Definitions

For the purpose of this chapter the following definitions shall apply: 1. "Action level" means the concentration of lead or copper in water specified in title 40 Code of Federal Regulations part 141, subpart I, section 141.80(c), that determines, in some cases, the treatment requirements set forth under title 40 Code of Federal Regulations part 141, subpart I, that a water system is required to complete. 2. "Bag filters" means pressure-driven separation devices that remove particulate matter larger than one micrometer using an engineered porous filtration media. They 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 the outside. 3. "Bank filtration" means a water treatment process that uses a well to recover surface water that has naturally infiltrated into ground water through a riverbed or riverbanks. Infiltration is typically enhanced by the hydraulic gradient imposed by a nearby pumping water supply or other wells. 4. "Best available technology" or "BAT" means the best technology, treatment techniques, or other means which the department finds, after examination for efficacy under field conditions and not solely under laboratory conditions, are available (taking cost into consideration). For the purposes of setting maximum contaminant levels for synthetic organic chemicals, any best available technology must be at least as effective as granular activated carbon. 5. "Cartridge filters" means pressure-driven separation devices that remove particulate matter larger than one micrometer using an engineered porous filtration media. They are typically constructed as rigid or semirigid, self-supporting filter elements housed in pressure vessels in which flow is from the outside of the cartridge to the inside. 6. "Clean compliance history", for the purposes of subpart Y, means a record of no MCL violations as specified in title 40 Code of Federal Regulations part 141.63; no monitoring violations as specified in title 40 Code of Federal Regulations part 141.21 or as specified in title 40 Code of Federal Regulations part 141, subpart Y; and no coliform treatment technique trigger exceedances or treatment technique violations as specified in title 40 Code of Federal Regulations part 141, subpart Y. 7. "Coagulation" means a process using coagulant chemicals and mixing by which colloidal and suspended materials are destabilized and agglomerated into flocs. 8. "Combined distribution system" means the interconnected distribution system consisting of the distribution systems of wholesale systems and of the consecutive systems that receive finished water. 9. "Community water system" means a public water system which serves at least fifteen service connections used by year-round residents or regularly serves at least twenty-five year-round residents. 10. "Compliance cycle" means the nine-year calendar year cycle during which public water systems must monitor for inorganic and organic chemicals excluding lead, copper, trihalomethanes, and unregulated contaminants. Each compliance cycle consists of three 3-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; and the third begins January 1, 2011, and ends December 31, 2019. 11. "Compliance period" means a three-year calendar year period within a compliance cycle during which public water systems must monitor for inorganic and organic chemicals excluding lead, copper, trihalomethanes, and unregulated contaminants. Each compliance cycle has three 3-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. 12. "Composite correction program" or "CCP" means a systematic, comprehensive procedure for identifying, prioritizing, and remedying factors that limit water treatment plant performance as set forth in the United States environmental protection agency handbook entitled Optimizing Water Treatment Plant Performance Using The Composite Correction Program, EPA/625/6-91/027, 1998 edition. A composite correction program consists of two phases, a comprehensive performance evaluation and comprehensive technical assistance. 13. "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. For purposes of compliance with title 40 Code of Federal Regulations part 141, subpart P and subpart T, the comprehensive performance evaluation shall consist of at least the following components: a. Assessment of plant performance; b. Evaluation of major unit processes; c. Identification and prioritization of performance limiting factors; d. Assessment of the applicability of comprehensive technical assistance; and e. Preparation of a comprehensive performance evaluation report. 14. "Comprehensive technical assistance" or "CTA" means the performance improvement phase of a composite correction program that is implemented if the comprehensive performance evaluation results indicate improved performance potential. During the comprehensive technical assistance phase, identified and prioritized factors that limit water treatment plant performance are systematically addressed and eliminated. 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. "Consecutive system" means 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. 17. "Contaminant" means any physical, chemical, biological, or radiological substance or matter in water. 18. "Conventional filtration treatment" means a series of processes, including coagulation, flocculation, sedimentation, and filtration resulting in substantial particulate removal. 19. "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. 