| Action Date |
Action |
Description |
DEC Staff |
| 8/15/1993 |
Preliminary Assessment Approved |
(Old R:Base Action Code = SA1R - Phase I SA Review (CS/LUST)). Preliminary sampling indicates soil and water contamination due to AST release. |
Scott Rose |
| 9/23/1993 |
Site Characterization Report Approved |
(Old R:Base Action Code = RI - Remedial Investigation). Remedial Investigation included installation of soil borings and monitoring wells. Benzene in groundwater at 1.1 mg/l. |
Scott Rose |
| 8/1/1994 |
Site Characterization Workplan Approved |
(Old R:Base Action Code = SA2R - Phase II SA Review (CS)). Phase II assessment approved. The department requested additional borings and monitoring wells. |
Scott Rose |
| 10/19/1995 |
Site Added to Database |
Site added. |
Scott Rose |
| 10/19/1995 |
Site Ranked Using the AHRM |
Initial ranking. |
Scott Rose |
| 1/17/2001 |
Update or Other Action |
2000 Contaminated Soil Excavation and Groundwater Monitoring Report, PS 1 Former Gasoline Tank Area, Alyeska Spill Number 1992348 submitted to ADEC. Approximately 150 cubic yards of contaminated soil were removed from the excavation down to the suprapermafrost groundwater. An impermeable liner was installed after the excavation was complete, and the AS system was reassembled. Analytical results from groundwater samples indicate that petroleum hydrocarbon impact remains in the area north of the former gasoline ASTs site. DRO concentrations increased in MW-1, MW-2, MW-8, MW-9 and MW-10. GRO and benzene levels also increased in MW-9. MW-10 has increased GRO and BTEX concentrations as well. IT states that some of the increases seen in petroleum hydrocarbon concentrations in the immediate area of the AS system is likely due to the excavation activities releasing the contaminants from soil to the groundwater. IT recommends continued operation of the AS system and continued groundwater monitoring in the vicinity of the former gasoline tank area. |
Deborah Williams |
| 8/6/2001 |
Cleanup Plan Approved |
Plan approval for start up of air sparging system and annual groundwater monitoring. |
Renee Evans |
| 4/9/2003 |
Update or Other Action |
Alyeska submitted a groundwater monitoring report for the former PS1 Gasoline Tank Area. Analytical results from the groundwater samples collected at the site showed that the concentrations of petroleum hydrocarbons are relatively stable at most monitoring wells. The most significant exceptions include monitoring wells in the center of the contaminant plume (MW-8, MW-9, and MW-10), which may demonstrate a northeastern migration of the dissolved hydrocarbon plume. No petroleum hydrocarbons were detected in samples collected from the nearest surface water body off of the eastern edge of the tank farm gravel pad.
Also, a small area of isolated DRO contamination east of Tank 117 seems to exist separately from the gasoline contamination resulting from the FGTA.
SLR recommend the continuation of annual groundwater monitoring. |
Deborah Williams |
| 3/30/2004 |
Update or Other Action |
Alyeska submitted report entitled 2003 Former Gasoline Tank Area Ground Water Monitoring Report, PS 1. Ground water samples collected from the PS 1 FGTA show that concentrations of dissolved petroleum hydrocarbons remain above ADEC ground water cleanup levels. Within the source area there were benzene levels up to 10.3 ppm and downgradient benzene up to 9.12 ppm. Samples collected in 2003 support previous observations of northeasterly migration of the petroleum contamination, notable in monitoring wells MW-8, MW-9, MW-15, and MW-19. Monitoring well MW-10, closest to the source, shows an overall reduction since 1994 in dissolved hydrocarbons, while monitoring wells MW-8, MW-9 and MW-15, downgradient from the source, exhibit overall increases.
The area of ground water impacted above ADEC cleanup levels appears to have increased since the 2002 sampling. However, based on ground water samples collected from the edge of the pad and from surface water proximal to the PS1 pad, it is apparent that impacted groundwater is not currently migrating off pad.
