EPA Comments: Portland Harbor Superfund Site Feasibility Study

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 10

Reply to 000

December 182012

Mr Bob Wyatt Chairman Lower Willamette Group co Northwest Natural 220 NW Second A venue Portland Oregon 97209

OREGON OPERATIONS OFFICE 805 SW Broadway Suite 500

Portland Oregon 97205

RE Portland Harbor Superfund Site Administrative Order on Consent for Remedial Investigation and Feasibility Study Docket No CERCLA-10-2001-0240 EPA Comments on the Portland Harbor RIIFS Draft Feasibility Study (March 30 2012)

Dear Mr Wyatt

EPA and its partners have reviewed the Portland Harbor RlFS Draft Feasibility Study (FS) dated March 302012 and submitted to EPA by the Lower Willamette Group (LWG) This-letter provides EPAs initial and general comments on the draft FS report EPAs project partners also contributed to these comments

The draft FS Report is a substantial body of work that provides many useful tools and technical evaluations The technical analysis in the draft FS can with supplemental analysis and revisions be used to support EPAs evaluation of remedial alternatives The draft FS provides a reasonable range of remedial action alternatives for the detailed and comparative evaluation of alternatives The mapping of locations and concentrations in the sediments ofkey contaminants of potential concern (COPCs) that exceed preliminary Remedial Action Levels (RALs) will be useful in providing a preliminary identification of the Sediment Management Areas (SMAs)

At this time however the draft FS is not adequate for its intended purpose and is not approved by EPA The report has many deficiencies and needs substantial revision in order to fully support EPAs evaluation of alternatives and provide an adequate basis for remedial decision making at the Portland Harbor Site A list of some of the key areas of concern identified by EPA and its partners to date is presented below

To move the revision of the FS more quickly EPA will perform an independent evaluation and comparison of the alternatives that were presented in the draft FS Given the extensive nature of our concerns EPA believes the most expeditious way to finalize the FS is for EPA to draft significant portions of the revisions to the draft FS with considerable support from the L WG on technical evaluations cost evaluations middotrevising tables and figures etc EPA intends to work

cooperatively with the L WG in completing the FS and expects that revisions to the FS by both parties will be shared for review and comment as they are developed in order to proceed in an iterative manner

EPA will only be providing detailed comments on the portions of the draft FS that we will require the LWG to revise or perform more analysis General areas of concern on the draft FS are therefore noted in this letter and the attached comments but specific requests to LWG will be provided under separate c_over throughout the revision process In keeping with the shared goal of completing this document in a timely manner we will work with the L WG to develop a process and schedule for revising this document that targets November 2013 as a completion date for the FS

Key areas of concern identified by EPA and its partners include the following

Text Figures and Presentation There are many instances where the text is confusing and key information is not presented in a clear and usable manner For example the scale used in some figures (eg Appendix Fa figures that present the River Mile SWAC vs Area Remediated results for time T=O) makes it difficult to differentiate between the alternatives In other cases the assumptions used in some of the evaluations are not clearly stated in the document There is also too much advocacy in some sections of the report that obscures the straightforward presentation of information Please note that our lack of detailed comments on the text and figures in this initial comment set should not be construed to imply that we are in agreement with the text EPA expects to work with LWG to revise figures and text in the document to correct these problems

Fate and Transport Modeling and MNR EPA has identified many concerns related to the MNR modeling and conclusions and has provided more detail in the attached comments The US Army Corps Engineer Research and Development Lab recently performed independent model runs linking deposition to hydrodynamics Based on the Corps modeling runs it appears there is sufficient uncertainty in the LWG model results to conclude that the long-term projections provided in the draft FS do not accurately predict depositional rates for many areas in the lower Willamette River that are of concern for this remedial action

Since we have the Corps model results EPA at this point intends to use the empirical and both the Corps and AnchorQEA modeled results to support the evaluation of alternatives middot rather than request revision of the Anchor QEA model runs to address specific concerns

Principal Threat Waste and Hot Spots EPA does not agree with the results of the analysis that L WG has provided which ultimately a yo ids designating any sediment at the site as Principal Threat Waste (PTW) as defined by EPA guidance or Hot Spots as defined by the State of Oregon a The overall intent of EPAs guidance and Oregons regulations is to ensure that there is a preference

a ORS 465315(2)(b)(A) and OAR 340-122-0115(32)(b)

for the treatment or removal of those materials with high concentrations or that are highly mobile or that may not be reliably contained

Another omission in the FS is the lack of any meaningful analysis ofPTW in accordance with the NCP and CERCLA guidance EPA guidance defines principal threat waste as a source material that is highly toxic or highly mobile that generally cannot bemiddot reliably contained or would present a significant risk to human health or the environment should exposure occur such as drummed waste or pools of non-aqueous phase liquids (EPA 1991) Based on this definition the Portland Harbor FS should clearly acknowledge that the documented presence of non-aqueous phase liquids in sediments off shore of the Gasco and Arkema sites indicates that PTW is present at the Portland Harbor Site Additional analysis of PTW must be conducted as part of the revised FS

In addition while some of the LWGs arguments in the draft FS regarding Hot Spot designation have merit DEQ is still concerned that 1) an attempt to identify high concentration Hot Spots in Portland Harbor has not been done 2) high concentration Hot Spots may exist in Portland Harbor and 3) some of those Hot Spots may not be covered by active remediation included in current remedial alternatives

The FS must identify any additional high concentration Hot Spots in Portland Harbor in accordance with Oregon regulations While the LWGs FS strategy may approach the intent of the Hot Spot rules it does not answer the question of whether high concentration Hot Spots as defined in Oregon regulations exist If high concentration Hot Spots actually exist outside of areas identified as PTW or currently designated for active remediation then the very important state ARAR for preference for treatment will not be addressed As has been stated in the pastDEQ is willing to work with the LWG to develop a reasonable approach for identifying high concentration Hot Spots and then participate in decisions of how to address potential Hot Spots in the FS

Site-Wide vs Relevant Exposure Areas The draft FS and LWGs public presentations on the draft FS clearly emphasize a site-wide approach with respect to surface-weighted average concentration calculations (SWACs) and phenomena such as deposition and receptor exposures Contaminant sources and types are not homogeneous site-wide and most exposures are not site-wide yet the draft FS frequently focuses analyses and presents conclusions at the site-wide or river mile scale For example the site is depositional is frequently repeated despite the fact that many areas of the site are subject to erosion due to natural (eg high flow events) or anthropogenic (eg prop wash) causes That assertion is not relevant or helpful to determining remedial response actions for individual areas where remedial actions will occur Combining exposure areas (ie site-wide segment-wide or to the river mile) is not environmentally or biologically relevant for many receptor exposure scenarios and effectively dilutes the calculated risks and appearance of unacceptable exposures As stated in previous EPA comments the draft FS analyses must focus on contaminated areas at exposure scales consistent with contaminant distribution in addition to site-wide analysis

EPA disagrees with the LWGs assertion in the alternatives analysis that all alternatives (B-F) meet seven of the NCP nine criteria because the agency asserts that site-wide surface-area weighted average concentrations (SWACs) are not appropriate at this site The use of site-wide SW ACs to achieve remedial goals allows substantial spatial areas with higher and potentially problematic levels of contamination to be masked by areas with lower contamination EPA also disagrees with the LWG NCP criteria analysis overreliance on the MNR evaluations for the reasons discussed above and in the attachment

Dredging EPA has significant issues with the evaluation of dredging-based remedies in the draft FS which underestimates the overall effectiveness of such remedies The evaluation of dredging in the draft FS overemphasizes the short-term impacts of dredging-based remedies underestimates the effectiveness and implementability of sheet pile enclosures and overestimates the length of time needed to complete dredging work for many alternatives The long- and short-term effectiveness of dredging must be evaluated using more realistic assumptions about effectiveness of dredging controls and duration based on the experience at other sites around the country

The draft FS assumption that the extensive dredging inherent in the more aggressive remedies such as Alternative F will take up to 28 years to implement is not well supported by existing information and is overly biased The draft FS schedules are driven by assumptions of equipment availability construction rates and seasonal dredging restrictions which results in limiting the amount of work that can be completed in a calendar year However no attempt was made to consider higher estimates of production rates and longer in-water work windows if engineered controls were applied to separate river receptors from dredging areas Such other dredging controls and middot scenarios must also be evaluated to provide information that could be the basis for seeking federal and state agency support for adjusting fish windows so that remediation could proceed more rapidly to achieve the benefit of removing from the river

Appendix E - Sensitivity Analysis (Ecological and Human Health) EPA rejects the uncertainty analysis in Appendix E EPA has significant policy and technical concerns with the assessment and the fact that the conclusions drawn from the assessment also permeate the text and presentations in many sections of the main report

The text in Appendix E is written to give the erroneous impression that the sensitivity analysis was either required by EPA guidance or was conducted consistent with EPA guidance However the sensitivity analysis in the draft FS is not consistent with EPA guidance A detailed discussion of uncertainties associated with the exposure values used in the BHHRA is already presented in that report including a quantitative estimate of the magnitude of the uncertainties on the overall risk estimates Further inconsistent with the guidance cited in this appendix no work plan was submitted to EPA for review and concurrence and the probabilistic reanalysis of the exposure assessment presented here ignores the recommendation in Section 52 of RAGS Volume III that if only point

estimates were used in the risk assessment probabilistic methods should not be used for PRG development

Another example of the technical deficiencies with the analysis is the LWG has mischaracterizedmisinterpreted the fish consumption rates as used in the BHHRA of 175 glday and 142 glday as upper percentiles (90th and 99th) for consumers of fish This mischaracterization of consumption rates as upper percentiles for fish consumersinstead of median values has profound implications in the analysis In a probabilistic evaluation about one half of the values are expected to be above the 50th percentile and one half of the values below the 50th percentile Additional detail on this concern is provided in the attached comment table

Scoring and weighting of factors for comparative analysis of alternatives EPA disagrees with the scoring and weighting of criteria in the comparative analysis of alternatives as applied in the draft FS For example the comparative evaluation of alternatives overemphasizes duration of cleanup in the evaluation of short term impacts associated with active remediation while underemphasizing the effects of delaying substantial risk reduction associated with long MNR timeframes The evaluation did not adequately consider methods to reduce short-term impacts such as alternate sequencing and engineering controls

EPA will be evaluating various combinations of technologies in addition to those packaged as alternatives B through G in the draft FS For example alternatives C though Fall include various combinations ofCDFs for disposal Alternatives with similar RALs should have been evaluated assuming off-site disposal of all dredged sediment to provide a basis for comparison with the combinations presented in the draft FS Construction sequencing options also should have been developed that prioritize risk reduction consider greater flexibility in estimated work windows and greater efficiencies in production The rationale behind the sequencing of construction presented for many of the alternatives is not clearly presented particularly for removal options While the draft FS provides many of the tools necessary to perform these evaluations additional technical evaluation will be necessary to conduct the comparati_ve analysis of alternatives

In summary while the draft FS provides useful information and tools to assist EPA in the selection of a remedy at the Portland Harbor site key elements needed for EPA to select a remedy are inadequate as described or in more detail in the attached comment list As a result EPA has determined that major modifications to the document are needed before EPA can select a remedy for this site EPA is continuing to review the information presented in the draft document and conducting an independent evaluation of cleanup alternatives and supporting information needed for making cleanup decisions for the Portland Harbor Site EPA will be considering more realistic assumptions about overall effectiveness of dredging the length of time that in-water remediation will take the uncertainties of MNR effectiveness and the spatial scale of the assessment The revised FS will also need to reflect the conclusions and results of the final BHHRA and BERA EPA will be providing additional detailed comments and direction concurrent with its independent analyses such that L WG can provide additional information and responses to EPA concerns during this period of review and revision

We look forward to working with the LWG on revisions to the document that will be needed to support EPAs proposed cleanup plan for the Portland Harbor Site We would be happy to meet with the LWGs project managers in the near future to discuss EPAs process for completing the

draft FS including next steps apd our vision for completing the work If you have any questions please contact Chip Humphrey at (503) 326-2678 or Kristine Koch at (206) 553-6705 For legal questions please contact Lori Cora at (206) 553 1115

Chip Humphrey Remedial Project Manager

Kristine Koch Remedial Project Manager

Enclosure

cc Mr Jim Anderson ODEQ

Mr Rob Neely NOAA

Mr Ted Buerger US Fish and Wildlife Service

Mr Brian Cunninghame Confederated Tribes of the Warm Springs Reservation of Oregon

Ms Rose Longoria Confederated Tribes and Bands of the Y akama Nation

Mr MichaelKarnosh Confederated Tribes of the Grand Ronde Community of Oregon

Mr Tom Downey Confederated Tribes of the Siletz Indians

Mr Audie Huber Confederated Tribes of the Umatilla Indian Reservation

Ms Erin Madden Nez Perce Tribe

Mr Todd Hudson Oregon Health Authority

Mr Rick Keppler Oregon Fish and Wildlife

FS Review Team Comments on Portland Harbor Draft Feasibility Study (March 2012)

No Comment13 Subject

Reference Comment

1 Benthic13 Risk13 Evaluation

General The13 evaluation13 of13 benthic13 risk13 will13 need13 to13 be13 updated13 to13 reflect13 any13 changes13 from13 completion13 of13 the13 BERA13 13 The13 outstanding13 issues13 must13 be13 resolved13 in13 order13 to13 evaluate13 the13 protectiveness13 and13 long13 term13 effectiveness13 and13 permanence13 of13 the13 various13 remedial13 alternatives13

Although13 the13 RALs13 evaluated13 in13 the13 FS13 will13 address13 the13 majority13 of13 contamination13 presenting13 risk13 to13 human13 health13 and13 the13 environment13 the13 exception13 to13 this13 is13 the13 benthic13 risk13 areas13 13 EPA13 will13 be13 providing13 direction13 on13 a13 multiple13 lines13 of13 evidence13 approach13 to13 identifying13 benthic13 risk13 areas13 13 The13 discussions13 figures13 and13 evaluations13 presented13 in13 the13 FS13 related13 to13 benthic13 risk13 will13 need13 to13 be13 revised13 based13 on13 the13 guidance13 to13 be13 provided13 13

In13 addition13 the13 evaluation13 of13 protectiveness13 and13 long13 term13 effectiveness13 and13 permanence13 includes13 the13 use13 of13 long13 term13 modeling13 results13 averaged13 over13 a13 frac1213 mile13 area13 13 A13 frac1213 mile13 area13 is13 too13 large13 to13 evaluate13 effects13 on13 the13 benthic13 community13 13 Benthic-shy‐associated13 risks13 should13 be13 evaluated13 on13 a13 point13 by13 point13 basis

