The owner or operator shall conduct opacity measurements for a stationary source by using either of the following:

1. (a) 40 CFR 60, Appendix A, Method 9 - Visual Determination of the Opacity of Emissions from Stationary Sources; or
2. (b) A certified opacity CEM system installed on the stack for which the opacity is being measured.

Source. #7788, eff 10-31-02; ss by #9802, eff 10-31-10; ss by #12762, eff 5-1-19