ar no. ir no. eielson afb alaskaalaskacollection.library.uaf.edu/eafbsc/cd2/ar895-1.pdf · date:...

AR No.

IR No.

EIELSON AFB

ALASKA

NOTES:

Administrative Record

Cover Sheet

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Typewritten Text

895

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Typewritten Text

5918

Department of Environmental Conservation

Division of Spill Prevention and Response

Contaminated Sites Program

610 University Ave. Fairbanks, Alaska 99709-3643

Main: 907.451.2752 Fax: 907.451.2155

File: 107.38.006

June 13, 2014 Mr. Pat Roth AFCEC/OLA-E 10471 20th Street, Suite 343 JBER, AK 99506-2200 Re: Comments on the Draft 2014 Vapor Intrusion Assessment for Multiple Source Areas, Eielson Air Force Base, Alaska Dear Mr. Roth:

The Alaska Department of Environmental Conservation (DEC) and the U.S. Environmental Protection Agency have reviewed the Draft Vapor Intrusion Assessment Report submitted on behalf of the Air Force by EA Engineering. The report compiles the sample results from sub-slab, near-slab, and indoor air samples collected during the spring and winter of 2013 at multiple buildings potentially impacted by vapors from source areas ST48, ST10/SS14, ST13/DP26, SS61, LF03/FT09, and WP38. The Report concludes that

No further assessment is necessary at: OU 1 ST48 - Building 62035, OU 2 ST10/SS14 Building 6225, OU 2 ST13/DP26 Buildings 4370 and 4386, OU 3 SS61 Building 3134, OU5 LF03/FT09 Building 4371, and OU 6 WP38 Building 6390;

The data was inconclusive at: OU 1 ST48 Building 6203, OU 2 ST13/DP26 Buildings 4377, 4378, and 4387, and OU 6 WP38 Building 6395; and

Management/mitigation may be necessary at OU 3 SS61 Building 3213. We are in general agreement with these conclusions as the wide seasonal variation in sample results and lack of vacuum on several summa canisters when they were received at the analytical laboratory result in a fair amount of uncertainty in the data set. Our specific comments on the report are provided in the attached comment table. We look forward to meeting with you to resolve these concerns and finalize the document.

Addressee 2 Date

O:\(38) CS Files\107 Eielson AFB\107.38.006 EAFB General - Sitewide\Sitewide Monitoring Program\2014\2014 D VI Rpt\2014 D VI Report_CD\Cover ltr D 2014 VI Rpt.docx

Sincerely, Sincerely,

Kim DeRuyter Jackie Kramer Environmental Program Specialist Remedial Project Manager Enclosure: Comment Table cc: Carolyn Tallant, AFCEC Eielson, via email John Halverson, DEC, via email Debbie Yamamoto, EPA, via email

Digitally signed by Kim DeRuyter DN: cn=Kim DeRuyter, o=ADEC, ou=Contaminated Sites Program, [email protected], c=US Date: 2014.06.13 15:19:18 -08'00'

Digitally signed by Jackie Kramer DN: cn=Jackie Kramer, o=USEPA/AOO, ou=ECL, [email protected], c=US Date: 2014.06.13 16:35:54 -08'00'

Addressee 3 Date

O:\(38) CS Files\107 Eielson AFB\107.38.006 EAFB General - Sitewide\Sitewide Monitoring Program\2014\2014 D VI Rpt\2014 D VI Report_CD\Cover ltr D 2014 VI Rpt.docx

of 9 June 13, 2014

Review comments: April 2014 Draft Vapor Intrusion Assessment Report for Multiple Source Areas

Comment No.

Page

Section

Comment / Recommendation

Response

1. General Due to the large data set, and the lack of visual aids (tabular

summaries and figures) it is very difficult to grasp which samples at

each of the buildings detected analytes above screening levels.

Please provide data tables and figures that summarize which samples

of each type (soil gas and indoor air) exceed the screening criteria for

each sampling event.

2. General Figures 5-1 through 5-13

Recommend adding definitions of ‘U’, ‘J’, and ‘UJ’ to figures.

3. General Please provide a discussion of the fixed gas results.

4. General Appendix F notes that ADEC checklists are included for each

laboratory report in Appendix G. The checklists are not included in

Appendix G. Please provide the ADEC Laboratory Data Review

Checklist for Air Samples (September 2012).

