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us EPA RECORDS CENTER REGION 5
^ ARCADIS Infrastructure • Water • Environment • Buildings
430104
Ms. Sheila Desai Remedial Project Manager U.S. Environmental Protection Agency Region V 77 West Jackson Boulevard Chicago IL 60604-3590
Subject:
Response to the June 27, 2011 U.S. Environmental Protection Agency (U.S.EPA) and Illinois Environmental Protection Agency (lEPA) Human Health-Related Comments on the April 8, 2011 Draft Feasibility Study (FS) for the Old American Zinc Plant Site, Fairmont City, Illinois
ARCADIS U.S., Inc.
2 Executive Drive
Suite 303
Chelmsford
Massachusetts 01824
Tel 978 937 9999
Fax 978 937 7555
www.arcadis-us.com
ENVIRONMENTAL
Dear Ms. Desai:
On behalf of Blue Tee Corp. (Blue Tee), please find the attached responses to the
human health-related comments provided in the June 27, 2011 comment letter on
the April 8, 2011 Draft Feasibility Study (FS) for the Old American Zinc Plant Site,
Fairmont City, Illinois (the Site). As agreed at the July 6, 2011 meeting, written
responses to the comments related to the development of the human health
preliminary cleanup goals (PCGs) and the human health risk assessment results are
addressed separately from those previously submitted to you on July 20, 2011. With
this submittal, responses have been prepared for all comments in the June 27, 2011
comment letter. It was agreed at the July 6, 2011 meeting that after U.S.EPA and
lEPA had a chance to review all of the responses, a meeting or conference call
would be scheduled to discuss any remaining issues prior to determining the date for
submission of the revised FS.
If you have any questions or concerns on the attached responses to comments
please feel free to call me at 978-937-9999 or Gary Uphoff at 970-225-6400.
Date:
August 3, 2011
Contact:
Barbara Pugh
Phone:
978.937.9999 Ext. 329
Email:
Our ref:
ME000140.0001
Sincerely,
ARCADIS U.S., Inc.
Barbara Pugh Senior Scientist-Risk Assessor
Copies: Doyle Wilson, lEPA
Rachael Grand, CH2M Hill
Terrance Gileo Faye, Babst, Calland, Clements & Zomnir
Gary Uphoff, EMS
Jerry Ripp, Goldfields
Paul Anderson, ARCADIS Patricia Thomson, ENTACT LLC
Imagine the result letter_desar_8-2-11 .docx
8
Response to U.S. Environmental Protection Agency (USEPA) and Illinois EPA (lEPA) Comments on the April 8, 2011 Draft Feasibility Study Report (FS); Old American Zinc Plant Site; Fairmont City, Illinois
Responses to USEPA and lEPA June 27, 2011 General Comments on Appendix C (Derivation of Preliminary Cleanup Goals) to the April 8, 2011 Draft FS
1. A relative absorption factor (RAF) of 0.51 cannot be used for arsenic. Rather, the draft default bioaccessibility value of 60% may be used based on the most recent information available from U.S. EPA's Technical Review Workgroup for Arsenic Bioavailability (see Attachment). Please revise all calculated PCGs for arsenic accordingly and modify all text and tables.
Response: The draft default bioaccessibility value ofO. 6 will be used as a RAF for arsenic. All relevant tables and text in Appendix C and FS Section 3.0 will be revised accordingly.
2. The updated lead model cannot be used for exposure frequencies less than 90 days/year (see Frequent Questions from Risk Assessors on the Adult Lead Methodology [ALM] located at http://www.epa.gov/superfund/health/contaminants/ lead/almfaq.htm). Therefore, recalculate the lead PCG based on 90 days/year for recreators and construction workers and modify all text and tables accordingly.
Response: The lead PCG protective of recreators and construction/utility workers will be revised based on the minimum allowed exposure frequency of 90 days. All relevant tables and text in Appendix C and FS Section 3.0 will be revised accordingly.
3. Overall PCGs for residential, recreational, and commercial/industrial land uses should be identified, taking into account the PCGs for construction workers. The lower of the residential and construction worker PCGs should be identified for residential land use. The lower of the recreational and construction worker PCGs should be identified for recreational land use. The lower of the commercial/industrial and construction worker PCGs should be identified for commercial/industrial land use.
Response: The PCGs were developed as stated in the comment. The text and tables in Section 3 and Appendix C will be revised to clearly demonstrate this.
A. Add text and footnotes on tables indicating that construction worker PCGs (with the exception of lead which are based on 90 days) are based on 30-day exposures and longer exposures will warrant lower PCGs.
