---
kind: "section"
citation: "40 C.F.R. § 98.183"
title: "40"
number: "98.183"
heading: "Calculating GHG emissions."
url: "https://uscodex.org/cfr/40/98.183"
---

# §98.183. Calculating GHG emissions.


You must calculate and report the annual process CO2 emissions from each smelting furnace using the procedure in paragraphs [(a)](#a) and [(b)](#b) of this section.

- (a) For each smelting furnace that meets the conditions specified in § [98.33(b)(4)(ii)](/cfr/40/98.33.md?p=b-4-ii) or [(b)(4)(iii)](/cfr/40/98.33.md?p=b-4-iii), you must calculate and report combined process and combustion CO2 emissions by operating and maintaining a CEMS to measure CO2 emissions according to the Tier 4 Calculation Methodology specified in [§ 98.33(a)(4)](/cfr/40/98.33.md?p=a-4) and all associated requirements for Tier 4 in [subpart C](/cfr/40/subpartC.md) of this part (General Stationary Fuel Combustion Sources).
- (b) For each smelting furnace that is not subject to the requirements in [paragraph (a)](#a) of this section, calculate and report the process and combustion CO2 emissions from the smelting furnace by using the procedure in either paragraph [(b)(1)](#b-1) or [(b)(2)](#b-2) of this section.
  - (1) Calculate and report under this subpart the combined process and combustion CO2 emissions by operating and maintaining a CEMS to measure CO2 emissions according to the Tier 4 Calculation Methodology specified in [§ 98.33(a)(4)](/cfr/40/98.33.md?p=a-4) and all associated requirements for Tier 4 in [subpart C](/cfr/40/subpartC.md) of this part (General Stationary Fuel Combustion Sources).
  - (2) Calculate and report process and combustion CO2 emissions separately using the procedures specified in [paragraphs (b)(2)(i) through (b)(2)(iii)](#b-2-i..b-2-iii) of this section.
    - (i) For each smelting furnace, determine the annual mass of carbon in each carbon-containing material, other than fuel, that is fed, charged, or otherwise introduced into the smelting furnace and estimate annual process CO2 emissions using Equation R-1 of this section. Carbon-containing materials include carbonaceous reducing agents. If you document that a specific material contributes less than 1 percent of the total carbon into the process, you do not have to include the material in your calculation using Equation R-1 of this section.
    - (ii) Determine the combined annual process CO2 emissions from the smelting furnaces at your facility using Equation R-2 of this section.
    - (iii) Calculate and report under [subpart C](/cfr/40/subpartC.md) of this part (General Stationary Fuel Combustion Sources) the combustion CO2 emissions from the smelting furnaces according to the applicable requirements in subpart C.

## Notes

### Authority

Authority: 42 U.S.C. 7401-7671q.

### Source

Source: 74 FR 56374, Oct. 30, 2009, unless otherwise noted.