| Action Date |
Action |
Description |
DEC Staff |
| 10/13/2005 |
Site Added to Database |
Site intake completed with site information provided by the project manager via email. |
Sarah Cunningham |
| 10/13/2005 |
GIS Position Updated |
Coordinates taken from Topozone Pro. The data is is a default value for Clear, Alaksa. More accurate location information will be obtained by the Air Force at a later date. |
Sarah Cunningham |
| 10/13/2005 |
Update or Other Action |
The most heavily contaminated upper foot of soil was excavated and removed. Samples of the remaining soil showed DDT concentrations as has as 7300 mg/kg. A USGS Administrative Report 1993 (AR37) doucments the removal of soil to three feet leaving DDT to 16,000 mg/kg and the subsequent covering of the excavation with a 28 foot by 28 foot PVC liner and then backfilled with aoil to about one foot above the surrounding land surface. Soil and groundwater were sampled in 1994. DDE was found at 420 mg/kg and 310 mg/kg at 4.5 bgs. Thallium was found in groundwater at 8.8 ul/L. |
Debra Caillouet |
| 11/8/2005 |
Update or Other Action |
Staff reviewed site summaries for 23 IRP sites at Clear. The following comment was sent to the Air Force for this site: Site 13 (SS012) is an area where leaky abandoned barrels of DDT had been stored. In 1989, the most heavily contaminated soils were removed to a depth of one foot. In 1990, additional excavation and soil removal occurred to a depth of three feet. Concentrations of DDT remained up to 1700 mg/Kg. One downgradient monitoring well was sampled and no contaminants were found.
The Air Force is proposing a Remedial Investigation to fully characterize the site that will be followed by an FS, PP, and Record of Decision. DEC concurs.
|
Debra Caillouet |
| 7/19/2006 |
Update or Other Action |
Staff reviewed and provided comment on Draft Work Plan for Remedial Investigations at Sites 11, 13, and 21; and Investigation to Support Feasibility Study Development at Site 22 |
Debra Caillouet |
| 8/9/2006 |
Site Characterization Workplan Approved |
The Final Work Plan for Remedial Investigations at Sites 11, 13, and 21; and Investigation to Support Feasibility Study Development at Site 22 was approved
|
Debra Caillouet |
| 3/23/2007 |
Exposure Tracking Model Ranking |
|
Debra Caillouet |
| 4/3/2007 |
Update or Other Action |
staff and the risk assessor provided comment on the draft supplemental remedial investigation and risk assessment |
Debra Caillouet |
| 9/5/2007 |
Update or Other Action |
Comment was sent to the Air Force on the draft final remedial investigation and risk assessment |
Debra Caillouet |
| 8/19/2008 |
Update or Other Action |
The ADEC received an updated Community Involvement Plan for the
Environmental Restoration Program at Clear Air Force Station. |
Debra Caillouet |
| 2/27/2009 |
Risk Assessment Report Approved |
The final Remedial Investigation and Risk Assessment was approved. |
Debra Caillouet |
| 8/11/2009 |
Document, Report, or Work plan Review - other |
Final Site 13 Feasibility Study Report, Clear Air Force Station, June 2009 was approved.
The FS evaluated three main remedial actions, the no action alternative required by CERCLA, cleanup to ecological and/or human health risk based standards with Land Use Controls and complete cleanup to 18 AAC 75.341 Method II levels. All actions except the No Action Alternative would be in compliance with Alaska regualtions. DEC favors the complete cleanup with off-site disposal alternative 4A.
|
Debra Caillouet |
| 4/12/2010 |
Document, Report, or Work plan Review - other |
The Alaska Department of Environmental Conservation (DEC) received the amendment to the Feasibility Study for Site 13 on March 16, 2010. The revision adds two additional remedial alternatives that place the priority on remediating to a human health risk based level rather than the ecological risk. The ecological risk will be above a Hazard Index of 1 if either of these alternatives is chosen by the Air Force, but because of the relatively small size of the site DEC does not object.
Both alternatives rely on a statistical analysis of the risk remaining after the removal actions. The data set used for the proposed alternatives does not follow a discernable distribution and therefore inserts considerable uncertainty in the calculation. If one of these alternatives is implemented the data set used to determine if the remedial action objectives (RAO) have been met will need to demonstrate a statistically valid distribution for DEC to concur that the RAOs have been achieved in accordance with 18 AAC 75.380(c).
|
Debra Caillouet |
| 5/21/2010 |
Document, Report, or Work plan Review - other |
The final 2009 well decommissioning report documents the proper closure of 55 wells throughout the base. It recommends an additional 20 wells be decommissioned. |
Debra Caillouet |
| 12/16/2010 |
CERCLA ROD Approved |
Final Site 13 (SS012) Contaminated Soil Record of Decision dated August 2010 was signed. |
Debra Caillouet |
| 3/22/2011 |
Document, Report, or Work plan Review - other |
Draft Remedial Action Work Plan, Sites 6 and 13, Clear Air Force Station, February 2011 |
Debra Caillouet |
| 6/14/2011 |
CERCLA Remedial Design/Remedial Action Plan Approved |
Final Remedial Action Work Plan, Sites 6 and 13, Clear Air Force Station, May 2011 |
Debra Caillouet |
| 1/20/2012 |
Document, Report, or Work plan Review - other |
Draft Remedial Action Report, Sites 6 and 13, Clear Air Force Station, December 2011 |
Debra Caillouet |
| 9/9/2014 |
Cleanup Complete Determination Issued |
Confirmation samples collected following the excavation indicated that residual 4,4'-DDT
remained in the excavation base, but at concentrations below the applicable ADEC cleanup
criteria of 7.3 mg/kg.
|
Debra Caillouet |
| 9/9/2014 |
Institutional Control Record Removed |
Institutional Controls have been removed. |
Debra Caillouet |
