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Site Report: Former Williams Express Store #5021

Site Name: Former Williams Express Store #5021
Address: 6010 Old Seward Hwy, Anchorage, AK 99518
File Number: 2100.26.030
Hazard ID: 24042
Status: Active
Staff: Janice Wiegers, 9074512127 janice.wiegers@alaska.gov
Latitude: 61.166108
Longitude: -149.868811
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

This location was included in the Compliance Order by Consent (COBC). At least 17 underground storage tanks (USTs) have been in use at or near this former Williams store since the late 1950s. The earliest formal records of onsite tanks include four USTs that were installed in 1975. The current UST array was installed in 2014 A detailed site history is presented in Shannon & Wilson's December 2003 Site Summary report. Vapor extraction and pump and treat remediation systems were installed in December 1990 and October 1991, respectively and operated for a number of years. however both of these systems have since been decommissioned and the site is in the long term monitoring phase. Groundwater contamination is present at the site and has impacted off-property areas to the north and southwest. Groundwater is located at approximately 21.5 to 27.5 feet below ground surface.

Action Information

Action Date Action Description DEC Staff
1/4/1990 Leaking Underground Storage Tank Release Confirmed - Petroleum LUST Site created in CSP for source area ID 77717 ADD; gasoline contamination. Former Staff
1/4/1990 Site Added to Database Former Staff
1/5/1990 Leaking Underground Storage Tank Cleanup Initiated - Petroleum LCAU; :LCAU Date changed DB conversion Former Staff
7/20/1990 Update or Other Action AWS; Steven Tweed has given Mapco permission to add a "stub" to his property off main line extension, but not hook up completely yet. Former Staff
7/24/1990 Update or Other Action AWS; The resident at 323 Pearl Drive (Steve Tweed) was made an offer to be hooked up to city water free of charge in exchange for abandoning his drinking well. He refused and says his well tests clean at this time. Former Staff
7/25/1990 Update or Other Action AWS; DEC recommended to Mr. Tweed that people should connect to Municipal water supply. This is based on the potential for contaminants to migrate and effect wells in the future. Former Staff
8/15/1990 Update or Other Action F; Mapco issued a public notice in the Anchorage Times, stating their intent to treat the soil & groundwater containing gasoline hydrocarbons at store #5021. Former Staff
12/11/1990 Update or Other Action F; Letter sent responding to phase 1 remediation report. Requested more information on vapor extraction system design, free product measurements and free product recovery efforts. Former Staff
12/13/1990 Long Term Monitoring Established MS; Letter sent requesting that 2 more monitoring wells in addition to proposed wells be installed. Need a response by 12/21/90. Former Staff
1/8/1991 Update or Other Action F; Hartcrowser sent in vapor extraction system report for 1/8/91 thru 2/26/91. 1/8 thermal oxidizer used to treat vapors extracted from the soils. A 99.9% reduction of petroleum hydrocarbons & 99.8% reduction of benzene was realized when it was used. 994 gallons of gasoline estimated to be removed during this time period & 1616 gal. of gasoline removed since 12/17/90. Former Staff
1/14/1991 Update or Other Action F; Mapco letter states that vapor extraction started 12/17/90 with interim report on their remediation efforts to be sent by 1/17/91. Status report 12/17/90 - 1/8/91 received 1/18/91. No detectable chlorinated solvents detected in vapor, equivalent of 668 gallons of gasoline (estimated) have been removed. OSHA PEL for benzene in vapor off site has been met. Former Staff
2/27/1991 Update or Other Action F; Hartcrowser sent in vapor extraction system operation report for 2/27/91 thru 4/1/91. Estimated hydrocarbon recovery for system since startup on 12/17/90 is 1997 gallons of gas based on gram molecular weight of 100 gram/mole. The thermal oxidizer removes 99.8% of the petroleum hydrocarbons from extracted vapors. Air quality without the oxidizer operating showed a level of 9.5 ppm V benzene much less than 65 ppm V as stated in the remedial action plan. Former Staff
3/19/1991 Long Term Monitoring Established MS; Shannon & Wilson groundwater monitoring results received for March '91 sampling round. No TPH or BTEX levels were encountered in groundwater samples B4MWW4 thru B6MWW4. Flow of the groundwater is still west to northwest. Former Staff
4/1/1991 Update or Other Action F; Received Hart Crowser's vapor extraction report. Hydrocarbon recovery from 4/1/91 to 7/1/91 is estimated to be 1,494 gallons of gasoline. BTEX & VPH levels in flow gas appears to have increased from 923 ppm & 2360 ppm, respectively on 5/6/91 to 1,494 ppm & 5,510 ppm respectively on 7/1/91. Reason given is falling water elevations which may have exposed previously unremediated regions of the soil, & to the fact that the system was shut down for the first 3 weeks in June 91. Former Staff
4/12/1991 Institutional Control Record Established Date of Compliance order by Consent. Keather McLoone
6/12/1991 Long Term Monitoring Established MS; Received Hart Crowser's Vapor Extractoin results from June '91. BTEX was detected in every well on and around property, except at MW-6 (upgradient from the site). MW-5 (another upgradient well) had .007 ppm total BTEX. Offsite monitoring well 2 had BTEX; MW-9 had 51.3 ppm BTEX; & MW-8A had 0.044ppm BTEX. Inferred total BTEX is similar to those previously reported at this site. Former Staff
10/1/1991 Update or Other Action RAU; Mapco reports that the groundwater pump and treat (P&T) system began operating on October 1, 1991. Soil VES has been operating for some time. Former Staff
2/13/1992 Leaking Underground Storage Tank Corrective Action Underway LCAR; Quarterly reports for Mapco Store #5021 were submitted on August 12, 1991, November 13, 1991 and February 13, 1992. An interim report (letter) was submitted on February 20, 1992 stating that an off-site drinking water well (no longer in use) has been connected to the water treatment system. The vapor extraction system continues to run. Additional information and a plan for groundwater investigation to the west northwest of the site were requested by May 15. Former Staff
5/14/1992 Leaking Underground Storage Tank Corrective Action Underway LCAR; Soil vapor extraction and groundwater pump and treat systems continue to operate. Mapco reports that approximately 2,450 gallons of hydrocarbons have been recovered to date. Former Staff
9/9/1992 Release Investigation RELR; Approved suspension of sampling of wells #5, 6, 7, 11, 13, 14, 15, 16, 17. Further review required before abandonment. Former Staff
8/30/1994 Leaking Underground Storage Tank Corrective Action Underway LCAR; Former Staff
