Section 611.101 Definitions

TITLE 35: ENVIRONMENTAL PROTECTION

SUBTITLE F: PUBLIC WATER SUPPLIES

CHAPTER I: POLLUTION CONTROL BOARD

PART 611 PRIMARY DRINKING WATER STANDARDS

SECTION 611.101 DEFINITIONS

Section 611.101  Definitions

The terms this Section defines have

the given meanings in this Part:

"Act"

means the Environmental Protection Act [415 ILCS 5].

"Agency"

means the Illinois Environmental Protection Agency.

BOARD NOTE:

The Department of Public Health (Public Health or DPH) regulates non-CWSs,

including NTNCWSs and transient non-CWSs.  "Agency" means Public

Health

if implementation by Public Health

occurs with regard to non-CWS suppliers

.

"Approved

source of bottled water", for the purposes of Section 611.130(d)(4), means

a source of water and the packaged water it provides, whether from a spring,

artesian well, drilled well, municipal water supply, or any other source, that the

provider inspects, samples, analyzes, and finds has a safe and sanitary quality

under laws and regulations of State and local government agencies having

jurisdiction, as evidenced by current certificates or notations of approval in

the packaging plant from each government agency having jurisdiction over the

source, the water it bottles, and distributing the water in commerce.

BOARD NOTE:  This

definition derives from 40 CFR 142.62(g)(2) and 21 CFR 129.3(a). The Board

cannot compile an exhaustive listing of all federal, State, and local laws regulating

bottled water and bottling water.  However, the Board is aware of some:  the

Illinois Food, Drug and Cosmetic Act [410 ILCS 620], the Bottled Water Act [815

ILCS 310], the DPH Water Well Construction Code (77 Ill. Adm. Code 920), the

DPH Water Well Pump Installation Code (77 Ill. Adm

CFR 129.3(a). The Board

cannot compile an exhaustive listing of all federal, State, and local laws regulating

bottled water and bottling water.  However, the Board is aware of some:  the

Illinois Food, Drug and Cosmetic Act [410 ILCS 620], the Bottled Water Act [815

ILCS 310], the DPH Water Well Construction Code (77 Ill. Adm. Code 920), the

DPH Water Well Pump Installation Code (77 Ill. Adm. Code 925), the federal

bottled water quality standards (21 CFR 103.35), the federal drinking water

processing and bottling standards (21 CFR 129), the federal Current Good

Manufacturing Practice in Manufacturing, Packing, or Holding Human Food (21 CFR

110), the federal Fair Packaging and Labeling Act (15 U.S.C. 1451 et seq.), and

the federal Fair Packaging and Labeling regulations (21 CFR 201).

"Bag filters" means

pressure-driven separation devices that remove particulate matter larger than

one micrometer using an engineered porous filtration media.  These are

typically a non-rigid fabric filtration media housed in a pressure vessel where

the direction of flow is from the inside to outside the bag.

"Bank filtration" means

a water treatment process using a well to recover surface water naturally infiltrating

into groundwater through a river bed or banks.  A nearby pumping water supply

or other wells typically enhances infiltration by the hydraulic gradient they

impose.

"Best

available technology" or "BAT" means the best technology,

treatment techniques, or other means that USEPA determines are available for

the contaminant in question.  Subpart F specifies BAT.

"Bin classification" or "bin"

means, for Subpart Z, the appropriate of the four treatment categories (Bin 1,

Bin 2, Bin 3, or Bin 4) that a filtered system supplier assigns itself under

Section 611.1010 based on the results of source water Cryptosporidium

monitoring under Section 611.1001. This bin classification determines the

degree of additional Cryptosporidium treatment, if any, the filtered system

supplier must provide

ans, for Subpart Z, the appropriate of the four treatment categories (Bin 1,

Bin 2, Bin 3, or Bin 4) that a filtered system supplier assigns itself under

Section 611.1010 based on the results of source water Cryptosporidium

monitoring under Section 611.1001. This bin classification determines the

degree of additional Cryptosporidium treatment, if any, the filtered system

supplier must provide.

BOARD NOTE:  This

definition derives from 40 CFR 141.710 and 71 Fed. Reg. 654, 657 (Jan. 5,

2006).

"Board"

means the Illinois Pollution Control Board.

"Cartridge filter" means

a pressure-driven separation device that removes particulate matter larger than

1 micrometer using an engineered porous filtration media.  A cartridge filter

typically has rigid or semi-rigid self-supporting filter elements housed in a pressure

vessel in which flow is from outside to inside the cartridge.

"CAS

No." means "Chemical Abstracts Services Number".

"Clean compliance history"

means, for Subpart AA, a record of no MCL violations under Section 611.325; no

monitoring violations under Subpart L or Subpart AA; and no coliform treatment

technique trigger exceedances or treatment technique violations under Subpart

AA.

"Coagulation"

means a process using coagulant chemicals and mixing that destabilizes and

agglomerates colloidal and suspended materials into flocs.

"Combined distribution system"

means the interconnected distribution system comprising the distribution

systems of wholesale systems and of the consecutive systems that receive

finished water.

"Community

water system" or "CWS" means a PWS serving at least 15 service

connections used by year-round residents or regularly serving at least 25

year-round residents.

BOARD NOTE:

This definition differs slightly from that of Section 3.145 of the Act.

"Compliance

cycle" means the nine-calendar-year cycle during which PWSs must monitor.

Each compliance cycle consists of three three-year compliance periods

system" or "CWS" means a PWS serving at least 15 service

connections used by year-round residents or regularly serving at least 25

year-round residents.

BOARD NOTE:

This definition differs slightly from that of Section 3.145 of the Act.

"Compliance

cycle" means the nine-calendar-year cycle during which PWSs must monitor.

Each compliance cycle consists of three three-year compliance periods.  The

first calendar cycle ran calendar years 1993 through 2001, the second ran 2002

through 2010, the third ran 2011 through 2019, etc.

"Compliance

period" means a three-calendar-year period within a compliance cycle.

Each compliance cycle has three three-year compliance periods.  For example,

the first compliance period ran calendar years 1993 through 1995, the second ran

1996 through 1998, and the third ran 1999 through 2001 within the first

compliance cycle.

"Comprehensive

performance evaluation" or "CPE" is a thorough review and

analysis of a treatment plant's performance-based capabilities and associated

administrative, operational, and maintenance practices.  The supplier conducts

a CPE to identify factors that may adversely affect a plant's ability to

comply.  The supplier conducts a CPE to achieve compliance and emphasize

approaches it can implement without significant capital improvements.

BOARD NOTE:

The final sentence of the definition of "comprehensive performance

evaluation" in 40 CFR 141.2 is Section 611.160(a)(2), since it contains

substantive elements.

