Off-Site Stream Investigation Summary

• Initial screening of floodplain soil, surface water, sediment, and fish/crayfish was completed in October 2001.
  • Results of the October 2001 investigation indicated a general occurrence of PCBs in surface water, stream sediments, fish/crayfish, and flood plain soils along Bailey’s Branch and Pleasant Run to the east of the Plant.
  • PCB levels generally decrease with distance from the plant and the stream.
    
• 2.0 parts per million (ppm) for total PCBs was used as a screening level for floodplain soils.
  
• 2001 Stream Investigation Data Summary was distributed to U.S. EPA, IDEM, and USFWS on March 19, 2002.
  
• Additional floodplain soil sampling was initiated by GM in January 2002 based upon the results of the October 2001 sampling activities.
  • Over 3,000 samples collected to date.
  • Sample collection, sample analysis, data validation/ completion, and distribution to property owners is ongoing.
  • Results of 2002 stream investigation provide an understanding of the extent of the occurrence of PCBs in flood plain soils.
    
• Additional sampling has included:
  • Agricultural fields soil, corn, soil in vegetable gardens, cattle, and water from springs and seeps.
    
• High flow water sampling was conducted in May 2002.
  
• Summary Report of 2002 sampling was submitted to U.S. EPA and IDEM on February 11, 2003 and is available in the public repositories and on-line.