New Mexico Environment Department

1. New Mexico Environment Department The National Ambient Air Quality Standard (NAAQS) for Ozone

2. New Mexico Environment Department Presentation Outline • Criteria pollutants • How the ozone standard is set • Primary & secondary standards • 1-hour vs. 8-hour • Nonattainment areas

3. New Mexico Environment Department • Criteria pollutants • Ozone (O3) • Carbon monoxide (CO) • Sulfur dioxide (SO2) • Nitrogen dioxide (NO2) • Particulate matter (PM10 & PM2.5) • Lead (Pb) • National Ambient Air Quality Standards (NAAQS) are set by EPA for each pollutant.

4. New Mexico Environment Department How does EPA set the ozone standard? Clean Air Act requires EPA to regularly review standards for each criteria pollutant, and if necessary, update standards to “protect public health with an adequate margin of safety” based on the latest, best-available science. Consider only public health when setting standards. Cost of compliance considerations are addressed during implementation.

5. New Mexico Environment Department • To update the ozone standard, EPA did the following over the course of several years: • Scientific and technical assessment of thousands of peer-reviewed studies and data published in scientific journals • Synthesized the studies into criteria document detailing health and environmental effects of ozone • Technical staff prepared a staff paper to assess the policy implications of the science and identify: • Factors to be included in review • Uncertainties in data • Range of alternative standards to be considered

6. New Mexico Environment Department • EPA made recommendation as to whether existing standards are adequate to protect public health • Criteria document, staff paper, and recommendation presented to and reviewed by public, stakeholders, and Clean Air Scientific Advisory Committee (CASAC) • Over 125 hours of public discussion • Received 57,000 comments at hearings and in writing • Inter-agency review

7. New Mexico Environment Department • Based on 250 most relevant studies, CASAC concluded that ozone standard should be strengthened • CASAC made recommendation to EPA on adequacy of standard • EPA Administrator decided revising the standard was appropriate • EPA updated ozone standard from 0.12 ppm (1-hour) to 0.08 ppm (8-hour)

8. New Mexico Environment Department Primary and Secondary Standards For each criteria pollutant, EPA sets health-based or primary standards to protect public health, and welfare-based or secondary standards to protect the environment (vegetation, wildlife, visibility, national monuments, buildings, etc) 0.08 parts per million (ppm) is both the primary and secondary standard for ozone. An area’s design value is the 3-year average of the annual 4th-highest daily maximum 8-hour ozone concentration. San Juan County’s current design value is 0.076 ppm.

9. New Mexico Environment Department 1-hour vs. 8-hour Ozone Standards The 1997 update phases out the 0.12 ppm (1-hour) standard and replaces it with a 0.08 ppm (8-hour) standard to protect against longer exposure periods. The new standard was challenged in court, but was ultimately upheld by the U.S. Supreme Court in February 2001 (Whitman v. American Trucking Associations, U.S., No. 99-1257, 2/27/01). EPA’s implementation allowed for continued applicability of the 1-hour standard to areas not attaining it (does not apply to San Juan County).

10. New Mexico Environment Department Nonattainment Areas EPA is to make final designations for ozone nonattainment areas by April 15, 2004. (Texas will probably have 21 ozone nonattainment counties.) San Juan County’s current design value is 0.076 ppm. The Early Action Compact will determine what control strategies, if any, will help to keep the area in attainment.

11. New Mexico Environment Department More Information Fact sheets, rule packages: www.epa.gov/ttn/oarpg/naaqsfin/ Or, contact me: Andy Berger Air Quality Bureau (505) 955-8034 andy_berger@nmenv.state.nm.us