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Site Report: Tudor Square, former Toppers

Site Name: Tudor Square, former Toppers
Address: 3401-3561 E. Tudor Rd.; , Anchorage, AK 99507
File Number: 2100.26.281
Hazard ID: 23893
Status: Cleanup Complete - Institutional Controls
Staff: IC Unit, 9074655229 dec.icunit@alaska.gov
Latitude: 61.181200
Longitude: -149.814300
Horizontal Datum:WGS84

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

Problems/Comments

1990 soil borings in the area of a former Toppers station (which was closed in 1985 without any soil or groundwater sampling) found gasoline and diesel contamination in the soil and groundwater. Monitoring wells were installed to define the extent of the groundwater contamination, which appears to extend to the northwest and also by Tudor Road. A bioventing system was installed and began operation in 1995. The system was upgraded in 1997 with air injection wells. The remediation system operated until October 2000. A monitoring well (MW9) was installed in the deeper aquifer and found to be free of contamination. 1,375 cubic yards of contaminated soil was excavated in 2006 and landfarmed for treatment at an off property location. Need confirmation soil samples to demonstrate that the off site landfarmed soils have been treated to default cleanup levels. Soil and groundwater contamination and possible vapor intrusion remain at the site. Groundwater monitoring, vapor intrusion assessment, and soil and ground water release investigation needed before this site can be evaluated for possible site closure with ICs. Active treatment of remaining soil and groundwater contamination may be required. FKA L74.07

