ILLINOIS POLLUTION CONTROL BOARD
July 26, 2001
IN THE MATTER OF:
PROPOSED AMENDMENTS TO TIERED
APPROACH TO CORRECTIVE ACTION
OBJECTIVES (TACO): 35 ILL. ADM.
CODE 742
)
)
)
)
)
)
R00-19(B)
(Rulemaking – Land)
Adopted Rule. Final Order.
OPINION AND ORDER OF THE BOARD (by E.Z. Kezelis, N.J. Melas, R.C. Flemal):
By today’s order, the Board adopts amendments to the Tiered Approach to Corrective
Action Objectives (TACO) found at Part 742 of the Board’s land regulations (35 Ill. Adm. Code
742). The TACO rules were originally adopted by the Board on June 5, 1997, Tiered Approach
to Corrective Action Objectives (TACO): 35 Ill. Adm. Code 742, R97-12(A). Part 742 contains
procedures for developing remediation objectives based on risks to human health and the
environment posed by environmental conditions at sites undergoing remediation in the Site
Remediation Program, the Leaking Underground Storage Tank Program, and pursuant to
Resource Conservation and Recovery Act (RCRA) Part B permits and closures.
1
PROCEDURAL HISTORY
Background
On May 15, 2000, the Agency submitted proposed amendments to the TACO regulations.
The Board’s adoption of these amendments is authorized by Sections 27 and 28 of the
Environmental Protection Act (Act) (415 ILCS 5/27, 28 (1998)).
The Board moved the Agency’s proposal to first notice on July 27, 2000. In doing so, the
Board divided the proposal into two subdockets based upon subject matter. The Subdocket A
amendments, which were adopted by the Board on December 21, 2000 (Proposed Amendments
to Tiered Approach to Corrective Action Objectives (TACO): 35 Ill. Adm. Code 742, R00-
19(A)), created a new institutional control, known as the Environmental Land Use Control or
1
The TACO regulations provide for a three-tiered approach to cleanup objectives. Under a Tier
1 analysis, an applicant compares levels of contaminants of concern at the remediation site to
pre-determined remediation objectives. See Tiered Approach to Corrective Action Objectives
(TACO): 35 Ill. Adm. Code 742 (June 5, 1997), R97-12(A). For a Tier 2 analysis, an applicant
uses site-specific information and equations set forth in the rules to develop alternative
remediation objectives for contaminants of concern.
Id
. Finally, a Tier 3 analysis provides
greater flexibility by allowing an applicant to develop site-specific remediation objectives using
alternative parameters not found in Tier 1 or Tier 2.
Id
.
2
“ELUC,” and changed the acceptable background levels for arsenic found in Part 742, Appendix
A, Table G.
The Subdocket B amendments, which are adopted herein, were moved to second notice
by the Board on June 7, 2001. These amendments address several aspects of TACO that, with
the benefit of time and practical experience, were in need of clarification and correction. Many
of these amendments were made with the input and agreement of the regulated community.
The amendments that are adopted today have, with two notable exceptions, changed very
little from those that were originally proposed by the Board at first notice. The first exception
involves Appendix A, Table G, which was incorporated into Subdocket A, and was adopted by
the Board on December 21, 2000. The second exception involves the proposed cleanup
standards for methyl tertiary-butyl ether (MTBE), which were originally proposed in Appendix
A, Table A; Appendix B, Table A; Appendix B, Table B; Appendix B, Table E; Appendix B,
Table F; and Appendix C, Table E. The Board is not moving forward with the MTBE
amendments in this docket.
The Board has opened a separate Subdocket C for the purpose of addressing the proposed
MTBE amendments. See Proposed Amendments to Tiered Approach to Corrective Action
Objectives (TACO): 35 Ill. Adm. Code 742 (June 7, 2001), R00-19(C). By creating a separate
subdocket for MTBE, the Board intends to provide a concurrent examination of all MTBE-
related issues that are currently pending in this and other rulemaking proposals.
SUMMARY OF SUBDOCKET B AMENDEMENTS
As mentioned, there have been only a few minor changes to the rule from that proposed
by the Board in its first-notice opinion and order. Furthermore, additional explanation for certain
amendments can be found in the Board’s second-notice opinion and order which was adopted on
June 7, 2001. See Proposed Amendments to Tiered Approach to Corrective Action Objectives
(TACO): 35 Ill. Adm. Code 742 (June 7, 2001), R00-19(B). For purposes of this final opinion
and order, however, only those areas generating public interest or concern will be mentioned
again.
Section 742.225 Demonstration of Compliance with Remediation Objectives
The proposed change to Section 742.225 involved the addition of a new subsection (f),
which clarifies that “soil sample concentrations determined by laboratory tests for the purposes
of comparison to corrective action objectives should be normalized for moisture content by
calculating and reporting the soil concentration of contaminants on a dry soil weight basis.”
Agency Exh. 1 (O’Brien) at 2. According to the Agency, this amendment is intended to address
the potential variation in analyzing soil samples that are based on a saturated weight.
Id
. Soil
samples taken from the same location may vary from day to day depending on the moisture
content of the soil at the particular time the sample is collected, thereby making the saturated
weight results less reliable.
Id
. Additionally, the proposed dry weight measurement is consistent
with the analytical methods directed by the United States Environmental Protection Agency.
Id
.
3
The Agency proposed this amendment because it will result in greater consistency and accuracy
in sampling results.
Id
.
This amendment raised some concern both during hearing and in public comment.
Specifically, the Illinois Steel Group (ISG) urged the Board to reconsider adoption of this
proposed amendment.
While the Board appreciates ISG’s comments, the Board finds that the proposed
amendment will help ensure consistency in sampling procedures and in sampling results and will
not unduly prejudice the regulated community.
Potential Conflict with Other Proposed Amendments
Concerns were raised at hearing and in public comments regarding the potential conflict
between the TACO amendments and related portions of Title 35. At the time these comments
were made, the Board was awaiting the Agency’s proposed amendments to Part 732 (Petroleum
Underground Storage Tank Program) and Part 740 (Site Remediation Program) of Title 35.
After close of the public comment period and prior to the Board adopting its second-
notice opinion and order, the proposed amendments to Part 732 and Part 740 were filed. Except
for concerns regarding the proposed regulation of MTBE, the Board is confident that adoption of
the TACO amendments will not create a conflict with the Part 732 or Part 740 regulations.
Applicability of Adopted Amendments to Ongoing Remedial Activities
An important concern was also raised by ISG at hearing and in public comment.
Specifically, ISG is concerned about the applicability of these amendments to ongoing remedial
projects. PC 2 at 3.
Agreeing that this was an important concern, the Board clarified the applicability of these
amendments in its second notice opinion and order. Specifically, the Board recognizes that the
TACO standards are not self-implementing, but are implemented through a variety of cleanup
programs, including Site Remediation Program (SRP), Leaking Underground Storage Tank
(LUST), and Resource Conservation and Recovery Act (RCRA) closure permits. Within these
programs, there are a variety of plans for which Agency approval is required, including, but not
limited to, a remedial action plan (SRP), a corrective action plan (LUST), and a RCRA Part B
permit. Other Agency approvals are also necessary at various stages of a cleanup under each of
these programs. Because the TACO standards are not self-implementing, they can only be
applied to ongoing remediation sites in accordance with the relevant cleanup program and any
challenges to their applicability would also proceed under the specific procedures established for
the particular cleanup program.
Accordingly, the Board concludes that the applicability of the TACO amendments, once
adopted, must be governed by the relevant program’s rules. Should a program participant
challenge their applicability to a particular cleanup in the future, the Board will consider the
challenge in the context of that particular case and that program’s particular rules.
4
ORDER
The Board hereby adopts these amendments to the TACO regulations. Accordingly, the
Board directs the Clerk to file the following adopted amendments with the Secretary of State.
