This final rule will address the Agency's Residual Risk and Technology review (RTR) of the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Portland Cement Manufacturing. The Portland Cement Manufacturing NESHAP, subpart LLL, initially was promulgated pursuant to section 112(d) of the Clean Air Act (CAA) in 1999. The EPA promulgated the current version of the rule on 9/9/10, with amendments on 2/12/13 and 7/27/15. The NESHAP established emission limitations and work practice requirements based on maximum achievable control technology (MACT) for controlling emissions of hazardous air pollutants (HAP) from kilns, clinker coolers, raw material dryers and finish mills, as well as clinker piles, storage bins, conveying systems, bagging systems, bulk loading and unloading systems. The HAP emitted from kilns and clinker coolers include particulate matter metals, including mercury, volatile organic compounds; dioxin/furans and hydrogen chloride. This action will implement the residual risk review requirements of CAA section 112(f)(2) and the technology review requirements of CAA section 112(d)(6). The statute directs the EPA to promulgate emission standards under CAA 112(f)(2) if such standards are required to provide an ample margin of safety to protect public health or to prevent, taking relevant factors into account, an adverse environmental effect. Any such standards are to be promulgated within 8 years after promulgation of MACT standards under CAA section 112(d). CAA section 112(d)(6) requires the EPA to review and revise the MACT standards as necessary, taking into account developments in practices, processes, and control technologies, no less often than every 8 years. Pursuant to an agreed upon extension of the original consent decree, the EPA is obligated to complete this final action by 7/15/18.