AR No. IR No. EIELSON AFB ALASKA. Administrative Record Cover Sheet NOTES:

Transcription

1 AR No. IR No. EIELSON AFB ALASKA NOTES: Administrative Record Cover Sheet

2 DEPARTMENT OF THE AIR FORCE AIR FORCE CIVIL ENGINEER CENTER Patrick Roth AFCEC OLA-E th Street, Ste 343 JBER AK April2014 Ms. Kimberly DeRuyter Environmental Program Specialist Alaska Department of Environmental Conservation 610 University Ave Fairbanks, AK Subject: M~mo to the Site File USAF Source Area SS067 Dear Ms. DeRuyter: In accordance with the Garrison Slough Settlement Agreement, the Air Force (AF) conducted an additional Remedial investigation (RI) at SS067 (ref 5.3.5). The draft has been submitted and comments have been received. A draft-final (ref 5.3.6) is being produced. 1. Section of the agreement also calls for a human health and ecological risk assessment. The AF is prepared to complete that effort but would like delay it. 2. A 2008 (unsigned) letter report, dated 28 Aug 2008 from EA Engineering to the AF, shows there is an area with PCBs in the sediment at 234 mg/kg. It is noted here the clean-up level for this site is 1 0 mg/kg. 3. The 2013 draft-final RI shows there are additional areas with PCB contamination in the soil exceeding 1 0 mg/kg. 4. A contract is currently out for proposals and one requirement of this contract is to implement the Record of Decision (ROD)- to complete the removal of the PCB-contaminated soil and sediment as required by the ROD. Another requirement is to investigate all other known sites that may be contributing contamination to the entirety of Garrison Slough (known as SS062). 5. A follow-on contract is planned to address SS062 in its entirety. Given the above five facts, it is apparent conducting a human health and ecological risk assessment at SS067, at this time, would be of very little value. Within a couple of years, we

3 expect the ROD to be fully implemented. Removing the soils over 10 mg/kg would change the results of any risk assessment completed before the removal action. Furthermore, conducting the risk assessment without addressing the entirety of Garrison Slough would most likely give an inaccurate assessment of this area. The AF understands the 2013 Five-Year Review milestone to re-evaluate the RAOs and RAOs achievement after completion of the SS67 Supplemental RI and completion of the sediment removal as required by the ROD is due September Without knowing what else is happening in the slough a useful determination of the RAOs at SS067 would be impossible. We already know there are other source areas, with PCBs being a chemical of concern, potentially impacting Garrison Slough (SS062). (Ref. #4 above.) Therefore, the Air Force requests the human health and ecological risk assessment required at SS067 be postponed until SS062 is addressed in it's entirely (to include SS067). The same applies to evaluating the RAOs at SS067. The Air Force acknowledges that once the slough is addressed in its entirety, another removal action may be required at SS067. If you have any questions, please call me at (907) Sincerely, ~-hb- PATRICK A. ROTH, GS-12, DAF cc: Jackie Kramer (U.S. Environmental Protection Agency, Region 10)

4 DEPARTMENT OF THE AIR FORCE AIR FORCE CIVIL ENGINEER CENTER Patrick Roth AFCEC OLA-E th Street, Ste 343 JBER AK April 2014 Jackie Kramer Superfund RPM USEP A Alaska Office 222 W. 7th Ave., #19 Anchorage, AK Subject: Memo to the Site File USAF Source Area SS067 Dear Ms. Kramer: In accordance with the Garrison Slough Settlement Agreement, the Air Force (AF) conducted an additional Remedial investigation (RI) at SS067 (ref 5.3.5). The draft has been submitted and comments have been received. A draft-final (ref 5.3.6) is being produced. 1. Section of the agreement also calls for a human health and ecological risk assessment. The AF is prepared to complete that effort but would like delay it. 2. A 2008 (unsigned) letter report, dated 28 Aug 2008 from EA Engineering to the AF, shows there is an area with PCBs in the sediment at 234 mg/kg. It is noted here the clean-up level for this site is 10 mg/kg. 3. The 2013 draft-final RI shows there are additional areas with PCB contamination in the soil exceeding 1 0 mg/kg. 4. A contract is currently out for proposals and one requirement of this contract is to implement the Record of Decision (ROD)- to complete the removal of the PCB-contaminated soil and sediment as required by the ROD. Another requirement is to investigate all other known sites that may be contributing contamination to the entirety of Garrison Slough (known as SS062). 5. A follow-on contract is planned to address SS062 in its entirety. Given the above five facts, it is apparent conducting a human health and ecological risk assessment at SS067, at this time, would be of very little value. Within a couple of years, we

5 expect the ROD to be fully implemented. Removing the soils over 10 mg/kg would change the results of any risk assessment completed before the removal action. Furthermore, conducting the risk assessment without addressing the entirety of Garrison Slough would most likely give an inaccurate assessment of this area. The AF understands the 2013 Five-Year Review milestone to re-evaluate the RAOs and RAOs achievement after completion of the SS67 Supplemental RI and completion of the sediment removal as required by the ROD is due September Without knowing what else is happening in the slough a useful determination of the RAOs at SS067 would be impossible. We already know there are other source areas, with PCBs being a chemical of concern, potentially impacting Garrison Slough (SS062). (Ref. #4 above.) Therefore, the Air Force requests the human health and ecological risk assessment required at SS067 be postponed until SS062 is addressed in it's entirely (to include SS067). The same applies to evaluating the RAOs at SS067. The Air Force acknowledges that once the slough is addressed in its entirety, another removal action may be required at SS067. If you have any questions, please call me at (907) cc: Kimberly DeRuyter (ADEC) Sincerely, ~/I~ PATRICK A. ROTH, GS-12, DAF