Virginia Administrative Code › Title 12 - HEALTH › Agency 5 - DEPARTMENT OF HEALTH › Chapter 590 - WATERWORKS REGULATIONS › Section 12VAC5-590-10 - Definitions and units of measurement

Current through Register Vol. 40, No. 24, July 15, 2024
A. Definitions. As used in this chapter, the
				following words, terms, and abbreviations shall have meanings respectively set
				forth unless the context clearly requires a different meaning:
"Action level" or "AL" means the concentration of lead or
				  copper in water specified in 12VAC5-590-385, which determines, in some cases,
				  the treatment requirements contained in 12VAC5-590-405 that an owner is
				  required to complete.
"Administrative Process Act" or "APA" means Chapter 40
				  (§ 2.2-4000 et seq.) of Title 2.2 of the Code of Virginia. The APA is the
				  basic law conferring authority on agencies either to make regulations or case
				  decisions as well as to standardize court review thereof.
"Air gap separation" means the unobstructed vertical
				  distance through the free atmosphere between the lowest point of the potable
				  water outlet and the flood rim of the receiving vessel.
"ANSI" means the American National Standards
				  Institute.
"Applied water" means water that is ready for
				  filtration.
"ASME" means the American Society of Mechanical
				  Engineers.
"ASSE" means the American Society of Sanitary
				  Engineering.
"ASTM" means the American Society for Testing and
				  Materials.
"Auxiliary water system" means any water supply or system on
				  or available to the premises of the consumer other than the waterworks. These
				  may be polluted or contaminated, objectionable, or of questionable quality and
				  constitute an unapproved water supply or system over which the waterworks owner
				  does not have control.
"AWWA" means the American Water Works Association.
"Backflow" means the undesirable reversal of flow of water
				  or mixtures of water and other liquids, gases, or other substances into a
				  waterworks.
"Backflow elimination method" means the air gap separation
				  or physical disconnection that will eliminate the cross-connection.
"Backflow prevention assembly" means a mechanical unit,
				  designed to control various cross-connections and stop the reversal of flow
				  that includes an inlet and outlet shutoff valve and test cocks to facilitate
				  testing of the assembly. Backflow prevention assemblies include the reduced
				  pressure principle backflow prevention assembly, the double check valve
				  assembly, and the pressure vacuum breaker assembly.
"Backflow prevention device" means a mechanical unit
				  designed to control cross-connections and stop the reversal of flow that is not
				  testable because it does not have inlet and outlet shutoff valves or test
				  cocks. A backflow prevention device is not generally designed or constructed to
				  withstand continuous pressure over 12 hours, or to control high hazards. A
				  backflow prevention device generally includes the atmospheric type vacuum
				  breakers and the dual check valve type devices.
"Backpressure backflow" means backflow caused by pressure in
				  the downstream piping that is superior to the supply pressure at the point of
				  consideration.
"Backsiphonage" means backflow caused by a reduction in
				  pressure that causes a partial vacuum, creating a siphon effect.
"Bag filters" means pressure-driven separation devices that
				  remove particulate matter larger than one micrometer using an engineered porous
				  filtration media. Bag filters are typically constructed of a nonrigid, fabric
				  filtration media housed in a pressure vessel in which the direction of flow is
				  from the inside of the bag to outside.
"Bank filtration" means a water treatment process that uses a
				  well to recover surface water that has naturally infiltrated into groundwater
				  through a river bed or bank. Infiltration is typically enhanced by the
				  hydraulic gradient imposed by a nearby pumping water supply or other
				  well.
"Best available technology" or "BAT" means the best
				  practicable technology, treatment techniques, or other means that the
				  department finds, after examination for efficacy under field conditions and not
				  solely under laboratory conditions, that are available (taking cost into
				  consideration).
"Board" means the State Board of Health.
"Boil water advisory" and "boil water notice" mean a
				  statement that informs consumers that drinking water is or may be contaminated
				  and that the water should be boiled before being used for human consumption.
"BSSP" means a bacteriological sample siting plan.
"CAP" means a corrective action plan.
