ARSD 74:56:05:11. Tier 2 action levels -- Criteria

The responsible person must calculate Tier 2 action levels based on actual site conditions, as follows: (1) Toxicity information must be obtained from sources consistent with EPA's "Risk Assessment Guidance for Superfund" (1989). The department may allow the development of a toxicity value if required and applicable toxicological data are available; (2) The excess lifetime cancer risk may not exceed 1:100,000 for all pathways; (3) The chronic noncancer risk may not exceed a hazard index of one for all pathways; (4) Reasonable maximum exposure default values as determined in EPA's "Risk Assessment Guidance for Superfund" (1989) must be used for exposure assessments or site-specific exposure data may be used with the permission of the department; (5) "Tier 2 RBCA Guidance Manual for Risk-Based Corrective Action" (1995a; 1995b) is the source for fate and transport models for development of Tier 2 action levels; (6) The department shall approve the location of monitoring points to ensure compliance with the South Dakota groundwater quality standards in chapter 74:54:01 and the conditions listed in subdivisions (2) and (3) in this section.