| Action Date |
Action |
Description |
DEC Staff |
| 10/2/1991 |
Site Added to Database |
Site Added to the Database. |
Robert Weimer |
| 6/2/1992 |
Site Characterization Report Approved |
Terrasat performed site characterization of Greer property in response to contamination being identified on the adjacent property (United Building Supply) which included six soil borings and five monitoring wells during November 1991. Reviewed a Terrasat "Site Characterization (Phase II), Greer Tank Facility" report dated May 1992. Methylene chloride and tetrachloroethene (PCE) were identified in soil and groundwater. Analytical soil sampling results detected methylene chloride in all borings ranging from 0.012 mg/kg at 2.5' bgs in Boring SB-01 to 68.0 mg/kg at 2.5' bgs in Boring SB-04, and PCE in all borings ranging from 0.017 mg/kg at 2.5' bgs in Boring SB-01 to 80.0 mg/kg in Boring SB-04. The 18 AAC 75.341 Method 2 cleanup level for methylene chloride (dichloromethane) is 0.016 mg/kg and for PCE is 0.024 mg/kg. Analytical groundwater sampling results detected methylene chloride in monitoring wells MW-101, MW-102, MW-103, MW-104, MW-105 and MW-4 ranging from 0.007 mg/l in MW-101 to 0.13 mg/l in MW-4, and (PCE) in monitoring wells MW-102, MW-104, MW-105 and MW-4 ranging from 0.048 mg/l in MW-105 to 0.4 mg/l in MW-4. The 18 AAC 75.345 Table C cleanup level for methylene chloride and for PCE is 0.005 mg/l. It is recommended that a corrective action plan be developed to address remediation of PCE in the soils and groundwater in the vicinity of the Greer Tank Facility. The report was reviewed on 10/16/08 but placed at this point in time to maintain chronological order. |
Jim Frechione |
| 12/3/1992 |
Site Characterization Workplan Approved |
Reviewed a copy of the Terrasat "Project Work Plan, Remedial Investigation, and Remedial Design at Greer Tank Facility" dated 9/18/92 submitted to the ADEC on 11/6/92 for in-situ treatment of contamination. They proposed biotreatment of soil and air sparge for groundwater. Monitoring well installation can proceed as planned. Other comments are being prepared on other technical aspects of the plan by other staff and will be sent to your office when complete. |
Scott Bailey |
| 12/11/1992 |
Site Characterization Workplan Approved |
Comments from Kevin Kleweno on the Terrasat "Project Work Plan, Remedial Investigation, and Remedial Design at Greer Tank Facility" dated 9/18/92, submitted a copy to the ADEC on 11/6/92 for in-situ treatment of contamination, were sent to Greer Tank. Comments include:
1) A determination as to the quality of purge water must be made before determining the disposal method.
2) A report based on the bioremediation bench tests needs to be submitted to the ADEC for review and approval prior to attempting any site remediation.
3) The proposed bench test appears to be temperature dependent. The lowest and highest temperature soils expected are the base temperatures the department requires in developing reaction kinectics model.
4) If an air stipping tower is used for treatment, an engineering plan review needs to be completed.
5) Please provide the data on the location and test equipment that will be used to conduct the bench testing.
6) What testing is planned to ascertain whether vinyl chloride, a Class A carcinogen that is a stable end product of bioremediated halogenated volatile organics, is present in the bench scale.
7) Interim reports are requested for department review within one week after issue to the responsible party.
8) The chlorinated solvent soil bioremediation must meet the requirements outlined in Section VI of the "Guidance for Storage, Remediation and Disposal of Non-UST Petroleum Contaminated Soils" dated 7/29/91. |
Scott Bailey |
| 3/15/1993 |
Leaking Underground Storage Tank Corrective Action Underway |
LUST Corrective Action Underway this date. |
Former Staff |
| 5/28/1993 |
Site Characterization Workplan Approved |
A letter of no objection was sent to Terrasat in response to review of the "Greer Tank Remedial Design Investigation Proposal for Slug Testing Monitoring Wells at Former United Lumber Company Property". A report of findings was requested in the letter. |
Kevin Kleweno |
| 7/31/1993 |
Site Characterization Report Approved |
Reviewed the Terrasat "Release Investigation; Greer Tank Facility; 2921 West International Airport Road; Anchorage, Alaska" dated July 1993. The report further characterized the soil and groundwater at the site. Four vapor extraction (V1 through V4) and monitoring well borings (MW-106 through MW-115) were drilled and sampled on 12/7-10/92. Analytical results for soil samples indicated that cleanup levels were exceeded for: Tetrachloroethene (PCE) up to 170 mg/kg in Borings V4, MW-108, MW-110, MW-111, MW-114, and MW-115; 1,1-Dichloroethene up to 3.3 mg/kg in Borings V4, MW-108, MW-110, and MW-111; Methylene Chloride up to 5.8 mg/kg in Borings MW-106, MW-108, MW-110, and MW-111; Trichloroethene (TCE) up to 0.048 mg/kg in Boring MW-110; and, 1,1,2-Trichloroethane at 0.024 mg/kg in Boring MW-106. Groundwater sampling results indicated that the only contaminant that was above cleanup levels was PCE up to 0.28 in MW-4, MW-104, MW-105, MW-106, MW-109, and MW-111. The report concludes that groundwater was mounded near the PCE source area; the groundwater gradient is relatively flat; and contamination would not have spread more than 100 feet. The report recommended a design for soil and groundwater treatment. |
Jim Frechione |
| 8/1/1993 |