Action Information

Action Date Action Description DEC Staff
10/1/1990 Underground Storage Tank Site Characterization or Assessment Federal Deposit Insurance Corp. sent notification of a potential oil discharge in on-site soil borings. Former Staff
10/16/1990 Site Added to Database Former Staff
10/16/1990 Release Investigation Phase II investigation by Quest Environmental. Ten borings installed. Gasoline and diesel contaminated soils encountered and estimated at 13,000 cubic yards. No final report received 7/9/91. Encountered clean to silty, sandy gravels. Groundwater at about 10 feet below the surface. Former Staff
10/16/1990 Leaking Underground Storage Tank Release Confirmed - Petroleum LUST Site created in CSP for source area ID 77954 Former Staff
10/17/1990 Leaking Underground Storage Tank Cleanup Initiated - Petroleum LCAU Date changed DB conversion Former Staff
7/1/1995 Leaking Underground Storage Tank Corrective Action Underway Polarconsult installs and begins operation of a bioventing system at the site. Robert Weimer
7/1/1997 Update or Other Action The site bioventing system is augmented with air injection wells. Robert Weimer
6/1/2000 Update or Other Action ADEC requests workplan for additional monitoring wells by 7/15/00. Former Staff
2/14/2001 Update or Other Action Meeting with RP and consultant to discuss future site work to achieve closure. Robert Weimer
9/11/2001 Document, Report, or Work plan Review - other September 11, 2001 groundwater sampling event. Monitoring wells MW7, MW8, and MW9 were sampled. Up to 42.9 mg/L DRO, 58.6 mg/L GRO, and 1,140 ug/L benzene was found in the groundwater. Depth to groundwater was 18 to 20 feet below ground surface in the shallow aquifer and 25 feet in the deeper aquifer (MW9). Robert Weimer
5/10/2002 Document, Report, or Work plan Review - other May 10, 2002 groundwater sampling. Two new monitoring wells (MW10 and MW11) were installed along Tudor Road to the west and east of the site. Both wells were no-detect for DRO, GRO, and BTEX. Depth to groundwater was from 10 to 14 feet below ground surface and flows toward the northwest. Robert Weimer
9/7/2002 Document, Report, or Work plan Review - other Three monitoring wells (MW7, MW8, MW9) were installed in September of 2001. Two more monitoring wells (MW10, MW11) were installed in May 2002. Up to 1.14 mg/l benzene, 58.6 mg/l GRO, and 42.6 mg/l DRO were found in the groundwater at monitoring well MW8 which is located near the southeast corner of Tract F-2B, near Tudor Road. Down gradient monitoring well MW9 was installed to the northwest of Tract F-2B in the deeper aquifer (40 feet below ground surface) and was found to be free of contamination. Robert Weimer
12/31/2002 Document, Report, or Work plan Review - other Two monitoring wells (MW5, MW6) were installed on 9/8/00. Three soil borings were drilled along the southern property boundary on 9/20/00. Up to 129 mg/kg benzene, 1,190 mg/kg GRO, and 621 mg/kg DRO were found in the soil samples. Up to 45 ug/l benzene, 3.47 mg/l GRO, and 4.15 mg/l DRO were found in monitoring well MW5. TOC samples were also collected from the three soil borings. Robert Weimer
1/5/2004 Document, Report, or Work plan Review - other Review release investigation report for the installation and sampling of 4 additional monitoring wells from September 2001 through May 2002. Shallow groundwater contamination found near Tudor Road in one well. Robert Weimer
8/3/2005 Update or Other Action Meeting with RP's consultant (Polarconsult) he will sample MW-5, MW-7, and MW-8 for BTEX, DRO, and GRO. Robert Weimer
10/25/2005 Update or Other Action Meeting with RP and consultant. They are to sample MW-5, MW-7, and MW-8 for BTEX, GRO, and DRO soon. Over the winter we are looking to define to what contamination concentration they will be excavating to in 2006. Robert Weimer
11/4/2005 Update or Other Action Approval of groundwater sampling plan. After review of results we are to meet to discuss corrective action goals for the Spring 2006 excavation corrective action work. Robert Weimer
3/29/2006 Document, Report, or Work plan Review - other November 10, 2005 groundwater sampling event. Monitoring wells MW5, MW7, and MW8 were sampled for GRO, DRO, and BTEX. Up to 3.46 mg/L GRO, 1.08 mg/L DRO, and 58.2 ug/l benzene in the groundwater. The contamination levels appear to be decreasing. Groundwater was at 9 to 10 feet below ground surface and appears to flow to the northwest. Robert Weimer
3/30/2006 Update or Other Action Talked with RP he will contact his consultant to put together a corrective action plan for cleanup work to happen in 2006. Robert Weimer
5/25/2006 Cleanup Level(s) Approved Based on site-specific soil data documenting high peat soils, the cleanup levels proposed and approved for this site are 0.3 mg/kg benzene, 148 mg/kg Ethylbenzene, 121 mg/kg Toluene, 2,100 mg/kg Xylenes, 1,400 mg/kg GRO and 4,400 mg/kg DRO. Robert Weimer
8/14/2006 Update or Other Action ADEC conditionally approves corrective action plan to remove and thermally treat up to 700 cubic yards of contaminated soil in the fall of 2006. Robert Weimer
8/14/2006 Update or Other Action File number issued 2100.26.281 (FKA L74.07). Aggie Blandford
10/12/2006 Update or Other Action Discussed recent site work with RP's consultant. 770 cubic yards of Peat, 250 cubic yards of clay, and 360 cubic yards of gravel were removed. He is looking at doing multi-incremental sampling to characterize the stockpiles for treatment/disposal. Robert Weimer
10/24/2006 Document, Report, or Work plan Review - other Review most recent excavation sampling data. Up to 97 mg/kg benzene and 1,900 mg/kg GRO remain in the excavation. The excavation work did not meet the excavation corrective action goals at the west sidewall in the peat, the east bottom in the clay, and the northeast, east, and southeast sidewalls in the peat. Robert Weimer
4/13/2007 Update or Other Action Discuss site with RP's consultant. A report of the 2006 excavation work, proposal for treatment of the contaminated peat, and recommendations for the remaining in place contamination will be included in the report. Robert Weimer
5/7/2007 Update or Other Action DEC receives notification that ASR will not accept the 767 cubic yards of peat soils for thermal treatment. The 249 cubic yards of clay soils were accepted by and treated by ASR. The 359 cubic yards of gravelly sand soils was placed back in the excavation. Robert Weimer
6/8/2007 Offsite Soil or Groundwater Disposal Approved Review and approved multi-increment sampling plan and corrective action plan to conduct off property landfarm treatment of the peat soil at a residential property. All soil is to be place more than 100 feet from drinking water wells and surface waters or other environmentally sensitive areas. Need confirmation soil samples to demonstrate that the landfarmed soils have been treated to default cleanup levels. Robert Weimer
