Site Report: ZipMart Store - Sterling

Site Name:	ZipMart Store - Sterling
Address:	38525 Swanson River RoadSterling Heights Subd, Sterling, AK 99672
File Number:	2334.26.007
Hazard ID:	23620
Status:	Active
Staff:	Bill O'Connell, 9072693057 bill.oconnell@alaska.gov
Latitude:	60.538600
Longitude:	-150.795000
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

The ZipMart Store – Sterling site was formerly operated as a fueling station beginning in 1985. Whittier Properties, Inc. owned and operated the facility from April 1990 to December 2000. A tank upgrade project in 1995 identified low level soil and groundwater contamination, but there was no evidence of a major release, and further action was not requested. The ZipMart facility closed for business in 2000 and a subsequent release investigation was performed in 2001. During the investigation, contamination was identified in several soil borings and groundwater monitoring wells. Several of the monitoring wells had up to 13 inches of free product. Based on this investigation and fuel inventory records, it was estimated that 53,000 gallons of fuel released to the environment from a break in the tanks fill pipe. Whittier Properties investigated the extent of contamination in 2001; however, the extent of was too large and they were unable or unwilling to continue. In 2002, DEC assumed the lead role in the site investigation and cleanup activities. As a result, numerous groundwater monitoring wells, product recovery wells, air-sprage wells, well points, and soil-gas probes have been installed at this site, which encompasses the former gas station property and properties adjacent to and down-gradient. Contamination generally migrated in a southeasterly direction from the source area. To date, the plume is over 3,000 feet long and 800 feet wide. A free product recovery system was operated on the site between 2002 and 2005, resulting in the recovery of over 18,000 gallons of product. Following the free-phase product recovery effort, a soil vapor extraction (SVE) system was installed and began operation in the spring of 2005. In 2007, the SVE system was expanded to the east of the existing system to allow for a larger recovery area. During the spring of 2009, an oxygen releasing compound (ORC) pilot study was completed to evaluate the effectiveness of injecting an oxygen source into the aquifer to enhance bioremediation at the down-gradient end of the contaminant plume. In May 2009, the existing 20,000 gallon UST, associated fuel dispensers, and piping were removed. Approximately 774 tons of petroleum impacted soil were excavated from the vicinity of the UST system and transported to a local thermal treatment facility for disposal. A passive soil ventilation system was installed in the excavation backfill to facilitate removal of volatile compounds and enhance oxygen movement in the subsurface. During the summer of 2011, ORC was injected in the down-gradient plume area to enhance natural attenuation to further mitigate the groundwater plume. From October 2010 to May 2013 the existing remediation system was expanded in the source area and also on the adjacent Sterling Baptist Church property to include air injection wells and additional vapor extraction (SVE) wells. The eastern system began continuous operation in May 2013. As of April 2015, the SVE systems have recovered about 11,658 gallons of gasoline vapor and 1,429 gallons of benzene vapor from the ground. A “pump and treat” system has been used every summer since 2013 to remove contaminant mass from the perched aquifer at the source area. A feasibility study in 2015 consisted of injecting 40 pounds of leftover ORC into the shallow aquifer located east of the former UST excavation to reduce contaminant concentrations in the groundwater.

