Today, in Decker v. Northwest Environmental Defense Center, the United States Supreme Court ruled that citizen suits under section 505 of the Clean Water Act may be used to challenge EPA’s interpretation of its own regulations at any time after the regulation has been promulgated so long as the challenge states that the rule is ambiguous and is being misinterpreted. The citizen suit cannot seek an “implicit declaration that the … regulation were invalid as written.”
This opens a door for challenging rules long after they have been adopted. Typically a rule is challenged under section 509 of the Clean Water Act and that challenge has to be brought within 180 days of the promulgation of the rule.
Aside from the procedural issue, this case also covers an important substantive issue of whether channeled stormwater runoff from loggings roads may be exempt from requiring a NPDES permit. The 9th circuit court of appeals had determined that the stormwater discharge could not be exempt from the permitting requirements and therefore was a discharge without a permit. The Supreme Court overturned this decision, deferring to the Environmental Protection Agency’s interpretation of its own regulations.
The opinion can be found at: https://www.supremecourt.gov/opinions/12pdf/11-338_kifl.pdf