10/23/1994 Leaking Underground Storage Tank Corrective Action Underway LCAR; Performed a Corrective Action Report review. Former Staff
11/22/1994 Leaking Underground Storage Tank Corrective Action Underway LCAR; Review monitoring well report. Former Staff
2/6/1995 Release Investigation RELR; Reviewed site assessment. Former Staff
3/18/1995 Leaking Underground Storage Tank Corrective Action Underway LCAR; Reviewed quarterly reports. Former Staff
7/25/1995 Update or Other Action CAPR; Met with RP to discuss status of site. Former Staff
8/15/1995 Leaking Underground Storage Tank Corrective Action Underway LCAR; Reviewed quarterly monitor well report required by COBC. Former Staff
10/3/1995 Update or Other Action CAPR; Reviewed a corrective action plan at the request of the new lessor. Former Staff
11/28/1995 Update or Other Action CAPR; BOSTA meeting. Reviewed file-to-date for financial assistance request. Former Staff
11/20/1997 Update or Other Action ADEC sends Notification of Intent to Cost Recover Letter to Current Owner: TESORO ALASKA PETROLEUM CO Former Staff
9/17/2001 Update or Other Action Changed ADEC Project Manager from Bush to Wiegers Cynthia Pring-Ham
11/13/2002 Update or Other Action Fall monitoring report submitted. Groundwater samples were collected from 14 of the 17 monitoring wells. The highest concentrations were found in B5MW (170 ppm GRO, 0.8 ppm DRO, 99.8 ppm total BTEX). BTEX/GRO were not detected in vapor samples collected from the SVE. MW-12 and B12MW were decommissioned in July, 2002. Groundwater flow direction was found to be to the west to southwest south of Dowling road and west to northwest north of Dowling road. Janice Wiegers
3/11/2003 Update or Other Action Per J.Wiegers, change file number from L30.21 to 2100.26.030 Wendy Uzzell
11/14/2003 Document, Report, or Work plan Review - other Groundwater monitoring and remedial system report submitted. Vapor concentrations in system exhaust remain low. Pump and treat system has not been active since June due to groundwater levels. Contaminants detected above cleanup levels in MW-1 (benzene at 2,300 ppb), B5MW (benzene at 7,700 ppb), and the off-site well MW-9 (benzene at 1,600 ppb). Janice Wiegers
11/14/2003 Update or Other Action Drinking water well was installed at 900 East Dowling Road. Williams has collected five samples from the well which have not contained any contaminants. Quarterly sampling will continue until the site is connected to municipal water. Janice Wiegers
12/12/2003 Update or Other Action Annual Williams meeting. S&W will evaluate potential indoor air effects. Janice Wiegers
3/19/2004 Document, Report, or Work plan Review - other Workplan for lead scavenger sampling approved. EDB will be analyzed with EPA method 8260. Further evaluation with a method with a lower detection limit may be conducted in future sampling events. Janice Wiegers
9/7/2004 Leaking Underground Storage Tank Corrective Action Underway On 07 July 2004, Bush met with Holiday representative Bruce Anthony; Williams Express representative Terrie Blackburn; and Shannon & Wilson representatives Matt Hemry, Ben Heaver, and Tim Terry. The topic of discussions was plans for future activities at all former Williams Express Stations. Lynne Bush
9/8/2004 Leaking Underground Storage Tank Corrective Action Underway Holiday will be assuming responsibility for investigative and remediation activities at all former Williams Express Stores, but legal responsibility is divided by store. Holiday has renumbered their stores as: 5001=601; 5002=602; 5005=605; 5005=605; 5006=606; 5007=607; 5008=608; 5010=610; 5014=614; 5016=616; 5018=618; 5024=624; 5025=625; 5030=630; 5031=631; 5050=650. While Holiday will oversee the work at the former Williams’ stations, these sites remain the responsibility of Williams. The numbers of these sites remain the same: 5003; 5004; 5009; 5012; 5015; 5017; 5021; and 5034. Lynne Bush
3/15/2006 Update or Other Action July 2005 Work plan approval: 1. Continue semi-annual monitoring in accordance with the currently approved work plan; 2. Suspend sample collection from MW-20, MW-21, and B6MW; 3. Decommission MW-16, MW-21, MW-22, and MW-24; 4. Unless product is observed, product monitoring is suspended indefinitely; 5. Reduce collection of samples to only untreated groundwater at the Park & Sell property, performed on an annual basis; and 6. Provide a summary of results in the annual report for this site. Lynne Bush
5/9/2006 Update or Other Action Project management transferred from Bush to O'Connell. Aggie Blandford
5/15/2006 Document, Report, or Work plan Review - other Received April to December 2005 monitoring report. Onsite wells have bulk of contamination, however plume extends to the SW. No DW wells have reportedly been impacted. Benzene and/or GRO and/or DRO and/or RRO above Table C in MW-1, MW-9, MW-10, B5MW, and B13MW in 2005. P&T system is not operating, VES operating on pulse. Report states that MW-16, MW-21, MW-22, and MW-24 were decommissioned in October 2005 and this effort was reported under separate cover. Bill O'Connell
7/10/2006 Update or Other Action ADEC was contacted by a resident of Fischer St who said there was a collapsed monitoring well in her driveway. ADEC contacted Shannon and Wilson who responded and found that the well, MW-14, had apparently been drilled through a concrete vault covered by a manhole. Shannon and Wilson contacted MOA and the plan is to decommission the MW and replace the concrete vault. Bill O'Connell
10/9/2006 Update or Other Action Memo received from S&W states that storm drain at MW-14 was repaired and the monitoring well was shortened and remained intact. According to 2003 site summary report, ADEC approved dropping MW-14 from the sampling program in 1992. Keather McLoone
3/16/2007 Exposure Tracking Model Ranking Bill O'Connell
6/25/2007 Document, Report, or Work plan Review - other Received 2006 monitoring report. QA/QC conducted. Samples collected from 9 MWs in April and 7 MWs in September. Highest contaminant concentrations are in onsite wells MW-1 and B5MW, but contaminant concentrations above Table C can be found in MW9, approximately 400 feet SW of the source area. Complex hydrogeology limits the effectiveness of the remediation system, however the VES continues to recover significant quantities of fuel vapors. Bill O'Connell
9/3/2008 Update or Other Action Received 2007 Remediation System and Groundwater Monitoring report electronically. VES operated for 2 months and was then found to be non-functional... will remain turned off and potential remedial alternatives will be evaluated. Report suggests that incorrect wells have been sampled in the past, and wells will be labeled to prevent this from happening again... report recommends for sampling to be reduced to an annual basis in the spring. Benzene, GRO, DRO, and RRO exceeding Table C remain in various wells. The drinking water well at Park-N-Sell will be sampled once during 2008. Keather McLoone
