Section 302.100  Definitions

 

Unless otherwise specified, the definitions of the Environmental Protection Act (Act) [415 ILCS 5] and 35 Ill. Adm. Code 301 apply to this Part.  As used in this Part, each of the following definitions has the specified meaning.

 

"Acute Toxicity" means the capacity of any substance or combination of substances to cause mortality or other adverse effects in an organism resulting from a single or short-term exposure to the substance.

 

"Adverse Effect" means any gross or overt effect on an organism, including reversible histopathological damage, severe convulsions, irreversible functional impairment, and lethality, as well as any non-overt effect on an organism resulting in functional impairment or pathological lesions that may affect the performance of the whole organism, or that reduces an organism's ability to respond to an additional challenge.

 

"Chronic Toxicity" means the capacity of any substance or combination of substances to cause injurious or debilitating effects in an organism that result from exposure for a time period representing a substantial portion of the natural life cycle of that organism, including the growth phase, the reproductive phases, or such critical portions of the natural life cycle of that organism.

 

"Criterion" means the numerical concentration of one or more toxic substances derived in compliance with the procedures in Subpart F that, if not exceeded, would assure compliance with the narrative toxicity standard of Section 302.210.

 

"Early Life Stages" of fish means the pre-hatch embryonic period, the post-hatch free embryo or yolk-sac fry, and the larval period, during which the organism feeds.  Juvenile fish, which are anatomically similar to adults, are not considered to be an early life stage.

 

"Hardness" means a water quality parameter or characteristic consisting of the sum of calcium and magnesium concentrations expressed in terms of equivalent milligrams per liter as calcium carbonate.  Hardness is measured in compliance with methods specified in 40 CFR 136, incorporated by reference in 35 Ill. Adm. Code 301.106.

 

"Mixing Zone" means a portion of the waters of the State identified as a region within which mixing is allowed under Section 302.102(d).

 

"Thermocline" means the plane of maximum rate of decrease of temperature with respect to depth in a thermally stratified body of water.

 

"Total Residual Chlorine" or "TRC" means those substances that include combined and uncombined forms of both chlorine and bromine and that are expressed, by convention, as an equivalent concentration of molecular chlorine.  TRC is measured in compliance with methods specified in 40 CFR 136, incorporated by reference in 35 Ill. Adm. Code 301.106.

 

"Toxic Substance" means a chemical substance that causes adverse effects in humans, or in aquatic or terrestrial animal or plant life.  Toxic substances include those substances listed in 40 CFR 302.4, incorporated by reference in 35 Ill. Adm. Code 301.106, or any "chemical substance" as defined by the Illinois Chemical Safety Act [430 ILCS 45]

 

"ZID" or "Zone of Initial Dilution" means a portion of a mixing zone, identified pursuant to Section 302.102(e), within which acute toxicity standards need not be met.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.101  Scope and Applicability

 

a)         This Part contains water quality standards that apply throughout the State as designated in 35 Ill. Adm. Code 303. Site-specific water quality standards are found with the water use designations in 35 Ill. Adm. Code 303.

 

b)         Subpart B contains general use water quality standards that must be met in waters of the State for which there is no specific use designation (35 Ill. Adm. Code 303.201).

 

c)         Subpart C contains the public and food processing water supply standards. These are cumulative with Subpart B and must be met by all designated waters at the point at which water is drawn for treatment and distribution as a potable supply or for food processing (35 Ill. Adm. Code 303.202).

 

d)         Subpart D contains the Chicago Area Waterway System and the Lower Des Plaines River water quality standards.  These standards must be met only by certain waters designated in 35 Ill. Adm. Code 303.204, 303.220, 303.225, 303.227, 303.230, 303.235, 303.240, and 303.449.  Subpart D also contains water quality standards applicable to indigenous aquatic life waters found only in the South Fork of the South Branch of the Chicago River (Bubbly Creek).

 

e)         Subpart E contains the Lake Michigan Basin water quality standards.  These must be met in the waters of the Lake Michigan Basin as designated in 35 Ill. Adm. Code 303.443.

 

f)         Subpart F contains the procedures for determining each of the criteria designated in Sections 302.210 and 302.410.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.102  Allowed Mixing, Mixing Zones, and ZIDs

 

a)         Whenever a water quality standard is more restrictive than its corresponding effluent standard, or where there is no corresponding effluent standard specified at 35 Ill. Adm. Code 304, an opportunity will be allowed for compliance with 35 Ill. Adm. Code 304.105 by the mixture of an effluent with its receiving waters, provided the discharger has made every effort to comply with the requirements of 35 Ill. Adm. Code 304.102.

 

b)         The portion, volume, and area of any receiving waters within which mixing is allowed pursuant to subsection (a) must be limited by the following:

 

1)         Mixing must be confined in an area or volume of the receiving water no larger than the area or volume that would result after incorporation of outfall design measures to attain optimal mixing efficiency of effluent and receiving waters.  These measures may include the use of diffusers and engineered location and configuration of discharge points.

 

2)         Mixing is not allowed in waters that include a tributary stream entrance if the mixing occludes the tributary mouth or otherwise restricts the movement of aquatic life into or out of the tributary.

 

3)         Mixing is not allowed in water adjacent to bathing beaches, bank fishing areas, boat ramps or dockages or any other public access area.

 

4)         Mixing is not allowed in waters containing mussel beds; endangered species habitat; fish spawning areas; areas of important aquatic life habitat; or any other natural features vital to the well-being of aquatic life in a manner that maintaining aquatic life in the body of water as a whole would be adversely affected.

 

5)         Mixing is not allowed in waters that contain intake structures of public or food processing water supplies, points of withdrawal of water for irrigation, or watering areas accessed by wild or domestic animals.

 

6)         Mixing must allow for a zone of passage for aquatic life in which water quality standards are met.  However, a zone of passage is not required in receiving streams that have zero flow for at least seven consecutive days recurring on average in nine years out of 10.

 

7)         The area and volume in which mixing occurs, alone or in combination with other areas and volumes of mixing, must not intersect any area of any body of water in such a manner that the maintenance of aquatic life in the body of water as a whole would be adversely affected.

 

8)         The area and volume in which mixing occurs, alone or in combination with other areas and volumes of mixing must not contain more than 25% of the cross-sectional area or volume of flow of a stream except for those streams for which the dilution ratio is less than 3:1.  In streams where the dilution ratio is less than 3:1, the volume in which mixing occurs, alone or in combination with other volumes of mixing, must not contain more than 50% of the volume flow unless an applicant for an NPDES permit demonstrates, pursuant to subsection (d), that an adequate zone of passage is provided for pursuant to subsection (b)(6).

 

9)         No mixing is allowed when the water quality standard for the constituent in question is already violated in the receiving water.

 

10)        No body of water may be used totally for mixing of single outfall or combination of outfalls, except as provided in subsection (b)(6).

 

11)        Single sources of effluents that have more than one outfall must be limited to a total area and volume of mixing no larger than that allowable if a single outfall were used.

 

12)        The area and volume in which mixing occurs must be as small as is practicable under the limitations prescribed in this subsection (b), and in no circumstances may the mixing encompass a surface area larger than 26 acres.

 

c)         All water quality standards of this Part must be met at every point outside of the area and volume of the receiving water within which mixing is allowed.  The acute toxicity standards of this Part must be met within the area and volume within which mixing is allowed, except as provided in subsection (e).

 

d)         Under the procedures of Section 39 of the Act and 35 Ill. Adm. Code 309, a person may apply to the Agency to include as a condition in an NPDES permit a formal definition of the area and volume of the waters of the State within which mixing is allowed for the NPDES discharge in question.  The defined area and volume of allowed mixing will constitute a "mixing zone" for 35 Ill. Adm. Code Subtitle C.  Upon proof by the applicant that a proposed mixing zone conforms with the requirements of Section 39 of the Act, this Section, and any additional limitations as may be imposed by the Clean Water Act (CWA) (33 U.S.C. 1251 et seq.), the Act, or Board regulations, the Agency must, under Section 39(b) of the Act, include within the NPDES permit a condition defining the mixing zone.

 

e)         Under Section 39 of the Act and 35 Ill. Adm. Code 309, a person may apply to the Agency to include as a condition in an NPDES permit a ZID as a component portion of a mixing zone.  The ZID must be limited to waters within which effluent dispersion is immediate and rapid.  For this subsection, "immediate" dispersion means an effluent's merging with receiving waters without delay in time after its discharge and within close proximity to the end of the discharge pipe so as to minimize the length of exposure time of aquatic life to undiluted effluent, and "rapid" dispersion means an effluent's merging with receiving waters so as to minimize the length of exposure time of aquatic life to undiluted effluent.  Upon proof by the applicant that a proposed ZID conforms with the requirements of Section 39 of the Act and this Section, the Agency must, under Section 39(b) of the Act, include within the NPDES permit a condition defining the ZID.

 

f)         Under Section 39 of the Act and 35 Ill. Adm. Code 309.103, an applicant for an NPDES permit must submit data to allow the Agency to determine that the nature of any mixing zone or mixing zone in combination with a ZID conforms with the requirements of Section 39 of the Act and this Section.  A permittee may appeal Agency determinations concerning a mixing zone or ZID under the procedures of Section 40 of the Act and 35 Ill. Adm. Code 309.181.

 

g)         When a mixing zone is defined in an NPDES permit, the waters within that mixing zone, for the duration of that NPDES permit, constitutes the sole waters within which mixing is allowed for the permitted discharge.  It will not be a defense in any action brought pursuant to 35 Ill. Adm. Code 304.105 that the area and volume of waters within which mixing may be allowed pursuant to subsection (b) is less restrictive than the area or volume of waters encompassed in the mixing zone.

 

h)         When a mixing zone is explicitly denied in an NPDES permit, no waters may be used for mixing by the discharge to which the NPDES permit applies, all other provisions of this Section notwithstanding.

 

i)          Where an NPDES permit is silent on the matter of a mixing zone, or when no NPDES permit is in effect, the burden of proof will be on the discharger to demonstrate compliance with this Section in any action brought pursuant to 35 Ill. Adm. Code 304.105.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.103  Stream Flows

 

Except as otherwise provided in this Chapter, the water quality standards in this Part apply at all times except during periods when flows are less than the average minimum seven-day low flow that occurs once in ten years.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.104  Main River Temperatures

 

Main river temperatures are temperatures of those portions of a river essentially similar to and following the same thermal regime as the temperatures of the main flow of the river.

 

Section 302.105  Antidegradation

 

This Section protects existing uses of all waters of the State of Illinois, maintains the quality of waters with quality that is better than water quality standards, and prevents unnecessary deterioration of waters of the State.

 

a)         Existing Uses

Uses actually attained in a surface water body or water body segment on or after November 28, 1975, whether or not they are included in the water quality standards, must be maintained and protected.  Examples of degradation of existing uses of the waters of the State include:

 

1)         an action that would result in the deterioration of the existing aquatic community, such as a shift from a community of predominantly pollutant-sensitive species to pollutant-tolerant species or a loss of species diversity;

 

2)         an action that would result in a loss of a resident or indigenous species whose presence is necessary to sustain commercial or recreational activities; or

 

3)         an action that would preclude continued use of a surface water body or water body segment for a public water supply or recreational or commercial fishing, swimming, paddling, or boating.

 

b)         Outstanding Resource Waters

 

1)         Waters that are designated as Outstanding Resource Waters (ORWs) pursuant to 35 Ill. Adm. Code 303.205 and listed in 35 Ill. Adm. Code 303.206 must not be lowered in quality except as provided below:

 

A)        Activities that result in short-term, temporary (i.e., weeks or months) lowering of water quality in an ORW; or

 

B)        Existing site stormwater discharges that comply with applicable federal and State stormwater management regulations and do not result in a violation of any water quality standards.

 

2)         Any activity in subsection (b)(1)(A) or (b)(1)(B) that requires a National Pollutant Discharge Elimination System (NPDES) permit or a Clean Water Act (CWA) Section 401 certification must also comply with subsection (c)(2).

 

3)         Any activity listed in subsection (b)(1) or any other proposed increase in pollutant loading to an ORW must also meet the following requirements:

 

A)        All existing uses of the water will be fully protected; and

 

B)        Except for activities falling under one of the exceptions provided in subsection (b)(1)(A) or (B) above:

 

i)          The proposed increase in pollutant loading is necessary for an activity that will improve water quality in the ORW; and

 

ii)         The improvement could not be practicably achieved without the proposed increase in pollutant loading.

 

4)         Any proposed increase in pollutant loading requiring an NPDES permit or a CWA 401 certification for an ORW must be assessed pursuant to subsection (f) to determine compliance with this Section.

 

c)         High-Quality Waters

 

1)         Except as otherwise provided in subsection (d), waters of the State whose existing quality is better than any of the established standards of this Part must be maintained in their present high quality unless the lowering of water quality is necessary to accommodate important economic or social development.

 

2)         The Agency must assess any proposed increase in pollutant loading that necessitates a new, renewed, or modified NPDES permit or any activity requiring a CWA Section 401 certification to determine compliance with this Section.  The assessment to determine compliance with this Section must be made on a case-by-case basis.  In making this assessment, the Agency must:

 

A)        Consider the fate and effect of any parameters proposed for an increased pollutant loading.

 

B)        Assure the following:

 

i)          The applicable numeric or narrative water quality standard will not be exceeded as a result of the proposed activity;

 

ii)         All existing uses will be fully protected;

 

iii)        All technically and economically reasonable measures to avoid or minimize the extent of the proposed increase in pollutant loading have been incorporated into the proposed activity; and

 

iv)        The activity that results in an increased pollutant loading will benefit the community at large.

 

C)        Use the following information sources, when available:

 

i)          Information, data, or reports available to the Agency from its own sources;

 

ii)         Information, data, or reports supplied by the applicant;

 

iii)        Agency experience with factually similar permitting scenarios; and

 

iv)        Any other valid information available to the Agency.

 

d)         Activities Not Subject to a Further Antidegradation Assessment

The following activities will not be subject to a further antidegradation assessment under subsection (c).

 

1)         Short-term, temporary (i.e., weeks or months) lowering of water quality;

 

2)         Bypasses that are not prohibited at 40 CFR 122.41(m), incorporated by reference at 35 Ill. Adm. Code 301.106;

 

3)         Response actions under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended, corrective actions under the Resource Conservation and Recovery Act (RCRA), as amended, or similar federal or State authority, taken to alleviate a release into the environment of hazardous substances, pollutants, or contaminants that may pose a danger to public health or welfare;

 

4)         Thermal discharges that have been approved through a CWA Section 316(a) demonstration;

 

5)         New or increased discharges of a non-contact cooling water:

 

A)        without additives, except as provided in subsection (d)(5)(B), returned to the same body of water from which it was taken, as defined by 35 Ill. Adm. Code 352.104, provided that the discharge complies with applicable Illinois thermal standards; or

 

B)        containing chlorine when the non-contact cooling water is treated to remove residual chlorine, and returned to the same body of water from which it was taken, as defined in 35 Ill. Adm. Code 352.104, provided that the discharge complies with applicable Illinois thermal and effluent standards at 35 Ill. Adm. Code 302, 303, and 304;

 

6)         Discharges permitted under a current general NPDES permit as provided by 415 ILCS 5/39(b) or a nationwide or regional CWA Section 404 permit are not subject to facility-specific antidegradation review; however, the Agency must assure that individual permits or certifications are required before all new pollutant loadings or hydrological modifications that necessitate a new, renewed, or modified NPDES permit, or CWA Section 401 certification that affects waters of particular biological significance, which may include streams identified by the Illinois Department of Natural Resources as "biologically significant"; or

 

7)         Changing or including a new permit limitation that does not result in an actual increase of a pollutant loading, such as those stemming from improved monitoring data, new analytical testing methods, new or revised technology, or water quality-based effluent limits.

 

e)         Lake Michigan Basin

Waters in the Lake Michigan basin as identified in 35 Ill. Adm. Code 303.443 are also subject to the requirements applicable to bioaccumulative chemicals of concern found at Section 302.521.

 

f)         Antidegradation Assessments

In conducting an antidegradation assessment under this Section, the Agency must comply with the following procedures.

 

1)         A permit application for any proposed increase in pollutant loading that necessitates the issuance of a new, renewed, or modified NPDES permit or a CWA Section 401 certification must include, to the extent necessary for the Agency to determine that the permit application meets the requirements of this Section, the following information:

 

A)        Identification and characterization of the water body affected by the proposed load increase or proposed activity and the existing water body's uses.  The characterization must address the physical, biological, and chemical conditions of the water body.

 

B)        Identification and quantification of the proposed load increases for the applicable parameters and of the potential impacts of the proposed activity on the affected waters.

 

C)        The purpose and anticipated benefits of the proposed activity.  These benefits may include:

 

i)          Providing a centralized wastewater collection and treatment system for a previously unsewered community;

 

ii)         Expanding to provide service for anticipated residential or industrial growth consistent with a community's long-range urban planning;

 

iii)        Adding a new product line or production increase or modification at an industrial facility; or

 

iv)        Increasing or retaining current employment levels at a facility.

 

D)        Assessments of alternatives to proposed increases in pollutant loading or activities subject to Agency certification under Section 401 of the CWA that result in less of a load increase, no load increase, or minimal environmental degradation.  These alternatives may include:

 

i)          Additional treatment levels, including no discharge alternatives;

 

ii)         Discharge of waste to alternate locations, including publicly-owned treatment works and streams with greater assimilative capacity; or

 

iii)        Manufacturing practices that incorporate pollution prevention techniques.

 

E)        Any additional information the Agency may request.

 

F)         Proof that a copy of the application has been provided to the Illinois Department of Natural Resources.

 

2)         The Agency must complete an antidegradation assessment in compliance with the provisions of this Section on a case-by-case basis.

 

A)        The Agency must consider the criteria stated in Section 302.105(c)(2).

 

B)        The Agency must consider the information provided by the applicant under subsection (f)(1).

 

C)        After its assessment, the Agency must produce a written analysis addressing the requirements of this Section and provide a decision yielding one of the following results:

 

i)          If the proposed activity meets the requirements of this Section, then the Agency must proceed with public notice of the NPDES permit or CWA Section 401 certification and include the written analysis as a part of the fact sheet accompanying the public notice;

 

ii)         If the proposed activity does not meet the requirements of this Section, then the Agency must provide a written analysis to the applicant and must be available to discuss the deficiencies that led to the disapproval.  The Agency may suggest methods to remedy the conflicts with the requirements of this Section;

 

iii)        If the proposed activity does not meet the requirements of this Section, but some lowering of water quality is allowable, then the Agency must contact the applicant with the results of the review.  If the reduced loading increase is acceptable to the applicant, upon the receipt of an amended application, the Agency must proceed to public notice; or if the reduced loading increase is not acceptable to the applicant, the Agency must transmit its written review to the applicant in the context of an NPDES permit denial or a CWA Section 401 certification denial.

 

3)         The Agency must conduct public notice and public participation through the public notice procedures found in 35 Ill. Adm. Code 309.109 or CWA Section 401 certifications.  The Agency must incorporate the following information into a fact sheet accompanying the public notice:

 

A)        A description of the activity, including identification of water quality parameters for which there will be an increased pollutant loading;

 

B)        Identification of the affected surface water body or water body segment and any downstream surface water body or water body segment also expected to experience a lowering of water quality, characterization of the designated and current uses of the affected surface water body or water body segment, and identification of which uses are most sensitive to the proposed load increase;

 

C)        A summary of any review comments and recommendations provided by the Illinois Department of Natural Resources, local or regional planning commissions, zoning boards, and any other entities the Agency consults regarding the proposal;

 

D)        An overview of alternatives considered by the applicant and identification of any provisions or alternatives imposed to lessen the load increase associated with the proposed activity; and

 

E)        The name and telephone number of a contact person at the Agency who can provide additional information.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.201  Scope and Applicability

 

Subpart B contains general use water quality standards that must be met in waters of the State for which there is no specific designation (35 Ill. Adm. Code 303.201).

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.202  Purpose

 

The general use standards will protect the State's water for aquatic life, wildlife, agricultural use, secondary contact use, and most industrial uses and ensure the aesthetic quality of the State's aquatic environment.  Primary contact uses are protected for all general use waters whose physical configuration permits primary contact use.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.203  Offensive Conditions

 

Waters of the State must be free from sludge or bottom deposits, floating debris, visible oil, odor, plant or algal growth, and color or turbidity of other than natural origin.  The allowed mixing provisions of Section 302.102 must not be used to comply with the provisions of this Section.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.204  pH

 

pH must be within the range of 6.5 to 9.0 except due to natural causes.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.205  Phosphorus

 

Phosphorus:  After December 31, 1983, Phosphorus as P must not exceed 0.05 milligram per liter (mg/L) in any reservoir or lake with a surface area of 8.1 hectares (20 acres) or more, or in any stream at the point where it enters that reservoir or lake.  For this Section, the term "reservoir or lake" does not include low-level pools constructed in free-flowing streams or any body of water that is an integral part of an operation that includes the application of sludge on land.  Point source discharges which comply with 35 Ill. Adm. Code 304.123 must comply with this Section for purposes of 35 Ill. Adm. Code 304.105.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.206  Dissolved Oxygen

 

General use waters must maintain dissolved oxygen concentrations at or above the values contained in subsections (a), (b), and (c).

 

a)         General use waters at all locations must maintain sufficient dissolved oxygen concentrations to prevent offensive conditions as required in Section 302.203.  Quiescent and isolated sectors of general use waters including wetlands, sloughs, backwaters, and waters below the thermocline in lakes and reservoirs must be maintained at sufficient dissolved oxygen concentrations to support their natural ecological functions and resident aquatic communities.

