Mo. Rev. Stat. § 260.352: Department of natural resources shall verify compliance with corrective action plans for hazardous waste management.

All corrective action plans approved by the department pursuant to the provisions of sections 260.350 to 260.430 shall require the department, upon notice by the owner or operator that the approved plan has been completed, to verify within ninety days that the corrective action plan has been complied with and completed. The department shall issue a letter within thirty business days to the owners or operators certifying the completion and compliance.