| Action Date |
Action |
Description |
DEC Staff |
| 7/5/2002 |
Update or Other Action |
Preliminary Assessment Results received from ARC Inc. (Calgary, Alberta). The assessment identified over 4800 cubic yards of stockpiled tailings with lead levels up to 10,400 ppm and arsenic levels up to 3,910 ppm. |
Deborah Williams |
| 7/12/2002 |
Site Added to Database |
Metals contamination. |
Deborah Williams |
| 7/15/2002 |
Site Ranked Using the AHRM |
Preliminary Ranking. |
Deborah Williams |
| 8/1/2002 |
Update or Other Action |
Letter of State Interest issued to Husky Energy Attention Sher Follett. |
Deborah Williams |
| 8/1/2002 |
Update or Other Action |
Workplan received regarding Waste characterization work for the Bevill Amendment Exclusion (EPA) and Public Health Assessment for airborne lead and arsenic. Work plan to be conducted the week of August 19th. |
Deborah Williams |
| 8/29/2002 |
Update or Other Action |
Preliminary surface soil assessment of soil on-site was received. The levels of contaminants, using the X-Ray Fluorescence (XRF), were as follows:
Mercury - background 187 - 1050 ppm; roadway nearest the residence 412 - 462 ppm.
Lead: background 132 - 140 ppm; roadway 149 - 319 ppm.
Arsenic: background 217 - 284 ppm; roadway 265 - 292 ppm.
Based on the results of this sampling, ADEC required for the consultant to take offsite surface soil samples stepping off the site in both the north and south directions. |
Deborah Williams |
| 9/30/2002 |
Update or Other Action |
Preliminary surface soil assessment of soil off-site was received. Due to the higher background levels from the earlier sampling, additional background sampling was conducted to find true background. The sampling results, using the X-Ray Fluorescence (XRF), were the following:
Near the residence (NE of property):
Lead: 39 - 261 ppm
Arsenic: 38 - 693 ppm
Mercury: 22 - 660 ppm
Background across Old Steese (near a residence):
Lead: 50 - 478 ppm
Arsenic: 87 - 419 ppm
Mercury: 48 - 1489 ppm
Background (approximately 100 m to the south of the property (vacant lot)):
Lead: 49 - 66 ppm
Arsenic: 50 - 67 ppm
Mercury: 31 - 41 ppm |
Deborah Williams |
| 10/15/2002 |
Update or Other Action |
Received a telephone call from Jeff Powers (consultant). He stated that there are some problems with using the XRF field screening instrument to detect mercury values. It appears that the mercury levels detected with the XRF are incorrect. The mercury levels are a lot lower at the site and off-site than originally thought. Further investigation is being conducted by the consultant. |
Deborah Williams |
| 11/21/2002 |
GIS Position Updated |
Existing latitude and longitude values' accuracy corroborated by digitized plat map coordinates (64.956830,-147.623254) supplied by Mike Crotteau of the Wellhead Protection Program. Existing data not modified. |
Former Staff |
| 7/20/2003 |
Update or Other Action |
ARC conducted background soil sampling at the site. 30 XRF soil samples were collected with 10 of those being sent to the laboratory for analyses. All samples were analyzed for metals. |
Deborah Williams |
| 8/1/2003 |
Site Characterization Workplan Approved |
Site characterization workplan approved for site work planned for the week of August 4th. Soil delineation, groundwater monitoring wells installation and sampling, surface water sampling and residential drinking water well sampling will be included in the sampling event. |
Deborah Williams |
| 8/20/2004 |
Site Characterization Report Approved |
ADEC approved of the May 2004 Site Assessment Report for the Fox Mill site. Further groundwater delineation is needed downgradient of MW-7, but generally, at this time, the soil and groundwater has been adequately characterized. |
Deborah Williams |
| 8/20/2004 |
Cleanup Level(s) Approved |
The proposed cleanup levels for the site are under 40"zone, migration to groundwater levels except the alternative cleanup level for arsenic which is 31 parts per million. |
Deborah Williams |
| 8/30/2004 |
Update or Other Action |
ADEC reviewed the Site Assessment report for the Former Mohawk Fox Mill site. Surface and subsurface heavy metal contamination levels were the following: antimony - up to 4300 ppm, arsenic - up to 11,000 ppm, lead - up to 11,000 ppm, silver - up to 60 ppm and cadmium - up to 70 ppm. Some groundwater contamination existed on-site with levels up to 0.42 mg/L for antimony and 0.52 mg/L of arsenic. Lead levels in the groundwater were not analyzed for and the next sampling will include lead analyses. A total volume of 34,600 cubic yards of heavy metals contaminated soil exist at the site. Of that material 7,900 cubic yards is contained within the former tailings pond, 16,900 cubic yards is within the remainder of the fenced portion of the property, 7,900 cubic yards is present on a parcel of land adjacent west/northwest boundary of the property and 1,900 cubic yards is located in the southeast area of the property containing the drive access into the property. Concentrations of antimony and lead above the ingestion level are present on site and off site in areas adjacent to the property. |
