(a) For purposes of subsections (b) and (c) of this section:

(1) “Affected unit” means any emissions unit that generates electricity in the state and combusts coal in an amount greater than ten per cent of its total heat input on a rolling twelve-month basis.

(2) “Alternative emissions limit” means a mercury emissions limit established by the Commissioner of Energy and Environmental Protection for an affected unit.

(3) “Calendar quarter” means the period of January first to March thirty-first, inclusive, April first to June thirtieth, inclusive, July first to September thirtieth, inclusive, or October first to December thirty-first, inclusive.

(4) “Inlet conditions” means either: (A) The concentration of mercury in the flue gas exiting the combustion source prior to application of any air pollution control device; or (B) in the case of a fluidized bed combustion unit, the concentration of mercury input to the combustion source based on representative fuel sampling and analysis, as determined by the Commissioner of Energy and Environmental Protection.

(5) “Mercury” means mercury and mercury compounds in either a gaseous or particulate form.

(6) “TBtu” means trillion BTU of heat input.

(7) “Fluidized bed combustion unit” means a combustion unit in which fuel is introduced into a layer of solid particles kept in turbulent motion by air that is forced into the layer from below, resulting in a thorough mixing and intimate contact of the fuel and other reactants.

(b) (1) On and after July 1, 2008, the owner or operator of an affected unit or units shall: (A) Meet an emissions rate of equal to or less than 0.6 pounds of mercury per TBtu, or (B) meet a mercury emissions rate equal to a ninety per cent reduction of mercury from the measured inlet conditions for the affected unit, whichever emissions rate is more readily achievable by such affected unit, as determined by the owner or operator of such affected unit. Compliance with the requirements of this subdivision shall be demonstrated in accordance with the provisions of subdivision (3) of this subsection.

(2) (A) If the owner or operator of any affected unit properly installs and operates control technology designed to achieve the mercury emissions rate requirement of subdivision (1) of this subsection and such technology fails to achieve said emission rate, such owner or operator shall notify the Commissioner of Energy and Environmental Protection of such failure no later than February 1, 2009. Such owner or operator shall submit each quarterly stack test from such affected unit to the Commissioner of Energy and Environmental Protection for evaluation and establishment of an alternative emissions limit for such affected unit based upon the optimized performance of such properly installed and operated control technology. The Commissioner of Energy and Environmental Protection shall establish an alternative emissions limit for any such affected unit no later than April 1, 2010.

(B) Upon the establishment of an alternative emissions limit for an affected unit, pursuant to subparagraph (A) of this subdivision, the Commissioner of Energy and Environmental Protection shall incorporate such alternative emissions limit into the Title V permit for such affected unit. Thereafter, upon any application for renewal of such Title V permit, the Commissioner of Energy and Environmental Protection shall conduct a review of such affected unit’s alternative emissions limit and may impose a more stringent alternative emissions limit based upon any new data regarding the demonstrated control capabilities of the type of control technology installed and operated at such affected unit.

(C) If the owner or operator of any affected unit properly installs and operates control technology designed to achieve the mercury emissions rate requirement established in subdivision (1) of this subsection, but such technology fails to achieve such emissions requirement, and such owner or operator notifies the Commissioner of Energy and Environmental Protection of such failure no later than February 1, 2009, the owner or operator of such affected unit shall demonstrate compliance with the requirements of subdivision (1) of this subsection for the period beginning July 1, 2008, and ending on the date of the issuance of an alternative emissions limit, pursuant to subparagraph (A) of this subdivision, by operating and maintaining such affected unit, including any associated air pollution control equipment, in a manner consistent with good air pollution control practices for the minimization of mercury emissions, as determined by the Commissioner of Energy and Environmental Protection. In determining whether the owner or operator of such affected unit is operating and maintaining such affected unit in a manner consistent with good air pollution control practices for the minimization of mercury emissions, the Commissioner of Energy and Environmental Protection may review the emissions monitoring results and operating and maintenance procedures of such unit and may inspect such affected unit.

(3) (A) Any stack test used to demonstrate compliance with the mercury emissions rate requirements of subdivision (1) of this subsection or used in the establishment or compliance with an alternative emissions limit pursuant to subdivision (2) of this subsection, shall be based on the average of the stack tests conducted during the two most recent calendar quarters for an affected unit and shall be conducted on a calendar quarter basis in accordance with the Environmental Protection Agency’s Method 29 for the determination of metal emissions from stationary sources, as set forth in 40 C.F.R. § part 60, Appendix A, as amended from time to time, or any other alternative method approved by the Environmental Protection Agency or the Commissioner of Energy and Environmental Protection. Such stack tests shall be conducted while combusting coal or coal blends that are representative of the coal or coal blends combusted at such affected unit during the calendar quarter represented by such stack test.

(B) Notwithstanding the provisions of subparagraph (A) of this subdivision, any owner or operator of an affected unit who achieves and maintains compliance with the mercury emissions rate requirement established in subdivision (1) of this subsection for a period of eight consecutive calendar quarters may reduce the frequency of such stack testing for such affected unit from a once-per-calendar-quarter basis to a once-per-year basis. If such annual stack testing demonstrates a failure to comply with the mercury emissions rate requirement established in subdivision (1) of this subsection, such stack testing shall resume on a once-per-calendar-quarter basis, as described in subparagraph (A) of this subdivision.

(C) If the Commissioner of Energy and Environmental Protection determines that continuous emission monitors for mercury in flue gases are commercially available and can perform in accordance with National Institute of Technology Standards, or other methodology approved by the Environmental Protection Agency, the owner or operator of any affected unit shall properly install and operate such continuous emission monitors and shall not be required to conduct stack testing on a calendar quarter basis. When reporting compliance with the mercury emissions rate requirement of subdivision (1) or (2) of this subsection, as applicable, the owner or operator of an affected unit shall use an average of the continuous emission monitor data recorded at such affected unit during the most recent calendar quarter.

(4) The owner or operator of any affected unit shall, for each calendar quarter, report to the Commissioner of Energy and Environmental Protection the results of any stack test or average of the continuous emission monitor data, as applicable, used to demonstrate compliance with the provisions of this subsection. Such reports shall be submitted on such forms as may be prescribed by the Commissioner of Energy and Environmental Protection.

(5) The provisions of this subsection, when implemented by the Commissioner of Energy and Environmental Protection, shall not suspend any underlying procedures or requirements as set forth in the regulations of Connecticut state agencies.

(c) On or before July 1, 2012, the Commissioner of Energy and Environmental Protection shall conduct a review of the mercury emission limits applicable to all affected units in the state. On or after July 1, 2012, the Commissioner of Energy and Environmental Protection may adopt regulations, in accordance with the provisions of chapter 54, imposing mercury emission limits that are more stringent than such emissions requirements provided for in subparagraph (A) or (B) of subdivision (1) of subsection (b) of this section.