StacksVerified U.S. regulatory reference

40 CFR §62.14755a

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
After the date the initial test for opacity is required or completed (whichever is earlier), you must meet the limitations in paragraphs (a) and (b) of this section.
  1. (a)Maintain opacity to less than or equal to 10 percent opacity (as determined by the average of three 1-hour blocks consisting of ten 6-minute average opacity values), except as described in paragraph (b) of this section.
  2. (b)Maintain opacity to less than or equal to 35 percent opacity (as determined by the average of three 1-hour blocks consisting of ten 6-minute average opacity values) during the startup period that is within the first 30 minutes of operation.