| Action Date |
Action |
Description |
DEC Staff |
| 1/13/2014 |
Site Added to Database |
A new site has been added to the database |
Mitzi Read |
| 6/26/2014 |
Cleanup Plan Approved |
Reviewed Work Plan for the Demolition of the AVEC Power Plant in Stebbins Alaska. The work plan includes information collected in 2012 that indicates soil within the secondary containment cells is contaminated with petroleum. The work plan includes the following activities: field screening and soil sampling of soil beneath the lined portions of the tank farm and the piping between the East and West tank farms and field screening and sampling of any other areas that show the presence of contamination. Soil within the secondary containment cells will be segregated into “clean” and “contaminated” stockpiles which will be placed at the Stebbins Landfill. Based on the results of surface soil field screening beneath the tank farm, test pits will be excavated for field screening and sampling. If test pits indicate the presence of contamination, contaminated soil will be excavated and stockpiled until contamination is no longer evident, after which confirmation samples will be collected per the Draft Field Sampling Guidance. Stockpiles that are created during removal of the secondary containment and from the excavation of contaminated soil below the tank farm will be sampled per the Draft Field Sampling Guidance for GRO, DRO, RRO, and BTEX with 10% of the samples also analyzed for PAHs. Clean stockpiled soil will be used at the project site, contaminated soil may disposed of at the Stebbins Landfill if appropriate, otherwise AVEC will propose to treat the soil via landfarming or some other method following completion of this project. |
Bill O'Connell |
| 10/22/2014 |
Document, Report, or Work plan Review - other |
Reviewed Investigation Report for the Old AVEC Power Plant tank farm in Stebbins. The entire power plant, tank farm and appurtenant structures were demolished to make room for an airport expansion. The property is owned by ADOT&PF and was leased to AVEC. The tank farm consisted of two separate tank areas, AVEC East and AVEC West. The Butler Building, where the power generator was located, was also considered a potential source area. The containment liner at AVEC East was intact. Soil above the containment liner was stockpiled into two stockpiles based on PID results, SP-4 and SP-6. Soil below the liner was field screened using a PID and the seven samples with the highest PID readings were submitted for laboratory analyses. Contaminants were not detected in any of the samples. Stockpile SP 4 contained DRO up to 282 mg/kg and was approved for use as backfill at the site. Stockpile SP-6 contained DRO up to 3,790 mg/kg and was transported to the Stebbins Landfill for temporary storage. Contaminated soil was excavated from the footprint of the former Butler Building after it had been demolished and added to stockpile SP-6. Due to space limitations at the Stebbins landfill additional excavation of contaminated soil was not feasible, so the field effort switched from excavation to site characterization. To evaluate the extent of the remaining contamination at the site, seven test pits were excavated in the footprints of the former Butler Building and AVEC West tank farm. At the former Butler Building, DRO was detected up to 1,580 mg/kg in a sample from test pit TP-1, which was intended to characterize the depth of contamination in the area that had already been excavated. The sample from 10 feet bgs in this test pit contained DRO at 30 mg/kg. At AVEC West, soil samples contained DRO up to 13,500 mg/kg in a sample from 2.5 feet bgs in TP-2. The sample from 6.5 feet bgs in TP-2contained DRO at 2,210 mg/kg. Based on the contaminant concentrations remaining and information contained in the report, groundwater is likely to have been impacted by contamination at the site |
Bill O'Connell |
| 1/28/2015 |
Meeting or Teleconference Held |
Meeting with AVEC and TPECI to discuss next steps at Stebbins former power plant/tank farm |
Bill O'Connell |
| 8/5/2015 |
Document, Report, or Work plan Review - other |
Reviewed Work Plan for Additional Excavation and Contamination Delineation at former AVEC Power Plant in Stebbins. Additional contaminated soil from the south end of the former AVEC West tank farm will be excavated and transported to the future landfarming area near the landfill. If contaminated soil remains following excavation, the extent of contamination will be delineated by excavating test pits and collecting soil samples. The presence of groundwater contamination will be evaluated by installing four well points around the facility, calculating the flow direction of groundwater, and attempting to delineate the extent of groundwater contamination. Future work may be necessary to completely delineate and monitor groundwater contamination, if present. |
Bill O'Connell |
