| (2) The person shall apply the human health criteria
to protect drinking water and fisheries as provided in Table 3 of §307.6
of this title, as amended. 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 shall determine the applicability
of human health criteria according to the water body uses (e.g., public
water supply, sustainable fishery, incidental fishery, and contact
recreation) in accordance with the procedures contained in §307.3
and §307.6 of this title, as amended, and the Implementation Procedures, as amended. When
a water body is not being evaluated as a drinking water source, the
person must determine the necessity to evaluate exposure pathways
associated with contact recreation such as incidental ingestion of
surface water and dermal contact with surface water. The person shall
use the total suspended solids concentration for the nearest classified
segment, as listed in the agency's Implementation
Procedures, as amended.
(3) The person shall apply the effluent limitations
specified in Texas Pollutant Discharge Elimination System (TPDES)
General Permit Number TXG830000, as amended, for any release of groundwater
or storm water that has been impacted by petroleum fuel (as defined
in the general permit).
(4) The person shall apply United States Environmental
Protection Agency guidelines or alternate provisions in accordance
with §307.6(c)(7) of this title, as amended, when criteria for
aquatic life protection are not provided for a COC in §307.6
of this title, Table 1, as amended. In addition, the person shall
apply federal guidance criteria (i.e., lower of a federal numerical
criterion, MCL, or equivalent state drinking water guideline) or alternate
provisions in accordance with §307.6(d)(8) of this title, as
amended, when human health criteria for a COC are not provided in
Table 3 of §307.6 of this title, as amended.
(5) The person shall apply the numerical criteria,
as appropriate, for chlorides, sulfates, total dissolved solids, and
pH for classified segments as specified in §307.10(1) of this
title (relating to Appendices A - G ), as amended.
(6) The person may apply additional provisions where
data on surface water quality for a specific surface water body at
the affected property is available or can be reasonably obtained.
(A) The person may determine property-specific hardness,
based on sampling data, for calculating metals criteria in accordance
with the procedures contained in the agency's Implementation
Procedures, as amended.
(B) The person may determine property-specific total
suspended solids, based on sampling data, for estimating ''dissolved''
metals in accordance with the Implementation
Procedures, as amended.
(C) The person may determine the actual pH of the particular
surface water body at the affected property.
(7) The additional numeric and narrative criteria listed
in subparagraphs (A) and (B) of this paragraph may require development
of a surface water RBEL (e.g., where a nutrient is a COC) or modification
to the surface water RBEL (e.g., lower a RBEL value to minimize foaming
on the water's surface) determined pursuant to paragraphs (1) - (5)
of this subsection.
(A) General criteria related to aesthetic parameters,
nutrient parameters, and salinity in accordance with §307.4(b),
(e), and (g) of this title , as amended.
(B) General provisions related to the preclusion of
adverse toxic effects on aquatic and terrestrial life, livestock,
or domestic animals in accordance with §307.6(b) of this title,
as amended.
(8) If the executive director determines that the release
has the potential to lower the surface water dissolved oxygen, then
the executive director may require the person to apply the dissolved
oxygen criteria for classified segments specified in §307.10(1)
of this title, as amended, or the dissolved oxygen criteria for unclassified
waters specified in §307.10(4) of this title, as amended, §307.4(h)
of this title, as amended, and §307.7(b)(3)(A) of this title
(relating to Site Specific Uses and Criteria), as amended.
(i) Aesthetics. For COCs for which a RBEL cannot be
calculated by the procedures of this section, or the RBEL concentration
for the COC otherwise adversely impacts environmental quality or public
welfare and safety, presents objectionable characteristics (e.g.,
taste, odor), or makes a natural resource unfit for use, the person
shall comply with paragraphs (1) - (3) of this subsection as appropriate.
For response actions which are triggered for an area solely for purposes
of this subsection (i.e., there is no other human health or ecological
hazard remaining), the executive director will evaluate the seriousness,
probable longevity of the matter, and suitability of the proposed
remedy with the landowner in order to site-specifically determine
whether or not institutional controls and financial assurance are
warranted. The person shall provide all information reasonably necessary
to support such a determination to the executive director. The default
presumption is that financial assurance and institutional controls
are required for exposure prevention remedies. If the executive director
determines that institutional controls and financial assurance are
not warranted, then persons shall not be required to comply with the
provisions of §§350.31(g), 350.33(e)(2)(C) and 350.111(b)(3)
or (6) of this title (relating to General Requirements for Remedy
Standards; Remedy Standard B; and Use of Institutional Controls),
specifically relating to the physical control matters for the portion
of affected property with the aesthetics issue.
(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 (ABSGI ). 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.
Cont'd... |
