NEW BEDFORD — The Environmental Protection Agency has taken significant steps toward developing an Upper Harbor CAD cell to be located above Coggeshall Street near Riverside Park.
The CAD cell, an alternative to sending contaminated sediments off-site, would hold some of the most contaminated sediment in the harbor, according to EPA documents obtained by the Buzzards Bay Coalition through a Freedom of Information Act request that were given to The Standard-Times.
The documents include emails dating as far back as 2006 between EPA and Army Corps of Engineers officials and a 2011 Army Corps of Engineers assessment detailing the dimensions of an Upper Harbor CAD cell that Buzzards Bay Coalition President Mark Rasmussen contended is “just short of an actual contract to build it.”
Confined Aquatic Disposal (CAD) Cells are specially engineered holes to contain contaminated sediment, which have been opposed by local environmental groups who question their safety. So far, the EPA has almost exclusively publicly discussed using the technology for Superfund cleanup in the Lower Harbor. These documents outline internal planning for an Upper Harbor CAD cell by the EPA. When asked about the documents, EPA Region 1 Administrator Curt Spalding said “There is no planning under way now for an Upper Harbor CAD cell at all.” But he said the EPA will officially consider the idea in July when it plans to reopen the Record of Decision regarding harbor cleanup.
“At that time, we would talk about different ways to remedy the harbor,” he said. “There has been no decision made whether an Upper Harbor CAD cell would be part of that discussion.”
In the beginning
CAD cells were first proposed in public at a meeting on Oct. 30, 2008, as a way to clean the cancer-causing polychlorinated biphenyls (PCBs) that currently render the harbor unusable for recreation and fishing. During the meeting, the EPA presented CAD cells as a way to drastically accelerate the harbor cleanup using less money than previously planned.
An EPA slideshow at that meeting showed possible locations for CAD cells with bright yellow boxes. One was located in the Lower Harbor above Pope’s Island, and the other was located in the Upper Harbor between Sawyer Street and Coffin Avenue. Since that time, all public discussions of CAD cells have centered on the Lower Harbor, with digging scheduled to begin this summer.
Environmental groups oppose the use of CAD cells for Superfund cleanup anywhere in the harbor, saying that the cells themselves will be too contaminated. They are also concerned about the risk of humans inhaling PCBs when the PCB-contaminated sediment is exposed to air while it temporarily sits on a split-hulled barge before being dumped into the CAD cell.
“We don’t know of any other site in the country that has successfully buried the concentrations of PCBs planned for the Lower Harbor,” Rasmussen said. EPA officials have maintained that a Lower Harbor CAD cell is a safe alternative to shipping contaminated material off site-to be disposed of in a landfill in Michigan, in part because it would contain only sediment with PCB levels of 50 to 190 parts per million parts sediment.
In contrast, the potential Upper Harbor CAD cell would include sediment that is 68 times more contaminated, with PCB concentrations reaching as high as 13,000 parts per million and averaging in the thousands, according to the December 2011 Army Corps of Engineers assessment.
Also according to that assessment, the Upper Harbor CAD cell would contain 15,000 more cubic yards of contaminated sediment than the Lower Harbor CAD cell.
“Basically they want to take the hottest stuff we have in the harbor — the most dangerous stuff — and bury it right next to Riverside Park,” Rasmussen said.[toggle title=” Public knowledge ” height=”auto”]
Since the 2008 meeting in which the EPA introduced CAD cells to New Bedford, agency officials have publicly kept mum about the possibility of an Upper Harbor CAD cell.
On Oct. 24, 2008, six days prior to the first CAD cell meeting, Army Corps of Engineers Manager Robert Leitch sent an email to various Corps and EPA officials, including then-EPA Project Manager David Dickerson, detailing a conference call earlier that day. Leitch’s email describes Dickerson telling call participants that “the final CAD cell report should focus on the LHCC (Lower Harbor CAD cell) and not include any info/reference on/to the Upper Harbor CAD cell.”
