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Site Report: Dillingham Auto

Site Name: Dillingham Auto
Address: Main Street; , Dillingham, AK 99576
File Number: 2540.26.003
Hazard ID: 23487
Status: Active
Staff: Peter Campbell, 9072623412 peter.campbell@alaska.gov
Latitude: 59.038674
Longitude: -158.466712
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

Location: USS 1922 - west boundary; USS 1793 - east boundary; Lot 1, Block 32, Dillingham Townsite. Regulated underground storage tanks (USTs) removed in 1991. Soil contamination encountered and documented. In March 1992, ADEC requested a written response, plan, and time frame, for responding to the confirmed fuel release. No response was ever received from the responsible party (RP). In 2005 ADEC issued another letter requiring the current landowner (Delta Western) to provide a Capacity Assurance Plan (CAP) to complete the UST closure release investigation and corrective action. ADEC received and approved a CAP, and Shannon & Wilson is implementing that CAP on behalf of the new land owner, Delta Western, Incorporated. Updated 3/28/2007.

Action Information

Action Date Action Description DEC Staff
9/18/1991 Underground Storage Tank Site Characterization or Assessment SA1; Site assessment conducted during the removal of a 3,000 gallon UST. Petroleum contaminated soil documented. Site assessment did not conform with regs or approved QAPP. Petroleum contaminated soil stockpiled at the site. Former Staff
9/19/1991 Leaking Underground Storage Tank Release Confirmed - Petroleum LUST Site created in CSP for source area ID 77784 ADD; Former Staff
9/19/1991 Site Added to Database Former Staff
9/20/1991 Leaking Underground Storage Tank Cleanup Initiated - Petroleum LCAU; :LCAU Date changed DB conversion Former Staff
1/27/1992 Underground Storage Tank Site Characterization or Assessment SA1R; Site assessment report indicates that petroleum contaminated soil was discovered during the removal of a regulated 3,000 gallon gasoline tank. Site assessment was not conducted in accordance with 18 AAC 78 or the approved QAPP. Residual petroleum contamination exceeding cleanup levels remains at the site. Former Staff
1/27/1992 Update or Other Action NOR; Notice of Release letter sent 03/16/92. Requested response by April 30, 1992. Former Staff
11/20/1997 Update or Other Action ADEC sends Notification of Intent to Cost Recover Letter to Current Owner: ROBERT AIKENS & MARSHALL CORYELL Former Staff
12/2/2004 Update or Other Action File number 2540.26.003 assigned and entered into the Fileroom database and Leaking Underground Storage Tank database. Alyce Hughey
1/18/2005 Update or Other Action ADEC issued correspondence to last known RP (Mr. Steve Aikins), requiring that a CAP be submitted to respond to petroleum releases identified at the time of UST system closures. Alyce Hughey
2/23/2005 Update or Other Action ADEC issued correspondence to the current landowner, requiring submittal of a CAP to respond to petroleum releases, after the January 18, 2005 letter was returned by the US Postal Service. New owner is Delta Western, according to the City of Dillingham. Alyce Hughey
3/28/2007 Exposure Tracking Model Ranking Initial Site Ranking completed. Paul Horwath
6/21/2007 Update or Other Action Based on a request received from Delta Western's Bev Niemann, ADEC agreed to forego futher assessment and cleanup work at this site until the field season of 2008. Paul Horwath
4/22/2008 Leaking Underground Storage Tank Corrective Action Underway Reviewed and approved the March 31, 2008 Work Plan to Conduct Groundwater Investigation , 315 Main Street, Dillingham, Alaska, prepared by Shannon & Wilson for Delta Western. Work plan to implemented in May - June, 2008. Goal is to identify the groundwater flow direct, and extent of groundwater contamination. Paul Horwath
9/15/2009 Document, Report, or Work plan Review - other Reviewed the August 2009 Groundwater Investigation report, from Shannon & Wilson for Paul Horwath. Benzene was detected above the soil cleanup levels in three of the five soil borings performed, within B2, B3 and B5 at 2.5 to 10 feet below ground surface. GRO was detected above the groundwater cleanup levels in one of the newly installed monitoring wells TW2, and Benzene was detected above the groundwater cleanup levels in two of the newly installed monitoring wells, TW2 and TW3. It appears that the contamination has migrated to the extent of the newly installed soil borings and monitoring wells to the south and southwest of the former underground storage tank in the soil and groundwater. Based on the data submitted the contamination does not appear to be migrating off site. The groundwater flow direction was better established and it was determined to be flowing towards the southwest. With the primary source of the contamination removed it is recommended that periodic groundwater sampling be conducted at the site to monitor natural attenuation at the site. Alyce Hughey