SLR recommends the continuation of the annual ground water and surface water sampling program in 2004, as well as the continued operation of the AS system. |
Deborah Williams |
| 3/14/2005 |
Update or Other Action |
ADEC reviewed SLR's PS 1 Former Gasoline Tank Area 2004 Groundwater Monitoring and Remediation Report. Samples collected in 2004 support previous observations of a northeasterly migration of the petroleum contamination. Monitoring well MW-10, which is located closest to the source, shows an overall reduction in dissolved hydrocarbons since 1994. Downgradient monitoring wells MW-8 and MW-15 indicate consistently increased concentrations of dissolved hydrocarbons. In addition, the lateral extent of groundwater with concentrations exceeding ADEC cleanup levels has increased slightly during the last two years. Analytical results from groundwater and surface water samples collected adjacent to the pad, were non-detect. Therefore, there does not appear to be migration from the pad to the surface water. |
Deborah Williams |
| 4/5/2006 |
Update or Other Action |
ADEC received PS 1 Former Gas Tank Area 2005 Groundwater Monitoring and Remediation Report. GW analytical results collected from monitoring wells in 2005 show that concentrations of dissolved petroleum hydrocarbons remain above ADEC groundwater cleanup levels. MW-10, which is located closest to the source, shows an overall reduction in dissolved hydrocarbons since 1994. However, downgradient MW-8 demonstrates consistently increased concentrations of dissolved hydrocarbons. From the data, it is apparent that impacted ground water currently is not migrating off-pad.
SLR recommends the continuation of the annual groundwater and surface water sampling program in 2006, as well as the continued operation of the AS system. |
Deborah Williams |
| 3/14/2007 |
Update or Other Action |
ADEC received the SLR report on the 2006 Groundwater Monitoring and Remediation for the PS 1 Former Gas Tank site. According to the report, there still appears to be a northeasterly migration of petroleum contamination. MW-10 which is located closest to the source shows an overall reduction in dissolved hydrocarbons since 1994. However, downgradient MW-8 demonstrates consistently increased concentrations of dissolved hydrocarbons. |
Deborah Williams |
| 3/16/2007 |
Exposure Tracking Model Ranking |
Initial ranking completed. |
Deborah Williams |
| 3/7/2008 |
Update or Other Action |
Receipt of Pump Station 1 Former Gasoline Tank Area 2007 Ground Water and Remediation Report. Nine groundwater wells and two surface water locations were sampled. Overall results appear to be fairly consistent with past years data, including no BTEX or PAH in surface water. Since its installation, MW-15 has exhibited particularily high DRO concentrations which is thought to be due to therminol contamination from a leaking pipe at Tank 117. DO results suggest that biodegradation may be occuring. Air sparging (AS) unit was not operated due to interference that was created by recent sludge treatment activities. SLR recommends continued monitoring with MNA parameters in groundwater and continued operation of AS or more excavation. Report review including laboratory QA/QC conducted 3/26/08. |
Keather McLoone |
| 3/13/2009 |
Document, Report, or Work plan Review - other |
Receipt of Pump Station 1 Former Gasoline Tank Area 2008 Ground Water Monitoring and Remediation Report by SLR. In 2008, soil was excavated (~150 cubic yards) from the original source area of the gasoline contamination. Contaminated soil above the suprapermafrost grond water table was removed but some contaminated soil remains beneath this depth. Eight excavation confirmation samples were collected from 2.5 - 4 ft bgs and all exceeded most conservative criteria (0.025 mg/kg) benzene. Two samples collected from 3.5 and 4 ft bgs also exceeded criteria for ethylbenzene, xylenes, and toluene. Samples were also analyzed for GRO, DRO, RRO, and PAHs. Groundwater, including natural attenuation parameters, and surface water monitoring. Impacted groundwater is not migrating off-pad. Results in MW-15 much reduced from historic data (2 orders of magnitude reduction). Monitoring to continue in 2009.
The air sparging system was decommissioned during excavation of soil from within its footprint. Alyeska intends to install an AST in this vicinity in 2009.
Review included laboratory review checklist.
GRO/BTEX results for SS-2 should be considered rejected and usable as a screening value due to too much uncertainty in data quality. Methanol appeared to have leaked in transit and lab added another aliquot of MeOH (extract already extracted soil). Furthermore, the field surrogate recovery was outside of acceptance criteria (biased high).
GRO/BTEX results for SS-3 should be considered estimated with a high bias due to surrogate recovery more than 2 times the upper limit of acceptance criteria and no dilution performed.
