S.C. Code Regs. § § 61-62.3.I

Current through Register Vol. 48, No. 9, September 27, 2024

Section 61-62.3.I - EPISODE CRITERIA

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.

S.C. Code Regs. § 61-62.3.I

Amended by State Register Volume 37, Issue No. 4, eff April 26, 2013.