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EPA Region 6 Records Ctr.

269287

April 18,2005

VIA ELECTRONIC AND OVERNIGHT MAIL

Gwendolyn MassenburgRemedial Project ManagerU.S. EPA, Region V (SR-6J)77 West Jackson Blvd.Chicago, IL 60604-3590

D

lit APR 2 1 2005

REMEDIAL RESPONSE BR. 2

Re: CRS Site Remedial Investigation/Feasibility StudyDraft Feasibility Study Submission

Dear Ms. Massenburg:,he Cîca, Recovery

On bena,f of ,he CRS SHe Group, , «-£*£• wîs

Îg a^vl^d DeraCfl R^S on Augus,'., 2005. We have highHgh.ed in gray the hems ,hat we hope

to discuss during your site visit on Wednesday, April 20, 2005.

number above.

lv>tG-illiamsp Chairperson

Copy^Thomas Nash, Associate Regional Counsel, U.S. EPA (w/o enclosure)Lawrence Antonelli, Ohio EPA (w/enclosure)Larry R. Mencin, CRS Technical Committee Chairperson (w/enclosure)

Chemical Recovery Systems, Inc.Response to EPA's Comments to Rl/FS Report

Revision: 0April 2005

Page 1 of40

DRAFTRESPONSES TO COMMENTS TO THE DRAFT RI REPORT

(REVISION 0, OCTOBER 2004)CHEMICAL RECOVERY SYSTEMS INC.

General Comments

Since the surface runoff was identified as one of the primary means of contaminant migration,the river bank appears to be a likely location of surface soil contamination. For now, only twosoil samples (HA- 4 and HA-5) were taken on the bank on the west side of the Site, headingdown to the river. These sample locations were in close proximity to each other at the south endof the bank. Therefore, it is not feasible to make a determination regarding the river bank fromthese two sampling points. This area needs to be fully evaluated to determine if it must beremediated, and the results of the evaluation included in the RI Report.

Response: Additional surface soil samples (up to three) will be collected along the bank of theriver and analyzed for the specific chemicals of concerns (COC). However, it must be notedthat in some cases, soil samples can not be collected along the bank as there is no soil present(bedrock outcrops). In addition, locations with soil may not be sampled due to health andsafety concerns associated with the steep bank slope.

Specific Comments

2.0 STUDY AREA INVESTIGATION

1. Section 2.1.1.1, paragraph 1, page 6 of 29: The draft report reads that a total of 40 soilborings was advanced at the site using direct push technology. Additionally, five surfacesoils borings were also collected from the top of the river bank using a hand auger. Thesample designations were HA01 - HA05. In Section 4.0 (Nature and Extent of Impact) itis stated that a total of fifty soil borings was installed at the site for soil and ground watercharacterization. For consistency, it should be stated in Section 2 that an additional fivesoil borings were installed during phase II of the investigation, which evaluated the sewerline. It is confusing to read in Section 2 that 40 total soil borings were advanced duringthe investigation, and in Section 4 it reads that 50 total borings were installed for soil andground water sampling. Please check and correct to have the numbers agree in thosesections.

Response: A total of 50 soil sampling locations were advanced (GP-1 through GP-45 - direct

::ODMA\PCDOCS\CLEVELAND\695127\1

Chemical Recovery Systems, Inc.Response to EPA's Comments to RI/FS Report


Page 2 of40

push or auger, and HA-1 through HA-5 - hand auger). The report will be amended to clarifythe text.

2. Section 2.1.1.2, page 8 of 29: This section reads that only temporary monitoring wellGP-16 had sufficient groundwater for analyses besides VOC. It then reads that MonitoredNatural Attenuation (MNA) parameters were collected at each monitoring well. Thisstatement is contradictory and must be clarified.

Response: The text will be amended to clarify that only temporary monitoring point GP-16had sufficient groundwater for analysis besides VOCs and that Monitored NaturalAttenuation parameters were collect at each permanent monitoring welL

3. The document does not mention or specify in the report the fate of the temporarymonitoring wells. These points should be properly abandoned, if they are not to be usedin any additional site characterization activities. It was stated on the bottom of page 7,that all borings not completed as temporary monitoring wells were abandoned withbentonite plugs; however, it was not specified how the temporary wells that did not aid inthe site characterization due to insufficient water were managed. There were a total ofeight temporary monitoring wells installed at the site as part of the RI field work. Ofthese eight locations, only three yielded sufficient ground water for sampling (GP6,GP14, and GP16). The current status of the five "dry" wells must be clarified in thereport. Appendix A shows that the borings of GP2, GP9, GP19, GP26, and GP37 weregrouted this should also be stated in the report.

Response: All temporary monitoring points remain in the ground at the site. The boring logsfor GP-2, GP-9, GP-19, GP-26 and GP-37 will be amended. All temporary monitoring pointswill be properly abandoned once site characterization activities are complete.

4. Section 2.1.1.4, page 9 of 29: Detailed data from the storm sewer survey should beprovided in the RI Report, possibly as an appendix. Locations of the sewer pipeperforations and other problems should be identifiable for future reference.

Response: Copies of the storm sewer video have been forwarded to the regulatory agencies.The text will be amended to add a discussion concerning the results from storm sewer videoactivities.

5. Section 2.1.1.4, page 9 of 29: It is stated that the storm sewer is above the ground waterlevel, however it was noted that the last 30 to 35 feet of the sewer was submerged. Atwhat end of the storm sewer was the pipe submerged? Was this due to groundwater? Thisitem should be clarified in the RI Report.

Response: The text will be amended to clarify that the last 30 to 35 feet of the storm sewer onthe river bank is full of water due to the broken pipe and headwalL




Page 3 of40

4.0 NATURE AND EXTENT OF IMPACT

1. Section 4.2, page 16 of 29,4th paragraph: The widespread detection of arsenicthroughout the unconsolidated material at the site would seem to indicate that this may benaturally occurring. Background levels of arsenic in the area should be determined andreported. If the arsenic site levels are found to be naturally occurring, and it is determinedthat remediation of arsenic is not required, remediation alternatives would become at leastviable after PCB issues were addressed, since the COCs would be limited to SVOCs andVOCs.

Response: The entire peninsula has been backfilled with various materials over the past 100plus years. In addition, industrial operations have dominated the peninsula for the last 100plus yean. There is very little chance that true background samples can be collected, however,this item can be discussed in detail during the site meeting on 20 April 2005.

2. Section 4.3, page 17 of 29,3rd paragraph: Natural attenuation (NA) parameters wereonly evaluated at one well, the most impacted well, MW-6. Results from this one wellwere used to draw a conclusion that conditions at the site are favorable for NA. If the RIreport remain as presently written, additional data must be collected and or evaluated tostate that NA is occurring.

Response: For clarification, natural attenuation parameters were collected from allpermanent monitoring wells. Due to the lack of significant impacts in all permanentmonitoring wells with the exception of MW-6, the discussion concerning natural attenuationfocused on MW-6. The report will be amended to reflect this response. In addition the reportwill be expanded to include additional text concerning NA of VOCs in groundwater.

3. A more specific explanation is needed of how dissolved oxygen concentrations, ferrousiron concentrations and oxidation/reduction values in ground water at the site arefavorable for NA, other than the presence of apparent daughter and breakdown products.It is also generally stated in Section 5.2 that conditions in ground water at the site arefavorable to NA for VOCs and SVOCs, more specific information is needed here also.

Response: Section 4.3 will be amended to provide additional explanation relating howdissolved oxygen, ferrous iron and oxidation reduction potential are favorable to naturalattenuation.

4. Based on the data collected thus far, it appears that VOC concentrations seems todecrease with depth at the site in the unconsolidated material, and concentrations ingroundwater also appear to decrease generally from east to west across the site. It wasstated in Section 5.3 (Contaminant Migration) that with the above, and the absence ofVOCs in surface water and sediments, it suggested that there is limited impact from the

: :ODMA\PCDOCS\CLEVELAND\695127\1



Page 4 of40

soil to the groundwater pathway. It is clear that there has been an impact to ground waterfrom site soils. Processes of dilution and volatilization are acting as significantcontributors to the lack of VOCs detected in the surface water and sediments to the site.

Response: Section 5.3 indicates that VOCs were detected in soil and groundwater. There isno mention that soils did not impact groundwater, but rather soil and groundwater VOCimpacts are most likely limited to the site. Dilution, volatilization, as well as other physicaland/or mechanical processes may all be contributing to the lack of VOCs in surface water andsediments.

5.0 FATE AND TRANSPORT

1. Section 5.2, paragraph 3, page 20 of 29: The draft report reads VOCs may degrade inthe environment. Biodegradation by soil microorganisms can be an important processaffecting the concentrations of VOCs in soils, sediment, and water. Conditions at the Siteare favorable for degradation. Is this statement based on the results of NA parametersfrom only MW-6? Information from one well generally is not representative of the entiresite. Please clarify.

Response: MW-6 is the only significantly impacted permanent welL The impactedgroundwater has not significantly migrated from MW-6 to any of the down-gradientmonitoring wells, which lends credence to natural attenuation at the site. The last sentencewill be changed to "The groundwater VOC analytical results indicated that conditions at theSite are favorable for degradation ".

2. Section 5.2, paragraph 5, page 20 of 29: In discussing the SVOCs at the site in thisparagraph, the statement is made that "Conditions at the Site are favorable fordegradation." Section 4.3 interprets the results of analyzed NA parameters for chlorinatedVOCs, but there is no discussion of SVOC degradation. How has this conclusion beenreached for SVOCs?

Response: MW-6 is the only significantly impacted permanent well. The impactedgroundwater has not significantly migrated from MW-6 to any of the down-gradientmonitoring wells, which lends credence to natural attenuation at the site. In addition,SVOCs in groundwater degrade, albeit slower than VOCs. However, there appears tobe an absence of data which can be used to definitively indicate that SVOCs aredegrading in groundwater at the site. The section will be amended to reflect thisresponse.

6.0 RISK ASSESSMENT

1. Section 6.1, paragraph 2, page 24 of 29: The draft report reads: To insure the




Page 5 of40

cumulative risk of 10"6 and hazard level of 1,10% of the PRGs were ... This languageshould be changed to read: To ensure the cumulative risk of 10"6 cancer risk or less, and ahazard index of 1.0 or less, PRGs were used for comparison. If the maximumconcentration of a chemical detected at the site, for any specific media, exceeds or isequal to 10"6 cancer risk, or exceeds or is equal to a hazard quotient of 0.1, the chemical isconsidered a COC.

Response: Agree. The sentence will be changed as suggested.

2. The Agency has a regional memorandum for identifying and selecting COCs atSuperfund Sites. The Agency mentioned this memo in previous comments to the workplan. The memo provided was dated November 22,2002, which should have been usedfor this purpose. It is unclear what is meant by 10% of PRO were used for comparison.

Response: The 10% PRG approach is consistent with what was stated in the November 22,2002 regional memorandum to include cumulative effects by assuming that siteconcentrations that are less than 10% of the PRG will not contribute cumulative risk to withinone significant digit.

3. Section 6.1, paragraph 3,2nd sentence, page 24 of 29: "The anticipated future use ofthe site is to remain commercial and industrial." If this is so, some form of institutionalcontrol (ICs) is required for this site to ensure that it will not be converted to residentialuse, some day down the road. This is so, even if a remediation takes place based onindustrial/commercial use. Therefore, unless ICs are put in place the remediation wouldhave to be based on residential use.

Response: Agree. As stated in the comment response to Memorandum on Remedial ActionObjectives dated July 2004, the only reasonable future use of the site is commercial/industrialbased on the historical industrial use of the site and the active industrial use of allsurrounding land. The access road (Locust Street) is currently the truck access for EngelhardChemical Company, which makes the site unsuitable for development as a park. City ofElyria Planning Department indicated that the future planning for the site will becommercial/industrial. In addition, a deed restriction is intended to be obtained from theowner and recorded to prevent any future residential use of the property. Therefore, non-industrial scenarios were not evaluated in the RI report. However, a residential scenario willbe evaluated as a potential future use in the revised RI report.

4. Section 6.1, paragraph 3,5th sentence, page 24 of 29: "The potential exposurepathways evaluated ..." This sentence should be changed to read: The potentialexposure pathways evaluated for the site include soil ingestion, soil dermal contact, theinhalation of soil volatile chemicals to indoor and outdoor air, the inhalation ofgroundwater volatile chemicals to indoor and outdoor air, and groundwater dermalcontact.

: :ODMA\PCDOCS\CLE VELAND\695127\ 1

Response: Agree. The sentence will be amended.



Page 6 of40

5. Soil volatile chemicals to indoors were evaluated using the U.S. EPA 1996 model. Themore recent vapor intrusion modeling and guidance should be used for this purpose, morespecifically, EPA OSWER Draft Guidance for Evaluating the Vapor Intrusion to IndoorAir Pathway from Groundwater and soils (Subsurface Vapor Intrusion Guidance)(Complete Document) visit: http://www.epa.gov/correctiveaction/eis/vapor.htm.

Response: The U.S. EPA 1996 model was used for the soil volatile chemicals to outdoor airnot the soil volatile chemicals to indoor air. The ASTM model was used to evaluate soil toindoor air pathway. The ASTM model is based on the Johnson and Ettinger model; however,the ASTM model does not include advection. The ASTM model was selected based on thefollowing: 1) a previous study performed by Parsons shows that the modeled concentrationsusing ASTM model were within an order of magnitude of the monitored indoor airconcentrations without indoor/outdoor sources (Parsons, 2000. Baseline Risk AssessmentReport for Areas West of460-489 Harbor Boulevard in the Vicinity of 511 O'Neil AvenueBelmont, California); and 2) ASTM model is an approved model for other regulatoryprograms. For the potential future residential scenario, the current US EPA's Indoor AirModel will be used for comparison purposes in the revised RI report.

6. %ndSection 6.1, paragraph 5, 2 sentence, page 24 of 29: Risk numbers are given for soilexposures only. Since groundwater volatile chemicals and dermal contact pathways werealso evaluated, why are they excluded from the summary?

Response: The total cancer risk and total hazard index calculated for a future commercialworker and a future construction worker do include groundwater exposure pathways.Therefore, the 1st sentence of the 1st bullet of paragraph 5 will be changed to "The totalcancer risk and total hazard index resulting from exposure to COPCs in soil and groundwaterfor a future commercial worker were calculated to be 3 x Iff4 and 23, respectively." The 1stsentence of 2nd bullet of paragraph 5 will be changed to "The total cancer risk and totalhazard index resulting from exposure to COPCs in soil and groundwater for a futureconstruction worker were calculated to be 2 x 10~5 and 3.5, respectively".

7. Section 6.1, paragraph 6,1st sentence, page 25 of 29: The sentence should be changedto read: Based on the risk assessment results, the contaminants detected in soil pose apotential and unacceptable risk and hazard to human health under the futureindustrial/commercial and construction scenarios.


6.2 Environmental/Ecological Evaluation

1. Section 6.2, page 25 of 29: Based on this paragraph, a claim has been made that there is::ODMA\PCDOCS\CLEVELAND\695127\1



Page 7 of40

no wildlife because the habitat is unsuitable (i.e., an absence of evidence is evidence ofabsence). This is not an argument that can be safely made during a Screening LevelEcological Risk Assessment, especially without adequate characterization of the site. Theeffects of anthropogenic physical stressors (dams, industrialization) are less-wellcharacterized, and potentially less-pronounced, for the aquatic community than theterrestrial community. While dams, industrial land -use, and a poor riverbank habitatMAY indeed reduce the potential for both aquatic and terrestrial wildlife use of the site(and hence exposure), it is not necessarily the case. The adverse effects on wildlife maybe the result of high levels of chemical contamination, in addition to physical stressors; orthe chemicals may be the primary stressors at the site.

Response: The statement made in this paragraph was not meant to imply that "there is nowildlife because the habitat is unsuitable". Instead, we were making the point that the siteis so heavily developed for industrial use, that there is very little natural habitat availablefor wildlife to use-especially when considering the terrestrial habitat. In essence, we werefollowing the guidance for evaluating contaminants in soils that is contained on pages 1-5and 1-6 of the ECO-SSL guidance (USEPA, 2003a) which states: "An exposure pathway isnot considered complete if natural habitat for ecological receptors is not present and is notexpected to be present in the future" and "Exposure pathways may not be consideredcomplete for ecological receptors if the site is within urban and/or industrialized areaswhere natural habitat and receptors are absent." An exception to this is if there is thepotential for protected species to use the site; however, this is not the case for CRS sincethe Ohio Department of Natural Resources confirmed that no endangered and/orthreatened species occur at or near CRS (refer to Appendix A of the SLERA).Furthermore, we disagree that the site has not been adequately characterized. In additionto the numerous site-specific studies that are detailed in Sections 1 through 3 of the RIreport, a number of other studies have been undertaken by an adjacent property owner(Engelhard Corporation) and by the Ohio EPA (of the Black River) that provide additionalinformation concerning the nature of the area. Therefore, the site and surrounding areahave been well characterized allowing us to make such a conclusion in the SLERA.However, we do agree that a summary of this additional supporting information would behelpful for a person reviewing this document; therefore, a summary of these studies and adetailed habitat map will be included in the revised SLERA to support this claim.

2. Dams may define and limit the source area for benthic invertebrates; however, the CRSSLERA does not specifically describe the distance from the site at which the dams arelocated. They may be sufficiently far away from the CRS site potentially to allow for anupstream source of benthic invertebrates, which may subsequently migrate to the CRSsite

Response: Additional detail of the dams and other sources of potential impact to aquatic life,specifically in the vicinity of CRS, will be provided in the revised report.




Page 8 of40

3. In addition, there are a number of inorganic and organic Contaminants of PotentialEcological Concern (COPECs) whose maximum concentrations exceed screeningbenchmark values (thus suggesting the possibility of ecological risk). These exceedencescontribute to the uncertainty over the claim that nearby dams is the limiting factors forviable and sustained benthic invertebrate communities. Please provide evidence thatsupports the claim that it is the darns, and other physical stressors, or whether, it is thechemical stressors that are impacting the benthic communities.

Response: Agree; see also response to comment #2 above regarding the additionalinformation that will be provided in the revised SLERA concerning the dams in the BlackRiver and other potential physical stressors.

4. The Soil Preliminary Remediation Goals that were used to screen out COPECs should bereplaced with the Ecological Soil Screening Levels (Eco-SSLs; EPA 2003a), whereavailable, and the revised Region 5 RCRA Ecological Screening Levels (ESLs; EPA2003b). PRGs are generally not used at this stage in the Screening Level Ecological RiskAssessment (SLERA) process. While in some cases the PRGs are lower than the Eco-SSLs or Region 5 ESLs, it is still more appropriate to use the values from those twosources instead of the PRGs. Assuming complete exposure pathways exist for allreceptors from which there are Eco-SSLs, the lowest of several values should be used fora particular COPEC. For example, assuming that both soil invertebrates and smallmammals may be exposed to chemical contamination in the soil, the mammal Eco-SSLshould be used for barium.

