Site Report: Residence - 5100 South Dottie Lou Lane HHOT

Site Name:	Residence - 5100 South Dottie Lou Lane HHOT
Address:	5100 South Dottie Lou Lane, 7.9 Mile South Big Lake Road, Big Lake, AK 99652
File Number:	2202.38.011
Hazard ID:	4607
Status:	Cleanup Complete
Staff:	No Longer Assigned, 9074655229 dec.icunit@alaska.gov
Latitude:	61.523340
Longitude:	-149.901490
Horizontal Datum:	NAD83

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.

Site Chronology
IC / Closure Details
Documents
Associated Sites

Problems/Comments

On or about 6/5/07 a contractor accidentally bumped the valve from the 300-gallon aboveground heating oil tank leading to a Toyostove inside the residence that was disconnected. Approximately 30 gallons of diesel fuel were released inside the residence, seeped through the floor boards, and onto the ground under the northwest side of the building. Contamination impacted groundwater at ~12 feet below ground surface. On-site drinking water well (20 feet SE and upgradient of source area) was sampled on 10/27/07 and was non-detect for VOCs. As of 10/15/10, DRO and benzene remain in soil above ADEC cleanup levels. As of 11/2/07, 226 super sacks representing 264 tons of contaminated soil has been transported to Alaska Soils Recycling awaiting thermal treatment. Lon Wilson also owns parcels due north (B19), due south (B15), and southwest (B16) of the subject property. The Alaska Department of Environmental Conservation (ADEC), Contaminated Sites Program has completed a review of the environmental records associated with Residence-5100 South Dottie Lou Lane Home Heating Oil Tank (HHOT) located at 5100 South Dottie Lou Lane, Big Lake, Alaska 99562. Based on the information provided to date, the ADEC has determined that the contaminant concentrations remaining on site do not pose an unacceptable risk to human health or the environment, and this site will be closed. In June 2007 a 300-gallon above-ground tank (AST) supply line released diesel into the cabin located on-site and diesel seeped through the flooring to the ground surface under the northwest side of the structure. It is estimated that approximately 10 to 30 gallons of diesel was released during the spill. A total of 263.77 tons of impacted soil was excavated from the site during spill response activities. Confirmation soil samples collected from the excavation at 10-12 feet below ground surface indicated diesel range organics (DRO) and benzene remained at concentrations above ADEC cleanup levels, with DRO detected up to 2,170 mg/kg and benzene detected up to 0.101 mg/kg. Groundwater was encountered in the excavation at 12 feet bgs. The two wells were sampled again in October 2009 and July 2010. DRO was detected in MW-2 at 8.85 mg/l during the October sampling event; however contaminants were not detected above cleanup levels in the July sampling event. The July 2010 samples were analyzed using a silica gel cleanup process to remove naturally occurring organics from the sample prior to analysis, and a review of the chromatograms from the October 2009 sampling event support the concept that naturally occurring organics were responsible for the DRO detected in the October 2009 samples. Groundwater samples were collected again in July 2011 and analyzed using silica gel cleanup. Contaminants were not detected above cleanup levels. Because of the proximity to Big Lake and because a complete pathway exists for groundwater to migrate to surface water, groundwater analytical data were also compared to 18 AAC 70 Alaska Water Quality Standards (AWQS) for total aromatic hydrocarbons (BTEX) and total aqueous hydrocarbons (BTEX + PAHs). Contaminants were not detected above AWQS.

