Illinois Administrative Code

Section 301.260 Combined Sewer Service Area "Combined Sewer Service Area" means a specific geographical drainage area served by a combined sewer system. Areas served by separate sewer systems which enter the combined system are not included. Undeveloped areas within a combined se…

Section 301.265 Construction "Construction" means commencement of on-site fabrication, erection, or installation of a treatment works, sewer, or wastewater source; or the reinstallation at a new site of any existing treatment works, sewer, or wastewater source.

Section 301.267 Conversion Factor "Conversion Factor" means the fraction of the total metal found as dissolved in the toxicity tests used to derive the water quality standards of 35 Ill. Adm. Code 302. The conversion factors are used to convert total metals water quality standard…

Section 301.270 Dilution Ratio "Dilution Ratio" means the ratio of the seven-day once in ten year low flow of the receiving stream or the lowest flow of the receiving stream when effluent discharge is expected to occur, whichever is greater, to the average flow of the treatment w…

Section 301.275 Effluent "Effluent" means any wastewater discharged, directly or indirectly, to the waters of the State or to any storm sewer, and the runoff from land used for the disposition of wastewater or sludges, but does not otherwise include nonpoint source discharges suc…

Section 301.280 Hearing Board "Hearing Board" means an Agency hearing board of one or more employees, appointed by the Director under 35 Ill. Adm. Code 309.115(b), that conducts public hearings and makes recommendations to the Agency on issuing or denying NPDES permits. (Source: …

Section 301.282 Incidental Contact Recreation "Incidental Contact Recreation" means any recreational activity in which human contact with the water is incidental and in which the probability of ingesting appreciable quantities of water is minimal, such as fishing; commercial boat…

Section 301.285 Industrial Wastes "Industrial Wastes" means any solid, liquid, or gaseous wastes resulting from any process of industry, manufacturing, trade, or business or from the development, processing, or recovery, except for agricultural crop raising, of any natural resour…

Section 301.290 Institute (Repealed) (Source: Repealed at 47 Ill. Reg. 4415, effective March 23, 2023)

Section 301.295 Interstate Waters "Interstate Waters" are waters that cross or form part of the border between Illinois and one or more other states. (Source: Amended at 47 Ill. Reg. 4415, effective March 23, 2023)

Section 301.300 Intrastate Waters "Intrastate Waters" are all waters of Illinois which are not interstate waters.

Section 301.301 Lake Michigan Lakewide Management Plan "Lake Michigan Lakewide Management Plan" or "LaMP" is a plan to manage the Illinois portion of Lake Michigan as approved by USEPA. (Source: Amended at 47 Ill. Reg. 4415, effective March 23, 2023)

Section 301.305 Land Runoff "Land Runoff" means water reaching the waters of the State as runoff resulting from precipitation.

Section 301.307 Lower Des Plaines River "Lower Des Plaines River" means Des Plaines River from the confluence with Chicago Sanitary and Ship Canal to the Interstate 55 Bridge. (Source: Added at 35 Ill. Reg. 15071, effective August 23, 2011)

Section 301.310 Marine Toilet "Marine Toilet" means any toilet on or within any watercraft.

Section 301.311 Method Detection Level "Method Detection Level" is the minimum concentration of an analyte (substance) that can be measured and reported with 99 percent confidence that the analyte concentration is greater than zero as determined by the procedure set forth in Appe…

Section 301.312 Minimum Level "Minimum Level" or "ML" is the concentration at which the entire analytical system must give a recognizable signal and acceptable calibration point. The ML is the concentration in a sample that is equivalent to the concentration of the lowest calibra…

Section 301.313 Metals Translator "Metals Translator" means the fraction of total metal that is dissolved in the effluent or downstream water. The metals translator calculates a total metal permit limit from a dissolved metal water quality standard. In the absence of site-specifi…

Section 301.315 Modification "Modification" means: a) Any physical change in a treatment works which involves different or additional processes or equipment or which increases or decreases the capacity or efficiency of the treatment works; or b) Any change in the number or locati…

Section 301.320 New Source "New Source" means any wastewater source, the construction of which is commenced on or after the effective date of the applicable provisions of this Chapter.