"Confluent

growth" means a continuous bacterial growth covering the entire filtration

area or portion of a membrane filter in which bacterial colonies are not

discrete.

"Consecutive system"

means a PWS receiving some or all of its finished water from one or more

wholesale systems.  Delivery may be through a direct connection or the

distribution system of one or more consecutive systems.

"Contaminant"

means any physical, chemical, biological, or radiological substance or matter

in water

rtion of a membrane filter in which bacterial colonies are not

discrete.

"Consecutive system"

means a PWS receiving some or all of its finished water from one or more

wholesale systems.  Delivery may be through a direct connection or the

distribution system of one or more consecutive systems.

"Contaminant"

means any physical, chemical, biological, or radiological substance or matter

in water.

"Conventional

filtration treatment" means a series of processes, including coagulation,

flocculation, sedimentation, and filtration, resulting in substantial "particulate

removal".

"CT" or "CT

calc

"

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.  (See the definition of "CT

99.9

".)

"CT

99.9

" is

the CT value required for 99.9 percent (3-log) inactivation of Giardia lamblia

cysts. Tables 1.1 through 1.6, 2.1, and 3.1 of Appendix B list CT

99.9

values for a variety of disinfectants and conditions.  (See the definition of "inactivation

ratio".)

BOARD NOTE:  This definition

derives from the definition of "CT" in 40 CFR 141.2.

"Diatomaceous

earth filtration" means a process resulting in substantial particulate

removal:

The process

deposits a precoat cake of diatomaceous earth filter media on a support

membrane (septum); and

The process

continuously adds additional filter media, known as body feed, to the feed

water to maintain permeability of the filter cake while filtering the water by

passing through the cake on the septum

s

earth filtration" means a process resulting in substantial particulate

removal:

The process

deposits a precoat cake of diatomaceous earth filter media on a support

membrane (septum); and

The process

continuously adds additional filter media, known as body feed, to the feed

water to maintain permeability of the filter cake while filtering the water by

passing through the cake on the septum.

"Direct

filtration" means a series of processes, including coagulation and

filtration but excluding sedimentation, resulting in substantial particulate

removal.

"Disinfectant"

means any oxidant, including chlorine, chlorine dioxide, chloramines, and ozone,

that a supplier adds to water in any part of the treatment or distribution

process to kill or inactivate pathogenic microorganisms.

"Disinfectant

contact time" or "T" means the time in minutes that water moves

from the point of disinfectant application or the previous point of RDC

measurement to a point before or at the point where the supplier measures RDC.

If the

supplier measures only one RDC, T is the time in minutes that water moves from

the point of disinfectant application to a point before or at the point where

RDC is measured.

If the

supplier measures more than one RDC:

For the first measurement of RDC, T is the time in minutes that water moves

from the first or only point of disinfectant application to a point before or

at the point where the supplier measures the first RDC; and

For subsequent measurements of RDC, T is the time in minutes that water moves

from the previous RDC measurement point to the RDC measurement point where the

supplier calculates the particular T.

In pipelines, the supplier must calculate T based on "plug

flow" by dividing the internal volume of the pipe by the maximum hourly

flow rate through that pipe.

Within mixing basins and storage reservoirs, the supplier must determine

T using tracer studies or an equivalent demonstration

e previous RDC measurement point to the RDC measurement point where the

supplier calculates the particular T.

In pipelines, the supplier must calculate T based on "plug

flow" by dividing the internal volume of the pipe by the maximum hourly

flow rate through that pipe.

Within mixing basins and storage reservoirs, the supplier must determine

T using tracer studies or an equivalent demonstration.

"Disinfection"

means a process that inactivates pathogenic organisms in water by chemical

oxidants or equivalent agents.

"Disinfection

byproduct" or "DBP" means a chemical byproduct forming when

disinfectants used for microbial control react with naturally occurring

compounds already present in source water.  DBPs include bromodichloromethane,

bromoform, chloroform, dichloroacetic acid, bromate, chlorite,

dibromochloromethane, and certain haloacetic acids.

"Disinfection

profile" is a summary of daily Giardia lamblia inactivation through a

treatment plant.  The procedure for developing a disinfection profile is in Section

611.742.

"Distribution

system" includes all points downstream of an "entry point" to

the point of consumer ownership.

"Domestic

or other non-distribution system plumbing problem" means a coliform

contamination problem in a PWS having more than one service connection that is

limited to the specific service connection from which the supplier took the

coliform-positive sample.

"Dose

equivalent" means the product of the absorbed dose from ionizing radiation

and the factors accounting for differences in biological effect due to the type

of radiation and its distribution in the body.

BOARD NOTE:

The International Commission on Radiation Units and Measurements (ICRU)

specifies "dose equivalent" as the product of the absorbed dose (D),

quality factor (QF), dose distribution factor (DF), and other necessary

factors.  See "Radiation Quantities and Units," International

Commission on Radiological Units and Measurements (ICRU) Report 10a, Handbook

84, U.S

ibution in the body.

BOARD NOTE:

The International Commission on Radiation Units and Measurements (ICRU)

specifies "dose equivalent" as the product of the absorbed dose (D),

quality factor (QF), dose distribution factor (DF), and other necessary

factors.  See "Radiation Quantities and Units," International

Commission on Radiological Units and Measurements (ICRU) Report 10a, Handbook

84, U.S. Department of Commerce, National Bureau of Standards (1962).

"Dual sample set" means

a set of two samples the supplier collects at the same time and same location, analyzing

one sample for TTHM and the other sample for HAA5. A supplier collects dual

sample sets to conduct an IDSE under Subpart W and determine compliance with

the TTHM and HAA5 MCLs under Subpart Y.

"E. coli" means

Escherichia coli, a species of bacteria used as a specific indicator of fecal

contamination and potential harmful pathogens.

BOARD NOTE:  This definition

derives from 78 Fed. Reg. 10270, 10271 (Feb. 13, 2013).

"Enhanced

coagulation" means adding sufficient coagulant to improve removing

disinfection byproduct (DBP) precursors by conventional filtration treatment.

"Enhanced

softening" means using precipitative softening to improve removing

disinfection byproduct (DBP)

precursors

.

"Entry

point" means a point just downstream of the final treatment operation but

upstream of the first user and any mixing with other water.  If the supplier

uses raw water without treatment, the "entry point" is the raw water

source.  If a PWS receives treated water from another PWS, the "entry

point" is a point just downstream of the other PWS but upstream of the

first user and any mixing with other water.

"Filter

profile" is a graphical representation of individual filter performance

based on continuous turbidity measurements or total particle counts versus time

for an entire filter run from startup through backwash, including an assessment

of filter performance while the supplier backwashes another filter

nstream of the other PWS but upstream of the

first user and any mixing with other water.

