i 10 1^1?, '>-C <­ Superfund Records Center il SDMS DocID 463863 J ,;YT1L: y^W •^W:r-f- HREAK:,, t(/( OTHER: ^^ 9'&^P May 15, 1993

Slieila Eckman and Ross Gilleland Remedial Project Managers US EPA Region 1 JFK Building (HPS-CANl) Boston, Massachusetts 02203

: i .Siiuni ••.Viiiiiim.s .Sirjc; ".iriiiviuin. V.jrn'.iMU 'jr-^Ol-riJiHl Dear Sheila and Ross, •.^!)2l fi.>>;-Ul-i Enclosed are copies of the Lake Champlain Melissa VV. Davis Committee's comments on the EPA's proposed remediation New York Cliuir plan, our technical advisor's report on the plan and preliminary suggestions for the Public and. Scientific vVilliam F. Romond Vermont Cliair Review Committees on the Pine Street Barge Canal Superfund Site. Claire L. Bamett New York Vice Cluiir I look forward to speaking and meeting with both of you soon to develop more of the details for the \ Leslie A. King Vermont Vice Chair review committees. As discussed with Ross, LCC sees the convening of this group as an enhancement to the Peter S. Paine, Jr. existing outreach effort EPA has put in place. We General Counsel feel that implementing such an approach is absolutely necessary to moving us efficiently to a solution that William G. Howland Treasurer has public and scientific acceptance. I know that both of you have a strong desire to resolve this issue Lori M. Fisher in an equitable manner and I hope we can work together Eixecmive Direcior/Secreiary towards that end.

Jri Fisher Executive Director

Enclosures

Printed vn Recvcled Non-Chionne Bleached Paper %g .^s^ May 15, 1993

Mr. Paul Keough Acting Regional Administrator Environmental Protection Agency People ^vorkini:, for John F. Kennedy Federal Building a clean lake since 1963. Boston, MA 02203

14 Souih Williums Sircet Dear Mr. Keough, Burlington. Vemiom 05401-3400 (SO:) 65S-14I4 After carefully reviewing the studies conducted on the site by EPA's various contractors, their analysis pf data, and their conclusions, the Lake Melissa W. Davis Champlain Committee (LCC) concludes that the EPA New York Chair proposed remediation plan is based upon questionable William F. Romond research, is extremely costly both in terms of the Vermont Chair dollar amount and its limited lifespan of thirty years, and would in all likelihood be a cure worse Oaire L. Bamett than the disease. We are encouraged by your recent New York Vice Chair statements that you are flexible to alternative approaches and we urge a continued search with the Leslie A. King local community for creative and appropriate Vermont Vice Chair solutions.

Peter S. Paine, Jr. The Lake Champlain Committee's main concerns General Counsel with EPA's proposed remediation plan are outlined in William G. Howland this letter and further articulated in the enclosed Treasurer May 1993 Aquatec report Technical Review of EPA's Risk Assessment and Proposed Cleanup Plan For The Lori M. Fisher Pine Street Canal Superfund Site. Executive Director/Secretary In addition to commenting on EPA's proposed remediation plan we are also recommending a process intended to move us into and through the next phase of the issue to an effective and acceptable solution. As indicated during our conversations and at the various public infomnation sessions we have held, we urge the convening, of Public and Scientific Review Committees for the Pine Street Barge Canal Superfund Site. We feel that such a group is necessary to meaningfully involve the public in crafting a Vermont solution to the problem and to develop a remediation plan that is scientifically and publicly credible. Details on the shape and function of the review committee are included in the enclosed Lake Chcunplain Committee Proposal for Public and Scientific Review Committees for the Pine Street Barge Canal Superfund Site. We look forward to working closely with EPA, local and state officials and the public in this effort.

•rr],;l \,m.rhl„r, . w?..,.,.^.-^ p.. Six Problems with EPA's Proposed Remediation 1. The plan is based upon several flawed studies that fail to accurately or comprehensively characterize the Barge Canal site. As a result we do not know if the risks to ecological and hximan health have been underestimated or overestimated.

a) The^^leari-up plan was^trd-gg.eredzbecguse^f~EPA~fi-nd-i-ngsjjt ^h;®~> ^-Sslte^poses—aTi"'"unaccept-abLe~ris-k--t0—benthic, inverteSrate^s~——-^Si^^rams, wo-rms-,~sna±rs^ and~insec.tsr^^^^^I£ha.tJll3^eriy't:Re'''se^^ . ; Ho.w.ev.efe,^3-^ EPA—made-th'i7s~j^Udg^emenjt_based_upon__taking only 12 samples>^:::ili;'E~i's~the= op"ifri*bh of^'l^CC'' s technic^j^^S-onsultant^that only three—samples^were~j taken—i-n—a—way-~th"at~'de'finitively showedji^p^uuSlQnjtam±npi:r^'fe3-~wer^ ^^ffe^tirig^,be-nth'i-e~c)rganisms. ^^^_T^|;XKSfell-S3'mprigg^jj^^^^ low -"'tfig '^leve^ the-^f ecl^ai ^government "says ,ppses ^anecorcrgrcai--r-i-sk-.. J^wever, tKeiy We-rer=:fea'ken -from^ areafere'l'a.'ti.vigfv^lFree "o£^"^05^1^3:ar.^eontamination affd threej:3sampi'esr^o^lna€^=prl3Vi*^^^ informati5Gn=:^to—drawjiany;^;^'-"'"-^ coneiU'sa:ons^£i-~dWeK?ne(ed'lmore—i^fo^ the-ext.ent and lev¥l~~of—i contami-na'Ci^. in - the~su-rfacS'^'^e'dimenCs Be"f'or^dl~gging~.up_3he 'siteW b) EPA plans to dig down to a depth of 2 0 feet in the canal to eliminate the risk to the benthic invertebrates that live in the upper s.u^ace — 6-12 inches — of the canal sediments. Coal tar contamination below this habitat layer, although potentially hazardous, presents low immediate risk to the invertebrates. EPA's own studies indicate that soil contamination below five feet presents minimal exposure to animals and other biota. We have found no justification for digging down 20 feet to protect the ecological community that lives in the upper sediments. c) EPA failed to determine if the site poses a risk to human health by inadequately investigating the potential risks to people who breath the air or drink the water. With regard to air, just one 8-hour sampling event was conducted to determine the risk to people who live and/or work in the area. The tests were done at nearly four orders of magnitude higher than state standards — standards EPA is required to meet — rather than employing more sophisticated sampling methods to conduct a sensitive test. With regard to water, EPA determined that the adjacent Lake Champlain waters do not appear to contain elevated__level.s_o.f_tpxic compouTids_from_yie_J|arge_Canal. rHowever ,_Chaj£IqoncluslQ^i^was—reaehed ^by^Saking—a—l-imitgdlnu^er oT"^sampi-es—and—running---tes-ts—wi"^£K:rdete^tijon lim-i-fes--'COnsililerabry~Ei§i^^^than­ fegulred'^to meejb. ; The-"bott"omTilTe~is';—•we-don-'-t-^knovrT'f"^he lake's water"T.s affected by the Barge Canal. We need to, because 50,000 people get their drinking water from an intake pipe approximately one mile north of the site.

2. The plan would destroy a functioning wetland to create a landfill.

a) If built, the containment disposal facility (CDF) will de^troy_^__^ several—functi-ons~of~th'e~ex±sting-wetjg7id3V^ii-^ ^ljOngEt'efmi:Kearj£fi_of--the~sit-e-.—-One~^~^he major functions of^a_w.e.tland_ _i s-2to;;;;^trap_s.eciilnent'si::andl^^ f f.e r i ng—Lake;::;Ch amp l-alrT^froiii" 7;ghe3;slte3:j3n£a5dh'antsii(:aiid^ other sur?a^e~funof~f~ffoSTthe surrounding areas). The wetlands act essentially as a "sink" in which the high concentrations of organic materials absorb contaminants. Walling off and capping the wetland will likely eliminate this buffering capacity and potentially increase the risk of contaminants reaching the lake in the event of runoff events or failure of the CDF. b.),_ALthGugh—by~ea-ppilig3^hie33;7etl"and_and~Bvrilding,.^ CDF7~EPA—p-lans_to r-ml n im-i^e~th'e""adyerse imp act to=^€h e--si-t e-''s-^wi-l-d--l-i--f e-,—-t he—Feii@y^^o#=^ ^th-i-s=^Ha-bit a-t'-^'f fom~aiOirba-n—z ong*^ i ..the^^ghima 1 s that^usejbhe_w.ejtl:andsrrthah—th.e_^s,ite_^in^i_t:^^

