If because of topography or other factors related to the site of an open feedlot operation it is economically or physically impractical to comply with open feedlot effluent control requirements using an open feedlot control method in section 459A.401, the department shall allow the use of other open feedlot effluent control practices if those practices will provide an equivalent level of open feedlot effluent control that would be achieved by using an open feedlot effluent control method pursuant to section 459A.401.
Iowa Code § 459A.402
2005 Acts, ch 136, §15