As used in these rules, unless the context indicates
(1) "Act" means the Oregon
Drinking Water Quality Act of 1981 (ORS
(2) "Action Level"
means the concentration of lead or copper in water which determines, in some
cases, the treatment requirements that a water system is required to
(3) "Administrator" means
the Director of the Oregon Health Authority or his/her designee.
(4) "Approval" or "Approved" means approved
(5) "Approved Air Gap"
means a physical separation between the free-flowing discharge end of a potable
water supply pipeline and an open or non-pressurized receiving vessel. An
"Approved Air Gap" shall be at least twice the diameter of the supply pipe
measured vertically above the overflow rim of the vessel and in no case less
than 1 inch (2.54 cm), and in accord with Oregon Plumbing Specialty
(6) "Approved Backflow
Prevention Assembly" means a Reduced Pressure Principle Backflow Prevention
Assembly, RPDA, Double Check Valve Backflow Prevention Assembly, Double
Check-Detector Backflow Prevention Assembly, Pressure Vacuum Breaker
Backsiphonage Prevention Assembly, or Spill-Resistant Pressure Vacuum Breaker
Backsiphonage Prevention Assembly, of a make, model, orientation, and size
approved by the Authority. Assemblies listed in the currently approved backflow
prevention assemblies list developed by the University of Southern California,
Foundation for Cross-Connection Control and Hydraulic Research, or other
testing laboratories using equivalent testing methods, are considered approved
by the Authority.
means a water saturated and permeable geological formation, group of
formations, or part of a formation that is capable of transmitting water in
sufficient quantity to supply wells or springs.
(8) "Atmospheric Vacuum Breaker" or "AVB"
means a non-testable device consisting of an air inlet valve or float check, a
check seat and an air inlet port(s). This device is designed to protect against
a non-health hazard or a health hazard under a backsiphonage condition only.
Product and material approval is under the Oregon Plumbing Specialty
(9) "Authority" means the
Oregon Health Authority or its designee.
(10) "AWWA" means the American Water Works
(11) "Backflow" means
the flow of water or other liquids, mixtures, or substances into the
distributing pipes of a potable supply of water from any sources other than its
intended source, and is caused by backsiphonage or backpressure.
(12) "Backflow Prevention Assembly" means a
backflow prevention assembly such as a Pressure Vacuum Breaker Backsiphonage
Prevention Assembly, Spill-Resistant Pressure Vacuum Breaker Backsiphonage
Prevention Assembly, Double Check Valve Backflow Prevention Assembly, Double
Check-Detector Backflow Prevention Assembly, Reduced Pressure Principle
Backflow Prevention Assembly, or Reduced Pressure Principle-Detector Backflow
Prevention Assembly and the attached shutoff valves on the inlet and outlet
ends of the assembly, assembled as a complete unit.
(13) "Backpressure" means an elevation of
pressure downstream of the distribution system that would cause, or tend to
cause, water to flow opposite of its intended direction.
(14) "Backsiphonage" means a drop in
distribution system pressure below atmospheric pressure (partial vacuum), that
would cause, or tend to cause, water to flow opposite of its intended
(15) "Bank Filtration"
means a water treatment process that uses a horizontal or vertical well to
recover surface water that has naturally infiltrated into groundwater through a
river bed or bank(s). Infiltration is typically enhanced by the hydraulic
gradient imposed by a nearby pumping water supply.
(16) "Best Available Technology" or "BAT"
means the best technology, treatment techniques, or other means which the EPA
finds, after examination for efficacy under field conditions and not solely
under laboratory conditions, are available (taking cost into
Water" means potable water from a source approved by the Authority for domestic
use which is placed in small, easily transportable containers.
(18) "Calculated Fixed Radius" means a
technique to delineate a wellhead protection area, based on the determination
of the volume of the aquifer needed to supply groundwater to a well over a
given length of time.
means the Code of Federal Regulations. Specifically, it refers to those
sections of the code which deal with the National Primary and Secondary
Drinking Water Regulations.
"Check Valve" means a valve, which allows flow in only one direction.
(21) "Coagulation" means a process using
coagulant chemicals and mixing by which colloidal and suspended materials are
destabilized and agglomerated into floc.