=due5tp. the^sca-iS^-nd3;n.t'ens:i4:-y=(3£3Jh'e=p.roposed-cdi"*;'*-^VT^<^ ?;;r^ " pjlo.p.o.s.ejL.-^solut-i-'ori'^iS—thje—ecoloq-ica-li^^^^ f__!Lurb an—re newa-l-JL,^ rSz:i!ng~a-~neiqHtoorh'o^odSi^S5rde?==eo=^m^ """" ~~—"^ ""^ c)EPA:!:Clplah-r,eq.uir.es__the__creat,ion j5_f-45^et]^and_habi.ta.t^'o:ffHs'i£^ make~^u^f.or^des.tr-uction—ofr:tK^^et11and--tbe^^^ How,e^^r7r:iwetd-ands—are—dif.f-icult--to_r.e,plicate—andrri^-tr^^ '^e—w,oud-d—be—ab-l-er=^teo;pfuXl-y—dug^ggite^ti ::;S^^st:in"g3{etland': " '• ^^ 3. The plan will release aromatic toxins into the air as toxic waste is being removed from the canal bottom and uplands soils, potentially endangering public health. a) Activities associated with the construction of the CDF will release Benzo (a) Pyrene and benzene - two carcinogenic by-products of the site's coal tar contamination - into the air. EPA estimates that the concentrations of benzene due to excavation will be over 2,500 times the state standard and the concentrations of benzene over the water in the CDF will be 8 0,000 times- the state standard. Despite these air quality problems, EPA has not developed a plan for mitigating these increased risks to the people who live and work in the area and will need to breath the air. b) Human exposure to the contaminants trapped in the Barge Canal is largely a voluntary risk borne, according to EPA's studies, by people who happen to swim in or fall into the canal. The dredging associated with EPA's plan would potentially create involuntary exposure risks for a large number of residents.

4. The plan involves, building a landfill on unstable, wetland soils which by sheer weight might squeeze toxins out of the marsh and into Lake Champlain. a) The plan raises several engineering uncertainties which have not been addressed.

5. The plan focuses only on treating about 25 percent of the contaminated soil in the Barge Canal. a) EPA's plan should be comprehensive in nature. If treatment is called for, we should attempt to treat a much larger section of the contaminated site. A partial solution which destroys the wetland needs to get all the contaminated wetland. Otherwise the solution itself may mobilize remaining contaminated materials. d) Developed with input from the broadest possible collaboration of scientists, researchers, and the public taking full advantage of new and promising technologies such as bioremediation; e) Relevant to the unique regional and geographic context of the site and the issue located in the state's largest city on the shores of Lake Champlain. The enclosed initial plan for convening this panel is based upon discussions with local citizens. Agency and city officials, the Congressional delegation, the Vermont Water Resources and Lake Studies Center, and the PRP's. We believe that convening such a group would serve to move the process forward in an efficient manner and lead us toward a resolution that is grounded in good science and has community and state support.

In closing, the Lake Champlain Committee would like to thank EPA for the TAG grant which has made our critique possible. EPA's willingness to fund LCC's review illustrates what is right with the process. It is our sincere hope that EPA's next steps will be guided by a strong commitment and openness to public input. We stand ready and willing to work with you and your staff and the local community in crafting the, most appropriate and responsible solution to the Pine Street Barge Canal Superfund site.

jori Fisher Executive Director

Enclosures cc: Governor Howard Dean Senator Patrick Leahy Senator James Jeffords Congressman Bernie Sanders Mayor Peter Brownell ANR Secretary Chuck Clarke Acting DEC Commissioner Jack Long Sheila Eckman Ross Gilleland LAKE CHAMPLAIN COMMITTEE PROPOSAL FOR PUBLIC AND SCIENTIFIC REVIEW COMMITTEES FOR THE PINE STREET BARGE CANAL SUPERFUND SITE

MAY 1993

Overview In order to meaningfully involve the public in crafting a Vermont solution to the barge canal problem, ensure thorough scientific review of necessary studies and future action plans, and provide recommendations on changes to Superfund law and administration, we propose the establishment of a 3-part body which capitalizes on the findings and recommendations of the past twelve years of worl: on this issue as well as the public outreach program that is currently in place. We see this public involvement effort as necessary to moving us forward on this issue collectively in a positive, responsive manner. In addition to securing the best possible solution to the barge canal problem, such a process will avoid wasting time and money, help restore citizen confidence in government, and build a solid foundation of public and scientific support for any remediation efforts at the Pine Street Barge Canal Superfund site. Another benefit in this year of Superfund reauthorization is that the innovations and process we establish here will be generalizable across the country, adding urgency and significance to this approach.

The three elements of the public review structure are outlined below. I. Barge Canal Public Review Committee This group, an enhancement of the existing public communications effort put in place by EPA would be convened by EPA, the State of Vermont, and the City of Burlington by the end of July 1993. Membership would include but not be limited to representatives of the following groups and agencies:

1 EPA 2 State of Vermont, Agency of Natural Resources and others 3 City of Burlington, Mayor's Office 4 Potentially Responsible Parties 5 Burlington City Council iL^ 6 Congressional Delegation ^(\ ,]jU 7 Lake Champlain Committee 8 Burlington Conservation Commission 9 Pine Street Arts and Business Center 10 Lake Champlain Citizens' Advisory Committee 11 Lake Champlain Management Conference 12 Appropriate federal agencies 13 Burlington Neighborhood Planning Assembly 14 Lake Champlain Regional Chamber of Commerce 15 Downtown Burlington Development Association 16 Interested Citizens Specific tasks of the committee will be finalized after the group convenes but the major objectives will be threefold: 1) enhance communication between the public and all interested parties; 2) maintain linkages among EPA, state and local groups; and 3) promote public satisfaction and acceptance of action plans. Tasks for this group should include the following: a) provide ongoing public input into the process; b) relay findings and issues of the Scientific Advisory Panel back to their constituencies to keep the public informed; c) organize public meetings and information campaigns and publicize issues as they arise.

II) Barge Canal Working Group This working group is a continuation of the public outreach and scientific review already established by the Lake Champlain Committee through the Technical Assistance Grant. These ongoing efforts will serve to support and coordinate the work of the Barge Canal Public Review Committee and the Scientific Advisory Panel. This small group will design a work program for the public review process and convene the Scientific Advisory Panel. The Barge Canal Working Group will be staffed by LCC with funding provided by the Technical Assistance Grant. Membership will include LCC board and staff; one designated representative from the Congressional delegation, the State of Vermont, the Burlington Conservation Commission, the Burlington City Council and the Potentially Responsible Parties; UVM and area scientists; and others.

Ill) Scientific Advisory Panel The Scientific Advisory Panel is a technical subcommittee of the Barge Canal Working Group whose role will be to identify gaps in the scientific studies of the barge canal, establish parameters for further studies and monitoring, review proposals for research, and review the link between research findings and remediation plans. The Scientific Advisory Panel will serve as a peer review committee for all additional monitoring and studies conducted on the site. They will feed data to EPA, the State of Vermont, City of Burlington and other members of the Barge Canal Public Review Committee and provide technical advice on the process as it unfolds. The Scientific Advisory Panel will be convened by the Barge Canal Working Group. Membership will include experts in the following disciplines as well as an outside scientific advisor with expertise in waste and risk assessment.

1. Air Emissions 2 Bioremediation 3 Economics 4 Eco-toxicology 5 Fisheries 6) Groundwater 7 Hazardous Waste 8 Human Health 9 1 Risk Assessment 10 Soil Science 11 ) Wildlife Technical Review of EPA's Risk Assessment and Proposed Cleanup Plan For The Pine Street Canal Superfund Site

Prepared for: The Lake Champlain Committee 14 South Williams Street Burlington, VT 05401

Prepared by: Kiilip C. Downey and Roger C. Binkerd

Aquatec Project No.: 93014 Aquatec, Inc 55 South Park Drive Colchester, Vermont 05446

May 1993 Table of Contents

Page Executive Sununairy i 1.0 INTRODUCTION . 1 1.1 Overview of Technical Review 1 1. 2 EPA Superfund Authorization and Tasks 1 1. 3 Documents 2

2.0 REMEDIAL INVESTIGATION/BASELINE RISK ASSESSMENT REVIEW 4 2.1 Ecological Risk Assessment 4 2.1.1 Macroinvertebrates 4 2.1.1.1 Assessment Review 4 2.1.1.2 Technical Evaluation 5 2.1.2 Fish 7 2.1.2.1 Assessment Review 7 2.1.2.2 Technical Evaluation ; 8 2.1.3 Wetlands/Upland Wildlife 9 2.1.3.1 Assessment Review • 9 2.1.3.2 Technical Evaluation 10 2.1.4 Lake Champlain 10 2.1.4.1 Sediment 10 2.1.4.2 Water 11 2.2 Human Health Risk Assessment 12 2.2.1 Soil Exposure 13 2.2.1.1 Assessment Review 13 2.2.1.2 Technical Evaluation 14. 2.2.2 Air Exposure 15 2.2.2.1 Assessment Review 15 2.2.2.2 Technical Evaluation 17

3.0 REMEDIAL DESIGN 20 3.1 Proposed Design , 20 3 . 2 Technical Review 20 3.2.1 Ecological Risk 21 3.2.2 Human Health Risk 23 3.3 Additional Studies 25

4.0 SUMMARY 29

5.0 REFERENCES 30 EXECUTIVE SUMMARY

The overall goal of this evaluation was to review and critique the U.S.EPA's Remedial Investigation/Feasibility Study (RI/FS). The comments on the U.S.EPA's Remedial Investigations focused on the methodologies and the data collected.