"Cartridge filters" means pressure-driven separation devices
				  that remove particulate matter larger than one micrometer using an engineered
				  porous filtration media. Cartridge filters are typically constructed as 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.
"Case decision" means an agency determination as defined in
				  § 2.2-4001 of the Code of Virginia.
"CCCP" means a cross-connection control program.
"CCR" means consumer confidence report.
"CDC" means the Centers for Disease Control and
				  Prevention.
"CFE" means the combined filter effluent.
"CFR" means the Code of Federal Regulations.
"Clean compliance history" means a record of no PMCL
				  violations for microbiological contaminants, no monitoring violations under
				  12VAC5-590-370, and no coliform treatment technique trigger exceedances or
				  treatment technique violations under 12VAC5-590-392.
"Coagulation" means a process using coagulant chemicals and
				  mixing by which colloidal and suspended materials are destabilized and
				  agglomerated into floc.
"Combined distribution system" means the interconnected
				  distribution system consisting of the distribution systems of wholesale
				  waterworks and of the consecutive waterworks that receive finished
				  water.
"Commissioner" means the State Health Commissioner, who is
				  the executive officer of the board.
"Community waterworks" means a waterworks that serves at
				  least 15 service connections used by year-round residents or regularly serves
				  at least 25 year-round residents.
"Compliance cycle" means the nine-year calendar year cycle
				  during which a waterworks shall monitor. Each compliance cycle consists of
				  three three-year compliance periods. The first calendar year cycle began
				  January 1, 1993, and ended December 31, 2001, with subsequent compliance cycles
				  continuing thereafter.
"Compliance period" means a three-year calendar year period
				  within a compliance cycle. Each compliance cycle consists of three three-year
				  compliance periods. The first compliance period began January 1, 1993, and
				  ended December 31, 1995, with subsequent compliance periods continuing
				  thereafter.
"Comprehensive business plan" means a plan detailing the
				  technical, managerial, and financial commitments that the owner will make in
				  order to assure that the waterworks will have the capability to provide water
				  that complies with this chapter over the long term.
"Confirmation sample" means a sample to be collected by the
				  owner within a specified time after the results of the initial sample are known
				  to have exceeded a specified limit or standard in order to validate the initial
				  result and to determine compliance.
"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.
"Consecutive waterworks" means a waterworks that receives
				  some or all of its finished water from one or more waterworks. Consecutive
				  waterworks may provide additional treatment to finished water. Delivery may be
				  through a direct connection or through the distribution system of one or more
				  consecutive waterworks.
"Consolidated" means rock made from sedimentary, igneous, or
				  metamorphic materials that have been metamorphosed or cemented together forming
				  strata or bodies of rock.
"Consumer" means any person receiving water for human
				  consumption from a waterworks.
"Consumer's water system" means any water system located on
				  the consumer's premises, supplied by or in any manner connected to a
				  waterworks.
"Containment" means the safeguard against backflow into a
				  waterworks from a consumer's water system by installing an appropriate backflow
				  prevention assembly, backflow prevention device, or backflow elimination method
				  at the service connection or downstream of the service connection but before
				  any unprotected takeoffs.
"Contaminant" means any objectionable or hazardous 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.
"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 link,
				  connection, or physical arrangement, direct or indirect, between used water, an
				  auxiliary water system, or other source of contamination or pollution to the
				  waterworks through which backflow can occur.
"DBPPs" means disinfection byproduct precursors.
"DBPs" means disinfection byproducts.
"DCLS" means the Virginia Department of General Services,
				  Division of Consolidated Laboratory Services.
"Department" means the Virginia Department of Health.
"DEQ" means the Virginia Department of Environmental
				  Quality.
"Diatomaceous earth filtration" means a process resulting in
				  substantial particulate removal in which (i) a precoat cake of diatomaceous
				  earth filter media is deposited on a support membrane (septum), and (ii) 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.
"Direct filtration" means a series of processes including
				  coagulation and filtration but excluding sedimentation resulting in substantial
				  particulate removal.
"Disinfectant" means any chemical and physical agents,
				  including chlorine, chlorine dioxide, chloramines, ozone, and UV light, added
				  to water in any part of the treatment or distribution process for the purpose
				  of killing or inactivating pathogenic organisms.
