Skip to content Skip to content

Alaska Department of Environmental Conservation

You are here: DEC / SPAR / CSP / SPAR Online Services / Contaminated Sites Search / Site Report

Site Report: Chevron - Wasilla

Site Name: Chevron - Wasilla
Address: Mi. 43 Parks Hwy.; , 601 West Parks Highway, Wasilla, AK 99687
File Number: 2265.26.003
Hazard ID: 23280
Status: Cleanup Complete - Institutional Controls
Staff: IC Unit, 9074655229 dec.icunit@alaska.gov
Latitude: 61.581980
Longitude: -149.467600
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.

Problems/Comments

The Wasilla Chevron Store is located on Lot 13B, Block 3, Snider Subdivision, Wasilla Alaska. In 1990, an initial environmental site assessment was conducted in order to assess the nature and extent of onsite contamination. During the initial site assessment, soil and groundwater were found to be adversely impacted by gasoline constituents. As a result of this assessment, a cleanup strategy was created and implemented. The cleanup strategy included three phases: The removal of five underground storage tanks (USTs), associated piping and dispensers (Phase I), treatment and disposal of contaminated soil (Phase II), and implementation of a groundwater treatment program (Phase III). The groundwater treatment program included the installation of an Air sparge/soil vapor extraction system (AS/SVE), and the onsite monitoring of groundwater contaminant levels. In 1993, the five formerly operational USTs, product piping, and nine dispensers were removed; additionally, three new USTs were installed. The new USTs are double walled steel tanks that conform to state and federal regulations. During the excavation of the old USTs, 350-cubic yards of gasoline impacted soil was excavated and stockpiled on site. Shortly after this, AS/SVE piping system was expanded to treat the contaminated soil stockpile. Since 1993, over 20 monitoring wells have been repeatedly sampled and analyzed for gasoline constituents. To date, groundwater contaminant concentrations do not exceed state regulatory levels on site; however, offsite groundwater, specifically in the center of the parks highway continues to be adversely impacted. This site continues to receive cleanup grant funds through the state’s financial assistance program.

