Naval Base Kitsap (NBK) Keyport Operable Unit 2 is composed of two primary sites:
· Area 2 - Van Meter Road Spill/Drum Storage Area
· Area 8 - Plating Shop Waste/Oil Spill Area
OU 2, Area 2 - Van Meter Road Spill/Drum Storage Area
OU2, Area 2 is composed of three distinct sites: Van Meter Road spill area, Building 734 drum storage area and Building 957 drum storage area.
In 1976, approximately 2,000 to 5,000 gallons of plating shop wastes spilled from a tank truck on the pavement near Van Meter Road, impacting a nearby stream. Additionally, two unpaved areas associated with the two drum storage areas were active from the 1940s through the 1960s. These two areas were reportedly used to store all chemicals (including solvents, fuel/oil) used at NBK Keyport during this time period. It was estimated that between 4,000 and 8,000 gallons of these chemicals were discharged into these two areas.
The selected remedy for Area 2 included institutional controls to prevent the installation of domestic wells or use of the site for residential purposes in this area and annual groundwater monitoring to establish contaminant trends and determine when institutional controls may be lifted.
Contaminant concentrations in groundwater slightly exceeded the risk-based remediation goal for vinyl chloride in 2012 through 2018. Closure of this site will be re-evaluated during the next 5-year review in 2020.
OU 2, Area 8 - Plating Shop Waste/Oil Spill Area
OU2, Area 8 is a former plating shop and oil spill area immediately adjacent to Liberty Bay. Past releases included spillage of chrome plating solution from the plating shop onto the ground; discharge of plating wastes into a utility trench adjacent to the plating shop and leakage of plating solutions through cracks in the plating shop floor, waste disposal pipes, and sumps. In addition, petroleum hydrocarbons were discovered in the area prior to construction of a nearby building and were believed to have been the result of a leaking underground concrete vault historically used to store diesel and Bunker fuel oil. In addition, shallow groundwater discharges to Liberty Bay via seeps is suspected of contaminating adjacent sediments.
The Selected Remedy for OU 2, Area 8 is composed of the following:
· Removal and off-site disposal of vadose-zone soil from COC hot spots (completed)
· Groundwater monitoring in the water table aquifer (ongoing)
· Sediment and tissue monitoring to assess the potential long-term impacts of contaminated groundwater discharge to Liberty Bay (ongoing)
· Contingent groundwater control actions based on risk assessment of sediment and tissue monitoring data (has not been needed)
· Institutional controls (in place)
All of these remedies are in place or have been completed, as noted above.
The OU2 ROD acknowledged that “As natural restoration continues at Area 8, residual contamination may continue to be discharged into Liberty Bay for many years. Sediment and tissue monitoring will be done to assess whether these discharges accumulate over the long-term and cause impacts in Liberty Bay that may warrant implementation of groundwater control measures.” and that “The data collected from the Area 8 sediment and tissue monitoring program will be evaluated for human health risk…” and “…the sediment data will be evaluated for ecological risk…”
Based ROD requirements, the Navy has been working with the Washington State Department of Ecology, the U.S. Environmental Protection Agency and the Suquamish Tribe to develop and conduct a Human Health and Ecological Risk Assessment to determine if contaminant impacts warrant groundwater controls. In addition, an evaluation of the potential for vapor intrusion into adjacent buildings is also underway.