MARIPOSA COUNTY AIR POLLUTION CONTROL DISTRICT

RULE 414 - SOURCES IMPACTING CLASS I AREAS

1. The Air Pollution Control Officer shall accept, and consider comments offered by the Federal Land Manager of any lands contained within a Class I area impacted by a proposed major facility or major modification. If the Federal Land Manager demonstrates that the emissions from a proposed major facility or major modification would have an adverse impact on the air quality-related values (including visit- bility) of any federal mandatory Class I areas, notwith- standing that the change in air quality resulting from emissions from such facility or modification would not cause or contribute to concentrations which would exceed the maximum allowable increase for a Class I area, and if the Air Pollution Control Officer concurs with such demonstration, then he shall deny the Authority to Construct.
   
   
2. If the applicant demonstrates, and the affected Federal Land Manager of a Class I area concurs, that the emissions from a proposed major facility or major modification would have no adverse impact on the air quality-related values (including visibility) of such federal mandatory Class I area, and providing that all District Rules and Regulations are otherwise met, the Air Pollution Control Officer may issue an Authority to Construct with such emission limitations as he may deem necessary to assure that emissions of sulfur dioxide and particulate matter would not exceed the following maximum allowable increases over the baseline concentrations:
   
   

   ZONE POLLUTANT		Maximum Allowable Increase (micrograms per cubic meter)
   Particulate Matter:		Class I
   	Annual Geometric Mean	19
   	24-hour Maximum	37
   Sulfur Dioxide:
   	Annual Arithmetic Mean	20
   	24-hour Maximum	91
   	3-hour Maximum	325

3. If the applicant demonstrates, and the Air Resources Board, and affected Class I Federal Land Manager concur, that the proposed major facility or major modification cannot be constructed in compliance with Section B. above, as it relates to sulfur dioxide increments and that such facility or modification would not adversely affect air quality-related values (including visibility) of any affected federal mandatory Class I area, and provided that the District Rules and Regulations are otherwise met, the Air Pollution Control Officer may issue an Authority to Construct with such emission limitations as he may deem necessary to assure that emissions of sulfur dioxide would not exceed the following maximum allowable increase over the baseline concentration:

ZONE POLLUTANT		Maximum Allowable Increase (micrograms per cubic meter)
		Class I
Sulfur Dioxide:
	24-hour Maximum	62
	3-hour Maximum	221

The emission limitation contained in the Authority to Construct under this Section shall also prohibit the exceedance of the maximum allowable increases contained in Rule 413 for period of exposure of 24 hours or less for more than 18 days, not necessarily consecutive, during any annual period.