Clamshell Dredging To Remediate PCB Contamination has Harmed The Hudson River, and Further Clamshell Dredging Would Further Harm the River

Oct 30

Clamshell Dredging To Remediate PCB Contamination has Harmed The Hudson River, and Further Clamshell Dredging Would Further Harm the River. Comments of Dr. Robert A. Michaels! and Dr. Uriel M. Oko?

22 July 2024

On 10 July 2024 the US EPA (10) issued a News Release inviting public comment on the third five-year review of the Agency’s dredging project to remediate PCB contamination of the Hudson River (11). We hereby transmit our comments, consisting of this transmittal letter together with its package of accompanying documents. Our comments are summarized by our 8-December 2023 Times Union Newspaper Commentary (01), and fully supported technically by the body of our previous public comments on Hudson River PCB dredging (02) and scientific publications spanning the full duration of the dredging project (03-09). These submitted documents are cited fully below, and incorporated into our comments by reference as well as by attachment to this transmittal letter.

EPA’s News Release (10) reports the principal conclusion of the five-year review: monitoring of river sediment, water, and fish “shows progress” toward meeting cleanup goals, but EPA needs more fish data “after” the historic cleanup. We begin with our most fundamental comment: The title text in EPA’s News Release, “after historic Hudson River cleanup” (10), implies misleadingly that the cleanup is complete. This implication is belied by EPA’s principal conclusion (11) and by the body text of its News Release (10), that is, the “need for more data” to decide the issue of completeness. According to the News Release: “The data... will help the EPA understand how well the river is recovering and guide the Agency’s next steps.” Our comment is not a quibble. The misleading EPA News Release suggests Agency bias, which we likewise reported as early as 2007 (07). Persistent EPA bias undermines current Agency credibility.

Our Times Union Newspaper Commentary (01) explains why the dredging project failed, and why EPA’s plan to collect more data will not detect this failure. Most generally, data gathered during dredging was extensive but, even so, inadequate. As a result, available data irrevocably fail to quantify massive PCB sediment mobilization by dredging, which we document in our publications (01-09). Dredging-mobilized PCB sediment cannot be recollected into areas where EPA will gather more data.

PCB concentrations in fish tissue eventually will decline in dredged river sectors, but fish in undredged downstream areas will be exposed to mobilized PCB sediments over decades. Natural degradation will be the main means of PCB exposure attenuation. The dredging project has harmed Hudson River ecosystems, and will continue to harm Hudson River ecosystems, whether or not EPA documents such harm via further data collection in the next several years.

As a corollary to his conclusion, we suggest that any further dredging of the Hudson River should rely upon hydraulic (‘vacuum’) dredging, not clamshell dredging. Clamshell dredging is appropriate for navigational dredging of otherwise clean waterways. It is inappropriate for environmental dredging because it massively mobilizes contaminated sediments, as we have documented abundantly.

1. Dr. Robert A. Michaels, PhD, CEP; RAM TRAC Corporation, Schenectady, NY; bam@ramtrac.com 2. Dr. Uriel M. Oko, PhD, PE; Recycle Management, Glenmont, NY; um.oko81@gmail.com

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Literature Cited

Michaels, Robert A.; and Uriel M. Oko. Commentary: PCB dredging has not helped the Hudson River. Here's why. Albany, New York; Times Union Newspaper, https ://www. researchgate.net/publication/376353712 Commentary PCB dredging has_not

helped the Hudson River Here%27s why Albany New York Times Union Newspaper 8 December 2023, 8 December 2023;

Michaels, Robert A.; and Uriel M. Oko. Negative Hudson River Superfund remediation effectiveness: clamshell dredging massively mobilized sediments, increasing PCB contamination. In: Public Comments Received on Proposed Second Five-Year Report, EPA Index Number 374, pages 493-562 (69 pages including appendices), submitted 30 August 2017, https://www.epa.gov/sites/production/files/2018-01/documents/updated_11-3017 2017 fyr comments - individuals reduced _1.pdf, published online 17 January 2018;

Michaels, Robert A.; and Uriel M. Oko. Lessons learned from legacy contaminants of emerging concern: Hudson River PCB dredging. Albany, New York State Bar Association (NYSBA), The New York Environmental Lawyer, 37(2):58-74, Fall 2017;

Michaels, Robert A.; and Uriel M. Oko. Negative Hudson River Superfund remediation effectiveness: clamshell dredging massively mobilized sediments, increasing PCB contamination. Comments on US EPA’s Proposed Second Five-Year Review. Collingswood, New Jersey, The Certified Environmental Professional (Newsletter of the Academy of BoardCertified Environmental Professionals; ABCEP), pages 4-6, September 2017;

Michaels, Robert A.; and Uriel M. Oko. Excessive PCBs in the Hudson River: attributable to incompleteness of dredging, or to seven years of dredging? Routledge, Taylor & Francis Group, Environmental Claims Journal, 29(2):115-40, 2017; online: http://dx.doi.org/10.1080/10406026.2017.1307007, 25 April 2017c;

Michaels, Robert A.; and Uriel M. Oko. Hudson River PCB dredging: mid-course assessment, and implications regarding possible project continuation vs. termination. Environmental Practice, 12(4):377-94, December 2010;

Michaels, Robert A.; and Uriel M. Oko. Bias in the US EPA baseline health risk assessment supporting the decision to require dredging of PCB-bearing sediments from the Hudson River. Environmental Practice, 9(2):96-111, June 2007;

Michaels, Robert A. Health impact assessment: the influence of bias in EPA’s decision to dredge PCB from Hudson River sediments. Conference presentation. Albuquerque, New Mexico; Proceedings of the National Association of Environmental Professionals Annual Meeting; 14 pages, 21 April 2006;

Michaels, Robert A. The emperor’s new clothes and the US EPA’s decision to dredge Hudson River PCBs. Environmental Practice, 7(3), September 2005;

US EPA. FPA invites public comment on review that shows progress and need for more data after

historic Hudson River PCB cleanup. News Release, https://www.epa.gov/newsreleases/epa-

invites-public-comment-review-shows-progress-and-need-more-data-after-historic, 10 July 2024;

US EPA. DRAFT Third Five-Year Review Report for the Hudson River PCBs Superfund Site. New York City, U. S. Environmental Protection Agency, Region 2, 100 pages plus Appendices, July 2024.

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CONTENTS

Section title

Page number

TRANSMITTAL

Literature Cited

EXHIBITS

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Michaels, Robert A.; and Uriel M. Oko. Commentary: PCB dredging has not helped the Hudson River. Here's why.

Michaels, Robert A.; and Uriel M. Oko. Negative Hudson River Superfund remediation effectiveness: clamshell dredging massively mobilized sediments, increasing PCB contamination.

Michaels, Robert A.; and Uriel M. Oko. Lessons learned from legacy contaminants of emerging concern: Hudson River PCB dredging.

Michaels, Robert A.; and Uriel M. Oko. Excessive PCBs in the Hudson River: attributable to incompleteness of dredging, or to seven years of dredging?

Michaels, Robert A. The emperor’s new clothes and the US EPA’s decision to dredge Hudson River PCBs. Environmental Practice, 7(3), September 2005.

page 3

EXHIBITS

page 4

Exhibit

01. Michaels, Robert A.; and Uriel M. Oko. Commentary: PCB dredging has not helped the Hudson River. Here's why. Albany, New York; Times Union Newspaper, https://www.researchgate.net/publication/376353712 Commentary PCB dredging has not

helped the Hudson River Here%27s why Albany New York Times Union Newspaper 8 December 2023, 8 December 2023

page 5

Commentary: PCB dredging has not helped the Hudson River. Here's why.

The choice of dredging method removed only a fraction of the contaminants, and the EPA's monitoring of progress has been insufficient.

Dec 8, 2023

Dredgers at work in the Hudson River near Fort Edward on July 26, 2011. Provided by Robert Michaels

In 2005, the U.S. Environmental Protection Agency mandated that the General Electric Company dredge about 40 miles of the Hudson River between Fort Edward and Troy because of a persistent trickle of PCBs into the river. Today the EPA is readying its latest assessment of

river recovery, some 15 years after dredging. It’s an opportune time to note that in fact, the dredging further damaged the river and set back its recovery.

GE’s consent decree with EPA left open the choice of dredging method. GE chose clamshell dredging, which is cheaper than hydraulic dredging. However, such dredging disturbs the river bottom, sending massive amounts of PCB-contaminated sediment downstream.

In 2007, in a peer-reviewed article, we predicted the inevitable failure of clamshell dredging. Our follow-up articles in 2010 and 2017 documented its actual failure.

During on-site visits, we observed black, sediment-laden water pouring from partially closed dredge buckets suspended over the river surface. Dredge spoils often included construction debris and other large objects such as tree stumps, bicycles, cement blocks and boulders. Such objects prevented buckets from closing tightly and securing their contents. Further, dredge buckets weighing tons repeatedly pounded the river bottom. As each bucket closed, its walls created severe turbulence that mobilized dense clouds of resuspended sediment.

We used dredge bucket sizes and the EPA’s computerized “bucket files,” which recorded each dredge bucket descent and sediment lift, to quantify the fraction of dredged material that was placed into waiting barges. We found that some 75 to 80 percent of the material entering buckets fell back to the river. That is, the amount dumped into waiting barges was only about a quarter of the amount dredged. Moreover, this estimate is conservative because it omits the sediment mobilized by the dredging.

To document dredging success, the EPA required intensive environmental monitoring, but it was not intensive enough. It severely undercounted mobilized PCB-contaminated sediment and PCBs in the air. EPA knew that its dredging success criteria were being contravened, but instead of acknowledging failure, EPA weakened the criteria used to rate success.

Instead of measuring mobilized sediment directly, EPA had GE measure “resuspended” sediments, which means just the small fraction of mobilized sediment that enters the water column. Most is left alone, resting on the bottom, but there it is loose and still mobile due to river currents and storms.

EPA initially required resuspension to be within 1 percent of the total dredged, but this limit was routinely exceeded. So EPA doubled the limit to be within 2 percent. EPA also had the measurement taken 1,000 meters upstream of the dredge site instead of at the “dredge head.” Of course, the river flows downstream, so the separation of dredging from measuring allowed much of the mobilized sediment to drop back to the river bottom, out of the reach of samplers.

Meanwhile, the river and storms have moved PCB-containing sediment along the river bottom.

PCBs have entered the river ecosystem in both flora and fauna, including fish. Fish are consumed by predators like birds, which spread the chemicals beyond the river. People catch fish for sport and, often, consumption. PCB levels in the ecosystem including fish are unlikely to decline to acceptable levels for generations.

We support environmentally friendly dredging methods that minimize PCB mobilization, such as coffer damming and hydraulic dredging. Coffer damming walls off riverbed sections to remove water so excavators can dig up and remove exposed sediments. Hydraulic dredging, in contrast, captures nearly all contaminated sediment by vacuuming it off the riverbed directly into barges. Hydraulic dredging has become the norm for environmental dredging. Clamshell dredging, in contrast, is dirty — so dirty that it usually is reserved for reopening navigation channels.

Use of clamshells for dredging PCB-contaminated Hudson River sediments was an unwise decision. Clamshell dredging did not improve the river, but instead, further damaged it. If environmental groups wish to have EPA impose further PCB dredging responsibilities on GE, clamshells should be off the table.

Robert Michaels is a toxicologist with RAM TRAC Corporation in Schenectady. Uriel Oko is an engineer with Recycle Management in Glenmont.

Exhibit

02. Michaels, Robert A.; and Uriel M. Oko. Negative Hudson River Superfund remediation effectiveness: clamshell dredging massively mobilized sediments, increasing PCB contamination. In: Public Comments Received on Proposed Second Five-Year Report, EPA Index Number 374, pages 493-562 (69 pages including appendices), submitted 30 August 2017, https://www.epa.gov/sites/production/files/2018-01/documents/updated_11-3017 2017 fyr comments - individuals reduced _i.pdf, published online 17 January 2018

page 9

Negative Hudson River Superfund remediation effectiveness: clamshell dredging massively mobilized sediments,

increasing PCB contamination

Comments on US EPA’s Proposed Second Five-Year Review Robert A. Michaels!, PhD, CEP; and Uriel M. Oko*, PhD, PE 30 August 2017

We have studied the proposal to dredge, and its implementation, since 2007 (Michaels and Oko, 2007, 2010, 2017a; Appendices 1-3; Michaels and Oko 2017b, in press). Our contributions regarding reasonably anticipated and actual project effectiveness were ignored in EPA’s first five-year evaluation (US EPA 2012) and in its proposed second five-year review (US EPA 2017). Our studies ignored by EPA focused on all stages of the dredging proposal, starting with EPA's a priori assumptions (Michaels and Oko 2007). We concluded that EPA’s analysis to justify dredging was biased, based upon our findings that critical assumptions made by the Agency were erroneous, and that all identified errors were made in the dredgingfriendly direction rather than randomly.

We then studied dredging while in progress, during Phase 1 of the project, and found critical deficiencies in the project and in monitoring programs to document it (Michaels and Oko 2010). Most recently we studied dredging during and after Phase 2 (Michaels and Oko, 2017a; Appendix 3; and Michaels and Oko 2017b, in press). We reported negative Hudson River Superfund Site remediation effectiveness: clamshell dredging massively mobilized sediments, increasing PCB contamination rather than decreasing it. Our purpose in providing these comments is to motivate EPA to address the serious concerns that we have expressed both publically and privately regarding the expected and the actual performance of the clamshell dredging project.

Our 2007 and 2010 peer-reviewed Environmental Practice articles (Michaels and Oko 2007, 2010; Appendices 1 and 2) predicted that primitive clamshell dredging in the Hudson River would massively mobilize buried PCB sediments, and spread them to an expanding area of river ecosystems that include fish and birds. Clamshells basically are floating backhoes that are useful for navigational dredging. Our 2017 articles (Michaels and Oko 2017a, Appendix 3; Michaels and Oko 2017b in press) analyze the structure of clamshell dredge buckets used in the Hudson River, and the computerized dredge bucket data produced on each closure (the ‘pucket files’). We found that 75-80 percent of dredged sediment is returned to the river in mobile form, rather than removed to waiting barges for off-site disposal.

1 Robert A. Michaels, PhD, CEP; RAM TRAC Corporation, Schenectady, NY; ram@ramtrac.com ? Uriel M. Oko, PhD, PE; Recycle Management, Glenmont, NY; umoko@nycap.rr.com

Comments of Michaels and Oko

Safe PCB dredging requires more advanced hydraulic (suction) technology to minimize toxic sediment mobilization. That’s what environmental advocates have advocated, and that’s what environmental advocates have achieved, for example, in the New Bedford Harbor in Massachusetts, the Cumberland Bay in Plattsburgh, New York; and in the Fox River in Green Bay, Wisconsin. That’s what a year-long advertising campaign said that GE would do in the Hudson River PCBs Superfund Site, though that plan was abandoned in favor of clamshells.

The New York State Department of Environmental Conservation recently reported to the U. S. Environmental Protection Agency that GE’s seven-year clamshell dredging project has failed to meet its cleanup goal, to reduce safely and substantially the long-term downstream transport of PCBs. This has resulted, most notably, in the project leaving excess PCB levels in fish, which will not abate to acceptable levels for human consumption for most of a century. DEC appropriately called for extensive sampling for PCBs “all the way to New York City,” and called on EPA to finish the job and hold GE accountable for cleaning up the Hudson

River.

The question of whether remnant PCB-contaminated sediments can be removed via further clamshell dredging, however, depends upon whether PCBs are elevated because dredging remains incomplete, or because dredging was undertaken over a seven-year period. Our research indicates that PCB mobilization constitutes an ecological cost of PCB sediment removal via clamshell dredging. Mobilization already has far exceeded the minute amounts of PCBs seeping into the river that initially motivated and justified the dredging remedy.

EPA effectively has obscured this reality by failing to monitor dredge mobilization of PCB sediments, instead focusing on ‘resuspension’. As EPA’s Peer Review Panel (Peer Review

Panel 2012) informing the Agency’s first five-year review wrote:

“There is a very real need to set an allowable load limit for the Hudson River dredging project, but neither the data nor tools needed to do so currently exist. To that end, the project must develop a set of models that incorporate hydrodynamics, sediment transport, fate and transport of PCBs, and bioaccumulation of PCBs in the Upper Hudson River from Fort Edward to Troy Dam” (page 36).

detected in ‘resuspension monitoring’ at great distance from each dredge site. Indeed, even

Comments of Michaels and Oko

this tiny fraction exceeded EPA’s engineering performance standard, which resulted in EPA changing the standard and the monitoring location (Michaels and Oko 2010). The massive amounts of sediment dropped back to the river bottom are mobile: they can be and will be moved downstream episodically when storms or other events produce high-flow conditions in

the river.

We termed this the ‘sediment mobilization discrepancy’. It represents more than merely a difference between a predicted vs. a measured parameter value. It represents a fundamental inconsistency in EPA’s past justification of the need to dredge versus EPA’s current characterization of the performance of the dredging project. The need for dredging was justified by the observed, persistent mobility of PCB sediments requiring, according to EPA, their removal via dredging. In contrast, in the new context of actual dredging, EPA dramatically has altered its concept of mobility. Mobility in the dredging project is newly quantified by the miniscule fraction of mobilized (resuspended’) PCB that is detected at significant distance downstream. Thus, EPA has ignored nearly all sediment and PCB mobilization in evaluating compliance with the Engineering Performance Standard for resuspension. In ignoring mobility of PCB-containing dredge-mobilized sediments for gauging compliance with the resuspension EPS, EPA has ignored a much larger degree of PCB sediment mobility than that which constituted EPA’s most essential basis for requiring, in 2007, remediation of the Hudson River PCBs Superfund Site via dredging.

Additional clamshell dredging demanded by many in the environmental community would do more damage. Political correctness cannot change the reality that clamshell dredging was and remains a bad idea for the Hudson River. Its PCB-sensitive species including endangered sturgeon and American eagles already have had more than enough PCB

exposure due to clamshell dredging.

Long-term remediation projects undertaken under the Federal Superfund Act or its state equivalents are subject to five-year reviews. As dredging Hudson River PCBs was mandated in 2007, the first five-year review of the project was undertaken as required in 2012 (US EPA 2012). Accordingly, one of us (Michaels) informed EPA of the emerging link between PCBs and possible causation of autism and, in a public comment, suggested that the scheduled five-year review address this issue relative to numerous river communities alongside the path of the dredging project. The five-year review (US EPA 2012), however, neither addressed this issue substantively, nor alluded to it. Indeed, the word ‘autism’ was absent from the 82-page report. Given the high and increasing prevalence of autism, and its seriousness, cost, and apparent linkage to environmental agents that may include maternal exposure to PCBs during pregnancy, extending the dredging project should be predicated upon

satisfactory consideration of this emerging public health issue.

Comments of Michaels and Oko

The next five-year review of the dredging project is underway. On 31 May 2017, EPA released the proposed “Second Five-Year Review” for public comment. As with the first review, the second neither addresses the autism issue nor alludes to it. Indeed, the word ‘autism’ as before is absent from the 81-page report, notwithstanding several reports in the literature that were cited and considered in Michaels and Oko (2010, 2017a, b). Both published papers predate release of EPA’s proposed "Second Five-Year Review.”

The issues of whether EPA should consider the autism issue, and whether the officially completed GE Hudson River dredging project should be extended to remediate remnant PCBs, both must be viewed in the context of EPA’s longstanding special mandate regarding children’s health, embodied by EPA’s Children’s Health Risk Initiative (US EPA 2001). In 1997 the Office of Children’s Health Protection was instituted within EPA. Its mission was and remains “to make children’s health protection a fundamental goal of public health and environmental protection... [by] ensuring strong standards that protect children’s health...” In short, EPA must be conservative, not only in protecting the scientific knowledge base, but in protecting public health, including children’s health (Michaels 2017).

Indeed, all three of our already-published papers (Michaels and Oko 2007, 2010, 2017a), which are highly critical of EPA’s project methods and effectiveness, are excluded from citation and from consideration by EPA’s proposed “Second Five-Year Review,” just as in 2012 EPA excluded from its first five-year review our two then-existing peer-reviewed published papers. We respectfully call upon EPA to respond to our comments in its upcoming response document, and consider our reports in the final version of the Agency’s “Second

Five-Year Review.”

Literature Cited

1. Michaels, Robert A. Confidence in courts: a delicate balance. Science, 357(6353):764, Letters, DOI: 10.1126/science.aao3967, 25 August 2017;

2. Michaels, Robert A.; and Uriel M. Oko. Bias in the US Environmental Protection

Agency’s Health Risk Assessment Supporting the Decision to Require Dredging PCB-Bearing Sediments from the Hudson River. Environmental Practice (Cambridge University Press), 9:96-111, 2007;

3. Michaels, Robert A.; and Uriel M. Oko. Hudson River PCB Dredging: Midcourse Assessment and Implications Regarding Possible Project Continuation.

Environmental Practice (Cambridge University Press), 9:377-94, 2010;

Comments of Michaels and Oko

Michaels, Robert A.; and Uriel M. Oko. Excessive PCBs in the Hudson River: attributable to incompleteness of dredging, or to seven years of dredging? Environmental Claims Journal, 29(2):115-40, 2017a; online: http://dx.doi.org/10.1080/10406026.2017.1307007, 25 April 2017a;

Michaels, Robert A.; and Uriel M. Oko. Lessons learned from legacy contaminants of emerging concern: Hudson River PCB dredging. Albany, New York State Bar Association, NYSBA Environmental Lawyer, 37(2), in press, Autumn 2017b;

Peer Review Panel. Hudson River PCBs Site Peer Review of Phase 1 Dredging, Final Report. Under contract to US Environmental Protection Agency, Washington, DC (Contract No. EP-W-09-011), 102 pages including appendices. Available at http://www.epa.gov/hudson/pdf/hudsonriver phaselidredgingreport_final.pdf, 2010;

US EPA. Region 2's Management of Children’s Health Risk Initiative and Related Projects. Office of Inspector General Audit Report, Grant Management, Report No. 2001-P-

00002, 129 pages, https://www.epa.gov/sites/production/files/2015-

12/documents/kidshealth.pdf, 30 January 2001;

US EPA. First Five-Year Review Report for Hudson River PCBs Superfund Site. New York City, U. S. Environmental Protection Agency, Region 2, Emergency and Remedial Response Division, 82 pages, 1 June 2012;

US EPA. Proposed Second Five-Year Review Report for Hudson River PCBs Superfund Site. New York City, U. S. Environmental Protection Agency, Region 2, Emergency and Remedial Response Division; 81 pages plus 15 Appendices, https://www.epa.gov/ny/second-five-year-review-report-hudson-river-pcbs-

superfund-site-report-text-appendices-0, 31 May 2017.

Comments of Michaels and Oko

Appendices

Appendix 1:

Michaels, Robert A.; and Uriel M. Oko. Bias in the U. S. Environmental Protection Agency’s Health Risk Assessment supporting the decision to require dredging PCB-bearing sediments from the Hudson River. Environmental Practice (Cambridge University Press), 9:96-111, 2007

Appendix 2:

Michaels, Robert A.; and Uriel M. Oko. Hudson River PCB Dredging: midcourse assessment and implications regarding possible project continuation. Environmental Practice

(Cambridge University Press), 9:377-94, 2010

Appendix 3:

Michaels, Robert A.; and Uriel M. Oko. Excessive PCBs in the Hudson River: attributable to incompleteness of dredging, or to seven years of dredging? Environmental Claims Journal, 29(2):115-40, 2017; online: http://dx.doi.org/10.1080/10406026.2017.1307007, 25 April 2017

Appendix 1

9:96-111, 2007

COMMENTARY

Bias in the US Environmental Protection Agency’s Baseline Health Risk Assessment Supporting the Decision

to Require Dredging of PCB-Bearing Sediments from the Hudson River

Robert A. Michaels, Uriel M. Oko

The US Environmental Protection Agency’s (EPA) baseline Hudson River health risk assessment (HRA) is evaluated and found to be biased toward keeping polychlorinated biphenyls (PCBs) in sediments. The HRA systematically misquantified parameters, underestimating PCB movement from sediments to water and from water to air. The EPA excluded from its analysis all mono- and dichlorinated PCB congeners, which EPA subsequently estimated at one-third of total PCB mass in the river, and excluded dissolved and colloidal PCB. The EPA included silt-adsorbed PCB, but overestimated the rate at which it would settle out of the water column by inappropriately basing the rate on Stokes’ Law for more massive spherical particles. Flat clay particles settle more slowly with a longer path length and residence time. The EPA omitted electrostatic charges on clay particles that separate them, preventing agglomeration and maintaining clay in suspension; they also assumed that particles never “reflect” back into the water column after settling, likewise underestimating PCB concentrations in water. Also omitted was PCB codistillation, in which PCBs at low bulk concentrations preferentially distribute to the air-water interface, accelerating PCB transfer from water to air. Indeed, EPA cited empirical data showing more rapid PCB waterto-air transfer, but reduced its effect on the HRA, reducing the transfer coefficient by averaging in lower modeled PCB

transfer coefficients that ignored codistillation. Finally, EPA

96 Environmental Practice 9 (2) June 2007

omitted PCB release to the atmosphere from hot water in cooling towers in communities along the Hudson River. Water at cooling tower temperatures may release PCB into the air more than 10 times faster than rates determined from the surface of cold water and multiple orders of magnitude more rapidly than in EPA’s models. Together, EPA’s procedures reduced airborne PCB concentrations from above to below de minimis concentrations. This, in turn, eliminated the requirement for EPA’s HRA to quantify inhalation risks posed by airborne PCBs; the HRA, therefore, considered airborne PCBs, but attributed zero health risk to them. Environmental Practice 9:96—-111 (2007)

History and Administrative Procedure

F rom 1947 to 1977, the General Electric Company (GE) used polychlorinated biphenyls (PCBs; see Figure 1) at Hudson River facilities in Hudson Falls and Fort Edward, directly and indirectly discharging permitted and nonpermitted PCBs into the river. These PCBs adhered to river sediments and were transported widely (US Environmental Protection Agency, 2006a). Available records, which were later used to inventory PCBs discharged from GE’s two plants during this interval, produced estimates of direct discharges reaching 1,330,000 pounds (6.0 X 10° kg). The actual amount is unknown. Indirect discharges and discharges by other parties and from other sources would be incremental. If the preponderance of disposal was to land, then indirect discharges to the river could have exceeded direct discharges.

PCBs, detected in fish in 1969, were banned from manufacture and commerce in 1974 with passage of the Toxic Substances Control Act. In 1975, the New York State De-

Affiliation of authors: Robert A. Michaels, RAM TRAC Corporation, Schenectady, New York; Uriel M. Oko, Recycle Management, Glenmont, New York

Address correspondence to: Robert A. Michaels, President, RAM TRAC Corporation, 3100 Rosendale Road, Schenectady, NY 12309; (e-mail) ram@ramtrac.com.

DOI:10.1017/S1466046607070160

Cl Cl

Figure 1. A pentachlorinated PCB congener.

partment of Health issued health advisories to limit consumption of PCB-laden fish, and the New York State Department of Environmental Conservation successfully sued to force GE to study PCB contamination and abatement. Dredging thereby became an administrative issue. In 1984, the US Environmental Protection Agency (EPA) added the Hudson River PCBs Superfund Site to the National Priorities List (NPL), thereby requiring study and possibly remediation under the 1980 Superfund Law.

The 1984 NPL listing decision produced a Record of Decision in which EPA asserted the eventual need to address PCB contamination in the Upper Hudson River. The Record of Decision specified an interim decision, however, to require “No Action” to remediate PCB in sediments, based upon EPA uncertainty about the reliability and effectiveness of available remedial technologies. Accordingly, in 1991 the remediation issue was revisited via a reassessment Remedial Investigation and Feasibility Study. Numerous documents support site reassessment, and their full text is available on the Internet (see US Environmental Protection Agency, 2006b). In February 2002, EPA issued a new Record of Decision requiring GE to dredge PCB-contaminated sediments from the Upper Hudson River, beginning with a demonstration project to evaluate the dredging approach.

Purpose, Scope, and Overview

Administrative procedure under Superfund involves interested parties (stakeholders), by design introducing politics into EPA administrative procedure. The present study addresses the question of whether, despite political influence, dredging is justifiable by the science of health risk assessment (HRA). The EPA apparently justified its decision to require dredging based upon a baseline assessment of PCB risks, not an assessment quantifying PCB risks potentially

posed under dredging scenarios (US Environmental Protection Agency, 1999, 2000a, 2000b). An HRA should compare potential risks under specific dredging scenarios with baseline risks following completion of the demonstration dredging project. For this comparison process to be valid, baseline risks potentially posed by all relevant exposure routes, including PCB inhalation, should have been estimated in a valid and unbiased manner. The present study addresses this issue.

Selection of Parameters

The issue of bias must be addressed via evaluation of a fair, rather than a biased, selection of EPA’s parameters. A random selection of parameters is neither required nor appropriate; we focus narrowly upon mis-estimated parameters. Accordingly, our procedure was to evaluate EPA’s analysis and systematically ignore all parameters whose use by EPA was technically justified. Parameters of interest to us are not those of greatest a priori concern (quantitatively most important in determining risk). In our investigation, parameters that were accurately estimated were dropped from concern, no matter how important they might have been quantitatively in determining risk. We identified nine parameters whose evaluation by EPA was found to be technically deficient. In short, we did not “cherry-pick” parameters to bias our analysis in a particular direction. Our analysis, of course, is verifiable against cited EPA documents.

The Criterion of Bias

The bias issue is addressed qualitatively, as well as supported and augmented quantitatively (statistically). Both approaches rely on the simple premise that the direction of errors in analyses of independent (non-covariant) parameters approaches randomness as the number of parameters increases. Randomness of error direction, therefore, is the null hypothesis. Its rejection is justified technically if a low-probability pattern of error directions is observed, such as mis-estimation of a large number of independent parameters in a consistent direction, either permissive to dredging or contraindicating dredging. Observing such a low-probability distribution of error directions, whether or not based upon quantitative (statistical) analysis, would support the conclusion of bias, although not necessarily of intentional bias.

The Public Policy Issue

Under a consent decree, GE would pay the lion’s share of Hudson River restoration costs. The costs, measured in

Bias in the EPA’s HRA Regarding PCBs in the Hudson River 97

hundreds of millions of dollars initially and probably over a billion dollars cumulatively for limited PCB “hotspot” dredging, make the Hudson River a sediment “megasite.” Projected remedial costs far exceed median costs for sediment sites and far exceed costs ranging from $19,000 to $812,000 per project paid for achieving the various goals of 37,099 river restoration projects listed in the National River Restoration Science Synthesis database (Bernhardt et al., 2005). For example, median costs for instream habitat improvement projects were reported to be $20,000; for water quality management, $19,000; and for channel reconfiguration, $120,000. These costs impart urgency to the task of revealing any bias, or resolving any appearance of bias, in the scientific analyses informing the dredging decision.

The Public Health Issue

Adding to the urgency of evaluating possible bias, PCBs have been associated with numerous adverse human health effects (Agency for Toxic Substances and Disease Registry, 2000; Buckley and Tofflemire, 1983; Carpenter, 1998; Carpenter, 2005; Carpenter et al., 2003; Chase et al., 1982; Choi et al., 2003; Hennig et al., 2002; Lucier, 1991; Slim et al., 1999; Stehr-Green et al., 1989; Taylor, Stelma, and Lawrence, 1989). Effects include higher incidence of low-birthweight infants among residents of zip codes of PCB disposal sites (Baibergenova et al., 2003) and, more recently, higher hospitalization rates for coronary heart disease in zip codes with PCB contamination (Carpenter, 2005). PCBs are animal carcinogens and probable human carcinogens (Agency for Toxic Substances and Disease Registry, 2000).

Confounding Issues

Dredging has become confounded with equity—essentially, how much GE should pay for damaging the Hudson River and environs. A proper separation of the equity issue from other dredging issues is essential to unbiased, objective, and otherwise competent scientific decision making. We omit consideration of equity issues.’ Indeed, any penalty or finding of liability assessed against GE can be applied toward dredging and/or used for other purposes. Thus, the amount of any penalty that might be assessed against GE should be unaffected by this article.

The Opportunity to Decide Issues

The EPA now has postponed dredging to 2009, affording an opportunity to consider whether dredging constitutes the best use of resources. For example, could possible adverse PCB health effects be offset more effectively via less

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expensive but more health-enhancing strategies, such as health club memberships for families residing along the Hudson River? More germane to PCBs, could greater health benefits be derived by using GE funds to establish a research institute focusing on local epidemiological issues? Resolution of these issues is outside our scope. We focus narrowly on evaluating the possible role of bias in EPA scientific analyses to decide whether or not Hudson River PCBs might pose unacceptable risks under a dredging and/or non-dredging (“baseline”) scenario.

Methods

This investigation adopts the methods of health risk assessment (HRA) and health impact assessment (HIA) to identify parameters used by EPA to assess baseline (nondredging) health risks potentially posed by PCBs in the Hudson River and, essentially, peer review their quantification based upon EPA documentation. Two criteria were used to determine whether effective insulation of science from politics was attained: (1) whether parameter values were estimated accurately, and (2) with respect to any parameters evaluated inaccurately, whether the direction of estimation error was mixed or whether it consistently overestimated or underestimated potential PCB transfer from Hudson River water to air. Overestimating the risk of transferring PCBs from sediments to water and water to air in the vicinity of Hudson River communities could contraindicate dredging, whereas the reverse error would be conducive to dredging.

The null hypothesis is absence of bias. This corresponds to finding a random distribution of errors, not to finding an absence of errors. Any finding of significant systematic error in either direction constitutes evidence of bias, justifying rejection of the null hypothesis.

