Site Report: AT&T Alascom Tok Terminal Station

Site Name:	AT&T Alascom Tok Terminal Station
Address:	1st and East Slana Street, Tok, AK 99780
File Number:	130.38.010
Hazard ID:	2946
Status:	Active
Staff:	Dawn Wilburn, 9072628200 dawn.wilburn@alaska.gov
Latitude:	63.337266
Longitude:	-142.985472
Horizontal Datum:	WGS84

We make every effort to ensure the data presented here is accurate based on the best available information currently on file with DEC. It is therefore subject to change as new information becomes available. We recommend contacting the assigned project staff prior to making decisions based on this information.

Site Chronology
IC / Closure Details
Documents
Associated Sites

Problems/Comments

Diesel (DRO)/Residual range organics (RRO) contaminated soil at the truck fill stand and DRO contaminated soil at the former 4,000-gallon aboveground storage tank (AST) site. Site acreage is 1.61. Four above ground storage tanks (diesel or gasoline) were removed in 1990. Several areas of concern identified in a Phase II Assessment were investigated in 1996. In 1998, contaminated soil was excavated and confirmation samples indicated no further action was necessary in areas identified as (AOI-A, B, C, and E). The extent of petroleum contaminated soils at the 4,000 gallon AST site (AOI-J) was greater than expected and excavation was halted and backfilled after 49.5 cubic yards of soil were removed. 2000 - Three monitoring wells installed on site. DRO contamination in groundwater identified. A soil sample from a borehole adjacent to the former 25,000 gallon AST (AOI-I, toward north end of property), contained DRO at a concentration of 4,300 mg/kg at 5 feet below ground surface. 2006 - Additional monitoring wells and soil excavation were conducted. DRO contamination remains in the soil at the 4,000 gallon AST site under the Power building and at both sites in the base of the excavation (9 feet) above migration to cleanup levels. Soil samples from soil borings detected DRO contamination above cleanup levels from 15-60 feet below ground surface. Two separate groundwater plumes were identified leading generally westward, one from each of the former AST source areas. Groundwater samples in the area of the 25,000 gallon AST had DRO concentrations as high as 18,900 µg/L and appeared the downgradient end appeared to migrate off property. Groundwater samples from the 4,000 gallon AST area had DRO concentrations as high as 39,300 µg/L. Groundwater monitoring has occurred since 2006 with additional wells installed in 2007. In 2009, a bioventing/soil vapor extraction system was installed to remediate deeper soils and operated until 2017. In 2023, several monitoring wells that have been non detect for petroleum contamination were decommissioned with DEC approval. DRO concentration levels in source area wells MW-5 and MW-6 have declined in recent years but still remain above DEC cleanup levels.