5. General As shown in Appendix F, there were numerous examples of analytes

with field duplicate RPD exceedances. The text notes that “The

results for field duplicate precision are indicative of a consistent

sampling program”.

There are several instances of analytes with relatively high RPDs (up

to 195%). Please discuss how the uncertainty associated with this

duplicate data impacts the overall usability of the data.

of 9 June 13, 2014

Comment No.

Page

Section


Response

6. General Appendix F notes that “The LODs for a number of target compounds

exceeded the project screening levels where the compounds were not

detected at or above the LODs. The higher LODs for these

compounds were the result of the limitations associated with the

analytical methods and these limitations were recognized in the

project planning documents as well as dilutions necessary for sample

analysis. The uncertainty associated with these compounds was

recognized in the project planning documents. The LODs that did not

meet the project screening levels are shown in green shading in the

data summary tables of the 2013 VI Assessment Report”.

The report tables include several compounds which are shaded green

(ND values equal or > SLs) and were not expected to have PALs

lower than or equal to the LOQ/LOD/DL, according to Tables 15-1

and 15-2 of the VI QAPP Addendum No. 2. Examples include PAHs

(1-methylnaphthalene, 2-methylnaphthalene, and naphthalene) and

DBCP in indoor air, and naphthalene (PAH) and mercury in sub-slab

gas.

Please discuss these ND exceedances which were not expected and

whether these results impact the usability of the data.

7. General Recommend discussing the compounds that exceeded vapor intrusion

screening criteria due to elevated laboratory reporting limits. Were

these compounds detected previously in soil and groundwater? If

these compounds were detected at elevated levels, was this analysis

included in your conclusions regarding vapor intrusion risk?

8. General Recommend that building survey forms found in ADEC’s 2012 vapor

intrusion guidance be included for each building evaluated.

of 9 June 13, 2014

Comment No.

Page

Section


Response

9. ES-1 ES.1 The second sentence states that “Source Area SS35 is located…..”

Please remove reference to Source Area SS35 location and replace

with a discussion of the source areas presented within this report.

10. ES-3 Indoor Air Concentrations of contaminants measured at elevated levels in indoor

air respective to soil gas suggest a possible indoor background

source. Please explain whether background sources of VOCs were

identified in the building surveys.

11. ES-3 ES.2 Outdoor Air

The text notes that “Benzene and naphthalene are fairly pervasive in

the environment as a result of combustion; common sources being

open burning, tailpipe emissions, and cigarette smoke”.

Was there evidence of open burning or cigarette smoke during the

sampling events which may have influenced the sample results?

12. ES-3 ES.2 Outdoor Air

The text states that “A secondary source of naphthalene is off-gassing

from deodorizers, repellents (mothballs, etc.), and fumigants”.

Were these secondary sources documented within the study areas

during the building surveys?

13. ES-4 VI Assessments Please specify what “moderate concentrations” are in this section.

It’s not clear what this means and how it relates to VI risk.

14. 1-1 1 Suggest noting that a VI evaluation was originally planned for Source

Area ST56 but was later deemed unnecessary, per Worksheet #17 of

the VI QAPP.

15. 1-1 1.2 The text notes that “Source area descriptions and background

information are presented in the VI QAPP Addendum…..”

Page 10-1 of the VI QAPP Addendum states that “The source area

descriptions are presented in the IWMP QAPP (USAF 2012b)

grouped by OU and will not be reiterated in this addendum”.

Please revise report text for consistency.

16. 1-2 1.2

Last ¶

Please note where the updated conceptual site models for each of the

source areas are located.

of 9 June 13, 2014

Comment No.

Page

Section


Response

17. 2-1 2.1 FCF No. 01. The text notes that due to in-floor radiant heating systems, sub-soil

gas points were not installed at Building 3213.

Please clarify text to note that sub-soil gas points were not installed

in the southwest portion of the building. Nine other sub-soil gas

points were installed in Building 3213.

18. 3-1 3.1 “The seven source areas included…..”

Please note that only six source areas were evaluated as part of this

project and that Source ST56 was removed from the project during

the planning stages.

19. 3-1 3.1 “The buildings selected during this process were then physically

inspected and characteristics were documented during the building

inventory activities (Section 3.2)”.

Section 3.2 of the report discusses the sub-slab vapor points. Please

provide details of the building inventory activities within the report.

Also, please include DEC Building Survey and Indoor Air Sampling

Questionnaires (ADEC Vapor Intrusion Guidance, October 2012) for

each building evaluated.

