(1) "Action level" is the concentration of
lead or copper in water which may determine the treatment requirements that a
water system is required to complete.
(2) "Bag Filters" are pressure-driven
separation devices that remove particulate matter larger than 1 micrometer
using an engineered porous filtration media. They are typically constructed on
a non-rigid fabric filtration media housed in a pressure vessel in which the
direction of flow is from the inside of the bag to outside.
(3) "Bank Filtration" is a water treatment
process that uses a well to recover surface water that has naturally
infiltrated into ground water through a river bed or bank(s). Infiltration is
typically enhanced by the hydraulic gradient imposed by nearby pumping water
supply or other wells.
(4)
"Benchmark" A disinfection benchmark is the lowest monthly average value of the
monthly logs of Garidia Lamblia inactivation.
(5) "Business Plan" means a document which
identifies source(s) of income or revenue sufficient to meet expenses over a
three (3) year period. The business plan will identify costs related to
retaining a certified operator, estimated annual infrastructure repair costs,
depreciation, facility maintenance fees, estimated annual monitoring costs,
estimated costs of providing public notices, estimated administrative costs,
and any and all other operational, treatment, and related costs (e.g. chemicals
and other supplies used to treat water, etc.). The business plan must include
the re-payment of borrowed and amortized funds.
(6) "Capacity Development Plan" means a
document(s) identifying what actions a public water system is taking or shall
take to become a "viable water system." Such plan shall include information
concerning retention of a Certified Operator in direct charge; system ownership
and accountability; staffing and organizational structure; fiscal management
and controls, source water assessment and protection plan; "business plan;" and
any and all other information identifying any further action that shall be
taken.
(7) "Cartridge filters" are
pressure-driven separation devices that remove particulate matter larger than 1
micrometer using an engineered porous filtration media. They are typically
constructed a rigid or semi-rigid self-supporting filter elements housed in
pressure vessels in which flow is from the outside of the cartridge to the
inside.
(9) "Coagulation" means a process using
coagulant chemicals and mixing by which colloidal and suspended materials are
destabilized and agglomerated into flocs.
(10) "Combined distribution system" is the
interconnected distribution system consisting of the distribution systems of
wholesale systems and of the consecutive systems that receive finished
water.
(11) "Community water
system" means a public water system which serves at least 15 service
connections used by year round residents or regularly serves at least 25 year
round residents.
(12) "Compliance
cycle" means the nine year calendar year cycle during which public water
systems must monitor for certain contaminants. Each compliance cycle consists
of three three year compliance periods. The first calendar year cycle begins
January 1, 1993 and ends December 31, 2001; the second begins January 1, 2002
and ends December 31, 2010; the third begins January 1, 2011 and ends December
31, 2019.
(13) "Compliance period"
means a three year calendar year period within a compliance cycle. Each
compliance cycle has three three year compliance periods. Within the first
compliance cycle, the first compliance period runs from January 1, 1993 to
December 31, 1995; the second from January 1, 1996 to December 31, 1998; the
third from January 1, 1999 to December 31, 2001.
(14) "Comprehensive performance evaluation
(CPE)" is a thorough review and analysis of a treatment plant's performance
based capabilities and associated administrative, operation and maintenance
practices. It is conducted to identify factors that may be adversely impacting
a plant's capability to achieve compliance and emphasizes approaches that can
be implemented without significant capital improvements. For purposes of
compliance, the comprehensive performance evaluation must consist of at least
the following components: assessment of plant performance; evaluation of major
unit processes; identification and prioritization of performance limiting
factors; assessment of the applicability of comprehensive technical assistance;
and preparation of a CPE report.
(15) "Confluent growth" means a continuous
bacterial growth covering the entire filtration area of a membrane filter, or a
portion thereof, in which bacterial colonies are not discrete.
(16) "Connection" means the point at which
there is a meter or service tap if no meter is present.
(17) "Consecutive system is a public water
system that receives some or all of its finished water from one or more
wholesale systems. Delivery may be through a direct connection or through the
distribution system of one or more consecutive systems.
(18) "Contaminant" means any physical,
chemical, biological, or radiological substance or matter in water.
(19) "Conventional filtration treatment"
means a series of processes including coagulation, flocculation, sedimentation,
and filtration resulting in substantial particulate removal.