Statistical Analysis

We determined whether each parameter examined was estimated correctly. If EPA’s evaluation of a parameter was grossly inaccurate, we included it among parameters to be examined statistically to determine whether the distribution of the directions of mis-estimation was non-random. Each parameter that is estimated inaccurately must be overestimated or underestimated (otherwise, it is accurate). If these outcomes can be assumed to be equally probable, then occurrence of each is associated with an equal expected probability of 0.5 (50%, or “fifty-fifty”). If the parameters also are independent (mis-estimating one

parameter does not affect estimation of another), then any two randomly selected parameters that are mis-estimated would have a 0.25 probability (P = 0.5 X 0.5 = 0.25) of being mis-estimated in a direction more permissive to dredging and, likewise, 0.25 would be the probability of the same two parameters being mis-estimated in a direction less permissive to dredging.

In general, the probability of mis-estimating all of n parameters consistently in a particular direction by chance alone is 0.5" where, for example, the probability of misestimating five out of five parameters in a direction permissive to dredging would be 0.03 (P = 0.55 = 0.03). When probabilities reach such low values, below the usual 0.05 criterion of scientific uncertainty, the null hypothesis of randomness is rejected. Speaking qualitatively, bias in the outcome of EPA’s analysis (possibly unintentional) would be inferred.

Secondary Methods

Secondary methods also were applied. They are not a priori methods and they are not described in detail here. Rather, they are the diverse methods typical of peer review, which most essentially consists of considering the scientific merit with which numerous methods were selected for use and applied in the original analyses supporting the dredging decision. Readers can judge for themselves whether or not we applied the methods of HRA, HIA, and peer review objectively.

Findings

EPA Identification of Parameters Used in Assessing Potential Risks Posed by PCBs

The number of parameters describing the dynamics of PCBs entering the water column from sediments and entering the air from the water column are diverse and numerous, numbering in the hundreds or thousands. The number visible in any scientific explication of this issue depends upon the degree of detail with which the analysis is conducted. The parameters include initial concentrations of all 209 PCB congeners (from monochlorinated to decachlorinated biphenyls) in each medium, bulk amounts, areas involved, and depths of water and sediments, as well as parameters describing the physical, chemical, and environmental degradation (such as half life), transformation (such as dechlorination), and other environmental dynam-

ics (such as solubility, boiling point, volatilization, and vapor density) of these numerous congeners. The safety issue also encompasses toxicological parameters of each PCB congener. The full list of such parameters is too long to elucidate in detail here.

Fortunately, the present analysis requires no such highly detailed elucidation. The parameters that are of greatest concern here are those that are most susceptible to being overestimated or underestimated, especially if by a wide margin, or overlooked entirely. These are the parameters (unlike, say, molecular weights, which are known to a high degree of accuracy) whose estimated values substantially may depend upon who is doing the estimating. Quantification of these parameters can vary from liberal to conservative, depending upon whether the estimator has an (conscious or unconscious) agenda other than to conduct a purely scientific analysis ... in short, a bias. Nine such estimated, determinative parameters that were (or should have been) used for technical analysis in the baseline HRA supporting the dredging decision were identified in the current study, as follows:

1. Mobilization of sediment-borne PCBs in dredging. Sediment-borne PCBs will become mobilized by dredging. The amount mobilized depends upon the dredging method. Mobilization must be considered in assessing the potential public health significance of PCB dredging;

2. PCB congeners to be included in the analysis. All 209 PCB congeners should be included;

3. Phases of PCBs to be included in the analysis. All phases should be included, most notably PCBs that are adsorbed onto particles, molecular PCBs that are dissolved, and particulate PCBs that are colloidal;

4. Precipitation of PCB-bearing sediment particles from the water column. Precipitation rates should be quantified realistically, because this parameter is important in determining the rate of PCB removal (to sediments) and the resulting PCB concentration in the water column;

5. Electrostatic charges on PCB-bearing sediment particles in the water column. Clay sediment particles resuspended in water (as by dredging) tend to exhibit negative surface charges. Such particles are maintained in suspension by electrostatic interaction of the negative surface charges with cations (positive ions) in the water. This electrostatic charge configuration inhibits agglomeration. It should be accounted for because of its potential importance in inhibiting settling of clay particles and removal of adsorbed PCB from the water column;

Bias in the EPA’s HRA Regarding PCBs in the Hudson River 99

6. Reflection coefficient of precipitating PCB-bearing sediment particles. The reflection coefficient quantifies the tendency of particles, once settled out of the water column, to return to the water column as a result of “bouncing.” The reflection coefficient should be quantified and is especially important for particles of low mass or likely to be affected by currents, as in the Hudson River;

7. PCB codistillation. Codistillation is a chemical process well documented for PCBs. It results from molecular attraction to surfaces. For PCBs, these surfaces include the air-water interface in lakes and rivers. Entry of PCBs into air from water is significantly faster and more extensive in a given interval than would be the case if the same mass of waterborne PCBs were assumed to be distributed evenly throughout the water column (as quantified by the “bulk concentration”). Accurate estimation of waterborne PCB entry into the air that people will breathe requires quantification of PCB codistillation;

8. Empirical measurement of airborne PCBs over PCBcontaminated waters. Empirical measurements, to the extent available, should be used for validating modeled relationships, such as models of PCB entry into the air from Hudson River water;

9. Warm water sources of Hudson River PCB entry into the atmosphere. Warm water occurs at near-shore locations where cooling water is discharged from industrial facilities and, before discharge, in cooling towers supplied by Hudson River water. These sources of potential entry of PCBs into the atmosphere near population centers must be accounted for when assessing potential public health significance of PCBs and the possibly increased significance to public health if PCB dredging is undertaken.

The technical merit of EPA quantification of each parameter described above is evaluated sequentially in the following subsections.

Mobilization of Sediment-Borne PCBs in Dredging

PCB mobilization must be considered in assessing the potential public health significance of PCB dredging. Its consideration by EPA, however, was inadequate. PCB mobilization exacerbated by dredging depends upon three types of causes:

1. sediment disruption, as by extreme weather events or barge sinkings;

2. the method of dredging; and

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3. accounting in full, rather than in part, for PCBs that might be mobilized.

Sediment Disruption by Extreme Weather Events

Research undertaken by Joel Baker and colleagues at the Chesapeake Biological Laboratory in Maryland simulating Hudson River PCB dredging (Baker et al., 2001) revealed that EPA modeling lacked spatial resolution high enough to predict PCB mobilization reliably. They concluded that errors, which could have gone in either direction, probably had in fact underestimated sediment and PCB mobilization from extreme weather events. The authors used this finding to argue in favor of dredging, fearing that harmful PCBs would be mobilized in future years if dredging did not remove them sooner; however, removal by dredging presumably also could exert a nearer-term effect episodically.

The Method of Dredging

The EPA's assessment regarding the Hudson River PCB site was prepared in 1999 and 2000, when GE planned to dredge hydraulically via the “suction” method. Indeed, a television commercial campaign by GE impugned the “clamshell” or “bucket” method of dredging as being too dirty. Since preparation of the HRA, however, GE’s proposal has reverted to use of the clamshell method.

Accounting in Full for PCBs That Might Be Mobilized

The mass of PCB that will be mobilized may be expressed as a fraction of the inventory of PCB in Hudson River sediments. If the inventory is underestimated, mobilization will be underestimated commensurately. This source of underestimation is addressed with respect to other parameters, below.

In short, EPA’s modeled estimate of PCB mobilization from sediments to the water column and from the water column to the air, together contributing to potential PCB inhalation risks, failed to include important potential sources of PCBs and therefore is unreliable for predicting dynamics in the Hudson River if dredging of PCB-bearing sediments at hotspots actually is undertaken.

PCB Congeners to be Included in the Analysis

All PCB congeners should be included in the inventory of PCBs in Hudson River sediments (Figure 1). Mono- and dichlorinated PCBs, however, were excluded from the in-

ventory of PCBs in Hudson River water, thereby underestimating waterborne PCBs subject to becoming airborne. Several figures in the revised Hudson River HRA (US Environmental Protection Agency, 1999, 2000a, 2000b) depict a precipitous falloff of “total trit PCB congener water column concentrations” within approximately 10 meters of the dredge site. PCB congeners can bind from one to ten chlorine atoms. If each number of chlorines were represented equally, exclusion of the monochlorinated and dichlorinated PCBs would represent two of ten (20%). The actual fraction (weight-percent) excluded is unclear because commercial PCBs were sold as Aroclors (for example, Aroclor 1254 with 54 weight-percent chlorine), such that each Aroclor product sold had a distinctive distribution of mono- to decachlorinated PCB congeners (hence the ability to “fingerprint” PCB sources). In addition, PCB degradation in sediments results in gradual dechlorination, which tends to deplete the high-chlorine congeners and enrich the low-chlorine congeners ... precisely the congeners that were excluded from the figures and which apparently were excluded from consideration in quantifying PCB release from river water to air. The fraction of total PCBs represented by the monochlorinated and dichlorinated PCBs would appear to be about one-third, as suggested by an EPA estimate described below.

The plan to dredge Hudson River sediments selected one option from among several remediation options. The option favored by environmentalists, “Alternative no. 5,” would remove 155,000 pounds of PCBs, compared with 1.3 million pounds (650 tons, or approximately 600,000 kg); the latter is the amount reported to have been deposited into the Hudson River by GE from its two upriver capacitor plants before PCBs were banned from US commerce by the Toxic Substances Control Act of 1976. Responding to criticism of the plan to dredge only 100,000 pounds of PCBs under a less ambitious option, GE provided “new data” to the EPA that showed that the actual amount of PCBs that would be dredged from the river bottom under Alternative no. 5 would be 150,000 pounds, almost identical to the amount preferred by environmental groups (Cappiello, 2001):

The US EPA says it can dredge 50 percent more PCBs from the Hudson River without increasing the volume of sediment removed. (Cappiello, 2001)

By way of explanation, EPA indicated that it simply had refined its PCB estimate of a year earlier; they did this by including previously-excluded monochlorinated and dichlorinated PCBs, on the rationale (according to TAMS Consultants) that “fish principally absorb [higher chlorinated] PCBs.”

The EPA apparently assumed that the monochlorinated and dichlorinated PCBs constituted one-third of the total PCBs (50,000 pounds out of 150,000 pounds of the total PCBs). Clearly, EPA’s HRA of 1999 (US Environmental Protection Agency, 1999) and 2000 (US Environmental Protection Agency, 2000a, 2000b) for Hudson River dredging therefore excluded approximately one-third of the total PCBs from the PCB inventory. This was done notwithstanding that the scope of the Hudson River HRA included the airborne risks, not just fish consumption risks, that might be posed by PCBs resuspended and mobilized by dredging. This exclusion, however, did not stop EPA from taking credit for the extra 50,000 pounds of PCBs assumed to be accounted for by the monochlorinated and dichlorinated PCBs to augment the acceptability of its dredging plan in the face of criticism in 2001.

The EPA actions described above highlight three issues relating to potential bias in the scientific analysis:

1. whether EPA accurately inventoried the amount of PCBs that might pose risks to health;

2. whether EPA accurately assessed risks potentially posed by PCBs in its PCB inventory (addressed in greater detail later); and

3. whether the PCB risks quantified in the HRA corresponded to the PCB amounts that would be dredged

and subject to mobilization, with the potential to pose health risks.

The findings indicate that EPA based its risk estimates on a smaller pool of PCBs; they indicate further that this was done in part by excluding monochlorinated and dichlorinated PCB congeners from the HRA. The EPA did this, notwithstanding that the excluded congeners would necessarily be included in sediments that would be dredged and therefore would contribute to airborne PCB concentrations and health risks that might be posed to people situated near the river. In short, EPA’s modeled estimate of PCB residue load contributing to potential PCB inhalation risks failed to include important potential sources of PCBs and therefore is unreliable for predicting dynamics in the Hudson River if dredging of PCB-bearing sediments at hotspots is indeed undertaken.

Phases of PCBs to be Included in the Analysis

All phases should be included, most notably PCBs that are adsorbed onto particles, molecular PCBs that are dissolved, and particulate PCBs that are colloidal. All PCBs in the HRA, however, were assumed to settle under Stokes’

Bias in the EPA’s HRA Regarding PCBs in the Hudson River 101

Law for spherical silt particles. This assumption constitutes a continuous process of removal of PCBs from the water column, notwithstanding that molecular and dissolved PCB phases would remain, because they do not settle. That is, these waterborne PCBs are subject to becoming airborne, but this is not accounted for in EPA’s HRA.

The mechanical action of dredging hotspots will cause PCBs that are adsorbed to silt particles to enter the water column. Whereas much, if not most, of the PCB in the water column will remain adsorbed to silt, a significant, possibly majority fraction will enter the water column in a dissolved (molecular) or a colloidal phase (consisting of microscopic PCB droplets). Exclusion of PCBs in these dissolved and colloidal phases from the revised Hudson River HRA is reported in Appendix E, Section 5.2, titled “TSS Plume Estimates.” In that section, only silt particles were used to estimate settling rates:

Since data on settling rates were not available, a median value for settling velocity of 1.9 X 1074 M/sec [16.5 M/d] was used in the transport calculations. (US Environmental Protection Agency, 2000b)

The above description of settling velocity as a “median value” suggests misleadingly that settling was calculated for a heterogeneous distribution of particles whose median settling velocity is 1.9 X 10-4 M/sec [16.5 M/d]. In fact, only the “median” value was used. This uniform settling velocity, corresponding to a 20-micron (uM) sphere, excludes dissolved and colloidal PCBs, which are smaller. Dissolved PCBs (bound to water) and colloidal PCBs (subject to Brownian motion and water turbulence) never settle. This unstated simplification overestimates the rate of PCB removal from the modeled water column by assuming that all waterborne PCBs are adsorbed to particles that settle at the assumed velocity. Actually, a significant, if not predominant, fraction of total waterborne (resuspended) PCBs will consist of free PCBs present in dissolved and colloidal phases.

Inasmuch as silt has a specific gravity of about 2.5, the assumed “median” settling velocity corresponds to (spherical) particles of diameter exceeding 20 uM, whereas Stokes’ Law ceases to apply when the settling particles are fines that are less than about 50 uM. The EPA's implicitly assumed particle size therefore, also implicitly, assumes that the vastly more numerous PCB molecules in dissolved and colloidal phases will settle at the median rate. Colloidal PCBs are commonly recognized as being 1 uM and smaller and, of course, individual PCB molecules are smaller still. These PCB molecules and colloids also would suspend in

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the water phase even beyond the dredge site perimeter of perhaps 20 M. Molecular and colloidal PCBs can remain in the water, suspended as globules of pure PCBs that are smaller than 20 uM, without being captured by silt curtains and without settling at all:

PCB in colloidal form constitutes the most mobile form of PCB in water, being affected only minimally by settling, physical retention or adsorption. Concentrations of PCB-like compounds in water can be much higher in colloidal form than in suspended solids or in dissolved form, and can be much more difficult to intercept through physico-chemical means. (Paquin, 2001, p. 2)

Indeed, molecular and colloidal phases of PCBs together reasonably may be expected to constitute a significant, possibly the predominant, fraction of total PCBs in the water column, as illustrated by Table 1. Table 1 shows a site at which dissolved and colloidal PCBs together amounted to 54% of the total waterborne PCBs.

An EPA review of experience of dredging PCBs shows that dredging hotspots can disperse waterborne PCBs beyond a 20-meter envelope (“silt curtain”) around a dredge site, with observed concentrations of 0.1 to 0.2 ppm (100 to 200 ug/L, or 100,000 to 200,000 ng/L). This is approximately 3,000 to 6,000 times the PCB concentration assumed under a non-dredging scenario in the HRA prepared in support of another project (specifically, the PSEG Power New York proposal to site the Bethlehem Energy Center gas-fired power plant on the Hudson River at Bethlehem, New York; see Oko and Oko, 2001; PSEG Power New York, 2001). In this higher waterborne PCB concentration range, resulting airborne PCB concentrations were reported to have exceeded safe concentrations. Indeed, EPA’s HRA Appendix E states the following:

Table 1. Breakdown of forms under which PCB contamination is associated in groundwater at a Smithville, Ontario, Canada, site during the period 1994 to 2001; data compiled from 55 sampling campaigns

Concentration of PCBs in groundwater (ug/L)

Form present Range Average Proportion (%) suspended. 0-119 7.7 46 colloidal 0.4-19 6.0 36 dissolved 0.2-8 3.0 18 Total 1-129 16.8 100

Source: Paquin, 2001.

While these estimates of total trit+ PCB congener concentrations represent cumulative concentrations, dissolved or particulate trit+ PCB congener concentrations may be of even greater interest. In particular, the dissolved water column concentrations tend to be of greater concern because of their increased bioavailability. (US Environmental Protection Agency, 2000b, p. 59; emphasis added)

In short, EPA’s modeled estimate of PCB residue load contributing to potential PCB inhalation risks failed to include important sources of PCBs in water and therefore is unreliable for predicting dynamics in the Hudson River if dredging of PCB-bearing sediments at hotspots is indeed undertaken.

Precipitation of PCB-Bearing Sediment Particles from the Water Column

Precipitation rates should be quantified realistically, because they in turn quantify the rate of removal from the water column of PCBs that have been resuspended and mobilized by dredging. Instead, the residence time of flat, PCB-bearing clay particles in river water was quantified unrealistically, based upon the more rapid precipitation of spherically shaped particles acting in accordance with Stokes’ Law (Figure 2). This procedure underestimated waterborne PCBs and thereby also underestimated the amount of PCBs that would become airborne.

Mathematical treatment is simplified when a spherical shape for fine particulates is assumed, which is the case in Stokes’ Law. This assumption, however, predicts faster than natural settling rates because, in nature, spherical particles are rare. Disks, rod shapes, and irregular random shapes are more common and these shapes settle more slowly than

Spherical sediment particles settle directly in accordance with Stokes’

Flat clay particles oscillate; they have longer path length, and residence time:

Figure 2. Settlement of waterborne particles to a river bottom: path length and settling rate of spherical versus flat particles.

spheres. Mathematical predictions of settling rates that do not account for irregular shapes can predict a 100% faster settling rate at the >20-uM particle size range and more than 1,000% faster at the <10-uM size range.

Clay is abundant in the Hudson River region and would constitute a significant, if not the preponderant, fraction of PCB-contaminated sediment particles that will be resuspended and mobilized during dredging. Flat clay particles settle via a side-to-side oscillation during descent, greatly increasing their path length and residence time in the water column; that is why they settle more slowly than as predicted by Stokes’ Law. Such delay in exiting the water column reasonably would be expected to increase the concentration of PCB-laden particles in the water column markedly, much as delays at highway exits markedly increase traffic on the highway. In short, EPA’s modeled estimate of the suspended silt cleansing rate failed to include important properties of PCBs bound to sediments and therefore is unreliable for predicting dynamics in the Hudson River if dredging of PCB-bearing sediments at hotspots is indeed undertaken.

Electrostatic Charges on PCB-Bearing Sediment Particles in the Water Column

Clay sediment particles resuspended in water (as by dredging) tend to exhibit negative surface charges. Such particles are maintained in suspension by electrostatic interaction of the negative surface charges with cations (positive ions) in the water column. This electrostatic charge configuration inhibits agglomeration of fine silt particles resuspended by dredging. Electrostatic charges should be accounted for because of their potential importance in inhibiting settling of clay particles and removal of adsorbed PCBs from the water column of the Hudson River at dredging sites.

Electrostatic charges should be modeled, but instead they were ignored. By this omission, EPA fails to account for prolonged suspension in the water column of chargeseparated PCB-bearing clay particles; it thereby also underestimates waterborne PCBs subject to becoming airborne. Most fine particles, in part because of their high surfacearea-to-volume ratio, tend to become electrostatically charged in water (Figure 3). Again, clay sediment particles resuspended in water tend to exhibit negative surface charges. The similar charges cause the particles bearing them to repel one another. The space between charge-separated negatively charged particles then is filled with cations (positive ions) already present in the water column. This configuration of charge separation increases particle residence

Bias in the EPA’s HRA Regarding PCBs in the Hudson River 103

Figure 3. Charge separation of particles suspended in water. (Source: Historically Black Colleges & Universities/Minority Institutions, 2007.)

times in the water column. Some charge-separated particles will not settle at all. Electrostatically separated PCBbearing particles that do not settle remain in the water column, from which they are more available than settling particles to enter the atmosphere, where they may pose airborne risks.

By excluding this potentially significant factor from the analysis of settling of suspended particles in the Hudson River water column, EPA overestimates the settling velocity of PCB-laden particles to the river bottom and thereby underestimates the likely concentration of PCBs in the water. In short, EPA’s modeled estimate of suspended silt cleansing rate failed to include important properties of clay particles bearing PCBs and is therefore unreliable for predicting dynamics in the Hudson River if dredging of PCBbearing sediments at hotspots is indeed undertaken.

Reflection Coefficient of Precipitating PCB-Bearing Sediment Particles

The reflection coefficient should be quantified, because it constitutes a potentially significant source of return to the water column of PCB-bearing silt particles of relatively low mass. If 20% of low-mass particles encountering the substrate are swept by currents back into the water column, then EPA’s underestimation of the suspended particle population in the water column, arising from omitting a reflection coefficient, would be 20%. We don’t know what (if

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any) single value of the reflection coefficient should be assumed for the Hudson River or what multiple values might be assumed at each location in the river, under varying flow conditions. Clearly, however, EPA incorporated no reflection coefficient at all (or, equivalently, a reflection coefficient of zero was incorporated) in calculating PCB removal rates from the water column. This procedure thereby underestimated waterborne PCBs subject to becoming airborne.

The rate of free settling in water of silt particles influenced by earth’s gravity can be predicted from particle size and the specific gravity of discrete particles. At the bottom of settling columns where the particles compact, however, other mechanisms take over. One of these processes is reflection (Shavit, Moltchanov, and Agnon, 2003), which refers to the fact that particles of low mass may bounce off the substrate on which they land. The mass of particles that might be swept back into the water column after settling to the substrate would be expected to be greater in flowing waters, such as in the Hudson River and in laboratory wave chambers (Shavit, Moltchanov, and Agnon, 2003).

Similarly, colloids may remain in suspension indefinitely as a result of bouncing off water molecules with which they collide (a well-documented phenomenon termed Brownian motion). The phenomena of reflection and bounce occur in a zone of activity termed the “hindered zone” of settling. Failure to incorporate a reflection coefficient when calculating settling of PCB-laden particles in the Hudson River water column tends to underestimate particle and PCB concentrations in the water, just as traffic could be underestimated on a highway if the model used fails to count a high fraction of exiting vehicles that immediately reenter the highway. In short, EPA’s modeled estimate of suspended silt cleansing rate failed to incorporate a reflection coefficient and is therefore unreliable for predicting dynamics in the Hudson River if dredging of PCB-bearing sediments at hotspots is indeed undertaken.

PCB Codistillation

Empirical measurements should be used to validate model assumptions made in quantifying PCB entry into the air. Instead, available empirical measurements were diluted with modeled values (see below), thereby underestimating the water-to-air transfer coefficient. Accurate estimation of waterborne PCB entry into the air requires quantification via accounting for PCB codistillation. By ignoring PCB codistillation in quantifying the water-to-air PCB transfer coefficient, EPA underestimated waterborne PCBs subject

to becoming airborne. A recent news item (Anonymous, 2001) based upon research conducted by the Integrated Atmospheric Deposition Network (2000) reveals that codistillation has transferred nearly two tons of PCBs from Lake Ontario to the atmosphere between 1992 and 1996. According to a news report describing this startling finding,

The Great Lakes have begun to “exhale” significant quantities of chemicals, including ... PCBs ... , releasing them into the atmosphere. ... Researchers say ... the lakes begin naturally cleansing themselves through the volatilization process (i.e., evaporating pollution off the water surface). The latest figures from the Integrated Atmospheric Deposition Network (IADN) show a net release from Lake Ontario alone of almost two tons of PCBs into the air ... from 1992 through 1996. .. . (Anonymous, 2001, p. 9; emphasis added)

That’s a half ton (nearly 500 kg) of PCBs each year codistilling from the surface of a cold lake. Codistillation, however, also is temperature dependent. Thus it would occur at a greater rate, and to a greater degree, in warm water, such as in Hudson River water heated during industrial use as a cooling fluid, then itself cooled in cooling towers before return to the river. The EPA’s failure to account for codistillation might be explained by unfamiliarity with the phenomenon, as well as by an unwillingness to give appropriate credence to empirical data arising from credible reports. In short, EPA’s modeled estimate of assumed water-to-air PCB transfer rate failed to include consideration of codistillation and is therefore unreliable for predicting dynamics in the Hudson River if dredging of PCB-bearing sediments at hotspots is indeed undertaken.

Empirical Measurement of Airborne PCBs over PCB-Contaminated Waters

The degree to which EPA was familiar with PCB codistillation cannot be inferred with certainty. Such familiarity, however, should have been unnecessary for enabling EPA to quantify accurately PCB water-to-air transfer coefficients, inasmuch as empirical measurements cited by EPA had been made to quantify them. Indeed, the revised Hudson River HRA (US Environmental Protection Agency, 2000a, 2000b), Appendix B, cites nine empirical measurements of airborne PCB concentrations (Buckley and Tofflemire, 1983) contributing toward estimating the transfer coefficient of PCBs from water to air (US Environmental Protection Agency, 2000b; see EPA’s Table B-1). These and possibly other measurements were used by EPA to produce PCB water-to-air transfer coefficients (as summarized in this article’s Table 2; also see EPA’s Table B-2 and the original data source, Harza Engineering Co., 1992):

These data can be used to estimate an empirical water to air transfer coefficient, representing the ratio of the PCB concentration in air divided by the PCB concentration in water. Using the detected PCB concentrations in air and water summarized in Table B-2, empirical air-water transfer coefficients range from 0.02 to 0.4 ug/M? per ug/L, with a median value of 0.09, and an average value of 0.15 (ug/M? per ug/L). (US Environmental Protection Agency 2000A, p. 18)

The EPA expressed surprise about the magnitude of these measured values, however, possibly because EPA was unfamiliar with codistillation. In that case, EPA would have expected the transfer coefficients to be lower than those

Table 2. The US Environmental Protection Agency’s Health Risk Assessment: modeled versus measured airborne PCB concentrations

Measured airborne PCB concentrations at 1-meter altitude

Empirical water-to-air transfer coefficient

range range median mean from to from to (ug/M?) (ug/M3 per ug/L) 0.033 0.53 0.02 0.4 0.09 0.15 Airborne PCB concentrations resulting from water-to-air transfer measured range modeled range measured/modeled from to from to from to (ug/M?) (ug/M?) se se 0.033 0.53 0.00012 0.00021 157 4,417

(assumes PCB flux = 13 ug/s)

Source: US Environmental Protection Agency, 2000a, 2000b.

Bias in the EPA’s HRA Regarding PCBs in the Hudson River 105

suggested by the measurements. Further investigation could have elucidated the explanation for the higher-thanexpected PCB water-to-air transfer coefficients, but further investigation apparently was not undertaken.

Instead, the measured values described above were assigned a low weighting. This EPA accomplished via adulteration of the nine empirically derived transfer coefficients with two lower transfer coefficients derived via two modeling approaches (Table 2). The two modeling approaches ignore codistillation, instead producing transfer coefficients consistent with Henry’s Law acting on bulk PCB concentrations, that is, assuming even distribution of PCBs throughout water. Model results expressed in units of ng/M? sec per ng/L could not be compared directly with the empirical values expressed in ug/M? per ug/L. The units were brought into line, and the comparison made, via use of the average PCB concentration in the river (24 ng/L = 0.024 ug/L; US Environmental Protection Agency, 20002, p. 18). The EPA used this concentration to produce a flux (13 ug/sec; US Environmental Protection Agency, 20002, p. 19) which, using the median empirical transfer coefficient (0.09), generated a modeled airborne concentration of 0.00012 to 0.00021 ug/M3 (US Environmental Protection Agency, 2000a, p. 20), compared with 0.033 to 0.53 ug/M3 detected empirically (US Environmental Protection Agency, 2000a, p. 20). This corresponds to a factor of a 157 to 4,400 difference between the modeled versus empirical data (0.53/0.00012 = 4,417; 0.033/0.00021 = 157). That is, the modeled water-to-air transport factors downwardly biased the estimated transfer of PCBs from Hudson River water to the atmosphere by a factor ranging from as little as 1/4,400th to 1/157th of the empirically determined values.

The EPA’s preference for modeled transfer coefficient values biased the expected concentration of airborne PCBs over

the river surface in a direction favorable to EPA’s dredging proposal and, in this sense, this action was self-serving. It was sufficiently self-serving to reduce airborne PCB estimates to below levels of concern to EPA and below levels of concern to the New York State Department of Environmental Conservation. Specifically, EPA’s weighting procedure diminished assumed airborne PCB concentrations from above published de minimis levels, requiring quantitative risk assessment, to concentrations below de minimis levels, not requiring quantitative assessment of risks potentially posed by inhalation of mobilized PCBs that might become airborne as a result of dredging (Table 3). Contrary to EPA's routine procedure of validating its air models against reality via use of dyes or other markers, in this case EPA effectively invalidated empirical data based upon real-world data failing to conform to EPA’s air model. In short, EPA’s modeled estimate of the water-to-air PCB transfer rate failed to incorporate empirical evidence about water-to-air transfer of PCBs and is therefore unreliable for predicting dynamics in the Hudson River if dredging of PCB-bearing sediments at hotspots is indeed undertaken.

Warm Water Sources of Hudson River PCB Entry into the Atmosphere

Potential warm water sources of Hudson River PCB entry into the atmosphere, such as cooling towers, must be accounted for in assessing the potential public health significance of airborne PCBs under any dredging scenario. Instead, PCB concentrations resulting from water-to-air transfer were estimated based upon unheated (relatively cold) river water. According to the revised HRA for the Upper Hudson and Mid-Hudson River (US Environmental Protection Agency, 2000a):

The concentrations of PCBs in air were calculated from a combination of historical monitoring data and modeled emissions from the river. . . . (US Environmental Protection Agency, 2000a, p. ES-4; emphasis added)

Table 3. Regulatory effect of adjusting PCB concentrations measured in air via incorporation of lower, modeled concentrations

New York State Department of Environmental Conservation DAR-1* de minimis

Measured PCB range

concentration for PCB

Modeled PCB range

from to (ug/M*) 0.033 0.53

(ug/M*)

from to (ug/M?) 0.00012 0.00021

*Source: New York State Department of Environmental Conservation, 1997.

106 Environmental Practice 9 (2) June 2007

The water temperature in cooling towers may be elevated to approximately 100° F (56° C) above that of the ambient river water source.

For every 10° C rise in temperature, the rate of a physical reaction, such as the rate of PCB codistillation, may be expected roughly to double. The rate of PCB transfer from water to air occurring with a 40° C water temperature increase, accordingly, would be expected to undergo four doublings. Thus, the rate at which PCBs in cooling tower water might be expected to escape to the air from water at a temperature of, say, 45° C (113° F) in a cooling tower would be approximately 16 times greater than that in a source of Hudson River water at a temperature of 5° C (41° F).

If dissolved and/or colloidal PCBs rise to 10 ug/L (parts per billion by weight) during dredging, the weight of PCBs entering the cooling tower under one project proposal (the Bethlehem Energy Center power plant; see Oko and Oko, 2001; see PSEG Power New York, 2001), based on a 4,500 gallon/minute uptake, would be 0.25 kg/d (approximately 0.1 tons/year). Examination of studies forming the basis for the passage quoted above pertaining to transfer of PCBs from river water to air, however, reveal no studies addressing PCB release from warm water in cooling towers. In short, EPA’s modeled estimate of water-to-air PCB transfer rate failed to incorporate consideration of transfer from heated water and is therefore unreliable for predicting dynamics in the Hudson River if dredging of PCB-bearing sediments at hotspots is indeed undertaken.

Summary of EPA Quantification of Parameters Used in Dredging Decision Making

As documented above, EPA evaluation of the nine subject parameters addressed in this study systematically has underestimated concentrations of PCBs that could, and presumably would, become airborne under non-dredging and dredging scenarios. Adoption of simplifying assumptions in modeling river flow, precipitation of suspended particles, and PCB dynamics can result in omission and/or unreliable quantification of important parameters contributing to overall PCB-associated risk. That this indeed has occurred is hinted at in Section 5 (“Assessment of Water Quality Impacts”) of Appendix E of EPA’s revised HRA for the Hudson River (US Environmental Protection Agency, 2000b):

A complete evaluation of water quality impacts requires integrating a calibrated hydrodynamic model of the system with a water quality model capable of predicting changes due to

advection, turbulent diffusion, and settling of the suspended particles. Such a model is beyond the scope of this evaluation. (US Environmental Protection Agency, 2000b, Section 5, p. 12; emphasis added)

Discussion and Conclusions

Statistical Significance

A parameter that is estimated inaccurately must be overestimated or underestimated; otherwise it is estimated accurately. If these two alternative directions of misestimation are equally probable, as they should be, then occurrence of each is associated with an expected probability of 0.5 (50%, or “fifty-fifty”). If the parameters also are independent (under- or overestimating one does not cause mis-estimation of another), then any two randomly selected parameters that are mis-estimated would have a 0.25 probability of being mis-estimated in a direction more permissive to dredging and, likewise, 0.25 would be the probability of the same two parameters being misestimated in a direction less permissive to dredging; 0.50 [1.0 — (0.25 + 0.25)] would be the probability of one mis-estimation being in the dredging-permissive direction and the other in the dredging-prohibitive direction. The confluence of fully nine parameters linked in a single direction, as reported above in the “Findings” section, would be associated with a vanishingly small probability of occurring by chance alone—o.5°, which is 0.002. Qualitatively speaking, a low probability (for example, below the usual 0.05 scientific confidence level) supports the conclusion that bias (possibly unintentional), rather than chance alone, influenced EPA’s analysis consistently in the direction of underestimating PCB risks in the baseline HRA for the Hudson River.

