| Action Date |
Action |
Description |
DEC Staff |
| 12/12/2016 |
Site Added to Database |
A new site has been added to the database |
Mitzi Read |
| 12/12/2016 |
Leaking Underground Storage Tank Release Confirmed - Petroleum |
LUST site created in CSP database for source area UST Fill Port Upgrades, 79996 |
Mitzi Read |
| 1/12/2017 |
Potentially Responsible Party/State Interest Letter |
DEC sent a letter by electronic mail notifying Delta Western of their cleanup responsibility for the Site. |
Bruce Wanstall |
| 1/13/2017 |
Document, Report, or Work plan Review - other |
DEC approved a site assessment report by IMS Technical Services for Delta Western. A letter was sent electronically to Delta Western requesting a corrective action plan be submitted for approval. |
Bruce Wanstall |
| 1/19/2017 |
Meeting or Teleconference Held |
DEC UST and CS staff met with Delta Western Inc. and their consultant ISM to discuss the site status. Discussion included the recent successful three year UST testing for leak detection and corrosion that prompted the replacement of the spill buckets on four USTs at the site. Due to uncertainty surrounding Delta Western finding the as-built plan for UST to dispenser piping, the location of placing several groundwater monitoring wells at the site remains uncertain. Delta Western will continue to look for these documents and will submit a work plan. |
Bruce Wanstall |
| 4/14/2017 |
Document, Report, or Work plan Review - other |
DEC has reviewed and approved with comment: Juneau Valley Tesoro Station: Monitor Well Installation Work Plan/Sampling & Analysis Plan (Plan), dated April, 2017. ISM Technical Services (ISM) completed the Plan for Delta Western Inc. to conduct subsurface investigation of soil and groundwater conditions at the referenced Site. DEC agreed there was not a major release but concluded that a release investigation (18 AAC 78.235) was necessary and requested actions be taken during the 2017 season. For quality assurance evaluation purposes, a field duplicate will be collected from each media (soil and water) and will be analyzed for each parameter tested and the relative per cent difference calculated on the laboratory data review checklist. The subsequent report will contain a conceptual site model evaluation of the exposure pathway risks at the site and narrative summary of data quality and usability. The Plan is approved in accordance with 18 AAC 78.260. |
Bruce Wanstall |
| 6/30/2017 |
Leaking Underground Storage Tank Cleanup Initiated - Petroleum |
Administrative action addition for grant reporting purposes.
|
Evonne Reese |
| 8/29/2017 |
Update or Other Action |
Consultant drilled wells and found some contamination and free product. Investigation is ongoing. |
Danielle Duncan |
| 10/30/2017 |
Document, Report, or Work plan Review - other |
Approved a work plan for advancing up to 10 soil borings using a GeoProbe drill rig and installing another 3 groundwater monitoring wells. Once the soil borings have been made, field screening samples will be collected from the groundwater interface and analyzed using a photoionization detector (PID). The results will be used to determine the placement of new wells. The wells will have a ¾ inch PVC casing with a 2 ¼ inch screened outer casing and prepacked filter sand between the inner and outer casings. The wells will be developed and sampled as the prior work plan using a low-flow technique and a bladder pump with disposable tubing and will be analyzed for diesel range organics (DRO), residual range organics (RRO), gasoline range organics (GRO), lead, benzene, toluene, ethylbenzene, and xylenes (BTEX), and polycyclic aromatic hydrocarbons (PAHs).