20. "Cross connection" means any connection or arrangement between two otherwise separate piping systems, one of which contains potable water and the other either water of unknown or questionable safety or steam, gas, or chemical whereby there may be a flow from one system to the other, the direction of flow depending on the pressure differential between the two systems. 21. "CT" or "CT calc" means the product of residual disinfectant concentration (C) in milligrams per liter determined before or at the first customer and the corresponding disinfectant contact time (T) in minutes. If disinfectants are applied, at more than one point prior to the first customer, the CT of each disinfectant sequence must be determined before or at the first customer to determine the total percent inactivation or total inactivation ratio. In determining the total inactivation ratio, the residual disinfectant concentration of each disinfection sequence and the corresponding contact time must be determined before any subsequent disinfection application points. CT ninety-nine and nine-tenths is the CT value required for ninety-nine and nine-tenths percent (three-logarithm) inactivation of giardia lamblia cysts. CT ninety-nine point nine values for a wide variety of disinfectants and conditions are set forth under title 40 Code of Federal Regulations part 141, subpart H. CT calculated divided by CT ninety-nine and nine-tenths is the inactivation ratio. The total inactivation ratio is determined by adding together the inactivation ratio for each disinfection sequence. A total inactivation ratio equal to or greater than one point zero is assumed to provide a three-logarithm inactivation of giardia lamblia cysts. 22. "Department" means the department of environmental quality. 23. "Diatomaceous earth filtration" means a process resulting in substantial particulate removal in which a precoat cake of diatomaceous earth filter media is deposited on a support membrane or septum, and 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 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 C is measured. Where more than one C is measured, T, for the first measurement of C, is the time in minutes that it takes the 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. For subsequent measurements of C, T is 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 by dividing the internal volume of the pipe by the maximum hourly flow rate through that pipe. T 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" means a summary of daily giardia lamblia inactivation through the treatment plant. The disinfection profile shall be developed as set forth under title 40 Code of Federal Regulations part 141, subpart P (141.172) and subpart T (141.530-141.536). 29. "Domestic or other nondistribution 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. 30. "Dual sample set" means a set of two samples collected at the same time and same location, with one sample analyzed for total trihalomethanes (TTHM) and the other sample analyzed for haloacetic acids five (HAA5). Dual sample sets are collected for the purpose of conducting an initial distribution system evaluation (IDSE) under title 40 Code of Federal Regulations parts 141.600 to 141.605 inclusive, and determining compliance with the TTHM and HAA5 MCLs under title 40 Code of Federal Regulations parts 141.620 to 141.629 inclusive. 31. "Effective corrosion inhibitor residual", for the purpose of title 40 Code of Federal Regulations part 141, subpart I only, means a concentration sufficient to form a passivating film on the interior walls of pipe. 32. "Enhanced coagulation" means the addition of sufficient coagulant for improved removal of disinfection byproduct precursors by conventional filtration treatment. 33. "Enhanced softening" means the improved removal of disinfection byproduct precursors by precipitative softening. 34. "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 startup to backwash inclusively, that includes an assessment of filter performance while another filter is being backwashed. 35. "Filtration" means a process for removing particulate matter from water by passage through porous media. 36. "Finished water" means water that is introduced into the distribution system of a public water system and is intended for distribution and consumption without further treatment, except treatment necessary to maintain water quality in the distribution system (e.g., booster disinfection or addition of corrosion control chemicals). 37. "First draw sample" means a one-liter sample of tap water, collected in accordance with title 40 Code of Federal Regulations part 141, section 141.86(b)(2), that has been standing in plumbing pipes at least six hours and is collected without flushing the tap. 38. "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. 39. "Flowing stream" means a course of running water flowing in a definite channel. 40. "Granular activated carbon ten" or "GAC10" means granular activated carbon filter beds with an empty-bed contact time of ten minutes based on average daily flow and a carbon reactivation frequency of every one hundred eighty days, except that the reactivation frequency for GAC10 used as a best available technology for compliance with subpart V MCLs under title 40 Code of Federal Regulations part 141.64(b)(2) shall be one hundred twenty days. 41. "Granular activated carbon twenty" or "GAC20" means granular activated carbon filter beds with an empty-bed contact time of twenty minutes based on average daily flow and a carbon reactivation frequency of every two hundred forty days. 42. "Gross alpha particle activity" means the total radioactivity due to alpha particle emission as inferred from measurements on a dry sample. 