| Action Date |
Action |
Description |
DEC Staff |
| 11/7/1996 |
Site Added to Database |
|
Former Staff |
| 11/7/1996 |
Leaking Underground Storage Tank Release Confirmed - Petroleum |
LUST Site created in CSP for source area ID 77895 ADD; Site added. |
Former Staff |
| 11/20/1997 |
Update or Other Action |
ADEC sends Notification of Intent to Cost Recover Letter to Current Owner: MAPCO EXPRESS INC |
Former Staff |
| 12/14/1998 |
Leaking Underground Storage Tank Corrective Action Underway |
Letter CAP submitted by Gilfilian |
Former Staff |
| 1/12/1999 |
Underground Storage Tank Site Characterization or Assessment |
Completed SA - Gilfilian |
Former Staff |
| 1/12/1999 |
Leaking Underground Storage Tank Cleanup Initiated - Petroleum |
entered by JC |
Former Staff |
| 7/1/1999 |
Site Visit |
John Carnahan visited the site to see the system layout and evaluate the location of new UST installation. |
Former Staff |
| 10/21/1999 |
Update or Other Action |
SVE/AS is ready to activate - Gilfilian intends to start system within month. |
Former Staff |
| 10/21/1999 |
Update or Other Action |
Tesoro elects to close out newly installed UST due to secondary containment failure. ADEC does not contest in-place closure since there is no evidence that the tank leaked. New installation takes place Sept/Oct 1999. |
Former Staff |
| 12/1/2000 |
Long Term Monitoring Established |
Received September 2000 Monitoring Event and Comprehensive Analysis report. (also received monitoring reports for earlier quarters this year). |
Monica English |
| 9/30/2001 |
Long Term Monitoring Established |
Received July 2001 Monitoring Event & Comprehensive Analysis report. (also received monitoring reports for previous quarters this year) |
Monica English |
| 8/30/2002 |
Long Term Monitoring Established |
Received April 2002 Monitoring Event report. (also received report for Jan 2002 monitoring event). |
Monica English |
| 1/26/2004 |
Document, Report, or Work plan Review - other |
September 2003 Release Investigation and Well Installation and October 2003 Monitoring Event report. |
Monica English |
| 2/23/2004 |
Update or Other Action |
Departmental comments to the proposed 2004 work plan and request for installation of additional monitor well to characterize downgradient groundwater quality. |
Monica English |
| 4/15/2004 |
Update or Other Action |
Departmental approval of 2004 Work Plan. |
Monica English |
| 6/29/2004 |
Document, Report, or Work plan Review - other |
March 2004 Monitoring Event report. Grouondwater contaminant trends consistent with previous monitoring events. Monitor well MW1 continues to exceed groundwater cleanup levels for benzene and is just below the cleanup level for diesel range organics. The soil vapor extraction (SVE) remediation system was evaluated and continues to operate. |
Monica English |
| 9/8/2004 |
Update or Other Action |
Addendum to the Corrective Action Work Plan for 2004. |
Monica English |
| 9/9/2004 |
Update or Other Action |
Departmental approval for the addendum to the 2004 Workplan. |
Monica English |
| 11/15/2004 |
Update or Other Action |
Staff attend the annual environmental planning meeting with Tesoro and MWH to discuss proposed activites for the 2005 work plan. |
Monica English |
| 2/22/2005 |
Update or Other Action |
ADEC issues approval for the 2005 calendar year Corrective Action work plan. |
Monica English |
| 10/9/2006 |
Update or Other Action |
Project manager changed from Monica English to Paul Horwath, per Paul Horwath. |
Alyce Hughey |
| 3/7/2007 |
Document, Report, or Work plan Review - other |
Reviewed MWH's Tesoro 2 Go Mart #112 November 2006 Monitoring Event Report Final, dated February 2007. Air sparge and SVE soil and groundwater treatment systems remain in operation at this site, combined with continued GW quality monitoring. High GW contaminant concentrations remain, however groundwater quality is slowly improving. |
Paul Horwath |
| 12/26/2007 |
Document, Report, or Work plan Review - other |
Reviewed the May 2007 Monitoring Event Report Final prepared by MWH, dated August 2007. Groundwater quality has improved since the prior monitoring event and improved greatly since beginning soil and GW treatment with the air sparge / SVE treatment system. MW-2 and MW-3 still exceed ADEC GW cleanup levels. |
Paul Horwath |
| 12/26/2007 |
Exposure Tracking Model Ranking |
Initial ETM site ranking completed. |
Paul Horwath |
| 4/24/2008 |
Document, Report, or Work plan Review - other |
