Technology:
Thermal Desorption - Rotary dryer desorber - Temperature of soil exiting heating chamber ranged from 833 to 1,080xF - Soil residence time 15 minutes - Offgases - routed through a baghouse, a water quenching unit, a reheater, and a vapor phase carbon adsorption bed
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Cleanup Authority:
CERCLA (Removal Action) and State: Georgia - Unilateral Administrative Order - 3/92 - PRP Lead
SIC Code:
2879 (Pesticides and
Agricultural Chemicals,
Not Elsewhere Classified) | Point of Contact:
R. Donald Rigger
On-Scene Coordinator
U.S. EPA Region IV
345 Courtland Street, N.E.
Atlanta, GA 30365
(404) 347-3931 |
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Contaminants:
Halogenated Organic Pesticides - Dieldrin, toxaphene, DDT, lindane |
Waste Source:
Manufacturing Process |
Type/Quantity of Media Treated:
Soil - 4,300 tons - Bulk density - 125.8 to 129.7 lbs/ft3; moisture content - 13 to 19%; pH - 5.7 to 6.2; particle size distribution - up to 2.38 mm; TOC - 0.2 to 0.23 mg/kg |
Purpose/Significance of Application:
First full-scale application of thermal desorption under the Superfund program to remediate soil contaminated with a mixture of organochlorine pesticides. |
Regulatory Requirements/Cleanup Goals:
Cleanup goals identified in March 1992 Unilateral Administrative Order and October 1992 Treatability Variance for proof-of-process performance test and full-scale treatment - Total OCL pesticides < 100 mg/kg and 4 constituents (DDT, toxaphene, BHC-alpha, BHC-beta) > 90% measured reduction in concentration; air emissions - stack gas total hydrocarbons < 100 ppmv - Additional air emissions limits during proof-of-process test - Georgia Guideline for Ambient Impact Assessment of Toxic Air Pollutant Emissio |
Results:
The cleanup goals for soil were met for both total OCL pesticides and individual constituents - Air emission standards were achieved during both the proof-of-process test and during the full-scale remediation - Average OCL pesticides concentration in treated soil was 0.51 mg/kg - Average removal efficiencies for individual constituents were greater than 98% |
Cost Factors:
Estimated Total Treatment Cost - $849,996 (including solids preparation and handling, mobilization, startup, system operation, and demobilization) - Estimated Before-Treatment Costs - $252,582 (including mobilization and preparatory work, monitoring, sampling, testing, and analysis, including the treatability study) |
Description:
The T H Agriculture & Nutrition (THAN) Company Superfund site in Albany, Georgia was used from the 1950s to 1982 for pesticide formulation and storage. As a result of these operations, soils at the site were contaminated with pesticides, primarily organochlorine (OCL) pesticides and the site was placed on the National Priorities List (NPL) in 1989. In March 1992, EPA issued a Unilateral Administrative Order to THAN for removal of contaminated soil and debris. Contaminated soil with concentrations of OCL pesticides greater than 1,000 mg/kg was excavated and stockpiled.
Thermal desorption was used at THAN to treat approximately 4,300 tons of stockpiled soil contaminated with OCL pesticides. The thermal desorption unit consisted of a rotary kiln thermal desorber operated at 833 to 1,080xF (soil exit temperature) and a 15-minute residence time. An interlock (waste feed cutoff) process control system was used in this application to maintain operation of the unit within allowable limits. The system was operated from July to October 1993. Thermal desorption achieved the specified cleanup levels for OCL pesticides and air emission rates. Total OCL pesticide concentrations in the treated soil ranged from 0.009 to 4.2 mg/kg with an average concentration of 0.5 mg/kg. Average removal efficiencies for the four target OCL pesticides were greater than 98%.
The total estimated treatment cost for this application was approximately $850,000. The proof-of-process performance test results provided information on operating conditions and air emissions that were used for the full-scale treatment application. In addition, the bench-scale treatability study provided data to support a treatability variance request by THAN, approved by EPA in October 1992, to place treated soils on site. |