TITLE 35: ENVIRONMENTAL PROTECTION
SUBTITLE G: WASTE DISPOSAL
CHAPTER I: POLLUTION CONTROL BOARD
SUBCHAPTER f: RISK BASED CLEANUP OBJECTIVES
PART 742
TIERED APPROACH TO CORRECTIVE ACTION OBJECTIVES
SUBPART A: INTRODUCTION
Section
742.100
Intent and Purpose
742.105
Applicability
742.110
Overview of Tiered Approach
742.115
Key Elements
742.120
Site Characterization
SUBPART B: GENERAL
Section
742.200
Definitions
742.205
Severability
742.210
Incorporations by Reference
742.215
Determination of Soil Attenuation Capacity
742.220
Determination of Soil Saturation Limit
742.225
Demonstration of Compliance with Remediation Objectives
742.230
Agency Review and Approval
SUBPART C: EXPOSURE ROUTE EVALUATIONS
Section
742.300
Exclusion of Exposure Route
742.305
Contaminant Source and Free Product Determination
742.310
Inhalation Exposure Route
742.315
Soil Ingestion Exposure Route
742.320
Groundwater Ingestion Exposure Route
SUBPART D: DETERMINING AREA BACKGROUND
Section
5
742.400
Area Background
742.405
Determination of Area Background for Soil
742.410
Determination of Area Background for Groundwater
742.415
Use of Area Background Concentrations
SUBPART E: TIER 1 EVALUATION
Section
742.500
Tier 1 Evaluation Overview
742.505
Tier 1 Soil and Groundwater Remediation Objectives
742.510
Tier 1 Remediation Objectives Tables
SUBPART F: TIER 2 GENERAL EVALUATION
Section
742.600
Tier 2 Evaluation Overview
742.605
Land Use
742.610
Chemical and Site Properties
SUBPART G: TIER 2 SOIL EVALUATION
Section
742.700
Tier 2 Soil Evaluation Overview
742.705
Parameters for Soil Remediation Objective Equations
742.710
SSL Soil Equations
742.715
RBCA Soil Equations
742.720
Chemicals with Cumulative Noncarcinogenic Effects
SUBPART H: TIER 2 GROUNDWATER EVALUATION
Section
742.800
Tier 2 Groundwater Evaluation Overview
742.805
Tier 2 Groundwater Remediation Objectives
742.810
Calculations to Predict Impacts from Remaining Groundwater Contamination
SUBPART I: TIER 3 EVALULATIONEVALUATION
Section
742.900
Tier 3 Evaluation Overview
742.905
Modifications of Parameters
742.910
Alternative Models
742.915
Formal Risk Assessments
742.920
Impractical Remediation
742.925
Exposure Routes
742.930
Derivation of Toxicological Data
6
SUBPART J: INSTITUTIONAL CONTROLS
Section
742.1000
Institutional Controls
742.1005
No Further Remediation Letters
742.1010
Environmental Land Use Controls
742.1012
Federally Owned Property: Land Use Control Memorandums of Agreement
742.1015
Ordinances
742.1020
Highway Authority Agreements
SUBPART K: ENGINEERED BARRIERS
Section
742.1100
Engineered Barriers
742.1105
Engineered Barrier Requirements
APPENDIX A
General
ILLUSTRATION A
Developing Soil Remediation Objectives Under the Tiered Approach
ILLUSTRATION B
Developing Groundwater Remediation Objectives Under the Tiered
Approach
TABLE A
Soil Saturation Limits (C
sat
) for Chemicals Whose Melting Point is Less than
30
?
C
TABLE B
Tolerance Factor (K)
TABLE C
Coefficients {A
N-I+1
} for W Test of Normality, for N=2(1)50
TABLE D
Percentage Points of the W Test for Nn=3(1)50
TABLE E
Similar-Acting Noncarcinogenic Chemicals
TABLE F
Similar-Acting Carcinogenic Chemicals
TABLE G
Concentrations of Inorganic Chemicals in Background Soils
TABLE H
Chemicals Whose Tier 1 Class I Groundwater Remediation Objective Exceeds
the 1 in 1,000,000 Cancer Risk Concentration
APPENDIX B
Tier 1 Tables and Illustrations
ILLUSTRATION A
Tier 1 Evaluation
TABLE A
Tier 1 Soil Remediation Objectives for Residential Properties
TABLE B
Tier 1 Soil Remediation Objectives for Industrial/Commercial Properties
TABLE C
pH Specific Soil Remediation Objectives for Inorganics and Ionizing Organics
for the Soil Component of the Groundwater Ingestion Route (Class I
Groundwater)
TABLE D
pH Specific Soil Remediation Objectives for Inorganics and Ionizing Organics
for the Soil Component of the Groundwater Ingestion Route (Class II
Groundwater)
TABLE E
Tier 1 Groundwater Remediation Objectives for the Groundwater Component of
the Groundwater Ingestion Route
TABLE F
Values Used to Calculate the Tier 1 Soil Remediation Objectives for the Soil
Component of the Groundwater Ingestion Route
7
APPENDIX C
Tier 2 Tables and Illustrations
ILLUSTRATION A
Tier 2 Evaluation for Soil
ILLUSTRATION B
Tier 2 Evaluation for Groundwater
ILLUSTRATION C
US Department of Agriculture Soil Texture Classification
TABLE A
SSL Equations
TABLE B
SSL Parameters
TABLE C
RBCA Equations
TABLE D
RBCA Parameters
TABLE E
Default Physical and Chemical Parameters
TABLE F
Methods for Determining Physical Soil Parameters
TABLE G
Error Function (erf)
TABLE H
Q/C Values By Source Area
TABLE I
K
oc
Values for Ionizing Organics as a Function of pH (cm
3
/g or L/kg or
cm3water/g
soil
) cm
3
water
/g
soil
)
TABLE J
Values to be Substituted for K
d
or K
s
ks k
d
or k
s
when Evaluating Inorganics as a
Function of pH (cm3/g cm
3
/g or L/kg or cm
3
water/g
soil
cm
3
water
/g
soil
)
TABLE K Parameter Estimates for Calculating Water-Filled Soil Porosity (
?
w
)
AUTHORITY: Implementing Sections 22.4, 22.12, Title XVI, and Title XVII and authorized by
Sections 27, 57.14, and 58.5 of the Environmental Protection Act [415 ILCS 5/22.4, 22.12, 27,
57.14 and 58.5 and Title XVI and Title XVII].
SOURCE: Adopted in R97-12(A) at 21 Ill. Reg. 7942, effective July 1, 1997; amended in R97-
12(B) at 21 Ill. Reg. 16391, effective December 8, 1997; amended in R97-12(C) at 22 Ill. Reg.
10847, effective June 8, 1998; amended in R00-19(B) at 24 25 Ill. Reg. _______, effective
____________________.
NOTE:
Capitalization indicates statutory language.
SUBPART B: GENERAL
Section 742.210
Incorporations by Reference
a)
The Board incorporates the following material by reference:
ASTM. American Society for Testing and Materials, 1916 Race Street,
Philadelphia, PA 19103 (215) 299-5400.
ASTM D 2974-87, Standard Test Methods for Moisture, Ash and Organic
Matter of Peat and Other Organic Soils, approved May 29, 1987
(reapproved 1995).
ASTM D 2488-93, Standard Practice for Description and Identification of
Soils (Visual-Manual Procedure), approved September 15, 1993.
ASTM D 1556-90, Standard Test Method for Density and Unit Weight of
Soil in Place by the Sand-Cone Method, approved June 29, 1990.
8
ASTM D 2167-94, Standard Test Method for Density and Unit Weight of
Soil in Place by the Rubber Balloon Method, approved March 15, 1994.
ASTM D 2922-91, Standard Test Methods for Density of Soil and Soil-
Aggregate in Place by Nuclear Methods (Shallow Depth), approved
December 23, 1991.
ASTM D 2937-94, Standard Test Method for Density of Soil in Place by
the Drive-Cylinder Method, approved June 15, 1994.
ASTM D 854-92, Standard Test Method for Specific Gravity of Soils,
approved November 15, 1992.
ASTM D 2216-92, Standard Method for Laboratory Determination of
Water (Moisture) Content of Soil and Rock, approved June 15, 1992.
ASTM D 4959-89, Standard Test Method for Determination of Water
(Moisture) Content of Soil by Direct Heating Method, approved June 30,
1989 (reapproved 1994).
ASTM D 4643-93, Standard Test Method for Determination of Water
(Moisture) Content of Soil by the Microwave Oven Method, approved
July 15, 1993.
ASTM D 5084-90, Standard Test Method for Measurement of Hydraulic
Conductivity of Saturated Porous Materials Using a Flexible Wall
Permeameter, approved June 29, 1990.
ASTM D 422-63, Standard Test Method for Particle-Size Analysis of
Soils, approved November 21, 1963 (reapproved 1990).
ASTM D 1140-92, Standard Test Method for Amount of Material in Soils
Finer than the No. 200 (75
?
m) Sieve, approved November 15, 1992.
ASTM D 3017-88, Standard Test Method for Water Content of Soil and
Rock in Place by Nuclear Methods (Shallow Depth), approved May 27,
1988.
ASTM D 4525-90, Standard Test Method for Permeability of Rocks by
Flowing Air, approved May 25, 1990.
ASTM D 2487-93, Standard Test Method for Classification of Soils for
Engineering Purposes, approved September 15, 1993.