"Disinfection" means a process that inactivates or destroys
				  pathogenic organisms in water by use of a disinfectant.
"Disinfection profile" means a summary of Giardia lamblia or
				  virus inactivation through the water treatment plant.
"Distribution main" means a water pipeline whose primary
				  purpose is to convey drinking water to service connections.
"Distribution system" means a network of pipelines and
				  appurtenances by which a waterworks delivers drinking water to its consumers.
"DOC" means the dissolved organic carbon in a water
				  sample.
"Double check valve assembly" or "double check detector
				  backflow assembly" means a backflow prevention assembly composed of two single
				  independently acting check valves including tightly closing shutoff valves
				  located at each end of the assembly and test cocks to facilitate testing of the
				  assembly, used for low hazard situations.
"DPOR" means the Virginia Department of Professional and
				  Occupational Regulation.
"Drawdown" means the difference, measured vertically,
				  between the static water level in the well and the water level during
				  pumping.
"Dual 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 sample analyzed for HAA5.
"Enhanced coagulation" means the addition of sufficient
				  coagulant for improved removal of disinfection byproduct precursors by
				  conventional filtration treatment.
"Enhanced softening" means the improved removal of
				  disinfection byproduct precursors by precipitative softening.
"Entry point" means the place where water from the source
				  after application of any treatment is delivered to the distribution system.
				  Where two or more sources are combined before distribution, the entry point is
				  the location that is representative of the blended water following all
				  treatment.
"EPA" means the U.S. Environmental Protection Agency.
"Exemption" means allowing a waterworks that satisfies the
				  criteria in 12VAC5-590-150 to deviate from a specific PMCL or treatment
				  technique requirement that is granted to the waterworks for a limited period of
				  time.
"Filter profile" means a graphical representation of
				  individual filter performance, based on continuous turbidity measurements or
				  total particle counts versus time for an entire filter run, from start-up to
				  backwash inclusively, that includes an assessment of filter performance while
				  another filter is being backwashed.
"Filtration" means a process for removing particulate matter
				  from water by passage through porous media.
"Finished water" means water that is introduced into the
				  distribution system of a waterworks and is intended for distribution and
				  consumption without further treatment, except as treatment is necessary to
				  maintain water quality in the distribution system (e.g., booster
				  disinfection).
"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.
"Flowing stream" means a course of running water flowing in
				  a definite channel.
"Free available chlorine" means that portion of the total
				  chlorine residual remaining in water at the end of a specified contact period
				  that will react chemically and biologically as hypochlorous acid or
				  hypochlorite ion.
"GAC" means granular activated carbon.
"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" means all water obtained from sources not
				  classified as surface water.
"Groundwater system" means any waterworks that uses
				  groundwater as its source of supply; however, a waterworks that combines all
				  its groundwater with surface water or with groundwater under the direct
				  influence of surface water before treatment is not a groundwater system.
				  Groundwater systems include consecutive waterworks that receive potable water
				  from another groundwater source.
"Groundwater under the direct influence of surface water" or
				  "GUDI" means any water beneath the surface of the ground with (i) significant
				  occurrence of insects or other macroorganisms, algae, or large-diameter
				  pathogens such as Giardia lamblia or Cryptosporidium or (ii) significant and
				  relatively rapid shifts in water characteristics such as turbidity,
				  temperature, conductivity, or pH that closely correlate to climatological or
				  surface water conditions. GUDI source determinations shall be made by the
				  department in accordance with 12VAC5-590-430.
"GWMA" means the groundwater management area designation by
				  the State Water Control Board.
"Haloacetic acids (five)" or "HAA5" means the sum of the
				  concentrations of the haloacetic acids, expressed in milligrams per liter
				  (mg/L) as rounded to two significant figures. For the purpose of this chapter
				  the HAA5 shall mean monochloroacetic acid, dichloroacetic acid, trichloroacetic
				  acid, monobromoacetic acid, and dibromoacetic acid.
