Unless a different meaning is clearly required by context, words and phrases used in this chapter shall have the following meanings, general terms common with other chapters as defined in chapter 173-403 WAC, and terms specific to the emergency episode plan as defined below.

(1) "Air quality control region" means an area designated as an air quality control region by the federal environmental protection agency.

(2) "Episode stage" means a prescribed level of air contaminants or meteorological conditions where certain control actions are required to prevent ambient pollutant concentrations from reaching levels which could cause significant harm to the health of persons.

(3) "Emergency action center" means the headquarters for all department actions during an episode stage.

(4) "Hour" means a 60 minute period, beginning and ending on a clock hour.

(5) "8 hours" means any consecutive 8 hours, starting at any clock hour.

(6) "Major source" means any source which is estimated to emit at an annual rate of twenty-five tons per year or more of SO2, particulates, or carbon monoxide.

(7) "Source emission reduction plan (SERP)" means a plan developed for an individual air pollution source and approved by the director, which sets forth the actions to be taken at that source upon the declaration of various stages of an episode.

(8) "24 hours" means any consecutive 24 hours, starting at any clock hour.