In the four years since the email was sent, the EPA has moved forward with research of both an Upper Harbor CAD cell and a Lower Harbor CAD cell. Emails between EPA and Army Corps of Engineers officials provided to the Standard-Times by the Buzzards Bay Coalition are dated as recently as June 4, 2010, with the Army Corps’ Upper Harbor CAD assessment dated December 2011.
During its community events, the EPA has focused on the Lower Harbor plans. Asked Wednesday if he was aware of a plan for an Upper Harbor CAD cell, Mayor Jon Mitchell said he was not. But, he said, “It is somewhat premature to be talking about specific details concerning disposal of sediments” because the EPA’s settlement with contaminator AVX has not yet been approved by a federal judge.
Edwin Rivera, president of Hands Across the River, said he had not heard about an Upper Harbor CAD cell in any public meeting with the EPA. But, he said “CAD cells are absolutely unacceptable, particularly if they want to put it in front of a park.”
“This isn’t in front of a fish processing plant where you don’t have kids playing, this is next to a park,” he said. “If the mayor lets this happen, he is not advocating for the safety of this city.”
The EPA’s Army Corps of Engineers assessment of a Lower Harbor CAD cell, completed in 2010, is readily available on the EPA’s New Bedford Harbor website. However, the same study for the Upper Harbor CAD cell was not on the site as of 2 p.m. Thursday. That assessment was only obtained through a Freedom of Information Act request by the Buzzards Bay Coalition.
“It certainly doesn’t look good”
EPA Spokesman Jim Murphy said that the Lower Harbor assessment was put online as part of the public comment period on the EPA decision to use a CAD cell in the Lower Harbor. The Upper Harbor assessment was not put online “because people have not asked for it,” he said.
“Each region has restrictions on how much stuff we can put on the website. We just can’t put everything up there,” he said. “It’s not like we are trying to hide anything, but I get that it certainly doesn’t look good.” He added that the Upper Harbor assessment would be uploaded shortly.
At a Sept. 21, 2012, meeting with the Standard-Times editorial board, EPA administrator Spalding denied any intent by the EPA to place a CAD cell in the Upper Harbor.
“I’ve seen some letters written to us with people suggesting we are going to CAD the whole thing; that is not going to happen and will not happen,” he said. “It never was under consideration and nobody ever thought we were going to take these high levels of contamination that are in the upper harbor and put them in CADs.”
On Thursday, Murphy clarified Spalding’s September comments, saying that the Region 1 administrator “didn’t know” about the assessment.
“It’s not Curt’s job to know about every document,” he said.
On Wednesday, Spalding told The Standard-Times that the EPA has neglected to mention considerations for an Upper Harbor CAD cell because “no one was thinking about it very seriously.”
“It might have been helpful to share that (the assessment) was being done, but the point of view of the team is that they weren’t seriously considering it,” Spalding said. “They were talking about things that they were really thinking about doing, and not things they weren’t seriously thinking about.”
Emails between the EPA and Army Corps of Engineers indicate that The Army Corps assessment of the Upper Harbor cost the EPA somewhere between $10,000 and $12,000.
That document, like its Lower Harbor counterpart, details not only the dimensions and PCB concentrations of the CAD cell, but also describes ways to prevent contamination while filling the CAD cell, and also calculates the percentage of PCBs that could seep out of the CAD cell over the next 40 years.
Emails between EPA and Army Corps of Engineers officials discuss the possibility of buying equipment that could be used to dig both the Upper and Lower Harbor CAD cells.
Buzzards Bay Coalition President Rasmussen said he believes the EPA’s silence about an Upper Harbor CAD cell is purposeful.
“While we were all discussing the Lower Harbor CAD cell, they were going ahead and doing this work for the Upper Harbor,” Rasmussen said. “How can they hold public meetings and not even mention they are considering this? They were making a conscious decision not to talk about it.”
Though the public was not apprised of the EPA’s Upper Harbor CAD cell considerations, AVX was.
AVX is the successor to Aerovox, the party responsible for contaminating the harbor with PCBs.
In August 2008, Weldon Bosworth, the principal scientist to AVX for its independent evaluation of the EPA’s harbor cleanup, wrote an email to then-EPA Project Manager Dickerson.
