ARM 17.8.332. EMISSION STANDARDS FOR EXISTING ALUMINUM PLANTS--STANDARD FOR VISIBLE EMISSIONS

(1) No owner or operator subject to this rule may cause the emission into the atmosphere from any potroom group of any gasses or particles which exhibit 10% opacity or greater, as determined by EPA Reference Method 9 in Appendix A of 40 CFR Part 60, incorporated by reference in ARM 17.8.302.