Deborah Williams |
| 9/10/2004 |
Update or Other Action |
ADEC approved of 2004 work plan for the Fox Mill Processing facility that involves the consolidation of the off-site surface contaminated soil on to the on-site property. Confirmation soil samples will be collected after the surface soils have been removed. Additional monitoring wells (3) will be installed and sampled to help delineate the downgradient extent of the groundwater contamination. An extension of the fence will be added to the northeastern portion of the site to completely secure the property. |
Deborah Williams |
| 8/10/2005 |
GIS Position Updated |
Site location confirmed correct by the project manager. Checked using FNSB tax parcels maps. Updated metadata accordingly. |
Torsten Ernst |
| 8/15/2007 |
Update or Other Action |
DEC field visit to the site to meet with consultant (Jeff Powers) for Husky Oil. a layer of soil (light colored - fine grained particles possibly remnant of historic dredging operation) was identified at varying depths and at property boundaries and beneath liner. initail field screening identified elevated metals concentrations and Mr Powers requested guidance on the need to excavate and remove or assume it was historic contamination. it appeared to be a band or swath of concentrated material across the site / area. my recommendation was to leave it in place - recognizing it would be covered with 4 - 6 feet of fill material following the cleanup activities. |
Jim Frechione |
| 4/2/2008 |
Update or Other Action |
DEC was contacted by Jeff Powers (consultant for Husky Oil) on the current status of the former Fox Mill site. Mr Powers indicated the current plan is to demolish the remaining structures and remove any remaining contaminated soil. The plan would be to transport the soil to Ft Knox gold mine for processing in their ore process plant. It was estimated that 2200 tons of soil may remain on site - versus the 22,000 tons already removed. There may be an issue with Ft Knox agreeing to the additional soil based on economics and recognition (by DEC) of their cooperative spirit. DEC may need to issue Ft Knox some recognition notice before they agreee to accept the soil. |
Jim Frechione |
| 5/22/2008 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed. |
Jim Frechione |
| 6/26/2008 |
Update or Other Action |
DEC commissioner Larry Hartig sends letter to Fort Knox acknowledging their cooperative spirit in accepting the soil from the Fox Mill site. hopefully this recognition will facilitate the transport and processing of the remaiining soil at the Fox site - estimated 2200 tons. |
Jim Frechione |
| 4/14/2010 |
Update or Other Action |
File transferred to Anchorage office. |
Ann Farris |
| 4/26/2010 |
Final Cleanup Report Reviewed |
Reviewed Site Closure Report, Former Mohawk Fox Mill dated August 31, 2009. The primary contaminants of concern are arsenic, antimony, and lead in soil and arsenic and antimony in groundwater from processed ore and mine tailings left at the site. Remedial work was conducted in 2007 and 2008 to remove the contaminant source areas and evaluate trends in groundwater contamination. Approximately 16,000 cubic yards of tailings remained on site including 5,000 cy in the former tailing pond, 6,000 cy in piles within the property boundary, and 5,000 cy stockpiled on the property southwest of the site. Remediation at the site was conducted after the site qualified for a Beville Exclusion from EPA, stating that the tailings left over from the ore beneficiation process were RCRA exempt, and Fort Knox Mine in Fairbanks agreed to accept the tailings for reprocessing and disposal in accordance with Fort Knox permits. From 2003 to 2005 as EPA was reviewing the request for a Beville Exemption, the following activities were conducted at the site: Debris including drums, tanks, building materials, and discarded equipment was collected and disposed of or recycled and the offsite stockpile southwest of the property was relocated to the tailings pond. Ore stockpiles were consolidated on site and brush was cut to facilitate removal of ore and tailings. In 2008, a background study was conducted using multi-incremental sampling at three locations near the facility. Based on historical air photos, the entire area surrounding the site was built on top of mine tailings produced by gold dredging in Goldstream Creek in the early to mid 20th century. The background arsenic concentration was determined to be 242 mg/kg.
