Split PM, Ozone Proposals

Published June 1, 1997

TNRCC’s Commissioners on March 6 agreed to recommend to EPA officials that they separate the proposed ground-level ozone National Ambient Air Quality Standards (NAAQS) revision from the proposal for regulating fine particulate matter (PM 2.5), and then to report to the federal court that mandated some action on particulates that the science is not available to establish a meaningful standard. They also recommended maintaining the current standard for ozone until EPA can produce sound, conclusive scientific studies that support a new standard.

According to TNRCC Chairman Barry McBee, “The only thing which is clear in this debate is that there are still questions about our understanding of ozone, questions that do not justify implementation of a new ozone standard. The EPA needs to do its homework before imposing this on the states, communities, and people of Texas and the United States.” A brand-new EPA study, for example, casts new doubts about the health effects of an eight-hour standard (which is being proposed) for ozone in the nation’s two most ozone-polluted cities: Los Angeles and Houston.

The current ground-level ozone standard is 0.12 part per million (ppm), averaged over one hour, but EPA has proposed to redesign the standard for eight-hour averaging and 0.08 ppm. Environmental and public health groups (like the American Lung Association) have agreed that the appropriate standard would be 0.07 ppm averaged over eight hours, while others have suggested that 0.09 ppm would be more acceptable. Although the Commissioners cited their preference for a “no-action” approach for now, they also stated their preference for the 0.09 ppm, eight-hour standard if EPA insists on implementing some new standard–a level that provides at least as much health protection as the current 0.12 ppm one-hour standard. Under a tougher standard, several Texas communities, including Austin, San Antonio, Corpus Christi, Victoria, and Longview-Tyler-Marshall, could fall into non-attainment status, triggering mandatory air pollution controls and requiring scores of new facilities to submit to environment regulation.

As for the fine particulates proposal, Commissioner Ralph Marquez explained, We know even less about particulate matter than we do about ozone, yet EPA is ready to propose a standard. There is information out there that there are potential health effects from fine particulate matter. But the scientists who advised EPA on this matter could not even agree on a standard. How can I vote for a standard that the scientists can’t agree is the right one?” The Commissioners agreed that more research is needed on the health effects of these small particles before imposing a new regulatory regime.