"Halogen" means one of the chemical elements chlorine,
				  bromine, fluorine, astatine, or iodine.
"Health hazard" means any condition, device, or practice in a
				  waterworks or its operation that creates, or may create, a danger to the health
				  and well-being of the water consumer.
"HPC" means the heterotrophic plate count of a bacterial
				  population.
"Human consumption" means drinking, food preparation,
				  dishwashing, bathing, showering, hand washing, teeth brushing, and maintaining
				  oral hygiene.
"Hypochlorite" means the ionic component from the
				  disassociation of hypochlorous acid that performs the function of disinfection.
				  It is the available active ingredient in liquid hypochlorite disinfectants such
				  as sodium and calcium hypochlorite.
"Initial compliance period" means the compliance period in
				  which chemical and radiological monitoring began, and it is represented by the
				  first full three-year compliance period beginning at least 18 months after rule
				  promulgation. It applies to inorganic, organic, and radionuclide contaminants
				  listed in Tables 340.1, 340.2, and 340.4, respectively.
"Isolation" means the safeguard against backflow into a
				  waterworks from a consumer's water system by installing an appropriate backflow
				  prevention assembly or device or by installing a backflow elimination method at
				  the sources of potential contamination in the consumer's water system. This is
				  also called point-of-use isolation.
"Karst geology" means an area predominantly underlain by
				  limestone, dolomite, or gypsum and characterized by rapid underground drainage.
				  These areas often feature sinkholes, caverns, and sinking or disappearing
				  creeks.
"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.
"Lead free" means the following:
(i) when used with respect to solders and
				flux, refers to solders and flux containing not more than 0.2% lead; and
(ii) when used with respect to
				pipes, pipe fittings, plumbing fittings, and plumbing fixtures, refers to the
				weighted average of wetted surfaces of pipes, pipe fittings, plumbing fittings,
				and plumbing fixtures containing not more than 0.25% lead.
"Lead service line" means a pipeline made of lead that
				  connects the distribution main to the building inlet and any lead pigtail,
				  gooseneck, or other fitting that is connected to the lead pipeline.
"Leakage" means the loss of potable water from the
				  distribution system, up to the points of service connections, through breaks or
				  defects in piping and piping appurtenances.
"Legionella" means a genus of bacteria, some species of
				  which cause 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 waterworks
				  triggered the assessment.
"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 waterworks
				  triggered the assessment in a more comprehensive investigation than a Level 1
				  assessment.
"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.
"Log inactivation" means the inactivation of organisms
				  expressed on a logarithmic scale. For example, a 99.9% inactivation is a 3-log
				  inactivation; whereas a 99.99% inactivation is a 4-log inactivation.
"Log removal" means the removal of organisms expressed on a
				  logarithmic scale. For example, a 99.9% is a 3-log removal; whereas a 99.99%
				  removal is a 4-log removal.
"Maximum contaminant level" or "MCL" means the maximum
				  permissible level of a contaminant in potable water that is delivered to any
				  consumer of a waterworks. MCLs are set as close to the MCLGs as feasible using
				  the BAT. MCLs may be either "primary" (PMCL), meaning based on health
				  considerations, or "secondary" (SMCL), meaning based on aesthetic
				  considerations.
"Maximum contaminant level goal" or "MCLG" means the maximum
				  level of a contaminant in drinking water at which no known or anticipated
				  adverse effect on the health of persons would occur and that allows an adequate
				  margin of safety. Maximum contaminant level goals are nonenforceable health
				  goals.
"Maximum residual 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.
"Maximum residual disinfectant level goal" or "MRDLG" means
				  the maximum level of a disinfectant added for water treatment at which no known
				  or anticipated adverse effect on the health of persons would occur, and that
				  allows 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 residual disinfectant 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, and that has a measurable removal efficiency of a target organism
				  that can be verified through the application of a direct integrity test.
				  Included in this definition are the common membrane classifications of
				  microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse
				  osmosis (RO).
"Membrane module" means the smallest component of a membrane
				  unit in which a specific membrane surface area is housed in a device with a
				  filtrate outlet.