ASTM E 1527-93, Standard Practice for Environmental Site Assessments:
Phase I Environmental Site Assessment Process, approved March 15,
1993. Vol. 11.04.
9
ASTM E 1739-95, Standard Guide for Risk-Based Corrective Action
Applied at Petroleum Release Sites, approved September 10, 1995.
Barnes, Donald G. and Dourson, Michael. (1988). Reference Dose (RfD):
Description and Use in Health Risk Assessments. Regulatory Toxicology and
Pharmacology. 8, 471-486.
GPO. Superintendent of Documents, U.S. Government Printing Office,
Washington, DC 20401, (202) 783-3238.
USEPA Guidelines for Carcinogenic Risk Assessment, 51 Fed. Reg.
33992-34003 (September 24, 1986).
"Test Methods for Evaluating Solid Waste, Physical/Chemical Methods",
USEPA Publication number SW-846 (Third Edition, Final Update III,
December 1996Final Update IIIA, April 1998), as amended by Updates I,
IIA, and III, and IIIA (Document No. 955-001-00000-1)(contact USEPA,
Office of Solid Waste, for Update III).
"Methods for the Determination of Organic Compounds in Drinking
Water", EPA Publication No. EPA/600/4-88/039 (December 1988
(Revised July 1991)).
"Methods for the Determination of Organic Compounds in Drinking
Water, Supplement II", EPA Publication No. EPA/600/R-92/129 (August
1992).
"Methods for the Determination of Organic Compounds in Drinking
Water, Supplement III", EPA Publication No. EPA/600/R-95/131 (August
1995).
IRIS. Integrated Risk Information System, National Center for Environmental
Assessment, U.S. Environmental Protection Agency, 26 West Martin Luther King
Drive, MS-190, Cincinnati, OH 45268, (513) 569-7254.
"Reference Dose (RfD): Description and Use in Health Risk
Assessments", Background Document 1A (March 15, 1993).
"EPA Approach for Assessing the Risks Associated with Chronic
Exposures to Carcinogens", Background Document 2 (January 17, 1992).
Nelson, D.W., and L.E. Sommers. (1982). Total carbon, organic carbon, and
organic matter. In: A.L. Page (ed.), Methods of Soil Analysis. Part 2. Chemical
and Microbiological Properties. 2nd Edition, pp. 539-579, American Society of
Agronomy. Madison, WI.
NTIS. National Technical Information Service, 5285 Port Royal Road,
Springfield, VA 22161, (703) 487-4600.
10
"Dermal Exposure Assessment: Principles and Applications", EPA
Publication No. EPA/600/8-91/011B (January 1992).
"Exposure Factors Handbook", EPA Publication No. EPA/600/8-89/043
(July 1989).
"Risk Assessment Guidance for Superfund, Vol. I; Human Health
Evaluation Manual, Supplemental Guidance: Standard Default Exposure
Factors", OSWER Directive 9285.6-03 (March 1991).
"Rapid Assessment of Exposure to Particulate Emissions from Surface
Contamination Sites," EPA Publication No. EPA/600/8-85/002 (February
1985), PB 85-192219.
"Risk Assessment Guidance for Superfund, Volume I; Human Health
Evaluation Manual (Part A)", Interim Final, EPA Publication No.
EPA/540/1-89/002 (December 1989).
"Risk Assessment Guidance for Superfund, Volume I; Human Health
Evaluation Manual, Supplemental Guidance, Dermal Risk Assessment
Interim Guidance", Draft (August 18, 1992).
"Soil Screening Guidance: Technical Background Document", EPA
Publication No. EPA/540/R-95/128, PB 96-963502 (May 1996).
"Soil Screening Guidance: User's Guide", EPA Publication No.
EPA/540/R-96/018, PB 96-963505 (April 1996).
"
Superfund Exposure Assessment Manual", EPA Publication No.
EPA/540/1-88/001 (April 1988).
RCRA Facility Investigation Guidance, Interim Final, developed by USEPA
(EPA 530/SW-89-031), 4 volumes (May 1989).
b)
CFR (Code of Federal Regulations). Available from the Superintendent of
Documents, U.S. Government Printing Office, Washington, D.C. 20402
(202)783-3238:
40 CFR 761.120 (19931998).
c)
This Section incorporates no later editions or amendments.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______ , effective _____________)
Section 742.220
Determination of Soil Saturation Limit
a)
For any organic contaminant that has a melting point below 30
o
C, the remediation
objective for the inhalation exposure route developed under Tier 2 or Tier 3 shall
11
not exceed the soil saturation limit, as determined under subsection (c) of this
Section.
b)
For any organic contaminant, the remediation objective under Tier 2 or Tier 3 for
the soil component of the groundwater ingestion exposure route shall not exceed
the soil saturation limit, as determined under subsection (c) of this Section.
c)
The soil saturation limit shall be:
1)
The value listed in Appendix A, Table A for that specific contaminant;
2)
A value derived from Equation S29 in Appendix C, Table A; or
3)
A value derived from another method approved by the Agency.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ______________)
Section 742.225
Demonstration of Compliance with Remediation Objectives
Compliance is achieved if each sample result does not exceed that respective remediation
objective unless a person elects to proceed under subsections (c), (d) and (e) of this Section.
a)
Compliance with groundwater remediation objectives developed under Subparts
D through F and H through I shall be demonstrated by comparing the contaminant
concentrations of discrete samples at each sample point to the applicable
groundwater remediation objective. Sample points shall be determined by the
program under which remediation is performed.
b)
Unless the person elects to composite samples or average sampling results as
provided in subsections (c) and (d) of this Section, compliance with soil
remediation objectives developed under Subparts D through G and I shall be
demonstrated by comparing the contaminant concentrations of discrete samples to
the applicable soil remediation objective.
1)
Except as provided in subsections (c) and (d) of this Section, compositing
of samples is not allowed.
2)
Except as provided in subsections (c) and (d) of this Section, averaging of
sample results is not allowed.
3)
Notwithstanding subsections (c) and (d) of this Section, compositing of
samples and averaging of sample results is not allowed for the
construction worker population.
4)
The number of sampling points required to demonstrate compliance is
determined by the requirements applicable to the program under which
remediation is performed.
12
c)
If a person chooses to composite soil samples or average soil sample results to
demonstrate compliance relative to the soil component of the groundwater
ingestion exposure route, the following requirements apply:
1)
A minimum of two sampling locations for every 0.5 acre of contaminated
area is required, with discrete samples at each sample location obtained at
every two feet of depth, beginning at six inches below the ground surface
and continuing through the zone of contamination. Alternatively, a
sampling method may be approved by the Agency based on an
appropriately designed site-specific evaluation. Samples obtained at or
below the water table shall not be used in compositing or averaging.
2)
For contaminants of concern other than volatile organic contaminants:
A)
Discrete samples from the same boring may be composited.
B)
Discrete sample results from the same boring may be averaged.
3)
For volatile organic contaminants:
A)
Compositing of samples is not allowed.
B)
Discrete sample results from the same boring may be averaged.
d)
If a person chooses to composite soil samples or average soil sample results to
demonstrate compliance relative to the inhalation exposure route or ingestion
exposure route, the following requirements apply:
1)
A person shall submit a sampling plan for Agency approval, based upon a
site-specific evaluation;
2)
For volatile organic compounds, compositing of samples is not allowed;
and
3)
All samples shall be collected within the contaminated area.
e)
When averaging under this Section, if no more than 50% of sample results are
reported as "non-detect", "no contamination", "below detection limits", or similar
terms, such results shall be included in the averaging calculation as one-half of the
reported analytical detection limit for the contaminant. However, when
performing a test for normal or lognormal distribution for the purpose of
calculating a 95% Upper Confidence Limit of the mean for a contaminant, a
person may substitute for each non-detect value a randomly generated value
between, but not including, zero and the reported analytical detection limit. If
more than 50% of sample results are "non-detect", another statistically valid
procedure approved by the Agency may be used to determine an average.
13
f)
All soil samples collected after August 15, 2001, shall be reported on a dry weight
basis for the purpose of demonstrating compliance, with the exception of the
TCLP and SPLP and the property pH.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ____________)
SUBPART C: EXPOSURE ROUTE EVALUATIONS
Section 742.300
Exclusion of Exposure Route
a)
This Subpart sets forth requirements to demonstrate that an actual or potential
impact to a receptor or potential receptor from a contaminant of concern can be
excluded from consideration from one or more exposure routes. If an evaluation
under this Part Subpart demonstrates the applicable requirements for excluding an
exposure route are met, then the exposure route is excluded from consideration
and no remediation objective(s) need be developed for that exposure route.
b)
No exposure route may be excluded from consideration until characterization of
the extent and concentrations of contaminants of concern at a site has been
performed. The actual steps and methods taken to characterize a site shall be
determined by the specific program requirements under which the site
remediation is being addressed.
c)
As an alternative to the use of the requirements in this Part Subpart, a person may
use the procedures for evaluation of exposure routes under Tier 3 as set forth in
Section 742.925.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ______________)
Section 742.305
Contaminant Source and Free Product Determination
No exposure route shall be excluded from consideration relative to a contaminant of concern
unless the following requirements are met:
a)
The sum of the concentrations of all organic contaminants of concern shall not
exceed the attenuation capacity of the soil as determined under Section 742.215;
b)
The concentrations of any organic contaminants of concern remaining in the soil
shall not exceed the soil saturation limit as determined under Section 742.220;
c)
Any soil which contains contaminants of concern shall not exhibit any of the
characteristics of reactivity for hazardous waste as determined under 35 Ill. Adm.
