| Action Date |
Action |
Description |
DEC Staff |
| 1/3/1991 |
Site Added to Database |
Free floating product. |
Former Staff |
| 4/1/1991 |
Update or Other Action |
(Old R:Base Action Code = SA2 - Phase II Site Assessment (General)). Received yearlong study report entitled: Subsurface investigation, Tesoro Alaska Facility by Dames and Moore. |
Ben Thomas |
| 12/20/1991 |
Update or Other Action |
(Old R:Base Action Code = MS - Monitoring/Sampling). Verification of free product in a monitor well at subject facility. Sent letter requiring corrective action plan. |
Former Staff |
| 1/10/1992 |
Meeting or Teleconference Held |
Met with ADOT representatives to discuss status of contaminated site. |
Former Staff |
| 1/14/1992 |
Interim Removal Action Approved |
Reviewed and approved and commented on Remedial Action plan. Submitted written response to Tesoro, they agreed. |
Former Staff |
| 1/16/1992 |
Update or Other Action |
(Old R:Base Action Code = FI - Field Inspection (General)). Oversaw contractors performing a soil test at MW-7 where 2 free product was discovered. |
Ben Thomas |
| 1/21/1992 |
Update or Other Action |
(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). Approval of Remedial Action plan. |
Former Staff |
| 1/21/1992 |
Update or Other Action |
(Old R:Base Action Code = F - Site Treatment, Soil/H2O). Groundwater/product recovery/treatment. |
Former Staff |
| 5/22/1992 |
Site Ranked Using the AHRM |
Initial ranking. |
Former Staff |
| 6/5/1992 |
Update or Other Action |
(Old R:Base Action Code = SA2R - Phase II SA Review (CS)). Reviewed workplan. |
Former Staff |
| 6/16/1992 |
Update or Other Action |
(Old R:Base Action Code = CORR - Correspondence (General)). Thomas to Dames and Moore requesting site assessment. Promised in January. |
Ben Thomas |
| 8/18/1992 |
Site Characterization Workplan Approved |
(Old R:Base Action Code = SA2R - Phase II SA Review (CS)). Reviewed and approved plan. Extensive subsurface contamination evidenced including free product. Multiple sources suspected including airport hydrant. Extent of plume to south unknown. |
Ben Thomas |
| 9/1/1992 |
Update or Other Action |
(Old R:Base Action Code = SA1 - Phase I Site Assessment (General)). Received update by Tesoro/Dames and Moore regarding new GW analytical data for existing MWs. Free product still present in 2 wells, BTEX in others. Extent of contamination in dissolved and free phase as yet unknown. |
Ben Thomas |
| 12/2/1992 |
Update or Other Action |
(Old R:Base Action Code = CORR - Correspondence (General)). Letter to ADOT/FAI requesting cooperative effort between Tesoro and FAI conduct joint investigation of Airport land and hydrant system, as well as separate SA2. 60 day response requested. |
Ben Thomas |
| 12/2/1992 |
Update or Other Action |
(Old R:Base Action Code = CORR - Correspondence (General)). Response letter to Tesoro requesting interim corrective action plan, product pumping, and coordinated effort with ADOT/FAI to assess plume to the south of Tesoro on Airport land. 60 day response requested. |
Ben Thomas |
| 2/4/1993 |
Meeting or Teleconference Held |
Spoke with Steve Rog of Tesoro. He said "Tesoro met with Airport and will be undertaking joint investigation in area around the railroad tracks. Tesoro has continued to sample existing MWs and will keep ADEC appraised. Additional borings planned, and Tesoro will submit sampling plan prior to implementation. ADEC will wait for plan. |
Ben Thomas |
| 2/8/1993 |
Update or Other Action |
(Old R:Base Action Code = CORR - Correspondence (General)). Response letter from airport regarding assessment on FAI property. Supports Tesoro's intent to further delineate plume. Asserts that FAI Hydrant system intact and not contributing to GW degradation. FAI will Assist in Delineation if sources other than Tesoro ID'ED. |
Ben Thomas |
| 3/5/1993 |
Interim Removal Action Approved |
(Old R:Base Action Code = SA2R - Phase II SA Review (CS)). Reviewed "Project Status - Proposed Interim Action" report. Tesoro will coordinate with FAI-DOT to delineate plume. Additional MWs proposed for field season 1993. Source(s) still unknown. D&M will continue investigation. ADEC conditionally approves sample plan so long as placement helps better delineation. |
Ben Thomas |
| 1/14/1994 |
Update or Other Action |
(Old R:Base Action Code = RPL2 - Site Information Request Letter). Sent PRP-CS Database Notification Letter to RP requesting update and more environmental information concerning contaminated site. No response has ever been received as of this "complete date". |
Jeff Peterson |
| 10/12/1994 |
Update or Other Action |
(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). Reviewed and approved conceptual CAP by Gilfilian. CAP included baseline assessment of conditions, and using two computer models to evaluate site data (ARMOS 5.1) and develop Corrective Action system (SpillCAD 3.2). Gilfilian will provide information from each 6 tasks as data are available. ADEC asks that a demonstration be given for each model this winter. |
