Rule 17.8.331 - EMISSION STANDARDS FOR EXISTING ALUMINUM PLANTS-STANDARDS FOR FLUORIDE(1) No owner or operator subject to the provisions of this rule may cause the emission into the atmosphere from any existing primary aluminum reduction plant of any gasses which contain total fluorides in excess of 1.3 kg/Mg (2.6 lb/ton) of aluminum produced at Soderberg plants averaged over any calendar month.NEW, 1982 MAR p. 390, Eff. 2/26/82; TRANS, from DHES, 1996 MAR p. 2285.75-2-111, 75-2-203, MCA; IMP, 75-2-203, MCA;