The federal method for visual determination of opacity of emissions and requirements for qualified observers as defined in 40 CFR Part 60, Appendix A, Method 9, as amended through November 14, 1990, is adopted by reference.
To qualify as an observer, a candidate must, after meeting the requirements established in 40 CFR Part 60, Appendix A, Method 9, have on record with the department a minimum of 250 readings of black plumes and 250 readings of white plumes, taken at approved smoke reading courses.
Iowa Admin. Code r. 567-21.13