Site Report: Wildwood AFS Disposal Trenches

Site Name:	Wildwood AFS Disposal Trenches
Address:	3.5 Mile North Kenai Road, Wildwood Drive, Kenai, AK 99611
File Number:	2320.38.051
Hazard ID:	25196
Status:	Active
Staff:	Erica Blake, 9074512182 erica.blake@alaska.gov
Latitude:	60.609878
Longitude:	-151.298674
Horizontal Datum:	WGS84

We make every effort to ensure the data presented here is accurate based on the best available information currently on file with DEC. It is therefore subject to change as new information becomes available. We recommend contacting the assigned project staff prior to making decisions based on this information.

Site Chronology
IC / Closure Details
Documents
Associated Sites

Problems/Comments

This source area consists of nine former disposal trenches. The trenches are varied in length. Records detailing the type of debris disposed of in the trenches have not been identified. However, tires, metal scraps, wood, and rusty 55-gallon drums were identified in some trenches during the RI. Based on results of groundwater sampling at the perimeter of the trench area, general water quality of the shallow aquifer has not been degraded down-gradient of the trenches. Based on available information, soil at the trenches (excluding the burn pit area) does not exceed cleanup targets. The trenches have been capped.

Action Information

Action Date	Action	Description	DEC Staff
4/7/1990	Update or Other Action	Phase II HTRW report completed. Several areas found to be contaminated with petroleum or other hazardous substances. Several different source areas of concern were identified within the larger site. The landfill area was investigated, a well point was installed and sampled, a geophysical survey indicated about 16,000 square feet of landfill area (excluding the trenches). A pond is adjacent to the landfill. 60-80 drums, some leaking unidentified wastes was identified ~ 150' north of well point #1.	John Halverson
4/7/1990	Site Added to Database	Multiple contaminants. (Date adjusted from 11/10/1999 for report/query consistency. (Reese))	John Halverson
2/3/1992	Update or Other Action	OHM conducted a removal action for the Corps and submitted a summary report. It indicated that ~ 26 drums of waste were removed from the general area of the disposal trenches.	John Halverson
1/25/1995	Site Characterization Report Approved	Received the draft-final Phase III Remedial Investigation Report - Cleanup Design, prepared by E&E, for the Corps. It documented low levels of vinyl chloride in groundwater beneath the landfill and solid waste on the ground surface in the landfill and trench disposal areas.	John Halverson
8/22/1995	Long Term Monitoring Established	Received groundwater monitoring plan documents from the Corps calling for quarterly and semi-annual monitoring from various wells throughout the Wildwood AFS site.	John Halverson
8/22/1995	Update or Other Action	Received the final baseline human health risk assessment report for Wildwood AFS. It concluded that an unacceptable risk may exist under current or potential future land uses at the landfill area along with some other areas at the larger site.	John Halverson
4/1/1996	Risk Assessment Report Approved	Received the final Ecological Risk Assessment Report (Tier I) for Wildwood AFS. It recommended either proceeding to a Tier II ecological risk assessment or conducting removal/remedial actions to address hot spots.	John Halverson
4/18/1996	Proposed Plan	The Corps finalized the proposed plan. Preferred alternatives included: Main Complex tank farm and USTs 5-1 and 5-2 - vapor extraction and air sparging; Maintenance Building, ACS MARS, Quonset Hut and Disposal Trench Area Burn Pit - soil excavation and off-site treatment followed by no further action; Operations Building - excavation and off-site treatment followed by natural attenuation and institutional controls; Landfill and Disposal Trenches - capping, natural attenuation (landfill area only) and institutional controls.	John Halverson
6/3/1996	Update or Other Action	Received a groundwater monitoring report for tank farm area from sampling in August 1995. It covered the main complex area tank farm and USTs (significant fuel contamination), ACS/MARS facility (low level DRO), Operations Building (DRO and low TEX), Landfill (low level VOCs) and Trench disposal areas (DRO and benzene at burn pit area).	John Halverson
7/20/1996	Update or Other Action	ADEC received a draft record of decision for the Wildwood Air Force Station FUDS. It called for capping the landfill and disposal trench areas with soil, grading and revegetating the areas and monitoring groundwater. It also called for documenting the disposal site locations in the appropriate land records as an institutional control. Due to challenges over implementing institutional controls and a few other issues, the ROD has not been finalized.	John Halverson
8/27/1996	Update or Other Action	Received the December 1995 groundwater monitoring event report. It covers the tank farm area and former USTs at the main complex (significant petroleum contamination in GW at and downgradient from tank farm), the ACS MARS facility and Quonset Hut area (low level DRO in GW), the Operation Building (DRO and TEX in GW), Landfill (low level VOCs) and Trench Disposal Areas (DRO, benzene at burn pit area).	John Halverson
11/22/1996	Interim Removal Action Approved	Received final "Remedial Action Report Interim Removal Action, Wildwood AFS" by Harding and Lawson Associates, October 28, 1996. Conclusions, based on confirmation samples at the end of the removal document that within the Trench Area Burn Pit elevated DRO (1,200 - 18,000 mg/kg) remains in soil.	John Halverson