"Coliform Investigation" 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 investigation was triggered at the water system.
Coliform investigations are classified as level 1 or level 2 as prescribed by
"Coliform-Positive" means the presence of coliform bacteria in a water
(24) "Combined distribution
system" means the interconnected distribution system consisting of the
distribution systems of wholesale water systems and of the purchasing water
systems that receive finished water.
(25) "Community Water System" means a public
water system that has 15 or more service connections used by year-round
residents, or that regularly serves 25 or more year-round residents.
(26) "Compliance Cycle" means the nine-year
calendar year cycle during which public water systems must monitor. Each
compliance cycle consists of three three-year compliance periods. The first
calendar year cycle begins January 1, 1993 and ends December 31,
(27) "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; and
the third from January 1, 1999 to December 31, 2001.
(28) "Comprehensive performance evaluation"
or "CPE" means 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.
The CPE must consist of at least the following components: Assessment of plant
performance; evaluations of major unit processes; identification and
prioritization of performance limiting factors; assessment of the applicability
of comprehensive technical assistance; and preparation of a CPE
(29) "Connection." See
"Constructed Conveyance" means any human-made conduit such as ditches,
culverts, waterways, flumes, mine drains, canals or any human-altered natural
water bodies or waterways as determined by the Authority.
(31) "Contaminant" means any physical,
chemical, biological, or radiological substance or matter in water that creates
a health hazard.
Plan" means a document setting out an organized, planned and coordinated course
of action to be followed in the event of a loss of capacity to supply water to
the distribution system or in case of a fire, explosion or release of hazardous
waste which could threaten human health or the environment.
(33) "Continuing Education Unit" or "CEU"
means a nationally recognized unit of measurement for assigning credits for
education or training that provides the participant with advanced or post high
school learning. One CEU is awarded for every 10 classroom hours of lecture or
the equivalent of participation in an organized education experience, conducted
under responsible sponsorship, capable direction and qualified instruction as
determined by the Authority or its designee.
(34) "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.
"Cross Connection" means any actual or potential unprotected connection or
structural arrangement between the public or user's potable water system and
any other source or system through which it is possible to introduce into any
part of the potable system any used water, industrial fluid, gas, or substances
other than the intended potable water with which the system is supplied. Bypass
arrangements, jumper connections, removable sections, swivel, or change-over
devices, and other temporary or permanent devices through which, or because of
which, backflow can occur are considered to be cross connections.
(36) "CT" means the product of the residual
disinfectant concentration "C" (measured in mg/l) and disinfectant contact
time(s), "T" (measured in minutes).
(37) "Degree of Hazard" means either
pollution (non-health hazard) or contamination (health hazard) and is
determined by an evaluation of hazardous conditions within a system.
(38) "Delineation" means the determination of
the extent, orientation and boundaries of a wellhead protection area using
factors such as geology, aquifer characteristics, well pumping rates and time
Study" means a series of tests performed to prove an overall effective removal
or inactivation rate of a pathogenic organism through a treatment or
Responsible Charge" or "DRC" means an individual designated by the owner or
authorized agent to make decisions regarding the daily operational activities
of a public water system, water treatment facility or distribution system, that
will directly impact the quality or quantity of drinking water.
(41) "Disinfectant Contact Time" means the
time in minutes that it takes for water to move from the point of disinfectant
application or the previous point of disinfection residual measurement to a
point before or at the point where residual disinfectant concentration is
Residual Maintenance" means a process where chlorine or another chemical is
added to the water supply at a public water system for the purpose of
maintaining a disinfectant residual in the distribution system.
(43) "Disinfection" means a process by which
a chemical or ultraviolet light is used to inactivate pathogenic organisms in
water. Disinfection intended to inactivate one or more pathogens in source
water is referred to as disinfection for pathogen inactivation and is
characterized by monitoring to verify the inactivation achieved.
(44) "Disinfection profile" means a summary
of Giardia lamblia inactivation through the treatment
(45) "Distribution System"
means that portion of the water system in which water is stored or conveyed
from the water treatment plant or other supply point to the premises of a
(46) "Domestic" means
provided for human consumption.
(47) "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.
(48) "Double Check-Detector Backflow
Prevention Assembly" or "DCDA" means a specially designed assembly composed of
a line size approved double check valve assembly assembled with a bypass
containing a specific water meter and an approved double check valve assembly.