7/6/2007 Offsite Soil or Groundwater Disposal Approved Approved 2.2 cubic yards of old drill cuttings to be treated with the peat soils. Robert Weimer
8/10/2007 Document, Report, or Work plan Review - other Review of final excavation sampling data. Up to 30 mg/kg benzene, 730 mg/kg GRO, and 860 mg/kg DRO remain in the excavation. The areas of remaining contamination above the excavation corrective action goals are 9 sample locations in the peat soils (2.6 to 5.7 feet below ground surface) in the northwest(1), north center(1), south center(1), southwest (3), and southeast(3) sidewalls. The base of the excavation and non-peat soils all met the excavation correcitve action goals. 24 of the 25 soil samples collected exceeded (or could exceed for benzene based on elevated detection limits) default cleanup levels. Robert Weimer
8/10/2007 Update or Other Action Discuss site with RP's consultant. He will provide Method 3 calculations for the peat soils, and sample monitoring wells MW7 and MW8. We discussed that additional site work is needed before the site can be considered for closure. They may need to install additional monitoring wells downgradient of the remaining soil contamination and may need active remediation (via excavation or in-situ remediation) in some areas. Robert Weimer
2/12/2008 Meeting or Teleconference Held Meeting with RP's consultant. We discussed that ADEC will need to review the proposed method 3 cleanup levels for the peat soils and compare those with the concentration of remaining contamination at the site. We discussed that we will probably need additional monitoring wells and soil samples to help define the extent of the remaining soil and groundwater contamination at the site. He will collect groundwater samples in monitoring wells MW-7 and MW-8 in the spring once the wells have thawed out. We also discussed that the indoor air pathway will need to be evaluated for this site. Later he will be submitting a site map showing the estimated soil and groundwater areas that exceed default cleanup levels. Robert Weimer
2/12/2008 Update or Other Action Supplemental information to support request for conditional closure was submitted on 2/13/2008. The request notes that based on previous discussions with DEC that they will need to collect additional site data (soil/groundwater/vapor intrusion) for the request to be reviewed. DEC has identified that additional groundwater monitoring is requested along with a vapor intrusion assessment for nearby buildings. DEC will also be requiring additional soil borings (and probably additional monitoring wells) to define the nature and extent of the remaining soil and groundwater contamination at this site. Once DEC has received the results of the 2008 groundwater monitoring and the building survey/work plan for conducting the vapor intrusion assessment, DEC can determine the additional site work is needed to evaluate the site for conditional closure. Robert Weimer
3/26/2008 Exposure Tracking Model Ranking Site ranked on the new Exposure Tracking Model (ETM). The ETM is a new site ranking system that looks at, based on available data, the potential exposure pathways for the contamination remaining at the site. Robert Weimer
6/27/2008 Update or Other Action Letter from property owner (Providence Health & Services Alaska) requesting a copy of the file and to be consulted prior to any decision on site closure. Robert Weimer
10/21/2008 Update or Other Action Send email to RP's consultant reminding him that I have not recieved a report on the results of the 2008 groundwater monitoring (monitoring wells MW7 and MW8) and the indoor air evaluation requested in the February 12, 2008 meeting. DEC needs this information before the DEC can determine what additional site work is needed to evaluate the site for possible closure with IC's. Robert Weimer
1/12/2011 Update or Other Action Send email request to RP and RP's consultant requesting the report on the results of the 2008 groundwater monitoring (monitoring wells MW7 and MW8) and any subsequent monitoring events and the indoor air evaluation requested in the February 12, 2008 meeting. DEC needs this information before the DEC can determine what additional site work is needed to evaluate the site for possible closure with IC's. Robert Weimer
10/28/2011 Update or Other Action Still have not received requested report on the results of the 2008 groundwater monitoring (monitoring wells MW7 and MW8) and any subsequent monitoring events and the indoor air evaluation requested in the February 12, 2008 meeting. DEC needs this information before the DEC can determine what additional site work is needed to evaluate the site for possible closure with IC's. Robert Weimer
1/30/2014 Update or Other Action Project manager changed to Amy Dieffenbacher, file transferred to Juneau Annie Ariel
6/2/2014 Update or Other Action Emailed RP and consultant with directions and list of information required for closure. Amy Rodman
6/4/2014 Document, Report, or Work plan Review - other Received corrective action report for peat landspreading remediation from Joel at Polarconsult. Amy Rodman
6/5/2014 Document, Report, or Work plan Review - other Received updated Corrective Action Report for peat landspreading remediation from Polarconsult Alaska Inc. with requested revisions via email. Amy Rodman
6/18/2014 Update or Other Action Corrective Action Report approval letter for landspread peat mailed to Ms. Gibbs, emailed to Polarconsult. Amy Rodman
8/13/2014 Update or Other Action ADEC Report Approval mailed to RP for "Site Decommissioning Report" submitted by Polarconsult Alaska, Inc. on July 21, 2014. Report documents decommissioning of subsurface features previously installed and operated at site. Amy Rodman
9/26/2014 Cleanup Complete Determination Issued Amy Rodman
9/29/2014 Institutional Control Record Established Institutional Controls established and entered into the database. Amy Rodman
5/21/2018 Institutional Control Compliance Review Staff changed from Amy Rodman to IC Unit. IC compliance review conducted. Closure/IC Details added to reflect the conditions established in the 2014 Cleanup Complete with Institutional Controls Determination. Kristin Thompson
5/24/2018 Institutional Control Update An IC reminder letter was issued this date. Reminder system set to follow-up every three years. Kristin Thompson
8/22/2024 Institutional Control Compliance Review IC compliance review completed on this date. An IC reminder letter was issued to the landowner. The next review will be in five years’ time. Gaige Robinson