8/13/1997	Update or Other Action	ADEC received the workplan for Phase II Remediation, Wildwood AFS, by HLA/Wilder, dated July 2, 1997. Plan called for capping the disposal trenches and landfill areas with a soil cover and revegetating them. ADEC reviewed and commented on the draft workplan, but the comments were not all addressed. No formal approval was given on the plan.	John Halverson
12/9/1997	Update or Other Action	Received the groundwater monitoring report for sampling done in July 1997. Groundwater levels have dropped significantly, some MWs have gone dry. Sampling was done at the tank farm and former USTs at the main complex (sheen and noticeable fuel odor present in two MWs, free product in MW AP-365; also 1,2 DCA level increased in a downgradient, off-site MW), Landfill (low level VOCs), Operations Building (up to 6 mg/l DRO), Rifle range (260 ug/l total lead) and Firing Range (12 ug/l total lead).	John Halverson
5/15/1999	Update or Other Action	Received groundwater monitoring report for sampling done in July 1998. Tank farm area (GW level rose slightly, free product found in 3 MWs, GRO increasing in down-gradient MW, 1,2DCA increasing in downgradient MW), Landfill area (low level VOCs, near cleanup levels), Operations building (DRO low levels, need new wells in better locations), Rifle range (total lead and antimony decreased, dissolved lead and antimony N/D), Firing range (total and dissolved lead and antimony N/D).	John Halverson
9/3/1999	Update or Other Action	ADEC received the Remedial Action Report, Phase II Remediation, by HLA/Wilder, dated August 25, 1999. It documents work done between June 1997 and November 1998. The landfill and trench areas were capped as specified in the workplan. Trench area burn pit still has residual soil contamination that needs to be addressed, either through institutional controls or further cleanup.	John Halverson
9/12/2002	Site Number Identifier Changed	Workplan changed from X5 to x9. Sequence Number changed to 03 from 01 to accommodate changing the Workplan. The DBA pointed out to the project manager that despite this site being listed as a military landfill, vinyl chloride appears to be the biggest chemical of concern.	John Halverson
9/12/2002	Site Ranked Using the AHRM	Checked the Multiple Sources box.	Former Staff
2/3/2005	Update or Other Action	File number issued 2320.38.051	Aggie Blandford
6/21/2005	Meeting or Teleconference Held	Staff visited all of the Wildwood sites with the new project manager and the environmental engineer for the site. Staff also observed the ROST/LIF in operation.	Debra Caillouet
6/15/2007	Update or Other Action	The Declaration of Project Closure Decison for the CON/HTRW project at Wildwood was signed.	Debra Caillouet
9/22/2008	Site Added to Database	A new site has been added to the database	Mitzi Read
9/26/2008	Exposure Tracking Model Ranking	Initial ranking with ETM completed for source area id: 78510 name: Disposal Trenches	Debra Caillouet
11/16/2009	Site Characterization Workplan Approved	Final Work Plan, Soil Assessment and Groundwater Monitoring of Non-Tank Farm Sites, Former Wildwood Air Force Station, Kenai, November 2009 will sample soil and groundwater at the site.	Debra Caillouet
6/4/2010	Document, Report, or Work plan Review - other	2009 Report Soil Assessment and Groundwater Monitoring of Non-Tank Farm Sites Former Wildwood Air Force Station, FUDS The results of the chemical analyses were compared to Table B2 the ADEC 18 AAC 75.341, Oil and Hazardous Substances Pollution Control. In addition, the measured concentrations of dioxin-related compounds were adjusted using toxicity equivalence factors (TEFs; WHO, 2005) to account for differing degrees of toxicity, then summed for a toxicity equivalent (TEQ) relative to the concentration of one of the most toxic dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). TEQ concentrations were then compared to the 2,3,7,8-TCDD ADEC cleanup level. Lead, PCBs, and TEQ dioxin results are summarized in Figure 6-1. Complete analytical results (Table B8), TEF-adjusted dioxin concentrations (Table B9), and a soil sample tracking table (Table B2) are presented in Appendix B. Soil sample results are summarized below: • Lead was detected in all soil samples at concentrations two orders of magnitude less than the most stringent ADEC soil cleanup level (residential land use; 400 mg/kg). • PCBs were not detected in any soil samples at the Burn Pit site. • TEQ dioxin concentrations were two to five orders of magnitude below the ADEC cleanup level (58 nanograms per kilogram (ng/kg)).	Debra Caillouet
8/26/2015	Update or Other Action	This file has been partially archived at Alaska Archives Barcode 896958, 896959	Susan Carberry
3/12/2019	Update or Other Action	Site history letter sent on this day. Recommended for closure. See file for letter.	Joshua Barsis
7/9/2024	Site Visit	DEC staff conducted a site visit to the Wildwood AFS area in Kenai, Alaska. The purpose of the site visit was to inspect multiple sites within the Wildwood Air Force Station and observe groundwater monitoring fieldwork. Sites inspected were; 12-acre Landfill, disposal trench area, Underground Storage Tank (UST) area near the Correctional Facility, and the Operations Maintenance Building. U.S. Army Corp of Engineers staff accompanied DEC staff around the facility for the inspection.	Peter Campbell
7/29/2024	Update or Other Action	DEC provided the U.S. Army Corp of Engineers with a letter summarizing site inspection notes from a July 9, 2024 site visit at various Wildwood AFS sites. The letter described several deviations from the approved work plans (dated 2016 and 2023), and requested USACE discuss impacts of the deviations and issues in the reporting.	Erica Blake

