R315-101-5. Health Evaluation Criteria, Risk Assessment

  5.1 REQUIRED STUDY

  (a) When conducting the risk assessment the responsible party will use all applicable site characterization data and shall consider the following parameters when conducting the risk assessment:

  (1) Identification, concentration, and distribution of all suspected hazardous constituents identified in R315-101-4(e);

  (2) All area(s) of contamination at the site;

  (3) Fate of contaminants and pathways of contaminant transport; and

  (4) Potentially exposed populations.

  5.2 CHARACTERIZATION AND EVALUATION OF RISK

  (a) The responsible party shall conduct a risk assessment which includes the following:

  (1) The concentration term "C" for each medium for each hazardous constituent identified in R315-101-5.1(a)(1);

  (2) Evaluation of the fate of contaminants and of all pathways of contaminant transport identified in R315-101-5.1(a)(3);

  (3) Exposure assessment identifying the RME for all exposure pathways, intakes, and identified constituents;

  (4) Current toxicity information for carcinogenic and noncarcinogenic effects;

  (5) Risk characterization identifying carcinogenic risk, individual and multiple substances, and noncarcinogenic hazardous index, individual and multiple substances;

  (6) An ecological evaluation which provides for terrestrial and aquatic processes; and

  (7) Current toxicity information for all the constituents and biological processes relevant to the ecological evaluation.

  (b) The risk assessment shall be conducted using one or both of the standard exposure scenarios listed below, as needed to determine site management options:

  (1) Residential. This exposure scenario includes ingestion of water (must include surface water and ground water regardless of water quality), ingestion of soil and dust, ingestion of contaminated and potentially contaminated food, inhalation of contaminants, dermal contact with chemicals in soil, and dermal contact with chemicals in water for a human being ages zero through 70 years old using the equations and default variable values found in the Risk Assessment Guidance for Superfund, Volume 1: Human Health Evaluation Manual Supplemental Guidance, "Standard Default Exposure Factors", Interim Final, OSWER Directive 9285.6-03, March 25, 1991 or most recent edition;

  (2) Actual land use conditions or potential land use conditions based upon applicable zoning and future land use planning considerations, if potential land use conditions offer a more protective exposure scenario than actual land use conditions. This exposure scenario involves an assessment based on actual site conditions using standard default variable values. The potential land use exposure scenario should include a conceptual model including current site conditions, expected future conditions based upon site-specific physical and chemical information, and the assumption that contaminated media will not have undergone any remedial engineering.

  5.3 DATA PRESENTATION

  (a) A risk assessment report shall be submitted to the Director and must include at a minimum the following:

  (1) An executive summary;

  (2) An overview of the site and the areas of contamination;

  (3) A site characterization report which includes:

  (i) Maps of sufficient detail and accuracy to depict areas of contamination, topography, geology, and groundwater contours or potentiometric surface;

  (ii) Site and regional geological and hydrological descriptions;

  (iii) A detailed discussion of areas of contamination;

  (iv) Background levels of hazardous constituents including details of statistical methods used to determine background; and

  (v) Descriptions of releases of hazardous constituents and expected extent of migration from the area of contamination.

  (4) Identification and concentration of hazardous constituents identified in R315-101-5.1(a)(1). A sampling and analysis plan shall be prepared and utilized for the collection of all data. This plan shall be developed using procedures and methods outlined in Section R315-261-1090 and the most current version of "SW-846, Test Methods for Evaluating Solid Waste." It shall contain a summary outlining data quality objectives, completed analytical request forms for all analysis performed, dry weight equivalents, sampling location identification and justification, standard operating procedures used for data collection, all statistical analysis performed, quality assurance and quality control plans (QA/QC plan) and QA/QC results, instrument calibration results, and analytical methods including constituent detection limits;

  (5) Exposure assessment identifying exposure levels for all exposure pathways identified in R315-101-5.2(a)(3). If fate and transport models are used, the users manual, model theory, computer software for the model, installation verification data set for the model and parametric analysis of the input parameters must be provided upon request of the Director;

  (6) Identification of toxicity information gathered for all identified hazardous constituents for carcinogenic, slope factors and weight-of-evidence classification, noncarcinogenic effects, chronic reference doses (RfDs) and critical effects associated with RfDs from, in order of preference, the Integrated Risk Information System (IRIS), Health Effects Assessment Summary Tables (HEAST), Agency for Toxic Substances and Disease Registry (ATSDR) toxicological profiles, Environmental Criteria and Assessment Office (ECAO), or other scientifically accepted listings. The source and date of the toxicological information must be identified and be acceptable to the Director;

  (7) The risk characterization identifying carcinogenic risk, individual and multiple substances, noncarcinogenic hazardous index, individual and multiple substances, chronic hazard quotient, subchronic hazard quotient, uncertainties, and a tabulation of all risk characterization data presented in a format approved by the Director; and

  (8) Unless justification is provided to the Director, and a waiver of this requirement is granted by the Director in writing, an ecological assessment of the site which contains at least the following:

  (i) An inventory of the current biological community;

  (ii) Estimates of ecological effects based on a subset of ecological endpoints;

  (iii) The magnitude and variation of toxic effects; and

  (iv) Identification of extent of effects, specifically from the presence of hazardous waste.

  (b) If the risk assessment report does not contain all required information of sufficient quality and detail, the Director will notify the responsible party in writing of the deficiencies and require resubmittal of the report in a designated time frame.

  (c) If the risk assessment report contains all required information of sufficient quality and detail, the Director will approve the risk assessment report in writing.