 

b)         Except in those waters identified in Appendix D, the dissolved oxygen concentration in the main body of all streams, in the water above the thermocline of thermally stratified lakes and reservoirs, and in the entire water column of unstratified lakes and reservoirs must not be less than the following:

 

1)         During March through July,

 

A)        5.0 mg/L at any time; and

 

B)        6.0 mg/L as a daily mean averaged over 7 days.

 

2)         During August through February,

 

A)        3.5 mg/L at any time;

 

B)        4.0 mg/L as a daily minimum averaged over 7 days; and

 

C)        5.5 mg/L as a daily mean averaged over 30 days.

 

c)         The dissolved oxygen concentration in all sectors within the main body of all streams identified in Appendix D must not be less than:

 

1)         During March through July,

 

A)        5.0 mg/L at any time; and

 

B)        6.25 mg/L as a daily mean averaged over 7 days.

 

2)         During August through February,

 

A)        4.0 mg/L at any time;

 

B)        4.5 mg/L as a daily minimum averaged over 7 days; and

 

C)        6.0 mg/L as a daily mean averaged over 30 days.

 

d)         Assessing Attainment of Dissolved Oxygen Mean and Minimum Values

 

1)         Daily mean is the arithmetic mean of dissolved oxygen concentrations in 24 consecutive hours.

 

2)         Daily minimum is the minimum dissolved oxygen concentration in 24 consecutive hours.

 

3)         The measurements of dissolved oxygen used to determine attainment or lack of attainment with any of the dissolved oxygen standards in this Section must assure daily minima and daily means that represent the true daily minima and daily means.

 

4)         The dissolved oxygen concentrations used to determine a daily mean or daily minimum should not exceed the air-equilibrated concentration.

 

5)         "Daily minimum averaged over 7 days" means the arithmetic mean of daily minimum dissolved oxygen concentrations in 7 consecutive 24-hour periods.

 

6)         "Daily mean averaged over 7 days" means the arithmetic mean of daily mean dissolved oxygen concentrations in 7 consecutive 24-hour periods.

 

7)         "Daily mean averaged over 30 days" means the arithmetic mean of daily mean dissolved oxygen concentrations in 30 consecutive 24-hour periods.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.207  Radioactivity

 

a)         Gross beta concentration must not exceed 100 picocuries per liter (pCi/L).

 

b)         Strontium 90 concentration must not exceed 2 pCi/L.

 

c)         The annual average radium 226 and 228 combined concentration must not exceed 3.75 pCi/L.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.208  Numeric Standards for Chemical Constituents

 

a)         The acute standard (AS) for the chemical constituents listed in subsection (e) must not be exceeded at any time except for those waters for which a zone of initial dilution (ZID) has been approved by the Agency under Section 302.102.

 

b)         The chronic standard (CS) for the chemical constituents listed in subsection (e) must not be exceeded by the arithmetic average of at least four consecutive samples collected over any period of at least four days, except for those waters in which the Agency has approved a mixing zone or in which mixing is allowed under 35 Ill. Adm. Code 302.102.  The samples used to demonstrate attainment or lack of attainment with a CS must be collected in a manner that assures an average representative of the sampling period.  For the chemical constituents that have water quality-based standards dependent upon hardness, the chronic water quality standard will be calculated according to subsection (e) using the hardness of the water body at the time the sample was collected.  To calculate the attainment status of chronic standards, the concentration of the chemical constituent in each sample is divided by the calculated water quality standard for the sample to determine a quotient.  The water quality standard is attained if the mean of the sample quotients is less than or equal to one for the duration of the averaging period.

 

c)         The human health standard (HHS) for the chemical constituents listed in subsection (f) must not be exceeded when the streamflow is at or above the harmonic mean flow under Section 302.658, nor must an annual average, based on at least eight samples collected in a manner representative of the sampling period, exceed the HHS except for those waters in which the Agency has approved a mixing zone or in which mixing is allowed under Section 302.102.

 

d)         The standard for the chemical constituents of subsections (g) and (h) must not be exceeded at any time except for those waters in which the Agency has approved a mixing zone or in which mixing is allowed under Section 302.102.

 

e)         Numeric Water Quality Standards for the Protection of Aquatic Organisms

 

Constituent	AS (µg/L)	CS (µg/L)
Arsenic (trivalent, dissolved)	360 x 1.0* = 360	190 x 1.0* = 190
Boron (total)	40,100	7,600
Cadmium (dissolved)	*	*
	where A = -2.918 and B = 1.128	where A = -3.490 and B = 0.7852
Chromium (hexavalent, total)	16	11
Chromium (trivalent, dissolved)	where A = 3.688 and B = 0.8190	where A = 1.561 and B = 0.8190
Copper (dissolved)	where A = -1.464 and B = 0.9422	where A = -1.465 and B = 0.8545
Cyanide**	22	5.2
Fluoride (total)		, but must not exceed 4.0 mg/L
	where A = 6.7319 and B = 0.5394	where A = 6.0445 and B = 0.5394
Lead (dissolved)
	where A = -1.301 and B = 1.273	where A = -2.863 and B = 1.273
Manganese (dissolved)	0.9812*	0.9812*
	where A = 4.9187 and B = 0.7467	where A = 4.0635 and B = 0.7467
Mercury (dissolved)	2.6 x 0.85* = 2.2	1.3 x 0.85* = 1.1
Nickel (dissolved)
	where A = 0.5173 and B = 0.8460	where A = -2.286 and B = 0.8460
TRC	19	11
Zinc (dissolved)
	where A = 0.9035 and B = 0.8473	where A = -0.4456 and B = 0.8473
Benzene	4200	860
Ethylbenzene	150	14
Toluene	2000	600
Xylene(s)	920	360

 

where:
	µg/L	=	microgram per liter
	ex	=	base of natural logarithms raised to the x-power
	ln(H)	=	natural logarithm of hardness (in mg/L as CaCO3)
	*	=	conversion factor multiplier for dissolved metals
	**	=	standard to be evaluated using either of the following USEPA approved methods, incorporated by reference at 35 Ill. Adm. Code 301.106:  Method OIA-1677, DW:  Available Cyanide by Flow Injection, Ligand Exchange, and Amperometry, January 2004, Document Number EPA-821-R-04-001 or Cyanide Amenable to Chlorination, Standard Methods 4500-CN-G (40 CFR 136.3)

 

f)         Numeric Water Quality Standard for the Protection of Human Health

 

Constituent		(µg/L)
Mercury (total)		0.012
Benzene		310

 

where:
	µg/L	=	micrograms per liter

 

g)         Single-value standards apply at the following concentrations for these substances:

 

Constituent	Unit		Standard
Barium (total)	mg/L		5.0
Chloride (total)	mg/L		500
Iron (dissolved)	mg/L		1.0
Phenols	mg/L		0.1
Selenium (total)	mg/L		1.0
Silver (total)	µg/L		5.0

 

where:
	mg/L	=	milligram per liter and
	µg/L	=	microgram per liter

 

h)         Water quality standards for sulfate are as follows: 

 

1)         At any point where water is withdrawn or accessed for purposes of livestock watering, the average of sulfate concentrations must not exceed 2,000 mg/L when measured at a representative frequency over a 30-day period.

 

2)         The results of the following equations provide sulfate water quality standards in mg/L for the specified ranges of hardness (in mg/L as CaCO₃) and chloride (in mg/L) and must be met at all times:

 

A)        If the hardness concentration of receiving waters is greater than or equal to 100 mg/L but less than or equal to 500 mg/L, and if the chloride concentration of waters is greater than or equal to 25 mg/L but less than or equal to 500 mg/L, then:

 

C = [1276.7 + 5.508 (hardness) - 1.457 (chloride)] * 0.65

 

where:

 

C = sulfate concentration

 

B)        If the hardness concentration of waters is greater than or equal to 100 mg/L but less than or equal to 500 mg/L, and if the chloride concentration of waters is greater than or equal to 5 mg/L but less than 25 mg/L, then:

 

C = [-57.478 + 5.79 (hardness) + 54.163 (chloride)] * 0.65

 

where:

 

C = sulfate concentration

 

3)         The following sulfate standards must be met at all times when hardness (in mg/L as CaCO₃) and chloride (in mg/L) concentrations other than specified in subsection (h)(2) are present:

 

A)        If the hardness concentration of waters is less than 100 mg/L or chloride concentration of waters is less than 5 mg/L, the sulfate standard is 500 mg/L.

 

B)        If the hardness concentration of waters is greater than 500 mg/L and the chloride concentration of waters is 5 mg/L or greater, the sulfate standard is 2,000 mg/L. 

 

C)        If the combination of hardness and chloride concentrations of existing waters are not reflected in subsection (h)(3)(A) or (B), the sulfate standard may be determined in a site-specific rulemaking under section 303(c) of the Federal Water Pollution Control Act of 1972 (Clean Water Act), 33 U.S.C. 1313(c), and Federal Regulations at 40 CFR 131.10(j)(2).

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.209  Fecal Coliform

 

a)         During the months May through October, based on a minimum of five samples taken over not more than a 30-day period, fecal coliform must not exceed a geometric mean of 200 per 100 milliliters (ml), nor must more than 10% of the samples during any 30-day period exceed 400 per 100 ml in protected waters.  Protected waters are defined as waters that, due to natural characteristics, aesthetic value, or environmental significance, deserve protection from pathogenic organisms.  Protected waters will meet one or both of the following conditions:

 

1)         presently support or have the physical characteristics to support primary contact;

 

2)         flow through or adjacent to parks or residential areas.

 

b)         Waters unsuited to support primary contact uses because of physical, hydrologic, or geographic configuration and that are located in areas unlikely to be frequented by the public on a routine basis as determined by the Agency at 35 Ill. Adm. Code 309.Subpart A are exempt from this standard.

 

c)         The Agency must apply this rule as required by 35 Ill. Adm. Code 304.121.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.210  Other Toxic Substances

 

Waters of the State must be free from any substances or combination of substances in concentrations toxic or harmful to human health or animal, plant, or aquatic life.  Individual chemical substances or parameters for which numeric standards are specified in this Subpart are not subject to this Section.

 

a)         Any substance or combination of substances must be deemed to be toxic or harmful to aquatic life if present in concentrations that exceed the following:

 

1)         An Acute Aquatic Toxicity Criterion (AATC) validly derived and correctly applied under procedures in Sections 302.612 through 302.618 or in Section 302.621; or

 

2)         A Chronic Aquatic Toxicity Criterion (CATC) validly derived and correctly applied under procedures in Section 302.627 or 302.630.

 

b)         Any substance or combination of substances must be deemed to be toxic or harmful to wild or domestic animal life if present in concentrations that exceed any Wild and Domestic Animal Protection Criterion (WDAPC) validly derived and correctly applied under Section 302.633.

 

c)         Any substance or combination of substances must be deemed to be toxic or harmful to human health if present in concentrations that exceed criteria, validly derived and correctly applied, based on either of the following:

 

1)         Disease or functional impairment due to a physiological mechanism for which there is a threshold dose below which no damage occurs calculated under Sections 302.642 through 302.648 (Human Threshold Criterion); or

 

2)         Disease or functional impairment due to a physiological mechanism for which any dose may cause some risk of damage calculated under Sections 302.651 through 302.658 (Human Nonthreshold Criterion).

 

d)         The most stringent criterion of subsections (a), (b), and (c) applies at all points outside of any waters within which mixing is allowed under Section 302.102.  In addition, the AATC derived under subsection (a)(1) applies in all waters except that it must not apply within a ZID that is prescribed in compliance with Section 302.102.

 

e)         The procedures of Subpart F set forth minimum data requirements, appropriate test protocols, and data assessment methods for establishing criteria under subsections (a), (b), and (c). No other procedures may be used to establish these criteria unless approved by the Board in a rulemaking or adjusted standard proceeding under Title VII of the Act. The validity and applicability of the Subpart F procedures may not be challenged in any proceeding brought under Title VIII or X of the Act, although the validity and correctness of application of the numeric criteria derived under Subpart F may be challenged in proceedings under subsection (f).

 

f)         Challenges to Applying Criteria

 

1)         A permittee may challenge the validity and correctness of application of a criterion derived by the Agency under this Section only at the time the criterion is first applied in an NPDES permit under 35 Ill. Adm. Code 309.152 or in an action under Title VIII of the Act for violation of the toxicity water quality standard. Failure of a person to challenge the validity of a criterion at the time of its first application will constitute a waiver of the challenge in any subsequent proceeding involving the application of the criterion to that person.

 

2)         Consistent with subsection (f)(1), if a criterion is included as, or is used to derive, a condition of an NPDES discharge permit, a permittee may challenge the criterion in a permit appeal under Section 40 of the Act and 35 Ill. Adm. Code 309.181. 

 

3)         Consistent with subsection (f)(1), in an action where the alleged violation of the toxicity water quality standard is based on an alleged excursion of a criterion, the person bringing the action will have the burdens of going forward with proof and of persuasion regarding the general validity and correctness of application of the criterion.

 

g)         Subsections (a) through (e) do not apply to USEPA-registered pesticides approved for aquatic application and applied under the following conditions:

 

1)         Application must be made in strict compliance with label directions;

 

2)         Applicator must be properly certified under the provisions of the Federal Insecticide, Fungicide, and Rodenticide Act (7 U.S.C. 136 et seq.);

 

3)         Applications of aquatic pesticides must comply with the laws, regulations, and guidelines of all state and federal agencies authorized by law to regulate, use, or supervise pesticide applications.

 

4)         Aquatic pesticides must not be applied to waters affecting public or food processing water supplies unless a permit to apply the pesticide has been obtained from the Agency.  All permits must be issued so as not to cause a violation of the Act or any of the Board's rules. To aid applicators in determining their responsibilities under this subsection, a list of waters affecting public water supplies will be published and maintained by the Agency's Division of Public Water Supplies.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.211  Temperature

 

a)         There must not be abnormal temperature changes that may adversely affect aquatic life unless caused by natural conditions.

 

b)         The normal daily and seasonal temperature fluctuations that existed before the addition of heat due to other than natural causes must be maintained.

 

c)         The maximum temperature rise above natural temperatures must not exceed 2.8 °C (5 ºF).

 

d)         In addition, the water temperature at representative locations in the main river must not exceed the maximum limits in the following table during more than one percent of the hours in the 12-month period ending with any month.  Moreover, the water temperature at those locations must never exceed the maximum limits in the following table by more than 1.7 ºC (3 ºF).

 

	ºC	ºF			ºC	ºF
JAN	16	60		JUL.	32	90
FEB.	16	60		AUG.	32	90
MAR.	16	60		SEPT.	32	90
APR.	32	90		OCT.	32	90
MAY	32	90		NOV.	32	90
JUNE	32	90		DEC.	16	60

 

e)         The owner or operator of a source of heated effluent that discharges 150 megawatts (0.5 billion British thermal units per hour) or more must demonstrate in a hearing before the Board in the case of new sources, after the commencement of operation, that discharges from that source have not caused and cannot be reasonably expected to cause significant ecological damage to the receiving waters.  If this demonstration is not made to the satisfaction of the Board, the Board will order appropriate corrective measures to be implemented within a reasonable time as determined by the Board.

 

f)         Permits for heated effluent discharges, whether issued by the Board or the Agency, can be revised if reasonable future development creates a need for reallocation of the assimilative capacity of the receiving stream as defined in the regulation above.

 

g)         The owner or operator of a source of heated effluent must maintain records and conduct studies of the effluents from the sources and of their effects as may be required by the Agency or in any permit granted under the Act.

 

h)         Appropriate corrective measures will be required if, upon complaint filed in compliance with Board rules, it is found at any time that any heated effluent causes significant ecological damage to the receiving stream.

 

i)          All effluents to an artificial cooling lake must comply with the applicable provisions of the thermal water quality standards in this Section and 35 Ill. Adm. Code 303, except when all of the following requirements are met:

 

1)         All discharges from the artificial cooling lake to other waters of the State comply with the applicable provisions of subsections (a) through (d).

 

2)         The heated effluent discharged to the artificial cooling lake complies with all other applicable provisions of this Chapter, except subsections (a) through (d).

 

3)         At an adjudicative hearing, the discharger must satisfactorily demonstrate to the Board that the artificial cooling lake receiving the heated effluent will be environmentally acceptable, and within the intent of the Act, including:

 

A)        providing conditions capable of supporting shellfish, fish and wildlife, and recreational uses consistent with good management practices, and

 

B)        controlling the thermal component of the discharger's effluent by a technologically feasible and economically reasonable method.

 

4)         The required demonstration in subsection (i)(3) may take the form of an acceptable final environmental impact statement or pertinent provisions of environmental assessments used in the preparation of the final environmental impact statement, or may take the form of a demonstration under Section 316(a) of the Clean Water Act (CWA) (33 U.S.C. 1251 et seq.) that addresses the requirements of subsection (i)(3).

 

5)         If the Board finds the demonstration to be adequate as provided in subsection (i)(3), the Board will promulgate specific thermal standards to be applied to the discharge to that artificial cooling lake.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.212  Total Ammonia Nitrogen

 

a)         Total ammonia nitrogen (as N) must in no case exceed 15 mg/L.

 

b)         The total ammonia nitrogen (as N) acute, chronic, and sub-chronic standards are determined by the equations given in subsections (b)(1) and (b)(2).  Attainment of each standard must be determined by subsections (c) and (d) in mg/L.

 

1)         The acute standard (AS) is calculated using the following equation:

 

AS	=	0.411	+	58.4
		1 + 107.204-pH		1 + 10pH-7.204

 

2)         The chronic standard (CS) is calculated using the following equations:

 

A)        During the Early Life Stage Present period, as defined in subsection (e):

 

i)          When the water temperature is less than or equal to 14.51 °C:

 

CS	=	{	0.0577	+	2.487	}	(2.85)
			1 + 107.688-pH		1 + 10pH-7.688

 

ii)         When the water temperature is above 14.51 °C:

 

CS	=	{	0.0577	+	2.487	}	(1.45*100.028*(25-T))
			1 + 107.688-pH		1 + 10pH-7.688

 

            Where T = Water Temperature, degrees Celsius

 

B)        During the Early Life Stage Absent period, as defined in subsection (e):

 

i)          When the water temperature is less than or equal to 7 °C:

 

CS	=	{	0.0577	+	2.487	}	(1.45*100.504)
			1 + 107.688-pH		1 + 10pH-7.688

 

ii)         When the water temperature is greater than 7 °C:

 

CS	=	{	0.0577	+	2.487	}	(1.45*100.028*(25-T))
			1 + 107.688-pH		1 + 10pH-7.688

 

Where T = Water Temperature, degrees Celsius

 

3)         The sub-chronic standard is equal to 2.5 times the chronic standard.

 

c)         Attainment of the Total Ammonia Nitrogen Water Quality Standards

 

1)         The acute standard of total ammonia nitrogen (in mg/L) must not be exceeded at any time except in those waters for which the Agency has approved a ZID under Section 302.102.

 

2)         The 30-day average concentration of total ammonia nitrogen (in mg/L must not exceed the chronic standard (CS) except in those waters in which mixing is allowed under Section 302.102.  Attainment of the chronic standard (CS) is evaluated under subsection (d) by averaging at least four samples collected at weekly intervals or at other sampling intervals that statistically represent a 30-day sampling period.  The samples must be collected in a manner that assures a representative sampling period.

 

3)         The 4-day average concentration of total ammonia nitrogen (in mg/L) must not exceed the sub-chronic standard except in those waters in which mixing is allowed under Section 302.102.  Attainment of the sub-chronic standard is evaluated under subsection (d) by averaging daily sample results collected over four consecutive days within the 30-day averaging period. The samples must be collected in a manner that assures a representative sampling period.

 

d)         The water quality standard for each water body must be calculated based on the temperature and pH of the water body measured at the time of each ammonia sample.  The concentration of total ammonia in each sample must be divided by the calculated water quality standard for the sample to determine a quotient.  The water quality standard is attained if the mean of the sample quotients is less than or equal to one for the duration of the averaging period.

 

e)         The Early Life Stage Present period occurs from March through October.  In addition, during any other period when early life stages are present, and where the water quality standard does not provide adequate protection for these organisms, the water body must meet the Early Life Stage Present water quality standard.  All other periods are subject to the Early Life Stage Absent period.

 

BOARD NOTE:  Acute and chronic standard concentrations for total ammonia nitrogen (in mg/L) for different combinations of pH and temperature are shown in Appendix C.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.213  Effluent Modified Waters (Ammonia) (Repealed)

 

(Source:  Repealed at 26 Ill. Reg. 16931, effective November 08, 2002)

 

Section 302.301  Scope and Applicability

 

Subpart C contains the public and food processing water supply standards. These are cumulative with the general use standards of Subpart B and must be met in all waters designated in Part 303 at any point at which water is withdrawn for treatment and distribution as a potable supply or for food processing.  Waters of the State are generally designated for public and food processing use (35 Ill. Adm. Code 303.202).