Document, Report, or Work plan Review - other |
Reviewed the HartCrowser "Treatability Study for PCE Impacted Soils; Anchorage, Alaska" at the Greer site, dated August 1993. Bioremediation and SVE are the recommended treatment alternatives. |
Ray Dronenburg |
| 9/27/1993 |
Update or Other Action |
In a Terrasat document "Request for Approval of Long-Term Groundwater Monitoring Instead of Groundwater Treatment at Greer Tank, Inc., Anchorage, Alaska" dated 9/27/93, an alternative plan was requested pave over the contaminated area and conduct long-term groundwater monitoring. |
Ray Dronenburg |
| 10/14/1993 |
Interim Removal Action Approved |
Soil Vapor Extraction set up - run for three years until point of diminishing returns. |
Ray Dronenburg |
| 11/4/1993 |
Document, Report, or Work plan Review - other |
Reviewed the Terrasat report "Soil Vapor Extraction Test - Greer Tank" dated 11/4/93. The report concluded SVE was effective in removing PCE from the site. |
Ray Dronenburg |
| 11/5/1993 |
Document, Report, or Work plan Review - other |
ADEC reviewed the Terrasat document "Request for Approval of Long-Term Groundwater Monitoring Instead of Groundwater Treatment at Greer Tank, Inc., Anchorage, Alaska" dated 9/27/93, an alternative plan was requested pave over the contaminated area and conduct long-term groundwater monitoring. A letter was sent this date that did not approve the request. |
Kevin Kleweno |
| 8/12/1994 |
Update or Other Action |
Reviewed the Dowl Engineers "Greer Tank PCE Release - Vadose Zone Remediation, 91-211-266-2, File No. CS/L 55.129" dated 8/10/94, and received by the CSP on 8/11/94. Dowl is the new consultant for Greer site and they sent this letter to ADEC regarding operation and maintenance of SVE system that had been installed. Permission was granted to remove the granulated activated carbon (GAC) filter from the system and exhaust directly to the atmosphere. There is no record in the file that installation and operation of the SVE was ever approved by the department, however. |
Eileen Olson |
| 12/20/1994 |
Document, Report, or Work plan Review - other |
Reviewed the Dowl Engineers report to Alaska National Insurance "Soil Vapor Extraction System - Operation and Monitoring; July 25, 1994 through November 15, 1994; Greer Tank Facility, Anchorage, Alaska" dated 11/22/94 regarding SVE system effectiveness and possible need to shutdown during winter months. The concentration of the soil vapor removed from the vadose zone from startup to 8/30/94 ranged from approximately 21.5 ppm to approximately 27 ppm. After 8/30 the PCE concentration showed a decreased which was anticipated, probably due to removal of the initial pore volume of PCE contaminated air in the subsurface. The late period of the test shows a gentle increase in PCE concentration for an unknown reason but speculated to be the results of the freezing of upper soils changing the preferential air flow pathways in the subsurface. The total calculated mass of PCE removed from the vadose zone from 7/25 to 11/15/94 id 40.2 pounds. In their December 23, 1993 report, Terrasat indicated that an estimated 55 pounds of PCE existed in the vadose zone prior to operation of the SVE system and as of the date of that report Terrasat indicated that approximately 24 pounds had been removed. Thus, an estimated total of 64 pounds of PCE has been estimated to have been removed. The report recommended SVE system operation through the winter if current removal rates continue. Otherwise, it would be recommended to shut down the system until Spring 1995. Dowl recommended a groundwater monitoring program be initiated at this time, collecting samples from the well showing the highest PCE concentration in past sampling, selected wells within the plume, and selected existing wells around the perimeter of the plume. |
Ray Dronenburg |
| 6/9/1995 |
Update or Other Action |
The department received a letter from Dowl, "Greer Tank Facility PCE Release Site; ADEC Contaminated Site Number 912112662; ADEC File Number CS/L 55.129", dated 6/8/95 to ADEC requesting to re-start SVE system and conduct groundwater monitoring. |
Eileen Olson |
| 2/8/1996 |
Document, Report, or Work plan Review - other |
Reviewed a copy of the Dowl "Remedial Action Report - 1995; Greer Tank Facility PCE Remediation and Ground Water Monitoring; Anchorage, Alaska" dated December 1995 and received by the department on 2/8/96. The SVE is effective in removing PCE from soil. PCE remaining in the subsurface probably can still be removed by the SVE and the point of diminishing returns has not yet been reached. An estimated 29-39 pounds of PCE was removed by the SVE operation between 6/15/95 and 11/1/95 bringing the total PCE removed by the SVE system to between 93 and 103 pounds. The SVE system remains in operation at the time of the report but it is recommended to be turned off when freeze-up problems start occurring and restarted in the spring.
Groundwater monitoring detected: PCE above cleanup levels in monitoring wells MW-4, MW-104, MW-105, and MW-106; TCE, 1,1,1-Trichloroethane, 1,1-Dichloroethylene, and cis-1,2-Dichloroethylene were detected in at least one monitoring well for each contaminant but below cleanup levels.
Three air samples results taken at the offgas stack on three separate occasions for PCE, TCE, and 1,3-diclorobenzene did not result in exceedances of outdoor air cleanup values.
The report recommended natural attenuation with long term monitoring, risk assessment, or air sparge, with the risk assessment as the preferred recommendation.