Significance for Health Risk Assessment

The findings reported above suggest that potential inhalation risks that should have been quantified in the EPA’s HRA were not quantified. The EPA’s HRA states the

following:

Risks and hazards through inhalation of volatilized PCBs were not assessed in the Mid-Hudson HHRA because calculated risks for this pathway were shown to be de minimis (insignificant) in the Human Health Risk Assessment for the Upper Hudson River. Given that concentrations of PCBs found in the sediment and river water in the Mid-Hudson are lower than concentrations in the Upper Hudson, the risks from volatilization also would be expected to be insignificant (and

Bias in the EPA’s HRA Regarding PCBs in the Hudson River 107

lower) in the Mid-Hudson. (US Environmental Protection Agency, 1999, p. ES-2)

This means that EPA’s estimate of airborne PCB concentrations is below the New York State Department of Environmental Conservation de minimis Annual Guideline Concentration (New York State Department of Environmental Conservation, 1997, 2003) which, if exceeded, would trigger a requirement to quantify inhalation risks potentially posed by airborne PCBs under a reasonable worstcase scenario. Accordingly, although the HRA “considered” airborne PCBs, risks to public health potentially posed by transfer of PCBs from Hudson River water to the air effectively were assessed as zero. Risks posed by PCBs entering the air from cooling towers (with or without dredging) were neither quantified nor considered. Other sources of airborne PCB risks that also were unquantified, according to EPA’s HRA, were “the contribution of PCBs in air from contaminated sediment and floodplain soil” (US Environmental Protection Agency, 1999, Section 2.3.4, p. 20).

Regulatory Significance

If EPA had accepted empirical measurements of PCB transfer from water to air, potential risks to people inhaling PCBs would have been required to be included in its HRA (Table 3). Even the lowest of the five empirical measurements of airborne PCB concentration generated by PCBs at specified concentrations in water (0.03 ug/ M3) exceeded the New York State Department of Environmental Conservation’s published Annual Guideline Concentration value for airborne PCBs of 0.002 ug/M3 by a factor of 15-fold. The EPA’s use of the mean (0.15 ug/M3?) or the median (0.09 ug/M®) of all five empirically measured airborne PCB concentrations would, of course, exceed these critical benchmarks even more dramatically. Most notably, the measured range of airborne PCB concentrations (0.033 to 0.53 ug/M3) reported by EPA exceeded by a factor of five-fold the New York State Department of Environmental Conservation’s de minimis value of 0.1 ug/M3 that would have triggered inclusion of PCB inhalation as an exposure pathway to be quantified in the HRA. The EPA’s procedures, therefore, undermined public health protection by eroding safety and/or the margin of safety that should be built into EPA standards of public health protection.

The EPA understatement of PCB release to air affects other projects besides the Hudson River dredging project. The New York State Department of Environmental Conservation, for example, need not account for PCB emissions

108 Environmental Practice 9 (2) June 2007

from cooling towers in approving permit applications for projects (such as power plants), even if those projects will use cooling towers. Indeed, citizen criticism of EPA’s Environmental Impact Statement value in the New York State Department of Environmental Conservation’s permit review of project proposals has been rejected, not on technical grounds, but because the EPA values previously had undergone peer review. As a result, HRAs prepared by project applicants may ‘account’ for public health risks potentially posed by waterborne PCBs becoming airborne simply by quantifying them as zero, based upon the erroneous and apparently unreviewable assumption that PCB emissions from water to air will be de minimis. The potential significance is exemplified by the permit proceedings for the Bethlehem Energy Center gas-fired power plant on the Hudson River (Oko and Oko, 2001; PSEG Power New York, 2001), in which the applicant was exempted from quantifying risks potentially posed by airborne PCBs on the authority of the EPA’ HRA for the Mid-Hudson River (US Environmental Protection Agency, 1999, 2000, 2000b).

Significance to Hudson River Communities

The most valuable reward for doing river restoration projects is that a river is in some sense “fixed.” Although this reward would have to be especially large for the Hudson River to justify the enormous price of “fixing” it, the reality seems different. Whereas sediments and water should be cleaned, EPA’s dredging program cleans only PCB hotspots, leaving PCBs in sediments, biota, and water elsewhere in the river, and also leaving virtually all non-PCB contaminants in sediments, biota, and water, even after dredging is completed. Indeed, EPA’s dredging proposal addresses 150,000 pounds (68,000 kg) of sediment-borne PCBs compared with 1.3 million pounds (591,000 kg) that GE concedes it discharged into the Hudson from two capacitor plants. That amounts to less than 12% of known PCBs and an even smaller fraction of the total PCBs discharged into the Hudson River.

Whereas sport fisheries should be uncontaminated and game fish caught in the river safe to consume, in fact the fish cannot become edible in the reasonably foreseeable future. Even if every PCB molecule could be removed from the river, all other Hudson River pollutants will survive PCB hotspot dredging, including persistent chlorinated hydrocarbon pesticides, polycyclic aromatic hydrocarbons (PAHs), and heavy metals such as cadmium, copper, lead, mercury, and zinc (New York State Department of Environmental Conservation, 2000). Whereas air pollution aris-

ing from river water should become de minimis, in fact, mobilization of PCBs by dredging will increase PCB release to the air for years, and other pollutants also will become airborne after dredging is completed. Whereas the incidence of adverse health effects that might be caused by airborne PCBs should become de minimis, in fact, such health effects (if really caused by PCBs) might increase for years before they begin to diminish after dredging.

With or without dredging, purging PCBs from Hudson River sediments will require decades (Baker et al., 2001). At one extreme, the remaining PCBs might amount to only the 150,000 pounds to be dredged. In that case, about 90% already has been eliminated without dredging, and the river has cleansed itself of a major fraction of PCBs via processes that are ongoing; further self-cleansing would be expected. Realistically, cleansing has eliminated less than 90%, and multiples of 150,000 pounds must remain. In that case, if dredging occurs, a preponderance of PCBs still would remain after 150,000 pounds is removed. Ultimately, the Hudson River must cleanse itself, with or without dredging.

Some people see light at the end of the tunnel, when dredging will reduce PCBs in sediment, biota, water, and air, and reduce PCB-associated human disease to de minimis incidence. Others see light at the end of a different, longer tunnel, when continued natural burial by sediment loading from runoff into the river likewise will sever the connection of sediment-borne PCBs to the water, biota, and air, reducing PCB-associated human disease to de minimis incidence. Continued natural dechlorination of buried PCBs and further degradation via physical, chemical, and biological processes acting beneath the sediments eventually will finish the job, with or without dredging.

The dredging argument has focused narrowly on the two tunnels described above leading to de minimis PCB levels and whether shortening one via dredging is justified despite near-term environmental disruption. Even objective scientists cannot resolve subjective issues associated with deciding which tunnel constitutes the better route to essentially the same destination. Objective science, however, remains essential. Given the evident biases identified in this article’s “Findings,” objective consideration of at least three issue areas is needed:

1. Are PCBs harming health and, if so, are effects sufficiently serious, and risks sufficiently high, to justify urgent PCB removal?

2. If PCBs are harming human health in Hudson River communities, will dredging exacerbate harm by further mobilizing sediment-borne PCBs? If PCB-mediated health effects are unacceptable now, will their prolonged exacerbation by dredging be more unacceptable? Additional measures to protect populations would have to be contemplated—short of evacuation, but expensive. Conversely, if PCB health risks are acceptable, why dredge to remove PCBs when natural processes eventually will remove them anyway?

3. If the benefits of eliminating PCBs from hotspots are deemed worth the enormous price in a hypothetical, otherwise clean Hudson River, are they also worth the price in the actual Hudson River, which has pollutants other than PCBs, and PCBs in places other than in the hotspots where dredging will occur? Lost in the dredging debate seems to be the big picture: a dredged river polluted as before, but with at best a 12% decrease in PCB in its sediments. Is narrowly focusing on dredging hotspot PCB justified, if the river will remain toxic with other pollutants and with non-hotspot PCBs?

In light of these questions, the near-term price of dredging must include potential ecological and public health impacts. The findings and considerations addressed above justify three specific conclusions and one general conclusion. First, risks to public health potentially posed by inhalation of PCBs were not modeled correctly (effectively quantified as zero) and therefore would be ignored in a dredging-specific HRA if only the baseline HRA exposure routes and pathways are included for comparison. Second, even if all PCBs could be removed from the river or from hotspots, all other Hudson River pollutants would remain. Their continued presence after dredging would continue to limit recreational and commercial river use for many decades; for example, they still would limit consumption of fish, especially in pregnant women, young children, and other sensitive subpopulations. Third, PCB inhalation risks and their acceptability were unassessed and remain unknown, as is the degree to which dredging would exacerbate them and for how long. Finally, EPA’s ultimate decision to dredge or not dredge will depend upon subjective issues whose resolution must be informed by objective science to answer the above questions, and others, credibly.

Note

1. One of us (Michaels) previously consulted to GE under the auspices of RAM TRAC Corporation, but neither Michaels nor RAM TRAC has done

Bias in the EPA’s HRA Regarding PCBs in the Hudson River 109

so for over five years. Neither author nor corporation has a business relationship with GE or financial interest in the dredging issue.

References

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Anonymous. 2001. Great Lakes Show Signs of Exhaling Contaminants. EM Magazine, Air & Waste Management Association, December, p. 9.

Baibergenova, A., R. Kudyakov, M. Zdeb, and D. O. Carpenter. 2003. Low Birth Weight and Residential Proximity to PCB-Contaminated Waste Sites. Environmental Health Perspectives 111:1352-1357.

Baker, J. E., W. F. Bohlen, R. Bopp, B. Brownawell, T. K. Collier, K. J. Farley, W. R. Geyer, and R. Nairn. 2001. PCBs in the Upper Hudson River: The Science behind the Dredging Controversy. White paper prepared for the Hudson River Foundation, 47 pp. Also available at http://www. seagrant.sunysb.edu/HEP/archive/hrfpcb102901.pdf.

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Cappiello, D. 2001. New EPA Plan Dredges More PCBs: Agency Raises Estimate by 50 Percent on New Data from GE. Times Union Newspaper, Albany, NY, December 6, p. Bs.

Carpenter, D. O. 1998. Polychlorinated Biphenyls and Human Health. International Journal of Occupational Medicine and Environmental Health 11:291-303.

Carpenter, D. O. 2005. Hospitalization Rates for Coronary Heart Disease in Relation to Residence near Areas Contaminated with Persistent Organic Pollutants and Other Pollutants. Environmental Health Perspectives 113 (6):756-761.

Carpenter, D. O.; T. Nguyen, L. Le, A. Baibergenova, and R. Kudyakov. 2003. Profile of Health Effects Related to Proximity to PCB-Contaminated Hazardous Waste Sites in New York. Fresenius Environmental Bulletin 12:173-180.

Chase, K. H3 O. Wong, D. Thomas, B. W. Berney, and R. K. Simon. 1982. Clinical and Metabolic Abnormalities Associated with Occupational Exposure to Polychlorinated Biphenyls (PCBs). Journal of Occupational Medicine 24(2):109-114.

Choi, W., S. Y. Eum, Y. W. Lee, B. Hennig, L. W. Robertson, and M. Toborek. 2003. PCB 104-Induced Proinflammatory Reactions in Human Vascular Endothelial Cells: Relationship to Cancer Metastasis and Atherogenesis. Toxicological Science 75:47-56.

Harza Engineering Co. 1992. Fort Edward Dam PCB Remnant Deposit Containment Environmental Monitoring Program: Report of 1991 Results. Harza Engineering Company, Chicago, IL.

Hennig, B., B. D. Hammock, R. Slim, M. Toborek, V. Saraswathi, and L. W. Robertson. 2002. PCB-Induced Oxidative Stress in Endothelial Cells:

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Modulation by Nutrients. International Journal of Hygiene and Environmental Health 205:95—-102.

Historically Black Colleges & Universities/Minority Institutions. 2007. Environmental Technology Consortium at Clark Atlanta University and Northern Arizona University. http://jan.ucc.nau.edu/doetqp/courses/ env44o/env44o_2/lectures/lecig/lecig.html.

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New York State Department of Environmental Conservation. 2000. Hudson River Sediment and Biological Survey. New York State Department of Environmental Conservation, Division of Water, Albany, NY, 19 pp. Also available at http://www.dec.state.ny.us/website/dow/bwam/hrsb2000.pdf.

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Oko, U., and C. Oko. 2001. Dr. Oko’s Petition for Full Party Status— Response to PSEG, in the Matter of the Application of PSEG Power New York, Inc. for a State Pollution Discharge Elimination System Permit, State Air Facilities Permit and PSD Permit. Petition by Uriel M. Oko and Carol Oko with consulting assistance from Robert Michaels, RAM TRAC Corporation, December 18, 12 pp.

Paquin, J. 2001. Insights into the Origin, Movement, and Capture of PCB DNAPL Contamination at the Smithville Site [Ontario, Canada]. Proceedings of the Fractured Rock 2001 International Conference, 10 pp., March 25-28.

PSEG Power New York. 2001. Multipathway Risk Assessment for Bethlehem Energy Center Project. ENSR Corporation, Acton, MA, June.

Shavit, U., S. Moltchanov, and Y. Agnon. 2003. Particles Resuspension in Waves Using Visualization and PIV Measurements: Coherence and Intermittency. International Journal of Multiphase Flow 29(7):1183-1192.

Slim, R., M. Toborek, L. W. Robertson, and B. Hennig. 1999. Antioxidant Protection against PCB-Mediated Endothelial Cell Activation. Toxicological Science 52:232-239.

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Taylor, P. R., J. M. Stelma, and C. E. Lawrence. 1989. The Relation of Polychlorinated Biphenyls to Birth Weight and Gestational Age in the Offspring of Occupationally Exposed Mothers. American Journal of Epidemiology 129:395-406.

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PCBs Reassessment FS. TAMS Consultants, Bloomfield, NJ, 30 pp. plus appendices.

US Environmental Protection Agency. 2000a. Revised HRA, Mid- and Upper Hudson River, Phase 2 Report—Further Site Characterization and Analysis. Volume 2F—A Human Health Risk Assessment, Hudson River PCBs Reassessment FS. TAMS Consultants, Bloomfield, NJ, 128 pp. plus appendices.

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Associated with Dredging Activities. Hudson River PCBs Reassessment FS. TAMS Consultants, Bloomfield, NJ, pp. 33-67.

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Submitted May 16, 2006; revised April 18, 2007; accepted April 24, 2007.

Bias in the EPA’s HRA Regarding PCBs in the Hudson River 111

Appendix 2

Michaels, Robert A.; and Uriel M. Oko. Hudson River PCB Dredging: midcourse assessment

and implications regarding possible project continuation. Environmental Practice

(Cambridge University Press), 9:377-94, 2010

ENVIRONMENTAL REVIEWS & CASE STUDIES

Hudson River PCB Dredging: Midcourse Assessment and Implications Regarding Possible Project Continuation Versus Termination

Robert A. Michaels, Uriel M. Oko

Phase 1 of Hudson River dredging fractionally reduced the amount of polychlorinated biphenyl (PCB)-contaminated sediment remaining in the river bottom, but greatly increased its downstream transport, as “clamshell” dredge buckets leaked more material than they retained. Clamshells were especially inefficient at capturing liquid PCBs and PCBs adsorbed to silt and fine sediment. Material that was removed, therefore, was relatively coarse, and contained relatively little PCB. Volume reduction was achieved only at the expense of massive mobilization of liquid, colloidal, and adsorbed forms of PCB, spreading contamination to previously uncontaminated river areas. We estimate that Phase 1 increased the surface area of contaminated riverbed by at least 3 orders of magnitude, from about 50 dredged acres to many square miles. PCB entry into ecosystems, water, and air depends upon the surface area of contaminated sediment newly exposed to scouring from the riverbed, causing further downstream transport, especially in high-flow events over years or decades. Indeed, Phase | contravened EPA’s benefit criterion by mobilizing PCB at a higher rate than would occur naturally, without dredging, over the planned seven-year project duration. If dredging is to continue, therefore, Phase 2 must assure health risk acceptability and net benefit compared with no action/no dredging. Further, EPA’s benefit criterion must be revised to account for impacts of PCB mobilization to ecosystems and

air, not just resuspension to water. Finally, Phase 2 must

doi:10.1017/S1466046610000529

increase the scope and duration of environmental monitoring to enable more reliable warning of harm in real time, and project evaluation over decades. We recommend that EPA consider for Phase 2 such technologies as coffer damming, vacuum dredging, and dredging within enclosures to minimize sediment resuspension; mobilization of liquid, colloidal, and adsorbed forms of PCB; and PCB entry into ecosystems and air. If Phase 2 cannot assure health risk acceptability and comply with a revised benefit criterion, we recommend that EPA terminate the dredging project. Environmental Practice 12:377-394 (2010)

he General Electric Company (GE) has completed

Phase 1 of United States Environmental Protection Agency (US EPA)-mandated dredging of polychlorinated biphenyls (PCBs) from 27 selected hotspots along a 40-mile stretch of the Hudson River, starting near Fort Edward, New York (GE, 2010a,b; US EPA, 2010). The project, which may constitute the largest remedial action in the history of the Superfund Act of 1976 [Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)], is divided into two phases. It is to be implemented over seven years, with a cost estimated at nearly a billion US dollars. Phase 1 was started and completed in 2009 (year 1), though its objectives remain uncompleted. Year 2 (2010) is being spent evaluating Phase 1 and planning Phase 2, which encompasses a projected five-year period.

All parties agree that Phase 1 mobilized much PCB, significantly more than planned (GE, 2010a,b; US EPA, 2010a). PCB mobilization results in entry of mobilized PCB into ecosystems and environmental media, including the atmosphere, with consequential human exposure via all major routes: inhalation, ingestion, and dermal. Airborne PCB,

Affiliation of authors: Robert A. Michaels, PhD, CEP, President, RAM TRAC Corporation; Schenectady, New York. Uriel M. Oko, PhD, PE, President, Recycle Management, Glenmont, New York.

Address correspondence to: Robert A. Michaels, PhD, CEP, President, RAM TRAC Corporation, 3100 Rosendale Road, Schenectady, NY 12309; (phone) 518-785-0976; (e-mail) ram@ramtrac.com.

Hudson River PCB Dredging 377

like waterborne PCB, also may enter ecosystems (e.g., Buckley and Tofflemire, 1983). Planning for dredging Phase 2, therefore, must be informed by the reemerging issue of PCB toxicity to humans and other species.

Toxic effects exerted by PCB have been documented most extensively in animal studies, with probable significance for people. However, PCB effects on people also have been studied extensively [e.g., see Agency for Toxic Substances and Disease Registry (ATSDR), 2000; Baibergenova et al., 2003; Bertazzi et al., 1987; Carpenter, 1998, 2005; Carpenter et al., 2003, Chase et al., 1982; Choi et al., 2003; Colombi et al., 1982; Emmett, 1985; Emmett et al., 1988a,b; Fischbein, 1985; Fischbein and Wolff, 1987; Fischbein et al., 1979, 1982, 1985; Hennig et al., 2002; Kimbrough, Doemland, and LeVois, 1999a,b; Lawton, Ross, and Feingold, 1986; Lawton et al., 1985a,b; Lucier, 1991, Maroni et al., 1981a,b; Meigs, Albom, and Kartin, 1954; Slim et al., 1999; Smith et al., 1982; StehrGreen et al., 1986; Taylor, Stelma, and Lawrence, 1989], including many studies associated with adverse human health effects. Effects include higher incidence of low-birthweight infants among residents of zip codes of PCB disposal sites (Baibergenova et al., 2003) and, more recently, higher hospitalization rates for coronary heart disease in zip codes with PCB contamination (Carpenter, 2005). PCBs are classified as animal carcinogens and as probable human carcinogens (ATSDR, 2000).

Occupational studies suggest that PCB inhalation adversely affects the human respiratory system (Emmett, 1985; Emmett et al., 1988a,b; Fischbein et al., 1979; Lawton, Ross, and Feingold, 1986; Smith et al., 1982; Warshaw et al., 1979), though such studies have been unable to exclude reliably causation by other occupational toxins to which simultaneous or sequential exposure might have occurred (ATSDR, 2000). Occupational studies also have suggested other adverse health effects of PCB, including gastrointestinal, hepatic, and dermal effects (Alvares et al., 1977; Baker et al., 1980; Bertazzi et al., 1987; Chase et al., 1982; Colombi et al., 1982; Emmett, 1985; Emmett et al., 1988a,b; Fischbein, 1985, Fischbein et al., 1979, 1982, 1985; Kimbrough, Doemland, and LeVois, 1999a,b; Lawton, Ross, and Feingold, 1986; Lawton et al., 1985a,b; Maroni et al., 1981a,b; Meigs, Albom, and Kartin, 1954; Ouw, Simpson, and Siyali, 1976; Smith et al., 1982; Warshaw et al., 1979). Accordingly, as part of planning for the dredging project, GE was required to adhere to EPA-approved limits on PCB concentration in air and water.

Our assessment of Phase 1 implementation of the Hudson

River dredging project is informed by our findings that the project was justified by EPA based upon numerous errors,

378 Environmental Practice 12 (4) December 2010

all in the dredging-friendly direction, and our conclusion that these consistent errors amounted to pro-dredging bias on the part of EPA (Michaels and Oko, 2007). We evaluated EPA's baseline Hudson River health risk assessment (HRA) (US EPA, 1999, 2000a,b) and found it to be biased toward keeping PCBs in sediments that would be removed by dredging. The HRA did this by systematically misquantifying parameters, most essentially underestimating PCB movement from sediments to water and from water to air. EPA excluded from its analysis all monochlorinated and dichlorinated PCB congeners, which EPA subsequently estimated at about one third of total PCB mass in the river, and also excluded liquid PCB oils, dissolved and colloidal PCB, as well as PCB adsorbed to fine particles, such as clay and silt. GE Site Evaluation and Remediation Program Manager John G. Haggard on April 9, 2010, orally reported that half of the resuspended PCB in the dredging project was found to be dissolved; and half was in particulate form, which would include colloidal PCB. Consistent with this view, Paquin (2001) reported, “PCB in colloidal form constitutes the most mobile form of PCB in water, being affected only minimally by settling, physical retention or adsorption. Concentrations of PCB-like compounds in water can be much higher in colloidal form than in suspended solids or in dissolved form, and can be much more difficult to intercept through physico-chemical means” (p. 2). The dissolved and particulate phases of PCB measured in Hudson River dredging Phase 1 are quantified in Figure 5.3-14 of GE’s Phase 1 Evaluation Report (Figure 1 here), which shows them to be roughly equal. GE’s report states in the Key Findings section, “The PCB mass was mostly in dissolved form, although particulate phase PCBs were an important factor in resuspension” (GE, 2010b, p. 77).

EPA included silt-adsorbed PCB, but overestimated the rate at which it would settle out of the water column by inappropriately basing the settling rate on Stoke’s law. Stoke’s law applies to massive spherical particles that drop like marbles through a viscous medium. Flat clay particles settle more slowly with a longer path length and residence time than do spherical, or roughly spherical, particles. Dissolved and colloidal forms of PCB do not settle. None of these forms of PCB settle as Stoke’s law would predict.

EPA's baseline HRA omitted electrostatic charges on clay particles that separate them, preventing agglomeration and maintaining clay in suspension; EPA also assumed that particles never “reflect” back into the water column after settling, likewise underestimating PCB concentrations in water (Shavit et al., 2003). Also omitted was PCB codistillation, in which PCBs at low bulk concentrations in river

Particulate Phase

+1.2 Sandard Effor fo the Mean

Fevl Fev ev eve? vt

Aver: ight Percent 41 2 ad ea ie Mean 8 T sbosrrsesrifesersresitirrs

= o putiesitirees

123 4 5 6 Tf 8 8 10 Homolog

Figure 1. Comparison of average composition for dissolved and particulate PCBs downstream of the Hudson River Phase 1

dredging area. Source: GE (2010b).

water preferentially distribute to the air-water interface, greatly accelerating PCB transfer from water to air (Harza, 1992; Integrated Atmospheric Deposition Network, 2000). EPA cited its own empirical data showing more rapid PCB water-to-air transfer (US EPA, 2000a,b) but, professing to disbelieve the empirical data, reduced the effect of these data on the HRA: EPA reduced the water-to-air transfer coefficient for PCBs by averaging in modeled PCB transfer coefficients that were orders of magnitude lower than the empirical findings because the modeled values ignored codistillation. Finally, EPA omitted PCB release into the atmosphere from hot water in cooling towers in communities along the Hudson River. Water at cooling-tower temperatures may release PCB into the air more than 10 times faster than rates determined from the surface of cold water and multiple orders of magnitude more rapidly than predicted by EPA’s cold-river models.

Together, EPA’s procedures reduced airborne PCB concentrations from above to below de minimis concentrations. This in turn eliminated the requirement (NYS DEC, 1997) for EPA’s HRA [and other HRAs (such as PSEG, 2001)] to quantify inhalation risks posed by airborne PCBs. These HRaAs, therefore, “considered” airborne PCBs, but erroneously attributed zero (de minimis) health risk to them.

Our assessment is appropriately conservative. In the context of error and the aforementioned pro-dredging bias for

the dredging decision-making process (US EPA, 2006), “conservative” means being careful to err on the side of agreement with EPA rather than on the side of exaggerating EPA’s troubling methodological shortcomings and the consequences thereof (Michaels and Oko, 2007). Notwithstanding this troubling context, our assessment adopts two premises long advocated by EPA:

1. The scope of issues to be considered during the interphase period, as defined by EPA, explicitly excludes consideration of terminating the project and thereby abandoning Phase 2.

2. If dredging is to proceed to Phase 2, the manner in which it will be conducted minimally must assure conformity with EPA’s criterion that net benefit must be achieved compared with no action/no dredging.

Three major issue areas most essentially are addressed in our assessment, and should be considered during the interphase period:

1. the possible need to modify dredging in Phase 2,

2. the possible need to modify the benefit criterion in Phase 2, and

3. the possible need to modify the monitoring program in Phase 2.

Hudson River PCB Dredging 379

Our assessment addresses technical and policy issues within these three major issue areas.

Methods

Our analysis is based upon activities including conducting site visits to observe and photograph dredging, visiting EPA's field office in Fort Edward, interviewing EPA and GE personnel and contractors, analyzing dredging data, attending public meetings, and examining scientific and technical reports. Our analysis adopts the methods of HRA, critical evaluation of scientific information sources (e.g., GE, 2009, 2010a—c; Gruendell et al., 1996; Michaels and Oko, 2007; United Nations Environment Programme, 2003; US EPA, 2010a—c) and objective scientific peer review. The latter are not a priori methods, and they are not described in detail here. Rather, they consist of the diverse methods that are generally typical of peer review by scientists seeking to remain objective. Most essentially, these methods consist of our own disciplined, critical evaluation of the scientific merit with which numerous methods were selected for use and applied prior to dredging, during dredging Phase 1, and after Phase 1. The scope of our assessment therefore includes our own peer review of GE and EPA methods, findings, and conclusions, such as those reported orally in public meetings, and in written public communications on GE (2010c) and EPA (2010b,c) Web sites for Hudson River dredging, and more formally in GE (2010a,b) and EPA (2010a) draft and final reports published for consideration by the public, specific interested parties, and members of the Hudson River dredging project’s Peer Review Panel. Members of the public and other readers of our assessment can judge for themselves whether and to what degree we succeeded in applying the methods of HRA and of peer review objectively. We hope that we have done so completely.

Findings Possible Need to Modify Dredging in Phase 2

Mobilization of PCB-tainted sediment

A major discrepancy exists between sediment mobilized in Phase I of GE’s EPA-mandated Hudson River PCB dredging project versus the much smaller amount of sediment mobilization measured and reported by GE (2010a~-c) and EPA (2010a—c). Sediment mobilization as reported by GE and EPA refers to the amount that is “resuspended” by

380 Environmental Practice 12 (4) December 2010

dredging, and monitored miles downstream of the Phase I dredging area, almost all of which is located near Roger’s Island, some 7 miles from the monitoring station. As EPA has reported, however, most dredged sediment falls back to the river bottom in the trench or near the spot from which it was dredged initially. Thus, the preponderance of mobilized sediment remains on the river bottom, still mobile, but unrecorded in GE or EPA sediment mobilization data ... hence the “sediment mobilization discrepancy.”

The sediment mobilization discrepancy represents more than merely a difference between a measured and an actual parameter value. Rather, it represents a fundamental inconsistency in EPA’s past justification of the need to dredge versus EPA’s current characterization of the performance of the dredging project in Phase 1. The need for dredging was justified by the mobility of sediments in PCB “hotspots” requiring, according to EPA, their removal by dredging. Indeed, a small but persistent trickle of buried PCB moving downstream was documented from PCB hotspots (e.g., see US EPA, 2006), of which 27 were selected for remediation via dredging.

In contrast, in the new context of actual dredging in Phase 1, EPA dramatically has altered its concept of mobility. Mobility in the dredging project is newly quantified by the lightest-weight fractions of PCB-tainted sediments measured resuspended in the water at the Thompson Island Dam about 7 miles downstream of the preponderance of Phase I dredging, further downstream at Lock 5, and still further downstream at Waterford [see US EPA's illustration (20104), reprinted as Figure 2 here].

EPA’s altered terminology, referring to mobilized sediment as sediment “loading” or “resuspension” estimates, confuses the issue. These parameters quantify only near-term mobilization and ignore the reality that all of the sediment that falls back to the riverbed also is “mobilized,” in the original sense of that term as used by EPA to justify dredging. That is, it is mobilized because it can enter riverine ecosystems and can reenter the water column via physical, chemical, and biological processes. Examples include, respectively, scouring under turbulent high-flow river conditions, dissolution, and microbial metabolism. Mobilized sediment also can be transported by migrating organisms, such as fish and birds, and can enter the air in communities directly from river water or from heated sources (cooling towers; Michaels and Oko, 2007) used to control industrial processes, such as in factories and power plants.

450 |

Total: 437

400 |

350 |

300 5

250 |

200 }----

150 4

Net Total PCB Cumulative Load (kg)

100 5

50 4

Total: 269

1% Mass Removed (200 kg)

117 kg Annual Load Limit Total: 151

Thompson Island

LockS Waterford

Far-field Stations

Figure 2. Resuspension of sediment particles bearing trichlorinated to decachlorinated PCB measured at three stations miles

downstream of Phase 1 dredging. Source: US EPA (20104).

Quantifying mobilization of PCB-tainted sediment

We initially estimated that 80% of sediment disrupted by dredging was mobilized rather than transferred to barges. This estimate was based upon the size, shape, and operation of typical 5-cubic-yard dredge buckets that open to a width of 15 feet; that is, enclosing 15 feet of river bottom to a design depth of about 1.5 feet, and then close to a width that we visually estimate at about 3 feet (zero feet at the bottom, wider higher up). We observed that, as the buckets close, they compress their contents, squeezing inward and upward about 12/15ths (80%) of the sediments that were initially enclosed within their jaws.

These buckets also were found to leak excessively because of obstructions in the river bottom that prevent their complete closure (Figure 3). Obstructions preventing bucket closure include stones, automobile tires, tree branches, bottles and cans, and construction debris such as concrete and boards. During closure, enclosed sediments are compressed from an open-jaw width of about 15 feet to a

closed-jaw width of zero feet at the bottom (maybe about 3 feet in average width from the bottom nose of the bucket to the top of its sediment load). As dredge buckets are open at the top, this “squishing” forces out a slurry of sediment and water. Leakage of incompletely closed buckets drops material onto the river surface (Figure 4). Our 80% mobilization estimate was approximate at best, in part because not all buckets were of 5-cubic-yard capacity (see Table 1, the inventory of dredge buckets used in Phase 1).

We now have quantified the mobilization parameter more reliably by using GE’s “bucket files” (GE, 2010a). GE’s bucket files are computer registers recording each closure of a dredge bucket in each delineated 5-acre work unit [Certification Unit (CU)]. The Phase I dredging area consisted of 18 CUs and about 90 acres, but dredging actually occurred at just 10 CUs, or about 50 acres. Analysis of these GE files revealed that the preponderance of sediment disturbed by dredge buckets was left in mobile form on the river bottom, not placed in waiting barges. We related the number

Hudson River PCB Dredging 381

Figure 3. Dredge buckets should close completely before lifting their sediment load, but they leak excessively because obstructions prevent complete closure. Hudson River dredging site, July 28, 2009.

of bucket closures in each CU to separately reported information about the volume of sediment placed in barges in each CU. This analysis is summarized in Table 2, in which all bucket closures in all CUs are summed.

As Table 2 indicates, the preponderance of dredged material was not barged, but mobilized. The exact fraction mobilized depends upon the capacity of the dredge buckets that were used. The dredge bucket capacity in turn depends upon the maximum capacity of each bucket and the depth of its bite into the sediment, both of which were variable because three bucket sizes were used (Table 1), and sometimes they did not penetrate to their full design depth; for example, if they struck a boulder or construction debris. The standard bucket capacity was 5 cubic yards with a design penetration depth of 18 inches. The five 5-cubic-

382 Environmental Practice 12 (4) December 2010

yard buckets were used routinely, notwithstanding that more 1-cubic-yard buckets (seven) were available for standby use in sensitive spots, especially near shore. The project also had one 2-cubic-yard bucket (Table 1). We further assume that the design penetration depth was typically the target depth, so the overall average bucket capacity probably was close to 5 cubic yards.