Code 721.123;
d)
Any soil which contains contaminants of concern shall not exhibit a pH less than
or equal to 2.0 or greater than or equal to 12.5, as determined by SW-846 Method
9040B: pH Electrometric for soils with 20% or greater aqueous (moisture) content
14
or by SW-846 Method 9045C: Soil pH for soils with less than 20% aqueous
(moisture) content as incorporated by reference in Section 742.210; and
e)
Any soil which contains contaminants of concern in the following list of inorganic
chemicals or their salts shall not exhibit any of the characteristics of toxicity for
hazardous waste as determined by 35 Ill. Adm. Code 721.124, or an alternative
method approved by the Agency: arsenic, barium, cadmium, chromium, lead,
mercury, selenium or silver; and.
f)
If contaminants of concern include polychlorinated biphenyls (PCBs), the
concentration of any PCBs in the soil shall not exceed 50 parts per million as
determined by SW-846 Methods.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ______________)
Section 742.310
Inhalation Exposure Route
The inhalation exposure route may be excluded from consideration if:
a)
The requirements of Sections 742.300 and 742.305 are met; and
b)
An institutional control, in accordance with Subpart J, is in place that meets the
following requirements:
1)
Either:
A)
The concentration of any contaminant of concern within ten feet of
the land surface or within ten feet of any man-made pathway shall
not exceed the Tier 1 remediation objective under Subpart E for
the inhalation exposure route; or
B)
An engineered barrier, as set forth in Subpart K and approved by
the Agency, is in place; and
2)
Requires safety precautions for the construction worker if the Tier 1
construction worker remediation objectives are exceeded.
b)
An approved engineered barrier is in place that meets the requirements of Subpart
K;
c)
Safety precautions for the construction worker are taken if the Tier 1 construction
worker remediation objectives are exceeded; and
d)
An institutional control, in accordance with Subpart J, will be placed on the
property.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ______________)
15
Section 742.315
Soil Ingestion Exposure Route
The soil ingestion exposure route may be excluded from consideration if:
a)
The requirements of Sections 742.300 and 742.305 are met; and
b)
An institutional control, in accordance with Subpart J, is in place that meets the
following requirements:
1)
Either:
A)
The concentration of any contaminant of concern within three feet
of the land surface shall not exceed the Tier 1 remediation
objective under Subpart E for the ingestion of soil exposure route;
or
B)
An engineered barrier, as set forth in Subpart K and approved by
the Agency, is in place; and
2)
Requires safety precautions for the construction worker if the Tier 1
construction worker remediation objectives are exceeded.
b)
An approved engineered barrier is in place that meets the requirements of Subpart
K;
c)
Safety precautions for the construction worker are taken if the Tier 1 construction
worker remediation objectives are exceeded; and
d)
An institutional control, in accordance with Subpart J, will be placed on the
property.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective _______________)
SUBPART F: TIER 2 GENERAL EVALUATION
Section 742.605
Land Use
a)
Present and post-remediation land use is evaluated in a Tier 2 evaluation.
Acceptable exposure factors for the Tier 2 evaluation for residential,
industrial/commercial, and construction worker populations are provided in the
far right column of both Appendix C, both Tables B and D. Use of exposure
factors different from those in Appendix C, Tables B and D must be approved by
the Agency as part of a Tier 3 evaluation.
b)
If a Tier 2 evaluation is based on an industrial/commercial property use, then:
1)
Construction worker populations shall also be evaluated; and
2)
Institutional controls are required in accordance with Subpart J.
16
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective _______________)
SUBPART G: TIER 2 SOIL EVALUATION
Section 742.700
Tier 2 Soil Evaluation Overview
a)
Tier 2 remediation objectives are developed through the use of models which
allow site-specific data to be considered. Appendix C, Tables A and C list
equations that shall be used under a Tier 2 evaluation to calculate soil remediation
objectives prescribed by SSL and RBCA models, respectively. (See also
Appendix C, Illustration A.)
b)
Appendix C, Table A lists equations that are used under the SSL model. (See also
Appendix C, Illustration A.) The SSL model has equations to evaluate the
following human exposure routes:
1)
Soil ingestion exposure route;
2)
Inhalation exposure route for:
A)
Volatiles Organic contaminants;
B)
Fugitive dust; and
3)
Soil component of the groundwater ingestion exposure route.
c)
Evaluation of the dermal exposure route is not required under the SSL model.
d)
Appendix C, Table C lists equations that are used under the RBCA model. (See
also Appendix C, Illustration A.) The RBCA model has equations to evaluate
human exposure based on the following:
1)
The combined exposure routes of inhalation of vapors and particulates,
soil ingestion and dermal contact with soil;
2)
The ambient vapor inhalation (outdoor) route from subsurface soils;
3)
Soil component of the groundwater ingestion route; and
4)
Groundwater ingestion exposure route.
e)
The equations in either Appendix C, Table A or C may be used to calculate
remediation objectives for each contaminant of concern under Tier 2, if the
following requirements are met:
1)
The Tier 2 soil remediation objectives for the ingestion and inhalation
exposure routes shall use the applicable equations from the same approach
(i.e., SSL equations in Appendix C, Table C).
17
2)
The equations used to calculate soil remediation objectives for the soil
component of the groundwater ingestion exposure route are not dependent
on the approach utilized to calculate soil remediation objectives for the
other exposure routes. For example, it is acceptable to use the SSL
equations for calculating Tier 2 soil remediation objectives for the
ingestion and inhalation exposure routes, and the RBCA equations for
calculating Tier 2 soil remediation objectives for the soil component of the
groundwater ingestion exposure route.
3)
Combining equations from Appendix C, Tables A and C to form a new
model is not allowed. In addition, Appendix C, Tables A and C must use
their own applicable parameters identified in Appendix C, Tables B and
D, respectively.
f)
In calculating soil remediation objectives for industrial/commercial property use,
applicable calculations shall be performed twice: once using
industrial/commercial population default values and once using construction
worker population default values. The more stringent soil remediation objectives
derived from these calculations must be used for further Tier 2 evaluations.
g)
Tier 2 data sheets provided by the Agency shall be used to present calculated Tier
2 remediation objectives, if required by the particular program for which
remediation is being performed.
h)
The RBCA equations which rely on the parameter Soil Water Sorption
Coefficient (k
s
) can only be used for ionizing organics and inorganics by
substituting values for k
s
from Appendix C, Tables I and J, respectively. This will
also require the determination of a site-specific value for soil pH.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ______________)
Section 742.710
SSL Soil Equations
a)
This Section sets forth the equations and parameters used to develop Tier 2 soil
remediation objectives for the three exposure routes using the SSL approach.
b)
Soil Ingestion Exposure Route
1)
Equations S1 through S3 form the basis for calculating Tier 2 remediation
objectives for the soil ingestion exposure route using the SSL approach.
Equation S1 is used to calculate soil remediation objectives for
noncarcinogenic contaminants. Equations S2 and S3 are used to calculate
soil remediation objectives for carcinogenic contaminants for residential
populations and industrial/commercial and construction worker
populations, respectively.
2)
For Equations S1 through S3, the SSL default values cannot be modified
with site-specific information.
18
c)
Inhalation Exposure Route
1)
Equations S4 through S16, S26 and S27 are used to calculate Tier 2 soil
remediation objectives for the inhalation exposure route using the SSL
approach. To address this exposure route, volatiles organic contaminants
and mercury must be evaluated separately from fugitive dust using their
own equations set forth in subsections (c)(2) and (c)(3) of this Section,
respectively.