|
Ray Dronenburg |
| 2/9/1996 |
Update or Other Action |
The ADEC sent a letter to the Alaska National Insurance regarding concerns about management of the site to date and the need to address possible off-site migration of contaminants. |
Ray Dronenburg |
| 2/23/1996 |
Update or Other Action |
In response to the department's 2/9/96 letter, an Alaska National Insurance letter dated 2/23/96 was received by the ADEC on 2/26/96 regarding concerns about remedial actions to date and disputing the possible impacts to the National Guard Armory site from Greer Tank. The letter indicated that the department was aware of the operation of the SVE system and it was approved by the ADEC personnel assigned to the site. However, the ADEC notes that there is no documentation in the file to support this approval. The letter goes on to state that at this time there is no evidence to support the possibility that PCE from Greer Tank is impacting the Armory site. |
Ray Dronenburg |
| 4/5/1996 |
Update or Other Action |
Reviewed a Dowl letter to the Alaska National Insurance Company "Contaminant Migration Modeling Results, Greer Tank Site, 2921 West International Airport Road, Anchorage, Alaska", dated 4/5/96, regarding the results of a model exercise to estimate potential for contaminant migration. The results indicated that a maximum concentration of 2.35 ppb reached the receptor well 45 years from the time of the instantaneous spill and then decreased. The 18 AAC 75.345 Table C cleanup level for PCE in groundwater is 5 ppb. However, additional modeling indicated a continuous release of PCE to groundwater from the vadose zone would increase the concentration of PCE reaching the receptor well. These results support continued source removal by SVE and potential capping of the release area with asphalt. Dowl recommended doing a risk assessment and possible ACLs for the Greer site. |
Ray Dronenburg |
| 6/12/1996 |
Update or Other Action |
Reviewed the Dames and Moore "Limited Phase II Investigation; Former United Building Supply Company; 5011 Jewel Lake Road; Anchorage, Alaska; D&M No. 31494-011-195" assessment report dated 4/10/96 and received 6/12/96. The report concluded that there was no evidence of PCE impacts to groundwater at the UBS site. The department notes that no analytical report for the results for the groundwater sample from MW-7 was included with the report to corroborate the findings stated in the report text. Sent a letter this date to Dowl Engineers indicating that the ADEC does not require any further analysis work at this time at MW-6, MW-7, or DMW-1. The ADEC notes that the address of the property that was the subject of the report was 4901 Spenard Road, not 5011 Jewel Lake Road. It appears that the property that the Former United Lumber Supply occupied was subdivided into two properties. 4901 Spenard Road is one property removed from the Greer Property. |
Ray Dronenburg |
| 6/21/1996 |
Update or Other Action |
The department received a letter from Dowl Engineers "Greer Tank Facility, 2921 W. International Airport Road, Anchorage, Alaska; ADEC Spill Number 91-2-1-266-2, File CS/L 55.129; Proposed 1996 Scope of Work" dated 6/12/96 regarding the SVE and proposal to do a risk assessment and possible Alternate Cleanup Levels. They requested a scoping meeting. |
Ray Burger |
| 8/1/1996 |
Update or Other Action |
The department received the Dowl Engineers "Conceptual Site Model; Greer Tank Facility, 2921 W. International Airport Road, Anchorage, Alaska; ADEC Spill Number 91-2-1-266-2, File CS/L 55.129" dated 7/31/1996. |
Ray Burger |
| 9/11/1996 |
Document, Report, or Work plan Review - other |
Received a copy of the Dowl Engineers "Soil Cuttings Sample Results; Greer Tank Facility, 2921 W. International Airport Road, Anchorage, Alaska; ADEC Spill Number 91-2-1-266-2, File CS/L 55.129" dated 9/3/1996. The two soil samples were analyzed for halogenated volatile organics and the PQL for the Soil Bag #1 sample was 0.0407 mg/kg and the PQL for the soil stockpile sample was 0.0393 mg/kg. Both PQLs were above the PCE and TCE migration to groundwater cleanup level of 0.005 mg/kg which is the default value for soil. |
Ray Burger |
| 6/20/1997 |
Update or Other Action |
Reviewed a copy of the Dowl letter "Greer Tank Facility PCE Remediation - Soil Vapor Extraction; 2921 W. International Airport Road, Anchorage, Alaska; ADEC Spill Number 91-2-1-266-2, File CS/L 55.129" dated 6/19/1997, received this date at the ADEC, recommending decommissioning of the SVE system because it is no longer extracting PCE at levels to justify its operation. ADEC approved of the decommissioning process. |
Ray Burger |
| 8/6/1997 |
Offsite Soil or Groundwater Disposal Approved |
Reviewed a Dowl "ADEC Approval of IDW Disposal Through Alaska Pollution Control; Greer Tank PCE Remediation, 2921 W. International Airport Road, Anchorage, Alaska; ADEC Spill Number 91-2-1-266-2, File CS/L 55.129" dated 7/31/97 and received by the department on 8/4/97. Conditionally approved the transport for disposal of approximately 24, 55-gallon drums (estimated 980 gallons) of potentially PCE-contaminated monitoring well purge water, well development water, and water collected during a pump test at the site. The condition was submittal of manifests to the ADEC upon project completion. |
Ray Burger |
| 5/18/2001 |
Update or Other Action |
A letter was sent from the Contaminated Sites Program (CSP) this date to Greer Tank indicating that there has been no subsequent work reported to the CSP after a Conceptual Site Model was submitted to the CSP on 8/01/96. The letter requested that Greer contact the CSP in order to determine the current environmental site status as there are outstanding environmental issues that still need to be addressed. |
Jim Frechione |
| 1/22/2002 |
Update or Other Action |
A letter was sent to a neighboring, and presumed upgradient, property owner (Gene Effler) stating that the ADEC does not believe that the Greer contamination is migrating towards his property. |
Jim Frechione |
| 1/23/2002 |
Update or Other Action |
A letter was sent this date to Greer (Helms) requesting a site update by 22 February 02. Lynne Bush is the newly assigned Project Manager for this site. |
Lynne Bush |
| 2/19/2002 |
Update or Other Action |
Received the Dowl correspondence "Request for Update and Site Characterization Greer Tank Facility; 2921 West International Airport Road, Anchorage; File #CS55.129, Reckey #91 21 01 259 01" dated 2/9/02. The documentation includes reports previously requested by the Department and a transmittal letter. |
Lynne Bush |
| 2/6/2004 |
Update or Other Action |
The file number was changed from CS55.129 to 2100.38.369. |
Sarah Cunningham |
| 3/30/2007 |
Update or Other Action |
Staff reassigned from Sundet to Petrik. |
Aggie Blandford |
| 5/21/2008 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed. |
Bill Petrik |
| 10/23/2008 |
Exposure Tracking Model Ranking |
Updated the Initial Ranking with ETM completed for source area id: 72183 name: PCE Spill. |
Bill Petrik |
| 12/24/2008 |
Update or Other Action |
The Contaminated Sites Program (CSP) completed review of the files for Greer Tank Yard – PCE and Greer Tank Yard – USTs and subsequently sent a letter summarizing the site history and requested further soil and ground water sampling and characterization and direction on potential closure for two regulated underground storage tanks (USTs) that were removed. |
Bill Petrik |
| 2/18/2009 |
Meeting or Teleconference Held |
