| Action Date |
Action |
Description |
DEC Staff |
| 8/3/2004 |
Site Characterization Report Approved |
3 August 98 AST Phase II Contamination Assessment Report was located after being misfiled. Report reviewed indicating DRO & GRO soil contamination exceeding ADEC cleanup standards. Nested Bio-venting wells installed in borings B-1 and B-5. |
Donald Seagren |
| 8/6/2004 |
Update or Other Action |
Sent letter to Tyonek Native corporation requesting site status update, any additional assessment/cleanup reports and if the bio-venting system had been operated. Awaiting response from TNC. |
Donald Seagren |
| 11/18/2004 |
Site Added to Database |
Site added to DB by Alyce Hughey. |
Alyce Hughey |
| 11/18/2004 |
Site Ranked Using the AHRM |
Initial ranking. |
Donald Seagren |
| 11/18/2004 |
GIS Position Updated |
Using Figure 1 from an Above Ground Storage Tank Spill Phase II Contamination Assessment, from EMCON Alaska, Inc., dated August 3, 1998, in conjunction with TopoZone Pro and the KPB Parcel Lookup, entered the coordinates for this site. Metadata includes No Topo Basemap, TopoZone Pro Street Maps, Black and White Aerial Photo, on a Medium Size Map, View Scale 1:10,000, Coordinate Datum NAD83. High degree of confidence in accuracy of location. |
Alyce Hughey |
| 11/18/2004 |
Update or Other Action |
File number 2337.38.042 assigned and entered into the Fileroom DB and CS DB. |
Alyce Hughey |
| 5/8/2007 |
Exposure Tracking Model Ranking |
|
Donald Seagren |
| 6/12/2008 |
Update or Other Action |
Site transferred from Don Seagren to Paul Horwath per Linda Nuechterlein. |
Alyce Hughey |
| 9/23/2014 |
Update or Other Action |
File transfered to Anchorage |
Linda Nuechterlein |
| 10/3/2014 |
Exposure Tracking Model Ranking |
A new updated ranking with ETM has been completed for source area 73774 leaking AST tank nozzle. |
Joshua Barsis |
| 10/8/2014 |
Update or Other Action |
Sent a letter on this day, requesting additional information about the spill and site. Response received on October 22, 2014. The response stated that the site is located in a commercial area, with no residential structures in the vicinity. No drinking water wells or surface water intakes are present within 2.5 miles of the site. The site is primarily used for storing a fleet of vehicles. Additional characterization is planned. |
Joshua Barsis |
| 5/28/2015 |
Document, Report, or Work plan Review - other |
Reviewed the Corrective Action Work Plan, dated May 2015. Activities described in the work plan include complete excavation of contaminated soil, land-farming without a liner, and periodic tilling to meet cleanup objectives. |
Joshua Barsis |
| 12/16/2015 |
Document, Report, or Work plan Review - other |
Reviewed the revised Corrective Action Summary Report, dated July 2015, and received on December 16, 2015. Excavation commenced in June 2015 to remove contaminated soil from a historical release of diesel fuel that occurred in April 1997. Roughly 540 cubic yards of impacted soil was removed and land-spread just past the west end of the airplane landing strip. The impacted soil was spread about 6-inches in depth and within an area approximately 325 feet long and 90 feet wide. An 18-inch high soil berm surrounds the land-spread soils. Segregated clean material, and local fill material was used to backfill the excavation. Analytical results from the investigation revealed that concentrations of diesel range organics (DRO) remain within the excavation, and potentially beneath the adjacent structure up to 4,500 mg/kg, which exceeds the ADEC migration-to-groundwater (MTG) cleanup level of 250 mg/kg. Samples collected from the land-spread soil show levels up to 1,180 mg/kg DRO.
|
Joshua Barsis |
| 4/25/2018 |
Workplan Requested |
Letter sent on this day requesting a work plan for follow-on land farm sampling. Work plan requested by June 1, 2018. |
Joshua Barsis |
| 8/15/2018 |
Document, Report, or Work plan Review - other |
Reviewed the Tyonek North Forelands Facility Landfarm Sampling Plan, dated August 13, 2018. Proposed activities include sampling the landfarm to determine if petroleum contamination remains after three years and also to re-evaluated impacts below the onsite building.
|
Joshua Barsis |
| 11/6/2019 |
Document, Report, or Work plan Review - other |
Reviewed the Corrective Action Summary Report, dated October 2018. Completed activities included sampling the land farm, and resampling below the footprint of the adjacent building to determine if attenuation has occurred. Three analytical samples were collected from below the foundation of the building; with levels of DRO ranging from 313 to 4,920 mg/kg.
Eight samples were collected from the land farm soils. Except for one sample (LF-2), DRO ranged from 24.8 to 196 mg/kg. Sample LF-2 exhibited a concentration of DRO at 1020 mg/kg and RRO at 7,110 mg/kg.
Report recommendations call for further tilling and maintenance of the land farmed soils. |
Joshua Barsis |
| 11/18/2019 |
Cleanup Complete Determination Issued |
Based on the information provided to date, it has been determined that the contaminant concentrations remaining on site do not pose an unacceptable risk to human health or the environment and no further remedial action will be required unless new information becomes available that indicates residual contaminants may pose an unacceptable risk. |
Joshua Barsis |