DRO/RRO/PAH results for SS-2 should be considered estimated as prep and analysis were performed on container that was broken and 50 percent "salvageable" upon receipt. |
Keather McLoone |
| 6/4/2009 |
Document, Report, or Work plan Review - other |
Approval of 2009 Pump Station 1 Former Gasoline Tank Area Water Monitoring Work Plan. When the PS01 gravel pad has thawed, a groundwater and surface water event will be conducted, likely August or September. Thirteen groundwater locations and 2 surface water locations will be sampled. Groundwater sampling to include DO, ferric/ferrous iron, nitrite/nitrate, and sulfate/sulfide as it has in the past. Contaminant analyses to include BTEX/GRO/DRO/PAH in groundwater and TAH/TAqH in surface water. Two well installations are also planned - one to replace MW-10 which was destroyed and an additional well to be installed NE of MW-10. DEC comment on workplan regarding collection of MNA parameters and the importance of understanding the limitations and interferences of measurements made using techniques that expose the water to ambient air or ORP measurements are not stabilized. |
Keather McLoone |
| 5/10/2010 |
Document, Report, or Work plan Review - other |
Review of Pump Station 1 Former Gasoline Tank Area 2009 Remediation and Groundwater Monitoring Report. Groundwater sampling, surface water sampling, and monitoring well installation was conducted in 2009. MNA parameters were also assessed. Surface water results do not indicate offsite migration. Groundwater results contain benzene, toluene, ethylbenze, xylenes, GRO, and DRO above Table C. No remediation was conducted during 2009. |
Keather McLoone |
| 6/18/2010 |
Document, Report, or Work plan Review - other |
Review of Pump Station 1 Former Gasoline Tank Area 2010 Water Monitoring Workplan received June 15, 2010. A single groundwater event of all onsite wells and including MNA parameters is planned when the PS 01 gravel pad thaws. |
Keather McLoone |
| 4/11/2011 |
Document, Report, or Work plan Review - other |
Date of receipt of Pump Station 1 Former Gasoline Tank Area 2010 Water Monitoring Report. Eight groundwater and two surface water locations were sampled in 2010. Groundwater samples were also collected for MNA parameters. Groundwater results are still above Table C but surface water samples suggest that contamination is not migrating off the pad. |
Keather McLoone |
| 7/5/2011 |
Document, Report, or Work plan Review - other |
Date of receipt of Pump Station 1 Former Gasoline Tank Area 2011 Water Monitoring Workplan. Alyeska plans to conduct a single suprapermafrost and surface water sampling event. |
Keather McLoone |
| 3/23/2012 |
Document, Report, or Work plan Review - other |
Date of receipt of 2011 Water Monitoring Report. Only nine of 17 wells were sampled due to insufficient water (7) or well damage (1). Exceedances for GRO, DRO, benzene, and/or toluene were found in samples collected from five of the nine wells. High DRO concentrations suggest product present which should be measured in the future. Two surface water samples collected showed concentrations below applicable criteria. TAH and TAqH are still not calculated correctly but would not have exceeded regardless. MNA parameters also collected at the nine wells sampled. Ferric iron, alkalinity, and nitrite were performed using field test kits. Evaluation of quality of MNA data also made difficult because calibration information, etc. for field measured parameters not included with report. Total iron, sulfate, sulfide, and total nitrate plus nitrite were performed by the laboratory. SLR plans to resurvey the wells due to frost jacking issues. |
Keather McLoone |
| 6/19/2012 |
Site Characterization Workplan Approved |
Approved workplan to monitor groundwater and surface water, perform maintenance on monitoring wells, and measure Monitored Natural Attenuation (MNA) parameters, to include NOx, SO4, Fe2/Fe3. SLR plans to measure PAHs in 20% of wells this year, so I requested measurement at key wells downgradient of source area (MW-9, 19, & 17) as a minimum to track plume migration. |