Sundet met with David Clark counsel for Greer Tanks, Dick Waller counsel for Alaska National Insurance, and Cory Loyd and Brandie Hofmeister of Dowl Engineers at Dowl to discuss DEC's 12/24/08 letter. Loyd proposed that Dowl respond in writing that it needed to perform a site reconnaissance prior to submitting a workplan to sample the monitoring wells. A reconnaissance is required because it is unknown as to the status of the monitoring wells some of which are on the down gradient property. Dowl's response will include a time line to perform the work. Further work would be based upon the findings. DEC had no objection to this approach. Waller and Clark noted that there is an agreement between Greer and its insurance carrier Alaska National Insurance that it would address the solvent releases, therefore the request that correspondence be sent to Waller and copy Clark. |
Rich Sundet |
| 3/4/2009 |
Update or Other Action |
On 3/4/09, DEC responded to a 2/27/09 submittal by Dick Waller counsel for Greer Tanks to Bill Petrik of the Contaminated Sites Program. In Waller's submittal, he proposed that a site reconnaissance occur in spring 2009 to inspect the status of the site's monitoring wells. Based on that inspection, a work plan would be submitted to DEC for its review and approval for one groundwater monitoring event. In its letter, DEC noted that it had no objection to this approach but that based upon the findings, DEC may request further action. |
Rich Sundet |
| 9/10/2009 |
Site Characterization Workplan Approved |
After review of copies of the Dowl HKM "Greer Tank Facility Groundwater Monitoring Well Sampling and Analysis Plan" dated and received 8/25/09 and its revision dated and received 8/27/09, the Contaminated Sites Program (CSP) sent a letter to the responsible party’s counsels and consultant conditionally approving the work plan. The work plan calls for groundwater sampling of five monitoring wells that remain on site and on the adjacent property to which contamination has migrated. Some wells are caved, destroyed, or inaccessible since the last monitoring event in 1995. The work plan calls for maintenance, redevelopment, surveying, static water level measurement, and sampling of the remaining monitoring wells. EPA Method 8260C will be used as the sampling protocol for VOCs. The approval letter also reminded the recipients that a blind sample should be submitted from the monitoring well with the potentially highest level of contamination based on historical results. The letter also indicated that the CSM graphic and scoping forms need to be submitted and the narrative updated if conditions have changes since the last CSM was submitted in 1996. |
Bill Petrik |
| 10/12/2009 |
Update or Other Action |
Read an email from Joe Christopher of Dowl dated 10/8/09 indicating that Dowl received the results of recent investigation and are in the process of analyzing the data and putting together the report and wondered what type of notification does DEC require prior to authorizing the removal of the drums of decon/purge water from the site. Called and talked to Joe via phone regarding the situation indicating that the ADEC needs a copy of the water sampling results for review to determine whether there were any detections of chlorinated solvents. If there were detections of chlorinated solvents then the waste must be processed as a Designated F002 RCRA Waste. |
Bill Petrik |
| 6/7/2010 |
Document, Report, or Work plan Review - other |
Reviewed the Dowl HKM "Greer Tank September 2009 Groundwater Sampling and Analysis Event" dated 11/24/09 and received 4/5/10. The report documents tasks associated with the inspection, maintenance, preparation of, and sampling of onsite GW monitoring wells (MWs) MW-2, MW-3, MW-4, MW-105, and MW-106.
Frost-heave damage to MWs MW-3, MW-105, and MW-106 was repaired and these wells were professionally surveyed. MW-2 was observed to be filled with bentonite and was previously decommissioned. Numerous other wells exist on the site and adjacent property but were not a part of this work. Other MWs determined inaccessible or damaged and unable to be sampled were MW-101, MW-102, MW-103, MW-107, MW-110, MW-111, MW-113, MW-114, and MW-115 and designated such on Figure 2 of the report.
The wells were observed to have copious amounts of fine silt deposits within the screened interval prior to sampling because the last GW sampling event at the site was in 1995. The static water levels in MWs MW-3, MW-4, MW-105, and MW-106 were measured on and varied between 8.5 feet and 8.95 feet bgs. The resulting data was used to calculate a relatively flat local GW gradient to the west-southwest at 0.00075 feet/foot. A more northwesterly flow direction was calculated from previous measuring events.
The 4monitoring wells were sampled for VOCs. MW-3 was ND for all target analytes. Tetrachloroethylene (PCE) was detected above its 18 AAC 75.345 Table C cleanup level of 0.005 mg/l in wells MW-4, MW-105, and MW-106 at concentrations of 0.165 mg/l, 0.0525 mg/l, and 0.106 mg/l, respectively. Trichloroethylene (TCE) was detected in MW-105 and MW-106 at concentrations of 0.00102 mg/l, and 0.0222 mg/l, respectively. The concentration of TCE in MW-105 is below its cleanup level of 0.005 mg/l but the reported TCE concentration in MW-106 is above it. Cis-1,2-Dichloroethene (Cis-1,2-DCE) was detected in MW-105 at 0.0184 mg/l and in MW-106 at 0.0152 mg/l. Both of these concentrations are below the DEC cleanup level of 0.070 mg/l. There was no detection of methylene chloride or vinyl chloride in any of the four MWs. The plume extent is still undefined in directions other than SW.
Emerald Alaska was contracted to remove the IDW water from the property.
Natural attenuation of PCE was demonstrated by the presence of TCE and 1,2 cis-DCE in GW but contamination remains well above cleanup levels in groundwater and past soil data from the 1990s show probable concentrations above ingestion health levels. The levels of PCE contamination in MW-4, MW-105, and MW-106 since groundwater monitoring began in 1990 or 1991 and SVE system operation shows no obvious stabilization or trend. The latest laboratory analytical results indicates that the PCE concentrations in MW-4 is more than twice the 1995 level and these wells remains at 35 times the cleanup level in MW-4, 10 times the cleanup level in MW-105, and 20 times the cleanup level in MW-106. 1992 analytical soil sampling results were up to 200 milligrams-per-kilogram (mg/kg) in Boring V4 at 4 feet bgs.
This project lacks documentation of the degradation of PCE and simple attenuation and biodegradation elements such as oxygen levels and oxidation-reduction potential (ORP) to determine the status of the plume, i.e. aerobic or anaerobic. Comparison of recent GW data for PCE and older 1990 soil data indicates that there may be a health concern from contamination through the indoor and outdoor air pathway. The commercial target indoor air vapor intrusion contaminant concentration level in GW for PCE is 0.029 mg/l. This value is exceeded by up to over five times based on the latest GW analytical results. In addition, the Terrasat 1993 report showing a PCE soil result of 200 mg/kg greatly exceeds the outdoor air inhalation regulatory level of 10 mg/kg. To assist in evaluating the vapor intrusion pathway for the Greer Tank Building and the structure north of this on the adjacent property, completion of an ADEC Building Survey and Indoor Air Sampling Questionnaire was requested.
Shortcomings with the Laboratory Data Review Checklist and CSM were sited and requested to be improved or corrected.