Stockpiled ore and tailings totaling over 22,000 tons were removed from the facility in 2007 and transported to Fort Knox Mine for processing and disposal. During excavation of the tailings pond, a light colored layer was encountered approximately two feet bgs that extended along the southwestern area of the property to the property boundary. Because the material appeared to extend beyond the property boundary, it was not included in the material cleaned up and is likely a remnant of previous mining activities in the area. In June 2008, the former processing building was demolished and impacted areas beneath the former building were addressed. After removal activities were complete, the site was divided into seven decision units which were sampled using the multi incremental sampling methodology outlined in DEC guidance. Metals including antimony, arsenic, and chromium were detected above Method Two migration to groundwater cleanup levels, but below the approved background concentrations. After sampling was complete, clean backfill material consisting of mine tailings from a nearby source was placed into the excavated areas, and the site was regraded. Samples collected along the southern property line from the light colored layer two feet bgs contained arsenic and lead at concentrations above both background and Method Two migration to groundwater cleanup levels, however because this material was not associated with this specific site, further investigation and cleanup of this layer was not required.
Groundwater sampling was conducted most recently in 2008. Antimony and arsenic were detected above groundwater cleanup levels, with antimony detected up to 0.164 mg/l in well MW7 and arsenic detected up to 0.798 mg/l, also in MW7. In the 8 wells sampled in 2008, antimony was detected above the cleanup level in 1 of the samples and arsenic was detected above the cleanup level in 4 samples.
|
Bill O'Connell |
| 5/25/2010 |
Meeting or Teleconference Held |
Meeting today with Hobbit Environmental and Husky Oil. Biannual groundwater monitoring is proposed for the near term and a work plan detailing the proposed sampling will be submitted to DEC for review |
Bill O'Connell |
| 7/14/2011 |
Document, Report, or Work plan Review - other |
Reviewed 2009-2010 Groundwater monitoring Report for Former Mohawk Mill Facility. All eight wells were sampled in October 2009, six of eight monitoring wells were sampled in May 2010 (MW2 and MW3 were frozen) and all eight wells were sampled in October 2010. Sample results indicate groundwater is contaminated with arsenic and antimony at concentrations above Table C cleanup levels with arsenic detected up to 0.912 mg/l in MW7 and antimony detected up to 0.0564 mg/l in the same well. |
Bill O'Connell |
| 8/31/2011 |
Meeting or Teleconference Held |
Teleconference today with Husky Oil and Hobbit Environmental. Topics included delineation of the groundwater plume off site, re-location of wells from off site to on site, replacement of MW-1, potential future institutional controls, current and future land use, and a brief discussion of background concentrations |
Bill O'Connell |
| 4/16/2012 |
Document, Report, or Work plan Review - other |
Reviewed work plan for monitoring well installation and decommissioning at the Former Mohawk Custom Processing Mill (Fox Mill). One well will be installed to replace MW1, which was destroyed during previous remedial action. Wells MW6 and MW7 will be decommissioned, then reinstalled within the property boundary to allow for easier access. Two new wells will be installed downgradient of the source area in an effort to delineate the extent of metals impacts to groundwater. Following installation of the new wells, all the wells at the site will be sampled. |
Bill O'Connell |
| 9/18/2012 |
Site Visit |
Site visit today |
Bill O'Connell |
| 7/3/2013 |
Update or Other Action |
Received 2012 groundwater monitoring report from Hobbit Environmental. Destroyed well MW1 was replaced with MW1-12. MW6 and MW7 were decommissioned and replaced with MW6-12 and MW7-12, which are now located on the site property. Downgradient wells MW10 and MW11 were installed in the DOT right of way south of the site. |
Janice Wiegers |
| 7/3/2013 |
Update or Other Action |
