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Site Report: ARRC - Tunnel Section

Site Name: ARRC - Tunnel Section
Address: Railroad Mile Marker 51; 12 mi. S. of Portage, Girdwood, AK 99587
File Number: 2113.26.002
Hazard ID: 23254
Status: Cleanup Complete
Staff: IC Unit, 9074655229
Latitude: 60.666117
Longitude: -149.042118
Horizontal Datum:WGS84

We make every effort to ensure the data presented here is accurate based on the best available information currently on file with DEC. It is therefore subject to change as new information becomes available. We recommend contacting the assigned project staff prior to making decisions based on this information.


Three USTs were decommissioned in 1991- a 10,000 gal diesel UST, a 500 gal. diesel UST, and a 1,000 gallon gas UST. During excavation activities, petroleum contamination was encountered in the soil. 170 cubic yards of contaminated soil was excavated and stockpiled and later removed from site. Additional characterization was performed in 1992. Six test pits indicates soil contamination remains on site above ADEC cleanup levels. The onsite water well was sampled. Contaminates were not detected. A Leachate Modeling effort conducted in 1998 indicated petroleum hydrocarbons would not reach groundwater at 356 feet bgs within 20 years. No further action granted on March 21, 2008 subject to institutional controls.

Action Information

Action Date Action Description DEC Staff
10/10/1991 Leaking Underground Storage Tank Release Confirmed - Petroleum LUST Site created in CSP for source area ID 77920 ADD; Diesel fuel contaminant. * Not Assigned
10/10/1991 Site Added to Database * Not Assigned
10/11/1991 Leaking Underground Storage Tank Cleanup Initiated - Petroleum LCAU; :LCAU Date changed DB conversion * Not Assigned
10/11/1991 Underground Storage Tank Site Characterization or Assessment SA1R; :Action Date changed DB conversion 1/11/11 * Not Assigned
10/11/1991 Update or Other Action NOR; :Action Date changed DB conversion 1/11/11 * Not Assigned
10/11/1991 Update or Other Action CAPR; :Action Date changed DB conversion 1/11/11 * Not Assigned
11/6/1991 Long Term Monitoring Established MS; AK Railroad sent in samples for reveiw. One sample had 21,800 ppm EPH detected per method 3510/3550/8100 MOD. Site was backfilled, a PVC gallery installed for future bioremediation work if necessary. * Not Assigned
2/6/1995 Release Investigation RELR; Departmental staff reviewed and provided comments to the railroad on their site characterization report. The department also requested a corrective action plan. * Not Assigned
2/15/1995 Report or Workplan Review - Other Review Draft Leachate Modeling Report Tunnel Sites submitted by ENSR and recieved by the ADEC on this date. The ARRC was notified in 1997 that the model was not acceptable by the ADEC Grant Lidren
1/15/1998 Report or Workplan Review - Other Tunnel Section Report of Findings submitted by CH2MHILL. Contamination above ADEC cleanup levels remain on site with DRO up to 15,300 mg/kg(TS12), benzene up to 0.39 mg/kg(TS10), and xylenes up to 97.4(T1) mg/kg. Groundwater was not encoutered during 5 trench excavations in 1992. 139 cubic yards of contaminated soil was removed from trench excavation 5 (T5). The other 4 trench excavations were backfilled with potentially contaminated soil Drinking water well behind section house samples indicate no contamination. Grant Lidren
7/27/2004 Update or Other Action File number assigned and entered into the Fileroom DB and LUST DB. Alyce Hughey
12/21/2004 Update or Other Action File transferred to Linda Nuechterlein for Projet Manager change in the Anchorage Office. Monica English was last staff assigned. Alyce Hughey
8/3/2005 Update or Other Action File number reassigned 2113.26.002, formerly 2100.26.235. Aggie Blandford
10/5/2005 Update or Other Action Project manager changed from Eric Henry to Sarah Cunningham Sarah Cunningham
2/26/2008 Update or Other Action Verified position with Arc GIS SPAR Statewide Locater Grant Lidren
2/26/2008 Exposure Tracking Model Ranking Intitial Ranking Complete for Source Area: 77920 (Autogenerated Action)
3/18/2008 Exposure Tracking Model Ranking Updated Ranking Complete for Source Area: 77920 (Autogenerated Action)
3/21/2008 Institutional Control Record Established There is contamination remaining above established cleanup levels at the Alaska Railroad Corporation - Tunnel Section, but ADEC has determined there is no unacceptable risk to human health or the environment, and this site will be conditionally closed. The ADEC has determined that no further remedial action will be required at this site subject with the following conditions: 1. A Notice of Environmental Contamination will be recorded on the ADEC database to document that there is residual contamination remaining on site above the most stringent ADEC cleanup levels. 2. Any proposal to transport soil off site requires ADEC approval in accordance with 18 AAC 78.274(b). Grant Lidren
3/21/2008 Conditional Closure Approved The Alaska Department of Environmental Conservation, Contaminated Sites Program (ADEC) has completed review of the environmental records associated with Alaska Railroad Corporation - Tunnel Section. This site had been contaminated by the release of a hazardous substance; however, based on the information provided to date, ADEC has determined that no further remedial action is required, and that Alaska Railroad Corporation - Tunnel Section can be closed subject to the conditions outlined in this document. The hazardous substance contamination has been adequately addressed and does not pose an unacceptable risk to human health or the environment. Grant Lidren
6/13/2012 Update or Other Action Staff changed from Grant Lidren to IC Unit. Kristin Thompson
7/9/2012 Institutional Control Compliance Review IC review conducted. Evonne Reese
7/9/2012 Institutional Control Record Removed This site meets the 2009 closure policy therefore ICs can be removed. The default requirement of no offsite transport of soil or groundwater from this site is still applicable. Evonne Reese
7/9/2012 Long Term Monitoring Complete Administrative action on 5/1/2013. Kristin Thompson

Contaminant Information

Name Level Description Media Comments
BTEX Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation Soil
DRO Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation Soil

Control Type

Type Details
No ICs Required


Description Details
Advance approval required to transport soil or groundwater off-site.

Missing Location Data

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