Action Information

Action Date	Action	Description	DEC Staff
6/23/1998	Site Ranked Using the AHRM	Initial ranking by staff.	Anne Marie Palmieri
6/23/1998	Update or Other Action	Site accepted into the Voluntary Cleanup Program. Action rescinded and changed to Update on 1/29/03.	Anne Marie Palmieri
7/2/1998	Site Added to Database	DRO/RRO contaminated soil.	Anne Marie Palmieri
8/9/2000	Update or Other Action	Communication from RP: Monitoring well installation completed. Diesel may have migrated to GW. Will call back with analytical results.	David Verbrugge
2/27/2003	Update or Other Action	Responsible Party field changed based on new information from PacificCorp Environmental Remediation Company.	Elizabeth Stergiou
3/7/2005	Update or Other Action	Talked to Lott Hass (503) 813-5517 with PacifiCorp. She stated that the work that was proposed in the July 2001 workplan was completed and monitoring has occurred since that time. A report was not generated because there was no project manager assigned within ADEC. I told her that the site may qualify for a conditional closure since it appears that the groundwater levels at the site are stable or decreasing. She may want to conduct a conceptual site model at the site and include that in the report for a possible conditional closure. She did state that all the monitoring wells on the property are actively being monitored.	Deborah Williams
7/28/2005	GIS Position Updated	Using Figure 1.3 and Site Location from a Phase II site Investigation Tok Junction Terminal, from Woodward-Clyde, dated January 8, 1998, in conjunction with TopoZone Pro, entered the coordinates for this site. Metadata include USGS Topo Map 1:63K, TopoZone Pro Street Map, Black and White Aerial Photo, on a Medium Size Map, View Scale 1:25,000, Coordinate Datum NAD83. Medium to High degree of confidence in accuracy of location.	Alyce Hughey
8/1/2005	Update or Other Action	Sent e-mail to PacifiCorp requesting project status update and copies of submittals subsequent to the Investigation Work Plan July 2001. Soil and GW contamination exceeding ADEC clenaup levels exists at the site.	Donald Seagren
12/16/2005	Update or Other Action	Received no response to August 05 e-mail requesting project status update. Sent another request for update and/or submission of work plans leading to site closure in 2006.	Donald Seagren
12/23/2005	Update or Other Action	Received a response from John Aniello, new PERCO project manager. Sent him a brief summary of outstanding issues remaining to complete assessment & cleanup to reach site closure. Requested work plan be submitted for work during the 06 field season.	Donald Seagren
8/21/2006	Update or Other Action	Reviewed 06 monitoring report. GW occurs at a depth of 55', very low gradient of ~0.001ft/ft; apparent flor to west (parallel to the Tanana river). DRO is the principal contaminant. Other constituents below cleaup levels. Soil contamination appears to go to GW. Aerobic & sulfate-reducing microbes are active in the plume and have significanlty degraded the gw DRO contamination. Additional MWs will be installed to further delineate the contaminant plume prior to developing a CAP. downgradient receptors will be defined as part of the additional study.	Donald Seagren
8/25/2006	Cleanup Plan Approved	Reviewed and approved Interim Soil Cleanup plan	Donald Seagren
8/25/2006	Site Characterization Workplan Approved	Approved GW investigation work plan. Required the RRO analysis for the initial sampling event. If data shows that it is not a concern, RRO will be dropped from future analysis.	Donald Seagren
9/22/2006	Update or Other Action	Approved transport of 600 tons of petroleum contaminated soil to OIT in Fairbanks for thermal rmediation.	Donald Seagren
1/5/2007	Update or Other Action	Reviewed 06 Site Investigation Report. there are 2 distinct contaminant plumes resulting from releases at the I & J tanks. Soil and GW at both areas exceeds ADEC cleanup levels. The J tank plume is delineated in all directions and does not extend beyond the facility property lines. The I tank plume appears to extend beyond the site's west property line. The downgradient plume extent is not delineated and the upgradient GW quality is not characterized. Biodegradation of the plumes is occurring as a result of aerobic respiration, denitrification and possibly sulfate reduction processes. The aquifer assimilative capacity is less than the reported DRO (primary contaminant of concern) concentrations in source area GW, suggesting that natural attenuation is not sufficient to control plume migration. Further monitoring and assessment will be conducted in 2007 to fill in data gaps and better understand the site in order to develop a corrective action plan.	Donald Seagren
2/8/2007	Site Characterization Report Approved	Reviewed the Release & Cleanup final report for the 10 gallon weathered diesel fuel release from the old CANOL Pipeline. The release occurred during removal of sections of the pipeline during site assessment and remediation activities during the summer of 06. The contaminated soil was excavated to belwo migratino to Gw cleanup levels. The contaminated soils was shippe dto OIT in Fairbanks for thermal rmediation. AT&T was informed that no further remedial or invesigative actions are required for this rlease. the Department considers it closed. This closure determination is for the 10 gallon CANOL Pipeline release only. It does not apply to the remainder of the site.	Donald Seagren
4/9/2007	Exposure Tracking Model Ranking		Donald Seagren
5/1/2007	Update or Other Action	Reviewed Construction Completion Report 2006 Interim Cleanup Plan - Soil dated March 07. DRO is remaining contaminant of concern. Two areas AOI-J and AOI-I have DRO soil contamination remaining at depths below 8 to 9 feet that exceeds ADEC cleanup levels of 250 mg/kg. All contaminated soil exceeding ADEC cleanup levels has been excavated given the constraints of equipment and not damaging buildings. the contamianted soils was taken to OIT in Fairbanks for htermal remediation. Further monitoring and assessment work is being planned.	Donald Seagren
7/5/2007	Site Characterization Workplan Approved	Reviewed and approved work plan for installation of 3 additioanl monitor wells and 2 rounds of GW monitroing	Donald Seagren
2/13/2008	Site Characterization Report Approved	Reviewed 2007 Well Installation Report, dated February 08 by ALTA Geosciences, Inc. GW sampling results will be included in a separate report. One soil sample collected at the GW level in each new well. In 2 wells the samples were non-detect for DRO. Results from soil sample @ 53'bgs from boring MW-10 (adjacent ot Center Street) indicated DRO concentration @ 50.5 mg/kg, which is below ADEC cleanup levels.	Donald Seagren
4/1/2008	Update or Other Action	Two monitoring events were preformed in July & October 07. the 07 DRO concentrations in the I-tank and J-tanks source areas have decreased significantly since 06: from 18,900 ug/l to 2,700 ug/l Dro and from 39,000 usg/l to 9,840 ug/l DRO respectively. The extent of the plumes have also decreased such that they no longer appear to extend off site and appear to be largely constrained to the source areas. The 06 soil remediation coupled with aerobic respiration appear to be the principal processes responsible for the decline in the groundwater DRO plumes. Monitroing will continue in 08. Only MW 5 & 6 contained DRO concentrations above the ADEC cleanup levels.	Donald Seagren
6/12/2008	Update or Other Action	Site transferred from Don Seagren to Paul Horwath per Linda Nuechterlein.	Alyce Hughey
1/21/2009	Exposure Tracking Model Ranking	A new updated ranking with ETM has been completed for source area 73921 ast.	Alyce Hughey
4/22/2010	Document, Report, or Work plan Review - other	Reviewed the 2009 Groundwater Monitoring Report, dated February 2010, from ALTA Geosciences, Inc. for Paul Horwath. The groundwater concentrations have reduced significantly since the 2008 sampling events. DRO concentrations exceeding the groundwater cleanup levels remains within two of the monitoring wells during the 2009 sampling events. The newly installed drinking water well located approximately 20 feet northwest of MW-3 did not detect DRO. The purpose of the unidentified well is not known at this time. ADEC has requested additional information regarding the owner’s name, address, contact information, the current or future intention of this water well, and notify the owner of the presence of the petroleum contaminated groundwater plume originating at the Tok Terminal Station site. A bioventing/soil vapor extraction and bio-sparging system was installed between July and October of 2009. The system was initiated in September 2009 and continued until late October 2009 when the system was shut down for the winter. The system is planned on being restarted in the spring of 2010.	Alyce Hughey
