| Action Date |
Action |
Description |
DEC Staff |
| 5/8/2001 |
Site Added to Database |
DRO. |
Bruce Wanstall |
| 5/8/2001 |
Site Ranked Using the AHRM |
Preliminary ranking based on Phase II Site Investigation 12/97. |
Bruce Wanstall |
| 2/27/2003 |
Update or Other Action |
Responsible Party field changed based on new information from PacificCorp Environmental Remediation Company. |
Elizabeth Stergiou |
| 7/12/2004 |
Update or Other Action |
File number issued 2569.38.007. |
Aggie Blandford |
| 5/27/2005 |
Update or Other Action |
Reviewed file and sent e-mail request for project status update to Jon Cowley (PERCO). |
Donald Seagren |
| 6/9/2005 |
Site Number Identifier Changed |
Per Don Seagren request, changed the spill date from 3/7/2001. |
Former Staff |
| 7/18/2005 |
Proposed Plan |
Approved preliminary plan and directed AT&T to develop detailed work plan, including drawings detailing bio-pile construction. 250 mg/kg DRO is the target excavation & remediation goal. ADEC is willing to reevaluate the 250 mg/kg remediation goal and evaluate alternative remediation technologies to achieve remediation to protective of human health and the environment. |
Donald Seagren |
| 7/20/2005 |
Update or Other Action |
Reviewed bioremediation stockpile plans and provided comment to be included in the final plan. |
Donald Seagren |
| 7/25/2005 |
Cleanup Plan Approved |
reviewed & approved cleanup and soil bio-pile remediation plan. |
Donald Seagren |
| 7/27/2005 |
GIS Position Updated |
Using Figure 1 from a Sampling and Analysis Plan, Soils Bioremediation Project, King Salmon Earth Station, from ALTA Geosciences, Inc., dated July 2005, in conjunction with TopoZone Pro, entered the coordinates for this site. Metadata include USGS Topo Map 1:63K, TopoZone Pro Street Maps, on a Medium Size Map, View Scale 1:24,000, Coordinate Datum NAD83. Medium to High degree of confidence in accuracy of location. |
Alyce Hughey |
| 9/12/2006 |
Site Characterization Report Approved |
Reviewed Soil Remediation Construction Completion Report dated August 2006. Remediation was successful at excavating approximately 60 yds3 of contaminated soils that were technically feasible to excavate. Contaminated soil remains in-situ that cannot be excavated due to buildings, utilities, facility water well, the emergency generator AST and paved roads. the impacted asoils appear to be limited in lateral extent. The facility water well is approximately 85' deep and is screened in a deeper aquifer. the 60 yds3 of contaminated soil was placed in an active bio-remediation cell. |
Donald Seagren |
| 4/6/2007 |
Exposure Tracking Model Ranking |
|
Donald Seagren |
| 12/11/2007 |
Update or Other Action |
Received a Bioremediation status report related to recent sampling of the bio-pile. Sampling showed contamination still existing above cleaup levels. the report stated it was due to biogenic interferance. AT&T was asked to re-review the data to make sure this assumption was correct. On further review, it was determined that the soil contamination was not due to biogenic inteferance. the bio pile will be operated for the 2008 field season and re-sampled in the fall of 08. |
Donald Seagren |
| 4/3/2009 |
Update or Other Action |
Received a call from Jim Thorsness/ADOT Leasing concerning AT&T Alascom King Salmon Earth Station. DOT is removing a structure at this lease lot in conjuction with an airport improvement project, and DOT will require At&T to address any contamination encountered. RP is requesting information about area-wide contamination at the KS airport. PM changed to O'Connell and file requested from Soldotna. |
Linda Nuechterlein |
| 4/27/2009 |
Update or Other Action |
Received sample results from September 2008 soil sampling at AT&T King Salmon Earth Station biocell. Four soil samples were collected from the mid-point of the biocell with DRO concentrations ranging from 251 mg/kg to 475 mg/kg. |
Bill O'Connell |
| 5/28/2009 |
Document, Report, or Work plan Review - other |
Reviewed Site Status and Work Plans for 2009/2010. The biocell will be dismantled and the soil spread on site after previous sample results indicated a significant reduction in contaminant concentrations. Three temporary monitoring wells will be drilled at the site and samples collected for field screening TPH in water using a Hach kit, and laboratory samples will also be collected. If the field screening indicates TPH above 2.0 ppm, the well will be completed as a permanent monitoring well. Once the garage on Lot 7 is removed, three hand borings will be advanced and soil samples collected to determine of contamination extends beneath the building. If contamination is found beneath the building, additional soil may be excavated in 2010 and disposed of off-site. |
Bill O'Connell |
| 6/2/2009 |
Site Visit |
Site visit today with AT&T and ADOT to view landspreading area, confirm MW installation locations and discuss future plans for the site. |