Action Date

Action

Description

DEC Staff

4/7/1990

Update or Other Action

Phase II HTRW report completed. Several areas found to be contaminated with petroleum or other hazardous substances. Several different source areas of concern were identified within the larger site. The landfill area was investigated, a well point was installed and sampled, a geophysical survey indicated about 16,000 square feet of landfill area (excluding the trenches). A pond is adjacent to the landfill. 60-80 drums, some leaking unidentified wastes was identified ~ 150' north of well point #1.

John Halverson

4/7/1990

Site Added to Database

Multiple contaminants. (Date adjusted from 11/10/1999 for report/query consistency. (Reese))

John Halverson

2/3/1992

Update or Other Action

OHM conducted a removal action for the Corps and submitted a summary report. It indicated that ~ 26 drums of waste were removed from the general area of the disposal trenches.

John Halverson

1/25/1995

Site Characterization Report Approved

Received the draft-final Phase III Remedial Investigation Report - Cleanup Design, prepared by E&E, for the Corps. It documented low levels of vinyl chloride in groundwater beneath the landfill and solid waste on the ground surface in the landfill and trench disposal areas.

John Halverson

8/22/1995

Long Term Monitoring Established

Received groundwater monitoring plan documents from the Corps calling for quarterly and semi-annual monitoring from various wells throughout the Wildwood AFS site.

John Halverson

8/22/1995

Update or Other Action

Received the final baseline human health risk assessment report for Wildwood AFS. It concluded that an unacceptable risk may exist under current or potential future land uses at the landfill area along with some other areas at the larger site.

