12 Va. Admin. Code § 5-590-790
Process water shall be taken from the finished water. An approved backflow prevention assembly or device shall be installed on the process water supply pipe before connection to the treatment process or equipment.
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Derived from VR355-18-007.16 § 3.16, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993.