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.302  Algicide Permits

 

The water quality standards of Subparts B and C may be exceeded if the occurrence results from applying an algicide under an algicide permit issued by the Agency under 35 Ill. Adm. Code 602.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.303  Finished Water Standards

 

Water must be of such quality that, with treatment consisting of coagulation, sedimentation, filtration, storage, and chlorination, or other equivalent treatment processes, the treated water meets all requirements of 35 Ill. Adm. Code 611.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.304  Chemical Constituents

 

The following levels of chemical constituents must not be exceeded:

 

	CONCENTRATION
CONSTITUENT	(mg/L)
Arsenic (total)	0.05
Barium (total)	1.0
Boron (total)	1.0
Cadmium (total)	0.010
Chloride (total)	250
Chromium	0.05
Fluoride (total)	1.4
Iron (dissolved)	0.3
Lead (total)	0.05
Manganese (total)	1.0
Nitrate-Nitrogen	10
Oil (hexane-solubles or equivalent)	0.1
Organics
Pesticides
Chlorinated Hydro-
carbon Insecticides
Aldrin	0.001
Chlordane	0.003
DDT	0.05
Dieldrin	0.001
Endrin	0.0002
Heptachlor	0.0001
Heptachlor Expoxide	0.0001
Lindane	0.004
Methoxychlor	0.1
Toxaphene	0.0005
Organophosphate
Insecticides
Parathion	0.1
Chlorophenoxy Herbicides
2,4-Dichlorophenoxy-
acetic acid (2,4-D)	0.1
2-(2,4,5-Trichloro-
phenoxy)-propionic
acid (2,4,5-TP
or Silvex)	0.01
Phenols	0.001
Selenium (total)	0.01
Sulfate	250
Total Dissolved Solids	500

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.305  Other Contaminants

 

Other contaminants that will not be adequately reduced by the treatment processes in Section 302.303 must not be present in concentrations hazardous to human health.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.306  Fecal Coliform

 

Notwithstanding the provisions of Section 302.209, at no time shall the geometric mean, based on a minimum of five samples taken within a 30-day period, of fecal coliform exceed 2000 per 100 ml.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.307  Radium 226 and 228

 

Radium 226 and 228 combined concentration must not exceed 5 picocuries per liter (pCi/L) at any time.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.401  Scope and Applicability

 

a)         Subpart D contains the standards that must be met only by the South Fork of the South Branch of the Chicago River (Bubbly Creek).  The Subpart B general use and Subpart C public and food processing water supply standards do not apply to Bubbly Creek.

 

b)         Subpart D also contains the Chicago Area Waterway System and Lower Des Plaines River water quality standards.  Except for the Chicago River, these standards must be met only by waters specifically designated in 35 Ill. Adm. Code 303.  The Subpart B general use and Subpart C public and food processing water supply standards of this Part do not apply to waters described in 35 Ill. Adm. Code 303.204 as the Chicago Area Waterway System or Lower Des Plaines River and listed in 35 Ill. Adm. Code 303.220 through 303.240, except that waters designated as Primary Contact Recreation Waters in 35 Ill. Adm. Code 303.220 must meet the numeric water quality standard for bacteria applicable to protected waters in Section 302.209.  The Chicago River must meet the general use standards, including the numeric water quality standard for fecal coliform bacteria applicable to protected waters in 35 Ill. Adm. Code 302.209.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.402  Purpose

 

The Chicago Area Waterway System and Lower Des Plaines River standards protect primary contact, incidental contact, or non-contact recreational uses (except when designated as non-recreational waters); commercial activity, including navigation and industrial water supply uses; and the highest quality aquatic life and wildlife that is attainable, limited only by the physical condition of these waters and hydrologic modifications to these waters.  The numeric and narrative standards in this Part will assure the protection of the aquatic life, wildlife, human health, and recreational uses of the Chicago Area Waterway System and Lower Des Plaines River as those uses are defined in 35 Ill. Adm. Code 301 and designated in 35 Ill. Adm. Code 303. Indigenous aquatic life standards are intended for the South Fork of the South Branch of the Chicago River (Bubbly Creek), which is capable of supporting an indigenous aquatic life limited only by the physical configuration of the body of water, characteristics and origin of the water and the presence of contaminants in amounts that do not exceed the water quality standards listed in this Subpart D.  However, the Chicago River is required to meet the general use standard, including the water quality standard for fecal coliform bacteria applicable to protected waters in Section 302.209.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.403  Unnatural Sludge

 

Waters subject to this subpart must be free from unnatural sludge or bottom deposits, floating debris, visible oil, odor, unnatural plant or algal growth, or unnatural color or turbidity.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.404  pH

 

pH must be within the range of 6.5 to 9.0 except due to natural causes, except for the South Fork of the South Branch of the Chicago River (Bubbly Creek), for which pH must be within the range of 6.0 to 9.0 except due to natural causes.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.405  Dissolved Oxygen

 

Dissolved oxygen concentrations must not be less than the applicable values in subsections (a), (b), (c), and (d).

 

a)         For the South Fork of the South Branch of the Chicago River (Bubbly Creek), dissolved oxygen concentrations must not be less than 4.0 mg/L at any time.

 

b)         For the Upper Dresden Island Pool Aquatic Life Use waters listed in 35 Ill. Adm. Code 303.230:

 

1)         for March through July:

 

A)        6.0 mg/L as a daily mean averaged over 7 days; and

 

B)        5.0 mg/L at any time; and

 

2)         for August through February:

 

A)        5.5 mg/L as a daily mean averaged over 30 days;

 

B)        4.0 mg/L as a daily minimum averaged over 7 days; and

 

C)        3.5 mg/L at any time.

 

c)         For the Chicago Area Waterway System Aquatic Life Use A waters listed in 35 Ill. Adm. Code 303.235:

 

1)         for March through July, 5.0 mg/L at any time; and

 

2)         for August through February:

 

A)        4.0 mg/L as a daily minimum averaged over 7 days; and

 

B)        3.5 mg/L at any time.

 

d)         For the Chicago Area Waterway System and Brandon Pool Aquatic Life Use B waters listed in 35 Ill. Adm. Code 303.240:

 

1)         4.0 mg/L as a daily minimum averaged over 7 days; and

 

2)         3.5 mg/L at any time.

 

e)         Assessing Attainment of Dissolved Oxygen Mean and Minimum Values

 

1)         Daily mean is the arithmetic mean of dissolved oxygen concentrations in 24 consecutive hours.

 

2)         Daily minimum is the minimum dissolved oxygen concentration in 24 consecutive hours.

 

3)         The measurements of dissolved oxygen used to determine attainment or lack of attainment with any of the dissolved oxygen standards in this Section must assure daily minima and daily means that represent the true daily minima and daily means. 

 

4)         The dissolved oxygen concentrations used to determine a daily mean or daily minimum should not exceed the air-equilibrated concentration.

 

5)         "Daily minimum averaged over 7 days" means the arithmetic mean of daily minimum dissolved oxygen concentrations in 7 consecutive 24-hour periods.

 

6)         "Daily mean averaged over 7 days" means the arithmetic mean of daily mean dissolved oxygen concentrations in 7 consecutive 24-hour periods.

 

7)         "Daily mean averaged over 30 days" means the arithmetic mean of daily mean dissolved oxygen concentrations in 30 consecutive 24-hour periods.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.406  Fecal Coliform (Repealed)

 

(Source:  Repealed at 6 Ill. Reg. 13750, effective October 26, 1982)

 

Section 302.407  Chemical Constituents

 

a)         The acute standard (AS) for the chemical constituents listed in subsection (e) must not be exceeded at any time except as provided in subsection (d).

 

b)         The chronic standard (CS) for the chemical constituents listed in subsection (e) must not be exceeded by the arithmetic average of at least four consecutive samples collected over any period of four days, except as provided in subsection (d).  The samples used to demonstrate attainment or lack of attainment with a CS must be collected in a manner that assures an average representative of the sampling period.  For the chemical constituents that have water quality-based standards dependent upon hardness, the chronic water quality standard will be calculated according to subsection (e) using the hardness of the water body at the time the sample was collected. To calculate the attainment status of chronic standards, the concentration of the chemical constituent in each sample is divided by the calculated water quality standard for the sample to determine a quotient.  The water quality standard is attained if the mean of the sample quotients is less than or equal to one for the duration of the averaging period.

 

c)         The human health standard (HHS) for the chemical constituents listed in subsection (f) must not be exceeded, on a 12-month rolling average based on at least eight samples, collected in a manner representative of the sampling period, except as provided in subsection (d).

 

d)         In waters where mixing is allowed under Section 302.102, the following apply:

 

1)         The AS must not be exceeded in any waters except for those waters for which a zone of initial dilution (ZID) applies under Section 302.102.

 

2)         The CS must not be exceeded outside of waters in which mixing is allowed under Section 302.102.

 

3)         The HHS must not be exceeded outside of waters in which mixing is allowed under Section 302.102.

 

e)         Numeric Water Quality Standards for the Protection of Aquatic Organisms

 

Constituent	AS (µg/L)	CS (µg/L)
Arsenic (trivalent, dissolved)	340 X 1.0*=340	150 X 1.0*=150
Benzene	4200	860
Cadmium (dissolved)	eA+B ln(H) X {1.138672-[(ln(H))(0.041838)]}*, where A=-2.918 and B=1.128	eA+B ln(H) X {1.101672-[(ln(H))(0.041838)]}*, where A= -3.490 and B=0.7852
Chromium (hexavalent, total)	16	11
Chromium (trivalent, dissolved)	eA+B ln(H) X 0.316*, where A=3.7256 and B=0.8190	eA+B ln(H) X 0.860*, where A=0.6848 and B=0.8190
Copper (dissolved)	eA+B ln(H) X 0.960*, where A=-1.645 and B=0.9422	eA+B ln(H) X 0.960*, where A=-1.646 and B=0.8545
Cyanide**	22	10
Ethylbenzene	150	14
Fluoride (total)	eA+B ln(H), where A=6.7319 and B=0.5394	eA+B ln(H), but must not exceed 4.0 mg/L, where A=6.0445 and B=0.5394
Lead (dissolved)	eA+B ln(H) X {1.46203-[(ln(H))(0.145712)]}*, where A=-1.301 and B=1.273	eA+B ln(H) X {1.46203-[(ln(H))(0.145712)]}*, where A=-2.863 and B=1.273
Manganese (dissolved)	eA+B ln(H) X 0.9812*, where A=4.9187 and B=0.7467	eA+B ln(H) X 0.9812*, where A=4.0635 and B=0.7467
Mercury (dissolved)	1.4 X 0.85*=1.2	0.77 X 0.85*=0.65
Nickel (dissolved)	eA+B ln(H) X 0.998*, where A=0.5173 and B=0.8460	eA+B ln(H) X 0.997*, where A=-2.286 and B=0.8460
Toluene	2000	600
TRC	19	11
Xylene(s)	920	360
Zinc (dissolved)	eA+B ln(H) X 0.978*, where A=0.9035 and B=0.8473	eA+B ln(H) X 0.986*, where A=-0.4456 and B=0.8473

 

where: 

 

µg/L	=	microgram per liter
H	=	Hardness concentration of receiving water in mg/L as CaCO3
ex	=	base of natural logarithms raised to the x-power
ln(H)	=	natural logarithm of hardness in mg/L as CaCO3
*	=	conversion factor multiplier for dissolved metals
**	=	standard to be evaluated using either of the following USEPA approved methods, incorporated by reference at 35 Ill. Adm. Code 301.106:  Method OIA-1677, DW: Available Cyanide by Flow Injection, Ligand Exchange, and Amperometry, January 2004, Document Number EPA-821-R-04-001; or Cyanide Amenable to Chlorination, Standard Methods 4500-CN-G (40 CFR 136.3)

 

f)         Numeric Water Quality Standard for the Protection of Human Health

 

Constituent	HHS (µg/L)
Benzene	310
Mercury (total)	0.012
Phenols	860,000

 

where:

 

µg/L

=

microgram per liter

 

g)         Numeric Water Quality Standards for Other Chemical Constituents

 

            Concentrations of the following chemical constituents must not be exceeded except in waters for which mixing is allowed under Section 302.102.

 

Constituent	Unit	Standard
Chloride	mg/L	500
Iron (dissolved)	mg/L	1.0
Selenium (total)	mg/L	1.0
Silver (dissolved)	µg/L	eA+B ln(H) X 0.85*, where A=-6.52 and B=1.72
Sulfate (where H is ≥ 100 but ≤ 500 and C is ≥ 25 but ≤ 500)	mg/L	[1276.7+5.508(H)-1.457(C)] X 0.65
Sulfate (where H is ≥ 100 but ≤ 500 and C is ≥ 5 but < 25)	mg/L	[-57.478 + 5.79(H) + 54.163(C)] X 0.65
Sulfate (where H > 500 and C ≥ 5)	mg/L	2,000

 

where:

 

mg/L	=	milligram per liter
µg/L	=	microgram per liter
H	=	hardness concentration of receiving water in mg/L as CaCO3
C	=	chloride concentration of receiving water in mg/L
ex	=	base of natural logarithms raised to the x-power
ln(H)	=	natural logarithm of hardness in milligrams per liter
*	=	conversion factor multiplier for dissolved metals

 

h)         Concentrations of other chemical constituents in the South Fork of the South Branch of the Chicago River (Bubbly Creek) must not exceed the following standards:

 

CONSTITUENT	CONCENTRATION (mg/L)
Ammonia Un-ionized (as N*)	0.1
Arsenic (total)	1.0
Barium (total)	5.0
Cadmium (total)	0.15
Chromium (total hexavalent)	0.3
Chromium (total trivalent)	1.0
Copper (total)	1.0
Cyanide (total)	0.10
Fluoride (total)	15.0
Iron (total)	2.0
Iron (dissolved)	0.5
Lead (total)	0.1
Manganese (total)	1.0
Mercury (total)	0.0005
Nickel (total)	1.0
Oil, fats and grease	15.0**
Phenols	0.3
Selenium (total)	1.0
Silver	1.1
Zinc (total)	1.0
Total Dissolved Solids	1500

 

*   For purposes of this Section, the concentration of un-ionized ammonia must be computed according to the following equation:

 

 

where:

 

X	=
U	=	Concentration of un-ionized ammonia as N in mg/L
N	=	Concentration of ammonia nitrogen as N in mg/L
T	=	Temperature in degrees Celsius

 

**        Oil must be analytically separated into polar and non-polar components if the total concentration exceeds 15 mg/L.  In no case may either of the components exceed 15 mg/L (i.e., 15 mg/L polar materials and 15 mg/L non-polar materials).

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.408  Temperature

 

a)         For the South Fork of the South Branch of the Chicago River (Bubbly Creek), the temperature must not exceed 34 ºC (93 ºF) more than 5% of the time, or 37.8 ºC (100 ºF) at any time.

 

b)         The temperature standards in subsections (c) through (i) will become applicable beginning July 1, 2018.

 

c)         There must not be any abnormal temperature changes that may adversely affect aquatic life unless caused by natural conditions.

 

d)         The normal daily and seasonal temperature fluctuations that existed before the addition of heat due to other than natural causes must be maintained.

 

e)         The maximum temperature rise above natural temperatures must never exceed 2.8 °C (5 °F).

 

f)         Water temperature at representative locations in the main river must never exceed the maximum limits in the applicable table in subsections (g), (h) and (i), during more than one percent of the hours in the 12-month period ending with any month.  The water temperature must not exceed the maximum limits in the applicable table that follows by more than 1.7 °C (3.0 °F).

 

g)         Water temperature in the Chicago Area Waterway System Aquatic Life Use A waters listed in 35 Ill. Adm. Code 303.235 must not exceed the limits in the following table in compliance with subsection (f):

 

 

h)         Water temperature in the Chicago Area Waterway System and Brandon Pool Aquatic Life Use B waters listed in 35 Ill. Adm. Code 303.240 must not exceed the limits in the following table in compliance with subsection (f):

 

 

i)          Water temperature for the Upper Dresden Island Pool Aquatic Life Use waters, as defined in 35 Ill. Adm. Code 303.230, must not exceed the limits in the following table in compliance with subsection (f):

 

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.409  Cyanide for the South Fork of the South Branch of the Chicago River (Bubbly Creek)

 

Cyanide (total) must not exceed 0.10 mg/L in the South Fork of the South Branch of the Chicago River (Bubbly Creek).

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.410  Other Toxic Substances

 

Any substance or combination of substances toxic to aquatic life not listed in Section 302.407 must not exceed one-half of the 96-hour median tolerance limit (96-hour TL_m) for native fish or essential fish food organisms in the South Fork of the South Branch of the Chicago River (Bubbly Creek).  All other Chicago Area Waterway System and Lower Des Plaines River waters as designated in 35 Ill. Adm. Code 303 must be free from any substances or combination of substances in concentrations toxic or harmful to human health or animal, plant, or aquatic life.  Individual chemical substances or parameters for which numeric standards are specified in this Subpart are not subject to this Section.

 

a)         Any substance or combination of substances will be deemed to be toxic or harmful to aquatic life if present in concentrations that exceed the following:

 

1)         An Acute Aquatic Toxicity Criterion (AATC) validly derived and correctly applied under procedures in Sections 302.612 through 302.618 or in Section 302.621; or

 

2)         A Chronic Aquatic Toxicity Criterion (CATC) validly derived and correctly applied under procedures in Section 302.627 or 302.630.

 

b)         Any substance or combination of substances will be deemed to be toxic or harmful to wild or domestic animal life if present in concentrations that exceed any Wild and Domestic Animal Protection Criterion (WDAPC) validly derived and correctly applied under Section 302.633.

 

c)         Any substance or combination of substances will be deemed to be toxic or harmful to human health if present in concentrations that exceed criteria, validly derived and correctly applied, based on either of the following:

 

1)         Disease or functional impairment due to a physiological mechanism for which there is a threshold dose below which no damage occurs calculated under Sections 302.642 through 302.648 (Human Threshold Criterion); or

 

2)         Disease or functional impairment due to a physiological mechanism for which any dose may cause some risk of damage calculated under Sections 302.651 through 302.658 (Human Nonthreshold Criterion).

 

d)         The most stringent criterion of subsections (a), (b), and (c) applies at all points outside of any waters within which mixing is allowed under Section 302.102.  In addition, the AATC derived under subsection (a)(1) applies in all waters except that it must not apply within a ZID that is prescribed in compliance with Section 302.102.

 

e)         The procedures of Subpart F set forth minimum data requirements, appropriate test protocols, and data assessment methods for establishing criteria under subsections (a), (b), and (c).  No other procedures may be used to establish these criteria unless approved by the Board in a rulemaking or adjusted standard proceeding under Title VII of the Act.  The validity and applicability of the Subpart F procedures may not be challenged in any proceeding brought under Title VIII or X of the Act, although the validity and correctness of application of the numeric criteria derived under Subpart F may be challenged in the proceedings under subsection (f).

 

f)         Agency derived criteria may be challenged as follows:

 

1)         A permittee may challenge the validity and correctness of application of a criterion derived by the Agency under this Section only at the time the criterion is first applied in an NPDES permit under 35 Ill. Adm. Code 309.152 or in an action under Title VIII of the Act for violation of the toxicity water quality standard.  Failure of a person to challenge the validity of a criterion at the time of its first application constitutes a waiver of the challenge in any subsequent proceeding involving the application of the criterion to that person.

 

2)         Consistent with subsection (f)(1), if a criterion is included as, or is used to derive, a condition of an NPDES discharge permit, a permittee may challenge the criterion in a permit appeal under Section 40 of the Act and 35 Ill. Adm. Code 309.181.  In any such action, the Agency must include in the record all information upon which it has relied in developing and applying the criterion, whether that information was developed by the Agency or submitted by the petitioner.  The burden of proof is on the petitioner to demonstrate that the criterion-based condition is not necessary to accomplish the purposes of subsection (f)(1) (see Section 40(a)(1) of the Act), but there is no presumption in favor of the general validity and correctness of the application of the criterion as reflected in the challenged condition.

 

3)         Consistent with subsection (f)(1), in an action in which the alleged violation of the toxicity water quality standard is based on an alleged excursion of a criterion, the person bringing the action has the burdens of going forward with proof and of persuasion regarding the general validity and correctness of application of the criterion.

 

g)         Subsections (a) through (e) do not apply to USEPA registered pesticides approved for aquatic application and applied under the following conditions:

 

1)         Application must be made in strict compliance with label directions;

 

2)         Applicator must be properly certified under the provisions of the Federal Insecticide, Fungicide, and Rodenticide Act (7 U.S.C.136 et seq); and

 

3)         Applications of aquatic pesticides must comply with the laws, regulations, and guidelines of all state and federal agencies authorized by law to regulate, use, or supervise pesticide applications.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.412  Total Ammonia Nitrogen

 

a)         This Section does not apply to the South Fork of the South Branch of the Chicago River (Bubbly Creek).

 

b)         For the Chicago Area Waterway System and the Lower Des Plaines River described in 35 Ill. Adm. Code 303.204 and listed in 35 Ill. Adm. Code 303.220 through 303.240, total ammonia nitrogen must in no case exceed 15 mg/L.

 

c)         The total ammonia nitrogen acute, chronic, and sub-chronic standards are determined in compliance with the equations in subsections (c)(1) and (c)(2).  Attainment of each standard must be determined in compliance with subsections (d) and (e) in mg/L.

 

1)         The acute standard (AS) is calculated using the following equation: 

 

 

2)         The chronic standard (CS) is calculated using the following equations:

 

A)        During the Early Life Stage Present period, as defined in subsection (f):

 

i)          When the water temperature is less than or equal to 14.51 ºC:

 

 

ii)         When the water temperature is above 14.51 ºC:

 

 

where:

 

T

=

Water Temperature, degrees Celsius

 

B)        During the Early Life Stage Absent period, as defined in subsection (f):

 

i)          When the water temperature is less than or equal to 7 ºC:

 

 

ii)         When the water temperature is greater than 7 ºC:

 

 

Where:

 

T

=

Water Temperature, degrees Celsius

 

3)         The sub-chronic standard is equal to 2.5 times the chronic standard.