Received 2012 groundwater monitoring report from Hobbit Environmental. Destroyed well MW1 was replaced with MW1-12. MW6 and MW7 were decommissioned and replaced with MW6-12 and MW7-12, which are now located on the site property. Downgradient wells MW10 and MW11 were installed in the DOT right of way south of the site. |
Janice Wiegers |
| 3/10/2014 |
Update or Other Action |
File transferred to FBX office |
Annie Ariel |
| 5/27/2014 |
Document, Report, or Work plan Review - other |
Received 2013 Groundwater Monitoring and Sampling Results report from Hobbit Environmental. |
Janice Wiegers |
| 2/27/2015 |
Document, Report, or Work plan Review - other |
2014 Groundwater Monitoring and Sampling Results submitted by Hobbit Environmental. |
Janice Wiegers |
| 5/1/2015 |
Site Visit |
DEC staff met Jeff Powers of Hobbit Environmental Consulting at the site location to discuss ongoing groundwater monitoring. During the site visit, the neighbor discussed the fence installed around the former Fox Mill. According to the neighbor, the northern fence line may be located on his property. |
Janice Wiegers |
| 5/15/2015 |
Update or Other Action |
Met with Jeff Powers of Hobbit Environmental to discuss groundwater monitoring data and development of a long-term monitoring plan and possible closure approach. |
Janice Wiegers |
| 7/21/2015 |
Site Characterization Workplan Approved |
Workplan submitted for additional groundwater characterization, including 1)installation of off-site monitoring wells to evaluate background conditions, 2) characterization of buried material along western boundary line, 3) groundwater sampling in area of buried waste at northeast corner of property, and 4) ecoscoping evaluation. DEC reviewed workplan and requested additional information regarding the groundwater sampling methods and a survey of groundwater use on adjacent properties. DEC approved workplan on 8/27/15. |
Janice Wiegers |
| 5/26/2016 |
Document, Report, or Work plan Review - other |
Summary of 2015 quarterly monitoring results submitted for June, September and December. Groundwater flow across the site was to the south in June and south-southwest in both September and December. Monitoring wells MW12-15, MW13-15, and MW14-15 were installed in the DOT right-of-way east of the site as background sampling locations and sampled twice. BW15-15 was also installed in the area of buried domestic waste in the northeast portion of the site. Samples were collected from BW15-15 and analyzed for metals, petroleum, VOCs, SVOCs, PCBs, pesticides, and herbicides; no constituents other than metals were detected. During drilling, dredge tailings were encountered down to 6 to 10 feet and were underlain by coarse sand with some fine and very fine sand. In 2015, potential sampling error was also investigated by analyzing duplicates, split samples for total and dissolved metals, and comparing the use of bailers to low flow sampling techniques. |
Janice Wiegers |
| 5/12/2017 |
Document, Report, or Work plan Review - other |
Hobbit Environmental submitted document titled "Strategy to Achieve Conditional Site Closure". The document describes additional tasks for completion prior to conditional closure. The tasks include 1) establishing background concentrations for groundwater, 2) complete horizontal and vertical delineation of groundwater impacts, 3) complete water use survey near site, 4) complete assessment and possible cleanup of metal-impacted soil at the western property boundary that may extend onto the adjacent property, and 5) develop institutional controls for the site. A schedule was proposed for 2017. |
Janice Wiegers |
| 5/16/2017 |
Document, Report, or Work plan Review - other |
Hobbit Environmental submitted document titled "Method to Establish Background Concentrations in Shallow Groundwater". The document describes the current groundwater sampling data, estimates possible background levels in groundwater, and proposes an approach to establishing Background Threshold Values (BTVs) based on three monitoring wells placed in the Old Steese Right-of-Way. Based on preliminary evaluation of background, it appears background levels for arsenic and lead probably exceed the DEC groundwater cleanup level. Antimony background levels may be less than the groundwater cleanup level. |
Janice Wiegers |