Reviewed MWH's October 2007 Monitoring Event Report Final, dated March 2008. Air sparge and soil vapor extraction treatment continues at this site. GW contamination remains in the vicinity of the former tank site, with a declining concentration trend apparent. |
Paul Horwath |
| 10/16/2008 |
Document, Report, or Work plan Review - other |
Reviewed the April 2008 Monitoring Event Report, Dated July 2008 for Paul Horwath, and provided him a summary for his review and oversite. Site conditions remain stable, and the contamination continues to remain around the underground storage tanks. Overall the hydrocarbon concentrations are decreasing. |
Alyce Hughey |
| 12/5/2008 |
Update or Other Action |
Reviewed the October 2008 Monitoring Event Report, dated November 2008, from MWH for Paul Horwath. Site conditions remain stable. The contamination continues to remain around the underground storage tanks, and overall the concentrations are decreasing. The monitoring wells down-gradient, towards Beaver Creek remain undetected. |
Alyce Hughey |
| 8/20/2009 |
Document, Report, or Work plan Review - other |
Reviewed the May 2009 Monitoring Event Report, dated July 2009, from MWH for Paul Horwath. The groundwater concentrations have continued to show an increasing trend over the past few monitoring events, along with increased groundwater elevations. The groundwater concentrations have remained lower since the remediation project has begun, and the contamination continues to remain around the existing underground storage tanks. The groundwater monitoring wells down gradient, towards Beaver Springs Creek continues to remain undetected. |
Alyce Hughey |
| 2/16/2010 |
Document, Report, or Work plan Review - other |
Reviewed the October 2009 Monitoring Event Report, dated January 2010, from MWH for Paul Horwath. Since the May 2009 groundwater sampling event, GRO hydrocarbon concentrations have increased in the two groundwater monitoring wells closest to the existing underground storage tanks at the facility. The monitoring well tested further downgradient, towards Beaver Springs Creek continues to remain undetected. The Soil Vapor Extraction and Air Sparging system was shut off for repairs, and the repair work will be performed through a subcontractor. Once the repair work is completed the remediation systems will be operational in order to address the soil and groundwater impacts at the site. |
Alyce Hughey |
| 7/6/2010 |
Document, Report, or Work plan Review - other |
Reviewed the results for an additional sampling event for Sulfolane, conducted on June 15th and 16th, 2010 from MW-3 located on the site. Sample results are non-detect for Sulfolane from MW-3. |
Alyce Hughey |
| 9/15/2010 |
Site Characterization Workplan Approved |
Reviewed and approved the July 14, 2010 Supplemental Work Plan for Chemical Oxidation Treatment, Tesoro 2 Go Mart #112, from MWH for the injection of potassium permanganate into the groundwater via multiple existing wells. |
Paul Horwath |
| 11/5/2010 |
Document, Report, or Work plan Review - other |
Reviewed the June 2010 Monitoring Event Report, dated October 2010, from MWH. During the June 15, 2010 groundwater sampling event, of the six monitoring wells sampled only one well remains above the groundwater cleanup levels, three wells were undetected for all analytes tested for, and two showed detections but were below the groundwater cleanup levels. The air sparge and soil vapor extraction systems are operating 24 hours a day with the air sparge system operating in a concentrated area around the area of the former underground storage tanks. The data collected during the June sampling event shows that the elevated hydrocarbon concentrations remains near the former underground storage tanks, and the downgradient wells toward Beaver Springs Creek continues to remain undetected. |
Alyce Hughey |
| 11/16/2010 |
Meeting or Teleconference Held |
Staff attended the annual environmental planning meeting with Tesoro and MWH to discuss the workplans for 2011. |
Alyce Hughey |
| 11/16/2010 |
Meeting or Teleconference Held |
Staff attended the annual environmental planning meeting with Tesoro and MWH to discuss the workplans for 2011. |
Paul Horwath |
| 1/5/2011 |
Document, Report, or Work plan Review - other |
