Iowa Admin. Code r. 567-26.2 - Episode criteria

(1) Evaluation. Conditions justifying the proclamation of an air pollution alert, air pollution warning or air pollution emergency shall be deemed to exist whenever the commission or the director determines that the meteorological conditions are such that the accumulation of air contaminants in any place is reaching, or has reached, levels which could, if sustained or exceeded, lead to a substantial threat to the health of persons.

Air pollution forecast. Initial consideration of air pollution episode activities will be activated by receipt from the National Weather Service of an air pollution forecast. Receipt of such a forecast shall be the basis for activities such as, but not limited to, increased monitoring of the air contaminants in the area involved.

(2) Declaration. In making determinations for the declaration of an air pollution episode condition, the commission or the director will be guided by the criteria stated in the following paragraphs.

a. Air pollution alert. An alert will be declared when any one of the following levels is reached at any monitoring site, and when meteorological conditions are such that the contaminant concentrations can be expected to remain at those levels for 12 or more hours, or increase, unless control actions are taken.

(1) Sulfur dioxide-800 micrograms per cubic meter (0.3 ppm), 24-hour average.

(2) Particulate matter (PM₁₀)-350 micrograms per cubic meter, 24-hour average.

(3) Carbon monoxide-17 milligrams per cubic meter (15 ppm), eight-hour average.

(4) Ozone-400 micrograms per cubic meter (0.2 ppm), one-hour average.

(5) Nitrogen dioxide-1,130 micrograms per cubic meter (0.6 ppm), one-hour average, or 282 micrograms per cubic meter (0.15 ppm), 24-hour average.

b. Air pollution warning. A warning will be declared when any one of the following levels is reached at any monitoring site and when meteorological conditions are such that the contaminant concentrations can be expected to remain at those levels for 12 or more hours or increase, unless control actions are taken.

(1) Sulfur dioxide-1,600 micrograms per cubic meter (0.6 ppm), 24-hour average.

(2) Particulate matter (PM₁₀)-420 micrograms per cubic meter, 24-hour average.

(3) Carbon monoxide-34 milligrams per cubic meter (30 ppm), eight-hour average.

(4) Ozone-800 micrograms per cubic meter (0.4 ppm), one-hour average.

(5) Nitrogen dioxide-2,260 micrograms per cubic meter (1.2 ppm), one-hour average, or 565 micrograms per cubic meter (0.3 ppm), 24-hour average.

c. Air pollution emergency. An emergency will be declared when any one of the following levels is reached at any monitoring site, and when meteorological conditions are such that this condition can be expected to continue for 12 or more hours.

(1) Sulfur dioxide-2,100 micrograms per cubic meter (0.8 ppm), 24-hour average.

(2) Particulate matter (PM₁₀)-500 micrograms per cubic meter, 24-hour average.

(3) Carbon monoxide-46 milligrams per cubic meter (40 ppm), eight-hour average.

(4) Ozone-1,000 micrograms per cubic meter (0.5 ppm), one-hour average.

(5) Nitrogen dioxide-3,000 micrograms per cubic meter (1.6 ppm), one-hour average or 750 micrograms per cubic meter (0.4 ppm), 24-hour average.

d. 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. As meteorological factors and air contaminants change, an appropriate change in episode level will be declared.

Notes

Iowa Admin. Code r. 567-26.2

Amended by IAB February 15, 2017/Volume XXXIX, Number 17, effective 3/22/2017