Table 1. Comparison of PRGs and Eco-SSLs (where available); units for all values: mg/kg

COPEC

AntimonyBarium

BerylliumCadmium

CobaltLead

Dieldrin

PRO

5 (plant)283

(woodcock)10 (plant)4 (plant,

woodcock)20 (plant)

40.5(woodcock)

n.a.

Eco-SSL (soilinvertebrates)

78330

40140

1700

Eco-SSL(plants)

32

110

Eco-SSL(birds)

1.0

19016

0.0016

Eco-SSL(mammals)

0.291000

360.38

24059

0.00028

Response: Agree; although we assume that the last statement of this comment is amisstatement and that actually the ECO-SSL for barium for soil invertebrates (330 mg/kg)would be used instead of the mammalian ECO-SSL (1000 mg/kg) since it is the lowest of the

: :ODMA\PCDOCS\CLE VELAND\695127\1

Chemical Recovery Systems, Inc.Response to EPA's Comments to RJ/FS Report


Page 9 of40

two available ECO-SSLsfor barium. Also, for compounds that lack both an ECO-SSL and aRegion 5 ESL, the soil PRG will be used as an alternative screening value.

5. It should be noted that aluminum toxicity is associated with soil pH and not totalaluminum (EPA 2003a). A soil pH of less than 5.5 indicates toxicity associated withaluminum. This information should be collected and presented.

Response: Agree; site-specific soilpH data will be collected. If the soilpH is greater than 5.5,aluminum will be removed as a compound of concern in soils.

6. The report incorrectly states that minimizing human health risk "should be adequatelyprotective for the ecological receptors that might inhabit such an urbanized environment."However, because effects' levels are different between ecological and human receptors,

it does not necessarily follow that ecological receptors will be protected at contaminantlevels that are protective of human health. Contaminant levels should be screened againstthe appropriate ecological screening values. If there are levels of COPECs that exceedno-effects levels (the level of contamination below which no adverse effects areexpected), then ecological receptors are potentially at risk, regardless if the contaminantlevels are below levels of human receptors.

Response: We agree that ecological effects may still occur even if the risk to human health isminimized; however, this statement was made to assist the risk managers when consideringthe current and planned future use of the site, which is industrial. In fact, for a lot of smallindustrial sites such as CRS, wildlife is actively discouraged from utilizing the site in order toprevent attracting unwanted vectors (nuisance birds, rodents and insects). Nevertheless, thetext will be revised to reflect that not all ecological receptors may be protected even if humanhealth risks are minimized.

7. Is there evidence that fish are only transient users of the site and not long-term users ofthe site? If fish are absent, is it because of lack of habitats or because of chemicalstressors? Evidence to support the claim that it is due to a lack of suitable habitats shouldbe provided.

Response: See also responses to comments #2 and #3 above regarding the supplementalinformation that will be provided in the revised SLERA concerning the Black River. Forinstance, the river frontage for the site is just over 400 feet and most of this frontage is verysteep and rocky. Thus, there is little suitable habitat available for fish species to nest and/orforage adjacent to the site. Additionally, one of the primary exposure pathways for fish isdirect contact with surface water; and based on the surface water screening results, surfacewater is not impacted at the site. Therefore, if fish are not present, it would appear to be morelikely due to the lack of suitable habitat versus chemical stressors.




Page I Oof 40

8. The fact remains that transient animal such as migratory birds may spend considerablelengths of time, especially during spring and summer in urban areas with poor qualityhabitats, not to mention urbanized animals, e.g., squirrels, domestic animals such as catsand dogs. Often these animals may have even greater exposures to chemicals comparedto humans simply because of their behavior, habits and greater potential contact withmedia such as soil and surface water. Therefore, potential risks to these animals cannotbe dismissed. Indeed, any remediation of the soils and/or water that occurs at this sitebased on commercial/industrial human exposures may still leave potential andunacceptable risk to these animal receptors.

Response: As stated previously in response to comment #1 above, there is very little naturalhabitat available at the site; therefore, most exposure pathways are not complete, especially fortransient animals that are associated with the terrestrial areas of the site. For example, theentire site is only 2.5 acres in size, and more than 75% of this area has been physically altered(buildings, paved, etc.). Additionally, when comparing what little site habitat there is tohabitats available on nearby properties, it is not evident that the CRS site has any areas thatwould be considered preferentially attractive to wildlife. Despite this fact, soils, surface waterand sediments were evaluated in this SLERA in order to determine the risk to all potentialreceptors coming into contact with these media—if even for only a brief period of time. Thescreening values used in the SLERA are based on chronic exposures for the most sensitiveplants and animals and they do not consider the amount of time spent by the receptor at a site(Le., the receptors are considered to spend their entire lives at the site). Therefore, thepotential risk to urban animals was not dismissed and is actually likely to be overestimated.Furthermore, we disagree that domesticated animals (Le., cats and dogs) should be consideredecological receptors as suggested in this comment. First, the site is and will be fenced.Second, domesticated animals should be leashed (the City ofElyria has a "leash law");therefore, these animals would not have access to the sue. Lastly, feral cats and dogs areconsidered to be nuisance and/or potentially dangerous animals, and would have to beremoved from the site as soon as they are discovered.

7.0 SUMMARY AND CONCLUSIONS

1. Section 7.1.3, 2nd paragraph, page 27 of 29: There is discrepancy with the informationpresented in this section versus that described in Section 6. Specifically, in Section 6 (1st

bullet, page 25 of 29), it is stated that the total cancer risk and Hazard Index (HI) fromexposure to COPC in soil for a future commercial worker was calculated to be SxlO"4 and23, respectively, However, in Section 7.1.3, these calculations for a future commercialworker were reportedly calculated to be 4x10^* and 10, respectively, for total cancer riskand HI. Clarify or correct.

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Page 11 of40

Response: Agree. The total cancer risk and hazard index for a future commercial workershould be consistent with the risk assessment results in Section 6. The sentence in Section 7will be changed accordingly.2. Section 7.1.3, 2nd paragraph, page 27 of 29: The COCs are not consistent in their

listing with Section 6. In Section 6 for a future commercial worker, the COCs were listedas arsenic, benzene, benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluroanthene,dibenzo(a,h)anthracene, tetrachloroethene (PCE), trichloroethene (TCE), and xylenesdetected in soil. However, in Section 7.1.3, the COCs listed for a future commercialworker are listed as Aroclor 1242, Aroclorl254, benzo(a)pyrene, TCE and PCE.

Response: Agree. The COCs should be consistent with the risk assessment results in Section6. The sentence will be changed accordingly.

3. The pathway of soil volatilization was also not mentioned in Section 7.1.3, but was listedin Section 6 for this scenario.

Response: Agree. The pathways of concern should be consistent with the risk assessmentresults in Section 6. The sentence will be changed accordingly.4. Similarly, for a future construction worker, the total cancer risk and HI described in

Section 6 of the report were listed as 2 x 10~5 and 3, respectively. In Section7.1.3 for thisexposure scenario, the total cancer risk and HI is listed as 4 x 10~5 and 8 respectively.The COCs for this scenario listed in Section 6 were listed as benzo(a)pyrene,dibenzo(a,h)anthracene, and TCE. However, in Section 7.1.3, the COCs for the futureconstruction worker were antimony, benzo(a)pyrene, PCE, TCE, and xylenes. Pleaseclarify these or correct discrepancies.

Response: Agree. The total cancer risk and hazard index and COCs for a future constructionworker should be consistent with the risk assessment results in Section 6. The sentence will bechanged accordingly.

5. Regarding the potential exposure to a future trespasser, although the total cancer riskand HI were below the targets of the 10"5 and 1 respectively, but the HI was different forthis scenario in Sections 6 and 7. The HI for this potential exposure scenario was listedas 0.3 in Section 6, but listed as 0.7 in Section 7.1.3. Please clarify or correct.

Response: Agree. The total cancer risk and hazard index for a future trespasser should beconsistent with the risk assessment results in Section 6. The sentence will be changedaccordingly.

TABLES

1. Table 4-1 (Soil Results Above Action Levels): Results for boring GP-39 showed a highMethod Detection Limit (MDL) for VOCs, therefore, it is difficult to assess whether other

::ODMA\PCDOCS\CLEVELAND\695127M



Page 12 of40

VOCs present in soil at this location were above project action levels. The MDLs wereelevated also for SVOCs and well above project action levels in borings GP- 44 and GP-20. High MDLs were also noted for PCBs and above project action levels for boring GP-41. These were likely attributable to high matrix interferences and, despite this, theoverall site data seems be adequate and sufficient to make risk management and remedialdecisions, based on the number of samples collected at the site. However, when youreport these results insert a qualifier to state that the MDL is greater than the action levelsfor these areas.

Response: Table 4-1 will be amended to reflect the comment

2. Also in Table 4-1 (Soil Results Above Action Levels): Dibenzo(a,h)anthracene wasshown as detected at an estimated concentration of 8.1 mg/kg. However, no sampleidentification or location was associated with this result in the table. This is also the casewith Indeno(l,2,3-cd)pyrene, which was detected at 29 mg/kg. Sample identificationslocations and intervals sampled should be associated with the findings for these samples.

Response: Table 4-1 will be amended to indicate that an estimated dibenzo (a,h) anthraceneconcentration of 8.1 mg/kg and indeno (1,2,3-cd) pyrene were encountered in GP-12 (o to 2feet).

APPENDIX D - ANALYTICAL RESULTS

General Comments

1. Footnotes to Tables 1 through 4: MCL = maximum (not median) contaminant level.Please correct.

Response: The tables will be amended to reflect the comment.

2. Provide a key or legend for interpreting the data qualifiers.

3. All tables: Why are some analytes listed with NA under the PRGs or MCLs columns,while others are blank in those columns? Please provide an explanation for this or useconsistent reporting methods.

Response: The tables will be amended to reflect the comments.

Specific Comments

1. Table 2 of Appendix D: The MDLs were above project Action Levels for groundwaterin samples GP - 06, GP -14, GP -18, and MW6 for VOCs, therefore, it is not known ifother VOCs are present in groundwater at these locations above Action Levels.




Page 13 of40

Response: Agree with comment.

APPENDIX E - ANALYTICAL DATA VALIDATION REPORTS

General Comments

1. Several of the data validation memos refer to a document called the HDD for specificdetails of qualified results. This document must be included with the RI report, or thespecific details of qualified results must be reported.

Response: The Electronic Data Deliverable (EDD) was submitted under separate cover to theregulatory agencies. A copy of the EDD CD will be included in Appendix E.

2. There should be some means of determining which sample delivery groups correspond towhich samples; otherwise it is difficult or impossible to know which samples the datavalidation memos apply to. Revise accordingly.

Response: A table will be added to Appendix E indicating which sample delivery groupcorresponds to which samples.

APPENDIX F - HUMAN HEALTH RISK ASSESSMENT

General Comments

1. To streamline the evaluation, no current risks and hazards has been estimated. However,it is important to determine whether there are current exposures that are occurring at anunacceptable level. The magnitude of a future commercial worker risks and hazardssuggest those current workers accessing the property are potentially at risk and should beevaluated. Therefore, it is recommended that current risks and hazards be quantified todetermine whether there are complete exposure pathways that warrant control in the nearterm.

Response: Agree. Although the site is currently a fenced vacant facility used for storage, andno regular workers are on the property, risks and hazards for current receptors will becalculated to quantify the risk in the revised RI report.

2. The existence of background monitoring wells and upgradient surface water and sedimentsamples are briefly mentioned However, there is no further discussion of siteconcentrations relative to background or reference. This type of discussion is importantfor naturally occurring materials and could provide important information upon whichrisk management decisions can be made. Background data for all media, if available,should be included and discussed.




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Response: Agree. The entire peninsula has been backfilled with various materials over thepast 100 plus years. In addition, industrial operations have dominated the peninsula for thelast 100 plus years. There is very little chance that true background samples can be collected,however, this item can be discussed in detail during the site meeting on 20 April 2005.

Specific Comments

1. Section 1, Executive Summary, paragraph 3, page 1 of 26: The carcinogenic risk goalof 1 xlO"5 for the site is more protective at this stage of the process when assessing riskversus the risk range recommended by the National Contingency Plan of 1 x 10^* through1 x 10"6. When setting remedial levels in the Feasibility Study (FS), and beyond, EPA'spolicy recommends a point of departure of 1 xlO"6, which is more protective at the FSstage.

Response: Agree. Appropriate Remedial levels for the risk levels ofl x Iff4 and 1 x Iff6 willbe presented in the FSfor risk management purposes.

2. Section 2.1, paragraph 3, page 2 of 26: Please provide additional detail regarding theEast Branch of the Black River that borders the site. Is it used for recreational purposessuch as boating or fishing? Is it deep enough to accommodate swimming? Or wouldwading be the primary type of exposure expected? Does the surface water depth increaserapidly with distance from the shore? Or is a gradual increase in surface water depthtypically noted? Is the surface water rapidly moving or slowly meandering? hi addition,please add the distance to the nearest residences and describe whether schools or day carefacilities are present in the vicinity of the site. This information would provide valuablecontext for the exposure assessment portion of the risk assessment.

Response: Portions of the East Branch of the Black River are relatively deep and rapidlymoving with multiple falls. Due to the natural hazard condition, the City ofElyria has anordinance (ECCO. # 521.11 A&B) that prohibits swimming in the Black River. Boating ispermissable in the public watercourse of the Black River. However, boating is dangerous nearthe site due to the under current and the proximity of the falls. In addition, the slope of thesite along the Black River is steep, which further restricts the access to the site. The closestresidents are more than 700 feet on the other side of the Black River (west). No schools ordaycare are located in the vicinity of the site. Additional information concerning the BlackRiver will be included in the revised RI report. The ordinance is included in Attachment A.

3. Section 2.1.3, Potential Areas of Concern, page 3 of 26: Only four drum storage areaswere identified in Figures 2 and 3, not the five identified in Section 2.3.3. Correct ormodify the figures. Additionally, would there be a difference in contaminantreleases/concentrations between the former and remaining parts of the Rodney Hunt StillBuildings? As reference, adjacent borings (GP19, GP20 and GP34) showed exceedances




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of Region 9 PRGs in shallow soils for TCE, PCE, arsenic, benzo(a)pyrene,benzo(b)fluroanthene, and benzo(a)anthracene. Also, only shallow groundwater isidentified as an area of concern. Since the deeper wells are contaminated (thoughcomparatively much less so), a brief discussion of the contamination of deep wells is alsorecommended for this section.

Response: There are only four drum storage areas. The text will be revised. Instead ofconsidering site shallow groundwater as a potential area of concern, a discussion of thecontaminants in groundwater (shallow and deep) will be included.

4. Section 2.5,1st paragraph, page 6 of 26: As noted in Appendix A, private wells mayexist within one-half mile of the site which are not on record with the Ohio Departmentof Natural Resources. Have restrictions been placed on the installation of future privatewells in the area? Is groundwater in the vicinity of the site used for non-ingestionpurposes such as irrigation or industrial process water? Have restrictions been placed onindustrial well installation? This information would be useful for the exposure assessmentportion of the risk assessment. If restrictions on groundwater use are not in place, pleaseevaluate potential future groundwater use to determine whether restrictions need to beconsidered.

Response: ODNR was contacted regarding the existence of water wells within a '/2-mile radiusof the site. No wells were identified within this search radius. Additionally, the City ofElyriaPublic Utility Service was contacted for information regarding any private wells in the area.The Public Utility Service informed Parsons that city water has been provided to the area forover 50 years. The City has also has rule and regulations to prohibit the installation of privatewater wells.

5. Section 3.1, 2nd bullet, page 8 of 26: Please provide the depth of standing surfacewater at each sediment collection point. Also, indicate the distance from shore for each ofthe sediment collection points. Sediment samples used in a human health risk assessmentshould be accessible to humans, considering depth of overlying water and distance fromshore.

Response: Information on the depth of standing surface water at each sediment collectionpoint, and the distance from shore for each of the sediment collection points will be includedin the revised RI report.

6. Section 3.1,1st paragraph, page 8 of 26: This section is entitled "Data Collection andEvaluation;" the text does not mention data evaluation or validation procedures that wereemployed. Were the data validated? Is so, what level of validation was performed? Wereany problems noted during validation or evaluation? Did detection limits overall meetProject Action Limits? It appears that detection limits exceed Region 9 PRGs and MCLs




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in a number of samples. Additional discussion that addresses the overall quality andsuitability of the data for risk assessment purposes must be added.

Response: Data were validated. Discussions on overall quality and suitability of the data forrisk assessment purposes will be added in the revised RI report.

7. Sections 3.1.2 and 3.1.3, page 9 of 26: Clarification is needed to determine whether totalor dissolved groundwater and surface water metals' results were considered for use in therisk assessment. It is preferable to use total metals' results.

Response: Dissolved groundwater and surface water metals results were used for the riskassessment. The analytical results show that the concentrations for dissolved and total are notsignificantly difference for selected COPCs.

8. Section 3.2,1st paragraph, page 10 of 26: How were COPCs selected for the indoor airpathway? This exposure pathway is not accounted for by the Region 9 PRGs. A separateselection process may be necessary to adequately address this pathway of concern.

Response: All VOCs that exceeded 10% of the Region 9 PRGs were included as COPCs.

9. Section 3.2.1, page 10 of 26: This section states that Region 9 residential soil and tapwater risk-based PRGs were used as screening criteria for the selection of COPCs. Theuse of residential PRGs to generate a conservative list of COPCs for both soil andsediment is consistent with 2004 Ohio EPA and USEPA guidance. However, it appearsthat industrial soil PRGs were used for soils and sediments. Please clarify and correct, asappropriate. In addition, Region 9 PRGs (set at a cancer risk of 1E-06 for carcinogens) donot require further adjustment. Only those PRGs based on non-cancer effects need to beadjusted. Please note that Region 9 PRGs have been recently updated (October 2004).The updated values should be used when revisions to the COPCs selection process areimplemented, hi addition, MCLs and Ambient Water Quality Criteria should beconsidered as additional screening criteria for groundwater and surface water COPCselection, respectively. This section also implies that statewide background levels wereused to select COPCs. Please clarify this section to indicate that background was not usedto select COPCs.

Response: Industrial soil PRGs were used for soils and sediments based on the historical siteuse, the future planning and because institutional controls restricting residential use at thesite will be implemented. The PRGs will be compared with the updated numbers in October2004. In addition, MCLs and Ambient Water Quality Criteria will be used to furtherscreening groundwater and surface water COPCs. A vailable background studies will used inthe screening process since no site-specific background is available ("ElementalConcentration in Soils and other Surficial materials of the Conterminous United States" and"Evaluation of Background Metal Concentration in Ohio Soils").: :ODMA\PCDOCS\CLEVELAND\695127\ 1



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10. Section 3.2.1, last paragraph, page 11 of 26: Please provide additional justification forthe use of maximum detected concentrations as exposure point concentrations for soilCOPCs. This paragraph states that surface soil UCLs was not calculated, yet the appendixand tables show that some were calculated. Please justify the calculation of 95% UCL foronly a select subset of COPCs. In most cases, sufficient sample numbers are available forthe calculation of a reliable 95% UCL for all media. The calculation software ProUCLVersion 3.0 is recommended for use in calculating UCLs.