2)
Volatiles Organic Contaminants
A)
Equations S4 through S10 are used to calculate Tier 2 soil
remediation objectives for volatile organic contaminants and
mercury based on the inhalation exposure route. Equation S4 is
used to calculate soil remediation objectives for noncarcinogenic
volatile organic contaminants in soil for residential and
industrial/commercial populations. Equation S5 is used to
calculate soil remediation objectives for noncarcinogenic volatile
organic contaminants and mercury in soil for construction worker
populations. Equation S6 is used to calculate soil remediation
objectives for carcinogenic volatile organic contaminants in soil
for residential and industrial/commercial populations. Equation S7
is used to calculate soil remediation objectives for carcinogenic
volatile organic contaminants in soil for construction worker
populations. Equations S8 through S10, S27 and S28 are used for
calculating numerical values for some of the parameters in
Equations S4 through S7.
B)
For Equation S4, a numerical value for the Volatilization Factor
(VF) can be calculated in accordance with subsection (c)(2)(F) of
this Section. The remaining parameters in Equation S4 have either
SSL default values listed in Appendix C, Table B or toxicological-
specific information (i.e., RfC), which can be obtained from IRIS
or requested from the program under which the remediation is
being performed.
C)
For Equation S5, a numerical value for the Volatilization Factor
adjusted for Agitation (VF') can be calculated in accordance with
subsection (c)(2)(G) of this Section. The remaining parameters in
Equation S5 have either SSL default values listed in Appendix C,
Table B or toxicological-specific information (i.e., RfC), which
can be obtained from IRIS or requested from the program under
which the remediation is being performed.
D)
For Equation S6, a numerical value for VF can be calculated in
accordance with subsection (c)(2)(F) of this Section. The
remaining parameters in Equation S6 have either default values
19
listed in Appendix C, Table B or toxicological-specific information
(i.e., URF), which can be obtained from IRIS or requested from the
program under which the remediation is being performed.
E)
For Equation S7, a numerical value for VF' can be calculated in
accordance with subsection (c)(2)(G) of this Section. The
remaining parameters in Equation S7 have either default values
listed in Appendix C, Table B or toxicological-specific information
(i.e., URF), which can be obtained from IRIS or requested from the
program under which the remediation is being performed.
F)
The VF can be calculated for residential and industrial/commercial
populations using one of the following equations based on the
information known about the contaminant source and receptor
population:
i)
Equation S8, in conjunction with Equation S10, is used to
calculate VF assuming an infinite source of contamination;
or
ii)
If the area and depth of the contaminant source are known
or can be estimated reliably, mass limit considerations may
be used to calculate VF using Equation S26.
G)
The VF' can be calculated for the construction worker populations
using one of the following equations based on the information
known about the contaminant source:
i)
Equation S9 is used to calculate VF' assuming an infinite
source of contamination; or
ii)
If the area and depth of the contaminant source are known
or can be estimated reliably, mass limit considerations may
be used to calculate VF' using Equation S27.
3)
Fugitive Dust
A)
Equations S11 through S16 are used to calculate Tier 2 soil
remediation objectives using the SSL fugitive dust model for the
inhalation exposure route. Equation S11 is used to calculate soil
remediation objectives for noncarcinogenic contaminants in
fugitive dust for residential and industrial/commercial populations.
Equation S12 is used to calculate soil remediation objectives for
noncarcinogenic contaminants in fugitive dust for construction
worker populations. Equation S13 is used to calculate soil
remediation objectives for carcinogenic contaminants in fugitive
dust for residential and industrial/commercial populations.
Equation S14 is used to calculate soil remediation objectives for
20
carcinogenic contaminants in fugitive dust for construction worker
populations. Equations S15 and S16 are used for calculating
numerical quantities for some of the parameters in Equations S11
through S14.
B)
For Equation S11, a numerical value can be calculated for the
Particulate Emission Factor (PEF) using Equation S15. This
equation relies on various input parameters from a variety of
sources. The remaining parameters in Equation S11 have either
SSL default values listed in Appendix C, Table B or toxicological-
specific information (i.e., RfC), which can be obtained from IRIS
or requested from the program under which the remediation is
being performed.
C)
For Equation S12, a numerical value for the Particulate Emission
Factor for Construction Worker (PEF') can be calculated using
Equation S16. The remaining parameters in Equation S12 have
either SSL default values listed in Appendix C, Table B or
toxicological-specific information (i.e., RfC), which can be
obtained from IRIS or requested from the program under which the
remediation is being performed.
D)
For Equation S13, a numerical value for PEF can be calculated
using Equation S15. The remaining parameters in Equation S13
have either default values listed in Appendix C, Table B or
toxicological-specific information (i.e., URF), which can be
obtained from IRIS or requested from the program under which the
remediation is being performed.
E)
For Equation S14, a numerical value for PEF' can be calculated
using Equation S16. The remaining parameters in Equation S14
have either default values listed in Appendix C, Table B or
toxicological-specific information (i.e., URF), which can be
obtained from IRIS or requested from the program under which the
remediation is being performed.
d)
Soil Component of the Groundwater Ingestion Exposure Route
The Tier 2 remediation objective for the soil component of the groundwater
ingestion exposure route can be calculated using one of the following equations
based on the information known about the contaminant source and receptor
population:
1)
Equation S17 is used to calculate the remediation objective assuming an
infinite source of contamination.
A)
The numerical quantities for four parameters in Equation S17, the
Target Soil Leachate Concentration (C
w
), Soil-Water Partition
21
Coefficient (K
d
) for non-ionizing organics, Water-Filled Soil
Porosity (
?
w
) Theta
w
(
?
w
) and Air-Filled Soil Porosity (
?
a
) Theta
a
(
?
a
), are calculated using Equations S18, S19, S20 and S21,
respectively. Equations S22, S23, S24 and S25 are also needed to
calculate numerical values for Equations S18 and S21. The pH-
dependent K
d
values for ionizing organics can be calculated using
Equation S19 and the pH-dependent K
oc
values in Appendix C,
Table I.
B)
The remaining parameters in Equation S17 are Henry's Law
Constant (H'), a chemical specific value listed in Appendix C,
Table E and Dry Soil Bulk Density (
?
b
), a site-specific based value
listed in Appendix C, Table B.
C)
The default value for GW
obj
is the Tier 1 groundwater objective.
For chemicals for which there is no Tier 1 groundwater
remediation objective, the value for GW
obj
shall be the Health
Advisory concentration determined according to the procedures
specified in 35 Ill. Adm. Code 620, Subpart F. As an alternative to
using Tier 1 groundwater remediation objectives or Health
Advisory concentrations determined according to the procedures
specified in 35 Ill. Adm. Code 620, Subpart F., GW
obj
may be
developed using Equations R25 and R26, if approved institutional
controls are in place as required in Subpart J.
2)
If the area and depth of the contaminant source are known or can be
estimated reliably, mass limit considerations may be used to calculate the
remediation objective for this exposure route using Equation S28. The
parameters in Equation S28 have default values listed in Appendix C,
Table B.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ________________)
Section 742.715
RBCA Soil Equations
a)
This Section presents the RBCA model and describes the equations and
parameters used to develop Tier 2 soil remediation objectives.
b)
Ingestion, Inhalation, and Dermal Contact
1)
The two sets of equations in subsections (b)(2) and (b)(3) of this Section
shall be used to generate Tier 2 soil remediation objectives for the
combined ingestion, inhalation, and dermal contact with soil exposure
routes.
2)
Combined Exposure Routes of Soil Ingestion, Inhalation of Vapors and
Particulates, and Dermal Contact with Soil
22
A)
Equations R1 and R2 form the basis for deriving Tier 2
remediation objectives for the set of equations that evaluates the
combined exposure routes of soil ingestion, inhalation of vapors
and particulates, and dermal contact with soil using the RBCA
approach. Equation R1 is used to calculate soil remediation
objectives for carcinogenic contaminants. Equation R2 is used to
calculate soil remediation objectives for noncarcinogenic
contaminants. Soil remediation objectives for the ambient vapor
inhalation (outdoor) route from subsurface soils must also be
calculated in accordance with the procedures outlined in subsection
(b)(3) of this Section and compared to the values generated from
Equations R1 or R2. The smaller value (i.e., R1 and R2 compared
to R7 and R8, respectively) from these calculations is the Tier 2
soil remediation objective for the combined exposure routes of soil
ingestion, inhalation, and dermal contact with soil.
B)
In Equation R1, numerical values are calculated for two
parameters:
i)
The volatilization factor for surficial soils (VF
ss
) using
Equations R3 and R4; and
ii)
The volatilization factor for subsurface soils regarding
particulates (VF
p
) using Equation R5.
C)
VF
ss
uses Equations R3 and R4 to derive a numerical value.
Equation R3 requires the use of Equation R6. Both equations must
be used to calculate the VF
ss
. The lowest calculated value from
these equations must be substituted into Equation R1.
D)
The remaining parameters in Equation R1 have either default
values listed in Appendix C, Table D or toxicological-specific
information (i.e., SF
o
, SF
i
), which can be obtained from IRIS or
requested from the program under which the remediation is being
performed.