|
Danielle Duncan |
| 5/1/2018 |
Site Characterization Report Approved |
Soil and groundwater samples were collected and contaminants above ADEC cleanup levels were documented. More investigation is needed. |
Danielle Duncan |
| 7/3/2018 |
Site Characterization Workplan Approved |
Approved the Groundwater Monitoring Work Plan prepared by Farallon Consulting LLC this date. The current work is to measure the depth to groundwater and to sample all 9 wells and analyze them for gasoline range organics (GRO), diesel range organics (DRO), residual range organics (RRO), benzene, toluene, ethylbenzene, and xylenes (BTEX), and polycyclic aromatic hydrocarbons (PAHs). Please note that according to Appendix F of the 2017 ADEC Field Sampling Guidance, the full suite of volatile organic compounds must be analyzed – this can occur during the current or a future effort. |
Danielle Duncan |
| 8/1/2018 |
Site Visit |
Site visit with ISM to discuss soil, groundwater, and potential vapor intrusion. |
Danielle Duncan |
| 10/5/2018 |
Site Characterization Workplan Approved |
Reviewed the Supplemental Investigation Work Plan and Report this date. Groundwater samples were collected from monitoring wells (MW) 1 through 9 and analyzed for gasoline range organics (GRO), diesel range organics (DRO), residual range organics (RRO), benzene toluene, ethylbenzene, and xylenes (BTEX), and polycyclic aromatic hydrocarbons (PAHs). The results found contaminants at concentrations greater than ADEC groundwater cleanup levels in all the wells except MW2, MW4, and MW9. There was a light non-aqueous phase liquid (LNAPL) in MW7 which was sent to the laboratory for petroleum hydrocarbon identification analysis. MW7 had a GRO concentration of 77 milligrams per liter (mg/L) and a DRO concentration of 4.1 mg/L. All other GRO results were below cleanup levels. MW7 is located less than 15 feet (ft.) from the store at the gas station. |
Danielle Duncan |
| 1/7/2019 |
Update or Other Action |
Per the consultant, the earthquake may have damaged and/or delayed the sample analyses so the report won't be available for a few weeks. |
Danielle Duncan |
| 3/18/2019 |
Site Characterization Report Approved |
Approved the 2018 Site Characterization this date. The groundwater contamination was delineated and the plume appears to be confined to the property with the exception of MW10 located on the south side of the street. However, the extent of soil contamination is only delineated to the northwest. A recommendation for further vapor intrusion assessment in the form of sub-slab soil gas sampling and the ADEC concurs. |
Danielle Duncan |
| 6/28/2019 |
Site Characterization Workplan Approved |
Approved the Supplemental Site Characterization Work Plan this date. The work plan describes groundwater sampling, subslab soil gas sampling, aquifer testing, and a review of fuel system monitoring and tightness testing records. |
Danielle Duncan |
| 7/10/2019 |
Site Visit |
Site visit with P. Grabau during field work. |
Danielle Duncan |
| 12/23/2019 |
Document, Report, or Work plan Review - other |
On this date, ADEC received the draft Supplemental Site Characterization Report Valley Tesoro submitted by Farallon Consulting and dated October 24, 2019. A subslab soil gas sample collected beneath the site building store contained contaminant concentrations above ADEC Commercial Subslab Soil Gas target levels with 1,2,4-TMB at 3,100 ug/m3, ethylbenzene at 1,800 ug/m3, xylenes at 15,000 ug/m3 and benzene at 5,200 ug/m3. Groundwater from monitoring wells MW-1 through MW-16 were sampled. MW-17 could not be sampled due to damage beyond repair. Monitoring wells MW-9, MW-11, and MW- 16 were the only wells below ADEC Table C Cleanup levels. MW-14, the most contaminated monitoring well, contained DRO at 2.9 mg/L, GRO at 85.6 mg/L, benzene at 1,590 ug/L, toluene at 9,570 ug/L, ethylbenzene at 5,240 ug/L, and xylenes at 25,900 ug/L. MW-10 was the only well to contain RRO above table C cleanup levels at 3.08 mg/L. MW-7, MW-8, and MW-10 were also analyzed by 8260 and 8270 and contained contaminant concentrations above Table C cleanup levels. MW-7, the most contaminated of these three wells, contained 1,2,4-TMB at 2,180 ug/L, 1,3,5-TMB at 345 ug/L, naphthalene at 443 ug/L, 1-methylnaphthalene at 33.7 ug/L, and 2-methylnaphthalene at 58.7 ug/L. A groundwater seepage velocity of 12.5 feet per year was estimated. Groundwater elevations were 2.5 to 5.7 feet lower than the November 2018 sampling event. Groundwater flow was to the southeast during this July 2019 sampling event, but south-southwest during the November 2018 sampling event. |
Grant Lidren |
| 8/12/2020 |
Site Characterization Workplan Approved |
ADEC approved the Monitoring Well Installation and Vapor Intrusion Assessment Work Plan, Valley Tesoro submitted by Farallon and dated June 23, 2020. The scope of work includes installation and decommissioning of monitoring wells, groundwater monitoring, and a vapor intrusion assessment. |
Grant Lidren |
| 3/30/2021 |
Document, Report, or Work plan Review - other |
On March 29, 2021 ADEC received "Monitoring Well Installation and Vapor Intrusion Assessment Report" dated March 26, 2021. The report summarizes soil sampling and installation of monitoring wells MW 18 through MW 21; site-wide groundwater monitoring and sampling; collection of a subslab soil gas sample beneath the Site building; and indoor and outdoor air sampling. |
Rachael Petraeus |
| 6/15/2021 |
Site Characterization Report Approved |
On June 15, 2021 ADEC approved the "Monitoring Well Installation and Vapor Intrusion Assessment Report." |
Rachael Petraeus |
| 7/15/2021 |
Document, Report, or Work plan Review - other |
On July 15, 2021 ADEC received "Groundwater and Vapor Intrusion Monitoring Work Plan Valley Tesoro
9102 Mendenhall Mall Road Juneau, Alaska" dated June 25, 2021. The work plan proposes groundwater monitoring and vapor intrusion assessment activities at the Valley Tesoro service station. |
Rachael Petraeus |
| 8/16/2021 |
Site Characterization Workplan Approved |
On August 16, 2021 ADEC approved "Groundwater and Vapor Intrusion Monitoring Work Plan Valley Tesoro 9102 Mendenhall Mall Road Juneau, Alaska" dated August 16, 2021. The work plan proposes groundwater monitoring and vapor intrusion assessment activities at the Valley Tesoro service station.
