Compliance with the pretreatment standards for existing sources set forth in § 420.15 of this subpart is required not later than October 17, 2005 whether or not the pretreatment authority issues or amends a pretreatment permit requiring such compliance. Until that date, the pretreatment standards for existing sources set forth in Subpart A of title 40 of the Code of Federal Regulations, revised as of July 1, 2001, shall continue to apply.