E7-11960. Oxides of Nitrogen and Sulfur (NOX

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of workshop.

SUMMARY:

The EPA is announcing that a workshop entitled “Oxides of Nitrogen and Sulfur (NO_X/SO_X) Secondary National Ambient Air Quality Standards (NAAQS) Workshop” is being organized by EPA's National Center for Environmental Assessment (NCEA), Office of Research and Development and EPA's Office of Air Quality Planning and Standards (OAQPS), Office of Air and Radiation. The workshop will be held on July 17, 18 and 19, 2007 in Research Triangle Park, North Carolina. The workshop will be open to attendance by interested public observers on a first-come, first-served basis up to the limits of available space.

DATES:

The workshop entitled “Oxides of Nitrogen and Sulfur (NO_X/SO_X) Secondary National Ambient Air Quality Standards (NAAQS) Workshop” will be held on July 17, 18, and 19, 2007.

ADDRESSES:

The workshop will be held at the Carolina Inn in Chapel Hill, North Carolina. An EPA contractor, SAIC, is providing logistical support for the workshop. For further information on the workshop, contact Ms. Kristen Wheeler, SAIC Conference Coordinator, 11251 Roger Bacon Drive, Reston, VA 20190, telephone: [phone]; facsimile: 703-318-4755; e-mail: [e-mail].

FOR FURTHER INFORMATION CONTACT:

Questions regarding information, registration, and logistics for the workshops should be directed to the SAIC Conference Coordinator listed in ADDRESSES above.

Additional questions regarding the secondary NO_X/SO_X NAAQS workshop should be directed to Dr. Tara Greaver, U.S. EPA, NCEA, telephone: [phone]; facsimile: 919-541-1818; e-mail: [e-mail].

SUPPLEMENTARY INFORMATION:

I. Summary of Information About the Workshops

The U.S. Clean Air Act requires that EPA carry out periodic reviews of the national ambient air quality standards (NAAQS) for major “criteria” air pollutants and to revise the NAAQS for a given pollutant, as appropriate. The Agency is in the process of reviewing the secondary (welfare-based) NAAQS for Oxides of Nitrogen (NO_X) and Sulfur Oxides (SO_X). EPA has recognized the merit of integrating the science assessment for these two pollutants, particularly for ecological and welfare effects, based on the important interrelationships for NO_X and SO_X in both their atmospheric chemistry and their effects on the environment. Therefore, EPA is conducting a joint assessment of the secondary NAAQS for NO_X and SO_X.

As part of the NAAQS reviews, the National Center for Environmental Assessment (NCEA) within EPA's Office of Research and Development (ORD) will assess newly available scientific information in Integrated Science Assessment (ISA) documents (formerly known as Air Quality Criteria Documents) that will be supported by more detailed and comprehensive annexes. The assessments in these documents are intended to provide the scientific bases for the reviews of the NAAQS. EPA's Office of Air Quality Planning and Standards (OAQPS) will prepare risk and exposure assessment analyses, as appropriate, drawing upon the scientific evidence summarized in the ISA. Subsequently, the EPA expects to prepare a policy assessment, to be published as an advance notice of proposed rulemaking, that will discuss, in part, the findings of the science and risk/exposure assessments related to the adequacy of the standards and describe a range of options for revising or retaining the NAAQS.

EPA is holding this workshop to inform the Agency's assessment of the scientific evidence for the review of the secondary NAAQS for NO_X and SO_X. The workshop will address various issues involved in the preparation of the draft material for the ISA and annexes. This workshop is planned to help ensure that the ISA provides an up-to-date, state-of-the-art scientific basis for the review of the NAAQS. Workshop discussions will be focused on identifying and integrating scientific evidence that is relevant for future risk and exposure analyses to include in the ISA.

This workshop is being held in conjunction with a workshop entitled “Workshop to Discuss Policy-Relevant Science to Inform EPA's Integrated Plan for the Review of the Secondary Particulate Matter (PM) National Ambient Air Quality Standards (NAAQS)” (see accompanying Notice of Workshop).

Dated: June 14, 2007.

Peter W. Preuss,

Director, National Center for Environmental Assessment.