Ben Thomas |
| 1/18/1995 |
Update or Other Action |
SITE SUMMARY: Extensive ground water impact from the bulk tank farm and possible other sources (RR spur, FAI hydrant system, historic spills). Extensive GW assessment complete by D&M. Gilfilian is proposing using two computer models for fate and transport and treatment selection. Get both programs before approval. Treatment system design planned for spring 1995. Should include Free Product Recovery. Plume moves off site under road onto airport apron. |
Cindy Thomas |
| 8/13/2001 |
Update or Other Action |
Site Characterization Report submitted by Gilfilian. Report summarizes past work at site. Kent & Sullivan is new consultant working on site. |
Janice Wiegers |
| 4/24/2002 |
Update or Other Action |
Pilot Test and Feasibility Study Report reviewed. Air sparging system planned at downgradient plume edge to prevent further off-site migration. Additional data gaps to be filled with regards to corrective action feasibility. |
Janice Wiegers |
| 7/10/2002 |
GIS Position Updated |
Changed the Latitude, Longitude, Method Accuracy, Accuracy and Unit fields. |
Heather Goldman |
| 4/12/2004 |
Update or Other Action |
2003 investigation report submitted. Samples were collected in June and October. EDB and EDC were not detected but further sampling for these compounds will be conducted in the railroad header area. The monitoring wells have frost-jacked and need to be resurveyed. Dissolved concentrations appeared to be lower near the air sparging system, which may indicate some treatment is occurring in this area. The air sparging system was operated three times during the summer. Some soil gas migration into adjacent wells was observed during system operation but the consultant indicated the threat of human exposure was minimal.
|
Janice Wiegers |
| 8/23/2005 |
GIS Position Updated |
Using a Site Plan from a Corrective Action Work Plan for 2001 Fairbanks Airport Bulk Plant, from Gilfilian Engineering, dated November 8, 2000, in conjunction with TopoZone Pro, entered the coordinates for this site. Metadata includes No Topo Basemap, TopoZone Pro Street Map, Black and White Aerial Photo, on a Medium Size Map, View Scale 1:10,000, Coordinate Datum NAD83. High degree of confidence in accuracy of location. |
Alyce Hughey |
| 9/16/2005 |
Update or Other Action |
2004 Monitoring report reviews result of water level measurements, groundwater monitoring, and details air sparing system operation. LNAPL was present in 2 wells where it had not been observed in the past. The report speculates that the unusually low water table may have been a factor. Two wells near the air sparge system show significant decreases in hydrocarbon concentration. The data supports the thesis that the air sparge system has been effective in containing downgradient migration of the plume. The lead scavanger EDC was detected in monitoring wells at the southern most corner of the plume. The lateral migration of this contaminant has not be delineated. |
Kim DeRuyter |
| 4/10/2006 |
Update or Other Action |
2005 Groundwater monitoring report received. EDC was observed in several wells located in both the source area and the downgradient edge of the plume. Benzene concentrations are decreasing in all wells except those in the central plume area where free product still exists. All sentinal wells remain non-detect for benzene. The air sparge system appears to have been sucessfull in limiting benzene migration. |
Kim DeRuyter |
| 5/23/2006 |
Meeting or Teleconference Held |
Met with Peter Ribbens and Shawn on site yesterday to discuss modifications to the 2006 monitoring plan. Peter has agreed to include spring and fall sampling at some of the downgradient wells in an attempt to further delineate the EDB and EDC contamination. |
Kim DeRuyter |
| 9/5/2006 |
Update or Other Action |
Received an e-mail from Peter Ribbens stating that Clay Sullivan, the Environmental Consultant for the site had reviewed the preliminary FIA dewatering information, and did not believe that the dewatering would impact the Tesoro groundwater plume. A copy of the e-mail was placed in the site file. |
Kim DeRuyter |
| 12/5/2006 |
Site Characterization Workplan Approved |
EDC in Downgradient Wells letter report received. Further investigation of the extent of EDC migration at the site has confirmed that EDC has migrated beyond the SVE system at the site. EDC has been detected below the Drinking water MCL in one well on the western property boundary. The letter report proposes: the installation of two more monitoring wells to close data gaps,year around operation of part or all of the SVE system, source investigation which will include additional monitoring wells, and a focused feasibility study. A complete report is pending. ADEC approves this interm action. |
