Section 60.45Da - Alternative standards for combined nitrogen oxides (NO[X]) and carbon monoxide (CO)(a) The owner or operator of an affected facility that commenced construction, reconstruction, or modification after May 3, 2011 as alternate to meeting the applicable NOX emissions limits specified in § 60.44Da may elect to meet the applicable standards for combined NOX and CO specified in paragraph (b) of this section.(b) On and after the date on which the initial performance test is completed or required to be completed under § 60.8 no owner or operator of an affected facility that commenced construction, reconstruction, or modification after May 3, 2011, shall cause to be discharged into the atmosphere from that affected facility any gases that contain NOX (expressed as NO2) plus CO in excess of the applicable emissions limit specified in paragraphs (b)(1) through (3) of this section as determined on a 30-boiler operating day rolling average basis. (1) For an affected facility which commenced construction or reconstruction, any gases that contain NOX plus CO in excess of either: (i) 140 ng/J (1.1 lb/MWh) gross energy output; or(ii) 150 ng/J (1.2 lb/MWh) net energy output.(2) For an affected facility which commenced construction or reconstruction and that burns 75 percent or more coal refuse (by heat input) on a 12-month rolling average basis, any gases that contain NOX plus CO in excess of either: (i) 160 ng/J (1.3 lb/MWh) gross energy output; or(ii) 170 ng/J (1.4 lb/MWh) net energy output.(3) For an affected facility which commenced modification, any gases that contain NOX plus CO in excess of 190 ng/J (1.5 lb/MWh) gross energy output. 77 FR 9453 , Feb. 16, 2012