John Halverson

4/1/1996

Risk Assessment Report Approved

Received the final Ecological Risk Assessment Report (Tier I) for Wildwood AFS. It recommended either proceeding to a Tier II ecological risk assessment or conducting removal/remedial actions to address hot spots.

John Halverson

4/18/1996

Proposed Plan

The Corps finalized the proposed plan. Preferred alternatives included: Main Complex tank farm and USTs 5-1 and 5-2 - vapor extraction and air sparging; Maintenance Building, ACS MARS, Quonset Hut and Disposal Trench Area Burn Pit - soil excavation and off-site treatment followed by no further action; Operations Building - excavation and off-site treatment followed by natural attenuation and institutional controls; Landfill and Disposal Trenches - capping, natural attenuation (landfill area only) and institutional controls.

John Halverson

6/3/1996

Update or Other Action

Received a groundwater monitoring report for tank farm area from sampling in August 1995. It covered the main complex area tank farm and USTs (significant fuel contamination), ACS/MARS facility (low level DRO), Operations Building (DRO and low TEX), Landfill (low level VOCs) and Trench disposal areas (DRO and benzene at burn pit area).

John Halverson

7/20/1996

Update or Other Action

ADEC received a draft record of decision for the Wildwood Air Force Station FUDS. It called for capping the landfill and disposal trench areas with soil, grading and revegetating the areas and monitoring groundwater. It also called for documenting the disposal site locations in the appropriate land records as an institutional control. Due to challenges over implementing institutional controls and a few other issues, the ROD has not been finalized.

John Halverson

8/27/1996

Update or Other Action

Received the December 1995 groundwater monitoring event report. It covers the tank farm area and former USTs at the main complex (significant petroleum contamination in GW at and downgradient from tank farm), the ACS MARS facility and Quonset Hut area (low level DRO in GW), the Operation Building (DRO and TEX in GW), Landfill (low level VOCs) and Trench Disposal Areas (DRO, benzene at burn pit area).

John Halverson

11/22/1996

Interim Removal Action Approved

Received final "Remedial Action Report Interim Removal Action, Wildwood AFS" by Harding and Lawson Associates, October 28, 1996. Conclusions, based on confirmation samples at the end of the removal document that within the Trench Area Burn Pit elevated DRO (1,200 - 18,000 mg/kg) remains in soil.

John Halverson

8/13/1997

Update or Other Action

ADEC received the workplan for Phase II Remediation, Wildwood AFS, by HLA/Wilder, dated July 2, 1997. Plan called for capping the disposal trenches and landfill areas with a soil cover and revegetating them. ADEC reviewed and commented on the draft workplan, but the comments were not all addressed. No formal approval was given on the plan.

John Halverson

12/9/1997

Update or Other Action

Received the groundwater monitoring report for sampling done in July 1997. Groundwater levels have dropped significantly, some MWs have gone dry. Sampling was done at the tank farm and former USTs at the main complex (sheen and noticeable fuel odor present in two MWs, free product in MW AP-365; also 1,2 DCA level increased in a downgradient, off-site MW), Landfill (low level VOCs), Operations Building (up to 6 mg/l DRO), Rifle range (260 ug/l total lead) and Firing Range (12 ug/l total lead).

John Halverson

5/15/1999

Update or Other Action

Received groundwater monitoring report for sampling done in July 1998. Tank farm area (GW level rose slightly, free product found in 3 MWs, GRO increasing in down-gradient MW, 1,2DCA increasing in downgradient MW), Landfill area (low level VOCs, near cleanup levels), Operations building (DRO low levels, need new wells in better locations), Rifle range (total lead and antimony decreased, dissolved lead and antimony N/D), Firing range (total and dissolved lead and antimony N/D).

John Halverson

9/3/1999

Update or Other Action

ADEC received the Remedial Action Report, Phase II Remediation, by HLA/Wilder, dated August 25, 1999. It documents work done between June 1997 and November 1998. The landfill and trench areas were capped as specified in the workplan. Trench area burn pit still has residual soil contamination that needs to be addressed, either through institutional controls or further cleanup.

John Halverson

9/12/2002

Site Number Identifier Changed

Workplan changed from X5 to x9. Sequence Number changed to 03 from 01 to accommodate changing the Workplan. The DBA pointed out to the project manager that despite this site being listed as a military landfill, vinyl chloride appears to be the biggest chemical of concern.

