Sec. 212-1.6. Limiting of opacity

(a) No facility owner or operator shall cause or allow emissions having an average opacity during any six consecutive minutes of 20 percent or greater from any process emission source or emission point, except for the emission of uncombined water.

(b) Upon written application by a facility owner or operator, the department may allow for a process emission source or emission point an equivalent opacity standard exceeding the opacity standard of subdivision (a) of this section, if the facility owner or operator can demonstrate through acceptable tests for such source that the facility is in compliance with all applicable emission limits and requirements other than the opacity standard and that the process emission source and any associated emission control equipment is being operated and maintained in a manner acceptable to the department. An equivalent opacity standard for a process emission source will only be allowed where reasonably available control technology (RACT), as determined by the department, has been utilized for air contaminants contributing to opacity. In such cases, the facility owner or operator shall not cause or allow emissions to exceed the equivalent opacity standard.