CFR›Title 40›Chapter I›Part 51›Subpart J ContainsSection 51.190CorpusDaily eCFRDisplayed edition2026-05-18Last updated2026-05-18 Subpart J—Ambient Air Quality Surveillance Sections 51.190 § 51.190 Ambient air quality monitoring requirements. AuthoritySecs. 110, 301(a), 313, 319, Clean Air Act (42 U.S.C. 7410, 7601(a), 7613, 7619). Previous H Subpart H—Prevention of Air Pollution Emergency Episodes Next K Subpart K—Source Surveillance