groundwater to a contaminant plume. There are also uncertainties associated with
attenuation and dilution within the sediment as the groundwater moves into the surface water, as well as
uncertainty in the dilution of groundwater into surface water. The actual amount of attenuation and dilution of
groundw ater will decrease as the groundw ater monitoring point approaches the stream itself. Of course, these
uncertainties can be reduced by measuring contaminant concentrations in monitoring points that are either in the
stream (e.g. piezometers) or nearer to the stream than further up-gradient monitoring wells or piezometers.
The GW-RBC is calculated by multiplying the geometric mean benchmark or CCC by the chemical-specific
Attenuation Factor (AF) according to the following equation:
GW-RBC = (geometric mean benchmark, or CCC) x AF
The EPA GW-RBCs are summarized in Table 3 along with the toxicity benchmarks and available MCP GW-3 for
comparison purposes. The EPA GW-RBCs apply to groundwater monitored at any Site-related location other than
at piezometers in the stream itself. The potential aquatic toxicity of contaminants in groundw ater sampled from an
in-stream piezometer would be evaluated by comparison with the geometric mean benchmark or CCC itself, that
is, without attenuation or dilution factors.
The available historic data indicate that barium, iron, manganese and polychlorinated biphenyls (PCBs) may have
exceeded the EPA GW-RBC. Barium, iron, and manganese are know n to become elevated in groundwater under
reducing conditions in which biodegradation of organic contaminants consumes oxygen, resulting in
solubilization of these natural soil minerals into groundw ater. These minerals have low solubility in oxygenated
water so they will precipitate as the reduced groundwater becomes oxygenated as it emerges into surface water.
Evidence for this phenomenon is often seen where rust-colored flocculent material accumulates where
groundwater emerges into surface water. Such precipitation has been observed in the unnamed stream
downgradient from the Site. The precipitation greatly reduces the dissolved concentrations of the inorganics in
sediment pore water and surface water, thereby decreasing the bioavailability and resultant toxicity. Due to likely
precipitation as the groundwater becomes oxygenated as it enters sediment pore water, it is unlikely that the
dissolved concentration of these inorganics is as high as predicted using simple attenuation and dilution factors. It
is concluded that the EPA GW-RBCs for these minerals are probably overprotective due to this phenomenon of
precipitation, which cannot be adequately modeled by simple dilution and attenuation. These inorganics are
unlikely to be able to cause aquatic toxicity in oxygenated sediment pore waters; therefore, any exceedance of the
EPA GW-RBC for these inorganics is not of concern for chemical toxicity to aquatic organisms.
Reference
MacDonald. D. D.. Ingersoll. C. G. and Berger. T. A. 2000. Development and evaluation of consensus-based
sediment quality guidelines for freshwater ecosystems. Arch. Environ. Contain. Toxicol. 39(1): 20-31.
N-3
-------
Tabic 3. EPA Region 1 Groundwater Risk-Based
Concentrations (GW-RBCs)
Analyte
CAS Number
Toxicity
AF
EPA
MCP
Benchmark
(MCP
GW-
GW-3
(mg/L)
or
EPA)
RBC
(mg/L)
Standard
(mg/L)
VOCs
Acetone
67-64-1
1.26E+01
2.5
3.15E+01
5.00E+01
Benzene
71-43-2
4.52E-01
2.5
1.13E+00
1.00E+01
Bis(2-chloroethyl)ether
111-44-4
6.01E+00
2.5
1.50E+01
5.00E+01
Bromodichloromethane
75-27-4
9.30E+00
2.5
2.33E+01
5.00E+01
Carbon Disulfide
75-15-0
1.17E-01
2.5
2.93E-01
NA
Chlorobenzene
108-90-7
1.80E-01
2.5
4.50E-01
1.00E+00
Chloroethane
NA
2.5
NA
NA
Chloroform
67-66-3
2.27E-01
2.5
5.68E-01
2.00E+01
Dichlorobenzene. 1,2-
95-50-1
1.08E-02
