Site Report: FAA McGrath Bldg 305
| Site Name: | FAA McGrath Bldg 305 |
|---|---|
| Address: | Airport, east of runway, McGrath, AK 99627 |
| File Number: | 2612.38.001 |
| Hazard ID: | 22916 |
| Status: | Active |
| Staff: | Sophia Bracio, 9074511682 sophia.bracio@alaska.gov |
| Latitude: | 62.956932 |
| Longitude: | -155.599989 |
| 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
Building 305 is the station maintenance shop building located adjacent to Building 604 (former utility building). The source area encompasses former tank locations at both Buildings 305 and 604. In 1993, three underground storage tanks (UST; UST 16-B-9, UST 16-B-10, and UST 16-B-14) were decommissioned and replaced by four new USTs (UST 16-B-109, UST 16-B-115, UST 16-B-110, and UST 16-B-114). During the 1993 decommissioning activities, hydrocarbon-contaminated soils were encountered. Approximately 270 cubic yards of contaminated soil was excavated from the location of UST 16-B-9; the Building 305 UST location; and the Building 605 heating oil tank location. A 1994 investigation identified impacted soil and groundwater surrounding the locations of the former USTs. In 1996, an in-situ bioventing system was installed at the Shop Building 305/Former Utility Building 604 site to address contamination. The system was operational until 2004. A second RI was conducted in 2011. A non-aqueous phase liquid (NAPL) contaminated soil source area was identified as extending from the Building 305 heating oil UST location to the Building 604 heating oil UST location (about 120 feet). The NAPL-contaminated soil extends from approximately seven to 20 feet bgs. The deepest contamination was found near the Building 305 heating oil tank. Soil samples were collected from Building 305/604 in 2011. Based on those results, DRO, ethylbenzene, xylene, naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene concentrations exceeded the 2016 ADEC Method 2 Migration to Groundwater cleanup levels. Groundwater monitoring was conducted at Building 305/604 in 2011, 2012, and 2013. All groundwater samples were analyzed for BTEX, GRO, DRO, and RRO. Additionally, groundwater samples from three of the source area wells were also analyzed for PAH, EPH, and VPH. In 2011 and 2012, one sample each exceeded the November 2016 Table C Groundwater cleanup levels for DRO and 1-methylnaphthalene. In 2011, 2012, and 2013, one sample exceeded the Table C groundwater cleanup levels for naphthalene.
Action Information
| Action Date | Action | Description | DEC Staff |
|---|---|---|---|
| 10/15/1993 | Site Added to Database | Former Staff | |
| 10/15/1993 | Leaking Underground Storage Tank Release Confirmed - Petroleum | LUST Site created in CSP for source area ID 75859 USTs were decommissioned and approximately 65 cubic yards of impacted soil was excavated. | Deborah Williams |
| 7/10/1995 | Release Investigation | Release investigation was conducted and 10 soil samples and two groundwater samples were collected from the area. The results of the RI indicated that approximately 400-500 cubic yards of soil contained EPH concentrations greater than ADEC cleanup levels and that benzene was detected in groundwater at concentrations greater than MCLs. | Deborah Williams |
| 7/15/1996 | Leaking Underground Storage Tank Corrective Action Underway | Bioventing system was installed and startup began on July 15, 1996. | Deborah Williams |
| 7/15/1996 | Leaking Underground Storage Tank Cleanup Initiated - Petroleum | Added by the Administrator. | Cynthia Pring-Ham |
| 8/15/2001 | Update or Other Action | A report was submitted that indicated approximately 1,300 pounds of petroleum hydrocarbons had been removed from the soil and benzene had not been detected in groundwater since August 1997. | Deborah Williams |
| 12/31/2003 | Update or Other Action | RECKEY has automatically been generated. | |
| 1/12/2010 | Exposure Tracking Model Ranking | Initial ranking with ETM completed for source area id: 75859 name: FAA - McGrath Bldg 305 | Melody Debenham |
| 8/2/2011 | Site Characterization Workplan Approved | Approved the Final Work Plan, Federal Aviation Administration (FAA) Release Investigation, FAA Station, McGrath, Alaska, describing investigation activities at 14 areas of concern at the FAA McGrath Station. An Ultra-Violet Optical Screening Tool (UVOST)/laser-induces fluorescence (LIF) probe will be used as a screening tool to investigate the horizontal and vertical extent of petroleum contamination. Locations of soil borings and groundwater monitoring wells will be determined based on site conditions and the UVOST/LIF screening results. | Melody Debenham |
| 5/16/2014 | Document, Report, or Work plan Review - other | Approved final 2013 groundwater monitoring report at 8 areas of concern. Results from Shop Building 305/Utility Building 604 are below cleanup levels. | Melody Debenham |
| 2/23/2015 | Document, Report, or Work plan Review - other | Approved final 2013 release investigation at 11 areas of concern. Sample results at the Shop Building 305/Former Utility Building 604 UST site shows contaminated soil and groundwater remain at this site. | Melody Debenham |
| 12/9/2016 | Update or Other Action | Teleconference with FAA project manager to discuss future actions at FAA McGrath sites. | Melody Debenham |
| 4/19/2017 | Document, Report, or Work plan Review - other | Letter sent to FAA advising that no response is required for the Department's December 2016 correspondence. Since multiple AOCs were evaluated using the HRC, ADEC will not be able to use the July 2016 report as a basis for decision making. ADEC will re-evaluate FAA McGrath AOCs that appear ready for closure. Some sites may be eligible for cleanup based on a cumulative risk evaluation. Other sites require additional investigation and/or remediation by FAA. | Jamie McKellar |
| 12/11/2017 | Exposure Tracking Model Ranking | A new updated ranking with ETM has been completed for source area 75859 FAA - McGrath Bldg 305. | Jamie McKellar |
| 7/25/2024 | Meeting or Teleconference Held | On 7/23/2024, DEC met with FAA and their contractor regarding planned soil sampling at FAA McGrath. FAA's contractor is mobilizing to McGrath in fall 2024 to collect soil and groundwater samples. The intent of the mobilization is to evaluate FAA's sites for the presence/absence of PFAS in future excavation areas that are currently slated for remediation via landfarming. | Jamie McKellar |
Contaminant Information
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There are no documents for this site report.
No associated sites were found.