5/11/2010	Meeting or Teleconference Held	Meeting with AT&T Inc., ALTA Geosciences and ADEC staff (Paul Horwath and Alyce Hughey) to discuss the Work Plans for the 2010 field season and any project updates.	Alyce Hughey
5/11/2011	Meeting or Teleconference Held	Meeting with AT&T Inc., ALTA Geosciences, Iberdrola Renewables Holdings, Inc. and ADEC staff (Paul Horwath and Alyce Hughey) to discuss the Work Plans for the 2011 field season and any project updates.	Alyce Hughey
6/7/2011	Document, Report, or Work plan Review - other	Reviewed the 2010 Groundwater Monitoring Report, Tok Terminal Station, dated April 2011, from ALTA Geosciences. The May 2010 groundwater sampling event, DRO concentrations in monitoring wells MW-5, MW-6 and MW-8 showed some significant increases in DRO concentrations. An additional sampling event was conducted in June of 2010 to confirm the May sampling concentrations that showed a significant decrease in DRO concentrations within these wells. For the October 2010 sampling the concentrations again increased within these wells; however, the concentrations were not as high as the May sampling event. The fluxes in the DRO concentrations are not known at this time. No significant pattern has been observed; therefore the DRO concentration fluxes remain a mystery. A trough-like feature has also been observed in the area of MW-6 for the past few sampling events. The cause or the reason for the trough-like feature is not known at this time. The in-situ remediation system consisting of a bioventing/soil vapor extraction and bio-sparging system does appear to be sufficiently preventing off-site plume migration of the DRO plume. The unidentified drinking water well located just off-site was also sampled in 2010 with sample results of un-detected for DRO.	Alyce Hughey
4/16/2012	Document, Report, or Work plan Review - other	Reviewed the 2011 Groundwater Monitoring Report, Tok Terminal Station. The 2011 groundwater sampling events were conducted on June 16, 2011 and October 4, 2011. The DRO concentrations showed some significant decreases in concentrations in monitoring wells MW-5, MW-6, and MW-8. It appears that the installation and operation of the bioventing/soil vapor extraction and biosparging remediation system to be an effective treatment of the DRO contamination at the site. The operation of the remediation systems were during the summer months of 2011, from May until October of 2011 when it was shut off for the winter. The trough-like feature continues to exhibit in the area of MW-6. It is not known as to why, and an ongoing investigation to the cause is being investigated through a year-long water temperature investigation using a water level transducer in MW-7. The groundwater continues to flow in a west/northwesterly flow direction, with the groundwater levels lower in the spring than in the fall.	Alyce Hughey
5/18/2012	Meeting or Teleconference Held	Meeting with Paul Horwath, Alex Tula with ALTA GeoSciences and Larry Bamberger at the ADEC Soldonta office to discuss the current site conditions, remedial actions for 2012, the joinging properties and the status of relocating the drinking water well located next to the AT&T property.	Alyce Hughey
6/3/2013	Document, Report, or Work plan Review - other	The 2012 groundwater sampling events were conducted on June 14, 2012 and September 19, 2012. Wells were sampled for DRO during both sampling events, with wells MW-3, MW-5, MW-6 and MW-8 being sampled for BTEX, PAH, TOC, VPH and EPH on September 19, 2012. The DRO concentrations continue to show a decrease in concentrations in monitoring wells MW-5, MW-6, and MW-8. It appears that the installation of the bioventing/soil vapor extraction and biosparging remediation system is showing to be an effective treatment of the DRO contamination at the site. PAHs were detected in MW-5 and MW-8, but well below the ADEC groundwater cleanup levels. DRO concentrations were at 3.330 and 11.40 mg/L in MW-5 and MW-6 respectively in June of 2012, where only MW-6 detected DRO at 18.90 mg/L in September of 2012. The remediation systems were operating on a continual basis from May 3, 2012 until October of 2012 when the systems were shut down for the winter. During the June and September sampling events the groundwater showed once again a trough-like feature around Monitoring Wells MW-6. The cause is not known, and it was thought that temperature may be a contributing factor, but after a study of the groundwater temperature that started in June of 2011, the data did not support this hypothesis. Temperature rangers were only between 0.5 and 0.70C. The groundwater continues to flow in a west/northwesterly flow direction, with the groundwater levels lower in the spring than in the fall. The groundwater levels were 5.20 to 5.29 feet lower in June than in September.	Alyce Hughey
6/21/2013	Meeting or Teleconference Held	Meeting with ALTA Geosciences and ADEC staff (Paul Horwath and Alyce Hughey) to discuss the current site conditions and proposed work plans for the 2013 field season.	Alyce Hughey
4/30/2014	Document, Report, or Work plan Review - other	Reviewed the 2013 Groundwater Monitoring Report, dated April 2014, from ALTA Geosciences, Inc. The 2013 groundwater monitoring events were performed on May 29, 2013 and October 2, 2013. Wells were sampled for DRO during both sampling events, and methane was sampled for natural attenuation parameters during the October sampling. DRO concentrations were at 1.58, 6.50 and 7.6 mg/L in monitoring wells MW-3, MW-5 and MW-6 respectively in May of 2013, where DRO concentrations were at 1.93 and 19.9 mg/L in monitoring wells MW-5 and MW-6 respectively in October of 2013. Methane was detected at low concentrations, and it was concluded that the October samples for methane show that methanogens is not an important microbial degradation process in the plume. Groundwater was flowing towards the west/west-northwest with a low gradient of 0.0005 to 0.0008, with a depression centered on well MW-6. The depth to groundwater was 52.41 to 56.16 feet below ground surface in May, and 47.07 to 55.79 feet below ground surface in October of 2012. The groundwater levels were 5.33 to 5.40 feet lower in May than in October, which is consistent with historical groundwater levels with lows the end of May and highs in October. Monitoring well MW-7 has been monitored continuously from June 2011 to October 2013 using data-logging pressure transducers. An unusual rapid water level rise of approximately two feet occurred between June 1 and June 8 of 2013. The cause is not known other than a late but very rapid spring thaw that occurred in 2013.	Alyce Hughey
5/6/2014	Meeting or Teleconference Held	DEC staff Paul Horwath and Alyce Hughey met with Alex Tula, with ALTA Geosciences and Mark Smith, representing AT&T to discuss the decreasing groundwater monitoring from semi-annually to annually, with one sample to be collected from the Unidentified Well next spring before remediation system startup. Also discussed AT&T attempts to install a new drinking water well for adjacent property owner with the Unidentified Well.	Alyce Hughey
6/16/2015	Site Characterization Report Approved	Review Alta Geosciences 2014 Groundwater Monitoring Report.	Paul Horwath
9/24/2015	Document, Report, or Work plan Review - other	Reviewed, 2014 Groundwater Monitoring Report, Tok Terminal Station, dated May 2015, prepared by Alta Geosciences, Inc, in association with Kent & Sullivan, Inc. Similar trend and groundwater quality and gradient being reported as in prior GW sampling events.	Paul Horwath
4/14/2017	Document, Report, or Work plan Review - other	Review Alta Geosciences 2016 GW monitoring report. Send e-mail communication requiring BTEX and PAH analyses on the 4 impacted GW MWs during the next GW sampling event.	Paul Horwath