2.5
2.70E-02
2.00E+00
Dichlorobenzene. 1,3-
541-73-1
1.14E-01
2.5
2.85E-01
5.00E+01
Dichlorobenzene. 1,4-
106-46-7
2.93E-02
2.5
7.33E-02
8.00E+00
Dichloroethane, 1.1-
75-34-3
5.52E-01
2.5
1.38E+00
2.00E+01
Dichloroethane. 1,2-
107-06-2
2.33E+00
2.5
5.83E+00
2.00E+01
Dichloroethylene. 1.1-
75-35-4
8.55E-01
2.5
2.14E+00
3.00E+01
Dichloroethvlene. 1,2-
540-59-0
2.67E+00
2.5
6.68E+00
NA
Dichloroethylene. 1.2-cis-
56-59-2
1.40E+01
2.5
3.50E+01
5.00E+01
Dichloroethylene. 1.2-trans-
156-60-5
2.21E+00
2.5
5.53E+00
5.00E+01
Ethylbenzene
100-41-4
4.32E-01
2.5
1.08E+00
5.00E+00
Methyl Ethyl Ketone
78-93-3
5.56E+01
2.5
1.39E+02
5.00E+01
Methyl Isobutyl Ketone
108-10-1
3.37E+00
2.5
8.43E+00
5.00E+01
Methylene Chloride
75-09-2
2.37E+00
2.5
5.93E+00
NA
Styrene
100-42-5
1.60E-01
2.5
4.00E-01
6.00E+00
Toluene
108-88-3
2.68E-01
2.5
6.70E-01
4.00E+01
Trichlorobenzene. 1,2,4-
120-82-1
5.98E-02
25
1.50E+00
5.00E+01
T richloroethylene
79-01-6
3.44E-01
2.5
8.60E-01
5.00E+00
Vinyl Chloride
75-01-4
3.76E+00
2.5
9.40E+00
5.00E+01
Xylene, Mixture
1330-20-7
2.97E-01
2.5
7.43 E-01
5.00E+00
SVOCs
Acenaphthene
83-32-9
6.46E-02
25
1.62E+00
1.00E+01
Acenaphthylene
208-96-8
2.60E-02
25
6.50E-01
4.00E-02
Anthracene
120-12-7
1.95E-04
25
4.88E-03
3.00E-02
Benz [a] anthracene
56-55-3
1.74E-04
100
1.74E-02
1.00E+00
Benzo|a|pyrene
50-32-8
5.40E-05
100
5.40E-03
5.00E-01
Benzo| b |fluoranthene
205-99-2
1.95E-03
100
1.95 E-01
4.00E-01
Benzo [g,h,i]perylene
191-24-2
3.91E-04
100
3.91E-02
2.00E-02
Benzo [k] fluoranthene
207-08-9
1.40E-04
100
1.40E-02
1.00E-01
Bis(2-chloroethvl)ether
111-44-4
6.01E+00
2.5
1.50E+01
5.00E+01
Bis(2-cthylhexyl)phthalate
117-81-7
1.27E-02
100
1.27E+00
5.00E+01
N-4
-------
Bromodichloromethane
75-27-4
9.30E+00
2.5
2.33E+01
5.00E+01
Carbazole
86-74-8
9.30E-01
25
2.33E+01
NA
Chloronaphthalene. 2-
91-58-7
4.62E-03
2.5
1.16E-02
NA
Chlorophenol. 2-
95-57-8
6.11E-02
2.5
1.53E-01
7.00E+00
Chrysene
218-01-9
7.00E-04
100
7.00E-02
7.00E-02
C re sol. o-
95-48-7
1.52E-01
2.5
3.80E-01
NA
C re sol. p-
106-44-5
1.95E-01
2.5
4.88E-01
NA
Dibenz [a, h] anthracene
53-70-3
4.47E-04
100
4.47E-02
4.00E-02
Dibenzofuran
132-64-9
2.16E-02
25
5.40E-01
NA
Di-n-butvl Phthalate
84-74-2
6.38E-02
25
1.60E+00
NA
Dimethylphenol. 2,4-
105-67-9
1.93E-01
2.5
4.83E-01
5.00E+01
Fluoranthene
206-44-0
7.51E-03
25
1.88E-01
2.00E-01
Fluorene
86-73-7
3.27E-03
25
8.18E-02
4.00E-02
lndeno| 1.2.3-cd | pyrene
193-39-5
7.77E-04
100
7.77E-02
1.00E-01
Isophorone
78-59-1
1.11 E+00
2.5
2.78E+00
NA
Methylnaphthalene. 2-
91-57-6
6.13E-02
25
1.53 E+00
2.00E+01
Naphthalene
91-20-3
1.14E-01
25
2.85E+00
NA
Nitrosodiphenylamine. N-
86-30-6
2.27E-01
25
5.68E+00
NA
Pentachlorophenol
87-86-5
1.50E-02
2.5
3.75E-02
2.00E-01
Phenanthrene
85-01-8
9.88E-03
25
2.47E-01
1.00E+01
Phenol
108-95-2
2.13E-01
2.5
5.33E-01
2.00E+00
Pyrene
129-00-0
1.63E-04
25
4.08E-03
2.00E-02
PCBs/Pesticides
Polychlorinated Biphenyls
1336-36-3
1.40E-05
100
1.40E-03
1.00E-02
Inorganics
Aluminum
7429-90-5
8.70E-02
25
2.18E+00
NA
Antimonv
7440-36-0
2.96E-01
2.5
7.40E-01
8.00E+00
Arsenic. Inorganic
7440-38-2
1.50E-01
2.5
3.75E-01
9.00E-01
Barium
7440-39-3
3.62E-02
2.5
9.05E-02
5.00E+01
Chromium (trivalent)
16065-83-1
7.40E-02
2.5
1.85E-01
6.00E-01
Copper
7440-50-8
9.00E-03
2.5
2.25E-02
NA
Iron
7439-89-6
1.00E+00
2.5
2.50E+00
NA
Lead
7439-92-1
2.50E-03
2.5
6.25E-03
1.00E-02
Manganese
7439-96-5
3.27E-01
2.5
8.18E-01
NA
Mercury
7439-97-6
7.70E-04
2.5
1.93E-03
2.00E-02
Nickel
7440-02-0
5.20E-02
2.5
1.30E-01
2.00E-01
Silver
7440-22-4
2.87E-04
2.5
7.18E-04
7.00E-03
Vanadium
7440-62-2
5.80E-02
2.5
1.45E-01
4.00E+00
Zinc
7440-66-6
1.20E-01
2.5
3.00E-01
9.00E-01
GW RBC = Groundwater Risk-Based Concentration = toxicity
benchmark X AF
NA = Not Available
AF = Attenuation Factor
N-5
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