|
|
Public Meeting
U.S. Environmental Protection Agency
Ciba-Geigy Site
Toms River, New Jersey
|
The Following is information supplied by the EPA at the April Meeting on the Ciba-Geigy Superfund Site.
In-Situ Bioremediation Pilot Study
Purpose Of Study
To investigate the use of in-situ aerobic bioremediation for treatment of soils containing relatively high concentrations of chlorinated organic compounds
Establish potential rates of mass removal
Determine operating conditions for optimizing biological process
Location Selected Based On:
High Concentrations of Typical Site Contaminants
Typical Site Geology (Cohansey Sands)
Clay Layer at 30 Feet (Acts as Cell Bottom)
Construction began in July 1996
-Pilot study cell measures 30 x 30 x 30' and contains approximately 3 million pounds of Soil
-Cell surrounded by steel sheet-piling
Pilot study cell operation began in December 1996
Construction of Bio-Pilot Cell at Ciba
Further construction of Bio-Pilot Cell at Ciba
Cover (White enclosure) of Bio-Pilot Cell at Ciba
Soil Results
Cell Initially Sampled in June 1996
1500 samples subjected to field screening
125 analytical samples analyzed to determine initial
mass of contaminants in cell
Approximately 672 pounds of initial contaminant
mass estimated in cell
Three contaminants (chlorotoluene, 1,2 dichlorobenzene, and 1,2,4-trichlorobenzene) constitute 98% of the mass
Samples were collected from the cell three times
June 1996
May 1998
January 1999
Results:
400 lbs of contaminant mass removed
57% contaminant mass removal
Bio-Pilot Cell- Process Schematic
Groundwater Results
Significant decrease in contaminant concentrations over first year of operation
Chloride ion increase over first operating year indicated contaminant degradation
Low contaminant concentrations maintained after oxygen delivery shut down in February 1999
Study Conclusions
Significant mass removal in soils
Removed more mobile and accessible compounds which are likely to impact groundwater quality
Contaminant reduction due to biological activity
Groundwater concentrations reduced substantially
One to two year treatment time frame
Gained insight on operating conditions for implementation of full scale system
|
 BACK
||
CONTENTS
||
NEXT
|
|
|