|
Rachael Petraeus |
| 5/10/2022 |
Document, Report, or Work plan Review - other |
The ADEC reviewed the "2021 Groundwater & Vapor Intrusion Monitoring Results" Report and provided comments. The ADEC requested comments be addressed and the report be re-submitted by June 10, 2022. |
Flannery Ballard |
| 6/1/2022 |
Document, Report, or Work plan Review - other |
The ADEC reviewed the "Valley Tesoro, 2022 Vapor Intrusion Monitoring Results" report and provided comments. The ADEC requested comments be addressed and the report be re-submitted by July 1, 2022. |
Flannery Ballard |
| 7/12/2022 |
Workplan Requested |
The ADEC requested a work plan to survey monitoring wells 18-21, to fix the casing issue with MW-15 (which is reported to have risen 6-8 inches above the ground surface), and to potentially consider a removal or remediation action for impacted soil as contamination in ground is at such elevated levels. Work plan is requested to be submitted by November 4, 2022. |
Flannery Ballard |
| 7/12/2022 |
Site Characterization Report Approved |
The ADEC approved the "2021 Groundwater & Vapor Intrusion Monitoring Results" report. Between September 14-16, 2021 all monitoring wells (MW1-21) with the excepetin of MW-18 which could not be located day-of, were sampled for gasoline range organics (GRO), diesel range organics (DRO), residual range organics (RRO), polycyclic aromatic hydrocarbons (PAHs), and volatile organic compounds (VOCs). DRO was detected in 5 monitoring wells at concentrations exceeding ADEC cleanup levels (CULS), with a maximum value of 6.39 mg/L in MW-19. GRO exceeded ADEC CULS in six monitoring wells, with a maximum value of 155 mg/L. Additionally, there were exceedances of benzene, toluene, ethylbenzne, xylenes, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene.
As the hydrocarbon plume extends beneath the building, vapor intrusion has also been a concern. Samples were taken sub-slab, indoor (at the cash register, and in the back office), and outside near the two entrances to the building. At the sub-slab sample location SG1, there were exceedances of benzene (2,300 ug/m3), and xylenes (8,200 ug/m3), above ADEC Commercial Sub-Slab Gas Target Levels. There were additionally multiple instances where the reporting limit was greater than the target levels, and so it is assumed that 1,2,4-trimethylbenzne, ethylbenzne, and napthalene are also present at levels that exceed target levels. At this time, it does not appear that the sub-slab soil gas concentrations are impacting indoor air as all samples taken indoor and outdoor were beneath ADEC target levels.
