38 M.R.S. §584-B: Establishment of ambient increments -- Class I regions

In addition to the ambient air quality standards set forth in section 584‑A, any Class I region or part thereof within the State, including those federal lands designated by the Federal Clean Air Act Amendments of 1977, is subject to a maximum allowable increase in concentration of sulfur dioxide, particulate matter and nitrogen oxides over the baseline concentration of that pollutant. An increase shall not be exceeded more than once annually for any period other than an annual period. The maximum allowable increase consists of:

1. PM10. In regards to PM10:

A. An increase in the annual arithmetic mean at any location not to exceed 4 micrograms per cubic meter; and

B. An increase in concentration for any 24-hour period at any location not to exceed 8 micrograms per cubic meter; and

2. Sulfur dioxide. In regards to sulfur dioxide:

A. An increase in the annual arithmetic mean at any location not to exceed 2 micrograms per cubic meter;

B. An increase in concentration for any 24-hour period at any location not to exceed 5 micrograms per cubic meter; and

C. An increase in concentration for any 3-hour period at any location not to exceed 25 micrograms per cubic meter.

3. Nitrogen oxides. In regards to nitrogen oxides:

A. An increase in the annual arithmetic mean at any location not to exceed 2.5 micrograms per cubic meter to be expressed as nitrogen dioxide.