40 CFR § 62.15380
How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste?
June 9, 2020
(a) Use EPA Reference Method 9 in appendix A of 40 CFR part 60 to determine compliance with the opacity limit.
(b) Conduct an initial test for opacity as specified in §60.8 of subpart A of 40 CFR part 60.
(c) After the initial test for opacity, conduct annual tests no more than 13 calendar months following the date of your previous test.