Document 5wp2NrwXo877yQ1OdDnB58vz

Presidential Exemption Request GVEA Healy Power Plant March 31, 2025 regulatory mercury process monitor has taken four years and as of March 2025 is not yet complete. Once the process monitor is consistently operational, the next steps GVEA anticipates needing to complete in order to meet the new MATS mercury emission limit will include installation, controls, and programming to tie the existing carbon injection skid to the mercury process monitor so emissions levels can be managed at the low standard. Healy Unit 1 does not have a mercury emissions control system nor a mercury process monitor and uses annual source testing as its compliance demonstration method. In order to meet the new MATS mercury emissions limit on Healy Unit 1, GVEA expects that it will need to budget for, engineer, procure, install, and commission a mercury control system on Unit 1. Given the experience with Unit 2, GVEA further expects that it will need to install a mercury process monitor for real-time emissions data and establish the controls and programming to equip the system to respond rapidly to real-time mercury emissions levels and maintain emissions consistently below the new standard. GVEA's experience installing and maintaining comparable equipment elsewhere makes it clear to GVEA that it is not technically feasible for GVEA to complete this work by July 6, 2027. The additional time provided by the Presidential Exemption would allow GVEA a reasonable time frame to design and install control systems suited to the unique conditions of the Healy Power Plant. GVEA appreciates your consideration of this request. Please contact me at nmknietecivea corn or (907)458-4557 with any questions. Sincerely, Naomi J. Morton Knight GVEA Chief Power Supply Officer Attachments Page 8 of 8 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000057-00008 SC_EVERSPLIT0005608