2 Site-shy‐wide13 evaluation13 vs13 relevant13 exposure13 areas

General The13 FS13 includes13 too13 much13 focus13 on13 site-shy‐wide13 phenomena13 such13 as13 deposition13 and13 receptor13 exposures13 13 Contaminant13 sources13 and13 types13 are13 not13 homogeneous13 site13 wide13 and13

frequently13 repeated13 13 That13 assertion13 is13 not13 relevant13 or13 helpful13 to13 analyze13 the13 feasibility13 of13 response13 actions13 taken13 on13 specific13 areas13 the13 scale13 where13 managing13 cleanup13 actions13 will13 occur13 13 The13 draft13 FS13 aggregates13 exposure13 areas13 (ie13 site13 wide13 segment-shy‐wide13 or13 to13 the13 river13 mile)13 which13 is13 not13 environmentally13 or13 biologically13 relevant13 and13 effectively13 dilutes13 risk13 and13 unacceptable13 exposures13 13 The13 FS13 analyses13 should13 focus13 on13 contaminated13 areas13 and13 exposure13 areas13 where13 exposures13 require13 management13 not13 site13 wide

that13 all13 alternatives13 (B-shy‐F)13 meet13 the13 NCP13 criteria13 because13 site-shy‐wide13 SWACs13 are13 not13 appropriate13 at13 this13 site13 13 The13 use13 of13 site-shy‐wide13 SWACs13 allows13 substantial13 areas13 with13 higher13 and13 potentially13 problematic13 levels13 of13 contamination13 to13 be13 masked13 by13 areas13 with13 lower13 contamination13 yet13 the13 exposure13 would13 remain

3 Oregon13 Hot13 Spots13 and13 PTW

Section13 55113 -shy‐13 Potential13 Oregon13 Hot13 Spots13 Table13 55-shy‐113

ARARs13 -shy‐13 Hot13 Spots13 of13 contamination13 -shy‐13 Identification13 of13 Hot13 Spots13 as13 defined13 by13 Oregons13 cleanup13 rules13 is13 an13 important13 ARAR13 in13 the13 Portland13 Harbor13 project13 for13 DEQ13 13 Hot13 Spots13 are13 addressed13 in13 several13 sections13 of13 Oregon13 Hazardous13 Substance13 Remedial13 Action13 Rules13 (OAR13 340-shy‐122)13 13 The13 basic13 intent13 of13 Hot13 Spot13 rules13 is13 to13 require13 a13

Hot13 Spots13 in13 Portland13 Harbor13 has13 not13 been13 done13 2)13 high13 concentration13 Hot13 Spots13 may13 exist13 in13 Portland13 Harbor13 and13 3)13 some13 of13 those13 Hot13 Spots13 may13 not13 be13 covered13 by13 active13 remediation13 included13 in13 current13 remedial13 alternatives

question13 of13 whether13 high13 concentration13 Hot13 Spots13 exist13 13 If13 high13 concentration13 Hot13 Spots13 actually13 exist13 outside13 of13 areas13 currently13 designated13 for13 active13 remediation13 then13 the13 very13 important13 state13 ARAR13 for13 preference13 for13 treatment13 will13 not13 be13 addressed13 13 13 As13 has13 been13 stated13 in13 the13 past13 DEQ13 is13 willing13 to13 work13 with13 the13 LWG13 to13 develop13 a13 reasonable13 approach13 for13 identifying13 high13 concentration13 Hot13 Spots13 and13 then13 participate13 in13 decisions13 of13 how13 to13 address13 potential13 Hot13 Spots13 in13 the13 FS

Section13 55213 -shy‐13 Principal13 Threat13 Waste13 (PTW)13 Areas

Another13 omission13 in13 the13 FS13 is13 the13 lack13 of13 any13 meaningful13 analysis13 of13 principal13 threat13 waste13 in13 accordance13 with13 the13 NCP13 and13 CERCLA13 guidance13 EPA13 guidance13 defines13 principal13 threat13 waste13 as13 a13 source13 material13 that13 is13 highly13 toxic13 or13 highly13 mobile13 that13 generally13 cannot13 be13 reliably13 contained13 or13 would13 present13 a13 significant13 risk13 to13 human13 health13 or13 the13 environment13 should13 exposure13 occur13 such13 as13 drummed13 waste13 or13 pools13 of13 non-shy‐aqueous13 phase13 liquids13 (EPA13 1991)13 13 Based13 on13 this13 definition13 the13 Portland13 Harbor13 FS13 should13 clearly13 acknowledge13 that13 the13 documented13 presence13 of13 non-shy‐aqueous13 phase13 liquids13 in13 sediments13 off13 shore13 of13 the13 Gasco13 and13 Arkema13 sites13 indicates13 that13 Principle13 Threat13 Waste13 (PTW)13 is13 present13 at13 the13 Portland13 Harbor13 Site13 13 Additional13 analysis13 of13 PTW13 will13 be13 conducted13 as13 part13 of13 the13 revised13 FS13

FS Review Team Comments on Portland Harbor Draft Feasibility Study (March 2012)No Comment13

SubjectReference Comment

5 ESA13 Consultation13 and13 Mitigation

General LWG13 should13 note13 that13 mitigation13 under13 the13 Clean13 Water13 Act13 and13 ESA13 are13 not13 one13 and13 the13 same13 13 Furthermore13 for13 ESA13 mitigation13 NOAA13 will13 not13 be13 considering13 mitigation13 at13 the13 scale13 of13 the13 4th13 field13 Hydraulic13 Unit13 Code13 13 Upper13 Willamette13 River13 (UWR)13 ESA-shy‐listed13 salmonid13 stocks13 or13 Lower13 Columbia13 River13 (LCR)13 ESA-shy‐listed13 salmonid13 stocks13 (or13 the13 specific13 impacted13 life13 stages13 of13 these13 stocks)13 could13 be13 omitted13 13 13 Because13 potential13 response13 actions13 in13 the13 LWR13 may13 adversely13 affect13 critical13 habitat13 for13 both13 UWR13 and13 LCR13 stocks13 all13 such13 species13 and13 associated13 life13 stages13 (of13 the13 affected13 evolutionarily13 significant13 unitsdistinct13 population13 segments)13 must13 be13 taken13 into13 account13 when13 selecting13 mitigation13 sites13 intended13 as13 a13 measure13 for13 mitigating13 affects13 on13 critical13 habitat13 13 In13 addition13 the13 location13 where13 the13 critical13 habitat13 degradation13 occurs13 will13 be13 heavily13 considered13 when13 deciding13 on13 the13 appropriate13 location13 for13 mitigation13 13 Mitigation13 for13 adverse13 affects13 on13 critical13 habitat13 within13 the13 Portland13 Harbor13 Superfund13 Site13 will13 be13 a13 priority13 for13 ESA13 purposes13

NOAA13 will13 carefully13 review13 each13 individual13 proposed13 clean-shy‐up13 action13 in13 the13 harbor13 (and13 not13 the13 Portland13 Harbor13 remedy13 as13 a13 whole)13 during13 remedial13 design13 to13 ensure13

but13 rather13 will13 defer13 to13 post-shy‐ROD13 supplemental13 consultations13 on13 specific13 remedial13 actions13

6 RAOs13 RGs13 and13 RALs

Generalrelatively13 early13 in13 the13 FS13 because13 according13 to13 the13 natural13 recovery13 assumptions13 in13 their13 analysis13 it13 did13 not13 offer13 any13 benefit13 relative13 to13 Alternative13 F13 13 13 Based13 on13 the13 concerns13 identified13 with13 the13 fate13 and13 transport13 model13 and13 MNR13 assumptions13 a13 more13 robust13 analysis13 of13 Alternative13 G13 needs13 to13 be13 performed

General Noncancer13 risks13 -shy‐13 Noncancer13 risks13 are13 not13 discussed13 with13 the13 same13 depth13 and13 frequency13 as13 cancer13 risks13 The13 most13 important13 risk13 at13 the13 site13 is13 noncancer13 effects13 from13 PCBs13 on13 infants13 (For13 example13 Executive13 Summary13 Conclusion13 ES-shy‐3113 second13 to13 last13 bullet)13

Section13 2313 -shy‐13 Biological13 and13 Habitat13 Description13 page13 2-shy‐12

risks13 to13 ecological13 receptors13 (eg13 the13 benthic13 invertebrate13 community13 and13 fish13 and13 wildlife13 populations)13 as13 detailed13 in13 the13 draft13 final13 BERA13 (Windward13 2011)13 The13 primary13 ecological13 risks13 are13 from13 bioaccumulation13 of13 PCBs13 and13 other13 persistent13 contaminants13 by13 wildlife13 and13 their13 prey13 which13 occur13 in13 addition13 to13 the13 direct13 risks13 to13

There13 are13 other13 risk13 areas13 that13 occur13 over13 a13 more13 localized13 scale13 as13 indicated13 by13 comments13 on13 the13 BERA13 that13 need13 to13 be13 brought13 into13 the13 FS13 13 Due13 to13 the13 use13 of13 a13 large13 spatial13 exposure13 scale13 defined13 by13 a13 study13 area13 to13 most13 receptors13 and13 media13 and13 the13 large13 exposure13 area13 used13 in13 the13 risk13 assessment13 many13 localized13 areas13 exhibiting13 unacceptable13 risk13 were13 dropped13 (eg13 lines13 that13 represent13 HQgt1)13 13 Examplesa13 Surface13 water13 RAO13 713 (Section13 3-shy‐14)13 13 Surface13 water13 lines13 of13 evidence13 were13 inappropriately13 dropped13 in13 BERA13 (see13 EPA13 BERA13 comments)13 and13 need13 to13 be13 brought13 back13 inb13 Tissue13 Residue13 13 Localized13 areas13 with13 HQgt113 should13 have13 been13 identified13 in13 the13 BERA13 and13 should13 be13 added13 to13 the13 FSIdentify13 localized13 areas13 that13 potentially13 exhibit13 unacceptable13 risk13 that13 may13 be13 dropped13 by13 draft13 FS13 evaluation13 and13 provide13 clear13 evaluation13 of13 risk13 in13 these13 areas

Section13 32113 -shy‐13 RAO13 Considerations13 RAO13 313 page13 3-shy‐11

Carcinogenic13 PAHs13 exceed13 the13 10-shy‐613 risk13 level13 based13 on13 a13 drinking13 water13 exposure13 scenario13 13 In13 addition13 although13 depth13 integrated13 surface13 water13 samples13 do13 not13 exceed13 MCLs13 some13 near13 bottom13 samples13 do13 exceed13 MCLs13 for13 chemicals13 such13 as13 vinyl13 chloride13 and13 benzo(a)pyrene13 13 The13 draft13 FS13 states13 that13 RAO13 313 is13 already13 being13 achieved13 13 This13 is13 not13 necessarily13 accurate13 13 It13 would13 be13 better13 for13 the13 FS13 to13 acknowledge13 there13 is13 data13 indicating13 that13 there13 are13 sources13 from13 uplands13 groundwater13 or13 sediments13 that13 could13 have13 potential13 impact13 on13 the13 drinking13 water13 beneficial13 use13 of13 the13 Willamette13 River13 and13 remedial13 actions13 and13 upland13 source13 control13 efforts13 will13 need13 to13 take13 into13 account13 the13 need13 to13 protect13 the13 drinking13 water13 exposure13 pathway

Section13 3513 -shy‐13 PRGs13 and13 Proposed13 RGs13 page13 3-shy‐25

the13 draft13 FS13 addresses13 all13 contaminants13 posing13 potentially13 unacceptable13 risk13 as13 identified13 in13 the13 baseline13 risk13 assessments13 as13 well13 as13 contaminants13 yielded13 from13 the13 EPA-shy‐required13 additional13 water13 screening13 steps13 described13 in13 Section13 31contaminants13 posing13 potentially13 unacceptable13 risk13 were13 identified13 in13 the13 BERA13 and13 therefore13 are13 not13 contained13 in13 the13 FS

Section13 35113 -shy‐13 PRGs13 page13 3-shy‐26

will13 likely13 need13 to13 be13 re-shy‐evaluated13 13 13 These13 are13 some13 preliminary13 concerns

i13 Problem13 formulation13 states13 BSAFs13 should13 have13 been13 developed13 for13 chemicals13 included13 in13 the13 food13 web13 model13 (eg13 PCBs13 dioxins13 and13 DDX13 compounds)13 13 This13 analysis13 should13 have13 been13 included13 here13 especially13 since13 some13 areas13 of13 concern13 represent13 localized13 areas13 (non-shy‐site13 wide)

ii13 PRGs13 for13 sculpin13 should13 be13 0113 mile13 of13 linear13 shoreline13 and13 not13 a13 centroid13 13 This13 approach13 places13 too13 much13 emphasis13 on13 deeper13 water13 exposure13 that13 has13 not13 shown13 to13 correlate13 with13 sculpin13 habitat

iii13 PRGs13 were13 developed13 using13 data13 from13 both13 sides13 of13 the13 river13 for13 smallmouth13 bass13 in13 113 mile13 increments13 13 This13 should13 be13 revised13 to13 include13 1-shy‐mile13 segments13 restricted13 to13 one13 side13 of13 the13 river13 or13 the13 other13 13 This13 approach13 dilutes13 exposure13 that13 occurs13 primarily13 from13 one13 side13 of13 the13 river

database13 13 The13 BERA13 dataset13 would13 presumably13 be13 much13 more13 limited13 to13 co-shy‐located13 tissue13 and13 bioassay13 stations13

Section13 4213 -shy‐13 RAL13 Development13 Methods13 page13 4-shy‐5

The13 RAL13 evaluation13 methods13 focus13 on13 incremental13 SWAC13 reduction13 13 The13 analysis13 should13 be13 focused13 on13 risk13 reduction13 rather13 that13 SWAC13 reduction13 13 Risk13 reduction13 should13 be13 considered13 over13 a13 variety13 of13 exposure13 scales13 consistent13 with13 the13 risk13 assessment13 assumptions13 13 The13 information13 in13 Table13 43-shy‐113 illustrates13 this13 point13 since13 the13 SWACs13 are13 averaged13 across13 the13 river13 when13 much13 of13 the13 exposure13 may13 be13 taking13 place13 in13 the13 near13 shore13 areas13 13 It13 may13 also13 be13 that13 much13 of13 the13 MNR13 is13 taking13 place13 in13 the13 near13 shore13 areas13 which13 tend13 to13 be13 depositional13 and13 dominated13 by13 fine-shy‐grained13 sediment13 rather13 than13 the13 higher13 energy13 navigation13 channel13 which13 experiences13 prop13 wash13 and13 sand13 waves13 and13 is13 dominated13 by13 coarse-shy‐grained13 sediments13

