Site Report: Exxon West Staines State 18-09-23
| Site Name: | Exxon West Staines State 18-09-23 |
|---|---|
| Address: | Point Thomson, ~50 Miles East of Prudhoe Bay, Prudhoe Bay, AK 99734 |
| File Number: | 300.38.311 |
| Hazard ID: | 26107 |
| Status: | Cleanup Complete |
| Staff: | No Longer Assigned, 9074655229 dec.icunit@alaska.gov |
| Latitude: | 70.137500 |
| Longitude: | -146.390278 |
| Horizontal Datum: | WGS84 |
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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
West Staines State 18-09-23 is a former oil and gas exploration site located in the Point Thompson area of the North Slope. The one onsite well was plugged and abandoned on July 2, 1971. The site consists of a gravel pad and a capped and closed drilling waste reserve pit. In 2010, a total of 111 soil boreholes were advanced to the gravel pad/tundra interface to a depth of 5 feet bgs and at least one soil samples was collected per borehole. The soil samples collected contained GRO up to 250 mg/kg, DRO up to 4,770 mg/kg, and RRO up to 3,860 mg/kg. Two out of 35 samples analyzed for GRO exceeded criteria, two of 137 for RRO, and 31 out of 137 for DRO.
Action Information
| Action Date | Action | Description | DEC Staff |
|---|---|---|---|
| 8/14/2013 | Risk Assessment Report Approved | On this date, ADEC received the Phase II Site Assessment Report – West Staines State #19-9-23 submitted by Weston, dated September 2011. In 2010, a total of 111 soil boreholes were advanced to the gravel pad/tundra interface to a depth of 5 feet bgs and at least one soil samples was collected per borehole. The soil samples collected contained GRO up to 250 mg/kg, DRO up to 4,770 mg/kg, and RRO up to 3,860 mg/kg. Two out of 35 samples analyzed for GRO exceeded criteria, two of 137 for RRO, and 31 out of 137 for DRO. | Grant Lidren |
| 8/16/2013 | Site Added to Database | A new site has been added to the database | Mitzi Read |
| 8/19/2013 | Potentially Responsible Party/State Interest Letter | Keather McLoone | |
| 8/19/2013 | Exposure Tracking Model Ranking | Initial ranking with ETM completed for source area id: 79498 name: Exxon West Staines State 18-09-23 | Grant Lidren |
| 8/25/2014 | Document, Report, or Work plan Review - other | Date of receipt of Corrective Action Plan. Plan also submitted to Solid Waste Program. This work will be performed in conjunction with a corrective action at the nearby West Staines #2 project. The plan objectives include obtaining site closure for the contaminated site by removing most of the pad while also removing the fuel contaminated material. The approach was presented to ADEC CS and SWP in April 2014 Corrective Action Update meeting at ADEC's offices. This will be accomplished by stockpiling and sampling restricted-use gravel (DRO greater than 500 mg/kg but less than 2,000 mg/kg). Contaminated and restricted use gravel will be used to backfill the reserve pit at WSS #2 and the excess will be hauled offsite for treatment or disposal. Clean gravel recovered will be used to backfill two spots in the reserve pit footprint and to backfill any excavations within the gravel pad footprint that are greater than 1 foot below tundra grade. Conditional approval letter sent on 10/6/14 via email clarifying that the condition requesting 100% frequency of GRO/BTEX was for pad confirmation samples only. Hardcopy conditional approval letter also went out on 10/6/14. | Keather McLoone |
| 12/18/2014 | Document, Report, or Work plan Review - other | Date of receipt of Addendum #1 to the Corrective Action Plan and updating database. This addendum was prepared to address both DEC CS and ADNR comments. ADEC requested that all confirmation samples include GRO/BTEX analyses to better characterize contamination that may be remaining at the site when evaluated for additional action or a change in site status. | Keather McLoone |
| 1/5/2015 | Update or Other Action | Date of receipt of attachments that were intended to have been included with submittal received 12/18/14. | Keather McLoone |
| 11/20/2015 | Document, Report, or Work plan Review - other | Date of receipt of Corrective Action Completion Report - West Staines State 18-09-23. This effort included the removal of 8,900 loose cubic yards (lcy) of impacted gravel. Soil concentrations in confirmation samples up to 0.0496 mg/kg benzene, 0.951 mg/kg ethylbenzene, 0.327 mg/kg toluene, 9.82 mg/kg xylenes, 252 mg/kg GRO, 846 mg/kg DRO, and 2460 mg/kg RRO. Debris was encountered during this corrective action effort that was not detected during previous assessments, the majority of which was found at the satellite pad and grid cells C1 and D. In grid cells C1, D, and a portion of M, a blue and white powder was found buried in decomposing bags which was sampled and determine to contain chromium levels requiring disposal of the material as hazardous waste with a final disposition of an appropriate facility in Idaho. In addition to the 100 lcy of chromium-impacted material that was removed, about 650 lcy of miscellaneous non-hazardous debris was removed. Excavation was guided using XRF screening and confirmation samples contained chromium up to 314. This confirmation sample and the other one above migration to groundwater levels (which can be used as indicators of propensity to migrate although otherwise considered not applicable) were also analyzed using TCLP preparation and those results are below the corresponding Table C value. | Keather McLoone |
| 12/8/2015 | Exposure Tracking Model Ranking | A new updated ranking with ETM has been completed for source area 79498 Exxon West Staines State 18-09-23. | Keather McLoone |
| 12/10/2015 | Cleanup Complete Determination Issued | Keather McLoone |
Contaminant Information
| Name | Level Description | Media | Comments |
|---|---|---|---|
| DRO | Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation | Soil | less than Method One based on both composite and discrete samples |
Control Type
| Type | Details |
|---|---|
| No ICs Required |
Requirements
| Description | Details |
|---|---|
| Advance approval required to transport soil or groundwater off-site. | |
| 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) |
No associated sites were found.