“Hi Dave, AVX has asked me to evaluate the likelihood and potential cost of siting a CAD in the Upper Estuary as a potential alternative to off-site disposal that you had discussed as at our last meeting,” he wrote.
Dickerson responded by asking EPA scientists to forward Bosworth information about the upper harbor’s geology.
Reached at his New Hampshire-based office, Bosworth said he could not comment on an Upper Harbor CAD cell until AVX’s $366 million settlement to pay for the harbor’s cleanup has been approved by a federal judge. “With what’s going on right now relative to the settlement, I’ve been asked not to talk about it,” he said.
In March 2011, the EPA released an Explanation of Significant Differences, which officially allowed the use of a Lower Harbor CAD cell.
During the public comment period on that document, AVX filed multiple complaints that the EPA had not gone ahead with an Upper Harbor CAD cell at the same time. The agency responded that, “EPA will continue its evaluation of an additional CAD cell, located in the Upper Harbor.”
“Since this evaluation is not currently complete, while the evaluation of the Lower Harbor CAD cell is, EPA is only proceeding with the Lower Harbor CAD cell at this time,” the agency responded.
What does this mean?
Rasmussen said that he is worried about the existence of plans for an Upper Harbor CAD cell and, in particular, AVX’s knowledge of those plans. Rasmussen, who said he believes that the $366 million settlement between EPA and AVX is not enough money to clean the harbor, said he fears that once the settlement is approved in federal court the EPA will change its cleanup plan to include the Upper Harbor CAD cell.
“The only way that $366 million makes sense to me is if the EPA thinks they can get away with an Upper Harbor CAD cell,” Rasmussen said.
Spalding said Wednesday he could not comment “on specifics regarding the settlement” because its public comment period lasts until Dec. 17.
“What’s at issue in this settlement is that we had a $15 million per year budget with no prospect for more money,” he said. “We saw the opportunity to get more money and that is what we have pursued legally.”
Spalding did say that in July, the EPA plans to conduct a “focus feasibility study” that would reassess the use of Confined Disposal Facilities (CDFs), which would hold contaminated sediment in bulkheads lining the banks of the Upper Harbor.
Replacing CDFs with off-site disposal of sediment was briefly considered by the EPA in 2001. In 2002, the EPA decided to use three CDFs, instead of the originally proposed four. The current remedy still includes placing 175,000 cubic yards of sediments in CDFs.
The feasibility study would look at whether the EPA should use CDFs in harbor remediation. As part of that, the EPA is required to look at alternatives to replace the CDFs, which could include an Upper Harbor CAD cell.
“We have to ask the questions about all of the alternatives because of due diligence requirements,” Spalding said.
In the event that the EPA decides to change the current cleanup methods there would not necessarily be a public comment period.
If the agency decides that replacing CDFs with an Upper Harbor CAD cell constitutes “a fundamental change … to the basic features of the remedy selected,” a public comment period would be part of that process.
If the EPA decides the replacement is not a “fundamental change,” it can switch the remedies using an Explanation of Significant Differences (ESD), which is described as “only a notice of change” in EPA Guidelines and does not require a public comment period.
In 2010, when the EPA used an ESD in its decision to use a CAD cell in the Lower Harbor, it included a public comment period in an effort to assuage community fears.
Spalding said that while a public comment period could be optional in changing harbor cleanup practices, “There will be a full and open conversation about what is best for the harbor and what’s best for the community.”
For Rasmussen, though, the EPA will have to work to regain community trust.
“The EPA often expresses shock and dismay that we don’t take what they say at face value,” he said. “But how does planning this CAD cell behind our back build a record of trust?”
About Ariel Wittenberg
Ariel Wittenberg is an environmental reporter at the in Southeastern Massachusetts. She also covers the town of Fairhaven, Mass., and spends her days learning the finer points of wind turbines, toxic waste and town government. She has previously worked at , where she researched campaign finance reform and the Center for Public Integrity, where she covered the nation’s foreclosure crisis.
A graduate of Brandeis University, she was editor-in-chief of the campus newspaper where her projects ranged from covering the university budget to writing a four-part series on the intersections of race at the university. She has also written for the Waltham News Tribune and the Metro West Daily News.
