UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX 75 Hawthorne Street San Francisco, CA 94105·3901

OFFICE OF THE REGIONAL ADMINISTRATOR 

## JUN 2 9 2011

The Honorable Neil Abercrombie GovernorofHawaii Executive Chambers, State Capitol Honolulu, Hawaii 96813

Dear Governor Abercrombie:

I am writing to notify you ofthe U.S. Environmental Protection Agency's (EPA's) intention to designate all areas ofHawaii as unclassifiable/attainment for the revised primary National AmbientAir Quality Standard (NAAQS) for nitrogen dioxide (NO

### z )using the boundaries your State recommended in November 2010 or any revised boundaries that you submit in response to this letter. I am also writing to thank you for your State's previous recommendations, to provide you an opportunity to revise these previous recommendations for area boundaries, and to inform you ofour approach for completing the designations for the revised NO

### zNAAQS.

On January 22,2010, the EPA strengthened the health-based NAAQS for NO

### zby setting a new I-hour NOzstandard at the level of 100 parts perbillion (ppb). The EPA also retained the annual NOzstandard of53 ppb. This suite ofstandards will protectpublic health by limiting people's exposures to short-term peak: concentrations of NOzand by limiting community-wide NOzconcentrations to levels below those that have been linked to respiratory-related emergency department visits and hospital admissions in the United States. To determine compliance with the new standard, the EPA established new ambient air monitoring and reporting requirements for NO

### z .In urban areas, monitors are required near major roads
as well as in other locations where maximum concentrations are expected. Additional monitors will be required in some large urban areas to measure the highest concentrations of NOz that occur more broadly across communities.

In our November 2010 letter to Hawaii requesting designation recommendations, the EPA stated that we anticipated designating most areas ofthe country as "unclassifiable," indicating that there are insufficientdata to determine whether or not an area is attaining the revised NOzNAAQS. The EPA believed this approach was appropriate given that: (1) the new near-road monitoring network requirements associated with the revised NOz NAAQS will notbe effective until January 2013, so air qualitydata from these new monitors would not be available to inform initial designations; and (2) the NOzmonitors in the existing NOznetwork do not provide adequate evidence to determine whether or not the new NAAQS is met at otherlocations, especially those closer to NO

### zemission sources such as roadways.

After reviewing all therecommendations we received including Hawaii's, the EPA now intends to designate all areas ofthe country as "unclassifiable/attainment."The EPA is making this change because, based on the most recent airquality data from 2008-2010, all monitored areas in the country meet the 2010 NOz NAAQS. While the EPA acknowledges that the existing NOz monitoring network

Printed on l<l'cycled Paperdoes notprovide adequate evidence to determine whether or not the new NAAQS is met everywhere, there currently is no evidence ofviolations anywhere in the country. Based on this, the EPA believes "unclassifiable/attainment"is the most appropriate designation to use at this time. The EPA intends to redesignate areas, as appropriate, after sufficient air quality data from the new monitoring network are available.

The EPA intends to designate all areas ofHawaii as unclassifiable/attairunentusing the boundaries your State recommended to the EPA last November orany revised boundaries you may provide in response to this letter. As we did in ourNovember 2010 letter, EPArecommends that each state carefully consider the implications ofthe boundaries it selects for its Prevention ofSignificantDeterioration permitting program for new or modified sources to ensure that they are consistent with its objectives for managing air quality deterioration and economic growth.

Ifyour Statehas additional infonnation that you want the EPA to consider with respect to the designations including any revisions to your State'srecommended boundaries, please submititto us by August 29,2011. We are also making the EPA's preliminary designation decisions and supporting documentation available to the general public for review. We are accepting public comments on our preliminary decisions for 30 days after the notice oftheir availability is published in the Federal Register. We will review any infonnation we receive from the state ofHawaii and the general public by these dates. Weplan to promulgatethe final designations by October 31, 2011.

Thank you again for Hawaii's January 2011 recommendations for designations for the new I-hourN02 NAAQS. We look forward to a continued dialogue with you and your staffas we work together to implementthis NAAQS. Should you have any questions, please do nothesitate to call me, orhave your staffcontactDeborah Jordan ofmy staffat (415) 947-8715.
Sincerely,

cc: Gary Gill Deputy Director, Hawaii DOH

Wilfred K. Nagimine Manager, Clean AirBranch, Hawaii DOH