The meter shall register accurately for only very low rates of flow up to three
gallons per minute and shall show a registration for all rates of flow. This
assembly is designed to protect against a non-health hazard.
(49) "Double Check Valve Backflow Prevention
Assembly" or "DC" means an assembly of two independently acting approved check
valves, including tightly closing resilient seated shutoff valves attached at
each end of the assembly and fitted with properly located resilient seated test
cocks. This assembly is designed to protect against a non-health
(50) "Drawdown" means the
difference, measured vertically, between the static water level in the well and
the water level during pumping.
(51) "Drinking Water Protection" means
implementing strategies within a drinking water protection area to minimize the
potential impact of contaminant sources on the quality of water being used as a
drinking water source by a Public Water System.
(52) "Drinking Water Protection Area" or
"DWPA" means the source area supplying drinking water to a Public Water System.
For a surface water-supplied drinking water source the DWPA is all or a
specifically determined part of a lake's, reservoir's or stream's watershed
that has been certified by the Department of Environmental Quality. For a
groundwater-supplied drinking water source the DWPA is the area on the surface
that directly overlies that part of the aquifer that supplies groundwater to a
well, well field or spring that has been certified by the Authority.
"Drinking Water Protection Plan" means a
plan, certified by the Department of Environmental Quality according to OAR
, which identifies the actions to be taken at the
local level to protect a specifically defined and certified DWPA. The plan is
developed by the local Responsible Management Authority or team and includes a
written description of each element, public participation efforts, and an
sample set" means a set of two samples collected at the same time and same
location, with one sample analyzed for TTHM and the other for HAA5. Dual sample
sets are collected for the purposes of conducting an Initial Distribution
System Evaluation (IDSE) as prescribed in 333-061-0036(4)(b) of these rules,
and for determining compliance with the MCLs for TTHM and HAA5 listed in OAR
"Emergency" means a condition resulting from an unusual calamity such as a
flood, storm, earthquake, drought, civil disorder, volcanic eruption, an
accidental spill of hazardous material, or other occurrence which disrupts
water service at a public water system or endangers the quality of water
produced by a public water system.
(56) "Emergency Response Plan" means a
written document establishing contacts, operating procedures, and actions taken
for a public water system to minimize the impact or potential impact of a
natural disaster, accident, or intentional act which disrupts or damages, or
potentially disrupts or potentially damages the public water system or drinking
water supply, and returns the public water system to normal operating
coagulation" means the addition of sufficient coagulant for improved removal of
disinfection byproduct precursors by conventional filtration
softening" means the improved removal of disinfection byproduct precursors by
means the United States Environmental Protection Agency.
"Filtration" means a process for
removing particulate matter from water through porous media.
(a) "Bag filtration" means a pressure-driven
separation process that removes particulate matter using engineered media. It
is typically constructed of 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
filtration" means a pressure-driven separation process that removes particulate
matter using engineered media. It is typically constructed of rigid or
semi-rigid, self-supporting filter elements housed in a pressure vessel in
which flow is from the outside of the cartridge to the inside.
(c) "Conventional Filtration Treatment" means
a series of processes including coagulation (requiring the use of a primary
coagulant and rapid mix), flocculation, sedimentation, and filtration resulting
in substantial particulate removal.
(d) "Direct Filtration Treatment" means a
series of processes including coagulation (requiring the use of a primary
coagulant and rapid mix) and filtration but excluding sedimentation resulting
in substantial particulate removal.
"Diatomaceous Earth Filtration" means a
process resulting in substantial particulate removal in which:
(A) A precoat cake of diatomaceous earth
filter media is deposited on a support membrane (septum); and
(B) 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, in order to maintain the permeability of
the filter cake.
"Membrane filtration" means a pressure or vacuum driven separation process in
which particulate matter larger than one micrometer is rejected by engineered
media, 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
(g) "Slow Sand
Filtration" means a process involving passage of raw water through a bed of
sand at low velocity (generally less than 235 gallons per square foot per day)
resulting in substantial particulate removal by both physical and biological
"Filtration Endorsement" means a special certification that may be added to an
operator's water treatment level 2 certification, and is related to the
operator's experience with and knowledge of the operation of conventional and
direct filtration treatment.
