N.H. Code Admin. R. Env-A 606.03
(a) The owner or operator of a source shall demonstrate, using the air pollution dispersion modeling impact analysis required in this part, that the source will not:
(b) A source shall be considered to cause or contribute to a violation of a NAAQS when such source’s contribution would exceed the significance levels at any locality that does not or would not meet the applicable national standard, as shown in table 606-1 below:
Table 606-1: NAAQS Significance Levels
Pollutant
Averaging Time and Significance Levels
Annual
24-hour
8-hour
3-hour
1-hour
SO2
1.0 ug/m3
5 ug/m3
25 ug/m3
PM10
1.0 ug/m3
5 ug/m3
PM2.5
0.3 ug/m3
1.2 ug/m3
NO2
1.0 ug/m3
CO
0.5 mg/m3
2 mg/m3
Source. #10175, eff 9-1-12; ss by #13510, eff 12-17-22