11/17/2010 Document, Report, or Work plan Review - other Reviewed the Preliminary Groundwater Assessment, dated September 8, 2010, from Shannon & Wilson for Paul Horwath. During the Preliminary Groundwater Assessment performed in June and July of 2010 six of the seven monitoring wells were located (B1MW, B2MW, B4MW, TW1, TW2, TW3) well B3MW could not be found, and an unknown monitoring well was located. Of the six monitoring wells tested three wells remain below the groundwater cleanup levels and three wells detected benzene above the groundwater cleanup levels with one of the three wells detecting GRO above the groundwater cleanup levels. Two off site drinking water wells were located approximately 155 and 165 feet west-northwest of the property, installed at 105 and 140 feet below ground surface with static water levels at 7 and 12 feet below ground surface. Three additional monitoring wells were proposed to be installed to the south, south-west, and west of the site to further identify the down-gradient extent of the groundwater contamination. Several of the monitoring wells were found damaged or frost-jacked and no longer flush with the ground surface, and the repair of the monitoring wells is recommended along with the resurveying of the monitoring wells. Alyce Hughey
6/8/2011 Offsite Soil or Groundwater Disposal Approved Approved the disposal of purgwater and decontamination water to the Delta Western's Oil-Water separator, provided that the disposal of these nondomestic wastewaters into Delta Western's oil-water separator nondomestic wastewater treatment and disposal system doesn't cause any violations of Delta Western's permit. Paul Horwath
9/30/2011 Update or Other Action Based on the laboratory analytical data from a composite sample collected from the three 55-gallon drums currently stored on site, approval was issued for the disposal of the purged groundwater currently stored in three 55-gallon drums and the water to be generated during the 4th quarter 2011 groundwater sampling event to the surface onstie within the location of the source area. The water purged to the surface will be discharged at a slow enough flow rate to not allow for surface runoff. Paul Horwath
9/30/2011 Update or Other Action Based on the analytical soil sample results from the soil generated during the June 2011 monitoring well installation, approval was issued for the disposal of four 55-gallon drums of de minimus mass of contamination present within these soils to be distributed evenly across the ground surface within the source area located on site. Paul Horwath
12/20/2011 Document, Report, or Work plan Review - other Reviewed the Subsurface Investigation and Second Quarter 2011 Groundwater Monitoring Report, dated October 25, 2011, from Conestoga-Rovers and Associates. On June 17th and 18th, 2011 all existing monitoring well vaults B1MW through B4MW and TW-1 through TW-3 were repaired. On June 20, 2011 four new monitoring wells were installed MW-5 through MW-8. Three were installed along the western property boundary and one north of the tank farm to delineate the down-gradient extent of dissolved phase petroleum hydrocarbons. Soil samples taken detected DRO at 2.5 feet below ground surface at 430 mg/kg and Benzene was detected at 1.0 feet below ground surface at 0.16 mg/kg and at 2.5 feet below ground surface at 0.055 mg/kg within two of the soil samples. On June 21 and 22 the groundwater samples taken showed an increase in TW-2, with Benzene at 5.1 mg/L, Toluene at 14 mg/Land GRO at 79 mg/L, and for all the analytes in B1MW with concentrations that are more representative of the 2006 sampling event. The groundwater was flowing with a southwesterly direction with a gradient of 0.044 at depths of 0.55 to 5.20 feet below ground surface. The drinking water well survey conducted within 800 feet radius of the site found the closest well identified was Peter Pan Seafoods located to the north west of the site. The distance to the Nushagak River was measured and it was found south at approximately 427 feet down-gradient of the current station building. Alyce Hughey
