NR 811.40(2)(h)(h) Acids shall be kept in closed, acid-resistant shipping containers, or storage units. Transfer from shipping containers to solution or day tanks shall be through acid resistant hose or pipe by means of a transfer pump.

NR 811.40(3)(3) Chemicals. All chemicals used to treat or produce potable water shall meet the following requirements:

NR 811.40(3)(a)(a) Shipping containers shall be fully labeled to include chemical name, purity, applicable NSF/ANSI standard approval in conformance with par. (b), concentration and supplier name and address.

NR 811.40 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; correction in (1) (p), (2) (c) 1., 3., (f) made under s. 13.92 (4) (b) 6., 7., Stats., Register December 2011 No. 672; CR 22-074: cr. (1) (cm), am. (1) (d), (g), (j), r. and recr. (1) (L), renum. (1) (n) to (1) (n) (intro.) and am., cr. (1) (n) 1., 2., Register January 2024 No. 817, eff. 2-1-24.

NR 811.41NR 811.41 General treatment design. The design of treatment processes and devices shall depend on evaluation of the nature and quality of the particular water to be treated and the desired quality of the finished water. Treatment shall be provided by each supplier of water if necessary in order to ensure that the finished water supplied to consumers meets the primary maximum contaminant levels contained in ch. NR 809 and is not objectionable to an appreciable number of consumers. The requirements of specific treatment processes are provided in ss. NR 811.42 to 811.60.

NR 811.42(1)(1) General requirements. All public water supply systems drawing water from lakes, rivers, streams, or other surface water sources shall, after the water is drawn, treat the water as provided in this chapter. In general and at a minimum, this treatment shall include coagulation, sedimentation, and filtration plus disinfection or membrane filtration plus disinfection. Filtration is required in all cases. Total plant removal and inactivation shall provide a minimum 99.9 percent (3-log) inactivation of Cryptosporidium and Giardia Lamblia plus 99.99 percent (4-log) inactivation of viruses.

NR 811.42(2)(2) Treatment requirements. The following treatment requirements shall be met:

NR 811.42(2)(a)(a) Conventional plants consisting of coagulation, sedimentation, and filtration that meet the turbidity requirements in s. NR 810.29 (1) are granted the following removal credits: 99.7 percent (2.5-log) Giardia Lamblia, 99.9 percent (3.0-log) Cryptosporidium and 99 percent (2-log) virus. The remaining 68 percent (0.5-log) Giardia Lamblia inactivation and 99 percent (2.0-log) virus inactivation shall be provided by CT disinfection. For conventional plants, a minimum of one-half of the required CT shall be provided after filtration.

NR 811.42(2)(d)(d) The department may approve any request for a deviation from required treatment methods based on data which shows that the requirements of this chapter are unnecessary in the specific case.

NR 811.42(3)(3) Redundancy. All critical treatment components shall be provided with redundancy.

NR 811.42(4)(4) CT values. CT values for the inactivation of Giardia Lamblia, Cryptosporidium, and viruses can be found in ss. NR 810.47 to 810.62.

NR 811.42(5)(5) Chlorine residual requirements. The free chlorine concentration in the water entering the distribution system shall be at least 0.2 mg/1 at the entry point to the distribution system and detectable throughout the distribution system or the total combined chlorine concentration shall be at least 1.0 mg/l at the entry point to the distribution system and detectable throughout the distribution system. Continuous chlorine residual monitoring of the water entering the distribution system shall be provided as required in ss. NR 809.74 (2) and 810.38 (2) (c).

NR 811.43(1)(1) Disinfection capability required. All municipal water systems constructed or modified after December 1, 2010, shall have equipment and the necessary appurtenances that can continuously disinfect the water. The department may require the installation of disinfection equipment at existing other-than-municipal water systems if necessary to ensure a safe water supply.

NR 811.43(2)(2) Disinfectant residual requirements. Disinfection of water drawn from groundwater sources is to supplement and not replace proper well location, construction, and source protection. When disinfection of water drawn from a groundwater source is required to maintain bacteriologically safe water, the residual maintained in the distribution system and the residual monitoring is the same as that required for surface water in s. NR 811.42 (5).

NR 811.43(3)(3) Disinfection requirements for wells. Specific disinfection requirements for wells are provided in subch. II. Any additional disinfection requirements for wells will be developed by the department if necessary on a case by case basis.

NR 811.43(4)(4) Disinfection of groundwater exposed to the atmosphere as part of a treatment process. Disinfection of water drawn from groundwater sources is required at facilities that expose the water to the atmosphere, such as open basins, open filters, air stripping towers, or gravity aerators.

NR 811.43(5)(5) Required actions for wells with non-complying water quality. One of the following actions shall be taken after consulting with the department if untreated water drawn from a groundwater source exceeds one or more of the primary maximum contaminant levels in ch. NR 809 or a department health advisory:

NR 811.43(5)(b)(b) The well shall be removed from service and either reconstructed or provided with permanent treatment to provide complying water quality. Wells may temporarily continue in service without reconstruction or providing permanent treatment only as approved by the department. Department approval is required prior to reconstructing the well or providing water treatment. Under emergency conditions, the department may allow temporary use of a well from which bacteriologically contaminated groundwater is drawn if disinfection adequate to ensure safe water is provided. In such cases, disinfection measures meeting the requirements of sub. (3) shall be provided. A continuous boil water notice may be required by the department during all or part of this interim period if deemed necessary by the department to protect public health.

NR 811.43(6)(6) Groundwater under the direct influence of surface water. The department may allow the use of water drawn from a groundwater source that has been determined by the department to be under the direct influence of surface water provided that treatment facilities meeting the requirements of subch. II of ch. NR 810 are provided as approved by the department. The total plant removal and inactivation shall provide a minimum 3-log inactivation of Cryptosporidium and Giardia Lamblia plus 4-log inactivation of viruses. The disinfectant residual maintained in the distribution system and residual monitoring shall be the same as required for treatment of water drawn from a surface water source in s. NR 811.42 (5). The department may approve modified treatment requirements for other-than-municipal public water systems if surface water treatment is impractical and if sufficient treatment can be provided. The supplier of water shall contact the department to determine what modified treatment will be approved.