5/20/2009 Document, Report, or Work plan Review - other Reviewed Site Characterization Work Plan. The objective is to develop a better understanding of the complex geology and hydrocarbon distribution at the site so that further remedial efforts will be more effective. Up to 15 direct push soil probes will be advanced, and up to two additional monitoring wells will be installed at a later date, based on information from the soil borings. Requested that future reports describe how groundwater gradient is derived. Keather McLoone
6/10/2009 Document, Report, or Work plan Review - other Reviewed April/June and September Groundwater Monitoring Reports. Nine wells were sampled during each of these 2 events. A post-treatment drinking water sample was also collected in December from the adjacent Park-N-Sell property to the east. (NOTE: The March 2006 workplan stipulated sampling of **untreated** groundwater at this location). Additional site characterization to guide future remedial activities was planned for May and recently put on hold pending a decision by Sears (adjacent property to north) regarding site access. MW-14 will be decommissioned during upcoming well installation activities (effort earlier this year to decommission was unsuccessful due to ice in storm drain). Laboratory review checklist not provided for December's drinking water sample. ADEC reviewed data quality issues and provided feedback to consultant. Keather McLoone
7/6/2009 Update or Other Action Letter sent to further document conditional workplan approval. Keather McLoone
10/14/2009 Site Visit Site visit with Holiday and S&W representatives to observe new well locations. Holiday would like to remove some unused, aboveground portions of the remediation system that are quite large and unattractive site features. Keather McLoone
4/5/2010 Document, Report, or Work plan Review - other Reviewed May and September Groundwater Monitoring report received 3/4/2010. Nine wells were sampled in May and 7 in September (2 wells on Sears property could not be sampled due to access issues). Report states that remedial alternatives are "pending selection." Keather McLoone
4/7/2010 Document, Report, or Work plan Review - other Reviewed Work Report received 3/30/10. The scope of work was adjusted due to site access issues with Sears and limited effectiveness of the push probe into subsurface gravel/cobble. Two incomplete push probes and 9 soil borings (both onsite and offsite) using a hollow stem auger were advanced with 4 completed as monitoring wells. Aerial photographs from previous years were compared to more recent ones in an attempt to understand potential historical source areas. MW-14 was decommissioned on October 14, 2009. A survey was conducted, including the 4 new wells, 6 existing wells, and 6 borings. Between 1 and 3 soil samples per boring were submitted to the laboratory. 13 of the 16 samples contained concentrations greater than Migration to GW levels. All soil samples were collected from: within 4 feet above the observed water level; within the water bearing zone; or at the top of the glacial till layer assumed to be an aquitard. Area of impacted soil extends offsite and appears to exist primarily in the smear zone and/or below the water table. Groundwater samples exceeded Table C levels in each of the new wells except MW-26. This report states that “no additional remedial action contemplated at this time” and that a replacement for MW19 will be installed. DEC will send a comment letter in response to this report with concerns about several items including the proposed level of effort at this site since additional characterization, if not remediation, is warranted. This letter was dated 4/16/2010. Keather McLoone
4/8/2010 Site Visit Site visit to confirm current presence of aboveground structures. Keather McLoone
4/20/2010 Document, Report, or Work plan Review - other Receipt of document prepared by DOWL HKM on behalf of ADOT entitled West Dowling Road Phase I - October 2009 Phase II Environmental Site Assessment and Soil and Groundwater Sampling Event. Includes a figure which gives a rough idea of the road improvement area and what wells might be affected. Revised engineering plans may be developed and actual work may alter the actual area to be affected. Two borings were advanced near the intersection of Old Seward and Dowling. These were advanced to 4 ft bgs as that is the depth of anticipated excavation during upcoming road construction activities which are currently planned to take place during 2011. One sample from each boring was collected at 4 ft bgs and analyzed for GRO/DRO/RRO and BTEX with all results nondetect at limits well below cleanup levels. Keather McLoone
5/6/2010 Update or Other Action DEC requested for the feasibility of several remedial alternatives be considered for this site, including restarting the current VES. This evaluation should be put into writing for our records. This was requested as follow up to a recent telephone conversation and meeting with Shannon & Wilson. Keather McLoone
5/7/2010 Update or Other Action Emailed an example of a soil management plan to DOWL, ADOT's consultant for upcoming road construction related activities, and requested that something similar be submitted prior to construction. Keather McLoone
6/23/2010 Document, Report, or Work plan Review - other Review of Limited Water Well Survey, Conceptual Site Model, and Remediation System Evaluation received on 6/23/2010. Keather McLoone
6/29/2010 Update or Other Action DEC contacted Phil Haws, owner of the Park-N-Sell across the Old Seward Hwy and explained that last year's investigation found product on groundwater under the roadway. The owner asserted that he had no information about the drinking water well on their property and that it was not used for drinking water, nor was city water. Rather, "bottled" water was being supplied for drinking, and he had no concerns about the potential impacts to the health of his staff. A letter was sent to Mr. Haws on July 6, 2010 to confirm the conversation and to reiterate DEC's concerns about potential impacts from contaminated groundwater. It is possible that heavy use of water at this well could create a hydrologic gradient, "pulling" contaminated water toward Park-N-Sell. Keather McLoone
6/30/2010 Update or Other Action CS staff met via teleconference with Williams Companies, Holiday Companies, and Shannon & Wilson to discuss this site. The teleconference was requested by Holiday and Williams to discuss their request to continue to leave the onsite Vapor Extraction System (VES) off, to remove the current remediation shed, and to continue monitoring rather than conduct any further remedial action at this site. CS staff pointed out that there has been no approval to turn the VES off. CS staff requested that information regarding facility upgrades planned by Tesoro, the current operator of the onsite gas station, be provided as well as plans for additional site characterization to be performed to further delineate the plume of contamination before CS staff approves removal of the remediation shed or a discontinuation of monitoring at this site. Keather McLoone