Kim DeRuyter |
| 5/31/2007 |
Update or Other Action |
ADEC reviewed the 2006 Monitoring Report for the Tesoro Fairbanks Terminal site. According to the report, samples were collected from the wells in both June and October. The air sparging system was run between those dates and the results indicate a substantial decrease in the benzene levels from June to October. The downgradient sentinel wells did not contain detectable BTEX during either sampling event. EDC was detected in wells MW-31, MW-35, MW-38 and MW-42 which are downgradient of the air-sparge line. The 2007 sampling will include sampling to investigate the sources of EDC at the site. Depending on the 2007 data, Tesoro may change running the AS system from continuous to intermittent operation through October 2007 when the system will again be run continuously through the winter months to minimize line freeze up. |
Deborah Williams |
| 6/1/2007 |
Institutional Control Record Established |
An IC is established for a water well survey to be conducted at this site every third year because of the development in the area. The next water well survey will be due in 2008. |
Deborah Williams |
| 3/13/2008 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed. |
Neal Everson |
| 6/4/2008 |
Site Characterization Workplan Approved |
Reviewed 2007 investigation report and approved 2008 work plan. Semi-annual MW sampling events, delineate EDC plume, sample Caito's dww, and add Air Sparge wells. |
Neal Everson |
| 7/6/2009 |
Document, Report, or Work plan Review - other |
Reviewed 2008 GWM Report. DEC concurs with recommendations and requested information on access to install MWs on off-site properties, requested well survey to the west and requested gw investigation at Tesoro hydrant fuel line site (100.38.171).
|
Neal Everson |
| 9/14/2009 |
Update or Other Action |
Project manager changed to Tamara Cardona-Marek. |
Janice Wiegers |
| 11/19/2009 |
Meeting or Teleconference Held |
DEC staff met with RP and consultant to discuss actions done on site in 2009. EDC plume has been delineated using hydropunch samples. Residential drinking water well was sampled and there was detectable EDC. Tesoro is looking at potentially making the residential well deeper or moving it's location. Soil vapor probes were installed adjacent to the residence. No work plan was submitted for most of the work performed in 2009. The 2007 report contained a partial work plan for the plume delineation activities performed at the site. |
Tamara Cardona-Marek |
| 6/4/2010 |
Document, Report, or Work plan Review - other |
DEC received the 2009 Monitoring and Investigation report. Off-site EDC plume was delineated in 2009, a residential well has been impacted at levels below cleanup. As a result a replacement (deeper) well will be installed for the residence. A vapor intrusion evaluation was also performed at the residence. Soil vapor samples had EDC levels below screening levels or non detect. Some MTBE and EDB (above cleanup levels) were detected. |
Tamara Cardona-Marek |
| 8/9/2010 |
Document, Report, or Work plan Review - other |
DEC received and reviewed Kent and Sullivan's proposed work plan for a Full Scale Pilot Test for a Pump and Treat System that is expected to reduce the extent of the EDC plume that extends downgradient of the Tesoro leased lot towards the river. |
Tamara Cardona-Marek |
| 8/10/2010 |
Meeting or Teleconference Held |
DEC met with Kent & Sullivan and Tesoro to discuss the proposed work plan for a full scale pilot test for a pump and treat that will control the size of the EDC plume that extends outside of the existing air sparging wells. DEC submitted comments to the work plan and recommended that Tesoro considers source treatment after this mitigation effort. |
Tamara Cardona-Marek |
| 8/20/2010 |
Document, Report, or Work plan Review - other |
Work plan for pilot test approved with revisions submitted by Tesoro. |
Tamara Cardona-Marek |
| 2/17/2011 |
Exposure Tracking Model Ranking |
A new updated ranking with ETM has been completed for source area 72377 Multiple Spills/Releases. |
Tamara Cardona-Marek |
| 4/11/2011 |
Document, Report, or Work plan Review - other |
DEC received, reviewed, and commented on the 2010 Groundwater Monitoring Report. |
Tamara Cardona-Marek |
| 8/27/2012 |
Document, Report, or Work plan Review - other |
DEC received and reviewed the 2011 Groundwater Monitoring Report. Pump and treat system is fully functioning now. Locations of some of the wells were altered due to access issues. Infiltration gallery was not installed since it was not considered necessary after observing the injection wells performance. |
Tamara Cardona-Marek |
| 9/7/2012 |
Meeting or Teleconference Held |