Richard Bernhardt |
| 2/26/2013 |
Site Characterization Report Approved |
Field work occurred between 2 & 6 Aug 2012. Eleven of 17 MWs and 2 surface water locations were sampled. The remaining MWs were either dry or damaged. GRO remained over cleanup levels in MWs 8, 9, & 91. DRO remained over cleanup levels in MWs 3, 9, 14, & 15. Benzene remained over cleanup levels in MWs 8, 9, 18, 19, & 20. Maximum COCs were detected as follows: GRO - MW-19 = 14.4mg/L; DRO - MW-15 = 206mg/L; and Benzene - MW-9 = 3.91mg/L. COCs (including PAHs) were not detected in surface water samples. |
Richard Bernhardt |
| 3/15/2013 |
Update or Other Action |
Updated coordinates based on comparison between the 2012 work report and Google Earth imagery. |
Richard Bernhardt |
| 4/23/2013 |
Exposure Tracking Model Ranking |
A new updated ranking with ETM has been completed for source area 72719 Benzene contamination. |
Richard Bernhardt |
| 5/24/2013 |
Site Characterization Workplan Approved |
Received and approved a work plan to conduct a single groundwater and surface water monitoring event, install up to three new monitoring wells, and decommission two wells. |
Richard Bernhardt |
| 2/24/2014 |
Site Characterization Report Approved |
On this date, ADEC received the 2013 Water Monitoring Report Pump Station 1 Former Gasoline Tank Area dated February 2014 submitted by Alyeska. Groundwater and surface water monitoring activities were conducted on August 3rd and 4th. Only 15 out of 17 wells were sampled due to inaccessibility to MW-10 and MW-21. Additionally due to inaccessibility, MW-4, MW-16, and MW-17 were not replaced and MW-10 and MW-13 were not decommissioned. Monitoring wells MW-8, MW-9, MW-14, MW-15, MW-18, and MW-19 contained contaminant concentrations above ADEC cleanup levels with GRO up to 19.2 mg/L (MW-19), DRO up to 102 mg/L (MW-15) and benzene up to 4.97 mg/L (MW-19). The two surface water samples collected did not contain TAH or TAqH above applicable criteria. Groundwater is generally flat with a trend toward the northeast or edge of pad. The GW elevations were generally lower than the 2012 GW elevations. |
Grant Lidren |
| 6/10/2014 |
Site Characterization Workplan Approved |
On this date, ADEC approved the 2014 Water Monitoring Work Plan Pump Station 1 Former Gasoline Tank Area submitted by SLR, dated May 2014. |
Grant Lidren |
| 4/24/2015 |
Site Characterization Report Approved |
On this date, ADEC received the 2014 Water Monitoring Report Pump Station 1 Former Gasoline Tank Area submitted by SLR dated April 2015. Groundwater and surface water monitoring activities were conducted on August 21st and 24th. Seven out of the eleven monitoring wells sampled contained concentrations of contaminants above ADEC cleanup levels. These seven MWs: MW-3, MW-8, MW-9, MW-15, MW-18, MW-19, and MW-20 contained GRO up to 40.7 mg/L (MW-9), DRO up to 120 mg/L (MW-15), benzene up to 6.58 mg/L (MW-9), toluene up to 10.4 (MW-9), and ethylbenzene up to 0.732 (MW-9). Note: benzene and GRO concentrations in MW-19 have increased since 2009. Due to inaccessibility, MW-4, MW-16, and MW-17 were not replaced and MW-10 was not decommissioned as planned. However, the monitoring wells MW-14 and MW-21 were decommissioned. Two surface water samples collected did not contain TAH or TAqH above applicable criteria. Groundwater is generally flat with a trend toward the northeast or edge of pad. The GW elevations were generally lower than the 2012 GW elevations. |
Grant Lidren |
| 7/6/2015 |
Site Characterization Workplan Approved |
ADEC Received and reviewed the 2015 Water Monitoring Work Plan Pump Station 1 Former Gasoline Tank Area submitted by SLR and dated May 2015. |
Grant Lidren |
| 3/29/2016 |
Site Characterization Report Approved |