As Table 2 shows, Phase I dredging pulled out 286,006 cubic yards of sediment (actually a slurry of sediment and river water), which went into barges (topped by a layer of water). The dredge buckets closed 221,521 times, producing an average load of 1.29 cubic yards per bucket load that was transferred to waiting barges (including the water). The amount of sediment to be rail-shipped to Texas is less, because sediments must be dried before loading. Even using

Figure 4. Dredge closure forces a slurry of sediment and water upward through the open top of the bucket, and leakage of incompletely closed buckets drops material onto the river surface. Hudson River dredging site, July 28, 2009.

Table 1. Summary of bucket volume, by dredge

Bucket volume

Dredge name Dredge type (cubic yards) 320-09 320 1 320-10 320 1 320-11 320 1 320-12 320 1 320-13 320 1 320-14 320 1 320-16 320 1 345-07 345 2 385-02 385 5 385-03 385 5 385-04 385 5 385-05 385 5 385-06 385 5

Source: General Electric (2010a,b, Appendix N, Table N-1).

the larger figure as the estimate of barged “sediment,” however, the amount barged still is only 26% of an assumed 5-cubic-yard average bucket capacity, or 32% of a 4-cubic-yard capacity, or 43% of a 3-cubic-yard capacity.

That means that the amount of sediment that was mobilized was 74% if the average bucket capacity is assumed to be 5 cubic yards, 68% if 4 cubic yards, and 57% if 3 cubic yards. Under any of these assumptions, the preponderance of material was mobilized, not barged, and still more was

Table 2. Sediment retention vs. mobilization in Phase 1 of Hudson River polychlorinated biphenyl (PCB) dredging, based upon automated recording of dredge bucket closures*

221,521 286,006

Number of dredge bucket closures”

Volume of sediment removed, transferred to barges

[cubic yards (yd?)]

1.29 Volume of sediment removed per bucket closure

(yd?/bucket load)

Sediment load retained in bucket vs. mobilized . . .< ... assuming average bucket capacity = 5 yd>

25.8 Percent retained and barged 74.2 Percent mobilized

... assuming average bucket capacity = 4 yd? 32.3 Percent retained and barged 67.7 Percent mobilized

... assuming average bucket capacity = 3 yd? 43.0 Percent retained and barged 57.0 Percent mobilized

* Additional sediment was mobilized when buckets impacted the river bottom but failed to close; these bucket rejection events were unrecorded. Mobilized sediment may be removed by future dredging if it falls back to the bottom at a location that is within a dredging prism.

> Data acceptance criterion: depth is below 119-foot elevation.

Source: Tabulated values represent results of our analysis of General Electric (2010b) Phase 1 dredging project data, most notably GE’s bucket files (Appendix G, Table G-1).

mobilized when dredge buckets descended to the river bottom, but failed to close (termed bucket rejection). Some of the mobilized sediment, however, might have been dredged again, and a further fraction removed from the river, if the sediment fell back to the river bottom within a “prism” slated for future dredging.

We regard our best sediment mobilization estimate as 74% for the 5-cubic-yard-capacity bucket typically used. That estimate is a minimum, as it excludes sediment that is disrupted by dredge buckets when they crash to the bottom but fail to close because of obstructions such as boulders or construction debris. These factors bring the mobilization fraction closer to our initial, independent estimate of 80%, though we can quantify reliably only the 74% minimum estimate, which therefore is only approximate if viewed as a total mobilization fraction.

The mobilized fraction of sediment, therefore, conservatively amounts to about 1,100,000 cubic yards, which is approximately 3.7 million metric tons (tonnes), assuming a dredged sediment specific gravity of about 2.6 compared with water (Gruendell et al., 1996). Yet, EPA’s illustration

Hudson River PCB Dredging 383

(Figure 1) reports 437 kg resuspended sediment load at Thompson Island, 269 kg at Lock 5, and 151 kg at Waterford. Ignoring obvious double counting, EPA reports 857 kg of mobilized “resuspended” sediment, which is drastically less than 744 million kg. Thus, EPA’s figures exclude nearly all mobilized sediment. EPA simply has ignored the preponderance of sediment mobilization, and PCB mobilization, in evaluating the performance of the dredging project in Phase 1, notwithstanding that the persistent mobility of dissolved, colloidal, and fine-particle-adsorbed PCB originally constituted for EPA a central rationale for specifying the dredging remedy for the Hudson River PCB Superfund site.

Downstream PCB deposition

PCB in dredged, redeposited sediments is more mobile than was the case in the original buried state, which ironically is the physical state that EPA’s strategy of capping dredge prisms has sought to restore. From the river bottom, resting sediment piles produced by Phase I dredging gradually (perhaps over years) can and will erode. Some sediment will travel downstream, to be measured by GE in the EPA-mandated “resuspension” monitoring program. Indeed, on March 28, 2010, recently analyzed Hudson River water samples were reported to harbor PCB levels nearly five times higher than the federal drinking-water standard of 500 parts per trillion (ppt). This news reasonably could have been anticipated. The episode was reported to have been caused by scouring of PCB-tainted sediments from the river bottom during a “high flow” event, in which river flow past Thompson Island increased from 5,000 cubic feet per second (CFS) to a peak of 36,000 CFS (e.g., see US EPA, 2010b,c).

We also note two Key Findings in GE’s Phase 1 Evaluation Report (2010b, p. 77):

¢ Dredging activities caused previously buried PCBcontaining sediments to migrate downstream and settle on the surface of the river bottom, where they became bioavailable. PCB concentrations in downstream sediment traps ranged from approximately 24 to 126 mg/kg Total PCBs, with an average of 61 mg/ kg, and downstream sediment cores of previously sampled areas showed an average increase of three times pre-dredging concentrations. These and other lines of evidence show that dredging caused widespread redistribution of PCB-containing sediments on the surface of the river bottom.

384 Environmental Practice 12 (4) December 2010

¢ These re-deposited sediments continued to release PCBs to the river well after the completion of dredging activities [emphasis added].

Demonstrably, as already shown, residual sediments disturbed by dredging are mobile, along with their PCB load. If a full dredge bucket averages 5 cubic yards, then just about a quarter of dredged sediment was transferred to barges. Some of the remainder must flow downstream with the current. The rest falls back to the river bottom, where it exists as loosely agglomerated piles of dredge spoils, including clay and mud. River currents, as illustrated by the high-flow event previously described, erode this material gradually back into the water column, from which PCBs may enter the air and ecosystems, including migrat-

ing fish and birds.

As the river again slows to its normal flow rate, some scoured, resuspended PCB-tainted sediment will settle (redeposit) downstream. As EPA’s illustration shows (Figure 2), the amount of resuspended sediment diminishes from upstream to downstream, documenting (and roughly quantifying) redeposition (roughly, as dilution also must have contributed to the decrease).

Significance of downstream deposition

Downstream deposition of river sediment involves a wide spectrum of particle sizes. Clamshell dredges preferentially capture the coarse particles: sand and rocks that have relatively little surface area. In other words, clamshell dredges preferentially leave behind relatively small particles, having the greatest surface area, on which the greatest amount of PCB is adsorbed. Dredges preferentially capture the relatively small fraction of the PCBs that are adsorbed on sand and rocks. To illustrate, consider PCB adsorption to carbon (McDonough, Fairey, and Lowry, 2008). PCB affinity for carbon is high, on average about 500 ng/m?, which reasonably might be expected also to approximate PCB affinity for Hudson River rocks and smaller particles, such as clay and mud.

If the carbon is formed into a cube, its surface area is six times the face of the cube. If the cube then is divided into finer cubes, the total surface area increases, as does PCB adsorption onto the smaller cubes. A cubic particle with a 0.01-cm side presents a surface area of 0.0006 cm? for adsorption, whereas the same amount of particulate matter divided into 1,000 smaller particles, each with a 0.0001-cm (1 mm) side, presents an aggregate surface area of 0.6 cm?, 1,000 times greater. That is still a coarse particle. If the

cube, however, is subdivided finely enough (say, to the micrometer range), its surface area becomes so large that the material acquires a new name based upon its propensity to adsorb substances such as PCBs: activated carbon, or activated charcoal. Gram for gram, fine or ultrafine Hudson River particles in the size range that is preferentially mobilized by dredging can and will adsorb PCBs in amounts that are millions of times higher than adsorption onto coarse particles, just as activated carbon adsorbs PCBs more efficiently than does a coarse block of carbon.

Upon closure of clamshells, these fine, PCB-laden particles preferentially leak into the water column, which carries many of them downstream. These particulates eventually settle. Repeated action of the dredges causes this moving front to become increasingly concentrated with PCBs.

Clamshell buckets, as already described, tend to exert not only a mobilizing effect on sediment, but also a particle resorting (or classification) effect, which constitutes one burden of PCB dredging. Moving the pontoon-mounted dredge platform and clamshell downstream effectively constitutes chasing a moving, increasingly concentrated PCB front to previously uncontaminated river areas. Depending on water-flow velocity, this can be a few hundred feet or many miles downstream of the dredge.

Perhaps the dredge type that is most damaging to the environment is pontoon-mounted backhoe/excavator dredges, of the type used in Phase I. Underwater bucket closure compresses the contents, forcing much water and sediment out of the open top of the dredge bucket, preferentially dispersing relatively fine particulates into the flowing water column (Figure 4). These relatively small particulates are slowest to settle and most susceptible to downstream migration. To prevent such migration, other types of dredges could be used. Those that suck up the bottom sediment with water to be discharged into hoppers for sedimentation and/or treatment might be most effective. The process of dredging-induced gradual sediment resuspension followed by downstream flow and redeposition illustrates that, most essentially, four insidious processes are under way:

1. PCB spreading, 2. PCB entry into Hudson River ecosystems, 3. PCB resuspension increase in high-flow events, and

4. PCB storage increase in Hudson River ecosystems.

PCB spreading. One insidious process is spreading of PCB from sectors of the river bottom dredged in Phase 1 to undredged sectors downstream. In the long term, PCB movement from sediments to river water, ecosystems, and air depends upon the surface area of contaminated river bottom, not on the volume of buried (nearly all immobile) PCB... and the area of river bottom that is contaminated is increasing due to dredging. Dredging in Phase 1 was intensively concentrated in a relatively small area (somewhat over half of the full 90 acres included in Phase 1), so dredging affected a high fraction of the river bottom in the Phase 1 area. This cannot be the case in Phase 2. Most of the river bottom on which resuspended PCB-tainted sediments will settle is not scheduled for dredging in Phase 2. As a result, PCB will continue to spread and redeposit over a gradually increasing area of river bottom, nearly all of which is not scheduled for dredging, ever.

PCB entry into Hudson River ecosystems. As the area of river bottom affected by redeposition of mobilized PCBtainted sediments increases, PCB will enter river ecosystems beyond the Phase 1 area. These will include detritus ecosystems and ecosystems involving the higher trophic levels, from primary producers (phytoplankton and rooted plants) to herbivores (such as carp), primary carnivores (zooplankton and some fish), and secondary and tertiary carnivores (including some large fish, amphibians, reptiles, and mammals).

Already, GE and EPA have reported fivefold increases in PCB concentrations in fish tissue (GE, 2010b; US EPA, 2010a), but these bioconcentration data represent a misleading underestimate of the degree of increase. The data reflect analysis of muscle tissue of fish (filets), whereas PCB levels in organs (especially fish liver) may be 2-3 orders of magnitude higher. Some people, especially American Indians, consume fish organ meats. Fish also are consumed in their entirety by microbes and by predators other than humans. Thus, the PCB load entering Hudson River ecosystems from dredging is grossly underestimated by data on PCB concentrations in fish filets.

PCB resuspension increase in high-flow events. As the area of river bottom affected by downstream movement of mobilized PCB increases, the effectiveness of increased river flow at suspending redeposited PCB-tainted sediment will increase, even if the scouring efficiency remains constant for any particular current speed. This is because the scouring efficiency, whatever it is quantitatively, will affect a larger area of the river bottom. In ad-

Hudson River PCB Dredging 385

dition, the scouring efficiency may increase for any given river flow rate because relatively low-mass particles will be the ones preferentially transported downriver from the Phase 1 area. This also suggests that the duration of river flow-induced exceedances of the 500-ppt federal drinkingwater standard for PCB may increase, as the fraction of river bottom contributing to the exceedances increases. Monitoring data (US EPA, 2010b,c) suggest that such highflow events may occur with a frequency in the range of once to 10 times per year.

PCB storage increase in Hudson River ecosystems. The aforementioned processes can be expected to alter the distribution of PCB originally confined to 27 hotspots slated for dredging to a wider, and widening, river sector. This sector will continue to expand and, along with it, the fraction of Hudson River ecosystem area affected by PCB will increase. These riverine ecosystems will relate to mobilized PCB-tainted sediments originating from dredged hotspots as a pollutant source to a pollutant sink.

This phenomenon was documented (for example, by Carson, 1962) in a famous case study involving the chlorinated pesticide DDT, which closely resembles PCB both structurally and dynamically (though PCB is somewhat more water-soluble and less long-lived in ecosystems). The uses of DDT and PCB differ, but dissemination of DDT (and its breakdown products DDE and DDD) to the environment of Clear Lake, California, to control midges (the Clear Lake “gnat”) is analogous to dissemination of PCB to the Hudson River. PCB and DDT for many decades have been disseminated to ecosystems globally, so much so that discerning their effects experimentally has been difficult for lack of unaffected control ecosystems. DDT and PCB, which have co-occurred in environmental samples for many decades, are similar structurally:

32 2.3 at cl ory Ten JV ; PCBs DDT

Indeed, their structures are so similar that, until the 1960s, only DDT was discerned analytically in environmental samples, resulting in ecological effects of DDT and PCB together being attributed solely to DDT. Structural analogues often exert similar toxic and environmental effects [termed structure-activity relationships (SARs)]. The possible consequences of spreading PCB more widely in the Hudson

386 Environmental Practice 12 (4) December 2010

River are worthy of considering in light of the Clear Lake (and global) experience with DDT. In Clear Lake, significant residues of DDT were not found, as DDT is nearly water-insoluble. This negative finding, however, proved to be misleading, as the biota of Clear Lake proved to be a major sink for DDT, which dramatically bioconcentrated, bioaccumulated, and biomagnified in its ecosystems.

By these processes, DDT (and related chlorinated hydrocarbons) exerted significant effects from which global ecosystems are just now recovering. For example, bald eagles and peregrine falcons were threatened with extinction because DDT thinned their eggshells, causing drastic population declines. Similarly, dredging-induced mobilization of PCB-tainted sediments reasonably may be expected to reintroduce PCB into receptive ecosystems, thereby setting back the clock for river recovery by four decades, during which PCB may be reburied as it was before being dredged this past year in Phase 1.

Possible Need to Modify the Benefit Criterion in Phase 2

Contravention of the benefit criterion

The EPA illustration reproduced earlier (Figure 2) documents contravention of the benefit criterion. GE and EPA used mid-Phase 1 data to attempt dredging modifications in real time to restore adherence to the benefit criterion. These efforts succeeded at reducing PCB resuspension, but not to a degree sufficient to restore adherence to the benefit criterion, as shown in Figure 2. These facts have been widely acknowledged (most notably, see GE, 2010b; US EPA, 2010a) and will not be amplified here.

Flaws of the benefit criterion

The benefit criterion allows no increase in downstream transport of resuspended sediment for the duration of the dredging project. Instead, under the benefit criterion, downstream transport may be increased by dredging in the short term, but only in amounts that will be offset by future decreases over the longer term, meaning the project duration. This benefit criterion is illogical for two reasons:

1. It assumes incorrectly that downstream transport of PCBladen sediments will stop when dredging stops in six or seven years. This assumption has been refuted by the observed decades-long mobility of PCB, even when buried beneath the river bottom. Dredged sediment that is re-

doi:10.1017/S1466046610000529

deposited onto the river bottom likewise will erode into the water column and travel downstream, along with its adsorbed PCB load, for decades to come. The rate of erosion, however, will be significantly increased (with contaminated riverbed surface area) compared with the low rate that EPA used to justify dredging.

2. It assumes incorrectly that potential dredging impacts consist of nothing more than downstream transport of resuspended sediment, whereas this appears to constitute a relatively minor contributor to total potential dredging impacts, even when considered only during the restricted dredging period of five or six more years. Maintaining a stringent resuspension performance standard, even if it could be met, still allows harm from entry of PCB from tainted sediments deposited on the river bottom into river ecosystems, including migrating birds and fish, and into the air that is breathed by people living in river communities.

Possible Need to Modify the Monitoring Program in Phase 2

Liquid PCB oils

EPA reported at a public meeting in the Hudson River town of Fort Edward, New York, on August 19, 2009, that GE clamshell dredges had started to encounter liquid PCB oils in dredging prisms (see also GE, 2010b,c; US EPA, 2010a,b). This development is worthy of note because pure PCB oils [1,000,000 parts per million (ppm)] must be viewed in an entirely different, more ominous context than river sediments harboring PCBs in the low-ppm concentration range. Mobilizing liquid PCB oils via dredging is commensurately more serious than mobilizing sediments bearing PCBs in the low-ppm range as originally anticipated.

EPA later acknowledged [for a magazine article (Brickley, 2009)] that the project recently had discovered sheens of liquid PCB oil on the river surface, “an indication, the EPA said, that the river floor contained not only contaminated silt, but more potent pockets of pure PCB oil—and that the dredging is releasing the oil into the river water.” EPA, however, placed a relatively benign spin on this news: “It’s not really affecting dredging, that’s why we’ve taken those mitigation measures to, you know, to counteract the sheens.” Counteracting microscopically thin PCB sheens visible on the river surface, however, fails to address the real challenge: counteracting remnant pools of originally disposed liquid PCB oils of unknown, potentially large volume in trenches beneath.

PCB sheens on the river surface constitute evidence of the presence of liquid (near pure) PCB and constitute yet another source of airborne PCB not addressed in any EPA assessment of risks to health potentially posed by sediment dredging at PCB hotspots in the Hudson River. These PCB sheens cannot have originated from desorption from sediments, because a sheen is a continuous monomolecular layer of liquid PCB. Their observation, therefore, raises the question of whether they might be expected to arise from underlying sediments bearing PCBs in merely the ppm range, or whether they must originate from more massive pools of liquid PCB oils at the river bottom as originally suggested by EPA.

Can bottom sediments form surface sheens via some upward PCB migration process? Three factors suggest not:

1. PCBs chemically bound to sediments for decades are unlikely to become unbound, especially as liquid PCB oil;

2. if they did become unbound, they also would have to become concentrated from the low-ppm range at the river bottom to near purity at the surface, which is unlikely to occur in a flowing, turbulent river; and

3. PCB oils are denser than water, so they would be expected to sink, not to rise from the bottom, unless physically forced upward, or lifted; just a small fraction of more-water-soluble PCB congeners might reach saturation in the water, and may appear as a sheen on the river surface.

PCB liquids include more than 200 types, or congeners, varying in their degree and pattern of chlorination (with from 1 to 10 chlorine atoms per PCB molecule). Each congener has a unique density, but bulk density of commercial PCBs of the types disposed to the Hudson River (known as Aroclors, manufactured from approximately 1930 to 1979) are reported to have a density of about 1.5 grams per milliliter [g/ml (Gruendell et al., 1996)], which is 1.5 times the density of water.

The most probable origin of PCB liquids forming surface sheens, in our view and apparently also in EPA’s view (based upon oral statements), is that dredge buckets massively disrupt them from pools of liquid PCB oils formed in sediment low points (depressions) following original disposal from land-based facilities or ships. These bottom pools gradually might have become covered with debris and sediments. The onset of dredging may be forcing the liquids upward toward the surface as dredge jaws expose them and close around them. This process is visible for

Hudson River PCB Dredging 387

sediments (which have tightly bound PCBs that would not be expected to form sheens) and reasonably would apply as well to liquid pools (which would be expected to form surface sheens).

Sediments and PCB oils that are not forced upward by closing dredge jaws might be retained within dredge buckets, and physically lifted. These materials would be subject to leakage during their ascent to the surface and beyond. These dual processes of disruption by squishing and by lifting reasonably would be expected to generate PCB liquids and PCB sheens at the surface, as PCBs are chemically attracted to surfaces, including to the air-water interface in rivers.

EPA's report of encountering PCB liquids seems, at least in retrospect, unsurprising given the history of past PCB disposal into the river in the form of liquid PCB oils from land-based facilities and from ships. Given this history, why did EPA adopt the clamshell method of dredging, thereby failing to prepare for this seemingly expectable eventuality? Its actuality casts further doubt on the wisdom of EPA having prescribed clamshell dredging rather than vacuum dredging, or no dredging, for remediation of the Hudson River PCB Superfund site.

One objection to the liquid-pool hypothesis that must be addressed is that PCB concentrations in downstream water samples have not revealed PCB oils or concentrations high enough to suggest their presence upstream. The heavier-than-water density of PCBs, however, would be expected to cause them to hug the river bottom as they move downstream. They would not be expected to register in surface or mid-depth water samples taken 5-7 miles downstream.

In planning dredging Phase 2, EPA (and GE) are faced with the quandary of whether to

1. mobilize PCB oils by continuing clamshell dredging, even though the dredge buckets cannot retain the oils efficiently,

2. allow the PCB oils to be mobilized by river currents washing over the now-exposed pools,

3. institute vacuum dredging or dredging within enclosures, or

4. stabilize the oils by covering them over again.

388 Environmental Practice 12 (4) December 2010

Monitoring for waterborne PCB

Waterborne PCB in the Hudson River, including water in dredge buckets and barges, constitutes the primary source of airborne PCB. Indeed, EPA studied the relationship of waterborne PCB in a cold river to airborne PCB 1 m above the river surface (US EPA, 2000a,b). That study produced the EPA benchmark termed the level of concern (LOC) for airborne PCB of 0.08 jg/m3, which is the air level estimated to be generated by waterborne PCB at EPA’s maximum contaminant level (MCL) for PCB of 500 ppt.? Generated primarily by dredging, waterborne PCB therefore should be measured where dredging occurs ... but that was not done in Phase 1. Instead of sampling at Rogers Island, water was sampled, and waterborne PCB measured, near Thompson Island, about 7 miles downstream of Rogers Island. As a result, waterborne PCB concentrations at dredging sites are anyone’s guess, specifically determined by anyone’s guess about the applicable dilution factor that occurs as dredge-mobilized material travels 5-7 miles downstream.

Monitoring for airborne PCB

Just as waterborne PCB concentrations at dredging locations are anyone’s guess, airborne PCB concentrations at dredge sites also are anyone’s guess, in part because airborne PCB monitoring at dredging platforms in Phase 1 consisted of personnel monitoring with sensitivity to the Occupational Safety and Health Administration’s occupational standard of 1,000 g/m? for airborne PCB (see the next section). Airborne PCB was monitored primarily by two portable air samplers set up adjacent to each dredge platform, on opposite banks of the river.

These samplers recorded 24-hour average concentrations of airborne PCB. Three problems undermined the usefulness of these monitors. First, personnel engaged in dredging are exposed to aerosols generated at the dredge platform, which reasonably would be expected to fall back to the river surface before reaching the monitors on shore, except when wind speed is adequate to transport them as far as the shore and when wind direction is aimed at a portable monitor. In those cases, of course, only one monitor would record the PCB, because the wind would be blowing away from the monitor on the opposite shore. Second, wind direction varies, so each air monitor would be pumping air that originated from 360°, not primarily from the direction of the dredge platform to which it is adjacent. This is illustrated in Figure 5, in which gray arrows represent air originating from the dredge platform, and the preponderance of black arrows represent air originating from other directions.

by ud OR

17 We

yf \ A ye

J \

Figure 5. PCB entry into air was quantified in Phase 1 via portable on-shore monitors (M) placed on opposite shores adjacent to each dredge unit. Gray arrows represent air originating from the dredge platform; the preponderant black arrows represent air originating from all other directions. Only average airborne PCB concentrations therefore are recorded. Peak airborne PCB concentrations that may be sampled are not reported because they are mixed with air from originating from all directions over a 24-h period.

Figure 5 also illustrates how, as the dredge platform moves downstream, the angle from which PCB might impinge on the portable monitor increases. Thus, a time series should show increasing airborne PCB concentrations as the surface area of dredged river increases. This observation actually cannot be made, however, because GE procedures call for moving each portable air monitor downstream with its adjacent dredge platform, so no monitor remains to record evolving airborne PCB concentrations at any former dredge site. Indeed, as the area of dredged river surface increases to its maximum, the concentration of airborne monitors per acre of dredged river declines in direct proportion because no monitors are added to cover the increased area of dredged river.

This gives rise to the third problem: PCB volatilization might not reach a steady state until long after the portable air monitors are withdrawn downstream with the dredge platforms. Indeed, PCB release from the river surface might not reach steady-state rates until long after completion of Phase I. By then, portable monitors would have been withdrawn, not only to points downstream, but altogether. In short, the monitors are withdrawn before they can characterize the evolution of PCB release to the air over the remaining six-year planned life of the project and beyond.

Indeed, as the acreage of dredged river increases, the number of monitors per acre declines, but the fraction of river

surface contributing to air levels over the river and on shore increases . . . never to be measured because the monitors that could have measured these evolving levels were withdrawn from service. EPA could require a permanent array of air monitors to capture the evolution of PCB release levels as the fraction of river bottom that has been dredged increases and as PCB-tainted sediments are restratified by physical, chemical, and biological processes of degradation, mobilization, and eventual release to ecosystems and the atmosphere.

One strategy to rectify this egregious situation might be effective: examining meteorology data to determine the fraction of time when wind direction was toward a portable air sampler on shore. If the fraction of time was, say, 1%, then the airborne concentration from the point of origin (the dredge platform) would have been at least 100 times higher than the concentration reported by the sampling unit (we say “at least” because the sampling unit would not have recorded PCB-bearing aerosols that had precipitated back to the river surface before reaching shore). We do not know whether the required meteorology data are available.

Personnel monitoring for exposure to airborne PCB

A major concern associated with PCB dredging relates to risks potentially posed to human health (Michaels and Oko, 2007). Apart from participation of people as ecosystem components at the top of the food chain is the issue of airborne PCB, which is derived from PCB released to the water, and which is monitored only at great distance from dredge sites, as discussed earlier. To help elucidate this issue, EPA could demand delivery of the results of personal monitoring samples taken on dredge platforms, minus confidential employee-identifying information. These samples generated the only data of which we are aware that reflect airborne PCB levels produced by dredging, at the location of dredge platforms. These samplers, unfortunately, operated with sensitivity to the occupational airborne PCB limit of 1,000 g/m, which is over 9,000 times higher than EPA’s residential limit of 11 wg/m3. If any of these samples were positive, that fact should be disclosed. EPA, however, indicated that the personal monitoring data belong to GE, and GE indicated that the data belong to its contractors. Information of possibly critical concern to the public has been “compartmentalized” thereby, out of public view. Reason exists to demand these data, because some personnel monitoring samples might be positive, even at the high threshold of detection.

Hudson River PCB Dredging 389

Indeed, EPA data relating PCB in water to PCB in air suggest that air levels must be excessive at dredging platform locations. EPA quantified the relationship between PCB concentrations in water from a cold river and in air 1 m above the river surface (US EPA, 2000a,b). For each microgram per liter (that is, for each 1,000 ppt) of PCB in river water, PCB concentrations in air (in szg/m3) were reported to be a minimum of 0.02, a median of 0.09, a mean of 0.15, and a maximum of 0.40 g/m? (Michaels and Oko, 2007; US EPA, 2000a,b). When waterborne PCB reaches EPA’s 500-ppt stop-dredging benchmark, airborne PCB 1 m above the river would be expected to be at about the mean observed value, 0.08 g/m. Significantly, that concentration also is EPA’s airborne PCB level of concern (LOC). Measurements of waterborne PCB, revealing exceedances of the 500-ppt benchmark, were taken 5~7 miles downstream of dredging locations. Waterborne PCB concentrations at locations of dredge platforms must be higher, perhaps thousands of times higher than at locations miles away (ppm rather than ppt) or even millions of times higher (parts per thousand rather than trillion) where liquid PCB oils have been encountered. These massively higher waterborne concentrations imply massively higher airborne concentrations at dredge platform locations.

Potential occupational exposure at dredging platform locations also might be significantly greater than that implied by EPA’s published relationship of waterborne PCB to airborne PCB. This is because the original EPA data relating airborne levels of PCB over a cold river to the source PCB levels in the river water do not account for dredge buckets in the Hudson River billowing sediments to the river surface as they close, and then lifting sediments and water above the surface, where leakage drops sediments and water violently onto the river surface. These processes must produce abundant droplets (aerosols) of various sizes, all containing PCBs, whereas air samples above river water in EPA’s original data did not include this source of airborne PCB. So, for occupationally exposed individuals, the relationship of PCB levels in water to levels in air must be significantly worse, exposing them to inhalable PCBs that are volatilized, as well as to PCBs that are aerosolized. That unhealthy process happens yet again when the dredges swing their retained load over the barges and drop them again, this time in their entirety, producing yet another burst of PCB entry into the air in the form of vapors and aerosols near dredge platform personnel.

Though airborne PCB concentrations in the dredging cor-

ridor would seem to be higher than EPA’s stop-dredging standards as explained earlier, the nearest measurements

390 Environmental Practice 12 (4) December 2010

are taken on shore rather than on location (see the previous section). EPA established a stop-dredging standard of 0.11 g/m} for airborne PCB in residential zones and of 0.26 g/m} for airborne PCB in commercial zones. Indeed, EPA ordered GE to stop dredging on multiple occasions, when the waterborne level was =500 ppt and presumably the air level was about =o.08 wg/m>.

Conclusions and Recommendations

Conclusions

Risks to human health potentially posed by airborne pathways of exposure to PCB under dredging and nondredging scenarios were neither assessed objectively nor compared. Water monitoring miles downstream of dredging to measure sediment loading or “resuspension” is inadequate to characterize PCB mobilization. Air monitoring using portable air samplers on shore is inadequate to quantify either residential or commercial exposure to airborne PCB. Results of personal air monitoring of GE dredging personnel remain undisclosed, therefore failing to satisfy the legitimate public interest in gaining access to this unique source of data on airborne PCB levels at dredge platforms. Levels of airborne PCB probably were higher than suggested by available data, and possibly unsafe.

EPA’s emphasis on PCB sheens observed during dredging, rather than on the possibly substantial source pools of liquid PCB hidden from view in the river bottom, is misplaced. Dredged material treated and shipped to Texas represents a small fraction of the total mobilized in the river by clamshell dredges. This modest removal has been achieved at the cost of drastically increasing the surface area of contaminated river bottom. We estimate that Phase 1 increased the surface area of contaminated downstream riverbed by at least 3 orders of magnitude, from about 50 dredged acres to many square miles.

Impacts of dredging will increase with increasing surface area of contaminated river bottom. EPA, however, primarily has quantified Phase 1 performance based upon the mass and volume of contaminated dredge spoils removed from hotspots beneath the relatively small Phase 1 dredging area. Hudson River PCB dredging, therefore, is making exposed people into experimental subjects, and riverfront communities into apt subjects of epidemiology studies that may continue for generations to come.

Recommendations

Risks to human health potentially posed by airborne pathways of exposure to PCB under dredging and nondredging scenarios should be assessed objectively and compared via correction of prior EPA assessments before authorization is given to implement Phase 2. Acceptability of risks to human health potentially posed by dredging must be adopted as a precondition for undertaking Phase 2 of the project. Phase 2 also must increase the scope and duration of environmental monitoring to enable more reliable warning of harm in real time, and project evaluation over decades.

Water and air monitoring, including personal monitoring, should occur together at dredge platforms. Results of personal airborne exposure monitoring of GE dredging personnel to PCB should be made available to the public, minus confidential personal information, as has been the case with other project data. Permanent arrays of air and water samplers are needed to verify or refute EPA’s prior safety claims, and to protect public and environmental health. The sources of PCB sheens, and the composition and volume of the possible source pools of PCB, should be investigated and, if possible, their relationship to originally disposed PCB liquids determined. Strategies to manage possibly rich sources of PCB liquids that dredge buckets disrupt and fail to hold must be developed to prevent mobilization of highly concentrated liquid PCB, and assure compliance with the benefit criterion.

Technologies should be considered for use in Phase 2, such as coffer damming, hydraulic dredging, and dredging within enclosures to minimize PCB mobilization, resuspension, and PCB entry into ecosystems and the air. Vacuum dredging, in which water, sediment, and rocks are captured without dispersing fine particles into the water column, may be the best method. The pontoons could be equipped with sedimentation basins in which flocculates that bind fine particulates can be added to the slurry. The slurry then should be filtered on site to return clean water into the river. Alternatively, the pontoons could move their entire load into the treatment plant, where proper treatment can be applied and the water returned to the river.