There are several significant concerns which we feel the Remedial Investigation/Feasibility Study failed to address: 1. A baseline risk assessment of two important pathways for human health, air and surface water, was not completed; 2T~TlTe~lacl?=of::::documenta-.6ion^concemi-ng-=the-^ -ejctentofsgdimen t=c on-tami-na-t-i on_ in_-the=canal=;=3-? The extent of contaminant migration toward Lake Champlain; and, 4. The potential human health risk from contaminated air during and after the construction of the preferred alternative.

In order to determine the least intrusive methods for remediation, the extent of contamination in the sediments should be known and well documented. The collection of only three acceptable surface canal sediment samples during the two Remedial Investigations provides an insufficient database. It appears that an overly conservative plan (of extensive excavation to 20 foot depths in the southern canal) was adopted in an attempt to provide a 'safe' plan in order to compensate for- the lack of information available and the associated uncertainty.

If remediation of the canal sediments is eventually selected based on additional studies then it should concentrate on remediating only, the habitat where macroinvertebrates live, essentially the upper 6-12 inches of sediment, using the least intrusive means. Remediating only contaminated, habitat and not deeper sediments would serve to minimize impacts to the present biological community which has adapted to the current site conditions.

*'*'^"The construction of the containment/disposal facility (CDF) in the tlands will destroy or at least severely limit several functions of the tland which are critical to the long-term ecological health of this site. Also, from an ecological standpoint, the CDF remedial plan would have a greater negative impact on wildlife use at the site than the theoretical impacts identified in the Baseline Risk Assessment. The construction of the CDF and excavation of soils and sediments will release benzo(a)pyrene, benzene and related contaminants to the air. The U.S. EPA calculated that the benzene concentration over the water in the CDF would be 9550 ug/m3, more than 80,000 times the State standard. Remediation using excavation, dredging, and CDF construction, may substitute a short-term involuntary human health risk for a long term voluntary human health risk; people can avoid entering the site, they can not avoid breathing the air.

There are several important data gaps that should be addressed before U.S.EPA's preferred remedial alternative or any remedial plan be implemented. These proposed studies should not be construed as a proposal to establish the site merely as a study area, or as recommending a 'no-action' alternative. '^The~si"te3dg£S_contal-n'"h^aSax"dous'^~o'ntami-nant-s-^ -which should^be'^remediated-us-ing—the-leas°t°'-^intrjjs'ive methods tKa't^^'wrl-p Vredu'c:e~long'^tefm-ecol"o'g'ical risjc^jJitho.ut,.^,increasingg3^Aljjgltary_and/^or' -involuntary^human^heajl'tli;iorl_e.c.ological* risk. However, without the ­ completion of the baseline human health risk assessment, further characterization of the canal sediments, surface water, and investigation and quantification of groundwater discharge to Lake Champlain along the western boundary of the site, any remedial design proposed would likely be more conservative than necessary to account for the increased uncertainty due to lack of this information.

In summary, the proposed remedial design alternative selected by the U.S.EPA may be overly conservative. Although U.S.EPA's preferred plan may tend to reduce some ecological risk pathways in the long term, it may also significantly increase involuntary human health risk through the release of contaminants to the air. This remedial design alternative could be trading ^off—rel'ative'ly''ilow eco_Is&i^I~^impacts"^for involuntary human health risk to the citizens of Vermont. This potential trade-off is unacceptable and suggests that less intrusive remedial alternatives need to be considered for this site.

ii 1.0 INTRODUCTION

The Pine Street Barge Canal is a Superfund Site located in Burlington, Vermont adjacent to Lake Champlain. Two remedial investigations, a baseline risk assessment, and a feasibility study have been conducted by the U.S. EPA and a preferred cleanup plan has been adopted. The objective of this report is to review the studies and the preferred cleanup plan proposed by the U.S. EPA.

1.1 Overview of Technical Review

This report was generated as part of a Technical Assistance Grant (TAG) awarded to The Lake Champlain Committee (LCC). A technical consultant, Aquatec, Inc. reviewed and critiqued the U.S. EPA's Remedial Investigation/Feasibility Study (RI/FS). Specifically, Aquatec, Inc. was charged by LCC with reviewing the RI/FS to address three basic questions:

1. What data did U.S. EPA collect? 2. Were the data collected adequate? 3. Were the conclusions the U.S. EPA reached technically appropriate?

1:2 EPA Superfund Authorization and Tasks

The U.S. EPA is required to implement CERCLA according to 40 CFR Part 300 - National Oil and Hazardous Substance Pollution Contingency Plan (NCP) . There are specific requirements in the NCP for conducting risk assessments for human health and the environment. As part of the remedial investigation

"the lead agency shall conduct a site-specific baseline risk assessment to characterize the current and potential threats to human health and the environment that may be posed by contaminants migrating to ground water or surface water, releasing to air, leaching through soil, remaining in the soil, and bioaccumulating in the food chain. The results of the baseline risk assessment will help establish acceptable exposure levels for use in developing remedial alternatives in the FS (Feasibility Study) , as described in paragraph (e) of this section." Section 300.430(d)(4).

and,

and "Remediation goals shall establish acceptable exposure levels that are protective of human health and the environment and shall be developed by considering the following: (A) Applicable or relevant and appropriate requirements (ARAR's) under federal environmental or state environmental or facility siting laws, if available, and the following factors:

(1) For systemic toxicants, acceptable exposure levels shall represent concentration levels to which the human population, including sensitive subgroups, may be exposed without adverse effect during a lifetime or part of a lifetime, incorporating an adequate margin of safety;

(2) For known or suspected carcinogens, acceptable exposure levels are generally concentration levels that represent an excess upper bound lifetime cancer risk to an individual of between lO"** and 10"° using information on the relationship between dose and response. The 10"° risk level shall be used as the ' point of departure for determining remediation goals for alternatives when ARAR's are not available or are not sufficiently protective because of the presence of multiple contaminants at a site or multiple pathways of exposure: Section 300.430(e)(i).

Certain criteria are required as noted in 300.430(f)(i)(A)for remedial actions.

(A) Threshold criteria. Overall protection of human health and the environment and compliance with ARAR's (unless a specific ARAR is waived) are threshold requirements that each alternative must meet in order to be eligible for selection.

1.3 Documents

The following documents represented the majority of U.S. EPA reports reviewed:

1. "Draft Remedial Investigation Report - Volume lA," Peer Consultants (May 1990).

2. "Draft Remedial Inviestigation Report - Volume IB," Peer Consultants (May 1990).

3. "Draft Remedial Investigation Report - Volume III," Peer Consultants (May 1990).

4. "Draft Remedial Investigation Report - Volume IV," Peer Consultants (May 1990).

5. "Supplemental Remedial Investigation Final Report - Volume I," Metcalf & Eddy, Inc. (March 1992). 6. "Supplemental Remedial Investigation Final Report - Volume II," Metcalf & Eddy, Inc. (March 1992).

7. "Supplemental Remedial Investigation Final Report - Volume III," Metcalf & Eddy, Inc. (March 1992).

8. "Baseline Risk Assessment," Metcalf & Eddy, Inc. (1992)

9. "Treatability Study - Final Report - Volume I," Metcalf 6e Eddy, Inc. (February 1992).

10. "Treatability Study - Final Report - Volume II," Metcalf 6e Eddy, Inc. (February 1992).

11. "Feasibility Study - Final Report - Volume I," Metcalf & Eddy, Inc. (November 1992).

12. "Feasibility Study - Final Report - Volume II," Metcalf & Eddy, Inc. (November 1992).

13. "Feasibility Study - Final Report - Volume III," Metcalf & Eddy, Inc. (November 1992).

The U.S. EPA risk assessment methodology used at the Pine Street Canal Site referenced guidance contained in the following documents:

"Risk Assessment Guidance for Superfund, Volume I, Human Health Evaluation Manual, Part A." EPA/540/1-89/002, December 1989."

"Supplemental Risk Assessment Guidance for the Superfund Program, Part 1, Guidance for Public Health Risk Assessments." EPA 901/5-89-001, June 1989."