Action Information

Action Date	Action	Description	DEC Staff
10/12/1995	Site Added to Database		Former Staff
10/12/1995	Leaking Underground Storage Tank Release Confirmed - Petroleum	LUST Site created in CSP for source area ID 77729 ADD; Gasoline contaminated soil & GW.	Former Staff
10/13/1995	Leaking Underground Storage Tank Cleanup Initiated - Petroleum	LCAU; Contaminated soil excavated during tank removal. : LCAU date changed DB conversion	Former Staff
8/13/1996	Update or Other Action	UPD; Departmental staff reviewed an UST closure report for this facility and noted that contamination was encountered. A Notice of Release letter was sent to the RP acknowledging that the spill had been reported.	Former Staff
11/20/1997	Update or Other Action	ADEC sends Notification of Intent to Cost Recover Letter to Current Owner: WHITTIER PROPERTIES, INC.	Former Staff
7/17/2000	Update or Other Action	Reviewed SA. No sampling conducted under the piping. No explanation of disposal of contaminated soil. New tank placed in contaminated hole.	Former Staff
1/18/2002	Underground Storage Tank Site Characterization or Assessment	ADEC received the Gilfilian report prepared for Whittier Properties. Report confirms significant contamination, free product approx. 1 foot thick on water table.	Don Fritz
1/31/2002	Leaking Underground Storage Tank Corrective Action Underway	Corrective action plan for installing additional monitor wells approved	Don Fritz
2/28/2002	Update or Other Action	Departemtn requests two corrective action plans, one for additional assessment, one for free product recovery.	Don Fritz
4/4/2002	Update or Other Action	ADEC notifies the RP that the State will be taking over response actions due to their inability to do so.	Don Fritz
4/5/2002	Release Investigation	February 2002 Release Investigation report by Gilfilian received	Don Fritz
4/16/2002	Leaking Underground Storage Tank Corrective Action Underway	Oasis work plan for continued release investigation received	Don Fritz
5/7/2002	Leaking Underground Storage Tank Corrective Action Underway	Free Product Recovery Feasibility Testing Work Plan received- approved on 6/20/02	Don Fritz
6/24/2002	Release Investigation	Oasis Continued Release Investigation Report submitted	Don Fritz
6/28/2002	Release Investigation	Free product Recovery Feasibility report submitted by Shannon & Wilson	Don Fritz
7/29/2002	Leaking Underground Storage Tank Corrective Action Underway	Department approved an ammended free product recovery work plan prepared by Shannon & Wilson	Don Fritz
11/27/2002	Release Investigation	Continued Release Investigation Report prepared by Oasis	Don Fritz
12/10/2002	Leaking Underground Storage Tank Corrective Action Underway	Contaminated sites staff approved a work plan preparred by term contractor Shannon & Wilson for installing an automated free product recovery system at the Sterling ZipMart. Three additional recovery wells were installed to assist in fuel recovery activities.	Don Fritz
8/20/2003	Update or Other Action	Free Product Recovery System Installation and Startup with this date submitted by Shannon & Wilson and received by DEC 9/8/2003	Grant Lidren
9/12/2003	Update or Other Action	Febuary and April 2003 Monitoring Report with this date prepared by Oasis and received by the DEC 9/23/2003	Grant Lidren
3/15/2004	Update or Other Action	Recovery System Modification Evaluation with this date submitted by Shannon and Wilson	Grant Lidren
5/6/2004	Update or Other Action	Provided comments to draft Shannon & Wilson groundwater report	Don Fritz
5/20/2004	Update or Other Action	Met with Darsen and Pastor DeLong to locate areas for placing 4 additional monitor wells. Will follow up with a letter	Don Fritz
5/21/2004	Update or Other Action	Sent letter to Pastor DeLong regarding placement of monitor wells	Don Fritz
5/21/2004	Update or Other Action	Met with Sven Holzinger to discuss locations for installing a monitor well. Swen stated that our preferred location would be acceptable, will be putting a house in front of it, but will not be into the area still containing vegetation.	Don Fritz
5/25/2004	Update or Other Action	Conversation with Pastor DeLong regarding location of proposed well locations. All first choice locations approved by Trustees.	Don Fritz
5/25/2004	Update or Other Action	Phone call with Don Marlowe regarding placement of another monitor well on his property. He is agreeable to our locating an additional well on-site.	Don Fritz
5/31/2004	Update or Other Action	Water and Vapor Sampling Report with this date submitted by Shannon & Wilson and received by the DEC 6/24/2004.	Grant Lidren
6/4/2004	Update or Other Action	Letter issued to Kenai Peninsula Borough regarding terms in Borough Land Use permit that require term contractor to remove monitor wells once no longer needed. The department took responsibility for removing the monitor wells once no longer needed.	Don Fritz
6/30/2004	Update or Other Action	Product Recovery Summary Report with this date submitted by Shannon & Wilson and received by the DEC 9/24/2004. A total of 13,780 gallons have been recovered to date out of the estimated 50,000 gallons spilled.	Grant Lidren
8/16/2004	Update or Other Action	Approved Shannon & Wilson proposal for ZipMart groundwater and drinking water monitoring	Don Fritz
8/24/2004	Update or Other Action	Approved Shannon & Wilson proposal for ZipMart free product recovery	Don Fritz
9/10/2004	Update or Other Action	Issued letter to the Hubbards regarding ongoing actions and response to lender liability question.	Don Fritz
10/22/2004	Update or Other Action	File number 2334.26.007 assigned and entered into the Fileroom DB and LUST DB.	Alyce Hughey
10/25/2004	Update or Other Action	Contaminated Sites staff attended a public meeting regarding the Sterling ZipMart site. Approximately 75 people attended the meeting, including Senator Tom Waggoner and Representative Mike Chenault. The audience was provided a brief summary of the site's history, and of the assessment and cleanup activities that the department has undertaken. The department also identified and presented a corrective action work plan to implement a soil vapor extraction treatment system on the Sterling Community Club property. Numerous questions from the audience were fielded.	Don Fritz
11/26/2004	Update or Other Action	Received written approval from the Sterling Community Club to implement the Vapor Extraction work plan on the Community Club property.	Don Fritz
11/29/2004	Leaking Underground Storage Tank Corrective Action Underway	Issued work plan approval for Shannon & Wilson vapor extraction work plan.	Don Fritz
12/8/2004	Update or Other Action	File shipped to AG's office for review due to public information request.	Don Fritz
1/11/2005	Update or Other Action	Water and Vapor sampling report with this date submitted by Shannon & Wilson and received by DEC 1/18/2005	Grant Lidren
2/14/2005	Release Investigation	Additional groundwater assessment activities are being conducted in association with the Sterling ZipMart contaminated site. An additional seven groundwater monitor wells, including 3 nested wells and two wells that are screened 15 feet below the water table, are being installed to provide additional information regarding contamination migration. Staff spent a considerable amount of time working with the State's term contractor on well locations.	Don Fritz
6/24/2005	Update or Other Action	Drinking Wate Sampling with this date submitted by Shannon & Wilson and received by ADEC 7/18/2005. 7 drinking wells were sampled: AK Wedding Brokers, B & D Auto, Baptist Church, Hubbard Residence, Marlowe Residence, and Sterling Lutheran Church. Contaminate only detected in B&D auto "pretreatment' drinking water sample. B&D post treatment(filtered) drinking water sample was just below DEC cleanup levels.	Linda Nuechterlein
6/24/2005	Document, Report, or Work plan Review - other	The department received Shannon & Wilson's draft Remediation System Installation and Startup report. This report was written to cover the installation and startup of the vapor extraction/thermal oxidizer system.	Former Staff
6/29/2005	Update or Other Action	Additional Site Characterization submitted by Shannon & Wilson on this date. B & D drinking water sample found to be above ADEC cleanup levels. Plume appears to be sinking at government lots 9,10, & 11 and rising at monitoring wells MW-51, MW-52 and MW-28. Plume area appears to be slowly expanding.	Grant Lidren
6/30/2005	Update or Other Action	Product Recovery Summary Report with this date submitted by Shannon & Wilson and received by DEC 6/05/2005. A total of 14, 790 gallons of gasoline has been recovered to date out of the total estimated 50,000 gallons spilled	Grant Lidren
9/9/2005	Update or Other Action	Shannon & Wilson was approved to add vent ing capabilities for recovery wells and monitor well 9 in an effort to allow additional oxygen to be introduced nto the subsurface. This is being undertaken in an effort to allow additional vapors to be removed/treated by the vapor extraction system.	Don Fritz
10/10/2005	Update or Other Action	Shannon & Wilson submitted a draft water and vapor samplingwork plan. Staff provided comments and identified a list of monitor wells that the department wanted sampled. Sampling activities began on November 7th. for	Don Fritz
10/27/2005	Update or Other Action	Shannon & Wilson was requested to provide a work plan for modifying the existing NTP for soil vapor extraction (SVE) treatment activities at the Sterling ZipMart site to include the installation and operation of a direct venting SVE system. Project staff believe that the direct discharge of vapors will be able to safely remove significant amounts of gasoline product, and should help the thermal oxidizer in removing and treating additional vapors.	Don Fritz
10/31/2005	Update or Other Action	An "Agreement to Mediated Terms and Release of Funds" document was signed by the Attorney General's office and all other parties covered under the agreement pertaining to the Sterling ZipMart insurance settlement with Zurich American Insurance Company. The Department of Law subsequently received a cashier's check for $720,349.73, representing the department’s cost recovery proceeds from the negotiated agreement to distribute the insurance proceeds from the Zurich settlement.	Don Fritz
1/23/2006	Update or Other Action	A funding request was elevated to allow for the installation of 4 additional downgradient monitor wells at the Sterling ZipMart site. The new wells are needed due to contamination migrating beyond the existing downgradient monitor wells.	Don Fritz
1/30/2006	Underground Storage Tank Site Characterization or Assessment	ADEC received a Shannon & Wilson report titled Water and Vapor Sampling, Sterling ZipMart. The report depicts that the dissolved phase contaminant plume has migrated beyond monitor wells 45 and 46. These monitor wells were the furthest downgradient monitor wells, and the last set of monitor wells between the plume and other potential downgradient receptors, including the Anderson residence and Suzie's Restaurant. Additional monitor wells will be recommended for installation.	Don Fritz
2/7/2006	Update or Other Action	Drinking water well sample results were received for wells at the Hubbard residence, the Anderson residence, Suzie's Restaurant, the Baptist Church, and the Alaska Wedding Brokers. The well at the Marlowe residence was not sampled due to the Marlowe's being out of town. No petroleum contamination was encountered in any of the well samples.	Don Fritz
2/10/2006	Underground Storage Tank Site Characterization or Assessment	A work plan for the installation of additional monitor wells downgradient of monitor wells MW-45 and MW-46 was received from Shannon & Wilson.	Don Fritz
2/27/2006	Update or Other Action	Project Manager changed from Don Fritz to Dave Pikul. File hand delivered to Anchorage by Paul Horwath.	Alyce Hughey
2/28/2006	Underground Storage Tank Site Characterization or Assessment	Repairs were made to a natural gas leak and fire-eye purge line was installed to aid in keeping the system operational during cold temperatures. The VES was restarted. The heat trace from the product recovery lines (no longer in use) was removed and installed on the vapor recovery lines in orfer to eliminate ice build-up in the lines from freezing condesate.	David Pikul
3/16/2006	Underground Storage Tank Site Characterization or Assessment	DEC requested that the term contractor provide services to complete data input and mapping efforts using GIS software for the site. All soil and groundwater data available will be input for creation of Shape files and finalized into a Geodatabase.	David Pikul
4/6/2006	Underground Storage Tank Site Characterization or Assessment	A Kenai Penninsula Borough Right-Of-Way permit was obtained for the installation of groundwater monitoring well points.	David Pikul
4/10/2006	Underground Storage Tank Site Characterization or Assessment	Permission has been obtained from ADOT&PF Maintenance Superintendent for the Kenai Penninsula for the installation of groundwater monitoring points in the Sterling Highway Right-Of-Way.	David Pikul
4/20/2006	Underground Storage Tank Site Characterization or Assessment	Five well points were installed along Lee Street and water samples collected for laboratory analysis.	David Pikul
4/25/2006	Underground Storage Tank Site Characterization or Assessment	DEC received proposal for the scope modification that will consist of collection of data to evaluate natural attenuation potential at the site.	David Pikul
4/26/2006	Underground Storage Tank Site Characterization or Assessment	Implementation of the groundwater sampling and collection of natural attenuation parameters monitoring tasks. In addition to obtaining depth to water and product thickness information, analytical samples will be collected from Monitoring Wells MW29, MW30, MW31, MW44, MW45, MW46, and MW47. The samples will be analyzed for GRO and BTEX. Natural attenuation parameters will be collected from all the monitoring wells except for the wells that have free-phase product. Field parameters to be collected will include: dissolved oxygen, nitrate, sulfate, ferrous iron, pH, temperature, ReDox, and conductivity. A low flow sampling pump will be used to facilitate sample collection.	Linda Nuechterlein
5/4/2006	Underground Storage Tank Site Characterization or Assessment	Received results of the water samples collected from the direct push well points. Four of the five well point samples contained detectable benzene concentrations. Benzene concentration in one of the four benzene containing samples exceeds the cleanup level. The highest benzene level was detected in the well point near the Sterling Highway and Lee Street intersection.	David Pikul
5/8/2006	Underground Storage Tank Site Characterization or Assessment	DEC requested term contractor provide services to decommission MW-31 nested groundwater monitoring wells at the site.	David Pikul
5/10/2006	Underground Storage Tank Site Characterization or Assessment	DEC received the proposal for the decommissioning of monitoring wells MW-31 and MW-10.	David Pikul
5/16/2006	Underground Storage Tank Site Characterization or Assessment	MW-10 and MW-31 were decommissioned.	David Pikul
5/24/2006	Underground Storage Tank Site Characterization or Assessment	A flame rod was installed on the thermal oxidizer burner	David Pikul
5/26/2006	Underground Storage Tank Site Characterization or Assessment	Eleven monitoring wells were sampled for natural attenuation parameters, GRO, and BTEX between 5/24 and 5/26. Utility locates were made along Barbara and Lee Streets. Six locations were staked for new monitoring wells.	David Pikul
5/29/2006	Underground Storage Tank Site Characterization or Assessment	DEC received the Spring 2006 Groundwater Monitoring Report and the Spring VES Monitoring & Pilot Study Report.	David Pikul