Reviewed the October 2010 Monitoring Event Report, dated November 2010, from MWH. During the October 14, 2010 groundwater sampling event, three monitoring wells were sampled. MW-10, located just down-gradient of the source area showed high concentrations of GRO at 126 mg/L. The further most down-gradient monitoring well located next to Beaver Springs Creek, however, continues to test un-detect for all analytes tested, indicating that the plume remains centrally located on the west side of the Tesoro station building (former underground storage tank area) and the current dispenser area. The air sparge and soil vapor extraction systems continue to operate 24 hours a day. |
Alyce Hughey |
| 7/21/2011 |
Document, Report, or Work plan Review - other |
Reviewed the May 2011 Monitoring Event Report, dated June 2011, from MWH. The May 24, 2011 groundwater sampling event showed some decreases in concentrations within monitoring well MW-3 from the October 2010 sampling event. Concentrations do remain high within MW-3; therefore, some soil vapor and air sparge system adjustments were made to target treatment at MW-3 to help reduce the concentrations in the groundwater within that area. The adjustments to the treatment systems showed an increase in dissolved oxygen levels from 0.29 mg/L on May 24, 2011 to 9.19 mg/L on June 9, 2011. A vertical control survey was performed during this monitoring event to update the monitoring well measurements. |
Alyce Hughey |
| 12/1/2011 |
Meeting or Teleconference Held |
Staff attended the annual environmental planning meeting with Tesoro and MWH to discuss the workplans for 2012. |
Alyce Hughey |
| 12/1/2011 |
Meeting or Teleconference Held |
Staff attended the annual environmental planning meeting with Tesoro and MWH to discuss the workplans for 2012. |
Paul Horwath |
| 1/10/2012 |
Document, Report, or Work plan Review - other |
Reviewed the October 2011 Monitoring Event Report, dated December 2011, from MWH. The October 26, 2011 groundwater sampling event, monitoring well MW-3 showed a decrease in all analytes other than Ethylbenzene and DRO that showed increases, with all analytes still testing above the groundwater cleanup levels. The high GRO concentrations are coming down where DRO are showing an increasing trend within MW-3. The monitoring wells tested next to Beaver Springs Creek continue to not detect any of the analytes within the wells. The readings for dissolved oxygen within the monitoring wells were low during this sampling event, indicating that the air sparge system is not operating effectively. The system is planned on being evaluated during the first quarter of 2012. |
Alyce Hughey |
| 6/6/2012 |
Meeting or Teleconference Held |
Staff attended the mid-year planning meeting at the ADEC office in Soldotna to discuss the Supplemental Work Plan for Chemical Oxidation Treatment to be conducted in 2012 at Tesoro Northstore #112. |
Alyce Hughey |
| 6/8/2012 |
Document, Report, or Work plan Review - other |
Approved the Supplemental Work Plan for Chemical Oxidation Treatment, dated June 1, 2012, prepared by MWH. Approximately 500 pounds of Klozur CR will be injected into the proposed air sparge wells (AS-11, AS-12, AS-13, AS-14, AS-15 and AS-16) at a 12 percent solution. |
Paul Horwath |
| 11/14/2012 |
Meeting or Teleconference Held |
Paul Horwath and Alyce Hughey attended the annual planning meeting at MWH office in Anchorage to discuss the Corrective Action Work Plan for 2013. |
Alyce Hughey |
| 12/19/2012 |
Document, Report, or Work plan Review - other |
Reviewed the May 2012 Monitoring Event Report, dated October 2012, prepared by MWH. The first semiannual groundwater sampling event for 2012 was conducted on May 22, 2012 with samples collected from MW-1, MW-2, MW-3, MW-4, MW-6 and MW-10. Two wells remain with concentrations exceeding the groundwater cleanup levels, MW-2 and MW-3. MW-2 had benzene at 0.00566 mg/L and GRO at 5.17 mg/L. MW-3 had benzene at 0.141 mg/L, toluene at 2.00 mg/L, ethylbenzene at 0.717 mg/L, xylenes at 11.6 mg/L, GRO at 38.4 mg/L and DRO at 5.22 mg/L. On June 1, 2012, the soil vapor extraction system was operating and the air sparge system was not. It was determined that the air sparge system needed a new compressor and was replaced on June 25, 2012. The air sparge system is planned to be evaluated on how performance can be improved. |
Alyce Hughey |
| 2/19/2013 |
Document, Report, or Work plan Review - other |