9/22/2010 Document, Report, or Work plan Review - other Receipt via email at DEC request for document of proposed scope entitled Additional Site Characterization Activities. Followup email on following day regarding figure. Document outlines proposed activities which include a workplan for additional soil, groundwater and soil gas characterization. Up to six soil borings will be advanced and completed as monitoring wells, up to five of which will be installed to delineate contamination to the north and east of the subject property. At a minimum, one will be installed to the north and one to the southeast of the intersection beside the Park-and-Sell. Former MW19 will also be replaced. Keather McLoone
10/11/2010 Update or Other Action CS staff sent letter commenting on the proposed outline of Additional Site Characterization Activities. Comment to date focused on evaluation of the potential for vapor intrusion on the adjacent Sears property. It was also stated that further comment may be forthcoming in response to anticipated workplan. Keather McLoone
10/19/2010 Update or Other Action Received a critique of Shannon and Wilson's work plan from URS (on behalf of Sears), entitled, "Proposed Modifications to Work Plan Williams Express Site (WES) No. 5021" in which URS provides alternative interpretations of historical data and provides alternative recommendations for ways to characterize the contaminant plume. Keather McLoone
12/7/2010 Document, Report, or Work plan Review - other Date of Additional Site Characterization Work Plan. Activities generally match proposed scope document with the inclusion of additional vapor intrusion activities as recommended in DEC letter dated 10/11/10. Keather McLoone
12/22/2010 Update or Other Action Request via email of 2010 data in order to complete review of recently received workplan. Keather McLoone
5/10/2011 Site Visit Site visit today to confirm no excavation activities have begun and to confirm the presence and addresses of two residences with private drinking water wells. Keather McLoone
5/18/2011 Meeting or Teleconference Held CS staff met with Sears & Roebuck Co representatives, Williams Companies representatives, and Breck Tostvein to discuss the Former Williams Express Station Store 5021 located at Dowling Road and Old Seward Highway in Anchorage, Alaska. Items discussed included status of site access agreement, site status, current workplan, and path forward for the site. Sears is an adjacent property owner and requested the meeting to discuss concerns about the timeline and outcomes intended for this site. Keather McLoone
6/6/2011 Document, Report, or Work plan Review - other Received April/May and September 2010 Groundwater Monitoring report. In addition to the two groundwater sampling events, product recovery was also conducted at one well, MW27, during May. About 1.5 inches of product was observed and an attempt was made to recover using a bailer. No product observations were reported for the fall event but the report also does not specifically state that product was not observed. B4P and B8MW were not sampled due to access issues. MW19 was not located again during these efforts. Report comment letter noted that the private well located on the adjacent Park-N-Sell property was not sampled again last year and requested that the well be sampled twice a year to fill data gaps created by repeatedly overlooking this well. Keather McLoone
7/15/2011 Site Visit Several site visits during this week to observe additional site characterization activities on adjacent properties, Sears warehouse in particular. Activities include installation of groundwater and soil gas wells and soil sample collection. Keather McLoone
8/3/2011 Site Visit Site visit to observe soil gas sampling at the adjacent Sears property. Consultant following workplan and proper soil gas sampling procedures. Keather McLoone
8/31/2011 Site Visit Site visit to observe location of 2 new monitoring wells located downgradient and to observe whether there has been any tank work done. Saw no sign that the asphalt and concrete areas around the tanks had been disturbed. Keather McLoone
12/1/2011 Site Visit Site visit to meet with DOT and answer questions related to Dowling Expansion project. Keather McLoone
12/7/2011 Update or Other Action Received results from the 23 September 2011 drinking water well sampling at Worthington's Park-N-Sell. Water was sampled for BTEX, GRO, DRO, and RRO. All results, except RRO, at 1.38 mg/L, were below Table C. Chromatogram review showed an elevated baseline for RRO, which may have been associated with carryover from a previous sample. Worthington was notified in letter dated December 9, 2011 and access to resample was requested and granted verbally. Worthington called around December 21st to indicate that they were working on hooking up to city water. Well decommissioning was discussed. Keather McLoone
12/9/2011 Document, Report, or Work plan Review - other Date of receipt of Additional Site Characterization report. Report discusses soil boring and soil sampling; monitoring well installation, development, and sampling; soil gas point installation and sampling (including leak detection), and groundwater survey. Seven borings were advanced and two samples were collected from each. Soil exceeding most conservative criteria for GRO, BTEX, and 1,2,4-trimethylbenzene was collected from the smear zone at MW-30. The soil in the smear zone at MW-31 may also be impacted but a sample was not collected here because of problems with recovery from the split spoon. Groundwater was collected from the seven newly installed wells (3 on Sears property, one @ the NE and one @ the SE corner of the intersection of Dowling and Old Seward, and two in the neighborhood located downgradient), and from two previously installed wells (located on Sears property). Product was observed in one newly installed well on the Sears' property. Contaminated groundwater was observed in two other wells sampled, both on the Sears' property. Soil gas results indicated that vapor intrusion is not likely to be an ongoing issue and another round of sampling will not be requested at this time. Keather McLoone
12/29/2011 Update or Other Action Receipt of results of resample of Worthington Park-N-Sell drinking water well. Sample was collected on December 15, 2011 and analyzed for BTEX, GRO, DRO, RRO, DRO silica gel, and RRO silica gel. All results below Table C. Keather McLoone
2/2/2012 Document, Report, or Work plan Review - other Date of receipt of Product Recovery Assessment planning document which discusses activities that will include: measuring free-phase product, recovering product, and measuring product recharge at MW-30. Keather McLoone
