Illinois Administrative Code
Title 35 - ENVIRONMENTAL PROTECTION
Part 601 - INTRODUCTION
Section 601.105 - Definitions

a) For 35 Ill. Adm. Code 601, 602, 603, and 604, unless a different meaning of a word or term is clear from the context:

"Act" means the Environmental Protection Act [415 ILCS 5 ].

"Agency" means the Illinois Environmental Protection Agency.

"Air Gap" means the unobstructed vertical distance through the free atmosphere between the water discharge point and the flood level rim of the receptacle.

"Atmospheric Vacuum Breaker" means a device designed to admit atmospheric pressure into a piping system whenever a vacuum is caused on the upstream side of the receptacle.

"Aquifer Property Data" means the porosity, hydraulic conductivity, transmissivity, and storage coefficient of an aquifer, head, and hydraulic gradient.

"Board" means the Illinois Pollution Control Board.

"Boil Order" means a notice to boil all drinking and culinary water for at least five minutes before use, issued by the proper authorities to the consumers of a public water supply affected, whenever the water being supplied may have become microbiologically contaminated.

"Certified Laboratory" means any laboratory certified under Section 4(o) of the Act or certified by USEPA for the specific parameters to be examined.

"Chlorine"

"Chlorine Demand" means the difference between the amount of chlorine applied to a given water and the amount of total available chlorine remaining at the end of the contact period. All test conditions (contact time, pH, and temperature) must be given, expressing the chlorine demand in a given water.

"Combined Chlorine" means the reaction product formed when chlorine has reacted with ammonia to form chloramines.

"Free Chlorine" means the residual chlorine existing in water as the sum of hypochlorous acid and hypochlorite ion.

"Total Chlorine" means the sum of the free chlorine and the combined chlorine.

"Community Water Supply" or "CWS" means a public water supply which serves or is intended to serve at least 15 service connections used by residents or regularly serves at least 25 residents. [415 ILCS 5/3.145]

"Confined Geologic Formations" are geologic water-bearing formations protected against the entrance of contamination by other geologic formations.

"Conventional Filtration Treatment" means a series of processes, including coagulation, flocculation, sedimentation, and filtration resulting in substantial particulate removal.

"Cross-connection" means any physical connection or arrangement between two otherwise separate piping systems where flow from one system to the other is possible.

"CT" or "CTcalc" is the product of "residual disinfectant concentration" (RDC or C) in mg/L determined before or at the first customer, and the corresponding "disinfectant contact time" (T) in minutes. If a supplier applies disinfectants at more than one point prior to the first customer, it must determine the CT of each disinfectant sequence before or at the first customer to determine the total percent inactivation or "total inactivation ratio". In determining the total inactivation ratio, the supplier must determine the RDC of each disinfection sequence and corresponding contact time before any subsequent disinfection application points.

"Disinfectant" means any agent, including chlorine, chlorine dioxide, chloramines, and ozone, added to water in any part of the treatment or distribution process, that is intended to kill or inactivate pathogenic microorganisms.

"DPD Method" means an analytical method for determining chlorine residual utilizing the reagent DPD (n-diethyl-p-phenylenediamine).

"Effective External Linkage" is the ability of a water system to communicate and exchange information with water customers, regulators, technical and financial assistance organizations, and other entities that routinely interact with the water system.

"Groundwater" means underground water which occurs within the saturated zone and geologic materials where the fluid pressure in the pore space is equal to or greater than atmospheric pressure. [415 ILCS 5/3.210]

"Head" means the sum of the elevation head, pressure head, and velocity head at a given point in an aquifer.

"Hydraulic Conductivity" means the rate of flow in gallons per day (gpd) through a cross section of one square foot (ft2) under a unit hydraulic gradient (gpd/ft2).

"Hydraulic Gradient" means the rate of change of total head per unit distance of flow in a given direction.

"Infrastructure" means all mains, pipes, and structures through which water is obtained and distributed to the public, including wells and well structures, intakes and cribs, pumping stations, treatment plants, reservoirs, storage tanks, and appurtenances, collectively or severally, actually used or intended to be used to furnish water for drinking or general domestic use.

"Interconnection" means a physical connection between two or more community water supply systems.

"Maximum Average Daily Demand" or "Maximum Demand" means the highest average daily production over seven consecutive days.

