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40 CFR § 75.13 - Specific provisions for monitoring CO emissions.

---
identifier: "/us/cfr/t40/s75.13"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 75.13 - Specific provisions for monitoring CO emissions."
title_number: 40
title_name: "Protection of Environment"
section_number: "75.13"
section_name: "Specific provisions for monitoring CO emissions."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "75"
part_name: "CONTINUOUS EMISSION MONITORING"
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. 7401-7671q and 7651k note."
regulatory_source: "58 FR 3701, Jan. 11, 1993, unless otherwise noted."
cfr_part: "75"
---

# 75.13 Specific provisions for monitoring CO emissions.

(a) *CO*<sub>2</sub> *continuous emission monitoring system.* If the owner or operator chooses to use the continuous emission monitoring method, then the owner or operator shall meet the general operating requirements in § 75.10 for a CO<sub>2</sub> continuous emission monitoring system and flow monitoring system for each affected unit. The owner or operator shall comply with the applicable provisions specified in §§ 75.11(a) through (e) or § 75.16, except that the phrase “CO<sub>2</sub> continuous emission monitoring system” shall apply rather than “SO<sub>2</sub> continuous emission monitoring system,” the phrase “CO<sub>2</sub> concentration” shall apply rather than “SO<sub>2</sub> concentration,” the term “maximum potential concentration of CO<sub>2</sub>” shall apply rather than “maximum potential concentration of SO<sub>2</sub>,” and the phrase “CO<sub>2</sub> mass emissions” shall apply rather than “SO<sub>2</sub> mass emissions.”

(b) *Determination of CO*<sub>2</sub> *emissions using appendix G to this part.* If the owner or operator chooses to use the appendix G method, then the owner or operator shall follow the procedures in appendix G to this part for estimating daily CO<sub>2</sub> mass emissions based on the measured carbon content of the fuel and the amount of fuel combusted. For units with wet flue gas desulfurization systems or other add-on emissions controls generating CO<sub>2</sub>, the owner or operator shall use the procedures in appendix G to this part to estimate both combustion-related emissions based on the measured carbon content of the fuel and the amount of fuel combusted and sorbent-related emissions based on the amount of sorbent injected. The owner or operator shall calculate daily, quarterly, and annual CO<sub>2</sub> mass emissions (in tons) in accordance with the procedures in appendix G to this part.

(c) *Determination of CO*<sub>2</sub> *mass emissions using an O*<sub>2</sub> *monitor according to appendix F to this part.* If the owner or operator chooses to use the appendix F method, then the owner or operator shall determine hourly CO<sub>2</sub> concentration and mass emissions with a flow monitoring system; a continuous O<sub>2</sub> concentration monitor; fuel F and F<sub>c</sub> factors; and, where O<sub>2</sub> concentration is measured on a dry basis (or where Equation F-14b in appendix F to this part is used to determine CO<sub>2</sub> concentration), either, a continuous moisture monitoring system, as specified in § 75.11(b)(2), or a fuel-specific default moisture percentage (if applicable), as defined in § 75.11(b)(1); and by using the methods and procedures specified in appendix F to this part. For units using a common stack, multiple stack, or bypass stack, the owner or operator may use the provisions of § 75.16, except that the phrase “CO<sub>2</sub> continuous emission monitoring system” shall apply rather than “SO<sub>2</sub> continuous emission monitoring system,” the term “maximum potential concentration of CO<sub>2</sub>” shall apply rather than “maximum potential concentration of SO<sub>2</sub>,” and the phrase “CO<sub>2</sub> mass emissions” shall apply rather than “SO<sub>2</sub> mass emissions.”

(d) *Determination of CO*<sub>2</sub> *mass emissions from low mass emissions units.* The owner or operator of a unit that qualifies as a low mass emissions unit under § 75.19(a) and (b) shall comply with one of the following:

(1) Meet the general operating requirements in § 75.10 for a CO<sub>2</sub> continuous emission monitoring system and flow monitoring system;

(2) Meet the requirements specified in paragraph (b) or (c) of this section for use of the methods in appendix G or F to this part, respectively; or

(3) Use the low mass emissions excepted methodology in § 75.19(c) for estimating hourly CO<sub>2</sub> mass emissions, if applicable under § 75.19(a) and (b). If this option is selected for CO<sub>2</sub>, the LME methodology must also be used for NO<sub>X</sub> and SO<sub>2</sub> when these parameters are required to be monitored by applicable program(s).

[58 FR 3701, Jan. 11, 1993, as amended at 60 FR 26521, May 17, 1995; 63 FR 57499, Oct. 27, 1998; 64 FR 28591, May 26, 1999; 67 FR 40423, June 12, 2002; 73 FR 4343, Jan. 24, 2008]