Note Added in Support

An official Hudson River PCB Dredging Peer Review Panel advisory to EPA released its final report (Peer Review Panel, 2010) approximately two months after we submitted our manuscript to Environmental Practice. The Peer Review

Panel report must be interpreted in light of prohibitive EPA instructions regarding its allowable scope:

The Peer Review panel will not evaluate whether the Remedial Action [dredging] will, or may, achieve the human health and/or environmental objectives of the ROD [EPA's Record of Decision under the Superfund Law], nor will the Peer Review panel evaluate whether Phase 2 should be implemented. (p. 3, emphasis added)

The report nonetheless is informative about these issues, stating implicitly that which it was prohibited from saying explicitly: Phase 2 cannot be completed feasibly and safely in the allotted five-year time frame remaining using available data, models, and criteria for success:

There is a very real need to set an allowable load limit for the Hudson River dredging project, but neither the data nor tool(s) needed to do so currently exist. To that end, the project must develop a set of models that incorporate hydrodynamics, sediment transport, fate and transport of PCBs, and bioaccumulation of PCBs in the Upper Hudson River (from Fort Edward to Troy Dam). (p. 36)

Notwithstanding two decades of EPA planning, prerequisite data and models were lacking at project onset, including the amount of PCB in the river. Further, requisite data were not collected in Phase 1, nor were requisite models developed. Dredging, therefore, might require years longer to be completed safely:

Since the total volume to be removed is not known, it is not reasonable to project what the annual production would be based on a 5-year schedule for Phase 2. (pp. 75, 76)

and, therefore,

the 5-year productivity criterion should be dropped to provide more flexibility to complete the work in a manner that protects the integrity of the project and its risk reduction objectives. (pp. v, 78, emphasis added)

The Panel also found the following:

Phase 1 showed that the 2004 EPS [Engineering Performance Standards] for Resuspension, Residuals, and Productivity were not met individually or simultaneously during Phase 1 and cannot be met under Phase 2 without substantive changes. EPA and GE proposed changes to the EPS but the Panel finds that the new proposed standards from either party would not contribute to the successful execution of Phase 2. (pp. iii, 84, emphasis added)

Notes

1. Calculation: 286,006 cubic yards (yd) of sediment barged in Phase 1, per GE bucket files (Table 2)

Hudson River PCB Dredging 391

X 1.31 m? per yd? = 373,795 m? = 3.74 X 10" cm? barged

X 2.6 g/cm? density = 9.72 X 10" g = 9.72 X 108 kg

= 9.72 X 10° metric tons barged

= 26% (= 0.26) of dredge-disturbed sediments (dredge spoils); 9.72 X 10° metric tons barged/o.26

= 3.7 X 10° metric tons mobilized = 3.7 million tonnes

2. Under the Federal Safe Drinking Water Act of 1974 (amended in 1986 and 1996), water levels are enforced at the MCL, but regulators must strive toward the more stringent MCL goal (MCLG), if feasible. The MCLG is zero for carcinogens such as PCB. That raises the issue of whether, and under what circumstances, permitting dredgingassociated increases of PCB levels in water is legal, even if the increased levels will remain within the 500-ppt MCL.

3. The “many square miles” estimate is based upon EPA and GE monitoring data that show resuspended dredge spoils at sampling locations miles downstream, at which resuspension refers specifically to dredgingassociated increments above the measured predredging background (Figure 2). The northernmost sample location was at Thompson Island, which is about 7 miles downstream of Rogers Island and about 5 miles downstream of the southernmost extent of the dredged area (at Griffith Island). Additional sampling points were further downstream of dredging, most notably including Waterford, about 40 miles downstream. Except for the dissolved and colloidal fractions (about half), resuspended material is subject to settling to the river bottom. Our estimate is conservative because the river bottom area receiving these sediments is many square miles, just counting the 40-mile stretch from the dredged area to Waterford, but it is a lot more considering that the material continues downstream to the Troy Dam and beyond, eventually to New York City and the ocean, over 100 miles downstream. Indeed, according to Key Findings in GE’s Phase 1 Evaluation Report (General Electric, 2010b) “downstream sediment cores of previously sampled areas showed an average increase of three times pre-dredging concentrations. These and other lines of evidence show that dredging caused wide-spread redistribution of PCB-containing sediments on the surface of the river bottom” (p. 77).

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Hudson River PCB Dredging 393

and Health Consequences of Occupational Exposure to Polychlorinated Biphenyls. British Journal of Industrial Medicine 39(4):361-369.

Stehr-Green, P.A., E. Welty, G. Steele, and K. Steinberg. 1986. Evaluation of Potential Health Effects Associated with Serum Polychlorinated Biphenyl Levels. Environmental Health Perspectives 70:255-259.

Taylor, PR., J.M. Stelma, and C.E. Lawrence. 1989. The Relation of Polychlorinated Biphenyls to Birth Weight and Gestational Age in the Offspring of Occupationally Exposed Mothers. American Journal of Epidemiology 129(2):395-406.

United Nations Environment Programme (UN EP). 2003, March. Training manual for the preparation of a national environmentally sound management plan for PCBs and PCB-contaminated equipment in the framework of the implementation of the Basel Convention. Basel Convention Series/SBC No. 2003/01. UN EP, Chatelaine, Switzerland, 103 pp.

US Environmental Protection Agency (EPA). 1999, December. HRA, MidHudson River. Phase 2 Report—Further Site Characterization and Analysis. Volume 2F—A Human Health Risk Assessment for the Mid-Hudson River. Hudson River PCBs Reassessment FS. TAMS Consultants, Bloomfield, NJ, 30 pp. + appendices.

US Environmental Protection Agency (EPA). 2000a, November. Revised HRA, Mid- and Upper Hudson River. Phase 2 Report—Further Site Characterization and Analysis. Volume 2-—A Human Health Risk Assessment; Hudson River PCBs Reassessment FS. TAMS Consultants, Bloomfield, NJ, 128 pp. + appendices.

394 Environmental Practice 12 (4) December 2010

US Environmental Protection Agency (EPA). 2000b, November. Revised HRA, Mid- and Upper Hudson River, Appendix E. Hudson River PCBs Reassessment FS. Appendix E: Engineering Analysis. Section 6. Technical Memorandum: Semiquantitative Analysis of Water Quality Impacts Associated with Dredging Activities. Bloomfield, New Jersey. TAMS Consultants, Bloomfield, NJ, 33-67.

US Environmental Protection Agency (EPA). 2006, updated May 15. Actions Prior to EPA’s February 2002 Rod [Record of Decision]. Fig. 2-2, Hudson River PCB Site History. http://www.epa.gov/hudson/actions.htm.

US Environmental Protection Agency (EPA). 2010a, March, Hudson River PCBs Site EPA Phase 1 Evaluation Report. Prepared for US EPA, Region 2; and US Army Corps of Engineers, Kansas City District. Louis Berger Group, Morristown, NJ, 272 pp. + appendices.

US Environmental Protection Agency (EPA). 2010b, updated October 25. Hudson River Dredging. http://www.epa.gov/hudson.

US Environmental Protection Agency (EPA). 2010c, updated October 25. Hudson River Dredging Data. http://www. hudsondredgingdata.com.

Warshaw, R., A. Fischbein, J. Thornton, A. Miller, and J. Selikoff. 1979. Decrease in Vital Capacity in PCB-Exposed Workers in a Capacitor Manufacturing Facility. Annals of the New York Academy of Sciences 320:277-283.

Submitted July 7, 2010; revised September 22, 2010; accepted October n1, 2010.

Appendix 3

Michaels, Robert A.; and Uriel M. Oko. Excessive PCBs in the Hudson River: attributable to incompleteness of dredging, or to seven years of dredging? Environmental Claims

Journal, 29(2):115-40, 2017; online: http://dx.doi.org/10.1080/10406026.2017.1307007,

25 April 2017

ENVIRONMENTAL CLAIMS JOURNAL,

2017, VOL. 29, NO. 2, 115-140 http://dx.doi.org/10.1080/10406026.2017.1307007

3907 N0Y

Routledge

Taylor & Francis Group

Excessive PCBs in the Hudson River: Attributable to Incompleteness of Dredging, or to Seven Years of Dredging?

Robert A. Michaels? and Uriel M. Oko”

RAM TRAC Corporation; "Recycle Management

ABSTRACT

GE recently completed a seven-year US EPA-mandated clamshell dredging project to remediate PCB contamination of the Hudson River. Post-project PCB levels in water and fish, however, are higher than anticipated, suggesting to some the need to extend the project to remove more PCB-bearing sediments. Our investigation of the effectiveness of the dredging project revealed that a previously unconsidered physical process must mobilize sediments as a result of dredge bucket closure. We also used computerized dredging data (‘bucket files’) to estimate the fraction of dredged sediments returned to the river instead of being deposited into waiting barges. We conclude that excessive post-project PCBs in the Hudson River predominantly are attributable to sediment mobilization by clamshell dredges. We predict that proposed extension of the dredging project would prolong mobilization processes, allowing PCBs to spread widely and enter ecosystems that include people, endangered fish such as sturgeon, and endangered birds such as bald eagles.

Introduction

GE (the General Electric Company) recently completed a seven-year US EPAmandated clamshell dredging project to remediate PCB (polychlorinated biphenyl) contamination of the Hudson River. Post-project PCB levels in water and fish, however, are higher than anticipated, for example in 2016 requiring the New York State Department of Health (NYS DOH 2016) to recommend further restriction of fish consumption. NYS DOH issued a “Don't Eat” fish consumption advisory for walleye fish taken from the Hudson River downriver, between the Rip Van Winkle Bridge at Catskill and the Tappan Zee Bridge. This advisory is more stringent than the previous advisory, which recommended limiting intake of walleye to one meal per month. The current advisory was based upon new data showing elevated levels

of PCBs in these fish.

CONTACT Robert A. Michaels © ram@ramtrac.com; umoko@nycap.rr.com ©3100 Rosendale Road, Schenectady,

NY 12309.

Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/becj.

116 @)_R.A.MICHAELS AND U. M.OKO

In 2007 the U.S. Environmental Protection Agency (US EPA) required GE to remediate the Hudson River PCB Superfund Site via dredging. Also in 2007, we reported pro-dredging bias in the form of errors in US EPAs baseline health risk assessment (HRA) for Hudson River PCBs; indeed, all nine identified errors were made in the dredging-friendly direction rather than randomly (Michaels and Oko 2007). Permissive HRA findings that resulted from these errors constituted a necessary condition for US EPA to conclude that dredging could be accomplished within acceptable health and environmental risk parameters, and to require GE to employ dredging for remediation of the site. The original purpose of site remediation via clamshell dredging was to reduce safely and substantially the long-term downstream transport of PCBs (Peer Review Panel 2010; US EPA 2002).

In 2010 we evaluated dredging Phase 1, consisting of a one-year attempt, in 2009, to demonstrate the feasibility of clamshell dredging as a multiyear remedy for the Hudson River PCB Superfund Site (Michaels and Oko 2010). The 2010 paper reported failure (of GE) to complete a significant fraction of the planned Phase 1 area within the allotted dredging season, and failure (of US EPA) to demonstrate the feasibility of implementing Phase 2 within acceptable environmental and health risk parameters. Similar conclusions were drawn by US EPA’ peer review panel for Hudson River PCB dredging (Peer Review Panel 2010). Others more generally have characterized conventional clamshells as more typically used for navigational rather than for environmental dredging (for example, Bridges et al. 2008; Palermo et al. 2008):

Although conventional dredges normally used for navigation dredging (e.g., conventional clamshells or cutterheads) can be effective for environmental dredging, evolving technologies for dredge and dredgehead designs (e.g., enclosed buckets, articulated fixedarm mechanical, swinging ladder cutterheads, and articulated ladder cutterheads) may offer better performance for environmental dredging. (Palermo et al. 2008, 257; emphasis added)

Accordingly, we recommended consideration of hydraulic dredging as originally proposed, or other alternatives to conventional clamshells (Michaels and Oko 2010). Indeed, US EPA specification of clamshell dredging in the Hudson River is unusual, as most PCB dredging from U.S. waters has relied upon hydraulic dredges, which were used, for example, in the New Bedford Harbor in Massachusetts, the Cumberland Bay in Plattsburgh, New York, and the Fox River in Green Bay, Wisconsin.

Notwithstanding the above, US EPA required GE to initiate Phase 2 in 2011, after a one-year hiatus in 2010 for project evaluation, culminating in our paper (Michaels and Oko 2010) and the peer review panel's adverse report (Peer Review Panel 2010). The scope of Year 1 of Phase 2, in 2011, included completion of the undredged Phase 1 area. As we reported, Phase 1 not only failed but, more fundamentally, it lacked the potential to succeed in demonstrating the feasibility of Phase 2, because Phase 2 posed two problems not posed in Phase 1: (1) dredging in faster-moving water, and (2) confining dredge-disturbed PCB-contaminated sediments to within isolated ‘hot spots; despite river currents capable of carrying mobilized PCB liquids, dissolved molecules, colloids, and suspended particulates downstream to areas in which future dredging was not planned.

EXCESSIVE PCBS IN THE HUDSON RIVER © 17

Phase 1 differed from Phase 2 in being conducted largely at one side (the east side) of Rogers Island, where sediment transport was slowed by a nearby stone dam and sediment curtain. Phase 1 also predominantly involved bank-to-bank dredging. Phase 2 involved widely separated PCB hot spots and faster moving open river water. Redeposition of mobilized PCB-containing sediments in the Phase 1 area was followed generally by redredging, thereby minimizing the impact of dredge-disturbed sediment flow and mobilization beyond the dredging zone. Thus, US EPA’ authorization to conduct Phase 2 based upon Phase 1 constituted a non sequitur.

Failure of Phase 1 to meet engineering performance standards (EPSs) and health risk criteria (Peer Review Panel 2010) was ominous for Phase 2 (Michaels and Oko 2007, 2010; Peer Review Panel 2010). Implementation of Phase 2 for two years, in 2011 and 2012, and its continuation in 2013 and for years thereafter until completion, together raised five emerging and unique issues that we evaluate here, including the following:

1. Sediment mobilization: US EPA accuracy in estimating PCB-contaminated sediment mobilized by dredging;

2. PCB mobilization: Possible PCB loss by desorption from resuspended sediment particles;

3. Storms: Possibly changing frequency of sediment-mobilizing high-flow events;

4. Endangered species: Endangered species classification of Hudson River sturgeon and bald eagles; and

5. Autism: Progress of research into possible PCB causation of autism.

Methods

Our investigation included reviewing literature, making site visits, attending meetings, and evaluating several exposure and toxicology issues. We conducted three site visits to observe and photograph dredging, each time visiting US EPA’ field office in Fort Edward, interviewing US EPA and GE personnel and contractors, analyzing dredging data, attending public meetings, and examining scientific and regulatory documents (for example, Harza 1992; NYS DEC 2000, 2003; PSEG NY 2001; Shavit, et al. 2003; UN EP 2003, and other sources in References). Our analysis adopts methods of health risk assessment (HRA), critical evaluation of projectrelated scientific information sources (for example, GE 2009, 2010a, 2010b, n.d.; US EPA 1999, 2000a, 2000b, 2001, 2006, 2010a, 2010b, 2010c, 2010d, 2010e, 2012, n.d.a, n.d.b), and objective scientific peer review. The latter are not a priori methods, and they are not described in detail here. Rather, they consist of diverse methods that are generally typical of peer review by scientists seeking to remain objective. Most essentially, these methods consist of our own disciplined, critical evaluation of the scientific merit with which numerous methods were selected for use and applied prior to dredging, during dredging Phase 1, and during Phase 2.

The scope of our assessment therefore includes our own peer review of GE and US EPA methods, findings, and conclusions, such as those reported orally in public meetings, and in written public communications on GE (n.d.) and US EPA (n.d.a,

118 @)_R.A.MICHAELS AND U. M.OKO

n.d.b) Web sites for Hudson River dredging, and more formally in GE (2009, 2010a, 2010b, app. GE (2009, 2010a, 2010b) and US EPA (1999, 2000a, 2000b, 2001, 2006, 2010a, 2010b, 2010c, 2010d, 2010e, 2012) draft and final reports published for consideration by the public, specific interested parties, and members of the Hudson River dredging project peer review panel (Peer Review Panel 2010). Members of the public and other readers of our assessment can judge for themselves whether and to what degree we succeeded in applying the methods of HRA and of peer review objectively. We hope that we have done so completely.

Findings

General

Mobilization of dredge-disturbed sediment was > 100 times higher than measured by US EPA’ engineering performance standard (EPS) for resuspension, and no EPS exists to detect, quantify, or reduce downstream sediment redeposition. Much PCB adsorbed to dredge-disturbed sediment desorbs within minutes of mixing into river water. This fugitive molecular and colloidal PCB is transported downstream, but missed in routine resuspension monitoring. Complicating matters, the frequency and intensity of storms is increasing. Invisible to EPSs, storms may scour fugitive PCB-contaminated sediment, and transport it downstream gradually and episodically, over years or decades. Long-term downstream transport of PCB poses risks to endangered species, possibly including extirpation of sensitive sturgeon from the Hudson River. Finally, recent animal research links PCBs to developmental processes that, in humans, are thought to underlie autism causation, but US EPA has failed to address potential autism risks.

Issue 1, sediment mobilization: US EPA accuracy in estimating PCB-contaminated sediment mobilized by dredging

Sediment mobilization by dredge jaw closing. Sediment resuspension arising from bucket (clamshell) dredging is reported to “result from the impact, penetration, and removal [of the dredge bucket] from the bottom sediments; leakage while raising it through and out of the water column; and washing during movement through the water column” (Zappi and Hayes 1991, citing Barnard 1978). Resulting “suspended solids in the area of influence of the bucket dredge, without hopper barge overflow, can range from 20 to 1,100 mg/L’ (Zappi and Hayes 1991, citing McLellan et al. 1989). A process contributing to sediment mobilization that apparently has been neither addressed nor described previously is generation of a suction force behind closing dredge jaws.

EXCESSIVE PCBS IN THE HUDSON RIVER (e) n9

Figure 1. Hudson River dredge showing bucket suspended beneath superstructure.

a rigid nonsolid steel superstructure (Fig. 1). The jaws of a typical 5-cubic-yard (3.85-cubic-meter) bucket used in the Hudson River each have an open crosssectional area of 88 square feet (9.8 square meters) measuring 7.1 feet (2.2 meters) in width and approximately 4.4 feet (1.3 meters) in height, producing a solid crosssectional area of >30 square feet (3 square meters). The superstructure adds another 6 feet (1.8 meters) of height, producing a total of over 10 feet (3 meters).

The total cross-sectional area that moves through river water during closing of each dredge jaw therefore is approximately 50 square feet (4.6 square meters), most of it above river sediment grade (typical dredge jaw penetration depth is up to 1.5 feet (0.5 meter), visible as the abraded area at the bottom of the bucket depicted in Fig. 1). The angle of attack changes (becomes more vertical) as the bucket closes and, of course, the velocity of jaw movement through the water is greatest toward the bottom, which also is the solid portion of the dredge bucket.

As the bucket jaws close, physics requires that they create three strong currents. One current results from compression of water and sediment situated between the closing bucket jaws. It forces water and sediment out of the dredge bucket. The other two currents result from suction of water and sediment situated in the reducedpressure zone behind each dredge jaw. These latter two currents exert a force that drags water and sediment, causing them to follow behind moving dredge jaws as they close. All three forces create turbulence. The compressive force, especially because it drives water and sediment upward through the open top of dredge jaws,

720 ©) R.A.MICHAELS AND U.M. OKO

produces turbulent eddies of sediment typically extending to the river surface, readily visible and varying from gray to black, depending upon location in the river.

The inward-directed suction force exerted in the reduced-pressure zone behind the dredge jaws acts on water much as a moving vehicle acts on air. This force is manifested (for example) by race cars drafting close behind another car to accelerate by using the powerful suction force created by the lead car’s evacuation of air behind it. The suction force also is made visible as opaque diesel exhausts flow over the tops of moving trucks and are sucked turbulently downward in the trailing low-pressure zone. Physics demands that loose or uncompacted sediment situated outside each opposing jaw of dredge buckets likewise must be sucked off the river bottom during bucket closure. The swirling sediment then is left in the river as the dredge buckets are lifted to the surface and beyond.

Sediment mobilization is quantified by comparison of sediment volumes placed in barges with sediment volumes dredged in each bucket closure. Bucket closures are recorded automatically via computers on board dredge platforms, and published as the ‘bucket files’ (GE 2010b; Michaels and Oko 2010; US EPA 2010a). Sediment that is mobilized behind closing dredge jaws, however, is routinely not quantified in the bucket files, because such sediment is not dredged and not placed in barges. For example, consider a typical five-cubic-yard dredge bucket that penetrates to a sediment depth designed to fill it to 80 percent of full capacity. Its field capacity would be four cubic yards (0.85 cubic yards). If only two of the four cubic yards are barged, by subtraction the inferred mobilization also is two cubic yards, or 50 percent of field capacity.

The mobilization fraction calculated as above excludes turbulent sediment mobilization due to suction generated by each closing dredge jaw. Accordingly, the actual mobilization fraction is higher by the amount disrupted outside each dredge bucket jaw. Physics demands that the compressive force exerted to the interior of dredge bucket walls equal the suction force exerted outside. A reasonable approximation, therefore, is that uncounted sediment mobilization outside dredge buckets roughly equals the amount of sediment that is mobilized within buckets. This approximation also is conservative, inasmuch as the sediment that can be mobilized includes that situated behind each of two dredge jaws. This added mobilization factor gives rise to the possibility of the sediment mobilization fraction exceeding 100 percent of the dredge bucket field capacity. That is, dredge buckets cannot mobilize more sediment than they contain, unless (as described above) they also mobilize sediment that they do not contain.

Estimation of sediment mobilization fraction. We previously made two independent quantitative estimates of the fraction of sediment mobilized when a dredge bucket descends to the river bottom, closes, lifts its load, and transfers its load to a waiting barge (Michaels and Oko 2010). One estimate, based upon the difference between sediment volume enclosed by an open versus a closed dredge bucket, was a mobilization fraction of approximately 80 percent. The other, based upon analysis of published bucket files versus published barged-sediment data, was approximately

EXCESSIVE PCBS IN THE HUDSON RIVER [e) 121

75 percent during Phase 1, Year 1. These values exclude consideration of the new factor described above, i.e., suction creating turbulence behind closing dredge jaws.

A related factor, likewise unquantified (in Michaels and Oko 2010, and also herein), is failure of bucket closure, that is, turbulent mobilization of sediments by descending dredge jaws that cannot close when they encounter obstacles on the river bottom (such as bicycles, automobile tires, logs, boards, rocks, concrete blocks, rebar, and other construction debris). When dredge buckets fail to close, the onboard computer does not record the data in the bucket files. Indeed, for this reason, the fraction of bucket descents that result in nonclosure is unknown, notwithstanding that these bucket descents mobilize sediment in the river. Most essentially, notwithstanding our inability to quantify some parameters precisely, the factors described above, along with bucket geometry and computerized bucket data, indicate that dredge buckets dumped more material back into the river than into waiting barges. That material remains mobile via physical processes or, if taken up by biota, through ecosystem dynamics.

The two factors described above, though we cannot quantify them exactly, at the least add conservatism to our previously published estimates of 75-80 percent sediment mobilization per bucket closure. This fraction was applicable to dredge buckets, but was significantly (but likewise to an unquantified degree) reduced when considering overall sediment mobilization in Phase 1, because of bank-to-bank dredging. Such redredging in Phase 1, however, is not a feature of Phase 2 (except in its first year, 2011, which included bank-to-bank dredging of the uncompleted Phase 1 area), because Phase 2 addresses widely spaced PCB hot spots. Sediments that are resuspended and carried downstream beyond a PCB hot spot may redeposit on a portion of the river bottom that will never be dredged (or redredged). Phase 2 hot spot dredging comprises the preponderance of the forty-mile (sixty-four-kilometer) stretch of the Upper Hudson River that is included in the dredging project, making the per-bucket mobilization fraction highly relevant for Phase 2. Given the preponderant scope of Phase 2, the per-bucket mobilization fraction is relevant in evaluating the Hudson River dredging project in its entirety.

Issue 2, PCB mobilization: Possible PCB loss by desorption from resuspended sediment particles

Estimation of PCB mobilization fraction. Apart from the sediment mobilization fraction addressed above is the related issue of the possibly different PCB mobilization fraction. PCB might be mobilized by desorption from dredge-disturbed sediment as particle surfaces encounter relatively PCB-free river water. To the degree that this occurs, PCB may be mobilized from dredge-disturbed sediment as it falls back to the river bottom or remains suspended (resuspended) in the water column. Such desorption produces free PCBs in the molecular and colloidal phase, which are transported downstream with river water. Free PCB in river water no longer is adsorbed to clay or silt particles. Sampling of clay or silt particles in routine resuspension monitoring would not capture free PCBs in dissolved or colloidal form.

122, ©) RA.MICHAELS AND U.M. OKO

“PCB in colloidal form constitutes the most mobile form of PCB in water, being affected only minimally by settling, physical retention or adsorption” (Paquin 2001).

To develop a more realistic picture of resuspension, we estimate, roughly but quantitatively, the amount of fugitive free PCB that clamshell dredging might have created in Phase 2. Fugitive PCB originates, and primarily is carried by, fine particles of silt, clay, and sand that, together, give rise to free PCB via desorption. Accordingly, we used data on hydraulic dredging to derive information on the size distribution and resuspension of such sediment in moving water like the Hudson River. Available literature (Nau-Ritter et al. 1982) indicates that approximately 30 percent of PCB adsorbed to resuspended sediment particles desorbs and enters river water in dissolved or colloidal form within minutes of resuspension. Further, most fine particles (‘fines’) remain resuspended for hours to weeks before settling, during which they slowly release most if not all of the remaining 70 percent of adsorbed PCB (Schneider 2005). We assume that much or most of the 70 percent is captured by routine resuspension monitoring. The 30 percent that quickly enters the aqueous phase, however, would not be captured in routine particle monitoring for verification of compliance with US EPA’ EPS for resuspension.

The mass of PCB corresponding to loss of 30 percent desorbed from particles of dredge-disturbed sediment to the aqueous phase is missed in monitoring PCB concentration in water, due to river flow variation. We approximate it as follows. We do not know the exact size distribution of resuspended particles, but laboratory development of a dredging elutriate test (DiGiano et al. 1995) revealed that turbulence mixes a wide range of particle sizes into the water column, but denser particles settle preferentially, leaving behind an elutriate (supernatant) of less dense resuspended particles, of which 90 percent were < 10-m (micrometer, or micron) diameter. The most common size class was 4 1m. Accordingly, we similarly assume spherical particles of diameter 4 1m. Although the particles are resuspended, we assume a heavier-than-water specific gravity of 1.8, which, as they are small, can be maintained in suspension by turbulence in river water. This specific gravity is somewhat lower than 2.6 previously reported for Hudson River sediments (Gruendell 1966; Michaels and Oko 2010), as we also assume here that relatively lighter resuspended particles are enriched in relatively less dense organic matter.

Our 4-1m spherical particle model is only a rough guide. Fine particles resuspended after dredge disturbance actually are nonspherical, and some are more porous than others, whereas we assume hard spheres. Both properties increase surface area. For example, clay, an important constituent of silt, is both porous and nonspherical, with particle surface areas of 200-600 m?/g (square meters/gram). Our hard-sphere model therefore is conservative, because porous-nonspherical particles have more surface area, can adsorb more PCB, and thus can desorb more PCB to river water.

The high surface area of small sediment particles such as clay disproportionately carries resuspended PCB (DiGiano et al. 1995; Anchor Environmental 2003; Michaels and Oko 2010). We assume that each resuspended hard-spherical particle is coated initially with a monolayer of PCB molecules. We also assume an average

EXCESSIVE PCBS IN THE HUDSON RIVER © 123

Table 1. PCB desorption from resuspended sediment in ten-acre Phase-1 Year-1 Hudson River dredg-

ing area.*

Mass of PCB rapidly desorbed from a resuspended spherical sediment particle of diameter four microns

radius of 4-micron (um) diameter spherical particle 2 um

surface area of spherical particle of 4-m diameter: 4 2 2 503 sq.m

area occupied by one molecule of (decachlorinated) PCB 300 sq. angstroms

area occupied by one molecule of (decachlorinated) PCB 3.00 E-06 sq. um

PCB molecules in monolayer on one 4-11m-diameter particle 1.68 E+07 PCB molecules

molecular weight (MW) of the PCB molecule 240 g/mole

number of PCB molecules per mole (Avogadro's number) 6.02 E+23 PCB molecules

moles of PCB monolayer adsorbed to 4-1.m diameter particle 2.78 E-17 moles

mass of PCB molecules on one 4-m diameter particle 6.68 E-15 g

fraction of PCB rapidly desorbed and entering river in aqueous Phase 03 wee

mass of PCB rapidly desorbed to water, per 4-11m diameter particle 2.00 E-15 g/0.04-11m particle Mass of a resuspended spherical sediment particle of diameter 4 microns

volume of spherical particle of 4-um diameter: 4/3 x P 3.35E+01 cu. um

conversion, cubic jm to liter (= 1,000 cu. cm) 1.00 E-15 cu. um/liter

volume of spherical particle of 4-um diameter: 4/3 x P 3.35E-14 liters

specific gravity of 4m diameter spherical particle 18 g/mL = kg/liter

conversion, g/mL to g/cu. m 1.00 E-06 (g/cu. m)/(g/mL)

specific gravity of 4-1m diameter spherical particle 1.80 E+06 g/cu.m

mass of spherical particle of 4-m diameter 6.03 E-14 kg/0.04-1m particle

mass of spherical particle of 4m diameter 6.03 E-11 g/0.04-11m particle

Number of spherical sediment particles of diameter four microns fitting into a five-cubic yard dredge bucket

conversion, cubic yards to cubic meters 7.65 E-01 volume of 5-cubic yard dredge bucket 3.82 E+00 field capacity if filled to 80 percent of full capacity 3.06 E+00 volume of spherical sediment particle of 4-1m diameter 3.35E+01 conversion, cubic jum to cubic m 1.00 E-18 volume of spherical sediment particle of 4-1m diameter 3.35 E-17 no. of 4-m spherical sediment particles per 5-cubic yard bucket 9.13 E-+16

cu. m/cu. yd. cum

cum

cu. um

cu. m/cu. um. cum particles/bucket

Allowable resuspension in ten-acre Phase-1 Year-1 dredging area, under US EPA's 2 percent-EPS

mass of sediment particles per 5-cubic yard dredge bucket 5.50 E+03 US EPA engineering performance standard (EPS) for resuspension 2 allowable resuspended particle mass, in accordance with EPS. 10.1 bucket closures in ten-acre area dredged in Phase 1 Year 1 221,521 allowable resuspended particle mass, in ten-acre Phase-1 Year-1 area 2.44 E+07

percent

kg/5-cu. yd. bucket closures/10 acres kg/10 acres

Mass of PCB rapidly desorbed to water from resuspended particles in ten-acre Phase-1 Year-1 area

4-um diameter spherical particles per gram 1.66 E+10 4-um particles resuspended in ten-acre Phase-1 Year-1 area 4.04 E+20 mass of PCB adsorbed as monolayer on resuspended particles 2.70 E+03 mass of PCB rapidly desorbed from resuspended particles 8.10 E+-02

particles/gram particles

kg of PCB adsorbed kg of PCB desorbed

Scientific notation: 1.00 x 10“" tabulated as 1.00 E-+01.

PCB molecular weight of 240 grams/mole. Table 1 (above) shows the following cal-

culated parameter values:

1. the mass of a monolayer of PCB on a 4-um spherical particle is 2.00x 10~!°

2. the mass ofa particle of 4-1m diameter and specific gravity 1.8 is 6.03 107!

3. an 80 percent-full 5-cu. yd. dredge bucket can contain 9.13x10!® 4-um

particles;

124 ©)_RA.MICHAELS AND U.M. OKO

<resuspension at dredgehead os (%) 2057 BS a 8 & 000 3 ae 2 3 E 2000 9 resuspension projections (Excel file at sew HudsonDredping.com; goto Scien [Reports sro to River Model Output Data). iss “The 2% arfow is interpolated, t show US EPA enginearing performance stander as revised fr Phase 2.

° ¥ LISP IS PIPPI PIE LIS FF PPP PF GPP

Figure 2. At Waterford: GE projected years needed to match no-dredging, assuming zero dredge mobilization of PCB other than ‘resuspension’

4. US EPAs 2 percent-EPS allows resuspension of 2.44x 10” kg in the ten-acre Phase 1, Year 1 dredging area; and 5. the estimated mass of PCB desorbed to the river in aqueous phase is 810 kg. GE estimates show that the break-even point, at which dredging will have reduced PCB mobilization as much as it has increased it during the dredging project, would be twenty years, assuming compliance with US EPA’ 2 percent-EPS for resuspension. This would bring the break-even year to 2032 (Fig. 2). Under GE’s highest mobilization assumption, 5 percent of sediment is released back to the river “at the dredgehead,’ in which case dredging will require forty-six years to match the effectiveness of the no-action remediation alternative. That is, no benefit can be expected until the year 2057 at the earliest, optimistically assuming no delays and, critically (see Discussion), no mobilization of PCB sediments other than ‘resuspension’.

Issue 3, storms: Possibly changing frequency of sediment-mobilizing high flow events

After the first season of dredging, GE reported (Carson 1962; DiGiano et al. 1995; Gardiner et al. 1996) that sediment samples outside the dredged area “show that dredging caused wide-spread redistribution of PCB-containing sediments on the surface of the river bottom.” High-flow events already have driven some of this dredge-mobilized sediment downstream (see, e.g., Islam et al. 2012, 24). Indeed, recent years have evinced a trend toward increasing frequency and intensity of storms (Matonse and Frei 2012, 25), including extreme events such as Hurricane

Katrina in 2005, Irene in 2011, and Sandy in 2012, all attaining extraordinary energy, largely from warmer ocean water in their path (see, e.g., Trenberth 2007).

