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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX

75 Hawthorne Street

San Francisco, CA 94105-3901

AUG2 02014

Henry R. Darwin, Director

Arizona Department of Environmental Quality

1110 West Washington Street

Phoenix, Af ona 85007

Djwin:

Thank you for your letter ofJune 20, 2014, in which you requested that the Environmental

Protection Agency (EPA) delay its proposed redesignation ofthe Hayden area to nonattainment

for the 2008 national ambient air quality standard (NAAQS) for lead (Pb). Iii support of your

request, you: 1) noted that ADEQ’s Globe Highway has not measured a violation of the Pb

NAAQS since 2012, when ASARCO installed controls; 2) raised concerns about the

representativeness of the data from the ASARCO monitors; and 3) suggested that a state

implementation plan (SIP) for the control of lead would duplicate the requirements of the sulfur

dioxide (SO 2)plan, which is due in April of 2015 and which you believe will reduce Ph

concentrations in the area. Regional Administrator Blumenfeld has asked that I respond on his

behalf.

The EPA commends the 2012 installation of pollution control equipment on the anode furnaces

at the ASARCO facility and understands that the equipment might have resulted in a reduction of

ambient Pb concentrations, as measured at the Globe Highway monitor. However, based on

violations recorded in 2012 and on the form ofthe Pb NAAQS (i.e., three consecutive calendar

years without a violation are required before an area can be considered to be attaining the

standard), the monitor continues to violate the Pb NAAQS.

As you observed, the Clean Air Act provides the Administrator with broad authority to consider

air quality data or any other air quality-related considerations she deems appropriate in

determining whether to redesignate an area to nonattainment. Accordingly, in addition to

considering the data from ADEQ’s Globe Highway monitor, we also reviewed data gathered by

the more extensive monitoring network recently installed by ASARCO. Data recorded by the

ASARCO monitors indicate that the Globe Highway site may not be capturing maximum

ambient concentrations of Pb in the Hayden area, and that the area is experiencing ongoing

violations ofthe Pb NAAQS. While data used as the basis for determining whether an area is

violating a NAAQS must meet specific requirements contained within 40 CFR Part 58, any

available monitoring data may be used to improve our understanding of what is occurring in an

area. We also note that the ASARCO monitors were established for multiple purposes, including

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comparison to the NAAQS. The EPA’s analysis ofthe ASARCO data and the findings from our

recent audit of the monitors give us confidence that these supplementary data provide a more

complete picture of air quality in the Hayden area and that it is appropriate to include these

supplementary data in our deliberations regarding redesignation.

Finally, while the controls required under the Hayden SO2 SIP could result in reductions in

ambient concentrations of Pb, the EPA has not received information that quantifies the benefits

of these future controls. In and of itself, an SO2 SIP is not designed to control Pb emissions and is

not required to ensure that the reductions are sufficient to achieve attainment of the Pb NAAQS.

Accordingly, the EPA does not agree that relying on the SO2plan to resolve the Pb problem will

ensure expeditious attainment of the Pb standard.

Exposure to Pb is a serious health concern. It causes a range of adverse health effects, most

notably in children. Exposures to low levels of Pb early in life have been linked to effects on IQ,

learning, memory, and behavior. Depending on the level ol exposure. Pb can aclverseh aliect the

nervous system. kidney function. immune system. reproductive and developmental systems and

the cardiovascular system. The available information indicates the general public is being

exposed to Pb concentrations in excess of the NAAQS and no information has been presented

that demonstrates the S02 SIP will ensure sufficient, permanent reductions in Ph concentrations.

We therefore determined that it is appropriate to initiate the process for evaluating emissions and

developing control strategies by redesignating the area to nonattainment for the 2008 Pb

NAAQS. We look forward to working with you on the development of this plan. If you have any

questions, please call me.

Sincerely,

Deborah JordaW

Director, Air l3ivision

Cc: Eric Massey, Air Director, Arizona Department of Environmental Quality (via email)

Michael Sundblom, Director, Pinal County Air Quality Control District (via email)