A pre-coat cake of diatomaceous earth filter media is deposited on a support membrane (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.
“Direct filtration" means a series of processes including coagulation and filtration, but excluding sedimentation, resulting in substantial particulate removal.
“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 where residual disinfectant concentration (“C") is measured. Where more than one “C" is measured, “T" is:
For the first measurement of “C", the time in minutes that it takes for water to move from the first or only point of disinfectant application to a point before or at the point where the first “C" is measured; and
For subsequent measurements of “C", the time in minutes that it takes for water to move from the previous “C" measurement point to the “C" measurement point for which the particular “T" is being calculated. Disinfectant contact time in pipelines is calculated based on “plug flow" by dividing the internal volume of the pipe by the maximum hourly flow rate through the pipe. Disinfectant contact time within mixing basins and storage reservoirs shall be determined by tracer studies or other department approved equivalent demonstration.
“Disinfection" means a process which inactivates pathogenic organisms in water by chemical oxidants or equivalent agents.
“Disinfection profile" means a summary of daily Giardia lamblia
inactivation through the treatment plant. The procedure for developing a disinfection profile is contained in s. NR 810.32
“Distribution system" means all pipes or conduits by which water is delivered to consumers except piping and fixtures inside buildings served, water services and private water mains as defined in ch. SPS 381
“Domestic or other non-distribution system plumbing problem" means a coliform contamination problem in a public water system with more than one service connection that is limited to the specific service connection from which the coliform-positive sample was taken.
“Dose equivalent" means the product of the absorbed dose for 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 (ICRUM).
“Dual purpose sample" means a repeat coliform sample collected at the groundwater source to meet requirements for both triggered source water monitoring, and repeat coliform monitoring following a routine positive distribution sample. It is only allowed at groundwater systems serving a population of less than 1,000 people.
“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).
“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.
“Effective corrosion inhibitor residual" means a concentration sufficient to form a protective coating on the interior walls of a pipe.
“Entry point" means a location in the public water system after treatment or chemical addition, if any, but prior to the distribution system. A sample collected in the distribution system may be considered an entry point sample if the department has determined it is more representative of the water sources.
“Environmental protection agency" or “EPA" means the agency of the United States federal government ultimately responsible for establishing and enforcing national primary drinking water regulations.
“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.
“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 public water system and is intended for distribution and consumption without further treatment, except as treatment necessary to maintain water quality in the distribution system, for example booster disinfection or addition of corrosion control chemicals.
“First draw sample" means a one-liter sample of tap water that has been standing in plumbing pipes at least 6 hours and is collected without flushing the tap.
“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.
“4 log treatment of viruses" means a treatment process or a combination of treatment processes that provides inactivation or removal of 99.99% of viruses.
“GAC10" means granular activated carbon filter beds with an empty-bed contact time of 10 minutes based on average daily flow and a carbon reactivation frequency of every 180 days, except that the reactivation frequency of GAC10 used as a best available technology for compliance with MCLs at LRAA monitoring locations is every 120 days.
“GAC20" means granular activated carbon filter beds with an empty-bed contact time of 20 minutes based on average daily flow and a carbon reactivation frequency of every 240 days.
“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 under the direct influence of surface water"(GWUDI) means any water beneath the surface of the ground with:
Occurrence of insects or other macroorganisms, algae or large diameter pathogens such as Giardia lamblia
in greater than or equal to 10% of representative source water samples collected over a period of 6 months, immediately prior to the first or only point of disinfectant application, or
Evidence of relatively rapid shifts in water characteristics such as turbidity, temperature, conductivity, or pH which closely correlate to climatological or surface water conditions where the department determines that these shifts are indications of the potential for contamination of the groundwater by the organisms identified in par. (a)
“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 2 significant figures after addition.
“Holding time" means the period from time of sampling to time of analysis.
“Human consumption" means drinking; bathing, including all personal hygiene needs in a home, business, or school setting; showering; hand washing; cooking; dishwashing; and maintaining oral hygiene.
“Initial compliance period" means the first full 3-year compliance period which begins at least 18 months after promulgation of the federal regulations. For monitoring contaminants in ss. NR 809.11 (2)
and 809.20 (1)
, the initial compliance period means January 1993 — December 1995 for public water systems with 150 or more service connections and January 1996 — December 1998 for public water systems having fewer than 150 service connections.
“Initial Distribution System Evaluation or “IDSE" means an evaluation using monitoring to determine locations with representative high TTHM and HAA5 concentrations throughout the distribution system of a public water system.
“Large water system" means, for the purpose of monitoring lead and copper, a public water system that serves more than 50,000 persons.
“Lead service line" means a service line made of lead which connects the water main to the building inlet and any lead pigtail, gooseneck or other fitting which is connected to such lead line.
“Learns of the violation" for the purpose determining public notification timing requirements under subch. VII
means any of the following:
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.