Site Report: UAA Aviation Technology Center UST 7
| Site Name: | UAA Aviation Technology Center UST 7 |
|---|---|
| Address: | 2811 Merrill Field Drive, Anchorage, AK 99501 |
| File Number: | 2100.26.616 |
| Hazard ID: | 26994 |
| Status: | Cleanup Complete |
| Staff: | No Longer Assigned, 9074655229 dec.icunit@alaska.gov |
| Latitude: | 61.214578 |
| Longitude: | -149.830608 |
| 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
A 1000-gallon dual chambered Aviation Gas / Jet A Fuel underground storage tank (UST #7), installed in 1993, was closed by excavation and removal in August 2018. The UST was located on the west side of the UAA Aviation Technology Center at Merrill Field. The Aviation Technology Center is built directly over a landfill cap roughly five feet in depth which covers roughly 20 or more feet of landfill debris. During excavation and closure activities a site assessment was conducted. Soil was collected for field screening using a photoionization detector (PID) to confirm the absence or presence of petroleum contaminants associated with this UST. Analytical soil samples were collected at select locations based on DEC UST Guidance and areas with the highest PID results. Analytical sampling detected benzo(a)pyrene levels in the north sidewall of the excavation that were over human health criteria and benzo(a)anthracene concentrations that were over migration to groundwater criteria. There is an additional location (south sidewall) that is also over migration to groundwater cleanup level for benzo(a)anthracene.
Action Information
| Action Date | Action | Description | DEC Staff |
|---|---|---|---|
| 8/21/2018 | Leaking Underground Storage Tank Cleanup Initiated - Petroleum | Jamie Grant | |
| 2/13/2019 | Site Added to Database | A new site has been added to the database | Mitzi Read |
| 2/13/2019 | Leaking Underground Storage Tank Release Confirmed - Petroleum | LUST site created in CSP database for source area 1,000-Gallon Av Gas / Jet A UST #7, 80361 | Mitzi Read |
| 4/4/2019 | Potentially Responsible Party/State Interest Letter | Potentially responsible party / state interest letter sent | Jamie Grant |
| 4/30/2019 | Document, Report, or Work plan Review - other | In 1993, a 1000-gallon dual chambered Aviation Gas / Jet A Fuel (gasoline) UST, was installed for the UAA Aviation Technology Center at Merrill Field to fuel aircraft engine maintenance operations. The UST was located directly atop Anchorage Merrill Field Landfill. The Anchorage Merrill Field Landfill cap is estimated to be around 5 feet below ground surface (bgs) and the landfill debris is estimated to be approximately 20 feet thick. On August 21, 2018, the UST and associated piping were excavated and removed. Additional excavation work was conducted to expose and remove two concrete slabs. Random debris was observed in the base of the excavation and noted. The final excavation measured approximately 13 feet by 18.5 feet at the surface, with an average depth of about 7 feet below ground surface (bgs). Approximately 62 cubic yards (cy) of material, were generated during excavation activities and reused as backfill. Groundwater was not observed below the UST and adjacent monitoring wells indicate groundwater level is 27 feet bgs. Given, the lack of detectable analytes in concentrations that would be consistent with gasoline related contamination, and a breach of the subsurface landfill cap (as evidenced by debris and reported cap depth), ADEC concurs with the conclusion that the two PAH analytes with elevated concentrations, are likely residual contamination from the landfill. Site assessment activities during the closure and removal of the UST were conducted in general accordance with 18 AAC 78 UST Regulations, ADEC Field Sampling Guidance, and the ADEC UST Procedures Manual. Field screening and analytical samples were collected to provide information about the presence or absence of petroleum contamination remaining in place. During the course of the site assessment and closure investigation, analytical soil samples were collected and analyzed for: • gasoline range organics (GRO); • diesel range organics (DRO); • benzene, toluene, ethylbenzene, and xylenes (BTEX); • volatile organic compounds (VOC); • polynuclear aromatic hydrocarbons (PAH); • Ethylene Dibromide (EDB); and • Lead Analytical results indicate two samples collected from the north and south sidewalls near the base of the excavation exceeded ADEC Method Two Soil Cleanup Levels established in 18 AAC 75.341(c) Table B1 and 18 AAC 75.341(d) Table B2. The contaminants of concern identified in these samples were benzo(a)pyrene and benzo(a)anthracene. GRO was not detected in the samples collected. All other detectable analytes were below applicable ADEC Method Two Cleanup Levels. | Jamie Grant |
| 6/28/2019 | Cleanup Complete Determination Issued | Given, the lack of detectable analytes in concentrations that would be consistent with gasoline related contamination, and a breach of the subsurface landfill cap (as evidenced by debris and reported cap depth), ADEC concurs with the conclusion that the two PAH analytes with elevated concentrations, are likely residual contamination from the landfill. In accordance with 18 AAC 75.325(c)(2), site cleanup rules do not apply to a permitted solid waste disposal facility that is regulated under 18 AAC 60. This UST site will receive a “Cleanup Complete” designation on the Contaminated Sites Database, subject to the following standard conditions. 1. Any proposal to transport soil or groundwater from a site that is subject to the site cleanup rules requires ADEC approval in accordance with 18 AAC 78.600(h). A “site,” as defined by 18 AAC 78.995 (134), means an area that is contaminated, including areas contaminated by the migration of hazardous substances from a source area, regardless of property ownership. 2. Movement or use of contaminated material in a manner that results in violation of 18 AAC 70 Water Quality Standards in prohibited. 3. Groundwater throughout Alaska is protected for use as a water supply for drinking, culinary and food processing, agriculture (including irrigation and stock watering), aquaculture, and industrial use. Contaminated site cleanup complete determinations are based on groundwater being considered a potential drinking water source. In the event that groundwater from this site is to be used for other purposes in the future, such as aquaculture, additional testing and treatment may be required to ensure the water is suitable for its intended use. This determination is in accordance with 18 AAC 78.276(f) and does not preclude ADEC from requiring additional assessment and/or cleanup action if future information indicates that contaminants at this site may pose an unacceptable risk to human health, safety, or welfare or to the environment. | Jamie Grant |
Contaminant Information
| Name | Level Description | Media | Comments |
|---|---|---|---|
| Benzo(a)anthracene | Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation | Soil | Given, the lack of GRO and other detectable analytes in concentrations that would be consistent with gasoline related contamination, and a breach of the subsurface landfill cap (as evidenced by debris and reported cap depth), ADEC concurs with the conclusion that the two PAH analytes with elevated concentrations, are likely residual contamination from the landfill. In accordance with 18 AAC 75.325(c)(2), site cleanup rules do not apply to a permitted solid waste disposal facility that is regulated under 18 AAC 60. |
| Benzo(a)pyrene | > Human Health/Ingestion/Inhalation | Soil | Given, the lack of GRO and other detectable analytes in concentrations that would be consistent with gasoline related contamination, and a breach of the subsurface landfill cap (as evidenced by debris and reported cap depth), ADEC concurs with the conclusion that the two PAH analytes with elevated concentrations, are likely residual contamination from the landfill. In accordance with 18 AAC 75.325(c)(2), site cleanup rules do not apply to a permitted solid waste disposal facility that is regulated under 18 AAC 60. |
Control Type
| Type | Details |
|---|---|
| No ICs Required |
Requirements
| Description | Details |
|---|---|
| Advance approval required to transport soil or groundwater off-site. | |
| 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) |
| Hazard ID | Site Name | File Number |
|---|---|---|
| 23188 | UAA Aviation Technology Center UST 4 | 2100.26.408 |
| 25102 | UAA - Aviation Complex, 1991 tank pulls | 2100.26.406 |