Section 301.323 Primary Contact Recreation "Primary Contact Recreation" means any recreational activity in which human contact consists of full body contact with the waters, such as swimming, diving or jumping, and includes all Incidental Contact Recreation. (Source: Added at 35 …

Section 301.324 Non-contact Recreation and Non-recreational a) "Non-contact Recreation" means any recreational or other water use in which human contact with the water is unlikely, such as pass through commercial or recreational navigation, and where physical conditions or hydrol…

Section 301.325 NPDES "NPDES" means the National Pollutant Discharge Elimination System for issuing, establishing conditions for, and denying permits under Section 402 of the CWA. All terms used concerning NPDES that the CWA or regulations adopted under it define have those meani…

Section 301.330 Other Wastes "Other Wastes" means garbage, refuse, wood residues, sand, lime, cinders, ashes, offal, night soil, silt, oil, tar, dye stuffs, acids, chemicals and all other substances not sewage or industrial waste whose discharge would cause water pollution or a v…

Section 301.331 Outlier (Repealed) (Source: Repealed at 47 Ill. Reg. 4415, effective March 23, 2023)

Section 301.335 Person "Person" means any individual, partnership, co-partnership, firm, company, corporation, association, joint stock company, trust, estate, political subdivision, state agency, or any other legal entity, or their legal representative, agent or assigns.

Section 301.340 Pollutant "Pollutant" means dredged spoil, solid waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt and industrial, muni…

Section 301.341 Pollutant Minimization Program "Pollutant Minimization Program" means a structured set of activities to improve processes and pollutant controls that will prevent and reduce pollutant loading. (Source: Amended at 47 Ill. Reg. 4415, effective March 23, 2023)

Section 301.345 Population Equivalent "Population Equivalent" is a term used to evaluate the impact of industrial or other waste on a treatment works or stream. One population equivalent is 100 gallons (380 l) of sewage per day, containing 0.17 pounds (77 g) of BOD5 (five day bio…

Section 301.346 Preliminary Effluent Limitation "Preliminary Effluent Limitation" or "PEL" is an estimate of an allowable discharge considering mixing or dilution. (Source: Amended at 47 Ill. Reg. 4415, effective March 23, 2023)

Section 301.350 Pretreatment Works "Pretreatment Works" means a treatment works designed and intended to treat wastewater from an indirect discharge or industrial user as defined in 40 CFR 403 (2022) before it is introduced into a sewer system tributary to a publicly owned or pub…

Section 301.355 Primary Contact "Primary Contact" means any recreational or other water use in which there is prolonged and intimate contact with the water involving considerable risk of ingesting water in quantities sufficient to pose a significant health hazard, such as swimmin…

Section 301.356 Projected Effluent Quality "Projected Effluent Quality" or "PEQ" is the amount of a contaminant estimated to be discharged by a facility or activity considering a statistical analysis of the discharge or activity. (Source: Amended at 47 Ill. Reg. 4415, effective M…

Section 301.360 Public and Food Processing Water Supply "Public and Food Processing Water Supply" means any water use in which water is withdrawn from surface waters of the State for human consumption or for processing of food products intended for human consumption.

Section 301.365 Publicly Owned Treatment Works "Publicly Owned Treatment Works" means a treatment works owned by a municipality, sanitary district, county, or state agency, and which treats domestic and industrial wastes collected by a publicly owned or regulated sewer system. In…

Section 301.370 Publicly Regulated Treatment Works "Publicly Regulated Treatment Works" means otherwise private companies that are regulated as public utilities engaged in the disposal of domestic and industrial wastes and regulated by the Illinois Commerce Commission under the P…

Section 301.371 Quantification Level "Quantification Level" is a measurement of the concentration of a contaminant obtained by using a specified laboratory procedure calibrated at a specified concentration above the method detection level. It is considered the lowest concentratio…

Section 301.372 Reasonable Potential Analysis "Reasonable Potential Analysis" or "Reasonable Potential to Exceed" means the procedure to predict whether an existing or future discharge would cause or contribute to a violation of water quality standards, criteria or values. (Sourc…

Section 301.373 Same Body of Water "Same Body of Water" means that, for purposes of evaluating intake toxic substances consistent with 35 Ill. Adm. Code 352.425, the Agency will consider intake toxic substances to be from the same body of water if the Agency finds that the intake…

Section 301.375 Sanitary Sewer "Sanitary Sewer" means a sewer that carries wastewater together with incidental land runoff. (Source: Amended at 3 Ill. Reg. 25, page 190, effective June 21, 1979)

Section 301.380 Secondary Contact "Secondary Contact" means any recreational or other water use in which contact with the water is either incidental or accidental and in which the probability of ingesting appreciable quantities of water is minimal, such as fishing, commercial and…

Section 301.385 Sewage "Sewage" means water-carried human and related wastes from any source. (Source: Amended at 3 Ill. Reg. 25 page 190, effective June 21, 1979)

Section 301.390 Sewer "Sewer" means a stationary means of transport or stationary system of transport, excluding natural waterways, constructed and operated for the purpose of collecting and transporting wastewater or land runoff, or both. (Source: Amended at 3 Ill. Req. 25 page …

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…