Iowa Code
Chapter 459B - DRY BEDDED CONFINEMENT FEEDING OPERATIONS
Section 459B.201 - Construction design standards.

459B.201 Construction design standards.
A person constructing a dry bedded confinement feeding operation structure on karst terrain or in an alluvial aquifer area shall comply with all of the following:
1. The person must construct the dry bedded confinement feeding operation structure at a location where there is a vertical separation distance of at least five feet between the bottom of the floor of the dry bedded confinement feeding operation structure and the underlying limestone, dolomite, or other soluble rock in karst terrain or the underlying sand and gravel aquifer in an alluvial aquifer area.
2. The person must construct the dry bedded confinement feeding operation structure with a floor consisting of reinforced concrete at least five inches thick.
2009 Acts, ch 155, §9, 18