6/3/2006	Underground Storage Tank Site Characterization or Assessment	Six new groundwater monitoring wells (MW-54 - MW-59) were installed on 5/30 and 5/31. Three wells each are located along Lee Street and Barbara Street on the block south of the Sterling Highway. The 10-foot 0.01-inch slot screens were placed to span the water table and have around six feet of water column. The wells have above-ground completions, and are located off the roadway, but within the Borough right-of-way. The six new wells were developed on 6/1, and sampled for GRO, BTEX, and natural attenuation parameters on 6/2.	David Pikul
6/12/2006	Underground Storage Tank Site Characterization or Assessment	A vapor extraction pilot test was run on each of Monitoring Wells MW37, 43, 42, 8, 40, 7, and 6 (in chronological order) last week. Laboratory results from the eleven wells sampled along the "high concentration front" were received last week.	David Pikul
6/19/2006	Underground Storage Tank Site Characterization or Assessment	Groundwater laboratory data received for new wells MW-54 through MW-59. Data indicates that leading edge of the plume is at Barbara Street.	David Pikul
6/28/2006	Update or Other Action	Drinking water sampling report received from Shannon & Wilson with this date.Sampling events occurred on 1/18/2006 & 4/5/2006. 6 residence were sampled; Baptist, Wedding, Suzies, Anderson, Hubbard, & Marlowe. Contaminates were not detected in any of the sampling events.	Grant Lidren
6/30/2006	Update or Other Action	Spring 2006 Groundwater Investigation with this date submitted by Shannon & Wilson and received by DEC 7/05/2006. The report contains groundwater elevations and product thickness, plume delineation, groundwater charcterization and monitoring well maintenance. Front of plume with contaminats above ADEC clean up levels is between Lee Street and Barbara Street-2 samples in well MW-56 were above ADEC cleanup levels . Increase in contaminat levels found on Western edge of wetland. Three monitoring wells were decomissioned and several repaired.	Linda Nuechterlein
6/30/2006	Update or Other Action	Spring 2006 Vapor Extraction System Monitoring And Pilot Study with this date submitted by Shannon & Wilson and received by the DEC 7/05/2006. Remediation effforts and the vapor extraction system have removed 16,790 gallons of gasoline to date.	Linda Nuechterlein
7/5/2006	Underground Storage Tank Site Characterization or Assessment	DEC received the GIS deliverable.	David Pikul
8/3/2006	Underground Storage Tank Site Characterization or Assessment	NTP 1890281429 has been issued to Shannon & Wilson for continued operation and maintenance of the VES	Linda Nuechterlein
8/7/2006	Underground Storage Tank Site Characterization or Assessment	The two VES blowers were activated on 8/4/06.	Linda Nuechterlein
9/21/2006	Document, Report, or Work plan Review - other	A review of the Spring 2006 GW and 2006 Soil Vapor Extraction System (SVES) operation reports for the Sterling – ZipMart site has been completed. The Soil Vapor Extraction System (SVES) continues to operate and vapor concentrations collected during system operation indicate good vapor recovery opportunity. Following system operation during the later portion of the summer, the vapor concentrations have been reduced below 10,000 ppm, allowing for better quantification of recovered vapor. Monitoring of ambient air benzene concentrations indicates acceptable human exposure. Funding has been approved and a Notice To Proceed (NTP) issued to Shannon & Wilson for the installation of a second SVES shed and operation/maintenance of both the current and new SVE systems. A Request For Proposal (RFP) has been issued to the term contractor soliciting a proposal to decommission/repair selected site monitoring wells (MWs), and to sample both MWs and DW wells during a spring monitoring event	Linda Nuechterlein
9/25/2006	Update or Other Action	A Water Quality Monitoring and Soil Vapor Extraction System Operation Work Plan dated September 21, 2006 was approved. The project purpose is to conduct groundwater, drinking water, and surface water sampling; and to evaluate the effectiveness of the on-site Soil Vapor Extraction System (SVES).	Linda Nuechterlein
10/30/2006	Leaking Underground Storage Tank Corrective Action Underway	A work plan for the Sterling ZipMart site for continued operation of the existing Soil Vapor Extraction System (SVES) and installation of a new SVES to the east of the existing system was approved. The project purpose is to continue operation and maintenance of the existing SVES and develop a plan to allow treatment and cleanup of the secondary source area in order to reduce further migration of the contaminant plume.	Linda Nuechterlein
1/27/2007	Document, Report, or Work plan Review - other	Fall 2006 GW, SW & SVE Monitoring Report dated 12/7/06 by S&W was reviewed by ADEC. Lab data checkliist from S&W was included with this report. ADEC staff reviewed lab data and filled-out a checklist which was placed in the file. CSM was also completed and placed in the file.	Linda Nuechterlein
3/1/2007	Update or Other Action	CS completed review of the Groundwater Monitoring Program Work Plan, Former Sterling Zip Mart, 38525 Swanson River Road, Sterling, Alaska, ADEC Spill NO: 95-23-00-285-01; UST Facility ID NO: 2924 dated December 28, 2006 prepared by Shannon & Wilson. Included in the review is the revised TABLE 1 - WELL MONITORING PROGRAM submitted by e-mail on February 20, 2007 (attached). Approval letter issued to S&W for the work plan and amended table 1. Several of the wells listed in the monitoring plan will be assessed during the April 2007 monitoring event. Based on the findings of the April 2007 event, modifications may be made to the plan for the Fall 2007 and spring 2008 as noted in Table 1.	Linda Nuechterlein
3/12/2007	Exposure Tracking Model Ranking	Initial ranking completed.	Linda Nuechterlein
4/18/2007	Update or Other Action	The Spring 2007 groundwater sampling at Sterling Zipmart was completed on April 18. The Soil Vapor Extraction (SVE) system was most recently monitored on April 18 and May 14, 2007. The existing soil vapor extraction system (SVES) is currently being upgraded and expanded to allow for installation of a SVE shed and associated system components to the east of the existing SVES on the Sterling Baptist Church property. The existing SVES continues to extract vapors from the primary source area however, this expansion to the east would allow for treatment and cleanup of the secondary source area on the Sterling Baptist Church property.	Linda Nuechterlein
5/15/2007	Update or Other Action	The existing soil vapor extraction system (SVES) is currently being upgraded and expanded to allow for installation of a SVE shed and associated system components to the east of the existing SVES on the Sterling Baptist Church property. The existing SVES continues to extract vapors from the primary source area however, this expansion to the east would allow for treatment and cleanup of the secondary source area on the Sterling Baptist Church property. On May 15, 16, and 17 our state term contractor, Shannon & Wilson, worked with B.C. Excavating and Toklat Electric to install underground lines from Monitoring Wells MW7 and MW40 to the west blower shed, which was moved to the Sterling Baptist Church (SBC) property. The ground was found to be frozen 6 to 8 inches below the surface, making trench excavation difficult, and the quality of the backfill poor. Fence installation will be completed after Homer Electric provides service to Blower 2.	Linda Nuechterlein
7/5/2007	Update or Other Action	GIS based map dated 6/29/2007 submitted by Shannon & Wilson. Analytical results from Fall 2006 and Spring 2007 are incorporated in existing GIS-based map	Linda Nuechterlein
9/4/2007	Update or Other Action	Spring 2007 soil vapor extraction (SVE) system monitoring and modification report submitted by Shannon & Wilson on this date. Through the winter the SVE system removed an estimated 750 gallons of gasoline.	Linda Nuechterlein
9/11/2007	Update or Other Action	Received Spring 2007 Monitoring report dated August 30, 2007. QA/QC was completed by the consultant. Lab checklists which were completed by ADEC are stapled in the back of this report. Groundwater samples were collected from 27 monitoring wells. In addition MW60 was installed along the southern edge of the Sterling Highway. Report conclusions indicate 2007 measurments of the FP plume, found the least amount of measurable free product to date. Although operation of the remediation system and natural attenuation continue to reduce contaminant concentrations in the source area, there was an increase in benzene and GRO concentrations on the edge of the plume. The Kenai River is approximately 3/4 mile from the leading edge of the plume and is not in danger of being impacted by the contamination.	Linda Nuechterlein
10/12/2007	Update or Other Action	Groundwate Monitoring and Soil Vapor Extraction System(SVES) Operation Work Plan submitted by Shannon & Wilson.	Linda Nuechterlein
11/19/2008	Site Visit	On this date, a site visit was conducted by the ADEC project manager (PM) with the CSP term contractor (Shannon & Wilson) present. The Soil Vapor Extraction (SVE) system was monitored by the term contractor/S&W which included the following activities: a general inspection for damage and safety hazards; field measurements of vapor concentrations, analytical sampling and performing any necessary maintenance. Various scenarios for placement of ORC wells were considered and injection point locations discussed. The ADEC PM and the term contractor also canvassed the site and surrounding area to ascertain whether any new drinking water wells had been installed that could be potentially impacted by the hydrocarbon plume.	Linda Nuechterlein
4/27/2009	Update or Other Action	The Spring 2009 groundwater monitoring round was completed between Tuesday, April 21 and Saturday, April 25, 2009 by the ADEC term contractor. Water/product levels were measured on April 21, and floating product was not encountered. A few of the planned wells were not measured due to surface ponds or ice. Samples were collected from 21 monitoring wells, including the new nested Wells MW61S & MW61D at the ORC pilot study site. Samples were collected from three drinking water systems. The water was off at Suzie’s Café and the ZipMart building. The SVE system was monitored and sampled on April 20 by the CSP term contractor, and various adjustments, maintenance, and field screening were performed on April 25, 26, and 27.	Linda Nuechterlein
5/1/2009	Update or Other Action	It was reported by the CSP term contractor on this date that installations of 20 Oxygen Release Compound (ORC) injection wells and one nested monitoring well (MW) were completed between April 20 and Thursday April 23, 2009. Eighty pounds of ORC Advanced were injected into the 20 wells on Friday, April 24 and Monday April 27. In general the work proceeded smoothly.	Linda Nuechterlein
10/14/2009	Document, Report, or Work plan Review - other	ADEC reviewed & approved a work plan dated October 8, 2009 for monitoring of groundwater(GW) & drinking water wells (DW); as well as continued monitoring & operation of the soil vapor extraction system (SVES). Updates to the fiscal year (FY) 2010 GW monitoring program were summarized in Table 1 which identifies GW monitoring wells & DW wells to be monitored, sampled, repaired, and decommissioned, as well as the frequency of monitoring proposed for FY 2010. An approval letter was sent to S&W on this date.	Linda Nuechterlein
10/22/2009	Document, Report, or Work plan Review - other	Reviewed & approved the report documenting Spring 2009 groundwater monitoring (GW), drinking water (DW) sampling, and soil vapor extraction system (SVES) operation monitoring; as well as the injection of oxygen release compound (ORC) to enhance natural attenuation in groundwater at the plume front. This is the first monitoring round where measureable LNAPL (light nonaqueous phase liquid) was not confirmed in any of the Free Product Zone wells tested. Results of natural attenuation testing support previously observed trends and suggest that aerobic degradation is occurring around the edges and within the down-gradient portions of the contaminant plume. VOCs (volatile organic compounds) were not detected in samples taken from three DW systems. The SVES continued operation between October and April 2009. The concentrations of hydrocarbons measured in vapors removed from the subsurface have declined to the lowest levels measured since the SVES began operation. This along with the lack of measurable LNAPL in wells suggests that the SVES is reducing the mass of volatile hydrocarbons in the subsurface	Linda Nuechterlein
6/22/2010	Site Visit	Traveled to Soldotna to conduct a site visit at the Sterling Zipmart site and meet with the ADEC term contactor. Pilot tests are being conducted to evaluate treatment options to supplement the Soil Vapor Extraction (SVE) system in order to reduce the mass of gasoline contaminants available for transport down-gradient. Treatment technologies being considered include air sparging and in-situ air stripping/recirculation using existing recovery wells. Both technologies add oxygen to the groundwater to enhance biological degradation, and move volatile contaminants from the dissolved phase to the vapor phase	Linda Nuechterlein
8/4/2010	Update or Other Action	Reviewed the Spring 2010 Monitoring & Remediation Report, which documents Spring 2010 groundwater monitoring, drinking water (DW) sampling; remediation system pilot study results and recommendations; continued operation and monitoring of the soil vapor extraction system (SVES); and further characterization of the northeastern (NE) plume area. Recent sampling results indicate that benzene is moving through a greater thickness of the aquifer in the NE plume area than was indicated by previous testing results in 2005. The results also suggest that the aquifer formation and distribution of contaminants are stratified. Installation and sampling of additional nested monitor wells completed at different depths will be included in the next SOA Request for Proposal.	Linda Nuechterlein
8/12/2010	Update or Other Action	A Request for Proposal (RFP) for the Former Sterling ZipMart to include the following activities: (1) design and installation of Air Sparge (AS) and Soil Vapor Extraction (SVE) wells and/or modifications to the existing SVE system; (2) continued operation, maintenance and monitoring of the remediation system; (3) monitoring of water quality by sampling groundwater and drinking water wells; (4) focused feasibility study to evaluate viable treatment options for the contaminated plume front; (5) further characterize soil and groundwater in the northeast plume front, and (6) removal of contaminated source area on the Zipmart Property was sent out on Aug. 12th. Since contamination at this “State Lead” site is a result of leaks from an underground storage tank (UST) system subject to 18 AAC 78 regulations, cleanup is eligible under American Recovery and Reconstruction Act (ARRA) funding. The deadline for all work to be completed under ARRA is September 30, 2011.	Linda Nuechterlein
12/3/2010	Update or Other Action	Drilling of air injection and vapor extraction wells; remediation system trenching; and installation of monitoring wells (east of Swanson River Road) have now been completed at the Sterling Zipmart site. The newly installed soil vapor extraction (SVE) wells are now operational; however, the air sparge blowers are on still on backorder. In addition, three down-gradient monitoring wells (MW71N, MW72N, MW73N) were completed and sampled. This work is being funded by American Recovery and Reinvestment Act (ARRA) funds which are due to expire in September 2011.	Linda Nuechterlein
