| Action Date |
Action |
Description |
DEC Staff |
| 7/1/1999 |
Site Ranked Using the AHRM |
Ranked by Site Intake staff. |
Deborah Williams |
| 10/19/1999 |
Site Added to Database |
DRO/GRO, ethylbenzene, xylene, and PCE above MCLs. |
Don Fritz |
| 12/10/1999 |
Site Characterization Workplan Approved |
Work plan for additional site assessment approved. Cautioned RP that additional monitor wells may be required |
Don Fritz |
| 1/6/2000 |
Site Ranked Using the AHRM |
Site ranked. GW Usage Value changed from 0.1 to 0.8 and SW Environments changed from 2 to 0. Score increased. |
Don Fritz |
| 8/15/2000 |
Site Characterization Workplan Approved |
Plan for additional groundwater assessment approved |
Don Fritz |
| 6/20/2003 |
Site Characterization Workplan Approved |
Plan for additional groundwater assessment approved |
Don Fritz |
| 5/5/2004 |
Update or Other Action |
File number assigned and entered into the Fileroom DB and CS DB. |
Alyce Hughey |
| 5/19/2004 |
Meeting or Teleconference Held |
Met with Gary Lamb, Kenai Peninsula Borough to determine who from the borough would be providing oversite for the project with the departure of Rachael. Gary was not aware thatt eh borough owned the property, and indicated that he would oversee in the interim. |
Don Fritz |
| 5/24/2004 |
Site Characterization Report Approved |
Provided letter to GE concurring with the possibility of long term remediation for the site if additional wells are installed, but recommending that they consider active remediation. Have had several phone calls with URS regarding active remedial options. |
Don Fritz |
| 8/9/2004 |
Update or Other Action |
Reviewed correspondence from URS identifying that they will be undertaking a microcosm study to determine bio-augmentation methods for site remediation. |
Don Fritz |
| 6/27/2005 |
GIS Position Updated |
Using Figure 1 and 2 from 2003 Well Instalation and Groundwater Sampling Former TBE Machine Shop, Mile 22.5 Kenai Spur Highway, dated October 2003 from URS in conjunction with TopoZone Pro and KPB Parcel Lookup, entered the coordinates for this site. Metadata include No Topo Basemap, TopoZone Pro Street Map, Black and White Aerial Photo, on a Medium Size Map View Scale 1:10,000, Coordinate Datum NAD83. High degree of confidence in accuracy of location. |
Alyce Hughey |
| 4/14/2008 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed. |
Don Fritz |
| 11/9/2010 |
Update or Other Action |
Phone call with Dawn Varacchi- General Electric. Dawn provided me with an update on their approach for the site. GE has undertaken a pilot project to enhance in-situ remediation of the remaining contamination. The bench scale test has defined the best alternatives for enhanced bioremediation to meet groundwater cleanup levels. Dawn told me that URS has provided her with a draft report. Dawn intends to provide any comments to URS in the near future, and then to provide us with a work plan this year, so that the implementation could begin in the spring. Dawn envisions a few injection points initially, with monitoring to determine the need for further augmentation. |
Don Fritz |
| 1/19/2011 |
Document, Report, or Work plan Review - other |
Reviewed the Groundwater Monitoring Report September 2008 Sampling Event, dated February 20, 2009, from URS Alaska, for Don Fritz. Monitoring well MW-5 detected GRO, DRO, RRO, Ethylbenzene and PCE above the groundwater cleanup levels. Monitoring wells MW-1, MW-4, and MW-7 detected TCA, PCE, TCE or a combination of the analytes above the groundwater cleanup levels. The hydrocarbon and VOC impacted groundwater remains below the site. Based on the data submitted to date the residual soil and groundwater contamination at the site poses a low risk to human health and the environment. |
Alyce Hughey |
| 1/25/2011 |
Document, Report, or Work plan Review - other |
Reviewed the Corrective Action Plan Former TBE Machine Shop Property, dated January 5, 2011, from URS Alaksa, for Don fritz. Based on the GE Global Research Microcosm Study results and cost comparisons performed the best remediation option of decreasing the PCE contamination in the subsurface is an enhanced bioremediation option. The corrective actions proposed are the installation of one additional groundwater monitoring well, the installation of ten injection wells, two groundwater sampling events in 2011 and 2012, and four rounds of injections of KB-1 and WILCLEAR into the ten installed injection wells, two in 2011 and two in 2012. |