| 8/27/2015 |
Document, Report, or Work plan Review - other |
Reviewed work plan for landfarm construction and operation. The landfarm will be constructed at a former gravel borrow area along the Stebbins/St. Michael Road and will consist of a treatment cell approximately 4,140 square feet in size with a compacted soil berm to contain soil. The landfarm will treat the approximately 230 cubic yards of contaminated soil generated during previous and current excavations at the former AVEC Power Plant. Pre-landfarming surface soil samples will be collected from the site and the soil will be spread in a layer approximately 12-18 inches thick and tilled approximately once every two weeks. Post treatment sampling is proposed for September 2016. |
Bill O'Connell |
| 10/8/2015 |
Document, Report, or Work plan Review - other |
Reviewed Summary Report of Additional Excavation and Contamination Delineation at Former AVEC Stebbins Power Plant. The objectives of the 2015 work were to delineate and remove contaminated soil in the vicinity of 2014 test pit AW-TP2, delineate the extent of soil contamination in other areas around the former facility, evaluate for the presence of contamination in groundwater, and plan for future remediation in Stebbins. DRO was detected up to 13,500 mg/kg at 2014 test pit AW-TP2. In 2015, this area was re-excavated however the contamination found in 2014 was not located in 2015. The excavation continued to the groundwater interface approximately 10 feet bgs and confirmation soil samples were collected from the excavation and also from soil that had been excavated. Contaminants were not detected above clean up levels and the excavated soil was returned to the excavation. Three test pits were excavated around the former test pit AW-TP2 and soil samples were collected to evaluate for the presence of contaminants, which were not detected above clean up levels in any of the test pit samples. To evaluate for the presence of groundwater contamination, four well points were installed into excavations around the site including the area at AW-TP2 and groundwater samples were collected. Contaminants were not detected above cleanup levels in groundwater. Soil that was excavated in 2014 and stockpiled at the Stebbins landfill will be landfarmed on property owned by the City in accordance with the approved plan noted in the 8/27/15 database action. |
Bill O'Connell |
| 4/25/2016 |
Update or Other Action |
Approval granted to transport 0.5 cubic yard of contaminated soil from the AVEC St. Michael facility to the AVEC landfarm in Stebbins. |
Bill O'Connell |
| 5/21/2018 |
Update or Other Action |
Sent email to AVEC requesting update on status of landfarm. |
Erin Gleason |
| 9/19/2018 |
Update or Other Action |
Alaska Department of Environmental Conservation (ADEC) reviewed site files of Alaska Village Electric Corp. sites and sent a letter to the AVEC main office requesting they contact ADEC by October 15, 2018 to schedule a meeting to discuss sites at which they are a responsible or potentially responsible party. |
Erin Gleason |
| 11/20/2018 |
Meeting or Teleconference Held |
The ADEC hosted a meeting with the Alaska Village Electric Corporation (AVEC) to discuss the 14 AVEC sites currently on the contaminated sites database. AVEC CEO, and environmental consultant were in attendance as well as ADEC program managers, and site project managers. Individual site status and cleanup needs were discussed for each site, in addition to overall funding sources, level of priority and forward progress at the sites as a whole. |
Kara Kusche |
| 5/20/2019 |
Document, Report, or Work plan Review - other |
Received sampling report from TPECI on 3/13/2019. The work done in this report was under the August 2015 work plan. The landfarm was field screened and sampled fro diesel range organics (DRO), volatile organics compounds (VOCs), and polynuclear aromatic hydrocarbons (PAHs). All landfarm samples were below ADEC cleanup level of 250 mg/kg except for one samples at 259 mg/kg. The groundwater samples indicated that contamination was present and that the water was saline. |
Erin Gleason |
| 6/26/2019 |
Update or Other Action |
Sent information request letter to AVEC, due 7/15/2019. |
Erin Gleason |
| 1/14/2020 |
Update or Other Action |
Received information letter from TPECI on behalf of AVEC. ADEC will review and respond. |
Erin Gleason |
| 2/7/2020 |
Update or Other Action |
ADEC has reviewed the information provided by TPECI in the January 14th, 2020 letter. The letter provides all information requested by ADEC in the June 26th, 2019 Letter. ADEC will use the information provided for a closure evaluation. |
Erin Gleason |
| 8/20/2021 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed for source area id: 79577 name: Stebbins AVEC Power Plant Tank Farm |
Erin Gleason |
| 8/24/2021 |
Cleanup Complete Determination Issued |
|
Erin Gleason |
