ARSD 74:56:05:12. Corrective action of Tier 3 assessment required

If soil contaminant levels exceed the Tier 2 action levels, the responsible person must submit a corrective action plan to the department for approval or, if the site meets the criteria listed below, the responsible person may calculate Tier 3 action levels using site-specific models. If the department determines that the plan will reduce the risks associated with the site to below the criteria in subdivisions (2) and (3) of § 74:56:05:11, the department shall approve the plan and the responsible person must implement the corrective action. The criteria for progressing to a Tier 3 assessment are: (1) The assumptions used to calculate the Tier 2 action levels are not applicable to actual site conditions; (2) It is likely that Tier 3 action levels will be different from Tier 2 action levels; and (3) The cost of performing a Tier 3 assessment and implementation of corrective action to Tier 3 action levels is likely to be substantially less than the cost of correction action under Tier 2.