 

d)         Attainment of the Total Ammonia Nitrogen Water Quality Standards

 

1)         The acute standard for total ammonia nitrogen (in mg/L) must not be exceeded at any time except in those waters for which the Agency has approved a ZID under Section 302.102.

 

2)         The 30-day average concentration of total ammonia nitrogen (in mg/L) must not exceed the chronic standard (CS) except in those waters in which mixing is allowed under Section 302.102.  Attainment of the chronic standard (CS) is determined in compliance with subsection (e) by averaging at least four samples collected at weekly intervals or at other sampling intervals that statistically represent a 30-day sampling period.  The samples must be collected in a manner that assures a representative sampling period.

 

3)         The 4-day average concentration of total ammonia nitrogen (in mg/L) must not exceed the sub-chronic standard is except in those waters in which mixing is allowed under Section 302.102.  Attainment of the sub-chronic standard is determined in compliance with subsection (e) by averaging daily sample results collected over four consecutive days within the 30-day averaging period.  The samples must be collected in a manner that assures a representative sampling period.

 

e)         The water quality standard for each water body must be calculated based on the temperature and pH of the water body measured at the time of each ammonia sample.  The concentration of total ammonia in each sample must be divided by the calculated water quality standard for the sample to determine a quotient.  The water quality standard is attained if the mean of the sample quotients is less than or equal to one for the duration of the averaging period.

 

f)         The Early Life Stage Present period occurs from March through October.  All other periods are subject to the Early Life Stage Absent period, except that waters listed in 35 Ill. Adm. Code 303.240 are not subject to Early Life Stage Present ammonia limits at any time.

 

BOARD NOTE:  Acute and chronic standard concentrations for total ammonia nitrogen (in mg/L) for different combinations of pH and temperature are shown in Appendix C.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.501  Scope, Applicability, and Definitions

 

a)         Subpart E contains the Lake Michigan Basin water quality standards.  These must be met in the waters of the Lake Michigan Basin as designated in 35 Ill. Adm. Code 303.443.

 

b)         In addition to the definitions provided at 35 Ill. Adm. Code 301.200 through 301.444, and in place of conflicting definitions at Section 302.100, the following terms have the meanings specified for the Lake Michigan Basin:

 

"Acceptable daily exposure" or "ADE" means an estimate of the maximum daily dose of a substance that is not expected to result in adverse noncancerous effects to the general human population, including sensitive subgroups.

 

"Acceptable endpoints", for the purpose of deriving wildlife criteria, means acceptable subchronic and chronic endpoints that affect reproductive or developmental success, organismal viability or growth, or any other endpoint that is, or is directly related to, parameters that influence population dynamics.

 

"Acute to chronic ratio" or "ACR" is the standard measure of the acute toxicity of a material divided by an appropriate measure of the chronic toxicity of the same material under comparable conditions.

 

"Acute toxicity" means adverse effects that result from an exposure period that is a small portion of the life span of the organism.

 

"Adverse effect" means any deleterious effect to organisms due to exposure to a substance.  This includes effects that are or may become debilitating, harmful, or toxic to the normal functions of the organism, but does not include non-harmful effects such as tissue discoloration alone or the induction of enzymes involved in the metabolism of the substance.

 

"Baseline BAF" for organic chemicals, means a bioaccumulation factor (BAF) that is based on the concentration of a freely dissolved chemical in the ambient water and takes into account the partitioning of the chemical within the organism; for inorganic chemicals, a BAF is based on the wet weight of the tissue.

 

"Baseline BCF" for organic chemicals, means a bioconcentration factor (BCF) that is based on the concentration of a freely dissolved chemical in the ambient water and takes into account the partitioning of the chemical within the organism; for inorganic chemicals, a BCF is based on the wet weight of the tissue.

 

"Bioaccumulative chemical of concern" or "BCC" is any chemical that has the potential to cause adverse effects and that, upon entering the surface waters, by itself or as its toxic transformation product, accumulates in aquatic organisms by a human health bioaccumulation factor greater than 1,000, after considering metabolism and other physiochemical properties that might enhance or inhibit bioaccumulation based on the methodology in Section 302.570.  In addition, the half-life of the chemical in the water column, sediment, or biota must be greater than eight weeks.  BCCs include the following substances:

 

Chlordane

 

4,4'-DDD; p,p'-DDD; 4,4'-TDE; p,p'-TDE

 

4,4'-DDE; p,p'-DDE

 

4,4'-DDT; p,p'-DDT

 

Dieldrin

 

Hexachlorobenzene

 

Hexachlorobutadiene; Hexachloro-1,3-butadiene

 

Hexachlorocyclohexanes; BHCs

 

alpha-Hexachlorocyclohexane; alpha-BHC

 

beta-Hexachlorocyclohexane; beta-BHC

 

delta-Hexachlorocyclohexane; delta-BHC

 

Lindane; gamma-Hexachlorocyclohexane; gamma-BHC

 

Mercury

 

Mirex

 

Octachlorostyrene

 

PCBs; polychlorinated biphenyls

 

Pentachlorobenzene

 

Photomirex

 

2,3,7,8-TCDD; Dioxin

 

1,2,3,4-Tetrachlorobenzene

 

1,2,4,5-Tetrachlorobenzene

 

Toxaphene

 

"Bioaccumulation" is the net accumulation of a substance by an organism as a result of uptake from all environmental sources.

 

"Bioaccumulation factor" or "BAF" is the ratio (in L/kg) of a substance's concentration in the tissue of an aquatic organism to its concentration in the ambient water, in situations where both the organism and its food are exposed and the ratio does not change substantially over time.

 

"Bioconcentration" means the net accumulation of a substance by an aquatic organism as a result of uptake directly from the ambient water through gill membranes or other external body surfaces.

 

"Bioconcentration Factor" or "BCF" is the ratio (in L/kg) of a substance's concentration in the tissue of an aquatic organism to its concentration in the ambient water, in situations where the organism is exposed through the water only and the ratio does not change substantially over time.

 

"Biota-sediment accumulation factor" or "BSAF" means the ratio (in kg of organic carbon/kg of lipid) of a substance's lipid-normalized concentration in the tissue of an aquatic organism to its organic carbon-normalized concentration in surface sediment, in situations where the ratio does not change substantially over time, both the organism and its food are exposed, and the surface sediment is representative of average surface sediment in the vicinity of the organism.

 

"Carcinogen" means a substance that causes an increased incidence of benign or malignant neoplasms, or substantially decreases the time to develop neoplasms, in animals or humans.  The classification of carcinogens is determined by the procedures in Section II.A of Appendix C to 40 CFR 132, incorporated by reference in 35 Ill. Adm. Code 301.106.

 

"Chronic effect" means an adverse effect that is measured by assessing an acceptable endpoint, and results from continual exposure over several generations, or at least over a significant part of the test species' projected life span or life stage.

 

"Chronic toxicity" means adverse effects that result from an exposure period that is a large portion of the life span of the organism.

 

"Dissolved organic carbon" or "DOC" means organic carbon that passes through a 1 µm pore size filter.

 

"Dissolved metal" means the concentration of a metal that will pass through a 0.45 µm pore size filter.

 

"Food chain" means the energy stored by plants is passed along through the ecosystem through trophic levels in a series of steps of eating and being eaten, also known as a food web.

 

"Food chain multiplier" or "FCM" means the ratio of a BAF to an appropriate BCF.

 

"Linearized multi-stage model" means a mathematical model for cancer risk assessment.  This model fits linear dose-response curves to low doses.  It is consistent with a no-threshold model of carcinogenesis.

 

"Lowest observed adverse effect level" or "LOAEL" means the lowest tested dose or concentration of a substance that results in an observed adverse effect in exposed test organisms when all higher doses or concentrations result in the same or more severe effects.

 

"No observed adverse effect level" or "NOAEL" means the highest tested dose or concentration of a substance that results in no observed adverse effect in exposed test organisms where higher doses or concentrations result in an adverse effect.

 

"Octanol-water partition coefficient" or "Kow" is the ratio of the concentration of a substance in the n-octanol phase to its concentration in the aqueous phase in an equilibrated two-phase octanol-water system.  For log Kow, the log of the octanol-water partition coefficient is a base 10 logarithm.

 

"Open Waters of Lake Michigan" means all of the waters within Lake Michigan in Illinois jurisdiction lakeward from a line drawn across the mouth of tributaries to Lake Michigan, but not including waters enclosed by constructed breakwaters.

 

"Particulate organic carbon" or "POC" means organic carbon that is retained by a 1 µm pore size filter.

 

"Relative source contribution" or "RSC" means the percentage of total exposure that can be attributed to surface water through water intake and fish consumption.

 

"Resident or indigenous species" means species that currently live a substantial portion of their life cycle or reproduce in a given body of water or that are native species whose historical range includes a given body of water.

 

"Risk associated dose" or "RAD" means a dose of a known or presumed carcinogenic substance in mg/kg/day that, over a lifetime of exposure, is estimated to be associated with a plausible upper bound incremental cancer risk equal to one in 100,000.

 

"Slope factor" or "q₁*" is the incremental rate of cancer development calculated by a linearized multistage model or another appropriate model.  It is expressed in mg/kg/day of exposure to the chemical in question.

 

"Standard Methods" means "Standard Methods for the Examination of Water and Wastewater", available from the American Public Health Association.

 

"Subchronic effect" means an adverse effect, measured by assessing an acceptable endpoint, resulting from continual exposure for a period of time less than that deemed necessary for a chronic test.

 

"Target species" is a species to be protected by the criterion.

 

"Target species value" is the criterion value for the target species.

 

"Test species" is a species that has test data available to derive a criterion.

 

"Test dose" or "TD" is a LOAEL or NOAEL for the test species.

 

"Tier I criteria" are numeric values derived by use of the Tier I methodologies that either have been adopted as numeric criteria into a water quality standard or are used to implement narrative water quality criteria.

 

"Tier II values" are numeric values derived by use of the Tier II methodologies that are used to implement narrative water quality criteria. They are applied as criteria, have the same effect, and are subject to the same appeal rights as criteria.

 

"Trophic level" means a functional classification of taxa within a community that is based on feeding relationships.  For example, aquatic green plants and herbivores comprise the first and second trophic levels in a food chain.

 

"Toxic unit acute" or "TU_a" is the reciprocal of the effluent concentration that causes 50 percent of the test organisms to die by the end of the acute exposure period, which is 48 hours for invertebrates and 96 hours for vertebrates.

 

"Toxic unit chronic" or "TU_c" is the reciprocal of the effluent concentration that causes no observable effect on the test organisms by the end of the chronic exposure period, which is at least seven days for Ceriodaphnia, fathead minnow, and rainbow trout.

 

"Uncertainty factor" or "UF" is one of several numeric factors used in deriving criteria from experimental data to account for the quality or quantity of the available data.

 

"USEPA" means the United States Environmental Protection Agency.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.502  Dissolved Oxygen

 

Dissolved oxygen must not be less than 90% of saturation, except due to natural causes, in the Open Waters of Lake Michigan as defined at Section 302.501.  The other waters of the Lake Michigan Basin must not be less than 6.0 mg/L during at least 16 hours of any 24 hour period, nor less than 5.0 mg/L at any time.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.503  pH

 

pH must be within the range of 7.0 to 9.0, except due to natural causes, in the Open Waters of Lake Michigan as defined at Section 302.501.  Other waters of the Basin must be within the range of 6.5 to 9.0 except due to natural causes.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.504  Chemical Constituents

 

The following concentrations of chemical constituents must not be exceeded, except as provided in Sections 302.102 and 302.530:

 

a)         The following standards must be met in all waters of the Lake Michigan Basin.  Acute aquatic life standards (AS) must not be exceeded at any time except for those waters for which the Agency has approved a zone of initial dilution (ZID) under Sections 302.102 and 302.530.  Chronic aquatic life standards (CS) and human health standards (HHS) must not be exceeded outside of waters in which mixing is allowed under Sections 302.102 and 302.530 by the arithmetic average of at least four consecutive samples collected over at least four days.  The samples used to demonstrate compliance with the CS or HHS must be collected in a manner that assures an average representation of the sampling period.

 

Constituent	Unit	AS	CS	HHS
Arsenic (Trivalent, dissolved)	µg/L		148 x 1.0*=148	NA
Boron (total)	mg/L	40.1	7.6	NA
Cadmium (dissolved)	µg/L			NA
		(0.041838)]}*	(0.041838)]}*
		where A = -3.6867 and B = 1.128	where A = -2.715 and B = 0.7852
Chromium (Hexavalent, total)	µg/L	16	11	NA
Chromium (Trivalent, dissolved)	µg/L			NA
		0.316*	0.860*
		where A = 3.7256 and B = 0.819	where A = 0.6848 and B = 0.819
Copper (dissolved)	µg/L			NA
		0.960*	0.960*
		where A = -1.700 and B = 0.9422	where A = -1.702 and B = 0.8545
Cyanide**	µg/L	22	5.2	NA
Fluoride (total)	µg/L	where A = 6.7319 and B = 0.5394	, but must not exceed 4.0 mg/L	NA
			where A = 6.0445 and B = 0.5394
Lead (dissolved)	µg/L			NA
		(0.145712)]}*	(0.145712)]}*
		where A = -1.055 and B =1.273	where A = -4.003 and B = 1.273
Manganese (dissolved)	µg/L			NA
		where A = 4.9187 and B = 0.7467	where A = 4.0635 and B = 0.7467
Nickel (dissolved)	µg/L			NA
		0.998*	0.997*
		where A = 2.255 and B = 0.846	where A = 0.0584 and B = 0.846
Selenium (dissolved)	µg/L	NA	5.0	NA
TRC	µg/L	19	11	NA
Zinc (dissolved)	µg/L			NA
		0.978*	0.986*
		where A = 0.884 and B = 0.8473	where A = 0.884 and B = 0.8473
Benzene	µg/L	3900	800	310
Chlorobenzene	mg/L	NA	NA	3.2
2.4-Dimethylphenol	mg/L	NA	NA	8.7
2,4-Dinitrophenol	mg/L	NA	NA	2.8
Endrin	µg/L	0.086	0.036	NA
Ethylbenzene	µg/L	150	14	NA
Hexachloroethane	µg/L	NA	NA	6.7
Methylene chloride	mg/L	NA	NA	2.6
Parathion	µg/L	0.065	0.013	NA
Pentachlorophenol	µg/L			NA
		where A = -4.869 and B = 1.005	where A = -5.134 and B = 1.005
Toluene	µg/L	2000	610	51.0
Trichloroethylene	µg/L	NA	NA	370
Xylene(s)	µg/L	1200	490	NA

 

where:
	NA	=	Not Applied
	exp[x]	=	base of natural logarithms raised to the x-power
	ln(H)	=	natural logarithm of hardness in mg/L as CaCO3
	*	=	conversion factor multiplier for dissolved metals
	**	=	standard to be evaluated using either of the following USEPA approved methods, incorporated by reference at 35 Ill. Adm. Code 301.106:  Method OIA-1677, DW:  Available Cyanide by Flow Injection, Ligand Exchange, and Amperometry, January 2004, Document Number EPA-821-R-04-001; or Cyanide Amenable to Chlorination, Standard Methods 4500-CN-G (40 CFR 136.3).

 

b)         The following water quality standards must not be exceeded at any time in any waters of the Lake Michigan Basin unless a different standard is specified under subsection (c).

 

Constituent		Unit	Water Quality Standard
Barium (total)	01007	mg/L	5.0
Chloride (total)		mg/L	500
Iron (dissolved)		mg/L	1.0
Phenols		mg/L	0.1
Sulfate		mg/L	500
Total Dissolved Solids		mg/L	1000

 

c)         In addition to the standards specified in subsections (a) and (b), the following standards must not be exceeded at any time in the Open Waters of Lake Michigan as defined in Section 302.501.

 

Constituent	Unit	Water Quality Standard
Arsenic (total)	µg/L	50.0
Boron (total)	mg/L	1.0
Barium (total)	mg/L	1.0
Chloride (total)	mg/L	12.0
Fluoride (total)	mg/L	1.4
Iron (dissolved)	mg/L	0.30
Lead (total)	µg/L	50.0
Manganese (total)	mg/L	0.15
Nitrate-Nitrogen	mg/L	10.0
Phosphorus	µg/L	7.0
Selenium (total)	µg/L	10.0
Sulfate	mg/L	24.0
Total Dissolved Solids	mg/L	180.0
Oil (hexane solubles or equivalent)	mg/L	0.10
Phenols	µg/L	1.0

 

d)         In addition to the standards specified in subsections (a), (b), and (c), the following human health standards (HHS) must not be exceeded in the Open Waters of Lake Michigan as defined in Section 302.501 by the arithmetic average of at least four consecutive samples collected over at least four days.  The samples used to demonstrate compliance with the HHS must be collected in a manner that assures an average representation of the sampling period.

 

Constituent	Unit	Water Quality Standard
Benzene	µg/L	12.0
Chlorobenzene	µg/L	470.0
2,4-Dimethylphenol	µg/L	450.0
2,4-Dinitrophenol	µg/L	55.0
Hexachloroethane (total)	µg/L	5.30
Lindane	µg/L	0.47
Methylene chloride	µg/L	47.0
Trichloroethylene	µg/L	29.0

 

e)         For the following bioaccumulative chemicals of concern (BCCs), acute aquatic life standards (AS) must not be exceeded at any time in any waters of the Lake Michigan Basin and chronic aquatic life standards (CS), human health standards (HHS), and wildlife standards (WS) must not be exceeded in any waters of the Lake Michigan Basin by the arithmetic average of at least four consecutive samples collected over at least four days subject to the limitations of Sections 302.520 and 302.530.  The samples used to demonstrate compliance with the HHS and WS must be collected in a manner that assures an average representation of the sampling period.

 

Constituent	Unit	AS	CS	HHS	WS
Mercury (total)	ng/L	1,700	910	3.1	1.3
Chlordane	ng/L	NA	NA	0.25	NA
DDT and metabolites	pg/L	NA	NA	150	11.0
Dieldrin	ng/L	240	56	0.0065	NA
Hexachlorobenzene	ng/L	NA	NA	0.45	NA
Lindane	µg/L	0.95	NA	0.5	NA
PCBs (class)	pg/L	NA	NA	26	120
2,3,7,8-TCDD	fg/L	NA	NA	8.6	3.1
Toxaphene	pg/L	NA	NA	68	NA

 

where:
	mg/L	=	milligrams per liter (10-3 grams per liter)
	µg/L	=	micrograms per liter (10-6 grams per liter)
	ng/L	=	nanograms per liter (10-9 grams per liter)
	pg/L	=	picograms per liter (10-12 grams per liter)
	fg/L	=	femtograms per liter (10-15 grams per liter)
	NA	=	Not Applied

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.505  Fecal Coliform

 

Based on a minimum of five samples taken over not more than a 30-day period, fecal coliform must not exceed a geometric mean of 20 per 100 ml in the Open Waters of Lake Michigan as defined in Section 302.501.  The remaining waters of the Lake Michigan Basin must not exceed a geometric mean of 200 per 100 ml, nor may more than 10% of the samples during any 30-day period exceed 400 per 100 ml.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.506  Temperature

 

a)         The owner or operator of a source of heated effluent must maintain records and conduct studies of the effluents from the source and their effects as may be required by the Agency or in any permit granted under the Act.

 

b)         Backfitting of alternative cooling facilities will be required if, upon complaint filed in compliance with Board rules, it is found at any time that any heated effluent causes significant ecological damage to the Lake.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.507  Thermal Standards for Existing Sources on January 1, 1971

 

All sources of heated effluents in existence as of January 1, 1971, must meet the following restrictions outside of a mixing zone that is no greater than a circle with a radius of 305 m (1000 feet) or an equal fixed area of simple form.

 

a)         There must be no abnormal temperature changes that may affect aquatic life.

 

b)         The normal daily and seasonal temperature fluctuations that existed before the addition of heat must be maintained.

 

c)         The maximum temperature rise at any time above natural temperatures must not exceed 1.7 ºC (3 ºF).  In addition, the water temperature must not exceed the maximum limits indicated in the following table:

 

	° C	° F			° C	° F
JAN.	7	45		JUL.	27	80
FEB.	7	45		AUG.	27	80
MAR.	7	45		SEPT.	27	80
APR.	13	55		OCT.	18	65
MAY	16	60		NOV.	16	60
JUN.	21	70		DEC.	10	50

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.508  Thermal Standards for Sources Under Construction But Not In Operation on January 1, 1971

 

Any effluent source under construction but not in operation on January 1, 1971, must meet all the requirements of Section 302.507 and must meet the following restrictions:

 

a)         The bottom, the shore, the hypolimnion, and the thermocline must not be affected by any heated effluent.

 

b)         Heated effluent must not affect spawning grounds or fish migration routes.

 

c)         Discharge structures must be designed to maximize short-term mixing and thus to reduce the area significantly raised in temperature.

 

d)         Discharge must not exceed ambient temperatures by more than 11 ºC (20 ºF).

 

e)         Heated effluents from more than one source must not interact.

 

f)         All reasonable steps must be taken to reduce the number of organisms drawn into or against the intakes.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.509  Other Sources

 

a)         A source of heated effluent that was not in operation or under construction as of January 1, 1971, must not discharge more than a daily average of 29 megawatts (0.1 billion British thermal units per hour).

