EPA ID# WA5170090059
EPA Region 10
Island County
Oak Harbor

2nd Congressional District

Last Update: May, 2010

Hide details for Site DescriptionSite Description

The Naval Air Station (NAS) at Whidbey Island, Ault Field is a Department of the Navy 8,000-acre facility and consists of Ault Field and the Seaplane Base. The Seaplane Base is also on the National Priorities List (NPL) and is being addressed in conjunction with Ault Field. The station was commissioned in 1942, and the air station's current mission is to maintain and operate Navy aircraft and aviation facilities and to provide associated support activities. Since the 1940s, operations at the air station have generated a variety of hazardous wastes. Site investigation studies have confirmed contamination of soil, sediments, and groundwater throughout the installation. Contaminants include polychlorinated biphenyls (PCBs), heavy metals, chlorinated solvents, polyaromatic hydrocarbons (PAHs), and pesticides.

The Ault Field site has been divided into four subsites for the purpose of managing cleanup activities. Subsite 1 consists of Area 6, a known landfill, and Area 5, a suspected disposal area. Subsite 2 is made up of the Walker Storage Barn, Pesticide Rinsate Area, Clover Valley Fire School, Western highlands Landfill, Area 3, and 1969-1970 Landfill. Subsite 3 encompasses Area 16, the runway ditch complex. Subsite 5 includes Area 1, the Beach Landfill, Area 52, Jet Engine Test Cell, and Area 31, the former Runway Fire School. An additional 26 site areas were investigated as part of the Hazardous Waste Evaluation Study to determine if these areas required more extensive investigation. As a result of this study, a fourth subsite was established, which consists of the beach landfill and Jet Engine Test Cell. The site lies on shallow and sea-level aquifers. These aquifers provide drinking water to approximately 21,000 people located within three miles of the site. Local surface water bodies are used for recreation and irrigation. One surface water intake, approximately 6,500 feet from the site, is used to irrigate 66 acres of farmland. A freshwater wetland is located within 500 feet of Ault Field.

Site Responsibility: This site is being addressed through federal actions.

NPL Listing HistoryDates
Proposed Date:09/18/1985
Removed Date:
Withdrawal Date:
Final Date:02/21/1990
Deleted Date:

Hide details for Threats and ContaminantsThreats and Contaminants

Media Affected: Soil, Sediments & Groundwater
Groundwater at the site is contaminated with volatile organic compounds (VOCs) including trichloroethylene (TCE) and trichloroethane (TCA). Ingestion of or direct contact with the contaminated groundwater could be a health hazard. As a result, the Navy has provided free connections to city water for residents whose drinking water wells could be impacted by the plume of contaminated groundwater. Soils and sediments contaminated with PCBs, heavy metals, pesticides, PAHs, and dioxin have been found at various locations throughout the site. While there is no immediate threat to human health, there are future human health as well as ecological risks in these areas.

Hide details for Cleanup ProgressCleanup Progress

The NAS Whidbey Island, Ault Field Superfund site consists of 4 project areas. Cleanup activities are complete at all of the project areas:

Operable Unit #1 - Area 6 Landfill: This area served as the main landfill for Navy operations at the air station. The remedial investigation revealed that groundwater beneath the landfill was contaminated with chlorinated solvents, and that the contaminants were moving off-site and threatening nearby private drinking water wells. In May 1991, the Navy began a voluntary program to provide access to city water to residents living close to the landfill. An Interim Action Record of Decision (ROD) was signed in April 1992, and a final ROD was signed in December 1993. As part of the cleanup effort, a groundwater pump and treat system has been built and the 40-acre landfill has been capped. The pump and treat system has been operating since June 1995, and cap construction was completed in October 1996.

Operable Unit #2 - Areas 2, 3, 4, 14, & 29: Project Area #2 consists of 2 landfills, a waste storage area, a pesticide rinsate disposal area, and a fire training area. Contaminants of concern include PCBs, PCP, dichlorophenol, dioxin, pesticides and PAHs. The ROD, signed in May 1994, called for digging up and disposing off-site approximately 5,000 cubic yards of contaminated soil. All construction activities for this project area have been completed; institutional controls are in place and the Navy will continue groundwater monitoring.

Operable Unit #3 - Runway Ditch Complex: The ditch complex consists of approximately nine miles of connected ditches and culverts that drain the runway area and receive discharge from many of the station’s storm drains. The majority of the ditches eventually connect into one stream that flows off-site toward a nearby lagoon and bay. Past dumping practices and spills have contaminated ditch sediments with total petroleum hydrocarbons, lead, arsenic and pesticides. A ROD was signed in April 1995. Approximately 6,000 cubic yards of contaminated sediments were excavated from the ditch complex and disposed of in project area #1 before capping. In May 1996, the Navy completed construction work, including restoration.

Operable Unit #5 - Areas 1, 52, and 31: this project area consists of a former fire training area, a jet engine test facility, and a landfill. The ROD was signed in May 1996. No contamination associated with the construction debris landfill was found. Studies at Areas 52 and 31 detected groundwater and soil contamination associated with leaking underground tanks. Contaminants of concern include PCBs, lead, total petroleum hydrocarbons, PAHs, VOCs, semi-VOCs and dioxins. Oil skimming and bioventing were selected as cleanup remedies. The Navy completed building and installing the remedies in October 1996. Bioventing has been discontinued at Area 31. The oil skimming system at Area 52 continues to operate.

NAS Whidbey Island, Ault Field has been designated as "construction complete," which signifies that all cleanup remedies required for the site have been implemented. A five-year review was completed in September 1998. The second Five Year Review was completed in March, 2004. In conjunction with this review, groundwater at the Area 6 landfill was tested for 1,4 dioxane, a stabilizer associated with chlorinated solvents. This previously undetected chemical compound was found in the groundwater at Area 6. To determine if this contaminant had spread off-site, the Navy sampled private wells adjacent to the landfill. The Navy sampled private wells in May and August of 2005. The chemical was detected in very low concentrations in several private wells. ATSDR has provided a health consultation and concluded that adverse health effects are not exprected to occur in adults or children at the concentrations detected in the private wells. Private well owners have been notified and It is too early to determine if additional remedial work is necessary to address 1,4, dioxane which cannot be removed by airstripping at the existing pump and treat system, so the Navy is planning on doing additional sampling. Several rounds of sampling have been completed (11/05, 4/06, 5/06, 8/06) and results indicate that almost all the private wells are below the state cleanup level or are non-detect. The Navy is working closely with EPA and the local Restoration Advisory Board .

Hide details for Regional ContactsRegional Contacts

SITE MANAGER(S):Nancy Harney
PHONE NUMBER:206-553-6635
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, WA 98370-7570
(360) 396-0002

Oak Harbor Public Library (Selected Documents)
7030 70th N.E.
Oak Harbor, WA 98277