"Standard Default Exposure Factors." OSWER Directive 9285.6-03, March 1991." 2.0 REMEDIAL INVESTIGATION/BASELINE RISK ASSESSMENT REVIEW

2.1 Ecological Risk Assessment

2.1.1 Macroinvertebrates

2.1.1.1 Assessment Overview

Macroinvertebrates were sampled as part of the Supplemental Remedial Investigation (SRI). A reconnaissance survey of tha macroinvertebrate communities was conducted in May 1990. Based upon this reconnaissance survey, three sampling locations in the Canal proper, but none in the Turning Basin, were established even though the reconnaissance survey revealed that the density of macroinvertebrates in the Turning Basin was the lowest observed. The three stations (PS-l,PS-2,PS-3) in the canal were sampled (triplicate Ekman grabs per sampling event) in June and August. The station (PS-1) closest to the Turning Basin displayed the lowest density of macroinvertebrates of the five (3 Canal and 2 Reference) stations sampled in June and the second lowest density in August.

The SRI noted that sampling bias occurred':~-"Additionally,.^.sediment ^sample locations_w.er.e-selectively bia's'e'd^^during^the-SRI^to-areas—tha-t-coul.d sup.por-t^benthic—org"anisms_and_are hdt^neces'sari-l-y—repres.entative o_f-^the^^ —mosfe--e:ontamina.t.ed__sediment"s . " ^When_fr.e.e_'i?Base' cqar t.ar_was^encountere;d~:(-i"rP^ August)~th"e"s"e s'a'mples were not processed, and~sampl-i-ng—was—resumed-upstreanr^^ -wher-e-^better-!!_sample__c.o.ll.ection conditions prevaiTe'd.

The SRI evaluated the benthic data collected by examining taxa and species diversities. The study concluded that "The sediments in the Canal are spatially heterogeneous and the diversity and density of the organisms vary correspondingly. In areas of hea'vy contamination, indicated by the presence of free phase on the sediment surface, abiotic (no living benthos) conditions prevailed. In the rest of the canal, pollution tolerant species, such as tubicifed [sic] oligochaetes were more common." The SRI stated that the reference site had a benthic community composed of a • greater percentage of pollution sensitive species, such as amphipods and odonates; however their analysis did not contain any statistical analyses of the data.

The quantitative model characterized sediment concentrations using 0 to 2 foot core samples obtained in the PEER RI and three Ekman Dredge samples (sediment depth sampled less than 1 foot) collected concurrently with benthic samples during the SRI.

The SRI concluded that " These observed patterns appear to be directly related to contamination of the Canal sediments....[Interim sediment] criteria were exceeded in sampled canal sediments for three (acenaphthene, phenanthrene, and pyrene) of the six PAHs for which standards exist." As stated in the Baseline Risk Assessment (RA) the conclusion reached was that the sediments in the Pine Street Canal are having toxic effects on benthic inf auna. rAs^^drscusseCl^.l^wJ^the—PAH-data—col-l-ec-£ed-concurrently'"wi-th~j jD.enthos__s_amp.ling does noj:_suip.port. this p,o.lu£^

In the Risk Characterization section of the Baseline Risk Assessment (RA), the benthic risk is quantified through the development of sediment Ecological Effect Levels (EEL). The EEL for the canal sediments were based upon the interim sediment criterion for phenanthrene. This model relies on the Total Organic Carbon (TOC) measurements to calculate the relative bioavailability (and toxicity) of chemicals in the sediments. PAHs can be adsorbed onto organic materials (estimated by TOC measurements) present in the sediments which in turn reduces the bioavailability of the PAH compounds; therefore, to characterize risk, both PAH and TOC values are required.

2.1.1.2 Technical, Evaluation

The analyses used in the SRI and the RA suffers from several limitations. Core samples collected as 0-2 feet samples may not adequately characterize the surface sediments (less than 6-8 inches) which provide much of the benthic (and bottom fish) habitat in the canal.

As noted in the Johnson Company report (1992) there were three distinct layers of canal .sediment in their transect located adjacent to the northwest corner of the filled-in barge slip. "The first layer was approximately 6-8 inches thick and it is assumed that this layer was primarily organic in composition. The second layer was very fluid, requiring little effort to penetrate with the sampler and was at least ten feet thick. The third layer was solid..." The second layer noted in the Johnson Company Report was believed to contain high PAH contamination. If the core samples obtained during the PEER RI penetrated to the second layer and then were sampled, these data may not be representative of the first layer where benthic organisms are in greatest abundance.

It would seem reasonable that the three samples collected during the SRI using an Ekman dredge as part of the macroinvertebrate study were more representative of the upper sediment layer.c^^en-^corre'S'te'd^for^TOC -eont'ent.,_the—three---Ekman-'dredge~sampl-es~were~al'l~beigwjzth^ih^ crd-teria. for concentr-at-i-onsS:0.f5si'xrPAHs-t-\(including phenanthrene) based upon the SRI (SRI Table 3-10). This suggests that bioavailable contaminant levels in the upper sediment layer may not be as high as indicated, at least for the three samples collected.

The risk assessment notes that the abundance of pollution tolerant organisms at some of the canal sampling locations is an effect of the contaminants. This conclusion is based on the supporting evidence that three sediment interim criteria were exceeded in the 0-2 foot core sediment samples which contained the highest PAHs measured. L.But'. usTng'^su'ff icalv sediment concentrati'ons2c^llec"ted'~concurrentl'y~and"~i,n jthe_samej.sediment ;j;gye?ITs_.the_bjenthos-r"none~of'"thre^ix~interim__s.ediment-criteria-were exceeded, according to the SRI. These PAH analyses (June samples) were representative of the conditions of the sediment habitat for the benthos since they were collected at the same time, location, and with the same equipment as were the samples analyzed for macroinvertebrates. Therefore, it was not demonstrated that the abundance of pollution tolerant species was a result of natural habitat substrate, or chemicals of concern. The presence of high percentages of pollution tolerant tubificids at some locations may actually have been a result of the habitat conditions measured (silty sediments and low dissolved oxygen levels) and not related to chemical contamination.

Another question regarding the risk assessment is whether the exposure of organisms (benthos and fish) was adequately quantified. If free product exists in the surface sediments, what was the spatial extent of the reduction in benthic habitat? Was contamination limited to several square feet or was contamination widespread throughout the canal bottom? With the sampling of the benthos/sediments as reported in the SRI, how can the magnitude of the risk to the benthic community be assessed? 2.1.2 Fish

2.1.2.1 Assessment Review

The objective of the fisheries study conducted in the SRI was to examine whether the abundance and diversity of fish found in the canal were similar to a selected reference site, Malletts Creek. A fisheries study was undertaken to document the abundance of fish in the Pine Street Barge Canal (Canal) and at the Malletts Creek (Reference) site. Both sites were sampled in June and August using minnow traps, gill nets, and boat-mounted electrofishing gear.

The total number of fish captured during the two sample periods was more than three times greater at the Pine Street Canal than at the Reference site. Yellow perch and golden shiners were predominant species at both sites. Four species were collected at both sites while three species (bowfin, chain pickerel and smallmouth bass) were reported at the Reference site only. White perch, northern pike, rock bass, white sucker, emerald shiner, blacknose shiner, brown bullhead and chanhel catfish were reported from the Pine Street Barge Canal only.

In addition to the fish sampling effort noted above, field personnel collecting macroinvertebrates in May reported the presence of small (larval ?) fish present in the canal. We assume these fish were not collected, which is unfortunate since identification would have documented reproduction success in the canal for one or more species.

There is a fish identification discrepancy in the SRI data. The chain pickerel were misnamed scientifically as Esox lucius (which is the scientific name of the northern pike) rather than its accepted scientific name of Esox niger. It is therefore unclear whether these fish were really misnamed chain pickerel or if they actually are northern pike.

Whole body samples of yellow perch, golden shiners, pumpkinseed, rock bass, and catfish from Pine Street Barge Canal were analyzed for selected polynuciear aromatic hydrocarbons (PAHs). Florene (24 ug/Kg) and chrysene (6.7 ug/Kg) were each detected once in the fish sampled. Pyrene (320 ug/Kg) was found in one of the thirteen golden shiners collected.

Yellow perch, golden shiners, pumpkinseed, and bowfin were analyzed for the same 16 PAHs analyzed as in The Pine Street Barge Canal. No detectable concentrations of any PAH were reported.

The RI study concluded that compared with the Reference site, the fish community at the Pine Street Barge Canal Superfund Site has as many, or more, species present, and fish were consistency more abundant on the Pine . Street Canal Superfund Site as well. Also, the study noted that the presence of larval fish of species which spawn over submerged vegetation indicated that the Canal serves as a fish nursery area.

2.1.2.2 Technical Evalxiation

The fish study does show a similar diversity and abundance of fish in the Canal relative to the reference station chosen. Certainly, the legitimacy of comparing the reference site habitat to the Canal habitat is questionable, but the number of fish and species of fish found were what might be expected in near-shore areas in Lake Champlain.

