General

General. A. Introduction (1) The Mississippi Brownfields Voluntary Cleanup and Redevelopment Program (Brownfields Program) utilizes risk-based criteria for Site evaluation and remediation. The risk-based procedures and rationale for evaluating environmental contamination on or under a Site are presented in this Subchapter II. This evaluation is necessary to develop remediation requirements that are protective of human health and the environment. All remediation and/or corrective actions must be approved by MDEQ. (2) In considering the risk-based evaluation of conditions on or under a Site, the following must be addressed: (a) complete the Site Conceptual Exposure Model (SCEM) to evaluate site- specific risk and exposure conditions before and after remediation; (b) conduct a Site Characterization to delineate the nature and extent (vertically and horizontally) of contamination found on or under the Site; (c) complete the Site Ecological Checklist to determine whether an ecological risk assessment is necessary; and (d) conduct a Risk-Based Evaluation of the Site utilizing the Brownfields Program three-tiered approach. (3) The cornerstone of the Brownfields Program is a three-tiered risk-based process for evaluating human health and environmental risks. These tiers are referred to as Tier 1, Tier 2, and Tier 3. These tiers are designed to allow the Applicant to evaluate and determine appropriate remedial options for site specific conditions. A description of each tier is discussed below. (a) A Tier 1 Evaluation is the comparison of site-specific data to a "look-up" table of chemical-specific target remediation goals (TRGs). Specific TRG concentrations have been determined to be protective of human health and the environment for restricted use and unrestricted use of a Site. The Tier 1 TRG Table is presented in Appendix A. (b) A Tier 2 Evaluation provides the Applicant the option of performing a more in-depth evaluation of site-specific conditions to develop site-specific Remediation Goals (RG) and/or to better define site-specific data to be used for a Tier 1 Evaluation. (c) A Tier 3 Evaluation is a site-specific risk assessment to evaluate the potential human health and ecological risks at the Site that will result in the development of site-specific Remediation Goals (RGs). (4) Land use plays an integral role in the three-tiered approach and in the development of the SCEM. Land-use restrictions may reduce or eliminate the potential for exposure to contaminants and risk. (5) Specific criteria for evaluating Sites impacted with petroleum hydrocarbons is contained in Rule 2.2.7 of this Subchapter.