Texas Administrative Code › Title 30 - ENVIRONMENTAL QUALITY › Part 1 - TEXAS COMMISSION ON ENVIRONMENTAL QUALITY › Chapter 335 - INDUSTRIAL SOLID WASTE AND MUNICIPAL HAZARDOUS WASTE › Subchapter S - RISK REDUCTION STANDARDS › Section 335.559 - Medium Specific Requirements and Adjustments for Risk Reduction Standard Number 2

Current through Reg. 49, No. 28; July 12, 2024
(a) Numeric cleanup
				  levels. The subsections (b) - (h) of this section specify requirements that can
				  define or modify numeric cleanup levels such as MSCs or require non-health
				  based criteria to be addressed.
(b)
				  Surface water. In determining the necessity for remediation at the facility,
				  persons shall utilize Chapter 307 of this title (relating to Texas Surface
				  Water Quality Standards) or, if those values are not available, Maximum
				  Contaminant Levels (MCLs) promulgated under the Safe Drinking Water Act, or if
				  MCLs are not available or appropriate, MSCs based upon human ingestion of the
				  water. Any discharge or release into or adjacent to surface water, including
				  storm water runoff, occurring during or after attainment of Risk Reduction
				  Standard Number 2, shall be compliant with the Texas Surface Water Quality
				  Standards of Chapter 307 of this title and may be subject to the permitting
				  requirements of Chapter 305 of this title (relating to Consolidated Permits) or
				  other authorization from the commission.
(c) Air. In determining the necessity for
				  remediation at the facility, persons shall observe limitations established by
				  the National Ambient Air Quality Standards (NAAQS) and the National Emission
				  Standards for Hazardous Air Pollutants (NESHAPS) as found in the 40 Code of
				  Federal Regulations (CFR) Parts 50 and 61, respectively, and other applicable
				  federal standards and guidelines of the EPA. Also, limitations established by
				  the commission under the Texas Clean Air Act, the state implementation plan or
				  other federal requirements must be observed. Permit requirements, limitations
				  established by standard exemptions, or other requirements of the commission
				  relative to atmospheric emissions and/or air quality may also apply.
(d) Groundwater. The groundwater cleanup
				  levels shall be determined by a consideration of the following.
(1) For residential exposure, the
				  concentration of a contaminant dissolved in groundwater must not exceed the
				  MCL, if promulgated pursuant the Federal Safe Drinking Water Act, §141,
				  otherwise the water MSC for ingestion determined pursuant to §
											335.556
				  of this title (relating to Determination of Cleanup Levels for Risk Reduction
				  Standard Number 2). Phase-separated non-aqueous liquids released from the unit
				  that is undergoing closure or remediation must be removed or
				  decontaminated.
(2) For
				  nonresidential exposure, the concentration of a contaminant dissolved in
				  groundwater must not exceed the MCL if promulgated pursuant to the Federal Safe
				  Drinking Water Act, §141. If no MCL has been promulgated, the groundwater
				  concentration shall not exceed the water MSC for ingestion determined pursuant
				  to §
											335.556
				  of this title, which has been multiplied by a factor of 3.36 for carcinogens or
				  2.8 for systemic toxicants to account for lower ingestion rates associated with
				  nonresidential worker exposure. Persons must be able to demonstrate that the
				  quality of groundwater at the facility property boundary will be protective for
				  residential exposure. Phase-separated non-aqueous liquids released from the
				  unit that is undergoing closure or remediation must be removed or
				  decontaminated to the extent practicable.
(3) For residential and non-residential
				  exposure, if the groundwater at the facility or area has a naturally occurring
				  background total dissolved solids concentration greater than 10,000 milligrams
				  per liter, the cleanup level for a contaminant dissolved in this groundwater
				  determined pursuant to paragraph (1) or (2) of this subsection, as appropriate,
				  may be adjusted by multiplying by 100. The resulting value becomes the maximum
				  concentration for groundwater for residential and non-residential exposure,
				  respectively.
(4) The executive
				  director may require the evaluation of additional exposure pathways or
				  environmental receptors as part of the adjustment of paragraph (3) of this
				  subsection.