Code of Federal Regulations > Title 40 > Chapter I > Part 65 > Subpart F

Regulations last checked for updates: Jun 17, 2025

Title 40 - Protection of Environment last revised: Nov 17, 2025

Appendix -

Operating time (percent of year)	Equivalent continuous process monitoring frequency time in use
Operating time (percent of year)	Monthly	Quarterly	Semiannually
0 to <25	Quarterly	Annually	Annually.
25 to <50	Quarterly	Semiannually	Annually.
50 to <75	Bimonthly	Three times	Semiannually.
75 to 100	Monthly	Quarterly	Semiannually.

authority: 42 U.S.C. 7401

source: 65 FR 78285, Dec. 14, 2000, unless otherwise noted.