06- 096 C.M.R. ch. 100, § 159 - Significant impact

"Significant impact" means the contribution for any regulated pollutants which is equal to or greater than, or may reasonably be expected to be equal to or greater than, the levels shown below for the respective averaging times:

Class II area significant impact levels

Pollutant	Annual	24-Hr	8-Hr	3-Hr	1-Hr
SO2	1. 0 µg/m3	5 µg/m3	25 µg/m3
PM10	1. 0 µg/m3	5 µg/m3
TSP	1. 0 µg/m3	5 µg/m3
NO2	1. 0 µg/m3
CO	500 µg/m3	2000 µg/m3
PM2.5	0. 3 µg/m3	1. 2 µg/m3

Class I area significant impact levels

Pollutant	Annual	24-Hr	8-Hr	3-Hr	1-Hr
PM2.5	0. 06 µg/m3	0. 07 µg/m3

Notes

06- 096 C.M.R. ch. 100, § 159