1/6/2012 Document, Report, or Work plan Review - other Reviewed the Third Quarter 2011 Groundwater Monitoring Report, Dillingham, Alaska, dated December 1, 2011, from Conestoga-Rovers & Associates. On August 5, 2011 groundwater samples were taken from all the monitoring wells on site. Groundwater concentrations showed some increases and decreases with the highest concentrations being detected in monitoring well B1MW located in the area of the former UST location with DRO at 11.5 mg/L, GRO at 21.5 mg/L, and Benzene at 0.30 mg/L. The depth to groundwater ranged from 0.70 to 5.26 feet below ground surface. The groundwater was flowing southwest with a gradient of 0.06. Alyce Hughey
1/20/2012 Update or Other Action Approvel issued for the reduction of groundwater sampling to go from quarterly to semiannual (once every 6 months). Paul Horwath
7/10/2012 Document, Report, or Work plan Review - other Reviewed the Fourth Quarter 2011 Groundwater Monitoring Report, dated April 17, 2012, prepared by Conestoga-Rovers & Associates. The fourth quarter 2011 groundwater monitoring event was conducted on October 3, 2011 from all the monitoring wells on site. Groundwater concentrations showed some increases and decreases with highest concentrations being detected in monitoring well B1MW located in the area of the former UST location with DRO at 7.8 mg/L, GRO at 11.4 mg/L, and Benzene at 0.51 mg/L, and in two monitoring wells located on the west side of the property within MW-7 with DRO at 11.5 mg/L and Benzene at 0.14 mg/L, and within MW-8 with DRO at 11.7 mg/L, GRO at 3.3 mg/L and Benzene at 0.0070 mg/L. The depth to groundwater ranged from 2.13 to 5.76 feet below ground surface. The groundwater was flowing southwest with a gradient of 0.022. Alyce Hughey
7/16/2012 Offsite Soil or Groundwater Disposal Approved Conditionally approved for the transport and disposal of petroleum contaminated soil excavated from the site/property to the Columbia Ridge Landfill in Arlington, Oregon, based on the following condition: Delta Western/CRA shall provide our office with a final report covering this soil transport and disposal work which includes CRA's documentaiton of loading all soils into the shipping containers provided by Waste Management, Inc., include copies of manifests or shipping documents tracking the shipment of these soils by ship, rail, and truck to Columbia Ridge Landfill in Oregon, and lastly, paperwork documenting the receipt/acceptance of these soils by Columbia Ridge Landfill. Paul Horwath
7/26/2012 Offsite Soil or Groundwater Disposal Approved Conditionally approved for the transport and disposal of an additional 66 cubic yards, total of approximately 356 cubic yards of petroleum contaminated soil excavated from the site/property to the Columbia Ridge Landfill in Arlington, Oregon, based on the following condition: Delta Western/CRA shall provide our office with a final report covering this soil transport and disposal work which includes CRA's documentaiton of loading all soils into the shipping containers provided by Waste Management, Inc., include copies of manifests or shipping documents tracking the shipment of these soils by ship, rail, and truck to Columbia Ridge Landfill in Oregon, and lastly, paperwork documenting the receipt/acceptance of these soils by Columbia Ridge Landfill. Paul Horwath
9/6/2012 Document, Report, or Work plan Review - other Paul Horwath approved the July 31, 2012, Monitoring Well Installation Workplan, prepared by Conestoga-Rovers & Associates contingent upon compliance with the following condition: An Alaska registered professional land surveyor or professional engineer shall perform the horizontal and vertical monitoring well casing survey work, and certify by signature within the final report that the survey loop was closed to within an accuracy of 0.2 feet for horizontal coordinates, and within 0.01 foot for elevation. The installation of a monitoring well on Peter Pan Seafoods property will not be installed due to refusal of property access. Monitoring wells proposed for installation includes the following: the reinstallation of monitoring well MW-5, one near the Delta Western southern property line and one north of TW-2 on the north side of the Delta Western office building. Alyce Hughey
10/1/2012 Update or Other Action Paul Horwath approved for the decommissioning of monitoring wells TW-1 and TW-3 due heaving and well screens currently above grade. Alyce Hughey
11/27/2012 Document, Report, or Work plan Review - other Reviewed the First Semiannual 2012 Groundwater Monitoring Report, dated August 31, 2012, prepared by Conestoga-Rovers & Associates. The first semiannual groundwater monitoring event for 2012 was conducted on June 5, 2012. All monitoring wells were sampled except TW-1 due to ice in the well. Monitoring well B1MW concentrations remain elevated with DRO at 3.8 mg/L, GRO at 16.3 mg/L, Benzene at 0.52 mg/L, and Toluene at 2.0 mg/L. Two additional monitoring wells concentrations remain elevated, MW-5 located south of the former UST location and MW-7 located southwest of the former UST location on the west side of the property. MW-5 was destroyed after the well was sampled in June of 2012, and has been approved to be reinstalled. The depth to groundwater ranged from 1.12 to 5.37 feet below ground surface. The groundwater was flowing southwest with a gradient of 0.02. Alyce Hughey