The intended SRI field study goal of measuring the relative abundance and diversity of fish in the Canal during the two times sampled was met with the SRI. Fish abundance and diversity was equal to or greater than the reference site in the samples collected.

There was no evidence that fish were significantly bioaccumulating any of the PAHs in the Canal. This result is not surprising since, as noted in the SRIv2'frsh-^have-_the-.abil-i-ty—to-metabol-i-ze-and^de'gfa3e„PAl(i3PFor example, in-bluegill sunfish an 89 percent loss of benzo (a)pyrene was recorded in 4 hours after exposure in controlled experimental conditions, ,>^-^e7r"e"fore7?f->igtv-tri-ssue-.bloac.cumuj^^ for PAHs at this sitB.^Howeve-E-r--the'-rae'tabol-rte"s~^f~PSHs*"were--not_tes.te.d__J '^lCZf°£lIJ^li£JSgIi^e~ti'ssu'e" a^ialy_ses,jn_qr_was~"tRe;^ri'sk~from~these—compounds mea'sured-r—Many—of,^these--compounds-are-also-cons-i-dered-ca-rcinogejtis^

Although there are several studies that correlated tiimor growth with elevated levels of total and carcinogenic PAHs-;—gro'ss-"fi"sh":he"al-th-was'^no"t^ ]Tgparte"d-or-di-scussed--in--detai-l-—i-n-the-SR-I- Also-,-^as noted in the evaluation of the SRI benthic studies, the actual sediment concentrations that are present in the upper layer (several inches) to which fish (and other aquatic organisms) may be exposed were quantified in only three samples in the Canal. As with the benthos, the question arises concerning the accuracy of such limited spatial measurements for determining the magnitude of risk.

2.1.3 Wetlands/Upland Wildlife

2.1.3.1 Assessment Review

Beaver, muskrat and mice were qualitatively sampled through systematic observations and limited trapping (for mice) at the Pine Street Barge Canal site. There was ample evidence of beaver use throughout the site. These observations included signs of beaver feeding. There were a minimum of seven lodges (plus a dam) on site, and beaver were frequently, seen. .The colony consists of a minimum of 5 individuals; a resident pair and three subadults. The SRI concluded that despite the potential exposure to site contaminants, there was no evidence of overt effects on the beaver colony.

Muskrats were observed on both the Pine Street Canal and the reference site. However, data were insufficient to compare the relative abundance at the two sites due to the limited observations at the reference site. Muskrat were encountered less frequently than expected although this can not be definitively attributed to Site contamination. The lack of water level stability in the southern section of the canal, the most suitable habitat, may also be a factor.

Muskrats were among the species with the highest potential exposure to site contaminants. The SRI stated that there was insufficient data to conduct a complete evaluation of the measurement endpoint for this species.

The Peromsycus mice are common rodents and utilize non-inundated woody areas along both sides of the canal. A total of eight mice were caught during trapping efforts. None of the mice exhibited any gross abnormalities. According to the SRI, the presence of a lactating female and several immature mice in the sample shows that this species is also o successfully reproducing on site. The SRI concluded that the measurement endpoint (observed use of the site) was satisfied for this species.

A quantitative assessment using critical exposure pathway models was used to estimate theoretical exposure to animals on site through dermal, ingestion, and inhalation pathways. Since many of these models have not been fully developed for these animals, several assumptions about exposure and exposure effects were made by the U.S. EPA, The resultant model calculations for each exposure pathway for the muskrats, beaver, and mice were then compared to measured site concentrations to judge potential risk. The model results indicated that there were theoretical potential exposure effects for the muskrat in the wetlands and the beaver in the wooded wetlands. Also, maximum site contaminant levels in the upland soils exceeded the ecological effects levels for the mouse, but average soils concentrations did not, suggesting localized areas of higher contamination.

2.1.3.2 Technical Evaluation

Generally, the on-site qualitative assessment indicated acceptable baseline site conditions for the animals studied with the exception of the muskrat. The qualitative assessment of muskrat was inconclusive due to the lack of number of observations on the presence use (at the reference site).

However, the ecological effects models were in direct contrast with the qualitative assessment indicating potential adverse effects by site contaminants for the wetlands. These theoretical effects which were used to set cleanup goals for the wetlands (and uplands) were not supported by the observed use of the site by the representative animal communities. We do not agree with the Risk Assessment's approach of using the theoretical risks for site characterization rather than the obseirved animal use of the site. vOn—the-contrary,_we_b.el.ieve—that-on-site-measurements_aiid^ •"Observation's oh vri"ldlTfe~arg~more~apprbp£iate^rnxas:sles.slng^^^ -condi-e-ions_and_^,G£l5Jg£ca±^r.isk'*-at-the-S'tteT' j

2.1.4 Lake Champlain

2.1.4.1 Sediment Analyses

r---TTie~s^diments~6rffiake7ehamp-l-ain-were—s^

The samples which had the highest sediment concentrations in the Lake ^^^^dtm'ents-samp-l-ed--were-nea-r--the—Burlingt6Tr"Sewerage-0ut-fall^ The sample at

10 the mouth of the canal did have detectable concentrations of total PAHs (3400 ug/kg) which suggest some minor contamination in this sample. But, due to other sources (like the sewerage outfall pipe, or the CSO) of PAHs in lake sediment samples besides the Barge Canal site, the true extent of off-site migration may never be fully documented.

The analysis of off-site sediment impacts were based on only seven samples. The Peer RI data (two of the seven off site sediment samples) were conducted at very high detection levels; for example, detection levels ranging from lOOOOUJ to 12000UJ ug/kg were reported for phenanthrene. Although the number of samples is low and detection level high, there does not appear to be significant ecological risk.

2.1.4.2 Water

Seven reported Lake water samples were collected during the PEER RI. None of these seven samples had detectable concentrations of PAHs. One of these seven samples, SW-025, was located directly west of the mouth of the canal entrance. Many of the compound detection levels were labeled "UR." The "U" indicates undetected and the "R" indicates the result was rejected during data validation. In other words, "R" data are worthless.

Eisler (1987) proposed a somewhat controversial approach that human health drinking water criteria be adopted for wildlife since much of the data on drinking water risk has come from animal experience. This approach has not been generally accepted to our knowledge but, if this approach was used here, it would show that the detection levels used for surface water were many orders of magnitude higher than human health drinking water criteria. ^Con'gequenjEly, .they are oT~lTtg:l'y''vglue^for^^^<^^ogi-cal^ assessment.

National EPA has developed an ambient water quality criterion (AWQC) to protect human health (ICF-Cleraent, 1987) for water, fish and shellfish consumption. The criterion is the sum of the concentrations of total carcinogenic PAHs corresponding to upper-bound lifetime excess cancer risk of 10"5, 10"6, 10-7 and 28, 2.8 and 0.28 nanograms per liter (ng/L), respectively. Also, the State of New York has recommended a guidance level of 0.2 ug/L (200ng/L) for the sum of six carcinogenic PAHs plus pyrene and fluoranthene (ICF-Clements, 1987). In the PEER RI the detection level for each of the individual PAH compounds was 10 ug/L. This individual detection level is 50 and 3500 times higher than New York's guidance and EPA's AWQC (10"^ risk) reported. Therefore, according to the approach suggested by Eisler (1987) the sampling and analytical methodologies were not sensitive enough to evaluate ecological risk (or incidentally) human health risk.

2.2 Human Health Risk Assessment

Calculation of risk involves two factors: dose and degree of risk as represented by the slope factor. Dose depends on many factors, two of which are concentration of the contaminant and exposure to that contaminant. But bother factors are needed to produce a dose. For example, a contaminant may be found at high concentration but, if it is buried, may have low exposure to a population; consequently, the dose may be low. The concentration may also be low, but if the exposure is over a very long period of time, the dose may be high. For example, daily consumption of drinking water, contaminated at even very low level, can provide a high dose to an individual during a lifetime. Once a dose is calculated it is multiplied by the "slope factor." The slope factor is obtained from toxicological studies which correlates dose and risk. The result of this multiplication is risk.