Alyce Hughey |
| 11/16/2011 |
Update or Other Action |
Site transferred from Don Fritz to Peter Campbell per Paul Horwath. |
Alyce Hughey |
| 4/24/2013 |
Document, Report, or Work plan Review - other |
Reviewed a Work Plan for the former TBE Machine Shop Property, dated April 16, 2013, from URS Alaska, for the installation of two in-well treatment wells designed to treat chlorinated solvents and petroleum compounds. The wells and associated equipment will use air-stripping, air sparging, soil vapor extraction, enhanced bio-remediation/oxidation and subsurface circulation to treat water and soils in the unsaturated zone. The wells are scheduled to be installed in the summer of 2013, with a proposed operational life of two years for treatment. Samples and data will be collected quarterly to determine the operational effectiveness of treatment. |
Peter Campbell |
| 5/29/2013 |
Cleanup Plan Approved |
In well treatment work plan approved. |
Peter Campbell |
| 1/27/2014 |
Update or Other Action |
Bob Witsell from General Electric (GE) Environmental called today to inform our office that the URS remediation plan has been shelved. GE has retained Arcadis to review the project file and make recommendations for the property. |
Peter Campbell |
| 3/24/2014 |
Update or Other Action |
Jen Parker EPA Injection well program pointed out that the 1998 Dames and Moore Cesspool Abandonment report notes that a 4” steel pipe connected the old cesspools (flood drain and septic) that were eight feet apart. The floor drain cesspool has been assessed, but the septic cesspool may not have been assessed. The EPA is recommending that additional assessment be conducted on the septic cesspool prior to conducting remediation activities.
|
Peter Campbell |
| 3/24/2014 |
Document, Report, or Work plan Review - other |
Reviewed the 2011 Groundwater Characterization Report, Former TBE Machine Shop Property, dated December 9, 2011, prepared by URS Alaska. Monitoring well MW-11 was installed on July 18, 2011. It was installed near the east property boundary to assess the down-gradient conditions. Soil and groundwater samples collected from this well did not detect any contaminations exceeding ADEC soil or groundwater cleanup levels. Following the installation of MW-11, a comprehensive land survey of all the monitoring wells were performed by Integrity Surveys on July 18, 2011. The depth to groundwater on July 18, 2011 ranged from 44.57 to 47.19 feet below top of casing in MW-1 through MW-10, and on July 20, 2011 the depth to groundwater in MW-11 was 43.60 feet below top of casing. Groundwater was found to be flowing towards the southeast at a gradient of 0.00036. Groundwater samples were collected from all monitoring wells at the site (MW-1 through MW-11) on July 18 through 20, 2011. Sample results detected TCE at 0.0050 to 0.024 mg/L, PCE at 0.014 to 0.24 mg/L, ethylbenzene at 1.9 mg/L, GRO at 13 mg/L and DRO at 8.7 mg/L. The calculated hydraulic conductivity (K) values by the Hvorslev slug test method performed ranged from 42.5 feet per day in MW-1, to 12.9 feet per day in MW-2. The calculated K values by the Bower and Rice slug test method performed ranged from 24.6 feet per day in MW-1 to 7.06 feet per day in MW-2. Based on the current and historical sample results the contamination appears to be within the property boundary. |
Alyce Hughey |
| 8/18/2014 |
Document, Report, or Work plan Review - other |
Reviewed ATR Post-System Startup Report, Former TBE Machine Shop Property. Report documents the installation of the ART remediation system, pre-operation sampling and post startup sampling. |
Peter Campbell |
| 5/22/2015 |
Document, Report, or Work plan Review - other |
Review work plan for the assessment of a former log crib. Ten soil boings are to be drilled in the area of the crib to asses soil quality. |
Peter Campbell |
| 4/7/2016 |
Meeting or Teleconference Held |
Phone call with consultant and representative of General Electric to discuss the status of the septic system closure. GE will abandon septic system and cesspool, which is impacted with chlorinated solvents, in compliance with EPA Class V Injection Well rules. The remediation air sparge system will be shut down this summer to determine if there will be any rebound in levels of ground water contaminants. The system is to be mothballed over the winter. |
