IMPERIAL COUNTY AIR POLLUTION CONTROL DISTRICT
RULE 603 - EPISODE STAGES
(Last revised or adopted prior to October 15, 1979)
Stage 1 (Health Advisory - Alert): A health advisory is issued when the concentration of the pollutants specified for this stage is predicted or reached.
Stage 2 (Warning): A warning is called when the concentration of pollutants specified for this stage is predicted or reached.
Stage 3 (Emergency): An emergency is called when the conditions specified for this stage are reached; and in the case of the one hour criteria for carbon monoxide or oxidants, are predicted to persist for one additional hour.
Episode Termination: A stage is terminated whenever the concentration of the pollutant(s) which cause the declaration of the episode has been verified to have fallen below the criteria level for the declaration of the episode and meteorological data indicate that the pollutant concentration is expected to decrease.
* and predicted to persist for one additional hour.