On this date, ADEC received the 2015 Water Monitoring Report Pump Station 1 Former Gasoline Tank Area submitted by SLR dated March 2016. In November 2015, seven MWs were installed replacing five historic wells adding two new MWs on the eastern side of the pad Groundwater and surface water monitoring activities were conducted between August 24th and 27th 2015. Thirteen MWs sampled including: MW-2, MW-3, MW-4, MW-8, MW-9, MW-12, MW-13 and MW-15 through MW-20; contained GRO up to 16.8 mg/L (MW-9), DRO up to 69 mg/L (MW-15), benzene up to 3.93 mg/L (MW-19), and toluene up to 2.27 (MW-9). MW-7 and MW-14 were not sampled due to damage. These monitoring wells and monitoring well MW-4, MW-16, and MW-17 were replaced with MW-4R, MW-7R, MW14R, MW16R, and MW-17R. MW-10 was not replaced as planned due to lack of access. Additionally, MW-22 and MW-23 were installed along the eastern edge of the pad. Two surface water samples collected did not contain TAH or TAqH above applicable criteria. Groundwater is generally flat with a trend toward the northeast or edge of pad. The GW elevations were generally higher than the 2012 GW elevations. |
Grant Lidren |
| 6/29/2016 |
Site Characterization Workplan Approved |
ADEC Received and reviewed the 2016 Water Monitoring Work Plan Pump Station 1 Former Gasoline Tank Area submitted by SLR and dated June 2016. |
Grant Lidren |
| 2/15/2017 |
Site Characterization Report Approved |
On this date, ADEC received the 2016 Water Monitoring Report Pump Station 1 Former Gasoline Tank Area submitted by SLR dated January 2017. A total of 16 MWs and two SW locations were sampled and the three damaged MWs: MW-4, MW-16, and MW-10 were decommissioned. The 16 MWs sampled including: MW-2, MW-3, MW-4R, MW-8, MW-9, MW-12, MW-13, MW-14R, MW-15R, MW-16R, MW-17 through MW-20, MW-22 and MW-23. Groundwater samples collected from seven of these 16 MWs contained contaminant concentrations above ADEC clean levels with GRO up to 30.8 mg/L (MW-9), DRO up to 106 mg/L (MW-14R), benzene up to 3.96 mg/L (MW-9), toluene up to 5.18 (MW-9) and xylenes up to 8.31 mg/L (MW-9). Note: newly installed MW-23 installed to the east edge of plume contained benzene at 0.0107 mg/L. Two surface water samples collected did not detectable concentrations of TAH or TAqH. Groundwater is generally flat with a trend toward the northeast or edge of pad. The GW elevations were 1.01 ft. lower than the 2015 GW elevations. |
Grant Lidren |
| 6/6/2017 |
Site Characterization Workplan Approved |
ADEC received and reviewed the 2017 Water Monitoring Work Plan Pump Station 1 Former Gasoline Tank Area submitted by SLR and dated May 2017. MW-9 and MW-14 will be analyzed for petroleum VOCS by method 8260. This work plan is for approval of groundwater monitoring for three years: 2017, 2018, and 2019. |
Grant Lidren |
| 3/30/2018 |
Site Characterization Report Approved |
On this date, ADEC received the 2017 Water Monitoring Report Pump Station 1 Former Gasoline Tank Area submitted by SLR dated January 2017. A total of 16 monitoring wells (MWs) and three surface water (SW) locations were sampled. The 16 MWs sampled including: MW-2, MW-3, MW-4R, MW-8, MW-9, MW-12, MW-13, MW-14R, MW-15R, MW-16R, MW-17 through MW-20, MW-22 and MW-23. Groundwater samples collected from nine of these 16 MWs contained contaminant concentrations above ADEC table C groundwater clean levels. Monitoring well MW-9 contained the highest concentrations of: GRO up to 14.8 mg/L, toluene up to 2.92 mg/L, ethylbenzene up to 0.803 mg/L, xylenes up to 4.29 mg/L, 1,2,4-trimethylbenzene up to 0.148 mg/L, and naphthalene up to 0.00183 mg/L. Monitoring wells MW-15 and MW-19 contained the highest concentrations of DRO up to 14.3 mg/L and benzene up to 2.5 4QH mg/L respectively. Note: MW-23 at the east edge of plume adjacent to surface water sampling areas SW-1 and SW-3 contained benzene at 0.0505 mg/L and ethylbenzene at 0.025. Three surface water samples collected did not detectable concentrations of TAH or TAqH. In general, groundwater flow trends towards the northeast edge of the pad with a gradient of approximately 0.007 to 0.012 ft per ft. The average groundwater elevation in 2017 was 1.46 ft higher than in 2016. |
Grant Lidren |
| 5/25/2018 |
Document, Report, or Work plan Review - other |
On this date, ADEC received the addendum to Water Monitoring Work Plan Pump Station 1 Former Gas Tank Area submitted by SLR and dated May 25, 2018. Petroleum VOCs analysis will be added to all MWs for 2018 and 2019. |