Top of page [/toggle] Water related articles by Ariel Wittenberg
Some worry Parker site cleanup puts neighbors at risk of contamination (Standard-Times, Sept. 2012)
[Note by STW™ : PCB Article that may affect groundwater.] EPA orders AVX to takeover harbor cleanup, complete it in eight years (Standard-Times, April 2012)
Harbor faces unique obstacles in nitrogen pollution (Standard-Times, May 2012)
STW™ : New Bedford Harbor – CAD Cell research material.
Assessment of Contaminant Loss and Sizing for Proposed Upper Harbor Confined Aquatic Disposal (CAD) Cell / New Bedford Harbor Superfund Site Massachusetts: PDF / 111 page report
New Bedford Harbor Superfund Site / Administrative Record File / Upper and Lower Harbor
Explanation of Significant Differences (2010 Upper and Lower Harbor ESD) PDF 13 page report
EPA Cleanups: New Bedford Harbor: Website information with videos and maps / Updated on Fri. Dec. 28, 2012.
Commonwealth of Massachusetts : New Bedford Harbor Superfund Site NRD Settlement: Website information.
Harbor Contamination with PCBs
From the late 1940s to the late 1970s, electric capacitor manufacturing plants operated along the shore of New Bedford Harbor in southeastern Massachusetts. The Aerovox plant is located at the northernmost end of the inner Harbor on the Acushnet River Estuary, where the Acushnet River flows into the Harbor. The Cornell-Dubilier plant is a short distance south (i.e., seaward) of a structure known as the Hurricane Barrier, which separates the inner Harbor from the outer Harbor.
Both the Aerovox and Cornell-Dubilier plants used poly-chlorinated bi-phenyls (PCBs), a probable human carcinogen, in the capacitors from approximately 1947 to 1978. During that period, the buildings, structures, and grounds of both plants became contaminated with PCBs from accidental spills and intentional dumping. These PCBs were transported onto the adjoining shorelines and into the Harbor through the pipes, drains, troughs, storm runoff, and intentional dumping over the years of PCB operations.
PCBs released from the Aerovox and Cornell-Dubilier plants contaminated the sediments of the Upper Estuary at levels ranging up to 190,000 parts per million (ppm). The PCBs in sediments are continually released into the water. The PCBs are taken up by fish and shellfish and have been found in many species — including lobsters, flounders, eels, and bluefish — at concentrations well above safe levels for eating. This contamination led Massachusetts in 1979 to:
- Close an 18-square-mile area of the Harbor to lobstering;
- Close a smaller area to all fishing for bottom-feeding species such as flounder, tautog, scup, and eels; and
- Ban fishing entirely in a northern section of the Acushnet River Estuary.
Of the nearly 100,000 population of New Bedford, nearly 40% are Portuguese, so that signs banning fishing were always displayed in Portuguese and English to effectively warn the community of the dangers from eating the fish.
CERCLA Civil Complaint
In 1983, the Justice Department filed a civil complaint under CERCLA, the Superfund law, charging that the defendants that had operated at the two plants were responsible for the releases of PCBs from the manufacturing plants adjacent to the Harbor. Massachusetts also filed its complaint at that time. Both complaints sought damages for the injured natural resources, and cleanup costs.
- After years of extensive litigation, the final settlement in the case was reached in 1992, and provided the United States with more than $100 million to clean up the harbor and restore the natural resources.
- EPA is using its share of the funds to implement an extensive multi-year dredging project in the Harbor to remove the contaminated sediments from the Inner Harbor.
- The federal and Massachusetts natural resource trustees are using natural resource recovery monies to plan and implement the actions to restore the natural resources and services harmed by the releases of PCBs into the Harbor.
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Lower Harbor Confined Aquatic Disposal (CAD) Cell
You will need Adobe Reader to view some of the files on this page. See EPA’s PDF page to learn more.