4/27/2018	Document, Report, or Work plan Review - other	ADEC issued a letter in response to its review of the 2017 Groundwater Monitoring Report. Next GW sampling event scheduled for the fall of 2018.	Paul Horwath
12/26/2019	Document, Report, or Work plan Review - other	Sent RP Comment letter for 2018 Groundwater Monitoring Report Tok Terminal Station, dated May 2019	Jessica Hall
1/6/2020	Document, Report, or Work plan Review - other	Received updated 2018 Groundwater Monitoring Report Tok Terminal Station, dated December 2019, Historic Groundwater Gradients memo, and Tok Terminal Station ADEC Comments Response on January 06, 2020.	Jessica Hall
1/9/2020	Update or Other Action	Received 2019 Groundwater Monitoring Report Tok Terminal Station, dated January 2020.	Jessica Hall
1/14/2020	Site Characterization Report Approved	Sent Approval letter to RP for updated 2018 Groundwater Monitoring Report Tok Terminal Station, dated December 2019.	Jessica Hall
1/31/2020	Site Characterization Report Approved	Sent Approval Letter to the RP for the 2019 Groundwater Monitoring Report Tok Terminal Station, dated January 2020. Well MW-6 had a DRO concentration of 1.72 mg/L in May and 8.48 mg/L in September. Well MW-5 had a DRO concentration of 2.23 mg/L in September. Well MW-3 had a DRO concentration of 1.68 mg/L in September. These values exceed the ADEC groundwater criteria of 1.5 mg/L. Groundwater monitoring to continue in the fall of 2020. Continuation of the suspended operation of the in-situ Bioventing/Soil Vapor Extraction System will continue in 2020. Groundwater levels will continue to be monitored in all accessible wells. Groundwater monitoring will be performed in the fall of 2020 in the same wells sampled in 2019.	Jessica Hall
2/21/2020	Document, Report, or Work plan Review - other	Sent ADEC Comment Letter on AT&T Alascom Sites QAPP.	Jessica Hall
1/28/2021	Document, Report, or Work plan Review - other	ADEC sent the RP comment letter on the 2020 Groundwater Monitoring Report Tok Terminal Station, Dated January 2021. Awaiting a submittal of the Final report.	Jessica Hall
2/9/2021	Site Characterization Report Approved	Sent RP approval letter for the Revised 2020 Groundwater Monitoring Report Tok Terminal Station, Dated January 2021, received January 29, 2021, by Alaska Department of Environmental Conservation. In September 2020, the following wells contained DRO concentrations exceeding CULs (1.5 mg/L) :MW-6: 34.5 mg/L, MW-5: 9.28 mg/L, and MW-8: 1.55 mg/L. The plume is stable and not migrating. Prior sampling events ranged as high as 121 mg/L. Groundwater levels will continue to be monitored in all accessible wells. Groundwater monitoring will be performed in the fall of 2021 in the same wells sampled in 2020. The operation of the in-situ Bioventing/Soil Vapor Extraction System in 2021 will remain suspended.	Jessica Hall
8/2/2021	Update or Other Action	Requested site update and confirmed groundwater levels will continue to be monitored in all accessible wells. Groundwater monitoring will be performed in the fall of 2021 in the same wells sampled in 2020. The operation of the in-situ Bioventing/Soil Vapor Extraction System in 2021 will remain suspended.	Jessica Hall
10/1/2021	Update or Other Action	Sent RP approval for Revised Amendment to the Field Sampling/Quality Assurance Project Plan, AT&T/Alascom Sites, dated September 27, 2021.	Jessica Hall
1/4/2022	Document, Report, or Work plan Review - other	Sent RP comments on “2021 Groundwater Monitoring Report”, dated December 2021. Requested an updated report be submitted.	Jessica Hall
6/24/2022	Site Characterization Report Approved	ADEC sent the RP an approval letter for “2021 Groundwater Monitoring Report”, dated January 2022.	Jessica Hall
8/22/2022	Update or Other Action	ADEC sent Avangrid Renewables Holdings, Inc. an approval letter for “Well Decommission Plan”, dated July 23 2022. Wells to be removed are as follows: MW-1.The well has been sampled and analyzed 26 times from 2006 through 2021 by ALTA. The well has never had any detectable DRO reported in any event. MW-4, The well has been sampled and analyzed 13 times through 2015. The well has never had any detectable DRO reported in any event and is no longer part of the groundwater monitoring program. MW-7 was sampled and analyzed 20 times 2006 through 2017. The well has never had any detectable DRO reported in any event and is no longer part of the groundwater monitoring program. MW-9 installed in 2007 and sampled and analyzed 17 times through 2017. The well has never had any detectable DRO reported in any event and is no longer part of the groundwater monitoring program. MW-10 was installed in 2007 and sampled and analyzed 17 times through 2017. The well has never had any detectable DRO reported in any event and is no longer part of the groundwater monitoring program. MW-11 was installed in 2007 and sampled and analyzed 17 times through 2017. The well has never had any detectable DRO reported in any event and is no longer part of the groundwater monitoring program. A-1 and B-1 were biosparging wells which were a part of the in-situ bioremediation system. They are screened from 78 to 83 feet bgs. They will be demobilized. The bioremediation system which, has not been operated since 2017.	Jessica Hall
4/3/2023	Document, Report, or Work plan Review - other	Comments on the 2022 Groundwater Monitoring Report Tok Terminal Station submitted March 6, 2023 were sent April 4, 2023. Requested an updated report be submitted.	Dawn Wilburn
4/14/2023	Site Characterization Report Approved	ADEC sent Approval letter to Avangrid Renewables Holdings, Inc. for “2022 Groundwater Monitoring Report”, dated April 2023. ADEC approved the conducting of groundwater monitoring in the fall of 2023. In 2022, 2 wells had DRO concentration above cleanup levels, MW-6 was 13.0 mg/L and MW-5 was 2.87 mg/L. Decommissioning of wells approved by ADEC was not completed in 2022 and will be done in 2023. The Bioventing/Soil Vapor Extraction System (BN/SVE) was decommissioned and removed from the site in 2022 as approved by ADEC.	Dawn Wilburn
7/12/2023	Document, Report, or Work plan Review - other	ADEC sent RP comments on report "Long Term Groundwater Management Plan Tok Terminal Station", dated June 2023. Requested a revised report be submitted.	Dawn Wilburn
7/17/2023	Site Characterization Report Approved	Sent RP approval letter for Cumulative Risk Calculator Report dated July 5, 2023.	Dawn Wilburn
7/28/2023	Site Characterization Workplan Approved	ADEC sent approval letter to the RP for the revised report “Long Term Groundwater Monitoring Plan Tok Terminal Station Site”, dated July 2023. Groundwater samples will be collected from monitoring wells MW-2, MW-3, MW-5, MW-6, and MW-8 for DRO analysis. In 2023, samples will also be analyzed for VOCs. A long term monitoring schedule for will be reviewed after the 2023 sampling results are received.	Dawn Wilburn
9/12/2023	Site Characterization Workplan Approved	ADEC sent approval letter to the RP for the revised report “Conceptual Site Model Tok Terminal Station Site”, dated September 2023.	Dawn Wilburn
1/4/2024	Site Characterization Report Approved	Sent RP approval for 2023 well decommissioning report. Monitoring wells MW1, MW7, MW9, MW10, MW11 were removed.	Dawn Wilburn
1/16/2024	Site Characterization Report Approved	Sent RP approval for the 2023 Groundwater Monitoring report dated January 2024. The groundwater contamination plume appears stable and to be contained within the property boundaries. Monitoring wells MW-5 and MW-6 were the only wells with exceedances of DRO (3.04 and 3.21 mg/L respectively). A three year groundwater monitoring schedule was approved by DEC. DEC also requested that the onsite well be sampled in the next round of sampling.	Dawn Wilburn
1/22/2024	Document, Report, or Work plan Review - other	ADEC sent RP comments on report "Long Term Groundwater Management Plan Tok Terminal Station", dated January 2024. Requested a revised report be submitted.	Dawn Wilburn
1/31/2024	Site Characterization Workplan Approved	Sent RP approval for the revised Long Term Groundwater Management Plan dated January 2024. Monitoring wells MW-2, MW-3, MW-5, MW-6, MW-8 and the on-site domestic well will be sampled every three years. The next sampling event will occur in 2026.	Dawn Wilburn