Section13 5713 -shy‐13 Analysis13 of13 TZW13 Impacts13 in13 and13 near13 SMAs13 page13 5-shy‐30

All13 chemicals13 in13 all13 media13 with13 HQgt113 should13 be13 considered13 in13 the13 FS

15 SMAs Section13 5313 -shy‐13 SMA13 Mapping13 Methods

There13 are13 some13 concerns13 about13 assumptions13 made13 in13 the13 interpolation13 of13 the13 SMAs13 particularly13 in13 areas13 with13 low13 data13 density13 (see13 Section13 533)13 13 For13 each13 contaminant13 a13 buffer13 distance13 was13 developed13 from13 the13 average13 distance13 between13 sample13 points13 the13 buffer13 was13 used13 to13 mask13 out13 any13 areas13 with13 interpolated13 concentrations13 above13 RALs13 that13 are13 beyond13 the13 buffer13 distance13 from13 any13 point13 This13 may13 result13 in13 inaccurate13 acreages13 and13 estimates13 of13 volumes13 particularly13 in13 river13 miles13 (RMs)13 6-shy‐813 13 13

Additionally13 it13 appears13 that13 the13 maps13 do13 not13 include13 all13 areas13 that13 exceed13 the13 RALs13 The13 FS13 does13 not13 include13 areas13 where13 the13 average13 concentrations13 do13 not13 pose13 potentially13 unacceptable13 risks13 from13 benzo(a)pyrene13 even13 if13 those13 areas13 do13 exceed13 the13 RALs13 (such13 as13 Swan13 Island13 Lagoon13 see13 p13 5-shy‐4)13 The13 FS13 also13 does13 not13 include13 areas13 with13 benzo(a)pyrene13 and13 polychlorinated13 biphenyl13 (PCB)13 concentrations13 greater13 than13 the13 RALs13 outside13 of13 the13 areas13 of13 potential13 concern13 (AOPC)13 boundaries13 (see13 p13 5-shy‐8)13 There13 is13 no13 explanation13 of13 how13 many13 areas13 were13 removed13 where13 they13 were13 or13 what13 the13 nature13 of13 exceedances13 may13 have13 been13 The13 areas13 outside13 AOPC13 boundaries13 with13 RAL13 exceedances13 should13 be13 included13 or13 a13 clear13 explanation13 of13 why13 specific13 areas13 were13 not13 included13 should13 be13 provided

16 SMAs Section13 5613 -shy‐13 Evaluation13 of13 Buried13 Contamination

The13 potential13 for13 exposure13 of13 buried13 contamination13 from13 dredging13 or13 other13 erosive13 forces13 was13 only13 evaluated13 in13 designated13 future13 dredge13 areas13 (see13 Section13 564)13 and13 the13 navigation13 channel13 (see13 Section13 565)13 There13 is13 no13 analysis13 presented13 of13 all13 areas13 where13 buried13 contamination13 exists13 and13 information13 upon13 which13 one13 can13 judge13 where13 there13 is13 a13 significant13 potential13 risk13 of13 exposure13 of13 subsurface13 contamination13 13 The13 FS13 should13 have13 developed13 a13 list13 of13 factors13 or13 criteria13 by13 which13 all13 subsurface13 contamination13 would13 be13 evaluated13 for13 the13 need13 for13 active13 cleanup13 or13 institutional13 controls13 to13 avoid13 exposure13 in13 the13 future

17 SMAs Section13 56413 -shy‐13 Potential13 Future13 Maintenance13 Dredge13 Areas13 Outside13 of13 Navigation13 Channel13 page13 5-shy‐26

The13 draft13 FS13 states13 13 Any13 potential13 FMD13 areas13 with13 an13 exceedance13 of13 more13 than13 two13 times13 the13 RAL13 in13 those13 horizons13 was13 added13 to13 its13 nearest13 surface13 SMA13 13 Although13 EPA13 acknowledges13 the13 uncertainty13 the13 factor13 of13 213 times13 seems13 arbitrary13 13 It13 is13 more13 defensible13 to13 use13 the13 RAL13 directly13 13 Please13 revise13 to13 compare13 to13 the13 RAL13 instead13 of13 two13 times13 the13 RAL

FMD13 areas13 that13 are13 within13 SMAs13 should13 analyze13 a13 preference13 for13 removal13 similar13 to13 that13 applied13 to13 the13 navigation13 channel13 areas13 to13 address13 areas13 with13 the13 likelihood13 of13 potential13 exposure13 to13 eliminate13 risk13 of13 such13 threats13 rather13 than13 rely13 on13 subsequent13 40413 permit13 actions13 13

18 Fate13 and13 Transport13 ModelMNR

General Many13 concerns13 have13 been13 identified13 related13 to13 the13 MNR13 modeling13 and13 conclusions13 including13 those13 described13 below13 13 In13 the13 broadest13 terms13 EPA13 accepts13 the13 general13 precepts13 but13 not13 the13 outcome13 of13 the13 MNR13 modeling13 effort13 results13 and13 conclusions13 13 Based13 on13 running13 independent13 models13 linking13 deposition13 to13 hydrodynamics13 EPA13 believes13 that13 the13 LWG13 models13 results13 are13 sufficiently13 uncertain13 that13 out-shy‐year13 projections13 are13 not13 considered13 reliable13 13

Due13 to13 the13 uncertainty13 in13 long-shy‐term13 estimates13 and13 small13 scale13 variability13 in13 the13 empirical13 MNR13 evaluation13 the13 FS13 should13 rely13 primarily13 on13 the13 remedial13 outcomes13 immediately13 following13 construction13 13 Rather13 than13 request13 revision13 of13 the13 model13 runs13 to13 address13 specific13 concerns13 in13 conjunction13 with13 EPAs13 independent13 model13 runs13 EPA13 intends13 to13 use13 the13 empirical13 and13 modeled13 results13 to13 support13 the13 evaluation13 of13 alternatives

The13 draft13 FS13 appears13 to13 rely13 on13 MNR13 for13 the13 majority13 of13 cleanup13 13 The13 goal13 should13 be13 that13 SWACs13 over13 an13 appropriate13 exposure13 area13 achieve13 RGs13 (or13 background)13 at13 close13 to13 T=013 rather13 than13 at13 T=3013 or13 4013 years13 13 The13 evaluation13 of13 alternatives13 should13 rely13 on13 active13 remediation13 for13 the13 majority13 of13 cleanup13 and13 use13 MNR13 to13 continue13 to13 improve13 conditions13 with13 monitoring13 to13 ensure13 that13 long13 term13 objectives13 are13 met

General Modeling13 in13 the13 FS13 indicates13 rapid13 reductions13 in13 contaminant13 concentrations13 in13 sediment13 via13 natural13 recovery13 (MNR)13 13 The13 primary13 mechanism13 driving13 the13 modeled13 reductions13 in13 contaminant13 concentrations13 is13 burial13 a13 process13 by13 which13 cleaner13 sediment13 deposits13 on13 contaminated13 sediment13 diluting13 and13 burying13 contaminated13 sediment13 over13 time13 13 EPA13 determined13 that13 the13 model13 used13 to13 predict13 deposition13 of13 clean13 sediments13 does13 not13 account13 for13 the13 impact13 of13 deposited13 sediments13 on13 water13 flow13 and13 erosion13 13 Put13 simply13 during13 the13 30-shy‐year13 model13 simulation13 sediment13 continues13 to13 accumulate13 but13 that13 change13 in13 water13 depth13 is13 never13 seen13 by13 the13 model13 13 In13 effect13 the13 model13 can13 predict13 the13 deposition13 of13 several13 feet13 of13 clean13 sediment13 (even13 to13 levels13 that13 would13 breach13 the13 water13 surface)13 with13 no13 associated13 change13 in13 the13 water13 velocity13 in13 that13 area13 13 This13 aspect13 of13 the13 model13 does13 not13 reflect13 fundamental13 principles13 dictating13 sediment13 deposition13 over13 time13 when13 water13 flow13 is13 constricted13 the13 flow13 velocity13 increases13 along13 with13 erosive13 forces13 and13 transport13 of13 sediment13 13 This13 shortcoming13 in13 the13 model13 framework13 suggests13 that13 deposition13 (and13 hence13 MNR13 which13 occurs13 via13 deposition)13 is13 overpredicted13 at13 least13 in13 certain13 portions13 of13 the13 river13 13 Omission13 of13 a13 fundamental13 principle13 of13 hydrodynamics13 and13 sediment13 transport13 in13 the13 modeling13 framework13 in13 a13 water13 body13 where13 predicted13 reductions13 in13 depth13 due13 to13 deposition13 are13 significant13 in13 some13 areas13 greatly13 reduces13 the13 confidence13 in13 MNR13 predictions13 13

EPA13 compared13 the13 model13 framework13 used13 in13 the13 FS13 (a13 version13 of13 EFDC13 that13 doesnt13 link13 [or13 feedback]13 sediment13 accumulation13 to13 hydrodynamics)13 to13 a13 version13 of13 EFDC13 that13 links13 sediment13 accumulation13 and13 bathymetry13 changes13 to13 hydrodynamics13 13 The13 purpose13 was13 to13 understand13 if13 the13 deposition13 over13 time13 predicted13 by13 these13 frameworks13 varied13 and13 if13 so13 how13 13 All13 other13 modeling13 aspects13 were13 kept13 the13 same13 as13 the13 original13 FS13 (eg13 the13 model13 grid13 initial13 conditions13 and13 sediment13 and13 hydrodynamic13 parameters)13 13 The13 changes13 in13 bed13 elevation13 (ie13 the13 amount13 of13 deposition13 or13 erosion)13 predicted13 by13 each13 model13 over13 the13 3013 year13 run13 time13 were13 compared13 13 Results13 indicate13 that13 the13 FS13 model13 showed13 greater13 deposition13 than13 the13 linked13 model13 (defined13 as13 greater13 than13 0513 ft)13 in13 5513 of13 the13 cells13 with13 results13 ranging13 from13 613 inches13 to13 greater13 than13 2013 feet13 more13 deposition13 13 The13 models13 show13 similar13 deposition13 (+-shy‐13 0513 ft)13 in13 4013 of13 the13 cells13 In13 513 of13 the13 cells13 the13 FS13 model13 showed13 less13 deposition13 (or13 greater13 scour)13 than13 the13 linked13 version13 of13 EFDC13 If13 there13 was13 no13 bias13 one13 way13 or13 the13 other13 between13 models13 the13 values13 greater13 or13 less13 than13 0513 ft13 would13 be13 equally13 distributed13 13 However13 results13 show13 a13 strong13 bias13 for13 greater13 deposition13 by13 the13 MNR13 model13 used13 in13 the13 FS

General MNR13 Effectiveness13 13 Many13 of13 the13 MNR13 effectiveness13 lines13 of13 evidence13 demonstrate13 that13 MNR13 may13 be13 effective13 in13 some13 areas13 of13 the13 site13 13 This13 is13 based13 on13 a13 review13 of13 incoming13 sediment13 concentrations13 surface13 to13 subsurface13 sediment13 ratios13 bathymetric13 change13 maps13 and13 grain13 size13 analysis13 13 13 However13 it13 should13 be13 noted13 that13 MNR13 is13 unlikely13 to13 be13 effective13 at13 all13 locations13 13 For13 example13 just13 off13 shore13 of13 the13 Gasco13 site13 the13 surface13 sediment13 PAH13 levels13 are13 much13 higher13 than13 subsurface13 sediments13 13 This13 is13 also13 an13 area13 that13 is13 dominated13 by13 coarse13 grained13 sediments13 13 These13 lines13 of13 evidence13 suggest13 MNR13 may13 have13 limited13 effectiveness13 in13 the13 vicinity13 of13 the13 Gasco13 site

General Concerns13 associated13 with13 the13 fate13 and13 transport13 models13 and13 MNR13 conclusions13 include13 the13 following

MNR13 Effectiveness13 13 The13 effectiveness13 of13 MNR13 was13 evaluated13 by13 empirical13 lines13 of13 evidence13 and13 predictive13 modeling13 using13 a13 hydrodynamic13 model13 sediment-shy‐transport13 model13 and13 contaminant-shy‐fate13 model13 13 Many13 of13 the13 empirical13 lines13 of13 evidence13 are13 overly13 generalized13 and13 may13 not13 hold13 true13 on13 smaller13 scales13 13 The13 modeling13 concludes13 that13

localized13 hot13 spots13 and13 SMAs13 are13 critical13 to13 predicting13 sediment13 COC13 concentrations13 13 Monitoring13 of13 sediment13 from13 200313 to13 200913 (Figure13 62-shy‐1)13 indicates13 that13 many13 of13 the13 highly13 contaminated13 areas13 including13 along13 the13 banks13 are13 net13 erosional13 The13 one13 river13 mile13 reach13 scale13 is13 too13 coarse13 to13 be13 meaningful13 13 For13 example13 between13 RM13 1113 and13 11813 the13 analysis13 concludes13 that13 this13 reach13 is13 generally13 not13 likely13 to13 recover13 13 However13 there13 are13 significant13 differences13 between13 the13 east13 and13 west13 sides13 of13 the13 river13 due13 to13 anthropogenic13 effects13 such13 as13 dredging13 and13 propwash13 13 As13 a13 result13 the13 west13 side13 of13 the13 river13 is13 likely13 to13 recover13 more13 quickly13 than13 the13 east13 side13 13 Similarly13 the13 draft13 FS13

remedial13 technologies13 and13 evaluating13 remedial13 action13 alternatives

It13 should13 be13 further13 noted13 that13 these13 areas13 incorporate13 many13 of13 the13 primary13 source13 areas13 at13 the13 site13 (RM13 11E13 Portland13 Shipyard13 Arkema13 GascoSiltronic13 and13 Willamette13 Cove)

Generalaction13 alternative13 do13 not13 substantially13 alter13 the13 course13 of13 natural13 recovery13 as13 generally13 observed13 at13 the13 Site13 There13 does13 not13 appear13 to13 be13 a13 need13 to13 identify13 any13 new13 areas13 of13 currently13 buried13 contamination13 that13 would13 have13 substantial13 impact13 on13 surface13 sediment13 concentrations13 The13 extent13 to13 which13 any13 such13 erosion13 is13 expected13 to13 occur13 is13 fully13 integrated13 into13 and13 accounted13 for13 in13 the13 long-shy‐term13 surface13 sediment13 modeling13 results13 presented13 in13 Sections13 613 and13 813 Therefore13 the13 importance13 or13 lack13 thereof13 of13 this13