| 7/11/2017 |
Meeting or Teleconference Held |
DEC staff met with Husky Oil and Hobbit Environmental to discuss establishing background levels in groundwater for arsenic, lead, and antimony. Use of the approach outlined by Singh, 2014 to determine a breakpoint between the site data and background data was considered. The previous background levels established for soil were also discussed. Because the background levels established in soil were derived using multi-increment samples, these background levels can only be compared to samples collected using multi-increment techniques. |
Janice Wiegers |
| 8/3/2017 |
Update or Other Action |
DEC sent letter to Husky Inc. concurring with approach discussed during the July 11th meeting to establish background levels for groundwater contamination. |
Janice Wiegers |
| 8/3/2017 |
Document, Report, or Work plan Review - other |
Hobbit Environmental submitted an ecoscoping evaluation that suggests further ecological evaluation is not necessary because the area does not provide significant habitat. The site is located in an area disturbed by dredging and is covered with tailings. Goldstream Creek, which runs along the northwestern edge of the property, has also been disturbed by historic mining activities in the vicinity. DEC consulted with the DEC Division of Water and with Alaska Fish & Game, and determined that this segment of the stream is low-value habitat and is not known to be a spawning area for grayling. |
Janice Wiegers |
| 9/13/2017 |
Document, Report, or Work plan Review - other |
Groundwater monitoring report submitted for 2016. Quarterly monitoring was completed in April, June, September, and December. MW-1 was frozen in April. The quality control review found that relative percent differences between duplicates was greater than 30% for some constituents in half of the duplicate pairs. |
Janice Wiegers |
| 9/14/2017 |
Document, Report, or Work plan Review - other |
Groundwater monitoring report summarizing 4 sampling events in 2016 submitted. Long-term monitoring of the eleven site wells continued and three additional wells (MW 12-15, 13-15, and 14-15) were sampled for background information. Samples were collected in April, June, September, and December. Arsenic, antimony, and lead exceeded DEC groundwater cleanup levels in many of the site wells. Arsenic and lead are also present in the background wells above DEC cleanup levels. High levels of variability were observed in some of the sample/duplicate pairs. Groundwater flowed to the southwest during each sampling event. |
Janice Wiegers |
| 10/25/2017 |
Update or Other Action |
DEC sent letter regarding ecoscoping report and DEC's general concurrence with conclusions unless additional information is discovered during site characterization and background evaluation that indicates additional ecological evaluation is needed. |
Janice Wiegers |
| 6/28/2019 |
Update or Other Action |
DEC contacted consultant by email to determine monitoring status. Consultant is completing monitoring early July. |
Janice Wiegers |
| 7/28/2020 |
Document, Report, or Work plan Review - other |
DEC reviewed workplan for investigation of buried ore material at the northwestern portion of the property, and on the adajcent property to the west. The final plan is dated 7/27/2020. Test pits will be excavated in the area where suspected debris and ore material is buried. Soil will be screened with an XRF and sampled. The objective of this work will be too evaluate the potential for further cleanup of this material. Workplan was approved by letter on 7/28/2021. |
Janice Wiegers |
| 3/26/2021 |
Update or Other Action |
Discussed soil contamination with DOT due to planning efforts to widen the Old Steese roadway. Levels of arsenic and antimony are elevated in this area, probably due natural background concentrations and the historic dredge tailings through this area. Worker safety, dust suppression, and notification to DEC if affected soil will be removed from the area should be considered. Monitoring wells are also in the area that need to be protected or replaced. Road construction is planned for 2023. |
Janice Wiegers |
| 3/30/2021 |
Update or Other Action |
Notified that the Husky Energy has merged with Cenovus. Updated contacts in CS database.
