Q68. 40 CFR §98.33(a)(3)(iii) indicates that “For units that combust municipal solid waste (MSW) and that produce steam, use Equation C-2c of this section”. However, Table C-1 ..indicates that the emission factor for Municipal Solid Waste fuel is “Allowed only for Units that do not generate steam and use Tier 1”.

The footnote is intended to reinforce that Tier 1 cannot be used for units that combust MSW and generate steam. For units that combust MSW and generate steam, Tier 2 and the respective default values from Table C-1 may be used for a unit of any size if the use of Tier 4 is not required.

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