Texas Administrative Code › Title 30 - ENVIRONMENTAL QUALITY › Part 1 - TEXAS COMMISSION ON ENVIRONMENTAL QUALITY › Chapter 350 - TEXAS RISK REDUCTION PROGRAM › Subchapter D - DEVELOPMENT OF PROTECTIVE CONCENTRATION LEVELS › Section 350.71 - General Requirements

Current through Reg. 49, No. 28; July 12, 2024
(a) This
				  subchapter describes separate tiered processes for establishing protective
				  concentration levels of COCs that can remain in the source medium and be
				  protective of human and ecological receptors at the point of exposure within
				  the exposure medium. The tiered process for the calculation of human health
				  protective concentration levels (PCLs) is set forth in §
										350.75
				  of this title (relating to Tiered Human Health Protective Concentration Level
				  Evaluation) and is structured conceptually in terms of Tiers 1, 2, and 3. Each
				  tier sets forth conditions to calculate PCLs and each successive tier
				  incrementally provides for more consideration of site-specificity and
				  sophistication in the PCL calculation process. The person can move through the
				  tiered process or start at any tier, but must conduct the cumulative check in
				  accordance with §
										350.72(b)
				  of this title (relating to Carcinogenic Risk Levels and Hazard Indices for
				  Human Health Exposure Pathways). The human health PCLs under Tiers 1, 2 and 3
				  are set based on the receptors and exposure pathways as specified in
				  subsections (b) and (c) of this section in consideration of the land use
				  classification of the affected property, the classification of groundwater, the
				  distribution of COCs in environmental media, and the presence of receptors. The
				  tiered process for ecological evaluations is different. Tier 1 is an exclusion
				  criteria checklist that is used to exclude sites which do not pose potential
				  ecological risk from further evaluation. If a site is not excluded from Tier 1,
				  then the person must further evaluate the site for ecological risk, and
				  possibly establish ecological PCLs are under Tiers 2 or 3. The lowest of the
				  human health and any applicable ecological PCLs determined for each COC for the
				  soil, groundwater, surface water, sediment, or air as required, and are then
				  respectively compared with representative concentrations of COCs in the soil,
				  groundwater, surface water, sediment, or air as appropriate to determine if the
				  PCLs are exceeded or not. If PCLs are exceeded for certain COCs, then PCLs may
				  be further evaluated under the respective tiered process and compared again to
				  representative site concentrations to determine if further action is needed;
				  otherwise a response action must be initiated. No further action is required
				  for those COCs which do not exceed the PCLs, and the cumulative criteria of
				  §
										350.72(b)
				  of this title.
(b) The person
				  shall:
(1) ensure PCLs are protective of
				  human health and the environment;
(2) determine human health PCLs based on
				  residential or commercial/industrial exposure as appropriate for the land use
				  of each affected on-site and off-site property;
(3) assume the human receptor is a resident
				  for residential property; and
(4)
				  assume the human receptor is a commercial/industrial worker for
				  commercial/industrial property.