Action Information

Action Date	Action	Description	DEC Staff
7/14/2007	Potentially Responsible Party/State Interest Letter	Letter of Interest hand delivered to Mr. Lon Wilson.	Mark Sielaff
8/8/2007	Cleanup Plan Approved	Received and approved a cleanup plan from Emerald Alaska, Inc.	Mark Sielaff
8/8/2007	Update or Other Action	A work plan from Emerald Alaska, Inc. titled "ADEC Spill Number: 07239915601 Lon Wilson Residence locateds at mile 7.9 South Big Lake Road" dated 8/8/07 was received.	Mark Sielaff
8/31/2007	Cleanup Plan Approved	A letter this date provided Emerald Alaska, Inc. written authorization to conduct the cleanup, removal, and disposal of materials contaminated by an oil or hazardous substance spill. Any soil transported from the site shall be done in a manner that prevents its dispersal en route. This letter authorizes 63 covered super sacks filled with over 63 cubic yards of contaminated gravel and soils to be transported from the site to Alaska Soils Recycling in Anchorage for thermal treatment. This letter was in response to the Emerald Wor Plan received 8/8/07.	Mark Sielaff
10/9/2007	Update or Other Action	Emerald Alaska stated that pit sidewalls were clean. Water was encountered during search for vertical limit of contamination. PID readings were "hot" at the bottom of the pit.	Mark Sielaff
10/19/2007	Site Characterization Report Approved	Requested and received initial "closure" sample results dated 10/16/07 from Emerald Alaska Inc. Sampling for GRO, DRO, RRO, and BTEX indicated that Sample BLS-1 results taken at 12' bgs in the west side if the excavation exceeded the DRO and benzene cleanup levels. The results were 1,610 mg/kg and 0.039 mg/kg, respectively. The results for sample BLS-2 taken at 10' bgs at the bottom of the southwest side of the excavation exceeded the cleanup levels for DRO, benzene, and ethylbenzene at 2,170 mg/kg, 0.101 mg/kg and 6.75 mg/kg, respectively, as well.	Mark Sielaff
10/23/2007	Offsite Soil or Groundwater Disposal Approved	Jim Rogers of Alaska Soil Recycling was contacted and indicated that 226 super sacks of contaminated soil weighing 263.77 tons was received from the site.	Mark Sielaff
11/2/2007	Meeting or Teleconference Held	A meeting was held to discuss the site status. In attendance were Mark Sielaff and John Brown of ADEC/PERP, Rich Sundet of ADEC/CSP, Blake Hillis and Mike High of Emerald Alaska, Lon Wilson the landowner, Steven Tervooren, RP attorney, and David Nyman of Restoration Science and Engineering. Both the PERP and the CSP discussed their positions. Site was transferred from PERPS to CSP and Emerlad was relieved of their services.	Mark Sielaff
11/2/2007	Spill Transferred from Prevention Preparedness and Response Program	Site transferred by PERP staff Mark Sielaff. Spill No. 07239915601; Spill Date 6/5/07; CATS No. 07-0119-10; Substance = Diesel; Quantity = ~30 Gallons; Spill Name = Lon Wilson Heating Oil Tank Spill Big Lake, AK. To date, 226 super sacks representing 264 tons of contaminated soil has been transported to Alaska Soils Recycling awaiting thermal treatment.	Mark Sielaff
11/8/2007	Update or Other Action	PERP received a copy of the Restoration Science & Engineering "Spill Cleanup Report Lot 11, Linda Scott Subdivision, 5100 Dottie Lou Lane, Big, Lake, Alaska (ADEC Spill Report No: 072399156001)" dated 11/5/07.	Mark Sielaff
11/13/2007	Update or Other Action	Sent an email to Rich Sundet of the CSP indicating that Emerald Alaska, Inc. was relieved of their cleanup obligations by Lon Wilson and replaced with David Nyman of Restoration Science and Engineering.	Mark Sielaff
12/8/2007	Site Characterization Report Approved	Received an email with an attached Restoration Science and Engineering (RSE) report titled "Additional Cleanup and Sampling November 5, 2007; Lot 11, Linda Scott Subdivision, 5100 S Dottie Lou Lane, Big Lake, Alaska (ADEC Spill Report No: 072399156001)" dated 12/5/07 containing second site sample results. RSE redug contaminated soil on 11/5/07 and found the southwest and its duplicate sample for DRO, RRO and BTEX to be within cleanup levels. RSE augered into a vein of gravel on the west side of the excavation which the contamination followed horizontally and found very high levels of contamination. The west side excavation samples from 12' deep resulted in exceedances of the cleanup levels for DRO at 3,080 mg/kg and benzene at 0.0409 mg/kg.	Mark Sielaff
12/10/2007	Update or Other Action	Requested what the future intentions of site work were to Lon Wilson.	Mark Sielaff
12/13/2007	Update or Other Action	In response to an email to Lon Wilson dated 12/10/2007 as to future intentions of site work, the PERP received a letter dated both 12/12/07 and 12/13/07 from Mr. Tervooren, attorney, requesting site closure based on de minimus soil residue.	Mark Sielaff
3/13/2008	Site Added to Database	Site added to the database.	Mitzi Read
3/13/2008	Exposure Tracking Model Ranking	Initial ranking with ETM completed.	Mitzi Read
9/17/2008	Site Characterization Report Approved	The Contaminated Sites Program (CSP) performed a review of the Restoration Science & Engineering "Spill Cleanup Report Lot 11, Linda Scott Subdivision, 5100 Dottie Lou Lane, Big, Lake, Alaska (ADEC Spill Report No: 072399156001)" dated November 5, 2007 and "Additional Cleanup and Sampling November 5, 2007; Lot 11, Linda Scott Subdivision, 5100 S Dottie Lou Lane, Big Lake, Alaska (ADEC Spill Report No: 072399156001)" dated December 5, 2007. This site is located within 185 feet of Big Lake. The release of approximately 30 gallons of home heating fuel from an approximate 300-gallon aboveground storage tank (AST) was discovered on June 6, 2007. Approximately 176 cubic yards of hydrocarbon-impacted soil were removed from the spill source area and transported to Alaska Soil Recycling, Inc. (ASR) in Anchorage for thermal treatment. Analytical soil sampling results indicated diesel-range organics (DRO), benzene, and ethylbenzene levels above the 18 AAC 75.341 Method 2 cleanup levels. Analytical ground water sampling results indicated DRO, RRO, and benzene levels above the 18 AAC 75.345 Table C Cleanup Levels. A letter from the CSP was sent this date in response to the review of the report and requested a work plan outlining further soil and ground water characterization and sampling in the fall of 2008 for DRO, gasoline-range organics (GRO), RRO, and benzene, toluene, ethylbenzene, and total xylenes (collectively referred to as BTEX). The responsible party was asked to account for prior investigative derived soil and groundwater waste. A Conceptual Site Model was lacking in the report and requested along with the work plan. (Petrik)	Bill Petrik
9/25/2008	Update or Other Action	Contacted Mr. Richard Anderson via telephone this date to inform him that per the Contaminated Sites Program (CSP) protocol the CSP is planning on sending a Potentially Responsible Party (PRP) letter to him. In the conversation, Mr. Anderson indicated that in no way was he accepting responsibility for the spill and he subsequently is in the process of litigation regarding this issue. He will accept the letter knowing that it is a formality as a part of the CSP doing their job.	Bill Petrik
11/5/2008	Potentially Responsible Party/State Interest Letter	The Contaminated Sites Program (CSP) completed a Potentially Responsible Party Letter for the site and sent it certified mail, return receipt requested to the owner of a contracting company along with an "ADEC INFORMATION REQUEST, Concerning a Contaminated Site(s)", and an ADEC "Cleanup Process, Cleanup of Contaminated Sites in Alaska" pamphlet. The site has contaminated soil and/or water associated with a home heating oil aboveground storage tank (AST) release that was located on the property when the fuel line was severed between the AST and the residence by a contracting company staff.	Bill Petrik
11/20/2008	Site Characterization Workplan Approved	The Contaminated Site Program (CSP) completed a review of the Restoration Science & Engineering (RSE) document "Site Investigation Workplan: Installation of Monitoring Wells and Soil Borings at Lot 11, Linda Scott Subdivision near Big, Lake, Alaska" dated November 11, 2008. A letter was sent conditionally approving the work plan. The site experienced an estimated release of 10-30 gallons of home heating oil fuel and further work is needed. Two borings are proposed to be drilled down gradient and sampled for GRO, DRO, and BTEX as an attempt to determine the vertical and lateral extent of the contamination. Groundwater is contaminated and the two proposed borings are planned to be finished as monitoring wells and sampled for GRO, DRO, and BTEX as well. Polycyclic aromatic hydrocarbons (PAH) will be added to the analytical testing for soil and groundwater if the sum of the hydrocarbons in the resulting analytical soil results exceeds 500 mg/kg. Total aromatic hydrocarbons (TAH) and total aqueous hydrocarbons (TAqH) groundwater sampling and analysis is also planned, as the site is within 150 feet of Big Lake. A Conceptual Site Model has not previously been submitted and was requested with the report of findings resulting from this work plan. A site characterization report will be submitted after completion of proposed work tasks and submitted to the ADEC for review within 60 days from the conclusion of sampling.	Bill Petrik
2/10/2009	Update or Other Action	In a letter dated 2/10/09, the Contaminated Sites Program responded to Mr. Wilkens' letter dated November 20, 2008 to Mr. Bill Petrik of the Department’s Contaminated Site staff concerning the liability of your client Mr. Richard Anderson dba Complete Painting & Etc.	Rich Sundet
3/3/2009	Update or Other Action	In response to the subpoenas received on 1/28/09 at the request of James Wilkens (representing Richard Anderson dba Complete Painting & Etc.), on 3/3/09 Rich Sundet of the CSP and Mark Sielaff of the PERP gave depositions. Attending the depositions were Lon Wilson and his counsel, counsel for Tim Clemmer dba Clemmer Construction, Wilkens, and Tostevin of the Attorney General's Office.	Rich Sundet
