EPA ID# WA5170027291
EPA Region 10
Kitsap County

1st Congressional District

Other Names: Sites C,D, & F, US Navy Bangor Submarine Base, US Navy -Naval Submarine Base-Bangor
Last Update: September, 2007

Hide details for Site DescriptionSite Description

The Bangor Naval Submarine Base site is a 7,000-acre facility located along Hood Canal near Silverdale, Washington. From the early 1940s until 1973, Bangor's principal mission was to store, process, and ship munitions. In 1977, the facility was recommissioned as a submarine base with the primary mission of supporting the Trident submarine fleet in the Pacific. Past releases of chemicals to the environment at the base were primarily related to the detonation, demilitarization, and disposal of explosive ordnance, and to industrial activities in support of the base mission. The Navy conducted an initial assessment study at Bangor in 1983, identifying 42 potential contaminant source areas which might warrant further investigation. Of those, 20 were subsequently determined to present no concern. The Navy initiated a program of investigations at the remaining 22 sites to determine the nature and extent of any contamination that might be associated with them.

Bangor is home to approximately 5,100 residents, including active military personnel and their families. The facility employs approximately 11,000 military and civilian personnel. The surrounding residential communities have a combined population of approximately 60,000 persons. Another parcel at this facility, Bangor Ordnance Disposal (Site A), was placed on the National Priorities List as a separate listing in 1987.

Site Responsibility: This site is being addressed through federal actions. The Navy is the lead agency for the cleanup at Bangor. The State of Washington Department of Ecology is the lead regulatory agency.

NPL Listing HistoryDates
Proposed Date:07/14/1989
Removed Date:
Withdrawal Date:
Final Date:08/30/1990
Deleted Date:

Hide details for Threats and ContaminantsThreats and Contaminants

Media Affected: Groundwater, Soil & Sludges, Surface Water
Groundwater, soils, surface water, and sediments contain TNT and RDX. People may suffer adverse health effects if they accidentally ingest or come into direct contact with contaminated groundwater, soils, surface water, and sediments.

Hide details for Cleanup ProgressCleanup Progress

The Navy has organized cleanup activities at Bangor Naval Submarine Base into seven units (Operable Units 2 through 8; Operable Unit 1 is the Navy's designation for the separately-listed Bangor Ordnance Disposal (USNAVY) site). These seven OUs comprise 21 individual sites as identified in the 1990 Federal Facility Agreement (FFA), as well as an area of groundwater contamination originating in the base Public Works Industrial Area that was added to the FFA in 1994. Environmental investigations concluded that OU4 and OU5 merited no further action and that OU3 required no further action with limited monitoring. For OU6 and OU 7, the Navy has completed the requirements of the ROD for these sites and no further action is required other than monitoring and institutional controls. The background and current status of the other OUs are discussed in greater detail below.

OU2 - Site F: Ordnance Washout Lagoon
Site F is the former location of an unlined evaporation lagoon and overflow area which was used in the demilitarization of ordnance between 1960 to 1971. Early phases of the investigation of the site found that soils and groundwater were contaminated with the ordnance compounds TNT, RDX, and DNT. In 1991, an interim remedy called for extraction, treatment, and reinjection of groundwater for the purpose of controlling migration of the contaminant plume was installed. A Granulated Activated Carbon groundwater treatment system went into operation in 1994. In 1994, the final ROD selected continued pumping and treating groundwater, composting of contaminated soils at the former lagoon, and installation of an infiltration barrier to control contaminant leaching. The soil treatment was completed in 1996. Operation of the groundwater system is ongoing.

OU8 - Public Works Industrial Area Groundwater
Operable Unit 8 comprises a plume of contaminated groundwater underlying several sites located in Bangor's Public Works Industrial Area (PWIA) and an adjacent residential area beyond the southeastern base boundary along Mountain View Road.
Since the inception of the Bangor facility, the PWIA has been the location of industrial activities supporting the base's different missions, including maintenance and cleaning of vehicles and locomotives, painting and corrosion control, electrical equipment maintenance, pesticide and herbicide storage and mixing, and vehicle fueling. Numerous underground tanks storing waste oils, diesel fuels, and gasoline have been located in the PWIA at various times. A tank overflow piping system failed in the early 1980s and released an estimated 20,000 gallons of unleaded gasoline at the public works gas station.

The plume was originally identified early in 1994 when a residential drinking water well was installed at one of the adjacent to the base. The local health department had tested the well prior to approving it as a source for a water supply, the test found volatile organic compounds (VOCs) in the water sample. Additional sampling of this well and seven other nearby neighborhood wells confirmed that the extent of the VOC contamination was at the time limited to the one new well. As a precaution, the Navy provided bottled water to residences in the Mountain View Road area. In December 1994, the Navy initiated a removal action to connect residents in the Mountain View Road area to a municipal water supply, and to begin evaluating the nature and extent of the groundwater contamination. The plume was found to be composed primarily of benzene and the chlorinated solvent 1,2-DCA. It was approximately 900-feet wide and one-half mile in length and appeared to originate in the PWIA. The connection of residences to the municipal water system was completed by autumn of 1995. In January 1996, the Navy began another removal action to capture contaminants at the base boundary. This containment and treatment system, which captured groundwater as it approaches the edge of the base and removes the contamination before returning the water to the aquifer, became operational in May 1997.

A more detailed investigation of the site and an evaluation of cleanup alternatives was completed early in 2000. While the investigation confirmed that the groundwater plume originates in the PWIA, there are no indications that any defined sources of contaminants exist in the soils there. The plume appears to have attained a steady state. The investigation also confirmed the presence of a layer of gasoline floating on the groundwater in a relatively small area within the PWIA near the public works gas station. The evaluation of alternatives concluded that the groundwater containment system would provide little benefit to the overall cleanup of the plume, and in December 1999, the Navy discontinued the system's operations. The ROD for OU8 was signed in September 2000, selecting a remedy of institutional controls, monitored natural attenuation to address the groundwater contaminant plume, and recovery of free fuel products in the PWIA to control the source of benzene. The implementation of the remedy is ongoing. The site was designated construction completion on September 25, 2001.

In 2000, the Navy completed a Five-Year Review to evaluate the continued protectiveness of its ongoing cleanup actions at the facility. An Institutional Controls Management Plan was completed in July 2002, and a Land Use Control Instruction is currently being developed to improve the enforceability of those elements of cleanup actions across the facility.

A Five-Year Review was completed in 2005. The Site F groundwater treatment system is not functioning as intended by the ROD. The OU-8 benzene concentrations in the core of the groundwater plume exhibit an increasing trend over at least the last 4 years. Follow-up actions include optimization of the Site F groundwater treatment system and continued monitoring focus on benzene concentrations in the core of the OU-8 groundwater plume.

The next Five-Year Review is scheduled to be completed in 2010.

Hide details for Regional ContactsRegional Contacts

PHONE NUMBER:503-326-3689

Chung Ki Yee (state)
E-MAIL ADDRESSmick.butterfield@subase.nsb.
PHONE NUMBER:360-396-5100
Information pertaining to this site is housed at the following location(s):
Engineering Field Activity Northwest (Administrative Record)
Naval Facilities Engineering Command
19917 7th Avenue NE
Poulsbo, Washington 98370-7570
(360) 396-0002

Kitsap Regional Library (Selected Documents)
1301 Sylvan Way
Bremerton, WA 98310

Bangor Naval Submarine Base Library
Building 2500
Silverdale, WA 98315

Kitsap County Public Utility District
1431 Finn Hill Road
Poulsbo, WA 98370