UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 10 1200 Sixth Avenue. Suite 900 Seattle. Washington 98101-3140

OFFICE OF THE 

## JUN 1 3 2011 REGIONAL ADMINISTRATOR

TheHonorable C. 

### L. "Butch" Otter Governor ofthe State ofIdaho Post Office Box 83720 Boise, Idaho 83720

Dear Governor Otter:

Thank you for your recommendations on airquality designations for the revised National AmbientAir Quality Standards for lead throughout Idaho. This letter is to notify you ofthe U.S. Environmental Protection Agency's preliminary decision to designate all ofIdaho as unclassifiable/attainment and to inform you ofour approach for completing the designations for the revised lead standards. Reducing levels oflead pollution is an importantpart ofthe EPA's commitment to a clean, healthy environment. Lead exposure can cause a range ofadverse health effects, most notably in children. Exposures to low levels oflead early in lifehave been linked to effects on IQ, learning, memory, and behavior.

On October 15, 2008, the EPA substantially strengthened the health-based or"primary" National Ambient Air Quality Standard bylowerinfitfrom 1.5 micrograms per cubic meter (jJg!m3) a level set in 1978

- to a level of0.15 jJg!m. This stronger standard provides increased protection against adverse health effects associated with exposureto lead in at-risk groups, including children. To provide increased protection against lead-related environmental and other welfare effects, the EPA revised the secondaryNational Ambient Air Quality Standard to be identical in all respects to therevised primary standard. The EPA also determined that the pre-existing ambient lead monitoring network was inadequate for determining whether many areas are meeting the revised lead standards and established new criteria for siting ambient lead monitors and new data collectionrequirements. Monitors meeting the new network siting requirements

were to begin operation January 1, 2010.

Within two years ofpromulgatingnew orrevised National Ambient Air Quality Standards, the Clean AirAct requires the EPAto complete the initial process ofidentifying or designating areas that meet or do not meet an air quality standard. 

### Ifthe Administratorhas insufficient information tomake these designations, the EPA has the authority to extend the designation process byup to

oneyear. In light ofthe new monitoring network, the EPA is completing the lead designations in two rounds. In the first round, published on November 16,2010, the EPA designated as "nonattainment" 16 areas as violating the 2008 Lead National Ambient Air Quality Standards based ondata from the pre-2010 monitoring network. For all other areas, the EPA extended the deadline for designations by up to one year so that data from the newlydeployed monitors canbe considered inmaking appropriate designation decisions. States were given an opportunity to update theirrecommendation letters for those remaining areas for our consideration in the secondround ofdesignations byDecember 15,2010. The EPA intends to complete the second round of lead designations byno later than October 14, 2011.

Consistent with the CleanAirAct, and after carefully considering Idaho's September 30, 2009, recommendation letter and all the associated technical information for the 2008 Lead National Ambient Air Quality Standards, including the most recent air qualitydata from 2008-2010, the EPA is proposing to adopt State's recommended designation and boundary.

Welook forward to a continued dialogue with you and your staffas we work together to implement the 2008 Lead National Ambient Air Quality Standards. Should you have any questions, please do not hesitate to call me, orhave your staffcontact Mr. Steve Bodyat (206) 553-0782.

Sincerely,

# ~C).~ Dennis 

### J. McLerran Regional Administrator

cc: Toni Hardesty Director, Idaho Department ofEnvironmental Quality Martin Bauer Air Program Manager, Idaho Department ofEnvironmental Quality Gina McCarthy Assistant Administrator for Air and Radiation, EPA Steve D. Page Director, Office ofAir Quality Planning and Standards, EPA