Upon the promulgation of any Federal Categorical Pretreatment Standard for a particular industrial subcategory, developed pursuant to 40 CFR, Sec. 403.6, the Federal Standard, if more stringent than limitations imposed herein for sources in that subcategory, shall immediately supersede the limitations imposed herein. The POTW manager shall notify all affected users of the applicable reporting requirements under 40 CFR, Sec.12.