DEC discussed with Tesoro and consultant the comments to the groundwater monitoring report and other actions requested by DEC in the past. A revised conceptual site model will be completed listing the long term remedy for the site. |
Tamara Cardona-Marek |
| 11/26/2012 |
Update or Other Action |
DEC received from Tesoro the results for the sampling of the downgradient drinking water well. No contaminants were detected in the well. A shallow monitoring well located on the same property contained EDC above the cleanup level of 5 ppb (at 6.92 ppb). |
Tamara Cardona-Marek |
| 5/21/2013 |
Update or Other Action |
DEC was contacted by Ken Anderson, who is interested in purchasing lots 4 and 5 of the Carpenter subdivision and is concerned with nearby contaminated sites as well as debris left on adjacent properties. DEC shared information about the FIA Tesoro contamination and the nearby residential well that has been impacted by the EDC plume, and put Mr. Anderson in touch with Jeff Baker of Tesoro. Mr. Baker suggested installing a nested well on the property boundary to determine if groundwater is affected at this location and to act as a sentinel well in the event that a drinking water well is installed at the site. Mr. Baker stated that Kent and Sullivan will submit a workplan that includes the proposed installation of this well. |
Robert Burgess |
| 6/6/2013 |
Meeting or Teleconference Held |
DEC met with Tesoro and Kent & Sullivan to discuss the current status of the site and future work. Pump and treat system will be turned on in mid June after an initial round of groundwater monitoring in early June. Monitoring wells will be sampled twice more (in summer and fall) to evaluate system performance and impact to groundwater gradient and flow from recovery and re-injection. Three monitoring wells will be replaced (MW-4, MW-14, MW-36) and several new wells and new soil borings will be installed, including wells on the northern, southern, and eastern boundaries of the benzene and LNAPL plume. Soil borings near or in buildings will be evaluated for soil gas to determine the potential risk of vapor intrusion. EDC plume is expected to attenuate within 1-2 years with continued (seasonal) operation of air sparge and pump-and-treat systems. Well nests will also be installed on nearby properties in the Carpenter subdivision pending approval from property owners and access to currently flooded road. An updated CSM will be provided this year following sub-surface investigation. Source remediation was discussed; Tesoro and K&S suggested sulfate or persulfate injection to oxidize EDC and biostimulate anaerobic petroleum degraders. Biotraps may be included as part of the feasibility evaluation and performance monitoring for biostimulation. |
Robert Burgess |
| 6/10/2013 |
Exposure Tracking Model Ranking |
A new updated ranking with ETM has been completed for source area 72377 Multiple Spills/Releases. |
Robert Burgess |
| 7/22/2013 |
Document, Report, or Work plan Review - other |
DEC received and commented on a workplan to install 2 nested monitoring wells on lots 4 and 5 of the Carpenter subdivision (downgradient of site/crossgradient of EDC plume) to ensure that the groundwater in this area is not affected by the contamination. This work took place in response to an individual considering purchasing the property, who intends to install drinking water wells at some point in the future. |
Robert Burgess |
| 8/12/2013 |
Site Characterization Workplan Approved |
DEC approved of changes to the Carpenter subdivision monitoring well installation workplan. At the request of the property owner, the location of one monitoring well was moved, and an additional nested monitoring well was added in order to help compensate for the change in location. |
Robert Burgess |
| 10/1/2013 |
Site Visit |
DEC project manager visited the site for a tour and to observe the installation of monitoring wells near the rail loading rack. |
Robert Burgess |
| 10/2/2013 |
Site Visit |
DEC project manager visited the site to observe sub-slab vapor sampling with Summa cannisters as part of a vapor intrusion assessment. |
Robert Burgess |
| 6/16/2014 |
Document, Report, or Work plan Review - other |
DEC received and reviewed the 2013 Groundwater Monitoring, Investigation, and Remediation report. EDC concentrations downgradient of the air sparge system have decreased. The installation of additional monitoring wells has provided additional data to help determine the effect of the pump and treat system on groundwater gradient and flow. Re-injection of treated water has caused minor vertical and lateral migration of the benzene plume. Wells installed on the southern extents of the known plume contained contamination and were not able to fully delineate the plume boundaries. Shallow soil gas investigations near the rail loading rack indicate a potential inhalation risk. Methylene chloride was detected for the first time at the site in soil samples near the truck loading rack. Sub-slab sampling resulted in detections of 1,3,5-trimethylbenzene in building 50 samples and chloroform in building 51 samples. Tesoro plans to continue operation of the Air Sparge and Pump-and-Treat systems in 2014. Groundwater monitoring will continue and will include a full set of VOC analyses to include methylene chloride. Additional soil investigation is planned for the rail loading rack. Tesoro also has plans to conduct a pilot study on the feasibility of enhanced anaerobic biodegredation to target petroleum constituents and for persulfate-based chemical oxidation to target EDC. |
