Section 56.4 - Mechanisms for fairness and uniformity-Responsibilities of Headquarters employees(a) The Administrator shall include, as necessary, with any rule or regulation proposed or promulgated under parts 51 and 58 of this chapter mechanisms to assure that the rule or regulation is implemented and enforced fairly and uniformly by the Regional Offices.(b) The determination that a mechanism required under paragraph (a) of this section is unnecessary for a rule or regulation shall be explained in writing by the responsible EPA official and included in the supporting documentation or the relevant docket.(c) The Administrator shall not be required to issue new mechanisms or revise existing mechanisms developed under paragraphs (a) of this section to address the inconsistent application of any rule, regulation, or policy that may arise in response to the limited jurisdiction of either a federal circuit court decision arising from challenges to "locally or regionally applicable" actions, as provided in Clean Air Act section 307(b) (42 U.S.C. 7607(b) ), or a federal district court decision.45 FR 85405, Dec. 24, 1980, as amended at 81 FR 51113 , Aug. 3, 2016