U.S. Code of Federal Regulations
Regulations most recently checked for updates: Aug 27, 2025
The following table presents the latest dates by which the national standards are to be attained. The dates reflect the information presented in New Hampshire's plan.
| Air quality control region | SO | PM | NO | CO | O | |
|---|---|---|---|---|---|---|
| Primary | Secondary | |||||
| NH portion Andoscoggin Valley Interstate AQCR 107 | a | b | a | a | a | a |
| Central NH Intrastate AQCR 149 | a | b | a | a | a | a |
| NH portion Merrimack Valley-Southern NH Interstate 121: | ||||||
| Belknap County | a | b | a | a | a | a |
| Sullivan County | a | b | a | a | a | a |
| Cheshire County | a | b | a | a | a | d |
| Portmouth-Dover-Rochester area (See 40 CFR 81.330) | a | b | a | a | a | e |
| NH portion Boston-Lawrence-Worcester area (See 40 CFR 81.330) | a | b | a | a | a | f |
| Manchester area (See 40 CFR 81.330) | a | b | a | a | a | c |
a. Air quality levels presently below primary standards or area is unclassifiable.
b. Air quality levels presently below secondary standards or area is unclassifiable.
c. November 15, 1993.
d. November 15, 1995.
e. November 15, 1999.
f. November 15, 2007.