Response: All relevant tables in Appendix C and FS Section 3.0 will be revised to include the following statements:
"For all COIbut lead, the PCGs for construction worker are based on the assumption of a 30-day total exposure. Lead PCG is based on a 90-day total exposure. Alternative exposure durations for the construction worker scenario will warrant a re-evaluation of the soil PCGs."
It is noted that the PCGs based on the 30-day construction worker scenario for all compounds of interest with the exception of the lead (which is based on a 90-day exposure duration per General Comment 2) are greater than the PCGs for all other receptors.
Augusta, 2011
Response to U.S. EPA and lEPA Comments on the April 8, 2011 Draft Feasibility Study Report (FS); Old American Zinc Plant Site; Fairmont City, Illinois
5. All tables are missing units; add units to all tables.
Response: All relevant tables in Appendix C and FS Section 3.0 will be reviewed and revised accordingly.
6. Remove statements regarding recommended PCGs from all text and tables; U.S. EPA and Illinois EPA are the risk managers, not Blue Tee, and will identify the final PCGs.
Response (as written in the July 19, 2011 response): In the U.S.EPA January 19, 2011 Approval with Modifications letter. Comment 3 and Comment 9 specifically requested that PCGs be developed for all COCs and COPECs and the PCGs to be included in the FS. This comment contradicts these earlier instructions. In addition, recommended PCGs are necessary for estimating volumes and assigning appropriate costs as part of the FS process. The FS does not state these are the final PCGs but merely provides the recommended PCGs along with the supporting technical basis used in the development of these numbers.
1. The "tar material" contains volatile constituents that may impact indoor air if buildings are constructed near or on the tar material. The calculated PCGs do not account for vapor intrusion impacts. Add text stating that tar material PCGs are not protective of indoor air vapor intrusion, and address how fiiture indoor air impacts will be prevented.
Response (as written in the July 19, 2011 response): As indicated in the Sections 4.5.1 (2" bullet), 4.6.1 (third bullet), 4.7.1 (third bullet) and 4.8.1 (first bullet) all buried tarry material would be removed under all action alternatives. Therefore, there is no need to determine if the PCGs are protective of indoor air vapor intrusion or to address future indoor air impacts.
8. A RAF of 0.43 cannot be used for calculating PCGs for PAHs in tar material (it was used according to Attachment 1 Table 26). Recalculate the PCGs based on a RAF of 1, and change all text and associated tables.
Response: Although an RAF of 1 is an overestimate of the potential bioaccumulation of PAHs (see Attachment 2 to Appendix C), the PCGs for the PAHs in tar material will be revised using an RAF of 1. All relevant tables and text in Appendix C and FS Section 3.0 will be revised accordingly.
Response to Comments on the Responses to U.S. EPA Approved Modiflcations for the Draft Final Alternative Array Document
Specific Comments
71. Table 3-1: The PCGs should be based on 10-6 not 10-4 risk level.
Response: PCGs were derived for 3 different cancer risk levels (1x10' 1x10' and 1x10') and are presented in Appendix C to the FS. Table 3-1 has been revised to include this information and is attached to this response letter. For the purpose of estimating volumes and assigning appropriate costs as part of the FS process, recommended PCGs were based
2 Augusts, 2011
Response to U.S. EPA and lEPA Comments on the April 8, 2011 Draft Feasibility Study Report (FS); Old American Zinc Plant Site; Fairmont City, Illinois
on the lower of the noncancer PCG and the cancer PCG at the IxW* target risk limit. The FS does not state these are the final PCGs but merely provides the recommended PCGs along with the supporting technical basis used in the development of these numbers. See Response to Specific Comment 85.
12.2) Table 3-2: Explain all footnotes and spell out abbreviation, i.e. superscript 3.
Response: Section 3 tables will be reviewed and revised.
72. b) The PCGs should be based on 10-6 not 10-4 risk level.
Response: See Response to Specific Comment 71.
72. c) Why are the PCGs for the metals not the same as those listed in Table 3-1?
Response: Section 3 tables 3-1 and 3-2 have been revised incorporating all changes refiected in this response letter and are attached to this document.
72. d) The table lists 893,000 CYs on line 2. What is included in this value?
Response: The comment is not clear as no such value was found in Table 3-2 (as presented in the FS dated April 6, 2011; pdf version).
85. Appendix C: The PCG calculations didn't include the changes in Mr. Ron Murawski's December 3, 2010 letter to Mr. Gary Uphoff. For example, some of the changes to the FS required by this letter were: a)to evaluate and provide cost estimates for an array of remedial altematives within the 10-4 eind 10-6 risk range; b)the relative absorption value for arsenic was to be 1; c) and exposure to soil for residential exposures was to be 350 days per year.
