40 CFR § 76.6 - NO emission limitations for Group 2 boilers.

---
identifier: "/us/cfr/t40/s76.6"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 76.6 - NO emission limitations for Group 2 boilers."
title_number: 40
title_name: "Protection of Environment"
section_number: "76.6"
section_name: "NO emission limitations for Group 2 boilers."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "76"
part_name: "ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7601 and 7651"
regulatory_source: "60 FR 18761, Apr. 13, 1995, unless otherwise noted."
cfr_part: "76"
---


# 76.6 NO emission limitations for Group 2 boilers.

(a) Beginning January 1, 2000 or, for a unit subject to section 409(b) of the Act, the date on which the unit is required to meet Acid Rain emission reduction requirements for SO<sub>2</sub>, the owner or operator of a Group 2, coal-fired boiler with a cell burner boiler, cyclone boiler, a wet bottom boiler, or a vertically fired boiler shall not discharge, or allow to be discharged, emissions of NO<sub>X</sub> to the atmosphere in excess of the following limits, except as provided in §§ 76.10 or 76.11:

(1) 0.68 lb/mmBtu of heat input on an annual average basis for cell burner boilers. The NO<sub>X</sub> emission control technology on which the emission limitation is based is plug-in combustion controls or non-plug-in combustion controls. Except as provided in § 76.5(d), the owner or operator of a unit with a cell burner boiler that installs non-plug-in combustion controls shall comply with the emission limitation applicable to cell burner boilers.

(2) 0.86 lb/mmBtu of heat input on an annual average basis for cyclone boilers with a Maximum Continuous Steam Flow at 100% of Load of greater than 1060, in thousands of lb/hr. The NO<sub>X</sub> emission control technology on which the emission limitation is based is natural gas reburning or selective catalytic reduction.

(3) 0.84 lb/mmBtu of heat input on an annual average basis for wet bottom boilers, with a Maximum Continuous Steam Flow at 100% of Load of greater than 450, in thousands of lb/hr. The NO<sub>X</sub> emission control technology on which the emission limitation is based is natural gas reburning or selective catalytic reduction.

(4) 0.80 lb/mmBtu of heat input on an annual average basis for vertically fired boilers. The NO<sub>X</sub> emission control technology on which the emission limitation is based is combustion controls.

(b) The owner or operator shall determine the annual average NO<sub>X</sub> emission rate, in lb/mmBtu, using the methods and procedures specified in part 75 of this chapter.

[62 FR 67162, Dec. 19, 1996; 62 FR 3464, Jan. 23, 1997; 62 FR 32040, June 12, 1997; 64 FR 55838, Oct. 15, 1999]