Response: As stated in the risk assessment, the maximum concentrations were used for allCOPCs as a screening approach. 95% UCLs were calculated only for those COPCs thatexceeded the target risk levels to fine tune the exposure point concentrations. ProUCLsoftware will be used to run a couple of UCLs for comparison purpose.

11. Section 3.3, page 11 of 26: Provide references to document the source of the chemicaland physical property information contained in the report.

Response: The source of the chemical and physical property information will be added inSection 3.3.

12. Section 4.1.4,1* paragraph, page 13 of 26: The selection of COPCs for surface waterand sediment indicates potential site-related impacts to the river. Current exposures mayoccur infrequently, but should be quantified and included in the evaluation. Futureexposures may occur at a higher frequency and intensity should development result in anincrease in attractive potential for the area. Quantify both current and potential futuresurface water and sediment risks to recreational users of the river. The nature of thisexposure pathway should be documented, not simply presumed

Response: Agree. Evaluations will be included to justify the elimination of exposurepathways for recreational user of the river. The surface water and sediment exposurepathways are not complete under the current and future conditions because of the followingreasons:

1) City ofElyria has an ordinance prohibiting swimming in Black River;

2) The river is too deep for wading; and

3) The river is too dangerous for boating due to multiple falls along the river.These justifications will be included in the revised Rl report.

13. Section 4.1.5,1st bullet, page 13 of 26: Current receptors must be quantitativelyevaluated to determine the magnitude of risk being incurred. It is agreed that futurereceptors are potentially more exposed. However, the finding of elevated risk and hazardto future receptors suggests that current receptors accessing the property are potentially at




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risk. Therefore, it is recommended that current risks and hazards be quantified todetermine whether there are complete exposure pathways that warrant control in the nearterm.

Response: See general response # L

14. Section 4.1.5, 2nd bullet, page 14 of 26: On-site residents should be included as futurereceptors. The quantification of future residential risks will provide information todetermine whether institutional controls preventing future residential development needto be placed on the property.

Response: Although the historical use of the property and the future planning of the areashow that residential use is unlikely for the site, a residential scenario will be quantified todemonstrate the risks to potential future residential receptors in the revised RI report.

15. Section 4.1.6,2nd paragraph, page 15 of 26: The quantitative evaluation of industrialand residential groundwater use scenarios is strongly recommended. The suggestedevaluation will provide the basis for decisions concerning groundwater use restrictions, ifnecessary. Also, is the Site located within an Urban Setting Designation (USD) with thestate of Ohio? Having a USD does document the limited potential for future use ofgroundwater.

Response: The site is not located within a USD area. The closest USD is located 13 miles ofthe site. As stated in the risk assessment, there are no water wells within a one-mile radius ofthe site. In addition, no groundwater municipal water supply systems are located within afour-mile radius of the site, and there are no surface water intakes along the Black Riverwithin 15 miles of the site. The City ofElyria Health Department requires that all drinkingwater wells be installed in compliance with Ohio Administrative Code 3701-28 section 10,which states that a water source shall not be located within a minimum of fifty feet of anyknown or possible source of contamination. Therefore, the groundwater ingestion pathwaywas determined to be incomplete. This additional justification will be included in the revisedRI report.

16. Section 4.2, general, page 15 of 26: Expand this section to include a discussion of theexposure assumptions used for contact rates, exposure frequency, exposure duration,body weight and averaging time for each receptor. Professional judgment values shouldbe justified with the rationale provided for the selection of each parameter value.

Response: In general, default values were used. Section 4.2 will be expanded to include adiscussion of the exposure assumptions used for contact rates, exposure frequency, exposureduration, body weight and averaging time for each receptor.




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17. Section 4.2, last paragraph, page 15 of 26: This paragraph gives the impression thatReasonable Maximum Exposure (RME) estimates have been calculated, but CentralTendency (CT) estimates do not appear to have been included. Please confirm. If CTexposures have not been included, CT exposure estimates should be added for thosereceptors and pathways demonstrating risk above a regulatory threshold to assist in futurerisk management decisions that may be necessary for the site.

Response: Central tendency estimates were not performed for site since the reasonablemaximum exposure estimates were calculated for those receptors and pathways demonstratingrisk significantly above the target levels.

18. Section 4.3.1, Page 16 of 26: Please describe the criteria used to classify contaminants asvolatiles. Was the classification based on Henry=s Law Constants? Molecular Weight?

Response: Volatiles were defined based on the laboratory analysis list.

19. Section 4.3.1, last paragraph, page 16 of 26: The USEPA guidance documentreferenced (USEPA, 1996) was updated in March 2001. Please use the updated modelsand values provided in the 2001 document.

Response: Agree. Although the outdoor air model used in the risk calculation did not changein the March 2001 Supplemental Guidance, the March 2001 Guidance should have beenreferenced. The values provided in the March 2001 Guidance will be used in the revised RIreport.20. Section 4.3.2, last paragraph, page 16 of 26: While the text states that the Johnson &

Ettinger model is presented in Appendix C, it appears that a hybrid calculation may havebeen utilized. Please clarify if this is the case and consider improving references inAppendix C.

Response: ASTM1998 Johnson & Ettinger model was used for the indoor air calculation.The reference was included in the reference section.

21. Section 5.1, page 17 of 26: It does not appear that OSWER Directive 9285.7-53 (HumanHealth Toxicity Values in Superfund Risk Assessments, December 2003) was followed inselecting toxicity values. This 2003 directive updates the hierarchy to be used forselecting toxicity values and describes a three tiered approach to be followed that includesresearching the following primary sources of toxicity values:

• Integrated Risk Information System (IRIS),• Provisional Peer-Reviewed Toxicity Values (PPRTV)• Other (Peer Reviewed) Values, including

o ATSDR=s Minimal Risk Levelso California Environmental Protection Agency (CalEPA) values




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O HEAST

The Risk Assessment Information System (RAIS), developed by Oak Ridge NationalLaboratory, is not suggested as a source in the hierarchy and contains toxicity values thatmay not have been peer reviewed. Please revise the selection of toxicity values to complywith the December 2003 hierarchy.

Response: As stated in Section 5.1, the hierarchy source of toxicity values was followed asspecified above. Specifically, IRIS, PPRTV, and other (peer reviewed) values such as A TSDR,CalEPA and HEAST were used as sources of toxicity information in that preferential order.The Risk Assessment Information System is referenced only for additional toxicity values thatdo not have values specified in the preferred sources.

22. Section 5.1, last paragraph, page 17 of 26: Include Toxicity profiles for COPCs in anappendix to the final risk assessment report.

Response: Although the websites for toxicity profiles are provided in the text of Section 5.1,toxicity profiles for COPCs will be included in the final risk assessment report.

23. Section 5.3, Page 18 of 26: Because the airborne concentrations generated by fate andtransport modeling are in units of mg/m3, it is not necessary to adjust the referenceconcentrations to units of dose. Risk estimation can be performed using the airborne EPC,exposure assumptions to adjust for exposure frequency, duration, and time, and a toxicityvalue (i.e., reference concentration) in units consistent with the EPC. For furtherdiscussion, refer to Appendix 1A (Risk Calculations using Exposure Factors HandbookData and Dose-Response Information from IRIS) in the 1997 Exposure FactorsHandbook. This same approach is applicable to cancer risk calculations using inhalationunit risks.

Response: Agree. See response #8.

24. Section 7.0, Page 23 of 26: This section appears to be generic and should be expanded toinclude sources of uncertainty for this particular evaluation. For example, what are thelimitation and uncertainties associated with the air modeling performed? Are there anydata issues that may bias risk estimation?

Response: Section 7.0 will be expanded to include sources of uncertainty associated with theair modeling performed and data issues.

TABLES

General Comments




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1. Tables 2 through 5, footnotes: Please correct the footnote "MCLs are "MaximumContaminant Levels," not median concentration levels.

Response: The footnote will be revised,

2. Table 3, Summary Groundwater Analytical Results: Are the data from the temporarywells treated in the same way as the data from the shallow and intermediate wells? Alsonote that for some COCs (example, benzene, trichloroethene), the detection limits arehigher that the PRGs, therefore, a non-detect (ND) value in a specific well may not be atrue indicator. Perhaps a data qualifier should be added to those ND values to state thatthe ND could be due to the high MDL.

Response: The data from the temporary wells are treated in the same way as the data from theshallow and intermediate wells. A data qualifier will be added to the ND values with detectionlimits higher than PRGs.

3. Tables 6 through 9: Revise these tables to be consistent with RAGS Part D Table 2formats for the selection of COPCs. Furthermore, consider revising these tables to includeresidential soil PRGs for the soil and sediment COPC selection process. Also consideradding MCLs as additional groundwater criteria and ambient water quality criteria(AWQCs), developed for the protection of human health, as additional surface watercriteria for COPC selection. It appears that available Region 9 PRGs have not beenincluded for some compounds (e.g., di-n-butyl phthalate, 2-butanone, 4-methyl-2-pentanone, and bis(2-ethylhexyl)phthalate). Furthermore, it is appropriate to usesurrogates for analytes which do not specifically have Region 9 PRGs (e.g., usingnaphthalene for non carcinogenic PAHs lacking PRGs).

Response: Industrial PRGs were used for screening COPCs because of the future anticipatedindustrial/commercial use. Residential soil PRGs will be included in Tables 6 though 9 forcomparison purposes and for the COPC selection for the potential future residential receptors.

Tables 6 through 9 will be revised to provide additional information requested.

4. Tables 6 through 9, data management: List the samples applied to each data groupingeither on the respective tables or in a separate table. It is not always clear which samplesare utilized. Duplicates should be combined prior to determining frequency of detection.State why the groundwater has been split into shallow and deep? There appears to onlybe one scenario where it is used (inhalation) and it seems appropriate to combine bothdepth intervals.

Response: Tables 6 through 9 will include the samples applied to each data grouping.Groundwater was not split into shallow and deep since the evaluation was for one scenario.

Specific Comments




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1. Table 6, Occurrence, Distribution and Selection of COPC in Soil: The risk assessmentfollows standard practices and uses a central tendency value (95% UCL of the mean) toevaluate certain COCs. However, this approach may mask certain areas of highercontamination. For example, Aroclor 1242 was detected at 79 ppm (GP-41, 0-2 feet), andAroclor 1254 was detected at 65 ppm (GP-44,0-2 feet), from the soil sampled along thestorm sewer line. Arsenic was detected in subsurface soil at 228 ppm. At a minimum, aconceptual site model (figures) of the contaminant concentrations in the different media isnecessary, or add a reference to such figures in the Risk Assessment. If activeremediation is the forethought, it may be necessary to characterize these areas of highercontamination to better focus the remedial process.

Response: The reasonable maximum value of 95% UCL is representative of the sitecondition. A conceptual site model of the contaminant concentrations in different media willbe added to the revised RI report. Active remediation is not aforethought; capping is theremedy anticipated to be selected.

2. Table 10, page 2 of 4: The exposure point concentration and maximum concentrationsfor antimony and arsenic appear to be reversed.

Response: Table 10 will be revised accordingly.

3. Table 10: Please include similar Table 3 formats (Exposure Point ConcentrationSummary Tables) for groundwater, surface water, and sediment to document the EPCsused in the risk assessment. Similar tables should also be provided to document asummary of the EPCs for the air pathways.


4. Table 10 (Table 3.1.RME): Change the exposure medium to "Air" and define theexposure point as "on-site." It is currently unclear as to where the risk pathway appliessince migration may be considered during the evaluation. Consider listing the samplesused for this exposure point in a footnote. It appears that calculation of averages utilizedonly detects and duplicates were not combined prior to the calculation. It is appropriate tocombine duplicates and apply 2 the detection limit for non-detects during averaging andcalculation of UCLs.

Response: Table 10 will be revised to define the exposure point as on-site. Samples used forthis exposure point will be included in a footnote. Duplicates will be added to the calculations.Half of the detection limits were used for non-detects when calculating 95%UCLs.

5. Table 10 (Table 3.2.RME): Refer to previous comment regarding calculation ofaverages and UCLs. Due to the method of calculating averages, some UCLs are shown to

: :ODMA\PCDOCS\CLEVELAND\695127M



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be lower than the mean. Also note that the EPCs for antimony and arsenic in thesubsurface soil do not match the UCL value shown. Also, clarify why there are asteriskson cobalt, copper, and selenium.

Table 10 will be revised accordingly for clarity.

6. Table 12 (Table 1): This table might best be presented and discussed beforesummarizing exposure point data to clarify why certain data points have been grouped.Current exposures to soil, groundwater, surface water, and sediment are listed as beingqualitatively evaluated. Please document where the qualitative evaluation has beenincluded in the report. As previously recommended, current risks must be quantified todetermine if currently complete exposure pathways are contributing to elevated risk andhazard. Also, clarify why surface water and sediment exposure during swimming/wadingis unlikely, both currently and in the future. The selection of COPCs for surface water andsediment imply that this pathway is being included as part of the evaluation. Future tapwater and onsite residential exposures must also be included to determine the need forInstitutional Controls. The construction workers' receptor must also include inhalationexposure to volatiles contributed by groundwater. Calculations for this pathway areincluded in the appendices.

Response: Additional justification will be included in Table 12 to document the reasons foreliminating certain exposure pathways for further quantitative evaluation. The inhalationexposure to volatiles contributed by groundwater was calculated for a future constructionworker. See Attachment C of the Appendix Efor the risk calculations of this exposurepathway.

7. Table 13, general: It appears that the most recent EPA guidance documents were notused to select exposure assumptions. Please use the 1997 Exposure Factors Handbookand the 2001 Supplemental Guidance for Developing Soil Screening Levels forSuperfund Sites for updated soil ingestion and body weight data. Adult soil ingestionrates are typically adopted for juvenile receptors. For the soil dermal contact pathway,please explain the rationale for the selected soil to skin adherence factors and skin surfacearea values. State what portions of the body are assumed to be exposed and available forsoil contact. The weighted soil adherence factors should correspond to body surface areasused in their calculation.

Response: Table 13 will be revised to add the 1997 Exposure Factors Handbook and the 2001Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites as sourcesof reference. In addition, the rationale for the selected soil to skin adherence factors and skinsurface area values will be added.

8. Table 13, air pathways: For all air pathways, the models predict an airborneconcentration (i.e., mg/m3). Therefore, it is not necessary to adjust both the toxicity value




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and the airborne concentration to units of dose (mg/kg-day). The modeled airborneconcentrations can be adjusted for exposure using the receptor specific exposure times,exposure frequencies, and exposure durations. The resulting adjusted airborneconcentrations can be compared directly to the toxicity values (in units of mg/m or[mg/m3]"1) to estimate hazard and cancer risk. Therefore, inhalation rates and bodyweights are not needed to estimate risk and hazard for the air pathways. Please editequations and parameters accordingly.

Response: Agree. However, units of dose instead of unit risks were used in the riskcalculations because of the use ofASTM's indoor air model

9. Table 13, future commercial worker: State if the commercial worker is an outdoor orindoor worker? It appears that this receptor is assumed to be exposed to contaminants inoutdoor (ambient) air for 8 hours per day and also indoor air for 8 hours per day. Shouldtwo separate commercial workers be evaluated (i.e., an outdoor and an indoor worker)rather than summing the contributions from both indoor and outdoor air?

Response: The outdoor and indoor exposure pathways for a future commercial worker wereevaluated separately. The risks for outdoor and indoor scenarios were combined as aconservative approach. Two separate commercial workers will be included in the revised RJreport.

10. Table 13, future construction worker: Please explain the selection of 90 days/year asthe exposure frequency for this receptor. A six-month construction project, which isreasonable to assume based on the climate in the northern part of the country, wouldcorrespond to 120 days of exposure per year.

Response: Table 13 will be revised to explain the selection of 90 days/year.

11. Table 13, future juvenile trespasser: State what age range is assumed for the juveniletrespasser. Does the 10-year range correspond to children between the ages of 9 and 18?If so, a body weight of 53 kg may best represent the body weight of this receptor. Pleasealso justify the selection of 12 days/year as the exposure frequency for this receptor. Thisfrequency may be representative of current exposures. However, future trespassing mayoccur more frequently under the assumption that the property becomes more accessibleand attractive to children (e.g., fencing is removed and/or increased residentialdevelopment of the area). An exposure frequency of between 2 and 3 days per week forthe warmest 6 months of the year (between 52 to 78 days/year) may be more appropriateto represent a future trespassing scenario.

Response: The exposure assumptions for a future juvenile trespasser are based onprofessional judgment due to difficult access to the site from the Black River. Additionalinformation will be provided to justify the exposure assumptions in the revised RI report.




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12. Tables 14 and 15, general: Please revise the selection of toxicity values to comply withthe December 2003 hierarchy for selecting toxicity values. Furthermore, select surrogatesfor compounds lacking toxicity values. For example, naphthalene toxicity values arecommonly used as surrogates for non carcinogenic PAHs lacking compound-specificvalues (e.g., acenaphthylene, phenanthrene, etc.). Aroclor 1254 non cancer toxicity valuesare commonly used for the other Aroclors.

Responses: The source references of Tables 14 and 15 will be revised to be consistent with thetext in Section 5.1. Surrogates will be used for compounds lacking toxicity values.

13. Tables 14 and 15, oral absorption efficiencies: Please update these tables to includeoral absorption efficiencies for inorganics listed in Risk Assessment Guidance forSuperfund (RAGS), Part E (July 2004). The values for antimony, arsenic and cadmiumare not consistent with the cited reference. In addition, RAGS Part E states thosecompounds with oral absorption efficiencies of 50% or greater should be assigned an oralabsorption efficiency of 100% to reflect the variability in absorption studies. Therefore, avalue of 1 (i.e., 100%) is recommended for all organic compounds. Table 15 should listthe oral absorption efficiencies (identical to those values presented on Table 14), not theinverse of the oral absorption efficiencies. Oral absorption efficiencies presented in Table15 give the impression that certain compounds have oral absorption efficiencies in excessof 100%.

Response: Tables 14 and 15 will be updated accordingly.

14. Table 14, Sub chronic toxicity values: As recommended in RAGS Part A, sub chronictoxicity values may be developed by removing the sub chronic to chronic uncertaintyfactor (a factor of between 3 and 10) for those chronic toxicity values based on a subchronic study. For example, the Aroclor 1254 chronic reference dose (2E-05 mg/kg-day;uncertainty factor of 300) is based on a sub chronic study. A factor of 3 was applied to thetoxicity data in the derivation of the chronic value to account for the less-than-chronicstudy duration. Therefore, a sub chronic reference dose can be derived by adjusting thechronic value upward by a factor of 3 (6E-05 mg/kg-day; uncertainty factor of 100). Noadjustment should be performed for chronic toxicity values which are based on chronicstudies (e.g., antimony and arsenic). In these cases, it is customary to adopt the chronicvalue as the sub chronic value. Sub chronic values contained in a Risk AssessmentInformation System are not recommended for use.


15. Table 14, Manganese: The selection of medium-specific toxicity values for manganeseshould be accompanied by the use of a medium-specific modifying/uncertainty factor.




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The food/soil value using a combined uncertainty/modifying factor of 1 is consistent withIRIS. The water value is developed by applying a combined uncertainty/modifying factorof 3, as described in IRIS.

