Illinois Administrative Code › Title 35 - ENVIRONMENTAL PROTECTION › Part 1100 - CLEAN CONSTRUCTION OR DEMOLITION DEBRIS FILL OPERATIONS AND UNCONTAMINATED SOIL FILL OPERATIONS › Subpart F - STANDARDS FOR UNCONTAMINATED SOIL USED AS FILL MATERIAL AT FILL OPERATIONS REGULATED BY THIS PART › Section 1100.605 - Maximum Allowable Concentrations for Chemical Constituents in Uncontaminated Soils

Current through Register Vol. 48, No. 28, July 12, 2024
a) Except as
				provided for background concentrations in subsection (b), the maximum allowable
				concentrations for chemical constituents in uncontaminated soil must be
				determined pursuant to this subsection (a).
1) The maximum allowable concentration for a
				chemical constituent in uncontaminated soil will be the lowest Tier 1
				chemical-specific soil value of the exposure routes for residential and
				construction worker receptors set forth in 35 Ill. Adm. Code 742.Appendix B,
				Tables A and B (e.g., soil ingestion exposure route, outdoor inhalation
				exposure route, soil component of the groundwater ingestion exposure route,
				construction worker exposure route). Class I values must be used when
				determining the lowest Tier 1 chemical-specific value for the soil component of
				the groundwater ingestion exposure route. Before making the comparison among
				exposure routes to determine the lowest value for ionizing organic chemical
				constituents and inorganic chemical constituents, the requirements of
				subsections (a)(2) and (a)(3) must be satisfied, as applicable.
2) For ionizing organic constituents, the
				lowest pH-dependent value for the soil component of the Class I groundwater
				ingestion exposure route in 35 Ill. Adm. Code 742.Appendix B, Table C between
				column range 6.25 to 6.64 and column range 8.75 to 9.0 must be substituted for
				the pH-neutral value provided for the soil component of the Class I groundwater
				ingestion exposure route in 35 Ill. Adm. Code 742.Appendix B, Table A before
				determining the lowest Tier 1 chemical-specific soil value pursuant to
				subsection (a)(1) of this Section.
3) For inorganic constituents, the
				remediation objectives for the soil component of the Class I groundwater
				ingestion exposure route in Appendix B, Tables A and B are based on the
				contaminant concentration resulting from an extraction test and are not
				directly comparable to the remediation objectives provided for the ingestion
				and inhalation exposure routes, which are based on total concentrations. The
				following values, based on total concentrations, must be substituted for the
				extraction test values in Table A before determining the lowest Tier 1
				chemical-specific soil value pursuant to subsection (a)(1) of this Section:
A) The lowest chemical-specific, pH-dependent
				value for the soil component of the Class I groundwater ingestion exposure
				route in 35 Ill. Adm. Code 742.Appendix B, Table C between column range 6.25 to
				6.64 and column range 8.75 to 9.0; or
B) For inorganic constituents that are listed
				in 35 Ill. Adm. Code 742.Appendix B, Table A but not in Appendix B, Table C,
				the extraction test values for the soil component of the groundwater ingestion
				exposure route in Appendix B, Table A may be multiplied by 20 (i.e., 20
				liters/kilogram, the liquid to solid ratio in the extraction test assuming
				complete constituent leaching) to enable direct comparison with the ingestion
				and inhalation exposure route values. The resulting value must be substituted
				for the extraction test value before determining the lowest Tier 1
				chemical-specific soil value pursuant to subsection (a)(1) of this
				Section.
4) If the
				lowest Tier 1 soil value for a chemical is less than the Acceptable Detection
				Limit (ADL), the ADL will serve as the lowest soil value.
5) The total concentration of organic
				contaminants may not exceed the attenuation capacity of the soil as determined
				in accordance with 35 Ill. Adm. Code
				742.215(b)(1)
				and (b)(1)(A) using a default value of 2000
				mg/kg for the natural organic carbon fraction
				(foc).