"Finished water" means water that is introduced into the distribution system of
a public water system and intended for distribution and consumption without
further treatment, except as necessary to maintain water quality in the
distribution system such as booster disinfection or the addition of corrosion
Customer" means the initial service connection or tap on a public water supply
after any treatment processes.
"Flocculation" 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.
(65) "GAC" means granular activated
(66) "Gross Alpha Particle
Activity" means the total radioactivity due to alpha particle emission as
inferred from measurements on a dry sample.
(67) "Gross Beta Particle Activity" means the
total radioactivity due to beta particle emission as inferred from measurements
on a dry sample.
means any water, except capillary moisture, beneath the land surface or beneath
the bed of any stream, lake, reservoir or other body of surface water within
the boundaries of this state, whatever may be the geologic formation or
structure in which such water stands, flows, percolates or otherwise
(69) "Groundwater System"
means any public water system that uses groundwater, including purchasing water
systems that receive finished groundwater, but excluding public water systems
that combine all of their groundwater with surface water or groundwater under
the direct influence of surface water prior to treatment.
(70) "Groundwater under the direct influence
of surface water" or "GWUDI" means any water beneath the surface of the ground
with significant occurrence of insects or other macro-organisms, 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.
(71) "Haloacetic acids (five)" or "HAA5"
means 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.
"Health Hazard (Contamination)" means an impairment of the quality of the water
that could create an actual hazard to the public health through poisoning or
through the spread of disease by sewage, industrial fluids, waste, or other
Consumption" means water used for drinking, personal hygiene bathing,
showering, cooking, dishwashing, and maintaining oral hygiene.
(74) "Hydraulic Gradient" means the slope of
the water table or potentiometric surface, calculated by dividing the change in
hydraulic head between two points by the horizontal distance between the points
in the direction of groundwater flow.
(75) "Hydraulic Head" means the energy
possessed by the water mass at a given point, related to the height above the
datum plane that water resides in a well drilled to that point. In a
groundwater system, the hydraulic head is composed of elevation head and
Gallery" means a system of perforated pipes laid along the banks or under the
bed of a stream or lake installed for the purpose of collecting water from the
formation beneath the stream or lake.
"Lead Free" means:
(a) Not containing more than 0.2 percent lead
when used with respect to solders and flux; and
(b) Not more than a weighted average of 0.25
percent lead when used with respect to the wetted surfaces of pipes, pipe
fittings, plumbing fittings, and fixtures.
(78) "Legionella" means a
genus of bacteria, some species of which have caused a type of pneumonia called
Administrative Authority" means the individual official, board, department or
agency established and authorized by a state, county or city to administer and
enforce the provisions of the Oregon State Plumbing Specialty Code adopted
under OAR 918-750-0110
"Locational running annual average" or "LRAA" means the arithmetic average of
analytical results for samples taken at a specific monitoring location during
the previous four calendar quarters.
(81) "Major Additions or Modifications" means
changes of considerable extent or complexity including, but not limited to,
projects involving water sources, treatment or disinfection facilities,
finished water storage, pumping facilities, transmission mains, and
distribution mains, except main replacements of the same length and
(82) "Master Plan" means
an overall plan, which shows the projected development of a distribution system
and alternatives for source development.
(83) "Maximum Contaminant Level" or "MCL"
means the maximum allowable level of a contaminant in water delivered to the
users of a public water system, except in the case of turbidity where the
maximum allowable level is measured at the point of entry to the distribution
Disinfectant Level" or "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. The MRDLs for chlorine,
chloramines and chlorine dioxide are identified in OAR 333-061-0031
(85) "Non-Health Hazard (Pollution)" means an
impairment of the quality of the water to a degree that does not create a
hazard to the public health, but does adversely affect the aesthetic qualities
of such water for potable use.
"Non-Transient Non-Community Water System" or "NTNC" means a public water
system that regularly serves at least 25 of the same persons over 6 months per
(87) "Operating Experience"
means knowledge gained through the direct performance of duties, tasks, and
responsibilities at a drinking water system or in a related field.
(88) "Operational Decision Making" means the
act of making decisions about alternatives in the performance of a water
treatment plant or distribution system relating to water quality or water
quantity that may affect public health.