2/2/2012 Document, Report, or Work plan Review - other Date of receipt of Groundwater Sampling Schedule. This planning document discusses the 22 on-site and off-site groundwater monitoring wells and the drinking water well located at the adjacent Park-N-Sell. Keather McLoone
3/14/2012 Exposure Tracking Model Ranking A new updated ranking with ETM has been completed for source area 77717 USTs. Keather McLoone
3/16/2012 Meeting or Teleconference Held Met with Sears consultant (URS) and Williams consultant (Shannon & Wilson). Sears and Williams representatives also teleconferenced into the meeting. Goal was to make progress toward a shared understanding of the technical issues associated with the site. The URS letter dated 1/23/2011 was discussed on an item by item basis. Keather McLoone
4/10/2012 Update or Other Action Receipt of letter entitled Response to Alaska Department of Environmental Conservation March 7, 2012 letter. This letter responds item by item to the most recently sent comment letter. Keather McLoone
4/10/2012 Document, Report, or Work plan Review - other Receipt of the planning documents Revised Product Recovery Assessment and Supplemental Vapor Instrusion Pathway Assessment. Keather McLoone
4/10/2012 Document, Report, or Work plan Review - other Date of receipt of Revised Groundwater Sampling Schedule. S&W is going to try to get out to sample early next week before road construction activities might interfere with or even destroy existing wells. Gave a conditional approval via email for the sampling effort to be conducted next week. Keather McLoone
4/26/2012 Document, Report, or Work plan Review - other Date of receipt of May and September 2011 Groundwater Monitoring report. Ten wells were sampled in May and 18 wells were sampled in September. Two wells were not sampled in September because of 0.02-0.03 ft of product. Some of these wells were decommissioned in April 2012 due to being otherwised destroyed or compromised due to the road construction project currently underway. Two wells that have not been decommissioned had very high turbidity (>1000 NTU) in September 2011. Keather McLoone
5/8/2012 Document, Report, or Work plan Review - other Date of receipt of Historical Groundwater Monitoring Results Summary Tables and Contaminant Distribution Map. Keather McLoone
6/2/2012 Document, Report, or Work plan Review - other One recovery well and six monitoring wells were decommissioned on 3 & 4 May to include: RW-2, B4P, B8MW, MW-20, MW-27, MW-28, & MW-29. It is believed that all wells would have been impacted by the Dowling Road expansion project. Richard Bernhardt
6/27/2012 Site Visit Conducted a site visit to determine how the Dowling Road construction activity has affected the Monitoring Well array and to get a feel for the location of two newly proposed wells (NW of Sears) in relation to Campbell Creek and the free product recently reported at the SE corner of Sears. Also saw the remediation system and wells located near USA Gas (formerly called WES 5021). Richard Bernhardt
6/28/2012 Site Characterization Workplan Approved Approved work plan to install and sample two new MWs north of Sears Warehouse and sample MWs 30-32 (east and southeast of warehouse). Asked Williams/Holiday to consider two topics: 1) reinstall MW-12 to define the plume east of the source area and 2) install one or more wells south of Sears Warehouse when practical, given Dowling Road construction activity. Richard Bernhardt
9/6/2012 Site Visit Briefly stopped by to determine status of Dowling Road expansion project and gauge the feasibility of reinstalling monitoring wells southeast of Sears' property. Dowling Road is still under construction and approximately 2-3" below grade at the Sears' parking lot, so reinstallation of wells is not yet feasible. Richard Bernhardt
11/22/2012 Update or Other Action Spoke with ADOT personnel to determine the status of road construction at Old Seward and Dowling (between former WES 5021 and Sears Warehouse). ADOT is finished with road construction activities for the winter, and they have relocated the entryway into Sears property. The new entrance is at least 30-40 yards west of its former location, so customer access to the warehouse should be much less impacted by characterization and monitoring activities in the future. ADOT will complete Dowling Road reconstruction activities next spring when they will add a "surface lift" to the existing pavement. Temperatures must exceed 50 degrees Fahrenheit before this is possible, but it should only take about two days to complete, once started. The goal will be to raise the road surface 2-3 inches (to the grade of surrounding parking lots) with a fresh layer of asphalt. ADOT is projecting a completion date in late May or early June. Richard Bernhardt
12/5/2012 Meeting or Teleconference Held ***Project manager participated in a meeting with Williams representatives (Rebecca Brown & Mark Gebbia), Holiday (Bruce Anthony) and their consultants from S&W (Matt Hemry and Dan McMahon). Alternative remediation strategies to address contamination remaining off-property near WES 5021, as well as strategies to progress toward site closure were the focus of this annual meeting. Major issues of concern include: historic remediation efforts to addres the most hevily contaminated areas off-property and impacts to surrounding property owners. *** the plume does not appear to be migrating but retains free product and significantly elevated hydrocarbon concentrations beyond the radius of influence of the existing remediation system, which hasn't operated since 2008. Shannon & Wilson's "Soil Gas and Groundwater Evacuation" pilot study was discussed as a preferred remediation option for reducing plume dynamics to a state where enhanced natural attenuation or MNA may become viable options. A work plan outlining Williams' preferred remediation strategy is due by March 1, 2013. *** the functional status of the down gradient well at 645 Pearl Drive (the Cross Well) should be investigated, reported, and sampled annually, if at all possible. It should also be decommissioned, if possible. *** One or more monitoring wells should be reinstalled south of Sears (near B4P). *** Untreated water from the well at Park-N-Sell should be sampled annually. Richard Bernhardt
4/25/2013 Document, Report, or Work plan Review - other Reviewed Product Recovery Assessment for WES 5021. This assessment was conducted after approximately 0.51 feet of product was measured in monitoring well MW-30 in July 2011 following its installation. Attempts were made to measure free product in September and December 2012 and in January 2013. At no time was measureable product present in the well, therefore product recovery could not be evaluated. If free product is encountered in future monitoring events, the product recovery test will be conducted per the April 2012 work plan. Bill O'Connell