20. 3-2 3.2.1 Sub-Slab Soil Vapor Monitoring Point Location Selection Process -

Please provide more detail on the factors used to select locations for

collecting sub-slab soil gas. What factors mentioned were weighted

with a higher priority?

21. 3-4 3.3 How long were the near-slab points allowed to equilibrate prior to

conducting leak-check testing, purging, and sampling activities?

22. 3-6 3.5.1 Please clarify whether the laboratory specified the 30-minute sample

collection period.

Were there instances when sample collection terminated prior to 30

minutes due to the vacuum gauges reaching -5 in. of Hg? If there

where, how does this impact the data for these samples?

23. 3-8 3.7 Indoor Air

Sampling

Please discuss the factors evaluated to select the indoor air sampling

locations. In addition, please confirm if samples were collected in

the breathing zone (i.e. 3 to 5 feet above the floor)

of 9 June 13, 2014

Comment No.

Page

Section


Response

24. 3-10 3.8 Outdoor Air

Sampling

Please discuss the factors involved in selection of the outdoor air

sampling locations. Were background interferences (e.g. car exhaust)

evaluated in the sample location selection process?

25. 3-11 3.9 Differential

Pressure Monitoring

Please discuss the dates and times these measurements where

conducted. Were the measurements conducted during the indoor air

sampling events?

26. 4-1 4.2 Summary of Data

Usability

Please identify in this section if ADEC laboratory data review

checklists where completed for each laboratory data deliverable.

27. 4-3 4.4. Sub-Slab and Near

Soil Gas Sampling

Results

Due to the high variability of soil gas results, ADEC may recommend

additional soil gas sampling even if the levels measured from one

sampling event do not exceed soil gas screening levels. Recommend

the text be revised to reflect this possibility.

28. 4-3 4.4.1 Detection of

Contaminants in Soil

Gas

A potential source of R-12 and Freon-11 may be the helium tanks

used for the leak checks. This possibility should be evaluated and

discussed. Moreover, these compounds should not be used for

calculating attenuation factors due to the possibility of background

interference.

29. 4-5 4.4.2 The last sentence of the section states that “….at locations where

oxygen concentrations were greater than 10% and less than 10%”.

Does this sentence mean at all oxygen concentrations or should or

should it state “oxygen concentrations were greater than 10% and

carbon dioxide concentrations were less than 10%”?

30. 4-5 4.5 Currently the text lists how many total samples (primary + duplicate)

were collected. Please note how many primary and duplicate

samples were collected.

31. 4-6 4.6 Please clarify why no duplicate outdoor air samples were collected?

of 9 June 13, 2014

Comment No.

Page

Section


Response

32. 4-7 4.7.1 The text notes that 17 contaminants were detected in greater than

80% of the soil gas samples, including R-12, PCE, and Freon-11,

which also exceeded the screening criteria.

Are there background studies which have shown these 17 compounds

to be pervasive in the Eielson area? Are there know background

sources for these 17 compounds in the Eielson area?

33. 4-8 4.7.3 The text notes that 11 contaminants were detected in greater than

80% of the outdoor air samples, including benzene, which also

exceeded the screening criteria.

Are there background studies which have shown these 11 compounds

to be pervasive in the Eielson area? Are there know background

sources for these 11 compounds in the Eielson area?

34. 5-1 5. Vapor Intrusion

Assessments

Recommend that building pressure differential measurements be

discussed for each building to get an idea of the air flow in and out of

the building.

35. 5-1 5. Vapor Intrusion

Assessments

Please discuss for each building what specific background indoor air

sources where documented during the building surveys. If cleaning

products, dry cleaned clothes, or other indoor air background sources

where not documented during the building surveys please discuss this

in the opening paragraph. Moreover, recommend that contaminants

not be eliminated as vapor intrusion contaminants of concern unless

an indoor source is documented during a building survey.

36. 5-3 5.2.1 Please revise first sentence in first paragraph to state that 6203-15 is

located along the southeast side of the building.

Please revise second sentence in second paragraph to state that 6203-

01 is located in the northeast portion of the building.

37. 5-3 5.2.1 The text states that “…it is likely that multiple indoor air VOC

sources are bing stored and routinely used….”

Were indoor VOC sources documented during the building inventory

activities? If sources were observed, please provide examples.

of 9 June 13, 2014

Comment No.

