74:56:05:09Corrective action or

Tier 2 assessment required. If soil contaminant levels exceed Tier 1 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 2 action levels based on actual site conditions. If the department determines that the plan will reduce the risk 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 2 assessment are: (1) The assumptions used to calculate the Tier 1 action levels are not applicable to actual site conditions; (2) It is likely that Tier 2 action levels will be different from Tier 1 action levels; and (3) The cost of performing a Tier 2 assessment and implementation of corrective action to Tier 2 action levels is likely to be substantially less than the cost of corrective action under Tier 1.

Source: 22 SDR 86, effective December 18, 1995; transferred from § 74:03:33:09, July 1, 1996.