"Membrane technology" means a process that uses a permeable
				  membrane to remove ions, molecules, or particles from the process stream, such
				  as MF, UF, NF, RO, and electrodialysis reversal (EDR).
"Membrane unit" means a group of membrane modules that share
				  common valving that allows the unit to be isolated from the rest of the system
				  for the purpose of integrity testing or other maintenance.
"Method detection limit" or "MDL" means the minimum
				  concentration of a substance that can be measured and reported with 99%
				  confidence that the analyte concentration is greater than zero and is
				  determined from analysis of a sample in a given matrix containing the analyte.
"Microfiltration" or "MF" means a pressure-driven membrane
				  technology that separates particles, based on the pore-size rating of the
				  membrane, from a feed stream by using a sieving mechanism. Typically, MF can
				  remove particles down to 0.1 micrometer in size.
"Most probable number" or "MPN" means the density or number
				  of organisms per unit volume most likely to be present in a water sample and
				  obtained from method-specific statistical MPN tables.
"MPA" means the microscopic particulate analysis method
				  approved by EPA for use in the determination of whether a groundwater is under
				  the influence of surface water.
"Nanofiltration" or "NF" means a pressure-driven membrane
				  technology designed to remove multivalent ions ("softening") and other
				  constituents based on the pore size, which ranges from one to 10 nanometers.
				  Nanofiltration membranes typically operate under a pressure range of 600 to
				  1100 psi.
"Noncommunity waterworks" means a waterworks that is not a
				  community waterworks, but operates at least 60 days out of the year.
"Nonpotable water" means water not classified as pure
				  water.
"Nontransient noncommunity waterworks" or "NTNC" means a
				  waterworks that is not a community waterworks and that regularly serves at
				  least 25 of the same persons over six months out of the year. When used in the
				  context of an NTNC, "regularly serves" means four or more hours per day, for
				  four or more days per week, for 26 or more weeks per year.
"NSF" means NSF International, formerly known as the National
				  Sanitation Foundation. NSF collaborates with ANSI and Canadian authorities on
				  drinking water standards development (NSF/ANSI/CAN).
"One hundred year flood elevation" or "100-year flood
				  elevation" means flood elevation that has a 1.0% probability of being equaled
				  or exceeded in any given year.
"Operating staff" means individuals employed or appointed by
				  an owner to work at a waterworks. Included in this definition are operators,
				  whether or not the operator's license is appropriate for the classification and
				  category of the waterworks, and unlicensed individuals.
"Operator" means any individual with the requisite skills,
				  employed or appointed by any owner, who is designated by the owner to be the
				  person having full responsibility for the waterworks operations and any
				  subordinate operating staff. The individual may be a supervisor, a shift
				  operator, or a substitute in charge, and have duties including testing or
				  evaluation to control waterworks operations. Not included in this definition
				  are superintendents or directors of public works, city engineers, or other
				  municipal or industrial officials whose duties do not include the actual
				  operation or direct supervision of waterworks.
"Optimal corrosion control treatment" means the corrosion
				  control treatment that minimizes the lead and copper concentrations at
				  consumers' taps while ensuring that the treatment does not cause the waterworks
				  to violate any other section of this chapter.
"Optimum fluoride ion concentration" means that fluoride ion
				  concentration recommended by the U.S. Public Health Service for protection from
				  dental caries.
"Owner" means an individual, group of individuals,
				  partnership, firm, association, institution, corporation, governmental entity,
				  or the federal government that supplies or proposes to supply water to any
				  person within the Commonwealth from or by means of any waterworks.
"PAC" means powdered activated carbon.
"PCBs" means polychlorinated biphenyls.
"PER" means a preliminary engineering report.
"Permit" means an authorization granted by the commissioner
				  to construct or operate a waterworks.
"Permitted capacity" means the limiting hydraulic capability
				  of the waterworks, taking into consideration the source water capacity,
				  treatment facilities, finished water storage, delivery, and distribution
				  system.
"Person" means any individual, corporation, partnership,
				  association, cooperative, limited liability company, trust, joint venture,
				  government, political subdivision, or any other legal or commercial entity and
				  any successor, representative, agent, or instrumentality thereof.
