Mississippi Administrative Code
Title 11 - Mississippi Department of Environmental Quality
Part 2 - Bureau of Public Water Supply
Chapter 3 - Mississippi Commission on Environmental Quality, Regulations for the Prevention of Air Pollution Emergency Episodes (Adopted May 8, 1970, Last Amended April 25, 1988)
Rule 11-2-3.3 - Episode Criteria

Universal Citation: MS Code of Rules 11-2-3.3

Current through September 24, 2024

Conditions justifying the proclamation of an air pollution alert, air pollution warning, or air pollution emergency shall be deemed to exist whenever the Director determines that the accumulation of air pollutants in any place is attaining or has attained levels which could if such levels are sustained or exceeded, lead to a substantial threat to the health of persons. In making this determination, the Director will be guided by the following criteria:

A. "Air Pollution Forecast": An internal watch by the Office of Pollution Control shall be actuated by a National Weather Service advisory that Atmospheric Stagnation Advisory is in effect or the equivalent local forecast of stagnant atmospheric condition.

B. "Alert": The Alert level is that concentration of pollutants at which first stage control actions are to begin. An Alert will be declared when any one of the following levels is reached at any monitoring site:

(1) The SO2 level is equal to or greater than 0.3 ppm (800 [MICRO]g/m3) for a 24-hour average.

(2) The PM10 level is equal to or greater than 350 [MICRO]g/m3 for a 24-hour average.

(3) The CO level is equal to or greater than 15 ppm (17 mg/m3) for an 8-hour average.

(4) The ozone (O3) level is equal to or greater than 0.2 ppm (400 [MICRO]g/m3) for 1-hour average.

(5) The NO2 level is equal to or greater than 0.6 ppm (1130 [MICRO]g/m3) for a 1-hour average or 0.15 ppm (282 [MICRO]g/m3) for a 24-hour average.

(6) In addition to the levels listed for the above pollutants, meteorological conditions are such that pollutant concentrations can be expected to remain at the above levels for twelve (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.

C. "Warning": The warning level indicates that air quality is continuing to degrade and that additional control actions are necessary. A warning will be declared when any one of the following levels is reached at any monitoring site:

(1) The SO2 level is equal to or greater than 0.7 ppm (1600 [MICRO]g/m3) for a 24-hour average.

(2) The PM10 level is equal to or greater than 420 [MICRO]g/m3 for a 24-hour average.

(3) The CO level is equal to or greater than 30 ppm (34 mg/m3) for an 8-hour average.

(4) The ozone (O3) level is equal to or greater than 0.4 ppm (800 [MICRO]g/m3) for a 1-hour average.

(5) The NO2 level is equal to or greater than 1.2 ppm (2260 [MICRO]g/m3) for a 1-hour average.

(6) In addition to the levels listed for the above pollutants, meteorological conditions are such that pollutant concentrations can be expected to remain at the above levels for twelve (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.

D. "Emergency": The emergency level indicates that air quality is continuing to degrade to a level that should never be reached and that the most stringent control actions are necessary. An emergency will be declared when any one of the following levels is reached at any monitoring site:

(1) The SO2 level is equal to or greater than 0.8 ppm (2100 [MICRO]g/m3) for a 24-hour average.

(2) The PM10 level is equal to or greater than 500 [MICRO]g/m3 for a 24-hour average.

(3) The CO level is equal to or greater than 40 ppm (46 mg/m3) for an 8-hour average.

(4) The ozone (O3) level is equal to or greater than 0.5 ppm (1000 [MICRO]g/m3) for a 1-hour average.

(5) The NO2 level is equal to or greater than 1.6 ppm (3000 [MICRO]g/m3) for a 1-hour average or 0.4 ppm (750 [MICRO]g/m3) for a 24-hour average.

(6) In addition to the levels listed for the above pollutants, meteorological conditions are such that pollutant concentrations can be expected to remain at the above levels for twelve (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.

E. "Termination": Once declared, any status reached by application of these criteria will remain in effect until the criteria for that level are no longer met. At such time, the next lower status will be assumed.

Miss. Code Ann. §§ 49-2-9(1)(b), 49-17-17, 49-2-1, et seq. and 49-17-1, et seq.

Disclaimer: These regulations may not be the most recent version. Mississippi may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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