Risk Assessment and Risk Management of PCBs in Gas Transmission Lines

On April 7, 2010, the Environmental Protection Agency (EPA) issued an Advance Notice of Proposed Rulemaking (ANPRM) entitled Polychlorinated Biphenyls (PCBs); Reassessment of Use Authorizations. In this ANPRM, the EPA proposes to reassess the existing PCB use authorizations under the Toxic Substances Control Act (TSCA), including the use authorization for PCBs in natural gas pipelines, air compressor systems and porous surfaces. As part of this reassessment, the EPA has proposed to revise and/or eliminate these use authorizations in a way that could significantly and dramatically impact natural gas pipeline operations. Natural gas pipelines have been subject to programs addressing PCBs for the past 30 years, starting with the EPA’s Compliance Monitoring Program (CMP) in the early 1980s to the EPA’s present comprehensive regulatory program, better known as the PCB Mega Rule.

The Interstate Natural Gas Association of America (INGAA) is a trade association representing virtually all interstate natural gas transmission companies operating in the United States. INGAA therefore has a direct interest in the EPA’s ANPRM and accordingly has prepared comments in response. In support of these comments, INGAA has commissioned several independent experts to prepare “White Papers” providing key analysis of the complex issues raised by the EPA’s ANPRM with respect to the presence of PCBs in the interstate natural gas pipeline system. These papers address pipelines and pipeline operations, the presence of residual PCBs in the pipeline system, the risks to health and the environment associated with PCB-impacted pipelines, the technical feasibility of removing increasingly diminished concentrations of PCBs and the anticipated economic impacts resulting from the EPA’s proposals.

Exponent was commissioned to analyze PCB toxicology and the exposure risks associated with residual PCBs in the interstate natural gas pipeline system and other topics of relevance to the natural gas pipeline industry.  While commissioned by INGAA in support of its comments, this report is an independent analysis, and its conclusions are based on the expertise of the authors.