Federal Register: December 12, 2008 (Volume 73, Number 240)

DOCID: fr12de08-71 FR Doc E8-29347

ENVIRONMENTAL PROTECTION AGENCY

Environmental Protection Agency

FRL ID: [FRL-8750-6]

NOTICE: NOTICES

DOCID: fr12de08-71

ACTION: Environmental Impact Statements; Availability, etc.:

DOCUMENT ACTION: Notice of Availability.

SUBJECT CATEGORY:

Integrated Science Assessment for Oxides of Nitrogen and Sulfur-- Environmental Criteria

DATES: The document will be available on or about December 12, 2008.

DOCUMENT SUMMARY:

The U.S. Environmental Protection Agency is announcing the availability of a final document entitled, ``Integrated Science Assessment for Oxides of Nitrogen and SulfurEcological Criteria,'' and the supplementary annexes (EPA/600/R08/082F). The document was prepared by the National Center for Environmental Assessment (NCEA) within EPA's Office of Research and Development as part of the review of the secondary National Ambient Air Quality Standards (NAAQS) for oxides of nitrogen and sulfur. EPA's secondary NAAQS are based on ecological and welfare effects.

SUMMARY:

Integrated Science Assessment for Oxides of Nitrogen and Sulfur - Environmental Criteria; Document Availability,

SUPPLEMENTAL INFORMATION

Section 108(a) of the Clean Air Act directs the Administrator to identify certain pollutants that ``may reasonably be anticipated to endanger public health and welfare'' and to issue air quality criteria for them. These 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. * * *'' Under section 109 of the Act, EPA is then to establish NAAQS for each pollutant for which EPA has issued criteria. Section 109(d) of the Act requires subsequent periodic review and, if appropriate, revision of existing air quality criteria to reflect advances in scientific knowledge on the effects of the pollutant on public health and welfare. EPA is also to revise the NAAQS, if appropriate, based on the revised air quality criteria.

Oxides of nitrogen and sulfur are two of six principal (or ``criteria'') pollutants for which EPA has established air quality criteria and NAAQS. EPA periodically reviews the scientific basis for these standards by preparing an Integrated Science Assessment (ISA) (formerly called an Air Quality Criteria Document). The ISA and supplementary annexes, in conjunction with additional technical and policy assessments, provide the scientific basis for EPA decisions on the adequacy of a current NAAQS and the appropriateness of new or revised standards. The Clean Air Scientific Advisory Committee [[Page 75717]]
(CASAC), an independent science advisory committee established pursuant to section 109 of the Clean Air Act and part of the EPA's Science Advisory Board (SAB), provides independent scientific advice on NAAQS matters, including advice on EPA's draft ISAs.

EPA formally initiated its current review of the criteria for oxides of nitrogen and sulfur in December 2005 (70 FR 73236) and May 2006 (71 FR 28023) respectively, requesting the submission of recent scientific information on specified topics. In the initial stages of the criteria reviews, EPA recognized the merit of integrating the science assessment for these two pollutants due to their combined effects on atmospheric chemistry, deposition processes, and environmentrelated public welfare effects. In July 2007 (72 FR 34004), EPA held a workshop to discuss, with invited scientific experts, initial draft materials prepared in the development of the ISA and supplementary annexes for oxides of nitrogen and sulfur. EPA's ``Draft Plan for Review of the Secondary National Ambient Air Quality Standards for Nitrogen Dioxide and Sulfur Dioxide'' was made available in September 2007 for public comment and was discussed by the Clean Air Scientific Advisory Committee (CASAC) via a publicly accessible teleconference consultation on October 30, 2007 (72 FR 57568). EPA made its Draft Plan available on EPA's Web site: http://www.epa.gov/ttn/ naaqs/standards/no2so2sec/cr_pd.html. The draft ``Integrated Science Assessment for Oxides of Nitrogen and SulfurEnvironmental Criteria; First External Review Draft'' was released for review on December 21, 2007 (72 FR 72719). The CASAC reviewed the first draft document at a public peer review meeting on April 23, 2008. EPA addressed comments from the CASAC and the public in the second external review draft document, ``Integrated Science Assessment for Oxides of Nitrogen and SulfurEnvironmental Criteria; Second External Review Draft,'' which was released for public comment on August 12, 2008 (72 FR 46908). The second draft was reviewed by the CASAC at a public meeting on October 23, 2008. EPA has considered comments by CASAC and by the public in preparing this final ISA.

Dated: December 4, 2008.
Rebecca Clark,
Acting Director, National Center for Environmental Assessment. [FR Doc. E829347 Filed 121108; 8:45 am]
BILLING CODE 656050P

FOR FURTHER INFORMATION CONTACT

For technical information, contact Tara Greaver, Ph.D., NCEA [telephone: 9195412435; facsimile: 919541 5078; or email: greaver.tara@epa.gov].