13.10.030 Backflow prevention.
(1) Elimination. Cross connections shall be removed and eliminated where reasonably practical.
(2) Alternatives to Elimination. Where it is not reasonably practical to remove or eliminate a cross connection, then:
(a) An air gap separation, reduced pressure principle backflow prevention assembly (RPBA) or a reduced pressure principle detector prevention assembly (RPDA) shall be installed if the cross connection creates an actual or potential health hazard.
(b) An air gap separation, RPBA, RPDA, or double check detector backflow prevention assembly (DCDA) shall be installed if the cross connection is objectionable, but does not pose an unreasonable risk to health.
(c) A pressure vacuum breaker assembly (PVBA) or an atmospheric vacuum breaker (AVB) may be installed where the substance which could backflow is objectionable, but does not pose an unreasonable risk to health, and where there is no possibility of back pressure in the downstream piping.
(d) Backflow prevention assemblies, appropriate for the degree of hazard or air gaps and in some cases both, shall be installed at the service connection or within the department of health, no hazard exists: hospitals, mortuaries, clinics, laboratories, sewage treatment plants, food and beverage processing plants, chemical plants using process water, metal plating industries, petroleum processing or storage plants, radioactive material processing plants or nuclear reactors, car washes, facilities having a nonpotable auxiliary water supply, and others specified by the department.
(3) Backflow Prevention Assemblies/Devices. All installed RPBAs, RPDAs, DCVAs, DCDAs and PVBAs shall be models included on the current list of Washington State-approved cross connection control assembly devices at the time of installation. All installed RPBAs, RPDAs, DCVAs, DCDAs and PVDAs in service, but not listed on the current state-approved cross connection control assembly list, may remain in service provided the backflow prevention assemblies:
(a) Were listed on the current Washington State-approved cross connection control assembly list at the time of installation;
(b) Are properly maintained;
(c) Are of a type appropriate for the degree of hazard; and
(d) Are tested and successfully pass the test annually.
When unlisted assemblies are moved or require more than minimum maintenance, the unlisted assemblies shall be replaced by an assembly listed on the current approved model list.
(4) Installation of Backflow Prevention Assemblies/Devices. All air gaps and backflow prevention assemblies shall be installed in accordance with the cross connection control manual of the Pacific Northwest Section – American Water Works Association adopted by WAC 246-290-490.
(5) Substitution. The city of Electric City may permit the substitution of a properly installed air gap in lieu of an approved backflow prevention assembly. All such air gap substitutions shall be inspected annually by a Washington State certified backflow assembly tester.
(6) Inspection and Testing.
(a) A Washington State certified backflow assembly tester shall inspect and test all:
(i) RPBAs;
(ii) RPDAs;
(iii) DCVAs;
(iv) DCDAs;
(v) New PVDA installations; and
(vi) Existing PVBAs discovered through routine inspections.
(b) Tests and/or inspections shall be conducted as follows:
(i) At the time of initial installation;
(ii) Annually after initial installation, or more frequently if tests indicate repeated failures; and
(iii) After the assembly is repaired.
(7) Repair/Replacement. The assemblies shall be repaired, overhauled, or replaced whenever found to be defective. Improperly installed or altered air gaps must be replumbed or replaced by an approved RPBA at their discretion. Inspections, tests, and repairs shall be made under the city of Electric City’s supervision and records thereof kept as required by the city of Electric City. (Ord. 456 § 1, 2012; Ord. 335 § 4, 1998)