Ambient air increments

Ambient air increments. (1) Scope. The ambient air increments apply to all attainment areas of the state. (2) Class I increments. In any area of this state classified under the Act as a class I area, the ambient air increments for PM 10 , PM 2.5 , sulfur dioxide, and nitrogen dioxide may not exceed the following amounts: (a) PM 10 . (am) PM 2.5 . (b) Sulfur dioxide. (c) Nitrogen dioxide. (3) Class II increments. In any area of this state classified under the Act as a class II area, the ambient air increments for PM 10 , PM 2.5 , sulfur dioxide, and nitrogen dioxide may not exceed the following amounts: (a) PM 10 . (am) PM 2.5 . (b) Sulfur dioxide. (c) Nitrogen dioxide. (4) Class III increments. In any area of this state classified under the Act as a class III area, the ambient air increments for PM 10 , PM 2.5 , sulfur dioxide, and nitrogen dioxide may not exceed the following amounts: (a) PM 10 . (am) PM 2.5 . (b) Sulfur dioxide. (c) Nitrogen dioxide. (5) Exception for non-annual concentrations. Notwithstanding subs. (2) (intro.) , (3) (intro.) and (4) (intro.) , the ambient air increment of an air contaminant based on concentrations for any period other than an annual period may be exceeded during one such period per year. (6) Maximum concentration. The maximum allowable concentration of any air contaminant in any attainment area may not exceed a concentration for such contaminant for each period of exposure equal to the maximum concentrations permitted under the primary or secondary air standards in s. NR 404.04 .