AIR EMISSIONS REGULATIONS:

Air Quality Status	In attainment (AQMD includes all of Modoc County) EPA's Nonattainment Areas
Major Source Threshold	250 tons of any criteria pollutant triggers PSD
Minor Source Permitting Exemption	None
Minor Source Treatment	BACT
Emergency Generating Limits	None

DE MINIMIS EXEMPTIONS (Must meet 1298)

None.

MINOR SOURCE PERMITTING

The district has never permitted a minor source electric generating facility. There are no specific rules established, but the district would require BACT based on CARB's guidance. Sample BACT for control of NOx from turbines and internal combustion engines is as follows:

Size of Unit	Level of Control (ppm)
>3 MW	9
3-12 MW simple cycle	2.5
3-12 MW combined cycle	5
12-50 MW simple cycle	2.5
12-50 MW combined cycle	5
IC Engines	9

TREATMENT OF EMERGENCY ENGINES

An emergency engine would likely be exempted from permitting, but no requirements have been established. CARB Air Toxic Control Measures for Stationary Compression Engines apply (see the CA state page for more information).