12/29/2010	Update or Other Action	On December 29, 2010 the remediation system at the Sterling Zipmart site was monitored by the CSP term contractor, Shannon and Wilson (S&W). S&W reported that the four blowers were running, and a temporary fence is now in place around the remediation sheds on the Zipmart property. No problems with the air injection system were noted. The Soil Vapor Extraction (SVE) vapor screening results again show that the new north system (Blower 2) is pulling in most of the hydrocarbons. Groundwater dissolved oxygen was also measured in five monitoring wells. This work is being funded by American Recovery and Reinvestment Act (ARRA) funds which are due to expire in September 2011.	Linda Nuechterlein
2/24/2011	Update or Other Action	Installation of the expanded remediation system at the Sterling Zipmart to include air injection wells, was completed by end of December 2010. Since the start of 2011, the CSP term contractor, Shannon & Wilson has made three site visits to the Sterling Zipmart and reported that the remediation system is running steadily. On each of the site visits dissolved oxygen (DO) was measured in three new nested monitoring wells in addition to other select wells, to evaluate the effectiveness of the remediation system. Lab results from the most recent Fall 2010 groundwater sampling event indicate the plume front is still expanding with benzene increasing in several monitoring wells located along the leading edge of the plume. It is anticipated that the Fall Monitoring report will be completed and submitted to DEC soon. Data from this report will assist in evaluating the viability of treatment options for the plume front.	Linda Nuechterlein
4/11/2011	Update or Other Action	Results from recent groundwater sampling indicates that groundwater adjacent to property located at 34684 Sterling Highway Ware Residence) may be impacted by the Sterling Zipmart plume. On March 15, 2011 a letter was sent to notify the current owner and resident that groundwater on her property may have been impacted by hydrocarbon contamination based on recent sampling results from adjacent property. On April 11, 2011 the CSP term contractor sampled the DW wells at this residence.	Linda Nuechterlein
4/28/2011	Update or Other Action	Spring 2011 Well Monitoring Program for the Sterling ZipMart project which is summarized in “Table 1 – Spring 2011 Well Monitoring Program" was reviewed and approved by DEC. The Spring monitoring event is scheduled to begin on May 2, 2011. DEC staff will conduct a site visit during that week.	Linda Nuechterlein
5/4/2011	Site Visit	Site visit by ADEC staff to inspect Spring Monitoring Event in progress this week.	Linda Nuechterlein
9/1/2011	Site Visit	Conduct a site inspection during intallation of ORC Lines A - C which is being funded with ARRA grant.	Linda Nuechterlein
10/24/2011	Document, Report, or Work plan Review - other	Wells identified in Table 1- FY2012 are approved for sampling under the Fall 2011 groundwater monitoring program.	Linda Nuechterlein
11/18/2011	Document, Report, or Work plan Review - other	Fiscal Year 2012 Operations Plan, and Spring 2011 Monitoring Report are approved.	Linda Nuechterlein
3/1/2012	Update or Other Action	Fall 2011 Zipmart groundwater monitoring report was approved.	Linda Nuechterlein
4/26/2012	Update or Other Action	On this date approval for the Zipmart Spring 2012 groundwater sampling program was sent to S&W. EDB will be sampled in the B&D Auto and Ware Residence drinking water wells, as well as MW 71D.	Linda Nuechterlein
6/14/2012	Site Visit	CS project manager conducted site visit on this date.	Linda Nuechterlein
8/10/2012	Update or Other Action	Funding was approved to monitor water quality of groundwater and drinking water wells; operate, maintain and monitor the Soil Vapor Extraction (SVE); and Air Sparge (AS) remediation system ; and cover costs associated with obtaining components needed to expand the air sparging (AS) remediation system .	Linda Nuechterlein
9/6/2012	Update or Other Action	Starting on September 6th a Pilot Test was initiated to determine the feasibility of In-Situ Chemical Oxidation at the Sterling-Zipmart site.	Linda Nuechterlein
10/1/2012	Update or Other Action	Received Draft Zipmart Spring 2012 Monitoring report from CSP term contractor (Shannon & Wilson) for agency review on Oct. 1st. This comprehensive report includes groudnwater monitoring of ~ 100 wells; drinking water well sampling; remediation system operation and monitoring; installation of additional monitorng wells; and investigation of a sink hole.	Linda Nuechterlein
10/25/2012	Update or Other Action	Completed review of the Draft Zipmart Spring 2012 Monitoring report including lab review checklists. Provided written comments/edits to the term contractor (S&W) and followed-up with a phone call to discuss on this date.	Linda Nuechterlein
11/2/2012	Update or Other Action	“Table 1 – Fiscal Year 2013 Well Monitoring Program” for Sterling Zipmart is approved. The term contractor plans to begin the fall sampling round on Tuesday, November 6, 2012.	Linda Nuechterlein
11/27/2012	Update or Other Action	Zipmart Spring 2012 Monitoring Report (received Oct. 2012) was approved. This report represents remediation and groundwater monitoring conducted between Dec. 2011 and May 2012.	Linda Nuechterlein
12/14/2012	Update or Other Action	As of this date, the remediation system upgraded with 14 new air sparge wells. Also one new nested monitoring well pair have been installed, the compressor shed placed and wired in, and a temporary fence around the shed.	Linda Nuechterlein
4/18/2013	Document, Report, or Work plan Review - other	Reviewed and approved FY 13 Spring Monitoring work plan.	Linda Nuechterlein
6/5/2013	Document, Report, or Work plan Review - other	Spring 2013 Additional Services Work Plan dated May 2013 approved. The planned work includes pumping and treating contaminated water from the shallow perched aquifer at the source area to further reduce contaminant mass; installing a remote monitoring system to improve remediation system efficiency; and decommissioning out-of-use monitoring wells.	Linda Nuechterlein
6/20/2013	Document, Report, or Work plan Review - other	Zipmart Fall 2012 Monitoring and Remediation Report dated March 2013 is approved. Lab review checklists included with this report were also reviewed and approved.	Linda Nuechterlein
6/24/2013	Update or Other Action	Funding approved for continued operation of remediation systems. NTP issued to term contractor.	Linda Nuechterlein
6/25/2013	Document, Report, or Work plan Review - other	Decommissioning of various monitor wells including MW32, MW34, MW35, MW38, MW39, RW11, and WP-2 approved by DEC.	Linda Nuechterlein
9/20/2013	Document, Report, or Work plan Review - other	Spring 2013 Monitoring and Remediation report for Sterling Zipmart approved by DEC. Lab review checklists included with this report were also reviewed and approved.	Linda Nuechterlein
10/22/2013	Document, Report, or Work plan Review - other	Revisions to Table 1, for Fall 2013 Well Monitoring Plan are approved.	Linda Nuechterlein
4/17/2014	Document, Report, or Work plan Review - other	Revised Report for 2013 Fall Monitoring is received by ADEC on this day. The report includes groundwater monitoring & remediation work conducted between June - November 2013. The project scope included GW monitoring; O&M of remediation systems; installing and operating a pump and treat system; installation of a remote monitoring system; and MW decommissioning. Revisions requested by ADEC have been made and report is approved.	Linda Nuechterlein
4/21/2014	Update or Other Action	Groundwater monitoring included the biannual water level measurement and sampling event conducted April 21 - April 23, 2014.	Linda Nuechterlein
4/24/2014	Update or Other Action	The Pump and Treat System (P&T) system that was operated during the summer of 2013 to remove contaminant mass from the perched aquifer at the source area, was re-started for operation during Summer 2014.	Linda Nuechterlein
5/30/2014	Update or Other Action	The term contractor inspected the site on Friday 5/30 and the following was reported to DEC. The P&T system is operational; inflow and tank samples were collected. The North and East AS systems were running fine. The hydrocarbon concentrations in the SVE exhaust continue to decrease slowly. Suzie's Cafe (downgradient of the plume) is now open, and a water sample was collected from their drinking water well.	Linda Nuechterlein
8/5/2014	Site Visit	CSP staff conducted a site inspection and met with the Contaminated Sites Program (CSP) term contractor (Shannon and Wilson) who was conducting monitoring and maintenance activities.	Linda Nuechterlein
10/27/2014	Document, Report, or Work plan Review - other	Groundwater monitoring plan proposed in Table 1 - Fall 2014 Monitoring Program is approved with the condition to add MW68S to the sampling plan.	Linda Nuechterlein
1/13/2015	Document, Report, or Work plan Review - other	Draft Biannual Monitoring and Remediation Report (received Nov. 21, 2014) is approved. The report presents the results of Shannon & Wilson's remediation & groundwater (GW) monitoring work conducted between Nov. 2013 and June 2014 at the former Sterling Zipmart site. The project scope included GW monitoring, drinking water sampling, modification of the eastern air injection system (EAIS), and operation and maintenance of the active remediation systems.	Linda Nuechterlein
4/23/2015	Update or Other Action	Zipmart groundwater monitoring program for Spring 2015 was approved on this date. See "Table 1- Spring 2015 Well Monitoring Program" for sampling details.	Linda Nuechterlein
6/24/2015	Site Visit	Site visit to observe ORC injections, SVE, sprage, and pump and treat systems.	Joshua Barsis
11/4/2015	Document, Report, or Work plan Review - other	Reviewed the Fiscal Year 2015 Monitoring and Remediation Report, dated October 2015 (all activities were performed between July 2014 and June 2015). Activities described in the report mainly consisted of groundwater monitoring, drinking water well sampling, operation and monitoring of the active remediation systems (air-sparge, soil-vapor extraction, and pump and treat), and an oxygen releasing compound (ORC) application feasibility study. The objective of the ORC feasibility study was to determine if applying ORC to the subsurface would be effective in enhancing bio-attenuation and reducing contaminant mass in the perched aquifer on the ZipMart property. 1,160 pounds of ORC was poured into 29 soil borings that were advanced to 13 feet below ground surface. Monitoring Well MW3b was installed down-gradient of the ORC application for the purpose of monitoring attenuation where ORC was injected. Initial sample results from MW3b were 466 mg/L GRO, 89 mg/L benzene, 123 mg/L toluene, 5.33 mg/L ethylbenzene, and 26.8 mg/L xylenes.	Joshua Barsis
7/6/2016	Document, Report, or Work plan Review - other	Reviewed the Fiscal Year 2016 Monitoring and Remediation Report, dated June 2016 (all activities were performed between July 2015 and June 2016). Activities described in the report mainly consisted of groundwater monitoring, drinking water well sampling, operation and monitoring of the active remediation systems (air-sparge, soil-vapor extraction, and pump and treat), and associated well and systems maintenance. Next report should be received July or August 2017.	Joshua Barsis
2/16/2018	Document, Report, or Work plan Review - other	Reviewed the Fiscal Year 2017 Monitoring and Remediation Report, dated November 2017 (all activities were performed between July 2016 and June 2017). Activities described in the report mainly consisted of groundwater monitoring, drinking water well sampling, operation and monitoring of the active remediation systems (air-sparge, soil-vapor extraction, and pump and treat), and associated well and systems maintenance. Next report should be received November 2018.	Joshua Barsis
7/5/2018	Document, Report, or Work plan Review - other	Reviewed the Fiscal Year 2018 Monitoring and Remediation Report, dated June 2018. Activities described in the report mainly consisted of groundwater monitoring, drinking water well sampling, operation and monitoring of the active remediation systems (air-sparge, soil-vapor extraction, and pump and treat), and associated well and systems maintenance.	Joshua Barsis
7/8/2019	Document, Report, or Work plan Review - other	Reviewed the Fiscal Year 2019 Monitoring and Remediation Report, dated June 2019. Activities described in the report mainly consisted of groundwater monitoring, drinking water well sampling, operation and monitoring of the active remediation systems (air-sparge, soil-vapor extraction, and pump and treat), and associated well and systems maintenance.	Joshua Barsis
7/1/2020	Site Characterization Report Approved	The department received the Fiscal Year 2020 Monitoring and Remediation Sterling ZipMart report. The report detailed maintenance of the wells, the soil vapor extraction and air sparging systems, and use of the pump and treat system. In May 2020, drinking water wells at the Sterling Baptist Church, Bennett residence, and Moose River Dental were collected. None of the target anayltes were detected. Groundwater monitoring occurred in Fall 2019 and Spring 2020, alternating groups of wells. Groundwater flow direction was east-southeast (as previously observed). During the alternate sampling events, plume front wells (MW65S, MW66S, MW66M, MW77S, and MW77D) were sampled. Nested pair MW66S and MW66M benzene concentrations continue to be stable since 2014. MW65S has continued to decrease since 2017, while MW65D has been increasing during the same time. During sampling events plume boundary wells (MW8, MW33, MW52, MW56, MW56D, MW25S, MW25D, MW44D, MW68D, and RW17) were sampled. Benzene in MW25S, MW56D, MW56, and MW52 (south boundary wells) appears to be trending downward since 2014. Benzene in wells MW23D, MW33, MW40, MW71S, MW72S have decreased since 2013 after the initiation of the east air sparge system. PVC casings for wells MW2, MW25S, and MW25D were cut down in 2020.	Lisa Krebs-Barsis
11/1/2021	Site Characterization Report Approved	The department received the Fiscal Year 2021 Monitoring and Remediation Sterling ZipMart report. The report detailed sampling and maintenance of the wells, the soil vapor extraction and air sparging systems, and use of the pump and treat system. In May 2021, drinking water samples at the Sterling Baptist Church, the Ware, Marlow, and Hubbard residences, and the B&D Auto Repair were collected. Target petroleum constituents were not detected. Groundwater monitoring occurred in Fall 2020 and Spring 2021, alternating groups of wells. Groundwater flow direction was east-southeast (as previously observed).	Lisa Krebs-Barsis
12/7/2021	Meeting or Teleconference Held	Meeting with supervisor for handoff notes. Fiscal Year 2020 Monitoring and Remediation Sterling ZipMart, 38525 Swanson River Road Sterling, Alaska dated, July 2020 and Fiscal Year 2021 Monitoring and Remediation Sterling ZipMart, 38525 Swanson River Road Sterling, Alaska, dated November 2021 reports are being reviewed by supervisor and actions will be updated once complete.	Jessica Hall
2/1/2024	Document, Report, or Work plan Review - other	Report approved for remediation and maintenance activities from July 2021 to December 2023. During this period, the remediation systems were maintained and significant repairs were made following the collapse of the structure which severed power to some of the systems. A new power pole was installed in the KPB right-of-way and the systems were brought back online.	Lisa Krebs-Barsis