- CAD Cell Workgroup Meetings
- Technical Workgroup Documents
- CAD Cell Q&A
- Pre-design Historic Data and Investigations
CAD Cell Workgroup Meetings
- April 25, 2012 Meeting Presentations
- Discussion of Potential Air Impacts (PDF) (14 pp, 3.1MB) posted 5/1/12
- Overview of Ambient Air PCB Air Monitoring Program (PDF) (6 pp, 1.5MB) posted 5/1/12
- CAD Modeling (PDF) (19 pp, 2.6MB) posted 5/1/12
- Risk Assessment Presentation (PDF) (11 pp, 1.1MB) posted 5/1/12
- April 2, 2012 Meeting Presentations
- March 2012 Meeting Presentations (PDF) (79 pp, 14.2MB)
Technical Workgroup Documents
EPA CAD cell docs
- CAD Cell Drawings 09-01-2012 (PDF) (14 pp, 7MB) posted 10/12/12
- CAD Cell Specifications, Invitation for Bid 09-01-2012 (PDF) (333 pp, 5.9MB) posted 10/12/12
- EPA Responses to Questions Raised by the Buzzards Bay Coalition from 04/25/2012 Meeting of the Technical Working Group Regarding Air Issues, May 22, 2012 (PDF) (15 pp, 2.9MB)
- Draft Final Lower Harbor CAD Cell Sampling and Analysis Plan, March 2012 (PDF) (1,586 pp, 107.9MB) posted 5/9/12
- New Bedford Harbor USEPA Lower Harbor CAD Cell Workplan, December 2011 (PDF) (19 pp, 407K)
NBH Water Quality Monitoring
- 2009 Toxicity Analysis Report – Biomonitoring of Surface Water Samples from Sampling Event, July 2009 (PDF) (63 pp, 2.5MB) posted 5/9/12
- Explanation of New Bedford Harbor Operational Monitoring Approaches, April 24, 2012 (PDF) (5 pp, 666K) posted 5/9/12
- Environmental Monitoring of Remedial Dredging at the New Bedford Harbor Superfund Site, December 23, 2004 (PDF) (19 pp, 1.6MB) posted 5/9/12
- Development and Use of Site-Specific Chemical and Biological Criteria for Assessing New Bedford Harbor Pilot Dredging Project, 1991 (PDF) (8 pp, 629K) posted 5/9/12
New Bedford Harbor Navigational CAD Cells
- SER Navigational Dredging Work Protocols, April 13, 2012 (PDF) (20 pp, 506K) posted 5/9/12
- Phase II Water Quality Monitoring Results 01/13/2005 – 07/22/2005 (PDF) (65 pp, 6.1MB) posted 5/9/12
- Water Quality Monitoring Report Dredge and Disposal Operations Phase II – Part 1 Fish Island Area and Top of CAD Cell, February 28, 2005 (PDF) (9 pp, 558K) posted 5/9/12
- Water Quality Monitoring Report Dredge and Disposal Operations Phase II – Part 1 Fish Island Area and Top of CAD Cell, February 5, 2004 (PDF) (10 pp, 598K) posted 5/9/12
- Water Quality Monitoring Report Dredge and Cap Placement Operations Phase II – Completion of Initial Construction of CAD Cell and OU3 Cap Placement, July 7, 2005 (PDF) (28 pp, 3.4MB) posted 5/9/12
- Water Quality Monitoring Report Dredge and Cap Placement Operations Phase II – Completion of Initial Construction of CAD Cell and OU3 Cap Placement, July 26, 2005 (PDF) (26 pp, 3.5MB) posted 5/9/12
- CAD Cell 2 – Top of CAD Water Quality Monitoring Turbidity Measurements, July 8, 2008 (PDF) (1 pg, 232K) posted 5/9/12
- Water Quality Monitoring Report Dredge Project Phase II Part 2, January 17, 2006 (PDF) (69 pp, 2.1MB) posted 5/9/12
Volumes, Areas and Properties of Sediment by Management Units, NBH Site (2003)
- Volumes, Areas and Properties of Sediment by Management Units, Revision 2, September 12, 2003 (PDF) (118 pp, 21.5MB) posted 5/9/12
New Bedford Harbor Air Quality Monitoring
- Draft Final Development of PCB Air Action Levels for the Protection of the Public New Bedford Harbor Superfund Site, December 2001 (PDF) (321pp, 22.1MB)
CAD Cell Q&A
Printable version of CAD Cell Fact Sheet (PDF) (2 pp, 1MB)
What is a CAD Cell?