8/17/2009	Document, Report, or Work plan Review - other	Reviewed a copy of the Restoration Science & Engineering "Environmental Site Assessment Letter Report: Installation of Groundwater Monitoring Wells at 5100 South Dottie Lou Lane in Big Lake Alaska (ADEC File No. 2202.38.011)" dated 6/4/09, received 8/11/09. On March 19, 2009, two groundwater monitoring wells, MW-1 and MW-2, were installed at the subject property. MW-1 is approximately 70 feet northwest of the house and MW-2 is approximately 130 feet northwest of it. It is approximately 70 feet from MW-2 to the shore of Big Lake. After screening soil during drilling, two samples and one duplicate were collected and submitted for laboratory analysis of diesel-range organics (DRO), gasoline range-organics (GRO) and benzene, toluene, ethylbenzene and total xylenes (collectively referred to as BTEX) and polynuclear aromatic hydrocarbons (PAH). Generally, a soil sample was collected and analyzed from the highest PID field-screened sample interval, which was at the soil/water interface for each monitoring well. The soil sample collected from MW-2 and the duplicate of the sample from MW-1 did not detect any target analytes. The original sample from MW-1 exhibited concentrations of GRO, DRO, and total xylenes at 0.813 milligrams per kilogram (mg/kg), 14.1 mg/kg, and 0.0245 mg/kg which were all laboratory estimates. These values are considerably below the ADEC 18 AAC 75 Table B1 Method Two soil cleanup levels of 300 mg/kg, 250 mg/kg, and 63 mg/kg, respectively. During drilling on March 19, 2009, groundwater was encountered in MW-1 at approximately six feet below the ground surface (bgs) with a confining layer of silt initially observed at approximately 10 feet bgs and continuing to at least the bottom of the boring. Groundwater was initially encountered in MW-2 at approximately nine feet bgs but rose to 2 feet bgs after drilling, above the screened interval, which was from 5-10 feet bgs. Due to cold conditions, sampling of the wells did not occur on the date of drilling. On April 16, 2009, RSE conducted groundwater sampling from both wells including a duplicate and submitted them for laboratory analysis for DRO, GRO, and BTEX. Groundwater samples MW-1 and MW-3 (duplicate of MW-1) were also analyzed for PAHs. There were detections of some target analytes in all groundwater samples. Groundwater sample MW-2 exhibited concentrations of DRO at 0.519 mg/L, GRO at 0.0204 mg/l, and toluene at 0.00492 mg/L. The maximum detected values of sample results from MW-1 and its duplicate MW-3 were DRO at 0.292 mg/l, GRO at 0.0138 mg/l, and total xylenes at 0.000631 mg/l. Groundwater sample results were compared to the ADEC 18 AAC 75 Table C groundwater cleanup levels and the detections were all below the Table C cleanup levels of 1.5 mg/l for DRO, 2.2 mg/l for GRO, 1 mg/l for toluene, and 10 mg/l for total xylenes. All other groundwater samples exhibited non-detectable (ND) concentrations of target analytes for DRO, GRO, BTEX, and PAHs. Based on the analytical soil and groundwater sampling results the investigative derived soil and groundwater waste may be disposed on site provided its disposal complies with 18 AAC 75.370. In particular, (2)(A) states “100 feet or more from surface water, a private water system, a Class C public water system as defined in 18 AAC 80.1990, or a fresh water supply system that uses groundwater for a use designated in 18 AAC 70.020(a)(1)(A) and 18 AAC 70.050(a)(2)”. In addition, the area of disposal shall not be an environmentally sensitive area such as wetlands or subject to runoff to a surface water body. Numerous items requested in the CSP letter dated November 21, 2008 conditionally approving the work plan for the most recently completed work are lacking or not reported. They include: • Development of a CSM and summaries of soil and groundwater data relative to risk pathways; • The ice surface elevation was measured in the latest site work as a third water level surface as part of the calculation of groundwater gradient and flow direction. This task was contrary to the CSP work plan request to use the water surface and not the ice surface. • During each groundwater sampling event, a visual site inspection of Big Lake downhill from the site shall occur and a finding of inspections of Big Lake for possible sheening downhill from the site. • Calculation of the groundwater flow gradient and direction. • Sampling at least twice after the initial sampling event.	Bill Petrik
10/15/2009	Document, Report, or Work plan Review - other	A letter was sent to the RP after review of the Restoration Science & Engineering Documents "Environmental Site Assessment Letter Report: Installation of Groundwater Monitoring Wells at 5100 South Dottie Lou Lane in Big, Lake Alaska (ADEC File No. 2202.38.011)" dated June 4, 2009 and received 8/11/09, and "Questions on and Corrections to Environmental Site Assessment Letter Report: Installation of Groundwater Monitoring Wells at 5100 South Dottie Lou Lane in Big, Lake Alaska" dated September 22, 2009, received 10/1/09. The letter requested: two further sampling events, one to occur in Fall 2009 and the second in Spring 2010; that the work be done when the lake is ice free or when there are no issues with freeze-up or break-up to minimize any interpretation these events may have upon determining normal hydraulic conditions; submittal of a CSM and summaries of soil and groundwater data relative to risk pathways; measure the elevation of the water surface instead of the ice surface as part of the calculation of groundwater gradient and flow direction; during each groundwater sampling event make a visual site inspection of Big Lake downhill from the site for possible sheening from the site; calculation of the GW flow gradient and direction; and GW sampling at least twice more. Ensure that the items outlined above that are missing in the subject reports are addressed and included in the report for the next sampling. Please submit the report for the next sampling within 60 days of receiving the laboratory sampling results report.	Bill Petrik
6/18/2010	Document, Report, or Work plan Review - other	Reviewed a copy of the Restoration Science & Engineering (RSE) "Environmental Site Assessment Letter Report: Fall 2009 Groundwater Monitoring at 5100 Dottie Lou Lane in Big Lake Alaska (ADEC File No. 2201.38.011)" dated 12/16/09 received 2/11/10. On 10/29/09, RSE field personnel measured the depth to GW and collected GW samples from MWs MW-1 and MW-2. MW-2 is the well closest to Big Lake. Two samples and one duplicate of MW-2 were collected and submitted for laboratory analysis of DRO and BTEX. The analytical results for the sample from MW-1 were ND for all target analytes and the PQL were below the 18 AAC 75.341 Method Two Migration to Groundwater (MTG) cleanup levels. However, the lab results from the sample collected from MW-2 and its duplicate detected DRO and toluene. The toluene results were below its MTG cleanup level but the DRO results were above the MTG cleanup level of 1.5 mg/l at 2.71 mg/l and 2.85 mg/l for the duplicate. GW levels were measured below the top of casing (TOC) by RSE field personnel in monitoring wells MW-1 and MW-2 and were 3.86 feet and 2.35 feet, respectively. The GW flow is assumed to be toward Big Lake due to its proximity. The April 2009 GW sampling results for well MW-2 detected DRO, benzene, and ethylbenzene but all below their respective MTG cleanup levels. The October 2009 groundwater sampling results for well MW-2 detected DRO and toluene with toluene below its MTG cleanup level but DRO above its MTG cleanup level. The CSP is concerned that a slug of contamination from the release on your property may be headed toward Big Lake. The SGS North America Inc. (SGS) Alaska Division Level II Laboratory Data Report Case Narrative indicated that an “Unknown hydrocarbon with several peaks is present” for the AK102 GW sample and its duplicate results for monitoring well MW-2. In an email dated June 11, 2010 from RSE the CSP received copies of the chromatograms as well as an email from Mr. Homestead at SGS. He commented that the chromatograms looked like polar compounds. He asked if the samples were from a landfill. This experience was similar to the results of well MW-2 for the April 2009 groundwater sampling event. In the response to supplying the chromatogram to RSE for well MW-2 for this event, Mr. Homestead indicated that “the pattern at the end of the chromatogram [was] indicative of biogenic organics.” In discussion with the CSP chemist regarding these sampling results, without knowing more specifics about the site, his interpretation was that there appears to be biogenic interference from either a bog or septic effluent. Consequently, the next DRO analyses were requested by email to be performed using both AK 102 and silica gel methods.	Bill Petrik
8/23/2010	Document, Report, or Work plan Review - other	Reviewed the Restoration Science & Engineering (RSE) document "Environmental Site Assessment Letter Report: Summer 2010 Groundwater Monitoring at 5100 South Dottie Lou Lane in Big, Lake Alaska (ADEC File No. 2202.38.011)" dated August 2, 2010 and received 8/10/10. The 3rd round of GW sampling at the site was undertaken on 7/7/10 which included collecting GW samples from the two onsite monitoring wells, performing a GW elevation survey, and inspecting Big Lake near the release site for potential sheening. The report presents their findings. GW was measured at 4.18’ below TOC in MW MW-1 and 2.63’ below TOC in MW-2. The elevation of GW in MW-1, furthest of the two wells from the lake, is lower than the groundwater in MW-2. This is consistent with the past water level measurement episodes. The elevation of the surface of Big Lake is lower than the GW elevation in either well. RSE personnel observed the bank and surface water along the shoreline of Big Lake in the vicinity of the release and did not note any sheen. GW samples were collected from well MW-1 (labeled MW-1), well MW-2 (labeled MW-2), and one blind duplicate of well MW-2 (labeled MW-X) and submitted for lab analysis. GW sample MW-1 was submitted for lab analysis of DRO and BTEX. GW samples MW-2 and MW-X were analyzed for DRO via the AK Method 102 and additionally with silica gel cleanup, PAH, and VOCs. The analytical results for MW-1 were all ND. Considering the higher analytical results of the MW-2 sample and its duplicate MW-X, DRO was detected via the AK 102 at an estimated value of 0.813 mg/l, and toluene at an actual value of 11.5 ?g/l. By the DRO silica gel method, both results were ND. All PAH results were ND. The detected results were below their 18 AAC 75.345 Table C groundwater cleanup levels. Chromatograms for both the DRO via the AK 102 and the DRO Silica Gel analytical results for samples MW-2 and MW-X were obtained from the lab. For each sample, the chromatogram of the DRO results via AK 102 were compared to the DRO Silica Gel results. Review of these chromatograms confirmed that the irregularities in the DRO sample results were biogenic interferences. Consequently, no further DRO Silica Gel lab analysis will be required for monitoring well MW-2. The analytical results for sample MW-2 and MW-X were also compared to the ADEC Surface Water Standards under 18 AAC 70 which specify hydrocarbon standards of less than 15 ?g/l total aqueous hydrocarbons (TAqH) defined as the summation of total aromatic hydrocarbons (TAHs) and PAHs. TAqH is the summation of the VOCs benzene, ethylbenzene, toluene, and xylenes. The Surface Water Standards for TAHs is 10 ?g/l. Based on all sampling results, the TAH and TAqH for sample MW-2 is 8.46 ?g/l and for sample MW-X is 11.5 ?g/l. The consultant averaged the TAH analytical results of sample MW-2 and its duplicate, MX-2, and achieved an average value of 9.98 ?g/l which is less than the cleanup level of 10 ?g/l. The CSP policy is when a sample and its duplicate are submitted for laboratory analysis, the highest values of the two analytical results are used for regulatory purposes. Based on this policy, the TAH of the duplicate sample, 11.5 ?g/l, exceeds the Surface Water quality cleanup level of 10 ?g/l. As a result of the TAH exceedances by the latest round of sampling, the CSP still considers Big Lake to be at risk. Rather than taking a conservative approach at this time to require a new monitoring well be installed between well MW-2 and the lake, the CSP foregoes that and requests further groundwater monitoring be conducted to assess future TAH and TAqH levels. A work plan for two semi-annual samplings of MW-1 and MW-2 for DRO and BTEX analyses, including evaluation of TAH, and TAqH for MW-2 was requested in a CSP letter sent this date. In the event future groundwater sampling analytical results exceeds either the TAH or TAqH regulatory levels, a monitoring well will be requested to be installed between well MW-2 and Big Lake and further sampling of all monitoring wells.	Bill Petrik