EXCESSIVE PCBS IN THE HUDSON RIVER © 125

Evident global climate change (whatever may be the less-well-known contribution of civilization to it) has been manifest in a concomitant trend toward more frequent high-flow events in rivers and streams, resulting from rainfall, tidal surges, and flooding. Indeed, Matonse and Frei (2012) investigated whether the hydrological impacts of Hurricane Irene and Tropical Storm Lee continue a historical trend toward increasing frequency of extreme hydrological events in New York State’s Catskill Mountains and Hudson River Valley region. They found

a marked increase in the frequency of extreme hydrologic events during the last one to two decades. This increasing trend is more evident during the late summer and early fall, the season of the most extreme precipitation events.

This trend, therefore, can be extrapolated to the future, and incorporated into Superfund remediation project assumptions, including assumptions for Hudson River PCB dredging.

Tropical Storms Irene and Lee caused 100-year and 500-year flooding, in which the Mohawk River carved new channels up to forty-five-feet deep. The storms exerted comparable impacts on the Hudson River. For example, the storms delivered an extraordinary amount of fresh water to the Hudson River watershed, along with a U.S. Geological Survey (USGS) estimate of nearly three million tons (2.7 x 10° kg) of sediment (Wall and Hoffman 2012, 18).

Potential effects of swift river flow include scouring of PCB-laden sediment exposed by dredging to downstream areas, washing away of plantings designed to stabilize the river bottom and reestablish ecosystems, disruption of caps placed over residual PCB-containing sediments, flooding, and depositing PCB sediment on the shore as ‘flood mud? Islam et al. (2012, 17), investigating the impact of Tropical Storm Irene-associated precipitation on the Hudson River and estuary ecosystem, reported the following:

Continuous monitoring data at the PCB superfund site at Fort Edward, NY ...showed significant and coincident increases in sediment flux (22 metric ton/hr to 2400 metric ton/hr) and stream flow (85 m/s to 480 m/s) following Irene. In addition, in-situ particle size measurements suggest that significant amounts of small particles (<70 jm diameter) were transported during the flood event.

Moreover, the contribution of these extreme storm effects to the overall loading is comparable to that of long-term sediment transport under ordinary conditions. This suggests that effects of episodic events should be considered as part of ecosystem management during activities such as navigational channel dredging, remediation projects, and long-term water usage and discharge control.

Issue 4, endangered species: Endangered species classification of Hudson River sturgeon

US EPA reported that PCB concentrations in fish tissue in the Upper Hudson River increased fivefold after the first year of dredging (US EPA 2010a, 2010e, 2012, n.d.a, n.d.b). US EPA reported more recently that PCB concentrations in fish tissue in the Upper Hudson River sampling area have returned to normal, presumably due to a combination of contaminated sediment removal and downstream transport

126 ©) _R.AMICHAELS AND U.M. OKO

of residuals (Id. 2010e, 2012, n.d.a, n.d.b). Indeed, US EPA’s Hudson field office director David King acknowledged orally at a conference at Marist College (January 16, 2013) that twenty to thirty years might be required for PCB levels in fish tissue to decline again to levels safe for human consumption. Resuspended PCB transported downstream is assumed (by us and by US EPA) eventually to reach the Lower Hudson River, which is the principal habitat of two species of sturgeon (Shepherd 2006; USDOC 2012). Indeed, such transport is more than theoretical, but has been documented empirically. Hudson River Natural Resource Trustees reported (NYS et al. 2013) that PCB transport (mostly prior to dredging) already has resulted in PCB contamination of the Lower Hudson River:

The Hudson River Natural Resource Trustees are conducting a natural resource damage assessment (NRDA) to investigate natural resource injuries that may have occurred due to the release of polychlorinated biphenyls (PCBs) from General Electric (GE) facilities at Hudson Falls and Fort Edward, NY. This report summarizes available information on PCB contamination in the Hudson River ecosystem, including historic information, but focusing particularly on data collected and analyzed between 2002 and 2008 as part of ongoing NRDA activities. The Hudson River, for greater than 200 miles below Hudson Falls, NY, is extensively contaminated with PCBs. Surface waters, sediments, floodplain soils, fish, birds, wildlife, and other biota are all contaminated with PCBs. (NYS et al. 2013, 1; emphasis added)

The shortnose sturgeon (Acipenser brevirostrum) was listed as endangered in 1967, though (in 2006; Shepherd 2006) it appeared to be recovering inasmuch as it has not been a target of fishing since 1967. The U.S. Department of Commerce, on February 6, 2012, added the Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) to the Endangered Species List (US DOC 2012). The Commerce Department must protect sturgeon habitat—principally the Hudson River (Shepherd 2006)—as required by the federal Endangered Species Act. Loss of habitat is a big part of the problem of loss of sturgeon, inasmuch as the principle alternative loss factor, fishing for either species of sturgeon, has been prohibited for well over a decade, since a moratorium on harvesting wild Atlantic sturgeon was imposed in 1998 after decades of overfishing. Commercial landings of Atlantic sturgeon crashed before the moratorium was imposed (Fig. 3; Shepherd 2006). The Lower Hudson River, below the Federal Dam at Troy, evidently will be impacted by PCBs for years or decades as contaminated dredge-mobilized sediments are scoured and transported downstream from an increasing area of river bottom in the Upper Hudson River, at Fort Edward and to the south.

Early life stages of sturgeon including larvae and eggs—caviar—are particularly susceptible to PCB contamination (US EPA 2010c). According to US EPA (previous to the official Endangered Species classification of the Atlantic sturgeon): “Fragile populations of threatened and endangered species in the Lower Hudson River, represented by the bald eagle and shortnose sturgeon, are particularly susceptible to adverse effects from future PCB exposure.”

By “future PCB exposure” US EPA (2010c) meant future exposure if dredging does not occur, but dredging did occur. PCB levels in Lower Hudson River water presumably will vary over space and time as they increase gradually to an

EXCESSIVE PCBS IN THE HUDSON RIVER [) 127

Metric Tons

1920 1930 1940 1950 1960 1970 1980 1990 2000 Year

Figure 3. Total commercial landings of Atlantic sturgeon in the United States historically.

Source: G. Shepherd. 2006. Status of fishery resources off the northeastern United States. Atlantic and shortnose sturgeons: Atlantic (Acipenser oxyrhynchus), shortnose (Acipenser brevirostrum. National Oceanic and Atmospheric Administration (NOAA), Northeast Fisheries Science Center (NEFSC), Resource Evaluation and Assessment Division, http://www.nefsc.noaa.gov/sos/spsyn/af/sturgeon/

undetermined maximum over a period of years or decades, during which annual sturgeon reproductive cycles will be stressed. The degree of stress, and ability of already-stressed sturgeon populations to withstand it, both remain unknown.

Modeling of the dynamics of three million tons of sediment loading into the Hudson River following Tropical Storms Irene and Lee, undertaken by Ralston, Geyer, and Warner (2012, 11), revealed the following:

The simulated sediment transport showed surprisingly little sediment export—most of the sediment delivered by the storms was trapped in the tidal river north of West Point, according to the model.

Similar dynamics may be expected from PCB-bearing sediments mobilized by dredging. That is, estuaries can trap sediments and the toxins that they harbor, to the detriment of ecosystems including Hudson River sturgeon occurring below the Federal Dam at Troy.

Issue 5, autism: Research into possible PCB causation of autism

PCBs are known neurotoxicants (ATSDR 2000). Moreover, PCBs have been implicated in causation of Parkinson’s disease (Goldman et al. 2016), ADHD (Keil and Lein 2016), and autism ((Keil and Lein 2016; Landrigan et al. 2012; Wayman et al. 2012a, 2012b). PCBs also are known developmental neurotoxicants at environmental levels of exposure (ATSDR 2000). Based upon prospective epidemiology studies, maternal exposure to PCBs during pregnancy has been linked to dyslexia, attention deficit hyperactivity disorder (ADHD), and loss of cognition (reduced IQ; Winneke 2011). More recent (animal) studies now link PCBs to DNA methylation (Keil and Lein 2016) and to specific developmental processes that, in humans, are thought to

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1in 110 Autism Prevalence On The Rise*

There has been a 600% increase in prevalence cover the last two decades.

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underlie causation of autism (Landrigan et al. 2012; Wayman et al. 2012a, 2012b), most notably the following:

1. stimulation of calcium signaling in the brain that alters nerve cell dendrite

branching; 2. increased dendrite growth and branching; and 3. alteration of synapse formation in developing brains (in animal bioassays). The prevalence of autism has been increasing dramatically in recent decades

(Fig. 4; Autism Speaks n.d.), and today affects 1.13 percent of children (one of eightyeight; Autism Speaks n.d.; Landrigan et al. 2012; USDOH 2012) and nearly one of fifty-four boys (Autism Speaks n.d.). A substantial portion of the increase in autism prevalence evidently is attributable to environmental factors. Boys are nearly five times more likely than girls to have autism (Autism Speaks n.d.), suggesting sexlinked inheritance of susceptibility factors, as boys have just a single (maternal) X chromosome that, if damaged, lacks potential compensation from genes in a counterpart (paternal) X chromosome as is the case in girls, who inherit an X chromosome from each parent.

Discussion, conclusions, and recommendations

Issue 1, sediment mobilization: US EPA accuracy in estimating PCB-contaminated sediment mobilized by dredging

US EPAs engineering performance standard (EPS) pointedly refers to “resuspension,’ not “mobilization” These terms might seem intuitively synonymous but,

EXCESSIVE PCBS IN THE HUDSON RIVER [) 129

in US EPA parlance, resuspension denotes just a miniscule fraction of dredgemobilization of sediment. A significant sediment mobilization discrepancy therefore exists between sediment that is mobilized by dredging versus the much smaller amount of sediment that is measured and reported by GE, and used to document compliance with the US EPA resuspension EPS. The discrepancy arises from the fact that the preponderance of dredge-resuspended sediment falls back to the riverbed, and remains on the river bottom, still mobile, but unrecorded by GE or US EPA because its resuspension typically is episodic over years to decades and, in the main, has not yet occurred.

US EPA (2010d, 2010e, n.d.a) EPSs limit dredge mobilization of sediments to a maximum of 2 percent “at the dredgehead.” Results of US EPA modeling using HUDTOX, however, clearly indicated that the 2-percent EPS, even for resuspension alone, could not be attained at the dredgehead; indeed, it was redefined upward simply by changing (at least doubling) the estimated mass of PCB to be dredged (and also the allowable resuspension fraction), and therefore the amount (mass) of allowable PCB resuspension:

[The Record of Decision] originally estimated the PCB mass to be removed as approximately 70,000 kg, and the total project cumulative load standard was set at just below 1 percent of this total, or 650 kg. Based on the Phase 1 experience and additional sampling results, the estimated PCB mass for the entire project has been revised to the range 140,000 to 200,000 kg. (US EPA 2010d, 4-2).

The sediment mobilization problem also was highlighted by US EPA’s Hudson River Dredging Peer Review Panel. The panel’s initial draft report (Peer Review Panel 2010), published to elicit comments, made an interesting error that was followed by a more interesting response by US EPA. The panel’s comment no. 6 stated the following:

[EPA’s] incomplete analysis done for the 2004 EPS does not consider near-field and far-field PCB deposition rates on the sediment bed surface.

Thus, according to the peer review panel, US EPA failed to consider sediment mobilization at the dredgehead (“near field”), where dredged sediments are mobilized. US EPA's response to Hudson River Dredging Peer Review Panel comment no. 6 is highly informative regarding this issue, and exemplifies US EPA's worst practice in handling data that might interfere with Agency plans:

EPA did simulate near-field suspended matter transport and settling in its near-field modeling analysis. The HUDTOX model runs did not reflect the near-field settled solids but did incorporate an estimate of dredging-related suspended solids transport 1,000 meters downstream of the dredge. This analysis was the basis for the EPA forecasts of dredging-related resuspension. (US EPA 2010b; emphasis added)

Thus, US EPA apparently could not meet the 2-percent (originally 1-percent) EPS limit at the dredgehead, so it declined to apply its HUDTOX modeling results at the dredgehead to forecast dredging-related resuspension quantitatively. Instead, US EPA applied results obtained from HUDTOX at a cleaner place in the river,

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1,000 meters downstream of dredging. Inasmuch as nearly all dredge-disturbed sediment (orally reported by US EPA at roughly 99 percent) falls back to the river bottom near the dredgehead, the use of HUDTOX results from 1,000 meters downstream ignores roughly 99 percent of resuspension occurring at the dredgehead. This is at best misleading and, indeed, the expert peer review panel was misled as indicated by its incorrect criticism (quoted above) that US EPA had failed to model resuspension at the dredgehead (in the “near field”). The Agency did do the modeling, but (as US EPA stated) declined to use the results.

As explained, sediment mobilization via dredging includes resuspension (at the dredgehead or wherever estimated) as well as the preponderance of dredgedisturbed sediment that falls back to the riverbed and is not barged (which we approximated conservatively at 75-80 percent of the amount initially excavated). This sediment drops back to the river bottom, still mobile, but it is excluded from US EPAs resuspension parameter. US EPA’ statement quoted above therefore shows that the Agency justified dredging by ignoring gradual erosion from the river bottom of dredge-mobilized PCB-bearing sediments, which reasonably would be expected to occur over a period of years to decades. The Agency thereby also ignored inevitable, though gradual, entry of PCBs from these sediments into downstream water, ecosystems, and air. Thus, in fifty years US EPA conceivably might find the river to be in much the same condition from GE dredging up sediments today as it was found to be fifty years ago from GE disposal of PCB into the river.

The modeling and data handling issues raised above presumably would have come under scrutiny by US EPA Hudson River PCB Dredging Peer Review Panel, but US EPA explicitly prohibited the panel from opining whether dredging should continue, or whether Phase 2, if undertaken, could meet project health goals. Nonetheless, the Peer Review Panel (2010) rejected US EPAs response, quoted above, concluding in its final report:

Phase 1 showed that the 2004 EPS [engineering performance standards] for Resuspension, Residuals, and Productivity were not met individually or simultaneously during Phase 1 and cannot be met under Phase 2 without substantive changes. EPA and GE proposed changes to the EPS, but the Panel finds that the new proposed standards from either party would not contribute to the successful execution of Phase 2. (Id., 84)

The sediment mobilization discrepancy discussed above represents more than merely a difference between a predicted versus a measured parameter value. It represents a fundamental inconsistency in US EPAs past justification of the need to dredge versus US EPAs current characterization of the performance of the dredging project. The need for dredging was justified by the observed, persistent mobility of PCB sediments requiring, according to US EPA, their removal via dredging. In contrast, in the new context of actual dredging, US EPA dramatically has altered its concept of mobility. Mobility in the dredging project is newly quantified by the miniscule fraction of mobilized (resuspended) PCB that is detected at significant distance downstream. Thus, US EPA has ignored nearly all sediment and PCB mobilization in

EXCESSIVE PCBS IN THE HUDSON RIVER (e) 131

evaluating compliance with the engineering performance standard for resuspension. In ignoring mobility of PCB-containing dredge-mobilized sediments for gauging compliance with the resuspension EPS, US EPA has ignored a much larger degree of PCB sediment mobility than that which constituted US EPA's most essential basis for requiring, in 2007, remediation of the Hudson River PCB Superfund Site via dredging.

Failure of US EPA to use HUDTOX modeling results at the dredgehead is not the only example of misleading use of modeling or monitoring data by US EPA, and should be viewed in this broader context. One example will suffice. In seeking to justify dredging, US EPA had prepared a baseline health risk assessment (HRA; US EPA 1999, 2000a, 2000b) that excluded all mono- and di-chlorinated PCB congeners based upon a misleading premise, specifically, that these congeners do not bioaccumulate in fish tissue, which contributes to human exposure to PCBs (Michaels and Oko 2007). The mono- and di-chlorinated congeners, even if they bioconcentrate less dramatically than the higher-chlorinated congeners, still are present in fish tissue. They should have been present in the HRA.

In the 1960s, Rachel Carson's Silent Spring (1962) famously raised awareness of environmental risks posed by DDT, which is a nearly identical twin of PCBs (Michaels and Oko 2010). Both DDT and PCBs contribute to human health risk by entering air, water, and ecosystems that include food chains terminating in consumption of fish and birds by people. Higher-chlorinated PCBs degrade via dechlorination, resulting in build-up of the mono- and di-chlorinated congeners. Their omission from US EPA’ HRA, therefore, contributed significantly to obtaining its dredging-permissive results. Indeed, when US EPA came under attack by environmental groups for favoring a dredging plan that would remove only one hundred thousand pounds of PCB, US EPA responded by adding back the mono- and dichlorinated PCB congeners that initially had been excluded when assessing potential health risks. US EPA thereby claimed that the actual amount of PCBs that would be dredged under its “revised” plan would be one hundred fifty thousand pounds, indicating that, in US EPA’s own view, the mono- and di-chlorinated congeners that were omitted from the baseline HRA would contribute 50 percent more than the one hundred thousand pounds of PCB actually included in the inventory on which the HRA was based (Michaels and Oko 2007).

We conclude that US EPA estimation of mobilization of dredge-disturbed PCBcontaminated sediment has been grossly inaccurate. Sediment resuspension has been mismeasured and evidently not limited to within the applicable EPS of 2 percent of the amount of PCB dredged at the dredgehead. Environmental performance standards that address the broader issues of sediment mobilization and spreading to new areas of the river bottom remain nonexistent, notwithstanding peer review panel findings that such EPSs are needed. We also conclude, therefore, that any extension of the dredging project as demanded recently by many in the environmental community should be predicated upon agency remediation of these deficiencies.

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Issue 2, PCB mobilization: Possible PCB loss by desorption from resuspended sediment particles

Comparison with US EPA mobilization assumptions. US EPA engineering performance standards (EPSs; US EPA 2010d, 2010e) limit dredge mobilization of PCB in sediments to < 2 percent “at the dredgehead,” which roughly is at the dredging platform. A 2010 US EPA (2010e) factsheet explicating Technical Requirements for Phase 2 of Hudson River Dredging states, for example:

The amount of PCBs allowed to travel down the river will not be allowed to exceed 2% of the amount of PCBs actually excavated from the river bottom, as measured at designated locations downstream of where the dredging is taking place.

As shown in Table 1 (in Findings), this limit routinely has been exceeded substantially, in part because measurement at downstream locations does not reflect the amount of PCB excavated at the dredgehead, and that eventually will flow down the river. Even if the 2-percent limit were not exceeded at all, however, GE estimates (Fig. 2, in Findings) shows that the break-even point, at which dredging will have reduced PCB mobilization as much as it has increased it during the dredging project, would be forty-six years. That is, no benefit can be expected until the year 2057 at the earliest, optimistically assuming no delays and, critically, no mobilization of PCB sediments other than resuspension.

Issue 3, storms: Possibly changing frequency of sediment-mobilizing high-flow events

The documented trend toward more frequent and more intense storms and resulting sediment mobilization (see Findings) can be and should be extrapolated to the future, and incorporated into Superfund remediation project assumptions, including assumptions for Hudson River PCB dredging. US EPA reported in 2011 that high river-flow caused by Tropical Storms Irene and Lee did not elevate concentrations of resuspended sediment above acceptable guidelines specified in the EPS for resuspension. However, the EPS, as already shown, dramatically underestimates PCB mobilization, and therefore constitutes a poor measure of that parameter.

When storms greatly increase river flow, uncompacted PCB sediments disturbed by dredging are scoured from the river bottom. They enter the swiftly moving water column, and are transported downstream. This downstream transport may be invisible to US EPAs EPS for resuspension because the increased river flow simultaneously dilutes the scoured sediments. This dilution reduces PCB concentrations that can be measured in river water, thereby masking the increased scouring of sediment and elevation of the rate of its downstream transport.

EXCESSIVE PCBS IN THE HUDSON RIVER © 133

ecosystems, and air. US EPA’s EPS for resuspension fails to measure these effects, and no EPS exists to measure the resulting increase in the area of newly contaminated river bottom. Future high-flow events, over years to decades, will continue to transport dredge-mobilized PCB sediments episodically downstream, where they will enter water, ecosystems, and air. Indeed, with sufficient dilution from increased river flow, virtually all dredge-disturbed PCB sediment conceivably could be driven downstream by storms and other high-flow events without contravening US EPA’s EPS for resuspension. Thus, any extension of dredging should be predicated upon adoption of EPSs that effectively quantify and limit long-term scouring of dredgedisturbed sediments and resulting increases in the area of newly contaminated river bottom.

Issue 4, endangered species: Endangered species classification of Hudson River sturgeon

In 1999, more than a decade prior to addition of the Atlantic sturgeon to the Endangered Species List, US EPA issued an addendum to its baseline ecological risk assessment for the Lower Hudson River (49). The addendum, updated in 2010, evaluated future risks posed up to the year 2018 by PCB transport from the Upper Hudson River to ecosystems in the Lower Hudson River, between the Federal Dam at Troy and the Battery in New York City. As a baseline assessment, it assumes no dredging; indeed, it assumes “the absence of remediation.” Its major conclusions (US EPA 2010c, 6) include the following:

— Fish in the Lower Hudson River are at risk from future exposure to PCBs. Fish that eat other fish (i.e., which are higher on the food chain), such as the largemouth bass and striped bass, are especially at risk. PCBs may adversely affect fish survival, growth, and reproduction;

— Fragile populations of threatened and endangered species in the Lower Hudson River, represented by the bald eagle and shortnose sturgeon, are particularly susceptible to adverse effects from future PCB exposure [emphasis added];

— The future risks to fish and wildlife are greatest in the upper reaches of the Lower Hudson River and decrease in relation to decreasing PCB concentrations down river. Based on modeled PCB concentrations, many species are expected to be at risk through 2018 (the entire forecast period).

Dredging will continue to increase transport of PCBs from the Upper Hudson River to the Lower Hudson River to a degree exceeding the no-action alternative for the full forecast period. The conclusions of the Ecological Risk Assessment Addendum, therefore, reflect consistency of US EPA’s (2010c) conclusion of record with our own: that endangered sturgeon, endangered bald eagles, and other species are at risk from continued dredging and PCB mobilization, and therefore with the general principle that environmental health is crucial for food chains and the safety of the human food supply (Hulme 2013).

134 @&)_-R.A.MICHAELS AND U. M. OKO

Our conclusion also is consistent with that of US EPA’s Hudson River PCB Dredging Peer Review Panel (2010). The panel concluded in 2010 that US EPA had failed to set an allowable sediment-loading limit, failed to gather data needed do this, and failed to develop models to predict transport of dredge-mobilized sediment and PCB bioaccumulation based upon Hudson River hydrodynamics. Thus, US EPA sampling of resuspended PCB was insufficient, because US EPA failed to sample or model the vastly larger quantity of dredge-mobilized PCB resting on the river bottom. US EPA, therefore, cannot assure the public that transport of sediment already mobilized by dredging will not increase downstream PCB loads gradually and episodically for decades, threatening ecosystems in the Lower Hudson River. It cannot assure the public and the U.S. Department of Commerce that endangered sturgeon and bald eagles can survive decades of increased PCB transport to the Lower Hudson River. Continued dredging therefore should be predicated upon development of appropriate EPSs and compliance with them, which together might enable US EPA to make such assurances credibly.

Issue 5, autism: Research into possible PCB causation of autism

Treatment of children severely impaired by autism is palliative rather than curative; that is, children with autism typically become adults with autism (Landrigan et al. 2012). Impacts on families of children with autism may be devastating physically, psychologically, and financially. Economic impacts to society likewise are enormous (Landrigan et al. 2012; Autism Speaks n.d.), and may be exacerbated since the American Psychiatric Association in 2013 changed its diagnostic mental illness definitions, combining people with severe autism and others with milder forms (such as those with Asperger's Syndrome) into a single autism spectrum disorder (ASD) category (Jabr 2012).

The issue of whether the officially completed GE Hudson River dredging project should be extended to remediate remnant PCBs must be viewed in the context of US EPAs longstanding special mandate regarding children’s health, embodied by US EPAss (2001) Children’s Health Risk Initiative. In 1997 the Office of Children’s Health Protection was instituted within US EPA. Its mission was and remains “to make children’s health protection a fundamental goal of public health and environmental protection ...[by] ensuring strong standards that protect children’s health”

Long-term remediation projects undertaken under the federal Superfund Act or its state equivalents are subject to five-year reviews. As dredging Hudson River PCBs was mandated in 2007, the first five-year review of the project was undertaken as required in 2012 (US EPA 2012). Accordingly, one of us (Michaels) informed US EPA of the emerging link between PCBs and possible causation of autism and, in a public comment, suggested that the scheduled five-year review address this issue relative to numerous river communities alongside the path of the dredging project. The five-year review (US EPA 2012), however, neither addressed this issue substantively, nor alluded to it. Indeed, the word autism was absent from the eighty-two-page report. Given the high and increasing prevalence of autism (Fig. 4; Autism Speaks

EXCESSIVE PCBS IN THE HUDSON RIVER [) 135

n.d.), and its seriousness, cost, and apparent linkage to environmental agents that may include maternal exposure to PCBs during pregnancy, extending the dredging project should be predicated upon satisfactory consideration of this emerging public health issue. The next five-year review of the dredging project is underway, for release in 2017.

Will further clamshell dredging fulfill the purpose of dredging?

Clamshell dredging has failed to meet US EPAs EPS goal of limiting short-term resuspension to <2% of the amount excavated. Consider a numerical illustration based upon the parameters quantified (at least approximately) earlier: 1,000 kg of PCB-contaminated sediment is excavated at the dredgehead. The EPS for resuspension is < 2 percent, which is < 20 kg. If 25 percent (< 250 kg) is barged, then 75 percent (< 750 kg) is mobilized, drastically contravening the 20-kg EPS. If, as reported orally by US EPA, 99 percent (750 kg x 0.99 = 742.5 kg) falls back to the river bottom near the dredgehead, then just 1 percent (7.5 kg) remains in the water column. If US EPA measured resuspension at the dredgehead, all of this resuspension would be captured in the measurement (742.5 + 7.5 = 750 kg).

A downstream measurement that is made after separation of the 1 percent remaining in the water column from the 99 percent falling back to the river bottom near the dredgehead would capture only the 7.5 kg remaining in the water column. The location of such a measurement, according to US EPA HUDTOX modeling, appears to be = 1,000 m downstream. The resuspension value obtained at this location (7.5 kg in the example) complies with the EPS for resuspension (20 kg for every 1,000 kg excavated). Measuring or modeling resuspension 1,000 m downstream of dredging, therefore, in this example drastically contravenes the EPS for resuspension by overlooking 742 kg of dredge-disturbed sediment that has fallen back to the river bottom, but is still mobile (no longer buried in the riverbed).

The above numerical example also illustrates that clamshell dredging has failed to fulfill US EPA’s main, original purpose of dredging: to reduce safely and substantially the long-term downstream transport of dredge-disturbed PCB sediments. The 742 kg of sediment that has fallen back to the river bottom in the above example still is mobile, in the sense that it can be and (if not redredged) eventually will be transported downstream via episodic high-flow events over years to decades. This redeposited mobile PCB sediment, as illustrated earlier, is invisible to the EPS for resuspension. The EPS, in turn, therefore is blind to long-term health and environmental risks potentially posed to downstream ecosystems.

Conclusion

136 @)_R.A.MICHAELS AND U.M. OKO

bad idea for the Hudson River, and has been shown incapable of fulfilling its original purpose of reducing safely and substantially the long-term downstream transport of PCBs. Our overall conclusion, therefore, is that excessive post-project PCBs in the Hudson River predominantly are attributable to sediment mobilization by clamshell dredges. We predict that proposed extension of the dredging project would prolong mobilization processes, allowing PCBs to spread widely and enter ecosystems that include people, endangered fish such as sturgeon, and endangered birds such as bald eagles.

Recommendations. We recommend that the design of any extended or future PCB dredging be improved to comply with US EPAs EPS limiting short-term resuspension to < 2 percent of PCB in sediment excavated, and adopt EPSs also limiting long-term downstream deposition of residual sediments outside of dredge zones. Increasing storm frequency and intensity must be incorporated into prediction of dredging-associated sediment transport. EPSs must limit transport to within levels shown sustainable for survival and reproduction of sturgeon, eagles, and other endangered species in the long-term, well beyond several years needed for completion of dredging. US EPA likewise must address the potential of dredging to increase the incidence of autism in affected river communities and, if necessary, adopt health protective EPSs. Finally, hydraulic dredging, originally proposed, should be considered as an alternative to conventional clamshells for extending and completing remediation of the Hudson River PCB Superfund Site.

About the authors

Robert A. Michaels is president of Schenectady-based RAM TRAC Corporation, and a toxicologist specializing in assessment and management of risks to public health potentially posed by environmental contaminants. He has served numerous corporate clients, the U.S. Congressional Office of Technology Assessment, and public interest organizations such as the Natural Resources Defense Council (NRDC). Dr. Michaels chaired the State of Maine Scientific Advisory Panel, and for twenty years chaired the Certification Review Board of the Academy of Board Certified Environmental Professionals (ABCEP); he now serves as an ABCEP trustee. Michaels has been secretary of the National Fire Protection Association (NFPA) Committee on Classification and Properties of Hazardous Chemicals, board member of the National Association of Environmental Professionals, and member of the Editorial Advisory Boards of Springer-Verlag and Cambridge University Press journals. In 2004 he was awarded ABCEP’s Kramer Medal recognizing his professional contributions. Uriel M. Oko is an independent consulting engineer in Albany, New York. He specializes in environmental remediation, cathodic protection for prevention of corrosion and material failures. At the Missouri University of Science and Technology he investigated surface behavior of mine tailings water that had been contaminated with heavy metal ions: zinc, lead, copper and mercury. He has designed remediation systems for pollution abatement of aquifers, stripping systems for the removal of MTBE (methyl-tert-butyl ether) and other volatile organic compounds from water, and cathodic protection systems for underground pipelines and storage tanks. Dr. Oko has served as an expert witness in litigation of industrial accidents. Prominent cases have involved metallurgical examination of collapsed bridge sections, fugitive chlorine gas from a water treatment plant, and collapsed scaffolds, cranes, and ladders.

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Exhibit

03. Michaels, Robert A.; and Uriel M. Oko. Lessons learned from legacy contaminants of emerging concern: Hudson River PCB dredging. Albany, New York State Bar Association (NYSBA), The New York Environmental Lawyer, 37(2):58-74, Fall 2017

page 79

Lessons Learned from Legacy Contaminants of Emerging Concern: Hudson River PCB Dredging

By Robert A. Michaels and Uriel M. Oko

ABSTRACT

Modern environmental regulation prioritizes pollution prevention, but persistent “legacy contaminants” already have been disseminated. Examples include arsenic, lead, chlorinated dioxins, DDT (dichlorodiphenyltrichloroethane), PAHs (polycyclic aromatic hydrocarbons), PCBs (polychlorinated biphenyls), PFCs, and radioactive fallout. Risks posed by some have been recognized for decades. Concern about others is emerging. PCB risks include some of longstanding concern, and others of emerging concern, including emerging evidence of possible autism causation among exposed infants and/or pregnant women. We investigated GE’s recently completed seven-year EPA-mandated clamshell dredging project for remediating PCB contamination in the Hudson River Superfund Site. Post-project PCB levels in water and fish are higher than anticipated, suggesting to some the incompleteness of dredging, and the need to extend the project to remove more PCB-bearing sediments. We found, however, that the preponderance of dredged PCB sediment was mobilized by clamshells rather than barged, and much PCB outside of dredge buckets also was mobilized. We attribute excessive PCB levels in the river to inefficiency intrinsic to clamshell dredging, rather than to incompleteness of dredging. We conclude that extension of the dredging project would prolong mobilization processes, allowing PCBs to spread more widely and pose risks in more ecosystems that include endangered fish such as sturgeon, endangered birds such as bald eagles, and people. These lessons should be applied to environmental dredging involving PCBs and other emerging contaminants. They should be embodied in remediation laws, regulations, and enforcement to assure that we leave to our descendants a more positive environmental legacy than that left to us.

INTRODUCTION —

Emerging contaminants constitute a subset of legacy contaminants, distinguished by the recency of awareness of their presence and significance in the environment (Sauvé and Desrosiers 2014). An alternative definition inappropriately would include substances not yet in commerce, as they “emerge” as candidates for commercial use. This moving-target definition suggests that emerging candidates for commercial use also are contaminants of emerging concern. They might turn out to be, but not by definition, because their commercial use should be regulated proactively, consistent with their properties and environmental dynamics.

Environmental release of contaminants predating modern regulation often was known to be detrimental. The practice exemplified Garret Hardin’s famous “tragedy of the commons” (Hardin 1968), in which private parties exploit public resources, termed “commons,” by consuming or degrading them, thereby externalizing costs, which ultimately must be borne by society. This frontier

* behavior, however, inevitably ran afoul of limiting factors

imposed by Malthusian growth of population, associated industry, and resource demand. Growth gradually diminished the commons, and diminished their capacity to absorb insult. Such unaffordable degradation constitutes another basis for “emerging concern” about legacy contaminants. In a review titled Beyond the roots of human inaction: fostering collective effort toward ecosystem conservation, Amel, et al. (2017) state that “The term ‘environmental problem’ exposes a fundamental misconception: Disruptions of Earth's ecosystems are at their root a human behavior problem.” Clearly, finding ways to reverse degradation of the commons and cost externalization is a matter of emerging

priority.