Action Date

Action

Description

DEC Staff

6/23/1998

Site Ranked Using the AHRM

Initial ranking by staff.

Anne Marie Palmieri

6/23/1998

Update or Other Action

Site accepted into the Voluntary Cleanup Program. Action rescinded and changed to Update on 1/29/03.

Anne Marie Palmieri

7/2/1998

Site Added to Database

DRO/RRO contaminated soil.

Anne Marie Palmieri

8/9/2000

Update or Other Action

Communication from RP: Monitoring well installation completed. Diesel may have migrated to GW. Will call back with analytical results.

David Verbrugge

2/27/2003

Update or Other Action

Responsible Party field changed based on new information from PacificCorp Environmental Remediation Company.

Elizabeth Stergiou

3/7/2005

Update or Other Action

Talked to Lott Hass (503) 813-5517 with PacifiCorp. She stated that the work that was proposed in the July 2001 workplan was completed and monitoring has occurred since that time. A report was not generated because there was no project manager assigned within ADEC. I told her that the site may qualify for a conditional closure since it appears that the groundwater levels at the site are stable or decreasing. She may want to conduct a conceptual site model at the site and include that in the report for a possible conditional closure. She did state that all the monitoring wells on the property are actively being monitored.

Deborah Williams

7/28/2005

GIS Position Updated

Using Figure 1.3 and Site Location from a Phase II site Investigation Tok Junction Terminal, from Woodward-Clyde, dated January 8, 1998, in conjunction with TopoZone Pro, entered the coordinates for this site. Metadata include USGS Topo Map 1:63K, TopoZone Pro Street Map, Black and White Aerial Photo, on a Medium Size Map, View Scale 1:25,000, Coordinate Datum NAD83. Medium to High degree of confidence in accuracy of location.

Alyce Hughey

8/1/2005

Update or Other Action

Sent e-mail to PacifiCorp requesting project status update and copies of submittals subsequent to the Investigation Work Plan July 2001. Soil and GW contamination exceeding ADEC clenaup levels exists at the site.

Donald Seagren

12/16/2005

Update or Other Action

Received no response to August 05 e-mail requesting project status update. Sent another request for update and/or submission of work plans leading to site closure in 2006.

Donald Seagren

12/23/2005

Update or Other Action

Received a response from John Aniello, new PERCO project manager. Sent him a brief summary of outstanding issues remaining to complete assessment & cleanup to reach site closure. Requested work plan be submitted for work during the 06 field season.

Donald Seagren

8/21/2006

Update or Other Action

Reviewed 06 monitoring report. GW occurs at a depth of 55', very low gradient of ~0.001ft/ft; apparent flor to west (parallel to the Tanana river). DRO is the principal contaminant. Other constituents below cleaup levels. Soil contamination appears to go to GW. Aerobic & sulfate-reducing microbes are active in the plume and have significanlty degraded the gw DRO contamination. Additional MWs will be installed to further delineate the contaminant plume prior to developing a CAP. downgradient receptors will be defined as part of the additional study.

Donald Seagren

8/25/2006

Cleanup Plan Approved

Reviewed and approved Interim Soil Cleanup plan

Donald Seagren

8/25/2006

Site Characterization Workplan Approved

Approved GW investigation work plan. Required the RRO analysis for the initial sampling event. If data shows that it is not a concern, RRO will be dropped from future analysis.

Donald Seagren

9/22/2006

Update or Other Action

Approved transport of 600 tons of petroleum contaminated soil to OIT in Fairbanks for thermal rmediation.

Donald Seagren

1/5/2007

Update or Other Action

Reviewed 06 Site Investigation Report. there are 2 distinct contaminant plumes resulting from releases at the I & J tanks. Soil and GW at both areas exceeds ADEC cleanup levels. The J tank plume is delineated in all directions and does not extend beyond the facility property lines. The I tank plume appears to extend beyond the site's west property line. The downgradient plume extent is not delineated and the upgradient GW quality is not characterized. Biodegradation of the plumes is occurring as a result of aerobic respiration, denitrification and possibly sulfate reduction processes. The aquifer assimilative capacity is less than the reported DRO (primary contaminant of concern) concentrations in source area GW, suggesting that natural attenuation is not sufficient to control plume migration. Further monitoring and assessment will be conducted in 2007 to fill in data gaps and better understand the site in order to develop a corrective action plan.

Donald Seagren

2/8/2007

Site Characterization Report Approved

Reviewed the Release & Cleanup final report for the 10 gallon weathered diesel fuel release from the old CANOL Pipeline. The release occurred during removal of sections of the pipeline during site assessment and remediation activities during the summer of 06. The contaminated soil was excavated to belwo migratino to Gw cleanup levels. The contaminated soils was shippe dto OIT in Fairbanks for thermal rmediation. AT&T was informed that no further remedial or invesigative actions are required for this rlease. the Department considers it closed. This closure determination is for the 10 gallon CANOL Pipeline release only. It does not apply to the remainder of the site.

Donald Seagren

4/9/2007

Exposure Tracking Model Ranking

Donald Seagren

5/1/2007

Update or Other Action

Reviewed Construction Completion Report 2006 Interim Cleanup Plan - Soil dated March 07. DRO is remaining contaminant of concern. Two areas AOI-J and AOI-I have DRO soil contamination remaining at depths below 8 to 9 feet that exceeds ADEC cleanup levels of 250 mg/kg. All contaminated soil exceeding ADEC cleanup levels has been excavated given the constraints of equipment and not damaging buildings. the contamianted soils was taken to OIT in Fairbanks for htermal remediation. Further monitoring and assessment work is being planned.

