Overview map of the Wycoff-Eagle Harbor site (click on image for larger view)
During cleanup, a site may be separated into distinct areas depending on the complexity of the problems associated with the site. These areas - called operable units - may address geographic areas of the site, specific site problems, or areas where a specific action is required. The Wyckoff-Eagle Harbor site is made up of the following three operable units:
East Harbor Operable Unit: Subtidal and intertidal sediments of the outer harbor next to Wyckoff Point
In 1993 and 1994, EPA placed clean sediments over a 54-acre area of heavily contaminated sediments in the East Harbor Operable Unit. These clean sediments cap sediments polluted with polynuclear aromatic hydrocarbons (PAHs), and other organic compounds, as well as with metals, mainly mercury.
Oily seeps have continued to occur in the intertidal areas of West Beach, North Shoal, and East Beach. In 2007-2008, an exposure barrier system and cap were placed over the West Beach seeps. People use West Beach as part of Pritchard Park. EPA is currently sampling the North Shoal and East Beach to find out how far the seeps extend in these areas. EPA will evaluate alternatives to clean up the seeps.
EPA continues to monitor and maintain the existing sediment cap and remaining subtidal areas of concern. We check on the success of natural recovery in intertidal areas, and enhance existing institutional controls - such as "no anchor zones" - to reduce the chance that people will be exposed to contaminated fish and shellfish.
West Harbor Operable Unit: Sediments and uplands of former shipyard
Cleanup of the West Harbor Operable Unit included studying and controlling upland sources of contamination. Sediments contaminated with mercury were excavated and disposed upland, and a clean sediment cap placed over areas of concern. The 1992 cleanup plan (Record of Decision) for West Harbor was amended in 1995 to include building a nearshore fill and confined disposal facility (CDF) in intertidal areas next to the former shipyard property. The nearshore fill and CDF hold contaminated sediments. Contaminant sources at the former shipyard property were controlled to prevent soil contaminants from entering Eagle Harbor through groundwater seeps or surface water runoff. The CDF was built on lands owned by the Washington Department of Transportation (WSDOT). WSDOT monitors the CDF and capped areas to ensure the cleanup remedies continue to protect people’s health and the environment.
Soil and Groundwater Operable Units: Wyckoff Point area
The Soil Operable Unit includes the former Wyckoff wood treating process and storage area. Soil contamination is widespread here, with high levels of contamination in the former process area. Contaminants of concern in soil are PAHs, pentachlorophenol, and dioxins/furans.
The Groundwater Operable Unit includes the soil and groundwater in the saturated zone beneath the Soil Operable Unit. The Groundwater Operable Unit is made up of two water-bearing zones separated by a layer of clay and rock -- low-permeability material called the aquitard. Pools of contaminated liquid (oil, tar, creosote, and more) are in the zone beneath the former process area, and above the aquitard. The aquitard prevents contaminants from moving into the groundwater below.
In 2001, EPA built a sheet pile wall around the contaminated areas of the point and did a thermal pilot study. The pilot study showed that steam injection would successfully remove contamination. However, we were concerned that this technology would not remove enough contamination to reach cleanup standards. Therefore, we did not carry out a full scale steam injection remedy. EPA is working with the Washington Department of Ecology to determine if source removal alternatives like thermal remediation can be done on a full scale in the soil and groundwater operable units. In 2008, EPA built a new groundwater treatment plant to replace the 25-year-old plant built by the Wyckoff Company. The groundwater treatment plant extracts and treats the groundwater to help contain the contamination within the former process area.