R309-535-5. Fluoridation

  (1) This section does not require the addition of fluoride to drinking water by a public water system. However, a public water system that adds fluoride to drinking water shall comply with the fluoridation facility design and construction requirements of this section.

  (2) General Requirements for all Fluoridation Installations.

  The following requirements apply to all types of fluoridation.

  (a) Chemicals and Materials.

  (i) All chemicals used for fluoridation shall be certified to comply with ANSI/NSF Standard 60.

  (ii) Materials used for fluoridation equipment shall be compatible with chemicals used in the fluoridation process.

  (iii) Metal parts used in fluoridation equipment and present in the fluoridation room shall be corrosion resistant.

  (iv) Lead weights shall not be used in fluoride chemical solutions to keep pump suction lines at the bottom of a day or bulk storage tank.

  (b) Chemical Storage.

  (i) Fluoride chemicals shall be stored in covered or sealed containers, inside a building, and away from direct sunlight and a source of heat.

  (ii) Fluoride chemicals shall not be stored with incompatible chemicals.

  (iii) Bags or other containers for dry materials shall be stored on pallets.

  (iv) Containers for dry materials shall be kept closed to keep out moisture.

  (v) A solution tank shall be labeled to identify the contents of the tank.

  (c) Secondary Containment.

  (i) Secondary containment shall be provided for tanks containing corrosive fluoride solutions.

  (ii) Secondary containment shall be sized to contain the maximum volume of solution handled.

  (iii) Secondary containment shall be designed to be acid resistant.

  (d) Means to Measure.

  (i) A means to measure the flow of treated water shall be provided.

  (ii) A means shall be provided to measure the solution level in a tank and the quantity of the chemical used.

  (iii) A sampling point shall be provided downstream of the fluoridation facility for measuring the fluoride level of treated water.

  (e) Fluoride Feed Pump.

  (i) Sizing of fluoride feed pumps shall consider prevention of fluoride overfeed and operation efficiency.

  (ii) A fluoride feed pump shall have an anti-siphon device.

  (f) Electrical Outlet for Fluoride Feed Pump. The electrical outlet used for a fluoride feed pump shall have interlock protection by being wired with the well or service pump, such that the feed pump is only activated when the well or service pump is on. The fluoride feed pump shall not be plugged into a continuously active ("hot") electrical outlet.

  (g) Fluoride Injection.

  (i) The fluoride injection line shall enter at a point in the lower one-third of the water line, and the end of the injection line shall be in the lower half of the water line.

  (ii) The fluoride injection point shall allow adequate mixing.

  (iii) The fluoride injection point shall not be located upstream of lime softening, ion exchange, or other processes that affect the fluoride level.

  (iv) Each injector shall be selected based on the quantity of fluoride to be added, water flow, back pressure, and injector operating pressure.

  (v) If injecting fluoride under pressure, a corporation stop shall be used at the fluoride injection point.

  (vi) An anti-siphon device shall be provided for all fluoride feed lines at the injection point.

  (h) Minimize Fluoride Overfeed.

  (i) In addition to the feed pump control, a secondary control mechanism shall be provided to minimize the possibility of fluoride overfeed. It may be a day tank, liquid level sensor, SCADA control, flow switch, etc.

  (ii) For fluoridation facilities that do not have operators on site, a day tank is required to minimize fluoride overfeed, unless two alternative secondary controls are provided.

  (i) Housing. Fluoridation equipment shall be housed in a secure building that is adequately sized for handling and storing fluoride chemicals.

  (j) Heating, Lighting, Ventilation.

  (i) The fluoridation building shall be heated, lighted and ventilated to assure proper operation of the equipment and safety of the operator.

  (ii) The ventilation in the fluoride operating area shall provide at least six complete room-air changes per hour.

  (iii) The fluoride operating area shall be vented to outside atmosphere and away from air intakes.

  (iv) Separate switches for fans and lights in the fluoride operating area shall be provided. The switches shall be located outside or near the entrance to the fluoride operating area, and shall be protected from vandalism.