Action Date

Action

Description

DEC Staff

10/12/1995

Site Added to Database

Former Staff

10/12/1995

Leaking Underground Storage Tank Release Confirmed - Petroleum

LUST Site created in CSP for source area ID 77729 ADD; Gasoline contaminated soil & GW.

Former Staff

10/13/1995

Leaking Underground Storage Tank Cleanup Initiated - Petroleum

LCAU; Contaminated soil excavated during tank removal. : LCAU date changed DB conversion

Former Staff

8/13/1996

Update or Other Action

UPD; Departmental staff reviewed an UST closure report for this facility and noted that contamination was encountered. A Notice of Release letter was sent to the RP acknowledging that the spill had been reported.

Former Staff

11/20/1997

Update or Other Action

ADEC sends Notification of Intent to Cost Recover Letter to Current Owner: WHITTIER PROPERTIES, INC.

Former Staff

7/17/2000

Update or Other Action

Reviewed SA. No sampling conducted under the piping. No explanation of disposal of contaminated soil. New tank placed in contaminated hole.

Former Staff

1/18/2002

Underground Storage Tank Site Characterization or Assessment

ADEC received the Gilfilian report prepared for Whittier Properties. Report confirms significant contamination, free product approx. 1 foot thick on water table.

Don Fritz

1/31/2002

Leaking Underground Storage Tank Corrective Action Underway

Corrective action plan for installing additional monitor wells approved

Don Fritz

2/28/2002

Update or Other Action

Departemtn requests two corrective action plans, one for additional assessment, one for free product recovery.

Don Fritz

4/4/2002

Update or Other Action

ADEC notifies the RP that the State will be taking over response actions due to their inability to do so.

Don Fritz

4/5/2002

Release Investigation

February 2002 Release Investigation report by Gilfilian received

Don Fritz

4/16/2002

Leaking Underground Storage Tank Corrective Action Underway

Oasis work plan for continued release investigation received

Don Fritz

5/7/2002

Leaking Underground Storage Tank Corrective Action Underway

Free Product Recovery Feasibility Testing Work Plan received- approved on 6/20/02

Don Fritz

6/24/2002

Release Investigation

Oasis Continued Release Investigation Report submitted

Don Fritz

6/28/2002

Release Investigation

Free product Recovery Feasibility report submitted by Shannon & Wilson

Don Fritz

7/29/2002

Leaking Underground Storage Tank Corrective Action Underway

Department approved an ammended free product recovery work plan prepared by Shannon & Wilson

Don Fritz

11/27/2002

Release Investigation

Continued Release Investigation Report prepared by Oasis

Don Fritz

12/10/2002

Leaking Underground Storage Tank Corrective Action Underway

Contaminated sites staff approved a work plan preparred by term contractor Shannon & Wilson for installing an automated free product recovery system at the Sterling ZipMart. Three additional recovery wells were installed to assist in fuel recovery activities.

Don Fritz

8/20/2003

Update or Other Action

Free Product Recovery System Installation and Startup with this date submitted by Shannon & Wilson and received by DEC 9/8/2003

Grant Lidren

9/12/2003

Update or Other Action

Febuary and April 2003 Monitoring Report with this date prepared by Oasis and received by the DEC 9/23/2003

Grant Lidren

3/15/2004

Update or Other Action

Recovery System Modification Evaluation with this date submitted by Shannon and Wilson

Grant Lidren

5/6/2004

Update or Other Action

Provided comments to draft Shannon & Wilson groundwater report

Don Fritz

5/20/2004

Update or Other Action

Met with Darsen and Pastor DeLong to locate areas for placing 4 additional monitor wells. Will follow up with a letter

Don Fritz

5/21/2004

Update or Other Action

Sent letter to Pastor DeLong regarding placement of monitor wells

Don Fritz

5/21/2004

Update or Other Action

Met with Sven Holzinger to discuss locations for installing a monitor well. Swen stated that our preferred location would be acceptable, will be putting a house in front of it, but will not be into the area still containing vegetation.

Don Fritz

5/25/2004

Update or Other Action

Conversation with Pastor DeLong regarding location of proposed well locations. All first choice locations approved by Trustees.

Don Fritz

5/25/2004

Update or Other Action

Phone call with Don Marlowe regarding placement of another monitor well on his property. He is agreeable to our locating an additional well on-site.

Don Fritz

5/31/2004

Update or Other Action

Water and Vapor Sampling Report with this date submitted by Shannon & Wilson and received by the DEC 6/24/2004.

Grant Lidren

6/4/2004

Update or Other Action

Letter issued to Kenai Peninsula Borough regarding terms in Borough Land Use permit that require term contractor to remove monitor wells once no longer needed. The department took responsibility for removing the monitor wells once no longer needed.

Don Fritz

6/30/2004

Update or Other Action

Product Recovery Summary Report with this date submitted by Shannon & Wilson and received by the DEC 9/24/2004. A total of 13,780 gallons have been recovered to date out of the estimated 50,000 gallons spilled.

Grant Lidren

8/16/2004

Update or Other Action

Approved Shannon & Wilson proposal for ZipMart groundwater and drinking water monitoring

Don Fritz

8/24/2004

Update or Other Action

Approved Shannon & Wilson proposal for ZipMart free product recovery

Don Fritz

9/10/2004

Update or Other Action

Issued letter to the Hubbards regarding ongoing actions and response to lender liability question.

Don Fritz

10/22/2004

Update or Other Action

File number 2334.26.007 assigned and entered into the Fileroom DB and LUST DB.

Alyce Hughey

10/25/2004

Update or Other Action

Contaminated Sites staff attended a public meeting regarding the Sterling ZipMart site. Approximately 75 people attended the meeting, including Senator Tom Waggoner and Representative Mike Chenault. The audience was provided a brief summary of the site's history, and of the assessment and cleanup activities that the department has undertaken. The department also identified and presented a corrective action work plan to implement a soil vapor extraction treatment system on the Sterling Community Club property. Numerous questions from the audience were fielded.

Don Fritz

11/26/2004

Update or Other Action

Received written approval from the Sterling Community Club to implement the Vapor Extraction work plan on the Community Club property.

Don Fritz

11/29/2004

Leaking Underground Storage Tank Corrective Action Underway

Issued work plan approval for Shannon & Wilson vapor extraction work plan.

Don Fritz

12/8/2004

Update or Other Action

File shipped to AG's office for review due to public information request.

Don Fritz

1/11/2005

Update or Other Action

Water and Vapor sampling report with this date submitted by Shannon & Wilson and received by DEC 1/18/2005

Grant Lidren

2/14/2005

Release Investigation

Additional groundwater assessment activities are being conducted in association with the Sterling ZipMart contaminated site. An additional seven groundwater monitor wells, including 3 nested wells and two wells that are screened 15 feet below the water table, are being installed to provide additional information regarding contamination migration. Staff spent a considerable amount of time working with the State's term contractor on well locations.

Don Fritz

6/24/2005

Update or Other Action

Drinking Wate Sampling with this date submitted by Shannon & Wilson and received by ADEC 7/18/2005. 7 drinking wells were sampled: AK Wedding Brokers, B & D Auto, Baptist Church, Hubbard Residence, Marlowe Residence, and Sterling Lutheran Church. Contaminate only detected in B&D auto "pretreatment' drinking water sample. B&D post treatment(filtered) drinking water sample was just below DEC cleanup levels.

Linda Nuechterlein

6/24/2005

Document, Report, or Work plan Review - other

The department received Shannon & Wilson's draft Remediation System Installation and Startup report. This report was written to cover the installation and startup of the vapor extraction/thermal oxidizer system.

Former Staff

6/29/2005

Update or Other Action

Additional Site Characterization submitted by Shannon & Wilson on this date. B & D drinking water sample found to be above ADEC cleanup levels. Plume appears to be sinking at government lots 9,10, & 11 and rising at monitoring wells MW-51, MW-52 and MW-28. Plume area appears to be slowly expanding.

Grant Lidren

6/30/2005

Update or Other Action

Product Recovery Summary Report with this date submitted by Shannon & Wilson and received by DEC 6/05/2005. A total of 14, 790 gallons of gasoline has been recovered to date out of the total estimated 50,000 gallons spilled

Grant Lidren

9/9/2005

Update or Other Action

Shannon & Wilson was approved to add vent ing capabilities for recovery wells and monitor well 9 in an effort to allow additional oxygen to be introduced nto the subsurface. This is being undertaken in an effort to allow additional vapors to be removed/treated by the vapor extraction system.

Don Fritz

10/10/2005

Update or Other Action

Shannon & Wilson submitted a draft water and vapor samplingwork plan. Staff provided comments and identified a list of monitor wells that the department wanted sampled. Sampling activities began on November 7th. for

Don Fritz

10/27/2005

Update or Other Action

Shannon & Wilson was requested to provide a work plan for modifying the existing NTP for soil vapor extraction (SVE) treatment activities at the Sterling ZipMart site to include the installation and operation of a direct venting SVE system. Project staff believe that the direct discharge of vapors will be able to safely remove significant amounts of gasoline product, and should help the thermal oxidizer in removing and treating additional vapors.

Don Fritz

10/31/2005

Update or Other Action

An "Agreement to Mediated Terms and Release of Funds" document was signed by the Attorney General's office and all other parties covered under the agreement pertaining to the Sterling ZipMart insurance settlement with Zurich American Insurance Company. The Department of Law subsequently received a cashier's check for $720,349.73, representing the department’s cost recovery proceeds from the negotiated agreement to distribute the insurance proceeds from the Zurich settlement.

Don Fritz

1/23/2006

Update or Other Action

A funding request was elevated to allow for the installation of 4 additional downgradient monitor wells at the Sterling ZipMart site. The new wells are needed due to contamination migrating beyond the existing downgradient monitor wells.

