Wis. Admin. Code Department of Natural Resources NR 810.09

Current through November 25, 2024
Section NR 810.09 - General treatment and disinfection requirements

Department approved treatment shall be provided and operated by each water supplier where necessary in order to ensure that the finished water supplied to consumers meets the primary maximum contaminant levels contained in ch. NR 809 and the design standards contained in ch. NR 811, where applicable. In addition, all of the following requirements shall be met:

(1) CHEMICAL TREATMENT.
(a) All existing and new municipal water systems and all other-than-municipal water systems constructed or modified after December 1, 2010, shall be provided with equipment and the necessary appurtenances which can continuously disinfect the water. The department may require the installation of disinfection equipment at existing other-than-municipal water systems where deemed necessary to ensure a safe water supply. Standby disinfection equipment shall be periodically checked and repaired, if necessary, to ensure it will work when it is required.
(b) All surface water treatment plants and other waterworks where treatment is required to produce a water quality meeting the primary maximum contaminant levels shall be equipped with backup chemical feed equipment for all chemicals required for treatment in the event of failure of the primary equipment.
(c) Written approval from the department is required prior to the addition of any chemical to a community water system. Non-community water systems shall refer to s. NR 812.37 for plan approval requirements for chemical feed systems. At public water systems that treat continuously, a 30-day supply of chemicals shall be kept on hand as required by s. NR 108.06(3). The 30-day supply shall be based on average day demand and average dose. Chemicals shall meet current A.W.W.A. standards and be approved by the department. Department approval may consist of, but is not limited to, certification of the chemical for use in potable water under NSF/ANSI Standard 60. Those chemical suppliers relabeling or repackaging NSF/ANSI 60 certified chemicals shall also be certified. Laboratories evaluating products for compliance with NSF/ANSI Standard 60 shall be certified by the American National Standards Institute. Colored chemicals shall be approved if coloring agents are not used in toxic concentrations or in amounts which impart taste, odor or color to the water supply. The department may require the analysis of chemicals if necessary to insure use of safe chemicals.

Note: Copies of these standards are available for inspection at the office of the Department of Natural Resources and the Legislative Reference Bureau.

Note: The Department of Safety and Professional Services requires plan submittal and approval of all treatment systems installed to service non-community water systems and designed to reduce health-related contaminants. For more information, see s. SPS 382.20.

(d) Chemical containers shall be labeled to include the chemical name, purity, concentration, and name and address of the chemical supplier.
(e) Requests for the substitution of disinfection agents in lieu of chlorine for bacteriological control shall be submitted to the department for review. Substitute disinfection agents may not be used without specific approval by the department.
(f) Solution tanks shall be maintained in a sanitary condition.
(g) The department may require an assay of chemicals delivered.
(h) A material safety data sheet (MSDS) shall be obtained by the water supplier from the chemical supplier for every chemical.
(2) DISINFECTION OF WATER FROM GROUNDWATER SOURCES.
(a) All municipal water systems shall provide continuous disinfection of the water prior to entry to the distribution system within 36 months of December 1, 2010. For systems that provide disinfection by chlorination, chloramination, or chlorine dioxide, a detectable residual shall be provided throughout the distribution system.

Note: It is recommended that all community water systems provide a detectable disinfectant residual throughout the distribution system.(b) When disinfection of water drawn from a groundwater source is required in order to meet the MCL for total coliform or E. coli contained in ch. NR 809 to maintain bacteriologically safe water, the residual maintained in the distribution system and the residual monitoring shall be as required in ss. NR 809.74(2) and NR 811.43(2). Additional disinfection requirements including disinfectant contact time or compliance with the disinfection requirements of s. NR 810.31(1) may be required by the department on a case-by-case basis. The following conditions, as well as other conditions, are considered by the department to be existing or potential water system public health threats:

1. A public water system history of microbiological contamination in the water source or distribution system by either coliform or noncoliform bacteria.
2. The presence of color in raw water from a well serving a public water system.
3. Inadequate construction, including construction which does not meet current requirements of ch. NR 811 or 812, of a well which serves a public water system.
(3) DISINFECTION OF WATER FROM SURFACE WATER AND GROUNDWATER UNDER THE DIRECT INFLUENCE OF SURFACE WATER SOURCES.
(a) For free chlorine, the concentration in the water entering the distribution system of any public water system, primary or consecutive, served by treated surface water shall be at least 0.2 mg/1 at the entry point to the distribution system and detectable throughout the distribution system. For total combined chlorine, the concentration in the water entering the distribution system of any public water system served by treated surface water shall be at least 1.0 mg/l at the entry point to the distribution system and detectable throughout the distribution system. Residual monitoring of the water entering the distribution system shall be provided as required in s. NR 809.74(2).
(b) Treatment plant CT values shall meet the applicable requirements found in ss. NR 810.47 to at all 810.62 times.
(4) CONSTRUCTION AND MODIFICATIONS.
(a) After construction, maintenance, repair or modification, waterworks facilities shall be disinfected by procedures outlined in the following A.W.W.A. Standards: A100 (August 1, 2006) for wells, C651 (June 1, 2005) for water mains, C652 (August 1, 2002) for water storage facilities, C653 (June 1, 2003) for water treatment plants or C654 (November 1, 2003) for wells. In addition, waterworks may not be placed in service until bacteriological samples have established that the water is safe for consumption in accordance with par. (b).

Note: Copies of these standards are available for inspection at the office of the Department of Natural Resources and the Legislative Reference Bureau, and may be obtained for personal use from the American Water Works Association, 6666 West Quincy Ave., Denver, Colorado, 80235.

(b) At least one bacteriologically safe sample shall be obtained before waterworks are placed into service. In the case of new or reconstructed wells, a minimum of 2 bacteriological safe samples, taken at least 8 hours apart during the test pumping period, or on 2 separate days, shall be obtained. When new distribution systems or extensions on a number of streets are installed, bacteriological samples shall be taken at representative locations to establish that all of the improvements are free of contamination. When water main breaks are repaired in public water systems that do not maintain a detectable chlorine residual, a bacteriological sample shall be taken in the area of the break within one working day. The main may be returned to service prior to receiving the results provided that the main has been disinfected and flushed. The water supplier shall comply with s. NR 809.31 when system sampling indicates the presence of coliform organisms. For water storage facilities, 2 or more successive safe samples, taken at 24-hour intervals, shall be obtained which indicate bacteriologically safe water or one safe sample shall be obtained only if a free chlorine residual of at least 0.1 mg/l is remaining when the results of the safe sample are reported.
(5) INDIRECT ADDITIVES. Written approval from the department is required prior to the use of any indirect chemical or material that may affect the quality of the water supply due to immersion or incidental contact in the water system. Department approval shall include certification of the chemical or material for use in potable water under NSF/ANSI Standard 61. Laboratories evaluating products for compliance with NSF/ANSI Standard 61 shall be certified by the American National Standards Institute. Written department approval is not required where existing equipment is being replaced with similar equipment during maintenance or repair provided that the water supplier can document that the equipment used meets the approval requirements of this section.

Wis. Admin. Code Department of Natural Resources NR 810.09

CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

Examples of indirect additives include process media, protective materials such as liners, paints and coatings, sealants, gaskets, fittings and lubricants.