|
Janice Wiegers |
| 5/14/2021 |
Update or Other Action |
DEC sent a letter to Husky/Cenova asking for an update on field work completed last year. A report was expected by the end of 2020 and has not been submitted. |
Janice Wiegers |
| 5/17/2021 |
Document, Report, or Work plan Review - other |
Site characterization report delineating the extent of the remains of a stockpile of ore material was submitted. The report was dated 1/8/21 and was prepared by Hobbit Environmental. In August 2020, 36 test pits were advanced on both sides of the southwestern boundary of the Fox Mill property to depths of 6.5 feet below grade. The purpose of the test pits was to delineate the buried ore and estimated the amount to be removed. An estimate of 1,555 cubic yards was identified for removal and treatment. |
Janice Wiegers |
| 5/18/2021 |
Document, Report, or Work plan Review - other |
Groundwater Monitoring Report, dated 1/31/21 for 2017 and 2018 activities was submitted by Hobbit Environmental. In 2017 two new downgradient wells were installed (MW15-17 and MW16-17) and two were installed to the south in the DOT right-of-way (MW17-17 and MW18-17). In 2018 deeper wells (MW4D-18, MW5D-18, and MW6D-18) were installed to the bedrock interface at 23 to 27.5 ft bgs. Groundwater samples were collected quarterly from October 2017 through December 2020 for total and dissolved analyses. Upper tolerance level (UTL) background concentrations of 195 ug/L for arsenic and 35 ug/L for lead were calculated from upgradient wells. The report recommended additional delineation to the south. |
Janice Wiegers |
| 8/5/2021 |
Document, Report, or Work plan Review - other |
Work Plan to excavate buried ore material submitted. |
Janice Wiegers |
| 2/10/2022 |
Update or Other Action |
Received responses to DEC comments for work plan. DEC met with consultant to discuss plans and accepted final comments on 3/1/2022. Work plan resubmitted for final review on 3/9/22. |
Janice Wiegers |
| 4/6/2022 |
Document, Report, or Work plan Review - other |
Final workplan submitted for excavation work planned for this summer. Work plan approved in a letter sent 4/11/2022. |
Janice Wiegers |
| 4/27/2022 |
Update or Other Action |
DEC's Division of Water sent letter to Fort Knox Mine to approve processing of material to be excavated from site. Estimated amount to be processed in 1,600 cubic yards. Processed material would be disposed on in the Fort Know tailings storage facility under Waste Management Permit 2020DB0002. |
Janice Wiegers |
| 7/1/2022 |
Document, Report, or Work plan Review - other |
Hobbit Environmental submitted a work plan addendum to further characterize hexavalent chromium in the ore material that will be excavated from the site due to preliminary sampling results which indicated hexavalent chromium may be present in tailings. Multi-increment samples will be collected to further characterize chromium. |
Janice Wiegers |
| 8/31/2022 |
Document, Report, or Work plan Review - other |
Plan for stockpiling excavated material for the winter submitted. This plan will be used in the event that the material cannot be transported to Ft. Knox for treatment this fall and will be transported in the spring instead. The material will be stored in a lined, bermed and covered cell on the Husky property. A 30 mil liner will be used, and samples will be collected after the material is removed beneath the liner and in along the haul route to make sure contaminated material is fully removed. DEC approved plan on 9/2/22. |
Janice Wiegers |
| 10/14/2022 |
Site Visit |
DEC conducted a site visit at the Fox Mill property to observe excavation activities on the adjacent property where ore material was also found. The excavation is mostly shallow, but extends to about 6 feet deep in some area. The material is being stockpile on a bermed liner and will be covered and prior to winter. Sample results should be back in two weeks, at which time final decisions about excavation and backfilling will be made. Backfill has been brought to and stored on the property as the backfill source will be closing for the winter. |