|
Flannery Ballard |
| 9/8/2022 |
Document, Report, or Work plan Review - other |
A request to alter the scope of work at the Valley Tesoro was submitted to the ADEC on August 25, 2022. The submittal proposes to 1). discontinue sub-slab sampling as a trend over 4 sampling events has been established and sampling will focus on indoor air quality, 2). reduce sampling frequency of MW-2, MW-4, MW-7, and MW-13 to biennially, 3). remove the analysis of select PAHs and VOCs for groundwater, and 4). revise the list of target analytes for VI to include only benzene, ethylbenzene, xylenes, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, and naphthalene. |
Flannery Ballard |
| 9/12/2022 |
Document, Report, or Work plan Review - other |
The ADEC requested an additional round of sampling at the current scope of work before a reduction is considered. |
Flannery Ballard |
| 10/28/2022 |
Update or Other Action |
ADEC extended the deadline for WP submission to December 2, 2022. Consultant informed ADEC that additional monitoring wells have been identified as missing due to construction on a neighboring property. Additional work will need to be added to the scope of the next WP. |
Flannery Ballard |
| 12/1/2022 |
Site Characterization Workplan Approved |
The ADEC approved the "Delta Western, LLC Valley Tesoro Well Repair and Survey Work Plan", dated November 28, 2022. The work plan proposes to locate and repair monitoring wells 15, 17, and 18 that have not been located since 2021. If damaged, the wells will either be repaired or decommissioned at a later date. MW-17-21 will be professionally surveyed, as they have not been surveyed since installation. |
Flannery Ballard |
| 5/3/2023 |
Document, Report, or Work plan Review - other |
The DEC reviewed the 2022 Groundwater & Vapor Intrusion Monitoring Results report and provided a comment letter requesting updates before the report should be re-submitted for review. |
Flannery Ballard |
| 7/10/2023 |
Site Characterization Report Approved |
The ADEC approved the revised version of the 2022 Groundwater and VI report, re-submitted June 16. Report uploaded. |
Flannery Ballard |
| 10/11/2023 |
Document, Report, or Work plan Review - other |
A work plan was approved. The work plan proposes excavation in the former dispenser and former UST source areas. Soil will be segregated between presumed clean and presumed dirty. Presumed dirty will be transported to Bicknell for treatment and disposal. Presumed clean soil will be screened, sampled, and used as backfill before sample results come back. Wells MW-14, MW-7, MW-13, MW-19, and MW-8 will be removed during the excavation efforts. The need to replace the wells will be evaluated at a later time. Petrofix may be applied in the base of the excavation. |
Lisa Krebs-Barsis |
| 3/13/2024 |
Document, Report, or Work plan Review - other |
In May 2023 work was conducted to locate and repair several monitoring wells. MW-15 was located but approximately 3.7 feet of gravel had fallen into the well. Gravel was removed and the well monument was replaced. Monitoring wells MW-17 and MW-18 were located undamaged. A survey was conducted on all of the wells to determine the elevation compared to MW-4. |
Lisa Krebs-Barsis |
| 3/13/2024 |
Site Characterization Report Approved |
A report documenting the March 2023 vapor intrusion monitoring results was submitted in September 2023. Sub-slab soil gas samples were collected from the retail store and both indoor and outdoor air samples were collected. Benzene exceeded both residential and commercial target levels in sub slab sample SG-1 at 420 µg/m3. Xylenes was detected in SG-1 and SG-2 but the concentrations were below both residential and commercial target levels for the first time since sampling started in 2019. In both SG-1 and SG-2 dilution caused laboratory reporting limits to exceed target levels for some contaminants of concern. Two outdoor air samples and two indoor air samples were also collected. None of the analytes exceeded residential or commercial target levels at any of the four sample locations. |
Lisa Krebs-Barsis |
| 3/20/2024 |
Site Characterization Report Approved |
ADEC received and approved "Valley Station Piping and Dispensers Site Assessment Report". The report details the closure of piping, dispenser sumps, and appurtenances from abandoned/removed dispensers on the south and southwest of the site. The assessment activities took place November 15, 2023, and the underground storage tank (UST) piping and components were removed on November 16, 2023. Field screening samples were collected every 10 feet along the piping, under the two under-dispenser containments (UDC), and under each of the fuel line fittings using a photoionization detector (PID). Twenty-one field screening samples were collected 1.4 to 2.5 feet below ground surface (BGS) or 0.5 to 1.0 feet below the piping/UDC sumps and fittings. The PID field screening results ranged from 0 to 26.2 parts per million (PPM). Only two screenings, field screening FS3 and FS13 had elevated PID readings. FS3, which was collected from under the southeast corner fitting had a PID reading of 15.1 PPM. Field screening FS13, collected from under the 90-degree elbow fitting that joined the southern dispenser’s fuel line to the main piping run, had a PID reading 26.2 PPM.
Six primary analytical soil samples were collected as well as, one field duplicate, and additional volume at one sampling location was collected for matrix spikes (MS) and matric spike duplicate (MSD). Soil samples were collected at 1.4 to 2.5 feet bgs at locations based on field screening results. All analytical soil samples were analyzed for gasoline range organics (GRO), benzene, toluene, ethylbenzene and xylenes (BTEX), volatile organic compounds (VOCs), Polycyclic aromatic hydrocarbons (PAHs) and Naphthalene. All analytical results were either non-detect or detected well below ADEC 18 AAC 75, Method Two, Tables B1 and B2 migration to groundwater cleanup levels.
