15A NCAC 02D .2610 OPACITY (a) Method 9 of Appendix A of 40 CFR 60 shall be used to show compliance with opacity standards when opacity is determined by visual observation. (b) Method 22 Appendix A of 40 CFR 60 shall be used to determine compliance with opacity standards when such standards are based upon the frequency of fugitive emissions from stationary sources as specified in the applicable rule or by permit condition. History Note: Authority G.S. 143-215.3(a)(1); 143-215.65; 143-215.66; 143-215.107(a)(5); Eff. June 1, 2008.