12VAC5-590-930. Fluoridation.
A. The board recommends that all community waterworks in Virginia be optimally fluoridated. Fluoridation feed systems shall be designed to deliver the optimum fluoride ion concentration as determined by the U.S. Department of Health and Human Services.
B. Fluoride compounds. Commercial sodium fluoride, sodium fluorosilicate (also called sodium silicofluoride), and fluorosilicic acid (also called hydrofluorosilicic acid) shall conform to the applicable AWWA standards or NSF/ANSI/CAN Standard 60-2020, as appropriate.
C. Fluoride compound storage. Fluoride chemicals shall be isolated from other chemicals to prevent cross contamination. Compounds shall be stored in covered or unopened shipping containers in a separate room (except sodium fluoride saturators) with the chemical feeder.
D. Chemical feed installations.
1. Scales and loss-of-weight recorders for dry chemical feeders and hydrofluorosilicic acid feeders shall be provided.
2. Fluoride metering pumps shall have an accuracy so that the actual feed rate will be within 5.0% of the intended feed rate.
3. The point of application shall be located to provide adequate mixing.
4. All fluoride feed lines shall be provided with adequate anti-siphon devices.
5. Design of fluoride saturators shall consider:
a. The source water hardness. The water applied to the sodium fluoride saturator feeders shall be softened if the hardness exceeds 50 mg/L.
b. The fluoride source. Use only sodium fluoride in the saturators.
c. A flow restrictor with a maximum flow of 2.0 gpm on all upflow saturators.
6. Adequate fluoride feed rate control and mixing shall be provided.
7. Provisions shall be made for venting fluorosilicic acid carboys to the outside of the building when the carboys are in use.
E. Suitable protective equipment shall be provided which includes gloves, aprons, dust mask, and goggles.
F. Suitable equipment shall be provided for wet mopping and hosing dust that might accumulate in the plant. Dry feeders shall be equipped with bag loading hoppers.
G. Equipment shall be provided for measuring the quantity of fluoride ion in the water. Testing equipment shall be colorimetric or electrode type as approved by the department.
Statutory Authority
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Historical Notes
Derived from VR355-18-009.09 § 3.30, eff. August 1, 1991; amended, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.