Current through Register Vol. 41, No. 3, September 23, 2024
A. A
condition justifying the proclamation of a watch, alert, warning or emergency
stage shall be deemed to exist whenever the board determines that the
accumulation of one or more air pollutants in any place, locality, county or
other area in the state may attain, is attaining or has attained levels which
could, if such levels are sustained or exceeded, lead to a threat to the public
health. In making this determination the conditions specified in subsections B,
C and D of this section shall be used as guidance.
B. Episode criteria.
1. Watch stage. An internal administrative
watch shall be declared by the board whenever the national, local or department
meteorologist issues a forecast indicating an atmosphere stagnation will cover
any substantial portion of the state for an extended period. Such a weather
forecast will indicate meteorological conditions which are expected to inhibit
pollutant dispersion. The watch shall be in effect for those areas of the state
covered by the weather forecast and it shall continue throughout the
atmospheric stagnation period. Such weather forecasts indicating atmospheric
stagnation will take the form of:
a. A
regional air stagnation advisory, including any substantial part of the state,
issued by the National Weather Service; and
b. A forecast by the department meteorologist
indicating local meteorological conditions which inhibit dispersion for an
extended period of time.
2. An alert stage shall be declared by the
board when any one of the following pollutant levels is reached at any
monitoring site concurrent with:
a.
Consultation with the national, local or department meteorologist which
indicates that an atmospheric stagnation exists; or
b. A determination by the board that the
pollutant level is representative of air quality in an air quality control
region and the concentrations of pollutants can be expected to remain at the
following indicated levels for 12 or more hours or increase, or in the case of
ozone, the situation is likely to recur within the next 24 hours unless control
actions are taken. Consultation with the air pollution control agencies of the
affected jurisdictions will be accomplished to help evaluate local situations.
POLLUTANT AVERAGE sg/má3ã ppm
SOå2ç 24 hour 800 .3
PMå10ç 24 hour 350 N/A
CO 8 hour 17,000 15.0
Ozone 1 hour 400 .2
NOå2ç 1 hour 1,130 .6
24 hour 282 .15
3. A warning stage shall be declared by the
board when any one of the following pollutant levels is reached at any
monitoring site concurrent with:
a.
Consultation with the national, local or department meteorologist which
indicates that an atmospheric stagnation exists; or
b. A determination by the board that the
pollutant level is representative of air quality in an air quality control
region and the concentrations of pollutants can be expected to remain at the
following indicated levels for 12 or more hours or increase, or in the case of
ozone, the situation is likely to recur within the next 24 hours unless control
actions are taken. Consultation with the air pollution control agencies of the
affected jurisdictions will be accomplished to help evaluate local situations.
POLLUTANT AVERAGE sg/má3ã ppm
SOå2ç 24 hour 1,600 .6
PMå10ç 24 hour 420 N/A
CO 8 hour 34,000 30.0
Ozone 1 hour 800 .4
NOå2ç 1 hour 2,260 1.2
24 hour 565 .3
4. An emergency stage shall be declared by
the Governor of the Commonwealth of Virginia when any of the following
pollutant levels is reached at any monitoring site concurrent with:
a. Consultation with the national, local or
department meteorologist which indicates that an atmospheric stagnation exists;
or
b. A determination by the board
that the pollutant level is representative of air quality in an air quality
control region and the concentrations of pollutants can be expected to remain
at the following indicated levels for 12 or more hours or increase, or in the
case of ozone, the situation is likely to recur within the next 24 hours unless
control actions are taken. Consultation with the air pollution control agencies
of the affected jurisdictions will be accomplished to help evaluate local
situations.
POLLUTANT AVERAGE sg/má3ã ppm
SOå2ç 24 hour 2,100 .8
PMå10ç 24 hour 500 N/A
CO 8 hour 46,000 40.0
Ozone 1 hour 1,000 .5
NOå2ç 1 hour 3,000 1.6
24 hour 750 .4
5. Termination of any existent stage of air
pollution episode shall be declared by the Governor of the Commonwealth of
Virginia or the board based on:
a.
Consultation with the national, local or department meteorologist which
indicates that the atmospheric conditions justify termination; or
b. Appropriate reduction in pollutant levels.
As the criteria for a given stage are no longer being met, the lowest
appropriate stage will be assumed.
C. When the board determines that a specified
criteria level is being approached and may be reached at one or more monitoring
sites solely because of emissions from a limited number of sources, it may act
to prevent the attainment of the episode level by notifying such sources that
the preplanned abatement strategies of Table VII-A, B or C or the standby plans
are required, insofar as it applies to such sources, and shall be put into
effect until a satisfactory reduction in the ambient pollution concentration
has been achieved.
D. The alert,
warning and emergency stages may be activated on the basis of deteriorating air
quality alone (i.e., an air stagnation advisory need not be in effect) subject
to the determination specified in subdivisions B 2 b, B 3 b and B 4 b of this
section.
