UNITEDSTATES ENVIRONMENTAL PROTECTION AGENCY REGION 6 1445 ROSS AVENUE, SUITE 1200 DALLAS, TX 75202-2733 

### JUN 1 

### 4 2010

Ms. Peggy Hatch Secretary Louisiana Department ofEnvironmental Quality Post Office Box 4301 Baton Rouge, Louisiana 70821

Dear Secretary Hatch:

Thankyou for your recommendations on air quality designations for the revised National Ambient Air Quality Standards (NAAQS) for lead throughout Louisiana. Reducing levels of lead pollution is an importantpart ofthe u.S. Environmental Protection Agency's (EPA) commitmentto a clean, healthy environment. Lead exposure can cause a range ofadverse health effects, most notably in children. Exposures to low levels oflead early in life have been linked to effects on IQ, learning, memory and behavior. This letter is to notify you ofEPA's response to Louisiana's designationrecommendations, and to inform you ofour approach for completing the designations for the revised lead NAAQS.

On October 15, 2008, EPA substantially strengthenedNAAQS for lead. The new standards, set at 0.15 micrograms per cubic meter (ug/rrr'), are 10 times tighterthan the previous standards. In conjunction with strengthening the lead NAAQS, EPA also established new criteriafor 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 requires EPA to complete the initial designationprocess within two years ofpromulgating a new or revised NAAQS. Ifthe Administratorhas insufficient information to make these designations, EPA has the authority to extend the designationprocess by up to one year. In light ofthe 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 completedby 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 oflead designations no later than October 15, 2011.

We have reviewed Louisiana's October 15,2009, recommendation letter on air quality designations and all the associatedtechnical 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 no later than October 15,2011, in the second round oflead

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### Letter to Secretary Hatch Page 2
designations. Ifyou would like to submitupdatedrecommendations for your areas for our consideration in the second round ofdesignations, we request that you do so by December 15, 2010. For the secondround ofdesignations, we will notify all states and tribes ofour preliminary responses to their recommendations no later than June 17, 2011.

We look forward to a continued dialogue with you and your staffas we work together to implement the 2008 lead NAAQS. Ifyou have any questions, please call me at (214) 665-2100, or your staffmay call Mr. Emad Shahin ofmy staffat (214) 665-6717.

cc: Mr. Michael Vince Administrator, Air Quality Assessment Division Louisiana Department ofEnvironmental Quality