Response: Table 14 will be revised to show different uncertainty/modifying factor for differentmedia,

16. Table 14, cis-1,2-dichloroethene: IRIS contains an inhalation reference concentrationfor this compound. Please add this value to the table.

Response: Inhalation reference concentration mil be added to Table 14.

17. Tables 14 and 15, general: Inhalation RflCs and unit risks, rather than extrapolated RfOsand inhalation cancer slope factors, are recommended for use in risk estimation. Modeledconcentrations are derived in units of mg/m3. Therefore, RfCs and unit risks are in unitsconsistent with the modeled airborne concentrations and may be used directly withoutextrapolation.


18. Table 15, Lead: Evaluating lead using toxicity values is not currently recommended (seeIRIS for discussion). The current recommended approach for evaluating lead is throughthe use of the Integrated Exposure Uptake Biokinetic Model for children (USEPA, 2002)and the Technical Review Workgroup approach for adults (USEPA, 2003). Please usethese models to determine the potential adverse effects of lead on identified receptors.

Response: The Technical Review Workgroup approach for adults will be used to verify theresults for lead calculated using toxicity values.

19. Table 15, Benzene: Please justify the use of the midpoint of the range of values providedin IRIS for the oral slope factor and unit risk for benzene.

Response: Justifications of using the midpoint of the range of values provided in IRIS for theoral slope factor and unit risk for benzene will be added to Table IS.

20. Table 15, Vinyl Chloride: The toxicity values selected to evaluate vinyl chloride risk arerepresentative of continuous lifetime exposures from birth. Use of values developed forcontinuous lifetime exposures during adulthood may be more appropriate for adultworker exposures.

Response: Table 15 will be revised accordingly for vinyl chloride.




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21. Table 16 (Table 7.1.RME), Construction worker: It appears that both surface andsubsurface soils were combined for evaluation. It may be more appropriate to evaluate thetwo soil depth intervals separately. Furthermore, the EPCs need to be confirmed. Forexample, aluminum shows an EPC which is the maximum surface soil value. Antimonypresents the EPC for subsurface, yet the surface soil value is higher than the subsurfacevalue.


22. Table 17 (Table 9.1.RME): To apply appropriate evaluation methods and perform targetorgan segregation, please present all applicable target organs rather than just liver andkidney.

Response: All applicable target organs will be added to Table 17.

23. Table 18: For each receptor, any contaminant contributing more than a cancer risk of1E-06 (not IE-OS) and a non cancer hazard quotient of one should appear on this table.Please include any additional COPCs that meet these criteria.

Response: Due to the reasonable future industrial use, a cancer risk level of IE-OS isapplicable for the site, therefore IE-OS is used for COC selection.

24. Figure 10: This flowchart identifies soil < 3 feet in depth as surficial soil. However, itappears that soil data gathered between 0 and 4 feet were combined for the evaluation ofsurface soil exposures. For trespassers and commercial workers, the most surficial soilinterval (e.g., 0-0.5 feet, 0-2 feet, and 0-4 feet) may be the most applicable to characterizeexposures. Intervals beneath this surficial layer (e.g., 2-4 foot samples) may best beexcluded from the surface soil data set. It may also be advisable to evaluate the surficialand subsurface intervals separately. Separate evaluation of the two distinct intervals(surface and subsurface) prevents the dilution of soil contaminant levels, should oneinterval be more heavily contaminated than the other and allows for a transparentdetermination as to whether only one or both of the intervals may require action. Inaddition, all receptors may contact both surficial and subsurface soil contaminants, underthe assumption that contaminants, currently presently at depth, are moved to a moreaccessible location following future site development. Please add other receptors andpathways to the conceptual model (e.g., future on-site residents, future tap wateringestion, and recreational users of the River).

Response: The exposure pathway flowchart will be revised to less than 2 feet instead of 3 feetto be consistent with the data collected for the site. Surface and subsurface were evaluatedseparately in the risk assessment. For trespassers and commercial workers, surface soil datawere used to characterize exposures. For construction workers, surface and subsurface soil




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data were used to characterize exposures. Other receptors, such as future on-site residents,will be added to the flowchart.

25. Appendix C: Please utilize RAGS Part E in applying dermal absorption factors (DAFs).According to the guidance, DAFs are not assigned to VOCs. Because the air modelspredict an airborne concentration (i.e., mg/m3), it is not necessary to adjust both thetoxicity value and the airborne concentration to units of dose (mg/kg-day). The modeledairborne concentrations can be adjusted for exposure using receptor-specific exposuretimes, exposure frequencies, and exposure durations. The resulting adjusted airborneconcentrations can be compared directly to the toxicity values (in units of mg/m3 or[mg/m3]"1) to estimate hazard and cancer risk. Therefore, inhalation rates and bodyweights are not needed to estimate risk and hazard for the air pathways. Edit equationsand parameters in this appendix accordingly. Also, check units of the input values.Groundwater and air concentrations are sporadically labeled.

Response: see response 8.

APPENDIX G - ECOLOGICAL RISK ASSESSMENT

General Comments

1. The SLERA does not follow the USEPA 1997 Guidance. In addition to discussing sitebackground, environmental setting, contaminants at the site, contaminant fate andtransport, eco-toxicity, potential receptors, complete exposure pathways, and assessmentand measurement endpoints, and screening level exposure estimates, the SLERA shouldalso include a screening level ecological risk calculation. Typically, the risk calculationderives a hazard quotient (HQ), obtained by dividing the exposure point concentration,such as the maximum concentration for a COPEC, by a toxicity reference value, typicallythe benchmark screening value. Revise tables to include HQs for the COPECs.

Response: The SLERA does follow USEPA 1997 Guidance. Much of the informationrequested, (Le., site background, environmental setting, contaminants, contaminant fate andtransport, etc.) is contained in the main body of the RI report (e.g., site background ispresented in Section 1.2, environmental setting is in Section 3.0, fate and transportinformation is in Section 5.0, etc.), and we direct the reviewers to these sections of the RIfordetailed information concerning each of these topics. Only a summary of this informationwas presented in the SLERA, which was included as an appendix to the RI report. However,we will include additional text in the revised SLERA to address in more detail the potentialreceptors and endpoints and we will revise the tables to show a calculated HQfor the COPECsinstead of a simple statement ofexceedance or non-exceedance.




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2. A scientific/management decision point (SMDP) follows completion of the screeninglevel risk calculation. According to the Guidance, there are only three possible decisionsat his point: 1) is there enough information to conclude negligible risk, 2) moreinformation is needed so the process will continue, or 3) information indicates a potentialfor adverse ecological effects and a more thorough assessment is warranted. The SLERAstates in Section 3.0 that the site is Acontaminated with various compounds at levels thatmay be harmful to ecological receptors under conditions of long-term contact Based onthis statement, he SLERA should have concluded that preliminary risk occurs onsite andthat a more thorough assessment is warranted. Instead, the SLERA concluded that nofurther investigation is necessary because there is negligible risk. The basis forconcluding that no further investigation is necessary due to negligible risk is should berevised because the information needed to make such a conclusion is missing. Fust,though the SLERA speculates that a low temporal site use factor (i.e., a short exposuretime) mitigates risk, there is no quantitative evidence to support this argument. Toolssuch as toxicity tests, bio-accumulation studies, tissue analysis, and food chain modelsshould be used estimate chronic exposures, and then be compared to toxicity referencevalues (TRVs) to determine whether or not a risk is present and to quantify the magnitudeof that risk. Second, the SLERA did not characterize whether ecological receptors are atrisk from acute effects. Given that some exposure point concentrations exceededbenchmarks by two to three orders of magnitude, it is possible that receptors mayexperience acute effects, even during shorter exposure periods. Although the hypothesisthat a low temporal site use factor may eventually be shown to be correct, it has not yetbeen proven. The SLERA concludes that additional investigation is warranted.

Response: Although the 1997guidance states that there are onty 3 possible decisionsfollowing a SLERA, there is in fact later guidance from USEPA (ECO Update, June 2001),that allows a fourth possible decision following completion of a SLERA. This fourth decisionis presented on page 5 of the ECO Update, where "tiering" of the ERA is discussed. Withinthe discussion of tiering, the USEPA acknowledges that "Although a decision can be made toproceed with cleanup after any tier of the ERA process, for some sties of relatively small sizeor where the contamination has a sharply defined boundary, it may be preferable to cleanupthe site to the screening values rather than to spend time and resources determining a lessconservative cleanup number." Following completion of the SLERA (t(tier I"), CRShasdecided not to conduct the baseline ERA, but instead proceed to an evaluation of cleanupoptions due to the small size of the CRS site and the nature and extent of the contamination.We do agree with the comment that the conclusion that there is negligible risk at the site is not

fully supported since quantitative calculations were not conducted. Therefore, the text of therevised SLERA will be changed to acknowledge that the SLERA concluded that there ispotential risk to ecological receptors; however, given the small size of the site, and the natureand location of these COPECs, further ecological evaluation of the site will not be conductedand the screening values will be used in lieu of determining site-specific cleanup numbers forecological receptors.: :ODMA\PCDOCS\CLEVELAND\695127\1



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3. As described in the USEPA 1997 Guidance, the purpose of the risk assessment process isto characterize site related risk. Whether or not the general area continues to maintain anurbanized character may impact cleanup levels but it does not affect the type andmagnitude of site related risk. The decision whether or not to proceed with a BaselineEcological Risk Assessment (BERA) should not be made based on future land use, andshould be insulated from any other factors more appropriately considered in riskmanagement steps.

Response: Agree; see response to comment #2 above.

4. The SLERA should state whether runoff from the site into the river or discharge from anyof the storm drains are causing any physical stress, such as increased turbidity which maybe impacting aquatic communities.

Response: Agree; this information will be researched and presented in the revised SLERA.Based on existing site information (such as site topography, the steepness and rockiness of theriver bank, the small amount of river frontage, and the presence of a vegetated filter strip atthe top of the river bank), we do not think that site runoff is a major contributor of sedimentload to the Black River. The storm drains may be a potential source of sediment load;however, the replacement and upgrading of these drains by the City ofElyria is beinginvestigated as part of this RI/FS.

5. The SLERA document would be improved by more detailed discussions of facts andassumptions influencing site background, environmental setting, contaminants at the site,contaminant fate and transport, eco-toxicity, potential receptors, complete exposurepathways, and assessment and measurement endpoints, and screening level exposureestimates. For example, information pertaining to size, turbidity, flow characteristics,substrate, etc., of the Black River has not been included. Provide more detail, or ifinformation has been discussed in previous reports, include appropriate discussions as anappendix.

Response: Agree; additional information will be presented in the revised SLERA—see alsoresponses to comments #1 and #4, above.

6. Include a discussion of how and when soil, sediment, and surface water screeningbenchmarks were selected.

Response: Agree.

1. Comments made to text and tables should also be carried to the Executive Summary.

Response: Agree.




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Specific Comments

1. Section 1.0, page 3, Vegetation: Text states that the nearest wetland area is located 15miles downstream. Under the Clean Water Act, the Black River is a wetland area. Revisetext to acknowledge that the site therefore borders a wetland area.

Response: Agree; it will be clarified in the text that the Black River may be considered awetland in some classification systems.

2. Section 2.1, l" sentence, page 5, Identification of COPECs in Surface Soils: The textreads that samples collected between 0 to 4 feet below ground surface were included insoil screening. Typically, soil screening consists of samples between 0 and 2 feet. Revisesoil screening concentrations.

Response: 0 to 4 feet was utilized for screening purposes as agreed to in the site work plansince it is more conservative than using just the 0 to 2 feet range, especially when evaluatingpotential impacts to vegetation (because roots may extend below 2 feet) and to burrowinganimals, which might also encounter contaminants below 2 feet. Since the maximum detectedvalue within the entire 0-4 feet range was utilized whether or not it occurred within the 0-2foot range or the 2-4 foot range (Le., the concentrations within the ranges were not averaged),we do not think the soil screening concentrations should be revised.

3. Section 2.1, page 5, Identification of COPECs in Surface Soils: EPA Ecological SoilScreening Levels (Eco-SSLs; USPEA, 2003a) and Region 5 Soil Screening Criteria(USEPA, 2003b) should be given prominence in the hierarchy of values utilized. Thesebenchmarks were not considered at all. These benchmarks are generally lower than thosecited in the text, and use of these benchmarks would result in additional soil COPECs(ex. beryllium, silver). Revise screening to include these sources and update textaccordingly.

Response: ECO-SSLs will be given priority when screening soil data. ECO-SSLs were notused in the initial SLERA since there are only 7 compounds that have ECO-SSLs publishedand there are over 100 potential COPECs. However, for these 7 compounds, (antimony,barium, beryllium, cadmium, cobalt, lead and dieldrin), the ECO-SSLs will be given priority.Additionally, Region 5 Soil Screening Criteria were used in the SLERA for screening soildata. The Region 5 ESLs are mistakenly referred to as "EDQLs" in Table 1; but in fact, theupdated Region 5 ESLs published in 2003 were utilized for the screening process. TheseRegion 5 ESLs will be given second priority in the soil screening hierarchy. Should both anECO-SSL and a Region 5 ESL be unavailable, then alternative benchmarks, such as thosepublished by Efroymson, et. al. (1997), will be used. The tables and text will be updated andcorrected in the revised SLERA.




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4. Page 5, Table 1: For screening levels for inorganics that are protective of differenttrophic levels (visit: http://www.epw.gov/ecotox/ecossl). Also, effects on terrestrialvegetation are not evaluated, but a clear rationale has not been presented in this section.This rationale should be added. However, if it is believed that from a future usestandpoint, terrestrial vegetation needs to be evaluated in specific areas of the site (forexample on the river bank), the assessment should be updated to include the terrestrialplants screening levels (visit: http://www.hsrd.oml.gov/ecorisk/tm85r3.pdf).

Response: As stated above, ECO-SSLs will be given priority in the soil screening process. Tobe protective of all potential receptors, the lowest screening value will be used in accordancewith the screening hierarchy specified in response to comment #3 above.

5. Section 2.1, page 5, Identification of COPECs in Surface Soils: Some soilcontaminants of interest which were retained because they exceeded benchmarks may beeliminated based on a detection frequency of less than 3 percent.

Response: Agree; any contaminant of concern that is detected at a frequency of less than 3percent will be eliminated from further consideration in the SLERA.

6. Section 2.2,1st paragraph, page 6, Identification of COPECs in Sediments: The textreads that TECs from MacDonald, et al. (2000) were used as sediment screening values.However, Table 2 footnotes indicate that Ecological Data Quality Levels from EPARegion 5 were used. Please revise text and/or tables to agree with each other.

Response: Both the TECs from MacDonald (2000) and Region 5 ESLs (2003) were used toscreen sediment data. TECs were used preferentially over the Region 5 ESLs, if available.The text and tables will be revised to reflect this process.

1. Section 2.3, page 6, Identification of COPECs in Surface Water: Note in textwhether surface water criteria have been adjusted for hardness.

Response: Surface water criteria were based on an assumed water hardness of 100 since site-specific data are not available. This will be clarified in the text and on Table 3 of the revisedSLERA.

8. Section 2.3.1, page 6, Identification of COPECs in Surface Water (Ohio EPADivision of Surface Water (DWS) standards): These standards have been updated(8/5/04). Generally, the Outside Mixing Zone Average (OMZA) and not the OutsideMixing Zone Maximum (OMZM) standards are used to evaluate any impacts to surfacewater at Ohio EPA sites (using the OMZM standard is protective of aquatic life for long-term exposures); although, both can be presented. Ohio EPA=s DWS=s current approachis not to allow a mixing zone for non-point source discharges. Revise this section and theassociated tables.




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Response: Agree; updated Ohio EPA OMZA standards mil be used in lieu of Ohio EPAOMZM. The text and Table 3 will be revised.

9. Table 1, Soil Screening Levels: There is an error in the screening benchmarkscomparison presented for some COCs - the PCB benchmarks are presented as ppb(jag/kg), but the site concentrations are ppm (mg/kg) and, so, specific Aroclor should notbe screened out of consideration. Also the screening level for 2-hexanone is 1.26E404

ppb, and not 8.96E+<)4 ppb. Please revise the table.

Response: Agree; the tables mil be revised as indicated.

Also note that generally, the screening levels are segregated on the basis of receptors(plants, terrestrial organisms, etc.). Persistent, bioaccumulative toxic chemicals, such asPCBs, should not be screened out, unless the screening levels are protective of highertrophic level receptors.

Response: Agree; persistent, bioaccumulative chemicals mil not be screened out unless thescreening levels are specifically protective of higher trophic level receptors.

10. Table 2, Sediment Screening: For several chemicals, the Reference column noteindicates that the source of sediment screening value is MacDonald, et al. (2000),although the original source does not list a TEC for that specific chemical (ex. antimony).Revise reference note to correct source or remove the screening criteria.

Response: Agree; the references mil be updated to reflect the correct source.

11. Table 3, Surface Water Screening: Refer to previous comments on the use of theOMZM versus OMZA, and available updated (8/5/04) DSW standards.

Response: Agree; see also response to previous comment regarding the use ofOZMA versusOMZM.

REFERENCES FOR ECOLOGICAL RA COMMENTS

1. MacDonald, et al. 2004. Development and evaluation of consensus-based sedimentquality guidelines for freshwater ecosystems. Archives of Environmental Contaminationand Toxicology 39:20-31.

2. U.S. Environmental Protection Agency (USEPA). 2003a. ECO-SSL - Ecological SoilScreening Levels, Interim Final. Office of Emergency and Remedial Response,Washington, DC: November, 2003

3. U.S. Environmental Protection Agency (USEPA). 2003b. U.S. EPA Region 5 EcologicalScreening Levels, August 22, 2003. See: http://www.epa.gov/Region5/rcraca/ESL.pdf




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4. U.S. Environmental Protection Agency (USEPA). 1997. Ecological Risk AssessmentGuidance for Superfund: Process for Designing and Conducting Ecological RiskAssessments. EPA 540-R-97-006. June 1997.

END OF DRAFT RI REPORT COMMENTS

REVIEW COMMENTS TO THE DRAFT FEASIBILITY STUDY(REVISION 0, NOVEMBER 2004)

CHEMICAL RECOVERY SYSTEMS INC.

General Comments

1. The Draft FS Report may require future revisions based on simultaneous review andsubsequent comments on the Draft RI Report.

Response: Comment noted.

2. Further evaluation of the arsenic levels identified in all medium at the Site should beperformed to determine if it is background. The elimination of arsenic as a COC wouldpossibly make other remediation alternatives feasible.

Response: The entire peninsula has been backfilled with various materials over the past 100plus years. In addition, industrial operations have dominated the peninsula for the last 100plus years. There is very little chance that true background samples can be collected, however,this item can be discussed in detail during the site meeting on 20 April 2005.

3. Combinations of remedial technologies were not discussed. Were any combinations (i.e.,excavation of hot spots, then on-site treatment) considered? Please include discussion ofsuch.

Response: This request was not made when comments were received on the "Memorandumon Development and Preliminary Screening of Alternatives, Assembled Alternatives ScreeningResults and Final Screening". Due to the extent of the contamination across the Site, hot spotremoval was not considered to be a viable option. This option will be added to the table andscreened out.

