Illinois Administrative Code
Title 35 - ENVIRONMENTAL PROTECTION
Part 742 - TIERED APPROACH TO CORRECTIVE ACTION OBJECTIVES
Subpart H - TIER 2 GROUNDWATER EVALUATION
Section 742.812 - J&E Groundwater Equations for the Indoor Inhalation Exposure Route
Current through Register Vol. 48, No. 38, September 20, 2024
Groundwater remediation objectives for the indoor inhalation exposure route are calculated using the modified J&E model as described in Section 742.717, except as follows:
a) In Equation J&E9a, the total number of layers of soil that contaminants migrate through from the source to the building shall include a capillary fringe layer.
b) The thickness of the capillary fringe layer is 37.5 cm.
c) The volumetric water content of the capillary fringe shall be 90% of the total porosity of the soil that comprises the capillary fringe.
d) Equations J&E7 and J&E8 calculate an acceptable groundwater remediation objective.
e) A groundwater remediation objective that exceeds the water solubility of that chemical (refer to Appendix C, Table E for solubility values) is not allowed. If the calculated groundwater remediation objective is greater than the water solubility of that chemical, then the solubility is used as the groundwater remediation objective.