(a) General requirement. The person shall use the criteria provided in subsections (b) - (j) of this section and the risk-based exposure limit (RBEL) equations provided in the following figures, as applicable, to establish RBELs appropriate for the type of chemical of concern (COC), the complete and reasonably anticipated to be completed exposure pathways, receptors, and land uses. The person shall establish RBELs for carcinogenic COCs and noncarcinogenic COCs using the default exposure factors provided in the following figure for residents and commercial/industrial workers, unless the executive director approves the use of alternate exposure factors in accordance with subsection (j) of this section.
Attached Graphic
(b) Air inhalation RBEL. The air inhalation RBEL (Air RBELInh ) is the protective concentration of a COC in air at the point of exposure (POE) for human inhalation.
  (1) Under Tiers 2 and 3 as described in §350.75 of this title (relating to Tiered Human Health Protective Concentration Level Evaluation), the person may use the lower of available eight-hour time-weighted average occupational inhalation criteria (i.e., Occupational Safety and Health Administration Permissible Exposure Limits, or American Conference of Governmental Industrial Hygienists Threshold Limit Values), as Air RBELInh for inhalation pathways for commercial/industrial workers within the limits of affected commercial/industrial properties which have a health and safety plan in place. The health and safety plan shall be designed to ensure compliance with the applicable occupational inhalation criteria and require the monitoring of COC levels in the working air environment, and specify actions that will be taken in the event of exceedance of the occupational inhalation criteria. When occupational inhalation criteria are used, the person shall provide documentation of the health and safety plan, certify that the plan is followed, and demonstrate that the off-site receptors are protected as required by §350.71(h) of this title (relating to General Requirements). The use of occupational inhalation criteria as RBELs shall require the person to comply with the institutional control requirements in §350.111(b) and (b)(14) of this title (relating to Use of Institutional Controls).
  (2) The air RBELs may not exceed any other applicable federal or state air quality standards.
(c) Soil dermal contact RBEL. The soil dermal contact RBEL (Soil RBELDerm ) is the protective concentration of a COC at the POE in soil based upon direct dermal contact to soil by humans. The soil dermal contact RBEL shall also be based on COC-specific values for dermal absorption fraction (ABS.d) and gastrointestinal absorption fraction (ABSGI ) provided in the following figure, unless the executive director approves the use of alternate ABS.d and ABSGI values in accordance with subsection (j)(1)(A) and (B) of this section. It is not necessary to calculate a soil dermal contact RBEL for COCs with vapor pressure in mm of Hg greater than or equal to 1.
Attached Graphic
(d) Soil ingestion RBEL. The soil ingestion RBEL (Soil RBELIng ) is protective concentration of a COC at the POE in soil based upon human ingestion.
(e) Vegetable ingestion RBELs. The vegetable RBELs (AbgVeg RBELIng and BgVeg RBELIng ) are the protective concentration of a COC in aboveground vegetables and below-ground vegetables, respectively, for ingestion by residents. The person shall establish RBELs for ingestion of aboveground vegetables for all carcinogenic and noncarcinogenic COCs which are metals. In addition, the person shall establish RBELs for ingestion of below-ground vegetables for all carcinogenic and noncarcinogenic COCs with a dimensionless Henry's Law Constant less than 0.03, as shown in the figure in §350.73(f) of this title (relating to Determination and Use of Human Toxicity Factors and Chemical Properties), when either of the following criteria are met:
  (1) the COC is a metal; or
  (2) the COC has a logarithmic octanol-water partition coefficient (Log Kow ) greater than four as shown in the figure in §350.73(f) of this title ; or
(f) Groundwater ingestion RBEL.
  (1) The groundwater ingestion RBEL ( GW RBELIng ) is the protective concentration of a COC at the POE in groundwater based upon human ingestion of groundwater. However, if available, the person shall use the lower of the two values established under paragraphs (2) and (3) of this subsection instead.
  (2) The person shall use the primary maximum contaminant level (MCL) as provided in 40 Code of Federal Regulations (CFR) Part 141, as amended, or the most currently available federal action level for drinking water (e.g., lead and copper) as the RBEL when available for the COC.
  (3) The person shall use the secondary MCLs established for individual COCs as provided in 40 CFR Part 143, as amended, as RBELs, or other scientifically valid published criteria in cases where COCs are present at concentrations which present objectionable characteristics such as taste or odor (e.g., methyl tertiary butyl ether) under the following circumstances:
    (A) when the COCs are present in class 1 groundwater;
    (B) when the COCs are present in class 2 groundwater that is within 1/2 mile of a well used to supply drinking water and is also within or is likely to migrate, based upon the chemical properties of the COCs and the hydrogeology, to the groundwater production zone of such drinking water supply well; or
    (C) when the COCs are present in class 2 groundwater and there are no alternative water supplies available.
(g) Class 3 groundwater RBEL. The class 3 groundwater RBEL (GW RBELClass 3 ) is the acceptable concentration of a COC at the POE in class 3 groundwater.
(h) Surface water RBEL. The surface water RBEL (SW RBEL) is the protective concentration of a COC at the POE in surface water. To establish SW RBEL for a COC, the person shall determine the lowest value from paragraphs (1) - (5) of this subsection for each COC, unless the person has sufficient surface water quality information specific to the particular surface water body to support an adjustment to the RBEL in accordance with paragraph (6) of this subsection. The SW RBEL value determined pursuant to paragraphs (1) - (6) of this subsection may require modification in response to the requirements of paragraphs (7) and (8) of this subsection. TheSW RBEL value for a given COC shall be protective of relevant downgradient water bodies in consideration of the water body use (e.g., designated drinking water supply or sustainable fishery), the water body type (e.g., estuary or perennial freshwater stream), the standards applicable to the type of water body/use, and the fate and transport characteristics of the COC in question at the particular affected property.
  (1) The person shall apply the lower of the acute or chronic criteria for fresh or marine waters as applicable, based on the classification of the surface water, to protect aquatic life as provided in §307.6, Table 1 of this title (relating to Toxic Materials), as amended. The person shall determine the applicability of aquatic life criteria related to the water body aquatic life use and flow conditions in accordance with the procedures contained in §§307.3, 307.4, and 307.6 of this title (relating to Definitions and Abbreviations; General Criteria; and Toxic Materials, respectively), and the agency's Implementation Procedures, as amended, as defined in §350.4 of this title (relating to Definitions and Acronyms), as amended. For fresh waters, the person shall calculate aquatic life criteria for metals with hardness-dependent criteria using the hardness value for the nearest downstream classified segment, as listed in the agency's Implementation Procedures, as amended. Where no value is provided in the Implementation Procedures, a hardness value of 50 mg/l CaCO3 shall be used. When applicable, the person shall convert total metal concentrations in surface water or groundwater to dissolved concentrations as described in the agency's Implementation Procedures, as amended. The person may use the basin-specific pH values provided in §307.6, Table 2 of this title, as amended, relevant to the particular affected property for purposes of determining the appropriate values for the pH dependent criteria. The person shall use the total suspended solids concentration for the nearest classified segment, as listed in the agency's Implementation Procedures, as amended.
Cont'd...