4. Throughout the FS, cost estimates are provided for different remediation alternatives.Calculations used to determine these estimates are not provided in the FS; therefore, the




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validity of the estimates cannot be evaluated. At a minimum, quantities and assumed unitcosts for materials should be presented. This information must be provided to evaluatethe cost estimates.

Response: An Appendix will be provided with the cost estimate calculation sheets.

5. Throughout the document, soil volatile chemicals to indoor air is recognized as aexposure pathway. This exposure pathway is not addressed by capping of the site. Detailsmust be provided for each of the capping alternatives describing how this exposurepathway will be eliminated.

Response: Soil volatile chemicals to indoor air exposure pathway will be re-evaluated in therevised risk assessment to include all data points within a reasonable building size (50'x 50').If the indoor air exposure pathway is a pathway of concern, alternative methods such as vaporbarrier or a deed restriction prohibiting construction of a building in the area of concern willbe evaluated in the revised FS.

Specific Comments

1. Section 1.2.4.1, 2nd paragraph, page 6 of 35: The last sentence of this paragraph readsthat only GP-16 could be analyzed for the full suite of analytes due to limitedgroundwater. This should be clarified to reflect that this is with respect to the temporarymonitoring wells only. Permanent monitoring wells were evaluated for the full suite ofanalytes.

Response: This Section will be revised to agree with the final RI Report

2. Section 1.2.5.2, 5th paragraph, page 9 of 35: There is no supporting evidence providedfor the statement that Site conditions are favorable for the degradation of SVOCs. Thisevaluation must be discussed for this statement to be considered valid. This comment isthe same as for Section 5 in the RI Report review.

Response: The Section will be made to repeat theRI Report.

3. Section 1.2.5.3,1st paragraph, page 12 of 35: Benzo (a) pyrene was detected in allsediment samples except the upstream sample, which would indicate impact from theSite. Yet this paragraph states that SVOC impacts are limited to soil and groundwater.The apparent impact to the sediment should be taken into consideration when developingthe remedial alternatives.

Response: The text will be amended to indicate that estimated concentrations ofbenzo (a)pyrene was encountered in sediment samples along the site. Based on these low estimatedconcentrations, we do not believe that the remedial alternatives should be amended.




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4. Section 2, last paragraph, 5th sentence, page 16 of 35: EPA disagrees with thestatement that there are no COCs identified in the ground water. There are several siteCOCs that were detected in ground water beneath the site which are likely attributable topast site operations. Even though VOCs were not detected in surface water andsediments, and ground water is not utilized at the site or in the area, VOCs were detectedin groundwater at the site above Region 9 PRGs for industrial settings, and/or EPAMCLs.

Response: The text will be amended to indicate that there are not completed pathways forgroundwater.

5. Section 2.4,2nd paragraph, page 17 of 35: This paragraph states that "modeling predictsthat soil to groundwater leaching may be a potential future issue in the northwest cornerof the site." Results of this modeling are not presented in the RI report or FS. Datasupporting this conclusion must be provided.

Response: The modeling results will be provided.

6. Section 2.4,2nd paragraph, page 17 of 35: The volume of unconsolidated materials isestimated at approximately 36,000 cubic yards. Calculations must be provided to supportthis estimate.

Response: The basis for this quantity will be included.

1. Section 2.5.1, page 17 of 35: It is referenced that Table 2 shows remedial technologytypes, and process options. However, there is not Table 2 specifically in the document.Perhaps the intent was to specify Table 2.2 for this reference, and section in the report.Please review and correct.

Response: The reference will be corrected in the Final FS.

8. Section 3.1,2nd paragraph, page 18 of 35: The statement is made that A "fence wouldbe placed around the entire Site perimeter." Figure 3-1 only shows the fence to the top ofthe river bank. The river bank is part of the site, and is not included in the fenced in area.This statement should be clarified.

Response: It is not practical to put a fence at the bottom of the steep bank thus the fence onthis side of the Site is placed at the top of the bank. A statement as to why the fence is notbeing placed at the "perimeter" on this side of the Site will be added to the Report

9. If the ground water flow is toward the river, it is unclear as to how effective animpermeable barrier layer would be over the 0.5 acres in the northwest comer of the siteto prevent potential leaching to groundwater. The barrier layer in this area could

:: ODMA\PCDOCS\CLE VELAND\695127\ 1



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potentially aid in less leaching to groundwater; however, constituents' mobility wouldlikely not change much due to the small surface area of the barrier layer consideringupgradient recharge and direction of groundwater flow. The geosynthetic layer would beeffective in preventing direct contact with impacted soils above site action levels.

Response: The concern in this area is the leaching of water down through the upper layer ofsoil, not groundwater traveling horizontally below the cap. The impermeable cap will stop theleaching of water through the upper soil layer.

10. Section 4.2.2.8, page 24 of 35: The capital cost for construction of $762,000 for the soilcap alternative does not match the cost presented in Table 3.2. Even assuming that thecost presented in Table 3.2 for deed restrictions and fencing are added to the capping cost,there is a discrepancy in the number. This observation holds true for all cap alternativespresented. Please clarify this difference. If the cost estimate of $680,000 is minus the costof $84,500 for the geosynthetic cap in the northwest comer, then it should be included asit appears to for Alternative #3 (Stone Cap), #4 (Asphalt Cap), and #5 (Concrete Cap).

Response: This difference is a result of these estimates being conducted at different points inthe FS process and some items not being included in the earlier estimate. The estimates willbe revised so that the numbers will agree.

11. Regarding Institutional Controls proposed for the site. It reads in Section 3.1, page 18 of35 (Development of Alternatives) that a deed restriction will be placed on the site to limitfuture use to commercial/industrial usage that is consistent with the assumptions specifiedin the HHRA.

Response: No response required.

12. Any Institutional Controls (ICs) implemented at the site should be designed to helpminimize potential exposure, and to protect any engineered part of a remedy. It will beimportant to define how site Institutional Controls will be monitored, enforced, and whois responsible for implementation of the controls.

Response: Additional description of the Institutional Controls will be provided.

13. Table 3.2,1st page, under the Deed Restrictions Alternative: EPA does not agree thatoperation and maintenance or monitoring is not required under the ImplementabilitvEvaluation. Monitoring and enforcement is important to overall success of any ICs. Animportant aspect to ensure long-term effectiveness of ICs will be periodic monitoring.There needs to be a process after a remedy is in place that routinely evaluates each 1C todetermine: (1) whether the 1C remains in place; and (2) whether it remains protective.

Response: The Table will be revised to reflect the comment.

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14. Although ICs for any remedy can more thoroughly be dealt with during the RemedialDesign, and subsequent Operation and Maintenance Plan, it is important to define thefollowing now:

• implementation responsibility;• financing;• any coordination with local governments, and agencies;• ICs monitoring;• ICs enforcement; and• ICs type and mechanism

Response: This information will be provided in some level of detail in the FS.

15. Section 4.2.3.7, page 26 of 35: The square yardage of stone is estimated to be 8,600square yards for a two acre cap. Two acres is 9,680 square yards. Please explain thediscrepancy. Also, a cubic yard estimate of the stone quantity would be more appropriatesince the cost for a stone cap would typically be estimated by the cubic yard or ton ofstone.

Response: The actual area receiving stone when calculated from the drawing isapproximately 8,600 square yards. The impermeable cap area is approximately 2,300 squareyards. As the Site is considered to be approximately 2.5 acres, these two cap areas werereferred to being 2 acres and 0.5 acres in size. The slight discrepancy is in the slope area.

16. Table 3.2: Costs associated with the excavation alternative need further support.Methods used to determine the volumes of hazardous and non-hazardous waste should befurther identified.

Response: The cost estimate calculation sheet for the excavation alternative will be included inthe Appendix. At this time, it is not known how much of the soil would be consideredhazardous or non-hazardous. For cost estimating purposes, it was assumed that 75% wouldbe non-hazardous. The cost if all of the soil had to be disposed as hazardous was alsoincluded,

17. Table 3.2: Are costs associated with the repair of the storm sewer included in eachalternative? Since this repair would be required for all alternatives, is should be brokenout individually like the deed restrictions and fence.

Response: It is included in the cost for each Alternative in Table 4.1.

18. Figure 3.2: The detail for the soil cap indicates that the soil cap will extend below theexisting grade. How would this be accomplished without removing soil? Additional detailmust be added to show how this would be accomplished without removing the soil.




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Response: The surface of the Site would need to be regraded so that the cap termination atthe perimeter would match existing grade. A statement clarifying this will be added to the text

END OF DRAFT FS STUDY COMMENTS




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ATTACHMENT A

:ODMA\PCDOCS\CLE VELAND\695127\ 1



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General Comments

Since the surface runoff was identified as one of the primary means of contaminant migration,the river bank appears to be a likely location of surface soil contamination. For now, only twosoil samples (HA- 4 and HA-5) were taken on the bank on the west side of the Site, headingdown to the river. These sample locations were in close proximity to each other at the south endof the bank. Therefore, it is not feasible to make a determination regarding the river bank fromthese two sampling points. This area needs to be fully evaluated to determine if it must beremediated, and the results of the evaluation included in the RI Report.


Specific Comments


1. Section 2.1.1.1, paragraph 1, page 6 of 29: The draft report reads that a total of 40 soilborings was advanced at the site using direct push technology. Additionally, five surfacesoils borings were also collected from the top of the river bank using a hand auger. Thesample designations were HA01 - HA05. In Section 4.0 (Nature and Extent of Impact) itis stated that a total of fifty soil borings was installed at the site for soil and ground watercharacterization. For consistency, it should be stated in Section 2 that an additional fivesoil borings were installed during phase II of the investigation, which evaluated the sewerline. It is confusing to read in Section 2 that 40 total soil borings were advanced duringthe investigation, and in Section 4 it reads that 50 total borings were installed for soil andground water sampling. Please check and correct to have the numbers agree in thosesections.

Response: A total of SO soil sampling locations were advanced (GP-1 through GP-45 - direct




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Response: The text will be amended to clarify that only temporary monitoring point GP-16had sufficient groundwater for analysis besides VOCs and that Monitored NaturalAttenuation parameters were collect at each permanent monitoring well


Response: All temporary monitoring points remain in the ground at the site. The boring logsfor GP-2, GP-9, GP-19, GP-26 and GP-37 will be amended. All temporary monitoring pointswill be properly abandoned once site characterization activities are complete.








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Response: MW-6 is the only significantly impacted permanent well. The impactedgroundwater has not significantly migrated from MW-6 to any of the down-gradientmonitoring wells, which lends credence to natural attenuation at the site. The last sentencewill be changed to "The groundwater VOC analytical results indicated that conditions at theSite are favorable for degradation ".


Response: MW-6 is the only significantly impacted permanent well. The impactedgroundwater has not significantly migrated from MW-6 to any of the down-gradientmonitoring wells, which lends credence to natural attenuation at the site. In addition,SVOCs in groundwater degrade, albeit slower than VOCs. However, there appears tobe an absence of data which can be used to definitively indicate that SVOCs aredegrading in groundwater at the site. The section will be amended to reflect thisresponse.

6.0 RISK ASSESSMENT





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cumulative risk of 10"6 and hazard level of 1,10% of the PRGs were ... This languageshould be changed to read: To ensure the cumulative risk of 10"6 cancer risk or less, and ahazard index of 1.0 or less, PRGs were used for comparison. If the maximumconcentration of a chemical detected at the site, for any specific media, exceeds or isequal to 10"6 cancer risk, or exceeds or is equal to a hazard quotient of 0.1, the chemical isconsidered a COC.


2. The Agency has a regional memorandum for identifying and selecting COCs atSuperfund Sites. The Agency mentioned this memo in previous comments to the workplan. The memo provided was dated November 22,2002, which should have been usedfor this purpose. It is unclear what is meant by 10% of PRG were used for comparison.

Response: The 10% PRG approach is consistent with what was stated in the November 22,2002 regional memorandum to include cumulative effects by assuming that siteconcentrations that are less than 10% of the PRG will not contribute cumulative risk to withinone significant digit.

3. Section 6.1, paragraph 3,2nd sentence, page 24 of 29: "The anticipated future use ofthe site is to remain commercial and industrial." If this is so, some form of institutionalcontrol (ICs) is required for this site to ensure that it will not be converted to residentialuse, some day down the road. This is so, even if a remediation takes place based onindustrial/commercial use. Therefore, unless ICs are put in place the remediation wouldhave to be based on residential use.


4. Section 6.1, paragraph 3,5th sentence, page 24 of 29: "The potential exposurepathways evaluated . . ." This sentence should be changed to read: The potentialexposure pathways evaluated for the site include soil ingestion, soil dermal contact, theinhalation of soil volatile chemicals to indoor and outdoor air, the inhalation ofgroundwater volatile chemicals to indoor and outdoor air, and groundwater dermalcontact.

: :ODMA\PCDOCS\CLE VELAND\69512 7\ 1




Page 6 of40


Response: The U.S. EPA 1996 model was used for the soil volatile chemicals to outdoor airnot the soil volatile chemicals to indoor air. The ASTM model was used to evaluate soil toindoor air pathway. The ASTM model is based on the Johnson and Ettinger model; however,the ASTM model does not include advection. The ASTM model was selected based on thefollowing: 1) a previous study performed by Parsons shows that the modeled concentrationsusing ASTM model were within an order of magnitude of the monitored indoor airconcentrations without indoor/outdoor sources (Parsons, 2000. Baseline Risk AssessmentReport for Areas West of460-489 Harbor Boulevard in the Vicinity of 511 O'NeU AvenueBelmont, California); and 2) ASTM model is an approved model for other regulatoryprograms. For the potential future residential scenario, the current US EPA's Indoor AirModel will be used for comparison purposes in the revised RI report.

6. • ndSection 6.1, paragraph 5, 2 sentence, page 24 of 29: Risk numbers are given for soilexposures only. Since groundwater volatile chemicals and dermal contact pathways werealso evaluated, why are they excluded from the summary?

Response: The total cancer risk and total hazard index calculated for a future commercialworker and a future construction worker do include groundwater exposure pathways.Therefore, the 1st sentence of the 1st bullet of paragraph 5 will be changed to "The totalcancer risk and total hazard index resulting from exposure to COPCs in soil and groundwaterfor a future commercial worker were calculated to be 3 x Iff4 and 23, respectively." The 1stsentence of 2nd bullet of paragraph 5 will be changed to "The total cancer risk and totalhazard index resulting from exposure to COPCs in soil and groundwater for a futureconstruction worker were calculated to be 2 x Iff5 and 3.5, respectively".




1. Section 6.2, page 25 of 29: Based on this paragraph, a claim has been made that there is: :ODMA\PCDOCS\CLEVELAND\695127\ 1



Page 7 of40


Response: The statement made in this paragraph was not meant to impfy that "there is nowildlife because the habitat is unsuitable". Instead, we were making the point that the siteis so heavily developed for industrial use, that there is very little natural habitat availablefor wildlife to use-especially when considering the terrestrial habitat. In essence, we werefollowing the guidance for evaluating contaminants in soils that is contained on pages 1-5and 1-6 of the ECO-SSL guidance (USEPA, 2 003 a) which states: "An exposure pathway isnot considered complete if natural habitat for ecological receptors is not present and is notexpected to be present in the future" and "Exposure pathways may not be consideredcomplete for ecological receptors if the site is within urban and/or industrialized areaswhere natural habitat and receptors are absent." An exception to this is if there is thepotential for protected species to use the site; however, this is not the case for CRS sincethe Ohio Department of Natural Resources confirmed that no endangered and/orthreatened species occur at or near CRS (refer to Appendix A of the SLERA).Furthermore, we disagree that the site has not been adequately characterized. In additionto the numerous site-specific studies that are detailed in Sections 1 through 3 of the RIreport, a number of other studies have been undertaken by an adjacent property owner(Engelhard Corporation) and by the Ohio EPA (of the Black River) that provide additionalinformation concerning the nature of the area. Therefore, the site and surrounding areahave been well characterized allowing us to make such a conclusion in the SLERA.However, we do agree that a summary of this additional supporting information would behelpful for a person reviewing this document; therefore, a summary of these studies and adetailed habitat map will be included in the revised SLERA to support this claim.


Response: Additional detail of the dams and other sources of potential impact to aquatic life,specifically in the vicinity of CRS, will be provided in the revised report




Page 8 of40

3. In addition, there are a number of inorganic and organic Contaminants of PotentialEcological Concern (COPECs) whose maximum concentrations exceed screeningbenchmark values (thus suggesting the possibility of ecological risk). These exceedencescontribute to the uncertainty over the claim that nearby dams is the limiting factors forviable and sustained benthic invertebrate communities. Please provide evidence thatsupports the claim that it is the dams, and other physical stressors, or whether, it is thechemical stressors that are impacting the benthic communities.



Table 1. Comparison of PRGs and Eco-SSLs (where available); units for all values: mg/kgCOPEC

AntimonyBarium

BerylliumCadmium

CobaltLead

Dieldrin

PRO

5 (plant)283


woodcock)20 (plant)

40.5(woodcock)

n.a.


78330

40140

1700

Eco-SSL(plants)

32

110

Eco-SSL(birds)

1.0

19016

0.0016

Eco-SSL(mammals)

0.291000

360.38

24059

0.00028





Page 9 of40

two available ECO-SSLsfor barium. Also, for compounds that lack both an ECO-SSL and aRegion S ESL, the soil PRG will be used as an alternative screening value.


Response: Agree; site-specific soilpH data will be collected. If the soilpH is greater than 5.5,aluminum will be removed as a compound of concern in soils.

6. The report incorrectly states that minimizing human health risk "should be adequatelyprotective for the ecological receptors that might inhabit such an urbanized environment."However, because effects' levels are different between ecological and human receptors,

it does not necessarily follow that ecological receptors will be protected at contaminantlevels that are protective of human health. Contaminant levels should be screened againstthe appropriate ecological screening values. If there are levels of COPECs that exceedno-effects levels (the level of contamination below which no adverse effects areexpected), then ecological receptors are potentially at risk, regardless if the contaminantlevels are below levels of human receptors.

Response: We agree that ecological effects may still occur even if the risk to human health isminimized; however, this statement was made to assist the risk managers when consideringthe current and planned future use of the site, which is industrial In fact, for a lot of smallindustrial sites such as CRS, wildlife is actively discouraged from utilizing the site in order toprevent attracting unwanted vectors (nuisance birds, rodents and insects). Nevertheless, thetext will be revised to reflect that not all ecological receptors may be protected even if humanhealth risks are minimized.


Response: See also responses to comments #2 and #3 above regarding the supplementalinformation that will be provided in the revised SLERA concerning the Black River. Forinstance, the river frontage for the site is just over 400 feet and most of this frontage is verysteep and rocky. Thus, there is little suitable habitat available for fish species to nest and/orforage adjacent to the site. Additionally, one of the primary exposure pathways far fish isdirect contact with surface water; and based on the surface water screening results, surfacewater is not impacted at the site. Therefore, if fish are not present, it would appear to be morelikely due to the lack of suitable habitat versus chemical stressors.