|
Kris Dent |
| 6/4/2024 |
Site Characterization Report Approved |
DEC approves the Juneau Valley Cleanup Report. The report details the field activities conducted during and following the removal of piping components and contaminated soil from the Delta Western Juneau Valley Fuel Station, in Juneau, Alaska. During the excavation, 696 locations were field screened using a photoionization detector (PID). Headspace sample readings ranged from 0.1 to 2,311 parts per million (PPM). Analytical samples were collected and analyzed for gasoline range organics (GRO), diesel range organics (DRO), residual range organics (RRO), benzene, toluene, ethylbenzene, and xylenes (BTEX). Analytical results in the east sidewall, north sidewall, and a portion of the west sidewall of the excavation were below Migration to Groundwater (MTG) cleanup levels as listed in 18 AAC 75, Tables B1 and B2. Results for GRO, DRO, and BTEX in the remainder of the excavation were above MTG clean-up levels. |
Kris Dent |
| 8/27/2024 |
Document, Report, or Work plan Review - other |
A work plan was approved. The objective of the investigation effort is to conduct annual groundwater monitoring at the Valley Tesoro Site (Hazard ID 26640) to confirm groundwater flow direction, determine the current concentrations of contamination levels compared to ADEC Table C groundwater cleanup levels, and evaluate the effects of the 2023 remediation efforts. All existing monitoring wells at the site will be inspected and gauged to determine depth-to-water. Groundwater samples will be collected from a total of 14 wells and the samples will be analyzed for gasoline range organics (GRO), diesel range organics (DRO), residual range organics (RRO), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). Monitoring wells MW-2, MW-4, MW-7, and MW-13 are on a biennial sampling plan and will be inspected and gauged but will not be sampled during the 2024 field activities |
Kris Dent |
| 3/11/2025 |
Document, Report, or Work plan Review - other |
ADEC approved the "September 2024 Groundwater Monitoring Report – Delta Western Juneau Valley Fueling Station". The report describes the annual groundwater monitoring at the Delta Western Juneau Valley Fueling station in September 2024. The primary objectives were to assess the remaining monitoring wells, confirm groundwater flow direction, collect groundwater samples to determine the current concentrations of contaminants, and evaluate the effectiveness of the 2023 remediation efforts.
Sixteen of the 21 monitoring wells were inspected and gauged. The remaining five wells were determined to be either removed or buried and were not located. Of the 16 located wells, 13 were sampled. The two remaining wells (MW2 and MW4) are scheduled to be sampled biennially, which will occur in 2025. Monitoring Well 14 (MW14) is only scheduled to be gauged yearly and not sampled.
Analytical groundwater samples were collected and analyzed for gasoline range organics (GRO), diesel range organics (DRO), residual range organics (RRO), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). Four of the 13 wells (MW5, MW6, MW10, and MW16) sampled during the September 2024 effort had exceedances of several analytes above ADEC’s Table C groundwater cleanup levels. Results for MW5, MW6, and MW10 had similar exceedances to historical results. Monitoring Well 16 (MW16) had an exceedance of RRO (2,170 µg/L) above ADEC’s Table C groundwater cleanup of 1,100 µg/L. This exceedance is anomalous and has not historically been above cleanup levels in this well.
ADEC agrees with the recommendations for future site. These recommendations are to continue monitoring the site's groundwater gradient, continue the annual September groundwater analytical sampling, perform the suggested maintenance on the monitoring wells to minimize surface water intrusion, and locate and incorporate monitoring wells 14 and 17 (MW14 and MW17) into the analytical sampling plan. A work plan was requested.
|
Kris Dent |
| 7/17/2025 |
Site Characterization Workplan Approved |
A work Plan for the 2025 field season was received and approved. The objective of the investigation effort is to conduct annual groundwater monitoring at the Valley Tesoro Site (Hazard ID 26640) to confirm groundwater flow direction and determine the current concentrations of contamination levels compared to ADEC Table C groundwater cleanup levels. Groundwater samples will be collected from a total of 16 wells (17 wells if monitoring well 17(MW-17) can be located). Samples will be analyzed for gasoline range organics (GRO), diesel range organics (DRO), residual range organics (RRO), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). Monitoring wells MW-2 and MW-4 are on a biennial sampling plan and will be sampled during the 2025 field activities. |
Kris Dent |
| 3/26/2026 |
Document, Report, or Work plan Review - other |
ADEC approved the "September 2025 Groundwater Monitoring Report", dated March 2026. The report describes the annual groundwater monitoring at the Delta Western Juneau Valley Fueling Station conducted in September 2025. The primary objectives were to assess all 17 remaining monitoring wells, confirm the groundwater flow direction, and collect groundwater samples to determine current contaminant concentrations. Analytical groundwater samples were collected and analyzed for gasoline range organics (GRO), diesel range organics (DRO), residual range organics (RRO), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). Eight of the 17 wells (MW2, MW3, MW4, MW5, MW6, MW10, MW14, and MW17) during the September 2025 sampling effort had exceedances of several analytes above ADEC’s Table C groundwater cleanup levels. |
Kris Dent |