E)
For Equation R2, the parameters VF
ss
and VF
p
are calculated. The
remaining parameters in Equation R2 have either default values
listed in Appendix C, Table D or toxicological-specific
information (i.e., RfD
o
, RfD
i
), which can be obtained from IRIS or
requested from the program under which the remediation is being
performed.
F)
For chemicals other than inorganics which do not have default
values for the dermal absorption factor (RAF
d
) in Appendix C,
Table D, a dermal absorption factor of 0.5 shall be used for
23
Equations R1 and R2. For inorganics, dermal absorption may be
disregarded (i.e., RAF
d
= 0).
3)
Ambient Vapor Inhalation (outdoor) route from Subsurface Soils (soil
below one meter)
A)
Equations R7 and R8 form the basis for deriving Tier 2
remediation objectives for the ambient vapor inhalation (outdoor)
route from subsurface soils using the RBCA approach. Equation
R7 is used to calculate soil remediation objectives for carcinogenic
contaminants. Equation R8 is used to calculate soil remediation
objectives for noncarcinogenic contaminants.
B)
For Equation R7, the carcinogenic risk-based screening level for
air (RBSL
air
) and the volatilization factor for soils below one meter
to ambient air (VF
samb
) have numerical values that are calculated
using Equations R9 and R11, respectively. Both equations rely on
input parameters from a variety of sources.
C)
The noncarcinogenic risk-based screening level for air (RBSL
air
)
and the volatilization factor for soils below one meter to ambient
air (VF
samb
) in Equation R8 have numerical values that can be
calculated using Equations R10 and R11, respectively.
c)
Soil Component of the Groundwater Ingestion Exposure Route
1)
Equation R12 forms the basis for deriving Tier 2 remediation objectives
for the soil component of the groundwater ingestion exposure route using
the RBCA approach. The parameters, groundwater at the source
(GW
source
) and Leaching Factor (LF
sw
), have numerical values that are
calculated using Equations R13 and R14, respectively.
2)
Equation R13 requires numerical values that are calculated using Equation
R15.
3)
Equation R14 requires numerical values that are calculated using
Equations R21, R22, and R24. For non-ionizing organics, the Soil Water
Sorption Coefficient k
s
shall be calculated using Equation R20. For
ionizing organics and inorganics, the values for (k
s
) are listed in Appendix
C, Tables I and J, respectively. The pH-dependent k
s
values for ionizing
organics can be calculated using Equation R20 and the pH-dependent K
oc
values in Appendix C, Table I. The remaining parameters in Equation
R14 are field measurements or default values listed in Appendix C, Table
D.
d)
The default value for GW
comp
is the Tier 1 groundwater remediation objective.
For chemicals for which there is no Tier 1 groundwater remediation objective, the
value for GW
comp
shall be the Health Advisory concentration determined
24
according to the procedures specified in 35 Ill. Adm. Code 620, Subpart F. As an
alternative to using the Tier 1 groundwater remediation objectives or Health
Advisory above concentrations, GW
comp
may be developed using Equations R25
and R26, if approved institutional controls are in place as may be required in
Subpart J.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective _______________)
SUBPART H: TIER 2 GROUNDWATER EVALUATION
Section 742.805
Tier 2 Groundwater Remediation Objectives
a)
To develop a groundwater remediation objective under this Section that exceeds
the applicable Tier 1 groundwater remediation objective, or for which there is no
Tier I groundwater remediation objective, a person may request approval from the
Agency if the person has performed the following:
1)
Identified the horizontal and vertical extent of groundwater for which the
Tier 2 groundwater remediation objective is sought;
2)
Taken corrective action, to the maximum extent practicable to remove
any free product;
3)
Using Equation R26 in accordance with Section 742.810, demonstrated
that the concentration of any contaminant of concern in groundwater will
meet:
A)
The applicable Tier 1 groundwater remediation objective at the
point of human exposure; or
B)
For any contaminant of concern for which there is no Tier 1
groundwater remediation objective, the Health Advisory
concentration determined according to the procedures specified in
35 Ill. Adm. Code 620, Subpart F at the point of human exposure.
A person may request the Agency to provide these concentrations
or may propose these concentrations under Subpart I;
4)
Using Equation R26 in accordance with Section 742.810, demonstrated
that the concentration of any contaminant of concern in groundwater
within the minimum or designated maximum setback zone of an existing
potable water supply well will meet the applicable Tier 1 groundwater
remediation objective or, if there is no Tier 1 groundwater remediation
objective, the Health Advisory concentration determined according to the
procedures specified in 35 Ill. Adm. Code 620. A person may request the
Agency to provide these concentrations or may propose these
concentrations under Subpart I;
25
5)
Using Equation R26 in accordance with Section 742.810, demonstrated
that the concentration of any contaminant of concern in groundwater
discharging into a surface water will meet the applicable water quality
standard under 35 Ill. Adm. Code 302;
6)
Demonstrated that the source of the release is not located within the
minimum or designated maximum setback zone or within a regulated
recharge area of an existing potable water supply well; and
7)
If the selected corrective action includes an engineered barrier as set forth
in Subpart K to minimize migration of contaminant of concern from the
soil to the groundwater, demonstrated that the engineered barrier will
remain in place for post-remediation land use through an institutional
control as set forth in Subpart J.
b)
A groundwater remediation objective that exceeds the water solubility of that
chemical (refer to Appendix C, Table E for solubility values) is not allowed.
c)
The contaminants of concern for which a Tier 1 remediation objective has been
developed shall be included in any mixture of similar-acting chemicals under
consideration in Tier 2. The evaluation of 35 Ill. Adm. Code 620.615 regarding
mixtures of similar-acting chemicals shall be considered satisfied for Class I
groundwater at the point of human exposure if either of the following
requirements are achieved:
1)
Calculate the weighted average using the following equations:
a
CUOx
a
CUOx
CUOx
CUOx
ave
x
x
x
x
W
?
?
?
?
?
...
3
2
2
1
1
3
where:
W
ave
= Weighted Average
x
1
through x
a
=
Concentration of each individual contaminant at the
location of concern. Note that, depending on the target organ, the actual
number of contaminants will range from 2 to 14.
CUOx
a
=
A Tier 1 or Tier 2 remediation objective must be developed
for each x
a
.
iA)
If the value of the weighted average calculated in accordance with
the equations above is less than or equal to 1.0, then the
remediation objectives are met for those chemicals.
iiB)
If the value of the weighted average calculated in accordance with
the equations above is greater than 1.0, then additional remediation
must be carried out until the level of contaminants remaining in the
26
remediated area have a weighted average calculated in accordance
with the equation above less than or equal to one; or
2)
Divide each individual chemical's remediation objective by the number of
chemicals in that specific target organ group that were detected at the site.
Each of the contaminant concentrations at the site is then compared to the
remediation objectives that have been adjusted to account for this potential
additivity.
d)
The evaluation of 35 Ill. Adm. Code 620.615 regarding mixtures of similar-acting
chemicals are considered satisfied if the cumulative risk from any contaminant(s)
of concern listed in Appendix A, Table H, plus any other contaminant(s) of
concern detected in groundwater and listed in Appendix A, Table F as affecting
the same target organ/organ system as the contaminant(s) of concern detected
from Appendix A, Table H, does not exceed 1 in 10,000.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective _______________)
Section 742.810
Calculations to Predict Impacts from Remaining Groundwater
Contamination
a)
Equation R26 predicts the contaminant concentration along the centerline of a
groundwater plume emanating from a vertical planar source in the aquifer
(dimensions S
w
wide and S
d
deep). This model accounts for both three-
dimensional dispersion (x is the direction of groundwater flow, y is the other
horizontal direction, and z is the vertical direction) and biodegradation.
1)
The parameters in this equation are:
X =
distance from the planar source to the location of concern,
along the centerline of the groundwater plume (i.e., y=0,
z=0)
C
x
=
the concentration of the contaminant at a distance X from
the source, along the centerline of the plume
C
source
=
the greatest potential concentration of the contaminant of
concern in the groundwater at the source of the
contamination, based on the concentrations of contaminants
in groundwater due to the release and the projected
concentration of the contaminant migrating from the soil to
the groundwater. As indicated above, the model assumes a
planar source discharging groundwater at a concentration
equal to C
source
.
?
x
=
dispersivity in the x direction (i.e., Equation R16)
?
y
=
dispersivity in the y direction (i.e., Equation R17)
27
?
z
=
dispersivity in the z direction (i.e., Equation R18)
U =
specific discharge (i.e., actual groundwater flow velocity
through a porous medium; takes into account the fact that
the groundwater actually flows only through the pores of
the subsurface materials) where the aquifer hydraulic
conductivity (K), the hydraulic gradient (I) and the total
soil porosity
?
