| Action Date |
Action |
Description |
DEC Staff |
| 11/7/2011 |
Spill Transferred from Prevention Preparedness and Response Program |
Spill transferred by PERP staff Ashley Anderson. Spill no. 10399936302; spill date = 12/29/11; PERP file no. 300.02.018; substance = diesel; quantity = unknown; description: multiple releases at fueling station. |
Mitzi Read |
| 11/14/2011 |
Site Added to Database |
A new site has been added to the database |
Mitzi Read |
| 11/18/2011 |
Document, Report, or Work plan Review - other |
Reviewed Subsurface Soil Investigation Report. The investigation was conducted after a stain was noted following breakup in 2011. The site investigation was conducted in August 2011 and consisted of collecting soil samples from two boreholes at the fueling station. The soil sample from BH 1 at 1.5 feet bgs contained DRO at 1,980 mg/kg and GRO at 1,080 mg/kg and the sample from BH1 at 3 feet bgs contained DRO at 586 mg/kg, GRO at 1,700 mg/kg, and benzene at 11.2 mg/kg. The soil sample from BH2 at 3 feet bgs contained DRO at 7.05 mg/kg and GRO at 43 mg/kg. |
Bill O'Connell |
| 11/18/2011 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed for source area id: 79208 name: NANA Oilfield Services Fuel Station |
Bill O'Connell |
| 2/17/2012 |
Document, Report, or Work plan Review - other |
Reviewed 2012 Gas Station Investigation Work Plan. Nine soil borings are proposed to delineate the nature and extent of hydrocarbon impacts at the tanks and dispenser. Borings will be advanced to an estimated depth of 10 feet bgs. Soil will be screened in place at 6 inch intervals along the soil core. Samples with the highest field screening results will be submitted for lab analysis for DRO, GRO, RO, and BTEX with approximately 10% of the samples also analyzed for PAHs. |
Bill O'Connell |
| 6/29/2012 |
Document, Report, or Work plan Review - other |
Reviewed subsurface soil investigation report for NANA Oilfield Services Block 301 gas station. Twenty boreholes were advanced at the gravel pad and soil samples were collected from the areas with the highest field screening results. One soil sample was collected from each borehole, except two samples were collected from boreholes BH10, BH11, and BH17. GRO was detected up to 8,650 mg/kg, DRO was detected up to 4,260 mg/kg, and benzene was detected up to 248 mg/kg. Analytical results indicate hydrocarbon contamination is present generally to the west of the fueling and fuel storage areas, but is minimal to the north, east, and south. Contaminant concentrations are highest in the 4-6 foot interval. |
Bill O'Connell |
| 9/6/2012 |
Document, Report, or Work plan Review - other |
Reviewed NANA Gas Station Supplemental Investigation Work Plan. The objective of the investigation is to complete the delineation of soil contamination west of the site on the adjacent property. Soil borings will be advanced and field screening and soil sampling will be conducted as necessary to complete the delineation. Activities will be conducted in 2012 or 2013 depending on the availability of sub contractors. |
Bill O'Connell |
| 8/16/2013 |
Document, Report, or Work plan Review - other |
Date of receipt of (draft) Subsurface Soil Investigation report. Initially four direct push borings were advanced with additional ones following in a step-out fashion based on field screening results with a final total of twelve. The soil plume that includes GRO above cleanup levels was better delineated horizontally. ADEC requested a final version of the report with a few minor comments communicated via email. |
Keather McLoone |
| 10/10/2013 |
Potentially Responsible Party/State Interest Letter |
|
Keather McLoone |
| 11/13/2013 |
Document, Report, or Work plan Review - other |
Date of receipt of (final) Subsurface Soil Investigation report. SLR recommended a brief feasibility study to evaluate alternatives targeting the source area, in part due to the concerns about excavating soil that could contain RCRA levels of benzene. |
Keather McLoone |
| 4/11/2014 |
Meeting or Teleconference Held |
Meeting with NANA and their consultant regarding proposed remedial approach of using a staged (potentially yearly over three years time) application of Regenox at site. Also discussed were concerns about offsite migration both off the pad and additional migration onto adjacent pad. Email sent following Monday to confirm discussion. Clarifying email sent 5/13/2014 to further explain ADEC's non-objection to proposed approach(es). |
Keather McLoone |
| 7/2/2014 |
Document, Report, or Work plan Review - other |