  (k) Cross Connection Control. Cross connection control shall be provided by an air gap or an approved and properly operating backflow prevention assembly.

  (3) Additional Requirements for Fluorosilicic Acid Installations.

  (a) Fluorosilicic acid shall not be diluted manually on site before injection.

  (b) Solution Tank Vents.

  (i) A bulk tank shall be vented.

  (ii) Tank venting shall be to the outside, above grade, away from air intakes, and where least susceptible to contamination (e.g., precipitation, dust, etc.).

  (iii) A bulk tank shall not share a vent with a day tank if there is a risk of solution overflow from the bulk tank to the day tank.

  (iv) A non-corrodible fine mesh (No. 14 or finer) screen shall be placed over the discharge end of a vent.

  (c) If separate rooms are provided in a fluoridation facility constructed after January 1, 2017, the design shall include a view window between the control room and the fluorosilicic acid operating area.

  (d) Emergency eyewash stations and showers shall be provided.

  (e) A neutralizing chemical shall be available on site to handle small quantity accidental acid spills.

  (f) The use of personal protective equipment (PPE) is required when handling fluorosilicic acid, and shall include the following:

  (i) Full-face shield and splash-proof safety goggles

  (ii) Long gauntlet acid-resistant rubber or neoprene gloves with cuffs

  (iii) Acid-resistant rubber or neoprene aprons

  (iv) Rubber boots

  (4) Additional Requirements for Fluoride Saturator Installations.

  (a) A water meter shall be provided on the make-up water line for a saturator to determine the amount of fluoride solution being fed.

  (b) The minimum depth of undissolved fluoride chemical required to maintain a saturated solution shall be marked on the outside of the saturator tank.

  (c) The saturator shall not be operated in a manner that undissolved chemical is drawn into the pump suction line.

  (d) The make-up water supply line shall terminate at least two pipe diameters above the solution tank or have backflow protection.

  (e) Make-up Water Softening.

  (i) The make-up water used for sodium fluoride saturators shall be softened whenever the hardness exceeds 75 mg/L.

  (ii) A sediment filter (20 mesh) shall be installed in the make-up water line going to the saturator. The filter shall be placed between the softener and the water meter.

  (f) Dust Control. Creation of fluoride dust shall be minimized during the transfer of dry fluoride compounds; when disposing of empty bags, drums, or barrels; and while cleaning.

  (g) Emergency eyewash shall be provided.

  (h) The use of personal protective equipment (PPE) is required when handling dry chemicals and shall include the following:

  (i) National Institute for Occupational Safety and Health (NIOSH) approved particulate respirator with a soft rubber face-to-mask seal and replaceable cartridges

  (ii) Chemical dust-resistant safety goggles

  (iii) Acid-resistant gloves

  (iv) Acid-resistant rubber or neoprene aprons

  (v) Rubber boots

  (5) Additional Requirements for Fluoride Dry Feed Installations.

  (a) Volumetric and gravimetric dry feeders shall include a solution tank.

  (b) A mechanical mixer shall be installed in the solution tank.

  (c) Dust Control.

  (i) Creation of fluoride dust shall be minimized during the transfer of dry fluoride compounds; when disposing of empty bags, drums, or barrels; and while cleaning.

  (ii) If a hopper is provided, it shall be equipped with a dust filter and an exhaust fan that places the hopper under negative pressure.

  (iii) Air exhausted from fluoride handling equipment shall discharge through a dust filter to the atmosphere outside of the building.

  (d) Emergency eyewash shall be provided.

  (e) The use of personal protective equipment (PPE) is required when handling dry chemicals and shall include the following:

  (i) National Institute for Occupational Safety and Health (NIOSH) approved particulate respirator with a soft rubber face-to-mask seal and replaceable cartridges

  (ii) Chemical dust-resistant safety goggles

  (iii) Acid-resistant gloves

  (iv) Acid-resistant rubber or neoprene aprons

  (v) Rubber boots