"Filter

profile" is a graphical representation of individual filter performance

based on continuous turbidity measurements or total particle counts versus time

for an entire filter run from startup through backwash, including an assessment

of filter performance while the supplier backwashes another filter.

"Filtration"

means a process passing water through porous media to remove particulate

matter.

"Finished water" means

water that the supplier introduces into the distribution system of a PWS

intending the water for distribution and consumption without further treatment,

except treatment necessary to maintain water quality in the distribution system

(e.g., booster disinfection, addition of corrosion control chemicals, etc.).

"Flocculation"

means a process enhancing agglomeration or collection of smaller floc particles

into larger, more easily settleable particles through gentle hydraulic or

mechanical stirring.

"Flowing stream" means a

course of running water flowing in a definite channel.

"40/30 certification"

means the certification a supplier submits to the Agency under Section 611.923

that the supplier had no TTHM or HAA5 monitoring violations and no individual

sample from its system exceeded 0.040 mg/L TTHM or 0.030 mg/L HAA5 during eight

consecutive calendar quarters.

BOARD NOTE:  This definition

derives from 40 CFR 141.603(a).

"GAC10" means granular

activated carbon (GAC) filter beds with an empty-bed contact time of 10 minutes

based on average daily flow and a carbon reactivation frequency of every 180

days, except that the reactivation frequency for GAC10 a supplier uses as a

best available technology to comply with the MCLs under Section 611.312(b)(2)

is 120 days

.

"GAC20" means granular

activated carbon filter beds with an empty-bed contact time of 20 minutes based

on average daily flow and a carbon reactivation frequency of every 240 days

and a carbon reactivation frequency of every 180

days, except that the reactivation frequency for GAC10 a supplier uses as a

best available technology to comply with the MCLs under Section 611.312(b)(2)

is 120 days

.

"GAC20" means granular

activated carbon filter beds with an empty-bed contact time of 20 minutes based

on average daily flow and a carbon reactivation frequency of every 240 days.

"GC"

means "gas chromatography" or "gas-liquid phase

chromatography".

"GC/MS"

means gas chromatography (GC) followed by mass spectrometry (MS).

"Gross

alpha particle activity" means the total radioactivity due to alpha

particle emission as inferred from measurements on a dry sample.

"Gross

beta particle activity" means the total radioactivity due to beta particle

emission as inferred from measurements on a dry sample.

"Groundwater system" or "GWS"

means a PWS using only groundwater sources, including a consecutive system receiving

finished groundwater

.

BOARD NOTE:  This definition

derives from 40 CFR 141.400(b).

"Groundwater

under the direct influence of surface water" means any water beneath the ground

surface with significant occurrence of insects or other macroorganisms, algae,

or large-diameter pathogens, such as Giardia lamblia or Cryptosporidium, or

significant and relatively rapid shifts in water characteristics, such as

turbidity, temperature, conductivity, or pH, that closely correlate to

climatological or surface water conditions. "Groundwater under the direct

influence of surface water" is as determined under Section 611.212.

"Haloacetic

acids (five)" or "HAA5" means the sum of the concentrations in

milligrams per liter (mg/L) of five haloacetic acid compounds (monochloroacetic

acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and

dibromoacetic acid), rounded to two significant figures after summing.

"Halogen"

means one of the chemical elements chlorine, bromine, or iodine

der Section 611.212.

"Haloacetic

acids (five)" or "HAA5" means the sum of the concentrations in

milligrams per liter (mg/L) of five haloacetic acid compounds (monochloroacetic

acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and

dibromoacetic acid), rounded to two significant figures after summing.

"Halogen"

means one of the chemical elements chlorine, bromine, or iodine.

"Hazard Index (HI)" is

the sum of component hazard quotients (HQs), which are calculated by dividing

the measured regulated PFAS component contaminant concentration in water (e.g.,

expressed as parts per trillion (ppt) or nanograms per liter (ng/l)) by the

associated health-based water concentration (HBWC) expressed in the same units

as the measured concentration (e.g., ppt or ng/l). For PFAS, a mixture Hazard

Index greater than 1 (unitless) is an exceedance of the MCL.

"Hazard quotient (HQ)"

means the ratio of the measured concentration in drinking water to the

health-based water concentration (HBWC).

"Health-based water

concentration (HBWC)" means level below which there are no known or

anticipated adverse health effects over a lifetime of exposure, including

sensitive populations and life stages, and allows for an adequate margin of

safety.

"HFPO-DA or GenX chemicals"

means Chemical Abstract Service registration number 122499-17-6, chemical

formula C6F11O3-, International Union of Pure and Applied Chemistry preferred

name 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoate, along with its

conjugate acid and any salts, derivatives, isomers, or combinations thereof.

"HPC"

means "heterotrophic plate count", as measured under Section

611.531(a)(2)(C)

.

"Hydrogeologic sensitivity

assessment", for Subpart S, means a determination of whether a GWS

supplier obtains water from a hydrogeologically sensitive setting.

BOARD NOTE:  This definition

derives from 40 CFR 141.400(c)(5)

with its

conjugate acid and any salts, derivatives, isomers, or combinations thereof.

"HPC"

means "heterotrophic plate count", as measured under Section

611.531(a)(2)(C)

.

"Hydrogeologic sensitivity

assessment", for Subpart S, means a determination of whether a GWS

supplier obtains water from a hydrogeologically sensitive setting.

BOARD NOTE:  This definition

derives from 40 CFR 141.400(c)(5).

"Inactivation

ratio" or "Ai" means the ratio:

Ai = CT

calc

/CT

99.9

The sum of the

inactivation ratios, or "total inactivation ratio" (B), is calculated

by adding together the inactivation ratio for each disinfection sequence:

B = Σ(Ai)

A total

inactivation ratio equal to or greater than 1.0 assumedly provides a 3-log

inactivation of Giardia lamblia cysts.

BOARD NOTE:  This

definition derives from the definition of "CT" in 40 CFR

141.2.

"Initial

compliance period" means the three-year compliance period that began

January 1, 1993, except for the MCLs for dichloromethane,

1,2,4-trichlorobenzene, 1,1,2-trichloroethane, benzo(a)pyrene, dalapon,

di(2-ethylhexyl)adipate, di(2-ethylhexyl)phthalate, dinoseb, diquat, endothall,

endrin, glyphosate, hexachlorobenzene, hexachlorocyclopentadiene, oxamyl,

picloram, simazine, 2,3,7,8-TCDD, antimony, beryllium, cyanide, nickel, and

thallium, as they apply to a supplier whose system has fewer than 150 service

connections, for which "initial compliance period" means the

three-year compliance period that began January 1, 1996.

