Fairhurst v. Hagener, 422 F.3d 1146 (9th Cir. 2005) (holding pesticides discharged into navigable waters in compliance with FIFRA that leave no excess material after fulfilling their intended purpose, are not "pollutants" requiring an NPDES permit under the Clean Water Act).
Michael J. Graetz,
Fairhurst v. Hagener,
U. Denv. Water L. Rev.
Available at: https://scholarship.law.columbia.edu/faculty_scholarship/940