Action Information

Action Date Action Description DEC Staff
12/20/1990 Site Added to Database Former Staff
12/20/1990 Leaking Underground Storage Tank Release Confirmed - Petroleum LUST Site created in CSP for source area ID 76133 ADD; Waiting for site assessment and sample results. Working with RP Former Staff
12/21/1990 Leaking Underground Storage Tank Cleanup Initiated - Petroleum LCAU; :LCAU Date changed DB conversion Former Staff
12/21/1990 Underground Storage Tank Site Characterization or Assessment SA1R; :Action Date changed DB conversion 1/11/11 Former Staff
12/21/1990 Leaking Underground Storage Tank Corrective Action Underway LCAR; :Action Date changed DB conversion 1/11/11 Former Staff
12/22/1990 Release Investigation RELR; :Action Date changed DB conversion 1/11/11 Former Staff
1/28/1991 Release Investigation SI; Site Assessment was submitted. Former Staff
1/31/1991 Update or Other Action NOR; Notice of release letter sent to property owner. Former Staff
2/25/1991 Update or Other Action REM; Conclusions reached from report & meeting: potential for contamination minimal & immediate soils excavation/remediation not warranted. However additional site investigation is needed. Former Staff
12/14/1992 Leaking Underground Storage Tank Corrective Action Underway CAPR; Groundwater monitoring report review and plan review for source investigation. Former Staff
2/3/1993 Update or Other Action CAPR; Groundwater monitoring report and contaminant source evaluation. Former Staff
3/23/1993 Update or Other Action CAPR; Monitoring report for groundwater and vapor extraction/air sparging remediation system update of operation. Former Staff
9/7/1993 Site Visit FI; Former Staff
9/8/1993 Site Visit FI; Former Staff
9/9/1993 Site Visit FI; Former Staff
9/10/1993 Site Visit FI; Former Staff
9/13/1993 Site Visit FI; Former Staff
9/15/1993 Site Visit FI; Former Staff
9/17/1993 Site Visit FI; Former Staff
10/8/1993 Update or Other Action CAPR; Groundwater contaminant levels decreasing but still excessive contamination remains. UST's and a substantial amount of contaminated soil have been removed. Former Staff
2/28/1994 Leaking Underground Storage Tank Corrective Action Underway LCAR; RP notified that additional corrective action is needed. Former Staff
5/19/1994 Leaking Underground Storage Tank Corrective Action Underway LCAR; Reviewed most recent info and requested expansion of the on-site air sparging system. Former Staff
8/18/1994 Long Term Monitoring Established MS; Contaminant levels in the groundwater have decreased. Expansion of the air sparging system may not be warranted. Former Staff
1/27/1995 Release Investigation RELR; Release Investigation Review. MW #9 is non-detectable. MWs #8 & 10 are significantly increasing. Expansion of the air sparging/vapor extraction system a likelihood. Former Staff
4/17/1995 Leaking Underground Storage Tank Corrective Action Underway CAPR; Reviewed supplemental plan information. Contaminant levels in well G-10 have not decreased over time despite air sparging/vapor extraction efforts. Additionally, oxygen levels in well G-3 have been non-detectable. Without sufficient oxygen, the treatment system cannot perform adequately. The plan consists of installing an additional 3 sparging wells and 2 vapor extraction wells. The air sparging pump is to be upgraded to provide sufficient air volumes and pressures for the existing and proposed wells. The plan is approved because it meets Departmental concerns. Former Staff
8/8/1995 Release Investigation RELR; Reviewed ground water monitoring information. Former Staff
10/11/1995 Update or Other Action CAPR; Reviewed a Ground Water Monitoring Report and a Soil Remediation Plan. Former Staff
12/1/1995 Update or Other Action CAPR; Reviewed a FY'96 Continuation Cleanup Grant Workplan. No clear pattern of decreasing contamination has been seen in recent monitoring reports. The department requires sampling on a quarterly basis except wells #6 and #13, which need only to be sampled annually. Former Staff
1/9/1996 Leaking Underground Storage Tank Corrective Action Underway CAPA; Reviewed a FY'96 Continuation Cleanup Grant Work Amended Plan. Approved the GW and Air monitoring plans. Former Staff
1/25/1996 Update or Other Action UPD; Reviewed a soil treatment cell sampling report, a summary of sampling results. Please submit recalcualtion information converting analyses from EPA method 8100m to AK 102 method. Also need a an estimated volume for each soil pile. Soil pile 1 appears to be ready for disposal. Pile 2 needs further treatment. Former Staff
5/1/1996 Update or Other Action UPD; Reviewed a quarterly ground water sampling report. Former Staff
7/17/1996 Update or Other Action UPD; Reviewed a stockpile sampling report. The department will consider stockpile #1 to meet cleanup levels. The soil may be disposed of, provided that it is landspread a min. of 100' from a private well, 200' from public wells, and 100' from any sensitive environments. Stockpile #2 does not meet cleanup levels and more treatment is needed. The department approves the plan to add nutrients, oxidizers and additional aeration. Former Staff
9/11/1996 Update or Other Action UPD; Reviewed a Stockpile Treatment Plan. The potential to place the stockpile #2 contaminated soils into a road base for a road paving project did not occur. Therefore, the submitted plan will likeky go forward. Three items in the proposed landspreading plan need to be addressed: access, seasonal factors, and liner. Former Staff
3/3/1997 Leaking Underground Storage Tank Corrective Action Underway CAPA; Reviewed a FY97, Continuation Cleanup Grant Work Plan. Former Staff
11/20/1997 Update or Other Action ADEC sends Notification of Intent to Cost Recover Letter to Current Owner: G. B. WEBER Former Staff
11/16/1998 Update or Other Action Received 'Well Search Report' from Gilfilian. John Carnahan
6/29/2000 Long Term Monitoring Established 6/00 approved FAP WKPlan for Screening Risk Assessment for Closure. Former Staff
