Iowa Admin. Code r. 27-60.80
60.80(5) Waste disposal. In grading the site all mining-related waste products and machinery incompatible with the care and growth of vegetation shall be removed from the site and disposed of in a manner consistent and acceptable with state law. Materials acceptable for on-site disposal, such as concrete and clay products free of reinforcing shall be buried a minimum of three feet below final grade.
Boulders and stones incompatible with the proposed postmining use of the site shall be buried or removed from the site.
60.80(6) Vegetation. Seeding of an area with grasses and legumes shall be accomplished within three months following the conclusion of all earthwork, weather permitting. Erosion control methods shall be used where necessary to prevent rill and gully formation. The operator shall be responsible for attaining a ground cover of acceptable species of grass, legume, shrub, tree or crop.
The vegetation shall be allowed at least one growing season to become established prior to the filing of a release request by the operator.
If necessary, additional seedings shall be performed to establish a viable vegetative cover.