"pH" means the negative logarithm of the hydrogen ion
				  concentration of an aqueous solution.
"Physical disconnection" means the removal or absence of
				  pipes, fittings, or fixtures that connect a waterworks directly or indirectly
				  to any other water system.
"Picocurie" or "pCi" means that quantity of radioactive
				  material producing 2.22 nuclear transformations per minute.
"PMCL" means the primary maximum contaminant level of a
				  contaminant based on health considerations.
"Point of disinfectant application" means the point where
				  the disinfectant is applied and water downstream of that point is not subject
				  to recontamination by surface runoff.
"Point-of-entry device" or "POE device" means a treatment
				  device applied to the water entering a house or building for the purpose of
				  reducing contaminants in the water distributed throughout the house or
				  building.
"Point-of-use device" or "POU device" means a treatment
				  device applied to a single tap for the purpose of reducing contaminants in the
				  water at that one tap.
"Pollution" means the presence of any foreign substance
				  (chemical, physical, radiological, or biological) in water that tends to
				  degrade its quality so as to constitute an unnecessary risk to human health or
				  impair the usefulness of the water.
"Potable water" means the same as "pure water."
"Practical quantitation level" or "PQL" means the lowest
				  level that can be reliably measured within specified limits of precision and
				  accuracy during routine laboratory conditions.
"Prechlorination" means the application of chlorine to water
				  before filtration.
"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 water treatment plant.
"Pressure vacuum breaker assembly" means a backflow
				  prevention assembly (i) designed to prevent backsiphonage and used for high
				  hazard or low hazard situations; (ii) composed of an independently operating
				  spring-loaded check valve, an independently operating spring-loaded air-inlet
				  valve, and tightly closing shutoff valves located at each end of the assembly;
				  and (iii) fitted with properly located test cocks to facilitate testing of the
				  assembly.
"Primary disinfection" means disinfection to achieve a
				  desired level of inactivation of targeted pathogenic organisms in water by
				  chemical or physical agents as an integral part of the treatment
				  process.
"Process fluids" means any fluid or solution that may be
				  chemically, biologically, or otherwise contaminated or polluted that would
				  constitute a health, environmental, or system hazard if introduced into the
				  waterworks. This includes (i) polluted or contaminated water; (ii) used waters;
				  (iii) cooling waters; (iv) contaminated natural waters taken from wells, lakes
				  or reservoirs, streams, or irrigation systems; (v) chemicals in solution or
				  suspension; or (vi) oils, gases, acids, alkalis, and other liquid and gaseous
				  fluid used in industrial or other processes.
"Process water" means water used for dissolving dry
				  chemicals; diluting liquid chemicals; and operating chemical feeders, treatment
				  facilities, or equipment.
"Project documents" means the engineer's report, design
				  criteria, preliminary and final plans, specifications, and procurement
				  documents for the construction of new waterworks or modifications to existing
				  waterworks.
"Pure water" means water fit for human consumption that is
				  (i) sanitary and normally free of minerals, organic substances, and toxic
				  agents in excess of reasonable amounts and (ii) adequate in quantity and
				  quality for the minimum health requirements of the persons served.
"QCRV" means the quality control release value used in
				  challenge tests of microfiltration (MF) and ultrafiltration (UF) membrane
				  filters.
"RAA" means running annual average.
"Reduced pressure principle backflow prevention assembly" or
				  "reduced pressure zone backflow prevention assembly" or "RPZ assembly" means an
				  assembly designed to prevent backsiphonage or backpressure backflow and used
				  for high or low hazard situations, composed of two independently operating
				  spring-loaded check valves together with an independent, hydraulically
				  operating pressure differential relief valve located between the two check
				  valves. During normal flow and at the cessation of normal flow, the pressure
				  between these two checks shall be less than the supply pressure. The assembly
				  shall include tightly closing shutoff valves located at each end of the RPZ
				  assembly and shall be fitted with properly located test cocks to facilitate
				  testing of the assembly.
"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 an REM.
"Repeat compliance period" means any subsequent compliance
				  period after the initial compliance period.
