Rules and Regulations. Proposed rule

Agency: Environmental Protection Agency (EPA)
Action: Proposed rule
Citation: FR Doc. 06-1173 · EPA-R09-OAR-2005-AZ-0006; FRL-8029-3 · 40 CFR 52, 81

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 (PM ¹⁰ ). This determination is based upon monitored air quality data for the PM ¹⁰ NAAQS during the years 2002-2004. EPA also finds that the Ajo area has continued to attain the PM ¹⁰ 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 PM ¹⁰ NAAQS.

Dates

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

Supplementary Information

This proposal addresses the determination 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 (PM ¹⁰ ). This determination is based upon monitored air quality data for the PM ¹⁰ NAAQS during the years 2002-2004. This proposal also addresses the determination that, because the Ajo area continues to attain the PM ¹⁰ 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 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 (PM ¹⁰ ). 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 (PM ^10-2.5 ). Upon finalization of a primary 24-hour standard for PM ^10-2.5 , EPA proposes to revoke the current 24-hour PM ¹⁰ 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 24-hour PM ¹⁰ standard based on the most recent three years of data. In addition, EPA proposes to revoke the current annual PM ¹⁰ standard upon finalization of a primary 24-hour standard for PM ^10-2.5 . We further propose to determine that, because the Ajo area has continued to attain the PM ¹⁰ 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. 06-1173 Filed 2-7-06; 8:45 am]