(89) "Operator," means a person responsible
for the operation of a water treatment plant or distribution system.
(90) "Optimal Corrosion Control Treatment"
means the corrosion control treatment that minimizes the lead and copper
concentrations at users' taps while insuring that the treatment does not cause
the water system to violate any national primary drinking water
(91) "Oregon Very
Small Water System" means a public water system, which serves 4 to 14 service
connections or that serves commercial or public premises which are used by 10
to 24 people at least 60 days per year.
(92) "Pathogenic" means a specific agent
(bacterium, virus or parasite) causing or capable of causing disease.
(93) "Permit" means official permission
granted by the Authority for a public water system which exceeds maximum
contaminant levels to delay, because of economic or other compelling factors,
the installation of water treatment facilities which are necessary to produce
water which does not exceed MCLs.
(94) "Person" means any individual,
corporation, association, firm, partnership, municipal, state or federal
agency, or joint stock company and includes any receiver, special master,
trustee, assignee, or other similar representative thereof.
(95) "Picocurie" or "pCi" means that quantity
of radioactive material producing 2.22 nuclear transformations per
(96) "Point of Delivery" or
"POD" means the point of connection between a public water system and the
user's water system. Beyond the POD, the Oregon Plumbing Specialty Code
applies. See "Service Connection."
(97) "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.
(98) "Point-of-Entry Treatment Device" is a
treatment 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.
(99) "Point-of-Use Treatment Device" is a
treatment device applied to a single tap used for the purpose of reducing
contaminants in drinking water at that one tap.
(100) "Potable Water." See Safe Drinking
(101) "Potential Contaminant
Source Inventory" means the determination of the location within the wellhead
protection area of activities known to use or produce materials that can
"Potential Cross Connection" means a cross connection that would most likely
occur, but may not be taking place at the time of an inspection.
(103) "Potentiometric Surface" means a
surface that denotes the variation of hydraulic head in the given aquifer
across an area.
means real estate and the structures on it.
(105) "Premises Isolation" means the practice
of protecting the public water supply from contamination or pollution by
installing backflow prevention assemblies at, or near, the POD where the water
supply enters the premises. Premises isolation does not guarantee protection to
persons on the premises.
"Presedimentation" means 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
Vacuum Breaker Backsiphonage Prevention Assembly" or "PVB" means an assembly
consisting of an independently operating, internally loaded check valve and an
independently operating loaded air inlet valve located on the discharge side of
the check valve. This assembly is to be equipped with properly located
resilient seated test cocks and tightly closing resilient seated shutoff valves
attached at each end of the assembly. This assembly is designed to protect
against a non-health hazard or a health hazard under backsiphonage conditions
(108) "Public Health Hazard"
means a condition, device or practice which is conducive to the introduction of
waterborne disease organisms, or harmful chemical, physical, or radioactive
substances into a public water system, and which presents an unreasonable risk
(109) "Public Water
System" means a system for the provision to the public of piped water for human
consumption, if such system has more than three service connections, or
supplies water to a public or commercial establishment that operates a total of
at least 60 days per year, and that is used by 10 or more individuals per day.
Public water system also means a system for the provision to the public of
water through constructed conveyances other than pipes to at least 15 service
connections or regularly serves at least 25 individuals daily at least 60 days
of the year. A public water system is either a "Community Water System," a
"Transient Non-Community Water System," a "NTNC Water System" or an "Oregon
Very Small Water System."
"Purchasing Water System" means a public water system which obtains its water
in whole or in part from one or more public water systems. Delivery may be
through a direct connection or through the distribution system of one or more
purchasing water systems.
"Recharge" means the process by which water is added to a zone of saturation,
usually by downward infiltration from the surface.
(112) "Reduced Pressure Principle Backflow
Prevention Assembly" or "RP" means an assembly containing two independently
acting approved check valves, together with a hydraulically operating,
mechanically independent pressure differential relief valve located between the
check valves and at the same time below the first check valve. The unit shall
include properly located resilient seated test cocks and tightly closing
resilient seated shutoff valves at each end of the assembly. This assembly is
designed to protect against a non-health hazard or a health hazard.