43. "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. Ground water under the direct influence of surface water also means significant and relatively rapid shifts in water characteristics such as turbidity, temperature, conductivity, or pH which closely correlate to climatological or surface water conditions. 44. "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. 45. "Halogen" means one of the chemical elements chlorine, bromine, or iodine. 46. "Initial compliance period" means the first full compliance period that begins January 1, 1993, during which public water systems must monitor for inorganic and organic chemicals excluding lead, copper, trihalomethanes, and unregulated contaminants. 47. "Lake/reservoir" means a natural or manmade 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. 48. "Large water system", for the purpose of title 40 Code of Federal Regulations part 141, subpart I only, means a water system that serves more than fifty thousand persons. 49. "Lead service line" means a service line made of lead that connects the water main to the building inlet and any pigtail, gooseneck, or other fitting that is connected to a lead line. 50. "Legionella" means a genus of bacteria, some species of which have caused a type of pneumonia called legionnaires disease. 51. "Level 1 assessment" means an evaluation to identify the possible presence of sanitary defects, defects in distribution system coliform monitoring practices, and, when possible, the likely reason that the system triggered the assessment. 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, such as whether a ground water system is disinfected; existing water quality monitoring data; and inadequacies in sample sites, sampling protocol, and sampling processing. The system must conduct the assessment consistent with any state 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. 52. "Level 2 assessment" means an evaluation to identify the possible presence of sanitary defects, defects in distribution system coliform monitoring practices, and, when possible, the likely reason that the system triggered the assessment. A level 2 assessment provides a more detailed examination of the system, including the system's monitoring and operational practices, than does a level 1 assessment through the use of more comprehensive investigation and review of available information, additional internal and external resources, and other relevant practices. It is conducted by an individual approved by the state, 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, such as 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 state 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 state in the case of an E. coli MCL violation. 53. "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. 54. "Maximum contaminant level" or "MCL" means the maximum permissible level of a contaminant in water which is delivered to any user of a public water system. 55. "Maximum residual disinfectant level" or "MRDL" means a level of a disinfectant added for water treatment that must not be exceeded at the consumer's tap without an unacceptable possibility of adverse health effects. 56. "Maximum total trihalomethane potential" means the maximum concentration of total trihalomethanes produced in a given water containing a disinfectant residual after seven days at a temperature of twenty-five degrees Celsius [77 degrees Fahrenheit] or above. 57. "Medium-size water system", for the purpose of title 40 Code of Federal Regulations part 141, subpart I only, means a water system that serves three thousand three hundred one to fifty thousand persons. 58. "Membrane filtration" means a pressure-driven 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 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. 59. "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 water transport time within the distribution system. 60. "Noncommunity water system" means a public water system that is not a community water system that primarily provides service to other than year-round residents. A noncommunity water system is either a "nontransient noncommunity" or "transient noncommunity" water system. 61. "Nontransient noncommunity water system" means a noncommunity water system that regularly serves at least twenty-five of the same persons over six months per year. 62. "Optimal corrosion-control treatment", for the purpose of title 40 Code of Federal Regulations part 141, subpart I only, means the corrosion-control treatment that minimizes the lead and copper concentrations at users' taps while ensuring that the treatment does not cause the water system to violate any national primary drinking water regulations. 63. "Person" means an individual, corporation, company, association, partnership, municipality, or any other entity. 64. "Plant intake" means 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. 65. "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 water runoff. 66. "Point-of-entry treatment device" means 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. 67. "Point-of-use treatment device" means a treatment device applied to a single tap used for the purpose of reducing contaminants in drinking water at that one tap. 68. "Potable water" means water free from impurities in amounts sufficient to cause disease or harmful physiological effects, with the physical, chemical, biological, or radiological quality conforming to applicable maximum permissible contaminant levels. 69. "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 treatment plant. 