John Halverson

9/12/2002

Site Ranked Using the AHRM

Checked the Multiple Sources box.

Former Staff

2/3/2005

Update or Other Action

File number issued 2320.38.051

Aggie Blandford

6/21/2005

Meeting or Teleconference Held

Staff visited all of the Wildwood sites with the new project manager and the environmental engineer for the site. Staff also observed the ROST/LIF in operation.

Debra Caillouet

6/15/2007

Update or Other Action

The Declaration of Project Closure Decison for the CON/HTRW project at Wildwood was signed.

Debra Caillouet

9/22/2008

Site Added to Database

A new site has been added to the database

Mitzi Read

9/26/2008

Exposure Tracking Model Ranking

Initial ranking with ETM completed for source area id: 78510 name: Disposal Trenches

Debra Caillouet

11/16/2009

Site Characterization Workplan Approved

Final Work Plan, Soil Assessment and Groundwater Monitoring of Non-Tank Farm Sites, Former Wildwood Air Force Station, Kenai, November 2009 will sample soil and groundwater at the site.

Debra Caillouet

6/4/2010

Document, Report, or Work plan Review - other

2009 Report Soil Assessment and Groundwater Monitoring of Non-Tank Farm Sites Former Wildwood Air Force Station, FUDS The results of the chemical analyses were compared to Table B2 the ADEC 18 AAC 75.341, Oil and Hazardous Substances Pollution Control. In addition, the measured concentrations of dioxin-related compounds were adjusted using toxicity equivalence factors (TEFs; WHO, 2005) to account for differing degrees of toxicity, then summed for a toxicity equivalent (TEQ) relative to the concentration of one of the most toxic dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). TEQ concentrations were then compared to the 2,3,7,8-TCDD ADEC cleanup level. Lead, PCBs, and TEQ dioxin results are summarized in Figure 6-1. Complete analytical results (Table B8), TEF-adjusted dioxin concentrations (Table B9), and a soil sample tracking table (Table B2) are presented in Appendix B. Soil sample results are summarized below: • Lead was detected in all soil samples at concentrations two orders of magnitude less than the most stringent ADEC soil cleanup level (residential land use; 400 mg/kg). • PCBs were not detected in any soil samples at the Burn Pit site. • TEQ dioxin concentrations were two to five orders of magnitude below the ADEC cleanup level (58 nanograms per kilogram (ng/kg)).

Debra Caillouet

8/26/2015

Update or Other Action

This file has been partially archived at Alaska Archives Barcode 896958, 896959

Susan Carberry

3/12/2019

Update or Other Action

Site history letter sent on this day. Recommended for closure. See file for letter.

Joshua Barsis

7/9/2024

Site Visit

DEC staff conducted a site visit to the Wildwood AFS area in Kenai, Alaska. The purpose of the site visit was to inspect multiple sites within the Wildwood Air Force Station and observe groundwater monitoring fieldwork. Sites inspected were; 12-acre Landfill, disposal trench area, Underground Storage Tank (UST) area near the Correctional Facility, and the Operations Maintenance Building. U.S. Army Corp of Engineers staff accompanied DEC staff around the facility for the inspection.

Peter Campbell

7/29/2024

Update or Other Action

DEC provided the U.S. Army Corp of Engineers with a letter summarizing site inspection notes from a July 9, 2024 site visit at various Wildwood AFS sites. The letter described several deviations from the approved work plans (dated 2016 and 2023), and requested USACE discuss impacts of the deviations and issues in the reporting.

Erica Blake

Contaminant Information

Name

Level Description

Media

Comments

Control Type

Type

Details

Requirements

Description

Details

There are no documents for this site report.

No associated sites were found.

Missing Location Data

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Alaska Department of Environmental Conservation

Site Report: Wildwood AFS Disposal Trenches

Site Chronology

IC / Closure Details

Documents

Associated Sites

Problems/Comments

Action Information

Contaminant Information

Control Type

Requirements

Missing Location Data

State of Alaska Department of Environmental Conservation