§ 25-135. Backflow prevention devices and backflow prevention by separation for containment.

A.

Backflow prevention devices for containment include the reduced pressure principle backflow prevention assembly, the double gate-double check valve assembly, and the pressure vacuum breaker assembly.

B.

Backflow prevention by separation shall be an air gap or physical disconnection. The minimum air gap shall be twice the effective opening of a potable water outlet unless the outlet is a distance less than three (3) times the effective opening away from a wall or similar vertical surface, in which case the minimum air gap shall be three times the effective opening of the outlet. In no case shall the minimum air gap be less than one (1) inch.

C.

Backflow prevention devices shall be of the approved type and shall comply with the most recent American Water Works Association Standards and shall be approved for containment by the University of Southern California Foundation for Cross-Connection Control and Hydraulic Research.

D.

Backflow prevention devices shall be installed in a manner approved by the director of public works or designee and in accordance with the University of Southern California Foundation for Cross-Connection Control and Hydraulic Research recommendations and the manufacturer's installation instructions. Vertical or horizontal positioning shall be as approved by the University of Southern California Foundation for Cross-Connection Control and Hydraulic Research.

E.

Existing backflow prevention devices approved by the director of public works or designee prior to the effective date of this article [Nov. 11, 2004] shall, except for inspection, testing, and maintenance requirements, be excluded from the requirements of sections X. C. and D. if the director of public works or designee is assured that the devices will protect the waterworks.

F.

For the purpose of application to special conditions, section VII.B.2., point-of-use isolation devices or separations shall be as specified by the director of public works or designee where reasonable assurance can be shown that the device or separation will protect the waterworks. As a minimum, point-of-use devices should bear an appropriate American Society of Sanitary Engineering standard number. See the cross connection control program, appendix A, for isolation device application.

G.

Backflow prevention devices with openings, outlets, or vents that are designed to operate or open during backflow prevention shall not be installed in pits or areas subject to flooding.

(Ord. No. 04-1700-769, § 1, 11-11-04)

(Ord. No. 04-1700-769, § 1, 11-11-04)