Problems/Comments

Diesel fuel contamination from abandoned underground fuel storage tanks, most related to heating fuel. Building 3475 was a latrine located east of Building 3465. The 300 gallon heating oil UST-3475 was removed in 1997 along with one cubic yard of impacted soil. The maximum concentraion of DRO detected in samples from the UST excavation was 1800 mg/kg. During a remedial investigation and interim removal activities in 1997, UST 3475 was removed along with approximately 1 cubic yard (cy) of soil around the UST (See enclosed Figure 5-6). In 2000, an 11-foot by 20-foot area was excavated to 4 ft bgs in the vicinity of the previously detected remaining contamination (Figure 5-6). At 4 ft bgs, field screening results indicated that all the contaminated soil had been removed from the site. Approximately 10 cy of petroleum, oil and lubricant (POL) impacted soils were containerized and transported off-site for treatment. The area was then backfilled with clean fill and seeded. In order to fully characterize the site, two test pits were dug outside the excavation area in 2000. The first test pit, TP-l, was dug approximately 25 feet west of the excavation and 15 feet south of Ptarmigan Road between the excavation and a small creek (Figure 5-6) TP-l was advanced until groundwater was encountered at 8 ft bgs. A well point (3475 WP-l) was installed at TP-l to a depth of 8 ft bgs with the bottom three feet screened. The second test pit, TP-2, was an extension of the northeast corner of the excavation and stopped just short of Ptarmigan Road (Figure 5-6). TP-2 was advanced to 6 feet bgs, where water was observed seeping into the excavated area. A well point (3475 WP-2) was installed at TP-2 to a depth of 6 feet bgs with the bottom 3 feet screened. Additionally, five soil analytical samples were taken from each test pit, (one from each sidewall and one from the base of the excavation) were collected as excavation confirmation samples. The soil samples were analyzed for DRO, RRO, and BTEX. All soil samples contained DRO exceeded the most stringent Method Two CUL with the highest at 1,870 mg/kg. Total Organic Carbon (TOC) samples collected in 2000 from the uncontaminated stockpile and uncontaminated walls in TP-1 and TP-2, at 2 and 4 ft bgs, were used to determine the FOC value of 0.016 g/g and calculate a Method 3 ACL for DRO of 3,500 mg/kg (See enclosed calculations). During the sampling effort in 2000, groundwater (3475 WP-1 and 3475-WP-2), surface water and sediment were sampled from Ptarmigan Creek. There were no contaminants of concern detected in any of the samples. An ACL was calculated for the site which was closed with no institutional controls June 25, 2025

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No associated sites were found.