Don Fritz

1/30/2006

Underground Storage Tank Site Characterization or Assessment

ADEC received a Shannon & Wilson report titled Water and Vapor Sampling, Sterling ZipMart. The report depicts that the dissolved phase contaminant plume has migrated beyond monitor wells 45 and 46. These monitor wells were the furthest downgradient monitor wells, and the last set of monitor wells between the plume and other potential downgradient receptors, including the Anderson residence and Suzie's Restaurant. Additional monitor wells will be recommended for installation.

Don Fritz

2/7/2006

Update or Other Action

Drinking water well sample results were received for wells at the Hubbard residence, the Anderson residence, Suzie's Restaurant, the Baptist Church, and the Alaska Wedding Brokers. The well at the Marlowe residence was not sampled due to the Marlowe's being out of town. No petroleum contamination was encountered in any of the well samples.

Don Fritz

2/10/2006

Underground Storage Tank Site Characterization or Assessment

A work plan for the installation of additional monitor wells downgradient of monitor wells MW-45 and MW-46 was received from Shannon & Wilson.

Don Fritz

2/27/2006

Update or Other Action

Project Manager changed from Don Fritz to Dave Pikul. File hand delivered to Anchorage by Paul Horwath.

Alyce Hughey

2/28/2006

Underground Storage Tank Site Characterization or Assessment

Repairs were made to a natural gas leak and fire-eye purge line was installed to aid in keeping the system operational during cold temperatures. The VES was restarted. The heat trace from the product recovery lines (no longer in use) was removed and installed on the vapor recovery lines in orfer to eliminate ice build-up in the lines from freezing condesate.

David Pikul

3/16/2006

Underground Storage Tank Site Characterization or Assessment

DEC requested that the term contractor provide services to complete data input and mapping efforts using GIS software for the site. All soil and groundwater data available will be input for creation of Shape files and finalized into a Geodatabase.

David Pikul

4/6/2006

Underground Storage Tank Site Characterization or Assessment

A Kenai Penninsula Borough Right-Of-Way permit was obtained for the installation of groundwater monitoring well points.

David Pikul

4/10/2006

Underground Storage Tank Site Characterization or Assessment

Permission has been obtained from ADOT&PF Maintenance Superintendent for the Kenai Penninsula for the installation of groundwater monitoring points in the Sterling Highway Right-Of-Way.

David Pikul

4/20/2006

Underground Storage Tank Site Characterization or Assessment

Five well points were installed along Lee Street and water samples collected for laboratory analysis.

David Pikul

4/25/2006

Underground Storage Tank Site Characterization or Assessment

DEC received proposal for the scope modification that will consist of collection of data to evaluate natural attenuation potential at the site.

David Pikul

4/26/2006

Underground Storage Tank Site Characterization or Assessment

Implementation of the groundwater sampling and collection of natural attenuation parameters monitoring tasks. In addition to obtaining depth to water and product thickness information, analytical samples will be collected from Monitoring Wells MW29, MW30, MW31, MW44, MW45, MW46, and MW47. The samples will be analyzed for GRO and BTEX. Natural attenuation parameters will be collected from all the monitoring wells except for the wells that have free-phase product. Field parameters to be collected will include: dissolved oxygen, nitrate, sulfate, ferrous iron, pH, temperature, ReDox, and conductivity. A low flow sampling pump will be used to facilitate sample collection.

Linda Nuechterlein

5/4/2006

Underground Storage Tank Site Characterization or Assessment

Received results of the water samples collected from the direct push well points. Four of the five well point samples contained detectable benzene concentrations. Benzene concentration in one of the four benzene containing samples exceeds the cleanup level. The highest benzene level was detected in the well point near the Sterling Highway and Lee Street intersection.

David Pikul

5/8/2006

Underground Storage Tank Site Characterization or Assessment

DEC requested term contractor provide services to decommission MW-31 nested groundwater monitoring wells at the site.

David Pikul

5/10/2006

Underground Storage Tank Site Characterization or Assessment

DEC received the proposal for the decommissioning of monitoring wells MW-31 and MW-10.

David Pikul

5/16/2006

Underground Storage Tank Site Characterization or Assessment

MW-10 and MW-31 were decommissioned.

David Pikul

5/24/2006

Underground Storage Tank Site Characterization or Assessment

A flame rod was installed on the thermal oxidizer burner

David Pikul

5/26/2006

Underground Storage Tank Site Characterization or Assessment

Eleven monitoring wells were sampled for natural attenuation parameters, GRO, and BTEX between 5/24 and 5/26. Utility locates were made along Barbara and Lee Streets. Six locations were staked for new monitoring wells.

David Pikul

5/29/2006

Underground Storage Tank Site Characterization or Assessment

DEC received the Spring 2006 Groundwater Monitoring Report and the Spring VES Monitoring & Pilot Study Report.

David Pikul

6/3/2006

Underground Storage Tank Site Characterization or Assessment

Six new groundwater monitoring wells (MW-54 - MW-59) were installed on 5/30 and 5/31. Three wells each are located along Lee Street and Barbara Street on the block south of the Sterling Highway. The 10-foot 0.01-inch slot screens were placed to span the water table and have around six feet of water column. The wells have above-ground completions, and are located off the roadway, but within the Borough right-of-way. The six new wells were developed on 6/1, and sampled for GRO, BTEX, and natural attenuation parameters on 6/2.

David Pikul

6/12/2006

Underground Storage Tank Site Characterization or Assessment

A vapor extraction pilot test was run on each of Monitoring Wells MW37, 43, 42, 8, 40, 7, and 6 (in chronological order) last week. Laboratory results from the eleven wells sampled along the "high concentration front" were received last week.

David Pikul

6/19/2006

Underground Storage Tank Site Characterization or Assessment

Groundwater laboratory data received for new wells MW-54 through MW-59. Data indicates that leading edge of the plume is at Barbara Street.

David Pikul

6/28/2006

Update or Other Action

Drinking water sampling report received from Shannon & Wilson with this date.Sampling events occurred on 1/18/2006 & 4/5/2006. 6 residence were sampled; Baptist, Wedding, Suzies, Anderson, Hubbard, & Marlowe. Contaminates were not detected in any of the sampling events.

Grant Lidren

6/30/2006

Update or Other Action

Spring 2006 Groundwater Investigation with this date submitted by Shannon & Wilson and received by DEC 7/05/2006. The report contains groundwater elevations and product thickness, plume delineation, groundwater charcterization and monitoring well maintenance. Front of plume with contaminats above ADEC clean up levels is between Lee Street and Barbara Street-2 samples in well MW-56 were above ADEC cleanup levels . Increase in contaminat levels found on Western edge of wetland. Three monitoring wells were decomissioned and several repaired.

Linda Nuechterlein

6/30/2006

Update or Other Action

Spring 2006 Vapor Extraction System Monitoring And Pilot Study with this date submitted by Shannon & Wilson and received by the DEC 7/05/2006. Remediation effforts and the vapor extraction system have removed 16,790 gallons of gasoline to date.

Linda Nuechterlein

7/5/2006

Underground Storage Tank Site Characterization or Assessment

DEC received the GIS deliverable.

David Pikul

8/3/2006

Underground Storage Tank Site Characterization or Assessment

NTP 1890281429 has been issued to Shannon & Wilson for continued operation and maintenance of the VES

Linda Nuechterlein

8/7/2006

Underground Storage Tank Site Characterization or Assessment

The two VES blowers were activated on 8/4/06.

Linda Nuechterlein

9/21/2006

Document, Report, or Work plan Review - other

A review of the Spring 2006 GW and 2006 Soil Vapor Extraction System (SVES) operation reports for the Sterling – ZipMart site has been completed. The Soil Vapor Extraction System (SVES) continues to operate and vapor concentrations collected during system operation indicate good vapor recovery opportunity. Following system operation during the later portion of the summer, the vapor concentrations have been reduced below 10,000 ppm, allowing for better quantification of recovered vapor. Monitoring of ambient air benzene concentrations indicates acceptable human exposure. Funding has been approved and a Notice To Proceed (NTP) issued to Shannon & Wilson for the installation of a second SVES shed and operation/maintenance of both the current and new SVE systems. A Request For Proposal (RFP) has been issued to the term contractor soliciting a proposal to decommission/repair selected site monitoring wells (MWs), and to sample both MWs and DW wells during a spring monitoring event

Linda Nuechterlein

9/25/2006

Update or Other Action

A Water Quality Monitoring and Soil Vapor Extraction System Operation Work Plan dated September 21, 2006 was approved. The project purpose is to conduct groundwater, drinking water, and surface water sampling; and to evaluate the effectiveness of the on-site Soil Vapor Extraction System (SVES).

Linda Nuechterlein

10/30/2006

Leaking Underground Storage Tank Corrective Action Underway

A work plan for the Sterling ZipMart site for continued operation of the existing Soil Vapor Extraction System (SVES) and installation of a new SVES to the east of the existing system was approved. The project purpose is to continue operation and maintenance of the existing SVES and develop a plan to allow treatment and cleanup of the secondary source area in order to reduce further migration of the contaminant plume.

Linda Nuechterlein

1/27/2007

Document, Report, or Work plan Review - other

Fall 2006 GW, SW & SVE Monitoring Report dated 12/7/06 by S&W was reviewed by ADEC. Lab data checkliist from S&W was included with this report. ADEC staff reviewed lab data and filled-out a checklist which was placed in the file. CSM was also completed and placed in the file.

Linda Nuechterlein

3/1/2007

Update or Other Action

CS completed review of the Groundwater Monitoring Program Work Plan, Former Sterling Zip Mart, 38525 Swanson River Road, Sterling, Alaska, ADEC Spill NO: 95-23-00-285-01; UST Facility ID NO: 2924 dated December 28, 2006 prepared by Shannon & Wilson. Included in the review is the revised TABLE 1 - WELL MONITORING PROGRAM submitted by e-mail on February 20, 2007 (attached). Approval letter issued to S&W for the work plan and amended table 1. Several of the wells listed in the monitoring plan will be assessed during the April 2007 monitoring event. Based on the findings of the April 2007 event, modifications may be made to the plan for the Fall 2007 and spring 2008 as noted in Table 1.

Linda Nuechterlein

3/12/2007

Exposure Tracking Model Ranking

Initial ranking completed.

Linda Nuechterlein

4/18/2007

Update or Other Action

The Spring 2007 groundwater sampling at Sterling Zipmart was completed on April 18. The Soil Vapor Extraction (SVE) system was most recently monitored on April 18 and May 14, 2007. The existing soil vapor extraction system (SVES) is currently being upgraded and expanded to allow for installation of a SVE shed and associated system components to the east of the existing SVES on the Sterling Baptist Church property. The existing SVES continues to extract vapors from the primary source area however, this expansion to the east would allow for treatment and cleanup of the secondary source area on the Sterling Baptist Church property.

Linda Nuechterlein

5/15/2007

Update or Other Action

The existing soil vapor extraction system (SVES) is currently being upgraded and expanded to allow for installation of a SVE shed and associated system components to the east of the existing SVES on the Sterling Baptist Church property. The existing SVES continues to extract vapors from the primary source area however, this expansion to the east would allow for treatment and cleanup of the secondary source area on the Sterling Baptist Church property. On May 15, 16, and 17 our state term contractor, Shannon & Wilson, worked with B.C. Excavating and Toklat Electric to install underground lines from Monitoring Wells MW7 and MW40 to the west blower shed, which was moved to the Sterling Baptist Church (SBC) property. The ground was found to be frozen 6 to 8 inches below the surface, making trench excavation difficult, and the quality of the backfill poor. Fence installation will be completed after Homer Electric provides service to Blower 2.