Donald Seagren

7/5/2007

Site Characterization Workplan Approved

Reviewed and approved work plan for installation of 3 additioanl monitor wells and 2 rounds of GW monitroing

Donald Seagren

2/13/2008

Site Characterization Report Approved

Reviewed 2007 Well Installation Report, dated February 08 by ALTA Geosciences, Inc. GW sampling results will be included in a separate report. One soil sample collected at the GW level in each new well. In 2 wells the samples were non-detect for DRO. Results from soil sample @ 53'bgs from boring MW-10 (adjacent ot Center Street) indicated DRO concentration @ 50.5 mg/kg, which is below ADEC cleanup levels.

Donald Seagren

4/1/2008

Update or Other Action

Two monitoring events were preformed in July & October 07. the 07 DRO concentrations in the I-tank and J-tanks source areas have decreased significantly since 06: from 18,900 ug/l to 2,700 ug/l Dro and from 39,000 usg/l to 9,840 ug/l DRO respectively. The extent of the plumes have also decreased such that they no longer appear to extend off site and appear to be largely constrained to the source areas. The 06 soil remediation coupled with aerobic respiration appear to be the principal processes responsible for the decline in the groundwater DRO plumes. Monitroing will continue in 08. Only MW 5 & 6 contained DRO concentrations above the ADEC cleanup levels.

Donald Seagren

6/12/2008

Update or Other Action

Site transferred from Don Seagren to Paul Horwath per Linda Nuechterlein.

Alyce Hughey

1/21/2009

Exposure Tracking Model Ranking

A new updated ranking with ETM has been completed for source area 73921 ast.

Alyce Hughey

4/22/2010

Document, Report, or Work plan Review - other

Reviewed the 2009 Groundwater Monitoring Report, dated February 2010, from ALTA Geosciences, Inc. for Paul Horwath. The groundwater concentrations have reduced significantly since the 2008 sampling events. DRO concentrations exceeding the groundwater cleanup levels remains within two of the monitoring wells during the 2009 sampling events. The newly installed drinking water well located approximately 20 feet northwest of MW-3 did not detect DRO. The purpose of the unidentified well is not known at this time. ADEC has requested additional information regarding the owner’s name, address, contact information, the current or future intention of this water well, and notify the owner of the presence of the petroleum contaminated groundwater plume originating at the Tok Terminal Station site. A bioventing/soil vapor extraction and bio-sparging system was installed between July and October of 2009. The system was initiated in September 2009 and continued until late October 2009 when the system was shut down for the winter. The system is planned on being restarted in the spring of 2010.

Alyce Hughey

5/11/2010

Meeting or Teleconference Held

Meeting with AT&T Inc., ALTA Geosciences and ADEC staff (Paul Horwath and Alyce Hughey) to discuss the Work Plans for the 2010 field season and any project updates.

Alyce Hughey

5/11/2011

Meeting or Teleconference Held

Meeting with AT&T Inc., ALTA Geosciences, Iberdrola Renewables Holdings, Inc. and ADEC staff (Paul Horwath and Alyce Hughey) to discuss the Work Plans for the 2011 field season and any project updates.

Alyce Hughey

6/7/2011

Document, Report, or Work plan Review - other

Reviewed the 2010 Groundwater Monitoring Report, Tok Terminal Station, dated April 2011, from ALTA Geosciences. The May 2010 groundwater sampling event, DRO concentrations in monitoring wells MW-5, MW-6 and MW-8 showed some significant increases in DRO concentrations. An additional sampling event was conducted in June of 2010 to confirm the May sampling concentrations that showed a significant decrease in DRO concentrations within these wells. For the October 2010 sampling the concentrations again increased within these wells; however, the concentrations were not as high as the May sampling event. The fluxes in the DRO concentrations are not known at this time. No significant pattern has been observed; therefore the DRO concentration fluxes remain a mystery. A trough-like feature has also been observed in the area of MW-6 for the past few sampling events. The cause or the reason for the trough-like feature is not known at this time. The in-situ remediation system consisting of a bioventing/soil vapor extraction and bio-sparging system does appear to be sufficiently preventing off-site plume migration of the DRO plume. The unidentified drinking water well located just off-site was also sampled in 2010 with sample results of un-detected for DRO.

Alyce Hughey

4/16/2012

Document, Report, or Work plan Review - other

Reviewed the 2011 Groundwater Monitoring Report, Tok Terminal Station. The 2011 groundwater sampling events were conducted on June 16, 2011 and October 4, 2011. The DRO concentrations showed some significant decreases in concentrations in monitoring wells MW-5, MW-6, and MW-8. It appears that the installation and operation of the bioventing/soil vapor extraction and biosparging remediation system to be an effective treatment of the DRO contamination at the site. The operation of the remediation systems were during the summer months of 2011, from May until October of 2011 when it was shut off for the winter. The trough-like feature continues to exhibit in the area of MW-6. It is not known as to why, and an ongoing investigation to the cause is being investigated through a year-long water temperature investigation using a water level transducer in MW-7. The groundwater continues to flow in a west/northwesterly flow direction, with the groundwater levels lower in the spring than in the fall.

Alyce Hughey

5/18/2012

Meeting or Teleconference Held

Meeting with Paul Horwath, Alex Tula with ALTA GeoSciences and Larry Bamberger at the ADEC Soldonta office to discuss the current site conditions, remedial actions for 2012, the joinging properties and the status of relocating the drinking water well located next to the AT&T property.

