(1) Standard for PM-10. The twenty-four-hour average concentration of PM-10 in the ambient air must not exceed 150 µg/m3 more than one time per year, on a three-year average.

(2) Measurement method. The levels of PM-10 in the ambient air must be measured by:

(a) A FRM based on 40 C.F.R. Part 50, Appendix J and designated according to 40 C.F.R. Part 53; or

(b) A FEM designated according to 40 C.F.R. Part 53.

(3) Interpretation method. The interpretation method found in 40 C.F.R. Part 50, Appendix K must be used.