528 U.S. 167 (2000)
- The Supreme Court (Court) reversed an appeals court decision that held that petitioners' citizen suit for civil penalties under Clean Water Act was moot when respondent came into compliance.
- The Court first addressed whether petitioners had standing to bring the action. It found respondent's discharges, and petitioners' reasonable concerns about the effects of those discharges, directly affected petitioners' recreational, aesthetic, and economic interests.
- The civil penalties petitioners sought carried with them a deterrent effect that made it likely the penalties would redress petitioners' injuries by abating current violations and preventing future ones.
- Thus, petitioners had standing.
- The Court then addressed whether the matter became moot when respondent came into compliance with its discharge permit.
- The Court held the action may have become moot only if respondent's compliance or respondent's closure of its facility made it absolutely clear that respondent's permit violations could not reasonably be expected to recur.
- The effect of respondent's compliance and facility closure on the prospect of future violations was a disputed factual matter.
- Thus, the matter was not moot.
The appellate court's decision was reversed; the appellate court erred in concluding that petitioners' claim for civil penalties had to be dismissed as moot when respondent, albeit after commencement of the litigation, came into compliance.