Alyce Hughey

6/3/2013

Document, Report, or Work plan Review - other

The 2012 groundwater sampling events were conducted on June 14, 2012 and September 19, 2012. Wells were sampled for DRO during both sampling events, with wells MW-3, MW-5, MW-6 and MW-8 being sampled for BTEX, PAH, TOC, VPH and EPH on September 19, 2012. The DRO concentrations continue to show a decrease in concentrations in monitoring wells MW-5, MW-6, and MW-8. It appears that the installation of the bioventing/soil vapor extraction and biosparging remediation system is showing to be an effective treatment of the DRO contamination at the site. PAHs were detected in MW-5 and MW-8, but well below the ADEC groundwater cleanup levels. DRO concentrations were at 3.330 and 11.40 mg/L in MW-5 and MW-6 respectively in June of 2012, where only MW-6 detected DRO at 18.90 mg/L in September of 2012. The remediation systems were operating on a continual basis from May 3, 2012 until October of 2012 when the systems were shut down for the winter. During the June and September sampling events the groundwater showed once again a trough-like feature around Monitoring Wells MW-6. The cause is not known, and it was thought that temperature may be a contributing factor, but after a study of the groundwater temperature that started in June of 2011, the data did not support this hypothesis. Temperature rangers were only between 0.5 and 0.70C. The groundwater continues to flow in a west/northwesterly flow direction, with the groundwater levels lower in the spring than in the fall. The groundwater levels were 5.20 to 5.29 feet lower in June than in September.

Alyce Hughey

6/21/2013

Meeting or Teleconference Held

Meeting with ALTA Geosciences and ADEC staff (Paul Horwath and Alyce Hughey) to discuss the current site conditions and proposed work plans for the 2013 field season.

Alyce Hughey

4/30/2014

Document, Report, or Work plan Review - other

Reviewed the 2013 Groundwater Monitoring Report, dated April 2014, from ALTA Geosciences, Inc. The 2013 groundwater monitoring events were performed on May 29, 2013 and October 2, 2013. Wells were sampled for DRO during both sampling events, and methane was sampled for natural attenuation parameters during the October sampling. DRO concentrations were at 1.58, 6.50 and 7.6 mg/L in monitoring wells MW-3, MW-5 and MW-6 respectively in May of 2013, where DRO concentrations were at 1.93 and 19.9 mg/L in monitoring wells MW-5 and MW-6 respectively in October of 2013. Methane was detected at low concentrations, and it was concluded that the October samples for methane show that methanogens is not an important microbial degradation process in the plume. Groundwater was flowing towards the west/west-northwest with a low gradient of 0.0005 to 0.0008, with a depression centered on well MW-6. The depth to groundwater was 52.41 to 56.16 feet below ground surface in May, and 47.07 to 55.79 feet below ground surface in October of 2012. The groundwater levels were 5.33 to 5.40 feet lower in May than in October, which is consistent with historical groundwater levels with lows the end of May and highs in October. Monitoring well MW-7 has been monitored continuously from June 2011 to October 2013 using data-logging pressure transducers. An unusual rapid water level rise of approximately two feet occurred between June 1 and June 8 of 2013. The cause is not known other than a late but very rapid spring thaw that occurred in 2013.

Alyce Hughey

5/6/2014

Meeting or Teleconference Held

DEC staff Paul Horwath and Alyce Hughey met with Alex Tula, with ALTA Geosciences and Mark Smith, representing AT&T to discuss the decreasing groundwater monitoring from semi-annually to annually, with one sample to be collected from the Unidentified Well next spring before remediation system startup. Also discussed AT&T attempts to install a new drinking water well for adjacent property owner with the Unidentified Well.

Alyce Hughey

6/16/2015

Site Characterization Report Approved

Review Alta Geosciences 2014 Groundwater Monitoring Report.

Paul Horwath

9/24/2015

Document, Report, or Work plan Review - other

Reviewed, 2014 Groundwater Monitoring Report, Tok Terminal Station, dated May 2015, prepared by Alta Geosciences, Inc, in association with Kent & Sullivan, Inc. Similar trend and groundwater quality and gradient being reported as in prior GW sampling events.

Paul Horwath

4/14/2017

Document, Report, or Work plan Review - other

Review Alta Geosciences 2016 GW monitoring report. Send e-mail communication requiring BTEX and PAH analyses on the 4 impacted GW MWs during the next GW sampling event.

Paul Horwath

4/27/2018

Document, Report, or Work plan Review - other

ADEC issued a letter in response to its review of the 2017 Groundwater Monitoring Report. Next GW sampling event scheduled for the fall of 2018.

Paul Horwath

12/26/2019

Document, Report, or Work plan Review - other

Sent RP Comment letter for 2018 Groundwater Monitoring Report Tok Terminal Station, dated May 2019

Jessica Hall

1/6/2020

Document, Report, or Work plan Review - other

Received updated 2018 Groundwater Monitoring Report Tok Terminal Station, dated December 2019, Historic Groundwater Gradients memo, and Tok Terminal Station ADEC Comments Response on January 06, 2020.

Jessica Hall

1/9/2020

Update or Other Action

Received 2019 Groundwater Monitoring Report Tok Terminal Station, dated January 2020.

Jessica Hall

1/14/2020

Site Characterization Report Approved

Sent Approval letter to RP for updated 2018 Groundwater Monitoring Report Tok Terminal Station, dated December 2019.

Jessica Hall

1/31/2020

Site Characterization Report Approved

Sent Approval Letter to the RP for the 2019 Groundwater Monitoring Report Tok Terminal Station, dated January 2020. Well MW-6 had a DRO concentration of 1.72 mg/L in May and 8.48 mg/L in September. Well MW-5 had a DRO concentration of 2.23 mg/L in September. Well MW-3 had a DRO concentration of 1.68 mg/L in September. These values exceed the ADEC groundwater criteria of 1.5 mg/L. Groundwater monitoring to continue in the fall of 2020. Continuation of the suspended operation of the in-situ Bioventing/Soil Vapor Extraction System will continue in 2020. Groundwater levels will continue to be monitored in all accessible wells. Groundwater monitoring will be performed in the fall of 2020 in the same wells sampled in 2019.

Jessica Hall

2/21/2020

Document, Report, or Work plan Review - other

Sent ADEC Comment Letter on AT&T Alascom Sites QAPP.

Jessica Hall

1/28/2021

Document, Report, or Work plan Review - other

ADEC sent the RP comment letter on the 2020 Groundwater Monitoring Report Tok Terminal Station, Dated January 2021. Awaiting a submittal of the Final report.

