Section 336.2503. Mercury emission standards for electric generating units.

(1) Unless the federal MATS is an applicable requirement, beginning April 16, 2015, an affected existing EGU as defined in this part shall meet either of the following, unless projects  have been approved under subrule (2) or (3) of this rule:

(a)   A minimum of 90% reduction from baseline input mercury levels as determined under R 336.2505 on a 12-month rolling average basis as determined at the end of each calendar month.

(b)   An output-based emission standard of 0.008 pounds of mercury per gigawatts- hour on a 12-month rolling average basis as determined at the end of each calendar month.

(2)   As an alternative to the provisions in subrule (1) of this rule, a multi-pollutant compliance demonstration project for an existing EGU may be implemented. This shall at minimum include all of the following:

(a)     The owner or operator of an existing EGU shall submit a multi-pollutant compliance demonstration project plan not later than the end of June before the applicable compliance year. The plan shall include, at a minimum, a description of the multi-pollutant emission controls, multi-pollutant emissions data, multi-pollutant emissions reductions, and compliance schedules.

(b)     The plan shall be subject to the review and approval of the department. Department approval of an alternative mercury emission standard shall be based on the information submitted. To be approved, the multi-pollutant compliance demonstration project plan must establish a minimum of 75% reduction from baseline input mercury levels on a 12-month rolling average basis as determined at the end of each calendar month for the individual EGU. If the department determines the plan does not meet the definition of a multi-pollutant compliance demonstration project, then the department will make a determination on the plan in writing. If the plan is unacceptable, the department shall state the reasons for disapproval and require the existing EGU  to comply with the provisions of subrule (1) of this rule.

(3)   An existing EGU that is limited to emit 9 pounds (144 ounces) of mercury per 12-month rolling time period as determined at the end of each calendar month as a VLME unit shall be excluded from the provisions in subrule (1) of this rule, provided an alternative compliance demonstration project meeting the criteria of R 336.2513 is implemented. A maximum of 3 existing EGUs at the same stationary source may be VLME units.

(4)    Compliance with the provisions of subrules (1) and (3) of this rule may be demonstrated using either of the following methods:

(a)   Compliance on an EGU-by-EGU basis.

(b)    Stationary source-wide averaging or source-wide pooling of emissions across affected EGUs under control of the same operator or owner.

(5)    New EGUs shall not cause or allow the emission of mercury in excess of the maximum allowable emission rate based on the application of best available control technology for mercury. At a minimum, a new EGU shall comply with 90% reduction from input mercury levels on a 12-month rolling average basis as determined at the end of each calendar month or an output-based emission standard of 0.008 pounds of mercury per gigawatt-hour on a 12-month rolling average basis as determined at the end of each calendar month.

(6)   By January 16 of the applicable compliance year, the owner or operator for each affected EGU shall submit and certify a compliance demonstration notification to demonstrate compliance with subrules (1), (2), (3), or (5) of this rule. The compliance demonstration notification shall be submitted according to R 336.2509. Adjustments may be made to the compliance method under subrules (1), (2), and (3), and for source-wide averaging or source-wide pooling of EGUs under subrule (4) of this rule up to April 15 before beginning the applicable compliance year via addendum to a certified compliance demonstration notification.

(7)   The installation of mercury emission controls shall not be considered a physical change or a change in the method of operation at an affected EGU if the addition of the

mercury emission control will not result in emissions that exceed any emission rate otherwise allowable under state or federal requirements.

History: 2009 AACS; 2013 AACS.