10/12/2010	Update or Other Action	In response to an email letter received 10/4/10 from Mr. Tervooren, attorney for Mr. Wilson, requesting less frequent GW sampling and for less analytes, the CSP sent a response letter this date. The attorney letter requested a modest extension of the October 8, 2010 date by which the CSP had requested a work plan for further sampling of groundwater monitoring wells MW-1 and MW-2, elimination of monitoring the two on-site monitoring wells. The attorney letter pointed to biogenic interference as one of the reasons for eliminating further monitoring of well MW-1. A response letter by the CSP granted an extension for the work plan, and relief of sampling well MW-1 but continued sampling of well MW-2 was requested as it is located approximately 70 feet from Big Lake. Continued laboratory analysis of samples from well MW-2 was requested for DRO, TAHs, and TAqH for at least one more event to assure that contaminant levels dropped below their cleanup levels. The CSP also requested laboratory analysis of groundwater samples from well MW-2 to be performed for DRO by the Silica Gel Method in addition to by AK Method 102 in order to eliminate extraneous laboratory results due to biogenic interference for the most recent past sampling event as well as for the next event. The CSP will evaluate the site for closure after the results of the next groundwater sampling are received. The work plan was encouraged by the CSP to be submitted as soon as possible in order to obtain data prior to freeze up.	Bill Petrik
11/4/2010	Update or Other Action	Received an email from Moana Leirer of Restoration Science and Engineering regarding clarifying the CSP letter to Steve S. Tervooren (Lon Wilson’s attorney) dated 10/12/10 as to whether the CSP requested only one sample to be collected from MW-2 or a duplicate as well. Reviewed the letter and sent a response email indicating that a duplicate is also needed and it should be submitted to the lab blindly.	Bill Petrik
6/22/2011	Site Characterization Workplan Approved	On 6/22/11, DEC conditionally approved of Restoration Science & Engineering Submittal titled 2011 Groundwater Monitoring Work Plan at 5100 South Dottie Lou Lane in Big, Lake Alaska (ADEC File No. 2202.38.011) dated June 21, 2011. CSP received the subject work plan on June 21, 2011 via e-mail from RSE. The plan proposes to sample MW-2 and inspect Big Lake for possible sheening. A report will be provided to ADEC within 30 days of completion of sampling. MW-2 will be sampled for DRO with and without silica gel cleanup, and for VOCs and SVOCs to address potential water quality criteria for Total Aromatic Hydrocarbons (TAH) and for Total Aqueous Hydrocarbons (TAqH) due to spill’s close proximity to Big Lake. Also, DEC noted that in its letter to Wilson's counsel Mr. Steven Tervooren, esq. dated October 12, 2010, DEC had requested that a copy of the Emerald Alaska Inc. report of the work that they (Emerald) performed at the site for our records. DEC's 6/22 letter noted that as of yet DEC has not received this report so reiterated that request.	Rich Sundet
3/22/2012	Document, Report, or Work plan Review - other	Sent Letter regarding Review of the Restoration Science & Engineering (RSE) Submittal titled: Summer 2011 Groundwater Monitoring at 5100 South Dottie Lou Lane, in Big Lake Alaska (ADEC File No. 2202.38.011)In addition, on March 19th we briefly discussed the report and potential future steps for the site with Mr. David Nyman of RSE. The subject report noted that field sampling occurred on June 8, 2011. The report shows that groundwater results from MW-2 are below 18 AAC 75.345 cleanup levels for benzene, toluene, ethylbenzene, xylenes (BTEX), diesel range organics (DRO), polycyclic aromatic hydrocarbons (PAHs) and total aromatic hydrocarbons (TAH). The June 2011 analytical results are the following for: • Benzene concentrations ranged from non-detect (ND) to less than .0004 mg/L. • Toluene concentrations ranged from ND to less than 0.00191 mg/L. • Ethylbenzene concentrations ranged from ND to 0.002 mg/L. • Xylene concentrations ranged from ND to less than 0.002 mg/L. • DRO concentrations ranged from ND to less than 0.0005 mg/L. • PAHs concentrations ranged from ND to less than 0.0000198 mg/L. • TAH concentrations ranged from ND to 0.00196 mg/L. • Total aqueous hydrocarbons, sum of TAHs and PAHs was is 0.00203 mg/L.	Katrina Chambon
5/10/2012	Site Characterization Workplan Approved	Conditional Approval of 2012 Groundwater Monitoring Well Decommissioning Work Plan, 5100 South Dottie Lou Lane in Big Lake, Alaska (ADEC File No. 2202.38.011) RSE Project No. 12-927, dated May 3, 2012. The Alaska Department of Environmental Conservation (DEC), Contaminated Sites Program (CSP), has completed its review of the subject work plan for groundwater monitoring well decommissioning. The work plan proposes to decommission two groundwater monitoring wells. The casing will be removed from the ground; boreholes will be filled with bentonite clays to within 18 inches of the ground surface, then covered with native materials or top soil. This work plan is approved with the following condition: Complete copies of field notes need to be provided with the report. 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
6/27/2012	Exposure Tracking Model Ranking	A new updated ranking with ETM has been completed for source area 75655 300 Gallon Above Ground HHOT.	Katrina Chambon
6/29/2012	Document, Report, or Work plan Review - other	Review of 2012 Groundwater Monitoring Well Decommissioning Report, 5100 South Dottie Lou Lane in Big Lake, Alaska. Restoration Science and Engineering (RSE) decommissioned two monitoring well, historally designated MW-1 and MW-2, in accordance with ADEC remmended practices regarding monitoring well decommissioning. RSE field personnel investigated the surface of Big Lake along the entire perimeter of the subject property for the presence of sheen or other evidence of hydrocarbon impacts. No Hydrocarbon impacts were observed.	Katrina Chambon
7/6/2012	Exposure Tracking Model Ranking	A new updated ranking with ETM has been completed for source area 75655 300 Gallon Above Ground HHOT.	Katrina Chambon
7/12/2012	Cleanup Complete Determination Issued	The Alaska Department of Environmental Conservation (ADEC), Contaminated Sites Program has completed a review of the environmental records associated with Residence-5100 South Dottie Lou Lane Home Heating Oil Tank (HHOT) located at 5100 South Dottie Lou Lane, Big Lake, Alaska 99562. Based on the information provided to date, the ADEC has determined that the contaminant concentrations remaining on site do not pose an unacceptable risk to human health or the environment, and this site will be closed. In June 2007 a 300-gallon above-ground tank (AST) supply line released diesel into the cabin located on-site and diesel seeped through the flooring to the ground surface under the northwest side of the structure. It is estimated that approximately 10 to 30 gallons of diesel was released during the spill. A total of 263.77 tons of impacted soil was excavated from the site during spill response activities. Confirmation soil samples collected from the excavation at 10-12 feet below ground surface indicated diesel range organics (DRO) and benzene remained at concentrations above ADEC cleanup levels, with DRO detected up to 2,170 mg/kg and benzene detected up to 0.101 mg/kg. Groundwater was encountered in the excavation at 12 feet bgs. In March 2009 two groundwater monitoring wells, MW-1 and MW-2, were installed and sampled at the subject property. MW-1 was advanced to approximately 15 feet bgs and MW-2 was advanced to approximately 10 feet bgs. Groundwater was encountered in MW-1 at approximately 6 feet bgs with a confining layer of silt observed at approximately 12 feet bgs. Groundwater was encountered in MW-2 at approximately 9 feet bgs. Groundwater samples contained detectable concentrations of contaminants, but all analytes were below Table C cleanup levels. Soil samples collected during monitoring well installation did not contain contaminants above Method Two migration to groundwater cleanup levels. The two wells were sampled again in October 2009 and July 2010. DRO was detected in MW-2 at 8.85 mg/l during the October sampling event; however contaminants were not detected above cleanup levels in the July sampling event. The July 2010 samples were analyzed using a silica gel cleanup process to remove naturally occurring organics from the sample prior to analysis, and a review of the chromatograms from the October 2009 sampling event support the concept that naturally occurring organics were responsible for the DRO detected in the October 2009 samples. Groundwater samples were collected again in July 2011 and analyzed using silica gel cleanup. Contaminants were not detected above cleanup levels. Because of the proximity to Big Lake and because a complete pathway exists for groundwater to migrate to surface water, groundwater analytical data were also compared to 18 AAC 70 Alaska Water Quality Standards (AWQS) for total aromatic hydrocarbons (BTEX) and total aqueous hydrocarbons (BTEX + PAHs). Contaminants were not detected above AWQS.	Katrina Chambon

