Site Report: FAA Coghlan Island
| Site Name: | FAA Coghlan Island |
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| Address: | Tongass Nat'l Forest, 11 miles NW of Juneau, Auke Bay, AK 99821 |
| File Number: | 1544.38.001 |
| Hazard ID: | 4176 |
| Status: | Active |
| Staff: | Jenny Gates, 9072628203 jenny.gates@alaska.gov |
| Latitude: | 58.359306 |
| Longitude: | -134.699143 |
| Horizontal Datum: | WGS84 |
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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
Coghlan Island is a small, uninhabited island in Stephens Passage near the entrance to Auke Bay. The former FAA Coghlan Island Station was established in the late 1950s at the northern end of the island. Past activities at the station included fuel storage and handling, generator operations, and on-site waste disposal. A 1992 investigation identified several areas of concern, including two former aboveground storage tanks associated with Buildings 417 and 621 and associated piping, as well as a burn pit (TX AOC3) and a separate burn barrel location (SAN AOC1). The former tanks and fuel lines were decommissioned in 1997, and roughly 100 cubic yards of petroleum-contaminated soil was excavated; however, confirmation sampling showed contamination remained in place, prompting additional investigations through 2012 to further define its extent. Residual contamination in soil is below the ingestion/human health cleanup levels. In 2015, DEC determined that groundwater beneath the site did not qualify as a current or future drinking water source and issued a 350 Determination. Additional cleanup occurred at the burn pit and burn barrel during two mobilizations in 2016. Confirmation samples were all below the applicable 18 AAC 75 ingestion cleanup levels.
Action Information
| Action Date | Action | Description | DEC Staff |
|---|---|---|---|
| 10/1/1990 | Update or Other Action | Entry backdated 3/9/2026: REPORT - COGHLAN ISLAND RECONNAISSANCE REPORT | Jamie McKellar |
| 9/1/1992 | Update or Other Action | Entry backdated 3/9/2026: REPORT - Environmental Compliance Investigation Report, Coghlan Island FAA Station, Coghlan Island, Alaska | Jamie McKellar |
| 8/18/1997 | Update or Other Action | Entry backdated 3/9/2026: REPORT - FAA Alaska Region - Site 40 - Coghlan Island Reconnaissance Report | Jamie McKellar |
| 11/26/1997 | Update or Other Action | Entry backdated 3/9/2026: REPORT - Aboveground Storage Tank (AST) Decommissioning Assessment, FAA Coghlan Island, Coghlan Island, Alaska | Jamie McKellar |
| 1/1/1998 | Update or Other Action | Entry backdated 3/9/2026: REPORT - Coghlan Island FAA Station Debris Site Investigation | Jamie McKellar |
| 3/24/1998 | Update or Other Action | Entry backdated 3/9/2026: REPORT - Final Site Cleanup and Investigation Report, Coghlan Island, Alaska | Jamie McKellar |
| 5/1/2000 | Update or Other Action | Entry backdated 3/9/2026: REPORT - Final Release Investigation Report, Federal Aviation Administration Coghlan Island Station | Jamie McKellar |
| 6/15/2012 | Site Characterization Workplan Approved | Approved the final work plan describing site characterization activities at two former above ground storage tanks and associated pipeline. Site activities include the installation of soil borings and monitoring wells. The FAA will use an ultra-violet optical screening tool/ laser induced fluorescence (UVOST/LIF) probe to investigate the horizontal and vertical extent of petroleum contamination at the site and to help determine the optimal locations for the monitoring wells. Soil and groundwater samples will be analyzed for gasoline, diesel, and residual range organics (GRO, DRO, and RRO); benzene, toluene, ethylbenzene, and xylenes (BTEX); and polynuclear aromatic hydrocarbons (PAHs). Additional data will be collected to use the Hydrocarbon Risk Calculator. | Melody Debenham |
| 6/3/2013 | Site Characterization Report Approved | Received final remedial action report describing release investigation activities at the Transmitter Building 417 former above ground storage tank (AST) 40-A-1 and the former pump house building 621 former AST 40-A-2. Soil sample results show petroleum contaminated soil remains at concentrations above the migration to groundwater cleanup level but below the ingestion/inhalation cleanup levels. Groundwater sample results show diesel range organics above the cleanup level in the groundwater. | Melody Debenham |
| 5/13/2014 | Update or Other Action | Approved work associated with replacement of engine generators at Building 417. Trenching will occur in an area of known petroleum contamination. Any contaminated soil encountered can be placed back into the excavation. | Melody Debenham |
| 3/4/2015 | 350 Determination | Groundwater use determination letter sent. DEC has determined that the groundwater at Coghlan Island does not meet the criteria to be considered a current or future drinking water source. DEC has further determined that contamination in the groundwater at this site will not be transported to either surface water or to a current or reasonably expected future source of drinking water. Following this determination, further groundwater monitoring at the Coghlan Island sites will not be required and the Migration to Groundwater soil cleanup levels are no longer requirements for the cleanup. | Fred Vreeman |
| 3/6/2015 | Update or Other Action | Entry backdated 3/6/2015: DEC Approved the Hydrocarbon Risk Calculator Report for two areas of concern, Building 417 /Transmitter Building Aboveground Storage Tank (AST) and Building 621/Former Pump House AST. The HRC indicates that site conditions meet human health risk standards, but groundwater contamination is present above the applicable cleanup levels for DRO. A 350 Determination was issued for groundwater on 3/4/2015. | Jamie McKellar |
| 4/12/2016 | Document, Report, or Work plan Review - other | Approved final work plan for the burn site located southeast of the Transmitter Building 417 (TX AOC3) and the former burn barrel located southwest of the burn site (SAN AOC1). Contaminated soil at these locations will be excavated and transported off-site for treatment. Field screening for lead will be performed using a Niton x-ray fluorescence analyzer. Excavation confirmation samples will be analyzed for lead, diesel range organics, residual range organics, and dioxins. | Melody Debenham |
| 9/27/2016 | Document, Report, or Work plan Review - other | Approved final report documenting removal and off-site treatment of lead and petroleum contaminated soil from two former burn areas. The confirmation sample results at the former Burn Pit (TX AOC3) and former Burn Barrel Area (SAN AOC1) were below the ingestion cleanup levels. | Melody Debenham |
| 5/2/2018 | Update or Other Action | Responsible party is waiting for FY18 funding to decommission the groundwater monitoring wells. | Danielle Duncan |
| 10/2/2018 | Document, Report, or Work plan Review - other | Work Plan Approved: Coghlan Island Monitoring Well Decommissioning (Brice, 2018). The purpose of the work plan is to decommission 10 groundwater monitoring wells. | Danielle Duncan |
Contaminant Information
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Control Type
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Requirements
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No associated sites were found.