Problems/Comments

This site was originally a 14-bay cold-storage warehouse for the US Army. One of the warehouse bays was equipped with a mechanic's well. There were no reports of underground storage tanks onsite, however, one bay may have contained an aboveground storage tank that fed a drip-pot burner. Sometime between 1998-2003, the warehouse building was removed from the property. A limited site assessment was performed in February 2020. The results from the site assessment showed no known spill cases on the property, however there is evidence of historical contamination. Fill material with a sheen and fuel odor was observed near the old mechanic's bay during excavation. Field screening, visual, and olfactory observations indicated that this material was impacted by petroleum hydrocarbons. Lab results show two sampling locations on the property with DRO and RRO levels that exceed the ADEC default cleanup levels. One groundwater sample was analyzed for GRO, DRO, and RRO. The groundwater sampling results did not exceed the ADEC groundwater cleanup levels. Based on review of environmental records associated with the Southeast Alaska Regional Health Consortium (SEARHC) Halibut Point Road located at 802 and 810 Halibut Point Road in Sitka, Alaska, it has been determined that the contaminant concentrations remaining on site do not pose an unacceptable risk to human health or the environment and no further remedial action will be required unless information becomes available that indicates residual contaminants may pose an unacceptable risk. Initial soil contamination was located near a historical Mechanics Pit, and had concentrations exceeding the most stringent cleanup levels for DRO (up to 1,830 mg/kg) and RRO (14,000 mg/kg). A silica gel analysis (SGA) was then completed due to the low percent solids and high organics of the material sampled. Following the SGA, the level of RRO was reduced to levels below MTG cleanup levels (from 14,000 mg/kg to 1,950 mg/kg). However, DRO levels reduced from 1,830 mg/kg to 447 mg/kg, remaining above MTG cleanup levels. The reduction in RRO and DRO suggest some contamination is from a biogenic source. The remaining RRO contaminated soil was removed during the 2023 Mechanic’s Pit excavation. Groundwater samples collected yielded no Table C exceedances. In April of 2023, approximately 80 tons of impacted soil were removed offsite. During the summer of 2023, an additional 8,000 cubic yards of soil was removed offsite. Prior to removal, soil was observed for any evidence of contamination and field screened using a photo-ionization detector. There was no indication of hydrocarbon contamination in the remaining removed soil. 2023 Cleanup Complete letter is attached to the site in the CSP database.

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Requirements

No associated sites were found.