(113) "Reduced Pressure Principle-Detector
Backflow Prevention Assembly" or "RPDA" means a specifically designed assembly
composed of a line size approved RP with a bypass containing a specific water
meter and an approved RP. The meter shall register accurately for only very low
rates of flow up to three gallons per minute and shall show a registration for
all rates of flow. This assembly is designed to protect against a non-health
hazard or a health hazard.
"Rem" means the unit of dose equivalent from ionizing radiation to the total
body or any internal organ or organ system. A "millirem" or "mrem)" is 1/1000
of a rem.
disinfectant concentration" means the concentration of disinfectant measured in
mg/l in a representative sample of water.
(116) "Responsible Management Authority"
means the Public Water System whose water supply is being protected and any
government entity having management, rule or ordinance-making authority to
implement wellhead protection management strategies within the wellhead
protection area. The Responsible Management Authority is responsible for
implementation of the Wellhead Protection Plan and includes cities, counties,
special districts, Indian tribes, state/federal entities as well as public
(117) "Safe Drinking
Water" means water which has sufficiently low concentrations of
microbiological, inorganic chemical, organic chemical, radiological or physical
substances so that individuals drinking such water at normal levels of
consumption, will not be exposed to disease organisms or other substances which
may produce harmful physiological effects.
(118) "Sanitary Defect" means 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.
(119) "Sanitary Survey" or "Water System
Survey" means an on-site review of the water source(s), facilities, equipment,
operation, maintenance and monitoring compliance of a public water system to
evaluate the adequacy of the water system, its sources and operations in the
distribution of safe drinking water. The sanitary survey also identifies
sources of contamination by using the results of source water assessments where
(120) "Seasonal water
system" means a water system operated as a non-community public water system
only part of each year and that is started up at the beginning and shut down at
the end of each operating season.
"Secondary Contaminant" means those
contaminants, which, at the levels generally found in drinking water, do not
present an unreasonable risk to health, but do:
(a) Have adverse effects on the taste, odor
and color of water;
undesirable staining of plumbing fixtures; or
(c) Interfere with treatment processes
applied by water suppliers.
(122) "Secondary Maximum Contaminant Level"
or "SMCL" means the level of a secondary contaminant which when exceeded may
adversely affect the aesthetic quality of the drinking water which thereby may
deter public acceptance of drinking water provided by public water systems or
may interfere with water treatment methods.
(123) "Sedimentation" means a process for
removal of solids before filtration by gravity or separation.
(124) "Service Connection" means the piping
connection through which water is conveyed from a public water system to a
Deficiency" means a defect in design, operation, or maintenance, or a
malfunction of the source(s), treatment, storage, or distribution system that
has been determined to cause or have the potential for causing the introduction
of contamination into the water delivered to consumers.
"Small Water System Certification," for
the purposes of OAR 333-061-0220
and 0228, means operator certification for a
community or NTNC water system serving 150 service connections or less and that
uses only groundwater sources or purchases finished water from another public
(127) "Source Water
Assessment" means the information compiled by the Authority and the Department
of Environmental Quality (DEQ), consisting of the delineation, inventory and
susceptibility analyses of the drinking water source, which enable public water
systems to develop and implement drinking water protection plans.
(128) "Specific Ultraviolet Absorption" or
"SUVA" means an indicator of the humic content of water as a calculated
parameter obtained by dividing a sample's ultraviolet absorption at a
wavelength of 254 nanometers by its concentration of dissolved organic carbon
in milligrams per liter.
"Spill Resistant Pressure Vacuum Breaker Backsiphonage Prevention Assembly" or
"SVB" means an assembly containing an independently operating, internally
loaded check valve and independently operating loaded air inlet valve located
on the discharge side of the check valve. The assembly is to be equipped with a
properly located resilient seated test cock, a properly located bleed/vent
valve, and tightly closing resilient seated shutoff valves attached at each end
of the assembly. This assembly is designed to protect against a non-health
hazard or a health hazard under a backsiphonage condition only.
(130) "Spring" means a naturally occurring
discharge of flowing water at the ground surface, or into surface water where
the flow of water is the result of gravity or artesian pressure. Springs can be
derived from groundwater or they can be surface water influenced.