A work plan for further site characterization to determine the extent of the plume was requested. Upon completion of the site characterization activities requested in a work plan and subsequent report, a written work plan to the CSP for review was requested for future corrective action at the site, including a schedule.
|
Bill Petrik |
| 6/17/2010 |
Meeting or Teleconference Held |
A meeting was held this date at the Dowl Offices in Anchorage. In attendance was:
Bill Petrik/ADEC/CSP;
Rich Sundet/ADEC/CSP;
Joe Christopher/ Dowl HKM;
Corey Loyd/ Dowl HKM;
David Clark/Attorney;
Dick Waller/Attorney.
Meeting Highlights:
Discussed methylene chloride and why it might exist at the site.
Discussed COCs – PCE, VC, and methylene chloride.
Mr. Christopher provided a graph of the PCE concentrations in MW-4 from the initial site investigation to present which depicted an overall downtrend in the contaminant level.
Mr. Waller raised the issue on the National Guard (NG) site. Mr. Loyd brought to light a statement in a Shannon & Wilson report on the NG site that stated groundwater flowed to the east but recognized that because of Lake Spenard ~500’ to the west that seasonal change in this direction is likely. Mr. Loyd also noted that Dowl did a study and concluded that because of the 14’ utility corridor down the middle of Spenard Road in the vicinity of the NG site and Greer Tank, that whatever happened on the Greer Property is not connected with the NG property and vice versa.
Mr. Waller raised the question of why further investigation outward from the latest area investigated has to occur.
The issue of vapor intrusion was raised by Mssrs. Clark and Waller and the need and degree to which the ADEC Building Survey and Indoor Air Sampling Questionnaire form needs to be completed. |
Bill Petrik |
| 11/4/2010 |
Document, Report, or Work plan Review - other |
Reviewed a copy of the Dowl "Groundwater Monitoring, Well Sampling, and Analysis Work Plan" dated November 2010, received 11/3/10. The work plan calls for sampling MWs MW-3, MW-4, MW-105, MW-106, MW-109, MW-112, and MW-113 and submitting them for laboratory analysis of VOCs. The work plan also proposed measuring static water levels, DO, ORP, pH, and specific conductance in each well. An approval letter was mailed this date with minor conditions added to the work plan. |
Bill Petrik |
| 9/1/2011 |
Document, Report, or Work plan Review - other |
Reviewed June 2011 Groundwater Monitoring Report. Samples were collected from wells MW-4, MW-105, MW-106, MW-109, and MW-113 and analyzed for VOCs. PCE was detected in each of the wells above ADEC Table C cleanup levels except MW-113. PCE concentrations ranged from 0.0228 mg/l to 0.108 mg/l. TCE and cis-1,2-DCE were also detected in several wells, but at concentrations below Table C cleanup levels. |
Bill O'Connell |
| 10/6/2011 |
Meeting or Teleconference Held |
Meeting today with DOWL and attorney for Greer Tank. Modeling is proposed as a means to evaluate the vapor intrusion pathway. The extent of the PCE plume in groundwater appears to have been defined during previous investigations and a review of historical data indicate a downward trend in PCE concentration in the most impacted wells. |
Bill O'Connell |
| 10/31/2012 |
Exposure Tracking Model Ranking |
A new updated ranking with ETM has been completed for source area 72183 PCE Spill. |
Katrina Chambon |
| 4/12/2013 |
Meeting or Teleconference Held |
Meeting with consultant to discuss vapor intrusion as a complete pathway. CSP requested a Work Plan for a vapor intrusion pathway and requested that all groundwater monitoring wells be sampled. |
Katrina Chambon |
| 7/2/2013 |
Meeting or Teleconference Held |
Meeting with consultants to discuss vapor intrusion work plan. |
Katrina Chambon |
| 7/2/2013 |
Meeting or Teleconference Held |
Meeting with consultants and CSP staff to discuss vapor intrusion work plan. CSP suggested sub slab sampling; however, consultant is going with indoor air sampling. CSP will reevalute vapor intrusion pathway after indoor air sampling. |
Katrina Chambon |
| 7/19/2013 |
Site Characterization Workplan Approved |
The work plan proposes perform groundwater sampling and indoor air sampling. This work plan is approved with the following conditions:
1.CSP requests that the sampling method is consistent i.e. use either the Summa canister or the passive diffusion adsorbent cartridge. If the passive diffusion adsorbent cartridge is used, CSP requests documentation indicating that the laboratory will meet DEC’s date quality objectives for indoor air (i.e. laboratory method detection limits will be less than DEC’s residential indoor air target levels for all contaminants of conern).
2.CSP requests that at least three samples and one duplicate are collected from the Stanley Automotive building and the Greer Tank building.
3.CSP request that a duplicate sample be collected in accordance to DEC’s Draft Field Sampling Guidance, dated May 2010
4.Complete copies of field notes need to be provided with the report. Please note that CSP does not accept electronic copies or CDs. Laboratory data will be accepted on a CD, if the report is more than 200 pages. Hard copies shall be delivered or mailed to the DEC office.
5.Please provide three (3) working days advance notice when planning to do work, to give us an opportunity to be on site to inspect.
|
Katrina Chambon |
| 9/10/2013 |
Site Characterization Workplan Approved |
Work Plan addendum is approved. Plan proposes to install two groundwater monitoring wells and conduct additional indoor air sampling. The indoor air sampling will consist of using three 3-week passive diffusion sampling. |
Katrina Chambon |
| 11/26/2013 |
Offsite Soil or Groundwater Disposal Approved |
|
Katrina Chambon |
| 12/12/2013 |
Document, Report, or Work plan Review - other |
CSP received Groundwater/Vapor Intrusion Analysis Report, Greer Tank Facility 2921 West International Airport Road Anchorage, AK dated November 29, 2013. Seven groundwater monitoring wells exceeded PCE cleanup levels. The highest PCE concentrations was 0.134 mg/L. CSP has the following comments regarding the report.
1. Your consultant failed to mention in the report that the analytical soil sample from borehole DC-1, had a detection of tetrachloroethane above migration to groundwater cleanup levels with a concentration of 0.0438 mg/L. Your consultant failed to mention where the soil sample was collected and from what depth. The chain of custody associated with DC-1 states that the soil sample was collected at 11:30 am on October 14, 2013; however, if the soil sample was collected during the installation of MW-120 why was the water sample collected before the soil sample, on the same day? Please have your consultant clarify the discrepancy.
2. CSP concurs with your consultant that further evaluation of vapor intrusion is warranted. CSP does not agree with your consultants comment on the last paragraph on page 21 section 5.2 of the report. Concentrations of contaminants in outdoor air may not be subtracted from indoor air concentrations.