Reviewed the October 2012 Monitoring Event Report, dated January 2013, prepared by MWH. The second semiannual groundwater sampling event for 2012 was conducted on October 11, 2012, with samples collected from MW-2, MW-3, MW-6 and MW-10. Concentrations decreased in MW-2 to below the groundwater cleanup levels, and MW-3 had a decrease in all analytes with only Benzene and GRO remaining above the groundwater cleanup levels. On October 9, 2012, the remediation system was checked. The soil vapor extraction system is operating with air being supplied to a group of wells along the southern section of the treatment zone. During the remediation system check it was determined that the system requires further assessment and repair work, which is scheduled for early in 2013. On August 29, 2012 a total of 65-gallons of Klozur CR was applied, 10-gallons into SVE-7 and 55-gallons into SVE-9, with 150-gallons of water into SVE-9 following the application to further distribute the oxidant. On October 9, 2012 a total of 65-gallons of Klozur CR was applied into SVE-9 and then 150-gallons of water to increase distribution. |
Alyce Hughey |
| 7/17/2013 |
Document, Report, or Work plan Review - other |
Reviewed the May 2013 Monitoring Event Report, dated July 2013, prepared by MWH. The first semiannual groundwater sampling event for 2013 was conducted on May 21, 2013, with samples collected from MW-1, MW-2, MW-3, MW-4, MW-6 and MW-10. The depth to groundwater was 9.18 to 13.44 feet. Groundwater was flowing with a northeasterly flow direction, with a bearing of 57 degrees, with a gradient of 0.0047. Monitoring well MW-3 concentrations returned to levels representative to the October of 2010 and May 2011 concentrations, with Benzene at 1.50 mg/L, Toluene at 11.2 mg/L, Ethylbenzene at 2.39 mg/L, Xylenes at 15.9 mg/L, GRO at 70 mg/L and DRO at 13.3 mg/L. The SVE/AS system is currently not operating as it was determined that the system requires further assessment and repair work. The repair work is tentatively scheduled for the third quarter of 2013, contingent upon the results of a new in-situ remediation system designed for the Tesoro Northstore #111. |
Alyce Hughey |
| 7/30/2013 |
Meeting or Teleconference Held |
Staff attended the mid-year planning meeting at the ADEC office in Soldotna to discuss the condition of the AS and SVE wells and future treatment options that are being discussed to treat the soil and groundwater contamination. |
Alyce Hughey |
| 11/25/2013 |
Document, Report, or Work plan Review - other |
Reviewed the September 2013 Monitoring Event Report, dated November 2013, from MWH. The second semiannual groundwater sampling event for 2013 was conducted on September 25, 2013, with samples collected from MW-2, MW-3, MW-6 and MW-10. The depth to groundwater was 9.15 to 13.31 feet. Groundwater was flowing with a northeasterly flow direction, with a bearing of 51 degrees, with a gradient of 0.0045. Monitoring well MW-3 concentrations showed some decreases with Benzene at 0.102 mg/L, Toluene at 4.01 mg/L, Ethylbenzene at 1.93 mg/L, Xylenes at 23.9 mg/L, GRO at 47.9 mg/L and DRO at 4.69 mg/L. The SVE/AS system is currently not operating as it was determined that the system requires further assessment and repair work. The repair work is tentatively scheduled for the third quarter of 2014. |
Alyce Hughey |
| 12/3/2013 |
Meeting or Teleconference Held |
Paul Horwath and Alyce Hughey attended the ADEC/Tesoro Annual planning meeting held at the MWH office In Anchorage to discuss the Corrective Action Plan for 2014, the current groundwater concentrations and the future applications of Chem-Ox. |
Alyce Hughey |
| 7/2/2014 |
Document, Report, or Work plan Review - other |
Reviewed the May 2014 Monitoring Event Report, dated June 2014, prepared by MWH. The first semiannual groundwater sampling event for 2014 was conducted on May 6, 2014, with samples collected from MW-1, MW-2, MW-3, MW-4, MW-6 and MW-10. The depth to groundwater was 9.02 to 13.33 feet. Groundwater was flowing with a northeasterly flow direction, with a bearing of 54 degrees, with a gradient of 0.0047. Monitoring well MW-3 concentrations showed some decreases with Benzene at 0.037 mg/L, Toluene at 0.470 mg/L, Ethylbenzene at 0.420 mg/L, Xylenes at 3.8 mg/L, GRO at 12.0 mg/L and DRO at 4.70 mg/L. The SVE/AS system is still currently not operating and is tentatively scheduled for the third quarter of 2014 to be repaired, contingent upon the results of a new in-situ remediation system designed for the Tesoro Northstore #111. |
Alyce Hughey |
| 10/6/2015 |
Cleanup Plan Approved |
Issued approval of the October 1, 2015 Supplemental Work Plan for Chemical Oxidation Treatment, which was prepared by MWH. |
Paul Horwath |
| 10/6/2015 |
Update or Other Action |
Lat/Long coordinates collected and verified using CSP Internal ArcGIS.com web map. Location coordinates entered in the ADEC CSP database.