Janice Wiegers |
| 3/8/2023 |
Update or Other Action |
Cleanup report submitted for excavation of ore material conducted in October 2022. Excavation work was guided by screening with an X-Ray Fluorescence (XRF) and visual identification of the buff-colored ore material. Approximately 1,350 cubic yards of ore material were removed and stockpiled in a lined and bermed staging area on the property. Post-excavation samplinng was completed using incremental sampling methods on 10 decision units, with samples collected in triplicate. All samples were below DEC cleanup levels, or the approved background level for antimony and arsenic. Total chromium and chromium +6 were both analyzed. The stockpile was covered for disposal in the spring. |
Janice Wiegers |
| 5/5/2023 |
Document, Report, or Work plan Review - other |
DEC sent letter approving the March 2023 excavation report and discussing requirements for ongoing groundwater investigation and long-term monitoring. Groundwater investigation of the Henderson property where the cleanup was completed in 2022 is needed. |
Janice Wiegers |
| 6/15/2023 |
Offsite Soil or Groundwater Disposal Approved |
Approved transport of 1400 cubic yards of ore material to Ft. Knox gold mine for processing. Prior to transport, and transport plan will be provided to DEC for review. |
Janice Wiegers |
| 6/15/2023 |
Update or Other Action |
Workplan to haul 1,400 cubic yards of the contaminated ore material to Ft. Knox for processing and disposal submitted by consultant. The plan indicates that three 20-yard side dumps will be used to haul the material, which will result in 9 round trips a day for 9-11 days, depending on time required by DOT to weigh the loads. Each load will be covered. Following removal of the liner, a triplicated sample will be collected using a multi-increment approach to confirm that soil beneath the liner meets the cleanup or background levels. Plan approved on 7/24. |
Janice Wiegers |
| 11/3/2023 |
Site Characterization Workplan Approved |
Hobbit Environmental submitted a revision to the well installation and groundwater monitoring plan, dated 11/2/2023. DEC approved the plan. Three new monitoring wells we be placed in and near the recent excavation to evaluate groundwater impacts. All monitoring wells will be sampled for metals, including arsenic, antimony, and Cr+6. The report will evaluate seasonal variation and trends associated with the groundwater data which has been collected since 2017. DEC discussed options for additional comparison of a low flow sampling approach to bailers. The consultant indicated that will be considered in future sampling events. |
Janice Wiegers |
| 5/30/2024 |
Document, Report, or Work plan Review - other |
DEC approved amendment to groundwater monitoring plan, which includes using hydrasleeves and low flow sampling instead of bailers. |
Janice Wiegers |
| 7/31/2024 |
Update or Other Action |
DEC sent a letter approving continued use of the stockpile liner through December 31, 2025. Hobbit Environmental will be conditioning the stockpile for processing by Ft. Knox this fall. Conditioning includes removing the large organic materials. Repairs to the liner will be made if necessary. |
Janice Wiegers |
| 8/7/2024 |
Document, Report, or Work plan Review - other |
Groundwater monitoring report submitted. |
Janice Wiegers |
| 8/28/2024 |
Update or Other Action |
Hobbit Environmental inspected the stockpile and notified DEC that the cover was damaged and partly missing. DEC sent a letter to Cenovus requesting that the stockpile cover be repaired and that documentation of that be provided by September 26th. |
Janice Wiegers |
| 9/27/2024 |
Update or Other Action |
Cenovus provided a photograph of the stockpile which has been covered with an additional liner. |
Janice Wiegers |
| 10/7/2024 |
Document, Report, or Work plan Review - other |
Arcadis submitted a memo describing installation of a 6-ml synthetic top liner over the stockpile to repair the damaged cover. The brush was cleared from the pile before covering, and sandbags were used to hold the cover down. |
Janice Wiegers |