Dr. Rosert A. MicHaets is President of Schenectady-based RAM TRAC Corporation, and a toxicologist focusing on assessment and management of risks to public health potentially posed by environmental contaminants. He has served numerous corporate clients, the U.S. Congressional Office of Technology Assessment, and public interest organizations such as the Natural Resources Defense Council. Dr. Michaels chaired the State of Maine Scientific Advisory Panel, and for 20 years chaired the Certification Review Board of the Academy of Board Certified Environmental Professionals. He has been secretary of the National Fire Protection Association Committee on Classification and Properties of Hazardous Chemicals, board member of the National Association of Environmental Professionals and member of the Editorial Advisory Boards of Spring-Verlag and Cambridge University Press journals. Dr. Ure. M. Oxo is an independent consulting engineer in Albany, New York. He focuses on environmental remediation, cathodic protection for prevention of corrosion and material failures. With bachelor’s and master’s degrees in metallurgical engineering from McGill University, Dr. Oko earned his doctoral degree from the Missouri University of Science and Technology, where he investigated surface behavior of mine tailings water that had been contaminated with heavy metal ions: zinc, lead, copper and mercury. He has designed remediation systems for pollution abatement of aquifers, stripping systems for the removal of MTBE (methyl tert-butyl ether) and other volatile organic compounds from water, and cathodic protection systems for underground pipelines and storage tanks. Dr. Oko has served as an expert witness in litigation of industrial accidents. Prominent cases have involved metallurgical examination of collapsed bridge sections, fugitive chlorine gas from a water treatment plant, and collapsed scaffolds, cranes and ladders.

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As previously reported,! GE recently completed a seven-year EPA-mandated clamshell dredging project to remediate PCB contamination in the Hudson River Superfund Site. Post-project PCB levels in water and fish, however, are higher than anticipated; for example in 2016 requiring the New York State Department of Health (NYS DOH) to recommend further restriction of fish consumption (NYS DOH 2016). NYS DOH issued a “Don’t Eat” fish consumption advisory for walleye fish taken from the Hudson River downriver, between the Rip Van Winkle Bridge at Catskill and the Tappan Zee Bridge. This advisory is more stringent than the previous advisory, which recommended limiting intake of walleye to one meal per month. The current advisory was based upon new data showing elevated levels of PCBs in these fish.

In 2007 the U. S. Environmental Protection Agency (EPA) required the General Electric Company (GE) to remediate the Hudson River PCB Superfund Site via dredging. Also in 2007, we reported pro-dredging bias in the form of errors in EPA’s baseline health risk assessment (HRA) for Hudson River PCBs; indeed, all nine identified errors were made in the dredging-friendly direction rather | than randomly (Michaels and Oko 2007). Permissive | HRA findings that resulted from these errors constituted anecessary condition for EPA to conclude that dredging - could be accomplished within acceptable health and environmental risk parameters, and to require GE to employ dredging for remediatior‘ of the site. The original purpose of site remediation via clamshell dredging was to reduce safely and substantially the long-term downstream transport of PCBs.

In 2010 we evaluated dredging Phase 1 (Michaels and Oko 2010), consisting of a one-year attempt, in 2009, to demonstrate the feasibility of “clamshell” dredging as a multi-year remedy for the Hudson River PCB Superfund Site. The 2010 paper reported failure (of GE) to complete a significant fraction of the planned Phase 1 area within the allotted dredging season, and failure (of EPA) to demonstrate the feasibility of implementing Phase 2 within acceptable health risk parameters. Similar conclusions were drawn by EPA’s Peer Review Panel for Hudson River PCB dredging (Peer Review Panel 2010). Others more generally have characterized conventional “clamshells” as more typically used for navigational rather than for environmental dredging (for example, Bridges, et al. 2008; Palermo, et al. 2008):

Although conventional dredges normally used for navigation dredging (e.g., conventional clamshells or cutterheads) can be effective for environmental dredging, evolving technologies for dredge and dredgehead designs (e.g., enclosed buckets, articulated fixed-arm mechanical, swinging ladder cutterheads, and articulated ladder cutterheads) may offer better performance for environmental

dredging” (Palermo, et al. 2008, page 257; emphasis added).

Accordingly, we recommended (Michaels and Oko 2010) consideration of hydraulic dredging as originally proposed, or other alternatives to conventional “clamshells.” Indeed, EPA specification of ‘clamshell’ dredging in the Hudson River is unusual, as most PCB dredging from U.S. waters has relied upon hydraulic dredges, which were used, for example, in the New Bedford Harbor in Massachusetts, the Cumberland Bay in Plattsburgh, New York; and the Fox River in Green Bay, Wisconsin.

Notwithstanding the above, EPA required GE to initiate Phase 2 in 2011, after a one-year hiatus, in 2010, for project evaluation, culminating in our paper (Michaels and Oko 2010) and the Peer Review Panel’s adverse report (Peer Review Panel 2010). The scope of Year One of Phase 2, in 2011, included completion of the undredged Phase 1 area. As we reported (Michaels and Oko 2010), Phase 1 not only failed but, more fundamentally, it lacked the potential to succeed in demonstrating the feasibility of Phase 2, because Phase 2 posed two problems not posed in Phase 1: (1) dredging in faster-moving water, and (2) confining dredge-disturbed PCB-contaminated sediments to within isolated “hot spots,” despite river currents capable of carrying mobilized PCB liquids, dissolved molecules, colloids, and suspended particulates downstream to areas in which future dredging was not planned.

Phase 1 differed from Phase 2 in being conducted largely at one side (the east side) of Rogers Island, where sediment transport was slowed by a nearby stone dam and sediment curtain. Phase 1 also predominantly involved bank-to-bank dredging. Phase 2 involved widely separated PCB “hot spots” and faster moving open river water. Redeposition of mobilized PCB-containing sediments in the Phase 1 area was followed generally by re-dredging, thereby minimizing the impact of dredgedisturbed sediment flow and mobilization beyond the dredging zone. Thus, EPA’s authorization to conduct Phase 2 based upon Phase 1 constituted a non-sequitur.

1. Sediment mobilization: EPA accuracy in estimating PCB-contaminated sediment mobilized by

dredging, 2. PCB mobilization: possible PCB loss by desorption from resuspended sediment particles;

3. Storms: possibly changing frequency of sedimentmobilizing high flow events,

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4. Endangered species: Endangered Species classification of Hudson River sturgeon, and

5. Autism: progress of research into possible PCB causation of autism.

METHODS

Our investigation included reviewing literature, making site visits, attending meetings, and evaluating several exposure and toxicology issues. We conducted three site visits to observe and photograph dredging, each time visiting U.S. EPA’s field office in Fort Edward, interviewing EPA and GE personnel and contractors, analyzing dredging data, attending public meetings, and examining scientific and regulatory documents (for example, Harza 1992; NYS DEC 2000, 2003; PSEG NY 2001; Shavit, et al. 2003; UN EP 2003, and other sources in References). Our analysis adopts methods of health risk assessment (HRA), critical evaluation of project-related scientific information sources (for example, GE 2009, 2010a, 2010b, n.d.; US EPA 1999, 2000a, 2000b, 2001, 2006, 2010a, 2010b, 2010c, 2010d, 2010e, 2012, n.d.a, n.d.b), and objective scientific peer review. The latter are not a priori methods, and they are not described in detail here. Rather, they consist of diverse methods that are generally typical of peer review by scientists seeking to remain objective. Most essentially, these methods consist of our own disciplined, critical evaluation of the scientific merit with which numerous methods were selected for use and applied prior to dredging, during dredging Phase 1, and during Phase 2.

The scope of our assessment therefore includes our own peer review of GE and EPA methods, findings, and conclusions, such as those reported orally in public meetings, and in written public communications on GE (n.d.) and EPA websites for Hudson River dredging (US EPA n.d.a, n.d.b), and more formally in GE (2009, 2010a, 2010b, app. GE (2009, 2010a, 2010b) and EPA (1999, 2000a, 2000b, 2001, 2006, 2010a, 2010b, 2010c, 2010d, 2010e, 2012) draft and final reports published for consideration by the public, specific interested parties, and members of the Hudson River dredging project peer review panel (Peer Review Panel 2010). Members of the public and other readers of our assessment can judge for themselves whether and to what degree we succeeded in applying the methods of HRA and of peer review objectively. We hope that we have done so completely.

FINDINGS

General. Mobilization of dredge-disturbed sediment was 2100 times higher than measured by EPA's engineering performance standard (EPS) for resuspension, and no EPS exists to detect, quantify, or reduce downstream sediment redeposition. Much PCB adsorbed to dredge-disturbed sediment desorbs within minutes of mixing into river water. This fugitive molecular and colloidal PCB is transported downstream, but missed in routine resuspension monitoring. Complicating matters, the frequency and intensity of storms is increasing. Invisible to EPSs,

storms may scour fugitive PCB-contaminated sediment, and transport it downstream gradually and episodically, over years or decades. Long-term downstream transport of PCBs poses risks to endangered species, possibly including extirpation of sensitive sturgeon from the Hudson River. Finally, recent animal research links PCBs to developmental processes that, in humans, are thought to underlie autism causation, but EPA has failed to address autism risks.

Issue 1, Sediment Mobilization: EPA Accuracy in Estimating PCB-Contaminated Sediment Mobilized by Dredging

Sediment mobilization by dredge jaw closing. Sediment resuspension arising from bucket (clamshell) dredging is reported to “result from the impact, penetration, and removal [of the dredge bucket] from the bottom sediments; leakage while raising it through and out of the water column; and washing during movement through the water column” (Zappi and Hayes 1991, citing Barnard 1978). Resulting “suspended solids in the area of influence of the bucket dredge, without hopper barge overflow, can range from 20 to 1,100 mg/L” (Zappi and Hayes 1991, citing McLellan, et al. 1989). A process contributing to sediment mobilization that apparently has been neither addressed nor described previously is generation of a suction force behind closing dredge jaws.

Specifically, the sediment fraction mobilized has been calculated previously relative to a full dredge bucket, but that parameter fails to account for the mobilizing effects of closing dredge jaws on sediment that is situated outside of the bucket. Dredge bucket jaws are constructed of rigid walls of steel that are suspended beneath a rigid non-solid steel superstructure (Fig. 1). The jaws of a typical five-cubic yard (3.85-cubic meter) bucket used in the Hudson River each have an open cross-sectional area of 88 square feet (9.8 sq. M) measuring 7.1 feet (2.2 meters) in width and approximately 4.4 feet (1.3 M) in height, producing a solid cross-sectional area of >30 square feet (3 cubic meters). The superstructure adds another 6.0 feet (1.8 M) of height, producing a total of over 10 feet (3 M).

The total cross-sectional area that moves through river water during closing of each dredge jaw therefore is approximately 50 square feet (4.6 M’), most of it above river sediment grade [typical dredge jaw penetration depth is up to 1.5 feet (0.5 M), visible as the abraded area at the bottom of the bucket depicted in Fig. 1]. The angle of attack changes (becomes more vertical) as the bucket closes and, of course, the velocity of jaw movement through the water is greatest toward the bottom, which also is the solid portion of the dredge bucket.

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suction of water and sediment situated in the reducedpressure zone behind each dredge jaw. These latter two currents exert a force that drags water and sediment, causing them to follow behind moving dredge jaws as they close. All three forces create turbulence. The compressive force, especially because it drives water and sediment upward through the open top of dredge jaws, produces turbulent eddies of sediment typically extending to the river surface, readily visible and varying from gray to black, depending upon location in the river.

The inward-directed suction force exerted in the reduced-pressure zone behind the dredge jaws acts on water much as a moving vehicle acts on air. This force is manifest (for example) by race cars “drafting” close behind another car to accelerate by using the powerful suction force created by the lead car’s evacuation of air behind it. The suction force also is made visible as opaque diesel exhausts flow over the tops of moving trucks and are sucked turbulently downward in the trailing lowpressure zone. Physics demands that loose or uncompacted sediment situated outside each opposing jaw of dredge buckets likewise must be sucked off the river bottom during bucket closure. The swirling sediment then is left in the river as the dredge buckets are lifted to the surface and beyond.

Figure 1. Hudson River Dredge Showing Bucket

Michaels and Oko 2010, EPA 2010a). Sediment that is mobilized behind closing dredge jaws, however, is routinely not quantified in the “bucket files,” because such sediment is not dredged and not placed in barges. For example, consider a typical five-cubic yard dredge bucket that penetrates to a sediment depth designed to fill it to 80 percent of full capacity. Its “field capacity” would be four cubic yards (0.8 x 5 cubic yards). If only two of the four cubic yards are barged, by subtraction the inferred mobilization also is two cubic yards, or 50 percent of field

capacity.

The mobilization fraction calculated as above excludes turbulent sediment mobilization due to suction generated by each closing dredge jaw. Accordingly, the actual mobilization fraction is higher by the amount disrupted outside each dredge bucket jaw. Physics demands that the compressive force exerted to the interior of dredge bucket walls equals the suction force exerted outside. A reasonable approximation, therefore, is that uncounted sediment mobilization outside dredge buckets roughly equals the amount of sediment that is mobilized within buckets. This approximation also is conservative, inasmuch as the sediment that can be mobilized includes that situated behind each of two dredge jaws. This added mobilization factor gives rise to the possibility of the sediment mobilization fraction exceeding 100 percent of the dredge bucket field capacity. That is, dredge buckets cannot mobilize more sediment than they contain, unless (as described above) they also mobilize sediment that they do not contain.

Estimation of sediment mobilization fraction. We previously made two independent quantitative estimates of the fraction of sediment mobilized when a dredge bucket descends to the river bottom, closes, lifts its load, and transfers its load to a waiting barge (Michaels and Oko 2010). One estimate, based upon the difference between sediment volume enclosed by an open vs. a closed dredge bucket, was a mobilization fraction of approximately 80 percent. The other, based upon analysis of published “bucket files” vs. published barged-sediment data, was approximately 75 percent during Phase 1, Year 1. These values exclude consideration of the new factor described above, i.e., suction creating turbulence behind closing dredge jaws.

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withstanding our inability to quantify some parameters precisely, the factors described above, along with bucket geometry and computerized bucket data, indicate that dredge buckets dumped more material back into the river than into waiting barges. That material remains mobile via physical processes or, if taken up by biota, through ecosystem dynamics.

The two factors described above, though we cannot quantify them exactly, at the least add conservatism to our previously published estimates of 75-80 percent sediment mobilization per bucket closure. This fraction was applicable to dredge buckets, but was significantly (but likewise to an unquantified degree) reduced when considering overall sediment mobilization in Phase 1, because of bank-to-bank dredging. Such redredging in Phase 1, however, is not a feature of Phase 2 (except in its first year, 2011, which included bank-to-bank dredging of the uncompleted Phase 1 area), because Phase 2 addresses widely-spaced PCB “hotspots.” Sediments that are resuspended and carried downstream beyond a PCB hotspot may redeposit on a portion of the river bottom that will never be dredged (or redredged). Phase 2 hotspot dredging comprises the preponderance of the 40-mile (64-kM) stretch of the Upper Hudson River that is included in the dredging project, making the per-bucket mobilization fraction highly relevant for Phase 2. Given the preponderant scope of Phase 2, the per-bucket mobilization fraction is relevant in evaluating the Hudson River dredging project in its entirety.

Issue 2, PCB Mobilization: Possible PCB Loss by Desorption from Resuspended Sediment Particles

Estimation of PCB mobilization fraction. Apart from the sediment mobilization fraction addressed above is the related issue of the possibly different PCB mobilization fraction. PCBs might be mobilized by desorption from dredge-disturbed sediment as particle surfaces encounter relatively PCB-free river water. To the degree that this occurs, PCBs may be mobilized from dredge-disturbed sediment as it falls back to the river bottom or remains suspended (resuspended) in the water column. Such desorption produces free PCBs in the molecular and colloidal phase, which are transported downstream with river water. Free PCBs in river water no longer are adsorbed to clay or silt particles. Sampling of clay or silt particles in routine resuspension monitoring would not capture free PCBs in dissolved or colloidal form.

indicates that approximately 30 percent of PCB adsorbed to resuspended sediment particles desorbs and enters river water in dissolved or colloidal form within minutes of resuspension. Further, most fine particles (‘fines’) remain resuspended for hours to weeks before settling, during which they slowly release most if not all of the remaining 70 percent of adsorbed PCB (Schneider 2005). We assume that much or most of the 70 percent is captured by routine resuspension monitoring. The 30 percent that quickly enters the aqueous phase, however, would not be captured in routine particle monitoring for verification of compliance with EPA’s EPS for resuspension.

The mass of PCBs corresponding to loss of 30 percent desorbed from particles of dredge-disturbed sediment to

"the aqueous phase is missed in monitoring PCB concentra-

tion in water, due to river flow variation. We approximate it as follows. We do not know the exact size distribution of resuspended particles, but laboratory development of a dredging elutriate test (DiGiano, Miller, and Yoon 1995) revealed that turbulence mixes a wide range of particle sizes into the water column, but denser particles settle preferentially, leaving behind an elutriate (supernatant) of less dense resuspended particles, of which 90 percent were <10-um diameter. The most common size class was 4 um (micrometers). Accordingly, we similarly assume spherical particles of diameter 4 um. Although the particles are resuspended, we assume a heavier-than-water specific gravity of 1.8 which, as they are small, can be maintained in suspension by turbulence in river water. This specific gravity is somewhat lower than 2.6 previously reported for Hudson River sediments (Gruendell, et al. 1966; Michaels and Oko 2010), as we also assume here that relatively lighter resuspended particles are enriched in relatively less dense organic matter.

Our 4-um spherical particle model is only a rough guide. Fine particles resuspended after dredge disturbance actually are non-spherical, and some are more porous than others, whereas we assume hard spheres. Both properties increase surface area. For example, clay, an important constituent of silt, is both porous and nonspherical, with particle surface areas of 200-600 m2/g. Our hard-sphere model therefore is conservative, because porous non-spherical particles have more surface area, _ can adsorb more PCB, and thus desorb more PCB to river water.

The high surface area of small sediment particles such as clay disproportionately carries resuspended PCB (Anchor Environmental 2003, DiGiano, Miller, and Yoon 1995, Michaels and Oko 2010). We assume that each resuspended hard spherical particle is coated initially with a monolayer of PCB molecules. We also assume an average PCB molecular weight of 240 grams/mole. Table 1 (below) shows the following calculated parameter values:

1. The mass of a monolayer of PCB on a 4-um spherical particle is 2.00 x 107 g;

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. The mass of a particle of 4-um diameter and specific gravity 1.8 is 6.03 x 107 g;

. An 80-percent full 5-cu yd dredge bucket can con- =

tain 9.13 x 10'6 4-um particles;

in aqueous phase is 810 kg.

Table 1. PCB Desorption from Resuspended Sediment in 10-Acre Phase 1 Year One Hudson River Dredging Area

Mass of PCB rapidly desorbed from a resuspended spherical sediment p:

article of diameter 4 microns

radius of 4-um diameter spherical particle 2 um

surface area of spherical particle of 4-um diameter: 4x1” 50.3 sq. um

area occupied by one molecule of (decachlorinated) PCB 300 sq Angstroms

area occupied by one molecule of (decachlorinated) PCB 3.00E-06 [sq um

PCB molecules in monolayer on one 4-um diameter particle 1.68E+07__|PCB molecules

molecular weight (MW) of the PCB molecule 240 g/mole

number of PCB molecules per mole (Avogadro's number) 6.02E+23 _|PCB molecules

moles of PCB monolayer adsorbed to 4-um diameter particle 2.78.E-17__|moles

mass of PCB molecules on one 4-um diameter particle 6.68.E-15 |g

fraction of PCB rapidly desorbed and entering river in aqueous phase 0.3 i

mass of PCB rapidly desorbed to water, per 4-um diameter particle 2.00.E-15__|g/0.04-um particle Mass of a resuspended spherical sediment particle of diameter 4 microns

volume of spherical particle of 4-um diameter: 4/3 x13 3.35.E+01 [cu um

conversion, cu um to liter (= 1000 cu cm) 1.00.E-15 _|cu um/liter

volume of spherical particle of 4-um diameter: 4/3 pr3 3.35.E-14 _|liters

|specific gravity of 4-um diameter spherical particle 18 g/ml = kg/liter

conversion, g/ml to g/cu M 1.00.E-06 __|(g/cu M)/(g/ml)

|specific gravity of 4-um diameter spherical particle 1.80.E+06__|g/cuM

mass of spherical particle of 4-um diameter 6.03.E-14 _|kg/0.04-um particle

mass of spherical particle of 4-um diameter 6.03.E-11 _|g/0.04-um particle

No. of spherical sediment particles of diameter 4 microns fitting into a 5-cubic yard dredge bucket

converion, cubic yards to cubic meters 7.65.E-01__|cuM/cu yd volume of 5-cu yd dredge bucket 3.82.E+00__|cuM

field capacity if filled to 80 percent of full capacity 3.06.E+00__|cuM

volume of spherical sediment particle of diameter 4 um 3.35.E+01_|cuum conversion, cu um to cu M 1.00.E-18 [cu M/cu um volume of spherical sediment particle of diameter 4 um 3.35.E-17__|cuM

no. of 4-um spherical sediment particles per 5S-cu yd bucket 9.13.E+16 __|particles/bucket

Allowable resuspension in 10-acre Phase 1, Year 1 dredging area, under EPA's 2-percent EPS

mass of sediment particles per 5-cu yd dredge bucket 5.50.E+03__|kg_

EPA engineering performance standard (EPS) for resuspension a percent

allowable resuspended particle mass, in accordance with EPS 110.10 kg/S-cu yd bucket bucket closures in 10-acre area dredged in Phase 1, Year | 221,521 bucket closures/10 acres allowable resuspended particle mass, in 10-acre Phase 1, Year 1 area 2.44.E+07__|kg/10 acres

Mass of PCB rapidly desorbed to water from resuspended particles in 10-acre Phase 1, Year 1 area

4-um diameter spherical particles per gram 1.66.E+10 |particles/gram 4-um particles resuspended in 10 acre Phase 1, Year | area 4.04.E+20 [particles

mass of PCB adsorbed as monolayer on resuspended particles 2.70.E+03__|kg of PCB adsorbed mass of PCB rapidly desorbed from resuspended particles 8.10.E+02_ [kg of PCB desorbed

4. EPA's 2-percent EPS allows resuspension of 2.44 x 10” kg in the 10-acre Phase 1, Year 1 dredging area;

5. The estimated mass of PCB desorbed to the river

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GE estimates show that the break-even point, at which dredging will have reduced PCB mobilization as much as it has increased it during the dredging project, would be 20 years, assuming compliance with EPA's two-percent EPS for Resuspension. This would bring the break-even year to 2032 (Fig. 2). Under GE’s highest mobilization assumption, five percent of sediment is released back to the river “at the dredgehead,” in which case dredging will require 46 years to match the effectiveness of the no-action remediation alternative. That is, no benefit can be expected until the year 2057 at the earliest, optimistically assuming no delays and, critically (see Discussion), no mobilization of PCB sediments other than “resuspension.”

Fig. 2. At Waterford: GE Projected Years Needed To Match No-Dredging, Assuming Zero Dredge Mobilization of PCB Other Than 'Resuspension’ aa ow) at Grengenend s~ * [Marto match no-dredging i. lasy. =| ay - om Bafa . i fy = = ; e = i (-F | (Sa ail = —— ° ie ¥. = EP EE PEE EEELEPEEI SL LILI PL IEL

Issue 3, Storms: Possibly Changing Frequency of Sediment-Mobilizing High Flow Events

After the first season of dredging, GE (2010b) reported that sediment samples outside the dredged area “show that dredging caused wide-spread redistribution of PCB-containing sediments on the surface of the river bottom.” High-flow events already have driven some of this dredge-mobilized sediment downstream (for example, Islam, et al. 2012; Michaels and Oko 2010). Indeed, recent years have evinced a trend toward increasing frequency and intensity of storms (Matonse and Frei 2012), including extreme events such as Hurricane Katrina in 2005, Irene in 2011, and Sandy in 2012, all attaining extraordinary energy, largely from warmer ocean water in their path (for example, Trenberth 2007).

..-a marked increase in the frequency of extreme hydrologic events during the last one to two decades. This increasing trend is more evident during the late summer and early fall, the season of the most extreme precipitation events.

This trend, therefore, can be extrapolated to the future, and incorporated into Superfund remediation project assumptions, including assumptions for Hudson River PCB dredging.

Tropical Storms Irene and Lee caused 100-year and 500-year flooding, in which the Mohawk River carved new channels up to 45 feet deep. The storms exerted comparable impacts on the Hudson River. For example, the storms delivered an extraordinary amount of fresh water to the Hudson River watershed, along with a US Geological Survey (US GS) estimate of nearly three million tons (2.7 x 10° kg) of sediment (Wall and Hoffman 2012).

Potential effects of swift river flow include scouring of PCB-laden sediment exposed by dredging to downstream areas, washing away of plantings designed to stabilize the river bottom and reestablish ecosystems, disruption of caps placed over residual PCB-containing sediments, flooding, and depositing PCB sediment on the shore as “flood mud.” Islam, et al. (2012), investigating the impact of Tropical Storm Irene-associated precipitation on the Hudson River and estuary ecosystem, reported the following:

Continuous monitoring data at the PCB superfund site at Fort Edward, NY ... showed significant and coincident increases in sediment flux (22 metric ton/ hr to 2400 metric ton/hr) and stream flow (85 m3/s to 480 m3/s) following Irene. In addition, in-situ particle size measurements suggest that significant amounts of small particles (<70 ym diameter) were transported during the flood event...

... Moreover, the contribution of these extreme storm effects to the overall loading is comparable to that of long-term sediment transport under ordinary conditions. This suggests that effects of episodic events should be considered as part of ecosystem management during activities such as navigational channel dredging, remediation projects, and long-term water usage and discharge control.

Issue 4, Endangered species: Endangered Species Classification of Hudson River Sturgeon

. EPA reported that PCB concentrations in fish tissue in the Upper Hudson River increased five-fold after the

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first year of dredging (EPA 2010a, e; 2012, n.d.a, n.d.b.). EPA reported more recently that PCB concentrations in fish tissue in the Upper Hudson River sampling area have returned to normal, presumably due to a combination of contaminated sediment removal and downstream transport of residuals (EPA 2010e; 2012, n.d.a, n.d.b.). Indeed, EPA’s Hudson Field Office director David King acknowledged orally at a conference at Marist College (16 January 2013) that 20-30 years might be required for PCB levels in fish tissue to decline again to levels safe for human consumption. Resuspended PCB transported downstream

is assumed (by us and by EPA) eventually to reach the Lower Hudson River, which is the principal habitat of two species of sturgeon (Shepherd 2006, U.S. DOC 2012). Indeed, such transport is more than theoretical, but has been documented empirically. Hudson River Natural Resource Trustees reported (NYS, U.S. DOC, and U.S. DOI 2013) that PCB transport (mostly prior to dredging) already has resulted in PCB contamination of the Lower Hudson River:

The Hudson River ahah. aarp Trustees are conducting a natural resource damage assessment (NRDA) to investigate natural resource injuries that may have occurred due to the release of polychlorinated biphenyls (PCBs) from General Electric (GE) facilities at Hudson Falls and Fort Edward, NY. This report summarizes available information on PCB contamination in the Hudson River ecosystem, including historic information, but focusing particularly on data collected and analyzed between 2002 and 2008 as part of ongoing NRDA activities. The Hudson River, for greater than 200 miles below Hudson Falls, NY, is extensively contaminated with PCBs. Surface waters, sediments, floodplain soils, fish, birds, wildlife, and other biota are all contaminated with PCBs” [NYS, US DOC, and US DOI 2013, page 1; emphasis added].

The shortnose sturgeon (Acipenser brevirostrunt) was listed as endangered in 1967, though (in 2006; Shepherd 2006) it appeared to be recovering inasmuch as it has not been a target of fishing since 1967. The U.S. Department of Commerce on February 6, 2012 added the Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) to the Endangered Species List (U.S. DOC 2012). The Commerce Department must protect sturgeon habitat—principally the Hudson River (Shepherd 2006)—as required by the Federal Endangered Species Act. Loss of habitat is a big part of the problem of loss of sturgeon, inasmuch as the principal alternative loss factor, fishing for either species of sturgeon, has been prohibited for well over a decade, since a moratorium on harvesting wild Atlantic sturgeon was established in 1998, after decades of overfishing. Com-

mercial landings of Atlantic sturgeon crashed before the moratorium was imposed (Fig. 3; Shepherd 2006). The Lower Hudson River, below the Federal Dam at Troy, evidently will be impacted by PCBs for years or decades as contaminated dredge-mobilized sediments are scoured and transported downstream from an increasing area of river bottom in the Upper Hudson River, at Fort Edward and to the south.

Early life stages of sturgeon including larvae and eggs... “caviar”... are particularly susceptible to PCB contamination (EPA 2010c). According to EPA (previous to the official Endangered Species classification of the Atlantic sturgeon): “Fragile populations of threatened and endangered species in the Lower Hudson River, represented by the bald eagle and shortnose sturgeon, are particularly susceptible to adverse effects from future PCB exposure.”

Figure 3. Total Commercial Landings of Atlantic Sturgeon in the U.S. Historically*

14y,

Metric Tons

it)

1990 1930 1940 19501980” 1970 198-1900 2000 Year

* Source: Shepherd, G. Status of Fishery Resources off the Northeastern US

Atlantic and Shortnose sturgeons: Atlantic (Acipenser oxyrhynchus), Shortnose

{Acipenser brevirostrum, National Oceanic and Atmospheric Administration

(NOAA), Northeast Fisheries Science Center (NEFSC), Resource Evaluation and

Assessment Division, www.nefsc.noaa.gov/sos/spsyn/af/sturgeon, 3 pages, revised December 2006.

By “future PCB exposure” EPA (EPA 2010c) meant future exposure if dredging does not occur... but dredging did occur. PCB levels in Lower Hudson River water presumably will vary over space and time as they increase gradually to an undetermined maximum over a period of years or decades, during which annual sturgeon reproductive cycles will be stressed. The degree of stress, and ability of already stressed sturgeon populations to withstand it, both remain unknown.

Modeling of the dynamics of three million tons of sediment loading into the Hudson River following Tropical Storms Irene and Lee, undertaken by Ralston, Geyer, and Warner (2012), revealed the following:

The simulated sediment transport showed surprisingly little sediment export—most of the sediment delivered by the storms was

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trapped in the tidal river north of West Point according to the model.

Issue 5, Autism: Research Into Possible PCB Causation of Autism

PCBs are known neurotoxicants (ATSDR 2000). Moreover, PCBs have been implicated in causation of Parkinson‘s disease (Goldman, et al. 2016), ADHD (Keil and Lein 2016), and autism (Keil and Lein 2016, Landrigan, et al., 2012; Wayman, et al. 2012a, 2012b). PCBs are known developmental neurotoxicants at environmental levels of exposure. Based upon prospective epidemiology studies, maternal exposure to PCBs during pregnancy has been linked to dyslexia, attention deficit hyperactivity disorder (ADHD), and loss of cognition (reduced IQ; Winneke 2011). More recent (animal) studies now link PCBs to DNA methylation (Keil and Lein 2016) and to specific developmental processes that, in humans, are thought to underlie causation of autism (Landrigan, et al., 2012; Wayman, et al. 2012a, 2012b), most notably the following:

1. stimulation of calcium signaling in the brain that alters nerve cell dendrite branching,

2. increased dendrite growth and branching, and

3. alteration of synapse formation in developing brains (in animal bioassays).

The prevalence of autism has been increasing dramatically in recent decades (Fig. 4; Autism Speaks, n.d.), and today affects 1.13 percent of children (one of 88; Autism Speaks, n.d.; Landrigan, et al., 2012; US DOH 2012) and nearly one of 54 boys (Autism Speaks, n.d.). A substantial portion of the increase in autism prevalence evidently is attributable to environmental factors. Boys are nearly five times more likely than girls to have autism (Autism

Figure 4. Autism Prevalance Trend

Autism Prevalence

On The Rise* Tite hat Baan 4 200% coos prevent

vet STUDY PUBLICATION DATES

Speaks, n.d.), suggesting sex-linked inheritance of susceptibility factors, as boys have just a single (maternal) X chromosome which, if damaged, lacks potential compensation from genes in a counterpart (paternal) X chromosome as is the case in girls, who inherit an X chromosome from each parent.

DISCUSSION

Issue 1, Sediment mobilization: EPA Accuracy in Estimating PCB-Contaminated Sediment Mobilized by Dredging

EPA’s Engineering Performance Standard (EPS) pointedly refers to “resuspension,” not “mobilization.” These terms might seem intuitively synonymous but, in EPA parlance, “resuspension” denotes just a minuscule fraction of dredge-mobilization of sediment. A significant “sediment mobilization discrepancy” therefore exists between sediment that is mobilized by dredging versus the much smaller amount of sediment that is measured and reported by GE, and used to document compliance with the EPA “resuspension” EPS. The discrepancy arises from the fact that the preponderance of dredge-resuspended sediment falls back to the riverbed, and remains on the - river bottom, still mobile, but unrecorded by GE or EPA because its “resuspension” typically is episodic over years to decades and, in the main, has not yet occurred.

EPA EPSs limit dredge mobilization of sediments to a maximum of two percent “at the dredgehead” (US EPA 2010d, 2010e, n.d.a). Results of EPA modeling using HUDTOX, however, clearly indicated that the twopercent EPS, even for resuspension alone, could not be attained at the dredgehead; indeed, it was redefined upward simply by changing (at least doubling) the estimated mass of PCBs to be dredged (and also the allowable resuspension fraction), and therefore the amount (mass) of allowable PCB “resuspension”:

[The Record of Decision] originally estimated the PCB mass to be removed as approximately 70,000 kg, and the total project cumulative load standard was set at just below 1 percent of this total,

or 650 kg. Based on the Phase 1 experience and additional sampling results, the estimated PCB mass for the entire project has been revised to the range 140,000 to 200,000 kg (EPA 2010d, page 4-2).