Peter Campbell |
| 7/18/2016 |
Update or Other Action |
EPA issued approval for Closure Plan for One Motor Vehicle Waste Disposal Well. |
Peter Campbell |
| 7/21/2017 |
Update or Other Action |
EPA issued a conditional closure letter for the Motor Vehicle Waste Disposal Well. This only involves the removal of the disposal equipment and associated tanks as regulated by the EPA. the March 2017 report indicated that no residual soils contamination remained under the septic tank or wood crib. |
Peter Campbell |
| 1/29/2020 |
Document, Report, or Work plan Review - other |
Review the 2019 Fourth Annual Monitoring Report. No evidence of significant rebound from the remediation system shutdown. GE proposes to continue monitoring through 2020. Concentrations appear to be in decline with aerobic and anaerobic attenuation. |
Peter Campbell |
| 10/27/2021 |
Document, Report, or Work plan Review - other |
Routine groundwater monitoring has been conducted on site since the shutdown of the ART system in June 2016. Results have remained consistent with historical data and annual monitoring is proposed for 2021.
No evidence of significant rebound was observed during the 2020 post-ART system shutdown monitoring period. However, sample 2020 integrity was compromised due to samples being analyzed out of temperature range and outside of hold time, resulting in detected results being J-flagged, and non-detected results being rejected. The 2020 data are presented in this report for documentation purposes.
The ART system wells did not reduce concentrations of contaminants to below standards over the course of their operation. While the ART system operation may have provided some benefit, it is unclear what the contribution of the ART system was to the overall improvement in groundwater concentrations of PCE and TCE. The formation of cis-DCE is indicative of anaerobic degradation of PCE and TCE; something which would not be expected to be enhanced, but rather hindered by, the ART system. At the present time, remaining chlorinated VOC is cis-DCE, which is amenable to both aerobic and anaerobic biodegradation. As the site conditions are amenable to cis-DCE formation, it is recommended that nothing be done to interfere with anaerobic reductive chlorination processes. All of the remaining constituents are amenable to non-biological attenuation mechanisms. Given the current concentrations and types of VOCs that now predominate, conditions are well suited to monitored natural attenuation as the sole remedy going forward.
|
Peter Campbell |
| 4/6/2022 |
Document, Report, or Work plan Review - other |
Review 2021 sampling report. Monitoring well sampling indicates a general diminishing concentration of contaminants. The consultant has recommended sampling wells bi-annually, and ADEC agrees. The next groundwater sampling event will be in 2023. |
Peter Campbell |
| 4/2/2024 |
Long Term Monitoring Workplan or Report Review |
Biennial groundwater monitoring was conducted on August 1, 2023
Eight VOCs have historically been detected in one or more of the remaining monitoring wells (MW-1, MW-2, MW-4, MW-5, and MW-7) at concentrations above groundwater cleanup levels: 1,2,4-trimethylbenzene, cis-1,2-dichloroethene (cis-1,2-DCE), ethylbenzene, naphthalene, tetrachloroethene (PCE), trichloroethene (TCE), vinyl chloride, and total xylenes. Of these VOCs, only four were detected at concentrations above cleanup levels in samples collected in 2023. Monitoring wells MW-5 and MW-7 had no VOC detections in 2023. Constituent concentrations at most wells remain below or within one order of magnitude of the groundwater cleanup levels. The TCE concentration level observed in monitoring well MW-4 is consistent with historical observations. Concentrations of most contaminants have decreased over time or remained at low concentrations. While conditions have improved, a number of constituents remain above cleanup levels, primarily in wells MW-1 and MW-2. Groundwater quality in MW-1 and MW-2 vary over time but there is still an overall decreasing trend in COC concentrations.
|
Peter Campbell |