The New Bedford Harbor Superfund CAD cell will be a man-made, capped underwater containment cell. First the area for the CAD cell is dug into the harbor floor, excavating the sediment to create the space for the CAD. The original material is excavated and taken to an approved off-shore facility or reused for beneficial uses if appropriate. Contaminated sediment from the harbor will then be placed into the CAD cell, allowed time to consolidate and then capped. The contaminated sediment is held in place by existing clean sediments on the sides and bottom of the cell, and a cap on the top. CAD cells have been used successfully for contaminated navigational sediments in New Bedford as well as many other ports and waterways including Boston and Providence. A simplified schematic of how the CAD cell will be constructed is shown to the right.
When did EPA decide to use a CAD cell?
The decision to build the CAD cell was made in March 2011 by the US EPA after public comment. The CAD cell is being designed now – early in 2012. Construction is expected to begin later in the year. The CAD cell will be located in a state-approved area in New Bedford Harbor between the I-195 and Rt. 6 bridges.
Why has EPA chosen to use a CAD cell in New Bedford Harbor?
The CAD cell will enable completion of the lower harbor cleanup more quickly, and at a lower cost. The CAD cell was selected for the disposal of 300,000 cubic yards of sediment containing between 50-190 ppm of PCBs located mostly in the lower harbor south of the I-195 bridge. These levels are much lower than the levels found in the upper harbor, which range up to four thousand ppm of PCBs.
How long will the CAD cell project take to complete?
The CAD cell is anticipated to be dug beginning this year and completed in 2013. The time and cost to complete the harbor cleanup, including the filling of the CAD cell with contaminated material and the capping of the CAD cell, depends entirely on annual funding appropriations. Keeping in mind the decades-long timeframe that remains for cleanup of the harbor, there can be no guarantee what future funding levels will be.
How much of New Bedford Harbor will be cleaned up as a result of using the CAD cell?
After the CAD cell is filled, more than 80% of the geographic area of (the Upper and Lower Harbor Operable Unit) the New Bedford Harbor Superfund Site requiring cleanup under the Superfund program will be safely disposed of into the CAD cell. Specifically, almost all of the sediment exceeding Superfund cleanup levels located between Sawyer Street to the north and the hurricane barrier to the south (approximately 300,000 cubic yards) will be disposed of into the CAD cell.
How do you know it will be safe to install the CAD cell and keep it sealed?
Data collected and evaluated during the construction of other CAD cells, including in New Bedford, supports EPA’s determination that a CAD cell is a safe, permanent solution for disposing of contaminated Harbor sediment. EPA has also conducted computer modeling of potential leakage of contaminants which shows that a CAD cell located in New Bedford Harbor would be stable and not subject to leakage to the environment.. EPA will conduct an extensive program of monitoring air, water, and sediment during the project and make the data available to the public. As with any cleanup site, if significant issues arise during design and construction of a remedy, we would re-evaluate the issue(s) to make sure that our remedy protects human health and the environment. EPA does not intend to move forward with any remedy that does not protect the health of New Bedford citizens, or the harbor.
Who is performing the design and construction?
The work is being performed through a cooperative agreement that EPA has signed with the New Bedford Harbor Development Commission (HDC) which has extensive experience with the construction and filling of CAD cells. The HDC has hired APEX Companies, LLC to design and construct the CAD cell. APEX has prior experience designing and overseeing construction of navigational CAD cells in New Bedford Harbor.
How can I get more information about the CAD cell project?
In addition to ongoing community outreach, EPA has funded a “Technical Assistance Grant” or “TAG” to the Buzzard’s Bay Coalition. Dr. Frank Bohlen of the Department of Marine Sciences at the University of Connecticut has been hired with TAG funds to review technical information about the project. As part of the EPA decision to design, construct, and fill a CAD cell, a technical workgroup (TWG) open to individuals and organizations interested in the project was formed to review and discuss design and construction documents. Dr. Bohlen will be attending the TWG meetings to provide technical input to the group, address community questions about technical aspects of the project, and provide feedback to EPA.
