Site Report: ADOT&PF Slana Maintenance Station
| Site Name: | ADOT&PF Slana Maintenance Station |
|---|---|
| Address: | 60 Mile Tok Cut Off, then 1/2 mile down the Nebesna Road, Slana, AK 99586 |
| File Number: | 212.26.001 |
| Hazard ID: | 24632 |
| Status: | Cleanup Complete - Institutional Controls |
| Staff: | IC Unit, 9074655229 dec.icunit@alaska.gov |
| Latitude: | 62.708467 |
| Longitude: | -143.978826 |
| Horizontal Datum: | NAD83 |
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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.
Problems/Comments
Four underground storage tanks (USTs) were removed in 1997: one 2,000-gallon diesel UST, one 8,000-gallon diesel UST, and two 2,000-gallon gasoline USTs. A dispensing island was located above the diesel and gasoline tanks. One of the gasoline tanks had a split seam from the bottom of the tank to within 2 feet of its top and was taken out of service following a release of approximately 1,000 gallons of gasoline in 1979. Approximately 1,200 cubic yards of soil were excavated and stockpiled on site. This soil was later determined to meet ADEC cleanup levels and was approved for use in non-environmentally sensitive areas. All four tanks were removed from a single excavation that extended 18 feet below ground surface (bgs). Soil samples from the limits of excavation detected diesel range organics (DRO) at 5,160 milligrams per kilogram (mg/kg) and gasoline range organics (GRO) at 1,890 mg/kg. The benzene, toluene, ethyl benzene, and total xylenes (BTEX) levels were below ADEC cleanup levels but above detection limits. Highest levels of GRO and BTEX contamination were detected under the former tank where the gasoline release occurred. There is a drinking water well at the site with an estimated depth of 80 feet bgs. It was sampled in 2005 and detected benzene at 0.00265 mg/L and toluene at 0.00331 mg/L which are below ADEC cleanup levels
Action Information
| Action Date | Action | Description | DEC Staff |
|---|---|---|---|
| 10/1/1997 | Underground Storage Tank Site Characterization or Assessment | SA by Shannon & Wilson | Former Staff |
| 12/8/1997 | Leaking Underground Storage Tank Release Confirmed - Petroleum | LUST Site created in CSP for source area ID 77138 Site Assessment received at DEC offices | Former Staff |
| 12/8/1997 | Site Added to Database | Former Staff | |
| 12/9/1997 | Leaking Underground Storage Tank Cleanup Initiated - Petroleum | Excavation removed 50-60 cubic yards of contaminated soil and stockpiled it on site. Extent of impact has not been delineated. | Former Staff |
| 1/28/2004 | Update or Other Action | Transferred DEC staff lead from John Carnahan | Cynthia Pring-Ham |
| 12/2/2004 | Document, Report, or Work plan Review - other | Received and reviewed Feb. 2003 report. Another 1000 cubic yards excavated and stockpiled on site. RP recommends further groundwater and stockpile monitoring. | Kim DeRuyter |
| 9/12/2005 | Document, Report, or Work plan Review - other | Received Soil Stockpile and Water Well Sampling report dated Aug 23, 2005. The highest level of DRO in the samples from the stockpile was 1,660 mg/kg. DRO is the only contaminant remaining above cleanup levels, remaining in the stockpile. ADEC approved landspreading of this stockpile in a non-environmentally sensitive area. The water sample contained 2.65 ug/L benzene and 3.31 ug/L toluene, both values are below Table C cleanup levels. Continued monitoring of this well is recommended. | Kim DeRuyter |
| 7/24/2006 | Institutional Control Record Established | 1. A Notice of Residual Contamination will be noted on the ADEC Contaminated Sites Database identifying the nature and extent of contamination remaining on site. 2. In accordance with 18 AAC 78.274(b), ADEC approval is required prior to the excavation of contaminated soil to ensure worker safety issues are addressed and if soil or groundwater is proposed for transport off site. 3. The drinking water well shall be monitored during the summer of 2006 for GRO, DRO, and BTEX compounds | Shannon Oelkers |
| 7/24/2006 | Conditional Closure Approved | The cleanup actions at this site resulted in the removal of four USTs and 1200 cubic yards of contaminated soil. There is soil remaining above the ADEC cleanup levels (for DRO and GRO) established for the site but further removal was not practicable due to the depth and scope of the excavation. Based on the information provided to date, ADEC has determined that the soil contamination remaining at the ADOT&PF Slana Maintenance Station does not pose an unacceptable risk to human health or the environment provided site specific conditions and/or controls are attached to the property. | Shannon Oelkers |
| 2/16/2012 | Update or Other Action | Staff changed from Bill Petrik to IC Unit. | Kristin Thompson |
| 10/21/2015 | Institutional Control Compliance Review | IC compliance review conducted. A requirement of closure was that groundwater monitoring be completed in 2006. If it was we did not receive record of it. Contact the RP to request this information. | Evonne Reese |
| 10/26/2015 | Institutional Control Update | Contacted ADOT and they are going to schedule a drinking water sample event for this location. Once we receive the sampling results we'll determine if ICs are needed into the future. | Evonne Reese |
| 11/23/2016 | Institutional Control Update | This site has an injection well that is going to be decommissioned in 2018. The drinking water sampling will be performed at the same time. The reminder system has been updated to check back in late 2018. | Evonne Reese |
| 12/29/2016 | Institutional Control Compliance Review | IC compliance review conducted. Closure/IC Details updated. | Kristin Thompson |
| 2/19/2019 | Institutional Control Update | The drinking water well was sampled during the December 2018 injection well decommissioning. The water was sampled for volatile organic compounds (VOCs) which did not contains analytes above the Table C cleanup levels. The 2006 groundwater monitoring requirement will be removed for this site. All other institutional controls requirements will remain in place. | Evonne Reese |
| 8/8/2023 | Institutional Control Compliance Review | IC compliance review conducted with the help of a site visit/inspection by the Copper River Native Association representative. The property is still operated as a ADOT maintenance station. Vegetation on the property is healthy looking and the ground looks undisturbed other than vehicle tracks. | Evonne Reese |
Contaminant Information
| Name | Level Description | Media | Comments |
|---|---|---|---|
| GRO | Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation | Soil |
Control Type
| Type | Details |
|---|---|
| CS Database Notation And Letter To Landowner/RP | In accordance with 18 AAC 78.274(b), ADEC approval is required prior to the excavation of contaminated soil to ensure worker safety issues are addressed and if soil or groundwater is proposed for transport off site. |
Requirements
| Description | Details |
|---|---|
| Advance approval required to transport soil or groundwater off-site. | Standard condition. |
| Movement or use of contaminated material (including on site) in a manner that results in a violation of the water quality standards is prohibited (18 AAC 70) | Standard condition. |
| Hazard ID | Site Name | File Number |
|---|---|---|
| 26927 | ADOT&PF Slana Maintenance Station Class V Injection Well | 212.38.003 |