48    RISK-BASED CORRECTIVE ACTION AT A
CHEMICAL MANUFACTURING FACILITY
Greg A. Gilliland. Principal Engineer
Texas Eastman Division, Eastman Chemical Company
Longview, Texas 75607
Ram D. Ramaswami, Senior Project Manager
Parsons Engineering Science, Inc.
Denver, Colorado 80290
ABSTRACT
This chapter summarizes a risk-based approach to support bioremediation as a technology for
site closure. The approach to closure was presented to the Texas Natural Resource Conservation
Commission (TNRCC). TNRCC has approved the permit modification, and full-scale bioremediation of the lagoon sludge and soil mixture is currently underway. This risk-based corrective approach by Texas Eastman Division will result in substantial cost savings and is protective of
human health and environment.
INTRODUCTION
Risk assessment is used as a risk management tool to integrate remedial action alternatives and
to establish cleanup criteria. The risk assessment process is a detailed scientific evaluation of the
site including hazard identification, toxicity assessment, and exposure assessment, resulting in
characterization of site-specific risks.
As a remedial alternative, bioremediation has the advantages of being cost-effective as well as
environmentally sound. The risk assessment is complementary to bioremediation because it ensures cleanup to acceptable levels based on health and environmental protective criteria without
excessive costs. The risk-based approach to closure using bioremediation as a remedial alternative is being implemented at the Texas Eastman Division (TEX) of Eastman Chemical Company.
TEX manufactures organic chemicals at the Longview, Texas Facility. Past operations in the
wastewater treatment lagoons have generated sludges that are defined as hazardous under the Resource Conservation and Recovery Act (RCRA). Wastewater discharges in Lagoon 1 ceased in
1983. Under the original closure plan,1 the pumpable sludge in the lagoon was removed and
treated in an on-site incinerator. Approximately 15,000 cubic yards of sludge and soil mixture remain in Lagoon 1. TEX found it impractical to continue burning at the high rate anticipated in
the closure plan. High silica content of the sludge and soil mixture has caused operational problems including kiln shutdown. The generated ash consumes a large amount of scarce hazardous
landfill space. In the revised Closure Plan for Lagoon 1, TEX proposed to bioremediate the remaining sludge and soil mixture.
This chapter is organized into six sections. The introduction includes a brief description of the
project. Section 2 addresses the bioremediation demonstration study and the results of the study.
Section 3 presents the site-specific risk assessment approach and the results of this approach.
Section 4 presents the current status of the project. Section 5 acknowledges the various people
and organizations who made significant contributions to this project, and Section 6 presents the
references used in this study.
52nd Purdue Industrial Waste Conference Proceedings. 1997, Ann Arbor Press. Chelsea, Michigan 48118. Printed in
U.S.A.
477