R307. Environmental Quality, Air Quality.
R307-105. General Requirements: Emergency Controls.
R307-105-1. Air Pollution Emergency Episodes.
(1) Determination of an episode and its extent or stage shall be made by the director taking into consideration the levels of pollutant concentrations contained at 40 CFR Section 51.151 and 40 CFR Section 51, Appendix L, and summarized in the table "Air Pollution Episode Criteria":
TABLE AIR POLLUTION EPISODE CRITERIA (values in micrograms/cubic meter unless stated otherwise) | ||||
POLLUTANT | ALERT | WARNING | EMERGENCY | NEVER TO BE EXCEEDED |
Sulfur Dioxide 24-hour average |
800 (0.3 ppm) |
1,600 (0.6 ppm) |
2,100 (0.8 ppm) |
2,620 (1.0 ppm) |
PM10 24-hour average |
350 |
420 |
500 |
600 |
Carbon Monoxide 8-hour average |
17,000 (15 ppm) |
34,000 (30 ppm) |
46,000 (40 ppm) |
57,500 (50 ppm) |
Carbon Monoxide 4-hour average |
|
|
|
86,300 (75 ppm) |
Carbon Monoxide 1-hour average |
|
|
|
144,000 (125 ppm) |
Ozone 1-hour average |
400 (0.2 ppm) |
800 (0.4 ppm) |
1,000 (0.5 ppm) |
|
Ozone 2-hour average |
|
|
|
1,200 (0.6 ppm) |
Nitrogen Dioxide 1-hour average |
1,130 (0.6 ppm) |
2,260 (1.2 ppm) |
3,000 (1.6 ppm) |
3,750 (2.0 ppm) |
Nitrogen Dioxide 24-hour average |
282 (0.15 ppm) |
565 (0.3 ppm) |
750 (0.4 ppm) |
938 (0.5 ppm) |
An air pollution alert, air pollution warning, or air pollution emergency will be declared if any one of the pollutants listed in the table "Air Pollution Episode Criteria" reaches the specified levels at any monitoring site.
In addition to the levels listed for the pollutants in the table "Air Pollution Episode Criteria", meteorological conditions are such that pollutant concentrations can be expected to remain at the levels listed in the table "Air Pollution Episode Criteria" for 12 or more hours or increase, or in the case of ozone, the situation is likely to reoccur within the next 24-hours unless control actions are taken.
ALERT The Alert level is that concentration at which first stage control action is to begin.
WARNING The warning level indicates that air quality is continuing to degrade and that additional control actions are necessary.
EMERGENCY The emergency level indicates that air quality is continuing to degrade toward a level of significant harm to the health of persons and that the most stringent control actions are necessary.
(2) The director shall also take into consideration, to determine an episode and its extent, rate of change of concentration, meteorological forecasts, and the geographical area of the episode, including a consideration of point and area sources of emission, where applicable.
R307-105-2. Emergency Actions.
(1) If an episode is determined to exist, the commissioner, with concurrence of the governor shall:
(a) Make public announcements pertaining to the existence, extent, and area of the episode; and
(b) require corrective measures as necessary to prevent a further deterioration of air quality.
(2) Episode termination shall be announced by the commissioner, with concurrence of the governor, once monitored pollutant concentration data and meteorological forecasts determine the crisis is over.
KEY: air pollution, emergency powers, governor*, air pollution
Date of Last Change: November 4, 2026
Notice of Continuation: May 4, 2022
Authorizing, and Implemented or Interpreted Law: 19-2-112
