12 Va. Admin. Code § 5-590-630
A. Any backflow prevention assembly or backflow elimination method or backflow prevention device shall be of the approved type and shall comply with the USBC.
B. General safeguards
2. The degree of hazard, either high or low, is based on (i) the nature of the contaminant; (ii) the potential of the health hazard; (iii) the potential method of backflow (either by backpressure or by backsiphonage); and (iv) the potential effect on waterworks structures, equipment, and appurtenances used in the storage, collection, purification, treatment, and distribution of potable water. Table 630.1 shall be used as a guide to determine the degree of hazard for any situation.
| Table 630.1 Determination of Degree of Hazard | |
| Cross-connections that meet or may meet the following conditions shall be rated at the corresponding degree of hazard. | |
| High Hazard | Low Hazard |
| The contaminant would be toxic, poisonous, noxious, unhealthy, or of unknown quality. | The contaminant would only degrade the quality of the water aesthetically or impair the usefulness of the water. |
| A health hazard would exist. | A health hazard would not exist. |
| The contaminant would disrupt the service of piped water for human consumption. | The contaminant would not disrupt service of piped water for human consumption. |
| Backflow would be by either backpressure or backsiphonage. | Backflow would occur by backsiphonage. |
| Examples: lawn irrigation systems, fire sprinkler systems with chemical additives or antifreeze, sewage, used water, nonpotable water, auxiliary water systems, and mixtures of water and other liquids, gases, or other chemicals. | Examples: food residuals, coffee machines, non-carbonated beverage dispensers, and residential fire sprinkler systems constructed of materials designed for potable water flow. |
C. Owners shall not allow the installation of backflow prevention devices or backflow prevention assemblies with openings, outlets, or vents that are designed to operate or open during backflow prevention:
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Derived from VR355-18-006.06 § 2.30, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 31, Issue 1, eff. October 10, 2014; Volume 37, Issue 20, eff. June 23, 2021.