Action Date

Action

Description

DEC Staff

7/14/2007

Potentially Responsible Party/State Interest Letter

Letter of Interest hand delivered to Mr. Lon Wilson.

Mark Sielaff

8/8/2007

Cleanup Plan Approved

Received and approved a cleanup plan from Emerald Alaska, Inc.

Mark Sielaff

8/8/2007

Update or Other Action

A work plan from Emerald Alaska, Inc. titled "ADEC Spill Number: 07239915601 Lon Wilson Residence locateds at mile 7.9 South Big Lake Road" dated 8/8/07 was received.

Mark Sielaff

8/31/2007

Cleanup Plan Approved

A letter this date provided Emerald Alaska, Inc. written authorization to conduct the cleanup, removal, and disposal of materials contaminated by an oil or hazardous substance spill. Any soil transported from the site shall be done in a manner that prevents its dispersal en route. This letter authorizes 63 covered super sacks filled with over 63 cubic yards of contaminated gravel and soils to be transported from the site to Alaska Soils Recycling in Anchorage for thermal treatment. This letter was in response to the Emerald Wor Plan received 8/8/07.

Mark Sielaff

10/9/2007

Update or Other Action

Emerald Alaska stated that pit sidewalls were clean. Water was encountered during search for vertical limit of contamination. PID readings were "hot" at the bottom of the pit.

Mark Sielaff

10/19/2007

Site Characterization Report Approved

Requested and received initial "closure" sample results dated 10/16/07 from Emerald Alaska Inc. Sampling for GRO, DRO, RRO, and BTEX indicated that Sample BLS-1 results taken at 12' bgs in the west side if the excavation exceeded the DRO and benzene cleanup levels. The results were 1,610 mg/kg and 0.039 mg/kg, respectively. The results for sample BLS-2 taken at 10' bgs at the bottom of the southwest side of the excavation exceeded the cleanup levels for DRO, benzene, and ethylbenzene at 2,170 mg/kg, 0.101 mg/kg and 6.75 mg/kg, respectively, as well.

Mark Sielaff

10/23/2007

Offsite Soil or Groundwater Disposal Approved

Jim Rogers of Alaska Soil Recycling was contacted and indicated that 226 super sacks of contaminated soil weighing 263.77 tons was received from the site.

Mark Sielaff

11/2/2007

Meeting or Teleconference Held

A meeting was held to discuss the site status. In attendance were Mark Sielaff and John Brown of ADEC/PERP, Rich Sundet of ADEC/CSP, Blake Hillis and Mike High of Emerald Alaska, Lon Wilson the landowner, Steven Tervooren, RP attorney, and David Nyman of Restoration Science and Engineering. Both the PERP and the CSP discussed their positions. Site was transferred from PERPS to CSP and Emerlad was relieved of their services.

Mark Sielaff

11/2/2007

Spill Transferred from Prevention Preparedness and Response Program

Site transferred by PERP staff Mark Sielaff. Spill No. 07239915601; Spill Date 6/5/07; CATS No. 07-0119-10; Substance = Diesel; Quantity = ~30 Gallons; Spill Name = Lon Wilson Heating Oil Tank Spill Big Lake, AK. To date, 226 super sacks representing 264 tons of contaminated soil has been transported to Alaska Soils Recycling awaiting thermal treatment.

Mark Sielaff

11/8/2007

Update or Other Action

PERP received a copy of the Restoration Science & Engineering "Spill Cleanup Report Lot 11, Linda Scott Subdivision, 5100 Dottie Lou Lane, Big, Lake, Alaska (ADEC Spill Report No: 072399156001)" dated 11/5/07.

Mark Sielaff

11/13/2007

Update or Other Action

Sent an email to Rich Sundet of the CSP indicating that Emerald Alaska, Inc. was relieved of their cleanup obligations by Lon Wilson and replaced with David Nyman of Restoration Science and Engineering.

Mark Sielaff

12/8/2007

Site Characterization Report Approved

Received an email with an attached Restoration Science and Engineering (RSE) report titled "Additional Cleanup and Sampling November 5, 2007; Lot 11, Linda Scott Subdivision, 5100 S Dottie Lou Lane, Big Lake, Alaska (ADEC Spill Report No: 072399156001)" dated 12/5/07 containing second site sample results. RSE redug contaminated soil on 11/5/07 and found the southwest and its duplicate sample for DRO, RRO and BTEX to be within cleanup levels. RSE augered into a vein of gravel on the west side of the excavation which the contamination followed horizontally and found very high levels of contamination. The west side excavation samples from 12' deep resulted in exceedances of the cleanup levels for DRO at 3,080 mg/kg and benzene at 0.0409 mg/kg.

Mark Sielaff

12/10/2007

Update or Other Action

Requested what the future intentions of site work were to Lon Wilson.

Mark Sielaff

12/13/2007

Update or Other Action

In response to an email to Lon Wilson dated 12/10/2007 as to future intentions of site work, the PERP received a letter dated both 12/12/07 and 12/13/07 from Mr. Tervooren, attorney, requesting site closure based on de minimus soil residue.

Mark Sielaff

3/13/2008

Site Added to Database

Site added to the database.

Mitzi Read

3/13/2008

Exposure Tracking Model Ranking

Initial ranking with ETM completed.

Mitzi Read

9/17/2008

Site Characterization Report Approved

The Contaminated Sites Program (CSP) performed a review of the Restoration Science & Engineering "Spill Cleanup Report Lot 11, Linda Scott Subdivision, 5100 Dottie Lou Lane, Big, Lake, Alaska (ADEC Spill Report No: 072399156001)" dated November 5, 2007 and "Additional Cleanup and Sampling November 5, 2007; Lot 11, Linda Scott Subdivision, 5100 S Dottie Lou Lane, Big Lake, Alaska (ADEC Spill Report No: 072399156001)" dated December 5, 2007. This site is located within 185 feet of Big Lake. The release of approximately 30 gallons of home heating fuel from an approximate 300-gallon aboveground storage tank (AST) was discovered on June 6, 2007. Approximately 176 cubic yards of hydrocarbon-impacted soil were removed from the spill source area and transported to Alaska Soil Recycling, Inc. (ASR) in Anchorage for thermal treatment. Analytical soil sampling results indicated diesel-range organics (DRO), benzene, and ethylbenzene levels above the 18 AAC 75.341 Method 2 cleanup levels. Analytical ground water sampling results indicated DRO, RRO, and benzene levels above the 18 AAC 75.345 Table C Cleanup Levels. A letter from the CSP was sent this date in response to the review of the report and requested a work plan outlining further soil and ground water characterization and sampling in the fall of 2008 for DRO, gasoline-range organics (GRO), RRO, and benzene, toluene, ethylbenzene, and total xylenes (collectively referred to as BTEX). The responsible party was asked to account for prior investigative derived soil and groundwater waste. A Conceptual Site Model was lacking in the report and requested along with the work plan. (Petrik)

Bill Petrik

9/25/2008

Update or Other Action

Contacted Mr. Richard Anderson via telephone this date to inform him that per the Contaminated Sites Program (CSP) protocol the CSP is planning on sending a Potentially Responsible Party (PRP) letter to him. In the conversation, Mr. Anderson indicated that in no way was he accepting responsibility for the spill and he subsequently is in the process of litigation regarding this issue. He will accept the letter knowing that it is a formality as a part of the CSP doing their job.

