Illinois Administrative Code

Section 301.395 Sludge "Sludge" means any solid, semisolid, or liquid waste generated from a municipal, commercial, or industrial wastewater treatment plant, water supply treatment plant, or air pollution control facility, or any other waste having similar characteristics and eff…

Section 301.400 Standard of Performance "Standard of Performance" means a standard promulgated by the Administrator under Section 306 of the CWA for the control of the discharge of pollutants reflecting the greatest degree of effluent reduction that the Administrator determines t…

Section 301.405 STORET "STORET" means the national water quality data system of the federal Environmental Protection Agency.

Section 301.410 Storm Sewer "Storm Sewer" means a sewer intended to receive only land runoff.

Section 301.411 Total Maximum Daily Load "Total Maximum Daily Load" or "TMDL" is the sum of the individual wasteload allocations for point sources and load allocations for nonpoint sources and natural background, as more fully defined at 40 CFR 130.2(i). A TMDL sets and allocates…

Section 301.413 Total Metal "Total Metal" means the dissolved fraction of metal in a solution plus the suspended fraction. (Source: Added at 27 Ill. Reg. 158, effective December 20, 2002)

Section 301.415 Treatment Works "Treatment Works" means individually or collectively those constructions or devices (except sewers, and except constructions or devices used for the pretreatment of wastewater prior to its introduction into publicly owned or regulated treatment wor…

Section 301.420 Underground Waters "Underground Waters" means any waters of the State located beneath the surface of the earth.

Section 301.421 Wasteload Allocation "Waste Load Allocation" or "WLA" is the portion of receiving water's loading capacity that is allocated to one of its existing or future point sources of pollution, as more fully defined at 40 CFR 130.2(h). In the absence of a TMDL approved by…

Section 301.425 Wastewater "Wastewater" means sewage, industrial waste, or other waste, or any combination of these, whether treated or untreated, plus any admixed land runoff.

Section 301.430 Wastewater Source "Wastewater Source" means any equipment, facility, or other source of any type that discharges wastewater, directly or indirectly to the waters of the State. (Source: Amended at 47 Ill. Reg. 4415, effective March 23, 2023)

Section 301.435 Watercraft "Watercraft" means every type of boat, ship or barge used or capable of being used as a means of transportation on water.

Section 301.440 Waters "Waters" means all accumulations of water, surface and underground, natural, and artificial, public and private, or parts thereof, which are wholly or partially within, flow through, or border upon the State of Illinois, except that sewers and treatment wor…

Section 301.441 Water Quality Based Effluent Limitation "Water Quality Based Effluent Limitation" or "WQBEL" is a limit imposed in a permit so that the applicable water quality standard, criteria or value is not exceeded outside of a designated mixing zone. (Source: Amended at 47…

Section 301.442 Wet Weather Point Source "Wet Weather Point Source" means any discernible, confined, and discrete conveyance from which pollutants are, or may be, discharged as the result of a wet weather event. Discharges from wet weather point sources must include only: dischar…

Section 301.443 Whole Effluent Toxicity "Whole Effluent Toxicity" or "WET" means a test procedure that determines the effect of an effluent on aquatic life. (Source: Amended at 47 Ill. Reg. 4415, effective March 23, 2023)

Section 301.APPENDIX A References to Previous Rules (Repealed) (Source: Repealed at 47 Ill. Reg. 4415, effective March 23, 2023)

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 t…

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 con…

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 co…

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. …

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 Us…

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 f…

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 …

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. F…

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 offensiv…

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 Il…

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 302.209 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 …

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 …

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 c…

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 standa…

Section 302.213 Effluent Modified Waters (Ammonia) (Repealed) (Source: Repealed at 26 Ill. Reg. 16931, effective November 08, 2002) SUBPART C: PUBLIC AND FOOD PROCESSING WATER SUPPLY STANDARDS

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 tre…

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 2…

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.…

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 …

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…

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) SUBPART D: CHICAGO AREA WATERWAY SYSTEM AND LOWER DES PLAINES RIVER WATER QUAL…

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 B…

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 industri…

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, …

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 I…