Wisconsin Administrative Code › Department of Natural Resources › NR 800 - Environmental Protection - Water Supply › Chapter NR 809 - Safe Drinking Water › Section NR 809.04 - Definitions

Current through June 24, 2024
In this chapter:
(1) "Action level" is the concentration of
				lead or copper in water which determines, in some cases, the treatment
				requirements that a public water system is required to complete.
(2) "Best available technology" or "BAT"
				means the best technology treatment techniques, or other means which the U.S.
				environmental protection agency finds, after examination for efficacy under
				field conditions and not solely under laboratory conditions, are available,
				taking cost into consideration.
(2g) "Circuit rider" means a roving technical
				expert employed by a state rural water association to provide training and
				assistance to rural and small water utilities within the state.
(2r) "Clean compliance history" means a
				record of no
E. coli
MCL violations under s. NR 809.31; no
				monitoring violations under s. NR 809.312; and no coliform treatment technique
				trigger exceedances or treatment technique violations under s. NR
				809.313.
(3) "Coagulation" means a
				process using coagulant chemicals and mixing by which colloidal and suspended
				materials are destabilized and agglomerated into flocs.
(4) "Combined distribution
				system
"
means an interconnected distribution system consisting
				of the distribution systems of wholesale systems and of the consecutive systems
				that receive finished water.
(5)
				"Community water system" or "CWS" means a public water system which serves at
				least 15 service connections used by year-round residents or regularly serves
				at least 25 year-round residents. Any public water system serving 7 or more
				homes, 10 or more mobile homes, 10 or more apartment units, or 10 or more
				condominium units is a community water system unless information is available
				to indicate that 25 year-round residents will not be served.
(6) "Compliance cycle" means the 9-year
				calendar year cycle during which public water systems monitor. Each compliance
				cycle consists of 3, 3 year compliance periods. The first compliance cycle
				begins January 1, 1993 and ends December 31, 2001; the second begins January 1,
				2002 and ends December 31, 2010; the third begins January 1, 2011 and ends
				December 31, 2019.
(7) "Compliance
				period" means a 3-year calendar year period within a compliance cycle. Each
				compliance cycle has 3, 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; the third from
				January 1, 1999 to December 31, 2001.
(8) "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 this chapter, the comprehensive performance
				evaluation consists of at least the following components: Assessment of plant
				performance; evaluation of major unit processes; identification and
				prioritization of performance limiting factors; assessment of the applicability
				of comprehensive technical assistance; and preparation of a CPE
				report.
(9) "Confirmed presence"
				means the presence of coliform bacteria in a water sample confirmed by a total
				coliform-positive repeat sample.
(10) "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.
(11) "Consecutive System" means a public
				water system that receives some or all of its finished water from one or more
				wholesale systems through a master metering system. This public water system
				may also be known as a wholesale purchaser or wholesale customer. Delivery may
				be through a direct connection or through the distribution system of one or
				more consecutive systems.
(12)
				"Conventional filtration treatment" means a series of processes including
				coagulation, flocculation, sedimentation, and filtration resulting in
				substantial particulate removal.
(13) "Contaminant" means any physical,
				chemical, biological, or radiological substance or matter in water.
(14) "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.
(15)
				"CT" or "CTcalc" is the product of the residual disinfectant concentration (C)
				in mg/l determined before or at the first customer, and the corresponding
				disinfectant contact time (T) in minutes, i.e., "C" x "T". If a public water
				system applies disinfectants at more than one point prior to the first
				customer, it shall determine the CT of each disinfectant sequence before or at
				the first customer, to determine the total percent inactivation or "total
				inactivation ratio." The inactivation ratio for a single disinfectant sequence
				is:
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where "CTtable" is the CT value
				  required for the target organism and the target level of inactivation as
				  contained in ss. NR 810.47 to 810.61. The sum of the inactivation ratios, or
				  total inactivation ratio for a series of disinfection sequences is:
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and is calculated by adding together the inactivation ratio
				  for each disinfection sequence. In determining the total inactivation ratio,
				  the water supplier determines the residual disinfectant concentration of each
				  sequence and corresponding contact time before any subsequent disinfection
				  application points. A total inactivation ratio equal to or greater than 1.0 is
				  assumed to provide the target level of disinfection of the target
				  organism.
(16) "Department"
				means the department of natural resources.
(17) "Diatomaceous earth filtration" means a
				process resulting in substantial particulate removal in which:
(a) A pre-coat cake of diatomaceous earth
				filter media is deposited on a support membrane (septum); and
(b) While the water is filtered by passing
				through the cake on the septum, additional filter media known as body feed is
				continuously added to the feed water to maintain the permeability of the filter
				cake.