Linda Nuechterlein

7/5/2007

Update or Other Action

GIS based map dated 6/29/2007 submitted by Shannon & Wilson. Analytical results from Fall 2006 and Spring 2007 are incorporated in existing GIS-based map

Linda Nuechterlein

9/4/2007

Update or Other Action

Spring 2007 soil vapor extraction (SVE) system monitoring and modification report submitted by Shannon & Wilson on this date. Through the winter the SVE system removed an estimated 750 gallons of gasoline.

Linda Nuechterlein

9/11/2007

Update or Other Action

Received Spring 2007 Monitoring report dated August 30, 2007. QA/QC was completed by the consultant. Lab checklists which were completed by ADEC are stapled in the back of this report. Groundwater samples were collected from 27 monitoring wells. In addition MW60 was installed along the southern edge of the Sterling Highway. Report conclusions indicate 2007 measurments of the FP plume, found the least amount of measurable free product to date. Although operation of the remediation system and natural attenuation continue to reduce contaminant concentrations in the source area, there was an increase in benzene and GRO concentrations on the edge of the plume. The Kenai River is approximately 3/4 mile from the leading edge of the plume and is not in danger of being impacted by the contamination.

Linda Nuechterlein

10/12/2007

Update or Other Action

Groundwate Monitoring and Soil Vapor Extraction System(SVES) Operation Work Plan submitted by Shannon & Wilson.

Linda Nuechterlein

11/19/2008

Site Visit

On this date, a site visit was conducted by the ADEC project manager (PM) with the CSP term contractor (Shannon & Wilson) present. The Soil Vapor Extraction (SVE) system was monitored by the term contractor/S&W which included the following activities: a general inspection for damage and safety hazards; field measurements of vapor concentrations, analytical sampling and performing any necessary maintenance. Various scenarios for placement of ORC wells were considered and injection point locations discussed. The ADEC PM and the term contractor also canvassed the site and surrounding area to ascertain whether any new drinking water wells had been installed that could be potentially impacted by the hydrocarbon plume.

Linda Nuechterlein

4/27/2009

Update or Other Action

The Spring 2009 groundwater monitoring round was completed between Tuesday, April 21 and Saturday, April 25, 2009 by the ADEC term contractor. Water/product levels were measured on April 21, and floating product was not encountered. A few of the planned wells were not measured due to surface ponds or ice. Samples were collected from 21 monitoring wells, including the new nested Wells MW61S & MW61D at the ORC pilot study site. Samples were collected from three drinking water systems. The water was off at Suzie’s Café and the ZipMart building. The SVE system was monitored and sampled on April 20 by the CSP term contractor, and various adjustments, maintenance, and field screening were performed on April 25, 26, and 27.

Linda Nuechterlein

5/1/2009

Update or Other Action

It was reported by the CSP term contractor on this date that installations of 20 Oxygen Release Compound (ORC) injection wells and one nested monitoring well (MW) were completed between April 20 and Thursday April 23, 2009. Eighty pounds of ORC Advanced were injected into the 20 wells on Friday, April 24 and Monday April 27. In general the work proceeded smoothly.

Linda Nuechterlein

10/14/2009

Document, Report, or Work plan Review - other

ADEC reviewed & approved a work plan dated October 8, 2009 for monitoring of groundwater(GW) & drinking water wells (DW); as well as continued monitoring & operation of the soil vapor extraction system (SVES). Updates to the fiscal year (FY) 2010 GW monitoring program were summarized in Table 1 which identifies GW monitoring wells & DW wells to be monitored, sampled, repaired, and decommissioned, as well as the frequency of monitoring proposed for FY 2010. An approval letter was sent to S&W on this date.

Linda Nuechterlein

10/22/2009

Document, Report, or Work plan Review - other

Reviewed & approved the report documenting Spring 2009 groundwater monitoring (GW), drinking water (DW) sampling, and soil vapor extraction system (SVES) operation monitoring; as well as the injection of oxygen release compound (ORC) to enhance natural attenuation in groundwater at the plume front. This is the first monitoring round where measureable LNAPL (light nonaqueous phase liquid) was not confirmed in any of the Free Product Zone wells tested. Results of natural attenuation testing support previously observed trends and suggest that aerobic degradation is occurring around the edges and within the down-gradient portions of the contaminant plume. VOCs (volatile organic compounds) were not detected in samples taken from three DW systems. The SVES continued operation between October and April 2009. The concentrations of hydrocarbons measured in vapors removed from the subsurface have declined to the lowest levels measured since the SVES began operation. This along with the lack of measurable LNAPL in wells suggests that the SVES is reducing the mass of volatile hydrocarbons in the subsurface

Linda Nuechterlein

6/22/2010

Site Visit

Traveled to Soldotna to conduct a site visit at the Sterling Zipmart site and meet with the ADEC term contactor. Pilot tests are being conducted to evaluate treatment options to supplement the Soil Vapor Extraction (SVE) system in order to reduce the mass of gasoline contaminants available for transport down-gradient. Treatment technologies being considered include air sparging and in-situ air stripping/recirculation using existing recovery wells. Both technologies add oxygen to the groundwater to enhance biological degradation, and move volatile contaminants from the dissolved phase to the vapor phase

Linda Nuechterlein

8/4/2010

Update or Other Action

Reviewed the Spring 2010 Monitoring & Remediation Report, which documents Spring 2010 groundwater monitoring, drinking water (DW) sampling; remediation system pilot study results and recommendations; continued operation and monitoring of the soil vapor extraction system (SVES); and further characterization of the northeastern (NE) plume area. Recent sampling results indicate that benzene is moving through a greater thickness of the aquifer in the NE plume area than was indicated by previous testing results in 2005. The results also suggest that the aquifer formation and distribution of contaminants are stratified. Installation and sampling of additional nested monitor wells completed at different depths will be included in the next SOA Request for Proposal.

Linda Nuechterlein

8/12/2010

Update or Other Action

A Request for Proposal (RFP) for the Former Sterling ZipMart to include the following activities: (1) design and installation of Air Sparge (AS) and Soil Vapor Extraction (SVE) wells and/or modifications to the existing SVE system; (2) continued operation, maintenance and monitoring of the remediation system; (3) monitoring of water quality by sampling groundwater and drinking water wells; (4) focused feasibility study to evaluate viable treatment options for the contaminated plume front; (5) further characterize soil and groundwater in the northeast plume front, and (6) removal of contaminated source area on the Zipmart Property was sent out on Aug. 12th. Since contamination at this “State Lead” site is a result of leaks from an underground storage tank (UST) system subject to 18 AAC 78 regulations, cleanup is eligible under American Recovery and Reconstruction Act (ARRA) funding. The deadline for all work to be completed under ARRA is September 30, 2011.

Linda Nuechterlein

12/3/2010

Update or Other Action

Drilling of air injection and vapor extraction wells; remediation system trenching; and installation of monitoring wells (east of Swanson River Road) have now been completed at the Sterling Zipmart site. The newly installed soil vapor extraction (SVE) wells are now operational; however, the air sparge blowers are on still on backorder. In addition, three down-gradient monitoring wells (MW71N, MW72N, MW73N) were completed and sampled. This work is being funded by American Recovery and Reinvestment Act (ARRA) funds which are due to expire in September 2011.

Linda Nuechterlein

12/29/2010

Update or Other Action

On December 29, 2010 the remediation system at the Sterling Zipmart site was monitored by the CSP term contractor, Shannon and Wilson (S&W). S&W reported that the four blowers were running, and a temporary fence is now in place around the remediation sheds on the Zipmart property. No problems with the air injection system were noted. The Soil Vapor Extraction (SVE) vapor screening results again show that the new north system (Blower 2) is pulling in most of the hydrocarbons. Groundwater dissolved oxygen was also measured in five monitoring wells. This work is being funded by American Recovery and Reinvestment Act (ARRA) funds which are due to expire in September 2011.

Linda Nuechterlein

2/24/2011

Update or Other Action

Installation of the expanded remediation system at the Sterling Zipmart to include air injection wells, was completed by end of December 2010. Since the start of 2011, the CSP term contractor, Shannon & Wilson has made three site visits to the Sterling Zipmart and reported that the remediation system is running steadily. On each of the site visits dissolved oxygen (DO) was measured in three new nested monitoring wells in addition to other select wells, to evaluate the effectiveness of the remediation system. Lab results from the most recent Fall 2010 groundwater sampling event indicate the plume front is still expanding with benzene increasing in several monitoring wells located along the leading edge of the plume. It is anticipated that the Fall Monitoring report will be completed and submitted to DEC soon. Data from this report will assist in evaluating the viability of treatment options for the plume front.

Linda Nuechterlein

4/11/2011

Update or Other Action

Results from recent groundwater sampling indicates that groundwater adjacent to property located at 34684 Sterling Highway Ware Residence) may be impacted by the Sterling Zipmart plume. On March 15, 2011 a letter was sent to notify the current owner and resident that groundwater on her property may have been impacted by hydrocarbon contamination based on recent sampling results from adjacent property. On April 11, 2011 the CSP term contractor sampled the DW wells at this residence.

Linda Nuechterlein

4/28/2011

Update or Other Action

Spring 2011 Well Monitoring Program for the Sterling ZipMart project which is summarized in “Table 1 – Spring 2011 Well Monitoring Program" was reviewed and approved by DEC. The Spring monitoring event is scheduled to begin on May 2, 2011. DEC staff will conduct a site visit during that week.

Linda Nuechterlein

5/4/2011

Site Visit

Site visit by ADEC staff to inspect Spring Monitoring Event in progress this week.

Linda Nuechterlein

9/1/2011

Site Visit

Conduct a site inspection during intallation of ORC Lines A - C which is being funded with ARRA grant.

Linda Nuechterlein

10/24/2011

Document, Report, or Work plan Review - other

Wells identified in Table 1- FY2012 are approved for sampling under the Fall 2011 groundwater monitoring program.

Linda Nuechterlein

11/18/2011

Document, Report, or Work plan Review - other

Fiscal Year 2012 Operations Plan, and Spring 2011 Monitoring Report are approved.

Linda Nuechterlein

3/1/2012

Update or Other Action

Fall 2011 Zipmart groundwater monitoring report was approved.

Linda Nuechterlein

4/26/2012

Update or Other Action

On this date approval for the Zipmart Spring 2012 groundwater sampling program was sent to S&W. EDB will be sampled in the B&D Auto and Ware Residence drinking water wells, as well as MW 71D.

Linda Nuechterlein

6/14/2012

Site Visit

CS project manager conducted site visit on this date.

Linda Nuechterlein

8/10/2012

Update or Other Action

Funding was approved to monitor water quality of groundwater and drinking water wells; operate, maintain and monitor the Soil Vapor Extraction (SVE); and Air Sparge (AS) remediation system ; and cover costs associated with obtaining components needed to expand the air sparging (AS) remediation system .

Linda Nuechterlein

9/6/2012

Update or Other Action

Starting on September 6th a Pilot Test was initiated to determine the feasibility of In-Situ Chemical Oxidation at the Sterling-Zipmart site.