1/9/2001 Update or Other Action Review of 2001 FAP WP by JBC. Comments provided to Consultant on this day for comment, prior to submittal to FAP. John Carnahan
5/8/2001 Site Visit JBC - In May, went to site to observe a RI that consisted of numerous wells installed in the median and offsite. John Carnahan
8/6/2001 Underground Storage Tank Site Characterization or Assessment JBC - review of RI that identified substantial heavy-end compounds in roadway, extending to other side of hwy. Recommend that GW monitoring be conducted to evaluate stability, and review the effectiveness of remediation system. John Carnahan
8/5/2002 Underground Storage Tank Site Characterization or Assessment Additional GW assessment report submitted to DEC. John Carnahan
1/15/2003 Document, Report, or Work plan Review - other Review 'Summary Report and Request for NFRAP' dated 12/5/03. Comments not provided as of this date. Communication with consultant as to proposed actions for FY04 in progress. John Carnahan
2/17/2003 Update or Other Action Submit comments on NFRAP request and FY04 workplan to consultant. Recommend additional monitoring activities and LTM requirements. John Carnahan
7/23/2003 Update or Other Action Changed file number from L55.366 Anc to 2265.26.003 Wendy Uzzell
12/9/2003 Underground Storage Tank Site Characterization or Assessment September 2003 Monitoring Event and Well Decommissioning Report submitted to ADEC. Deborah Williams
1/28/2004 Update or Other Action Transferred DEC staff lead from John Carnahan Cynthia Pring-Ham
3/19/2004 Institutional Control Record Established The institutional controls for the site included the following: A deed notice is filed at the Palmer Recording District regarding contaminant concentrations at the site for both the soil and groundwater that exceed ADEC cleanup levels. A notice will also be entered into the ADEC’s Leaking Underground Storage Tanks (LUST) Database. In accordance with 18 AAC 75.325(i), ADEC approval will be obtained prior to removal and/or disposal of soil or groundwater from this site to an off-site location. The installation of water supply wells and/or dewatering activities at this site is prohibited without prior approval of the ADEC. A groundwater monitoring plan, that includes the annual groundwater sampling of monitoring wells G-23, G-24, and G-16, shall be developed and approved by ADEC. The groundwater samples shall be analyzed for GRO, DRO, and BTEX. The monitoring plan shall remain in effect until the established groundwater cleanup levels are achieved. The floor drain, located in the building, must by inventoried with the Environmental Protection Agency (EPA) and closed in accordance with EPA requirements for the Underground Injection Control program. Deborah Williams
5/10/2004 Document, Report, or Work plan Review - other ADEC received the 2004 Monitoring Event Report for Wasilla Chevron. Deborah Williams
12/16/2004 Conditional Closure Approved A conditional closure letter was issued to Gary Weber. Deborah Williams
12/16/2004 Long Term Monitoring Established Annual groundwater sampling is required for G-23, G-24, and G-16. The samples should be analyzed for GRO, DRO, and BTEX. Deborah Williams
9/6/2005 Update or Other Action Received a change in mailing address information for Gary Weber who passed away on April 22, 2005. The new mailing address for his estate is GBW Inc., 12350 Industry Way, #216, Anchorage, AK 99515. Deborah Williams
12/5/2005 Document, Report, or Work plan Review - other ADEC reviewed Wasilla Chevron's 2005 Monitoring Event Report. Groundwater samples were collected from G-16, G-23 and G-24. Benzene, GRO and DRO were detected above ADEC cleanup levels in G-23. Benzene was also detected above the cleanup levels in G-24. Petroleum hydrocarbons were not detected above cleanup levels in G-16. MWH concluded that the contaminant levels in G-23 indicate a trend slowly reducing contaminant levels. Contaminant levels in G-24 remain relatively stable with only benzene above the cleanup level. G-16 had detectable levels of DRO, GRO, and benzene, ethylbenzene, and xylenes. MWH attributes these detections because this sampling had historically high groundwater levels in the well which may have mobilized hydrocarbons from areas that were above the groundwater interface during previous sampling events. Deborah Williams
8/29/2012 Update or Other Action Staff changed from Rich Sundet to IC Unit. Kristin Thompson
9/25/2012 Institutional Control Compliance Review IC compliance review conducted and reminder system was intialized to follow up with the RP regarding groundwater monitoring. Evonne Reese
6/23/2015 Institutional Control Update An IC reminder letter was issued to the new property owner on this date. Kristin Thompson
7/8/2015 Institutional Control Update ADEC was contacted by a consultant on behalf of the responsible party. It appears plans are in place to conduct the required groundwater monitoring and evaluation of the floor drain. ADEC plans to follow-up in early fall of this year. Kristin Thompson
8/7/2015 Institutional Control Update Rescon Alaska is the consultant hired by the current landowner to complete the groundwater sampling and close out the floor drain. Monitoring should be done in September. The reminder system has been updated with this info so that we follow up about the report in about six months time. Evonne Reese
11/30/2015 Document, Report, or Work plan Review - other Received a copy of a closure plan report for a Class V injection well under the Underground Injection Control Program. The plan report was address to the EPA Groundwater Unit. Evonne Reese
12/1/2015 Document, Report, or Work plan Review - other Received approval from the EPA Office of Compliance and Enforcement on the closure plan for the waste disposal well at this site. Evonne Reese
12/10/2015 Institutional Control Update Received a groundwater monitoring report. We will update the site record once the report has been reviewed. Evonne Reese