3. The Contaminated Sites Program regulates the vapor intrusion pathway from contaminated soil or groundwater to indoor air. Unless soil-gas or sub-slab sampling is conducted, CSP can only assume that the current exceedance is due to vapor intrusion from contaminated soil or groundwater. CSP strongly suggests the collection of sub-slab or soil-gas samples to further evaluate this pathway, otherwise, CSP will require mitigation of this exposure pathway regardless of the source.
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Katrina Chambon |
| 1/31/2014 |
Site Characterization Workplan Approved |
The work plan proposes to collect two sub-slab soil gas samples, plus one duplicate from the Stanley Automotive building, one outdoor air sample, and three indoor air samples, and one duplicate from each building. |
Katrina Chambon |
| 2/14/2014 |
Site Visit |
Site visit to observe sub-slab soil gas sampling. |
Katrina Chambon |
| 4/9/2014 |
Update or Other Action |
The Contaminated Sites Program (CSP), has completed its review of the Vapor Intrusion Evaluation Report for the Greer Tank Facility. The Report contains the results of the vapor intrusion monitoring conducted at the Stanley Motors and Greer Tank properties. The report indicates that tetrachlorethene (PCE) concentrations were up to 170 µg/m3 at the South wall of the Stanley Shop building, which is below the target level of 1800 µg/m3 .
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Katrina Chambon |
| 7/11/2014 |
Document, Report, or Work plan Review - other |
Reviewed Additional Site Investigation Work Plan for Greer Tank. The objectives of the site investigation are to delineate the extent of contamination in soil and collect information that will be used to develop remedial strategies. Activities planned for the site include a ground penetrating radar survey, advancement and sampling of soil borings, field screening using Color-Tec, and an evaluation of the presence of a suspected perched aquifer. The number of borings will be determined in the field. Information collected during the investigation will be used to draft a feasibility study to address PCE and breakdown products at the site. |
Bill O'Connell |
| 3/5/2015 |
Site Characterization Report Approved |
Reviewed 2014 Site Investigation Report for Greer Tank Facility. The objective of the investigation was to delineate the nature and extent of PCE impacts at the site and to gain a better understanding of the subsurface lithology to support an evaluation of remedial alternatives. Activities conducted as part of the site characterization included a ground-penetrating radar (GPR) survey, the advancement and sampling of 18 soil borings, and groundwater sampling at various depth intervals. The GPR data was used to locate boreholes away from buried utilities and also as part of an effort to map the eastern edge of a perched aquifer. This perched aquifer appears to be related to an interval of tightly packed silt with gravel and is associated with higher field screening results directly above this layer. The placement of boreholes and selection of soil samples was based on Color-Tec field screening. 44 soil samples were collected from the boreholes and analytical data indicate the presence of PCE above the cleanup level of 24 ug/kg in each of the boreholes except SB-12 on the Greer Tank property and SB-17 on the downgradient Stanley Motors property. The highest concentrations of PCE were detected at the northwest corner of the Greer Tank property in borehole SB-8 at 7-7.5 fet bgs with PCE detected at 10,200 ug/kg. Soil sampling confirmed the presence of two sources of PCE contamination, one along the northwest corner and another east of the Greer Tank building. The horizontal extent of PCE contamination above ADEC cleanup levels was not completely delineated due to laboratory LOQs above the cleanup level. Groundwater sampling was conducted at various intervals to evaluate the vertical distribution of PCE in groundwater below the perched aquifer. A sample from 45 feet bgs contained PCE below the cleanup level, but suggested that vertical migration had occurred, therefore additional sampling was conducted. Groundwater samples were collected from 55, 65, and 75 feet bgs from a temporary well but did not contain detectable concentrations of PCE. This additional investigation suggested the depth to the Bootlegger Cove clay, a regionally significant confining layer was between 55 and 65 feet. The data also suggests that PCE impacts are generally limited to soil and groundwater above the perched aquifer. |
Bill O'Connell |
| 4/27/2015 |
Document, Report, or Work plan Review - other |
Reviewed Additional Investigation Activities Work Plan for Greer Tank. The objectives of this additional work are to delineate the lateral extent of PCE impacts, install new monitoring wells, collect MNA parameters to evaluate groundwater chemistry, conduct a soil-vapor extraction pilot test, and develop a Site Cleanup Plan. Soil borings will be advanced and sampled in the north and northwestern areas of the site to delineate soil contamination. Field screening will be used to determine sampling locations in each borehole. Groundwater monitoring wells will be installed in 3 locations along the southern and eastern edges of the site to provide for further characterization of the groundwater and also provide an upgradient, background well. Groundwater samples will then be collected from 5 or 6 wells and analyzed for monitored natural attenuation parameters including dissolved oxygen, oxidation reduction potential, nitrate/nitrite, chloride, ferrous iron, sulfate, methane, total organic carbon and ethane/ethane. Evaluation of MNA parameters is intended to support remediation efforts and provide baseline groundwater chemistry information. One vapor extraction ell will be installed near the northwest corner of the Greer property near the contaminant source area. Vapor monitoring points will be installed 20-feet and 40-feet away. A step test and radius of influence (ROI) test will be conducted to evaluate the operational parameters of a full scale system and evaluate its ROI. Based on the results of this and previous studies, a cleanup plan will be developed for the site. |
Bill O'Connell |
| 6/9/2016 |
Document, Report, or Work plan Review - other |
Reviewed 2015 Remedial Activities report for Greer Tank. Remedial activities included the injection of an enhanced bio-remediation (EBR) solution consisting of an electron donor, a microbial culture and a chemical reductant designed to degrade the chlorinated hydrocarbons at the site and also the installation of a soil vapor extraction system (SVE). Temporary EBR injection points were installed at 45 locations throughout the contaminated area to a depth of 5-19 feet below ground surface and approximately 5,700 gallons of EBR solution were injected into the formation in August 2015. Groundwater samples were collected from select wells in November 2015 to evaluate remedial progress. Groundwater sample results indicated PCE was degrading and the breakdown products TCE, DCE, and vinyl chloride were starting to be detected or increased in concentrations. Monitored natural attenuation parameters also indicated that the EBR injections were beneficial to the anaerobic geochemical conditions required to degrade PCE at the site.