Chemicals of concern (COC) were selected based on analytical results of samples collected at the site. For these chemicals, only benzene and benzo(a)pyrene (B(a)P) had slope factors published in IRIS (Integrated Risk Information System). Without slope factors carcinogenic risk cannot be calculated. The slope factor for six other Polynuciear Aromatic Hydrocarbon (PAH) compounds was assximed to be the same as B(a)P based on similar chemical composition. The slope factor for benzene (Type A known human carcinogen) is 2.9 X 10"^ risk/(mg/kg/day) and for B(a)P (Type B, suspected hxjman carcinogen) is 5.4 risk/(mg/Kg/day). Thus B(a)P slope factor is 186 times 5.4/(2.9 X 10"^) as potent compared with benzene. The compounds with the highest apparent contribution to health risk were: Contaminant of Concern (COC) Slope Factor/(mg/Kg/dav) Benzene 0.029 Benzo(a)pyrene 5.4 Benzo (a) anthracene 5.4* '' Chrysene 5.4* Benzo(b)fluoranthene 5.4* Benzo(k)fluoranthene 5.4* Dibenzo(a,h)anthracene 5.4* Indeno(l,2,3,-c,d)pyrene 5.4*

* Assumed Slope Factor

The EPA then selected fifteen exposure pathways for quantitative analysis of COC dose for each pathway. Some pathways had exposure to the same population. Dose from multiple pathways to the same exposed population were added, then multiplied by the slope factor for the COC to calculate risk for a COC.

• In three steps:

1. The total dose for each COC was the sum of partial doses obtained from each pathway for each COC.

2. The total dose for each COC was then multiplied by the slope factor for each COC to estimate risk for that COC.

3. Finally, 1 and 2 were reported for each COC, then all the partial risks were added to estimate the total risk.

2.2,1 Soil Exposure

2.2.1.1 Assessment Review

The data collected at the site are described in the "Supplemental Remedial Investigation, Final Report" March, 1992. Sediment, soil, surface water, ground water and air samples were collected and analyzed. Samples were collected both on site and from locations representing background conditions.

Site surface soils were defined as samples collected from depths of zero to six inches. These samples are listed in Table 4-2 of the RI study report. The individual values for benzo(a)pyrene for these stations are listed in Table 1 but the actual values used in the EPAs calculations were based on arbitrary ways of treating undetects and duplicates results. Data (most likely) used in EPA's risk assessment are listed in the second column. Duplicate results were averaged; for undetects, one half the

1 7 reported detection limit was used. As noted, only one value, SS005, had a known concentration; no qualifiers were attached. In comparison, the value for station SDOOl, 41000U was converted to 20500 ug/Kg for averaging. The resulting mean value of 2300 ug/Kg based on the information in Table 1 is close to the mean value calculated by the EPA of 2248 ug/Kg.

2.2.1.2 Technical Evalxiation

Using an undetected value of 20500 ug/Kg, which is six times the value of the only unqualified detected value of 3400 ug/Kg, is not appropriate. Dropping undetects and rejected values, and only using the one detected value and the 22 estimated (J) values yields a mean of 1228 ug/Kg, about half of the value used in the EPA risk assessment (2248 ug/Kg).

In spite of these conservative averaging techniques, the results of the exposure dose and response scenarios that were examined by EPA indicate low risk, mainly in the range of 10"^ to 10"^. The few scenarios above lO"*^ (those represented by maximum concentrations) could be easily calculated to fall well below 10"'^ with alternative, but equally conservative scenarios as those selected by EPA (e.g., by reducing the time during which on-site workers are exposed to highly contaminated soils).

Present risk estimates using average values are about 3 X 10"^; clean up goals (7 X 10"5) are higher than this risk. Only when comparisons are made with maximum concentrations is reduction in risk after remediation evident. Site remediation is not mandated by present threats of excessive risk to human health.

Further evidence that human exposure to site soils is not the motive for remediation, is the fact that present background concentrations of PAH compounds (i.e., actual PAH concentrations in surface soils found off site) are above clean-up goals. The list below are the values of B(a)P found in background surface soil samples. Background Benzo(a)pyrene Station ug/Kg BSOOl 150J BS002 76J BS003 75J BS004 400J BS005 700J BS006 420J BS007 86J BS008 llOJ

The clean-up goal for B(a)P is 300 ug/Kg for the RCO (Recreation, conservation and open area) and 500 ug/Kg for the industrial sites at a risk level of 10"°; therefore, background values (e.g., 700J ug/Kg) exceed the 10"° clean-up goal. Also, total carcinogenic PAH in background samples of 4900J ug/Kg (siom of seven PAH compounds) exceed the 10"° risk level at a concentration of 3500 ug/Kg for the industrial site and 2000 ug/Kg for the RCO. ,

Background samples indicate greater than 10*° risk, but clean-up goals in the document dated November 1992, "EPA Proposes Clean-up Plan For the Pine Street Canal Superfund Site" indicates that a risk level of 7 x 10*^ was selected for determining clean-up goals (Table 2). At this level of cleanup there is essentially no reduction in risk based on average site concentrations; and, only about one order of magnitude reduction of risk based on maximum concentrations.

Table 2. Summary of risk assessment of surface soils based on maximum and average concentrations, and site clean-up goals.

Excess Excess Cancer risk Cancer risk based on based on Site Exposure maximum average Clean up Location Receptor concentration concentration goal

Individual area soils Employee 2 X 10"^ . 3 X 10'^ 7 X 10*5

Site Surface Future Site Soils Future Visitor 1 X lO-*^ 6 X lO'^ 7 X 10-5 RCO User

2.2.2 Air Exposure

2.2.1.2 Assessment Review

Were all the exposure pathways investigated adequately? And, are

15 Table 1. Evaluation of surface soil concentrations of benzo(a)pyrene.

Numeric Value Probably Used In Value Reported* Risk Assessment** Known Concentration Station ug/Kg ug/Kg ug/Kg

SSOOl 320 J 320 SS002 1200 J 1200 SS003 730 J 730 SS004 160 J . 160 SS005 3400 3400 3400 SS006 360 U 180 SS007 66 J 66 SS008 71 J 71 SS009 340 UR SSOIO 120 J 120 SSOll/12 658 J/600 J 629 SS013 180 J 180 SS014 1000 U 500 SS015 720 J 720 SSbl8 6200 J 6200 SS020 1400 J 1400 SS021 270 J 270 SS022 1200 J 1200 SS023 42 J 42 SS027 1500 J 1500 SS028 53 J 53 SS029/30 . 14000 UJ/7000 UJ 5250 SS031 6100 J 6100 SS032/33 310 J/870 J 590 - SDOOl 41000 U 20500 SD006 18000 UJ 9000 SD017 13000 U 6500 SD018 809 U 405 SD019 1500 J 1500 SD020 1800 J 1800 SD022 1200 U 600 SD030 250 J 250

Mean - 2300

** Probable values used; tabulation of values used was not found in risk assessment report. * Qualifiers

J - quantination is approximate due to limitations identified during laboratory analysis or data validation

U - undetected

R - Rejected

16 ARAR's being met? The air pathway was not adequately addressed. Here are some facts:

1. The Hazard Ambient Air Standard (HAAS) for benzo(a)pyrene i s0.0003 ug/m-^; The HAAS for benzene is 0.12 ug/m-^..

2. Benzo(a)pyrene has been measured at levels of 0.003 to 0.005 ug/m^ in downtown Barre, Vermont. (See Ambient Air Quality Monitoring for Polynuciear Aromatic Hydrocarbons at the Gas Company of Vermont site in Barre, Vermont; for AIAC, Inc., Aquatec, Inc., 1988.) Benzene was measured at 4 ug/m3 to over 8 ug/m-^ in the same study; both values exceed State HAAS.

The following statement is found in the Supplemental Remedial Investigation (RI): "The EPA found that PAHs were not detected in either the upwind or downwind samples at a detection limit of 0.2 ug/m^" (page 4-55, Section 4.2.9.1). This statement, although true in and of itself, is trivial, as the State standard is almost four orders or magnitude lower than EPAs detection limit for certain compounds. Air sampling methods, as shown above, are available to quantify B(a)P at levels below State standards, but these were not used.

Also in the Supplemental RI (page 4-55): "In summary, the EPA concluded that volatile organics and PAHs present in the study area are not significantly impacting air quality. The data shows that there were virtually no differences in the levels detected at the three downwind sampling stations when compared to levels detected at the background sampling station." This conclusion was reached based on one eight hour sampling event, 15 August 1990, which included four stations.

2.2.2,2 Technical Evaluation

One sampling event with relatively high detection limits is not adequate to determine whether or not the site is presently emitting volatile organic compounds (VOC) and/or PAH compounds.

It is interesting to note that the Draft RI by PEER reached the conclusion that the site was emitting semivolatile compounds. The PEER ' data were not used in the Supplemental RI and apparently their conclusion was rejected. Even though their conclusion was rejected, the data were valid and should have been used in the Supplemental RI.