If13 buried13 contamination13 is13 not13 a13 concern13 then13 what13 is13 the13 explanation13 for13 elevated13 levels13 of13 PAH13 and13 DDx13 contamination13 offshore13 of13 the13 Gasco13 and13 Arkema13 sites13 respectively13 despite13 the13 fact13 that13 the13 releases13 to13 the13 river13 ceased13 in13 the13 1950s13 13 Additionally13 given13 the13 amount13 of13 maintenance13 dredging13 that13 has13 occurred13 at13 River13 Mile13 11E13 and13 if13 significant13 sources13 have13 been13 addressed13 as13 represented13 why13 is13 there13 still13 such13 significant13 surface13 contamination13 13 Subsurface13 contamination13 requires13 serious13 consideration13 to13 evaluate13 its13 potential13 to13 pose13 unacceptable13 risk13 currently13 and13 in13 the13 future13 and13 ultimately13 to13 determine13 cleanup13 areas13 and13 remedial13 technologies13 13

(particularly13 modeling13 approaches13 that13 do13 not13 account13 for13 the13 impact13 of13 bed13 morphology13 changes13 on13 deposition13 rates13 over13 time)13 13 Site-shy‐specific13 circumstances13 must13 be13 objectively13 evaluated13 13 Also13 13 exposed13 concentrations13 immediately13 following13 the13 10013 year13 event13 should13 be13 depicted13 to13 bracket13 these13 results13 the13 10013 year13 event13 should13 also13 be13 run13 at13 year13 013 and13 results13 presented

Section13 21113 -shy‐13 Hydrology13 page13 2-shy‐3 short13 term13 stormwater13 discharges13 can13 be13 a13 higher13 percentage13 of13 flow13 than13 the13 average13 flow13 conditions13 described13 above

Section13 26213 -shy‐13 Chemical13 Distribution13 page13 2-shy‐41

PAH13 and13 DDx13 contamination13 at13 the13 site13 which13 shows13 a13 clear13 pattern13 of13 downstream13 migration13 from13 the13 large13 sources13 present13 in13 the13 vicinity13 of13 RM13 6

Section13 26313 -shy‐13 Sources13 Fate13 and13 Transport13 page13 2-shy‐41

While13 it13 may13 be13 true13 that13 most13 of13 the13 sediment13 contamination13 at13 the13 Site13 is13 associated13 with13 known13 or13 suspected13 historical13 sources13 and13 practices13 that13 have13 largely13 been13 discontinued13 or13 otherwise13 controlled13 there13 are13 instances13 such13 as13 the13 Gasco13 and13 Arkema13 sites13 where13 ongoing13 migration13 of13 contamination13 from13 upland13 sources13 continue13 to13

with13 upland13 sources13 exist13 within13 the13 Portland13 Harbor13 study13 area13 13 Examples13 include13 PCBs13 in13 stormwater13 at13 the13 Schnitzer13 site13 and13 in13 USGS13 stormwater13 samples13 near13 St13 Johns13 railroad13 bridge113 and13 the13 aforementioned13 DDx13 contamination13 at13 the13 Arkema13 site13 13 13 The13 FS13 report13 seems13 to13 acknowledge13 this13 possibility13 with13 the13 13 following13

the13 site13 based13 on13 application13 of13 the13 site-shy‐wide13 fate13 and13 transport13 model13 In13 addition13 the13 impacts13 from13 ongoing13 sources13 need13 to13 be13 evaluated13 on13 a13 more13 relevant13 scale13 than13 site-shy‐wide

1)13 Morace13 JL13 201213 13 Reconnaissance13 of13 Contaminants13 in13 Selected13 Wastewater-shy‐Treatment-shy‐Plant13 Effluent13 and13 Stormwater13 Runoff13 Entering13 the13 Columbia13 River13 Columbia13 River13 Basin13 Washington13 and13 Oregon13 2008-shy‐1013 13 US13 Geological13 Survey13 Scientific13 Investigations13 Report13 2012-shy‐506813 6813 p

The13 major13 fate13 and13 transport13 properties13 described13 on13 Page13 2-shy‐4313 should13 include13 physical13 mixing13 and13 bioturbation13 which13 could13 have13 an13 effect13 on13 contaminant13 distribution

Section13 4313 -shy‐13 RAL13 Range13 Selection13 and13 Detailed13 Methods13 by13 COC13 page13 4-shy‐8

The13 Portland13 Harbor13 Fate13 and13 Transport13 Model13 predicts13 that13 significant13 reductions13 in13 contaminant13 concentrations13 will13 take13 place13 within13 1013 years13 even13 under13 the13 no13 action13 scenario13 13 However13 data13 collected13 at13 the13 site13 over13 the13 past13 1013 years13 does13 not13 show13 appreciable13 reduction13 in13 contaminant13 concentrations13 13 This13 demonstrates13 the13 uncertainty13 in13 the13 long-shy‐term13 predictions13 generated13 by13 the13 fate13 and13 transport13 model13 13 As13 a13 result13 the13 evaluation13 of13 remedial13 action13 alternatives13 should13 be13 based13 primarily13

reduction13 associated13 with13 the13 various13 RALs13 for13 the13 T=013 curve13 but13 does13 not13 show13 any13 reduction13 for13 the13 T=1013 year13 curve13 as13 acres13 subject13 to13 active13 remediation13 increase13 13 It13 should13 be13 further13 noted13 that13 this13 reach13 of13 the13 river13 is13 not13 particularly13 depositional13 in13 the13 area13 where13 the13 contamination13 is13 present13 (See13 Figures13 21-shy‐213 and13 21-shy‐3)13 and13 is13 subject13 to13 anthropogenic13 effects13 (prop13 wash13 and13 maintenance13 dredging)13 which13 are13 expected13 to13 limit13 the13 effectiveness13 of13 MNR13 13 The13 fact13 that13 the13 model13 results13 do13 not13 show13 any13 decrease13 in13 contaminant13 concentrations13 associated13 with13 the13 T=1013 year13 curve13 demonstrates13 that13 this13 curve13 should13 not13 be13 used13 to13 evaluate13 remedial13 action13 alternatives13 at13 the13 Portland13 Harbor13 site

Section13 56113 -shy‐13 Erosion13 Due13 to13 River13 Currents13 page13 5-shy‐22

true13 due13 to13 the13 likelihood13 of13 the13 deposition13 of13 clean13 material13 as13 currents13 slow13 and13 material13 drops13 out13 of13 suspension13 the13 potential13 for13 contaminated13 material13 to13 be13 scoured13 and13 transported13 downstream13 exists

Section13 56313 -shy‐13 WindWake13 Wave13 Generated13 Erosion13 page13 5-shy‐24

Wind13 and13 wake13 driven13 waves13 are13 likely13 to13 be13 significant13 especially13 given13 the13 seasonal13 changes13 in13 river13 elevation13 13 This13 change13 in13 river13 stage13 will13 tend13 to13 expose13 a13 significant13 bank13 zone13 to13 waves13 of13 sufficient13 strength13 to13 generate13 erosional13 forces13 that13 must13 be13 considered13 in13 the13 FS13 13 A13 clear13 and13 more13 detailed13 consideration13 of13 wind13 and13 wave13 erosional13 forces13 should13 be13 included13 in13 this13 section

Section13 6113 -shy‐13 Identification13 of13 Technologies13 page13 6-shy‐2

The13 discussion13 of13 MNR13 should13 note13 that13 deposition13 by13 clean13 material13 is13 the13 primary13 natural13 recovery13 process13 at13 the13 Portland13 Harbor13 site13 (and13 other13 sediment13 sites13 nationally)13 13 The13 discussion13 of13 in-shy‐situ13 treatment13 should13 note13 that13 in-shy‐situ13 treatment13 in13 combination13 with13 EMNR13 may13 be13 effective13 for13 both13 chemical13 and13 physical13 isolation13 of13 contaminants

Section13 6213 -shy‐13 Screening13 of13 Remedial13 Technologies13 Figure13 62-shy‐15

Instead13 of13 portraying13 the13 surfacesubsurface13 ratios13 onto13 the13 model13 grid13 individual13 sediment13 core13 results13 should13 be13 mapped13 to13 develop13 surfacesubsurface13 rations13 13 If13 feasible13 depicting13 thiessen13 polygons13 of13 the13 surfacesubsurface13 rations13 should13 be13 developed

Section13 622113 -shy‐13 MNR13 Effectiveness13 page13 6-shy‐813 and13 Figure13 62-shy‐19

contamination13 13 The13 McCormick13 and13 Baxter13 data13 while13 reflecting13 a13 long13 time13 period13 also13 incorporates13 the13 timeframe13 of13 the13 sediment13 cleanup13 which13 took13 place13 in13 200513 13 Furthermore13 in13 the13 early13 1990s13 McCormick13 and13 Baxter13 was13 in13 the13 process13 of13 being13 shut13 down13 and13 the13 equipment13 and13 buildings13 abandoned13 13 If13 the13 199013 data13 is13 eliminated13 from13 the13 analysis13 there13 is13 virtually13 no13 temporal13 change13 noted13 in13 benzo(a)pyrene13 and13 naphthalene13 levels13 13 The13 early13 1990s13 data13 should13 be13 excluded13 from13 the13 evaluation13 because13 it13 is13 likely13 to13 be13 impacted13 (by13 increased13 concentrations)13 by13 the13 remedial13 actions

Section13 6221213 -shy‐13 Predictive13 Modeling13 Tools13 page13 6-shy‐22

Section13 6221313 -shy‐13 Weight-shy‐of-shy‐Evidence13 Assessment13 of13 MNR13 Effectiveness13 page13 6-shy‐22

In13 general13 weight13 of13 evidence13 (WOE)13 approaches13 can13 be13 well-shy‐suited13 for13 evaluating13 the13 relative13 strengths13 and13 weaknesses13 of13 remedial13 alternatives13 but13 only13 when13 inconsistencies13 between13 lines13 of13 evidence13 (LOE)13 are13 addressed13 and13 each13 LOE13 is13 assigned13 an13 appropriate13 weight13 and13 significance13 in13 the13 overall13 framework13 13 In13 the13 case13 of13 the13 WOE13 analysis13 for13 MNR13 in13 the13 Site13 EPA13 has13 identified13 flaws13 that13 lead13 to13 overly13 optimistic13 predictions13 for13 MNR13 success13 13 The13 following13 revisions13 should13 be13 made13 to13 produce13 a13 more13 reliable13 analysis13

would13 be13 sufficient13 to13 disrupt13 MNR13 it13 does13 not13 matter13 if13 the13 target13 final13 depth13 is13 1013 ft13 or13 5013 ft13 it13 only13 matters13 how13 much13 is13 being13 taken13 off13 in13 a13 single13 dredging13 event

of13 Category13 213 which13 states13 Category13 213 was13 assigned13 to13 areas13 where13 a13 given13 LOE13 suggests13 that13 natural13 recovery13 will13 likely13 occur13 but13 the13 degree13 of13 effectiveness13 is13 less13 certain13 13 This13 LOE13 does13 not13 suggest13 that13 natural13 recovery13 will13 likely13 occur13 if13 the13 surveys13 are13 not13 observing13 net13 sedimentation13 13 Such13 areas13 should13 be13 Category13 1

sources13 of13 other13 contaminants13 are13 not13 left13 to13 MNR

indicates13 that13 concentrations13 are13 approximately13 stable13 over13 time13 thus13 recovery13 is13 not13 occurring13 so13 such13 areas13 should13 be13 reclassified13 as13 Category13 1

look13 at13 time13 to13 meet13 target13 concentrations13 13 EPA13 understands13 that13 the13 model13 has13 already13 been13 run13 for13 this13 question13 13 If13 it13 is13 too13 complex13 to13 do13 this13 for13 all13 contaminants13 then13 an13 alternative13 would13 be13 to13 use13 PCBs13 as13 a13 surrogate13 as13 was13 done13 for13 the13 surfacesubsurface13 concentration13 ratios

sediment13 and13 transport13 it13 elsewhere

Section13 73213 -shy‐13 MNR13 page13 7-shy‐7

the13 Site13 and13 to13 assess13 exposures13 for13 receptors13 that13 use13 a13 broad13 area13 of13 the13 river13

Appendix13 La13 Section13 232313 page13 17

Equation13 2-shy‐2913 gives13 the13 erosion13 rate13 based13 on13 shear13 stress13 13 How13 does13 Equation13 2-shy‐3013 relate13 (ie13 when13 do13 we13 use13 it)

Refers13 to13 Figure13 2-shy‐1713 13 Particle13 diameters13 in13 text13 do13 not13 match13 those13 shown13 in13 figure13 13 Please13 provide13 edits13 to13 match13 diameters13 in13 text13 to13 those13 in13 figure

Erodibility13 parameters13 are13 averaged13 over13 the13 whole13 Site13 for13 cohesive13 bed13 areas13 13 Therefore13 in13 the13 places13 with13 above13 average13 erodibility13 (ie13 in13 about13 half13 the13 cores13 and13 in13 areas13 of13 the13 river13 with13 similar13 bed13 characteristics13 to13 these13 cores)13 the13 model13 will13 erroneously13 predict13 no13 erosion13 at13 some13 times13 13 Table13 2-shy‐613 shows13 that13 the13 critical13 shear13 stress13 ranges13 from13 00913 to13 07313 with13 an13 average13 value13 of13 03013 13 Erosion13 should13 be13 evaluated13 on13 a13 smaller-shy‐scale13 area

Appendix13 La13 Figure13 2-shy‐75

The13 method13 of13 calculating13 the13 statistics13 of13 the13 absolute13 difference13 in13 net13 sedimentation13 rate13 is13 not13 appropriate13 13 Using13 this13 method13 over-shy‐predictions13 and13 under-shy‐predictions13 cancel13 out13 so13 it13 cannot13 show13 how13 accurate13 the13 model13 predictions13 were13 only13 whether13 they13 had13 an13 overall13 bias13 13 Instead13 after13 step13 113 generate13 a13 third13 data13 set13 which13 is13 the13 absolute13 value13 of13 the13 difference13 between13 the13 predicted13 and13 measured13 value13 in13 each13 zone13 13 Then13 take13 the13 mean13 of13 that13 data13 set13 13 That13 will13 estimate13 how13 well13 the13 model13 matches13 the13 measured13 sedimentation13 on13 a13 given13 spatial13 scale

accuracy13 is13 ~2513 cmyr13 then13 an13 area13 classified13 as13 Category13 313 may13 actually13 be13 experiencing13 net13 erosion13 of13 1513 cmyr13 13 This13 is13 the13 main13 problem13 with13 the13 sediment13 modeling13 13

optimistic13 to13 use13 it13 to13 try13 to13 give13 a13 sedimentation13 rate13 to13 within13 113 cmyr13 13 Although13 this13 approach13 is13 acceptable13 the13 draft13 FS13 should13 acknowledge13 uncertainty13 associated13 with13 estimating13 sedimentation13 rates13 to13 within13 113 cmyr