12/16/2015 Document, Report, or Work plan Review - other ADEC reviewed the Long Term Monitoring Report for Wasilla Chevron, submitted by Rescon Alaska and dated December 4, 2015. Groundwater samples were collected on September 15, 2015 from monitoring wells G-23 and G-24 for DRO, GRO, and BTEX analysis. Monitoring well G-16 was discovered damaged and could not be sampled due to the presence of sloughed in soil inside the well casing. Concentrations of benzene were above ADEC cleanup levels in both monitoring wells. Concentrations of DRO and GRO were also above cleanup levels in monitoring well G-23. The next groundwater monitoring event should occur in fall 2016. The report also mentioned their EPA approved plan for closure of the floor drain is scheduled to occur in January/February 2016. Kristin Thompson
8/12/2016 Institutional Control Update The consultant is waiting to receive EPA's approval before closing out the floor drain. Reminder system set to follow-up in six months. Kristin Thompson
3/20/2017 Document, Report, or Work plan Review - other ADEC reviewed the 2016 Annual Monitoring Report for Wasilla Chevron, submitted by Rescon Alaska and dated March 9, 2017. During the 2015 monitoring effort, monitoring well G16 was discovered damaged with soil sloughing in the casing that created a blockage and prevented samples from being taken. In May 2016, well G16 was inspected and found the casing to be intact, soil blockage gone, and groundwater present in the well. The well monument and concrete base were replaced to protect the casing from further disturbance. On September 8, 2016, groundwater samples were collected from monitoring wells G16, G23 and G24 for DRO, GRO, and BTEX analysis. Concentrations of benzene were above ADEC cleanup levels in wells G23 (0.0098 mg/l) and G24 (0.00714 mg/l). Concentrations of ethylbenzene were also above cleanup levels in wells G23 (0.0847 mg/l) and G24 (0.0603 mg/l). Concentrations of total xylenes exceeded ADEC cleanup levels in wells G16 (0.47 mg/l) and G23 (0.299 mg/l). Concentrations of DRO and GRO were either non-detect or below ADEC cleanup levels in all wells. The exceedance of ethylbenzene and xylenes concentrations are due to the revision of their respective cleanup levels (per ADEC Regulation 18 AAC 75, updated November 2016) as opposed to any marked increase in contaminants in the wells; based on historical results, contaminants in the wells continue to exhibit declining concentrations. The next groundwater monitoring event should occur in fall 2017. Kristin Thompson
3/20/2017 Institutional Control Compliance Review IC compliance review conducted. Reminder system set to follow-up on IC compliance every five years. Kristin Thompson
7/26/2017 Institutional Control Update Received a closure letter issued by EPA regarding the floor drain. The letter also acknowledges that the drain was misidentified by EPA as an underground injection well rather than a floor drain. Evonne Reese
5/15/2018 Document, Report, or Work plan Review - other ADEC reviewed the 2017 Annual Monitoring Report for Wasilla Chevron, submitted by Rescon Alaska. Monitoring activities were conducted in accordance with ADEC Guidance on October 11, 2017. Groundwater samples were collected from three monitoring wells (G16, G23, G24) and sampled for GRO, DRO, and BTEX. Concentrations of benzene were above ADEC cleanup levels in wells G23 (0.0101 mg/l) and G24 (0.00487 mg/l). Concentrations of ethylbenzene were also above cleanup levels in wells G23 (0.0847 mg/l) and G24 (0.172 mg/l). Concentrations of DRO and GRO were detected below ADEC cleanup levels in G23 and G24. Xylenes were below the revised 2017 ADEC cleanup levels for all wells this sampling event. Kristin Thompson
5/16/2018 Institutional Control Compliance Review IC compliance review conducted. Closure/IC Details updated. Concentrations are still above cleanup levels for some contaminants in some wells, but they've demonstrated a decreasing trend over the years. Rescon recommended decreased monitoring frequency and ADEC approved their request by letter. Groundwater monitoring frequency has been reduced from annually to every other year. The next groundwater monitoring event is planned for 2019 and every odd year thereafter. Reminder system set for follow-ups. Kristin Thompson
10/21/2020 Institutional Control Compliance Review Received the 2020 groundwater monitoring report on this date. This report will be reviewed in the near future and this record will be updated with the report details. All other IC requirements are in compliance at this site. Evonne Reese
10/22/2020 Document, Report, or Work plan Review - other Reviewed the 2019 Groundwater Monitoring Results. Groundwater samples were collected from monitoring wells G-16, G-23 and G-24 for analysis of petroleum hydrocarbons. The groundwater monitoring results indicate that the offsite groundwater petroleum contaminants have been reduced to levels below Table C cleanup levels. The concentrations at each of the wells have continued to exhibit steady declines over time. To confirm the decrease one additional groundwater monitoring effort will be completed in 2021. If contaminant concentrations are again below Table C cleanup levels in 2021, DEC will consider a discontinuation of the groundwater monitoring program. Evonne Reese
11/29/2022 Long Term Monitoring Workplan or Report Review Reviewed the 2021 Groundwater Monitoring Results. Groundwater samples were collected from monitoring wells G-16, G-23 and G-24 for analysis of petroleum hydrocarbons. The groundwater monitoring results confirmed that the offsite groundwater petroleum contaminants have remained below Table C cleanup levels therefore future groundwater monitoring requirements are rescinded. This will be documented in a DEC letter to the landowner in the near future. Evonne Reese
11/30/2022 Institutional Control Compliance Review IC compliance review conducted and a letter was issued to the property owner regarding the discontinuation of the long term groundwater monitoring. The next review will be in five years' time. Evonne Reese

