(1) Pretreatment standards specifying quantities or concentrations of pollutants or pollutant properties that may be discharged to a POTW by existing or new industrial users in specific industrial subcategories may be established as separate regulations under ARM Title 17, chapter 30.   These standards, unless specifically noted otherwise, are in addition to all applicable pretreatment standards and requirements set forth in this subchapter.

(2) In addition to the general prohibitions in ARM 17.30.1406(1) , all indirect dischargers must comply with national pretreatment standards promulgated by the EPA and codified in 40 CFR Chapter 1, subchapter N.   Compliance is required within the time specified in the appropriate subpart of subchapter N.

(3) Industrial users may request the department to provide written certification on whether an industrial user falls within a particular subcategory.   The department will act upon that request in accordance with the procedures in 40 CFR 403.6.

(4) Limitations for industrial users will be imposed in accordance with 40 CFR 403.6(c) -(e) .

(5) The board hereby incorporates by reference herein 40 CFR Chapter I, Subchapter N (Effluent Guidelines and Standards) (July 1, 1991) , 40 CFR 403.6 (National Pretreatment Standards: Categorical Standards) (July 1, 1991) ; and 40 CFR Part 136 (Guidelines Establishing Text Procedures for Analysis of Pollutants) (July 1, 1991) .   Copies of these materials are available from the Department of Environmental Quality, PO Box 200901, Helena, MT 59620-0901.