 

b)         Sources of heated effluents that discharge less than a daily average of 29 megawatts (0.1 billion British thermal units per hour) not in operation or under construction as of January 1, 1971, must meet all requirements of Sections 302.507 and 302.508.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.510  Incorporations by Reference (Repealed)

 

(Source:  Repealed at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.515  Offensive Conditions

 

Waters of the Lake Michigan Basin must be free from sludge or bottom deposits, floating debris, visible oil, odor, plant or algal growth, and color or turbidity of other than natural origin.  The allowed mixing provisions of Section 302.102 must not be used to comply with the provisions of this Section.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.520  Regulation and Designation of Bioaccumulative Chemicals of Concern (BCCs)

 

a)         For regulating BCCs in compliance with Sections 302.521 and 302.530, the following chemicals must be considered as BCCs:

 

1)         any chemical or class of chemicals listed as a BCC in Section 302.501; and

 

2)         any chemical or class of chemicals that the Agency has determined meets the characteristics of a BCC as defined in Section 302.501 as indicated by:

 

A)        publication in the Illinois Register;

 

B)        notification to a permittee or applicant; or

 

C)        filing a petition with the Board to verify that the chemical must be designated a BCC.

 

b)         Notwithstanding subsections (a)(2)(A) and (B), a chemical must not be regulated as a BCC if the Agency has not filed a petition, within 60 days after the publication or notification, with the Board in compliance with Section 28.2 of the Act to verify that the chemical must be designated a BCC.

 

c)         Under subsection (b) and Section 302.570, if the Board verifies that a chemical has a human health bioaccumulation factor greater than 1,000 and is consistent with the definition of a BCC in 35 Ill. Adm. Code 302.501, the Board will designate the chemical as a BCC and list the chemical in Section 302.501.  If the Board fails to verify the chemical as a BCC in its final action on the verification petition, the chemical must not be listed as a BCC and must not be regulated as a BCC in compliance with Sections 302.521 and 302.530.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.521  Supplemental Antidegradation Provisions for BCCs

 

a)         Notwithstanding the provisions of Section 302.105, waters within the Lake Michigan Basin must not be lowered in quality due to new or increased loading of substances defined as BCCs in Section 302.501 from any source or activity subject to the NPDES permitting, Section 401 water quality certification provisions of the Clean Water Act (33 U.S.C. 1341), or joint permits from the Agency and the Illinois Department of Natural Resources under Section 39(n) of the Act [415 ILCS 5/39(n)] until and unless it can be affirmatively demonstrated that the change is necessary to accommodate important economic or social development.

 

1)         Where ambient concentrations of a BCC are equal to or exceed an applicable water quality criterion, no increase in loading of that BCC is allowed.

 

2)         Where ambient concentrations of a BCC are below the applicable water quality criterion, a demonstration to justify increased loading of that BCC must include the following:

 

A)        Pollution Prevention Alternatives Analysis.  Identify any cost-effective reasonably available pollution prevention alternatives and techniques that would eliminate or significantly reduce the extent of increased loading of the BCC.

 

B)        Alternative or Enhanced Treatment Analysis.  Identify alternative or enhanced treatment techniques that are cost-effective and reasonably available to the entity that would eliminate or significantly reduce the extent of increased loading of the BCC.

 

C)        Important Social or Economic Development Analysis.  Identify the social or economic development and the benefits that would be forgone if the increased loading of the BCC is not allowed.

 

3)         In no case will increased loading of BCCs result in exceeding applicable water quality criteria or concentrations exceeding the level of water quality necessary to protect existing uses.

 

4)         Changes in loadings of any BCC within the existing capacity and processes of an existing NPDES authorized discharge, certified activity under Section 401 of the Clean Water Act, or joint permits from the Agency and the Illinois Department of Natural Resources under Section 39(n) of the Act are not subject to the antidegradation review of subsection (a). These changes include:

 

A)        normal operational variability, including intermittent increased discharges due to wet weather conditions;

 

B)        changes in intake water pollutants;

 

C)        increasing the production hours of the facility; or

 

D)        increasing the rate of production.

 

5)         Any determination to allow increased loading of a BCC based on a demonstration of important economic or social development need must satisfy the public participation requirements of 40 CFR 25 before final issuance of the NPDES permit, Section 401 water quality certification, or joint permits from the Agency and the Illinois Department of Natural Resources under Section 39(n) of the Act.

 

b)         The following actions are not subject to the provisions of subsection (a) unless the Agency determines the circumstances of an individual situation warrant application of those provisions to adequately protect water quality:

 

1)         Short-term, temporary (i.e., weeks or months) lowering of water quality;

 

2)         Bypasses that are not prohibited at 40 CFR 122.41(m), incorporated by reference in 35 Ill. Adm. Code 301.106; or

 

3)         Response actions under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended, or similar federal or State authority, undertaken to alleviate a release into the environment of hazardous substances, pollutants, or contaminants that pose danger to public health or welfare.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.525  Radioactivity

 

Except as provided in Section 302.102, all waters of the Lake Michigan Basin must meet the following concentrations:

 

a)         Gross beta concentrations must not exceed 100 picocuries per liter (pCi/L).

 

b)         Strontium 90 concentration must not exceed 2 picocuries per liter (pCi/L).

 

c)         The annual average radium 226 and 228 combined concentration must not exceed 3.75 picocuries per liter (pCi/L).

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.530  Supplemental Mixing Provisions for Bioaccumulative Chemicals of Concern (BCCs)

 

The Allowed Mixing, Mixing Zones, and ZIDs provisions of Section 302.102 apply within the Lake Michigan Basin except as otherwise provided for substances defined as BCCs in Section 302.501.  Mixing is not allowed for BCCs for new discharges commencing on or after December 24, 1997.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.535  Ammonia Nitrogen

 

The Open Waters of Lake Michigan as defined in Section 302.501 must not exceed 0.02 mg/L total ammonia (as N).  The remaining waters of the Lake Michigan Basin are subject to the following:

 

a)         Total ammonia nitrogen (as N) must in no case exceed 15 mg/L.

 

b)         Un-ionized ammonia nitrogen (as N) must not exceed the acute and chronic standards given below subject to the provisions of Section 302.208(a) and (b):

 

1)         From April through October, the Acute Standard (AS) must be 0.33 mg/L and the chronic standard (CS) must be 0.057 mg/L.

 

2)         From November through March, the AS must be 0.14 mg/L and the CS must be 0.025 mg/L.

 

c)         For this Section, the concentration of un-ionized ammonia nitrogen as N and total ammonia as N must be computed according to the following equations:

 

U	=	N
		[0.94412(1 + 10x) + 0.0559]

 

and N = U[0.94412(1 + 10^x) + 0.0559]

 

Where:

 

X	=	0.09018	+	2729.92	-pH
				(T + 273.16)
U	=	Concentration of un-ionized ammonia as N in mg/L
N	=	Concentration of ammonia nitrogen as N in mg/L
T	=	Temperature in degrees Celsius.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.540  Other Toxic Substances

 

Waters of the Lake Michigan Basin must be free from any substance or any combination of substances in concentrations toxic or harmful to human health or animal, plant, or aquatic life.  The numeric standards protective of particular uses specified for individual chemical substances in Section 302.504 are not subject to recalculation by this Section; however, where no standard applies to a category, a numeric value may be calculated.

 

a)         Any substance will be deemed toxic or harmful to aquatic life if present in concentrations that exceed the following:

 

1)         A Tier I Lake Michigan Basin Acute Aquatic Life Toxicity Criterion (LMAATC) or Tier II Lake Michigan Basin Acute Aquatic Life Toxicity Value (LMAATV) derived under procedures in Sections 302.555, 302.560 or 302.563 at any time; or

 

2)         A Tier I Lake Michigan Basin Chronic Aquatic Life Toxicity Criterion (LMCATC) or Tier II Lake Michigan Basin Chronic Aquatic Life Toxicity Value (LMCATV) derived under procedures in Section 302.565 as an average of four samples collected on four different days.

 

b)         Any combination of substances, including effluents, will be deemed toxic to aquatic life if present in concentrations that exceed either subsection (b)(1) or (b)(2):

 

1)         A sample of water from the Lake Michigan Basin collected outside of a designated zone of initial dilution must not exceed 0.3 TU_a as determined for the most sensitive species tested using acute toxicity testing methods.

 

2)         A sample of water from the Lake Michigan Basin collected outside a designated mixing zone must not exceed 1.0 TU_c as determined for the most sensitive species tested using chronic toxicity testing methods.

 

3)         To demonstrate compliance with subsections (b)(1) and (b)(2), at least two resident or indigenous species must be tested. The rainbow trout must be used to represent fish for the Open Waters of Lake Michigan and the fathead minnow must represent fish for the other waters of the Lake Michigan Basin.  Ceriodaphnia must represent invertebrates for all waters of the Lake Michigan Basin.  Other common species may be used if listed in Table I (a) of 40 CFR 136, incorporated by reference at 35 Ill. Adm. Code 301.106, and approved by the Agency.

 

c)         Any substance must be deemed toxic or harmful to wildlife if present in concentrations that exceed a Tier I Lake Michigan Basin Wildlife Criterion (LMWLC) derived under procedures in Section 302.575 as an arithmetic average of four samples collected over four different days.

 

d)         For any substance that is a threat to human health through drinking water exposure only, the resulting criterion or value must apply to only the Open Waters of Lake Michigan.  For any substance that is determined to be a BCC, the resulting criterion must apply to the entire Lake Michigan Basin.  These substances must be deemed toxic or harmful to human health if present in concentrations that exceed either of the following:

 

1)         A Tier I Lake Michigan Basin Human Health Threshold Criterion (LMHHTC) or Tier II Lake Michigan Basin Human Health Threshold Value (LMHHTV) based on disease or functional impairment due to a physiological mechanism for which there is a threshold dose below which no damage occurs as derived under procedures in Section 302.585 as an arithmetic average of four samples collected over four different days; or

 

2)         A Tier I Lake Michigan Basin Human Health Nonthreshold Criterion (LMHHNC) or Tier II Lake Michigan Basin Human Health Nonthreshold Value (LMHHNV) based on disease or functional impairment due to a physiological mechanism for which any dose may cause some risk of damage as derived under procedures in Section 302.590 as an arithmetic average of four samples collected over four different days.

 

e)         The derived criteria and values apply at all points outside of any waters in which mixing is allowed under Section 302.102 or 302.530.

 

f)         The procedures of this Subpart E set forth minimum data requirements, appropriate test protocols, and data assessment methods for establishing criteria or values under subsections (b), (c), and (d). No other procedures may be used to establish these criteria or values unless approved by the Board in a rulemaking or adjusted standard proceeding under Title VII of the Act.  The validity and applicability of these procedures may not be challenged in any proceeding brought under Title VIII or X of the Act, although the validity and correctness of application of the numeric criteria or values derived under this Subpart may be challenged in proceedings under subsection (g).

 

g)         Challenges to Applying Criteria and Values

 

1)         A permittee may challenge the validity and correctness of application of a criterion or value derived by the Agency under this Section only at the time the criterion or value is first applied in its NPDES permit under 35 Ill. Adm. Code 309.152 or in an action under Title VIII of the Act for violation of the toxicity water quality standard.  Failure of a person to challenge the validity of a criterion or value at the time of its first application to that person's facility constitutes a waiver of a challenge in any subsequent proceeding involving an application of the criterion or value to that person.

 

2)         Consistent with subsection (g)(1), if a criterion or value is included as, or is used to derive, a condition of an NPDES discharge permit, a permittee may challenge the criterion or value in a permit appeal under 35 Ill. Adm. Code 309.181. 

 

3)         Consistent with subsection (g)(1), in an action when the alleged violation of the toxicity water quality standard is based on an alleged excursion of a criterion or value, the person bringing the action has the burdens of going forward with proof and persuasion regarding the general validity and correctness of application of the criterion or value.

 

h)         Subsections (a) through (e) do not apply to USEPA registered pesticides approved for aquatic application and applied under the following conditions:

 

1)         Application must be made in strict compliance with label directions;

 

2)         Applicator must be properly certified under the provisions of the Federal Insecticide, Fungicide, and Rodenticide Act (7 U.S.C. 136 et seq.);

 

3)         Applications of aquatic pesticides must comply with the laws, regulations and guidelines of all State and federal agencies authorized by law to regulate, use or supervise pesticide applications;

 

4)         Aquatic pesticides must not be applied to waters affecting public or food processing water supplies unless a permit to apply the pesticide has been obtained from the Agency.  All permits must be issued so as not to cause a violation of the Act or any of the Board's rules.  To aid applicators in determining their responsibilities under this subsection (h), a list of waters affecting public water supplies must be published and maintained by the Agency's Division of Public Water Supplies.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.545  Data Requirements

 

The Agency must review for validity, applicability, and completeness the data used in calculating criteria or values.  To the extent available and not otherwise specified, testing procedures, selection of test species, and other aspects of data acquisition must use methods published by USEPA or nationally recognized standards of organizations, including those methods found in Standard Methods, incorporated by reference in 35 Ill. Adm. Code 301.106, or recommended in 40 CFR 132, incorporated by reference in 35 Ill. Adm. Code 301.106.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.550  Analytical Testing

 

All methods of sample collection, preservation, and analysis used in applying any of the requirements of this Subpart must be consistent with the methods published by USEPA or nationally recognized standards of organizations, including those methods found in Standard Methods, incorporated by reference in 35 Ill. Adm. Code 301.106, or recommended in 40 CFR 132, incorporated by reference in 35 Ill. Adm. Code 301.106.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.553  Determining the Lake Michigan Aquatic Toxicity Criteria or Values − General Procedures

 

The Lake Michigan Aquatic Life Criteria and Values are those concentrations or levels of a substance at which aquatic life is protected from adverse effects resulting from short- or long-term exposure in water.

 

a)         Tier I criteria and Tier II values to protect against acute effects in aquatic organisms will be calculated according to procedures listed at Sections 302.555, 302.560, and 302.563.  The procedures of Section 302.560 must be used as necessary to allow for interactions with other water quality characteristics such as hardness, pH, or temperature.  Tier I criteria and Tier II values to protect against chronic effects in aquatic organisms must be calculated according to the procedures listed at Section 302.565.

 

b)         Minimum Data Requirements.  To derive a Tier I acute or chronic criterion, data must be available for at least one species of freshwater animal in at least eight different families such that the following taxa are included:

 

1)         The family Salmonidae in the class Osteichthyes;

 

2)         One other family in the class Osteichthyes;

 

3)         A third family in the phylum Chordata;

 

4)         A planktonic crustacean;

 

5)         A benthic crustacean;

 

6)         An insect;

 

7)         A family in a phylum other than Arthropoda or Chordata; and

 

8)         A family from any order of insect or any phylum not already represented.

 

c)         Data for tests with plants, if available, must be included in the data set.

 

d)         If data for acute effects are not available for all the eight families listed above, but are available for the family Daphnidae, a Tier II value must be derived according to procedures in Section 302.563.  If data for chronic effects are not available for all the eight families, but there are acute and chronic data available according to Section 302.565(b) so that three acute to chronic ratios (ACRs) can be calculated, then a Tier I chronic criterion can be derived according to procedures in Section 302.565.  If three ACRs are not available, then a Tier II chronic value can be derived according to procedures in Section 302.565(b).

 

e)         Data must be obtained from species that have reproducing wild populations in North America except that data from saltwater species can be used in the derivation of an ACR.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.555  Determining the Tier I Lake Michigan Acute Aquatic Toxicity Criterion (LMAATC):  Independent of Water Chemistry

 

If the acute toxicity of the chemical has not been shown to be related to a water quality characteristic, including hardness, pH, or temperature, the Tier I LMAATC is calculated using the procedures below.

 

a)         For each species for which more than one acute value is available, the Species Mean Acute Value (SMAV) is calculated as the geometric mean of the acute values from all tests.

 

b)         For each genus for which one or more SMAVs are available, the Genus Mean Acute Value (GMAV) is calculated as the geometric mean of the SMAVs available for the genus.

 

c)         The GMAVs are ordered from high to low in numerical order.

 

d)         Ranks (R) are assigned to the GMAVs from "1" for the lowest to "N" for the highest.  If two or more GMAVs are identical, successive ranks are arbitrarily assigned.

 

e)         The cumulative probability, P, is calculated for each GMAV as R/(N+1).

 

f)         The GMAVs to be used in the calculations of subsection (g) must be those with cumulative probabilities closest to 0.05.  If there are fewer than 59 GMAVs in the total data set, the values utilized must be the lowest four obtained through the ranking procedures of subsections (c) and (d).

 

g)         Using the GMAVs identified under subsection (f) and the Ps calculated under subsection (e), the Final Acute Value (FAV) and the LMAATC are calculated as:

 

FAV = exp(A) and

LMAATC = FAV/2

 

Where:

 

A	=	L + 0.2236 S
L	=	[Σ(lnGMAV) – S(Σ(P(0.5)))]/4
S	=	[[Σ((lnGMAV)2) - ((Σ(lnGMAV))2)/4] / [Σ(P) - ((Σ(P0.5))2)/4]]0.5

 

h)         If a resident or indigenous species whose presence is necessary to sustain commercial or recreational activities will not be protected by the calculated FAV, then the SMAV for that species is used as the FAV.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.560  Determining the Tier I Lake Michigan Basin Acute Aquatic Life Toxicity Criterion (LMAATC):  Dependent on Water Chemistry

 

If data are available to show that a relationship exists between a water quality characteristic (WQC) and acute toxicity to two or more species, a Tier I LMAATC must be calculated using procedures in this Section.  Although the relationship between hardness and acute toxicity is typically non-linear, it can be linearized by a logarithmic transformation (i.e., for any variable, K, f(K) = logarithm of K) of the variables and plotting the logarithm of hardness against the logarithm of acute toxicity.  Similarly, relationships between acute toxicity and other water quality characteristics, such as pH or temperature, may require a transformation, including no transformation (i.e., for any variable, K, f(K) = K), for one or both variables to obtain a least squares linear regression of the transformed acute toxicity values on the transformed values of the water quality characteristic.  An LMAATC is calculated using the following procedures.

 

a)         For each species for which acute toxicity values are available at two or more different values of the water quality characteristic, a least squares linear regression of the transformed acute toxicity (TAT) values on the transformed water quality characteristic (TWQC) values is performed to obtain the slope of the line describing the relationship.

 

b)         Each of the slopes determined under subsection (a) is evaluated as to whether it is statistically valid, considering the range and number of tested values of the water quality characteristic and the degree of agreement within and between species.  If slopes are not available for at least one fish and one invertebrate species, the available slopes are too dissimilar, or too few data are available to define the relationship between acute toxicity and the water quality characteristic, then the LMAATC must be calculated using the procedures in Section 302.555.

 

c)         Normalize the TAT values for each species, by subtracting W, the arithmetic mean of the TAT values of a species, from each of the TAT values used in the determination of the mean, such that the arithmetic mean of the normalized TAT values for each species individually or for any combination of species is zero (0.0).

 

d)         Normalize the TWQC values for each species using X, the arithmetic mean of the TWQC values of a species, in the same manner as in subsection (c).

 

e)         Group all the normalized data by treating them as if they were from a single species and perform a least squares linear regression of all the normalized TAT values on the corresponding normalized TWQC values to obtain the pooled acute slope, V.

 

f)         For each species, the graphical intercept representing the species TAT intercept, f(Y), at a specific selected value, Z, of the WQC is calculated using the equation:

 

f(Y) = W - V(X – g(Z))

 

Where:

 

f()	is the transformation used to convert acute toxicity values to TAT values
Y	is the species acute toxicity intercept or species acute intercept
W	is the arithmetic mean of the TAT values as specified in subsection (c)
V	is the pooled acute slope as specified in subsection (e)
X	is the arithmetic mean of the TWQC values as specified in subsection (c)
g()	is the transformation used to convert the WQC values to TWQC values
Z	is a selected value of the WQC

 

g)         For each species, determine the species acute intercept, Y, by carrying out an inverse transformation of the species TAT value, f(Y).  For example, in the case of a logarithmic transformation, Y = antilogarithm of (f(Y)); or in the case where no transformation is used, Y = f(Y).

 

h)         The Final Acute Intercept (FAI) is derived by using the species acute intercepts, obtained from subsection (f), in compliance with the procedures described in Section 302.555(b) through (g), with the word "value" replaced by the word "intercept".  Note that in this procedure, geometric means and natural logarithms are always used.

 

i)          The Aquatic Acute Intercept (AAI) is obtained by dividing the FAI by two.  If, for a commercially or recreationally important species, the geometric mean of the acute values at Z is lower than the FAV at Z, then the geometric mean of that species must be used as the FAV.

 

j)          The LMAATC at any value of the WQC, denoted by WQCx, is calculated using the terms defined in subsection (f) and the equation:

 

LMAATC = exp[V(g(WQCx) – g(Z)) + f(AAI)]

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.563  Determining the Tier II Lake Michigan Basin Acute Aquatic Life Toxicity Value (LMAATV)

 

If all eight minimum data requirements for calculating a FAV using Tier I procedures are not met, a Tier II LMAATV must be calculated for a substance as follows:

 

a)         The lowest GMAV in the database is divided by the Secondary Acute Factor (SAF) corresponding to the number of satisfied minimum data requirements listed in the Tier I methodology (Section 302.553).  To calculate a Tier II LMAATV, the database must contain, at a minimum, a GMAV for one of the following three genera in the family Daphnidae – Ceriodaphnia sp., Daphnia sp., or Simocephalus sp.  The Secondary Acute Factors are:

 

Number of Minimum data requirements satisfied (required taxa)	Secondary Acute Factor
1	43.8
2	26.0
3	16.0
4	14.0
5	12.2
6	10.4
7	8.6

 

b)         If dependent on a water quality characteristic, the Tier II LMAATV must be calculated according to Section 302.560.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.565  Determining the Lake Michigan Basin Chronic Aquatic Life Toxicity Criterion (LMCATC) or the Lake Michigan Basin Chronic Aquatic Life Toxicity Value (LMCATV)

 

a)         Determining Tier I LMCATC

 

1)         When chronic toxicity data are available for at least eight resident or indigenous species from eight different North American genera of freshwater organisms as specified in Section 302.553, a Tier I LMCATC is derived in the same manner as the FAV in Section 302.555 or 302.560 by substituting LMCATC for FAV or FAI, chronic for acute, SMCV (Species Mean Chronic Value) for SMAV, and GMCV (Genus Mean Chronic Value) for GMAV.

