NR 811.45(3m)(e)6.6. Include disinfection and adequate contact time after the water has passed through the tower, prior to the distribution system. NR 811.45(3m)(e)7.7. Include adequate packing support to allow free flow of water and prevent deformation with deep packing heights. NR 811.45(3m)(e)8.8. Include adequate foundation to support the tower and lateral support to prevent overturning to wind loading. NR 811.45(3m)(e)10.10. Provide access of all components of the tower, including the exhaust port and demister. NR 811.45(3m)(e)11.11. The operation of the blower and chemical feed pump shall be interlocked with the operation of the appropriate well or service pump. NR 811.45(4)(4) Other methods of aeration. Other methods of aeration may be approved by the department only if a pilot plant study conducted in accordance with s. NR 811.44 demonstrates the method’s effectiveness. Methods include spraying, diffused air, and mechanical aeration. The treatment processes shall be designed to meet the particular needs of the water to be treated. NR 811.45(5)(5) Disinfection. Aerated water other than from pressure aeration shall receive continuous disinfection treatment. A corporation stop shall be provided on the inlet piping to all non-pressure aerators to allow disinfection for emergency or maintenance purposes. NR 811.45(6)(6) Protection from wind. Aerators that discharge through the atmosphere shall be protected by being placed in a louvered enclosure designed to provide easy access to the interior. NR 811.45(7)(7) Protection from contamination. Aerators that are used for oxidation or removal of dissolved gases from waters that will be given no further treatment other than chlorination shall be protected from contamination from insects and birds, obnoxious fumes, all types of precipitation and condensation, and windborne debris or dust. NR 811.45(8)(8) Bypass piping. Bypass piping and any associated valves or other appurtenances shall be installed to allow water to be bypassed around a non-pressure aerator unless the aerator is necessary to comply with primary maximum contaminant levels or the requirement is waived by the department because the water system has access to other water sources that can provide at least an average day supply of water. NR 811.45(9)(9) Redundancy. Redundant aeration systems shall be provided for units installed to comply with primary maximum contaminant levels unless the requirement is waived by the department because the water system has access to other water sources that can provide at least an average day supply of water. NR 811.45(10)(10) Water quality. A metal smooth-end sampling faucet installed on the aerator outlet piping and test equipment shall be provided to test for appropriate water quality parameters following aeration such as dissolved oxygen, pH, iron, manganese, radon gas, and carbon dioxide when required by the department to insure proper operation of the aeration equipment. NR 811.45 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 22-074: am. (1) (e), r. and recr. (2) (k), cr. (3m) Register January 2024 No. 817, eff. 2-1-24. NR 811.46NR 811.46 Arsenic removal. The following minimum requirements shall be met when the following treatment methods are employed for arsenic removal: NR 811.46(1)(1) Pilot testing. All process designs shall be based on information from a pilot study unless waived by the department based upon previous demonstration that the process design will effectively remove arsenic based upon the water quality to be treated. Documentation shall be submitted to the department to support any pilot test waiver. NR 811.46(2)(2) Oxidation and filtration. Arsenic III shall be oxidized by chemical or physical processes or both to arsenic V and then filtered out. NR 811.46(2)(a)(a) Adequate detention time shall be provided if necessary to complete the conversion to arsenic V before filtration. NR 811.46(2)(b)(b) Ferric chloride or ferric sulfate shall be added to the water supply for water with less than a 20 to 1 ratio of iron to arsenic if necessary in order to provide adequate arsenic removal efficiency. NR 811.46(3)(3) Adsorptive media. Metal oxide coated adsorptive media may be used as the sole means of removing arsenic or in cooperation with or as a polishing unit after oxidation and filtration of arsenic. NR 811.46(3)(b)(b) The pilot study and final design shall address the following issues: NR 811.46(3)(b)1.1. Pre- and post-filtration adjustment of pH to enhance the arsenic removal rate and reduce water corrosivity. NR 811.46(3)(b)3.3. Oxidation and filtration of iron and manganese to prevent fouling of the media. NR 811.46(3)(b)4.4. Concentrations of sulfate and dissolved solids in the source water and the need to remove or reduce the concentrations in order to maintain treatment efficiency and minimize media fouling. NR 811.46(4)(4) Other acceptable treatment methods. Coagulation and filtration, anion exchange, electrodialysis, membrane filtration, and lime softening are treatment methods that may also be used to remove arsenic. The pilot study and final design shall address the following issues, if applicable: NR 811.46(4)(a)(a) Pre- and post-treatment adjustment of pH to enhance the arsenic removal rate, prevent scaling, or fouling of the treatment equipment, and reduce water corrosivity. NR 811.46(4)(b)(b) Conversion of the arsenic III to arsenic V prior to removal.