Linda Nuechterlein

10/1/2012

Update or Other Action

Received Draft Zipmart Spring 2012 Monitoring report from CSP term contractor (Shannon & Wilson) for agency review on Oct. 1st. This comprehensive report includes groudnwater monitoring of ~ 100 wells; drinking water well sampling; remediation system operation and monitoring; installation of additional monitorng wells; and investigation of a sink hole.

Linda Nuechterlein

10/25/2012

Update or Other Action

Completed review of the Draft Zipmart Spring 2012 Monitoring report including lab review checklists. Provided written comments/edits to the term contractor (S&W) and followed-up with a phone call to discuss on this date.

Linda Nuechterlein

11/2/2012

Update or Other Action

“Table 1 – Fiscal Year 2013 Well Monitoring Program” for Sterling Zipmart is approved. The term contractor plans to begin the fall sampling round on Tuesday, November 6, 2012.

Linda Nuechterlein

11/27/2012

Update or Other Action

Zipmart Spring 2012 Monitoring Report (received Oct. 2012) was approved. This report represents remediation and groundwater monitoring conducted between Dec. 2011 and May 2012.

Linda Nuechterlein

12/14/2012

Update or Other Action

As of this date, the remediation system upgraded with 14 new air sparge wells. Also one new nested monitoring well pair have been installed, the compressor shed placed and wired in, and a temporary fence around the shed.

Linda Nuechterlein

4/18/2013

Document, Report, or Work plan Review - other

Reviewed and approved FY 13 Spring Monitoring work plan.

Linda Nuechterlein

6/5/2013

Document, Report, or Work plan Review - other

Spring 2013 Additional Services Work Plan dated May 2013 approved. The planned work includes pumping and treating contaminated water from the shallow perched aquifer at the source area to further reduce contaminant mass; installing a remote monitoring system to improve remediation system efficiency; and decommissioning out-of-use monitoring wells.

Linda Nuechterlein

6/20/2013

Document, Report, or Work plan Review - other

Zipmart Fall 2012 Monitoring and Remediation Report dated March 2013 is approved. Lab review checklists included with this report were also reviewed and approved.

Linda Nuechterlein

6/24/2013

Update or Other Action

Funding approved for continued operation of remediation systems. NTP issued to term contractor.

Linda Nuechterlein

6/25/2013

Document, Report, or Work plan Review - other

Decommissioning of various monitor wells including MW32, MW34, MW35, MW38, MW39, RW11, and WP-2 approved by DEC.

Linda Nuechterlein

9/20/2013

Document, Report, or Work plan Review - other

Spring 2013 Monitoring and Remediation report for Sterling Zipmart approved by DEC. Lab review checklists included with this report were also reviewed and approved.

Linda Nuechterlein

10/22/2013

Document, Report, or Work plan Review - other

Revisions to Table 1, for Fall 2013 Well Monitoring Plan are approved.

Linda Nuechterlein

4/17/2014

Document, Report, or Work plan Review - other

Revised Report for 2013 Fall Monitoring is received by ADEC on this day. The report includes groundwater monitoring & remediation work conducted between June - November 2013. The project scope included GW monitoring; O&M of remediation systems; installing and operating a pump and treat system; installation of a remote monitoring system; and MW decommissioning. Revisions requested by ADEC have been made and report is approved.

Linda Nuechterlein

4/21/2014

Update or Other Action

Groundwater monitoring included the biannual water level measurement and sampling event conducted April 21 - April 23, 2014.

Linda Nuechterlein

4/24/2014

Update or Other Action

The Pump and Treat System (P&T) system that was operated during the summer of 2013 to remove contaminant mass from the perched aquifer at the source area, was re-started for operation during Summer 2014.

Linda Nuechterlein

5/30/2014

Update or Other Action

The term contractor inspected the site on Friday 5/30 and the following was reported to DEC. The P&T system is operational; inflow and tank samples were collected. The North and East AS systems were running fine. The hydrocarbon concentrations in the SVE exhaust continue to decrease slowly. Suzie's Cafe (downgradient of the plume) is now open, and a water sample was collected from their drinking water well.

Linda Nuechterlein

8/5/2014

Site Visit

CSP staff conducted a site inspection and met with the Contaminated Sites Program (CSP) term contractor (Shannon and Wilson) who was conducting monitoring and maintenance activities.

Linda Nuechterlein

10/27/2014

Document, Report, or Work plan Review - other

Groundwater monitoring plan proposed in Table 1 - Fall 2014 Monitoring Program is approved with the condition to add MW68S to the sampling plan.

Linda Nuechterlein

1/13/2015

Document, Report, or Work plan Review - other

Draft Biannual Monitoring and Remediation Report (received Nov. 21, 2014) is approved. The report presents the results of Shannon & Wilson's remediation & groundwater (GW) monitoring work conducted between Nov. 2013 and June 2014 at the former Sterling Zipmart site. The project scope included GW monitoring, drinking water sampling, modification of the eastern air injection system (EAIS), and operation and maintenance of the active remediation systems.

Linda Nuechterlein

4/23/2015

Update or Other Action

Zipmart groundwater monitoring program for Spring 2015 was approved on this date. See "Table 1- Spring 2015 Well Monitoring Program" for sampling details.

Linda Nuechterlein

6/24/2015

Site Visit

Site visit to observe ORC injections, SVE, sprage, and pump and treat systems.

Joshua Barsis

11/4/2015

Document, Report, or Work plan Review - other

Reviewed the Fiscal Year 2015 Monitoring and Remediation Report, dated October 2015 (all activities were performed between July 2014 and June 2015). Activities described in the report mainly consisted of groundwater monitoring, drinking water well sampling, operation and monitoring of the active remediation systems (air-sparge, soil-vapor extraction, and pump and treat), and an oxygen releasing compound (ORC) application feasibility study. The objective of the ORC feasibility study was to determine if applying ORC to the subsurface would be effective in enhancing bio-attenuation and reducing contaminant mass in the perched aquifer on the ZipMart property. 1,160 pounds of ORC was poured into 29 soil borings that were advanced to 13 feet below ground surface. Monitoring Well MW3b was installed down-gradient of the ORC application for the purpose of monitoring attenuation where ORC was injected. Initial sample results from MW3b were 466 mg/L GRO, 89 mg/L benzene, 123 mg/L toluene, 5.33 mg/L ethylbenzene, and 26.8 mg/L xylenes.

Joshua Barsis

7/6/2016

Document, Report, or Work plan Review - other

Reviewed the Fiscal Year 2016 Monitoring and Remediation Report, dated June 2016 (all activities were performed between July 2015 and June 2016). Activities described in the report mainly consisted of groundwater monitoring, drinking water well sampling, operation and monitoring of the active remediation systems (air-sparge, soil-vapor extraction, and pump and treat), and associated well and systems maintenance. Next report should be received July or August 2017.

Joshua Barsis

2/16/2018

Document, Report, or Work plan Review - other

Reviewed the Fiscal Year 2017 Monitoring and Remediation Report, dated November 2017 (all activities were performed between July 2016 and June 2017). Activities described in the report mainly consisted of groundwater monitoring, drinking water well sampling, operation and monitoring of the active remediation systems (air-sparge, soil-vapor extraction, and pump and treat), and associated well and systems maintenance. Next report should be received November 2018.

Joshua Barsis

7/5/2018

Document, Report, or Work plan Review - other

Reviewed the Fiscal Year 2018 Monitoring and Remediation Report, dated June 2018. Activities described in the report mainly consisted of groundwater monitoring, drinking water well sampling, operation and monitoring of the active remediation systems (air-sparge, soil-vapor extraction, and pump and treat), and associated well and systems maintenance.

Joshua Barsis

7/8/2019

Document, Report, or Work plan Review - other

Reviewed the Fiscal Year 2019 Monitoring and Remediation Report, dated June 2019. Activities described in the report mainly consisted of groundwater monitoring, drinking water well sampling, operation and monitoring of the active remediation systems (air-sparge, soil-vapor extraction, and pump and treat), and associated well and systems maintenance.

Joshua Barsis

7/1/2020

Site Characterization Report Approved

The department received the Fiscal Year 2020 Monitoring and Remediation Sterling ZipMart report. The report detailed maintenance of the wells, the soil vapor extraction and air sparging systems, and use of the pump and treat system. In May 2020, drinking water wells at the Sterling Baptist Church, Bennett residence, and Moose River Dental were collected. None of the target anayltes were detected. Groundwater monitoring occurred in Fall 2019 and Spring 2020, alternating groups of wells. Groundwater flow direction was east-southeast (as previously observed). During the alternate sampling events, plume front wells (MW65S, MW66S, MW66M, MW77S, and MW77D) were sampled. Nested pair MW66S and MW66M benzene concentrations continue to be stable since 2014. MW65S has continued to decrease since 2017, while MW65D has been increasing during the same time. During sampling events plume boundary wells (MW8, MW33, MW52, MW56, MW56D, MW25S, MW25D, MW44D, MW68D, and RW17) were sampled. Benzene in MW25S, MW56D, MW56, and MW52 (south boundary wells) appears to be trending downward since 2014. Benzene in wells MW23D, MW33, MW40, MW71S, MW72S have decreased since 2013 after the initiation of the east air sparge system. PVC casings for wells MW2, MW25S, and MW25D were cut down in 2020.

Lisa Krebs-Barsis

11/1/2021

Site Characterization Report Approved

The department received the Fiscal Year 2021 Monitoring and Remediation Sterling ZipMart report. The report detailed sampling and maintenance of the wells, the soil vapor extraction and air sparging systems, and use of the pump and treat system. In May 2021, drinking water samples at the Sterling Baptist Church, the Ware, Marlow, and Hubbard residences, and the B&D Auto Repair were collected. Target petroleum constituents were not detected. Groundwater monitoring occurred in Fall 2020 and Spring 2021, alternating groups of wells. Groundwater flow direction was east-southeast (as previously observed).

Lisa Krebs-Barsis

12/7/2021

Meeting or Teleconference Held

Meeting with supervisor for handoff notes. Fiscal Year 2020 Monitoring and Remediation Sterling ZipMart, 38525 Swanson River Road Sterling, Alaska dated, July 2020 and Fiscal Year 2021 Monitoring and Remediation Sterling ZipMart, 38525 Swanson River Road Sterling, Alaska, dated November 2021 reports are being reviewed by supervisor and actions will be updated once complete.

Jessica Hall

2/1/2024

Document, Report, or Work plan Review - other

Report approved for remediation and maintenance activities from July 2021 to December 2023. During this period, the remediation systems were maintained and significant repairs were made following the collapse of the structure which severed power to some of the systems. A new power pole was installed in the KPB right-of-way and the systems were brought back online.

Lisa Krebs-Barsis

Contaminant Information

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2021-2023 Monitoring and Remediation Report

2018.06.29 S&W Sterling ZipMart FY 2018 Report

Settlement Agreement

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Alaska Department of Environmental Conservation

Site Report: ZipMart Store - Sterling

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2021-2023 Monitoring and Remediation Report

2018.06.29 S&W Sterling ZipMart FY 2018 Report

Settlement Agreement

Missing Location Data

State of Alaska Department of Environmental Conservation