Problems/Comments

UST 1404 was a 500-gallon diesel buried fuel/oil tank installed in approximately 1986. Tank was decommissioned in 1990 to accommodate a new building footprint; sampling did not occur. This tank was used as an AST inside the former control tower. Required sampling did not occur; soil contamination is not characterized or confirmed. Updated 2012. Tank UST 1404 was installed in 1988 and is regulated by ADEC in accordance with 18 Alaska Administrative Code 78. The tank was removed from the ground in 1992 to accommodate a new building addition and a release investigation was not conducted at the time of the tank removal. The site is not listed in the LUST program; however, a release investigation was undertaken to achieve a cleanup complete site closure. A reconnaissance-level site visit and ecological site survey were completed in October 2009 as part of the Preliminary Assessment of the Former Galena Forward Operating Location (CH2M HILL, September 2011). The surface of the site was observed to be pavement and gravel. No surface staining was observed, and no viable ecological habitat was observed at Site UST1404 during the visit. In 2010 a site investigation was conducted under a ADEC approved workplan. Soil samples were collected from borings advanced on the north and south side of the former UST location to evaluate the presence or absence of contamination in shallow subsurface soil. Soil samples were collected from 9 to 10 feet below ground surface (bgs) and from 17.5 to 18.5 feet bgs at each boring location. Target analytes at Site UST1404 were identified in the workplan as gasoline-range organics (GRO); diesel-range organics (DRO); benzene, toluene, ethylbenzene, and xylenes (BTEX); and polynuclear aromatic hydrocarbons (PAHs). Soil samples were also screened for trichloroethene (TCE) and tetrachloroethene (PCE). No target analytes were detected in soil above the method 2, table B cleanup levels. Following the soil sampling, a geophysical survey was conducted in September 2010 to identify the presence of subsurface pipelines associated with former UST 1404-2; no subsurface pipelines were found. As specified in the ecoscoping form for Site UST1404, the site is covered with pavement and gravel, which does not provide viable habitat. Therefore, terrestrial ecological exposure pathways from soil are incomplete, and data were compared with non-ecological SI soil screening levels (SLs) to evaluate for the presence or absence of contamination in soil. Because the site is located more than 1,000 feet from the Yukon River, there is no potentially complete aquatic ecological pathway. Consequently, no ecological receptors were identified, and the site was not further evaluated for aquatic ecological risk. A cumulative risk evaluation was completed for the site by comparing the maximum concentrations of detected analytes to one-tenth of the ADEC Table B-1 value for direct contact in the Under 40 inch zone. No analytes detected were above the one-tenth criteria; therefore, there is no unacceptable cumulative risk for Site UST1404 soil.

Action Information

Contaminant Information

Control Type

Requirements

No associated sites were found.