(20) "Corrosion inhibitor" means a substance
capable of reducing the corrosivity of water toward metal plumbing materials,
especially lead and copper, by forming a protective film on the interior
surface of those materials.
(21)
"CT" or "CTcalc" is the product of "residual disinfectant concentration" (C) in
mg/1 determined before or at the first customer, and the corresponding
"disinfectant contact time" (T) in minutes, i.e., "C" x "T". If a public water
system 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 public
water system must determine the residual disinfectant concentration of each
disinfection sequence and corresponding contact time before any subsequent
disinfection application point(s). "CT99.9" is the CT value required for 99.9
percent (3 log) inactivation of Giardia lamblia cysts. CT99.9 for a variety of
disinfectants and conditions appear in tables 1.1 through 1.6, 2.1, and 3.1 of
part (5)(b)3. of Rule
0400-45-01-.31.
Click to view
Image
is the inactivation ratio. The sum of the
inactivation ratios, or total inactivation ratio shown as
Click to view
Image
is calculated by adding together the inactivation
ratio for each disinfection sequence. A total inactivation ratio equal to or
greater than 1.0 is assumed to provide a 3 log inactivation of Giardia lamblia
cyst. Disinfectant concentrations must be determined by tracer studies or an
equivalent demonstration approved by the Department.
(22) "Department" when used in these rules
means the Division of Water Resources, Tennessee Department of Environment and
Conservation, or one of the Division's field offices.
(23) "Diatomaceous earth filtration" means a
process resulting in substantial particulate removal in which (1) a precoat
cake of diatomaceous earth filter media is deposited on a support membrane
(septum), and (2) while the water is filtered by passing through the cake on
the septum, additional filter media known as body feed is continuously added to
the feed water to maintain the permeability of the filter cake.
(24) "Direct filtration" means a series of
processes including coagulation and filtration but excluding sedimentation
resulting in substantial particulate removal.
(25) "Disinfectant" means any oxidant,
including but not limited to 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.
(26) "Disinfectant contact time" ("T" in CT
calculations) means the time in minutes that it takes for water to move from
the point of disinfectant application or the previous point of disinfectant
residual measurement to a point before or at the point where residual
disinfectant concentration ("C") is measured. Where only one "C" is measured,
"T" is the time in minutes that it takes for water to move from the point of
disinfectant application to a point before or at where residual disinfectant
concentration ("C") is measured. Where more than one "C" is measured, "T" is
(a) for the first measurement of "C", the time in minutes that it takes for
water to move from the first or only point of disinfectant application to a
point before or at the point where the first "C" is measured and (b) for
subsequent measurements of "C", the time in minutes that it takes for water to
move from the previous "C" measurement point to the "C" measurement point for
which the particular "T" is being calculated. Disinfectant contact time in
pipelines must be calculated based on "plug flow" by dividing the internal
volume of the pipe by the maximum hourly flow rate through that pipe.
Disinfectant contact time within mixing basins and storage reservoirs must be
determined by tracer studies or an equivalent demonstration.
(27) "Disinfection" means a process which
inactivates pathogenic organisms in water by chemical oxidants or equivalent
agents.
(28) "Disinfection profile"
is a summary of daily Giardia lamblia inactivation through the treatment plant.
The procedure for developing a disinfection profile is contained in
40 CFR
141.172.
(29) "Distribution System" means all water
lines up to the point of a meter. For unmetered systems distribution system
includes all lines up to the customer's service tap.
(30) "Domestic or other non distribution
system plumbing problem" means a coliform contamination problem in a public
water system with more than one service connection that is limited to the
specific service connection from which the coliform positive sample was
taken.
(31) "Dose Equivalent" means
the product of the absorbed dose from ionizing radiation and such factors as
account for differences in biological effectiveness due to the type of
radiation and its distribution in the body as specified by the International
Commission on Radiological Units and Measurements (ICRU).
(32) "Dual sample set" is a set of two
samples collected at the same time and same location, with one sample analyzed
for TTHM and the other sample analyzed for HAA5. Dual sample sets are collected
for the purposes of conducting an IDSE under the provisions of Rule
0400-45-01-.37
and determining compliance with the TTHM and HAA5 MCLs under the provisions of
Rule
0400-45-01-.38.
