Tier 3 Assessment

Unless limited by rule, an owner or operator may choose to prepare a Tier 3 site assessment as an alternative to completion of a Tier 2 Site Cleanup Report or Corrective Action Design Report. Prior to conducting a Tier 3 site assessment, a workplan must be submitted to the department for approval. The workplan should follow an outline similar to a scientific experiment and should include an introduction, description of methods and models to be used, discussion of risk classification, summary and references.

The Tier 3 workplan may include a proposal for additional site assessment, the use of probabilistic evaluations, or more sophisticated chemical fate and transport models. Calibration of the IDNR Tier 2 model can also be considered with justification. Following approval of the workplan, a Tier 3 assessment report will be required within a reasonable time designated by the department.

The Tier 3 assessment report must include a recommendation for site classification as high risk, low risk or no action required. If a corrective action is required, the Tier 3 report must provide an outline of possible corrective actions technologies and a recommendation for implementation of a remediation technology which is consistent with the standards and policies underlying the department's risk classification and corrective action response rules.