 

2)         If data are not available to meet the requirements of subsection (a), a Tier I LMCATC is calculated by dividing the FAV by the geometric mean of the acute-chronic ratios (ACRs) obtained from at least one species of aquatic animal from at least three different families provided that of the three species:

 

A)        At least one is a fish;

 

B)        At least one is an invertebrate; and

 

C)        At least one species is an acutely sensitive freshwater species if the other two are saltwater species.

 

3)         The acute-chronic ratio (ACR) for a species equals the acute toxicity concentration from data considered under Section 302.555 or 302.560, divided by the chronic toxicity concentration.

 

4)         If a resident or indigenous species whose presence is necessary to sustain commercial or recreational activities will not be protected by the calculated LMCATC, then the SMCV for that species is used as the CATC.

 

b)         Determining the Tier II LMCATV

 

1)         If all eight minimum data requirements for calculating an FCV using Tier I procedures are not met, or if there are not enough data for all three ACRs, a Tier II Lake Michigan Chronic Aquatic Life Toxicity Value must be calculated using a secondary acute chronic ratio (SACR) determined as follows:

 

A)        If fewer than three valid experimentally determined ACRs are available:

 

i)          Use sufficient ACRs of 18 so that the total number of ACRs equals three; and

 

ii)         Calculate the Secondary Acute-Chronic Ratio as the geometric mean of the three ACRs; or

 

B)        If no experimentally determined ACRs are available, the SACR is 18.

 

2)         Calculate the Tier II LMCATV using one of the following equations:

 

A)        Tier II LMCATV = FAV / SACR

 

B)        Tier II LMCATV = SAV / FACR

 

C)        Tier II LMCATV = SAV / SACR

 

Where:

 

the SAV equals 2 times the value of the Tier II LMAATV calculated in Section 302.563.

 

3)         If, for a commercially or recreationally important species, the SMCV is lower than the calculated Tier II LMCATV, then the SMCV must be used as the Tier II LMCATV.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.570  Procedures for Deriving Bioaccumulation Factors for the Lake Michigan Basin

 

A bioaccumulation factor (BAF) is used to relate the concentration of a substance in an aquatic organism to the concentration of the substance in the waters in which the organism resides when all routes of exposure (ambient water and food) are included.  A BAF is used in the derivation of water quality criteria to protect wildlife and criteria and values to protect human health.

 

a)         Selection of Data.  BAFs can be obtained or developed from one of the following methods, listed in order of preference.

 

1)         Field-measured BAF.

 

2)         Field-measured biota-sediment accumulation factor (BSAF).

 

3)         Laboratory-measured bioconcentration factor (BCF).

The concentration of particulate organic carbon (POC) and dissolved organic carbon (DOC) in the test solution must be either measured or reliably estimated.

 

4)         Predicted BCF.

 

Predicted baseline BCF = Kow.

 

b)         Calculation of Baseline BAFs for Organic Chemicals

The most preferred BAF or BCF from above is used to calculate a baseline BAF which in turn is utilized to derive a human health or wildlife specific BAF.

 

1)         Procedures for Determining the Necessary Elements of Baseline Calculation

 

A)        Lipid Normalization. The lipid-normalized concentration, C₁, of a chemical in tissue is defined using the following equation:

 

C₁ = C_b / f₁

 

Where:

 

Cb	=	concentration of the organic chemical in the tissue of aquatic biota (either whole organism or specified tissue) (μg/g)
f1	=	fraction of the tissue that is lipid

 

B)        Bioavailability.

The fraction of the total chemical in the ambient water that is freely dissolved, f_fd, must be calculated using the following equation:

 

f_fd = 1 /  {1 + [(DOC)(Kow)/10] + [(POC)(Kow)]} 

 

Where:

 

DOC	=	concentration of dissolved organic carbon, kg of dissolved organic carbon/L of water
Kow	=	octanol-water partition coefficient of the chemical
POC	=	concentration of particulate organic carbon, kg of particulate organic carbon/L of water

 

C)        Food Chain Multiplier (FCM).  For an organic chemical, the FCM used must be taken from Table B-1 in Appendix B of 40 CFR 132, incorporated by reference at 35 Ill. Adm. Code 301.106.

 

2)         Calculation of Baseline BAFs

 

A)        From Field-Measured BAFs

 

Baseline BAF = { [measured BAF_tT / f_fd] – 1 }{ 1 / f₁ } 

 

Where:

 

BAFtT	=	BAF based on total concentration in tissue and water of study organism and site
f1	=	fraction of the tissue of study organism that is lipid
ffd	=	fraction of the total chemical that is freely dissolved in the ambient water

 

B)        From a Field-Measured Biota-Sediment Accumulation Factor (BSAF)

 

(Baseline BAF)_i = (baseline BAF)_r (BSAF)_i (Kow)_i /

(BSAF)_r (Kow)_r

 

Where:

 

(BSAF)i	=	BSAF for chemical "i"
(BSAF)r	=	BSAF for the reference chemical "r"
(KOW)i	=	octanol-water partition coefficient for chemical "i"
(KOW)r	=	octanol-water partition coefficient for the reference chemical "r"

 

i)          A BSAF must be calculated using the following equation:

 

BSAF = C₁ / C_soc

 

Where:

 

C1	=	the lipid-normalized concentration of the chemical in tissue
Csoc	=	the organic carbon-normalized concentration of the chemical in sediment

 

ii)         The organic carbon-normalized concentration of a chemical in sediment, C_soc, must be calculated using the following equation:

 

C_soc = C_s / f_oc

 

Where:

 

Cs	=	concentration of chemical in sediment (μg/g sediment)
foc	=	fraction of the sediment that is organic carbon

 

C)        From a Laboratory-Measured BCF

 

baseline BAF = (FCM) { [measured BCF_tT / f_fd ] - 1 } { 1 /f₁ }

 

Where:

 

BCFtT	=	BCF based on total concentration in tissue and water.
f1	=	fraction of the tissue that is lipid
ffd	=	fraction of the total chemical in the test water that is freely dissolved
FCM	=	the food-chain multiplier obtained from Table B-1 in Appendix B to 40 CFR 132,, incorporated by reference at 35 Ill. Adm. Code 301.106, by linear interpolation for trophic level 3 or 4, as necessary

 

D)        From a Predicted BCF

 

baseline BAF = (FCM) (predicted baseline BCF) = (FCM)(Kow)

 

Where:

 

FCM	=	the food-chain multiplier obtained from Table B-1 in Appendix B to 40 CFR 132, incorporated by reference at 35 Ill. Adm. Code 301.106, by linear interpolation for trophic level 3 or 4, as necessary
Kow	=	octanol-water partition coefficient

 

c)         Human Health and Wildlife BAFs for Organic Chemicals

 

1)         Fraction freely dissolved (f_fd).  By using the equation in subsection (b)(1)(B), the f_fd to be used to calculate human health and wildlife BAFs for an organic chemical must be calculated using a standard POC concentration of 0.00000004 kg/L and a standard DOC concentration of 0.000002 kg/L:

 

f_fd  = 1 / [1+ (0.00000024 kg/L)(Kow)]

 

2)         Human health BAF.  The human health BAFs for an organic chemical must be calculated using the following equations:

 

A)        For Trophic Level 3

 

Human Health BAF_HHTL3 = [(baseline BAF)(0.0182) + 1] (f_fd)

 

B)        For Trophic Level 4

 

Human Health BAF_HHTL4 = [(baseline BAF) (0.0310) + 1] (f_fd)

 

Where:

 

0.0182 and 0.0310 are the standardized fraction lipid values for trophic levels 3 and 4, respectively, that are used to derive human health criteria and values

 

3)         Wildlife BAF.  The wildlife BAFs for an organic chemical must be calculated using the following equations:

 

A)        For Trophic Level 3

 

Wildlife BAF_WLTL3 = [(baseline BAF)(0.0646) +1] (f_fd)

 

B)        For Trophic Level 4

 

Wildlife BAF_WLTL4 = [(baseline BAF)(0.1031) + 1] (f_fd)

 

Where:

 

0.0646 and 0.1031 are the standardized fraction lipid values for trophic levels 3 and 4, respectively, that are used to derive wildlife criteria

 

d)         Human Health and Wildlife BAFs for Inorganic Chemicals.  For inorganic chemicals, the baseline BAFs for trophic levels 3 and 4 are both assumed to equal the BCF determined for the chemical with fish.

 

1)         Human Health.  Measured BAFs and BCFs used to determine human health BAFs for inorganic chemicals must be based on concentration in edible tissue (e.g., muscle) of freshwater fish.

 

2)         Wildlife.  Measured BAFs and BCFs used to determine wildlife BAFs for inorganic chemicals must be based on concentration in the whole body of freshwater fish and invertebrates.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.575  Procedures for Deriving Tier I Water Quality Criteria and Values in the Lake Michigan Basin to Protect Wildlife

 

The Lake Michigan Basin Wildlife Criterion (LMWC) is the concentration of a substance that, if not exceeded, protects Illinois wild mammal and bird populations from adverse effects resulting from the ingestion of surface waters of the Lake Michigan Basin or aquatic prey organisms taken from surface waters of the Lake Michigan Basin.  Wildlife criteria calculated under this Section protect against long-term effects and are therefore considered chronic criteria.  The methodology involves the use of data from test animals to derive criteria to protect representative or target species:  bald eagle, herring gull, belted kingfisher, mink, and river otter.  The lower of the geometric mean of species-specific criteria for bird species or mammal species is chosen as the LMWC to protect a broad range of species.

 

a)         This method must also be used for non-BCCs when appropriately modified to consider the following factors:

 

1)         Selection of scientifically justified target species;

 

2)         Relevant routes of chemical exposure;

 

3)         Pertinent toxicity endpoints.

 

b)         Minimum Data Requirements

 

1)         Test Dose (TD).  To calculate an LMWC, the following minimal database is required:

 

A)        There must be at least one data set showing dose-response for oral, subchronic, or chronic exposure of 28 days for one bird species; and

 

B)        There must be at least one data set showing dose-response for oral, subchronic, or chronic exposure of 90 days for one mammal species.

 

2)         Bioaccumulation Factor (BAF) Data Requirements

 

A)        For any chemical with a BAF of less than 125, the BAF may be obtained by any method; and

 

B)        For chemicals with a BAF of greater than 125, the BAF must come from a field measured BAF or Biota-Sediment Accumulation Factor (BSAF).

 

c)         Principles for Developing Criteria

 

1)         Dose Standardization.  The data for the test species must be expressed as, or converted to, the form mg/kg/d utilizing the guidelines for drinking and feeding rates and other procedures in 40 CFR 132, incorporated by reference in 35 Ill. Adm. Code 301.106.

 

2)         Uncertainty factors (UF) for utilizing test dose data in the calculation of the target species value (TSV);

 

A)        Correction for Intermittent Exposure.  If the animals used in a study were not exposed to the toxicant each day of the test period, the no observed adverse effect level (NOAEL) must be multiplied by the ratio of days of exposure to the total days in the test period.

 

B)        Correction from the Lowest Observed Adverse Effect Level (LOAEL) to NOAEL (UF₁).  For those substances for which a LOAEL has been derived, the UF₁ must not be less than one and should not exceed 10.

 

C)        Correction for Subchronic to Chronic Extrapolation (UF_s).  In instances where only subchronic data are available, the TD may be derived from subchronic data.  The value of the UF_s must not be less than one and should not exceed 10.

 

D)        Correction for Interspecies Extrapolations (UF_a).  For the derivation of criteria, a UF_a must not be less than one and should not exceed 100.  The UF_a must be used only for extrapolating toxicity data across species within a taxonomic class.  A species-specific UF_a must be selected and applied to each target species, consistent with the equation in subsection (d).

 

d)         Calculation of TSV.  The TSV, measured in milligrams per liter (mg/L), is calculated according to the equation:

 

TSV = {[TD x Wt] / [UF_a x UF_s x UF₁]}   /   {W + Σ[F_TLi x BAF_WLTLi]}

 

Where:
	TSV	=	target species value in milligrams of substance per liter (mg/L).
	TD	=	test dose that is toxic to the test species, either NOAEL or LOAEL.
	UFa	=	the uncertainty factor for extrapolating toxicity data across species (unitless).  A species-specific UFa must be selected and applied to each target species, consistent with the equation.
	Ufs	=	the uncertainty factor for extrapolating from subchronic to chronic exposures (unitless).
	Uf1	=	the uncertainty factor for extrapolation from LOAEL to NOAEL (unitless).
	Wt	=	average weight in kilograms (kg) of the target species.
	W	=	average daily volume of water in liters consumed per day (L/d) by the target species.
	FTLi	=	average daily amount of food consumed by the target species in kilograms (kg/d) for trophic level i.
	BAFWLTLi	=	aquatic life bioaccumulation factor with units of liter per kilogram (L/kg), as derived from 35 Ill. Adm. Code 302.570 for trophic level i.

 

e)                  Calculation of the Lake Michigan Basin Wildlife Criterion.  TSVs are obtained for each target species.  The geometric mean of the TSVs is calculated for all mammal species and all bird species.  The LMWC is the lower of the bird or mammal geometric mean TSV.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.580  Procedures for Deriving Water Quality Criteria and Values in the Lake Michigan Basin to Protect Human Health - General  

 

a)         The Lake Michigan Basin human health criteria or values for a substance are those concentrations at which humans are protected from adverse effects resulting from incidental exposure to, or ingestion of, the waters of Lake Michigan and from ingestion of aquatic organisms taken from the waters of Lake Michigan.  A Lake Michigan Human Health Threshold Criterion (LMHHTC) or Lake Michigan Human Health Threshold Value (LMHHTV) will be calculated for all substances according to Section 302.585, if data is available.  Water quality criteria or values for substances that are, or may be, carcinogenic to humans will also be calculated according to procedures for the Lake Michigan Human Health Nonthreshold Criterion (LMHHNC) or the Lake Michigan Human Health Nonthreshold Value (LMHHNV) in Section 302.590.

 

b)         Minimum data requirements for BAFs for Lake Michigan Basin human health criteria:

 

1)         Tier I

 

A)        For all organic chemicals, either a field-measured BAF or a BAF derived using the BSAF methodology is required unless the chemical has a BAF less than 125, then a BAF derived by any methodology is required; and

 

B)        For all inorganic chemicals, including organometals such as mercury, either a field-measured BAF or a laboratory-measured BCF is required.

 

2)         Tier II. Any bioaccumulation factor method in Section 302.570(a) may be used to derive a Tier II criterion.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.585  Procedures for Determining the Lake Michigan Basin Human Health Threshold Criterion (LMHHTC) and the Lake Michigan Basin Human Health Threshold Value (LMHHTV)

 

The LMHHTC or LMHHTV is derived for all toxic substances from the most sensitive endpoint for which there exists a dosage or concentration below which no adverse effect or response is likely to occur.

 

a)         Minimum Data Requirements

 

1)         Tier I.  The minimum data set sufficient to derive a Tier I LMHHTC must include at least one epidemiological study or one animal study of greater than 90 days duration; or

 

2)         Tier II.  When the minimum data for deriving Tier I criteria are not available, a more limited database consisting of an animal study of greater than 28 days duration must be used.

 

b)         Principles for Development of Tier I Criteria and Tier II Values

 

1)         The experimental exposure level representing the highest level tested at which no adverse effects were demonstrated (NOAEL) must be used to calculate a criterion or value.  In the absence of a NOAEL, a LOAEL must be used if it is based on relatively mild and reversible effects;

 

2)         Uncertainty factors (UFs) must be used to account for the uncertainties in predicting acceptable dose levels for the general human population based upon experimental animal data or limited human data:

 

A)        A UF of 10 must be used when extrapolating from experimental results of studies on prolonged exposure to average healthy humans;

 

B)        A UF of 100 must be used when extrapolating from results of long-term studies on experimental animals;

 

C)        A UF of up to 1000 must be used when extrapolating from animal studies for which the exposure duration is less than chronic, but greater than subchronic;

 

D)        A UF of up to 3000 must be used when extrapolating from animal studies for which the exposure duration is less than subchronic;

 

E)        An additional UF of between one and ten must be used when deriving a criterion from a LOAEL.  The level of additional uncertainty applied will depend upon the severity and the incidence of the observed adverse effect;

 

F)         An additional UF of between one and ten must be applied when there are limited effects data or incomplete sub-acute or chronic toxicity data;

 

3)         The total uncertainty (∑ of the uncertainty factors) must not exceed 10,000 for Tier I criterion and 30,000 for Tier II value; and

 

4)         All study results must be converted to the standard unit for acceptable daily exposure of milligrams of toxicant per kilogram of body weight per day (mg/kg/day).  Doses must be adjusted for continuous exposure.

 

c)         Tier I Criteria and Tier II Value Derivation

 

1)         Determining the Acceptable Daily Exposure (ADE)

 

ADE = test value / ∑ of the UFs from subsection (b)(2)

 

Where:

 

acceptable daily exposure is in milligrams toxicant per kilogram body weight per day (mg/kg/day)

 

2)         Determining the Lake Michigan Basin Human Health Threshold Criterion (LMHHTC) or the Lake Michigan Basin Human Health Threshold Value (LMHHTV)

 

LMHHTC or LMHHTV =

 

{ADE x BW x RSC } / 

 

{WC + [(FC_TL3 x BAF_HHTL3) + (FC_TL4 x BAF_HHTL4)]} 

 

Where:

 

LMHHTC or LMHHTV is in milligrams per liter (mg/L)
ADE	=	acceptable daily intake in milligrams toxicant per kilogram body weight per day (mg/kg/day)
RSC	=	relative source contribution factor of 0.8
BW	=	weight of an average human (BW = 70 kg)
WC	=	per capita water consumption (both drinking and incidental exposure) for surface waters classified as public water supplies = two liters/day; or per capita incidental daily water ingestion for surface waters not used as human drinking water sources = 0.01 liters/day
FCTL3	=	mean consumption of trophic level 3 fish by regional sport fishers of regionally caught freshwater fish = 0.0036 kg/day
FCTL4	=	mean consumption of trophic level 4 fish by regional sport fishers of regionally caught freshwater fish = 0.0114 kg/day
BAFHHTL3	=	human health bioaccumulation factor for edible portion of trophic level 3 fish, as derived using the BAF methodology in Section 302.570
BAFHHTL4	=	human health bioaccumulation factor for edible portion of trophic level 4 fish, as derived using the BAF methodology in Section 302.570

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.590  Procedures for Determining the Lake Michigan Basin Human Health Nonthreshold Criterion (LMHHNC) or the Lake Michigan Basin Human Health Nonthreshold Value (LMHHNV)

 

An LMHHNC or LMHHNV must be derived for those toxic substances for which any exposure, regardless of extent, carries some risk of damage from cancer or a nonthreshold toxic mechanism.  For single or combinations of substances, a risk level of 1 in 100,000 (or 10^-5) must be used to determine an LMHHNC or LMHHNV.

 

a)         Minimum Data Requirements.  Minimal experimental or epidemiological data requirements are incorporated in the cancer classification determined by USEPA in Appendix C II A to 40 CFR 132, incorporated by reference at 35 Ill. Adm. Code 301.106.

 

b)         Principles for Development of Criteria or Values

 

1)         Animal data are fitted to a linearized multistage computer model (Global 1986 in "Mutagenicity and Carcinogenicity Assessment for 1, 3-Butadiene" September 1985 EPA/600/8-85/004A, incorporated by reference at 35 Ill. Adm. Code 301.106 or scientifically justified equivalents).  The upper-bound 95 percent confidence limit on risk at the 1 in 100,000 risk level must be used to calculate a risk associated dose (RAD); and

 

2)         A species scaling factor must be used to account for differences between test species and humans.  Milligrams per surface area per day is an equivalent dose between species.  All doses presented in mg/kg body weight will be converted to an equivalent surface area dose by raising the mg/kg dose to the 3/4 power.