5/9/2013 Document, Report, or Work plan Review - other Reviewed Monitoring Well Installation and Sampling Report for WES 5021. Two soil borings were advanced and completed as monitoring wells MW-37 and MW-38 in an effort to evaluate the extent of contamination north of the Sears warehouse. Two soil samples were collected from each borehole from the interval with highest PID reading. DRO, GRO, and BTEX were not detected. RRO was detected up to 13.1 mg/kg. Groundwater samples were collected from various wells on the Sears property in September 2012 and again in January 2013. Samples were collected from MW-31, -32, -37, and 38 in September 2012 and from MW-30, -31, and -32 in January 2013. Free product had been encountered in MW-30 on previous occasions, but was not encountered during either sampling event. During the September event, groundwater samples did not contain detectable concentrations of DRO, GRO, RRO, or BTEX. The water level in MW-37 was above the screened interval during this sampling event. During the January event samples from MW-30 contained GRO up to 33.9 mg/l, DRO up to 1.51 mg/l, and benzene up to 0.266 mg/l. Benzene was also detected at MW-31 at 0.0064 mg/l. No other samples contained contaminants above cleanup levels. Bill O'Connell
5/14/2013 Document, Report, or Work plan Review - other Reviewed 2012/2013 groundwater monitoring report for WES 5021. Monitoring events were conducted in April and September 2012 and in January 2013. Groundwater samples were collected from 14 monitoring wells in April 2012. Samples were analyzed for the standard hydrocarbon ranges and constituents, and also for PCBs, VOCs, and metals. Approximately 0.05 foot of free product was noted in MW-27 located in the roadway on Old Seward Highway. Source area well MW-1 contained GRO at 51.2 mg/l and benzene up to 0.340 mg/l. DRO, toluene, ethylbenzene, xylenes, 1,2,4-trimethylbenzene, n-propylbenzene, and arsenic were also detected above cleanup levels in this well. Downgradient well MW-9 located southwest of the source area on Pearl Drive contained GRO at 10.1 mg/l and benzene at 1.42 mg/l. RRO, ethylbenzene, arsenic, and chromium were also detected above cleanup levels. Source area well B5MW contained benzene at 23.1 mg/l. Toluene, xylenes, and ethylbenzene were also detected above cleanup levels in this well. Samples collected from sentinel wells did not contain contaminants above cleanup levels. PCBs were not detected in any samples. Lead was detected above the cleanup level in 6 samples but did not correspond with exceedances of GRO. Between April and September, six monitoring wells were decommissioned and two were installed as noted in previous database actions. Detections of VOCs are consistent with those found in refined fuels, except at well MW-20 which contained the solvents 1,1,1-trichlorothane and 1,1-dichloroethane. Groundwater samples were collected from 13 wells in September 2012. Product was not observed in any of the wells. Source area well MW-1 contained GRO at 62.1 mg/l and benzene at 0.843 mg/l. toluene, ethylbenzene, and xylenes were also detected above cleanup levels. Downgradient well MW-9 contained GRO at 17.2 mg/l and benzene at 1.99 mg/l. Ethylbenzene was also detected above the cleanup level. Sentinel wells did not contain contaminants above cleanup levels. A drinking water sample collected from the Park and Sell well did not contain det4ectable concentrations of contaminants. The report indicates the plume is steady state with sample results generally consistent with previous results. See action dated 5/9/2013 for January 2013 results. Bill O'Connell
5/22/2013 Document, Report, or Work plan Review - other Reviewed Supplemental Vapor Intrusion Pathway Assessment for WES 5021. An attempt was made to sample soil-gas point #3, which was damaged or clogged during installation in 2011. The sample point was still unusable in 2013 and no sample was collected. Bill O'Connell
5/30/2013 Site Visit Cross well located in front of the house at 645 Pearl Drive. Bill O'Connell
7/25/2013 Document, Report, or Work plan Review - other Remediation system to be decommissioned in accordance with ADEC guidance. Bill O'Connell
7/30/2013 Document, Report, or Work plan Review - other Reviewed Site Characterization Work Plan for WES #5021. The objective of this Site Characterization effort is to determine which downgradient properties to the Southwest have contaminants in groundwater or soil at concentrations above ADEC cleanup levels, whether additional monitoring wells are needed to define the contaminant plume boundaries, and whether any drinking water wells are present within the plume. Boreholes will be advanced in six locations to just beyond the groundwater interface and soil samples will be collected from the interface. Temporary wells will be installed into each borehole and screening level groundwater samples collected to evaluate for the presence or absence of contamination. After sample collection, the wells will be removed and the boreholes filled with bentonite. Bill O'Connell
10/2/2013 Document, Report, or Work plan Review - other Reviewed Remediation System and Recovery Well Decommissioning report for WES 5021. All above ground equipment was removed from the site. Recovery well RW-5a was decommissioned in accordance with ADEC guidance, well RW-3 could not be located and is presumed to have been destroyed. Bill O'Connell
12/13/2013 Document, Report, or Work plan Review - other Reviewed Tesoro Autostop #2, (AKA former Williams Express #5021) October 2013 UST Site Assessment Report. Two, 12,000-gallon USTs, piping, and four dispenser islands were removed during this project. The USTs were installed in 1995, however up to 17 USTs have been present at this property at various times since the 1950s. Soil that was excavated as part of the UST removal was stockpiled based on the suspected presence of hydrocarbon contamination. Stockpile samples indicated contaminants were present is Stockpiles #1 and #2 and these stockpiles were hauled to ASR for treatment. In addition to obviously contaminated soil that was directly hauled, a total of 2,006 tons of contaminated soil was treated at ASR. Stockpiles that did not contain contaminants above cleanup levels were used as backfill. Following removal of the USTs, 5 confirmation samples were collected from the bottom of the excavation 14-17 feet below ground surface (bgs) and 4 samples were collected from the sidewalls. Of the 5 bottom samples, DRO was detected above the cleanup levels in sample Tank Bottom 2 at 8,710 mg/kg. No other contaminants were detected above cleanup levels. Of the 4 sidewall samples, DRO was detected above the cleanup levels in 1 sample, East Sidewall. Sample East Sidewall was collected 14-16 feet bgs and contained DRO at 380 mg/kg, GRO at 4,140 mg/kg and benzene at 0.0936 mg/kg. Toluene, ethylbenzene, and xylenes were also detected above cleanup levels in this sample. Groundwater was not encountered in the excavation and the USTs appeared in good condition with no evidence of holes or leaks. The dispenser islands and fuel piping was removed in accordance with ADEC guidance; contaminants were not detected in confirmation soil samples collected beneath the piping or dispensers. New USTs were placed back into the open excavation, which was enlarged to accommodate the larger USTs. Bill O'Connell