17 Comparing PEER'S data on semi-volatiles to data collected in Barre, VT near City Park indicates that for the compounds quantified in both studies, similar results were generally found (see below),

Pine Street Barge Canal PEER Data Average Barre, VT Concentration At City Park Ratio Compound ug/ra3 ug/m3 Pine/Barre

Naphthalene 0,203 0.640 .32 2-Methylnapthalene 0,083 0.470 .18 Acenaphthylene 0,001 0.056 .02 Acenaphthene 0,005 0.012 .41 Fluorene 0,006 0.027 .22 Phenanthrene 0,012 0.041 .29 Anthracene 0,028 0.0055 5.09 Fluoranthene 0,003 0.012 0.25 Pyrene 0.002 0.013 0.13 Benzo(a)anthracene 0.0003 0.0034 0.09 Chrysene 0.0007 0.0044 0.15

Benzo(a)pyrene 0.0033 Benzene 8.6

Benzo(a)pyrene was detected in these same Barre samples at 0.0033 ug/m-^, ten times the State toxic air standard which is based on 10"° risk. Benzene was detected in Barre at 8.6 ug/m3; over seventy times the State toxic air standard. Based on this•information, it is likely that benzo(a)pyrene and benzene are present at the Pine Street site at levels at least one-tenth to that measured in Barre, Vermont; close to the state standard for B(a)P which is 0.0003 ug/m3 and seven times the state standard for Benzene which is 0.12 ug/m3. One tenth of Barre concentrations is conservative since the average ratio (dropping the low and high ratios) is 0.22, or over two-tenths.

Ambient air near the Barge Canal site most likely exceeds toxic air standards for benzene and benzo(a)pyrene. There are not sufficient data to conclude that the site is not emitting air contaminants. In fact, based on qualitative statements on the odor from the site, it is likely the site in its present state is emitting volatiles and semivolatiles. Since State toxic air standards have been accepted as ARAR's, present conditions may

18 already exceed ARAR's, If this is indeed the case, then alternative remedial options (e,g,, soil vapor extraction) may need to be investigated further in regards to their feasibility for reducing site air emissions. 3,0 REMEDIAL DESIGN

3,1 Proposed Design

The site remediation plan is based upon remediating the perceived ecological risk at the site. This plan calls for the excavation of a portion of the canal and capping a portion of the wetland. In the southerly portion of the canal excavation of soils to 20 feet below the canal bottom is proposed. In the northerly portion of the canal excavation of 5 feet of sediments/soils is proposed. These soils are to be placed in a Containment/Disposal Facility (CDF) built on the wetlands near the southerly portion of the canal. The wetlands in this area will be capped and walled off using pilings driven to 40 feet deep. The excavated soils in the canal and elsewhere on site will be replaced with clean soil and sediment.

• The preferred cleanup alternative was selected in order to remediate ecological risk to animals inhabiting the wetlands and the aquatic invertebrates in the sediments in the canal bottom. This preferred cleanup alternative entails locating a containment/disposal facility over the most heavily contaminated portion of the site, principally the wetland area west of the former coal gasification plant where subsurface free phase contamination was found. , The remedial design proposes containment of contaminants, with some free phase recovery, but it does not appreciably treat the contaminants at the sice.

3.2 Technical Review

There are several significant concerns which we feel the Remedial Investigation/Feasibility Study has failed to address: 1. The baseline risk assessment was not completed for two important pathways for human health, air and surface water. 2. The lack of documentation of the extent of sediment contamination in the canal.. 3. The definition of the western boundary of the site. 4. The potential human health risk from air during and after the construction of the preferred alternative. These concerns will be discussed individually below.

20 3.2.1 Ecological Risk

One of the major concerns with the preferred remedial alternative is the plan to excavate the sediment and soils up to 20 feet deep to remediate the risk to benthic macroinvertebrates which are only in the surface layer. , We believe that any remediation of the canal sediments should concentrate on only the contaminated portion of the habitat. Tlie least intrusive means of remediation should be selected to minimize additional impacts to the ecosystem. Remediation plans should also consider recolonization opportunities.

To determine the least intrusive methods for remediation, the extent of contamination in the sediments should be known and well documented. The extent and level of contamination in the surface sediments has not been completely characterized. Only three acceptable surface sediment samples were collected during the two Remedial Investigations. A risk assessment based on three samples does not have adequate information to assess the most appropriate plan to mitigate the ecological risk to the benthic macroinvertebrates (or fish and other exposed wildlife). It appears that an overly conservative plan (of extensive excavation) was adopted in an attempt to provide a 'safe' margin of error in-order to compensate for the lack of information available and the associated uncertainty.

As previously stated, the remedial plan should focus on remediating the potential ecological impacts in areas where exposure might occur. We believe that any remedial plan adopted should remediate the sediments where macroinvertebrates are living, i.e., in the upper surface (6-12 inches) sediments on the bottom of the canal. Contamination below this habitat layer, although hazardous, presents low immediate risk to the macroinvertebrates living in these sediments. In the baseline ecological risk assessment, the U.S. EPA also recognized that soil contamination below 5 feet presents minimal exposure for the animals and other biota and was not seriously considered in characterizing ecological risk.

If the extent of free product contamination is eventually documented and found to be localized, then alternative less intrusive measures for remediation of the canal sediments could be considered. Alternatives may include the recovery of free product in these localized areas while the remaining canal bottom habitat might be remediated by the placement of clean sediments having a high total organic carbon content in the 6" to 12" in depth layer (depending on water depth). This alternative could provide high quality habitat for the benthic macroinvertebrates and additional buffer between organisms and the chemicals below. However, the feasibility of this proposed alternative would depend upon the extent of free product in the upper sediments and the final depth of water after placement of new substrate.

The construction of the CDF in the wetlands will destroy or at least severely limit several functions of the wetland which are critical to the long-term ecological health of this site. One of the major functions of a wetland is to trap sediments and toxic materials. In effect, this buffers Lake Champlain from the site contaminants and other surface minoff from surrounding areas. Theoretically, wetlands act as a 'sink' with the high concentrations of organic materials present adsorbing the contaminants and reducing the contaminant mobility and export to various habitats. Walling off and capping this wetland might eliminate the sediment trapping and water quality improvement function of the wetland. The loss of this natural buffering capacity of the wetland may actually increase the risk to the lake should contaminants from the site be mobilized, for example, by the failure of the CDF, and/or from runoff draining onto the site from surrounding roads and residential areas.

Presumably, the capping of the wetland and construction of the CDF on the wetland is to minimize the adverse impact of the site on the wildlife that uses the wetlands; however, the impact of the construction of the CDF may have a greater impact on wildlife by eliminating the wetlands. From an ecological standpoint, the CDF remedial plan would have a greater impact on wildlife use at the site than the theoretical impacts identified in the Baseline Risk Assessment.

It is recognized that EPA's preferred plan will require the creation of wetlands habitat on-site to mitigate the loss of the

22 wetlands where the CDF is proposed. The new wetland may not be in a place to mitigate urban runoff and due to imperfect understanding of the complexity of the wetlands it may not be constructed to completely replace the functions of the wetlands on the site. A wetland created elsewhere will do nothing for improving the functionality of the Pine Street wetland site in the southern canal area, the site of major concern.

One alternative that has been proposed for the site, is the improvement of wetland habitat for wildlife as part of the mitigation. Removal of vegetation such as Phragmites spp. and replanting with vegetation having high wildlife value would be appropriate for remediation of the wetlands habitat. This removal and replanting of vegetation must be done carefully to insure that the upper soil layer disturbances are minimized and does not increase the mobility of the contaminants underneath.

3.2.2 Human Health Risk

In the remedial construction phase, excavation, dredging, and mixing excavated soil with dredged sediment in the CDF will all be activities where both volatiles and semivolatiles will be released to ambient air. Since the ambient air already is most likely "above State toxic standards, these activities would be adding toxics to an already higher than desirable level.

Calculations of emissions of benzene in the Feasibility Study (FS) indicated that emissions of benzene may be 1.46 pounds per hour; the State action level is 0.0096 pounds in eight hours. B(a)P was calculated to be emitted at a rate of 8.8 X 10'^ pounds per eight hours; the State action level is 25 X 10"^ pounds per eight hours. The EPA's calculation of one year average benzene concentration in air due to excavation was 300 ug/m-^.

Benzene in air above the CDF lagoon was calculated to be 9.55 mg/m^ (9550 ug/m^). The State HAAS value is 0.12 ug/m^; therefore, a dilution of 80000 would be required to reduce benzene in air above the lagoon to acceptable levels (assuming a zero background which is not the case) by the time it reaches the site boundary. This magnitude of dilution is not likely since site boundaries (e.g., Pine Street) are so close to the proposed CDF.

Additional calculations in the Supplemental RI indicates that the risk due to inhalation of benzene for one year exposure during remediation (without controls) would be 4 X 10"^; for benzo(a)pyrene the risk was 1 X 10"^. This calculated risk, induced by site activities, exceeds present site risk for surface soil exposure (average conditions).

The CDF, after construction, may also be a source of air toxics. The Supplemental RI report states "a gas vent layer may be necessary to control toxic gases released from dredge materials."