Lat 64.759292 Long -147.350082 |
Paul Horwath |
| 10/7/2015 |
Document, Report, or Work plan Review - other |
Reviewed the September 2014 Monitoring Event Report, prepared by MWH, and dated September 2015. Report received one year after GW sample collection. GW conditions similar to prior, recent monitoring events. |
Paul Horwath |
| 10/8/2015 |
Document, Report, or Work plan Review - other |
Reviewed the May 2015 Monitoring Event Report, prepared by MWH, and dated September 2015. GW conditions similar to prior, recent monitoring events. |
Paul Horwath |
| 12/1/2016 |
Meeting or Teleconference Held |
Paul Horwath attended the ADEC/Tesoro Annual projects meeting held at the MWH office in Anchorage to review corrective action work accomplished in 2016, and to discuss the Corrective Action Work Plan for 2017. |
Paul Horwath |
| 6/29/2017 |
Site Characterization Workplan Approved |
Issued ADEC work plan approval for soil boring and chem-ox treatment well installations. |
Paul Horwath |
| 9/19/2017 |
Offsite Soil or Groundwater Disposal Approved |
ADEC authorized the transport of soil to the ADEC approved OIT soil treatment facility. Estimated quantity of contaminate soils = 1/4 cyd. |
Paul Horwath |
| 10/17/2017 |
Document, Report, or Work plan Review - other |
Complete review of Stantec's May 2017 GW Monitoring Report. Persistent GW contamination in areas with historical free product (LNAPL). MW-2 and MW-3. |
Paul Horwath |
| 12/4/2017 |
Document, Report, or Work plan Review - other |
Receive and reviewed a Stantec prepared September, 2017 GW Sampling and Analysis report. No 8260 or 8270 methods included in lab analyses. GW quality consistent with years of prior GW sampling data. |
Paul Horwath |
| 12/7/2017 |
Meeting or Teleconference Held |
Meeting with Tesoro's Anne Duarte and Stantec staff at the offices of Stantec in Anchorage. Review work accomplished in 2017, and assessment/cleanup work proposed for 2018. |
Paul Horwath |
| 11/25/2019 |
Document, Report, or Work plan Review - other |
Chemox treatment 2x per year in RW17-1, RW17-3, RW17-4 and RW17-6. |
Peter Campbell |
| 12/12/2019 |
Meeting or Teleconference Held |
Meeting with Tesoro, consultant and ADEC to discuss corrective action plan. |
Peter Campbell |
| 12/16/2019 |
Update or Other Action |
Corrective Action Work Plan for 2020 approved. The plan calls for chemox treatment, sampling and monitoring. |
Peter Campbell |
| 2/18/2020 |
Document, Report, or Work plan Review - other |
Review October 2019 Monitoring Event Report. No significant changes to conditions at site. |
Peter Campbell |
| 10/27/2020 |
Update or Other Action |
The third and fourth quarter monitoring events were completed. We completed 2 separate injections of Klozur One in the 4 remediation/injection wells located in the buried source of contaminated soil in the area of the former fuel dispenser island.
