ENV-14-36 Strategic Implications of Ozone NAAQS Developments on PSD Permitting

Description:

Petroleum and petrochemical facilities do not directly emit ozone; however, the vast majority of projects at these facilities involve increases of ozone precursors, NOX and VOC. Proposed projects causing emissions greater than 100 tpy of ozone precursors trigger the ozone ambient impact analysis requirements under the federal Prevention of Significant Deterioration (PSD) regulations. Ozone formation mechanisms are extremely complex, are affected by a number of variables, and are highly dependent on numerous atmospheric and geographical influences. Due to the photochemistry involved and the influence of transport on ozone formation, ozone impacts are typically assessed on a regional scale using complex and resource intensive photochemical grid models. Although the science and technology associated with these models has advanced significantly in the last few years, new analytical techniques or models for evaluating single source ozone impacts are still needed. U.S. EPA has committed to engage in rulemaking by March 2015 to evaluate updates to the Guideline on Air Quality Models (40 CFR Part 51 Appendix W, herein referred to as the Guideline) to address this need. This paper summarizes U.S. EPA’s progress in developing single source ozone impact assessment techniques as they pertain to common expansion projects at petroleum refineries and petrochemical facilities. In the absence of this upcoming U.S. EPA guidance or rulemaking, qualitative analysis techniques have been successfully applied in various industrial sectors across the U.S. Case study refinery expansion projects are presented outlining how these screening level qualitative assessment techniques can be applied. Finally, a concluding discussion is provided to highlight the implications of expected guidance and more stringent standards on single source ozone assessments.