Response to 85 a: This comment relates only to arsenic as: 1) the cadmium PCG based on noncancer effects is lower than that for cancer effects at all target risk levels and 2) all tar material identified at the Facility Area will be removed as part of all action altematives. The arsenic PCG based on a lE-04 cancer risk limit is higher than the PCG based on the noncancer toxicity value; all other calculated arsenic PCGs (based on lE-05 and lE-06 cancer risk limits) are lower than the PCG based on non-cancer toxicity value, but are below the Illinois EPA background level of arsenic (11 mg/kg). Because remediation of soil to levels below background is not a requirement under CERCLA, an evaluation and cost estimates associated with remediating arsenic to background levels in soil will be included in the revised FS.
Response to 85 b): A technical response was provided to Mr. Murawski on 7 February 2011 regarding EPA 's request to use an RAF of 1 for arsenic. This information was also provided in Attachment 4 to Appendix C. See Response to General Comment 1 in Appendix C.
August 3, 2011
Response to U.S. EPA and lEPA Comments on the April 8, 2011 Draft Feasibility Study Report (FS); Old American Zinc Plant Site; Fairmont City, Illinois
Response to 85 c): A technical response was provided to Mr. Murawski on 7 February 2011 regarding the use of an exposure frequency of 235 days/year; the response was provided in Attachment 4 to Appendix C of the FS. The technical basis for this exposure frequency was also provided in Appendix C Section 2, and in Attachment 2 to Appendix C.
86. Appendix C, Section 2.1, page 7, paragraph 1: Delete reference to U.S. EPA Region 2 in the footnote and References section. The U.S. EPA Region 2 risk assessor for the referenced project site (Ringwood Mines) was contacted, who stated that 50% is a site-specific value presented in a draft report that has not been finalized, and should not be cited or quoted.
Response: The noted reference will be removed in the revised FS.
87. Appendix C, Section 2.1.1, page 8, paragraph 3: Delete the bullet per Specific Comment 5 in Attachment 4 (Communications Regarding Draft Human Health Soil Cleanup Goals); the approach is outdated and no longer used by U.S. EPA Region 4.
Response: The noted text will be removed in the revised FS.
88. Appendix C, Section 2.2.1, page 9, Table: Confirm whether 18,200 mg/kg based on 1x10 ELCR or 1.82 mg/kg based on 1x10"^ ELCR is correct since both cannot be correct.
Response: The first paragraph in Section 2.2.1 will be reviewed and revised where required.
90. Appendix C, Sections 2.5 and 2.6, pages 14 and 16, last paragraph in each: Reword the discussion regarding the recommended PCGs for acenaphthylene, phenanthrene, and carbazole. "No PCG is recommended..." and "The PCGs for acenaphthene and pyrene are recommended..." are inconsistent.
Response: The last two sentences in the last paragraph in both Section 2.5 and Section 2.6 will be revised in the revised FS.
Augusta, 2011
Response to U.S. Environmental Protection Agency (USEPA) and Illinois EPA (lEPA) Comments on the April 8, 2011 Draft Feasibility Study Report (FS); Old American Zinc Plant Site; Fairmont City, Illinois
Attachment 1
Revised FS Tables 3-1 and 3-2
Augusta, 2011
Table 3-1
Prel iminary Cleanup Goals for Source Material and Affected Soi ls/Sediments Protect ive of Human Health
Compound
Arsenic
Cadmium
Lead'^'
Zinc
Preliminary Cleanup Goals
Receptor->
Cancer Target Risl<
1E-04
1E-05
1E-06
1E-04
1E-05
1E-06
NC
NO
Residents
Cancer
49
5
0.5
287,916
28,792
2,879
NC
NC
NonCancer
45
NA
NA
45
NA
NA
400
7,026
Recommended
PCG'"
45
45
400
7,026
Commercial/Industrial Workers
Cancer
239
24
2
974,307
97.431
9,743
NC
NC
NonCancer
384
NA
NA
809
NA
NA
1,962
306,600
Recommended
PCG ' "
239
809
g2g(3)
306,600
Construction/Utility Workers
Cancer
16,177
1,618
162
528.033
52,803
5,280
NC
NC
NonCancer
1,122
NA
NA
2,304
NA
NA
826
774,242
Recommended
PCG 1"
1,122
2,304
826
774,242
Recreational Users
Cancer
465
47
5
2,842,865
284,286
28,429
NC
NC
NonCancer
690
NA
NA
1,457
NA
NA
2,725
560,536
Recommended
PCG'"
465
1,457
826(3)
560,536
{1) For each compound, the risk-based value representing the lower of the noncancer PCGs and cancer PCGs based on 1 x10"'' target risk for all relevant receptors is the recommended draft soil PCG for properties that are currently used for residential or commerica! purposes (i.e.. future unrestricted use). See Appendix C for derivation of PCGs.