"Initial distribution system

evaluation" or "IDSE" means the evaluation, performed by the

supplier under Section 611.921(c), to determine the locations in a distribution

system that are representative of high TTHM and HAA5 concentrations throughout

the distribution system.  An IDSE is used in conjunction with, but is distinct

from, the compliance monitoring undertaken to identify and select monitoring

locations used to determine compliance with Subpart I.

BOARD NOTE:  This definition

derives from 40 CFR 141.601(c)

to determine the locations in a distribution

system that are representative of high TTHM and HAA5 concentrations throughout

the distribution system.  An IDSE is used in conjunction with, but is distinct

from, the compliance monitoring undertaken to identify and select monitoring

locations used to determine compliance with Subpart I.

BOARD NOTE:  This definition

derives from 40 CFR 141.601(c).

"Inorganic

contaminants" or "IOCs" refers to that group of contaminants

designated as such in USEPA regulatory discussions and guidance documents.

IOCs include antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium,

cyanide, mercury, nickel, nitrate, nitrite, selenium, and thallium.

BOARD NOTE:  This

definition derives from 40 CFR 141.23(a)(4).

"ℓ"

or "L" means liter.

"Lake or reservoir"

means a natural or man made basin or hollow on the Earth's surface in which

water collects or is stored that may or may not have a current or single

direction of flow.

"Legionella"

means a genus of bacteria, some species of which have caused a type of

pneumonia called Legionnaires Disease.

"Level 1 assessment" means

an evaluation to identify the possible presence of sanitary defects, defects in

distribution system coliform monitoring practices, and (when possible) the

likely reason that the system triggered the assessment.  The system owner or

operator conducts a Level 1 assessment.  Minimum elements include review and

identification of atypical events that could affect distributed water quality

or indicate that distributed water quality is impaired; changes in distribution

system maintenance and operation that could affect distributed water quality

(including water storage); source and treatment considerations that bear on

distributed water quality, if appropriate (e.g., whether a groundwater system

is disinfected); existing water quality monitoring data; and inadequacies in

sample sites, sampling protocol, and sample processing

mpaired; changes in distribution

system maintenance and operation that could affect distributed water quality

(including water storage); source and treatment considerations that bear on

distributed water quality, if appropriate (e.g., whether a groundwater system

is disinfected); existing water quality monitoring data; and inadequacies in

sample sites, sampling protocol, and sample processing.  The supplier must

conduct the assessment consistent with any Agency-imposed permit conditions

that tailor specific assessment elements with respect to the size and type of

the system and the size, type, and characteristics of the distribution system.

"Level 2 assessment" means

an evaluation to identify the possible presence of sanitary defects, defects in

distribution system coliform monitoring practices, and (when possible) the

likely reason that the system triggered the assessment.  A Level 2 assessment

provides a more detailed examination of the system (including the system's

monitoring and operational practices) than does a Level 1 assessment through

the use of more comprehensive investigation and review of available

information, additional internal and external resources, and other relevant

practices.  A person approved by the Agency in a SEP conducts a Level 2

assessment, and that person may include the system operator.  Minimum elements

include review and identification of atypical events that could affect

distributed water quality or indicate that distributed water quality is

impaired; changes in distribution system maintenance and operation that could

affect distributed water quality (including water storage); source and

treatment considerations that bear on distributed water quality, if appropriate

(e.g., whether a groundwater system is disinfected); existing water quality

monitoring data; and inadequacies in sample sites, sampling protocol, and

sample processing

mpaired; changes in distribution system maintenance and operation that could

affect distributed water quality (including water storage); source and

treatment considerations that bear on distributed water quality, if appropriate

(e.g., whether a groundwater system is disinfected); existing water quality

monitoring data; and inadequacies in sample sites, sampling protocol, and

sample processing.  The person conducting the Level 2 assessment and the supplier

must conduct the assessment consistent with any Agency-imposed permit

conditions that tailor specific assessment elements with respect to the size

and type of the system and the size, type, and characteristics of the

distribution system.  The person conducting the Level 2 assessment and the supplier

must comply with any expedited actions or additional actions the SEP requires in

the instance of an E. coli

MCL violation.

"Locational running annual

average" or "LRAA" means the average of sample analytical

results for samples taken at a particular monitoring location during the

previous four calendar quarters.

"Man-made

beta particle and photon emitters" means all radionuclides emitting beta

particles or photons listed in NBS Handbook 69 (63), incorporated by reference

in Section 611.102, except the daughter products of thorium-232, uranium-235

and uranium-238.

BOARD NOTE:

The USEPA-recognized naturally occurring daughter products are alpha emitters (

211,212

Bi,

231

Pa,

210,212,214,215,216,218

Po,

223,224,226

Ra,

219,220,222

Rn,

227,228,230

Th,

234

U ) and beta

emitters (

227,228

Ac,

210,212,214

Bi,

234

Pa,

210,211,212,214

Pb,

228

Ra,

231,234

Th, and

207,208

TI.  See 56 Fed. Reg.

33050, 33063-65 (July 18, 1991).

"Maximum

contaminant level" or "MCL" means the maximum permissible concentration

of a contaminant in water a supplier delivers to any user of its PWS

210,212,214,215,216,218

Po,

223,224,226

Ra,

219,220,222

Rn,

227,228,230

Th,

234

U ) and beta

emitters (

227,228

Ac,

210,212,214

Bi,

234

Pa,

210,211,212,214

Pb,

228

Ra,

231,234

Th, and

207,208

TI.  See 56 Fed. Reg.

33050, 33063-65 (July 18, 1991).

"Maximum

contaminant level" or "MCL" means the maximum permissible concentration

of a contaminant in water a supplier delivers to any user of its PWS. (See

Section 611.121.)

"Maximum

contaminant level goal" or "MCLG" means the maximum concentration

of a contaminant in drinking water that USEPA determined will cause no known or

anticipated adverse effect on the health of persons, allowing an adequate

margin of safety.  MCLGs are nonenforceable health goals.

BOARD NOTE:  The

federal MCLGs are outside the scope of the Board's identical-in-substance

mandate under Section 17.5 of the Act.

"Maximum

residual disinfectant level" or "MRDL" means the maximum

permissible concentration of a disinfectant added for water treatment that USEPA

determined a supplier may add and may not exceed at the consumer's tap without

an unacceptable risk of adverse health effects.  MRDLs are enforceable in the

same manner as are MCLs.  (See Section 611.313 and Section 611.383.)

"Maximum

residual disinfectant level goal" or "MRDLG" means the maximum concentration

of a disinfectant that USEPA determined a supplier may add for water treatment that

would not cause any known or anticipated adverse effect on the health of

persons, allowing an adequate margin of safety.  MRDLGs are nonenforceable

health goals and do not reflect the benefit of the addition of the chemical for

control of waterborne microbial contaminants.