 

c)         Determining the Risk-Associated Dose (RAD).  The RAD must be calculated using the following equation:

 

RAD = 0.00001 / q₁*

 

Where:

 

RAD	=	risk-associated dose in milligrams of toxicant or combinations of toxicants per kilogram body weight per day (mg/kg/day)
0.00001 (1 X 10-5)	=	incremental risk of developing cancer equal to 1 in 100,000
q1*	=	slope factor (mg/kg/day)-1
RAD	=	risk-associated dose in milligrams of toxicant or combinations of toxicants per kilogram body weight per day (mg/kg/day)
0.00001 (1 X 10(-5))	=	incremental risk of developing cancer equal to 1 in 100,000
q1*	=	slope factor (mg/kg/day)-1

 

d)         Determining the Lake Michigan Basin Human Health Nonthreshold Criterion (LMHHNC) or the Lake Michigan Basin Human Health Nonthreshold Value (LMHHNV)

 

LMHHNC or LMHHNV =

 

{ RAD x BW } / { WC + [(FC_TL3 x BAF_HHTL3) + (FC_TL4 x BAF_HHTL4)] }

 

Where:

 

LMHHNC or LMHHNV is in milligrams per liter (mg/L)
RAD	=	risk-associated dose of a substance or combination of substances in milligrams per day (mg/d) which is associated with a lifetime cancer risk level equal to a ratio of 1 to 100,000
BW	=	weight of an average human (BW = 70 kg)
WC	=	per capita water consumption for surface waters classified as public water supplies = two liters/day, or per capita incidental daily water ingestion for surface waters not used as human drinking water sources = 0.01 liters/day
FCTL3	=	mean consumption of trophic level 3 of regionally caught freshwater fish = 0.0036 kg/day
FCTL4	=	mean consumption of trophic level 4 of regionally caught freshwater fish = 0.0114 kg/day
BAFHHTL3, BAFHHTL4	=	bioaccumulation factor for trophic levels 3 and 4 as derived in Section 302.570

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.595  Listing of Bioaccumulative Chemicals of Concern, Derived Criteria and Values

 

a)         The Agency must maintain a listing of toxicity criteria and values derived under this Subpart.  This list must be made available to the public and updated whenever a new criterion or value is derived and must be published when updated in the Illinois Register.

 

b)         A criterion or value published under subsection (a) may be proposed to the Board for adoption as a numeric water quality standard.

 

c)         The Agency must maintain for inspection all information, including assumptions, toxicity data, and calculations, used in the derivation of any toxicity criterion or value listed pursuant to subsection (a) until adopted by the Board as a numeric water quality standard.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.601  Scope and Applicability

 

This Subpart contains the procedures for determining the water quality criteria in Sections 302.210(a), (b), and (c) and 302.410(a), (b), and (c).

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.603  Definitions

 

As used in this Subpart, the following terms have the meanings specified.

 

"Bioconcentration" means an increase in the concentration of a chemical and its metabolites in an organism (or its specified tissues) relative to the concentration of the chemical in the ambient water acquired through contact with the water alone.

 

"Carcinogen" means a chemical that causes an increased incidence of benign or malignant neoplasms, or a statistically significant decrease in the latency period between exposure and onset of neoplasms, in at least one mammalian species or man through epidemiological or clinical studies.

 

"EC-50" means the concentration of a substance or effluent that causes a given effect to 50% of the exposed organisms in a given time period.

 

"LC-50" means the concentration of a toxic substance or effluent that is lethal to 50% of the exposed organisms in a given time period.

 

"LOAEL" or "Lowest Observable Adverse Effect Level" means the lowest tested concentration of a chemical or substance that produces a statistically significant increase in frequency or severity of non-overt adverse effects between the exposed population and its appropriate control.

 

"MATC" or "Maximum Acceptable Toxicant Concentration" means the value obtained by calculating the geometric mean of the lower and upper chronic limits from a chronic test.  A lower chronic limit is the highest tested concentration that did not cause a specified adverse effect.  An upper chronic limit is the lowest tested concentration that did cause a specified adverse effect and above which all tested concentrations caused a specified adverse effect.

 

"NOAEL" or "No Observable Adverse Effect Level" means the highest tested concentration of a chemical or substance which does not produce a statistically significant increase in frequency or severity of non-overt adverse effects between the exposed population and its appropriate control.

 

"Resident or Indigenous Species" means species that currently live a substantial portion of their lifecycle or reproduce in a given body of water or that are native species whose historical range includes a given body of water.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.604  Mathematical Abbreviations

 

This Subpart uses the following mathematical abbreviations:

 

exp x	base of the natural logarithm, e, raised to x-power
ln x	natural logarithm of x
log x	logarithm to the base 10 of x
A**B	A raised to the B-power
SUM(x)	summation of the values of x

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.606  Data Requirements

 

The Agency must review, for validity, applicability, and completeness, data used in calculating criteria.  To the extent available and not otherwise specified, testing procedures, selection of test species and other aspects of data acquisition must be according to methods published by USEPA or nationally recognized standards organizations, including methods found in "Standard Methods", incorporated by reference in 35 Ill. Adm. Code 301.106.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.612  Determining the Acute Aquatic Toxicity Criterion for an Individual Substance - General Procedures

 

a)         A chemical-specific Acute Aquatic Toxicity Criterion (AATC) is calculated using procedures specified in Sections 302.615 and 302.618 if acute toxicity data are available for at least five resident or indigenous species from five different North American genera of freshwater organisms, including representatives of the following taxa:

 

1)         Representatives of two families in the Class Osteichthyes (Bony Fish).

 

2)         The family Daphnidae.

 

3)         A benthic aquatic macroinvertebrate.

 

4)         A vascular aquatic plant or a third family in the Phylum Chordata that may be from the Class Osteichthyes.

 

b)         If data are not available for resident or indigenous species, data for non-resident species may be used if the non-resident species is of the same family or genus and has a similar habitat and environmental tolerance. The procedures of Section 302.615 must be used to obtain an AATC for individual substances whose toxicity is unaffected by ambient water quality characteristics.  The procedures of Section 302.618 must be used if the toxicity of a substance is dependent upon some other water quality characteristic.

 

c)         If data are not available that meet the requirements of subsection (a), an AATC is calculated by obtaining at least one EC-50 or LC-50 value from both a daphnid species and either fathead minnow or bluegill.  If there are data available for any other North American freshwater species, they must also be included.  An AATC is calculated by dividing the lowest Species Mean Acute Value (SMAV), as determined according to Section 302.615, by 10.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.615  Determining the Acute Aquatic Toxicity Criterion – Toxicity Independent of Water Chemistry

 

If the acute toxicity of the chemical has not been shown to be related to a water quality characteristic, including hardness, pH, or temperature, the AATC is calculated by using the procedures below.

 

a)         For each species for which more than one acute value is available, the Species Mean Acute Value (SMAV) is calculated as the geometric mean of the acute values from all tests.

 

b)         For each genus for which one or more SMAVs are available, the Genus Mean Acute Value (GMAV) is calculated as the geometric mean of the SMAVs available for the genus.

 

c)         The GMAVs are ordered from high to low.

 

d)         Ranks (R) are assigned to the GMAVs from "1" for the lowest to "N" for the highest.  If two or more GMAVs are identical, successive ranks are arbitrarily assigned.

 

e)         The cumulative probability, P, is calculated for each GMAV as R/(N + 1).

 

f)         The GMAVs to be used in the calculations of subsection (g) must be those with cumulative probabilities closest to 0.05.  If there are less than 59 GMAVs in the total data set, the values utilized must be the lowest obtained through the ranking procedures of subsections (c) and (d).  "T" is the number of GMAVs that are to be used in the calculations of subsection (g).  T is equal to 4 when the data set includes at least one representative from each of the five taxa in Section 302.612 and a representative from each of the three taxa listed below.  T is equal to 3 when the data includes at least one representative from each of the five taxa in Section 302.612 and one or two of the taxa listed below.  T is equal to 2 when the data set meets the minimum requirements of Section 302.612 but does not include representatives from any of the three taxa listed below.  When toxicity data on any of the three taxa listed below are available, they must be used along with the minimum data required pursuant to Section 302.612.

 

1)         A benthic crustacean, unless one was used under Section 302.612(a)(3), in which case an insect must be used.

 

2)         A member of a phylum not used in subsection (a), (b), or (f)(1).

 

3)         An insect from an order not already represented.

 

g)         Using the GMAVs and T-value identified under subsection (f) and the Ps calculated under subsection (e), the Final Acute Value (FAV) and the AATC are calculated as:

 

FAV	=	exp(A) and
AATC	=	FAV/2

 

Where:

 

A	=	L + 0.2236 S;
L	=	[SUM(1n GMAV) - S(SUM(P**0.5))]/T; and
S	=	[[SUM((1n GMAV)**2) - ((SUM(1n GMAV))**2)/T]/[SUM(P) - ((SUM(P**0.5))**2)/T]]**0.5

 

h)         If a resident or indigenous species whose presence is necessary to sustain commercial or recreational activities or prevent disruptions of the waterbody's ecosystem, including loss of species diversity or a shift to a biotic community dominated by pollution-tolerant species, will not be protected by the calculated FAV, then the EC-50 or LC-50 for that species is used as the FAV.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.618  Determining the Acute Aquatic Toxicity Criterion - Toxicity Dependent on Water Chemistry

 

If data are available to show that a relationship exists between a water quality characteristic (WQC) and acute toxicity to two or more species, an Acute Aquatic Toxicity Criterion (AATC) may be calculated.  The best-documented relationship is between the water quality characteristic, hardness, and acute toxicity of metals. Although this relationship between hardness and acute toxicity is typically non-linear, it can be linearized by a logarithmic transformation (i.e., for any variable, K, f(K) = logarithm of K) of the variables and plotting the logarithm of hardness against the logarithm of acute toxicity.  Similarly, relationships between acute toxicity and other water quality characteristics, such as pH or temperature, may require a transformation, including no transformation (i.e., for any variable, K, f(K) = K), for one or both variables to obtain a least squares linear regression of the transformed acute toxicity values on the transformed values of the water quality characteristic.  An AATC is calculated using the following procedures:

 

a)         For each species for which acute toxicity values are available at two or more different values of the water quality characteristic, a least squares linear regression of the transformed acute toxicity (TAT) values on the transformed water quality characteristic (TWQC) values is performed to obtain the slope of the line describing the relationship.

 

b)         Each of the slopes determined pursuant to subsection (a) is evaluated as to whether or not it is statistically valid, taking into account the range and number of tested values of the water quality characteristic and the degree of agreement within and between species.  If slopes are not available for at least one fish and one invertebrate species, if the available slopes are too dissimilar, or if too few data are available to define the relationship between acute toxicity and the water quality characteristic, then the AATC must be calculated using the procedures in Section 302.615.

 

c)         Normalize the TAT values for each species, by subtracting W, the arithmetic mean of the TAT values of a species from each of the TAT values used in the determination of the mean, such that the arithmetic mean of the normalized TAT values for each species individually or for any combination of species is zero (0.0).

 

d)         Normalize the TWQC values for each species using X, the arithmetic mean of the TWQC values of a species, in the same manner as in subsection (c).

 

e)         Group all the normalized data by treating them as if they were from a single species and perform at least squares linear regression of all the normalized TAT values on the corresponding normalized TWQC values to obtain the pooled acute slope, V.

 

f)         For each species, the graphical intercept representing the species TAT intercept, f(Y), at a specific selected value, Z, of the WQC is calculated using the equation:

 

f(Y) = W - V( X -  g(Z))

 

Where:

 

f() is the transformation used to convert acute toxicity values to TAT values;

 

Y is the species acute toxicity intercept or species acute intercept;

 

W is the arithmetic mean of the TAT values as specified in subsection (c);

 

V is the pooled acute slope as specified in subsection (e);

 

X is the arithmetic mean of the TWQC values as specified in subsection (d);

 

g() is the transformation used to convert the WQC values to TWQC values; and

 

Z is a selected value of the WQC.

 

g)         For each species, determine the species acute intercept, Y, by carrying out an inverse transformation of the species TAT value, f(Y).  For example, in the case of a logarithmic transformation, Y = antilogarithm of (f(Y)); or in the case where no transformation is used, Y = f(Y).

 

h)         The Final Acute Intercept (FAI) is derived by using the species acute intercepts, obtained from subsection (g), in compliance with the procedures described in Section 302.615(b) through (g), with the word "value" replaced by the word "intercept".  Note that in this procedure, geometric means and natural logarithms are always used.

 

i)          The Aquatic Acute Intercept (AAI) is obtained by dividing the FAI by two.

 

j)          The AATC at any value of the WQC, denoted by WQCx, is calculated using the terms defined in subsection (f) and the equation:  

 

AATC = exp[V (g(WQCx) - g(Z)) + f (AAI)].

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.621  Determining the Acute Aquatic Toxicity Criterion - Procedure for Combinations of Substances

 

An AATC for any combination of substances (including effluent mixtures) must be determined by the following toxicity testing procedures:

 

a)         Not more than 50% of test organisms from the most sensitive species tested may exhibit mortality or immobility after a 48-hour test for invertebrates or a 96-hour test for fish.

 

b)         Three resident or indigenous species of ecologically diverse taxa must be tested initially.  If resident or indigenous species are not available for testing, non-resident species may be used if the non-resident species is of the same family or genus and has a similar habitat and environmental tolerance.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.627  Determining the Chronic Aquatic Toxicity Criterion for an Individual Substance - General Procedures

 

a)         A chemical-specific Chronic Aquatic Toxicity Criterion (CATC) is calculated using procedures specified in subsection (b) when chronic toxicity data are available for at least five species from five different North American genera of freshwater organisms, including representatives from the following taxa:

 

1)         Representatives of two families in the Class Osteichthyes (Bony Fish).

 

2)         The family Daphnidae.

 

3)         A benthic aquatic macroinvertebrate.

 

4)         An alga (96-hour test) or a vascular aquatic plant.

 

b)         A CATC is derived in the same manner as the FAV in Section 302.615 or 302.618 by substituting CATC for FAV or FAI, chronic for acute, MATC for LC-50, SMCV (Species Mean Chronic Value) for SMAV, and GMCV (Genus Mean Chronic Value) for GMAV.

 

c)         If data are not available to meet the requirements of subsection (a), a CATC is calculated by dividing the FAV by the highest acute-chronic ratio obtained from at least one fish and one invertebrate species.  The acute-chronic ratio for a species equals the acute toxicity concentration from data considered under Sections 302.612 through 302.618, divided by the chronic toxicity concentration from data calculated under subsections (a) and (b) subject to the following conditions:

 

1)         If the toxicity of a substance is related to any water quality characteristic (WQC), the acute-chronic ratio must be based on acute and chronic toxicity data obtained from organisms exposed to test water with WQC values that are representative of the WQC values of the waterbody under consideration. Preference under this subsection must be given to data from acute and chronic tests done by the same author or in the same reference to increase the likelihood of comparable test conditions.

 

2)         If the toxicity of a substance is unrelated to water quality parameters, the acute-chronic ratio may be derived from any acute and chronic test on a species regardless of the similarity in values of those water quality parameters.  Preference under this subsection must be given to data from acute and chronic tests done on the same organisms or their descendants.

 

3)         If there is more than one acute-chronic ratio for a species, a geometric mean of the ratio is calculated, corrected for the relationship of toxicity to water quality parameters.

 

4)         If the acute and chronic toxicity data indicate that the acute-chronic ratio varies with changes in water quality parameters, the acute-chronic ratio used over specified values of the water quality parameters must be based on the ratios at water quality parameter values closest to those specified.

 

5)         If acute and chronic toxicity data are unavailable to determine an acute-chronic ratio for at least two North American freshwater species, a ratio of 25 must be used.

 

d)         If a resident or indigenous species whose presence is necessary to sustain commercial or recreational activities, or prevent disruptions of the waterbody's ecosystem, including loss of species diversity or a shift to a biotic community dominated by pollution-tolerant species, will not be protected by the calculated CATC, then the MATC for that species is used as the CATC.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.630  Determining the Chronic Aquatic Toxicity Criterion - Procedure for Combinations of Substances

 

A CATC for any combination of substances (including effluent mixtures) may be determined by toxicity testing procedures pursuant to the following:

 

a)         A combination of substances must not exceed concentrations greater than a NOAEL as determined for the most sensitive of the species tested.

 

b)         Three resident or indigenous species of ecologically diverse taxa must be tested initially.  If resident or indigenous species are not available for testing, non-resident species may be used if the non-resident species is of the same family or genus and has a similar habitat and environmental tolerance.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.633  The Wild and Domestic Animal Protection Criterion

 

The Wild and Domestic Animal Protection Criterion (WDAPC) is the concentration of a substance that, if not exceeded, protects Illinois wild and domestic animals from adverse effects, such as functional impairment or pathological lesions, resulting from ingestion of surface waters of the State or ingestion of aquatic organisms taken from surface waters of the State.

 

a)         For those substances for which a NOAEL has been derived from studies of mammalian or avian species exposed to the substance via oral routes including gavage, the lowest NOAEL among species must be used in calculating the WDAPC.  Additional considerations in selecting NOAEL include:

 

1)         If the NOAEL is given in milligrams of toxicant per liter of water consumed (mg/L), before calculating the WDAPC, the NOAEL must be multiplied by the daily average volume of water consumed by the test animals in liters per day (L/d) and divided by the average weight of the test animals in kilograms (kg).

 

2)         If the NOAEL is given in milligrams of toxicant per kilogram of food consumed (mg/kg), before calculating the WDAPC, the NOAEL must be multiplied by the average amount of food in kilograms consumed daily by the test animals (kg/d) and divided by the average weight of the test animals in kilograms (kg).

 

3)         If the animals used in a study were not exposed to the toxicant each day of the test period, the NOAEL must be multiplied by the ratio of days of exposure to the total days in the test period.

 

4)         If more than one NOAEL is available for the same animal species, the geometric mean of the NOAELs must be used to calculate the WDAPC.

 

b)         For those substances for which a NOAEL is not available but the lowest observed adverse effect level (LOAEL) has been derived from studies of animal species exposed to the substance via oral routes including gavage, one-tenth of the LOAEL must be substituted for the NOAEL.

 

c)         The LOAEL must be selected in the same manner as that specified for the NOAEL in subsection (a).

 

d)         The WDAPC, measured in milligrams per liter (mg/L), is calculated according to the equation:

 

            WDAPC = [0.1 NOAEL x Wt]/[W + (F x BCF)]

 

Where:

 

NOAEL is derived from mammalian or avian studies as specified in subsections (a) and (b), and is measured in units of milligrams of substance per kilogram of body weight per day (mg/kg-d);
Wt	=	Average weight in kilograms (kg) of the test animals;
W	=	Average daily volume of water in liters consumed per day (L/d) by the test animals;
F	=	Average daily amount of food consumed by the test animals in kilograms (kg/d);
BCF	=	Aquatic life Bioconcentration Factor with units of liter per kilogram (L/kg), as derived in Sections 302.660 through 302.666; and
The 0.1 represents an uncertainty factor to account for species variability.

 

e)         If no studies pertaining to the toxic substance in question can be found by the Agency, no criterion can be determined.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.642  The Human Threshold Criterion

 

The Human Threshold Criterion (HTC) of a substance is that concentration or level of a substance at which humans are protected from adverse effects resulting from incidental exposure to, or ingestion of, surface waters of the State and from ingestion of aquatic organisms taken from surface waters of the State. HTCs are derived for those toxic substances for which there exists a threshold dosage or concentration below which no adverse effect or response is likely to occur.

 

(Source:  Added at 14 Ill. Reg. 2899, effective February 13, 1990)

 

Section 302.645  Determining the Acceptable Daily Intake

 

The Acceptable Daily Intake (ADI) is the maximum amount of a substance that, if ingested daily for a lifetime, results in no adverse effects to humans.  Subsections (a) through (e) list, in the order of preference, methods for determining the acceptable daily intake.

 

a)         The lowest of the following ADI values:

 

1)         For substances listed with a maximum contaminant level in 40 CFR 141 (incorporated by reference in 35 Ill. Adm. Code 301.106) or in 35 Ill. Adm. Code 611, the ADI equals the product of multiplying the maximum contaminant level given in milligrams per liter (mg/L) by 2 liters per day (L/d).

 

2)         For substances listed with a maximum allowable concentration standard in 35 Ill. Adm. Code Subtitle F, the acceptable daily intake equals the product of multiplying the public health enforcement standard given in milligrams per liter (mg/L) by 2 liters per day (L/d).

 

b)         For substances for which a no observed adverse effect level (NOAEL-H) for humans exposed to the substance in drinking water has been derived, the acceptable daily intake equals the product of multiplying one-tenth of the NOAEL-H given in milligrams of toxicant per liter of water consumed (mg/L) by 2 liters per day (L/d).  The lowest NOAEL-H must be used in the calculation of the acceptable daily intake.

 

c)         For substances for which the lowest observed adverse effect level (LOAEL-H) for humans exposed to the substance in drinking water has been derived, one-hundredth of the LOAEL-H may be substituted for the NOAEL-H in subsection (b).

 

d)         For substances for which a no observed adverse effect level (NOAEL-A) has been derived from studies of mammalian test species exposed to the substance via oral routes including gavage, the acceptable daily intake equals the product of multiplying 1/100 of the NOAEL-A given in milligrams toxicant per day per kilogram of test species weight (mg/kg-d) by the average weight of an adult human of 70 kilograms (kg).  The lowest NOAEL-A among animal species must be used in the calculation of the acceptable daily intake.  Additional considerations in selecting the NOAEL-A include: 

 

1)         If the NOAEL-A is given in milligrams of toxicant per liter of water consumed (mg/L), before calculating the acceptable daily intake, the NOAEL-A must be multiplied by the daily average volume of water consumed by the mammalian test species in liters per day (L/d) and divided by the average weight of the mammalian test species in kilograms (kg).

 

2)         If the NOAEL-A is given in milligrams of toxicant per kilogram of food consumed (mg/kg), before calculating the acceptable daily intake, the NOAEL-A must be multiplied by the average amount in kilograms of food consumed daily by the mammalian test species (kg/d) and divided by the average weight of the mammalian test species in kilograms (kg).

 

3)         If the mammalian test species were not exposed to the toxicant each day of the test period, the NOAEL-A must be multiplied by the ratio of days of exposure to the total days of the test period.