"New Community Water Supply" means, beginning after October 1, 1999, all new community water supplies and those water supplies that expand their infrastructure to serve or intend to serve at least 15 service connections used by residents or regularly serve at least 25 residents. Any water supply that is not currently a community water supply but adds residents so that the total served is 25 residents or more without constructing additional infrastructure will become a community water supply but will not be required to demonstrate capacity under 35 Ill. Adm. Code 602.103 unless the community water supply is on restricted status as required by 35 Ill. Adm. Code 602.106.

"Non-community Water Supply" means a public water supply that is not a community water supply. [415 ILCS 5/3.145]

"Official Custodian" means an individual who is an officer of an entity that is the owner of a community water supply and acts as the owner's agent in matters concerning the community water supply. [415 ILCS 45/9.4]

"Porosity" means the percentage of the bulk volume of a rock or soil that is occupied by interstices, whether isolated or connected, as defined by the ratio of the pore volume to the total volume of a representative sample of the medium.

"Public Water Supply" means all mains, pipes, and structures through which water is obtained and distributed to the public, including wells and well structures, intakes and cribs, pumping stations, treatment plants, reservoirs, storage tanks, and appurtenances, collectively or severally, actually used or intended for use for the purpose of furnishing water for drinking or general domestic use and which serve at least 15 service connections or which regularly serve at least 25 persons at least 60 days per year. [415 ILCS 5/3.365]

"Responsible Operator in Charge" means an individual who is designated as a Responsible Operator in Charge of a community water supply under Section 1 of the Public Water Supply Operations Act [415 ILCS 45/1] and 35 Ill. Adm. Code 603. [415 ILCS 45/9.6]

"Satellite Supply" means any community water supply that:

purchases all finished water from another community water supply;

does not provide any treatment other than chlorination or corrosion control; and

distributes finished water to the consumers.

"Sell Water" means to deliver or provide potable water, obtained from a public water supply subject to this Chapter, to the consumer, who is then individually or specifically billed for water service, or where any monetary assessment is levied or required and specifically used for water service. Water supply facilities owned or operated by political subdivisions, homeowners' associations, and not-for-profit associations, as well as privately owned utilities regulated by the Illinois Commerce Commission, are considered to sell water whether or not a charge is specifically made for water.

"SEP" means special exception permit.

"Service Connection" is the opening, including all fittings and appurtenances, at the water main through which water is supplied to the user through a water service line.

"Storage Coefficient" means the volume of water an aquifer releases from or takes into storage per unit surface area of the aquifer per unit change in head.

"Surface Water" means all tributary streams and drainage basins, including natural lakes and artificial reservoirs, which may affect a specific water supply above the point of water supply intake.

"Surface Water Supply Source" means any surface water used as a water source for a public water supply.

"Supply" means a community water supply.

"Transmissivity" means the rate in gallons per minute (gpm), at which water is transmitted horizontally through a unit width by the total saturated thickness of an aquifer, in feet (ft), under a unit hydraulic gradient (gpm/ft).

"Water Main" means any pipe for distributing potable water that serves or is accessible to more than one property, dwelling, or rental unit and is exterior to buildings.

"Water Service Line" means any pipe from the water main or source of potable water supply that serves or is accessible to not more than one property, dwelling, or rental unit of the user.

"Well Hydraulics" means equations that are applied to understand the effect that a pumping well structure has on inducing the movement of water through permeable rock formations and certain aquifer properties to determine the rate of withdrawal of the well. This term is inclusive of equations that quantify wellbore skin effects/well loss.

"Wellhead Protection Area" or "WHPA" means the surface and subsurface recharge area surrounding a community water supply well or well field, delineated outside of any applicable setback zones (under Section 17.1 of the Act) established under Illinois' Wellhead Protection Program, through which contaminants are reasonably likely to move toward the well or well field.

"Wellhead Protection Measures" means management practices needed to mitigate existing and future threats to the water quality within the delineated WHPA.

"Wellhead Protection Program" means the Wellhead Protection Program for the State of Illinois, approved by USEPA under section 1428 of the SDWA (42 U.S.C. 300h-7).

b) Terms not specifically defined in subsection (a), will have the meanings ascribed in 35 Ill. Adm. Code 611.

c) Terms not specifically defined in subsection (a) or (b) will have the meanings specified in The Water Dictionary, incorporated by reference in Section 601.115.