How does flooding impact NPDES permits?

Gary Baise found this ruling on the impact if flooding on animal agriculture that is very pertinent to what our some of our coastal regions are facing.   The Clean Water Act prohibits the discharge of a pollutant into the navigable waters of the United States without a permit, specifically an NPDES permit. Under the Clean Water Act, discharges from certain animal feeding operations that occur under certain rainfall conditions are subject to a narrow exemption from the NPDES regulations for Concentrated Animal Feeding Operations (CAFOs). See§3.0, p 16 of EPA’s 1995 Guide Manual on NPDES Regulations for Concentrated Animal Feeding Operations, EPA 833-B-95-001 (December 1995) (hereinafter “EPA’s 1995 CAFO Guide Manual”). According to 40 CFR 122, Appendix B, an animal feeding operation is not a CAFO if it discharges only in the event of a 25-year, 24-hour storm. See §3.1, p. 16 of EPA’s 1995 CAFO Guide Manual. 40 C.F.R. §411 defines a 25-year, 24-hour rainfall event as a rainfall event with a probable recurrence interval of once in twenty-five years as defined by the National Weather Service in Technical Paper Number 40, “Rainfall Frequency Atlas of the United States”, May 1961, and subsequent amendments, or equivalent regional or State rainfall probability information developed therefrom. In most of eastern North Carolina, this event is 5, 6 or 7 inches, depending on the precise location. This exemption applies to all feedlots, including CAFOs designated as such on a case by case basis.