40 C.F.R. §§ 125.30–125.32

This subpart establishes the criteria and standards to be used in determining whether effluent limitations alternative to those required by promulgated EPA effluent limitations guidelines under sections 301 and 304 of the Act (hereinafter referred to as “national limits”) should be imposed on a discharger because factors relating to the discharger's facilities, equipment, processes or other factors related to the discharger are fundamentally different from the factors considered by EPA in development of the national limits. This subpart applies to all national limitations promulgated under sections 301 and 304 of the Act, except for the BPT limits contained in 40 CFR 423.12 (steam electric generating point source category).

In establishing national limits, EPA takes into account all the information it can collect, develop and solicit regarding the factors listed in sections 304(b) and 304(g) of the Act. In some cases, however, data which could affect these national limits as they apply to a particular discharge may not be available or may not be considered during their development. As a result, it may be necessary on a case-by-case basis to adjust the national limits, and make them either more or less stringent as they apply to certain dischargers within an industrial category or subcategory. This will only be done if data specific to that discharger indicates it presents factors fundamentally different from those considered by EPA in developing the limit at issue. Any interested person believing that factors relating to a discharger's facilities, equipment, processes or other facilities related to the discharger are fundamentally different from the factors considered during development of the national limits may request a fundamentally different factors variance under § 122.21(l)(1). In addition, such a variance may be proposed by the Director in the draft permit.

A request for the establishment of effluent limitations under this subpart (fundamentally different factors variance) shall be approved only if:

A request for the establishment of effluent limitations less stringent than those required by national limits guidelines shall be approved only if:

A request for alternative limits more stringent than required by national limits shall be approved only if:

Factors which may be considered fundamentally different are:

A variance request or portion of such a request under this section shall not be granted on any of the following grounds:

Nothing in this section shall be construed to impair the right of any State or locality under section 510 of the Act to impose more stringent limitations than those required by Federal law.

A written request for a variance under this subpart D shall be submitted in duplicate to the Director in accordance with §§ 122.21(m)(1) and 124.3 of this chapter.