UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 


REGION 10 


1200 Sixth Avenue, Suite 900 

Seattle, WA 98101-3140 

UUN 14 2DiC REGIONAL ADMINISTRATOR 

Toni Hardesty, Director 

Department of Environmental Quality 

State of Idaho 

1410 North Hilton 

Boise Idaho, 83706 

Dear Director Hardesty: 

Thank you for your recommendations on air quality designations for the revised National 

Ambient Air Quality Standards (NAAQS) for lead throughout Idaho. Reducing levels of lead 

pollution is an important part of EPA's commitment to a clean, healthy environment. Lead 

exposure can cause a range of adverse health effects, most notably in children. Exposures to low 

levels of lead early in life have been linked to effects on IQ, learning, memory and behavior. 

This letter is to notify you of the U.S. Environmental Protection Agency's (EPA's) response to 

Idaho's designation recommendations, and to inform you of our approach for completing the 

designations for the revised lead NAAQS. 

On October 15,2008, EPA substantially strengthened NAAQS for lead. The new 

standards, set at 0.15 micrograms per cubic meter (!lg/m3), are 10 times tighter than the previous 

standards. In conjunction with strengthening the lead NAAQS, EPA also established new 

criteria for siting ambient lead monitors. The pre-existing ambient lead monitoring network was 

inadequate for determining whether many areas are meeting the revised lead NAAQS. Monitors 

meeting the new network siting requirements were to begin operation January 1,2010. 

The Clean Air Act (CAA) requires EPA to complete the initial designation process within 

two years of promUlgating a new or revised N AAQS. If the Administrator has insufficient 

information to make these designations, EPA has the authority to extend the designation process 

by up to one year. In light of the new monitoring network which will generate additional 

information in the upcoming year, EPA intends to complete the lead designations in two rounds. 

In the first round, to be completed by October, 15, 2010, EPA is designating as "nonattainment" 

any area that is violating the 2008 lead NAAQS based on data from the pre-201O monitoring 

network. For all other areas, EPA is extending the deadline for designations by up to one year so 

that data from the newly deployed monitors can be considered in making appropriate designation 

decisions. EPA will complete the second round of lead designations no later than October 15, 

2011. 

We have reviewed Idaho's September 30,2009, recommendation letter on air quality 

designations and all the associated technical information for the 2008 lead NAAQS, including, if 

available, the most recent air quality data from 2007-2009. However, EPA is not intending to 

complete the initial area designations for your state at this time. Instead, EPA intends to 

designate all areas in your state by no later than October 15, 2011, in the second round of lead 

designations. If you would like to submit updated recommendations for your areas for our 

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consideration in the second round of designations, we request that you do so by December 15, 

2010. For the second round of designations, we will notify all states and tribes of our 

preliminary responses to their recommendations by no later than June 17,2011. 

We look forward to a continued dialogue with you and your staff as we work together to 

implement the 20081ead NAAQS. Should you have any questions, please do not hesitate to call 

me, or have your staff contact Steve Body in the Office of Air, Waste and Toxies at 

206-553-0782. 

Sincerely, 

C<;;;;J-q, 


Dennis 1. McLerran 

Regional Administrator 

Enclosure 

cc: 	 Martin Bauer, Air Quality Division Administrator 

Gina McCarthy, Assistant Administrator for Air and Radiation 

Steven D. Page, Director, Office of Air Quality Planning and Standards 

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