Document RJ4nr3Kez6KOMGgk0mzMMzb8E

issues exist regarding the installation ofa new baghousc, including the space needed for the large footprint a new ba2house requires. We are unaware of any other available particulate control technology that would be cost effective and satisfy space constraints. Kincaid's operational limitations could also hinder the ability to continuously comply with the fPM standard. Although some units may be able to achieve a rate of 0.010 lb/MMBtu under certain conditions, the Rule requires continuous compliance. Even units that can achieve the limit in ideal conditions may not be able to continuously meet that limit during peak load conditions when they cannot do off-power rapping or maintenance and cleaning of PM controls. During the summer, most units operate at base load and run at high-capacity factors. It may be difficult to maintain optimal operation of control technologies during peak summer conditions unless there are additional outages scheduled for such maintenance, which may not always be feasible. Moreover, the characteristics of coal vary depending on location. Ash content of the coal being fired may impact the ability of units to comply with the f-PM limit, regardless of the effectiveness of the control technologies in place. Other operational factors such as cleaning frequency, operational duration, and maintenance frequency may impact the performance of ESPs and a facility's ability to comply with the proposed limit. These concerns arc exacerbated by the companion requirement to measure compliance using monitors that have not been demonstrated to be reliable. II. CENTS Technology is Not Available the MATS MR requires coal-fired units to implement the revised fPM standard using CEMS, rather than periodic stack testing. As explained above, this requirement is an integral part of the numeric limit itself. Historically, the Kincaid units utilized quarterly PM stack testing to demonstrate compliance with the standard for non-hg metals and eventually achieved MATS Low Emitting EC11.,' (LEE) status for PM. Although Kincaid has a PM CEMS, it is not utilized for MA FS compliance and Kincaid would be faced with upgrading the existing PM CEMS or installing a new one that could be used for compliance with the MATS fPM standard. There arc technological limitations, as well as costs and market limits, that make adoption of CEMS by July 2027 unattainable. PM CEMS does not provide direct measurements; it uses correlation curves to calculate emissions levels. However. the low fPN4 standard in the Rule makes developing this correlation curve "virtually impossible." PCiEN Comments at 22 (citing PM CEMS Technical Memo at 3). Similarly, the QAIQC criterion for CF.MS arc extremely difficult to meet at such low levels. Nee Comments of the Class of '85 Regulatory Response Group on the Proposal on National Emission Standards .ffir Halardous Air Pollutants: Coal- and Oil-Fired Electric. Utility Steam Generating Units Review of the Residual Risk and lechnologv Review, Docket No. EPA-HQ-OAR-2018-0794-5989, at 16 (June 28, 2024) [hereinafter "Class of '85 Comments"]. In fact, at the time of the proposed MATS RTR, no commercially available PM CEMS would have been able to meet the tight confidence and tolerance intervals associated with the low proposed fi'M standard. PEEN Comments at 23 (citing PM CEMS Icehnical Memo at 5). EPA was, thus, forced to address these issues in the final MATS RTR by loosening the QA criterion and correlation procedures. See 89 Fed. Reg. at 38,528-29. However, it has not yet been shown that these changes are enough to address the fundamental issue that PM CEMS has difficulty reliably measuring such low fPM levels due to the error rates of the instrument. See PGEN Comments at 23 (findinp, insurmountable the "uncertainties inherent the in the measurement device" and the "problems associated with relative size of the uncertainty to the limited data range of fPM concentrations and the confidence levels and tolerances"); see also Class of. '85 Comments at 18. And, in reality, units would need to target emissions below 0.010 3 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000161-00003 SC_EVERSPLIT0005932