"Residual disinfectant concentration" means the
				  concentration of disinfectant measured in mg/L in a representative sample of
				  water.
"Reverse osmosis" or "RO" means a membrane technology
				  designed to remove salts, low-molecular weight solutes, and all other
				  constituents up to 0.0001 micron in size by applying a pressure in excess of
				  osmotic pressure to force water through a semi-permeable membrane from a region
				  of high solution concentration to a region of lower solution
				  concentration.
"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 protective barrier
				  that is already in place.
"Sanitary survey" means an evaluation conducted by the
				  department of a waterworks' water supply, facilities, equipment, operation,
				  maintenance, monitoring records, and overall management to ensure the provision
				  of potable water.
"SDWA" means the Safe Drinking Water Act (42 USC § 300f
				  et seq.) and its amendments.
"Seasonal waterworks" means a noncommunity waterworks that
				  is not operated as a waterworks on a year-round basis, and starts up and shuts
				  down at the beginning and end of each operating season.
"Secondary disinfection" means disinfection by chemical
				  oxidants or equivalent agents applied at the entry point or in the distribution
				  system to provide a residual disinfectant in water to maintain water quality
				  and safeguard against chance contamination from permeation, leaching,
				  intrusion, regrowth, or biofilms.
"Sedimentation" means a process for removal of solids before
				  filtration by gravity or separation.
"Service connection" means the point of delivery of finished
				  water from a waterworks to a consumer's water system, fire protection system,
				  irrigation system, and to all other points where finished water is delivered
				  through the distribution system to a consumer. Generally, the service
				  connection occurs at the water meter, or at the distribution main if no water
				  meter is installed, or in the case of an owner of both the waterworks and the
				  building supplied, the point of entry into the building. Service connections
				  may be permanent, temporary, or emergency.
"Service line" means the pipeline or service pipe between
				  the service connection and the building connection.
"Sewer" means any pipe or conduit used to convey sanitary
				  sewage, stormwater, or industrial waste streams. Combined sewers convey both
				  stormwater and sanitary sewage.
"Significant deficiency" means any defect in a waterworks'
				  design, operation, maintenance, or administration, as well as the failure or
				  malfunction of any waterworks component that may cause or has the potential to
				  cause, an unacceptable risk to health or could affect the reliable delivery of
				  potable water to consumers.
"Single-family structure" means, for the purpose of
				  12VAC5-590-375 B only, a building constructed as a single-family residence that
				  is currently used as either a residence or a place of business.
"Site visit" means a tour of a waterworks by the department
				  or other authorized persons for purposes including assessing and documenting
				  its physical condition, operations, and compliance activities.
"Slow sand filtration" means a process involving passage of
				  source 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.
"SMCL" means the secondary maximum contaminant level of a
				  contaminant. SMCLs are based on aesthetic qualities related to the public
				  acceptance of drinking water.
"SOP" means standard operating procedure.
"Source water" means water as it is pumped or otherwise
				  withdrawn from a well, spring, stream, lake or reservoir, or any body of
				  surface water (natural or impounded), and before any treatment.
"Supervisory control and data acquisition" or "SCADA" means a
				  computer-controlled system used by a waterworks to monitor its operations.
				  Typical design features may be specific to individual waterworks and include
				  alarm, response, control, and data acquisition.
"Surface water" means all water 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 the water. It is a
				  calculated parameter obtained by dividing a sample's ultraviolet absorption at
				  a wavelength of 254 nm (UV254) (in
				  m-1) by its concentration of DOC (in mg/L).
"Synthetic organic chemical" or "SOC" means a man-made
				  organic compound, generally utilized for agriculture or industrial purposes.
				  Table 340.2 lists SOCs regulated as contaminants.
"System hazard" means a condition posing an actual, or
				  threat of, damage to the physical properties of the waterworks or a consumer's
				  water system.
"TDS" means total dissolved solids.
"TMF" means the technical, managerial, and financial
				  capabilities to operate and maintain a waterworks.
"Too numerous to count" or "TNTC" 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
				  milligrams per liter (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.
