40 C.F.R. § 81.31
The Metropolitan Providence Interstate Air Quality Control Region (Rhode Island-Massachusetts) consists of the territorial area encompassed by the boundaries of the following jurisdictions or described area (including the territorial area of all municipalities (as defined in section 302(f) of the Clean Air Act, 42 U.S.C. 1857h(f) ) geographically located within the outermost boundaries of the area so delimited):
The Entire State of Rhode Island.
In the State of Massachusetts: Cities-Attleboro, Fall River, Acushnet, Barnstable, Bellingham, Berkley, Bourne, Brewster, Carver, Chatham, Chilmark, Dartmouth, Dennis, Dighton, Eastham, Edgartown, Fairhaven, Falmouth, Foxborough, Franklin, Freetown, Gay Head, Gosnold, Halifax, Harwich, Kingston, Lakeville, Mansfield, Marion, Mashpee, New Bedford, Taunton.
TOWNSHIPS- Middleborough, Milford, Nantucket, North Attleborough, Mattapoisett, Medway, Norton, Oak Bluffs, Orleans, Plainville, Plymouth, Plympton, Provincetown, Raynham, Rehoboth, Rochester, Sandwich, Seekonk, Somerset, Swansea, Tisbury, Truro, Wareham, Wellfleet, Westport, West Tisbury, Wrentham, Yarmouth.
40 C.F.R. §81.31