Bill O'Connell |
| 1/26/2010 |
Document, Report, or Work plan Review - other |
ADEC received Site Investigation and Biocell Decommissioning Report King Salmon Earth Station Site, submitted by Alta Geosciences, Inc., dated January 2009. Note: this report pertains to the former Garage AST source area only. The biocell was decommissioned and landspread on lot six, between the communications building and the former garage. Three monitoring wells advanced around the former garage encountered groundwater at 16 to 20 ft. bgs; flowing west to southwest. Three groundwater samples and three soil samples collected at the groundwater interface were ND. Five feet east of the former garage at the former garage AST and furnace location, three soil borings were advanced. A total of nine samples: three collected from each boring at the depths of 3 ft., 6ft., and 8ft. bgs; contained detectable levels of DRO, but below ADEC cleanup levels with the exception of one sample collected at 3 ft. bgs which contained 629 mg/kg DRO. |
Grant Lidren |
| 4/7/2010 |
Document, Report, or Work plan Review - other |
A drinking water sample collected from the Communications Building drinking water well on March 11, 2010 did not contain detectable levels of contaminants. |
Grant Lidren |
| 4/29/2010 |
Cleanup Complete Determination Issued |
The Alaska Department of Environmental Conservation (ADEC), Contaminated Sites Program, has completed a review of the environmental records associated with the AT&T Alascom King Salmon Earth Station. Based on the information provided to date, the ADEC has 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 as long as the site is in compliance with established institutional controls. This decision is based on the administrative record for the AT&T Alascom King Salmon Earth Station, which is located in the offices of the ADEC in Anchorage, Alaska. |
Grant Lidren |
| 4/29/2010 |
Institutional Control Record Established |
Institutional Controls established and entered into the database. |
Grant Lidren |
| 6/13/2012 |
Update or Other Action |
Staff changed from Grant Lidren to IC Unit. |
Kristin Thompson |
| 6/13/2012 |
Institutional Control Compliance Review |
IC review conducted and reminder system set-up for 2015 follow-up with responsible party. |
Kristin Thompson |
| 3/9/2015 |
Institutional Control Update |
An IC reminder letter was issued to the responsible party on this date. |
Kristin Thompson |
| 3/18/2015 |
Institutional Control Periodic Reporting |
The responsible party called to confirm that there have been no land use changes at this property. |
Evonne Reese |
| 6/18/2018 |
Institutional Control Compliance Review |
IC compliance review conducted. Closure/IC Details updated. |
Kristin Thompson |
| 8/5/2020 |
Institutional Control Compliance Review |
IC Reminder sent to RP & landowner on this date. Five year review period regarding land use conditions. When powerhouse AST is removed and/or contaminated soil underneath becomes accessible, the soil must be evaluated and contamination addressed. Next review due August 2025. |
Cascade Galasso-Irish |
| 11/4/2021 |
Institutional Control Update |
We've been informed by ADOT that AT&T plans to vacate this property by July 1, 2022. For this reason an extra IC reminder letter was issued since there is an IC requirement that when the building on the property is removed, the remaining contamination must be addressed. Included in this letter was also the ADOT lease requirements details regarding the ICs to let AT&T know there are coinciding requirements from both agencies. |
Evonne Reese |
| 6/8/2022 |
Document, Report, or Work plan Review - other |
A Corrective Action Work Plan to characterize the soil under the power house building and sample the drinking water well was reviewed and approved on this date. The 2010 Cleanup Complete - Institutional Controls decision document required that when the power house building was removed, the contamination under the building would need to be characterized and remediated. AT&T is vacating this property, leased from ADOT&PF, in the fall of this year. |
Evonne Reese |
| 4/28/2023 |
Offsite Soil or Groundwater Disposal Approved |
Staff approved the transportation of petroleum contaminated soil to the STT soil treatment facility. |
Anne Marie Palmieri |
| 6/2/2023 |
Document, Report, or Work plan Review - other |
Reviewed the May 2023 Groundwater and Soil Supplemental Characterization work plan. This work is part of the larger site wide characterization prior to giving up the lease AT&T has with ADOT. This work plan is approved. |
Evonne Reese |
| 6/20/2023 |
Document, Report, or Work plan Review - other |
Received an addendum to the groundwater monitoring plan which includes details about investigation derived waste (IDW) because of the possibility for the groundwater to be contaminated by PFAS which has been documented areawide in King Salmon. |
