| Action Date |
Action |
Description |
DEC Staff |
| 3/1/1989 |
Update or Other Action |
(Old R:Base Action Code = F - Site Treatment, Soil/H2O). Free product recovery and vapor extraction. Cleanup in progress since 3/89. |
Former Staff |
| 12/12/1990 |
Site Ranked Using the AHRM |
Initial ranking. |
Former Staff |
| 1/7/1992 |
Update or Other Action |
(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). Modified Remedial Action Plan submitted by America North. Plan provides additional detail regarding on-site containment. |
Former Staff |
| 1/25/1994 |
Site Added to Database |
|
Former Staff |
| 3/6/2001 |
Update or Other Action |
File number updated from 630.02.008 to 630.38.007. |
Mitzi Read |
| 4/21/2006 |
GIS Position Updated |
Using Figures 1 and 5 from the Unalakleet Native Corporation Garage and Fuel Tank Area Site Assessment and Remediation, from R&M Consultants, dated March 1990, in conjunction with TopoZone Pro, entered the coordinates for this site. Metadata includes USGS Topo Map 1:63K Series, Topozone Pro Street Maps, on a Medium Size Map, View Scale 1:48,000, Coordinate Datum NAD83. Moderate degree of confidence in accuracy of loctaion. |
Alyce Hughey |
| 11/20/2006 |
Update or Other Action |
Contaminated sites staff issued a letter to the Unalakleet Native Association requesting an update regarding corrective actions that have taken place at the spill site. The most recent information available in the case file is a 1995 Corrective Action Report prepared by Geosphere, Inc. This report depicts that the two soil vapor extraction (SVE) systems were operated in 1995 from June 6th thru October 10th, and up to 4,100 gallons of gasoline was removed as vapor. In addition, monitoring data indicated that up to 800 gallons of gasoline were biodegraded due to the increased subsurface oxygen concentrations. The report recommends that both SVE systems be operated in 1996. A phone conversation with Larry Acomb depicted that his involvement ended at approximately the same time. |
Don Fritz |
| 6/5/2008 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed. |
Don Fritz |
| 5/29/2009 |
Update or Other Action |
File transferred from Soldotna to Anchorage 6-1-09. Project |
Alyce Hughey |
| 3/2/2010 |
Update or Other Action |
Phone call with Mark Johnson, CEO of UNC. DEC will forward file info to UNC and they plan on contracting with a consultant to conduct additional investigation at the site. |
Bill O'Connell |
| 5/19/2010 |
Update or Other Action |
Phone conversation with consultants at BSI regarding potential work at the site this summer |
Bill O'Connell |
| 7/1/2010 |
Document, Report, or Work plan Review - other |
Reviewed Work Plan for Cleanup Assessment and Groundwater Monitoring at UNC Tank Farm. The objectives of the investigation are to assess the current status of monitoring wells and remediation equipment on site since the mid 1990's and collect groundwater samples from up to 9 wells to evaluate current contaminant concentrations. Water and product levels will be measured in all available wells. |
Bill O'Connell |
| 1/7/2011 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed for source area id: 71785 name: Unalakleet Native Corporation Gas Spill |
Bill O'Connell |
| 3/9/2011 |
Document, Report, or Work plan Review - other |
Reviewed Cleanup Assessment and Groundwater Monitoring Report for Unalakleet Native Corporation Tank Farm. Only one of the original groundwater monitoring wells, well TH-R6, was intact and available for sampling. GRO was detected at 40.1 mg/l and benzene was detected up to 1.9 mg/l. Toluene, ethylbenzene and xylenes were also detected above cleanup levels. The SVE equipment was no longer functional |
Bill O'Connell |
| 8/11/2011 |
Document, Report, or Work plan Review - other |
Reviewed Work Plan for Site Investigation at UNC Tank Farm. Well points will be driven and sampled in an effort to delineate the extent of groundwater impacts, and surface water will be sampled to evaluate potential migration to nearby surface water bodies. |
Bill O'Connell |
| 4/4/2012 |
Document, Report, or Work plan Review - other |