Page 10 of40


Response: As stated previously in response to comment #1 above, there is very little naturalhabitat available at the site; therefore, most exposure pathways are not complete, especially fortransient animals that are associated with the terrestrial areas of the site. For example, theentire site is only 2.5 acres in size, and more than 75% of this area has been physically altered(buildings, paved, etc.). Additionally, when comparing what little site habitat there is tohabitats available on nearby properties, it is not evident that the CRS site has any areas thatwould be considered preferentially attractive to wildlife. Despite this fact, soils, surface waterand sediments were evaluated in this SLERA in order to determine the risk to all potentialreceptors coming into contact with these media—if even for only a brief period of time. Thescreening values used in the SLERA are based on chronic exposures for the most sensitiveplants and animals and they do not consider the amount of time spent by the receptor at a site(Le., the receptors are considered to spend their entire lives at the site). Therefore, thepotential risk to urban animals was not dismissed and is actually likely to be overestimated.Furthermore, we disagree that domesticated animals (Le., cats and dogs) should be consideredecological receptors as suggested in this comment. First, the site is and will be fenced.Second, domesticated animals should be leashed (the City ofElyria has a "leash law"),'therefore, these animals would not have access to the site. Lastly, feral cats and dogs areconsidered to be nuisance and/or potentially dangerous animals, and would have to beremoved from the site as soon as they are discovered.



bullet, page 25 of 29), it is stated that the total cancer risk and Hazard Index (HI) fromexposure to COPC in soil for a future commercial worker was calculated to be 3x10^ and23, respectively, However, in Section 7.1.3, these calculations for a future commercialworker were reportedly calculated to be 4x10^ and 10, respectively, for total cancer riskand HI. Clarify or correct.




Page 11 of40

Response: Agree. The total cancer risk and hazard index for a future commercial workershould be consistent with the risk assessment results in Section 6. The sentence in Section 7will be changed accordingly.2. Section 7.1.3, 2nd paragraph, page 27 of 29: The COCs are not consistent in their





Section 6 of the report were listed as 2 x 10"5 and 3, respectively. In Section7.1.3 for thisexposure scenario, the total cancer risk and HI is listed as 4 x 10~5 and 8 respectively.The COCs for this scenario listed in Section 6 were listed as benzo(a)pyrene,dibenzo(a,h)anthracene, and TCE. However, in Section 7.1.3, the COCs for the futureconstruction worker were antimony, benzo(a)pyrene, PCE, TCE, and xylenes. Pleaseclarify these or correct discrepancies.


5. Regarding the potential exposure to a future trespasser, although the total cancer riskand HI were below the targets of the 10~5 and 1 respectively, but the HI was different forthis scenario in Sections 6 and 7. The HI for this potential exposure scenario was listedas 0.3 in Section 6, but listed as 0.7 in Section 7.1.3. Please clarify or correct.


TABLES





Page 12 of40


Response: Table 4-1 will be amended to reflect the comment.




General Comments


Response: The tables will be amended to reflect the comment




Specific Comments





Page 13 of40

Response: Agree with comment.


General Comments

1. Several of the data validation memos refer to a document called the HDD for specificdetails of qualified results. This document must be included with the RI report, or thespecific details of qualified results must be reported.





General Comments



2. The existence of background monitoring wells and upgradient surface water and sedimentsamples are briefly mentioned. However, there is no further discussion of siteconcentrations relative to background or reference. This type of discussion is importantfor naturally occurring materials and could provide important information upon whichrisk management decisions can be made. Background data for all media, if available,should be included and discussed.




Page 14 of40

Response: Agree. The entire peninsula has been backfilled with various materials over thepast 100 plus years. In addition, industrial operations have dominated the peninsula for thelast 100plus years. There is very little chance that true background samples can be collected,however, this item can be discussed in detail during the site meeting on 20 April 2005.

Specific Comments

1. Section 1, Executive Summary, paragraph 3, page 1 of 26: The carcinogenic risk goalof 1 xlO"5 for the site is more protective at this stage of the process when assessing riskversus the risk range recommended by the National Contingency Plan of 1x10^ through1 x 10"6. When setting remedial levels in the Feasibility Study (FS), and beyond, EPA'spolicy recommends a point of departure of 1 xlO"6, which is more protective at the FSstage.

Response: Agree. Appropriate Remedial levels for the risk levels of I x Iff4 and 1 x Iff6 willbe presented in the FSfor risk management purposes.

2. Section 2.1, paragraph 3, page 2 of 26: Please provide additional detail regarding theEast Branch of the Black River that borders the site. Is it used for recreational purposessuch as boating or fishing? Is it deep enough to accommodate swimming? Or wouldwading be the primary type of exposure expected? Does the surface water depth increaserapidly with distance from the shore? Or is a gradual increase in surface water depthtypically noted? Is the surface water rapidly moving or slowly meandering? hi addition,please add the distance to the nearest residences and describe whether schools or day carefacilities are present in the vicinity of the site. This information would provide valuablecontext for the exposure assessment portion of the risk assessment.






Page 15 of40


Response: There are only four drum storage areas. The text will be revised Instead ofconsidering site shallow groundwater as a potential area of concern, a discussion of thecontaminants in groundwater (shallow and deep) will be included.


Response: ODNR was contacted regarding the existence of water wells within a '/i-mile radiusof the site. No wells were identified within this search radius. Additionally, the City ofElyriaPublic Utility Service was contacted for information regarding any private wells in the area.The Public Utility Service informed Parsons that city water has been provided to the area forover 50 years. The City has also has rule and regulations to prohibit the installation of privatewater wells.

5. Section 3.1, 2nd bullet, page 8 of 26: Please provide the depth of standing surfacewater at each sediment collection point. Also, indicate the distance from shore for each ofthe sediment collection points. Sediment samples used in a human health risk assessmentshould be accessible to humans, considering depth of overlying water and distance fromshore.






Page 16 of40


Response: Data were validated. Discussions on overall quality and suitability of the data forrisk assessment purposes will be added in the revised RI report





9. Section 3.2.1, page 10 of 26: This section states that Region 9 residential soil and tapwater risk-based PRGs were used as screening criteria for the selection of COPCs. Theuse of residential PRGs to generate a conservative list of COPCs for both soil andsediment is consistent with 2004 Ohio EPA and USEPA guidance. However, it appearsthat industrial soil PRGs were used for soils and sediments. Please clarify and correct, asappropriate. In addition, Region 9 PRGs (set at a cancer risk of 1E-06 for carcinogens) donot require further adjustment. Only those PRGs based on non-cancer effects need to beadjusted. Please note that Region 9 PRGs have been recently updated (October 2004).The updated values should be used when revisions to the COPCs selection process areimplemented. In addition, MCLs and Ambient Water Quality Criteria should beconsidered as additional screening criteria for groundwater and surface water COPCselection, respectively. This section also implies that statewide background levels wereused to select COPCs. Please clarify this section to indicate that background was not usedto select COPCs.

Response: Industrial soil PRGs were used for soils and sediments based on the historical siteuse, the future planning and because institutional controls restricting residential use at thesite will be implemented. The PRGs will be compared with the updated numbers in October2004. In addition, MCLs and Ambient Water Quality Criteria will be used to furtherscreening groundwater and surface water COPCs. Available background studies will used inthe screening process since no site-specific background is available ("ElementalConcentration in Soils and other Surficial materials of the Conterminous United States" and"Evaluation of Background Metal Concentration in Ohio Soils").: :ODMA\PCDOCS\CLE VELAND\695127\ 1



Page 17 of40



\ 1. Section 3.3, page 11 of 26: Provide references to document the source of the chemicaland physical property information contained in the report.


12. Section 4.1.4,1st paragraph, page 13 of 26: The selection of COPCs for surface waterand sediment indicates potential site-related impacts to the river. Current exposures mayoccur infrequently, but should be quantified and included in the evaluation. Futureexposures may occur at a higher frequency and intensity should development result in anincrease in attractive potential for the area. Quantify both current and potential futuresurface water and sediment risks to recreational users of the river. The nature of thisexposure pathway should be documented, not simply presumed.


1) City ofElyria has an ordinance prohibiting swimming in Black River;


3) The river is too dangerous for boating due to multiple falls along the river.These justifications will be included in the revised RI report

13. Section 4.1.5, l" bullet, page 13 of 26: Current receptors must be quantitativelyevaluated to determine the magnitude of risk being incurred. It is agreed that futurereceptors are potentially more exposed. However, the finding of elevated risk and hazardto future receptors suggests that current receptors accessing the property are potentially at




Page 18 of 40


Response: See general response # 1.

14. Section 4.1.5,2nd bullet, page 14 of 26: On-site residents should be included as futurereceptors. The quantification of future residential risks will provide information todetermine whether institutional controls preventing future residential development needto be placed on the property.


15. Section 4.1.6,2nd paragraph, page 15 of 26: The quantitative evaluation of industrialand residential groundwater use scenarios is strongly recommended. The suggestedevaluation will provide the basis for decisions concerning groundwater use restrictions, ifnecessary. Also, is the Site located within an Urban Setting Designation (USD) with thestate of Ohio? Having a USD does document the limited potential for future use ofgroundwater.

Response: The site is not located within a USD area. The closest USD is located 13 miles ofthe site. As stated in the risk assessment, there are no water wells wit/tin a one-mile radius ofthe site. In addition, no groundwater municipal water supply systems are located within afour-mile radius of the site, and there are no surface water intakes along the Black Riverwithin IS miles of the site. The City ofElyria Health Department requires that all drinkingwater wells be installed in compliance with Ohio Administrative Code 3701-28 section 10,which states that a water source shall not be located within a minimum of fifty feet of anyknown or possible source of contamination. Therefore, the groundwater ingestion pathwaywas determined to be incomplete. This additional justification will be included in the revisedRI report.






Page 19 of40




Response: Volatiles were defined based on the laboratory analysis list


Response: Agree. Although the outdoor air model used in the risk calculation did not changein the March 2001 Supplemental Guidance, the March 2001 Guidance should have beenreferenced. The values provided in the March 2001 Guidance will be used in the revised Rlreport.20. Section 4.3.2, last paragraph, page 16 of 26: While the text states that the Johnson &









Page 20 of 40

o HEAST





23. Section 5.3, Page 18 of 26: Because the airborne concentrations generated by fate andtransport modeling are in units of mg/m3, it is not necessary to adjust the referenceconcentrations to units of dose. Risk estimation can be performed using the airborne EPC,exposure assumptions to adjust for exposure frequency, duration, and time, and a toxicityvalue (i.e., reference concentration) in units consistent with the EPC. For furtherdiscussion, refer to Appendix 1A (Risk Calculations using Exposure Factors HandbookData and Dose-Response Information from IRIS) in the 1997 Exposure FactorsHandbook. This same approach is applicable to cancer risk calculations using inhalationunit risks.




TABLES

General Comments




Page 21 of40

1. Tables 2 through S, footnotes: Please correct the footnote "MCLs are "MaximumContaminant Levels," not median concentration levels.

Response: The footnote will be revised.








Specific Comments




Page 22 of 40

1. Table 6, Occurrence, Distribution and Selection of COPC in Soil: The risk assessmentfollows standard practices and uses a central tendency value (95% UCL of the mean) toevaluate certain COCs. However, this approach may mask certain areas of highercontamination. For example, Aroclor 1242 was detected at 79 ppm (GP-41, 0-2 feet), andAroclor 1254 was detected at 65 ppm (GP-44,0-2 feet), from the soil sampled along thestorm sewer line. Arsenic was detected in subsurface soil at 228 ppm. At a minimum, aconceptual site model (figures) of the contaminant concentrations in the different media isnecessary, or add a reference to such figures in the Risk Assessment. If activeremediation is the forethought, it may be necessary to characterize these areas of highercontamination to better focus the remedial process.







Response: Table 10 will be revised to define the exposure point as on-site. Samples used forthis exposure point will be included in a footnote. Duplicates mil be added to the calculations.Half of the detection limits were used for non-detects when calculating 95%UCLs.





Page 23 of 40


Table 10 will be revised accordingly for clarity.


Response: Additional justification mil be included in Table 12 to document the reasons foreliminating certain exposure pathways for further quantitative evaluation. The inhalationexposure to volatiles contributed by groundwater was calculated for a future constructionworker. See Attachment C of the Appendix Efor the risk calculations of this exposurepathway.







Page 24 of 40

and the airborne concentration to units of dose (mg/kg-day). The modeled airborneconcentrations can be adjusted for exposure using the receptor specific exposure times,exposure frequencies, and exposure durations. The resulting adjusted airborneconcentrations can be compared directly to the toxicity values (in units of mg/m or[mg/m3]'1) to estimate hazard and cancer risk. Therefore, inhalation rates and bodyweights are not needed to estimate risk and hazard for the air pathways. Please editequations and parameters accordingly.

Response: Agree. However, units of dose instead of unit risks were used in the riskcalculations because of the use ofASTM's indoor air model.


Response: The outdoor and indoor exposure pathways for a future commercial worker wereevaluated separately. The risks for outdoor and indoor scenarios were combined as aconservative approach. Two separate commercial workers will be included in the revised RIreport.





: :ODMA\PCDOCS\CLE VELANDN695127\1



Page 25 of 40


Responses: The source references of Tables 14 and 15 mil be revised to be consistent with thetext in Section 5.1. Surrogates will be used for compounds lacking toxicity values.









Page 26 of 40


Response: Table 14 will be revised to show different uncertainty/modifying factor for differentmedia.


Response: Inhalation reference concentration will be added to Table 14.

17. Tables 14 and 15, general: Inhalation RfCs and unit risks, rather than extrapolated RfDsand inhalation cancer slope factors, are recommended for use in risk estimation. Modeledconcentrations are derived in units of mg/m3. Therefore, RfCs and unit risks are in unitsconsistent with the modeled airborne concentrations and may be used directly withoutextrapolation.





Response: Justifications of using the midpoint of the range of values provided in IRIS for theoral slope factor and unit risk for benzene will be added to Table 15.



: :ODMAVPCDOCS\CLE VEL AND\69512 7\ 1



Page 27 of 40

21. Table 16 (Table 7.1 .RME), Construction worker: It appears that both surface andsubsurface soils were combined for evaluation. It may be more appropriate to evaluate thetwo soil depth intervals separately. Furthermore, the EPCs need to be confirmed. Forexample, aluminum shows an EPC which is the maximum surface soil value. Antimonypresents the EPC for subsurface, yet the surface soil value is higher than the subsurfacevalue.




23. Table 18: For each receptor, any contaminant contributing more than a cancer risk of1E-06 (not IE-OS) and a non cancer hazard quotient of one should appear on this table.Please include any additional COPCs that meet these criteria.

Response: Due to the reasonable future industrial use, a cancer risk level of IE-OS isapplicable for the site, therefore IE-OS is used for COC selection,






Page 28 of 40





General Comments

1. The SLERA does not follow the USEPA 1997 Guidance. In addition to discussing sitebackground, environmental setting, contaminants at the site, contaminant fate andtransport, eco-toxicity, potential receptors, complete exposure pathways, and assessmentand measurement endpoints, and screening level exposure estimates, the SLERA shouldalso include a screening level ecological risk calculation. Typically, the risk calculationderives a hazard quotient (HQ), obtained by dividing the exposure point concentration,such as the maximum concentration for a COPEC, by a toxicity reference value, typicallythe benchmark screening value. Revise tables to include HQs for the COPECs.





Page 29 of 40

2. A scientific/management decision point (SMDP) follows completion of the screeninglevel risk calculation. According to the Guidance, there are only three possible decisionsat his point: 1) is there enough information to conclude negligible risk, 2) moreinformation is needed so the process will continue, or 3) information indicates a potentialfor adverse ecological effects and a more thorough assessment is warranted. The SLERAstates in Section 3.0 that the site is ̂ contaminated with various compounds at levels thatmay be harmful to ecological receptors under conditions of long-term contact Based onthis statement, he SLERA should have concluded that preliminary risk occurs onsite andthat a more thorough assessment is warranted. Instead, the SLERA concluded that nofurther investigation is necessary because there is negligible risk. The basis forconcluding that no further investigation is necessary due to negligible risk is should berevised because the information needed to make such a conclusion is missing. First,though the SLERA speculates that a low temporal site use factor (i.e., a short exposuretime) mitigates risk, there is no quantitative evidence to support this argument. Toolssuch as toxicity tests, bio-accumulation studies, tissue analysis, and food chain modelsshould be used estimate chronic exposures, and then be compared to toxicity referencevalues (TRVs) to determine whether or not a risk is present and to quantify the magnitudeof that risk. Second, the SLERA did not characterize whether ecological receptors are atrisk from acute effects. Given that some exposure point concentrations exceededbenchmarks by two to three orders of magnitude, it is possible that receptors mayexperience acute effects, even during shorter exposure periods. Although the hypothesisthat a low temporal site use factor may eventually be shown to be correct, it has not yetbeen proven. The SLERA concludes that additional investigation is warranted.

Response: Although the 1997guidance states that there are onty 3possible decisionsfollowing a SLERA, there is in fact later guidance from US EPA (ECO Update, June 2001),that allows a fourth possible decision following completion of a SLERA. This fourth decisionis presented on page 5 of the ECO Update, where "tiering" of the ERA is discussed. Withinthe discussion of tiering, the USEPA acknowledges that "Although a decision can be made toproceed with cleanup after any tier of the ERA process, for some sites of relatively small sizeor where the contamination has a sharply defined boundary, it may be preferable to cleanupthe site to the screening values rather than to spend time and resources determining a lessconservative cleanup number." Following completion of the SLERA ("tier 1"), CRS hasdecided not to conduct the baseline ERA, but instead proceed to an evaluation of cleanupoptions due to the small size of the CRS site and the nature and extent of the contamination.We do agree with the comment that the conclusion that there is negligible risk at the site is not

fully supported since quantitative calculations were not conducted. Therefore, the text of therevised SLERA will be changed to acknowledge that the SLERA concluded that there ispotential risk to ecological receptors; however, given the small size of the site, and the natureand location of these COPECs, further ecological evaluation of the site will not be conductedand the screening values will be used in lieu of determining site-specific cleanup numbers forecological receptors.• :ODMA\PCDOCS\CLEVELAND\695127\1



Page 30 of 40

3. As described in the USEP A 1997 Guidance, the purpose of the risk assessment process isto characterize site related risk. Whether or not the general area continues to maintain anurbanized character may impact cleanup levels but it does not affect the type andmagnitude of site related risk. The decision whether or not to proceed with a BaselineEcological Risk Assessment (BERA) should not be made based on future land use, andshould be insulated from any other factors more appropriately considered in riskmanagement steps,







Response: Agree.


Response: Agree.




Page 31 of40

Specific Comments



2. Section 2.1,l" sentence, page 5, Identification of COPECs in Surface Soils: The textreads that samples collected between 0 to 4 feet below ground surface were included insoil screening. Typically, soil screening consists of samples between 0 and 2 feet. Revisesoil screening concentrations.