Contaminant Information

Name Level Description Media Comments
Benzene > Human Health/Ingestion/Inhalation Soil
GRO > Human Health/Ingestion/Inhalation Soil
DRO > Human Health/Ingestion/Inhalation Soil
Benzene > Table C Groundwater
Ethylbenzene > Table C Groundwater
GRO > Table C Groundwater
DRO > Table C Groundwater

Control Type

Type Details
Notice of Environmental Contamination A Notice of Environmental Contamination was recorded at the Recording Dist. 311 - Palmer on 3/19/2004. The record number is 2004-007082-0. 20 pages.

Requirements

Description Details
Advance approval required to transport soil or groundwater off-site. Standard condition.
Groundwater Use Restrictions The installation of water supply wells and/or dewatering activities at this site is prohibited without prior approval of the ADEC.
Movement or use of contaminated material (including on site) in a manner that results in a violation of the water quality standards is prohibited (18 AAC 70) Standard condition.
Periodic Review The ADEC will perform periodic compliance reviews every five years.
Other By end of year 2023.

No associated sites were found.

Missing Location Data

Because the GIS location data for this site has not been entered, we cannot direct you to its position on the map. Click "Continue" to proceed to the Contaminated Sites Web Map or "Close" to return to the site report.
Continue     Close

Public Notices  •  Regulations  •  Statutes
Press Releases  •  Contact

 

State of Alaska Department of Environmental Conservation

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