This13 figure13 should13 be13 corrected13 to13 match13 the13 text13 on13 page13 4613 or13 else13 vice13 versa13 13 The13 runs13 listed13 in13 the13 text13 (713 1113 1213 26)13 are13 not13 the13 ones13 shown13 here13 (713 913 1213 26)

43 Technology13 Evaluation13 -shy‐13 EMNR

Section13 632113 -shy‐13 EMNR13 Effectiveness13 page13 6-shy‐34

The13 discussion13 of13 the13 effectiveness13 of13 EMNR13 should13 take13 into13 account13 anthropogenic13 impacts13 13 Due13 to13 dredging13 and13 propwash13 it13 seems13 unlikely13 that13 EMNR13 would13 be13 effective13 in13 the13 RM13 11E13 area13 13 Propwash13 should13 also13 be13 taken13 into13 account13 in13 assessing13 the13 effectiveness13 of13 EMNR13 in13 Swan13 Island13 Lagoon

where13 EMNR13 is13 expected13 to13 be13 effective13 and13 implementable13 and13 in13 areas13 where13 RGs13 are13 exceeded

45 Technology13 Evaluation13 -shy‐13 In-shy‐Situ13 Treatment

General No13 pilot13 or13 field13 scale13 treatability13 studies13 have13 been13 proposed13 in13 the13 FS13 13 Treatability13 studies13 may13 be13 appropriate13 during13 remedial13 design13 depending13 on13 the13 selected13 remedy

Section13 6241213 -shy‐13 Grasse13 River13 New13 York13 page13 6-shy‐40 This13 is13 not13 accurate13 according13 to13 the13 Activated13 Carbon13 Pilot13 Study13 Construction13 Documentation13 Report13 (2007)13 which13 states13 on13 average13 approximately13 3013 to13 5013 percent13

variability13 in13 the13 application13 of13 activated13 carbon13 is13 likely13 a13 significant13 contributing13 factor13 to13 the13 observation13 of13 unaccounted13 mass13 identified13 through13 the13 post13 application13

It13 appears13 that13 the13 small-shy‐scale13 variability13 contributes13 to13 the13 lack13 of13 closure13 on13 the13 mass13 balance13 but13 being13 able13 to13 account13 for13 only13 30-shy‐5013 of13 the13 mass13 of13 a13 material13 added13 to13 the13 river13 in13 conjunction13 with13 not13 finding13 AC13 in13 sediment13 at13 depths13 greater13 than13 313 inches13 strongly13 suggests13 that13 AC13 was13 carried13 away13 from13 the13 test13 site13 13 If13 AC13 is13 proposed13 for13 use13 at13 Portland13 Harbor13 a13 pilot13 study13 to13 assess13 placement13 techniques13 would13 be13 needed13

47 Technology13 Evaluation13 -shy‐13 Capping

General The13 placement13 of13 numerous13 caps13 within13 Portland13 Harbor13 may13 have13 a13 cumulative13 effect13 on13 river13 dynamics13 at13 the13 site13 13 The13 FS13 should13 consider13 the13 effect13 of13 13 multiple13 capping13 remedies13 on13 river13 dynamics13 flood13 stages13 and13 flood13 storage13 13 In13 addition13 the13 impact13 of13 any13 changes13 in13 river13 dynamics13 should13 be13 incorporated13 into13 the13 fate13 and13 transport13 model13 used13 in13 the13 FS13 to13 support13 the13 evaluation13 of13 MNR

General The13 effectiveness13 evaluation13 for13 active13 capping13 assumes13 that13 groundwater13 plumes13 in13 SMAs13 9U13 and13 1413 will13 be13 controlled13 and13 will13 naturally13 attenuate13 Ongoing13 contamination13 from13 groundwater13 may13 affect13 the13 short-shy‐term13 (and13 possibly13 long-shy‐term)13 effectiveness13 of13 active13 capping13 13 Discuss13 the13 timeframe13 for13 attenuation13 and13 potential13 impacts13 on13 effectiveness13 of13 capping

Section13 625113 -shy‐13 Capping13 Effectiveness13 page13 6-shy‐46

The13 capping13 effectiveness13 evaluation13 should13 consider13 hydrophobic13 bioaccumulative13 contaminants13 with13 low13 human13 health13 AWQC13 such13 as13 PCBs13 in13 addition13 to13 the13 more13 mobile13 groundwater13 contaminants13 such13 as13 benzene13 chlorobenzene13 and13 vinyl13 chloride13 13 Points13 of13 compliance13 should13 be13 pore13 water13 concentrations13 at13 the13 groundwatersurface13 water13 interface13 rather13 than13 a13 depth13 integrated13 surface13 water13 prediction13 to13 account13 for13 bottom13 feeding13 fish13 and13 epibenthic13 invertebrates13

Section13 626213 -shy‐13 Implementability13 (Reactive13 capping)13 page13 6-shy‐54

The13 reactive13 capping13 effectiveness13 discussion13 should13 note13 that13 reactive13 capping13 may13 reduce13 the13 overall13 thickness13 of13 the13 cap13 thus13 allowing13 placement13 in13 areas13 that13 would13 otherwise13 not13 be13 capable13 due13 to13 water13 depth13 requirements

51 Technology13 Evaluation13 -shy‐13 Dredging

General The13 LWG13 applies13 numerous13 assumptions13 regarding13 the13 use13 of13 remedial13 dredging13 actions13 that13 introduce13 biases13 against13 dredging13 alternatives13 13 These13 biases13 tend13 to13 portray13 the13 more13 dredging-shy‐intensive13 alternatives13 as13 far13 less13 desirable13 than13 information13 from13 other13 dredge13 projects13 portray13

actions13 13 However13 this13 is13 not13 necessarily13 the13 case13 13 NOAA13 has13 indicated13 they13 would13 support13 such13 actions13 so13 long13 as13 isolation13 management13 measures13 could13 be13 implemented13 in13 the13 work13 area13 to13 prevent13 or13 substantially13 reduce13 salmonid13 exposures13 to13 contaminants13

appropriate13 13 For13 example13 in13 some13 areas13 of13 the13 Site13 hydraulic13 dredging13 would13 be13 faster13 and13 result13 in13 fewer13 andor13 reduced13 contaminant13 releases13

seems13 arbitrary13 and13 overly13 conservative13

until13 many13 years13 after13 remediation13 begins13 13 EPA13 maintains13 that13 areas13 with13 higher13 contamination13 should13 be13 removed13 first13 to13 achieve13 such13 early13 reductions

Taken13 cumulatively13 these13 assumptions13 unrealistically13 increase13 the13 duration13 of13 many13 Site13 remedial13 alternatives13 in13 particular13 those13 that13 rely13 more13 heavily13 on13 dredging13 actions13 13 EPA13 believes13 that13 a13 recalibration13 of13 these13 assumptions13 would13 introduce13 reasonable13 cost-shy‐effective13 and13 practicable13 alternatives13 that13 would13 allow13 for13 the13 removal13 of13 larger13 volumes13 of13 more13 contaminated13 sediments13 thereby13 producing13 more13 substantial13 reductions13 in13 ecological13 (and13 human13 health)13 risks

resuspension13 and13 release13 may13 be13 controlled13 through13 the13 use13 of13 water13 quality13 controls13 such13 as13 sheet13 piles13 and13 silt13 curtains13 and13 that13 residuals13 may13 be13 managed13 by13 placement13 of13 a13 clean13 sand13 layer13 as13 soon13 as13 is13 practicable13 following13 completion13 of13 dredging13 activities

Additionally13 Section13 627313 on13 Best13 Management13 Practices13 (BMPs)13 inappropriately13 disregards13 some13 technologies13 Silt13 curtains13 and13 rigid13 containment13 should13 continue13 to13 be13 considered13 as13 BMPs13 in13 areas13 where13 they13 may13 be13 effective13 particularly13 as13 controls13 on13 suspended13 sediment13 The13 use13 of13 engineering13 controls13 to13 lessen13 releases13 from13 dredging13 should13 not13 be13 screened13 out13 rather13 employed13 judiciously13 in13 areas13 of13 high13 contaminant13 concentrations13 in13 conducive13 environments

Section13 6272113 -shy‐13 StructureAccess13 Issues13 page13 6-shy‐59

EPA13 disagrees13 that13 all13 structures13 affect13 implementability13 of13 dredging13 13 EPA13 disagrees13 with13 the13 sub-shy‐SMA13 limitations13 in13 Section13 6272113 in13 that13 structures13 should13 be13 evaluated13 for13 the13 potential13 for13 removal13 or13 replacement13 rather13 than13 simply13 assuming13 that13 removal13 is13 infeasible13 in13 their13 vicinity13 13 LWG13 bases13 this13 assumption13 on13 the13 costs13 of13 removal13 and13 replacement13 of13 structures13 which13 is13 more13 appropriately13 addressed13 under13 costs13 13 A13 review13 of13 structures13 should13 be13 conducted13 to13 see13 which13 are13 potentially13 removable13 or13 replaceable13 13 Particularly13 the13 FS13 must13 evaluate13 structure13 removal13 where13 structures13 are13 derelict13 and13 not13 in13 use13 or13 cannot13 be13 used13 due13 to13 safety13 concerns13 or13 have13 a13 limited13 useful13 life13 and13 combined13 with13 high13 concentration13 contamination13 that13 would13 not13 be13 effectively13 addressed13 due13 to13 the13 structures13 existence13 13

54a Technology13 Evaluation13 -shy‐13 Dredging

Section13 627313 -shy‐13 Removal13 Best13 Management13 Practices13 (BMPs)13 page13 6-shy‐67

The13 evaluation13 of13 dredging13 in13 the13 FS13 over13 emphasizes13 the13 short13 term13 impacts13 of13 dredging-shy‐based13 remedies13 under13 estimates13 the13 effectiveness13 and13 implementability13 of13 sheet13 pile13 enclosures13 and13 over13 estimates13 the13 length13 of13 time13 that13 dredging13 would13 be13 required13 13 The13 draft13 FS13 argues13 against13 the13 use13 of13 silt13 curtains13 and13 sheet13 pile13 walls13 as13 dredge13 BMPs13 but13 for13 the13 following13 reasons13 EPA13 believes13 that13 silt13 curtains13 and13 sheet13 pile13 walls13 should13 be13 retained13 as13 options13 for13 remedial13 design13 in13 order13 to13 facilitate13 dredging13 in13 areas13 of13 higher13 contaminant13 concentrations

113 Containment13 devices13 such13 as13 sheet13 pile13 walls13 and13 silt13 curtains13 will13 limit13 the13 spread13 of13 dredge13 residuals13 thus13 enabling13 higher13 production13 rates13 and13 decreasing13 the13 total13 time13 needed13 to13 reach13 cleanup13 goals13 while13 minimizing13 adverse13 impacts13 to13 biota13 13 Effective13 containment13 of13 contamination13 during13 dredging13 may13 allow13 dredging13 to13 occur13 outside13 the13 fish13 window13 further13 accelerating13 the13 pace13 of13 cleanup

213 The13 objections13 raised13 in13 the13 draft13 FS13 to13 the13 use13 of13 sheet13 pile13 walls13 and13 silt13 curtains13 can13 be13 overcome13

beyond13 the13 containment13 because13 the13 concentrated13 flow13 conditions13 beneath13 the13 silt13 curtains13 resulted13 in13 localized13 scour13 and13 resuspension13 at13 Grasse13 River13 and13 the13 double13 silt13 curtain13 system13 was13 abandoned13 after13 being13 determined13 to13 be13 ineffective13 due13 to13 variable13 current13 speed13 and13 direction13 at13 Massena13 13 Flow13 conditions13 on13 these13 rivers13 are13 not13 necessarily13 the13 same13 as13 those13 in13 potential13 dredging13 footprints13 at13 Portland13 Harbor13 13 Most13 of13 the13 areas13 in13 Portland13 Harbor13 with13 high13 contaminant13 concentrations13 (ie13 the13 areas13 most13 likely13 to13 be13 dredged)13 are13 near13 the13 riverbanks13 and13 thus13 have13 lower13 current13 speeds13 and13 a13 lower13 probability13 of13 release13 13

was13 conducted13 to13 determine13 likelihood13 of13 scour13 and13 concrete13 pads13 were13 placed13 around13 the13 walls13 to13 prevent13 scour13 and13 stabilize13 the13 walls13 13 Similar13 methods13 could13 be13 used13 at13 Portland13 Harbor13 if13 needed13

respect13 to13 the13 navigation13 channel13 and13 should13 be13 minimal13 at13 Portland13 Harbor13 13 The13 Hudson13 River13 silt13 curtain13 was13 placed13 across13 the13 entire13 river13 channel13 and13 had13 to13 be13 opened13 frequently13 to13 allow13 boat13 traffic13 At13 Portland13 Harbor13 this13 could13 be13 avoided13 as13 the13 areas13 to13 be13 dredged13 are13 near13 the13 riverbanks13 and13 small13 enough13 to13 allow13 temporary13 isolation13 from13 the13 rest13 of13 the13 river13 (ie13 boats13 could13 go13 around13 without13 requiring13 the13 curtains13 to13 be13 moved)

(Comment13 continued13 below)

54b Technology13 Evaluation13 -shy‐13 Dredging

(Continued13 from13 Comment13 54a)

of13 large13 heavy13 debris13 pieces13 including13 discarded13 appliances13 demonstrating13 that13 it13 can13 be13 done13 13 They13 conducted13 reconnaissance13 using13 side-shy‐scan13 sonar13 to13 help13 with13 placement13

the13 boundary13 of13 contamination13 13

containment13 at13 Hudson13 River13 while13 imperfect13 was13 better13 than13 no13 containment13 at13 all13 and13 the13 EPA13 review13 of13 Hudson13 Rivers13 Phase13 113 Operations13 (httphudsondredgingdatacomdocumentspdfEPA20Oversight20Report20Finalpdf13 )13 concluded13 that13 containment13 should13 continue13 to13 be13 used13 13 Acknowledging13 the13 possibility13 of13 leaks13 monitoring13 should13 be13 conducted13 during13 dredging13 to13 evaluate13 the13 effectiveness13 of13 containment13 devices13