 

4)         If more than one NOAEL-A is available for the same mammalian test species, the geometric mean of the NOAEL-As must be used.

 

e)         For substances for which a NOAEL-A is not available but the lowest observed adverse effect level (LOAEL-A) has been derived from studies of mammalian test species exposed to the substance via oral routes including gavage, one-tenth of the LOAEL-A may be substituted for the NOAEL-A in subsection (d).  The LOAEL-A must be selected in the same manner as that specified for the NOAEL-A in subsection (d).

 

f)         If no studies pertaining to the toxic substance in question can be found by the Agency, no criterion can be determined.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.648  Determining the Human Threshold Criterion

 

The HTC is calculated according to the equation:

 

HTC = ADI/[W + (F x BCF)]

 

            where:

 

HTC	=	Human health protection criterion in milligrams per liter (mg/L);
ADI	=	Acceptable daily intake of substance in milligrams per day (mg/d) as specified in Section 302.645;
W	=	Per capita daily water consumption equal to 2 liters per day (L/d) for surface waters at the point of intake of a public or food processing water supply, or equal to 0.01 liters per day (L/d) which represents incidental exposure through contact or ingestion of small volumes of water while swimming or during other recreational activities for areas that are determined to be public access areas under Section 302.102(b)(3), or 0.001 liters per day (L/d) for other waters;
F	=	Assumed daily fish consumption in the United States equal to 0.020 kilograms per day (kg/d); and
BCF	=	Aquatic organism Bioconcentration Factor with units of liter per kilogram (L/kg) as derived in Sections 302.660 through 302.666.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.651  The Human Nonthreshold Criterion

 

The Human Nonthreshold Criterion (HNC) of a substance is the concentration or level of a substance at which humans are protected from an unreasonable risk of disease caused by a nonthreshold toxic mechanism as a result of incidental exposure to or ingestion of surface waters of the State or ingestion of aquatic organisms taken from surface waters of the State.  HNCs are derived for those toxic substances for which any exposure, regardless of extent, carries some risk of damage as specified in subsections (a) and (b).

 

a)         For single substances, a risk level of one in one million (1 in 1,000,000) must be allowed (i.e., considered acceptable) to determine an HNC.

 

b)         For mixtures of substances, an additive risk level of one in one hundred thousand (1 in 100,000) must be allowed (i.e., considered acceptable) to determine an HNC.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.654  Determining the Risk Associated Intake

 

The Risk Associated Intake (RAI) is the maximum amount of a substance that if ingested daily for a lifetime, is expected to result in the risk of one additional case of human cancer in a population of one million.  Where more than one carcinogenic chemical is present, the RAI must be based on an allowed additive risk of one additional case of cancer in a population of one hundred thousand.  The RAI must be derived as specified in subsections (a) through (c).

 

a)         For those substances for which a human epidemiologic study has been performed, the RAI equals the product of the dose from exposure in units of milligrams of toxicant per kilogram body weight per day (mg/kg-d) that results in a 70-year lifetime cancer probability of one in one million, times the average weight of an adult human of 70 kilograms (kg).  The resulting RAI is expressed in milligrams toxicant per day (mg/d).  If more than one human epidemiologic study is available, the lowest exposure level resulting in a 70-year lifetime probability of cancer equal to a ratio of one in one hundred thousand must be used in calculating the RAI.

 

b)         In the absence of an epidemiologic study, for those toxic substances for which a carcinogenic potency factor (CPF) has been derived from studies of mammalian test species, the risk associated intake is calculated from the equation: 

 

RAI = K/CPF

 

Where:

 

RAI	=	Risk associated intake in milligrams per day (mg/d);
K	=	A constant consisting of the product of the average weight of an adult human, assumed to be 70 kg, and the allowed cancer risk level of one in one million (1/1,000,000); and
CPF	=	Carcinogenic Potency Factor is the risk of one additional cancer per unit dose from exposure.  The CPF is expressed in units of inverse milligrams per kilogram - day (l/mg/kg-d) as derived in subsections (b)(1) through (b)(7).

 

1)         Only those studies that fulfill the data requirement criteria of Section 302.606 must be used in calculating the CPF.

 

2)         The linear no-threshold dose-response relationship developed in the same manner as in the USEPA document "Mutagenicity and Carcinogenicity Assessment of 1,3-butadiene", incorporated by reference in 35 Ill. Adm. Code 301.106, must be used in obtaining the unit risk, defined as the 95th percentile upper bound risk of one additional cancer resulting from a lifetime exposure to a unit concentration of the substance being considered.  The CPF must be estimated from the unit risk in compliance with subsection (b)(7).  In calculating a CPF, the Agency must review alternate scientifically valid protocols if so requested.

 

3)         If in a study of a single species more than one type of tumor is induced by exposure to the toxic substance, the highest of the CPFs is used.

 

4)         If two or more studies vary in either species, strain, or sex of the test animal, or tumor type, the highest CPF is used.

 

5)         If more than one tumor of the same type is found in some of the test animals, these should be pooled so that the dose-response relationship is dose versus number of tumors per animal.  The potency estimate for this dose-response relationship is used if it is higher than estimates resulting from other methods.

 

6)         If two or more studies are identical regarding species, strain, and sex of the test animal, and tumor type, the highest of the CPFs is used.

 

7)         Calculation of an equivalent dose between animal species and humans using a surface area conversion, and conversion of units of exposure to dose in milligrams of toxicant per kilogram of body weight per day (mg/kg-d), must be performed as specified in the USEPA document "Mutagenicity and Carcinogenicity Assessment of 1,3-butadiene", incorporated by reference in 35 Ill. Adm. Code 301.106.

 

c)         If both a human epidemiologic study and a study of mammalian test species are available for use in subsections (a) and (b), the risk associated intake is determined as follows:

 

1)         When the human epidemiologic study provides evidence of a carcinogenic effect on humans, the RAI is calculated from the human epidemiology study as specified in subsection (a).

 

2)         When the mammalian study provides evidence of a carcinogenic effect on humans, but the human epidemiologic study does not, a cancer risk to humans is assumed and the risk associated intake is calculated as specified in subsection (b).

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.657  Determining the Human Nonthreshold Criterion

 

The HNC is calculated according to the equation:

 

HNC = RAI/[W + (F x BCF)]

 

where:

 

HNC	=	Human Nonthreshold Protection Criterion in milligrams per liter (mg/L);
RAI	=	Risk Associated Intake of a substance in milligrams per day (mg/d) that is associated with a lifetime cancer risk level equal to a ratio of one to 1,000,000 as derived in Section 302.654;
W	=	Per capita daily water consumption equal to 2 liters per day (L/d) for surface waters at the point of intake of a public or food processing water supply, or equal to 0.01 liters per day (L/d) which represents incidental exposure through contact or ingestion of small volumes of water while swimming or during other recreational activities for areas which are determined to be public access areas under Section 302.102(b)(3), or 0.001 liters per day (L/d) for other waters;
F	=	Assumed daily fish consumption in the United States equal to 0.020 kilograms per day (kg/d); and
BCF	=	Aquatic Life Bioconcentration Factor with units of liter per kilogram (L/kg) as derived in Section 302.663.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.658  Stream Flow for Application of Human Nonthreshold Criterion

 

The HNC applies at all times except during periods when flows are less than the harmonic mean flow (Qhm), as determined by:  

 

Qhm = N / SUM(1/Qi)

 

Where:

 

Qhm	=	harmonic mean flow,
N	=	number of daily values for streamflows, and
Qi	=	daily streamflow value on day i.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.660  Bioconcentration Factor

 

A Bioconcentration Factor is used to relate substance residue in aquatic organisms to the concentration of the substance in the waters in which the organisms reside.

 

(Source:  Added at 14 Ill. Reg. 2899, effective February 13, 1990)

 

Section 302.663  Determination of Bioconcentration Factors

 

A Bioconcentration Factor equals the concentration of a substance in all or part of an aquatic organism in milligrams per kilogram of wet tissue weight (mg/kg), divided by the concentration of the substance in the water to which the organism is exposed in milligrams of the substance per liter of water (mg/L).

 

a)         The Bioconcentration Factor is calculated from a field study if the following conditions are met:  

 

1)         Data are available to show that the concentration of the substance in the water to which the organism was exposed remained constant over the range of territory inhabited by the organism and for a period of time exceeding 28 days;

 

2)         Competing mechanisms for removal of the substance from solution did not affect the bioavailability of the substance; and

 

3)         The concentration of the substance to which the organism was exposed is less than the lowest concentration causing any adverse effects on the organism.

 

b)         In the absence of a field-derived Bioconcentration Factor, the Bioconcentration Factor is calculated from a laboratory test if the following conditions are met:

 

1)         The Bioconcentration Factor was calculated from measured concentrations of the toxic substance in the test solution;

 

2)         The laboratory test was of sufficient duration to have reached steady state, which is defined as a less than 10 percent change in the calculated Bioconcentration Factor over a 2-day period or 16 percent of the test duration, whichever is longer.  In the absence of a laboratory test that has reached steady state, the Bioconcentration Factor may be calculated from a laboratory test with a duration greater than 28 days if more than one test is available for the same species of organism;

 

3)         The concentration of the toxic substance to which the test organism was exposed is less than the lowest concentration causing any adverse effects on the organism;

 

4)         If more than one Bioconcentration Factor for the same species is available, the geometric mean of the Bioconcentration Factors is used; and

 

5)         The Bioconcentration Factor is calculated on a wet tissue weight basis.  A Bioconcentration Factor calculated using dry tissue weight must be converted to a wet tissue weight basis by multiplying the dry weight bioconcentration value by 0.1 for plankton and by 0.2 for individual species of fish and invertebrates.

 

c)         In the absence of any Bioconcentration Factors measured from field studies as specified in subsection (a) or laboratory studies that have reached steady state as specified in subsection (b), the Bioconcentration Factor is calculated according to the equation:

 

log BCF = A + B log Kow

 

Where:

 

BCF = Bioconcentration Factor;

 

Kow = The octanol/water partition coefficient measured as specified in ASTM E 1147, incorporated by reference in 35 Ill. Adm. Code 301.106 (If the Kow is not available from laboratory testing, it must be calculated from structure-activity relationships or available regression equations.); and

 

The constants A = -0.23 and B = 0.76 must be used unless a change in the value of the constants is requested (The Agency must honor requests for changes only if the changes are accompanied by scientifically valid supporting data.).

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.666  Utilizing the Bioconcentration Factor

 

The Bioconcentration Factor derived in Section 302.663 is used to calculate water quality criteria for a substance as specified below:

 

a)         When calculating a WDAPC as described in Section 302.633, the geometric mean of all available steady-state, whole-body Bioconcentration Factors for fish and shellfish species that constitute or represent a portion of the diet of indigenous wild and domestic animal species is used. Additional considerations in deriving a Bioconcentration Factor include:  

 

1)         An edible portion Bioconcentration Factor is converted to a whole-body Bioconcentration Factor for a fish or shellfish species by multiplying the edible portion Bioconcentration Factor by the ratio of the percent lipid in the whole body to the percent lipid in the edible portion of the same species.

 

2)         A Bioconcentration Factor calculated as described in Section 302.663(c) is converted to a whole-body Bioconcentration Factor by multiplying the calculated Bioconcentration Factor by the ratio of the percent lipid in the whole body to 7.6.

 

b)         When calculating either a human threshold criterion or a human nonthreshold criterion as described in Sections 302.642 through 302.648 or Sections 302.651 through 302.657, respectively, the geometric mean of all available edible portion Bioconcentration Factors for fish and shellfish species consumed by humans is used.  Additional considerations in deriving a Bioconcentration Factor include:  

 

1)         Edible portions include:

 

A)        Decapods – muscle tissue.

 

B)        Bivalve mollusks – total living tissue.

 

C)        Scaled fish – boneless, scaleless filets including skin except for bloater chubs in which the edible portion is the whole body excluding head, scales, and viscera.

 

D)        Smooth-skinned fish – boneless, skinless filets.

 

2)         A whole-body Bioconcentration Factor is converted to an edible portion Bioconcentration Factor by multiplying the whole-body Bioconcentration Factor of a species by the ratio of the percent lipid in the edible portion to the percent lipid in the whole body of the same species.

 

3)         A Bioconcentration Factor calculated as described in Section 302.663 is converted to an edible portion Bioconcentration Factor by multiplying the calculated Bioconcentration Factor by the ratio of the percent lipid in the edible portion to 7.6.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

 

Section 302.669  Listing of Derived Criteria

 

a)         The Agency must develop and maintain a listing of toxicity criteria pursuant to this Subpart.  This list must be made available to the public and updated whenever a new criterion is derived and must be published when updated in the Illinois Register.

 

b)         A criterion published pursuant to subsection (a) may be proposed to the Board for adoption as a numeric water quality standard.

 

c)         The Agency must maintain for inspection all information, including assumptions, toxicity data, and calculations, used to derive any toxicity criterion listed pursuant to subsection (a) until adopted by the Board as a water quality standard.

 

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)

Section 302.APPENDIX A   References to Previous Rules (Repealed)

 

(Source:  Repealed at 47 Ill. Reg. 4437, effective March 23, 2023)

Section 302.APPENDIX B   Sources of Codified Sections (Repealed)

 

(Source:  Repealed at 47 Ill. Reg. 4437, effective March 23, 2023)

Section 302.APPENDIX C   Maximum total ammonia nitrogen concentrations allowable for certain combinations of pH and temperature

 

Section 302.TABLE A   pH-Dependent Values of the AS (Acute Standard)

 

pH	Acute Standard (mg/L)
≤  7.6	15.0
7.7	14.4
7.8	12.1
7.9	10.1
8.0	8.41
8.1	6.95
8.2	5.73
8.3	4.71
8.4	3.88
8.5	3.20
8.6	2.65
8.7	2.20
8.8	1.84
8.9	1.56
9.0	1.32

 

(Source:  Added at 26 Ill. Reg. 16931, effective November 8, 2002)

Section 302.APPENDIX C   Maximum total ammonia nitrogen concentrations allowable for certain combinations of pH and temperature

 

Section 302.TABLE B   Temperature and pH-Dependent Values of the CS (Chronic Standard) for Fish Early Life Stages Absent

 

 

pH	Temperature, ˚Celsius
	0-7	8	9	10	11	12	13	14	15	16
6	11.3	10.6	9.92	9.30	8.72	8.17	7.66	7.19	6.74	6.32
6.1	11.2	10.5	9.87	9.25	8.67	8.13	7.62	7.15	6.70	6.28
6.2	11.2	10.5	9.81	9.19	8.62	8.08	7.58	7.10	6.66	6.24
6.3	11.1	10.4	9.73	9.12	8.55	8.02	7.52	7.05	6.61	6.19
6.4	11.0	10.3	9.63	9.03	8.47	7.94	7.44	6.98	6.54	6.13
6.5	10.8	10.1	9.51	8.92	8.36	9.84	7.35	6.89	6.46	6.06
6.6	10.7	9.99	9.37	8.79	8.24	7.72	7.24	6.79	6.36	5.97
6.7	10.5	9.81	9.20	8.62	8.08	7.58	7.11	6.66	6.25	5.86
6.8	10.2	9.58	8.98	8.42	7.90	7.40	6.94	6.51	6.10	5.72
6.9	9.93	9.31	8.73	8.19	7.68	7.20	6.75	6.33	5.93	5.56
7	9.60	9.00	8.43	7.91	7.41	6.95	6.52	6.11	5.73	5.37
7.1	9.20	8.63	8.09	7.58	7.11	6.67	6.25	5.86	5.49	5.15
7.2	8.75	8.20	7.69	7.21	6.76	6.34	5.94	5.57	5.22	4.90
7.3	8.24	7.73	7.25	6.79	6.37	5.97	5.60	5.25	4.92	4.61
7.4	7.69	7.21	6.76	6.33	5.94	5.57	5.22	4.89	4.59	4.30
7.5	7.09	6.64	6.23	5.84	5.48	5.13	4.81	4.51	4.23	3.97
7.6	6.46	6.05	5.67	5.32	4.99	4.68	4.38	4.11	3.85	3.61
7.7	5.81	5.45	5.11	4.79	4.49	4.21	3.95	3.70	3.47	3.25
7.8	5.17	4.84	4.54	4.26	3.99	3.74	3.51	3.29	3.09	2.89
7.9	4.54	4.26	3.99	3.74	3.51	3.29	3.09	2.89	2.71	2.54
8	3.95	3.70	3.47	3.26	3.05	2.86	2.68	2.52	2.36	2.21
8.1	3.41	3.19	2.99	2.81	2.63	2.47	2.31	2.17	2.03	1.91
8.2	2.91	2.73	2.56	2.40	2.25	2.11	1.98	1.85	1.74	1.63
8.3	2.47	2.32	2.18	2.04	1.91	1.79	1.68	1.58	1.48	1.39
8.4	2.09	1.96	1.84	1.73	1.62	1.52	1.42	1.33	1.25	1.17
8.5	1.77	1.66	1.55	1.46	1.37	1.28	1.20	1.13	1.06	0.99
8.6	1.49	1.40	1.31	1.23	1.15	1.08	1.01	0.95	0.89	0.84
8.7	1.26	1.18	1.11	1.04	0.98	0.92	0.86	0.80	0.75	0.71
8.8	1.07	1.01	0.94	0.88	0.83	0.78	0.73	0.68	0.64	0.60
8.9	0.92	0.86	0.81	0.76	0.71	0.66	0.62	0.58	0.55	0.51
9.0	0.79	0.74	0.69	0.65	0.61	0.57	0.54	0.50	0.47	0.44

 

*  At 15˚ C and above, the criterion for fish ELS Absent is the same as the criterion for fish ELS Present.

 

(Source:  Added at 26 Ill. Reg. 16931, effective November 8, 2002)

Section 302.APPENDIX C   Maximum total ammonia nitrogen concentrations allowable for certain combinations of pH and temperature

 

Section 302.TABLE C   Temperature and pH-Dependent Values of the CS (Chronic Standard) for Fish Early Life Stages Present

 

pH	Temperature, ˚Celsius
	0	14	16	18	20	22	24	26	28	30
6	6.95	6.95	6.32	5.55	4.88	4.29	3.77	3.31	2.91	2.56
6.1	6.91	6.91	6.28	5.52	4.86	4.27	3.75	3.30	2.90	2.55
6.2	6.87	6.87	6.24	5.49	4.82	4.24	3.73	3.28	2.88	2.53
6.3	6.82	6.82	6.19	5.45	4.79	4.21	3.70	3.25	2.86	2.51
6.4	6.75	6.75	6.13	5.39	4.74	4.17	3.66	3.22	2.83	2.49
6.5	6.67	6.67	6.06	5.33	4.68	4.12	3.62	3.18	2.80	2.46
6.6	6.57	6.57	5.97	5.25	4.61	4.05	3.56	3.13	2.75	2.42
6.7	6.44	6.44	5.86	5.15	4.52	3.98	3.50	3.07	2.70	2.37
6.8	6.29	6.29	5.72	5.03	4.42	3.89	3.42	3.00	2.64	2.32
6.9	6.12	6.12	5.56	4.89	4.30	3.78	3.32	2.92	2.57	2.35
7	5.91	5.91	5.37	4.72	4.15	3.65	3.21	2.82	2.48	2.18
7.1	5.67	5.67	5.15	4.53	3.98	3.50	3.08	2.70	2.38	2.09
7.2	5.39	5.39	4.90	4.31	3.78	3.33	2.92	2.57	2.26	1.99
7.3	5.08	5.08	4.61	4.06	3.57	3.13	2.76	2.42	2.13	1.87
7.4	4.73	4.73	4.30	3.78	3.32	2.92	2.57	2.26	1.98	1.74
7.5	4.36	4.36	3.97	3.49	3.06	2.69	2.37	2.08	1.83	1.61
7.6	3.98	3.98	3.61	3.18	2.79	2.45	2.16	1.90	1.67	1.47
7.7	3.58	3.58	3.25	2.86	2.51	2.21	1.94	1.71	1.50	1.32
7.8	3.18	3.18	2.89	2.54	2.23	1.96	1.73	1.52	1.33	1.17
7.9	2.80	2.80	2.54	2.24	1.96	1.73	1.52	1.33	1.17	1.03
8	2.43	2.43	2.21	1.94	1.71	1.50	1.32	1.16	1.02	0.90
8.1	2.10	2.10	1.91	1.68	1.47	1.29	1.14	1.00	0.88	0.77
8.2	1.79	1.79	1.63	1.43	1.26	1.11	0.97	0.86	0.75	0.66
8.3	1.52	1.52	1.39	1.22	1.07	0.94	0.83	0.73	0.64	0.56
8.4	1.29	1.29	1.17	1.03	0.91	0.80	0.70	0.62	0.54	0.48
8.5	1.09	1.09	0.99	0.87	0.76	0.67	0.59	0.52	0.46	0.40
8.6	0.92	0.92	0.84	0.73	0.65	0.57	0.50	0.44	0.39	0.34
8.7	0.78	0.78	0.71	0.62	0.55	0.48	0.42	0.37	0.33	0.29
8.8	0.66	0.66	0.60	0.53	0.46	0.41	0.36	0.32	0.28	0.24
8.9	0.56	0.56	0.51	0.45	0.40	0.35	0.31	0.27	0.24	0.21
9	0.49	0.49	0.44	0.39	0.34	0.30	0.26	0.23	0.20	0.18

 

(Source:  Added at 26 Ill. Reg. 16931, effective November 8, 2002)