Contaminant Information

Name Level Description Media Comments
Benzene > Human Health/Ingestion/Inhalation Soil benzene remaining in soil is above Outdoor Inhalation (Under 40" zone) of 11 mg/kg, but below Direct Contact cleanup level of 150 mg/kg.
Benzene > Table C Groundwater
DRO < Table C Groundwater
DRO Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation Soil
GRO > Table C Groundwater
GRO Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation Soil
Ethylbenzene Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation Soil
Ethylbenzene < Table C Groundwater
Toluene < Table C Groundwater
Toluene < Method 2 Most Stringent Soil
Xylenes (total) < Table C Groundwater
Xylenes (total) < Method 2 Most Stringent Soil

Control Type

Type Details
Signed CS Determination
Notice of Environmental Contamination

Requirements

Description Details
Other Municipality of Anchorage shall report to ADEC as soon as they become aware of any change in land ownership or use.
Other Soil contamination remains in the shallow peat layer that exists between two and six feet below ground surface along the southern property line. Benzene is the only contaminant that exists above site-specific, ADEC-approved soil cleanup levels in this peat layer. In 2006, confirmation soil samples along the southern property boundary, in the utility easement adjacent to Tudor Road confirmed contamination. Future utility workers should be aware of exposure to this subsurface soil.
Groundwater Use Restrictions Groundwater contamination remains in the shallow, non-potable aquifer that seasonally fluctuates, at approximately ten feet below ground surface. GRO and benzene are the only contaminants that remain in groundwater above Table C groundwater cleanup levels. According to 2005 groundwater sample results, contamination remains along the southern property boundary, in the utility easement adjacent to Tudor Road. Groundwater is not to be used for any purposes without prior notification and approval from ADEC. Groundwater is not to be used as a drinking water source.
Advance approval required to transport soil or groundwater off-site. Standard condition.
Movement or use of contaminated material (including on site) in a manner that results in a violation of the water quality standards is prohibited (18 AAC 70) Standard condition.
Other Standard condition.
Periodic Review ADEC will conduct a review of site conditions every three years.

No associated sites were found.

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State of Alaska Department of Environmental Conservation

P.O. Box 111800
Juneau, AK 99811-1800
Phone: 907-465-5066
Fax: 907-465-5245
TDD: 800-770-8973
Physical Location: 410 Willoughby