"Maximum

total trihalomethane potential" or "MTP" means the maximum

concentration of total trihalomethanes (TTHMs) produced in a given water

containing a disinfectant residual after seven days at a temperature of 25° C

or above

in of safety.  MRDLGs are nonenforceable

health goals and do not reflect the benefit of the addition of the chemical for

control of waterborne microbial contaminants.

"Maximum

total trihalomethane potential" or "MTP" means the maximum

concentration of total trihalomethanes (TTHMs) produced in a given water

containing a disinfectant residual after seven days at a temperature of 25° C

or above.

"Membrane filtration"

means a pressure- or vacuum-driven separation process in which particulate

matter larger than one micrometer is rejected by an engineered barrier,

primarily through a size exclusion mechanism, having a measurable removal

efficiency of a target organism that is verifiable using a direct integrity

test.  This definition includes the common membrane technologies of

microfiltration, ultrafiltration, nanofiltration, and reverse osmosis.

"Method

detection limit" or "MDL" means the minimum concentration of a

substance that analysis can measure and report with 99 percent confidence that

the analyte concentration is greater than zero, from analysis of a sample in a

given matrix containing the analyte.

"MFL"

means millions of fibers per liter larger than 10 micrometers.

BOARD NOTE:  This

definition derives from 40 CFR 141.23(a)(4)(i).

"mg"

means milligrams (1/1000 of a gram).

"µg" means micrograms

(1/1,000,000 of a gram).

"mg/ℓ"

or "mg/L"

means milligrams per

liter.

"µg/ℓ"

or "µg/L"

means micrograms per

liter.

"Mixed

system" means a PWS using both groundwater and surface water sources.

BOARD NOTE:  Derived

from 40 CFR 141.400(b).

"MUG"

means 4-methyl-umbelliferyl-beta-d-glucuronide(IUPAC name:

(2S,3S,4S,5R,6S)-3,4,5-trihydroxy-6-((4-methyl-2-oxo-2Hchromen-7-yl)oxy)tetrahydro-2H-pyran-2-caboxylic

acid; CAS no. 881005-91-0).

"Near the

first service connection" means at one of the 20 percent of all service

connections in the entire system that are nearest the PWS treatment facility,

as measured by water transport time within the distribution system

eryl-beta-d-glucuronide(IUPAC name:

(2S,3S,4S,5R,6S)-3,4,5-trihydroxy-6-((4-methyl-2-oxo-2Hchromen-7-yl)oxy)tetrahydro-2H-pyran-2-caboxylic

acid; CAS no. 881005-91-0).

"Near the

first service connection" means at one of the 20 percent of all service

connections in the entire system that are nearest the PWS treatment facility,

as measured by water transport time within the distribution system.

"nm"

means nanometer (1/1,000,000,000 of a meter).

"Non-community

water system" or "NCWS" or "non-CWS" means a PWS that

is not a CWS.  A non-CWS is either a "transient non-community water system

(TWS)" or NTNCWS.

"Non-transient,

non-community water system" or "NTNCWS" means a PWS that is not

a CWS and that regularly serves at least 25 of the same persons over six months

per year.

"NPDWR"

means "national primary drinking water regulation".

"NTU"

means "nephelometric turbidity units".

"P-A

Coliform Test" means "Presence-Absence Coliform Test".

"Paired

sample" means two samples of water for total organic carbon (TOC). One

sample is of raw water the supplier takes prior to any treatment.  The supplier

takes the other sample after the point of combined filter effluent

representative of the treated water.  The supplier takes these samples at the

same time.  (See Section 611.382.)

"Performance

evaluation sample" or "PE sample" means a reference sample the

Agency provides a laboratory for demonstrating that the laboratory can

successfully analyze the sample within limits of performance the Agency

specifies.  For bacteriological laboratories, Public Health provides the

sample.  For radiological laboratories, the Illinois Emergency Management

Agency provides the sample.  The laboratory does not know the true value of the

concentration of the reference material at the time of analysis.

"Person"

means an individual, corporation, company, association, partnership, state,

unit of local government, or federal agency

ogical laboratories, Public Health provides the

sample.  For radiological laboratories, the Illinois Emergency Management

Agency provides the sample.  The laboratory does not know the true value of the

concentration of the reference material at the time of analysis.

"Person"

means an individual, corporation, company, association, partnership, state,

unit of local government, or federal agency.

"PFBS" means Chemical

Abstract Service registration number 45187-15-3, chemical formula

C

4

F

9

SO

3

-,

perfluorobutane sulfonate, along with its conjugate acid and any salts,

derivatives, isomers, or combinations thereof.

"PFHxS" means Chemical

Abstract Service registration number 108427-53-8, chemical formula

C

6

F

13

SO

3

-,

perfluorohexane sulfonate, along with its conjugate acid and any salts,

derivatives, isomers, or combinations thereof.

"PFNA" means Chemical

Abstract Service registration number 72007-68-2, chemical formula

C

9

F

17

O

2

-,

perfluorononanoate, along with its conjugate acid and any salts, derivatives,

isomers, or combinations thereof.

"PFOA" means Chemical

Abstract Service registration number 45285-51-6, chemical formula

C

8

F

15

O

2

-,

perfluorooctanoate, along with its conjugate acid and any salts, derivatives,

isomers, or combinations thereof.

"PFOS" means Chemical

Abstract Service registration number 45298–90–6, chemical formula C

8

F

17

SO

3

-, perfluorooctanesulfonate, along with its conjugate

acid and any salts, derivatives, isomers, or combinations thereof.

"Phase

I" refers to that group of chemical contaminants and the accompanying

regulations promulgated by USEPA on July 8, 1987, at 52 Fed. Reg. 25712.

"Phase

II" refers to that group of chemical contaminants and the accompanying

regulations promulgated by USEPA on January 30, 1991, at 56 Fed. Reg. 3578.

"Phase

IIB" refers to that group of chemical contaminants and the accompanying

regulations promulgated by USEPA on July 1, 1991, at 56 Fed. Reg. 30266

the accompanying

regulations promulgated by USEPA on July 8, 1987, at 52 Fed. Reg. 25712.

"Phase

II" refers to that group of chemical contaminants and the accompanying

regulations promulgated by USEPA on January 30, 1991, at 56 Fed. Reg. 3578.

"Phase

IIB" refers to that group of chemical contaminants and the accompanying

regulations promulgated by USEPA on July 1, 1991, at 56 Fed. Reg. 30266.

"Phase

V" refers to that group of chemical contaminants promulgated by USEPA on

July 17, 1992, at 57 Fed. Reg. 31776.

"Picocurie"

or "pCi" means the quantity of radioactive material producing 2.22

nuclear transformations per minute.