Evonne Reese |
| 8/9/2023 |
Document, Report, or Work plan Review - other |
Reviewed the Draft Final Corrective Action report on this date. In mid-April and early May 2023, approximately 302 cubic yards of diesel-impacted soil to 13 feet below the ground surface (bgs) was excavated from the property. Field screening and analytical data show the soil at the top of the saturated zone in the source area is impacted with DRO above the most stringent cleanup level. Groundwater is suspected to be impacted. The DRO contaminated vadose zone soil was fully removed except for one location along the SW sidewall at 7’ bgs where soil with DRO at 347 mg/kg remains in place. Groundwater monitoring is planned and DEC approved to begin this season. During this monitoring event, one additional soil boring in the SW will be collected to complete the lateral delineations of the remaining DRO soil contamination. The contaminated soil removed from the property was transported to the STT disposal facility in Nikiski. |
Evonne Reese |
| 9/22/2023 |
Institutional Control Update |
Received confirmation from AT&T that the recent groundwater monitoring does confirm that there is DRO contamination in the groundwater above Table C. The delineation wells were non-detect though which means the contamination is limited in area and has not migrated off of the property. We will work to place the wells in locations that do not interfere with ADOT leasing and redevelopment of the property. A report with the sampling details will follow in the near future. |
Evonne Reese |
| 11/3/2023 |
Document, Report, or Work plan Review - other |
Reviewed the October 2023 Draft Final Groundwater Characterization Report. To delineate the extent of impacted groundwater and soil, five monitoring wells were installed along with one soil boring which was drilled to 8 feet below the ground surface (bgs). DRO concentrations for this residual soil contamination slightly exceed the ADEC Migration to Groundwater cleanup level. All groundwater wells were sampled for VOCs, PAHs, DRO, and GRO and all wells except for MW-05 were below Table C cleanup levels for all COCs. MW-05 had DRO concentrations present in the source area at concentrations above cleanup levels. The limited impacted groundwater does not appear to be migrating off-site. To track the degradation of DRO in the groundwater, future groundwater monitoring events will be planned. |
Evonne Reese |
| 11/3/2023 |
Update or Other Action |
At this point the MW-05 footprint appears to be located outside of future new hangar building which will be constructed. The potential for slightly altering the well location is being discussed between ADOT&PF and AT&T in case the current well location is in the way of building construction. |
Evonne Reese |
| 1/12/2024 |
Institutional Control Update |
All contaminated soil has been excavated and transported offsite for disposal and the powerhouse AST building has been demolished. The database Closure/IC details will note this update. |
Evonne Reese |
| 2/15/2024 |
Institutional Control Update |
A letter was issued on this date to AT&T to acknowledge and confirm that the majority of contaminated soil was excavated and removed from the site. Groundwater monitoring will continue in 2024 and the results from 2023-24 will be used to design a long term monitoring plan. ADOT&PF was copied on this letter. |
Evonne Reese |
| 5/3/2024 |
Institutional Control Update |
I was informed on this date that a representative from Geosyntec will be onsite on May 9 and 10th to sample the groundwater wells. There was not a new work plan for this event since they will be following the same methods and details from the last sampling event. After this upcoming event, a long term monitoring plan will be implemented. |
Evonne Reese |
| 8/15/2024 |
Document, Report, or Work plan Review - other |
In May groundwater samples were collected from the 5 wells on the property. The samples were analyzed for GRO, DRO, VOCs, and PAHs.
In four of the wells no contaminants were present which exceeded the
Table C cleanup levels. Monitoring well 5 (located in the source area) had DRO and several PAHs above Table C levels.
After the 2023-24 sampling events, the extend of the groundwater contamination is considered delineated.
|
Evonne Reese |
| 8/15/2024 |
Long Term Monitoring Established |
Long term groundwater monitoring will include MW-5 only. Analytical data from the
first two monitoring events has shown that groundwater at the other four wells has not exceeded
Table C cleanup levels. It is assumed that if contamination was to migrate off site, it could have done so by now. Groundwater monitoring will happen yearly in the spring and will analyze for DRO and PAHs. Monitoring will continue until five data points have been collected at MW-5 which will allow for trend analysis.
|
Evonne Reese |
