Federal Register: PROPOSED RULES Air quality implementation plans; approval and promulgation; various States; air quality planning purposes; designation of areas: [40 CFR Parts 52 and 81]

ENVIRONMENTAL PROTECTION AGENCY

Environmental Protection Agency

CFR Citation: 40 CFR Parts 52 and 81

EPA ID: [EPA-R09-OAR-2005-AZ-0006; FRL-8029-3]

NOTICE: PROPOSED RULES

ACTION: Air quality implementation plans; approval and promulgation; various States; air quality planning purposes; designation of areas:

DOCUMENT ACTION: Proposed rule.

SUBJECT CATEGORY: AGENCY: Environmental Protection Agency (EPA).

DATES: Any comments on this proposal must arrive by March 10, 2006.

DOCUMENT SUMMARY: EPA is proposing to determine that the Ajo moderate PM-10 nonattainment area in Arizona has attained the National Ambient Air Quality Standards (NAAQS) for particulate matter with an aerodynamic diameter less than or equal to a nominal 10 micrometers
(PM10). This determination is based upon monitored air quality data for the PM10 NAAQS during the years 20022004. EPA also finds that the Ajo area has continued to attain the PM10 NAAQS since 2004. Based on this determination, EPA is also proposing to determine that certain Clean Air Act requirements are not applicable for so long as the Ajo area continues to attain the PM10 NAAQS.

SUMMARY: Arizona,

SUPPLEMENTAL INFORMATION

This proposal addresses the determination that the Ajo moderate PM10 nonattainment area in Arizona has attained the National Ambient Air Quality Standards (NAAQS) for particulate matter with an aerodynamic diameter less than or equal to a nominal 10 micrometers (PM10). This determination is based upon monitored air quality data for the PM10 NAAQS during the years 20022004. This proposal also addresses the determination that, because the Ajo area continues to attain the PM10 NAAQS, certain attainment demonstration requirements, along with other related requirements of the CAA, are not applicable to the Ajo area. In the Rules and Regulations section of this Federal Register, we are taking direct final action to make these determinations because we believe this action is not controversial. If we receive adverse comments, however, we will publish a timely withdrawal of the direct final rule and address the comments in subsequent action based on this proposed rule. We do not plan to open a second comment period, so anyone interested in commenting should do so at this time. If we do not receive comments, no further activity is planned.

For all the reasons explained in the parallel direct final notice, we propose to determine that the Ajo moderate PM10 nonattainment area in Arizona has attained the National Ambient Air Quality Standards (NAAQS) for particulate matter with an aerodynamic diameter less than or equal to a nominal 10 micrometers
(PM10). A determination of attainment is not a redesignation to attainment under CAA section 107(d)(3) because we have not yet approved a maintenance plan as required under section 175(A) of the CAA or determined that the area has met the other CAA requirements for redesignation.\1\
\1\ On December 20, 2005, EPA proposed revisions to the NAAQS for particulate matter. See 71 FR 2620, January 17, 2006. The proposed revisions address two categories of particulate matter: Fine particles which are particles 2.5 micrometers in diameter and smaller; and ``inhalable coarse'' particles, which are particles between 2.5 and 10 micrometers (PM102.5). Upon
finalization of a primary 24hour standard for PM102.5, EPA proposes to revoke the current 24hour PM10 standard in all areas of the country except in areas where there is at least one monitor located in an urbanized area (as defined by the U.S. Bureau of the Census) with a minimum population of 100,000 that violates the current 24hour PM10 standard based on the most recent three years of data. In addition, EPA proposes to revoke the current annual PM10 standard upon finalization of a primary 24hour standard for PM102.5.

We further propose to determine that, because the Ajo area has continued to attain the PM10 NAAQS, certain attainment demonstration requirements, along with other related requirements of the CAA, are not applicable to the Ajo area. For further information on this proposal and the rationale underlying our proposed action, please see the direct final action.

Dated: January 24, 2006.
Wayne Nastri,
Regional Administrator, Region 9.
[FR Doc. 061173 Filed 2706; 8:45 am]
BILLING CODE 656050P

FOR FURTHER INFORMATION CONTACT Wienke Tax, Office of Air Planning, U.S. Environmental Protection Agency, Region 9, (520) 6221622, email:
tax.wienke@epa.gov.