12/23/2013 Document, Report, or Work plan Review - other Reviewed Additional Site Characterization Report for former Williams Express #5021. The objective of the investigation was to identify specific downgradient properties that have been impacted by releases from the site and evaluate current contaminant concentrations in soil and groundwater. Activities conducted during this investigation included advancing 6 push probe soil borings to install temporary monitoring wells and collecting soil samples from the boreholes. The temporary wells nearest the source area, PB-1, PB-3, and PB-6 encountered areas of perched water from 4.5 to 12.5 feet bgs so the samples from these wells my not be representative of the contaminated aquifer located approximately 21 feet bgs in other permanent monitoring wells in the area. Groundwater was not encountered in PB-2. Soil samples collected from the boreholes did not contain contaminants above cleanup levels however soil samples collected within the plume were not collected from the smear zone at a depth considered representative of the groundwater interface. Groundwater samples from PB-1 and PB-3 contained RRO at 1.53 and 1.92 mg/L which is slightly above the cleanup level, however these samples were collected from intervals of perched water and are not likely representative of the deeper contaminated aquifer. Groundwater samples from PB4 and PB5 along Austin Ave were collected from between 21 and 26 feet bgs and did not contain contaminants above cleanup level suggesting that the western extent of the plume has been delineated. Bill O'Connell
3/17/2014 Document, Report, or Work plan Review - other Reviewed September 2013 Groundwater Monitoring Report for WES 5021. Samples were collected from 13 monitoring wells and product levels were measured in three wells that had previously contained product. Monitoring well were purged prior to sampling during this event as compared to previous recent monitoring events in which samples were collected without purging. A drinking water sample was also collected from the Park and Sell across the street. Contaminants were detected above groundwater cleanup levels in 4 of the samples, with benzene detected up to 0.567 mg/l in MW-9, GRO detected up to 53.2 mg/l in MW-1, DRO detected up to 4.62 mg/l in MW-1 and RRO detected up to 4.31 mg/l in B13MW. MW-1 is within the source area and was removed during site activities in 2013. It is anticipated that this well will be replaced in 2014. Sampling results indicate a stable plume with contaminant concentrations that have generally decreased over the last 10 years. Measurable product was not encountered in any of the wells during the September 20-13 event. Contaminants were not detected in the sample from the Park and Sell well. Bill O'Connell
5/23/2014 Document, Report, or Work plan Review - other Reviewed Site Characterization Work Plan for WES 5021. The objective of the work is to further define the limits of contamination in soil and groundwater downgradient of the site, particularly in the vicinity of Pearl Drive. Proposed activities include the advancement of three soil borings, collection of soil samples, completion of the borings into monitoring wells and collection of groundwater samples. Borings will be advanced beyond intervals of perched groundwater that have been observed around 10 feet bgs to the deeper aquifer located 25 to 35 feet bgs. Soil samples will be collected for field screening at 2.5 foot intervals and two samples per borehole will be submitted for laboratory analyses; one from the soil/water interface and the sample with the highest PID reading. An updated drinking water well survey will also be conducted. Bill O'Connell
12/2/2014 Document, Report, or Work plan Review - other Reviewed Site Characterization report for WES #5021. These activities were the second phase of an effort to further delineate the limits of downgradient impacts to soil and groundwater. Three soil borings were installed and completed as monitoring wells MW-39, MW-40, and MW-41. Two soil samples were collected from each borehole, one from the soil/groundwater interface approximately 24-24.5 feet below ground surface, and one from the location of the highest field screening value. Groundwater samples were collected following installation and development of the wells. Contaminants were not detected in soil or groundwater samples. The report also contains an updated, detailed well search which indicates there are no drinking water wells in use within the plume area. Bill O'Connell
4/6/2015 Document, Report, or Work plan Review - other Reviewed email work plan for monitoring well replacement at WES #5021. During construction activities in 2013 and 2014, monitoring wells MW-1, MW-26, and B13MW were decommissioned. Based on current site information, it was determined that only MW-1 should be replaced. One soil boring will be advanced and completed as monitoring well MW-1R. Soil samples will be collected for field screening and the two samples with the highest PID results will be submitted for laboratory analysis. The well will be developed and sampled following installation Bill O'Connell
4/29/2015 Document, Report, or Work plan Review - other Reviewed August 2014 Groundwater Monitoring Report for the former Williams Express #5021. Groundwater samples were collected from 14 monitoring wells and one drinking water well in August 2014. NAPL was not observed in any of the wells including MW-30, which most recently contained measurable NAPL in 2011. GRO was detected above the cleanup level in one well, MW-31 at 4.81 mg/l, RRO was detected above the cleanup level in one well, MW-9 at 3.57 mg/l and benzene was detected above the cleanup level on both of these wells up to 0.288 mg/l in MW-9. The sample from the drinking water well at the former Park and Sell did not contain detectable concentrations of contaminants Bill O'Connell
7/10/2015 Document, Report, or Work plan Review - other Reviewed work plan for additional delineation at WES #5021. Three monitoring wells will be installed and sampled along Pearl Drive and the easement between Pearl Drive and Dowling Road in an effort to more closely delineate the extent of groundwater contamination. Bill O'Connell
7/21/2015 Document, Report, or Work plan Review - other Monitoring wells MW-8a, MW-10, MW-25, MW-33, MW-34, MW-37, and MW-38 were decommissioned in accordance with ADEC guidance in June 2015. Bill O'Connell