"Plant intake" means the

works or structures at the head of a conduit diverting water from a source

(e.g., a river or lake) into the treatment plant.

"Point of

disinfectant application" is the point where a supplier applies the

disinfectant and downstream of where the water is not subject to

recontamination by surface water runoff.

"Point-of-entry

treatment device" or "POE device" is a treatment device a

consumer applies to the drinking water entering a house or building to reduce

contaminants in the drinking water distributed throughout the house or

building.

"Point-of-use treatment

device", "point-of-use device", or "POU" is a water treatment

device a consumer applies to a single tap to reduce contaminants in drinking water

at that tap. Under Subpart G, a manufacturer, importer, or accredited

third-party certifying body must certify a POU device as complying with

NSF/ANSI 53 or 58 as in effect on the date of manufacture or import to satisfy

the rule.

BOARD

NOTE:  NSF/ANSI 53 is the health-based standard for lead and several other

contaminants for water filter devices, including tap filter-type treatment

devices.  Identifying a device as certified under NSF/ANSI 53 at the time of

purchase is possible.  NSF maintains an on-line list of certified devices at

info.nsf.org/Certified/dwtu/listings_leadreduction.asp

r import to satisfy

the rule.

BOARD

NOTE:  NSF/ANSI 53 is the health-based standard for lead and several other

contaminants for water filter devices, including tap filter-type treatment

devices.  Identifying a device as certified under NSF/ANSI 53 at the time of

purchase is possible.  NSF maintains an on-line list of certified devices at

info.nsf.org/Certified/dwtu/listings_leadreduction.asp.  See the definition of "accredited

third-party certifying body" in 35 Ill. Adm. Code 611.126(b) relating to

NSF/ANSI 372.

"Presedimentation" means

a preliminary treatment process a supplier uses to remove gravel, sand, and

other particulate material from the source water through settling before the

water enters the primary clarification and filtration processes in a treatment

plant.

"Public

Health" or "DPH" means the Illinois Department of Public Health.

BOARD NOTE:

See the definition of

"Agency"

in this Section

.

"Public

water system" or "PWS" means a system providing water to the

public for human consumption through pipes or other constructed conveyances if the

system has at least 15 service connections or regularly serves an average of at

least 25 individuals daily at least 60 days out of the year.  A PWS is either a

CWS or non-CWS.  A PWS does not include any special irrigation district.  "PWS"

includes certain facilities:

Any

collection, treatment, storage, and distribution facilities under control of

the PWS operator that the operator uses in connection with the system; and

Any collection

or pretreatment storage facilities not under control of the PWS operator that

the operator uses primarily in connection with the system.

BOARD NOTE:  SDWA

and USEPA rules use "public water system".  The Act uses "public

water supply".  The Board intends that "public water supply"

means the same as "public water system"

and

both terms refer both to the facilities providing water and the persons owning

and operating those facilities

der control of the PWS operator that

the operator uses primarily in connection with the system.

BOARD NOTE:  SDWA

and USEPA rules use "public water system".  The Act uses "public

water supply".  The Board intends that "public water supply"

means the same as "public water system"

and

both terms refer both to the facilities providing water and the persons owning

and operating those facilities

.

"Radioactive

contaminants" means those contaminants for which Section 611.330 imposes

an MCL.  "Radioactive contaminants" include radium-226 and -228, tritium,

strontium-89, strontium-90, iodine-131, cesium-134, uranium, gross alpha

emitters, gross beta emitters, photon emitters, and other nuclides emitting

energetic nuclear particles or photons.

BOARD NOTE:  This

definition derives from Table C in 40 CFR 141.25(c), 141.66, appendix A to

subpart O, and appendices A and B to subpart Q of 40 CFR 141.

"Reliably

and consistently below the MCL" for a contaminant means an Agency determination

based on analytical results following the initial detection of a contaminant to

determine the qualitative condition of water from an individual sampling point

or source.  The Agency must base this determination on the consistency of

analytical results, the degree below the MCL, the susceptibility of source

water to variation, and other vulnerability factors pertinent to the detected contaminant

that may influence the quality of water.

BOARD NOTE:  This

definition derives from 40 CFR 141.23(b)(9), (c)(8), (d)(2), and (e)(3) and

141.24(f)(11)(ii), and 141.24(f)(11)(iii), (f)(12), (h)(6)(ii), and (h)(8).

"Rem"

means the unit of dose equivalent from ionizing radiation to the total body or

any internal organ or organ system.  A "millirem (mrem)" is 1/1000 of

a rem.

"Repeat

compliance period" means a compliance period that begins after the initial

compliance period

rom 40 CFR 141.23(b)(9), (c)(8), (d)(2), and (e)(3) and

141.24(f)(11)(ii), and 141.24(f)(11)(iii), (f)(12), (h)(6)(ii), and (h)(8).

"Rem"

means the unit of dose equivalent from ionizing radiation to the total body or

any internal organ or organ system.  A "millirem (mrem)" is 1/1000 of

a rem.

"Repeat

compliance period" means a compliance period that begins after the initial

compliance period.

"Representative"

means that a sample reflects the quality of water a supplier delivers to

consumers under conditions when the supplier uses all raw water sources it

requires to supply water under normal use conditions and all treatment properly

operates.

"Residual

disinfectant concentration", "RDC", or the variable "C"

in CT calculations means the concentration of disinfectant measured in mg/L in

a representative sample of water.  For purposes of the requirement of Section

611.241(d) of maintaining a detectable RDC in the distribution system,

"RDC" means a residual of free or combined chlorine.

"Safe

Drinking Water Act" or "SDWA" means the Public Health Service

Act, as amended by the Safe Drinking Water Act, Pub. L. 93-523, 42 U.S.C. 300f

et seq.

"Sanitary defect" means

a defect that could provide a pathway of entry for microbial contamination of a

supplier's distribution system or that indicates a failure or imminent failure

in an existing barrier to microbial contamination.

"Sanitary

survey" means an onsite review of the delineated WHPAs (identifying

sources of contamination within the WHPAs and evaluations or the hydrogeologic

sensitivity of the delineated WHPAs the Agency conducted under source water

assessments or utilizing other relevant information if available), facilities,

equipment, operation, maintenance, and monitoring compliance of a PWS supplier

to evaluate the adequacy of the system, its sources, and operations for the

production and distribution of safe drinking water.

BOARD NOTE:  This definition

derives from 40 CFR 141.2 and 40 CFR 142.16(o)(2)

y conducted under source water

assessments or utilizing other relevant information if available), facilities,

equipment, operation, maintenance, and monitoring compliance of a PWS supplier

to evaluate the adequacy of the system, its sources, and operations for the

production and distribution of safe drinking water.