Bill Petrik

11/5/2008

Potentially Responsible Party/State Interest Letter

The Contaminated Sites Program (CSP) completed a Potentially Responsible Party Letter for the site and sent it certified mail, return receipt requested to the owner of a contracting company along with an "ADEC INFORMATION REQUEST, Concerning a Contaminated Site(s)", and an ADEC "Cleanup Process, Cleanup of Contaminated Sites in Alaska" pamphlet. The site has contaminated soil and/or water associated with a home heating oil aboveground storage tank (AST) release that was located on the property when the fuel line was severed between the AST and the residence by a contracting company staff.

Bill Petrik

11/20/2008

Site Characterization Workplan Approved

The Contaminated Site Program (CSP) completed a review of the Restoration Science & Engineering (RSE) document "Site Investigation Workplan: Installation of Monitoring Wells and Soil Borings at Lot 11, Linda Scott Subdivision near Big, Lake, Alaska" dated November 11, 2008. A letter was sent conditionally approving the work plan. The site experienced an estimated release of 10-30 gallons of home heating oil fuel and further work is needed. Two borings are proposed to be drilled down gradient and sampled for GRO, DRO, and BTEX as an attempt to determine the vertical and lateral extent of the contamination. Groundwater is contaminated and the two proposed borings are planned to be finished as monitoring wells and sampled for GRO, DRO, and BTEX as well. Polycyclic aromatic hydrocarbons (PAH) will be added to the analytical testing for soil and groundwater if the sum of the hydrocarbons in the resulting analytical soil results exceeds 500 mg/kg. Total aromatic hydrocarbons (TAH) and total aqueous hydrocarbons (TAqH) groundwater sampling and analysis is also planned, as the site is within 150 feet of Big Lake. A Conceptual Site Model has not previously been submitted and was requested with the report of findings resulting from this work plan. A site characterization report will be submitted after completion of proposed work tasks and submitted to the ADEC for review within 60 days from the conclusion of sampling.

Bill Petrik

2/10/2009

Update or Other Action

In a letter dated 2/10/09, the Contaminated Sites Program responded to Mr. Wilkens' letter dated November 20, 2008 to Mr. Bill Petrik of the Department’s Contaminated Site staff concerning the liability of your client Mr. Richard Anderson dba Complete Painting & Etc.

Rich Sundet

3/3/2009

Update or Other Action

In response to the subpoenas received on 1/28/09 at the request of James Wilkens (representing Richard Anderson dba Complete Painting & Etc.), on 3/3/09 Rich Sundet of the CSP and Mark Sielaff of the PERP gave depositions. Attending the depositions were Lon Wilson and his counsel, counsel for Tim Clemmer dba Clemmer Construction, Wilkens, and Tostevin of the Attorney General's Office.

Rich Sundet

8/17/2009

Document, Report, or Work plan Review - other

Reviewed a copy of the Restoration Science & Engineering "Environmental Site Assessment Letter Report: Installation of Groundwater Monitoring Wells at 5100 South Dottie Lou Lane in Big Lake Alaska (ADEC File No. 2202.38.011)" dated 6/4/09, received 8/11/09. On March 19, 2009, two groundwater monitoring wells, MW-1 and MW-2, were installed at the subject property. MW-1 is approximately 70 feet northwest of the house and MW-2 is approximately 130 feet northwest of it. It is approximately 70 feet from MW-2 to the shore of Big Lake. After screening soil during drilling, two samples and one duplicate were collected and submitted for laboratory analysis of diesel-range organics (DRO), gasoline range-organics (GRO) and benzene, toluene, ethylbenzene and total xylenes (collectively referred to as BTEX) and polynuclear aromatic hydrocarbons (PAH). Generally, a soil sample was collected and analyzed from the highest PID field-screened sample interval, which was at the soil/water interface for each monitoring well. The soil sample collected from MW-2 and the duplicate of the sample from MW-1 did not detect any target analytes. The original sample from MW-1 exhibited concentrations of GRO, DRO, and total xylenes at 0.813 milligrams per kilogram (mg/kg), 14.1 mg/kg, and 0.0245 mg/kg which were all laboratory estimates. These values are considerably below the ADEC 18 AAC 75 Table B1 Method Two soil cleanup levels of 300 mg/kg, 250 mg/kg, and 63 mg/kg, respectively. During drilling on March 19, 2009, groundwater was encountered in MW-1 at approximately six feet below the ground surface (bgs) with a confining layer of silt initially observed at approximately 10 feet bgs and continuing to at least the bottom of the boring. Groundwater was initially encountered in MW-2 at approximately nine feet bgs but rose to 2 feet bgs after drilling, above the screened interval, which was from 5-10 feet bgs. Due to cold conditions, sampling of the wells did not occur on the date of drilling. On April 16, 2009, RSE conducted groundwater sampling from both wells including a duplicate and submitted them for laboratory analysis for DRO, GRO, and BTEX. Groundwater samples MW-1 and MW-3 (duplicate of MW-1) were also analyzed for PAHs. There were detections of some target analytes in all groundwater samples. Groundwater sample MW-2 exhibited concentrations of DRO at 0.519 mg/L, GRO at 0.0204 mg/l, and toluene at 0.00492 mg/L. The maximum detected values of sample results from MW-1 and its duplicate MW-3 were DRO at 0.292 mg/l, GRO at 0.0138 mg/l, and total xylenes at 0.000631 mg/l. Groundwater sample results were compared to the ADEC 18 AAC 75 Table C groundwater cleanup levels and the detections were all below the Table C cleanup levels of 1.5 mg/l for DRO, 2.2 mg/l for GRO, 1 mg/l for toluene, and 10 mg/l for total xylenes. All other groundwater samples exhibited non-detectable (ND) concentrations of target analytes for DRO, GRO, BTEX, and PAHs. Based on the analytical soil and groundwater sampling results the investigative derived soil and groundwater waste may be disposed on site provided its disposal complies with 18 AAC 75.370. In particular, (2)(A) states “100 feet or more from surface water, a private water system, a Class C public water system as defined in 18 AAC 80.1990, or a fresh water supply system that uses groundwater for a use designated in 18 AAC 70.020(a)(1)(A) and 18 AAC 70.050(a)(2)”. In addition, the area of disposal shall not be an environmentally sensitive area such as wetlands or subject to runoff to a surface water body. Numerous items requested in the CSP letter dated November 21, 2008 conditionally approving the work plan for the most recently completed work are lacking or not reported. They include: • Development of a CSM and summaries of soil and groundwater data relative to risk pathways; • The ice surface elevation was measured in the latest site work as a third water level surface as part of the calculation of groundwater gradient and flow direction. This task was contrary to the CSP work plan request to use the water surface and not the ice surface. • During each groundwater sampling event, a visual site inspection of Big Lake downhill from the site shall occur and a finding of inspections of Big Lake for possible sheening downhill from the site. • Calculation of the groundwater flow gradient and direction. • Sampling at least twice after the initial sampling event.

Bill Petrik

10/15/2009

Document, Report, or Work plan Review - other

A letter was sent to the RP after review of the Restoration Science & Engineering Documents "Environmental Site Assessment Letter Report: Installation of Groundwater Monitoring Wells at 5100 South Dottie Lou Lane in Big, Lake Alaska (ADEC File No. 2202.38.011)" dated June 4, 2009 and received 8/11/09, and "Questions on and Corrections to Environmental Site Assessment Letter Report: Installation of Groundwater Monitoring Wells at 5100 South Dottie Lou Lane in Big, Lake Alaska" dated September 22, 2009, received 10/1/09. The letter requested: two further sampling events, one to occur in Fall 2009 and the second in Spring 2010; that the work be done when the lake is ice free or when there are no issues with freeze-up or break-up to minimize any interpretation these events may have upon determining normal hydraulic conditions; submittal of a CSM and summaries of soil and groundwater data relative to risk pathways; measure the elevation of the water surface instead of the ice surface as part of the calculation of groundwater gradient and flow direction; during each groundwater sampling event make a visual site inspection of Big Lake downhill from the site for possible sheening from the site; calculation of the GW flow gradient and direction; and GW sampling at least twice more. Ensure that the items outlined above that are missing in the subject reports are addressed and included in the report for the next sampling. Please submit the report for the next sampling within 60 days of receiving the laboratory sampling results report.

Bill Petrik

6/18/2010

Document, Report, or Work plan Review - other

Reviewed a copy of the Restoration Science & Engineering (RSE) "Environmental Site Assessment Letter Report: Fall 2009 Groundwater Monitoring at 5100 Dottie Lou Lane in Big Lake Alaska (ADEC File No. 2201.38.011)" dated 12/16/09 received 2/11/10. On 10/29/09, RSE field personnel measured the depth to GW and collected GW samples from MWs MW-1 and MW-2. MW-2 is the well closest to Big Lake. Two samples and one duplicate of MW-2 were collected and submitted for laboratory analysis of DRO and BTEX. The analytical results for the sample from MW-1 were ND for all target analytes and the PQL were below the 18 AAC 75.341 Method Two Migration to Groundwater (MTG) cleanup levels. However, the lab results from the sample collected from MW-2 and its duplicate detected DRO and toluene. The toluene results were below its MTG cleanup level but the DRO results were above the MTG cleanup level of 1.5 mg/l at 2.71 mg/l and 2.85 mg/l for the duplicate. GW levels were measured below the top of casing (TOC) by RSE field personnel in monitoring wells MW-1 and MW-2 and were 3.86 feet and 2.35 feet, respectively. The GW flow is assumed to be toward Big Lake due to its proximity. The April 2009 GW sampling results for well MW-2 detected DRO, benzene, and ethylbenzene but all below their respective MTG cleanup levels. The October 2009 groundwater sampling results for well MW-2 detected DRO and toluene with toluene below its MTG cleanup level but DRO above its MTG cleanup level. The CSP is concerned that a slug of contamination from the release on your property may be headed toward Big Lake. The SGS North America Inc. (SGS) Alaska Division Level II Laboratory Data Report Case Narrative indicated that an “Unknown hydrocarbon with several peaks is present” for the AK102 GW sample and its duplicate results for monitoring well MW-2. In an email dated June 11, 2010 from RSE the CSP received copies of the chromatograms as well as an email from Mr. Homestead at SGS. He commented that the chromatograms looked like polar compounds. He asked if the samples were from a landfill. This experience was similar to the results of well MW-2 for the April 2009 groundwater sampling event. In the response to supplying the chromatogram to RSE for well MW-2 for this event, Mr. Homestead indicated that “the pattern at the end of the chromatogram [was] indicative of biogenic organics.” In discussion with the CSP chemist regarding these sampling results, without knowing more specifics about the site, his interpretation was that there appears to be biogenic interference from either a bog or septic effluent. Consequently, the next DRO analyses were requested by email to be performed using both AK 102 and silica gel methods.

Bill Petrik

8/23/2010

Document, Report, or Work plan Review - other

Reviewed the Restoration Science & Engineering (RSE) document "Environmental Site Assessment Letter Report: Summer 2010 Groundwater Monitoring at 5100 South Dottie Lou Lane in Big, Lake Alaska (ADEC File No. 2202.38.011)" dated August 2, 2010 and received 8/10/10. The 3rd round of GW sampling at the site was undertaken on 7/7/10 which included collecting GW samples from the two onsite monitoring wells, performing a GW elevation survey, and inspecting Big Lake near the release site for potential sheening. The report presents their findings. GW was measured at 4.18’ below TOC in MW MW-1 and 2.63’ below TOC in MW-2. The elevation of GW in MW-1, furthest of the two wells from the lake, is lower than the groundwater in MW-2. This is consistent with the past water level measurement episodes. The elevation of the surface of Big Lake is lower than the GW elevation in either well. RSE personnel observed the bank and surface water along the shoreline of Big Lake in the vicinity of the release and did not note any sheen. GW samples were collected from well MW-1 (labeled MW-1), well MW-2 (labeled MW-2), and one blind duplicate of well MW-2 (labeled MW-X) and submitted for lab analysis. GW sample MW-1 was submitted for lab analysis of DRO and BTEX. GW samples MW-2 and MW-X were analyzed for DRO via the AK Method 102 and additionally with silica gel cleanup, PAH, and VOCs. The analytical results for MW-1 were all ND. Considering the higher analytical results of the MW-2 sample and its duplicate MW-X, DRO was detected via the AK 102 at an estimated value of 0.813 mg/l, and toluene at an actual value of 11.5 ?g/l. By the DRO silica gel method, both results were ND. All PAH results were ND. The detected results were below their 18 AAC 75.345 Table C groundwater cleanup levels. Chromatograms for both the DRO via the AK 102 and the DRO Silica Gel analytical results for samples MW-2 and MW-X were obtained from the lab. For each sample, the chromatogram of the DRO results via AK 102 were compared to the DRO Silica Gel results. Review of these chromatograms confirmed that the irregularities in the DRO sample results were biogenic interferences. Consequently, no further DRO Silica Gel lab analysis will be required for monitoring well MW-2. The analytical results for sample MW-2 and MW-X were also compared to the ADEC Surface Water Standards under 18 AAC 70 which specify hydrocarbon standards of less than 15 ?g/l total aqueous hydrocarbons (TAqH) defined as the summation of total aromatic hydrocarbons (TAHs) and PAHs. TAqH is the summation of the VOCs benzene, ethylbenzene, toluene, and xylenes. The Surface Water Standards for TAHs is 10 ?g/l. Based on all sampling results, the TAH and TAqH for sample MW-2 is 8.46 ?g/l and for sample MW-X is 11.5 ?g/l. The consultant averaged the TAH analytical results of sample MW-2 and its duplicate, MX-2, and achieved an average value of 9.98 ?g/l which is less than the cleanup level of 10 ?g/l. The CSP policy is when a sample and its duplicate are submitted for laboratory analysis, the highest values of the two analytical results are used for regulatory purposes. Based on this policy, the TAH of the duplicate sample, 11.5 ?g/l, exceeds the Surface Water quality cleanup level of 10 ?g/l. As a result of the TAH exceedances by the latest round of sampling, the CSP still considers Big Lake to be at risk. Rather than taking a conservative approach at this time to require a new monitoring well be installed between well MW-2 and the lake, the CSP foregoes that and requests further groundwater monitoring be conducted to assess future TAH and TAqH levels. A work plan for two semi-annual samplings of MW-1 and MW-2 for DRO and BTEX analyses, including evaluation of TAH, and TAqH for MW-2 was requested in a CSP letter sent this date. In the event future groundwater sampling analytical results exceeds either the TAH or TAqH regulatory levels, a monitoring well will be requested to be installed between well MW-2 and Big Lake and further sampling of all monitoring wells.

Bill Petrik

10/12/2010

Update or Other Action

In response to an email letter received 10/4/10 from Mr. Tervooren, attorney for Mr. Wilson, requesting less frequent GW sampling and for less analytes, the CSP sent a response letter this date. The attorney letter requested a modest extension of the October 8, 2010 date by which the CSP had requested a work plan for further sampling of groundwater monitoring wells MW-1 and MW-2, elimination of monitoring the two on-site monitoring wells. The attorney letter pointed to biogenic interference as one of the reasons for eliminating further monitoring of well MW-1. A response letter by the CSP granted an extension for the work plan, and relief of sampling well MW-1 but continued sampling of well MW-2 was requested as it is located approximately 70 feet from Big Lake. Continued laboratory analysis of samples from well MW-2 was requested for DRO, TAHs, and TAqH for at least one more event to assure that contaminant levels dropped below their cleanup levels. The CSP also requested laboratory analysis of groundwater samples from well MW-2 to be performed for DRO by the Silica Gel Method in addition to by AK Method 102 in order to eliminate extraneous laboratory results due to biogenic interference for the most recent past sampling event as well as for the next event. The CSP will evaluate the site for closure after the results of the next groundwater sampling are received. The work plan was encouraged by the CSP to be submitted as soon as possible in order to obtain data prior to freeze up.

Bill Petrik

11/4/2010

Update or Other Action

Received an email from Moana Leirer of Restoration Science and Engineering regarding clarifying the CSP letter to Steve S. Tervooren (Lon Wilson’s attorney) dated 10/12/10 as to whether the CSP requested only one sample to be collected from MW-2 or a duplicate as well. Reviewed the letter and sent a response email indicating that a duplicate is also needed and it should be submitted to the lab blindly.

Bill Petrik

6/22/2011

Site Characterization Workplan Approved

On 6/22/11, DEC conditionally approved of Restoration Science & Engineering Submittal titled 2011 Groundwater Monitoring Work Plan at 5100 South Dottie Lou Lane in Big, Lake Alaska (ADEC File No. 2202.38.011) dated June 21, 2011. CSP received the subject work plan on June 21, 2011 via e-mail from RSE. The plan proposes to sample MW-2 and inspect Big Lake for possible sheening. A report will be provided to ADEC within 30 days of completion of sampling. MW-2 will be sampled for DRO with and without silica gel cleanup, and for VOCs and SVOCs to address potential water quality criteria for Total Aromatic Hydrocarbons (TAH) and for Total Aqueous Hydrocarbons (TAqH) due to spill’s close proximity to Big Lake. Also, DEC noted that in its letter to Wilson's counsel Mr. Steven Tervooren, esq. dated October 12, 2010, DEC had requested that a copy of the Emerald Alaska Inc. report of the work that they (Emerald) performed at the site for our records. DEC's 6/22 letter noted that as of yet DEC has not received this report so reiterated that request.

Rich Sundet

3/22/2012

Document, Report, or Work plan Review - other

Sent Letter regarding Review of the Restoration Science & Engineering (RSE) Submittal titled: Summer 2011 Groundwater Monitoring at 5100 South Dottie Lou Lane, in Big Lake Alaska (ADEC File No. 2202.38.011)In addition, on March 19th we briefly discussed the report and potential future steps for the site with Mr. David Nyman of RSE. The subject report noted that field sampling occurred on June 8, 2011. The report shows that groundwater results from MW-2 are below 18 AAC 75.345 cleanup levels for benzene, toluene, ethylbenzene, xylenes (BTEX), diesel range organics (DRO), polycyclic aromatic hydrocarbons (PAHs) and total aromatic hydrocarbons (TAH). The June 2011 analytical results are the following for: • Benzene concentrations ranged from non-detect (ND) to less than .0004 mg/L. • Toluene concentrations ranged from ND to less than 0.00191 mg/L. • Ethylbenzene concentrations ranged from ND to 0.002 mg/L. • Xylene concentrations ranged from ND to less than 0.002 mg/L. • DRO concentrations ranged from ND to less than 0.0005 mg/L. • PAHs concentrations ranged from ND to less than 0.0000198 mg/L. • TAH concentrations ranged from ND to 0.00196 mg/L. • Total aqueous hydrocarbons, sum of TAHs and PAHs was is 0.00203 mg/L.

Katrina Chambon

5/10/2012

Site Characterization Workplan Approved

Conditional Approval of 2012 Groundwater Monitoring Well Decommissioning Work Plan, 5100 South Dottie Lou Lane in Big Lake, Alaska (ADEC File No. 2202.38.011) RSE Project No. 12-927, dated May 3, 2012. The Alaska Department of Environmental Conservation (DEC), Contaminated Sites Program (CSP), has completed its review of the subject work plan for groundwater monitoring well decommissioning. The work plan proposes to decommission two groundwater monitoring wells. The casing will be removed from the ground; boreholes will be filled with bentonite clays to within 18 inches of the ground surface, then covered with native materials or top soil. This work plan is approved with the following condition: Complete copies of field notes need to be provided with the report. 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

6/27/2012

Exposure Tracking Model Ranking

A new updated ranking with ETM has been completed for source area 75655 300 Gallon Above Ground HHOT.

Katrina Chambon

6/29/2012

Document, Report, or Work plan Review - other

Review of 2012 Groundwater Monitoring Well Decommissioning Report, 5100 South Dottie Lou Lane in Big Lake, Alaska. Restoration Science and Engineering (RSE) decommissioned two monitoring well, historally designated MW-1 and MW-2, in accordance with ADEC remmended practices regarding monitoring well decommissioning. RSE field personnel investigated the surface of Big Lake along the entire perimeter of the subject property for the presence of sheen or other evidence of hydrocarbon impacts. No Hydrocarbon impacts were observed.

Katrina Chambon

7/6/2012

Exposure Tracking Model Ranking

A new updated ranking with ETM has been completed for source area 75655 300 Gallon Above Ground HHOT.

Katrina Chambon

7/12/2012

Cleanup Complete Determination Issued

The Alaska Department of Environmental Conservation (ADEC), Contaminated Sites Program has completed a review of the environmental records associated with Residence-5100 South Dottie Lou Lane Home Heating Oil Tank (HHOT) located at 5100 South Dottie Lou Lane, Big Lake, Alaska 99562. Based on the information provided to date, the ADEC has determined that the contaminant concentrations remaining on site do not pose an unacceptable risk to human health or the environment, and this site will be closed. In June 2007 a 300-gallon above-ground tank (AST) supply line released diesel into the cabin located on-site and diesel seeped through the flooring to the ground surface under the northwest side of the structure. It is estimated that approximately 10 to 30 gallons of diesel was released during the spill. A total of 263.77 tons of impacted soil was excavated from the site during spill response activities. Confirmation soil samples collected from the excavation at 10-12 feet below ground surface indicated diesel range organics (DRO) and benzene remained at concentrations above ADEC cleanup levels, with DRO detected up to 2,170 mg/kg and benzene detected up to 0.101 mg/kg. Groundwater was encountered in the excavation at 12 feet bgs. In March 2009 two groundwater monitoring wells, MW-1 and MW-2, were installed and sampled at the subject property. MW-1 was advanced to approximately 15 feet bgs and MW-2 was advanced to approximately 10 feet bgs. Groundwater was encountered in MW-1 at approximately 6 feet bgs with a confining layer of silt observed at approximately 12 feet bgs. Groundwater was encountered in MW-2 at approximately 9 feet bgs. Groundwater samples contained detectable concentrations of contaminants, but all analytes were below Table C cleanup levels. Soil samples collected during monitoring well installation did not contain contaminants above Method Two migration to groundwater cleanup levels. The two wells were sampled again in October 2009 and July 2010. DRO was detected in MW-2 at 8.85 mg/l during the October sampling event; however contaminants were not detected above cleanup levels in the July sampling event. The July 2010 samples were analyzed using a silica gel cleanup process to remove naturally occurring organics from the sample prior to analysis, and a review of the chromatograms from the October 2009 sampling event support the concept that naturally occurring organics were responsible for the DRO detected in the October 2009 samples. Groundwater samples were collected again in July 2011 and analyzed using silica gel cleanup. Contaminants were not detected above cleanup levels. Because of the proximity to Big Lake and because a complete pathway exists for groundwater to migrate to surface water, groundwater analytical data were also compared to 18 AAC 70 Alaska Water Quality Standards (AWQS) for total aromatic hydrocarbons (BTEX) and total aqueous hydrocarbons (BTEX + PAHs). Contaminants were not detected above AWQS.

Katrina Chambon

Contaminant Information

Name	Level Description	Media	Comments
DRO	< Table C	Groundwater
DRO	Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation	Soil	Soil contamination remains above migration to groundwater cleanup levels; however, ground water contaminant concentrations are below 18 AAC 75.345 ADEC Table C cleanup levels.
Benzene	< Table C	Groundwater
Benzene	Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation	Soil
Ethylbenzene	< Method 2 Most Stringent	Soil
RRO	< Table C	Groundwater
RRO	< Method 2 Most Stringent	Soil

Name

Level Description

Media

Comments

DRO

< Table C

Groundwater

DRO

Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation

Soil

Soil contamination remains above migration to groundwater cleanup levels; however, ground water contaminant concentrations are below 18 AAC 75.345 ADEC Table C cleanup levels.

Benzene

< Table C

Groundwater

Benzene

Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation

Soil

Ethylbenzene

< Method 2 Most Stringent

Soil

RRO

< Table C

Groundwater

RRO

< Method 2 Most Stringent

Soil

Control Type

Type	Details
No ICs Required

Type

Details

No ICs Required

Requirements

Description	Details
Advance approval required to transport soil or groundwater off-site.

Description

Details

Advance approval required to transport soil or groundwater off-site.

ROD Dottie Lou Lane HHOT

No associated sites were found.

Missing Location Data

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Site Report: Residence - 5100 South Dottie Lou Lane HHOT

Site Chronology

IC / Closure Details

Documents

Associated Sites

Problems/Comments

Action Information

Contaminant Information

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Requirements

ROD Dottie Lou Lane HHOT

Missing Location Data

State of Alaska Department of Environmental Conservation