NR 811.50(19)(a)2. 2. Spare input/output (I/O) cards of each type.

NR 811.50(19)(a)3. 3. A minimum of 2 human machine interfaces (HMI).

NR 811.50(19)(a)4. 4. Backup power supply including uninterruptible power supply (UPS).

NR 811.50(19)(b) (b) Remote or unmanned operational control. Systems designed for remote or unmanned control shall be provided alarms, communication systems, and automatic shutdown processes. The department shall be contacted to determine the extent of operational control required. At a minimum the following alarms shall be provided:

NR 811.50(19)(b)1. 1. High raw or filtrate turbidity.

NR 811.50(19)(b)2. 2. Pump failure.

NR 811.50(19)(b)3. 3. High pressure decay test.

NR 811.50(19)(b)4. 4. High transmembrane pressure.

NR 811.50(19)(b)5. 5. PLC failure.

NR 811.50(19)(b)6. 6. Membrane unit shutdown.

NR 811.50(19)(b)7. 7. Clearwell level high or low.

NR 811.50(19)(b)8. 8. Equipment failure.

NR 811.50(19)(b)9. 9. High or low chlorine residual.

NR 811.50(19)(b)10. 10. Low chemical level.

NR 811.50(19)(b)11. 11. Power failure.

NR 811.50(19)(b)12. 12. Building intrusion

NR 811.50(19)(b)13. 13. Building low temperature.

NR 811.50 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 22-074: am. (3) Register January 2024 No. 817, eff. 2-1-24.

NR 811.51 NR 811.51 Fluoridation. Sodium fluoride, sodium fluorosilicate and fluorosilicic acid shall conform to the applicable NSF/ANSI Standard 60 and AWWA standards B701, B702, and B703 in effect at the time of use. Other fluoride compounds which may be available shall be approved by the department. The following specific requirements shall be met:

NR 811.51(1) (1) Fluoride chemical storage. Fluoride chemicals shall be stored in accordance with the following requirements:

NR 811.51(1)(a) (a) Fluoride chemicals shall be isolated from other chemicals to prevent contamination.

NR 811.51(1)(b) (b) Fluoride chemicals shall be stored in covered or unopened shipping containers and stored inside a building.

NR 811.51(1)(c) (c) Unsealed storage units for fluorosilicic acid shall be vented to the atmosphere at a point outside the building. The vent piping shall terminate a minimum of 24 inches above grade with a down-turned U-bend. The vent pipe opening shall be covered with a 24-mesh corrosion resistant screen.

NR 811.51(2) (2) Fluoride Acid housing. Equipment for feeding fluoride in the acid form and unsealed acid storage containers shall be housed in accordance with the following requirements:

NR 811.51(2)(a) (a) All chemical feed equipment, solution tanks, and acid containers shall be housed in a separate room within the pumphouse away from controls, electrical contacts, and other equipment subject to damage. Fluoride chemical feed installations shall be installed in a room separate from all other chemicals.

NR 811.51(2)(b) (b) Unsealed acid storage units or solution tanks shall be vented to the outside in accordance with sub. (1).

NR 811.51(2)(c) (c) Ventilation shall be provided for the room.

NR 811.51(2)(d) (d) Entrance may be from inside the pumphouse but shall include a gasketed, sealed door to minimize the transfer of fumes outside the fluoride room.

NR 811.51(3) (3) Chemical feed installations. Chemical feed installations shall: