EPA has taken final action to approve in part, and conditionally approve in part, portions of the Tennessee State Implementation Plan (SIP) submission related to compliance with the 2008 Lead national ambient air quality standards (NAAQS). The Clean Air Act (CAA) requires that each state adopt and submit a SIP for the implementation, maintenance, and enforcement of each NAAQS promulgated by EPA, which is commonly referred to as an “infrastructure” SIP. In 2009, TDEC certified in its infrastructure submission that the Tennessee SIP contains provisions that ensure the 2008 Lead NAAQS are implemented, enforced, and maintained in Tennessee. EPA has made the determination that TDEC’s infrastructure submission meets the infrastructure requirements for the 2008 Lead NAAQS. This approval will be effective July 18, 2013.

As background, in 1978, EPA promulgated primary and secondary NAAQS for Lead; both primary and secondary standards were set at a level of 1.5 µg/m3, measured as Lead in total suspended particulate matter (Pb-TSP), not to be exceeded by the maximum arithmetic mean concentration averaged over a calendar quarter. In 2008, EPA issued a final rule to revise the primary and secondary Lead NAAQS. The revised primary and secondary Lead NAAQS were revised to 0.15 µg/m3. By statute, revised SIPs are to be submitted by states within 3 years after promulgation of a new or revised NAAQS. Tennessee provided its infrastructure submission for the 2008 Lead NAAQS on October 19, 2009.

On March 28, 2012, Tennessee submitted a letter of commitment to EPA to adopt specific enforceable measures to address the current deficiencies in the Tennessee SIP. On March 20, 2013, EPA proposed to approve the majority of Tennessee’s 2009 infrastructure submission and proposed in the alternative to conditionally approve some portions of the submission.

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