The sediment mobilization problem also was highlighted by EPA’s Hudson River Dredging Peer Review Panel (Peer Review Panel 2010). The Panel’s initial draft report (draft of 32), published to elicit comments, made an interesting error, which was followed by a more interesting response by EPA. The Panel’s Comment No. 6 stated the following:

[EPA’s] incomplete analysis done for the 2004 EPS does not consider near-field

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and far-field PCB deposition rates on the sediment bed surface.

Thus, according to the Peer Review Panel, EPA failed to consider sediment mobilization at the dredgehead (‘near field’), where dredged sediments are mobilized. EPA’s response to Peer Review Panel Comment No. 6 is highly informative regarding this issue, and exemplifies EPA’s worst practice in handling data that might interfere with Agency plans: ;

EPA did simulate near field suspended matter transport and settling in its nearfield modeling analysis. The HUDTOX model runs did not reflect the near-field settled solids but did incorporate an estimate of dredging-related suspended solids transport 1000 meters downstream of the dredge. This analysis was the basis for the EPA forecasts of dredging-related resuspension [EPA 2010b, emphasis added].

Thus, EPA apparently could not meet the two-percent (originally one-percent) EPS limit at the dredgehead, so it declined to apply its HUDTOX modeling results at the dredgehead to forecast dredging-related resuspension quantitatively. Instead, EPA applied results obtained from HUDTOX at a cleaner place in the river, 1,000 meters downstream of dredging. Inasmuch as nearly all dredgedisturbed sediment (orally reported by EPA at roughly 99 percent) falls back to the river bottom near the dredgehead, the use of HUDTOX results from 1,000 meters downstream ignores roughly 99 percent of resuspension occurring at the dredgehead. This is at best misleading and, indeed, the expert Peer Review Panel was misled as indicated by its incorrect criticism (quoted above) that EPA had failed to model resuspension at the dredgehead (in the “near field”). The Agency did do the modeling, but (as EPA stated) declined to use the results.

As explained, sediment mobilization via dredging includes resuspension (at the dredgehead or wherever estimated) as well as the preponderance of dredgedisturbed sediment that falls back to the riverbed and is not barged (which we approximated conservatively at 75-80 percent of the amount initially excavated). This sediment drops back to the river bottom, still mobile, but it is excluded from EPA’s resuspension parameter. EPA’s statement quoted above therefore shows that the agency justified dredging by ignoring gradual erosion from the river bottom of dredge-mobilized PCB-bearing sediments, which reasonably would be expected to occur over a period of years to decades. The agency thereby also ignored inevitable, though gradual, entry of PCBs from these sediments into downstream water, ecosystems, and air. Thus, in 50 years EPA conceivably might find the river to be in much the same condition from GE dredging up sediments today as it was found to be 50 years ago from GE disposal of PCBs into the river.

The modeling and data handling issues raised above presumably would have come under scrutiny by EPA’s Hudson River PCB Dredging Peer Review Panel, but EPA explicitly prohibited the Panel from opining whether dredging should continue, or whether Phase 2, if undertaken, could meet project health goals (Peer Review Panel 2010). Nonetheless, the Peer Review Panel rejected EPA’s response, quoted above, concluding in its final report:

Phase 1 showed that the 2004 EPS [Engineering Performance Standards] for Resuspension, Residuals, and Productivity were not met individually or simultaneously during Phase 1 and cannot be met under Phase 2 without substantive changes. EPA and GE proposed changes to the EPS, but the Panel finds that the new proposed standards from either party would not contribute to the successful execution of Phase 2 [Peer Review Panel 2010, page 84].

The sediment mobilization discrepancy discussed above represents more than merely a difference between a predicted vs. a measured parameter value. It represents a fundamental inconsistency in EPA’s past justification of the need to dredge versus EPA’s current characterization of the performance of the dredging project. The need for dredging was justified by the observed, persistent mobility of PCB sediments requiring, according to EPA, their removal via dredging. In contrast, in the new context of actual dredging, EPA dramatically has altered its concept of mobility. Mobility in the dredging project is newly quantified by the minuscule fraction of mobilized (“resuspended”) PCBs that is detected at significant distance downstream. Thus, EPA has ignored nearly all sediment and PCB mobilization in evaluating compliance with the Engineering Performance Standard for resuspension. In ignoring mobility of PCB-containing dredge-mobilized sediments for gauging compliance with the resuspension EPS, EPA has ignored a much larger degree of PCB sediment mobility than that which constituted EPA’s most essential basis for requiring, in 2007, remediation of the Hudson River PCB Superfund Site via dredging.

Failure of EPA to use HUDTOX modeling results at the dredgehead is not the only example of misleading use of modeling or monitoring data by EPA, and should be viewed in this broader context. One example will suffice. In seeking to justify dredging, EPA had prepared a baseline health risk assessment (HRA; EPA 1999, 2000a, 2000b) that excluded all mono- and di-chlorinated PCB congeners based upon a misleading premise, specifically,

" that these congeners do not bioaccumulate in fish tissue,

which contributes to human exposure to PCBs (Michaels and Oko 2007). The mono- and di-chlorinated congeners, even if they bioconcentrate less dramatically than the higher chlorinated congeners, still are present in fish tissue. They should have been present in the HRA.

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In the 1960s, Rachel Carson’s Silent Spring (Carson 1962) famously raised awareness of environmental risks posed by DDT, which is a nearly identical twin of PCBs (Michaels and Oko 2010). Both DDT and PCBs contribute to human health risk by entering air, water, and ecosystems that include food chains terminating in consumption of fish and birds by people. Higher-chlorinated PCBs degrade via dechlorination, resulting in build-up of the mono- and di-chlorinated congeners. Their omission from EPA’s HRA, therefore, contributed significantly to obtaining its dredging-permissive results. Indeed, when EPA came under attack by environmental groups for favoring a dredging plan that would remove only 100,000 pounds of PCBs, EPA responded by adding back the mono- and di-chlorinated PCB congeners that initially had been excluded when assessing potential health risks. EPA thereby claimed that the actual amount of PCBs that would be dredged under its “revised” plan would be 150,000 pounds, indicating that, in EPA’s own view, the monoand di-chlorinated congeners that were omitted from the baseline HRA would contribute 50 percent more than the 100,000 pounds of PCBs actually included in the inventory on which the HRA was based (Michaels and Oko 2007).

We conclude that EPA estimation of mobilization of dredge-disturbed PCB-contaminated sediment has been grossly inaccurate, Sediment resuspension has been mismeasured and evidently not limited to within the applicable EPS of two percent of the amount of PCB dredged at the dredgehead. Environmental Performance Standards that address the broader issues of sediment mobilization and spreading to new areas of the river bottom remain non-existent, notwithstanding Peer Review Panel findings that such EPSs are needed. We also conclude, therefore, that any extension of the dredging project as demanded recently by many in the environmental community should be predicated upon Agency remediation of these deficiencies.

Issue 2, PCB Mobilization: Possible PCB Loss by Desorption from Resuspended Sediment Particles

Comparison with EPA mobilization assumptions. EPA Engineering Performance Standards (EPSs; EPA 2010d, 2010e) limit dredge mobilization of PCB in sediments to <2 percent “at the dredgehead,” which roughly is at the dredging platform. A 2010 EPA “Fact sheet” explicating Technical Requirements for Phase 2 of Hudson River Dredging (EPA 2010e) states, for example:

As shown in Table 1 (in Findings), this limit routinely has been exceeded substantially, in part because measure-

ment at downstream locations does not reflect the amount of PCBs excavated at the dredgehead, and that eventually will flow down the river. Even if the 2 percent limit were not exceeded at all, however, GE estimates (Fig. 2, in Findings) shows that the break-even point, at which dredging will have reduced PCB mobilization as much as it has increased it during the dredging project, would be 46 years. That is, no benefit can be expected until the year 2057 at the earliest, optimistically assuming no delays and, critically, no mobilization of PCB sediments other than “resuspension.”

Issue 3, Storms: Possibly Changing Frequency of Sediment-Mobilizing High-Flow Events

The documented trend toward more frequent and more intense storms and resulting sediment mobilization (see Findings) can be and should be extrapolated to the future, and incorporated into Superfund remediation project assumptions, including assumptions for Hudson River PCB dredging. EPA reported in 2011 that high riverflow caused by Tropical Storms Irene and Lee did not elevate concentrations of resuspended sediment above acceptable guidelines specified in the EPS for resuspension. However, the EPS, as already shown, dramatically underestimates PCB mobilization, and therefore constitutes a poor measure of that parameter.

When storms greatly increase river flow, uncompacted PCB sediments disturbed by dredging are scoured from the river bottom. They enter the swiftly moving water column and are transported downstream. This downstream transport may be invisible to EPA’s EPS for resuspension because the increased riverflow simultaneously dilutes the scoured sediments. This dilution reduces PCB concentrations that can be measured in river water, thereby masking the increased scouring of sediment and elevation of the rate of its downstream transport.

Swift river flow events increase downstream transport of PCB sediments to a greater degree if dredging is not suspended during their occurrence. Such episodes presumably would increase the pace of downstream contamination of water, ecosystems, and air. EPA’s EPS for resuspension fails to measure these effects, and no EPS exists to measure the resulting increase in the area of newly contaminated river bottom. Future high-flow events, over years to decades, will continue to transport dredge-mobilized PCB sediments episodically downstream, where they will enter water, ecosystems, and air. Indeed, with sufficient dilution from increased river flow, virtually all dredge-disturbed PCB sediment conceivably could be driven downstream by storms and other high-flow events without contravening EPA’s EPS for resuspension. Thus, any extension of dredging should be predicated upon adoption of EPSs that effectively quantify and limit long-term scouring of dredge-disturbed sediments and resulting increases in the area of newly contaminated river bottom.

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Issue 4, Endangered species: Endangered Species Classification of Hudson River Sturgeon

In 1999, more than a decade prior to addition of the Atlantic sturgeon to the Endangered Species List, EPA issued an addendum to its baseline ecological risk assessment for the Lower Hudson River (EPA 2010c). The Addendum, updated in 2010, evaluated future risks posed up to the year 2018 by PCB transport from the Upper Hudson River to ecosystems in the Lower Hudson River, between the Federal Dam at Troy and the Battery in New York City. As a baseline assessment, it assumes no dredging; indeed it assumes “the absence of remediation.” Its major conclusions (EPA 2010c, page 6) include the following:

¢ Fish in the Lower Hudson River are at risk from future exposure to PCBs. Fish that eat other fish (i.e., which are higher on the food chain), such as the largemouth bass and striped bass, are especially at risk. PCBs may adversely affect fish survival, growth, and reproduction;

e Fragile populations of threatened and endangered species in the Lower Hudson River, represented by the bald eagle and shortnose sturgeon, are particularly susceptible to adverse effects from future PCB exposure [emphasis added];

¢ The future risks to fish and wildlife are greatest in the upper reaches of the Lower Hudson River and decrease in relation to decreasing PCB concentrations down river. Based on modeled PCB concentrations, many species are expected to be at risk through 2018 (the entire forecast period).

Dredging will continue to increase transport of PCBs from the Upper Hudson River to the Lower Hudson River to a degree exceeding the no-action alternative for the full forecast period. The conclusions of the Ecological Risk Assessment Addendum, therefore, reflect consistency of EPA’s conclusion of record (EPA 2010c) with our own: that endangered sturgeon, bald eagles, and other species are at risk from continued dredging and PCB mobilization, and therefore with the general principle that environmental health is crucial for food chains and the safety of the human food supply (Hulme 2013).

Our conclusion also is consistent with that of EPA’s Hudson River PCB Dredging Peer Review Panel (Peer Review Panel 2010). The Panel concluded in 2010 that EPA had failed to set an allowable sediment loading limit, failed to gather data needed do this, and failed to develop models to predict transport of dredge-mobilized sediment and PCB bioaccumulation based upon Hudson River hydrodynamics. Thus, EPA sampling of resuspended PCB was insufficient, because EPA failed to sample or model the vastly larger quantity of dredge-mobilized PCB resting on the river bottom. EPA, therefore, cannot assure the public that transport of sediment already mobilized by dredging will not increase downstream PCB loads gradually and episodically for decades, threatening ecosystems

in the Lower Hudson River. It cannot assure the public and the US Department of Commerce that endangered sturgeon and bald eagles can survive decades of increased PCB transport to the Lower Hudson River. Continued dredging, therefore, should be predicated upon development of appropriate EPSs and compliance with

‘them, which together might enable EPA to make such as-

surances credibly.

Issue 5, Autism: Research Into Possible PCB Causation of Autism

Treatment of children severely impaired by autism is palliative rather than curative; that is, children with autism typically become adults with autism (Landrigan, et al. 2012). Impacts on families of children with autism may be devastating physically, psychologically, and financially. Economic impacts to society likewise are enormous (Autism Speaks n.d.; Landrigan, et al. 2012), and may be exacerbated since the American Psychiatric Association in 2013 changed its diagnostic mental illness definitions, combining people with severe autism and others with milder forms (such as those with Asperger’s Syndrome) into a single “autism spectrum disorder” (ASD) category (abr 2012).

The issue of whether the officially completed GE Hudson River dredging project should be extended to remediate remnant PCBs must be viewed in the context of EPA's longstanding special mandate regarding children’s health, embodied by EPA’s Children’s Health Risk Initiative (EPA 2001). In 1997 the Office of Children’s Health Protection was instituted within EPA. Its mission was and remains “to make children’s health protection a fundamental goal of public health and environmental protection... [by] ensuring strong standards that protect children’s health...”

Long-term remediation projects undertaken under the Federal Superfund Act or its state equivalents are subject to five-year reviews. As dredging Hudson River PCBs was mandated in 2007, the first five-year review of the project was undertaken as required in 2012 (EPA 2012). Accordingly, one of us (Michaels) informed EPA of the emerging link between PCBs and possible causation of autism and, in a public comment, suggested that the scheduled five-year review address this issue relative to numerous river communities alongside the path of the dredging project. The five-year review (EPA 2012), however, neither addressed this issue substantively, nor alluded to it. Indeed, the word “autism” was absent from the 82-page report. Given the high and increasing prevalence of autism (Fig. 4; Autism Speaks n.d.), and its seriousness, cost, and apparent linkage to environmental agents that may include maternal exposure to PCBs during pregnancy, extending the dredging project should be predicated upon satisfactory consideration of this emerging public health issue.

The next five-year review of the dredging project is underway, scheduled for release in 2017. On 31 May 2017,

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EPA released the proposed Second Five-Year Review for public comment. As with the first review, the second neither addresses the autism issue nor alludes to it. Indeed, the word “autism” as before is absent from the 81-page report, notwithstanding several reports in the literature that are cited in this paper and, more importantly, were cited in Michaels and Oko (2017), predating by over one month EPA’s proposed Second Five-Year Review. Indeed, all three of our papers (Michaels and Oko 2007, Michaels and Oko 2010, Michaels and Oko 2017), which are highly critical of EPA’s project methods and effectiveness, are excluded from citation and consideration by the proposed Second Five-Year Review, just as in 2012 EPA excluded from its first five-year review our two then-existing peerreviewed published papers.

Will Further Clamshell Dredging Fulfill the Purpose of Dredging?

Clamshell dredging has failed to meet EPA’s EPS goal of limiting short-term resuspension to <2% of the amount excavated. Consider a numerical illustration based upon the parameters quantified (at least approximately) earlier: 1000 Kg of PCB-contaminated sediment is excavated at the dredgehead. The EPS for resuspension is <2%, which is <20 Kg. If 25% (<250 kg) is barged, then 75% (<750 kg) is mobilized, drastically contravening the 20-Kg EPS. If, as reported orally by EPA, 99% (750 kg x 0.99 = 742.5 kg) falls back to the river bottom near the dredgehead, then just 1% (7.5 kg) remains in the water column. If EPA measured resuspension at the dredgehead, all of this resuspension would be captured in the measurement (742.5 + 7.5 = 750 kg).

A downstream measurement that is made after separation of the one percent remaining in the water column from the 99 percent falling back to the river bottom near the dredgehead would capture only the 7.5 Kg remaining in the water column. The location of such a measurement, according to EPA HUDTOX modeling, appears to be 21,000 M downstream. The resuspension value obtained at this location (7.5 kg in the example) complies with the EPS for resuspension (20 kg for every 1,000 kg excavated). Measuring or modeling resuspension 1,000 M downstream of dredging, therefore, in this example drastically contravenes the EPS for resuspension by overlooking 742 kg of dredge-disturbed sediment that has fallen back to the river bottom, but is still mobile (no longer buried in the riverbed).

The above numerical example also illustrates that clamshell dredging has failed to fulfill EPA’s main, original purpose of dredging: to reduce safely and substantially the long-term downstream transport of dredge-disturbed PCB sediments. The 742 kg of sediment that has fallen back to the river bottom in the above example still is mobile, in the sense that it can be and (if not re-dredged) eventually will be transported downstream via episodic high-flow events over years to decades. This redeposited mobile PCB sediment, as illustrated earlier, is invisible to the

EPS for resuspension. The EPS, in turn, therefore is blind to long-term health and environmental risks potentially posed to downstream ecosystems.

RECOMMENDATIONS AND CONCLUSIONS

Recommendations

We recommend that the design of any extended or future PCB dredging be improved to comply with EPA's EPS limiting short-term resuspension to <2% of PCBs in sediment excavated, and adopt EP$s also limiting longterm downstream deposition of residual sediments outside of dredge zones. Increasing storm frequency and intensity must be incorporated into prediction of dredgingassociated sediment transport. EPSs must limit transport to within levels shown sustainable for survival and reproduction of sturgeon, eagles, and other endangered species in the long term, well beyond several years needed for completion of dredging. EPA likewise must address the potential of dredging to increase the incidence of autism in affected river communities and, if necessary, adopt health protective EPSs. Finally, hydraulic dredging, originally proposed, should be considered as an alternative to conventional “clamshells” for extending and completing remediation of the Hudson River PCB Superfund Site.

Conclusions

Emerging contaminants constitute a subset of legacy contaminants, distinguished by the recency of awareness of their presence and degree of significance in the environment. Their adverse effects should be viewed retrospectively as remediation challenges, and prospectively as lessons that teach and motivate us to avert similar indiscretions in the future. PCB risks include some of longstanding concern, and others of emerging concern, most notably including emerging evidence of possible autism causation among exposed infants and/or pregnant women.

We investigated GE’s recently completed seven-year EPA-mandated clamshell dredging project for remediating PCB contamination in the Hudson River Superfund

" Site. Post-project PCB levels in water and fish are higher

than anticipated, suggesting to some the incompleteness of dredging, and the need to extend the project to remove more PCB-bearing sediments. We found, however, that the preponderance of dredged PCB sediment was mobilized by clamshells rather than barged, and much PCB outside of dredge buckets also was mobilized. We attribute excessive PCB levels in the river to inefficiency intrinsic to clamshell dredging, rather than ta incompleteness of dredging. We conclude that extension of the dredging project would prolong mobilization processes, allowing PCBs to spread more widely and pose risks

in more ecosystems that include endangered fish such as sturgeon, endangered birds such as bald eagles, and people.

70 NYSBA The New York Environmental Lawyer | Fall 2017 | Vol. 37 | No. 2

Any long-term project, especially if unusually expensive, must be evaluated periodically to assess the degree to which it is fulfilling its purpose. If it is not fulfilling its purpose, it must be redesigned or terminated. Clamshell dredging was and remains a bad idea for the Hudson River, and has been shown incapable of fulfilling its original purpose of reducing safely and substantially the long-term downstream transport of PCBs. These lessons should be applied to environmental dredging involving PCBs and other emerging contaminants.

Management of emerging contaminants may include removal from commerce and aggressive remediation. © These strategies in any nation may require support via international agreement to prevent displacement of the problem to more permissive nations. Finally, lessons learned from emerging contaminants should be embodied in laws, such as the newly strengthened Toxic Substances Control Act in the United States, as well as in regulations and enforcement to assure that we leave to our descendants a more positive environmental legacy than that left to us.

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Endnote

Portions of this article were published previously: Michaels, Robert A; and Uriel M. Oko. Excessive PCBs in the Hudson River: attributable to incompleteness of dredging, or to seven years of dredging? Environmental Claims Journal, 29(2):115-40, 2017; online: http:/ /dx.doi.org/10.1080/10406026.2017.1307007, 25 April 2017.

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ISSN 1088-9752 (print) ISSN 1933-8538 (online)

2 NYSBA The New York Environmental Lawyer | Fall 2017 | Vol. 37 | No.2

Table of Contents

Page IMPscapey Promise Chiang. ...2ste.0.ncasacesstascaonvesoancossetnosasucosoescucassussdustsssusasoansssovssasstetes@=ss0sv0usessussasates3s10ssos00stsseucssssut=t ToDias¢tausserores 4 _ Kevin Bernstein Message from the Editor-in-Chief .........scssssssssesssssssnessssssnnsessesnsescesssnssscessssnsecessssnucessesssnsesessssssnsescecessnuecccessanuecesseununsceesssansesccses Z Miriam E. Villani Message from the Student Editorial Board .........sesssssssssssesscnnsssnssesensessssnssssnnesssscsensuessenssecssnssessnsvosssnsssssnsssessnsesssnessssnvensenssoessee 8 Linnea E. Riegel

Section News Comments on the NYSDEC Proposed Amendments to 6 N.Y.C.R.R. Part 617 SEQRA Implementing Regulations

Letter to President Trump on Paris Agreement ..........ssssssscssssseesssenneeesesnnnsssescanneccesssssnescecssnnnneccensunnvesscesssnnneesceesssanecscessennes 22 Virginia Robbins Receives Prestigious Feinstone Awatd ........:.ssesssesssessssessseessesssseessesssncsenseenssssnesssnessseessnecsnsessnecensesseseenee 24 New York State Bar Association Environmental & Energy Law Section Report and Recommendations Concerning Environmental Aspects of the N.Y. State Constitution ........sssscscssssseesesees 25 Photos from Forum and Luncheon: Phaneuf, Nasca, Cozzy Receive Section Awards .........ssssssesssecsseessnessesessseeseed 48-49 Photos from the Fall 2017 Meeting in Saratoga Sprimgs.........ssssssssecssssesscsseesssnuesssnscesssneccsnsecsesnsecsssnessnnecssanssssssncsssneeessnsecs 95 Feature Articles Global Climate Change Blog Carl R. Howard Developments in Climate Change: The IPCC Reports......ssssssssssssssessssssnsssescssssnsssessssssnsesssssssnescssssenssescessssnnsescesssssssscsss o Record Warmth and Polar Ice Melt ....sssssssssssssssessssssessessseessesssnseccessssnssescenssnneseceessanseseessssunecsesssssvesecessanaseccessasnassseesssannes 11 The Need to Move from Carbon-Based Energy to Non-Carbon-Based Energy .....ssessssesssssseeese ssencsccnsnnccccccscenccecsescsccnssceseescncenssecececsneessssssstunsustunnnnnonsorssecerseees scesensenee 14 Five-Year Review: Evolving Environmental Law and Advice to “Green” LawyetS......sssssssssssssssesssnecsssssereeeasesnesesreesees 38 * Alexis Saba Asbestos: The Miraculous but Deadly Mineral .........sssssssssssvessessonsnsssssssnnssssessnnessessonsescscessnuusccecsssnusessesssnnsccsessunnescceessannees 46 Walter Mugdan Whatever the Political Climate May Be, Corporate America Is Stepping Up to the Challenge of Climate Change.......sssssssssscsssessssnssssseesssvesssnnsscnsesssssscssnssscesnsecsanssessnesesssnsesesnescsensscessnnecsanessersnescsesss 50 J. Kevin Healy and Brian M. Jacobson Lessons Learned from Legacy Contaminants of Emerging Concern: Hudson River PCB Dred ging..........ssssssssssss0 58 Robert A. Michaels and Uriel M. Oko Legal Pot Industry Bugged by Lack of Pesticide Guidance .........sosssssscsssssssssssenssessessnnsssesecssnnesseccssnnsesseensnnsesssescesonesssensees 75 Telisport W. Putsavage Administrative Decisions Update .........cssssesssesssessseesseesssenesesessnsssssessescsnecsssessuecsuecsssccssecsneceasecessscauecsnccssecseascessesssecessecesnes 79 Prepared by Robert A. Stout Jr. Recent Decisions and Legislation in Environmental Law.........ssssssecssessssesssessseesseessseesseessssssnssssnessusesssescsssssnescnesesessanseese 81 Student Editorial Board

NYSBA The New York Environmental Lawyer | Fall 2017 | Vol. 37 | No.2

Exhibit

04. Michaels, Robert A.; and Uriel M. Oko. Negative Hudson River Superfund remediation effectiveness: clamshell dredging massively mobilized sediments, increasing PCB contamination. Comments on US EPA’s Proposed Second Five-Year Review. Collingswood, New Jersey, The Certified Environmental Professional (Newsletter of the Academy of BoardCertified Environmental Professionals; ABCEP), pages 4-6, September 2017

page 100

The Certified Environmental Professional

Negative Hudson River Superfund remediation effectiveness: clamshell dredging massively mobilized sediments, increasing PCB contamination

Comments on US EPA’s Proposed Second Five-Year Review

Robert A. Michaels, PhD, CEP; and Uriel M. Oko, PhD, PE

This article is derived from our 30-August public comments submitted to EPA:

We have studied the proposal to dredge, and its implementation, since 2007 (Michaels and Oko, 2007, 2010, 2017a; 2017b, in press). Our contributions regarding reasonably anticipated and actual project effectiveness were ignored in the U. S. Environmental Protection Agency’s (EPA’s) first five-year review (US EPA 2012) and in its proposed second five-year review (US EPA 2017). Our studies, ignored by EPA, focused on all stages of the dredging project, starting with EPA's a priori assumptions (Michaels and Oko 2007). We concluded that EPA’s analysis that was used to justify dredging was biased. That conclusion was based upon our findings that critical assumptions made by the Agency were erroneous, and that all identified errors were made in the dredging-friendly direction rather than randomly.

Page 4 - September 2017

CITATION: Michaels, M. Oko.

remediation

Robert A.; and Uriel Hudson River Superfund clamshell dredging massively mobilized sediments, increasing PCB contamination -- Comments on US EPA's proposed Second Five-Year Review. Collingswood, New Jersey, The Certified Environmental Professional (Newsletter of the Academy of Board Certified Environmental Professionals; ABCEP), pages 4-6, September 2017.

Negative effectiveness:

clamshell dredging massively mobilized sediments, increasing PCB contamination rather than decreasing it. Our purpose in providing these comments is to motivate EPA to address the serious concerns that we have expressed both publicly and privately regarding the expected and the actual performance of the clamshell dredging project.

Our 2007 and 2010 peer-reviewed Environmental Practice articles (Michaels and Oko 2007, 2010) predicted that primitive clamshell dredging in the Hudson River would massively mobilize buried PCB sediments, and spread them to an expanding area of river ecosystems that include fish and birds. Clamshells basically are floating backhoes that are useful for navigational dredging. Our 2017 articles (Michaels and Oko 20174; 2017b, in press) analyze the structure of clamshell dredge buckets used in the Hudson River, and the computerized dredge bucket data produced on each closure (the ‘bucket files’). We found that 75-80 percent of dredged sediment is returned to the river in mobile form, rather than removed to waiting barges for off-site disposal.

The New York State Department of Environmental Conservation recently reported to the EPA that GE’s sevenyear clamshell dredging project has failed to meet its cleanup goal, to reduce safely and substantially the longterm downstream transport of PCBs. This has resulted,

Continued from page 4

most notably, in the project leaving excess PCB levels in fish, which will not abate to acceptable levels for human consumption for most of a century. DEC appropriately called for extensive sampling for PCBs “all the way to New York City,” and called on EPA to finish the job and hold GE accountable for cleaning up the Hudson River.

EPA effectively has obscured this reality by failing to monitor dredge mobilization of PCB sediments, instead focusing on ‘resuspension’. As EPA’s Peer Review Panel (Peer Review Panel 2012, page 36) informing the Agency’s first five-year review wrote:

‘Resuspension” vs. ‘mobilization’ might seem like a distinction without a difference... but it makes a huge difference. Massive amounts of dredged sediment fell back to the river bottom rather than being disposed to waiting barges. Only a tiny fraction of this material is detected in ‘resuspension monitoring’ at great distance from each dredge site. Indeed, even this tiny fraction exceeded EPA’s engineering performance standard (EPS) for resuspension, which resulted in EPA changing the standard and the downstream distance of the monitoring location (Michaels and Oko 2010). The massive amounts of sediment dropped back to the river bottom are mobile: they can be and will be moved downstream episodically when storms or other events produce high-flow conditions in the river.

The Certified Environmental Professional

We termed this the ‘sediment mobilization discrepancy’. It represents more than merely a difference between a predicted vs. a measured parameter value. It represents a fundamental inconsistency in EPA’s past justification of the need to dredge versus EPA’s current characterization of the performance of the dredging project. The need for dredging was justified by the observed, persistent mobility of PCB sediments requiring, according to EPA, their removal via dredging. In contrast, in the new context of actual dredging, EPA dramatically has altered its concept of mobility. Mobility in the dredging project is newly quantified by the miniscule fraction of mobilized (‘resuspended’) PCB that is detected at significant distance downstream. Thus, EPA has ignored nearly all sediment and PCB mobilization in evaluating compliance with the Engineering Performance Standard for resuspension. In ignoring mobility of PCB-containing dredge-mobilized sediments for gauging compliance with the resuspension EPS, EPA has ignored a much larger degree of PCB sediment mobility than that which constituted EPA’s most essential basis for requiring, in 2007, remediation of the Hudson River PCBs Superfund Site via dredging.

September 2017 - Page 5

The Certified Environmental Professional

Continued from page 5

dredging project should be predicated upon satisfactory consideration of this emerging public health issue.

The issues of whether EPA should consider the autism association, and whether the officially completed GE Hudson River dredging project should be extended to remediate remnant PCBs, both must be viewed in the context of EPA’s longstanding special mandate regarding children’s health, embodied by EPA’s Children’s Health Risk Initiative (US EPA 2001). In 1997 the Office of Children’s Health Protection was instituted within EPA. Its mission was and remains “to make children’s health protection a fundamental goal of public health and environmental protection... [by] ensuring strong standards that protect children’s health...” In short, EPA must be conservative, not only in protecting the scientific knowledge base, but in protecting public health, including children’s health (Michaels 2017).

All three of our already-published papers (Michaels and Oko 2007, 2010, 2017a), which are critical of EPA’s dredging project methods and effectiveness, are excluded from citation and from consideration by EPA’s proposed “Second Five-Year Review,” just as in 2012 EPA excluded from its first five-year review our two then-existing peerreviewed published papers. We respectfully call upon EPA to respond to our comments in its upcoming response document, and consider our reports in the final version of the Agency’s “Second Five-Year Review.”

Literature Cited:

Michaels, Robert A. Confidence in courts: a delicate balance. Science, 357(6353):764, Letters, DOI: 10.1126/ science.aao3967, 25 August 2017

Michaels, Robert A.; and Uriel M. Oko. Bias in the US Environmental Protection Agency’s Health Risk Assessment Supporting the Decision to Require Dredging PCB-Bearing Sediments from the Hudson River. Environmental Practice (Cambridge University Press), 9:96-111, 2007

Page 6 - September 2017

Michaels, Robert A.; and Uriel M. Oko. Hudson River PCB Dredging: Midcourse Assessment and Implications Regarding Possible Project Continuation. Environmental Practice (Cambridge University Press), 9:377-94, 2010

Michaels, Robert A.; and Uriel M. Oko. Excessive PCBs in the Hudson River: attributable to incompleteness of dredging, or to seven years of dredging? Environmental Claims Journal, 29(2):115-40, 20174; online: http:// dx.doi.org/10.1080/10406026.2017.1307007, 25 April 2017a

phase1dredgingreport_final.pdf, 2010

US EPA. Region 2's Management of Children’s Health Risk Initiative and Related Projects. Office of Inspector General Audit Report, Grant Management, Report No. 2001-P-

00002, 129 pages, https://www.epa.gov/sites/production/

files/2015-12/documents/kidshealth.pdf, 30 January 2001

Authors - Robert A. Michaels, PhD, CEP; RAM TRAC Corporation, Schenectady, NY; ram@ramtrac.com. Uriel M. Oko, PhD, PE; Recycle Management, Glenmont, NY; umoko@nycap.rr.com.

Exhibit

05. Michaels, Robert A.; and Uriel M. Oko. Excessive PCBs in the Hudson River: attributable to incompleteness of dredging, or to seven years of dredging? Routledge, Taylor & Francis Group, Environmental Claims Journal, 29(2):115-40, 2017; online: http://dx.doi.org/10.1080/10406026.2017.1307007, 25 April 2017c

page 104

ENVIRONMENTAI H Routledge CLAIMS JOURNAI

Taylor & Francis Group

Environmental Claims Journal

ISSN: 1040-6026 (Print) 1547-657X (Online) Journal homepage: http://www.tandfonline.com/loi/becj20

Excessive PCBs in the Hudson River: Attributable

to Incompleteness of Dredging, or to Seven Years of Dredging?

Robert A. Michaels & Uriel M. Oko

To cite this article: Robert A. Michaels & Uriel M. Oko (2017) Excessive PCBs in the Hudson

River: Attributable to Incompleteness of Dredging, or to Seven Years of Dredging?, Environmental Claims Journal, 29:2, 115-140

To link to this article: http://dx.doi.org/10.1080/10406026.2017.1307007

saat Published online: 25 Apr 2017.

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