40 CFR § 125.32 - Method of application.
(b) The burden is on the person requesting the variance to explain that:
(1) Factor(s) listed in § 125.31(b) regarding the discharger's facility are fundamentally different from the factors EPA considered in establishing the national limits. The requester should refer to all relevant material and information, such as the published guideline regulations development document, all associated technical and economic data collected for use in developing each national limit, all records of legal proceedings, and all written and printed documentation including records of communication, etc., relevant to the regulations which are kept on public file by the EPA;
(2) The alternative limitations requested are justified by the fundamental difference alleged in paragraph (b)(1) of this section; and
(3) The appropriate requirements of § 125.31 have been met.