It13 should13 be13 noted13 that13 contaminants13 were13 successfully13 contained13 during13 the13 removal13 action13 at13 Gasco13 several13 years13 ago13 13 All13 this13 information13 suggests13 that13 removal13 based13 remedial13 technologies13 implemented13 with13 appropriate13 containment13 measures13 can13 be13 effective13 in13 meeting13 RAOs13 13 Silt13 curtains13 and13 sheet13 pile13 walls13 should13 be13 retained13 as13 options13 for13 remedial13 design13 13 The13 FS13 should13 reevaluate13 the13 use13 of13 silt13 curtains13 and13 sheet13 pile13 walls13 as13 options13 for13 reducing13 short13 term13 impacts13 and13 allowing13 dredging13 to13 take13 place13 outside13 the13 in-shy‐water13 work13 windows13 13 This13 evaluation13 should13 take13 into13 account13 the13 experience13 at13 other13 sites13 as13 described13 above13 and13 summaries13 of13 this13 information13 should13 be13 included13 in13 the13 text

Section13 82213 -shy‐13 Overall13 Protection13 of13 Human13 Health13 and13 the13 Environment13 pages13 8-shy‐1013 and13 8-shy‐2713 Figure13 822-shy‐1

The13 plots13 presented13 in13 Figures13 822-shy‐113 through13 613 show13 that13 there13 is13 essentially13 no13 reduction13 in13 surface13 sediment13 concentrations13 associated13 with13 Alternative13 F-shy‐r13 (the13 most13 aggressive13 alternative13 evaluated13 in13 the13 draft13 FS13 Report)13 until13 year13 2513 13 Even13 accounting13 for13 the13 releases13 during13 dredging13 activities13 it13 does13 not13 seem13 reasonable13 to13 assume13 that13 no13 reduction13 in13 surface13 concentrations13 are13 achieved13 despite13 many13 years13 of13 active13 remediation13 13 The13 BMPs13 described13 in13 the13 FS13 such13 as13 the13 use13 of13 silt13 curtains13 or13 sheet13 pile13 containment13 and13 the13 placement13 of13 clean13 backfill13 immediately13 following13 dredging13 activities13 should13 improve13 the13 overall13 effectiveness13 of13 dredging13 13 At13 OU-shy‐113 of13 the13 Fox13 River13 site13 where13 neither13 silt13 curtain13 nor13 sheet13 pile13 controls13 were13 required13 during13 dredging13 activities13 fish13 tissue13 concentrations13 declined13 rapidly13 in13 response13 to13 the13 cleanup13 action13 13 As13 stated13 in13 Lower13 Fox13 River13 Operable13 Unit13 1

the13 long-shy‐term13 effectiveness13 of13 dredging13 as13 a13 component13 of13 sediment13 remedies13 13 The13 failure13 of13 the13 draft13 FS13 to13 document13 these13 reductions13 demonstrates13 the13 bias13 associated13 with13 the13 long-shy‐term13 effectiveness13 evaluation13 of13 dredging13 in13 the13 draft13 FS

Section13 822413 -shy‐13 Dredging13 Removal13 page13 8-shy‐15

Increases13 in13 fish13 tissue13 concentrations13 are13 temporary13 (Fox13 River13 and13 Hudson13 River13 results13 showed13 elevated13 concentrations13 for13 one13 year13 and13 then13 an13 improvement)13 13 The13 draft13 FS13 overstates13 this13 occurrence13 as13 a13 reason13 not13 to13 dredge

Section13 8242413 -shy‐13 Long-shy‐Term13

Dredging13 Removal13 page13 8-shy‐29

provide13 moderate13 to13 high13 level13 of13 risk13 reduction13 and13 low13 to13 moderate13 residual13 risk13 depending13 on13 the13 effectiveness13 of13 dredging13 and13 use13 of13 backfill13 material13 With13 respect13 to13 the13 adequacy13 and13 reliability13 of13 controls13 for13 residual13 risk13 this13 technology13 may13 provide13 high13 control13 due13 to13 removal13 of13 contaminants13 if13 residual13 contamination13 is13 below13

the13 draft13 FS13 downplays13 the13 effectiveness13 of13 dredging13 technologies13

Appendix13 Ia13 page13 1

Re13 Model13 inputs13 included13 SMA-shy‐specific13 sediment13 data13 and13 river13 conditions13 and13 considered13 a13 range13 from13 the13 average13 to13 the13 maximum13 bulk13 sediment13 contaminant13 concentration13 in13 each13 SMA13 for13 the13 contaminants13 listed13 in13 draft13 FS13 Appendix13 C13 Please13 provide13 a13 description13 of13 how13 bulk13 sediment13 contaminant13 concentration13 was13 calculated13 as13 this13 may13 influence13 model13 projections13 (including13 associated13 TSS13 concentrations)13 13 Also13 provide13 a13 table13 of13 the13 concentrations13 used13 as13 model13 inputs13 as13 bulk13 sediment13 concentrations13 may13 not13 be13 indicative13 of13 contaminant13 concentrations13 suspended13 while13 dredging13 in13 localized13 hotspots

Re13 Background13 water13 concentrations13 were13 added13 to13 the13 computed13 constituent13 concentration13 as13 described13 above13 Please13 provide13 a13 table13 of13 background13 water13 concentrations13 used13 as13 model13 inputs

Re13 Input13 values13 used13 for13 these13 variables13 were13 developed13 by13 averaging13 available13 Site13 and13 geotechnical13 data13 within13 the13 evaluation13 area13 Model13 sensitivity13 analyses13 should13 be13 conducted13 using13 site13 and13 geotechnical13 data13 that13 will13 provide13 best-shy‐13 and13 worst-shy‐case13 resuspension13 and13 sediment13 transport13 scenarios13 13 These13 scenarios13 will13 aid13 in13 the13 evaluation13 of13 sediment13 management13 practices13 (ie13 rigid13 containment13 silt-shy‐curtains13 monitor13 only)13 that13 may13 be13 required13 to13 assess13 downstream13 contaminant13 transport13 as13 a13 result13 of13 dredging13 activities13 under13 the13 range13 of13 conditions13 expected13 to13 be13 encountered13 during13 the13 dredging13 work13 window

Re13 Background13 TSS13 concentrations13 were13 neither13 evaluated13 nor13 included13 in13 the13 DREDGE-shy‐calculated13 TSS13 concentrations13 Please13 provide13 justification13 as13 to13 why13 background13 TSS13 concentrations13 were13 excluded13 from13 DREDGE13 model13 simulations

Re13 Additional13 evaluations13 were13 performed13 using13 a13 range13 of13 DREDGE13 input13 variables13 (bucket13 size13 specific13 gravity13 lateral13 dispersion13 coefficient13 river13 velocity13 and13 particle13 size)13 in13 a13 preliminary13 sensitivity13 analysis13 for13 these13 parameters13 Please13 provide13 all13 input13 variables13 and13 output13 from13 sensitivity13 analyses13 to13 allow13 for13 more13 in-shy‐depth13 evaluations13 of13 model13 projections

Re13 Sensitivity13 analyses13 on13 individual13 input13 variables13 discussed13 in13 the13 Table13 213 notes13 indicate13 that13 TSS13 values13 could13 increase13 by13 a13 factor13 of13 213 or13 more13 when13 modifying13 individual13 variables13 however13 even13 with13 the13 increased13 TSS13 results13 no13 further13 exceedances13 were13 noted13 by13 the13 sensitivity13 evaluation13 There13 is13 no13 discussion13 or13 presentation13 of13 values13 used13 for13 the13 various13 inputs13 during13 sensitivity13 analyses13 in13 Table13 113 13 A13 table13 of13 all13 input13 variables13 and13 associated13 outputs13 used13 during13 sensitivity13 analyses13 should13 be13 provided13 and13 the13 existing13 sentence13 in13 the13 appendix13 should13 be13 removed

Appendix13 Ia13 Table13 1

Exceedance13 thresholds13 and13 their13 corresponding13 sources13 should13 be13 presented13 in13 Table13 1

Appendix13 Ib13 page13 2

Re13 Because13 the13 use13 of13 multiple13 cleanup13 passes13 has13 been13 demonstrated13 to13 be13 ineffective13 the13 FS13 does13 not13 consider13 this13 practice13 appropriate13 at13 this13 Site13 To13 the13 extent13 feasible13 the13 possible13 use13 of13 multiple13 cleanup13 passes13 should13 be13 evaluated13 using13 the13 model

Re13 The13 overdredge13 sediment13 was13 assumed13 to13 be13 at13 a13 concentration13 at13 or13 below13 the13 RAL13 The13 assumption13 that13 the13 overdredge13 sediment13 will13 be13 at13 or13 below13 the13 RAL13 is13 not13 conservative13 13 The13 contaminant13 concentrations13 in13 the13 overdredge13 prism13 should13 reflect13 the13 concentrations13 in13 overdredge13 sediments13 anticipated13 to13 be13 encountered13 in13 the13 field13 following13 dredging13 13 Furthermore13 please13 specify13 whether13 the13 concentrations13 are13 assumed13 to13 be13 either13 AT13 or13 BELOW13 the13 RAL13 as13 this13 distinction13 could13 have13 a13 significant13 impact13 on13 model13 projections13 13 The13 anticipated13 overdredge13 contaminant13 concentrations13 should13 also13 be13 provided13 in13 a13 table13 for13 each13 dredge13 area13 so13 that13 a13 more13 in-shy‐depth13 review13 of13 model13 projections13 can13 be13 performed

Re13 After13 placement13 as13 residuals13 cover13 the13 material13 was13 considered13 to13 partially13 mix13 with13 the13 residuals13 layer13 (since13 the13 residuals13 cover13 would13 not13 be13 designed13 to13 function13

and13 depth13 of13 mixing13 is13 assumed

Appendix13 Ib13 page13 5 RALs13 primarily13 by13 diluting13 the13 residual13 sediment13 matrix13 with13 clean13 materials13 Sediments13 exceeding13 RALs13 following13 dredging13 should13 be13 capped13 using13 engineered13

isolation13 caps13 not13 assumed13 to13 simply13 mix13 with13 cover13 materials13 13 This13 is13 an13 overarching13 comment13 for13 the13 entire13 appendix13

69 Disposal13 Options

General Construction13 of13 CDFs13 andor13 CADs13 may13 impact13 habitat13 13 Costs13 associated13 with13 habitat13 mitigation13 for13 CDFs13 andor13 CADs13 should13 be13 included13 in13 the13 cost13 estimates13 13

The13 evaluation13 of13 implementability13 must13 consider13 Oregon13 Department13 of13 State13 Lands13 (DSL)13 13 necessary13 agreements13 to13 allow13 CDFCAD13 facilities13

On-shy‐site13 CADs13 and13 CDFs13 will13 need13 to13 consider13 the13 potential13 for13 measureable13 increase13 in13 flood13 risk13 and13 measureable13 decrease13 in13 flood13 storage13 13 The13 implementability13 evaluation13 should13 provide13 more13 detail13 regarding13 these13 substantive13 requirements13 and13 how13 that13 will13 be13 addressed13 during13 remedial13 design13 ifwhen13 a13 disposal13 site13 is13 selected13 13 13

70 Technology13 Evaluation13 -shy‐13 Assignments

General Selection13 of13 specific13 technologies13 within13 integrated13 alternatives13 13 It13 is13 unclear13 how13 specific13 technologies13 were13 designated13 for13 individual13 sub-shy‐SMAs13 13 Descriptions13 in13 Section13 5-shy‐413 and13 technologies13 Table13 72-shy‐113 are13 somewhat13 helpful13 but13 it13 does13 not13 make13 clear13 which13 remedies13 will13 be13 applied13 for13 what13 reason13 or13 under13 what13 conditions13 13 If13 this13 material13 is13 in13 an13 Appendix13 somewhere13 it13 should13 be13 brought13 forward13 as13 it13 is13 fundamental13 to13 evaluating13 alternatives13 13 The13 lack13 of13 consideration13 of13 environmental13 conditions13 for13 selecting13 some13 remedies13 is13 disconcerting13 13 For13 example13 it13 appears13 that13 in-shy‐situ13 treatment13 is13 designated13 for13 open13 water13 areas13 without13 consideration13 of13 sediment13 slope13 or13 water13 flows13 13 Language13 in13 Chapter13 713 seems13 to13 relate13 that13 all13 integrated13 remedies13 would13 be13 interchangeable13 13 A13 new13 table13 or13 figure13 should13 be13 developed13 that13 clearly13 depicts13 the13 decision13 tree13 for13 determining13 which13 remedies13 are13 applied13 in13 which13 areas13 for13 what13 reason13 13 The13 text13 should13 further13 explain13 and13 support13 this13 process13 13 At13 present13 the13

this13 should13 be13 described13 in13 a13 clearer13 fashion13 than13 the13 text13 presented13 on13 page13 7-shy‐4

General Sub-shy‐SMAs13 -shy‐13 We13 agree13 that13 information13 about13 uses13 is13 useful13 for13 determining13 the13 feasibility13 of13 remedial13 technologies13 However13 we13 disagree13 that13 all13 structures13 affect13 implementability13 of13 dredging13 A13 review13 of13 structures13 should13 be13 conducted13 to13 see13 which13 are13 potentially13 removable13 or13 replaceable13 13 In13 addition13 the13 use13 of13 specialized13 dredge13 equipment13 (eg13 excavators13 with13 narrow13 buckets)13 should13 be13 considered13 for13 removal13 around13 structures

Section13 7213 -shy‐13 Remedial13 Technology13 Options13 page13 7-shy‐413 and13 Table13 72-shy‐1

The13 draft13 FS13 Report13 states13 13 The13 assignment13 of13 technologies13 for13 removal13 versus13 integrated13 options13 is13 summarized13 in13 Table13 72-shy‐113 13 However13 the13 factors13 considered13 for13 the13 purpose13 of13 identifying13 the13 various13 sub-shy‐SMAs13 is13 limited13 13 There13 are13 a13 number13 of13 key13 site13 specific13 factors13 that13 are13 not13 taken13 into13 account13 when13 designating13 sub-shy‐SMAs13 13 These13 include13 erosiondeposition13 areas13 current13 and13 future13 land13 and13 waterway13 use13 contaminant13 mobility13 potential13 hot13 spots13 of13 location13 etc13 13 Use13 of13 a13 more13 comprehensive13 set13 of13 physical13 contaminant13 and13 land13 and13 waterway13 use13 characteristics13 will13 allow13 for13 development13 of13 a13 more13 refined13 set13 of13 remedial13 alternatives13 to13 be13 evaluated13 in13 the13 draft13 FS13 (see13 also13 Section13 5413 comments)