Date of receipt of NANA Oilfield Services Inc. Gas Station Site Corrective Action Plan. The planned effort involves soil treatment in phases (by area and year) with the first phase to be conducted in 2014. Surface soil will be excavated to 1 ft bgs, stockpiled, and sampled to evaluate disposal options. Subsurface soil will be treated with Regenox. Based on the effectiveness, similar treatment will be performed in following years. |
Keather McLoone |
| 5/20/2015 |
Update or Other Action |
Date of receipt via email of preliminary report information which includes some data table and a figure. Consultant initially theorized that the lack of efficacy indicated in treatment verification samples was perhaps due to treatment was in mid-August and winter weather conditions began in early September. ADEC does not concur with that theory as nearby site data indicates maximum thaw occurred in later September. There has been no report of treatment activities or plan developed for next steps as of this date. |
Keather McLoone |
| 8/17/2015 |
Document, Report, or Work plan Review - other |
Reviewed the work plan titled 2015 Supplemental Sampling, dated August 13, 2015. Proposed activities mainly consist of waste disposition sampling, surface water sampling, treatment verification sampling, and soil characterization for potential future in-situ treatment. |
Joshua Barsis |
| 2/8/2016 |
Document, Report, or Work plan Review - other |
Reviewed the report titled Gas Station Site Corrective Action and Supplemental Site Investigation, dated January 2016. The report documented the corrective actions and additional characterization performed at the site between August 2014 and August 2015. The project objectives were to remove impacted surface soils to one foot below ground surface (bgs) and treat all remaining subsurface contaminated soil within the Year 1 treatment area with RegonOx® in-situ chemical oxidation. The Year 1 treatment area is located within a larger plume area, and was selected for in-situ chemical oxidation treatment to determine if the contaminant concentrations in the subsurface soil could be reduced to below Method Two and/or Resource Conservation and Recovery Act (RCRA) hazardous waste levels prior to excavation.
An estimated 30 cubic yards of impacted soil were removed in August of 2014 from the top foot of gravel in the Year 1 treatment area. The excavated soil was temporarily stockpiled onsite and eventually transported offsite for thermal treatment. Confirmation soil samples were not collected from the base of the excavation; however, soil samples were collected from six test pits advanced along the Year 1 treatment area boundary. Analytical results indicated that contamination was delineated to the north and east of Year 1 treatment area, but not to the south or west, as expected. Prior to backfilling the 30 cubic yard excavation, 3,430 pounds of RegenOx®, an in-situ chemical oxidation treatment product, was mixed with the subsurface soils in the Year 1 treatment area. Clean fill material was placed over the treatment area and compacted with heavy equipment to restore the usability of the pad.
A total of eight test pits were advanced in February of 2015; four soil borings were advanced in the Year 1 treatment area to verify that the in-situ chemical oxidation treatment successfully reduced contaminant concentration to below Method Two and/or RCRA cleanup levels, and the other four were advanced to the south of the pump house in an effort to delineate petroleum contamination in that area. Soil sampling results indicated that the in-situ chemical oxidation treatment did not noticeably reduce contaminant concentrations in the Year 1 treatment area.
Ten additional test pits were advanced in August of 2015 to further evaluate results of the 2014 in-situ treatment, and also to collect soil chemistry and waste characterization data. Results of this investigation showed that contaminant concentrations within the Year 1 treatment area had evidence of reduced contaminant concentrations; however, one sample collected west of the pump house had levels of toxicity characteristic leaching procedure (TCLP) benzene at 1.51 mg/l, which exceeds the RCRA cleanup level of 0.5 mg/l. Analytical results from several waste characterization samples collected from outside of the Year 1 treatment area exhibited contaminant concentrations up to 1.14 mg/l TCLP benzene, 111 mg/kg benzene, 403 mg/kg toluene, 387 mg/kg xylenes, and 2,350 gasoline range organics; all of which exceed applicable cleanup levels.
In addition to the August 2015 soil sampling effort, a surface water sample was collected from ponded water, located southwest of plume area. Sample results did not exceed total aromatic hydrocarbons (TAH) or total aqueous hydrocarbons (TAQH) for Alaska Water Quality Standards (AWQS).
