33 U.S. Code § 1365 - Citizen suits
The court, in issuing any final order in any action brought pursuant to this section, may award costs of litigation (including reasonable attorney and expert witness fees) to any prevailing or substantially prevailing party, whenever the court determines such award is appropriate. The court may, if a temporary restraining order or preliminary injunction is sought, require the filing of a bond or equivalent security in accordance with the Federal Rules of Civil Procedure.
Nothing in this section shall restrict any right which any person (or class of persons) may have under any statute or common law to seek enforcement of any effluent standard or limitation or to seek any other relief (including relief against the Administrator or a State agency).
For purposes of this section, the term “effluent standard or limitation under this chapter” means (1) effective July 1, 1973, an unlawful act under subsection (a) of section 1311 of this title; (2) an effluent limitation or other limitation under section 1311 or 1312 of this title; (3) standard of performance under section 1316 of this title; (4) prohibition, effluent standard or pretreatment standards under section 1317 of this title; (5) certification under section 1341 of this title; (6) a permit or condition thereof issued under section 1342 of this title, which is in effect under this chapter (including a requirement applicable by reason of section 1323 of this title); or (7) a regulation under section 1345(d) of this title,.
For the purposes of this section the term “citizen” means a person or persons having an interest which is or may be adversely affected.
A Governor of a State may commence a civil action under subsection (a) of this section, without regard to the limitations of subsection (b) of this section, against the Administrator where there is alleged a failure of the Administrator to enforce an effluent standard or limitation under this chapter the violation of which is occurring in another State and is causing an adverse effect on the public health or welfare in his State, or is causing a violation of any water quality requirement in his State.
 So in original.
The Federal Rules of Civil Procedure, referred to in subsec. (d), are set out in the Appendix to Title 28, Judiciary and Judicial Procedure.
Subsec. (c)(3). Pub. L. 100–4, § 504, added par. (3).
Subsec. (d). Pub. L. 100–4, § 505(c), inserted “prevailing or substantially prevailing” before “party”.
Subsec. (f). Pub. L. 100–4, § 406(d)(2), added cl. (7).