Document RjyrdXoDn5XK8XZNQ7XM5eqY7

and greater than 90% mercury control can be achieved at lignite-fired units at < 3.0 lb/MACF injection rate for units with installed ESPs and using brominated PAC. Yet, MRY's testing data demonstrates that EPA's assumptions that greater than 90% mercury control can be achieved is in error. EPA's Beyond-the-Floor Memorandum and its supporting data also demonstrates that EPA's achievability conclusions around application of AC1 are clearly erroneous. b. EPA finds that no lignite units will need to achieve a removal rate higher than 95% mercury control to meet the New Mercury Limitation of 1.2 lb/TBtu, based on EPA's unitby-unit calculations, and finds MRY would need 87% removal in the Final Rule. Yet, Minnkota's calculations for MRY show that greater than 90% removal would be required when combusting high mercury content lignite based on test results at the mercury inlet. -24- Sierra Club FOIA 2025-EPA-04883 ED_018388_00000327-00076 SC_EVERSPLIT0006385