1/30/2013 Document, Report, or Work plan Review - other Reviewed the Second Semiannual 2012 Groundwater Monitoring Report, dated December 20, 2012, prepared by Conestoga-Rovers & Associates. The second semiannual groundwater monitoring event for 2012 was conducted on September 14 through 16, 2012. All monitoring wells were sampled except TW-3 due to a flooded well casing from surface water runoff, and MW-9 due to a large amount of surface water puddle up over the well vault. Groundwater contamination was detected with Benzene at 0.0064 to 0.36 mg/L, GRO at 3.1 to 8.3 mg/L and DRO at 1.9 to 8.5 mg/L. Well B3MW detected GRO above the groundwater cleanup levels for the first time, and B4MW detected DRO above the groundwater cleanup levels for the first time. An additional seep sample was collected near the southwest corner of the Delta Western Terminal property boundary, with Benzene at 0.38 mg/L and GRO at 3.8 mg/L. MW-5 was destroyed after the well was sampled in June of 2012, and MW-5R was installed to replace MW-5. The depth to groundwater ranged from 0.64 to 5.33 feet below ground surface. The groundwater was flowing towards the south with a gradient of 0.03. Alyce Hughey
2/20/2013 Document, Report, or Work plan Review - other Reviewed the Well Installation and Decommissioning Monitoring Report, dated January 21, 2013, prepared by Conestoga-Rovers & Associates. The installation of three groundwater monitoring wells (MW-5R, MW-9, MW-10) was performed on September 13, 2012. Monitoring well MW-5R was installed to replace MW-5 that was decommissioned in June of 2012 during site upgrades. Monitoring well MW-9 was installed north of the Delta Western office building to assess up-gradient of TW-2. Monitoring well MW-10 was installed near the terminal’s southwest property boundary to further define the extent of the plume. MR-5R detected DRO at 2 feet bgs at 563 mg/kg, and DRO at 394 mg/kg and Benzene at 2.8 mg/kg at 4 feet bgs. MW-10 detected DRO at 518 mg/kg and Benzene at 0.41 mg/kg at 6 feet bgs. Groundwater monitoring wells (TW-1 and TW-3) were decommissioned on October 10, 2012. On June 6, 2012, the Peter Pan Seafoods drinking water well was located on the property and was found cross gradient of the site with a total depth of the well at 73.0 feet below top of casing. Alyce Hughey
3/26/2013 Document, Report, or Work plan Review - other Reviewed the Soil Characterization Report, dated January 18, 2013, prepared by Conestoga-Rovers & Associates. This area of concern is being worked in the Delta Western Farm - Dillingham site under source area ID: 79420. This area of contamination was in the area of former MW-5 location for the Dillingham Auto site. On June 21 through June 27, 2012, during the excavation of a footprint for a new truck loading rack, consisting of six footings and a trench surrounding the footprint, three two-inch galvanized steel lines were encountered in the northwest corner of the excavation. The lines were not in service, but contained a small amount of LNAPL. Contaminated soil and groundwater was encountered at a depth of 2.5 feet below ground surface. Soil samples collected at 2.5 feet bgs detected benzene at 0.486 to 93 mg/kg, ethylbenzene at 7.780 to 298 mg/kg, toluene at 7.780 to 1,110 mg/kg, xylenes at 219.10 to 1,506 mg/kg, GRO at 340 to 9,980 mg/kg, and DRO at 989 to 25,000 mg/kg. The grab groundwater samples collected within the excavation detected DRO at 2.07 mg/L. Monitoring well MW-5 installed in this area for the Dillingham Auto site was decommissioned during the excavation, and then on September 13, 2012 monitoring well MW-5R was installed to replace MW-5. Approximately 545 tons of impacted soil was removed during the excavation and temporarily stored on-site in supersacks. On July 16, 2012, ADEC approved for the transport and disposal of the contaminated soils to Columbia Ridge Landfill in Arlington, Oregon with the condition that certificates and disposal and waste manifests be presented to ADEC. On September 25th through September 27th, 2012 twenty-three containers were loaded with 180 supersacks (approximately 545 tons of soil) for transport to Columbia Ridge Landfill in Arlington, Oregon. Alyce Hughey
6/25/2013 Update or Other Action Paul Horwath approved to discharge purged groundwater generated during first semiannual groundwater sampling to the surface within the location of the source area. Purge water discharged to the ground surface will be discharged at a slow enough flow rate to not allow for surface runoff. Alyce Hughey