Reviewed 2011 Site Investigation Report from UNC Gas Spill. Five drive point wells were installed and sampled, and shovel sheen testing was conducted at 4 surface water locations adjacent to the site. The drive points were installed in an effort to delineate the extent of groundwater contamination remaining at the site. Only one groundwater sample contained contaminants above Table C cleanup levels. East Well 2 contained GRO at 13.5 mg/l and benzene at 0.183 mg/l. Shovel sheen testing did not indicate the presence of hydrocarbon sheen at any of the locations where it was conducted. Data gaps exist east of East Well 2 and west of TH-R6, which was sampled in 2010 and found to be contaminated. A request was submitted to UNC to further delineate the extent of contamination. Five of the former monitoring wells were decommissioned, other former monitoring could not be found or had been destroyed or filled in |
Bill O'Connell |
| 6/19/2012 |
Document, Report, or Work plan Review - other |
Reviewed work plan addendum for 2012. Two new monitoring wells will be installed in an effort to delineate the extent of groundwater contamination and samples will be collected from the new wells and from the 5 existing wells. |
Bill O'Connell |
| 9/7/2012 |
Document, Report, or Work plan Review - other |
Reviewed Final Site Investigation Report-Unalakleet Native Corporation Tank Farm. Two new microwells designated P1 and P2 were installed to the east and west, respectively, of the known groundwater plume in an effort to delineate the extent of groundwater contamination remaining at the site. Following well installation, an effort was made to sample the two new wells and the 5 existing wells, however wells EW2, North Well, and I Well were dry and no samples were collected. Of the wells that were sampled, none contained contaminants above Table C cleanup levels, indicating the plume has been successfully delineated. The dry wells were within the plume, so data was not collected to evaluate trends in contaminant concentrations. |
Bill O'Connell |
| 6/28/2013 |
Document, Report, or Work plan Review - other |
Reviewed 2013 work plan for groundwater sampling. Five wells will be sampled and analyzed for GRO and BTEX to evaluate trends in groundwater contaminant concentrations. |
Bill O'Connell |
| 6/12/2014 |
Document, Report, or Work plan Review - other |
Reviewed 2013 monitoring report for Unalakleet Native Corporation Tank Farm. Groundwater sampling was attempted at the 5 existing monitoring wells, but no samples were collected. East Well 5 was not located and is presumed to have been destroyed, well P2 was dry, and well East Well 2, I well, and North Well did not recharge after purging. |
Bill O'Connell |
| 6/12/2014 |
Exposure Tracking Model Ranking |
A new updated ranking with ETM has been completed for source area 71785 Unalakleet Native Corporation Gas Spill. |
Bill O'Connell |
| 8/27/2015 |
Update or Other Action |
Communication with UNC and Bethel Services regarding current project status and future investigation. |
Bill O'Connell |
| 9/16/2016 |
Update or Other Action |
Letter sent to UNC regarding data gaps that remain at the site. |
Bill O'Connell |
| 7/30/2018 |
Document, Report, or Work plan Review - other |
Reviewed Work Plan for Groundwater and Limited Vapor Intrusion Assessment. Monitoring wells I-Well and North-Well will be replaced with excavation installed. pre-packed well points, then developed and sampled for GRO, VOCs, PAHs, and EDB. The ADEC Building Inventory and Indoor Air Sampling Questionnaire will be completed for the Older UNC Building and Ivanoff Residence. |
Bill O'Connell |
| 7/1/2019 |
Document, Report, or Work plan Review - other |
Reviewed UNC Gas Spill Groundwater and VI Assessment report. Two replacement groundwater monitoring wells were installed in September 2018. MW-1 replaces the former “I-well” and MW-2 replaces the former “North Well”. The wells were sampled in October 2018 and did not contain contaminants above groundwater cleanup levels. The vapor intrusion evaluation consisted of a building walk through at the Older UNC Building and a private residence and completion of the building survey for each property. The Johnson and Ettinger model was then used to estimate VI risk. Based on the available data and site observations VI is not considered a current risk at the site. |
Bill O'Connell |
| 7/8/2019 |
Update or Other Action |
Site location was updated on this date. Coordinates for this site are used to determine the presence and position of the site on BLM’s ANCSA Conveyed Land web map. |
Rebekah Reams |
