GHG Tailoring Rule

The rule (via the preamble only) will allow Step 1 "anyway" sources to commence construction after January 2, 2011 without considering GHG emissions as long as their permit was issued before that date. But Step 2 sources (those who become major after July 1, 2011 due solely to GHG emissions) must "begin actual construction" before 7/1/11. If they have a final permit but don't begin actual construction--which does not include the consideration of having entered into binding contracts--they will have to reopen the permit to include consideration of GHGs. See 75 FR 31527. A discussion of reasoning behind this begins on 75 FR 31593.

The rule establishes a "subject to regulation" definition for GHGs that contains the 100K and 75K tpy thresholds for CO2e. Once these thresholds are surpassed, then the source must determine major source/modification status based on the mass emissions of combined GHGs relative to the standard 100/250 tpy thresholds. In this case, the source may not be major if it has low CO2 emissions and moderate emissions of a high GWP pollutant such as N2O (because each GHG is added based on its mass only, without multiplying by its GWP).

This "subject to regulation" approach somehow facilitates adoption by SIP-approved states such that the rule becomes effective in all states at the same time.

It appears that, in Step 2, a major modification must 1) result in a net CO2e increase greater than 75k tpy and 2) occur at a facility with a CO2e PTE of >100k tpy. CONFIRM