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.

NR 811.43(7)(7) Redundancy. All critical treatment components shall be provided with redundancy.

NR 811.43(8)(8) 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 811.43(9)(9) Treatment for nitrate. If the source water quality exceeds the nitrate maximum contaminant level set under s. NR 809.11 and treatment, blending, or other department-approved methods are provided to reduce the entry point nitrate concentration beneath the maximum contaminant level, a continuous nitrate analyzer shall be provided at the entry point. The continuous nitrate analyzer shall be programmed to include shut off controls or alarms if the nitrate concentration at the entry point exceeds the maximum contaminant level.

NR 811.44NR 811.44 Pilot testing. Pilot testing is required to establish effective treatment and operation requirements for new treatment methods, if revisions are proposed to existing treatment methods, if the water quality poses significant treatment issues, and if design parameters need to be determined for the first time or for the specific site conditions. The department may waive the pilot testing requirement if information on other locations where the proposed treatment methods using similar water quality are already in place and operating successfully is available or if other justification necessary to support the proposed treatment processes is submitted to the department. Pilot testing shall address the following requirements:

NR 811.44(1)(1) Plans, specifications, and an engineering report detailing the proposed pilot plant design, operation, sampling, lab analyses, and any waste disposal shall be submitted to the department and the written approval of the department shall be obtained prior to constructing or operating the pilot plant. At minimum, the pilot plant proposal shall address the following issues, where they apply:

NR 811.44(1)(b)(b) Length of pilot plant operation. The pilot plant shall operate long enough to establish the treatment effectiveness, media run lengths, wastewater volumes and characteristics, and any other necessary operating parameters. The pilot plant shall operate through a minimum of 2 treatment cycles or as determined by the department.