SECTION 350.32. Remedy Standard A

(a) To attain Remedy Standard A, the person shall within a reasonable time frame given the particular circumstances of an affected property:

(1) Remove any listed hazardous waste as defined in 40 Code of Federal Regulations Part 261, Subpart D, as amended, which is contained within a waste management facility component (e.g., tank, surface impoundment, etc.) or which is separable from environmental media using simple mechanical removal processes;

(2) Remove and/or decontaminate any waste or environmental media which is characteristically hazardous due to ignitability, corrosivity, reactivity, or toxicity characteristic as defined in 40 Code of Federal Regulations Part 261, Subpart C, as amended;

(3) Remove and/or decontaminate the surface soil, subsurface soil, and groundwater PCLE zones, other environmental media, and non-hazardous waste to achieve COC concentration levels below the residential or commercial/industrial critical PCLs, as applicable; and

(4) Demonstrate the affected property is protective for ecological receptors.

(b) Response actions under Remedy Standard A must result in permanent risk reduction at an affected property.

(1) The person shall not use physical controls under Remedy Standard A.

(2) The person shall remediate the affected property such that the concentration of COCs in surface soil, subsurface soil, groundwater, and other environmental media do not exceed the applicable critical PCLs.

(3) Remedial alternatives, including the use of monitored natural attenuation as a decontamination remedy, must be capable of achieving the Remedy Standard A objectives within a reasonable time frame, given the particular circumstances at the affected property; and must be appropriate considering the hydrogeologic characteristics of the affected property, COC characteristics, and the potential for unprotective exposure conditions to continue or result during the remedial period. The executive director may require a demonstration of the appropriateness of a remedy in the context of the above-mentioned criteria for any remedy, regardless of the status of self-implementation as allowed in subsection (d) of this section. If the executive director requires such a demonstration, the person is not required to await executive director approval to proceed with self-implementation; however, if the executive director determines that the self-implementing response action is inappropriate based on these criteria, then the executive director shall require appropriate response actions to be taken.

(c) The person shall determine the PCLs for Remedy Standard A using exposure pathways where the human or ecological receptor comes into contact with the COCs directly within, above, or below a source medium. Lateral transport considerations which place the POE at a location outside of the source area cannot be used to determine PCLs for Remedy Standard A, with the exception that, when necessary, the person shall perform lateral transport calculations to determine whether PCLs calculated based upon on-site commercial/industrial workers are protective of off-site residents.

(d) Remedy Standard A is a self-implementing standard unless the person desires to modify exposure factors under §350.74(j) of this title (relating to Development of Risk-Based Exposure Limits) which requires prior executive director approval, or unless the person chooses not to self-implement. The person shall submit a SIN to the executive director and the agency's office in the region where the affected property is located at least 10 days prior to conducting a response action under this remedy standard. The person may then perform the response action without receiving the executive director's approval, unless such prior approval is required by another agency rule, order, or permit. If the person chooses not to self-implement, then the person shall submit a RAP for review and approval by the executive director. The person shall include an APAR with the RAP unless an APAR has previously been submitted.

(e) The person cannot use a demonstration of technical impracticability when responding to soil and/or groundwater PCLE zones, or other affected environmental media under Remedy Standard A.

(f) The person shall prevent COCs at concentrations above the critical groundwater PCLs from migrating beyond the existing boundary of the groundwater PCLE zone.

(g) There are no post-response action care or financial assurance requirements for Remedy Standard A response actions, provided the person adequately documents attainment of the response objectives provided in subsection (a) of this section. When considered warranted, the executive director may require the person to monitor environmental media to verify that the models used to determine PCLs established under Tiers 2 or 3 as provided in §350.75 of this title (relating to Tiered Human Health Protective Concentration Level Evaluation) yield protective PCLs.

Source Note: The provisions of this §350.32 adopted to be effective September 23, 1999, 24 TexReg 7436