The SVE system was designed and installed based on results of the May 2015 pilot test. The system includes both horizontal and vertical extraction wells and was activated in November 2015. System optimization was conducted on several occasions following activation of the system. Exhaust samples were collected 4 hours, 24 hours, 1 week and 1 month after system startup to evaluate the concentrations of COCs being removed. Exhaust samples ranged from a high of 47,000 ug/m3 one hour after startup to 7,400 ug/m3 one month after startup. To minimize infiltration of precipitation and short-circuiting, a 20 foot by 40 foot portion of the site was paved with asphalt, however the majority of the site remains unpaved. Groundwater monitoring and SVE exhaust sampling will be performed again in 2016.
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Bill O'Connell |
| 6/20/2017 |
Document, Report, or Work plan Review - other |
Reviewed 2016 Annual Monitoring Report for Greer Tank. The objective of the 2016 monitoring effort was to gauge the effectiveness of active remediation efforts at the site including the SVE system installed in 2015 and injections of a chemical enhanced bioremediation (EBR) inoculant, also conducted in 2015. Groundwater monitoring events were conducted in May and December 2016 and included the collection of samples from 5 wells at the site that were analyzed for VOCs and also natural attenuation parameters. A vapor sample was collected from the effluent of the SVE system in July 2016 after approximately 8 months of system operation. Groundwater monitoring results indicate PCE is above the cleanup level only at MW-106, cis-1,2-DCE is above the cleanup level in MW-4 and MW-104, and vinyl chloride is above the cleanup level in MW-4 and MW-104. Contaminant analytical data indicate the EBR injections were successful at jump starting the reductive dechlorination process in groundwater at the site. PCE concentrations in the source area continue to decrease, while cis-1,2-DCE and vinyl chloride concentrations have increased. MNA parameters were evaluated using the EPA Technical Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Groundwater which indicated limited to adequate evidence for MNA per these parameters. The sample of effluent from the SVE system contained PCE at 5,600 ug/m3, a decrease from the startup concentration of 47,000 ug/m3, but indicative of the continued removal of PCE from the subsurface. |
Bill O'Connell |
| 7/13/2017 |
Document, Report, or Work plan Review - other |
Reviewed Site Investigation Work Plan for Greer Tank Facility. The objectives of the 2017 site investigation activities are to assess current PCE concentrations in vadose zone soils after two years of soil-vapor extraction and estimate the timeframe for contaminants to meet cleanup levels. Activities planned to meet these objectives include the installation and sampling of seven soil borings in the areas where PCE concentrations were highest during previous investigations. IDW soil will be containerized into drums and disposed of as F002 listed waste |
Bill O'Connell |
| 3/20/2018 |
Offsite Soil or Groundwater Disposal Approved |
one 55-gal drum of soil cuttings (from the 2017 site assessment) and one 55-gal drum of purge water (from annual groundwater monitoring events). The waste will be disposed of at US Ecology Idaho, Inc. (in Grand View, ID) as a combination of U-listed and F-listed hazardous waste. |
Erin Gleason |
| 5/7/2018 |
Site Characterization Report Approved |
The 2017 Site Investigation Report was submitted on 3/28/2018. Soil samples were collected at the same depth as the 2014 investigation, in the vadose zone, to determine the effectiveness of the soil vapor extraction (SVE) system. The SVE was installed after the 2014 sample collection and has been running for 20 months. By comparing the 2014 sample result to the 2017 results, we see that PCE has decreased 80% at 3.5-8 feet and 20% at 15.5-17 feet. ADEC reviewed and approved the report on 5/7/2018. |
Erin Gleason |
| 5/7/2018 |
Site Characterization Report Approved |
Received 2017 groundwater monitoring report from Rescon Alaska on 3/28/2018. PCE concentrations have decreased at source area wells ( MW4, MW104, MW106) and are below ADEC cleanup levels at MW4 and MW104. Cis 1,2 dichloroethane has decreased at MW4 and MW104 compared to its onset in 2016. MW4 exceeds ADEC cleanup levels for cis 1,2 dichloroethane. The concentration of Cis 1,2 dichloroethane at MW106 has increased since 2016. Vinyl chloride concentrations have increased at MW4 and MW 106, and decreased at MW104. Based on natural attenuation parameter results, anaerobic degradation continues in source area wells. Continued monitoring is recommended until all compounds are below ADEC cleanup levels. ADEC reviewed and approved the report on 5/7/2018. |
Erin Gleason |
| 7/30/2018 |
Document, Report, or Work plan Review - other |
Received soil characterization work plan from Rescon Alaska on 7/30/2018. The work plan will sample subsurface soil to the north east of the property for PCE and check the efficacy of the soil vapor extraction (SVE) system by sampling vadose soil adjacent to the SVE. A total of 6 soil borings will be advanced. ADEC has reviewed the work plan and request revisions. Revised work plan due 9/30/2018. |
Erin Gleason |
| 8/30/2018 |
Site Characterization Workplan Approved |
ADEC received the revised soil characterization work plan on 8/29/2018. The work plan includes all requested changes from the 8/21/2018 revisions requested letter. Soil characterization work plan is now approved. |
Erin Gleason |
| 9/20/2018 |
Site Characterization Workplan Approved |
ADEC received the 2018 enhanced bio-remediation and permeable reactive barrier injection work plan from Rescon. ADEC has reviewed the work plan and it is now approved. |
Erin Gleason |
| 7/15/2019 |
Document, Report, or Work plan Review - other |
Received 2018 annual monitoring report from Rescon dated 7/11/2019 on 7/15/2019. ADEC has reviewed the report and requests revisions nu August 22, 2019 |
Erin Gleason |
| 7/31/2019 |
Site Characterization Report Approved |
ADEC has received the draft 2018 Site investigation report from Rescon on behalf of Alaska National Insurance company on 5/22/2019. Five soil borings was advanced in summer 2018 to characterized extent of soil contamination on property. Surface and subsurface soil samples were analyzed. PCE was found at SB3 and SB9 above ADEC cleanup levels. Overall PCE concentration is down from the pre soil vapor extraction system installation in 2014. Groundwater was documented between 7-15 bgs. ADEC has reviewed the report and request revision by July 18th, 2019. ADEC received the revised report on 7/26/2019. Report is now approved. |
