Washington Administrative Code
Title 173 - Ecology, Department of (See also Titles 197, 317, 372, and 508)
Chapter 173-476 - Ambient air quality standards
Section 173-476-160 - Ambient air quality standards for carbon monoxide
Current through Register Vol. 24-06, March 15, 2024
(1) Standards for carbon monoxide.
(2) Measurement method. The levels of carbon monoxide in the ambient air must be measured by:
(3) Interpretation method. An eight-hour average must be considered valid if at least seventy-five percent of the hourly averages for the eight-hour period are available. In the event that only six (or seven) hourly averages are available, the eight-hour average must be computed on the basis of the hours available using six (or seven) as the divisor.
(4) Rounding of values. When summarizing data for comparison with the standards, averages must be stated to one decimal place. Comparison of the data with the levels of the standards in ppmv must be made in terms of integers with fractional parts of 0.5 or greater rounding up.