Apparently, many issues that involve air have been deferred until final design. Controls of air emissions during remediation have been discussed in the RI/FS, but estimates of toxic air release have not been addressed at this time. This attitude is reflected in the following statement (page 6-22 RI/FS) in discussion of air emissions from the lagoon.

"These preliminary results were determined using conservative assumptions as presented in Appendix E. The results suggest that VOC emissions may pose a problem under this alternative under worst case conditions. Contingency measures should be developed in the unlikely event that airborne concentrations exceed site action levels. These measures would include the application of a temporary foam which would be capable of suppressing volatile emissions over the water surface of the sedimentation basin if site action levels are exceeded."

The EPA has stated that if site action levels are exceeded, then controls will be implemented. What are the site action levels for air? These are not given in the RI/FS and apparently were deferred until final design. If site action levels are chosen at levels similar to State toxic standards (or even one or two magnitudes higher) the EPA has not demonstrated their ability to consistently measure at this level, and impacts on the exposed population could go undetected. It is likely chat site action levels will be set at levels that field instruments can detect; for air, these are generally

24 in the parts per million (ppm) range, whereas State toxic standards are in the parts per trillion range (six.orders of magnitude lower).

A "wait and see" attitude seems to have been adopted to address risks of air emission from remediation activities. The assumptions on air emission risk may be conservative and the risk may be overstated, but if this is the case for air, then is it not likely that the results of the risk assessment for site surface soils, which is driving the human health risk assessment, are also overstated? Why is remediation being proposed to reduce risk from surface soils based on conservative assumptions yet when equally conservative assumptions are made for air impacts, results are essentially dismissed?

3.3 Additional Studies

We believe that additional studies need to be completed in order . to ensure that the most appropriate design to remediate the potential risk to the biota and humans is selected. Without these studies and resultant data, the selection of any remedial alternative may lack complete scientific basis and be inappropriate to reduce on site risk. All studies should be designed to achieve a confidence level of 80 to 90 percent that the results are 10 to 20 percent of the true value of concentration or areal extent.

The EPA has not completed the Human Health. Risk Assessment for the air and surface water pathway. The baseline human health risk assessment should be completed for the air and water pathway. Other studies are needed to fill data gaps that are important for accurately assessing risk and remedial design alternatives. These studies are discussed below.

1. The air pathway for hiunan health was dropped early in the remedial investigation process and should be completed.

Air contamination at the site should be monitored at locations both up wind of and downwind of the site. Field instrumentation should include equipment which has both the precision and accuracy to differentiate among various volatile compounds. An Air Pathway Assessment (APA) should be conducted using EPA's guidance manuals (see Volume 1-4; Air/Superfund National Technical Guidance Study Series, Report ASF-/a). These manuals are comprehensive and a complete APA work plan cannot be included in this document. However, using the APA procedures, ambient air should be monitored and emission rates from the site should be measured using flux chambers and calculated from on site soil concentrations to complete the Baseline Risk Assessment. Worst case conditions should be investigated first to obtain an upper estimate of emissions. If these estimates are low and low baseline risk to human health is determined, then additional work may not be required.

2. The hydraulic connection between ground and surface water at the western boundary is unknown and needs to be determined.

Monitoring wells along should be constructed the western edge of the site along the railroad bed. Monitoring should include seasonal measurements of well elevations and the concentrations of organic contamination. Estimates of groundwater discharge to the lake should be estimated based on these hydrogeological data. Mass loading of contaminants can then be estimated based on concentration of contaminants in groundwater and discharge.

3. Due to the limited nature of the surface water sampling conducted during the Remedial Investigations additional studies are necessary to examine off-site migration via surface water runoff due to high spate events and/or flooding of the site at high lake levels.

These studies could provide information for completing the human health assessment and in selection of an appropriate remedial alternative. One ideal time for collection of samples to represent near 'worst case' flooding of the site by Lake Champlain may be presently occurring, April through early May, 19.93. Lake Champlain water levels have exceeded record lake levels and thus maximize the potential for off-site contaminant transport.

The study design should include at least seasonal sampling with three sampling locations in the (inundated) wetlands, four locations in the canal (including the turning basin) and at least 3 locations in the Lake (with one location at the mouth of the canal). Three of the sampling events should occur during flooding (rising Lake levels), three events during maximum lake levels, and at least three sampling events during receding waters (lake levels dropping), At each station, whole water samples should be collected with a discrete depth water sampling apparatus, such as a Kemmerer sampler, as close as possible to the sediment water interface, at mid-depth and near-surface locations. All samples should be analyzed using the lowest practical detection limits for each individual compound (i,e,, 10 ng/1 range for PAHs ),

4, The aerial extent and sediment contamination concentrations should be documented.

Documentation of the extent of contamination in the surface sediments in the bottom of the canal is extremely important for evaluating the remedial alternatives for the potential ecological risk that might be presented at the site. Direct contact of the invertebrates and benthic feeding fish and wildlife that utilize the canal with'sediments (and pore water) dictate the amount of exposure present. If exposure can be minimized for the invertebrates in the sediments, then other organisms (fish) will also likely be afforded similar levels of protection.

If the areal extent is limited, the risk may be potentially remediated by less intrusive methods such as habitat enhancement, i.e., placing suitable substrate on the existing bottom. If the areas where free product is present is limited, these areas may be remediated by treating these areas through free product recovery.

Sediment samples should be collected from the surface layer of the sediments using an Ekman dredge or another similar sampling device. These samples should be obtained throughout the canal and should be analyzed for both chemicals of concern, total organic carbon, and physical parameters, such as grain size. The experimental design of the study should characterize the areal extent and contamination in the upper canal sediments. The study objective would be to map the distribution of contamination on the canal bottom and to quantify concentration with high precision. 5. As part of any future remediation plan, a monitoring program which measures off-site migration of contaminants and the quantification of exposure on-site will be required \inder Superfiind.

Although the final monitoring program will depend upon the remedial design plan implemented, several studies which may be beneficial regardless of design alternative are summarized as follows.

Air emissions should be monitored during the remediation and routinely throughout the monitoring program. It is anticipated that methods and detection levels presented above would be at an acceptable level for measuring concentrations near State toxic standards.

Water quality studies to monitor the water being transported from the site should be conducted. As part of these studies the use of benthic invertebrates to monitor low level contaminant migration should be considered. Many invertebrate species can bioaccumulate PAHS and other contaminants in their tissues even when these concentrations in water are low. The use of invertebrates for contaminant monitoring has been successful in other studies on Lake Champlain and the Great Lakes and for monitoring point source discharges. 4,0 SUMMARY

We recognize that the Superfund's objective is the remediation of documented risk when practical. We question the process by which the eventual remediation is accomplished. Although there will likely be studies conducted during the design phase to address data gaps after the Record of Decision (ROD) has been issued, it does not seem logical that a remediation plan be adopted (in the ROD) as part of the legal administrative record before all of these critical data gaps are addressed. It would appear that remediation of the site would be more efficient and defendable if the data necessary to fully characterize important risk pathways were obtained prior to the issuance of the ROD.

We believe that there are several important data gaps that should be addressed before U.S.EPA's preferred remedial alternative or any remedial plan is implemented. ^These proposed__s.tudies—should-not—be— rconstrued--as;ja~proposal to establish the sit^merely.^as~-a—study-area-/ ^=or~a"s~r,ecommendiiigC!£3-np.r,actioni_alten^ '^hazardous_contaminah.t.s_o.which_should be remedi'at'ed-using-the—least -^»=«' ~intrusive~iPethods .that_wi 1 l_r.educ,e_l.ong;ite_nn_ecal£gical^_rijk_jjltho.ut (;-~increasing~'volujntafy_and/or_linvolun However, without the completion of the baseline human health risk assessment, characterization of the canal sediments and surface water, and establishing the connection between site groundwater and its discharge to the lake along the western boundary, any remedial design proposed will likely be more conservative than may be necessary to account for the increased uncertainty.

In summary, the proposed remedial design alternative selected by the EPA may be overly conservative. Although EPA's preferred plan may tend to reduce some ecological risk pathways in the long term, it may also significantly increase involuntary human health risk through the release of contaminants to the air. It seems that this remedial design alternative could be trading off relatively low ecological impacts for involuntary human health risk to the citizens of Vermont. This potential trade-off is unacceptable and suggests that less intrusive remedial alternatives need to be considered for this site. 5.0 REFERENCES

ICF-Clements. 1987. Toxicological Profile for Benzo(a)pyrene. Prepared for the Agency for Toxic Substances and Disease Industry (ATSDR), U.S. Public Health Service in Collaboration with U.S. Environmental Protection Agency (EPA). Oak Ridge National Laboratory.

Eisler, R. 1987. Polycyclic Aromatic Hydrocarbon Hazards to Fish, Wildlife and Invertebrates: A synoptic review. U.S. Fish and Wildlife. Serv. Biol, Rep. 85(1.11) 81 pp.

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