(33) "Effective corrosion inhibitor residual"
for the purpose of the lead and copper rules only, means a concentration
sufficient to form a passivating film on the interior walls of a
pipe.
(34) "Engineer" means the
person or firm who designed the public water system and conceived, developed,
executed or supervised the preparation of the plan documents.
(35) "Enhanced coagulation" means the
addition of sufficient coagulant for improved removal of disinfection by
product precursors by conventional filtration treatment.
(36) "Enhanced softening" means the improved
removal of disinfection by product precursors by precipitative
softening.
(37) "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 to backwash inclusively, that includes an
assessment of filter performance while another filter is being
backwashed.
(38) "Filtration" means
a process for removing particulate matter from water by passage through porous
media.
(39) "Finished water" is
water that is introduced into the distribution system of a public water system
and is intended for distribution and consumption without further treatment,
except as treatment necessary to maintain water quality in the distribution
system (e.g., booster disinfection, addition of corrosion control
chemicals).
(40) "First draw
sample" means a one liter sample of tap water, for the purposes of the lead and
copper rules, that has been standing in plumbing pipes at least 6 hours and is
collected without flushing the tap.
(41) "Flooculation" means a process to
enhance agglomeration or collection of smaller floc particles into larger, more
easily settleable particles through gentle stirring by hydraulic or mechanical
means.
(42) "Flowing stream" is a
course of running water flowing in a definite channel.
(43) "GAC10" means granular activated carbon
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 used as best available technology for
compliance with disinfection byproducts shall be 120 days.
(44) "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.
(45) "Gross Alpha Particle Activity" means
the total radioactivity due to alpha particle emission as inferred from
measurements on a dry sample.
(46)
"Gross Beta Particle Activity" means the total radioactivity due to beta
particle emission as inferred from measurements on a dry sample.
(47) "Ground water under the direct influence
of surface water" means any water beneath the surface of the ground 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 which closely correlate to climatological or
surface water conditions. Direct influence must be determined for individual
sources in accordance with criteria established by the Department. The
Department determination of direct influence may be based on site specific
measurements of water quality and/or documentation of well construction
characteristics and geology with field evaluation.
(48) "Haloacetic acids (five) (HAA5)" mean
the sum of the concentrations in milligrams per liter of the haloacetic acid
compounds (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid,
monobromoacetic acid, and dibromoacetic acid), rounded to two significant
figures after addition.
(49)
"Halogen" means one of the chemical elements chlorine, bromine or
iodine.
(50) "Human consumption"
means the use of water that involves any drinking or ingestion of the water by
humans, any human skin contact, or food preparation where the food is not
brought to boiling temperatures after contact with the water.
(51) "Initial compliance period" means the
first full three year compliance period which begins January 1, 1993. For
public water systems having fewer than 150 service connections initial
compliance period shall be January 2, 1996, for the following contaminants:
(a)
|
Antimony
|
(m)
|
endrin
|
(b)
|
Beryllium
|
(n)
|
glyphosate
|
(c)
|
Cyanide
|
(o)
|
oxamyl
|
(d)
|
Nickel
|
(p)
|
picloram
|
(e)
|
Thallium
|
(q)
|
simazine
|
(f)
|
dichloromethane
|
(r)
|
benzo(a)pyrene
|
(g)
|
1,2,4-trichlorobenzene
|
(s)
|
di(2ethylhexyl)adipate
|
(h)
|
1,1,2-trichloroethane
|
(t)
|
di(2ethylhexyl)phthalate
|
(i)
|
dalapon
|
(u)
|
hexachlorobenzene
|
(j)
|
dinoseb
|
(v)
|
hexachlorocyclopentadiene
|
(k)
|
diquat
|
(w)
|
2,3,7,8
TCDD
|
(l)
|
endothall
|
|
|
(52) "Lake/reservoir" refers to 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.
(53) "Large water system" for
the purpose of lead and copper rule, means a water system that serves more than
50,000 persons.
(54) "Lead service
line" means a service line made of lead which connects the water main to the
building inlet and any lead pigtail, gooseneck or other fitting which is
connected to such lead line.
(55)
"Legionella" means a genus of bacteria, some species of which have caused a
type of pneumonia called Legionnaires Disease.
