The date that a laboratory notifies a water supplier of results demonstrating exceedances of MCLs, MRDLs, or action levels.
The day after a specified deadline in NR 809, for violation of deadlines that are not related to MCL, MRDL or action level exceedances.
The date on which the violation, incident, or condition occurred, for any other type of violation, incident, or condition requiring public notification.
The date specified in writing by the department to the water supplier.
means a genus of bacteria, some species of which have caused a type of pneumonia called Legionnaires disease.
“Level 1 assessment"
means an evaluation to identify the possible presence of sanitary defects, defects in distribution system coliform monitoring practices, and, when possible, the likely reason that the system triggered the assessment. It is triggered by total coliform detections under s. NR 809.31
. It is conducted by the system operator or owner.
“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 department, which may include the system operator.
“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.
“Long term 2 surface water treatment rule" or “LT2" means the monitoring and requirements under the federal rule 40 CFR part 141
“Man-made beta particle and photon emitters" means all radionuclides emitting beta particles or photons, or both, listed in Maximum Permissible Body Burdens and Maximum Permissible Concentration of Radionuclides in Air or Water for Occupational Exposure, NBS Handbook 69, except the daughter products of thorium-232, uranium-235 and uranium-238.
“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.
“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 which allows an adequate margin of safety. Maximum contaminant level goals are non-enforceable health goals, unless the department determines that action is necessary to protect public health.
“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 which 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.
“Medium-size water system" means, for the purpose of monitoring lead and copper, a public water system that serves greater than 3,300 and less than or equal to 50,000 persons.
“Near the first service connection" means at one of the 20% of all service connections in the entire distribution system that are nearest the water supply treatment facility or water supply source, as measured by water transport time within the distribution system.
“Non-community water system" or “NCWS" means a public water system that is not a community water system. A non-community water system is either a non-transient non-community water system or a transient non-community water system.
“Non-transient non-community water system" or “NTNCWS" means a non-community water system that regularly serves at least 25 of the same persons over 6 months per year.
NR 809.04 Note
Note: Examples of non-transient non-community water systems include those serving schools, day care centers and factories.
“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 public water system to violate any national primary drinking water regulations as listed in 40 CFR part 141
Perfluoroalkyl and polyfluoroalkyl substances” or “PFAS” means a large group of human-made chemicals that are part of the synthetic organic contaminants classification.
“Performance evaluation sample" means a reference sample provided to a laboratory for the purpose of demonstrating that the laboratory can successfully analyze the sample within limits of performance specified by the department. The true value of the concentration of the reference material is unknown to the laboratory at the time of the analysis.
NR 809.04 Note
Note: Performance evaluation samples are also known as proficiency testing samples.
“Person" means an individual, corporation, company, association, cooperative, trust, institution, partnership, state, municipality, or federal agency.
“Picocurie" or “pCi" means that quantity of radioactive material producing 2.22 nuclear transformations per minute.
“Plant" means any facility for the obtainment of potable water, whether from surface water or groundwater sources, for a community water system.
“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 runoff.
“Point-of-entry treatment device" or “POE" is a water 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.
“Point-of-use treatment device" or “POU" is a water treatment device applied to a single tap used for the purpose of reducing contaminants in drinking water at that one tap.
“Primary maximum contaminant levels" means those maximum contaminant levels which represent minimum public health standards.
“Public water system"or “PWS" means a system for the provision to the public of piped water for human consumption through pipes or other constructed conveyances, if the system has at least 15 service connections or regularly serves an average of at least 25 individuals daily at least 60 days out of the year. A public water system is either a “community water system" or a “non-community water system." A public water system:
Includes any collection, treatment, storage and distribution facilities under control of the water supplier for the public water system and used primarily in connection with the system.
Includes any collection or pretreatment storage facilities not under the control of the water supplier for the public water system, which are used primarily in connection with the system.
NR 809.04 Note
The definition of public water system as regulated by this chapter is broader and includes more water systems than those governed by the public service commission under its definition of a public utility in ch. 196
“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.
“Repeat compliance period" means any subsequent compliance period after the initial compliance period.
“Residual disinfectant concentration" (“C" in CT calculations) means the concentration of disinfectant measured in mg/l in a representative sample of water.
“Running annual average" means the sum of 1, 2, 3, or 4 calendar quarter sample results divided by 4. The first sample may be the average of the initial and confirmation sample results. If more than 4 calendar quarters of samples have been collected in more than 4 consecutive calendar quarters, the results from the 4 most recent quarters are used. If multiple compliance samples are collected in a single calendar quarter, the sample which yielded the highest concentration is used to calculate the running annual average. If a quarterly sample is not taken within a required consecutive quarter then the divisor is the number of quarterly samples that have been analyzed within the required time period.
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.
“Sanitary survey" means an on-site inspection of the water source, facilities, equipment, operation and maintenance of a public water system for the purpose of evaluating the adequacy of the source, facilities, equipment, operation and maintenance for producing and distributing safe drinking water.
means a non-community water system that is not operated as a public water system on a year-round basis and that starts up and shuts down at the beginning and end of each operating season.
“Secondary drinking water standards" means those standards for aesthetic parameters which represent minimum public welfare concerns but do not represent health standards.