What are some elements of a TAG?
The TAG program provides money to community groups to pay for technical advisors to interpret and explain technical reports, site conditions, and EPA’s current and future cleanup plans
Once EPA has provided the $50,000 grant, it can be used for up to three years with extensions possible if needed and Additional TAG funds may be available. Only one TAG can be given for each Superfund site.
Pre-design Historic Data and Investigations
Apex Companies, LLC Cover Memo to Harbor Development Commission
- Memo: Apex Companies, LLC to New Bedford Harbor Development Commission regarding pre-design investigations for the Lower Harbor CAD Cell, February 16, 2012 (PDF) (7 pp, 1.3MB)
Harbor Bottom Bathymetry Data
This information outlines the existing bathymetry, measured in feet below Mean Lower Low Water, of the existing bottom of the harbor within the area anticipated to be utilized to construct the LHCC. It includes the following figure, which is a visual representation of the bathymetry:
Harbor Sediment Boring Data
This information includes both historic and more recent borings, as well as geotechnical analytical data generated from those borings, that have been advanced within the area where the LHCC is being considered to be sited. Geotechnical analytical data is also included that is representative of material to be placed into the LHCC. The data includes the following:
- Historic Boring Logs (PDF) (461 pp, 33.1MB)
- Historic Geotechnical Analytical Data (PDF) (261 pp, 11.1MB)
- Historic Organic Silt-Clay Hydraulic Conductivity Data (PDF) (10 pp, 2.8MB)
- LHCC Boring Logs (PDF) (25 pp, 4MB)
- Partial LHCC Geotechnical Analytical Data (PDF) (60 pp, 2.3MB)
- Figure 2 – Boring Location Plan, Apex Companies, LLC. (PDF) (1 pg, 1.2MB)
CAD Cell Pre-design Historical Data
This is historic information that is relevant to the siting and design of the LHCC. It is organized into a number of sub-categories as follows:
Historic Air Evaluations
This information has been provided (along with the New Bedford Superfund Site Risk Assessments) to address concerns by the public regarding the risks associated with concentrations of PCBs in air. It includes the following reports:
- Evaluation of the Impact of Dredging and CAD Cell Disposal on Air Quality, Jacobs Engineering Group, June 2010 (PDF) (57 pp, 6.3MB)
Historic New Bedford Harbor Superfund Risk Assessments
This information has been provided to provide a background for the human health and ecological risks associated with PCBs in New Bedford Harbor that drove the 1998 Record of Decision and subsequent Explanations of Significant Differences, including the Lower Harbor CAD Cell.
- Draft Final Baseline Public Health Risk Assessment, EBASCO, August 1989 (PDF) (190 pp, 4.3MB)
- Draft Final Baseline Ecological Risk Assessment, EBASCO, April 1990 (PDF) (204 pp, 3.5MB)
Historic USEPA LHCC Feasibility Assessments
This information has been provided to outline the assessments USEPA conducted prior to implementing the Explanation of Significant Differences associated with the LHCC.
- Assessment of Contaminant Loss and Sizing for Proposed Lower Harbor Confined Aquatic Disposal (CAD) Cell, USACE Engineer Research and Development Center, May 2010 (PDF) (262 pp, 14.3MB)
- Turbidity Monitoring and Plume Sampling Results for City Dredge Disposal at the New Bedford Harbor CAD Cell #2, Battelle, December, 2009 (PDF) (83 pp, 12.2MB)
Historic Background Material and Literature
This information has been provided to outline background information regarding CAD Cells, as well as some background information regarding the mass of PCBs associated with the New Bedford Harbor Superfund Site.