(2) EPA's default PRG for residential exposures to lead is 400 mg/kg and 800 mg/kg for commercial/industrial exposures (EPA Regional Screening Levels, November 2010).
(3) Construction and Utility Workers are also possible receptors at commercial/industrial properties or alleyways, ditches and Upland Portion of the Old Cahokia wetland. The lead PCG for the Construction/Utility worker is the recommended PCG as it is lower than (he PCG for the Commercial Worker (or Recreational User).
PCG = Preliminary Cleanup Goal NA = Not Available or Not Applicable NC = Not Classified as a carcinogen
Table 3-2 Recommended Preliminary Cleanup Goals (PCGs) for Source Tar Materials In Facility Area Soi l ' " (mg/kg)
Tar IWaterial COI
Benzene
Toluene
Ethylbenzene
Xylenes
1,2,4-Trimetliylbenzene
Phenol
2-IWethylphenol
4-iWethylphenol
2,4-Dimethylphenol
Dibenzofuran
Acenaphthylene
Acenaphthene
Anthracene
Fluoranthene
Fiuorene
Naphthalene
Phenanthrene
Pyrene
Carbazole
Benzo(a)pyrene
Soil Saturation
Limit''' (mg/kg)
1,820
818
480
258
219
171
Commercial/Industrial Worker PCG
based on Cancer Target Risk = 1x10""
548
NC
NC
NC
NC
NC
NTV
NTV
NC
NC
NC
NC
NC
NC
NC
NTV
NC
NC
NC
21
PCG based on Cancer Target Risk = 1x10"'
55
NC
NC
NC
NC
NC
NTV
NTV
NC
NC
NC
NC
NC
NC
NC
NTV
NC
NC
NC
2
PCG based on Cancer
Target Risk = 1x10"'
5
NC
NC
NC
NC
NC
NTV
NTV
NC
NC
NC
NC
NC
NC
NC
NTV
NC
NC
NC
0
PCG based on NonCancer Hazards'''
76
7,610
3,082
396
45
26,382
4,398
440
2,052
NTV
NTV
11,001
165,012
3,143
3,667
90
NTV
2,750
NTV
NTV
Recommended PCGs"! (mg/kg)
76
818
480
258
45
26,382
4,398
440
2,052
NA
NA
11,001
165,012
3,143
3,667
90
NA
2,750
NA
21
Construction Worker ' " PCG
based on Cancer Target Risk = 1x10""
91,896
NC
NC
NC
NC
NC
NTV
NTV
NC
NC
NC
NC
NC
NC
NC
NTV
NC
NTV
NC
1,777
PCG based on Cancer Target Risk = 1x10"'
9,190
NC
NC
NC
NC
NC
NTV
NTV
NC
NC
NC
NC
NC
NC
NC
NTV
NC
NTV
NC
178
PCG based on Cancer Target Risk = 1x10"'
919
NC
NC
NC
NC
NC
NTV
NTV
NC
NC
NC
NC
NC
NC
NC
NTV
NC
NTV
NC
18
PCG based on NonCancer Hazards '̂ '
1,579
101,334
190,460
14,312
4,455
195,663
165,436
6,617
16,544
NTV
NTV
369,894
5,548,412
123,298
147,958
1,101
NTV
92,474
NTV
NTV
Recommended PCGs'" (mg/kg)
1,579
818
480
258
4,455
195,663
165,436
6,617
16,544
NA
NA
369,894
5,548,412
123,298
147,958
1,101
NA
92,474
NA
1,777
Nof«:
(1) All Tar Material will be removed where found to exist In Facility soil.
(2) EPA Regional Screening Levels (November 2010)
(3) See Tables 1 and 3 for target tiazard quotients (HOs) for individual constituents of potential concern.
(4) For each compound, the Hsic-based value representing the lower of the noncancer PCGs and cancer PCGs based on 1x10'' target risk is the recommended draft soil PCG for that receptor group. Where thC' Sol! Saturation Limit is lower than the lower than the noncancer and cancer PCG. the Soil Saturation Limit Is the recommended PCG. See Appendix C for derivation of PCGs.
(5) For all tar material COI, the PCGs for construction worker are based on the assumption of a 30-day total exposure. Alternallva exposure durations for tha construction worker scanario will warrant a ra-svaluation of the soil PCGs.
COI = Compounds of Interest
PAHs = polycyclic aromatic hydrocarixins
PCG = Preliminary Cleanup Goal
NA = Not Available or Not Applicable
NC = Not Classified as a carcinogen
NTV = No Toxicity Value Available
