Site Report: ADOTPF - Cantwell Maintenance Station
| Site Name: | ADOTPF - Cantwell Maintenance Station |
|---|---|
| Address: | Mile 135 Denali Highway, Cantwell, AK 99729 |
| File Number: | 150.26.033 |
| Hazard ID: | 22890 |
| Status: | Cleanup Complete |
| Staff: | IC Unit, 9074655229 dec.icunit@alaska.gov |
| Latitude: | 63.388998 |
| Longitude: | -148.885004 |
| 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
In June of 1998, five tanks were removed from three locations: one 500-gallon used-oil tank, three 3,000-gallon diesel tanks and one 2,000-gallon gasoline tank. According to the report, an estimated 75 cubic yards of contaminated soil were excavated and stockpiled at the site. Soil samples collected from the excavation area by EMCON at the time of the tank removals contained diesel range organics (DRO) and benzene above the 18 AAC 75.341 soil cleanup levels. In May 2001, a release investigation was conducted at the site that included the installation of three monitoring wells and one soil boring. Samples from all monitoring wells and the drinking water well were non-detect for GRO, DRO, and BTEX. Sample results from the stockpile in September 2002 identified DRO ranging from 484 mgkg to 826 mg/kg. The stockpile was approved for use as fill material on the Denali Hwy. This site attained a NFRAP status rather than a closure, because contamination remained in the tank excavation above migration to groundwater clean up levels near the foundation of the storage building. Contaminants remaining in the soil contained GRO up to 949 mgkg and DRO up to 7,690 mgkg. Benzene exceeded the ADEC cleanup level (0.02 mgkg) in five of the six samples collected, with a maximum benzene concentration of 0.237 mgkg. This contamination is not expected to pose a threat to human health or the environment, and will naturaly attenuate over time.
Action Information
| Action Date | Action | Description | DEC Staff |
|---|---|---|---|
| 6/1/1998 | Leaking Underground Storage Tank Release Confirmed - Petroleum | LUST Site created in CSP for source area ID 75837 Changed date of confirmed release from 2003 to 1998 to correspond with cleanup initiated action. Database QC work - B Janes | Sharon Richmond |
| 6/1/1998 | Leaking Underground Storage Tank Cleanup Initiated - Petroleum | Dataabase QC entry - 75 cubic yards of soil removed when 5 tanks were excavated in June 1998. | Bill Janes |
| 6/1/1998 | Site Added to Database | Former Staff | |
| 7/18/2003 | Update or Other Action | Received email from Mark Lockwood, Shannon & Wilson geologist on June 11, 2003. Email indicates that the storage shed to the south of the former USTs is an unheated, unoccupied building with a concrete slab. It is used for storage of signs and equipment, therefore the inhalation exposure pathway is incomplete. | Sharon Richmond |
| 12/31/2003 | Update or Other Action | RECKEY has automatically been generated. | Former Staff |
| 7/27/2004 | Conditional Closure Approved | A NFRAP letter was sent to ADOT for the ADOT Cantwell Maintenance Station. | Deborah Williams |
| 7/27/2004 | Institutional Control Record Established | Contaminated soil remains along the southwestern portion of the Tank #1, #2, and #3 excavation. Additional excavation was not possible without compromising the foundation of an adjacent storage building. | Deborah Williams |
| 12/14/2011 | Institutional Control Compliance Review | IC review showed that further follow up for this site is needed. | Erik Norberg |
| 12/14/2011 | Institutional Control Record Removed | The conditions at this site meet the 2009 closure policy, therefore ICs can be removed. The default requirement of no offsite transport of soil or groundwater will still apply. In accordance with 18 AAC 75.380(d)(2), ADEC may require additional site assessment, monitoring, remediation, and/or other necessary actions at this facility should new information become available that indicates contamination at this site may pose a threat to human health or the environment. | Erik Norberg |
Contaminant Information
| Name | Level Description | Media | Comments |
|---|---|---|---|
| DRO | Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation | Soil |
Control Type
| Type | Details |
|---|---|
| No ICs Required |
Requirements
| Description | Details |
|---|---|
| Advance approval required to transport soil or groundwater off-site. |
| Hazard ID | Site Name | File Number |
|---|---|---|
| 26345 | ADOT&PF Cantwell Maintenance Station Class V Injection Well | 190.38.006 |