Robert Burgess |
| 8/5/2014 |
Update or Other Action |
Approved transport for spent carbon to be disposed of at OIT. |
Janice Wiegers |
| 9/25/2014 |
Document, Report, or Work plan Review - other |
DEC reviewed and approved the 2014 Pilot Test Work Plan for Enhanced Anaerobic Bioremediation. The pilot test will consist of injecting solutions of nitrate and sulfate into different wells in order to determine their potential to stimulate microbial degraders of petroleum. |
Robert Burgess |
| 3/19/2015 |
Meeting or Teleconference Held |
DEC met with Tesoro and Kent & Sullivan to discuss the current status of the site as well as work planned for 2015. 2014 monitoring results indicate that the off-site EDC plume has decreased to concentrations below cleanup levels, although EDC impacts to groundwater remain on the source property behind the air sparge barrier. The benzene and NAPL plumes have still not been fully delineated on the southern and eastern extents. Work planned for the summer of 2015 includes demolition of on-site structures including out-of-commission storage tanks, installation of additional monitoring wells to further delineate the benzene and NAPL plumes, upgrading and expanding the air sparge system, soil borings to delineate EDC impacts in soil, sulfate injection to stimulate anaerobic biodegradation of petroleum products, and excavation of contaminated soils around the former rail loading rack and truck loading rack. Wells that have a long history of no contamination may be removed from the monitoring program. |
Robert Burgess |
| 9/24/2015 |
Interim Removal Action Approved |
DEC reviewed, commented on, and approved after revision the Soil Excavation Plan for the Rail Loading Rack. Contaminated soil in the vicinity of the rail loading rack will be excavated and treated on-site in a lined landfarm. Soil will be fertilized to stimulate biodegradation and regularly tilled to maintain aerobic conditions. Future removal actions may utilize the landfarm as well. |
Robert Burgess |
| 4/20/2016 |
Meeting or Teleconference Held |
DEC received the 2015 Remediation Status Report describing work performed at the site in 2015 as well as plans for the 2016 field season. Activities performed in 2015 include sampling monitoring wells, decommissioning select monitoring wells, operation of the air sparge and pump-and-treat systems, additional pilot testing for sulfate injection, and preparations for excavation work that was delayed until 2016. |
Robert Burgess |
| 5/5/2016 |
Meeting or Teleconference Held |
DEC met with Tesoro and their consultants to discuss ongoing work at the site. Discussion included a summary of activities reported in the 2015 Remediation Status Report and planned activities for 2016, in addition to an analysis of plume stability and using plume analytic techniques and presentation of a 3D model. Work planned for 2016 includes operation of the upgraded air sparging system, excavation of contaminated soil around the rail loading rack, installation of additional monitoring wells to delineate the eastern benzene and LNAPL plume boundaries, decommissioning of select monitoring wells, and continued semi-annual monitoring. The pump and treat system will not be operated in 2016 as it appears that the downgradient EDC plume is attenuating and the upgraded air sparge system should increase the rate of attenuation and further limit migration. Sulfate amendments will also be suspended for the time being due to inconclusive pilot test results and a focus on other remedial efforts; further analysis of sulfate injection is possible in the future. |
Robert Burgess |
| 6/1/2017 |
Document, Report, or Work plan Review - other |
DEC issued a conditional approval for the Work Plan for 2017 Field Activities. The work plan describes groundwater sampling and continued operation of remedial systems. The approval was granted based on the expectation that a revised workplan with additional details would be submitted by June 30. |
Robert Burgess |
| 6/30/2017 |
Document, Report, or Work plan Review - other |
DEC received the revised Work Plan for 2017 Field Activities. |
Robert Burgess |
| 3/6/2018 |
Meeting or Teleconference Held |
