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EPA PROPOSES MODIFICATION TO KOPPERS GROUNDWATER CLEANUP, SEEKS COMMENT

Release Date: 3/23/1999
Contact Information: Leo Kay, U.S. EPA, (415)744-2201

    SAN FRANCISCO   The U.S. Environmental Protection Agency is seeking public comment on its proposal to modify the groundwater remedy at the Koppers Company, Inc. Superfund Site in Oroville, Calif.  

     The EPA will hold a public meeting to discuss these modifications and seek public comment at 7 p.m., March 23 at Oakdale Heights School, 225 Las Plumas.  The public comment period is from March 15 through April 13, 1999.

     Under the current remedy, the EPA is pumping and treating contaminated groundwater in and around the site using a process called "carbon adsorption," which filters out pollutants such as barium and pentachlorophenol.  

     Based on studies and monitoring data, the EPA is proposing to modify the groundwater
remedy by:

     waiving groundwater cleanup at the former creosote pond area and former cellon blow
     down area because it is technically impossible to remove the residual immobile
     contaminants (surface soil source materials have been removed, monitoring will be
     conducted and a backup pump and treat system will remain in place to protect public
     health;

     on-property augmenting the current pump and treat system with enhanced in-place
     bioremediation to speed up the groundwater cleanup;

     off-property replace the suspended pump and treat operations with enhanced in-place
     bioremediation;

     add monitored natural attenuation as a contingency remedy to be implemented should
     future studies justify it is appropriate for isolated low concentration residual
     contamination.

     The EPA does not plan to modify the soil cleanup plan announced in 1996, which involved the removal and placement in an on-site landfill of more than 109,000 cubic yards of contaminated soils in 1996 & 97.  The remaining 20,000 cubic yards of contaminated soil under the process area will be remediated in the future when the process area equipment is replaced or wood treating operations cease as agreed to in the consent decree.

     The public can make comments in person at the community meeting on March 23, 1999 or in writing or verbally to Charles Berrey, U.S. EPA Region 9, 75 Hawthorne Street, San Francisco, CA 94105, (415) 744-2223.  Written comment must be postmarked not later than April 13, 1999.  Copies of the EPA proposed plan are available at the Oroville Public Library or by calling Jackie Lane at (800) 231-3075.