10/7/2015 Document, Report, or Work plan Review - other Reviewed Drinking Water Well Decommissioning report for 645 Pearl Drive. The former drinking water well had been connected to the former pump-and-treat groundwater system at the site and had not been in use for a number of years. The well was located within a manhole on the south side of the residence and was decommissioned by filling the casing with bentonite, welding a steel cap on top of the casing, and filling the lower part of the manhole with additional bentonite. The remainder of the manhole was filled with gravel to the ground surface. The manhole and cover remain in place as the property owner did not wish to have these excavated. Bill O'Connell
3/22/2016 Document, Report, or Work plan Review - other Reviewed Additional Site Characterization and 2015 Annual Groundwater Monitoring Report for WES 5021. Three new soil borings were advanced and completed as monitoring wells in an effort to further delineate the plume boundary. Soil samples collected from the boreholes contained benzene above the migration to groundwater cleanup level in borehole 42 at 0.243 mg/kg at 30-32 ft bgs and in borehole 43 at 0.0774 mg/kg at 27.5 to 29.5 ft bgs. Groundwater monitoring included the collection of samples from 12 existing wells and the three new ones. Contaminants above Table C groundwater cleanup levels were detected in wells MW-1R, MW-9, MW-31, MW-40 and the new well MW-42 located in the easement just southwest from the source property. The current plume map indicates groundwater contamination above Table C cleanup levels extends from the Sears Warehouse property just north of the former WES 5021 south to the north side of Fisher Ave encompassing approximately 12 residential properties located on Pearl Drive and Fisher Ave. Bill O'Connell
5/25/2017 Document, Report, or Work plan Review - other Reviewed September 2016 groundwater monitoring report for WES 5021. Groundwater samples were collected from 5 wells at the site and two additional wells were screened for the presence of free product. The results indicate that contaminant continue to exceed groundwater cleanup levels at the source property, on the Sears Warehouse property to the north, and in the vicinity of Pearl Dr. to the southwest, the predominant groundwater flow direction. GRO was detected up to 31.2 mg/l, DRO was detected at 11.7 mg/l, and benzene was detected up to 1.92 mg/l. The highest concentrations are found onsite and immediately to the southwest. Bill O'Connell
11/16/2017 Document, Report, or Work plan Review - other Reviewed and approved Groundwater Monitoring Well Installation and Sampling Plan for WES 5021. Four monitoring wells (MW-45 to MW-48) will be installed; two sentinel wells along Fisher Ave, one well to replace MW-41 and one well to replace MW-9. One soil sample will be collected from the approximate groundwater interface in each borehole and analyzed for DRO, GRO, and BTEX and the sample with the highest PID reading will also be analyzed for VOCs and PAHs. The four new wells will be installed and developed then added to the biennial sampling schedule along with wells MW-1r, MW-31, MW-32, MW-39, MW-40 and MW-42. The first biennial event will occur in August 2018. Bill O'Connell
6/12/2019 Update or Other Action DEC request to Lee Andrews of Williams regarding the status of the Groundwater Monitoring Well Installation and 2018 groundwater monitoring reports for the Former Williams Express Store #5021 site. The monitoring wells were to be installed in May 2018 and the monitoring wells were to be sampled in August 2018. Robert Weimer
2/5/2020 Update or Other Action DEC receives notification from Williams consultant Shannon and Wilson that they have not been contracted to do any further work on the site, which includes the work in the work plan that DEC approved on 11/16/2017. Robert Weimer
6/29/2020 Document, Report, or Work plan Review - other DEC approved updates to the 2017 workplan for replacement of the monitoring wells MW-41, MW-9, MW-36, MW-35, and MW-39. Janice Wiegers
4/21/2021 Update or Other Action Contacted Williams about the status of the report for work completed last summer. Janice Wiegers
5/5/2021 Update or Other Action DEC sent letter to Williams requesting reporting for last summer's field work by May 30, 2021. Janice Wiegers
5/20/2021 Document, Report, or Work plan Review - other Monitoring Well Installation and 2020 Groundwater Monitoring Report, dated September 2020, submitted by S&W. Five new wells (MW-45 through MW-49) were installed to replace MW-41, MW-9, MW-36, MW-35, and MW-39, respectively. Soil samples were collected during well installation; benzene was above cleanup levels at 25 ft bgs at the location of MW-46. Groundwater monitoring wells were sampled on July 28, 2020. Benzene, ethylbenzene, xylenes, GRO, or DRO continue to exceed cleanup levels in MW1R, MW-42, and MW46. B5MW did not contain product. Monitorng wells MW-30 to MW-32, and MW-40 were not sampled due to lack of access agreements. Williams is working toward new agreements. Janice Wiegers
8/12/2022 Update or Other Action Contacted by S&W regarding a work plan that will be drafted to begin monitoring again. VOCs and PAHs will be added for testing. Janice Wiegers
3/7/2023 Long Term Monitoring Workplan or Report Review Groundwater monitoring plan submitted by S&W. The plan is dated 11/17/2022. Samples will be collected from MW-1R, B5MW, MW-30, MW-31, MW-32, MW-40, MW-42, and MW-45 through MW-49. DEC approved the plan on 3/8/2023. Janice Wiegers
3/13/2023 Offsite Soil or Groundwater Disposal Approved Transport approval signed for disposal of purge water during upcoming groundwater monitoring event. Water will go to the US Ecology Viking Facility for treatment and disposal. Janice Wiegers
3/28/2023 Document, Report, or Work plan Review - other Reviewed decommissioning report for a monitoring well that was installed through the floor of the former Sears Warehouse on the property to the north. Janice Wiegers
8/23/2023 Document, Report, or Work plan Review - other Groundwater montioring report submitted. Samples were collected in April and May from the wells included i the plan, except for MW-40 which could not be accessed. Contaminants exceeding groundwater cleanup levels were observed in MW-1R, B5MW, MW-30 and MW-46. Contaminants included GRO, DRO, RRO, BTEX, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, and naphthalene. Other PAHs were observed below cleanup levels in various wells. 1,1,1-trichloroethane was observed in MW-42 and cis-1,2-dichloroethene was observed in MW-46 below cleanup levels. Report was approved 9/29/2023. Janice Wiegers

Contaminant Information

Name Level Description Media Comments

Control Type

Type Details
COBC 1991 includes 14 Anchorage Mapco stations

Requirements

Description Details

No associated sites were found.

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