“Sedimentation" means a process for removal of solids before filtration by gravity or separation.
“Serves or serving" means provides or providing the opportunity for human consumption.
“Service line sample" means a one-liter sample of water that has been standing for at least 6 hours in a service line.
“Significant deficiency" includes, but is not limited to, defects in design, operation, or maintenance of a public water system, or a failure or malfunction of the water sources, treatment, storage or distribution system of a public water system that the department determines to be causing the introduction of contamination into the water delivered to consumers or when the department determines that a health risk exists to consumers of the water.
“Single family structure" means a building constructed as a single-family residence that is currently used as either a residence or a place of business.
“Slow sand filtration" means a process involving passage of raw water through a bed of sand at low velocity, generally less than 0.4 m/h, resulting in substantial particulate removal by physical and biological mechanisms.
“Small water system" means, for the purposes of monitoring lead and copper, a public water system that serves 3,300 persons or fewer.
“Special irrigation district" means an irrigation district in existence prior to May 18, 1994 that provides primarily agricultural service through a piped water system with only incidental residential or similar use where the system or the residential or similar users of the system are supplied with water that meets all maximum contaminant levels of subch. I
“Stage 1 Disinfection Byproducts" or “Stage 1 DBP" means the compliance requirements under the federal rule 40 CFR part 141
“Stage 2 Disinfection Byproducts" or “Stage 2 DBP" means the compliance requirements under the federal rule 40 CFR part 141
“Surface water" means all water which is open to the atmosphere and subject to surface runoff.
“Surface water systems" means public water systems using surface water or groundwater under the direct influence of surface water as a source and that are subject to the requirements of 40 CFR 141
, subpart H, which contains the national primary drinking water regulations.
“SUVA" means specific ultraviolet absorption at 254 nanometers (nm).
NR 809.04 Note
Note: SUVA is an indicator of the humic content of water. It is a calculated parameter obtained by dividing a sample's ultraviolet absorption at a wavelength of 254 nm (UV254) (measured in m-1) by its concentration of dissolved organic carbon (DOC) (in mg/L).
“System with a single service connection" means a public water system which supplies drinking water to consumers via a single service line.
“Too numerous to count" means that the total number of bacterial colonies exceeds 200 on a 47-mm diameter membrane filter used for coliform detection.
“Total organic carbon" or “TOC" means total organic carbon in mg/L measured using heat, oxygen, ultraviolet irradiation, chemical oxidants or combinations of these oxidants that convert organic carbon to carbon dioxide, rounded to 2 significant figures.
“Transient non-community water system" or “TNCWS" means a non-community water system that serves at least 25 people at least 60 days of the year but does not regularly serve at least 25 of the same persons over 6 months per year.
NR 809.04 Note
Note: Examples of transient non-community water systems include those serving taverns, motels, restaurants, churches, campgrounds and parks.
“Virus" means a virus of fecal origin which is infectious to humans by waterborne transmission.
“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 or is supplied from a contaminated source, as determined by the department or other local or state agency.
“Water supplier" means any person who owns or operates a public water system.
“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.
“Year-round resident" means a resident who resides in the same living unit for 6 months per year or more.
NR 809.04 History
History: CR 09-073
: cr. Register November 2010 No. 659
, eff. 12-1-10; corrections in (43) made under s. 13.92 (4) (b) 7.
, Stats., Register November 2010 No. 659
; correction in (22) made under s. 13.92 (4) (b) 7.
, Stats., Register February 2012 No. 674
; correction in (59) made under s. 13.92 (4) (b) 7.
, Stats., Register January 2013 No. 685
; CR 15-049
: cr. (2g), (2r), am. (5) to (8), (15), (19) (b), cr. (24m), am. (37), cr. (37m), (42m), (46m), (47g), (47r), am. (52), cr. (59m), am. (71), cr. (71m), (72m), (74m), renum. (93) to (89m), cr. (93) Register March 2016 No. 723
, eff. 4-1-16; correction in (46m) made under s. 35.17
, Stats., Register March 2016 No. 723
; CR 21-088: cr. (59h) Register July 2022 No. 799, eff. 8-1-22.
NR 809.05 Coverage.
This chapter applies to each public water system, unless the public water system meets all of the following conditions:
Consists only of distribution and storage facilities and does not have any collection or treatment facilities.
Obtains all of its water from, but is not owned or operated by, a public water system to which the regulations in this chapter apply.
NR 809.06 General requirements.
Water suppliers shall conduct the minimum monitoring required by this chapter. The department may increase any monitoring requirements in this chapter, if the department determines that any increase is necessary to protect public health, safety or welfare. The department may require additional monitoring and analysis when necessary to verify water quality, treatment effectiveness, or to ensure representative sampling throughout an entire distribution system. The department may decrease any monitoring requirements in this chapter, if the department determines that such a decrease will not adversely affect protection of public health, safety or welfare.
subch. I of ch. NR 809
Subchapter I — Maximum Contaminant Levels, Monitoring and Analytical Requirements for Primary Drinking Water Contaminants
NR 809.07 Maximum contaminant level goals for primary contaminants. NR 809.07(1)(1)
Maximum contaminant level goals (MCLGs) are zero for the following contaminants: