Wisconsin Administrative Code
Department of Natural Resources
NR 400-499 - Environmental Protection - Air Pollution Control
Chapter NR 493 - Air pollution episode levels and episode emission control action programs
Section NR 493.03 - Episode levels
Current through August 26, 2024
(1) AIR EPISODE ADVISORY. The department may issue an Air Pollution Episode advisory to the general public if any air contaminant or combination of air contaminants reaches the respective level of concentration specified in Table 1 at any monitoring site.
(2) AIR EPISODE LEVELS. The department shall declare an Air Pollution Episode Level at the "Alert", "Warning" or "Emergency" stage if any air contaminant or combination of air contaminants reaches the respective level of concentration specified in Table 1 at any monitoring site and if meteorological conditions are such that the concentrations of the air contaminant can be expected to remain at or above that level for 12 or more hours, or in the case of ozone, to recur the following day at the same or a higher level, unless control actions are taken.
Table 1
Episode Stage Criteria For Air Contaminants
|
Air Contaminants |
Sampling |
Averaging |
Alert |
Warning |
Emergency |
|
Period |
Period |
||||
|
Particulate Matter |
24-hours |
Block average |
375 µg/m3 |
625 µg/m3 |
875 µg/m3 |
|
Sulfur Dioxide |
1-hour |
Any hour |
1870 µg/m3 |
3730 µg/m3 |
4990 µg/m3 |
|
(0.70 ppm) |
(1.40 ppm) |
(1.90 ppm) |
|||
|
24-hours |
Continuous running |
800 µg/m3 |
1600 µg/m3 |
2100 µg/m3 |
|
|
average |
(0.30 ppm) |
(0.60 ppm) |
(0.80 ppm) |
||
|
Product of Particulate Matter and Sulfur Dioxide |
24-hours |
Block average |
65,000 (µg/m3)2 |
261,000 (µg/m3)2 |
393,000 (µg/m3)2 |
|
Carbon Monoxide |
8-hours |
Continuous running average |
17 mg/m3 (15 ppm) |
34 mg/m3 (30 ppm) |
46 mg/m3 (40 ppm) |
|
Ozone (for volatile |
1-hour |
Any hour |
0.20 ppm |
0.40 ppm |
0.50 ppm |
|
organic compounds) |
(400 µg/m3) |
(800 µg/m3) |
(1000 µg/m3) |
||
|
Nitrogen Dioxide |
1-hour |
Any hour |
1130 µg/m3 |
2260 µg/m3 |
3000 µg/m3 |
|
(0.60 ppm) |
(1.20 ppm) |
(1.60 ppm) |