Section13 7213 -shy‐13 Remedial13 Technology13 Options13 page13 7-shy‐4

(placement13 of13 AC13 or13 a13 similar13 reagent13 onto13 surface13 sediments)13 engineered13 caps13 (including13 armor13 layers13 habitat13 layers13 andor13 other13 variations)13 or13 other13 similar13 in-shy‐place13

engineered13 caps13 in13 all13 of13 the13 in-shy‐place13 technology13 subSMAs13 while13 the13 other13 cost13 estimate13 assumes13 in13 situ13 treatment13 in13 all13 of13 the13 in-shy‐place13 technology13 subSMAs13 except13 the13

Section13 82213 -shy‐13 Overall13 Protection13 of13 Human13 Health13 and13 the13 Environment13 pages13 8-shy‐913 and13 8-shy‐29

The13 technology13 specific13 subsections13 presented13 in13 this13 section13 make13 general13 statements13 about13 the13 overall13 protectiveness13 of13 the13 various13 remedial13 technologies13 13 However13 because13 the13 discussion13 is13 so13 general13 it13 does13 not13 provide13 useful13 information13 13 For13 example13 under13 dredging13 the13 draft13 FS13 Report13 states13

type13 of13 cover13 applied13 the13 physiochemical13 properties13 of13 the13 contaminant13 the13 potential13 for13 erosion13 13 Without13 an13 understanding13 of13 these13 site13 specific13 factors13 it13 is13 not13 possible13 to13 understand13 the13 degree13 to13 which13 removal13 technologies13 will13 reduce13 risk

75 Construction13 Sequencing13 and13 Durations

General The13 construction13 sequencing13 is13 inappropriate13 in13 that13 it13 does13 not13 address13 the13 most13 contaminated13 areas13 first13 The13 durations13 of13 construction13 are13 also13 inappropriately13 constrained13 by13 assuming13 no13 in-shy‐water13 remedial13 actions13 can13 occur13 outside13 the13 in-shy‐water13 work13 window13 13 An13 appropriate13 sequencing13 for13 each13 alternative13 that13 addresses13 the13 areas13 posing13 the13 highest13 risk13 first13 and13 maximizes13 technology13 efficiencies13 to13 complete13 the13 remedy13 in13 the13 shortest13 reasonable13 timeframe13 should13 be13 incorporated13 into13 the13 remedial13 strategy13 13 The13 associated13 cost13 estimates13 will13 need13 to13 be13 revised13 based13 on13 the13 revised13 construction13 sequencing13 and13 technology13 assumptions

76 Integration13 of13 Source13 Control13 Measures

General The13 effectiveness13 of13 the13 sediment13 remedy13 will13 be13 closely13 tied13 to13 the13 effectiveness13 of13 upland13 source13 control13 efforts13 13 This13 is13 a13 very13 challenging13 technical13 issue13 that13 will13 require13 a13 significant13 monitoring13 and13 adaptive13 management13 effort13 13 It13 should13 also13 enter13 into13 decisions13 on13 implementation13 schedules13 for13 both13 upland13 and13 sediment13 remedies

77 Evaluation13 of13 Alternatives

General Explain13 why13 concentrations13 do13 not13 decrease13 as13 quickly13 under13 Alternative13 F13 compared13 to13 other13 alternatives13 13 Alternative13 F13 would13 be13 more13 effective13 if13 it13 targeted13 the13 same13 areas13 as13 the13 other13 alternatives13 for13 the13 first13 ~1013 yrs13 and13 then13 continued13 to13 clean13 up13 additional13 areas

General The13 comparative13 analysis13 of13 alternatives13 concludes13 that13 all13 alternatives13 besides13 No13 Action13 are13 protective13 amp13 meet13 sediment13 RAOs13 amp13 that13 the13 balancing13 factor13 that13 differentiates13 between13 alternatives13 is13 short-shy‐term13 effectiveness13 (ie13 the13 more13 you13 dredge13 the13 greater13 the13 detrimental13 impact13 to13 the13 environment)13 13 This13 is13 largely13 based13 on13

problematic13 applications13 are13 discussed13 in13 detail13 but13 not13 the13 successful13 local13 application13 at13 Arco)13 3)13 their13 FampT13 model13 that13 predicts13 wide-shy‐scale13 natural13 burial13 and13 4)13 that13 waiting13 30+13 years13 for13 MNR13 to13 achieve13 RAOsRGs13 is13 acceptable

The13 FS13 bases13 a13 significant13 portion13 of13 the13 overall13 effectiveness13 evaluation13 on13 the13 duration13 of13 the13 cleanup13 13 As13 a13 result13 remedial13 alternatives13 that13 remove13 more13 material13 or13 are13 of13 a13 greater13 duration13 receive13 a13 lower13 overall13 score13 (ie13 the13 FS13 presents13 a13 bias13 against13 removal13 based13 remedies)13 13 This13 outcome13 is13 based13 on13 the13 failure13 to13 properly13 consider13 hot13 spots13 of13 contamination13 adequacy13 of13 controls13 (which13 takes13 into13 account13 the13 amount13 of13 material13 left13 in13 place)13 reductions13 in13 toxicity13 mobility13 and13 volume13 through13 treatment13 and13 the13 uncertainty13 in13 long-shy‐term13 projections13 of13 risk13 reduction13 13 In13 addition13 the13 analysis13 does13 not13 properly13 consider13 sheet13 pile13 installation13 as13 a13 method13 to13 reduce13 water13 column13 impacts13 and13 perhaps13 shorten13 the13 duration13 of13 dredging13 activities13 at13 the13 site13 13 The13 evaluation13 of13 long-shy‐term13 effectiveness13 and13 permanence13 should13 consider13 the13 uncertainty13 in13 long-shy‐term13 projections13 of13 risk13 reduction13 and13 consider13 the13 effect13 of13 robust13 cleanup13 actions13 that13 result13 in13 a13 rapid13 decrease13 in13 contaminant13 concentrations13 on13 the13 uncertainty13 in13 the13 long-shy‐term13 risk13 reduction13 predictions13 13 Alternatives13 that13 permanently13 remove13 or13 isolate13 more13 contamination13 should13 receive13 a13 higher13 score13 than13 alternatives13 that13 are13 projected13 to13 reduce13 contaminant13 levels13 through13 uncertain13 natural13 recovery13 processes13 that13 are13 estimated13 using13 contaminant13 fate13 and13 transport13 models

General Comparison13 of13 alternatives13

component13 of13 many13 of13 the13 i13 alternatives13 no13 specific13 pilot13 work13 has13 been13 proposed13 and13 detailed13 information13 to13 support13 selection13 of13 this13 technology13 is13 lacking13 13 13

General In13 describing13 the13 process13 options13 and13 analyzing13 the13 alternatives13 there13 is13 no13 reason13 to13 lump13 enhanced13 MNR13 (EMNR)13 and13 in13 situ13 treatment13 (meaning13 carbon13 amendment)13 together13 as13 these13 methods13 can13 and13 likely13 will13 be13 done13 independently13 of13 each13 other13

Section13 2213 -shy‐13 Chemical13 System13 page13 2-shy‐6

The13 FS13 focuses13 on13 four13 COCs13 (ie13 Bounding13 Chemicals)13 amp13 benthic13 toxicity

alternative13 adequately13 addresses13 other13 chemicals13 to13 evaluate13 if13 unacceptable13 levels13 of13 other13 contaminants13 remain13 13 13 Risks13 to13 the13 benthic13 community13 as13 estimated13 through13

Section13 54213 -shy‐13 Physical13 Feature13 Sub13 SMA13 Types13 Table13 54-shy‐1

The13 physical13 features13 presented13 in13 Table13 54-shy‐113 should13 be13 expanded13 to13 include13 areas13 of13 erosiondeposition13 debris13 areas13 areas13 targeted13 for13 future13 redevelopment13 habitat13 areas13 slope13 presence13 of13 underwater13 utilities13 presence13 of13 bedrock13 outcrops13 within13 the13 sediment13 bed13 hot13 spots13 and13 areas13 with13 principle13 threat13 material13 (eg13 NAPL)13 areas13 with13 active13 upland13 sources13 or13 where13 source13 control13 is13 required13 to13 prevent13 recontamination

Section13 7113 -shy‐13 Screening13 the13 Alternatives13 page13 7-shy‐1

It13 should13 be13 noted13 that13 Alternative13 G13 was13 screened13 out13 based13 on13 areacost13 and13 post13 remediation13 SWAC13 only13 13 The13 evaluation13 did13 not13 consider13 the13 various13 remedial13 technologies13 that13 would13 be13 brought13 to13 bear13 in13 the13 areas13 identified13 based13 on13 the13 most13 conservative13 RALs13 13 13 This13 point13 needs13 to13 be13 acknowledged

Section13 826113 -shy‐13 Short-shy‐Term13

MNR13 page13 8-shy‐32

The13 arithmetic13 for13 worker13 injuries13 needs13 to13 be13 checked13 since13 the13 number13 of13 hours13 is13 stated13 once13 as13 two13 hundred13 thousand13 and13 once13 as13 two13 hundred13 million13 13 Two13 hundred13 million13 worker13 hours13 does13 not13 seem13 plausible13 and13 is13 presumably13 a13 typographical13 error13 13 Also13 please13 explain13 how13 the13 number13 of13 work13 hours13 is13 derived13 (what13 assumptions13 were13 made13 about13 the13 number13 of13 personnel13 etc)13 13 Given13 the13 assumptions13 in13 Section13 7513 (working13 10513 days13 per13 year13 during13 the13 fish13 window13 1213 hoursday13 613 dayswk)13 20000013 worker13 hours13 per13 year13 implies13 about13 16013 construction13 workers13 all13 working13 overtime13 (or13 the13 equivalent13 of13 28613 fulltime13 workers)13 13 Is13 that13 what13 is13 envisioned

Section13 83113 -shy‐13 Overall13 Protection13

Alternative13 A13 page13 8-shy‐37

The13 discussion13 of13 the13 time13 to13 achieve13 RAOs13 for13 Alternative13 A13 should13 be13 described13 explicitly13 13 It13 should13 be13 noted13 that13 as13 documented13 on13 Figure13 822-shy‐113 that13 the13 RG13 for13 PCBs13 of13 3013 ugkg13 is13 not13 achieved13 for13 either13 the13 base13 case13 or13 lower13 bound13 scenario13

Section13 84113 -shy‐13

Overall13 Protection13 of13 Human13 Health13 and13 the13 Environment13 page13 8-shy‐41

The13 discussion13 states13 that13 Alternatives13 B-shy‐i13 and13 B-shy‐r13 are13 both13 projected13 to13 achieve13 long-shy‐term13 PCB13 smallmouth13 bass13 whole13 body13 tissue13 contaminant13 concentrations13 that13 are13 at13 or13 below13 the13 most13 conservative13 estimates13 of13 acceptable13 risk13 levels13 13 However13 the13 discussion13 does13 not13 acknowledge13 the13 uncertainty13 in13 these13 projections

Section13 913 -shy‐13 Comparative13 Analysis13 of13 Risk13 pages13 9-shy‐113 and13 9-shy‐5

The13 information13 presented13 in13 Section13 913 does13 not13 provide13 a13 sufficiently13 detailed13 comparative13 risk13 analysis13 to13 support13 remedial13 decision13 making13 13 This13 is13 a13 major13 shortcoming13 that13 permeates13 the13 FS13 13 For13 example13 detailed13 information13 is13 presented13 in13 Section13 613 regarding13 the13 expected13 effectiveness13 of13 remedial13 technologies13 based13 on13 site13 specific13 information13 13 However13 13 the13 information13 presented13 in13 Section13 713 does13 not13 describe13 how13 that13 analysis13 is13 applied13 within13 the13 various13 AOPCs13 to13 develop13 the13 remedial13 action13 alternatives13 13 Similarly13 a13 lot13 of13 information13 is13 presented13 in13 Section13 813 about13 the13 tools13 for13 performing13 the13 detailed13 evaluation13 of13 alternatives13 but13 the13

achieve13 the13 RAO13 and13 that13 all13 short13 term13 impacts13 are13 expected13 to13 be13 over13 small13 areas13 and13 time13 periods13 the13 comparative13 analysis13 of13 alternatives13 comes13 down13 to13 cost13 and13 certainty13 in13 achieving13 the13 RAO13 over13 some13 time13 period

Table13 90-shy‐113 does13 not13 provide13 sufficient13 detail13 with13 which13 to13 select13 a13 remedial13 action13 alternative13 13 Except13 for13 the13 no-shy‐action13 alternative13 much13 of13 the13 information13 presented13 (with13 the13 exception13 of13 cost13 area13 CO213 emissions13 etc)13 does13 not13 change13 until13 Alternatives13 E13 and13 F13 which13 are13 expected13 to13 have13 greater13 construction13 water13 quality13 impacts13 and13 an13 increased13 potential13 for13 habitat13 restoration13 integration13 conflicts13 13 For13 example13 the13 ability13 to13 meet13 RAOs13 is13 either13 yes13 or13 uncertain13 for13 all13 alternatives13 and13 the13 time13 to13

meet13 RAOs13 and13 the13 time13 until13 RAOs13 are13 achieved

Section13 91113 -shy‐13 Surface13 Sediment13 RAOs13 page13 9-shy‐3 this13 assertion13 or13 modify13 the13 assertion

Section13 95713 -shy‐13 Potential13 Impacts13 to13 Workers13 page13 9-shy‐32

This13 analysis13 is13 flawed13 in13 that13 if13 the13 workers13 were13 not13 working13 on13 the13 remediation13 of13 the13 Portland13 Harbor13 site13 they13 would13 be13 working13 on13 remedial13 or13 construction13 work13 elsewhere13 with13 presumably13 similar13 impacts13 to13 workers13 13 As13 a13 result13 the13 results13 of13 this13 analysis13 should13 not13 be13 factored13 into13 remedial13 decision13 making