9/17/2013 Exposure Tracking Model Ranking A new updated ranking with ETM has been completed for source area 77784 Former USTs. Paul Horwath
10/29/2013 Update or Other Action Paul Horwath approved for the onsite disposal of the petroleum impacted water stored in 5-55-gallon drums. Based on the average of the concentrations reported by the analytical laboratory, and the relatively limited quantity of water requiring disposal, the contents of these five (5) 55-gallon drums of water may be disposed of on the former Dillingham Auto site, at the location of the historically identified UST impacted soil and groundwater, and to ensure no surface runoff occurs outside the area of known historical impacts, and that the water infiltrates the ground surface at the area of known historical soil and groundwater impacts associated with the former regulated underground storage tank systems. Alyce Hughey
11/8/2013 Update or Other Action Paul Horwath approved for the disposal of groundwater stored at this site, and groundwater that will be generated during the upcoming sampling event. These waters are to be disposed on the Former Dillingham Auto site, at the location of the historically identified UST impacted soil and groundwater, making sure no surface runoff occurs outside the area of known historical impacts, that the water infiltrates the ground surface at the area of known historical soil and groundwater impacts associated with the former regulated underground storage tank systems. Alyce Hughey
12/16/2013 Document, Report, or Work plan Review - other Reviewed the First Semiannual 2013 Groundwater Monitoring Report, dated October 18, 2013, from Conestoga-Rovers and Associates. The first semiannual groundwater monitoring event for 2013 was conducted on June 4th and 5th, 2013. All monitoring wells were sampled except MW-5R due to ice in the well at 4.15 feet. Groundwater contamination was detected with Benzene at 0.0064 to 0.32 mg/L, Toluene at 1.7 mg/L, Xylenes at 10.2 mg/L, GRO at 2.5 to 33.3 mg/L and DRO at 1.8 to 7.8 mg/L. Monitoring well M1MW had an increase in GRO from 8.3 to 33.3 mg/L and Xylenes from 1.8 to 10.2 mg/L. The depth to groundwater ranged from 0.47 to 6.77 feet below ground surface. The groundwater was flowing towards the southwest with a gradient of 0.03. Alyce Hughey
2/28/2014 Document, Report, or Work plan Review - other Reviewed the Second Semiannual 2013 Groundwater Monitoring Report, dated February 2014, prepared by Conestoga-Rovers & Associates. The second semiannual groundwater monitoring event for 2013 was conducted on September 10th and 11th of 2013. All existing monitoring wells were sampled. Groundwater contamination was detected with Benzene at 0.0072 to 0.23 mg/L, GRO at 2.7 to 14.3 mg/L and DRO at 2.5 to 9.3 mg/L. The depth to groundwater ranged from 0.36 to 5.31 feet below ground surface. The groundwater was flowing towards the southwest with a gradient of 0.04. Alyce Hughey
6/11/2014 Update or Other Action Paul Horwath requested Delta Western to provide a corrective action plan which clarifies the adjusted groundwater sampling schedule for all the monitoring wells, which includes the relaxing of the sampling schedule for wells B3MW and M4MW to once per year, rather than twice yearly, addresses the installation of a replacement monitoring well for TW-3, and the installation of additional monitoring wells to determine groundwater quality prior to groundwater emergence into the Nushagak River. Alyce Hughey
7/7/2014 Site Characterization Workplan Approved Reviewed and approved the Conestoga-Rovers & Associates, July 2014 Monitoring Well Installation Workplan. Paul Horwath
8/24/2015 Document, Report, or Work plan Review - other Received and reviewed GHD's August 24, 2015, First Semiannual Groundwater Monitoring and Sampling Report. Signed by John Riggi. MW-11 close to the Nushagak River greatly exceeds ADEC Water Quality Standards for TAH and TAQH. Paul Horwath
3/4/2016 Document, Report, or Work plan Review - other Review GHD's 2nd Semiannual 2015 GW Monitoring Report, dated February 15, 2016. Paul Horwath
7/18/2023 Update or Other Action Groundwater monitoring for this site is managed under the Delta Western Tank Farm project (File Number 2540.38.017). The contaminated sites share a common responsible party and the plumes have comingled. Peter Campbell

Contaminant Information

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Control Type

Type Details

Requirements

Description Details

No associated sites were found.

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