Erin Gleason |
| 8/8/2019 |
Workplan Requested |
ADEC requested a revised monitoring work plan due 9/30/2019 and a meeting prior to 9/15/2019 to discuss the work plan objectives. |
Erin Gleason |
| 9/12/2019 |
Update or Other Action |
Per request of Rescon, the deadline for work plan meeting is extended to October 15, 2019 and the deadline for the work plan to October 30, 2019. Understanding that any samples need to be collected after there is an updated work plan in place. |
Erin Gleason |
| 10/10/2019 |
Document, Report, or Work plan Review - other |
Received 2018 Annual Monitoring Report on 9/25/2019. ADEC has reviewed the report and it is now approved. The updated work plan is overdue as of 9/30/2019, no further sampling may take place until the work plan is in place. |
Erin Gleason |
| 10/17/2019 |
Meeting or Teleconference Held |
Meeting held between ADEC and Rescon to review site history, discuss data gaps and make plan for closure of the site and next steps towards closure. |
Erin Gleason |
| 10/30/2019 |
Exposure Tracking Model Ranking |
A new updated ranking with ETM has been completed for source area 72183 PCE Spill. |
Erin Gleason |
| 11/1/2019 |
Document, Report, or Work plan Review - other |
ADEC received the site characterization plan from Rescon on 10/25/2019. ADEC has reviewed the work plan and request changes. Revised work plan due November 22. |
Erin Gleason |
| 12/11/2019 |
Site Characterization Workplan Approved |
Received revised work plan, response to comments, and building survery from Rescon on 11/14/2019. ADEC has reviewed the work plan and it is now approved. |
Erin Gleason |
| 12/11/2019 |
Update or Other Action |
According to the building survey , the 2017 Groundwater Report and the 2013 Groundwater and Vapor Intrusion Report (dated November 28, 2013) there are no conditions present at the Stanley building that would indicate unacceptable vapor intrusion risk. The assumptions for this decision are as follows: contaminated groundwater is deeper than five feet below the slab, no preferential pathways to the subsurface are present, the concentration of vinyl chloride in the groundwater is less than the commercial target screening level of 25 micrograms per liter (µg/L). In 2017 the concentration of vinyl chloride in the groundwater adjacent to the Stanley Building was 0.71 µg/L. If the conditions of the Stanley Building or the groundwater change, the risk of vapor intrusion may need to be reassessed. |
Erin Gleason |
| 3/13/2020 |
Update or Other Action |
Approved transport of 55 gallon of purge water and 55 gallons of soil cuttings to US ecology in Idaho. Both drums have been designated as U-listed hazardous waste. |
Erin Gleason |
| 10/27/2020 |
Document, Report, or Work plan Review - other |
Received Draft 2019 annual monitoring report from Rescon Alaska on August 13th 2020. ADEC has reviewed the report and requests some additions be made. ADEC also requests that the next sampling event use EPA method 8260 SIM for VOC analysis instead of 8260C so that we can getmore accurate vinyl chloride data. |
Erin Gleason |
| 2/3/2021 |
Site Characterization Report Approved |
Received revised report from Reson Alaska LLC. ADEC has reviewed the report and it is now approved. Letter sent on this date. Monitoring will occur in 2021 according to the 2019 Work Plan with the addition of 8260 SIM for vinyl chloride. Rescon may submit a work plan for additional enhanced bioremediation in 2021, date to be determined. |
Erin Gleason |
| 3/10/2021 |
Update or Other Action |
Map of groundwater plume made in ADEC GIS mapper. |
Erin Gleason |
| 4/8/2021 |
Update or Other Action |
The cumulative risk for the remaining soil contamination was calculated using the under 40 inch precipitation zone,residential land use, and the soil data from the May 22, 2019 report. Contaminants of concern present in soil are vinyl chloride, cis-DCE, trans-DCE, PCE and TCE. The risk these compounds does not exceed a cumulative carcinogenic risk standard of 1 in 100,000 across all exposure pathways and has a cumulative noncarcinogenic risk standard at a hazard index of less than one across all exposure pathways. |
Erin Gleason |
| 8/11/2021 |
Site Characterization Workplan Approved |
Received EBR work plan from Rescon on 6/26/21. ADEC has reviewed the work plan and it is approved. Injection may take place between now and December 2022. |
Erin Gleason |
| 9/28/2021 |
Site Characterization Report Approved |
Received yearly monitoring report from Rescon on behalf of Alaska national on 8/9/21. ADEC has reviewed the report and it is now approved. Electronic letter sent to Alaska National on this date. |
Erin Gleason |
| 4/4/2022 |
Update or Other Action |
Call with Ryan Burich (Rescon Alaska) on this date to provide update: Groundwater sampling did not occur in 2021 to allow for water chemistry stabilization post-injection of microbes. A report will be submitted to ADEC in the next few weeks based on the injection. Groundwater sampling is scheduled to occur in May 2022. |
Naomi Mason |
| 7/7/2022 |
Update or Other Action |
Approved transport of 55-gallons of purge water and 55-gallons of soil cuttings to US Ecology in Idaho. Both drums have been designated as U-listed hazardous waste. |
Naomi Mason |
| 4/5/2023 |
Update or Other Action |
Letter sent on this date requesting the report for site remediation and subsequent groundwater monitoring conducted under the work plan approved in 2021 by April 30, 2023. Ryan Burich from Rescon Alaska stated in previous correspondence that the injection took place in 2021 and groundwater monitoring took place in May and October 2022. |
Naomi Mason |
| 6/28/2023 |
Site Characterization Report Approved |
ADEC received the "2022 Annual Monitoring Report" on June 6, 2023 and approved the report on this date. In 2022, two groundwater monitoring reports occurred (May and October). Generally, EBR amendments (injected in 2015, 2018, and 2021) have produced positive results. Laboratory analytical results revealed that tetrachloroethylene (PCE) concentrations did not exceed the groundwater cleanup level in any of the four groundwater monitoring wells sampled during the two sampling events in 2022. As expected, PCE degradation compounds (trichloroethylene [TCE], cis-1,2-dichloroethylene [cDCE], trans-1,2-dichloroethylene [tDCE], and vinyl chloride) have increased at source area monitoring wells and are above groundwater cleanup levels. No impacts were observed at the sentry well (MW-121). Continued monitoring for VOCs until contaminants of concern is recommended and ADEC has requested a work plan for groundwater monitoring and SVE system maintenance during 2023. |
Naomi Mason |