BOARD NOTE:  This definition

derives from 40 CFR 141.2 and 40 CFR 142.16(o)(2).

"Seasonal system" means

a non-CWS not operating as a PWS on a year-round basis and starting up and shutting

down at the beginning and end of each operating season.

"Sedimentation"

means a process for removing solids before filtration by gravity or separation.

"SEP"

means special exception permit the Agency issued under 35 Ill. Adm. Code 602.600.

"Service

connection", as used in the definition of PWS, does not include a

connection to a system delivering water by a constructed conveyance other than

a pipe if any of certain conditions exist:

Consumers use the water exclusively for purposes other than residential

use (consisting of drinking, bathing, and cooking, or other similar uses);

The Agency issues a SEP determining that the supplier provides alternative

water for residential use or similar uses for drinking and cooking to achieve

the equivalent level of public health protection to that the applicable

national primary drinking water regulations provide; or

The Agency issues a SEP determining that the water provided for

residential use or similar uses for drinking, cooking, and bathing is centrally

treated or treated at the point of entry by the provider, a pass-through

entity, or the user to achieve the equivalent level of public health protection

to that the applicable national primary drinking water regulations provide.

BOARD NOTE:

See SDWA sections 1401(4)(B)(i)(II) and (4)(B)(i)(III) (42 U.S.C.

300f(4)(B)(i)(II) and (4)(B)(i)(III)).

"Significant deficiency"

means a deficiency the Agency identifies in a groundwater system under Section

611.803

-through

entity, or the user to achieve the equivalent level of public health protection

to that the applicable national primary drinking water regulations provide.

BOARD NOTE:

See SDWA sections 1401(4)(B)(i)(II) and (4)(B)(i)(III) (42 U.S.C.

300f(4)(B)(i)(II) and (4)(B)(i)(III)).

"Significant deficiency"

means a deficiency the Agency identifies in a groundwater system under Section

611.803.  A significant deficiency might include a defect in system design,

operation, or maintenance or a failure or malfunction of the sources,

treatment, storage, or distribution system that the Agency determines causes or

could cause introduction of contamination into the water the supplier delivers

to consumers.

BOARD NOTE:  This definition

derives from 40 CFR 142.16(o)(2)(iv).  The Agency must submit to USEPA a

definition and description of at least one significant deficiency in each of

the eight sanitary survey elements listed in Section 611.801(c) as part of the

federal primacy requirements.  The Board added the general description of what

a significant deficiency might include in non-limiting terms, not intending to

limit Agency discretion submitting what USEPA requires.  What the Agency submits

to USEPA cannot provide a definition within the Board regulations without Board

rulemaking action.

"Slow

sand filtration" means a process involving passing raw water through a bed

of sand at low velocity (generally less than 0.4 meters per hour (m/h))

resulting in physical and biological mechanisms substantially removing

particulate material.

"SOC"

or "Synthetic organic chemical contaminant" refers to that group of

contaminants designated as "SOCs" in Section 611.311(c).

"Source"

means a well, reservoir, or other source of raw water

ing passing raw water through a bed

of sand at low velocity (generally less than 0.4 meters per hour (m/h))

resulting in physical and biological mechanisms substantially removing

particulate material.

"SOC"

or "Synthetic organic chemical contaminant" refers to that group of

contaminants designated as "SOCs" in Section 611.311(c).

"Source"

means a well, reservoir, or other source of raw water.

"Special

irrigation district" means an irrigation district in existence prior to

May 18, 1994 that provides primarily agricultural service through a piped water

system with only incidental residential use or similar use if the Agency issues

a SEP making either of two determinations:

The Agency determines that the supplier or another person provides alternative

water for residential use or similar uses for drinking or cooking to achieve

the equivalent level of public health protection to that the applicable

national primary drinking water regulations provide; or

The Agency issues a SEP determining that the water provided for

residential use or similar uses for drinking, cooking, and bathing is centrally

treated or treated at the point of entry by the provider, a pass-through

entity, or the user to protect public health at a level equivalent to that the

applicable NPDWRs provide.

BOARD NOTE:  This

definition derives from 40 CFR 141.2 and sections 1401(4)(B)(i)(II) and

(4)(B)(i)(III) of SDWA (42 U.S.C. 300f(4)(B)(i)(II) and (4)(B)(i)(III)).

"Standard monitoring"

means the monitoring the supplier performs under Section 611.921(a) and (b) at

various specified locations in its distribution system, including near entry

points, at points representing the average residence time in its distribution

system and at points in its distribution system representing high TTHM and HAA5

concentrations throughout the system.

BOARD NOTE:  This definition

derives from 40 CFR 141.601(a) and (b)

supplier performs under Section 611.921(a) and (b) at

various specified locations in its distribution system, including near entry

points, at points representing the average residence time in its distribution

system and at points in its distribution system representing high TTHM and HAA5

concentrations throughout the system.

BOARD NOTE:  This definition

derives from 40 CFR 141.601(a) and (b).

"Standard

sample" means the aliquot of finished drinking water the supplier or

laboratory examines for the presence of coliform bacteria.

"State-only MCL" means

one of the inorganic maximum contaminant levels (MCLs) in Section 611.300 or

organic MCLs in Section 611.310.

BOARD NOTE:  State-only MCLs are

those derived prior to the implementation of the USEPA "Phase II"

regulations.  The Section 611.640 definition of this term, applying only to

Subpart O, does not include the Section 611.300 inorganic MCLs.

"Subpart

B system" means a PWS using surface water or groundwater under the direct

influence of surface water as a source that is subject to Subpart B and the

analytical and monitoring requirements of Sections 611.531, 611.532, and 611.533

and Appendices B and C.

BOARD NOTE:

USEPA rules define these "subpart H systems".

"Subpart I compliance

monitoring" means monitoring required under Subpart I to demonstrate

compliance with requirements for disinfectant residuals, disinfection

byproducts, and disinfection byproduct precursors.

BOARD NOTE:  The equivalent to

Subpart I is subpart L of 40 CFR 141 under USEPA's rules.

"Subpart Y compliance

monitoring" or "Subpart Y monitoring" means monitoring Subpart Y

requires to demonstrate compliance with Stage 2 requirements for disinfection

byproducts.

BOARD NOTE:  The equivalent to

Subpart Y is subpart V of 40 CFR 141 under USEPA's rules.

"Supplier

" means any person owning or operating a PWS.  This term includes the

"official custodian"

FR 141 under USEPA's rules.

"Subpart Y compliance

monitoring" or "Subpart Y monitoring" means monitoring Subpart Y

requires to demonstrate compliance with Stage 2 requirements for disinfection

byproducts.

BOARD NOTE:  The equivalent to

Subpart Y is subpart V of 40 CFR 141 under USEPA's rules.

