{"data":{"id":"us-va/9vac5-80-1635","jurisdiction":"us-va","citation":"9VAC5-80-1635","heading":"Ambient air increments","body":"In areas designated as class I, II or III, increases in pollutant concentration over the baseline concentration shall be limited to the following:\n\nMAXIMUM ALLOWABLE INCREASE\n\n(micrograms per cubic meter)\n\nClass I Area\n\nPM2.5:\n\nAnnual arithmetic mean\n\n1\n\n24 hour maximum\n\n2\n\nPM10:\n\nAnnual arithmetic mean\n\n4\n\n24 hour maximum\n\n8\n\nSulfur dioxide:\n\nAnnual arithmetic mean\n\n2\n\n24-hour maximum\n\n5\n\nThree-hour maximum\n\n25\n\nNitrogen dioxide:\n\nAnnual arithmetic mean\n\n2.5\n\nClass II Area\n\nPM2.5:\n\nAnnual arithmetic mean\n\n4\n\n24 hour maximum\n\n9\n\nPM10:\n\nAnnual arithmetic mean\n\n17\n\n24 hour maximum\n\n30\n\nSulfur dioxide:\n\nAnnual arithmetic mean\n\n20\n\n24-hour maximum\n\n91\n\nThree-hour maximum\n\n512\n\nNitrogen dioxide:\n\nAnnual arithmetic mean\n\n25\n\nClass III Area\n\nPM2.5:\n\nAnnual arithmetic mean\n\n8\n\n24 hour maximum\n\n18\n\nPM10:\n\nAnnual arithmetic mean\n\n34\n\n24 hour maximum\n\n60\n\nSulfur dioxide:\n\nAnnual arithmetic mean\n\n40\n\n24-hour maximum\n\n182\n\nThree-hour maximum\n\n700\n\nNitrogen dioxide:\n\nAnnual arithmetic mean\n\n50\n\nFor any period other than an annual period, the applicable maximum allowable increase may be exceeded during one such period per year at any one location.","path":["Title 9. Environment","Agency 5. State Air Pollution Control Board","Chapter 80. Permits for Stationary Sources","Part II. Permit Procedures","Article 8. Permits for Major Stationary Sources and Major Modifications Locating in Prevention of Significant Deterioration Areas"],"source_url":"https://law.lis.virginia.gov/admincode/title9/agency5/chapter80/section1635/","current_through":"2026 Regular Session (effective July 1, 2026)","vintage":"","retrieved_at":"2026-09-14T04:48:37Z","sha256":"c37f9956c40e328b834fd6731514ec0818cf1bc08dca481d805970b23a6e9181","source_id":"us-va-vac","stale":false,"prev":"us-va/9vac5-80-1625","next":"us-va/9vac5-80-1645"},"notice":"GroundRules: Original legal text. Not legal advice."}