Response: ECO-SSLs will be given priority when screening soil data. ECO-SSLs were notused in the initial SLERA since there are only 7 compounds that have ECO-SSLs publishedand there are over 100potential COPECs. However, for these 7 compounds, (antimony,barium, beryllium, cadmium, cobalt, lead and dieldrin), the ECO-SSLs will be given priority.Additionally, Region 5 Soil Screening Criteria were used in the SLERA for screening soildata. The Region 5 ESLs are mistakenly referred to as "EDQLs" in Table 1; but in fact, theupdated Region 5 ESLs published in 2003 were utilized for the screening process. TheseRegion 5 ESLs will be given second priority in the soil screening hierarchy. Should both anECO-SSL and a Region 5 ESL be unavailable, then alternative benchmarks, such as thosepublished by Efroymson, et al. (1997), will be used. The tables and text will be updated andcorrected in the revised SLERA.




Page 3 2 of 40


Response: As stated above, ECO-SSLs will be given priority in the soil screening process. Tobe protective of all potential receptors, the lowest screening value mil be used in accordancewith the screening hierarchy specified in response to comment #3 above.











Page 33 of 40

Response: Agree; updated Ohio EPA OMZA standards mil be used in lieu of Ohio EPAOMZM. The text and Table 3 will be revised.

9. Table 1, Soil Screening Levels: There is an error in the screening benchmarkscomparison presented for some COCs - the PCB benchmarks are presented as ppb(jag/kg), but the site concentrations are ppm (mg/kg) and, so, specific Aroclor should notbe screened out of consideration. Also the screening level for 2-hexanone is 1.26E**ppb, and not 8.96E+04 ppb. Please revise the table.

Response: Agree; the tables will be revised as indicated.


Response: Agree; persistent, bioaccumulative chemicals will not be screened out unless thescreening levels are specifically protective of higher trophic level receptors.


Response: Agree; the references will be updated to reflect the correct source.







::ODMA\PCDOCS\CLEVELAND\695127M



Page 34 of 40





General Comments











Page 35 of 40





Specific Comments

1. Section 1.2.4.1,2nd paragraph, page 6 of 35: The last sentence of this paragraph readsthat only GP-16 could be analyzed for the full suite of analytes due to limitedgroundwater. This should be clarified to reflect that this is with respect to the temporarymonitoring wells only. Permanent monitoring wells were evaluated for the full suite ofanalytes.

Response: This Section will be revised to agree with the final Rl Report

2. Section 1.2.5.2,5th paragraph, page 9 of 35: There is no supporting evidence providedfor the statement that Site conditions are favorable for the degradation of SVOCs. Thisevaluation must be discussed for this statement to be considered valid. This comment isthe same as for Section 5 in the RI Report review.

Response: The Section will be made to repeat the RI Report.






Page 36 of 40



5. Section 2.4,2nd paragraph, page 17 of 35: This paragraph states that "modeling predictsthat soil to groundwater leaching may be a potential future issue in the northwest cornerof the site." Results of this modeling are not presented in the RJ report or FS. Datasupporting this conclusion must be provided.







Response: It is not practical to put a fence at the bottom of the steep bank, thus the fence onthis side of the Site is placed at the top of the bank. A statement as to why the fence is notbeing placed at the "perimeter" on this side of the Site will be added to the Report.

9. If the ground water flow is toward the river, it is unclear as to how effective animpermeable barrier layer would be over the 0.5 acres in the northwest corner of the siteto prevent potential leaching to groundwater. The barrier layer in this area could




Page 37 of 40









13. Table 3.2,1st page, under the Deed Restrictions Alternative: EPA does not agree thatoperation and maintenance or monitoring is not required under the ImplementabilityEvaluation. Monitoring and enforcement is important to overall success of any ICs. Animportant aspect to ensure long-term effectiveness of ICs will be periodic monitoring.There needs to be a process after a remedy is in place that routinely evaluates each 1C todetermine: (1) whether the 1C remains in place; and (2) whether it remains protective.


: :ODM A\PCDOCS\CLEVELAND\695127\ 1



Page 3 8 of 40







Response: The cost estimate calculation sheet for the excavation alternative will be included inthe Appendix. At this time, it is not known how much of the soil would be consideredhazardous or non-hazardous. For cost estimating purposes, it was assumed that 75% wouldbe non-hazardous. The cost if all of the soil had to be disposed as hazardous was alsoincluded.




: :ODM A\PCDOCS\CLEVELAND\695127\ 1



Page 39 of 40

Response: The surface of the Site would need to be regraded so that the cap termination atthe perimeter would match existing grade. A statement clarifying this will be added to the text.





Page 40 of 40

ATTACHMENT A

:ODMA\PCDOCS\CLEVELAND\695127\1



Page 1 of40



General Comments

Since the surface runoff was identified as one of the primary means of contaminant migration,the river bank appears to be a likely location of surface soil contamination. For now, only twosoil samples (HA- 4 and HA-S) were taken on the bank on the west side of the Site, headingdown to the river. These sample locations were in close proximity to each other at the south endof the bank. Therefore, it is not feasible to make a determination regarding the river bank fromthese two sampling points. This area needs to be fully evaluated to determine if it must beremediated, and the results of the evaluation included in the RI Report.


Specific Comments


1. Section 2.1.1.1, paragraph 1, page 6 of 29: The draft report reads that a total of 40 soilborings was advanced at the site using direct push technology. Additionally, five surfacesoils borings were also collected from the top of the river bank using a hand auger. Thesample designations were HA01 - HA05. In Section 4.0 (Nature and Extent of Impact) itis stated that a total of fifty soil borings was installed at the site for soil and ground watercharacterization. For consistency, it should be stated in Section 2 that an additional fivesoil borings were installed during phase n of the investigation, which evaluated the sewerline. It is confusing to read in Section 2 that 40 total soil borings were advanced duringthe investigation, and in Section 4 it reads that 50 total borings were installed for soil andground water sampling. Please check and correct to have the numbers agree in thosesections.

Response: A total of 50 soil sampling locations were advanced (GP-1 through GP-45 - direct




Page 2 of40



Response: The text will be amended to clarify that only temporary monitoring point GP-16had sufficient groundwater for analysis besides VOCs and that Monitored NaturalAttenuation parameters were collect at each permanent monitoring well


Response: All temporary monitoring points remain in the ground at the site. The boring logsfor GP-2, GP-9, GP-19, GP-26 and GP-37will be amended. All temporary monitoring pointswill be properly abandoned once site characterization activities are complete.








Page 3 of40



Response: The entire peninsula has been backfilled with various materials over the past 100plus years. In addition, industrial operations have dominated the peninsula far the last 100plus years. There is very little chance that true background samples can be collected, however,this item can be discussed in detail during the site meeting on 20 April 2005.









Page 4 of40





Response: MW-6 is the only significantly impacted permanent welL The impactedgroundwater has not significantly migrated from MW-6 to any of the down-gradientmonitoring wells, which lends credence to natural attenuation at the site. The last sentencewill be changed to "The groundwater VOC analytical results indicated that conditions at theSite are favorable for degradation ".


Response: MW-6 is the only significantly impacted permanent welL The impactedgroundwater has not significantly migrated from MW-6 to any of the down-gradientmonitoring wells, which lends credence to natural attenuation at the site. In addition,SVOCs in groundwater degrade, albeit slower than VOCs. However, there appears tobe an absence of data which can be used to definitively indicate that SVOCs aredegrading in groundwater at the site. The section will be amended to reflect thisresponse.

6.0 RISK ASSESSMENT





Page 5 of 40

cumulative risk of 10"6 and hazard level of 1, 10% of the PRGs were ... This languageshould be changed to read: To ensure the cumulative risk of 10"6 cancer risk or less, and ahazard index of 1.0 or less, PRGs were used for comparison. If the maximumconcentration of a chemical detected at the site, for any specific media, exceeds or isequal to 10~6 cancer risk, or exceeds or is equal to a hazard quotient of 0.1, the chemical isconsidered a COC.


2. The Agency has a regional memorandum for identifying and selecting COCs atSuperfund Sites. The Agency mentioned this memo in previous comments to the workplan. The memo provided was dated November 22, 2002, which should have been usedfor this purpose. It is unclear what is meant by 10% of PRO were used for comparison.

Response: The 10% PRG approach is consistent with what was stated in the November 22,2002 regional memorandum to include cumulative effects by assuming that siteconcentrations that are less than 10% of the PRG will not contribute cumulative risk to withinone significant digit

3. Section 6.1, paragraph 3, 2nd sentence, page 24 of 29: "The anticipated future use ofthe site is to remain commercial and industrial." If this is so, some form of institutionalcontrol (ICs) is required for this site to ensure that it will not be converted to residentialuse, some day down the road. This is so, even if a remediation takes place based onindustrial/commercial use. Therefore, unless ICs are put in place the remediation wouldhave to be based on residential use.


4. Section 6.1, paragraph 3,5th sentence, page 24 of 29: "The potential exposurepathways evaluated . . ." This sentence should be changed to read: The potentialexposure pathways evaluated for the site include soil ingestion, soil dermal contact, theinhalation of soil volatile chemicals to indoor and outdoor air, the inhalation ofgroundwater volatile chemicals to indoor and outdoor air, and groundwater dermalcontact.





Page 6 of40


Response: The U.S. EPA 1996 model was used for the soil volatile chemicals to outdoor airnot the soil volatile chemicals to indoor air. The ASTM model was used to evaluate soil toindoor air pathway. The ASTM model is based on the Johnson and Ettinger model; however,the ASTM model does not include advection. The ASTM model was selected based on thefollowing: 1) a previous study performed by Parsons shows that the modeled concentrationsusing ASTM model were within an order of magnitude of the monitored indoor airconcentrations without indoor/outdoor sources (Parsons, 2000. Baseline Risk AssessmentReport for Areas West of 460-489 Harbor Boulevard in the Vicinity of 511 O'Neil AvenueBelmont, California); and 2) ASTM model is an approved model for other regulatoryprograms. For the potential future residential scenario, the current US EPA's Indoor AirModel will be used for comparison purposes in the revised RI report.

6. • ndSection 6.1, paragraph 5, 2 sentence, page 24 of 29: Risk numbers are given for soilexposures only. Since groundwater volatile chemicals and dermal contact pathways werealso evaluated, why are they excluded from the summary?

Response: The total cancer risk and total hazard index calculated for a future commercialworker and a future construction worker do include groundwater exposure pathways.Therefore, the 1st sentence of the 1st bullet of paragraph 5 will be changed to "The totalcancer risk and total hazard index resulting from exposure to COPCs in soil and groundwaterfor a future commercial worker were calculated to be 3 x Iff* and 23, respectively." The 1stsentence of 2nd bullet of paragraph 5 will be changed to "The total cancer risk and totalhazard index resulting from exposure to COPCs in soil and groundwater for a futureconstruction worker were calculated to be 2 x Iff5 and 3.5, respectively".




1. Section 6.2, page 25 of 29: Based on this paragraph, a claim has been made that there is::ODMA\PCDOCS\CLEVELAND\695127\1



Page 7 of40


Response: The statement made in this paragraph was not meant to imply that "there is nowildlife because the habitat is unsuitable?1. Instead, we were making the point that the siteis so heavily developed for industrial use, that there is very little natural habitat availablefor wildlife to use-especially when considering the terrestrial habitat. In essence, we werefollowing the guidance for evaluating contaminants in soils that is contained on pages 1-5and 1-6 of the ECO-SSL guidance (USEPA, 2 003 a) which states: "An exposure pathway isnot considered complete if natural habitat for ecological receptors is not present and is notexpected to be present in the future" and "Exposure pathways may not be consideredcomplete for ecological receptors if the site is within urban and/or industrialized areaswhere natural habitat and receptors are absent." An exception to this is if there is thepotential for protected species to use the site; however, this is not the case for CRS sincethe Ohio Department of Natural Resources confirmed that no endangered and/orthreatened species occur at or near CRS (refer to Appendix A of the SLERA).Furthermore, we disagree that the site has not been adequately characterized. In additionto the numerous site-specific studies that are detailed in Sections 1 through 3 of the RIreport, a number of other studies have been undertaken by an adjacent property owner(Engelhard Corporation) and by the Ohio EPA (of the Black River) that provide additionalinformation concerning the nature of the area. Therefore, the site and surrounding areahave been well characterized allowing us to make such a conclusion in the SLERA.However, we do agree that a summary of this additional supporting information would behelpful for a person reviewing this document; therefore, a summary of these studies and adetailed habitat map will be included in the revised SLERA to support this claim.


Response: Additional detail of the dams and other sources of potential impact to aquatic life,specifically in the vicinity of CRS, will be provided in the revised report




Page 8 of40

3. In addition, there are a number of inorganic and organic Contaminants of PotentialEcological Concern (COPECs) whose maximum concentrations exceed screeningbenchmark values (thus suggesting the possibility of ecological risk). These exceedencescontribute to the uncertainty over the claim that nearby dams is the limiting factors forviable and sustained benthic invertebrate communities. Please provide evidence thatsupports the claim that it is the dams, and other physical stressors, or whether, it is thechemical stressors that are impacting the benthic communities.



Table 1. Comparison of PRGs and Eco-SSLs (where available); units for all values: mg/kgCOPEC

AntimonyBarium

BerylliumCadmium

CobaltLead

Dieldrin

PRO

5 (plant)283


woodcock)20 (plant)

40.5(woodcock)

n.a.


78330

40140

1700

Eco-SSL(plants)

32

110

Eco-SSL(birds)

1.0

19016

0.0016

Eco-SSL(mammals)

0.291000

360.38

24059

0.00028





Page 9 of40

two available ECO-SSLsfor barium. Also, for compounds that lack both an ECO-SSL and aRegion 5 ESL, the soil PRG will be used as an alternative screening value.


Response: Agree; site-specific soil pH data will be collected. If the soil pH is greater than 5.5,aluminum will be removed as a compound of concern in soils.

6. The report incorrectly states that minimizing human health risk "should be adequatelyprotective for the ecological receptors that might inhabit such an urbanized environment."However, because effects' levels are different between ecological and human receptors,it does not necessarily follow that ecological receptors will be protected at contaminantlevels that are protective of human health. Contaminant levels should be screened againstthe appropriate ecological screening values. If there are levels of COPECs that exceedno-effects levels (the level of contamination below which no adverse effects areexpected), then ecological receptors are potentially at risk, regardless if the contaminantlevels are below levels of human receptors.

Response: We agree that ecological effects may still occur even if the risk to human health isminimized; however, this statement was made to assist the risk managers when consideringthe current and planned future use of the site, which is industrial In fact, for a lot of smallindustrial sites such as CRS, wildlife is actively discouraged from utilizing the site in order toprevent attracting unwanted vectors (nuisance birds, rodents and insects). Nevertheless, thetext will be revised to reflect that not all ecological receptors may be protected even if humanhealth risks are minimized.


Response: See also responses to comments #2 and #3 above regarding the supplementalinformation that will be provided in the revised SLERA concerning the Black River. Forinstance, the river frontage for the site is just over 400 feet and most of this frontage is verysteep and rocky. Thus, there is little suitable habitat available for flsh species to nest and/orforage adjacent to the site. Additionally, one of the primary exposure pathways for fish isdirect contact with surface water; and based on the surface water screening results, surfacewater is not impacted at the site. Therefore, if fish are not present, it would appear to be morelikely due to the lack of suitable habitat versus chemical stressors.




Page 10 of40


Response: As stated previously in response to comment #1 above, there is very little naturalhabitat available at the site; therefore, most exposure pathways are not complete, especially fortransient animals that are associated with the terrestrial areas of the site. For example, theentire site is only 2.5 acres in size, and more than 75% of this area has been physically altered(buildings, paved, etc.). Additionally, when comparing what little site habitat there is tohabitats available on nearby properties, it is not evident that the CRS site has any areas thatwould be considered preferentially attractive to wildlife. Despite this fact, soils, surface waterand sediments were evaluated in this SLERA in order to determine the risk to all potentialreceptors coming into contact with these media—if even for only a brief period of time. Thescreening values used in the SLERA are based on chronic exposures for the most sensitiveplants and animals and they do not consider the amount of time spent by the receptor at a site(Le., the receptors are considered to spend their entire lives at the site). Therefore, thepotential risk to urban animals was not dismissed and is actually likely to be overestimated.Furthermore, we disagree that domesticated animals (Le., cats and dogs) should be consideredecological receptors as suggested in this comment. First, the site is and will be fenced.Second, domesticated animals should be leashed (the City ofElyria has a "leash law");therefore, these animals would not have access to the site. Lastly, feral cats and dogs areconsidered to be nuisance and/or potentially dangerous animals, and would have to beremoved from the site as soon as they are discovered.



bullet, page 25 of 29), it is stated that the total cancer risk and Hazard Index (HI) fromexposure to COPC in soil for a future commercial worker was calculated to be SxlO"4 and23, respectively, However, in Section 7.1.3, these calculations for a future commercialworker were reportedly calculated to be 4x10^ and 10, respectively, for total cancer riskand HI. Clarify or correct.




Page 11 of40

Response: Agree. The total cancer risk and hazard index for a future commercial workershould be consistent with the risk assessment results in Section 6. The sentence in Section 7will be changed accordingly.2. Section 7.1.3,2nd paragraph, page 27 of 29: The COCs are not consistent in their





Section 6 of the report were listed as 2 x 10~5 and 3, respectively. In Section?. 1.3 for thisexposure scenario, the total cancer risk and HI is listed as 4 x 10"5 and 8 respectively.The COCs for this scenario listed in Section 6 were listed as benzo(a)pyrene,dibenzo(a,h)anthracene, and TCE. However, in Section 7.1.3, the COCs for the futureconstruction worker were antimony, benzo(a)pyrene, PCE, TCE, and xylenes. Pleaseclarify these or correct discrepancies.


5. Regarding the potential exposure to a future trespasser, although the total cancer riskand HI were below the targets of the 10"5 and 1 respectively, but the HI was different forthis scenario in Sections 6 and 7. The HI for this potential exposure scenario was listedas 0.3 in Section 6, but listed as 0.7 in Section 7.1.3. Please clarify or correct.


TABLES





Page 12 of40


Response: Table 4-1 will be amended to reflect the comment.




General Comments


Response: The tables will be amended to reflect the comment.




Specific Comments



Response: Agree with comment



Page 13 of40


General Comments

1. Several of the data validation memos refer to a document called the EDD for specificdetails of qualified results. This document must be included with the RI report, or thespecific details of qualified results must be reported.





General Comments



2. The existence of background monitoring wells and upgradient surface water and sedimentsamples are briefly mentioned. However, there is no further discussion of siteconcentrations relative to background or reference. This type of discussion is importantfor naturally occurring materials and could provide important information upon whichrisk management decisions can be made. Background data for all media, if available,should be included and discussed.




Page 14 of40

Response: Agree. The entire peninsula has been backfilled with various materials over thepast 100 plus years. In addition, industrial operations have dominated the peninsula for thelast 100 plus years. There is very little chance that true background samples can be collected^however, this item can be discussed in detail during the site meeting on 20 April 2005.

Specific Comments

1. Section 1, Executive Summary, paragraph 3, page 1 of 26: The carcinogenic risk goalof 1 xlO"5 for the site is more protective at this stage of the process when assessing riskversus the risk range recommended by the National Contingency Plan of 1 x 10^ through1 x 10"6. When setting remedial levels in the Feasibility Study (FS), and beyond, EPA'spolicy recommends a point of departure of 1 xlO"6, which is more protective at the FSstage.

