Establishing PCB Cleanup Levels for Historical Spills in Texas

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Courtesy of Weston Solutions, Inc

INTRODUCTION

Polychlorinated biphenyls (PCBs) are a mixture of chlorine atoms and biphenyl molecules that combine to form complex chlorinated organic compounds that were manufactured and widely used in the United States from the 1940s through 1978. The chemical characteristics of PCBs made them desirable for use because of their electrical properties and low flammability. Unfortunately, the PCBs are also very persistent in the environment.

The manufacture and unauthorized use of PCBs were banned in 1978 because of concerns about PCB carcinogenicity and bioaccumulation in humans and the ecosystem. Since that time, PCBs have been treated as a significant environmental threat. In Texas, both State and Federal environmental agencies regulate releases of PCBs to the environment. The result of this dual regulatory applicability is that two complex sets of regulations have been developed to address PCBs in soil.

The U. S. Environmental Protection Agency (USEPA) regulates PCBs at the federal level under the authority of the Toxic Substances Control Act (TSCA). Using this authorization, the agency has promulgated extensive regulations in Title 40, Part 761 of the Code of Federal Regulations (40 CFR 761) regarding the manufacture, sale, use, cleanup, and disposal of PCBs in the United States. These regulations were substantially revised on 28 June 1998 with the adoption of the PCB Disposal Amendments, which, among other things, specified cleanup levels for historical releases of PCBs to soil. The Texas Natural Resource Conservation Commission (TNRCC) regulates PCBs at the State-level under the newly-adopted Texas Risk Reduction Program (TRRP), found in Chapter 30, Subchapter 350 of the Texas Administrative Code (30 TAC 350). The TRRP replaces the older 30 TAC 335 Subpart S Risk Reduction Rules and provides a risk-based approach for addressing soil and groundwater contamination in Texas. The TRRP includes PCB cleanup criteria. The TRRP and TSCA regulations provide different risk-based approaches for managing and remediating PCBs in soil. Most notably, the default PCB cleanup levels specified by each regulation are not the same. Consequently, it is possible to select inconsistent and conflicting PCB cleanup levels for soil through misapplication of the rules. This paper was prepared to compare the TRRP and TSCA cleanup levels for PCBs in soil, discuss the conflicts that may arise as a result of the coapplication of the two regulations, and provide assistance for correctly selecting PCB cleanup levels in Texas.

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