DEC met with Tesoro (soon to be Andeavor) to discuss progress made in 2017 and plans for 2018 monitoring and remedial work. The air sparge system was upgraded with an additional 8 wells in the source area to treat EDC and benzene. Monitoring events occurred in spring and fall of 2017 and showed a reduction of BTEX, EDC, and LNAPL thickness in source area wells near MW-19, including MW-19 A and B. Screening results (PetroFlag) for landfarm soils have shown a reduction in concentrations. Monitoring downgradient of the air sparge system shows that some EDC above the updated cleanup levels did pass the air sparge system during its temporary failure in 2016, however with the system repairs and upgrades the sparge barrier continues to function. A phytoremediation evaluation was performed and Tesoro plans to install phytoremediation plots using Poplar trees inoculated with a bacterial endophyte capable of degrading the contaminants of concern. Passive bioventing in the rail area is also part of the plan and will treat benzene and petroleum in the vadose zone of this source area. |
Robert Burgess |
| 5/4/2018 |
Document, Report, or Work plan Review - other |
DEC reviewed the 2018 Letter Work Plan that describes the remedial activities taking place in summer of 2018. Activities described include phytoremediation plots targeted at EDC in soils and groundwater around the truck loading rack, in addition to passive bioventing at the rail loading rack and maintenance of the landfarm and air sparge system. The work plan was brief and did not include necessary details, however communication regarding the plans has been ongoing over the past year. Because of the strong communication and the timing-sensitive nature of the work, DEC issued a conditional approval on the condition that a more detailed plan is submitted by June 15. |
Robert Burgess |
| 5/22/2018 |
Site Visit |
DEC project manager visited the site to view the installation of phytoremediation plots. Other DEC staff also attended for a phytoremediation training opportunity. |
Robert Burgess |
| 8/26/2019 |
Document, Report, or Work plan Review - other |
DEC reviewed and approved the 2019 Groundwater Monitoring Work Plan |
Robert Burgess |
| 8/22/2022 |
Site Visit |
DEC staff conducted a site visit to observe site conditions and phytoremediation plot growth, as well as to discuss upcoming plans with the responsible party and consultants. Tree survival in the center of the plume is poor overall, however there is an apparent difference between trees planted through asphalt and those beyond the edge of asphalt. Phytoremediation consultants believe that the asphalt is restricting water and gases from escaping soils, and suggest that the area of poor growth should be stripped of asphalt and replanted. Trees planted in landfarm soils seem to be surviving with minimal intervention, along with trees in the phyto-2 plot that was focused on vadose zone soil remediation. |
Robert Burgess |
| 4/14/2023 |
Document, Report, or Work plan Review - other |
DEC reviewed the 2022 Annual Report describing field activities and remediation progress. The report also included a work plan for activities planned during the 2023 field season. The work plan was approved. |
Robert Burgess |
| 6/24/2024 |
Document, Report, or Work plan Review - other |
DEC reviewed the 2023 Annual Report documenting plume monitoring and remedial system maintenance activities. Several of the trees from phytoremediation plots were replanted due to tree mortality, and asphalt was removed to prevent accumulation of contaminants in vapor phase that may have contributed to tree mortality, as well as allowing for more precipitation to infiltrate for tree watering. The air sparge system had a temporary failure which was repaired. Monitoring results indicate that EDC may have moved beyond the air sparge barrier during the temporary shutdown, however overall concentrations and plume extents for EDC and benzene continue to decline along with thickness and extent of free product. Remedial goals and strategies remain the same for the next field season. |
Robert Burgess |
| 6/27/2024 |
Meeting or Teleconference Held |
Marathon and their consultants provided a presentation to DEC documenting site activities, current status, and plume dynamics over time including response to remedial activities. As documented in annual reports, the extent of the plume and concentrations in most wells continues to decline and the air sparge barrier continues to be effective in preventing downgradient migration when active. The long-term goal is for phytoremediation to help with hydraulic control, allowing the eventual shutdown of the air sparge system and in situ treatment of contaminants by endophyte inoculated balsam poplar trees. |
Robert Burgess |
| 6/27/2024 |
Site Visit |
DEC staff conducted a site visit with Marathon Petroleum and their consultants. The Fairbanks Airport Environmental Specialist also attended the site visit. |
Robert Burgess |