Response: Agree. Appropriate Remedial levels for the risk levels ofl x Iff4 and 1 x Iff6 milbe presented in the FSfor risk management purposes.

2. Section 2.1, paragraph 3, page 2 of 26: Please provide additional detail regarding theEast Branch of the Black River that borders the site. Is it used for recreational purposessuch as boating or fishing? Is it deep enough to accommodate swimming? Or wouldwading be the primary type of exposure expected? Does the surface water depth increaserapidly with distance from the shore? Or is a gradual increase in surface water depthtypically noted? Is the surface water rapidly moving or slowly meandering? In addition,please add the distance to the nearest residences and describe whether schools or day carefacilities are present in the vicinity of the site. This information would provide valuablecontext for the exposure assessment portion of the risk assessment.






Page 15 of40


Response: There are only four drum storage areas. The text mil be revised. Instead ofconsidering site shallow groundwater as a potential area of concern, a discussion of thecontaminants in groundwater (shallow and deep) will be included.


Response: ODNR was contacted regarding the existence of water wells within a '/2-mile radiusof the site. No wells were identified within this search radius. Additionally, the City ofElyriaPublic Utility Service was contacted for information regarding any private wells in the area.The Public Utility Service informed Parsons that city water has been provided to the area forover SO years. The City has also has rule and regulations to prohibit the installation of privatewater wells.

5. Section 3.1,2nd bullet, page 8 of 26: Please provide the depth of standing surfacewater at each sediment collection point. Also, indicate the distance from shore for each ofthe sediment collection points. Sediment samples used in a human health risk assessmentshould be accessible to humans, considering depth of overlying water and distance fromshore.






Page 16 of 40


Response: Data were validated. Discussions on overall quality and suitability of the data forrisk assessment purposes will be added in the revised RI report.





9. Section 3.2.1, page 10 of 26: This section states that Region 9 residential soil and tapwater risk-based PRGs were used as screening criteria for the selection of COPCs. Theuse of residential PRGs to generate a conservative list of COPCs for both soil andsediment is consistent with 2004 Ohio EPA and USEPA guidance. However, it appearsthat industrial soil PRGs were used for soils and sediments. Please clarify and correct, asappropriate. In addition, Region 9 PRGs (set at a cancer risk of 1E-06 for carcinogens) donot require further adjustment. Only those PRGs based on non-cancer effects need to beadjusted. Please note that Region 9 PRGs have been recently updated (October 2004).The updated values should be used when revisions to the COPCs selection process areimplemented. In addition, MCLs and Ambient Water Quality Criteria should beconsidered as additional screening criteria for groundwater and surface water COPCselection, respectively. This section also implies that statewide background levels wereused to select COPCs. Please clarify this section to indicate that background was not usedto select COPCs.

Response: Industrial soil PRGs were used for soils and sediments based on the historical siteuse, the future planning and because institutional controls restricting residential use at thesite will be implemented. The PRGs will be compared with the updated numbers in October2004. In addition, MCLs and Ambient Water Quality Criteria will be used to furtherscreening groundwater and surface water COPCs. A vailable background studies will used inthe screening process since no site-specific background is available ("ElementalConcentration in Soils and other Surficial materials of the Conterminous United States" and"Evaluation of Background Metal Concentration in Ohio Soils").: :ODMA\PCDOCS\CLEVELAND\695127\1



Page 17 of40



11. Section 3.3, page 11 of 26: Provide references to document the source of the chemicaland physical property information contained in the report.


12. Section 4.1.4,1** paragraph, page 13 of 26: The selection of COPCs for surface waterand sediment indicates potential site-related impacts to the river. Current exposures mayoccur infrequently, but should be quantified and included in the evaluation. Futureexposures may occur at a higher frequency and intensity should development result in anincrease in attractive potential for the area. Quantify both current and potential futuresurface water and sediment risks to recreational users of the river. The nature of thisexposure pathway should be documented, not simply presumed.


1) City ofElyrta has an ordinance prohibiting swimming in Black River;


3) The river is too dangerous for boating due to multiple falls along the river.These justifications will be included in the revised RI report

13. Section 4.1.5, l" bullet, page 13 of 26: Current receptors must be quantitativelyevaluated to determine the magnitude of risk being incurred. It is agreed that futurereceptors are potentially more exposed. However, the finding of elevated risk and hazardto future receptors suggests that current receptors accessing the property are potentially at




Page 18 of40


Response: See general response # 1.

14. Section 4.1.5, 2nd bullet, page 14 of 26: On-site residents should be included as futurereceptors. The quantification of future residential risks will provide information todetermine whether institutional controls preventing future residential development needto be placed on the property.


15. Section 4.1.6,2"d paragraph, page 15 of 26: The quantitative evaluation of industrialand residential groundwater use scenarios is strongly recommended The suggestedevaluation will provide the basis for decisions concerning groundwater use restrictions, ifnecessary. Also, is the Site located within an Urban Setting Designation (USD) with thestate of Ohio? Having a USD does document the limited potential for future use ofgroundwater.

Response: The site is not located within a USD area. The closest USD is located 13 miles ofthe site. As stated in the risk assessment, there are no water wells within a one-mile radius ofthe site. In addition, no groundwater municipal water supply systems are located within afour-mile radius of the site, and there are no surface water intakes along the Black Riverwithin 15 miles of the site. The City ofEtyria Health Department requires that all drinkingwater wells be installed in compliance with Ohio Administrative Code 3701-28 section 10,which states that a water source shall not be located within a minimum of fifty feet of anyknown or possible source of contamination. Therefore, the groundwater ingestion pathwaywas determined to be incomplete. This additional justification will be included in the revisedRI report,






Page 19 of 40




Response: Volatiles were defined based on the laboratory analysis list.


Response: Agree. Although the outdoor air model used in the risk calculation did not changein the March 2001 Supplemental Guidance, the March 2001 Guidance should have beenreferenced. The values provided in the March 2001 Guidance will be used in the revised Rlreport.20. Section 4.3.2, last paragraph, page 16 of 26: While the text states that the Johnson &









Page 20 of 40

o HEAST





23. Section 5.3, Page 18 of 26: Because the airborne concentrations generated by fate andtransport modeling are in units of mg/rn3, it is not necessary to adjust the referenceconcentrations to units of dose. Risk estimation can be performed using the airborne EPC,exposure assumptions to adjust for exposure frequency, duration, and time, and a toxicityvalue (i.e., reference concentration) in units consistent with the EPC. For furtherdiscussion, refer to Appendix 1A (Risk Calculations using Exposure Factors HandbookData and Dose-Response Information from IRIS) in the 1997 Exposure FactorsHandbook. This same approach is applicable to cancer risk calculations using inhalationunit risks.




TABLES

General Comments




Page 21 of40

1. Tables 2 through 5, footnotes: Please correct the footnote "MCLs are "MaximumContaminant Levels," not median concentration levels.

Response: The footnote will be revised.








Specific Comments




Page 22 of 40

1. Table 6, Occurrence, Distribution and Selection of COPC in Soil: The risk assessmentfollows standard practices and uses a central tendency value (95% UCL of the mean) toevaluate certain COCs. However, this approach may mask certain areas of highercontamination. For example, Aroclor 1242 was detected at 79 ppm (GP-41,0-2 feet), andAroclor 1254 was detected at 65 ppm (GP-44,0-2 feet), from the soil sampled along thestorm sewer line. Arsenic was detected in subsurface soil at 228 ppm. At a minimum, aconceptual site model (figures) of the contaminant concentrations in the different media isnecessary, or add a reference to such figures in the Risk Assessment. If activeremediation is the forethought, it may be necessary to characterize these areas of highercontamination to better focus the remedial process.







Response: Table 10 will be revised to define the exposure point as on-site. Samples used forthis exposure point will be included in a footnote. Duplicates will be added to the calculations.Half of the detection limits were used for non-detects when calculating 95%UCLs.





Page 23 of 40


Table 10 mil be revised accordingly for clarity.


Response: Additional justification will be included in Table 12 to document the reasons foreliminating certain exposure pathways for further quantitative evaluation. The inhalationexposure to volatiles contributed by groundwater was calculated for a future constructionworker. See Attachment C of the Appendix Efor the risk calculations of this exposurepathway.







Page 24 of 40

and the airborne concentration to units of dose (mg/kg-day). The modeled airborneconcentrations can be adjusted for exposure using the receptor specific exposure times,exposure frequencies, and exposure durations. The resulting adjusted airborneconcentrations can be compared directly to the toxicity values (in units of mg/m3 or[mg/m3]"1) to estimate hazard and cancer risk. Therefore, inhalation rates and bodyweights are not needed to estimate risk and hazard for the air pathways. Please editequations and parameters accordingly.

Response: Agree. However, units of dose instead of unit risks were used in the riskcalculations because of the use ofASTM's indoor air model


Response: The outdoor and indoor exposure pathways for a future commercial worker wereevaluated separately. The risks for outdoor and indoor scenarios were combined as aconservative approach. Two separate commercial workers will be included in the revised RIreport.








Page 25 of 40


Responses: The source references of Tables 14 and 15 will be revised to be consistent with thetext in Section 5.1. Surrogates will be used for compounds lacking toxicity values.









Page 26 of 40


Response: Table 14 will be revised to show different uncertainty/modifying factor for differentmedia.


Response: Inhalation reference concentration will be added to Table 14.

17. Tables 14 and 15, general: Inhalation RfCs and unit risks, rather than extrapolated RfDsand inhalation cancer slope factors, are recommended for use in risk estimation. Modeledconcentrations are derived in units of mg/m3. Therefore, RfCs and unit risks are in unitsconsistent with the modeled airborne concentrations and may be used directly withoutextrapolation.





Response: Justifications of using the midpoint of the range of values provided in IRIS for theoral slope factor and unit risk for benzene will be added to Table 15.






Page 27 of 40

21. Table 16 (Table 7.1.RME), Construction worker: It appears that both surface andsubsurface soils were combined for evaluation. It may be more appropriate to evaluate thetwo soil depth intervals separately. Furthermore, the EPCs need to be confirmed. Forexample, aluminum shows an EPC which is the maximum surface soil value. Antimonypresents the EPC for subsurface, yet the surface soil value is higher than the subsurfacevalue.




23. Table 18: For each receptor, any contaminant contributing more than a cancer risk of1E-06 (not 1E-05) and a non cancer hazard quotient of one should appear on this table.Please include any additional COPCs that meet these criteria.

Response: Due to the reasonable future industrial use, a cancer risk level of IE-OS isapplicable for the site, therefore IE-OS is used for COC selection.






Page 28 of 40





General Comments

1. The SLERA does not follow the USEPA 1997 Guidance, hi addition to discussing sitebackground, environmental setting, contaminants at the site, contaminant fate andtransport, eco-toxicity, potential receptors, complete exposure pathways, and assessmentand measurement endpoints, and screening level exposure estimates, the SLERA shouldalso include a screening level ecological risk calculation. Typically, the risk calculationderives a hazard quotient (HQ), obtained by dividing the exposure point concentration,such as the maximum concentration for a COPEC, by a toxicity reference value, typicallythe benchmark screening value. Revise tables to include HQs for the COPECs.





Page 29 of 40

2. A scientific/management decision point (SMDP) follows completion of the screeninglevel risk calculation. According to the Guidance, there are only three possible decisionsat his point: 1) is there enough information to conclude negligible risk, 2) moreinformation is needed so the process will continue, or 3) information indicates a potentialfor adverse ecological effects and a more thorough assessment is warranted. The SLERAstates in Section 3.0 that the site is Acontaminated with various compounds at levels thatmay be harmful to ecological receptors under conditions of long-term contact Based onthis statement, he SLERA should have concluded that preliminary risk occurs onsite andthat a more thorough assessment is warranted. Instead, the SLERA concluded that nofurther investigation is necessary because there is negligible risk. The basis forconcluding that no further investigation is necessary due to negligible risk is should berevised because the information needed to make such a conclusion is missing. First,though the SLERA speculates that a low temporal site use factor (i.e., a short exposuretime) mitigates risk, there is no quantitative evidence to support this argument. Toolssuch as toxicity tests, bio-accumulation studies, tissue analysis, and food chain modelsshould be used estimate chronic exposures, and then be compared to toxicity referencevalues (TRVs) to determine whether or not a risk is present and to quantify the magnitudeof that risk. Second, the SLERA did not characterize whether ecological receptors are atrisk from acute effects. Given that some exposure point concentrations exceededbenchmarks by two to three orders of magnitude, it is possible that receptors mayexperience acute effects, even during shorter exposure periods. Although the hypothesisthat a low temporal site use factor may eventually be shown to be correct, it has not yetbeen proven. The SLERA concludes that additional investigation is warranted.

Response: Although the 1997guidance states that there are only 3possible decisionsfollowing a SLERA, there is in fact later guidance from USEPA (ECO Update, June 2001),that allows a fourth possible decision following completion of a SLERA. This fourth decisionis presented on page 5 of the ECO Update, where "tiering" of the ERA is discussed. Withinthe discussion of tiering, the USEPA acknowledges that "Although a decision can be made toproceed with cleanup after any tier of the ERA process, for some sites of relatively small sizeor where the contamination has a sharply defined boundary, it may be preferable to cleanupthe site to the screening values rather than to spend time and resources determining a lessconservative cleanup number." Following completion of the SLERA ("tier 1"), CRS hasdecided not to conduct the baseline ERA, but instead proceed to an evaluation of cleanupoptions due to the small size of the CRS site and the nature and extent of the contamination.We do agree with the comment that the conclusion that there is negligible risk at the site is not

fully supported since quantitative calculations were not conducted. Therefore, the text of therevised SLERA will be changed to acknowledge that the SLERA concluded that there ispotential risk to ecological receptors; however, given the small size of the site, and the natureand location of these COPECs, further ecological evaluation of the site will not be conductedand the screening values will be used in lieu of determining site-specific cleanup numbers forecological receptors.: :ODMA\PCDOCS\CLEVELAND\695127\1



Page 30 of 40

3. As described in the USEPA 1997 Guidance, the purpose of the risk assessment process isto characterize site related risk. Whether or not the general area continues to maintain anurbanized character may impact cleanup levels but it does not affect the type andmagnitude of site related risk. The decision whether or not to proceed with a BaselineEcological Risk Assessment (BERA) should not be made based on future land use, andshould be insulated from any other factors more appropriately considered in riskmanagement steps.







Response: Agree.


Response: Agree.




Page 31 of40

Specific Comments



2. Section 2.1,1st sentence, page 5, Identification of COPECs in Surface Soils: The textreads that samples collected between 0 to 4 feet below ground surface were included insoil screening. Typically, soil screening consists of samples between 0 and 2 feet Revisesoil screening concentrations.



Response: ECO-SSLs will be given priority when screening soil data. ECO-SSLs were notused in the initial SLERA since there are only 7 compounds that have ECO-SSLs publishedand there are over 100potential COPECs. However, for these 7 compounds, (antimony,barium, beryllium, cadmium, cobalt, lead and dieldrin), the ECO-SSLs will be given priority.Additionally, Region 5 Soil Screening Criteria were used in the SLERA for screening soildata. The Region 5 ESLs are mistakenly referred to as "EDQLs" in Table 1; but in fact, theupdated Region 5 ESLs published in 2003 were utilized for the screening process. TheseRegion 5 ESLs will be given second priority in the soil screening hierarchy. Should both anECO-SSL and a Region 5 ESL be unavailable, then alternative benchmarks, such as thosepublished by Efroymson, et. al. (1997), will be used. The tables and text will be updated andcorrected in the revised SLERA.

:: ODMA\PCDOCS\CLE VELAND\695127\ 1



Page 32 of 40


Response: As stated above, ECO-SSLs will be given priority in the soil screening process. Tobe protective of all potential receptors, the lowest screening value will be used in accordancewith the screening hierarchy specified in response to comment #3 above.











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Response: Agree; updated Ohio EPA OMZA standards will be used in lieu of Ohio EPAOMZM. The text and Table 3 will be revised.

9. Table 1, Soil Screening Levels: There is an error in the screening benchmarkscomparison presented for some COCs - the PCB benchmarks are presented as ppb(Hg/kg), but the site concentrations are ppm (mg/kg) and, so, specific Aroclor should notbe screened out of consideration. Also the screening level for 2-hexanone is 1.26E404

ppb, and not 8.96E*04 ppb. Please revise the table.

Response: Agree; the tables will be revised as indicated.


Response: Agree; persistent, bioaccumulative chemicals will not be screened out unless thescreening levels are specifically protective of higher trophic level receptors.


Response: Agree; the references will be updated to reflect the correct source.







:: ODMA\PCDOCS\CLEVELAND\695127\1



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General Comments











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Specific Comments

1. Section 1.2.4.1,2nd paragraph, page 6 of 35: The last sentence of this paragraph readsthat only GP-16 could be analyzed for the full suite of analytes due to limitedgroundwater. This should be clarified to reflect that this is with respect to the temporarymonitoring wells only. Permanent monitoring wells were evaluated for the full suite ofanalytes.

Response: This Section will be revised to agree with the final RI Report

2. Section 1.2.5.2,5th paragraph, page 9 of 35: There is no supporting evidence providedfor the statement that Site conditions are favorable for the degradation of SVOCs. Thisevaluation must be discussed for this statement to be considered valid. This comment isthe same as for Section 5 in the RI Report review.

Response: The Section will be made to repeat the RI Report.






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5. Section 2.4,2nd paragraph, page 17 of 35: This paragraph states that "modeling predictsthat soil to groundwater leaching may be a potential future issue in the northwest comerof the site." Results of this modeling are not presented in the RI report or FS. Datasupporting this conclusion must be provided.







Response: It is not practical to put a fence at the bottom of the steep bank, thus the fence onthis side of the Site is placed at the top of the bank, A statement as to why the fence is notbeing placed at the "perimeter" on this side of the Site will be added to the Report.

9. If the ground water flow is toward the river, it is unclear as to how effective animpermeable barrier layer would be over the 0.5 acres in the northwest corner of the siteto prevent potential leaching to groundwater. The barrier layer in this area could




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13. Table 3.2, 1st page, under the Deed Restrictions Alternative: EPA does not agree thatoperation and maintenance or monitoring is not required under the ImplementabilitvEvaluation. Monitoring and enforcement is important to overall success of any ICs. Animportant aspect to ensure long-term effectiveness of ICs will be periodic monitoring.There needs to be a process after a remedy is in place that routinely evaluates each 1C todetermine: (1) whether the 1C remains in place; and (2) whether it remains protective.





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Response: The cost estimate calculation sheet for the excavation alternative will be included inthe Appendix. At this time, it is not known how much of the soil would be consideredhazardous or non-hazardous. For cost estimating purposes, it was assumed that 75% wouldbe non-hazardous. The cost if all of the soil had to be disposed as hazardous was alsoincluded.







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Response: The surface of the Site would need to be regraded so that the cap termination atthe perimeter would match existing grade. A statement clarifying this will be added to the text.





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ATTACHMENT A

:ODMA\PCDOCS\CLEVELAND\695127\1

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