Release of Final Document Related to the Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Sulfur

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of Availability.

SUMMARY:

The Office of Air Quality Planning and Standards (OAQPS) of EPA is announcing the availability of a document titled, Policy Assessment for the Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Sulfur (January 14, 2011 version) (Policy Assessment). The Policy Assessment contains staff analyses of the scientific bases for alternative policy options for consideration by the Agency prior to rulemaking.

DATES:

This version of Policy Assessment will be available on or about January 14, 2011; a final version is expected to be released around the end of January.

ADDRESSES:

The document will be available primarily via the Internet at the following Web site: http://www.epa.gov/ttn/naaqs/standards/no2so2sec/cr_pa.html.

FOR FURTHER INFORMATION CONTACT:

For questions related to this document, please contact Dr. Richard Scheffe, Office of Air Quality Planning and Standards (Mail code C304-02), U.S. Environmental Protection Agency, Research Triangle Park, NC 27711; e-mail: scheffe.rich@epa.gov telephone: 919-541-4650; fax: 919-541-2357.

SUPPLEMENTARY INFORMATION:

Under section 108(a) of the Clean Air Act (CAA), the Administrator identifies and lists certain pollutants which “cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare.” The EPA then issues air quality criteria for these listed pollutants, which are commonly referred to as “criteria pollutants.” The air quality criteria are to “accurately reflect the latest scientific knowledge useful in indicating the kind and extent of all identifiable effects on public health or welfare which may be expected from the presence of [a] pollutant in the ambient air, in varying quantities.” Under section 109 of the CAA, EPA establishes primary (health-based) and secondary (welfare-based) national ambient air quality standards (NAAQS) for pollutants for which air quality criteria are issued. Section 109(d) of the CAA requires periodic review and, if appropriate, revision of existing air quality criteria. The revised air quality criteria reflect advances in scientific knowledge on the effects of the pollutant on public health or welfare. The EPA is also required to periodically review and revise the NAAQS, if appropriate, based on the revised criteria.

Presently, EPA is reviewing the secondary NAAQS for oxides of nitrogen and sulfur. The document announced today, Policy Assessment for the Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Sulfur (January 14, 2011 version), contains staff analyses of the scientific bases for alternative policy options for consideration by the Agency prior to rulemaking. This document, which builds upon the historical “Staff Paper,” will serve to “bridge the gap” between the available scientific information and the judgments required of the Administrator in determining whether it is appropriate to retain or revise the standards. The current and potential alternative standards for oxides of nitrogen and sulfur are considered in terms of the basic elements of the NAAQS: Indicator, averaging time, form, and level. The Policy Assessment builds upon information presented in the Integrated Science Assessment for Oxides of Nitrogen and Sulfur—Ecological Criteria: Final report (ISA, EPA EPA/600/R-08/082F, December 2008) and the quantitative risk and exposure assessment document (REA)—Risk and Exposure Assessment for Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur (EPA-452/R-09-008a and EPA-452/R-09-008b; September 2009).

A first draft Policy Assessment (EPA-452/P-10-006) was released in March 2010 to facilitate discussion with the Clean Air Scientific Advisory Committee (CASAC) at an April 1-2, 2010 meeting on the overall structure, areas of focus, and level of detail to be included in the Policy Assessment (75 FR 10479-10481, March 2010). CASAC's comments on the first draft Policy Assessment encouraged the development of a document focused on the key policy-relevant issues that draws from and is not repetitive of information in the ISA and REA. These comments were considered in developing a second draft Policy Assessment (EPA 452/P-10-008, September 2010). The EPA presented an overview of the second draft Policy Assessment at a CASAC meeting on October 6-7, 2010 (75 FR 54871-54872).

CASAC (EPA-CASAC-11-003) and public comments on the second draft Policy Assessment were considered by EPA staff in developing this version of the final Policy Assessment which is available through the Agency's Technology Transfer Network (TTN) Web site at http://www.epa.gov/ttn/naaqs/standards/no2so2sec/cr_pa.html. CASAC has requested a February 15-16, 2011, meeting to review EPA's final Policy Assessment. EPA is releasing this January 14, 2011, version of the final Policy Assessment at this time, prior to final document production, to provide sufficient time for CASAC review of the document in advance of this meeting. EPA will continue with final document production, including final reference checks and document formatting, and release the final version of this Policy Assessment around the end of January.