Grant Lidren |
| 7/31/2018 |
Site Visit |
Visited site on this date with Alyeska and SLR. |
Grant Lidren |
| 3/4/2019 |
Site Characterization Report Approved |
ADEC received the 2018 Water Monitoring Report Pump Station 1 Former Gasoline Tank Area submitted by SLR dated February 2019. A total of 17 monitoring wells (MWs) and three surface water (SW) locations were sampled. The 17 MWs sampled including: MW-2, MW-3, MW-4R, MW-7R, MW-8, MW-9, MW-12, MW-13, MW-14R, MW-15, MW-16R, MW-17R, MW-18 through MW-20, MW-22 and MW-23. Groundwater samples collected from six of these 16 MWs contained contaminant concentrations above ADEC table C groundwater clean levels. Monitoring well MW-19 and MW-9 contained the highest concentrations of GRO up to 18.5 mg/L, benzene up to 2.93 mg/L, xylenes up to 6.39 mg/L 1,2,4-trimethylbenzene up to 0.266 mg/L, 1,3,5-trimethylbenzene up to 0.076 mg/L, and ethylbenzene up to 0.992 mg/L. Monitoring well MW-15 contained the highest concentrations of DRO up to 48.8 mg/L and naphthalene up to 0.00865 mg/L. Note: MW-23 at the east edge of plume adjacent to surface water sampling areas SW-1 and SW-3 contained benzene at 0.0505 mg/L and ethylbenzene at 0.025. Three surface water samples collected did not contain detectable concentrations of TAH or TAqH. In general, groundwater flow trends towards the northeast edge of the pad. The average groundwater elevation in 2018 was 0.72 ft lower than in 2017. |
Grant Lidren |
| 12/20/2019 |
Site Characterization Report Approved |
ADEC received the 2019 Water Monitoring Report Pump Station 1 Former Gasoline Tank Area submitted by SLR dated December 2019. A total of 17 monitoring wells (MWs) and three surface water (SW) locations were sampled. The 17 MWs sampled including: MW-2, MW-3, MW-4R, MW-7R, MW-8, MW-9, MW-12, MW-13, MW-14R, MW-15, MW-16R, MW-17R, MW-18, MW-19, MW-20, MW-22 and MW-23. Groundwater samples collected from seven of these 16 MWs contained contaminant concentrations above ADEC table C groundwater clean levels. Monitoring well MW-19 and MW-9 contained the highest concentrations of GRO up to 24.9 mg/L, benzene up to 2.34 mg/L, xylenes up to 8.46 mg/L 1,2,4-trimethylbenzene up to 0.600 mg/L, 1,3,5-trimethylbenzene up to 0.183 mg/L, ethylbenzene up to 1.7 mg/L, and xylenes up to 8.46 mg/L. Monitoring well MW-15 contained the highest concentrations of DRO up to 5.76 mg/L and naphthalene up to 0.0033 mg/L. Note: MW-23 at the east edge of plume adjacent to surface water sampling areas SW-1 and SW-3 contained benzene at 0.0375 mg/L. Three surface water samples collected contained detectable concentrations of benzene up to 0.00301 mg/L and xylenes up to 0.000354 mg/L, but below water quality standards for the summation of TAH or TAqH. In general, groundwater flow trends towards the northeast edge of the pad. |
Grant Lidren |
| 6/11/2020 |
Site Characterization Workplan Approved |
On this date, ADEC received the Water Monitoring Work Plan Pump Station 1 Former Gasoline Tank Area submitted by SLR and dated June 2020. Groundwater and surface water will be sampled annually during the 2020 and the 2021 field season. |
Grant Lidren |
| 3/14/2022 |
Document, Report, or Work plan Review - other |
A work plan was approved for replacement of two wells at the Equipment Shop site, and six wells at the Former Gas Tank Area. DEC requested sample results for two confirmation samples that will be collected from the potential waste soil stockpile that may result from installing new wells. |
Laura Jacobs |
| 7/19/2022 |
Document, Report, or Work plan Review - other |
A multi-year work plan (2022-2023) and addendum were reviewed for continued remediation efforts and site characterization. These documents were approved with the request that monitoring wells continue to function appropriately and that the screened interval is still in working order. Groundwater samples, surface water samples will be analyzed for petroleum contaminants of concern, in addition, groundwater samples from a subset of wells will be analyzed for microbial genetic census. |
