Queen City Farms
Remedial Project Manager
206-553-2724 or 800-424-4372.
Queen City Farms Cleanup Backup Plan in Place
National Superfund Information
The EPA has revised its approach to the ongoing cleanup at the Queen City Farms Superfund Site, located on Cedar Grove Road in Maple Valley. The cleanup plan, called A Record of Decision (ROD), was issued in December 1992. Several contingent actions, or backup plans, were included in the ROD; to be used if cleanup goals were not met within a reasonable time. One of those backup plans, for ground water, will now be implemented.
The 1992 ROD’s objectives for ground water were to:
The initial approach of the cleanup was to wall off any water sources that were contaminated. Once the source was contained it was expected that contamination levels would naturally decrease over time. Seventeen years later, some of the contaminated ground water has, one, spread closer to the site boundaries and, two, still shows levels of contamination above the established cleanup levels.
The backup plan includes seven wells that will extract the contaminated water. The water will then go through a water treatment system. Once cleaned the water will go to an onsite gravel pit.
An Explanation of Significant Differences (PDF) (6 pp, 418K) is available for review.
Cleanup Review Ongoing
- Prevent exposure to contaminated ground water.
- Stop the flow of contaminated water to other areas.
- Restore ground water quality to usable levels.
We review cleanups at Superfund sites every five years, to make sure the cleanup continues to protect people and the environment. After the 2008 review we began additional groundwater investigations (see monitoring well location maps (PDF) (4 pp, 851K) to better characterize the groundwater contaminant plume; groundwater samples are collected twice a year to monitor the progress of the cleanup. The sampling results are available on request.
Queen City Farms is located on Cedar Grove Road (just south of King County Cedar Hills Landfill) in Maple Valley, Washington. The 324-acre Queen City Farms site includes two separate areas of contamination; the former waste pond and buried drum area in the eastern part of the property, and the former processing area in the center of the property. The processing area had relatively less contamination and the surface soils were removed to prevent contact with contaminated soil. Groundwater monitoring at this area of the site is conducted every five years. The main area of contamination was the result of buried drums and unlined ponds which were used to dispose of hazardous waste, including solvents, PCBs, and heavy metals. The start of the cleanup of this site involved an extensive removal action to properly dispose of the contaminated soil and sludge from the waste ponds. A barrier wall and a protective cap were used to contain the groundwater and soil beneath the former pond area. This area is now known as the Containment Area and contamination here is monitored regularly.