Arizona Administrative Code › Title 18 - ENVIRONMENTAL QUALITY › Chapter 2 - DEPARTMENT OF ENVIRONMENTAL - QUALITY AIR POLLUTION CONTROL › Article 2 - AMBIENT AIR QUALITY STANDARDS; AREA DESIGNATIONS; CLASSIFICATIONS › Section R18-2-220 - Air Pollution Emergency Episodes

Current through Register Vol. 30, No. 28, July 12, 2024
A.
				Procedures shall be implemented by the Director in order to prevent the
				occurrence of ambient air pollutant concentrations which would cause
				significant harm to the health of persons, as specified in subsection (B)(4).
				The procedures and actions required for each stage are described in the
				Department's "Procedures for Prevention of Emergency Episodes," amended as of
				August 2018 (and no future edition), which is incorporated herein by reference
				and on file with the Department.
B.
				The following stages are identified by air quality criteria in order to provide
				for sequential emissions reductions, public notification and increased
				Department monitoring and forecast responsibilities. The declaration of any
				stage, and the area of the state affected, shall be based on air quality
				measurements and meteorological analysis and forecast.
1. A Stage I air pollution alert shall be
				declared when any of the alert level concentrations listed in subsection (B)(4)
				are exceeded at any monitoring site and when meteorological conditions indicate
				that there will be a continuance or recurrence of alert level concentrations
				for the same pollutant during the subsequent 24-hour period. If, 48 hours after
				an alert has been initially declared, air pollution concentrations and
				meteorological conditions do not improve, the warning stage control actions
				shall be implemented but no warning shall be declared, unless air quality has
				deteriorated to the extent described in subsection (B)(2).
2. A Stage II air pollution warning shall be
				declared when any of the warning level concentrations listed in subsection
				(B)(4) are exceeded at any monitoring site and when meteorological conditions
				indicate that there will be a continuance or recurrence of concentrations of
				the same pollutant exceeding the warning level during the subsequent 24-hour
				period. If, 48 hours after a warning has been initially declared, air pollution
				concentrations and meteorological conditions do not improve, the emergency
				stage shall be declared and its control actions implemented.
3. A Stage III air pollution emergency shall
				be declared when any of the emergency level concentrations listed in subsection
				(B)(4) are exceeded at any monitoring site and when meteorological conditions
				indicate that there will be a continuance or recurrence of concentrations of
				the same pollutant exceeding the emergency level during the subsequent 24-hour
				period.
4. Summary of emergency
				episode and significant harm levels:
Pollutant
Averaging Time
Alert
Warning
Emergency
Significant Harm
Carbon monoxide (mg/
							 m3)
1-hr
--
--
--
144
4-hr
--
--
--
86.3
8-hr
17
34
46
57.5
Nitrogen dioxide
							 (µg/m3)
1-hr
1,130
2,260
3,000
3,750
24-hr
282
565
750
938
Ozone (ppm)
1-hr
.2
.4
.5
.6
PM2.5
							 (µg/m3)
24-hr
140.5
210.5
280.5
350.5
PM10
							 (µg/m3)
24-hr
350
420
500
600
Sulfur dioxide
							 (µg/m3)
24-hr
800
1,600
2,100
2,620