Page

Section


Response

38. Figure 5-1 As presented, it is unclear that the indoor air samples were collected

from separate floors (as shown on 3-7a, 3-7b, and 3-7c).

For clarity, recommend showing on the figure the floor from which

each sample was collected.

39. 5-4 5.2.1 and Figure 5-1 “Consistent detections and concentrations of PCE and TCE were

identified at near-slab soil gas location 6203-15; however, detections

in indoor air were not consistent across the sampling events”.

As shown on Figure 5-1, the closest indoor air sampling points

(6203-07, 6203-08, and 6203-10) to 6203-15 did not contain PCE or

TCE. Although it should be noted that these three samples were

collected from the first and second floors of the structure. An indoor

air sample (6203-01) collected from the basement, approximately 200

ft northwest of 6203-15, contained PCE in excess of the screening

levels. It should be noted that there is a potential that higher levels

are present within the basement level, closer to 6203-15.

40. 5-4 5.2.2 Please include a discussion of the benzene and ethylbenzene

detections in indoor air sample point 62035-02.

41. 5-5 Building 6225 Please note that calculating attenuation factors using the compound

R-12 may not be prudent since this compound may be present in

helium tanks.

42. 5-7 5.4.2 PCE was identified in the indoor air at Building 4377. Considering

the building is utilized for hazardous waste storage, are used solvents

stored within the building?

43. 5-10 5.5.1 The text states that “there are likely indoor air sources that are

contributing to the observed indoor air quality”.

Were indoor sources documented during the building inventory

activities? If sources were observed, please provide examples

44. 5-11 5.6.1 Is there a likely source of the mercury detected at the site?

of 9 June 13, 2014

Comment No.

Page

Section


Response

45. 5-12 5.7.1 The text notes that “1,2-Dichloroethane and 1,2-dichloropropane

concentrations exceeded soil gas screening criteria in a duplicate

sample at one location (6390-01) during the winter 2013 sampling

event only”.

The primary sample did not contain detectable concentrations of 1,2-

Dichloroethane and 1,2-dichloropropane, whereas the duplicate

sample contained 75 ug/m3 1,2-Dichloroethane and 300 ug/m3 1,2-

dichloropropane. Please discuss the uncertainty associated with this

duplicate sample data.

46. 6-2 6.1 4) OU5:

Edit LF03DP09 to LF03FT09.

47. 6-3 6.3.

Management/Mitigation

Please note that the data suggests TCE exposure above ADEC vapor

intrusion target levels based on acute exposure for pregnant women.

Recommend that a meeting be schedule to discuss mitigation

measures to prevent acute exposure to women of child bearing age.

48. Appendix B Field

Sampling Forms for VI

Assessment

Several Summa Canisters had final vacuum gauge readings of 0 in

HG which suggests that summa canister valve may be broken and

therefore, air during shipment may have been drawn into canister.

Recommend results be rejected for each canister that arrived at the

lab without residual vacuum: 3134-05, 4370-11, 3134-05, 3134-19,

4370-21, 4370-30, 4370-34, 4387-02, 4387-03, 4387-04, 62035-02,

6225-03, 6390-04, 6395-06, 6395-10. Please explain if post

sampling vacuum gauge readings were documented prior to removal

from the sampling area.

49. Appendix E Typical Shallow Soil Gas Monitoring Point.

The figure shows that the points were advanced until bedrock. Please

clarify whether bedrock was encountered while installing the soil gas

points.

The text notes that the points were completed with flush mount

vaults. Please show a vault on the figure.

of 9 June 13, 2014

Comment No.

Page

Section


Response

50. F-28 Appendix F The “Source Area WP38 Analytes with Field Duplicate RPDs

Outside Control Limits” table (Page F-27) notes that all analytes

were outside control limits for duplicate sample set 6390-01-SS-C-

R2/6390-01-SS-C-R2-1.

Page F-28 notes that “the field activities adequately collected

representative samples….” Disagree that the above duplicate sample

set provided representative results due to the RPD failures mentioned

above.

51. F-6 Table F-1 Please include a QC requirement for sample management in Table F-

1; multiple Summa canisters had final vacuum measurements with a

0 reading Hg. This is a QC failure which is discussed in our ADEC

lab review checklists. This table should be revised to reflect this QC

failure. TO-15 results with a Summa canister reading of zero should

be rejected.

ar no. ir no. eielson afb alaskaalaskacollection.library.uaf.edu/eafbsc/cd2/ar895-1.pdf · date:...

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