(56) "Level 1 assessment" is 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. It is conducted by the system
operator or owner. Minimum elements include review and identification of
atypical events that could affect distributed water quality or indicate that
distributed water quality was 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, where appropriate (e.g., whether a ground water
system is disinfected); existing water quality monitoring data; and
inadequacies in sample sites, sampling protocol, and sample processing. The
system must conduct the assessment consistent with any Department directives
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.
(57) "Level 2 assessment"
is 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. It is conducted by an individual approved by the Department, which
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 was 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, where appropriate (e.g., whether a
ground water system is disinfected); existing water quality monitoring data;
and inadequacies in sample sites, sampling protocol, and sample processing. The
system must conduct the assessment consistent with any Department directives
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 system must comply with any expedited actions or additional actions
required by the Department in the case of an E. coli MCL violation.
(58) "Locational running annual average
(LRAA)" is the average of sample analytical results for samples taken at a
particular monitoring location during the previous four calendar
quarters.
(59) "Man-Made Beta
Particle and Photon Emitter" means all radionuclides emitting beta particles
and/or photons listed in "Maximum Permissible Body Burdens and Maximum
Permissible Concentration of Radionuclides in Air or Water for Occupational
Exposure, NBS Handbook 69", except the daughter products of thorium 232,
uranium 235 and uranium 238.
(60)
"Maximum contaminant level" or "MCL" means the maximum permissible level of a
contaminant in water which is delivered at the free flowing outlet of the
ultimate user of a public water system, except in the case of turbidity where
the maximum permissible level is measured at the point of entry to the
distribution system. Contaminants added to the water under circumstances
controlled by the user, except those resulting from corrosion of piping and
plumbing caused by water quality, are excluded from this definition.
(61) "Maximum contaminant level goal" or
"MCLG" means that the maximum level of the contaminant in drinking water at
which no known or anticipated adverse effect on the health of persons would
occur, and which allows an adequate margin of safety. Maximum contaminant level
goals are non-enforceable health goals.
(62) "Maximum residual disinfectant level
(MRDL)" means a level of a disinfectant added for water treatment that may not
be exceeded at the consumer's tap without an unacceptable possibility of
adverse health effects. For chlorine and chloramines, a PWS is in compliance
with the MRDL when the running annual average of monthly averages of samples
taken in the distribution system, computed quarterly, is less than or equal to
the MRDL. For chlorine dioxide, a PWS is in compliance with the MRDL when daily
samples are taken at the entrance to the distribution system and no two
consecutive daily samples exceed the MRDL. MRDLs are enforceable in the same
manner as maximum contaminant levels under Section 1412 of the Safe Drinking
Water Act. There is convincing evidence that addition of a disinfectant is
necessary for control of waterborne microbial contaminants. Notwithstanding the
MRDLs, operators may increase residual disinfectant levels of chlorine or
chloramines (but not chlorine dioxide) in the distribution system to a level
and for a time necessary to protect public health to address specific
microbiological contamination problems caused by circumstances such as
distribution line breaks, storm runoff events, source water contamination, or
cross-connections.
(63) "Maximum
Total Trihalomethane Potential (MTP)" means the maximum concentration of total
trihalomethanes produced in a given water containing a disinfectant residual
after 7 days at a temperature of 25°C or above.
(64) "Medium-size water system" for the
purpose of the lead and copper rule means a water system that serves greater
than 3,300 and less than or equal to 50,000 persons.
(65) "Membrane filtration" is a pressure or
vacuum driven separation process in which particulate matter larger than 1
micrometer is rejected by an engineered barrier, primarily through a size
exclusion mechanism, and which has a measurable removal efficiency of a target
organism that can be verified through the application of a direct integrity
test. This definition includes the common membrane technologies of
microfiltration, ultrafiltration, nanofiltration, and reverse
osmosis.
(66) "Near the first
service connection" means at one of the twenty percent of all service
connections in the entire system that are nearest the water supply treatment
facility, as measured by the water transport time within the distribution
system.
(67) "Non-community water
system" means a public water system that is not a community water system. A
non-community water system is either a "transient non-community water system"
(TNCWS) or a "non-transient non-community water system" (NTNCWS).