90a Uncertainty13 and13 Sensitivity13 Evaluations

Appendix13 E Sensitivity13 Analysis13 (human13 health)13 -shy‐13 The13 text13 in13 Appendix13 E13 is13 written13 to13 give13 the13 erroneous13 impression13 that13 the13 sensitivity13 analysis13 was13 either13 required13 by13 EPA13 guidance13 13 13 However13 the13 sensitivity13 analysis13 in13 the13 draft13 FS13 is13 not13 consistent13 with13 EPA13 guidance13 A13 detailed13 discussion13 of13

uncertainties13 associated13 with13 the13 exposure13 values13 used13 in13 the13 BHHRA13 is13 already13 presented13 in13 the13 BHHRA13 including13 a13 quantitative13 estimate13 of13 the13 magnitude13 of13 the13 uncertainties13 on13 the13 overall13 risk13 estimates13 13 Further13 inconsistent13 with13 EPA13 guidance13 that13 the13 LWG13 cites13 to13 in13 this13 appendix13 no13 work13 plan13 was13 submitted13 to13 EPA13 for13 review13 and13 concurrence13 and13 the13 probabilistic13 reanalysis13 of13 the13 exposure13 assessment13 presented13 here13 blatantly13 ignores13 the13 recommendation13 in13 Section13 5213 of13 RAGS13 Volume13 III13 that13

Contrary13 to13 the13 semantics13 employed13 in13 the13 draft13 FS13 and13 in13 Appendix13 E13 there13 does13 not13 appear13 to13 be13 any13 true13 sensitivity13 analysis13 conducted13 13 By13 definition13 a13 sensitivity13 analysis13 should13 not13 change13 the13 outcome13 of13 the13 analysis13 13 Rather13 it13 should13 indicate13 how13 the13 outcome13 of13 an13 analysis13 responds13 to13 perturbations13 to13 specific13 inputs13 13 In13 contrast13 consistent13 with13 the13 statement13 in13 Section13 213 of13 the13 draft13 FS13 that13 using13 equally13 valid13 assumptions13 in13 the13 risk13 assessment13 could13 have13 resulted13 in13 different13 PRGs13 and13 eventually13

13 analysis13 presented13 here13 appears13 to13 be13 nothing13 more13 than13 a13 thinly13 veiled13 effort13 to13 circumvent13 the13 exposure13 assumptions13 used13 in13 the13 BHHRA13 and13 replace13

protective13 of13 human13 health13 is13 premised13 on13 two13 fundamental13 errors13 13

The13 LWG13 has13 mischaracterizedmisinterpreted13 the13 fish13 consumption13 rates13 as13 used13 in13 the13 BHHRA13 of13 17513 gday13 and13 14213 gday13 as13 upper13 percentiles13 (90th13 and13 99th)13 for13 consumers13 of13 fish13 13 EPA13 used13 these13 values13 from13 national13 upper13 percentiles13 of13 consumers13 and13 non-shy‐consumers13 of13 fish13 to13 represent13 average13 consumption13 rates13 for13 actual13 consumers13 of13 fish13 13 By13 definition13 we13 are13 not13 interested13 in13 the13 risks13 of13 consuming13 fish13 to13 people13 who13 do13 not13 consume13 fish13 13 As13 acknowledged13 in13 the13 BHHRA13 the13 associated13 90th13 and13 99th13 percentile13 consumption13 rates13 for13 those13 individuals13 who13 do13 regularly13 consume13 fish13 are13 20013 gday13 and13 50413 gday13 respectively13 13 Use13 of13 the13 combined13 consumernon-shy‐consumer13 data13 was13 premised13 on13 the13 assumption13 that13 actual13 consumption13 rates13 of13 resident13 fish13 obtained13 from13 Portland13 Harbor13 itself13 rather13 than13 alternate13 sources13 was13 likely13 within13 the13 range13 of13 values13 encompassed13 between13 the13 respective13 90th13 and13 99th13 percentile13 rates13 particularly13 since13 fishing13 rates13 in13 the13 area13 are13 suppressed13 due13 to13 existing13 fish13 advisories

90b Uncertainty13 and13 Sensitivity13 Evaluations

Appendix13 E (Continued13 from13 Comment13 90a)

This13 mischaracterization13 of13 consumption13 rates13 as13 upper13 percentiles13 for13 fish13 consumers13 instead13 of13 median13 values13 has13 profound13 implications13 in13 the13 analysis13 In13 a13 probabilistic13 evaluation13 about13 one13 half13 of13 the13 values13 are13 expected13 to13 be13 above13 the13 50th13 percentile13 and13 one13 half13 of13 the13 values13 below13 the13 50th13 percentile13 In13 fact13 if13 fish13

rates)13 and13 there13 is13 the13 potential13 for13 consumption13 rates13 much13 higher13 than13 the13 median13 rate13 By13 definition13 there13 are13 no13 013 gday13 rates13 for13 fish13 consumers13 and13 it13 is13 likely13 that13 the13 fish13 consumption13 rate13 is13 skewed13 to13 the13 right13 13 In13 addition13 the13 reanalysis13 of13 PRGs13 cannot13 be13 considered13 protective13 of13 human13 health13 in13 that13 it13 fails13 to13 consider13 the13 higher13 consumption13 rates13 associated13 with13 subsistence13 and13 tribal13 fishers13 or13 consider13 calculating13 PRGsRGs13 based13 on13 infant13 exposure13 to13 persistent13 organic13 pollutants13 via13 breast13 milk13 13 Given13 that13 infants13 are13 both13 subject13 to13 the13 greatest13 exposure13 to13 bioaccumulative13 contaminants13 such13 as13 PCBs13 and13 are13 also13 most13 sensitive13 to13 their13 adverse13 health13 effects13 RGs13 calculated13 to13 be13 protective13 only13 of13 adult13 consumers13 of13 fish13 cannot13 be13 considered13 protective13 of13 infant13 exposure

conditions13 might13 already13 meet13 the13 Comprehensive13 Environmental13 Response13 Compensation13 and13 Liability13 Act13 (CERCLA)13 threshold13 criterion13 for13 overall13 protection13 of13 human13

Appendix13 E13 Attachment13 1A13 Ecological13 RG13 13 The13 sensitivity13 analysis13 of13 the13 PCB13 RG13 and13 BERA13 assumptions13 about13 exposure13 toxicity13 were13 examined13 using13 input13 parameters13 that13 were13 not13 a13 part13 of13 the13 BERA13 13 For13 example13 the13 risk13 model13 was13 completely13 different13 including13 a13 new13 terrestrial13 prey13 component13 for13 the13 mink13 diet13

Appendix13 E13 contains13 a13 flawed13 analysis13 that13 if13 done13 correctly13 would13 refute13 the13 above13 statements13 The13 appendix13 is13 essentially13 a13 probabilistic13 risk13 assessment13 that13 was13 conducted13 without13 involvement13 of13 EPA13 and13 the13 other13 agencies13 and13 which13 is13 fundamentally13 flawed13 13 13 At13 the13 FS13 meeting13 in13 June13 201113 when13 the13 sensitivity13 analysis13 was13 first13 presented13 EPA13 instructed13 the13 LWG13 to13 not13 include13 the13 analysis13 in13 the13 FS13 because13 it13 was13 in13 effect13 a13 separate13 risk13 assessment13 which13 is13 inconsistent13 with13 EPA13 guidance13 13

EPA13 rejects13 the13 sensitivity13 analysis13 because13 the13 risk13 model13 differs13 from13 the13 risk13 model13 presented13 in13 the13 baseline13 risk13 assessment13 it13 is13 flawed13 and13 because13 it13 is13 not13 necessary13 for13 remedial13 decision13 making

91 Uncertainty13 and13 Sensitivity13 Evaluations

Section13 10213 -shy‐13 Risk13 13 Management13 Decisions13 and13 Uncertainties13 page13 10-shy‐8

Use13 of13 uncertainty13 and13 sensitivity13 evaluations13 13

uncertainty13 analysis13 (Appendix13 U13 Section13 5)13 This13 evaluation13 indicated13 that13 the13 natural13 recovery13 and13 modeling13 uncertainties13 are13 small13 compared13 to13 the13 RG13 and13 SMA13

depicting13 environmental13 conditions13 it13 represents13 the13 variation13 seen13 in13 model13 results13 when13 a13 few13 select13 parameters13 are13 varied13 13 Subsequent13 comparisons13 to13 the13 range13 of13 potential13 remedial13 goals13 and13 the13 assertion13 that13 the13 comparisons13 have13 meaning13 are13 not13 appropriate13

The13 FS13 should13 include13 a13 more13 robust13 evaluation13 of13 the13 uncertainty13 of13 MNR13 to13 achieve13 RAOs13 at13 the13 Portland13 Harbor13 Site13 Delete13 references13 to13 risk13 management13 (ie13 Sections13 10113 and13 10213 and13 associated13 Appendices)13 as13 being13 beyond13 the13 scope13 of13 the13 FS

General Infant13 exposure13 pathway13 -shy‐13 The13 infant13 breastfeeding13 pathway13 for13 PCBs13 was13 shown13 in13 the13 human13 health13 risk13 assessment13 to13 be13 a13 critical13 exposure13 pathway13 This13 is13 inconsistently13 addressed13 in13 the13 FS13 (for13 example13 Executive13 Summary13 Figure13 313 Section13 26413 page13 2-shy‐4513 second13 to13 last13 paragraph13 Appendix13 E)13 13 In13 addition13 it13 is13 inconsistently13 addressed13 in13 the13 Risk13 Management13 document13 In13 Table13 2-shy‐113 of13 the13 risk13 management13 document13 the13 infant13 exposure13 pathway13 is13 not13 recommended13 for13 consideration13 in13 the13 FS13 even13 though13 this13 is13 the13 most13 important13 pathway13 for13 PCB13 exposure13 In13 both13 documents13 the13 hazard13 index13 of13 6000013 for13 the13 infant13 exposure13 pathway13 is13 sometimes13 omitted13 when13 the13 maximum13 hazard13 index13 is13 discussed13 The13 sensitivity13 analysis13 in13 Appendix13 E13 of13 the13 FS13 does13 not13 include13 this13 important13 pathway13 Valid13 decisions13 about13 the13 effectiveness13 of13 remedial13 alternatives13 cannot13 be13 made13 without13 considering13 risks13 to13 infants

Appendix13 Ha13 Section13 412313 page13 65

Sensitivity13 analysis13 found13 that13 the13 model13 was13 not13 very13 sensitive13 to13 the13 magnitude13 of13 National13 Pollutant13 Discharge13 Elimination13 System13 (NPDES)13 loadings13 with13 exceptions13 in13 the13 immediate13 vicinity13 of13 the13 discharge13 locations13 13 Thus13 in13 most13 cases13 the13 model13 predictions13 can13 be13 used13 but13 if13 MNR13 is13 proposed13 at13 or13 near13 NPDES13 discharge13 for13 copper13 or13 BaP13 then13 the13 use13 of13 this13 sensitivity13 run13 must13 be13 evaluated13 13 (This13 applies13 to13 Section13 6221313 evaluating13 the13 likelihood13 of13 success13 of13 MNR)

94 Cost13 Estimates

Appendix13 K Review13 of13 the13 cost13 estimate13 identified13 some13 items13 that13 appear13 to13 have13 elevated13 costs13 based13 on13 general13 experience

basis13 to13 build13 up13 to13 the13 mobde-shy‐mob13 costs13 indicating13 what13 was13 included

Documentation13 should13 be13 provided13 showing13 the13 basis13 for13 the13 assumptions13 for13 the13 items13 listed13 above

95a Cost13 Estimates

Appendix13 K Review13 of13 the13 cost13 estimate13 also13 identified13 a13 number13 of13 questions13

General13 Liability13 Please13 identify13 these13 indirect13 costs

95b Cost13 Estimates

Appendix13 K (Continuation13 of13 Comment13 95a)

full13 unit13 trains13 on13 site13 to13 avoid13 running13 out13 of13 stockpile13 room

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non-shy‐discount13 and13 the13 discount13 after13 the13 factors13 are13 applied13

96 Editorial Section13 2113 -shy‐13 Physical13 System13 page13 2-shy‐2 a13 range13 of13 species13 including13 special13 status13 species13 such13 as13 salmon13 and13 Bald13 Eagles13 and13 that13 the13 river13 experiences13 frequent13 recreational13 uses13 including13 boating13 and13 fishing13 13 13

The13 FS13 should13 acknowledge13 the13 ecological13 and13 recreational13 functions13 of13 the13 river

EPA Feasibility Study Comments Letter

Detailed Comments Table

cooperatively with the L WG in completing the FS and expects that revisions to the FS by both parties will be shared for review and comment as they are developed in order to proceed in an iterative manner

EPA will only be providing detailed comments on the portions of the draft FS that we will require the LWG to revise or perform more analysis General areas of concern on the draft FS are therefore noted in this letter and the attached comments but specific requests to LWG will be provided under separate c_over throughout the revision process In keeping with the shared goal of completing this document in a timely manner we will work with the L WG to develop a process and schedule for revising this document that targets November 2013 as a completion date for the FS

Key areas of concern identified by EPA and its partners include the following

Text Figures and Presentation There are many instances where the text is confusing and key information is not presented in a clear and usable manner For example the scale used in some figures (eg Appendix Fa figures that present the River Mile SWAC vs Area Remediated results for time T=O) makes it difficult to differentiate between the alternatives In other cases the assumptions used in some of the evaluations are not clearly stated in the document There is also too much advocacy in some sections of the report that obscures the straightforward presentation of information Please note that our lack of detailed comments on the text and figures in this initial comment set should not be construed to imply that we are in agreement with the text EPA expects to work with LWG to revise figures and text in the document to correct these problems

Fate and Transport Modeling and MNR EPA has identified many concerns related to the MNR modeling and conclusions and has provided more detail in the attached comments The US Army Corps Engineer Research and Development Lab recently performed independent model runs linking deposition to hydrodynamics Based on the Corps modeling runs it appears there is sufficient uncertainty in the LWG model results to conclude that the long-term projections provided in the draft FS do not accurately predict depositional rates for many areas in the lower Willamette River that are of concern for this remedial action

Since we have the Corps model results EPA at this point intends to use the empirical and both the Corps and AnchorQEA modeled results to support the evaluation of alternatives middot rather than request revision of the Anchor QEA model runs to address specific concerns

Principal Threat Waste and Hot Spots EPA does not agree with the results of the analysis that L WG has provided which ultimately a yo ids designating any sediment at the site as Principal Threat Waste (PTW) as defined by EPA guidance or Hot Spots as defined by the State of Oregon a The overall intent of EPAs guidance and Oregons regulations is to ensure that there is a preference

a ORS 465315(2)(b)(A) and OAR 340-122-0115(32)(b)

Enclosure

Mr Rob Neely NOAA

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Documents

EPA Comments: Portland Harbor Superfund Site Feasibility Study