70. "Product" means any chemical or substance added to a public water system, any materials used in the manufacture of public water system components or appurtenances, or any pipe, storage tank, valve, fixture, or other materials that come in contact with water intended for use in a public water system. 71. "Public water system" means a system for the provision to the public of water for human consumption through pipes or other constructed conveyances, if such system has at least fifteen service connections or regularly serves at least twenty-five individuals sixty or more days out of the year. A public water system includes any collection, treatment, storage, and distribution facilities under control of the operator of the system and used primarily in connection with the system; and, any collection or pretreatment storage facilities that are not under control of the operator which are used primarily in connection with the system. A public water system does not include systems that provide water through pipes or constructed conveyances other than pipes that qualify for the exclusions set forth under section 1401(4)(B)(i) and (ii) of the federal Safe Drinking Water Act [42 U.S.C. 300f(4)(B)(i) and (ii)]. A public water system is either a "community" or a "noncommunity" water system. 72. "Repeat compliance period" means any subsequent compliance period after the initial compliance period during which public water systems must monitor for inorganic and organic chemicals excluding lead, copper, trihalomethanes, and unregulated contaminants. 73. "Residual disinfectant concentration" (C in CT calculations) means the concentration of disinfectant measured in milligrams per liter in a representative sample of water. 74. "Sampling schedule" means the frequency required for submitting drinking water samples to a certified laboratory for examination. 75. "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. 76. "Sanitary survey" means an onsite review of the water source, facilities, equipment, operation, and maintenance of a public water system for the purpose of evaluating the adequacy of such source, facilities, equipment, operation, and maintenance for producing and distributing safe drinking water. 77. "Seasonal system" means a noncommunity 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. 78. "Sedimentation" means a process for removal of solids before filtration by gravity or separation. 79. "Service line sample" means a one-liter sample of water, collected in accordance with title 40 Code of Federal Regulations part 141, section 141.86(b)(3), that has been standing for at least six hours in a service line. 80. "Single-family structure", for the purpose of title 40 Code of Federal Regulations part 141, subpart I only, means a building constructed as a single-family residence that is currently used either as a residence or a place of business. 81. "Slow sand filtration" means a process involving passage of raw water through a bed of sand at low velocity resulting in substantial particulate removal by physical and biological mechanisms. 82. "Small water system", for the purpose of title 40 Code of Federal Regulations part 141, subpart I only, means a water system that serves three thousand three hundred or fewer persons. 83. "Specific ultraviolet absorption" or "SUVA" means specific ultraviolet absorption at two hundred fifty-four nanometers, 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 two hundred fifty-four nanometers in meters to the minus one by its concentration of dissolved organic carbon, the fraction of the total organic carbon that passes through a zero point four five micrometer pore diameter filter, in milligrams per liter. 84. "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 title 40 Code of Federal Regulations part 141, subpart H. 85. "Supplier of water" means any person who owns or operates a public water system. 86. "Surface water" means all water which is open to the atmosphere and subject to surface runoff. 87. "System with a single service connection" means a system which supplies drinking water to consumers with a single service line. 88. "Too numerous to count" means that the total number of bacterial colonies exceeds two hundred on a forty-seven millimeter membrane filter used for coliform detection. 89. "Total organic carbon" 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. 90. "Total trihalomethanes" means the sum of the concentration in milligrams per liter of the trihalomethane compounds (trichloromethane [chloroform], dibromochloromethane, bromodichloromethane, and tribromomethane [bromoform]), rounded to two significant figures. 91. "Transient noncommunity water system" means a noncommunity water system that primarily provides service to transients. 92. "Trihalomethane" 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. 93. "Two-stage lime softening" means a process in which chemical addition and hardness precipitation occur in each of two distinct unit clarification processes in series prior to filtration. 94. "Uncovered finished water storage facility" means 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. 95. "Virus" means a virus of fecal origin which is infectious to humans by waterborne transmission. 96. "Water system" means all sources of water and their surroundings and includes all structures, conducts, and appurtenances by means of which the water is collected, treated, stored, or delivered. 97. "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 appropriate local or state agency. 98. "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 consecutive systems.