Whether there is a 'discharge of a pollutant' under the Clean Water Act when material already within a regulated waterbody is merely moved or resuspended within that waterbody?

QUESTION PRESENTED The Clean Water Act forbids the unpermitted “discharge of any pollutant” into “navigable waters.” 33 U.S.C. §§ 1311(a), 1362(11). The Act defines “discharge of a pollutant” as “any addition of any pollutant to navigable waters[.]” Id. § 1362(12). This Court has twice held that, as a matter of ordinary meaning, there can be no “addition of any pollutant” unless there is an increase of pollutants to a waterbody. S. Florida Water Mgmt. Dist. v. Miccosukee Tribe of Indians, 541 U.S. 95, 109-12 (2004); Los Angeles Cnty. Flood Control Dist. v. Natural Res. Def. Council, Inc., 568 U.S. 78, 82-84 (2013). In conflict with these decisions, as well as rulings from several courts of appeals, the Ninth Circuit below found “addition” ambiguous, applied Chevron deference, and held that Petitioner’s smallscale suction dredge mining added pollutants to an Idaho river—even though his mining just temporarily resuspended material in the water column that was already present within the waterbody. The question presented is: Whether there is a “discharge of a pollutant” under the Clean Water Act when material already within a regulated waterbody is merely moved or resuspended within that waterbody?