T
must be known (i.e., Equation R19)
?
=
first order degradation constant obtained from Appendix C,
Table E or from measured groundwater data
S
w
=
width of planar groundwater source in the y direction
S
d
=
depth of planar groundwater source in the z direction
2)
The following parameters are determined through field measurements: U,
K, I,
?
T
, S
w
, S
d
.
A)
The determination of values for U, K, I and
?
T
can be obtained
through the appropriate laboratory and field techniques;
B)
From the immediate down-gradient edge of the source of the
groundwater contamination values for S
w
and S
d
shall be
determined. S
w
is defined as the width of groundwater at the
source which exceeds the Tier 1 groundwater remediation
objective. S
d
is defined as the depth of groundwater at the source
which exceeds the Tier 1 groundwater remediation objective; and
C)
Total soil porosity can also be calculated using Equation R23.
b)
Once values are obtained for all the input parameters identified in subsection (a)
of this Section, the contaminant concentration C
x
along the centerline of the
plume at a distance X from the source shall be calculated such so that X is the
distance from the down-gradient edge of the source of the contamination at the
site to the point where the contaminant concentration is equal to the Tier 1
groundwater remediation objective or Health Advisory concentration determined
according to the procedures specified in 35 Ill. Adm. Code 620, Subpart F.
1)
If there are any potable water supply wells located within the calculated
distance X, then the Tier 1 groundwater remediation objective or
concentration shall be met at the edge of the minimum or designated
maximum setback zone of the nearest potable water supply down-gradient
of the source. If there are any potable water supply wells located within
the calculated distance X, then the Tier 1 groundwater remediation
objective or Health Advisory concentration shall be met at the edge of the
minimum or designated maximum setback zone of the nearest potable
28
water supply down-gradient of the source. If no potable water supply
wells exist within the calculated distance X, then it can be determined that
no existing potable water supply wells are adversely impacted. To
demonstrate that a minimum or maximum setback zone of a potable water
supply well will not be impacted above the applicable Tier 1 groundwater
remediation objective or concentration determined according to the
procedures specified in 35 Ill. Adm. Code 620, Subpart F, X shall be the
distance from the C
source
location to the edge of the setback zone.
2)
To demonstrate that no surface water is adversely impacted, X shall be the
distance from the down-gradient edge of the source of the contamination
at the site to the nearest surface water body. This calculation must show
that the contaminant in the groundwater at this location (C
x
) does not
exceed the applicable water quality standard.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ______________)
SUBPART I: TIER 3 EVALUATION
Section 742.900
Tier 3 Evaluation Overview
a)
Tier 3 sets forth a flexible framework to develop remediation objectives outside of
the requirements of Tiers 1 and 2. Although Tier 1 and Tier 2 evaluations are not
prerequisites to conduct Tier 3 evaluations, data from Tier 1 and Tier 2 can assist
in developing remediation objectives under a Tier 3 evaluation.
b)
The level of detail required to adequately characterize a site depends on the
particular use of Tier 3. Tier 3 can require additional investigative efforts beyond
those described in Tier 2 to characterize the physical setting of the site. However,
in situations where remedial efforts have simply reached a physical obstruction
additional investigation may not be necessary for a Tier 3 submittal.
c)
Situations that can be considered for a Tier 3 evaluation include, but are not
limited to:
1)
Modification of parameters not allowed under Tier 2;
2)
Use of models different from those used in Tier 2;
3)
Use of additional site data to improve or confirm predictions of exposed
receptors to contaminants of concern;
4)
Analysis of site-specific risks using formal risk assessment, probabilistic
data analysis, and sophisticated fate and transport models (e.g., requesting
a target hazard quotient greater than 1 or a target cancer risk greater than 1
in 1,000,000);
29
5)
Requests for site-specific remediation objectives because an assessment
indicates further remediation is not practical;
6)
Incomplete human exposure pathway(s) not excluded under Subpart C;
7)
Use of toxicological-specific information not available from the sources
listed in Tier 2;
8)
Land uses which are substantially different from the assumed residential
or industrial/commercial property uses of a site (e.g., a site will be used for
recreation in the future and cannot be evaluated in Tiers 1 or 2); and
9)
Requests for site-specific remediation objectives which exceed Tier 1
groundwater remediation objectives so long as the following is
demonstrated:
A)
To the extent practical, the exceedance of the groundwater quality
standard has been minimized and beneficial use appropriate to the
groundwater that was impacted has been returned; and
B)
Any threat to human health or the environment has been
minimized
. [415 ILCS 5/58.5(D)(4)(A)]
d)
For requests of a target cancer risk ranging between 1 in 1,000,000 and 1 in
10,000 at the point of human exposure or a target hazard quotient greater than 1 at
the point of human exposure, the requirements of Section 742.915 shall be
followed. Requests for a target cancer risk exceeding 1 in 10,000 at the point of
human exposure are not allowed.
e)
Requests for approval of a Tier 3 evaluation must be submitted to the Agency for
review under the specific program under which remediation is performed. When
reviewing a submittal under Tier 3, the Agency shall consider
whether the
interpretations and conclusions reached are supported by the information
gathered
. [415 ILCS 58.7(e)(1)]. The Agency shall approve a Tier 3 evaluation if
the person submits the information required under this Part and establishes
through such information that public health is protected and that specified risks to
human health and the environment have been minimized.
f)
If contaminants of concern include polychlorinated biphenyls (PCBs), requests for
approval of a Tier 3 evaluation must additionally address the applicability of 40
CFR 761.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ______________)
Section 742.925
Exposure Routes
Technical information may demonstrate that there is no actual or potential impact of
contaminants of concern to receptors from a particular exposure route. In these instances, a
30
demonstration excluding an exposure route shall be submitted to the Agency for review and
approval. A submittal under this Section shall include the following information:
a)
A description of the route evaluated;
b)
Technical support including a discussion of the natural or man-made barriers to
exposure through that route, and calculations, and modeling results A description
of the site and physical site characteristics;
c)
Physical and chemical properties of contaminants of concern A discussion of the
result and possibility of the route becoming active in the future; and
d)
Contaminant migration properties; Technical support that may include, but is not
limited to, the following:
1)
a discussion of the natural or man-made barriers to that exposure route;
2)
calculations and modeling;
3)
physical and chemical properties of contaminants of concern; and
4)
contaminant migration properties.
e)
Description of the site and physical site characteristics; and
f)
Discussion of the result and possibility of the route becoming active in the future;
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ________________)
SUBPART J: INSTITUTIONAL CONTROLS
Section 742.1005
No Further Remediation Letters
a)
A No Further Remediation Letter issued by the Agency under 35 Ill. Adm. Code
732 or 742 740 may be used as an institutional control under this Part if the
requirements of subsection (b) of this Section are met.
b)
A request for approval of a No Further Remediation Letter as an institutional
control shall meet the requirements applicable to the specific program under
which the remediation is performed.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ____________________)
Section 742.1015
Ordinances
a)
An ordinance adopted by a unit of local government that effectively prohibits the
installation of potable water supply wells (and the use of such wells) may be used
as an institutional control to meet the requirements of Section 742.320(d) or
742.805(a)(3) if the requirements of this Section are met. Ordinances prohibiting
31
the installation of potable water supply wells (and the use of such wells) that do
not expressly prohibit the installation of potable water supply wells (and the use
of such wells) by units of local government may be acceptable as institutional
controls if the requirements of this Section are met and a Memorandum of
Understanding (MOU) is entered into under subsection (i) of this Section.
b)
A request for approval of a local ordinance as an institutional control shall
provide the following:
1)
A copy of the ordinance restricting groundwater use certified by an
official of the unit of local government in which the site is located that it is
the latest, most current a true and accurate copy of the ordinance, unless
the Agency and the unit of local government have entered an agreement
under subsection (i) of this Section, in which case the request may
alternatively reference the MOU. The ordinance must demonstrate that
potable use of groundwater from potable water supply wells is prohibited;
2)
A scaled map(s) delineating the areal area and extent of groundwater
contamination (measured or modeled) above the applicable remediation
objectives including any measured data showing concentrations of
contaminants of concern in which the applicable remediation objectives
are exceeded;
3)
Information showing the concentration of contaminants of concern in
which the applicable remediation objectives are exceeded;
34)
A scaled map delineating the boundaries of all properties under which
groundwater is located which exceeds the applicable groundwater
remediation objectives;
45)
Information identifying the current owner(s) of each property identified in
subsection (b)(4) (b)(3) of this Section; and
56)
A copy of the proposed submission of the information to the current
owners identified in subsection (b)(5) (b)(4) of this Section of the
information required in subsections (b)(1) through (b)(5) (b)(4) of this
Section and proof that the notification required in subsection (c) of this
Section has been submitted. Within 45 days from the date the Agency's
Nno Ffurther Rremediation determination is recorded, the person who
requested to use the ordinance as an institutional control must submit
proof to the Agency of the notice to the property owners identified in
subsection (b)(4).
c)
Each of the property owners identified in subsection (b)(5) (b)(4) of this Section
and the unit of local government must receive written notification from the party
desiring to use the institutional control that groundwater remediation objectives
have been approved by the Agency. Written proof of this notification shall be
submitted to the Agency within 45 days from the date of the instrument
32
memorializing the Agency’s no further remediation determination is recorded.