In a letter dated February 2016, ADEC requested a work plan for additional corrective action by June 2016. |
Joshua Barsis |
| 5/3/2016 |
Document, Report, or Work plan Review - other |
Responded to a letter, dated April 22, 2016 requesting approval to use Method Two soil cleanup levels (instead of Method One) in the man-made gravel pad at this site. DEC responded on May 3, 2016 indicating that an alternative cleanup level is not approved for this site. |
Joshua Barsis |
| 8/2/2016 |
Document, Report, or Work plan Review - other |
Reviewed the Work Plan for Contaminated Soil Removal, dated July 2016 for the NANA Oilfield Services Fuel Station site. Proposed activities mainly consist of excavating all impacted soil above Method One Table A2 and Method Two Table B1 (excluding soil beneath permanent structures). |
Joshua Barsis |
| 6/20/2017 |
Document, Report, or Work plan Review - other |
Reviewed the 2016 Removal Action Report, dated February 2017 for the NANA Oilfield Services Fuel Station site. Activities completed mainly included soil excavation, sampling, excavation dewatering, and backfilling. The excavation was limited horizontally by buried utilities and onsite structures and vertically by native soils (tundra). Results of the removal action indicate that the all contaminated gravel has been removed to the extent practical, and the extent of contamination appears delineated. Contamination remains above applicable cleanup levels beneath the pump house, within five feet of buried utilities, and in the tundra. This site will be evaluated for closure Fall/Winter 2017. |
Joshua Barsis |
| 12/27/2017 |
Exposure Tracking Model Ranking |
A new updated ranking with ETM has been completed for source area 79208 NANA Oilfield Services Fuel Station. |
Joshua Barsis |
| 9/27/2018 |
Update or Other Action |
In response to a letter from the RP dated September 27, 2018, ADEC has recalculated cumulative risk for this site.
ADEC calculated cumulative risk using the following exposure frequencies: 200 days per year (standard), 135 days per year, and 100 days per year. For each of the three exposure frequencies, exposure time [hours per day (hrs/day)] was entered in 30 minute intervals; so 0.5 hrs/day, 1.0 hrs/day, 1.5 hrs/day, 2.0 hrs/day, 2.5 hrs/day, 3.0 hrs/day, 3.5 hrs/day, and 4.0 hrs/day.
At 200 days, a person could spend up to 1 hour per day onsite; at 135 days, a person could spend up to 1.5 hours per day onsite; and at 100 days (the proposed entry), a person could spend up to 3.5 hours per day onsite. Based on information in your letter, a conservative estimate is that a single person would not spend more than 35.5 minutes per day onsite.
See file for associated ADEC letter, dated October 9, 2018.
|
Joshua Barsis |
| 9/6/2022 |
Site Characterization Workplan Approved |
DEC reviewed a work plan for Blocks 303 and 301 to conduct baseline sampling on behalf of new operators Colville. DEC had no objectives and recommended surface water sampling. |
Lisa Krebs-Barsis |
| 2/7/2023 |
Site Characterization Report Approved |
A site investigation was conducted by the new operators. Sixteen borings were advanced, 6 suprapermafrost groundwater samples were collected. No surface water samples were collected but shovel sheen tests were performed. Buried debris was observed south of the fuel storage. Near the fuel storage, GRO and DRO were detected above Table A2 cleanup levels and PAH and VOC were detected above migration to groundwater cleanup levels but below human health cleanup levels. In suprapermafrost groundwater GRO, DRO, RRO, and VOC were detected above groundwater cleanup levels and there were exceedances of water quality standards for TAH and TAqH in the groundwater samples.
Shovel sheen tests performed in undeveloped areas adjacent to the fuel storage yielded low to heavy sheens.
Soil and water were sampled for PFAS. PFOS was detected in soil in one boring below the migration to groundwater cleanup levels. PFAS was detected in all of the groundwater samples analyzed for PFAS but none exceeded groundwater cleanup levels.
|
Lisa Krebs-Barsis |
| 9/6/2023 |
Document, Report, or Work plan Review - other |
Reviewed 2023 Work Plan dated August 23, 2023. Work plan proposed delineating impacted soils on the south side of the tank farm by installing and sampling four soil borings in the vicinity of the 2022 boring SB-13. |
Andrea Carlson |