(131) "Static Water Level" means the vertical
distance from ground surface to the water level in the well when the well is at
rest, that is, the well has not been pumped recently and the water level is
stable. This is the natural level of water in the well.
(132) "Surface Water" means all water, which
is open to the atmosphere and subject to surface runoff.
(133) "Susceptibility" means the potential,
as a result of the combination of land use activities and source water
sensitivity, that contamination of the drinking water source may
(134) "Team" means the local
Wellhead Protection team, which includes representatives from the Responsible
Management Authorities and various interests and stakeholders potentially
affected by the Wellhead Protection Plan.
"Time-of-Travel" or "TOT" means the amount of time it takes groundwater to flow
to a given well. TOT is the criterion that effectively determines the radius in
the calculated fixed radius method and the up-gradient distance to be used for
the analytical and numerical models during delineation of the wellhead
Organic Carbon" or "TOC" means total organic carbon in milligrams per liter
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.
(138) "Total Trihalomethanes" or "TTHM" means
the sum of the concentrations in milligrams per liter of the trihalomethane
compounds bromodichloromethane, dibromochloromethane, tribromomethane
(bromoform) and trichloromethane (chloroform), rounded to two significant
figures after addition.
"Transient Non-Community Water System" or "TNC" means a public water system
that serves a transient population of 25 or more persons.
(140) "Turbidity" means a measure of the
cloudiness of water caused by suspended particles. The units of measure for
turbidity are nephelometric turbidity units (NTU).
(141) "Two-stage lime softening" means a
process in which a chemical addition and hardness precipitation occur in each
of two distinct unit clarification processes in series prior to
finished water storage facility" means a tank, reservoir, or other facility
used to store water that will undergo no further treatment to reduce microbial
pathogens except residual disinfection and is directly open to the
(143) "Vadose Zone"
means the zone between the ground surface and the water table where the
available open spaces between soil and sediment particles, in rock fractures,
etc., are most filled with air.
(144) "Variance" means official permission
granted by the Authority for public water systems to exceed MCLs because the
quality of the raw water is such that the best available treatment techniques
are not capable of treating the water so that it complies with MCLs, and there
is no unreasonable risk to health.
(145) "Vault" means an approved enclosure
above or below ground to house a backflow prevention assembly that complies
with the local administrative authority having jurisdiction.
(146) "Virus" means a virus of fecal origin,
which is infectious to humans by waterborne transmission.
(147) "Vulnerability" has the same meaning as
means official permission from the Authority for a public water system to
deviate from the construction standards set forth in these rules.
(149) "Waterborne disease outbreak" means the
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 Authority.
(150) "Water Source" means any lake, stream,
spring, groundwater supply, impoundment or other source of water from which
water is obtained for a public water system. In some cases, a public water
system can be the source of supply for one or more other public water
(151) "Water Supplier"
means a person, group of persons, municipality, district, corporation or other
entity, which owns or operates a public potable water system.
(152) "Water System" means a system for the
provision of piped water for human consumption.
(153) "Water System Operations Manual" means
a written document describing the actions and procedures necessary to operate
and maintain the entire water system.
(154) "Water Table" means the upper surface
of an unconfined aquifer, the surface of which is at atmospheric pressure and
fluctuates seasonally. It is defined by the levels at which water stands in
wells that penetrate the aquifer.
(155) "Water Treatment" means a process of
altering water quality by physical or chemical means and may include domestic,
industrial or commercial applications.
(156) "Water Treatment Plant" means that
portion of a water system that in some way alters the physical, chemical, or
bacteriological quality of the water being treated.
(157) "Well" means an artificial opening or
artificially altered natural opening, however made, by which ground water is
sought or through which ground water flows under natural pressure or is
artificially withdrawn or injected, provided that this definition shall not
include a natural spring, or wells drilled for the purpose of exploration or
production of oil or gas.
"Wellfield" means two or more drinking water wells, belonging to the same water
system that are within 2,500 feet, or as determined by the Authority, and
produce from the same and no other aquifer.
(159) "Wellhead Protection." See Drinking
Protection Area" or "WHPA." See Drinking Water Protection Area.
(161) "Wellhead Protection Plan." See
Drinking Water Protection Plan.
(162) "Wholesale system" means 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 purchasing water systems.