UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
 

REGION IX
 

75 Hawthorne Street
 

San Francisco, CA 94105·3901
 

OFFICE OF THE 

REGIONAL ADMINISTRATOR 

JUN 14 2011 

The Honorable Mary Resvaloso 

Chairwoman 

Torres Martinez Desert Cahuilla Indians 

P.O. Box 1160 

Thermal, California 92274 

Dear Chairwoman Resvaloso: 

Thank you for your Tribe's recommendation regarding the air quality designation for the revised 

National Ambient Air Quality Standards for lead, submitted by Jonathan Chapman on behalf of the 

Torres Martinez Desert Cahuilla Indians. This letter is to notify you of the U.S. Environmental 

Protection Agency's (EPA's) preliminary decision to designate the Torres Martinez Desert Cahuilla 

reservation as unclassifiable/attainment, and to inform you of our approach for completing the 

designations for the revised lead standard. 

Reducing levels of lead pollution is an important part of the 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 ofIead early in life have 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 for lead by lowering it from 1.5 micrograms per cubic meter (~g/m3) - a 

level set in 1978 - to a level of 0.15 ~glm3. This stronger standard provides increased protection against 

adverse health effects associated with exposure to lead in at-risk groups, including children. To provide 

increased protection against lead-related environmental and other welfare effects, the EPA revised the 

secondary National Ambient Air Quality Standard to be identical in all respects to the revised primary 

standards. 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 collection requirements. Monitors meeting 

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

Within two years of promulgating new or revised National Ambient Air Quality Standards, th Clean 

Air Act requires the EPA to complete the initial process of identifying or designating areas that meet or 

do not meet an air quality standard. If the Administrator has insufficient infonnation to make these 

designations, the EPA has the authority to extend the designation process by up to one year. In light of 

the new monitoring network, the EPA is completing the lead designations in two rounds. In the first 

round, completed on November 16, 2010, the EPA designated as "nonattainment" 16 areas as violating 

Prinrt!d on Recyclt!d Paper 
the 2008 Lead National Ambient Air Quality Standards based on data from the pre-201 0 monitoring 

network. For all other areas, the EPA extended 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. 

Tribes were given an opportunity to update their recommendation letters for those remaining areas for 

our consideration in the second round of designations by December 15,20 IO. The EPA intends to 

complete the second round of lead designations no later than October 14, 2011. 

Consistent with the Clean Air Act, and after carefully considering the Torres Martinez Desert Cahuilla 

Indians' recommendation letter and all the associated technical information for the 2008 Lead National 

Ambient Air Quality Standards, including the most recent air quality data from 2008-2010, the EPA is 

proposing to designate the Torres Martinez Desert Cahuilla Indian reservation as 

unclassifiable/attainment. The EPA uses this designation for initial designations to identify areas that 

have data indicating attainment, or where there is no evidence of a violation. 

If you have additional information that the EPA should consider with respect to our proposed 

modification to your designation recommendation, please submit it to us by August 15, 2011. The EPA's 

preliminary designation decisions and supporting documentation will be made available to the general 

public for review. We will be accepting comments through August 15,2011. We will review any 

information we receive from the Torres Martinez Desert Cahuilla Indians, the State of California, and 

the general public by this date, and we plan to promulgate the second round of final designations by 

October 14, 2011. 

We look forward to a continued dialogue with you and your staff as 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, or have your staff contact Associate Air Division Director Colleen McKaughan at 

520-498-0118. 

cc: Gerardo Bojorquez 

Environmental Specialist