|
Peter Campbell |
| 12/28/2020 |
Document, Report, or Work plan Review - other |
No significant changes discovered during routine monitoring. Groundwater flow direction and contaminant concentrations are consistent from previous sampling. |
Peter Campbell |
| 1/27/2021 |
Document, Report, or Work plan Review - other |
Review October 2020 Report. Trend for contaminated wells is downward. Treatment with Chemox Reduction compounds continuing with air sparge and vapor extraction. |
Peter Campbell |
| 2/1/2021 |
Document, Report, or Work plan Review - other |
Review the 2020 Corrective Action Plan. Monitoring and treatment will continue. Monitor wells MW-3, MW17-2 and MW17-5 remain impacted. |
Peter Campbell |
| 2/11/2021 |
Document, Report, or Work plan Review - other |
2021 Corrective Action Plan ADEC Approval |
Peter Campbell |
| 11/1/2021 |
Document, Report, or Work plan Review - other |
June 2021 semi-annual groundwater monitoring included measuring the depth to groundwater, measuring water quality parameters, and collecting groundwater samples from Monitoring Wells MW-2, MW-3, MW-6, MW-10, MW 17-2, and MW 17-5. Results from groundwater measurements indicate the hydraulic gradient was 0.0054 feet per foot with flow east-northeast at 80 degrees. The gradient was consistent with the historical values, and the flow direction was in the same quadrant. Results of the analytical sampling showed petroleum analytes were present at concentrations exceeding ADEC groundwater cleanup levels in Table C for the following wells sampled: MW-3: Benzene, Ethylbenzene, Xylenes, Naphthalene, GRO, DRO, 1,2,4-TMB and 1,3,5-TMB. MW 17-2: Ethylbenzene, DRO, 1,2,4-TMB and Naphthalene. The remediation event on October 7th, 2020, consisted of a chemox injection of Klozur One into four treatment wells (RM 17-1, RM 17-3, RM 17-4, and RM 17-6). The chemox solution was “hydraulically pushed” into the subsurface formation with an additional 200 gallons of water into each remediation well.
|
Peter Campbell |
| 11/1/2021 |
Document, Report, or Work plan Review - other |
June 2021 semi-annual groundwater monitoring included measuring the depth to groundwater, measuring water quality parameters, and collecting groundwater samples from Monitoring Wells MW-2, MW-3, MW-6, MW-10, MW 17-2, and MW 17-5. Results from groundwater measurements indicate the hydraulic gradient was 0.0054 feet per foot with flow east-northeast at 80 degrees. The gradient was consistent with the historical values, and the flow direction was in the same quadrant. Results of the analytical sampling showed petroleum analytes were present at concentrations exceeding ADEC groundwater cleanup levels in Table C for the following wells sampled: MW-3: Benzene, Ethylbenzene, Xylenes, Naphthalene, GRO, DRO, 1,2,4-TMB and 1,3,5-TMB. MW 17-2: Ethylbenzene, DRO, 1,2,4-TMB and Naphthalene. The remediation event on October 7th, 2020, consisted of a chemox injection of Klozur One into four treatment wells (RM 17-1, RM 17-3, RM 17-4, and RM 17-6). The chemox solution was “hydraulically pushed” into the subsurface formation with an additional 200 gallons of water into each remediation well.
|
Peter Campbell |
| 12/2/2021 |
Document, Report, or Work plan Review - other |
Review 2022 Corrective Action Plan. Chemox treatment will continue quarterly. The former air sparge and soil vapor extraction system is to be decommissioned. |
Peter Campbell |
| 12/8/2021 |
Meeting or Teleconference Held |
2022 Corrective Action Work Plan meeting |
Peter Campbell |
| 12/8/2021 |
Document, Report, or Work plan Review - other |
2022 Corrective Action Work Plan ADEC Work Plan Approval |
Peter Campbell |
| 2/9/2022 |
Document, Report, or Work plan Review - other |
Review and approve the October 2021 GWM Event Report. Groundwater flow and direction is consistent with historical trends. Chemox treatment of groundwater is continuing. Sodium levels and specific conductance are increasing in MW-17-2 and MW-17-5, indicating possible impact from chemox treatments. BTEX and GRO concentrations are in a general downward trend. |
Peter Campbell |
| 8/30/2022 |
Document, Report, or Work plan Review - other |
Review 2nd Quarter 2022 report. Scheduled oxidizer was not applied during the 2nd Quarter due to severe weather conditions. MW-10 had anomalous benzene concentrations that will be investigated. |
Peter Campbell |
| 9/13/2022 |
Update or Other Action |
Stantec proposes substituting the abandonment of the current remediation system with the following scope of work: Task 3 – Replace the Existing 2-inch diameter Chemox Injection Remediation Wells RW 17-1, RW 17-3, RW 17-4 and RW-17-6 with 4-inch diameter Chemox Injection Wells.