Laura Jacobs |
| 10/21/2022 |
Document, Report, or Work plan Review - other |
DEC finalized review comments after discussing site issues with the RP's representative and consultant. Ongoing monitoring of natural attenuation has occurred over the past five or so years with changes in amendments through time to overcome site challenges. Continued monitoring of supra-permafrost groundwater in available wells and surface water samples from the adjacent ponds have provided evidence of slow attenuation and little movement of amendments or contaminants to surface waters. |
Laura Jacobs |
| 7/20/2023 |
Document, Report, or Work plan Review - other |
DEC has reviewed and approved the Pump Station 1 Former Gasoline Tank Area 2022 Water Monitoring Report submitted January 25, 2023, and Pump Station 1 Former Gasoline Tank Area Sampling and Remediation Work Plan Addendum submitted July 12, 2023. The addendum is in addition to the previously reviewed and approved multi-year work plan titled Water Monitoring Work Plan Pump Station 1 Former Gasoline Tank Area. Monitoring in 2022 showed that the contamination in supra-permafrost groundwater continues to retract and move slightly to the southwest. The gene census results indicate the microbial community with the addition of nitrate and sulfate continue to reduce petroleum hydrocarbon impacts in the groundwater. The 2023 efforts will include monitoring of supra-permafrost groundwater, monitoring of microbial populations and levels of nitrate and sulfate available for microbially-mediated reduction of petroleum hydrocarbon contamination. |
Laura Jacobs |
| 7/24/2024 |
Offsite Soil or Groundwater Disposal Approved |
A Contaminated Media Transport and Treatment or Disposal Approval Form was reviewed and approved for thermal remediation of approximately 4 cubic yards of contaminated soils accumulated from spills on site from July 2019 to July 2024 at Pump Station 1. An additional 2.5 cubic yards of contaminated soils were approved for transport from Check Valve-2 following a 2-gallon crude spill on June 29, 2024. Contaminants of Concern included diesel range organics (DRO), gasoline range organics (GRO), semi-volatile organic compounds (SVOCs), and volatile organic compounds (VOCs). |
Laura Jacobs |
| 7/26/2024 |
Document, Report, or Work plan Review - other |
The 2023 Water Monitoring Report was received January 25, 2024 and approved on this date. The report is a result of long-term monitoring of natural attenuation augmented with sulfate in the form of Epsom salts. Samples collected from the supra-permafrost groundwater and surface water were analyzed to assess potential impacts to surface water adjacent to the Pump Station. It was demonstrated that the gasoline range organics (GRO) plume is stable and exceedances were within historic norms, the diesel range organics (DRO) plume has migrated to the east and expanded to the south, and the extent of the plume associated with benzene, toluene, ethylbenzene, and total xylenes (BTEX) has migrated to the northeast slightly. Surface water sample results indicate suprapermafrost groundwater contamination has not impacted the adjacent surface water. |
Laura Jacobs |
| 7/26/2024 |
Document, Report, or Work plan Review - other |
The 2024-2025 Former Gasoline Tank Area Water Monitoring Work Plan was reviewed and approved for continued supra-permafrost groundwater and surface water monitoring. Samples will be collected in July or August each year from wells MW-2, MW-3, MW-4R, MW-7R, MW-8, MW-9, MW-12, MW-13, MW-14R, MW-15, MW-16R, MW-17R, and MW-18 through MW-20, MW-22, and MW-23. Samples will be analyzed for gasoline range organics (GRO), diesel range organics (DRO), petroleum volatile organic carbons (PVOCs), and sulfate. Monitored natural attenuation (MNA) field parameters will also be measured to evaluate MNA. Surface water samples will be collected from three locations; SW-1, SW-2, SW-3 and analyzed for sulfate, benzene, toluene, ethylbenzene and total xylenes (BTEX), polynuclear aromatic hydrocarbons (PAHs). |
Laura Jacobs |