- Estimate of Mass of PCBs in New Bedford Harbor, EBASCO, April, 1989 (PDF) (1 pg, 40K)
- USACE Leaching/Pore Water Analysis (PDF) (1 pg, 35K)
- Understanding the Physical and Environmental Consequences of Dredged Material Disposal: History in New England and Current Perspectives, Fredette and French, 2004 (PDF) (10 pp, 1MB)
- Why Confined Aquatic Disposal Cells Often Make Sense, Fredette, 2005 (PDF) (4 pp, 1.3MB)
Historic Remote Sensing Reports
This information includes remote sensing reports that have been prepared within the area where the LHCC is being considered to be sited:
- Underwater Archeological Remote Sensing Survey, Dolan Research, Inc., January 2000 (Revised March 2001) (PDF) (57 pp, 1.3MB)
- Underwater Archeological and Hazards Analysis, Remote Sensing Survey, Apex Environmental, Inc., March 2003 (PDF) (75 pp, 4.6MB)
Historic Navigational Dredging Water Quality Measurements
This information includes water quality measurements that have been completed associated with the Phase II and Phase III Navigational Dredging program, which included mechanical dredging, and placement of material into CAD Cells.
- Phase II Water Quality Monitoring (PDF) (65 pp, 6.1MB)
- Phase III Water Quality Monitoring (PDF) (5 pp, 1MB)
Historic Suspended Sediment Transport Modeling and Measurement
This information includes transport modeling associated with CAD Cell planning associated with the Dredge Material Management Plan process as well as a flux analysis conducted by EPA indicating the quantity of contaminated sediment entering Buzzard’s Bay under existing conditions.
- Dredge Material Transport Modeling Analysis, Maguire Group, July 2003 (PDF) (77 pp, 2.5MB)
- New Bedford Harbor PCB Flux Study, Woods Hole Group, Inc., August 2010 (PDF) (53 pp, 4.1MB)
Historic Toxicity Testing
This information includes toxicity testing associated with suspended sediment anticipated to be generated during placement of contaminated material into CAD Cells.
This information includes geophysics reports (seismic and sub-bottom analyses) that have been prepared for the area anticipated to be utilized to construct the LHCC. This information is primarily historic.
- CDF D Geophysics (PDF) (5 pp, 3.4MB)
- Report of Marine Geophysical Surveys: Seismic Refraction, Sub-Aqueous Disposal Cell Feasibility Studies, Apex Environmental, Inc., 2001 (PDF) (46 pp, 1.4MB)
- Addendum To Marine Geophysical Surveys: Seismic Refraction, Sub-Aqueous Disposal Cell Feasibility Studies, Updated Data and Model Revision, Maguire Group, 2003 (PDF) (40 pp, 1.3MB)
This information includes vibracores that have been advanced within the area where the LHCC is being considered to be sited. This information is primarily historic. Information to supplement this data is currently being generated, but is not currently available:
- Historic Vibracore Logs (PDF) (77 pp, 6.1MB)
- Figure 3 – Historic Vibracore Location Plan, Apex Companies, LLC (PDF) (1 pg, 1.2MB)
Conceptual LHCC Siting Plans
These figures have been generated to outline a number of conceptual locations for the proposed LHCC. Once a location has been finalized, final design of the LHCC will begin.
- Figure 4: Conceptual LHCC Location Plan 1: Shows one potential location for the Lower Harbor CAD Cell (PDF) (1 pg, 1.2MB)
- Figure 5: Conceptual LHCC Location Plan 2: Shows one potential location for the Lower Harbor CAD Cell (PDF) (1 pg, 1.2MB)
- Figure 6: Conceptual LHCC Location Plan 3: Shows one potential location for the Lower Harbor CAD Cell (PDF) (1 pg, 1.2MB)
- Figure 7: Conceptual LHCC Location Plan 4: Shows one potential location for the Lower Harbor CAD Cell (PDF) (1 pg, 1.2MB)
- Figure 8: Conceptual LHCC Location Plan 5: Shows one potential location for the Lower Harbor CAD Cell (PDF) (1 pg, 1.2MB)
- Figure 9: Conceptual LHCC Location Plan 6: Shows one potential location for the Lower Harbor CAD Cell (PDF) (1 pg, 1.2MB)
This particular scenario assumes that the LHCC would be combined with a CAD Cell needed for future Navigational Dredging.