The existing 2-inch diameter wells do not accept the chemox solution readily and severely hampers the injection of an adequate amount of chemox during the routine monthly injection process. Stantec proposes to replace each of the four 2-inch diameter injection wells (RW 17-1, RW 17-3, RW 17-4 and RW-17-6 as shown on the attached site plan) with 20-foot deep, 4-inch diameter PVC wells. To facilitate the injection of the chemox solution the wells will be screened from 5-foot depth to the bottom of the well casing. The replacement wells will be placed approximately 1 to 2 feet from the existing injection wells. The new wells will be flush grade with a protective well access manhole. Stantec proposes to drill the replacement wells during the first week of October 2022. Upon completion of the well installation, Stantec will submit as record drawing report to ADEC for documentation on the well construction.
Plan approved. |
Peter Campbell |
| 11/30/2022 |
Long Term Monitoring Workplan or Report Review |
Review the Tech Memo Installation of 4" Chemox Injection Wells. Installation of 4 injection wells. Injection wells were relatively clean with only ethylbenzene and naphthalene detected, primarily in the smear zone. |
Peter Campbell |
| 11/30/2022 |
Long Term Monitoring Workplan or Report Review |
Review September 3rd Quarter 2022 Groundwater Monitoring Event Report. Chemox injections were conducted monthly between June and October 2022. The new 4” injection well significantly improved moving chemox into the formation. |
Peter Campbell |
| 12/1/2022 |
Long Term Monitoring Workplan or Report Review |
Review Supplemental Report for October 2022 Groundwater Monitoring Event. Sampling event to assess the effectiveness of injecting chemox into the groundwater. Sodium was elevated in MW -17-2. MW-3 had the highest measured hydrocarbon levels of the three wells sampled during this event. |
Peter Campbell |
| 12/1/2022 |
Long Term Monitoring Workplan or Report Review |
Review the 2023 Corrective Action Plan. Continuation of the chemox treatment and monitoring. New injection wells have been installed. Some of the planned decommissioning of the soil vapor extraction system from last year's plan was not conducted. Details of this plan will be discussed in the annual meeting next week. |
Peter Campbell |
| 12/6/2022 |
Meeting or Teleconference Held |
Annual meeting to discuss 2022 work and the 2023 Corrective Action Work Plan. |
Peter Campbell |
| 5/3/2023 |
Offsite Soil or Groundwater Disposal Approved |
Approval to dispose 65 gallons of investigation derived waste soil. |
Peter Campbell |
| 12/7/2023 |
Meeting or Teleconference Held |
Annual meeting held to discuss the past years accomplishments and the 2024 Corrective Action Plan. MW-3 is still showing impacts, but the wells are cleaning up with the Closure influence. |
Peter Campbell |
| 12/7/2023 |
Long Term Monitoring Workplan or Report Review |
Corrective Action Work Plan reviewed and approved. |
Peter Campbell |
| 12/8/2023 |
Long Term Monitoring Workplan or Report Review |
Review and approve the July, August and September 3rd Quarter 2023 GWM Event Report. There were significant reductions in contaminant mass as measured by water quality results. MW-3 is still impacted. |
Peter Campbell |
| 12/8/2023 |
Long Term Monitoring Workplan or Report Review |
Review and approve the 4th Quarter October 2023 GWM Event Report. MW-3 still has low level impacts and is moving toward site closure. |
Peter Campbell |
| 2/28/2024 |
Long Term Monitoring Workplan or Report Review |
Routine GW Monitoring and Chemox injections June 2023. Second Monitoring event for the second quarter 2023 occurred on June 7, 2023, for the analytical sampling of Monitoring Wells MW-6, MW17-2, and MW17-5. 1,2,4-TMB concentrations in both wells MW17-2 and MW17-5 are high compared to the other wells at this site. Benzene was only detected in well MW17-5. Well MW17-2 and the duplicate sample had high levels of naphthalene detected in excess of groundwater cleanup levels (GCLs). Wells MW17-2 and MW17-5 were the only wells in which Ethylbenzene was detected above GCLs. The duplicate sample was the only one to show the level of DRO equaled the GCL. The precision for the duplicate sample set exceeded the established QA criteria tolerance for total xylenes.
|
Peter Campbell |