(68) "Non-transient non-community water
system" or "NTNCWS" means a non-community water system that regularly serves at
least 25 of the same persons over six months per year.
(69) "Optimal corrosion control treatment"
for the purpose of lead and copper rule only means the corrosion control
treatment that minimizes the lead and copper concentrations at user's taps
while insuring that the treatment does not cause the water system to violate
any primary drinking water regulation.
(70) "Person" means any individual,
corporation, company, association, partnership, State, municipality, utility
district, water cooperative, or Federal agency.
(71) "Picocurie" (pCi) means that quantity of
radioactive material producing 2.22 nuclear transformations per
minute.
(72) "Plan documents" means
reports, proposals, preliminary plans, survey and basis of design data, general
and detailed construction plans, profiles, specifications and all other
information pertaining to public water system planning.
(73) "Plant intake" refers to the works or
structures at the head of a conduit through which water is diverted from a
source (e.g., river or lake) into the treatment plant.
(74) "Point of disinfectant application" is
the point where the disinfectant is applied and water downstream of that point
is not subject to recontamination by surface water runoff.
(75) "Point-of-Entry Treatment Device" (POE)
means a device applied to the drinking water entering a house or building for
the purpose of reducing contaminants in the drinking water distributed
throughout the house or building.
(76) "Point-of-Use Treatment Device" (POU)
means a treatment device applied to a single tap used for the purpose of
reducing contaminants in drinking water at that one tap.
(77) "Presedimentation" is a preliminary
treatment process used 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.
(78) "Primary drinking water regulation"
means a rule promulgated by the Board which:
(a) Applies to public water
systems;
(b) Specifies contaminants
which, in the judgment of the Department, may have any adverse effect on the
health of persons;
(c) Specifies
for each such contaminant either:
1. A maximum
contaminant level, if, in the judgment of the Department, it is economically
and technologically feasible to ascertain the level of such contaminant in
water in public water systems, or
2. If, in the judgment of the Department, it
is not economically or technologically feasible to so ascertain the level of
such contaminant, each treatment technique known to the Department which leads
to a reduction in the level of such contaminant sufficient to satisfy the
requirements of Rule
0400-45-01-.06;
and
(d) Contains
criteria and procedures to assure a supply of drinking water which dependably
complies with such maximum contaminant levels or treatment techniques,
including quality control and testing procedures to insure compliance with such
levels and to insure proper operation and maintenance of the system, and
requirements regarding (i) the minimum quality of water which may be taken into
the system and (ii) siting for new facilities for public water
systems.
(79) "Public
water system" means a system for the provision of piped water for human
consumption if the system serves 15 or more connections or which regularly
serves 25 or more individuals daily at least 60 days out of the year and
includes:
(a) Any collection, treatment,
storage or distribution facility under control of the operator of such system
and used primarily in connection with such system; and
(b) Any collection or pre-treatment storage
facility not under such control which is used primarily in connection with such
system.
The population of a water system shall be determined by actual
count or by multiplying the household factor by the number of connections in
the system. The household factor shall be taken from the latest federal census
for that county or city. Water systems serving multi-family residences such as
apartment complexes and mobile home parks shall include each individual
residence unit as a connection in determining the population for the
system.
(80)
"Rem" means the unit of dose equivalent from ionizing radiation to the total
body or any internal organ or organ system. A "millerem (mrem)" is 1/1000 of a
rem.
(81) "Repeat compliance
period" means any subsequent compliance period after the initial compliance
period.
(82) "Residual disinfectant
concentration" ("C" in CT calculations) means the concentration of disinfectant
measured in mg/l in a representative sample of water.
(83) "Safe Drinking Water Act" means the
Federal law codified in
42
United States Code 300f et seq.,
Public Law
93 523, dated December 16, 1974 and subsequent
amendments.
(84) "Sanitary defect"
is a defect that could provide a pathway of entry for microbial contamination
into the distribution system or that is indicative of a failure or imminent
failure in a barrier that is already in place.
(85) "Sanitary survey" means an on-site
review of the water source, facilities, equipment, operation and maintenance of
a public water system for the purpose of evaluating the adequacy of such
sources, facilities, equipment, operation and maintenance for producing and
distributing safe drinking water.
(86) "Seasonal system" is a non-community
water system that is not operated as a public water system on a year-round
basis and starts up and shuts down at the beginning and end of each operating
season.