The notification shall include:
1)
The name and address of the unit of local government;
2)
The citation to the ordinance;
3)
A description of the property being sent notice by adequate legal
description or by reference to a plat showing the boundaries;
4)
A statement that the ordinance restricting groundwater use has been used
by the Agency in reviewing a request for a groundwater remediation
objective;
5)
A statement as to the nature of the release and response action with the site
name, address, and Agency site number or Illinois inventory identification
number; and
6)
A statement as to where more information may be obtained regarding the
ordinance.
d)
Unless the Agency and the unit of local government have entered into a MOU
under subsection (i) of this Section, the current owner or successors in interest of
a site who have received approval of use of an ordinance as an institutional
control under this Section shall:
1)
Monitor activities of the unit of local government relative to variance
requests or changes in the ordinance relative to the use of potable
groundwater at properties identified in subsection (b)(4) (b)(3) of this
Section; and
2)
Notify the Agency of any approved variance requests or ordinance
changes within 30 days after the date such action has been approved.
e)
The information required in subsections (b)(1) through (b)(6) (b)(5) of this
Section and the Agency letter approving the groundwater remediation objective
shall be submitted to the unit of local government. Proof that the information has
been filed with the unit of local government shall be provided to the Agency.
f)
Any ordinance or MOU used as an institutional control pursuant to this Section
shall be recorded in the Office of the Recorder or Registrar of Titles of the county
in which the site is located together with the instrument memorializing the
Agency's no further remediation determination pursuant to the specific program
within 45 days after receipt of the Agency's no further remediation determination.
g)
An institutional control approved under this Section shall not become effective
until officially recorded in accordance with subsection (f) of this Section. The
person receiving the approval shall obtain and submit to the Agency within 30
33
days after recording a copy of the institutional control demonstrating that it has
been recorded.
h)
The following shall be grounds for voidance of the ordinance as an institutional
control and the instrument memorializing the Agency's no further remediation
determination:
1)
Modification of the ordinance by the unit of local government to allow
potable use of groundwater;
2)
Approval of a site-specific request, such as a variance, to allow potable
use of groundwater at a site identified in subsection (b)(4) (b)(3) of this
Section; or
3)
Violation of the terms of an institutional control recorded under Section
742.1005 or Section 742.1010.
i)
The Agency and a unit of local government may enter into a MOU under this
Section if the unit of local government has adopted an ordinance satisfying
subsection (a) of this Section and if the requirements of this subsection are met.
The MOU shall include the following:
1)
Identification of the authority of the unit of local government to enter the
MOU;
2)
Identification of the legal boundaries, or equivalent, under which the
ordinance is applicable;
3)
A certified copy of the ordinance;
4)
A commitment by the unit of local government to notify the Agency of
any variance requests or proposed ordinance changes at least 30 days prior
to the date the local government is scheduled to take action on the request
or proposed change;
5)
A commitment by the unit of local government to maintain a registry of all
sites within the unit of local government that have received no further
remediation determinations pursuant to specific programs; and
6)
If the ordinance does not expressly prohibit the installation of potable
water supply wells (and the use of such wells) by units of local
government, a commitment by the unit of local government:
A)
To review the registry of sites established under subsection (i)(5)
of this Section prior to siting potable water supply wells within the
area covered by the ordinance;
34
B)
To determine whether the potential source of potable water may be
or has been affected by contamination left in place at those sites;
and
C)
To take whatever steps are necessary to ensure that the potential
source of potable water is protected from the contamination or
treated before it is used as a potable water supply.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ____________________)
Section 742.1020
Highway Authority Agreements
a)
An agreement with a highway authority may be used as an institutional control
where the requirements of this Section are met and the Agency has determined
that no further remediation is required as to the property(ies) to which the
agreement is to apply.
b)
As part of the agreement the highway authority shall agree to:
1)
Prohibit the use of groundwater under the highway right of way that is
contaminated above residential Tier 1 remediation objectives from the
release as a potable supply of water; and
2)
Limit access to soil contamination under the highway right of way that is
contaminated above residential Tier 1 remediation objectives from the
release. Access to soil contamination may be allowed if, during and after
any access, public health and the environment are protected.
c)
The agreement shall provide the following:
1)
Fully executed signature blocks by the highway authority and the owner of
the property (or, in the case of a petroleum leaking underground storage
tank, the owner or operator of the tank) from which the release occurred;
2)
A scaled map delineating the area and extent of soil and groundwater
contamination above the applicable Tier 1 remediation objectives or a
statement that either soil or groundwater is not contaminated above the
applicable Tier 1 residential remediation objectives;
3)
Information showing the concentration of contaminants of concern within
the zone in which the applicable Tier 1 remediation objectives are
exceeded;
4)
A stipulation of the information required by subsections (b) (c)(2) and (3)
of this Section in the agreement if it is not practical to obtain the
information by sampling the highway right-of-way; and
35
5)
Information identifying the current fee owner of the highway right-of-way
and highway authority having jurisdiction.
d)
Highway Authority Agreements must be referenced in the instrument that is to be
recorded on the chain of title for the remediation property.
ed)
Violation of the terms of an Agreement approved by the Agency as an
institutional control under this Section shall be grounds for voidance of the
Agreement as an institutional control and the instrument memorializing the
Agency's no further remediation determination.
f)
Failure to provide all of the information required in subsections (b) and (c) of this
Section will be grounds for denial of the hHighway aAuthority aAgreement as an
institutional control.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ____________________)
SUBPART K: ENGINEERED BARRIERS
Section 742.1105
Engineered Barrier Requirements
a)
Natural attenuation, access controls, and point of use treatment shall not be
considered engineered barriers. Engineered barriers may not be used to prevent
direct human exposure to groundwater without the use of institutional controls.
b)
For purposes of determining remediation objectives under Tier 1, engineered
barriers are not recognized.
c)
The following engineered barriers are recognized for purposes of calculating
remediation objectives that exceed residential remediation objectives:
1)
For the soil component of the groundwater ingestion exposure route, the
following engineered barriers are recognized if they prevent completion of
the exposure pathway:
A)
Caps, covering the contaminated media, or walls constructed of
compacted clay, asphalt, concrete or other material approved by
the Agency; and
B)
Permanent structures such as buildings and highways.
2)
For the soil ingestion exposure route, the following engineered barriers are
recognized if they prevent completion of the exposure pathway:
A)
Caps, covering the contaminated media, or walls constructed of
compacted clay, asphalt, concrete, or other material approved by
the Agency;
36
B)
Permanent structures such as buildings and highways; and
C)
Clean soil, covering the contaminated media, that is a minimum of
three feet in depth.
C)
Soil, sand, gravel, or other geologic materials that:
i)
Cover the contaminated media;
ii)
Meet the soil remediation objectives under Subpart E for
residential property for contaminants of concern; and
iii)
Are a minimum of three feet in depth.
3)
For the inhalation exposure route, the following engineered barriers are
recognized if they prevent completion of the exposure pathway:
A)
Caps, covering the contaminated media, or walls constructed of
compacted clay, asphalt, concrete, or other material approved by
the Agency;
B)
Permanent structures such as buildings and highways; and
C)
Clean soil covering the contaminated media, that is a minimum of
ten feet in depth and not within ten feet of any manmade pathway.
C)
Soil, sand, gravel, or other geologic materials that:
i)
Cover the contaminated media;
ii)
Meet the soil remediation objectives under Subpart E for
residential property for contaminants of concern; and
iii)
Are a minimum of ten feet in depth and not within ten feet
of any manmade pathway.
4)
For the ingestion of groundwater exposure route, the following engineered
barriers are recognized if they prevent completion of the exposure
pathway:
A)
Slurry walls; and
B)
Hydraulic control of groundwater.
d)
Unless otherwise prohibited under Section 742.1100, any other type of engineered
barrier may be proposed if it will be as effective as the options listed in subsection
(c) of this Section.
(Source: Amended in R00-19(B) at 24 25 Ill. Reg. _______, effective ____________________)
