CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS (Parts 50–99) > PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS > SUBPART W—Massachusetts (§52.1119 to §52.1169) > 52.1121—Classification of regions.

52.1121—Classification of regions.

The Massachusetts plan was evaluated on the basis of the following classifications:
Air quality control region Pollutant
Particulate matter Sulfur oxides Nitrogen dioxide Carbon monoxide Ozone
Metropolitan Boston Intrastate I I III I I
Merrimack Valley-Southern New Hampshire Interstate I I III III III
Metropolitan Providence Interstate I I III III III
Central Massachusetts Intrastate I II III III III
Hartford-New Haven-Springfield Interstate I I III I I
Berkshire Intrastate II III III III III

Code of Federal Regulations

[37 FR 10872, May 31, 1972, as amended at 39 FR 16346, May 8, 1974; 45 FR 61303, Sept. 16, 1980]