Jessica Hall

2/9/2021

Site Characterization Report Approved

Sent RP approval letter for the Revised 2020 Groundwater Monitoring Report Tok Terminal Station, Dated January 2021, received January 29, 2021, by Alaska Department of Environmental Conservation. In September 2020, the following wells contained DRO concentrations exceeding CULs (1.5 mg/L) :MW-6: 34.5 mg/L, MW-5: 9.28 mg/L, and MW-8: 1.55 mg/L. The plume is stable and not migrating. Prior sampling events ranged as high as 121 mg/L. Groundwater levels will continue to be monitored in all accessible wells. Groundwater monitoring will be performed in the fall of 2021 in the same wells sampled in 2020. The operation of the in-situ Bioventing/Soil Vapor Extraction System in 2021 will remain suspended.

Jessica Hall

8/2/2021

Update or Other Action

Requested site update and confirmed groundwater levels will continue to be monitored in all accessible wells. Groundwater monitoring will be performed in the fall of 2021 in the same wells sampled in 2020. The operation of the in-situ Bioventing/Soil Vapor Extraction System in 2021 will remain suspended.

Jessica Hall

10/1/2021

Update or Other Action

Sent RP approval for Revised Amendment to the Field Sampling/Quality Assurance Project Plan, AT&T/Alascom Sites, dated September 27, 2021.

Jessica Hall

1/4/2022

Document, Report, or Work plan Review - other

Sent RP comments on “2021 Groundwater Monitoring Report”, dated December 2021. Requested an updated report be submitted.

Jessica Hall

6/24/2022

Site Characterization Report Approved

ADEC sent the RP an approval letter for “2021 Groundwater Monitoring Report”, dated January 2022.

Jessica Hall

8/22/2022

Update or Other Action

ADEC sent Avangrid Renewables Holdings, Inc. an approval letter for “Well Decommission Plan”, dated July 23 2022. Wells to be removed are as follows: MW-1.The well has been sampled and analyzed 26 times from 2006 through 2021 by ALTA. The well has never had any detectable DRO reported in any event. MW-4, The well has been sampled and analyzed 13 times through 2015. The well has never had any detectable DRO reported in any event and is no longer part of the groundwater monitoring program. MW-7 was sampled and analyzed 20 times 2006 through 2017. The well has never had any detectable DRO reported in any event and is no longer part of the groundwater monitoring program. MW-9 installed in 2007 and sampled and analyzed 17 times through 2017. The well has never had any detectable DRO reported in any event and is no longer part of the groundwater monitoring program. MW-10 was installed in 2007 and sampled and analyzed 17 times through 2017. The well has never had any detectable DRO reported in any event and is no longer part of the groundwater monitoring program. MW-11 was installed in 2007 and sampled and analyzed 17 times through 2017. The well has never had any detectable DRO reported in any event and is no longer part of the groundwater monitoring program. A-1 and B-1 were biosparging wells which were a part of the in-situ bioremediation system. They are screened from 78 to 83 feet bgs. They will be demobilized. The bioremediation system which, has not been operated since 2017.

Jessica Hall

4/3/2023

Document, Report, or Work plan Review - other

Comments on the 2022 Groundwater Monitoring Report Tok Terminal Station submitted March 6, 2023 were sent April 4, 2023. Requested an updated report be submitted.

Dawn Wilburn

4/14/2023

Site Characterization Report Approved

ADEC sent Approval letter to Avangrid Renewables Holdings, Inc. for “2022 Groundwater Monitoring Report”, dated April 2023. ADEC approved the conducting of groundwater monitoring in the fall of 2023. In 2022, 2 wells had DRO concentration above cleanup levels, MW-6 was 13.0 mg/L and MW-5 was 2.87 mg/L. Decommissioning of wells approved by ADEC was not completed in 2022 and will be done in 2023. The Bioventing/Soil Vapor Extraction System (BN/SVE) was decommissioned and removed from the site in 2022 as approved by ADEC.

Dawn Wilburn

7/12/2023

Document, Report, or Work plan Review - other

ADEC sent RP comments on report "Long Term Groundwater Management Plan Tok Terminal Station", dated June 2023. Requested a revised report be submitted.

Dawn Wilburn

7/17/2023

Site Characterization Report Approved

Sent RP approval letter for Cumulative Risk Calculator Report dated July 5, 2023.

Dawn Wilburn

7/28/2023

Site Characterization Workplan Approved

ADEC sent approval letter to the RP for the revised report “Long Term Groundwater Monitoring Plan Tok Terminal Station Site”, dated July 2023. Groundwater samples will be collected from monitoring wells MW-2, MW-3, MW-5, MW-6, and MW-8 for DRO analysis. In 2023, samples will also be analyzed for VOCs. A long term monitoring schedule for will be reviewed after the 2023 sampling results are received.

Dawn Wilburn

9/12/2023

Site Characterization Workplan Approved

ADEC sent approval letter to the RP for the revised report “Conceptual Site Model Tok Terminal Station Site”, dated September 2023.

Dawn Wilburn

1/4/2024

Site Characterization Report Approved

Sent RP approval for 2023 well decommissioning report. Monitoring wells MW1, MW7, MW9, MW10, MW11 were removed.

Dawn Wilburn

1/16/2024

Site Characterization Report Approved

Sent RP approval for the 2023 Groundwater Monitoring report dated January 2024. The groundwater contamination plume appears stable and to be contained within the property boundaries. Monitoring wells MW-5 and MW-6 were the only wells with exceedances of DRO (3.04 and 3.21 mg/L respectively). A three year groundwater monitoring schedule was approved by DEC. DEC also requested that the onsite well be sampled in the next round of sampling.

Dawn Wilburn

1/22/2024

Document, Report, or Work plan Review - other

ADEC sent RP comments on report "Long Term Groundwater Management Plan Tok Terminal Station", dated January 2024. Requested a revised report be submitted.

Dawn Wilburn

1/31/2024

Site Characterization Workplan Approved

Sent RP approval for the revised Long Term Groundwater Management Plan dated January 2024. Monitoring wells MW-2, MW-3, MW-5, MW-6, MW-8 and the on-site domestic well will be sampled every three years. The next sampling event will occur in 2026.

Dawn Wilburn

Contaminant Information

Name

Level Description

Media

Comments

Control Type

Type

Details

Requirements

Description

Details

“2021 Groundwater Monitoring Report”, dated January 2022

No associated sites were found.

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Site Report: AT&T Alascom Tok Terminal Station

Site Chronology

IC / Closure Details

Documents

Associated Sites

Problems/Comments

Action Information

Contaminant Information

Control Type

Requirements

“2021 Groundwater Monitoring Report”, dated January 2022

Missing Location Data

State of Alaska Department of Environmental Conservation