Problems/Comments

Characterization and cleanup activities conducted under the regulatory authority of the ADEC began in 1998 following a site investigation conducted the same year by Ogden Environmental and Energy Services Co., Inc. (Ogden) under contract for the AKARNG and is documented in the Preliminary Assessment/Site Investigation dated January 1998. Ogden collected ten field screening soil samples and five (5) analytical soil samples from the FSA in August of 1996. These samples were collected from three (3) areas of concern: the AST, the drum storage area, and the culvert. Soil was field screened using a field-portable infrared spectrophotometer and analytical samples were analyzed for DRO and TPH. Select samples were additionally analyzed for GRO and BTEX. The results of the investigation found that there was petroleum contamination at all 3 areas investigated. Contamination at the AST was found at up to 19,000 mg/kg DRO and 16,000 mg/kg TPH. Lower concentrations (up to 1,000 mg/kg TPH and 370 TPH) were found near the culvert and drum storage area. None of the GRO and BTEX components were detected. A remedial action was performed by Brice Environmental on behalf of the AKARNG in September 2016. This action is documented in the report Remedial Action Report Fort Yukon Federal Scout Readiness Center (FSRC), dated November 2016. According to the report, there were two (2) locations requiring excavation due to DRO and methylnaphthalenes concentrations exceeding the cleanup level established in the ROD. Excavation 1 was located adjacent to the FSRC building near the former location of the AST and Excavation 2 was southeast of the FSRC building near a culvert. Excavation of contaminated soil at both location was guided by a photoionization detector (PID). Post-excavation confirmation samples were collected from field screening samples having the highest PID readings. At Excavation 1, approximately 14 cy of contaminated soil was removed to a maximum depth of about 5.2 feet below ground surface. A total of 37 PID samples were collected and seven (7) confirmation samples and a duplicate were collected and analyzed for DRO, 1-methylnaphthalene, and 2-methylnapthalene. Final DRO concentrations in Excavation 1 ranged from non-detect to 6,000 mg/kg. The remaining concentration of 1-methylnaphthalene ranged from non-detect to 3.8 mg/kg and from non-detect to 2.7 mg/kg for 2-methylnaphthalene. Excavation 2 was located near a culvert and 32 PID samples were collected during the excavation of approximately two (2) cy of contaminated soil. The excavation was at a maximum depth of about five (5) feet below ground surface. Final confirmation samples from the excavation had DRO concentrations ranging from 1,600-6,600 mg/kg, 1-methylnaphthalene was not detected, and 2-methylnaphthalene was 0.024-0.071 mg/kg. The clean overburden (10 cy) from the excavations was also field analyzed (15 PID readings) and two (2) samples were submitted for DRO and PAH analyses. The resulting DRO concentrations (790-6,300 mg/kg) were below cleanup levels as were the concentrations of 1 and 2-methylnaphthalenes (0.04-2.6 mg/kg). This clean overburden was used for backfill. Approximately 19 cy of contaminated soil was transported to Organic Incineration Technology Inc. (OIT) in North Pole for treatment. Certificates of thermal treatment for this soil were received by ADEC on September 7, 2017. After this remedial action, as demonstrated by the confirmation samples, the remaining soils on site meet the cleanup levels established in the ROD.

Action Information

Contaminant Information

Control Type

Requirements

No associated sites were found.