459A.401  Open feedlot effluent control methods.
  An open feedlot operation shall provide for the management of open feedlot effluent by using an open feedlot effluent control method as follows:
  1.  All settleable solids from open feedlot effluent shall be removed prior to discharge into a water of the state.
  a.  The settleable solids shall be removed by use of a solids settling facility. The construction of a solids settling facility is not required where existing site conditions provide for removal of settleable solids prior to discharge into a water of the state.
  b.  The removal of settleable solids shall be deemed to have occurred when the velocity of flow of the open feedlot effluent has been reduced to less than point five feet per second for a minimum of five minutes. A solids settling facility shall have sufficient capacity to store settled solids between periods of land application and to provide required flow-velocity reduction for open feedlot effluent flow volumes resulting from a precipitation event of less intensity than a ten-year, one-hour frequency event. A solids settling facility which receives open feedlot effluent shall provide a minimum of one square foot of surface area for each eight cubic feet of open feedlot effluent per hour resulting from a ten-year, one-hour frequency precipitation event.
  2.  Notwithstanding subsection 1, an open feedlot operation that is a concentrated animal feeding operation shall comply with applicable NPDES permit requirements as provided in the federal Water Pollution Control Act, pursuant to rules that shall be adopted by the commission. Any rules adopted pursuant to this subsection shall be no more stringent than requirements under the federal Act.
  3.  If the open feedlot operation is designed, constructed, and operated in accordance with the requirements of an open feedlot effluent control system as provided in rules adopted by the commission, the operation shall be deemed to be in compliance with this section, unless a discharge from the operation causes a violation of state water quality standards as provided in chapter 455B, subchapter III.
  4.  The following shall apply to an open feedlot operation which has an animal unit capacity of one thousand animal units or more:
  a.  (1)  The open feedlot operation shall not discharge open feedlot effluent from an open feedlot operation structure into any waters of the United States, unless the discharge is pursuant to an NPDES permit.
  (2)  The open feedlot operation shall not be required to be issued an NPDES permit if the operation does not discharge open feedlot effluent into any waters of the United States.
  b.  The control of open feedlot effluent originating from the open feedlot operation may be accomplished by the use of a solids settling facility, settled open feedlot effluent basin, alternative technology system, or any other open feedlot effluent control structure or practice approved by the department. The department may require the diversion of surface drainage prior to contact with an open feedlot operation structure. Solids shall be settled from open feedlot effluent before the effluent enters a settled open feedlot effluent basin or alternative technology system.
2005 Acts, ch 136, §14; 2007 Acts, ch 126, §82; 2008 Acts, ch 1191, §145, 148; 2015 Acts, ch 92, §38 – 40; 2021 Acts, ch 76, §150
Referred to in §459A.205, 459A.303, 459A.402