"Total trihalomethanes" or "TTHM" means the sum of the
				  concentrations of the trihalomethanes (THMs) expressed in milligrams per liter
				  (mg/L) and rounded to two significant figures. For the purpose of this chapter,
				  TTHM shall mean trichloromethane (chloroform), dibromochloromethane,
				  bromodichloromethane, and tribromomethane (bromoform).
"Transient noncommunity waterworks" or "TNC" means a
				  noncommunity waterworks that is not a nontransient noncommunity waterworks
				  (NTNC). A TNC serves at least 25 persons daily for at least 60 days out of the
				  year.
"Treatment" means any process that changes the chemical,
				  physical, radiological, or bacteriological quality of water.
"Treatment technique" or "TT" means a technology or process
				  demonstrated to the satisfaction of the department to lead to a reduction in
				  the level of a specific contaminant sufficient to comply with this
				  chapter.
"Triggered source water monitoring" means monitoring
				  required of any groundwater system as a result of a total coliform-positive
				  sample in the distribution system.
"Trihalomethane" or "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.
"Ultrafiltration" or "UF" means a membrane technology
				  designed to remove particles up to 0.01 micron in size.
"Unconsolidated" means loose sediment that has not been
				  compacted, cemented, lithified, or metamorphosed into rock. Sediment may be
				  derived from a sedimentary-type, igneous-type, metamorphic-type rock, which
				  includes clay, silt, sand, gravel, and mixtures of these particle types.
"Uncovered 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 atmosphere.
"Unregulated contaminant" or "UC" means a contaminant for
				  which a monitoring requirement has been established, but for which no MCL or
				  treatment technique requirement has been established.
"USBC" means the Uniform Statewide Building Code
				  (13VAC5-63).
"Used water" means any water supplied by a waterworks to a
				  consumer's water system after it has passed through the service connection and
				  is no longer under the control of the owner.
"UV" means ultraviolet.
"Variance" means allowing a waterworks that satisfies the
				  criteria in 12VAC5-590-140 to provide drinking water that does not fully comply
				  with this chapter. A PMCL variance is a variance to a primary maximum
				  contaminant level, or a treatment technique requirement. An operational
				  variance is a variance to an operational regulation or a SMCL.
"Virus" means a virus of fecal origin that is infectious to
				  humans by waterborne transmission and must be preemptively inactivated through
				  disinfection before human consumption.
"Volatile organic chemical" or "VOC" means an organic
				  compound generally characterized by its low molecular weight and its tendency
				  to vaporize rapidly at relatively low temperatures and pressures. Table 340.2
				  lists VOCs regulated as contaminants.
"VOSH" means the Virginia Occupational Safety and Health
				  program.
"Waiver" means permission from the department to deviate
				  from the monitoring and reporting requirements in this chapter for a specific
				  contaminant.
"Waterborne disease outbreak" means the significant
				  occurrence of acute infectious illness, epidemiologically associated with the
				  ingestion of water from a waterworks that is deficient in treatment, as
				  determined by the commissioner or the State Epidemiologist.
"Water supply" means the source of water taken into a
				  waterworks including wells, streams, springs, lakes or reservoirs, and other
				  bodies of surface waters (natural or impounded), and the tributaries thereto,
				  and all impounded groundwater. The term "water supply" shall not include any
				  waters above the point of intake of the waterworks.
"Water treatment plant" means that portion of a waterworks
				  intended specifically for water treatment; it may include, among other
				  operations, coagulation, sedimentation, filtration, and disinfection.
"Waterworks" means a system that serves piped water for
				  human consumption to at least 15 service connections or 25 or more individuals
				  for at least 60 days out of the year.
"Waterworks" includes all structures, equipment, and
				  appurtenances used in the storage, collection, purification, treatment, and
				  distribution of potable water except the piping and fixtures inside the
				  building where such water is delivered.
"Waterworks business operation plan" means the same as
				  "comprehensive business plan."
"Wholesale waterworks" means a waterworks that treats source
				  water as necessary to produce potable water and then delivers some or all of
				  that potable water to another waterworks. Delivery may be through a direct
				  connection or through the distribution system of one or more consecutive
				  waterworks.