South Carolina Code of Regulations › Chapter 61 - DEPARTMENT OF HEALTH AND ENVIRONMENTAL CONTROL › Subchapter 61-62 - Air Pollution Control Regulations and Standards › Subchapter 61-62.3 - Air Pollution Episodes › Section 61-62.3.I - EPISODE CRITERIA

Current through Register Vol. 48, No. 6, June 28, 2024
Conditions justifying the proclamation of any stage of an air
				  pollution episode shall be deemed to exist whenever the Commissioner 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
				  substantial threat to the health of persons. The appropriate episode stage will
				  be declared on a regional basis, as dictated by air quality monitoring. Adverse
				  air quality need not be regionwide to trigger control actions; the appropriate
				  episode stage will be declared for an entire Air Quality Control Region when
				  any monitoring site within the region records ambient air quality in excess of
				  that designated in the criteria. In making this determination, the Commissioner
				  will be guided by the criteria listed below:
1. FORECAST--This level will normally be
				activated when an Air Stagnation Advisory (ASA) is issued for any part of South
				Carolina by the Columbia Forecast Office of the National Weather Service. If
				continuous air monitoring equipment indicates an upward trend in pollutant
				concentrations, the Commissioner may request that the National Weather Service
				issue an ASA, even though meteorological factors do not appear critical. In the
				absence of an ASA, the Commissioner may, at his discretion, declare this level
				when it is in the best interest of public health and welfare.
2. WATCH--This level will be activated when
				continuous air quality monitoring indicates that one of the following pollutant
				concentrations has been reached:
PM10 - 350 micrograms per cubic meter
				  (<<mu>>g/m3), twenty-four (24)-hour
				  average;
SO2 - 400
				  <<mu>>g/m3 (0.15 parts per million
				  (ppm)), twenty-four (24)-hour average; or
O3 (Ozone) - 400
				  <<mu>>g/m3 (0.2 ppm), one (1)-hour
				  average;
and meteorological conditions are such that the pollutant
				  concentrations can be expected to remain at the above levels for twelve (12)
				  hours or more, or increase, or in the case of ozone, the situation is likely to
				  recur within the next twenty-four (24) hours unless control actions are
				  taken.
3. ALERT--This level
				indicates that air quality is continuing to deteriorate and that additional
				control actions are necessary. An alert will be declared when monitoring
				indicates that one of the following pollutant concentrations has been reached:
PM10 - 420
				  <<mu>>g/m3, twenty-four (24)-hour
				  average;
SO2 - 800
				  <<mu>>g/m3 (0.3 ppm), twenty-four
				  (24)-hour average; or
O3 (Ozone) - 800
				  <<mu>>g/m3 (0.4 ppm), one (1)-hour
				  average;
and meteorological conditions are such that pollutant
				  concentrations can be expected to remain at the above levels for twelve (12)
				  hours or more, or increase, or in the case of ozone, the situation is likely to
				  recur within the next twenty-four (24) hours unless control actions are
				  taken.
4. EMERGENCY - The
				primary objective of this plan is to prevent this level from ever being
				reached; however, should this level be reached the most stringent control
				actions are necessary. An emergency will be declared when monitoring indicates
				that one of the following pollutant concentrations has been reached:
PM10 - 500
				  µg/m3, twenty-four (24)-hour average;
SO2 - 1600
				  µg/m3 (0.6 ppm), twenty-four (24)-hour average;
				  or
O3 (Ozone) - 1000
				  ìg/m3 (0.5 ppm), one (1)-hour average;
and meteorological conditions are such that this condition
				  can be expected to continue for twelve (12) hours or more, or increase, or in
				  the case of ozone, the situation is likely to recur within the next twenty-four
				  (24) hours unless control actions are taken.
5. TERMINATION--Once declared, any level
				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 level
				will be assumed.