(87) "Secondary drinking
water regulation" means a rule promulgated by the Board which applies to public
water systems and which specifies the maximum contaminant levels which, in the
judgment of the Board, are requisite to protect the public welfare. Such rules
may vary according to geographic and other circumstances, and may apply to any
contaminant in drinking water which may:
(a)
Adversely affect the odor or appearance of such water and consequently may
cause the persons served by the public water system providing such water to
discontinue its use; or
(b)
Otherwise adversely affect the public welfare.
(88) "Sedimentation" means a process for
removal of solids before filtration by gravity or separation.
(89) "Service line sample" means a one liter
sample of water collected in accordance with part (7)(b)3. of Rule
0400-45-01-.33,
that has been standing for at least 6 hours in a service line.
(90) "Single family structure" for the
purpose of lead and copper rules means a building constructed as a single
family residence that is currently used as either a residence or a place of
business.
(91) "Slow sand
filtration" means a process involving passage of a raw water through a bed of
sand at low velocity (generally less than 0.4 m/h) resulting in substantial
particulate removal by physical and biological mechanisms.
(92) "Small water system" for the purpose of
the lead and copper rules only, means a water system that serves 3,300 or fewer
persons.
(93) "Subpart H systems"
means public water systems using surface water or ground water under the direct
influence of surface water as a source that are subject to the requirements of
Rules
0400-45-01-.17,
0400-45-01-.31
and
0400-45-01-.39.
(94) "Supplier of water" means any person who
owns or operates a public water system.
(95) "Surface water" means all water which is
open to the atmosphere and subject to surface runoff.
(96) "SUVA" means Specific Ultraviolet
Absorption at 254 nanometers (nm), an indicator of the humic content of water.
It is a calculated parameter obtained by dividing a sample's ultraviolet
absorption at a wavelength of 254 nm (UV 254/ (in m) by its concentration of
dissolved organic carbon (DOC) (in mg/L).
(97) "System with a single service
connection" means a system which supplies drinking water to consumers via a
single service line.
(98) "Too
numerous to count" means that the total number of bacterial colonies exceeds
200 on a 47 millimeter diameter membrane filter used for coliform
detection.
(99) "Total Organic
Carbon" (TOC) means total organic carbon in mg/L measured using heat, oxygen,
ultraviolet irradiation, chemical oxidants, or combinations of these oxidants
that convert organic carbon to carbon dioxide, rounded to two significant
figures.
(100) "Total
trihalomethane" (TTHM) means the sum of concentration in milligrams per liter
of the trihalomethane compounds trihalomethane (chloroform),
dibromochloromethane, bromodichloro-methane and tribomomethane (bromoform),
rounded to two significant figures.
(101) "Transient non-community water system"
or "TNCWS" means a non-community water system that regularly serves at least 25
individuals daily at least 60 days out of the year. A transient non-community
water system is a public water supply system that generally serves a transient
population such as hotels, motels, restaurants, camps, service stations
churches, industry, and rest stops.
(102) "Trihalomethane" (THM) means one of the
family of organic compounds, named as derivatives of methane, wherein three of
the four hydrogen atoms in methane are each substituted by a halogen atom in
the molecular structure.
(103)
"Two-stage lime softening" is a process in which chemical addition and hardness
precipitation occur in each of two distinct unit clarification
processes.
(104) "Uncovered
finished water storage facility" is a tank, reservoir, or other facility used
to store water that will undergo no further treatment except residual
disinfection and is open to the atmosphere.
(105) "Viable water system" means a public
water system which has the commitment and the financial, managerial, and
technical capacity to consistently comply with the Tennessee Safe Drinking
Water Act and these rules.
(106)
"Virus" means a virus of fecal origin which is infectious to humans by
waterborne transmission.
(107)
"Waterborne disease outbreak" means a significant occurrence of acute
infectious illness, epidemiologically associated with the ingestion of water
from a public water system which is deficient in treatment, as determined by
the appropriate local or State agency.
(108) "Wholesale system" is a public water
system that treats source water as necessary to produce finished water and then
delivers some or all of that finished water to another public water system.
Delivery may be through a direct connection or through the distribution system
of one or more consecutive systems.