40 CFR 52.2590: Operating permits.

For any permitting program located in the State, insofar as the permitting threshold provisions in Chapter NR 407 of the Wisconsin Administrative Code concern the treatment of sources of greenhouse gas emissions as major sources for purposes of title V operating permits, EPA approves such provisions only to the extent they require permits for such sources where the source emits or has the potential to emit at least 100,000 tpy CO2 equivalent emissions, as well as 100 tpy on a mass basis, as of July 1, 2011.