"Supplier

" means any person owning or operating a PWS.  This term includes the

"official custodian". Under several rules, “supplier” includes a

person performing a compliance-related activity on behalf of the owner or

operator (e.g., a laboratory performing analyses, an engineer performing an

assessment, design review, system evaluation, or other work, or a property

owner or occupant sampling a tap).

"Surface

water" means any water that is open to the atmosphere and subject to

surface runoff.

"SUVA"

means specific ultraviolet absorption at 254 nanometers (nm), an indicator of

the humic content of water.  "SUVA" is a sample's ultraviolet

absorption at a wavelength of 254 nm (UV

254

)

(in m

-1

)

divided by its concentration of dissolved organic carbon (in mg/L).

"SWS"

means "surface water system", a PWS using only surface water sources,

including groundwater under the direct influence of surface water.

BOARD NOTE:  This

definition derives from 40 CFR 141.23(a)(2) note, 141.24(h)(2) note, 141.70(a),

and 141.88(a)(1)(ii) note.

"System-specific study plan"

means the plan a supplier submits to the Agency under Section 611.922 for

studying the occurrence of TTHM and HAA5 in the supplier's distribution system

based on either monitoring results or modelling of the system.

BOARD NOTE:  This definition

derives from 40 CFR 141.602.

"System

with a single service connection" means a system supplying drinking water

to consumers via a single service line.

"Too

numerous to count" means that the total number of bacterial colonies

exceeds 200 on a 47-mm diameter membrane filter used for coliform detection

m

based on either monitoring results or modelling of the system.

BOARD NOTE:  This definition

derives from 40 CFR 141.602.

"System

with a single service connection" means a system supplying drinking water

to consumers via a single service line.

"Too

numerous to count" means that the total number of bacterial colonies

exceeds 200 on a 47-mm diameter membrane filter used for coliform detection.

"Total

organic carbon" or "TOC" means total organic carbon (in mg/L)

measured using heat, oxygen, ultraviolet irradiation, chemical oxidants, or

combinations of these to oxidize organic carbon to carbon dioxide, rounded to

two significant figures.

"Total

trihalomethanes" or "TTHM" means the sum of the concentration of

trihalomethanes (THMs) in milligrams per liter (mg/L), rounded to two

significant figures.

BOARD NOTE:  The

definition of "trihalomethanes" lists the four compounds that USEPA

considers TTHMs.

"Transient,

non-community water system" or "transient non-CWS" means a

non-CWS not regularly serving at least 25 of the same persons over six months

of the year.

BOARD NOTE:

The federal regulations apply to all "public water systems", defined

as all systems having at least 15 service connections or regularly serving

water to at least 25 persons. (See 42 U.S.C. 300f(4).)  The Act mandates that

the Board and the Agency regulate "public water supplies", defined as

having at least 15 service connections or regularly serving 25 persons daily at

least 60 days per year.  (See Section 3.365 of the Act.)  The Department of

Public Health regulates transient non-CWSs.

"Treatment"

means any process changing the physical, chemical, microbiological, or

radiological properties of water that is under the control of the supplier and

is not a point-of-use treatment device or a point-of-entry treatment device.

Treatment includes aeration, coagulation, sedimentation, filtration, activated

carbon treatment, disinfection, or fluoridation

egulates transient non-CWSs.

"Treatment"

means any process changing the physical, chemical, microbiological, or

radiological properties of water that is under the control of the supplier and

is not a point-of-use treatment device or a point-of-entry treatment device.

Treatment includes aeration, coagulation, sedimentation, filtration, activated

carbon treatment, disinfection, or fluoridation.

"Trihalomethane"

or "THM" means one of four specific derivatives of methane in which halogens

substitute three of the four hydrogen atoms in the molecular structure.  There

are four THMs:

Trichloromethane

(chloroform),

Dibromochloromethane,

Bromodichloromethane,

and

Tribromomethane

(bromoform)

"Two-stage lime softening"

means a process in which adding chemical precipitant and precipitating hardness

occur in two distinct clarification process units in series prior to

filtration.

"USEPA"

means the U.S. Environmental Protection Agency.

"Uncovered

finished water storage facility" is a tank, reservoir, or other facility directly

open to the atmosphere a supplier uses to store water that will undergo no

further treatment to reduce microbial pathogens except residual disinfection.

"Very small system waiver"

means a conditional waiver from Subpart W available under Section 611.924 to a

supplier serving fewer than 500 persons that took TTHM and HAA5 samples under

Subpart I.

BOARD NOTE:  This definition

derives from 40 CFR 141.604.

"Virus"

means a virus of fecal origin that is infectious to humans by waterborne

transmission.

"VOC"

or "volatile organic chemical contaminant" refers to that group of

contaminants designated as "VOCs" in Section 611.311(a).

"Waterborne

disease outbreak" means a significant occurrence of acute infectious

illness epidemiologically associated with the ingestion of water from a PWS

that is deficient in treatment, as determined by an appropriate local or State

agency

rborne

transmission.

"VOC"

or "volatile organic chemical contaminant" refers to that group of

contaminants designated as "VOCs" in Section 611.311(a).

"Waterborne

disease outbreak" means a significant occurrence of acute infectious

illness epidemiologically associated with the ingestion of water from a PWS

that is deficient in treatment, as determined by an appropriate local or State

agency.

"Wellhead protection area"

or "WHPA" means the surface and subsurface recharge area surrounding

a CWS well or well field, delineated outside of any applicable setback zones (under

Section 17.1 of the Act) under Illinois' Wellhead Protection Program, through

which contaminants are reasonably likely to move toward the well or well field.

BOARD NOTE:  The Agency uses two

guidance documents for identification of WHPAs:

"Guidance Document for

Groundwater Protection Needs Assessments", Illinois Environmental

Protection Agency, Illinois State Water Survey, and Illinois State Geologic

Survey joint report, January 1995; and

"The Illinois Wellhead

Protection Program under Section 1428 of the Federal Safe Drinking Water Act",

Illinois Environmental Protection Agency, No. 22480, October 1992.

"Wellhead

protection program" means the Illinois wellhead protection program,

approved by USEPA under section 1428 of the SDWA, 42 U.S.C. 300h-7.

BOARD NOTE:  This

definition derives from 40 CFR 141.71(b).  The wellhead protection program

includes the "groundwater protection needs assessment" under Section

17.1 of the Act and 35 Ill. Adm. Code 615 through 617.

"Wholesale system" means

a PWS treating source water as necessary to produce finished water, delivering

some or all of that finished water to another PWS.  A wholesale system may deliver

water through a direct connection or through the distribution system of one or

more consecutive systems.

BOARD NOTE:  This Section

derives from 40 CFR 141.2 and other sources as noted.