| (1) In accordance with §101.4 of this title (relating to Nuisance), as amended, the person may be required by the executive director to address COCs which present objectionable odors. (2) The maximum total soil concentration of COCs which are liquid at standard temperature and pressure shall not exceed 10,000 mg/kg within the soil interval of 0-10 feet, unless it can be demonstrated that: (A) no free liquids (e.g., no mobile NAPL) or sludges exist; or (B) higher concentrations do not adversely impair surface use of the affected property. (3) Other scientifically valid published criteria such as, but not limited to, non-COC specific secondary MCLs for water may be required by the executive director to be used as the RBEL. (j) Requirements for variance to default RBEL exposure factors. (1) Under Tiers 2 or 3 as provided in §350.75 of this title (relating to Tiered Human Health Protective Concentration Level Evaluation) and with prior executive director approval, the person may vary the following default exposure factors shown in the figures in subsections (a) and (c) of this section based on conditions or exposure levels at a particular affected property and in accordance with the conditions specified. A person shall provide the supporting documentation to justify the use of such alternative factors to the executive director. (A) Gastrointestinal absorption fraction (ABS GI ). A person or the executive director may use an alternative scientifically justifiable gastrointestinal absorption fraction value. Only in cases where the gastrointestinal absorption fraction is less than 50% shall the oral slope factor and oral reference dose be adjusted using equation RBEL-2 as shown in the figure in subsection (a) of this section, as applicable, to calculate the corresponding dermal slope factor and dermal reference dose. The person shall not use the gastrointestinal absorption fraction to modify the oral slope factor or oral reference dose for any exposure pathway other than the dermal exposure pathway. In the event the executive director determines a more scientifically valid gastrointestinal absorption fraction, that fraction shall be presumed to be the appropriate fraction and the person shall use that fraction unless a person rebuts that value with a scientifically valid study or by other credible published authority. (B) Dermal absorption fraction (ABS.d). A person or the executive director may conduct a scientifically valid study using property-specific soils or may use alternative scientifically justifiable dermal absorption values. In the event the executive director determines a more scientifically valid dermal absorption fraction, that fraction shall be presumed to be the appropriate fraction and the person shall use that fraction unless a person rebuts that fraction with a scientifically valid study using property-specific soils or by other credible published authority. (C) Relative bioavailability factor (RBAF). A person or the executive director may conduct a scientifically valid bioavailability study using property-specific soils or may conduct mineralogical evaluations of the chemical form of a COC present in soils at the affected property. In the event the executive director determines a more scientifically valid relative bioavailability factor, that factor shall be presumed to be the appropriate relative bioavailability factor and the person shall use that factor unless a person rebuts that factor with a scientifically valid bioavailability study using property-specific soils, mineralogical evaluation of the chemical form of a chemical of concern present in soils at the affected property, or by other credible published authority. (2) Under Tiers 2 or 3 as provided in §350.75 of this title (relating to Tiered Human Health Protective Concentration Level Evaluation), a person may request that the executive director allow a variance to the following default commercial/industrial exposure factors for the affected property as shown in the figure in subsection (a) of this section: averaging time for noncarcinogens (AT.w), exposure duration (ED.w), and exposure frequency (EF.w). This shall only be allowed for facilities that have or will have, as a condition of the approval of this variance, restricted property access. The executive director shall not delegate this decision to agency staff. (A) The person shall submit information to the executive director which demonstrates that variance from the default exposure factors is supported by property-specific information; historical, current, and probable future land use; redevelopment potential; and compatibility with surrounding land use. The person shall also provide written concurrence from the landowner for the placement of the institutional control in the county deed records, as required in subparagraph (L) of this paragraph, unless the property is subject to zoning or governmental ordinance which is equivalent to the deed notice, VCP certificate of completion or restrictive covenant that otherwise would have been required. (B) The person requesting such variance shall provide public notification as described in subparagraphs (D) and (E) of this paragraph for any request to vary the default exposure factors at the same time that variance-based PCLs are submitted to the executive director for approval. If the natural physical condition of the on-site commercial/industrial area for which the variance is sought essentially prohibits full commercial/industrial use (e.g., marshes and cliffs), and the variance would not necessitate a lesser commercial/industrial use of that area, then the executive director will determine the need for public notice on a site-specific basis for the prohibited use area. The person may request the executive director or his staff to review the variance-based PCLs or the variance request for completeness (e.g., administratively complete, mathematical accuracy, compliance with other PCL development procedures) in advance of initiating the public notification process. The required public notice shall be completed prior to consideration of the variance request for approval by the executive director. The public notice provisions may be performed in conjunction with or as part of another public participation/notification process required for permitting or other applicable state or federal statute or regulation provided the requirements of subparagraph (E) of this paragraph are also met. Additionally, an alternative mechanism that may exist under the other public participation/notification process which effectively provides broad public notice of the variance request, such as notification to an existing citizens advisory board for the affected property/facility, may substitute for the requirements of subparagraph (D) of this paragraph, provided the completion of the notification is sufficiently documented. (C) The notice shall contain, at a minimum, the following information: (i) the name, address and telephone number of the person requesting the variance; (ii) the address and the physical description for the location of the property and the agency case designation number; (iii) the modified value(s) the person seeks to use and the associated default exposure factor(s) as shown in the figure in subsection (a) of this section without any statements or other indications that such variance has been approved or otherwise considered favorably by the executive director or the executive director's staff other than that it has been reviewed for completeness; (iv) a clear and concise explanation as to the effect the variance will have on the future use of the subject property and on surrounding properties; (v) a statement that more detailed information regarding the variance request is available for review at the agency's central office in Austin, Texas, 8:00 am - 5:00 pm Monday thru Friday; and (vi) a notice to the public of the opportunity to submit written information, within 30 calendar days after the date of the initial published notice (publish the actual date), to the executive director which demonstrates that the proposal for variance from the default exposure factors would be compatible or incompatible with existing neighboring land uses and preservation of the active and productive land use of the subject property. (D) The notice shall be published in a newspaper distributed daily, if available, and generally circulated in the county or area where the property is located. The notice shall be published once a week for three weeks, with at least one of the notices appearing in a Sunday edition, if available. (E) The notice shall be sent to the following persons in clauses (i)-(viii) of this subparagraph by certified mail, return receipt requested: (i) all adjacent landowners; (ii) the local municipality planning board or similar governmental unit, if applicable; (iii) local taxing authorities; (iv) the mayor and health authorities of the city in which the property is located, if applicable; (v) the county judge and county health authority of the county in which the property is located; (vi) the agency's Public Interest Council; Cont'd... |
